Increased hypothalamic 5-HT2A receptor gene expression and effects of pharmacologic 5-HT2A receptor inactivation in obese A{sup y} mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nonogaki, Katsunori; Nozue, Kana; Oka, Yoshitomo

2006-12-29

Serotonin (5-hydroxytryptamine; 5-HT) 2A receptors contribute to the effects of 5-HT on platelet aggregation and vascular smooth muscle cell proliferation, and are reportedly involved in decreases in plasma levels of adiponectin, an adipokine, in diabetic subjects. Here, we report that systemic administration of sarpogrelate, a 5-HT2A receptor antagonist, suppressed appetite and increased hypothalamic pro-opiomelanocortin and cocaine- and amphetamine-regulated transcript, corticotropin releasing hormone, 5-HT2C, and 5-HT1B receptor gene expression. A{sup y} mice, which have ectopic expression of the agouti protein, significantly increased hypothalamic 5-HT2A receptor gene expression in association with obesity compared with wild-type mice matched for age. Systemic administration ofmore » sarpogrelate suppressed overfeeding, body weight gain, and hyperglycemia in obese A{sup y} mice, whereas it did not increase plasma adiponectin levels. These results suggest that obesity increases hypothalamic 5-HT2A receptor gene expression, and pharmacologic inactivation of 5-HT2A receptors inhibits overfeeding and obesity in A{sup y} mice, but did not increase plasma adiponectin levels.« less

Functional expression of purinergic P2 receptors and transient receptor potential channels by the human urothelium.

PubMed

Shabir, Saqib; Cross, William; Kirkwood, Lisa A; Pearson, Joanna F; Appleby, Peter A; Walker, Dawn; Eardley, Ian; Southgate, Jennifer

2013-08-01

In addition to its role as a physical barrier, the urothelium is considered to play an active role in mechanosensation. A key mechanism is the release of transient mediators that activate purinergic P2 receptors and transient receptor potential (TRP) channels to effect changes in intracellular Ca²⁺. Despite the implied importance of these receptors and channels in urothelial tissue homeostasis and dysfunctional bladder disease, little is known about their functional expression by the human urothelium. To evaluate the expression and function of P2X and P2Y receptors and TRP channels, the human ureter and bladder were used to separate urothelial and stromal tissues for RNA isolation and cell culture. RT-PCR using stringently designed primer sets was used to establish which P2 and TRP species were expressed at the transcript level, and selective agonists/antagonists were used to confirm functional expression by monitoring changes in intracellular Ca²⁺ and in a scratch repair assay. The results confirmed the functional expression of P2Y₄ receptors and excluded nonexpressed receptors/channels (P2X₁, P2X₃, P2X₆, P2Y₆, P2Y₁₁, TRPV5, and TRPM8), while a dearth of specific agonists confounded the functional validation of expressed P2X₂, P2X₄, P2Y₁, P2Y₂, TRPV2, TRPV3, TRPV6 and TRPM7 receptors/channels. Although a conventional response was elicited in control stromal-derived cells, the urothelial cell response to well-characterized TRPV1 and TRPV4 agonists/antagonists revealed unexpected anomalies. In addition, agonists that invoked an increase in intracellular Ca²⁺ promoted urothelial scratch repair, presumably through the release of ATP. The study raises important questions about the ligand selectivity of receptor/channel targets expressed by the urothelium. These pathways are important in urothelial tissue homeostasis, and this opens the possibility of selective drug targeting.

Distribution of cellular HSV-1 receptor expression in human brain.

PubMed

Lathe, Richard; Haas, Juergen G

2017-06-01

Herpes simplex virus type 1 (HSV-1) is a neurotropic virus linked to a range of acute and chronic neurological disorders affecting distinct regions of the brain. Unusually, HSV-1 entry into cells requires the interaction of viral proteins glycoprotein D (gD) and glycoprotein B (gB) with distinct cellular receptor proteins. Several different gD and gB receptors have been identified, including TNFRSF14/HVEM and PVRL1/nectin 1 as gD receptors and PILRA, MAG, and MYH9 as gB receptors. We investigated the expression of these receptor molecules in different areas of the adult and developing human brain using online transcriptome databases. Whereas all HSV-1 receptors showed distinct expression patterns in different brain areas, the Allan Brain Atlas (ABA) reported increased expression of both gD and gB receptors in the hippocampus. Specifically, for PVRL1, TNFRFS14, and MYH9, the differential z scores for hippocampal expression, a measure of relative levels of increased expression, rose to 2.9, 2.9, and 2.5, respectively, comparable to the z score for the archetypical hippocampus-enriched mineralocorticoid receptor (NR3C2, z = 3.1). These data were confirmed at the Human Brain Transcriptome (HBT) database, but HBT data indicate that MAG expression is also enriched in hippocampus. The HBT database allowed the developmental pattern of expression to be investigated; we report that all HSV1 receptors markedly increase in expression levels between gestation and the postnatal/adult periods. These results suggest that differential receptor expression levels of several HSV-1 gD and gB receptors in the adult hippocampus are likely to underlie the susceptibility of this brain region to HSV-1 infection.

Hypothyroidism Affects D2 Receptor-mediated Breathing without altering D2 Receptor Expression

PubMed Central

Schlenker, Evelyn H.; Rio, Rodrigo Del; Schultz, Harold D.

2015-01-01

Bromocriptine depressed ventilation in air and D2 receptor expression in the nucleus tractus solitaries (NTS) in male hypothyroid hamsters. Here we postulated that in age- matched hypothyroid female hamsters, the pattern of D2 receptor modulation of breathing and D2 receptor expression would differ from those reported in hypothyroid males. In females hypothyroidism did not affect D2 receptor protein levels in the NTS, carotid bodies or striatum. Bromocriptine, but not carmoxirole (a peripheral D2 receptor agonist), increased oxygen consumption and body temperature in awake air-exposed hypothyroid female hamsters and stimulated their ventilation before and following exposure to hypoxia. Carmoxirole depressed frequency of breathing in euthyroid hamsters prior to, during and following hypoxia exposures and stimulated it in the hypothyroid hamsters following hypoxia. Although hypothyroidism did not affect expression of D2 receptors, it influenced central D2 modulation of breathing in a disparate manner relative to euthyroid hamsters. PMID:24434437

Hypothyroidism affects D2 receptor-mediated breathing without altering D2 receptor expression.

PubMed

Schlenker, Evelyn H; Del Rio, Rodrigo; Schultz, Harold D

2014-03-01

Bromocriptine depressed ventilation in air and D2 receptor expression in the nucleus tractus solitaries (NTS) in male hypothyroid hamsters. Here we postulated that in age-matched hypothyroid female hamsters, the pattern of D2 receptor modulation of breathing and D2 receptor expression would differ from those reported in hypothyroid males. In females hypothyroidism did not affect D2 receptor protein levels in the NTS, carotid bodies or striatum. Bromocriptine, but not carmoxirole (a peripheral D2 receptor agonist), increased oxygen consumption and body temperature in awake air-exposed hypothyroid female hamsters and stimulated their ventilation before and following exposure to hypoxia. Carmoxirole depressed frequency of breathing in euthyroid hamsters prior to, during and following hypoxia exposures and stimulated it in the hypothyroid hamsters following hypoxia. Although hypothyroidism did not affect expression of D2 receptors, it influenced central D2 modulation of breathing in a disparate manner relative to euthyroid hamsters. Copyright © 2014 Elsevier B.V. All rights reserved.

Cellular density-dependent down-regulation of EP4 prostanoid receptors via the up-regulation of hypoxia-inducible factor-1α in HCA-7 human colon cancer cells.

PubMed

Otake, Sho; Yoshida, Kenji; Seira, Naofumi; Sanchez, Christopher M; Regan, John W; Fujino, Hiromichi; Murayama, Toshihiko

2015-02-01

Increases in prostaglandin E2 (PGE2) and cyclooxygenase-2 (COX-2) levels are features of colon cancer. Among the different E-type prostanoid receptor subtypes, EP4 receptors are considered to play a crucial role in carcinogenesis by, for example, inducing COX-2 when stimulated with PGE2. However, EP4 receptor levels and PGE2-induced cellular responses are inconsistent among the cellular conditions. Therefore, the connections responsible for the expression of EP4 receptors were investigated in the present study by focusing on cell density-induced hypoxia-inducible factor-1α (HIF-1α). The expression of EP4 receptors was examined using immunoblot analysis, quantitative polymerase chain reaction, and reporter gene assays in HCA-7 human colon cancer cells with different cellular densities. The involvement of HIF-1α and its signaling pathways were also examined by immunoblot analysis, reporter gene assays, and with siRNA. We here demonstrated that EP4 receptors as well as EP4 receptor-mediated COX-2 expression levels decreased with an increase in cellular density. In contrast, HIF-1α levels increased in a cellular density-dependent manner. The knockdown of HIF-1α by siRNA restored the expression of EP4 receptors and EP4 receptor-mediated COX-2 in cells at a high density. Thus, the cellular density-dependent increase observed in HIF-1α expression levels reduced the expression of COX-2 by decreasing EP4 receptor levels. This novel regulation mechanism for the expression of EP4 receptors by HIF-1α may provide an explanation for the inconsistent actions of PGE2. The expression levels of EP4 receptors may vary depending on cellular density, which may lead to the differential activation of their signaling pathways by PGE2. Thus, cellular density-dependent PGE2-mediated signaling may determine the fate/stage of cancer cells, i.e., the surrounding environments could define the fate/stage of malignancies associated with colon cancer.

Cellular density-dependent down-regulation of EP4 prostanoid receptors via the up-regulation of hypoxia-inducible factor-1α in HCA-7 human colon cancer cells

PubMed Central

Otake, Sho; Yoshida, Kenji; Seira, Naofumi; Sanchez, Christopher M; Regan, John W; Fujino, Hiromichi; Murayama, Toshihiko

2015-01-01

Increases in prostaglandin E2 (PGE2) and cyclooxygenase-2 (COX-2) levels are features of colon cancer. Among the different E-type prostanoid receptor subtypes, EP4 receptors are considered to play a crucial role in carcinogenesis by, for example, inducing COX-2 when stimulated with PGE2. However, EP4 receptor levels and PGE2-induced cellular responses are inconsistent among the cellular conditions. Therefore, the connections responsible for the expression of EP4 receptors were investigated in the present study by focusing on cell density-induced hypoxia-inducible factor-1α (HIF-1α). The expression of EP4 receptors was examined using immunoblot analysis, quantitative polymerase chain reaction, and reporter gene assays in HCA-7 human colon cancer cells with different cellular densities. The involvement of HIF-1α and its signaling pathways were also examined by immunoblot analysis, reporter gene assays, and with siRNA. We here demonstrated that EP4 receptors as well as EP4 receptor-mediated COX-2 expression levels decreased with an increase in cellular density. In contrast, HIF-1α levels increased in a cellular density-dependent manner. The knockdown of HIF-1α by siRNA restored the expression of EP4 receptors and EP4 receptor-mediated COX-2 in cells at a high density. Thus, the cellular density-dependent increase observed in HIF-1α expression levels reduced the expression of COX-2 by decreasing EP4 receptor levels. This novel regulation mechanism for the expression of EP4 receptors by HIF-1α may provide an explanation for the inconsistent actions of PGE2. The expression levels of EP4 receptors may vary depending on cellular density, which may lead to the differential activation of their signaling pathways by PGE2. Thus, cellular density-dependent PGE2-mediated signaling may determine the fate/stage of cancer cells, i.e., the surrounding environments could define the fate/stage of malignancies associated with colon cancer. PMID:25692008

Clathrin-dependent internalization of the angiotensin II AT₁A receptor links receptor internalization to COX-2 protein expression in rat aortic vascular smooth muscle cells.

PubMed

Morinelli, Thomas A; Walker, Linda P; Velez, Juan Carlos Q; Ullian, Michael E

2015-02-05

The major effects of Angiotensin II (AngII) in vascular tissue are mediated by AngII AT1A receptor activation. Certain effects initiated by AT1A receptor activation require receptor internalization. In rat aortic vascular smooth muscle cells (RASMC), AngII stimulates cyclooxygenase 2 protein expression. We have previously shown this is mediated by β-arrestin-dependent receptor internalization and NF-κB activation. In this study, a specific inhibitor of clathrin-mediated endocytosis (CME), pitstop-2, was used to test the hypothesis that clathrin-dependent internalization of activated AT1A receptor mediates NF-κB activation and subsequent cyclooxygenase 2 expression. Radioligand binding assays, real time qt-PCR and immunoblotting were used to document the effects of pitstop-2 on AngII binding and signaling in RASMC. Laser scanning confocal microscopy (LSCM) was used to image pitstop-2׳s effects on AT1 receptor/GFP internalization in HEK-293 cells and p65 NF-κB nuclear localization in RASMC. Pitstop-2 significantly inhibited internalization of AT1A receptor (44.7% ± 3.1% Control vs. 13.2% ± 8.3% Pitstop-2; n=3) as determined by radioligand binding studies in RASMC. Studies utilizing AT1A receptor/GFP expressed in HEK 293 cells and LSCM confirmed these findings. Pitstop-2 significantly inhibited AngII-induced p65 NF-κB phosphorylation and nuclear localization, COX-2 message and protein expression in RASMC without altering activation of p42/44 ERK or TNFα signaling. Pitstop-2, a specific inhibitor of clathrin-mediated endocytosis, confirms that internalization of activated AT1A receptor mediates AngII activation of cyclooxygenase 2 expression in RASMC. These data provide support for additional intracellular signaling pathways activated through β-arrestin mediated internalization of G protein-coupled receptors, such as AT1A receptors. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of YM471, a nonpeptide AVP V1A and V2 receptor antagonist, on human AVP receptor subtypes expressed in CHO cells and oxytocin receptors in human uterine smooth muscle cells

PubMed Central

Tsukada, Junko; Tahara, Atsuo; Tomura, Yuichi; Wada, Koh-ichi; Kusayama, Toshiyuki; Ishii, Noe; Yatsu, Takeyuki; Uchida, Wataru; Taniguchi, Nobuaki; Tanaka, Akihiro

2001-01-01

YM471, (Z)-4′-{4,4-difluoro-5-[2-(4-dimethylaminopiperidino)-2-oxoethylidene]-2,3,4,5-tetrahydro-1H-1-benzoazepine-1-carbonyl}-2-phenylbenzanilide monohydrochloride, is a newly synthesized potent vasopressin (AVP) receptor antagonist. Its effects on binding to and signal transduction by cloned human AVP receptors (V1A, V1B and V2) stably expressed in Chinese hamster ovary (CHO) cells, and oxytocin receptors in human uterine smooth muscle cells (USMC) were studied. YM471 potently inhibited specific [3H]-AVP binding to V1A and V2 receptors with Ki values of 0.62 nM and 1.19 nM, respectively. In contrast, YM471 exhibited much lower affinity for V1B and oxytocin receptors with Ki values of 16.4 μM and 31.6 nM, respectively. In CHO cells expressing V1A receptors, YM471 potently inhibited AVP-induced intracellular Ca2+ concentration ([Ca2+]i) increase, exhibiting an IC50 value of 0.56 nM. However, in human USMC expressing oxytocin receptors, YM471 exhibited much lower potency in inhibiting oxytocin-induced [Ca2+]i increase (IC50=193 nM), and did not affect AVP-induced [Ca2+]i increase in CHO cells expressing V1B receptors. Furthermore, in CHO cells expressing V2 receptors, YM471 potently inhibited the production of cyclic AMP stimulated by AVP with an IC50 value of 1.88 nM. In all assays, YM471 showed no agonistic activity. These results demonstrate that YM471 is a potent, nonpeptide human V1A and V2 receptor antagonist which will be a valuable tool in defining the physiologic and pharmacologic actions of AVP. PMID:11429400

Effects of YM471, a nonpeptide AVP V(1A) and V(2) receptor antagonist, on human AVP receptor subtypes expressed in CHO cells and oxytocin receptors in human uterine smooth muscle cells.

PubMed

Tsukada, J; Tahara, A; Tomura, Y; Wada Ki; Kusayama, T; Ishii, N; Yatsu, T; Uchida, W; Taniguchi, N; Tanaka, A

2001-07-01

YM471, (Z)-4'-[4,4-difluoro-5-[2-(4-dimethylaminopiperidino)-2-oxoethylidene]-2,3,4,5-tetrahydro-1H-1-benzoazepine-1-carbonyl]-2-phenylbenzanilide monohydrochloride, is a newly synthesized potent vasopressin (AVP) receptor antagonist. Its effects on binding to and signal transduction by cloned human AVP receptors (V(1A), V(1B) and V(2)) stably expressed in Chinese hamster ovary (CHO) cells, and oxytocin receptors in human uterine smooth muscle cells (USMC) were studied. YM471 potently inhibited specific [(3)H]-AVP binding to V(1A) and V(2) receptors with K(i) values of 0.62 nM and 1.19 nM, respectively. In contrast, YM471 exhibited much lower affinity for V(1B) and oxytocin receptors with K(i) values of 16.4 microM and 31.6 nM, respectively. In CHO cells expressing V(1A) receptors, YM471 potently inhibited AVP-induced intracellular Ca(2+) concentration ([Ca(2+)](i)) increase, exhibiting an IC(50) value of 0.56 nM. However, in human USMC expressing oxytocin receptors, YM471 exhibited much lower potency in inhibiting oxytocin-induced [Ca(2+)](i) increase (IC(50)=193 nM), and did not affect AVP-induced [Ca(2+)](i) increase in CHO cells expressing V(1B) receptors. Furthermore, in CHO cells expressing V(2) receptors, YM471 potently inhibited the production of cyclic AMP stimulated by AVP with an IC(50) value of 1.88 nM. In all assays, YM471 showed no agonistic activity. These results demonstrate that YM471 is a potent, nonpeptide human V(1A) and V(2) receptor antagonist which will be a valuable tool in defining the physiologic and pharmacologic actions of AVP.

Pharmacological similarities between native brain and heterologously expressed α4β2 nicotinic receptors

PubMed Central

Shafaee, Navid; Houng, McCann; Truong, Anthony; Viseshakul, Nareerat; Figl, Antonio; Sandhu, Sumandeep; Forsayeth, John R; Dwoskin, Linda P; Crooks, Peter A; Cohen, Bruce N

1999-01-01

We studied the pharmacological properties of native rat brain and heterologously expressed rat α4β2 nicotinic receptors immunoprecipitated onto a fixed substrate with the anti-α4 antibody mAb 299.Immunodepletion with the anti-β2 antibody mAb 270 showed that 89% of the mAb-299-precipitated rat brain receptors contained β2.The association and dissociation rate constants for 30 pM ±[3H]-epibatidine binding to α4β2 receptors expressed in oocytes were 0.02±0.01 and 0.03±0.01 min−1 (±standard error, degrees of freedom=7–8) at 20–23°C.The Hill coefficients for ±[3H]epibatidine binding to the native brain, α4β2 receptors expressed in oocytes, and α4β2 receptors expressed in CV-1 cells (using recombinant adenovirus) were 0.69–0.70 suggesting a heterogeneous receptor population. Fits of the ±[3H]-epibatidine concentration-binding data to a two-site model gave KD s of 8–30 and 560–1,200 pM. The high-affinity sites comprised 73–74% of the native brain and oocyte α4β2 receptor population, 85% of the CV-1 α4β2 receptor population.The expression of rat α4β2 receptors in CV-1 cells using vaccinia viral infection-transfection resulted in a more homogeneous receptor population (Hill coefficient of 1.0±0.2). Fits of the ±[3H]-epibatidine binding data to a single-site model gave a KD of 40±3 pM.DHβE (IC50=260–470 nM) and the novel nicotine analogue NDNI (IC50=7–10 μM) inhibited 30 pM±[3H]-epibatidine binding to the native brain and heterologously expressed α4β2 receptors equally well.The results show that α4β2-containing nicotinic receptors in the rat brain and heterologously expressed rat α4β2 receptors have similar affinities for ±[3H]-epibatidine, DHβE, and NDNI. PMID:10578144

Extrinsic factors regulate partial agonist efficacy of strychnine-sensitive glycine receptors

PubMed Central

Farroni, Jeffrey S; McCool, Brian A

2004-01-01

Background Strychnine-sensitive glycine receptors in many adult forebrain regions consist of alpha2 + beta heteromeric channels. This subunit composition is distinct from the alpha1 + beta channels found throughout the adult spinal cord. Unfortunately, the pharmacology of forebrain alpha2beta receptors are poorly defined compared to 'neonatal' alpha2 homomeric channels or 'spinal' alpha1beta heteromers. In addition, the pharmacologic properties of native alpha2beta glycine receptors have been generally distinct from receptors produced by heterologous expression. To identify subtype-specific pharmacologic tools for the forebrain alpha2beta receptors, it is important to identify a heterologous expression system that closely resembles these native glycine-gated chloride channels. Results While exploring pharmacological properties of alpha2beta glycine receptors compared to alpha2-homomers, we found that distinct heterologous expression systems appeared to differentially influence partial agonist pharmacology. The β-amino acid taurine possessed 30–50% efficacy for alpha2-containing receptor isoforms when expressed in HEK 293 cells. However, taurine efficacy was dramatically reduced in L-cell fibroblasts. Similar results were obtained for β-alanine. The efficacy of these partial agonists was also strongly reduced by the beta subunit. There were no significant differences in apparent strychnine affinity values calculated from concentration-response data between expression systems or subunit combinations. Nor did relative levels of expression correlate with partial agonist efficacy when compared within or between several different expression systems. Finally, disruption of the tubulin cytoskeleton reduced the efficacy of partial agonists in a subunit-dependent, but system-independent, fashion. Conclusions Our results suggest that different heterologous expression systems can dramatically influence the agonist pharmacology of strychnine-sensitive glycine receptors. In the systems examine here, these effects are independent of both absolute expression level and any system-related alterations in the agonist binding site. We conclude that complex interactions between receptor composition and extrinsic factors may play a significant role in determining strychnine-sensitive glycine receptor partial agonist pharmacology. PMID:15301692

Extrinsic factors regulate partial agonist efficacy of strychnine-sensitive glycine receptors.

PubMed

Farroni, Jeffrey S; McCool, Brian A

2004-08-09

Strychnine-sensitive glycine receptors in many adult forebrain regions consist of alpha2 + beta heteromeric channels. This subunit composition is distinct from the alpha1 + beta channels found throughout the adult spinal cord. Unfortunately, the pharmacology of forebrain alpha2beta receptors are poorly defined compared to 'neonatal' alpha2 homomeric channels or 'spinal' alpha1beta heteromers. In addition, the pharmacologic properties of native alpha2beta glycine receptors have been generally distinct from receptors produced by heterologous expression. To identify subtype-specific pharmacologic tools for the forebrain alpha2beta receptors, it is important to identify a heterologous expression system that closely resembles these native glycine-gated chloride channels. While exploring pharmacological properties of alpha2beta glycine receptors compared to alpha2-homomers, we found that distinct heterologous expression systems appeared to differentially influence partial agonist pharmacology. The beta-amino acid taurine possessed 30-50% efficacy for alpha2-containing receptor isoforms when expressed in HEK 293 cells. However, taurine efficacy was dramatically reduced in L-cell fibroblasts. Similar results were obtained for beta-alanine. The efficacy of these partial agonists was also strongly reduced by the beta subunit. There were no significant differences in apparent strychnine affinity values calculated from concentration-response data between expression systems or subunit combinations. Nor did relative levels of expression correlate with partial agonist efficacy when compared within or between several different expression systems. Finally, disruption of the tubulin cytoskeleton reduced the efficacy of partial agonists in a subunit-dependent, but system-independent, fashion. Our results suggest that different heterologous expression systems can dramatically influence the agonist pharmacology of strychnine-sensitive glycine receptors. In the systems examine here, these effects are independent of both absolute expression level and any system-related alterations in the agonist binding site. We conclude that complex interactions between receptor composition and extrinsic factors may play a significant role in determining strychnine-sensitive glycine receptor partial agonist pharmacology.

Cloning and functional characterization of the DA2 receptor gene in Chinese mitten crab (Eriocheir sinensis)

PubMed Central

Xu, Min-jie; Zhang, Cong; Yang, Zhigang

2018-01-01

Dopamine (DA) plays a modulatory role in numerous physiological processes such as light adaptation and food intake, and exerts these functions through DA receptors (DARs). This study presents, for the first time, isolation and characterization of the dopamine receptor 2(DA2 receptor) cDNA from the intestinal tissue of Eriocheir sinensis, an economically important freshwater aquaculture species in China. The DA2 receptor cDNA sequence, which was obtained by rapid amplification of cDNA ends, is 2369bp long, encode peptide of 589 amino acid, and is highly homologous to related sequences in crustaceans. Analysis of the deduced amino acid sequence and the structure of the DA2 indicated that this receptor is a member of the family of G protein-coupled receptors (GPCRs), as it contains seven transmembrane domains and other common signatures of GPCRs. RT-PCR showed that the expression of the DA2 receptor gene was distributed in various tissues, and high expression levels were observed in the cranial ganglia and the thoracic ganglia. Further study of the effect of photoperiod on DA2 expression showed that constant darkness induced a significant increase in DA2 expression in the cranial ganglia. Finally, analysis of DA2 receptor expression under different feeding statuses showed that there was significantly greater expression in the hepatopancreas and intestines after feeding than before feeding, but there were no differences in expression between the before feeding and during feeding periods in either tissue. Our results indicate that the DA2 receptor structurally belongs to the family of G protein-coupled receptors, and that the cranial ganglia are the main tissues in which the DA2 receptor participates in light adaptation during dark hours. In addition, the DA2 receptor in E. sinensis may be involved in the physiological regulation of the hepatopancreas and digestive tract after the ingestion of food. This study provides a foundation for further exploration of the light adaptation and digestive functions of the DA2 receptor in decapods. PMID:29554147

Expression of NK cell receptors on decidual T cells in human pregnancy.

PubMed

Tilburgs, Tamara; van der Mast, Barbara J; Nagtzaam, Nicole M A; Roelen, Dave L; Scherjon, Sicco A; Claas, Frans H J

2009-06-01

Specific receptors enable NK cells to discriminate between cells with normal expression of MHC class I and cells that have low or absent expression of MHC class I molecules. In addition to NK cells, these receptors can be expressed on T cell subsets, mainly on CD8+ T cells but also on gammadeltaTCR+ T cells and CD4+ T cells. Although the function of NK cell receptor expression on T cells is not completely understood, various studies have shown that they are involved in down regulation of T cell receptor (TCR)-mediated activation and influence effector functions, like cytotoxicity and cytokine production. The aim of this study was to analyze expression of NK cell receptors on peripheral blood and decidual T cells during human pregnancy using flow cytometry. We demonstrate that a proportion of decidual T cells express HLA-C specific killer immunoglobulin-like receptors (KIRs). Furthermore, a small proportion of decidual T cells express the HLA-E specific CD94-NKG2A inhibitory and CD94-NKG2C activating receptors. Decidual KIR+ and CD94-NKG2+ T cells mainly display a CD3+CD4-CD8- phenotype. However, decidual tissue also contains higher percentages of KIR and CD94-NKG2 expressing CD4+ and CD8+ T cells compared to peripheral blood. So far, the functional capacities of decidual T cells expressing the NK cell receptors are unknown but NK cell receptor expression on decidual T cells may provide an alternative means by which decidual T cells distinguish self (maternal) cells from allogeneic fetal cells, and act to modulate the decidual immune response.

Functional expression of cysteinyl leukotriene receptors on human platelets.

PubMed

Hasegawa, Shunji; Ichiyama, Takashi; Hashimoto, Kunio; Suzuki, Yasuo; Hirano, Reiji; Fukano, Reiji; Furukawa, Susumu

2010-01-01

Normal peripheral blood leukocytes, such as basophils, eosinophils, B lymphocytes and monocytes/macrophages, have a cysteinyl leukotriene 1 (CysLT1) receptor, while the cysteinyl leukotriene 2 (CysLT2) receptor is expressed in cardiac Purkinje cells, endothelium, brain and leukocytes. However, it is unknown whether or not platelets express the CysLT1 or CysLT2 receptor. In this study we identify and characterize the biological function of the CysLT receptor of human platelets. We determined the CysLT1 or CysLT2 receptor mRNA expression in normal human platelets by RT-PCR and determined protein expression by Western blotting and flow cytometry. Moreover, we examined the effect of cysteinyl leukotrienes (CysLTs) in platelets on the induction of RANTES (Regulated on Activation, Normal T Expressed, and presumably Secreted). We also investigated whether the CysLT1 receptor antagonist pranlukast inhibits CysLT-induced RANTES release. In conclusion, we showed the functional expression of CysLT receptors on human platelets and demonstrated that CysLTs induced the release of significant amounts of RANTES, which suggests a novel role for human platelets in CysLT-mediated allergic inflammation.

Naturally occurring glucagon-like peptide-2 (GLP-2) receptors in human intestinal cell lines.

PubMed

Sams, Anette; Hastrup, Sven; Andersen, Marie; Thim, Lars

2006-02-17

Although clinical trials with GLP-2 receptor agonists are currently ongoing, the mechanisms behind GLP-2-induced intestinal epithelial growth remain to be understood. To approach the GLP-2 mechanism of action this study aimed to identify intestinal cell lines endogenously expressing the GLP-2 receptor. Here we report the first identification of a cell line endogenously expressing functional GLP-2 receptors. The human intestinal epithelial cell line, FHC, expressed GLP-2 receptor encoding mRNA (RT-PCR) and GLP-2 receptor protein (Western blot). In cultured FHC cells, GLP-2 induced concentration dependent cAMP accumulation (pEC(50)=9.7+/-0.04 (mean+/-S.E.M., n=4)). In addition, a naturally occurring human intestinal fibroblast cell line, 18Co, endogenously expressing GLP-2 receptor encoding mRNA (RT-PCR) and protein (Western blot) was identified. No receptor functionality (binding or G-protein signalling) could be demonstrated in 18Co cells. The identified gut-relevant cell lines provide tools for future clarification of the mechanisms underlying GLP-2-induced epithelial growth.

A Subset of Mouse Colonic Goblet Cells Expresses the Bitter Taste Receptor Tas2r131

PubMed Central

Prandi, Simone; Bromke, Marta; Hübner, Sandra; Voigt, Anja; Boehm, Ulrich; Meyerhof, Wolfgang; Behrens, Maik

2013-01-01

The concept that gut nutrient sensing involves taste receptors has been fueled by recent reports associating the expression of taste receptors and taste-associated signaling molecules in the gut and in gut-derived cell lines with physiological responses induced by known taste stimuli. However, for bitter taste receptors (Tas2rs), direct evidence for their functional role in gut physiology is scarce and their cellular expression pattern remained unknown. We therefore investigated Tas2r expression in mice. RT-PCR experiments assessed the presence of mRNA for Tas2rs and taste signaling molecules in the gut. A gene-targeted mouse strain was established to visualize and identify cell types expressing the bitter receptor Tas2r131. Messenger RNA for various Tas2rs and taste signaling molecules were detected by RT-PCR in the gut. Using our knock-in mouse strain we demonstrate that a subset of colonic goblet cells express Tas2r131. Cells that express this receptor are absent in the upper gut and do not correspond to enteroendocrine and brush cells. Expression in colonic goblet cells is consistent with a role of Tas2rs in defense mechanisms against potentially harmful xenobiotics. PMID:24367558

Sequential expression of cyclooxygenase-2, glutamate receptor-2, and platelet activating factor receptor in rat hippocampal neurons after fluid percussion injury

PubMed Central

Li, Zhiqiang; Shu, Qingming; Li, Lingzhi; Ge, Maolin; Zhang, Yongliang

2014-01-01

Traumatic brain injury causes gene expression changes in different brain regions. Occurrence and development of traumatic brain injury are closely related, involving expression of three factors, namely cyclooxygenase-2, glutamate receptor-2, and platelet activating factor receptor. However, little is known about the correlation of these three factors and brain neuronal injury. In this study, primary cultured rat hippocampal neurons were subjected to fluid percussion injury according to Scott's method, with some modifications. RT-PCR and semi-quantitative immunocytochemical staining was used to measure the expression levels of cyclooxygenase-2, glutamate receptor-2, and platelet activating factor receptor. Our results found that cyclooxygenase-2 expression were firstly increased post-injury, and then decreased. Both mRNA and protein expression levels reached peaks at 8 and 12 hours post-injury, respectively. Similar sequential changes in glutamate receptor 2 were observed, with highest levels mRNA and protein expression at 8 and 12 hours post-injury respectively. On the contrary, the expressions of platelet activating factor receptor were firstly decreased post-injury, and then increased. Both mRNA and protein expression levels reached the lowest levels at 8 and 12 hours post-injury, respectively. Totally, our findings suggest that these three factors are involved in occurrence and development of hippocampal neuronal injury. PMID:25206921

Expression of the tachykinin receptor mRNAs in healthy human colon.

PubMed

Jaafari, Nadia; Hua, Guoqiang; Adélaïde, José; Julé, Yvon; Imbert, Jean

2008-12-03

Tachykinins are a family of neuropeptides, involved in a variety of physiological and pathological processes occurring in the gastrointestinal tract. They act via three distinct types of receptors, tachykinin NK(1), NK(2), and NK(3) receptors, which belong to the family of G protein-coupled receptors. The aim of the present study was to characterize, for the first time in the healthy human colon, the TACR(1), TACR(2) and TACR(3) mRNAs encoding the three different tachykinin receptors and to measure their relative expression by quantitative reverse transcription-PCR assay. Our results confirm the broad distribution of the tachykinin receptors but evidenced significant differences in the expression level of their respective mRNAs. A higher expression level of the TACR2 mRNA alpha isoform, the gene encoding the functional tachykinin NK(2) receptor, was observed in comparison to TACR1 and TACR3 mRNAs genes encoding for NK(1) and NK(3) receptors respectively. The prevalence of the TACR2 mRNA alpha isoform strongly suggests a major involvement of tachykinin NK(2) receptor in the regulation of human colonic functions.

Embryonic expression of the transforming growth factor beta ligand and receptor genes in chicken.

PubMed

Cooley, James R; Yatskievych, Tatiana A; Antin, Parker B

2014-03-01

Transforming growth factor-beta (TGFβ) signaling regulates a myriad of biological processes during embryogenesis, in the adult, and during the manifestation of disease. TGFβ signaling is propagated through one of three TGFβ ligands interacting with Type I and Type II receptors, and Type III co-receptors. Although TGFβ signaling is regulated partly by the combinatorial expression patterns of TGFβ receptors and ligands, a comprehensive gene expression analysis has not been published. Here we report the embryonic mRNA expression patterns in chicken embryos of the canonical TGFβ ligands (TGFB1, TGFB2, and TGFB3) and receptors (TGFBR1, TGFBR2, TGFBR3), plus the Activin A receptor, type 1 (ACVR1) and co receptor Endoglin (ENG) that also transduce TGFβ signaling. TGFB ligands and receptors show dynamic and frequently overlapping expression patterns in numerous embryonic cell layers and structures. Integrating expression information identifies combinations of ligands and receptors that are involved in specific developmental processes including somitogenesis, cardiogenesis and vasculogenesis. Copyright © 2013 Wiley Periodicals, Inc.

Hypoxia attenuates purinergic P2X receptor-induced inflammatory gene expression in brainstem microglia

PubMed Central

Smith, Stephanie MC; Mitchell, Gordon S; Friedle, Scott A; Sibigtroth, Christine M; Vinit, Stéphane; Watters, Jyoti J

2013-01-01

Hypoxia and increased extracellular nucleotides are frequently coincident in the brainstem. Extracellular nucleotides are potent modulators of microglial inflammatory gene expression via P2X purinergic receptor activation. Although hypoxia is also known to modulate inflammatory gene expression, little is known about how hypoxia or P2X receptor activation alone affects inflammatory molecule production in brainstem microglia, nor how hypoxia and P2X receptor signaling interact when they occur together. In the study reported here, we investigated the ability of a brief episode of hypoxia (2 hours) in the presence and absence of the nonselective P2X receptor agonist 2′(3′)-O-(4-benzoylbenzoyl)adenosine-5′-triphosphate (BzATP) to promote inflammatory gene expression in brainstem microglia in adult rats. We evaluated inducible nitric oxide synthase (iNOS), tumor necrosis factor alpha (TNFα), and interleukin (IL)-6 messenger RNA levels in immunomagnetically isolated brainstem microglia. While iNOS and IL-6 gene expression increased with hypoxia and BzATP alone, TNFα expression was unaffected. Surprisingly, BzATP-induced inflammatory effects were lost after hypoxia, suggesting that hypoxia impairs proinflammatory P2X-receptor signaling. We also evaluated the expression of key P2X receptors activated by BzATP, namely P2X1, P2X4, and P2X7. While hypoxia did not alter their expression, BzATP upregulated P2X4 and P2X7 mRNAs; these effects were ablated in hypoxia. Although both P2X4 and P2X7 receptor expression correlated with increased microglial iNOS and IL-6 levels in microglia from normoxic rats, in hypoxia, P2X7 only correlated with IL-6, and P2X4 correlated only with iNOS. In addition, correlations between P2X7 and P2X4 were lost following hypoxia, suggesting that P2X4 and P2X7 receptor signaling differs in normoxia and hypoxia. Together, these data suggest that hypoxia suppresses P2X receptor-induced inflammatory gene expression, indicating a potentially immunosuppressive role of extracellular nucleotides in brainstem microglia following exposure to hypoxia. PMID:24377098

Angiotensin II AT1 receptor blocker candesartan prevents the fast up-regulation of cerebrocortical benzodiazepine-1 receptors induced by acute inflammatory and restraint stress

PubMed Central

Sánchez-Lemus, Enrique; Honda, Masaru; Saavedra, Juan M.

2012-01-01

Centrally acting Angiotensin II AT1 receptor blockers (ARBs) protect from stress-induced disorders and decrease anxiety in a model of inflammatory stress, the systemic injection of bacterial endotoxin lipopolysaccharide (LPS). In order to better understand the anxiolytic effect of ARBs, we treated rats with LPS (50 µg/kg) with or without three days of pretreatment with the ARB candesartan (1 mg/kg/day), and studied cortical benzodiazepine (BZ) and corticotrophin-releasing factor (CRF) receptors. We compared the cortical BZ and CRF receptors expression pattern induced by LPS with that produced in restraint stress. Inflammation stress produced a generalized increase in cortical BZ1 receptors and reduced mRNA expression of the GABAA receptor γ2 subunit in cingulate cortex; changes were prevented by candesartan pretreatment. Moreover, restraint stress produced similar increases in cortical BZ1 receptor binding, and candesartan prevented these changes. Treatment with candesartan alone increased cortical BZ1 binding, and decreased γ2 subunit mRNA expression in the cingulate cortex. Conversely, we did not find changes in CRF1 receptor expression in any of the cortical areas studied, either after inflammation or restraint stress. Cortical CRF2 receptor binding was undetectable, but CRF2 mRNA expression was decreased by inflammation stress, a change prevented by candesartan. We conclude that stress promotes rapid and widespread changes in cortical BZ1 receptor expression; and that the stress-induced BZ1 receptor expression is under the control of AT1 receptor activity. The results suggest that the anti-anxiety effect of ARBs may be associated with their capacity to regulate stress-induced alterations in cortical BZ1 receptors. PMID:22503782

Cocaine-induced adaptation of dopamine D2S, but not D2L autoreceptors

PubMed Central

Radl, Daniela; Borrelli, Emiliana; Williams, John T; Neve, Kim A

2017-01-01

The dopamine D2 receptor has two splice variants, D2S (Short) and D2L (Long). In dopamine neurons, both variants can act as autoreceptors to regulate neuronal excitability and dopamine release, but the roles of each variant are incompletely characterized. In a previous study we used viral receptor expression in D2 receptor knockout mice to show distinct effects of calcium signaling on D2S and D2L autoreceptor function (Gantz et al., 2015). However, the cocaine-induced plasticity of D2 receptor desensitization observed in wild type mice was not recapitulated with this method of receptor expression. Here we use mice with genetic knockouts of either the D2S or D2L variant to investigate cocaine-induced plasticity in D2 receptor signaling. Following a single in vivo cocaine exposure, the desensitization of D2 receptors from neurons expressing only the D2S variant was reduced. This did not occur in D2L-expressing neurons, indicating differential drug-induced plasticity between the variants. PMID:29154756

Cocaine-induced adaptation of dopamine D2S, but not D2L autoreceptors.

PubMed

Robinson, Brooks G; Condon, Alec F; Radl, Daniela; Borrelli, Emiliana; Williams, John T; Neve, Kim A

2017-11-20

The dopamine D2 receptor has two splice variants, D2S (Short) and D2L (Long). In dopamine neurons, both variants can act as autoreceptors to regulate neuronal excitability and dopamine release, but the roles of each variant are incompletely characterized. In a previous study we used viral receptor expression in D2 receptor knockout mice to show distinct effects of calcium signaling on D2S and D2L autoreceptor function (Gantz et al., 2015). However, the cocaine-induced plasticity of D2 receptor desensitization observed in wild type mice was not recapitulated with this method of receptor expression. Here we use mice with genetic knockouts of either the D2S or D2L variant to investigate cocaine-induced plasticity in D2 receptor signaling. Following a single in vivo cocaine exposure, the desensitization of D2 receptors from neurons expressing only the D2S variant was reduced. This did not occur in D2L-expressing neurons, indicating differential drug-induced plasticity between the variants.

Developmental regulation of N-methyl-D-aspartate- and kainate-type glutamate receptor expression in the rat spinal cord

NASA Technical Reports Server (NTRS)

Stegenga, S. L.; Kalb, R. G.

2001-01-01

Spinal motor neurons undergo experience-dependent development during a critical period in early postnatal life. It has been suggested that the repertoire of glutamate receptor subunits differs between young and mature motor neurons and contributes to this activity-dependent development. In the present study we examined the expression patterns of N-methyl-D-aspartate- and kainate-type glutamate receptor subunits during the postnatal maturation of the spinal cord. Young motor neurons express much higher levels of the N-methyl-D-aspartate receptor subunit NR1 than do adult motor neurons. Although there are eight potential splice variants of NR1, only a subgroup is expressed by motor neurons. With respect to NR2 receptor subunits, young motor neurons express NR2A and C, while adult motor neurons express only NR2A. Young motor neurons express kainate receptor subunits GluR5, 6 and KA2 but we are unable to detect these or any other kainate receptor subunits in the adult spinal cord. Other spinal cord regions display a distinct pattern of developmental regulation of N-methyl-D-aspartate and kainate receptor subunit expression in comparison to motor neurons. Our findings indicate a precise spatio-temporal regulation of individual subunit expression in the developing spinal cord. Specific combinations of subunits in developing neurons influence their excitable properties and could participate in the emergence of adult neuronal form and function.

Dopamine D2 receptor expression in the corticotroph cells of the human normal pituitary gland.

PubMed

Pivonello, Rosario; Waaijers, Marlijn; Kros, Johan M; Pivonello, Claudia; de Angelis, Cristina; Cozzolino, Alessia; Colao, Annamaria; Lamberts, Steven W J; Hofland, Leo J

2017-08-01

The dopamine D 2 receptor is the main dopamine receptor expressed in the human normal pituitary gland. The aim of the current study was to evaluate dopamine D 2 receptor expression in the corticotroph cell populations of the anterior lobe and pars intermedia, as well as posterior lobe of the human normal pituitary gland by immunohistochemistry. Human normal pituitary gland samples obtained from routine autopsies were used for the study. In all cases, histology together with immunostaining for adrenocorticotropic hormone, melanocyte-stimulating hormone, prolactin, and neurofilaments were performed and compared to the immunostaining for D 2 receptor. D 2 receptor was heterogeneously expressed in the majority of the cell populations of the anterior and posterior lobe as well as in the area localized between the anterior and posterior lobe, and arbitrary defined as "intermediate zone". This zone, characterized by the presence of nerve fibers included the residual pars intermedia represented by the colloid-filled cysts lined by the remnant melanotroph cells strongly expressing D 2 receptors, and clusters of corticotroph cells, belonging to the anterior lobe but localized within the cysts and adjacent to the posterior lobe, variably expressing D 2 receptors. D 2 dopamine receptor is expressed in the majority of the cell populations of the human normal pituitary gland, and particularly, in the different corticotroph cell populations localized in the anterior lobe and the intermediate zone of the pituitary gland.

Overlapping but distinct topology for zebrafish V2R-like olfactory receptors reminiscent of odorant receptor spatial expression zones.

PubMed

Ahuja, Gaurav; Reichel, Vera; Kowatschew, Daniel; Syed, Adnan S; Kotagiri, Aswani Kumar; Oka, Yuichiro; Weth, Franco; Korsching, Sigrun I

2018-05-23

The sense of smell is unrivaled in terms of molecular complexity of its input channels. Even zebrafish, a model vertebrate system in many research fields including olfaction, possesses several hundred different olfactory receptor genes, organized in four different gene families. For one of these families, the initially discovered odorant receptors proper, segregation of expression into distinct spatial subdomains within a common sensory surface has been observed both in teleost fish and in mammals. However, for the remaining three families, little to nothing was known about their spatial coding logic. Here we wished to investigate, whether the principle of spatial segregation observed for odorant receptors extends to another olfactory receptor family, the V2R-related OlfC genes. Furthermore we thought to examine, how expression of OlfC genes is integrated into expression zones of odorant receptor genes, which in fish share a single sensory surface with OlfC genes. To select representative genes, we performed a comprehensive phylogenetic study of the zebrafish OlfC family, which identified a novel OlfC gene, reduced the number of pseudogenes to 1, and brought the total family size to 60 intact OlfC receptors. We analyzed the spatial pattern of OlfC-expressing cells for seven representative receptors in three dimensions (height within the epithelial layer, horizontal distance from the center of the olfactory organ, and height within the olfactory organ). We report non-random distributions of labeled neurons for all OlfC genes analysed. Distributions for sparsely expressed OlfC genes are significantly different from each other in nearly all cases, broad overlap notwithstanding. For two of the three coordinates analyzed, OlfC expression zones are intercalated with those of odorant receptor zones, whereas in the third dimension some segregation is observed. Our results show that V2R-related OlfC genes follow the same spatial logic of expression as odorant receptors and their expression zones intermingle with those of odorant receptor genes. Thus, distinctly different expression zones for individual receptor genes constitute a general feature shared by teleost and tetrapod V2R/OlfC and odorant receptor families alike.

Expression of Cannabinoid Receptors in Human Osteoarthritic Cartilage: Implications for Future Therapies.

PubMed

Dunn, Sara L; Wilkinson, Jeremy Mark; Crawford, Aileen; Bunning, Rowena A D; Le Maitre, Christine L

2016-01-01

Introduction: Cannabinoids have shown to reduce joint damage in animal models of arthritis and reduce matrix metalloproteinase expression in primary human osteoarthritic (OA) chondrocytes. The actions of cannabinoids are mediated by a number of receptors, including cannabinoid receptors 1 and 2 (CB1 and CB2), G-protein-coupled receptors 55 and 18 (GPR55 and GPR18), transient receptor potential vanilloid-1 (TRPV1), and peroxisome proliferator-activated receptors alpha and gamma (PPARα and PPARγ). However, to date very few studies have investigated the expression and localization of these receptors in human chondrocytes, and expression during degeneration, and thus their potential in clinical applications is unknown. Methods: Human articular cartilage from patients with symptomatic OA was graded histologically and the expression and localization of cannabinoid receptors within OA cartilage and underlying bone were determined immunohistochemically. Expression levels across regions of cartilage and changes with degeneration were investigated. Results: Expression of all the cannabinoid receptors investigated was observed with no change with grade of degeneration seen in the expression of CB1, CB2, GPR55, PPARα, and PPARγ. Conversely, the number of chondrocytes within the deep zone of cartilage displaying immunopositivity for GPR18 and TRPV1 was significantly decreased in degenerate cartilage. Receptor expression was higher in chondrocytes than in osteocytes in the underlying bone. Conclusions: Chondrocytes from OA joints were shown to express a wide range of cannabinoid receptors even in degenerate tissues, demonstrating that these cells could respond to cannabinoids. Cannabinoids designed to bind to receptors inhibiting the catabolic and pain pathways within the arthritic joint, while avoiding psychoactive effects, could provide potential arthritis therapies.

Differential expression of the P2X7 receptor in ovarian surface epithelium during the oestrous cycle in the mouse.

PubMed

Vázquez-Cuevas, F G; Cruz-Rico, A; Garay, E; García-Carrancá, A; Pérez-Montiel, D; Juárez, B; Arellano, R O

2013-01-01

Purinergic signalling has been proposed as an intraovarian regulatory mechanism. Of the receptors responsible for purinergic transmission, the P2X7 receptor is an ATP-gated cationic channel that displays a broad spectrum of cellular functions ranging from apoptosis to cell proliferation and tumourigenesis. In the present study, we investigated the functional expression of P2X7 receptors in ovarian surface epithelium (OSE). P2X7 protein was detected in the OSE layer of the mouse, both in situ and in primary cultures. In cultures, 2'(3')-O-(4-Benzoylbenzoyl)adenosine-5'-triphosphate (BzATP) activation of P2X7 receptors increased [Ca(2+)]i and induced apoptosis. The functionality of the P2X7 receptor was investigated in situ by intrabursal injection of BzATP on each day of the oestrous cycle and evaluation of apoptosis 24h using the terminal deoxyribonucleotidyl transferase-mediated dUTP-fluorescein nick end-labelling (TUNEL) assay. Maximum effects of BzATP were observed during pro-oestrus, with the effects being blocked by A438079, a specific P2X7 receptor antagonist. Immunofluorescence staining for P2X7 protein revealed more robust expression during pro-oestrus and in OSE regions behind the antral follicles, strongly supporting the notion that the differences in apoptosis can be explained by increased receptor expression, which is regulated during the oestrous cycle. Finally, P2X7 receptor expression was detected in the OSE layer of human ovaries, with receptor expression maintained in human ovaries diagnosed with cancer, as well as in the human ovarian carcinoma SKOV3 cell line.

Differential expression and role of hyperglycemia induced oxidative stress in epigenetic regulation of β1, β2 and β3-adrenergic receptors in retinal endothelial cells

PubMed Central

2014-01-01

Background Aberrant epigenetic profiles are concomitant with a spectrum of developmental defects and diseases. Role of methylation is an increasingly accepted factor in the pathophysiology of diabetes and its associated complications. This study aims to examine the correlation between oxidative stress and methylation of β1, β2 and β3-adrenergic receptors and to analyze the differential variability in the expression of these genes under hyperglycemic conditions. Methods Human retinal endothelial cells were cultured in CSC complete medium in normal (5 mM) or high (25 mM) glucose to mimic a diabetic condition. Reverse transcription PCR and Western Blotting were performed to examine the expression of β1, β2 and β3-adrenergic receptors. For detections, immunocytochemistry was used. Bisulfite sequencing method was used for promoter methylation analysis. Apoptosis was determined by the terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay. Dichlorodihydrofluorescein diacetate (DCFH-DA) assay was used to measure reactive oxygen species (ROS) production in the cells. Results β1 and β3-adrenergic receptors were expressed in retinal endothelial cells while β2-adrenergic receptor was not detectable both at protein and mRNA levels. Hyperglycemia had no significant effect on β1 and β2-adrenergic receptors methylation and expression however β3-adrenergic receptors showed a significantly higher expression (p < 0.05) and methylation (p < 0.01) in high and low glucose concentration respectively. Apoptosis and oxidative stress were inversely correlated with β3-adrenergic receptors methylation with no significant effect on β1 and β2-adrenergic receptors. β2-adrenergic receptor was hypermethylated with halted expression. Conclusion Our study demonstrates that β1 and β3-adrenergic receptors expressed in human retinal endothelial cells. Oxidative stress and apoptosis are inversely proportional to the extent of promoter methylation, suggesting that methylation loss might be due to oxidative stress-induced DNA damage. PMID:24885710

Functional Expression of Two Neuronal Nicotinic Acetylcholine Receptors from cDNA Clones Identifies a Gene Family

NASA Astrophysics Data System (ADS)

Boulter, Jim; Connolly, John; Deneris, Evan; Goldman, Dan; Heinemann, Steven; Patrick, Jim

1987-11-01

A family of genes coding for proteins homologous to the α subunit of the muscle nicotinic acetylcholine receptor has been identified in the rat genome. These genes are transcribed in the central and peripheral nervous systems in areas known to contain functional nicotinic receptors. In this paper, we demonstrate that three of these genes, which we call alpha3, alpha4, and beta2, encode proteins that form functional nicotinic acetylcholine receptors when expressed in Xenopus oocytes. Oocytes expressing either alpha3 or alpha4 protein in combination with the beta2 protein produced a strong response to acetylcholine. Oocytes expressing only the alpha4 protein gave a weak response to acetylcholine. These receptors are activated by acetylcholine and nicotine and are blocked by Bungarus toxin 3.1. They are not blocked by α -bungarotoxin, which blocks the muscle nicotinic acetylcholine receptor. Thus, the receptors formed by the alpha3, alpha4, and beta2 subunits are pharmacologically similar to the ganglionic-type neuronal nicotinic acetylcholine receptor. These results indicate that the alpha3, alpha4, and beta2 genes encode functional nicotinic acetylcholine receptor subunits that are expressed in the brain and peripheral nervous system.

Expression of Plant Receptor Kinases in Tobacco BY-2 Cells.

PubMed

Shinohara, Hidefumi; Matsubayashi, Yoshikatsu

2017-01-01

Although more than 600 single-transmembrane receptor kinase genes have been found in the Arabidopsis genome, only a few of them have known physiological functions, and even fewer plant receptor kinases have known specific ligands. Ligand-binding analysis must be operated using the functionally expressed receptor form. However, the relative abundance of native receptor kinase molecules in the plasma membrane is often quite low. Here, we present a method for stable and functional expression of plant receptor kinases in tobacco BY-2 cells that allows preparation of microsomal fractions containing the receptor. This procedure provides a sufficient amount of receptor proteins while maintaining its ligand-binding activities.

Effect of hypobaric hypoxia on the P2X receptors of pyramidal cells in the immature rat hippocampus CA1 sub-field.

PubMed

Zhao, Yan-Dong; Cheng, Sai-Yu; Ou, Shan; Xiao, Zhi; He, Wen-Juan; Jian-Cui; Ruan, Huai-Zhen

2012-01-01

This study was designed to evaluate the effect of hypobaric hypoxia (HH) on the function and expression of P2X receptors in rat hippocampus CA1 pyramidal cells. The functional changes of P2X receptors were investigated through the cell HH model and the expressional alterations of P2X receptors were observed through the animal HH model. P2X receptors mediated currents were recorded from the freshly dissociated CA1 pyramidal cells of 7-day-old SD rats by whole cell patch clamp recording. The expression and distribution of P2X receptors were observed through immunohistochemistry and western blot at HH 3-day and 7-day. In acute HH conditions, the amplitudes of ATP evoked peak currents were decreased compared to control. The immunohistochemistry and western blot results reflected there was no change in P2X receptors expression after 3 days HH injury, while P2X receptors expression was up-regulated in response to 7 days HH injury. These findings supported the possibility that the function of P2X receptors was sensitive to HH damage and long-term function decrease should result in the expression increase of P2X receptors.

P2X receptors in the cardiovascular system and their potential as therapeutic targets in disease.

PubMed

Ralevic, Vera

2015-01-01

This review considers the expression and roles of P2X receptors in the cardiovascular system in health and disease and their potential as therapeutic targets. P2X receptors are ligand gated ion channels which are activated by the endogenous ligand ATP. They are formed from the assembly of three P2X subunit proteins from the complement of seven (P2X1-7), which can associate to form homomeric or heteromeric P2X receptors. The P2X1 receptor is widely expressed in the cardiovascular system, being located in the heart, in the smooth muscle of the majority of blood vessels and in platelets. P2X1 receptors expressed in blood vessels can be activated by ATP coreleased with noradrenaline as a sympathetic neurotransmitter, leading to smooth muscle depolarisation and contraction. There is evidence that the purinergic component of sympathetic neurotransmission is increased in hypertension, identifying P2X1 receptors as a possible therapeutic target in this disorder. P2X3 and P2X2/3 receptors are expressed on cardiac sympathetic neurones and may, through positive feedback of neuronal ATP at this prejunctional site, amplify sympathetic neurotransmission. Activation of P2X receptors expressed in the heart increases cardiac myocyte contractility, and an important role of the P2X4 receptor in this has been identified. Deletion of P2X4 receptors in the heart depresses contractile performance in models of heart failure, while overexpression of P2X4 receptors has been shown to be cardioprotective, thus P2X4 receptors may be therapeutic targets in the treatment of heart disease. P2X receptors have been identified on endothelial cells. Although immunoreactivity for all P2X1-7 receptor proteins has been shown on the endothelium, relatively little is known about their function, with the exception of the endothelial P2X4 receptor, which has been shown to mediate endothelium-dependent vasodilatation to ATP released during shear stress. The potential of P2X receptors as therapeutic targets in the treatment of cardiovascular disease is discussed.

Captodiamine, a putative antidepressant, enhances hypothalamic BDNF expression in vivo by synergistic 5-HT2c receptor antagonism and sigma-1 receptor agonism.

PubMed

Ring, Rebecca M; Regan, Ciaran M

2013-10-01

The putative antidepressant captodiamine is a 5-HT2c receptor antagonist and agonist at sigma-1 and D3 dopamine receptors, exerts an anti-immobility action in the forced swim paradigm, and enhances dopamine turnover in the frontal cortex. Captodiamine has also been found to ameliorate stress-induced anhedonia, reduce the associated elevations of hypothalamic corticotrophin-releasing factor (CRF) and restore the reductions in hypothalamic BDNF expression. Here we demonstrate chronic administration of captodiamine to have no significant effect on hypothalamic CRF expression through sigma-1 receptor agonism; however, both sigma-1 receptor agonism or 5-HT2c receptor antagonism were necessary to enhance BDNF expression. Regulation of BDNF expression by captodiamine was associated with increased phosphorylation of transcription factor CREB and mediated through sigma-1 receptor agonism but blocked by 5-HT2c receptor antagonism. The existence of two separate signalling pathways was confirmed by immunolocalisation of each receptor to distinct cell populations in the paraventricular nucleus of the hypothalamus. Increased BDNF induced by captodiamine was also associated with enhanced expression of synapsin, but not PSD-95, suggesting induction of long-term structural plasticity between hypothalamic synapses. These unique features of captodiamine may contribute to its ability to ameliorate stress-induced anhedonia as the hypothalamus plays a prominent role in regulating HPA axis activity.

Dopamine D2 Antagonist-Induced Striatal Nur77 Expression Requires Activation of mGlu5 Receptors by Cortical Afferents

PubMed Central

Maheux, Jérôme; St-Hilaire, Michel; Voyer, David; Tirotta, Emanuele; Borrelli, Emiliana; Rouillard, Claude; Rompré, Pierre-Paul; Lévesque, Daniel

2012-01-01

Dopamine D2 receptor antagonists modulate gene transcription in the striatum. However, the molecular mechanism underlying this effect remains elusive. Here we used the expression of Nur77, a transcription factor of the orphan nuclear receptor family, as readout to explore the role of dopamine, glutamate, and adenosine receptors in the effect of a dopamine D2 antagonist in the striatum. First, we investigated D2 antagonist-induced Nur77 mRNA in D2L receptor knockout mice. Surprisingly, deletion of the D2L receptor isoform did not reduce eticlopride-induced upregulation of Nur77 mRNA levels in the striatum. Next, we tested if an ibotenic acid-induced cortical lesion could block the effect of eticlopride on Nur77 expression. Cortical lesions strongly reduced eticlopride-induced striatal upregulation of Nur77 mRNA. Then, we investigated if glutamatergic neurotransmission could modulate eticlopride-induced Nur77 expression. A combination of a metabotropic glutamate type 5 (mGlu5) and adenosine A2A receptor antagonists abolished eticlopride-induced upregulation of Nur77 mRNA levels in the striatum. Direct modulation of Nur77 expression by striatal glutamate and adenosine receptors was confirmed using corticostriatal organotypic cultures. Taken together, these results indicate that blockade of postsynaptic D2 receptors is not sufficient to trigger striatal transcriptional activity and that interaction with corticostriatal presynaptic D2 receptors and subsequent activation of postsynaptic glutamate and adenosine receptors in the striatum is required. Thus, these results uncover an unappreciated role of presynaptic D2 heteroreceptors and support a prominent role of glutamate in the effect of D2 antagonists. PMID:22912617

Expression patterns of lectin-like natural killer receptors, inhibitory CD94/NKG2A, and activating CD94/NKG2C on decidual CD56bright natural killer cells differ from those on peripheral CD56dim natural killer cells.

PubMed

Kusumi, Maki; Yamashita, Takahiro; Fujii, Tomoyuki; Nagamatsu, Takeshi; Kozuma, Shiro; Taketani, Yuji

2006-06-01

The balance of inhibitory and activating natural killer (NK) receptors on maternal decidual NK cells, most of which are CD56bright, is thought to be crucial for the proper growth of trophoblasts in placenta. A lectin-like NK receptor, CD94/NKG2, is the receptor for human leukocyte antigen (HLA)-E, which is expressed on trophoblasts. To clarify the mechanism regulating the activity of decidual NK cells during pregnancy, we investigated the expression patterns of inhibitory NK receptor, CD94/NKG2A, and activating receptor, CD94/NKG2C, on decidual NK cells in an early stage of normal pregnancy and compared them with those on peripheral NK cells, most of which are CD56dim. The rate of NKG2A-positive cells was significantly higher for decidual CD56bright NK cells than for peripheral CD56dim NK cells, but the rates of NKG2C-positive cells were comparable between the two cell types. Interestingly, peripheral CD56dim NK cells reciprocally expressed inhibitory NKG2A and activating NKG2C, but decidual CD56bright NK cells that expressed activating NKG2C simultaneously expressed inhibitory NKG2A. The co-expression of inhibitory and activating NKG2 receptors may fine-tune the immunoregulatory functions of the decidual NK cells to control the trophoblast invasion in constructing placenta.

Differential adipokine receptor expression on circulating leukocyte subsets in lean and obese children.

PubMed

Keustermans, Genoveva; van der Heijden, Laila B; Boer, Berlinda; Scholman, Rianne; Nuboer, Roos; Pasterkamp, Gerard; Prakken, Berent; de Jager, Wilco; Kalkhoven, Eric; Janse, Arieke J; Schipper, Henk S

2017-01-01

Childhood obesity prevalence has increased worldwide and is an important risk factor for type 2 diabetes (T2D) and cardiovascular disease (CVD). The production of inflammatory adipokines by obese adipose tissue contributes to the development of T2D and CVD. While levels of circulating adipokines such as adiponectin and leptin have been established in obese children and adults, the expression of adiponectin and leptin receptors on circulating immune cells can modulate adipokine signalling, but has not been studied so far. Here, we aim to establish the expression of adiponectin and leptin receptors on circulating immune cells in obese children pre and post-lifestyle intervention compared to normal weight control children. 13 obese children before and after a 1-year lifestyle intervention were compared with an age and sex-matched normal weight control group of 15 children. Next to routine clinical and biochemical parameters, circulating adipokines were measured, and flow cytometric analysis of adiponectin receptor 1 and 2 (AdipoR1, AdipoR2) and leptin receptor expression on peripheral blood mononuclear cell subsets was performed. Obese children exhibited typical clinical and biochemical characteristics compared to controls, including a higher BMI-SD, blood pressure and circulating leptin levels, combined with a lower insulin sensitivity index (QUICKI). The 1-year lifestyle intervention resulted in stabilization of their BMI-SD. Overall, circulating leukocyte subsets showed distinct adipokine receptor expression profiles. While monocytes expressed high levels of all adipokine receptors, NK and iNKT cells predominantly expressed AdipoR2, and B-lymphocytes and CD4+ and CD8+ T-lymphocyte subsets expressed AdipoR2 as well as leptin receptor. Strikingly though, leukocyte subset numbers and adipokine receptor expression profiles were largely similar in obese children and controls. Obese children showed higher naïve B-cell numbers, and pre-intervention also higher numbers of immature transition B-cells and intermediate CD14++CD16+ monocytes combined with lower total monocyte numbers, compared to controls. Furthermore, adiponectin receptor 1 expression on nonclassical CD14+CD16++ monocytes was consistently upregulated in obese children pre-intervention, compared to controls. However, none of the differences in leukocyte subset numbers and adipokine receptor expression profiles between obese children and controls remained significant after multiple testing correction. First, the distinct adipokine receptor profiles of circulating leukocyte subsets may partly explain the differential impact of adipokines on leukocyte subsets. Second, the similarities in adipokine receptor expression profiles between obese children and normal weight controls suggest that adipokine signaling in childhood obesity is primarily modulated by circulating adipokine levels, instead of adipokine receptor expression.

A2BR Adenosine Receptor Modulates Sweet Taste in Circumvallate Taste Buds

PubMed Central

Yang, Dan; Shultz, Nicole; Vandenbeuch, Aurelie; Ravid, Katya; Kinnamon, Sue C.; Finger, Thomas E.

2012-01-01

In response to taste stimulation, taste buds release ATP, which activates ionotropic ATP receptors (P2X2/P2X3) on taste nerves as well as metabotropic (P2Y) purinergic receptors on taste bud cells. The action of the extracellular ATP is terminated by ectonucleotidases, ultimately generating adenosine, which itself can activate one or more G-protein coupled adenosine receptors: A1, A2A, A2B, and A3. Here we investigated the expression of adenosine receptors in mouse taste buds at both the nucleotide and protein expression levels. Of the adenosine receptors, only A2B receptor (A2BR) is expressed specifically in taste epithelia. Further, A2BR is expressed abundantly only in a subset of taste bud cells of posterior (circumvallate, foliate), but not anterior (fungiform, palate) taste fields in mice. Analysis of double-labeled tissue indicates that A2BR occurs on Type II taste bud cells that also express Gα14, which is present only in sweet-sensitive taste cells of the foliate and circumvallate papillae. Glossopharyngeal nerve recordings from A2BR knockout mice show significantly reduced responses to both sucrose and synthetic sweeteners, but normal responses to tastants representing other qualities. Thus, our study identified a novel regulator of sweet taste, the A2BR, which functions to potentiate sweet responses in posterior lingual taste fields. PMID:22253866

A2BR adenosine receptor modulates sweet taste in circumvallate taste buds.

PubMed

Kataoka, Shinji; Baquero, Arian; Yang, Dan; Shultz, Nicole; Vandenbeuch, Aurelie; Ravid, Katya; Kinnamon, Sue C; Finger, Thomas E

2012-01-01

In response to taste stimulation, taste buds release ATP, which activates ionotropic ATP receptors (P2X2/P2X3) on taste nerves as well as metabotropic (P2Y) purinergic receptors on taste bud cells. The action of the extracellular ATP is terminated by ectonucleotidases, ultimately generating adenosine, which itself can activate one or more G-protein coupled adenosine receptors: A1, A2A, A2B, and A3. Here we investigated the expression of adenosine receptors in mouse taste buds at both the nucleotide and protein expression levels. Of the adenosine receptors, only A2B receptor (A2BR) is expressed specifically in taste epithelia. Further, A2BR is expressed abundantly only in a subset of taste bud cells of posterior (circumvallate, foliate), but not anterior (fungiform, palate) taste fields in mice. Analysis of double-labeled tissue indicates that A2BR occurs on Type II taste bud cells that also express Gα14, which is present only in sweet-sensitive taste cells of the foliate and circumvallate papillae. Glossopharyngeal nerve recordings from A2BR knockout mice show significantly reduced responses to both sucrose and synthetic sweeteners, but normal responses to tastants representing other qualities. Thus, our study identified a novel regulator of sweet taste, the A2BR, which functions to potentiate sweet responses in posterior lingual taste fields.

Induction of cyclooxygenase-2 expression by prostaglandin E2 stimulation of the prostanoid EP4 receptor via coupling to Gαi and transactivation of the epidermal growth factor receptor in HCA-7 human colon cancer cells.

PubMed

Yoshida, Kenji; Fujino, Hiromichi; Otake, Sho; Seira, Naofumi; Regan, John W; Murayama, Toshihiko

2013-10-15

Increased expressions of cyclooxygenase-2 (COX-2) and its downstream metabolite, prostaglandin E2 (PGE2), are well documented events in the development of colorectal cancer. Interestingly, PGE2 itself can induce the expression of COX-2 thereby creating the potential for positive feedback. Although evidence for such a positive feedback has been previously described, the specific E-type prostanoid (EP) receptor subtype that mediates this response, as well as the relevant signaling pathways, remain unclear. We now report that the PGE2 stimulated induction of COX-2 expression in human colon cancer HCA-7 cells is mediated by activation of the prostanoid EP4 receptor subtype and is followed by coupling of the receptor to Gαi and the activation of phosphatidylinositol 3-kinase. Subsequent activation of metalloproteinases releases membrane bound heparin-binding epidermal growth factor-like growth factor resulting in the transactivation of epidermal growth factor receptors and the activation of the extracellular signal-regulated kinases and induction of COX-2 expression. This induction of COX-2 expression by PGE2 stimulation of the prostanoid EP4 receptor may underlie the upregulation of COX-2 during colorectal cancer and appears to be an early event in the process of tumorigenesis. © 2013 Elsevier B.V. All rights reserved.

Inhibitory effects of two G protein-coupled receptor kinases on the cell surface expression and signaling of the human adrenomedullin receptor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuwasako, Kenji, E-mail: kuwasako@med.miyazaki-u.ac.jp; Sekiguchi, Toshio; Nagata, Sayaka

2016-02-19

Receptor activity-modifying protein 2 (RAMP2) enables the calcitonin receptor-like receptor (CLR, a family B GPCR) to form the type 1 adrenomedullin receptor (AM{sub 1} receptor). Here, we investigated the effects of the five non-visual GPCR kinases (GRKs 2 through 6) on the cell surface expression of the human (h)AM{sub 1} receptor by cotransfecting each of these GRKs into HEK-293 cells that stably expressed hRAMP2. Flow cytometric analysis revealed that when coexpressed with GRK4 or GRK5, the cell surface expression of the AM{sub 1} receptor was markedly decreased prior to stimulation with AM, thereby attenuating both the specific [{sup 125}I]AM binding andmore » AM-induced cAMP production. These inhibitory effects of both GRKs were abolished by the replacement of the cytoplasmic C-terminal tail (C-tail) of CLR with that of the calcitonin receptor (a family B GPCR) or β{sub 2}-adrenergic receptor (a family A GPCR). Among the sequentially truncated CLR C-tail mutants, those lacking the five residues 449–453 (Ser-Phe-Ser-Asn-Ser) abolished the inhibition of the cell surface expression of CLR via the overexpression of GRK4 or GRK5. Thus, we provided new insight into the function of GRKs in agonist-unstimulated GPCR trafficking using a recombinant AM{sub 1} receptor and further determined the region of the CLR C-tail responsible for this GRK function. - Highlights: • We discovered a novel function of GRKs in GPCR trafficking using human CLR/RAMP2. • GRKs 4 and 5 markedly inhibited the cell surface expression of human CLR/RAMP2. • Both GRKs exhibited highly significant receptor signaling inhibition. • Five residues of the C-terminal tail of CLR govern this function of GRKs.« less

Estrogen Receptor-Related Receptor α Mediates Up-Regulation of Aromatase Expression by Prostaglandin E2 in Prostate Stromal Cells

PubMed Central

Miao, Lin; Shi, Jiandang; Wang, Chun-Yu; Zhu, Yan; Du, Xiaoling; Jiao, Hongli; Mo, Zengnan; Klocker, Helmut; Lee, Chung; Zhang, Ju

2010-01-01

Estrogen receptor-related receptor α (ERRα) is an orphan member of the nuclear receptor superfamily of transcription factors. ERRα is highly expressed in the prostate, especially in prostate stromal cells. However, little is known about the regulation and function of ERRα, which may contribute to the progression of prostatic diseases. We previously found that prostaglandin E2 (PGE2) up-regulated the expression of aromatase in prostate stromal cells. Here we show that PGE2 also up-regulates the expression of ERRα, which, as a transcription factor, further mediates the regulatory effects of PGE2 on the expression of aromatase. ERRα expression was up-regulated by PGE2 in prostate stromal cell line WPMY-1, which was mediated mainly through the protein kinase A signaling pathway by PGE2 receptor EP2. Suppression of ERRα activity by chlordane (an antagonist of ERRα) or small interfering RNA knockdown of ERRα blocked the increase of expression and promoter activity of aromatase induced by PGE2. Overexpression of ERRα significantly increased aromatase expression and promoter activity, which were further augmented by PGE2. Chromatin immunoprecipitation assay demonstrated that ERRα directly bound to the aromatase promoter in vivo, and PGE2 enhanced the recruitment of ERRα and promoted transcriptional regulatory effects on aromatase expression in WPMY-1. 17β-Estradiol concentration in WPMY-1 medium was up-regulated by ERRα expression, and that was further increased by PGE2. Our results provided evidence that ERRα contributed to local estrogen production by up-regulating aromatase expression in response to PGE2 and provided further insights into the potential role of ERRα in estrogen-related prostatic diseases. PMID:20351196

Functional distribution of Ca2+-coupled P2 purinergic receptors among adrenergic and noradrenergic bovine adrenal chromaffin cells.

PubMed

Tomé, Angelo R; Castro, Enrique; Santos, Rosa M; Rosário, Luís M

2007-06-14

Adrenal chromaffin cells mediate acute responses to stress through the release of epinephrine. Chromaffin cell function is regulated by several receptors, present both in adrenergic (AD) and noradrenergic (NA) cells. Extracellular ATP exerts excitatory and inhibitory actions on chromaffin cells via ionotropic (P2X) and metabotropic (P2Y) receptors. We have taken advantage of the actions of the purinergic agonists ATP and UTP on cytosolic free Ca2+ concentration ([Ca2+]i) to determine whether P2X and P2Y receptors might be asymmetrically distributed among AD and NA chromaffin cells. The [Ca2+]i and the [Na+]i were recorded from immunolabeled bovine chromaffin cells by single-cell fluorescence imaging. Among the ATP-sensitive cells ~40% did not yield [Ca2+]i responses to ATP in the absence of extracellular Ca2+ (Ca2+o), indicating that they expressed P2X receptors and did not express Ca2+- mobilizing P2Y receptors; the remainder expressed Ca2+-mobilizing P2Y receptors. Relative to AD-cells approximately twice as many NA-cells expressed P2X receptors while not expressing Ca2+- mobilizing P2Y receptors, as indicated by the proportion of cells lacking [Ca2+]i responses and exhibiting [Na+]i responses to ATP in the absence and presence of Ca2+o, respectively. The density of P2X receptors in NA-cells appeared to be 30-50% larger, as suggested by comparing the average size of the [Na+]i and [Ca2+]i responses to ATP. Conversely, approximately twice as many AD-cells expressed Ca2+-mobilizing P2Y receptors, and they appeared to exhibit a higher (~20%) receptor density. UTP raised the [Ca2+]i in a fraction of the cells and did not raise the [Na+]i in any of the cells tested, confirming its specificity as a P2Y agonist. The cell density of UTP-sensitive P2Y receptors did not appear to vary among AD- and NA-cells. Although neither of the major purinoceptor types can be ascribed to a particular cell phenotype, P2X and Ca2+-mobilizing P2Y receptors are preferentially located to noradrenergic and adrenergic chromaffin cells, respectively. ATP might, in addition to an UTP-sensitive P2Y receptor, activate an UTP-insensitive P2Y receptor subtype. A model for a short-loop feedback interaction is presented whereby locally released ATP acts upon P2Y receptors in adrenergic cells, inhibiting Ca2+ influx and contributing to terminate evoked epinephrine secretion.

Atypical nuclear localization of VIP receptors in glioma cell lines and patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barbarin, Alice; Séité, Paule; Godet, Julie

Highlights: • The VIP receptor VPAC1 contains a putative NLS signal. • VPAC1 is predominantly nuclear in GBM cell lines but not VPAC2. • Non-nuclear VPAC1/2 protein expression is correlated with glioma grade. • Nuclear VPAC1 is observed in 50% of stage IV glioma (GBM). - Abstract: An increasing number of G protein-coupled receptors, like receptors for vasoactive intestinal peptide (VIP), are found in cell nucleus. As VIP receptors are involved in the regulation of glioma cell proliferation and migration, we investigated the expression and the nuclear localization of the VIP receptors VPAC1 and VPAC2 in this cancer. First, bymore » applying Western blot and immunofluorescence detection in three human glioblastoma (GBM) cell lines, we observed a strong nuclear staining for the VPAC1 receptor and a weak nuclear VPAC2 receptor staining. Second, immunohistochemical staining of VPAC1 and VPAC2 on tissue microarrays (TMA) showed that the two receptors were expressed in normal brain and glioma tissues. Expression in the non-nuclear compartment of the two receptors significantly increased with the grade of the tumors. Analysis of nuclear staining revealed a significant increase of VPAC1 staining with glioma grade, with up to 50% of GBM displaying strong VPAC1 nuclear staining, whereas nuclear VPAC2 staining remained marginal. The increase in VPAC receptor expression with glioma grades and the enhanced nuclear localization of the VPAC1 receptors in GBM might be of importance for glioma progression.« less

Cloning and pharmacological characterization of the rabbit bradykinin B2 receptor.

PubMed

Bachvarov, D R; Saint-Jacques, E; Larrivée, J F; Levesque, L; Rioux, F; Drapeau, G; Marceau, F

1995-12-01

Degenerate primers, corresponding to consensus sequences of third and sixth transmembrane domains of G protein-coupled receptor superfamily, were used for the polymerase chain reaction amplification and consecutive characterization of G protein-coupled receptors present in cultured rabbit aortic smooth muscle cells. One of the isolated resulting fragments was highly homologous to the corresponding region of the bradykinin (BK) B2 receptor cloned in other species. The polymerase chain reaction fragment was used to screen a rabbit genomic library, which allowed the identification of an intronless 1101-nucleotide open reading frame which codes for a 367-amino acid receptor protein. The rabbit B2 receptor sequence is more than 80% identical to the ones determined in three other species and retain putative glycosylation, palmitoylation and phosphorylation sites. In the rabbit genomic sequence, an acceptor splice sequence was found 8 base pairs upstream of the start codon. Northern blot analysis showed a high expression of a major transcript (4.2 kilobases) in the rabbit kidney and duodenum, and a less abundant expression in other tissues. Southern blot experiments suggest that a single copy of this gene exists in the rabbit genome. The cloned rabbit B2 receptor expressed in COS-1 cells binds [3H]BK in a saturable manner (KD 2.1 nM) and this ligand competes with a series of kinin agonists and antagonist with a rank order consistent with the B2 receptor identity. The insurmountable character of the antagonism exerted by Hoe 140 against BK on the rabbit B2 receptor, previously shown in pharmacological experiments, was confirmed in binding experiments with the cloned receptor expressed in a controlled manner. By contrast, Hoe 140 competed with [3H]BK in a surmountable manner for the human B2 receptor expressed in COS-1 cells. The cloning of the rabbit B2 receptor will be useful notably for the study of the structural basis of antagonist binding and for studies on receptor regulation in a relatively large animal.

Prostaglandins and Their Receptors in Eosinophil Function and As Therapeutic Targets

PubMed Central

Peinhaupt, Miriam; Sturm, Eva M.; Heinemann, Akos

2017-01-01

Of the known prostanoid receptors, human eosinophils express the prostaglandin D2 (PGD2) receptors DP1 [also D-type prostanoid (DP)] and DP2 (also chemoattractant receptor homologous molecule, expressed on Th2 cells), the prostaglandin E2 receptors EP2 and EP4, and the prostacyclin (PGI2) receptor IP. Prostanoids can bind to either one or multiple receptors, characteristically have a short half-life in vivo, and are quickly degraded into metabolites with altered affinity and specificity for a given receptor subtype. Prostanoid receptors signal mainly through G proteins and naturally activate signal transduction pathways according to the G protein subtype that they preferentially interact with. This can lead to the activation of sometimes opposing signaling pathways. In addition, prostanoid signaling is often cell-type specific and also the combination of expressed receptors can influence the outcome of the prostanoid impulse. Accordingly, it is assumed that eosinophils and their (patho-)physiological functions are governed by a sensitive prostanoid signaling network. In this review, we specifically focus on the functions of PGD2, PGE2, and PGI2 and their receptors on eosinophils. We discuss their significance in allergic and non-allergic diseases and summarize potential targets for drug intervention. PMID:28770200

Neurotensin is an antagonist of the human neurotensin NT2 receptor expressed in Chinese hamster ovary cells.

PubMed

Vita, N; Oury-Donat, F; Chalon, P; Guillemot, M; Kaghad, M; Bachy, A; Thurneyssen, O; Garcia, S; Poinot-Chazel, C; Casellas, P; Keane, P; Le Fur, G; Maffrand, J P; Soubrie, P; Caput, D; Ferrara, P

1998-11-06

The human levocabastine-sensitive neurotensin NT2 receptor was cloned from a cortex cDNA library and stably expressed in Chinese hamster ovary (CHO) cells in order to study its binding and signalling characteristics. The receptor binds neurotensin as well as several other ligands already described for neurotensin NT1 receptor. It also binds levocabastine, a histamine H1 receptor antagonist that is not recognised by neurotensin NT1 receptor. Neurotensin binding to recombinant neurotensin NT2 receptor expressed in CHO cells does not elicit a biological response as determined by second messenger measurements. Levocabastine, and the peptides neuromedin N and xenin were also ineffective on neurotensin NT2 receptor activation. Experiments with the neurotensin NT1 receptor antagonists SR48692 and SR142948A, resulted in the unanticipated discovery that both molecules are potent agonists on neurotensin NT2 receptor. Both compounds, following binding to neurotensin NT2 receptor, enhance inositol phosphates (IP) formation with a subsequent [Ca2+]i mobilisation; induce arachidonic acid release; and stimulate mitogen-activated protein kinase (MAPK) activity. Interestingly, these activities are antagonised by neurotensin and levocabastine in a concentration-dependent manner. These activities suggest that the human neurotensin NT2 receptor may be of physiological importance and that a natural agonist for the receptor may exist.

Dopamine D2-like receptors (DRD2 and DRD4) in chickens: Tissue distribution, functional analysis, and their involvement in dopamine inhibition of pituitary prolactin expression.

PubMed

Lv, Can; Mo, Chunheng; Liu, Haikun; Wu, Chao; Li, Zhengyang; Li, Juan; Wang, Yajun

2018-04-20

Dopamine (DA) D2-like (and D1-like) receptors are suggested to mediate the dopamine actions in the anterior pituitary and/or CNS of birds. However, the information regarding the structure, functionality, and expression of avian D2-like receptors have not been fully characterized. In this study, we cloned two D2-like receptors (cDRD2, cDRD4) from chicken brain using RACE PCR. The cloned cDRD4 is a 378-amino acid receptor, which shows 57% amino acid (a.a.) identity with mouse DRD4. As in mammals, two cDRD2 isoforms, cDRD2L (long isoform, 437 a.a.) and cDRD2S (short isoform, 408 a.a.), which differ in their third intracellular loop, were identified in chickens. Using cell-based luciferase reporter assays or Western blot, we demonstrated that cDRD4, cDRD2L and cDRD2S could be activated by dopamine and quinpirole (a D2-like receptor agonist) dose-dependently, and their activation inhibits cAMP signaling pathway and stimulates MAPK/ERK signaling cascade, indicating that they are functional receptors capable of mediating dopamine actions. Quantitative real-time PCR revealed that cDRD2 and cDRD4 are widely expressed in chicken tissues with abundant expression noted in anterior pituitary, and their expressions are likely controlled by their promoters near exon 1, as demonstrated by dual-luciferase reporter assays in DF-1 cells. In accordance with cDRD2/cDRD4 expression in the pituitary, DA or quinpirole could partially inhibit vasoactive intestinal peptide-induced prolactin expression in cultured chick pituitary cells. Together, our data proves the functionality of DRD2 and DRD4 in birds and aids to uncover the conserved roles of DA/D2-like receptor system in vertebrates, such as its action on the pituitary. Copyright © 2018. Published by Elsevier B.V.

Corticosteroid receptor gene expression is related to sex and social behaviour in a social fish.

PubMed

O'Connor, Constance M; Rodela, Tammy M; Mileva, Viktoria R; Balshine, Sigal; Gilmour, Kathleen M

2013-03-01

Circulating corticosteroids have been related to social status in a variety of species. However, our understanding of corticosteroid receptor expression and its relationship with sociality is still in its infancy. Knowledge of variation in receptor expression is critical to understand the physiological relevance of differences in circulating corticosteroid concentrations. In this study, we examined corticosteroid receptor gene expression in relation to dominance rank, sex, and social behaviour in the highly social cichlid fish, Neolamprologus pulcher. We examined the relative gene expression of the three known teleost corticosteroid receptors: glucocorticoid receptor 1 (GR1), glucocorticoid receptor 2 (GR2), and the mineralocorticoid receptor (MR) in liver and brain tissue of dominant and subordinate N. pulcher males and females. Phylogenetic analysis revealed the N. pulcher gene originally described as GR2, clustered with other teleost GR1 genes, while the originally-described N. pulcher GR1 gene clustered with the GR2 genes of other teleosts. Therefore we propose a change in the original nomenclature of the N. pulcher GRs: GR1 (formerly GR2) and GR2 (formerly GR1) and adopt this new nomenclature throughout this manuscript. Liver MR transcript levels were higher in males than females, and positively related to submissive behaviour. Liver GR2 (formerly GR1) transcript levels were also higher in males than females. Collectively, the results demonstrate sex differences in corticosteroid receptor abundance, and suggest tissue- and receptor-specific roles for corticosteroid receptors in mediating aspects of social behaviour. Copyright © 2012. Published by Elsevier Inc.

Class I odorant receptors, TAS1R and TAS2R taste receptors, are markers for subpopulations of circulating leukocytes

PubMed Central

Malki, Agne; Fiedler, Julia; Fricke, Kristina; Ballweg, Ines; Pfaffl, Michael W.; Krautwurst, Dietmar

2015-01-01

Our cellular immune system has to cope constantly with foodborne substances that enter the bloodstream postprandially. Here, they may activate leukocytes via specific but yet mostly unknown receptors. Ectopic RNA expression out of gene families of chemosensory receptors, i.e., the ∼400 ORs, ∼25 TAS2R bitter-taste receptors, and the TAS1R umami- and sweet-taste receptor dimers by which we typically detect foodborne substances, has been reported in a variety of peripheral tissues unrelated to olfaction or taste. In the present study, we have now discovered, by gene-specific RT-PCR experiments, the mRNA expression of most of the Class I ORs (TAS1R) and TAS2R in 5 different types of blood leukocytes. Surprisingly, we did not detect Class II OR mRNA. By RT-qPCR, we show the mRNA expression of human chemosensory receptors and their cow orthologs in PMN, thus suggesting an evolutionary concept. By immunocytochemistry, we demonstrate that some olfactory and taste receptors are expressed, on average, in 40–60% of PMN and T or B cells and largely coexpress in the same subpopulation of PMN. The mRNA expression and the size of subpopulations expressing certain chemosensory receptors varied largely among individual blood samples, suggesting a regulated expression of olfactory and taste receptors in these cells. Moreover, we show mRNA expression of their downstream signaling molecules and demonstrate that PTX abolishes saccharin- or 2-PEA-induced PMN chemotactic migration, indicating a role for Gi-type proteins. In summary, our data suggest "chemosensory"-type subpopulations of circulating leukocytes. PMID:25624459

TRAIL Death Receptor-4 Expression Positively Correlates With the Tumor Grade in Breast Cancer Patients With Invasive Ductal Carcinoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanlioglu, Ahter D.; Department of Medical Biology and Genetics, Akdeniz University Faculty of Medicine, Antalya; Korcum, Aylin F.

2007-11-01

Purpose: Tumor necrosis factor-related apoptosis inducing ligand (TRAIL) selectively induces apoptosis in cancer cells but not in normal cells, and a number of clinical trials have recently been initiated to test the safety and antitumoral potential of TRAIL in cancer patients. Four different receptors have been identified to interact with TRAIL: two are death-inducing receptors (TRAIL-R1 [DR4] and TRAIL-R2 [DR5]), whereas the other two (TRAIL-R3 [DcR1] and TRAIL-R4 [DcR2]) do not induce death upon ligation and are believed to counteract TRAIL-induced cytotoxicity. Because high levels of DcR2 expression have recently been correlated with carcinogenesis in the prostate and lung, thismore » study investigated the importance of TRAIL and TRAIL receptor expression in breast cancer patients with invasive ductal carcinoma, taking various prognostic markers into consideration. Methods and Materials: Immunohistochemical analyses were performed on 90 breast cancer patients with invasive ductal carcinoma using TRAIL and TRAIL receptor-specific antibodies. Age, menopausal status, tumor size, lymph node status, tumor grade, lymphovascular invasion, perineural invasion, extracapsular tumor extension, presence of an extensive intraductal component, multicentricity, estrogen and progesterone receptor status, and CerbB2 expression levels were analyzed with respect to TRAIL/TRAIL receptor expression patterns. Results: The highest TRAIL receptor expressed in patients with invasive ductal carcinoma was DR4. Although progesterone receptor-positive patients exhibited lower DR5 expression, CerbB2-positive tissues displayed higher levels of both DR5 and TRAIL expressions. Conclusions: DR4 expression positively correlates with the tumor grade in breast cancer patients with invasive ductal carcinoma.« less

Angiotensin II AT2 receptor decreases AT1 receptor expression and function via nitric oxide/cGMP/Sp1 in renal proximal tubule cells from Wistar–Kyoto rats

PubMed Central

Yang, Jian; Chen, Caiyu; Ren, Hongmei; Han, Yu; He, Duofen; Zhou, Lin; Hopfer, Ulrich; Jose, Pedro A.; Zeng, Chunyu

2013-01-01

Background The renin–angiotensin (Ang) system controls blood pressure, in part, by regulating renal tubular sodium transport. In the kidney, activation of the angiotensin II type 1 (AT1) receptor increases renal sodium reabsorption, whereas the angiotensin II type 2 (AT2) receptor produces the opposite effect. We hypothesized that the AT2 receptor regulates AT1 receptor expression and function in the kidney. Methods and results In immortalized renal proximal tubule (RPT) cells from Wistar–Kyoto rats, CGP42112, an AT2 receptor agonist, decreased AT1 receptor mRNA and protein expression (P < 0.05), as assessed by reverse transcriptase-polymerase chain reaction and immunoblotting. The inhibitory effect of the AT2 receptor on AT1 receptor expression was blocked by the AT2 receptor antagonist, PD123319 (10−6 mol/l), the nitric oxide synthase inhibitor Nw-nitro-l-arginine methyl ester (10−4 mol/l), or the nitric oxide-dependent soluble guanylate cyclase inhibitor 1H-[1,2,4] oxadiazolo-[4,3-a] quinoxalin-1-one (10−5 mol/l), indicating that both nitric oxide and cyclic guanosine monophosphate (cGMP) were involved in the signaling pathway. Furthermore, CGP42112 decreased Sp1 serine phosphorylation and reduced the binding of Sp1 to AT1 receptor DNA. Stimulation with Ang II (10−11 mol/l per 30 min) enhanced Na+-K+-ATPase activity in RPT cells, which was prevented by pretreatment with CGP42112 (10−7 mol/l per 24 h) (P < 0.05). The above-mentioned results were confirmed in RPT cells from AT2 receptor knockout mice; AT1 receptor expression and Ang II-stimulated Na+-K+-ATPase activity were greater in these cells than in RPT cells from wild-type mice (P < 0.05). AT1/AT2 receptors co-localized and co-immunoprecipitated in RPT cells; short-term CGP42112 (10−7 mol/l per 30 min) treatment increased AT1/AT2 receptor co-immunoprecipitation (P < 0.05). Conclusions These results indicate that the renal AT2 receptor, via nitric oxide/cGMP/Sp1 pathway, regulates AT1 receptor expression and function, which may be important in the regulation of sodium excretion and blood pressure. PMID:22504846

Expression of ionotropic glutamate receptors, AMPA, kainite and NMDA, in the pigeon retina.

PubMed

Atoji, Yasuro

2015-07-01

Glutamate is an excitatory neurotransmitter in the vertebrate retina. A previous study found vesicular glutamate transporter 2 (vGluT2) mRNA in the pigeon retina, suggesting that bipolar and ganglion cells are glutamatergic. The present study examined the localization of ionotropic glutamate receptors to identify receptor cells in the pigeon retina using in situ hybridization histochemistry. Nine subunits of AMPA receptor (GluA1, GluA2, GluA3, and GluA4), kainate receptor (GluK1, GluK2, and GluK4), and NMDA receptor (GluN1 and GluN2A) were found to be expressed in the inner nuclear layer (INL) and ganglion cell layers. GluA1, GluA2, GluA3, and GluA4 were primarily expressed in the inner half of INL, and the signal intensity was strong for GluA2, GluA3, and GluA4. GluK1 was intensely expressed in the outer half of INL, whereas GluK2 and GluK4 were mainly localized in the inner half of INL. GluN1 and GluN2A were moderately expressed in the inner half of INL. Horizontal cells expressed GluA3 and GluA4, and ganglion cells expressed all subunits examined. These results suggest that the glutamatergic neurotransmission in the pigeon retina is similar to that in mammals. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sweet Taste Receptor Expressed in Pancreatic β-Cells Activates the Calcium and Cyclic AMP Signaling Systems and Stimulates Insulin Secretion

PubMed Central

Nakagawa, Yuko; Nagasawa, Masahiro; Yamada, Satoko; Hara, Akemi; Mogami, Hideo; Nikolaev, Viacheslav O.; Lohse, Martin J.; Shigemura, Noriatsu; Ninomiya, Yuzo; Kojima, Itaru

2009-01-01

Background Sweet taste receptor is expressed in the taste buds and enteroendocrine cells acting as a sugar sensor. We investigated the expression and function of the sweet taste receptor in MIN6 cells and mouse islets. Methodology/Principal Findings The expression of the sweet taste receptor was determined by RT–PCR and immunohistochemistry. Changes in cytoplasmic Ca2+ ([Ca2+]c) and cAMP ([cAMP]c) were monitored in MIN6 cells using fura-2 and Epac1-camps. Activation of protein kinase C was monitored by measuring translocation of MARCKS-GFP. Insulin was measured by radioimmunoassay. mRNA for T1R2, T1R3, and gustducin was expressed in MIN6 cells. In these cells, artificial sweeteners such as sucralose, succharin, and acesulfame-K increased insulin secretion and augmented secretion induced by glucose. Sucralose increased biphasic increase in [Ca2+]c. The second sustained phase was blocked by removal of extracellular calcium and addition of nifedipine. An inhibitor of inositol(1, 4, 5)-trisphophate receptor, 2-aminoethoxydiphenyl borate, blocked both phases of [Ca2+]c response. The effect of sucralose on [Ca2+]c was inhibited by gurmarin, an inhibitor of the sweet taste receptor, but not affected by a Gq inhibitor. Sucralose also induced sustained elevation of [cAMP]c, which was only partially inhibited by removal of extracellular calcium and nifedipine. Finally, mouse islets expressed T1R2 and T1R3, and artificial sweeteners stimulated insulin secretion. Conclusions Sweet taste receptor is expressed in β-cells, and activation of this receptor induces insulin secretion by Ca2+ and cAMP-dependent mechanisms. PMID:19352508

PGE2 maintains the tone of the guinea pig trachea through a balance between activation of contractile EP1 receptors and relaxant EP2 receptors

PubMed Central

Säfholm, J; Dahlén, S-E; Delin, I; Maxey, K; Stark, K; Cardell, L-O; Adner, M

2013-01-01

Background and Purpose The guinea pig trachea (GPT) is commonly used in airway pharmacology. The aim of this study was to define the expression and function of EP receptors for PGE2 in GPT as there has been ambiguity concerning their role. Experimental Approach Expression of mRNA for EP receptors and key enzymes in the PGE2 pathway were assessed by real-time PCR using species-specific primers. Functional studies of GPT were performed in tissue organ baths. Key Results Expression of mRNA for the four EP receptors was found in airway smooth muscle. PGE2 displayed a bell-shaped concentration–response curve, where the initial contraction was inhibited by the EP1 receptor antagonist ONO-8130 and the subsequent relaxation by the EP2 receptor antagonist PF-04418948. Neither EP3 (ONO-AE5-599) nor EP4 (ONO-AE3-208) selective receptor antagonists affected the response to PGE2. Expression of COX-2 was greater than COX-1 in GPT, and the spontaneous tone was most effectively abolished by selective COX-2 inhibitors. Furthermore, ONO-8130 and a specific PGE2 antibody eliminated the spontaneous tone, whereas the EP2 antagonist PF-04418948 increased it. Antagonists of other prostanoid receptors had no effect on basal tension. The relaxant EP2 response to PGE2 was maintained after long-term culture, whereas the contractile EP1 response showed homologous desensitization to PGE2, which was prevented by COX-inhibitors. Conclusions and Implications Endogenous PGE2, synthesized predominantly by COX-2, maintains the spontaneous tone of GPT by a balance between contractile EP1 receptors and relaxant EP2 receptors. The model may be used to study interactions between EP receptors. PMID:22934927

Novel receptor-targeted contrast agents for optical imaging of tumors

NASA Astrophysics Data System (ADS)

Becker, Andreas; Hessenius, Carsten; Bhargava, Sarah; Ebert, Bernd; Sukowski, Uwe; Rinneberg, Herbert H.; Wiedenmann, Bertram; Semmler, Wolfhard; Licha, Kai

2000-04-01

Many gastroenteropancreatic tumors express receptors for somatostatin (SST) and/or vasoactive intestinal peptide (VIP). These receptors can be used as molecular targets for the delivery of contrast agents for tumor diagnostics. We have synthesized conjugates consisting of a cyanine dye and an SST analogue or VIP for use as contrast agents in optical imaging. Receptor binding and internalization of these compounds were examined with optical methods in transfected RIN38 tumor cells expressing the SST2 receptor or a GFP- labeled VIP (VPAC1) receptor. Furthermore, biodistribution of the conjugates was examined by laser-induced fluorescence imaging in nude mice bearing SST2 or VPAC1 receptor- expressing tumors. After incubation of RIN38 SSTR2 cells in the presence of 100 nM indotricarbocyanine-SST analogue, cell-associated fluorescence increased, whereas no increase was observed when receptor-medicated endocytosis was inhibited. Indodicarbocyanine-VIP accumulated in RIN38 VPAC1 cells and co-localization with the GFP-labeled VPAC1 receptor was observed. After injection of indotricarbocyanine-SST analogue into tumor-bearing nude mice, SST2 receptor-positive tumors could be visualized for a time period from 10 min to at least 48 h. After application of indodicarbocyanine-VIP, a fluorescence signal in VIP1 receptor-expressing tumors was only detected during the first hour. We conclude that cyanine dye-labeled VIP and SST analogue are novel, targeted contrast agents for the optical imaging of tumors expressing the relevant receptor.

A Single Dose of LSD Does Not Alter Gene Expression of the Serotonin 2A Receptor Gene (HTR2A) or Early Growth Response Genes (EGR1-3) in Healthy Subjects

PubMed Central

Dolder, Patrick C.; Grünblatt, Edna; Müller, Felix; Borgwardt, Stefan J.; Liechti, Matthias E.

2017-01-01

Rationale: Renewed interest has been seen in the use of lysergic acid diethylamide (LSD) in psychiatric research and practice. The repeated use of LSD leads to tolerance that is believed to result from serotonin (5-HT) 5-HT2A receptor downregulation. In rats, daily LSD administration for 4 days decreased frontal cortex 5-HT2A receptor binding. Additionally, a single dose of LSD acutely increased expression of the early growth response genes EGR1 and EGR2 in rat and mouse brains through 5-HT2A receptor stimulation. No human data on the effects of LSD on gene expression has been reported. Therefore, we investigated the effects of single-dose LSD administration on the expression of the 5-HT2A receptor gene (HTR2A) and EGR1-3 genes. Methods: mRNA expression levels were analyzed in whole blood as a peripheral biomarker in 15 healthy subjects before and 1.5 and 24 h after the administration of LSD (100 μg) and placebo in a randomized, double-blind, placebo-controlled, cross-over study. Results: LSD did not alter the expression of the HTR2A or EGR1-3 genes 1.5 and 24 h after administration compared with placebo. Conclusion: No changes were observed in the gene expression of LSD’s primary target receptor gene or genes that are implicated in its downstream effects. Remaining unclear is whether chronic LSD administration alters gene expression in humans. PMID:28701958

ROLE OF NRF2 IN THE OXIDATIVE STRESS-DEPENDENT HYPERTENSION ASSOCIATED WITH THE DEPLETION OF DJ-1

PubMed Central

Cuevas, Santiago; Yang, Yu; Konkalmatt, Prasad; Asico, Laureano; Feranil, Jun; Jones, John; Villar, Van Anthony; Armando, Ines; Jose, Pedro A.

2015-01-01

Renal dopamine 2 receptor dysfunction is associated with oxidative stress and high blood pressure. We have reported that DJ-1, an oxidative stress response protein, is positively regulated by dopamine 2 receptor in the kidney. The transcription factor Nrf2 regulates the expression of several antioxidant genes. We tested the hypothesis that Nrf2 is involved in the renal DJ-1-mediated inhibition of reactive oxygen species production. We have reported that silencing dopamine 2 receptor in mouse renal proximal tubule cells decreases the expression of DJ-1. We now report that silencing DJ-1 or dopamine 2 receptor in mouse proximal tubule cells and mouse kidneys, decreases Nrf2 expression and activity and increases reactive oxygen species production; blood pressure is also increased in mice in which renal DJ-1 or dopamine 2 receptor is silenced. DJ-1−/− mice have decreased renal Nrf2 expression and activity, and increased nitro-tyrosine levels an dopamine 2 receptor d blood pressure. Silencing Nrf2 in mouse proximal tubule cells does not alter the expression of DJ-1 or dopamine 2 receptor, indicating that Nrf2 is downstream of dopamine 2 receptor and DJ-1. A Nrf2 inducer, bardoxolone, normalizes the systolic blood pressure and renal malondialdehyde levels in DJ-1−/− mice without affecting them in their wild-type littermates. Because Nrf2 ubiquitination is increased in DJ-1−/− mice, we conclude that the protective effect of DJ-1 on renal oxidative stress is mediated, in part, by preventing Nrf2 degradation. Moreover, renal dopamine 2 receptor and DJ-1 are necessary for normal Nrf2 activity to keep a normal redox balance and blood pressure. PMID:25895590

Identification of Human P2X1 Receptor-interacting Proteins Reveals a Role of the Cytoskeleton in Receptor Regulation*

PubMed Central

Lalo, Ulyana; Roberts, Jonathan A.; Evans, Richard J.

2011-01-01

P2X1 receptors are ATP-gated ion channels expressed by smooth muscle and blood cells. Carboxyl-terminally His-FLAG-tagged human P2X1 receptors were stably expressed in HEK293 cells and co-purified with cytoskeletal proteins including actin. Disruption of the actin cytoskeleton with cytochalasin D inhibited P2X1 receptor currents with no effect on the time course of the response or surface expression of the receptor. Stabilization of the cytoskeleton with jasplakinolide had no effect on P2X1 receptor currents but decreased receptor mobility. P2X2 receptor currents were unaffected by cytochalasin, and P2X1/2 receptor chimeras were used to identify the molecular basis of actin sensitivity. These studies showed that the intracellular amino terminus accounts for the inhibitory effects of cytoskeletal disruption similar to that shown for lipid raft/cholesterol sensitivity. Stabilization of the cytoskeleton with jasplakinolide abolished the inhibitory effects of cholesterol depletion on P2X1 receptor currents, suggesting that lipid rafts may regulate the receptor through stabilization of the cytoskeleton. These studies show that the cytoskeleton plays an important role in P2X1 receptor regulation. PMID:21757694

Human urothelial cell lines as potential models for studying cannabinoid and excitatory receptor interactions in the urinary bladder.

PubMed

Bakali, Evangelia; Elliott, Ruth A; Taylor, Anthony H; Lambert, David G; Willets, Jonathon M; Tincello, Douglas G

2014-06-01

To characterize human urothelial cell lines' cannabinoid receptor expression and evaluate their possible use for studying signalling interactions with purinergic and muscarinic receptor activation. PCR was used to detect cannabinoid (CB), muscarinic and purinergic receptor transcripts in HCV29 and UROtsa cells, whilst immunofluorescence evaluated protein expression and localization of cannabinoid receptors. The effect of CB1 agonist (ACEA) on carbachol- and ATP-induced changes in intracellular calcium ([Ca(2+)]i) levels was measured using fluorimetry. The ability of ACEA to reduce intracellular cAMP was investigated in HCV29 cells. CB1 and GPR55 receptor transcripts were detected in HCV29 and UROtsa cells, respectively. Immunofluorescence showed positive staining for CB1 in the HCV29 cells. Both cell lines expressed transcript levels for muscarinic receptors, but carbachol did not raise [Ca(2+)]i levels indicating a lack or low expression of G(q)-coupled muscarinic receptors. Transcripts for purinergic receptors were detected; ATP significantly increased [Ca(2+)]i in HCV29 and UROtsa cells by 395 ± 61 and 705 ± 100 nM (mean ± SEM, n = 6), respectively. ACEA did not alter ATP-induced [Ca(2+)]i or cAMP levels in HCV29 cells. Whilst HCV29 cells expressed CB1 and UROtsa cells expressed GPR55 receptors, these were not functionally coupled to the existing purinergic-driven increase in Ca2+ as such they do not represent a good model to study signalling interactions.

α2-containing GABAA receptors expressed in hippocampal region CA3 control fast network oscillations

PubMed Central

Heistek, Tim S; Ruiperez-Alonso, Marta; Timmerman, A Jaap; Brussaard, Arjen B; Mansvelder, Huibert D

2013-01-01

GABAA receptors are critically involved in hippocampal oscillations. GABAA receptor α1 and α2 subunits are differentially expressed throughout the hippocampal circuitry and thereby may have distinct contributions to oscillations. It is unknown which GABAA receptor α subunit controls hippocampal oscillations and where these receptors are expressed. To address these questions we used transgenic mice expressing GABAA receptor α1 and/or α2 subunits with point mutations (H101R) that render these receptors insensitive to allosteric modulation at the benzodiazepine binding site, and tested how increased or decreased function of α subunits affects hippocampal oscillations. Positive allosteric modulation by zolpidem prolonged decay kinetics of hippocampal GABAergic synaptic transmission and reduced the frequency of cholinergically induced oscillations. Allosteric modulation of GABAergic receptors in CA3 altered oscillation frequency in CA1, while modulation of GABA receptors in CA1 did not affect oscillations. In mice having a point mutation (H101R) at the GABAA receptor α2 subunit, zolpidem effects on cholinergically induced oscillations were strongly reduced compared to wild-type animals, while zolpidem modulation was still present in mice with the H101R mutation at the α1 subunit. Furthermore, genetic knockout of α2 subunits strongly reduced oscillations, whereas knockout of α1 subunits had no effect. Allosteric modulation of GABAergic receptors was strongly reduced in unitary connections between fast spiking interneurons and pyramidal neurons in CA3 of α2H101R mice, but not of α1H101R mice, suggesting that fast spiking interneuron to pyramidal neuron synapses in CA3 contain α2 subunits. These findings suggest that α2-containing GABAA receptors expressed in the CA3 region provide the inhibition that controls hippocampal rhythm during cholinergically induced oscillations. PMID:23109109

Serotonin 5-HT2C receptor-independent expression of hypothalamic NOR1, a novel modulator of food intake and energy balance, in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nonogaki, Katsunori, E-mail: knonogaki-tky@umin.ac.jp; Department of Lifestyle Medicine, Biomedical Engineering Center, Tohoku University; Kaji, Takao

2009-08-21

NOR1, Nur77 and Nurr1 are orphan nuclear receptors and members of the NR4A subfamily. Here, we report that the expression of hypothalamic NOR1 was remarkably decreased in mildly obese {beta}-endorphin-deficient mice and obese db/db mice with the leptin receptor mutation, compared with age-matched wild-type mice, whereas there were no genotypic differences in the expression of hypothalamic Nur77 or Nurr1 in these animals. The injection of NOR1 siRNA oligonucleotide into the third cerebral ventricle significantly suppressed food intake and body weight in mice. On the other hand, the decreases in hypothalamic NOR1 expression were not found in non-obese 5-HT2C receptor-deficient mice.more » Moreover, systemic administration of m-chlorophenylpiperazine (mCPP), a 5-HT2C/1B receptor agonist, had no effect on hypothalamic NOR1 expression, while suppressing food intake in {beta}-endorphin-deficient mice. These findings suggest that 5-HT2C receptor-independent proopiomelanocortin-derived peptides regulate the expression of hypothalamic NOR1, which is a novel modulator of feeding behavior and energy balance.« less

Cocaine Modulates the Expression of Opioid Receptors and miR-let-7d in Zebrafish Embryos

PubMed Central

López-Bellido, Roger; Barreto-Valer, Katherine; Sánchez-Simón, Fátima Macho; Rodríguez, Raquel E.

2012-01-01

Prenatal exposure to cocaine, in mammals, has been shown to interfere with the expression of opioid receptors, which can have repercussions in its activity. Likewise, microRNAs, such as let-7, have been shown to regulate the expression of opioid receptors and hence their functions in mammals and in vitro experiments. In light of this, using the zebrafish embryos as a model our aim here was to evaluate the actions of cocaine in the expression of opioid receptors and let-7d miRNA during embryogenesis. In order to determine the effects produced by cocaine on the opioid receptors (zfmor, zfdor1 and zfdor2) and let-7d miRNA (dre-let-7d) and its precursors (dre-let-7d-1 and dre-let-7d-2), embryos were exposed to 1.5 µM cocaine hydrochloride (HCl). Our results revealed that cocaine upregulated dre-let-7d and its precursors, and also increased the expression of zfmor, zfdor1 and zfdor2 during early developmental stages and decreased them in late embryonic stages. The changes observed in the expression of opioid receptors might occur through dre-let-7d, since DNA sequences and the morpholinos of opioid receptors microinjections altered the expression of dre-let-7d and its precursors. Likewise, opioid receptors and dre-let-7d showed similar distributions in the central nervous system (CNS) and at the periphery, pointing to a possible interrelationship between them. In conclusion, the silencing and overexpression of opioid receptors altered the expression of dre-let-7d, which points to the notion that cocaine via dre-let-7 can modulate the expression of opioid receptors. Our study provides new insights into the actions of cocaine during zebrafish embryogenesis, indicating a role of miRNAs, let-7d, in development and its relationship with gene expression of opioid receptors, related to pain and addiction process. PMID:23226419

Dramatically reduced surface expression of NK cell receptor KIR2DS3 is attributed to multiple residues throughout the molecule.

PubMed

VandenBussche, C J; Mulrooney, T J; Frazier, W R; Dakshanamurthy, S; Hurley, C K

2009-03-01

Using flow cytometry, fluorescent microscopy and examination of receptor glycosylation status, we demonstrate that an entire killer cell immunoglobulin-like receptor (KIR) locus (KIR2DS3)--assumed earlier to be surface expressed--appears to have little appreciable surface expression in transfected cells. This phenotype was noted for receptors encoded by three allelic variants including the common KIR2DS3*001 allele. Comparing the surface expression of KIR2DS3 with that of the better-studied KIR2DS1 molecule in two different cell lines, mutational analysis identified multiple polymorphic amino-acid residues that significantly alter the proportion of molecules present on the cell surface. A simultaneous substitution of five residues localized to the leader peptide (residues -18 and -7), second domain (residues 123 and 150) and transmembrane region (residue 234) was required to restore KIR2DS3 to the expression level of KIR2DS1. Corresponding simultaneous substitutions of KIR2DS1 to the KIR2DS3 residues resulted in a dramatically decreased surface expression. Molecular modeling was used to predict how these substitutions contribute to this phenotype. Alterations in receptor surface expression are likely to affect the balance of immune cell signaling impacting the characteristics of the response to pathogens or malignancy.

UDP-Glucuronosyltransferase Expression in Mouse Liver Is Increased in Obesity- and Fasting-Induced Steatosis

PubMed Central

Xu, Jialin; Kulkarni, Supriya R.; Li, Liya

2012-01-01

UDP-glucuronosyltransferases (Ugt) catalyze phase II conjugation reactions with glucuronic acid, which enhances chemical polarity and the elimination from the body. Few studies have addressed whether Ugt expression and activity are affected by liver disease, such as steatosis. The purpose of this study was to determine whether steatosis induced by obesity or fasting could affect liver Ugt mRNA expression and activity. Male C57BL/6J and Lepob/ob (ob/ob) mice were fed ad libitum or food was withheld for 24 h. In steatotic livers of ob/ob mice, Ugt1a1, -1a6, -1a9, -2a3, -3a1, and -3a2 mRNA expression increased. Fasting, which also induced steatosis, increased hepatic Ugt1a1, -1a6, -1a7, -1a9, -2b1, -2b5, -2a3, -3a1, and -3a2 mRNA expression in mouse liver. Likewise, acetaminophen glucuronidation increased by 47% in hepatic microsomes from ob/ob mice compared with that in C57BL/6J mice, but not after fasting. In both steatosis models, Ugt induction was accompanied by increased aryl hydrocarbon receptor, constitutive androstane receptor (CAR), peroxisome proliferator-activated receptor (PPAR)-α, pregnane X receptor, nuclear factor (erythroid-derived 2)-like 2 (Nrf2), and peroxisome proliferator-activated receptor-γ coactivator-1α mRNA expression. In addition, fasting increased CAR, PPAR, and Nrf2 binding activity. The work points to hepatic triglyceride concentrations corresponding with nuclear receptor and Ugt expression. The findings indicate that steatosis significantly alters hepatic Ugt expression and activity, which could have a significant impact on determining circulating hormone levels, drug efficacy, and environmental chemical clearance. PMID:22031624

UDP-glucuronosyltransferase expression in mouse liver is increased in obesity- and fasting-induced steatosis.

PubMed

Xu, Jialin; Kulkarni, Supriya R; Li, Liya; Slitt, Angela L

2012-02-01

UDP-glucuronosyltransferases (Ugt) catalyze phase II conjugation reactions with glucuronic acid, which enhances chemical polarity and the elimination from the body. Few studies have addressed whether Ugt expression and activity are affected by liver disease, such as steatosis. The purpose of this study was to determine whether steatosis induced by obesity or fasting could affect liver Ugt mRNA expression and activity. Male C57BL/6J and Lep(ob/ob) (ob/ob) mice were fed ad libitum or food was withheld for 24 h. In steatotic livers of ob/ob mice, Ugt1a1, -1a6, -1a9, -2a3, -3a1, and -3a2 mRNA expression increased. Fasting, which also induced steatosis, increased hepatic Ugt1a1, -1a6, -1a7, -1a9, -2b1, -2b5, -2a3, -3a1, and -3a2 mRNA expression in mouse liver. Likewise, acetaminophen glucuronidation increased by 47% in hepatic microsomes from ob/ob mice compared with that in C57BL/6J mice, but not after fasting. In both steatosis models, Ugt induction was accompanied by increased aryl hydrocarbon receptor, constitutive androstane receptor (CAR), peroxisome proliferator-activated receptor (PPAR)-α, pregnane X receptor, nuclear factor (erythroid-derived 2)-like 2 (Nrf2), and peroxisome proliferator-activated receptor-γ coactivator-1α mRNA expression. In addition, fasting increased CAR, PPAR, and Nrf2 binding activity. The work points to hepatic triglyceride concentrations corresponding with nuclear receptor and Ugt expression. The findings indicate that steatosis significantly alters hepatic Ugt expression and activity, which could have a significant impact on determining circulating hormone levels, drug efficacy, and environmental chemical clearance.

Regulation of dopaminergic neuron firing by heterogeneous dopamine autoreceptors in the substantia nigra pars compacta.

PubMed

Jang, Jin Young; Jang, Miae; Kim, Shin Hye; Um, Ki Bum; Kang, Yun Kyung; Kim, Hyun Jin; Chung, Sungkwon; Park, Myoung Kyu

2011-03-01

Dopamine (DA) receptors generate many cellular signals and play various roles in locomotion, motivation, hormone production, and drug abuse. According to the location and expression types of the receptors in the brain, DA signals act in either stimulatory or inhibitory manners. Although DA autoreceptors in the substantia nigra pars compacta are known to regulate firing activity, the exact expression patterns and roles of DA autoreceptor types on the firing activity are highly debated. Therefore, we performed individual correlation studies between firing activity and receptor expression patterns using acutely isolated rat substantia nigra pars compacta DA neurons. When we performed single-cell RT-PCR experiments, D(1), D(2)S, D(2)L, D(3), and D(5) receptor mRNA were heterogeneously expressed in the order of D(2)L > D(2)S > D(3) > D(5) > D(1). Stimulation of D(2) receptors with quinpirole suppressed spontaneous firing similarly among all neurons expressing mRNA solely for D(2)S, D(2)L, or D(3) receptors. However, quinpirole most strongly suppressed spontaneous firing in the neurons expressing mRNA for both D(2) and D(3) receptors. These data suggest that D(2) S, D(2)L, and D(3) receptors are able to equally suppress firing activity, but that D(2) and D(3) receptors synergistically suppress firing. This diversity in DA autoreceptors could explain the various actions of DA in the brain. © 2011 The Authors. Journal of Neurochemistry © 2011 International Society for Neurochemistry.

Short-Term Hyperprolactinemia Reduces the Expression of Purinergic P2X7 Receptors during Allergic Inflammatory Response of the Lungs.

PubMed

Ochoa-Amaya, Julieta E; Queiroz-Hazarbassanov, Nicolle; Namazu, Lilian B; Calefi, Atilio S; Tobaruela, Carla N; Margatho, Rafael; Palermo-Neto, João; Ligeiro de Oliveira, Ana P; Felicio, Luciano F

2018-06-06

We have previously shown that domperidone-induced short-term hyperprolactinemia reduces the lung's allergic inflammatory response in an ovalbumin antigenic challenge model. Since purinergic receptor P2X7R activity leads to proinflammatory cytokine release and is possibly related to the pathogenesis of allergic respiratory conditions, the present study was designed to investigate a possible involvement of purinergic and prolactin receptors in this phenomenon. To induce hyperprolactinemia, domperidone was injected intraperitoneally in rats at a dose of 5.1 mg × kg-1 per day for 5 days. P2X7 expression was evaluated by lung immunohistochemistry while prolactin receptor expression in bronchoalveolar lavage leukocytes was analyzed through flow cytometry. Previous reports demonstrated that rats subjected to short-term hyperprolactinemia exhibited a decrease in leukocyte counts in bronchoalveolar lavage, especially granulocytes. Here, it is revealed that hyperprolactinemia promotes an increased expression of prolactin receptors in granulocytes. Also, increased expression of purinergic P2X7R observed in allergic animals was significantly reduced by hyperprolactinemia. Both purinergic and prolactin receptor expression changes occur during the anti-asthmatic effect of hyperprolactinemia. © 2018 S. Karger AG, Basel.

Short-term sleep deprivation impairs spatial working memory and modulates expression levels of ionotropic glutamate receptor subunits in hippocampus.

PubMed

Xie, Meilan; Yan, Jie; He, Chao; Yang, Li; Tan, Gang; Li, Chao; Hu, Zhian; Wang, Jiali

2015-06-01

Hippocampus-dependent learning memory is sensitive to sleep deprivation (SD). Although the ionotropic glutamate receptors play a vital role in synaptic plasticity and learning and memory, however, whether the expression of these receptor subunits is modulated by sleep loss remains unclear. In the present study, western blotting was performed by probing with specific antibodies against the ionotropic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunits GluA1, GluA2, GluA3, and against the N-methyl-d-aspartate (NMDA) glutamate receptor subunits GluN1, GluN2A, GluN2B. In hippocampus, down regulation of surface GluA1 and GluN2A surface expression were observed in both SD groups. However, surface expression level of GluA2, GluA3, GluN1 and GluN2B was significantly up-regulated in 8h-SD rats when compared to the 4h-SD rats. In parallel with the complex changes in AMPA and NMDA receptor subunit expressions, we found the 8h-SD impaired rat spatial working memory in 30-s-delay T-maze task, whereas no impairment of spatial learning was observed in 4h-SD rats. These results indicate that sleep loss alters the relative expression levels of the AMPA and NMDA receptors, thus affects the synaptic strength and capacity for plasticity and partially contributes to spatial memory impairment. Copyright © 2015. Published by Elsevier B.V.

Functional expression of Squalus acanthias melanocortin-5 receptor in CHO cells: ligand selectivity and interaction with MRAP.

PubMed

Reinick, Christina L; Liang, Liang; Angleson, Josepha K; Dores, Robert M

2012-04-05

The melanocortin-5 receptor (MC(5)) of the dogfish Squalus acanthias (SacMC(5) receptor) can be functionally expressed in CHO cells in the absence of the co-expression of an exogenous MRAP cDNA. Both human ACTH(1-24) and dogfish ACTH(1-25) were much better stimulators of the SacMC(5) receptor than any of the mammalian or dogfish MSH ligands that were tested. The order of ligand selectivity for the dogfish melanocortins was ACTH(1-25)>αMSH>γ-MSH=δ-MSH>β-MSH. Unlike mammalian MC(5) receptors, the functional expression of the SacMC(5) receptor was not negatively impacted when the receptor was co-expressed with a cartilaginous fish (Callorhinchus milii) MRAP2 cDNA. However, co-expression with either mouse mMRAP1 or zebrafish zfMRAP1 increased the sensitivity of SacMC(5) receptor for hACTH(1-24) by at least one order of magnitude. Hence, SacMC(5) receptor has the potential to interact with MRAP1 orthologs and in this regard behaved more like a melanocortin MC(2) receptor ortholog than a melanocortin MC(5) receptor ortholog. These observations are discussed in light of the evolution of the melanocortin receptor gene family in cartilaginous fish, and the physiological implications of these observations are considered. Copyright © 2012 Elsevier B.V. All rights reserved.

The effect of mifepristone on the peripheral blood natural killer cell's cytotoxicity and expression of CD94/NKG2A and NKG2D during the implantation phase.

PubMed

Chen, Xiu-Ying; Zhuang, Ya-Ling; Li, Li; Zhang, Wu-Wen; Huang, Li-Li

2010-05-15

To investigate the effect of mifepristone on peripheral blood natural killer cell's (pbNK) cytotoxicity and the expression of the inhibitory receptor CD94/NKG2A and the activated receptor NKG2D on pbNK cells. In vitro study. University hospital and research laboratory. Twenty healthy nonpregnant women. Detected the cytolytic activity of pbNK to K562 target cells; measured the expression of CD94/NKG2A and NKG2D on pbNK. Cytotoxicity of pbNK was detected by Methyl thiazolyl tetrazolium. The expression of CD94/NKG2A and NKG2D receptor on pbNK cells were detected by flow cytometry. The NK cell cytotoxicity and the expression of inhibitory receptor CD94/NKG2A during the proliferative phase (81.71 +/- 11.5, 86.6 +/- 9.0) was significantly higher than the secretory phase (60.16 +/- 19.2, 60.15 +/- 31.0). The NK cells cytotoxicity, after being treated with mifepristone and the expression of inhibitory receptor CD94/NKG2A on pbNK cells treated with 200 nmol/L mifepristone, were significantly increased. Mifepristone had no effect on the expression of activating receptor NKG2D. These data suggest that Mifepristone maybe exert its anti-implantation function by increasing NK cytotoxicity. The increasing NK cytotoxicity of mifepristone is not related to CD94/NKG2A and NKG2D. In the secretory phase down-regulated CD94/NKG2A, NKG2D, and NK cytotoxicity may benefit with embryo implantation. Crown Copyright 2010. Published by Elsevier Inc. All rights reserved.

BMP type II receptors have redundant roles in the regulation of hepatic hepcidin gene expression and iron metabolism.

PubMed

Mayeur, Claire; Leyton, Patricio A; Kolodziej, Starsha A; Yu, Binglan; Bloch, Kenneth D

2014-09-25

Expression of hepcidin, the hepatic hormone controlling iron homeostasis, is regulated by bone morphogenetic protein (BMP) signaling. We sought to identify which BMP type II receptor expressed in hepatocytes, ActR2a or BMPR2, is responsible for regulating hepcidin gene expression. We studied Bmpr2 heterozygous mice (Bmpr2(+/-)), mice with hepatocyte-specific deficiency of BMPR2, mice with global deficiency of ActR2a, and mice in which hepatocytes lacked both BMPR2 and ActR2a. Hepatic hepcidin messenger RNA (mRNA) levels, serum hepcidin and iron levels, and tissue iron levels did not differ in wild-type mice, Bmpr2(+/-) mice, and mice in which either BMPR2 or ActR2a was deficient. Deficiency of both BMP type II receptors markedly reduced hepatic hepcidin gene expression and serum hepcidin levels leading to severe iron overload. Iron injection increased hepatic hepcidin mRNA levels in mice deficient in either BMPR2 or ActR2a, but not in mice deficient in both BMP type II receptors. In addition, in mouse and human primary hepatocytes, deficiency of both BMPR2 and ActR2a profoundly decreased basal and BMP6-induced hepcidin gene expression. These results suggest that BMP type II receptors, BMPR2 and ActR2a, have redundant roles in the regulation of hepatic hepcidin gene expression and iron metabolism. © 2014 by The American Society of Hematology.

Type I Interferon Receptor Expression in Human Pancreatic and Periampullary Cancer Tissue.

PubMed

Booy, Stephanie; Hofland, Leo J; Waaijers, A Marlijn; Croze, Ed; van Koetsveld, Peter M; de Vogel, Lisette; Biermann, Katharina; van Eijck, Casper H J

2015-01-01

Interferons (IFNs) have several anticancer mechanisms. A number of clinical trials have been conducted regarding adjuvant IFN-α therapy in pancreatic cancer. Type I IFNs exert their effect via the type I IFN receptor (IFNAR-1, IFNAR-2c). The aims of the present study were to determine the type I IFN receptor expression in pancreatic and periampullary cancer tissues and to study its relation with clinicopathological factors. Receptor expression was determined by immunohistochemistry in paraffin-embedded cancer tissue of 47 pancreatic and 54 periampullary cancer patients. The results demonstrated that 91.5% of the pancreatic tumors and 88.9% of the periampullary tumors showed expression of IFNAR-1, of which 23.4% and 13.0% were strongly positive, respectively. Regarding IFNAR-2c expression, 68.1% of the pancreatic tumors and 68.5% of the periampullary tumors were positive, of which 4.3% of the pancreatic tumors and none of the periampullary tumors had a strong expression. No statistically significant associations were found between type I IFN receptor expression and clinicopathological factors or survival. Type I IFN receptors are expressed in pancreatic and periampullary cancer tissues although with great intertumoral and intratumoral variability. A small proportion of both tumors showed a strong expression of the IFNAR-1; only a very small percentage of the pancreatic tumors showed strong expression of the IFNAR-2c.

Signaling Pathways of Purinergic Receptors and Their Interactions with Cholinergic and Adrenergic Pathways in the Lacrimal Gland

PubMed Central

Hodges, Robin R.

2016-01-01

Abstract Purpose: Purinergic receptors play a key role in the function of the lacrimal gland (LG) as P1 purinergic receptors A1, A2A, and A2B, P2X1–7 receptors, and many of the P2Y receptors are expressed. Methods: This review examines the current knowledge of purinergic receptors in the LG as well as the signaling pathways activated by these receptors. Results: These receptors are expressed on the acinar, ductal, and myoepithelial cells. Considerable crosstalk exists between the pathways activated by P2X7 receptors with those activated by M3 muscarinic or α1D adrenergic receptors. The mechanism of the crosstalk between P2X7 and M3 muscarinic receptors differs from that of the crosstalk between P2X7 and α1D adrenergic receptors. Conclusions: Understanding purinergic receptors and how they modulate protein secretion could play a key role in normal and pathological responses of the LG. PMID:27463365

Purinergic receptor ligands stimulate pro-opiomelanocortin gene expression in AtT-20 pituitary corticotroph cells.

PubMed

Zhao, L-F; Iwasaki, Y; Oki, Y; Tsugita, M; Taguchi, T; Nishiyama, M; Takao, T; Kambayashi, M; Hashimoto, K

2006-04-01

Although recent studies have suggested that purinergic receptors are expressed in the anterior pituitary gland, their involvement in the regulation of pituitary hormone gene expression is not completely understood. In the present study, we examined the expression of purinergic receptors and the effects of purinergic receptor ligands on pro-opiomelanocortin (POMC) gene expression, in AtT20 mouse corticotroph cells. We identified the expression of most of the purinergic receptor subtypes (A1, A2, P2X1, 3-7, P2Y1, 2, 4) mRNAs, analysed by the reverse transcriptase-polymerase chain reaction. We also found that adenosine and ATP, two representative and endogenous agonists of A1-3 and P2X/P2Y receptors, respectively, stimulated the 5'-promoter activity of the POMC gene in a dose- and time-related manner. When these ligands were simultaneously used with corticotrophin-releasing hormone (CRH), effects that were more than additive were observed, suggesting an enhancing role of these compounds in CRH-mediated adrenocorticotrophic hormone (ACTH) synthesis. These ligands also stimulated the expression of transcription factors involved in the regulation of the POMC gene, but did not enhance ACTH secretion. Finally, the positive effect of adenosine as well as CRH was completely inhibited by the protein kinase A inhibitor H89, whereas that of ATP was not influenced, indicating that different intracellular signalling pathways mediate these effects. Altogether, our results suggest a stimulatory role for these purinergic receptor ligands in the regulation of POMC gene expression in corticotroph cells. Because adenosine and ATP are known to be produced within the pituitary gland, it is possible they may be acting in an autocrine/paracrine fashion.

Platelet dysfunction associated with the novel Trp29Cys thromboxane A₂ receptor variant.

PubMed

Mumford, A D; Nisar, S; Darnige, L; Jones, M L; Bachelot-Loza, C; Gandrille, S; Zinzindohoue, F; Fischer, A-M; Mundell, S J; Gaussem, P

2013-03-01

Genetic variations that affect the structure of the thromboxane A2 receptor (TP receptor) provide insights into the function of this key platelet and vascular receptor, but are very rare in unselected populations. To determine the functional consequences of the TP receptor Trp29Cys (W29C) substitution. We performed a detailed phenotypic analysis of an index case (P1) with reduced platelet aggregation and secretion responses to TP receptor pathway activators, and a heterozygous TP receptor W29C substitution. An analysis of the variant W29C TP receptor expressed in heterologous cells was performed. Total TP receptor expression in platelets from P1 was similar to that of controls, but there was reduced maximum binding and reduced affinity of binding to the TP receptor antagonist [(3) H]SQ29548. HEK293 cells transfected with W29C TP receptor cDNA showed similar total TP receptor expression to wild-type (WT) controls. However, the TP receptor agonist U46619 was less potent at inducing rises in cytosolic free Ca(2+) in HEK293 cells expressing the W29C TP receptor than in WT controls, indicating reduced receptor function. Immunofluorescence microscopy and cell surface ELISA showed intracellular retention and reduced cell surface expression of the W29C TP receptor in HEK293 cells. Consistent with the platelet phenotype, both maximum binding and the affinity of binding of [(3) H]SQ29548 to the W29C TP receptor were reduced compared to WT controls. These findings extend the phenotypic description of the very rare disorder TP receptor deficiency, and show that the W29C substitution reduces TP receptor function by reducing surface receptor expression and by disrupting ligand binding. © 2012 International Society on Thrombosis and Haemostasis.

Effects of chronic scopolamine administration on spatial working memory and hippocampal receptors related to learning.

PubMed

Doguc, Duygu K; Delibas, Namik; Vural, Huseyin; Altuntas, Irfan; Sutcu, Recep; Sonmez, Yonca

2012-12-01

Scopolamine has been used in neuropsychopharmacology as a standard drug that leads to symptoms mimicking cognitive deficits seen during the aging process in healthy humans and animals. Scopolamine is known to be a nonselective muscarinic receptor blocker, but its chronic effect on the expression of certain hippocampal receptors is not clear. The aim of the present study was to determine the effect of chronic scopolamine administration on hippocampal receptor expression and spatial working memory in two different learning tasks, the water maze and the eight-arm radial maze. Male rats (8-12 months) were trained in both tasks. Subsequently, different groups received physiological saline or 0.1, 0.8, or 2 mg/kg scopolamine hydrobromide, respectively, for 15 days. After drug administration, the rats were retested for both tasks, and hippocampal expressions of NR2A, NR2B, nAChRα7, and mAChRM1 receptors were assessed by western blotting analysis. In both tasks, the spatial working memory was decreased dose dependently in all groups compared with the control group. In terms of receptor expressions, 0.8 and 2 mg/kg scopolamine administration significantly decreased NR2A protein expression, which corroborates suggestions of an interaction between cholinergic and glutamatergic receptors in the hippocampus.

Pharmacological characterization of recombinant human and rat P2X receptor subtypes.

PubMed

Bianchi, B R; Lynch, K J; Touma, E; Niforatos, W; Burgard, E C; Alexander, K M; Park, H S; Yu, H; Metzger, R; Kowaluk, E; Jarvis, M F; van Biesen, T

1999-07-02

ATP functions as a fast neurotransmitter through the specific activation of a family of ligand-gated ion channels termed P2X receptors. In this report, six distinct recombinant P2X receptor subtypes were pharmacologically characterized in a heterologous expression system devoid of endogenous P2 receptor activity. cDNAs encoding four human P2X receptor subtypes (hP2X1, hP2X3, hP2X4, and hP2X7), and two rat P2X receptor subtypes (rP2X2 and rP2X3), were stably expressed in 1321N1 human astrocytoma cells. Furthermore, the rP2X2 and rP2X3 receptor subtypes were co-expressed in these same cells to form heteromultimeric receptors. Pharmacological profiles were determined for each receptor subtype, based on the activity of putative P2 ligands to stimulate Ca2+ influx. The observed potency and kinetics of each response was receptor subtype-specific and correlated with their respective electrophysiological properties. Each receptor subtype exhibited a distinct pharmacological profile, based on its respective sensitivity to nucleotide analogs, diadenosine polyphosphates and putative P2 receptor antagonists. Alphabeta-methylene ATP (alphabeta-meATP), a putative P2X receptor-selective agonist, was found to exhibit potent agonist activity only at the hP2X1, hP2X3 and rP2X3 receptor subtypes. Benzoylbenzoic ATP (BzATP, 2' and 3' mixed isomers), which has been reported to act as a P2X7 receptor-selective agonist, was least active at the rat and human P2X7 receptors, but was a potent (nM) agonist at hP2X1, rP2X3 and hP2X3 receptors. These data comprise a systematic examination of the functional pharmacology of P2X receptor activation.

Prolactin receptor, growth hormone receptor, and putative somatolactin receptor in Mozambique tilapia: tissue specific expression and differential regulation by salinity and fasting.

PubMed

Pierce, A L; Fox, B K; Davis, L K; Visitacion, N; Kitahashi, T; Hirano, T; Grau, E G

2007-01-01

In fish, pituitary growth hormone family peptide hormones (growth hormone, GH; prolactin, PRL; somatolactin, SL) regulate essential physiological functions including osmoregulation, growth, and metabolism. Teleost GH family hormones have both differential and overlapping effects, which are mediated by plasma membrane receptors. A PRL receptor (PRLR) and two putative GH receptors (GHR1 and GHR2) have been identified in several teleost species. Recent phylogenetic analyses and binding studies suggest that GHR1 is a receptor for SL. However, no studies have compared the tissue distribution and physiological regulation of all three receptors. We sequenced GHR2 from the liver of the Mozambique tilapia (Oreochromis mossambicus), developed quantitative real-time PCR assays for the three receptors, and assessed their tissue distribution and regulation by salinity and fasting. PRLR was highly expressed in the gill, kidney, and intestine, consistent with the osmoregulatory functions of PRL. PRLR expression was very low in the liver. GHR2 was most highly expressed in the muscle, followed by heart, testis, and liver, consistent with this being a GH receptor with functions in growth and metabolism. GHR1 was most highly expressed in fat, liver, and muscle, suggesting a metabolic function. GHR1 expression was also high in skin, consistent with a function of SL in chromatophore regulation. These findings support the hypothesis that GHR1 is a receptor for SL. In a comparison of freshwater (FW)- and seawater (SW)-adapted tilapia, plasma PRL was strongly elevated in FW, whereas plasma GH was slightly elevated in SW. PRLR expression was reduced in the gill in SW, consistent with PRL's function in freshwater adaptation. GHR2 was elevated in the kidney in FW, and correlated negatively with plasma GH, whereas GHR1 was elevated in the gill in SW. Plasma IGF-I, but not GH, was reduced by 4 weeks of fasting. Transcript levels of GHR1 and GHR2 were elevated by fasting in the muscle. However, liver levels of GHR1 and GHR2 transcripts, and liver and muscle levels of IGF-I transcripts were unaffected by fasting. These results clearly indicate tissue specific expression and differential physiological regulation of GH family receptors in the tilapia.

Characteristics of concatemeric GABAA receptors containing α4/δ subunits expressed in Xenopus oocytes

PubMed Central

Shu, Hong-Jin; Bracamontes, John; Taylor, Amanda; Wu, Kyle; Eaton, Megan M; Akk, Gustav; Manion, Brad; Evers, Alex S; Krishnan, Kathiresan; Covey, Douglas F; Zorumski, Charles F; Steinbach, Joe Henry; Mennerick, Steven

2012-01-01

BACKGROUND AND PURPOSE GABAA receptors mediate both synaptic and extrasynaptic actions of GABA. In several neuronal populations, α4 and δ subunits are key components of extrasynaptic GABAA receptors that strongly influence neuronal excitability and could mediate the effects of neuroactive agents including neurosteroids and ethanol. However, these receptors can be difficult to study in native cells and recombinant δ subunits can be difficult to express in heterologous systems. EXPERIMENTAL APPROACH We engineered concatemeric (fused) subunits to ensure δ and α4 subunit expression. We tested the pharmacology of the concatemeric receptors, compared with a common synaptic-like receptor subunit combination (α1 +β2 +γ2L), and with free-subunit α4/δ receptors, expressed in Xenopus oocytes. KEY RESULTS δ-β2 −α4 +β2-α4 cRNA co-injected into Xenopus oocytes resulted in GABA-gated currents with the expected pharmacological properties of α4/δ-containing receptors. Criteria included sensitivity to agonists of different efficacy, sensitivity to the allosteric activator pentobarbital, and modulation of agonist responses by DS2 (4-chloro-N-[2-(2-thienyl)imidazo[1,2-a]pyridine-3-yl benzamide; a δ-selective positive modulator), furosemide, and Zn2+. We used the concatemers to examine neurosteroid sensitivity of extrasynaptic-like, δ-containing receptors. We found no qualitative differences between extrasynaptic-like receptors and synaptic-like receptors in the actions of either negative or positive neurosteroid modulators of receptor function. Quantitative differences were explained by the partial agonist effects of the natural agonist GABA and by a mildly increased sensitivity to low steroid concentrations. CONCLUSIONS AND IMPLICATIONS The neurosteroid structure-activity profile for α4/δ-containing extrasynaptic receptors is unlikely to differ from that of synaptic-like receptors such as α1/β2/γ2-containing receptors. PMID:21950777

Expression of the macrophage scavenger receptor, a multifunctional lipoprotein receptor, in microglia associated with senile plaques in Alzheimer's disease.

PubMed Central

Christie, R. H.; Freeman, M.; Hyman, B. T.

1996-01-01

The macrophage scavenger receptor is a multifunctional receptor whose ligands include oxidized low density lipoprotein (LDL), as well as several other polyanionic macromolecules. Although the capacity of the receptor to bind modified LDL has implicated it in the process of atherosclerosis, its physiological role remains uncertain. We have examined human brain for expression of macrophage scavenger receptor as part of ongoing studies of lipoprotein receptors in the central nervous system. The receptor is expressed on microglia, but not on astrocytes, neurons, or vessel-associated structures. In Alzheimer disease, there is strong expression of the scavenger receptor in association with senile plaques. Images Figure 2 Figure 3 Figure 4 PMID:8579103

High throughput functional assays for P2X receptors.

PubMed

Namovic, Marian T; Jarvis, Michael F; Donnelly-Roberts, Diana

2012-06-01

Adenosine triphosphate (ATP) activates two receptor superfamilies, metabotropic P2Y and ionotropic P2X receptors. The P2X receptors are nonselective cation channels that are widely expressed on excitable cells including neurons, glia, and smooth muscle cells. The protocols in this unit are useful for evaluating ligands that interact with P2X receptors on native cells or that are cloned and expressed in recombinant heterologous cell systems. Calcium imaging methods are described for the pharmacological characterization of fast or slowly desensitizing P2X receptors. While these methods are readily applicable to a wide variety of ligand-gated ion channels, the protocols provided herein detail how they can be used to measure activation of homomeric P2X3 (fast desensitizing) and heteromeric P2X2/3 (slowly desensitizing) receptors. Appropriate agonists and/or calcium dyes can be substituted to assess activity at other P2X receptor subtypes. An additional protocol is provided for measuring P2X7 receptor-mediated pore formation in THP-1, a native human acute monocytic leukemia cell line that can be used to study homomeric P2X7 (non-desensitizing) receptors that are expressed on macrophages and microglial cells. © 2012 by John Wiley & Sons, Inc.

Phrenic motoneuron expression of serotonergic and glutamatergic receptors following upper cervical spinal cord injury

PubMed Central

Mantilla, Carlos B.; Bailey, Jeffrey P.; Zhan, Wen-Zhi; Sieck, Gary C.

2012-01-01

Following cervical spinal cord injury at C2 (SH hemisection model) there is progressive recovery of phrenic activity. Neuroplasticity in the postsynaptic expression of neurotransmitter receptors may contribute to functional recovery. Phrenic motoneurons express multiple serotonergic (5-HTR) and glutamatergic (GluR) receptors, but the timing and possible role of these different neurotransmitter receptor subtypes in the neuroplasticity following SH are not clear. The current study was designed to test the hypothesis that there is an increased expression of serotonergic and glutamatergic neurotransmitter receptors within phrenic motoneurons after SH. In adult male rats, phrenic motoneurons were labeled retrogradely by intrapleural injection of Alexa 488-conjugated cholera toxin B. In thin (10 μm) frozen sections of the spinal cord, fluorescently-labeled phrenic motoneurons were visualized for laser capture microdissection (LCM). Using quantitative real-time RT-PCR in LCM samples, the time course of changes in 5-HTR and GluR mRNA expression was determined in phrenic motoneurons up to 21 days post-SH. Expression of 5-HTR subtypes 1b, 2a and 2c and GluR subtypes AMPA, NMDA, mGluR1 and mGluR5 was evident in phrenic motoneurons from control and SH rats. Phrenic motoneuron expression of 5-HTR2a increased ~8-fold (relative to control) at 14 days post-SH, whereas NMDA expression increased ~16-fold by 21-days post-SH. There were no other significant changes in receptor expression at any time post-SH. This is the first study to systematically document changes in motoneuron expression of multiple neurotransmitter receptors involved in regulation of motoneuron excitability. By providing information on the neuroplasticity of receptors expressed in a motoneuron pool that is inactivated by a higher-level spinal cord injury, appropriate pharmacological targets can be identified to alter motoneuron excitability. PMID:22227062

Role of insulin receptor and insulin signaling on αPS2CβPS integrins' lateral diffusion.

PubMed

Mainali, Dipak; Syed, Aleem; Arora, Neha; Smith, Emily A

2014-12-01

Integrins are ubiquitous transmembrane receptors with adhesion and signaling properties. The influence of insulin receptor and insulin signaling on αPS2CβPS integrins' lateral diffusion was studied using single particle tracking in S2 cells before and after reducing the insulin receptor expression or insulin stimulation. Insulin signaling was monitored by Western blotting for phospho-Akt expression. The expression of the insulin receptor was reduced using RNA interference (RNAi). After insulin receptor RNAi, four significant changes were measured in integrin diffusion properties: (1) there was a 24% increase in the mobile integrin population, (2) 14% of the increase was represented by integrins with Brownian diffusion, (3) for integrins that reside in confined zones of diffusion, there was a 45% increase in the diameter of the confined zone, and (4) there was a 29% increase in the duration integrins spend in confined zones of diffusion. In contrast to reduced expression of the insulin receptor, which alters integrin diffusion properties, insulin stimulation alone or insulin stimulation under conditions of reduced insulin receptor expression have minimal effects on altering the measured integrin diffusion properties. The differences in integrin diffusion measured after insulin receptor RNAi in the presence or absence of insulin stimulation may be the result of other insulin signaling pathways that are activated at reduced insulin receptor conditions. No change in the average integrin diffusion coefficient was measured for any conditions included in this study.

Adrenoceptors in Brain: Cellular Gene Expression and Effects on Astrocytic Metabolism and [Ca2+]i

PubMed Central

Hertz, Leif; Lovatt, Ditte; Goldman, Steven A.; Nedergaard, Maiken

2010-01-01

Recent in vivo studies have established astrocytes as a major target for locus coeruleus activation (Bekar et al., Cereb. Cortex 18, 2789–2795), renewing interest in cell culture studies on noradrenergic effects on astrocytes in primary cultures and calling for additional information about the expression of adrenoceptor subtypes on different types of brain cells. In the present communication, mRNA expression of α1-, α2- and β-adrenergic receptors and their subtypes was determined in freshly-isolated, cell marker-defined populations of astrocytes, NG2-positive cells, microglia, endothelial cells, and Thy1-positive neurons (mainly glutamatergic projection neurons) in murine cerebral cortex. Immediately after dissection of frontal, parietal and occipital cortex of 10–12-week-old transgenic mice, which combined each cell-type marker with a specific fluorescent signal, the tissue was digested, triturated and centrifuged, yielding a solution of dissociated cells of all types, which were separated by fluorescence-activated cell sorting (FACS). mRNA expression in each cell fraction was determined by microarray analysis. α1A-Receptors were unequivocally expressed in astrocytes and NG2-positive cells, but absent in other cell types, and α1B-receptors were not expressed in any cell population. Among α2-receptors only α2A-receptors were expressed, unequivocally in astrocytes and NG-positive cells, tentatively in microglia and questionably in Thy1-positive neurons and endothelial cells. β1-Receptors were unequivocally expressed in astrocytes, tentatively in microglia, and questionably in neurons and endothelial cells, whereas β2-adrenergic receptors showed tentative expression in neurons and astrocytes and unequivocal expression in other cell types. This distribution was supported by immunochemical data and its relevance established by previous studies in well-differentiated primary cultures of mouse astrocytes, showing that stimulation of α2-adrenoceptors increases glycogen formation and oxidative metabolism, the latter by a mechanism depending on intramitochondrial Ca2+, whereas α1-adrenoceptor stimulation enhances glutamate uptake, and β-adrenoceptor activation causes glycogenolysis and increased Na+,K+-ATPase activity. The Ca2+- and cAMP-mediated association between energy-consuming and energy-yielding processes is emphasized. PMID:20380860

Functional importance of GLP-1 receptor species and expression levels in cell lines.

PubMed

Knudsen, Lotte Bjerre; Hastrup, Sven; Underwood, Christina Rye; Wulff, Birgitte Schjellerup; Fleckner, Jan

2012-04-10

Of the mammalian species, only the GLP-1 receptors of rat and human origin have been described and characterized. Here, we report the cloning of the homologous GLP-1 receptors from mouse, rabbit, pig, cynomolgus monkey and chimp. The GLP-1 receptor is highly conserved across species, thus underlining the physiological importance of the peptide hormone and its receptor across a wide range of mammals. We expressed the receptors by stable transfection of BHK cells, both in cell lines with high expression levels of the cloned receptors, as well as in cell lines with lower expression levels, more comparable to endogenous expression of these receptors. High expression levels of cloned GLP-1 receptors markedly increased the potency of GLP-1 and other high affinity ligands, whereas the K(d) values were not affected. For a low affinity ligand like the ago-allosteric modulator Compound 2, expression levels of the human GLP-1 receptor were important for maximal efficacy as well as potency. The two natural metabolites of GLP-1, GLP-1(9-37) and GLP-1(9-36)amide were agonists when tested on a cell line with high expression of the recombinant human GLP-1 receptor, whereas they behaved as (low potent) antagonists on a cell line that expressed the receptor endogenously, as well as cells expressing a moderate level of the recombinant human GLP-1 receptor. The amide form was a more potent agonist than the free acid from. In conclusion, receptor expression level is an important parametre for selecting cell lines with cloned GLP-1 receptors for functional characterization of physiological and pharmaceutical ligands. Copyright © 2011 Elsevier B.V. All rights reserved.

Early exposure to caffeine affects gene expression of adenosine receptors, DARPP-32 and BDNF without affecting sensibility and morphology of developing zebrafish (Danio rerio).

PubMed

Capiotti, Katiucia Marques; Menezes, Fabiano Peres; Nazario, Luiza Reali; Pohlmann, Julhana Bianchini; de Oliveira, Giovanna M T; Fazenda, Lidiane; Bogo, Maurício Reis; Bonan, Carla Denise; Da Silva, Rosane Souza

2011-01-01

Adenosine receptors are the most important biochemical targets of caffeine, a common trimethylxanthine found in food and beverages. Adenosine plays modulatory action during the development through adenosine receptors and their intracellular pathways activation. In this study, we aimed to evaluate if caffeine gave to zebrafish in the very first steps of development is able to affect its direct targets, through the adenosine receptors mRNA expression evaluation, and latter indirect targets, through evaluation of the pattern of dopamine and cAMP-regulated phosphoprotein and brain-derived neurotrophic factor (BDNF) mRNA expression. Here, we demonstrate that zebrafish express adenosine receptor subtypes (A1, A2A1, A2A2 and A2B) since 24h post-fertilization (hpf) and that caffeine exposure is able to affect the expression of these receptors. Caffeine exposure from 1 hpf is able to increase A1 expression at 72-96 hpf and A2A1 expression at 72 hpf. No alterations occurred in A2A2 and A2B expression after caffeine treatment. DARPP-32, a phosphoprotein involved in adenosine intracellular pathway is also expressed since 24 hpf and early exposure to caffeine increased DARPP-32 expression at 168 hpf. We also evaluate the expression of BDNF as one of the targets of adenosine intracellular pathway activation. BDNF was also expressed since 24 hpf and caffeine treatment increased its expression at 48 and 72 hpf. No morphological alterations induced by caffeine treatment were registered by the check of general body features and total body length. Assessment of tactile sensibility also demonstrated no alterations by caffeine treatment. Altogether, these results suggest that caffeine is able to affect expression of its cellular targets since early phases of development in zebrafish without affect visible features. The up-regulation of direct and indirect targets of caffeine presents as a compensatory mechanism of maintenance of adenosinergic modulation during the developmental phase. Copyright © 2011 Elsevier Inc. All rights reserved.

Differential relationships between D1 and D2 dopamine receptor expression in the medial preoptic nucleus and sexually-motivated song in male European starlings (Sturnus vulgaris)

PubMed Central

DeVries, M. S.; Cordes, M.A.; Stevenson, S.A.; Riters, L.V.

2015-01-01

Converging data in songbirds support a central role for the medial preoptic nucleus (POM) in motivational aspects of vocal production. Recent data suggest that dopamine in the POM plays a complex modulatory role in the production of sexually-motivated song and that an optimal level of dopamine D1 receptor stimulation is required to facilitate singing behavior. To further explore this possibility, we used quantitative real time PCR to examine relationships between mRNA expression of D1 as well as D2 receptors in the POM (and also the lateral septum and Area X) and sexually-motivated singing behavior in male European starlings. Results showed that both males with the highest and lowest D1 expression in the POM sang significantly less than males with intermediate levels of expression. Furthermore, singing behavior rose linearly in association with increasing levels of D1 expression in POM but dropped abruptly, such that individuals with D1 expression values higher than the mean sang very little. Analysis of birds with low and intermediate levels of D1 expression in POM revealed strong positive correlations between D1 expression and song but negative relationships between D2 receptor expression and song. These findings support prior work suggesting an optimal level of POM D1 receptor stimulation best facilitates sexually-motivated singing behavior. Results also suggest that D2 receptors may work in opposition to D1 receptors in POM to modify vocal production. PMID:26079111

Role of hypothalamic cannabinoid receptors in post-stroke depression in rats.

PubMed

Wang, Shanshan; Sun, Hong; Liu, Sainan; Wang, Ting; Guan, Jinqun; Jia, Jianjun

2016-03-01

One of the most common psychological consequences of stroke is post-stroke depression (PSD). While more than 30 percent of stroke patients eventually develop PSD, the neurobiological mechanisms underlying such a phenomenon have not been well investigated. Given the critical involvement of hypothalamic-pituitary-adrenal axis and endocannabinoid system in response to stressful stimuli, we evaluated the hypothesis that cannabinoid receptors in the hypothalamus are critical for modulation of post-stroke depression-like behaviors in rats. To this end, rats were treated with middle cerebral artery occlusion (MCAO) followed by chronic unpredictable mild stress (CUMS) treatment procedure. We then assessed the expression of CB1 and CB2 receptors in the hypothalamus, and evaluated the effects of pharmacological stimulations of CB1 or CB2 receptors on the expression and development of depression-like behaviors in PSD rats. We found that PSD rats exhibited decreased the expression of CB1 receptor, but not CB2 receptor, in the ventral medial hypothalamus (VMH). Such an effect was not observed in the dorsally adjacent brain regions. Furthermore, intra-VMH injections of CB2 receptor agonist, but not CB1 receptor agonist, attenuated the expression of depression-like behaviors in PSD rats. Finally, repeated intraperitoneal injections of CB1 or CB2 receptor agonists during CUMS treatment inhibited the development of depression-like behaviors in PSD rats. Taken together, these results suggest that decreased CB1 receptor expression is likely associated with the development of post-stroke depression, and CB2 receptor may be a potential therapeutic target for the treatment post-stroke depressive disorders. Copyright © 2016 Elsevier Inc. All rights reserved.

Human Endometriosis Tissue Microarray Reveals Site-specific Expression of Estrogen Receptors, Progesterone Receptor, and Ki67.

PubMed

Colón-Caraballo, Mariano; García, Miosotis; Mendoza, Adalberto; Flores, Idhaliz

2018-04-07

Most available therapies for endometriosis are hormone-based and generally broadly used without taking into consideration the ovarian hormone receptor expression status. This contrasts strikingly with the standard of care for other hormone-based conditions such as breast cancer. We therefore aimed to characterize the expression of ovarian steroid hormone receptors for estrogen alpha (ESR1), estrogen beta (ESR2), and progesterone (PGR) in different types of endometriotic lesions and eutopic endometrium from women with endometriosis and controls using a tissue microarray (TMA). Nuclear expression levels of the receptors were analyzed by tissue (ie, ectopic vs. eutopic endometrium) and cell type (ie, glands vs. stroma). Ovarian lesions showed the lowest expression of ESR1 and PGR, and the highest expression of ESR2, whereas the fallopian tube lesions showed high expression of the 3 receptors. Differences among endometria included lower expression of ESR1 and higher expression of ESR2 in stroma of proliferative endometrium from patients versus patients, and a trend towards loss of PGR nuclear positivity in proliferative endometrium from patients. The largest ESR2:ESR1 ratios were observed in ovarian lesions and secretory endometrium. The highest proportion of samples with >10% Ki67 positive nuclei was in glands of fallopian tube (54%) and extrapelvic lesions (75%); 60% of glands of secretory endometrium from patients had >10% Ki67 positivity compared with only 15% in controls. Our results provide a better understanding of endometriosis heterogeneity by revealing lesion type-specific differences and case-by-case variability in the expression of ovarian hormone receptors. This knowledge could potentially predict individual responses to hormone therapies, and set the basis for the application of personalized medicine approaches for women with endometriosis.

Differential expression of ligands for NKG2D and DNAM-1 receptors by epithelial ovarian cancer-derived exosomes and its influence on NK cell cytotoxicity.

PubMed

Labani-Motlagh, Alireza; Israelsson, Pernilla; Ottander, Ulrika; Lundin, Eva; Nagaev, Ivan; Nagaeva, Olga; Dehlin, Eva; Baranov, Vladimir; Mincheva-Nilsson, Lucia

2016-04-01

Cancers constitutively produce and secrete into the blood and other biofluids 30-150 nm-sized endosomal vehicles called exosomes. Cancer-derived exosomes exhibit powerful influence on a variety of biological mechanisms to the benefit of the tumors that produce them. We studied the immunosuppressive ability of epithelial ovarian cancer (EOC) exosomes on two cytotoxic pathways of importance for anticancer immunity-the NKG2D receptor-ligand pathway and the DNAM-1-PVR/nectin-2 pathway. Using exosomes, isolated from EOC tumor explant and EOC cell-line culture supernatants, and ascitic fluid from EOC patients, we studied the expression of NKG2D and DNAM-1 ligands on EOC exosomes and their ability to downregulate the cognate receptors. Our results show that EOC exosomes differentially and constitutively express NKG2D ligands from both MICA/B and ULBP families on their surface, while DNAM-1 ligands are more seldom expressed and not associated with the exosomal membrane surface. Consequently, the NKG2D ligand-bearing EOC exosomes significantly downregulated the NKG2D receptor expression on peripheral blood mononuclear cells (PBMC) while the DNAM-1 receptor was unaffected. The downregulation of NKG2D receptor expression was coupled to inhibition of NKG2D receptor-ligand-mediated degranulation and cytotoxicity measured in vitro with OVCAR-3 and K562 cells as targets. The EOC exosomes acted as a decoy impairing the NKG2D mediated cytotoxicity while the DNAM-1 receptor-ligand system remained unchanged. Taken together, our results support and explain the mechanism behind the recently reported finding that in EOC, NK-cell recognition and killing of tumor cells was mainly dependent on DNAM-1 signaling while the contribution of the NKG2D receptor-ligand pathway was complementary and uncertain.

Toll-like receptors 2 and 4 exert opposite effects on the contractile response induced by serotonin in mouse colon: role of serotonin receptors.

PubMed

Forcén, R; Latorre, E; Pardo, J; Alcalde, A I; Murillo, M D; Grasa, L

2016-08-01

What is the central question of this study? The action of Toll-like receptors (TLRs) 2 and 4 on the motor response to serotonin in mouse colon has not previously been reported. What is the main finding and its importance? Toll-like receptors 2 and 4 modulate the serotonin-induced contractile response in mouse colon by modifying the expression of serotonin (5-HT) receptors. Alterations in 5-HT2A and 5-HT2C receptors explain the increase of the response to serotonin in TLR2(-/-) mice. Alterations in 5-HT2C and 5-HT4 receptors explain the suppression of the response to serotonin in TLR4(-/-) mice. The microbiota, through Toll-like receptors (TLRs), may regulate gastrointestinal motility by activating neuroendocrine mechanisms. We evaluated the influence of TLR2 and TLR4 in spontaneous contractions and in the serotonin (5-HT)-induced motor response in mouse colon, and assessed the 5-HT receptors involved. Muscle contractility studies to evaluate the intestinal spontaneous motility and the response to 5-HT were performed in the colon from wild-type (WT), TLR2(-/-) , TLR4(-/-) and TLR2/4 double knockout (DKO) mice. The 5-HT receptor mRNA expression was determined by real-time PCR. The amplitude and frequency of the spontaneous contractions of the colon were smaller in TLR4(-/-) and TLR2/4 DKO mice with respect to WT mice. In WT, TLR2(-/-) and TLR2/4 DKO mice, 100 μm 5-HT evoked a contractile response. The contractile response induced by 5-HT was significantly higher in TLR2(-/-) than in WT mice. In TLR4(-/-) mice, 5-HT did not evoke any contractile response. The mRNA expression of 5-HT2A was increased in TLR2(-/-) and TLR2/4 DKO mice. The 5-HT2C and 5-HT4 mRNA expressions were increased in TLR4(-/-) and TLR2/4 DKO mice. The 5-HT2C mRNA expression was diminished in TLR2(-/-) mice. The 5-HT3 mRNA expression was increased in TLR2(-/-) , TLR4(-/-) and TLR2/4 DKO mice. The 5-HT7 mRNA expression was diminished in TLR2/4 DKO mice. In WT, TLR2(-/-) and TLR2/4 DKO mice, 5-HT2 , 5-HT3 , 5-HT4 and 5-HT7 receptor antagonists reduced or blocked the contractile response evoked by 5-HT. We postulate that TLR2 and TLR4 modulate the serotonin contractile motor response in mouse colon in an opposing manner by modifying the expression of several serotonin receptors. © 2016 The Authors. Experimental Physiology © 2016 The Physiological Society.

Alterations in Gene and Protein Expression of Cannabinoid CB2 and GPR55 Receptors in the Dorsolateral Prefrontal Cortex of Suicide Victims.

PubMed

García-Gutiérrez, María S; Navarrete, Francisco; Navarro, Gemma; Reyes-Resina, Irene; Franco, Rafael; Lanciego, Jose Luis; Giner, Salvador; Manzanares, Jorge

2018-02-12

Recent studies point to the cannabinoid CB 2 receptors (CB 2 r) and the non-cannabinoid receptor GPR55 as potential key targets involved in the response to stress, anxiety, and depression. Considering the close relationship between neuropsychiatric disorders and suicide, the purpose of this study was to evaluate the potential alterations of CB 2 r and GPR55 in suicide victims. We analyzed gene and protein expression of both receptors by real-time PCR and western blot, respectively, in the dorsolateral prefrontal cortex (DLPFC) of 18 suicide victims with no clinical psychiatric history or treatment with anxiolytics or antidepressants, and 15 corresponding controls. We used in situ proximity ligation assay to evaluate whether the receptors formed heteromeric complexes and to determine the expression level of these heteromers, also assessing the co-expression of heteromers in neurons, astroglia, or microglia cells. CB 2 r and GPR55 gene expressions were significantly lower (by 33 and 41%, respectively) in the DLPFC of suicide cases. CB 2 r protein expression was higher, as were CB 2 -GPR55 heteroreceptor complexes. The results also revealed the presence of CB 2 -GPR55 receptor heteromers in both neurons and astrocytes, whereas microglial cells showed no expression. We did not observe any significant alterations of GPR55 protein expression. Additional studies will be necessary to evaluate if these alterations are reproducible in suicide victims diagnosed with different psychiatric disorders. Taken together, the results suggest that CB 2 r and GPR55 may play a relevant role in the neurobiology of suicide.

Botulinum toxin decreases hyperalgesia and inhibits P2X3 receptor over-expression in sensory neurons induced by ventral root transection in rats.

PubMed

Xiao, Lizu; Cheng, Jianguo; Dai, Juanli; Zhang, Deren

2011-09-01

We aim to determine the effects of Botulinum toxin type A (BTX-A) on neuropathic pain behavior and the expression of P2X(3) receptor in dorsal root ganglion (DRG) in rats with neuropathic pain induced by L5 ventral root transection (L5 VRT). Neuropathic pain was induced by L5 VRT in male Sprague-Dawley rats. Either saline or BTX-A was administered to the plantar surface. Behavioral tests were conducted preoperatively and at predefined postoperative days. The expression of P2X(3) receptors in DRG neurons was detected by immunoreactivity at postoperative days 3, 7, 14, and 21. The number of positive P2X(3) neurons in the ipsilateral L5 DRG increased significantly after L5 VRT (P<0.001). This increase persisted for at least 3 weeks after the operation. No significant changes in P2X(3) expression were detected in the contralateral L5, or in the L4 DRGs bilaterally. Subcutaneous administration of BTX-A, performed on the left hindpaw at days 4, 8, or 16 post VRT surgery, significantly reduced mechanical allodynia bilaterally and inhibited P2X(3) over-expression induced by L5 VRT. L5 VRT led to over-expression of P2X(3) receptors in the L5 DRG and bilateral mechanical allodynia in rats. Subcutaneous injection of BTX-A significantly reversed the neuropathic pain behavior and the over-expression of P2X(3) receptor in nociceptive neurons. These data not only show over-expression of purinergic receptors in the VRT model of neuropathic pain but also reveal a novel mechanism of botulinum toxin action on nociceptive neurons. Wiley Periodicals, Inc.

Estrogen receptor-beta expression in invasive breast cancer in relation to molecular phenotype: results from the Nurses' Health Study.

PubMed

Marotti, Jonathan D; Collins, Laura C; Hu, Rong; Tamimi, Rulla M

2010-02-01

The expression of estrogen receptor-alpha (ER-alpha) and related genes has emerged as one of the major determinants of molecular classification of invasive breast cancers. Expression of a second ER, estrogen receptor-beta (ER-beta), has not been previously evaluated in a large population-based study. Therefore, we examined ER-beta expression in a large population of women with breast cancer to assess its relationship to molecular categories of invasive breast cancer. We constructed tissue microarrays from paraffin blocks of 3093 breast cancers that developed in women enrolled in the Nurses' Health Study. Tissue microarray sections were immunostained for ER-alpha, progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), cytokeratin 5/6, epidermal growth factor receptor (EGFR) and with a monoclonal antibody to ER-beta. Cancers were categorized as luminal A (ER-alpha+ and/or PR+ and HER2-); luminal B (ER-alpha+ and/or PR+ and HER2+); HER2 (ER-alpha- and PR- and HER2+); and basal-like (ER-alpha-, PR-, HER2- and EGFR or cytokeratin 5/6+). The relationship between expression of ER-beta and molecular class of invasive breast cancer was analyzed. Overall, 68% of breast carcinomas were ER-beta+. Expression of ER-beta was significantly associated with expression of ER-alpha (P<0.0001) and PR (P<0.0001), and was inversely related to expression of HER2 (P=0.004), CK5/6 (P=0.02) and EGFR (P=0.006). Among 2170 invasive cancers with complete immunophenotypic data, 73% were luminal A, 5% luminal B, 6 % HER2 and 11% basal-like. ER-beta expression was significantly related to molecular category (P<0.0001) and was more common in luminal A (72% of cases) and B (68% of cases) than in HER2 or basal-like types. However, despite their being defined by the absence of ER-alpha expression, 55% of HER2-type and 60% of basal-like cancers showed expression of ER-beta. The role of ER-beta in the development and progression of breast cancers defined by lack of expression of ER-alpha merits further investigation.

Olfactory discrimination largely persists in mice with defects in odorant receptor expression and axon guidance.

PubMed

Knott, Thomas K; Madany, Pasil A; Faden, Ashley A; Xu, Mei; Strotmann, Jörg; Henion, Timothy R; Schwarting, Gerald A

2012-07-04

The defining feature of the main olfactory system in mice is that each olfactory sensory neuron expresses only one of more than a thousand different odorant receptor genes. Axons expressing the same odorant receptor converge onto a small number of targets in the olfactory bulb such that each glomerulus is made up of axon terminals expressing just one odorant receptor. It is thought that this precision in axon targeting is required to maintain highly refined odor discrimination. We previously showed that β3GnT2(-/-) mice have severe developmental and axon guidance defects. The phenotype of these mice is similar to adenylyl cyclase 3 (AC3) knockout mice largely due to the significant down-regulation of AC3 activity in β3GnT2(-/-) neurons. Microarray analysis reveals that nearly one quarter of all odorant receptor genes are down regulated in β3GnT2(-/-) mice compared to controls. Analysis of OR expression by quantitative PCR and in situ hybridization demonstrates that the number of neurons expressing some odorant receptors, such as mOR256-17, is increased by nearly 60% whereas for others such as mOR28 the number of neurons is decreased by more than 75% in β3GnT2(-/-) olfactory epithelia. Analysis of axon trajectories confirms that many axons track to inappropriate targets in β3GnT2(-/-) mice, and some glomeruli are populated by axons expressing more than one odorant receptor. Results show that mutant mice perform nearly as well as control mice in an odor discrimination task. In addition, in situ hybridization studies indicate that the expression of several activity dependent genes is unaffected in β3GnT2(-/-) olfactory neurons. Results presented here show that many odorant receptors are under-expressed in β3GnT2(-/-) mice and further demonstrate that additional axon subsets grow into inappropriate targets or minimally innervate glomeruli in the olfactory bulb. Odor evoked gene expression is unchanged and β3GnT2(-/-) mice exhibit a relatively small deficit in their ability to discriminate divergent odors. Results suggest that despite the fact that β3GnT2(-/-) mice have decreased AC3 activity, decreased expression of many ORs, and display many axon growth and guidance errors, odor-evoked activity in cilia of mutant olfactory neurons remains largely intact.

Identification and expression analyses of a novel serotonin receptor gene, 5-HT2β, in the field cricket, Gryllus bimaculatus.

PubMed

Watanabe, T; Aonuma, H

2012-01-01

Biogenic amine serotonin (5-HT) modulates various aspects of behaviors such as aggressive behavior and circadian behavior in the cricket. In our previous report, in order to elucidate the molecular basis of the cricket 5-HT system, we identified three genes involved in 5-HT biosynthesis, as well as four 5-HT receptor genes (5-HT1A, 5-HT1B, 5-HT2α, and 5-HT7) expressed in the brain of the field cricket Gryllus bimaculatus DeGeer [7]. In the present study, we identified Gryllus 5-HT2β gene, an additional 5-HT receptor gene expressed in the cricket brain, and examined its tissue-specific distribution and embryonic stage-dependent expression. Gryllus 5-HT2β gene was ubiquitously expressed in the all examined adult tissues, and was expressed during early embryonic development, as well as during later stages. This study suggests functional differences between two 5-HT2 receptors in the cricket.

Postsynaptic Synaptotagmins Mediate AMPA Receptor Exocytosis During LTP

PubMed Central

Wu, Dick; Bacaj, Taulant; Morishita, Wade; Goswami, Debanjan; Arendt, Kristin L.; Xu, Wei; Chen, Lu; Malenka, Robert C.; Südhof, Thomas C.

2017-01-01

Strengthening of synaptic connections by NMDA-receptor-dependent long-term potentiation (LTP) shapes neural circuits and mediates learning and memory. During NMDA-receptor-dependent LTP induction, Ca2+-influx stimulates recruitment of synaptic AMPA-receptors, thereby strengthening synapses. How Ca2+ induces AMPA-receptor recruitment, however, remains unclear. Here we show that, in pyramidal neurons of the hippocampal CA1-region, blocking postsynaptic expression of both synaptotagmin-1 and synaptotagmin-7, but not of synaptotagmin-1 or synaptotagmin-7 alone, abolished LTP. LTP was rescued by wild-type but not by Ca2+-binding-deficient mutant synaptotagmin-7. Blocking postsynaptic synaptotagmin-1/7 expression did not impair basal synaptic transmission, synaptic or extrasynaptic AMPA-receptor levels, or other AMPA-receptor trafficking events. Moreover, expression of dominant-negative mutant synaptotagmin-1 that inhibited Ca2+-dependent presynaptic vesicle exocytosis also blocked Ca2+-dependent postsynaptic AMPA-receptor exocytosis, thereby abolishing LTP. Our results suggest that postsynaptic synaptotagmin-1 and synaptotagmin-7 act as redundant Ca2+-sensors for Ca2+-dependent exocytosis of AMPA-receptors during LTP, thus delineating a simple mechanism for the recruitment of AMPA-receptors that mediates LTP. PMID:28355182

Changes in protein and gene expression of angiotensin II receptors (AT1 and AT2) in aorta of diabetic and hypertensive rats.

PubMed

Romero-Nava, R; Rodriguez, J E; Reséndiz-Albor, A A; Sánchez-Muñoz, F; Ruiz-Hernandéz, A; Huang, F; Hong, E; Villafaña, S

2016-01-01

Diabetes and hypertension have been associated with cardiovascular diseases and stroke. Some reports have related the coexistence of hypertension and diabetes with increase in the risk of developing vascular complications. Recently some studies have shown results suggesting that in the early stages of diabetes and hypertension exist a reduced functional response to vasopressor agents like angiotensin II (Ang II), which plays an important role in blood pressure regulation mechanism through the activation of its AT1 and AT2 receptors. For that reason, the aim of this work was to study the gene and protein expression of AT1 and AT2 receptors in aorta of diabetic SHR and WKY rats. Diabetes was induced by the administration of streptozotocin (60 mg/kg i.p.). After 4 weeks of the onset of diabetes, the protein expression was obtained by western blot and the mRNA expression by RT-PCR. Our results showed that the hypertensive rats have a higher mRNA and protein expression of AT1 receptors than normotensive rats while the AT2 expression remained unchanged. On the other hand, the combination of diabetes and hypertension increased the mRNA and protein expression of AT1 and AT2 receptors significantly. In conclusion, our results suggest that diabetes with hypertension modifies the mRNA and protein expression of AT1 and AT2 receptors. However, the overexpression of AT2 could be associated with the reduction in the response to Ang II in the early stage of diabetes.

The Mechanism of Functional Up-Regulation of P2X3 Receptors of Trigeminal Sensory Neurons in a Genetic Mouse Model of Familial Hemiplegic Migraine Type 1 (FHM-1)

PubMed Central

Hullugundi, Swathi K.; Ferrari, Michel D.; van den Maagdenberg, Arn M. J. M.; Nistri, Andrea

2013-01-01

A knock-in (KI) mouse model of FHM-1 expressing the R192Q missense mutation of the Cacna1a gene coding for the α1 subunit of CaV2.1 channels shows, at the level of the trigeminal ganglion, selective functional up-regulation of ATP -gated P2X3 receptors of sensory neurons that convey nociceptive signals to the brainstem. Why P2X3 receptors are constitutively more responsive, however, remains unclear as their membrane expression and TRPV1 nociceptor activity are the same as in wildtype (WT) neurons. Using primary cultures of WT or KI trigeminal ganglia, we investigated whether soluble compounds that may contribute to initiating (or maintaining) migraine attacks, such as TNFα, CGRP, and BDNF, might be responsible for increasing P2X3 receptor responses. Exogenous application of TNFα potentiated P2X3 receptor-mediated currents of WT but not of KI neurons, most of which expressed both the P2X3 receptor and the TNFα receptor TNFR2. However, sustained TNFα neutralization failed to change WT or KI P2X3 receptor currents. This suggests that endogenous TNFα does not regulate P2X3 receptor responses. Nonetheless, on cultures made from both genotypes, exogenous TNFα enhanced TRPV1 receptor-mediated currents expressed by a few neurons, suggesting transient amplification of TRPV1 nociceptor responses. CGRP increased P2X3 receptor currents only in WT cultures, although prolonged CGRP receptor antagonism or BDNF neutralization reduced KI currents to WT levels. Our data suggest that, in KI trigeminal ganglion cultures, constitutive up-regulation of P2X3 receptors probably is already maximal and is apparently contributed by basal CGRP and BDNF levels, thereby rendering these neurons more responsive to extracellular ATP. PMID:23577145

Transient receptor potential channel M5 and phospholipaseC-beta2 colocalizing in zebrafish taste receptor cells.

PubMed

Yoshida, Yuki; Saitoh, Kana; Aihara, Yoshiko; Okada, Shinji; Misaka, Takumi; Abe, Keiko

2007-10-08

In mammals, transient receptor potential (TRP) channel M5 (TRPM5) is coexpressed with phospholipaseC-beta2 (PLC-beta2) in the taste receptor cells, and both PLC-beta2 and TRPM5 are essential elements in the signal transduction of sweet, bitter and umami stimuli. In this study, we identified the zebrafish homologue of TRPM5 (zfTRPM5) and examined its expression in the gustatory system by in-situ hybridization. Using a transgenic zebrafish line that expressed green fluorescent protein under the control of the PLC-beta2 promoter, we showed that zfTRPM5 is expressed in green fluorescent protein-labeled cells of the taste buds. These results demonstrate that zfTRPM5 and PLC-beta2 colocalize in zebrafish taste receptor cells, suggesting their crucial roles in taste signaling via the fish taste receptors.

GABAA receptor subunit gene expression in human prefrontal cortex: comparison of schizophrenics and controls

NASA Technical Reports Server (NTRS)

Akbarian, S.; Huntsman, M. M.; Kim, J. J.; Tafazzoli, A.; Potkin, S. G.; Bunney, W. E. Jr; Jones, E. G.; Bloom, F. E. (Principal Investigator)

1995-01-01

The prefrontal cortex of schizophrenics is hypoactive and displays changes related to inhibitory, GABAergic neurons, and GABAergic synapses. These changes include decreased levels of glutamic acid decarboxylase (GAD), the enzyme for GABA synthesis, upregulation of muscimol binding, and downregulation of benzodiazepine binding to GABAA receptors. Studies in the visual cortex of nonhuman primates have demonstrated that gene expression for GAD and for several GABAA receptor subunit polypeptides is under control of neuronal activity, raising the possibility that similar mechanisms in the hypoactive prefrontal cortex of schizophrenics may explain the abnormalities in GAD and in GABAA receptor regulation. In the present study, which is the first of its type on human cerebral cortex, levels of mRNAs for six GABAA receptor subunits (alpha 1, alpha 2, alpha 5, beta 1, beta 2, gamma 2) and their laminar expression patterns were analyzed in the prefrontal cortex of schizophrenics and matched controls, using in situ hybridization histochemistry and densitometry. Three types of laminar expression pattern were observed: mRNAs for the alpha 1, beta 2, and gamma 2 subunits, which are the predominant receptor subunits expressed in the mature cortex, were expressed at comparatively high levels by cells of all six cortical layers, but most intensely by cells in lower layer III and layer IV. mRNAs for the alpha 2, alpha 5, and beta 1 subunits were expressed at lower levels; alpha 2 and beta 1 were expressed predominantly by cells in layers II, III, and IV; alpha 5 was expressed predominantly in layers IV, V, and VI. There were no significant changes in overall mRNA levels for any of the receptor subunits in the prefrontal cortex of schizophrenics, and the laminar expression pattern of all six receptor subunit mRNAs did not differ between schizophrenics and controls. Because gene expression for GABAA receptor subunits is not consistently altered in the prefrontal cortex of schizophrenics, the previously reported upregulation of muscimol binding sites and downregulation of benzodiazepine binding sites in the prefrontal and adjacent cingulate cortex of schizophrenics are possibly due to posttranscriptional modifications of mRNAs and their translated polypeptides.

Progestin treatment does not affect expression of cytokines, steroid receptors, oxytocin receptor, and cyclooxygenase 2 in fetal membranes and endometrium from pony mares at parturition.

PubMed

Palm, F; Walter, I; Nowotny, N; Budik, S; Helmreich, M; Aurich, C

2013-01-01

In most mammalian species, progestins have a major function in maintaining pregnancy. In humans, the physiologic initiation of parturition bears similarities with inflammatory processes and anti-inflammatory effects of progestins have been suggested to postpone birth until term. To examine if comparable effects exist in the horse, mares were treated with the synthetic progestin altrenogest from day 280 of gestation until parturition (N = 5) or were left untreated as controls (N = 7). Tissue from the amnion (AMN), allantochorion (AC), and endometrium (EM) was collected at foaling and mRNA expression of interleukin (IL)-6 and -8, cyclooxygenase 2 (COX2), estrogen receptor (ER) α, progesterone receptor, and oxytocin receptor (OTR) was analyzed. Leukocytes, steroid receptors, COX2, and OTR were also investigated by histology and immunohistochemistry. Expression of mRNA for IL-6 was higher in AMN and EM versus AC (P < 0.01). Expression of IL-8 was higher in AMN than AC and EM (P < 0.001). Steroid receptors and OTR were highly expressed in EM but not in AMN and AC (P < 0.001). Expression of COX2 was most pronounced in AC whereas IL expression was not upregulated in AC. No differences in mRNA expression existed between altrenogest-treated and control animals. Endometrial polymorphonuclear leukocytes were increased in altrenogest-treated mares. Epithelial cells of all tissues, except AC chorionic villi stained progesterone receptor-positive. Staining for ER was more pronounced in the amnion facing epithelium of the AC in altrenogest-treated versus control animals (P < 0.01). In conclusion, COX2 is highly expressed in the AC. The fetal membranes thus might play a role in the onset of labor in the horse. Altrenogest did not affect gene expression in the AMN, AC, and EM but had localized effects on inflammatory cells and ER expression. No anti-inflammatory effects of altrenogest in healthy, late pregnant pony mares could be detected. Copyright © 2013 Elsevier Inc. All rights reserved.

Temporal and regional alterations in NMDA receptor expression in Mecp2-null mice

PubMed Central

Blue, Mary E.; Kaufmann, Walter E.; Bressler, Joseph; Eyring, Charlotte; O’Driscoll, Cliona; Naidu, SakkuBai; Johnston, Michael V.

2014-01-01

Our previous postmortem study of girls with Rett Syndrome (RTT), a development disorder caused by MECP2 mutations, found increases in the density of NMDA receptors in the prefrontal cortex of 2–8 year-old girls, while girls older than 10 years had reductions in NMDA receptors compared to age matched controls (Blue et al., 1999b). Using [3H]-CGP to label NMDA type glutamate receptors in 2 and 7 week old wildtype (WT), Mecp2-null and Mecp2-heterozygous (HET) mice (Bird model), we found that frontal areas of the brain also exhibited a bimodal pattern in NMDA expression, with increased densities of NMDA receptors in Mecp2-null mice at 2 weeks of age, but decreased densities at 7 weeks of age. Visual cortex showed a similar pattern, while other cortical regions only exhibited changes in NMDA receptor densities at 2 weeks (retrosplenial granular) or 7 weeks (somatosensory). In thalamus of null mice, NMDA receptors were increased at 2 and 7 weeks. No significant differences in density were found between HET and WT mice at both ages. Western blots for NMDAR1 expression in frontal brain showed higher levels of expression in Mecp2-null mice at two weeks of age, but not at 1 or 7 weeks of age. Our mouse data support the notion that deficient MeCP2 function is the primary cause of the NMDA receptor changes we observed in RTT. Furthermore, the findings of regional and temporal differences in NMDA expression illustrate the importance of age and brain region in evaluating different genotypes of mice. PMID:21901842

Expression of mammalian beta-adrenergic receptors in Xenopus laevis oocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bahouth, S.W.; Malbon, C.C.

1987-05-01

Xenopus laevis oocytes are a useful transcription and expression system for DNA and RNA, respectively. Total cellular RNA was extracted from mouse lymphoma S49 cells and poly(A)/sup +/mRNA prepared by affinity chromatography of RNA on oligo(dT) cellulose. The membranes of S49 cells contain beta-adrenergic receptors that display pharmacological characteristics of beta/sub 2/-subtype. Xenopus laevis oocytes were injected with 50 ng of mRNA/oocyte. Expression of beta-adrenergic receptors in oocytes incubated for 30 hr after microinjection was assessed in membranes by radioligand binding using (/sup 3/H) dihydroalprenolol. The injected oocytes displayed 0.34 fmol receptor/oocyte as compared to 0.02 fmol receptor/oocyte in themore » control oocytes. The affinity of beta-adrenergic receptors in injected oocytes for this radioligand was 2 nM, a value similar to the affinity of beta-adrenergic receptors for DHA in S49 cell membranes. The potency of beta-adrenergic agonists in competing for DHA binding to oocytes membranes was isoproterenol > epinephrine > norepineprine, indicating that the expressed beta-adrenergic receptors were of the beta/sub 2/-subtype. The K/sub I/ of these agonists for the beta-adrenergic receptor in oocyte membranes was 0.03, 0.15 and 1.2 ..mu..M, respectively. The role of post-translational modification in dictating receptor subtype is analyzed using mRNA of beta/sub 1/- as well as beta/sub 2/-adrenergic receptors.« less

The effect of melatonin from slow-release implants on basic and TLR-4-mediated gene expression of inflammatory cytokines and their receptors in the choroid plexus in ewes.

PubMed

Kowalewska, M; Herman, A P; Szczepkowska, A; Skipor, J

2017-08-01

The present study concerns the effect of melatonin from slow-release implants on the expression of genes coding interleukin-1β (Il1B), inerleukin-6 (Il6), tumour necrosis factor α (Tnf) and their receptors: IL-1 receptor type I (Il1r1) and type II (Il1r2), IL-6 receptor (Il6r) and signal transducer (Il6st), TNFα receptor type I (Tnfrsf1a) and II (Tnfrsf1b) and retinoid-related orphan receptor α (RorA) and Rev.-erbα in the ovine choroid plexus (CP) under basal and lipopolysaccharide (LPS)-challenged conditions. Studies were performed on four groups: 1) sham-implanted and placebo-treated, 2) melatonin-implanted (Melovine, 18mg) and placebo-treated, 3) sham-implanted and LPS-treated (400ng/kg of body weight) and 4) melatonin-implanted and LPS-treated. Under basal conditions, we observed weak expression of Tnf, low expression of Il1B, Il6 and Il1r2 and intermediate expression of other cytokines receptors. LPS treatment induced (P≤0.05) expression in all cytokines and their receptors, except Il6r 3h after the administration. Melatonin attenuated (P≤0.05) LPS-induced up-regulation of Il6 but had no effect on other cytokines and their receptors and up-regulated (P≤0.05) Rev.-erbα expression under basal conditions. This indicates that melatonin from slow-release implants suppresses TLR4-mediated Il6 expression in the ovine CP via a mechanism likely involving clock genes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterization of cannabinoid receptor ligands in tissues natively expressing cannabinoid CB2 receptors

PubMed Central

Marini, Pietro; Cascio, Maria-Grazia; King, Angela; Pertwee, Roger G; Ross, Ruth A

2013-01-01

Background and Purpose Although cannabinoid CB2 receptor ligands have been widely characterized in recombinant systems in vitro, little pharmacological characterization has been performed in tissues natively expressing CB2 receptors. The aim of this study was to compare the pharmacology of CB2 receptor ligands in tissue natively expressing CB2 receptors (human, rat and mouse spleen) and hCB2-transfected CHO cells. Experimental Approach We tested the ability of well-known cannabinoid CB2 receptor ligands to stimulate or inhibit [35S]GTPγS binding to mouse, rat and human spleen membranes and to hCB2-transfected CHO cell membranes. cAMP assays were also performed in hCB2-CHO cells. Key Results The data presented demonstrate that: (i) CP 55,940, WIN 55,212-2 and JWH 133 behave as CB2 receptor full agonists both in spleen and hCB2-CHO cells, in both [35S]GTPγS and cAMP assays; (ii) JWH 015 behaves as a low-efficacy agonist in spleen as well as in hCB2-CHO cells when tested in the [35S]GTPγS assay, while it displays full agonism when tested in the cAMP assay using hCB2-CHO cells; (iii) (R)-AM 1241 and GW 405833 behave as agonists in the [35S]GTPγS assay using spleen, instead it behaves as a low-efficacy inverse agonist in hCB2-CHO cells; and (iv) SR 144528, AM 630 and JTE 907 behave as CB2 receptor inverse agonists in all the tissues. Conclusion and Implications Our results demonstrate that CB2 receptor ligands can display differential pharmacology when assays are conducted in tissues that natively express CB2 receptors and imply that conclusions from recombinant CB2 receptors should be treated with caution. PMID:23711022

Expression of bitter taste receptors of the T2R family in the gastrointestinal tract and enteroendocrine STC-1 cells.

PubMed

Wu, S Vincent; Rozengurt, Nora; Yang, Moon; Young, Steven H; Sinnett-Smith, James; Rozengurt, Enrique

2002-02-19

Although a role for the gastric and intestinal mucosa in molecular sensing has been known for decades, the initial molecular recognition events that sense the chemical composition of the luminal contents has remained elusive. Here we identified putative taste receptor gene transcripts in the gastrointestinal tract. Our results, using reverse transcriptase-PCR, demonstrate the presence of transcripts corresponding to multiple members of the T2R family of bitter taste receptors in the antral and fundic gastric mucosa as well as in the lining of the duodenum. In addition, cDNA clones of T2R receptors were detected in a rat gastric endocrine cell cDNA library, suggesting that these receptors are expressed, at least partly, in enteroendocrine cells. Accordingly, expression of multiple T2R receptors also was found in STC-1 cells, an enteroendocrine cell line. The expression of alpha subunits of G proteins implicated in intracellular taste signal transduction, namely Galpha(gust), and Galpha(t)-(2), also was demonstrated in the gastrointestinal mucosa as well as in STC-1 cells, as revealed by reverse transcriptase-PCR and DNA sequencing, immunohistochemistry, and Western blotting. Furthermore, addition of compounds widely used in bitter taste signaling (e.g., denatonium, phenylthiocarbamide, 6-n-propil-2-thiouracil, and cycloheximide) to STC-1 cells promoted a rapid increase in intracellular Ca(2+) concentration. These results demonstrate the expression of bitter taste receptors of the T2R family in the mouse and rat gastrointestinal tract.

Expression of Angiotensin II Types 1 and 2 Receptors in Endometriotic Lesions.

PubMed

Nakao, Takehiro; Chishima, Fumihisa; Sugitani, Masahiko; Tsujimura, Ryusuke; Hayashi, Chuyu; Yamamoto, Tatsuo

2017-01-01

The aim of this study was to evaluate the gene and protein expression of angiotensin type (AT) 1, AT2 receptors in endometriotic lesions and its relation to prostaglandin (PG) synthases. Endometriosis samples were obtained from 32 patients with endometriotic cysts. Endometrial tissues were obtained during operations for benign gynecological conditions. The expression of the AT1 and AT2 receptor mRNA and that of PG-endoperoxide synthase 2 and microsomal PGE2 synthase-1 (mPGES-1) was examined by quantitative RT-PCR. Immunohistochemical staining was performed for these receptors. AT1 and AT2 receptor proteins were mostly located in endometrial glandular epithelium and some stromal cells. Immunoreactivity of the receptor proteins was observed in both the eutopic endometrium and endometriotic lesions. The AT1/AT2 ratio in endometriotic cysts (median 7.29, range 1.88-187.60) was significantly increased compared with that in the eutopic endometrium in the proliferative-phase in controls (median 1.01, range 0.37-2.09, p < 0.001). There was a relationship between the AT1 mRNA expression and that of mPGES-1 mRNA in the endometriotic cysts (r = 0.394089, p < 0.05). There was a significant relationship between the mRNA expression of the AT2 receptor and that of mPGES-1 in eutopic endometrium of non-endometriotic control (r = 0.610714, p < 0.05). Renin-angiotensin system may play an important role in the pathophysiology of endometriosis. © 2016 S. Karger AG, Basel.

Arrestin–dependent but G–protein coupled receptor kinase–independent uncoupling of D2–dopamine receptors

PubMed Central

Celver, Jeremy; Sharma, Meenakshi; Thanawala, Vaidehi; Octeau, J. Christopher; Kovoor, Abraham

2016-01-01

We reconstituted D2 like dopamine receptor (D2R) and the delta opioid receptor (DOR) coupling to G-protein gated inwardly rectifying potassium channels (Kir3) and directly compared the effects of co-expression of G-protein coupled receptor kinase (GRK) and arrestin on agonist-dependent desensitization of the receptor response. We found, as described previously, that co-expression of a GRK and an arrestin synergistically increased the rate of agonist-dependent desensitization of DOR. In contrast, only arrestin expression was required to produce desensitization of D2R responses. Furthermore, arrestin-dependent GRK-independent desensitization of D2R-Kir3 coupling could be transferred to DOR by substituting the third cytoplasmic loop of DOR with that of D2R. The arrestin-dependent GRK-independent desensitization of D2R desensitization was inhibited by staurosporine treatment, and blocked by alanine substitution of putative protein kinase C phosphorylation sites in the third cytoplasmic loop of D2R. Finally, the D2R construct in which putative protein kinase C phosphorylation sites were mutated did not undergo significant agonist-dependent desensitization even after GRK co-expression, suggesting that GRK phosphorylation of D2R does not play an important role in uncoupling of the receptor. PMID:23815307

Arrestin-dependent but G-protein coupled receptor kinase-independent uncoupling of D2-dopamine receptors.

PubMed

Celver, Jeremy; Sharma, Meenakshi; Thanawala, Vaidehi; Christopher Octeau, J; Kovoor, Abraham

2013-10-01

We reconstituted D2 like dopamine receptor (D2R) and the delta opioid receptor (DOR) coupling to G-protein gated inwardly rectifying potassium channels (K(ir)3) and directly compared the effects of co-expression of G-protein coupled receptor kinase (GRK) and arrestin on agonist-dependent desensitization of the receptor response. We found, as described previously, that co-expression of a GRK and an arrestin synergistically increased the rate of agonist-dependent desensitization of DOR. In contrast, only arrestin expression was required to produce desensitization of D2R responses. Furthermore, arrestin-dependent GRK-independent desensitization of D2R-K(ir)3 coupling could be transferred to DOR by substituting the third cytoplasmic loop of DOR with that of D2R. The arrestin-dependent GRK-independent desensitization of D2R desensitization was inhibited by staurosporine treatment, and blocked by alanine substitution of putative protein kinase C phosphorylation sites in the third cytoplasmic loop of D2R. Finally, the D2R construct in which putative protein kinase C phosphorylation sites were mutated did not undergo significant agonist-dependent desensitization even after GRK co-expression, suggesting that GRK phosphorylation of D2R does not play an important role in uncoupling of the receptor. © 2013 International Society for Neurochemistry.

Bromocriptine modulates the expression of PTHrP receptor, Indian hedgehog, and Runx2 proteins in the growth plate of lactating rats.

PubMed

Wongdee, Kannikar; Thonapan, Natchayaporn; Saengamnart, Wasana; Krishnamra, Nateetip; Charoenphandhu, Narattaphol

2013-09-01

In lactating rats, the endochondral bone growth is markedly enhanced, leading to the lengthening of long bone. This lactation-induced bone elongation could be abolished by a dopaminergic D2 receptor agonist bromocriptine, but how bromocriptine altered the expression of major chondroregulatory proteins in the growth plate cartilage was elusive. Here, we performed a quantitative immunohistochemical analysis to determine the expression of various peptides and transcription factors known to control the growth plate chondrocyte proliferation and differentiation [i.e., parathyroid hormone-related protein (PTHrP), PTHrP receptor, Indian hedgehog (Ihh), and runt-related transcription factor 2 (Runx2)], in bromocriptine-treated lactating rats. The results showed that bromocriptine markedly increased Ihh expression in hypertrophic chondrocytes during early and mid-lactation, while the expression of PTHrP receptor, but not its ligand PTHrP, was upregulated in the proliferative and hypertrophic zones during mid and late lactation. In contrast, the expression of Runx2, an important transcription factor for chondrocyte differentiation, was suppressed in the hypertrophic chondrocytes of bromocriptine-treated rats. In conclusion, bromocriptine increased Ihh and PTHrP receptor expressions and decreased Runx2 expression, which might, in turn, enhance chondrocyte proliferation and delay chondrocyte hypertrophy, thereby slowing down endochondral bone growth. This finding could explain how bromocriptine compromised the lactation-induced bone elongation.

NKG2A inhibits NKG2C effector functions of γδ T cells: implications in health and disease.

PubMed

Angelini, Daniela F; Zambello, Renato; Galandrini, Ricciarda; Diamantini, Adamo; Placido, Roberta; Micucci, Federica; Poccia, Fabrizio; Semenzato, Giuseppe; Borsellino, Giovanna; Santoni, Angela; Battistini, Luca

2011-01-01

The CD94/NKG2 complex is expressed on T and NK lymphocytes. CD94 molecules covalently associate to activating or inhibitory NKG2 molecules, and their expression finely tunes cell responses. Human γδ T cells express several NKRs. Expression of these receptors is confined to the cytolytic Vδ2 subset, which coexpresses the FcγRIII CD16 and CD45RA and has been defined as Vγ9Vδ2 T(EMRA) cells. We show that the CD94/NKG2C complex, associated with KARAP/DAP12, is fully functional in γδ T cells, as determined by measuring IFN-γ production, T cell proliferation, and cytolytic activity by γδ lymphocytes. In contrast, NKG2A expression was found on all γδ T cell memory subsets, suggesting a crucial role of the inhibitory signal provided by this receptor on γδ T cell responses. Moreover, we found Vγ9Vδ2 T(EMRA), NK, and CD8+ αβ T cells coexpressing NKG2A and NKG2C receptors. Functional experiments showed that the inhibitory signal mediated by the NKG2A receptor prevails when double-positive cells are activated. Finally, NKG2A expression on γδ LDGL correlates with asymptomatic pathology, even in the presence of NKG2C coexpression, whereas in symptomatic patients affected by severe disease, the inhibitory NKG2A receptor is absent, and a variety of activatory NKRs was found. We propose that the silent behavior of γδ cells in LDGL patients is a result of effective inhibitory HLA class I receptors.

Human Freud-2/CC2D1B: a novel repressor of postsynaptic serotonin-1A receptor expression.

PubMed

Hadjighassem, Mahmoud R; Austin, Mark C; Szewczyk, Bernadeta; Daigle, Mireille; Stockmeier, Craig A; Albert, Paul R

2009-08-01

Altered expression of serotonin-1A (5-HT1A) receptors, both presynaptic in the raphe nuclei and post-synaptic in limbic and cortical target areas, has been implicated in mood disorders such as major depression and anxiety. Within the 5-HT1A receptor gene, a powerful dual repressor element (DRE) is regulated by two protein complexes: Freud-1/CC2D1A and a second, unknown repressor. Here we identify human Freud-2/CC2D1B, a Freud-1 homologue, as the second repressor. Freud-2 distribution was examined with Northern and Western blot, reverse transcriptase polymerase chain reaction, and immunohistochemistry/immunofluorescence; Freud-2 function was examined by electrophoretic mobility shift, reporter assay, and Western blot. Freud-2 RNA was widely distributed in brain and peripheral tissues. Freud-2 protein was enriched in the nuclear fraction of human prefrontal cortex and hippocampus but was weakly expressed in the dorsal raphe nucleus. Freud-2 immunostaining was co-localized with 5-HT1A receptors, neuronal and glial markers. In prefrontal cortex, Freud-2 was expressed at similar levels in control and depressed male subjects. Recombinant hFreud-2 protein bound specifically to 5' or 3' human DRE adjacent to the Freud-1 site. Human Freud-2 showed strong repressor activity at the human 5-HT1A or heterologous promoter in human HEK-293 5-HT1A-negative cells and neuronal SK-N-SH cells, a model of postsynaptic 5-HT1A receptor-positive cells. Furthermore, small interfering RNA knockdown of endogenous hFreud-2 expression de-repressed 5-HT1A promoter activity and increased levels of 5-HT1A receptor protein in SK-N-SH cells. Human Freud-2 binds to the 5-HT1A DRE and represses the human 5-HT1A receptor gene to regulate its expression in non-serotonergic cells and neurons.

Lubiprostone Activates CFTR, but not ClC-2, via the Prostaglandin Receptor (EP4)

PubMed Central

Norimatsu, Yohei; Moran, Aurelia R.; MacDonald, Kelvin D.

2012-01-01

The goal of this study was to determine the mechanism of lubiprostone activation of epithelial chloride transport. Lubiprostone is a bicyclic fatty acid approved for the treatment of constipation [1]. There is uncertainty, however, as to how lubiprostone increases epithelial chloride transport. Direct stimulation of ClC-2 and CFTR chloride channels as well as stimulation of these channels via the EP4 receptor has been described [2; 3; 4; 5]. To better define this mechanism, two-electrode voltage clamp was used to assay Xenopus oocytes expressing ClC-2, with or without co-expression of the EP4 receptor or β adrenergic receptor (βAR), for changes in conductance elicited by lubiprostone. Oocytes co-expressing CFTR and either βAR or the EP4 receptor were also studied. In oocytes co-expressing ClC-2 and βAR conductance was stimulated by hyperpolarization and acidic pH (pH=6), but there was no response to the β adrenergic agonist, isoproterenol. Oocytes expressing ClC-2 only or co-expressing ClC-2 and EP4 did not respond to the presence of 0.1, 1, or 10 µM lubiprostone in the superperfusate. Oocytes co-expressing CFTR and βAR did not respond to hyperpolarization, acidic pH, or 1µM lubiprostone. However, conductance was elevated by isoproterenol and inhibited by CFTRinh172. Co-expression of CFTR and EP4 resulted in lubiprostone-stimulated conductance, which was also sensitive to CFTRinh172. The EC50 for lubiprostone mediated CFTR activation was ~ 10 nM. These results demonstrate no direct action of lubiprostone on either ClC-2 or CFTR channels expressed in oocytes. However, the results confirm that CFTR can be activated by lubiprostone via the EP4 receptor in oocytes. PMID:22960173

Estrogen receptor-α, progesterone receptor, and c-erbB/HER-family receptor mRNA detection and phenotype analysis in spontaneous canine models of breast cancer

PubMed Central

Kabir, Farruk M. Lutful; DeInnocentes, Patricia; Agarwal, Payal; Mill, Christopher P.; Riese, David J.

2017-01-01

Well characterized, stable, p16-defective canine mammary cancer (CMT) cell lines and normal canine mammary epithelial cells were used to investigate expression of the major breast cancer-specific hormone receptors estrogen receptor alpha (ER1) and progesterone receptor (PR) as well as luminal epithelial-specific proto-oncogenes encoding c-erbB-1 (epidermal growth factor receptor/EGFr), c-erbB-2/HER2, c-erbB-3, and c-erbB-4 receptors. The investigation developed and validated quantitative reverse transcriptase polymerase chain reaction assays for each transcript to provide rapid assessment of breast cancer phenotypes for canine cancers, based on ER1, PR, and c-erbB-2/HER2 expressions, similar to those in human disease. Roles for relatively underexplored c-erbB-3 and c-erbB-4 receptor expressions in each of these breast cancer phenotypes were also evaluated. Each quantitative assay was validated by assessment of amplicon size and DNA sequencing following amplification. Differential expression of ER1, PR, and c-erbB-2 in CMT cell lines clearly defined distinct human-like breast cancer phenotypes for a selection of CMT-derived cell lines. Expression profiles for EGFr family genes c-erbB-3 and c-erbB-4 in CMT models also provided an enriched classification of canine breast cancer identifying new extended phenotypes beyond the conventional luminal-basal characterization used in human breast cancer. PMID:27515268

Activation of Adenosine A2A Receptors Inhibits Neutrophil Transuroepithelial Migration ▿

PubMed Central

Säve, Susanne; Mohlin, Camilla; Vumma, Ravi; Persson, Katarina

2011-01-01

Adenosine has been identified as a significant inhibitor of inflammation by acting on adenosine A2A receptors. In this study, we examined the role of adenosine and A2A receptors in the transmigration of human neutrophils across an in vitro model of the transitional bladder urothelium. Human uroepithelial cells (UROtsa) were grown on transwell inserts; uropathogenic Escherichia coli (UPEC) and neutrophils were added to the transwell system; and the number of migrating neutrophils was evaluated. Reverse transcription-PCR (RT-PCR), immunohistochemistry, and flow cytometry were used to investigate the expression of adenosine receptors, the epithelial adhesion molecule ICAM-1, and the neutrophil integrin CD11b. Levels of proinflammatory interleukin-8 (IL-8) and phosphorylated IκBα were measured by enzyme-linked immunosorbent assays (ELISA) and Luminex assays, respectively. The neutrophils expressed all four adenosine receptor subtypes (A1, A2A, A2B, and A3 receptors), but A3 receptors were not expressed by UROtsa cells. UPEC stimulated neutrophil transuroepithelial migration, which was significantly decreased in response to the specific A2A receptor agonist CGS 21680. The inhibitory effect of CGS 21680 on neutrophil migration was reversed by the A2A receptor antagonist SCH 58261. The production of chemotactic IL-8 and the expression of the adhesion molecule ICAM-1 or CD11b were not significantly affected by CGS 21680. However, a significant decrease in the level of phosporylated IκBα was revealed in response to CGS 21680. In conclusion, UPEC infection in vitro evoked neutrophil migration through a multilayered human uroepithelium. The UPEC-evoked neutrophil transmigration decreased in response to A2A receptor activation, possibly through inhibition of NF-κB signaling pathways. PMID:21646447

Differential S1P Receptor Profiles on M1- and M2-Polarized Macrophages Affect Macrophage Cytokine Production and Migration.

PubMed

Müller, Jan; von Bernstorff, Wolfram; Heidecke, Claus-Dieter; Schulze, Tobias

2017-01-01

Introduction . Macrophages are key players in complex biological processes. In response to environmental signals, macrophages undergo polarization towards a proinflammatory (M1) or anti-inflammatory (M2) phenotype. Sphingosine 1-phosphate (S1P) is a bioactive lysophospholipid that acts via 5 G-protein coupled receptors (S1P 1-5 ) in order to influence a broad spectrum of biological processes. This study assesses S1P receptor expression on macrophages before and after M1 and M2 polarization and performs a comparative analysis of S1P signalling in the two activational states of macrophages. Methods . Bone marrow derived macrophages (BMDM) from C57 BL/6 mice were cultured under either M1- or M2-polarizing conditions. S1P-receptor expression was determined by quantitative RT-PCR. Influence of S1P on macrophage activation, migration, phagocytosis, and cytokine secretion was assessed in vitro. Results . All 5 S1P receptor subclasses were expressed in macrophages. Culture under both M1- and M2-polarizing conditions led to significant downregulation of S1P 1 . In contrast, M1-polarized macrophages significantly downregulated S1P 4 . The expression of the remaining three S1P receptors did not change. S1P increased expression of iNOS under M2-polarizing conditions. Furthermore, S1P induced chemotaxis in M1 macrophages and changed cytokine production in M2 macrophages. Phagocytosis was not affected by S1P-signalling. Discussion . The expression of different specific S1P receptor profiles may provide a possibility to selectively influence M1- or M2-polarized macrophages.

Prostaglandin E2 suppresses beta1-integrin expression via E-prostanoid receptor in human monocytes/macrophages.

PubMed

Hasegawa, Shunji; Ichiyama, Takashi; Kohno, Fumitaka; Korenaga, Yuno; Ohsaki, Ayami; Hirano, Reiji; Haneda, Yasuhiro; Fukano, Reiji; Furukawa, Susumu

2010-01-01

Beta1-integrins mediate cell attachment to different extracellular matrix proteins, intracellular proteins, and intercellular adhesions. Recently, it has been reported that prostaglandin E2 (PGE2) has anti-inflammatory properties such as inhibition of the expression of adhesion molecules or production of chemokines. However, the effect of PGE2 on the expression of beta1-integrin remains unknown. In this study, we investigated the effects of PGE2 on the expression of beta1-integrin in the human monocytic cell line THP-1 and in CD14+ monocytes/macrophages in human peripheral blood. For this, we examined the role of four subtypes of PGE2 receptors and E-prostanoid (EP) receptors on PGE2-mediated inhibition. We found that PGE2 significantly inhibited the expression of beta1-integrin, mainly through EP4 receptors in THP-1 cells and CD14+ monocytes/macrophages in human peripheral blood. We suggest that PGE2 has anti-inflammatory effects, leading to the inhibited expression of beta1-integrin in human monocytes/macrophages, and that the EP4 receptor may play an important role in PGE2-mediated inhibition. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Effects of acute versus repeated cocaine exposure on the expression of endocannabinoid signaling-related proteins in the mouse cerebellum.

PubMed

Palomino, Ana; Pavón, Francisco-Javier; Blanco-Calvo, Eduardo; Serrano, Antonia; Arrabal, Sergio; Rivera, Patricia; Alén, Francisco; Vargas, Antonio; Bilbao, Ainhoa; Rubio, Leticia; Rodríguez de Fonseca, Fernando; Suárez, Juan

2014-01-01

Growing awareness of cerebellar involvement in addiction is based on the cerebellum's intermediary position between motor and reward, potentially acting as an interface between motivational and cognitive functions. Here, we examined the impact of acute and repeated cocaine exposure on the two main signaling systems in the mouse cerebellum: the endocannabinoid (eCB) and glutamate systems. To this end, we investigated whether eCB signaling-related gene and protein expression {cannabinoid receptor type 1 receptors and enzymes that produce [diacylglycerol lipase alpha/beta (DAGLα/β) and N-acyl phosphatidylethanolamine phospholipase D (NAPE-PLD)] and degrade [monoacylglycerol lipase (MAGL) and fatty acid amino hydrolase (FAAH)] eCB} were altered. In addition, we analyzed the gene expression of relevant components of the glutamate signaling system [glutamate synthesizing enzymes liver-type glutaminase isoform (LGA) and kidney-type glutaminase isoform (KGA), metabotropic glutamatergic receptor (mGluR3/5), NMDA-ionotropic glutamatergic receptor (NR1/2A/2B/2C) and AMPA-ionotropic receptor subunits (GluR1/2/3/4)] and the gene expression of tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine biosynthesis, because noradrenergic terminals innervate the cerebellar cortex. Results indicated that acute cocaine exposure decreased DAGLα expression, suggesting a down-regulation of 2-arachidonylglycerol (2-AG) production, as well as gene expression of TH, KGA, mGluR3 and all ionotropic receptor subunits analyzed in the cerebellum. The acquisition of conditioned locomotion and sensitization after repeated cocaine exposure were associated with an increased NAPE-PLD/FAAH ratio, suggesting enhanced anandamide production, and a decreased DAGLβ/MAGL ratio, suggesting decreased 2-AG generation. Repeated cocaine also increased LGA gene expression but had no effect on glutamate receptors. These findings indicate that acute cocaine modulates the expression of the eCB and glutamate systems. Repeated cocaine results in normalization of glutamate receptor expression, although sustained changes in eCB is observed. We suggest that cocaine-induced alterations to cerebellar eCB should be considered when analyzing the adaptations imposed by psychostimulants that lead to addiction.

Effects of acute versus repeated cocaine exposure on the expression of endocannabinoid signaling-related proteins in the mouse cerebellum

PubMed Central

Palomino, Ana; Pavón, Francisco-Javier; Blanco-Calvo, Eduardo; Serrano, Antonia; Arrabal, Sergio; Rivera, Patricia; Alén, Francisco; Vargas, Antonio; Bilbao, Ainhoa; Rubio, Leticia; Rodríguez de Fonseca, Fernando; Suárez, Juan

2014-01-01

Growing awareness of cerebellar involvement in addiction is based on the cerebellum’s intermediary position between motor and reward, potentially acting as an interface between motivational and cognitive functions. Here, we examined the impact of acute and repeated cocaine exposure on the two main signaling systems in the mouse cerebellum: the endocannabinoid (eCB) and glutamate systems. To this end, we investigated whether eCB signaling-related gene and protein expression {cannabinoid receptor type 1 receptors and enzymes that produce [diacylglycerol lipase alpha/beta (DAGLα/β) and N-acyl phosphatidylethanolamine phospholipase D (NAPE-PLD)] and degrade [monoacylglycerol lipase (MAGL) and fatty acid amino hydrolase (FAAH)] eCB} were altered. In addition, we analyzed the gene expression of relevant components of the glutamate signaling system [glutamate synthesizing enzymes liver-type glutaminase isoform (LGA) and kidney-type glutaminase isoform (KGA), metabotropic glutamatergic receptor (mGluR3/5), NMDA-ionotropic glutamatergic receptor (NR1/2A/2B/2C) and AMPA-ionotropic receptor subunits (GluR1/2/3/4)] and the gene expression of tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine biosynthesis, because noradrenergic terminals innervate the cerebellar cortex. Results indicated that acute cocaine exposure decreased DAGLα expression, suggesting a down-regulation of 2-arachidonylglycerol (2-AG) production, as well as gene expression of TH, KGA, mGluR3 and all ionotropic receptor subunits analyzed in the cerebellum. The acquisition of conditioned locomotion and sensitization after repeated cocaine exposure were associated with an increased NAPE-PLD/FAAH ratio, suggesting enhanced anandamide production, and a decreased DAGLβ/MAGL ratio, suggesting decreased 2-AG generation. Repeated cocaine also increased LGA gene expression but had no effect on glutamate receptors. These findings indicate that acute cocaine modulates the expression of the eCB and glutamate systems. Repeated cocaine results in normalization of glutamate receptor expression, although sustained changes in eCB is observed. We suggest that cocaine-induced alterations to cerebellar eCB should be considered when analyzing the adaptations imposed by psychostimulants that lead to addiction. PMID:24634647

Tobacco smoke induces epithelial barrier dysfunction via receptor EphA2 signaling.

PubMed

Nasreen, Najmunnisa; Khodayari, Nazli; Sriram, Peruvemba S; Patel, Jawaharlal; Mohammed, Kamal A

2014-06-15

Erythropoietin-producing human hepatocellular carcinoma (Eph) receptors are the largest family of receptor tyrosine kinases (RTKs) that mediate various cellular and developmental processes. The degrees of expression of these key molecules control the cell-cell interactions. Although the role of Eph receptors and their ligand Ephrins is well studied in developmental processes, their function in tobacco smoke (TS)-induced epithelial barrier dysfunction is unknown. We hypothesized that TS may induce permeability in bronchial airway epithelial cell (BAEpC) monolayer by modulating receptor EphA2 expression, actin cytoskeleton, adherens junction, and focal adhesion proteins. Here we report that in BAEpCs, acute TS exposure significantly upregulated EphA2 and EphrinA1 expression, disrupted the actin filaments, decreased E-cadherin expression, and increased protein permeability, whereas the focal adhesion protein paxillin was unaffected. Silencing the receptor EphA2 expression with silencing interference RNA (siRNA) significantly attenuated TS-induced hyperpermeability in BAEpCs. In addition, when BAEpC monolayer was transfected with EphA2-expressing plasmid and treated with recombinant EphrinA1, the transepithelial electrical resistance decreased significantly. Furthermore, TS downregulated E-cadherin expression and induced hyperpermeability across BAEpC monolayer in a Erk1/Erk2, p38, and JNK MAPK-dependent manner. TS induced hyperpermeability in BAEpC monolayer by targeting cell-cell adhesions, and interestingly cell-matrix adhesions were unaffected. The present data suggest that TS causes significant damage to the BAEpCs via induction of EphA2 and downregulation of E-cadherin. Induction of EphA2 in the BAEpCs exposed to TS may be an important signaling event in the pathogenesis of TS-induced epithelial injury.

Expression and function of the metabotropic purinergic P2Y receptor family in experimental seizure models and patients with drug-refractory epilepsy.

PubMed

Alves, Mariana; Gomez-Villafuertes, Rosa; Delanty, Norman; Farrell, Michael A; O'Brien, Donncha F; Miras-Portugal, Maria Teresa; Hernandez, Miguel Diaz; Henshall, David C; Engel, Tobias

2017-09-01

ATP is released into the extracellular space during pathologic processes including increased neuronal firing. Once released, ATP acts on P2 receptors including ionotropic P2X and metabotropic P2Y receptors, resulting in changes to glial function and neuronal network excitability. Evidence suggests an involvement of P2Y receptors in the pathogenesis of epilepsy, but there has been no systematic effort to characterize the expression and function of the P2Y receptor family during seizures and in experimental and human epilepsy. Status epilepticus was induced using either intra-amygdala kainic acid or pilocarpine to characterize the acute- and long-term changes in hippocampal P2Y expression. P2Y expression was also investigated in brain tissue from patients with temporal lobe epilepsy. Finally, we analyzed the effects of two specific P2Y agonists, ADP and UTP, on seizure severity and seizure-induced cell death. Both intra-amygdala kainic acid and pilocarpine-induced status epilepticus increased the transcription of the uracil-sensitive P2Y receptors P2ry 2 , P2ry 4 , and P2ry 6 and decreased the transcription of the adenine-sensitive P2Y receptors P2ry 1 , P2ry 12 , P2ry 13 . Protein levels of P2Y 1 , P2Y 2 , P2Y 4 , and P2Y 6 were increased after status epilepticus, whereas P2Y 12 expression was decreased. In the chronic phase, P2ry 1 , P2ry 2 , and P2ry 6 transcription and P2Y 1 , P2Y 2 , and P2Y 12 protein levels were increased with no changes for the other P2Y receptors. In hippocampal samples from patients with temporal lobe epilepsy, P2Y 1 and P2Y 2 protein expression was increased, whereas P2Y 13 levels were lower. Demonstrating a functional contribution of P2Y receptors to seizures, central injection of ADP exacerbated seizure severity, whereas treatment with UTP decreased seizure severity during status epilepticus in mice. The present study is the first to establish the specific hippocampal expression profile and function of the P2Y receptor family after experimental status epilepticus and in human temporal lobe epilepsy and offers potential new targets for seizure control and disease modification. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

Distinct functional characteristics of levocabastine sensitive rat neurotensin NT2 receptor expressed in Chinese hamster ovary cells.

PubMed

Yamada, M; Yamada, M; Lombet, A; Forgez, P; Rostène, W

1998-01-01

Neurotensin has been shown to produce pharmacological effects both in brain and periphery. Several of these effects are mediated by a high-affinity neurotensin NT1 receptor. On the other hand, a low-affinity levocabastine-sensitive neurotensin NT2 receptor was molecularly cloned from rodent brain recently. In this study, in contrast to NT1 receptor, levocabastine (a histamine H1 receptor antagonist) and SR48692 (an antagonist for NT1 receptor) strongly stimulated intracellular Ca2+ mobilization in transfected Chinese hamster ovary cells expressing rat NT2 receptor, thus acting as potent NT2 receptor. Furthermore, despite of their affinities for NT2 receptor, the Ca2+ responses to potent NT1 agonists, neurotensin or JMV449 ([Lys8-(CH2NH)-Lys9]Pro-Tyr-Ile-Leu, a peptidase resistant analogue of neurotensin) were much smaller than that observed with SR48692. These findings suggest that NT1 and NT2 receptors present distinct functional characteristics and that SR48692 may act as a potent agonist for NT2 receptor.

ASGR1 and ASGR2, the Genes that Encode the Asialoglycoprotein Receptor (Ashwell Receptor), Are Expressed in Peripheral Blood Monocytes and Show Interindividual Differences in Transcript Profile

PubMed Central

Harris, Rebecca Louise; van den Berg, Carmen Wilma; Bowen, Derrick John

2012-01-01

Background. The asialoglycoprotein receptor (ASGPR) is a hepatic receptor that mediates removal of potentially hazardous glycoconjugates from blood in health and disease. The receptor comprises two proteins, asialoglycoprotein receptor 1 and 2 (ASGR1 and ASGR2), encoded by the genes ASGR1 and ASGR2. Design and Methods. Using reverse transcription amplification (RT-PCR), expression of ASGR1 and ASGR2 was investigated in human peripheral blood monocytes. Results. Monocytes were found to express ASGR1 and ASGR2 transcripts. Correctly spliced transcript variants encoding different isoforms of ASGR1 and ASGR2 were present in monocytes. The profile of transcript variants from both ASGR1 and ASGR2 differed among individuals. Transcript expression levels were compared with the hepatocyte cell line HepG2 which produces high levels of ASGPR. Monocyte transcripts were 4 to 6 orders of magnitude less than in HepG2 but nonetheless readily detectable using standard RT-PCR. The monocyte cell line THP1 gave similar results to monocytes harvested from peripheral blood, indicating it may provide a suitable model system for studying ASGPR function in this cell type. Conclusions. Monocytes transcribe and correctly process transcripts encoding the constituent proteins of the ASGPR. Monocytes may therefore represent a mobile pool of the receptor, capable of reaching sites remote from the liver. PMID:22919488

Overexpression of androgen receptor and forkhead-box A1 protein in apocrine breast carcinoma.

PubMed

Sasahara, Manami; Matsui, Akira; Ichimura, Yoshiko; Hirakata, Yuuko; Murata, Yuuya; Marui, Eiji

2014-03-01

Apocrine breast carcinoma often lacks estrogen receptor (ER), progesterone receptor (PgR), and human epidermal growth factor receptor type-2 (HER2) expression. Accordingly, development of a new treatment strategy is important for this type of cancer. The growth stimulus through the androgen receptor (AR) can be a candidate for targeted treatment. Therefore, we examined the factors related to AR transcription. We immunohistochemically evaluated 54 apocrine cancer lesions for ER, PgR, AR, HER2, Ki-67, forkhead-box protein A1 (FOXA1), and prostate-specific antigen (PSA) expression. ER, PgR, and HER2 were expressed at a low level, thus 44 out of 54 (81.4%) cases were of triple-negative breast cancer. AR, PSA and FOXA1 were expressed in 100% (54/54), 48% (26/54) and 93% (50/54) of cases, respectively. Most of apocrine breast carcinomas were immunohistochemically-positive for AR and FOXA1. Anti-androgenic therapies can potentially serve as a cancer-targeting therapy for apocrine breast carcinoma.

Cloning and functional analysis of P2X1b, a new variant in rat optic nerve that regulates the P2X1 receptor in a use-dependent manner.

PubMed

Rangel-Yescas, Gisela E; Vazquez-Cuevas, Francisco G; Garay, Edith; Arellano, Rogelio O

2012-01-01

P2X receptors are trimeric, ATP-gated cation channels. In mammals seven P2X subtypes have been reported (P2X1-P2X7), as well as several variants generated by alternative splicing. Variants confer to the homomeric or heteromeric channels distinct functional and/or pharmacological properties. Molecular biology, biochemical, and functional analysis by electrophysiological methods were used to identify and study a new variant of the P2X1 receptor named P2X1b. This new variant, identified in rat optic nerve, was also expressed in other tissues. P2X1b receptors lack amino acids 182 to 208 of native P2X1, a region that includes residues that are highly conserved among distinct P2X receptors. When expressed in Xenopus oocytes, P2X1b was not functional as a homomer; however, when co-expressed with P2X1, it downregulated the electrical response generated by ATP compared with that of oocytes expressing P2X1 alone, and it seemed to form heteromeric channels with a modestly enhanced ATP potency. A decrease in responses to ATP in oocytes co-expressing different ratios of P2X1b to P2X1 was completely eliminated by overnight pretreatment with apyrase. Thus, it is suggested that P2X1b regulates, through a use-dependent mechanism, the availability, in the plasma membrane, of receptor channels that can be operated by ATP.

The neuronal Ca(2+) -binding protein 2 (NECAB2) interacts with the adenosine A(2A) receptor and modulates the cell surface expression and function of the receptor.

PubMed

Canela, Laia; Luján, Rafael; Lluís, Carme; Burgueño, Javier; Mallol, Josefa; Canela, Enric I; Franco, Rafael; Ciruela, Francisco

2007-09-01

Heptaspanning membrane also known as G protein-coupled receptors (GPCR) do interact with a variety of intracellular proteins whose function is regulate receptor traffic and/or signaling. Using a yeast two-hybrid screen, NECAB2, a neuronal calcium binding protein, was identified as a binding partner for the adenosine A(2A) receptor (A(2A)R) interacting with its C-terminal domain. Co-localization, co-immunoprecipitation and pull-down experiments showed a close and specific interaction between A(2A)R and NECAB2 in both transfected HEK-293 cells and also in rat striatum. Immunoelectron microscopy detection of NECAB2 and A(2A)R in the rat striatopallidal structures indicated that both proteins are co-distributed in the same glutamatergic nerve terminals. The interaction of NECAB2 with A(2A)R modulated the cell surface expression, the ligand-dependent internalization and the receptor-mediated activation of the MAPK pathway. Overall, these results show that A(2A)R interacts with NECAB2 in striatal neurones co-expressing the two proteins and that the interaction is relevant for A(2A)R function.

Gene expression of ionotropic glutamate receptor subunits in the tectofugal pathway of the pigeon.

PubMed

Atoji, Y

2016-03-01

The tectofugal pathway in birds consists of four stations, the retina, optic tectum, rotundal nucleus, and entopallium, and it conveys visual information via three ascending pathways. These pathways consist of retino-tectal, tecto-rotundal and rotundo-entopallial cells, all of which are glutamatergic. The present study examined the localization of ionotropic glutamate receptors (iGluRs) to identify the target areas of glutamatergic projections in the tectofugal pathway in pigeons. Nine subunits of iGluRs were analyzed using in situ hybridization as follows: AMPA receptors (GluA1, GluA2, GluA3, and GluA4), kainate receptors (GluK1, GluK2, and GluK4), and NMDA receptors (GluN1 and GluN2A). Hybridization signals of subunits showed various intensities in different cells. In the optic tectum, a strong to moderate expression was observed in layer 10 (GluA2, GluA3, GluK4, and GluN1) and layer 13 (GluA2, GluK4, GluN1, and GluN2A). The rotundal nucleus intensely expressed GluA3, GluA4, GluK1, and GluK4. In the entopallium, an intense to moderate expression of GluK1 and GluK4, and a moderate to weak expression of AMPA and NMDA receptors were observed. Furthermore, the parvocellular and magnocellular parts of the isthmic nuclei showed a strong expression of GluA2, GluA3, GluK4, and GluN1. The present findings demonstrate the expression of iGluRs in glutamatergic projection targets of the tectofugal pathway in birds and suggest a diversity of iGluRs in the transmission of visual information. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Expression and localization of the AT1 and AT2 angiotensin II receptors and α1A and α1D adrenergic receptors in aorta of hypertensive and diabetic rats.

PubMed

Rodríguez, Jessica Edith; Romero-Nava, Rodrigo; Reséndiz-Albor, Aldo Arturo; Rosales-Cruz, Erika; Hong, Enrique; Huang, Fengyang; Villafaña, Santiago

2017-01-01

Hypertension and diabetes are multifactorial diseases that frequently coexist and exacerbate each another. During the development of diabetes, the impairment of noradrenergic and renin-angiotensin systems has been reported in the response mediated by α 1 -AR and AT 1 receptors. Although their participation in the development of cardiovascular complications is still controversial, some studies have found increased or diminished response to the vasoconstrictive effect of noradrenaline or angiotensin II in a time-dependent manner of diabetes. Thus, the aim of this work was to investigate the possible changes in the expression or localization of α 1 -AR (α 1A and α 1D ) and angiotensin II receptors (AT 1 and AT 2 ) in aorta of rats after 4 weeks of the onset of diabetes. In order to be able to examine the expression of these receptors, immunofluorescence procedure was performed in tunica intima and tunica media of histological sections of aorta. Fluorescence was detected by a confocal microscopy. Our results showed that the receptors are expressed in both tunics, where adrenergic receptors have a higher density in tunica intima and tunica media of SHR compared with WKY; meanwhile, the expression of angiotensin II receptors is not modified in both groups of rats. On the other hand, the results showed that diabetes produced an increase or a decrease in the expression of receptors that is not associated to a specific type of receptor, vascular region, or strain of rat. In conclusion, diabetes and hypertension modify the expression of the receptors in tunica intima and tunica media of aorta in a different way.

The Expression of Dectin-1, Irak1 and Rip2 During the Host Response to Aspergillus fumigatus.

PubMed

Liu, Jinguo; Yu, Lin; Chen, Cuicui; Zhou, Jian; Gong, Xin; Li, Dandan; Hou, Dongni; Song, Yuanlin; Shao, Changzhou

2018-04-01

C-type lectin receptors (CLRs), Toll-like receptors (TLRs), and Nod-like receptors (NLRs) have the ability to recognize Aspergillus fumigatus (A. fumigates) and induce innate immune response. Dectin-1 is a well-described CLR, while interleukin-1 receptor-associated kinase 1 (Irak1) and receptor-interacting protein 2 (Rip2) are pivotal adaptor proteins of TLRs and NLRs signaling pathways, respectively. Our primary aim is to elucidate whether Dectin-1 regulates the expression of Irak1 and Rip2, and confirm that CLRs, TLRs, and NLRs pathways act synergistically in response to A. fumigatus infection. Pulmonary infection mouse models were established. Myeloid cells were differentiated in cell culture and examined by inverted microscopy, flow cytometry, and scanning electron microscopy. The relative mRNA levels were determined by qRT-PCR. The protein expression levels were determined by immunohistochemistry and Western blot. The expression of Dectin-1, Irak1, Rip2, and phosphorylation level of nuclear factor (NF)-κB p65 were induced by conidia in immunocompetent mice, while their expression and phosphorylation level were inhibited in immunocompromised mice after the administration of conidia. Conidia increased the expression of Dectin-1, Irak1, and Rip2 in myeloid cells, while Dectin-1 silencing significantly reduced their expression. Our findings demonstrate that Dectin-1, Irak1, and Rip2 are involved in response to A. fumigatus infection. Dectin-1 modulates the expression of Irak1 and Rip2. Additionally, these three signaling pathways are interconnected, and CLRs pathway plays a dominant role against A. fumigatus invasion.

Identification of the functional interleukin-22 (IL-22) receptor complex: the IL-10R2 chain (IL-10Rbeta ) is a common chain of both the IL-10 and IL-22 (IL-10-related T cell-derived inducible factor, IL-TIF) receptor complexes.

PubMed

Kotenko, S V; Izotova, L S; Mirochnitchenko, O V; Esterova, E; Dickensheets, H; Donnelly, R P; Pestka, S

2001-01-26

Interleukin-10 (IL-10)-related T cell-derived inducible factor (IL-TIF; provisionally designated IL-22) is a cytokine with limited homology to IL-10. We report here the identification of a functional IL-TIF receptor complex that consists of two receptor chains, the orphan CRF2-9 and IL-10R2, the second chain of the IL-10 receptor complex. Expression of the CRF2-9 chain in monkey COS cells renders them sensitive to IL-TIF. However, in hamster cells both chains, CRF2-9 and IL-10R2, must be expressed to assemble the functional IL-TIF receptor complex. The CRF2-9 chain (or the IL-TIF-R1 chain) is responsible for Stat recruitment. Substitution of the CRF2-9 intracellular domain with the IFN-gammaR1 intracellular domain changes the pattern of IL-TIF-induced Stat activation. The CRF2-9 gene is expressed in normal liver and kidney, suggesting a possible role for IL-TIF in regulating gene expression in these tissues. Each chain, CRF2-9 and IL-10R2, is capable of binding IL-TIF independently and can be cross-linked to the radiolabeled IL-TIF. However, binding of IL-TIF to the receptor complex is greater than binding to either receptor chain alone. Sharing of the common IL-10R2 chain between the IL-10 and IL-TIF receptor complexes is the first such case for receptor complexes with chains belonging to the class II cytokine receptor family, establishing a novel paradigm for IL-10-related ligands similar to the shared use of the gamma common chain (gamma(c)) by several cytokines, including IL-2, IL-4, IL-7, IL-9, and IL-15.

Expression of the Grb2-related protein of the lymphoid system in B cell subsets enhances B cell antigen receptor signaling through mitogen-activated protein kinase pathways.

PubMed

Yankee, Thomas M; Solow, Sasha A; Draves, Kevin D; Clark, Edward A

2003-01-01

Adapter proteins play a critical role in regulating signals triggered by Ag receptor cross-linking. These small molecules link receptor proximal events with downstream signaling pathways. In this study, we explore the expression and function of the Grb2-related protein of the lymphoid system (GrpL)/Grb2-related adaptor downstream of Shc adapter protein in human B cells. GrpL is expressed in naive B cells and is down-regulated following B cell Ag receptor ligation. By contrast, germinal center and memory B cells express little or no GrpL. Using human B cell lines, we detected constitutive interactions between GrpL and B cell linker protein, Src homology (SH)2 domain-containing leukocyte protein of 76 kDa, hemopoietic progenitor kinase 1, and c-Cbl. The N-terminal SH3 domain of GrpL binds c-Cbl while the C-terminal SH3 domain binds B cell linker protein and SH2 domain-containing leukocyte protein of 76 kDa. Exogenous expression of GrpL in a GrpL-negative B cell line leads to enhanced Ag receptor-induced extracellular signal-related kinase and p38 mitogen-activated protein kinase phosphorylation. Thus, GrpL expression in human B cell subsets appears to regulate Ag receptor-mediated signaling events.

Genetic deletion of GPR52 enhances the locomotor-stimulating effect of an adenosine A2A receptor antagonist in mice: A potential role of GPR52 in the function of striatopallidal neurons.

PubMed

Nishiyama, Keiji; Suzuki, Hirobumi; Maruyama, Minoru; Yoshihara, Tomoki; Ohta, Hiroyuki

2017-09-01

G protein-coupled receptor 52 (GPR52) is largely co-expressed with dopamine D 2 receptor (DRD2) in the striatum and nucleus accumbens, and this expression pattern is similar to that of adenosine A 2A receptor (ADORA2A). GPR52 has been proposed as a therapeutic target for positive symptoms of schizophrenia, based on observations from pharmacological and transgenic mouse studies. However, the physiological role of GPR52 in dopaminergic functions in the basal ganglia remains unclear. Here, we used GPR52 knockout (KO) mice to examine the role of GPR52 in dopamine receptor-mediated and ADORA2A-mediated locomotor activity and dopamine receptor signaling. High expression of GPR52 protein in the striatum, nucleus accumbens, and lateral globus pallidus of wild type (WT) littermates was confirmed by immunohistochemical analysis. GPR52 KO and WT mice exhibited almost identical locomotor responses to the dopamine releaser methamphetamine and the N-methyl-d-aspartate antagonist MK-801. In contrast, the locomotor response to the ADORA2A antagonist istradefylline was significantly augmented in GPR52 KO mice compared to WT mice. Gene expression analysis revealed that striatal expression of DRD2, but not of dopamine D 1 receptor and ADORA2A, was significantly decreased in GPR52 KO mice. Moreover, a significant reduction in the mRNA expression of enkephalin, a marker of the activity of striatopallidal neurons, was observed in the striatum of GPR52 KO mice, suggesting that GPR52 deletion could enhance DRD2 signaling. Taken together, these results imply the physiological relevance of GPR52 in modulating the function of striatopallidal neurons, possibly by interaction of GPR52 with ADORA2A and DRD2. Copyright © 2017 Elsevier B.V. All rights reserved.

Underexpression of mineralocorticoid receptor in colorectal carcinomas and association with VEGFR-2 overexpression.

PubMed

Di Fabio, Francesco; Alvarado, Carlos; Majdan, Agnieszka; Gologan, Adrian; Voda, Linda; Mitmaker, Elliot; Beitel, Lenore K; Gordon, Philip H; Trifiro, Mark

2007-11-01

The human mineralocorticoid receptor (MR) is a steroid receptor widely expressed in colorectal mucosa. A significant role for the MR in the reduction of vascular endothelial growth factor receptor-2 (VEGFR-2) mRNA levels has been demonstrated in vitro. To evaluate a potential contribution of MR to colorectal carcinoma progression, we analyzed the expression of MR in relation to VEGFR-2. Fresh human colorectal cancer tissue and adjacent normal mucosa were harvested from 48 consecutive patients. MR and VEGFR-2 mRNA expression levels were determined by real-time reverse transcriptase-polymerase chain reaction and correlated with clinicopathological parameters. A decline of MR expression was observed in all carcinomas compared to normal mucosa. Expression of MR was a median of 11-fold lower in carcinoma compared to the normal mucosa, irrespective of the location, size, stage, and differentiation. MR was a median of 20-fold underexpressed in carcinomas with VEGFR-2 overexpression vs only 9-fold in carcinomas with VEGFR-2 underexpression (p = 0.035, Mann-Whitney test). These findings support the hypothesis that reduction of MR expression may be one of the early events involved in colorectal carcinoma progression. The inverse association between MR and VEGFR-2 expression in carcinoma suggests a potential tumor-suppressive function for MR.

Function and distribution of 5-HT2 receptors in the honeybee (Apis mellifera).

PubMed

Thamm, Markus; Rolke, Daniel; Jordan, Nadine; Balfanz, Sabine; Schiffer, Christian; Baumann, Arnd; Blenau, Wolfgang

2013-01-01

Serotonin plays a pivotal role in regulating and modulating physiological and behavioral processes in both vertebrates and invertebrates. In the honeybee (Apis mellifera), serotonin has been implicated in division of labor, visual processing, and learning processes. Here, we present the cloning, heterologous expression, and detailed functional and pharmacological characterization of two honeybee 5-HT2 receptors. Honeybee 5-HT2 receptor cDNAs were amplified from brain cDNA. Recombinant cell lines were established constitutively expressing receptor variants. Pharmacological properties of the receptors were investigated by Ca(2+) imaging experiments. Quantitative PCR was applied to explore the expression patterns of receptor mRNAs. The honeybee 5-HT2 receptor class consists of two subtypes, Am5-HT2α and Am5-HT2β. Each receptor gene also gives rise to alternatively spliced mRNAs that possibly code for truncated receptors. Only activation of the full-length receptors with serotonin caused an increase in the intracellular Ca(2+) concentration. The effect was mimicked by the agonists 5-methoxytryptamine and 8-OH-DPAT at low micromolar concentrations. Receptor activities were blocked by established 5-HT receptor antagonists such as clozapine, methiothepin, or mianserin. High transcript numbers were detected in exocrine glands suggesting that 5-HT2 receptors participate in secretory processes in the honeybee. This study marks the first molecular and pharmacological characterization of two 5-HT2 receptor subtypes in the same insect species. The results presented should facilitate further attempts to unravel central and peripheral effects of serotonin mediated by these receptors.

Function and Distribution of 5-HT2 Receptors in the Honeybee (Apis mellifera)

PubMed Central

Thamm, Markus; Rolke, Daniel; Jordan, Nadine; Balfanz, Sabine; Schiffer, Christian; Baumann, Arnd; Blenau, Wolfgang

2013-01-01

Background Serotonin plays a pivotal role in regulating and modulating physiological and behavioral processes in both vertebrates and invertebrates. In the honeybee (Apis mellifera), serotonin has been implicated in division of labor, visual processing, and learning processes. Here, we present the cloning, heterologous expression, and detailed functional and pharmacological characterization of two honeybee 5-HT2 receptors. Methods Honeybee 5-HT2 receptor cDNAs were amplified from brain cDNA. Recombinant cell lines were established constitutively expressing receptor variants. Pharmacological properties of the receptors were investigated by Ca2+ imaging experiments. Quantitative PCR was applied to explore the expression patterns of receptor mRNAs. Results The honeybee 5-HT2 receptor class consists of two subtypes, Am5-HT2α and Am5-HT2β. Each receptor gene also gives rise to alternatively spliced mRNAs that possibly code for truncated receptors. Only activation of the full-length receptors with serotonin caused an increase in the intracellular Ca2+ concentration. The effect was mimicked by the agonists 5-methoxytryptamine and 8-OH-DPAT at low micromolar concentrations. Receptor activities were blocked by established 5-HT receptor antagonists such as clozapine, methiothepin, or mianserin. High transcript numbers were detected in exocrine glands suggesting that 5-HT2 receptors participate in secretory processes in the honeybee. Conclusions This study marks the first molecular and pharmacological characterization of two 5-HT2 receptor subtypes in the same insect species. The results presented should facilitate further attempts to unravel central and peripheral effects of serotonin mediated by these receptors. PMID:24324783

The 5-HT{sub 2A} serotoninergic receptor is expressed in the MCF-7 human breast cancer cell line and reveals a mitogenic effect of serotonin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sonier, Brigitte; Arseneault, Madeleine; Institut National de la Recherche Scientifique-Institut Armand-Frappier, Montreal, Que.

2006-05-19

Serotonin (5-hydroxytryptamine, 5-HT) has been described as a mitogen in a variety of cell types and carcinomas. It exerts its mitogenic effect by interacting with a wide range of 5-HT receptor types. Certain studies suggest that some selective serotonin re-uptake inhibitors promote breast cancer in animals and humans. This study attempts to clarify the role of serotonin in promoting the growth of neoplastic mammary cells. Expression of the 5-HT{sub 2A} serotoninergic receptor subtype in MCF-7 cells was determined by RT-PCR, Western blotting, and immunofluorescence analysis. The mitogenic effect of 5-HT on MCF-7 cells was determined by means of the MTTmore » proliferation assay. We have demonstrated that the 5-HT{sub 2A} receptor subtype is fully expressed in the MCF-7 human breast cancer cell line, in terms of encoding mRNA and receptor protein. Automated sequencing has confirmed that the 5-HT{sub 2A} receptor present in this cell line is identical to the 5-HT{sub 2A} receptor found in human platelets and in human cerebral cortex. Furthermore, this receptor was found by immunofluorescence to be on the plasma membrane. MTT proliferation assays revealed that 5-HT and DOI, a selective 5-HT{sub 2A} receptor subtype agonist, stimulated MCF-7 cell. These results indicate that 5-HT plays a mitogenic role in neoplastic mammary cells. Our data also indicate that 5-HT exerts this positive growth effect on MCF-7 cells through, in part, the 5-HT{sub 2A} receptor subtype, which is fully expressed in this cell line.« less

Divergent Label-free Cell Phenotypic Pharmacology of Ligands at the Overexpressed β2-Adrenergic Receptors

NASA Astrophysics Data System (ADS)

Ferrie, Ann M.; Sun, Haiyan; Zaytseva, Natalya; Fang, Ye

2014-01-01

We present subclone sensitive cell phenotypic pharmacology of ligands at the β2-adrenergic receptor (β2-AR) stably expressed in HEK-293 cells. The parental cell line was transfected with green fluorescent protein (GFP)-tagged β2-AR. Four stable subclones were established and used to profile a library of sixty-nine AR ligands. Dynamic mass redistribution (DMR) profiling resulted in a pharmacological activity map suggesting that HEK293 endogenously expresses functional Gi-coupled α2-AR and Gs-coupled β2-AR, and the label-free cell phenotypic activity of AR ligands are subclone dependent. Pathway deconvolution revealed that the DMR of epinephrine is originated mostly from the remodeling of actin microfilaments and adhesion complexes, to less extent from the microtubule networks and receptor trafficking, and certain agonists displayed different efficacy towards the cAMP-Epac pathway. We demonstrate that receptor signaling and ligand pharmacology is sensitive to the receptor expression level, and the organization of the receptor and its signaling circuitry.

γ-Aminobutyric Acid Type A α4, β2, and δ Subunits Assemble to Produce More Than One Functionally Distinct Receptor Type

PubMed Central

Eaton, Megan M.; Bracamontes, John; Shu, Hong-Jin; Li, Ping; Mennerick, Steven; Steinbach, Joe Henry

2014-01-01

Native γ-aminobutyric acid (GABA)A receptors consisting of α4, β1–3, and δ subunits mediate responses to the low, tonic concentration of GABA present in the extracellular milieu. Previous studies on heterologously expressed α4βδ receptors have shown a large degree of variability in functional properties, including sensitivity to the transmitter. We studied properties of α4β2δ receptors employing free subunits and concatemeric constructs, expressed in Xenopus oocytes, HEK 293 cells, and cultured hippocampal neurons. The expression system had a strong effect on the properties of receptors containing free subunits. The midpoint of GABA activation curve was 10 nM for receptors in oocytes versus 2300 nM in HEK cells. Receptors activated by the steroid alfaxalone had an estimated maximal open probability of 0.6 in oocytes and 0.01 in HEK cells. Irrespective of the expression system, receptors resulting from combining the tandem construct β2-δ and a free α4 subunit exhibited large steroid responses. We propose that free α4, β2, and δ subunits assemble in different configurations with distinct properties in oocytes and HEK cells, and that subunit linkage can overcome the expression system-dependent preferential assembly of free subunits. Hippocampal neurons transfected with α4 and the picrotoxin-resistant δ(T269Y) subunit showed large responses to alfaxalone in the presence of picrotoxin, suggesting that α4βδ receptors may assemble in a similar configuration in neurons and oocytes. PMID:25238745

CD86 and beta2-adrenergic receptor signaling pathways, respectively, increase Oct-2 and OCA-B Expression and binding to the 3'-IgH enhancer in B cells.

PubMed

Podojil, Joseph R; Kin, Nicholas W; Sanders, Virginia M

2004-05-28

Stimulation of CD86 (formerly known as B7-2) and/or the beta2-adrenergic receptor on a CD40 ligand/interleukin-4-activated B cell increased the rate of mature IgG1 transcription. To identify the mechanism responsible for this effect, we determined whether CD86 and/or beta2-adrenergic receptor stimulation regulated transcription factor expression and binding to the 3'-IgH enhancer in vitro and in vivo. We showed that CD86 stimulation increased the nuclear localization of NF-kappaB1 (p50) and phosphorylated RelA (p65) and increased Oct-2 expression and binding to the 3'-IgH enhancer, in a protein kinase C-dependent manner. These effects were lost when CD86-deficient or NF-kappaB1-deficient B cells were used. CD86 stimulation also increased the level of IkappaB-alpha phosphorylation but in a protein kinase C-independent manner. Beta2-adrenergic receptor stimulation increased CREB phosphorylation, OCA-B expression, and OCA-B binding to the 3'-IgH enhancer in a protein kinase A-dependent manner, an effect lost when beta2-adrenergic receptor-deficient B cells were used. Also, the beta2-adrenergic receptor-induced increase in the level of mature IgG1 transcript was lost when OCA-B-deficient B cells were used. These data are the first to show that CD86 stimulation up-regulates the expression of the transcription factor Oct-2 in a protein kinase C- and NF-kappaB1-dependent manner, and that beta2-adrenergic receptor stimulation up-regulates the expression of the coactivator OCA-B in a protein kinase A-dependent manner to cooperate with Oct-2 binding to the 3'-IgH enhancer.

Association between AT1 and AT2 angiotensin II receptor expression with cell proliferation and angiogenesis in operable breast cancer.

PubMed

Arrieta, Oscar; Villarreal-Garza, Cynthia; Vizcaíno, Gloria; Pineda, Benjamín; Hernández-Pedro, Norma; Guevara-Salazar, Patricia; Wegman-Ostrosky, Talia; Villanueva-Rodríguez, Geraldine; Gamboa-Domínguez, Armando

2015-07-01

Angiotensin II (ANGII) has been associated with vascular proliferation in tumor and non-tumor models through its receptors AT1 and AT2. Our objective was to determine AT1 and AT2 receptor expression in operable breast cancer and its association with tumor grade, vascular density, and cellular proliferation. Seventy-seven surgically malignant breast tumors with no distant metastasis were included, and 7 benign lesions were used as controls. AT1 and AT2 receptor expression was determined by RT-PCR and immunohistochemistry (IHC) in 68 out of the 77 malignant lesions and in the 7 benign lesions. AT1 and AT2 receptor expression was detected in 35.3 and 25 % of cases, in both RT-PCR and IHC. Tumors that express AT1 showed an increase in T3 stage (92.3 vs. 7.7 % p < 0.001), mitotic index (4 ± 1 vs 2 ± 1, p = 0.05), vascular density (15 ± 3 vs 8 ± 5, p = 0.05), and cellular proliferation (85 ± 18 vs 55 ± 10, p = 0.01) versus AT1-negative lesions. Non-differences between clinical-pathologic variables and AT2 expression were found. AT1 receptor expression was associated to enhance angiogenesis and cellular proliferation rate, but no relationship with AT2 was found. ANGII and its peptides might play a role in the development and pathophysiology of breast cancer, and this could be valuable in the in the development of targeted therapies.

A tissue microarray study of toll-like receptor 4, decoy receptor 3, and external signal regulated kinase 1/2 expressions in astrocytoma.

PubMed

Lin, Chih-Kung; Ting, Chun-Chieh; Tsai, Wen-Chiuan; Chen, Yuan-Wu; Hueng, Dueng-Yuan

2016-01-01

Decoy receptor 3 (DcR3) functions as a death decoy inhibiting apoptosis mediated by the tumor necrosis factor receptor family. It is highly expressed in many tumors and its expression can be regulated by the MAPK/ERK signaling pathway and ERK is a vital member of this pathway. Toll-like receptor 4 (TLR4) is expressed on immune cells. Increased TLR4 expression has been associated with various types of cancers. The study was conducted to investigate the expression of DcR3, ERK1/2, and TLR4 in astrocytomas and evaluate if they are validating markers for discriminating glioblastoma from anaplastic astrocytoma in limited surgical specimen. Expression of DcR3, ERK1/2, and TLR4 was determined by immunohistochemical staining of tissue microarray from 48 paraffin-embedded tissues. A binary logistic regression method was used to generate functions that discriminate between anaplastic astrocytomas and glioblastomas. The expression of TLR4 and DcR3 was significantly higher in glioblastomas than in anaplastic astrocytomas. DcR3 could discriminate anaplastic astrocytomas from glioblastomas with high sensitivity (93.8%), specificity (90%), and accuracy (92.3%). Our results suggest that DcR3 may be a useful marker for discriminating anaplastic astrocytomas from glioblastomas.

Induction of hepatic ABC transporter expression is part of the PPARalpha-mediated fasting response in the mouse.

PubMed

Kok, Tineke; Wolters, Henk; Bloks, Vincent W; Havinga, Rick; Jansen, Peter L M; Staels, Bart; Kuipers, Folkert

2003-01-01

Fatty acids are natural ligands of the peroxisome proliferator-activated receptor alpha (PPARalpha). Synthetic ligands of this nuclear receptor, i.e., fibrates, induce the hepatic expression of the multidrug resistance 2 gene (Mdr2), encoding the canalicular phospholipid translocator, and affect hepatobiliary lipid transport. We tested whether fasting-associated fatty acid release from adipose tissues alters hepatic transporter expression and bile formation in a PPARalpha-dependent manner. A 24-hour fasting/48-hour refeeding schedule was used in wild-type and Pparalpha((-/-)) mice. Expression of genes involved in the control of bile formation was determined and related to secretion rates of biliary components. Expression of Pparalpha, farnesoid X receptor, and liver X receptor alpha genes encoding nuclear receptors that control hepatic bile salt and sterol metabolism was induced on fasting in wild-type mice only. The expression of Mdr2 was 5-fold increased in fasted wild-type mice and increased only marginally in Pparalpha((-/-)) mice, and it normalized on refeeding. Mdr2 protein levels and maximal biliary phospholipid secretion rates were clearly increased in fasted wild-type mice. Hepatic expression of the liver X receptor target genes ATP binding cassette transporter a1 (Abca1), Abcg5, and Abcg8, implicated in hepatobiliary cholesterol transport, was induced in fasted wild-type mice only. However, the maximal biliary cholesterol secretion rate was reduced by approximately 50%. Induction of Mdr2 expression and function is part of the PPARalpha-mediated fasting response in mice. Fasting also induces expression of the putative hepatobiliary cholesterol transport genes Abca1, Abcg5, and Abcg8, but, nonetheless, maximal biliary cholesterol excretion is decreased after fasting.

Effect of lappaconitine on neuropathic pain mediated by P2X3 receptor in rat dorsal root ganglion.

PubMed

Ou, Shan; Zhao, Yan-Dong; Xiao, Zhi; Wen, Hui-Zhong; Cui, Jian; Ruan, Huai-Zhen

2011-04-01

ATP facilitates initiation and transmission of the neuropathic pain at the dorsal root ganglion (DRG) level via the P2X receptors, especially the subtype P2X(3). Lappaconitine (LA) is an active principle isolated from Chinese herbal medicine and possesses analgesic effect. The aim of this study was to investigate the effect of LA on chronic constriction injury (CCI)-induced neuropathic pain mediated by P2X(3) receptor in the DRG neurons. In the presence of CCI and/or LA, the mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) were measured and P2X(3) receptor expression in the DRG neurons was evaluated by immunohistochemistry and Western blotting. Following intrathecal administration of P2X(3) receptor oligonucleotide, the effect of LA on pain thresholds was assessed. Furthermore, the effect of LA on the P2X(3) receptor agonists ATP- and α,β-meATP-induced inward currents (I(ATP) and I(α,β-meATP)) in the acutely dissociated rat DRG neurons was investigated by whole cell patch-clamp. The results included: (1) There showed reduction of pain thresholds, enhancement of I(ATP) and I(α,β-meATP) and up-regulation of P2X(3) receptor expression in rat DRG neurons when neuropathic pain occurred. (2) In the presence of LA, the decreased pain thresholds, the up-regulated P2X(3) receptor expression and the enhanced I(ATP) and I(α,β-meATP) were reversible in the CCI rats. (3) The down-regulated P2X(3) receptor expression with pretreatment of P2X(3) receptor antisense oligonucleotide significantly attenuated the analgesic effect of LA. These results indicate that the analgesic effect of LA involves decrease of expression and sensitization of the P2X(3) receptors of the rat DRG neurons following CCI. Copyright © 2011 Elsevier Ltd. All rights reserved.

Altered striatal function in a mutant mouse lacking D1A dopamine receptors.

PubMed Central

Drago, J; Gerfen, C R; Lachowicz, J E; Steiner, H; Hollon, T R; Love, P E; Ooi, G T; Grinberg, A; Lee, E J; Huang, S P

1994-01-01

Of the five known dopamine receptors, D1A and D2 represent the major subtypes expressed in the striatum of the adult brain. Within the striatum, these two subtypes are differentially distributed in the two main neuronal populations that provide direct and indirect pathways between the striatum and the output nuclei of the basal ganglia. Movement disorders, including Parkinson disease and various dystonias, are thought to result from imbalanced activity in these pathways. Dopamine regulates movement through its differential effects on D1A receptors expressed by direct output neurons and D2 receptors expressed by indirect output neurons. To further examine the interaction of D1A and D2 neuronal pathways in the striatum, we used homologous recombination to generate mutant mice lacking functional D1A receptors (D1A-/-). D1A-/- mutants are growth retarded and die shortly after weaning age unless their diet is supplemented with hydrated food. With such treatment the mice gain weight and survive to adulthood. Neurologically, D1A-/- mice exhibit normal coordination and locomotion, although they display a significant decrease in rearing behavior. Examination of the striatum revealed changes associated with the altered phenotype of these mutants. D1A receptor binding was absent in striatal sections from D1A-/- mice. Striatal neurons normally expressing functional D1A receptors are formed and persist in adult homozygous mutants. Moreover, substance P mRNA, which is colocalized specifically in striatal neurons with D1A receptors, is expressed at a reduced level. In contrast, levels of enkephalin mRNA, which is expressed in striatal neurons with D2 receptors, are unaffected. These findings show that D1A-/- mice exhibit selective functional alterations in the striatal neurons giving rise to the direct striatal output pathway. Images Fig. 2 Fig. 4 PMID:7809078

Apoptosis gene expression and death receptor signaling in mitomycin-C-treated human tenon capsule fibroblasts.

PubMed

Crowston, Jonathan G; Chang, Lydia H; Constable, Peter H; Daniels, Julie T; Akbar, Arne N; Khaw, Peng T

2002-03-01

To examine the effect of mitomycin-C on the expression of apoptosis genes in human Tenon capsule fibroblasts and to evaluate whether death receptor signaling modulates mitomycin-C cytotoxicity. Bcl-2, Bax, Bcl-x, Fas (CD95) and tumor necrosis factor (TNF) receptor expression was determined by flow cytometry in control and mitomycin-C-treated Tenon fibroblasts. Fibroblast death was quantified using a lactate dehydrogenase release assay. The effect of Fas and TNF-receptor signaling was evaluated using Fas-specific antibodies and soluble TNF-alpha. Tenon fibroblasts constitutively express Bcl-2, Bax, and Bcl-x in culture. Mitomycin-C (0.4 mg/mL) induced a small but consistent increase in the expression of all three proteins. Tenon fibroblasts express low levels of Fas but are resistant to the effects of Fas-receptor ligation. Mitomycin-C (0.01-1.0 mg/mL) led to a significant increase in Fas expression at all concentrations tested (P < 0.01). Pretreatment with mitomycin-C (0.4 mg/mL) rendered fibroblasts susceptible to agonistic anti-Fas monoclonal IgM antibodies (50-500 ng/mL) and led to a further 50% reduction in viable fibroblasts at 48 hours, compared with mitomycin-C alone (P < 0.05). Antibodies that block the Fas receptor did not inhibit mitomycin-C-induced apoptosis. Mitomycin-C alters apoptosis gene expression and primes fibroblasts to the effects of Fas receptor ligation. Factors other than the level of Fas receptor expression modulate the response to Fas receptor signaling. Determining the signals that regulate fibroblast apoptosis may help to refine therapeutic strategies for switching off the subconjunctival healing response and maintaining intraocular pressure control.

Heterodimerization with beta2-adrenergic receptors promotes surface expression and functional activity of alpha1D-adrenergic receptors.

PubMed

Uberti, Michelle A; Hague, Chris; Oller, Heide; Minneman, Kenneth P; Hall, Randy A

2005-04-01

The alpha1D-adrenergic receptor (alpha1D-AR) is a G protein-coupled receptor (GPCR) that is poorly trafficked to the cell surface and largely nonfunctional when heterologously expressed by itself in a variety of cell types. We screened a library of approximately 30 other group I GPCRs in a quantitative luminometer assay for the ability to promote alpha1D-AR cell surface expression. Strikingly, these screens revealed only two receptors capable of inducing robust increases in the amount of alpha1D-AR at the cell surface: alpha1B-AR and beta2-AR. Confocal imaging confirmed that coexpression with beta2-AR resulted in translocation of alpha1D-AR from intracellular sites to the plasma membrane. Additionally, coimmunoprecipitation studies demonstrated that alpha1D-AR and beta2-AR specifically interact to form heterodimers when coexpressed in HEK-293 cells. Ligand binding studies revealed an increase in total alpha1D-AR binding sites upon coexpression with beta2-AR, but no apparent effect on the pharmacological properties of the receptors. In functional studies, coexpression with beta2-AR significantly enhanced the coupling of alpha1D-AR to norepinephrine-stimulated Ca2+ mobilization. Heterodimerization of beta2-AR with alpha1D-AR also conferred the ability of alpha1D-AR to cointernalize upon beta2-AR agonist stimulation, revealing a novel mechanism by which these different adrenergic receptor subtypes may regulate each other's activity. These findings demonstrate that the selective association of alpha1D-AR with other receptors is crucial for receptor surface expression and function and also shed light on a novel mechanism of cross talk between alpha1- and beta2-ARs that is mediated through heterodimerization and cross-internalization.

Lower expressions of the human bitter taste receptor TAS2R in smokers: reverse transcriptase-polymerase chain reaction analysis.

PubMed

Aoki, Mieko; Takao, Tetsuya; Takao, Kyoichi; Koike, Fumihiko; Suganuma, Narufumi

2014-01-01

Despite the fact that smokers have deficit in detecting taste, particularly bitter taste, no study has investigated its biological correlate. In this context, we compared the expression of the bitter taste receptor gene, taste 2 receptor (TAS2R) in the tongues of smokers and non-smokers. Tissue samples were collected from the lateral portion of the tongues of 22 smokers and 22 age- and gender-matched healthy volunteers (19 males and three females) with no history of smoking. Reverse transcriptase-polymerase chain reaction was used to examine the expression of TAS2R in the two groups, and the effect of aging on TAS2R expression was also assessed. TAS2R expression was significantly lower among smokers than non-smokers (t = 6.525, P < .0001, 11.36 ± 6.0 vs. 2.09 ± 2.8, mean ± SD, non-smokers vs. smokers). Further, a positive correlation between age and expression of TAS2R was observed in non-smokers (r = .642, P = .001), but not smokers (r = .124, P = .584). This correlation difference was significant (Z = 1.96, P = .0496). Smokers showed a significantly lower expression of the bitter taste receptor gene than non-smokers, which is potentially caused by their inability to acquire such receptors with age because of cigarette smoking, in contrast to non-smokers.

Vasopressin up-regulates the expression of growth-related immediate-early genes via two distinct EGF receptor transactivation pathways

PubMed Central

Fuentes, Lida Q.; Reyes, Carlos E.; Sarmiento, José M.; Villanueva, Carolina I.; Figueroa, Carlos D.; Navarro, Javier; González, Carlos B.

2008-01-01

Activation of V1a receptor triggers the expression of growth-related immediate-early genes (IEGs), including c-Fos and Egr-1. Here we found that pre-treatment of rat vascular smooth muscle A-10 cell line with the EGF receptor inhibitor AG1478 or the over-expression of an EGFR dominant negative mutant (HEBCD533) blocked the vasopressin-induced expression of IEGs, suggesting that activation of these early genes mediated by V1a receptor is via transactivation of the EGF receptor. Importantly, the inhibition of the metalloproteinases, which catalyzed the shedding of the EGF receptor agonist HB-EGF, selectively blocked the vasopressin-induced expression c-Fos. On the other hand, the inhibition of c-Src selectively blocked the vasopressin-induced expression of Egr-1. Interestingly, in contrast to the expression of c-Fos, the expression of Egr-1 was mediated via the Ras/MEK/MAPK-dependent signalling pathway. Vasopressin-triggered expression of both genes required the release of intracellular calcium, activation of PKC and β-arrestin 2. These findings demonstrated that vasopressin up-regulated the expression of c-Fos and Erg-1 via transactivation of two distinct EGF receptor-dependent signalling pathways. PMID:18571897

Lipid-sensors, enigmatic-orphan and orphan nuclear receptors as therapeutic targets in breast-cancer.

PubMed

Garattini, Enrico; Bolis, Marco; Gianni', Maurizio; Paroni, Gabriela; Fratelli, Maddalena; Terao, Mineko

2016-07-05

Breast-cancer is heterogeneous and consists of various groups with different biological characteristics. Innovative pharmacological approaches accounting for this heterogeneity are needed. The forty eight human Nuclear-Hormone-Receptors are ligand-dependent transcription-factors and are classified into Endocrine-Receptors, Adopted-Orphan-Receptors (Lipid-sensors and Enigmatic-Orphans) and Orphan-receptors. Nuclear-Receptors represent ideal targets for the design/synthesis of pharmacological ligands. We provide an overview of the literature available on the expression and potential role played by Lipid-sensors, Enigmatic-Orphans and Orphan-Receptors in breast-cancer. The data are complemented by an analysis of the expression levels of each selected Nuclear-Receptor in the PAM50 breast-cancer groups, following re-elaboration of the data publicly available. The major aim is to support the idea that some of the Nuclear-Receptors represent largely unexploited therapeutic-targets in breast-cancer treatment/chemo-prevention. On the basis of our analysis, we conclude that the Lipid-Sensors, NR1C3, NR1H2 and NR1H3 are likely to be onco-suppressors in breast-cancer. The Enigmatic-Orphans, NR1F1 NR2A1 and NR3B3 as well as the Orphan-Receptors, NR0B1, NR0B2, NR1D1, NR2F1, NR2F2 and NR4A3 exert a similar action. These Nuclear-Receptors represent candidates for the development of therapeutic strategies aimed at increasing their expression or activating them in tumor cells. The group of Nuclear-Receptors endowed with potential oncogenic properties consists of the Lipid-Sensors, NR1C2 and NR1I2, the Enigmatic-Orphans, NR1F3, NR3B1 and NR5A2, as well as the Orphan-Receptors, NR2E1, NR2E3 and NR6A1. These oncogenic Nuclear-Receptors should be targeted with selective antagonists, reverse-agonists or agents/strategies capable of reducing their expression in breast-cancer cells.

Histaminergic Receptors Modulate Spinal Cord Injury-Induced Neuronal Nitric Oxide Synthase Upregulation and Cord Pathology: New Roles of Nanowired Drug Delivery for Neuroprotection.

PubMed

Sharma, Hari S; Patnaik, Ranjana; Muresanu, Dafin F; Lafuente, José V; Ozkizilcik, Asya; Tian, Z Ryan; Nozari, Ala; Sharma, Aruna

2017-01-01

The possibility that histamine influences the spinal cord pathophysiology following trauma through specific receptor-mediated upregulation of neuronal nitric oxide synthase (nNOS) was examined in a rat model. A focal spinal cord injury (SCI) was inflicted by a longitudinal incision into the right dorsal horn of the T10-11 segments. The animals were allowed to survive 5h. The SCI significantly induced breakdown of the blood-spinal cord barrier to protein tracers, reduced the spinal cord blood flow at 5h, and increased the edema formation and massive upregulation of nNOS expression. Pretreatment with histamine H1 receptor antagonist mepyramine (1mg, 5mg, and 10mg/kg, i.p., 30min before injury) failed to attenuate nNOS expression and spinal cord pathology following SCI. On the other hand, blockade of histamine H2 receptors with cimetidine or ranitidine (1mg, 5mg, or 10mg/kg) significantly reduced these early pathophysiological events and attenuated nNOS expression in a dose-dependent manner. Interestingly, TiO 2 -naowire delivery of cimetidine or ranitidine (5mg doses) exerted superior neuroprotective effects on SCI-induced nNOS expression and cord pathology. It appears that effects of ranitidine were far superior than cimetidine at identical doses in SCI. On the other hand, pretreatment with histamine H3 receptor agonist α-methylhistamine (1mg, 2mg, or 5mg/kg, i.p.) that inhibits histamine synthesis and release in the central nervous system thwarted the spinal cord pathophysiology and nNOS expression when used in lower doses. Interestingly, histamine H3 receptor antagonist thioperamide (1mg, 2mg, or 5mg/kg, i.p.) exacerbated nNOS expression and cord pathology after SCI. These novel observations suggest that blockade of histamine H2 receptors or stimulation of histamine H3 receptors attenuates nNOS expression and induces neuroprotection in SCI. Taken together, our results are the first to demonstrate that histamine-induced pathophysiology of SCI is mediated via nNOS expression involving specific histamine receptors. © 2017 Elsevier Inc. All rights reserved.

Somatostatin and Somatostatin Receptor Gene Expression in Dominant and Subordinate Males of an African Cichlid Fish

PubMed Central

Trainor, Brian C.; Hofmann, Hans A.

2009-01-01

Somatostatin is a neuropeptide best known for its inhibitory effects on growth hormone secretion and has recently been implicated in the control of social behavior. Several somatostatin receptor subtypes have been identified in vertebrates, but the functional basis for this diversity is still unclear. Here we investigate the expression levels of the somatostatin prepropeptide and two of its receptors, sstR2, and sstR3, in the brains of socially dominant and subordinate A. burtoni males using real-time PCR. Dominant males had higher somatostatin prepropeptide and sstR3 expression in hypothalamus compared to subordinate males. Hypothalamic sstR2 expression did not differ. There were no differences in gene expression in the telencephalon. We also observed an interesting difference between dominants and subordinates in the relationship between hypothalamic sstR2 expression and body size. As would be predicted based on the inhibitory effects of somatostatin on somatic growth, sstR2 expression was negatively correlated with body size in dominant males. In contrast sstR2 expression was positively correlated with body size in subordinate males. These results suggest that somatostatin prepropeptide and receptor gene expression in the hypothalamus are associated with the control of somatic growth in A. burtoni depending on social status. PMID:17374406

Variation of M3 muscarinic receptor expression in different prostate tissues and its significance.

PubMed

Song, Wei; Yuan, Mingzhen; Zhao, Shengtian

2009-08-01

To detect the expression of the muscarinic receptor (M receptor) in different prostate tissues and analyze the role of its subtype in prostatic oncogenesis. Thirty-six cases of normal prostate and benign prostatic hyperplasia, and 8 cases of prostatic tumor, were used in this study from the Shandong University, Shandong, China, between 2003-2006. The protein expressions of M1, M2, and M3 receptors in each group were determined by Western-blotting. The gene expressions of the M3 receptor and vascular endothelial growth factors (VEGF) in each group were determined by reverse transcriptase-polymerase chain reaction. The protein and gene expressions of the M3 receptor in the prostatic carcinoma group were higher than that of benign prostatic hyperplasia group (p=0.0001) and normal prostate group (p=0.0001). The M3 receptor and VEGF showed positive straight-line correlations of gene expressions with the 3 groups (r=0.4999, p=0.0001). The M3 receptor may have a close relationship with prostatic oncogenesis.

Enhancement of bradykinin and resensitization of its B2 receptor.

PubMed

Marcic, B; Deddish, P A; Jackman, H L; Erdös, E G

1999-03-01

We studied the enhancement of the effects of bradykinin B2 receptor agonists by agents that react with active centers of angiotensin-converting enzyme (ACE) independent of enzymatic inactivation. The potentiation and the desensitization and resensitization of B2 receptor were assessed by measuring [3H]arachidonic acid release and [Ca2+]i mobilization in Chinese hamster ovary cells transfected to express human ACE and B2 receptor, or in endothelial cells with constitutively expressed ACE and receptor. Administration of bradykinin or its ACE-resistant analogue desensitized the receptor, but it was resensitized (arachidonic acid release or [Ca2+]i mobilization) by agents such as enalaprilat (1 micromol/L). Enalaprilat was inactive in the absence of ACE expression. La3+ (100 micromol/L) inhibited the apparent resensitization, probably by blocking the entry of extracellular calcium. Enalaprilat resensitized the receptor via ACE to release arachidonic acid by bradykinin at a lower concentration (5 nmol/L) than required to mobilize [Ca2+]i (1 micromol/L). Monoclonal antibodies inhibiting the ACE N-domain active center and polyclonal antiserum potentiated bradykinin. The snake venom peptide BPP5a and metabolites of angiotensin and bradykinin (angiotensin-[1-9], angiotensin-[1-7], bradykinin-[1-8]; 1 micromol/L) enhanced arachidonic acid release by bradykinin. Angiotensin-(1-9) and -(1-7) also resensitized the receptor. Enalaprilat potentiated the bradykinin effect in cells expressing a mutant ACE with a single N-domain active site. Agents that reacted with a single active site, on the N-domain or on the C-domain, potentiated bradykinin not by blocking its inactivation but by inducing crosstalk between ACE and the receptor. Enalaprilat enhanced signaling via ACE by Galphai in lower concentration than by Galphaq-coupled receptor.

Bacterial expression and purification of a heterodimeric adrenomedullin receptor extracellular domain complex using DsbC-assisted disulfide shuffling.

PubMed

Hill, Heather E; Pioszak, Augen A

2013-03-01

Adrenomedullin (AM) is a peptide hormone that is a potent vasodilator and is essential for vascular development. The AM receptor is a heterodimeric cell surface receptor composed of the calcitonin receptor-like receptor (CLR), a class B G protein-coupled receptor, in association with either of two receptor activity modifying protein (RAMP) coreceptors, RAMP2 or -3. The extracellular domains (ECDs) of CLR and the RAMPs form the primary AM binding site. Here, we present novel methodology for expression and purification of a heterodimeric AM receptor ECD complex as an MBP-CLR ECD fusion protein in association with the RAMP2 ECD. Co-expression of the RAMP2 ECD with the disulfide bond isomerase DsbC in the oxidizing cytoplasm of E. coli trxB gor enabled proper disulfide formation in vivo. The isolated RAMP2 ECD was purified to homogeneity. Co-expression of a soluble MBP-CLR ECD fusion protein with DsbC in E. coli trxB gor yielded a heterogeneous mixture of species with misfolded ECD. Incubation of affinity-purified MBP-CLR ECD in vitro with purified RAMP2 ECD, DsbC, and glutathione redox buffer promoted proper folding of the CLR ECD and formation of a stable MBP-CLR ECD:RAMP2 ECD complex that was purified by size-exclusion chromatography and which exhibited specific AM binding. Approximately 40mg of highly purified complex was obtained starting with 6L bacterial cultures for each protein. The methodology reported here will facilitate structure/function studies of the AM receptor. Copyright © 2012 Elsevier Inc. All rights reserved.

Opiate physical dependence and N-methyl-D-aspartate receptors.

PubMed

Noda, Yukihiro; Nabeshima, Toshitaka

2004-10-01

The present review focused the involvement of N-methyl-D-aspartate (NMDA) receptors in morphine physical dependence. The increased levels of extracellular glutamate, NMDA receptor zeta subunit (NR1) mRNA, NMDA receptor epsilon 1 subunit (NR2A) protein, phosphorylated Ca(2+)/calmodulin kinase II (p-CaMKII) protein, c-fos mRNA, c-Fos protein, are observed in the specific brain areas of mice and/or rats showing signs of naloxone-precipitated withdrawal. In preclinical and clinical studies, a variety of NMDA receptor antagonists and pretreatment with an antisense oligonucleotide of the NR1 have been reported to inhibit the development, expression and/or maintenance of opiate physical dependence. In contrast to data obtained in adult animals, NMDA receptor antagonists are neither effective in blocking the development of opiate dependence nor the expression of opiate withdrawal in neonatal rats. In the NMDA receptor-deficient mice, the NR2A knockout mice show the marked loss of typical withdrawal abstinence behaviors precipitated by naloxone. The rescue of NR2A protein by electroporation into the nucleus accumbens of NR2A knockout mice reverses the loss of abstinence behaviors. The activation of CaMKII and increased expression of c-Fos protein in the brain of animals with naloxone-precipitated withdrawal syndrome are prevented by NMDA receptor antagonists, whereas the increased levels of extracellular glutamate are not prevented by them. These findings indicate that glutamatergic neurotransmission at the NMDA receptor site contributes to the development, expression and maintenance of opiate dependence, and suggest that NMDA receptor antagonists may be a useful adjunct in the treatment of opiate dependence.

Molecular and functional characterization of the first tick CAP2b (periviscerokinin) receptor from Rhipicephalus (Boophilus) microplus (Acari: Ixodidae).

PubMed

Yang, Yunlong; Bajracharya, Prati; Castillo, Paula; Nachman, Ronald J; Pietrantonio, Patricia V

2013-12-01

The cDNA of the receptor for CAP(2b)/periviscerokinin (PVK) neuropeptides, designated Rhimi-CAP(2b)-R, was cloned from synganglia of tick Rhipicephalus (Boophilus) microplus. This receptor is the ortholog of the insect CAP(2b)/PVK receptor, as concluded from analyses of the predicted protein sequence, phylogenetics and functional expression. Expression analyses of synganglion, salivary gland, Malpighian tubule, and ovary revealed Rhimi-CAP(2b)-R transcripts. The expression in mammalian cells of the open reading frame of Rhimi-CAP(2b)-R cDNA fused with a hemagglutinin tag at the receptor N-terminus was confirmed by immunocytochemistry. In a calcium bioluminescence assay the recombinant receptor was activated by the tick Ixodes scapularis CAP(2b)/PVK and a PVK analog with EC₅₀s of 64 nM and 249 nM, respectively. Tick pyrokinins were not active. This is the first report on the functional characterization of the CAP(2b)/PVK receptor from any tick species which will now permit the discovery of the physiological roles of these neuropeptides in ticks, as neurohormones, neuromodulators and/or neurotransmitters. Copyright © 2013 Elsevier Inc. All rights reserved.

Regulation of IP 3 Receptors by IP 3 and Ca 2+

NASA Astrophysics Data System (ADS)

Taylor, Colin W.; Swatton, Jane E.

Inositol 1,4,5-trisphosphate ( IP 3) receptors are intracellular Ca 2+ channels that mediate release of Ca 2+ from intracellular stores. The channels are oligomeric assemblies of four subunits, each of which has an N-terminal IP 3-binding domain and each of which contributes to formation of the Ca 2+ channel. In mammals, three different genes encode IP 3 receptors subunits and the type 1 receptor (and perhaps the type 2 receptor) is also expressed as splice variants. Further diversity arises from assembly of the receptor in hetero- and homo-tetrameric channels. The subtypes differ in their expression and regulation, but they share the key property of being regulated by both IP3 and cytosolic Ca 2+. All three mammalian IP 3 subtypes, and probably also the IP 3 receptors expressed in invertebrates, are biphasically regulated by cytosolic Ca2+, although the underlying mechanisms appear to differ between subtypes. The interactions between IP 3 and Ca 2+ in controlling IP 3 receptor gating, and the physiological significance of such regulation will be reviewed.

PGE2 signaling through the EP4 receptor on fibroblasts upregulates RANKL and stimulates osteolysis.

PubMed

Tsutsumi, Ryosuke; Xie, Chao; Wei, Xiaochao; Zhang, Minjie; Zhang, Xinping; Flick, Lisa M; Schwarz, Edward M; O'Keefe, Regis J

2009-10-01

Periprosthetic osteolysis is the most common cause of aseptic loosening in total joint arthroplasty. The role of inflammatory mediators such as prostaglandin E2 (PGE2) and osteoclast promoting factors including RANKL in the pathogenesis of osteolysis has been well characterized. However, the PGE2 receptor (EP1, EP2, or EP4), and cell type in which it is expressed, which is responsible for PGE2 induction of RANKL during wear debris-induced osteolysis, has yet to be elucidated. To address this, we used mice genetically deficient in these EP receptors to assess PGE2 and wear debris responses in vitro and in vivo. Wear debris-induced osteolysis and RANKL expression were observed at similar levels in WT, EP1(-/-), and EP2(-/-) mice, indicating that these receptors do not mediate PGE2 signals in this process. A conditional knockout approach was used to eliminate EP4 expression in FSP1(+) fibroblasts that are the predominant source of RANKL. In the absence of EP4, fibroblasts do not express RANKL after stimulation with particles or PGE2, nor do they exhibit high levels of osteoclasts and osteolysis. These results show that periprosthetic fibroblasts are important mediators of osteolysis through the expression of RANKL, which is induced after PGE2 signaling through the EP4 receptor.

Olfactory discrimination largely persists in mice with defects in odorant receptor expression and axon guidance

PubMed Central

2012-01-01

Background The defining feature of the main olfactory system in mice is that each olfactory sensory neuron expresses only one of more than a thousand different odorant receptor genes. Axons expressing the same odorant receptor converge onto a small number of targets in the olfactory bulb such that each glomerulus is made up of axon terminals expressing just one odorant receptor. It is thought that this precision in axon targeting is required to maintain highly refined odor discrimination. We previously showed that β3GnT2−/− mice have severe developmental and axon guidance defects. The phenotype of these mice is similar to adenylyl cyclase 3 (AC3) knockout mice largely due to the significant down-regulation of AC3 activity in β3GnT2−/− neurons. Results Microarray analysis reveals that nearly one quarter of all odorant receptor genes are down regulated in β3GnT2−/− mice compared to controls. Analysis of OR expression by quantitative PCR and in situ hybridization demonstrates that the number of neurons expressing some odorant receptors, such as mOR256-17, is increased by nearly 60% whereas for others such as mOR28 the number of neurons is decreased by more than 75% in β3GnT2−/− olfactory epithelia. Analysis of axon trajectories confirms that many axons track to inappropriate targets in β3GnT2−/− mice, and some glomeruli are populated by axons expressing more than one odorant receptor. Results show that mutant mice perform nearly as well as control mice in an odor discrimination task. In addition, in situ hybridization studies indicate that the expression of several activity dependent genes is unaffected in β3GnT2−/− olfactory neurons. Conclusions Results presented here show that many odorant receptors are under-expressed in β3GnT2−/− mice and further demonstrate that additional axon subsets grow into inappropriate targets or minimally innervate glomeruli in the olfactory bulb. Odor evoked gene expression is unchanged and β3GnT2−/− mice exhibit a relatively small deficit in their ability to discriminate divergent odors. Results suggest that despite the fact that β3GnT2−/− mice have decreased AC3 activity, decreased expression of many ORs, and display many axon growth and guidance errors, odor-evoked activity in cilia of mutant olfactory neurons remains largely intact. PMID:22559903

Vascular Endothelial Growth Factor and Angiopoietin are Required for Prostate Regeneration.

PubMed Central

Wang, Gui-min; Kovalenko, Bruce; Huang, Yili; Moscatelli, David

2007-01-01

BACKGROUND The regulation of the prostate size by androgens may be partly the result of androgen effects on the prostatic vasculature. We examined the effect of changes in androgen levels on the expression of a variety of angiogenic factors in the mouse prostate and determined if vascular endothelial growth factor (VEGF)-A and the angiopoietins are involved in the vascular response to androgens. METHODS Expression of angiogenic factors in prostate was quantitated using real-time PCR at different times after castration and after administration of testosterone to castrated mice. Angiopoietins were localized in prostate by immunohistochemistry and in situ hybridization. The roles of VEGF and the angiopoietins in regeneration of the prostate were examined in mice inoculated with cells expressing soluble VEGF receptor-2 or soluble Tie-2. RESULTS Castration resulted in a decrease in VEGF-A, VEGF-B, VEGF-C, placenta growth factor, FGF-2, and FGF-8 expression after one day. In contrast, VEGF-D mRNA levels increased. No changes in angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), hepatocyte growth factor, VEGF receptor-1, VEGF receptor-2 or tie-2 mRNA levels were observed. Administration of testosterone to castrated mice had the opposite effect on expression of these angiogenic factors. Ang-2 was expressed predominately in prostate epithelial cells whereas Ang-1 was expressed in epithelium and smooth muscle. Inoculation of mice with cells expressing soluble VEGF receptor-2 or Tie-2 blocked the increase in vascular density normally observed after administration of testosterone to castrated mice. The soluble receptors also blocked the increase in prostate weight and proliferation of prostatic epithelial cells. CONCLUSION VEGF-A and angiopoietins are required for the vascular response to androgens and for the ability of the prostate to regenerate in response to androgens. PMID:17221843

Posttranscriptional mRNA processing as a mechanism for regulation of human A1 adenosine receptor expression.

PubMed Central

Ren, H; Stiles, G L

1994-01-01

The human A1 adenosine receptor gene contains six exons with exons 1, 2, 3, 4, and part of 5 representing 5' untranslated regions. Reverse transcription-PCR with exon-specific primers showed two distinct transcripts containing either exons 3, 5, and 6 or exons 4, 5, and 6, with exons 3 and 4 being mutually exclusive. No mature mRNAs containing exons 1 and 2 have been detected. All human tissues that express any A1 receptors contain mRNA with exons 4, 5, and 6. Tissues which express high levels of A1 receptors contain mRNA with exons 3, 5, and 6. Exon 4 contains two upstream ATG codons whereas exon 3 contains none. COS cells transfected with expression vectors containing exon 4 (exons 1-6, 3-6, or Ex4-6) express much lower levels of A1 receptors than vectors without exon 4 (exons 3, 5, and 6). Mutation of upstream ATG codons in exon 4 leads to 3- to 7-fold increased A1 receptor expression, up to the level seen with the construct containing exons 3, 5, and 6. Thus, in human tissues "basal" levels of A1 receptors can be expressed by use of mRNA containing exons 4, 5, and 6, but when high levels are needed, alternative transcripts with exons 3, 5, and 6 are produced. Images PMID:8197148

Importance of D1 and D2 receptor stimulation for the induction and expression of cocaine-induced behavioral sensitization in preweanling rats

PubMed Central

McDougall, Sanders A.; Rudberg, Krista N.; Veliz, Ana; Dhargalkar, Janhavi M.; Garcia, Aleesha S.; Romero, Loveth C.; Gonzalez, Ashley E.; Mohd-Yusof, Alena; Crawford, Cynthia A.

2017-01-01

The behavioral manifestations of psychostimulant-induced sensitization vary markedly between young and adult rats, suggesting that the neural mechanisms mediating this phenomenon differ across ontogeny. In this project we examined the importance of D1 and D2 receptors for the induction and expression of cocaine-induced behavioral sensitization during the preweanling period. In the behavioral experiments, rats were injected with reversible D1 and/or D2 antagonists (SCH23390 and/or raclopride) or an irreversible receptor antagonist (EEDQ) either before cocaine administration on the pretreatment day (induction) or before cocaine challenge on the test day (expression). In the EEDQ experiments, receptor specificity was assessed by using selective dopamine antagonists to protect D1 and/or D2 receptors from inactivation. Receptor binding assays showed that EEDQ caused substantial reductions in dorsal striatal D1 and D2 binding sites, while SCH23390 and raclopride fully protected D1 and D2 receptors from EEDQ-induced alkylation. Behavioral results showed that neither D1 nor D2 receptor stimulation was necessary for the induction of cocaine sensitization in preweanling rats. EEDQ disrupted the sensitization process, suggesting that another receptor type sensitive to EEDQ alkylation was necessary for the induction process. Expression of the sensitized response was prevented by an acute injection of a D1 receptor antagonist. The pattern of DA antagonist-induced effects described for preweanling rats is, with few exceptions, similar to what is observed when the same drugs are administered to adult rats. Thus, it appears that maturational changes in D1 and D2 receptor systems are not responsible for ontogenetic differences in the behavioral manifestation of cocaine sensitization. PMID:28284952

Importance of D1 and D2 receptor stimulation for the induction and expression of cocaine-induced behavioral sensitization in preweanling rats.

PubMed

McDougall, Sanders A; Rudberg, Krista N; Veliz, Ana; Dhargalkar, Janhavi M; Garcia, Aleesha S; Romero, Loveth C; Gonzalez, Ashley E; Mohd-Yusof, Alena; Crawford, Cynthia A

2017-05-30

The behavioral manifestations of psychostimulant-induced sensitization vary markedly between young and adult rats, suggesting that the neural mechanisms mediating this phenomenon differ across ontogeny. In this project we examined the importance of D1 and D2 receptors for the induction and expression of cocaine-induced behavioral sensitization during the preweanling period. In the behavioral experiments, rats were injected with reversible D1 and/or D2 antagonists (SCH23390 and/or raclopride) or an irreversible receptor antagonist (EEDQ) either before cocaine administration on the pretreatment day (induction) or before cocaine challenge on the test day (expression). In the EEDQ experiments, receptor specificity was assessed by using selective dopamine antagonists to protect D1 and/or D2 receptors from inactivation. Receptor binding assays showed that EEDQ caused substantial reductions in dorsal striatal D1 and D2 binding sites, while SCH23390 and raclopride fully protected D1 and D2 receptors from EEDQ-induced alkylation. Behavioral results showed that neither D1 nor D2 receptor stimulation was necessary for the induction of cocaine sensitization in preweanling rats. EEDQ disrupted the sensitization process, suggesting that another receptor type sensitive to EEDQ alkylation was necessary for the induction process. Expression of the sensitized response was prevented by an acute injection of a D1 receptor antagonist. The pattern of DA antagonist-induced effects described for preweanling rats is, with few exceptions, similar to what is observed when the same drugs are administered to adult rats. Thus, it appears that maturational changes in D1 and D2 receptor systems are not responsible for ontogenetic differences in the behavioral manifestation of cocaine sensitization. Copyright © 2017 Elsevier B.V. All rights reserved.

Local expression of interferon-alpha and interferon receptors in cervical intraepithelial neoplasia.

PubMed

Tirone, Nelson R; Peghini, Bethanea C; Barcelos, Ana Cristina M; Murta, Eddie F C; Michelin, Marcia A

2009-12-01

The present study evaluated mRNA expression of interferon-alpha (IFN-alpha), IFN-alpha receptor subunits (IFNAR-1 and IFNAR-2) and an IFN-stimulated gene encoding the enzyme 2',5'-oligoadenylate synthetase (2'5'OAS) in biopsies on patients with varying grades of cervical intraepithelial neoplasia (CIN I, II and III). Uterine cervix biopsies were collected from women with CIN I, II and III (n = 28) and controls without CIN lesions or human papilloma virus (HPV) infection (n = 17). The presence of high and low-risk HPV DNA was determined using hybrid capture. The mRNA levels of IFNAR-1, IFNAR-2, IFN-alpha and 2'5'OAS were determined by RT-PCR with specific primers. The control group exhibited a greater frequency of IFNAR-1 expression (10/17; 58.3%) than the CIN samples (4/28; 14.2%) (P = 0.0018), while, the expression of IFNAR-2 was also greater in the control samples (11/17; 64.7%) than in the patients with lesions (2/28; 7.1%) (P = 0.0018). Importantly, simultaneous expression of both receptors was observed only in the control group (8/17; 47.0%) (P = 0.0001). Among the CIN samples, there was one case of low expression of mRNA of IFNAR-1 and IFNAR-2. IFN-alpha was present in 14.2% (4/28) of the CIN samples but was not expressed in the control group. mRNA 2'5'OAS were expressed in 28.5% (8/28) of the CIN samples and 11.7% (2/17) of the control samples (not statistically significant). Fifty percent (14/28) of the CIN samples were positive for HPV DNA. Cervical biopsy samples from control women or those without neoplasia or HPV infection displayed higher IFN-alpha receptor expression than those with CIN, while simultaneous expression of both IFN-alpha receptor subunits was found only in the control group. There was no significant difference in mRNA expression of IFN-alpha and 2'5'OAS between the control and CIN groups. Then we concluded that the samples obtained from patients with CIN present low levels of the IFN-alpha receptor mRNA.

Human T lymphocytes express N-methyl-D-aspartate receptors functionally active in controlling T cell activation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miglio, Gianluca; Varsaldi, Federica; Lombardi, Grazia

2005-12-30

The aim of this study was to investigate the expression and the functional role of N-methyl-D-aspartate (NMDA) receptors in human T cells. RT-PCR analysis showed that human resting peripheral blood lymphocytes (PBL) and Jurkat T cells express genes encoding for both NR1 and NR2B subunits: phytohemagglutinin (PHA)-activated PBL also expresses both these genes and the NR2A and NR2D genes. Cytofluorimetric analysis showed that NR1 expression increases as a consequence of PHA (10 {mu}g/ml) treatment. D-(-)-2-Amino-5-phosphonopentanoic acid (D-AP5), and (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine [(+)-MK 801], competitive and non-competitive NMDA receptor antagonists, respectively, inhibited PHA-induced T cell proliferation, whereas they did not affect IL-2 (10more » U/ml)-induced proliferation of PHA blasts. These effects were due to the prevention of T cell activation (inhibition of cell aggregate formation and CD25 expression), but not to cell cycle arrest or death. These results demonstrate that human T lymphocytes express NMDA receptors, which are functionally active in controlling cell activation.« less

Serotonin 2c receptors in pro-opiomelanocortin neurons regulate energy and glucose homeostasis

USDA-ARS?s Scientific Manuscript database

Energy and glucose homeostasis are regulated by central serotonin 2C receptors. These receptors are attractive pharmacological targets for the treatment of obesity; however, the identity of the serotonin 2C receptor-expressing neurons that mediate the effects of serotonin and serotonin 2C receptor a...

[New methods of patient selection for improved anticholinergic therapy].

PubMed

Neuhaus, J; Schwalenberg, T; Schlichting, N; Schulze, M; Horn, L-C; Stolzenburg, J-U

2007-09-01

M3-specific inhibitors are currently preferred for anticholinergic therapy of OAB. However, not all of the patients profit from this regimen. This might reflect a heterogeneity of the patient group. The aim of this work is to define subgroups of patients with specific alterations of receptor expression and to profile the receptor expression individually. These receptor profiles might be used for the development of evidence-based "tailored" therapies. Detrusor probes from bladder carcinoma patients (BCa, n=9 F, n=7 male) and interstitial cystitis patients (IC, n=9 female) were examined using confocal immunofluorescence and PCR. M2, M3, P2X1-3, and H1-3 mRNAs were demonstrated in detrusor tissue. As revealed by immunofluorescence, the M2 receptor expression was significantly higher in female compared to male BCa tissues. In addition, the M2 receptor was further upregulated in IC vs BCa in female detrusor. IC patients showed specific alterations of their receptor profile. Individual receptor profiles might be used to optimize medicinal therapies.

Attenuation of Cocaine-Induced Conditioned Place Preference and Motor Activity via Cannabinoid CB2 Receptor Agonism and CB1 Receptor Antagonism in Rats

PubMed Central

Delis, Foteini; Polissidis, Alexia; Poulia, Nafsika; Justinova, Zuzana; Nomikos, George G.; Goldberg, Steven R.

2017-01-01

Abstract Background: Studies have shown the involvement of cannabinoid (CB) receptors in the behavioral and neurobiological effects of psychostimulants. Most of these studies have focused on the role of CB1 receptors in the psychostimulant effects of cocaine, while very few have investigated the respective role of CB2 receptors. Further studies are warranted to elucidate the extent of CB receptor involvement in the expression of cocaine-induced effects. Methods: The role of CB1 and CB2 receptors in the rewarding and motor properties of cocaine was assessed in conditioned place preference, conditioned motor activity, and open field activity in rats. Results: The CB1 receptor antagonist rimonabant (3 mg/kg) decreased the acquisition and the expression of conditioned place preference induced by cocaine (20 mg/kg). Rimonabant inhibited cocaine-elicited conditioned motor activity when administered during the expression of cocaine-induced conditioned place preference. Rimonabant decreased ambulatory and vertical activity induced by cocaine. The CB2 receptor agonist JWH-133 (10 mg/kg) decreased the acquisition and the expression of cocaine-induced conditioned place preference. JWH-133 inhibited cocaine-elicited conditioned motor activity when administered during the acquisition and the expression of cocaine-induced conditioned place preference. JWH-133 decreased ambulatory activity and abolished vertical activity induced by cocaine. The effects of JWH-133 on cocaine conditioned and stimulated responses were abolished when the CB2 receptor antagonist/inverse agonist AM630 (5 mg/kg) was preadministered. Conclusions: Cannabinoid CB1 and CB2 receptors modulate cocaine-induced rewarding behavior and appear to have opposite roles in the regulation of cocaine’s reinforcing and psychomotor effects. PMID:27994006

Adrenocorticotropin receptors: Functional expression from rat adrenal mRNA in Xenopus laevis oocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mertz, L.M.; Catt, K.J.

1991-10-01

The adrenocorticotropin (ACTH) receptor, which binds corticotropin and stimulates adenylate cyclase and steroidogenesis in adrenocortical cells, was expressed in Xenopus laevis oocytes microinjected with rat adrenal poly(A){sup +} RNA. Expression of the ACTH receptor in individual stage 5 and 6 oocytes was monitored by radioimmunoassay of ligand-stimulated cAMP production. Injection of 5-40 ng of adrenal mRNA caused dose-dependent increases in ACTH-responsive cAMP production. Size fractionation of rat adrenal poly(A){sup +}RNA by sucrose density-gradient centrifugation revealed that mRNA encoding the ACTH receptor was present in the 1.1-to 2.0-kilobase fraction. These data indicate that ACTH receptors can be expressed from adrenal mRNAmore » in Xenopus oocytes and are fully functional in terms of ligand specificity and signal generation. The extracellular cAMP response to ACTH is a sensitive and convenient index of receptor expression. This system should permit more complete characterization and expression cloning of the ACTH receptor.« less

Increased Eps15 homology domain 1 and RAB11FIP3 expression regulate breast cancer progression via promoting epithelial growth factor receptor recycling.

PubMed

Tong, Dandan; Liang, Ya-Nan; Stepanova, A A; Liu, Yu; Li, Xiaobo; Wang, Letian; Zhang, Fengmin; Vasilyeva, N V

2017-02-01

Recent research indicates that the C-terminal Eps15 homology domain 1 is associated with epithelial growth factor receptor-mediated endocytosis recycling in non-small-cell lung cancer. The aim of this study was to determine the clinical significance of Eps15 homology domain 1 gene expression in relation to phosphorylation of epithelial growth factor receptor expression in patients with breast cancer. Primary breast cancer samples from 306 patients were analyzed for Eps15 homology domain 1, RAB11FIP3, and phosphorylation of epithelial growth factor receptor expression via immunohistochemistry. The clinical significance was assessed via a multivariate Cox regression analysis, Kaplan-Meier curves, and the log-rank test. Eps15 homology domain 1 and phosphorylation of epithelial growth factor receptor were upregulated in 60.46% (185/306) and 53.92% (165/306) of tumor tissues, respectively, as assessed by immunohistochemistry. The statistical correlation analysis indicated that Eps15 homology domain 1 overexpression was positively correlated with the increases in phosphorylation of epithelial growth factor receptor ( r = 0.242, p < 0.001) and RAB11FIP3 ( r = 0.165, p = 0.005) expression. The multivariate Cox proportional hazard model analysis demonstrated that the expression of Eps15 homology domain 1 alone is a significant prognostic marker of breast cancer for the overall survival in the total, chemotherapy, and human epidermal growth factor receptor 2 (-) groups. However, the use of combined expression of Eps15 homology domain 1 and phosphorylation of epithelial growth factor receptor markers is more effective for the disease-free survival in the overall population, chemotherapy, and human epidermal growth factor receptor 2 (-) groups. Moreover, the combined markers are also significant prognostic markers of breast cancer in the human epidermal growth factor receptor 2 (+), estrogen receptor (+), and estrogen receptor (-) groups. Eps15 homology domain 1 has a tumor suppressor function, and the combined marker of Eps15 homology domain 1/phosphorylation of epithelial growth factor receptor expression was identified as a better prognostic marker in breast cancer diagnosis. Furthermore, RAB11FIP3 combines with Eps15 homology domain 1 to promote the endocytosis recycling of phosphorylation of epithelial growth factor receptor.

Prostaglandin E2 mediates growth arrest in NFS-60 cells by down-regulating interleukin-6 receptor expression.

PubMed

de Silva, Kumudika I; Daud, Asif N; Deng, JiangPing; Jones, Stephen B; Gamelli, Richard L; Shankar, Ravi

2003-02-15

Interleukin-6 (IL-6), a potent myeloid mitogen, and the immunosuppressive prostanoid prostaglandin E2 (PGE2) are elevated following thermal injury and sepsis. We have previously demonstrated that bone marrow myeloid commitment shifts toward monocytopoiesis and away from granulocytopoiesis during thermal injury and sepsis and that PGE2 plays a central role in this alteration. Here we investigated whether PGE2 can modulate IL-6-stimulated growth in the promyelocytic cell line, NFS-60, by down-regulating IL-6 receptor (IL-6r) expression. Exposure of NFS-60 cells to PGE2 suppressed IL-6-stimulated proliferation as well as IL-6r expression. Receptor down-regulation is functionally significant since IL-6-induced signal transduction through activators of transcription (STAT)-3 is also decreased. Down-regulation of IL-6r correlated with the ability of PGE2 to arrest cells in the G0/G1 phase of the cell cycle. PGE2 appears to signal through EP2 receptors. Butaprost (EP2 agonist) but not sulprostone (EP3 agonist) inhibited IL-6-stimulated proliferation. In addition, an EP2 antagonist (AH6809) alleviated the anti-proliferative effects of PGE2. NFS-60 cells express predominantly EP2 and EP4 receptors. While PGE2 down-regulated both the IL-6r protein and mRNA expression, it had no influence on EP2 or EP4 mRNA expression. The present study demonstrates that PGE2 is a potent down-regulator of IL-6r expression and thus may provide a mechanistic explanation for the granulocytopenia seen in thermal injury and sepsis.

Selective Deletion of GRK2 Alters Psychostimulant-Induced Behaviors and Dopamine Neurotransmission

PubMed Central

Daigle, Tanya L; Ferris, Mark J; Gainetdinov, Raul R; Sotnikova, Tatyana D; Urs, Nikhil M; Jones, Sara R; Caron, Marc G

2014-01-01

GRK2 is a G protein-coupled receptor kinase (GRK) that is broadly expressed and is known to regulate diverse types of receptors. GRK2 null animals exhibit embryonic lethality due to a severe developmental heart defect, which has precluded the study of this kinase in the adult brain. To elucidate the specific role of GRK2 in the brain dopamine (DA) system, we used a conditional gene knockout approach to selectively delete GRK2 in DA D1 receptor (D1R)-, DA D2 receptor (D2R)-, adenosine 2A receptor (A2AR)-, or DA transporter (DAT)-expressing neurons. Here we show that select GRK2-deficient mice display hyperactivity, hyposensitivity, or hypersensitivity to the psychomotor effects of cocaine, altered striatal signaling, and DA release and uptake. Mice with GRK2 deficiency in D2R-expressing neurons also exhibited increased D2 autoreceptor activity. These findings reveal a cell-type-specific role for GRK2 in the regulation of normal motor behavior, sensitivity to psychostimulants, dopamine neurotransmission, and D2 autoreceptor function. PMID:24776686

Enhanced resistance to soybean cyst nematode Heterodera glycines in transgenic soybean by silencing putative CLE receptors.

PubMed

Guo, Xiaoli; Chronis, Demosthenis; De La Torre, Carola M; Smeda, John; Wang, Xiaohong; Mitchum, Melissa G

2015-08-01

CLE peptides are small extracellular proteins important in regulating plant meristematic activity through the CLE-receptor kinase-WOX signalling module. Stem cell pools in the SAM (shoot apical meristem), RAM (root apical meristem) and vascular cambium are controlled by CLE signalling pathways. Interestingly, plant-parasitic cyst nematodes secrete CLE-like effector proteins, which act as ligand mimics of plant CLE peptides and are required for successful parasitism. Recently, we demonstrated that Arabidopsis CLE receptors CLAVATA1 (CLV1), the CLAVATA2 (CLV2)/CORYNE (CRN) heterodimer receptor complex and RECEPTOR-LIKE PROTEIN KINASE 2 (RPK2), which transmit the CLV3 signal in the SAM, are required for perception of beet cyst nematode Heterodera schachtii CLEs. Reduction in nematode infection was observed in clv1, clv2, crn, rpk2 and combined double and triple mutants. In an effort to develop nematode resistance in an agriculturally important crop, orthologues of Arabidopsis receptors including CLV1, CLV2, CRN and RPK2 were identified from soybean, a host for the soybean cyst nematode Heterodera glycines. For each of the receptors, there are at least two paralogues in the soybean genome. Localization studies showed that most receptors are expressed in the root, but vary in their level of expression and spatial expression patterns. Expression in nematode-induced feeding cells was also confirmed. In vitro direct binding of the soybean receptors with the HgCLE peptide was analysed. Knock-down of the receptors in soybean hairy roots showed enhanced resistance to SCN. Our findings suggest that targeted disruption of nematode CLE signalling may be a potential means to engineer nematode resistance in crop plants. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Angiotensin II AT1 receptor alters ACE2 activity, eNOS expression and CD44-hyaluronan interaction in rats with hypertension and myocardial fibrosis.

PubMed

Bai, Feng; Pang, Xue-Fen; Zhang, Li-Hui; Wang, Ning-Ping; McKallip, Robert J; Garner, Ronald E; Zhao, Zhi-Qing

2016-05-15

This study tested the hypothesis that angiotensin II (Ang II) AT1 receptor is involved in development of hypertension and cardiac fibrosis via modifying ACE2 activity, eNOS expression and CD44-hyaluronan interaction. Male Sprague-Dawley rats were subjected to Ang II infusion (500ng/kg/min) using osmotic minipumps up to 4weeks and the AT1 receptor blocker, telmisartan was administered by gastric gavage (10mg/kg/day) during Ang II infusion. Our results indicated that Ang II enhances AT1 receptor, downregulates AT2 receptor, ACE2 activity and eNOS expression, and increases CD44 expression and hyaluronidase activity, an enzyme for hyaluronan degradation. Further analyses revealed that Ang II increases blood pressure and augments vascular/interstitial fibrosis. Comparison of the Ang II group, treatment with telmisartan significantly increased ACE2 activity and eNOS expression in the intracardiac vessels and intermyocardium. These changes occurred in coincidence with decreased blood pressure. Furthermore, the locally-expressed AT1 receptor was downregulated, as evidenced by an increased ratio of the AT2 over AT1 receptor (1.4±0.4% vs. 0.4±0.1% in Ang II group, P<0.05). Along with these modulations, telmisartan inhibited membrane CD44 expression and hyaluronidase activity, decreased populations of macrophages and myofibroblasts, and reduced expression of TGFβ1 and Smads. Collagen I synthesis and tissue fibrosis were attenuated as demonstrated by the less extensive collagen-rich area. These results suggest that the AT1 receptor is involved in development of hypertension and cardiac fibrosis. Selective activating ACE2/eNOS and inhibiting CD44/HA interaction might be considered as the therapeutic targets for attenuating Ang II induced deleterious cardiovascular effects. Copyright © 2016 Elsevier Inc. All rights reserved.

Structure and function of the amygdaloid NPY system: NPY Y2 receptors regulate excitatory and inhibitory synaptic transmission in the centromedial amygdala.

PubMed

Wood, J; Verma, D; Lach, G; Bonaventure, P; Herzog, H; Sperk, G; Tasan, R O

2016-09-01

The amygdala is essential for generating emotional-affective behaviors. It consists of several nuclei with highly selective, elaborate functions. In particular, the central extended amygdala, consisting of the central amygdala (CEA) and the bed nucleus of the stria terminalis (BNST) is an essential component actively controlling efferent connections to downstream effectors like hypothalamus and brain stem. Both, CEA and BNST contain high amounts of different neuropeptides that significantly contribute to synaptic transmission. Among these, neuropeptide Y (NPY) has emerged as an important anxiolytic and fear-reducing neuromodulator. Here, we characterized the expression, connectivity and electrophysiological function of NPY and Y2 receptors within the CEA. We identified several NPY-expressing neuronal populations, including somatostatin- and calretinin-expressing neurons. Furthermore, in the main intercalated nucleus, NPY is expressed primarily in dopamine D1 receptor-expressing neurons but also in interspersed somatostatin-expressing neurons. Interestingly, NPY neurons did not co-localize with the Y2 receptor. Retrograde tract tracing experiments revealed that NPY neurons reciprocally connect the CEA and BNST. Functionally, the Y2 receptor agonist PYY3-36, reduced both, inhibitory as well as excitatory synaptic transmission in the centromedial amygdala (CEm). However, we also provide evidence that lack of NPY or Y2 receptors results in increased GABA release specifically at inhibitory synapses in the CEm. Taken together, our findings suggest that NPY expressed by distinct populations of neurons can modulate afferent and efferent projections of the CEA via presynaptic Y2 receptors located at inhibitory and excitatory synapses.

Detection of receptor ligands by monitoring selective stabilization of a Renilla luciferase-tagged, constitutively active mutant, G-protein-coupled receptor

PubMed Central

Ramsay, Douglas; Bevan, Nicola; Rees, Stephen; Milligan, Graeme

2001-01-01

The wild-type β2-adrenoceptor and a constitutively active mutant of this receptor were C-terminally tagged with luciferase from the sea pansy Renilla reniformis. C-terminal addition of Renilla luciferase did not substantially alter the levels of expression of either form of the receptor, the elevated constitutive activity of the mutant β2-adrenoceptor nor the capacity of isoprenaline to elevate cyclic AMP levels in intact cells expressing these constructs. Treatment of cells expressing constitutively active mutant β2-adrenoceptor-Renilla luciferase with antagonist/inverse agonist ligands resulted in upregulation of levels of this polypeptide which could be monitored by the elevated luciferase activity. The pEC50 for ligand-induced luciferase upregulation and ligand affinity to bind the receptor were highly correlated. Similar upregulation could be observed following sustained treatment with agonist ligands. These effects were only observed at a constitutively active mutant of the β2-adrenoceptor. Co-expression of the wild-type β2-adrenoceptor C-terminally tagged with the luciferase from Photinus pyralis did not result in ligand-induced upregulation of the levels of activity of this luciferase. Co-expression of the constitutively active mutant β2-adrenoceptor-Renilla luciferase and an equivalent mutant of the α1b-adrenoceptor C-terminally tagged with green fluorescent protein allowed pharmacological selectivity of adrenoceptor antagonists to be demonstrated. This approach offers a sensitive and convenient means, which is amenable to high throughput analysis, to monitor ligand binding to a constitutively active mutant receptor. As no prior knowledge of receptor ligands is required this approach may be suitable to identify ligands at orphan G protein-coupled receptors. PMID:11350868

A role for tachykinins in female mouse and rat reproductive function.

PubMed

Pintado, C Oscar; Pinto, Francisco M; Pennefather, Jocelyn N; Hidalgo, Agustin; Baamonde, Ana; Sanchez, Teresa; Candenas, M Luz

2003-09-01

Tachykinins may be involved in reproduction. A reverse transcription-polymerase chain reaction assay was used to analyze the expression of tachykinins and tachykinin receptors in different types of reproductive cells from mice. The preprotachykinin (PPT) genes, PPT-A, PPT-B and PPT-C, that encode substance P/neurokinin A, neurokinin B, and hemokinin-1, respectively, and the genes that encode the tachykinin NK1, NK2, and NK3 receptors were all expressed, at different levels, in the uterus of superovulated, unfertilized mice. The mRNA of neprilysin (NEP), the main enzyme involved in tachykinin metabolism, was also expressed in the uterus. Isolated cumulus granulosa cells expressed PPT-A, PPT-B, PPT-C, and NEP and low levels of the tachykinin NK1 and NK2 receptors. Mouse oocytes expressed PPT-A and -B mRNA transcripts. A low expression of the three tachykinin receptors was observed but PPT-C and NEP were undetectable. Two- and 8- to 16-cell mouse embryos expressed only a low-abundance transcript corresponding to the NK1 receptor. However, the mRNAs of PPT-B, PPT-C and NEP appeared in blastocyst-stage embryos. A low-abundance transcript corresponding to the NK2 receptor was the only target gene detected in mice sperm. Female mice or rats treated neonatally with capsaicin showed a reduced fertility. A reduction in litter size was observed in female rats treated in vivo with the tachykinin NK3 receptor antagonist SR 142801. These data show that tachykinins of both neuronal and nonneuronal origin are differentially expressed in various types of reproductive cells and may play a role in female reproductive function.

Transcriptional profiling of striatal neurons in response to single or concurrent activation of dopamine D2, adenosine A(2A) and metabotropic glutamate type 5 receptors: focus on beta-synuclein expression.

PubMed

Canela, Laia; Selga, Elisabet; García-Martínez, Juan Manuel; Amaral, Olavo B; Fernández-Dueñas, Víctor; Alberch, Jordi; Canela, Enric I; Franco, Rafael; Noé, Véronique; Lluís, Carme; Ciudad, Carlos J; Ciruela, Francisco

2012-10-25

G protein-coupled receptor oligomerization is a concept which is changing the understanding of classical pharmacology. Both, oligomerization and functional interaction between adenosine A(2A,) dopamine D(2) and metabotropic glutamate type 5 receptors have been demonstrated in the striatum. However, the transcriptional consequences of receptors co-activation are still unexplored. We aim here to determine the changes in gene expression of striatal primary cultured neurons upon isolated or simultaneous receptor activation. Interestingly, we found that 95 genes of the total analyzed (15,866 transcripts and variants) changed their expression in response to simultaneous stimulation of all three receptors. Among these genes, we focused on the β-synuclein (β-Syn) gene (SCNB). Quantitative PCR verified the magnitude and direction of change in expression of SCNB. Since β-Syn belongs to the homologous synuclein family and may be considered a natural regulator of α-synuclein (α-Syn), it has been proposed that β-Syn might act protectively against α-Syn neuropathology. Copyright © 2012 Elsevier B.V. All rights reserved.

Angiotensin II attenuates NMDA receptor-mediated neuronal cell death and prevents the associated reduction in Bcl-2 expression.

PubMed

Schelman, William R; Andres, Robert; Ferguson, Paul; Orr, Brent; Kang, Evan; Weyhenmeyer, James A

2004-09-10

While angiotensin II (Ang II) plays a major role in the regulation of blood pressure, fluid homeostasis and neuroendocrine function, recent studies have also implicated the peptide hormone in cell growth, differentiation and apoptosis. In support of this, we have previously demonstrated that Ang II attenuates N-methyl-D-aspartate (NMDA) receptor signaling [Molec. Brain Res. 48 (1997) 197]. To further examine the modulatory role of Ang II on NMDA receptor function, we investigated the effect of angiotensin receptor (AT) activation on NMDA-mediated cell death and the accompanying decrease in Bcl-2 expression. The viability of differentiated N1E-115 and NG108-15 neuronal cell lines was reduced following exposure to NMDA in a dose-dependent manner. MTT analysis (mitochondrial integrity) revealed a decrease in cell survival of 49.4+/-12.3% in NG108 cells and 79.9+/-6.8% in N1E cells following treatment with 10 mM NMDA for 20 h. Cytotoxicity in N1E cells was inhibited by the noncompetitive NMDA receptor antagonist, MK-801. Further, NMDA receptor-mediated cell death in NG108 cells was attenuated by treatment with Ang II. The Ang II effect was inhibited by both AT1 and AT2 receptor antagonists, losartan and PD123319, respectively, suggesting that both receptor subtypes may play a role in the survival effect of Ang II. Since it has been shown that activation of NMDA receptors alters the expression of Bcl-2 family proteins, Western blot analysis was performed in N1E cells to determine whether Ang II alters the NMDA-induced changes in Bcl-2 expression. A concentration-dependent decrease of intracellular Bcl-2 protein levels was observed following treatment with NMDA, and this reduction was inhibited by MK801. Addition of Ang II suppressed the NMDA receptor-mediated reduction in Bcl-2. The Ang II effect on NMDA-mediated changes in Bcl-2 levels was blocked by PD123319, but was not significantly changed by losartan, suggesting AT2 receptor specificity. Taken together, these results suggest that Ang II attenuates NMDA receptor-mediated neurotoxicity and that this effect may be due, in part, to an alteration in Bcl-2 expression.

Expression and significance of Tie-1 and Tie-2 receptors, and angiopoietins-1, 2 and 4 in colorectal adenocarcinoma: Immunohistochemical analysis and correlation with clinicopathological factors

PubMed Central

Nakayama, Toshiyuki; Hatachi, Go; Wen, Chun-Yang; Yoshizaki, Ayumi; Yamazumi, Kazuyuki; Niino, Daisuke; Sekine, Ichiro

2005-01-01

AIM: There is strong evidence that tyrosine kinases are involved in the regulation of tumor progression, cellular growth and differentiation. Recently, many kinds of tyrosine kinase receptors have been reported, among them Tie-1 and Tie-2 receptors constitute a major class. Angiopoietin (Ang)-1 is known as a ligand of Tie-2 tyrosine kinase receptor. The objective of this study was to establish a comprehensive Tie-1 and Tie-2 and Ang-1, 2 and 4 expression profile in human colorectal adenocarcinomas. METHODS: We examined 96 cases of surgically resected human colorectal adenocarcinoma by immunohistochemistry and investigated the statistical correlation between the expressions of Ties and Angs and clinicopathological factors. RESULTS: Among the 96 cases of adenocarcinoma, 87 (90.6%), 92 (95.8%), 83 (86.5%), 89 (92.7%), and 76 cases (79.2%) showed positive staining in the cytoplasm of carcinoma cells for the Tie-1 and Tie-2 and Ang-1, 2 and 4 proteins, respectively. Histologically, the expressions of Ties and Angs were variable. The expressions of Ties and Angs were correlated with several clinicopathological factors, but did not correlate with the presence of lymph node metastasis. Ties and Angs were highly expressed in human colorectal adenocarcinoma cells. CONCLUSION: These findings suggest that the Tie-Ang receptor-ligand complex is one of the factors involved in the cellular differentiation and progression of human colorectal adenocarcinoma. PMID:15742397

Channel-Opening Kinetic Mechanism of Wild-Type GluK1 Kainate Receptors and a C-Terminal Mutant

PubMed Central

Han, Yan; Wang, Congzhou; Park, Jae Seon; Niu, Li

2012-01-01

GluK1 is a kainate receptor subunit in the ionotropic glutamate receptor family and can form functional channels when expressed, for instance, in HEK-293 cells. However, the channel-opening mechanism of GluK1 is poorly understood. One major challenge to studying the GluK1 channel is its apparent low surface expression, which results in a low whole-cell current response even to a saturating concentration of agonist. The low surface expression is thought to be contributed by an endoplasmic reticulum (ER) retention signal sequence. When this sequence motif is present as in the wild-type GluK1-2b C-terminus, the receptor is significantly retained in the ER. Conversely, when this sequence is lacking, as in wild-type GluK1-2a (i.e., a different alternatively spliced isoform at the C-terminus) and in a GluK1-2b mutant (i.e., R896A, R897A, R900A and K901A) that disrupts the ER retention signal, there is higher surface expression and greater whole-cell current response. Here we characterize the channel-opening kinetic mechanism for these three GluK1 receptors expressed in HEK-293 cells by using a laser-pulse photolysis technique. Our results show that the wild-type GluK1-2a, wild-type GluK1-2b and the mutant GluK1-2b have identical channel-opening and channel-closing rate constants. These results indicate that the C-terminal ER retention signal sequence, which affects receptor trafficking/expression, does not affect channel-gating properties. Furthermore, as compared with the GluK2 kainate receptor, the GluK1 channel is faster to open, close, and desensitize by at least two-fold, yet the EC50 value of GluK1 is similar to that of GluK2. PMID:22191429

ErbB2 and EGFR are downmodulated during the differentiation of 3T3-L1 preadipocytes.

PubMed

Pagano, Eleonora; Calvo, Juan Carlos

2003-10-15

The expression of receptors belonging to the epidermal growth factor receptor subfamily has been largely studied these last years in epithelial cells mainly as involved in cell proliferation and malignant progression. Although much work has focused on the role of these growth factor receptors in the differentiation of a variety of tissues, there is little information in regards to normal stromal cells. We investigated erbB2 expression in the murine fibroblast cell line Swiss 3T3L1, which naturally or hormonally induced undergoes adipocyte differentiation. We found that the Swiss 3T3-L1 fibroblasts express erbB2, in addition to EGFR, and in a quantity comparable to or even greater than the breast cancer cell line T47D. Proliferating cells increased erbB2 and EGFR levels when reaching confluence up to 4- and 10-fold, respectively. This expression showed a significant decrease when growth-arrested cells were stimulated to differentiate with dexamethasone and isobutyl-methylxanthine. Differentiated cells presented a decreased expression of both erbB2 and EGFR regardless of whether the cells were hormonally or spontaneously differentiated. EGF stimulation of serum-starved cells increased erbB2 tyrosine phosphorylation and retarded erbB2 migration in SDS-PAGE, suggesting receptor association and activation. Heregulin-alpha1 and -beta1, two EGF related factors, had no effect on erbB2 or EGFR phosphorylation. Although 3T3-L1 cells expressed heregulin, its specific receptors, erbB3 and erbB4, were not found. This is the first time in which erbB2 is reported to be expressed in an adipocytic cell line which does not depend on non EGF family growth factors (thyroid hormone, growth hormone, etc.) to accomplish adipose differentiation. Since erbB2 and EGFR expression were downmodulated as differentiation progressed it is conceivable that a mechanism of switching from a mitogenic to a differentiating signaling pathway may be involved, through regulation of the expression of these growth factor receptors. Copyright 2003 Wiley-Liss, Inc.

Smooth muscle neurokinin-2 receptors mediate contraction in human saphenous veins.

PubMed

Mechiche, Hakima; Grassin-Delyle, Stanislas; Pinto, Francisco M; Buenestado, Amparo; Candenas, Luz; Devillier, Philippe

2011-05-01

Substance P (SP) and neurokinin A (NKA) are members of the tachykinin peptides family. SP causes endothelial-dependant relaxation but the contractile response to tachykinins in human vessels remains unknown. The objective was to assess the expression and the contractile effects of tachykinins and their receptors in human saphenous veins (SV). Tachykinin expression was assessed with RT-PCR, tachykinin receptors expression with RT-PCR and immunohistochemistry, and functional studies were performed in organ bath. Transcripts of all tachykinin and tachykinin receptor genes were found in SV. NK(1)-receptors were localized in both endothelial and smooth muscle layers of undistended SV, whereas they were only found in smooth muscle layers of varicose SV. The expression of NK(2)- and NK(3)-receptors was limited to the smooth muscle in both preparations. NKA induced concentration-dependent contractions in about half the varicose SV. Maximum effect reached 27.6±5.5% of 90 mM KCl and the pD(2) value was 7.3±0.2. NKA also induced the contraction of undistended veins from bypass and did not cause the relaxation of these vessels after precontraction. The NK(2)-receptor antagonist SR48968 abolished the contraction induced by NKA, and a rapid desensitization of the NK(2)-receptor was observed. In varicose SV, the agonists specific to NK(1)- or NK(3)-receptors did not cause either contraction or relaxation. The stimulation of smooth muscle NK(2)-receptors can induce the contraction of human SV. As SV is richly innervated, tachykinins may participate in the regulation of the tone in this portion of the low pressure vascular system. Copyright © 2011 Elsevier Ltd. All rights reserved.

Expression and Functional Pathway Analysis of Nuclear Receptor NR2F2 in Ovarian Cancer

PubMed Central

Hawkins, Shannon M.; Loomans, Holli A.; Wan, Ying-Wooi; Ghosh-Choudhury, Triparna; Coffey, Donna; Xiao, Weimin; Liu, Zhandong; Sangi-Haghpeykar, Haleh

2013-01-01

Context: Recent evidence implicates the orphan nuclear receptor, nuclear receptor subfamily 2, group F, member 2 (NR2F2; chicken ovalbumin upstream promoter-transcription factor II) as both a master regulator of angiogenesis and an oncogene in prostate and other human cancers. Objective: The objective of the study was to determine whether NR2F2 plays a role in ovarian cancer and dissect its potential mechanisms of action. Design, Setting, and Patients: We examined NR2F2 expression in healthy ovary and ovarian cancers using quantitative PCR and immunohistochemistry. NR2F2 expression was targeted in established ovarian cancer cell lines to assess the impact of dysregulated NR2F2 expression in the epithelial compartment of ovarian cancers. Results: Our results indicate that NR2F2 is robustly expressed in the stroma of healthy ovary with little or no expression in epithelia lining the ovarian surface, clefts, or crypts. This pattern of NR2F2 expression was markedly disrupted in ovarian cancers, in which decreased levels of stromal expression and ectopic epithelial expression were frequently observed. Ovarian cancers with the most disrupted patterns of NR2F2 were associated with significantly shorter disease-free interval by Kaplan-Meier analysis. Targeting NR2F2 expression in established ovarian cancer cell lines enhanced apoptosis and increased proliferation. In addition, we found that NR2F2 regulates the expression of NEK2, RAI14, and multiple other genes involved in the cell cycle, suggesting potential pathways by which dysregulated expression of NR2F2 impacts ovarian cancer. Conclusions: These results uncover novel roles for NR2F2 in ovarian cancer and point to a unique scenario in which a single nuclear receptor plays potentially distinct roles in the stromal and epithelial compartments of the same tissue. PMID:23690307

Effect of long-term actual spaceflight on the expression of key genes encoding serotonin and dopamine system

NASA Astrophysics Data System (ADS)

Popova, Nina; Shenkman, Boris; Naumenko, Vladimir; Kulikov, Alexander; Kondaurova, Elena; Tsybko, Anton; Kulikova, Elisabeth; Krasnov, I. B.; Bazhenova, Ekaterina; Sinyakova, Nadezhda

The effect of long-term spaceflight on the central nervous system represents important but yet undeveloped problem. The aim of our work was to study the effect of 30-days spaceflight of mice on Russian biosatellite BION-M1 on the expression in the brain regions of key genes of a) serotonin (5-HT) system (main enzymes in 5-HT metabolism - tryptophan hydroxylase-2 (TPH-2), monoamine oxydase A (MAO A), 5-HT1A, 5-HT2A and 5-HT3 receptors); b) pivotal enzymes in DA metabolism (tyrosine hydroxylase, COMT, MAO A, MAO B) and D1, D2 receptors. Decreased expression of genes encoding the 5-HT catabolism (MAO A) and 5-HT2A receptor in some brain regions was shown. There were no differences between “spaceflight” and control mice in the expression of TPH-2 and 5-HT1A, 5-HT3 receptor genes. Significant changes were found in genetic control of DA system. Long-term spaceflight decreased the expression of genes encoding the enzyme in DA synthesis (tyrosine hydroxylase in s.nigra), DA metabolism (MAO B in the midbrain and COMT in the striatum), and D1 receptor in hypothalamus. These data suggested that 1) microgravity affected genetic control of 5-HT and especially the nigrostriatal DA system implicated in the central regulation of muscular tonus and movement, 2) the decrease in the expression of genes encoding key enzyme in DA synthesis, DA degradation and D1 receptor contributes to the movement impairment and dyskinesia produced by the spaceflight. The study was supported by Russian Foundation for Basic Research grant No. 14-04-00173.

Effects of volatile solvents on recombinant N-methyl-D-aspartate receptors expressed in Xenopus oocytes

PubMed Central

Cruz, Silvia L; Balster, Robert L; Woodward, John J

2000-01-01

We have previously shown that toluene dose-dependently inhibits recombinant N-methyl-D-aspartate (NMDA) receptors at micromolar concentrations. This inhibition was rapid, almost complete and reversible. The NR1/2B combination was the most sensitive receptor subtype tested with an IC50 value for toluene of 0.17 mM. We now report on the effects of other commonly abused solvents (benzene, m-xylene, ethylbenzene, propylbenzene, 1,1,1-trichlorethane (TCE) and those of a convulsive solvent, 2,2,2-trifluoroethyl ether (flurothyl), on NMDA-induced currents measured in Xenopus oocytes expressing NR1/2A or NR1/2B receptor subtypes. All of the alkylbenzenes and TCE produced a reversible inhibition of NMDA-induced currents that was dose- and subunit-dependent. The NR1/2B receptor subtype was several times more sensitive to these compounds than the NR1/2A subtype. The convulsant solvent flurothyl had no effect on NMDA responses in oocytes but potently inhibited ion flux through recombinant GABA receptors expressed in oocytes. Overall, these results suggest that abused solvents display pharmacological selectivity and that NR1/2B NMDA receptors may be an important target for the actions of these compounds on the brain. PMID:11090101

Lubiprostone activates CFTR, but not ClC-2, via the prostaglandin receptor (EP(4)).

PubMed

Norimatsu, Yohei; Moran, Aurelia R; MacDonald, Kelvin D

2012-09-28

The goal of this study was to determine the mechanism of lubiprostone activation of epithelial chloride transport. Lubiprostone is a bicyclic fatty acid approved for the treatment of constipation [1]. There is uncertainty, however, as to how lubiprostone increases epithelial chloride transport. Direct stimulation of ClC-2 and CFTR chloride channels as well as stimulation of these channels via the EP(4) receptor has been described [2-5]. To better define this mechanism, two-electrode voltage clamp was used to assay Xenopus oocytes expressing ClC-2, with or without co-expression of the EP(4) receptor or β adrenergic receptor (βAR), for changes in conductance elicited by lubiprostone. Oocytes co-expressing CFTR and either βAR or the EP(4) receptor were also studied. In oocytes co-expressing ClC-2 and βAR conductance was stimulated by hyperpolarization and acidic pH (pH = 6), but there was no response to the β adrenergic agonist, isoproterenol. Oocytes expressing ClC-2 only or co-expressing ClC-2 and EP(4) did not respond to the presence of 0.1, 1, or 10 μM lubiprostone in the superperfusate. Oocytes co-expressing CFTR and βAR did not respond to hyperpolarization, acidic pH, or 1 μM lubiprostone. However, conductance was elevated by isoproterenol and inhibited by CFTR(inh)172. Co-expression of CFTR and EP(4) resulted in lubiprostone-stimulated conductance, which was also sensitive to CFTR(inh)172. The EC(50) for lubiprostone mediated CFTR activation was ~10 nM. These results demonstrate no direct action of lubiprostone on either ClC-2 or CFTR channels expressed in oocytes. However, the results confirm that CFTR can be activated by lubiprostone via the EP(4) receptor in oocytes. Copyright © 2012 Elsevier Inc. All rights reserved.

G protein-coupled receptor 30 down-regulates cofactor expression and interferes with the transcriptional activity of glucocorticoid.

PubMed

Ylikomi, Timo; Vienonen, Annika; Ahola, Tytti M

2004-11-01

G protein-coupled receptor 30 (GPR30) has previously been described to be important in steroid-mediated growth and to inhibit cell proliferation. Here we investigated whether the effect of GPR30 on cell growth is dependent on steroid hormone receptors. We stably introduced GPR30 in immortalized normal mammary epithelial (HME) cells using retroviruses for gene delivery. GPR30 inhibited the growth and proliferation of the cells. They expressed glucocorticoid receptor, but not estrogen or progesterone receptor. GPR30 down-regulated the expression of cofactor transcription intermediary factor 2 (TIF2) analyzed using quantitative RT-PCR analysis, and also diminished the expression of TIF2 at protein level analyzed by Western blotting using nuclear extracts from mammary epithelial cells. When HME cells were transiently transfected with the glucocorticoid response element MMTV-luc reporter plasmid, stable expression of GPR30 resulted in the abolition of ligand-induced transactivation of the promoter. In COS cells, transient transfection of GPR30 with glucocorticoid receptor alpha resulted in an abrogation of the MMTV-luc and GRE-luc reporter activities induced by dexamethasone. The results suggest a novel mechanism by which membrane-initiated signaling interferes with steroid signaling.

Functional identification and reconstitution of an odorant receptor in single olfactory neurons

PubMed Central

Touhara, Kazushige; Sengoku, Shintaro; Inaki, Koichiro; Tsuboi, Akio; Hirono, Junzo; Sato, Takaaki; Sakano, Hitoshi; Haga, Tatsuya

1999-01-01

The olfactory system is remarkable in its capacity to discriminate a wide range of odorants through a series of transduction events initiated in olfactory receptor neurons. Each olfactory neuron is expected to express only a single odorant receptor gene that belongs to the G protein coupled receptor family. The ligand–receptor interaction, however, has not been clearly characterized. This study demonstrates the functional identification of olfactory receptor(s) for specific odorant(s) from single olfactory neurons by a combination of Ca2+-imaging and reverse transcription–coupled PCR analysis. First, a candidate odorant receptor was cloned from a single tissue-printed olfactory neuron that displayed odorant-induced Ca2+ increase. Next, recombinant adenovirus-mediated expression of the isolated receptor gene was established in the olfactory epithelium by using green fluorescent protein as a marker. The infected neurons elicited external Ca2+ entry when exposed to the odorant that originally was used to identify the receptor gene. Experiments performed to determine ligand specificity revealed that the odorant receptor recognized specific structural motifs within odorant molecules. The odorant receptor-mediated signal transduction appears to be reconstituted by this two-step approach: the receptor screening for given odorant(s) from single neurons and the functional expression of the receptor via recombinant adenovirus. The present approach should enable us to examine not only ligand specificity of an odorant receptor but also receptor specificity and diversity for a particular odorant of interest. PMID:10097159

Amygdala Infusions of an NR2B-Selective or an NR2A-Preferring NMDA Receptor Antagonist Differentially Influence Fear Conditioning and Expression in the Fear-Potentiated Startle Test

ERIC Educational Resources Information Center

Walker, David L.; Davis, Michael

2008-01-01

Within the amygdala, most N-methyl-D-aspartic acid (NMDA) receptors consist of NR1 subunits in combination with either NR2A or NR2B subunits. Because the particular subunit composition greatly influences the receptors' properties, we investigated the contribution of both subtypes to fear conditioning and expression. To do so, we infused the…

Mutated CaV2.1 channels dysregulate CASK/P2X3 signaling in mouse trigeminal sensory neurons of R192Q Cacna1a knock-in mice.

PubMed

Gnanasekaran, Aswini; Bele, Tanja; Hullugundi, Swathi; Simonetti, Manuela; Ferrari, Michael D; van den Maagdenberg, Arn M J M; Nistri, Andrea; Fabbretti, Elsa

2013-12-02

ATP-gated P2X3 receptors of sensory ganglion neurons are important transducers of pain as they adapt their expression and function in response to acute and chronic nociceptive signals. The present study investigated the role of calcium/calmodulin-dependent serine protein kinase (CASK) in controlling P2X3 receptor expression and function in trigeminal ganglia from Cacna1a R192Q-mutated knock-in (KI) mice, a genetic model for familial hemiplegic migraine type-1. KI ganglion neurons showed more abundant CASK/P2X3 receptor complex at membrane level, a result that likely originated from gain-of-function effects of R192Q-mutated CaV2.1 channels and downstream enhanced CaMKII activity. The selective CaV2.1 channel blocker ω-Agatoxin IVA and the CaMKII inhibitor KN-93 were sufficient to return CASK/P2X3 co-expression to WT levels. After CASK silencing, P2X3 receptor expression was decreased in both WT and KI ganglia, supporting the role of CASK in P2X3 receptor stabilization. This process was functionally observed as reduced P2X3 receptor currents. We propose that, in trigeminal sensory neurons, the CASK/P2X3 complex has a dynamic nature depending on intracellular calcium and related signaling, that are enhanced in a transgenic mouse model of genetic hemiplegic migraine.

Permeability and single channel conductance of human homomeric ρ1 GABAC receptors

PubMed Central

Wotring, Virginia E; Chang, Yongchang; Weiss, David S

1999-01-01

Homomeric human ρ1 GABAC receptors were expressed in Xenopus oocytes and in human embryonic kidney cells (HEK293) in order to examine their conductance and permeability. Reversal potentials of currents elicited by γ-aminobutyric acid (GABA) were measured in extracellular solutions of various ionic composition to determine relative permeability of homomeric ρ1 receptors. The rank order of anionic permeability was: SCN− > I− > NO3− > Br− > Cl− > formate (For−) > HCO3− > acetate (Ac−) ≈ proprionate (Prop−) ≈ isethionate (Ise−) ≈ F−≈ PO4−. In the oocyte expression system, relative permeabilities to SCN−, I−, NO3−, Br− and HCO3− were higher for ρ1 GABAC receptors than α1β2γ2L GABAA receptors. Expression of ρ1 GABAC receptors in Xenopus oocytes and in HEK293 cells gave similar relative permeabilities for selected anions, suggesting that the expression system does not significantly alter permeation properties. The pore diameter of the homomeric ρ1 GABAC receptor expressed in oocytes was estimated to be 0.61 nm, which is somewhat larger than the 0.56 nm pore diameter estimated for α1β2γ2L GABAA receptors. Homomeric ρ1 GABA receptors expressed in oocytes had a single channel chord conductance of 0.65 ± 0.04 pS (mean ±s.e.m.s) when the internal chloride concentration ([Cl−]i) was 20 mm. With a [Cl−]i of 100 mm, the single channel chord conductance was 1.59 ± 0.24 pS. The mean open time directly measured from 43 GABA-induced channel openings in six patches was 3.2 ± 0.8 s. The mean open time in the presence of 100 μm picrotoxin was 0.07 ± 0.01 s (77 openings from 3 patches). The differences observed in ionic permeabilities, pore size, single channel conductance and mean open time suggest that the ρ1 homomeric receptor may not be the native retinal GABAC receptor reported previously. PMID:10581305

Activation and inhibition of mouse muscle and neuronal nicotinic acetylcholine receptors expressed in Xenopus oocytes.

PubMed

Papke, Roger L; Wecker, Lynn; Stitzel, Jerry A

2010-05-01

Transgenic mouse models with nicotinic acetylcholine receptor (nAChR) knockouts and knockins have provided important insights into the molecular substrates of addiction and disease. However, most studies of heterologously expressed neuronal nAChR have used clones obtained from other species, usually human or rat. In this work, we use mouse clones expressed in Xenopus oocytes to provide a relatively comprehensive characterization of the three primary classes of nAChR: muscle-type receptors, heteromeric neuronal receptors, and homomeric alpha7-type receptors. We evaluated the activation of these receptor subtypes with acetylcholine and cytisine-related compounds, including varenicline. We also characterized the activity of classic nAChR antagonists, confirming the utility of mecamylamine and dihydro-beta-erythroidine as selective antagonists in mouse models of alpha3beta4 and alpha4beta2 receptors, respectively. We also conducted an in-depth analysis of decamethonium and hexamethonium on muscle and neuronal receptor subtypes. Our data indicate that, as with receptors cloned from other species, pairwise expression of neuronal alpha and beta subunits in oocytes generates heterogeneous populations of receptors, most likely caused by variations in subunit stoichiometry. Coexpression of the mouse alpha5 subunit had varying effects, depending on the other subunits expressed. The properties of cytisine-related compounds are similar for mouse, rat, and human nAChR, except that varenicline produced greater residual inhibition of mouse alpha4beta2 receptors than with human receptors. We confirm that decamethonium is a partial agonist, selective for muscle-type receptors, but also note that it is a nondepolarizing antagonist for neuronal-type receptors. Hexamethonium was a relatively nonselective antagonist with mixed competitive and noncompetitive activity.

Activation and Inhibition of Mouse Muscle and Neuronal Nicotinic Acetylcholine Receptors Expressed in Xenopus Oocytes

PubMed Central

Wecker, Lynn; Stitzel, Jerry A.

2010-01-01

Transgenic mouse models with nicotinic acetylcholine receptor (nAChR) knockouts and knockins have provided important insights into the molecular substrates of addiction and disease. However, most studies of heterologously expressed neuronal nAChR have used clones obtained from other species, usually human or rat. In this work, we use mouse clones expressed in Xenopus oocytes to provide a relatively comprehensive characterization of the three primary classes of nAChR: muscle-type receptors, heteromeric neuronal receptors, and homomeric α7-type receptors. We evaluated the activation of these receptor subtypes with acetylcholine and cytisine-related compounds, including varenicline. We also characterized the activity of classic nAChR antagonists, confirming the utility of mecamylamine and dihydro-β-erythroidine as selective antagonists in mouse models of α3β4 and α4β2 receptors, respectively. We also conducted an in-depth analysis of decamethonium and hexamethonium on muscle and neuronal receptor subtypes. Our data indicate that, as with receptors cloned from other species, pairwise expression of neuronal α and β subunits in oocytes generates heterogeneous populations of receptors, most likely caused by variations in subunit stoichiometry. Coexpression of the mouse α5 subunit had varying effects, depending on the other subunits expressed. The properties of cytisine-related compounds are similar for mouse, rat, and human nAChR, except that varenicline produced greater residual inhibition of mouse α4β2 receptors than with human receptors. We confirm that decamethonium is a partial agonist, selective for muscle-type receptors, but also note that it is a nondepolarizing antagonist for neuronal-type receptors. Hexamethonium was a relatively nonselective antagonist with mixed competitive and noncompetitive activity. PMID:20100906

Bombesin-like peptide receptors in human bronchial epithelial cells.

PubMed

Kane, M A; Toi-Scott, M; Johnson, G L; Kelley, K K; Boose, D; Escobedo-Morse, A

1996-01-01

Northern blot and RNAse protection assays previously failed to detect bombesin-like peptide (BLP) receptors in normal human lung tissue, but by RT/PCR cultured human bronchial epithelial (HBE) cells expressed all three BLP receptor subtypes, predominantly neuromedin B (NMB) receptor. By RT/PCR, we found expression of all three BLP receptor subtypes by human lung tissue and confirmed NMB receptor expression in six out of six HBE samples. However, transformed HBE BEAS B2B cells expressed only gastrin-releasing peptide (GRP) receptors; saturable, high-affinity (Kd = 3.5 nM) specific [125I]GRP binding confirmed functional GRP receptor, with M(r) = 75 kDa and immunologic cross-reactivity with GRP receptor from human small-cell lung carcinoma (SCLC) NCI-H345 cells. Altered regulation of BLP receptors may accompany transformation of normal lung cells to cancer.

Attenuation of myocardial fibrosis with curcumin is mediated by modulating expression of angiotensin II AT1/AT2 receptors and ACE2 in rats

PubMed Central

Pang, Xue-Fen; Zhang, Li-Hui; Bai, Feng; Wang, Ning-Ping; Garner, Ron E; McKallip, Robert J; Zhao, Zhi-Qing

2015-01-01

Curcumin is known to improve cardiac function by balancing degradation and synthesis of collagens after myocardial infarction. This study tested the hypothesis that inhibition of myocardial fibrosis by curcumin is associated with modulating expression of angiotensin II (Ang II) receptors and angiotensin-converting enzyme 2 (ACE2). Male Sprague Dawley rats were subjected to Ang II infusion (500 ng/kg/min) using osmotic minipumps for 2 and 4 weeks, respectively, and curcumin (150 mg/kg/day) was fed by gastric gavage during Ang II infusion. Compared to the animals with Ang II infusion, curcumin significantly decreased the mean arterial blood pressure during the course of the observation. The protein level of the Ang II type 1 (AT1) receptor was reduced, and the Ang II type 2 (AT2) receptor was up-regulated, evidenced by an increased ratio of the AT2 receptor over the AT1 receptor in the curcumin group (1.2±0.02%) vs in the Ang II group (0.7±0.03%, P<0.05). These changes were coincident with less locally expressed AT1 receptor and enhanced AT2 receptor in the intracardiac vessels and intermyocardium. Along with these modulations, curcumin significantly decreased the populations of macrophages and alpha smooth muscle actin-expressing myofibroblasts, which were accompanied by reduced expression of transforming growth factor beta 1 and phosphorylated-Smad2/3. Collagen I synthesis was inhibited, and tissue fibrosis was attenuated, as demonstrated by less extensive collagen-rich fibrosis. Furthermore, curcumin increased protein level of ACE2 and enhanced its expression in the intermyocardium relative to the Ang II group. These results suggest that curcumin could be considered as an add-on therapeutic agent in the treatment of fibrosis-derived heart failure patient who is intolerant of ACE inhibitor therapy. PMID:26648693

Dopamine inhibits somatolactin gene expression in tilapia pituitary cells through the dopamine D2 receptors.

PubMed

Jiang, Quan; Lian, Anji; He, Qi

2016-07-01

Dopamine (DA) is an important neurotransmitter in the central nervous system of vertebrates and possesses key hypophysiotropic functions. Early studies have shown that DA has a potent inhibitory effect on somatolactin (SL) release in fish. However, the mechanisms responsible for DA inhibition of SL gene expression are largely unknown. To this end, tilapia DA type-1 (D1) and type-2 (D2) receptor transcripts were examined in the neurointermediate lobe (NIL) of the tilapia pituitary by real-time PCR. In tilapia, DA not only was effective in inhibiting SL mRNA levels in vivo and in vitro, but also could abolish pituitary adenylate cyclase-activating polypeptide (PACAP)- and salmon gonadotropin-releasing hormone (sGnRH)-stimulated SL gene expression at the pituitary level. In parallel studies, the specific D2 receptor agonists quinpirole and bromocriptine could mimic the DA-inhibited SL gene expression. Furthermore, the D2 receptor antagonists domperidone and (-)-sulpiride could abolish the SL response to DA or the D2 agonist quinpirole, whereas D1 receptor antagonists SCH23390 and SKF83566 were not effective in this respect. In primary cultures of tilapia NIL cells, D2 agonist quinpirole-inhibited cAMP production could be blocked by co-treatment with the D2 antagonist domperidone and the ability of forskolin to increase cAMP production was also inhibited by quinpirole. Using a pharmacological approach, the AC/cAMP pathway was shown to be involved in quinpirole-inhibited SL mRNA expression. These results provide evidence that DA can directly inhibit SL gene expression at the tilapia pituitary level via D2 receptor through the AC/cAMP-dependent mechanism. Copyright © 2016 Elsevier Inc. All rights reserved.

Potential Involvement of P2 Receptors in the Pathological Processes of Hyperthyroidism: A Pilot Study.

PubMed

Hong, Wu; Li, Guodong; Nie, Yijun; Zou, Lifang; Zhang, Xi; Liu, Shuangmei; Li, Guilin; Xu, Hong; Zhang, Chun-Ping; Liang, Shangdong

2016-05-01

Symptoms of hyperthyroidism manifest mainly as changes in the nervous and metabolic systems. Whether P2X receptors (ionotropic ATP purinergic receptors, including P2X3 receptor and P2X7 receptor) are involved in the alterations of these disorders still remains unclear. Thus, this study aimed to assess the association of hyperthyroidism with the expression of P2X3 and P2X7 receptors and the concentrations of ATP in blood leukocytes and catecholamine. Twelve healthy subjects and twelve patients diagnosed with hyperthyroidism were recruited. Serum free triiodothyronine (FT3), free thyroxine (FT4) and thyroid stimulating hormone (TSH) levels had been detected by chemiluminescence method. Meanwhile, the catecholamine levels (including adrenaline, noradrenaline, and dopamine) in plasma, ATP level and P2X receptors (including P2X3 receptor and P2X7 receptor) in peripheral blood had been detected by high performance liquid chromatography, bioluminescence method, and reverse transcription polymerase chain reaction, respectively. Levels of epinephrine and norepinephrine were significantly higher in the hyperthyroidism group compared with the control group. The concentration of ATP in the hyperthyroidism group was significantly higher than its in the control group. The expression of P2X3 mRNA and P2X7 mRNA in hyperthyroidism group were significantly increased compared with those in control group. In a conclusion, there is a relationship between the elevated expression of P2X3 receptor and P2X7 receptor in peripheral blood leukocytes and high serum epinephrine and norepinephrine levels in hyperthyroidism patients. © 2016 by the Association of Clinical Scientists, Inc.

A functional role for CD28 costimulation in tumor recognition by single-chain receptor-modified T cells.

PubMed

Moeller, Maria; Haynes, Nicole M; Trapani, Joseph A; Teng, Michele W L; Jackson, Jacob T; Tanner, Jane E; Cerutti, Loretta; Jane, Stephen M; Kershaw, Michael H; Smyth, Mark J; Darcy, Phillip K

2004-05-01

T cells engineered to express single-chain antibody receptors that incorporate TCR-zeta and cluster designation (CD)28 signaling domains (scFv-alpha-erbB2-CD28-zeta) can be redirected in vivo to cancer cells that lack triggering costimulatory molecules. To assess the contribution of CD28 signaling to the function of the scFv-CD28-zeta receptor, we expressed a series of mutated scFv-CD28-zeta receptors directed against erbB2. Residues known to be critical for CD28 signaling were mutated from tyrosine to phenylalanine at position 170 or proline to alanine at positions 187 and 190. Primary mouse T cells expressing either of the mutant receptors demonstrated impaired cytokine (IFN-gamma and GM-CSF) production and decreased proliferation after antigen ligation in vitro and decreased antitumor efficacy in vivo compared with T cells expressing the wild-type scFv-CD28-zeta receptor, suggesting a key signaling role for the CD28 component of the scFv-CD28-zeta receptor. Importantly, cell surface expression, binding capacity and cytolytic activity mediated by the scFv-CD28-zeta receptor were not diminished by either mutation. Overall, this study has definitively demonstrated a functional role for the CD28 component of the scFv-CD28-zeta receptor and has shown that incorporation of costimulatory activity in chimeric scFv receptors is a powerful approach for improving adoptive cancer immunotherapy.

Common α2A and α2C adrenergic receptor polymorphisms do not affect plasma membrane trafficking.

PubMed

Hurt, Carl M; Sorensen, Matt W; Angelotti, Timothy

2014-06-01

Various naturally occurring polymorphic forms of human G protein-coupled receptors (GPCRs) have been identified and linked to diverse pathological diseases, including receptors for vasopressin type 2 (nephrogenic diabetes insipidus) and gonadotropin releasing hormone (hypogonadotropic hypogonadism). In most cases, polymorphic amino acid mutations disrupt protein folding, altering receptor function as well as plasma membrane expression. Other pathological GPCR variants have been found that do not alter receptor function, but instead affect only plasma membrane trafficking (e.g., delta opiate and histamine type 1 receptors). Thus, altered membrane trafficking with retained receptor function may be another mechanism causing polymorphic GPCR dysfunction. Two common human α2A and α2C adrenergic receptor (AR) variants have been identified (α2A N251K and α2C Δ322-325 ARs), but pharmacological analysis of ligand binding and second messenger signaling has not consistently demonstrated altered receptor function. However, possible alterations in plasma membrane trafficking have not been investigated. We utilized a systematic approach previously developed for the study of GPCR trafficking motifs and accessory proteins to assess whether these α2 AR variants affected intracellular trafficking or plasma membrane expression. By combining immunofluorescent microscopy, glycosidic processing analysis, and quantitative fluorescent-activated cell sorting (FACS), we demonstrate that neither variant receptor had altered intracellular localization, glycosylation, nor plasma membrane expression compared to wild-type α2 ARs. Therefore, pathopharmacological properties of α2A N251K and α2C Δ322-325 ARs do not appear to be due to altered receptor pharmacology or plasma membrane trafficking, but may involve interactions with other intracellular signaling cascades or proteins.

Early expression of triggering receptors and regulatory role of 2B4 in human natural killer cell precursors undergoing in vitro differentiation

PubMed Central

Sivori, Simona; Falco, Michela; Marcenaro, Emanuela; Parolini, Silvia; Biassoni, Roberto; Bottino, Cristina; Moretta, Lorenzo; Moretta, Alessandro

2002-01-01

In this study we analyzed the progression of cell surface receptor expression during the in vitro-induced human natural killer (NK) cell maturation from CD34+ Lin− cell precursors. NKp46 and NKp30, two major triggering receptors that play a central role in natural cytotoxicity, were expressed before the HLA class I-specific inhibitory receptors. Moreover, their appearance at the cell surface correlated with the acquisition of cytolytic activity by developing NK cells. Although the early expression of triggering receptors may provide activating signals required for inducing further cell differentiation, it may also affect the self-tolerance of developing NK cells. Our data show that a fail-safe mechanism preventing killing of normal autologous cells may be provided by the 2B4 surface molecule, which, at early stages of NK cell differentiation, functions as an inhibitory rather than as an activating receptor. PMID:11917118

Expression of GnRH receptor in the canine corpus luteum, and luteal function following deslorelin acetate-induced puberty delay.

PubMed

Kaya, D; Gram, A; Kowalewski, M P; Schäfer-Somi, S; Kuru, M; Boos, A; Aslan, S

2017-12-01

The goals of this study were as follows: (Experiment 1) to examine the basic capability of canine corpora lutea (CL) to respond to GnRH by assessing expression of gonadotropin-releasing hormone receptor (GnRH-R) in luteal samples collected throughout the luteal lifespan from non-pregnant dogs, and (Experiment 2) to investigate the effects of pre-pubertal application of the GnRH agonist deslorelin acetate on luteal function following the first oestrus. Mature CL were collected during the mid-luteal phase (days 30-45) from treated and control bitches. Transcript levels of several factors were determined: estrogen receptors (ESR1/ERα, ESR2/ERβ), progesterone (P4)-receptor (PGR), prolactin receptor (PRLR), PGE2-synthase (PTGES) and PGE2 receptors (PTGER2/EP2, PTGER4/EP4), vascular endothelial growth factor (VEGFA) and VEGF receptors (VEGFR1 and VEGFR2), cyclooxygenase 2 (COX2/PTGS2), steroidogenic acute regulatory protein (STAR) and 3β-hydroxysteroid dehydrogenase (3βHSD). Additionally, levels of Kisspeptin 1 (Kiss1) and its receptor (KISS1-R) were evaluated. Although generally low, GnRH-R expression was time dependent and was elevated during early dioestrus, with a significant decrease towards luteal regression. In deslorelin-treated and control dogs, its expression was either low or frequently below the detection limit. EP2 and VEGFR1 were higher in the treated group, which could be caused by a feedback mechanism after long-term suppression of reproductive activity. Despite large individual variations, 3βHSD was higher in the deslorelin-treated group. This, along with unchanged STAR expression, was apparently not mirrored in increased luteal functionality, because similar P4 levels were detected in both groups. Finally, the deslorelin-mediated long-term delay of puberty does not have negative carry-over effects on subsequent ovarian functionality in bitches. © 2017 Blackwell Verlag GmbH.

Novel function of transcription factor Nrf2 as an inhibitor of RON tyrosine kinase receptor-mediated cancer cell invasion.

PubMed

Thangasamy, Amalraj; Rogge, Jessica; Krishnegowda, Naveen K; Freeman, James W; Ammanamanchi, Sudhakar

2011-09-16

Recepteur d' origine nantais (RON), a tyrosine kinase receptor, is aberrantly expressed in human tumors and promotes cancer cell invasion. RON receptor activation is also associated with resistance to tamoxifen treatment in breast cancer cells. Nrf2 is a positive regulator of cytoprotective genes. Using chromatin immunoprecipitation (ChIP) and site-directed mutagenesis studies of the RON promoter, we identified Nrf2 as a negative regulator of RON gene expression. High Nrf2 and low RON expression was observed in normal mammary tissue whereas high RON and low or undetectable expression of Nrf2 was observed in breast tumors. The Nrf2 inducer sulforaphane (SFN) as well as ectopic Nrf2 expression or knock-down of the Nrf2 negative regulator keap1, which stabilizes Nrf2, inhibited RON expression and invasion of carcinoma cells. Consequently, our studies identified a novel functional role for Nrf2 as a "repressor" and RON kinase as a molecular target of SFN, which mediates the anti-tumor effects of SFN. These results are not limited to breast cancer cells since the Nrf2 inducer SFN stabilized Nrf2 and inhibited RON expression in carcinoma cells from various tumor types.

AMPA, NMDA and kainate glutamate receptor subunits are expressed in human peripheral blood mononuclear cells (PBMCs) where the expression of GluK4 is altered by pregnancy and GluN2D by depression in pregnant women.

PubMed

Bhandage, Amol K; Jin, Zhe; Hellgren, Charlotte; Korol, Sergiy V; Nowak, Krzysztof; Williamsson, Louise; Sundström-Poromaa, Inger; Birnir, Bryndis

2017-04-15

The amino acid glutamate opens cation permeable ion channels, the iGlu receptors. These ion channels are abundantly expressed in the mammalian brain where glutamate is the main excitatory neurotransmitter. The neurotransmitters and their receptors are being increasingly detected in the cells of immune system. Here we examined the expression of the 18 known subunits of the iGlu receptors families; α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), kainate, N-methyl-d-aspartate (NMDA) and delta in human peripheral blood mononuclear cells (PBMCs). We compared the expression of the subunits between four groups: men, non-pregnant women, healthy pregnant women and depressed pregnant women. Out of 18 subunits of the iGlu receptors, mRNAs for 11 subunits were detected in PBMCs from men and non-pregnant women; AMPA: GluA3, GluA4, kainate: GluK2, GluK4, GluK5, NMDA: GluN1, GluN2C, GluN2D, GluN3A, GluN3B, and delta: GluD1. In the healthy and the depressed pregnant women, in addition, the delta GluD2 subunit was identified. The mRNAs for GluK4, GluK5, GluN2C and GluN2D were expressed at a higher level than other subunits. Gender, pregnancy or depression during pregnancy altered the expression of GluA3, GluK4, GluN2D, GluN3B and GluD1 iGlu subunit mRNAs. The greatest changes recorded were the lower GluA3 and GluK4 mRNA levels in pregnant women and the higher GluN2D mRNA level in healthy but not in depressed pregnant women as compared to non-pregnant individuals. Using subunit specific antibodies, the GluK4, GluK5, GluN1, GluN2C and GluN2D subunit proteins were identified in the PBMCs. The results show expression of specific iGlu receptor subunit in the PBMCs and support the idea of physiology-driven changes of iGlu receptors subtypes in the immune cells. Copyright © 2017 Elsevier B.V. All rights reserved.

Differential splicing and glycosylation of Apoer2 alters synaptic plasticity and fear learning.

PubMed

Wasser, Catherine R; Masiulis, Irene; Durakoglugil, Murat S; Lane-Donovan, Courtney; Xian, Xunde; Beffert, Uwe; Agarwala, Anandita; Hammer, Robert E; Herz, Joachim

2014-11-25

Apoer2 is an essential receptor in the central nervous system that binds to the apolipoprotein ApoE. Various splice variants of Apoer2 are produced. We showed that Apoer2 lacking exon 16, which encodes the O-linked sugar (OLS) domain, altered the proteolytic processing and abundance of Apoer2 in cells and synapse number and function in mice. In cultured cells expressing this splice variant, extracellular cleavage of OLS-deficient Apoer2 was reduced, consequently preventing γ-secretase-dependent release of the intracellular domain of Apoer2. Mice expressing Apoer2 lacking the OLS domain had increased Apoer2 abundance in the brain, hippocampal spine density, and glutamate receptor abundance, but decreased synaptic efficacy. Mice expressing a form of Apoer2 lacking the OLS domain and containing an alternatively spliced cytoplasmic tail region that promotes glutamate receptor signaling showed enhanced hippocampal long-term potentiation (LTP), a phenomenon associated with learning and memory. However, these mice did not display enhanced spatial learning in the Morris water maze, and cued fear conditioning was reduced. Reducing the expression of the mutant Apoer2 allele so that the abundance of the protein was similar to that of Apoer2 in wild-type mice normalized spine density, hippocampal LTP, and cued fear learning. These findings demonstrated a role for ApoE receptors as regulators of synaptic glutamate receptor activity and established differential receptor glycosylation as a potential regulator of synaptic function and memory. Copyright © 2014, American Association for the Advancement of Science.

Differential splicing and glycosylation of Apoer2 alters synaptic plasticity and fear learning

PubMed Central

Wasser, Catherine R.; Masiulis, Irene; Durakoglugil, Murat S.; Lane-Donovan, Courtney; Xian, Xunde; Beffert, Uwe; Agarwala, Anandita; Hammer, Robert E.; Herz, Joachim

2015-01-01

Apoer2 is an essential receptor in the central nervous system that binds to the apolipoprotein ApoE. Various splice variants of Apoer2 are produced. We showed that Apoer2 lacking exon 16, which encodes the O-linked sugar (OLS) domain, altered the proteolytic processing and abundance of Apoer2 in cells and synapse number and function in mice. In cultured cells expressing this splice variant, extracellular cleavage of OLS-deficient Apoer2 was reduced, consequently preventing γ-secretase-dependent release of the intracellular domain of Apoer2. Mice expressing Apoer2 lacking the OLS domain had increased Apoer2 abundance in the brain, hippocampal spine density, and glutamate receptor abundance, but decreased synaptic efficacy. Mice expressing a form of Apoer2 lacking the OLS domain and containing an alternatively spliced cytoplasmic tail region that promotes glutamate receptor signaling showed enhanced hippocampal long-term potentiation (LTP), a phenomenon associated with learning and memory. However, these mice did not display enhanced spatial learning in the Morris water maze, and cued fear conditioning was reduced. Reducing the expression of the mutant Apoer2 allele so that the abundance of the protein was similar to that of Apoer2 in wild-type mice normalized spine density, hippocampal LTP, and cued fear learning. These findings demonstrated a role for ApoE receptors as regulators of synaptic glutamate receptor activity and established differential receptor glycosylation as a potential regulator of synaptic function and memory. PMID:25429077

A unique gene expression signature associated with serotonin 2C receptor RNA editing in the prefrontal cortex and altered in suicide

PubMed Central

Di Narzo, Antonio Fabio; Kozlenkov, Alexey; Roussos, Panos; Hao, Ke; Hurd, Yasmin; Lewis, David A.; Sibille, Etienne; Siever, Larry J.; Koonin, Eugene; Dracheva, Stella

2014-01-01

Editing of the pre-mRNA for the serotonin receptor 2C (5-HT2CR) by site-specific adenosine deamination (A-to-I pre-mRNA editing) substantially increases the functional plasticity of this key neurotransmitter receptor and is thought to contribute to homeostatic mechanisms in neurons. 5-HT2CR mRNA editing generates up to 24 different receptor isoforms. The extent of editing correlates with 5-HT2CR functional activity: more highly edited isoforms exhibit the least function. Altered 5-HT2CR editing has been reported in postmortem brains of suicide victims. We report a comparative analysis of the connections among 5-HT2CR editing, genome-wide gene expression and DNA methylation in suicide victims, individuals with major depressive disorder and non-psychiatric controls. The results confirm previous findings of an overrepresentation of highly edited mRNA variants (which encode hypoactive 5-HT2CR receptors) in the brains of suicide victims. A large set of genes for which the expression level is associated with editing was detected. This signature set of editing-associated genes is significantly enriched for genes that are involved in synaptic transmission, genes that are preferentially expressed in neurons, and genes whose expression is correlated with the level of DNA methylation. Notably, we report that the link between 5-HT2CR editing and gene expression is disrupted in suicide victims. The results suggest that the postulated homeostatic function of 5-HT2CR editing is dysregulated in individuals who committed suicide. PMID:24781207

Different expressions and DNA methylation patterns of lysophosphatidic acid receptor genes in mouse tumor cells.

PubMed

Okabe, Kyoko; Hayashi, Mai; Wakabayashi, Naoko; Yamawaki, Yasuna; Teranishi, Miki; Fukushima, Nobuyuki; Tsujiuchi, Toshifumi

2010-01-01

Lysophosphatidic acid (LPA) receptors act as several biological effectors through LPA, which is a bioactive phospholipid. Recently, aberrant expressions of LPA receptor genes due to DNA methylation have been detected in several tumor cells. In this study, we measured expression levels and DNA methylation status of LPA receptor genes in mouse tumor cells, LL/2 lung carcinoma, B16F0 melanoma, FM3A mammary carcinoma and L1210 leukemia cells, compared with normal tissues. Total RNAs were extracted and RT-PCR analysis was performed. For DNA methylation status, bisulfite sequencing analysis was carried out, comparing outcomes with other tumor cells and normal tissues. The expressions of LPA1 gene were shown in LL/2, but not in B16F0, FM3A and L1210 cells. While the LPA2 gene was expressed in all 4 tumor cells, the LPA3 gene was unexpressed in them. The LPA1 and LPA3 unexpressed cells were highly methylated, although normal tissues were all unmethylated. The DNA methylation status was correlated with gene expression levels in cancer cells. The present results demonstrate that DNA methylation patterns of LPA receptor genes are dependent on cancer cell types, suggesting that LPA receptors may be new molecular targets for therapeutic approaches and chemoprevention. Copyright © 2011 S. Karger AG, Basel.

Nuclear receptors HR96 and ultraspiracle from the fall armyworm (Spodoptera frugiperda), developmental expression and induction by xenobiotics.

PubMed

Giraudo, Maeva; Audant, Pascaline; Feyereisen, René; Le Goff, Gaëlle

2013-05-01

The fall armyworm Spodoptera frugiperda is a major polyphagous pest in agriculture and little is known on how this insect can adapt to the diverse and potentially toxic plant allelochemicals that they ingest or to insecticides. To investigate the involvement of nuclear receptors in the response of S. frugiperda to its chemical environment, we cloned SfHR96, a nuclear receptor orthologous to the mammalian xenobiotic receptors, pregnane X receptor (PXR) and constitutive androstane receptor (CAR). We also cloned ultraspiracle (USP), the ortholog of retinoid X receptor (RXR) that serves as partner of dimerization of PXR and CAR. Cloning of SfUSP revealed the presence of two isoforms, SfUSP-1 and SfUSP-2 in this species, that differ in their N-terminal region. The expression of these receptors as well as the ecdysone receptor was studied during specific steps of development in different tissues. SfHR96 was constitutively expressed in larval midgut, fat body and Malpighian tubules throughout the last two instars and pupal stage, as well as in Sf9 cells. EcR and SfUSP-2 showed peaks of expression before larval moults and during metamorphosis, whereas SfUSP-1 was mainly expressed in the pre-pupal stage. Receptor induction was followed after exposure of larvae or cells to 11 chemical compounds. SfHR96 was not inducible by the tested compounds. EcR was significantly induced by the 20-hydroxyecdysone agonist, methoxyfenozide, and SfUSP showed an increase expression when exposed to the juvenile hormone analog, methoprene. The cloning of these nuclear receptors is a first step in understanding the important capacities of adaptation of this insect pest. Copyright © 2013 Elsevier Ltd. All rights reserved.

TRAIL Death Receptor-4, Decoy Receptor-1 and Decoy Receptor-2 Expression on CD8+ T Cells Correlate with the Disease Severity in Patients with Rheumatoid Arthritis

PubMed Central

2010-01-01

Background Rheumatoid Arthritis (RA) is a chronic autoimmune inflammatory disorder. Although the pathogenesis of disease is unclear, it is well known that T cells play a major role in both development and perpetuation of RA through activating macrophages and B cells. Since the lack of TNF-Related Apoptosis Inducing Ligand (TRAIL) expression resulted in defective thymocyte apoptosis leading to an autoimmune disease, we explored evidence for alterations in TRAIL/TRAIL receptor expression on peripheral T lymphocytes in the molecular mechanism of RA development. Methods The expression of TRAIL/TRAIL receptors on T cells in 20 RA patients and 12 control individuals were analyzed using flow cytometry. The correlation of TRAIL and its receptor expression profile was compared with clinical RA parameters (RA activity scored as per DAS28) using Spearman Rho Analysis. Results While no change was detected in the ratio of CD4+ to CD8+ T cells between controls and RA patient groups, upregulation of TRAIL and its receptors (both death and decoy) was detected on both CD4+ and CD8+ T cells in RA patients compared to control individuals. Death Receptor-4 (DR4) and the decoy receptors DcR1 and DcR2 on CD8+ T cells, but not on CD4+ T cells, were positively correlated with patients' DAS scores. Conclusions Our data suggest that TRAIL/TRAIL receptor expression profiles on T cells might be important in revelation of RA pathogenesis. PMID:20799941

Low-Dose Cannabinoid Type 2 Receptor Agonist Attenuates Tolerance to Repeated Morphine Administration via Regulating μ-Opioid Receptor Expression in Walker 256 Tumor-Bearing Rats.

PubMed

Zhang, Mingyue; Wang, Kun; Ma, Min; Tian, Songyu; Wei, Na; Wang, Guonian

2016-04-01

Morphine is widely used in patients with moderate and severe cancer pain, whereas the development of drug tolerance remains a major problem associated with opioid use. Previous studies have shown that cannabinoid type 2 (CB2) receptor agonists induce morphine analgesia, attenuate morphine tolerance in normal and neuropathic pain animals, induce transcription of the μ-opioid receptor (MOR) gene in Jurkat T cells, and increase morphine analgesia in cancer pain animals. However, no studies of the effects of CB2 receptor agonists on morphine tolerance in cancer pain have been performed. Therefore, we investigated the effect of repeated intrathecal (IT) injection of the low-dose CB2 receptor agonist AM1241 on the development of morphine tolerance in walker 256 tumor-bearing rats. We also tested the influence of the CB2 receptor agonist AM1241 on MOR protein and messenger ribonucleic acid (mRNA) expression in the rat spinal cord and dorsal root ganglia (DRG). Walker 256 cells were implanted into the plantar region of each rat's right hindpaw. Tumor-bearing rats received IT injection of the CB2 receptor agonist AM1241 or antagonist AM630 with or without morphine subcutaneously twice daily for 8 days. Rats receiving drug vehicle only served as the control group. Mechanical paw withdrawal threshold and thermal paw withdrawal latency were assessed by a von Frey test and hot plate test 30 minutes after drug administration every day. MOR protein and mRNA expression in the spinal cord and DRG were detected after the last day (day 8) of drug administration via Western blot and real-time reverse transcription polymerase chain reaction. The data were analyzed via analysis of variance followed by Student t test with Bonferroni correction for multiple comparisons. Repeated morphine treatments reduced the mechanical withdrawal threshold and thermal latency. Coadministration of a nonanalgetic dose of the CB2 receptor agonist AM1241 with morphine significantly inhibited the development of morphine tolerance and increased the MOR protein expression in the spinal cord and DRG and mRNA expression in the spinal cord in tumor-bearing rats. Our findings indicate that IT injection of a nonanalgetic dose of a CB2 receptor agonist increased the analgesia effect and alleviated tolerance to morphine in tumor-bearing rats, potentially by regulating MOR expression in the spinal cord and DRG. This receptor may be a new target for prevention of the development of opioid tolerance in cancer pain.

Efficient production of membrane-integrated and detergent-soluble G protein-coupled receptors in Escherichia coli.

PubMed

Link, A James; Skretas, Georgios; Strauch, Eva-Maria; Chari, Nandini S; Georgiou, George

2008-10-01

G protein-coupled receptors (GPCRs) are notoriously difficult to express, particularly in microbial systems. Using GPCR fusions with the green fluorescent protein (GFP), we conducted studies to identify bacterial host effector genes that result in a general and significant enhancement in the amount of membrane-integrated human GPCRs that can be produced in Escherichia coli. We show that coexpression of the membrane-bound AAA+ protease FtsH greatly enhances the expression yield of four different class I GPCRs, irrespective of the presence of GFP. Using this new expression system, we produced 0.5 and 2 mg/L of detergent-solubilized and purified full-length central cannabinoid receptor (CB1) and bradykinin receptor 2 (BR2) in shake flask cultures, respectively, two proteins that had previously eluded expression in microbial systems.

Channel catfish (Ictalurus punctatus) leukocytes express estrogen receptor isoforms ERα and ERβ2 and are functionally modulated by estrogens

USGS Publications Warehouse

Iwanowicz, Luke R.; Stafford, James L.; Patiño, Reynaldo; Bengten, Eva; Miller, Norman W.; Blazer, Vicki

2014-01-01

Estrogens are recognized as modulators of immune responses in mammals and teleosts. While it is known that the effects of estrogens are mediated via leukocyte-specific estrogen receptors (ERs) in humans and mice, leucocyte-specific estrogen receptor expression and the effects of estrogens on this cell population is less explored and poorly understood in teleosts. Here in, we verify that channel catfish (Ictalurus punctaus) leukocytes express ERα and ERβ2. Transcripts of these isoforms were detected in tissue-associated leukocyte populations by PCR, but ERβ2 was rarely detected in PBLs. Expression of these receptors was temporally regulated in PBLs following polyclonal activation by concanavalin A, lipopolysaccharide or alloantigen based on evaluation by quantitative and end-point PCR. Examination of long-term leukocyte cell lines demonstrated that these receptors are differentially expressed depending on leukocyte lineage and phenotype. Expression of ERs was also temporally dynamic in some leukocyte lineages and may reflect stage of cell maturity. Estrogens affect the responsiveness of channel catfish peripheral blood leukocytes (PBLs) to mitogens in vitro. Similarly, bactericidal activity and phorbol 12-myristate 13-acetate induced respiratory burst was modulated by 17β-estradiol. These actions were blocked by the pure ER antagonist ICI 182780 indicating that response is, in part, mediated via ERα. In summary, estrogen receptors are expressed in channel catfish leukocytes and participate in the regulation of the immune response. This is the first time leukocyte lineage expression has been reported in teleost cell lines.

PKC/CREB pathway mediates the expressions of GABAA receptor subunits in cultured hippocampal neurons after low-Mg2+ solution treatment.

PubMed

Wu, Guofeng; Yu, Jinpeng; Wang, Likun; Ren, Siying; Zhang, Yixia

2018-02-01

To investigate the potential effects of the PKC/CREB pathway on the expressions of GABA A receptor subunits α1, γ2, and δ in cultured hippocampal neurons using a model of epilepsy that employed conditions of low magnesium (Mg 2+ ). A total of 108 embryonic rats at the age of 18 embryonic days (E18)prepared from adult female SD rats were used as experimental subjects. Primary rat hippocampal cultures were prepared from the embryonic 18 days rats. The cultured hippocampal neurons were then treated with artificial cerebrospinal fluid containing low Mg 2+ solutions to generate a low Mg 2+ model of epilepsy. The low Mg 2+ stimulation lasted for 3 h and then returned to in maintenance medium for 20 h. The changes of the GABA A receptor subunit α1, γ2, δ were observed by blocking or activating the function of the CREB. The quantification of the GABA A receptor subunit α1, γ2, δ and the CREB were determined by a qRT-PCR and a Western blot method. After the neurons were exposed to a low-Mg 2+ solution for 3 h, GABA A receptor mRNA expression markedly increased compared to the control, and then gradually decreased. In contrast, CREB mRNA levels exhibited a dramatic down-regulation 3 h after terminating low-Mg 2+ treatment, and then peaked at 9 h. Western blot analyses verified that staurosporine suppressed CREB phosphorylation (p-CREB). The mRNA expression of GABA A receptor subunit α1 increased only in the presence of staurosporine, whereas the expressions of subunits γ2 and δ significantly increased in the presence of either KG-501 or staurosporine. Furthermore, phorbol 12-myristate 13-acetate (PMA) decreased the expressions of GABA A subunits α1, γ2, and δ when administered alone. However, the administration of either KG-501 or staurosporine reversed the inhibitory effects of PMA. The PKC/CREB pathway may negatively regulate the expressions of GABA A receptor subunits α1, γ2, and δ in cultured hippocampal neurons in low Mg 2+ model of epilepsy. Copyright © 2017. Published by Elsevier B.V.

FH Afrikaner-3 LDL receptor mutation results in defective LDL receptors and causes a mild form of familial hypercholesterolemia.

PubMed

Graadt van Roggen, J F; van der Westhuyzen, D R; Coetzee, G A; Marais, A D; Steyn, K; Langenhoven, E; Kotze, M J

1995-06-01

Three founder-related gene mutations (FH Afrikaner-1, -2, and -3) that affect the LDL receptor are responsible for 90% of the familial hypercholesterolemia (FH) in South African Afrikaners. Patients heterozygous for the FH Afrikaner-1 (FH1) mutation, which results in receptors having approximately 20% of normal receptor activity, have significantly lower plasma cholesterol levels and milder clinical symptoms than heterozygotes with the FH Afrikaner-2 mutation, which completely abolishes LDL receptor activity. In this study we re-created the FH3 mutation (Asp154-->Asn) in exon 4 by site-directed mutagenesis and analyzed the expression of the mutant receptors in Chinese hamster ovary cells. The mutation resulted in the formation of LDL receptors that are markedly defective in their ability to bind LDL, whereas binding of apoE-containing beta-VLDL is less affected. The mutant receptors are poorly expressed on the cell surface as a result of significant degradation of receptor precursors. The plasma cholesterol levels of 31 FH3 heterozygotes were similar to FH1 heterozygotes but significantly lower than FH2 heterozygotes. The FH1 and FH3 heterozygotes also tended to be less severely affected clinically (by coronary heart disease and xanthomata) than FH2 patients. This study demonstrates that mutational heterogeneity in the LDL receptor gene influences the phenotypic expression of heterozygous FH and that severity of expression correlates with the activity of the LDL receptor measured in vitro. The results further indicate that knowledge of the specific mutation underlying FH in heterozygotes is valuable in determining the potential risk of premature atherosclerosis and should influence the clinical management of FH patients.

Constitutive Activity among Orphan Class-A G Protein Coupled Receptors.

PubMed

Martin, Adam L; Steurer, Michael A; Aronstam, Robert S

2015-01-01

The purpose of this study was to evaluate the extent of constitutive activity among orphan class-A G protein coupled receptors within the cAMP signaling pathway. Constitutive signaling was revealed by changes in gene expression under control of the cAMP response element. Gene expression was measured in Chinese hamster ovary cells transiently co-transfected with plasmids containing a luciferase reporter and orphan receptor. Criteria adopted for defining constitutive activation were: 1) 200% elevation over baseline reporter gene expression; 2) 40% inhibition of baseline expression; and 3) 40% inhibition of expression stimulated by 3 μM forskolin. Five patterns of activity were noted: 1) inhibition under both baseline and forskolin stimulated expression (GPR15, GPR17, GPR18, GPR20, GPR25, GPR27, GPR31, GPR32, GPR45, GPR57, GPR68, GPR83, GPR84, GPR132, GPR150, GPR176); 2) no effect on baseline expression, but inhibition of forskolin stimulated expression (GPR4, GPR26, GPR61, GPR62, GPR78, GPR101, GPR119); 3) elevation of baseline signaling coupled with inhibition of forskolin stimulated expression (GPR6, GPR12); 4) elevation of baseline signaling without inhibition of forskolin stimulated expression (GPR3, GPR21, GPR52, GPR65); and 5) no effect on expression (GPR1, GPR19, GPR22, GPR34, GPR35, GPR39, GPR63, GPR82, GPR85, GPR87). Constitutive activity was observed in 75% of the orphan class-A receptors examined (30 of 40). This constitutive signaling cannot be explained by simple overexpression of the receptor. Inhibition of cAMP mediated expression was far more common (65%) than stimulation of expression (15%). Orphan receptors that were closely related based on amino acid homology tended to have similar effects on gene expression. These results suggest that identification of inverse agonists may be a fruitful approach for categorizing these orphan receptors and targeting them for pharmacological intervention.

Constitutive Activity among Orphan Class-A G Protein Coupled Receptors

PubMed Central

Martin, Adam L.; Steurer, Michael A.; Aronstam, Robert S.

2015-01-01

The purpose of this study was to evaluate the extent of constitutive activity among orphan class-A G protein coupled receptors within the cAMP signaling pathway. Constitutive signaling was revealed by changes in gene expression under control of the cAMP response element. Gene expression was measured in Chinese hamster ovary cells transiently co-transfected with plasmids containing a luciferase reporter and orphan receptor. Criteria adopted for defining constitutive activation were: 1) 200% elevation over baseline reporter gene expression; 2) 40% inhibition of baseline expression; and 3) 40% inhibition of expression stimulated by 3 μM forskolin. Five patterns of activity were noted: 1) inhibition under both baseline and forskolin stimulated expression (GPR15, GPR17, GPR18, GPR20, GPR25, GPR27, GPR31, GPR32, GPR45, GPR57, GPR68, GPR83, GPR84, GPR132, GPR150, GPR176); 2) no effect on baseline expression, but inhibition of forskolin stimulated expression (GPR4, GPR26, GPR61, GPR62, GPR78, GPR101, GPR119); 3) elevation of baseline signaling coupled with inhibition of forskolin stimulated expression (GPR6, GPR12); 4) elevation of baseline signaling without inhibition of forskolin stimulated expression (GPR3, GPR21, GPR52, GPR65); and 5) no effect on expression (GPR1, GPR19, GPR22, GPR34, GPR35, GPR39, GPR63, GPR82, GPR85, GPR87). Constitutive activity was observed in 75% of the orphan class-A receptors examined (30 of 40). This constitutive signaling cannot be explained by simple overexpression of the receptor. Inhibition of cAMP mediated expression was far more common (65%) than stimulation of expression (15%). Orphan receptors that were closely related based on amino acid homology tended to have similar effects on gene expression. These results suggest that identification of inverse agonists may be a fruitful approach for categorizing these orphan receptors and targeting them for pharmacological intervention. PMID:26384023

P2X and P2Y receptors as possible targets of therapeutic manipulations in CNS illnesses.

PubMed

Köles, Laszlo; Furst, Susanna; Illes, Peter

2005-03-01

Adenine and/or uridine nucleotide-sensitive receptors are classified into two types belonging to the ligand-gated ionotropic family (P2X) and the metabotropic, G-protein-coupled family (P2Y). In humans, seven different P2X receptors (P2X(1-7)) and eight different P2Y receptors (P2Y(1), P2Y(2), P2Y(4), P2Y(6), P2Y(11-14)) have been detected hitherto. All P2 receptors are expressed in the CNS, with the preferential expression of the P2X(2), P2X(4), P2X(6) and P2Y(1) receptors in neurons. In addition to the neurotransmitter and modulator functions, neurite outgrowth, proliferation of glial cells and the expression of transmitter receptors at target cells have also been suggested to be regulated by extracellular nucleotides in the nervous system. In spite of the expanding knowledge in the purinergic research field, the present therapeutic utilization of P2 receptor ligands is mostly related to peripheral diseases such as thromboembolic disorders and cystic fibrosis. In this review we provide some evidence that P2 receptors play an important role in the regulation of CNS functions related to hippocampal activity, the mesolimbic dopaminergic system and the nociceptive system. The role of purinergic receptors located on astrocytes/microglia and implications of these receptors for neurodegenerative/neuroinflammatory disorders, CNS injury and epilepsy will be highlighted as well. (c) 2005 Prous Science. All rights reserved.

Conventional light chains inhibit the autonomous signaling capacity of the B cell receptor.

PubMed

Meixlsperger, Sonja; Köhler, Fabian; Wossning, Thomas; Reppel, Michael; Müschen, Markus; Jumaa, Hassan

2007-03-01

Signals from the B cell antigen receptor (BCR), consisting of mu heavy chain (muHC) and conventional light chain (LC), and its precursor the pre-BCR, consisting of muHC and surrogate light chain (SLC), via the adaptor protein SLP-65 regulate the development and function of B cells. Here, we compare the effect of SLC and conventional LC expression on receptor-induced Ca(2+) flux in B cells expressing an inducible form of SLP-65. We found that SLC expression strongly enhanced an autonomous ability of muHC to induce Ca(2+) flux irrespective of additional receptor crosslinking. In contrast, LC expression reduced this autonomous muHC ability and resulted in antigen-dependent Ca(2+) flux. These data indicate that autonomous ligand-independent signaling can be induced by receptor forms other than the pre-BCR. In addition, our data suggest that conventional LCs play an important role in the inhibition of autonomous receptor signaling, thereby allowing further B cell differentiation.

Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) and its receptor PROKR2 are associated to human colorectal cancer progression and peritoneal carcinomatosis.

PubMed

Benlahfid, Mohammed; Traboulsi, Wael; Sergent, Frederic; Benharouga, Mohamed; Elhattabi, Khalid; Erguibi, Driss; Karkouri, Mehdi; Elattar, Hicham; Fadil, Abdelaziz; Fahmi, Yassine; Aboussaouira, Touria; Alfaidy, Nadia

2018-02-06

The highest risk factor for mortality among malignant tumors is metastasis. Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) is an angiogenic factor which biological activity is mediated via two G protein-coupled receptors, prokineticin receptor1 (PROKR1) and PROKR2. Recent studies suggested that EG-VEGF expression is deregulated in multiple cancers including colorectal cancer (CRC). Using distinctive CRC and peritoneal carcinomatosis (PC) cohorts and a corresponding control cohort, we determined the circulating levels of EG-VEGF and its in situ expression, and that of its related receptors. Circulating EG-VEGF levels were significantly increased in patients with metastatic PC compared to CRC and control patients (p< 0.05). Furthermore, according to clinicopathologic examinations, local EG-VEGF expression correlated with higher tumor and nodal stages (p< 0.001) of CRC. EG-VEGF and PROKR2 were highly expressed in colorectal primary lesions compared to positive controls. PROKR1 expression was lower and did not change in tumor specimens. Also, EG-VEGF and its receptor PROKR2 were differentially expressed in the colorectal primary lesions and in the control groups. Altogether these findings suggest that EG-VEGF/receptors system might be an important actor in the CRC progression into PC and might be involved in the ability of tumor cells to invade other organs. Circulating EG-VEGF could be proposed as a prognostic marker in human CRC and its progression into PC.

Immunohistochemical localization of bone morphogenetic proteins and the receptors in epiphyseal growth plate.

PubMed

Yazaki, Y; Matsunaga, S; Onishi, T; Nagamine, T; Origuchi, N; Yamamoto, T; Ishidou, Y; Imamura, T; Sakou, T

1998-01-01

The expression of bone morphogenetic proteins (BMPs) and BMP receptors (BMPRs) in the epiphyseal growth plate has not been clarified. In this study, we studied immunohistochemically the spatial and temporal localization of BMP-2/4, osteogenic protein-1 (OP-1, or BMP-7), and BMP receptors (BMPR-IA, BMPR-IB, and BMPR-II) in the epiphyseal plate of growing rats. The proximal parts of tibia in growing rats were observed. At 12 weeks after birth, BMP-2/4 and OP-1 were expressed markedly in proliferating and maturing chondrocytes. BMPR-IA, IB and II were clearly co-expressed in proliferating and maturing chondrocytes, and the expression was decreased in hypertrophic chondrocytes. At 24 weeks, the expression of BMP-2/4 and OP-1 was decreased, but BMPRs were still well-expressed in proliferating chondrocytes. The temporal and spatial expression of BMP and BMPR suggests that BMP and BMP receptors play roles in the multistep cascade of enchondral ossification in the epiphyseal growth plate.

A shifted repertoire of endocannabinoid genes in the zebrafish (Danio rerio).

PubMed

McPartland, J M; Glass, Michelle; Matias, Isabel; Norris, Ryan W; Kilpatrick, C William

2007-05-01

The zebrafish has served as a model organism for developmental biology. Sequencing its genome has expanded zebrafish research into physiology and drug-development testing. Several cannabinoid pharmaceuticals are in development, but expression of endocannabinoid receptors and enzymes remains unknown in this species. We conducted a bioinformatics analysis of the zebrafish genome using 17 human endocannabinoid genes as a reference set. Putative zebrafish orthologs were identified in filtered BLAST searches as reciprocal best hits. Orthology was confirmed by three in silico methods: phylogenetic testing, synteny analysis, and functional mapping. Zebrafish expressed orthologs of cannabinoid receptor 1, transient receptor potential channel vanilloid receptor 4, GPR55 receptor, fatty acid amide hydrolase 1, monoacylglycerol lipase, NAPE-selective phospholipase D, abhydrolase domain-containing protein 4, and diacylglycerol lipase alpha and beta; and paired paralogs of cannabinoid receptor 2, fatty acid amide hydrolase 2, peroxisome proliferator-activated receptor alpha, prostaglandin-endoperoxide synthase 2, and transient receptor potential cation channel subtype A1. Functional mapping suggested the orthologs of transient receptor potential vanilloid receptor 1 and peroxisome proliferator-activated receptor gamma lack specific amino acids critical for cannabinoid ligand binding. No orthologs of N-acylethanolamine acid amidase or protein tyrosine phosphatase, non-receptor type 22 were identified. In conclusion, the zebrafish genome expresses a shifted repertoire of endocannabinoid genes. In vitro analyses are warranted before using zebrafish for cannabinoid development testing.

Targeted gene expression profiling in European sea bass (Dicentrarchus labrax, L.) follicles from primary growth to late vitellogenesis.

PubMed

García-López, Angel; Sánchez-Amaya, María Isabel; Prat, Francisco

2011-11-01

A real-time PCR-based gene expression survey was performed on isolated European sea bass follicles from primary growth to late vitellogenesis. Expression levels of 18 transcripts with demonstrated relevance during oogenesis, encoding gonadotropin, thyrotropin, estrogen, androgen, and vitellogenin receptors, steroidogenesis-related as well as growth and transcription factors were measured. Primary oocytes showed high mRNA levels of insulin-like growth factors 1 and 2, bone morphogenetic protein 4, estrogen receptor 2b, androgen receptor b, and SRY-box containing gene 17 together with low transcript amounts of gonadotropin receptors. Follicles at the lipid vesicles stage (i.e., the beginning of the secondary growth phase) showed elevated mRNA amounts of follicle stimulating hormone receptor (fshr) and anti-Mullerian hormone. Early-to-mid vitellogenic follicles showed high mRNA levels of fshr and cytochrome P450, family 19, subfamily A, polypeptide 1a while mid-to-late vitellogenic follicles expressed increasing transcript amounts of luteinizing hormone/choriogonadotropin receptor, steroidogenic acute regulatory protein, and estrogen receptors 1 and 2a. The molecular data presented here may serve as a solid base for future studies focused on unraveling the specific mechanisms orchestrating follicular development in teleost fish. Copyright © 2011 Elsevier Inc. All rights reserved.

Cerebral ischemia induced inflammatory response and altered glutaminergic function mediated through brain AT1 and not AT2 receptor.

PubMed

Justin, A; Divakar, S; Ramanathan, M

2018-06-01

In the present study, we investigated the effects of angiotensin (Ang II) receptor blockers in cerebral ischemia by administration of telmisartan (AT 1 blocker) and/or PD123319 (AT 2 blocker) in global ischemic mice model. The neuroprotective effect of AT antagonists was evaluated through monitoring muscle co-ordination and cerebral blood perfusion in ischemic mice. Gene expression studies (NF-κB, GSK-3β, EAAT-2, AT 1 & AT 2 receptors) and staining of brain regions with cresyl violet, GFAP, synaptophysin and NSE methods were carried out in to understand the molecular mechanisms. Further, the brain glutamate, cytokines, and Ang II peptide levels were evaluated and their correlation with EAAT-2 mRNA expression was performed. Our results indicate that the induction of ischemia elevates brain Ang II, cytokines, and glutamate levels and reduced muscle co-ordination and cerebral blood perfusion. The expressions of NF-κB, GSK-3β and AT 1 were significantly increased, whereas, EAAT-2 expression was decreased. Blocking of AT 1 receptors by telmisartan (TM) reversed the detrimental responses of cerebral ischemia and restored the cerebral blood flow denoting blockade of Ang II/AT 1 pathway is beneficial in ischemia, whereas, blockade of AT 2 receptors by PD123319 (PD) increased the ischemic injury in mice. This vulnerable effect of PD may be attributed through augmenting the Ang II/AT 1 dependent cytokines mediated glutamate transporter (EAAT-2) dysfunction. Interestingly, the beneficial effects of AT 1 blocker was remarkably antagonized by AT 2 blocker in most of the parameters studied in ischemic conditions. Also, the expression of AT 2 receptors was significantly increased compared to that of AT 1 receptors upon ischemic induction. It denotes that the endogenous Ang II predominantly acts on AT 2 receptor, thereby promoting its own mRNA transcription. Hence, the increased expression of AT 2 receptors in ischemic condition could be used as target protein for therapeutic benefit. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Methionine Deprivation Induces a Targetable Vulnerability in Triple-negative Breast Cancer Cells by Enhancing TRAIL Receptor-2 Expression

PubMed Central

Strekalova, Elena; Malin, Dmitry; Good, David M.; Cryns, Vincent L.

2015-01-01

Purpose Many neoplasms are vulnerable to methionine deficiency by mechanisms that are poorly understood. Because gene profiling studies have revealed that methionine depletion increases TNF-related apoptosis-inducing ligand receptor-2 (TRAIL-R2) mRNA, we postulated that methionine stress sensitizes breast cancer cells to proapoptotic TRAIL-R2 agonists. Experimental Design Human triple (ER/PR/HER2)-negative breast carcinoma cell lines were cultured in control or methionine-free media. The effects of methionine depletion on TRAIL receptor expression and sensitivity to chemotherapy or a humanized agonistic TRAIL-R2 monoclonal antibody (lexatumumab) were determined. The melanoma-associated antigen MAGED2 was silenced to delineate its functional role in sensitizing TNBC cells to methionine stress. An orthotopic TNBC model was utilized to evaluate the effects of dietary methionine deficiency, lexatumumab or the combination. Results Methionine depletion sensitized TNBC cells to lexatumumab-induced caspase activation and apoptosis by increasing TRAIL-R2 mRNA and cell surface expression. MCF-10A cells transformed by oncogenic H-Ras, but not untransformed cells, and matrix-detached TNBC cells were highly sensitive to the combination of lexatumumab and methionine depletion. Proteomics analyses revealed that MAGED2, which has been reported to reduce TRAIL-R2 expression, was suppressed by methionine stress. Silencing MAGED2 recapitulated features of methionine deprivation, including enhanced mRNA and cell surface expression of TRAIL receptors and increased sensitivity to TRAIL receptor agonists. Dietary methionine deprivation enhanced the antitumor effects of lexatumumab in an orthotopic metastatic TNBC model. Conclusion Methionine depletion exposes a targetable defect in TNBC cells by increasing TRAIL-R2 expression. Our findings provide the foundation for a clinical trial combining dietary methionine restriction and TRAIL-R2 agonists. PMID:25724522

REEPs Are Membrane Shaping Adapter Proteins That Modulate Specific G Protein-Coupled Receptor Trafficking by Affecting ER Cargo Capacity

PubMed Central

Ho, Vincent K.; Angelotti, Timothy

2013-01-01

Receptor expression enhancing proteins (REEPs) were identified by their ability to enhance cell surface expression of a subset of G protein-coupled receptors (GPCRs), specifically GPCRs that have proven difficult to express in heterologous cell systems. Further analysis revealed that they belong to the Yip (Ypt-interacting protein) family and that some REEP subtypes affect ER structure. Yip family comparisons have established other potential roles for REEPs, including regulation of ER-Golgi transport and processing/neuronal localization of cargo proteins. However, these other potential REEP functions and the mechanism by which they selectively enhance GPCR cell surface expression have not been clarified. By utilizing several REEP family members (REEP1, REEP2, and REEP6) and model GPCRs (α2A and α2C adrenergic receptors), we examined REEP regulation of GPCR plasma membrane expression, intracellular processing, and trafficking. Using a combination of immunolocalization and biochemical methods, we demonstrated that this REEP subset is localized primarily to ER, but not plasma membranes. Single cell analysis demonstrated that these REEPs do not specifically enhance surface expression of all GPCRs, but affect ER cargo capacity of specific GPCRs and thus their surface expression. REEP co-expression with α2 adrenergic receptors (ARs) revealed that this REEP subset interacts with and alter glycosidic processing of α2C, but not α2A ARs, demonstrating selective interaction with cargo proteins. Specifically, these REEPs enhanced expression of and interacted with minimally/non-glycosylated forms of α2C ARs. Most importantly, expression of a mutant REEP1 allele (hereditary spastic paraplegia SPG31) lacking the carboxyl terminus led to loss of this interaction. Thus specific REEP isoforms have additional intracellular functions besides altering ER structure, such as enhancing ER cargo capacity, regulating ER-Golgi processing, and interacting with select cargo proteins. Therefore, some REEPs can be further described as ER membrane shaping adapter proteins. PMID:24098485

Synaptic GluN2A and GluN2B Containing NMDA Receptors within the Superficial Dorsal Horn Activated following Primary Afferent Stimulation

PubMed Central

MacDermott, Amy B.

2014-01-01

NMDA receptors are important elements in pain signaling in the spinal cord dorsal horn. They are heterotetramers, typically composed of two GluN1 and two of four GluN2 subunits: GluN2A-2D. Mice lacking some of the GluN2 subunits show deficits in pain transmission yet functional synaptic localization of these receptor subtypes in the dorsal horn has not been fully resolved. In this study, we have investigated the composition of synaptic NMDA receptors expressed in monosynaptic and polysynaptic pathways from peripheral sensory fibers to lamina I neurons in rats. We focused on substance P receptor-expressing (NK1R+) projection neurons, critical for expression of hyperalgesia and allodynia. EAB-318 and (R)-CPP, GluN2A/B antagonists, blocked both monosynaptic and polysynaptic NMDA EPSCs initiated by primary afferent activation by ∼90%. Physiological measurements exploiting the voltage dependence of monosynaptic EPSCs similarly indicated dominant expression of GluN2A/B types of synaptic NMDA receptors. In addition, at synapses between C fibers and NK1R+ neurons, NMDA receptor activation initiated a secondary, depolarizing current. Ifenprodil, a GluN2B antagonist, caused modest suppression of monosynaptic NMDA EPSC amplitudes, but had a widely variable, sometimes powerful, effect on polysynaptic responses following primary afferent stimulation when inhibitory inputs were blocked to mimic neuropathic pain. We conclude that GluN2B subunits are moderately expressed at primary afferent synapses on lamina I NK1R+ neurons, but play more important roles for polysynaptic NMDA EPSCs driven by primary afferents following disinhibition, supporting the view that the analgesic effect of the GluN2B antagonist on neuropathic pain is at least in part, within the spinal cord. PMID:25122884

Cockroach GABAB receptor subtypes: molecular characterization, pharmacological properties and tissue distribution.

PubMed

Blankenburg, S; Balfanz, S; Hayashi, Y; Shigenobu, S; Miura, T; Baumann, O; Baumann, A; Blenau, W

2015-01-01

γ-aminobutyric acid (GABA) is the predominant inhibitory neurotransmitter in the central nervous system (CNS). Its effects are mediated by either ionotropic GABAA receptors or metabotropic GABAB receptors. GABAB receptors regulate, via Gi/o G-proteins, ion channels, and adenylyl cyclases. In humans, GABAB receptor subtypes are involved in the etiology of neurologic and psychiatric disorders. In arthropods, however, these members of the G-protein-coupled receptor family are only inadequately characterized. Interestingly, physiological data have revealed important functions of GABAB receptors in the American cockroach, Periplaneta americana. We have cloned cDNAs coding for putative GABAB receptor subtypes 1 and 2 of P. americana (PeaGB1 and PeaGB2). When both receptor proteins are co-expressed in mammalian cells, activation of the receptor heteromer with GABA leads to a dose-dependent decrease in cAMP production. The pharmacological profile differs from that of mammalian and Drosophila GABAB receptors. Western blot analyses with polyclonal antibodies have revealed the expression of PeaGB1 and PeaGB2 in the CNS of the American cockroach. In addition to the widespread distribution in the brain, PeaGB1 is expressed in salivary glands and male accessory glands. Notably, PeaGB1-like immunoreactivity has been detected in the GABAergic salivary neuron 2, suggesting that GABAB receptors act as autoreceptors in this neuron. Copyright © 2014 Elsevier Ltd. All rights reserved.

Sorting receptor Rer1 controls surface expression of muscle acetylcholine receptors by ER retention of unassembled alpha-subunits.

PubMed

Valkova, Christina; Albrizio, Marina; Röder, Ira V; Schwake, Michael; Betto, Romeo; Rudolf, Rüdiger; Kaether, Christoph

2011-01-11

The nicotinic acetylcholine receptor of skeletal muscle is composed of five subunits that are assembled in a stepwise manner. Quality control mechanisms ensure that only fully assembled receptors reach the cell surface. Here, we show that Rer1, a putative Golgi-ER retrieval receptor, is involved in the biogenesis of acetylcholine receptors. Rer1 is expressed in the early secretory pathway in the myoblast line C2C12 and in mouse skeletal muscle, and up-regulated during myogenesis. Upon down-regulation of Rer1 in C2C12 cells, unassembled acetylcholine receptor α-subunits escape from the ER and are transported to the plasma membrane and lysosomes, where they are degraded. As a result, the amount of fully assembled receptor at the cell surface is reduced. In vivo Rer1 knockdown and genetic inactivation of one Rer1 allele lead to significantly smaller neuromuscular junctions in mice. Our data show that Rer1 is a functionally important unique factor that controls surface expression of muscle acetylcholine receptors by localizing unassembled α-subunits to the early secretory pathway.

Expression of σ receptors of human urinary bladder tumor cells (RT-4 cells) and development of a competitive receptor binding assay for the determination of ligand affinity to human σ(2) receptors.

PubMed

Schepmann, Dirk; Lehmkuhl, Kirstin; Brune, Stefanie; Wünsch, Bernhard

2011-07-15

A selective competitive binding assay for the determination of the affinity of compounds to the human σ(2) receptor using 96-well multiplates and a solid state scintillator was developed. In the assay system, [(3)H]ditolylguanidine (DTG) was used as radioligand and membrane homogenates from human RT-4 cells physiologically expressing σ(2) receptors served as receptor material. In order to block the interaction of the unselective radioligand [(3)H]DTG with σ(1) receptors, all experiments were performed in the presence of the σ(1) selective ligand (+)-pentazocine. The density of σ(2) receptors of the cells was analyzed by a saturation experiment with [(3)H]DTG. The radioligand [(3)H]DTG was bound to a single, saturable site on human σ(2) receptors, resulting in a B(max) value of 2108±162fmol/mg protein and K(d)-value of 8.3±2.0nM. The expression of competing σ(1) receptors was evaluated by performing a saturation experiment using the σ(1) selective radioligand [(3)H](+)-pentazocine, which resulted in a B(max) value of 279±40fmol/mg protein and K(d) value of 13.4±1.6nM. For validation of the σ(2) binding assay, the K(i)-values of four σ(2) ligands (ditolylguanidine, haloperidol, rimczole and BMY-14802) were determined with RT-4 cell membrane preparations. The K(i) values obtained from these experiments are in good accordance with the K(i)-values obtained with rat liver membrane preparations as receptor material and with K(i) values given in the literature. Copyright © 2011 Elsevier B.V. All rights reserved.

Targeted Type 1 phototherapeutic agents using azido-peptide bioconjugates

NASA Astrophysics Data System (ADS)

Rajagopalan, Raghavan; Achilefu, Samuel I.; Jimenez, Hermo N.; Webb, Elizabeth G.; Schmidt, Michelle A.; Bugaj, Joseph E.; Dorshow, Richard B.

2001-07-01

Five peptides binding to somatostatin and bombesin receptors were conjugated to 4-azido-2,3,4,6-tetrafluorophenylbenzoic acid, a Type 1 photosensitizer, at the N-terminal position. The receptor affinities were determined by competition binding assay using two different pancreatic tumor cell lines, CA20948 and AR42-J, that expresses somatostatin-2 (SST-2) and bombesin receptors receptively. All compounds exhibited high receptor specificity, i.e., the IC50 values ranged between 1.0 to 64.0 nM. These conjugates may be useful for targeted Type 1 phototherapy via the generation of nitrenes at the cell surfaces expressing these receptors.

Effects of repeated 9 and 30-day exposure to extremely low-frequency electromagnetic fields on social recognition behavior and estrogen receptors expression in olfactory bulb of Wistar female rats.

PubMed

Bernal-Mondragón, C; Arriaga-Avila, V; Martínez-Abundis, E; Barrera-Mera, B; Mercado-Gómez, O; Guevara-Guzmán, R

2017-02-01

We investigated the short- and long-term effects of extremely low-frequency electromagnetic fields (EMF) on social recognition behavior and expression of α- and β-estrogen receptors (ER). Rats were exposed to 60-Hz electromagnetic fields for 9 or 30 days and tested for social recognition behavior. Immunohistochemistry and western blot assays were performed to evaluate α- and β-ER expression in the olfactory bulb of intact, ovariectomized (OVX), and ovariectomized+estradiol (E2) replacement (OVX+E2). Ovariectomization showed impairment of social recognition after 9 days of EMF exposure and a complete recovery after E2 replacement and so did those after 30 days. Short EMF exposure increased expression of β-ER in intact, but not in the others. Longer exposure produced a decrease in intact but an increase in OVX and OVX+E2. Our findings suggest a significant role for β-estrogen receptors and a lack of effect for α-estrogen receptors on a social recognition task. EMF: extremely low frequency electromagnetic fields; ERs: estrogen receptors; OB: olfactory bulb; OVX: ovariectomized; OVX + E 2 : ovariectomized + estradiol replacement; IEI: interexposure interval; β-ER: beta estrogen receptor; E 2 : replacement of estradiol; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; WB: Western blot; PBS: phosphate-buffer saline; PB: phosphate-buffer.

Characterization of interleukin-4-stimulated nasal polyp fibroblasts.

PubMed

Steinke, John W; Crouse, Charles D; Bradley, Dewayne; Hise, Kathleen; Lynch, Kevin; Kountakis, Stilianos E; Borish, Larry

2004-02-01

Chronic hyperplastic eosinophilic sinusitis is an inflammatory disease that results in the accumulation of eosinophils, fibroblasts, mast cells, and goblet cells at the site of injury. A common feature of this disease is the presence of nasal polyposis (NP). The current studies were designed to assess the contribution of interleukin (IL)-4 to fibroblast-mediated inflammation in chronic hyperplastic eosinophilic sinusitis/NP. In addition, we hypothesized that cysteinyl leukotrienes (CysLT) may directly influence fibroblast-mediated fibrotic and remodeling pathways in this disorder. Fibroblasts were isolated from NP tissue. All fibroblast lines expressed the IL-4 receptor. IL-4 induced changes in mRNA and protein expression of fibrotic (transforming growth factor-beta1 and -beta2) and inflammatory cytokines and chemokines (IL-6 and CCL11) by fibroblasts as measured by semiquantitative and quantitative polymerase chain reaction, RNase protection assay, and enzyme-linked immunosorbent assay. The expression of CysLT and other proinflammatory lipid receptors on fibroblasts was evaluated. CysLT1 and CysLT2 receptors were not expressed on fibroblasts; however, LPA(1) receptor was constitutively expressed and LPA(2) receptor expression was upregulated by IL-4. The metabolic cascade involved in CysLT synthesis was not expressed in fibroblasts and could not be induced by IL-4 treatment.

Partial agonist/antagonist mouse interleukin-2 proteins indicate that a third component of the receptor complex functions in signal transduction.

PubMed Central

Zurawski, S M; Imler, J L; Zurawski, G

1990-01-01

Some mouse interleukin-2 (mIL-2) proteins with substitutions at residue Gln141 are unable to trigger a maximal biological response. The Asp141 protein induces the lowest maximal response. The Asp141 protein can weakly antagonize the biological activity of mIL-2 and strongly antagonizes the biological activity of active mIL-2 mutant proteins that have defects in interactions with the high affinity receptor. Residue 141 mutant proteins bind with reduced affinity to T cells expressing the high affinity IL-2 receptor, yet bind normally to transfected fibroblasts expressing only the alpha and beta chains of the receptor. These results suggest that a third receptor component is important for both binding and signal transduction. PMID:2249656

Dopamine D2-like receptor signaling suppresses human osteoclastogenesis.

PubMed

Hanami, Kentaro; Nakano, Kazuhisa; Saito, Kazuyoshi; Okada, Yosuke; Yamaoka, Kunihiro; Kubo, Satoshi; Kondo, Masahiro; Tanaka, Yoshiya

2013-09-01

Dopamine, a major neurotransmitter, transmits signals via five different seven-transmembrane G protein-coupled receptors termed D1 to D5. Although the relevance of neuroendocrine system to bone metabolism has been emerging, the precise effects of dopaminergic signaling upon osteoclastogenesis remain unknown. Here, we demonstrate that human monocyte-derived osteoclast precursor cells express all dopamine-receptor subtypes. Dopamine and dopamine D2-like receptor agonists such as pramipexole and quinpirole reduced the formation of TRAP-positive multi-nucleated cells, cathepsin K mRNA expression, and pit formation area in vitro. These inhibitory effects were reversed by pre-treatment with a D2-like receptor antagonist haloperidol or a Gαi inhibitor pertussis toxin, but not with the D1-like receptor antagonist SCH-23390. Dopamine and dopamine D2-like receptor agonists, but not a D1-like receptor agonist, suppressed intracellular cAMP concentration as well as RANKL-meditated induction of c-Fos and NFATc1 mRNA expression in human osteoclast precursor cells. Finally, the dopamine D2-like receptor agonist suppressed LPS-induced osteoclast formation in murine bone marrow culture ex vivo. These findings indicate that dopaminergic signaling plays an important role in bone homeostasis via direct effects upon osteoclast differentiation and further suggest that the clinical use of neuroleptics is likely to affect bone mass. Copyright © 2013 Elsevier Inc. All rights reserved.

Expression of the ERBB Family of Ligands and Receptors in Gastric Cancer.

PubMed

Byeon, Sun-Ju; Lee, Hye Seung; Kim, Min-A; Lee, Byung Lan; Kim, Woo Ho

2017-01-01

Gastric cancer (GC) is the second most common cancer and the third leading cause of cancer-related death in Korea. Alterations in the ERBB (homology to the erythroblastoma viral gene product, v-erbB) receptor family and ERBB-related signaling pathways are frequently observed in GC. However, the roles of the ERBB receptors and their ligands in GC are not well established. We evaluated the expression levels of various ERBB receptor ligands (i.e., heparin-binding epidermal growth factor-like growth factor [HBEGF], transforming growth factor-α [TGFA], amphiregulin [AREG], epiregulin [EREG], epidermal growth factor [EGF], and betacellulin [BTC]) and 3 ERBB family receptors (i.e., epidermal growth factor receptor [EGFR], human EGFR2 [HER2], and ERBB3) in 313 cases of GC using immunohistochemistry, fluorescence in situ hybridization, and mRNA in situ hybridization. A high expression of EGFR, HER2, and ERBB3 was observed in 30, 32, and 27 cases, respectively. A high expression of HBEGF, TGFA, AREG, EREG, EGF, and BTC was observed in 91, 97, 151, 74, 26, and 37 cases, respectively. A high expression of TGFA was associated with better survival, while a high expression of BTC was associated with worse survival. These results were confirmed using Cox proportional hazards analysis. HBEGF, TGFA, AREG, tumor-node-metastasis classification, Lauren's classification, and ERBB3 were significant survival parameters in multivariate analysis. Among the ERBB family receptors and ligands examined, 3 ligands (i.e., TGFA, HBEGF, and AREG) and ERBB3 had a prognostic impact. © 2017 S. Karger AG, Basel.

Identification and Characterization of Receptors for Ion Transport Peptide (ITP) and ITP-like (ITPL) in the Silkworm Bombyx mori*

PubMed Central

Nagai, Chiaki; Mabashi-Asazuma, Hideaki; Nagasawa, Hiromichi; Nagata, Shinji

2014-01-01

Ion transport peptide (ITP) and its alternatively spliced variant, ITP-like (ITPL), are insect peptides that belong to the crustacean hyperglycemic hormone family. These peptides modulate the homeostatic mechanisms for regulating energy metabolism, molting, and reproduction and are specifically conserved in ecdysozoans. Many of the details of the molecular mechanisms by which crustacean hyperglycemic hormone family peptides exert pleiotropy remain to be elucidated, including characterization of their receptors. Here we identified three Bombyx mori orphan neuropeptide G protein-coupled receptors (BNGRs), BNGR-A2, -A24, and -A34, as receptors for ITP and ITPL (collectively referred to as ITPs). BNGR-A2 and -A34 and BNGR-A24 respond to recombinant ITPs, respectively, with EC50 values of 1.1–2.6 × 10−8 m, when expressed in a heterologous expression system. These three candidate BNGRs are expressed at larval B. mori tissues targeted by ITPs, with cGMP elevation observed after exposure to recombinant ITPs. ITPs also increased the cGMP level in B. mori ovary-derived BmN cells via membrane-bound and soluble guanylyl cyclases. The simultaneous knockdown of bngr-A2 and -A34 significantly decreased the response of BmN cells to ITP, whereas knockdown of bngr-A24 led to decreased responses to ITPL. Conversely, transient expression of bngr-A24 potentiated the response of BmN cells to ITPL. An in vitro binding assay showed direct interaction between ITPs and heterologously expressed BNGRs in a ligand-receptor-specific manner. Taken together, these data demonstrate that BNGR-A2 and -A34 are ITP receptors and that BNGR-A24 is an ITPL receptor in B. mori. PMID:25278025

Adipocyte-Derived Hormone Leptin Is a Direct Regulator of Aldosterone Secretion, Which Promotes Endothelial Dysfunction and Cardiac Fibrosis.

PubMed

Huby, Anne-Cécile; Antonova, Galina; Groenendyk, Jake; Gomez-Sanchez, Celso E; Bollag, Wendy B; Filosa, Jessica A; Belin de Chantemèle, Eric J

2015-12-01

In obesity, the excessive synthesis of aldosterone contributes to the development and progression of metabolic and cardiovascular dysfunctions. Obesity-induced hyperaldosteronism is independent of the known regulators of aldosterone secretion, but reliant on unidentified adipocyte-derived factors. We hypothesized that the adipokine leptin is a direct regulator of aldosterone synthase (CYP11B2) expression and aldosterone release and promotes cardiovascular dysfunction via aldosterone-dependent mechanisms. Immunostaining of human adrenal cross-sections and adrenocortical cells revealed that adrenocortical cells coexpress CYP11B2 and leptin receptors. Measurements of adrenal CYP11B2 expression and plasma aldosterone levels showed that increases in endogenous (obesity) or exogenous (infusion) leptin dose-dependently raised CYP11B2 expression and aldosterone without elevating plasma angiotensin II, potassium or corticosterone. Neither angiotensin II receptors blockade nor α and β adrenergic receptors inhibition blunted leptin-induced aldosterone secretion. Identical results were obtained in cultured adrenocortical cells. Enhanced leptin signaling elevated CYP11B2 expression and plasma aldosterone, whereas deficiency in leptin or leptin receptors blunted obesity-induced increases in CYP11B2 and aldosterone, ruling out a role for obesity per se. Leptin increased intracellular calcium, elevated calmodulin and calmodulin-kinase II expression, whereas calcium chelation blunted leptin-mediated increases in CYP11B2, in adrenocortical cells. Mineralocorticoid receptor blockade blunted leptin-induced endothelial dysfunction and increases in cardiac fibrotic markers. Leptin is a newly described regulator of aldosterone synthesis that acts directly on adrenal glomerulosa cells to increase CYP11B2 expression and enhance aldosterone production via calcium-dependent mechanisms. Furthermore, leptin-mediated aldosterone secretion contributes to cardiovascular disease by promoting endothelial dysfunction and the expression of profibrotic markers in the heart. © 2015 American Heart Association, Inc.

Activation of Ventral Tegmental Area 5-HT2C Receptors Reduces Incentive Motivation.

PubMed

Valencia-Torres, Lourdes; Olarte-Sánchez, Cristian M; Lyons, David J; Georgescu, Teodora; Greenwald-Yarnell, Megan; Myers, Martin G; Bradshaw, Christopher M; Heisler, Lora K

2017-06-01

Obesity is primarily due to food intake in excess of the body's energetic requirements, intake that is not only associated with hunger but also the incentive value of food. The 5-hydroxytryptamine 2C receptor (5-HT 2C R) is a target for the treatment of human obesity. Mechanistically, 5-HT 2C Rs are positioned to influence both homeostatic feeding circuits within the hypothalamus and reward circuits within the ventral tegmental area (VTA). Here we investigated the role of 5-HT 2C Rs in incentive motivation using a mathematical model of progressive ratio (PR) responding in mice. We found that the 5-HT 2C R agonist lorcaserin significantly reduced both ad libitum chow intake and PR responding for chocolate pellets and increased c-fos expression in VTA 5-HT 2C R expressing γ-aminobutyric acid (GABA) neurons, but not 5-HT 2C R expressing dopamine (DA) neurons. We next adopted a chemogenetic approach using a 5-HT 2C R CRE line to clarify the function of subset of 5-HT 2C receptor expressing VTA neurons in the modulation of appetite and food-motivated behavior. Activation of VTA 5-HT 2C receptor expressing neurons significantly reduced ad libitum chow intake, operant responding for chocolate pellets, and the incentive value of food. In contrast, chemogenetic inhibition of VTA 5-HT 2C receptor expressing neurons had no effect on the feeding behavior. These results indicate that activation of the subpopulation of 5-HT 2C R neurons within the VTA is sufficient to significantly reduce homeostatic feeding and effort-based intake of palatable food, and that this subset has an inhibitory role in motivational processes. These findings are relevant to the treatment of obesity.

Activation of Ventral Tegmental Area 5-HT2C Receptors Reduces Incentive Motivation

PubMed Central

Valencia-Torres, Lourdes; Olarte-Sánchez, Cristian M; Lyons, David J; Georgescu, Teodora; Greenwald-Yarnell, Megan; Myers, Martin G; Bradshaw, Christopher M; Heisler, Lora K

2017-01-01

Obesity is primarily due to food intake in excess of the body's energetic requirements, intake that is not only associated with hunger but also the incentive value of food. The 5-hydroxytryptamine 2C receptor (5-HT2CR) is a target for the treatment of human obesity. Mechanistically, 5-HT2CRs are positioned to influence both homeostatic feeding circuits within the hypothalamus and reward circuits within the ventral tegmental area (VTA). Here we investigated the role of 5-HT2CRs in incentive motivation using a mathematical model of progressive ratio (PR) responding in mice. We found that the 5-HT2CR agonist lorcaserin significantly reduced both ad libitum chow intake and PR responding for chocolate pellets and increased c-fos expression in VTA 5-HT2CR expressing γ-aminobutyric acid (GABA) neurons, but not 5-HT2CR expressing dopamine (DA) neurons. We next adopted a chemogenetic approach using a 5-HT2CRCRE line to clarify the function of subset of 5-HT2C receptor expressing VTA neurons in the modulation of appetite and food-motivated behavior. Activation of VTA 5-HT2C receptor expressing neurons significantly reduced ad libitum chow intake, operant responding for chocolate pellets, and the incentive value of food. In contrast, chemogenetic inhibition of VTA 5-HT2C receptor expressing neurons had no effect on the feeding behavior. These results indicate that activation of the subpopulation of 5-HT2CR neurons within the VTA is sufficient to significantly reduce homeostatic feeding and effort-based intake of palatable food, and that this subset has an inhibitory role in motivational processes. These findings are relevant to the treatment of obesity. PMID:27882999

Effect of GDNF on depressive-like behavior, spatial learning and key genes of the brain dopamine system in genetically predisposed to behavioral disorders mouse strains.

PubMed

Naumenko, Vladimir S; Kondaurova, Elena M; Bazovkina, Daria V; Tsybko, Anton S; Ilchibaeva, Tatyana V; Khotskin, Nikita V; Semenova, Alina A; Popova, Nina K

2014-11-01

The effect of glial cell line-derived neurotrophic factor (GDNF) on behavior and brain dopamine system in predisposed to depressive-like behavior ASC (Antidepressant Sensitive Cataleptics) mice in comparison with the parental "nondepressive" CBA mice was studied. In 7days after administration (800ng, i.c.v.) GDNF decreased escape latency time and the path traveled to reach hidden platform in Morris water maze in ASC mice. GDNF enhanced depressive-like behavioral traits in both "nondepressive" CBA and "depressive" ASC mice. In CBA mice, GDNF decreased functional response to agonists of D1 (chloro-APB hydrobromide) and D2 (sumanirole maleate) receptors in tail suspension test, reduced D2 receptor gene expression in the substantia nigra and increased monoamine oxydase A (MAO A) gene expression in the striatum. GDNF increased D1 and D2 receptor genes expression in the nucleus accumbens of ASC mice but failed to alter expression of catechol-O-methyltransferase, dopamine transporter, MAO B and tyrosine hydroxylase genes in both investigated mouse strains. Thus, GDNF produced long-term genotype-dependent effect on behavior and the brain dopamine system. GDNF pretreatment (1) reduced D1 and D2 receptors functional responses and D2 receptor gene expression in s. nigra of CBA mice; (2) increased D1 and D2 receptor genes expression in n. accumbens of ASC mice and (3) improved spatial learning in ASC mice. GDNF enhanced depressive-like behavior both in CBA and ASC mice. The data suggest that genetically defined variance in the cross-talk between GDNF and brain dopamine system contributes to the variability of GDNF-induced responses and might be responsible for controversial GDNF effects. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of oxymatrine on sympathoexcitatory reflex induced by myocardial ischemic signaling mediated by P2X₃ receptors in rat SCG and DRG.

PubMed

Li, Guilin; Liu, Shuangmei; Yang, Yang; Xie, Jinyan; Liu, Jun; Kong, Fanjun; Tu, Guihua; Wu, Raoping; Li, Guodong; Liang, Shangdong

2011-04-05

Sympathoexcitatory reflex is characterized by an increase in blood pressure and sympathetic nerve activity. P2X₃ receptors in SCG neurons are involved in increasing sympathoexcitatory reflex after myocardial ischemic (MI) injury. The present study is aimed to explore the effects of oxymatrine (Oxy) on the transmission of myocardial ischemic signaling mediated by P2X₃ receptors in rat superior cervical ganglia (SCG) and cervical dorsal root ganglia (DRG) in the sympathoexcitatory reflex after myocardial ischemic injury. In this study, the expression levels of P2X₃ immunoreactivity, mRNA and protein were analyzed in SCG and DRG neurons by immunohistochemistry, in situ hybridization and Western blotting. The results show that the myocardial ischemic injury induces the increase of the systolic blood pressure and heart rate and upregulates the expression of P2X₃ receptors in SCG and DRG neurons. Upregulated expression of P2X₃ receptors in SCG and DRG neurons subsequently leads to the aggravated sympathoexcitatory reflex. Oxymatrine reduces the systolic blood pressure and heart rate in myocardial ischemic rats. After myocardial ischemic rats are treated with oxymatrine, the expression levels of P2X₃ immunoreactivity, mRNA and protein are lower than those in myocardial ischemic rats. Oxymatrine may decrease the expression of P2X₃ receptor and depress the aggravated sympathoexcitatory reflex induced by the nociceptive transmission of myocardial ischemic injury via P2X₃ receptors of rat SCG and DRG neurons. Copyright © 2011 Elsevier Inc. All rights reserved.

The CB₁ cannabinoid receptor signals striatal neuroprotection via a PI3K/Akt/mTORC1/BDNF pathway.

PubMed

Blázquez, C; Chiarlone, A; Bellocchio, L; Resel, E; Pruunsild, P; García-Rincón, D; Sendtner, M; Timmusk, T; Lutz, B; Galve-Roperh, I; Guzmán, M

2015-10-01

The CB1 cannabinoid receptor, the main molecular target of endocannabinoids and cannabis active components, is the most abundant G protein-coupled receptor in the mammalian brain. In particular, the CB1 receptor is highly expressed in the basal ganglia, mostly on terminals of medium-sized spiny neurons, where it plays a key neuromodulatory function. The CB1 receptor also confers neuroprotection in various experimental models of striatal damage. However, the assessment of the physiological relevance and therapeutic potential of the CB1 receptor in basal ganglia-related diseases is hampered, at least in part, by the lack of knowledge of the precise mechanism of CB1 receptor neuroprotective activity. Here, by using an array of pharmacological, genetic and pharmacogenetic (designer receptor exclusively activated by designer drug) approaches, we show that (1) CB1 receptor engagement protects striatal cells from excitotoxic death via the phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin complex 1 pathway, which, in turn, (2) induces brain-derived neurotrophic factor (BDNF) expression through the selective activation of BDNF gene promoter IV, an effect that is mediated by multiple transcription factors. To assess the possible functional impact of the CB1/BDNF axis in a neurodegenerative-disease context in vivo, we conducted experiments in the R6/2 mouse, a well-established model of Huntington's disease, in which the CB1 receptor and BDNF are known to be severely downregulated in the dorsolateral striatum. Adeno-associated viral vector-enforced re-expression of the CB1 receptor in the dorsolateral striatum of R6/2 mice allowed the re-expression of BDNF and the concerted rescue of the neuropathological deficits in these animals. Collectively, these findings unravel a molecular link between CB1 receptor activation and BDNF expression, and support the relevance of the CB1/BDNF axis in promoting striatal neuron survival.

P2 receptor stimulation induces amyloid precursor protein production and secretion in rat cortical astrocytes.

PubMed

Tran, Minh D

2011-04-04

Amyloid precursor protein (APP) is ubiquitously expressed in a variety of tissues but is predominantly expressed in the brain. The expression of APP has been well studied in neurons but little is known about its presence in astrocytes. The study presented here shows that purinergic signaling is involved in the production and secretion of APP in primary cultures of rat cortical astrocytes. Extracellular ATP caused an increase in APP production and release in a time- and concentration-dependent manner and was inhibited by antagonists of P2 receptors. Further agonist and antagonist studies revealed involvement of P2Y2 and P2Y4 receptors in nucleotide-stimulated production and release of APP. In addition, signaling studies with various protein kinase inhibitors demonstrated that blockade of mitogen-activated protein kinases, but not Akt, inhibited nucleotide-stimulated APP expression and release. These results indicate that APP production and secretion can be regulated by activation of P2Y2/4 receptors coupled to protein kinase signaling pathways and suggest that astrocytes can be a potential source of APP. Published by Elsevier Ireland Ltd.

A novel Toll like receptor with two TIR domains (HcToll-2) is involved in regulation of antimicrobial peptide gene expression of Hyriopsis cumingii.

PubMed

Ren, Qian; Lan, Jiang-Feng; Zhong, Xue; Song, Xiao-Jun; Ma, Fei; Hui, Kai-Min; Wang, Wen; Yu, Xiao-Qiang; Wang, Jin-Xing

2014-07-01

Animal Toll-like receptors (TLRs) are involved in innate immunity. Toll proteins are generally transmembrane proteins. In this study, an atypical Toll-like receptor (HcToll-2) was identified from the triangle-shell pearl mussel Hyriopsis cumingii, which belongs to phylum Mollusca. Unlike the typical Toll like receptors with extracellular leucine-rich repeats (LRRs), transmembrane, and intracellular Toll/interleukin-1 receptor (TIR) domains, HcToll-2 has two homologous TIR domains located at the C-terminal (designated as HcTIR1 and HcTIR2) and lacks a transmembrane domain. Phylogenetic analysis showed that HcTIR1 was clustered with TIR of sea anemone Toll, and HcTIR2 was clustered with TIR of Drosophila Toll. HcToll-2 mRNA could be detected in the hepatopancreas and was upregulated after challenge with Escherichia coli and Staphylococcus aureus. Recombinant HcLRR protein with GST tag could bind to bacteria and also to LPS and PGN. Over-expression of both HcTIR1 and HcTIR2 induced drosomycin genes in Drosophila S2 cells. RNAi analysis showed that HcToll-2 was required for the expression of theromacin, which is a cysteine-rich antimicrobial peptide (AMP) gene. This research is the first report of an atypical Toll-like receptor HcToll-2 involved in antibacterial immunity through induction of AMP expression. Copyright © 2014 Elsevier Ltd. All rights reserved.

Kappa2 opioid receptor subtype binding requires the presence of the DOR-1 gene.

PubMed

Ansonoff, Michael A; Wen, Ting; Pintar, John E

2010-01-01

Over the past several years substantial evidence has documented that opioid receptor homo- and heterodimers form in cell lines expressing one or more of the opioid receptors. We used opioid receptor knockout mice to determine whether in vivo pharmacological characteristics of kappa1 and kappa2 opioid receptors changed following knockout of specific opioid receptors. Using displacement of the general opioid ligand diprenorphine, we observed that occupancy or knockout of the DOR-1 gene increases the binding density of kappa1 receptors and eliminates kappa2 receptors in crude membrane preparations while the total density of kappa opioid binding sites is unchanged. Further, the analgesic potency of U69,593 in cumulative dose response curves is enhanced in mice lacking the DOR-1 gene. These results demonstrate that the DOR-1 gene is required for the expression of the kappa2 opioid receptor subtype and are consistent with the possibility that a KOR-1/DOR-1 heterodimer mediates kappa2 pharmacology.

Lhx2 Determines Odorant Receptor Expression Frequency in Mature Olfactory Sensory Neurons

PubMed Central

Zhang, Guangfan; Titlow, William B.; Biecker, Stephanie M.; Stromberg, Arnold J.

2016-01-01

Abstract A developmental program of epigenetic repression prepares each mammalian olfactory sensory neuron (OSN) to strongly express one allele from just one of hundreds of odorant receptor (OR) genes, but what completes this process of OR gene choice by driving the expression of this allele is incompletely understood. Conditional deletion experiments in mice demonstrate that Lhx2 is necessary for normal expression frequencies of nearly all ORs and all trace amine-associated receptors, irrespective of whether the deletion of Lhx2 is initiated in immature or mature OSNs. Given previous evidence that Lhx2 binds OR gene control elements, these findings indicate that Lhx2 is directly involved in driving OR expression. The data also support the conclusion that OR expression is necessary to allow immature OSNs to complete differentiation and become mature. In contrast to the robust effects of conditional deletion of Lhx2, the loss of Emx2 has much smaller effects and more often causes increased expression frequencies. Lhx2:Emx2 double mutants show opposing effects on Olfr15 expression that reveal independent effects of these two transcription factors. While Lhx2 is necessary for OR expression that supports OR gene choice, Emx2 can act differently; perhaps by helping to control the availability of OR genes for expression. PMID:27822500

[Expression and significance of wingless-type MMTV integration site family, member 5A/receptor tyrosine kinase-like orphan receptor 2 in the rat dental follicle].

PubMed

Liping, Wang; Boqi, Li; Qi, Wang; Xiaomin, Tie; Yishan, Liu

2016-08-01

To observe the expression of wingless-type MMTV integration site family, member 5A (Wnt5A)/receptor tyrosine kinase-like orphan receptor 2 (Ror2) signal in the dental follicle cells during the normal eruption of the teeth as well as to explore the relationship between the expression of dental follicle cells and the formation of mature osteoclasts and eruption of the teeth. The mandibulars of 1-13 d old SD rats were separated to observe the growth and develop-ment of the teeth and alveolar bone through hematoxylin-eosin(HE) staining. Ror2 and Wnt5A expressions in rat dental follicle were also observed through immunohistochemistry. Dental follicle cells from the lower first intact molar germs of 5-6-day old SD rats were separated and cultured. On the second day after birth, the dental follicle began to differentiate into periodontal tissues, but no obvious changes were observed in the alveolar bone one to three days after birth. On the fourth day, the number of osteoclasts increased significantly. The results of immunohistochemistry showed that Wnt5A was not significantly expressed in rat dental follicle tissues before the fourth day, but positive expression was expressed in the next day and continued to express to thirteenth days. Ror2 was expressed in the rat dental follicle at postnatal days 1-3, but weak expression was found in days 4-13. Wnt5A and Ror2 expressions in the process of tooth eruption have specific time distributions, suggesting that these expressions may participate in the regulation of the eruption of the teeth.

Dopamine D2-receptor activation elicits akinesia, rigidity, catalepsy, and tremor in mice expressing hypersensitive α4 nicotinic receptors via a cholinergic-dependent mechanism

PubMed Central

Zhao-Shea, Rubing; Cohen, Bruce N.; Just, Herwig; McClure-Begley, Tristan; Whiteaker, Paul; Grady, Sharon R.; Salminen, Outi; Gardner, Paul D.; Lester, Henry A.; Tapper, Andrew R.

2010-01-01

Recent studies suggest that high-affinity neuronal nicotinic acetylcholine receptors (nAChRs) containing α4 and β2 subunits (α4β2*) functionally interact with G-protein-coupled dopamine (DA) D2 receptors in basal ganglia. We hypothesized that if a functional interaction between these receptors exists, then mice expressing an M2 point mutation (Leu9′Ala) rendering α4 nAChRs hypersensitive to ACh may exhibit altered sensitivity to a D2-receptor agonist. When challenged with the D2R agonist, quinpirole (0.5–10 mg/kg), Leu9′Ala mice, but not wild-type (WT) littermates, developed severe, reversible motor impairment characterized by rigidity, catalepsy, akinesia, and tremor. While striatal DA tissue content, baseline release, and quinpirole-induced DA depletion did not differ between Leu9′Ala and WT mice, quinpirole dramatically increased activity of cholinergic striatal interneurons only in mutant animals, as measured by increased c-Fos expression in choline acetyltransferase (ChAT)-positive interneurons. Highlighting the importance of the cholinergic system in this mouse model, inhibiting the effects of ACh by blocking muscarinic receptors, or by selectively activating hypersensitive nAChRs with nicotine, rescued motor symptoms. This novel mouse model mimics the imbalance between striatal DA/ACh function associated with severe motor impairment in disorders such as Parkinson’s disease, and the data suggest that a D2R–α4*-nAChR functional interaction regulates cholinergic interneuron activity.—Zhao-Shea, R., Cohen, B. N., Just, H., McClure-Begley, T., Whiteaker, P., Grady, S. R., Salminen, O., Gardner, P. D., Lester, H. A., Tapper, A. R. Dopamine D2-receptor activation elicits akinesia, rigidity, catalepsy, and tremor in mice expressing hypersensitive α4 nicotinic receptors via a cholinergic-dependent mechanism. PMID:19720621

Role of atypical chemokine receptor ACKR2 in experimental oral squamous cell carcinogenesis.

PubMed

da Silva, Janine Mayra; Dos Santos, Tálita Pollyanna Moreira; Saraiva, Adriana Machado; Fernandes de Oliveira, Ana Laura; Garlet, Gustavo Pompermaier; Batista, Aline Carvalho; de Mesquita, Ricardo Alves; Russo, Remo Castro; da Silva, Tarcília Aparecida

2018-03-14

Chemokines and chemokine receptors are critical in oral tumourigenesis. The atypical chemokine receptor ACKR2 is a scavenger of CC chemokines controlling the availability of these molecules at tumour sites, but the role of ACKR2 in the context of oral carcinogenesis is unexplored. In this study, wild-type (WT) and ACKR2 deficient mice (ACKR2 -/- ) were treated with chemical carcinogen 4-nitroquinoline-1-oxide (4NQO) for induction of oral carcinogenesis. Tongues were collected for macro and microscopic analysis and to evaluate the expression of ACKRs, CC chemokines and its receptors, inflammatory cytokines, angiogenic factors, adhesion molecules and extracellular matrix components. An increased expression of ACKR2 in squamous cell carcinoma (SCC) lesions of 4NQO-treated WT mice was observed. No significant differences were seen in the ACKR1, ACKR3 and ACKR4 mRNA expression comparing SCC lesions from WT and ACKR2 -/- treated mice. Significantly higher expression of CCL2, IL-6 and IL-17 was detected in ACKR2 -/- treated mice. In contrast, the expression of other CC-chemokines, and receptors, angiogenic factors, adhesion molecules and extracellular matrix components were similarly increased in SCC lesions of both groups. Clinical and histopathological analysis revealed no differences in inflammatory cell recruitment and in the SCC incidence comparing WT and ACKR2 -/- treated mice. The results suggest that ACKR2 expression regulates inflammation in tumour-microenvironment but the absence of ACKR2 does not impact chemically-induced oral carcinogenesis. Copyright © 2018 Elsevier Ltd. All rights reserved.

Kokumi Substances, Enhancers of Basic Tastes, Induce Responses in Calcium-Sensing Receptor Expressing Taste Cells

PubMed Central

Maruyama, Yutaka; Yasuda, Reiko; Kuroda, Motonaka; Eto, Yuzuru

2012-01-01

Recently, we reported that calcium-sensing receptor (CaSR) is a receptor for kokumi substances, which enhance the intensities of salty, sweet and umami tastes. Furthermore, we found that several γ-glutamyl peptides, which are CaSR agonists, are kokumi substances. In this study, we elucidated the receptor cells for kokumi substances, and their physiological properties. For this purpose, we used Calcium Green-1 loaded mouse taste cells in lingual tissue slices and confocal microscopy. Kokumi substances, applied focally around taste pores, induced an increase in the intracellular Ca2+ concentration ([Ca2+]i) in a subset of taste cells. These responses were inhibited by pretreatment with the CaSR inhibitor, NPS2143. However, the kokumi substance-induced responses did not require extracellular Ca2+. CaSR-expressing taste cells are a different subset of cells from the T1R3-expressing umami or sweet taste receptor cells. These observations indicate that CaSR-expressing taste cells are the primary detectors of kokumi substances, and that they are an independent population from the influenced basic taste receptor cells, at least in the case of sweet and umami. PMID:22511946

Deuteration and selective labeling of alanine methyl groups of β2-adrenergic receptor expressed in a baculovirus-insect cell expression system.

PubMed

Kofuku, Yutaka; Yokomizo, Tomoki; Imai, Shunsuke; Shiraishi, Yutaro; Natsume, Mei; Itoh, Hiroaki; Inoue, Masayuki; Nakata, Kunio; Igarashi, Shunsuke; Yamaguchi, Hideyuki; Mizukoshi, Toshimi; Suzuki, Ei-Ichiro; Ueda, Takumi; Shimada, Ichio

2018-03-08

G protein-coupled receptors (GPCRs) exist in equilibrium between multiple conformations, and their populations and exchange rates determine their functions. However, analyses of the conformational dynamics of GPCRs in lipid bilayers are still challenging, because methods for observations of NMR signals of large proteins expressed in a baculovirus-insect cell expression system (BVES) are limited. Here, we report a method to incorporate methyl- 13 C 1 H 3 -labeled alanine with > 45% efficiency in highly deuterated proteins expressed in BVES. Application of the method to the NMR observations of β 2 -adrenergic receptor in micelles and in nanodiscs revealed the ligand-induced conformational differences throughout the transmembrane region of the GPCR.

Comparison of the functional potencies of ropinirole and other dopamine receptor agonists at human D2(long), D3 and D4.4 receptors expressed in Chinese hamster ovary cells

PubMed Central

Coldwell, Martyn C; Boyfield, Izzy; Brown, Tony; Hagan, Jim J; Middlemiss, Derek N

1999-01-01

The aim of the present study was to characterize functional responses to ropinirole, its major metabolites in man (SKF-104557 (4-[2-(propylamino)ethyl]-2-(3H) indolone), SKF-97930 (4-carboxy-2-(3H) indolone)) and other dopamine receptor agonists at human dopamine D2(long) (hD2), D3 (hD3) and D4.4 (hD4) receptors separately expressed in Chinese hamster ovary cells using microphysiometry.All the receptor agonists tested (ropinirole, SKF-104557, SKF-97930, bromocriptine, lisuride, pergolide, pramipexole, talipexole, dopamine) increased extracellular acidification rate in Chinese hamster ovary clones expressing the human D2, D3 or D4 receptor. The pEC50s of ropinirole at hD2, hD3 and hD4 receptors were 7.4, 8.4 and 6.8, respectively. Ropinirole is therefore at least 10 fold selective for the human dopamine D3 receptor over the other D2 receptor family members.At the hD2 and hD3 dopamine receptors all the compounds tested were full agonists as compared to quinpirole. Talipexole and the ropinirole metabolite, SKF-104557, were partial agonists at the hD4 receptor.Bromocriptine and lisuride had a slow onset of agonist action which precluded determination of EC50s.The rank order of agonist potencies was dissimilar to the rank order of radioligand binding affinities at each of the dopamine receptor subtypes. Functional selectivities of the dopamine receptor agonists, as measured in the microphysiometer, were less than radioligand binding selectivities.The results show that ropinirole is a full agonist at human D2, D3 and D4 dopamine receptors. SKF-104557 the major human metabolite of ropinirole, had similar radioligand binding affinities to, but lower functional potencies than, the parent compound. PMID:10455328

Control of yeast mating signal transduction by a mammalian. beta. sub 2 -adrenergic receptor and G sub s. alpha. subunit

DOE Office of Scientific and Technical Information (OSTI.GOV)

King, K.; Caron, M.G.; Lefkowitz, R.J.

1990-10-05

To facilitate functional and mechanistic studies of receptor-G protein interactions by expression of the human {beta}{sub 2}-adrenergic receptor (h{beta}-AR) has been expressed in Saccharomyces cerevisiae. This was achieved by placing a modified h{beta}-AR gene under control of the galactose-inducible GAL1 promoter. After induction by galactose, functional h{beta}-AR was expressed at a concentration several hundred times as great as that found in any human tissue. As determined from competitive ligand binding experiments, h{beta}-AR expressed in yeast displayed characteristic affinities, specificity, and stereoselectivity. Partial activation of the yeast pheromone response pathway by {beta}-adrenergic receptor agonists was achieved in cells coexpressing h{beta}-AR andmore » a mammalian G protein (G{sub s}) {alpha} subunit - demonstrating that these components can couple to each other and to downstream effectors when expressed in yeast. This in vivo reconstitution system provides a new approach for examining ligand binding and G protein coupling to cell surface receptors.« less

Human microRNA-1245 down-regulates the NKG2D receptor in natural killer cells and impairs NKG2D-mediated functions

PubMed Central

Espinoza, J. Luis; Takami, Akiyoshi; Yoshioka, Katsuji; Nakata, Katsuya; Sato, Tokiharu; Kasahara, Yoshihito; Nakao, Shinji

2012-01-01

Background NKG2D is an activating receptor expressed by natural killer and T cells, which have crucial functions in tumor and microbial immunosurveillance. Several cytokines have been identified as modulators of NKG2D receptor expression. However, little is known about NKG2D gene regulation. In this study, we found that microRNA 1245 attenuated the expression of NKG2D in natural killer cells. Design and Methods We investigated the potential interactions between the 3′-untranslated region of the NKG2D gene and microRNA as well as their functional roles in the regulation of NKG2D expression and cytotoxicity in natural killer cells. Results Transforming growth factor-β1, a major negative regulator of NKG2D expression, post-transcriptionally up-regulated mature microRNA-1245 expression, thus down-regulating NKG2D expression and impairing NKG2D-mediated immune responses in natural killer cells. Conversely, microRNA-1245 down-regulation significantly increased the expression of NKG2D expression in natural killer cells, resulting in more efficient NKG2D-mediated cytotoxicity. Conclusions These results reveal a novel NKG2D regulatory pathway mediated by microRNA-1245, which may represent one of the mechanisms used by transforming growth factor-β1 to attenuate NKG2D expression in natural killer cells. PMID:22491735

Serotonin 2C receptors in pro-opiomelanocortin neurons regulate energy and glucose homeostasis.

PubMed

Berglund, Eric D; Liu, Chen; Sohn, Jong-Woo; Liu, Tiemin; Kim, Mi Hwa; Lee, Charlotte E; Vianna, Claudia R; Williams, Kevin W; Xu, Yong; Elmquist, Joel K

2013-12-01

Energy and glucose homeostasis are regulated by central serotonin 2C receptors. These receptors are attractive pharmacological targets for the treatment of obesity; however, the identity of the serotonin 2C receptor-expressing neurons that mediate the effects of serotonin and serotonin 2C receptor agonists on energy and glucose homeostasis are unknown. Here, we show that mice lacking serotonin 2C receptors (Htr2c) specifically in pro-opiomelanocortin (POMC) neurons had normal body weight but developed glucoregulatory defects including hyperinsulinemia, hyperglucagonemia, hyperglycemia, and insulin resistance. Moreover, these mice did not show anorectic responses to serotonergic agents that suppress appetite and developed hyperphagia and obesity when they were fed a high-fat/high-sugar diet. A requirement of serotonin 2C receptors in POMC neurons for the maintenance of normal energy and glucose homeostasis was further demonstrated when Htr2c loss was induced in POMC neurons in adult mice using a tamoxifen-inducible POMC-cre system. These data demonstrate that serotonin 2C receptor-expressing POMC neurons are required to control energy and glucose homeostasis and implicate POMC neurons as the target for the effect of serotonin 2C receptor agonists on weight-loss induction and improved glycemic control.

Regulation of G-protein coupled receptor traffic by an evolutionary conserved hydrophobic signal.

PubMed

Angelotti, Tim; Daunt, David; Shcherbakova, Olga G; Kobilka, Brian; Hurt, Carl M

2010-04-01

Plasma membrane (PM) expression of G-protein coupled receptors (GPCRs) is required for activation by extracellular ligands; however, mechanisms that regulate PM expression of GPCRs are poorly understood. For some GPCRs, such as alpha2c-adrenergic receptors (alpha(2c)-ARs), heterologous expression in non-native cells results in limited PM expression and extensive endoplasmic reticulum (ER) retention. Recently, ER export/retentions signals have been proposed to regulate cellular trafficking of several GPCRs. By utilizing a chimeric alpha(2a)/alpha(2c)-AR strategy, we identified an evolutionary conserved hydrophobic sequence (ALAAALAAAAA) in the extracellular amino terminal region that is responsible in part for alpha(2c)-AR subtype-specific trafficking. To our knowledge, this is the first luminal ER retention signal reported for a GPCR. Removal or disruption of the ER retention signal dramatically increased PM expression and decreased ER retention. Conversely, transplantation of this hydrophobic sequence into alpha(2a)-ARs reduced their PM expression and increased ER retention. This evolutionary conserved hydrophobic trafficking signal within alpha(2c)-ARs serves as a regulator of GPCR trafficking.

Uncommon endocytic and trafficking pathway of the natural killer cell CD94/NKG2A inhibitory receptor.

PubMed

Masilamani, Madhan; Narayanan, Sriram; Prieto, Martha; Borrego, Francisco; Coligan, John E

2008-06-01

The CD94/NKG2A inhibitory receptor, expressed by natural killer and T cells, is constantly exposed to its HLA-E ligand expressed by surrounding cells. Ligand exposure often induces receptor downregulation. For CD94/NKG2A, this could potentiate activation receptor(s) induced responses to normal bystander cells. We investigated CD94/NKG2A endocytosis and found that it occurs by an amiloride-sensitive, Rac1-dependent macropinocytic-like process; however, it does not require clathrin, dynamin, ADP ribosylation factor-6, phosphoinositide-3 kinase or the actin cytoskeleton. Once endocytosed, CD94/NKG2A traffics to early endosomal antigen 1(+), Rab5(+) early endosomes. It does appear in Rab4(+) early/sorting endosome, but, in the time period examined, fails to reach Rab11(+) recycling or Rab7(+) late endosomes or lysosome-associated membrane protein-1(+) lysosomes. These results indicate that CD94/NKG2A utilizes a previously undescribed endocytic mechanism coupled with an abbreviated trafficking pattern, perhaps to insure surface expression.

Melatonin receptors in a pleuronectiform species, Solea senegalensis: Cloning, tissue expression, day-night and seasonal variations.

PubMed

Confente, Francesca; Rendón, María Carmen; Besseau, Laurence; Falcón, Jack; Muñoz-Cueto, José A

2010-06-01

Melatonin receptors are expressed in neural and peripheral tissues and mediate melatonin actions on the synchronization of circadian and circannual rhythms. In this study we have cloned three melatonin receptor subtypes (MT1, MT2 and Mel1c) in the Senegalese sole and analyzed their central and peripheral tissue distribution. The full-length MT1 (1452 nt), MT2 (1728 nt) and Mel1c (1980 nt) cDNAs encode different proteins of 345, 373, 355 amino acids, respectively. They were mainly expressed in retina, brain and pituitary, but MT1 was also expressed in gill, liver, intestine, kidney, spleen, heart and skin. At peripheral level, MT2 expression was only evident in gill, kidney and skin whereas Mel1c expression was restricted to the muscle and skin. This pattern of expression was not markedly different between sexes or among the times of day analyzed. The real-time quantitative PCR analyses showed that MT1 displayed higher expression at night than during the day in the retina and optic tectum. Seasonal MT1 expression was characterized by higher mRNA levels in spring and autumn equinoxes for the retina, and in winter and summer solstices for the optic tectum. An almost similar expression profile was found for MT2, but differences were less conspicuous. No day-night differences in MT1 and MT2 expression were observed in the pituitary but a seasonal variation was detected, being mRNA levels higher in summer for both receptors. Mel1c expression did not exhibit significant day-night variation in retina and optic tectum but showed seasonal variations, with higher transcript levels in summer (optic tectum) and autumn (retina). Our results suggest that day-night and seasonal variations in melatonin receptor expression could also be mediating circadian and circannual rhythms in sole. Copyright 2010 Elsevier Inc. All rights reserved.

Attenuation of alpha2A-adrenergic receptor expression in neonatal rat brain by RNA interference or antisense oligonucleotide reduced anxiety in adulthood.

PubMed

Shishkina, G T; Kalinina, T S; Dygalo, N N

2004-01-01

Brain alpha2-adrenergic receptors (alpha2-ARs) have been implicated in the regulation of anxiety, which is associated with stress. Environmental treatments during neonatal development could modulate the level of brain alpha2-AR expression and alter anxiety in adults, suggesting possible involvement of these receptors in early-life programming of anxiety state. The present study was undertaken to determine whether the reduction of the expression of A subtype of these receptors most abundant in the neonatal brain affects anxiety-related behavior in adulthood. We attenuated the expression of alpha2A-ARs during neonatal life by two different sequence specific approaches, antisense technology and RNA interference. Treatment of rats with the antisense oligodeoxynucleotide or short interfering RNA (siRNA) against alpha2A-ARs on the days 2-4 of their life, produced a marked acute decrease in the levels of both alpha2A-AR mRNA and [3H]RX821002 binding sites in the brainstem into which drugs were injected. The decrease of alpha2A-AR expression in the neonatal brainstem influenced the development of this receptor system in the brain regions as evidenced by the increased number of [3H]RX821002 binding sites in the hypothalamus of adult animals with both neonatal alpha2A-AR knockdown treatments; also in the frontal cortex of antisense-treated, and in the hippocampus of siRNA-treated adult rats. These adult animals also demonstrated a decreased anxiety in the elevated plus-maze as evidenced by an increased number of the open arm entries, greater proportion of time spent in the open arms, and more than a two-fold increase in the number of exploratory head dips. The results provide the first evidence that the reduction in the brain expression of a gene encoding for alpha2A-AR during neonatal life led to the long-term neurochemical and behavioral alterations. The data suggests that alterations in the expression of the receptor-specific gene during critical periods of brain development may be involved in early-life programming of anxiety-related behavior.

In Vitro Interleukin-1 and 2 Production and Interleukin 2 Receptor Expression in the Rhesus Monkey

NASA Technical Reports Server (NTRS)

Schmitt, Didier A.; Sonnenfeld, Gerald; Husson, David; Tkaczuk, Jean; Andre, Eric; Schaffar, Laurance

1996-01-01

Anti-human monoclonal antibodies were used to detect and quantify interleukins-1 and 2 and interleukin-2 receptor expression in peripheral blood mononuclear cells from a rhesus monkey. Interleukin-1 production could be induced by phorbol esters (PMA) and was potentiated by phytohemagglutinin (PHA). Interleukin-2 secretion could also be induced by the combination of PHA and PMA, but only weakly with PHA alone. Interleukin-2 receptor expression was present in a subpopulation of unstimulated lymphocytes and could be enhanced by PHA or PMA. These data show once again that the rhesus monkey immune system is cross-reactive with the human one and that rhesus macaque could be a good model to study interleukin therapy.

Expression of messenger molecules and receptors in rat and human sphenopalatine ganglion indicating therapeutic targets.

PubMed

Steinberg, Anna; Frederiksen, Simona D; Blixt, Frank W; Warfvinge, Karin; Edvinsson, Lars

2016-12-01

Migraine and Cluster Headache (CH) are two primary headaches with severe disease burden. The disease expression and the mechanisms involved are poorly known. In some attacks of migraine and in most attacks of CH, there is a release of vasoactive intestinal peptide (VIP) originating from parasympathetic cranial ganglia such as the sphenopalatine ganglion (SPG). Patients suffering from these diseases are often deprived of effective drugs. The aim of the study was to examine the localization of the botulinum toxin receptor element synaptic vesicle glycoprotein 2A (SV-2A) and the vesicular docking protein synaptosomal-associated protein 25 (SNAP25) in human and rat SPG. Additionally the expression of the neurotransmitters pituitary adenylate cyclase activating polypeptide (PACAP-38), nitric oxide synthase (nNOS), VIP and 5-hydroxttryptamine subtype receptors (5-HT1B,1D,1F) were examined. SPG from adult male rats and from humans, the later removed at autopsy, were prepared for immunohistochemistry using specific antibodies against neurotransmitters, 5-HT1B,1D,1F receptors, and botulinum toxin receptor elements. We found that the selected neurotransmitters and 5-HT receptors were expressed in rat and human SPG. In addition, we found SV2-A and SNAP25 expression in both rat and human SPG. We report that all three 5-HT receptors studied occur in neurons and satellite glial cells (SGCs) of the SPG. 5-HT1B receptors were in addition found in the walls of intraganglionic blood vessels. Recent focus on the SPG has emphasized the role of parasympathetic mechanisms in the pathophysiology of mainly CH. The development of next generation's drugs and treatment of cranial parasympathetic symptoms, mediated through the SPG, can be modulated by treatment with BoNT-A and 5-HT receptor agonists.

Estrogen receptor mRNA expression patterns in the liver and ovary of female rainbow trout over a complete reproductive cycle

PubMed Central

Nagler, James J.; Cavileer, Timothy D.; Verducci, Joseph S.; Schultz, Irvin R.; Hook, Sharon E.; Hayton, William L.

2012-01-01

Estrogens are critical hormones involved in reproduction and need to bind to estrogen receptors in target organs for biological activity. Fishes have two distinct estrogen receptor subtypes, alpha (α) and beta (β), with variable combinations of additional isoforms of each subtype dependent on the history of genome duplication within a taxon. The comparative expression patterns of estrogen receptor isoforms during the female reproductive cycle will provide important insights into the unique function and importance of each. The purpose of this study was to measure the mRNAs for the four estrogen receptor isoforms (erα1, erα2, erβ1, erβ2) in the liver and ovary of adult, female rainbow trout over the course of an annual reproductive cycle. The expression of estrogen receptor mRNA isoforms was measured by quantitative real-time RT-PCR. Several reproductive indices (gonadosomatic index, maximum oocyte diameter, plasma estradiol-17β, plasma vitellogenin, and ovulation) were also quantified for comparison and used in a correlation analysis to examine any inter-relationships. Of the four isoforms, the expression of erα1 was highest in the liver, and had a significant positive correlation with liver erβ1 expression. Liver expression of erα2 mRNA was the lowest, but showed a significant positive correlation with maximum oocyte diameter in the ovary. The pattern of the erβ isoforms in liver was one of initially elevated mRNA expression followed by a gradual decrease as reproductive development proceeded. In the ovary the erβ1 isoform had the highest mRNA expression of all estrogen receptor isoforms, at the beginning of the reproductive cycle, but then decreased afterward. Both ovarian erβ isoforms had a significant positive correlation with one another. In contrast, erα2 mRNA expression showed a high maximum level in the ovary near the end of the cycle along with a significant positive correlation with plasma estradiol-17β levels; the highest gonadosomatic indices, maximum oocyte diameter, and vitellogenin levels occurred then too. PMID:22732076

5-HT1A receptor gene silencers Freud-1 and Freud-2 are differently expressed in the brain of rats with genetically determined high level of fear-induced aggression or its absence.

PubMed

Kondaurova, Elena M; Ilchibaeva, Tatiana V; Tsybko, Anton S; Kozhemyakina, Rimma V; Popova, Nina K; Naumenko, Vladimir S

2016-09-01

Serotonin 5-HT1A receptor is known to play a crucial role in the mechanisms of genetically defined aggression. In its turn, 5-HT1A receptor functional state is under control of multiple factors. Among others, transcriptional factors Freud-1 and Freud-2 are known to be involved in the repression of 5-HT1A receptor gene expression. However, implication of these factors in the regulation of behavior is unclear. Here, we investigated the expression of 5-HT1A receptor and silencers Freud-1 and Freud-2 in the brain of rats selectively bred for 85 generations for either high level of fear-induced aggression or its absence. It was shown that Freud-1 and Freud-2 levels were different in aggressive and nonaggressive animals. Freud-1 protein level was decreased in the hippocampus, whereas Freud-2 protein level was increased in the frontal cortex of highly aggressive rats. There no differences in 5-HT1A receptor gene expression were found in the brains of highly aggressive and nonaggressive rats. However, 5-HT1A receptor protein level was decreased in the midbrain and increased in the hippocampus of highly aggressive rats. These data showed the involvement of Freud-1 and Freud-2 in the regulation of genetically defined fear-induced aggression. However, these silencers do not affect transcription of the 5-HT1A receptor gene in the investigated rats. Our data indicate the implication of posttranscriptional rather than transcriptional regulation of 5-HT1A receptor functional state in the mechanisms of genetically determined aggressive behavior. On the other hand, the implication of other transcriptional regulators for 5-HT1A receptor gene in the mechanisms of genetically defined aggression could be suggested. Copyright © 2016 Elsevier B.V. All rights reserved.

Mutated CaV2.1 channels dysregulate CASK/P2X3 signaling in mouse trigeminal sensory neurons of R192Q Cacna1a knock-in mice

PubMed Central

2013-01-01

Background ATP-gated P2X3 receptors of sensory ganglion neurons are important transducers of pain as they adapt their expression and function in response to acute and chronic nociceptive signals. The present study investigated the role of calcium/calmodulin-dependent serine protein kinase (CASK) in controlling P2X3 receptor expression and function in trigeminal ganglia from Cacna1a R192Q-mutated knock-in (KI) mice, a genetic model for familial hemiplegic migraine type-1. Results KI ganglion neurons showed more abundant CASK/P2X3 receptor complex at membrane level, a result that likely originated from gain-of-function effects of R192Q-mutated CaV2.1 channels and downstream enhanced CaMKII activity. The selective CaV2.1 channel blocker ω-Agatoxin IVA and the CaMKII inhibitor KN-93 were sufficient to return CASK/P2X3 co-expression to WT levels. After CASK silencing, P2X3 receptor expression was decreased in both WT and KI ganglia, supporting the role of CASK in P2X3 receptor stabilization. This process was functionally observed as reduced P2X3 receptor currents. Conclusions We propose that, in trigeminal sensory neurons, the CASK/P2X3 complex has a dynamic nature depending on intracellular calcium and related signaling, that are enhanced in a transgenic mouse model of genetic hemiplegic migraine. PMID:24294842

Insulin decreases expression of the pro-inflammatory receptor Proteinase-Activated Receptor-2 on human airway epithelial cells.

PubMed

Gandhi, Vivek D; Palikhe, Nami Shrestha; Hamza, Shereen M; Dyck, Jason R B; Buteau, Jean; Vliagoftis, Harissios

2018-06-08

The authors show that insulin, a hormone with anti-inflammatory properties, decreases the expression of a pro-inflammatory receptor on airway epithelial cells. This observation may explain the heightened respiratory inflammation seen in patients with metabolic syndrome. Copyright © 2018. Published by Elsevier Inc.

Ubiquitylation of an internalized NK cell receptor by Triad3A disrupts sustained NF-κB signaling1

PubMed Central

Shahjahan Miah, S. M.; Purdy, Amanda K.; Rodin, Nicholas B.; MacFarlane, Alexander W.; Oshinsky, Jennifer; Alvarez-Arias, Diana A.; Campbell, Kerry S.

2011-01-01

KIR2DL4 (2DL4, CD158d) is a unique killer cell Ig-like receptor (KIR) expressed on human NK cells, which stimulates cytokine production, but mechanisms regulating its expression and function are poorly understood. By yeast two-hybrid screening, we identified the E3 ubiquitin ligase, Triad3A, as an interaction partner for the 2DL4 cytoplasmic domain. The protein interaction was confirmed in vivo, and Triad3A expression induced polyubiquitylation and degradation of 2DL4. Overexpression of Triad3A selectively abrogated cytokine-producing function of 2DL4, while Triad3A shRNA reversed ubiquitylation and restored cytokine production. Expression of Triad3A in an NK cell line did not affect receptor surface expression, internalization, or early signaling, but significantly reduced receptor turnover and suppressed sustained NF-κB activation. 2DL4 endocytosis was found to be vital to stimulate cytokine production, and Triad3A expression diminished localization of internalized receptor in early endosomes. Our results reveal a critical role for endocytosed 2DL4 receptor to generate sustained NF-κB signaling and drive cytokine production. We conclude that Triad3A is a key negative regulator of sustained 2DL4-mediated NF-κB signaling from internalized 2DL4, which functions by promoting ubiquitylation and degradation of endocytosed receptor from early endosomes. “This is an author-produced version of a manuscript accepted for publication in The Journal of Immunology (The JI). The American Association of Immunologists, Inc. (AAI), publisher of The JI, holds the copyright to this manuscript. This version of the manuscript has not yet been copyedited or subjected to editorial proofreading by The JI; hence, it may differ from the final version published in The JI (online and in print). AAI (The JI) is not liable for errors or omissions in this author-produced version of the manuscript or in any version derived from it by the U.S. National Institutes of Health or any other third party. The final, citable version of record can be found at www.jimmunol.org.” PMID:21270397

Inhibition of G protein-coupled P2Y2 receptor induced analgesia in a rat model of trigeminal neuropathic pain.

PubMed

Li, Na; Lu, Zhan-ying; Yu, Li-hua; Burnstock, Geoffrey; Deng, Xiao-ming; Ma, Bei

2014-03-18

ATP and P2X receptors play important roles in the modulation of trigeminal neuropathic pain, while the role of G protein-coupled P2Y₂ receptors and the underlying mechanisms are less clear. The threshold and frequency of action potentials, fast inactivating transient K+ channels (IA) are important regulators of membrane excitability in sensory neurons because of its vital role in the control of the spike onset. In this study, pain behavior tests, QT-RT-PCR, immunohistochemical staining, and patch-clamp recording, were used to investigate the role of P2Y₂ receptors in pain behaviour. In control rats: 1) UTP, an agonist of P2Y₂/P2Y₄ receptors, caused a significant decrease in the mean threshold intensities for evoking action potentials and a striking increase in the mean number of spikes evoked by TG neurons. 2) UTP significantly inhibited IA and the expression of Kv1.4, Kv3.4 and Kv4.2 subunits in TG neurons, which could be reversed by the P2 receptor antagonist suramin and the ERK antagonist U0126. In ION-CCI (chronic constriction injury of infraorbital nerve) rats: 1) mRNA levels of Kv1.4, Kv3.4 and Kv4.2 subunits were significantly decreased, while the protein level of phosphorylated ERK was significantly increased. 2) When blocking P2Y₂ receptors by suramin or injection of P2Y2R antisense oligodeoxynucleotides both led to a time- and dose-dependent reverse of allodynia in ION-CCI rats. 3) Injection of P2Y₂ receptor antisense oligodeoxynucleotides induced a pronounced decrease in phosphorylated ERK expression and a significant increase in Kv1.4, Kv3.4 and Kv4.2 subunit expression in trigeminal ganglia. Our data suggest that inhibition of P2Y₂ receptors leads to down-regulation of ERK-mediated phosphorylation and increase of the expression of I(A)-related Kv channels in trigeminal ganglion neurons, which might contribute to the clinical treatment of trigeminal neuropathic pain.

Development of N-Methyl-D-Aspartate Receptor Subunits in Avian Auditory Brainstem

PubMed Central

TANG, YE-ZHONG; CARR, CATHERINE E.

2012-01-01

N-methyl-D-aspartate (NMDA) receptor subunit-specific probes were used to characterize developmental changes in the distribution of excitatory amino acid receptors in the chicken’s auditory brainstem nuclei. Although NR1 subunit expression does not change greatly during the development of the cochlear nuclei in the chicken (Tang and Carr [2004] Hear. Res 191:79 – 89), there are significant developmental changes in NR2 subunit expression. We used in situ hybridization against NR1, NR2A, NR2B, NR2C, and NR2D to compare NR1 and NR2 expression during development. All five NMDA subunits were expressed in the auditory brainstem before embryonic day (E) 10, when electrical activity and synaptic responses appear in the nucleus magnocellularis (NM) and the nucleus laminaris (NL). At this time, the dominant form of the receptor appeared to contain NR1 and NR2B. NR2A appeared to replace NR2B by E14, a time that coincides with synaptic refinement and evoked auditory responses. NR2C did not change greatly during auditory development, whereas NR2D increased from E10 and remained at fairly high levels into adulthood. Thus changes in NMDA NR2 receptor subunits may contribute to the development of auditory brainstem responses in the chick. PMID:17366608

A unique gene expression signature associated with serotonin 2C receptor RNA editing in the prefrontal cortex and altered in suicide.

PubMed

Di Narzo, Antonio Fabio; Kozlenkov, Alexey; Roussos, Panos; Hao, Ke; Hurd, Yasmin; Lewis, David A; Sibille, Etienne; Siever, Larry J; Koonin, Eugene; Dracheva, Stella

2014-09-15

Editing of the pre-mRNA for the serotonin receptor 2C (5-HT2CR) by site-specific adenosine deamination (A-to-I pre-mRNA editing) substantially increases the functional plasticity of this key neurotransmitter receptor and is thought to contribute to homeostatic mechanisms in neurons. 5-HT2CR mRNA editing generates up to 24 different receptor isoforms. The extent of editing correlates with 5-HT2CR functional activity: more highly edited isoforms exhibit the least function. Altered 5-HT2CR editing has been reported in postmortem brains of suicide victims. We report a comparative analysis of the connections among 5-HT2CR editing, genome-wide gene expression and DNA methylation in suicide victims, individuals with major depressive disorder and non-psychiatric controls. The results confirm previous findings of an overrepresentation of highly edited mRNA variants (which encode hypoactive 5-HT2CR receptors) in the brains of suicide victims. A large set of genes for which the expression level is associated with editing was detected. This signature set of editing-associated genes is significantly enriched for genes that are involved in synaptic transmission, genes that are preferentially expressed in neurons, and genes whose expression is correlated with the level of DNA methylation. Notably, we report that the link between 5-HT2CR editing and gene expression is disrupted in suicide victims. The results suggest that the postulated homeostatic function of 5-HT2CR editing is dysregulated in individuals who committed suicide. Published by Oxford University Press 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Identification, expression, and pharmacology of a Cys{sub 23}-Ser{sub 23} substitution in the human 5-HT{sub 2C} receptor gene (HTR2C)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lappalainen, J.; Ozaki, N.; Goldman, D.

1995-05-20

The function of brain serotonin-2C (5-HT{sub 2C}) receptors, including behavioral and neurochemical responses to 5-HT{sub 2C} agonist challenge, has been suggested to be abnormal in individuals with neuropsychiatric disorders. Thus, it is important to identify polymorphisms and functional variants within this gene. Using SSCP analysis, the authors identified a Cys{sub 23}-Ser{sub 23} substitution (designated 5-HT{sub 2Ccys} and 5-HT{sub 2Cser}) in the first hydrophobic region of the human 5-HT{sub 2C} receptor. Allele frequencies in unrelated Caucasians were 0.13 and 0.87 for 5-HT{sub 2Cser} and 5-HT{sub 2Ccys}, respectively. DNAs from informative CEPH families were typed for this polymorphism and analyzed with respectmore » to 20 linked markers on the X chromosome. Linkage analysis placed the 5-HT{sub 2C} receptor gene (HTR2C) on Xq24. To evaluate whether this amino acid substitution causes a variant function of this receptor, recombinant human 5-HT{sub 2Ccys} and 5-HT{sub 2Cser} receptors were expressed in Xenopus oocytes and tested for responses to 5-HT using electrophysiological techniques. Concentration-response curves for 5-HT were not significantly different in oocytes expressing either form of the receptor, suggesting that the 5-HT{sub 2Ccys} and 5-HT{sub 2Cser} receptor proteins may not differ in their responses to serotonin under baseline physiological conditions. 43 refs., 3 figs., 1 tab.« less

Sex and seasonal differences in mRNA expression of estrogen receptor α (ESR1) in red-sided garter snakes (Thamnophis sirtalis parietalis).

PubMed

Ashton, Sydney E; Vernasco, Ben J; Moore, Ignacio T; Parker, M Rockwell

2018-05-25

Estrogens are important regulators of reproductive physiology including sexual signal expression and vitellogenesis. For the regulation to occur, the hormone must bind and activate receptors in target tissues, and expression of the receptors can vary by sex and/or season. By simultaneously comparing circulating hormone levels with receptor expression, a more complete understanding of hormone action can be gained. Our study species, the red-sided garter snake (Thamnophis sirtalis parietalis), provides an excellent opportunity to study the interaction between sex steroid hormones and receptor expression in addition to sexual dimorphism and seasonality. During the spring mating season, male garter snakes rely exclusively on the female's skin-based, estrogen-dependent sex pheromone to direct courtship. Males can be stimulated to produce this sexual attractiveness pheromone by treatment with estradiol (E 2 ), which also induces male vitellogenesis. Estrogen receptors (ESRs) are required to transduce the effects of estrogens, thus we used quantitative RT-PCR to analyze expression of ESR alpha (ERα; gene ESR1) mRNA in the skin and liver of wild caught male and female garter snakes across simulated spring and fall conditions in the laboratory. While ESR1 was present in the skin of both sexes, there were no sex or seasonal differences in expression levels. Liver expression of ESR1, however, was sexually dimorphic, with females showing greatest expression in fall when circulating E 2 concentrations were lowest. There were no statistically significant correlations between E 2 and ESR1 expression. Our data suggest that the skin of both sexes is sensitive to estrogen signaling and thus the production of sex pheromone is dependent on bioavailable levels of E 2 . Female expression of ESR1 in the liver may increase in the fall to prime energy storage mechanisms required for vitellogenesis the following year. Copyright © 2018 Elsevier Inc. All rights reserved.

Mechanism of H2 histamine receptor dependent modulation of body temperature and neuronal activity in the medial preoptic nucleus

PubMed Central

Tabarean, Iustin V.; Sanchez-Alavez, Manuel; Sethi, Jasmine

2012-01-01

Histamine is involved in the central control of arousal, circadian rhythms and metabolism. The preoptic area, a region that contains thermoregulatory neurons is the main locus of histamine modulation of body temperature. Here we report that in mice histamine activates H2 subtype receptors in the medial preoptic nucleus (MPON) and induces hyperthermia. We also found that a population of glutamatergic MPON neurons express H2 receptors and are excited by histamine or H2 specific agonists. The agonists decreased the input resistance of the neuron and increased the depolarizing “sag” observed during hyperpolarizing current injections. Furthermore, at −60 mV holding potential activation of H2 receptors induced an inward current that was blocked by ZD7288, a specific blocker of the hyperpolarization activated cationic current (Ih). Indeed, activation of H2 receptors resulted in increased Ih amplitude in response to hyperpolarizing voltage steps and a depolarizing shift in its voltage-dependent activation. The neurons excited by H2 specific agonism expressed the HCN1 and HCN2 channel subunits. Our data indicate that at the level of the MPON histamine influences thermoregulation by increasing the firing rate of glutamatergic neurons that express H2 receptors. PMID:22366077

Characterization of dopamine D1 and D2 receptor-expressing neurons in the mouse hippocampus.

PubMed

Gangarossa, Giuseppe; Longueville, Sophie; De Bundel, Dimitri; Perroy, Julie; Hervé, Denis; Girault, Jean-Antoine; Valjent, Emmanuel

2012-12-01

The hippocampal formation is part of an anatomical system critically involved in learning and memory. Increasing evidence suggests that dopamine plays an important role in learning and memory as well as in several forms of synaptic plasticity. However, the precise identification of neuronal populations expressing D1 or D2 dopamine receptors within the hippocampus is still lacking. To clarify this issue, we used BAC transgenic mice expressing enhanced green fluorescent protein (EGFP) under the control of the promoter of dopamine D1 or D2 receptors. In Drd1a-EGFP mice, sparse GFP-expressing neurons were detected among glutamatergic projecting neurons of the granular layer of the dentate gyrus and GABAergic interneurons located in the hilus. A dense immunofluorescence was observed in the outer and medial part of the molecular layer of the dentate gyrus as well as in the inner part of the molecular layer of CA1 corresponding to the terminals of pyramidal neurons of the entorhinal cortex defining the perforant and the temporo-ammonic pathway respectively. Finally, scattered D1 receptor-expressing neurons were also identified as GABAergic interneurons in the CA3/CA1 fields of the hippocampus. In Drd2-EGFP transgenic mice, GFP was exclusively detected in the glutamatergic mossy cells located in the polymorphic layer of the dentate gyrus. This pattern was confirmed in Drd2-Cre mice crossed with NLS-LacZ-Tau(mGFP) :LoxP and RCE:LoxP reporter lines. Our results demonstrate that D1 and D2 receptor-expressing neurons are strictly segregated in the mouse hippocampus. By clarifying the identity of D1 and D2 receptor-expressing neurons in the hippocampus, this study establishes a basis for future investigations aiming at elucidating their roles in the hippocampal network. Copyright © 2012 Wiley Periodicals, Inc.

Tachykinins and tachykinin receptors in human uterus.

PubMed

Patak, Eva; Candenas, M Luz; Pennefather, Jocelyn N; Ziccone, Sebastian; Lilley, Alison; Martín, Julio D; Flores, Carlos; Mantecón, Antonio G; Story, Margot E; Pinto, Francisco M

2003-06-01

(1) Studies were undertaken to determine the nature of the receptors mediating contractile effects of tachykinins in the uteri of nonpregnant women, and to analyse the expression of preprotachykinins (PPT), tachykinin receptors and the cell-surface peptidase, neprilysin (NEP), in the myometrium from pregnant and nonpregnant women. (2) The neurokinin B (NKB) precursor PPT-B was expressed in higher levels in the myometrium from nonpregnant than from pregnant women. Faint expression of PPT-A mRNA was detectable in the myometrium from nonpregnant but not pregnant women. PPT-C, the gene encoding the novel tachykinin peptide hemokinin-1 (HK-1), was present in trace amounts in the uteri from both pregnant and nonpregnant women. (3) Tachykinin NK(2) receptors were more strongly expressed in tissues from nonpregnant than from pregnant women. NK(1) receptor mRNA was present in low levels in tissues from both pregnant and nonpregnant women. A low abundance transcript corresponding to the NK(3) receptor was present only in tissues from nonpregnant women. (4) The mRNA expression of the tachykinin-degrading enzyme NEP was lower in tissues from nonpregnant than from pregnant women. (5) Substance P (SP), neurokinin A (NKA) and NKB, in the presence of the peptidase inhibitors thiorphan, captopril and bestatin, produced contractions of myometrium from nonpregnant women. The order of potency was NKA>SP>/=NKB. The potency of NKA was unchanged in the absence of peptidase inhibitors. (6) The tachykinin NK(2) receptor-selective agonist [Lys(5)MeLeu(9)Nle(10)]NKA(4-l0) was approximately equipotent with NKA, but the tachykinin NK(1) and NK(3) receptor-selective agonists [Sar(9)Met(O(2))(11)]SP and [MePhe(7)]NKB were ineffective in the myometrium from nonpregnant women. (7) The uterotonic effects of [Lys(5)MeLeu(9)Nle(10)]NKA(4-10) were antagonized by the tachykinin NK(2) receptor-selective antagonist SR48968. Neither atropine, nor phentolamine nor tetrodotoxin affected responses to [Lys(5)MeLeu(9)Nle(10)]NKA(4-10). (8) These data are consistent with a role of tachykinins in the regulation of human uterine function, and reinforce the importance of NK(2) receptors in the regulation of myometrial contraction.

Expression of transforming growth factor alpha and epidermal growth factor receptor messenger RNA in neoplastic and nonneoplastic human kidney tissue.

PubMed

Mydlo, J H; Michaeli, J; Cordon-Cardo, C; Goldenberg, A S; Heston, W D; Fair, W R

1989-06-15

Using Northern blot analysis, we have demonstrated that mRNA for transforming growth factor alpha (TGF-alpha) was expressed in five malignant kidney tissue specimens but was not detected in their autologous nonneoplastic homologues. In addition, the expression of epidermal growth factor (EGF) receptor mRNA in these malignant tissues was 2- to 3-fold greater than in nontransformed tissues. In two cases examined using immunohistochemistry, we were able to correlate the increased expression of the mRNA with an increase in protein expression. Since TGF-alpha is known to bind to the EGF receptor, the finding of an increased expression of both TGF-alpha and EGF receptor mRNA in kidney tumor tissue suggests that interaction between TGF-alpha and the EGF receptor may play a role in promoting transformation and/or proliferation of kidney neoplasms, perhaps by an autocrine mechanism.

AT1 expression in human urethral stricture tissue.

PubMed

Siregar, Safendra; Parardya, Aga; Sibarani, Jupiter; Romdan, Tjahjodjati; Adi, Kuncoro; Hernowo, Bethy S; Yantisetiasti, Anglita

2017-01-01

Urethral stricture has a high recurrence rate. There is a common doctrine stating that "once a stricture, always a stricture". This fibrotic disease pathophysiology, pathologically characterized by excessive production, deposition and contraction of extracellular matrix is unknown. Angiotensin II type 1 (AT 1 ) receptor primarily induces angiogenesis, cellular proliferation and inflammatory responses. AT 1 receptors are also expressed in the fibroblasts of hypertrophic scars, whereas angiotensin II (AngII) regulates DNA synthesis in hypertrophic scar fibroblasts through a negative cross talk between AT 1 and angiotensin II type 2 (AT 2 ) receptors, which might contribute to the formation and maturation of human hypertrophic scars. This study was conducted to determine the expression of AT 1 receptors in urethral stricture tissues. Urethral stricture tissues were collected from patients during anastomotic urethroplasty surgery. There were 24 tissue samples collected in this study with 2 samples of normal urethra for the control group. Immunohistochemistry study was performed to detect the presence of AT 1 receptor expression. Data were analyzed using Mann-Whitney U test, and statistical analysis was performed with SPSS version 20. This study showed that positive staining of AT 1 receptor was found in all urethral stricture tissues (n=24). A total of 8.33% patients had low intensity, 41.67% had moderate intensity and 50% had high intensity of AT 1 receptors, while in the control group, 100% patients had no intensity of AT 1 receptors. Using the Mann-Whitney U test, it was found that urethral stricture tissue had a higher intensity of AT 1 receptors than normal urethral tissue with a p -value = 0.012. The results showed that AT 1 receptor had a higher intensity in the urethral stricture tissue and that AT 1 receptor may play an important role in the development of urethral stricture.

Homologous upregulation of sst2 somatostatin receptor expression in the rat arcuate nucleus in vivo.

PubMed

Tannenbaum, G S; Turner, J; Guo, F; Videau, C; Epelbaum, J; Beaudet, A

2001-07-01

In vitro studies using various cell systems have provided conflicting results regarding homologous regulation of somatostatin (SRIH) receptors, and information on whether SRIH regulates the expression of its own receptors in vivo is lacking. In the present study we examined, by in situ hybridization, the effects of pretreatment with the sst2-preferring SRIH analog, octreotide, in vivo, on mRNA levels of two SRIH receptor subtypes, sst1 and sst2, in rat brain and pituitary. (125)I-[DTrp(8)]-SRIH binding was also measured in these regions. Three hours after the iv injection of 50 microg octreotide to conscious adult male rats, there was a 46% increase (p < 0.01) in the labeling density of sst2 mRNA-expressing cells in the hypothalamic arcuate nucleus compared to normal saline-pretreated controls, but not in any of the other brain regions examined. Computer-assisted image analysis revealed that 3 h exposure to octreotide significantly (p < 0.01) augmented both the number and labeling density of sst2 mRNA-expressing cells in the arcuate nucleus, compared to those in saline-treated controls. By contrast, within the anterior pituitary gland, in vivo exposure to octreotide did not affect the expression of sst2 mRNA. No changes in sst1 mRNA-expressing cells were observed after octreotide treatment in any of the regions measured, indicating that the observed effects were homologous, i.e. specific of the receptor subtype stimulated. Octreotide pretreatment was also without effect on the density of (125)I-[DTrp(8)]-SRIH binding in either the arcuate nucleus or pituitary. These results demonstrate, for the first time, that SRIH preexposure in vivo upregulates the expression of a subtype of its own receptors, sst2, within the central nervous system. They further suggest that pretreatment with SRIH in vivo does not cause sst2 receptor desensitization in arcuate nucleus and pituitary. Such homologous regulatory mechanisms may play an important role in the neuroendocrine control of growth hormone (GH) secretion by the arcuate nucleus. Copyright 2001 S. Karger AG, Basel

Airway lipoxin A4 generation and lipoxin A4 receptor expression are decreased in severe asthma.

PubMed

Planagumà, Anna; Kazani, Shamsah; Marigowda, Gautham; Haworth, Oliver; Mariani, Thomas J; Israel, Elliot; Bleecker, Eugene R; Curran-Everett, Douglas; Erzurum, Serpil C; Calhoun, William J; Castro, Mario; Chung, Kian Fan; Gaston, Benjamin; Jarjour, Nizar N; Busse, William W; Wenzel, Sally E; Levy, Bruce D

2008-09-15

Airway inflammation is common in severe asthma despite antiinflammatory therapy with corticosteroids. Lipoxin A(4) (LXA(4)) is an arachidonic acid-derived mediator that serves as an agonist for resolution of inflammation. Airway levels of LXA(4), as well as the expression of lipoxin biosynthetic genes and receptors, in severe asthma. Samples of bronchoalveolar lavage fluid were obtained from subjects with asthma and levels of LXA(4) and related eicosanoids were measured. Expression of lipoxin biosynthetic genes was determined in whole blood, bronchoalveolar lavage cells, and endobronchial biopsies by quantitative polymerase chain reaction, and leukocyte LXA(4) receptors were monitored by flow cytometry. Individuals with severe asthma had significantly less LXA(4) in bronchoalveolar lavage fluids (11.2 +/- 2.1 pg/ml) than did subjects with nonsevere asthma (150.1 +/- 38.5 pg/ml; P < 0.05). In contrast, levels of cysteinyl leukotrienes were increased in both asthma cohorts compared with healthy individuals. In severe asthma, 15-lipoxygenase-1 mean expression was decreased fivefold in bronchoalveolar lavage cells. In contrast, 15-lipoxgenase-1 was increased threefold in endobronchial biopsies, but expression of both 5-lipoxygenase and 15-lipoxygenase-2 in these samples was decreased. Cyclooxygenase-2 expression was decreased in all anatomic compartments sampled in severe asthma. Moreover, LXA(4) receptor gene and protein expression were significantly decreased in severe asthma peripheral blood granulocytes. Mechanisms underlying pathological airway responses in severe asthma include lipoxin underproduction with decreased expression of lipoxin biosynthetic enzymes and receptors. Together, these results indicate that severe asthma is characterized, in part, by defective lipoxin counterregulatory signaling circuits.

Hepatocytes express functional NOD1 and NOD2 receptors: A role for NOD1 in hepatocyte CC and CXC chemokine production

PubMed Central

Scott, Melanie J.; Chen, Christine; Sun, Qian; Billiar, Timothy R.

2010-01-01

Background & Aims NOD-like receptors are recently described cytosolic pattern recognition receptors. NOD1 and NOD2 are members of this family that recognize bacterial cell wall components, diaminopimelic acid and muramyl dipeptide, respectively. Both NOD1 and NOD2 have been associated with many inflammatory diseases, although their role in liver inflammation and infection has not been well studied. Materials and Methods We investigated the role of NOD receptors in mouse liver by assessing expression and activation of NOD1 and NOD2 in liver and primary isolated hepatocytes from C57BL/6 mice. Results Both NOD1 and NOD2 mRNA and protein were highly expressed in hepatocytes and liver. RIP2, the main signaling partner for NODs, was also expressed. Stimulation of hepatocytes with NOD1 ligand (C12-iEDAP) induced NFκB activation, activation of MAP kinases and expression of chemokines CCL5 (RANTES) and CXCL1 (KC). C12-iEDAP also synergized with interferon (IFN)γ to increase iNOS expression and production of nitric oxide. Despite activating NFκB, NOD1 ligand did not upregulate hepatocyte production of the acute phase proteins lipopolysaccharide binding protein, serum amyloid A, or soluble CD14 in cell culture supernatants, or upregulate mRNA expression of lipopolysaccharide binding protein, serum amyloid A, C-reactive protein, or serum amyloid P. NOD2 ligand (MDP) did not activate hepatocytes when given alone, but did synergize with Toll-like receptor ligands, lipopolysaccharide (LPS), and polyI:C to activate NFκB and MAPK. Conclusions All together these data suggest an important role for hepatocyte NOD1 in attracting leukocytes to the liver during infection and for hepatic NLRs to augment innate immune responses to pathogens. PMID:20615568

Pure Δ9-tetrahydrocannabivarin and a Cannabis sativa extract with high content in Δ9-tetrahydrocannabivarin inhibit nitrite production in murine peritoneal macrophages.

PubMed

Romano, Barbara; Pagano, Ester; Orlando, Pierangelo; Capasso, Raffaele; Cascio, Maria Grazia; Pertwee, Roger; Marzo, Vincenzo Di; Izzo, Angelo A; Borrelli, Francesca

2016-11-01

Historical and scientific evidence suggests that Cannabis use has immunomodulatory and anti-inflammatory effects. We have here investigated the effect of the non-psychotropic phytocannabinoid Δ 9 -tetrahydrocannabivarin (THCV) and of a Cannabis sativa extract with high (64.8%) content in THCV (THCV-BDS) on nitric oxide (NO) production, and on cannabinoid and transient receptor potential (TRP) channel expression in lipopolysaccharide (LPS)-stimulated murine peritoneal macrophages. THCV-BDS and THCV exhibited similar affinity in radioligand binding assays for CB 1 and CB 2 receptors, and inhibited, via CB 2 but not CB 1 cannabinoid receptors, nitrite production evoked by LPS in peritoneal macrophages. THCV down-regulated the over-expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and interleukin 1β (IL-1β) proteins induced by LPS. Furthermore, THCV counteracted LPS-induced up-regulation of CB 1 receptors, without affecting the changes in CB 2 , TRPV2 or TRPV4 mRNA expression caused by LPS. Other TRP channels, namely, TRPA1, TRPV1, TRPV3 and TRPM8 were poorly expressed or undetectable in both unstimulated and LPS-challenged macrophages. It is concluded that THCV - via CB 2 receptor activation - inhibits nitrite production in macrophages. The effect of this phytocannabinoid was associated with a down-regulation of CB 1 , but not CB 2 or TRP channel mRNA expression. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characterization of surface interleukin-2 receptor expression on gated populations of peripheral blood mononuclear cells from manatees, Trichechus manatus latirostris.

PubMed

Sweat, J M; Johnson, C M; Marikar, Y; Gibbs, E P

2005-12-15

An in vitro system to determine surface interleukin-2 receptor (IL-2R) expression on mitogen-stimulated peripheral blood mononuclear cells (PBMC) from free-ranging manatees, Trichechus manatus latirostris was developed. Human recombinant IL-2, conjugated with a fluorescein dye was used in conjunction with flow cytometric analysis to determine changes in surface expression of IL-2R at sequential times over a 48-h period of in vitro stimulation. Surface expression of IL-2R was detected on manatee PBMC, which also cross-reacted with an anti-feline pan T-cell marker. An expression index (EI) was calculated by comparing mitogen-activated and non-activated PBMC. Based on side- and forward-scatter properties, flow cytometric analysis showed an increase in the number of larger, more granular "lymphoblasts" following concanavalin A (Con A) stimulation. The appearance of lymphoblasts was correlated with an increase in their surface expression of IL-2 receptors. Surface IL-2R expression, in Con A-stimulated PBMC, was detected at 16 h, peaked at 24-36 h, and began to decrease by 48 h. Characterization of the IL-2R expression should provide additional information on the health status of manatees, and the effect of their sub lethal exposure to brevetoxin.

Blockade of human P2X7 receptor function with a monoclonal antibody.

PubMed

Buell, G; Chessell, I P; Michel, A D; Collo, G; Salazzo, M; Herren, S; Gretener, D; Grahames, C; Kaur, R; Kosco-Vilbois, M H; Humphrey, P P

1998-11-15

A monoclonal antibody (MoAb) specific for the human P2X7 receptor was generated in mice. As assessed by flow cytometry, the MoAb labeled human blood-derived macrophage cells natively expressing P2X7 receptors and cells transfected with human P2X7 but not other P2X receptor types. The MoAb was used to immunoprecipitate the human P2X7 receptor protein, and in immunohistochemical studies on human lymphoid tissue, P2X7 receptor labeling was observed within discrete areas of the marginal zone of human tonsil sections. The antibody also acted as a selective antagonist of human P2X7 receptors in several functional studies. Thus, whole cell currents, elicited by the brief application of 2',3'-(4-benzoyl)-benzoyl-ATP in cells expressing human P2X7, were reduced in amplitude by the presence of the MoAb. Furthermore, preincubation of human monocytic THP-1 cells with the MoAb antagonized the ability of P2X7 agonists to induce the release of interleukin-1beta.

Day-night and reproductive cycle profiles of melatonin receptor, kiss, and gnrh expression in orange-spotted grouper (Epinephelus coioides).

PubMed

Chai, Ke; Liu, Xiaochun; Zhang, Yong; Lin, Haoran

2013-07-01

It is suggested that the MT1 melatonin receptor mediates the effects of melatonin on reproduction in rodents. Three melatonin receptor types, MT1, MT2, and Mel1c, have been identified in fish. To understand the potential roles of each type of melatonin receptor on reproduction, we explored the day-night and reproductive cycle profiles of melatonin receptor, kiss, and gnrh expression in the orange-spotted grouper (Epinephelus coioides). cDNAs encoding melatonin receptors (MT1, MT2, and Mel1c) were first isolated from the brain of the orange-spotted grouper. Quantitative real-time PCR analysis demonstrated that the expression levels of MT1 and MT2 were higher in most of the brain areas and pituitary, while mel1c mRNA was mainly distributed in some peripheral tissues and the pituitary. The expression levels of MT1 were much higher than those of MT2 and mel1c in most of the brain regions, and the day-night expression variations of MT1 were counter to those of kiss2 and gnrh1. Reproductive cycle variations in MT1 daytime expression were different from those for kiss2 and gnrh1, and contrary to ovarian fecundity. Our results suggest that MT1 may modulate gnrh1 expression through kiss2, or may directly influence it. Together, these signal cascades may regulate the seasonal breeding of the orange-spotted grouper. As the day-length variations were consistent with the ovarian fecundity variation observed during the reproductive cycle, we infer that photoperiod affects ovarian development of the orange-spotted grouper through MT1. Copyright © 2013 Wiley Periodicals, Inc.

Expression of bitter taste receptor Tas2r105 in mouse kidney.

PubMed

Liu, Xin; Gu, Fu; Jiang, Li; Chen, Fuxue; Li, Feng

2015-03-20

The kidney is the most important excretory organ in the body and plays an essential role in maintaining homeostasis in vivo by conserving body fluid and electrolytes and removing metabolic waste. In this study, three types of transgenic system were used to investigate the expression of the bitter taste receptor Tas2r105 in mouse renal tissue (Tas2r105-GFP/Cre, Tas2r105-GFP/Cre-DTA and Tas2r105-GFP/Cre-LacZ). The results suggest that bitter taste receptors Tas2r105 and Tas2r106 are expressed in the renal corpuscle and the renal tubule, including the proximal tubule and distal tubule. Expression of α-gustducin, an important component of taste signal transduction, was also detected in mouse kidney. Meanwhile, conditional diphtheria toxin (DTA) expression in Tas2r105+ cells caused an increase in size of the glomerulus and renal tubule, accompanied by a decrease in cell density in the glomerulus. This indicates that Tas2r105+ cells play an important role in maintaining the structure of the glomerulus and renal tubules. Overall, the current study collectively demonstrates that cells labeled by bitter taste receptor expression may play a critical role in controlling human health, and have properties far beyond the original concept of taste perception. Copyright © 2015 Elsevier Inc. All rights reserved.

Effects of adrenal hormones on the expression of adiponectin and adiponectin receptors in adipose tissue, muscle and liver.

PubMed

de Oliveira, Cristiane; Iwanaga-Carvalho, Carla; Mota, João F; Oyama, Lila M; Ribeiro, Eliane B; Oller do Nascimento, Cláudia M

2011-11-01

Adiponectin, an insulin-sensitive hormone that is primarily synthesized in adipose tissue, exerts its effects by binding to two receptors, adipoR1 and adipoR2. Little is known regarding the effects of glucocorticoids on the expression of adiponectin receptors. Male Wistar rats were bilaterally adrenalectomized and treated with dexamethasone (0.2 mg/100 g) twice daily for 3 days. To analyze the potential effects of glucocorticoids, rats received two daily injections of the glucocorticoid receptor antagonist (RU-486, 5.0 mg) over the course of 3 days. Additionally, 3T3-L1 adipocytes and C2C12 myotubes were treated with dexamethasone, adrenaline or RU-486. The gene expression of adiponectin, adipoR1 and adipoR2 was determined by real-time PCR, and protein secretion was examined by Western blotting using lysates from retroperitoneal, epididymal and subcutaneous adipose tissue depots, liver and muscle. In rats, excess glucocorticoids increased the levels of insulin in serum and decreased serum adiponectin concentrations, whereas adrenalectomy decreased the mRNA expression of adiponectin (3-fold) and adipoR2 (7-fold) in epididymal adipose tissue and increased adipoR2 gene expression in muscle (3-fold) compared to control group sham-operated. Dexamethasone treatment did not reverse the effects of adrenalectomy, and glucocorticoid receptor blockade did not reproduce the effects of adrenalectomy. In 3T3-L1 adipocytes, dexamethasone and adrenaline both increased adipoR2 mRNA levels, but RU-486 reduced adipoR2 gene expression in vitro. Dexamethasone treatment induces a state of insulin resistance but does not affect adiponectin receptor expression in adipose tissue. However, the effects of catecholamines on insulin resistance may be due to their effects on adipoR2. Copyright © 2011 Elsevier Inc. All rights reserved.

P2Y receptors and atherosclerosis in apolipoprotein E-deficient mice

PubMed Central

Guns, Pieter-Jan DF; Hendrickx, Jan; Van Assche, Tim; Fransen, Paul; Bult, Hidde

2010-01-01

Background and purpose: P2Y nucleotide receptors are involved in the regulation of vascular tone, smooth muscle cell (SMC) proliferation and inflammatory responses. The present study investigated whether they are involved in atherosclerosis. Experimental approach: mRNA of P2Y receptors was quantified (RT-PCR) in atherosclerotic and plaque-free aorta segments of apolipoprotein E-deficient (apoE–/–) mice. Macrophage activation was assessed in J774 macrophages, and effects of non-selective purinoceptor antagonists on atherosclerosis were evaluated in cholesterol-fed apoE–/– mice. Key results: P2Y6 receptor mRNA was consistently elevated in segments with atherosclerosis, whereas P2Y2 receptor expression remained unchanged. Expression of P2Y1 or P2Y4 receptor mRNA was low or undetectable, and not influenced by atherosclerosis. P2Y6 mRNA expression was higher in cultured J774 macrophages than in cultured aortic SMCs. Furthermore, immunohistochemical staining of plaques demonstrated P2Y6-positive macrophages, but few SMCs, suggesting that macrophage recruitment accounted for the increase in P2Y6 receptor mRNA during atherosclerosis. In contrast to ATP, the P2Y6-selective agonist UDP increased mRNA expression and activity of inducible nitric oxide synthase and interleukin-6 in J774 macrophages; this effect was blocked by suramin (100–300 µM) or pyridoxal-phosphate-6-azophenyl-2′-4′-disulphonic acid (PPADS, 10–30 µM). Finally, 4-week treatment of cholesterol-fed apoE–/– mice with suramin or PPADS (50 and 25 mg·kg−1·day−1 respectively) reduced plaque size, without changing plaque composition (relative SMC and macrophage content) or cell replication. Conclusions and implications: These results suggest involvement of nucleotide receptors, particularly P2Y6 receptors, during atherosclerosis, and warrant further research with selective purinoceptor antagonists or P2Y6 receptor-deficient mice. PMID:20050854

A family of octopamine [corrected] receptors that specifically induce cyclic AMP production or Ca2+ release in Drosophila melanogaster.

PubMed

Balfanz, Sabine; Strünker, Timo; Frings, Stephan; Baumann, Arnd

2005-04-01

In invertebrates, the biogenic-amine octopamine is an important physiological regulator. It controls and modulates neuronal development, circadian rhythm, locomotion, 'fight or flight' responses, as well as learning and memory. Octopamine mediates its effects by activation of different GTP-binding protein (G protein)-coupled receptor types, which induce either cAMP production or Ca(2+) release. Here we describe the functional characterization of two genes from Drosophila melanogaster that encode three octopamine receptors. The first gene (Dmoa1) codes for two polypeptides that are generated by alternative splicing. When heterologously expressed, both receptors cause oscillatory increases of the intracellular Ca(2+) concentration in response to applying nanomolar concentrations of octopamine. The second gene (Dmoa2) codes for a receptor that specifically activates adenylate cyclase and causes a rise of intracellular cAMP with an EC(50) of approximately 3 x 10(-8) m octopamine. Tyramine, the precursor of octopamine biosynthesis, activates all three receptors at > or = 100-fold higher concentrations, whereas dopamine and serotonin are non-effective. Developmental expression of Dmoa genes was assessed by RT-PCR. Overlapping but not identical expression patterns were observed for the individual transcripts. The genes characterized in this report encode unique receptors that display signature properties of native octopamine receptors.

Pharmacological characterization of a β-adrenergic-like octopamine receptor in Plutella xylostella.

PubMed

Huang, Qing-Ting; Ma, Hai-Hao; Deng, Xi-Le; Zhu, Hang; Liu, Jia; Zhou, Yong; Zhou, Xiao-Mao

2018-04-25

The β-adrenergic-like octopamine receptor (OA2B2) belongs to the class of G-protein coupled receptors. It regulates important physiological functions in insects, thus is potentially a good target for insecticides. In this study, the putative open reading frame sequence of the Pxoa2b2 gene in Plutella xylostella was cloned. Orthologous sequence alignment, phylogenetic tree analysis, and protein sequence analysis all showed that the cloned receptor belongs to the OA2B2 protein family. PxOA2B2 was transiently expressed in HEK-293 cells. It was found that PxOA2B2 could be activated by both octopamine and tyramine, resulting in increased intracellular cyclic AMP (cAMP) levels, whereas dopamine and serotonin were not effective in eliciting cAMP production. Further studies with series of PxOA2B2 agonists and antagonists showed that all four tested agonists (e.g., naphazoline, clonidine, 2-phenylethylamine, and amitraz) could activate the PxOA2B2 receptor, and two of tested antagonists (e.g., phentolamine and mianserin) had significant antagonistic effects. However, antagonist of yohimbine had no effects. Quantitative real-time polymerase chain reaction analysis showed that Pxoa2b2 gene was expressed in all developmental stages of P. xylostella and that the highest expression occurred in male adults. Further analysis with fourth-instar P. xylostella larvae showed that the Pxoa2b2 gene was mainly expressed in Malpighian tubule, epidermal, and head tissues. This study provides both a pharmacological characterization and the gene expression patterns of the OA2B2 in P. xylostella, facilitating further research for insecticides using PxOA2B2 as a target. © 2018 Wiley Periodicals, Inc.

Channel catfish (Ictalurus punctatus) leukocytes express estrogen receptor isoforms ERα and ERβ2 and are functionally modulated by estrogens.

PubMed

Iwanowicz, Luke R; Stafford, James L; Patiño, Reynaldo; Bengten, Eva; Miller, Norman W; Blazer, Vicki S

2014-09-01

Estrogens are recognized as modulators of immune responses in mammals and teleosts. While it is known that the effects of estrogens are mediated via leukocyte-specific estrogen receptors (ERs) in humans and mice, leucocyte-specific estrogen receptor expression and the effects of estrogens on this cell population is less explored and poorly understood in teleosts. Here in, we verify that channel catfish (Ictalurus punctaus) leukocytes express ERα and ERβ2. Transcripts of these isoforms were detected in tissue-associated leukocyte populations by PCR, but ERβ2 was rarely detected in PBLs. Expression of these receptors was temporally regulated in PBLs following polyclonal activation by concanavalin A, lipopolysaccharide or alloantigen based on evaluation by quantitative and end-point PCR. Examination of long-term leukocyte cell lines demonstrated that these receptors are differentially expressed depending on leukocyte lineage and phenotype. Expression of ERs was also temporally dynamic in some leukocyte lineages and may reflect stage of cell maturity. Estrogens affect the responsiveness of channel catfish peripheral blood leukocytes (PBLs) to mitogens in vitro. Similarly, bactericidal activity and phorbol 12-myristate 13-acetate induced respiratory burst was modulated by 17β-estradiol. These actions were blocked by the pure ER antagonist ICI 182780 indicating that response is, in part, mediated via ERα. In summary, estrogen receptors are expressed in channel catfish leukocytes and participate in the regulation of the immune response. This is the first time leukocyte lineage expression has been reported in teleost cell lines. Published by Elsevier Ltd.

Immunocytochemical assessment of sigma-1 receptor and human sterol isomerase in breast cancer and their relationship with a series of prognostic factors

PubMed Central

Simony-Lafontaine, J; Esslimani, M; Bribes, E; Gourgou, S; Lequeux, N; Lavail, R; Grenier, J; Kramar, A; Casellas, P

2000-01-01

The purpose of this study was to immunocytochemically investigate two new markers, the sigma-1 receptor and the human sterol isomerase (hSI), in comparison with a series of clinicopathological and immunocytochemical prognostic factors in a trial including 95 patients with operable primary breast cancers. Our results showed no statistically significant relationship between these two markers and the age of the patients, their menopausal status, the tumour size and its histological grade, the nodal status and the expression of the Ki-67 proliferative marker. However, we evidenced a close correlation between the sigma-1 receptor expression and the hormonal receptor positivity (P = 0.008), essentially due to a link with the progesterone receptor status (P = 0.01). By contrast there was an inverse relationship between hSI expression and the oestrogen receptor and/or progesterone receptor positivity (P = 0.098). A significant relationship was shown between both the sigma-1 receptor, hSI expressions and Bcl2 expression, with P = 0.017 and 0.035 respectively. We also assessed whether the expression of the sigma-1 receptor or hSI might be linked with disease-free survival (DFS) and found that the presence of hSI and the absence of sigma-1 receptor expression were associated with a poorer disease-free survival (P = 0.007). Altogether these results suggest that in primary breast carcinomas in association with the evaluation of the steroid receptor status, the sigma-1 receptor and hSI may be interesting new markers useful to identify those patients who might be able to benefit from an adjuvant therapy. © 2000 Cancer Research Campaign PMID:10864204

Valsartan attenuates intimal hyperplasia in balloon-injured rat aortic arteries through modulating the angiotensin-converting enzyme 2-angiotensin-(1-7)-Mas receptor axis.

PubMed

Li, Yonghong; Cai, Shanglang; Wang, Qixin; Zhou, Jingwei; Hou, Bo; Yu, Haichu; Ge, Zhiming; Guan, Renyan; Liu, Xu

2016-05-15

The role of the Mas receptor in the activity of valsartan against intimal hyperplasia is unclear. Herein, we investigated the role of the angiotensin-converting enzyme 2 (ACE2)-angiotensin-(1-7)-Mas receptor axis on the activity of valsartan against intimal hyperplasiain balloon-injured rat aortic arteries. Wistar rats were randomized equally into the sham control group, injured group, and injured plus valsartan (20 mg/kg/d)-treated group. Valsartan significantly attenuated the vascular smooth muscle cell proliferation and intimal and medial thickening on days 14 and 28 after injury. The angiotensin-(1-7) levels as well as ACE2 and Mas receptor mRNA/protein expression were significantly decreased in the injured rats, compared to the uninjured rats; meanwhile, the angiotensin II level as well as the ACE and AT1 receptor mRNA/protein expression were increased (all P < 0.05 or < 0.01). Additionally, the p-ERK protein expression was increased (P < 0.01). Treatment with valsartan significantly increased the angiotensin-(1-7) levels as well as ACE2 and Mas receptor mRNA/protein expression but decreased the angiotensin II level, ACE and AT1 receptor mRNA/protein expression, as well as the p-ERK protein expression, compared to the injured group (all P < 0.05 or < 0.01). These results suggest that valsartan attenuates neointimal hyperplasiain balloon-injured rat aortic arteries through activation of the ACE2-angiotensin-(1-7)-Mas axis as well as inhibition of the ACE-angiotensin II-AT1 and p-ERK pathways. Copyright © 2016 Elsevier Inc. All rights reserved.

Developmentally Regulated Expression of the Nerve Growth Factor Receptor Gene in the Periphery and Brain

NASA Astrophysics Data System (ADS)

Buck, C. R.; Martinez, Humberto J.; Black, Ira B.; Chao, Moses V.

1987-05-01

Nerve growth factor (NGF) regulates development and maintenance of function of peripheral sympathetic and sensory neurons. A potential role for the trophic factor in brain has been detected only recently. The ability of a cell to respond to NGF is due, in part, to expression of specific receptors on the cell surface. To study tissue-specific expression of the NGF receptor gene, we have used sensitive cRNA probes for detection of NGF receptor mRNA. Our studies indicate that the receptor gene is selectively and specifically expressed in sympathetic (superior cervical) and sensory (dorsal root) ganglia in the periphery, and by the septum-basal forebrain centrally, in the neonatal rat in vivo. Moreover, examination of tissues from neonatal and adult rats reveals a marked reduction in steady-state NGF receptor mRNA levels in sensory ganglia. In contrast, a 2- to 4-fold increase was observed in the basal forebrain and in the sympathetic ganglia over the same time period. Our observations suggest that NGF receptor mRNA expression is developmentally regulated in specific areas of the nervous system in a differential fashion.

Evidence for Gating Roles of Protein Kinase A and Protein Kinase C in Estradiol-Induced Luteinizing Hormone Receptor (lhcgr) Expression in Zebrafish Ovarian Follicle Cells

PubMed Central

Liu, Ka-Cheuk; Ge, Wei

2013-01-01

Estradiol (E2) stimulates luteinizing hormone receptor (lhcgr) expression in zebrafish follicle cells via nuclear estrogen receptors (nERs) that are likely expressed on the membrane, and lhcgr responds to E2 in a biphasic manner during 24-h treatment. These observations raise an interesting question on the signaling mechanism underlying E2 regulation, in particular the biphasic response of lhcgr expression. In the present study, we demonstrated that E2 regulation of lhcgr was significantly influenced by the activity of cAMP-PKA pathway. Activation of cAMP-PKA pathway by forskolin or db-cAMP suppressed E2-stimulated lhcgr expression in short-term (3 h) but enhanced its effect in long-term (24 h), suggesting differential roles of PKA at these two phases of lhcgr response. PKA inhibitor H89 showed reversed effects. In contrast, PKC pathway had consistent permissive effect on E2-induced lhcgr expression as evidenced by strong inhibition of E2 effect by PKC inhibitors GF109203X and Ro-31-8220 at both 3 and 24 h. One of the mechanisms by which PKA and PKC gated E2 effect might be through regulating nERs, particularly esr2a. Despite the strong influence of PKA and PKC, our data did not suggest direct mediating roles for these two pathways in E2 stimulation of lhcgr expression; yet they likely play critical gating roles in E2 signal transduction. As a follow-up study to our previous report on E2 regulation of gonadotropin receptors in the zebrafish ovary, the present study provides further evidence for the involvement of classical intracellular signal transduction pathways in E2 stimulation of lhcgr expression in the follicle cells. PMID:23658740

Functional properties of internalization-deficient P2X4 receptors reveal a novel mechanism of ligand-gated channel facilitation by ivermectin.

PubMed

Toulmé, Estelle; Soto, Florentina; Garret, Maurice; Boué-Grabot, Eric

2006-02-01

Although P2X receptors within the central nervous system mediate excitatory ATP synaptic transmission, the identity of central ATP-gated channels has not yet been elucidated. P2X(4), the most widely expressed subunit in the brain, was previously shown to undergo clathrin-dependent constitutive internalization by direct interaction between activator protein (AP)2 adaptors and a tyrosine-based sorting signal specifically present in the cytosolic C-terminal tail of mammalian P2X(4) sequences. In this study, we first used internalization-deficient P2X(4) receptor mutants to show that suppression of the endocytosis motif significantly increased the apparent sensitivity to ATP and the ionic permeability of P2X(4) channels. These unique properties, observed at low channel density, suggest that interactions with AP2 complexes may modulate the function of P2X(4) receptors. In addition, ivermectin, an allosteric modulator of several receptor channels, including mammalian P2X(4), did not potentiate the maximal current of internalization-deficient rat or human P2X(4) receptors. We demonstrated that binding of ivermectin onto wild-type P2X(4) channels increased the fraction of plasma membrane P2X(4) receptors, whereas surface expression of internalization-deficient P2X(4) receptors remained unchanged. Disruption of the clathrin-mediated endocytosis with the dominant-negative mutants Eps15 or AP-50 abolished the ivermectin potentiation of wild-type P2X(4) channel currents. Likewise, ivermectin increased the membrane fraction of nicotinic alpha7 acetylcholine (nalpha7ACh) receptors and the potentiation of acetylcholine current by ivermectin was suppressed when the same dominant-negative mutants were expressed. These data showed that potentiation by ivermectin of both P2X(4) and nalpha7ACh receptors was primarily caused by an increase in the number of cell surface receptors resulting from a mechanism dependent on clathrin/AP2-mediated endocytosis.

ACTIVATION OF MU OPIOID RECEPTORS IN THE STRIATUM DIFFERENTIALLY AUGMENTS METHAMPHETAMINE-INDUCED GENE EXPRESSION AND ENHANCES STEREOTYPIC BEHAVIOR

PubMed Central

Horner, Kristen A.; Hebbard, John C.; Logan, Anna S.; Vanchipurakel, Golda A.; Gilbert, Yamiece E.

2013-01-01

Mu opioid receptors are densely expressed in the patch compartment of striatum and contribute to methamphetamine-induced patch-enhanced gene expression and stereotypy. In order to further elucidate the role of mu opioid receptor activation in these phenomena, we examined whether activation of mu opioid receptors would enhance methamphetamine-induced stereotypy and prodynorphin, c-fos, arc and zif/268 expression in the patch and/or matrix compartments of striatum, as well as the impact of mu opioid receptor activation on the relationship between patch-enhanced gene expression and stereotypy. Male Sprague-Dawley rats were intrastriatally infused with D-Ala(2)-N-Me-Phe(4),Gly(5)-ol]enkephalin (DAMGO; 1 μg/μl), treated with methamphetamine (0.5 mg/kg) and sacrificed at 45 minutes or 2 hours later. DAMGO augmented methamphetamine-induced zif/268 mRNA expression in the patch and matrix compartments, while prodynorphin expression was increased in the dorsolateral patch compartment. DAMGO pretreatment did not affect methamphetamine-induced arc and c-fos expression. DAMGO enhanced methamphetamine-induced stereotypy and resulted in greater patch versus matrix expression of prodynorphin in the dorsolateral striatum, leading to a negative correlation between the two. These findings indicate that mu opioid receptors contribute to methamphetamine-induced stereotypy, but can differentially influence the genomic responses to methamphetamine. These data also suggest that prodynorphin may offset the overstimulation of striatal neurons by methamphetamine. PMID:22150526

Mechanism of H₂ histamine receptor dependent modulation of body temperature and neuronal activity in the medial preoptic nucleus.

PubMed

Tabarean, Iustin V; Sanchez-Alavez, Manuel; Sethi, Jasmine

2012-08-01

Histamine is involved in the central control of arousal, circadian rhythms and metabolism. The preoptic area, a region that contains thermoregulatory neurons is the main locus of histamine modulation of body temperature. Here we report that in mice, histamine activates H(2) subtype receptors in the medial preoptic nucleus (MPON) and induces hyperthermia. We also found that a population of glutamatergic MPON neurons express H(2) receptors and are excited by histamine or H(2) specific agonists. The agonists decreased the input resistance of the neuron and increased the depolarizing "sag" observed during hyperpolarizing current injections. Furthermore, at -60 mV holding potential, activation of H(2) receptors induced an inward current that was blocked by ZD7288, a specific blocker of the hyperpolarization activated cationic current (I(h)). Indeed, activation of H(2) receptors resulted in increased I(h) amplitude in response to hyperpolarizing voltage steps and a depolarizing shift in its voltage-dependent activation. The neurons excited by H(2) specific agonism expressed the HCN1 and HCN2 channel subunits. Our data indicate that at the level of the MPON histamine influences thermoregulation by increasing the firing rate of glutamatergic neurons that express H(2) receptors. Copyright © 2012 Elsevier Ltd. All rights reserved.

Early continuous white noise exposure alters l-alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor subunit glutamate receptor 2 and gamma-aminobutyric acid type a receptor subunit beta3 protein expression in rat auditory cortex.

PubMed

Xu, Jinghong; Yu, Liping; Zhang, Jiping; Cai, Rui; Sun, Xinde

2010-02-15

Auditory experience during the postnatal critical period is essential for the normal maturation of auditory function. Previous studies have shown that rearing infant rat pups under conditions of continuous moderate-level noise delayed the emergence of adult-like topographic representational order and the refinement of response selectivity in the primary auditory cortex (A1) beyond normal developmental benchmarks and indefinitely blocked the closure of a brief, critical-period window. To gain insight into the molecular mechanisms of these physiological changes after noise rearing, we studied expression of the AMPA receptor subunit GluR2 and GABA(A) receptor subunit beta3 in the auditory cortex after noise rearing. Our results show that continuous moderate-level noise rearing during the early stages of development decreases the expression levels of GluR2 and GABA(A)beta3. Furthermore, noise rearing also induced a significant decrease in the level of GABA(A) receptors relative to AMPA receptors. However, in adult rats, noise rearing did not have significant effects on GluR2 and GABA(A)beta3 expression or the ratio between the two units. These changes could have a role in the cellular mechanisms involved in the delayed maturation of auditory receptive field structure and topographic organization of A1 after noise rearing. Copyright 2009 Wiley-Liss, Inc.

Expression of Hormone Receptors and HER-2 in Benign and Malignant Salivary Gland Tumors.

PubMed

Can, Nhu Thuy; Lingen, Mark W; Mashek, Heather; McElherne, James; Briese, Renee; Fitzpatrick, Carrie; van Zante, Annemieke; Cipriani, Nicole A

2018-03-01

With the advent of targeted therapies, expression of sex hormone receptors and HER-2 in salivary gland tumors (SGTs) is of clinical interest. Previous reports of estrogen (ER) and progesterone (PR) receptor expression have varied. Androgen receptor (AR) and HER-2 overexpression are frequently reported in salivary duct carcinoma (SDC), but have not been studied systematically in other SGTs. This study examines ER, PR, AR, and HER-2 expression in SGTs. Immunohistochemistry for ER, PR, AR, and HER-2 was performed on 254 SGTs (134 malignant). ER, PR, and AR expression was scored using Allred system. HER-2 expression was scored using Dako HercepTest guidelines. FISH for HER-2 amplification was performed on select cases with HER-2 overexpression (2-3+). No SGT demonstrated strong expression of ER or PR. Combined strong AR and HER-2 expression was seen in 22 carcinomas: 14/25 SDC, 3/16 poorly differentiated, two oncocytic, and one each carcinoma ex pleomorphic adenoma, squamous cell, and intraductal carcinoma. Eighteen additional high grade carcinomas had HER-2 overexpression with absent, weak, or moderate AR expression; eight high grade carcinomas had isolated strong AR expression with 0-1+ HER-2 staining. Of 15 tested cases, six demonstrated HER-2 amplification by FISH, all of which had 3+ immunoreactivity. Neither benign nor malignant SGTs had strong expression of ER or PR. None of the benign SGTs overexpressed AR or HER-2. Coexpression of AR and HER-2 should not define SDC, but immunostaining should be considered in high grade salivary carcinomas, as some show overexpression and may benefit from targeted therapy.

Adolescent social defeat increases adult amphetamine conditioned place preference and alters D2 dopamine receptor expression

PubMed Central

Burke, Andrew R.; Watt, Michael J.; Forster, Gina L.

2011-01-01

Components of the brain’s dopaminergic system, such as dopamine receptors, undergo final maturation in adolescence. Exposure to social stress during human adolescence contributes to substance abuse behaviors. We utilized a rat model of adolescent social stress to investigate the neural mechanisms underlying this correlation. Rats exposed to repeated social defeat in adolescence (P35–P39) exhibited increased conditioned place preference (CPP) for amphetamine (1 mg/kg) in adulthood (P70). In contrast, rats experiencing foot-shock during the same developmental period exhibited amphetamine CPP levels similar to non-stressed controls. Our previous experiments suggested adolescent defeat alters dopamine activity in the mesocorticolimbic system. Furthermore, dopamine receptors have been implicated in the expression of amphetamine CPP. Therefore, we hypothesized that alteration to dopamine receptor expression in the mesocorticolimbic system may be associated with to heightened amphetamine CPP of adult rats exposed to adolescence defeat. We measured D1 and D2 dopamine receptor protein content in the medial prefrontal cortex, nucleus accumbens (NAc) and dorsal striatum following either adolescent social defeat or foot-shock stress and then adult amphetamine CPP. In controls, amphetamine CPP training reduced D2 receptor protein content in the NAc core. However, this down-regulation of NAc core D2 receptors was blocked by exposure to social defeat but not foot-shock stress in adolescence. These results suggest social defeat stress in adolescence alters the manner in which later amphetamine exposure down-regulates D2 receptors. Furthermore, persistent alterations to adult D2 receptor expression and amphetamine responses may depend on the type of stress experienced in adolescence. PMID:21933700

Regulation of Oligomeric Organization of the Serotonin 5-Hydroxytryptamine 2C (5-HT2C) Receptor Observed by Spatial Intensity Distribution Analysis*

PubMed Central

Ward, Richard J.; Pediani, John D.; Godin, Antoine G.; Milligan, Graeme

2015-01-01

The questions of whether G protein-coupled receptors exist as monomers, dimers, and/or oligomers and if these species interconvert in a ligand-dependent manner are among the most contentious current issues in biology. When employing spatial intensity distribution analysis to laser scanning confocal microscope images of cells stably expressing either a plasma membrane-associated form of monomeric enhanced green fluorescent protein (eGFP) or a tandem version of this fluorophore, the eGFP tandem was identified as a dimer. Similar studies on cells stably expressing an eGFP-tagged form of the epidermal growth factor receptor demonstrated that, although largely a monomer in the basal state, this receptor rapidly became predominantly dimeric upon the addition of its ligand epidermal growth factor. In cells induced to express an eGFP-tagged form of the serotonin 5-hydroxytryptamine 2C (5-HT2C) receptor, global analysis of construct quantal brightness was consistent with the predominant form of the receptor being dimeric. However, detailed spatial intensity distribution analysis demonstrated the presence of multiple forms ranging from monomers to higher-order oligomers. Furthermore, treatment with chemically distinct 5-HT2C receptor antagonists resulted in a time-dependent change in the quaternary organization to one in which there was a preponderance of receptor monomers. This antagonist-mediated effect was reversible, because washout of the ligand resulted in the regeneration of many of the oligomeric forms of the receptor. PMID:25825490

Cysteinyl Leukotriene 1 Receptor Expression Associated With Bronchial Inflammation in Severe Exacerbations of COPD

PubMed Central

Zhu, Jie; Bandi, Venkata; Qiu, Shengyang; Figueroa, David J.; Evans, Jilly F.; Barnes, Neil; Guntupalli, Kay K.

2012-01-01

Background: Cysteinyl leukotriene 1 (CysLT1) receptor expression is known to be increased in the airway mucosa of patients with asthma, especially during exacerbations; however, nothing is known of its expression in COPD. Methods: We applied immunohistochemistry and in situ hybridization to endobronchial biopsies to determine inflammatory cell CysLT1 receptor protein and mRNA expression in the following: (1) 15 nonsmoker control subjects (NSC), (2) 16 smokers with moderate to severe COPD in its stable phase (S-COPD), and (3) 15 smokers with COPD hospitalized for a severe exacerbation (SE-COPD). Results: The total number of bronchial mucosal inflammatory cells (CD45+) and those expressing CysLT1 receptor protein were significantly greater in SE-COPD (CysLT1 receptor protein: median [range] = 139 [31-634]) as compared with S-COPD (32 [6-114]) or NSC (16 [4-66]) (P < .001 for both). CysLT1 receptor gene expression showed similar differences. A greater proportion of CD451 cells expressed CysLT1 receptor protein in SE-COPD (median [range] = 22% [8-81]) compared with S-COPD (10% [4-32]) (P < .03) or NSC (7% [1-19]) (P < .002). In SE-COPD, the relative frequencies of CysLT1 receptor-expressing cells were as follows: tryptase1 mast cells > CD681 monocytes/macrophage > neutrophils > CD201 B lymphocytes = EG21 eosinophils. Moreover, there were positive correlations between the numbers of cells expressing CysLT1 receptor protein and the numbers of CD451 cells (r = 0.78; P < .003) and tryptase1 mast cells (r = 0.62; P < .02). Conclusions: Bronchial mucosal CysLT1 receptor-positive inflammatory cells are present in the bronchial mucosa in COPD in greatest number in those experiencing a severe exacerbation. PMID:22871757

Regulation of ERRα Gene Expression by Estrogen Receptor Agonists and Antagonists in SKBR3 Breast Cancer Cells: Differential Molecular Mechanisms Mediated by G Protein-Coupled Receptor GPR30/GPER-1

PubMed Central

Li, Yin; Birnbaumer, Lutz; Teng, Christina T.

2010-01-01

In selected tissues and cell lines, 17β-estradiol (E2) regulates the expression of estrogen-related receptor α (ERRα), a member of the orphan nuclear receptor family. This effect is thought to be mediated by the estrogen receptor α (ERα). However in the ERα- and ERβ-negative SKBR3 breast cancer cell line, physiological levels of E2 also stimulate ERRα expression. Here, we explored the molecular mechanism that mediates estrogen action in ER-negative breast cancer cells. We observed that E2, the ERα agonist, as well as the ERα antagonists ICI 182,780 and tamoxifen (TAM), a selective ER modulator, stimulate the transcriptional activity of the ERRα gene and increase the production of ERRα protein in SKBR3 cells. Moreover, the ERRα downstream target genes expression and cellular proliferation are also increased. We show further that the G protein-coupled receptor GPR30/GPER-1 (GPER-1) mediates these effects. The GPER-1 specific ligand G-1 mimics the actions of E2, ICI 182,780, and TAM on ERRα expression, and changing the levels of GPER-1 mRNA by overexpression or small interfering RNA knockdown affected the expression of ERRα accordingly. Utilizing inhibitors, we delineate a different downstream pathway for ER agonist and ER antagonist-triggered signaling through GPER-1. We also find differential histone acetylation and transcription factor recruitment at distinct nucleosomes of the ERRα promoter, depending on whether the cells are activated with E2 or with ER antagonists. These findings provide insight into the molecular mechanisms of GPER-1/ERRα-mediated signaling and may be relevant to what happens in breast cancer cells escaping inhibitory control by TAM. PMID:20211987

Expression of feeding-related peptide receptors mRNA in GT1-7 cell line and roles of leptin and orexins in control of GnRH secretion.

PubMed

Yang, Ying; Zhou, Li-bin; Liu, Shang-quan; Tang, Jing-feng; Li, Feng-yin; Li, Rong-ying; Song, Huai-dong; Chen, Ming-dao

2005-08-01

To investigate the expression of feeding-related peptide receptors mRNA in GT1-7 cell line and roles of leptin and orexins in the control of GnRH secretion. Receptors of bombesin3, cholecystokinin (CCK)-A, CCK-B, glucagon-like peptide (GLP)1, melanin-concentrating hormone (MCH)1, orexin1, orexin2, neuromedin-B, neuropeptide Y (NPY)1 and NPY5, neurotensin (NT)1, NT2, NT3, and leptin receptor long form mRNA in GT1-7 cells were detected by reversed transcriptase-polymerase chain reaction. GT1-7 cells were treated with leptin, orexin A and orexin B at a cohort of concentrations for different lengths of time, and GnRH in medium was determined by radioimmunoassay (RIA). Receptors of bombesin 3, CCK-B, GLP1, MCH1, orexin1, neuromedin-B, NPY1, NPY5, NT1, NT3, and leptin receptor long form mRNA were expressed in GT1-7 cells, of which, receptors of GLP1, neuromedin-B, NPY1, and NT3 were highly expressed. No amplified fragments of orexin2, NT2, and CCK-A receptor cDNA were generated with GT1-7 RNA, indicating that the GT1-7 cells did not express mRNA of them. Leptin induced a significant stimulation of GnRH release, the results being most significant at 0.1 nmol/L for 15 min. In contrast to other studies in hypothalamic explants, neither orexin A nor orexin B affected basal GnRH secretion over a wide range of concentrations ranging from 1 nmol/L to 500 nmol/Lat 15, 30, and 60 min. Feeding and reproductive function are closely linked. Many orexigenic and anorexigenic signals may control feeding behavior as well as alter GnRH secretion through their receptors on GnRH neurons.

HIV-1 TAT protein enhances sensitization to methamphetamine by affecting dopaminergic function.

PubMed

Kesby, James P; Najera, Julia A; Romoli, Benedetto; Fang, Yiding; Basova, Liana; Birmingham, Amanda; Marcondes, Maria Cecilia G; Dulcis, Davide; Semenova, Svetlana

2017-10-01

Methamphetamine abuse is common among humans with immunodeficiency virus (HIV). The HIV-1 regulatory protein TAT induces dysfunction of mesolimbic dopaminergic systems which may result in impaired reward processes and contribute to methamphetamine abuse. These studies investigated the impact of TAT expression on methamphetamine-induced locomotor sensitization, underlying changes in dopamine function and adenosine receptors in mesolimbic brain areas and neuroinflammation (microgliosis). Transgenic mice with doxycycline-induced TAT protein expression in the brain were tested for locomotor activity in response to repeated methamphetamine injections and methamphetamine challenge after a 7-day abstinence period. Dopamine function in the nucleus accumbens (Acb) was determined using high performance liquid chromatography. Expression of dopamine and/or adenosine A receptors (ADORA) in the Acb and caudate putamen (CPu) was assessed using RT-PCR and immunohistochemistry analyses. Microarrays with pathway analyses assessed dopamine and adenosine signaling in the CPu. Activity-dependent neurotransmitter switching of a reserve pool of non-dopaminergic neurons to a dopaminergic phenotype in the ventral tegmental area (VTA) was determined by immunohistochemistry and quantified with stereology. TAT expression enhanced methamphetamine-induced sensitization. TAT expression alone decreased striatal dopamine (D1, D2, D4, D5) and ADORA1A receptor expression, while increasing ADORA2A receptors expression. Moreover, TAT expression combined with methamphetamine exposure was associated with increased adenosine A receptors (ADORA1A) expression and increased recruitment of dopamine neurons in the VTA. TAT expression and methamphetamine exposure induced microglia activation with the largest effect after combined exposure. Our findings suggest that dopamine-adenosine receptor interactions and reserve pool neuronal recruitment may represent potential targets to develop new treatments for methamphetamine abuse in individuals with HIV. Copyright © 2017 Elsevier Inc. All rights reserved.

Memory in aged mice is rescued by enhanced expression of the GluN2B subunit of the NMDA receptor

PubMed Central

Brim, B. L.; Haskell, R.; Awedikian, R.; Ellinwood, N.M.; Jin, L.; Kumar, A.; Foster, T.C.; Magnusson, K.

2012-01-01

The GluN2B subunit of the N-methyl-D-aspartate (NMDA) receptor shows age-related declines in expression across the frontal cortex and hippocampus. This decline is strongly correlated to age-related memory declines. This study was designed to determine if increasing GluN2B subunit expression in the frontal lobe or hippocampus would improve memory in aged mice. Mice were injected bilaterally with either the GluN2B vector, containing cDNA specific for the GluN2B subunit and enhanced Green Fluorescent Protein (eGFP); a control vector or vehicle. Spatial memory, cognitive flexibility, and associative memory were assessed using the Morris water maze. Aged mice, with increased GluN2B subunit expression, exhibited improved long-term spatial memory, comparable to young mice. However, memory was rescued on different days in the Morris water maze; early for hippocampal GluN2B subunit enrichment and later for the frontal lobe. A higher concentration of the GluN2B antagonist, Ro 25-6981, was required to impair long-term spatial memory in aged mice with enhanced GluN2B expression, as compared to aged controls, suggesting there was an increase in the number of GluN2B-containing NMDA receptors. In addition, hippocampal slices from aged mice with increased GluN2B subunit expression exhibited enhanced NMDA receptor-mediated excitatory post-synaptic potentials (EPSP). Treatment with Ro 25-6981 showed that a greater proportion of the NMDA receptor-mediated EPSP was due to the GluN2B subunit in these animals, as compared to aged controls. These results suggest that increasing the production of the GluN2B subunit in aged animals enhances memory and synaptic transmission. Therapies that enhance GluN2B subunit expression within the aged brain may be useful for ameliorating age-related memory declines. PMID:23103326

The role of transient receptor potential vanilloid type-2 ion channels in innate and adaptive immune responses

PubMed Central

Santoni, Giorgio; Farfariello, Valerio; Liberati, Sonia; Morelli, Maria B.; Nabissi, Massimo; Santoni, Matteo; Amantini, Consuelo

2013-01-01

The transient receptor potential vanilloid type-2 (TRPV2), belonging to the transient receptor potential channel family, is a specialized ion channel expressed in human and other mammalian immune cells. This channel has been found to be expressed in CD34+ hematopoietic stem cells, where its cytosolic Ca2+ activity is crucial for stem/progenitor cell cycle progression, growth, and differentiation. In innate immune cells, TRPV2 is expressed in granulocytes, macrophages, and monocytes where it stimulates fMet-Leu-Phe migration, zymosan-, immunoglobulin G-, and complement-mediated phagocytosis, and lipopolysaccharide-induced tumor necrosis factor-alpha and interleukin-6 production. In mast cells, activation of TRPV2 allows intracellular Ca2+ ions flux, thus stimulating protein kinase A-dependent degranulation. In addition, TRPV2 is highly expressed in CD56+ natural killer cells. TRPV2 orchestrates Ca2+ signal in T cell activation, proliferation, and effector functions. Moreover, messenger RNA for TRPV2 are expressed in CD4+ and CD8+ T lymphocytes. Finally, TRPV2 is expressed in CD19+ B lymphocytes where it regulates Ca2+ release during B cell development and activation. Overall, the specific expression of TRPV2 in immune cells suggests a role in immune-mediated diseases and offers new potential targets for immunomodulation. PMID:23420671

Differential expression of pancreatic protein and chemosensing receptor mRNAs in NKCC1-null intestine.

PubMed

Bradford, Emily M; Vairamani, Kanimozhi; Shull, Gary E

2016-02-15

To investigate the intestinal functions of the NKCC1 Na(+)-K(+)-2Cl cotransporter (SLC12a2 gene), differential mRNA expression changes in NKCC1-null intestine were analyzed. Microarray analysis of mRNA from intestines of adult wild-type mice and gene-targeted NKCC1-null mice (n = 6 of each genotype) was performed to identify patterns of differential gene expression changes. Differential expression patterns were further examined by Gene Ontology analysis using the online Gorilla program, and expression changes of selected genes were verified using northern blot analysis and quantitative real time-polymerase chain reaction. Histological staining and immunofluorescence were performed to identify cell types in which upregulated pancreatic digestive enzymes were expressed. Genes typically associated with pancreatic function were upregulated. These included lipase, amylase, elastase, and serine proteases indicative of pancreatic exocrine function, as well as insulin and regenerating islet genes, representative of endocrine function. Northern blot analysis and immunohistochemistry showed that differential expression of exocrine pancreas mRNAs was specific to the duodenum and localized to a subset of goblet cells. In addition, a major pattern of changes involving differential expression of olfactory receptors that function in chemical sensing, as well as other chemosensing G-protein coupled receptors, was observed. These changes in chemosensory receptor expression may be related to the failure of intestinal function and dependency on parenteral nutrition observed in humans with SLC12a2 mutations. The results suggest that loss of NKCC1 affects not only secretion, but also goblet cell function and chemosensing of intestinal contents via G-protein coupled chemosensory receptors.

The effect of very-low-calorie diet on mRNA expression of inflammation-related genes in subcutaneous adipose tissue and peripheral monocytes of obese patients with type 2 diabetes mellitus.

PubMed

Mraz, M; Lacinova, Z; Drapalova, J; Haluzikova, D; Horinek, A; Matoulek, M; Trachta, P; Kavalkova, P; Svacina, S; Haluzik, M

2011-04-01

Low-grade inflammation links obesity, type 2 diabetes mellitus (T2DM), and cardiovascular diseases. To explore the expression profile of genes involved in inflammatory pathways in adipose tissue and peripheral monocytes (PM) of obese patients with and without T2DM at baseline and after dietary intervention. Two-week intervention study with very-low-calorie diet (VLCD). University hospital. Twelve obese females with T2DM, 8 obese nondiabetic females (OB) and 15 healthy age-matched females. Two weeks of VLCD (2500 kJ/d). Metabolic parameters, circulating cytokines, hormones, and mRNA expression of 39 genes in sc adipose tissue (SCAT) and PM. Both T2DM and OB group had significantly increased serum concentrations of circulating proinflammatory factors (C-reactive protein, TNFα, IL-6, IL-8), mRNA expression of macrophage antigen CD68 and proinflammatory chemokines (CCL-2, -3, -7, -8, -17, -22) in SCAT and complementary chemokine receptors (CCR-1, -2, -3, -5) and other proinflammatory receptors (toll-like receptor 2 and 4, TNF receptor superfamily 1A and 1B, IL-6R) in PM, with OB group showing less pronounced chemoattracting and proinflammatory profile compared to T2DM group. In T2DM patients VLCD decreased body weight, improved metabolic profile, and decreased mRNA expression of up-regulated CCRs in PM and chemokines [CCL 8, chemokine (C-X-C motif) ligand 10] in SCAT. VLCD markedly increased mRNA expression of T-lymphocyte attracting chemokine CCL-17 in SCAT. Obese patients with and without T2DM have increased mRNA expression of chemotactic and proinflammatory factors in SCAT and expression of corresponding receptors in PM. Two weeks of VLCD significantly improved this profile in T2DM patients.

Inflammation Stimulates the Expression of PCSK9

PubMed Central

Feingold, Kenneth R.; Moser, Arthur H.; Shigenaga, Judy K.; Patzek, Sophie M.; Grunfeld, Carl

2008-01-01

Inflammation induces marked changes in lipid and lipoprotein metabolism. Proprotein convertase subtilisin kexin 9 (PCSK9) plays an important role in regulating LDL receptor degradation. Here we demonstrate that LPS decreases hepatic LDL receptor protein but at the same time hepatic LDL receptor mRNA levels are not decreased. We therefore explored the effect of LPS on PCSK9 expression. LPS results in a marked increase in hepatic PCSK9 mRNA levels (4 hours-2.5 fold increase; 38 hours-12.5 fold increase). The increase in PCSK9 is a sensitive response with 1 ug LPS inducing a ½ maximal response. LPS also increased PCSK9 expression in the kidney. Finally, zymosan and turpentine, other treatments that induce inflammation, also stimulated hepatic expression of PCSK9. Thus, inflammation stimulates PCSK9 expression leading to increased LDL receptor degradation and decreasing LDL receptors thereby increasing serum LDL, which could have beneficial effects on host defense. PMID:18638454

Tumor necrosis factor-α inhibits angiotensin II receptor type 1 expression in dorsal root ganglion neurons via β-catenin signaling.

PubMed

Yang, Y; Wu, H; Yan, J-Q; Song, Z-B; Guo, Q-L

2013-09-17

Both tumor necrosis factor (TNF)-α and the angiotensin (Ang) II/angiotensin II receptor type 1 (AT1) axis play important roles in neuropathic pain and nociception. In the present study, we explored the interaction between the two systems by examining the mutual effects between TNF-α and the Ang II/AT1 receptor axis in dorsal root ganglion (DRG) neurons. Rat DRG neurons were treated with TNF-α in different concentrations for different lengths of time in the presence or absence of transcription inhibitor actinomycin D, TNF receptor 1 (TNFR1) inhibitor SPD304, β-catenin signaling inhibitor CCT031374, or different kinase inhibitors. TNF-α decreased the AT1 receptor mRNA level as well as the AT1a receptor promoter activity in a dose-dependent manner within 30 h, which led to dose-dependent inhibition of Ang II-binding AT1 receptor level on the cell membrane. Actinomycin D (1 mg/ml), SPD304 (50 μM), p38 mitogen-activated protein kinase (MAPK) inhibitor PD169316 (25 μM), and CCT031374 (50 μM) completely abolished the inhibitory effect of TNF-α on AT1 receptor expression. TNF-α dose-dependently increased soluble β-catenin and phosphorylated GSK-3β levels, which was blocked by SPD304 and PD169316. In DRG neurons treated with AT2 receptor agonist CGP421140, or Ang II with or without AT1 receptor antagonist losartan or AT2 receptor antagonist PD123319 for 30 h, we found that Ang II and Ang II+PD123319 significantly decreased TNF-α expression, whereas CPG421140 and Ang II+losartan increased TNF-α expression. In conclusion, we demonstrate that TNF-α inhibits AT1 receptor expression at the transcription level via TNFR1 in rat DRG neurons by increasing the soluble β-catenin level through the p38 MAPK/GSK-3β pathway. In addition, Ang II appears to inhibit and induce TNF-α expression via the AT1 receptor and the AT2 receptor in DRG neurons, respectively. This is the first evidence of crosstalk between TNF-α and the Ang II/AT receptor axis in DRG neurons. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

Organotropism and prognostic marker discordance in distant metastases of breast carcinoma: fact or fiction? A clinicopathologic analysis.

PubMed

St Romain, Paul; Madan, Rashna; Tawfik, Ossama W; Damjanov, Ivan; Fan, Fang

2012-03-01

Prior studies have suggested that the type of breast cancer influences the location of distant metastases ("organotropism") and that there may be discordance of estrogen receptor and human epidermal growth factor receptor 2 (Her2) expression between primaries and metastases. Our aims were to investigate the relationship between tumor type and metastatic site and to compare biomarker expression between primary and metastatic tumors. We retrospectively reviewed 102 biopsy-proven cases of breast cancer metastatic to distant sites from 2000 to 2010 and 34 corresponding primaries for histologic subtype, grade, lymphovascular invasion, lymph node metastasis, and expression of estrogen receptor and Her2. Most metastases were of ductal (88) and lobular (11) histologic types. Available data on primaries indicated that the majority were grade III with positive lymph node metastasis and lymphovascular invasion. Biomarkers on 73 metastases showed 37 estrogen receptor positive/Her2-, 6 estrogen receptor positive/Her2+, 8 estrogen receptor negative/Her2+, and 22 estrogen receptor negative/Her2-. The most common metastatic sites were the lung (26%), bone (32%), and liver (21%). We found no association between estrogen receptor/Her2 profile and metastatic site (P = .16). When compared with ductal carcinoma, lobular carcinoma showed a unique metastatic pattern to gastrointestinal tract/gynecologic sites (P = .014). Of 34 cases with paired prognostic markers for primary and metastatic sites, 7 (20%) demonstrated discordance in estrogen receptor-positive/Her2 profile between the primary and the metastasis. Because the estrogen receptor-positive/Her2 profile of metastatic breast cancer did not always match that of the primary tumor, it is important to repeat the prognostic markers of metastasis. Copyright © 2012 Elsevier Inc. All rights reserved.

Angiotensin (1-7) ameliorates the structural and biochemical alterations of ovariectomy-induced osteoporosis in rats via activation of ACE-2/Mas receptor axis.

PubMed

Abuohashish, Hatem M; Ahmed, Mohammed M; Sabry, Dina; Khattab, Mahmoud M; Al-Rejaie, Salim S

2017-05-23

The local and systemic renin angiotensin system (RAS) influences the skeletal system micro-structure and metabolism. Studies suggested angiotensin 1-7 (Ang(1-7)) as the beneficial RAS molecule via Mas receptor activation. This study examines the function of Ang(1-7) in bone micro-architecture and metabolism in an ovariectomized (OVX) rodent model of osteoporosis. OVX rats showed structural and bone metabolic degeneration in parallel with suppressed expressions of the angiotensin converting enzyme-2 (ACE-2)/Ang(1-7)/Mas components. The infusion of Ang(1-7) markedly alleviated the altered bone metabolism and significantly enhanced both trabecular (metaphyseal) and cortical (metaphyseal-diaphyseal) morphometry. Urinary and bones minerals were also improved in OVX rats by Ang(1-7). The infusion of the heptapeptide enhanced ACE-2/Mas receptor expressions, while down-regulated AngII, ACE, and AngII type-1 receptor (AT1R) in OVX animals. Moreover, Ang(1-7) markedly improved osteoprotegerin (OPG) and lowered receptor activator NF-κB ligand (RANKL) expressions. The defensive properties of Ang(1-7) on bone metabolism, structure and minerals were considerably eradicated after blockage of Mas receptor with A-779. Ang(1-7)-induced up-regulated ACE-2/Ang(1-7)/Mas cascade and OPG expressions were abolished and the expressions of ACE/AngII/AT1R and RANKL were provoked by A-779. These findings shows for the first time the novel valuable therapeutic role of Ang(1-7) on bone health and metabolism through the ACE-2/Mas cascade.

Cloning of human cDNA encoding a novel heptahelix receptor expressed in Burkitt's lymphoma and widely distributed in brain and peripheral tissues.

PubMed

Owman, C; Blay, P; Nilsson, C; Lolait, S J

1996-11-12

Using PCR with degenerate primers and screening of a human B-cell lymphoblast cDNA library, a full-length cDNA encoding a 375-amino-acid protein was isolated. It contains seven regions of hydrophobic amino acids probably representing membrane-spanning domains of a novel heptahelix receptor, tentatively named CMKRL2. It shows nearly 30% overall identity with the high-affinity IL8 receptor and similar degree of homology with other chemoattractant receptors, including the "fusin" coreceptors for HIV1. Measurements of various transduction pathways following application of a panel of chemokines to transfected cells failed to evoke any reproducible response. Although the natural ligand for CMKRL2 could, thus, not be identified, receptor expression in spleen and lymph nodes as well as in Burkitt's lymphoma (irrespective of EBV status) supports a functional role in activated B-cells. Receptor message was ubiquitously distributed in normal peripheral tissues and CNS, suggesting that CMKRL2 is expressed in widespread cell populations, such as macrophages and neuroglia.

Cholinergic chemosensory cells of the thymic medulla express the bitter receptor Tas2r131.

PubMed

Soultanova, Aichurek; Voigt, Anja; Chubanov, Vladimir; Gudermann, Thomas; Meyerhof, Wolfgang; Boehm, Ulrich; Kummer, Wolfgang

2015-11-01

The thymus is the site of T cell maturation which includes positive selection in the cortex and negative selection in the medulla. Acetylcholine is locally produced in the thymus and cholinergic signaling influences the T cell development. We recently described a distinct subset of medullary epithelial cells in the murine thymus which express the acetylcholine-synthesizing enzyme choline acetyltransferase (ChAT) and components of the canonical taste transduction cascade, i.e. transient receptor potential melastatin-like subtype 5 channel (TRPM5), phospholipase Cβ(2), and Gα-gustducin. Such a chemical phenotype is characteristic for chemosensory cells of mucosal surfaces which utilize bitter receptors for detection of potentially hazardous compounds and cholinergic signaling to initiate avoidance reflexes. We here demonstrate mRNA expression of bitter receptors Tas2r105, Tas2r108, and Tas2r131 in the murine thymus. Using a Tas2r131-tauGFP reporter mouse we localized the expression of this receptor to cholinergic cells expressing the downstream elements of the taste transduction pathway. These cells are distinct from the medullary thymic epithelial cells which promiscuously express tissue-restricted self-antigens during the process of negative selection, since double-labeling immunofluorescence showed no colocalization of autoimmune regulator (AIRE), the key mediator of negative selection, and TRPM5. These data demonstrate the presence of bitter taste-sensing signaling in cholinergic epithelial cells in the thymic medulla and opens a discussion as to what is the physiological role of this pathway. Copyright © 2015 Elsevier B.V. All rights reserved.

Keratin 17 is overexpressed and predicts poor survival in estrogen receptor-negative/human epidermal growth factor receptor-2-negative breast cancer.

PubMed

Merkin, Ross D; Vanner, Elizabeth A; Romeiser, Jamie L; Shroyer, A Laurie W; Escobar-Hoyos, Luisa F; Li, Jinyu; Powers, Robert S; Burke, Stephanie; Shroyer, Kenneth R

2017-04-01

Clinicopathological features of breast cancer have limited accuracy to predict survival. By immunohistochemistry (IHC), keratin 17 (K17) expression has been correlated with triple-negative status (estrogen receptor [ER]/progesterone receptor/human epidermal growth factor receptor-2 [HER2] negative) and decreased survival, but K17 messenger RNA (mRNA) expression has not been evaluated in breast cancer. K17 is a potential prognostic cancer biomarker, targeting p27, and driving cell cycle progression. This study compared K17 protein and mRNA expression to ER/progesterone receptor/HER2 receptor status and event-free survival. K17 IHC was performed on 164 invasive breast cancers and K17 mRNA was evaluated in 1097 breast cancers. The mRNA status of other keratins (16/14/9) was evaluated in 113 ER - /HER2 - ductal carcinomas. IHC demonstrated intense cytoplasmic and membranous K17 localization in myoepithelial cells of benign ducts and lobules and tumor cells of ductal carcinoma in situ. In ductal carcinomas, K17 protein was detected in most triple-negative tumors (28/34, 82%), some non-triple-negative tumors (52/112, 46%), but never in lobular carcinomas (0/15). In ductal carcinomas, high K17 mRNA was associated with reduced 5-year event-free survival in advanced tumor stage (n = 149, hazard ratio [HR] = 3.68, P = .018), and large (n = 73, HR = 3.95, P = .047), triple-negative (n = 103, HR = 2.73, P = .073), and ER - /HER2 - (n = 113, HR = 2.99, P = .049) tumors. There were significant correlations among keratins 17, 16, 14, and 9 mRNA levels suggesting these keratins (all encoded on chromosome 17) could be coordinately expressed in breast cancer. Thus, K17 is expressed in a subset of triple-negative breast cancers, and is a marker of poor prognosis in patients with advanced stage and ER - /HER2 - breast cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

Identification of a second murine interleukin-11 receptor alpha-chain gene (IL11Ra2) with a restricted pattern of expression.

PubMed

Robb, L; Hilton, D J; Brook-Carter, P T; Begley, C G

1997-03-15

The interleukin-11 receptor alpha-chain, a member of the hematopoietin receptor superfamily, forms, together with gp130, a functional high-affinity receptor complex for interleukin 11. We, and others, reported the cloning of the murine interleukin 11 receptor alpha-chain cDNA (IL11Ra) and recently described the structure of the IL11Ra locus. We also described the presence of a second IL11Ra-like locus in some mouse strains. In this study we report that the second locus, designated IL11Ra2, encodes an mRNA species. The transcript was 99% identical to the IL11Ra transcript in the coding and 3'-untranslated region, but had a different 5'-untranslated region. The complete genomic organization of the IL11Ra2 locus is presented, and the two loci are shown to be located on a 200-kb NaeI genomic fragment. Comparison of the expression pattern of the IL11Ra and IL11Ra2 genes using an RT-PCR restriction fragment length polymorphism strategy revealed that while the expression of IL11Ra was widespread, expression of IL11Ra2 was restricted to testis, lymph node, and thymus.

Cytochemical Organization of the Retino-Suprachiasmatic System

DTIC Science & Technology

1994-03-11

strongly expiessed of the, non-NMDA ionotropic receptors . Other AMPA-preferring receptors , GluR3 and -R4, were also found, but to lesser extent...kainate, and NMDA receptor RN was found in the hypothalamus. GluRi and GluR2 were ang the nmst strongly expressed of the non-NvDA ionotropic receptors ...several different glutamate receptors . The expression of many different types of ionotropic glutamate receptors throughout the hypothalamus suggests that

The V1a and V1b, but not V2, vasopressin receptor genes are expressed in the supraoptic nucleus of the rat hypothalamus, and the transcripts are essentially colocalized in the vasopressinergic magnocellular neurons.

PubMed

Hurbin, A; Boissin-Agasse, L; Orcel, H; Rabié, A; Joux, N; Desarménien, M G; Richard, P; Moos, F C

1998-11-01

We have identified and visualized the vasopressin (VP) receptors expressed by hypothalamic magnocellular neurons in supraoptic and paraventricular nuclei. To do this, we used RT-PCR on total RNA extracts from supraoptic nuclei or on single freshly dissociated supraoptic neurons, and in situ hybridization on frontal sections of hypothalamus of Wistar rats. The RT-PCR on supraoptic RNA extracts revealed that mainly V1a, but also V1b, subtypes of VP receptors are expressed from birth to adulthood. No V2 receptor messenger RNA (mRNA) was detected. Furthermore, the single-cell RT-nested PCR indicated that the V1a receptor mRNA is present in vasopressinergic magnocellular neurons. In light of these results, in situ hybridization was performed to visualize the V1a and V1b receptor mRNAs in supraoptic and paraventricular nuclei. Simultaneously, we coupled this approach to: 1) in situ hybridization detection of oxytocin or VP mRNAs; or 2) immunocytochemistry to detect the neuropeptides. This provided a way of identifying the neurons expressing perceptible amounts of V1a or V1b receptor mRNAs as vasopressinergic neurons. Here, we suggest that the autocontrol exerted specifically by VP on vasopressinergic neurons is mediated through, at least, V1a and V1b subtype receptors.

Glial cells isolated from dorsal root ganglia express prostaglandin E(2) (EP(4)) and prostacyclin (IP) receptors.

PubMed

Ng, Kai Yu; Wong, Yung Hou; Wise, Helen

2011-07-01

Isolated cells from adult rat dorsal root ganglia (DRG) are frequently used as a model system to study responses of primary sensory neurons to nociceptor sensitizing agents such as prostaglandin E(2) and prostacyclin, which are presumed to act only on the neurons in typical mixed cell cultures. In the present study, we evaluated the expression of prostaglandin E(2) (EP(4)) and prostacyclin (IP) receptors in cultures of mixed DRG cells and in purified DRG glia. We show here that EP(4) and IP receptor agonists stimulated adenylyl cyclase activity in both mixed DRG cells and in purified DRG glia, and that these responses were specifically inhibited by EP(4) and IP receptor antagonists, respectively. The presence of EP(4) and IP receptors in DRG glia was further confirmed by the expression of EP(4) and IP receptor immunoreactivity and mRNA. With the increasing awareness of neuron-glial interactions within intact DRG and the use of isolated DRG cells in the study of mechanisms underlying nociception, it will be essential to consider the role played by EP(4) and IP receptor-expressing glial cells when evaluating prostanoid-induced sensitization of DRG neurons. Copyright © 2011 Elsevier B.V. All rights reserved.

NK cells and their receptors in naive and rituximab-treated patients with anti-MAG polyneuropathy.

PubMed

Benedetti, Luana; Facco, Monica; Franciotta, Diego; Dalla Torre, Chiara; Campagnolo, Marta; Lucchetta, Marta; Boscaro, Elisa; Ermani, Mario; Del Sette, Massimo; Berno, Tamara; Candiotto, Laura; Zambello, Renato; Briani, Chiara

2013-08-15

Natural killer (NK) cells can bridge innate and acquired immunity, and play a role in autoimmunity. A few studies evaluated the distribution of NK cells and the expression of their receptors in chronic immune-mediated demyelinating polyneuropathies. We investigated NK cell distribution and NK cell receptor expression in 20 naïve patients with anti-MAG polyneuropathy (MAG-PN). Using flow cytometry, we analysed NK cells and a series of NK cell receptors in the peripheral blood of patients with MAG-PN, and, as controls, in patients with chronic inflammatory demyelinating peripheral polyradiculoneuropathy (CIDP) and in healthy subjects. Six MAG-PN patients were also tested after rituximab treatment. At baseline the percentage of NK cells did not differ among the groups. KIR2DL2 receptor expression in MAG-PN patients was higher, andCD94/NKG2A receptor expression in both MAG-PN and CIDP patients was lower than in healthy controls. These abnormalities did not correlate with any clinical or demographic variable. No modification was found after rituximab therapy. The data suggest that MAG-PN shows abnormalities in NK cell receptors that characterise other autoimmune diseases, and cannot help in differential diagnosis with CIDP. The impairment of the relevant CD94/NKG2A inhibitory pathway, which might play a central role in the development and perpetuation of MAG-PN, warrants further functional investigations. Copyright © 2013 Elsevier B.V. All rights reserved.

Lysergic acid diethylamide-induced Fos expression in rat brain: role of serotonin-2A receptors.

PubMed

Gresch, P J; Strickland, L V; Sanders-Bush, E

2002-01-01

Lysergic acid diethylamide (LSD) produces altered mood and hallucinations in humans and binds with high affinity to serotonin-2A (5-HT(2A)) receptors. Although LSD interacts with other receptors, the activation of 5-HT(2A) receptors is thought to mediate the hallucinogenic properties of LSD. The goal of this study was to identify the brain sites activated by LSD and to determine the influence of 5-HT(2A) receptors in this activation. Rats were pretreated with the 5-HT(2A) receptor antagonist MDL 100907 (0.3 mg/kg, i.p.) or vehicle 30 min prior to LSD (500 microg/kg, i.p.) administration and killed 3 h later. Brain tissue was examined for Fos protein expression by immunohistochemistry. LSD administration produced a five- to eight-fold increase in Fos-like immunoreactivity in medial prefrontal cortex, anterior cingulate cortex, and central nucleus of amygdala. However, in dorsal striatum and nucleus accumbens no increase in Fos-like immunoreactivity was observed. Pretreatment with MDL 100907 completely blocked LSD-induced Fos-like immunoreactivity in medial prefrontal cortex and anterior cingulate cortex, but only partially blocked LSD-induced Fos-like immunoreactivity in amygdala. Double-labeled immunohistochemistry revealed that LSD did not induce Fos-like immunoreactivity in cortical cells expressing 5-HT(2A) receptors, suggesting an indirect activation of cortical neurons. These results indicate that the LSD activation of medial prefrontal cortex and anterior cingulate cortex is mediated by 5-HT(2A) receptors, whereas in amygdala 5-HT(2A) receptor activation is a component of the response. These findings support the hypothesis that the medial prefrontal cortex, anterior cingulate cortex, and perhaps the amygdala, are important regions involved in the production of hallucinations. Copyright 2002 IBRO

Expression and characterization of human CB1 cannabinoid receptor in methylotrophic yeast Pichia pastoris.

PubMed

Kim, Tae-Kang; Zhang, Rundong; Feng, Wenke; Cai, Jian; Pierce, William; Song, Zhao-Hui

2005-03-01

For the purpose of purification and structural characterization, the CB1 cannabinoid receptors are expressed in methylotrophic yeast Pichia pastoris. The expression plasmid was constructed in which the CB1 gene is under the control of the highly inducible promoter of P. pastoris alcohol oxidase I gene. To facilitate easy detection and purification, a FLAG tag was introduced at the N-terminal, a c-myc epitope and a hexahistidine tag were introduced at the C-terminal of the CB1. In membrane preparations of CB1 gene transformed yeast cells, Western blot analysis detected the expression of CB1 proteins. Radioligand binding assays demonstrated that the tagged CB1 receptors expressed in P. pastoris have a pharmacological profile similar to that of the untagged CB1 receptors expressed in mammalian systems. Furthermore, the tagged CB1 receptors were purified by anti-FLAG M2 affinity chromatography and the identity of the purified CB1 receptor proteins was confirmed by Western blot analysis. MALDI/TOF mass spectrometry analysis of the peptides extracted from tryptic digestions of purified CB1 preparations detected 17 peptide fragments derived from the CB1, thus further confirming the identity of the purified receptor. In conclusion, these data demonstrated for the first time that epitope tagged, functional CB1 cannabinoid receptors can be expressed in P. pastoris for purification and mass spectrometry characterization.

Voltage-gated sodium channels in taste bud cells.

PubMed

Gao, Na; Lu, Min; Echeverri, Fernando; Laita, Bianca; Kalabat, Dalia; Williams, Mark E; Hevezi, Peter; Zlotnik, Albert; Moyer, Bryan D

2009-03-12

Taste bud cells transmit information regarding the contents of food from taste receptors embedded in apical microvilli to gustatory nerve fibers innervating basolateral membranes. In particular, taste cells depolarize, activate voltage-gated sodium channels, and fire action potentials in response to tastants. Initial cell depolarization is attributable to sodium influx through TRPM5 in sweet, bitter, and umami cells and an undetermined cation influx through an ion channel in sour cells expressing PKD2L1, a candidate sour taste receptor. The molecular identity of the voltage-gated sodium channels that sense depolarizing signals and subsequently initiate action potentials coding taste information to gustatory nerve fibers is unknown. We describe the molecular and histological expression profiles of cation channels involved in electrical signal transmission from apical to basolateral membrane domains. TRPM5 was positioned immediately beneath tight junctions to receive calcium signals originating from sweet, bitter, and umami receptor activation, while PKD2L1 was positioned at the taste pore. Using mouse taste bud and lingual epithelial cells collected by laser capture microdissection, SCN2A, SCN3A, and SCN9A voltage-gated sodium channel transcripts were expressed in taste tissue. SCN2A, SCN3A, and SCN9A were expressed beneath tight junctions in subsets of taste cells. SCN3A and SCN9A were expressed in TRPM5 cells, while SCN2A was expressed in TRPM5 and PKD2L1 cells. HCN4, a gene previously implicated in sour taste, was expressed in PKD2L1 cells and localized to cell processes beneath the taste pore. SCN2A, SCN3A and SCN9A voltage-gated sodium channels are positioned to sense initial depolarizing signals stemming from taste receptor activation and initiate taste cell action potentials. SCN2A, SCN3A and SCN9A gene products likely account for the tetrodotoxin-sensitive sodium currents in taste receptor cells.

Role of Endocrine Gland-Derived Vascular Endothelial Growth Factor (EG-VEGF) and Its Receptors in Adrenocortical Tumors.

PubMed

Heck, Dorothee; Wortmann, Sebastian; Kraus, Luitgard; Ronchi, Cristina L; Sinnott, Richard O; Fassnacht, Martin; Sbiera, Silviu

2015-12-01

Angiogenesis is essential for tumor growth and metastasis. Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) is an angiogenic factor predominantly expressed in steroidogenic organs like the adrenal gland, ovary, testes, and placenta. EG-VEGF has antiapoptotic, mitogenic, and chemoattractive properties mediated via the two G protein-coupled receptors prokineticin receptor 1 (PKR1) and prokineticin receptor 2 (PKR2). We investigated the expression of EG-VEGF and its receptors in a large number of normal adrenal glands (NAG), adrenocortical adenomas (ACA), and carcinomas (ACC) using real-time PCR (NAG, n = 12; ACA, n = 24; and ACC, n = 30) and immunohistochemistry (NAG, n = 9; ACA, n = 23; and ACC, n = 163) and evaluated its impact on patients' survival. EG-VEGF, PKR1, and PKR2 mRNA and protein are expressed in NAG and the vast majority of ACA and ACC samples. The mean EG-VEGF mRNA expression was significantly lower in ACC (606.5 ± 77.1 copies) compared to NAG (4,043 ± 1,111) and cortisol-producing adenomas (CPA) (4,433 ± 2,378) (p < 0.01 and p < 0.05, respectively). However, cytoplasmic and nuclear EG-VEGF protein expression was either significantly higher or similar in ACC (H score 2.4 ± 0.05, p < 0.05 and 1.7 ± 0.08, n.s., respectively) compared to NAG (1.8 ± 0.14 and 1.7 ± 0.2). Nuclear protein expression of either EG-VEGF or PKR1 or both is predictive for a higher mortality compared to patients without nuclear expression (hazard ratio (HR) = 5.15; 95% confidence interval (CI) = 1.24-21.36, n = 100, p = 0.02 independent of age, sex, and tumor stage). These findings suggest that EG-VEGF and its receptor PKR1 might play a role in the pathogenesis of adrenocortical tumors and could serve as prognostic markers for this rare malignant disease.

The dopamine D1 receptor is expressed and facilitates relaxation in airway smooth muscle.

PubMed

Mizuta, Kentaro; Zhang, Yi; Xu, Dingbang; Mizuta, Fumiko; D'Ovidio, Frank; Masaki, Eiji; Emala, Charles W

2013-09-02

Dopamine signaling is mediated by Gs protein-coupled "D1-like" receptors (D1 and D5) and Gi-coupled "D2-like" receptors (D2-4). In asthmatic patients, inhaled dopamine induces bronchodilation. Although the Gi-coupled dopamine D2 receptor is expressed and sensitizes adenylyl cyclase activity in airway smooth muscle (ASM) cells, the Gs-coupled dopamine D1-like receptor subtypes have never been identified on these cells. Activation of Gs-coupled receptors stimulates cyclic AMP (cAMP) production through the stimulation of adenylyl cyclase, which promotes ASM relaxation. We questioned whether the dopamine D1-like receptor is expressed on ASM, and modulates its function through Gs-coupling. The mRNA and protein expression of dopamine D1-like receptor subtypes in both native human and guinea pig ASM tissue and cultured human ASM (HASM) cells was measured. To characterize the stimulation of cAMP through the dopamine D1 receptor, HASM cells were treated with dopamine or the dopamine D1-like receptor agonists (A68930 or SKF38393) before cAMP measurements. To evaluate whether the activation of dopamine D1 receptor induces ASM relaxation, guinea pig tracheal rings suspended under isometric tension in organ baths were treated with cumulatively increasing concentrations of dopamine or A68930, following an acetylcholine-induced contraction with or without the cAMP-dependent protein kinase (PKA) inhibitor Rp-cAMPS, the large-conductance calcium-activated potassium (BKCa) channel blocker iberiotoxin, or the exchange proteins directly activated by cAMP (Epac) antagonist NSC45576. Messenger RNA encoding the dopamine D1 and D5 receptors were detected in native human ASM tissue and cultured HASM cells. Immunoblots confirmed the protein expression of the dopamine D1 receptor in both native human and guinea pig ASM tissue and cultured HASM cells. The dopamine D1 receptor was also immunohistochemically localized to both human and guinea pig ASM. The dopamine D1-like receptor agonists stimulated cAMP production in HASM cells, which was reversed by the selective dopamine D1-like receptor antagonists SCH23390 or SCH39166. A68930 relaxed acetylcholine-contracted guinea pig tracheal rings, which was attenuated by Rp-cAMPS but not by iberiotoxin or NSC45576. These results demonstrate that the dopamine D1 receptors are expressed on ASM and regulate smooth muscle force via cAMP activation of PKA, and offer a novel target for therapeutic relaxation of ASM.

The dopamine D1 receptor is expressed and facilitates relaxation in airway smooth muscle

PubMed Central

2013-01-01

Background Dopamine signaling is mediated by Gs protein-coupled “D1-like” receptors (D1 and D5) and Gi-coupled “D2-like” receptors (D2-4). In asthmatic patients, inhaled dopamine induces bronchodilation. Although the Gi-coupled dopamine D2 receptor is expressed and sensitizes adenylyl cyclase activity in airway smooth muscle (ASM) cells, the Gs-coupled dopamine D1-like receptor subtypes have never been identified on these cells. Activation of Gs-coupled receptors stimulates cyclic AMP (cAMP) production through the stimulation of adenylyl cyclase, which promotes ASM relaxation. We questioned whether the dopamine D1-like receptor is expressed on ASM, and modulates its function through Gs-coupling. Methods The mRNA and protein expression of dopamine D1-like receptor subtypes in both native human and guinea pig ASM tissue and cultured human ASM (HASM) cells was measured. To characterize the stimulation of cAMP through the dopamine D1 receptor, HASM cells were treated with dopamine or the dopamine D1-like receptor agonists (A68930 or SKF38393) before cAMP measurements. To evaluate whether the activation of dopamine D1 receptor induces ASM relaxation, guinea pig tracheal rings suspended under isometric tension in organ baths were treated with cumulatively increasing concentrations of dopamine or A68930, following an acetylcholine-induced contraction with or without the cAMP-dependent protein kinase (PKA) inhibitor Rp-cAMPS, the large-conductance calcium-activated potassium (BKCa) channel blocker iberiotoxin, or the exchange proteins directly activated by cAMP (Epac) antagonist NSC45576. Results Messenger RNA encoding the dopamine D1 and D5 receptors were detected in native human ASM tissue and cultured HASM cells. Immunoblots confirmed the protein expression of the dopamine D1 receptor in both native human and guinea pig ASM tissue and cultured HASM cells. The dopamine D1 receptor was also immunohistochemically localized to both human and guinea pig ASM. The dopamine D1-like receptor agonists stimulated cAMP production in HASM cells, which was reversed by the selective dopamine D1-like receptor antagonists SCH23390 or SCH39166. A68930 relaxed acetylcholine-contracted guinea pig tracheal rings, which was attenuated by Rp-cAMPS but not by iberiotoxin or NSC45576. Conclusions These results demonstrate that the dopamine D1 receptors are expressed on ASM and regulate smooth muscle force via cAMP activation of PKA, and offer a novel target for therapeutic relaxation of ASM. PMID:24004608

Receptors rather than signals change in expression in four physiological regulatory networks during evolutionary divergence in threespine stickleback.

PubMed

Di Poi, Carole; Bélanger, Dominic; Amyot, Marc; Rogers, Sean; Aubin-Horth, Nadia

2016-07-01

The molecular mechanisms underlying behavioural evolution following colonization of novel environments are largely unknown. Molecules that interact to control equilibrium within an organism form physiological regulatory networks. It is essential to determine whether particular components of physiological regulatory networks evolve or if the network as a whole is affected in populations diverging in behavioural responses, as this may affect the nature, amplitude and number of impacted traits. We studied the regulation of four physiological regulatory networks in freshwater and marine populations of threespine stickleback raised in a common environment, which were previously characterized as showing evolutionary divergence in behaviour and stress reactivity. We measured nineteen components of these networks (ligands and receptors) using mRNA and monoamine levels in the brain, pituitary and interrenal gland, as well as hormone levels. Freshwater fish showed higher expression in the brain of adrenergic (adrb2a), serotonergic (htr2a) and dopaminergic (DRD2) receptors, but lower expression of the htr2b receptor. Freshwater fish also showed higher expression of the mc2r receptor of the glucocorticoid axis in the interrenals. Collectively, our results suggest that the inheritance of the regulation of these networks may be implicated in the evolution of behaviour and stress reactivity in association with population divergence. Our results also suggest that evolutionary change in freshwater threespine stickleback may be more associated with the expression of specific receptors rather than with global changes of all the measured constituents of the physiological regulatory networks. © 2016 John Wiley & Sons Ltd.

Resveratrol-decreased hyperalgesia mediated by the P2X7 receptor in gp120-treated rats.

PubMed

Wu, Bing; Ma, Yucheng; Yi, Zhihua; Liu, Shuangmei; Rao, Shenqiang; Zou, Lifang; Wang, Shouyu; Xue, Yun; Jia, Tianyu; Zhao, Shanhong; Shi, Liran; Li, Lin; Yuan, Huilong; Liang, Shangdong

2017-01-01

Background Chronic pain is a common symptom in human immunodeficiency virus (HIV)-1 infection/acquired immunodeficiency syndrome patients. The literature shows that the HIV envelope glycoprotein 120 (gp120) can directly cause hyperalgesia by stimulating primary sensory afferent nerves. The P2X 7 receptor in the dorsal root ganglia (DRG) is closely related to neuropathic and inflammatory pain. In this study, we aimed to explore the effect of resveratrol (RES) on gp120-induced neuropathic pain that is mediated by the P2X 7 receptor in the rat DRG. Results Mechanical hyperalgesia in rats treated with gp120 was increased compared with that in the sham group. The P2X 7 expression levels in rats treated with gp120 were higher than those in the sham group. Co-localization of the P2X 7 receptor and glial fibrillary acidic protein (GFAP, a marker of satellite glial cells [SGCs]) in the DRG SGCs of the gp120 group exhibited more intense staining than that of the sham group. RES decreased the mechanical hyperalgesia and P2X 7 expression levels in gp120 treatment rats. Co-localization of the P2X 7 receptor and GFAP in the gp120+ RES group was significantly decreased compared to the gp120 group. RES decreased the IL-1β and TNF-α receptor (R) expression levels and ERK1/2 phosphorylation levels as well as increased IL-10 expression in the DRG of gp120-treated rats. Whole cell clamping demonstrated that RES significantly inhibited adenosine triphosphate-activated currents in HEK293 cells that were transfected with the P2X 7 plasmid. Conclusions RES relieved mechanical hyperalgesia in gp120-treated rats by inhibiting the P2X 7 receptor.

Membrane-bound LERK2 ligand can signal through three different Eph-related receptor tyrosine kinases.

PubMed Central

Brambilla, R; Schnapp, A; Casagranda, F; Labrador, J P; Bergemann, A D; Flanagan, J G; Pasquale, E B; Klein, R

1995-01-01

The Eph-related family of receptor tyrosine kinases consists of at least 13 members, several of which display distinctive expression patterns in the developing and adult nervous system. Recently, a small family of ligands, structurally related to the B61 protein, was identified. Binding of these ligands to Eph-related receptors did not, however, elicit measurable biological signals in cultured cells. In order to study functional interactions between B61-related ligands and Eph-related receptors, we constructed chimeric receptors, containing an Eph-related ectodomain and the cytoplasmic domain of the TrkB neurotrophin receptor. Expression and activation of such chimeric receptors in NIH 3T3 cells induced transformation in focus formation assays. Membrane-bound LERK2 ligand is shown to signal through three different Eph-related receptors, namely Cek5, Cek10 and Elk. LERK2, however, fails to interact functionally with the Cek9 receptor. Quantitative analysis including binding assays indicates that Cek10 is the preferred LERK2 receptor. Preliminary mutagenesis of the LERK2 protein suggests a negative regulatory role for its cytoplasmic domain in LERK2 signaling. Images PMID:7621826

Molecular mechanisms of repeated social defeat-induced glucocorticoid resistance: Role of microRNA.

PubMed

Jung, Seung Ho; Wang, Yufen; Kim, Taewan; Tarr, Andrew; Reader, Brenda; Powell, Nicole; Sheridan, John F

2015-02-01

Glucocorticoid (GC) resistance is a severe problem associated with various inflammatory diseases. Previous studies have shown that repeated social stress induces GC resistance in innate immune cells, but the underlying molecular mechanisms have not been fully elucidated. Therefore, the purpose of this study was to examine potential underlying molecular mechanism(s) of repeated social defeat (RSD) stress on GC resistance in splenic macrophages. It was hypothesized that mRNA expression of receptors for GC and nuclear translocating-associated regulators in splenic macrophages would be affected by RSD, and that these changes would be associated with epigenetic modification. The data showed that the mRNA expression of GC and mineralocorticoid receptors were significantly decreased in splenic macrophages by RSD. RSD also induced a significantly decreased mRNA expression in FK506-binding protein 52 (FKBP52), consequently resulting in a significantly increased ratio of FKBP51 to FKBP52. Moreover, DNA methyltransferases 3a and 3b showed a significant decrease in their mRNA expression in the RSD group as did mRNA expression of histone deacetyltransferase 2. The RSD group also showed a significantly reduced quantity of methylated DNA in splenic macrophages. Based on microRNA (miRNA) profiling data, it was determined that RSD induced significantly increased expression of 9 different miRNAs that were predicted to interact with mRNAs of the GC receptor (6 miRNAs), mineralocorticoid receptor (3 miRNAs) and FKBP52 (2 miRNAs). Spearman correlation analysis revealed significantly strong correlations between the expression of 2 miRNAs and their target mRNA expression for GC receptors. Among these miRNAs, we verified direct effects of miRNA-29b and -340 overexpression on mRNA expression of GC receptors in L929 cells. The overexpression of miRNA-29b or -340 in L929 cells significantly reduced LPS-induced overexpression of GC receptors. In conclusion, this study provides evidence that epigenetic regulation, such as DNA methylation and miRNA expression, may play a role in the RSD-induced GC resistance that we have observed in splenic macrophages. Copyright © 2014 Elsevier Inc. All rights reserved.

Molecular Mechanisms of Repeated Social Defeat-Induced Glucocorticoid Resistance: Role of microRNA

PubMed Central

Jung, Seung Ho; Wang, Yufen; Kim, Taewan; Tarr, Andrew; Reader, Brenda; Powell, Nicole; Sheridan, John F.

2014-01-01

Glucocorticoid (GC) resistance is a severe problem associated with various inflammatory diseases. Previous studies have shown that repeated social stress induces GC resistance in innate immune cells, but the underlying molecular mechanisms have not been fully elucidated. Therefore, the purpose of this study was to examine potential underlying molecular mechanism(s) of repeated social defeat (RSD) stress on GC resistance in splenic macrophages. It was hypothesized that mRNA expression of receptors for GC and nuclear translocating-associated regulators in splenic macrophages would be affected by RSD, and that these changes would be associated with epigenetic modification. The data showed that the mRNA expression of GC and mineralocorticoid receptors were significantly decreased in splenic macrophages by RSD. RSD also induced a significantly decreased mRNA expression in FK506-binding protein 52 (FKBP52), consequently resulting in a significantly increased ratio of FKBP51 to FKBP52. Moreover, DNA methyltransferases 3a and 3b showed a significant decrease in their mRNA expression in the RSD group as did mRNA expression of histone deacetyltransferase 2. The RSD group also showed a significantly reduced quantity of methylated DNA in splenic macrophages. Based on microRNA (miRNA) profiling data, it was determined that RSD induced significantly increased expression of 9 different miRNAs that were predicted to interact with mRNAs of the GC receptor (6 miRNAs), mineralocorticoid receptor (3 miRNAs) and FKBP52 (2 miRNAs). Spearman correlation analysis revealed significantly strong correlations between the expression of 2 miRNAs and their target mRNA expression for GC receptors. Among these miRNAs, we verified direct effects of miRNA-29b and -340 overexpression on mRNA expression of GC receptors in L929 cells. The overexpression of miRNA-29b or -340 in L929 cells significantly reduced LPS-induced overexpression of GC receptors. In conclusion, this study provides evidence that epigenetic regulation, such as DNA methylation and miRNA expression, may play a role in the RSD-induced GC resistance that we have observed in splenic macrophages. PMID:25317829

Effects of electroacupuncture at 2 and 100 Hz on rat type 2 diabetic neuropathic pain and hyperalgesia-related protein expression in the dorsal root ganglion.

PubMed

He, Xiao-Fen; Wei, Jun-Jun; Shou, Sheng-Yun; Fang, Jian-Qiao; Jiang, Yong-Liang

To investigate the analgesic effects of electroacupuncture (EA) at 2 and 100 Hz on type 2 diabetic neuropathic pain (DNP) and on the expressions of the P2X3 receptor and calcitonin gene-related peptide (CGRP) in the dorsal root ganglion (DRG). Rat type 2 DNP was induced by a high calorie and high sugar diet fed for 7 weeks, plus a single intraperitoneal injection of streptozotocin (STZ) after 5 weeks. EA at 2 and 100 Hz was carried out once every day after 7 weeks for 7 consecutive days. Body weight, serum fasting insulin (FINS), fasting blood glucose (FBG), insulin sensitivity index (ISI), and paw withdrawal latency (PWL) were measured. The expressions of L4-L6 DRG P2X3 receptors and CGRP were assessed by immunofluorescence. Type 2 DNP was successfully induced as shown by the increased body weight, FINS, and FBG, as well as the reduced ISI and PWL. Expressions of P2X3 receptors and CGRP in L4-L6 DRGs increased. EA at both 2 and 100 Hz relieved type 2 DNP, but the analgesic effect of EA was stronger at 2 Hz. P2X3 receptor expression decreased in L4-L6 DRGs following EA at 2 Hz and in L5 and L6 DRGs following EA at 100 Hz. EA at both 2 and 100 Hz down-regulated CGRP overexpression in L4-L6 DRGs. These findings indicate that EA at 2 Hz is a good option for the management of type 2 DNP. The EA effect may be related to its down-regulation of the overexpressions of the DRG P2X3 receptors and CGRP in this condition.

Increased expression of both insulin receptor substrates 1 and 2 confers increased sensitivity to IGF-1 stimulated cell migration.

PubMed

de Blaquière, Gail E; May, Felicity E B; Westley, Bruce R

2009-06-01

Insulin-like growth factors (IGFs) are thought to promote tumour progression and metastasis in part by stimulating cell migration. Insulin receptor substrate-1 (IRS-1) and IRS-2 are multisite docking proteins positioned immediately downstream from the type I IGF and insulin receptors. IRS-2 but not IRS-1 has been reported to be involved in the migratory response of breast cancer cells to IGFs. The purpose of this investigation was to determine if IRS-1 is involved in, and to assess the contributions of IRS-1 and IRS-2 to, the migratory response of breast cancer cells to IGFs. The expression of IRS-1 and IRS-2 varied considerably between ten breast cancer cell lines. Oestrogen increases expression of the type I IGF receptor, IRS-1 and IRS-2 in MCF-7 and ZR-75 cells. Oestrogens may control the sensitivity of breast cancer cells to IGFs by regulating the expression of components of the IGF signal transduction pathway. The migratory response to a range of IGF-1 concentrations was measured in MCF-7 and MDA-MB-231 breast cancer cells in which IRS-1 and IRS-2 levels were modulated using a doxycycline-inducible expression system. Induction of both IRS-1 and IRS-2 expression increased the sensitivity of the migratory response to IGF-1 but did not increase the magnitude of the response stimulated at higher concentrations of IGF-1. Knockdown of IRS-1, IRS-2 and the type I IGF receptor in MCF-7 and MDA-MB-2231 cells decreased sensitivity to IGF-1. We conclude that both IRS-1 and IRS-2 control the migratory response of breast cancer cells to IGF-1 and may, therefore, be key molecules in determining breast cancer spread.

Expression and potential role of the peptide orexin-A in prostate cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Valiante, Salvatore; Liguori, Giovanna; Tafuri, Simona

The peptides orexin-A and orexin-B and their G protein-coupled OX1 and OX2 receptors are involved in multiple physiological processes in the central nervous system and peripheral organs. Altered expression or signaling dysregulation of orexins and their receptors have been associated with a wide range of human diseases including narcolepsy, obesity, drug addiction, and cancer. Although orexin-A, its precursor molecule prepro-orexin and OX1 receptor have been detected in the human normal and hyperplastic prostate tissues, their expression and function in the prostate cancer (PCa) remains to be addressed. Here, we demonstrate for the first time the immunohistochemical localization of orexin-A inmore » human PCa specimens, and the expression of prepro-orexin and OX1 receptor at both protein and mRNA levels in these tissues. Orexin-A administration to the human androgen-dependent prostate carcinoma cells LNCaP up-regulates OX1 receptor expression resulting in a decrease of cell survival. Noteworthy, nanomolar concentrations of the peptide counteract the testosterone-induced nuclear translocation of the androgen receptor in the cells: the orexin-A action is prevented by the addition of the OX1 receptor antagonist SB-408124 to the test system. These findings indicate that orexin-A/OX1 receptor interaction interferes with the activity of the androgen receptor which regulates PCa onset and progression, thus suggesting that orexin-A and its receptor might represent novel therapeutic targets to challenge this aggressive cancer. - Highlights: • Orexin-A and OX1 receptor are present in human cancer prostate tissues. • Orexin-A up-regulates OX1 receptor expression in LNCaP cells. • Orexin-A inhibits testosterone-induced nuclear translocation of androgen receptor.« less

Novel mechanisms and signaling pathways of esophageal ulcer healing: the role of prostaglandin EP2 receptors, cAMP, and pCREB

PubMed Central

Ahluwalia, Amrita; Baatar, Dolgor; Jones, Michael K.

2014-01-01

Clinical studies indicate that prostaglandins of E class (PGEs) may promote healing of tissue injury e.g., gastroduodenal and dermal ulcers. However, the precise roles of PGEs, their E-prostanoid (EP) receptors, signaling pathways including cAMP and cAMP response element-binding protein (CREB), and their relation to VEGF and angiogenesis in the tissue injury healing process remain unknown, forming the rationale for this study. Using an esophageal ulcer model in rats, we demonstrated that esophageal mucosa expresses predominantly EP2 receptors and that esophageal ulceration triggers an increase in expression of the EP2 receptor, activation of CREB (the downstream target of the cAMP signaling), and enhanced VEGF gene expression. Treatment of rats with misoprostol, a PGE1 analog capable of activating EP receptors, enhanced phosphorylation of CREB, stimulated VEGF expression and angiogenesis, and accelerated esophageal ulcer healing. In cultured human esophageal epithelial (HET-1A) cells, misoprostol increased intracellular cAMP levels (by 163-fold), induced phosphorylation of CREB, and stimulated VEGF expression. A cAMP analog (Sp-cAMP) mimicked, whereas an inhibitor of cAMP-dependent protein kinase A (Rp-cAMP) blocked, these effects of misoprostol. These results indicate that the EP2/cAMP/protein kinase A pathway mediates the stimulatory effect of PGEs on angiogenesis essential for tissue injury healing via the induction of CREB activity and VEGF expression. PMID:25059824

Leiomyoma-derived transforming growth factor-β impairs bone morphogenetic protein-2-mediated endometrial receptivity.

PubMed

Doherty, Leo F; Taylor, Hugh S

2015-03-01

To determine whether transforming growth factor (TGF)-β3 is a paracrine signal secreted by leiomyoma that inhibits bone morphogenetic protein (BMP)-mediated endometrial receptivity and decidualization. Experimental. Laboratory. Women with symptomatic leiomyomas. Endometrial stromal cells (ESCs) and leiomyoma cells were isolated from surgical specimens. Leiomyoma-conditioned media (LCM) was applied to cultured ESC. The TGF-β was blocked by two approaches: TGF-β pan-specific antibody or transfection with a mutant TGF-β receptor type II. Cells were then treated with recombinant human BMP-2 to assess BMP responsiveness. Expression of BMP receptor types 1A, 1B, 2, as well as endometrial receptivity mediators HOXA10 and leukemia inhibitory factor (LIF). Enzyme-linked immunosorbent assay showed elevated TGF-β levels in LCM. LCM treatment of ESC reduced expression of BMP receptor types 1B and 2 to approximately 60% of pretreatment levels. Preincubation of LCM with TGF-β neutralizing antibody or mutant TGF receptor, but not respective controls, prevented repression of BMP receptors. HOXA10 and LIF expression was repressed in recombinant human BMP-2 treated, LCM exposed ESC. Pretreatment of LCM with TGF-β antibody or transfection with mutant TGF receptor prevented HOXA10 and LIF repression. Leiomyoma-derived TGF-β was necessary and sufficient to alter endometrial BMP-2 responsiveness. Blockade of TGF-β prevents repression of BMP-2 receptors and restores BMP-2-stimulated expression of HOXA10 and LIF. Blockade of TGF signaling is a potential strategy to improve infertility and pregnancy loss associated with uterine leiomyoma. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Trek2a regulates gnrh3 expression under control of melatonin receptor Mt1 and α2-adrenoceptor.

PubMed

Loganathan, Kavinash; Moriya, Shogo; Parhar, Ishwar S

2018-02-12

Gonadotrophin-releasing hormone (GnRH) expression is associated with the two-pore domain potassium ion (K + ) channel-related K + (TREK) channel trek2a expression and melatonin levels. We aimed to investigate correlation of trek2a expression with gnrh3 expression, and regulatory mechanisms of trek2a expression by the melatonin receptor Mt1 and α 2 -adrenoceptor which are regulated by melatonin. trek2a specific siRNA, Mt1 antagonist luzindole and α 2 -adrenoceptor antagonist prazosin were administered into the adult zebrafish brain and gene expressions were examined by real-time PCR. trek2a specific siRNA administration significantly reduced expression levels of trek2a, gnrh3 and mt1. Luzindole administration suppressed trek2a and gnrh3 expressions. Prazosin administration reduced trek2a and gnrh3 expressions. It is suggested that Trek2a regulates gnrh3 expression under the control of Mt1 and α 2 -adrenoceptor. Copyright © 2018 Elsevier Inc. All rights reserved.

Sensitization of transient receptor potential vanilloid 1 by the prokineticin receptor agonist Bv8.

PubMed

Vellani, Vittorio; Colucci, Mariantonella; Lattanzi, Roberta; Giannini, Elisa; Negri, Lucia; Melchiorri, Pietro; McNaughton, Peter A

2006-05-10

Small mammalian proteins called the prokineticins [prokineticin 1 (PK1) and PK2] and two corresponding G-protein-coupled receptors [prokineticin receptor 1 (PKR1) and PKR2] have been identified recently, but the physiological role of the PK/PKR system remains mostly unexplored. Bv8, a protein extracted from frog skin, is a convenient and potent agonist for both PKR1 and PKR2, and injection of Bv8 in vivo causes a potent and long-lasting hyperalgesia. Here, we investigate the cellular basis of hyperalgesia caused by activation of PKRs. Bv8 caused increases in [Ca]i in a population of isolated dorsal root ganglion (DRG) neurons, which we identified as nociceptors, or sensors for painful stimuli, from their responses to capsaicin, bradykinin, mustard oil, or proteases. Bv8 enhanced the inward current carried by the heat and capsaicin receptor, transient receptor potential vanilloid 1 (TRPV1) via a pathway involving activation of protein kinase Cepsilon (PKCepsilon), because Bv8 caused translocation of PKCepsilon to the neuronal membrane and because PKC antagonists reduced both the enhancement of current carried by TRPV1 and behavioral hyperalgesia in rodents. The neuronal population expressing PKRs consisted partly of small peptidergic neurons and partly of neurons expressing the N52 marker for myelinated fibers. Using single-cell reverse transcriptase-PCR, we found that mRNA for PKR1 was mainly expressed in small DRG neurons. Exposure to GDNF (glial cell line-derived neurotrophic factor) induced de novo expression of functional receptors for Bv8 in a nonpeptidergic population of neurons. These results show that prokineticin receptors are expressed in nociceptors and cause heat hyperalgesia by sensitizing TRPV1 through activation of PKCepsilon. The results suggest a role for prokineticins in physiological inflammation and hyperalgesia.

Effect of Valsartan on Cerebellar Adrenomedullin System Dysregulation During Hypertension.

PubMed

Figueira, Leticia; Israel, Anita

2017-02-01

Adrenomedullin (AM) and its receptors components, calcitonin-receptor-like receptor (CRLR), and receptor activity-modifying protein (RAMP1, RAMP2, and RAMP3) are expressed in cerebellum. Cerebellar AM, AM binding sites and receptor components are altered during hypertension, suggesting a role for cerebellar AM in blood pressure regulation. Thus, we assessed the effect of valsartan, on AM and its receptor components expression in the cerebellar vermis of Wistar Kyoto (WKY) and spontaneously hypertensive (SHR) rats. Additionally, we evaluated AM action on superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activity, and thiobarbituric acid reactive substances (TBARS) production in cerebellar vermis. Animals were treated with valsartan or vehicle for 11 days. Rats were sacrificed by decapitation; cerebellar vermis was dissected; and AM, CRLR, RAMP1, RAMP2, and RAMP3 expression was quantified by Western blot analysis. CAT, SOD, and GPx activity was determined spectrophotometrically and blood pressure by non-invasive plethysmography. We demonstrate that AM and RAMP2 expression was lower in cerebellum of SHR rats, while CRLR, RAMP1, and RAMP3 expression was higher than those of WKY rats. AM reduced cerebellar CAT, SOD, GPx activities, and TBARS production in WKY rats, but not in SHR rats. Valsartan reduced blood pressure and reversed the altered expression of AM and its receptors components, as well the loss of AM capacity to reduce antioxidant enzyme activity and TBARS production in SHR rats. These findings demonstrate that valsartan is able to reverse the dysregulation of cerebellar adrenomedullinergic system; and they suggest that altered AM system in the cerebellum could represent the primary abnormality leading to hypertension.

Evaluation of somatostatin, CXCR4 chemokine and endothelin A receptor expression in a large set of paragangliomas.

PubMed

Kaemmerer, Daniel; Sänger, Jörg; Arsenic, Ruza; D'Haese, Jan G; Neumann, Jens; Schmitt-Graeff, Annette; Wirtz, Ralph Markus; Schulz, Stefan; Lupp, Amelie

2017-10-27

Paragangliomas are predominantly benign tumors, but in some cases invasive growth and also metastasis are observed. Given the limited number of nonsurgical treatment options, novel target structures for diagnostics and therapy of this tumor entity are urgently needed. In the present study, expression of all five somatostatin receptor (SST) subtypes, chemokine receptor CXCR4 and endothelin receptor type A (ETA) was assessed by means of immunohistochemistry in a total of 66 paraffin-embedded paraganglioma samples from 55 patients. The stainings were rated by means of the Immunoreactive Score and correlated to clinical data and to succinate dehydrogenase subunit B (SDHB) expression. SST2A was by far the most prominent receptor in the paragangliomas investigated. It was present in 89% of the tumors at a high intensity, followed by SST5, SST3, SST1 and SST4, which were detected in 47%, 35%, 35% and 13% of the samples, respectively. SDHB positive tumors exhibited significantly higher SST2A and SST3 expression as compared to SDHB negative cases. There was no correlation between SST and Ki-67 expression or grading of the tumors and no difference in SST expression between primary tumors and metastases. Cell surface expression of CXCR4 and ETA was detected only in few samples. On tumor capillaries, however, exceptionally strong staining for these two receptors was noticed in the vast majority of the tumors. In conclusion, paragangliomas are well suited for SST2A-based diagnostics and treatment modalities. An indirect targeting of these highly vascularized tumors via CXCR4 or ETA may also represent a promising future strategy.

Evaluation of somatostatin, CXCR4 chemokine and endothelin A receptor expression in a large set of paragangliomas

PubMed Central

Kaemmerer, Daniel; Sänger, Jörg; Arsenic, Ruza; D’Haese, Jan G.; Neumann, Jens; Schmitt-Graeff, Annette; Wirtz, Ralph Markus; Schulz, Stefan; Lupp, Amelie

2017-01-01

Paragangliomas are predominantly benign tumors, but in some cases invasive growth and also metastasis are observed. Given the limited number of nonsurgical treatment options, novel target structures for diagnostics and therapy of this tumor entity are urgently needed. In the present study, expression of all five somatostatin receptor (SST) subtypes, chemokine receptor CXCR4 and endothelin receptor type A (ETA) was assessed by means of immunohistochemistry in a total of 66 paraffin-embedded paraganglioma samples from 55 patients. The stainings were rated by means of the Immunoreactive Score and correlated to clinical data and to succinate dehydrogenase subunit B (SDHB) expression. SST2A was by far the most prominent receptor in the paragangliomas investigated. It was present in 89% of the tumors at a high intensity, followed by SST5, SST3, SST1 and SST4, which were detected in 47%, 35%, 35% and 13% of the samples, respectively. SDHB positive tumors exhibited significantly higher SST2A and SST3 expression as compared to SDHB negative cases. There was no correlation between SST and Ki-67 expression or grading of the tumors and no difference in SST expression between primary tumors and metastases. Cell surface expression of CXCR4 and ETA was detected only in few samples. On tumor capillaries, however, exceptionally strong staining for these two receptors was noticed in the vast majority of the tumors. In conclusion, paragangliomas are well suited for SST2A-based diagnostics and treatment modalities. An indirect targeting of these highly vascularized tumors via CXCR4 or ETA may also represent a promising future strategy. PMID:29163802

ESR1 gene amplification in endometrial carcinomas: a clinicopathological analysis.

PubMed

Rahman, Mohammed Tanjimur; Nakayama, Kentaro; Rahman, Munmun; Ishikawa, Masako; Katagiri, Hiroshi; Katagiri, Atsuko; Ishibashi, Tomoka; Sato, Emi; Iida, Kouji; Ishikawa, Noriyuki; Nakayama, Naomi; Miyazaki, Kohji

2013-09-01

This study investigated the clinicopathological significance of estrogen receptor 1 (ESR1) gene amplification and its relationship to phosphatase and tensin homolog (PTEN), human epidermal growth factor receptor 2 (HER2), MutL homolog 1 (MLH1), p53, and AT rich interactive domain 1A (ARID1A) expression in endometrial carcinomas. ESR1 amplification and expression were assessed by fluorescence in situ hybridization and immunohistochemistry. Clinical data were collected by retrospective chart review. ESR1 amplification was identified in 13 out of 111 (11.7%) endometrial carcinomas. No significant association was observed between ESR1 amplification and International Federation of Gynecology and Obstetrics (FIGO) stage (p=0.17), histological grade (p=0.35), lymph node metastasis (p=0.51), or deep myometrial invasion (p=0.46). ESR1 amplification was independent of PTEN, p53, HER2, MLH1, and ARID1A protein expression. Patients without estrogen receptor (ER) or progesterone receptor (PR) expression had shorter progression-free and overall survival than those with ER or PR expression (p<0.01). ESR1 amplification is independent of known clinicopathological factors related to poor prognosis and PTEN, p53, HER2, MLH1, and ARID1A protein expression, suggesting ESR1 amplification may be an early event in endometrial carcinoma development.

Chemokine and Chemokine Receptor Profiles in Metastatic Salivary Adenoid Cystic Carcinoma.

PubMed

Mays, Ashley C; Feng, Xin; Browne, James D; Sullivan, Christopher A

2016-08-01

To characterize the chemokine pattern in metastatic salivary adenoid cystic carcinoma (SACC). Real-time polymerase chain reaction (RT-PCR) was used to compare chemokine and chemokine receptor gene expression in two SACC cell lines: SACC-83 and SACC-LM (lung metastasis). Chemokines and receptor genes were then screened and their expression pattern characterized in human tissue samples of non-recurrent SACC and recurrent SACC with perineural invasion. Expression of chemokine receptors C5AR1, CCR1, CCR3, CCR6, CCR7, CCR9, CCR10, CXCR4, CXCR6, CXCR7, CCRL1 and CCRL2 were higher in SACC-83 compared to SACC-LM. CCRL1, CCBP2, CMKLR1, XCR1 and CXCR2 and 6 chemokine genes (CCL13, CCL27, CXCL14, CMTM1, CMTM2, CKLF) were more highly expressed in tissues of patients without tumor recurrence/perineural invasion compared to those with tumor recurrence. CCRL1 (receptor), CCL27, CMTM1, CMTM2, and CKLF (chemokine) genes were more highly expressed in SACC-83 and human tissues of patients without tumor recurrence/perineural invasion. CCRL1, CCL27, CMTM1, CMTM2 and CKLF may play important roles in the development of tumor metastases in SACC. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Characterization of melanin-concentrating hormone (MCH) and its receptor in chickens: Tissue expression, functional analysis, and fasting-induced up-regulation of hypothalamic MCH expression.

PubMed

Cui, Lin; Lv, Can; Zhang, Jiannan; Mo, Chunheng; Lin, Dongliang; Li, Juan; Wang, Yajun

2017-06-05

Melanin-concentrating hormone (MCH) is a neuropeptide expressed in the brain and exerts its actions through interaction with the two known G protein-coupled receptors, namely melanin-concentrating hormone receptor 1 and 2 (MCHR1 and MCHR2) in mammals. However, the information regarding the expression and functionality of MCH and MCHR(s) remains largely unknown in birds. In this study, using RT-PCR and RACE PCR, we amplified and cloned a MCHR1-like receptor, which is named cMCHR4 according to its evolutionary origin, and a MCHR2 from chicken brain. The cloned cMCHR4 was predicted to encode a receptor of 367 amino acids, which shares high amino acid identities with MCHR4 of ducks (90%), western painted turtles (85%), and coelacanths (77%), and a comparatively low identity to human MCHR1 (58%) and MCHR2 (38%), whereas chicken MCHR2 encodes a putative C-terminally truncated receptor and is likely a pseudogene. Using cell-based luciferase reporter assays or Western blot, we further demonstrated that chicken (and duck) MCHR4 could be potently activated by chicken MCH 1-19 , and its activation can elevate calcium concentration and activate MAPK/ERK and cAMP/PKA signaling pathways, indicating an important role of MCHR4 in mediating MCH actions in birds. Quantitative real-time PCR revealed that both cMCH and cMCHR4 mRNA are expressed in various brain regions including the hypothalamus, and cMCH expression in the hypothalamus of 3-week-old chicks could be induced by 36-h fasting, indicating that cMCH expression is correlated with energy balance. Taken together, characterization of chicken MCH and MCHR4 will aid to uncover the conserved roles of MCH across vertebrates. Copyright © 2017 Elsevier B.V. All rights reserved.

Expression of GABA receptor subunits in the hippocampus and thalamus after experimental traumatic brain injury

PubMed Central

Drexel, Meinrad; Puhakka, Noora; Kirchmair, Elke; Hörtnagl, Heide; Pitkänen, Asla; Sperk, Günther

2015-01-01

Traumatic brain injury is a major cause of death and disability worldwide and often associated with post-traumatic epilepsy. We recently demonstrated that TBI induces acquired GABAA receptors channelopathy that associates with hyperexcitability in granule cell layer (GCL). We now assessed the expression of GABAA and GABAB receptor subunit mRNAs between 6 h and 6 months post-TBI in the hippocampus and thalamus. The expression of major GABAA receptor subunit mRNAs (α1, α2, α5, β2, β3, γ2 and δ) was, often bilaterally, down-regulated in the GCL and in the CA3 pyramidal cells. Instead, expression of α4 (GCL, CA3, CA1), α5 (CA1) and γ2 (GCL, CA3, CA1) mRNA was up-regulated after 10 d and/or 4 months. Many of these changes were reversible. In the thalamus, we found decreases in α1, α4, β2, γ2 and δ mRNAs in the laterodorsal thalamus and in the area combining the posterior thalamic nuclear group, ventroposterolateral and ventroposteromedial complex at 6 h to 4 months post-TBI. Unlike in the hippocampus, thalamic subunit down-regulations were irreversible and limited to the ipsilateral side. However, contralaterally there was up-regulation of the subunits δ and α4 6 h and 4 months after TBI, respectively. PCR array analysis suggested a mild long-lasting GABAA receptor channelopathy in the GCL and thalamus after TBI. Whereas TBI induces transient changes in the expression of GABAA receptor subunits in the hippocampus (presumably representing compensatory mechanisms), alterations of GABAA receptor subunit mRNAs in the thalamus are long-lasting and related to degeneration of receptor-containing neurons in thalamo-cortical relay nuclei. This article is part of the Special Issue entitled ‘GABAergic Signaling in Health and Disease’. PMID:25229716

Expression of GABA receptor subunits in the hippocampus and thalamus after experimental traumatic brain injury.

PubMed

Drexel, Meinrad; Puhakka, Noora; Kirchmair, Elke; Hörtnagl, Heide; Pitkänen, Asla; Sperk, Günther

2015-01-01

Traumatic brain injury is a major cause of death and disability worldwide and often associated with post-traumatic epilepsy. We recently demonstrated that TBI induces acquired GABAA receptors channelopathy that associates with hyperexcitability in granule cell layer (GCL). We now assessed the expression of GABAA and GABAB receptor subunit mRNAs between 6 h and 6 months post-TBI in the hippocampus and thalamus. The expression of major GABAA receptor subunit mRNAs (α1, α2, α5, β2, β3, γ2 and δ) was, often bilaterally, down-regulated in the GCL and in the CA3 pyramidal cells. Instead, expression of α4 (GCL, CA3, CA1), α5 (CA1) and γ2 (GCL, CA3, CA1) mRNA was up-regulated after 10 d and/or 4 months. Many of these changes were reversible. In the thalamus, we found decreases in α1, α4, β2, γ2 and δ mRNAs in the laterodorsal thalamus and in the area combining the posterior thalamic nuclear group, ventroposterolateral and ventroposteromedial complex at 6 h to 4 months post-TBI. Unlike in the hippocampus, thalamic subunit down-regulations were irreversible and limited to the ipsilateral side. However, contralaterally there was up-regulation of the subunits δ and α4 6 h and 4 months after TBI, respectively. PCR array analysis suggested a mild long-lasting GABAA receptor channelopathy in the GCL and thalamus after TBI. Whereas TBI induces transient changes in the expression of GABAA receptor subunits in the hippocampus (presumably representing compensatory mechanisms), alterations of GABAA receptor subunit mRNAs in the thalamus are long-lasting and related to degeneration of receptor-containing neurons in thalamo-cortical relay nuclei. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Activation of temperature-sensitive TRPV1-like receptors in ARC POMC neurons reduces food intake

PubMed Central

Jeong, Jae Hoon; Lee, Dong Kun; Liu, Shun-Mei; Chua, Streamson C.; Schwartz, Gary J.

2018-01-01

Proopiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus (ARC) respond to numerous hormonal and neural signals, resulting in changes in food intake. Here, we demonstrate that ARC POMC neurons express capsaicin-sensitive transient receptor potential vanilloid 1 receptor (TRPV1)-like receptors. To show expression of TRPV1-like receptors in ARC POMC neurons, we use single-cell reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry, electrophysiology, TRPV1 knock-out (KO), and TRPV1-Cre knock-in mice. A small elevation of temperature in the physiological range is enough to depolarize ARC POMC neurons. This depolarization is blocked by the TRPV1 receptor antagonist and by Trpv1 gene knockdown. Capsaicin-induced activation reduces food intake that is abolished by a melanocortin receptor antagonist. To selectively stimulate TRPV1-like receptor-expressing ARC POMC neurons in the ARC, we generate an adeno-associated virus serotype 5 (AAV5) carrying a Cre-dependent channelrhodopsin-2 (ChR2)–enhanced yellow fluorescent protein (eYFP) expression cassette under the control of the two neuronal POMC enhancers (nPEs). Optogenetic stimulation of TRPV1-like receptor-expressing POMC neurons decreases food intake. Hypothalamic temperature is rapidly elevated and reaches to approximately 39 °C during treadmill running. This elevation is associated with a reduction in food intake. Knockdown of the Trpv1 gene exclusively in ARC POMC neurons blocks the feeding inhibition produced by increased hypothalamic temperature. Taken together, our findings identify a melanocortinergic circuit that links acute elevations in hypothalamic temperature with acute reductions in food intake. PMID:29689050

Activation of temperature-sensitive TRPV1-like receptors in ARC POMC neurons reduces food intake.

PubMed

Jeong, Jae Hoon; Lee, Dong Kun; Liu, Shun-Mei; Chua, Streamson C; Schwartz, Gary J; Jo, Young-Hwan

2018-04-01

Proopiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus (ARC) respond to numerous hormonal and neural signals, resulting in changes in food intake. Here, we demonstrate that ARC POMC neurons express capsaicin-sensitive transient receptor potential vanilloid 1 receptor (TRPV1)-like receptors. To show expression of TRPV1-like receptors in ARC POMC neurons, we use single-cell reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry, electrophysiology, TRPV1 knock-out (KO), and TRPV1-Cre knock-in mice. A small elevation of temperature in the physiological range is enough to depolarize ARC POMC neurons. This depolarization is blocked by the TRPV1 receptor antagonist and by Trpv1 gene knockdown. Capsaicin-induced activation reduces food intake that is abolished by a melanocortin receptor antagonist. To selectively stimulate TRPV1-like receptor-expressing ARC POMC neurons in the ARC, we generate an adeno-associated virus serotype 5 (AAV5) carrying a Cre-dependent channelrhodopsin-2 (ChR2)-enhanced yellow fluorescent protein (eYFP) expression cassette under the control of the two neuronal POMC enhancers (nPEs). Optogenetic stimulation of TRPV1-like receptor-expressing POMC neurons decreases food intake. Hypothalamic temperature is rapidly elevated and reaches to approximately 39 °C during treadmill running. This elevation is associated with a reduction in food intake. Knockdown of the Trpv1 gene exclusively in ARC POMC neurons blocks the feeding inhibition produced by increased hypothalamic temperature. Taken together, our findings identify a melanocortinergic circuit that links acute elevations in hypothalamic temperature with acute reductions in food intake.

Tachykinins and tachykinin receptors in human uterus

PubMed Central

Patak, Eva; Luz Candenas, M; Pennefather, Jocelyn N; Ziccone, Sebastian; Lilley, Alison; Martín, Julio D; Flores, Carlos; Mantecón, Antonio G; Story, Margot E; Pinto, Francisco M

2003-01-01

Studies were undertaken to determine the nature of the receptors mediating contractile effects of tachykinins in the uteri of nonpregnant women, and to analyse the expression of preprotachykinins (PPT), tachykinin receptors and the cell-surface peptidase, neprilysin (NEP), in the myometrium from pregnant and nonpregnant women. The neurokinin B (NKB) precursor PPT-B was expressed in higher levels in the myometrium from nonpregnant than from pregnant women. Faint expression of PPT-A mRNA was detectable in the myometrium from nonpregnant but not pregnant women. PPT-C, the gene encoding the novel tachykinin peptide hemokinin-1 (HK-1), was present in trace amounts in the uteri from both pregnant and nonpregnant women. Tachykinin NK2 receptors were more strongly expressed in tissues from nonpregnant than from pregnant women. NK1 receptor mRNA was present in low levels in tissues from both pregnant and nonpregnant women. A low abundance transcript corresponding to the NK3 receptor was present only in tissues from nonpregnant women. The mRNA expression of the tachykinin-degrading enzyme NEP was lower in tissues from nonpregnant than from pregnant women. Substance P (SP), neurokinin A (NKA) and NKB, in the presence of the peptidase inhibitors thiorphan, captopril and bestatin, produced contractions of myometrium from nonpregnant women. The order of potency was NKA≫SP≥NKB. The potency of NKA was unchanged in the absence of peptidase inhibitors. The tachykinin NK2 receptor-selective agonist [Lys5MeLeu9Nle10]NKA(4–l0) was approximately equipotent with NKA, but the tachykinin NK1 and NK3 receptor-selective agonists [Sar9Met(O2)11]SP and [MePhe7]NKB were ineffective in the myometrium from nonpregnant women. The uterotonic effects of [Lys5MeLeu9Nle10]NKA(4–10) were antagonized by the tachykinin NK2 receptor-selective antagonist SR48968. Neither atropine, nor phentolamine nor tetrodotoxin affected responses to [Lys5MeLeu9Nle10]NKA(4–10). These data are consistent with a role of tachykinins in the regulation of human uterine function, and reinforce the importance of NK2 receptors in the regulation of myometrial contraction. PMID:12788812

Airborne fine particulate matter causes murine bronchial hyperreactivity via MAPK pathway-mediated M3 muscarinic receptor upregulation.

PubMed

Wang, Rong; Xiao, Xue; Shen, Zhenxing; Cao, Lei; Cao, Yongxiao

2017-02-01

Regarding the human health effects, airborne fine particulate matter 2.5 (PM 2.5 ) is an important environmental risk factor. However, the underlying molecular mechanisms are largely unknown. The present study examined the hypothesis that PM 2.5 causes bronchial hyperreactivity by upregulated muscarinic receptors via the mitogen-activated protein kinase (MAPK) pathway. The isolated rat bronchi segments were cultured with different concentration of PM 2.5 for different time. The contractile response of the bronchi segments were recorded by a sensitive myograph. The mRNA and protein expression levels of M 3 muscarinic receptors were studied by quantitative real-time PCR and immunohistochemistry, respectively. The muscarinic receptors agonist, carbachol induced a remarkable contractile response on fresh and DMSO cultured bronchial segments. Compared with the fresh or DMSO culture groups, 1.0 µg/mL of PM 2.5 cultured for 24 h significantly enhanced muscarinic receptor-mediated contractile responses in bronchi with a markedly increased maximal contraction. In addition, the expression levels of mRNA and protein for M 3 muscarinic receptors in bronchi of PM 2.5 group were higher than that of fresh or DMSO culture groups. SB203580 (p38 inhibitor) and U0126 (MEK1/2 inhibitor) significantly inhibited the PM 2.5 -induced enhanced contraction and increased mRNA and protein expression of muscarinic receptors. However, JNK inhibitor SP600125 had no effect on PM 2.5 -induced muscarinic receptor upregulation and bronchial hyperreactivity. In conclusion, airborne PM 2.5 upregulates muscarinic receptors, which causes subsequently bronchial hyperreactivity shown as enhanced contractility in bronchi. This process may be mediated by p38 and MEK1/2 MAPK pathways. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 371-381, 2017. © 2016 Wiley Periodicals, Inc.

Alteration in contractile G-protein coupled receptor expression by moist snus and nicotine in rat cerebral arteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sandhu, Hardip, E-mail: sandhu.hardip@gmail.com; Xu Cangbao; Edvinsson, Lars

The cardiovascular risk for users of use of Swedish snus/American snuff (moist tobacco) has been debated for a long time. The present study was designed to examine the effects of water- or lipid-soluble (DMSO-soluble) snus and nicotine, the most important substance in tobacco, on the expression of vasocontractile G-protein coupled receptors (GPCR), such as endothelin ET{sub B}, serotonin 5-HT{sub 1B}, and thromboxane A{sub 2} TP receptors, in rat cerebral arteries. Studies show that these vasocontractile GPCR show alterations by lipid-soluble cigarette smoke particles via activation of mitogen-activated protein kinases (MAPK). However, the effects of moist tobacco on the expression ofmore » GPCR are less studied. Rat middle cerebral arteries were isolated and organ cultured in serum-free medium for 24 h in the presence of water-soluble snus (WSS), DMSO-soluble snus (DSS), or nicotine. The dose of snus and nicotine was kept at plasma level of snus users (25 ng nicotine/ml). A high dose (250 ng nicotine/ml) was also included due to the previous results showing alteration in the GPCR expression by nicotine at this concentration. Contractile responses to the ET{sub B} receptor agonist sarafotoxin 6c, 5-HT{sub 1B} receptor agonist 5-carboxamidotryptamine, and TP receptor agonist U46619 were investigated by a sensitive myograph. The expression of ET{sub B}, 5-HT{sub 1B}, and TP receptors was studied at mRNA and protein levels using quantitative real-time PCR and immunohistochemistry, respectively. Organ culture with WSS or DSS (25 ng nicotine/ml) lowered the 5-HT{sub 1B} receptor-mediated contraction. Furthermore, DSS shifted the TP receptor-mediated contraction curve left-wards with a stronger contraction. High dose of nicotine (250 ng nicotine/ml) increased the ET{sub B} receptor-mediated contraction. The combined 5-HT{sub 1B} and 5-HT{sub 2A} receptor-mediated contraction was increased, and both the 5-CT and TxA2 induced contractions were left-ward shifted by WSS, DSS, or nicotine (250 ng nicotine/ml). Only the DSS group showed that the increase of 5-HT{sub 1B} receptor-mediated contraction occurred at the transcriptional level, demonstrated by an increased mRNA expression for the receptor. Thus, snus and nicotine alter the GPCR expression in the cerebral arteries, which may be involved in cerebral vascular disease.« less

Interleukin 31 mediates MAP kinase and STAT1/3 activation in intestinal epithelial cells and its expression is upregulated in inflammatory bowel disease

PubMed Central

Dambacher, Julia; Beigel, Florian; Seiderer, Julia; Haller, Dirk; Göke, Burkhard; Auernhammer, Christoph J; Brand, Stephan

2007-01-01

Background/aim Interleukin 31 (IL31), primarily expressed in activated lymphocytes, signals through a heterodimeric receptor complex consisting of the IL31 receptor alpha (IL31Rα) and the oncostatin M receptor (OSMR). The aim of this study was to analyse IL31 receptor expression, signal transduction, and specific biological functions of this cytokine system in intestinal inflammation. Methods Expression studies were performed by RT‐PCR, quantitative PCR, western blotting, and immunohistochemistry. Signal transduction was analysed by western blotting. Cell proliferation was measured by MTS assays, cell migration by restitution assays. Results Colorectal cancer derived intestinal epithelial cell (IEC) lines express both IL31 receptor subunits, while their expression in unstimulated primary murine IEC was low. LPS and the proinflammatory cytokines TNF‐α, IL1β, IFN‐γ, and sodium butyrate stimulation increased IL31, IL31Rα, and OSMR mRNA expression, while IL31 itself enhanced IL8 expression in IEC. IL31 mediates ERK‐1/2, Akt, STAT1, and STAT3 activation in IEC resulting in enhanced IEC migration. However, at low cell density, IL31 had significant antiproliferative capacities (p<0.005). IL31 mRNA expression was not increased in the TNFΔARE mouse model of ileitis but in inflamed colonic lesions compared to non‐inflamed tissue in patients with Crohn's disease (CD; average 2.4‐fold increase) and in patients with ulcerative colitis (UC; average 2.6‐fold increase) and correlated with the IL‐8 expression in these lesions (r = 0.564 for CD; r = 0.650 for UC; total number of biopsies analysed: n = 88). Conclusion IEC express the functional IL31 receptor complex. IL31 modulates cell proliferation and migration suggesting a role in the regulation of intestinal barrier function particularly in intestinal inflammation. PMID:17449633

Involvement of the orphan nuclear estrogen receptor-related receptor α in osteoclast adhesion and transmigration

PubMed Central

Bonnelye, Edith; Saltel, Frédéric; Chabadel, Anne; Zirngibl, Ralph A; Aubin, Jane E; Jurdic, Pierre

2010-01-01

The orphan nuclear receptor, estrogen receptor-related receptor α (ERRα) is expressed in osteoblasts and osteoclasts (OCs) and has been proposed to be a modulator of estrogen signaling. To determine the role of ERRα in OC biology, we knocked down ERRα activity by transient transfection of an siRNA directed against ERRα in the RAW264.7 monocyte–macrophage cell line that differentiates into OCs in the presence of receptor activator of nuclear factor κB-ligands and macrophage colony-stimulating factor. In parallel, stable RAW cell lines expressing a dominant-negative form of ERRα and green fluorescent protein (RAW-GFP-ERRαΔAF2) were used. Expression of OC markers was assessed by real-time PCR, and adhesion and transmigration tests were performed. Actin cytoskeletal organization was visualized using confocal microscopy. We found that RAW264.7 cells expressing siRNA directed against ERRα and RAW-GFP-ERRαΔAF2 OCs displayed abnormal spreading, and decreased osteopontin and β3 integrin subunit expression compared with the corresponding control cells. Decreased adhesion and the absence of podosome belts concomitant with abnormal localization of c-src were also observed in RAW-GFP-ERRαΔAF2-derived OCs. In addition, RAW-GFP-ERRαΔAF2-derived OCs failed to transmigrate through osteoblast cell layers. Our data show that the impairment of ERRα function does not alter OC precursor proliferation and differentiation but does alter the adhesion/spreading and migration capacities of mature OCs. PMID:20841427

In vitro expressed GPCR inserted in polymersome membranes for ligand-binding studies.

PubMed

May, Sylvia; Andreasson-Ochsner, Mirjam; Fu, Zhikang; Low, Ying Xiu; Tan, Darren; de Hoog, Hans-Peter M; Ritz, Sandra; Nallani, Madhavan; Sinner, Eva-Kathrin

2013-01-07

The dopamine receptor D2 (DRD2), a G-protein coupled receptor is expressed into PBd(22)-PEO(13) and PMOXA(20)-PDMS(54)-PMOXA(20) block copolymer vesicles. The conformational integrity of the receptor is confirmed by antibody- and ligand-binding assays. Replacement of bound dopamine is demonstrated on surface-immobilized polymersomes, thus making this a promising platform for drug screening. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of arachidonic acid metabolites on CR1 expression by B-lymphocytes.

PubMed

Cook, J M; Guibert, F; Delebassee, S; Gualde, N

1989-01-01

The effect of arachidonic acid metabolites on the expression of the receptor for the C3b/C4b fragment of complement (CR1) by human B-lymphocytes was investigated. Kinetic experiments to determine CR1 expression over time indicated that the maximal receptor number occurred at 2 h, followed by a return to baseline values. Addition of 10(-4) M puromycin to the cells suggested that the increase was due to the expression of an intracellular pool and not de novo synthesis of new receptor molecules. B-lymphocytes were incubated with arachidonic acid, 15-hydroxyeicosatetraenoic acid, leukotrienes B4 or C4 or prostaglandin E2 (PGE2). The quantity of membrane antigenic binding sites was determined before and after incubation. The lipoxygenase metabolites did not alter CR1 numbers. In contrast, PGE2 significantly decreased (P less than 0.05) the quantity of CR1 expressed. In kinetic experiments, PGE2 blocked the maximal expression of CR1 seen at 2 h, indicating that it prevents the appearance of an intracellular pool of receptor. These results show that CR1 number on B-lymphocytes can be altered by at least one arachidonic acid metabolite. This may offer a partial explanation for the inhibitory effects of PGE2 on B-cell proliferation and immunoglobulin secretion since CR1 is implicated in B-lymphocyte differentiation and specific antibody response.

Rat nicotinic ACh receptor α7 and β2 subunits co-assemble to form functional heteromeric nicotinic receptor channels

PubMed Central

Khiroug, Serguei S; Harkness, Patricia C; Lamb, Patricia W; Sudweeks, Sterling N; Khiroug, Leonard; Millar, Neil S; Yakel, Jerrel L

2002-01-01

Rat hippocampal interneurons express diverse subtypes of functional nicotinic acetylcholine receptors (nAChRs), including α7-containing receptors that have properties unlike those expected for homomeric α7 nAChRs. We previously reported a strong correlation between expression of the α7 and of the β2 subunits in individual neurons. To explore whether co-assembly of the α7 and β2 subunits might occur, these subunits were co-expressed in Xenopus oocytes and the functional properties of heterologously expressed nAChRs were characterized by two-electrode voltage clamp. Co-expression of the β2 subunit, both wild-type and mutant forms, with the α7 subunit significantly slowed the rate of nAChR desensitization and altered the pharmacological properties. Whereas ACh, carbachol and choline were full or near-full agonists for homomeric α7 receptor channels, both carbachol and choline were only partial agonists in oocytes expressing both α7 and β2 subunits. In addition the EC50 values for all three agonists significantly increased when the β2 subunit was co-expressed with the α7 subunit. Co-expression with the β2 subunit did not result in any significant change in the current-voltage curve. Biochemical evidence for the co-assembly of the α7 and β2 subunits was obtained by co-immunoprecipitation of these subunits from transiently transfected human embryonic kidney (TSA201) cells. These data provide direct biophysical and molecular evidence that the nAChR α7 and β2 subunits co-assemble to form a functional heteromeric nAChR with functional and pharmacological properties different from those of homomeric α7 channels. This co-assembly may help to explain nAChR channel diversity in rat hippocampal interneurons, and perhaps in other areas of the nervous system. PMID:11956333

Cell-Free Expression, Purification, and Characterization of the Functional β2-Adrenergic Receptor for Multianalyte Detection of β-Agonists.

PubMed

Wang, Jian; Liu, Yuan; Zhang, Junhua; Han, Zhengzheng; Wang, Wei; Liu, Yang; Wei, Dong; Huang, Wei

2017-11-01

Large-scale expression of β 2 -adrenergic receptor (β 2 -AR) in functional form is necessary for establishment of receptor assays for detecting illegally abused β-adrenergic agonists (β-agonists). Cell-based heterologous expression systems have manycritical difficulties in synthesizing this membrane protein, such as low protein yields and aberrant folding. To overcome these challenges, the main objective of the present work was to synthesize large amounts of functional β 2 -AR in a cell-free system based on Escherichia coli extracts. A codon-optimized porcine β 2 -AR gene (codon adaptation index: 0.96) suitable for high expression in E. coli was synthesized and transcribed to the cell-free system, which contributed to increase the expression up to 1.1 mg/ml. After purification using Ni-affinity chromatography, the bioactivity of the purified receptor was measured by novel enzyme-linked receptor assays. It was determined that the relative affinities of the purified β 2 -AR for β-agonists in descending order were as follows: clenbuterol > salbutamol > ractopamine. Moreover, their IC 50 values were 45.99, 60.38, and 78.02 µg/liter, respectively. Although activity of the cell-free system was slightly lower than activity of systems based on insect and mammalian cells, this system should allow production of β 2 -AR in bulk amounts sufficient for the development of multianalyte screening methods for detecting β-agonist residues.

Expression and associations of TRAF1, BMI-1, ALDH1, and Lin28B in oral squamous cell carcinoma.

PubMed

Wu, Tian-Fu; Li, Yi-Cun; Ma, Si-Rui; Bing-Liu; Zhang, Wen-Feng; Sun, Zhi-Jun

2017-04-01

Tumor necrosis factor receptor-associated factor 1, an adaptor protein of tumor necrosis factor 2, is involved in classical nuclear factor (NF)-κB activation and lymphocyte recruitment. However, less is known about the expression and association of tumor necrosis factor receptor-associated factor 1 with cancer stem cell markers in oral squamous cell carcinoma. This study aimed to investigate the expression of tumor necrosis factor receptor-associated factor 1 and stem cell characteristic markers (lin28 homolog B, B cell-specific Moloney murine leukemia virus integration site 1, and aldehyde dehydrogenase 1) in oral squamous cell carcinoma and analyze their relations. Paraffin-embedded tissues of 78 oral squamous cell carcinomas, 39 normal oral mucosa, and 12 oral dysplasia tissues were employed in tissue microarrays, and the expression of tumor necrosis factor receptor-associated factor 1, B cell-specific Moloney murine leukemia virus integration site 1, aldehyde dehydrogenase 1, and lin28 homolog B was measured by immunohistostaining and digital pathological analysis. The expression of tumor necrosis factor receptor-associated factor 1 was higher in the oral squamous cell carcinoma group as compared with the expression in the oral mucosa (p < 0.01) and oral dysplasia (p < 0.001) groups. In addition, the expression of tumor necrosis factor receptor-associated factor 1 was associated with those of B cell-specific Moloney murine leukemia virus integration site 1, aldehyde dehydrogenase 1, and lin28 homolog B (p = 0.032, r 2  = 0.109; p < 0.0001, r 2  = 0.64; and p < 0.001, r 2  = 0.16) in oral squamous cell carcinoma. The patient survival rate was lower in the highly expressed tumor necrosis factor receptor-associated factor 1 group, although the difference was not significant. The clustering analysis showed that tumor necrosis factor receptor-associated factor 1 was most related to aldehyde dehydrogenase 1. These findings suggest that tumor necrosis factor receptor-associated factor 1 has potential direct/indirect regulations with the cancer stem cell markers in oral squamous cell carcinoma, which may help in further analysis of the cancer stem cell characteristics.

The expression of Fc and complement receptors in young, adult and aged mice.

PubMed Central

Vĕtvicka, V; Fornůsek, L; Zídková, J

1985-01-01

Age-dependent changes in the expression of Fc receptors (FcR) for different isotypes of immunoglobulins and receptors for C3b, C5b and C3bi fragments of complement on the membranes of peritoneal macrophages were studied with mice of different ages. An age-related increase in expression of Fc receptors for IgM, IgE, IgA, IgG2b and IgG3, and a decrease in the expression of Fc receptors for IgG1 was observed. The expression of FcR on macrophages of donors of different ages corresponded with Fc-receptor mediated phagocytosis. The highest number of C3b-binding macrophages was found in aged mice, in contrast to low numbers of C3bi-binding macrophages at this age. The percentage of C5b-binding macrophages was lowest in adult animals. We also observed effective inhibition of binding of the C3b component of complement by preincubation of macrophages with aggregated IgG and vice versa. These observations suggest that fluctuation in expression of Fc but not C receptors may be important to the generalized changes that occur in macrophage function during development and ageing. PMID:2931351

Correlation between VEGFR-2 receptor kinase domain-containing receptor (KDR) mRNA and angiotensin II receptor type 1 (AT1-R) mRNA in endometrial cancer.

PubMed

Piastowska-Ciesielska, Agnieszka W; Płuciennik, Elżbieta; Wójcik-Krowiranda, Katarzyna; Bieńkiewicz, Andrzej; Nowakowska, Magdalena; Pospiech, Karolina; Bednarek, Andrzej K; Domińska, Kamila; Ochędalski, Tomasz

2013-02-01

Angiogenesis, a multistep process that results in new blood vessel formation from preexisting vasculature is essential for both the growth of solid tumour and for metastasis. Stimulation of vascular endothelial growth factor receptor (VEGFR), a transmembrane glycoprotein, results in mitogenesis. Within this family of receptors, VEGFR 2/kinase-insert-domain containing receptor appears to be principally upregulated during tumorigenesis. The aim of this study was to determine the expression of VEGFR-2/kinase-insert-domain containing receptor (KDR) and its correlation with angiotensin receptor type 1 (AT1-R) and clinical factors in endometrial carcinoma. The expression of KDR and AT1-R was studied in endometrial carcinoma and normal endometrium by Real-time RT-PCR and Western blot analysis in 136 samples. The expression profile was correlated with the clinicopathological characteristics of endometrial adenocarcinoma. We noted a significant correlation between the expression of KDR and AT1-R in tumour grade G1, G2 and G3 (R(s)=0.50; p=0.002, R(s)=0.69; p=0.0001, R(s)=0.52; p=0.005, respectively). In stage I and stage II carcinoma, a significant correlation was also found between the expression of KDR and AT1-R (R(s)=0.70, p=0.0001, R(s)=0.67; p=0.001, respectively). Moreover significant correlation was observed between both KDR and AT1-R in tissue with different myometrial invasion (R(s)=0.54, p=0.0001, R(s)=0.68; p=0.0001; respectively for tumours with invasion into the inner half and invasion into the outer half). Basing on received correlation between AT1-R and KDR expression and previous results we speculate that angiotensin through AT1-R modulates KDR expression and thus have influence on local VEGF level. However, further studies are required to clarify the biological interaction between KDR, AT1-R and other hormonal regulators in endometrial carcinoma. Copyright © 2012 Elsevier Ltd. All rights reserved.

Expression of sulfonylurea receptors in rat taste buds.

PubMed

Liu, Dian-Xin; Liu, Xiao-Min; Zhou, Li-Hong; Feng, Xiao-Hong; Zhang, Xiao-Juan

2011-07-01

To test the possibility that a fast-onset promoting agent repaglinide may initiate prandial insulin secretion through the mechanism of cephalic-phase insulin release, we explored the expression and distribution character of sulfonylurea receptors in rat taste buds. Twenty male Wistar rats aged 10 weeks old were killed after general anesthesia. The circumvallate papillae, fungiform papillae and pancreas tissues were separately collected. Immunohistochemical staining was used to detect the expression and distribution of sulfonylurea receptor 1 (SUR1) or sulfonylurea receptor 2 (SUR2) in rat taste buds. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to analyze the expression of SUR1 or SUR2 mRNA. The pancreatic tissues from the same rat were used as positive control. This is the first study to report that SUR1 is uniquely expressed in the taste buds of fungiform papillae of each rat tongue, while the expression of SUR1 or SUR2 was not detected in the taste buds of circumvallate papillae. SUR1 is selectively expressed in rat taste buds, and its distribution pattern may be functionally relevant, suggesting that the rapid insulin secretion-promoting effect of repaglinide may be exerted through the cephalic-phase secretion pathway mediated by taste buds. Copyright © 2010 Elsevier GmbH. All rights reserved.

A Viral Receptor Complementation Strategy to Overcome CAV-2 Tropism for Efficient Retrograde Targeting of Neurons.

PubMed

Li, Shu-Jing; Vaughan, Alexander; Sturgill, James Fitzhugh; Kepecs, Adam

2018-06-06

Retrogradely transported neurotropic viruses enable genetic access to neurons based on their long-range projections and have become indispensable tools for linking neural connectivity with function. A major limitation of viral techniques is that they rely on cell-type-specific molecules for uptake and transport. Consequently, viruses fail to infect variable subsets of neurons depending on the complement of surface receptors expressed (viral tropism). We report a receptor complementation strategy to overcome this by potentiating neurons for the infection of the virus of interest-in this case, canine adenovirus type-2 (CAV-2). We designed AAV vectors for expressing the coxsackievirus and adenovirus receptor (CAR) throughout candidate projection neurons. CAR expression greatly increased retrograde-labeling rates, which we demonstrate for several long-range projections, including some resistant to other retrograde-labeling techniques. Our results demonstrate a receptor complementation strategy to abrogate endogenous viral tropism and thereby facilitate efficient retrograde targeting for functional analysis of neural circuits. Copyright © 2018 Elsevier Inc. All rights reserved.

Hepatic Stellate Cells Express Functional CXCR4: Role in Stromal Cell–Derived Factor-1α–Mediated Stellate Cell Activation

PubMed Central

Hong, Feng; Tuyama, Ana; Lee, Ting Fang; Loke, Johnny; Agarwal, Ritu; Cheng, Xin; Garg, Anita; Fiel, M. Isabel; Schwartz, Myron; Walewski, Jose; Branch, Andrea; Schecter, Alison D.; Bansal, Meena B.

2010-01-01

Chemokine interactions with their receptors have been implicated in hepatic stellate cell (HSC) activation. The hepatic expression of CXCR4 messenger RNA is increased in hepatitis C cirrhotic livers and plasma levels of its endogenous ligand, stromal cell–derived factor-1α (SDF-1α), correlate with increased fibrosis in these patients. The expression of CXCR4 by HSCs has not been reported. We therefore examined whether HSCs express CXCR4 in vivo and in vitro and explored whether SDF-1α/CXCR4 receptor engagement promotes HSC activation, fibrogenesis, and proliferation. The hepatic protein expression of both CXCR4 and SDF-1α is increased in hepatitis C cirrhotic livers and immunoflourescent and immunohistochemical staining confirms that HSCs express CXCR4 in vivo. Immortalized human stellate cells as well as primary human HSCs express CXCR4, and cell surface receptor expression increases with progressive culture-induced activation. Treatment of stellate cells with recombinant SDF-1α increases expression of α-smooth muscle actin and collagen I and stimulates a dose-dependent increase in HSC proliferation. Inhibitor studies suggest that SDF-1α/CXCR4-dependent extracellular signal-regulated kinase 1/2 and Akt phosphorylation mediate effects on collagen I expression and stellate cell proliferation. Conclusion HSCs express CXCR4 receptor in vivo and in vitro. CXCR4 receptor activation by SDF-1α is profibrogenic through its effects on HSC activation, fibrogenesis, and proliferation. Extracellular signal-regulated kinase 1/2 and phosphoinositide 3-kinase pathways mediate SDF-1α–induced effects on HSC expression of collagen I and proliferation. The availability of small molecule inhibitors of CXCR4 make this receptor an appealing target for antifibrotic approaches. PMID:19434726

Differences in 5-HT2A and mGlu2 Receptor Expression Levels and Repressive Epigenetic Modifications at the 5-HT2A Promoter Region in the Roman Low- (RLA-I) and High- (RHA-I) Avoidance Rat Strains.

PubMed

Fomsgaard, Luna; Moreno, Jose L; de la Fuente Revenga, Mario; Brudek, Tomasz; Adamsen, Dea; Rio-Alamos, Cristobal; Saunders, Justin; Klein, Anders Bue; Oliveras, Ignasi; Cañete, Toni; Blazquez, Gloria; Tobeña, Adolf; Fernandez-Teruel, Albert; Gonzalez-Maeso, Javier; Aznar, Susana

2018-03-01

The serotonin 2A (5-HT 2A ) and metabotropic glutamate 2 (mGlu2) receptors regulate each other and are associated with schizophrenia. The Roman high- (RHA-I) and the Roman low- (RLA-I) avoidance rat strains present well-differentiated behavioral profiles, with the RHA-I strain emerging as a putative genetic rat model of schizophrenia-related features. The RHA-I strain shows increased 5-HT 2A and decreased mGlu2 receptor binding levels in prefrontal cortex (PFC). Here, we looked for differences in gene expression and transcriptional regulation of these receptors. The striatum (STR) was included in the analysis. 5-HT 2A , 5-HT 1A , and mGlu2 mRNA and [ 3 H]ketanserin binding levels were measured in brain homogenates. As expected, 5-HT 2A binding was significantly increased in PFC in the RHA-I rats, while no difference in binding was observed in STR. Surprisingly, 5-HT 2A gene expression was unchanged in PFC but significantly decreased in STR. mGlu2 receptor gene expression was significantly decreased in both PFC and STR. No differences were observed for the 5-HT 1A receptor. Chromatin immunoprecipitation assay revealed increased trimethylation of histone 3 at lysine 27 (H3K27me3) at the promoter region of the HTR2A gene in the STR. We further looked at the Akt/GSK3 signaling pathway, a downstream point of convergence of the serotonin and glutamate system, and found increased phosphorylation levels of GSK3β at tyrosine 216 and increased β-catenin levels in the PFC of the RHA-I rats. These results reveal region-specific regulation of the 5-HT 2A receptor in the RHA-I rats probably due to absence of mGlu2 receptor that may result in differential regulation of downstream pathways.

Dynamic changes in prefrontal cortex gene expression following lysergic acid diethylamide administration.

PubMed

Nichols, Charles D; Garcia, Efrain E; Sanders-Bush, Elaine

2003-03-17

Lysergic acid diethylamide (LSD) is a psychoactive drug that transiently alters human perception, behavior, and mood at extremely low doses. Certain aspects of the behavior elicited by acute doses of LSD closely resemble symptoms of mental disorders such as schizophrenia. Characterizing gene expression profiles after LSD will be important for understanding how it alters behavior, and will lead to novel insights into disorders, such as schizophrenia, whose behavioral symptoms resemble the temporary effects of hallucinogenic drugs. We previously identified a small collection of genes within the rat prefrontal cortex that respond to LSD. Many of the products of these genes are involved in the process of synaptic plasticity. In the current report, we present a detailed analysis of the expression of these genes within the brain using RNase protection analysis. We find that the gene response to LSD is quite dynamic. The expression of some genes increases rapidly and decreases rapidly, while other genes change more gradually. Dose-response studies show two classes of expression; gene expression maximally stimulated at lower doses, versus gene expression that continues to rise at the higher doses. The role of the 5-HT(1A) and 5-HT(2A) receptor in mediating the increases in gene expression was examined in a series of experiments using receptor specific antagonists. Most expression increases were due to activation of the 5-HT(2A) receptor, however expression of two genes had neither a 5-HT(1A) nor a 5-HT(2A) receptor component.

Mechanical stress-induced interleukin-1beta expression through adenosine triphosphate/P2X7 receptor activation in human periodontal ligament cells.

PubMed

Kanjanamekanant, K; Luckprom, P; Pavasant, P

2013-04-01

Mechanical stress is an important factor in maintaining homeostasis of the periodontium. Interleukin-1beta (IL-1β) and adenosine triphosphate (ATP) are considered potent inflammatory mediators. In macrophages, ATP-activated P2X7 receptor is involved in IL-1β processing and release. Our previous works demonstrated mechanical stress-induced expression of osteopontin and RANKL through the ATP/P2Y1 receptor in human periodontal ligament (HPDL) cells. This study was designed to examine the effect of mechanical stress on IL-1β expression in HPDL cells, as well as the mechanism and involvement of ATP and the P2 purinergic receptor. Cultured HPDL cells were treated with continuous compressive loading. IL-1β expression was analyzed at both mRNA and protein levels, using RT-PCR and ELISA, respectively. Cell viability was examined using the MTT assay. ATP was also used to stimulate HPDL cells. Inhibitors, antagonists and the small interfering RNA (siRNA) technique were used to investigate the role of ATP and the specific P2 subtypes responsible for IL-1β induction along with the intracellular mechanism. Mechanical stress could up-regulate IL-1β expression through the release of ATP in HPDL cells. ATP alone was also capable of increasing IL-1β expression. The induction of IL-1β was markedly inhibited by inhibitors and by siRNA targeting the P2X7 receptor. ATP-stimulated IL-1β expression was also diminished by intracellular calcium inhibitors. Our work clearly indicates the capability of HPDL cells to respond directly to mechanical stimulation. The results signified the important roles of ATP/P2 purinergic receptors, as well as intracellular calcium signaling, in mechanical stress-induced inflammation via up-regulation of the proinflammatory cytokine, IL-1β, in HPDL cells. © 2012 John Wiley & Sons A/S.

Cocaine-Induced Behavioral Sensitization Is Associated With Changes in the Expression of Endocannabinoid and Glutamatergic Signaling Systems in the Mouse Prefrontal Cortex

PubMed Central

Blanco, Eduardo; Pavón, Francisco J.; Palomino, Ana; Luque-Rojas, María Jesús; Serrano, Antonia; Rivera, Patricia; Bilbao, Ainhoa; Alen, Francisco; Vida, Margarita; Suárez, Juan

2015-01-01

Background: Endocannabinoids modulate the glutamatergic excitatory transmission by acting as retrograde messengers. A growing body of studies has reported that both signaling systems in the mesocorticolimbic neural circuitry are involved in the neurobiological mechanisms underlying drug addiction. Methods: We investigated whether the expression of both endocannabinoid and glutamatergic systems in the prefrontal cortex (PFC) were altered by an acute and/or repeated cocaine administration schedule that resulted in behavioral sensitization. We measured the protein and mRNA expression of the main endocannabinoid metabolic enzymes and the cannabinoid receptor type 1 (CB1). We also analyzed the mRNA expression of relevant components of the glutamate-signaling system, including glutamate-synthesizing enzymes, metabotropic receptors, and ionotropic receptors. Results: Although acute cocaine (10mg/kg) produced no significant changes in the endocannabinoid-related proteins, repeated cocaine administration (20mg/kg daily) induced a pronounced increase in the CB1 receptor expression. In addition, acute cocaine administration (10mg/kg) in cocaine-sensitized mice (referred to as cocaine priming) induced a selective increase in the endocannabinoid-degrading enzymes fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL). These protein changes were accompanied by an overall decrease in the ratios of endocannabinoid synthesis/degradation, especially the N-acyl phosphatidylethanolamine phospholipase D/FAAH and diacylglycerol lipase alpha/MAGL ratios. Regarding mRNA expression, while acute cocaine administration produced a decrease in CB1 receptors and N-acyl phosphatidylethanolamine phospholipase D, repeated cocaine treatment enhanced CB1 receptor expression. Cocaine-sensitized mice that were administered priming injections of cocaine mainly displayed an increased FAAH expression. These endocannabinoid changes were associated with modifications in glutamatergic transmission-related genes. An overall decrease was observed in the mRNA expression of the glutamate-synthesizing gene kidney-type glutaminase (KGA), the metabotropic glutamate receptors (mGluR3 and GluR), and subunits of NMDA ionotropic receptors (NR1, NR2A, NR2B and NR2C) after acute cocaine administration, while mice repeatedly exposed to cocaine only displayed an increase in NR2C. However, in cocaine-sensitized mice primed with cocaine, this inhibition was reversed and a strong increase was detected in the mGluR5, NR2 subunits, and both GluR1 and GluR3. Conclusions: These findings indicate that cocaine sensitization is associated with an endocannabinoid downregulation and a hyperglutamatergic state in the PFC that, overall, contribute to an enhanced glutamatergic input into PFC-projecting areas. PMID:25539508

Evaluation of the Pichia pastoris expression system for the production of GPCRs for structural analysis

PubMed Central

2011-01-01

Background Various protein expression systems, such as Escherichia coli (E. coli), Saccharomyces cerevisiae (S. cerevisiae), Pichia pastoris (P. pastoris), insect cells and mammalian cell lines, have been developed for the synthesis of G protein-coupled receptors (GPCRs) for structural studies. Recently, the crystal structures of four recombinant human GPCRs, namely β2 adrenergic receptor, adenosine A2a receptor, CXCR4 and dopamine D3 receptor, were successfully determined using an insect cell expression system. GPCRs expressed in insect cells are believed to undergo mammalian-like posttranscriptional modifications and have similar functional properties than in mammals. Crystal structures of GPCRs have not yet been solved using yeast expression systems. In the present study, P. pastoris and insect cell expression systems for the human muscarinic acetylcholine receptor M2 subtype (CHRM2) were developed and the quantity and quality of CHRM2 synthesized by both expression systems were compared for the application in structural studies. Results The ideal conditions for the expression of CHRM2 in P. pastoris were 60 hr at 20°C in a buffer of pH 7.0. The specific activity of the expressed CHRM2 was 28.9 pmol/mg of membrane protein as determined by binding assays using [3H]-quinuclidinyl benzilate (QNB). Although the specific activity of the protein produced by P. pastoris was lower than that of Sf9 insect cells, CHRM2 yield in P. pastoris was 2-fold higher than in Sf9 insect cells because P. pastoris was cultured at high cell density. The dissociation constant (Kd) for QNB in P. pastoris was 101.14 ± 15.07 pM, which was similar to that in Sf9 insect cells (86.23 ± 8.57 pM). There were no differences in the binding affinity of CHRM2 for QNB between P. pastoris and Sf9 insect cells. Conclusion Compared to insect cells, P. pastoris is easier to handle, can be grown at lower cost, and can be expressed quicker at a large scale. Yeast, P. pastoris, and insect cells are all effective expression systems for GPCRs. The results of the present study strongly suggested that protein expression in P. pastoris can be applied to the structural and biochemical studies of GPCRs. PMID:21513509

Oestrogen receptor alpha in pulmonary hypertension.

PubMed

Wright, Audrey F; Ewart, Marie-Ann; Mair, Kirsty; Nilsen, Margaret; Dempsie, Yvonne; Loughlin, Lynn; Maclean, Margaret R

2015-05-01

Pulmonary arterial hypertension (PAH) occurs more frequently in women with mutations in bone morphogenetic protein receptor type 2 (BMPR2) and dysfunctional BMPR2 signalling underpinning heritable PAH. We have previously shown that serotonin can uncover a pulmonary hypertensive phenotype in BMPR2(+/-) mice and that oestrogen can increase serotinergic signalling in human pulmonary arterial smooth muscle cells (hPASMCs). Hence, here we wished to characterize the expression of oestrogen receptors (ERs) in male and female human pulmonary arteries and have examined the influence of oestrogen and serotonin on BMPR2 and ERα expression. By immunohistochemistry, we showed that ERα, ERβ, and G-protein-coupled receptors are expressed in human pulmonary arteries localizing mainly to the smooth muscle layer which also expresses the serotonin transporter (SERT). Protein expression of ERα protein was higher in female PAH patient hPASMCs compared with male and serotonin also increased the expression of ERα. 17β-estradiol induced proliferation of hPASMCs via ERα activation and this engaged mitogen-activated protein kinase and Akt signalling. Female mice over-expressing SERT (SERT(+) mice) develop PH and the ERα antagonist MPP attenuated the development of PH in normoxic and hypoxic female SERT(+) mice. The therapeutic effects of MPP were accompanied by increased expression of BMPR2 in mouse lung. ERα is highly expressed in female hPASMCs from PAH patients and mediates oestrogen-induced proliferation of hPASMCs via mitogen-activated protein kinase and Akt signalling. Serotonin can increase ERα expression in hPASMCs and antagonism of ERα reverses serotonin-dependent PH in the mouse and increases BMPR2 expression. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Effects of Alpha-Lipoic Acid on Oxidative Stress and Kinin Receptor Expression in Obese Zucker Diabetic Fatty Rats.

PubMed

Midaoui, Adil El; Talbot, Sébastien; Lahjouji, Karim; Dias, Jenny Pena; Fantus, I George; Couture, Réjean

2015-06-01

To investigate the impact of alpha-lipoic acid on superoxide anion production and NADPH oxidase activity as well as on the expression of kinin B1 and B2 receptors in key organs of obese Zucker Diabetic Fatty rats. Superoxide anion production was measured by lucigenin chemiluminescence. Kinin B1 and B2 receptors expression was measured at protein and mRNA levels by western blot and qRT-PCR in key organs of Zucker Diabetic Fatty and Zucker lean control rats treated for a period of 6 weeks with a standard diet or a diet containing the antioxidant α-lipoic acid (1 g/kg). Superoxide anion production and NADPH oxidase activity were significantly enhanced in aorta and adipose tissue of Zucker Diabetic Fatty rats. Kinin B1 and B2 receptors expression levels were also significantly increased in the liver and the gastrocnemius muscle of Zucker Diabetic Fatty rats. Expression of both receptors was not altered in the pancreas of Zucker Diabetic Fatty rats and was undetectable in white retroperitoneal adipose tissue. Alpha-lipoic acid prevented the rise in NADPH oxidase activity in aorta and epididymal adipose tissue of Zucker Diabetic Fatty rats and the upregulation of kinin B1 receptor in liver and gastrocnemius muscle and that of kinin B2 receptor in the liver. Alpha-lipoic acid treatment was found to prevent the final body weight increase without affecting significantly hyperglycemia, hyperinsulinemia and insulin resistance index in Zucker Diabetic Fatty rats. Findings support the hypothesis that oxidative stress is implicated in the induction of kinin B1 receptor in Zucker Diabetic Fatty rats. The ability of α-lipoic acid to blunt the body weight gain appears to be mediated in part by preventing NADPH oxidase activity rise in adipose tissue and reversing the hepatic upregulation of kinin B1 receptor in Zucker Diabetic Fatty rats.

β-Carotene-9′,10′-Oxygenase Status Modulates the Impact of Dietary Tomato and Lycopene on Hepatic Nuclear Receptor–, Stress-, and Metabolism-Related Gene Expression in Mice123

PubMed Central

Tan, Hsueh-Li; Moran, Nancy E.; Cichon, Morgan J.; Riedl, Ken M.; Schwartz, Steven J.; Erdman, John W.; Pearl, Dennis K.; Thomas-Ahner, Jennifer M.; Clinton, Steven K.

2014-01-01

Tomato and lycopene (ψ, ψ-carotene) consumption is hypothesized to protect against nonalcoholic steatohepatitis and hepatocarcinogenesis, processes that may depend upon diet and gene interactions. To investigate the interaction of tomato or lycopene feeding with β-carotene-9′,10′-monooxygenase (Bco2) on hepatic metabolic and signaling pathways, male wild-type (WT) and Bco2−/− mice (3-wk-old; n = 36) were fed semi-purified control, 10% tomato powder–containing, or 0.25% lycopene beadlet–containing diets for 3 wk. Serum lycopene concentrations were higher in lycopene- and tomato-fed Bco2−/− mice compared with WT (P = 0.03). Tomato- and lycopene-fed mice had detectable hepatic apolipoprotein (apo)-6′-, apo-8′-, and apo-12′-lycopenal concentrations. Hepatic expression of β-carotene-15,15’-monooxygenase was increased in Bco2−/− mice compared with WT (P = 0.02), but not affected by diet. Evaluation of hepatic gene expression by focused quantitative reverse transcriptase-polymerase chain reaction arrays for nuclear receptors and coregulators (84 genes) and stress and metabolism (82 genes) genes indicates that tomato feeding affected 31 genes (≥1.5-fold, P < 0.05) and lycopene feeding affected 19 genes, 16 of which were affected by both diets. Lycopene down-regulation of 7 nuclear receptors and coregulators, estrogen-related receptor-α, histone deacetylase 3, nuclear receptor coactivator 4, RevErbA-β, glucocorticoid receptor, peroxisome proliferator-activated receptor (PPAR)-α, and PPAR-γ, coactivator 1 β was dependent upon interaction with Bco2 status. Lycopene and tomato feeding induced gene expression patterns consistent with decreased lipid uptake, decreased cell proliferation and mitosis, down-regulated aryl hydrocarbon receptor signaling, and decreased expression of genes involved in retinoid X receptor heterodimer activation. Tomato feeding also caused expression changes consistent with down-regulation of DNA synthesis and terpenoid metabolism. These data suggest tomato components, particularly lycopene, affect hepatic gene expression, potentially affecting hepatic responses to metabolic, infectious, or chemical stress. PMID:24553694

SH2 domains of the p85 alpha subunit of phosphatidylinositol 3-kinase regulate binding to growth factor receptors.

PubMed Central

McGlade, C J; Ellis, C; Reedijk, M; Anderson, D; Mbamalu, G; Reith, A D; Panayotou, G; End, P; Bernstein, A; Kazlauskas, A

1992-01-01

The binding of cytoplasmic signaling proteins such as phospholipase C-gamma 1 and Ras GTPase-activating protein to autophosphorylated growth factor receptors is directed by their noncatalytic Src homology region 2 (SH2) domains. The p85 alpha regulatory subunit of phosphatidylinositol (PI) 3-kinase, which associates with several receptor protein-tyrosine kinases, also contains two SH2 domains. Both p85 alpha SH2 domains, when expressed individually as fusion proteins in bacteria, bound stably to the activated beta receptor for platelet-derived growth factor (PDGF). Complex formation required PDGF stimulation and was dependent on receptor tyrosine kinase activity. The bacterial p85 alpha SH2 domains recognized activated beta PDGF receptor which had been immobilized on a filter, indicating that SH2 domains contact autophosphorylated receptors directly. Several receptor tyrosine kinases within the PDGF receptor subfamily, including the colony-stimulating factor 1 receptor and the Steel factor receptor (Kit), also associate with PI 3-kinase in vivo. Bacterially expressed SH2 domains derived from the p85 alpha subunit of PI 3-kinase bound in vitro to the activated colony-stimulating factor 1 receptor and to Kit. We infer that the SH2 domains of p85 alpha bind to high-affinity sites on these receptors, whose creation is dependent on receptor autophosphorylation. The SH2 domains of p85 are therefore primarily responsible for the binding of PI 3-kinase to activated growth factor receptors. Images PMID:1372092

Electrophysiological characterization of recombinant and native P2X receptors.

PubMed

Niforatos, Wende; Jarvis, Michael F

2004-10-01

ATP acts as a fast neurotransmitter by activating a family of ligand-gated ion channels, the P2X receptors. Functional homomeric P2X(3) and heteromeric P2X(2/3) receptors are highly localized on primary sensory afferent neurons that transmit nociceptive sensory information. Activation of these P2X(3)-containing channels may provide a specific mechanism whereby ATP, released via synaptic transmission or by cellular injury, elicits pain. The experimental procedures described in this unit are useful for the electorphysiological characterization of P2X receptors. In addition, these protocols provide methods for the evaluation of ligands that interact with P2X receptors that are either natively expressed on excitable cells or cloned and expressed in heterologous cell systems. These methods are derived from standard electrophysiological principles and procedures that are applicable to a wide variety of ligand-gated ion channels. Specific attention is given here to the reliable electrophysiological measurement of both quickly (P2X(3)) and more slowly (P2X(2) and P2X(2/3)) desensitizing receptors.

5-hydroxytryptamine level and 5-HT2A receptor mRNA expression in the guinea pigs eyes with spectacle lens-induced myopia

PubMed Central

Yang, Ji-Wen; Xu, Yan-Chun; Sun, Lin; Tian, Xiao-Dan

2010-01-01

AIM To investigate 5-hydroxytryptamine (5-HT) function and 5-HT receptor 2A (5-HT2A) mRNA expression in the formation of lens-induced myopia (LIM). METHODS Lens-induced myopia construction method was applied to generate myopia on guinea pig right eye (LIM eye). RESULTS LIM eyes formed significant myopia with longer axial length. 5-HT level in retina, choroids and sclera from LIM eyes was significantly higher than that in control group. 5-HT2A mRNA expression was also significantly up-regulated. CONCLUSION Refraction lens could induce myopia in guinea pig and 5-HT may play an important role in the formation of myopia by binding with 5-HT2A receptor. PMID:22553578

Functional requirements for inhibitory signal transmission by the immunomodulatory receptor CD300a.

PubMed

DeBell, Karen E; Simhadri, Venkateswara R; Mariano, John L; Borrego, Francisco

2012-04-26

Activation signals can be negatively regulated by cell surface receptors bearing immunoreceptor tyrosine-based inhibitory motifs (ITIMs). CD300a, an ITIM bearing type I transmembrane protein, is expressed on many hematopoietic cells, including subsets of lymphocytes. We have taken two approaches to further define the mechanism by which CD300a acts as an inhibitor of immune cell receptor signaling. First, we have expressed in Jurkat T cells a chimeric receptor consisting of the extracellular domains of killer-cell immunoglobulin-like receptor (KIR)2DL2 fused to the transmembrane and cytoplasmic segments of CD300a (KIR-CD300a) to explore surrogate ligand-stimulated inhibition of superantigen stimulated T cell receptor (TCR) mediated cell signaling. We found that intact CD300a ITIMs were essential for inhibition and that the tyrosine phosphorylation of these ITIMs required the src tyrosine kinase Lck. Tyrosine phosphorylation of the CD300a ITIMs created docking sites for both src homology 2 domain containing protein tyrosine phosphatase (SHP)-1 and SHP-2. Suppression of SHP-1 and SHP-2 expression in KIR-CD300a Jurkat T cells with siRNA and the use of DT40 chicken B cell lines expressing CD300a and deficient in several phosphatases revealed that SHP-1, but not SHP-2 or the src homology 2 domain containing inositol 5' phosphatase SHIP, was utilized by CD300a for its inhibitory activity. These studies provide new insights into the function of CD300a in tuning T and B cell responses.

The Dopamine D2 Receptor Gene in Lamprey, Its Expression in the Striatum and Cellular Effects of D2 Receptor Activation

PubMed Central

Robertson, Brita; Huerta-Ocampo, Icnelia; Ericsson, Jesper; Stephenson-Jones, Marcus; Pérez-Fernández, Juan; Bolam, J. Paul; Diaz-Heijtz, Rochellys; Grillner, Sten

2012-01-01

All basal ganglia subnuclei have recently been identified in lampreys, the phylogenetically oldest group of vertebrates. Furthermore, the interconnectivity of these nuclei is similar to mammals and tyrosine hydroxylase-positive (dopaminergic) fibers have been detected within the input layer, the striatum. Striatal processing is critically dependent on the interplay with the dopamine system, and we explore here whether D2 receptors are expressed in the lamprey striatum and their potential role. We have identified a cDNA encoding the dopamine D2 receptor from the lamprey brain and the deduced protein sequence showed close phylogenetic relationship with other vertebrate D2 receptors, and an almost 100% identity within the transmembrane domains containing the amino acids essential for dopamine binding. There was a strong and distinct expression of D2 receptor mRNA in a subpopulation of striatal neurons, and in the same region tyrosine hydroxylase-immunoreactive synaptic terminals were identified at the ultrastructural level. The synaptic incidence of tyrosine hydroxylase-immunoreactive boutons was highest in a region ventrolateral to the compact layer of striatal neurons, a region where most striatal dendrites arborise. Application of a D2 receptor agonist modulates striatal neurons by causing a reduced spike discharge and a diminished post-inhibitory rebound. We conclude that the D2 receptor gene had already evolved in the earliest group of vertebrates, cyclostomes, when they diverged from the main vertebrate line of evolution (560 mya), and that it is expressed in striatum where it exerts similar cellular effects to that in other vertebrates. These results together with our previous published data (Stephenson-Jones et al. 2011, 2012) further emphasize the high degree of conservation of the basal ganglia, also with regard to the indirect loop, and its role as a basic mechanism for action selection in all vertebrates. PMID:22563388

ANALYSIS OF ANDROGEN- AND EGF-RECEPTOR EXPRESSION IN THE FETAL RAT PHALLUS AFTER EXPOSURE TO VINCLOZOLIN

EPA Science Inventory

Analysis of Androgen- and EGF-Receptor Expression in the Fetal Rat Phallus After Exposure to Vinclozolin
Cynthia Wolf1,2, Barbara Abbott1, Gerald A. LeBlanc2, and L. Earl Gray, Jr.1
1USEPA, ORD, NHEERL, RTD, RTP, NC 27711, 2NCSU, Environmental and Molecular Toxicology, Ral...

Alk2/ACVR1 and Alk3/BMPR1A Provide Essential Function for Bone Morphogenetic Protein-Induced Retinal Angiogenesis.

PubMed

Lee, Heon-Woo; Chong, Diana C; Ola, Roxana; Dunworth, William P; Meadows, Stryder; Ka, Jun; Kaartinen, Vesa M; Qyang, Yibing; Cleaver, Ondine; Bautch, Victoria L; Eichmann, Anne; Jin, Suk-Won

2017-04-01

Increasing evidence suggests that bone morphogenetic protein (BMP) signaling regulates angiogenesis. Here, we aimed to define the function of BMP receptors in regulating early postnatal angiogenesis by analysis of inducible, endothelial-specific deletion of the BMP receptor components Bmpr2 (BMP type 2 receptor), Alk1 (activin receptor-like kinase 1), Alk2 , and Alk3 in mouse retinal vessels. Expression analysis of several BMP ligands showed that proangiogenic BMP ligands are highly expressed in postnatal retinas. Consistently, BMP receptors are also strongly expressed in retina with a distinct pattern. To assess the function of BMP signaling in retinal angiogenesis, we first generated mice carrying an endothelial-specific inducible deletion of Bmpr2 . Postnatal deletion of Bmpr2 in endothelial cells substantially decreased the number of angiogenic sprouts at the vascular front and branch points behind the front, leading to attenuated radial expansion. To identify critical BMPR1s (BMP type 1 receptors) associated with BMPR2 in retinal angiogenesis, we generated endothelial-specific inducible deletion of 3 BMPR1s abundantly expressed in endothelial cells and analyzed the respective phenotypes. Among these, endothelial-specific deletion of either Alk2 / acvr1 or Alk3 / Bmpr1a caused a delay in radial expansion, reminiscent of vascular defects associated with postnatal endothelial-specific deletion of BMPR2, suggesting that ALK2/ACVR1 and ALK3/BMPR1A are likely to be the critical BMPR1s necessary for proangiogenic BMP signaling in retinal vessels. Our data identify BMP signaling mediated by coordination of ALK2/ACVR1, ALK3/BMPR1A, and BMPR2 as an essential proangiogenic cue for retinal vessels. © 2017 The Authors.

Role of a Ubiquitously Expressed Receptor in the Vertebrate Olfactory System

PubMed Central

DeMaria, Shannon; Berke, Allison P.; Van Name, Eric; Heravian, Anisa; Ferreira, Todd

2013-01-01

Odorant cues are recognized by receptors expressed on olfactory sensory neurons, the primary sensory neurons of the olfactory epithelium. Odorant receptors typically obey the “one receptor, one neuron” rule, in which the receptive field of the olfactory neuron is determined by the singular odorant receptor that it expresses. Odor-evoked receptor activity across the population of olfactory neurons is then interpreted by the brain to identify the molecular nature of the odorant stimulus. In the present study, we characterized the properties of a C family G-protein-coupled receptor that, unlike most other odorant receptors, is expressed in a large population of microvillous sensory neurons in the zebrafish olfactory epithelium and the mouse vomeronasal organ. We found that this receptor, OlfCc1 in zebrafish and its murine ortholog Vmn2r1, is a calcium-dependent, low-sensitivity receptor specific for the hydrophobic amino acids isoleucine, leucine, and valine. Loss-of-function experiments in zebrafish embryos demonstrate that OlfCc1 is required for olfactory responses to a diverse mixture of polar, nonpolar, acidic, and basic amino acids. OlfCc1 was also found to promote localization of other OlfC receptor family members to the plasma membrane in heterologous cells. Together, these results suggest that the broadly expressed OlfCc1 is required for amino acid detection by the olfactory system and suggest that it plays a role in the function and/or intracellular trafficking of other olfactory and vomeronasal receptors with which it is coexpressed. PMID:24048853

Protection against high-fat diet-induced obesity in Helz2-deficient male mice due to enhanced expression of hepatic leptin receptor.

PubMed

Yoshino, Satoshi; Satoh, Tetsurou; Yamada, Masanobu; Hashimoto, Koshi; Tomaru, Takuya; Katano-Toki, Akiko; Kakizaki, Satoru; Okada, Shuichi; Shimizu, Hiroyuki; Ozawa, Atsushi; Tuchiya, Takafumi; Ikota, Hayato; Nakazato, Yoichi; Mori, Munemasa; Matozaki, Takashi; Sasaki, Tsutomu; Kitamura, Tadahiro; Mori, Masatomo

2014-09-01

Obesity arises from impaired energy balance, which is centrally coordinated by leptin through activation of the long form of leptin receptor (Leprb). Obesity causes central leptin resistance. However, whether enhanced peripheral leptin sensitivity could overcome central leptin resistance remains obscure. A peripheral metabolic organ targeted by leptin is the liver, with low Leprb expression. We here show that mice fed a high-fat diet (HFD) and obese patients with hepatosteatosis exhibit increased expression of hepatic helicase with zinc finger 2, a transcriptional coactivator (Helz2), which functions as a transcriptional coregulator of several nuclear receptors, including peroxisome proliferator-activated receptor γ in vitro. To explore the physiological importance of Helz2, we generated Helz2-deficient mice and analyzed their metabolic phenotypes. Helz2-deficient mice showing hyperleptinemia associated with central leptin resistance were protected against HFD-induced obesity and had significantly up-regulated hepatic Leprb expression. Helz2 deficiency and adenovirus-mediated liver-specific exogenous Leprb overexpression in wild-type mice significantly stimulated hepatic AMP-activated protein kinase on HFD, whereas Helz2-deficient db/db mice lacking functional Leprb did not. Fatty acid-β oxidation was increased in Helz2-deficeint hepatocytes, and Helz2-deficient mice revealed increased oxygen consumption and decreased respiratory quotient in calorimetry analyses. The enhanced hepatic AMP-activated protein kinase energy-sensing pathway in Helz2-deficient mice ameliorated hyperlipidemia, hepatosteatosis, and insulin resistance by reducing lipogenic gene expression and stimulating lipid-burning gene expression in the liver. These findings together demonstrate that Helz2 deficiency ameliorates HFD-induced metabolic abnormalities by stimulating endogenous hepatic Leprb expression, despite central leptin resistance. Hepatic HELZ2 might be a novel target molecule for the treatment of obesity with hepatosteatosis.

Death Receptor Expression on Blasts in AML Is Associated with Unfavorable Prognosis.

PubMed

Schmohl, Joerg Uwe; Nuebling, Tina; Wild, Julia; Jung, Johannes; Kroell, Tanja; Kanz, Lothar; Salih, Helmut R; Schmetzer, Helga

2015-07-01

Tumor necrosis factor (TNF) receptor family members play a key role in the regulation of biological functions such as differentiation, proliferation and apoptosis of various cell types. We studied co-expression profiles of death receptors from the TNF family [TNF-related apoptosis-inducing ligand receptor (TRAILR) 1 to 3, TNF receptor 1 (TNFR1) and FAS receptor (FAS)] on peripheral blood blasts from 46 patients with acute myeloid leukemia (AML) at first diagnosis by flow cytometry and correlated the obtained specific fluorescence indices (SFI) with morphological, cytogenetic and clinical parameters. We found that the expression of TRAILR2 and R3 was significantly increased in unfavorable risk groups, according to the National Comprehensive Cancer Network. Additionally, cut-off analyses for TRAILR2 and TNFR1 showed significantly shorter overall survival, earlier disease onset, higher proportions of cases with unfavorable prognosis and higher probability of relapse when SFIs were above the established cut-off. We demonstrate that high co-expression of death receptors on blasts is an independent predictor of poor prognosis in AML. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Expression of CXCR-1 and CXCR-2 chemokine receptors on synovial neutrophils in inflammatory arthritides: does persistent or increasing expression of CXCR-2 contribute to the chronic inflammation or erosive changes?

PubMed

Pay, Salih; Musabak, Ugur; Simşek, Ismail; Pekel, Aysel; Erdem, Hakan; Dinç, Ayhan; Sengül, Ali

2006-12-01

To analyze the CXCR-1 and CXCR-2 chemokine receptor expression on peripheral blood neutrophils (PBN) and synovial fluid neutrophils (SFN) of patients with rheumatoid arthritis (RA) and Behçet's disease (BD) (characterized by erosive and non-erosive arthritis, respectively), and to compare them with those of patients with osteoarthritis (OA). We used flow cytometry to investigate the expression of CXCR-1 and CXCR-2 chemokine receptors on PBN and SFN of fifty-five (22 RA, 22 BD and 11 OA) age and sex-matched patients. In respect to chemokine receptor expression on neutrophils isolated from patients with RA, mean fluorescein intensity (MFI) of CXCR-1 chemokine receptors on PBN from active and inactive RA patients, and SFN from patients with RA were 151 (90-395), 129 (81-539) and 136 (64-220), respectively, and there were not statistically significant difference each other. But MFI of CXCR-2 chemokine receptors on SFN of patients with RA was 18 (10-32), and significantly higher than PBN of active and inactive RA patients (MFI: 10 (6-15) and 12 (7-16), P=0.002 and 0.037, respectively). In respect to chemokine receptor expression on neutrophils isolated from patients with BD, MFI of CXCR-1 chemokine receptors on PBN of active BD patients was 245 (97-844), and higher than PBN of active RA patients and SFN of BD patients (MFI: 151 (90-395) and 134 (61-231), P=0.047 and 0.017, respectively). MFI of CXCR-2 chemokine receptors on PBN of active and inactive BD patients, and SFN of patients BD were 10 (6-14), 10 (2-16), and 12 (8-24), respectively, there were not statistically significant difference each other. MFI of CXCR-1 chemokine receptors on SFN from patients with RA, BD, and OA were 136 (64-220), 134 (61-231), and 114 (60-180), respectively, and there was no difference between the study groups. MFI of CXCR-2 chemokine receptors on SFN of patients with RA was 18 (10-32), and higher than patients with BD and OA (MFI: 12 (8-24) and 11 (9-18), P=0.037 and 0.005, respectively), though there was no difference between last two groups. Our study points that CXCR-1 and CXCR-2 chemokine receptors of SFN may have diverse functions in the course of inflammatory arthritides. These results indicate that CXCR-2 chemokine receptor might play more critical role in long lasting accumulation of neutrophils within the synovial fluid of patients with RA.

Sex- and age-related differences in the chronic pressure-natriuresis relationship: role of the angiotensin type 2 receptor.

PubMed

Mirabito, Katrina M; Hilliard, Lucinda M; Kett, Michelle M; Brown, Russell D; Booth, Sean C; Widdop, Robert E; Moritz, Karen M; Evans, Roger G; Denton, Kate M

2014-10-15

Sex hormones regulate the renin-angiotensin system. For example, estrogen enhances expression of the angiotensin type 2 receptor. We hypothesized that activation of the angiotensin type 2 receptor shifts the chronic pressure-natriuresis relationship leftward in females compared with males and that this effect is lost with age. Mean arterial pressure was measured by radiotelemetry in adult (4 mo old) and aged (14 mo old) wild-type and angiotensin type 2 receptor knockout male and female mice. Chronic pressure-natriuresis curves were constructed while mice were maintained on a normal-salt (0.26%) diet and following 6 days of high salt (5.0%) diet. Mean arterial pressure was lower in adult wild-type females than males (88 ± 1 and 97 ± 1 mmHg, respectively), a difference that was maintained with age, but was absent in adult knockout mice. In wild-type females, the chronic pressure-natriuresis relationship was shifted leftward compared with knockout females, an effect that was lost with age. In males, the chronic pressure-natriuresis relationship was not influenced by angiotensin type 2 receptor deficiency. Compared with age-matched females, the chronic pressure-natriuresis relationships in male mice were shifted rightward. Renal expression of the angiotensin type 2 receptor was fourfold greater in adult wild-type females than males. With age, the angiotensin type 2 receptor-to-angiotensin type 1 receptor balance was reduced in females. Conversely, in males, angiotensin receptor expression did not vary significantly with age. In conclusion, the angiotensin type 2 receptor modulates the chronic pressure-natriuresis relationship in an age- and sex-dependent manner. Copyright © 2014 the American Physiological Society.

Rapid constitutive and ligand-activated endocytic trafficking of P2X receptor.

PubMed

Vacca, Fabrizio; Giustizieri, Michela; Ciotti, Maria Teresa; Mercuri, Nicola Biagio; Volonté, Cinzia

2009-05-01

P2X receptors mediate a variety of physiological actions, including smooth muscle contraction, neuro-endocrine secretion and synaptic transmission. Among P2X receptors, the P2X(3) subtype is expressed in sensory neurons of dorsal root- and trigeminal-ganglia, where it performs a well-recognized role in sensory and pain transmission. Recent evidence indicates that the strength of P2X(3)-mediated responses is modulated in vivo by altering the number of receptors at the plasma membrane. In the present study, we investigate the trafficking properties of P2X(3) receptor in transfected HEK293 cells and in primary cultures of dorsal root ganglion neurons, finding that P2X(3) receptor undergoes rapid constitutive and cholesterol-dependent endocytosis. We also show that endocytosis is accompanied by preferential targeting of the receptor to late endosomes/lysosomes, with subsequent degradation. Furthermore, we observe that at steady state the receptor localizes predominantly in lamp1-positive intracellular structures, with a minor fraction present at the plasma membrane. Finally, the level of functional receptor expressed on the cell surface is rapidly up-regulated in response to agonist stimulation, which also augments receptor endocytosis. The findings presented in this work underscore a very dynamic trafficking behavior of P2X(3) receptor and disclose a possible mechanism for the rapid modulation of ATP-mediated responses potentially relevant during physiological and pathological conditions.

SKCa Channels Blockage Increases the Expression of Adenosine A2A Receptor in Jurkat Human T Cells

PubMed Central

Regaya, Imed; Aidi-Knani, Sabrine; By, Youlet; Condo, Jocelyne; Gerolami, Victoria; Berge-Lefranc, Jean-Louis; Ben Hamida, Jeannette; Sabatier, Jean-Marc; Fenouillet, Emmanuel; Guieu, Régis

2013-01-01

Abstract Adenosine is a nucleoside displaying various biological effects via stimulation of four G-protein–coupled receptors, A1, A2A, A2B, and A3. Adenosine also modulates voltage-gated (Kv) and small conductance calcium-activated (SKCa) potassium channels. The effect of these potassium channels on the expression of adenosine receptors is poorly understood. We evaluated the action of BgK (a natural Kv channel blocker) and Lei-Dab7 (a synthetic SKCa channel blocker) on the expression of adenosine A2A receptors (A2AR) in Jurkat human T cells. We found that Lei-Dab7, but not BgK, increased the maximal binding value of the tritiated ligand ZM241385 to A2AR in a dose-dependent manner (+45% at 5 nM; +70% at 50 nM as compared to control). These results were further confirmed by Western blotting using a specific monoclonal antibody to human A2AR. The ligand affinity-related dissociation constant and A2AR mRNA amount were not significantly modified by either drug. We suggest that modulation of SKCa channels can influence membrane expression of A2AR and thus has a therapeutic potential. PMID:23593569

Colonic inflammation increases the contribution of muscarinic M2 receptors to carbachol-induced contraction of the rat colon.

PubMed

Jragh, Dina M; Khan, Islam; Oriowo, Mabayoje A

2011-01-01

Carbachol-induced contraction of the rat colon is impaired in rats with trinitrobenzene sulfonic acid (TNBS)-induced colitis. The main objective of this study was to examine the effect of colitis on the expression and function of muscarinic (M) receptor subtypes in the rat colon. Rats (n = 80) were treated with TNBS and used 5 days later for measurement of contractility, myeloperoxidase activity, histology and expression of muscarinic receptor isoforms using Western blot analysis. Carbachol produced concentration-dependent contractions of colonic segments from control (n = 40) and TNBS-treated (n = 40) rats with no significant difference in potency. However, the maximum response to carbachol was significantly reduced in colon segments of TNBS-treated rats. The selective muscarinic receptor antagonists 4-diphenylacetoxy-N-methyl piperidine (4-DAMP, M(3)), pirenzepine (M(1)) and methoctramine (M(2)) antagonized carbachol-induced contraction in control (9.1 ± 0.1, 6.7 ± 0.3 and 6.0 ± 0.1, respectively) and TNBS-treated rats (9.2 ± 0.2, 6.9 ± 0.2, 6.7 ± 0.2). The -logK(B) values in control rats are consistent with an action of carbachol on muscarinic M(3) receptors. There was no significant difference in -logK(B) values for 4-DAMP and pirenzepine in control and TNBS-treated rats, but methoctramine was fivefold more potent in TNBS-treated rats, possibly indicating an increased contribution of muscarinic M(2) receptors to carbachol-induced contraction in the inflamed colon. The expression of M(2) receptors was also significantly increased in colon segments from TNBS-treated rats, confirming the increased role of muscarinic M(2) receptors in the inflamed colon. The data show that while only M(3) receptors appeared to mediate carbachol-induced contraction in control segments, expression of both M(2) and M(3) receptors was increased in the inflamed rat colon. Copyright © 2011 S. Karger AG, Basel.

Opiate withdrawal induces dynamic expressions of AMPA receptors and its regulatory molecule CaMKIIalpha in hippocampal synapses.

PubMed

Zhong, Weixia; Dong, Zhifang; Tian, Meng; Cao, Jun; Xu, Tianle; Xu, Lin; Luo, Jianhong

2006-07-24

Adaptive changes in brain areas following drug withdrawal are believed to contribute to drug seeking and relapse. Cocaine withdrawal alters the expression of GluR1 and GluR2/3 subunits of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors in nucleus accumbens or amygdala, but the influence of drug withdrawal on hippocampus is little known. Here, we have examined the expression of GluR1 and GluR2/3 in hippocampal membrane and synaptic fractions following repeated morphine exposure and subsequent withdrawal. Repeated morphine exposure for 12 d increased GluR1 and GluR2/3 in synaptosome but not in membrane fraction. Interestingly, CaMKIIalpha, known to be able to regulate the function of AMPA receptors, was decreased in synaptosome but not in membrane fraction; pCaMKIIalpha, the phosphorylated form of CaMKIIalpha, was increased in both fractions. However, during opiate withdrawal, GluR1 was generally reduced while GluR2/3 was prominently increased in both fractions; pCaMKIIalpha was strongly decreased immediately after withdrawal, but detectably increased in late phase of morphine withdrawal in both fractions. Importantly, the opiate withdrawal-induced increase in GluR2/3 was dependent on the activation of glucocorticoid receptors and NMDA receptors, as it was prevented by the glucocorticoid receptor antagonist RU38486, or intrahippocampal injection of the NMDA receptor antagonist AP-5 or the antagonist to NR2B-containing NMDA receptors, Ro25-6981. These findings indicate that opiate withdrawal induces dynamic expression of GluR1 and GluR2/3 subunits of AMPA receptors in hippocampal synapses, possibly revealing an adaptive process of the hippocampal functions following opiate withdrawal.

Effects of the single and combined treatment with dopamine agonist, somatostatin analog and mTOR inhibitors in a human lung carcinoid cell line: an in vitro study.

PubMed

Pivonello, Claudia; Rousaki, Panagoula; Negri, Mariarosaria; Sarnataro, Maddalena; Napolitano, Maria; Marino, Federica Zito; Patalano, Roberta; De Martino, Maria Cristina; Sciammarella, Concetta; Faggiano, Antongiulio; Rocco, Gaetano; Franco, Renato; Kaltsas, Gregory A; Colao, Annamaria; Pivonello, Rosario

2017-06-01

Somatostatin analogues and mTOR inhibitors have been used as medical therapy in lung carcinoids with variable results. No data are available on dopamine agonists as treatment for lung carcinoids. The main aim of the current study was to evaluate the effect of the combined treatment of somatostatin analogue octreotide and the dopamine agonist cabergoline with mTOR inhibitors in an in vitro model of typical lung carcinoids: the NCI-H727 cell line. In NCI-H727 cell line, reverse transcriptase-quantitative polymerase chain reaction and immunofluorescence were assessed to characterize the expression of the somatostatin receptor 2 and 5, dopamine receptor 2 and mTOR pathway components. Fifteen typical lung carcinoids tissue samples have been used for somatostatin receptor 2, dopamine receptor 2, and the main mTOR pathway component p70S6K expression and localization by immunohistochemistry. Cell viability, fluorescence-activated cell sorting analysis and western blot have been assessed to test the pharmacological effects of octreotide, cabergoline and mTOR inhibitors, and to evaluate the activation of specific cell signaling pathways in NCI-H727 cell line. NCI-H727 cell line expressed somatostatin receptor 2, somatostatin receptor 5 and dopamine receptor 2 and all mTOR pathway components at messenger and protein levels. Somatostatin receptor 2, dopamine receptor 2, and p70S6K (non phosphorylated and phosphorylated) proteins were expressed in most typical lung carcinoids tissue samples. Octreotide and cabergoline did not reduce cell viability as single agents but, when combined with mTOR inhibitors, they potentiate mTOR inhibitors effect after long-term exposure, reducing Akt and ERK phosphorylation, mTOR escape mechanisms, and increasing the expression DNA-damage-inducible transcript 4, an mTOR suppressor. In conclusion, the single use of octreotide and cabergoline is not sufficient to block cell viability but the combined approach of these agents with mTOR inhibitors might reduce the mTOR inhibitors-induced escape mechanisms and/or activate the endogenous mTOR suppressor, potentiating the effect of the mTOR inhibitors in an in vitro model of typical lung carcinoids.

Neurotrophins Acting Via TRKB Receptors Activate the JAGGED1-NOTCH2 Cell-Cell Communication Pathway to Facilitate Early Ovarian Development

PubMed Central

Dorfman, Mauricio D.; Kerr, Bredford; Garcia-Rudaz, Cecilia; Paredes, Alfonso H.; Dissen, Gregory A.

2011-01-01

Tropomyosin-related kinase (TRK) receptor B (TRKB) mediates the supportive actions of neurotrophin 4/5 and brain-derived neurotrophic factor on early ovarian follicle development. Absence of TRKB receptors reduces granulosa cell (GC) proliferation and delays follicle growth. In the present study, we offer mechanistic insights into this phenomenon. DNA array and quantitative PCR analysis of ovaries from TrkB-null mice revealed that by the end of the first week of postnatal life, Jagged1, Hes1, and Hey2 mRNA abundance is reduced in the absence of TRKB receptors. Although Jagged1 encodes a NOTCH receptor ligand, Hes1 and Hey2 are downstream targets of the JAGGED1-NOTCH2 signaling system. Jagged1 is predominantly expressed in oocytes, and the abundance of JAGGED1 is decreased in TrkB−/− oocytes. Lack of TRKB receptors also resulted in reduced expression of c-Myc, a NOTCH target gene that promotes entry into the cell cycle, but did not alter the expression of genes encoding core regulators of cell-cycle progression. Selective restoration of JAGGED1 synthesis in oocytes of TrkB−/− ovaries via lentiviral-mediated transfer of the Jagged1 gene under the control of the growth differentiation factor 9 (Gdf9) promoter rescued c-Myc expression, GC proliferation, and follicle growth. These results suggest that neurotrophins acting via TRKB receptors facilitate early follicle growth by supporting a JAGGED1-NOTCH2 oocyte-to-GC communication pathway, which promotes GC proliferation via a c-MYC-dependent mechanism. PMID:22028443

Pathophysiological roles of P2 receptors in glial cells.

PubMed

Abbracchio, Maria P; Verderio, Claudia

2006-01-01

Extracellular nucleotides act through specific receptors on target cells: the seven ionotropic P2X and the eight G protein-coupled P2Y receptors. All these receptors are expressed by brain astroglia and microglia. In astrocytes, P2 receptors have been implicated in short-term calcium-dependent cell-cell communication. Upon mechanical stimulation or activation by other transmitters, astrocytes release ATP and respond to ATP with a propagating wave of intracellular calcium increases, allowing a homotypic astrocyte-astrocyte communication, as well as an heterotypic signalling which also involves neurons, oligodendrocytes and microglia. Astrocytic P2 receptors also mediate reactive astrogliosis, a reaction contributing to neuronal death in neurodegenerative diseases. Signalling leading to inflammatory astrogliosis involves induction of cyclo-oxygenase 2 through stimulation of ERK1,2 and of the transcriptional factors AP-1 and NF-kappaB. Microglia also express several P2 receptors linked to intracellular calcium increases. P2 receptor subtypes are differentially regulated by typical proinflammatory signals for these cells (e.g. lipopolysaccharide), suggesting specific roles in brain immune responses. Globally, these findings highlight the roles of P2 receptors in glial cell pathophysiology suggesting a contribution to neurodegenerative diseases characterized by excessive gliosis and neuro-inflammation. They also open up the possibility of modulating brain damage by ligands selectively targeting the specific P2 receptor subtypes involved in the gliotic response.

Functional expression of 5-HT{sub 2A} receptor in osteoblastic MC3T3-E1 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hirai, Takao; Kaneshige, Kota; Kurosaki, Teruko

2010-05-28

In the previous study, we reported the gene expression for proteins related to the function of 5-hydroxytryptamine (5-HT, serotonin) and elucidated the expression patterns of 5-HT{sub 2} receptor subtypes in mouse osteoblasts. In the present study, we evaluated the possible involvement of 5-HT receptor subtypes and its inactivation system in MC3T3-E1 cells, an osteoblast cell line. DOI, a 5-HT{sub 2A} and 5-HT{sub 2C} receptor selective agonist, as well as 5-HT concentration-dependently increased proliferative activities of MC3T3-E1 cells in their premature period. This effect of 5-HT on cell proliferation were inhibited by ketanserin, a 5-HT{sub 2A} receptor specific antagonist. Moreover, bothmore » DOI-induced cell proliferation and phosphorylation of ERK1 and 2 proteins were inhibited by PD98059 and U0126, selective inhibitors of MEK in a concentration-dependent manner. Furthermore, treatment with fluoxetine, a 5-HT specific re-uptake inhibitor which inactivate the function of extracellular 5-HT, significantly increased the proliferative activities of MC3T3-E1 cells in a concentration-dependent manner. Our data indicate that 5-HT fill the role for proliferation of osteoblast cells in their premature period. Notably, 5-HT{sub 2A} receptor may be functionally expressed to regulate mechanisms underlying osteoblast cell proliferation, at least in part, through activation of ERK/MAPK pathways in MC3T3-E1 cells.« less

Expression of NMDA receptor subunits in human blood lymphocytes: A peripheral biomarker in online computer game addiction.

PubMed

Sadat-Shirazi, Mitra-Sadat; Vousooghi, Nasim; Alizadeh, Bentolhoda; Makki, Seyed Mohammad; Zarei, Seyed Zeinolabedin; Nazari, Shahrzad; Zarrindast, Mohammad Reza

2018-05-23

Background and aims Repeated performance of some behaviors such as playing computer games could result in addiction. The NMDA receptor is critically involved in the development of behavioral and drug addictions. It has been claimed that the expression level of neurotransmitter receptors in the brain may be reflected in peripheral blood lymphocytes (PBLs). Methods Here, using a real-time PCR method, we have investigated the mRNA expression of GluN2A, GluN2D, GluN3A, and GluN3B subunits of the NMDA receptor in PBLs of male online computer game addicts (n = 25) in comparison with normal subjects (n = 26). Results Expression levels of GluN2A, GluN2D, and GluN3B subunits were not statistically different between game addicts and the control group. However, the mRNA expression of the GluN3A subunit was downregulated in PBLs of game addicts. Discussion and conclusions Transcriptional levels of GluN2A and GluN2D subunits in online computer game addicts are similar to our previously reported data of opioid addiction and are not different from the control group. However, unlike our earlier finding of drug addiction, the mRNA expression levels of GluN3A and GluN3B subunits in PBLs of game addicts are reduced and unchanged, respectively, compared with control subjects. It seems that the downregulated state of the GluN3A subunit of NMDA receptor in online computer game addicts is a finding that deserves more studies in the future to see whether it can serve as a peripheral biomarker in addiction studies, where the researcher wants to rule out the confusing effects of abused drugs.

SR 144528, the first potent and selective antagonist of the CB2 cannabinoid receptor.

PubMed

Rinaldi-Carmona, M; Barth, F; Millan, J; Derocq, J M; Casellas, P; Congy, C; Oustric, D; Sarran, M; Bouaboula, M; Calandra, B; Portier, M; Shire, D; Brelière, J C; Le Fur, G L

1998-02-01

Based on both binding and functional data, this study introduces SR 144528 as the first, highly potent, selective and orally active antagonist for the CB2 receptor. This compound which displays subnanomolar affinity (Ki = 0.6 nM) for both the rat spleen and cloned human CB2 receptors has a 700-fold lower affinity (Ki = 400 nM) for both the rat brain and cloned human CB1 receptors. Furthermore it shows no affinity for any of the more than 70 receptors, ion channels or enzymes investigated (IC50 > 10 microM). In vitro, SR 144528 antagonizes the inhibitory effects of the cannabinoid receptor agonist CP 55,940 on forskolin-stimulated adenylyl cyclase activity in cell lines permanently expressing the h CB2 receptor (EC50 = 10 nM) but not in cells expressing the h CB1 (no effect at 10 microM). Furthermore, SR 144528 is able to selectively block the mitogen-activated protein kinase activity induced by CP 55,940 in cell lines expressing h CB2 (IC50 = 39 nM) whereas in cells expressing h CB1 an IC50 value of more than 1 microM is found. In addition, SR 144528 is shown to antagonize the stimulating effects of CP 55,940 on human tonsillar B-cell activation evoked by cross-linking of surface Igs (IC50 = 20 nM). In vivo, after oral administration SR 144528 totally displaced the ex vivo [3H]-CP 55,940 binding to mouse spleen membranes (ED50 = 0.35 mg/kg) with a long duration of action. In contrast, after the oral route it does not interact with the cannabinoid receptor expressed in the mouse brain (CB1). It is expected that SR 144528 will provide a powerful tool to investigate the in vivo functions of the cannabinoid system in the immune response.

Effect of glial cell line-derived neurotrophic factor on behavior and key members of the brain serotonin system in mouse strains genetically predisposed to behavioral disorders.

PubMed

Naumenko, Vladimir S; Bazovkina, Daria V; Semenova, Alina A; Tsybko, Anton S; Il'chibaeva, Tatyana V; Kondaurova, Elena M; Popova, Nina K

2013-12-01

The effect of glial cell line-derived neurotrophic factor (GDNF) on behavior and on the serotonin (5-HT) system of a mouse strain predisposed to depressive-like behavior, ASC/Icg (Antidepressant Sensitive Cataleptics), in comparison with the parental "nondepressive" CBA/Lac mice was studied. Within 7 days after acute administration, GDNF (800 ng, i.c.v.) decreased cataleptic immobility but increased depressive-like behavioral traits in both investigated mouse strains and produced anxiolytic effects in ASC mice. The expression of the gene encoding the key enzyme for 5-HT biosynthesis in the brain, tryptophan hydroxylase-2 (Tph-2), and 5-HT1A receptor gene in the midbrain as well as 5-HT2A receptor gene in the frontal cortex were increased in GDNF-treated ASC mice. At the same time, GDNF decreased 5-HT1A and 5-HT2A receptor gene expression in the hippocampus of ASC mice. GDNF failed to change Tph2, 5-HT1A , or 5-HT2A receptor mRNA levels in CBA mice as well as 5-HT transporter gene expression and 5-HT1A and 5-HT2A receptor functional activity in both investigated mouse strains. The results show 1) a GDNF-induced increase in the expression of key genes of the brain 5-HT system, Tph2, 5-HT1A , and 5-HT2A receptors, and 2) significant genotype-dependent differences in the 5-HT system response to GDNF treatment. The data suggest that genetically defined cross-talk between neurotrophic factors and the brain 5-HT system underlies the variability in behavioral response to GDNF. Copyright © 2013 Wiley Periodicals, Inc.

Signal transduction and functional selectivity of F15599, a preferential post-synaptic 5-HT1A receptor agonist

PubMed Central

Newman-Tancredi, A; Martel, J-C; Assié, M-B; Buritova, J; Lauressergues, E; Cosi, C; Heusler, P; Slot, L Bruins; Colpaert, FC; Vacher, B; Cussac, D

2009-01-01

Background and purpose: Activation of post-synaptic 5-HT1A receptors may provide enhanced therapy against depression. We describe the signal transduction profile of F15599, a novel 5-HT1A receptor agonist. Experimental approach: F15599 was compared with a chemical congener, F13714, and with (+)8-OH-DPAT in models of signal transduction in vitro and ex vivo. Key results: F15599 was highly selective for 5-HT1A receptors in binding experiments and in [35S]-GTPγS autoradiography of rat brain, where F15599 increased labelling in regions expressing 5-HT1A receptors. In cell lines expressing h5-HT1A receptors, F15599 more potently stimulated extracellular signal-regulated kinase (ERK1/2) phosphorylation, compared with G-protein activation, internalization of h5-HT1A receptors or inhibition of cAMP accumulation. F13714, (+)8-OH-DPAT and 5-HT displayed a different rank order of potency for these responses. F15599 stimulated [35S]-GTPγS binding more potently in frontal cortex than raphe. F15599, unlike 5-HT, more potently and efficaciously stimulated Gαi than Gαo activation. In rat prefrontal cortex (a region expressing post-synaptic 5-HT1A receptors), F15599 potently activated ERK1/2 phosphorylation and strongly induced c-fos mRNA expression. In contrast, in raphe regions (expressing pre-synaptic 5-HT1A receptors) F15599 only weakly or did not induce c-fos mRNA expression. Finally, despite its more modest affinity in vitro, F15599 bound to 5-HT1A receptors in vivo almost as potently as F13714. Conclusions and implications: F15599 showed a distinctive activation profiles for 5-HT1A receptor-mediated signalling pathways, unlike those of reference agonists and consistent with functional selectivity at 5-HT1A receptors. In rat, F15599 potently activated signalling in prefrontal cortex, a feature likely to underlie its beneficial effects in models of depression and cognition. PMID:19154445

Decreased expression of G-protein coupled receptor kinase 2 in cold thyroid nodules.

PubMed

Voigt, C; Holzapfel, H-P; Paschke, R

2005-02-01

G-protein coupled receptor kinases (GRKs) have been shown to regulate the homologous desensitization of different G-protein coupled receptors. We have previously demonstrated that the expression of GRK 3 and 4 is increased in hyperfunctioning thyroid nodules (HTNs) and that GRKs 2, 3, 5 and 6 are able to desensitize the TSHR in vitro. Since cold thyroid nodules (CTNs) and HTNs show different molecular and functional properties, different expression patterns of GRKs in these nodules can be expected. The comparison of GRK expression between CTNs and HTNs could give additional insight into the regulation mechanisms of these nodules. We therefore examined the expression of GRKs in CTNs and analyzed the differences to HTNs. The expression of the different GRKs in CTNs was measured by Western blot followed by chemiluminescence imaging. We found a decreased expression of GRK 2 in CTNs compared to their surrounding tissues and an increased expression of GRK 3 and 4 in CTNs, which is similar to HTNs. The decreased GRK 2 expression most likely results from reduced cAMP stimulation in CTNs. However, the increased GRK 3 and 4 expression in CTNs remains unclear and requires further investigations.

Reduction in the mRNA expression of sVEGFR1 and sVEGFR2 is associated with the selection of dominant follicle in cows.

PubMed

Ortega Serrano, P V; Guzmán, A; Hernández-Coronado, C G; Castillo-Juárez, H; Rosales-Torres, A M

2016-12-01

The vascular endothelial growth factor (VEGF) is essential for follicular development by promoting follicular angiogenesis, as well as for the proliferation and survival of granulosa cells. The biological effects of VEGF are regulated by two membrane receptors, VEGFR1 and VEGFR2, and two soluble receptors, sVEGFR1 and sVEGFR2, which play an antagonistic role. Thus, the objective of this study was to identify the mRNA expression pattern of total VEGF, VEGFR1, VEGFR2, sVEGFR1 and sVEGFR2 in bovine preselected follicles (PRF) and post-selected follicles (POF). The mRNA expression of these five genes in both granulosa cells (GC) and theca cells (TC) was compared between follicles classified as PRF and POF based on their diameter and on their ratio of estradiol/progesterone (E2/P4). Results showed a lower expression of mRNA of sVEGFR1 and sVEGFR2 in POF than in PRF (p < .05). Regarding the mRNA expression of total VEGF, VEGFR1 and VEGFR2, there was no difference between POF and PRF follicles (p > .05). Our results showed that the mRNA expression of VEGFR2 and sVEGFR1 was more abundant than the expression of VEGFR1 and sVEGFR2, while GC was the main source of mRNA for total VEGF. On the other hand, TC was the follicular compartment where the receptors were most expressed. Our results suggest that non-dominant follicles maintain a greater concentration of the mRNA expression of both membrane and soluble VEGF receptors. On the other hand, follicular dominance is related to a reduction in the mRNA expression of sVEGFR1 and sVEGFR2, which may favour VEGF binding with VEGFR2 and, hence, improve the follicular health and development. © 2016 Blackwell Verlag GmbH.

Expression of adiponectin and its receptors in the porcine hypothalamus during the oestrous cycle.

PubMed

Kaminski, T; Smolinska, N; Maleszka, A; Kiezun, M; Dobrzyn, K; Czerwinska, J; Szeszko, K; Nitkiewicz, A

2014-06-01

Adiponectin is a hormonal link between obesity and reproduction, and its actions are mediated by two types of receptors: adiponectin receptor 1 (AdipoR1) and adiponectin receptor 2 (AdipoR2). This study compares the expression levels of adiponectin and adiponectin receptor mRNAs and proteins in selected areas of the porcine hypothalamus responsible for GnRH production and secretion: the mediobasal hypothalamus (MBH), pre-optic area (POA) and stalk median eminence (SME). The tissue samples were harvested on days 2-3, 10-12, 14-16 and 17-19 of the oestrous cycle. Adiponectin mRNA expression in MBH was significantly lower on days 14-16, whereas in SME, the most pronounced gene expression was found on days 2-3 of the cycle (p < 0.05). Adiponectin protein in MBH was most abundant on days 17-19 and in POA on days 2-3 (p < 0.05). Adiponectin protein expression in SME was at similar level throughout the most of the cycle with a statistically significant drop (p < 0.05) on days 14-16. AdipoR1 gene expression in POA was potentiated on days 2-3 and 10-12 of the oestrous cycle (p < 0.05). In SME, the highest AdipoR1 mRNA expression was noted on days 2-3 (p < 0.05). The concentrations of the AdipoR1 protein in POA were similar throughout the luteal phase (days 2-14 of the cycle), and they decreased on days 17-19 (p < 0.05). In SME, AdipoR1 protein expression peak occurred on days 2-3 (p < 0.05). The expression patterns of the AdipoR2 gene in MBH, POA and SME revealed the highest mRNA levels on days 2-3 of the cycle (p < 0.05). The highest content of AdipoR2 protein in MBH was reported on days 2-3 (p < 0.05), while in POA on days 17-19 and in SME on days 10-12 and 14-16 (p < 0.05). This study demonstrated that adiponectin and adiponectin receptor mRNAs and proteins are present in the porcine hypothalamus and that their expression levels are determined by the pig's endocrine status related to the oestrous cycle. © 2014 Blackwell Verlag GmbH.

TRPV2, a capsaicin receptor homologue, is expressed predominantly in the neurotrophin-3-dependent subpopulation of primary sensory neurons.

PubMed

Tamura, S; Morikawa, Y; Senba, E

2005-01-01

TRPV2, a member of transient receptor potential ion channels, responds to high-threshold noxious heat, but neither to capsaicin nor to proton. Although TRPV2 is expressed in medium- to large-sized dorsal root ganglion (DRG) neurons with myelinated fibers in adult rodents, little is known about the neurotrophin dependence of TRPV2-positive neurons in the developing and adult DRGs of mice. In the present study, using immunohistochemistry, we found that TRPV2 was first expressed in DRG neurons at embryonic day (E) 11.5, when neither TRPV1 nor TRPM8 was detected yet. Double-immunofluorescence staining revealed that tyrosine kinase receptor C (TrkC) was expressed in most of TRPV2-positive DRG neurons at E11.5 and E13.5. In addition, the percentage of TRPV2-positive neurons in the total DRG neurons at E13.5 reached the same as that of adulthood. In adult DRGs, TrkC and Ret were expressed in 68% and 25% of TRPV2-positive neurons, respectively. These results suggest that TRPV2 is expressed predominantly in the NT-3-dependent subpopulation of DRG neurons throughout development and in adult mice.

Identification of Critical Residues Involved in Ligand Binding and G Protein Signaling in Human Somatostatin Receptor Subtype 2

PubMed Central

Parry, Jesse J.; Chen, Ronald; Andrews, Rebecca; Lears, Kimberly A.

2012-01-01

G protein signaling through human somatostatin receptor subtype 2 (SSTR2) is well known, but the amino acids involved in stimulation of intracellular responses upon ligand binding have not been characterized. We constructed a series of point mutants in SSTR2 at amino acid positions 89, 139, and 140 in attempts to disrupt G protein signaling upon ligand binding. The aspartic acid changes at position 89 to either Ala, Leu, or Arg generated mutant receptors with varying expression profiles and a complete inability to bind somatostatin-14 (SST). Mutations to Asp 139 and Arg 140 also led to varying expression profiles with some mutants maintaining their affinity for SST. Mutation of Arg 140 to Ala resulted in a mutated receptor that had a Bmax and dissociation constant (Kd) similar to wild-type receptor but was still coupled to the G protein as determined in both a cAMP assay and a calcium-release assay. In contrast, mutation of Asp 139 to Asn resulted in a mutated receptor with Bmax and Kd values that were similar to wild type but was uncoupled from G protein-mediated cAMP signaling, but not calcium release. Thus, we identified mutations in SSTR2 that result in either receptor expression levels that are similar to wild type but is completely ablated for ligand binding or a receptor that maintains affinity for SST and is uncoupled from G protein-mediated cAMP signaling. PMID:22495673

Aberrant, ectopic expression of VEGF and VEGF receptors 1 and 2 in malignant colonic epithelial cells. Implications for these cells growth via an autocrine mechanism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahluwalia, Amrita; Jones, Michael K.; Department of Medicine, University of California, Irvine, CA

2013-08-09

Highlights: •Malignant colonic epithelial cells express VEGF and its receptors. •Cultured colon cancer cells secrete VEGF into the medium. •Inhibition of VEGF receptor significantly decreases colon cancer cell proliferation. •VEGF is critical for colon cancer cell growth. -- Abstract: Vascular endothelial growth factor A (referred to as VEGF) is implicated in colon cancer growth. Currently, the main accepted mechanism by which VEGF promotes colon cancer growth is via the stimulation of angiogenesis, which was originally postulated by late Judah Folkman. However, the cellular source of VEGF in colon cancer tissue; and, the expression of VEGF and its receptors VEGF-R1 andmore » VEGF-R2 in colon cancer cells are not fully known and are subjects of controversy. Material and methods: We examined and quantified expression of VEGF, VEGF-R1 and VEGF-R2 in three different human colonic tissue arrays containing sections of adenocarcinoma (n = 43) and normal mucosa (n = 41). In human colon cancer cell lines HCT116 and HT29 and normal colon cell lines NCM356 and NCM460, we examined expression of VEGF, VEGF-R1 and VEGF-R2 mRNA and protein, VEGF production and secretion into the culture medium; and, the effect of a potent, selective inhibitor of VEGF receptors, AL-993, on cell proliferation. Results: Human colorectal cancer specimens had strong expression of VEGF in cancer cells and also expressed VEGF-R1 and VEGF-R2.In vitro studies showed that human colon cancer cell lines, HCT116 and HT29, but not normal colonic cell lines, express VEGF, VEGF-R1 and VEGF-R2 and secrete VEGF into the medium up to a concentration 2000 pg/ml within 48 h. Furthermore, we showed that inhibition of VEGF receptors using a specific VEGF-R inhibitor significantly reduced proliferation (by >50%) of cultured colon cancer cell lines. Conclusions: Our findings support the contention that VEGF generated by colon cancer cells stimulates their growth directly through an autocrine mechanism that is independent of its primary function in the induction of angiogenesis.« less

Disordered expression of inhibitory receptors on the NK1-type natural killer (NK) leukaemic cells from patients with hypersensitivity to mosquito bites

PubMed Central

Seo, N; Tokura, Y; Ishihara, S; Takeoka, Y; Tagawa, S; Takigawa, M

2000-01-01

Recent studies have revealed the existence of a distinct type of NK cell leukaemia of the juvenile type, which presents with hypersensitivity to mosquito bites (HMB) as an essential clinical manifestation and is infected with clonal Epstein–Barr virus (EBV). This disorder is thus called HMB-EBV-NK disease and has been reported in Orientals, mostly from Japan. We investigated the profile of cytokine production and the expression of both types of NK inhibitory receptors, i.e. CD94 lectin-like dimers and killer-cell immunoglobulin-like receptors, in NK leukaemic cells from three patients with HMB-EBV-NK disease. It was found that freshly isolated NK leukaemic cells expressed mRNA for interferon-gamma (IFN-γ) and additionally produced IL-10 upon stimulation with IL-2, indicating that the NK cells were of NK1 type. More than 98% of NK cells from the patients bore CD94 at a higher level than did normal NK cells, whereas p70 or NKAT2, belonging to immunoglobulin-like receptor, was not expressed in those NK cells. Freshly isolated leukaemic NK cells transcribed mRNA for CD94-associated molecule NKG2C at an abnormally high level, and upon stimulation with IL-2 and/or IL-12 they expressed NKG2A as well. The disordered expression of these inhibitory receptors not only provides some insights into the pathogenesis of HMB-EBV-NK disease but also can be used as phenotypic markers for the diagnosis of this type of NK cell leukaemia. PMID:10844517

The Macrophage Galactose-Type Lectin Can Function as an Attachment and Entry Receptor for Influenza Virus

PubMed Central

Ng, Wy Ching; Liong, Stella; Tate, Michelle D.; Irimura, Tatsuro; Denda-Nagai, Kaori; Brooks, Andrew G.; Londrigan, Sarah L.

2014-01-01

Specific protein receptors that mediate internalization and entry of influenza A virus (IAV) have not been identified for any cell type. Sialic acid (SIA), the primary attachment factor for IAV hemagglutinin, is expressed by numerous cell surface glycoproteins and glycolipids, confounding efforts to identify specific receptors involved in virus infection. Lec1 Chinese hamster ovary (CHO) epithelial cells express cell surface SIA and bind IAV yet are largely resistant to infection. Here, we demonstrate that expression of the murine macrophage galactose-type lectin 1 (MGL1) by Lec1 cells enhanced Ca2+-dependent IAV binding and restored permissivity to infection. Lec1 cells expressing MGL1 were infected in the presence or absence of cell surface SIA, indicating that MGL1 can act as a primary receptor or as a coreceptor with SIA. Lec1 cells expressing endocytosis-deficient MGL1 mediated Ca2+-dependent IAV binding but were less sensitive to IAV infection, indicating that direct internalization via MGL1 can result in cellular infection. Together, these studies identify MGL1 as a cell surface glycoprotein that can act as an authentic receptor for both attachment and infectious entry of IAV. PMID:24257596

Long-Term Haloperidol Treatment Prolongs QT Interval and Increases Expression of Sigma 1 and IP3 Receptors in Guinea Pig Hearts.

PubMed

Stracina, Tibor; Slaninova, Iva; Polanska, Hana; Axmanova, Martina; Olejnickova, Veronika; Konecny, Petr; Masarik, Michal; Krizanova, Olga; Novakova, Marie

2015-07-01

Haloperidol is a neuroleptic drug used for a medication of various psychoses and deliria. Its administration is frequently accompanied by cardiovascular side effects, expressed as QT interval prolongation and occurrence of even lethal arrhythmias. Despite these side effects, haloperidol is still prescribed in Europe in clinical practice. Haloperidol binds to sigma receptors that are coupled with inositol 1,4,5-trisphosphate (IP3) receptors. Sigma receptors are expressed in various tissues, including heart muscle, and they modulate potassium channels. Together with IP3 receptors, sigma receptors are also involved in calcium handling in various tissues. Therefore, the present work aimed to study the effects of long-term haloperidol administration on the cardiac function. Haloperidol (2 mg/kg once a day) or vehiculum was administered by intraperitoneal injection to guinea pigs for 21 consecutive days. We measured the responsiveness of the hearts isolated from the haloperidol-treated animals to additional application of haloperidol. Expression of the sigma 1 receptor and IP3 receptors was studied by real time-PCR and immunohistochemical analyses. Haloperidol treatment caused the significant decrease in the relative heart rate and the prolongation of QT interval of the isolated hearts from the haloperidol-treated animals, compared to the hearts isolated from control animals. The expression of sigma 1 and IP3 type 1 and type 2 receptors was increased in both atria of the haloperidol-treated animals but not in ventricles. The modulation of sigma 1 and IP3 receptors may lead to altered calcium handling in cardiomyocytes and thus contribute to changed sensitivity of cardiac cells to arrhythmias.

[Expression of AMPA receptors and related protein in immobilization stressed rats and effect of Xiaoyaosan].

PubMed

Yue, Guang-Xin; Wang, Zhu-Feng; Zhang, Qiao-Li; Zhao, Xin; Yue, Li-Feng; Ding, Jie; Chen, Jia-Xu

2008-05-01

To observe protein expression changes of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor and related regulatory protein in the hippocampus and amygdala in chronic immobilization stressed rat and Xiaoyaosan's regulatory effect. Rats were tied 3 h per day to establish immobilization stress condition and treatment with Xiaoyaosan. After 7 days and 21 days stress, the protein expression of AMPA receptor subunit (GluR2/3), N-ethylmaleimide sensitive factor (NSF) and protein interacting with C-kinase 1 (PICK1) in hippocampus and amygdala were detected by using Western blot techniques. The expression of GluR2/3, NSF in dentate gyrus (DG) and amygdala were markedly attenuated (P < 0.05) and PICK1 in CA1 region were significantly increased (P < 0.05) in 7 d immobilization stressed rats while 7 days xiaoyaosan treatment showed an effective regulatory result to PICK1's changes. Under 21 days immobilization stressed condition, the expression of GluR2/3, NSF in CA1 region showed an increasing trend, and GluR2/3 showed a markedly increase (P < 0.01), but showed an significantly decreased trend in amygdala, Xiaoyaosan showed an effective result to such changes above (P < 0.05). The expression of PICK1 showed increasing trend in amygdala and xiaoyaosan could lower its expression (P < 0.05). There are different trends of the expression of AMPA receptor in repeat short-term stress versus chronic immobilization stress, and in hippocampal CA1 region versus amygdala. Xiaoyaosan has better regulation effect on the expression of AMPA receptors in the condition of chronic immobilization stress than those of repeat shortterm stress.

Pleural mesothelial cells express both BLT2 and PPARalpha and mount an integrated response to pleural leukotriene B4.

PubMed

Pace, Elisabetta; Ferraro, Maria; Mody, Christopher H; Melis, Mario R; Scafidi, Valeria; Bonanno, Anna; Profita, Mirella; Giarratano, Antonino; Gjomarkaj, Mark

2008-11-15

Leukotriene B(4) (LTB(4)) plays a crucial role in the recruitment of neutrophils into the pleural space. We identified for the first time the mechanisms by which LTB(4) interacts with mesothelial cells and recruits neutrophils in the pleural compartment. Primary pleural mesothelial cells express both the proinflammatory receptor for LTB(4) BLT2, and the anti-inflammatory receptor for LTB(4), PPARalpha. Parapneumonic pleural effusions highly increase BLT2 expression and, via BLT2 activation, increase the adhesion between mesothelial cells and neutrophils and the expression of ICAM-1 on mesothelial cells. The block of PPARalpha further increases both cell adhesion and ICAM-1 expression. BLT2 activation promotes the activation, on mesothelial cells, of STAT-1 but not the activation of NF-kappaB transcription factor. The increase of ICAM-1 expression is achieved via increased tyrosine phosphorylation activity since herbimycin, a tyrosine kinase inhibitor, reduces and since Na orthovanadate, a tyrosine phosphatase inhibitor, further increases ICAM-1 expression. This study demonstrates that pleural mesothelial cells, expressing both proinflammatory and anti-inflammatory LTB(4) receptors, are able to mount an integrated response to LTB(4) with a prevalence of BLT2 activities in the presence of an inflammatory milieu within the pleura.

Expression of protease-activated-receptor 2 (PAR-2) in human esophageal mucosa.

PubMed

Inci, Kamuran; Edebo, Anders; Olbe, Lars; Casselbrant, Anna

2009-01-01

The role of duodenal reflux in gastroesophageal reflux disease (GERD) containing bile salts and pancreatic enzymes (with special attention to trypsin) is still under discussion. Proteinase-activated receptors (PARs) are a novel family and PAR-2 is a unique member of this family because it is activated by trypsin. The aim of the present study was to examine the presence and the position of the PAR-2 receptor in human esophageal mucosa in different subgroups of GERD. Distal biopsies taken from healthy controls, patients with erosive reflux disease (ERD), patients with specialized intestinal metaplasia (SIM) and adenocarcinoma were analyzed for the PAR-2 receptor with reverse-transcription polymerase chain reaction (RT-PCR), Western blotting and immunohistochemistry. Gene transcripts for the PAR-2 receptor were found in all groups, with increased levels in SIM patients compared to controls. However, this visual pattern was not seen for the protein expression of the PAR-2 receptor showing no apparent quantitative differences between the groups. Immunohistochemistry revealed distinct staining for the PAR-2 receptor in the luminal part of the esophageal epithelium. The localization of the PAR-2 receptor indicates that the receptor can be cleaved and activated by trypsin in duodenogastric esophageal refluxate. The data thus suggest that the trypsin-PAR-2 pathway may be involved in the pathogenesis of GERD.

Regulatory role of melatonin and BMP-4 in prolactin production by rat pituitary lactotrope GH3 cells.

PubMed

Ogura-Ochi, Kanako; Fujisawa, Satoshi; Iwata, Nahoko; Komatsubara, Motoshi; Nishiyama, Yuki; Tsukamoto-Yamauchi, Naoko; Inagaki, Kenichi; Wada, Jun; Otsuka, Fumio

2017-08-01

The effects of melatonin on prolactin production and its regulatory mechanism remain uncertain. We investigated the regulatory role of melatonin in prolactin production using rat pituitary lactotrope GH3 cells by focusing on the bone morphogenetic protein (BMP) system. Melatonin receptor activation, induced by melatonin and its receptor agonist ramelteon, significantly suppressed basal and forskolin-induced prolactin secretion and prolactin mRNA expression in GH3 cells. The melatonin MT2 receptor was predominantly expressed in GH3 cells, and the inhibitory effects of melatonin on prolactin production were reversed by treatment with the receptor antagonist luzindole, suggesting functional involvement of MT2 action in the suppression of prolactin release. Melatonin receptor activation also suppressed BMP-4-induced prolactin expression by inhibiting phosphorylation of Smad and transcription of the BMP-target gene Id-1, while BMP-4 treatment upregulated MT2 expression. Melatonin receptor activation suppressed basal, BMP-4-induced and forskolin-induced cAMP synthesis; however, BtcAMP-induced prolactin mRNA expression was not affected by melatonin or ramelteon, suggesting that MT2 activation leads to inhibition of prolactin production through the suppression of Smad signaling and cAMP synthesis. Experiments using intracellular signal inhibitors revealed that the ERK pathway is, at least in part, involved in prolactin induction by GH3 cells. Thus, a new regulatory role of melatonin involving BMP-4 in prolactin secretion was uncovered in lactotrope GH3 cells. Copyright © 2017 Elsevier Inc. All rights reserved.

Convergent Pathways for Steroid Hormone-and Neurotransmitter-Induced Rat Sexual Behavior

NASA Astrophysics Data System (ADS)

Mani, S. K.; Allen, J. M. C.; Clark, J. H.; Blaustein, J. D.; O'Malley, B. W.

1994-08-01

Estrogen and progesterone modulate gene expression in rodents by activation of intracellular receptors in the hypothalamus, which regulate neuronal networks that control female sexual behavior. However, the neurotransmitter dopamine has been shown to activate certain steroid receptors in a ligand-independent manner. A dopamine receptor stimulant and a D_1 receptor agonist, but not a D_2 receptor agonist, mimicked the effects of progesterone in facilitating sexual behavior in female rats. The facilitatory effect of the neurotransmitter was blocked by progesterone receptor antagonists, a D_1 receptor antagonist, or antisense oligonucleotides to the progesterone receptor. The results suggest that in rodents neurotransmitters may regulate in vivo gene expression and behavior by means of cross-talk with steroid receptors in the brain.

Mutation of Three Residues in the Third Intracellular Loop of the Dopamine D2 Receptor Creates an Internalization-defective Receptor*

PubMed Central

Clayton, Cecilea C.; Donthamsetti, Prashant; Lambert, Nevin A.; Javitch, Jonathan A.; Neve, Kim A.

2014-01-01

Arrestins mediate desensitization and internalization of G protein-coupled receptors and also direct receptor signaling toward heterotrimeric G protein-independent signaling pathways. We previously identified a four-residue segment (residues 212–215) of the dopamine D2 receptor that is necessary for arrestin binding in an in vitro heterologous expression system but that also impairs receptor expression. We now describe the characterization of additional mutations at that arrestin binding site in the third intracellular loop. Mutating two (residues 214 and 215) or three (residues 213–215) of the four residues to alanine partially decreased agonist-induced recruitment of arrestin3 without altering activation of a G protein. Arrestin-dependent receptor internalization, which requires arrestin binding to β2-adaptin (the β2 subunit of the clathrin-associated adaptor protein AP2) and clathrin, was disproportionately affected by the three-residue mutation, with no agonist-induced internalization observed even in the presence of overexpressed arrestin or G protein-coupled receptor kinase 2. The disjunction between arrestin recruitment and internalization could not be explained by alterations in the time course of the receptor-arrestin interaction, the recruitment of G protein-coupled receptor kinase 2, or the receptor-induced interaction between arrestin and β2-adaptin, suggesting that the mutation impairs a property of the internalization complex that has not yet been identified. PMID:25336643

Endocytosis as a mechanism of regulating natural killer cell function: unique endocytic and trafficking pathway for CD94/NKG2A.

PubMed

Peruzzi, Giovanna; Masilamani, Madhan; Borrego, Francisco; Coligan, John E

2009-01-01

Natural killer (NK) cells are lymphocytes generally recognized as sentinels of the innate immune system due to their inherent capacity to deal with diseased (stressed) cells, including malignant and infected. This ability to recognize many potentially pathogenic situations is due to the expression of a diverse panel of activation receptors. Because NK cell activation triggers an aggressive inflammatory response, it is important to have a means of throttling this response. Hence, NK cells also express a panel of inhibitory receptors that recognize ligands expressed by "normal" cells. Little or nothing is known about the endocytosis and trafficking of NK cell receptors, which are of great relevance to understanding how NK cells maintain the appropriate balance of activating and inhibitory receptors on their cell surface. In this review, we focus on the ITIM-containing inhibitory receptor CD94/NKG2A showing that it is endocytosed by a previously undescribed macropinocytic-like process that may be related to the maintenance of its surface expression.

Characterization of the expression and clinical features of epidermal growth factor receptor and vascular endothelial growth factor receptor-2 in esophageal carcinoma

PubMed Central

NIYAZ, MADINIYAT; ANWER, JURAT; LIU, HUI; ZHANG, LIWEI; SHAYHEDIN, ILYAR; AWUT, IDIRIS

2015-01-01

The present study aimed to understand the expression characteristics of epidermal growth factor receptor (EGFR) and vascular endothelial growth factor receptor-2 (VEGFR-2) in individuals of Uygur, Han and Kazak ethnicity with esophageal carcinoma in Xinjiang (China) and their interrelation analysis, and to investigate the expression differences in these genes between esophageal carcinoma and pericarcinoma tissue samples, and between the three ethnic groups. The expression levels of EGFR and VEGFR-2 from 119 pairs of esophageal carcinoma tissue and corresponding pericarcinoma tissue from Uygur, Han and Kazak patients with esophageal carcinoma were detected by immunohistochemistry following surgical resection, and an additional five carcinoma in situ specimens were also tested. The relative expression was analyzed among the ethnic groups and clinicopathological parameters. The positive rate of EGFR in esophageal carcinoma tissue from patients of Uygur, Han and Kazak heritage was 70.73, 68.42 and 67.5%, respectively. For VEGFR-2 the positive rate was 73.17, 68.42 and 67.5%, respectively. No significant difference was detected in their expression between the three ethnic groups (P>0.05); however, EGFR and VEGFR-2 overexpression were correlated with lymph node metastasis (P<0.05). VEGF expression was also correlated with the expression of VEGFR-2 in esophageal carcinoma tissues. EGFR was positive in carcinoma in situ samples, while VEGFR-2 was negative. The overexpression of EGFR is therefore an early event and may have a significant role in the progression of esophageal carcinoma pathogenesis. EGFR overexpression may correlate with the expression of VEGFR-2 in esophageal cancer. These results may aid the early diagnosis of esophageal cancer, and the development of individual target treatment in the future. PMID:26788193

Expression of genes associated with immunity in the endometrium of cattle with disparate postpartum uterine disease and fertility

PubMed Central

Herath, Shan; Lilly, Sonia T; Santos, Natalia R; Gilbert, Robert O; Goetze, Leopold; Bryant, Clare E; White, John O; Cronin, James; Sheldon, I Martin

2009-01-01

Background Contamination of the uterine lumen with bacteria is ubiquitous in cattle after parturition. Some animals develop endometritis and have reduced fertility but others have no uterine disease and readily conceive. The present study tested the hypothesis that postpartum cattle that develop persistent endometritis and infertility are unable to limit the inflammatory response to uterine bacterial infection. Methods Endometrial biopsies were collected several times during the postpartum period from animals that were subsequently infertile with persistent endometritis (n = 4) or had no clinical disease and conceived to first insemination (n = 4). Quantitative PCR was used to determine the expression of candidate genes in the endometrial biopsies, including the Toll-like receptor (TLR 1 to 10) family of innate immune receptors, inflammatory mediators and their cognate receptors. Selected proteins were examined by immunohistochemistry. Results The expression of genes encoding pro-inflammatory mediators such as interleukins (IL1A, IL1B and IL6), and nitric oxide synthase 2 (NOS2) were higher during the first week post partum than subsequently. During the first week post partum, there was higher gene expression in infertile than fertile animals of TLR4, the receptor for bacterial lipopolysaccharide, and the pro-inflammatory cytokines IL1A and IL1B, and their receptor IL1R2. The expression of genes encoding other Toll-like receptors, transforming growth factor beta receptor 1 (TGFBR1) or prostaglandin E2 receptors (PTGER2 and PTGER4) did not differ significantly between the animal groups. Gene expression did not differ significantly between infertile and fertile animals after the first week postpartum. However, there were higher ratios of IL1A or IL1B mRNA to the anti-inflammatory cytokine IL10, during the first week post partum in the infertile than fertile animals, and the protein products of these genes were mainly localised to the epithelium of the endometrium. Conclusion Cattle may maintain fertility by limiting the inflammatory response to postpartum bacterial infection in the endometrium during the first week after parturition. PMID:19476661

Expression of functional receptors by the human γ-aminobutyric acid A γ2 subunit

PubMed Central

Martínez-Torres, Ataúlfo; Miledi, Ricardo

2004-01-01

γ-Aminobutyric acid A (GABAA) receptors are heteromeric membrane proteins formed mainly by various combinations of α, β, and γ subunits; and it is commonly thought that the γ2 subunit alone does not form functional receptors. In contrast, we found that cDNA encoding the γ2L subunit of the human GABAA receptor, injected alone into Xenopus oocytes, expressed functional GABA receptors whose properties were investigated by using the two-microelectrode voltage-clamp technique. GABA elicited desensitizing membrane currents that recovered after a few minutes' wash. Repetitive applications of GABA induced a “run-up” of GABA currents that nearly doubled the amplitude of the first response. The GABA currents inverted direction at about -30 mV, indicating that they are carried mainly by Cl- ions. The homomeric γ2L receptors were also activated by β-alanine > taurine > glycine, and, like some types of heteromeric GABAA receptors, the γ2L receptors were blocked by bicuculline and were potentiated by pentobarbital and flunitrazepam. These results indicate that the human γ2L subunit is capable of forming fully functional GABA receptors by itself in Xenopus oocytes and suggest that the roles proposed for the various subunits that make up the heteromeric GABAA receptors in situ require further clarification. PMID:14981251

Balance between somatostatin and D2 receptor expression drives TSH-secreting adenoma response to somatostatin analogues and dopastatins.

PubMed

Gatto, Federico; Barbieri, Federica; Gatti, Monica; Wurth, Roberto; Schulz, Stefan; Ravetti, Jean-Louis; Zona, Gianluigi; Culler, Michael D; Saveanu, Alexandru; Giusti, Massimo; Minuto, Francesco; Hofland, Leo J; Ferone, Diego; Florio, Tullio

2012-03-01

First-line therapy for thyrotropin-secreting pituitary adenomas (TSHomas) is neurosurgery, while medical treatment rests mainly on somatostatin analogues. Clinically available sst(2) -preferring analogues, octreotide and lanreotide, induce normalization of hormone levels in approximately 90% of patients and tumour shrinkage in 45%. We evaluated somatostatin 1, 2, 3 and 5 and dopamine D2 receptor expression in tumour samples from three TSHomas, and the relationships between receptor expression, in vitro antiproliferative response and clinical data, including octreotide test and three months of therapy with octreotide long-acting repeatable (LAR). TSHoma cell proliferation was tested in vitro using octreotide, cabergoline and two chimeric compounds, BIM-23A760 and BIM-23A387. All patients showed significant TSH lowering to acute octreotide test, but a hormonal response to long-term treatment was observed in only two patients, showing a high sst(5) /sst(2) ratio. Patient 2, characterized by high expression of sst(2) and sst(1) and a relative lower expression of sst(5) , experienced tachyphylaxis after prolonged octreotide treatment. In vitro, the somatostatin/dopamine receptor agonist BIM-23A760 caused the highest antiproliferative effect among those tested. Combined treatment with octreotide and cabergoline displayed an additive effect of magnitude comparable to that of the other chimeric compound (BIM-23A387). Octreotide resistance was confirmed in cells isolated from the nonresponder patient, although it could be overcome by treatment with the chimeric compounds.   A high sst(5) /sst(2) ratio might be predictive of a positive outcome to long-term treatment with somatostatin analogues in TSHomas. Moreover, combined somatostatin and D(2) receptor targeting might be considered as a potential tool to improve the response rate in octreotide-resistant tumours. © 2012 Blackwell Publishing Ltd.

The diverse CB1 and CB2 receptor pharmacology of three plant cannabinoids: Δ9-tetrahydrocannabinol, cannabidiol and Δ9-tetrahydrocannabivarin

PubMed Central

Pertwee, R G

2007-01-01

Cannabis sativa is the source of a unique set of compounds known collectively as plant cannabinoids or phytocannabinoids. This review focuses on the manner with which three of these compounds, (−)-trans-Δ9-tetrahydrocannabinol (Δ9-THC), (−)-cannabidiol (CBD) and (−)-trans-Δ9-tetrahydrocannabivarin (Δ9-THCV), interact with cannabinoid CB1 and CB2 receptors. Δ9-THC, the main psychotropic constituent of cannabis, is a CB1 and CB2 receptor partial agonist and in line with classical pharmacology, the responses it elicits appear to be strongly influenced both by the expression level and signalling efficiency of cannabinoid receptors and by ongoing endogenous cannabinoid release. CBD displays unexpectedly high potency as an antagonist of CB1/CB2 receptor agonists in CB1- and CB2-expressing cells or tissues, the manner with which it interacts with CB2 receptors providing a possible explanation for its ability to inhibit evoked immune cell migration. Δ9-THCV behaves as a potent CB2 receptor partial agonist in vitro. In contrast, it antagonizes cannabinoid receptor agonists in CB1-expressing tissues. This it does with relatively high potency and in a manner that is both tissue and ligand dependent. Δ9-THCV also interacts with CB1 receptors when administered in vivo, behaving either as a CB1 antagonist or, at higher doses, as a CB1 receptor agonist. Brief mention is also made in this review, first of the production by Δ9-THC of pharmacodynamic tolerance, second of current knowledge about the extent to which Δ9-THC, CBD and Δ9-THCV interact with pharmacological targets other than CB1 or CB2 receptors, and third of actual and potential therapeutic applications for each of these cannabinoids. PMID:17828291

Methionine Deprivation Induces a Targetable Vulnerability in Triple-Negative Breast Cancer Cells by Enhancing TRAIL Receptor-2 Expression.

PubMed

Strekalova, Elena; Malin, Dmitry; Good, David M; Cryns, Vincent L

2015-06-15

Many neoplasms are vulnerable to methionine deficiency by mechanisms that are poorly understood. Because gene profiling studies have revealed that methionine depletion increases TNF-related apoptosis-inducing ligand receptor-2 (TRAIL-R2) mRNA, we postulated that methionine stress sensitizes breast cancer cells to proapoptotic TRAIL-R2 agonists. Human triple (ER/PR/HER2)-negative breast carcinoma cell lines were cultured in control or methionine-free media. The effects of methionine depletion on TRAIL receptor expression and sensitivity to chemotherapy or a humanized agonistic TRAIL-R2 monoclonal antibody (lexatumumab) were determined. The melanoma-associated antigen MAGED2 was silenced to delineate its functional role in sensitizing TNBC cells to methionine stress. An orthotopic TNBC model was utilized to evaluate the effects of dietary methionine deficiency, lexatumumab, or the combination. Methionine depletion sensitized TNBC cells to lexatumumab-induced caspase activation and apoptosis by increasing TRAIL-R2 mRNA and cell surface expression. MCF-10A cells transformed by oncogenic H-Ras, but not untransformed cells, and matrix-detached TNBC cells were highly sensitive to the combination of lexatumumab and methionine depletion. Proteomics analyses revealed that MAGED2, which has been reported to reduce TRAIL-R2 expression, was suppressed by methionine stress. Silencing MAGED2 recapitulated features of methionine deprivation, including enhanced mRNA and cell surface expression of TRAIL receptors and increased sensitivity to TRAIL receptor agonists. Dietary methionine deprivation enhanced the antitumor effects of lexatumumab in an orthotopic metastatic TNBC model. Methionine depletion exposes a targetable defect in TNBC cells by increasing TRAIL-R2 expression. Our findings provide the foundation for a clinical trial combining dietary methionine restriction and TRAIL-R2 agonists. Clin Cancer Res; 21(12); 2780-91. ©2015 AACR. ©2015 American Association for Cancer Research.

Small GTPase Rab17 Regulates the Surface Expression of Kainate Receptors but Not α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid (AMPA) Receptors in Hippocampal Neurons via Dendritic Trafficking of Syntaxin-4 Protein*

PubMed Central

Mori, Yasunori; Fukuda, Mitsunori; Henley, Jeremy M.

2014-01-01

Glutamate receptors are fundamental for control synaptic transmission, synaptic plasticity, and neuronal excitability. However, many of the molecular mechanisms underlying their trafficking remain elusive. We previously demonstrated that the small GTPase Rab17 regulates dendritic trafficking in hippocampal neurons. Here, we investigated the role(s) of Rab17 in AMPA receptor (AMPAR) and kainate receptor (KAR) trafficking. Although Rab17 knockdown did not affect surface expression of the AMPAR subunit GluA1 under basal or chemically induced long term potentiation conditions, it significantly reduced surface expression of the KAR subunit GluK2. Rab17 co-localizes with Syntaxin-4 in the soma, dendritic shaft, the tips of developing hippocampal neurons, and in spines. Rab17 knockdown caused Syntaxin-4 redistribution away from dendrites and into axons in developing hippocampal neurons. Syntaxin-4 knockdown reduced GluK2 but had no effect on GluA1 surface expression. Moreover, overexpression of constitutively active Rab17 promoted dendritic surface expression of GluK2 by enhancing Syntaxin-4 translocation to dendrites. These data suggest that Rab17 mediates the dendritic trafficking of Syntaxin-4 to selectively regulate dendritic surface insertion of GluK2-containing KARs in rat hippocampal neurons. PMID:24895134

Decreased Cocaine Motor Sensitization and Self-Administration in Mice Overexpressing Cannabinoid CB2 Receptors

PubMed Central

Aracil-Fernández, Auxiliadora; Trigo, José M; García-Gutiérrez, María S; Ortega-Álvaro, Antonio; Ternianov, Alexander; Navarro, Daniela; Robledo, Patricia; Berbel, Pere; Maldonado, Rafael; Manzanares, Jorge

2012-01-01

The potential involvement of the cannabinoid CB2 receptors (CB2r) in the adaptive responses induced by cocaine was studied in transgenic mice overexpressing the CB2r (CB2xP) and in wild-type (WT) littermates. For this purpose, the acute and sensitized locomotor responses to cocaine, conditioned place preference, and cocaine intravenous self-administration were evaluated. In addition, we assessed whether CB2r were localized in neurons and/or astrocytes, and whether they colocalized with dopamine D1 and D2 receptors (D1Dr and D2Dr). Dopamine (DA) extracellular levels in the nucleus accumbens (NAcc), and gene expression of tyrosine hydroxylase (TH) and DA transporter (DAT) in the ventral tegmental area (VTA), and μ-opioid and cannabinoid CB1 receptors in the NAcc were also studied in both genotypes. CB2xP mice showed decreased motor response to acute administration of cocaine (10–20 mg/kg) and cocaine-induced motor sensitization compared with WT mice. CB2xP mice presented cocaine-induced conditioned place aversion and self-administered less cocaine than WT mice. CB2r were found in neurons and astrocytes and colocalized with D2Dr in the VTA and NAcc. No significant differences in extracellular DA levels in the NAcc were observed between genotypes after cocaine administration. Under baseline conditions, TH and DAT gene expression was higher and μ-opioid receptor gene expression was lower in CB2xP than in WT mice. However, both genotypes showed similar changes in TH and μ-opioid receptor gene expression after cocaine challenge independently of the pretreatment received. Importantly, the cocaine challenge decreased DAT gene expression to a lesser extent in cocaine-pretreated CB2xP than in cocaine-pretreated WT mice. These results revealed that CB2r are involved in cocaine motor responses and cocaine self-administration, suggesting that this receptor could represent a promising target to develop novel treatments for cocaine addiction. PMID:22414816

NMDA Receptors Regulate Genes Responsible for Major Immune Functions of Mononuclears in Human Peripheral Blood.

PubMed

Kuzmina, U Sh; Zainullina, L F; Sadovnikov, S V; Vakhitov, V A; Vakhitova, Yu V

2018-06-19

To determine the role of NMDA receptors in the functional regulation of immunocompetent cells, comparative assay was carried out for genes expressed in the mononuclears in peripheral blood of healthy persons under normal conditions and after blockade of these receptors. The genes, whose expression changed in response to blockade of NMDA receptors in mononuclears, encode the products involved in regulation of the major functions of immune cells, such as proliferation (IL4, VCAM1, and CDKN2A), apoptosis (BAX, MYC, CDKN2A, HSPB1, and CADD45A), activation (IL4R, IL4, VCAM1, and CDKN2A), and differentiation (IL4, VCAM1, and BAX).

Octopaminergic gene expression and flexible social behaviour in the subsocial burying beetle Nicrophorus vespilloides

PubMed Central

Cunningham, C B; Douthit, M K; Moore, A J

2014-01-01

Flexible behaviour allows organisms to respond appropriately to changing environmental and social conditions. In the subsocial beetle Nicrophorus vespilloides, females tolerate conspecifics when mating, become aggressive when defending resources, and return to social tolerance when transitioning to parenting. Given the association between octopamine and aggression in insects, we hypothesized that genes in the octopaminergic system would be differentially expressed across different social and reproductive contexts. To test this in N. vespilloides, we first obtained the sequences of orthologues of the synthetic enzymes and receptors of the octopaminergic system. We next compared relative gene expression from virgin females, mated females, mated females alone on a resource required for reproduction and mated females on a resource with a male. Expression varied for five receptor genes. The expression of octopamine β receptor 1 and octopamine β receptor 2 was relatively higher in mated females than in other social conditions. Octopamine β receptor 3 was influenced by the presence or absence of a resource and less by social environment. Octopamine α receptor and octopamine/tyramine receptor 1 gene expression was relatively lower in the mated females with a resource and a male. We suggest that in N. vespilloides the octopaminergic system is associated with the expression of resource defence, alternative mating tactics, social tolerance and indirect parental care. PMID:24646461

Regional expression patterns of taste receptors and gustducin in the mouse tongue.

PubMed

Kim, Mi-Ryung; Kusakabe, Yuko; Miura, Hirohito; Shindo, Yoichiro; Ninomiya, Yuzo; Hino, Akihiro

2003-12-12

In order to understand differences in taste sensitivities of taste bud cells between the anterior and posterior part of tongue, it is important to analyze the regional expression patterns of genes related to taste signal transduction on the tongue. Here we examined the expression pattern of a taste receptor family, the T1r family, and gustducin in circumvallate and fungiform papillae of the mouse tongue using double-labeled in situ hybridization. Each member of the T1r family was expressed in both circumvallate and fungiform papillae with some differences in their expression patterns. The most striking difference between fungiform and circumvallate papillae was observed in their co-expression patterns of T1r2, T1r3, and gustducin. T1r2-positive cells in fungiform papillae co-expressed T1r3 and gustducin, whereas T1r2 and T1r3 double-positive cells in circumvallate papillae merely expressed gustducin. These results suggested that in fungiform papillae, gustducin might play a role in the sweet taste signal transduction cascade mediated by a sweet receptor based on the T1r2 and T1r3 combination, in fungiform papillae.

Dopaminergic Modulation of Risky Decision-Making

PubMed Central

Simon, Nicholas W.; Montgomery, Karienn S.; Beas, Blanca S.; Mitchell, Marci R.; LaSarge, Candi L.; Mendez, Ian A.; Bañuelos, Cristina; Vokes, Colin M.; Taylor, Aaron B.; Haberman, Rebecca P.; Bizon, Jennifer L.; Setlow, Barry

2012-01-01

Many psychiatric disorders are characterized by abnormal risky decision-making and dysregulated dopamine receptor expression. The current study was designed to determine how different dopamine receptor subtypes modulate risk-taking in young adult rats, using a “Risky Decision-making Task” that involves choices between small “safe” rewards and large “risky” rewards accompanied by adverse consequences. Rats showed considerable, stable individual differences in risk preference in the task, which were not related to multiple measures of reward motivation, anxiety, or pain sensitivity. Systemic activation of D2-like receptors robustly attenuated risk-taking, whereas drugs acting on D1-like receptors had no effect. Systemic amphetamine also reduced risk-taking, an effect which was attenuated by D2-like (but not D1-like) receptor blockade. Dopamine receptor mRNA expression was evaluated in a separate cohort of drug-naive rats characterized in the task. D1 mRNA expression in both nucleus accumbens shell and insular cortex was positively associated with risk-taking, while D2 mRNA expression in orbitofrontal and medial prefrontal cortex predicted risk preference in opposing nonlinear patterns. Additionally, lower levels of D2 mRNA in dorsal striatum were associated with greater risk-taking. These data strongly implicate dopamine signaling in prefrontal corticalstriatal circuitry in modulating decision-making processes involving integration of reward information with risks of adverse consequences. PMID:22131407

Comparison of prostaglandin F2alpha, bimatoprost (prostamide), and butaprost (EP2 agonist) on Cyr61 and connective tissue growth factor gene expression.

PubMed

Liang, Yanbin; Li, Chen; Guzman, Victor M; Evinger, Albert J; Protzman, Charles E; Krauss, Achim H-P; Woodward, David F

2003-07-18

Connective tissue growth factor (CTGF) and Cyr61 (cysteine-rich angiogenic protein 61) are members of the CCN gene family that encode multifunctional, extracellular matrix-associated signaling proteins. Because the mechanism of action of certain anti-glaucoma drugs involves extracellular matrix remodeling of ocular ciliary muscle, with a resultant increase in drainage of aqueous humor from the eye, we compared the effects of three pharmacologically distinct ocular hypotensive agents on Cyr61 and CTGF gene expression. Thus, prostaglandin F2alpha (PGF2alpha) (FP receptor agonist), Butaprost (EP2 receptor agonist), and Bimatoprost (a prostamide) were compared. Using Affymetrix gene chip technology, we first identified that PGF2alpha dramatically up-regulated Cyr61 and CTGF mRNA expression in HEK 293/EBNA cells (hFP-HEK 293/EBNA). Northern blot further confirmed the Cyr61 and CTGF up-regulation is in a dose- and time-dependent manner. PGF2alpha-induced up-regulation of Cyr61 appeared to exclusively involve the Rho pathway, and up-regulation of CTGF was via multiple intracellular pathways. Because prostamide receptors are, to date, defined only at the pharmacological level, Bimatoprost effects on Cyr61 and CTGF were studied in the isolated feline iris sphincter preparation, a tissue highly responsive to prostamides. Both PGF2alpha and Bimatoprost up-regulated Cyr61 mRNA expression in the cat iris tissue. Only PGF2alpha up-regulated CTGF mRNA expression in the cat iris. Therefore, PGF2alpha and Bimatoprost appear to interact with different receptors populations in the cat iris, according to their markedly different effects on CTGF. Activation of prostaglandin EP2 receptors (Gs-coupled) also up-regulated Cyr61 but not CTGF mRNA expression in the isolated cat iris. Similar data were observed in human primary ciliary smooth muscle cells. Thus, despite quite different signal transduction pathways, FP receptor stimulation up-regulates CTGF and Cyr61. The prostamide analog Bimatoprost and an EP2-selective agonist affects only Cyr61.

Rapid resensitization of purinergic receptor function in human platelets.

PubMed

Mundell, S J; Barton, J F; Mayo-Martin, M B; Hardy, A R; Poole, A W

2008-08-01

Adenosine diphosphate (ADP) is a critical regulator of platelet activation, mediating its actions through two G protein-coupled receptors (GPCRs), the P2Y(1) and P2Y(12) purinergic receptors. Recently, we demonstrated that both receptors desensitize and internalize in human platelets by differential kinase-dependent mechanisms. To demonstrate whether responses to P2Y(1) and P2Y(12) purinergic receptors resensitize in human platelets and determine the role of receptor traffic in this process. These studies were undertaken either in human platelets or in cells stably expressing epitope-tagged P2Y(1) and P2Y(12) purinergic receptor constructs. In this study we show for the first time that responses to both of these receptors can rapidly resensitize following agonist-dependent desensitization in human platelets. Further, we show that in human platelets or in 1321N1 cells stably expressing receptor constructs, the disruption of receptor internalization, dephosphorylation or subsequent receptor recycling is sufficient to block resensitization of purinergic receptor responses. We also show that, in platelets, internalization of both these receptors is dependent upon dynamin, and that this process is required for resensitization of responses. This study is therefore the first to show that both P2Y(1) and P2Y(12) receptor activities are rapidly and reversibly modulated in human platelets, and it reveals that the underlying mechanism requires receptor trafficking as an essential part of this process.

Evidence of alterations in the expression of orphan receptors GPR26 and GPR39 due to the etiology of the metabolic syndrome.

PubMed

Romero-Nava, Rodrigo; Zhou, De-Shan; García, Noemí; Ruiz-Hernández, Armando; Si, Yin-Chu; Sánchez-Muñoz, Fausto; Huang, Fengyang; Hong, Enrique; Villafaña, Santiago

2017-08-01

Metabolic syndrome (MS) is composed of several metabolic abnormalities that increase the risk of cardiovascular diseases and diabetes. Although there are treatments for the components of MS, this pathology maintains a high mortality, suggesting that there are other mechanisms in which orphan receptors such as GPR26 and GPR39 may be involved. For this reason, the aim of this work was to evaluate the expression of GPR26 and GPR39 orphan receptors in two models of MS (diet and genetics). We used male Wistar rats, which received 70% fructose in drinking water for 9 weeks, and obese Zucker rats. We measured weight, blood pressure, glucose, triglycerides, total cholesterol, HDL cholesterol, LDL cholesterol to determine the MS and the expression of the orphan receptors GPR26 and GPR39 in brain, heart, aorta, liver, and kidney by RT-PCR. The analysis of the expression of the orphan receptors GPR26 and GPR39 showed that the receptors are expressed in some tissues, but the expression of the GPR26 tends to decrease in the heart and aorta, whereas in the brain, no changes were observed, this receptor is not expressed in the liver and kidney of both strains. The expression of GPR39 isoforms depends on the tissue and MS model. We conclude that the orphan receptors GPR26, GPR39v1, and GPR39v2 are expressed in different tissues and their profile expression is dependent on the etiology of the MS.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharpe, Laura J.; Brown, Andrew J.

As a key regulator of cholesterol homeostasis, sterol-regulatory element binding protein-2 (SREBP-2) up-regulates expression of genes involved in cholesterol synthesis (e.g., 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) Reductase) and uptake (the low density lipoprotein (LDL)-receptor). Previously, we showed that Akt, a critical kinase in cell growth and proliferation, contributes to SREBP-2 activation. However, the specific Akt target involved is unknown. A potential candidate is the mammalian target of rapamycin, mTOR. Rapamycin can cause hyperlipidaemia clinically, and we hypothesised that this may be mediated via an effect of mTOR on SREBP-2. Herein, we found that SREBP-2 activation and HMG-CoA Reductase gene expression were unaffectedmore » by rapamycin treatment. However, LDL-receptor gene expression was decreased by rapamycin, suggesting that this may contribute to the hyperlipidaemia observed in rapamycin-treated patients. Rapamycin did not affect mRNA stability, so the decrease in LDL-receptor gene expression is likely to be occurring at the transcriptional level, although independently of SREBP-2.« less

Differential expression of pancreatic protein and chemosensing receptor mRNAs in NKCC1-null intestine

PubMed Central

Bradford, Emily M; Vairamani, Kanimozhi; Shull, Gary E

2016-01-01

AIM: To investigate the intestinal functions of the NKCC1 Na+-K+-2Cl cotransporter (SLC12a2 gene), differential mRNA expression changes in NKCC1-null intestine were analyzed. METHODS: Microarray analysis of mRNA from intestines of adult wild-type mice and gene-targeted NKCC1-null mice (n = 6 of each genotype) was performed to identify patterns of differential gene expression changes. Differential expression patterns were further examined by Gene Ontology analysis using the online Gorilla program, and expression changes of selected genes were verified using northern blot analysis and quantitative real time-polymerase chain reaction. Histological staining and immunofluorescence were performed to identify cell types in which upregulated pancreatic digestive enzymes were expressed. RESULTS: Genes typically associated with pancreatic function were upregulated. These included lipase, amylase, elastase, and serine proteases indicative of pancreatic exocrine function, as well as insulin and regenerating islet genes, representative of endocrine function. Northern blot analysis and immunohistochemistry showed that differential expression of exocrine pancreas mRNAs was specific to the duodenum and localized to a subset of goblet cells. In addition, a major pattern of changes involving differential expression of olfactory receptors that function in chemical sensing, as well as other chemosensing G-protein coupled receptors, was observed. These changes in chemosensory receptor expression may be related to the failure of intestinal function and dependency on parenteral nutrition observed in humans with SLC12a2 mutations. CONCLUSION: The results suggest that loss of NKCC1 affects not only secretion, but also goblet cell function and chemosensing of intestinal contents via G-protein coupled chemosensory receptors. PMID:26909237

Steroid signaling system responds differently to temperature and hormone manipulation in the red-eared slider turtle (Trachemys scripta elegans), a reptile with temperature-dependent sex determination.

PubMed

Ramsey, M; Crews, D

2007-01-01

Many reptiles, including the red-eared slider turtle (Trachemys scripta elegans), exhibit temperature-dependent sex determination (TSD). Temperature determines gonadal sex during the middle of embryogenesis, or the temperature-sensitive period (TSP), when gonadal sex is labile to both temperature and hormones--particularly estrogen. The biological actions of steroid hormones are mediated by their receptors as defined here as the classic transcriptional regulation of target genes. To elucidate estrogen action during sex determination, we examined estrogen receptor alpha (Esr1, hereafter referred to as ERalpha), estrogen receptor beta (Esr2, hereafter referred to as ERbeta), and androgen receptor (Ar, hereafter referred to as AR) expression in slider turtle gonads before, during and after the TSP, as well as following sex reversal via temperature or steroid hormone manipulation. ERalpha and AR levels spike at the female-producing temperature while ovarian sex is determined, but none of the receptors exhibited sexually dimorphic localization within the gonad prior to morphological differentiation. All three receptors respond differentially to sex-reversing treatments. When shifted to female-producing temperatures, embryos maintain ERalpha and AR expression while ERbeta is reduced. When shifted to male-producing temperatures, medullary expression of all three receptors is reduced. Feminization via estradiol (E(2)) treatment at a male-producing temperature profoundly changed the expression patterns for all three receptors. ERalpha and ERbeta redirected to the cortex in E(2)-created ovaries, while AR medullary expression was transiently reduced. Although warmer incubation temperature and estrogen result in the same endpoint (ovarian development), our results indicate different steroid signaling patterns between temperature- and estrogen-induced feminization. 2007 S. Karger AG, Basel

G protein-coupled receptor 30 (GPR30) mediates gene expression changes and growth response to 17beta-estradiol and selective GPR30 ligand G-1 in ovarian cancer cells.

PubMed

Albanito, Lidia; Madeo, Antonio; Lappano, Rosamaria; Vivacqua, Adele; Rago, Vittoria; Carpino, Amalia; Oprea, Tudor I; Prossnitz, Eric R; Musti, Anna Maria; Andò, Sebastiano; Maggiolini, Marcello

2007-02-15

Estrogens play a crucial role in the development of ovarian tumors; however, the signal transduction pathways involved in hormone action are still poorly defined. The orphan G protein-coupled receptor 30 (GPR30) mediates the nongenomic signaling of 17beta-estradiol (E2) in a variety of estrogen-sensitive cancer cells through activation of the epidermal growth factor receptor (EGFR) pathway. Whether estrogen receptor alpha (ERalpha) also contributes to GPR30/EGFR signaling is less understood. Here, we show that, in ERalpha-positive BG-1 ovarian cancer cells, both E2 and the GPR30-selective ligand G-1 induced c-fos expression and estrogen-responsive element (ERE)-independent activity of a c-fos reporter gene, whereas only E2 stimulated an ERE-responsive reporter gene, indicating that GPR30 signaling does not activate ERalpha-mediated transcription. Similarly, both ligands up-regulated cyclin D1, cyclin E, and cyclin A, whereas only E2 enhanced progesterone receptor expression. Moreover, both GPR30 and ERalpha expression are required for c-fos stimulation and extracellular signal-regulated kinase (ERK) activation in response to either E2 or G-1. Inhibition of the EGFR transduction pathway inhibited c-fos stimulation and ERK activation by either ligand, suggesting that in ovarian cancer cells GPR30/EGFR signaling relays on ERalpha expression. Interestingly, we show that both GPR30 and ERalpha expression along with active EGFR signaling are required for E2-stimulated and G-1-stimulated proliferation of ovarian cancer cells. Because G-1 was able to induce both c-fos expression and proliferation in the ERalpha-negative/GPR30-positive SKBR3 breast cancer cells, the requirement for ERalpha expression in GPR30/EGFR signaling may depend on the specific cellular context of different tumor types.

The cannabinoid receptor CB1 modulates the signaling properties of the lysophosphatidylinositol receptor GPR55.

PubMed

Kargl, Julia; Balenga, Nariman; Parzmair, Gerald P; Brown, Andrew J; Heinemann, Akos; Waldhoer, Maria

2012-12-28

The G protein-coupled receptor (GPCR) 55 (GPR55) and the cannabinoid receptor 1 (CB1R) are co-expressed in many tissues, predominantly in the central nervous system. Seven transmembrane spanning (7TM) receptors/GPCRs can form homo- and heteromers and initiate distinct signaling pathways. Recently, several synthetic CB1 receptor inverse agonists/antagonists, such as SR141716A, AM251, and AM281, were reported to activate GPR55. Of these, SR141716A was marketed as a promising anti-obesity drug, but was withdrawn from the market because of severe side effects. Here, we tested whether GPR55 and CB1 receptors are capable of (i) forming heteromers and (ii) whether such heteromers could exhibit novel signaling patterns. We show that GPR55 and CB1 receptors alter each others signaling properties in human embryonic kidney (HEK293) cells. We demonstrate that the co-expression of FLAG-CB1 receptors in cells stably expressing HA-GPR55 specifically inhibits GPR55-mediated transcription factor activation, such as nuclear factor of activated T-cells and serum response element, as well as extracellular signal-regulated kinases (ERK1/2) activation. GPR55 and CB1 receptors can form heteromers, but the internalization of both receptors is not affected. In addition, we observe that the presence of GPR55 enhances CB1R-mediated ERK1/2 and nuclear factor of activated T-cell activation. Our data provide the first evidence that GPR55 can form heteromers with another 7TM/GPCR and that this interaction with the CB1 receptor has functional consequences in vitro. The GPR55-CB1R heteromer may play an important physiological and/or pathophysiological role in tissues endogenously co-expressing both receptors.

The Cannabinoid Receptor CB1 Modulates the Signaling Properties of the Lysophosphatidylinositol Receptor GPR55*

PubMed Central

Kargl, Julia; Balenga, Nariman; Parzmair, Gerald P.; Brown, Andrew J.; Heinemann, Akos; Waldhoer, Maria

2012-01-01

The G protein-coupled receptor (GPCR) 55 (GPR55) and the cannabinoid receptor 1 (CB1R) are co-expressed in many tissues, predominantly in the central nervous system. Seven transmembrane spanning (7TM) receptors/GPCRs can form homo- and heteromers and initiate distinct signaling pathways. Recently, several synthetic CB1 receptor inverse agonists/antagonists, such as SR141716A, AM251, and AM281, were reported to activate GPR55. Of these, SR141716A was marketed as a promising anti-obesity drug, but was withdrawn from the market because of severe side effects. Here, we tested whether GPR55 and CB1 receptors are capable of (i) forming heteromers and (ii) whether such heteromers could exhibit novel signaling patterns. We show that GPR55 and CB1 receptors alter each others signaling properties in human embryonic kidney (HEK293) cells. We demonstrate that the co-expression of FLAG-CB1 receptors in cells stably expressing HA-GPR55 specifically inhibits GPR55-mediated transcription factor activation, such as nuclear factor of activated T-cells and serum response element, as well as extracellular signal-regulated kinases (ERK1/2) activation. GPR55 and CB1 receptors can form heteromers, but the internalization of both receptors is not affected. In addition, we observe that the presence of GPR55 enhances CB1R-mediated ERK1/2 and nuclear factor of activated T-cell activation. Our data provide the first evidence that GPR55 can form heteromers with another 7TM/GPCR and that this interaction with the CB1 receptor has functional consequences in vitro. The GPR55-CB1R heteromer may play an important physiological and/or pathophysiological role in tissues endogenously co-expressing both receptors. PMID:23161546

Comparative study on the development of intestinal mucin 2, IgA and polymeric Ig receptor expressions between broiler chickens and Pekin ducks

USDA-ARS?s Scientific Manuscript database

Intestinal mucin2 (MUC2), a major gel-forming mucin, represents a primary barrier component of mucus layers and target site for secretory IgA. Polymeric Ig receptor (pIgR) expressed on the basolateral surface of epithelium, is used to transport polymeric IgA from the lamina propria into luminal muci...

Generation and characterization of PDGFRα-GFPCreERT2 knock-In mouse line.

PubMed

Miwa, Hiroyuki; Era, Takumi

2015-05-01

Platelet-derived growth factor (PDGF) and its receptor play an important role in embryogenesis. PDGF receptor α (PDGFRα) is expressed specifically in the embryonic day 7.5 (E7.5) mesoderm and in the E9.5 neural crest among other tissues. PDGFRα-expressing cells and their descendants are involved in the formation of various tissues. To trace PDGFRα-expressing cells in vivo, we generated a knock-in mouse line that expressed a fusion protein of green fluorescent protein (GFP), Cre recombinase (Cre), and mutated estrogen receptor ligand-binding domain (ERT2) under the control of the PDGFRα promoter. In these mice, Cre activity in PDGFRα-expressing cells could be induced by tamoxifen treatment. Taken together, our results suggest that the knock-in mouse line generated here could be useful for studying PDGFRα-expressing cells and their descendants in vivo at various stages of development. © 2015 Wiley Periodicals, Inc.

Old dance with a new partner: EGF receptor as the phenobarbital receptor mediating Cyp2B expression.

PubMed

Meyer, Sharon A; Jirtle, Randy L

2013-05-07

The decades-long quest for the phenobarbital (PhB) receptor that mediates activation of Cyp2B would appear fulfilled with the discovery by Mutoh et al., who found that PhB binds with pharmacological affinity to the epidermal growth factor receptor (EGFR). This finding provides a molecular basis for the suppression of hepatocyte EGFR signaling observed with PhB treatment, as previously noted in the context of tumor promotion. Although the PhB-mediated induction of Cyp2B expression through the association of a canonical nuclear receptor with the 5'-enhancer PBREM of Cyp2B is well known, direct binding of PhB to constitutive active androstane receptor (CAR, also known as NR1I3) typical of other xenobiotic-activated nuclear receptors has eluded detection. One EGF-activated pathway affected by the PhB-EGFR interaction is the loss of tyrosine phosphorylation of the scaffold protein RACK1. Dephosphorylated RACK1 provides the mechanistic link between the binding of PhB to EGFR and its effects on CAR by facilitating the interaction of serine/threonine phosphatase PP2A with inactive phosphorylated CAR. The dephosphorylation of CAR enables its translocation to the nucleus and activation of Cyp2B expression. Because EGFR and transducers RACK1, PP2A, and other partners are highly networked in numerous cellular pathways, this newly discovered partnership will surely reveal new fundamental roles for PhB beyond the regulation of drug metabolism.

Expression Analysis of Dopamine Receptor Subtypes in Normal Human Pituitaries, Nonfunctioning Pituitary Adenomas and Somatotropinomas, and the Association between Dopamine and Somatostatin Receptors with Clinical Response to Octreotide-LAR in Acromegaly

PubMed Central

Neto, Leonardo Vieira; Machado, Evelyn de O.; Luque, Raul M.; Taboada, Giselle F.; Marcondes, Jorge B.; Chimelli, Leila M. C.; Quintella, Leonardo Pereira; Niemeyer, Paulo; de Carvalho, Denise P.; Kineman, Rhonda D.; Gadelha, Mônica R.

2009-01-01

Context: Dopamine receptor (DR) and somatostatin receptor subtype expression in pituitary adenomas may predict the response to postsurgical therapies. Objectives: Our objectives were to assess and compare the mRNA levels of DR1-5 and somatostatin receptors 1–5 in normal pituitaries (NPs), nonfunctioning pituitary adenomas (NFPAs), and somatotropinomas. In addition, we determined whether the level of DR expression correlates with the in vivo response to octreotide-LAR in acromegalic patients. Design and Patients: Eight NPs, 30 NFPAs, and 39 somatotropinomas were analyzed for receptor mRNA levels by real-time RT-PCR. The DR2 short variant was estimated as the DR2 long/DR2 total (DR2T). The relationship between DR expression and the postsurgical response to octreotide-LAR was assessed in 19 of the acromegalic patients. Results: DR3 was not detected. The relationship between expression levels of DR subtypes in NPs and somatotropinomas was DR2T⋙DR4≫DR5>DR1, whereas in NFPAs, DR2T⋙DR4≫DR1>DR5. The DR2 short variant was the predominant DR2 variant in the majority of samples. In acromegalics treated with octreotide-LAR, DR1 was negatively correlated with percent GH reduction (3 months: r = −0.67, P = 0.002; and 6 months: r = −0.58, P = 0.009), and DR5 was positively correlated with percent IGF-I reduction (3 months: r = 0.55, P = 0.01; and 6 months: r = 0.47, P = 0.04). Conclusions: DR2 is the predominant DR subtype in NPs, NFPAs, and somatotropinomas. The fact that DR1, DR4, and DR5 are also expressed in many adenomas tested suggests that these receptors might also play a role in the therapeutic impact of postsurgical medical therapies in patients with NFPA and acromegaly. This was supported by the finding that the in vivo response to octreotide-LAR was negatively associated with DR1 and positively associated with DR5. PMID:19293270

Model-based Analysis of HER Activation in Cells Co-Expressing EGFR, HER2 and HER3.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shankaran, Harish; Zhang, Yi; Tan, Yunbing

2013-08-22

The HER/ErbB family of receptor tyrosine kinases drive critical responses in normal physiology and cancer, and the expression levels of the various HER receptors are critical determinants of clinical outcomes. HER activation is driven by the formation of various dimer complexes between members of this receptor family. The HER dimer types can have differential effects on downstream signaling and phenotypic outcomes. We constructed an integrated mathematical model of HER activation and trafficking to quantitatively link receptor expression levels to dimerization and activation. We parameterized the model with a comprehensive set of HER phosphorylation and abundance data collected in a panelmore » of human mammary epithelial cells expressing varying levels of EGFR, HER2 and HER3. Although parameter estimation yielded multiple solutions, predictions for dimer phosphorylation were in agreement with each other. We validated the model using experiments where pertuzumab was used to block HER2 dimerization. We used the model to predict HER dimerization and activation patterns in a panel of epithelial cells lines with known HER expression levels. Simulations over the range of expression levels seen in various cell lines indicate that: i) EGFR phosphorylation is driven by HER1/1 and HER1/2 dimers, and not HER1/3 dimers, ii) HER1/2 and HER2/3 dimers both contribute significantly to HER2 activation with the EGFR expression level determining the relative importance of these species, and iii) the HER2/3 dimer is largely responsible for HER3 activation. The model can be used to predict phosphorylated dimer levels for any given HER expression profile. This information in turn can be used to quantify the potencies of the various HER dimers, and can potentially inform personalized therapeutic approaches.« less

Mutual enhancement of IL-2 and IL-7 on DNA vaccine immunogenicity mainly involves regulations on their receptor expression and receptor-expressing lymphocyte generation.

PubMed

Zhang, Yonghong; Liang, Shuang; Li, Xiujin; Wang, Liyue; Zhang, Jianlou; Xu, Jian; Huo, Shanshan; Cao, Xuebin; Zhong, Zhenyu; Zhong, Fei

2015-07-09

Our previous study showed that IL-2 and IL-7 could mutually enhance the immunogenicity of canine parvovirus VP2 DNA vaccine, although the underlying mechanism remained unknown. Here, we used the OVA gene as a DNA vaccine in a mouse model to test their enhancement on DNA vaccine immunogenicity and to explore the molecular mechanism. Results showed that both IL-2 and IL-7 genes significantly increased the immunogenicity of OVA DNA vaccine in mice. Co-administration of IL-2 and IL-7 genes with OVA DNA significantly increased OVA-specific antibody titers, T cell proliferation and IFN-γ production compared with IL-2 or IL-7 alone, confirming that IL-2 and IL-7 mutually enhanced DNA vaccine immunogenicity. Mechanistically, we have shown that IL-2 significantly stimulated generation of IL-7 receptor-expressing lymphocytes, and that IL-7 significantly induced IL-2 receptor expression. These results contribute to an explanation of the mechanism of the mutual effects of IL-2 and IL-7 on enhancing DNA vaccine immunogenicity and provided a basis for further investigation on their mutual effects on adjuvant activity and immune regulation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Type-I interferon receptor expression: its circadian rhythm and downregulation after interferon-alpha administration in peripheral blood cells from renal cancer patients.

PubMed

Shiba, Masahiro; Nonomura, Norio; Nakai, Yasutomo; Nakayama, Masashi; Takayama, Hitoshi; Inoue, Hitoshi; Tsujimura, Akira; Nishimura, Kazuo; Okuyama, Akihiko

2009-04-01

To investigate the regulation of interferon-alpha (IFN-alpha) receptor expression in metastatic renal cell carcinoma (RCC) after IFN-alpha administration. Blood sampling was carried out in eight patients with metastatic RCC and six healthy volunteers. Flow-cytometric analysis using a monoclonal antibody against the active subunit of the type-I IFN-alpha receptor (IFNAR2) was carried out to examine the circadian rhythm of IFNAR2 expression in peripheral blood mononuclear cells (PBMC) as well as its downregulation after IFN-alpha administration. According to its circadian rhythm IFNAR2 in PBMC had a peak expression at night. Once IFN-alpha is administered, IFNAR2 levels in PBMC showed downregulation within 48 h and recovered within another 48 h. Our findings might support the establishment of an optimal schedule for IFN-alpha administration.

Prefrontal mRNA expression of long and short isoforms of D2 dopamine receptor: Possible role in delayed learning deficit caused by early life interleukin-1β treatment.

PubMed

Schwarz, Alexander P; Trofimov, Alexander N; Zubareva, Olga E; Lioudyno, Victoria I; Kosheverova, Vera V; Ischenko, Alexander M; Klimenko, Victor M

2017-08-30

Long (D2L) and short (D2S) isoform of the D2 dopamine receptor are believed to play different roles in behavioral regulation. However, little is known about differential regulation of these isoforms mRNA expression during the process of learning in physiological and pathological states. In this study, we have investigated the combined effect of training in active avoidance (AA) paradigm and chronic early life treatment with pro-inflammatory cytokine interleukin (IL)-1β (1μg/kg i.p., P15-21) on D2S and D2L dopamine receptor mRNA expression in the medial prefrontal cortex (mPFC) of adult rats. We have shown differential regulation of D2 short and long mRNA isoform expression in the mPFC. There was no effect of AA-training on D2S mRNA expression, while D2L mRNA was downregulated in AA-trained control (intact and saline-treated) animals, and this effect was not observed in rats treated with IL-1β. D2S mRNA expression level negatively correlated with learning ability within control (saline-treated and intact) groups but not in IL-1β-treated animals. Thus, prefrontal expression of distinct D2 dopamine receptor splice variants is supposed to be implicated in cognitive decline caused by early life immune challenge. Copyright © 2017 Elsevier B.V. All rights reserved.

Changes of imidazoline receptors in spontaneously hypertensive rats

PubMed Central

Mar, Guang-Yuan; Chou, Ming-Ting; Chung, Hsien-Hui; Chiu, Nien-Hua; Chen, Mei-Fen; Cheng, Juei-Tang

2013-01-01

The role of imidazoline receptors in the regulation of vascular function remains unclear. In this study, we evaluated the effect of agmatine, an imidazoline receptor agonist, on systolic blood pressure (SBP) in spontaneously hypertensive rats (SHRs) and investigated the expressions of imidazoline receptors by Western blot. The isometric tension of aortic rings isolated from male SHRs was also estimated. Agmatine decreased SBP in a dose-dependent manner in SHRs but not in the normal group [Wistar–Kyoto (WKY) rats]. This reduction in SBP in SHRs was abolished by BU224, a selective antagonist of imidazoline I2-receptors. Higher expression of imidazoline receptors in SHR was observed. Moreover, agmatine-induced relaxation in isolated aortic rings precontracted with phenylephrine or KCl. This relaxation was also abolished by BU224 but was not modified by efaroxan, an imidazoline I1-receptor antagonist. Agmatine-induced relaxation was also attenuated by PNU 37883, a selective blocker of vascular ATP-sensitive potassium (KATP) channels. Additionally, vasodilatation by agmatine was reduced by an inhibitor of protein kinase A (PKA). We suggest that agmatine can lower blood pressure in SHRs through activation of the peripheral imidazoline I2-receptor, which is expressed more highly in SHRs. PMID:23176371

Functional expression of calcium-permeable canonical transient receptor potential 4-containing channels promotes migration of medulloblastoma cells.

PubMed

Wei, Wei-Chun; Huang, Wan-Chen; Lin, Yu-Ping; Becker, Esther B E; Ansorge, Olaf; Flockerzi, Veit; Conti, Daniele; Cenacchi, Giovanna; Glitsch, Maike D

2017-08-15

The proton sensing ovarian cancer G protein coupled receptor 1 (OGR1, aka GPR68) promotes expression of the canonical transient receptor potential channel subunit TRPC4 in normal and transformed cerebellar granule precursor (DAOY) cells. OGR1 and TRPC4 are prominently expressed in healthy cerebellar tissue throughout postnatal development and in primary cerebellar medulloblastoma tissues. Activation of TRPC4-containing channels in DAOY cells, but not non-transformed granule precursor cells, results in prominent increases in [Ca 2+ ] i and promotes cell motility in wound healing and transwell migration assays. Medulloblastoma cells not arising from granule precursor cells show neither prominent rises in [Ca 2+ ] i nor enhanced motility in response to TRPC4 activation unless they overexpressTRPC4. Our results suggest that OGR1 enhances expression of TRPC4-containing channels that contribute to enhanced invasion and metastasis of granule precursor-derived human medulloblastoma. Aberrant intracellular Ca 2+ signalling contributes to the formation and progression of a range of distinct pathologies including cancers. Rises in intracellular Ca 2+ concentration occur in response to Ca 2+ influx through plasma membrane channels and Ca 2+ release from intracellular Ca 2+ stores, which can be mobilized in response to activation of cell surface receptors. Ovarian cancer G protein coupled receptor 1 (OGR1, aka GPR68) is a proton-sensing G q -coupled receptor that is most highly expressed in cerebellum. Medulloblastoma (MB) is the most common paediatric brain tumour that arises from cerebellar precursor cells. We found that nine distinct human MB samples all expressed OGR1. In both normal granule cells and the transformed human cerebellar granule cell line DAOY, OGR1 promoted expression of the proton-potentiated member of the canonical transient receptor potential (TRPC) channel family, TRPC4. Consistent with a role for TRPC4 in MB, we found that all MB samples also expressed TRPC4. In DAOY cells, activation of TRPC4-containing channels resulted in large Ca 2+ influx and enhanced migration, while in normal cerebellar granule (precursor) cells and MB cells not derived from granule precursors, only small levels of Ca 2+ influx and no enhanced migration were observed. Our results suggest that OGR1-dependent increases in TRPC4 expression may favour formation of highly Ca 2+ -permeable TRPC4-containing channels that promote transformed granule cell migration. Increased motility of cancer cells is a prerequisite for cancer invasion and metastasis, and our findings may point towards a key role for TRPC4 in progression of certain types of MB. © 2017 The Authors. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.

Chronic lead exposure enhances the sympathoexcitatory response associated with P2X4 receptor in rat stellate ganglia.

PubMed

Zhu, Gaochun; Chen, Zhenying; Dai, Bo; Zheng, Chaoran; Jiang, Huaide; Xu, Yurong; Sheng, Xuan; Guo, Jingjing; Dan, Yu; Liang, Shangdong; Li, Guilin

2018-06-01

Chronic lead exposure causes peripheral sympathetic nerve stimulation, including increased blood pressure and heart rate. Purinergic receptors are involved in the sympathoexcitatory response induced by myocardial ischemia injury. However, whether P2X4 receptor participates in sympathoexcitatory response induced by chronic lead exposure and the possible mechanisms are still unknown. The aim of this study was to explore the change of the sympathoexcitatory response induced by chronic lead exposure via the P2X4 receptor in the stellate ganglion (SG). Rats were given lead acetate through drinking water freely at doses of 0 g/L (control group), 0.5 g/L (low lead group), and 2 g/L (high lead group) for 1 year. Our results demonstrated that lead exposure caused autonomic nervous dysfunction, including blood pressure and heart rate increased and heart rate variability (HRV) decreased. Western blotting results indicated that after lead exposure, the protein expression levels in the SG of P2X4 receptor, IL-1β and Cx43 were up-regulated, the phosphorylation of p38 mitogen-activated protein kinase (MAPK) was activated. Real-time PCR results showed that the mRNA expression of P2X4 receptor in the SG was higher in lead exposure group than that in the control group. Double-labeled immunofluorescence results showed that P2X4 receptor was co-expressed with glutamine synthetase (GS), the marker of satellite glial cells (SGCs). These changes were positively correlated with the dose of lead exposure. The up-regulated expression of P2X4 receptor in SGCs of the SG maybe enhance the sympathoexcitatory response induced by chronic lead exposure. © 2018 Wiley Periodicals, Inc.

Changes in myometrial expression of progesterone receptor membrane components 1 and 2 are associated with human parturition at term.

PubMed

Wang, Ray; Sheehan, Penelope M; Brennecke, Shaun P

2016-04-01

While the exact mechanism of human parturition remains unknown, functional progesterone withdrawal is believed to play a key regulatory role. Progesterone receptor membrane components 1 and 2 (PGRMC1, PGRMC2) are putative progesterone receptors and the aim of this project was to investigate their expression in human myometrium. Human term myometrium was obtained from the lower uterine segment incision in women undergoing elective (not-in-labour, NIL; n=11) and emergency Caesarean sections (in-labour, IL; n=10), following written consent. PGRMC1 and 2 expression was quantified using real-time reverse transcription polymerase chain reaction and western blot. Subcellular localisation was performed by immunohistochemistry and immunofluorescence. There was a significant decrease in PGRMC1 mRNA (P=0.0317) and protein expression (P=0.0151) in IL myometrium, compared with NIL myometrium. PGRMC2 mRNA expression (P=0.0151) was also decreased in IL myometrium, compared with NIL myometrium. Immunostaining studies confirmed the presence of PGRMC1 and 2 in smooth-muscle cells. Expression was perinuclear in NIL myometrium and more generalised and cytoplasmic in IL myometrium. The decrease in PGRMC1 expression and the translocation away from a perinuclear location for both PGRMC1 and 2 could contribute to a functional progesterone withdrawal that may ultimately initiate parturition.

Nuclear receptors in pancreatic tumor cells.

PubMed

Damaskos, Christos; Garmpis, Nikolaos; Karatzas, Theodore; Kostakis, Ioannis D; Nikolidakis, Lampros; Kostakis, Alkiviadis; Kouraklis, Gregory

2014-12-01

This review focuses on nuclear receptors expressed in pancreatic cancer. An extensive search of articles published up to March 2013 was conducted using the MEDLINE database. The key words used were "pancreatic cancer", "molecular receptors" and "growth factors". A total of 112 articles referred to pancreatic cancer, molecular receptors and/or growth factors were included. Receptors of growth factors, such as the epithelial growth factor receptor, insulin-like growth factor-1 receptor, vascular endothelial growth factor receptor and others, such as integrin α5β1, somatostatin receptors, the death receptor 5, claudin, notch receptors, mesothelin receptors, follicle-stimulating hormone receptors, the MUC1 receptor, the adrenomedullin receptor, the farnesoid X receptor, the transferrin receptor, sigma-2 receptors, the chemokine receptor CXCR4, the urokinase plasminogen activator receptor, the ephrine A2 receptor, the GRIA3 receptor, the RON receptor and the angiotensin II receptor AT-1 are expressed in pancreatic tumor cells. These molecules are implicated in tumor growth, apoptosis, angiogenesis, metastasis etc. After identifying the molecular receptors associated with the pancreatic cancer, many more target molecules playing important roles in tumor pathophysiology and senescence-associated signal transduction in cancer cells will be identified. This may have a significant influence on diagnosis, therapy and prognosis of pancreatic cancer. Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Decreased VIP and VPAC2 receptor expression in the biological clock of the R6/2 Huntington's disease mouse.

PubMed

Fahrenkrug, Jan; Popovic, Natalija; Georg, Birgitte; Brundin, Patrik; Hannibal, Jens

2007-01-01

Huntington's disease (HD) is a fatal genetic neurodegenerative disorder caused by a CAG triplet repeat expansion in the gene encoding the protein huntingtin. The most studied model of HD, the R6/2 transgenic mouse, replicates many features of the disease. In addition to motor, cognitive, and endocrine dysfunctions, these mice exhibit a progressive disruption of circadian rhythms. This is accompanied by an altered expression of the circadian clock genes in the suprachiasmatic nucleus/nuclei (SCN), the principal circadian pacemaker in the brain. The neuropeptide vasoactive intestinal polypeptide (VIP) and its receptor VPAC2 are highly expressed in the SCN, and VIPergic signaling plays an essential role in maintenance of ongoing circadian rhythmicity. We found a marked reduction in both VIP mRNA and VPAC2 receptor mRNA, quantified by RT-PCR, as well as a decrease in VIP immunostaining in the SCN of R6/2 mice. These changes were coupled to a disruption of circadian rhythm. We observed no loss of neurons in the SCN and therefore suggest that the changes in VIP and VPAC2 receptor are due to their decreased expression. In conclusion, we propose that impaired VIPergic signaling is an additional candidate mechanism for disruption of circadian rhythms in R6/2 mice.

Immunostimulatory CpG-oligonucleotides induce functional high affinity IL-2 receptors on B-CLL cells: costimulation with IL-2 results in a highly immunogenic phenotype.

PubMed

Decker, T; Schneller, F; Kronschnabl, M; Dechow, T; Lipford, G B; Wagner, H; Peschel, C

2000-05-01

CpG-oligodeoxynucleotides (CpG-ODN) have been shown to induce proliferation, cytokine production, and surface molecule regulation in normal and malignant human B cells. In the present study, we investigated the potential of CpG-ODN to induce functional high-affinity receptors in leukemic and normal B cells and the effects of costimulation with IL-2 on proliferation, cytokine secretion, and surface molecule regulation. Highly purified B cells from B-CLL patients and normal controls were stimulated with CpG-ODN with or without IL-2. Expression of CD25 was determined using FACS, and the presence of high-affinity IL-2 receptors was determined by scatchard analysis. Costimulatory effects of IL-2 and CpG-ODN were investigated using proliferation assays, ELISA (IL-6, TNF-alpha), and FACS analysis (CD80, CD86 expression). Reactivity of autologous and allogeneic T cells toward activated B-CLL cells was determined in mixed lymphocyte reactions and Interferon-gamma Elispot assays. The CpG-ODN DSP30 caused a significantly stronger induction of the IL-2 receptor alpha chain in malignant as compared with normal B cells (p = 0.03). This resulted in the expression of functional high-affinity IL-2 receptors in B-CLL cells, but fewer numbers of receptors with less affinity were expressed in normal B cells. Although addition of IL-2 to CpG-ODN-stimulated cells augmented proliferation in both normal B cells and B-CLL cells, no costimulatory effect on cytokine production or surface molecule expression could be observed in normal B cells. In contrast, TNF-alpha and IL-6 production was increased in B-CLL cells, and the expression of CD80 and CD86 was further enhanced when IL-2 was used as a costimulus. Autologous and allogeneic immune recognition of B-CLL cells stimulated with CpG-ODN and IL-2 was increased compared with B-CLL cells stimulated with CpG-ODN alone. Stimulation of B-CLL cells with CpG-ODN and IL-2 might be an attractive strategy for potential immunotherapies for B-CLL patients.

Defective postnatal endochondral bone development by chondrocyte-specific targeted expression of parathyroid hormone type 2 receptor.

PubMed

Panda, Dibyendu Kumar; Goltzman, David; Karaplis, Andrew C

2012-12-15

The human parathyroid hormone type 2 receptor (PTH2R) is activated by PTH and by tuberoinfundibular peptide of 39 residues (TIP39), the latter likely acting as its natural ligand. Although the receptor is expressed at highest levels in the nervous system, we have observed that both PTH2R and TIP39 are expressed in the newborn mouse growth plate, with the receptor localizing in the resting zone and the ligand TIP39 localizing exclusively in prehypertrophic and hypertrophic chondrocytes. To address the role of PTH2R in postnatal skeletal growth and development, Col2a1-hPTH2R (PTH2R-Tg) transgenic mice were generated. The mice were viable and of nearly normal size at birth. Expression of the transgene in the growth plate was limited to chondrocytes. We found that chondrocyte proliferation was decreased, as determined by in vivo BrdU labeling of proliferating chondrocytes and CDK4 and p21 expression in the growth plate of Col2a1-hPTH2R transgenic mice. Similarly, the differentiation and maturation of chondrocytes was delayed, as characterized by decreased Sox9 expression and weaker immunostaining for the chondrocyte differentiation markers collagen type II and type X and proteoglycans. As well, there was altered expression of Gdf5, Wdr5, and β-catenin, factors implicated in chondrocyte maturation, proliferation, and differentiation.These effects impacted on the process of endochondral ossification, resulting in delayed formation of the secondary ossification center, and diminished trabecular bone volume. The findings substantiate a role for PTH2R signaling in postnatal growth plate development and subsequent bone mass acquisition.

Cloning, phylogeny, and regional expression of a Y5 receptor mRNA in the brain of the sea lamprey (Petromyzon marinus).

PubMed

Pérez-Fernández, Juan; Megías, Manuel; Pombal, Manuel A

2014-04-01

The NPY receptors known as Y receptors are classified into three subfamilies, Y1, Y2, and Y5, and are involved in different physiological functions. The Y5 receptor is the only member of the Y5 subfamily, and it is present in all vertebrate groups, except for teleosts. Both molecular and pharmacological studies show that Y5 receptor is highly conserved during vertebrate evolution. Furthermore, this receptor is widely expressed in the mammalian brain, including the hypothalamus, where it is thought to take part in feeding and homeostasis regulation. Lampreys belong to the agnathan lineage, and they are thought to have branched out between the two whole-genome duplications that occurred in vertebrates. Therefore, they are in a key position for studies on the evolution of gene families in vertebrates. Here we report the cloning, phylogeny, and brain expression pattern of the sea lamprey Y5 receptor. In phylogenetic studies, the lamprey Y5 receptor clusters in a basal position, together with Y5 receptors of other vertebrates. The mRNA of this receptor is broadly expressed in the lamprey brain, being especially abundant in hypothalamic areas. Its expression pattern is roughly similar to that reported for other vertebrates and parallels the expression pattern of the Y1 receptor subtype previously described by our group, as it occurs in mammals. Altogether, these results confirm that a Y5 receptor is present in lampreys, thus being highly conserved during the evolution of vertebrates, and suggest that it is involved in many brain functions, the only known exception being teleosts. Copyright © 2013 Wiley Periodicals, Inc.

Adenosine A₂A receptors inhibit delayed rectifier potassium currents and cell differentiation in primary purified oligodendrocyte cultures.

PubMed

Coppi, Elisabetta; Cellai, Lucrezia; Maraula, Giovanna; Pugliese, Anna Maria; Pedata, Felicita

2013-10-01

Oligodendrocyte progenitor cells (OPCs) are a population of cycling cells which persist in the adult central nervous system (CNS) where, under opportune stimuli, they differentiate into mature myelinating oligodendrocytes. Adenosine A(2A) receptors are Gs-coupled P1 purinergic receptors which are widely distributed throughout the CNS. It has been demonstrated that OPCs express A(2A) receptors, but their functional role in these cells remains elusive. Oligodendrocytes express distinct voltage-gated ion channels depending on their maturation. Here, by electrophysiological recordings coupled with immunocytochemical labeling, we studied the effects of adenosine A(2A) receptors on membrane currents and differentiation of purified primary OPCs isolated from the rat cortex. We found that the selective A(2A) agonist, CGS21680, inhibits sustained, delayed rectifier, K(+) currents (I(K)) without modifying transient (I(A)) conductances. The effect was observed in all cells tested, independently from time in culture. CGS21680 inhibition of I(K) current was concentration-dependent (10-200 nM) and blocked in the presence of the selective A(2A) antagonist SCH58261 (100 nM). It is known that I(K) currents play an important role during OPC development since their block decreases cell proliferation and differentiation. In light of these data, our further aim was to investigate whether A(2A) receptors modulate these processes. CGS21680, applied at 100 nM in the culture medium of oligodendrocyte cultures, inhibits OPC differentiation (an effect prevented by SCH58261) without affecting cell proliferation. Data demonstrate that cultured OPCs express functional A(2A) receptors whose activation negatively modulate I(K) currents. We propose that, by this mechanism, A(2A) adenosine receptors inhibit OPC differentiation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Piracy of PGE2/EP receptor mediated signaling by Kaposi’s sarcoma associated herpes virus (KSHV/HHV-8) for latency gene expression: Strategy of a successful pathogen

PubMed Central

Paul, Arun George; Sharma-Walia, Neelam; Kerur, Nagaraj; White, Carl; Chandran, Bala

2010-01-01

KSHV is implicated in the pathogenesis of KS, a chronic inflammation associated malignancy. COX-2 and its metabolite PGE2, two pivotal proinflammatory/oncogeneic molecules, are proposed to play roles in the expression of major KSHV latency associated nuclear antigen-1 (LANA-1). Microsomal prostaglandin E2 synthase (mPGES), PGE2 and its receptors (EP1, EP2, EP3, and EP4) were detected in KS lesions with the distinct staining of EP2/EP4 in KS lesions. In latently infected endothelial TIVE-LTC cells, EP receptor antagonists down-regulated LANA-1 expression as well as Ca2+, p-Src, p-PI3K, p-PKCζ/λ, and p-NF-κB, which are also some of the signal molecules proposed to be important in KS pathogenesis. Exogenous PGE2 and EP receptor agonists induced the LANA-1 promoter in 293 cells, and YY1, Sp1, Oct-1, Oct-6, C/EBP and c-Jun transcription factors appear to be involved in this induction. PGE2/EP receptor induced LANA-1 promoter activity was down-regulated significantly by the inhibition of Ca2+, p-Src, p-PI3K, p-PKCζ/λ, and p-NF-κB. These findings implicate the inflammatory PGE2/EP receptors and the associated signal molecules in herpes virus latency and uncover a novel paradigm that demonstrates the evolution of KSHV genome plasticity to utilize inflammatory response for its survival advantage of maintaining latent gene expression. This data also suggests that potential use of anti-COX-2 and anti-EP receptor therapy may not only ameliorate the chronic inflammation associated with KS but could also lead to elimination of the KSHV latent infection and the associated KS lesions. PMID:20388794

Bisphenol A influences oestrogen- and thyroid hormone-regulated thyroid hormone receptor expression in rat cerebellar cell culture.

PubMed

Somogyi, Virág; Horváth, Tamás L; Tóth, István; Bartha, Tibor; Frenyó, László Vilmos; Kiss, Dávid Sándor; Jócsák, Gergely; Kerti, Annamária; Naftolin, Frederick; Zsarnovszky, Attila

2016-12-01

Thyroid hormones (THs) and oestrogens are crucial in the regulation of cerebellar development. TH receptors (TRs) mediate these hormone effects and are regulated by both hormone families. We reported earlier that THs and oestradiol (E 2 ) determine TR levels in cerebellar cell culture. Here we demonstrate the effects of low concentrations (10 -10 M) of the endocrine disruptor (ED) bisphenol A (BPA) on the hormonal (THs, E 2 ) regulation of TRα,β in rat cerebellar cell culture. Primary cerebellar cell cultures, glia-containing and glia-destroyed, were treated with BPA or a combination of BPA and E 2 and/or THs. Oestrogen receptor and TH receptor mRNA and protein levels were determined by real-time qPCR and Western blot techniques. The results show that BPA alone decreases, while BPA in combination with THs and/or E 2 increases TR mRNA expression. In contrast, BPA alone increased receptor protein expressions, but did not further increase them in combination with THs and/or E 2 . The modulatory effects of BPA were mediated by the glia; however, the degree of changes also depended on the specific hormone ligand used. The results signify the importance of the regulatory mechanisms interposed between transcription and translation and raise the possibility that BPA could act to influence nuclear hormone receptor levels independently of ligand-receptor interaction.

Enhancement of Adipocyte Browning by Angiotensin II Type 1 Receptor Blockade.

PubMed

Tsukuda, Kana; Mogi, Masaki; Iwanami, Jun; Kanno, Harumi; Nakaoka, Hirotomo; Wang, Xiao-Li; Bai, Hui-Yu; Shan, Bao-Shuai; Kukida, Masayoshi; Higaki, Akinori; Yamauchi, Toshifumi; Min, Li-Juan; Horiuchi, Masatsugu

2016-01-01

Browning of white adipose tissue (WAT) has been highlighted as a new possible therapeutic target for obesity, diabetes and lipid metabolic disorders, because WAT browning could increase energy expenditure and reduce adiposity. The new clusters of adipocytes that emerge with WAT browning have been named 'beige' or 'brite' adipocytes. Recent reports have indicated that the renin-angiotensin system (RAS) plays a role in various aspects of adipose tissue physiology and dysfunction. The biological effects of angiotensin II, a major component of RAS, are mediated by two receptor subtypes, angiotensin II type 1 receptor (AT1R) and type 2 receptor (AT2R). However, the functional roles of angiotensin II receptor subtypes in WAT browning have not been defined. Therefore, we examined whether deletion of angiotensin II receptor subtypes (AT1aR and AT2R) may affect white-to-beige fat conversion in vivo. AT1a receptor knockout (AT1aKO) mice exhibited increased appearance of multilocular lipid droplets and upregulation of thermogenic gene expression in inguinal white adipose tissue (iWAT) compared to wild-type (WT) mice. AT2 receptor-deleted mice did not show miniaturization of lipid droplets or alteration of thermogenic gene expression levels in iWAT. An in vitro experiment using adipose tissue-derived stem cells showed that deletion of the AT1a receptor resulted in suppression of adipocyte differentiation, with reduction in expression of thermogenic genes. These results indicate that deletion of the AT1a receptor might have some effects on the process of browning of WAT and that blockade of the AT1 receptor could be a therapeutic target for the treatment of metabolic disorders.

Expression of Inappropriate Cadherins in Human Breast Carcinomas

DTIC Science & Technology

2000-10-01

fibroblast growth factor receptor ADHERINS constitute a family of transmembrane Hamaguchi et al., 1993). In addition, p120ct", originally...1994. expression is associated with poor prognosis in patients with prostate cancer. Alternative splicing in fibroblast growth factor receptor 2 is... fibroblast growth factor receptor signaling. This year we report that the extracellular domain of N-cadherin is responsible for this

IL-6 Overexpression in ERG-Positive Prostate Cancer Is Mediated by Prostaglandin Receptor EP2.

PubMed

Merz, Constanze; von Mässenhausen, Anne; Queisser, Angela; Vogel, Wenzel; Andrén, Ove; Kirfel, Jutta; Duensing, Stefan; Perner, Sven; Nowak, Michael

2016-04-01

Prostate cancer is the most diagnosed cancer in men and multiple risk factors and genetic alterations have been described. The TMPRSS2-ERG fusion event and the overexpression of the transcription factor ERG are present in approximately 50% of all prostate cancer patients, however, the clinical outcome is still controversial. Prostate tumors produce various soluble factors, including the pleiotropic cytokine IL-6, regulating cellular processes such as proliferation and metastatic segregation. Here, we used prostatectomy samples in a tissue microarray format and analyzed the co-expression and the clinicopathologic data of ERG and IL-6 using immunohistochemical double staining and correlated the read-out with clinicopathologic data. Expression of ERG and IL-6 correlated strongly in prostate tissue samples. Forced expression of ERG in prostate tumor cell lines resulted in significantly increased secretion of IL-6, whereas the down-regulation of ERG decreased IL-6 secretion. By dissecting the underlying mechanism in prostate tumor cell lines we show the ERG-mediated up-regulation of the prostanoid receptors EP2 and EP3. The prostanoid receptor EP2 was overexpressed in human prostate cancer tissue. Furthermore, the proliferation rate and IL-6 secretion in DU145 cells was reduced after treatment with EP2-receptor antagonist. Collectively, our study shows that the expression of ERG in prostate cancer is linked to the expression of IL-6 mediated by the prostanoid receptor EP2. Copyright © 2016 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

NOD2 Modulates Serotonin Transporter and Interacts with TLR2 and TLR4 in Intestinal Epithelial Cells.

PubMed

Layunta, Elena; Latorre, Eva; Forcén, Raquel; Grasa, Laura; Castro, Marta; Arias, Maykel A; Alcalde, Ana I; Mesonero, José Emilio

2018-06-15

Serotonin (5-HT) is a chief modulator of intestinal activity. The effects of 5-HT depend on its extracellular availability, which is mainly controlled by serotonin transporter (SERT), expressed in enterocytes. On the other hand, innate immunity, mediated by Toll-like receptors (TLRs) and nucleotide oligomerization domain (NOD)-like receptors (NLRs), is known to control intestinal microbiota and maintain intestinal homeostasis. The dysregulation of the intestinal serotonergic system and innate immunity has been observed in inflammatory bowel diseases (IBD), the incidence of which has severely increased all over the world. The aim of the present study, therefore, was to analyze the effect of NOD2 on intestinal SERT activity and expression, as well as to study the crosstalk of NOD2 with TLR2 and TLR4. Intestinal epithelial cell line Caco-2/TC7 was used to analyze SERT activity and SERT, NOD2, TLR2 and TLR4 molecular expression by real-time PCR and western blotting. Moreover, intestinal tract (ileum and colon) from mice deficient in TLR2, TLR4 or TLR2/4 receptors was used to test the interdependence of NOD2 with these TLR receptors. NOD2 activation inhibits SERT activity in Caco-2/TC7 cells, mainly due to the decrement of SERT molecular expression, with RIP2/RICK being the intracellular pathway involved in this effect. This inhibitory effect on SERT would yield an increment of extracellular 5-HT availability. In this sense, 5-HT strongly inhibits NOD2 expression. In addition, NOD2 showed greater interdependence with TLR2 than with TLR4. Indeed, NOD2 expression significantly increased in both cells treated with TLR2 agonists and the intestinal tract of Tlr2-/- mice. It may be inferred from our data that NOD2 could play a role in intestinal pathophysiology not only through its inherent innate immune role but also due to its interaction with other receptors as TLR2 and the modulation of the intestinal serotonergic system decreasing SERT activity and expression. © 2018 The Author(s). Published by S. Karger AG, Basel.

A Novel Regulatory Function of Sweet Taste-Sensing Receptor in Adipogenic Differentiation of 3T3-L1 Cells

PubMed Central

Masubuchi, Yosuke; Nakagawa, Yuko; Ma, Jinhui; Sasaki, Tsutomu; Kitamura, Tadahiro; Yamamoto, Yoritsuna; Kurose, Hitoshi; Kojima, Itaru; Shibata, Hiroshi

2013-01-01

Background Sweet taste receptor is expressed not only in taste buds but also in nongustatory organs such as enteroendocrine cells and pancreatic beta-cells, and may play more extensive physiological roles in energy metabolism. Here we examined the expression and function of the sweet taste receptor in 3T3-L1 cells. Methodology/Principal Findings In undifferentiated preadipocytes, both T1R2 and T1R3 were expressed very weakly, whereas the expression of T1R3 but not T1R2 was markedly up-regulated upon induction of differentiation (by 83.0 and 3.8-fold, respectively at Day 6). The α subunits of Gs (Gαs) and G14 (Gα14) but not gustducin were expressed throughout the differentiation process. The addition of sucralose or saccharin during the first 48 hours of differentiation considerably reduced the expression of peroxisome proliferator activated receptor γ (PPARγ and CCAAT/enhancer-binding protein α (C/EBPα at Day 2, the expression of aP2 at Day 4 and triglyceride accumulation at Day 6. These anti-adipogenic effects were attenuated by short hairpin RNA-mediated gene-silencing of T1R3. In addition, overexpression of the dominant-negative mutant of Gαs but not YM-254890, an inhibitor of Gα14, impeded the effects of sweeteners, suggesting a possible coupling of Gs with the putative sweet taste-sensing receptor. In agreement, sucralose and saccharin increased the cyclic AMP concentration in differentiating 3T3-L1 cells and also in HEK293 cells heterologously expressing T1R3. Furthermore, the anti-adipogenic effects of sweeteners were mimicked by Gs activation with cholera toxin but not by adenylate cyclase activation with forskolin, whereas small interfering RNA-mediated knockdown of Gαs had the opposite effects. Conclusions 3T3-L1 cells express a functional sweet taste-sensing receptor presumably as a T1R3 homomer, which mediates the anti-adipogenic signal by a Gs-dependent but cAMP-independent mechanism. PMID:23336004

Expression of adrenomedullin 2/intermedin in human adrenal tumors and attached non-neoplastic adrenal tissues.

PubMed

Morimoto, Ryo; Satoh, Fumitoshi; Murakami, Osamu; Hirose, Takuo; Totsune, Kazuhito; Imai, Yutaka; Arai, Yoichi; Suzuki, Takashi; Sasano, Hironobu; Ito, Sadayoshi; Takahashi, Kazuhiro

2008-07-01

Adrenomedullin 2/intermedin (AM2/IMD) is a new member of calcitonin/calcitonin gene-related peptide family. AM is expressed in various tumors including adrenocortical tumors and modulates tumor growth. The AM2/IMD expression has not been studied, however, in adrenal tumors. The expression of AM2/IMD and AM was therefore studied in human adrenal tumors and attached non-neoplastic adrenal tissues by immunocytochemistry (ICC). Immunoreactive (IR)-AM2/IMD was measured by RIA. Furthermore, the expression of AM2/IMD and its receptor components, calcitonin receptor-like receptor (CRLR), and receptor activity-modifying proteins (RAMPs) 1, 2, and 3 mRNA in these tissues was studied by reverse transcription PCR (RT-PCR). ICC showed that AM2/IMD and AM immunoreactivities were localized in adrenocortical tumors and pheochromocytomas. AM2/IMD and AM immunoreactivities were detected in medulla of attached non-neoplastic tissues, while the degree of immunoreactivity for AM2/IMD and AM in cortices of attached adrenals was relatively weak or undetectable. RIA detected IR-AM2/IMD in adrenal tumors (0.414+/-0.12 to 0.786+/-0.27 pmol/g wet weight, mean+/-S.E.M.) and attached adrenal tissues (0.397+/-0.052 pmol/g wet weight). Reverse-phase high-performance liquid chromatography showed one broad peak eluted in the similar position to synthetic AM2/IMD with several minor peaks. RT-PCR showed expression of AM2/IMD, CRLR, and RAMP1, RAMP2, and RAMP3 mRNA in tissues of adrenal tumors and attached adrenal glands. In conclusion, AM2/IMD is expressed in human adrenal tumors and attached non-neoplastic adrenal tissues and may play (patho-)physiological roles in normal and neoplastic adrenals as an autocrine/paracrine regulator.

Investigation of potential mechanisms regulating protein expression of hepatic pyruvate dehydrogenase kinase isoforms 2 and 4 by fatty acids and thyroid hormone.

PubMed

Holness, Mark J; Bulmer, Karen; Smith, Nicholas D; Sugden, Mary C

2003-02-01

Liver contains two pyruvate dehydrogenase kinases (PDKs), namely PDK2 and PDK4, which regulate glucose oxidation through inhibitory phosphorylation of the pyruvate dehydrogenase complex (PDC). Starvation increases hepatic PDK2 and PDK4 protein expression, the latter occurring, in part, via a mechanism involving peroxisome proliferator-activated receptor-alpha (PPARalpha). High-fat feeding and hyperthyroidism, which increase circulating lipid supply, enhance hepatic PDK2 protein expression, but these increases are insufficient to account for observed increases in hepatic PDK activity. Enhanced expression of PDK4, but not PDK2, occurs in part via a mechanism involving PPAR-alpha. Heterodimerization partners for retinoid X receptors (RXRs) include PPARalpha and thyroid-hormone receptors (TRs). We therefore investigated the responses of hepatic PDK protein expression to high-fat feeding and hyperthyroidism in relation to hepatic lipid delivery and disposal. High-fat feeding increased hepatic PDK2, but not PDK4, protein expression whereas hyperthyroidism increased both hepatic PDK2 and PDK4 protein expression. Both manipulations decreased the sensitivity of hepatic carnitine palmitoyltransferase I (CPT I) to suppression by malonyl-CoA, but only hyperthyrodism elevated plasma fatty acid and ketone-body concentrations and CPT I maximal activity. Administration of the selective PPAR-alpha activator WY14,643 significantly increased PDK4 protein to a similar extent in both control and high-fat-fed rats, but WY14,643 treatment and hyperthyroidism did not have additive effects on hepatic PDK4 protein expression. PPARalpha activation did not influence hepatic PDK2 protein expression in euthyroid rats, suggesting that up-regulation of PDK2 by hyperthyroidism does not involve PPARalpha, but attenuated the effect of hyperthyroidism to increase hepatic PDK2 expression. The results indicate that hepatic PDK4 up-regulation can be achieved by heterodimerization of either PPARalpha or TR with the RXR receptor and that effects of PPARalpha activation on hepatic PDK2 and PDK4 expression favour a switch towards preferential expression of PDK4.

Transient co-expression of post-transcriptional gene silencing suppressors for increased in planta expression of a recombinant anthrax receptor fusion protein.

PubMed

Arzola, Lucas; Chen, Junxing; Rattanaporn, Kittipong; Maclean, James M; McDonald, Karen A

2011-01-01

Potential epidemics of infectious diseases and the constant threat of bioterrorism demand rapid, scalable, and cost-efficient manufacturing of therapeutic proteins. Molecular farming of tobacco plants provides an alternative for the recombinant production of therapeutics. We have developed a transient production platform that uses Agrobacterium infiltration of Nicotiana benthamiana plants to express a novel anthrax receptor decoy protein (immunoadhesin), CMG2-Fc. This chimeric fusion protein, designed to protect against the deadly anthrax toxins, is composed of the von Willebrand factor A (VWA) domain of human capillary morphogenesis 2 (CMG2), an effective anthrax toxin receptor, and the Fc region of human immunoglobulin G (IgG). We evaluated, in N. benthamiana intact plants and detached leaves, the expression of CMG2-Fc under the control of the constitutive CaMV 35S promoter, and the co-expression of CMG2-Fc with nine different viral suppressors of post-transcriptional gene silencing (PTGS): p1, p10, p19, p21, p24, p25, p38, 2b, and HCPro. Overall, transient CMG2-Fc expression was higher on intact plants than detached leaves. Maximum expression was observed with p1 co-expression at 3.5 days post-infiltration (DPI), with a level of 0.56 g CMG2-Fc per kg of leaf fresh weight and 1.5% of the total soluble protein, a ten-fold increase in expression when compared to absence of suppression. Co-expression with the p25 PTGS suppressor also significantly increased the CMG2-Fc expression level after just 3.5 DPI.

Gene expression information improves reliability of receptor status in breast cancer patients

PubMed Central

Kenn, Michael; Schlangen, Karin; Castillo-Tong, Dan Cacsire; Singer, Christian F.; Cibena, Michael; Koelbl, Heinz; Schreiner, Wolfgang

2017-01-01

Immunohistochemical (IHC) determination of receptor status in breast cancer patients is frequently inaccurate. Since it directs the choice of systemic therapy, it is essential to increase its reliability. We increase the validity of IHC receptor expression by additionally considering gene expression (GE) measurements. Crisp therapeutic decisions are based on IHC estimates, even if they are borderline reliable. We further improve decision quality by a responsibility function, defining a critical domain for gene expression. Refined normalization is devised to file any newly diagnosed patient into existing data bases. Our approach renders receptor estimates more reliable by identifying patients with questionable receptor status. The approach is also more efficient since the rate of conclusive samples is increased. We have curated and evaluated gene expression data, together with clinical information, from 2880 breast cancer patients. Combining IHC with gene expression information yields a method more reliable and also more efficient as compared to common practice up to now. Several types of possibly suboptimal treatment allocations, based on IHC receptor status alone, are enumerated. A ‘therapy allocation check’ identifies patients possibly miss-classified. Estrogen: false negative 8%, false positive 6%. Progesterone: false negative 14%, false positive 11%. HER2: false negative 2%, false positive 50%. Possible implications are discussed. We propose an ‘expression look-up-plot’, allowing for a significant potential to improve the quality of precision medicine. Methods are developed and exemplified here for breast cancer patients, but they may readily be transferred to diagnostic data relevant for therapeutic decisions in other fields of oncology. PMID:29100391

5HT2A receptor blockade in dorsomedial striatum reduces repetitive behaviors in BTBR mice.

PubMed

Amodeo, D A; Rivera, E; Cook, E H; Sweeney, J A; Ragozzino, M E

2017-03-01

Restricted and repetitive behaviors are a defining feature of autism, which can be expressed as a cognitive flexibility deficit or stereotyped, motor behaviors. There is limited knowledge about the underlying neuropathophysiology contributing to these behaviors. Previous findings suggest that central 5HT 2A receptor activity is altered in autism, while recent work indicates that systemic 5HT 2A receptor antagonist treatment reduces repetitive behaviors in an idiopathic model of autism. 5HT 2A receptors are expressed in the orbitofrontal cortex and striatum. These two regions have been shown to be altered in autism. The present study investigated whether 5HT 2A receptor blockade in the dorsomedial striatum or orbitofrontal cortex in the BTBR mouse strain, an idiopathic model of autism, affects the phenotype related to restricted and repetitive behaviors. Microinfusion of the 5HT 2A receptor antagonist, M100907 into the dorsomedial striatum alleviated a reversal learning impairment and attenuated grooming behavior. M100907 infusion into the orbitofrontal cortex increased perseveration during reversal learning and potentiated grooming. These findings suggest that increased 5HT 2A receptor activity in the dorsomedial striatum may contribute to behavioral inflexibility and stereotyped behaviors in the BTBR mouse. 5HT 2A receptor signaling in the orbitofrontal cortex may be critical for inhibiting a previously learned response during reversal learning and expression of stereotyped behavior. The present results suggest which brain areas exhibit abnormalities underlying repetitive behaviors in an idiopathic mouse model of autism, as well as which brain areas systemic treatment with M100907 may principally act on in BTBR mice to attenuate repetitive behaviors. © 2016 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

NOD2 Receptor is Expressed in Platelets and Enhances Platelet Activation and Thrombosis

PubMed Central

Zhang, Si; Zhang, Shenghui; Hu, Liang; Zhai, Lili; Xue, Ruyi; Ye, Jianqin; Chen, Leilei; Cheng, Guanjun; Mruk, Jozef; Kunapuli, Satya P.; Ding, Zhongren

2015-01-01

Background Pattern recognition receptor NOD2 (nucleotide binding oligomerization domain 2) is well investigated in immunity, its expression and function in platelets has never been explored. Method and Results Using RT-PCR and Western blot we show that both human and mouse platelets express NOD2, and its agonist MDP induced NOD2 activation as evidenced by receptor dimerization. NOD2 activation potentiates platelet aggregation and secretion induced by low concentration of thrombin or collagen, as well as clot retraction. These potentiating effects of MDP were not seen in platelets from NOD2-deficient mice. Plasma from septic patients also potentiates platelet aggregation induced by thrombin or collagen NOD2-dependently. Using intravital microscopy, we found that MDP administration accelerated in vivo thrombosis in FeCl3-injured mesenteric arteriole thrombosis mouse model. Platelet depletion and transfusion experiments confirmed that NOD2 from platelets contributes to the in vivo thrombosis in mice. NOD2 activation also accelerates platelet-dependent hemostasis. We further found that platelets express RIP2 (receptor-interacting protein 2), and provided evidences suggesting that MAPK and NO/sGC/cGMP/PGK pathways downstream of RIP2 mediate the role of NOD2 in platelets. Finally, MDP stimulates proinflammatory cytokine IL-1β maturation and accumulation in human and mouse platelets NOD2-dependently. Conclusions NOD2 is expressed in platelets and functions in platelet activation and arterial thrombosis, possibly during infection. To our knowledge, this is the first study on NOD-like receptors in platelets which links thrombotic events to inflammation. PMID:25825396

Cysteinyl leukotrienes C4 and D4 downregulate human mast cell expression of toll-like receptors 1 through 7.

PubMed

Karpov, V; Ilarraza, R; Catalli, A; Kulka, M

2018-01-01

Cysteinyl leukotrienes (CysLT) are potent inflammatory lipid molecules that mediate some of the pathophysiological responses associated with asthma such as bronchoconstriction, vasodilation and increased microvascular permeability. As a result, CysLT receptor antagonists (LRA), such as montelukast, have been used to effectively treat patients with asthma. We have recently shown that mast cells are necessary modulators of innate immune responses to bacterial infection and an important component of this innate immune response may involve the production of CysLT. However, the effect of LRA on innate immune receptors, particularly on allergic effector cells, is unknown. This study determined the effect of CysLT on toll-like receptor (TLR) expression by the human mast cell line LAD2. Real-time PCR analysis determined that LTC4, LTD4 and LTE4 downregulated mRNA expression of several TLR. Specifically in human CD34+-derived human mast cells (HuMC), LTC4 inhibited expression of TLR1, 2, 4, 5, 6 and 7 while LTD4 inhibited expression of TLR1-7. Montelukast blocked LTC4-mediated downregulation of all TLR, suggesting that these effects were mediated by activation of the CysLT1 receptor (CysLT1R). Flow cytometry analysis confirmed that LTC4 downregulated surface expression of TLR2 which was blocked by montelukast. These data show that CysLT can modulate human mast cell expression of TLR and that montelukast may be beneficial for innate immune responses mediated by mast cells.

Pattern of cytokine receptors expressed by human dendritic cells migrated from dermal explants.

PubMed Central

Larregina, A T; Morelli, A E; Kolkowski, E; Sanjuan, N; Barboza, M E; Fainboim, L

1997-01-01

Different reasons account for the lack of information about the expression of cytokine receptors on human dendritic cells (DC): (a) DC are a trace population; (b) the proteolytic treatment used to isolate DC may alter enzyme-sensitive epitopes; and (c) low numbers of receptors per cell. In the present work the expression of cytokine receptors was analysed by flow cytometry on the population of dermal DC (DDC) that spontaneously migrate from short-term culture dermal explants. DDC obtained after dermal culture were CD1alow, CD1b+, CD1c+, human leucocyte antigen (HLA)-DR+, CD11chigh, CD11b+ and CD32+. The DC lineage was confirmed by ultrastructural analysis. DDC expressed interleukin (IL)-1R type 1 (monoclonal antibody (mAb) hIL-1R1-M1; and 6B5); IL-1R type 2 (mAb hIL-1R2-M22); IL-2R alpha chain (mAb anti-Tac; and hIL-2R-M1) and IL-2R gamma chain (mAb 3B5; and AG14C). DDC did not stain for IL-2R beta chain using four mAbs recognizing two different epitopes of IL-2R beta (mAb 2R-B; Mik-beta 1; and CF1; Mik-beta 3, respectively). DDC were also positive for the cytokine binding chains (alpha chains) of IL-3R (mAb 9F5); IL-4R (mAb hIL-4R-M57; and S456C9); and IL-7R (mAb hIL-7R-M20; and R3434). DDC showed low levels of IL-6R alpha chain (mAb B-F19; B-R6; and B-E23) and its signal transducer gp130 (mAb A2; and B1). DDC strongly expressed interferon-gamma receptor (IFN-gamma R) (mAb GIR-208) and were negative for IL-8R (mAb B-G20; and B-F25). All DDC were highly positive for granulocyte-macrophage colony-stimulating factor receptor (GM-CSFR) alpha chain (mAb hGM-CSFR-M1; SC06; SC04, and 8G6) and to a lesser extent for the common beta chain of GM-CSFR, IL-3R and IL-5R (mAb 3D7). On the other hand, reactivity was not found for granulocyte colony-stimulating factor receptor (G-CSFR) (mAb hGCSFR-M1) nor macrophage colony-stimulating factor receptor (M-CSFR) (mAb 7-7A3-17) confirming the DC lineage of DDC. As previously reported for lymphoid DC, DDC expressed tumour necrosis factor receptort (TNFR) 75000 MW (mAb utr-1; hTNFR-M1; and MR2-1) but lacked TNFR 55000 MW (mAb htr-9; MR1-1; and MR1-2). In summary, DDC express receptors for a broad panel of cytokines, even receptors for cytokines whose effects on DC are still unknown (i.e. IL-2R alpha gamma; IL-6R alpha/gp 130; IL-7R alpha gamma). Images Figure 1 PMID:9227332

Sex steroid receptors and apoptosis-related proteins are differentially expressed in polycystic ovaries of adult dogs.

PubMed

Chuffa, Luiz Gustavo de Almeida; Lupi Júnior, Luiz Antonio; da Maia Lima, Alfredo Feio

2016-02-01

In Polycystic Ovaries (PCOs), the dynamics of sex hormone receptors and follicle-related apoptotic signaling remain unknown. In this study, we investigated the expression of androgen receptors (AR), estrogen receptors (ERα and ERβ), and apoptosis-related molecules (BAX, active caspase-3, Bcl-2 and Survivin) on different follicular stages of PCOs in adult dogs. Clinical evidences of high estradiol and testosterone levels, persistent estrus and vaginal discharge were observed. Inhibin B immunolabeling was increased in primary and 2 to 5-mm follicles, and a marked epithelial hyperplasia was common in the ovarian surface. Ovarian epithelia and primary follicles showed low expression of AR, ERα, and ERβ, whereas a moderate immunoexpression of AR was found in theca cells of secondary follicles and cysts. In PCOs, growing follicles displayed ERα expression, and secondary follicles exhibited higher ERβ expression. In addition, while few ERα-positive cells were found in the cysts, ERβ was moderately expressed in growing follicles and cysts. BAX was upregulated in the ovarian epithelium, primary follicles, and in the wall of follicular cysts. Active caspase-3 was significantly downregulated in the epithelium, primary follicles, and follicular cysts, whereas growing follicles had a strong immunoexpression in the granulosa cells. Bcl-2 and survivin were increased in the epithelium and primary follicles, and only survivin was upregulated in secondary and growing follicles. While Bcl-2 had a diffuse immunexpression in the follicular cysts, survivin was overexpressed by these cells. We concluded that sex steroid receptors and apoptotic proteins are differentially expressed in the follicles of adult dogs with PCOs. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bisphenol A Exposure Is Associated with in Vivo Estrogenic Gene Expression in Adults

PubMed Central

Melzer, David; Harries, Lorna; Cipelli, Riccardo; Henley, William; Money, Cathryn; McCormack, Paul; Young, Anita; Guralnik, Jack; Ferrucci, Luigi; Bandinelli, Stefania; Corsi, Anna Maria

2011-01-01

Background: Bisphenol A (BPA) is a synthetic estrogen commonly used in polycarbonate plastic and resin-lined food and beverage containers. Exposure of animal and cell models to doses of BPA below the recommended tolerable daily intake (TDI) of 50 μg/kg/day have been shown to alter specific estrogen-responsive gene expression, but this has not previously been shown in humans. Objective: We investigated associations between BPA exposure and in vivo estrogenic gene expression in humans. Methods: We studied 96 adult men from the InCHIANTI population study and examined in vivo expression of six estrogen receptor, estrogen-related receptor, and androgen receptor genes in peripheral blood leukocytes. Results: The geometric mean urinary BPA concentration was 3.65 ng/mL [95% confidence interval (CI): 3.13, 4.28], giving an estimated mean excretion of 5.84 μg/day (95% CI: 5.00, 6.85), significantly below the current TDI. In age-adjusted models, there were positive associations between higher BPA concentrations and higher ESR2 [estrogen receptor 2 (ER beta)] expression (unstandardized linear regression coefficient = 0.1804; 95% CI: 0.0388, 0.3221; p = 0.013) and ESRRA (estrogen related receptor alpha) expression (coefficient = 0.1718; 95% CI: 0.0213, 0.3223; p = 0.026): These associations were little changed after adjusting for potential confounders, including obesity, serum lipid concentrations, and white cell subtype percentages. Upper-tertile BPA excretors (urinary BPA > 4.6 ng/mL) had 65% higher mean ESR2 expression than did lower-tertile BPA excretors (0–2.4 ng/mL). Conclusions: Because activation of nuclear-receptor–mediated pathways by BPA is consistently found in laboratory studies, such activation in humans provides evidence that BPA is likely to function as a xenoestrogen in this sample of adults. PMID:21831745

K(Ca)3.1 channels facilitate K+ secretion or Na+ absorption depending on apical or basolateral P2Y receptor stimulation.

PubMed

Palmer, Melissa L; Peitzman, Elizabeth R; Maniak, Peter J; Sieck, Gary C; Prakash, Y S; O'Grady, Scott M

2011-07-15

Human mammary epithelial (HME) cells express several P2Y receptor subtypes located in both apical and basolateral membranes. Apical UTP or ATP-γ-S stimulation of monolayers mounted in Ussing chambers evoked a rapid, but transient decrease in short circuit current (I(sc)), consistent with activation of an apical K+ conductance. In contrast, basolateral P2Y receptor stimulation activated basolateral K+ channels and increased transepithelial Na+ absorption. Chelating intracellular Ca2+ using the membrane-permeable compound BAPTA-AM, abolished the effects of purinoceptor activation on I(sc). Apical pretreatment with charybdotoxin also blocked the I(sc) decrease by >90% and similar magnitudes of inhibition were observed with clotrimazole and TRAM-34. In contrast, iberiotoxin and apamin did not block the effects of apical P2Y receptor stimulation. Silencing the expression of K(Ca)3.1 produced ∼70% inhibition of mRNA expression and a similar reduction in the effects of apical purinoceptor agonists on I(sc). In addition, silencing P2Y2 receptors reduced the level of P2Y2 mRNA by 75% and blocked the effects of ATP-γ-S by 65%. These results suggest that P2Y2 receptors mediate the effects of purinoceptor agonists on K+ secretion by regulating the activity of K(Ca)3.1 channels expressed in the apical membrane of HME cells. The results also indicate that release of ATP or UTP across the apical or basolateral membrane elicits qualitatively different effects on ion transport that may ultimately determine the [Na+]/[K+] composition of fluid within the mammary ductal network.

STK-1, the human homolog of Flk-2/Flt-3, is selectively expressed in CD34+ human bone marrow cells and is involved in the proliferation of early progenitor/stem cells.

PubMed Central

Small, D; Levenstein, M; Kim, E; Carow, C; Amin, S; Rockwell, P; Witte, L; Burrow, C; Ratajczak, M Z; Gewirtz, A M

1994-01-01

We cloned the cDNA for stem cell tyrosine kinase 1 (STK-1), the human homolog of murine Flk-2/Flt-3, from a CD34+ hematopoietic stem cell-enriched library and investigated its expression in subsets of normal human bone marrow. The cDNA encodes a protein of 993 aa with 85% identity and 92% similarity to Flk-2/Flt-3. STK-1 is a member of the type III receptor tyrosine kinase family that includes KIT (steel factor receptor), FMS (colony-stimulating factor 1R), and platelet-derived growth factor receptor. STK-1 expression in human blood and marrow is restricted to CD34+ cells, a population greatly enriched for stem/progenitor cells. Anti-STK-1 antiserum recognizes polypeptides of 160 and 130 kDa in several STK-1-expressing cell lines and in 3T3 cells transfected with a STK-1 expression vector. Antisense oligonucleotides directed against STK-1 sequences inhibited hematopoietic colony formation, most strongly in long-term bone marrow cultures. These data suggest that STK-1 may function as a growth factor receptor on hematopoietic stem and/or progenitor cells. Images Fig. 2 Fig. 3 Fig. 4 PMID:7507245

The effect of clozapine on mRNA expression for genes encoding G protein-coupled receptors and the protein components of clathrin-mediated endocytosis

PubMed Central

Hu, Ying; Weymer, Jon F.; Rizig, Mie; McQuillin, Andrew; Hunt, Stephen P.; Gurling, Hugh M.D.

2013-01-01

Objectives Clathrin-mediated endocytosis (CME) is an intracellular trafficking mechanism for packaging cargo, including G protein-coupled receptors (GPCRs), into clathrin-coated vesicles (CCVs). The antipsychotic chlorpromazine inhibits CCV assembly of adaptor protein AP2 whereas clozapine increases serotonin2A receptor internalization. We hypothesized that clozapine alters the expression of CME genes modulating vesicle turnover and GPCR internalization. Materials and methods SH-SY5Y human neuroblastoma cells were incubated with clozapine (1–20 µmol/l) for 24–72 h. GPCR and CME-related gene mRNA expression was measured using RT-PCR. We quantified changes in the same genes using expression data from a microarray study of mice brains after 12 weeks of treatment with 12 mg/kg/day clozapine. Results The expression of genes encoding adaptor and clathrin assembly proteins, AP2A2, AP2B1, AP180, CLINT1, HIP1, ITSN2, and PICALM, increased relative to the control in SH-SY5Y cells incubated with 5–10 µmol/l clozapine for 24–72 h. The microarray study showed significantly altered expression of the above CME-related genes, with a marked 641-fold and 17-fold increase in AP180 and the serotonin1A GPCR, respectively. The expression of three serotonergic receptor and lysophosphatidic acid receptor 2 (EDG4) GPCR genes was upregulated in SH-SY5Y cells incubated with 5 µmol/l clozapine for 24 h. EDG4 expression was also increased with 10–20 µmol/l clozapine treatment at 48–72 h. Clozapine significantly decreased the expression of β-arrestin, involved in GPCR desensitization, both in vitro and vivo. Conclusion The changes we report in CME and GPCR mRNAs implicate CCV-mediated internalization of GPCRs and the serotonergic system in clozapine’s mechanism of action, which may be useful in the design of more effective and less toxic antipsychotic therapies. PMID:23811784

An essential role for IL-2 receptor in regulatory T cell function

PubMed Central

Levine, Andrew G; Fan, Xiying; Klein, Ulf; Zheng, Ye; Gasteiger, Georg; Feng, Yongqiang; Fontenot, Jason D.; Rudensky, Alexander Y.

2016-01-01

Regulatory T (Treg) cells, expressing abundant amounts of the IL-2 receptor (IL-2R), are reliant on IL-2 produced by activated T cells. This feature implied a key role for a simple network based on IL-2 consumption by Treg cells in their suppressor function. However, congenital deficiency in IL-2R results in reduced expression of the Treg cell lineage specification factor Foxp3, confounding experimental efforts to understand the role of IL-2R expression and signaling in Treg suppressor function. Using genetic gain and loss of function approaches, we demonstrate that IL-2 capture is dispensable for control of CD4+ T cells, but is important for limiting CD8+ T cell activation, and that IL-2R dependent STAT5 transcription factor activation plays an essential role in Treg cell suppressor function separable from T cell receptor signaling. PMID:27595233

Distribution and expression of non-neuronal transient receptor potential (TRPV) ion channels in rosacea.

PubMed

Sulk, Mathias; Seeliger, Stephan; Aubert, Jerome; Schwab, Verena D; Cevikbas, Ferda; Rivier, Michel; Nowak, Pawel; Voegel, Johannes J; Buddenkotte, Jörg; Steinhoff, Martin

2012-04-01

Rosacea is a frequent chronic inflammatory skin disease of unknown etiology. Because early rosacea reveals all characteristics of neurogenic inflammation, a central role of sensory nerves in its pathophysiology has been discussed. Neuroinflammatory mediators and their receptors involved in rosacea are poorly defined. Good candidates may be transient receptor potential (TRP) ion channels of vanilloid type (TRPV), which can be activated by many trigger factors of rosacea. Interestingly, TRPV2, TRPV3, and TRPV4 are expressed by both neuronal and non-neuronal cells. Here, we analyzed the expression and distribution of TRPV receptors in the various subtypes of rosacea on non-neuronal cells using immunohistochemistry, morphometry, double immunoflourescence, and quantitative real-time PCR (qRT-PCR) as compared with healthy skin and lupus erythematosus. Our results show that dermal immunolabeling of TRPV2 and TRPV3 and gene expression of TRPV1 is significantly increased in erythematotelangiectatic rosacea (ETR). Papulopustular rosacea (PPR) displayed an enhanced immunoreactivity for TRPV2, TRPV4, and also of TRPV2 gene expression. In phymatous rosacea (PhR)-affected skin, dermal immunostaining of TRPV3 and TRPV4 and gene expression of TRPV1 and TRPV3 was enhanced, whereas epidermal TRPV2 staining was decreased. Thus, dysregulation of TRPV channels also expressed by non-neuronal cells may be critically involved in the initiation and/or development of rosacea. TRP ion channels may be targets for the treatment of rosacea.

Distribution and Expression of Non-Neuronal Transient Receptor Potential (TRPV) Ion Channels in Rosacea

PubMed Central

Sulk, Mathias; Seeliger, Stephan; Aubert, Jerome; Schwab, Verena D.; Cevikbas, Ferda; Rivier, Michel; Nowak, Pawel; Voegel, Johannes J.; Buddenkotte, Jörg; Steinhoff, Martin

2011-01-01

Rosacea is a frequent chronic inflammatory skin disease of unknown etiology. Because early rosacea reveals all characteristics of neurogenic inflammation, a central role of sensory nerves in its pathophysiology has been discussed. Neuroinflammatory mediators and their receptors involved in rosacea are poorly defined. Good candidates may be transient receptor potential (TRP) ion channels of vanilloid type (TRPV), which can be activated by many trigger factors of rosacea. Interestingly, TRPV2, TRPV3, and TRPV4 are expressed by both neuronal and non-neuronal cells. Here, we analyzed the expression and distribution of TRPV receptors in the various subtypes of rosacea on non-neuronal cells using immunohistochemistry, morphometry, double immunoflourescence, and quantitative real-time PCR (qRT-PCR) as compared with healthy skin and lupus erythematosus. Our results show that dermal immunolabeling of TRPV2 and TRPV3 and gene expression of TRPV1 is significantly increased in erythematotelangiectatic rosacea (ETR). Papulopustular rosacea (PPR) displayed an enhanced immunoreactivity for TRPV2, TRPV4, and also of TRPV2 gene expression. In phymatous rosacea (PhR)-affected skin, dermal immunostaining of TRPV3 and TRPV4 and gene expression of TRPV1 and TRPV3 was enhanced, whereas epidermal TRPV2 staining was decreased. Thus, dysregulation of TRPV channels also expressed by non-neuronal cells may be critically involved in the initiation and/or development of rosacea. TRP ion channels may be targets for the treatment of rosacea. PMID:22189789

Differentiated human midbrain-derived neural progenitor cells express excitatory strychnine-sensitive glycine receptors containing α2β subunits.

PubMed

Wegner, Florian; Kraft, Robert; Busse, Kathy; Härtig, Wolfgang; Ahrens, Jörg; Leffler, Andreas; Dengler, Reinhard; Schwarz, Johannes

2012-01-01

Human fetal midbrain-derived neural progenitor cells (NPCs) may deliver a tissue source for drug screening and regenerative cell therapy to treat Parkinson's disease. While glutamate and GABA(A) receptors play an important role in neurogenesis, the involvement of glycine receptors during human neurogenesis and dopaminergic differentiation as well as their molecular and functional characteristics in NPCs are largely unknown. Here we investigated NPCs in respect to their glycine receptor function and subunit expression using electrophysiology, calcium imaging, immunocytochemistry, and quantitative real-time PCR. Whole-cell recordings demonstrate the ability of NPCs to express functional strychnine-sensitive glycine receptors after differentiation for 3 weeks in vitro. Pharmacological and molecular analyses indicate a predominance of glycine receptor heteromers containing α2β subunits. Intracellular calcium measurements of differentiated NPCs suggest that glycine evokes depolarisations mediated by strychnine-sensitive glycine receptors and not by D-serine-sensitive excitatory glycine receptors. Culturing NPCs with additional glycine, the glycine-receptor antagonist strychnine, or the Na(+)-K(+)-Cl(-) co-transporter 1 (NKCC1)-inhibitor bumetanide did not significantly influence cell proliferation and differentiation in vitro. These data indicate that NPCs derived from human fetal midbrain tissue acquire essential glycine receptor properties during neuronal maturation. However, glycine receptors seem to have a limited functional impact on neurogenesis and dopaminergic differentiation of NPCs in vitro.

Herpes B Virus Utilizes Human Nectin-1 but Not HVEM or PILRα for Cell-Cell Fusion and Virus Entry

PubMed Central

Fan, Qing; Amen, Melanie; Harden, Mallory; Severini, Alberto; Griffiths, Anthony

2012-01-01

To investigate the requirements of herpesvirus entry and fusion, the four homologous glycoproteins necessary for herpes simplex virus (HSV) fusion were cloned from herpes B virus (BV) (or macacine herpesvirus 1, previously known as cercopithecine herpesvirus 1) and cercopithecine herpesvirus 2 (CeHV-2), both related simian simplexviruses belonging to the alphaherpesvirus subfamily. Western blots and cell-based enzyme-linked immunosorbent assay (ELISA) showed that glycoproteins gB, gD, and gH/gL were expressed in whole-cell lysates and on the cell surface. Cell-cell fusion assays indicated that nectin-1, an HSV-1 gD receptor, mediated fusion of cells expressing glycoproteins from both BV and CeHV-2. However, herpesvirus entry mediator (HVEM), another HSV-1 gD receptor, did not facilitate BV- and CeHV-2-induced cell-cell fusion. Paired immunoglobulin-like type 2 receptor alpha (PILRα), an HSV-1 gB fusion receptor, did not mediate fusion of cells expressing glycoproteins from either simian virus. Productive infection with BV was possible only with nectin-1-expressing cells, indicating that nectin-1 mediated entry while HVEM and PILRα did not function as entry receptors. These results indicate that these alphaherpesviruses have differing preferences for entry receptors. The usage of the HSV-1 gD receptor nectin-1 may explain interspecies transfer of the viruses, and altered receptor usage may result in altered virulence, tropism, or pathogenesis in the new host. A heterotypic cell fusion assay resulting in productive fusion may provide insight into interactions that occur to trigger fusion. These findings may be of therapeutic significance for control of deadly BV infections. PMID:22345445