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Sample records for ii type-1 receptor

  1. Angiotensin II type 1 receptor antibodies in childhood kidney transplantation.

    PubMed

    Bjerre, Anna; Tangeraas, Trine; Heidecke, Harald; Dragun, Duska; Dechend, Ralf; Staff, Anne Cathrine

    2016-08-01

    Angiotensin II type 1 receptor antibodies (AT1 RAb) have emerged as non-HLA Ab present in patients with acute AMR and risk of graft loss. Furthermore, AT1 RAb have been shown to increase angiotensin II sensitivity which may play a role in the development of CVD and hypertension. Data on AT1 RAb in stable transplant recipients are lacking. The aim of this study was to analyze the levels of AT1 RAb in a cohort of stable patients after kidney transplantation (tx) in childhood. A cross-sectional study of 30 children (median age 14, range 3-19 yr, median time since tx five yr) and 28 adults who were transplanted in childhood (median age 26, range 20-40 yr, median time since tx 18 yr) transplanted between 1993-2006 and 1983-2002, respectively, was performed. Healthy controls were 51 healthy children (5-8 yr) and 199 healthy donors (median age 56.5 yr, range 42-83 yr). Plasma AT1 RAb were analyzed by immunoassay. Median total AT1 RAb IgG concentration was significantly higher in the pediatric-tx group as compared to the adult-tx group (40.0 and 10.95 U/mL, p < 0.0001). For both groups, the tx group showed higher levels: the pediatric-tx group vs. control group (40.0 vs. 13.3 U/mL, p = 0.0006) and the adult-tx group vs. adult control group (10.95 vs. 6.5 U/mL, p < 0.0001). Age was the strongest indicator of high levels of AT1 RAb IgG (p = 0.0003). AT1 RAb total IgG levels are significantly higher in a stable pediatric-tx cohort as compared to adult-tx patients and healthy controls of comparable age groups. The relevance of our findings in relation to age, time since tx, previous or future rejection, and CVD risk merits future studies. PMID:27251358

  2. The apelin receptor inhibits the angiotensin II type 1 receptor via allosteric trans-inhibition

    PubMed Central

    Siddiquee, K; Hampton, J; McAnally, D; May, LT; Smith, LH

    2013-01-01

    Background and Purpose The apelin receptor (APJ) is often co-expressed with the angiotensin II type-1 receptor (AT1) and acts as an endogenous counter-regulator. Apelin antagonizes Ang II signalling, but the precise molecular mechanism has not been elucidated. Understanding this interaction may lead to new therapies for the treatment of cardiovascular disease. Experimental Approach The physical interaction of APJ and AT1 receptors was detected by co-immunoprecipitation and bioluminescence resonance energy transfer (BRET). Functional and pharmacological interactions were measured by G-protein-dependent signalling and recruitment of β-arrestin. Allosterism and cooperativity between APJ and AT1 were measured by radioligand binding assays. Key Results Apelin, but not Ang II, induced APJ : AT1 heterodimerization forced AT1 into a low-affinity state, reducing Ang II binding. Likewise, apelin mediated a concentration-dependent depression in the maximal production of inositol phosphate (IP1) and β-arrestin recruitment to AT1 in response to Ang II. The signal depression approached a limit, the magnitude of which was governed by the cooperativity indicative of a negative allosteric interaction. Fitting the data to an operational model of allosterism revealed that apelin-mediated heterodimerization significantly reduces Ang II signalling efficacy. These effects were not observed in the absence of apelin. Conclusions and Implications Apelin-dependent heterodimerization between APJ and AT1 causes negative allosteric regulation of AT1 function. As AT1 is significant in the pathogenesis of cardiovascular disease, these findings suggest that impaired apelin and APJ function may be a common underlying aetiology. Linked Article This article is commented on by Goupil et al., pp. 1101–1103 of this issue. To view this commentary visit http://dx.doi.org/10.1111/bph.12040 PMID:22935142

  3. Distortion of maternal-fetal angiotensin II type 1 receptor allele transmission in pre-eclampsia.

    PubMed Central

    Morgan, L; Crawshaw, S; Baker, P N; Brookfield, J F; Broughton Pipkin, F; Kalsheker, N

    1998-01-01

    OBJECTIVE: To investigate the fetal angiotensin II type 1 receptor genotype in pre-eclampsia. DESIGN: Case-control study. POPULATION: Forty-one maternal-fetal pairs from pre-eclamptic pregnancies and 80 maternal-fetal pairs from normotensive pregnancies. METHODS: Maternal and fetal DNA was genotyped at three diallelic polymorphisms, at nucleotides 573, 1062, and 1166, in the coding exon of the angiotensin II type 1 receptor gene, and at a dinucleotide repeat polymorphism in its 3' flanking region. RESULTS: Allele and genotype frequencies at the four polymorphic regions investigated did not differ between pre-eclamptic and normotensive groups, in either fetal or maternal samples. Mothers heterozygous for the dinucleotide repeat allele designated A4 transmitted this allele to the fetus in 15 of 18 informative pre-eclamptic pregnancies and in eight of 26 normotensive pregnancies. This was greater than the expected probability in pre-eclamptic pregnancies (p=0.04) and less than expected in normotensive pregnancies (p<0.005). The 573T variant, which is in partial linkage disequilibrium with the A4 allele, showed a similar distortion of maternal-fetal transmission. CONCLUSION: Angiotensin II type 1 receptor gene expression in the fetus may contribute to the aetiology of pre-eclampsia. It is unclear whether susceptibility is conferred by the fetal genotype acting alone, or by allele sharing by mother and fetus. Possible mechanisms for the effect of the angiotensin II type 1 receptor gene are suggested by the association of the 573T variant with low levels of surface receptor expression on platelets. If receptor expression is similarly genetically determined in the placenta, responsiveness to angiotensin II may be affected, with the potential to influence placentation or placental prostaglandin secretion. PMID:9719367

  4. Structure-Function Basis of Attenuated Inverse Agonism of Angiotensin II Type 1 Receptor Blockers for Active-State Angiotensin II Type 1 Receptor.

    PubMed

    Takezako, Takanobu; Unal, Hamiyet; Karnik, Sadashiva S; Node, Koichi

    2015-09-01

    Ligand-independent signaling by the angiotensin II type 1 receptor (AT1R) can be activated in clinical settings by mechanical stretch and autoantibodies as well as receptor mutations. Transition of the AT1R to the activated state is known to lower inverse agonistic efficacy of clinically used AT1R blockers (ARBs). The structure-function basis for reduced efficacy of inverse agonists is a fundamental aspect that has been understudied not only in relation to the AT1R but also regarding other homologous receptors. Here, we demonstrate that the active-state transition in the AT1R indeed attenuates an inverse agonistic effect of four biphenyl-tetrazole ARBs through changes in specific ligand-receptor interactions. In the ground state, tight interactions of four ARBs with a set of residues (Ser109(TM3), Phe182(ECL2), Gln257(TM6), Tyr292(TM7), and Asn295(TM7)) results in potent inverse agonism. In the activated state, the ARB-AT1R interactions shift to a different set of residues (Val108(TM3), Ser109(TM3), Ala163(TM4), Phe182(ECL2), Lys199(TM5), Tyr292(TM7), and Asn295(TM7)), resulting in attenuated inverse agonism. Interestingly, V108I, A163T, N295A, and F182A mutations in the activated state of the AT1R shift the functional response to the ARB binding toward agonism, but in the ground state the same mutations cause inverse agonism. Our data show that the second extracellular loop is an important regulator of the functional states of the AT1R. Our findings suggest that the quest for discovering novel ARBs, and improving current ARBs, fundamentally depends on the knowledge of the unique sets of residues that mediate inverse agonistic potency in the two states of the AT1R. PMID:26121982

  5. Impact of angiotensin II type 1 receptor gene polymorphism on insulin resistance in polycystic ovary syndrome.

    PubMed

    El-Mesallamy, H; El-Refaie, T; El-Razek, R A

    2013-04-01

    Insulin resistance is allegedly a target pathophysiological mechanism in the pathogenesis of polycystic ovary syndrome. Moreover, this metabolic alteration is possibly genetically determined. In view of the recent evidence implicating genetic variants of the renin-angiotensin system as candidates in several metabolic disorders, we investigated the allele and genotype frequencies of the A1166 C polymorphism of the angiotensin II type 1 receptor in relation with various metabolic and biochemical parameters in affected females trying to asses its role in the pathogenesis of this syndrome. The study was conducted on 83 females of which 39 females served as the control group. The participants were matched for age, body mass index and degree of obesity. For all subjects biochemical parameters were assayed including soluble CD40 ligand together with fasting glucose and insulin which were used for calculation of insulin resistance indices, Genotyping performed using real time polymerase chain reaction revealed that the C allele frequency and the AC genotype were less frequently observed in patients compared to controls, however this difference was not statistically significant (p=0.146). Lack of the C allele was associated with adverse metabolic parameters including higher rate of insulin resistance as well as solubes CD40 ligand in the patients group. Results of the current study support a causative role for the A1166 C polymorphism of the angiotensin II type 1 gene polymorphism in the pathogenesis or phenotypic expression of polycystic ovary syndrome. PMID:23564192

  6. Angiotensin II type 1 receptor polymorphisms and susceptibility to hypertension: A HuGE review

    PubMed Central

    Mottl, Amy K.; Shoham, David A.; North, Kari E.

    2016-01-01

    The angiotensin II type 1 receptor (AGTR1) plays an integral role in blood pressure control, and is implicated in the pathogenesis of hypertension. Polymorphisms within this gene have been extensively studied in association with hypertension; however, findings are conflicting. To clarify these data, we conducted a systematic review of association studies of AGTR1 polymorphisms and hypertension, and performed a meta-analysis of the rs5186 variant. Results show that the currently available literature is too heterogeneous to draw meaningful conclusions. The definition of hypertension and gender composition of individual studies helps to explain this heterogeneity. Although the structure and splicing pattern of AGTR1 would suggest a likely effect of polymorphisms within the promoter region on gene function, few studies have been conducted thus far. In conclusion, there is insufficient evidence that polymorphisms in the AGTR1 gene are risk factors for hypertension. However, most studies are inadequately powered, and larger well-designed studies of haplotypes are warranted. PMID:18641512

  7. Angiotensin II type 1 receptor antagonists in animal models of vascular, cardiac, metabolic and renal disease.

    PubMed

    Michel, Martin C; Brunner, Hans R; Foster, Carolyn; Huo, Yong

    2016-08-01

    We have reviewed the effects of angiotensin II type 1 receptor antagonists (ARBs) in various animal models of hypertension, atherosclerosis, cardiac function, hypertrophy and fibrosis, glucose and lipid metabolism, and renal function and morphology. Those of azilsartan and telmisartan have been included comprehensively whereas those of other ARBs have been included systematically but without intention of completeness. ARBs as a class lower blood pressure in established hypertension and prevent hypertension development in all applicable animal models except those with a markedly suppressed renin-angiotensin system; blood pressure lowering even persists for a considerable time after discontinuation of treatment. This translates into a reduced mortality, particularly in models exhibiting marked hypertension. The retrieved data on vascular, cardiac and renal function and morphology as well as on glucose and lipid metabolism are discussed to address three main questions: 1. Can ARB effects on blood vessels, heart, kidney and metabolic function be explained by blood pressure lowering alone or are they additionally directly related to blockade of the renin-angiotensin system? 2. Are they shared by other inhibitors of the renin-angiotensin system, e.g. angiotensin converting enzyme inhibitors? 3. Are some effects specific for one or more compounds within the ARB class? Taken together these data profile ARBs as a drug class with unique properties that have beneficial effects far beyond those on blood pressure reduction and, in some cases distinct from those of angiotensin converting enzyme inhibitors. The clinical relevance of angiotensin receptor-independent effects of some ARBs remains to be determined. PMID:27130806

  8. Angiotensin II type 1 receptor blockers as a first choice in patients with acute myocardial infarction

    PubMed Central

    Lee, Jang Hoon; Bae, Myung Hwan; Yang, Dong Heon; Park, Hun Sik; Cho, Yongkeun; Lee, Won Kee; Jeong, Myung Ho; Kim, Young Jo; Cho, Myeong Chan; Kim, Chong Jin; Chae, Shung Chull

    2016-01-01

    Background/Aims: Angiotensin II type 1 receptor blockers (ARBs) have not been adequately evaluated in patients without left ventricular (LV) dysfunction or heart failure after acute myocardial infarction (AMI). Methods: Between November 2005 and January 2008, 6,781 patients who were not receiving angiotensin-converting enzyme inhibitors (ACEIs) or ARBs were selected from the Korean AMI Registry. The primary endpoints were 12-month major adverse cardiac events (MACEs) including death and recurrent AMI. Results: Seventy percent of the patients were Killip class 1 and had a LV ejection fraction ≥ 40%. The prescription rate of ARBs was 12.2%. For each patient, a propensity score, indicating the likelihood of using ARBs during hospitalization or at discharge, was calculated using a non-parsimonious multivariable logistic regression model, and was used to match the patients 1:4, yielding 715 ARB users versus 2,860 ACEI users. The effect of ARBs on in-hospital mortality and 12-month MACE occurrence was assessed using matched logistic and Cox regression models. Compared with ACEIs, ARBs significantly reduced in-hospital mortality(1.3% vs. 3.3%; hazard ratio [HR], 0.379; 95% confidence interval [CI], 0.190 to0.756; p = 0.006) and 12-month MACE occurrence (4.6% vs. 6.9%; HR, 0.661; 95% CI, 0.457 to 0.956; p = 0.028). However, the benefit of ARBs on 12-month mortality compared with ACEIs was marginal (4.3% vs. 6.2%; HR, 0.684; 95% CI, 0.467 to 1.002; p = 0.051). Conclusions: Our results suggest that ARBs are not inferior to, and may actually be better than ACEIs in Korean patients with AMI. PMID:26701233

  9. Vascular Type 1A Angiotensin II Receptors Control BP by Regulating Renal Blood Flow and Urinary Sodium Excretion.

    PubMed

    Sparks, Matthew A; Stegbauer, Johannes; Chen, Daian; Gomez, Jose A; Griffiths, Robert C; Azad, Hooman A; Herrera, Marcela; Gurley, Susan B; Coffman, Thomas M

    2015-12-01

    Inappropriate activation of the type 1A angiotensin (AT1A) receptor contributes to the pathogenesis of hypertension and its associated complications. To define the role for actions of vascular AT1A receptors in BP regulation and hypertension pathogenesis, we generated mice with cell-specific deletion of AT1A receptors in smooth muscle cells (SMKO mice) using Loxp technology and Cre transgenes with robust expression in both conductance and resistance arteries. We found that elimination of AT1A receptors from vascular smooth muscle cells (VSMCs) caused a modest (approximately 7 mmHg) yet significant reduction in baseline BP and exaggerated sodium sensitivity in mice. Additionally, the severity of angiotensin II (Ang II)-dependent hypertension was dramatically attenuated in SMKO mice, and this protection against hypertension was associated with enhanced urinary excretion of sodium. Despite the lower BP, acute vasoconstrictor responses to Ang II in the systemic vasculature were largely preserved (approximately 80% of control levels) in SMKO mice because of exaggerated activity of the sympathetic nervous system rather than residual actions of AT1B receptors. In contrast, Ang II-dependent responses in the renal circulation were almost completely eliminated in SMKO mice (approximately 5%-10% of control levels). These findings suggest that direct actions of AT1A receptors in VSMCs are essential for regulation of renal blood flow by Ang II and highlight the capacity of Ang II-dependent vascular responses in the kidney to effect natriuresis and BP control. PMID:25855778

  10. 12-Lipoxygenase Inhibition on Microalbuminuria in Type-1 and Type-2 Diabetes Is Associated with Changes of Glomerular Angiotensin II Type 1 Receptor Related to Insulin Resistance

    PubMed Central

    Xu, Hong-Zhao; Cheng, Yan-Li; Wang, Wan-Ning; Wu, Hao; Zhang, Yuan-Yuan; Zang, Chong-Sen; Xu, Zhong-Gao

    2016-01-01

    (1) Background: 12-lipoxygenase (12-LO) is involved in the development of diabetic nephropathy (DN). In the present study, we investigated whether 12-LO inhibition may ameliorate type-2 DN (T2DN) by interfering with insulin resistance (IR); (2) Methods: Rat glomerular mesangial cells, glomeruli and skeletal muscles were isolated and used in this study. Kidney histological changes were confirmed by periodic-acid Schiff staining; mRNA expression was detected by competitive reverse transcription polymerase chain reaction; and the protein level was determined by Western blot and the enzyme-linked immunosorbent assay, respectively; (3) Results: The inhibition of 12-LO attenuated microalbuminuria (MAU) increases in type-2 diabetic rats, but not in type-1 diabetic rats. Infusion of 12(S)-hydroxyeicosatetraenoic acid (12(S)-HETE) significantly increased the expression of angiotensin II (Ang II) and Ang II type 1 receptor (AT1R), but decreased the expression of AT1R-associated protein (ATRAP) in rat glomeruli, compared to the control. An in vitro study revealed that both 12(S)-HETE and insulin upregulated AT1R expression in rat mesangial cells. In the presence of p38 mitogen-activated protein kinase (MAPK) inhibitor, SB202190, the 12(S)-HETE-induced ATRAP reduction was significantly abolished. Interestingly, 12-LO inhibition did not influence AT1R expression in type-1 diabetic rats, but significantly abolished the increased AT1R and Ang II expression in glomeruli of type-2 diabetic rats. Furthermore, the inhibition of 12-LO significantly corrected impaired insulin sensitivity and fast serum insulin level, as well as the p-AMP-activated protein kinase (AMPK) reduction in skeletal muscle of type-2 diabetic rats; (4) Conclusion: The inhibition of 12-LO potentially ameliorated MAU by preventing IR through the downregulation of glomerular AT1R expression in T2DN. PMID:27164093

  11. The angiotensin II type 1 receptor blocker candesartan suppresses proliferation and fibrosis in gastric cancer.

    PubMed

    Okazaki, Mitsuyoshi; Fushida, Sachio; Harada, Shinichi; Tsukada, Tomoya; Kinoshita, Jun; Oyama, Katsunobu; Tajima, Hidehiro; Ninomiya, Itasu; Fujimura, Takashi; Ohta, Tetsuo

    2014-12-01

    Gastric cancer with peritoneal dissemination has poor clinical prognosis because of the presence of rich stromal fibrosis and acquired drug resistance. Recently, Angiotensin II type I receptor blockers such as candesartan have attracted attention for their potential anti-fibrotic activity. We examined whether candesartan could attenuate tumor proliferation and fibrosis through the interaction between gastric cancer cell line (MKN45) cells and human peritoneal mesothelial cells. Candesartan significantly reduced TGF-β1 expression and epithelial-to-mesenchymal transition-like change, while tumor proliferation and stromal fibrosis were impaired. Targeting the Angiotensin II signaling pathway may therefore be an efficient strategy for treatment of tumor proliferation and fibrosis. PMID:25224569

  12. Angiotensin II type 1 receptor blocker losartan prevents and rescues cerebrovascular, neuropathological and cognitive deficits in an Alzheimer's disease model.

    PubMed

    Ongali, Brice; Nicolakakis, Nektaria; Tong, Xin-Kang; Aboulkassim, Tahar; Papadopoulos, Panayiota; Rosa-Neto, Pedro; Lecrux, Clotilde; Imboden, Hans; Hamel, Edith

    2014-08-01

    Angiotensin II (AngII) receptor blockers that bind selectively AngII type 1 (AT1) receptors may protect from Alzheimer's disease (AD). We studied the ability of the AT1 receptor antagonist losartan to cure or prevent AD hallmarks in aged (~18months at endpoint, 3months treatment) or adult (~12months at endpoint, 10months treatment) human amyloid precursor protein (APP) transgenic mice. We tested learning and memory with the Morris water maze, and evaluated neurometabolic and neurovascular coupling using [(18)F]fluoro-2-deoxy-D-glucose-PET and laser Doppler flowmetry responses to whisker stimulation. Cerebrovascular reactivity was assessed with on-line videomicroscopy. We measured protein levels of oxidative stress enzymes (superoxide dismutases SOD1, SOD2 and NADPH oxidase subunit p67phox), and quantified soluble and deposited amyloid-β (Aβ) peptide, glial fibrillary acidic protein (GFAP), AngII receptors AT1 and AT2, angiotensin IV receptor AT4, and cortical cholinergic innervation. In aged APP mice, losartan did not improve learning but it consolidated memory acquisition and recall, and rescued neurovascular and neurometabolic coupling and cerebrovascular dilatory capacity. Losartan normalized cerebrovascular p67phox and SOD2 protein levels and up-regulated those of SOD1. Losartan attenuated astrogliosis, normalized AT1 and AT4 receptor levels, but failed to rescue the cholinergic deficit and the Aβ pathology. Given preventively, losartan protected cognitive function, cerebrovascular reactivity, and AT4 receptor levels. Like in aged APP mice, these benefits occurred without a decrease in soluble Aβ species or plaque load. We conclude that losartan exerts potent preventive and restorative effects on AD hallmarks, possibly by mitigating AT1-initiated oxidative stress and normalizing memory-related AT4 receptors. PMID:24807206

  13. Angiotensin II centrally induces frequent detrusor contractility of the bladder by acting on brain angiotensin II type 1 receptors in rats

    PubMed Central

    Kawamoto, Bunya; Shimizu, Shogo; Shimizu, Takahiro; Higashi, Youichirou; Honda, Masashi; Sejima, Takehiro; Saito, Motoaki; Takenaka, Atsushi

    2016-01-01

    Angiotensin (Ang) II plays an important role in the brain as a neurotransmitter and is involved in psychological stress reactions, for example through activation of the sympatho-adrenomedullary system. We investigated the effects of centrally administered Ang II on the micturition reflex, which is potentially affected by the sympatho-adrenomedullary system, and brain Ang II receptors in urethane-anesthetized (1.0 g/kg, intraperitoneally) male rats. Central administration of Ang II (0.01, 0.02, and 0.07 nmol per rat, intracerebroventricularly, icv) but not vehicle rapidly and dose-dependently decreased the urinary bladder intercontraction interval, without altering the bladder detrusor pressure. Central administration of antagonists of Ang II type 1 but not type 2 receptors inhibited the Ang II-induced shortening of intercontraction intervals. Administration of the highest dose of Ang II (0.07 nmol per rat, icv) but not lower doses (0.01 and 0.02 nmol per rat, icv) elevated the plasma concentration of adrenaline. Bilateral adrenalectomy reduced Ang II-induced elevation in adrenaline, but had no effect on the Ang II-induced shortening of the intercontraction interval. These data suggest that central administration of Ang II increases urinary frequency by acting on brain Ang II type 1 receptors, independent of activation of the sympatho-adrenomedullary system. PMID:26908391

  14. Troglitazone stimulates {beta}-arrestin-dependent cardiomyocyte contractility via the angiotensin II type 1{sub A} receptor

    SciTech Connect

    Tilley, Douglas G.; Nguyen, Anny D.; Rockman, Howard A.; Department of Cell Biology, Duke University Medical Center; Department of Molecular Genetics and Microbiology, Duke University Medical Center

    2010-06-11

    Peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) agonists are commonly used to treat cardiovascular diseases, and are reported to have several effects on cardiovascular function that may be due to PPAR{gamma}-independent signaling events. Select angiotensin receptor blockers (ARBs) interact with and modulate PPAR{gamma} activity, thus we hypothesized that a PPAR{gamma} agonist may exert physiologic effects via the angiotensin II type 1{sub A} receptor (AT1{sub A}R). In AT1{sub A}R-overexpressing HEK 293 cells, both angiotensin II (Ang II) and the PPAR{gamma} agonist troglitazone (Trog) enhanced AT1{sub A}R internalization and recruitment of endogenous {beta}-arrestin1/2 ({beta}arr1/2) to the AT1{sub A}R. A fluorescence assay to measure diacylglycerol (DAG) accumulation showed that although Ang II induced AT1{sub A}R-G{sub q} protein-mediated DAG accumulation, Trog had no impact on DAG generation. Trog-mediated recruitment of {beta}arr1/2 was selective to AT1{sub A}R as the response was prevented by an ARB- and Trog-mediated {beta}arr1/2 recruitment to {beta}1-adrenergic receptor ({beta}1AR) was not observed. In isolated mouse cardiomyocytes, Trog increased both % and rate of cell shortening to a similar extent as Ang II, effects which were blocked with an ARB. Additionally, these effects were found to be {beta}arr2-dependent, as cardiomyocytes isolated from {beta}arr2-KO mice showed blunted contractile responses to Trog. These findings show for the first time that the PPAR{gamma} agonist Trog acts at the AT1{sub A}R to simultaneously block G{sub q} protein activation and induce the recruitment of {beta}arr1/2, which leads to an increase in cardiomyocyte contractility.

  15. Preparation and Biological Activity of the Monoclonal Antibody against the Second Extracellular Loop of the Angiotensin II Type 1 Receptor

    PubMed Central

    Wei, Mingming; Zhao, Chengrui; Zhang, Suli; Wang, Li; Liu, Huirong; Ma, Xinliang

    2016-01-01

    The current study was to prepare a mouse-derived antibody against the angiotensin II type 1 receptor (AT1-mAb) based on monoclonal antibody technology, to provide a foundation for research on AT1-AA-positive diseases. Balb/C mice were actively immunized with the second extracellular loop of the angiotensin II type 1 receptor (AT1R-ECII). Then, mouse spleen lymphocytes were fused with myeloma cells and monoclonal hybridomas that secreted AT1-mAb were generated and cultured, after which those in logarithmic-phase were injected into the abdominal cavity of mice to retrieve the ascites. Highly purified AT1-mAb was isolated from mouse ascites after injection with 1 × 107 hybridomas. A greater amount of AT1-mAb was purified from mouse ascites compared to the cell supernatant of hybridomas. AT1-mAb purified from mouse ascites constricted the thoracic aorta of mice and increased the beat frequency of neonatal rat myocardial cells via the AT1R, identical to the effects of AT1-AA extracted from patients' sera. Murine blood pressure increased after intravenous injection of AT1-mAb via the tail vein. High purity and good biological activity of AT1-mAb can be obtained from mouse ascites after intraperitoneal injection of monoclonal hybridomas that secrete AT1-mAb. These data provide a simple tool for studying AT1-AA-positive diseases. PMID:27057554

  16. Hypercholesterolaemia exacerbates ventricular remodelling after myocardial infarction in the rat: role of angiotensin II type 1 receptors

    PubMed Central

    Mączewski, M; Mączewska, J; Duda, M

    2008-01-01

    Background and purpose: Diet-induced hypercholesterolaemia exacerbates post-myocardial infarction (MI) ventricular remodelling and heart failure, but the mechanism of this phenomenon remains unknown. This study examined whether worsening of post-MI ventricular remodelling induced by dietary hypercholesterolaemia was related to upregulation of angiotensin II type 1 (AT1) receptor in the rat heart. Experimental approach: MI was induced surgically in rats fed normal or high cholesterol diet. Both groups of rats were then assigned to control, atorvastatin, losartan or atorvastatin+losartan-treated subgroups and followed for 8 weeks. Left ventricular (LV) function was assessed with echocardiography. In isolated hearts, LV pressures were measured with a latex balloon and a tip catheter. AT1-receptor density was assessed in LV membranes with radioligand-binding assays. Key results: High cholesterol diet exacerbated LV dilation and dysfunction in post-MI hearts. Atorvastatin or losartan prevented these hypercholesterolaemia-induced effects, whereas their combination was not more effective than each drug alone. AT1 receptors were upregulated 8 weeks after MI, this was further increased by hypercholesterolaemia and restored to baseline levels by atorvastatin. Conclusions and implications: Hypercholesterolaemia exacerbated LV remodelling and dysfunction in post-MI rat hearts and upregulated cardiac AT1 receptors. All these effects were effectively prevented by atorvastatin. Thus, the pleiotropic statin effects may include interference with the renin-angiotensin system through downregulation of AT1 receptors. PMID:18536757

  17. A different role of angiotensin II type 1a receptor in the development and hypertrophy of plantaris muscle in mice.

    PubMed

    Zempo, Hirofumi; Suzuki, Jun-Ichi; Ogawa, Masahito; Watanabe, Ryo; Isobe, Mitsuaki

    2016-02-01

    The role of angiotensin II type 1 (AT1) receptors in muscle development and hypertrophy remains unclear. This study was designed to reveal the effects that a loss of AT1 receptors has on skeletal muscle development and hypertrophy in mice. Eight-week-old male AT1a receptor knockout (AT1a(-/-)) mice were used for this experiment. The plantaris muscle to body weight ratio, muscle fiber cross-sectional area, and number of muscle fibers of AT1a(-/-) mice was significantly greater than wild type (WT) mice in the non-intervention condition. Next, the functional overload (OL) model was used to induce plantaris muscle hypertrophy by surgically removing the two triceps muscles consisting of the calf, soleus, and gastrocnemius muscles in mice. After 14 days of OL intervention, the plantaris muscle weight, the amount of fiber, and the fiber area increased. However, the magnitude of the increment of plantaris weight was not different between the two strains. Agtr1a mRNA expression did not change after OL in WT muscle. Actually, the Agt mRNA expression level of WT-OL was lower than WT-Control (C) muscle. An atrophy-related gene, atrogin-1 mRNA expression levels of AT1a(-/-)-C, WT-OL, and AT1a(-/-)-OL muscle were lower than that of WT-C muscle. Our findings suggest that AT1 receptor contributes to plantaris muscle development via atrogin-1 in mice. PMID:26025227

  18. [Current topic of next generation of angiotensin II type 1 receptor blockers].

    PubMed

    Mogi, Masaki; Horiuchi, Masatsugu

    2012-09-01

    Angiotensin receptor blockers(ARBs) are used as the first-choice anti-hypertensives for prevention of multiple organ damage. Recently, the next-generation ARBs have been expected to have more preventive effect for cardiovascular diseases. For example, metabosartans which have a partial agonistic effect of peroxisome proliferator-activated receptor gamma induce an improvement of metabolism compared with ordinary ARBs. Moreover, LCZ696, ARB with a neprilysin inhibitor which increases natriuretic peptides has a significant reduction in blood pressure compared with ARB. Furthermore, ARBs with nitric oxide donor or endothelin receptor blocker have been reported to have a benefit beyond ordinary ARBs. Dual action in the next multi-functional ARBs may be a strong therapeutic contributor for patients with multiple organ dysfunction. PMID:23012813

  19. Competing Actions of Type 1 Angiotensin II Receptors Expressed on T Lymphocytes and Kidney Epithelium during Cisplatin-Induced AKI.

    PubMed

    Zhang, Jiandong; Rudemiller, Nathan P; Patel, Mehul B; Wei, QingQing; Karlovich, Norah S; Jeffs, Alexander D; Wu, Min; Sparks, Matthew A; Privratsky, Jamie R; Herrera, Marcela; Gurley, Susan B; Nedospasov, Sergei A; Crowley, Steven D

    2016-08-01

    Inappropriate activation of the renin-angiotensin system (RAS) contributes to many CKDs. However, the role of the RAS in modulating AKI requires elucidation, particularly because stimulating type 1 angiotensin II (AT1) receptors in the kidney or circulating inflammatory cells can have opposing effects on the generation of inflammatory mediators that underpin the pathogenesis of AKI. For example, TNF-α is a fundamental driver of cisplatin nephrotoxicity, and generation of TNF-α is suppressed or enhanced by AT1 receptor signaling in T lymphocytes or the distal nephron, respectively. In this study, cell tracking experiments with CD4-Cre mT/mG reporter mice revealed robust infiltration of T lymphocytes into the kidney after cisplatin injection. Notably, knockout of AT1 receptors on T lymphocytes exacerbated the severity of cisplatin-induced AKI and enhanced the cisplatin-induced increase in TNF-α levels locally within the kidney and in the systemic circulation. In contrast, knockout of AT1 receptors on kidney epithelial cells ameliorated the severity of AKI and suppressed local and systemic TNF-α production induced by cisplatin. Finally, disrupting TNF-α production specifically within the renal tubular epithelium attenuated the AKI and the increase in circulating TNF-α levels induced by cisplatin. These results illustrate discrepant tissue-specific effects of RAS stimulation on cisplatin nephrotoxicity and raise the concern that inflammatory mediators produced by renal parenchymal cells may influence the function of remote organs by altering systemic cytokine levels. Our findings suggest selective inhibition of AT1 receptors within the nephron as a promising intervention for protecting patients from cisplatin-induced nephrotoxicity. PMID:26744488

  20. Brain Angiotensin II Type 1 Receptor Blockade Improves Dairy Blood Pressure Variability via Sympathoinhibition in Hypertensive Rats

    PubMed Central

    2015-01-01

    Abnormal blood pressure (BP) elevation in early morning is known to cause cardiovascular events. Previous studies have suggested that one of the reasons in abnormal dairy BP variability is sympathoexcitation. We have demonstrated that brain angiotensin II type 1 receptor (AT1R) causes sympathoexcitation. The aim of the present study was to investigate whether central AT1R blockade attenuates the excess BP elevation in rest-to-active phase in hypertensive rats or not. Stroke-prone spontaneously hypertensive rats (SHRSP) were treated with intracerebroventricular infusion (ICV) of AT1R receptor blocker (ARB), oral administration of hydralazine (HYD), or ICV of vehicle (VEH). Telemetric averaged mean BP (MBP) was measured at early morning (EM), after morning (AM), and night (NT). At EM, MBP was significantly lower in ARB to a greater extent than in HYD compared to VEH, though MBP at AM was the same in ARB and HYD. At NT, MBP was also significantly lower in ARB than in HYD. These results in MBP were compatible to those in sympathoexcitation and suggest that central AT1R blockade attenuates excess BP elevation in early active phase and continuous BP elevation during rest phase independent of depressor response in hypertensive rats. PMID:25918643

  1. Angiotensin II type-1 receptor blockers enhance the effects of bevacizumab-based chemotherapy in metastatic colorectal cancer patients

    PubMed Central

    OSUMI, HIROKI; MATSUSAKA, SATOSHI; WAKATSUKI, TAKERU; SUENAGA, MITSUKUNI; SHINOZAKI, EIIJ; MIZUNUMA, NOBUYUKI

    2015-01-01

    The local renin-angiotensin system promotes angiogenesis and vascular proliferation via expression of vascular endothelial growth factor or epidermal growth factor receptor. We hypothesized that angiotensin II type-1 receptor blockers (ARBs) in combination with bevacizumab (Bev) may improve clinical outcomes in patients with metastatic colorectal cancer (mCRC). A total of 181 patients with histopathologically confirmed mCRC treated with first-line oxaliplatin-based chemotherapy in combination with Bev were enrolled between June, 2007 and September, 2010. The patients were divided into two groups based on the presence or absence of treatment with ARBs prior to the initiation of second-line chemotherapy. Kaplan-Meier analysis and Cox proportional hazard modeling were used in the statistical analysis. The median progression-free survival (PFS) in patients undergoing second-line chemotherapy in combination with Bev and ARBs (n=56) vs. those treated in the absence of ARBs (n=33) was 8.3 vs. 5.7 months, respectively [hazard ratio (HR)=0.57, 95% confidence interval (CI): 0.35–0.94, P=0.028]. The median overall survival (OS) was 26.5 vs. 15.2 months, respectively (HR=0.47, 95% CI: 0.25–0.88, P=0.019). In the multivariate analysis, the use of ARBs was independently associated with prolongation of OS and PFS. In conclusion, the use of ARBs prolonged survival in mCRC patients. PMID:26807236

  2. Angiopoietin-like protein 2 expression is suppressed by angiotensin II via the angiotensin II type 1 receptor in rat cardiomyocytes

    PubMed Central

    Wang, Shuya; Li, Ying; Miao, Wei; Zhao, Hong; Zhang, Feng; Liu, Nan; Su, Guohai; Cai, Xiaojun

    2016-01-01

    The present study aimed to determine the inhibitory effects of angiotensin II (AngII) on angiopoietin-like protein 2 (Angptl2) in rat primary cardiomyocytes, and to investigate the potential association between angiotensin II type 1 receptor (AT1R) and these effects. Cardiomyocytes were isolated from 3-day-old Wistar rats, and were cultured and identified. Subsequently, the expression levels of Angptl2 were detected following incubation with various concentrations of AngII for various durations using western blotting, reverse transcription-quantitative polymerase chain reaction, enzyme-linked immunosorbent assay and immunofluorescence. Finally, under the most appropriate conditions (100 nmol/l AngII, 24 h), the cardiomyocytes were divided into six groups: Normal, AngII, AngII + losartan, normal + losartan, AngII + PD123319 and normal + PD123319 groups, in order to investigate the possible function of AT1R in Angptl2 suppression. Losartan and PD123319 are antagonists of AT1R and angiotensin II type 2 receptor, respectively. The statistical significance of the results was analyzed using Student's t-test or one-way analysis of variance. The results demonstrated that Angptl2 expression was evidently suppressed (P<0.05) following incubation with 100 nmol/l AngII for 24 h. Conversely, the expression levels of Angptl2 were significantly increased in the AngII + losartan group compared with the AngII group (P<0.01). However, no significant difference was detected between the AngII + PD123319, normal + losartan or normal + PD123319 groups and the normal group. The present in vitro study indicated that AngII was able to suppress Angptl2 expression, whereas losartan was able to significantly reverse this decrease by inhibiting AT1R. PMID:27483989

  3. Angiotensin II type 1 receptor A1166C gene polymorphism and essential hypertension in Calabar and Uyo cities, Nigeria

    PubMed Central

    Kooffreh, Mary Esien; Anumudu, Chiaka Ijeoma; Duke, Roseline; Okpako, Elza Cletus; Kumar, P. Lava

    2013-01-01

    OBJECTIVES: The angiotensin II protein is a vasoconstrictor that exerts most of its influence through the angiotensin II type 1 receptor (AT1R). Inconsistent association between the A1166C polymorphism of the AT1R gene and hypertension has been reported among various populations but not among the peoples of Calabar and Uyo. This study was designed to determine the frequency of the A1166C polymorphism of the AT1R gene and its association with hypertension in a sample population of Calabar and Uyo. MATERIALS AND METHODS: A population-based case control design consisting of total of 1224 participants, 612 each of patients and controls were randomly recruited from hypertension clinics and the general population. Genotyping of the A1166C allele of the AT1R gene to identify variants was performed using polymerase chain reaction and restriction enzyme digestion. Multiple regressions were applied to test whether the A1166 genotypes were predictors of hypertension. RESULTS: 99% of the study population had the wild type AA genotype, and 1% was AC heterozygous carriers of the A1166C polymorphism. CONCLUSION: The A1166C polymorphism was not a predictor of hypertension in the sample population of Calabar and Uyo. PMID:24019625

  4. The Prognostic Role of Angiotensin II Type 1 Receptor Autoantibody in Non-Gravid Hypertension and Pre-eclampsia

    PubMed Central

    Lei, Jinghui; Li, Yafeng; Zhang, Suli; Wu, Ye; Wang, Pengli; Liu, Huirong

    2016-01-01

    Abstract Angiotensin II type 1 receptor autoantibody (AT1-AA) is found in patients with non-gravid hypertension or pre-eclampsia, but the relationship is uncertain. The aim of the present study was to assess the association between AT1-AA and high blood pressure using meta-analysis, and to evaluate the prognosis value of AT1-AA for hypertensive diseases. Literature search from PubMed, Embase, and Cochrane databases were conducted using keywords “hypertension” or “pre-eclampsia,” “angiotensin II receptor type 1 autoantibody,” and its aliases from April 1999 to December 2015. Studies evaluating the association between AT1-AA and non-gravid hypertension or pre-eclampsia were included in this analysis. The quality of the eligible studies was assessed based on the Newcastle–Ottawa Scale with some modifications. Two researchers then independently reviewed all included studies and extracted all relevant data. Association between AT1-AA and hypertension was tested with pooled odds ratios (ORs) and 95% confidence intervals (CIs). Finally, we evaluated whether AT1-AA predicted the prognosis of hypertension by using a summary receiver-operating characteristic (ROC) curve and sensitivity analysis. Ten studies were finally included in this meta-analysis. AT1-AA showed more significant association with pre-eclampsia than that with non-gravid hypertension (pooled OR 32.84, 95% CI 17.19–62.74; and pooled OR 4.18, 95% CI 2.20–7.98, respectively). Heterogeneity among studies was also detected probably due to different hypertensive subtypes and AT1-AA measuring methods. Area under summary ROC curve (AUC) of pre-eclampsia was 0.92 (sensitivity 0.76; specificity 0.86). Area under the ROC curve of overall hypertensive diseases or non-gravid hypertension was lower than that of pre-eclampsia (0.86 and 0.72, respectively) with lower sensitivities (0.46 and 0.26, respectively). The major limitation of this analysis was the publication bias due to lack of unpublished data

  5. Impaired endocytosis in proximal tubule from subchronic exposure to cadmium involves angiotensin II type 1 and cubilin receptors

    PubMed Central

    2013-01-01

    Background Chronic exposure to low cadmium (Cd) levels produces urinary excretion of low molecular weight proteins, which is considered the critical effect of Cd exposure. However, the mechanisms involved in Cd-induced proteinuria are not entirely clear. Therefore, the present study was designed to evaluate the possible role of megalin and cubilin (important endocytic receptors in proximal tubule cells) and angiotensin II type 1 (AT1) receptor on Cd-induced microalbuminuria. Methods Four groups of female Wistar rats were studied. Control (CT) group, vehicle-treated rats; LOS group, rats treated with losartan (an AT1 antagonist) from weeks 5 to 8 (10 mg/kg/day by gavage); Cd group, rats subchronically exposed to Cd (3 mg/kg/day by gavage) during 8 weeks, and Cd + LOS group, rats treated with Cd for 8 weeks and LOS from weeks 5–8. Kidney Cd content, glomerular function (evaluated by creatinine clearance and plasma creatinine), kidney injury and tubular function (evaluated by Kim-1 expression, urinary excretion of N-acetyl-β-D-glucosaminidase (NAG) and glucose, and microalbuminuria), oxidative stress (measured by lipid peroxidation and NAD(P)H oxidase activity), mRNA levels of megalin, expressions of megalin and cubilin (by confocal microscopy) and AT1 receptor (by Western blot), were measured in the different experimental groups. Data were analyzed by one-way ANOVA or Kruskal-Wallis test using GraphPad Prism 5 software (Version 5.00). P < 0.05 was considered statistically significant. Results Administration of Cd (Cd and Cd + LOS groups) increased renal Cd content. LOS-treatment decreased Cd-induced microalbuminuria without changes in: plasma creatinine, creatinine clearance, urinary NAG and glucose, oxidative stress, mRNA levels of megalin and cubilin, neither protein expression of megalin nor AT1 receptor, in the different experimental groups studied. However, Cd exposure did induce the expression of the tubular injury marker Kim-1 and decreased

  6. Therapeutic Effect of Losartan, an Angiotensin II Type 1 Receptor Antagonist, on CCl4-Induced Skeletal Muscle Injury

    PubMed Central

    Hwang, Ok-Kyung; Park, Jin-Kyu; Lee, Eun-Joo; Lee, Eun-Mi; Kim, Ah-Young; Jeong, Kyu-Shik

    2016-01-01

    TGF-β1 is known to inhibit muscle regeneration after muscle injury. However, it is unknown if high systemic levels of TGF-β can affect the muscle regeneration process. In the present study, we demonstrated the effect of a CCl4 intra-peritoneal injection and losartan (an angiotensin II type 1 receptor antagonist) on skeletal muscle (gastrocnemius muscle) injury and regeneration. Male C57BL/6 mice were grouped randomly as follows: control (n = 7), CCl4-treatment group (n = 7), and CCl4 + losartan treatment group (n = 7). After CCl4 treatment for a 16-week period, the animals were sacrificed and analyzed. The expression of dystrophin significantly decreased in the muscle tissues of the control group, as compared with that of the CCl4 + losartan group (p < 0.01). p(phospho)-Smad2/3 expression significantly increased in the muscles of the control group compared to that in the CCl4 + losartan group (p < 0.01). The expressions of Pax7, MyoD, and myogenin increased in skeletal muscles of the CCl4 + losartan group compared to the corresponding levels in the control group (p < 0.01). We hypothesize that systemically elevated TGF-β1 as a result of CCl4-induced liver injury causes skeletal muscle injury, while losartan promotes muscle repair from injury via blockade of TGF-β1 signaling. PMID:26867195

  7. High-salt intake induces cardiomyocyte hypertrophy in rats in response to local angiotensin II type 1 receptor activation.

    PubMed

    Katayama, Isis A; Pereira, Rafael C; Dopona, Ellen P B; Shimizu, Maria H M; Furukawa, Luzia N S; Oliveira, Ivone B; Heimann, Joel C

    2014-10-01

    Many studies have shown that risk factors that are independent of blood pressure (BP) can contribute to the development of cardiac hypertrophy (CH). Among these factors, high-salt (HS) intake was prominent. Although some studies have attempted to elucidate the role of salt in the development of this disease, the mechanisms by which salt acts are not yet fully understood. Thus, the aim of this study was to better understand the mechanisms of CH and interstitial fibrosis (IF) caused by HS intake. Male Wistar rats were divided into 5 groups according to diet [normal salt (NS; 1.27% NaCl) or HS (8% NaCl)] and treatment [losartan (LOS) (HS+LOS group), hydralazine (HZ) (HS+HZ group), or N-acetylcysteine (NAC) (HS+NAC group)], which was given in the drinking water. Tail-cuff BP, transverse diameter of the cardiomyocyte, IF, angiotensin II type 1 receptor (AT1) gene and protein expression, serum aldosterone, cardiac angiotensin II, cardiac thiobarbituric acid-reactive substances, and binding of conformation-specific anti-AT1 and anti-angiotensin II type 2 receptor (AT2) antibodies in the 2 ventricles were measured. Based on the left ventricle transverse diameter data, the primary finding was the occurrence of significant BP-independent CH in the HS+HZ group (96% of the HS group) and a partial or total prevention of such hypertrophy via treatment with NAC or LOS (81% and 67% of the HS group, respectively). The significant total or partial prevention of IF using all 3 treatments (HS+HZ, 27%; HS+LOS, 27%; and HS+NAC, 58% of the HS group, respectively), and an increase in the AT1 gene and protein expression and activity in groups that developed CH, confirmed that CH occurred via the AT1 in this experimental model. Thus, this study unveiled some relevant previously unknown mechanisms of CH induced by chronic HS intake in Wistar rats. The link of oxidative stress with CH in our experimental model is very interesting and stimulates further evaluation for its full comprehension

  8. Mineralocorticoid and angiotensin II type 1 receptors in the subfornical organ mediate angiotensin II - induced hypothalamic reactive oxygen species and hypertension.

    PubMed

    Wang, Hong-Wei; Huang, Bing S; White, Roselyn A; Chen, Aidong; Ahmad, Monir; Leenen, Frans H H

    2016-08-01

    Activation of angiotensinergic pathways by central aldosterone (Aldo)-mineralocorticoid receptor (MR) pathway plays a critical role in angiotensin II (Ang II)-induced hypertension. The subfornical organ (SFO) contains both MR and angiotensin II type 1 receptors (AT1R) and can relay the signals of circulating Ang II to downstream nuclei such as the paraventricular nucleus (PVN), supraoptic nucleus (SON) and rostral ventrolateral medulla (RVLM). In Wistar rats, subcutaneous (sc) infusion of Ang II at 500ng/min/kg for 1 or 2weeks increased reactive oxygen species (ROS) as measured by dihydroethidium (DHE) staining in a nucleus - specific pattern. Intra-SFO infusion of AAV-MR- or AT1aR-siRNA prevented the Ang II-induced increase in AT1R mRNA expression in the SFO and decreased MR mRNA. Both MR- and AT1aR-siRNA prevented increases in ROS in the PVN and RVLM. MR- but not AT1aR-siRNA in the SFO prevented the Ang II-induced ROS in the SON. Both MR- and AT1aR-siRNA in the SFO prevented most of the Ang II-induced hypertension as assessed by telemetry. These results indicate that Aldo-MR signaling in the SFO is needed for the activation of Ang II-AT1R-ROS signaling from the SFO to the PVN and RVLM. Activation of Aldo-MR signaling from the SFO to the SON may enhance AT1R dependent activation of pre-sympathetic neurons in the PVN. PMID:27163380

  9. Functional Interaction between Angiotensin II Receptor Type 1 and Chemokine (C-C Motif) Receptor 2 with Implications for Chronic Kidney Disease

    PubMed Central

    Kelly, Robyn S.; See, Heng B.; Johnstone, Elizabeth K. M.; McCall, Elizabeth A.; Williams, James H.; Kelly, Darren J.; Pfleger, Kevin D. G.

    2015-01-01

    Understanding functional interactions between G protein-coupled receptors is of great physiological and pathophysiological importance. Heteromerization provides one important potential mechanism for such interaction between different signalling pathways via macromolecular complex formation. Previous studies suggested a functional interplay between angiotensin II receptor type 1 (AT1) and Chemokine (C-C motif) Receptor 2 (CCR2). However the molecular mechanisms are not understood. We investigated AT1-CCR2 functional interaction in vitro using bioluminescence resonance energy transfer in HEK293 cells and in vivo using subtotal-nephrectomized rats as a well-established model for chronic kidney disease. Our data revealed functional heteromers of these receptors resulting in CCR2-Gαi1 coupling being sensitive to AT1 activation, as well as apparent enhanced β-arrestin2 recruitment with agonist co-stimulation that is synergistically reversed by combined antagonist treatment. Moreover, we present in vivo findings where combined treatment with AT1- and CCR2-selective inhibitors was synergistically beneficial in terms of decreasing proteinuria, reducing podocyte loss and preventing renal injury independent of blood pressure in the subtotal-nephrectomized rat model. Our findings further support a role for G protein-coupled receptor functional heteromerization in pathophysiology and provide insights into previous observations indicating the importance of AT1-CCR2 functional interaction in inflammation, renal and hypertensive disorders. PMID:25807547

  10. Oxidized LDL (oxLDL) activates the angiotensin II type 1 receptor by binding to the lectin-like oxLDL receptor.

    PubMed

    Yamamoto, Koichi; Kakino, Akemi; Takeshita, Hikari; Hayashi, Norihiro; Li, Lei; Nakano, Atsushi; Hanasaki-Yamamoto, Hiroko; Fujita, Yoshiko; Imaizumi, Yuki; Toyama-Yokoyama, Serina; Nakama, Chikako; Kawai, Tatsuo; Takeda, Masao; Hongyo, Kazuhiro; Oguro, Ryosuke; Maekawa, Yoshihiro; Itoh, Norihisa; Takami, Yoichi; Onishi, Miyuki; Takeya, Yasushi; Sugimoto, Ken; Kamide, Kei; Nakagami, Hironori; Ohishi, Mitsuru; Kurtz, Theodore W; Sawamura, Tatsuya; Rakugi, Hiromi

    2015-08-01

    The angiotensin II type 1 receptor (AT1) is a 7-transmembrane domain GPCR that when activated by its ligand angiotensin II, generates signaling events promoting vascular dysfunction and the development of cardiovascular disease. Here, we show that the single-transmembrane oxidized LDL (oxLDL) receptor (LOX-1) resides in proximity to AT1 on cell-surface membranes and that binding of oxLDL to LOX-1 can allosterically activate AT1-dependent signaling events. oxLDL-induced signaling events in human vascular endothelial cells were abolished by knockdown of AT1 and inhibited by AT1 blockade (ARB). oxLDL increased cytosolic G protein by 350% in Chinese hamster ovary (CHO) cells with genetically induced expression of AT1 and LOX-1, whereas little increase was observed in CHO cells expressing only LOX-1. Immunoprecipitation and in situ proximity ligation assay (PLA) assays in CHO cells revealed the presence of cell-surface complexes involving LOX-1 and AT1. Chimeric analysis showed that oxLDL-induced AT1 signaling events are mediated via interactions between the intracellular domain of LOX-1 and AT1 that activate AT1. oxLDL-induced impairment of endothelium-dependent vascular relaxation of vascular ring from mouse thoracic aorta was abolished by ARB or genetic deletion of AT1. These findings reveal a novel pathway for AT1 activation and suggest a new mechanism whereby oxLDL may be promoting risk for cardiovascular disease. PMID:25877213

  11. Proximal tubule NHE3 activity is inhibited by beta-arrestin-biased angiotensin II type 1 receptor signaling.

    PubMed

    Carneiro de Morais, Carla P; Polidoro, Juliano Z; Ralph, Donna L; Pessoa, Thaissa D; Oliveira-Souza, Maria; Barauna, Valério G; Rebouças, Nancy A; Malnic, Gerhard; McDonough, Alicia A; Girardi, Adriana C C

    2015-10-15

    Physiological concentrations of angiotensin II (ANG II) upregulate the activity of Na(+)/H(+) exchanger isoform 3 (NHE3) in the renal proximal tubule through activation of the ANG II type I (AT1) receptor/G protein-coupled signaling. This effect is key for maintenance of extracellular fluid volume homeostasis and blood pressure. Recent findings have shown that selective activation of the beta-arrestin-biased AT1 receptor signaling pathway induces diuresis and natriuresis independent of G protein-mediated signaling. This study tested the hypothesis that activation of this AT1 receptor/beta-arrestin signaling inhibits NHE3 activity in proximal tubule. To this end, we determined the effects of the compound TRV120023, which binds to the AT1R, blocks G-protein coupling, and stimulates beta-arrestin signaling on NHE3 function in vivo and in vitro. NHE3 activity was measured in both native proximal tubules, by stationary microperfusion, and in opossum proximal tubule (OKP) cells, by Na(+)-dependent intracellular pH recovery. We found that 10(-7) M TRV120023 remarkably inhibited proximal tubule NHE3 activity both in vivo and in vitro. Additionally, stimulation of NHE3 by ANG II was completely suppressed by TRV120023 both in vivo as well as in vitro. Inhibition of NHE3 activity by TRV120023 was associated with a decrease in NHE3 surface expression in OKP cells and with a redistribution from the body to the base of the microvilli in the rat proximal tubule. These findings indicate that biased signaling of the beta-arrestin pathway through the AT1 receptor inhibits NHE3 activity in the proximal tubule at least in part due to changes in NHE3 subcellular localization. PMID:26246427

  12. Lipid rafts are required for signal transduction by angiotensin II receptor type 1 in neonatal glomerular mesangial cells

    SciTech Connect

    Adebiyi, Adebowale Soni, Hitesh; John, Theresa A.; Yang, Fen

    2014-05-15

    Angiotensin II (ANG-II) receptors (AGTRs) contribute to renal physiology and pathophysiology, but the underlying mechanisms that regulate AGTR function in glomerular mesangium are poorly understood. Here, we show that AGTR1 is the functional AGTR subtype expressed in neonatal pig glomerular mesangial cells (GMCs). Cyclodextrin (CDX)-mediated cholesterol depletion attenuated cell surface AGTR1 protein expression and ANG-II-induced intracellular Ca{sup 2+} ([Ca{sup 2+}]{sub i}) elevation in the cells. The COOH-terminus of porcine AGTR1 contains a caveolin (CAV)-binding motif. However, neonatal GMCs express CAV-1, but not CAV-2 and CAV-3. Colocalization and in situ proximity ligation assay detected an association between endogenous AGTR1 and CAV-1 in the cells. A synthetic peptide corresponding to the CAV-1 scaffolding domain (CSD) sequence also reduced ANG-II-induced [Ca{sup 2+}]{sub i} elevation in the cells. Real-time imaging of cell growth revealed that ANG-II stimulates neonatal GMC proliferation. ANG-II-induced GMC growth was attenuated by EMD 66684, an AGTR1 antagonist; BAPTA, a [Ca{sup 2+}]{sub i} chelator; KN-93, a Ca{sup 2+}/calmodulin-dependent protein kinase II inhibitor; CDX; and a CSD peptide, but not PD 123319, a selective AGTR2 antagonist. Collectively, our data demonstrate [Ca{sup 2+}]{sub i}-dependent proliferative effect of ANG-II and highlight a critical role for lipid raft microdomains in AGTR1-mediated signal transduction in neonatal GMCs. - Highlights: • AGTR1 is the functional AGTR subtype expressed in neonatal mesangial cells. • Endogenous AGTR1 associates with CAV-1 in neonatal mesangial cells. • Lipid raft disruption attenuates cell surface AGTR1 protein expression. • Lipid raft disruption reduces ANG-II-induced [Ca{sup 2+}]{sub i} elevation in neonatal mesangial cells. • Lipid raft disruption inhibits ANG-II-induced neonatal mesangial cell growth.

  13. Angiotensin II type 1 receptor blocker telmisartan induces apoptosis and autophagy in adult T-cell leukemia cells.

    PubMed

    Kozako, Tomohiro; Soeda, Shuhei; Yoshimitsu, Makoto; Arima, Naomichi; Kuroki, Ayako; Hirata, Shinya; Tanaka, Hiroaki; Imakyure, Osamu; Tone, Nanako; Honda, Shin-Ichiro; Soeda, Shinji

    2016-05-01

    Adult T-cell leukemia/lymphoma (ATL), an aggressive T-cell malignancy that develops after long-term infection with human T-cell leukemia virus (HTLV-1), requires new treatments. Drug repositioning, reuse of a drug previously approved for the treatment of another condition to treat ATL, offers the possibility of reduced time and risk. Among clinically available angiotensin II receptor blockers, telmisartan is well known for its unique ability to activate peroxisome proliferator-activated receptor-γ, which plays various roles in lipid metabolism, cellular differentiation, and apoptosis. Here, telmisartan reduced cell viability and enhanced apoptotic cells via caspase activation in ex vivo peripheral blood monocytes from asymptomatic HTLV-1 carriers (ACs) or via caspase-independent cell death in acute-type ATL, which has a poor prognosis. Telmisartan also induced significant growth inhibition and apoptosis in leukemia cell lines via caspase activation, whereas other angiotensin II receptor blockers did not induce cell death. Interestingly, telmisartan increased the LC3-II-enriched protein fraction, indicating autophagosome accumulation and autophagy. Thus, telmisartan simultaneously caused caspase activation and autophagy. A hypertension medication with antiproliferation effects on primary and leukemia cells is intriguing. Patients with an early diagnosis of ATL are generally monitored until the disease progresses; thus, suppression of progression from AC and indolent ATL to acute ATL is important. Our results suggest that telmisartan is highly effective against primary cells and leukemia cell lines in caspase-dependent and -independent manners, and its clinical use may suppress acute transformation and improve prognosis of patients with this mortal disease. This is the first report demonstrating a cell growth-inhibitory effect of telmisartan in fresh peripheral blood mononuclear cells from leukemia patients. PMID:27419050

  14. Genotoxicity of Advanced Glycation End Products: Involvement of Oxidative Stress and of Angiotensin II Type 1 Receptors

    NASA Astrophysics Data System (ADS)

    Schupp, Nicole; Schinzel, Reinhard; Heidland, August; Stopper, Helga

    2005-06-01

    In patients with chronic renal failure, cancer incidence is increased. This may be related to an elevated level of genomic damage, which has been demonstrated by micronuclei formation as well as by comet assay analysis. Advanced glycation end products (AGEs) are markedly elevated in renal failure. In the comet assay, the model AGEs methylglyoxal- and carboxy(methyl)lysine-modified bovine serum albumin (BSA) induced significant DNA damage in colon, kidney, and liver cells. The addition of antioxidants prevented AGE-induced DNA damage, suggesting enhanced formation of reactive oxygen species (ROS). The coincubation with dimethylfumarate (DMF), an inhibitor of NF-κB translocation, reduced the genotoxic effect, thereby underscoring the key role of NF-κB in this process. One of the genes induced by NF-κB is angiotensinogen. The ensuing proteolytic activity yields angiotensin II, which evokes oxidative stress as well as proinflammatory responses. A modulator of the renin-angiotensin system (RAS), the angiotensin II (Ang II) receptor 1 antagonist, candesartan, yielded a reduction of the AGE-induced DNA damage, connecting the two signal pathways, RAS and AGE signaling. We were able to identify important participants in AGE-induced DNA damage: ROS, NF-κB, and Ang II, as well as modulators to prevent this DNA damage: antioxidants, DMF, and AT1 antagonists.

  15. Human GRK4γ142V Variant Promotes Angiotensin II Type I Receptor-Mediated Hypertension via Renal Histone Deacetylase Type 1 Inhibition.

    PubMed

    Wang, Zheng; Zeng, Chunyu; Villar, Van Anthony M; Chen, Shi-You; Konkalmatt, Prasad; Wang, Xiaoyan; Asico, Laureano D; Jones, John E; Yang, Yu; Sanada, Hironobu; Felder, Robin A; Eisner, Gilbert M; Weir, Matthew R; Armando, Ines; Jose, Pedro A

    2016-02-01

    The influence of a single gene on the pathogenesis of essential hypertension may be difficult to ascertain, unless the gene interacts with other genes that are germane to blood pressure regulation. G-protein-coupled receptor kinase type 4 (GRK4) is one such gene. We have reported that the expression of its variant hGRK4γ(142V) in mice results in hypertension because of impaired dopamine D1 receptor. Signaling through dopamine D1 receptor and angiotensin II type I receptor (AT1R) reciprocally modulates renal sodium excretion and blood pressure. Here, we demonstrate the ability of the hGRK4γ(142V) to increase the expression and activity of the AT1R. We show that hGRK4γ(142V) phosphorylates histone deacetylase type 1 and promotes its nuclear export to the cytoplasm, resulting in increased AT1R expression and greater pressor response to angiotensin II. AT1R blockade and the deletion of the Agtr1a gene normalize the hypertension in hGRK4γ(142V) mice. These findings illustrate the unique role of GRK4 by targeting receptors with opposite physiological activity for the same goal of maintaining blood pressure homeostasis, and thus making the GRK4 a relevant therapeutic target to control blood pressure. PMID:26667412

  16. Involvement of central angiotensin II type 1 receptors in LPS-induced systemic vasopressin release and blood pressure regulation in rats.

    PubMed

    Shimizu, Fumihiro; Kasai, Toshihiro; Takamata, Akira

    2009-06-01

    The purpose of this study was to evaluate the involvement of central angiotensin II (ANG II) and ANG II type 1 (AT(1)) receptors in systemic release of arginine vasopressin (AVP) and blood pressure regulation during endotoxemia. LPS (150 microg/kg) was injected intravenously 30 min after intracerebroventricular (icv) losartan (50 microg), an AT(1) receptor antagonist, or subcutaneous (sc) captopril (50 mg/kg), an angiotensin-converting enzyme inhibitor. Rats with icv and sc saline injections served as control. LPS administration increased plasma AVP concentration from 2.1 +/- 0.2 to 15.2 +/- 2.5 pg/ml (60 min after LPS injection) without significant changes in plasma osmolality or hematocrit. LPS-induced AVP secretion was significantly attenuated by pretreatment with icv losartan (2.3 +/- 0.5 to 3.7 +/- 0.5 pg/ml) but was not attenuated after peripheral captopril treatment (2.2 +/- 0.6 to 17.6 +/- 4.2 pg/ml). LPS administration significantly decreased systolic blood pressure (SBP) by 22.7 +/- 5.4 mmHg after intravenous LPS injection in icv losartan-treated rats, while SBP remained unchanged in vehicle-treated or sc captopril-treated rats by intravenous LPS. These results indicate that central AT(1) receptors, not responsive to peripheral ANG II, play an important role in systemic AVP secretion and maintenance of blood pressure during endotoxemia. PMID:19359612

  17. Angiotensin II type 1 receptor antagonists inhibit basal as well as low-density lipoprotein and platelet-activating factor-stimulated human monocyte chemoattractant protein-1.

    PubMed

    Proudfoot, Julie M; Croft, Kevin D; Puddey, Ian B; Beilin, Lawrence J

    2003-06-01

    Monocyte chemoattractant protein-1 (MCP-1) is a potent chemotactic agent for monocytes and other cells and is thought to be involved in atherosclerosis, recruiting monocytes to the subendothelial space or to the site of inflammation. Angiotensin II has been demonstrated, at least in animal models, to stimulate MCP-1 expression. We investigated the effect of the angiotensin II type 1 (AT1) receptor antagonists irbesartan and losartan on MCP-1 production by freshly isolated human monocytes. Irbesartan and losartan inhibited basal MCP-1 production in a dose-dependent manner. Low-density lipoprotein (LDL) stimulated MCP-1 in a concentration-dependent manner, with 200 microg/ml LDL protein giving a 2-fold increase in MCP-1. Irbesartan and losartan dose dependently blocked LDL-stimulated MCP-1. An angiotensin II type 2 receptor antagonist, S-(+)-1-([4-(dimethylamino)-3-methylphenyl]methyl)-5-(diphenylacetyl)-4,5,6,7-tetrahydro-1H-imidazo(4,5-c)pyridine-6-carboxylic acid (PD123319), had no significant effect on basal MCP-1 levels or LDL-stimulated MCP-1. After noting homology between the AT1 receptor and the platelet-activating factor (PAF) receptor, we showed that irbesartan inhibited both [3H]PAF binding to human monocytes and carbamyl-PAF stimulation of MCP-1. However, irbesartan affinity for the PAF receptor was 700 times less than PAF, suggesting that there may be another mechanism for irbesartan inhibition of PAF-stimulated MCP-1. This is the first report showing that AT1 receptor antagonists inhibit basal as well as LDL- and PAF-stimulated MCP-1 production in freshly isolated human monocytes. PMID:12626661

  18. Involvement of Type 1 Angiontensin II Receptor (AT1) in Cardiovascular Changes Induced by Chronic Emotional Stress: Comparison between Homotypic and Heterotypic Stressors

    PubMed Central

    Costa-Ferreira, Willian; Vieira, Jonas O.; Almeida, Jeferson; Gomes-de-Souza, Lucas; Crestani, Carlos C.

    2016-01-01

    Consistent evidence has shown an important role of emotional stress in pathogenesis of cardiovascular diseases. Additionally, studies in animal models have demonstrated that daily exposure to different stressor (heterotypic stressor) evokes more severe changes than those resulting from repeated exposure to the same aversive stimulus (homotypic stressor), possibly due to the habituation process upon repeated exposure to the same stressor. Despite these pieces of evidence, the mechanisms involved in the stress-evoked cardiovascular dysfunction are poorly understood. Therefore, the present study investigated the involvement of angiotensin II (Ang II) acting on the type 1 Ang II receptor (AT1) in the cardiovascular dysfunctions evoked by both homotypic and heterotypic chronic emotional stresses in rats. For this purpose, we compared the effect of the chronic treatment with the AT1 receptor antagonist losartan (30 mg/kg/day, p.o.) on the cardiovascular and autonomic changes evoked by the heterotypic stressor chronic variable stress (CVS) and the homotypic stressor repeated restraint stress (RRS). RRS increased the sympathetic tone to the heart and decreased the cardiac parasympathetic activity, whereas CVS decreased the cardiac parasympathetic activity. Additionally, both stressors impaired the baroreflex function. Alterations in the autonomic activity and the baroreflex impairment were inhibited by losartan treatment. Additionally, CVS reduced the body weight and increased the circulating corticosterone; however, these effects were not affected by losartan. In conclusion, these findings indicate the involvement of angiotensin II/AT1 receptors in the autonomic changes evoked by both homotypic and heterotypic chronic stressors. Moreover, the present results provide evidence that the increase in the circulating corticosterone and body weight reduction evoked by heterotypic stressors are independent of AT1 receptors. PMID:27588004

  19. Involvement of Type 1 Angiontensin II Receptor (AT1) in Cardiovascular Changes Induced by Chronic Emotional Stress: Comparison between Homotypic and Heterotypic Stressors.

    PubMed

    Costa-Ferreira, Willian; Vieira, Jonas O; Almeida, Jeferson; Gomes-de-Souza, Lucas; Crestani, Carlos C

    2016-01-01

    Consistent evidence has shown an important role of emotional stress in pathogenesis of cardiovascular diseases. Additionally, studies in animal models have demonstrated that daily exposure to different stressor (heterotypic stressor) evokes more severe changes than those resulting from repeated exposure to the same aversive stimulus (homotypic stressor), possibly due to the habituation process upon repeated exposure to the same stressor. Despite these pieces of evidence, the mechanisms involved in the stress-evoked cardiovascular dysfunction are poorly understood. Therefore, the present study investigated the involvement of angiotensin II (Ang II) acting on the type 1 Ang II receptor (AT1) in the cardiovascular dysfunctions evoked by both homotypic and heterotypic chronic emotional stresses in rats. For this purpose, we compared the effect of the chronic treatment with the AT1 receptor antagonist losartan (30 mg/kg/day, p.o.) on the cardiovascular and autonomic changes evoked by the heterotypic stressor chronic variable stress (CVS) and the homotypic stressor repeated restraint stress (RRS). RRS increased the sympathetic tone to the heart and decreased the cardiac parasympathetic activity, whereas CVS decreased the cardiac parasympathetic activity. Additionally, both stressors impaired the baroreflex function. Alterations in the autonomic activity and the baroreflex impairment were inhibited by losartan treatment. Additionally, CVS reduced the body weight and increased the circulating corticosterone; however, these effects were not affected by losartan. In conclusion, these findings indicate the involvement of angiotensin II/AT1 receptors in the autonomic changes evoked by both homotypic and heterotypic chronic stressors. Moreover, the present results provide evidence that the increase in the circulating corticosterone and body weight reduction evoked by heterotypic stressors are independent of AT1 receptors. PMID:27588004

  20. c-Src regulates clathrin adapter protein 2 interaction with beta-arrestin and the angiotensin II type 1 receptor during clathrin- mediated internalization.

    PubMed

    Fessart, Delphine; Simaan, May; Laporte, Stéphane A

    2005-02-01

    Beta-arrestins are multifunctional adapters involved in the internalization and signaling of G protein-coupled receptors (GPCRs). They target receptors to clathrin-coated pits (CCPs) through binding with clathrin and clathrin adapter 2 (AP-2) complex. They also act as transducers of signaling by recruiting c-Src kinase to certain GPCRs. Here we sought to determine whether c-Src regulates the recruitment of AP-2 to beta-arrestin and the angiotensin II (Ang II) type 1 receptor (AT1R) during internalization. We show that the agonist stimulation of native AT1R in vascular smooth muscle cells (VSMCs) induces the formation of an endogenous complex containing c-Src, beta-arrestins and AP-2. In vitro studies using coimmunoprecipitation experiments and a yeast three-hybrid assay reveal that c-Src stabilizes the agonist-independent association between beta-arrestin2 and the beta-subunit of AP-2 independently of the kinase activity of c-Src. However, although c-Src expression promoted the rapid dissociation of AP-2 from both beta-arrestin and AT1R after receptor stimulation, a kinase-inactive mutant of c-Src failed to induce the dissociation of AP-2 from the agonist-occupied receptor. Thus, the consequence of c-Src in regulating the dissociation of AP-2 from the receptor was also examined on the internalization of AT1R by depleting c-Src in human embryonic kidney (HEK) 293 cells using a small interfering RNA strategy. Experiments in c-Src depleted cells reveal that AT1R remained mostly colocalized with AP-2 at the plasma membrane after Ang II stimulation, consistent with the observed delay in receptor internalization. Moreover, coimmunoprecipitation experiments in c-Src depleted HEK 293 cells and VSMCs showed an increased association of AP-2 to the agonist-occupied AT1R and beta-arrestin, respectively. Together, our results support a role for c-Src in regulating the dissociation of AP-2 from agonist-occupied AT1R and beta-arrestin during the clathrin-mediated internalization

  1. Impact of peroxisome proliferator-activated receptor γ on angiotensin II type 1 receptor-mediated insulin sensitivity, vascular inflammation and atherogenesis in hypercholesterolemic mice

    PubMed Central

    Becher, Ulrich M.; Camara, Bakary; Yildirimtürk, Cihan; Aksoy, Adem; Kebschull, Moritz; Werner, Nikos; Nickenig, Georg; Müller, Cornelius

    2015-01-01

    Introduction The angiotensin II type 1 receptor (AT1R) and the peroxisome proliferator-activated receptor γ (PPARγ) have been implicated in the pathogenesis of atherosclerosis. A number of studies have reported that AT1R inhibition or genetic AT1R disruption and PPARγ activation inhibit vascular inflammation and improve glucose and lipid metabolism, underscoring a molecular interaction of AT1R and PPARγ. We here analyzed the hypothesis that vasculoprotective anti-inflammatory and metabolic effects of AT1R inhibition are mediated by PPARγ. Material and methods Female ApoE–/–/AT1R–/– mice were fedwith a high-fat and cholesterol-rich diet and received continuous treatment with the selective PPARγ antagonist GW9662 or vehicle at a rate of 700 ng/kg/min for 4 weeks using subcutaneously implanted osmotic mini-pumps. Additionally, one group of female ApoE–/– mice served as a control group. After treatment for 4 weeks mice were sacrificed and read-outs (plaque development, vascular inflammation and insulinsensitivity) were performed. Results Using AT1R deficient ApoE–/– mice (ApoE–/–/AT1R–/– mice) we found decreased cholesterol-induced endothelial dysfunction and atherogenesis compared to ApoE–/– mice. Inhibition of PPARγ by application of the specific PPARγ antagonist GW9662 significantly abolished the anti-atherogenic effects of AT1R deficiency in ApoE–/–/AT1R–/– mice (plaque area as % of control: ApoE–/–: 39 ±5%; ApoE–/–/AT1R–/–: 17 ±7%, p = 0.044 vs. ApoE–/–; ApoE–/–/AT1R–/– + GW9662: 31 ±8%, p = 0.047 vs. ApoE–/–/AT1R–/–). Focusing on IL6 as a pro-inflammatory humoral marker we detected significantly increased IL-6 levels in GW9662-treated animals (IL-6 in pg/ml: ApoE–/–: 230 ±16; ApoE–/–/AT1R–/–: 117 ±20, p = 0.01 vs. ApoE–/–; ApoE–/–/AT1R–/– + GW9662: 199 ±20, p = 0.01 vs. ApoE–/–/AT1R–/–), while the anti-inflammatory marker IL-10 was significantly

  2. In vivo imaging of oxidative stress in the kidney of diabetic mice and its normalization by angiotensin II type 1 receptor blocker

    SciTech Connect

    Sonta, Toshiyo; Inoguchi, Toyoshi . E-mail: toyoshi@intmed3.med.kyushu-u.ac.jp; Matsumoto, Shingo; Yasukawa, Keiji; Inuo, Mieko; Tsubouchi, Hirotaka; Sonoda, Noriyuki; Kobayashi, Kunihisa; Utsumi, Hideo; Nawata, Hajime

    2005-05-06

    This study was undertaken to evaluate oxidative stress in the kidney of diabetic mice by electron spin resonance (ESR) imaging technique. Oxidative stress in the kidney was evaluated as organ-specific reducing activity with the signal decay rates of carbamoyl-PROXYL probe using ESR imaging. The signal decay rates were significantly faster in corresponding image pixels of the kidneys of streptozotocin-induced diabetic mice than in those of controls. This technique further demonstrated that administration of angiotensin II type 1 receptor blocker (ARB), olmesartan (5 mg/kg), completely restored the signal decay rates in the diabetic kidneys to control values. In conclusion, this study provided for the first time the in vivo evidence for increased oxidative stress in the kidneys of diabetic mice and its normalization by ARB as evaluated by ESR imaging. This technique would be useful as a means of further elucidating the role of oxidative stress in diabetic nephropathy.

  3. Pre-transplant angiotensin receptor II type 1 antibodies and risk of post-transplant focal segmental glomerulosclerosis recurrence.

    PubMed

    Mujtaba, Muhammad A; Sharfuddin, Asif A; Book, Benita L; Goggins, William C; Khalil, Ali A; Mishler, Dennis P; Fridell, Johnathan A; Yaqub, Muhammad S; Taber, Tim E

    2015-07-01

    Post-kidney transplant recurrence of focal segmental glomerulosclerosis (FSGS) is a major problem. AT1R is expressed on podocyte; its expression is elevated in the proteinuric state. Using an ELISA, we tested pre-transplant sera of 28 patients with history of idiopathic FSGS for anti-AT1R levels and serum soluble urokinase-type plasminogen activator receptor (suPAR) as a biomarker for risk of recurrence of FSGS. Sera from 11 patients with polycystic kidney disease (PKD) were used as controls. Twelve patients had biopsy proven post-transplant FSGS recurrence at 1.5 months. No difference was found in the pre-transplant suPAR levels of FSGS patients (5993 ± 2292 pg/mL) vs. PKD (7334 ± 4538 pg/mL) (p = 0.23). Serum suPAR levels in patients with FSGS recurrence (5786 ± 1899 pg/mL) vs. no FSGS recurrence (6149 ± 2598 pg/mL) (p = 0.69) were not different. Anti-AT1R levels in patients with FSGS were 12.66 ± 11.85 U/mL vs. 8.69 ± 6.52 U/mL in PKD (p = 0.32); however, a difference was found in patients with and without FSGS recurrence 20.41 ± 14.36 U/mL 6.84 ± 4.181 U/mL, respectively (p < 0.01). Area under curve for suPAR and anti-AT1R to predict post-transplant FSGS recurrence was 0.51 and 0.84, respectively. Pre-transplant anti-AT1R levels appear to be a helpful biomarker in identifying patients at high risk of post-transplant FSGS recurrence. PMID:25973696

  4. Characteristics of binding of insulin-like growth factor (IGF)-I and IGF-II analogues to the type 1 IGF receptor determined by BIAcore analysis.

    PubMed

    Forbes, Briony E; Hartfield, Perry J; McNeil, Kerrie A; Surinya, Kathy H; Milner, Steven J; Cosgrove, Leah J; Wallace, John C

    2002-02-01

    Insulin-like growth factor (IGF) binding to the type 1 IGF receptor (IGF1R) elicits mitogenic effects, promotion of differentiation and protection from apoptosis. This study has systematically measured IGF1R binding affinities of IGF-I, IGF-II and 14 IGF analogues to a recombinant high-affinity form of the IGF1R using BIAcore technology. The analogues assessed could be divided into two groups: (a) those designed to investigate binding of IGF-binding protein, which exhibited IGF1R-binding affinities similar to those of IGF-I or IGF-II; (b) those generated to probe IGF1R interactions with greatly reduced IGF1R-binding affinities. The relative binding affinities of IGF-I analogues and IGF-I for the IGF1R determined by BIAcore analysis agreed closely with existing data from receptor-binding assays using cells or tissue membranes, demonstrating that BIAcore technology is a powerful tool for measuring affinities of IGFs for IGF1R. In parallel studies, IGF1R-binding affinities were related to ability to protect against serum withdrawal-induced apoptosis in three different assays including Hoechst 33258 staining, cell survival, and DNA fragmentation assays using the rat pheochromocytoma cell line, PC12. In this model system, IGF-I and IGF-II at low nanomolar concentrations are able to prevent apoptosis completely. We conclude that ability to protect against apoptosis is directly related to ability to bind the IGF1R. PMID:11846798

  5. Cannabinoid receptor type-1: breaking the dogmas

    PubMed Central

    Busquets Garcia, Arnau; Soria-Gomez, Edgar; Bellocchio, Luigi; Marsicano, Giovanni

    2016-01-01

    The endocannabinoid system (ECS) is abundantly expressed in the brain. This system regulates a plethora of physiological functions and is composed of cannabinoid receptors, their endogenous ligands (endocannabinoids), and the enzymes involved in the metabolism of endocannabinoids. In this review, we highlight the new advances in cannabinoid signaling, focusing on a key component of the ECS, the type-1 cannabinoid receptor (CB 1). In recent years, the development of new imaging and molecular tools has demonstrated that this receptor can be distributed in many cell types (e.g., neuronal or glial cells) and intracellular compartments (e.g., mitochondria). Interestingly, cellular and molecular effects are differentially mediated by CB 1 receptors according to their specific localization (e.g., glutamatergic or GABAergic neurons). Moreover, this receptor is expressed in the periphery, where it can modulate periphery-brain connections. Finally, the better understanding of the CB 1 receptor structure led researchers to propose interesting and new allosteric modulators. Thus, the advances and the new directions of the CB 1 receptor field will provide new insights and better approaches to profit from its interesting therapeutic profile. PMID:27239293

  6. The Prognostic Role of Angiotensin II Type 1 Receptor Autoantibody in Non-Gravid Hypertension and Pre-eclampsia: A Meta-analysis and Our Studies.

    PubMed

    Lei, Jinghui; Li, Yafeng; Zhang, Suli; Wu, Ye; Wang, Pengli; Liu, Huirong

    2016-04-01

    Angiotensin II type 1 receptor autoantibody (AT1-AA) is found in patients with non-gravid hypertension or pre-eclampsia, but the relationship is uncertain.The aim of the present study was to assess the association between AT1-AA and high blood pressure using meta-analysis, and to evaluate the prognosis value of AT1-AA for hypertensive diseases.Literature search from PubMed, Embase, and Cochrane databases were conducted using keywords "hypertension" or "pre-eclampsia," "angiotensin II receptor type 1 autoantibody," and its aliases from April 1999 to December 2015.Studies evaluating the association between AT1-AA and non-gravid hypertension or pre-eclampsia were included in this analysis. The quality of the eligible studies was assessed based on the Newcastle-Ottawa Scale with some modifications.Two researchers then independently reviewed all included studies and extracted all relevant data. Association between AT1-AA and hypertension was tested with pooled odds ratios (ORs) and 95% confidence intervals (CIs). Finally, we evaluated whether AT1-AA predicted the prognosis of hypertension by using a summary receiver-operating characteristic (ROC) curve and sensitivity analysis.Ten studies were finally included in this meta-analysis. AT1-AA showed more significant association with pre-eclampsia than that with non-gravid hypertension (pooled OR 32.84, 95% CI 17.19-62.74; and pooled OR 4.18, 95% CI 2.20-7.98, respectively). Heterogeneity among studies was also detected probably due to different hypertensive subtypes and AT1-AA measuring methods. Area under summary ROC curve (AUC) of pre-eclampsia was 0.92 (sensitivity 0.76; specificity 0.86). Area under the ROC curve of overall hypertensive diseases or non-gravid hypertension was lower than that of pre-eclampsia (0.86 and 0.72, respectively) with lower sensitivities (0.46 and 0.26, respectively).The major limitation of this analysis was the publication bias due to lack of unpublished data and the language limitation during

  7. Identification of Distinct Conformations of the Angiotensin-II Type 1 Receptor Associated with the Gq/11 Protein Pathway and the β-Arrestin Pathway Using Molecular Dynamics Simulations*

    PubMed Central

    Cabana, Jérôme; Holleran, Brian; Leduc, Richard; Escher, Emanuel; Guillemette, Gaétan; Lavigne, Pierre

    2015-01-01

    Biased signaling represents the ability of G protein-coupled receptors to engage distinct pathways with various efficacies depending on the ligand used or on mutations in the receptor. The angiotensin-II type 1 (AT1) receptor, a prototypical class A G protein-coupled receptor, can activate various effectors upon stimulation with the endogenous ligand angiotensin-II (AngII), including the Gq/11 protein and β-arrestins. It is believed that the activation of those two pathways can be associated with distinct conformations of the AT1 receptor. To verify this hypothesis, microseconds of molecular dynamics simulations were computed to explore the conformational landscape sampled by the WT-AT1 receptor, the N111G-AT1 receptor (constitutively active and biased for the Gq/11 pathway), and the D74N-AT1 receptor (biased for the β-arrestin1 and -2 pathways) in their apo-forms and in complex with AngII. The molecular dynamics simulations of the AngII-WT-AT1, N111G-AT1, and AngII-N111G-AT1 receptors revealed specific structural rearrangements compared with the initial and ground state of the receptor. Simulations of the D74N-AT1 receptor revealed that the mutation stabilizes the receptor in the initial ground state. The presence of AngII further stabilized the ground state of the D74N-AT1 receptor. The biased agonist [Sar1,Ile8]AngII also showed a preference for the ground state of the WT-AT1 receptor compared with AngII. These results suggest that activation of the Gq/11 pathway is associated with a specific conformational transition stabilized by the agonist, whereas the activation of the β-arrestin pathway is linked to the stabilization of the ground state of the receptor. PMID:25934394

  8. Lack of association of angiotensin II type 1 receptor A1166C gene polymorphism with the risk of end-stage renal disease.

    PubMed

    Mao, Song; Huang, Songming

    2013-10-01

    The association between angiotensin II type 1 receptor (AT1R) A 1166C (rs5186) gene polymorphism and end-stage renal disease (ESRD) risk remains controversial. We aimed to assess the association between AT1R A1166C gene polymorphism and ESRD susceptibility by performing a meta-analysis. Eligible studies were searched according to a predefined criterion using electronic databases. Eight articles were identified for the analysis of the association between AT1R A1166C gene polymorphism and ESRD risk. A allele and AA genotype were not associated with ESRD risk in overall populations, Caucasians and Asians (overall populations: p = 0.834 and 0.832, Caucasians: p = 0.853 and 0.884, Asians: p = 0.243 and 0.982). CC and AC genotype were not associated with ESRD risk in overall populations, Caucasians and Asians (overall populations: p = 0.304 and 0.712, Caucasians: p = 0.510 and 0.987, Asians: p = 0.319 and 0.225). In conclusion, AT1R A1166C gene polymorphism may not be correlated with ESRD risk in overall populations, Caucasians and Asians. However, more studies should be performed in the future. PMID:23902432

  9. Beneficial effects of candesartan, an angiotensin II type 1 receptor blocker, on beta-cell function and morphology in db/db mice.

    PubMed

    Shao, Jiaqing; Iwashita, Noseki; Ikeda, Fuki; Ogihara, Takeshi; Uchida, Toyoyoshi; Shimizu, Tomoaki; Uchino, Hiroshi; Hirose, Takahisa; Kawamori, Ryuzo; Watada, Hirotaka

    2006-06-16

    Several epidemiological studies suggested that treatment with angiotensin II type 1 receptor blocker (ARB) provided a risk reduction of developing type 2 diabetes. In this study, we investigated whether and how ARB treatment can improve abnormalities of pancreatic islets in diabetes state. We randomized db/db mice, a model of type 2 diabetes with obesity, at the age of 8 weeks to receive candesartan, an ARB, for 6 weeks. We also studied age-matched db/misty mice as control. Glucose tolerance test revealed that candesartan treatment improved glucose tolerance with the modest increase in serum insulin level in db/db mice. Concurrently, candesartan increased beta-cell mass, increased staining intensity of insulin, and decreased staining intensity of components of NAD(P)H oxidase, p22phox and gp91phox, and those of oxidative stress markers in beta-cells. These changes were accompanied by reduction of mitochondrial volume. Treatment with candesartan also reduced fibrosis in and around the islets and prevented the loss of endothelial cells in islets. Our results showed that candesartan partially prevented deterioration of glucose tolerance by providing protection against progressive beta-cell damage in diabetes. PMID:16650382

  10. Improved Glucose-Stimulated Insulin Secretion by Selective Intraislet Inhibition of Angiotensin II Type 1 Receptor Expression in Isolated Islets of db/db Mice

    PubMed Central

    Zhang, Zhen; Liu, Chunyan; Gan, Zhenhua; Yi, Qiuyan; Liu, Yanqing; Wang, Yingzhijie; Lu, Bin; Du, Hong

    2013-01-01

    Recent evidence supported the presence of a local renin-angiotensin system (RAS) in the pancreas, which is implicated in many physiological and pathophysiological processes. We utilized small interfering RNA (siRNA) to investigate the effects of angiotensin II type 1 receptor (AT1R) knockdown on glucose-stimulated insulin secretion (GSIS) in isolated islets of db/db mice and to explore the potential mechanisms involved. We found that Ad-siAT1R treatment resulted in a significant decrease both in AT1R mRNA level and in AT1R protein expression level. With downexpression of AT1R, notable increased insulin secretion and decreased glucagon secretion levels were found by perifusion. Simultaneously, significant increased protein levels of IRS-1 (by 85%), IRS-2 (by 95%), PI3K(85) (by 112.5%), and p-Akt2 (by 164%) were found by western blot. And upregulation of both GLUT-2 (by 190%) and GCK (by 121%) was achieved after AT1R inhibition by Ad-siAT1R. Intraislet AT1R expression level is a crucial physiological regulator of insulin sensitivity of β cell itself and thus affects glucose-induced insulin and glucagon release. Therefore, the characteristics of AT1R inhibitors could make it a potential novel therapeutics for prevention and treatment of type 2 diabetes. PMID:24371439

  11. Discovery of a Series of Imidazo[4,5-b]pyridines with Dual Activity at Angiotensin II Type 1 Receptor and Peroxisome Proliferator-Activated Receptor-[gamma

    SciTech Connect

    Casimiro-Garcia, Agustin; Filzen, Gary F.; Flynn, Declan; Bigge, Christopher F.; Chen, Jing; Davis, Jo Ann; Dudley, Danette A.; Edmunds, Jeremy J.; Esmaeil, Nadia; Geyer, Andrew; Heemstra, Ronald J.; Jalaie, Mehran; Ohren, Jeffrey F.; Ostroski, Robert; Ellis, Teresa; Schaum, Robert P.; Stoner, Chad

    2013-03-07

    Mining of an in-house collection of angiotensin II type 1 receptor antagonists to identify compounds with activity at the peroxisome proliferator-activated receptor-{gamma} (PPAR{gamma}) revealed a new series of imidazo[4,5-b]pyridines 2 possessing activity at these two receptors. Early availability of the crystal structure of the lead compound 2a bound to the ligand binding domain of human PPAR{gamma} confirmed the mode of interaction of this scaffold to the nuclear receptor and assisted in the optimization of PPAR{gamma} activity. Among the new compounds, (S)-3-(5-(2-(1H-tetrazol-5-yl)phenyl)-2,3-dihydro-1H-inden-1-yl)-2-ethyl-5-isobutyl-7-methyl-3H-imidazo[4,5-b]pyridine (2l) was identified as a potent angiotensin II type I receptor blocker (IC{sub 50} = 1.6 nM) with partial PPAR{gamma} agonism (EC{sub 50} = 212 nM, 31% max) and oral bioavailability in rat. The dual pharmacology of 2l was demonstrated in animal models of hypertension (SHR) and insulin resistance (ZDF rat). In the SHR, 2l was highly efficacious in lowering blood pressure, while robust lowering of glucose and triglycerides was observed in the male ZDF rat.

  12. Discovery of a series of imidazo[4,5-b]pyridines with dual activity at angiotensin II type 1 receptor and peroxisome proliferator-activated receptor-γ.

    PubMed

    Casimiro-Garcia, Agustin; Filzen, Gary F; Flynn, Declan; Bigge, Christopher F; Chen, Jing; Davis, Jo Ann; Dudley, Danette A; Edmunds, Jeremy J; Esmaeil, Nadia; Geyer, Andrew; Heemstra, Ronald J; Jalaie, Mehran; Ohren, Jeffrey F; Ostroski, Robert; Ellis, Teresa; Schaum, Robert P; Stoner, Chad

    2011-06-23

    Mining of an in-house collection of angiotensin II type 1 receptor antagonists to identify compounds with activity at the peroxisome proliferator-activated receptor-γ (PPARγ) revealed a new series of imidazo[4,5-b]pyridines 2 possessing activity at these two receptors. Early availability of the crystal structure of the lead compound 2a bound to the ligand binding domain of human PPARγ confirmed the mode of interaction of this scaffold to the nuclear receptor and assisted in the optimization of PPARγ activity. Among the new compounds, (S)-3-(5-(2-(1H-tetrazol-5-yl)phenyl)-2,3-dihydro-1H-inden-1-yl)-2-ethyl-5-isobutyl-7-methyl-3H-imidazo[4,5-b]pyridine (2l) was identified as a potent angiotensin II type I receptor blocker (IC(50) = 1.6 nM) with partial PPARγ agonism (EC(50) = 212 nM, 31% max) and oral bioavailability in rat. The dual pharmacology of 2l was demonstrated in animal models of hypertension (SHR) and insulin resistance (ZDF rat). In the SHR, 2l was highly efficacious in lowering blood pressure, while robust lowering of glucose and triglycerides was observed in the male ZDF rat. PMID:21557540

  13. Association of angiotensin converting enzyme and angiotensin II type 1 receptor genotypes with left ventricular function and mass in patients with angiographically normal coronary arteries.

    PubMed Central

    Hamon, M.; Amant, C.; Bauters, C.; Richard, F.; Helbecque, N.; McFadden, E.; Lablanche, J. M.; Bertrand, M.; Amouyel, P.

    1997-01-01

    OBJECTIVE: To analyse the potential association of the angiotensin converting enzyme (ACE) and angiotensin II type 1 receptor (AT1R) gene polymorphisms on left ventricular function and mass in patients with normal coronary arteries. DESIGN: Consecutive sample. SETTING: University hospital. SUBJECTS: 141 consecutive white patients referred for coronary angiography and with angiographically normal coronary arteries. Patients with valvar diseases, cardiomyopathies, or a history of myocardial infarction were excluded. MAIN OUTCOME MEASURES: Left ventricular variables were measured for all patients. The ACE and AT1R genotypes were determined with a polymerase chain reaction based protocol using DNA prepared from white blood cells. A general linear model was used to compare data according to the ACE and to the AT1R genotypes. RESULTS: A strong association was observed between left ventricular mass and systemic hypertension (mean (SD) hypertension: 114 (31) g/m2; no hypertension 98 (23) g/m2; P < 0.003). However, no influence of ACE and AT1R polymorphisms on left ventricular mass was found, regardless of systemic hypertension. The subjects homozygous for the AT1R CC mutation had a significantly lower ejection fraction than those with allele A (AC+AA) (mean (SD) 62(12)% and 68(10)%, respectively, P < 0.05). No synergistic interaction of ACE and AT1R gene polymorphisms on left ventricular function and mass was found. CONCLUSIONS: These data do not support an association of the ACE and AT1R genotypes on left ventricular hypertrophy in white patients with normal coronary arteries. PMID:9227291

  14. Pre-transplant angiotensin II type 1receptor antibodies: a risk factor for decreased kidney graft function in the early post-transplant period?

    PubMed

    Hernández-Méndez, Erick Alejandro; Arreola-Guerra, José Manuel; Morales-Buenrostro, Luis E; Ramírez, Julia B; Calleja, Said; Castelán, Natalia; Salcedo, Isaac; Vilatobá, Mario; Contreras, Alan G; Gabilondo, Bernardo; Granados, Julio; Alberú, Josefina

    2014-01-01

    Angiotensin II type 1 receptor antibodies (AT1Rab) are associated to a significantly lower graft survival and a higher risk of acute rejection after kidney transplantation. This study aimed to evaluate graft function and BPAR during the 1st year post-transplant (PT) in adult kidney transplant recipients (KTR), between 03/2009 and 08/2012. Pre-KT sera were screened for AT1Rab (ELISA) and HLA-DSA (Luminex). Three groups were analyzed: AT1Rab only (n = 13); HLA-DSA only (n = 8); and no AT1Rab or HLA-DSA (n = 90). No differences were observed in clinical characteristics across groups. A higher percentage of BPAR was observed in the AT1Rab positive group, but this difference was not significant. KTR with AT1Rab had a lower mean eGFR (20 mL/min/1.73m2) when compared to KTR with no Abs at 12 months. The significant difference in eGFR was observed since the 1st month PT. Multivariate analysis showed 4 factors independently and significantly associated with eGFR at 12mos PT: BPAR (-18.7 95%, CI -28.2 to -9.26, p<0.001), AT1Rab (-10.51, CI -20.9 to -0.095, p = 0.048), donor age (-0.42, CI -0.75 to -0.103 p = 0.010), and recipient age (-0.36, CI -0.67 to -0.048, p = 0.024). In this study AT1Rab in pre-transplant sera from KTR, was an independent and significant risk factor contributing to a lower eGFR 12 months. PT. This finding deserves to be confirmed in a larger KTR population. PMID:25695237

  15. Central Rho kinase inhibition restores baroreflex sensitivity and angiotensin II type 1 receptor protein imbalance in conscious rabbits with chronic heart failure.

    PubMed

    Haack, Karla K V; Gao, Lie; Schiller, Alicia M; Curry, Pamela L; Pellegrino, Peter R; Zucker, Irving H

    2013-03-01

    The small GTPase RhoA and its associated kinase ROCKII are involved in vascular smooth muscle cell contraction and endothelial NO synthase mRNA destabilization. Overactivation of the RhoA/ROCKII pathway is implicated in several pathologies, including chronic heart failure (CHF), and may contribute to the enhanced sympathetic outflow seen in CHF as a result of decreased NO availability. Thus, we hypothesized that central ROCKII blockade would improve the sympathovagal imbalance in a pacing rabbit model of CHF in an NO-dependent manner. CHF was induced by rapid ventricular pacing and characterized by an ejection fraction of ≤45%. Animals were implanted with an intracerbroventricular cannula and osmotic minipump (rate, 1 μL/h) containing sterile saline, 1.5 µg/kg per day fasudil (Fas, a ROCKII inhibitor) for 4 days or Fas+100 µg/kg per day Nω-Nitro-l-arginine methyl ester hydrochloride, a NO synthase inhibitor. Arterial baroreflex control was assessed by intravenous infusion of sodium nitroprusside and phenylephrine. Fas infusion significantly lowered resting heart rate by decreasing sympathetic and increasing vagal tone. Furthermore, Fas improved baroreflex gain in CHF in an NO-dependent manner. In CHF Fas animals, the decrease in heart rate in response to intravenous metoprolol was similar to Sham and was reversed by Nω-Nitro-l-arginine methyl ester hydrochloride. Fas decreased angiotensin II type 1 receptor and phospho-ERM protein expression and increased endothelial NO synthase expression in the brain stem of CHF animals. These data strongly suggest that central ROCKII activation contributes to cardiac sympathoexcitation in the setting of CHF and that central Fas restores vagal and sympathetic tone in an NO-dependent manner. ROCKII may be a new central therapeutic target in the setting of CHF. PMID:23283363

  16. Association of atrial fibrillation with gene polymorphisms of connexin 40 and angiotensin II receptor type 1 in Chongming adults of Shanghai

    PubMed Central

    Hou, Shuxin; Lu, Yingmin; Huang, Damin; Luo, Xiaohan; Yue, Dongmei; Zhang, Jinchun

    2015-01-01

    Objective: To characterized the gene polymorphisms of connexin 40 (cx40) and angiotensin II receptor type 1 (AT1R) in Chongming adults with atrial fibrillation (AF) and to explore their relationships with AF. Methods: 82 patients with AF, and 82 subjects without AF were enrolled. Polymorphisms of cx40 G-44A and AT1 A1166C were detected. Moreover, several samples were randomly selected to validate the gene polymorphisms of cx40 and AT1. Results: Genotypes AA, AG and GG of cx40 G-44A were found in both AF patients and controls. The frequencies of genotypes AA, AG and GG were 39%, 29% and 32%, respectively, in AF patients and 31%, 35% and 34%, respectively in controls. The frequencies of alleles A and G were 54% and 46%, respectively in AF patients and 48% and 52%, respectively, in controls (P < 0.05). The risk for AF in patients with allele A increased 1.31 times (OR = 1.31, P < 0.05). The frequencies of genotypes AA, AC and CC were 88%, 8% and 4%, respectively in AF patients and 93%, 6% and 1%, respectively in controls. The frequencies of alleles A and C were 92% and 8%, respectively in AF patients and 96% and 4%, respectively in controls (P < 0.05). More AF patients had allele C as compared to controls. The risk for AF increased by 1.43 times in patients with allele C (OR = 1.43, P < 0.05). Conclusion: There were relationships between gene polymorphisms of cx40 and AT1 and AF in Chongming adults. Allele A of cx40 G-44A and allele C of AT1 A1166C significantly increase the risk for AF. PMID:26380021

  17. Design, synthesis, and evaluation of imidazo[4,5-c]pyridin-4-one derivatives with dual activity at angiotensin II type 1 receptor and peroxisome proliferator-activated receptor-γ.

    PubMed

    Casimiro-Garcia, Agustin; Heemstra, Ronald J; Bigge, Christopher F; Chen, Jing; Ciske, Fred A; Davis, Jo Ann; Ellis, Teresa; Esmaeil, Nadia; Flynn, Declan; Han, Seungil; Jalaie, Mehran; Ohren, Jeffrey F; Powell, Noel A

    2013-02-01

    Identification of a series of imidazo[4,5-c]pyridin-4-one derivatives that act as dual angiotensin II type 1 (AT1) receptor antagonists and peroxisome proliferator-activated receptor-γ (PPARγ) partial agonists is described. Starting from a known AT1 antagonist template, conformational restriction was introduced by incorporation of an indane ring that when combined with appropriate substitution at the imidazo[4,5-c]pyridin-4-one provided novel series 5 possessing the desired dual activity. The mode of interaction of this series with PPARγ was corroborated through the X-ray crystal structure of 12b bound to the human PPARγ ligand binding domain. Modulation of activity at both receptors through substitution at the pyridone nitrogen led to the identification of potent dual AT1 antagonists/PPARγ partial agonists. Among them, 21b was identified possessing potent dual pharmacology (AT1 IC(50) = 7 nM; PPARγ EC(50) = 295 nM, 27% max) and good ADME properties. PMID:23265881

  18. A state of reversible compensated ventricular dysfunction precedes pathological remodelling in response to cardiomyocyte-specific activity of angiotensin II type-1 receptor in mice

    PubMed Central

    Frentzou, Georgia A.; Drinkhill, Mark J.; Turner, Neil A.; Ball, Stephen G.; Ainscough, Justin F. X.

    2015-01-01

    ABSTRACT Cardiac dysfunction is commonly associated with high-blood-pressure-induced cardiomyocyte hypertrophy, in response to aberrant renin-angiotensin system (RAS) activity. Ensuing pathological remodelling promotes cardiomyocyte death and cardiac fibroblast activation, leading to cardiac fibrosis. The initiating cellular mechanisms that underlie this progressive disease are poorly understood. We previously reported a conditional mouse model in which a human angiotensin II type-I receptor transgene (HART) was expressed in differentiated cardiomyocytes after they had fully matured, but not during development. Twelve-month-old HART mice exhibited ventricular dysfunction and cardiomyocyte hypertrophy with interstitial fibrosis following full receptor stimulation, without affecting blood pressure. Here, we show that chronic HART activity in young adult mice causes ventricular dysfunction without hypertrophy, fibrosis or cardiomyocyte death. Dysfunction correlated with reduced expression of pro-hypertrophy markers and increased expression of pro-angiogenic markers in the cardiomyocytes experiencing increased receptor load. This stimulates responsive changes in closely associated non-myocyte cells, including the downregulation of pro-angiogenic genes, a dampened inflammatory response and upregulation of Tgfβ. Importantly, this state of compensated dysfunction was reversible. Furthermore, increased stimulation of the receptors on the cardiomyocytes caused a switch in the secondary response from the non-myocyte cells. Progressive cardiac remodelling was stimulated through hypertrophy and death of individual cardiomyocytes, with infiltration, proliferation and activation of fibroblast and inflammatory cells, leading to increased angiogenic and inflammatory signalling. Together, these data demonstrate that a state of pre-hypertrophic compensated dysfunction can exist in affected individuals before common markers of heart disease are detectable. The data also suggest that

  19. Xuebijing attenuates hypotension through the upregulation of angiotensin II type 1 receptor-associated protein 1 in rats suffering from heat stroke.

    PubMed

    Pan, Zhiguo; Shao, Yu; Dong, Wenpeng; Liu, Chenxi; Chen, Yi; Jin, Hui; Tang, Liqun; Qiu, Junming; Su, Lei

    2014-12-01

    In our previous study, we demonstrated that Xuebijing (XBJ), a traditional Chinese medicine, attenuates hypotension in rats suffering from heatstroke (HS). However, the underlying mechanisms have not yet been fully elucidated. Thus, the current study was carried out to investigate the mechanisms underlying the effects of XBJ on hypotension n rats suffering from HS. For this purpose, 72 anesthetized rats were randomized into 3 groups and intravenously injected twice daily for 3 days with XBJ (4 ml/kg body weight, XBJ group) or phosphate‑buffered saline (PBS) (HS and sham-operated groups). Models of HS were established in the HS and XBJ groups by placing the rats in a simulated climate chamber with a temperature of 40˚C and a humidity of 60%. Rectal temperature, arterial pressure and heart rate were monitored and recorded. Angiotensin Ⅱ (Ang Ⅱ) levels were increased during HS (shown by ELISA), and XBJ had no apparent effect on Ang Ⅱ levels. The levels of Ang Ⅱ type 1 (AT1) receptor surface expression and AT1 receptor-associated protein 1 (Arap1) were decreased during HS; however, these effects were attenuated by pre-treatment with XBJ (shown by RT-qPCR and western blot analysis). For in vitro experiments, rat macrophages pre-treated with XBJ were stimulated with lipopolysaccharide (LPS). Pre-treatment with XBJ induced a marked inhibitory effect on the release of pro-inflammatory cytokines in the LPS-stimulated macrophages. Furthermore, XBJ inhibited the activation of nuclear factor κB (NF-κB) induced by LPS in the macrophages. Taken together, our data demonstrate that XBJ promotes Arap1 expression by inhibiting the activation of the NF-κB signaling pathway and the release of pro-inflammatory cytokines, which may be the molecular mechanisms through which XBJ alleviates blood pressure reduction in rats suffering from HS. PMID:25270312

  20. Effect of nuclear factor-κB and angiotensin II receptor type 1 on the pathogenesis of rat non-alcoholic fatty liver disease

    PubMed Central

    Tan, Dao-Yu; Shi, Hai-Yan; Li, Chang-Ping; Zhong, Xiao-Ling; Kang, Ming

    2015-01-01

    AIM: To investigate the roles of nuclear factor (NF)-κB and angiotensin II receptor type 1 (AT1R) in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). METHODS: Forty-two healthy adult male Sprague-Dawley rats were randomly divided into three groups: the control group (normal diet), the model group, and the intervention group (10 wk of a high-fat diet feeding, followed by an intraperitoneal injection of PDTC); 6 rats in each group were sacrificed at 6, 10, and 14 wk. After sacrifice, liver tissue was taken, paraffin sections of liver tissue specimens were prepared, hematoxylin and eosin (HE) staining was performed, and pathological changes in liver tissue (i.e., liver fibrosis) were observed by light microscopy. NF-κB expression in liver tissue was detected by immunohistochemistry, and the expression of AT1R in the liver tissue was detected by reverse transcription-polymerase chain reaction (RT-PCR). The data are expressed as mean ± SD. A two-sample t test was used to compare the control group and the model group at different time points, paired t tests were used to compare the differences between the intervention group and the model group, and analysis of variance was used to compare the model group with the control group. Homogeneity of variance was analyzed with single factor analysis of variance. H variance analysis was used to compare the variance. P < 0.05 was considered statistically significant. RESULTS: The NAFLD model was successful after 6 wk and 10 wk. Liver fibrosis was found in four rats in the model group, but in only one rat in the intervention group at 14 wk. Liver steatosis, inflammation, and fibrosis were gradually increased throughout the model. In the intervention group, the body mass, rat liver index, serum lipid, and transaminase levels were not increased compared to the model group. In the model group, the degree of liver steatosis was increased at 6, 10, and 14 wk, and was significantly higher than in the control group (P < 0

  1. Angiotensin II receptor type 1 blockade decreases CTGF/CCN2-mediated damage and fibrosis in normal and dystrophic skeletal muscles

    PubMed Central

    Cabello-Verrugio, Claudio; Morales, María Gabriela; Cabrera, Daniel; Vio, Carlos P; Brandan, Enrique

    2012-01-01

    Abstract Connective tissue growth factor (CTGF/CCN-2) is mainly involved in the induction of extracellular matrix (ECM) proteins. The levels of CTGF correlate with the degree and severity of fibrosis in many tissues, including dystrophic skeletal muscle. The CTGF overexpression in tibialis anterior skeletal muscle using an adenoviral vector reproduced many of the features observed in dystrophic muscles including muscle damage and regeneration, fibrotic response and decrease in the skeletal muscle strength. The renin–angiotensin system is involved in the genesis and progression of fibrotic diseases through its main fibrotic components angiotensin-II and its transducer receptor AT-1. The use of AT-1 receptor blockers (ARB) has been shown to decrease fibrosis. In this paper, we show the effect of AT-1 receptor blockade on CTGF-dependent biological activity in skeletal muscle cells as well as the response to CTGF overexpression in normal skeletal muscle. Our results show that in myoblasts ARB decreased CTGF-mediated increase of ECM protein levels, extracellular signal regulated kinases 1/2 (ERK-1/2) phosphorylation and stress fibres formation. In tibialis anterior muscle overexpressing CTGF using an adenovirus, ARB treatment decreased CTGF-mediated increase of ECM molecules, α-SMA and ERK-1/2 phosphorylation levels. Quite remarkable, ARB was able to prevent the loss of contractile force of tibialis anterior muscles overexpressing CTGF. Finally, we show that ARB decreased the levels of fibrotic proteins, CTGF and ERK-1/2 phosphorylation augmented in a dystrophic skeletal muscle from mdx mice. We propose that ARB is a novel pharmacological tool that can be used to decrease the fibrosis induced by CTGF in skeletal muscle associated with muscular dystrophies. PMID:21645240

  2. Exercise training attenuates age-dependent elevation of angiotensin II type 1 receptor and Nox2 signaling in the rat heart.

    PubMed

    Lee, Yang; Kwak, Hyo-Bum; Hord, Jeff; Kim, Jong-Hee; Lawler, John M

    2015-10-01

    Fibrosis of the aging heart impedes cardiac function and increases the risk of arrhythmias and heart disease. Previously, we demonstrated that exercise-induced reduction of collagen I in the aging heart was linked to a suppression of oxidative stress and transforming growth factor-beta (TGF-ß). The renin-angiotensin II system (RAS) increases oxidative stress via NADPH oxidase-2 (Nox2) and thus elevates TGF-ß and collagen accumulation. Therefore, we tested the hypothesis that exercise training would alleviate age-related upregulation of the angiotensin II receptor I (AT1R) and NADPH oxidase-2 (Nox2), concomitant with suppression of TGF-β and fibrosis. Young (3 months, n=20) and old (31 months, n=20) Fischer 344 ×B rown Norway F1 (FBNF1) hybrid rats were assigned into sedentary and exercise groups, with exercise training rats training on a treadmill 45 min/day, 5 days/week for the next 12 weeks. Exercise training mitigated age-related upregulation of AT1R, Nox2 activity, and Nox2 subunits gp91phox and p47phox. Exercise training also attenuated TGF-ß positive staining and downstream effectors of fibrosis in the aging heart: connective tissue growth factor, phosphorylation of Smad2 at Ser423, myofibroblast proliferation, and collagen I-positive staining. Our results are consistent with the hypothesis that exercise training protects against age-dependent cardiac fibrosis by suppressing AT1R and Nox2 as part of a RAS-Nox2-TGF-β pathway. PMID:26239262

  3. Overexpression of angiotensin II type 1 receptor in breast cancer cells induces epithelial-mesenchymal transition and promotes tumor growth and angiogenesis.

    PubMed

    Oh, Eunhye; Kim, Ji Young; Cho, Youngkwan; An, Hyunsook; Lee, Nahyun; Jo, Hunho; Ban, Changill; Seo, Jae Hong

    2016-06-01

    The angiotensin II type I receptor (AGTR1) has been implicated in diverse aspects of human disease, from the regulation of blood pressure and cardiovascular homeostasis to cancer progression. We sought to investigate the role of AGTR1 in cell proliferation, epithelial-mesenchymal transition (EMT), migration, invasion, angiogenesis and tumor growth in the breast cancer cell line MCF7. Stable overexpression of AGTR1 was associated with accelerated cell proliferation, concomitant with increased expression of survival factors including poly(ADP-ribose) polymerase (PARP) and X-linked inhibitor of apoptosis (XIAP), as well as extracellular signal-regulated kinase (ERK) activation. AGTR1-overexpressing MCF7 cells were more aggressive than their parent line, with significantly increased activity in migration and invasion assays. These observations were associated with changes in EMT markers, including reduced E-cadherin expression and increased p-Smad3, Smad4 and Snail levels. Treatment with the AGTR1 antagonist losartan attenuated these effects. AGTR1 overexpression also accelerated tumor growth and increased Ki-67 expression in a xenograft model. This was associated with increased tumor angiogenesis, as evidenced by a significant increase in microvessels in the intratumoral and peritumoral areas, and enhanced tumor invasion, with the latter response associated with increased EMT marker expression and matrix metallopeptidase 9 (MMP-9) upregulation. In vivo administration of losartan significantly reduced both tumor growth and angiogenesis. Our findings suggest that AGTR1 plays a significant role in tumor aggressiveness, and its inhibition may have therapeutic implications. PMID:26975580

  4. TSH receptor antibodies in subjects with type 1 diabetes mellitus.

    PubMed

    Unnikrishnan, Ambika G; Kumaravel, Velayutham; Nair, Vasantha; Rao, Ananth; Jayakumar, Rohini V; Kumar, Harish; Sanjeevi, Carani B

    2006-10-01

    The research was undertaken to study the prevalence of TSH receptor antibody positivity in patients with type 1 diabetes. A total of 74 subjects with type 1 diabetes were enrolled in this cross-sectional study. Thyroid function test and assessment of thyroid autoimmunity with anti-TPO and TSH receptor antibody were done in all patients. A total of 33 males and 41 females with type 1 diabetes were studied. The prevalence of TSH receptor antibody positivity alone was 18%. The prevalence of thyroid autoimmunity with anti-TPO as a marker was 28%; the prevalence increased to 43% when TSH receptor antibody was also measured. Majority of the subjects with antithyroid antibody positivity were also positive for GAD65 antibodies. As a significant proportion of type 1 diabetic subjects have positivity to TSH receptor antibody, we suggest that larger studies should be conducted to study the benefits of TSH receptor antibody-based screening for thyroid dysfunction in type 1 diabetic subjects. As the TSH receptor antibodies could be of the stimulating or of the blocking type, subjects with antibody positivity could be at risk of developing hyperthyroidism or hypothyroidism. PMID:17130558

  5. Tuning properties and dynamic range of type 1 vomeronasal receptors

    PubMed Central

    Haga-Yamanaka, Sachiko; Ma, Limei; Yu, C. Ron

    2015-01-01

    The mouse vomeronasal organ (VNO) expresses chemosensory receptors that detect intra-species as well as inter-species cues. The vomeronasal neurons are thought to be highly selective in their responses. The tuning properties of individual receptors remain difficult to characterize due to the lack of a robust heterologous expression system. Here, we take a transgenic approach to ectopically express two type 1 vomeronasal receptors in the mouse VNO and characterize their responses to steroid compounds. We find that V1rj2 and V1rj3 are sensitive to two sulfated estrogens (SEs) and can be activated by a broad variety of sulfated and glucuronidated steroids at high concentrations. Individual neurons exhibit narrow range of concentration-dependent activation. Collectively, a neuronal population expressing the same receptor covers a wide dynamic range in their responses to SEs. These properties recapitulate the response profiles of endogenous neurons to SEs. PMID:26236183

  6. Tuning properties and dynamic range of type 1 vomeronasal receptors.

    PubMed

    Haga-Yamanaka, Sachiko; Ma, Limei; Yu, C Ron

    2015-01-01

    The mouse vomeronasal organ (VNO) expresses chemosensory receptors that detect intra-species as well as inter-species cues. The vomeronasal neurons are thought to be highly selective in their responses. The tuning properties of individual receptors remain difficult to characterize due to the lack of a robust heterologous expression system. Here, we take a transgenic approach to ectopically express two type 1 vomeronasal receptors in the mouse VNO and characterize their responses to steroid compounds. We find that V1rj2 and V1rj3 are sensitive to two sulfated estrogens (SEs) and can be activated by a broad variety of sulfated and glucuronidated steroids at high concentrations. Individual neurons exhibit narrow range of concentration-dependent activation. Collectively, a neuronal population expressing the same receptor covers a wide dynamic range in their responses to SEs. These properties recapitulate the response profiles of endogenous neurons to SEs. PMID:26236183

  7. Maternal Treatment with Agonistic Autoantibodies against Type-1 Angiotensin II Receptor in Late Pregnancy Increases Apoptosis of Myocardial Cells and Myocardial Susceptibility to Ischemia-Reperfusion Injury in Offspring Rats

    PubMed Central

    Wang, Xiaofang; Zheng, Yanqian; Zhang, Qiaoyan; Zhi, Jianming

    2013-01-01

    Epidemiological studies have demonstrated that offspring born to mothers preeclampsia (PE) are at increased risk for developing cardiovascular diseases after birth, but the underlying mechanism is unknown. Angiotensin II receptor type 1 autoantibody (AT1-AA), an agonist acting via activation of the AT1 receptor, is believed to be involved in the pathogenesis of both PE and fetal growth restriction. The aim of the present study was to confirm the hypothesis that prenatal AT1-AA exposure increases the heart susceptibility to ischemia/reperfusion injury (IRI) in the offspring in an AT1-AA-induced animal model of PE, and determine whether or not the increase of maternal AT1-AA level is a factor contributing to sustained abnormalities of the heart structure during infancy. The hearts of 45-day-old offspring rats were studied using Langendorff preparation to determine the susceptibility of the heart to IRI. The results showed that the body weight of the maternal rats was not significantly different between the study and control groups, but the body weight of their offspring in AT1-AA group was decreased slightly at day 21 of gestational age, and at day 3 after birth. Although the heart weight index was not significantly affected at all ages examined, AT1-AA significantly increased the size of myocardial cells of the left ventricle (LV) at the age of 45 days. AT1-AA gained access to fetal circulation via the placenta and induced apoptosis of fetal myocardial cells. AT1-AA also significantly delayed recovery from IRI and affected the LV function of 45-day-old offspring. This was associated with a significant increase in IRI-induced LV myocardial infarct size. These results suggest that AT1-AA induced abnormal apoptosis of fetal myocardial cells during the fetal period and increased the cardiac susceptibility to IRI in adult offspring. PMID:24278308

  8. 20-Hydroxyeicosatetraenoic Acid (HETE)-dependent Hypertension in Human Cytochrome P450 (CYP) 4A11 Transgenic Mice: NORMALIZATION OF BLOOD PRESSURE BY SODIUM RESTRICTION, HYDROCHLOROTHIAZIDE, OR BLOCKADE OF THE TYPE 1 ANGIOTENSIN II RECEPTOR.

    PubMed

    Savas, Üzen; Wei, Shouzou; Hsu, Mei-Hui; Falck, John R; Guengerich, F Peter; Capdevila, Jorge H; Johnson, Eric F

    2016-08-01

    Male and female homozygous 129/Sv mice carrying four copies of the human cytochrome P450 4A11 gene (CYP4A11) under control of its native promoter (B-129/Sv-4A11(+/+)) develop hypertension (142 ± 8 versus 113 ± 7 mm Hg systolic blood pressure (BP)), and exhibit increased 20-hydroxyeicosatetraenoic acid (20-HETE) in kidney and urine. The hypertension is reversible by a low-sodium diet and by the CYP4A inhibitor HET0016. B-129/Sv-4A11(+/+) mice display an 18% increase of plasma potassium (p < 0.02), but plasma aldosterone, angiotensin II (ANGII), and renin activities are unchanged. This phenotype resembles human genetic disorders with elevated activity of the sodium chloride co-transporter (NCC) and, accordingly, NCC abundance is increased by 50% in transgenic mice, and NCC levels are normalized by HET0016. ANGII is known to increase NCC abundance, and renal mRNA levels of its precursor angiotensinogen are increased 2-fold in B-129/Sv-4A11(+/+), and blockade of the ANGII receptor type 1 with losartan normalizes BP. A pro-hypertensive role for 20-HETE was implicated by normalization of BP and reversal of renal angiotensin mRNA increases by administration of the 20-HETE antagonists 2-((6Z,15Z)-20-hydroxyicosa-6,15-dienamido)acetate or (S)-2-((6Z,15Z)-20-hydroxyicosa-6,15-dienamido)succinate. SGK1 expression is also increased in B-129/Sv-4A11(+/+) mice and paralleled increases seen for NCC. Losartan, HET0016, and 20-HETE antagonists each normalized SGK1 mRNA expression. These results point to a potential 20-HETE dependence of intrarenal angiotensinogen production and ANGII receptor type 1 activation that are associated with increases in NCC and SGK1 and identify elevated P450 4A11 activity and 20-HETE as potential risk factors for salt-sensitive human hypertension by perturbation of the renal renin-angiotensin axis. PMID:27298316

  9. Microbiota regulates type 1 diabetes through Toll-like receptors

    PubMed Central

    Burrows, Michael P.; Volchkov, Pavel; Kobayashi, Koichi S.; Chervonsky, Alexander V.

    2015-01-01

    Deletion of the innate immune adaptor myeloid differentiation primary response gene 88 (MyD88) in the nonobese diabetic (NOD) mouse model of type 1 diabetes (T1D) results in microbiota-dependent protection from the disease: MyD88-negative mice in germ-free (GF), but not in specific pathogen-free conditions develop the disease. These results could be explained by expansion of particular protective bacteria (“specific lineage hypothesis”) or by dominance of negative (tolerizing) signaling over proinflammatory signaling (“balanced signal hypothesis”) in mutant mice. Here we found that colonization of GF mice with a variety of intestinal bacteria was capable of reducing T1D in MyD88-negative (but not wild-type NOD mice), favoring the balanced signal hypothesis. However, the receptors and signaling pathways involved in prevention or facilitation of the disease remained unknown. The protective signals triggered by the microbiota were revealed by testing NOD mice lacking MyD88 in combination with knockouts of several critical components of innate immune sensing for development of T1D. Only MyD88- and TIR-domain containing adapter inducing IFN β (TRIF) double deficient NOD mice developed the disease. Thus, TRIF signaling (likely downstream of Toll-like receptor 4, TLR4) serves as one of the microbiota-induced tolerizing pathways. At the same time another TLR (TLR2) provided prodiabetic signaling by controlling the microbiota, as reduction in T1D incidence caused by TLR2 deletion was reversed in GF TLR2-negative mice. Our results support the balanced signal hypothesis, in which microbes provide signals that both promote and inhibit autoimmunity by signaling through different receptors, including receptors of the TLR family. PMID:26216961

  10. Adenosine, type 1 receptors: role in proximal tubule Na+ reabsorption.

    PubMed

    Welch, W J

    2015-01-01

    Adenosine type 1 receptor (A1 -AR) antagonists induce diuresis and natriuresis in experimental animals and humans. Much of this effect is due to inhibition of A1 -ARs in the proximal tubule, which is responsible for 60-70% of the reabsorption of filtered Na(+) and fluid. Intratubular application of receptor antagonists indicates that A1 -AR mediates a portion of Na(+) uptake in PT and PT cells, via multiple transport systems, including Na(+) /H(+) exchanger-3 (NHE3), Na(+) /PO4(-) co-transporter and Na(+) -dependent glucose transporter, SGLT. Renal microperfusion and recollection studies have shown that fluid reabsorption is reduced by A1 -AR antagonists and is lower in A1 -AR KO mice, compared to WT mice. Absolute proximal reabsorption (APR) measured by free-flow micropuncture is equivocal, with studies that show either lower APR or similar APR in A1 -AR KO mice, compared to WT mice. Inhibition of A1 -ARs lowers elevated blood pressure in models of salt-sensitive hypertension, partially due to their effects in the proximal tubule. PMID:25345761

  11. Activation of neurotensin receptor type 1 attenuates locomotor activity.

    PubMed

    Vadnie, Chelsea A; Hinton, David J; Choi, Sun; Choi, YuBin; Ruby, Christina L; Oliveros, Alfredo; Prieto, Miguel L; Park, Jun Hyun; Choi, Doo-Sup

    2014-10-01

    Intracerebroventricular administration of neurotensin (NT) suppresses locomotor activity. However, the brain regions that mediate the locomotor depressant effect of NT and receptor subtype-specific mechanisms involved are unclear. Using a brain-penetrating, selective NT receptor type 1 (NTS1) agonist PD149163, we investigated the effect of systemic and brain region-specific NTS1 activation on locomotor activity. Systemic administration of PD149163 attenuated the locomotor activity of C57BL/6J mice both in a novel environment and in their homecage. However, mice developed tolerance to the hypolocomotor effect of PD149163 (0.1 mg/kg, i.p.). Since NTS1 is known to modulate dopaminergic signaling, we examined whether PD149163 blocks dopamine receptor-mediated hyperactivity. Pretreatment with PD149163 (0.1 or 0.05 mg/kg, i.p.) inhibited D2R agonist bromocriptine (8 mg/kg, i.p.)-mediated hyperactivity. D1R agonist SKF-81297 (8 mg/kg, i.p.)-induced hyperlocomotion was only inhibited by 0.1 mg/kg of PD149163. Since the nucleus accumbens (NAc) and medial prefrontal cortex (mPFC) have been implicated in the behavioral effects of NT, we examined whether microinjection of PD149163 into these regions reduces locomotion. Microinjection of PD149163 (2 pmol) into the NAc, but not the mPFC suppressed locomotor activity. In summary, our results indicate that systemic and intra-NAc activation of NTS1 is sufficient to reduce locomotion and NTS1 activation inhibits D2R-mediated hyperactivity. Our study will be helpful to identify pharmacological factors and a possible therapeutic window for NTS1-targeted therapies for movement disorders. PMID:24929110

  12. Mineralocorticoid Receptor Mutations and a Severe Recessive Pseudohypoaldosteronism Type 1

    PubMed Central

    Hubert, Edwige-Ludiwyne; Teissier, Raphaël; Fernandes-Rosa, Fábio L.; Fay, Michel; Rafestin-Oblin, Marie-Edith; Jeunemaitre, Xavier; Metz, Chantal; Escoubet, Brigitte

    2011-01-01

    Pseudohypoaldosteronism type 1 (PHA1) is a rare genetic disease of mineralocorticoid resistance characterized by salt wasting and failure to thrive in infancy. Here we describe the first case of a newborn with severe recessive PHA1 caused by two heterozygous mutations in NR3C2, gene coding for the mineralocorticoid receptor (MR). Independent segregation of the mutations occurred in the family, with p.Ser166X being transmitted from the affected father and p.Trp806X from the asymptomatic mother Whereas the truncated MR166X protein was degraded, MR806X was expressed both at the mRNA and protein level. Functional studies demonstrated that despite its inability to bind aldosterone, MR806X had partial ligand-independent transcriptional activity. Partial nuclear localization of MR806X in the absence of hormone was identified as a prerequisite to initiate transcription. This exceptional case broadens the spectrum of clinical phenotypes of PHA1 and demonstrates that minimal residual activity of MR is compatible with life. It also suggests that rare hypomorphic NR3C2 alleles may be more common than expected from the prevalence of detected PHA1 cases. This might prove relevant for patient's care in neonatal salt losing disorders and may affect renal salt handling and blood pressure in the general population. PMID:21903996

  13. Aspirin suppresses cardiac fibroblast proliferation and collagen formation through downregulation of angiotensin type 1 receptor transcription

    SciTech Connect

    Wang, Xianwei Lu, Jingjun; Khaidakov, Magomed; Mitra, Sona; Ding, Zufeng; Raina, Sameer; Goyal, Tanu; Mehta, Jawahar L.

    2012-03-15

    Aspirin (acetyl salicylic acid, ASA) is a common drug used for its analgesic and antipyretic effects. Recent studies show that ASA not only blocks cyclooxygenase, but also inhibits NADPH oxidase and resultant reactive oxygen species (ROS) generation, a pathway that underlies pathogenesis of several ailments, including hypertension and tissue remodeling after injury. In these disease states, angiotensin II (Ang II) activates NADPH oxidase via its type 1 receptor (AT1R) and leads to fibroblast growth and collagen synthesis. In this study, we examined if ASA would inhibit NADPH oxidase activation, upregulation of AT1R transcription, and subsequent collagen generation in mouse cardiac fibroblasts challenged with Ang II. Mouse heart fibroblasts were isolated and treated with Ang II with or without ASA. As expected, Ang II induced AT1R expression, and stimulated cardiac fibroblast growth and collagen synthesis. The AT1R blocker losartan attenuated these effects of Ang II. Similarly to losartan, ASA, and its SA moiety suppressed Ang II-mediated AT1R transcription and fibroblast proliferation as well as expression of collagens and MMPs. ASA also suppressed the expression of NADPH oxidase subunits (p22{sup phox}, p47{sup phox}, p67{sup phox}, NOX2 and NOX4) and ROS generation. ASA did not affect total NF-κB p65, but inhibited its phosphorylation and activation. These observations suggest that ASA inhibits Ang II-induced NADPH oxidase expression, NF-κB activation and AT1R transcription in cardiac fibroblasts, and fibroblast proliferation and collagen expression. The critical role of NADPH oxidase activity in stimulation of AT1R transcription became apparent in experiments where ASA also inhibited AT1R transcription in cardiac fibroblasts challenged with H{sub 2}O{sub 2}. Since SA had similar effect as ASA on AT1R expression, we suggest that ASA's effect is mediated by its SA moiety. -- Highlights: ► Aspirin in therapeutic concentrations decreases mouse cardiac fibroblast

  14. Tannic acid down-regulates the angiotensin type 1 receptor through a MAPK-dependent mechanism.

    PubMed

    Yesudas, Rekha; Gumaste, Upendra; Snyder, Russell; Thekkumkara, Thomas

    2012-03-01

    In the present study, we investigated the effects of tannic acid (TA), a hydrolysable polyphenol, on angiotensin type 1 receptor (AT1R) expression in continuously passaged rat liver epithelial cells. Under normal conditions, exposure of cells to TA resulted in the down-regulation of AT1R-specific binding in concentrations ranging from 12.5-100 μg/ml (7.34-58.78 μm) over a time period of 2-24 h with no change in receptor affinity to angiotensin II (AngII). The inhibitory effect of TA on AT1R was specific and reversible. In TA-treated cells, we observed a significant reduction in AngII-mediated intracellular calcium signaling, a finding consistent with receptor down-regulation. Under similar conditions, TA down-regulated AT1R mRNA expression without changing the rate of mRNA degradation, suggesting that TA's effect is mediated through transcriptional inhibition. Cells expressing recombinant AT1R without the native promoter show no change in receptor expression, whereas a pCAT reporter construct possessing the rat AT1R promoter was significantly reduced in activity. Furthermore, TA induced the phosphorylation of MAPK p42/p44. Pretreatment of the cells with a MAPK kinase (MEK)-specific inhibitor PD98059 prevented TA-induced MAPK phosphorylation and down-regulation of the AT1R. Moreover, there was no reduction in AngII-mediated intracellular calcium release upon MEK inhibition, suggesting that TA's observed inhibitory effect is mediated through MEK/MAPK signaling. Our findings demonstrate, for the first time, that TA inhibits AT1R gene expression and cellular response, suggesting the observed protective effects of dietary polyphenols on cardiovascular conditions may be, in part, through inhibition of AT1R expression. PMID:22322600

  15. Angiotensin II type 1 receptor blockade by telmisartan prevents stress-induced impairment of memory via HPA axis deactivation and up-regulation of brain-derived neurotrophic factor gene expression.

    PubMed

    Wincewicz, D; Juchniewicz, A; Waszkiewicz, N; Braszko, J J

    2016-09-01

    Physical and psychological aspects of chronic stress continue to be a persistent clinical problem for which new pharmacological treatment strategies are aggressively sought. By the results of our previous work it has been demonstrated that telmisartan (TLM), an angiotensin type 1 receptor (AT1) blocker (ARB) and partial agonist of peroxisome proliferator-activated receptor gamma (PPARγ), alleviates stress-induced cognitive decline. Understanding of mechanistic background of this phenomenon is hampered by both dual binding sites of TLM and limited data on the consequences of central AT1 blockade and PPARγ activation. Therefore, a critical need exists for progress in the characterization of this target for pro-cognitive drug discovery. An unusual ability of novel ARBs to exert various PPARγ binding activities is commonly being viewed as predominant over angiotensin blockade in terms of neuroprotection. Here we aimed to verify this hypothesis using an animal model of chronic psychological stress (Wistar rats restrained 2.5h daily for 21days) with simultaneous oral administration of TLM (1mg/kg), GW9662 - PPARγ receptor antagonist (0.5mg/kg), or both in combination, followed by a battery of behavioral tests (open field, elevated plus maze, inhibitory avoidance - IA, object recognition - OR), quantitative determination of serum corticosterone (CORT) and evaluation of brain-derived neurotrophic factor (BDNF) gene expression in the medial prefrontal cortex (mPFC) and hippocampus (HIP). Stressed animals displayed decreased recall of the IA behavior (p<0.001), decreased OR (p<0.001), substantial CORT increase (p<0.001) and significantly downregulated expression of BDNF in the mPFC (p<0.001), which were attenuated in rats receiving TLM and TLM+GW9662. These data indicate that procognitive effect of ARBs in stressed subjects do not result from PPAR-γ activation, but AT1 blockade and subsequent hypothalamus-pituitary-adrenal axis deactivation associated with changes in

  16. Endocannabinoids Stimulate Human Melanogenesis via Type-1 Cannabinoid Receptor*

    PubMed Central

    Pucci, Mariangela; Pasquariello, Nicoletta; Battista, Natalia; Di Tommaso, Monia; Rapino, Cinzia; Fezza, Filomena; Zuccolo, Michela; Jourdain, Roland; Finazzi Agrò, Alessandro; Breton, Lionel; Maccarrone, Mauro

    2012-01-01

    We show that a fully functional endocannabinoid system is present in primary human melanocytes (normal human epidermal melanocyte cells), including anandamide (AEA), 2-arachidonoylglycerol, the respective target receptors (CB1, CB2, and TRPV1), and their metabolic enzymes. We also show that at higher concentrations AEA induces normal human epidermal melanocyte apoptosis (∼3-fold over controls at 5 μm) through a TRPV1-mediated pathway that increases DNA fragmentation and p53 expression. However, at lower concentrations, AEA and other CB1-binding endocannabinoids dose-dependently stimulate melanin synthesis and enhance tyrosinase gene expression and activity (∼3- and ∼2-fold over controls at 1 μm). This CB1-dependent activity was fully abolished by the selective CB1 antagonist SR141716 or by RNA interference of the receptor. CB1 signaling engaged p38 and p42/44 mitogen-activated protein kinases, which in turn activated the cyclic AMP response element-binding protein and the microphthalmia-associated transcription factor. Silencing of tyrosinase or microphthalmia-associated transcription factor further demonstrated the involvement of these proteins in AEA-induced melanogenesis. In addition, CB1 activation did not engage the key regulator of skin pigmentation, cyclic AMP, showing a major difference compared with the regulation of melanogenesis by α-melanocyte-stimulating hormone through melanocortin 1 receptor. PMID:22431736

  17. Identification of Growth Hormone Receptor in Plexiform Neurofibromas of Patients with Neurofibromatosis Type 1

    PubMed Central

    Cunha, Karin Soares Gonçalves; Barboza, Eliane Porto; da Fonseca, Eliene Carvalho

    2008-01-01

    OBJECTIVE The aim of this study was to investigate the presence of growth hormone receptor in plexiform neurofibromas of neurofibromatosis type 1 patients. INTRODUCTION The development of multiple neurofibromas is one of the major features of neurofibromatosis type 1. Since neurofibromas commonly grow during periods of hormonal change, especially during puberty and pregnancy, it has been suggested that hormones may influence neurofibromatosis type 1 neurofibromas. A recent study showed that the majority of localized neurofibromas from neurofibromatosis type 1 patients have growth hormone receptor. METHODS Growth hormone receptor expression was investigated in 5 plexiform neurofibromas using immunohistochemistry. RESULTS Four of the 5 plexiform neurofibromas were immunopositive for growth hormone receptor. CONCLUSION This study suggests that growth hormone may influence the development of plexiform neurofibromas in patients with neurofibromatosis type 1. PMID:18297205

  18. Distribution of angiotensin type-1 receptor messenger RNA expression in the adult rat brain.

    PubMed

    Lenkei, Z; Palkovits, M; Corvol, P; Llorens-Cortes, C

    1998-02-01

    Angiotensin II and angiotensin III in the brain exert their various effects by acting on two pharmacologically well-defined receptors, the type-1 (AT1) and the type-2 (AT2) receptors. Receptor binding autoradiography has revealed the dominant presence of AT1 in brain nuclei involved in cardiovascular, body fluid and neuroendocrine control. The cloning of the AT1 complementary DNA has revealed the existence of two receptor subtypes in rodents, AT1A and AT1B. Using specific riboprobes for in situ hybridization, we have previously shown that the AT1A messenger RNA is predominantly expressed in the rat forebrain; in contrast the AT1B subtype predominates in the anterior pituitary. Using a similar technical approach, the aim of the present study was to establish the precise anatomical localization of cells synthetising the AT1A receptor in the adult rat brain. High AT1A messenger RNA expression was found in the vascular organ of the lamina terminalis, the median preoptic nucleus, the subfornical organ, the hypothalamic periventricular nucleus, the parvocellular parts of the paraventricular nucleus, the nucleus of the solitary tract and the area postrema, in agreement with previous autoradiographic studies, describing a high density of AT1 binding sites in these nuclei. In addition, AT1A messenger RNA expression was detected in several brain areas, where no AT1 binding was reported previously. Thus, we identify strong expression of AT1A messenger RNA expression in scattered cells of the lateral parts of the preoptic region, the lateral hypothalamus and several brainstem nuclei. In none of these structures was the AT1B messenger RNA detectable at the microscopic level. In conclusion, it is suggested that angiotensins may exert their central effects on body fluid and cardiovascular homeostasis mainly via the AT1A receptor subtype. PMID:9483539

  19. Molecular cloning and expression analysis of mannose receptor C type 1 in grass carp (Ctenopharyngodon idella).

    PubMed

    Wang, Li; Liu, Lichun; Zhou, Yang; Zhao, Xiaoheng; Xi, Mingjun; Wei, Shun; Fang, Rui; Ji, Wei; Chen, Nan; Gu, Zemao; Liu, Xueqin; Wang, Weimin; Asim, Muhammad; Liu, Xiaoling; Lin, Li

    2014-03-01

    Mannose receptor C type 1 (MRC1) is a pattern-recognition receptor (PRR) which plays a significant role in immune responses. Much work on MRC1 has been done in mammals and birds while little in fish. In this study, we cloned and characterized MRC1 in grass carp (gcMR). The full-length gcMR contained 5291bp encoding a putative protein of 1432 amino acids. The predicted amino acid sequences showed that gcMR contained a signal peptide, a cysteine-rich (CR) domain, a fibronectin type II (FN II) domain, eight C-type lectin-like domains (CTLDs), a transmembrane domain and a short cytoplasmic domain. gcMR were constitutively expressed in different organs with the higher expression in spleen and head kidney. During embryonic development, gcMR transcript levels were highest at cleavage stage. The up-regulation expression of gcMR, IL-1β and TNF-α in liver, spleen, head kidney and intestine after Aeromonas hydrophila infection indicating it involved in innate immune regulation during bacterial infections. PMID:24184700

  20. POLLUTANT PARTICLES PRODUCE VASOCONSTRICTION AND ENHANCE MAPK SIGNALING VIA ANGIOTENSIN TYPE 1 RECEPTOR

    EPA Science Inventory

    Exposure to particulate matter (PM) is associated with acute cardiovascular mortality and morbidity, but the mechanisms are not entirely clear. In this study, we hypothesized that PM may activate the angiotensin type 1 receptor (AT1R), a G protein-coupled receptor that regulates ...

  1. Pharmacology of the capsaicin receptor, transient receptor potential vanilloid type-1 ion channel.

    PubMed

    Nagy, Istvan; Friston, Dominic; Valente, Jojo Sousa; Torres Perez, Jose Vicente; Andreou, Anna P

    2014-01-01

    The capsaicin receptor, transient receptor potential vanilloid type 1 ion channel (TRPV1), has been identified as a polymodal transducer molecule on a sub-set of primary sensory neurons which responds to various stimuli including noxious heat (> -42 degrees C), protons and vanilloids such as capsaicin, the hot ingredient of chilli peppers. Subsequently, TRPV1 has been found indispensable for the development of burning pain and reflex hyperactivity associated with inflammation of peripheral tissues and viscera, respectively. Therefore, TRPV1 is regarded as a major target for the development of novel agents for the control of pain and visceral hyperreflexia in inflammatory conditions. Initial efforts to introduce agents acting on TRPV1 into clinics have been hampered by unexpected side-effects due to wider than expected expression in various tissues, as well as by the complex pharmacology, of TRPV1. However, it is believed that better understanding of the pharmacological properties of TRPV1 and specific targeting of tissues may eventually lead to the development of clinically useful agents. In order to assist better understanding of TRPV1 pharmacology, here we are giving a comprehensive account on the activation and inactivation mechanisms and the structure-function relationship of TRPV1. PMID:24941664

  2. Astroglial type-1 cannabinoid receptor (CB1): A new player in the tripartite synapse.

    PubMed

    Oliveira da Cruz, J F; Robin, L M; Drago, F; Marsicano, G; Metna-Laurent, M

    2016-05-26

    The endocannabinoid system is an important regulator of physiological functions. In the brain, this control is mainly exerted through the type-1-cannabinoid (CB1) receptors. CB1 receptors are abundant at neuron terminals where their stimulation inhibits neurotransmitter release. However, CB1 receptors are also expressed in astrocytes and recent studies showed that astroglial cannabinoid signaling is a key element of the tripartite synapse. In this review we discuss the different mechanisms by which astroglial CB1 receptors control synaptic transmission and plasticity. The recent involvement of astroglial CB1 receptors in the effects of cannabinoids on memory highlights their key roles in cognitive processes and further indicates that astrocytes are central active elements of high-order brain functions. PMID:25967266

  3. Rising stars: modulation of brain functions by astroglial type-1 cannabinoid receptors.

    PubMed

    Metna-Laurent, Mathilde; Marsicano, Giovanni

    2015-03-01

    The type-1-cannabinoid (CB1 ) receptor is amongst the most widely expressed G protein-coupled receptors in the brain. In few decades, CB1 receptors have been shown to regulate a large array of functions from brain cell development and survival to complex cognitive processes. Understanding the cellular mechanisms underlying these functions of CB1 is complex due to the heterogeneity of the brain cell types on which the receptor is expressed. Although the large majority of CB1 receptors act on neurons, early studies pointed to a direct control of CB1 receptors over astroglial functions including brain energy supply and neuroprotection. In line with the growing concept of the tripartite synapse highlighting astrocytes as direct players in synaptic plasticity, astroglial CB1 receptor signaling recently emerged as the mediator of several forms of synaptic plasticity associated to important cognitive functions. Here, we shortly review the current knowledge on CB1 receptor-mediated astroglial functions. This functional spectrum is large and most of the mechanisms by which CB1 receptors control astrocytes, as well as their consequences in vivo, are still unknown, requiring innovative approaches to improve this new cannabinoid research field. PMID:25452006

  4. Angiotensin II receptor heterogeneity

    SciTech Connect

    Herblin, W.F.; Chiu, A.T.; McCall, D.E.; Ardecky, R.J.; Carini, D.J.; Duncia, J.V.; Pease, L.J.; Wong, P.C.; Wexler, R.R.; Johnson, A.L. )

    1991-04-01

    The possibility of receptor heterogeneity in the angiotensin II (AII) system has been suggested previously, based on differences in Kd values or sensitivity to thiol reagents. One of the authors earliest indications was the frequent observation of incomplete inhibition of the binding of AII to adrenal cortical membranes. Autoradiographic studies demonstrated that all of the labeling of the rat adrenal was blocked by unlabeled AII or saralasin, but not by DuP 753. The predominant receptor in the rat adrenal cortex (80%) is sensitive to dithiothreitol (DTT) and DuP 753, and is designated AII-1. The residual sites in the adrenal cortex and almost all of the sites in the rat adrenal medulla are insensitive to both DTT and DuP 753, but were blocked by EXP655. These sites have been confirmed by ligand binding studies and are designated AII-2. The rabbit adrenal cortex is unique in yielding a nonuniform distribution of AII-2 sites around the outer layer of glomerulosa cells. In the rabbit kidney, the sites on the glomeruli are AII-1, but the sites on the kidney capsule are AII-2. Angiotensin III appears to have a higher affinity for AII-2 sites since it inhibits the binding to the rabbit kidney capsule but not the glomeruli. Elucidation of the distribution and function of these diverse sites should permit the development of more selective and specific therapeutic strategies.

  5. Different Involvement of Type 1, 2, and 3 Ryanodine Receptors in Memory Processes

    ERIC Educational Resources Information Center

    Galeotti, Nicoletta; Quattrone, Alessandro; Vivoli, Elisa; Norcini, Monica; Bartolini, Alessandro; Ghelardini, Carla

    2008-01-01

    The administration of the ryanodine receptor (RyR) agonist 4-Cmc (0.003-9 nmol per mouse intracerebroventricularly [i.c.v.]) ameliorated memory functions, whereas the RyR antagonist ryanodine (0.0001-1 nmol per mouse i.c.v.) induced amnesia in the mouse passive avoidance test. The role of the type 1, 2, and 3 RyR isoforms in memory processes was…

  6. Toll-like receptor 3 gene polymorphisms in South African Blacks with type 1 diabetes.

    PubMed

    Pirie, F J; Pegoraro, R; Motala, A A; Rauff, S; Rom, L; Govender, T; Esterhuizen, T M

    2005-08-01

    Type 1 diabetes is the consequence of exposure of genetically susceptible individuals to specific environmental precipitants. The innate immune system provides the initial response to exogenous antigen and links with the adaptive immune system. The aim of this study was to assess the role of polymorphisms occurring in the cytoplasmic region of toll-like receptor (TLR) 3 gene and immediate 5' sequence, in subjects of Zulu descent with type 1 diabetes in KwaZulu-Natal, South Africa. Seventy-nine subjects with type 1 diabetes and 74 healthy normal glucose tolerant gender-matched control subjects were studied. Parts of exon 4 and exon 3/intron 3 of the TLR3 gene were studied by polymerase chain reaction, direct sequencing and restriction enzyme digestion with Bts 1. Of the nine polymorphisms studied, a significant association with type 1 diabetes was found for the major allele in the 2593 C/T polymorphism and for the minor alleles in the 2642 C/A and 2690 A/G polymorphisms, which were found to be in complete linkage disequilibrium. Correction of the P-values for the number of alleles studied, however, rendered the results no longer significant. These results suggest that polymorphisms in the TLR3 gene, which is part of the innate immune system, may be associated with type 1 diabetes in this population. PMID:16029432

  7. A 5'-upstream short open reading frame encoded peptide regulates angiotensin type 1a receptor production and signalling via the β-arrestin pathway.

    PubMed

    Yosten, Gina L C; Liu, Jun; Ji, Hong; Sandberg, Kathryn; Speth, Robert; Samson, Willis K

    2016-03-15

    AUG sequences and short open reading frames are commonly present in the 5'-leader sequence of G protein-coupled receptor mRNAs. The presence of these upstream AUG sequences has been demonstrated to inhibit downstream receptor translation efficiency and, most recently, receptor signal transduction. A seven amino acid peptide encoded by a short open reading frame in exon 2 of the angiotensin type 1a receptor has been shown to inhibit non-G protein-coupled signalling of angiotensin II, without altering the classical G protein-coupled pathway activated by the ligand. This finding may lead to the development of a new class of angiotensin receptor antagonists with activities biased for one, but not all, of the signalling cascades activated by angiotensin II, which could have therapeutic implications for the myriad hormones and neurotransmitters that signal through G protein-coupled receptors. PMID:26333095

  8. 4.1N binding regions of inositol 1,4,5-trisphosphate receptor type 1.

    PubMed

    Fukatsu, Kazumi; Bannai, Hiroko; Inoue, Takafumi; Mikoshiba, Katsuhiko

    2006-04-01

    Zhang et al. and Maximov et al. [S. Zhang, A. Mizutani, C. Hisatsune, T. Higo, H. Bannai, T. Nakayama, M. Hattori, and K. Mikoshiba, Protein 4.1N is required for translocation of inositol 1,4,5-trisphosphate receptor type 1 to the basolateral membrane domain in polarized Madin-Darby canine kidney cells, J. Biol. Chem. 278 (2003) 4048-4056; A. Maximov, T. S. Tang, and I. Bezprozvanny, Association of the type 1 inositol (1,4,5)-trisphosphate receptor with 4.1N protein in neurons, Mol. Cell. Neurosci. 22 (2003) 271-283.] reported that 4.1N is a binding partner of inositol 1,4,5-trisphosphate receptor type 1 (IP(3)R1), however the binding site of IP(3)R1 differed: the former determined the C-terminal 14 amino acids of the cytoplasmic tail (CTT14aa) as the binding site, while the latter assigned another segment, cytoplasmic tail middle 1 (CTM1). To solve this discrepancy, we performed immunoprecipitation and found that both the segments had binding activity to 4.1N. Both segments also interfered the 4.1N-regulated IP(3)R1 diffusion in neuronal dendrites. However, IP(3)R1 lacking the CTT14aa (IP(3)R1-DeltaCTT14aa) does not bind to 4.1N [S. Zhang, A. Mizutani, C. Hisatsune, T. Higo, H. Bannai, T. Nakayama, M. Hattori, and K. Mikoshiba, Protein 4.1N is required for translocation of inositol 1,4,5-trisphosphate receptor type 1 to the basolateral membrane domain in polarized Madin-Darby canine kidney cells, J. Biol. Chem. 278 (2003) 4048-4056.] and its diffusion constant is larger than that of IP(3)R1 full-length in neuronal dendrites [K. Fukatsu, H. Bannai, S. Zhang, H. Nakamura, T. Inoue, and K. Mikoshiba, Lateral diffusion of inositol 1,4,5-trisphosphate receptor type 1 is regulated by actin filaments and 4.1N in neuronal dendrites, J. Biol. Chem. 279 (2004) 48976-48982.]. We conclude that both the CTT14aa and CTM1 sequences can bind to 4.1N in peptide fragment forms. However, we propose that the responsible binding site for 4.1N binding in full-length tetramer form of IP

  9. The Connections Between the UV and Optical Fe ii Emission Lines in Type 1 AGNs

    NASA Astrophysics Data System (ADS)

    Kovačević-Dojčinović, Jelena; Popović, Luka Č.

    2015-12-01

    We investigate the spectral properties of the UV (λλ2650-3050 Å) and optical (λλ4000-5500 Å) Fe ii emission features in a sample of 293 Type 1 active galactic nuclei (AGNs) from the Sloan Digital Sky Survey database. We explore different correlations between their emission line properties, as well as the correlations with other emission lines from the spectral range. We find several interesting correlations and outline the most interesting results as follows. (i) There is a kinematical connection between the UV and optical Fe ii lines, indicating that the UV and optical Fe ii lines originate from the outer part of the broad line region, the so-called intermediate line region. (ii) The unexplained anticorrelations of the optical Fe ii equivalent width (EW Fe iiopt) versus EW [O iii] 5007 Å and EW Fe iiopt versus FWHM Hβ have not been detected for the UV Fe ii lines. (iii) The significant averaged redshift in the UV Fe ii lines, which is not present in optical Fe ii, indicates an inflow in the UV Fe ii emitting clouds, and probably their asymmetric distribution. (iv) Also, we confirm the anticorrelation between the intensity ratio of the optical and UV Fe ii lines and the FWHM of Hβ, and we find the anticorrelations of this ratio with the widths of Mg ii 2800 Å, optical Fe ii, and UV Fe ii. This indicates a very important role for the column density and microturbulence in the emitting gas. We discuss the starburst activity in high-density regions of young AGNs as a possible explanation of the detected optical Fe ii correlations and intensity line ratios of the UV and optical Fe ii lines.

  10. Inhibition of topoisomerase II by ICRF-193 prevents efficient replication of herpes simplex virus type 1.

    PubMed Central

    Hammarsten, O; Yao, X; Elias, P

    1996-01-01

    Cellular topoisomerase II is specifically inactivated by the drug ICRF-193. This compound turns topoisomerase II into a closed clamp that is unable to cleave DNA. We have investigated the effects of this inhibitor on the replication of herpes simplex virus type 1. We show that ICRF-193 at low multiplicities of infection dramatically inhibits viral DNA synthesis and the production of infectious virus. The inhibition is less efficient at high multiplicities of infection. In addition, inhibition of viral DNA synthesis was observed only when ICRF-193 was present during the first 4 h of the infectious cycle. The transient replication of plasmids containing a herpes simplex virus type 1 origin of DNA replication, oriS, was affected by ICRF-193 in the same way. In contrast, neither cellular DNA synthesis nor replication of plasmids containing a simian virus 40 origin of DNA replication was inhibited. The observed effect on herpes simplex virus DNA replication was not caused by a decreased transcription of replication genes inasmuch as the levels of UL8, UL9, UL29, and UL30 rmRNAs were unaffected by the drug. These results suggest that topoisomerase II plays a vital role during the replication of herpes simplex virus type 1 DNA. We speculate that topoisomerase II is involved in the decatenation of newly synthesized daughter molecules. PMID:8676478

  11. Cannabinoids mediate analgesia largely via peripheral type 1 cannabinoid receptors in nociceptors

    PubMed Central

    Agarwal, Nitin; Pacher, Pal; Tegeder, Irmgard; Amaya, Fumimasa; Constantin, Cristina E; Brenner, Gary J; Rubino, Tiziana; Michalski, Christoph W; Marsicano, Giovanni; Monory, Krisztina; Mackie, Ken; Marian, Claudiu; Batkai, Sandor; Parolaro, Daniela; Fischer, Michael J; Reeh, Peter; Kunos, George; Kress, Michaela; Lutz, Beat; Woolf, Clifford J; Kuner, Rohini

    2008-01-01

    Although endocannabinoids constitute one of the first lines of defense against pain, the anatomical locus and the precise receptor mechanisms underlying cannabinergic modulation of pain are uncertain. Clinical exploitation of the system is severely hindered by the cognitive deficits, memory impairment, motor disturbances and psychotropic effects resulting from the central actions of cannabinoids. We deleted the type 1 cannabinoid receptor (CB1) specifically in nociceptive neurons localized in the peripheral nervous system of mice, preserving its expression in the CNS, and analyzed these genetically modified mice in preclinical models of inflammatory and neuropathic pain. The nociceptor-specific loss of CB1 substantially reduced the analgesia produced by local and systemic, but not intrathecal, delivery of cannabinoids. We conclude that the contribution of CB1-type receptors expressed on the peripheral terminals of nociceptors to cannabinoid-induced analgesia is paramount, which should enable the development of peripherally acting CB1 analgesic agonists without any central side effects. PMID:17558404

  12. Rectification of muscle and nerve deficits in paralyzed ryanodine receptor type 1 mutant embryos

    PubMed Central

    Hanson, M. Gartz; Niswander, Lee A.

    2015-01-01

    Locomotion and respiration require motor axon connectivity and activation of the neuromuscular junction (NMJ). Through a forward genetic screen for muscle weakness, we recently reported an allele of ryanodine receptor type 1 (Ryr1AG). Here we reveal a role for functional RyR1 during acetylcholine receptor (AChR) cluster formation and embryonic synaptic transmission. Ryr1AG homozygous embryos are non-motile. Motor axons extend past AChR clusters and enlarged AChR clusters are found under fasciculated nerves. Using physiological and pharmacological methods, we show that contractility can be resumed through the masking of a potassium leak, and evoked vesicular release can be resumed via bypassing the defect in RyR1 induced calcium release. Moreover, we show the involvement of ryanodine receptors in presynaptic release at the NMJ. This data provides evidence of a role for RyR1 on both the pre- and postsynaptic sides of the NMJ. PMID:26025922

  13. Discovery of selective hexapeptide agonists to human neuromedin U receptors types 1 and 2.

    PubMed

    Takayama, Kentaro; Mori, Kenji; Taketa, Koji; Taguchi, Akihiro; Yakushiji, Fumika; Minamino, Naoto; Miyazato, Mikiya; Kangawa, Kenji; Hayashi, Yoshio

    2014-08-14

    Neuromedin U (NMU) are bioactive peptides with a common C-terminal heptapeptide sequence (FLFRPRN-amide, 1a) among mammals, which is responsible for receptor activation, namely NMU receptor types 1 (NMUR1) and 2 (NMUR2). Among the various physiological actions of NMU, the anorexigenic effect has recently attracted attention in drug discovery efforts for treating obesity. Although several structure-activity relationship (SAR) studies have been reported, receptor-selective small peptide agonists have yet to be disclosed. Herein a SAR study of 1a-derived peptide derivatives is described. We initially screened both human NMUR1- and NMUR2-selective peptides in calcium-mobilization assays with cells transiently expressing receptors. Then we performed a precise assay with a stable expression system of receptors and consequently discovered hexapeptides 8d and 6b possessing selective agonist activity toward each respective receptor. Hexapeptide 6b, which selectively activates NMUR2 without significant NMUR1 activation, should aid in the development of anorexigenic drugs as well as advance NMU-related endocrinological research. PMID:24999562

  14. THE PREVALENCE OF NARROW OPTICAL Fe II EMISSION LINES IN TYPE 1 ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Dong Xiaobo; Wang Jianguo; Wang Tinggui; Wang Huiyuan; Zhou Hongyan; Ho, Luis C.; Fan Xiaohui

    2010-10-01

    From detailed spectral analysis of a large sample of low-redshift active galactic nuclei (AGNs) selected from the Sloan Digital Sky Survey, we demonstrate-statistically for the first time-that narrow optical Fe II emission lines, both permitted and forbidden, are prevalent in type 1 AGNs. Remarkably, these optical lines are completely absent in type 2 AGNs, across a wide luminosity range, from Seyfert 2 galaxies to type 2 quasars. We suggest that the narrow Fe II-emitting gas is confined to a disk-like geometry in the innermost regions of the narrow-line region on physical scales smaller than the obscuring torus.

  15. NO EVIDENCE FOR A SYSTEMATIC Fe II EMISSION LINE REDSHIFT IN TYPE 1 ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Sulentic, Jack W.; Marziani, Paola; Zamfir, Sebastian; Meadows, Zachary A. E-mail: paola.marziani@oapd.inaf.it E-mail: Zachary.A.Meadows@uwsp.edu

    2012-06-10

    We test the recent claim by Hu et al. that Fe II emission in type 1 active galactic nuclei shows a systematic redshift relative to the local source rest frame and broad-line H{beta}. We compile high signal-to-noise median composites using Sloan Digital Sky Survey spectra from both the Hu et al. sample and our own sample of the 469 brightest DR5 spectra. Our composites are generated in bins of FWHM H{beta} and Fe II strength as defined in our 4D Eigenvector 1 formalism. We find no evidence for a systematic Fe II redshift and consistency with previous assumptions that Fe II shift and width (FWHM) follow H{beta} shift and FWHM in virtually all sources. This result is consistent with the hypothesis that Fe II emission (quasi-ubiquitous in type 1 sources) arises from a broad-line region with geometry and kinematics the same as that producing the Balmer lines.

  16. Repression of host RNA polymerase II transcription by herpes simplex virus type 1.

    PubMed Central

    Spencer, C A; Dahmus, M E; Rice, S A

    1997-01-01

    Lytic infection of mammalian cells with herpes simplex virus type 1 (HSV-1) results in rapid repression of host gene expression and selective activation of the viral genome. This transformation in gene expression is thought to involve repression of host transcription and diversion of the host RNA polymerase (RNAP II) transcription machinery to the viral genome. However, the extent of virus-induced host transcription repression and the mechanisms responsible for these major shifts in transcription specificities have not been examined. To determine how HSV-1 accomplishes repression of host RNAP II transcription, we assayed transcription patterns on several cellular genes in cells infected with mutant and wild-type HSV-1. Our results suggest that HSV-1 represses RNAP II transcription on most cellular genes. However, each cellular gene we examined responds differently to the transcription repressive effects of virus infection, both quantitatively and with respect to the involvement of viral gene products. Virus-induced shutoff of host RNAP II transcription requires expression of multiple immediate-early genes. In contrast, expression of delayed-early and late genes and viral DNA replication appear to contribute little to repression of host cell RNAP II transcription. Modification of RNAP II to the intermediately phosphorylated (II(I)) form appears unlinked to virus-induced repression of host cell transcription. However, full repression of host transcription is correlated with depletion of the hyperphosphorylated (IIO) form of RNAP II. PMID:9032335

  17. Cannabinoid type-1 receptor signaling in central serotonergic neurons regulates anxiety-like behavior and sociability

    PubMed Central

    Häring, Martin; Enk, Vanessa; Aparisi Rey, Alejandro; Loch, Sebastian; Ruiz de Azua, Inigo; Weber, Tillmann; Bartsch, Dusan; Monory, Krisztina; Lutz, Beat

    2015-01-01

    The endocannabinoid (eCB) system possesses neuromodulatory functions by influencing the release of various neurotransmitters, including γ-aminobutyric acid (GABA) and glutamate. A functional interaction between eCBs and the serotonergic system has already been suggested. Previously, we showed that cannabinoid type-1 (CB1) receptor mRNA and protein are localized in serotonergic neurons of the raphe nuclei, implying that the eCB system can modulate serotonergic functions. In order to substantiate the physiological role of the CB1 receptor in serotonergic neurons of the raphe nuclei, we generated serotonergic 5-hydroxytryptamine (5-HT) neuron-specific CB1 receptor-deficient mice, using the Cre/loxP system with a tamoxifen-inducible Cre recombinase under the control of the regulatory sequences of the tryptophan hydroxylase 2 gene (TPH2-CreERT2), thus, restricting the recombination to 5-HT neurons of the central nervous system (CNS). Applying several different behavioral paradigms, we revealed that mice lacking the CB1 receptor in serotonergic neurons are more anxious and less sociable than control littermates. Thus, we were able to show that functional CB1 receptor signaling in central serotonergic neurons modulates distinct behaviors in mice. PMID:26388750

  18. Mood stabilizer treatment increases serotonin type 1A receptor binding in bipolar depression

    PubMed Central

    Nugent, Allison C; Carlson, Paul J; Bain, Earle E; Eckelman, William; Herscovitch, Peter; Manji, Husseini; Zarate, Carlos A; Drevets, Wayne C

    2013-01-01

    Abnormal serotonin type 1A (5-HT1A) receptor function and binding have been implicated in the pathophysiology of mood disorders. Preclinical studies have consistently shown that stress decreases the gene expression of 5-HT1A receptors in experimental animals, and that the associated increase in hormone secretion plays a crucial role in mediating this effect. Chronic administration of the mood stabilizers lithium and divalproex (valproate semisodium) reduces glucocorticoid signaling and function in the hippocampus. Lithium has further been shown to enhance 5-HT1A receptor function. To assess whether these effects translate to human subject with bipolar disorder (BD), positron emission tomography (PET) and [18F]trans-4-fluoro-N-(2-[4-(2-methoxyphenyl) piperazino]-ethyl)-N-(2-pyridyl) cyclohexanecarboxamide ([18F]FCWAY) were used to acquire PET images of 5-HT1A receptor binding in 10 subjects with BD, before and after treatment with lithium or divalproex. Mean 5-HT1A binding potential (BPP) significantly increased following mood stabilizer treatment, most prominently in the mesiotemporal cortex (hippocampus plus amygdala). When mood state was also controlled for, treatment was associated with increases in BPP in widespread cortical areas. These preliminary findings are consistent with the hypothesis that these mood stabilizers enhance 5-HT1A receptor expression in BD, which may underscore an important component of these agents' mechanism of action. PMID:23926239

  19. Deficiency of angiotensin type 1a receptors in adipocytes reduces differentiation and promotes hypertrophy of adipocytes in lean mice.

    PubMed

    Putnam, Kelly; Batifoulier-Yiannikouris, Frederique; Bharadwaj, Kalyani G; Lewis, Eboni; Karounos, Michael; Daugherty, Alan; Cassis, Lisa A

    2012-10-01

    Adipocytes express angiotensin receptors, but the direct effects of angiotensin II (AngII) stimulating this cell type are undefined. Adipocytes express angiotensin type 1a receptor (AT1aR) and AT2R, both of which have been implicated in obesity. In this study, we determined the effects of adipocyte AT1aR deficiency on adipocyte differentiation and the development of obesity in mice fed low-fat (LF) or high-fat (HF) diets. Mice expressing Cre recombinase under the control of the aP2 promoter were bred with AT1aR-floxed mice to generate mice with adipocyte AT1aR deficiency (AT1aR(aP2)). AT1aR mRNA abundance was reduced significantly in both white and brown adipose tissue from AT1aR(aP2) mice compared with nontransgenic littermates (AT1aR(fl/fl)). Adipocyte AT1aR deficiency did not influence body weight, glucose tolerance, or blood pressure in mice fed either LF or high-fat diets. However, LF-fed AT1aR(aP2) mice exhibited striking adipocyte hypertrophy even though total fat mass was not different between genotypes. Stromal vascular cells from AT1aR(aP2) mice differentiated to a lesser extent to adipocytes compared with controls. Conversely, incubation of 3T3-L1 adipocytes with AngII increased Oil Red O staining and increased mRNA abundance of peroxisome proliferator-activated receptor γ (PPARγ) via AT1R stimulation. These results suggest that reductions in adipocyte differentiation in LF-fed AT1aR(aP2) mice resulted in increased lipid storage and hypertrophy of remaining adipocytes. These results demonstrate that AngII regulates adipocyte differentiation and morphology through the adipocyte AT1aR in lean mice. PMID:22919058

  20. The type 1 lysophosphatidic acid receptor is a target for therapy in bone metastases

    PubMed Central

    Boucharaba, Ahmed; Serre, Claire-Marie; Guglielmi, Julien; Bordet, Jean-Claude; Clézardin, Philippe; Peyruchaud, Olivier

    2006-01-01

    Platelet-derived lysophosphatidic acid (LPA) supports the progression of breast and ovarian cancer metastasis to bone. The mechanisms through which LPA promotes bone metastasis formation are, however, unknown. Here we report that silencing of the type 1 LPA receptor (LPA1) in cancer cells blocks the production of tumor-derived cytokines that are potent activators of osteoclast-mediated bone destruction and significantly reduces the progression of osteolytic bone metastases. Moreover, functional blockade of LPA action on its cognate receptor LPA1 using a pharmacological antagonist mimics the effects of silencing LPA1 in tumor cells in vitro and substantially reduces bone metastasis progression in animals. Overall, these results suggest that inhibition of platelet-derived LPA action on LPA1 expressed by tumor cells may be a promising therapeutic target for patients with bone metastases. PMID:16769891

  1. Modulation of defensive behavior by Transient Receptor Potential Vanilloid Type-1 (TRPV1) channels.

    PubMed

    Aguiar, D C; Moreira, F A; Terzian, A L; Fogaça, M V; Lisboa, S F; Wotjak, C T; Guimaraes, F S

    2014-10-01

    The Transient Receptor Potential Vanilloid Type-1 (TRPV1) was first characterized in primary afferent fibers as a receptor for capsaicin (the pungent ingredient of chili peppers). Later on, this cation-permeable ion channel was also described in the central nervous system, where its main putative endogenous ligand is N-arachidonoyl ethanolamide (an endocannabinoid, also known as anandamide). Recent results employing genetic, pharmacological and histochemical techniques indicate that TRPV1 tonically modulate anxiety, fear and panic responses in brain regions related to defensive responses, such as the dorsal periaqueductal gray, the hippocampus and the medial prefrontal cortex. Genetic deletion or antagonism of this ion channel induces anxiolytic-like effects in several animal models. The main mechanism responsible for TRPV1-mediated effects on anxiety seems to involve facilitation of glutamatergic neurotransmission. In addition, there is evidence for interactions with other neurotransmitter systems, such as nitric oxide and endocannabinoids. PMID:24726577

  2. Aldosterone-Induced Vascular Remodeling and Endothelial Dysfunction Require Functional Angiotensin Type 1a Receptors.

    PubMed

    Briet, Marie; Barhoumi, Tlili; Mian, Muhammad Oneeb Rehman; Coelho, Suellen C; Ouerd, Sofiane; Rautureau, Yohann; Coffman, Thomas M; Paradis, Pierre; Schiffrin, Ernesto L

    2016-05-01

    We investigated the role of angiotensin type 1a receptors (AGTR1a) in vascular injury induced by aldosterone activation of mineralocorticoid receptors in Agtr1a(-/-) and wild-type (WT) mice infused with aldosterone for 14 days while receiving 1% NaCl in drinking water. Aldosterone increased systolic blood pressure (BP) by ≈30 mm Hg in WT mice and ≈50 mm Hg in Agtr1a(-/-) mice. Aldosterone induced aortic and small artery remodeling, impaired endothelium-dependent relaxation in WT mice, and enhanced fibronectin and collagen deposition and vascular inflammation. None of these vascular effects were observed in Agtr1a(-/-) mice. Aldosterone effects were prevented by the AGTR1 antagonist losartan in WT mice. In contrast to aldosterone, norepinephrine caused similar BP increase and mesenteric artery remodeling in WT and Agtr1a(-/-) mice. Agtr1a(-/-) mice infused with aldosterone did not increase sodium excretion in response to a sodium chloride challenge, suggesting that sodium retention could contribute to the exaggerated BP rise induced by aldosterone. Agtr1a(-/-) mice had decreased mesenteric artery expression of the calcium-activated potassium channel Kcnmb1, which may enhance myogenic tone and together with sodium retention, exacerbate BP responses to aldosterone/salt in Agtr1a(-/-) mice. We conclude that although aldosterone activation of mineralocorticoid receptors raises BP more in Agtr1a(-/-) mice, AGTR1a is required for mineralocorticoid receptor stimulation to induce vascular remodeling and inflammation and endothelial dysfunction. PMID:27045029

  3. Modulation of TGF-beta type 1 receptor: flow cytometric detection with biotinylated TGF-beta.

    PubMed

    Newman, W; Beall, L D; Bertolini, D R; Cone, J L

    1989-10-01

    Transforming growth factor beta type 1 (TGF-beta 1) was reacted with NHS-biotin to yield a derivative of TGF-beta 1 which was biotinylated on lysine residues. The biotinylated form of TGF-beta 1 was separated from the unreacted material by reverse phase chromatography. In three separate bioassays, the derivatized peptide was as active as the starting material. The use of FITC-avidin in conjunction with flow cytometry demonstrated that the binding of biotinylated TGF-beta 1 to its receptor is saturable, competable, and specific. A 100-fold molar excess of underivatized TGF-beta 1 gave 85% inhibition of binding of the biotinylated peptide to the mink lung cell line CCL-64, while TGF-beta 2 showed no inhibition of binding, nor did insulin, calcitonin, or TGF-alpha. Both CCL-64 cells and human umbilical vein endothelial cells showed a density-dependent down-regulation of receptor expression in culture. Several factors were examined that might mediate this effect. The down-regulation was shown not to be due to the secretion of an active form of TGF-beta 1. The extracellular matrix from high-density cells did not decrease expression of the receptor. Fibronectin, collagen, and gelatin were also unable to signal changes in receptor expression, even though in other systems such matrix components can regulate the responsiveness of cells to TGF-beta 1. Lastly, staining simultaneously for DNA content and TGF-beta 1 receptor expression showed that there was no correlation between cell cycle and receptor levels. PMID:2550480

  4. Ca(2+) microdomains, NAADP and type 1 ryanodine receptor in cell activation.

    PubMed

    Guse, Andreas H; Wolf, Insa M A

    2016-06-01

    Nicotinic acid adenine dinucleotide phosphate (NAADP) is a Ca(2+) mobilizing second messenger that belongs to the superfamily of regulatory adenine nucleotides. Though NAADP has been known since 20years, several aspects of its metabolism and molecular mode of action are still under discussion. Though the importance of the type 1 ryanodine receptor was discovered and published already in 2002 Hohenegger et al. (2002 Oct 15) , recent data re-emphasize these original findings in pancreatic acinar cells and in T-lymphocytes. Here we review recent developments in NAADP formation and metabolism, putative target Ca(2+) channels for NAADP with special emphasis on the type 1 ryanodine receptor, and NAADP binding proteins. The latter are basis for a unifying hypothesis for NAADP action. Finally, the role of NAADP in T cell Ca(2+) signaling and activation is discussed. This article is part of a Special Issue entitled: Calcium and Cell Fate . Guest Editors: Jacques Haiech, Claus Heizmann, Joachim Krebs, Thierry Capiod and Olivier Mignen. PMID:26804481

  5. Cannabinoid type 1 receptor availability in the amygdala mediates threat processing in trauma survivors.

    PubMed

    Pietrzak, Robert H; Huang, Yiyun; Corsi-Travali, Stefani; Zheng, Ming-Qiang; Lin, Shu-fei; Henry, Shannan; Potenza, Marc N; Piomelli, Daniele; Carson, Richard E; Neumeister, Alexander

    2014-10-01

    Attentional bias to threat is a key endophenotype that contributes to the chronicity of trauma-related psychopathology. However, little is known about the neurobiology of this endophenotype and no known in vivo molecular imaging study has been conducted to evaluate candidate receptor systems that may be implicated in this endophenotype or the phenotypic expression of trauma-related psychopathology that comprises threat (ie, re-experiencing, avoidance, and hyperarousal) and loss (ie, emotional numbing, depression/dysphoria, generalized anxiety) symptomatology. Using the radioligand [(11)C]OMAR and positron emission tomography (PET), we evaluated the relationship between in vivo cannabinoid receptor type 1 (CB1) receptor availability in the amygdala, and performance on a dot-probe measure of attentional bias to threat, and clinician interview-based measures of trauma-related psychopathology. The sample comprised adults presenting with a broad spectrum of trauma-related psychopathology, ranging from nontrauma-exposed, psychiatrically healthy adults to trauma-exposed adults with severe trauma-related psychopathology. Results revealed that increased CB1 receptor availability in the amygdala was associated with increased attentional bias to threat, as well as increased severity of threat, but not loss, symptomatology; greater peripheral anandamide levels were associated with decreased attentional bias to threat. A mediation analysis further suggested that attentional bias to threat mediated the relationship between CB1 receptor availability in the amygdala and severity of threat symptomatology. These data substantiate a key role for compromised endocannabinoid function in mediating both the endophenotypic and phenotypic expression of threat symptomatology in humans. They further suggest that novel pharmacotherapies that target the CB1 system may provide a more focused, mechanism-based approach to mitigating this core aspect of trauma-related psychopathology. PMID

  6. Cannabinoid Type 1 Receptor Availability in the Amygdala Mediates Threat Processing in Trauma Survivors

    PubMed Central

    Pietrzak, Robert H; Huang, Yiyun; Corsi-Travali, Stefani; Zheng, Ming-Qiang; Lin, Shu-fei; Henry, Shannan; Potenza, Marc N; Piomelli, Daniele; Carson, Richard E; Neumeister, Alexander

    2014-01-01

    Attentional bias to threat is a key endophenotype that contributes to the chronicity of trauma-related psychopathology. However, little is known about the neurobiology of this endophenotype and no known in vivo molecular imaging study has been conducted to evaluate candidate receptor systems that may be implicated in this endophenotype or the phenotypic expression of trauma-related psychopathology that comprises threat (ie, re-experiencing, avoidance, and hyperarousal) and loss (ie, emotional numbing, depression/dysphoria, generalized anxiety) symptomatology. Using the radioligand [11C]OMAR and positron emission tomography (PET), we evaluated the relationship between in vivo cannabinoid receptor type 1 (CB1) receptor availability in the amygdala, and performance on a dot-probe measure of attentional bias to threat, and clinician interview-based measures of trauma-related psychopathology. The sample comprised adults presenting with a broad spectrum of trauma-related psychopathology, ranging from nontrauma-exposed, psychiatrically healthy adults to trauma-exposed adults with severe trauma-related psychopathology. Results revealed that increased CB1 receptor availability in the amygdala was associated with increased attentional bias to threat, as well as increased severity of threat, but not loss, symptomatology; greater peripheral anandamide levels were associated with decreased attentional bias to threat. A mediation analysis further suggested that attentional bias to threat mediated the relationship between CB1 receptor availability in the amygdala and severity of threat symptomatology. These data substantiate a key role for compromised endocannabinoid function in mediating both the endophenotypic and phenotypic expression of threat symptomatology in humans. They further suggest that novel pharmacotherapies that target the CB1 system may provide a more focused, mechanism-based approach to mitigating this core aspect of trauma-related psychopathology. PMID:24820537

  7. Activation of Lysophosphatidic Acid Receptor Type 1 Contributes to Pathophysiology of Spinal Cord Injury

    PubMed Central

    Santos-Nogueira, Eva; López-Serrano, Clara; Hernández, Joaquim; Lago, Natalia; Astudillo, Alma M.; Balsinde, Jesús; Estivill-Torrús, Guillermo; de Fonseca, Fernando Rodriguez; Chun, Jerold

    2015-01-01

    Lysophosphatidic acid (LPA) is an extracellular lipid mediator involved in many physiological functions that signals through six known G-protein-coupled receptors (LPA1–LPA6). A wide range of LPA effects have been identified in the CNS, including neural progenitor cell physiology, astrocyte and microglia activation, neuronal cell death, axonal retraction, and development of neuropathic pain. However, little is known about the involvement of LPA in CNS pathologies. Herein, we demonstrate for the first time that LPA signaling via LPA1 contributes to secondary damage after spinal cord injury. LPA levels increase in the contused spinal cord parenchyma during the first 14 d. To model this potential contribution of LPA in the spinal cord, we injected LPA into the normal spinal cord, revealing that LPA induces microglia/macrophage activation and demyelination. Use of a selective LPA1 antagonist or mice lacking LPA1 linked receptor-mediated signaling to demyelination, which was in part mediated by microglia. Finally, we demonstrate that selective blockade of LPA1 after spinal cord injury results in reduced demyelination and improvement in locomotor recovery. Overall, these results support LPA–LPA1 signaling as a novel pathway that contributes to secondary damage after spinal cord contusion in mice and suggest that LPA1 antagonism might be useful for the treatment of acute spinal cord injury. SIGNIFICANCE STATEMENT This study reveals that LPA signaling via LPA receptor type 1 activation causes demyelination and functional deficits after spinal cord injury. PMID:26180199

  8. Receptor for Advanced Glycation End Products (RAGE) in Type 1 Diabetes Pathogenesis.

    PubMed

    Leung, Sherman S; Forbes, Josephine M; Borg, Danielle J

    2016-10-01

    The receptor for advanced glycation end products (RAGE) is a novel protein increasingly studied in the pathogenesis of type 1 diabetes (T1D). RAGE is expressed by several immune cell types, including T cells, antigen-presenting cells, endothelial cells, and the endocrine cells of the pancreatic islets. RAGE binds various ligands including advanced glycation end products (AGEs), high-mobility group box protein 1 (HMGB1), S100 proteins, β-amyloid, β-sheet fibrils, and lipopolysaccharide. AGEs are a particularly interesting ligand because their exogenous introduction into the body can be accelerated by the consumption of AGE-rich processed foods. This review will detail RAGE isoforms and its ligands and discuss how RAGE binding on the aforementioned cells could be linked to T1D pathogenesis. PMID:27612847

  9. Estrogens and Spermiogenesis: New Insights from Type 1 Cannabinoid Receptor Knockout Mice

    PubMed Central

    Cacciola, Giovanna; Chioccarelli, Teresa; Fasano, Silvia; Pierantoni, Riccardo; Cobellis, Gilda

    2013-01-01

    Spermatogenesis is a complex mechanism which allows the production of male gametes; it consists of mitotic, meiotic, and differentiation phases. Spermiogenesis is the terminal differentiation process during which haploid round spermatids undergo several biochemical and morphological changes, including extensive remodelling of chromatin and nuclear shape. Spermiogenesis is under control of endocrine, paracrine, and autocrine factors, like gonadotropins and testosterone. More recently, emerging pieces of evidence are suggesting that, among these factors, estrogens may have a role. To date, this is a matter of debate and concern because of the agonistic and antagonistic estrogenic effects that environmental chemicals may have on animal and human with damaging outcome on fertility. In this review, we summarize data which fuel this debate, with a particular attention to our recent results, obtained using type 1 cannabinoid receptor knockout male mice as animal model. PMID:24324492

  10. Evidence for the transport of glutathione through ryanodine receptor channel type 1.

    PubMed Central

    Bánhegyi, Gábor; Csala, Miklós; Nagy, Gábor; Sorrentino, Vincenzo; Fulceri, Rosella; Benedetti, Angelo

    2003-01-01

    In the present study, we have investigated the role of RyR1 (ryanodine receptor calcium channel type 1) in glutathione (GSH) transport through the sarcoplasmic reticulum (SR) membrane of skeletal muscles. Lanthanum chloride, a prototypic blocker of cation channels, inhibited the influx and efflux of GSH in SR vesicles. Using a rapid-filtration-based assay and lanthanum chloride as a transport blocker, an uptake of radiolabelled GSH into SR vesicles was observed. Pretreatment of SR vesicles with the RyR1 antagonists Ruthenium Red and ryanodine as well as with lanthanum chloride blocked the GSH uptake. An SR-like GSH uptake appeared in microsomes obtained from an HEK-293 (human embryonic kidney 293) cell line after transfection of RyR1. These observations strongly suggest that RyR1 mediates GSH transport through the SR membranes of skeletal muscles. PMID:14519101

  11. Angiotensin II receptors in testes

    SciTech Connect

    Millan, M.A.; Aguilera, G.

    1988-05-01

    Receptors for angiotensin II (AII) were identified and characterized in testes of rats and several primate species. Autoradiographic analysis of the binding of 125I-labeled (Sar1,Ile8)AII to rat, rhesus monkey, cebus monkey, and human testicular slide-mounted frozen sections indicated specific binding to Leydig cells in the interstitium. In rat collagenase-dispersed interstitial cells fractionated by Percoll gradient, AII receptor content was parallel to that of hCG receptors, confirming that the AII receptors are in the Leydig cells. In rat dispersed Leydig cells, binding was specific for AII and its analogs and of high affinity (Kd, 4.8 nM), with a receptor concentration of 15 fmol/10(6) cells. Studies of AII receptors in rat testes during development reveals the presence of high receptor density in newborn rats which decreases toward the adult age (4934 +/- 309, 1460 +/- 228, 772 +/- 169, and 82 +/- 12 fmol/mg protein at 5, 15, 20, and 30 days of age, respectively) with no change in affinity. At all ages receptors were located in the interstitium, and the decrease in binding was parallel to the decrease in the interstitial to tubular ratio observed with age. AII receptor properties in membrane-rich fractions from prepuberal testes were similar in the rat and rhesus monkey. Binding was time and temperature dependent, reaching a plateau at 60 min at 37 C, and was increased by divalent cations, EGTA, and dithiothreitol up to 0.5 mM. In membranes from prepuberal monkey testes, AII receptors were specific for AII analogs and of high affinity (Kd, 4.2 nM) with a receptor concentration of 7599 +/- 1342 fmol/mg protein. The presence of AII receptors in Leydig cells in rat and primate testes in conjunction with reports of the presence of other components of the renin-angiotensin system in the testes suggests that the peptide has a physiological role in testicular function.

  12. Upregulation of Cannabinoid Type 1 Receptors in Dopamine D2 Receptor Knockout Mice Is Reversed by Chronic Forced Ethanol Consumption

    SciTech Connect

    Thanos, P.K.; Wang, G.; Thanos, P.K.; Gopez, V.; Delis, F.; Michaelides, M.; Grand, D.K.; Wang, G.-J.; Kunos, G.; Volkow, N.D.

    2011-01-01

    The anatomical proximity of the cannabinoid type 1 (CNR1/CB1R) and the dopamine D2 receptors (DRD2), their ability to form CB1R-DRD2 heteromers, their opposing roles in locomotion, and their involvement in ethanol's reinforcing and addictive properties prompted us to study the levels and distribution of CB1R after chronic ethanol intake, in the presence and absence of DRD2. We monitored the drinking patterns and locomotor activity of Drd2+/+ and Drd2-/- mice consuming either water or a 20% (v/v) ethanol solution (forced ethanol intake) for 6 months and used the selective CB1 receptor antagonist [{sup 3}H]SR141716A to quantify CB1R levels in different brain regions with in vitro receptor autoradiography. We found that the lack of DRD2 leads to a marked upregulation (approximately 2-fold increase) of CB1R in the cerebral cortex, the caudate-putamen, and the nucleus accumbens, which was reversed by chronic ethanol intake. The results suggest that DRD2-mediated dopaminergic neurotransmission and chronic ethanol intake exert an inhibitory effect on cannabinoid receptor expression in cortical and striatal regions implicated in the reinforcing and addictive properties of ethanol.

  13. Statins Increase Plasminogen Activator Inhibitor Type 1 Gene Transcription through a Pregnane X Receptor Regulated Element

    PubMed Central

    Stanley, Frederick M.; Linder, Kathryn M.; Cardozo, Timothy J.

    2015-01-01

    Plasminogen activator inhibitor type 1 (PAI-1) is a multifunctional protein that has important roles in inflammation and wound healing. Its aberrant regulation may contribute to many disease processes such as heart disease. The PAI-1 promoter is responsive to multiple inputs including cytokines, growth factors, steroids and oxidative stress. The statin drugs, atorvastatin, mevastatin and rosuvastatin, increased basal and stimulated expression of the PAI-1 promoter 3-fold. A statin-responsive, nuclear hormone response element was previously identified in the PAI-1 promoter, but it was incompletely characterized. We characterized this direct repeat (DR) of AGGTCA with a 3-nucleotide spacer at -269/-255 using deletion and directed mutagenesis. Deletion or mutation of this element increased basal transcription from the promoter suggesting that it repressed PAI-1 transcription in the unliganded state. The half-site spacing and the ligand specificity suggested that this might be a pregnane X receptor (PXR) responsive element. Computational molecular docking showed that atorvastatin, mevastatin and rosuvastatin were structurally compatible with the PXR ligand-binding pocket in its agonist conformation. Experiments with Gal4 DNA binding domain fusion proteins showed that Gal4-PXR was activated by statins while other DR + 3 binding nuclear receptor fusions were not. Overexpression of PXR further enhanced PAI-1 transcription in response to statins. Finally, ChIP experiments using Halo-tagged PXR and RXR demonstrated that both components of the PXR-RXR heterodimer bound to this region of the PAI-1 promoter. PMID:26379245

  14. Enhanced Functional Activity of the Cannabinoid Type-1 Receptor Mediates Adolescent Behavior

    PubMed Central

    Kasanetz, Fernando; Lynch, Diane L.; Friemel, Chris M.; Lassalle, Olivier; Hurst, Dow P.; Steindel, Frauke; Monory, Krisztina; Schäfer, Carola; Miederer, Isabelle; Leweke, F. Markus; Schreckenberger, Mathias; Lutz, Beat; Reggio, Patricia H.; Manzoni, Olivier J.; Spanagel, Rainer

    2015-01-01

    Adolescence is characterized by drastic behavioral adaptations and comprises a particularly vulnerable period for the emergence of various psychiatric disorders. Growing evidence reveals that the pathophysiology of these disorders might derive from aberrations of normal neurodevelopmental changes in the adolescent brain. Understanding the molecular underpinnings of adolescent behavior is therefore critical for understanding the origin of psychopathology, but the molecular mechanisms that trigger adolescent behavior are unknown. Here, we hypothesize that the cannabinoid type-1 receptor (CB1R) may play a critical role in mediating adolescent behavior because enhanced endocannabinoid (eCB) signaling has been suggested to occur transiently during adolescence. To study enhanced CB1R signaling, we introduced a missense mutation (F238L) into the rat Cnr1 gene that encodes for the CB1R. According to our hypothesis, rats with the F238L mutation (Cnr1F238L) should sustain features of adolescent behavior into adulthood. Gain of function of the mutated receptor was demonstrated by in silico modeling and was verified functionally in a series of biochemical and electrophysiological experiments. Mutant rats exhibit an adolescent-like phenotype during adulthood compared with wild-type littermates, with typical high risk/novelty seeking, increased peer interaction, enhanced impulsivity, and augmented reward sensitivity for drug and nondrug reward. Partial inhibition of CB1R activity in Cnr1F238L mutant rats normalized behavior and led to a wild-type phenotype. We conclude that the activity state and functionality of the CB1R is critical for mediating adolescent behavior. These findings implicate the eCB system as an important research target for the neuropathology of adolescent-onset mental health disorders. SIGNIFICANCE STATEMENT We present the first rodent model with a gain-of-function mutation in the cannabinoid type-1 receptor (CB1R). Adult mutant rats exhibit an adolescent

  15. Type 1 IGF receptor translocates to the nucleus of human tumor cells

    PubMed Central

    Aleksic, Tamara; Chitnis, Meenali M.; Perestenko, Olga V.; Gao, Shan; Thomas, Peter H.; Turner, Gareth D.; Protheroe, Andrew S.; Howarth, Mark; Macaulay, Valentine M.

    2010-01-01

    The type 1 insulin-like growth factor receptor (IGF-1R) is a transmembrane glycoprotein comprising two extracellular α subunits and two β subunits with tyrosine kinase activity. The IGF-1R is frequently upregulated in cancers, and signals from the cell surface to promote proliferation and cell survival. Recent attention has focused on the IGF-1R as a target for cancer treatment. Here we report that the nuclei of human tumor cells contain IGF-1R, detectable using multiple antibodies to α- and β- subunit domains. Cell surface IGF-1R translocates to the nucleus following clathrin-mediated endocytosis, regulated by IGF levels. The IGF-1R is unusual among transmembrane receptors that undergo nuclear import, in that both α and β subunits traffic to the nucleus. Nuclear IGF-1R is phosphorylated in response to ligand, and undergoes IGF-induced interaction with chromatin, suggesting direct engagement in transcriptional regulation. The IGF-dependence of these phenomena indicate a requirement for the receptor kinase, and indeed IGF-1R nuclear import and chromatin binding can be blocked by a novel IGF-1R kinase inhibitor. Nuclear IGF-1R is detectable in primary renal cancer cells, formalin-fixed tumors, preinvasive lesions in the breast, and non-malignant tissues characterized by a high proliferation rate. In clear cell renal cancer, nuclear IGF-1R is associated with adverse prognosis. Our findings suggest that IGF-1R nuclear import has biological significance, may contribute directly to IGF-1R function, and may influence the efficacy of IGF-1R inhibitory drugs. PMID:20710042

  16. Binding of Gq protein stabilizes the activated state of the muscarinic receptor type 1.

    PubMed

    Tateyama, Michihiro; Kubo, Yoshihiro

    2013-02-01

    Activation of G protein coupled receptors (GPCRs) induces various cellular responses through interactions with G proteins. The key trigger of GPCR activation is agonist binding. It is reportedly known that the agonist-bound active conformation of the GPCRs, such as the muscarinic acetylcholine receptor type 1 (M(1)R), can be affected by the coupling of G proteins and by depolarization of the membrane potential. Here we aimed at investigating their effects on the structural rearrangements of the M(1)Rs between the active and quiescent states, using the fluorescence resonance energy transfer (FRET) technique. For this purpose, fluorescent M(1)R constructs that maintained intact activation of the Gq pathway and interaction with Gq were used. We captured the agonist-induced conformational changes of the M(1)R as the FRET decreases and found that the FRET decreases were enhanced by co-expression of the Gq subunits. In addition, co-expression of the Gq subunits decelerated the recovery of the declined FRET upon removal of the agonists, which was slower than the dissociation of the Gq subunits from the receptor. These results suggested that Gq binding stabilizes the agonist-induced activated conformation of the M(1)R. We also found that depolarization of the membrane potential slightly but significantly enhanced the agonist-induced FRET decrease, by accelerating the agonist-induced conformational changes. Thus, structural rearrangement analyses by FRET revealed that Gq coupling stabilizes the active conformation of the M(1)R and also suggested that depolarization accelerates the transition from quiescent to activation conformation. PMID:23085334

  17. Overactivation of corticotropin-releasing factor receptor type 1 and aquaporin-4 by hypoxia induces cerebral edema

    PubMed Central

    Chen, Shao-Jun; Yang, Jia-Fang; Kong, Fan-Ping; Ren, Ji-Long; Hao, Ke; Li, Min; Yuan, Yuan; Chen, Xin-Can; Yu, Ri-Sheng; Li, Jun-Fa; Leng, Gareth; Chen, Xue-Qun; Du, Ji-Zeng

    2014-01-01

    Cerebral edema is a potentially life-threatening illness, but knowledge of its underlying mechanisms is limited. Here we report that hypobaric hypoxia induces rat cerebral edema and neuronal apoptosis and increases the expression of corticotrophin releasing factor (CRF), CRF receptor type 1 (CRFR1), aquaporin-4 (AQP4), and endothelin-1 (ET-1) in the cortex. These effects, except for the increased expression of CRF itself, could all be blocked by pretreatment with an antagonist of the CRF receptor CRFR1. We also show that, in cultured primary astrocytes: (i) both CRFR1 and AQP4 are expressed; (ii) exogenous CRF, acting through CRFR1, triggers signaling of cAMP/PKA, intracellular Ca2+, and PKCε; and (iii) the up-regulated cAMP/PKA signaling contributes to the phosphorylation and expression of AQP4 to enhance water influx into astrocytes and produces an up-regulation of ET-1 expression. Finally, using CHO cells transfected with CRFR1+ and AQP4+, we show that transfected CRFR1+ contributes to edema via transfected AQP4+. In conclusion, hypoxia triggers cortical release of CRF, which acts on CRFR1 to trigger signaling of cAMP/PKA in cortical astrocytes, leading to activation of AQP4 and cerebral edema. PMID:25146699

  18. Targeting Anti-Insulin B Cell Receptors Improves Receptor Editing in Type 1 Diabetes-Prone Mice.

    PubMed

    Bonami, Rachel H; Thomas, James W

    2015-11-15

    Autoreactive B lymphocytes that commonly arise in the developing repertoire can be salvaged by receptor editing, a central tolerance mechanism that alters BCR specificity through continued L chain rearrangement. It is unknown whether autoantigens with weak cross-linking potential, such as insulin, elicit receptor editing, or whether this process is dysregulated in related autoimmunity. To resolve these issues, we developed an editing-competent model in which anti-insulin Vκ125 was targeted to the Igκ locus and paired with anti-insulin VH125Tg. Physiologic, circulating insulin increased RAG-2 expression and was associated with BCR replacement that eliminated autoantigen recognition in a proportion of developing anti-insulin B lymphocytes. The proportion of anti-insulin B cells that underwent receptor editing was reduced in the type 1 diabetes-prone NOD strain relative to a nonautoimmune strain. Resistance to editing was associated with increased surface IgM expression on immature (but not transitional or mature) anti-insulin B cells in the NOD strain. The actions of mAb123 on central tolerance were also investigated, because selective targeting of insulin-occupied BCR by mAb123 eliminates anti-insulin B lymphocytes and prevents type 1 diabetes. Autoantigen targeting by mAb123 increased RAG-2 expression and dramatically enhanced BCR replacement in newly developed B lymphocytes. Administering F(ab')2123 induced IgM downregulation and reduced the frequency of anti-insulin B lymphocytes within the polyclonal repertoire of VH125Tg/NOD mice, suggesting enhanced central tolerance by direct BCR interaction. These findings indicate that weak or faulty checkpoints for central tolerance can be overcome by autoantigen-specific immunomodulatory therapy. PMID:26432895

  19. Kinin B1 Receptor Deletion Affects Bone Healing in Type 1 Diabetic Mice.

    PubMed

    Cignachi, Natália P; Pesquero, João B; Oliveira, Rogério B; Etges, Adriana; Campos, Maria M

    2015-12-01

    The effects of kinin B1 receptor (B1 R) deletion were examined on femur bone regeneration in streptozotocin (STZ)-type 1 diabetes. Diabetes induction in wild-type C57/BL6 (WTC57BL6) mice led to decrease in body weight and hyperglycemia, compared to the non-diabetic group of the same strain. The lack of B1 R did not affect STZ-elicited body weight loss, but partially prevented hyperglycemia. Diabetic mice had a clear delay in bone regeneration, and displayed large areas of loose connective tissue within the defects, with a reduced expression of the mineralization-related protein osteonectin, when compared to the non-diabetic WTC57/BL6. The non-diabetic and diabetic B1 R knockout (B1 RKO) mice had bone regeneration levels and osteonectin expression comparable to that seen in control WTC57/BL6 mice. WTC57/BL6 STZ-diabetic mice also showed a marked reduction of collagen contents, with increased immunolabeling for the apoptosis marker caspase-3, whereas diabetic B1 RKO had collagen levels and caspase-3 activity comparable to those observed in non-diabetic WTC57/BL6 or B1 RKO mice. No significant difference was detected in the number of tartrate-resistant acid phosphatase (TRAP)-stained cells, or in RANK/RANKL/OPG system immunolabeling throughout the experimental groups. Data bring novel evidence on the relevance of kinin B1 R under type 1 diabetes with regards to its role in bone regeneration. PMID:25969420

  20. Activated central galanin type 1 receptor alleviated insulin resistance in diabetic rat muscle.

    PubMed

    Bu, Le; Chang, Xusheng; Cheng, Xiaoyun; Yao, Qian; Su, Bin; Sheng, Chunjun; Qu, Shen

    2016-10-01

    Evidence indicates that central galanin is involved in regulation of insulin resistance in animals. This study investigates whether type 1 galanin receptor (GAL1) in the brain mediates the ameliorative effect of galanin on insulin resistance in skeletal muscles of type 2 diabetic rats. Rats were intracerebroventricularly (i.c.v.) injected with galanin(1-13)-bradykinin(2-9) amide (M617), a GAL1 agonist, and/or Akti-1/2, an Akt inhibitor, via caudal veins once per day for 10 days. Insulin resistance in muscle tissues was evaluated by glucose tolerance and 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxyglucose (2-NBDG) tests, peroxisome proliferator-activated receptor-γ (PPARγ), glucose transporter 4 (GLUT4) mRNA expression levels, Akt phosphorylation, and GLUT4 and vesicle-associated membrane protein 2 (VAMP2) concentration at plasma membranes in muscle cells. The results show that i.c.v. treatment with M617 increased glucose tolerance, 2-NBDG uptake, PPARγ levels, Akt phosphorylation, GLUT4 protein, and GLUT4 mRNA expression levels as well as GLUT4 and VAMP2 concentration at plasma membranes. All increases may be blocked by pretreatment with Akti-1/2. These results suggest that activated central GAL1 may trigger the Akt signaling pathway to alleviate insulin resistance in muscle cells. Therefore, the impact of galanin on insulin resistance is mediated mainly by GAL1 in the brain, and the GAL1 agonist may be taken as a potential antidiabetic agent for treatment of type 2 diabetes mellitus. © 2016 Wiley Periodicals, Inc. PMID:27410235

  1. MPZP: a novel small molecule corticotropin-releasing factor type 1 receptor (CRF1) antagonist.

    PubMed

    Richardson, Heather N; Zhao, Yu; Fekete, Eva M; Funk, Cindy K; Wirsching, Peter; Janda, Kim D; Zorrilla, Eric P; Koob, George F

    2008-02-01

    The extrahypothalamic stress peptide corticotropin-releasing factor (CRF) system is an important regulator of behavioral responses to stress. Dysregulation of CRF and the CRF type 1 receptor (CRF(1)) system is hypothesized to underlie many stress-related disorders. Modulation of the CRF(1) system by non-peptide antagonists currently is being explored as a therapeutic approach for anxiety disorders and alcohol dependence. Here, we describe a new, less hydrophilic (cLogP approximately 2.95), small molecule, non-peptide CRF(1) antagonist with high affinity (K(i)=4.9 nM) and specificity for CRF(1) receptors: N,N-bis(2-methoxyethyl)-3-(4-methoxy-2-methylphenyl)-2,5-dimethyl-pyrazolo[1,5-a] pyrimidin-7-amine (MPZP). The compound was systemically administered to adult male rats in two behavioral models dependent on the CRF(1) system: defensive burying (0, 5, 20 mg/kg, n=6-11 for each dose) and alcohol dependence (0, 5, 10, 20 mg/kg, n=8 for each self-administration group). Acute administration of MPZP reduced burying behavior in the defensive burying model of active anxiety-like behavior. MPZP also attenuated withdrawal-induced excessive drinking in the self-administration model of alcohol dependence without affecting nondependent alcohol drinking or water consumption. The present findings support the proposed significance of the CRF(1) system in anxiety and alcohol dependence and introduce a promising new compound for further development in the treatment of alcohol dependence and stress-related disorders. PMID:18031798

  2. Exercise reduces adipose tissue via cannabinoid receptor type 1 which is regulated by peroxisome proliferator-activated receptor-delta.

    PubMed

    Yan, Zhen Cheng; Liu, Dao Yan; Zhang, Li Li; Shen, Chen Yi; Ma, Qun Li; Cao, Ting Bing; Wang, Li Juan; Nie, Hai; Zidek, Walter; Tepel, Martin; Zhu, Zhi Ming

    2007-03-01

    Obesity is one major cardiovascular risk factor. We tested effects of endurance exercise on cannabinoid receptor type 1 (CB1) and peroxisome proliferator-activated receptor-delta (PPAR-delta)-dependent pathways in adipose tissue. Male Wistar rats were randomly assigned to standard laboratory chow or a high-fat diet without and with regular endurance exercise. Exercise in rats on high-fat diet significantly reduced visceral fat mass, blood pressure, and adipocyte size (each p<0.05). Adipocyte hypertrophy induced by high-fat diet was accompanied by increased CB1 expression in adipose tissue, whereas exercise significantly reduced CB1 expression (each p<0.05). CB1 receptor expression and adipocyte differentiation were directly regulated by PPAR-delta. Adipocyte hypertrophy induced by high-fat diet was accompanied by reduced PPAR-delta. Furthermore, selective silencing of PPAR-delta by RNA interference in 3T3-L1-preadipocyte cells significantly increased CB1 expression from 1.00+/-0.06 (n=3) to 1.91+/-0.06 (n=3; p<0.01) and increased adipocyte differentiation, whereas adenovirus-mediated overexpression of PPAR-delta significantly reduced CB1 expression to 0.39+/-0.03 (n=3; p<0.01) and reduced adipocyte differentiation. In the presence of the CB1 antagonist rimonabant adipocyte differentiation in stimulated 3T3 L1 preadipocyte cells was significantly reduced. The study indicates that high-fat diet-induced hypertrophy of adipocytes is associated with increased CB1 receptor expression which is directly regulated by PPAR-delta. Both CB1 and PPAR-delta are intimately involved in therapeutic interventions against a most important cardiovascular risk factor. PMID:17223076

  3. Exercise reduces adipose tissue via cannabinoid receptor type 1 which is regulated by peroxisome proliferator-activated receptor-{delta}

    SciTech Connect

    Yan Zhencheng; Liu Daoyan; Zhang Lili; Shen Chenyi; Ma Qunli; Cao Tingbing; Wang Lijuan; Nie Hai; Zidek, Walter; Tepel, Martin; Zhu Zhiming . E-mail: zhuzm@yahoo.com

    2007-03-09

    Obesity is one major cardiovascular risk factor. We tested effects of endurance exercise on cannabinoid receptor type 1 (CB1) and peroxisome proliferator-activated receptor-{delta} (PPAR-{delta})-dependent pathways in adipose tissue. Male Wistar rats were randomly assigned to standard laboratory chow or a high-fat diet without and with regular endurance exercise. Exercise in rats on high-fat diet significantly reduced visceral fat mass, blood pressure, and adipocyte size (each p < 0.05). Adipocyte hypertrophy induced by high-fat diet was accompanied by increased CB1 expression in adipose tissue, whereas exercise significantly reduced CB1 expression (each p < 0.05). CB1 receptor expression and adipocyte differentiation were directly regulated by PPAR-{delta}. Adipocyte hypertrophy induced by high-fat diet was accompanied by reduced PPAR-{delta}. Furthermore, selective silencing of PPAR-{delta} by RNA interference in 3T3-L1-preadipocyte cells significantly increased CB1 expression from 1.00 {+-} 0.06 (n = 3) to 1.91 {+-} 0.06 (n = 3; p < 0.01) and increased adipocyte differentiation, whereas adenovirus-mediated overexpression of PPAR-{delta} significantly reduced CB1 expression to 0.39 {+-} 0.03 (n = 3; p < 0.01) and reduced adipocyte differentiation. In the presence of the CB1 antagonist rimonabant adipocyte differentiation in stimulated 3T3 L1 preadipocyte cells was significantly reduced. The study indicates that high-fat diet-induced hypertrophy of adipocytes is associated with increased CB1 receptor expression which is directly regulated by PPAR-{delta}. Both CB1 and PPAR-{delta} are intimately involved in therapeutic interventions against a most important cardiovascular risk factor.

  4. Of the multiple mechanisms leading to type 1 diabetes, T cell receptor revision may play a prominent role (is type 1 diabetes more than a single disease?).

    PubMed

    Wagner, D H

    2016-09-01

    A single determinant factor for autoimmunity does not exist; disease development probably involves contributions from genetics, the environment and immune dysfunction. Type 1 diabetes is no exception. Genomewide-associated studies (GWAS) analysis in T1D has proved disappointing in revealing contributors to disease prediction; the only reliable marker has been human leucocyte antigen (HLA). Specific HLAs include DR3/DR4/DQ2/DQ8, for example. Because HLA molecules present antigen to T cells, it is reasonable that certain HLA molecules have a higher affinity to present self-antigen. Recent studies have shown that additional polymorphisms in HLA that are restricted to autoimmune conditions are further contributory. A caveat is that not all individuals with the appropriate 'pro-autoimmune' HLA develop an autoimmune disease. Another crucial component is autoaggressive T cells. Finding a biomarker to discriminate autoaggressive T cells has been elusive. However, a subset of CD4 helper cells that express the CD40 receptor have been described as becoming pathogenic. An interesting function of CD40 on T cells is to induce the recombination-activating gene (RAG)1/RAG2 T cell receptor recombination machinery. This observation is contrary to immunology paradigms that changes in TCR molecules cannot take place outside the thymic microenvironment. Alteration in TCR, called TCR revision, not only occurs, but may help to account for the development of autoaggressive T cells. Another interesting facet is that type 1 diabetes (T1D) may be more than a single disease; that is, multiple cellular components contribute uniquely, but result ultimately in the same clinical outcome, T1D. This review considers the process of T cell maturation and how that could favor auto-aggressive T cell development in T1D. The potential contribution of TCR revision to autoimmunity is also considered. PMID:27271348

  5. Astrocytic expression of cannabinoid type 1 receptor in rat and human sclerotic hippocampi

    PubMed Central

    Meng, Xian-Dong; Wei, Dong; Li, Juan; Kang, Jun-Jun; Wu, Chen; Ma, Lei; Yang, Feng; Zhu, Ge-Min; Ou-Yang, Tang-Peng; Liu, Ying-Ying; Jiang, Wen

    2014-01-01

    Cannabinoid type 1 receptor (CB1R), which is traditionally located on axon terminals, plays an important role in the pathology of epilepsy and neurodegenerative diseases by modulating synaptic transmission. Using the pilocarpine model of chronic spontaneous recurrent seizures, which mimics the main features of mesial temporal lobe epilepsy (TLE) with hippocampal sclerosis (HS) in humans, we examined the expression of CB1R in hippocampal astrocytes of epileptic rats. Furthermore, we also examined the expression of astrocytic CB1R in the resected hippocampi from patients with medically refractory mesial TLE. Using immunofluorescent double labeling, we found increased expression of astrocytic CB1R in hippocampi of epileptic rats, whereas expression of astrocytic CB1R was not detectable in hippocampi of saline treated animals. Furthermore, CB1R was also found in some astrocytes in sclerotic hippocampi in a subset of patients with intractable mesial TLE. Detection with immune electron microscopy showed that the expression of CB1R was increased in astrocytes of epileptic rats and modest levels of CB1R were also found on the astrocytic membrane of sclerotic hippocampi. These results suggest that increased expression of astrocytic CB1R in sclerotic hippocampi might be involved in the cellular basis of the effects of cannabinoids on epilepsy. PMID:25031702

  6. Induction of type 1 interferon receptor by zinc in U937 cells.

    PubMed

    Nagamine, Takeaki; Nakajima, Kastuyuki; Takada, Hisashi; Sekine, Yoshitaka; Suzuki, Kazuhiro

    2009-06-01

    This study aims to determine whether zinc enhances interferon (IFN)-alpha activity in U937 cells. Type 1 IFN2 receptor (IFNAR2) protein in U937 cells was measured by flow cytometry. After 24h of exposure to zinc chloride or polaprezinc (a chelate of zinc and L-carnosine) at concentrations ranging from 50 to 200 microM, histograms showing anti-IFNAR2 antibody-positive cells shifted to a higher FITC intensity. Zinc chloride and polaprezinc increased IFNAR2 mRNA levels approximately 30% and 40%, respectively, compared to the control. L-carnosine alone did not alter IFNAR2 mRNA or protein levels. Cellular levels of 2'-5' oligoadenylate synthetases (OAS) were markedly increased by IFN-alpha, and the increase was significantly accelerated by polaprezinc. However, polaprezinc alone did not increase 2'-5'OAS levels. The finding suggests that zinc, especially polaprezinc, enhances the expression of INFAR2 in U937 cells, thereby inducing production of the anti-viral protein 2'-5'OAS. PMID:19362011

  7. Parathyroid hormone and parathyroid hormone type-1 receptor accelerate myocyte differentiation

    PubMed Central

    Kimura, Shigemi; Yoshioka, Kowasi

    2014-01-01

    The ZHTc6-MyoD embryonic stem cell line expresses the myogenic transcriptional factor MyoD under the control of a tetracycline-inducible promoter. Following induction, most of the ZHTc6-MyoD cells differentiate to myotubes. However, a small fraction does not differentiate, instead forming colonies that retain the potential for myocyte differentiation. In our current study, we found that parathyroid hormone type 1 receptor (PTH1R) expression in colony-forming cells at 13 days after differentiation was higher than that in the undifferentiated ZHTc6-MyoD cells. We also found that PTH1R expression was required for myocyte differentiation, and that parathyroid hormone accelerated the differentiation. Our analysis of human and mouse skeletal muscle tissues showed that most cells expressing PTH1R also expressed Pax7 and CD34, which are biomarkers of satellite cells. Furthermore, we found that parathyroid hormone treatment significantly improved muscle weakness in dystrophin-deficient mdx mice. This is the first report indicating that PTH1R and PTH accelerate myocyte differentiation. PMID:24919035

  8. Cortical dopamine D2 receptors in type 1 and 2 alcoholics measured with human whole hemisphere autoradiography.

    PubMed

    Tupala, Erkki; Hall, Håkan; Halonen, Pirjo; Tiihonen, Jari

    2004-12-01

    Alcoholism has been associated with lower density of striatal dopamine (DA) D(2) receptors, but there is much less data on cortical DA D(2) receptors. We evaluated the [(125)I]epidepride binding to DA D(2) receptors in Cloninger type 1 and 2 alcoholics and controls in frontal, temporal, and anterior cingulate cortices by using human postmortem whole hemispheric autoradiography, which provides high-resolution images corresponding to positron emission tomographic (PET) studies. Type 1 alcoholics had lower and type 2 alcoholics had higher DA D(2) receptor density in all cortical areas compared to controls. Although the results did not reach statistical significance, the effect sizes were high. The DA D(2) receptor density in type 2 alcoholics decreased statistically significantly with age, and after correcting for age the binding values also fell below the level of controls. A statistically non-significant tendency towards a decrease of cortical DA D(2) receptors was seen in controls, whereas in the type 1 alcoholic group no consistent correlation or even tendency towards increase with age was observed. Our results give preliminary evidence that DA D(2) receptors in cortical areas may be lower among both groups of alcoholics, but not necessarily of same magnitude as in subcortical structures. The rapid decline of cortical DA D(2) receptors among type 2 alcoholics may have some relevance to their antisociality, because this trait tends to diminish with age. The absence of correlation or even tendency towards increase of cortical DA D(2) receptors with age seen in type 1 alcoholics may give further evidence that they have a pre-existing dopaminergic deficit. However, these results especially regarding aging effect must be considered as preliminary due to the different age-range of type 2 alcoholics compared to two other groups. PMID:15452867

  9. Documentation of angiotensin II receptors in glomerular epithelial cells

    NASA Technical Reports Server (NTRS)

    Sharma, M.; Sharma, R.; Greene, A. S.; McCarthy, E. T.; Savin, V. J.; Cowley, A. W. (Principal Investigator)

    1998-01-01

    Angiotensin II decreases glomerular filtration rate, renal plasma flow, and glomerular capillary hydraulic conductivity. Although angiotensin II receptors have been demonstrated in mesangial cells and proximal tubule cells, the presence of angiotensin II receptors in glomerular epithelial cells has not previously been shown. Previously, we have reported that angiotensin II caused an accumulation of cAMP and a reorganization of the actin cytoskeleton in cultured glomerular epithelial cells. Current studies were conducted to verify the presence of angiotensin II receptors by immunological and non-peptide receptor ligand binding techniques and to ascertain the activation of intracellular signal transduction in glomerular epithelial cells in response to angiotensin II. Confluent monolayer cultures of glomerular epithelial cells were incubated with angiotensin II, with or without losartan and/or PD-123,319 in the medium. Membrane vesicle preparations were obtained by homogenization of washed cells followed by centrifugation. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of membrane proteins followed by multiscreen immunoblotting was used to determine the presence of angiotensin II receptor type 1 (AT1) or type 2 (AT2). Angiotensin II-mediated signal transduction in glomerular epithelial cells was studied by measuring the levels of cAMP, using radioimmunoassay. Results obtained in these experiments showed the presence of both AT1 and AT2 receptor types in glomerular epithelial cells. Angiotensin II was found to cause an accumulation of cAMP in glomerular epithelial cells, which could be prevented only by simultaneous use of losartan and PD-123,319, antagonists for AT1 and AT2, respectively. The presence of both AT1 and AT2 receptors and an increase in cAMP indicate that glomerular epithelial cells respond to angiotensin II in a manner distinct from that of mesangial cells or proximal tubular epithelial cells. Our results suggest that glomerular epithelial

  10. Enhanced type 1alpha metabotropic glutamate receptor-stimulated phosphoinositide signaling after pertussis toxin treatment.

    PubMed

    Carruthers, A M; Challiss, R A; Mistry, R; Saunders, R; Thomsen, C; Nahorski, S R

    1997-09-01

    The regulation of phosphoinositide hydrolysis by the type 1alpha metabotropic glutamate receptor (mGluR1alpha) was investigated in stably transfected baby hamster kidney (BHK) cells. Incubation of the cells with L-glutamate, quisqualate, and 1-aminocyclopentane-1S, 3R-dicarboxylic acid resulted in a marked accumulation of [3H]inositol monophosphate (InsP1) and inositol-1,4,5-trisphosphate [Ins(1,4,5)P3] mass in a time- and concentration-dependent manner. Pretreatment of BHK-mGluR1alpha cells with pertussis toxin [ 100 ng/ml, 24 hr] led to a dramatic 12-16-fold increase in the accumulation of [3H]InsP1 and a 2-fold increase in Ins(1,4,5)P3 in the absence of added agonist. Although only very low levels (/=75%, and the EC50 shifted leftward by 65-fold [-log EC50 values (molar), 7.26 +/- 0.23 versus 5.45 +/- 0.07; n = 4) in PTX-treated compared with control cells. In contrast, antagonist effects on agonist-stimulated [3H]InsP1 responses were similar in control and PTX-treated BHK-mGluR1alpha cells. These changes in the concentration-effect curves for mGluR agonists are consistent with a model in which the receptor associates with PTX-sensitive inhibitory (Gi/o) and PTX-insensitive stimulatory (Gq/11) G proteins that can each influence PIC activity. The present observations are consistent with a dual regulation of mGluR1alpha-mediated PIC activity that could be fundamental in

  11. Clonidine displacement from type 1 imidazoline receptor by p-aminobenzamidine, the prototype of trypsin-like serine protease inhibitors.

    PubMed

    Pallottini, Valentina; Marino, Maria; Ascenzi, Paolo

    2002-11-01

    p-Aminobenzamidine inhibits competitively the catalytic activity of enzymes that recognize preferentially the L-arginyl side chain and related structures. Notably, p-aminobenzamidine is considered as the prototype of trypsin-like serine protease inhibitors. Furthermore, p-aminobenzamidine inhibits the catalytic activity of nitric oxide synthase type I and type II as well as copper amine oxidase. Taking into account the structural similarity between p-aminobenzamidine, agmatine (the putative endogenous ligand of the membrane type 1 imidazoline receptor (I1-R)), and N-amidino-2-hydroxypyrrolidine (the product of agmatine oxidation by copper amine oxidase), the [3H]clonidine displacement from I1-R in rat heart membranes by p-aminobenzamidine was investigated. p-Aminobenzamidine is as effective as agmatine and N-amidino-2-hydroxypyrrolidine and more effective than the antihypertensive drug clonidine to displace [3H]clonidine from I1-R. Therefore, trypsin-like serine protease inhibitors structurally related to p-aminobenzamidine should be administrated under careful control. PMID:12587981

  12. Angiotensin type 1a receptors on corticotropin-releasing factor neurons contribute to the expression of conditioned fear.

    PubMed

    Hurt, R C; Garrett, J C; Keifer, O P; Linares, A; Couling, L; Speth, R C; Ressler, K J; Marvar, P J

    2015-09-01

    Although generally associated with cardiovascular regulation, angiotensin II receptor type 1a (AT1a R) blockade in mouse models and humans has also been associated with enhanced fear extinction and decreased post-traumatic stress disorder (PTSD) symptom severity, respectively. The mechanisms mediating these effects remain unknown, but may involve alterations in the activities of corticotropin-releasing factor (CRF)-expressing cells, which are known to be involved in fear regulation. To test the hypothesis that AT1a R signaling in CRFergic neurons is involved in conditioned fear expression, we generated and characterized a conditional knockout mouse strain with a deletion of the AT1a R gene from its CRF-releasing cells (CRF-AT1a R((-/-)) ). These mice exhibit normal baseline heart rate, blood pressure, anxiety and locomotion, and freeze at normal levels during acquisition of auditory fear conditioning. However, CRF-AT1a R((-/-)) mice exhibit less freezing than wild-type mice during tests of conditioned fear expression-an effect that may be caused by a decrease in the consolidation of fear memory. These results suggest that central AT1a R activity in CRF-expressing cells plays a role in the expression of conditioned fear, and identify CRFergic cells as a population on which AT1 R antagonists may act to modulate fear extinction. PMID:26257395

  13. Type 1 cannabinoid receptor modulates water deprivation-induced homeostatic responses.

    PubMed

    Ruginsk, Silvia G; Vechiato, Fernanda M V; Uchoa, Ernane T; Elias, Lucila L K; Antunes-Rodrigues, Jose

    2015-12-01

    The present study investigated the type 1 cannabinoid receptor (CB1R) as a potential candidate to mediate the homeostatic responses triggered by 24 h of water deprivation, which constitutes primarily a hydroelectrolytic challenge and also significantly impacts energy homeostasis. The present results demonstrated for the first time that CB1R mRNA expression is increased in the hypothalamus of water-deprived (WD) rats. Furthermore, the administration of ACEA, a CB1R selective agonist, potentiated WD-induced dipsogenic effect, whereas AM251, a CB1R antagonist, attenuated not only water but also salt intake in response to WD. In parallel with the modulation of thirst and salt appetite, we confirmed that CB1Rs are essential for the development of appropriated neuroendocrine responses. Although the administration of ACEA or AM251 did not produce any effects on WD-induced arginine vasopressin (AVP) secretion, oxytocin (OXT) plasma concentrations were significantly decreased in WD rats treated with ACEA. At the genomic level, ACEA significantly decreased AVP and OXT mRNA expression in the hypothalamus of WD rats, whereas AM251 potentiated both basal and WD-induced stimulatory effects on the transcription of AVP and OXT genes. In addition, we showed that water deprivation alone upregulated proopiomelanocortin, Agouti-related peptide, melanin-concentrating hormone, and orexin A mRNA levels in the hypothalamus, and that CB1Rs regulate main central peptidergic pathways controlling food intake, being that most of these effects were also significantly influenced by the hydration status. In conclusion, the present study demonstrated that CB1Rs participate in the homeostatic responses regulating fluid balance and energy homeostasis during water deprivation. PMID:26468265

  14. Binding Selectivity of Abaloparatide for PTH-Type-1-Receptor Conformations and Effects on Downstream Signaling.

    PubMed

    Hattersley, Gary; Dean, Thomas; Corbin, Braden A; Bahar, Hila; Gardella, Thomas J

    2016-01-01

    The PTH receptor type 1 (PTHR1) mediates the actions of two endogenous polypeptide ligands, PTH and PTHrP, and thereby plays key roles in bone biology. Based on its capacity to stimulate bone formation, the peptide fragment PTH (1-34) is currently in use as therapy for osteoporosis. Abaloparatide (ABL) is a novel synthetic analog of human PTHrP (1-34) that holds promise as a new osteoporosis therapy, as studies in animals suggest that it can stimulate bone formation with less of the accompanying bone resorption and hypercalcemic effects that can occur with PTH (1-34). Recent studies in vitro suggest that certain PTH or PTHrP ligand analogs can distinguish between two high-affinity PTHR1 conformations, R(0) and RG, and that efficient binding to R(0) results in prolonged signaling responses in cells and prolonged calcemic responses in animals, whereas selective binding to RG results in more transient responses. As intermittent PTH ligand action is known to favor the bone-formation response, whereas continuous ligand action favors the net bone-resorption/calcemic response, we hypothesized that ABL binds more selectively to the RG vs the R(0) PTHR1 conformation than does PTH (1-34), and thus induces more transient signaling responses in cells. We show that ABL indeed binds with greater selectivity to the RG conformation than does PTH (1-34), and as a result of this RG bias, ABL mediates more transient cAMP responses in PTHR1-expressing cells. The findings provide a plausible mechanism (ie, transient signaling via RG-selective binding) that can help account for the favorable anabolic effects that ABL has on bone. PMID:26562265

  15. Dopamine D2 receptors and transporters in type 1 and 2 alcoholics measured with human whole hemisphere autoradiography.

    PubMed

    Tupala, Erkki; Hall, Håkan; Bergström, Kim; Mantere, Tuija; Räsänen, Pirkko; Särkioja, Terttu; Tiihonen, Jari

    2003-10-01

    Increasing evidence implies the involvement of the dopamine (DA) system in the pathogenesis of alcoholism. We measured striatal DA D(2) receptors in Cloninger type 1 and 2 alcoholics by using [(125)I]epidepride in human postmortem whole hemispheric autoradiography (WHA), which provides high-resolution images corresponding to positron emission tomographic (PET) studies. We also evaluated the correlation between transporter and receptor DA binding site densities and putative correlation of [(125)I]epidepride binding between the dorsal striatum and nucleus accumbens. In the type 1 alcoholics, the DA D(2) receptor density was 21.4-32.6% lower in all dorsal striatal structures (caudate, putamen, globus pallidus) when compared with the controls. Type 2 alcoholics had 19.6-21.4% lower binding in other dorsal striatal structures, except medial globus pallidus, where they were not significantly different from controls. The density of DA D(2) receptors and DAT had a significant positive correlation only in the putamen of type 1 alcoholics. The binding of [(125)I]epidepride showed also consistent and statistically significant positive correlation between nucleus accumbens and all dorsal striatal areas in type 1 alcoholics but not in the controls. In the type 2 alcoholics, the correlation was weaker than that observed in the type 1 alcoholics, and no correlation was observed between nucleus accumbens and globus pallidus. Our results show that these two subgroups of alcoholics have stark differences in their DA D(2) receptor binding characteristics. Type 2 alcoholics may have selective deficiency in the dorsal striatum, whereas in limbic structures they may not differ significantly from controls. Moreover, WHA provides a useful tool for detailed mapping of neuronal receptors in healthy as well as diseased brain, and can also be used in radioligand development for PET. PMID:14505335

  16. The association between type 1 diabetes and the ITPR3 gene polymorphism due to linkage disequilibrium with HLA class II.

    PubMed

    Qu, H-Q; Marchand, L; Szymborski, A; Grabs, R; Polychronakos, C

    2008-04-01

    A fine mapping study of the MHC region in a Swedish case-control population sample reported a novel type 1 diabetes (T1D) association from the inositol 1-, 4-, 5-trisphosphate receptor type 3 gene (ITPR3) in a case-control study, reportedly independent of the HLA class II effect. We attempted to replicate this novel association in a family-based study of 1120 T1D families with at least one affected child, an approach immune to population stratification. We found association of the ITPR3 single nucleotide polymorphisms (SNPs) rs2296336 with T1D but in a direction opposite to that reported. Moreover, rs2296336 was in linkage disequilibrium (LD) with specific alleles of the HLA DQB1 gene. Conditional regression showed that all of the ITPR3 SNP T1D association could be accounted for by the DQB1 effect. Therefore, our findings do not support an obvious role of genetic variation of the ITPR3 gene in T1D risk. PMID:18340361

  17. Nicotinic acetylcholine receptors regulate type 1 inositol 1,4,5-trisphosphate receptor expression via calmodulin kinase IV activation.

    PubMed

    Mizuno, Koji; Kurokawa, Kazuhiro; Ohkuma, Seitaro

    2015-04-01

    Type 1 inositol 1,4,5-trisphosphate receptors (IP3 R-1) are among the important calcium channels regulating intracellular Ca(2+) concentration in the central nervous system. In a previous study, we showed that drugs of abuse, such as cocaine, methamphetamine, and ethanol, induced IP3 R-1 upregulation via the calcium signal transduction pathway in psychological dependence. Although nicotine, a major component in tobacco smoke, participates in psychological and/or physical dependence, it has not yet been clarified how nicotine alters IP3 R-1 expression. The present study, therefore, seeks to clarify the mechanism bgy which nicotine modifies IP3 R-1 expression by using mouse cerebral cortical neurons in primary culture. Nicotine induced dose- and time-dependent upregulation of IP3 R-1 protein following its mRNA increase, and the latter was significantly suppressed by a nonselective nicotinic acetylcholine receptors (nAChR) antagonist, mecamylamine. Both cFos and phosphorylated-cJun (p-cJun) were immediately increased in the nucleus, together with an increase of calmodulin kinase (CaMK) IV but not CaMKII expression after nicotine exposure. A nonselective inhibitor of CaMKs, KN-93, and a calcium chelating regent, BAPTA-AM, completely suppressed the expression of cFos and p-cJun in the nucleus as well as the nicotine-induced IP3 R-1 upregulation. These results indicate that nAChR activation by nicotine upregulates IP3 R-1 via increase of activator protein-1, which is a cFos and cJun dimmer, in the nucleus, with activation of Ca(2+) signaling transduction processes. PMID:25430056

  18. Organization of Ca2+ stores in myeloid cells: association of SERCA2b and the type-1 inositol-1,4,5-trisphosphate receptor.

    PubMed Central

    Favre, C J; Jerström, P; Foti, M; Stendhal, O; Huggler, E; Lew, D P; Krause, K H

    1996-01-01

    In this study, we have analysed the relationship between Ca2+ pumps and Ins(1,4,5)P3-sensitive Ca2+ channels in myeloid cells. To study whether sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPase (SERCA)-type Ca(2+)-ATPases are responsible for Ca2+ uptake into Ins(1,4,5)P3-sensitive Ca2+ stores, we used the three structurally unrelated inhibitors thapsigargin, 2,5-di-t-butylhydroquinone and cyclopiazonic acid. In HL-60 cells, all three compounds precluded formation of the phosphorylated intermediate of SERCA-type Ca(2+)-ATPases. They also decreased, in parallel, ATP-dependent Ca2+ accumulation and the amount of Ins(1,4,5)P3-releasable Ca2+. Immunoblotting with subtype-directed antibodies demonstrated that HL-60 cells contain the Ca2+ pump SERCA2 (subtype b), and the Ca(2+)-release-channel type-1 Ins(1,4,5)P3 receptor. In subcellular fractionation studies, SERCA2 and type-1 Ins(1,4,5)P3 receptor co-purified. Immunofluorescence studies demonstrated that both type-1 Ins(1,4,5)P3 receptor and SERCA2 were evenly distributed throughout the cell in moving neutrophils. During phagocytosis both proteins translocated to the periphagosomal space. Taken together, our results suggest that in myeloid cells (i) SERCA-type Ca(2+)-ATPases function as Ca2+ pumps of Ins(1,4,5)P3-sensitive Ca2+ stores, and (ii) SERCA2 and type-1 Ins(1,4,5)P3 receptor reside either in the same or two tightly associated subcellular compartments. PMID:8645196

  19. SPECT imaging of neuropilin receptor type-1 expression with 131I-labeled monoclonal antibody.

    PubMed

    Dou, Xiaofeng; Yan, Jianghua; Zhang, Yafei; Liu, Peng; Jiang, Yizhen; Lv, Sha; Zeng, Fanwei; Chen, Xiaoli; Wang, Shengyu; Zhang, Haipeng; Wu, Hua; Zhang, Hong; Ouyang, Lin; Su, Xinhui

    2016-09-01

    As a novel co-receptor for vascular endothelial growth factor (VEGF), neuropilin receptor type-1 (NRP-1) is overexpressed in several cancers and metastases, and serves as an attractive target for cancer molecular imaging and therapy. Previous single photon emission computerized tomography (SPECT) studies demonstrated that the small NRP-1-targeting peptides 99mTc-MA-ATWLPPR and 99mTc-CK3 showed poor tumor imaging quality, because of their rapid blood clearance and very low tumor uptake. Compared with small peptides, monoclonal antibodies (mAbs) can improve imaging of NRP-1-expression, due to their high affinity, specificity and slow extraction. A6-11-26 is a novel monoclonal antibody against NRP-1 b1b2 domain that exhibits inhibition of tumor growth in NPR-1-expressing preclinical models. The aim of the present study was to develop the 131I-labeled anti-NRP-1 monoclonal antibody A6-11-26 as a SPECT probe for imaging of NRP-1-positive tumor. An anti-NRP-1 monoclonal antibody (A6-11-26) was produced by hybridomas and was labeled with iodine-131 by the iodogen method. In vitro, the radiolabeling efficiency, radiochemical purity, immunoreactive fraction and stability were assessed. Binding affinity and specificity of 131I‑A6-11-26 to NRP-1 were evaluated using human glioblastoma U87MG cells. In vivo, biodistribution and SPECT/CT studies were conducted on mice bearing U87MG xenografts after the injection of 131I-A6-11-26 with or without co-injection of unlabeled A6-11-26 antibody. A6-11-26 was generated successfully by hybridoma with high purity (>95%) and was labeled with iodine-131 within 60 min with high labelling efficiency (95.46±3.34%), radiochemical purity (98.23±1.41%). 131I-A6-11-26 retained its immunoreactivity and also displayed excellent stability in mouse serum and PBS solution during 1 to 96 h. Cell uptake assays showed high NRP-1-specific uptake (15.80±1.30% applied activity at 6 h) in U87MG cells. 131I-A6-11-26 bound to NRP-1 with low nanomolar

  20. Striatal dopamine D1 receptors in type 1 and 2 alcoholics measured with human whole hemisphere autoradiography.

    PubMed

    Tupala, Erkki; Tiihonen, Jari

    2005-01-01

    A considerable number of human and animal studies have implied the importance of dopamine system and alterations in dopamine receptors in the context of alcoholism. However, it has remained unclear if the alcohol-abuse related dopaminergic deficit is specifically associated with certain receptor subtype. The aim of this study was to compare putative alterations of dopamine D(1) receptors in caudate and putamen of nine type 1 alcoholics, eight type 2 alcoholics and 10 healthy controls by using [(3)H]SCH 23390 as a radioligand in postmortem human whole hemisphere autoradiography. In addition, we compared the present results to our earlier studies on dopamine transporters and dopamine D(2) receptors in these same subjects and evaluated the putative correlations of dopamine D(1) receptor densities between the nucleus accumbens and the above-mentioned structures. Our results show that alcoholics do not have significantly different striatal dopamine D(1) receptor densities compared to controls. Neither were there any significant correlations between the dopamine D(1) receptors and the two other dopamine binding sites. However, the correlations of the dopamine D(1) receptors between nucleus accumbens and dorsal striatal structures were consistently and mostly statistically significantly positive in alcoholics, but not in controls, which may suggest some pathology related to addiction. In addition, considering the facts that dopamine D(1) receptors were more abundant in the mesolimbic nucleus accumbens than in the caudate or putamen and that there was a strong tendency towards lower binding among type 1 alcoholics may suggest the importance of dopamine D(1) receptors in reward and/or alcoholism. PMID:15621009

  1. Specific binding and laterality of human extrastriatal dopamine D2/D3 receptors in late onset type 1 alcoholic patients.

    PubMed

    Kuikka, J T; Repo, E; Bergström, K A; Tupala, E; Tiihonen, J

    2000-09-29

    Late onset type 1 alcoholism has been suggested to be associated with decreased dopaminergic transmission. Our hypothesis was that late onset type 1 alcoholics have also abnormal extrastriatal dopamine D(2)/D(3) receptor distribution. We performed binding, heterogeneity and laterality analysis of extrastriatal and striatal dopamine D(2)/D(3) receptors in nine late onset male alcoholics and in 12 age-matched healthy males. A radioligand, [(123)I]epidepride was used in high resolution single-photon emission tomography (SPET). Specific binding of epidepride in the left temporal pole was significantly (P<0.05) lower in type 1 alcoholics (0.74+/-0.14 ml/ml) than in controls (0.89+/-0.14 ml/ml). In alcoholics, there was no normal left-to-right asymmetry of the temporal cortical heterogeneity of epidepride distribution observed in control males (0.89+/-0.19 vs. 1.10+/-0.19; P<0.05). The results suggest that the specific binding of dopamine D(2)/D(3) receptors in late type 1 alcoholics is decreased and its laterality in the temporal brain is altered from normal. PMID:10996449

  2. Impact of Angiotensin Type 1A Receptors in Principal Cells of the Collecting Duct on Blood Pressure and Hypertension.

    PubMed

    Chen, Daian; Stegbauer, Johannes; Sparks, Matthew A; Kohan, Donald; Griffiths, Robert; Herrera, Marcela; Gurley, Susan B; Coffman, Thomas M

    2016-06-01

    The main actions of the renin-angiotensin system to control blood pressure (BP) are mediated by the angiotensin type 1 receptors (AT1Rs). The major murine AT1R isoform, AT1AR, is expressed throughout the nephron, including the collecting duct in both principal and intercalated cells. Principal cells play the major role in sodium and water reabsorption. Although aldosterone is considered to be the dominant regulator of sodium reabsorption by principal cells, recent studies suggest a role for direct actions of AT1R. To specifically examine the contributions of AT1AR in principal cells to BP regulation and the development of hypertension in vivo, we generated inbred 129/SvEv mice with deletion of AT1AR from principal cells (PCKO). At baseline, we found that BPs measured by radiotelemetry were similar between PCKOs and controls. During 1-week of low-salt diet (<0.02% NaCl), BPs fell significantly (P<0.05) and to a similar extent in both groups. On a high-salt (6% NaCl) diet, BP increased but was not different between groups. During the initial phase of angiotensin II-dependent hypertension, there was a modest but significant attenuation of hypertension in PCKOs (163±6 mm Hg) compared with controls (178±2 mm Hg; P<0.05) that was associated with enhanced natriuresis and decreased alpha epithelial sodium channel activation in the medulla of PCKOs. However, from day 9 onward, BPs were indistinguishable between groups. Although effects of AT1AR on baseline BP and adaptation to changes in dietary salt are negligible, our studies suggest that direct actions of AT1AR contribute to the initiation of hypertension and epithelial sodium channel activation. PMID:27141055

  3. Orphan nuclear receptor oestrogen-related receptor γ (ERRγ) plays a key role in hepatic cannabinoid receptor type 1-mediated induction of CYP7A1 gene expression.

    PubMed

    Zhang, Yaochen; Kim, Don-Kyu; Lee, Ji-Min; Park, Seung Bum; Jeong, Won-Il; Kim, Seong Heon; Lee, In-Kyu; Lee, Chul-Ho; Chiang, John Y L; Choi, Hueng-Sik

    2015-09-01

    Bile acids are primarily synthesized from cholesterol in the liver and have important roles in dietary lipid absorption and cholesterol homoeostasis. Detailed roles of the orphan nuclear receptors regulating cholesterol 7α-hydroxylase (CYP7A1), the rate-limiting enzyme in bile acid synthesis, have not yet been fully elucidated. In the present study, we report that oestrogen-related receptor γ (ERRγ) is a novel transcriptional regulator of CYP7A1 expression. Activation of cannabinoid receptor type 1 (CB1 receptor) signalling induced ERRγ-mediated transcription of the CYP7A1 gene. Overexpression of ERRγ increased CYP7A1 expression in vitro and in vivo, whereas knockdown of ERRγ attenuated CYP7A1 expression. Deletion analysis of the CYP7A1 gene promoter and a ChIP assay revealed an ERRγ-binding site on the CYP7A1 gene promoter. Small heterodimer partner (SHP) inhibited the transcriptional activity of ERRγ and thus regulated CYP7A1 expression. Overexpression of ERRγ led to increased bile acid levels, whereas an inverse agonist of ERRγ, GSK5182, reduced CYP7A1 expression and bile acid synthesis. Finally, GSK5182 significantly reduced hepatic CB1 receptor-mediated induction of CYP7A1 expression and bile acid synthesis in alcohol-treated mice. These results provide the molecular mechanism linking ERRγ and bile acid metabolism. PMID:26348907

  4. Functional Overexpression of Vomeronasal Receptors Using a Herpes Simplex Virus Type 1 (HSV-1)-Derived Amplicon.

    PubMed

    Stein, Benjamin; Alonso, María Teresa; Zufall, Frank; Leinders-Zufall, Trese; Chamero, Pablo

    2016-01-01

    In mice, social behaviors such as mating and aggression are mediated by pheromones and related chemosignals. The vomeronasal organ (VNO) detects olfactory information from other individuals by sensory neurons tuned to respond to specific chemical cues. Receptors expressed by vomeronasal neurons are implicated in selective detection of these cues. Nearly 400 receptor genes have been identified in the mouse VNO, but the tuning properties of individual receptors remain poorly understood, in part due to the lack of a robust heterologous expression system. Here we develop a herpes virus-based amplicon delivery system to overexpress three types of vomeronasal receptor genes and to characterize cell responses to their proposed ligands. Through Ca2+ imaging in native VNO cells we show that virus-induced overexpression of V1rj2, V2r1b or Fpr3 caused a pronounced increase of responsivity to sulfated steroids, MHC-binding peptide or the synthetic hexapeptide W-peptide, respectively. Other related ligands were not recognized by infected individual neurons, indicating a high degree of selectivity by the overexpressed receptor. Removal of G-protein signaling eliminates Ca2+ responses, indicating that the endogenous second messenger system is essential for observing receptor activation. Our results provide a novel expression system for vomeronasal receptors that should be useful for understanding the molecular logic of VNO ligand detection. Functional expression of vomeronasal receptors and their deorphanization provides an essential requirement for deciphering the neural mechanisms controlling behavior. PMID:27195771

  5. Functional Overexpression of Vomeronasal Receptors Using a Herpes Simplex Virus Type 1 (HSV-1)-Derived Amplicon

    PubMed Central

    Stein, Benjamin; Alonso, María Teresa; Zufall, Frank; Leinders-Zufall, Trese; Chamero, Pablo

    2016-01-01

    In mice, social behaviors such as mating and aggression are mediated by pheromones and related chemosignals. The vomeronasal organ (VNO) detects olfactory information from other individuals by sensory neurons tuned to respond to specific chemical cues. Receptors expressed by vomeronasal neurons are implicated in selective detection of these cues. Nearly 400 receptor genes have been identified in the mouse VNO, but the tuning properties of individual receptors remain poorly understood, in part due to the lack of a robust heterologous expression system. Here we develop a herpes virus-based amplicon delivery system to overexpress three types of vomeronasal receptor genes and to characterize cell responses to their proposed ligands. Through Ca2+ imaging in native VNO cells we show that virus-induced overexpression of V1rj2, V2r1b or Fpr3 caused a pronounced increase of responsivity to sulfated steroids, MHC-binding peptide or the synthetic hexapeptide W-peptide, respectively. Other related ligands were not recognized by infected individual neurons, indicating a high degree of selectivity by the overexpressed receptor. Removal of G-protein signaling eliminates Ca2+ responses, indicating that the endogenous second messenger system is essential for observing receptor activation. Our results provide a novel expression system for vomeronasal receptors that should be useful for understanding the molecular logic of VNO ligand detection. Functional expression of vomeronasal receptors and their deorphanization provides an essential requirement for deciphering the neural mechanisms controlling behavior. PMID:27195771

  6. All-Atom Structural Models of the Transmembrane Domains of Insulin and Type 1 Insulin-Like Growth Factor Receptors

    PubMed Central

    Mohammadiarani, Hossein; Vashisth, Harish

    2016-01-01

    The receptor tyrosine kinase superfamily comprises many cell-surface receptors including the insulin receptor (IR) and type 1 insulin-like growth factor receptor (IGF1R) that are constitutively homodimeric transmembrane glycoproteins. Therefore, these receptors require ligand-triggered domain rearrangements rather than receptor dimerization for activation. Specifically, binding of peptide ligands to receptor ectodomains transduces signals across the transmembrane domains for trans-autophosphorylation in cytoplasmic kinase domains. The molecular details of these processes are poorly understood in part due to the absence of structures of full-length receptors. Using MD simulations and enhanced conformational sampling algorithms, we present all-atom structural models of peptides containing 51 residues from the transmembrane and juxtamembrane regions of IR and IGF1R. In our models, the transmembrane regions of both receptors adopt helical conformations with kinks at Pro961 (IR) and Pro941 (IGF1R), but the C-terminal residues corresponding to the juxtamembrane region of each receptor adopt unfolded and flexible conformations in IR as opposed to a helix in IGF1R. We also observe that the N-terminal residues in IR form a kinked-helix sitting at the membrane–solvent interface, while homologous residues in IGF1R are unfolded and flexible. These conformational differences result in a larger tilt-angle of the membrane-embedded helix in IGF1R in comparison to IR to compensate for interactions with water molecules at the membrane–solvent interfaces. Our metastable/stable states for the transmembrane domain of IR, observed in a lipid bilayer, are consistent with a known NMR structure of this domain determined in detergent micelles, and similar states in IGF1R are consistent with a previously reported model of the dimerized transmembrane domains of IGF1R. Our all-atom structural models suggest potentially unique structural organization of kinase domains in each receptor. PMID

  7. Dopamine D(2)/D(3)-receptor and transporter densities in nucleus accumbens and amygdala of type 1 and 2 alcoholics.

    PubMed

    Tupala, E; Hall, H; Bergström, K; Särkioja, T; Räsänen, P; Mantere, T; Callaway, J; Hiltunen, J; Tiihonen, J

    2001-05-01

    Alcohol acts through mechanisms involving the brain neurotransmitter dopamine (DA) with the nucleus accumbens as the key zone for mediating these effects. We evaluated the densities of DA D(2)/D(3) receptors and transporters in the nucleus accumbens and amygdala of post-mortem human brains by using [(125)l]epidepride and [(125)I]PE2I as radioligands in whole hemispheric autoradiography of Cloninger type 1 and 2 alcoholics and healthy controls. When compared with controls, the mean binding of [(125)I]epidepride to DA D(2)/D(3) receptors was 20% lower in the nucleus accumbens and 41% lower in the amygdala, and [(125)I]PE2I binding to DA transporters in the nucleus accumbens was 39% lower in type 1 alcoholics. These data indicate that dopaminergic functions in these limbic areas may be impaired among type 1 alcoholics, due to the substantially lower number of receptor sites. Our results suggest that such a reduction may result in the chronic overuse of alcohol as an attempt to stimulate DA function. PMID:11326293

  8. Synthesis and Evaluation of Candidate PET Radioligands for Corticotropin-Releasing Factor Type-1 Receptors

    PubMed Central

    Lodge, Nicholas J.; Li, Yu-Wen; Chin, Frederick T.; Dischino, Douglas D.; Zoghbi, Sami S.; Deskus, Jeffrey A.; Mattson, Ronald J.; Imaizumo, Masao; Pieschl, Rick; Molski, Thaddeus F.; Fujita, Masahiro; Dulac, Heidi; Zaczek, Robert; Bronson, Joanne J.; Macor, John E.; Innis, Robert B.; Pike, Victor W.

    2014-01-01

    Introduction A radioligand for measuring the density of corticotrophin-releasing factor subtype-1 receptors (CRF1 receptors) in living animal and human brain with positron emission tomography (PET) would be a useful tool for neuropsychiatric investigations and the development of drugs intended to interact with this target. This study was aimed at discovery of such a radioligand from a group of CRF1 receptor ligands based on a core 3-(phenylamino)pyrazin-2(1H)-one scaffold. Methods CRF1 receptor ligands were selected for development as possible PET radioligands based on their binding potency at CRF receptors (displacement of [125I]CRF from rat cortical membranes), measured lipophilicity, autoradiographic binding profile in rat and rhesus monkey brain sections, rat biodistribution, and suitability for radiolabeling with carbon-11 or fluorine-18. Two identified candidates (BMS-721313 and BMS-732098) were labeled with fluorine-18. A third candidate (BMS-709460) was labeled with carbon-11 and all three radioligands were evaluated in PET experiments in rhesus monkey. CRF1 receptor density (Bmax) was assessed in rhesus brain cortical and cerebellum membranes with the CRF receptor ligand, [3H]BMS-728300. Results The three ligands selected for development showed high binding affinity (IC50 values, 0.3–8 nM) at CRF1 receptors and moderate lipophilicity (LogD, 2.8–4.4). [3H]BMS-728300 and the two 18F-labeled ligands showed region-specific binding in rat and rhesus monkey brain autoradiography, namely higher binding density in the frontal and limbic cortex, and cerebellum than in thalamus and brainstem. CRF1 receptor Bmax in rhesus brain was found to be 50–120 fmol/mg protein across cortical regions and cerebellum. PET experiments in rhesus monkey showed that the radioligands [18F]BMS-721313, [18F]BMS-732098 and [11C]BMS-709460 gave acceptably high brain radioactivity uptake but no indication of the specific binding as seen in vitro. Conclusions Candidate CRF1 receptor

  9. Combination of the dipeptidyl peptidase IV inhibitor LAF237 [(S)-1-[(3-hydroxy-1-adamantyl)ammo]acetyl-2-cyanopyrrolidine] with the angiotensin II type 1 receptor antagonist valsartan [N-(1-oxopentyl)-N-[[2'-(1H-tetrazol-5-yl)-[1,1'-biphenyl]-4-yl]methyl]-L-valine] enhances pancreatic islet morphology and function in a mouse model of type 2 diabetes.

    PubMed

    Cheng, Qianni; Law, Pui Ki; de Gasparo, Marc; Leung, Po Sing

    2008-12-01

    LAF237 [(S)-1-[(3-hydroxy-1-adamantyl)ammo]acetyl-2-cyanopyrrolidine] is an inhibitor of dipeptidyl peptidase IV that delays the degradation of glucagon-like peptide-1 (GLP-1). Valsartan [N-(1-oxopentyl)-N-[[2'-(1H-tetrazol-5-yl)[1,1'-biphenyl]-4-yl]methyl]-l-valine] is an antagonist of the angiotensin II type 1 receptor (AT1R) that reduces the incidence of type 2 diabetes mellitus. LAF237 and valsartan act on a common target through separate pathways to improve pancreatic islet cell function. We hypothesize that the combination of these two drugs acts in a synergistic or additive manner on islet function and structure. To test this hypothesis, we performed in vitro and in vivo studies. To measure the acute effect of the treatment, pancreatic islets of db/db mice were isolated and stimulated in vitro with glucose in the presence of valsartan (1 microM) and exendin-4 (100 nM), a GLP-1 receptor agonist. Combination treatment with valsartan and exendin-4 significantly enhanced glucose-stimulated insulin secretion from isolated islets. For studies of chronic effect, db/db mice received LAF237 (1 mg/kg/day) and/or valsartan (10 mg/kg/day). Islet cell reactive oxygen species (ROS), proliferation, apoptosis, fibrosis, beta-cell area, and glucose homeostasis were evaluated after 8 weeks of treatment, which showed that combination treatment resulted in a significant increase in pancreatic islet beta-cell area compared with monotherapy. This beneficial effect correlated with an increase in beta-cell proliferation and a decrease in ROS-induced islet apoptosis and fibrosis. These in vitro and in vivo data indicate that combination treatment with LAF237 and valsartan has significant beneficial additive effects on pancreatic beta-cell structure and function compared with their respective monotherapeutic effects. PMID:18787107

  10. Monoglyceride lipase deficiency causes desensitization of intestinal cannabinoid receptor type 1 and increased colonic μ-opioid receptor sensitivity

    PubMed Central

    Taschler, U; Eichmann, T O; Radner, F P W; Grabner, G F; Wolinski, H; Storr, M; Lass, A; Schicho, R; Zimmermann, R

    2015-01-01

    Background and Purpose Monoglyceride lipase (MGL) degrades 2-arachidonoyl glycerol (2-AG), an endogenous agonist of cannabinoid receptors (CB1/2). Because the CB1 receptor is involved in the control of gut function, we investigated the effects of pharmacological inhibition and genetic deletion of MGL on intestinal motility. Furthermore, we determined whether defective 2-AG degradation affects μ-opioid receptorreceptor) signalling, a parallel pathway regulating gut motility. Experimental Approach Gut motility was investigated by monitoring Evans Blue transit and colonic bead propulsion in response to MGL inhibition and CB1 receptor or μ receptor stimulation. Ileal contractility was investigated by electrical field stimulation. CB1 receptor expression in ileum and colon was assessed by immunohistochemical analyses. Key Results Pharmacological inhibition of MGL slowed down whole gut transit in a CB1 receptor-dependent manner. Conversely, genetic deletion of MGL did not affect gut transit despite increased 2-AG levels. Notably, MGL deficiency caused complete insensitivity to CB1 receptor agonist-mediated inhibition of whole gut transit and ileal contractility suggesting local desensitization of CB1 receptors. Accordingly, immunohistochemical analyses of myenteric ganglia of MGL-deficient mice revealed that CB1 receptors were trapped in endocytic vesicles. Finally, MGL-deficient mice displayed accelerated colonic propulsion and were hypersensitive to μ receptor agonist-mediated inhibition of colonic motility. This phenotype was reproduced by chronic pharmacological inhibition of MGL. Conclusion and Implications Constantly elevated 2-AG levels induce severe desensitization of intestinal CB1 receptors and increased sensitivity to μ receptor-mediated inhibition of colonic motility. These changes should be considered when cannabinoid-based drugs are used in the therapy of gastrointestinal diseases. PMID:26075589

  11. Vascular endothelial growth factor-induced elimination of the type 1 interferon receptor is required for efficient angiogenesis.

    PubMed

    Zheng, Hui; Qian, Juan; Carbone, Christopher J; Leu, N Adrian; Baker, Darren P; Fuchs, Serge Y

    2011-10-01

    Angiogenesis is stimulated by vascular endothelial growth factor (VEGF) and antagonized by type 1 interferons, including IFN-α/β. On engaging their respective receptors (VEGFR2 and IFNAR), both stimuli activate protein kinase D2 (PKD2) and type 1 IFNs require PKD2 activation and recruitment to IFNAR1 to promote the phosphorylation-dependent ubiquitination, down-regulation, and degradation of the cognate receptor chain, IFNAR1. Data reveal that PKD2 activity is dispensable for VEGF-stimulated down-regulation of VEGFR2. Remarkably, VEGF treatment promotes the recruitment of PKD2 to IFNAR1 as well as ensuing phosphorylation, ubiquitination, and degradation of IFNAR1. In cells exposed to VEGF, phosphorylation-dependent degradation of IFNAR1 leads to an inhibition of type 1 IFN signaling and is required for efficient VEGF-stimulated angiogenesis. Importance of this mechanism for proangiogenic or antiangiogenic responses in cells exposed to counteracting stimuli and the potential medical significance of this regulation are discussed. PMID:21832278

  12. Polymodal Transient Receptor Potential Vanilloid Type 1 Nocisensor: Structure, Modulators, and Therapeutic Applications.

    PubMed

    Cui, Minghua; Gosu, Vijayakumar; Basith, Shaherin; Hong, Sunhye; Choi, Sun

    2016-01-01

    Transient receptor potential (TRP) channels belong to a superfamily of sensory-related ion channels responding to a wide variety of thermal, mechanical, or chemical stimuli. In an attempt to comprehend the piquancy and pain mechanism of the archetypal vanilloids, transient receptor potential vanilloid (TRPV) 1 was discovered. TRPV1, a well-established member of the TRP family, is implicated in a range of functions including inflammation, painful stimuli sensation, and mechanotransduction. TRPV1 channels are nonselective cation receptors that are gated by a broad array of noxious ligands. Such polymodal-sensor aspect makes the TRPV1 channel extremely versatile and important for its role in sensing burning pain. Besides ligands, TRPV1 signaling can also be modulated by lipids, secondary messengers, protein kinases, cytoskeleton, and several other proteins. Due to its central role in hyperalgesia transduction and inflammatory processes, it is considered as the primary pharmacological pain target. Moreover, understanding the structural and functional intricacies of the channel is indispensable for the therapeutic intervention of TRPV1 in pain and other pathological disorders. In this chapter, we seek to give a mechanistic outlook on the TRPV1 channel. Specifically, we will explore the TRPV1 structure, activation, modulation, ligands, and its therapeutic targeting. However, the major objective of this review is to highlight the fact that TRPV1 channel can be treated as an effective therapeutic target for treating several pain- and nonpain-related physiological and pathological states. PMID:27038373

  13. Possible Therapeutic Doses of Cannabinoid Type 1 Receptor Antagonist Reverses Key Alterations in Fragile X Syndrome Mouse Model.

    PubMed

    Gomis-González, Maria; Matute, Carlos; Maldonado, Rafael; Mato, Susana; Ozaita, Andrés

    2016-01-01

    Fragile X syndrome (FXS) is the most common monogenetic cause of intellectual disability. The cognitive deficits in the mouse model for this disorder, the Fragile X Mental Retardation 1 (Fmr1) knockout (KO) mouse, have been restored by different pharmacological approaches, among those the blockade of cannabinoid type 1 (CB1) receptor. In this regard, our previous study showed that the CB1 receptor antagonist/inverse agonist rimonabant normalized a number of core features in the Fmr1 knockout mouse. Rimonabant was commercialized at high doses for its anti-obesity properties, and withdrawn from the market on the bases of mood-related adverse effects. In this study we show, by using electrophysiological approaches, that low dosages of rimonabant (0.1 mg/kg) manage to normalize metabotropic glutamate receptor dependent long-term depression (mGluR-LTD). In addition, low doses of rimonabant (from 0.01 mg/kg) equally normalized the cognitive deficit in the mouse model of FXS. These doses of rimonabant were from 30 to 300 times lower than those required to reduce body weight in rodents and to presumably produce adverse effects in humans. Furthermore, NESS0327, a CB1 receptor neutral antagonist, was also effective in preventing the novel object-recognition memory deficit in Fmr1 KO mice. These data further support targeting CB1 receptors as a relevant therapy for FXS. PMID:27589806

  14. The role of orexin type-1 receptors in the development of morphine tolerance in locus coeruleus neurons: An electrophysiological perspective.

    PubMed

    Abdollahi, Hakime; Ghaemi-Jandabi, Masoumeh; Azizi, Hossein; Semnanian, Saeed

    2016-09-01

    Long-term exposure to opioid agonists results in tolerance to their analgesic effects, so the effectiveness of opioid agonists in the management of pain becomes limited. The locus coeruleus (LC) nucleus has been involved in the development of tolerance to opiates. Orexin type-1 receptors (OX1Rs) are highly expressed in LC nucleus. Orexin plays a noteworthy role in the occurrence of morphine tolerance. The purpose of the present study is to investigate the role of orexin type-1 receptors in the development of morphine tolerance in LC neurons. In this study, adult male Wistar rats weighing 250-300g were utilized. Induction of morphine tolerance was obtained by single injection of morphine per day for 6 successive days. An orexin type-1 receptor antagonist (SB-334867) was injected into the lateral ventricle instantly prior to morphine injection. On day 7, the effect of morphine on the electrical activity of LC neurons was studied using in vivo extracellular single unit recording. The results demonstrate that morphine injection for 6 consecutive days led to the development of morphine-induced tolerance in LC neurons. In other words, there was a significant decrease in LC neuronal responsiveness to morphine injection. Inhibitory responses of LC neurons to intraperitoneally applied morphine can be observed with the treatment of the SB-334867 prior to morphine injection. This study showed that OX1R blockade by SB-334867 prevents the development of morphine tolerance in LC neurons. We hope that further studies will lead to considerable progress in understanding the molecular adaptations that contribute to morphine tolerance. PMID:27235867

  15. Deletion of the angiotensin II type 1 receptor–associated protein enhances renal sodium reabsorption and exacerbates angiotensin II–mediated hypertension

    PubMed Central

    Ohsawa, Masato; Tamura, Kouichi; Wakui, Hiromichi; Maeda, Akinobu; Dejima, Toru; Kanaoka, Tomohiko; Azushima, Kengo; Uneda, Kazushi; Tsurumi-Ikeya, Yuko; Kobayashi, Ryu; Matsuda, Miyuki; Uchida, Shinichi; Toya, Yoshiyuki; Kobori, Hiroyuki; Nishiyama, Akira; Yamashita, Akio; Ishikawa, Yoshihiro; Umemura, Satoshi

    2014-01-01

    Angiotensin II type 1 receptor (AT1R)–associated protein (ATRAP) promotes AT1R internalization along with suppression of pathological activation of tissue AT1R signaling. However, the functional significance of ATRAP in renal sodium handling and blood pressure regulation under pathological stimuli is not fully resolved. Here we show the blood pressure of mice with a gene-targeted disruption of ATRAP was comparable to that of wild-type mice at baseline. However, in ATRAP-knockout mice, angiotensin II–induced hypertension was exacerbated and the extent of positive sodium balance was increased by angiotensin II. Renal expression of the sodium-proton antiporter 3, a major sodium transporter in the proximal tubules, urinary pH, renal angiotensinogen production, and angiotensin II content was unaffected. Stimulation of the renal expression and activity of the epithelial sodium channel (ENaC), a major sodium transporter in the distal tubules, was significantly enhanced by chronic angiotensin II infusion. The circulating and urinary aldosterone levels were comparable. The blood pressure response and renal ENaC expression by aldosterone were not affected. Thus, ATRAP deficiency exacerbated angiotensin II–mediated hypertension by pathological activation of renal tubular AT1R by angiotensin II. This directly stimulates ENaC in the distal tubules and enhances sodium retention in an aldosterone-independent manner. PMID:24694992

  16. Molecular interactions of the type 1 human immunodeficiency virus transregulatory protein Tat with N-methyl-d-aspartate receptor subunits.

    PubMed

    Chandra, T; Maier, W; König, H-G; Hirzel, K; Kögel, D; Schüler, T; Chandra, A; Demirhan, I; Laube, B

    2005-01-01

    We investigated the effect of type 1 human immunodeficiency virus (HIV-1) regulatory protein Tat on N-methyl-d-aspartate (NMDA) receptors expressed in Xenopus oocytes by voltage-clamp recording and its role in NMDA-mediated neurotoxicity using cultured rat hippocampal neurons. Tat (0.01-1muM) potentiated NMDA-induced currents of recombinant NMDA receptors. However, in the presence of Zn(2+), the potentiating effect of Tat was much more pronounced, indicating an additional Zn(2+)-related effect on NMDA receptors. Consistently, Tat potentiated currents of the particularly Zn(2+)-sensitive NR1/NR2A NMDA receptor with a higher efficacy, whereas currents from a Zn(2+)-insensitive mutant were only marginally augmented. In addition, chemical-modified Tat, deficient for metal binding, did not reverse Zn(2+)-mediated inhibition of NMDA responses, demonstrating that Tat disinhibits NMDA receptors from Zn(2+)-mediated antagonism by complexing the cation. We therefore investigated the interplay of Tat and Zn(2+) in NMDA-mediated neurotoxicity using cultures of rat hippocampal neurons. Zn(2+) exhibited a prominent rescuing effect when added together with the excitotoxicant NMDA, which could be reverted by the Zn(2+)-chelator tricine. Similar to tricine, Tat enhanced NMDA-mediated neurotoxicity in the presence of neuroprotective Zn(2+) concentrations. Double-staining with antibodies against Tat and the NR1 subunit of the NMDA receptor revealed partial colocalization of the immunoreactivities in membrane patches of hippocampal neurons, supporting the idea of a direct interplay between Tat and glutamatergic transmission. We therefore propose that release of Zn(2+)-mediated inhibition of NMDA receptors by HIV-1 Tat contributes to the neurotoxic effect of glutamate and may participate in the pathogenesis of AIDS-associated dementia. PMID:15964699

  17. Histamine impairs midbrain dopaminergic development in vivo by activating histamine type 1 receptors

    PubMed Central

    2014-01-01

    Background Histamine (HA) regulates the sleep-wake cycle, synaptic plasticity and memory in adult mammals. Dopaminergic specification in the embryonic ventral midbrain (VM) coincides with increased HA brain levels. To study the effect of HA receptor stimulation on dopamine neuron generation, we administered HA to dopamine progenitors, both in vitro and in vivo. Results Cultured embryonic day 12 (E12) VM neural stem/progenitor cells expressed transcripts for HA receptors H1R, H2R and H3R. These undifferentiated progenitors increased intracellular calcium upon HA addition. In HA-treated cultures, dopamine neurons significantly decreased after activation of H1R. We performed intrauterine injections in the developing VM to investigate HA effects in vivo. HA administration to E12 rat embryos notably reduced VM Tyrosine Hydroxylase (TH) staining 2 days later, without affecting GABA neurons in the midbrain, or serotonin neurons in the mid-hindbrain boundary. qRT-PCR and Western blot analyses confirmed that several markers important for the generation and maintenance of dopaminergic lineage such as TH, Lmx1a and Lmx1b were significantly diminished. To identify the cell type susceptible to HA action, we injected embryos of different developmental stages, and found that neural progenitors (E10 and E12) were responsive, whereas differentiated dopaminergic neurons (E14 and E16) were not susceptible to HA actions. Proliferation was significantly diminished, whereas neuronal death was not increased in the VM after HA administration. We injected H1R or H2R antagonists to identify the receptor responsible for the detrimental effect of HA on dopaminergic lineage and found that activation of H1R was required. Conclusion These results reveal a novel action of HA affecting dopaminergic lineage during VM development. PMID:25112718

  18. Absence of NMDA receptor antibodies in the rare association between Type 1 Narcolepsy and Psychosis.

    PubMed

    Dauvilliers, Y; Gaig, C; Barateau, L; Graus, F; Iranzo, A; Lopez, R; Santamaria, J

    2016-01-01

    Frequency and mechanisms underlying the association between narcolepsy type 1 (NT1) and psychosis remain unclear with potential role for a common immune pathway. We estimated the frequency of psychosis and its characteristics in NT1 at two European sleep centers (France, n = 381; Spain, n = 161) and measured IgG autoantibodies that recognize the GluN1 subunit of the NMDAR in 9 patients with NT1 with psychosis, and 25 NT1 patients without psychosis. Ten NT1 patients (6 in France, 4 in Spain) were diagnosed with comorbid psychosis, a frequency of 1.8%. One patient reported psychotic symptoms few months before narcolepsy onset, two patients few months after onset, and one patient one year after onset but after modafinil introduction. The six remaining patients reported long delays between NT1 and psychosis onset. Half the patients, mostly male adults, reported onset or worsening of psychotic symptoms after medication. We found no IgG antibodies to NR1/NR2B heteromers of the NMDARs in patients with NT1 with or without psychosis. To conclude, psychosis is rare in NT1, with limited evidence for a key impact of stimulants, and no association with anti-NMDAR antibodies. However, dramatic NT1 and schizophrenia exists especially in early onset NT1, which may lead to inappropriate diagnosis and management. PMID:27143278

  19. Cysteine dioxygenase type 1 promotes adipogenesis via interaction with peroxisome proliferator-activated receptor gamma

    SciTech Connect

    Deng, Peng; Chen, Yi; Ji, Ning; Lin, Yunfeng; Yuan, Quan; Ye, Ling; Chen, Qianming

    2015-02-27

    Mammalian cysteine dioxygenase type 1 (CDO1) is an essential enzyme for taurine biosynthesis and the biodegradation of toxic cysteine. As previously suggested, Cdo1 may be a marker of liposarcoma progression and adipogenic differentiation, but the role of Cdo1 in adipogenesis has yet been reported. In this study, we found that the expression of Cdo1 is dramatically elevated during adipogenic differentiation of 3T3-L1 pre-adipocytes and mouse bone marrow-derived mesenchymal stem cells (mBMSCs). Conversely, knockdown of Cdo1 inhibited expression of adipogenic specific genes and lipid droplet formation in 3T3-L1 cells and mBMSCs. Mechanistically, we found Cdo1 interacted with Pparγ in response to adipogenic stimulus. Further, depletion of Cdo1 reduced the recruitment of Pparγ to the promoters of C/EBPα and Fabp4. Collectively, our finding indicates that Cdo1 may be a co-activator of Pparγ in adipogenesis, and may contribute to the development of disease associated with excessive adipose tissue. - Highlights: • Cdo1expression is highly up-regulated during adipogenic differentiation of 3T3-L1 and mBMSCs. • Depletion of Cdo1 inhibited expression of adipogenic specific genes and lipid droplet formation. • Cdo1interacts with Pparγ during adipogenesis. • Knockdown of Cdo1 inhibited Pparγ binding to the promoters of C/EBPα and Fabp4.

  20. Absence of NMDA receptor antibodies in the rare association between Type 1 Narcolepsy and Psychosis

    PubMed Central

    Dauvilliers, Y.; Gaig, C.; Barateau, L.; Graus, F.; Iranzo, A.; Lopez, R.; Santamaria, J.

    2016-01-01

    Frequency and mechanisms underlying the association between narcolepsy type 1 (NT1) and psychosis remain unclear with potential role for a common immune pathway. We estimated the frequency of psychosis and its characteristics in NT1 at two European sleep centers (France, n = 381; Spain, n = 161) and measured IgG autoantibodies that recognize the GluN1 subunit of the NMDAR in 9 patients with NT1 with psychosis, and 25 NT1 patients without psychosis. Ten NT1 patients (6 in France, 4 in Spain) were diagnosed with comorbid psychosis, a frequency of 1.8%. One patient reported psychotic symptoms few months before narcolepsy onset, two patients few months after onset, and one patient one year after onset but after modafinil introduction. The six remaining patients reported long delays between NT1 and psychosis onset. Half the patients, mostly male adults, reported onset or worsening of psychotic symptoms after medication. We found no IgG antibodies to NR1/NR2B heteromers of the NMDARs in patients with NT1 with or without psychosis. To conclude, psychosis is rare in NT1, with limited evidence for a key impact of stimulants, and no association with anti-NMDAR antibodies. However, dramatic NT1 and schizophrenia exists especially in early onset NT1, which may lead to inappropriate diagnosis and management. PMID:27143278

  1. Generation and Characterization of Mice Expressing a Conditional Allele of the Interleukin-1 Receptor Type 1

    PubMed Central

    Robson, Matthew J.; Zhu, Chong-Bin; Quinlan, Meagan A.; Botschner, David A.; Baganz, Nicole L.; Lindler, Kathryn M.; Thome, Jason G.; Hewlett, William A.; Blakely, Randy D.

    2016-01-01

    The cytokines IL-1α and IL-1β exert powerful pro-inflammatory actions throughout the body, mediated primarily by the intracellular signaling capacity of the interleukin-1 receptor (IL-1R1). Although Il1r1 knockout mice have been informative with respect to a requirement for IL-1R1 signaling in inflammatory events, the constitutive nature of gene elimination has limited their utility in the assessment of temporal and spatial patterns of cytokine action. To pursue such questions, we have generated C57Bl/6J mice containing a floxed Il1r1 gene (Il1r1loxP/loxP), with loxP sites positioned to flank exons 3 and 4 and thereby the ability to spatially and temporally eliminate Il1r1 expression and signaling. We found that Il1r1loxP/loxP mice breed normally and exhibit no gross physical or behavioral phenotypes. Moreover, Il1r1loxP/loxP mice exhibit normal IL-1R1 receptor expression in brain and spleen, as well as normal IL-1R1-dependent increases in serum IL-6 following IL-1α injections. Breeding of Il1r1loxP/loxP mice to animals expressing a cytomegalovirus (CMV)-driven Cre recombinase afforded efficient excision at the Il1r1 locus. The Il1r1loxP/loxP line should be a valuable tool for the assessment of contributions made by IL-1R1 signaling in diverse cell types across development. PMID:26930558

  2. Leukotriene E4 is a full functional agonist for human cysteinyl leukotriene type 1 receptor-dependent gene expression

    PubMed Central

    Foster, Holly R.; Fuerst, Elisabeth; Branchett, William; Lee, Tak H.; Cousins, David J.; Woszczek, Grzegorz

    2016-01-01

    Leukotriene E4 (LTE4) the most stable of the cysteinyl leukotrienes (cysLTs) binds poorly to classical type 1 (CysLT1) and 2 (CysLT2) receptors although it induces potent responses in human airways in vivo, such as bronchoconstriction, airway hyperresponsiveness and inflammatory cell influx suggesting the presence of a novel receptor that preferentially responds to LTE4. To identify such a receptor two human mast cell lines, LAD2 and LUVA, were selected that differentially responded to LTE4 when analysed by intracellular signalling and gene expression. Comparative transcriptome analysis and recombinant gene overexpression experiments revealed CysLT1 as a receptor responsible for potent LTE4-induced response in LAD2 but not in LUVA cells, an observation confirmed further by gene knockdown and selective inhibitors. Lentiviral overexpression of CysLT1 in LUVA cells augmented intracellular calcium signalling induced by LTE4 but did not restore full agonist responses at the gene expression level. Our data support a model where both an increased expression of Gαq-coupled CysLT1, and sustained intracellular calcium mobilisation and extracellular signal-regulated kinase (Erk) activation, are required for LTE4-mediated regulation of gene expression in human cells. Our study shows for the first time that CysLT1 expression is critically important for responsiveness to LTE4 within a human cell system. PMID:26830450

  3. Differential effects of selective lesions of cholinergic and dopaminergic neurons on serotonin-type 1 receptors in rat brain

    SciTech Connect

    Quirion, R.; Richard, J.

    1987-01-01

    Serotonin (5-HT)-type1 receptor binding sites are discretely distributed in rat brain. High densities of (3H)5-HT1 binding sites are especially located in areas enriched with cholinergic and dopaminergic innervation, such as the substantia innominata/ventral pallidum, striatum, septal nuclei, hippocampus and substantia nigra. The possible association of (3H)5-HT1 binding sites with cholinergic or dopaminergic cell bodies and/or nerve fiber terminals was investigated by selective lesions of the substantia innominata/ventral pallidum-cortical and septohippocampal cholinergic pathways and the nigrostriatal dopaminergic projection. (3H)5-HT1 receptor binding sites are possibly located on cholinergic cell bodies in the ventral pallidum-cortical pathway since (3H)5-HT1 binding in the substantia innominata/ventral pallidal area was markedly decreased following kainic acid lesions. Fimbriaectomies markedly decreased (3H)5-HT1 binding in the hippocampus, suggesting the presence of 5-HT1 binding sites on cholinergic nerve fiber terminals in the septohippocampal pathway. Lesions of the nigrostriatal dopaminergic projection did not modify (3H)5-HT1 binding in the substantia nigra and the striatum, suggesting that 5-HT1 receptors are not closely associated with dopaminergic cell bodies and nerve terminals in this pathway. These results demonstrate differential association between 5-HT1 receptors and cholinergic and dopaminergic innervation in rat brain.

  4. Prevalence of vitamin D receptor gene polymorphism in a Uruguayan population and its relation to type 1 diabetes mellitus.

    PubMed

    Mimbacas, A; Trujillo, J; Gascue, C; Javiel, G; Cardoso, H

    2007-01-01

    Vitamin D has important immuno-modulatory properties and it influences insulin secretion. It acts through a vitamin D receptor (VDR), for which several gene polymorphisms have been described. The Uruguayan population presents several epidemiological characteristics that make it different from that of other counties, including other Latin-American countries. It went through miscegenation processes, with a tri-hybrid European, Amerindian and African origin, with no contribution from isolated Amerindian communities. Such differences have important consequences for the relationship between frequencies of several genes in the general population and their association with the diabetes mellitus. We examined the prevalence of VDR gene polymorphisms in the general population and their relation to type 1 diabetes in a parent-case design. One hundred unrelated individuals from the general population and 45 parent-patient triads with a child affected with type 1 diabetes were genotyped for FokI, BsmI and TaqI VDR gene polymorphisms by RFLP-PCR. We used a transmission disequilibrium test to assess preferential transmission of parents to affected offspring. The prevalence of the three VDR polymorphisms was: allele F = 48%, B = 35%, T = 64%. The f, b, T alleles and heterozygous genotypes were found at a high frequency in this population. Among 36 informative heterozygous parental genotypes, 30 transmitted the F allele (probability of transmission = 83%). The other two polymorphisms did not show significant transmission. We suggest that FokI polymorphism indicates susceptibility to type 1 diabetes mellitus in the Uruguayan population. PMID:17985306

  5. Long-Range Communication Network in the Type 1B Bone Morphogenetic Protein Receptor.

    PubMed

    Evangelista, Wilfredo; Yeh, Lee-Chuan C; Gmyrek, Aleksandra; Lee, J Ching; Lee, John C

    2015-12-01

    Protein-protein interactions are recognized as a fundamental phenomenon that is intimately associated with biological functions and thus are ideal targets for developing modulators for regulating biological functions. A challenge is to identify a site that is situated away from but functionally connected to the protein-protein interface. We employed bone morphogenetic proteins (BMPs) and their receptors as a model system to develop a strategy for identifying such a network of communication. Accordingly, using computational analyses with the COREX/BEST algorithm, we uncovered an overall pattern connecting various regions of BMPR-1B ectodomain, including the four conserved residues in the protein-protein interface. In preparation for testing the long-range effects of mutations of distal residues for future studies, we examined the extent of measurable perturbation of the four conserved residues by determination of the conformation and relative affinities of these BMPR-1B mutants for ligands BMP-2, -6, and -7 and GDF-5. Results suggest no significant structural changes in the receptor but do suggest that the four residues play different roles in defining ligand affinity and both intra- and intermolecular interactions play a role in defining ligand affinity. Thus, these results established two primary but necessary goals: (1) the baseline knowledge of perturbation of conserved interfacial residues for future reference and (2) the ability of the computational approach to identify the distal residues connecting to the interfacial residues. The data presented here provide the foundation for future experiments to identify the effects of distal residues that affect the specificity and affinity of BMP recognition. Protein-protein interactions are integral reactions in essentially all biological activities such as gene regulation and age-related development. Often, diseases are consequences of the alteration of these intermacromolecular interactions, which are thus recognized

  6. Cultured rat calvarial osteoblast-like cells are provided with orexin type 1 receptors.

    PubMed

    Ziolkowska, Agnieszka; Rucinski, Marcin; Tortorella, Cinzia; Tyczewska, Marianna; Nussdorfer, Gastone G; Malendowicz, Ludwik K

    2007-12-01

    Orexins A and B are hypothalamic peptides which are derived from the proteolytic cleavage of prepro-orexin and act via two subtypes of receptors, named OX1-R (that almost exclusively binds orexin-A) and OX2-R (nonselective for both orexins). Several lines of evidence show that other neuropeptides, which like orexins are involved in the central control of energy homeostasis (e.g. leptin and ghrelin), may play a role in the regulation of bone metabolism, acting via autocrine-paracrine or endocrine routes. Therefore, we studied by reverse transcription-polymerase chain reaction (RT-PCR) the expression of the orexin system in rat calvarial osteoblast-like (ROB) cells, whose osteoblastic lineage was immunocytochemically demonstrated by their osteonectin and collagen-1alpha content at day 14 of culture. Conventional PCR detected the mRNA expression of OX1-R, but not OX2-R and prepro-orexin in ROB cells at days 2, 7 and 21 of culture. Semiquantitative real time-PCR evidenced a gradual down-regulation of OX1-R mRNA in relation to the duration of culture. This novel finding suggests that rat osteoblasts could be a target for circulating orexin-A, especially during their early stages of differentiation into mature osteoblasts. PMID:17982683

  7. CRF type 1 receptors in the dorsal periaqueductal gray modulate anxiety-induced defensive behaviors.

    PubMed

    Litvin, Yoav; Pentkowski, Nathan S; Blanchard, D Caroline; Blanchard, Robert J

    2007-08-01

    The dorsal periaqueductal gray (dPAG) is involved in defensive coping reactions to threatening stimuli. Corticotropin releasing factor (CRF) is substantially implicated as a direct modulator of physiological, endocrine and behavioral responses to a stressor. Previous findings demonstrate a direct role of the central CRF system in dPAG-mediated defensive reactions toward a threatening stimulus. These include anxiogenic behaviors in the elevated plus maze (EPM) in rats and defensive reactions in both the mouse defense test battery (MDTB) and rat exposure test (RET) paradigms in mice. Furthermore, CRF was shown to directly and dose-dependently excite PAG neurons in vitro. The aim of the present series of experiments was to directly evaluate the role of the CRF1 receptor (CRF1) in dPAG-induced defensive behaviors in the MDTB and the RET paradigms. For this purpose, cortagine, a novel CRF1-selective agonist, was directly infused into the dPAG. In the RET the high dose of cortagine (100 ng) significantly affected spatial avoidance measures and robustly increased burying behavior, an established avoidance activity, while having no effects on behaviors in the MDTB. Collectively, these results implicate CRF1 in the dPAG as a mediator of temporally and spatially dependent avoidance in response to controllable and constant stimuli. PMID:17540371

  8. Opposite control of frontocortical 2-arachidonoylglycerol turnover rate by cannabinoid type-1 receptors located on glutamatergic neurons and on astrocytes.

    PubMed

    Belluomo, Ilaria; Matias, Isabelle; Pernègre, Camille; Marsicano, Giovanni; Chaouloff, Francis

    2015-04-01

    This study examined the respective influences of cannabinoid type-1 (CB1) receptors expressed either in forebrain GABAergic neurons, in cortical glutamatergic neurons, or in astrocytes on the turnover rates of the endocannabinoids N-arachidonoylethanolamide (AEA) and 2-arachidonoylglycerol (2-AG), and the non-cannabinoid N-acylethanolamides, palmitoylethanolamide (PEA), and oleoylethanolamide (OEA), in mouse forebrain regions. To this end, conditional mutant mice lacking CB1 receptors from either of these cell types were pre-treated systemically with JZL195, a dual inhibitor of fatty acid amide hydrolase, the enzyme degrading AEA, PEA, and OEA, and of monoacylglycerol lipase, the main 2-AG-degrading enzyme. The analyses of frontocortical, hippocampal, and striatal AEA, 2-AG, PEA, and OEA concentrations revealed that their respective baseline concentrations were not influenced by the mouse genotype. On the other hand, the accumulation of frontocortical and/or hippocampal 2-AG levels in JZL195-pre-treated mice was dependent on the mouse genotype. Thus, JZL195-induced 2-AG accumulation rates were diminished in the frontal cortex of mice lacking CB1 receptors in glutamatergic neurons while their respective values were increased in the frontal cortex and hippocampus of mice lacking these receptors in astrocytes. These genotypic differences occurred with parallel and proportionate changes in the fractional rate constants for degradation of 2-AG, thus providing a mechanism whereby the baseline levels of 2-AG remained constant between genotypes. Besides suggesting a cell-type-specific control of frontocortical and/or hippocampal 2-AG synthesis and degradation rates by CB1 receptors, this study highlights the interest of assessing endocannabinoid turnover rates when questioning the status of the endocannabinoid system. PMID:25626460

  9. CCDI: a new ligand that modulates mammalian type 1 ryanodine receptor (RyR1)

    PubMed Central

    Tian, Chengju; Shao, Chun Hong; Padanilam, Christina; Ezell, Edward; Singh, Jaipaul; Kutty, Shelby; Bidasee, Keshore R

    2014-01-01

    Background and Purpose Ryanodine receptors (RyRs) are Ca2+-release channels on the sarco(endo)plasmic reticulum that modulate a wide array of physiological functions. Three RyR isoforms are present in cells: RyR1, RyR2 and RyR3. To date, there are no reports on ligands that modulate RyR in an isoform-selective manner. Such ligands are not only valuable research tools, but could serve as intermediates for development of therapeutics. Experimental approach Pyrrole-2-carboxylic acid and 1,3-dicyclohexylcarbodiimide were allowed to react in carbon tetrachloride for 24 h at low temperatures and pressures. The chemical structures of the two products isolated were elucidated using NMR spectrometry, mass spectrometry and elemental analyses. [3H]-ryanodine binding, lipid bilayer and time-lapsed confocal imaging were used to determine their effects on RyR isoforms. Key results The major product, 2-cyclohexyl-3-cyclohexylimino-2, 3, dihydro–pyrrolo[1,2-c]imidazol-1-one (CCDI) dose-dependently potentiated Ca2+-dependent binding of [3H]-ryanodine to RyR1, with no significant effects on [3H]-ryanodine binding to RyR2 or RyR3. CCDI also reversibly increased the open probability (Po) of RyR1 with minimal effects on RyR2 and RyR3. CCDI induced Ca2+ transients in C2C12 skeletal myotubes, but not in rat ventricular myocytes. This effect was blocked by pretreating cells with ryanodine. The minor product 2-cyclohexyl-pyrrolo[1,2-c]imidazole-1,3-dione had no effect on either [3H]-ryanodine binding or Po of RyR1, RyR2 and RyR3. Conclusions and implications A new ligand that preferentially modulates RyR1 was identified. In addition to being an important research tool, the pharmacophore of this small molecule could serve as a template for the synthesis of other isoform-selective modulators of RyRs. PMID:24819467

  10. Peroxisome proliferator-activated receptor ɣ activation induces 11β-hydroxysteroid dehydrogenase type 1 activity in human alternative macrophages

    PubMed Central

    Chinetti-Gbaguidi, Giulia; Bouhlel, Mohamed Amine; Copin, Corinne; Duhem, Christian; Derudas, Bruno; Neve, Bernardette; Noel, Benoit; Eeckhoute, Jerome; Lefebvre, Philippe; Seckl, Jonathan R.; Staels, Bart

    2012-01-01

    Objectives 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) catalyses the intracellular reduction of inactive cortisone to active cortisol, the natural ligand activating the glucocorticoid receptor (GR). Peroxisome Proliferator-Activated Receptor gamma (PPARγ) is a nuclear receptor controlling inflammation, lipid metabolism and the macrophage polarization state. In this study, we investigated the impact of macrophage polarization on the expression and activity of 11β-HSD1 and the role of PPAR therein. Methods and Results 11β-HSD1 gene expression is higher in pro-inflammatory M1 and anti-inflammatory M2 macrophages than in resting macrophages (RM), whereas its activity is highest in M2 macrophages. Interestingly, PPARγ activation induces 11β-HSD1 enzyme activity in M2 macrophages, but not in RM or M1 macrophages. Consequently, human M2 macrophages displayed enhanced responsiveness to the 11β-HSD1 substrate cortisone, an effect amplified by PPAR -induction of 11β-HSD1 activity, as illustrated by an increased expression of GR target genes. Conclusions Our data identify a positive cross-talk between PPARγ and GR in human M2 macrophages via the induction of 11β-HSD1 expression and activity. PMID:22207732

  11. Crystal Structure of the Ligand Binding Suppressor Domain of Type 1 Inositol 1,4,5-Trisphosphate Receptor

    SciTech Connect

    Bosanac, Ivan; Yamazaki, Haruka; Matsu-ura, Toru; Michikawa, Takayuki; Mikoshiba, Katsuhiko; Ikura, Mitsuhiko

    2010-11-10

    Binding of inositol 1,4,5-trisphosphate (IP{sub 3}) to the amino-terminal region of IP{sub 3} receptor promotes Ca{sup 2+} release from the endoplasmic reticulum. Within the amino terminus, the first 220 residues directly preceding the IP{sub 3} binding core domain play a key role in IP{sub 3} binding suppression and regulatory protein interaction. Here we present a crystal structure of the suppressor domain of the mouse type 1 IP{sub 3} receptor at 1.8 {angstrom}. Displaying a shape akin to a hammer, the suppressor region contains a Head subdomain forming the {beta}-trefoil fold and an Arm subdomain possessing a helix-turn-helix structure. The conserved region on the Head subdomain appeared to interact with the IP{sub 3} binding core domain and is in close proximity to the previously proposed binding sites of Homer, RACK1, calmodulin, and CaBP1. The present study sheds light onto the mechanism underlying the receptor's sensitivity to the ligand and its communication with cellular signaling proteins.

  12. Copper(II) Ions Increase Plasminogen Activator Inhibitor Type 1 Dynamics in Key Structural Regions That Govern Stability.

    PubMed

    Bucci, Joel C; Trelle, Morten Beck; McClintock, Carlee S; Qureshi, Tihami; Jørgensen, Thomas J D; Peterson, Cynthia B

    2016-08-01

    Plasminogen activator inhibitor type 1 (PAI-1) regulates the fibrinolysis pathway by inhibiting the protease activity of plasminogen activators. PAI-1 works in concert with vitronectin (VN), an extracellular protein that aids in localization of active PAI-1 to tissues. The Peterson laboratory demonstrated that Cu(II) and other transition metals modulate the stability of PAI-1, exhibiting effects that are dependent on the presence or absence of the somatomedin B (SMB) domain of VN. The study presented here dissects the changes in molecular dynamics underlying the destabilizing effects of Cu(II) on PAI-1. We utilize backbone amide hydrogen/deuterium exchange monitored by mass spectrometry to assess PAI-1 dynamics in the presence and absence of Cu(II) ions with and without the SMB domain of VN. We show that Cu(II) produces an increase in dynamics in regions important for the function and overall stability of PAI-1, while the SMB domain elicits virtually the opposite effect. A mutant form of PAI-1 lacking two N-terminal histidine residues at positions 2 and 3 exhibits similar increases in dynamics upon Cu(II) binding compared to that of active wild-type PAI-1, indicating that the observed structural effects are not a result of coordination of Cu(II) to these histidine residues. Finally, addition of Cu(II) results in an acceleration of the local unfolding kinetics of PAI-1 presumed to be on pathway to the latency conversion. The effect of ligands on the dynamics of PAI-1 adds another intriguing dimension to the mechanisms for regulation of PAI-1 stability and function. PMID:27416303

  13. Angiotensin type 1a receptors in the forebrain subfornical organ facilitate leptin-induced weight loss through brown adipose tissue thermogenesis

    PubMed Central

    Young, Colin N.; Morgan, Donald A.; Butler, Scott D.; Rahmouni, Kamal; Gurley, Susan B.; Coffman, Thomas M.; Mark, Allyn L.; Davisson, Robin L.

    2015-01-01

    Objective Elevations in brain angiotensin-II cause increased energy expenditure and a lean phenotype. Interestingly, the metabolic effects of increased brain angiotensin-II mimic the actions of leptin, suggesting an interaction between the two systems. Here we demonstrate that angiotensin-type 1a receptors (AT1aR) in the subfornical organ (SFO), a forebrain structure emerging as an integrative metabolic center, play a key role in the body weight-reducing effects of leptin via brown adipose tissue (BAT) thermogenesis. Methods Cre/LoxP technology coupled with targeted viral delivery to the SFO in a mouse line bearing a conditional allele of the Agtr1a gene was utilized to determine the interaction between leptin and SFO AT1aR in metabolic regulation. Results Selective deletion of AT1aR in the SFO attenuated leptin-induced weight loss independent of changes in food intake or locomotor activity. This was associated with diminished leptin-induced increases in core body temperature, blunted upregulation of BAT thermogenic markers, and abolishment of leptin-mediated sympathetic activation to BAT. Conclusions These data identify a novel interaction between angiotensin-II and leptin in the control of BAT thermogenesis and body weight, and highlight a previously unrecognized role for the forebrain SFO in metabolic regulation. PMID:25830096

  14. Acute upregulation of neuronal mitochondrial type-1 cannabinoid receptor and it's role in metabolic defects and neuronal apoptosis after TBI.

    PubMed

    Xu, Zhen; Lv, Xiao-Ai; Dai, Qun; Ge, Yu-Qing; Xu, Jie

    2016-01-01

    Metabolic defects and neuronal apoptosis initiated by traumatic brain injury (TBI) contribute to subsequent neurodegeneration. They are all regulated by mechanisms centered around mitochondrion. Type-1 cannabinoid receptor (CB1) is a G-protein coupled receptor (GPCR) enriched on neuronal plasma membrane. Recent evidences point to the substantial presence of CB1 receptors on neuronal mitochondrial outer membranes (mtCB1) and the activation of mtCB1 influences aerobic respiration via inhibiting mitochondrial cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA)/complex I pathway. The expression and role of neuronal mtCB1 under TBI are unknown. Using TBI models of cultured neurons, wild type and CB1 knockout mice, we found mtCB1 quickly upregulated after TBI. Activation of mtCB1 promoted metabolic defects accompanied with ATP shortage but protected neurons from apoptosis. Selective activation of plasma membrane CB1 showed no effects on neuronal metabolism and apoptosis. Activation of mtCB1 receptors inhibited mitochondrial cAMP/PKA/complex I and resulted in exacerbated metabolic defects accompanied with a higher ratio of ATP reduction to oxygen consumption decrease as well as neuronal apoptosis. Further research found the remarkable accumulation of protein kinase B (AKT) on neuronal mitochondria following TBI and the activation of mtCB1 upregulated mitochondrial AKT/complex V activity. Upregulation of mitochondrial AKT/complex V activity showed anti-apoptosis effects and alleviated ATP shortage in metabolic defects. Taken together, we have identified mtCB1 quickly upregulate after TBI and a dual role the mtCB1 might play in metabolic defects and neuronal apoptosis initiated by TBI: the inhibition of mitochondrial cAMP/PKA/complex I aggravates metabolic defects, energy insufficiency as well as neuronal apoptosis, but the coactivation of mitochondrial AKT/complex V mitigates energy insufficiency and neuronal apoptosis. PMID:27485212

  15. Antibodies to cannabinoid type 1 receptor co-react with stomatin-like protein 2 in mouse brain mitochondria.

    PubMed

    Morozov, Yury M; Dominguez, Martin H; Varela, Luis; Shanabrough, Marya; Koch, Marco; Horvath, Tamas L; Rakic, Pasko

    2013-08-01

    Anti-cannabinoid type 1 receptor (CB1 ) polyclonal antibodies are widely used to detect the presence of CB1 in a variety of brain cells and their organelles, including neuronal mitochondria. Surprisingly, we found that anti-CB1 sera, in parallel with CB1 , also recognize the mitochondrial protein stomatin-like protein 2. In addition, we show that the previously reported effect of synthetic cannabinoid WIN 55,212-2 on mitochondrial complex III respiration is not detectable in purified mitochondrial preparations. Thus, our study indicates that a direct relationship between endocannabinoid signaling and mitochondrial functions in the cerebral cortex seems unlikely, and that caution should be taken interpreting findings obtained using anti-CB1 antibodies. PMID:23617247

  16. Lesions in two Escherichia coli type 1 pilus genes alter pilus number and length without affecting receptor binding.

    PubMed Central

    Russell, P W; Orndorff, P E

    1992-01-01

    We describe the characterization of two genes, fimF and fimG (also called pilD), that encode two minor components of type 1 pili in Escherichia coli. Defined, in-frame deletion mutations were generated in vitro in each of these two genes. A double mutation that had deletions identical to both single lesions was also constructed. Examination of minicell transcription and translation products of parental and mutant plasmids revealed that, as predicted from the nucleotide sequence and previous reports, the fimF gene product was a protein of ca. 16 kDa and that the fimG gene product was a protein of ca. 14 kDa. Each of the constructions was introduced, via homologous recombination, into the E. coli chromosome. All three of the resulting mutants produced type 1 pili and exhibited hemagglutination of guinea pig erythrocytes. The latter property was also exhibited by partially purified pili isolated from each of the mutants. Electron microscopic examination revealed that the fimF mutant had markedly reduced numbers of pili per cell, whereas the fimG mutant had very long pili. The double mutant displayed the characteristics of both single mutants. However, pili in the double mutant were even longer than those seen in the fimG mutant, and the numbers of pili were even fewer than those displayed by the fimF mutant. All three mutants could be complemented in trans with a single-copy-number plasmid bearing the appropriate parental gene or genes to give near-normal parental piliation. On the basis of the phenotypes exhibited by the single and double mutants, we believe that the fimF gene product may aid in initiating pilus assembly and that the fimG product may act as an inhibitor of pilus polymerization. In contrast to previous studies, we found that neither gene product was required for type 1 pilus receptor binding. Images PMID:1355769

  17. Simultaneous determination of multiple angiotensin type 1 receptor antagonists and its application to high-throughput pharmacokinetic study

    NASA Astrophysics Data System (ADS)

    Zhu, Xiaoyan; Sun, Jianguo; Hao, Haiping; Wang, Guangji; Hu, Xiaoling; Lv, Hua; Gu, Shenghua; Wu, Xiaoming; Xu, Jinyi

    2008-05-01

    A rapid and sensitive high performance liquid chromatography-electrospray tandem mass spectrometry (HPLC-ESI-MS/MS) detection was developed for the simultaneous determination of multiple angiotensin type 1 receptor antagonists (AT1RAs) WX472, WX581, 1b and telmisartan in rat plasma for the purpose of high-throughout pharmacokinetic screening. The method was operated under selected reaction monitoring (SRM) mode in the positive ion mode. The analytes and the internal standard (pitavastatin) were extracted from 100 [mu]L rat plasma under acidic conditions by liquid-liquid extraction with ethyl acetate. The analytes and internal standard were baseline separated on a Gemini analytical column (3 [mu]m, 150 mm × 2.0 mm) with the adoption of a gradient elution using acetonitrile and 0.05% aqueous formic acid. The standard curves were linear in the concentration ranges of 4.5-900 ng/mL for WX472, 5-1000 ng/mL for WX581 and 0.5-100 ng/mL for 1b and telmisartan. Intra- and inter-batch precisions (R.S.D.%) were all within 15% and the method assessed a quite good accuracy (R.E.%). Recoveries were found to be >65% for all the compounds and no obvious matrix effects were found. This method has been successfully applied to the high-throughput pharmacokinetic screening study for both cassette dosing and cassette analysis of four compounds to rats. Significant drug-drug interactions were observed after cassette dosing. The study suggested that cassette analysis of pooled samples would be a better choice for the high-throughput pharmacokinetic screening of angiotensin type 1 receptor antagonists.

  18. Monomeric ß-amyloid interacts with type-1 insulin-like growth factor receptors to provide energy supply to neurons

    PubMed Central

    Giuffrida, Maria L.; Tomasello, Marianna F.; Pandini, Giuseppe; Caraci, Filippo; Battaglia, Giuseppe; Busceti, Carla; Di Pietro, Paola; Pappalardo, Giuseppe; Attanasio, Francesco; Chiechio, Santina; Bagnoli, Silvia; Nacmias, Benedetta; Sorbi, Sandro; Vigneri, Riccardo; Rizzarelli, Enrico; Nicoletti, Ferdinando; Copani, Agata

    2015-01-01

    ß-amyloid (Aß1−42) is produced by proteolytic cleavage of the transmembrane type-1 protein, amyloid precursor protein. Under pathological conditions, Aß1−42self-aggregates into oligomers, which cause synaptic dysfunction and neuronal loss, and are considered the culprit of Alzheimer's disease (AD). However, Aß1−42 is mainly monomeric at physiological concentrations, and the precise role of monomeric Aß1−42 in neuronal function is largely unknown. We report that the monomer of Aß1−42 activates type-1 insulin-like growth factor receptors and enhances glucose uptake in neurons and peripheral cells by promoting the translocation of the Glut3 glucose transporter from the cytosol to the plasma membrane. In neurons, activity-dependent glucose uptake was blunted after blocking endogenous Aß production, and re-established in the presence of cerebrospinal fluid Aß. APP-null neurons failed to enhance depolarization-stimulated glucose uptake unless exogenous monomeric Aß1−42 was added. These data suggest that Aß1−42 monomers were critical for maintaining neuronal glucose homeostasis. Accordingly, exogenous Aß1−42 monomers were able to rescue the low levels of glucose consumption observed in brain slices from AD mutant mice. PMID:26300732

  19. Implication of transient receptor potential vanilloid type 1 in 14,15-epoxyeicosatrienoic acid-induced angiogenesis.

    PubMed

    Su, Kuo-Hui; Lee, Kuan-I; Shyue, Song-Kun; Chen, Hsiang-Ying; Wei, Jeng; Lee, Tzong-Shyuan

    2014-01-01

    14,15-epoxyeicosatrienoic acid (14,15-EET) is implicated in regulating physiological functions of endothelial cells (ECs), yet the potential molecular mechanisms underlying the beneficial effects in ECs are not fully understood. In this study, we investigated whether transient receptor potential vanilloid receptor type 1 (TRPV1) is involved in 14,15-EET-mediated Ca(2+) influx, nitric oxide (NO) production and angiogenesis. In human microvascular endothelial cells (HMECs), 14,15-EET time-dependently increased the intracellular level of Ca(2+). Removal of extracellular Ca(2+), pharmacological inhibition or genetic disruption of TRPV1 abrogated 14,15-EET-mediated increase of intracellular Ca(2+) level in HMECs or TRPV1-transfected HEK293 cells. Furthermore, removal of extracellular Ca(2+) or pharmacological inhibition of TRPV1 decreased 14,15-EET-induced NO production. 14,15-EET-mediated tube formation was abolished by TRPV1 pharmacological inhibition. In an animal experiment, 14,15-EET-induced angiogenesis was diminished by inhibition of TRPV1 and in TRPV1-deficient mice. TRPV1 may play a crucial role in 14,15-EET-induced Ca(2+) influx, NO production and angiogenesis. PMID:25210497

  20. NAADP-mediated Ca2+ signaling via type 1 ryanodine receptor in T cells revealed by a synthetic NAADP antagonist.

    PubMed

    Dammermann, Werner; Zhang, Bo; Nebel, Merle; Cordiglieri, Chiara; Odoardi, Francesca; Kirchberger, Tanja; Kawakami, Naoto; Dowden, James; Schmid, Frederike; Dornmair, Klaus; Hohenegger, Martin; Flügel, Alexander; Guse, Andreas H; Potter, Barry V L

    2009-06-30

    The nucleotide NAADP was recently discovered as a second messenger involved in the initiation and propagation of Ca(2+) signaling in lymphoma T cells, but its impact on primary T cell function is still unknown. An optimized, synthetic, small molecule inhibitor of NAADP action, termed BZ194, was designed and synthesized. BZ194 neither interfered with Ca(2+) mobilization by d-myo-inositol 1,4,5-trisphosphate or cyclic ADP-ribose nor with capacitative Ca(2+) entry. BZ194 specifically and effectively blocked NAADP-stimulated [(3)H]ryanodine binding to the purified type 1 ryanodine receptor. Further, in intact T cells, Ca(2+) mobilization evoked by NAADP or by formation of the immunological synapse between primary effector T cells and astrocytes was inhibited by BZ194. Downstream events of Ca(2+) mobilization, such as nuclear translocation of "nuclear factor of activated T cells" (NFAT), T cell receptor-driven interleukin-2 production, and proliferation in antigen-experienced CD4(+) effector T cells, were attenuated by the NAADP antagonist. Taken together, specific inhibition of the NAADP signaling pathway constitutes a way to specifically and effectively modulate T-cell activation and has potential in the therapy of autoimmune diseases. PMID:19541638

  1. Vitamin D receptor initiation codon polymorphism influences genetic susceptibility to type 1 diabetes mellitus in the Japanese population

    PubMed Central

    Ban, Yoshiyuki; Taniyama, Matsuo; Yanagawa, Tatsuo; Yamada, Satoru; Maruyama, Taro; Kasuga, Akira; Ban, Yoshio

    2001-01-01

    Background Vitamin D has been shown to exert manifold immunomodulatory effects. Type 1 diabetes mellitus (T1DM) is regarded to be immune-mediated and vitamin D prevents the development of diabetes in the NOD mouse. We studied the association between T1DM and the initiation codon polymorphism in exon 2 of the vitamin D receptor gene in a Japanese population. We also investigated associations between the vitamin D receptor polymorphism and GAD65-antibody (Ab) positivity. We carried out polymerase chain reaction-restriction fragment length polymorphism analysis in 110 Japanese T1DM patients and 250 control subjects. GAD65 antibodies were assessed in 78 patients with T1DM. Results We found a significantly higher prevalence of the F allele / the FF genotype in the patients compared to the controls (P = 0.0069 and P = 0.014, respectively). Genotype and allele frequencies differed significantly between GAD65-Ab-positive patients and controls (P = 0.017 and P = 0.012, respectively), but neither between GAD65-Ab-negative patients and controls (P = 0.68 and P = 0.66, respectively) nor between GAD65-Ab-positive and -negative patients (P = 0.19 and P = 0.16, respectively). Conclusions Our findings suggest that the vitamin D receptor initiation codon polymorphism influences genetic susceptibility to T1DM among the Japanese. This polymorphism is also associated with GAD65-Ab-positive T1DM, although the absence of a significant difference between GAD65-Ab-negative patients and controls might be simply due to the small sample size of patients tested for GAD65 antibodies. PMID:11445000

  2. Expression of Angiotensin II Receptor-1 in Human Articular Chondrocytes

    PubMed Central

    Kawakami, Yuki; Matsuo, Kosuke; Murata, Minako; Yudoh, Kazuo; Nakamura, Hiroshi; Shimizu, Hiroyuki; Beppu, Moroe; Inaba, Yutaka; Saito, Tomoyuki; Kato, Tomohiro; Masuko, Kayo

    2012-01-01

    Background. Besides its involvement in the cardiovascular system, the renin-angiotensin-aldosterone (RAS) system has also been suggested to play an important role in inflammation. To explore the role of this system in cartilage damage in arthritis, we investigated the expression of angiotensin II receptors in chondrocytes. Methods. Articular cartilage was obtained from patients with osteoarthritis, rheumatoid arthritis, and traumatic fractures who were undergoing arthroplasty. Chondrocytes were isolated and cultured in vitro with or without interleukin (IL-1). The expression of angiotensin II receptor types 1 (AT1R) and 2 (AT2R) mRNA by the chondrocytes was analyzed using reverse transcription-polymerase chain reaction (RT-PCR). AT1R expression in cartilage tissue was analyzed using immunohistochemistry. The effect of IL-1 on AT1R/AT2R expression in the chondrocytes was analyzed by quantitative PCR and flow cytometry. Results. Chondrocytes from all patient types expressed AT1R/AT2R mRNA, though considerable variation was found between samples. Immunohistochemical analysis confirmed AT1R expression at the protein level. Stimulation with IL-1 enhanced the expression of AT1R/AT2R mRNA in OA and RA chondrocytes. Conclusions. Human articular chondrocytes, at least partially, express angiotensin II receptors, and IL-1 stimulation induced AT1R/AT2R mRNA expression significantly. PMID:23346400

  3. Angiotensin II receptors in the gonads

    SciTech Connect

    Aguilera, G.; Millan, M.A.; Harwood, J.P.

    1989-05-01

    The presence of components of the renin-angiotensin system in ovaries and testes suggests that angiotensin II (AII) is involved in gonadal function, and thus we sought to characterize receptors for AII in rat and primate gonads. In the testes, autoradiographic studies showed receptors in the interstitium in all species. In rat interstitial cells fractionated by Percoll gradient, AII receptors coincided with hCG receptors indicating that AII receptors are located on the Leydig cells. In Leydig cells and membranes from rat and rhesus monkey prepuberal testes, AII receptors were specific for AII analogues and of high affinity (Kd=nM). During development, AII receptor content in rat testes decreases with age parallel to a fall in the ratio of interstitial to tubular tissue. In the ovary, the distribution of AII receptors was dependent on the stage of development, being high in the germinal epithelium and stromal tissue between five and 15 days, and becoming localized in secondary follicles in 20-and 40-day-old rats. No binding was found in primordial or primary follicles. In rhesus monkey ovary, AII receptors were higher in stromal tissue and lower in granulosa and luteal cells of the follicles. Characterization of the binding in rat and monkey ovarian membranes showed a single class of sites with a Kd in the nmol/L range and specificity similar to that of the adrenal glomerulosa and testicular AII receptors. Receptors for AII were also present in membrane fractions from PMSG/hCG primed rat ovaries. Infusion of AII (25 ng/min) or captopril (1.4 micrograms/min) during the PMSG/hCG induction period had no effect on ovarian weight or AII receptor concentration in the ovaries.

  4. Plant-derived cannabinoids modulate the activity of transient receptor potential channels of ankyrin type-1 and melastatin type-8.

    PubMed

    De Petrocellis, Luciano; Vellani, Vittorio; Schiano-Moriello, Aniello; Marini, Pietro; Magherini, Pier Cosimo; Orlando, Pierangelo; Di Marzo, Vincenzo

    2008-06-01

    The plant cannabinoids (phytocannabinoids), cannabidiol (CBD), and Delta(9)-tetrahydrocannabinol (THC) were previously shown to activate transient receptor potential channels of both vanilloid type 1 (TRPV1) and ankyrin type 1 (TRPA1), respectively. Furthermore, the endocannabinoid anandamide is known to activate TRPV1 and was recently found to antagonize the menthol- and icilin-sensitive transient receptor potential channels of melastatin type 8 (TRPM8). In this study, we investigated the effects of six phytocannabinoids [i.e., CBD, THC, CBD acid, THC acid, cannabichromene (CBC), and cannabigerol (CBG)] on TRPA1- and TRPM8-mediated increase in intracellular Ca2+ in either HEK-293 cells overexpressing the two channels or rat dorsal root ganglia (DRG) sensory neurons. All of the compounds tested induced TRPA1-mediated Ca2+ elevation in HEK-293 cells with efficacy comparable with that of mustard oil isothiocyanates (MO), the most potent being CBC (EC(50) = 60 nM) and the least potent being CBG and CBD acid (EC(50) = 3.4-12.0 microM). CBC also activated MO-sensitive DRG neurons, although with lower potency (EC(50) = 34.3 microM). Furthermore, although none of the compounds tested activated TRPM8-mediated Ca2+ elevation in HEK-293 cells, they all, with the exception of CBC, antagonized this response when it was induced by either menthol or icilin. CBD, CBG, THC, and THC acid were equipotent (IC(50) = 70-160 nM), whereas CBD acid was the least potent compound (IC(50) = 0.9-1.6 microM). CBG inhibited Ca2+ elevation also in icilin-sensitive DRG neurons with potency (IC(50) = 4.5 microM) similar to that of anandamide (IC(50) = 10 microM). Our findings suggest that phytocannabinoids and cannabis extracts exert some of their pharmacological actions also by interacting with TRPA1 and TRPM8 channels, with potential implications for the treatment of pain and cancer. PMID:18354058

  5. Evaluation of MRI and cannabinoid type 1 receptor PET templates constructed using DARTEL for spatial normalization of rat brains

    SciTech Connect

    Kronfeld, Andrea; Müller-Forell, Wibke; Buchholz, Hans-Georg; Maus, Stephan; Reuss, Stefan; Schreckenberger, Mathias; Miederer, Isabelle; Lutz, Beat

    2015-12-15

    Purpose: Image registration is one prerequisite for the analysis of brain regions in magnetic-resonance-imaging (MRI) or positron-emission-tomography (PET) studies. Diffeomorphic anatomical registration through exponentiated Lie algebra (DARTEL) is a nonlinear, diffeomorphic algorithm for image registration and construction of image templates. The goal of this small animal study was (1) the evaluation of a MRI and calculation of several cannabinoid type 1 (CB1) receptor PET templates constructed using DARTEL and (2) the analysis of the image registration accuracy of MR and PET images to their DARTEL templates with reference to analytical and iterative PET reconstruction algorithms. Methods: Five male Sprague Dawley rats were investigated for template construction using MRI and [{sup 18}F]MK-9470 PET for CB1 receptor representation. PET images were reconstructed using the algorithms filtered back-projection, ordered subset expectation maximization in 2D, and maximum a posteriori in 3D. Landmarks were defined on each MR image, and templates were constructed under different settings, i.e., based on different tissue class images [gray matter (GM), white matter (WM), and GM + WM] and regularization forms (“linear elastic energy,” “membrane energy,” and “bending energy”). Registration accuracy for MRI and PET templates was evaluated by means of the distance between landmark coordinates. Results: The best MRI template was constructed based on gray and white matter images and the regularization form linear elastic energy. In this case, most distances between landmark coordinates were <1 mm. Accordingly, MRI-based spatial normalization was most accurate, but results of the PET-based spatial normalization were quite comparable. Conclusions: Image registration using DARTEL provides a standardized and automatic framework for small animal brain data analysis. The authors were able to show that this method works with high reliability and validity. Using DARTEL

  6. CD4-Independent Infection of Astrocytes by Human Immunodeficiency Virus Type 1: Requirement for the Human Mannose Receptor

    PubMed Central

    Liu, Ying; Liu, Hao; Kim, Byung Oh; Gattone, Vincent H.; Li, Jinliang; Nath, Avindra; Blum, Janice; He, Johnny J.

    2004-01-01

    Human immunodeficiency virus type 1 (HIV-1) infection occurs in the central nervous system and causes a variety of neurobehavioral and neuropathological disorders. Both microglia, the residential macrophages in the brain, and astrocytes are susceptible to HIV-1 infection. Unlike microglia that express and utilize CD4 and chemokine coreceptors CCR5 and CCR3 for HIV-1 infection, astrocytes fail to express CD4. Astrocytes express several chemokine coreceptors; however, the involvement of these receptors in astrocyte HIV-1 infection appears to be insignificant. In the present study using an expression cloning strategy, the cDNA for the human mannose receptor (hMR) was found to be essential for CD4-independent HIV-1 infectivity. Ectopic expression of functional hMR rendered U87.MG astrocytic cells susceptible to HIV-1 infection, whereas anti-hMR serum and hMR-specific siRNA blocked HIV-1 infection in human primary astrocytes. In agreement with these findings, hMR bound to HIV-1 virions via the abundant and highly mannosylated sugar moieties of HIV-1 envelope glycoprotein gp120 in a Ca2+-dependent fashion. Moreover, hMR-mediated HIV-1 infection was dependent upon endocytic trafficking as assessed by transmission electron microscopy, as well as inhibition of viral entry by endosomo- and lysosomotropic drugs. Taken together, these results demonstrate the direct involvement of hMR in HIV-1 infection of astrocytes and suggest that HIV-1 interaction with hMR plays an important role in HIV-1 neuropathogenesis. PMID:15047828

  7. Type 1 cannabinoid receptor ligands display functional selectivity in a cell culture model of striatal medium spiny projection neurons.

    PubMed

    Laprairie, Robert B; Bagher, Amina M; Kelly, Melanie E M; Dupré, Denis J; Denovan-Wright, Eileen M

    2014-09-01

    Modulation of type 1 cannabinoid receptor (CB1) activity has been touted as a potential means of treating addiction, anxiety, depression, and neurodegeneration. Different agonists of CB1 are known to evoke varied responses in vivo. Functional selectivity is the ligand-specific activation of certain signal transduction pathways at a receptor that can signal through multiple pathways. To understand cannabinoid-specific functional selectivity, different groups have examined the effect of individual cannabinoids on various signaling pathways in heterologous expression systems. In the current study, we compared the functional selectivity of six cannabinoids, including two endocannabinoids (2-arachidonyl glycerol (2-AG) and anandamide (AEA)), two synthetic cannabinoids (WIN55,212-2 and CP55,940), and two phytocannabinoids (cannabidiol (CBD) and Δ(9)-tetrahydrocannabinol (THC)) on arrestin2-, Gα(i/o)-, Gβγ-, Gα(s)-, and Gα(q)-mediated intracellular signaling in the mouse STHdh(Q7/Q7) cell culture model of striatal medium spiny projection neurons that endogenously express CB1. In this system, 2-AG, THC, and CP55,940 were more potent mediators of arrestin2 recruitment than other cannabinoids tested. 2-AG, AEA, and WIN55,212-2, enhanced Gα(i/o) and Gβγ signaling, with 2-AG and AEA treatment leading to increased total CB1 levels. 2-AG, AEA, THC, and WIN55,212-2 also activated Gα(q)-dependent pathways. CP55,940 and CBD both signaled through Gα(s). CP55,940, but not CBD, activated downstream Gα(s) pathways via CB1 targets. THC and CP55,940 promoted CB1 internalization and decreased CB1 protein levels over an 18-h period. These data demonstrate that individual cannabinoids display functional selectivity at CB1 leading to activation of distinct signaling pathways. To effectively match cannabinoids with therapeutic goals, these compounds must be screened for their signaling bias. PMID:25037227

  8. Toll-Like Receptor 3 Is Critical for Coxsackievirus B4-Induced Type 1 Diabetes in Female NOD Mice

    PubMed Central

    Thuma, Jean R.; Courreges, Maria C.; Benencia, Fabian; James, Calvin B.L.; Malgor, Ramiro; Kantake, Noriko; Mudd, William; Denlinger, Nathan; Nolan, Bret; Wen, Li; Schwartz, Frank L.

    2015-01-01

    Group B coxsackieviruses (CVBs) are involved in triggering some cases of type 1 diabetes mellitus (T1DM). However, the molecular mechanism(s) responsible for this remain elusive. Toll-like receptor 3 (TLR3), a receptor that recognizes viral double-stranded RNA, is hypothesized to play a role in virus-induced T1DM, although this hypothesis is yet to be substantiated. The objective of this study was to directly investigate the role of TLR3 in CVB-triggered T1DM in nonobese diabetic (NOD) mice, a mouse model of human T1DM that is widely used to study both spontaneous autoimmune and viral-induced T1DM. As such, we infected female wild-type (TLR3+/+) and TLR3 knockout (TLR3−/−) NOD mice with CVB4 and compared the incidence of diabetes in CVB4-infected mice with that of uninfected counterparts. We also evaluated the islets of uninfected and CVB4-infected wild-type and TLR3 knockout NOD mice by immunohistochemistry and insulitis scoring. TLR3 knockout mice were markedly protected from CVB4-induced diabetes compared with CVB4-infected wild-type mice. CVB4-induced T-lymphocyte-mediated insulitis was also significantly less severe in TLR3 knockout mice compared with wild-type mice. No differences in insulitis were observed between uninfected animals, either wild-type or TLR3 knockout mice. These data demonstrate for the first time that TLR3 is 1) critical for CVB4-induced T1DM, and 2) modulates CVB4-induced insulitis in genetically prone NOD mice. PMID:25422874

  9. Targeting the Transient Receptor Potential Vanilloid Type 1 (TRPV1) Assembly Domain Attenuates Inflammation-induced Hypersensitivity*

    PubMed Central

    Flynn, Robyn; Chapman, Kevin; Iftinca, Mircea; Aboushousha, Reem; Varela, Diego; Altier, Christophe

    2014-01-01

    The transient receptor potential channel vanilloid type 1 (TRPV1) is a non-selective cation channel expressed in sensory neurons of the dorsal root and trigeminal ganglia. TRPV1 is a polymodal channel activated by noxious heat, capsaicin, and protons. As a sensor for noxious stimuli, TRPV1 channel has been described as a key contributor to pain signaling. To form a functional channel, TRPV1 subunits must assemble into tetramers, and several studies have identified the TRPV1 C terminus as an essential element in subunit association. Here we combined biochemical assays with electrophysiology and imaging-based bimolecular fluorescence complementation (BiFC) and bioluminescence resonance energy transfer (BRET) in live cells to identify a short motif in the C-terminal tail of the TRPV1 subunit that governs channel assembly. Removing this region through early truncation or targeted deletion results in loss of subunit association and channel function. Importantly, we found that interfering with TRPV1 subunit association using a plasma membrane-tethered peptide attenuated mechanical and thermal hypersensitivity in two mouse models of inflammatory hyperalgesia. This represents a novel mechanism to disrupt TRPV1 subunit assembly and hence may offer a new analgesic tool for pain relief. PMID:24808184

  10. Targeting the transient receptor potential vanilloid type 1 (TRPV1) assembly domain attenuates inflammation-induced hypersensitivity.

    PubMed

    Flynn, Robyn; Chapman, Kevin; Iftinca, Mircea; Aboushousha, Reem; Varela, Diego; Altier, Christophe

    2014-06-13

    The transient receptor potential channel vanilloid type 1 (TRPV1) is a non-selective cation channel expressed in sensory neurons of the dorsal root and trigeminal ganglia. TRPV1 is a polymodal channel activated by noxious heat, capsaicin, and protons. As a sensor for noxious stimuli, TRPV1 channel has been described as a key contributor to pain signaling. To form a functional channel, TRPV1 subunits must assemble into tetramers, and several studies have identified the TRPV1 C terminus as an essential element in subunit association. Here we combined biochemical assays with electrophysiology and imaging-based bimolecular fluorescence complementation (BiFC) and bioluminescence resonance energy transfer (BRET) in live cells to identify a short motif in the C-terminal tail of the TRPV1 subunit that governs channel assembly. Removing this region through early truncation or targeted deletion results in loss of subunit association and channel function. Importantly, we found that interfering with TRPV1 subunit association using a plasma membrane-tethered peptide attenuated mechanical and thermal hypersensitivity in two mouse models of inflammatory hyperalgesia. This represents a novel mechanism to disrupt TRPV1 subunit assembly and hence may offer a new analgesic tool for pain relief. PMID:24808184

  11. Capsaicin-induced inhibition of platelet aggregation is not mediated by transient receptor potential vanilloid type 1.

    PubMed

    Mittelstadt, Scott W; Nelson, Richard A; Daanen, Jerome F; King, Andrew J; Kort, Michael E; Kym, Philip R; Lubbers, Nathan L; Cox, Bryan F; Lynch, James J

    2012-01-01

    Capsaicin is an agonist of transient receptor potential vanilloid type 1 (TRPV1), in which it can act as a neuronal stimulant and result in nociception. Capsaicin also affects a variety of nonneuronal tissues, in which its mechanisms of action are less certain. The present study investigated whether the inhibitory effects of capsaicin on platelet aggregation are mediated via TRPV1. Venous whole blood obtained from beagle dogs (n = 6) was preincubated with capsaicin and/or the potent and selective competitive TRPV1 antagonist, A-993610 and then exposed to collagen (2 μg/ml). An aggregometer was used to quantify the platelet response. Capsaicin exposure inhibited collagen-induced platelet aggregation in a concentration-dependent manner, with significant effects at 10 and 30 μg capsaicin per millilitre. A-993610 alone (0.1-1.0 μg/ml) had no effects on collagen-induced platelet aggregation, nor did it have any effects on capsaicin's ability to inhibit platelet aggregation. The current results agree with previous findings that capsaicin can inhibit platelet aggregation. In addition, the present study demonstrates that capsaicin's inhibitory effect on collagen-induced canine platelet aggregation is not mediated by TRPV1. PMID:22089942

  12. Interactions between Environmental Factors and Melatonin Receptor Type 1A Polymorphism in Relation to Oral Cancer Susceptibility and Clinicopathologic Development

    PubMed Central

    Yang, Shun-Fa; Lee, Wei-Jiunn; Lin, Yung-Wei; Lee, Liang-Ming; Chang, Junn-Liang; Weng, Wei-Chun; Lin, Chien-Huang; Chien, Ming-Hsien

    2015-01-01

    Background The purpose of this study was to explore the combined effect of melatonin receptor type 1A (MTNR1A) gene polymorphisms and exposure to environmental carcinogens on the susceptibility and clinicopathological characteristics of oral cancer. Methodology and Principal Findings Three polymorphisms of the MTNR1A gene from 618 patients with oral cancer and 560 non-cancer controls were analyzed by real-time polymerase chain reaction (PCR). The CTA haplotype of the studied MTNR1A polymorphisms (rs2119882, rs13140012, rs6553010) was related to a higher risk of oral cancer. Moreover, MTNR1A gene polymorphisms exhibited synergistic effects of environmental factors (betel quid and tobacco use) on the susceptibility of oral cancer. Finally, oral-cancer patients with betel quid-chewing habit who had T/T allele of MTNR1A rs13140012 were at higher risk for developing an advanced clinical stage and lymph node metastasis. Conclusion These results support gene-environment interactions of MTNR1A polymorphisms with smoking and betel quid-chewing habits possibly altering oral-cancer susceptibility and metastasis. PMID:25806809

  13. Effects of Type 1 Insulin-Like Growth Factor Receptor Silencing in a Human Adrenocortical Cell Line.

    PubMed

    Ribeiro, T C; Jorge, A A; Montenegro, L R; Almeida, M Q; Ferraz-de-Souza, B; Nishi, M Y; Mendonca, B B; Latronico, A C

    2016-07-01

    Type 1 insulin-like growth factor receptor (IGF-1R) is overexpressed in a variety of human cancers, including adrenocortical tumors. The aim of the work was to investigate the effects of IGF-1R downregulation in a human adrenocortical cell line by small interfering RNA (siRNA). The human adrenocortical tumor cell line NCI H295R was transfected with 2 specific IGF1R siRNAs (# 1 and # 2) and compared with untreated cells and a negative control siRNA. IGF1R expression was determined by quantitative reverse-transcription PCR (qRTPCR) and Western blot. The effects of IGF-1R downregulation on cell proliferation and apoptosis were assessed. IGF-1R levels were significantly decreased in cells treated with IGF-1R siRNA # 1 or # 2. Relative expression of IGF1R mRNA decreased approximately 50% and Western blot analysis revealed a 30% of reduction in IGF-1R protein. Downregulation of this gene resulted in 40% reduction in cell growth in vitro and 45% increase in apoptosis using siRNA # 2. These findings demonstrate that decreasing IGF-1R mRNA and protein expression in NCI H295R cells can partially inhibit adrenal tumor cell growth in vitro. Targeting IGF1R is a promising therapy for pediatric malignant adrenocortical tumor and can still be an option for adult adrenocortical cancer based on personalized genomic tumor profiling. PMID:27246621

  14. Biomechanical forces exert anabolic effects on osteoblasts by activation of SMAD 1/5/8 through type 1 BMP receptor

    PubMed Central

    Rath, B.; Nam, J.; Deschner, J.; Schaumburger, J.; Tingart, M.; Grässel, S.; Grifka, J.; Agarwal, S.

    2016-01-01

    Osteoblasts are mechanosensitive cells, which respond to biomechanical stimuli to regulate the bone structure through anabolic and catabolic gene regulation. To examine the effects of mechanical forces on the osteogenic responses through the SMAD signaling in osteoblasts, the cells were cultured in well-characterized mechanoresponsive 3-D scaffolds and exposed to 10% dynamic compressive strain (Cmp) at 1 Hz. Subsequently, SMAD phosphorylation and osteogenic gene induction was examined. Osteoblasts cultured in 3-D scaffolds exhibited increased constitutive SMAD 1/5/8 phosphorylation, as compared to monolayers cultures. This SMAD 1/5/8 phosphorylation was further upregulated after 10, 30 and 60 min in response to Cmp, exhibiting a peak activation at 30 min. No significant changes in SMAD2 phosphorylation were observed, suggesting signals generated by Cmp may not activate the Transforming Growth Factor-β signaling cascade. Subsequently, biomechanical stimulation-induced SMAD 1/5/8 phosphorylation upregulated the expression of osteogenic genes such as Osteoprotegrin, Msx2 and Runx2. Dorsomorphin, a selective inhibitor of the bone morphogenetic protein (BMP) receptor type 1 (BMPR1), blocked Cmp-induced SMAD 1/5/8 phosphorylation, as well as Osteoprotegrin, Msx2 and Runx2 gene expression. Collectively, the present findings demonstrate that biomechanical stimulation of osteoblasts activates SMAD 1/5/8 in the BMP signaling pathway through BMPR1 and may enhance osteogenesis by upregulating SMAD-dependent osteogenic genes. PMID:21515935

  15. Expression patterns of taste receptor type 1 subunit 3 and α-gustducin in the mouse testis during development.

    PubMed

    Gong, Ting; Wei, Quanwei; Mao, Dagan; Shi, Fangxiong

    2016-01-01

    Taste receptor type 1 subunit 3 (T1R3) and its associated heterotrimeric G protein α-gustducin (Gα) are involved in sweet and umami sensing in taste cells. They are also strongly expressed in the testis and sperm, but their expression patterns and potential roles involved were previously unknown. In present study, we investigated the expression patterns of T1R3 and Gα in the mouse testis at critical stages of postnatal life, and throughout the spermatogenic cycle. Our results indicated that T1R3 and Gα exhibited a stage-dependent expression pattern during mouse development, and a cell-specific pattern during the spermatogenic cycle. Their expressions have been increased significantly from prepubertal to pubertal periods (P<005), and decreased significantly in aged mice (P<005). The changes were mainly attributed to the differential expression of T1R3 or Gα in elongated spermatids and Leydig cells at different stages of the spermatogenic cycle. In addition, the expression of T1R3 and Gα were first observed in residual bodies of spermatozoa and endothelial cells of blood vessels at post-pubertal mice, while Gα was located in apoptotic spermatogonia of postnatal mice. These novel expression patterns suggest a role of T1R3 and Gα in the onset of spermatogenesis, pace of spermatogenic cycle, and aging of the testis. PMID:26589384

  16. Transient receptor potential vanilloid type-1 channel regulates diet-induced obesity, insulin resistance, and leptin resistance.

    PubMed

    Lee, Eunjung; Jung, Dae Young; Kim, Jong Hun; Patel, Payal R; Hu, Xiaodi; Lee, Yongjin; Azuma, Yoshihiro; Wang, Hsun-Fan; Tsitsilianos, Nicholas; Shafiq, Umber; Kwon, Jung Yeon; Lee, Hyong Joo; Lee, Ki Won; Kim, Jason K

    2015-08-01

    Insulin resistance is a major characteristic of obesity and type 2 diabetes, but the underlying mechanism is unclear. Recent studies have shown a metabolic role of capsaicin that may be mediated via the transient receptor potential vanilloid type-1 (TRPV1) channel. In this study, TRPV1 knockout (KO) and wild-type (WT) mice (as controls) were fed a high-fat diet (HFD), and metabolic studies were performed to measure insulin and leptin action. The TRPV1 KO mice became more obese than the WT mice after HFD, partly attributed to altered energy balance and leptin resistance in the KO mice. The hyperinsulinemic-euglycemic clamp experiment showed that the TRPV1 KO mice were more insulin resistant after HFD because of the ∼40% reduction in glucose metabolism in the white and brown adipose tissue, compared with that in the WT mice. Leptin treatment failed to suppress food intake, and leptin-mediated hypothalamic signal transducer and activator of transcription (STAT)-3 activity was blunted in the TRPV1 KO mice. We also found that the TRPV1 KO mice were more obese and insulin resistant than the WT mice at 9 mo of age. Taken together, these results indicate that lacking TRPV1 exacerbates the obesity and insulin resistance associated with an HFD and aging, and our findings further suggest that TRPV1 has a major role in regulating glucose metabolism and hypothalamic leptin's effects in obesity. PMID:25888600

  17. Low-cytotoxic synthetic bromorutaecarpine exhibits anti-inflammation and activation of transient receptor potential vanilloid type 1 activities.

    PubMed

    Lee, Chi-Ming; Gu, Jiun-An; Rau, Tin-Gan; Yang, Che-Hsiung; Yang, Wei-Chi; Huang, Shih-Hao; Lin, Feng-Yen; Lin, Chun-Mao; Huang, Sheng-Tung

    2013-01-01

    Rutaecarpine (RUT), the major bioactive ingredient isolated from the Chinese herb Evodia rutaecarpa, possesses a wide spectrum of biological activities, including anti-inflammation and preventing cardiovascular diseases. However, its high cytotoxicity hampers pharmaceutical development. We designed and synthesized a derivative of RUT, bromo-dimethoxyrutaecarpine (Br-RUT), which showed no cytotoxicity at 20 μM. Br-RUT suppressed nitric oxide (NO) production and tumor necrosis factor-α release in concentration-dependent (0~20 μM) manners in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages; protein levels of inducible NO synthase (iNOS) and cyclooxygenase-2 induced by LPS were downregulated. Br-RUT inhibited cell migration and invasion of ovarian carcinoma A2780 cells with 0~48 h of treatment. Furthermore, Br-RUT enhanced the expression of transient receptor potential vanilloid type 1 and activated endothelial NOS in human aortic endothelial cells. These results suggest that the synthetic Br-RUT possesses very low cytotoxicity but retains its activities against inflammation and vasodilation that could be beneficial for cardiovascular disease therapeutics. PMID:24369537

  18. Glucagon receptor antibody completely suppresses type 1 diabetes phenotype without insulin by disrupting a novel diabetogenic pathway

    PubMed Central

    Wang, May-Yun; Yan, Hai; Shi, Zhiqing; Evans, Matthew R.; Yu, Xinxin; Lee, Young; Chen, Shiuhwei; Williams, Annie; Philippe, Jacques; Roth, Michael G.; Unger, Roger H.

    2015-01-01

    Insulin monotherapy can neither maintain normoglycemia in type 1 diabetes (T1D) nor prevent the long-term damage indicated by elevated glycation products in blood, such as glycated hemoglobin (HbA1c). Here we find that hyperglycemia, when unaccompanied by an acute increase in insulin, enhances itself by paradoxically stimulating hyperglucagonemia. Raising glucose from 5 to 25 mM without insulin enhanced glucagon secretion ∼two- to fivefold in InR1-G9 α cells and ∼18-fold in perfused pancreata from insulin-deficient rats with T1D. Mice with T1D receiving insulin treatment paradoxically exhibited threefold higher plasma glucagon during hyperglycemic surges than during normoglycemic intervals. Blockade of glucagon action with mAb Ac, a glucagon receptor (GCGR) antagonizing antibody, maintained glucose below 100 mg/dL and HbA1c levels below 4% in insulin-deficient mice with T1D. In rodents with T1D, hyperglycemia stimulates glucagon secretion, up-regulating phosphoenolpyruvate carboxykinase and enhancing hyperglycemia. GCGR antagonism in mice with T1D normalizes glucose and HbA1c, even without insulin. PMID:25675519

  19. Type 1 inositol trisphosphate receptor regulates cerebellar circuits by maintaining the spine morphology of purkinje cells in adult mice.

    PubMed

    Sugawara, Takeyuki; Hisatsune, Chihiro; Le, Tung Dinh; Hashikawa, Tsutomu; Hirono, Moritoshi; Hattori, Mitsuharu; Nagao, Soichi; Mikoshiba, Katsuhiko

    2013-07-24

    The structural maintenance of neural circuits is critical for higher brain functions in adulthood. Although several molecules have been identified as regulators for spine maintenance in hippocampal and cortical neurons, it is poorly understood how Purkinje cell (PC) spines are maintained in the mature cerebellum. Here we show that the calcium channel type 1 inositol trisphosphate receptor (IP3R1) in PCs plays a crucial role in controlling the maintenance of parallel fiber (PF)-PC synaptic circuits in the mature cerebellum in vivo. Significantly, adult mice lacking IP3R1 specifically in PCs (L7-Cre;Itpr1(flox/flox)) showed dramatic increase in spine density and spine length of PCs, despite having normal spines during development. In addition, the abnormally rearranged PF-PC synaptic circuits in mature cerebellum caused unexpectedly severe ataxia in adult L7-Cre;Itpr1(flox/flox) mice. Our findings reveal a specific role for IP3R1 in PCs not only as an intracellular mediator of cerebellar synaptic plasticity induction, but also as a critical regulator of PF-PC synaptic circuit maintenance in the mature cerebellum in vivo; this mechanism may underlie motor coordination and learning in adults. PMID:23884927

  20. Distinct effect of stress on 11beta-hydroxysteroid dehydrogenase type 1 and corticosteroid receptors in dorsal and ventral hippocampus.

    PubMed

    Ergang, P; Kuželová, A; Soták, M; Klusoňová, P; Makal, J; Pácha, J

    2014-01-01

    Multiple lines of evidence suggest the participation of the hippocampus in the feedback inhibition of the hypothalamus-pituitary-adrenal axis during stress response. This inhibition is mediated by glucocorticoid feedback due to the sensitivity of the hippocampus to these hormones. The sensitivity is determined by the expression of glucocorticoid (GR) and mineralocorticoid (MR) receptors and 11beta-hydroxysteroid dehydrogenase type 1 (11HSD1), an enzyme that regulates the conversion of glucocorticoids from inactive to active form. The goal of our study was to assess the effect of stress on the expression of 11HSD1, GR and MR in the ventral and dorsal region of the CA1 hippocampus in three different rat strains with diverse responses to stress: Fisher 344, Lewis and Wistar. Stress stimulated 11HSD1 in the ventral but not dorsal CA1 hippocampus of Fisher 344 but not Lewis or Wistar rats. In contrast, GR expression following stress was decreased in the dorsal but not ventral CA1 hippocampus of all three strains. MR expression was not changed in either the dorsal or ventral CA1 region. These results indicate that (1) depending on the strain, stress stimulates 11HSD1 in the ventral hippocampus, which is known to be involved in stress and emotion reactions whereas (2) independent of strain, stress inhibits GR in the dorsal hippocampus, which is predominantly involved in cognitive functions. PMID:24397806

  1. The type 1 insulin-like growth factor receptor (IGF-IR) pathway is mandatory for the follistatin-induced skeletal muscle hypertrophy.

    PubMed

    Kalista, S; Schakman, O; Gilson, H; Lause, P; Demeulder, B; Bertrand, L; Pende, M; Thissen, J P

    2012-01-01

    Myostatin inhibition by follistatin (FS) offers a new approach for muscle mass enhancement. The aim of the present study was to characterize the mediators responsible for the FS hypertrophic action on skeletal muscle in male mice. Because IGF-I and IGF-II, two crucial skeletal muscle growth factors, are induced by myostatin inhibition, we assessed their role in FS action. First, we tested whether type 1 IGF receptor (IGF-IR) is required for FS-induced hypertrophy. By using mice expressing a dominant-negative IGF-IR in skeletal muscle, we showed that IGF-IR inhibition blunted by 63% fiber hypertrophy caused by FS. Second, we showed that FS caused the same degree of fiber hypertrophy in wild-type and IGF-II knockout mice. We then tested the role of the signaling molecules stimulated by IGF-IR, in particular the Akt/mammalian target of rapamycin (mTOR)/70-kDa ribosomal protein S6 kinase (S6K) pathway. We investigated whether Akt phosphorylation is required for the FS action. By cotransfecting a dominant-negative form of Akt together with FS, we showed that Akt inhibition reduced by 65% fiber hypertrophy caused by FS. Second, we evaluated the role of mTOR in FS action. Fiber hypertrophy induced by FS was reduced by 36% in rapamycin-treated mice. Finally, because the activity of S6K is increased by FS, we tested its role in FS action. FS caused the same degree of fiber hypertrophy in wild-type and S6K1/2 knockout mice. In conclusion, the IGF-IR/Akt/mTOR pathway plays a critical role in FS-induced muscle hypertrophy. In contrast, induction of IGF-II expression and S6K activity by FS are not required for the hypertrophic action of FS. PMID:22087027

  2. Molecular mechanism of action of triazolobenzodiazepinone agonists of the type 1 cholecystokinin receptor. Possible cooperativity across the receptor homo-dimeric complex

    PubMed Central

    Desai, Aditya J.; Lam, Polo C.H.; Orry, Andrew; Abagyan, Ruben; Christopoulos, Arthur; Sexton, Patrick M.; Miller, Laurence J.

    2016-01-01

    The type 1 cholecystokinin receptor (CCK1R) has multiple physiologic roles relating to nutrient homeostasis, including mediation of post-cibal satiety. This effect has been central in efforts to develop agonists of this receptor as part of a program to manage and/or prevent obesity. While a number of small molecule CCK1R agonists have been developed, none has yet been approved for clinical use, based on inadequate efficacy, side effects, or the potential for toxicity. Understanding the molecular details of docking and mechanism of action of these ligands can be helpful in the rational refinement and enhancement of small molecule drug candidates. In the current work, we have defined the mechanism of binding and activity of two triazolobenzodiazepinones, CE-326597 and PF-04756956, which are reported to be full agonist ligands. To achieve this, we utilized receptor binding with a series of allosteric and orthosteric radioligands at structurally-related CCK1R and CCK2R, as well as chimeric CCK1R/CCK2R constructs exchanging residues in the allosteric pocket, and assessment of biological activity. These triazolobenzodiazepinones docked within the intramembranous small molecule allosteric ligand pocket, with higher affinity binding to CCK2R than CCK1R, yet with biological activity exclusive to or greatly enhanced at CCK1R. These ligands exhibited cooperativity with benzodiazepine binding across the CCK1R homodimeric complex, resulting in their ability to inhibit only a fraction of the saturable binding of a benzodiazepine radioligand, unlike other small molecule antagonists and agonists of this receptor. This may contribute to the understanding of the unique short duration and reversible gallbladder contraction observed in vivo upon administration of these drugs. PMID:26654202

  3. The stress protein heat shock cognate 70 (Hsc70) inhibits the Transient Receptor Potential Vanilloid type 1 (TRPV1) channel

    PubMed Central

    Iftinca, Mircea; Flynn, Robyn; Basso, Lilian; Melo, Helvira; Aboushousha, Reem; Taylor, Lauren

    2016-01-01

    Background Specialized cellular defense mechanisms prevent damage from chemical, biological, and physical hazards. The heat shock proteins have been recognized as key chaperones that maintain cell survival against a variety of exogenous and endogenous stress signals including noxious temperature. However, the role of heat shock proteins in nociception remains poorly understood. We carried out an expression analysis of the constitutively expressed 70 kDa heat-shock cognate protein, a member of the stress-induced HSP70 family in lumbar dorsal root ganglia from a mouse model of Complete Freund’s Adjuvant-induced chronic inflammatory pain. We used immunolabeling of dorsal root ganglion neurons, behavioral analysis and patch clamp electrophysiology in both dorsal root ganglion neurons and HEK cells transfected with Hsc70 and Transient Receptor Potential Channels to examine their functional interaction in heat shock stress condition. Results We report an increase in protein levels of Hsc70 in mouse dorsal root ganglia, 3 days post Complete Freund’s Adjuvant injection in the hind paw. Immunostaining of Hsc70 was observed in most of the dorsal root ganglion neurons, including the small size nociceptors immunoreactive to the TRPV1 channel. Standard whole-cell patch-clamp technique was used to record Transient Receptor Potential Vanilloid type 1 current after exposure to heat shock. We found that capsaicin-evoked currents are inhibited by heat shock in dorsal root ganglion neurons and transfected HEK cells expressing Hsc70 and TRPV1. Blocking Hsc70 with matrine or spergualin compounds prevented heat shock-induced inhibition of the channel. We also found that, in contrast to TRPV1, both the cold sensor channels TRPA1 and TRPM8 were unresponsive to heat shock stress. Finally, we show that inhibition of TRPV1 depends on the ATPase activity of Hsc70 and involves the rho-associated protein kinase. Conclusions Our work identified Hsc70 and its ATPase activity as a central

  4. Genetic Mapping at 3-Kilobase Resolution Reveals Inositol 1,4,5-Triphosphate Receptor 3 as a Risk Factor for Type 1 Diabetes in Sweden

    PubMed Central

    Roach, Jared C.; Deutsch, Kerry; Li, Sarah; Siegel, Andrew F.; Bekris, Lynn M.; Einhaus, Derek C.; Sheridan, Colleen M.; Glusman, Gustavo; Hood, Leroy; Lernmark, Åke; Janer, Marta

    2006-01-01

    We mapped the genetic influences for type 1 diabetes (T1D), using 2,360 single-nucleotide polymorphism (SNP) markers in the 4.4-Mb human major histocompatibility complex (MHC) locus and the adjacent 493 kb centromeric to the MHC, initially in a survey of 363 Swedish T1D cases and controls. We confirmed prior studies showing association with T1D in the MHC, most significantly near HLA-DR/DQ. In the region centromeric to the MHC, we identified a peak of association within the inositol 1,4,5-triphosphate receptor 3 gene (ITPR3; formerly IP3R3). The most significant single SNP in this region was at the center of the ITPR3 peak of association (P=1.7×10-4 for the survey study). For validation, we typed an additional 761 Swedish individuals. The P value for association computed from all 1,124 individuals was 1.30×10-6 (recessive odds ratio 2.5; 95% confidence interval [CI] 1.7–3.9). The estimated population-attributable risk of 21.6% (95% CI 10.0%–31.0%) suggests that variation within ITPR3 reflects an important contribution to T1D in Sweden. Two-locus regression analysis supports an influence of ITPR3 variation on T1D that is distinct from that of any MHC class II gene. PMID:16960798

  5. Host Avian Beta-Defensin and Toll-Like Receptor Responses of Pigeons following Infection with Pigeon Paramyxovirus Type 1

    PubMed Central

    Li, Yanyan; Xu, Qianqian; Zhang, Tingting; Gao, Mengying; Wang, Qiuling; Han, Zongxi; Shao, Yuhao

    2015-01-01

    The high morbidity and mortality in pigeons caused by pigeon paramyxovirus type 1 (PPMV-1) highlights the need for new insights into the host immune response and novel treatment approaches. Host defense peptides (HDPs) are key components of the innate immune system. In this study, three novel avian β-defensins (AvBDs 2, 7, and 10) were characterized in pigeons and shown to possess direct antiviral activity against PPMV-1 in vitro. In addition, we evaluated the mRNA expression of these AvBDs and other immune-related genes in tissues of 2-month-old infected pigeons at 3 and 7 days postinfection. We observed that the expression of AvBD2 in the cecal tonsil, lungs, and proventriculus, as well as the expression of AvBD10 in the spleen, lungs, proventriculus, and kidneys, was upregulated in infected pigeons. Similarly, the expression of both Toll-like receptor 3 (TLR3) and TLR7 was increased in the spleen, trachea, and proventriculus, while TLR15 expression was increased only in the lungs of infected pigeons. In addition, inducible nitric oxide synthase (iNOS) expression was upregulated in the spleen, the bursa of Fabricius, the trachea, and the proventriculus of infected pigeons. Furthermore, we observed a high correlation between the expression of AvBD2 and the expression of either TLR7 or TLR15, as well as between AvBD10 expression and either TLR3 or TLR7 expression in respective tissues. The results suggest that PPMV-1 infection can induce innate host responses characterized by the activation of TLRs, particularly TLR3 and TLR7, AvBDs (2 and 10), and iNOS in pigeons. PMID:26162868

  6. Drug-induced mild therapeutic hypothermia obtained by administration of a transient receptor potential vanilloid type 1 agonist

    PubMed Central

    2010-01-01

    Background The use of mechanical/physical devices for applying mild therapeutic hypothermia is the only proven neuroprotective treatment for survivors of out of hospital cardiac arrest. However, this type of therapy is cumbersome and associated with several side-effects. We investigated the feasibility of using a transient receptor potential vanilloid type 1 (TRPV1) agonist for obtaining drug-induced sustainable mild hypothermia. Methods First, we screened a heterogeneous group of TRPV1 agonists and secondly we tested the hypothermic properties of a selected candidate by dose-response studies. Finally we tested the hypothermic properties in a large animal. The screening was in conscious rats, the dose-response experiments in conscious rats and in cynomologus monkeys, and the finally we tested the hypothermic properties in conscious young cattle (calves with a body weight as an adult human). The investigated TRPV1 agonists were administered by continuous intravenous infusion. Results Screening: Dihydrocapsaicin (DHC), a component of chili pepper, displayed a desirable hypothermic profile with regards to the duration, depth and control in conscious rats. Dose-response experiments: In both rats and cynomologus monkeys DHC caused a dose-dependent and immediate decrease in body temperature. Thus in rats, infusion of DHC at doses of 0.125, 0.25, 0.50, and 0.75 mg/kg/h caused a maximal ΔT (°C) as compared to vehicle control of -0.9, -1.5, -2.0, and -4.2 within approximately 1 hour until the 6 hour infusion was stopped. Finally, in calves the intravenous infusion of DHC was able to maintain mild hypothermia with ΔT > -3°C for more than 12 hours. Conclusions Our data support the hypothesis that infusion of dihydrocapsaicin is a candidate for testing as a primary or adjunct method of inducing and maintaining therapeutic hypothermia. PMID:20932337

  7. Association of the type 1 inositol (1,4,5)-trisphosphate receptor with 4.1N protein in neurons.

    PubMed

    Maximov, Anton; Tang, Tie Shan; Bezprozvanny, Ilya

    2003-02-01

    The type 1 inositol (1,4,5)-trisphosphate receptor (InsP(3)R1) is an intracellular calcium (Ca(2+)) release channel that plays an important role in neuronal function. In yeast two-hybrid screen of rat brain cDNA library with the InsP(3)R1 carboxy-terminal bait we isolated multiple clones of neuronal cytoskeletal protein 4.1N. We mapped the 4.1N-interaction site to a short fragment (50 amino acids) within the carboxy-terminal tail of the InsP(3)R1 and the InsP(3)R1-interaction site to the carboxy-terminal domain (CTD) of 4.1N. We established that InsP(3)R1 carboxy-terminal binds selectively to the CTDDelta alternatively spliced form of the 4.1N protein. In biochemical experiments we demonstrated that 4.1N and InsP(3)R1 specifically associate in vitro. We showed that both 4.1N and InsP(3)R1 were enriched in synaptic locations and immunoprecipitated the 4.1N-InsP(3)R1 complex from rat brain synaptosomes. In biochemical experiments we demonstrated a possibility of InsP(3)R1-4.1N-CASK-syndecan-2 quaternary complex formation. From our findings we hypothesize that InsP(3)R1-4.1N association may play a role in InsP(3)R1 localization or Ca(2+) signaling in neurons. PMID:12676536

  8. Toll-like receptor 9 polymorphisms influence mother-to-child transmission of human immunodeficiency virus type 1

    PubMed Central

    2010-01-01

    Background Toll-like receptors (TLRs) recognize pathogen-associated molecular patterns and play a crucial role in the host's innate immune response. Genetic variations in TLR genes may influence host-viral interactions and might impact upon the risk of mother-to-child transmission (MTCT) of Human Immunodeficiency Virus type 1 (HIV-1). The aim of this study was to investigate the influence of genetic variants of TLR 9 gene on MTCT. Methods Three hundred children (118 HIV-1-infected and 182 HIV-1-uninfected) born to HIV-1-infected mothers were studied. Single nucleotide polymorphisms (SNPs) NM_017442.2: c.4-44G > A (rs352139) and c.1635A > G (rs352140) of the TLR9 gene were genotyped by TaqMan allelic discrimination assay. Statistical analyses were performed using SNPStats program. Results When considered separately, neither of the two SNPs was significantly associated with risk of HIV-1 infection. However, the [A;A] and [G;G] haplotypes were associated with a higher risk of HIV-1 infection compared to the prevalent [G;A] haplotype [odds ratio (OR) = 3.16, 95% confidence interval (CI) 1.24-8.03, p = 0.016, and OR = 5.54, 95% CI 1.76-17.50, p = 0.004, respectively]. Conclusions Overall, results demonstrate a significant correlation between specific genetic variants of the TLR9 gene and risk of MTCT of HIV-1, thus confirming a critical role of innate immunity in perinatal HIV-1 infection. Strategies aimed at modulating innate immunity might be useful for future treatment of pediatric HIV-1 infection and AIDS. PMID:20500814

  9. Expression and regulation of scavenger receptor class B type 1 in the rat ovary and uterus during the estrous cycle.

    PubMed

    Wang, Yalei; Meng, Chenling; Wei, Quanwei; Shi, Fangxiong; Mao, Dagan

    2015-04-01

    Scavenger receptor class B type 1 (SR-B1) preferentially mediates the selective uptake of high density lipoprotein-cholesterol ester and the delivery of cholesterol for steroidogenesis. Although multiple analyses have investigated the function of SR-B1 in the liver, adrenal and ovary, its expression in rat ovary and uterus during the estrous cycle is lacking. In the present study, real-time PCR, western blot and immunohistochemistry (IHC) were used to investigate SR-B1 expression in the rat ovary and uterus during the estrous cycle. The results demonstrated that ovarian SR-B1 expression was in a stage-dependent manner, continuously increased from proestrus and kept elevated during metoestrus, while uterine SR-B1 expression decreased from proestrus to diestrus. To determine whether ovarian and uterine SR-B1 expression were affected by sex steroid hormones, immature rats were treated with 17 β-estradiol (E2), progesterone (P4), or their antagonists from postnatal days 24-26. Results showed that the levels of SR-B1 mRNA and protein were significantly up-regulated by E2 in both the ovary and uterus. IHC results showed that SR-B1 was primarily localized in the oocytes, theca internal cells (T-I) of follicles, interstitial cells (IC) as well as corpus luteum (CL), but not granulosa cells (GC) in the ovary during the estrous cycle. Uterine SR-B1 was highly expressed in the endometrial luminal epithelial cells (LEC) and glandular epithelial cells (GEC) as well as in the circular muscle (CM) cells, and weak staining in stromal cells (SC) through estrous cycle. Taken together, SR-B1 expression in the ovary and uterus across the estrous cycle demonstrate that SR-B1 may be involved in uterine function, follicular development as well as luteal function. PMID:25817199

  10. Iron overload causes osteoporosis in thalassemia major patients through interaction with transient receptor potential vanilloid type 1 (TRPV1) channels

    PubMed Central

    Rossi, Francesca; Perrotta, Silverio; Bellini, Giulia; Luongo, Livio; Tortora, Chiara; Siniscalco, Dario; Francese, Matteo; Torella, Marco; Nobili, Bruno; Di Marzo, Vincenzo; Maione, Sabatino

    2014-01-01

    The pathogenesis of bone resorption in β-thalassemia major is multifactorial and our understanding of the underlying molecular and cellular mechanisms remains incomplete. Considering the emerging importance of the endocannabinoid/endovanilloid system in bone metabolism, it may be instructive to examine a potential role for this system in the development of osteoporosis in patients with β-thalassemia major and its relationship with iron overload and iron chelation therapy. This study demonstrates that, in thalassemic-derived osteoclasts, tartrate-resistant acid phosphatase expression inversely correlates with femoral and lumbar bone mineral density, and directly correlates with ferritin levels and liver iron concentration. The vanilloid agonist resiniferatoxin dramatically reduces cathepsin K levels and osteoclast numbers in vitro, without affecting tartrate-resistant acid phosphatase expression. The iron chelators deferoxamine, deferiprone and deferasirox decrease both tartrate-resistant acid phosphatase and cathepsin K expression, as well as osteoclast activity. Taken together, these data show that transient receptor potential vanilloid type 1 activation/desensitization influences tartrate-resistant acid phosphatase expression and activity, and this effect is dependent on iron, suggesting a pivotal role for iron overload in the dysregulation of bone metabolism in patients with thalassemia major. Our applied pharmacology provides evidence for the potential of iron chelators to abrogate these effects by reducing osteoclast activity. Whether iron chelation therapy is capable of restoring bone health in humans requires further study, but the potential to provide dual benefits for patients with β-thalassemia major –preventing iron-overload and alleviating associated osteoporotic changes – is exciting. PMID:25216685

  11. The type-1 cannabinoid receptor modulates the hydroelectrolytic balance independently of the energy homeostasis during salt load.

    PubMed

    Vechiato, F M V; Rivas, P M S; Ruginsk, S G; Borges, B C; Elias, L L K; Antunes-Rodrigues, J

    2016-02-01

    Hydroelectrolytic imbalances, such as saline load (SL), trigger behavioral and neuroendocrine responses, such as thirst, hypophagia, vasopressin (AVP) and oxytocin (OT) release and hypothalamus–pituitary–adrenal (HPA) axis activation. To investigate the participation of the type-1 cannabinoid receptor (CB1R) in these homeostatic mechanisms,male adult Wistar rats were subjected to SL (0.3MNaCl) for four days. SL induced not only increases in the water intake and plasma levels of AVP, OT and corticosterone, as previously described, but also increases in CB1R expression in the lamina terminalis, which integrates sensory afferents, aswell as in the hypothalamus, the main integrative and effector area controlling hydroelectrolytic homeostasis. A more detailed analysis revealed that CB1R-positive terminals are in close apposition with not only axons but also dendrites and secretory granules of magnocellular neurons, particularly vasopressinergic cells. In satiated and euhydrated animals, the intracerebroventricular administration of the CB1R selective agonist ACEA (0.1 μg/5 μL) promoted hyperphagia, but this treatment did not reverse the hyperosmolality-induced hypophagia in the SL group. Furthermore, ACEA pretreatment potentiated water intake in the SL animals during rehydration as well as enhanced the corticosterone release and prevented the increase in AVP and OT secretion induced by SL. The same parameters were not changed by ACEA in the animals whose daily food intake was matched to that of the SL group (Pair-Fed). These data indicate that CB1Rs modulate the hydroelectrolytic balance independently of the food intake during sustained hyperosmolality and hypovolemia. PMID:26497248

  12. The Specific Monomer/Dimer Equilibrium of the Corticotropin-releasing Factor Receptor Type 1 Is Established in the Endoplasmic Reticulum

    PubMed Central

    Teichmann, Anke; Gibert, Arthur; Lampe, André; Grzesik, Paul; Rutz, Claudia; Furkert, Jens; Schmoranzer, Jan; Krause, Gerd; Wiesner, Burkhard; Schülein, Ralf

    2014-01-01

    G protein-coupled receptors (GPCRs) represent the most important drug targets. Although the smallest functional unit of a GPCR is a monomer, it became clear in the past decades that the vast majority of the receptors form dimers. Only very recently, however, data were presented that some receptors may in fact be expressed as a mixture of monomers and dimers and that the interaction of the receptor protomers is dynamic. To date, equilibrium measurements were restricted to the plasma membrane due to experimental limitations. We have addressed the question as to where this equilibrium is established for the corticotropin-releasing factor receptor type 1. By developing a novel approach to analyze single molecule fluorescence cross-correlation spectroscopy data for intracellular membrane compartments, we show that the corticotropin-releasing factor receptor type 1 has a specific monomer/dimer equilibrium that is already established in the endoplasmic reticulum (ER). It remains constant at the plasma membrane even following receptor activation. Moreover, we demonstrate for seven additional GPCRs that they are expressed in specific but substantially different monomer/dimer ratios. Although it is well known that proteins may dimerize in the ER in principle, our data show that the ER is also able to establish the specific monomer/dimer ratios of GPCRs, which sheds new light on the functions of this compartment. PMID:24966326

  13. Type 1 regulatory T cells specific for collagen type II as an efficient cell-based therapy in arthritis

    PubMed Central

    2014-01-01

    Introduction Regulatory T (Treg) cells play a crucial role in preventing autoimmune diseases and are an ideal target for the development of therapies designed to suppress inflammation in an antigen-specific manner. Type 1 regulatory T (Tr1) cells are defined by their capacity to produce high levels of interleukin 10 (IL-10), which contributes to their ability to suppress pathological immune responses in several settings. The aim of this study was to evaluate the therapeutic potential of collagen type II–specific Tr1 (Col-Treg) cells in two models of rheumatoid arthritis (RA) in mice. Methods Col-Treg clones were isolated and expanded from collagen-specific TCR transgenic mice. Their cytokine secretion profile and phenotype characterization were studied. The therapeutic potential of Col-Treg cells was evaluated after adoptive transfer in collagen-antibody– and collagen-induced arthritis models. The in vivo suppressive mechanism of Col-Treg clones on effector T-cell proliferation was also investigated. Results Col-Treg clones are characterized by their specific cytokine profile (IL-10highIL-4negIFN-γint) and mediate contact-independent immune suppression. They also share with natural Tregs high expression of GITR, CD39 and granzyme B. A single infusion of Col-Treg cells reduced the incidence and clinical symptoms of arthritis in both preventive and curative settings, with a significant impact on collagen type II antibodies. Importantly, injection of antigen-specific Tr1 cells decreased the proliferation of antigen-specific effector T cells in vivo significantly. Conclusions Our results demonstrate the therapeutic potential of Col-Treg cells in two models of RA, providing evidence that Col-Treg could be an efficient cell-based therapy for RA patients whose disease is refractory to current treatments. PMID:24886976

  14. Effects of Angiotensin II Receptor Signaling during Skin Wound Healing

    PubMed Central

    Takeda, Hikaru; Katagata, Yohtaro; Hozumi, Yutaka; Kondo, Shigeo

    2004-01-01

    The tissue angiotensin (Ang) system, which acts independently of the circulating renin Ang system, is supposed to play an important role in tissue repair in the heart and kidney. In the skin, the role of the system for wound healing has remained to be ascertained. Our study demonstrated that oral administration of selective AngII type-1 receptor (AT1) blocker suppressed keratinocyte re-epithelization and angiogenesis during skin wound healing in rats. Immunoprecipitation and Western blot analysis indicated the existence of AT1 and AngII type-2 receptor (AT2) in cultured keratinocytes and myofibroblasts. In a bromodeoxyuridine incorporation study, induction of AT1 signaling enhanced the incorporation into keratinocytes and myofibroblasts. Wound healing migration assays revealed that induction of AT1 signaling accelerated keratinocyte re-epithelization and myofibroblasts recovering. In these experiments, induction of AT2 signaling acted vice versa. Taken together, our study suggests that skin wound healing is regulated by balance of opposing signals between AT1 and AT2. PMID:15509535

  15. Biased Type 1 Cannabinoid Receptor Signaling Influences Neuronal Viability in a Cell Culture Model of Huntington Disease.

    PubMed

    Laprairie, Robert B; Bagher, Amina M; Kelly, Melanie E M; Denovan-Wright, Eileen M

    2016-03-01

    Huntington disease (HD) is an inherited, autosomal dominant, neurodegenerative disorder with limited treatment options. Prior to motor symptom onset or neuronal cell loss in HD, levels of the type 1 cannabinoid receptor (CB1) decrease in the basal ganglia. Decreasing CB1 levels are strongly correlated with chorea and cognitive deficit. CB1 agonists are functionally selective (biased) for divergent signaling pathways. In this study, six cannabinoids were tested for signaling bias in in vitro models of medium spiny projection neurons expressing wild-type (STHdh(Q7/Q7)) or mutant huntingtin protein (STHdh(Q111/Q111)). Signaling bias was assessed using the Black and Leff operational model. Relative activity [ΔlogR (τ/KA)] and system bias (ΔΔlogR) were calculated relative to the reference compound WIN55,212-2 for Gαi/o, Gαs, Gαq, Gβγ, and β-arrestin1 signaling following treatment with 2-arachidonoylglycerol (2-AG), anandamide (AEA), CP55,940, Δ(9)-tetrahydrocannabinol (THC), cannabidiol (CBD), and THC+CBD (1:1), and compared between wild-type and HD cells. The Emax of Gαi/o-dependent extracellular signal-regulated kinase (ERK) signaling was 50% lower in HD cells compared with wild-type cells. 2-AG and AEA displayed Gαi/o/Gβγ bias and normalized CB1 protein levels and improved cell viability, whereas CP55,940 and THC displayed β-arrestin1 bias and reduced CB1 protein levels and cell viability in HD cells. CBD was not a CB1 agonist but inhibited THC-dependent signaling (THC+CBD). Therefore, enhancing Gαi/o-biased endocannabinoid signaling may be therapeutically beneficial in HD. In contrast, cannabinoids that are β-arrestin-biased--such as THC found at high levels in modern varieties of marijuana--may be detrimental to CB1 signaling, particularly in HD where CB1 levels are already reduced. PMID:26700564

  16. Effect of HLA Class I and Class II Alleles on Progression From Autoantibody Positivity to Overt Type 1 Diabetes in Children With Risk-Associated Class II Genotypes

    PubMed Central

    Lipponen, Kati; Gombos, Zsofia; Kiviniemi, Minna; Siljander, Heli; Lempainen, Johanna; Hermann, Robert; Veijola, Riitta; Simell, Olli; Knip, Mikael; Ilonen, Jorma

    2010-01-01

    OBJECTIVE Class II alleles define the main HLA effect on type 1 diabetes, but there is an independent effect of certain class I alleles. Class II and class I molecules are differently involved in the initiation and effector phases of the immune response, suggesting that class I alleles would be important determinants in the rate of β-cell destruction. To test this hypothesis we analyzed the role of HLA class I and class II gene polymorphisms in the progression from diabetes-associated autoimmunity to clinical disease. RESEARCH DESIGN AND METHODS The effect of HLA-DR-DQ haplotypes and a panel of class I HLA-A and -B alleles on the progression from autoantibody seroconversion to clinical diabetes was studied in 249 children persistently positive for at least one biochemical diabetes-associated autoantibody in addition to islet cell autoantibody. RESULTS The progression to clinical disease was separately analyzed after the appearance of the first and the second persistent biochemical autoantibody using Cox regression. Multivariate analysis demonstrated a significant protective effect of the A*03 allele (odds ratio [OR] 0.61, P = 0.042 after the first and OR 0.55, P = 0.027 after the second autoantibody), whereas the B*39 allele had a promoting effect after seroconversion for the second autoantibody (OR 2.4, P = 0.014). When children with the DR3/DR4 genotype were separately analyzed, HLA-B*39 had a strong effect (OR 6.6, P = 0.004 and OR 7.5, P = 0.007, after the appearance of the first and the second autoantibody, respectively). The protective effect of A*03 was seen only among children without the DR3/DR4 combination. CONCLUSIONS These results confirm that class I alleles affect the progression of diabetes-associated autoimmunity and demonstrate interactions between class I and class II alleles. PMID:20739684

  17. Type 1 Diabetes in the Spanish Population: additional factors to Class II HLA-DR3 and -DR4

    PubMed Central

    Urcelay, Elena; Santiago, José L; de la Calle, Hermenegildo; Martínez, Alfonso; Méndez, Julián; Ibarra, José M; Maluenda, Carlos; Fernández-Arquero, Miguel; de la Concha, Emilio G

    2005-01-01

    Background The Major Histocompatibility Complex is the main genetic contributor to susceptibility to type 1 diabetes (T1D); genome-wide scans have consistently mapped increased predisposition to this region. The highest disease risk has been associated with HLA-DR3 and HLA-DR4. In particular, the DR3-positive ancestral haplotype 18.2 was reported as highly diabetogenic. We aimed to corroborate whether this haplotype increases the susceptibility conferred by the DQ2-DR3 alleles in a Mediterranean population. We also searched for additional susceptibility factors to the classic DQ2-DR3 and DQ8-DR4. Results Genetic MHC markers were analysed in a case-control study with 302 T1D patients and 529 ethnically matched controls. DR3-TNFa1b5 carrier rate was significantly higher in DR3-positive heterozygous T1D patients than in DR3-positive heterozygous controls (p = 0.0019; odds ratio OR [95% confidence interval CI] = 2.26 [1.3–3.93]). This data was confirmed analysing the allelic frequency, which includes the information corresponding to the DR3-homozygous individuals (p = 0.001; OR = 2.09) and by using the Arlequin software to check the DR3-positive haplotypes (p = 0.004;OR = 1.93). The present results provide strong evidence of a second susceptibility region in the ancestral haplotype 18.2 in the Spanish population. Moreover, we searched for T1D susceptibility factors in addition to the MHC classical ones, within the DR2-DQ6/DR3-DQ2/DR4-DQ8 negative population. Several genetic markers in both MHC class II (DQA1*0101-DQB1*0501 [p = 0.007;OR = 2.81], DQA1*0201-DQB1*0202 [p = 0.03; OR = 2.35]) and III (TNFa2b1 [p = 0.01 OR = 2.74], BAT-2*2 [p = 0.004; OR = 3.19]) were found. These different alleles associated with T1D were not independent and we observed linkage disequilibrium among them leading us to describe two new risk haplotypes (DQA1*0101-DQB1*0501-TNFa2b1 and DQA1*0201-DQB1*0202- BAT-2*2). Finally, we studied a T1D susceptibility/protection marker located in

  18. In situ single molecule detection of insulin receptors on erythrocytes from a type 1 diabetes ketoacidosis patient by atomic force microscopy.

    PubMed

    Zhang, Lu; Pi, Jiang; Shi, Qiping; Cai, Jiye; Yang, Peihui; Liang, Zhihong

    2015-11-01

    Type 1 diabetes is an insulin-dependent metabolic disorder always associated with ketoacidosis and a high morbidity rate in teenagers. The in situ single molecule detection of insulin receptors on healthy and diseased erythrocytes is helpful to understand the pathomechanism of type 1 diabetes ketoacidosis (T1-DKA), which would also benefit the diagnosis and treatment of T1-DKA. Here, we demonstrated, for the first time, the single molecule interaction between insulin and insulin receptor on erythrocytes from a healthy volunteer and a T1-DKA patient using high sensitivity atomic force microscopy (AFM) in PBS solution. The single molecule force results demonstrated the decreased binding force and binding probability between insulin and insulin receptor on T1-DKA erythrocytes, implying the deficit of insulin receptor functions in T1-DKA. The binding kinetic parameters calculated from dynamic force spectroscopy indicated that the insulin-insulin receptor complexes on T1-DKA erythrocytes were less stable than those from healthy volunteer. Using high resolution AFM imaging, a decreased roughness was found both in intact T1-DKA erythrocytes and in the purified membrane of T1-DKA erythrocytes, and an increased stiffness was also found in T1-DKA erythrocytes. Moreover, AFM, which was used to investigate the single molecule interactions between insulin-insulin receptor, cell surface ultrastructure and stiffness in healthy and diseased erythrocytes, was expected to develop into a potential nanotool for pathomechanism studies of clinical samples at the nanoscale. PMID:26405719

  19. The Angiotensin II Type 2 Receptor in Brain Functions: An Update

    PubMed Central

    Guimond, Marie-Odile; Gallo-Payet, Nicole

    2012-01-01

    Angiotensin II (Ang II) is the main active product of the renin-angiotensin system (RAS), mediating its action via two major receptors, namely, the Ang II type 1 (AT1) receptor and the type 2 (AT2) receptor. Recent results also implicate several other members of the renin-angiotensin system in various aspects of brain functions. The first aim of this paper is to summarize the current state of knowledge regarding the properties and signaling of the AT2 receptor, its expression in the brain, and its well-established effects. Secondly, we will highlight the potential role of the AT2 receptor in cognitive function, neurological disorders and in the regulation of appetite and the possible link with development of metabolic disorders. The potential utility of novel nonpeptide selective AT2 receptor ligands in clarifying potential roles of this receptor in physiology will also be discussed. If confirmed, these new pharmacological tools should help to improve impaired cognitive performance, not only through its action on brain microcirculation and inflammation, but also through more specific effects on neurons. However, the overall physiological relevance of the AT2 receptor in the brain must also consider the Ang IV/AT4 receptor. PMID:23320146

  20. FokI Polymorphism, Vitamin D Receptor, and Interleukin-1 Receptor Haplotypes Are Associated with Type 1 Diabetes in the Dalmatian Population

    PubMed Central

    Zemunik, Tatijana; Škrabić, Veselin; Boraska, Vesna; Diklić, Dijaneta; Terzić, Ivana Marinović; Čapkun, Vesna; Peruzović, Marijana; Terzić, Janoš

    2005-01-01

    Vitamin D and interleukin (IL)-1 have been suggested to function in the pathogenesis of type 1 diabetes mellitus (T1DM). Therefore, we examined the influence of gene polymorphisms in vitamin D receptor (VDR) and interleukin-1 receptor type I (IL-1-R1) on susceptibility to T1DM in the Dalmatian population of South Croatia. We genotyped 134 children with T1DM and 132 controls; for FokI polymorphism studies, we extended the control group to an additional 102 patients. The VDR gene polymorphism FokI displayed unequal distribution (P = 0.0049) between T1DM and control groups, with the ff genotype occurring more frequently in T1DM individuals whereas the VDR gene polymorphism Tru9I did not differ in frequency between studied groups. All tested polymorphisms of the IL-1-R1 gene [PstI, HinfI, and AluI (promoter region) and PstI-e (exon 1B region)] displayed no differences between cases and controls. Haplotype analysis of the VDR gene (FokI, BsmI, ApaI, TaqI, Tru9I) and of the IL-1-R1 gene (PstI, HinfI, AluI, PstI-e) found haplotypes VDR FbATu (P = 0.0388) and IL-1-R1 phap’ (P = 0.0419) to be more frequent in T1DM patients whereas the BatU haplotype occurred more often in controls (P = 0.0064). Our findings indicate that the VDR FokI polymorphism and several VDR and IL-1-R1 haplotypes are associated with susceptibility to T1DM in the Dalmatian population. PMID:16258158

  1. Inefficient fusion due to a lack of attachment receptor/co-receptor restricts productive human immunodeficiency virus type 1 infection in human hepatoma Huh7.5 cells.

    PubMed

    Fromentin, Rémi; Tardif, Mélanie R; Tremblay, Michel J

    2011-03-01

    Since the widespread use of the highly active antiretroviral therapy, the incidence of liver disease has increased to become a leading cause of death among human immunodeficiency virus type 1 (HIV-1)-infected individuals. It can be proposed that the ability of HIV-1 to infect hepatocytes could influence liver diseases. Although the presence of HIV-1 was identified in hepatocytes from HIV-1 seropositive patients, the susceptibility of hepatocytes to HIV-1 infection in vitro remains controversial. We present evidence here that human hepatoma cells are not productively infected with CD4-dependent HIV-1 strains because of inefficient fusion related to an absence of cell surface CD4 and CXCR4. However, these cells display an increased susceptibility to infection with a CD4-independent viral isolate through an interaction with galactosyl ceramide, an alternate receptor for HIV-1. This study provides further understanding of the susceptibility of human hepatocytes to HIV-1 infection. However, in vivo investigations are recommended to consolidate these data. PMID:21123542

  2. Association of rs5888 SNP in the scavenger receptor class B type 1 gene and serum lipid levels

    PubMed Central

    2012-01-01

    Background Bai Ku Yao is a special subgroup of the Yao minority in China. The present study was undertaken to detect the association of rs5888 single nucleotide polymorphism (SNP) in the scavenger receptor class B type 1 (SCARB1) gene and several environmental factors with serum lipid levels in the Guangxi Bai Ku Yao and Han populations. Methods A total of 598 subjects of Bai Ku Yao and 585 subjects of Han Chinese were randomly selected from our stratified randomized cluster samples. Genotypes of the SCARB1 rs5888 SNP were determined by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing. Results The levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein (Apo) AI were lower but ApoB was higher in Bai Ku Yao than in Han (P < 0.05-0.001). The frequencies of C and T alleles were 78.3% and 21.7% in Bai Ku Yao, and 73.7% and 26.3% in Han (P < 0.01); respectively. The frequencies of CC, CT and TT genotypes were 60.0%, 36.6% and 3.4% in Bai Ku Yao, and 54.2%, 39.0% and 6.8% in Han (P < 0.01); respectively. The subjects with TT genotype in both ethnic groups had lower HDL-C and ApoAI levels than the subjects with CC or CT genotype (P < 0.05 for all). Subgroup analyses showed that the subjects with TT genotype in Bai Ku Yao had lower HDL-C and ApoAI levels in males than the subjects with CC or CT genotype (P < 0.05 for all), and the T allele carriers had higher TC, LDL-C and ApoB levels in females than the T allele noncarriers (P < 0.05 for all). The participants with TT genotype in Han also had a lower tendency of HDL-C and ApoAI levels in males than the participants with CC or CT genotype, but the difference did not reach statistically significant (P = 0.063 and P = 0.086; respectively). The association of serum HDL-C and ApoAI levels and genotypes was confirmed by

  3. Localization of the ANG II type 2 receptor in the microcirculation of skeletal muscle

    NASA Technical Reports Server (NTRS)

    Nora, E. H.; Munzenmaier, D. H.; Hansen-Smith, F. M.; Lombard, J. H.; Greene, A. S.; Cowley, A. W. (Principal Investigator)

    1998-01-01

    Only functional studies have suggested the presence of the ANG II type 2 (AT2) receptor in the microcirculation. To determine the distribution of this receptor in the rat skeletal muscle microcirculation, a polyclonal rabbit anti-rat antiserum was developed and used for immunohistochemistry and Western blot analysis. The antiserum was prepared against a highly specific and antigenic AT2-receptor synthetic peptide and was validated by competition and sensitivity assays. Western blot analysis demonstrated a prominent, single band at approximately 40 kDa in cremaster and soleus muscle. Immunohistochemical analysis revealed a wide distribution of AT2 receptors throughout the skeletal muscle microcirculation in large and small microvessels. Microanatomic studies displayed an endothelial localization of the AT2 receptor, whereas dual labeling with smooth muscle alpha-actin also showed colocalization of the AT2 receptor with vascular smooth muscle cells. Other cells associated with the microvessels also stained positive for AT2 receptors. Briefly, this study confirms previous functional data and localizes the AT2 receptor to the microcirculation. These studies demonstrate that the AT2 receptor is present on a variety of vascular cell types and that it is situated in a fashion that would allow it to directly oppose ANG II type 1 receptor actions.

  4. Properly timed exposure to central ANG II prevents behavioral sensitization and changes in angiotensin receptor expression

    PubMed Central

    Santollo, Jessica; Whalen, Philip E.; Speth, Robert C.; Clark, Stewart D.

    2014-01-01

    Previous studies show that the angiotensin type 1 receptor (AT1R) is susceptible to rapid desensitization, but that more chronic treatments that stimulate ANG II lead to sensitization of several responses. It is unclear, however, if the processes of desensitization and sensitization interact. To test for differences in AT1R expression associated with single or repeated injections of ANG II, we measured AT1R mRNA in nuclei that control fluid intake of rats given ANG II either in a single injection or divided into three injections spaced 20 min apart. Rats given a single injection of ANG II had more AT1R mRNA in the subfornical organ (SFO) and the periventricular tissue surrounding the anteroventral third ventricle (AV3V) than did controls. The effect was not observed, however, when the same cumulative dose of ANG II was divided into multiple injections. Behavioral tests found that single daily injections of ANG II sensitized the dipsogenic response to ANG II, but a daily regimen of four injections did not cause sensitization. Analysis of 125I-Sar1-ANG II binding revealed a paradoxical decrease in binding in the caudal AV3V and dorsal median preoptic nucleus after 5 days of single daily injections of ANG II; however, this effect was absent in rats treated for 5 days with four daily ANG II injections. Taken together, these data suggest that a desensitizing treatment regimen prevents behavior- and receptor-level effects of repeated daily ANG II. PMID:25354729

  5. Characterization of the mouse cold-menthol receptor TRPM8 and vanilloid receptor type-1 VR1 using a fluorometric imaging plate reader (FLIPR) assay.

    PubMed

    Behrendt, H-J; Germann, T; Gillen, C; Hatt, H; Jostock, R

    2004-02-01

    1. TRPM8 (CMR1) is a Ca(2+)-permeable channel, which can be activated by low temperatures, menthol, eucalyptol and icilin. It belongs to the transient receptor potential (TRP) family, and therefore is related to vanilloid receptor type-1 (VR1, TRPV1). We tested whether substances which are structurally related to menthol, or which produce a cooling sensation, could activate TRPM8, and compared the responses of TRPM8 and VR1 to these ligands. 2. The effects of 70 odorants and menthol-related substances on recombinant mouse TRPM8 (mTRPM8), expressed in HEK293 cells, were examined using a FLIPR assay. In all, 10 substances (linalool, geraniol, hydroxycitronellal, WS-3, WS-23, FrescolatMGA, FrescolatML, PMD38, CoolactP and Cooling Agent 10) were found to be agonists. 3. The EC(50) values of the agonists defined their relative potencies: icilin (0.2+/-0.1 microM)>FrescolatML (3.3+/-1.5 microM) > WS-3 (3.7+/-1.7 microM) >(-)menthol (4.1+/-1.3 microM) >frescolatMAG (4.8+/-1.1 microM) > cooling agent 10 (6+/-2.2 microM) >(+)menthol (14.4+/-1.3 microM) > PMD38 (31+/-1.1 microM) > WS-23 (44+/-7.3 microM) > Coolact P (66+/-20 microM) > geraniol (5.9+/-1.6 mM) > linalool (6.7+/-2.0 mM) > eucalyptol (7.7+/-2.0 mM) > hydroxycitronellal (19.6+/-2.2 mM). 4. Known VR1 antagonists (BCTC, thio-BCTC and capsazepine) were also able to block the response of TRPM8 to menthol (IC(50): 0.8+/-1.0, 3.5+/-1.1 and 18+/-1.1 microM, respectively). 5. The Ca(2+) response of hVR1-transfected HEK293 cells to the endogenous VR1 agonist N-arachidonoyl-dopamine was potentiated by low pH. In contrast, menthol- and icilin-activated TRPM8 currents were suppressed by low pH. 6. In conclusion, in the present study, we identified 10 new agonists and three antagonists of TRPM8. We found that, in contrast to VR1, TRPM8 is inhibited rather than potentiated by protons. PMID:14757700

  6. Identification and Characterization of Novel Variations in Platelet G-Protein Coupled Receptor (GPCR) Genes in Patients Historically Diagnosed with Type 1 von Willebrand Disease

    PubMed Central

    Leo, Vincenzo C.; Sabi, Essa; Cunningham, Margaret R.; Eikenboom, Jeroen C.; Lethagen, Stefan; Schneppenheim, Reinhard; Goodeve, Anne C.; Watson, Steve P.; Mundell, Stuart J.; Daly, Martina E.

    2015-01-01

    The clinical expression of type 1 von Willebrand disease may be modified by co-inheritance of other mild bleeding diatheses. We previously showed that mutations in the platelet P2Y12 ADP receptor gene (P2RY12) could contribute to the bleeding phenotype in patients with type 1 von Willebrand disease. Here we investigated whether variations in platelet G protein-coupled receptor genes other than P2RY12 also contributed to the bleeding phenotype. Platelet G protein-coupled receptor genes P2RY1, F2R, F2RL3, TBXA2R and PTGIR were sequenced in 146 index cases with type 1 von Willebrand disease and the potential effects of identified single nucleotide variations were assessed using in silico methods and heterologous expression analysis. Seven heterozygous single nucleotide variations were identified in 8 index cases. Two single nucleotide variations were detected in F2R; a novel c.-67G>C transversion which reduced F2R transcriptional activity and a rare c.1063C>T transition predicting a p.L355F substitution which did not interfere with PAR1 expression or signalling. Two synonymous single nucleotide variations were identified in F2RL3 (c.402C>G, p.A134 =; c.1029 G>C p.V343 =), both of which introduced less commonly used codons and were predicted to be deleterious, though neither of them affected PAR4 receptor expression. A third single nucleotide variation in F2RL3 (c.65 C>A; p.T22N) was co-inherited with a synonymous single nucleotide variation in TBXA2R (c.6680 C>T, p.S218 =). Expression and signalling of the p.T22N PAR4 variant was similar to wild-type, while the TBXA2R variation introduced a cryptic splice site that was predicted to cause premature termination of protein translation. The enrichment of single nucleotide variations in G protein-coupled receptor genes among type 1 von Willebrand disease patients supports the view of type 1 von Willebrand disease as a polygenic disorder. PMID:26630678

  7. Identification and Characterization of Novel Variations in Platelet G-Protein Coupled Receptor (GPCR) Genes in Patients Historically Diagnosed with Type 1 von Willebrand Disease.

    PubMed

    Stockley, Jacqueline; Nisar, Shaista P; Leo, Vincenzo C; Sabi, Essa; Cunningham, Margaret R; Eikenboom, Jeroen C; Lethagen, Stefan; Schneppenheim, Reinhard; Goodeve, Anne C; Watson, Steve P; Mundell, Stuart J; Daly, Martina E

    2015-01-01

    The clinical expression of type 1 von Willebrand disease may be modified by co-inheritance of other mild bleeding diatheses. We previously showed that mutations in the platelet P2Y12 ADP receptor gene (P2RY12) could contribute to the bleeding phenotype in patients with type 1 von Willebrand disease. Here we investigated whether variations in platelet G protein-coupled receptor genes other than P2RY12 also contributed to the bleeding phenotype. Platelet G protein-coupled receptor genes P2RY1, F2R, F2RL3, TBXA2R and PTGIR were sequenced in 146 index cases with type 1 von Willebrand disease and the potential effects of identified single nucleotide variations were assessed using in silico methods and heterologous expression analysis. Seven heterozygous single nucleotide variations were identified in 8 index cases. Two single nucleotide variations were detected in F2R; a novel c.-67G>C transversion which reduced F2R transcriptional activity and a rare c.1063C>T transition predicting a p.L355F substitution which did not interfere with PAR1 expression or signalling. Two synonymous single nucleotide variations were identified in F2RL3 (c.402C>G, p.A134 =; c.1029 G>C p.V343 =), both of which introduced less commonly used codons and were predicted to be deleterious, though neither of them affected PAR4 receptor expression. A third single nucleotide variation in F2RL3 (c.65 C>A; p.T22N) was co-inherited with a synonymous single nucleotide variation in TBXA2R (c.6680 C>T, p.S218 =). Expression and signalling of the p.T22N PAR4 variant was similar to wild-type, while the TBXA2R variation introduced a cryptic splice site that was predicted to cause premature termination of protein translation. The enrichment of single nucleotide variations in G protein-coupled receptor genes among type 1 von Willebrand disease patients supports the view of type 1 von Willebrand disease as a polygenic disorder. PMID:26630678

  8. Mapping the binding surface of interleukin-8 complexed with an N-terminal fragment of the type 1 human interleukin-8 receptor.

    PubMed

    Clubb, R T; Omichinski, J G; Clore, G M; Gronenborn, A M

    1994-01-24

    Interleukin-8 and its receptors are key mediators of immune and inflammatory responses. Heteronuclear NMR spectroscopy has been utilized to map the binding surface on interleukin-8 (IL-8) for an N-terminal fragment of the human Type-1 IL-8 receptor. A peptide corresponding to residues 1-40 of the IL-8 type 1 receptor (IL8-r1) was titrated into a sample of uniformly 15N-labeled IL-8. IL8-r1 binds to IL-8 with a dissociation constant of 170 +/- 50 microM assuming the peptide binds with a stoichiometry of one peptide per IL-8 monomer, exchanges rapidly (> 900 s-1) between free and bound states, and selectively perturbs the chemical environment of several IL-8 residues. The binding surface on IL-8 suggested by our results is comprised of residues in strand beta 3 of the beta-sheet (Glu48 to Cys50), the turn preceding beta 3 (Ser44), the C-terminal alpha-helix (Val61) and the irregular N-terminal loop region (Thr12, Lys15, Phe17, His18, Lys20 and Phe21). The IL-8 dimer appears to present two symmetrical binding surfaces for the IL8-r1 peptide, suggesting two receptor peptides may bind per dimer. PMID:8307164

  9. Unexpected binding of an octapeptide to the angiotensin II receptor

    SciTech Connect

    Soffer, R.L.; Bandyopadhyay, S.; Rosenberg, E.; Hoeprich, P.; Teitelbaum, A.; Brunck, T.; Colby, C.B.; Gloff, C.

    1987-12-01

    An octapeptide, TBI-22 (Lys-Gly-Val-Tyr-Ile, His-Ala-Leu), inhibited binding of angiotensin II by a solubilized angiotensin receptor partially purified from rabbit liver. This inhibition appears to result from competition for binding to the same receptor. Radioiodinated TBI-22, like angiotensin II, bound to the solubilized receptor with an affinity such that the binding was inhibited 50% by unlabeled TBI-22 or angiotensin II at nanomolar concentrations. The binding reaction, like that for angiotensin II, required p-chloromercuriphenylsulfonic acid and was reversed in the presence of dithiothreitol. TBI-22 and angiotensin II share the sequence Val-Tyr-Ile-His; this tetrapeptide alone, however, did not inhibit binding of angiotensin II. Replacement of the tyrosine residue by aspartic acid in TBI-22 greatly reduced the ability of the peptide to compete with angiotensin II for binding, suggesting an important contribution of this residue to the configuration required for recognition by the receptor.

  10. Identification of angiotensin II receptor subtypes

    SciTech Connect

    Chiu, A.T.; Herblin, W.F.; McCall, D.E.; Ardecky, R.J.; Carini, D.J.; Duncia, J.V.; Pease, L.J.; Wong, P.C.; Wexler, R.R.; Johnson, A.L.; )

    1989-11-30

    We have demonstrated the existence of two distinct subtypes of the angiotensin II receptor in the rat adrenal gland using radioligand binding and tissue section autoradiography. The identification of the subtypes was made possible by the discovery of two structurally dissimilar, nonpeptide compounds, DuP 753 and EXP655, that show reciprocal selectivity for the two subtypes. In the rat adrenal cortex, DuP 753 inhibited 80% of the total AII binding with an IC50 value on the sensitive sites of 2 x 10(-8) M, while EXP655 displaced only 20%. In the rat adrenal medulla, EXP655 gave 90% inhibition of AII binding with an IC50 value of 3.0 x 10(-8) M, while DuP 753 was essentially inactive. The combination of the two compounds completely inhibited AII binding in both tissues.

  11. Role for the disulfide-bonded region of human immunodeficiency virus type 1 gp41 in receptor-triggered activation of membrane fusion function

    SciTech Connect

    Bellamy-McIntyre, Anna K.; Baer, Severine; Ludlow, Louise; Drummer, Heidi E.; Poumbourios, Pantelis

    2010-04-16

    The conserved disulfide-bonded region (DSR) of the human immunodeficiency virus type 1 (HIV-1) fusion glycoprotein, gp41, mediates association with the receptor-binding glycoprotein, gp120. Interactions between gp120, CD4 and chemokine receptors activate the fusion activity of gp41. The introduction of W596L and W610F mutations to the DSR of HIV-1{sub QH1549.13} blocked viral entry and hemifusion without affecting gp120-gp41 association. The fusion defect correlated with inhibition of CD4-triggered gp41 pre-hairpin formation, consistent with the DSR mutations having decoupled receptor-induced conformational changes in gp120 from gp41 activation. Our data implicate the DSR in sensing conformational changes in the gp120-gp41 complex that lead to fusion activation.

  12. Angiotensin type 1 (AT1) and type 2 (AT2) receptors mediate the increase in TGF-beta1 in thyroid hormone-induced cardiac hypertrophy.

    PubMed

    Diniz, G P; Carneiro-Ramos, M S; Barreto-Chaves, M L M

    2007-04-01

    Increased thyroid hormone (TH) levels are known to induce cardiac hypertrophy. Some studies have provided evidence for a functional link between angiotensin II (ANG II) and transforming growth factor beta1 (TGF-beta1) in the heart, both being able to also induce cardiac hypertrophy. However, the contribution of this growth factor activated directly by TH or indirectly by ANG II in cardiac hypertrophy development remains unknown. To analyze the possible role of TGF-beta1 in cardiac hypertrophy induced by TH and also to evaluate if the TGF-beta1 effect is mediated by ANG II receptors, we employed Wistar rats separated into control, hypothyroid (hypo) and hyperthyroid (T4 - 10) groups combined or not with ANG II receptor blockers (losartan or PD123319). Serum levels of T3 and T4, systolic pressure and heart rate confirmed the thyroid state of the groups. The T4 - 10 group presented a significant increase in cardiac TGF-beta1 levels; however, TGF-beta1 levels in the hypo group did not change in relation to the control. Inhibition of the increase in cardiac TGF-beta1 levels was observed in the groups treated with T4 in association with losartan or PD123319 when compared to the T4 - 10 group. These results demonstrate for the first time the TH-modulated induction of cardiac TGF-beta1 in cardiac hypertrophy, and that this effect is mediated by ANG II receptors. PMID:17206447

  13. Effects of γ-Aminobutyric Acid A Receptor Activation on Counterregulatory Responses to Subsequent Exercise in Individuals With Type 1 Diabetes.

    PubMed

    Hedrington, Maka S; Mikeladze, Maia; Tate, Donna B; Younk, Lisa M; Davis, Ian; Davis, Stephen N

    2016-09-01

    The effects of γ-aminobutyric acid (GABA) A receptor activation on physiologic responses during next-day exercise in type 1 diabetes are unknown. To test the hypothesis that GABA A activation with the benzodiazepine alprazolam would blunt counterregulatory responses during subsequent exercise, 29 (15 male, 14 female) individuals with type 1 diabetes (HbA1c 7.8 ± 1%) were studied during separate 2-day protocols. Day 1 consisted of morning and afternoon 2-h euglycemic or 2.9 mmol/L hypoglycemic clamps with or without 1 mg alprazolam given 30 min before each clamp. Day 2 consisted of a 90-min euglycemic cycling exercise at 50% VO2max Tritiated glucose was used to measure glucose kinetics. Despite equivalent day 2 insulin (93 ± 6 pmol/L) and glucose levels (5.3 ± 0.1 mmol/L), plasma epinephrine, norepinephrine, glucagon, cortisol, and growth hormone responses were similarly reduced after alprazolam or day 1 hypoglycemia compared with euglycemic control. Endogenous glucose production, lipolysis (glycerol, nonesterified fatty acid), and glycogenolysis (lactate) were also reduced during day 2 exercise after day 1 GABA A activation. We conclude that activation of GABA A receptors with alprazolam can result in widespread neuroendocrine, autonomic nervous system, and metabolic counterregulatory failure during subsequent submaximal exercise and may increase the risk of exercise-associated hypoglycemia in individuals with type 1 diabetes. PMID:27217489

  14. Novel Ex Vivo Culture Method for the Study of Dupuytren's Disease: Effects of TGFβ Type 1 Receptor Modulation by Antisense Oligonucleotides

    PubMed Central

    Karkampouna, Sofia; Kruithof, Boudewijn PT; Kloen, Peter; Obdeijn, Miryam C; van der Laan, Annelies MA; Tanke, Hans J; Kemaladewi, Dwi U; Hoogaars, Willem MH; ‘t Hoen, Peter AC; Aartsma-Rus, Annemieke; Clark, Ian M; ten Dijke, Peter; Goumans, Marie-José; Kruithof-de Julio, Marianna

    2014-01-01

    Dupuytren's disease (DD) is a benign fibroproliferative disease of the hand. It is characterized by the excessive production of extracellular matrix (ECM) proteins, which form a strong fibrous tissue between the handpalm and fingers, permanently disrupting the fine movement ability. The major contractile element in DD is the myofibroblast (MFB). This cell has both fibroblast and smooth muscle cell-type characteristics and causes pathological collagen deposition. MFBs generate contractile forces that are transmitted to the surrounding collagen matrix. Μajor profibrotic factors are members of the transforming growth factor-β (TGFβ) pathway which directly regulate the expression levels of several fibrous proteins such as collagen type 1, type 3, and α-smooth muscle actin. Molecular modulation of this signaling pathway could serve as a therapeutic approach. We, therefore, have developed an ex vivo “clinical trial” system to study the properties of intact, patient-derived resection specimens. In these culture conditions, Dupuytren's tissue retains its three-dimensional (3D) structure and viability. As a novel antifibrotic therapeutic approach, we targeted TGFβ type 1 receptor (also termed activin receptor-like kinase 5) expression in cultured Dupuytren's specimens by antisense oligonucleotide-mediated exon skipping. Antisense oligonucleotides targeting activin receptor-like kinase 5 showed specific reduction of ECM and potential for clinical application. PMID:24448195

  15. Angiotensin and mineralocorticoid receptor antagonism attenuates cardiac oxidative stress in angiotensin II-infused rats.

    PubMed

    Minas, Jacqueline N; Thorwald, Max A; Conte, Debra; Vázquez-Medina, Jose-Pablo; Nishiyama, Akira; Ortiz, Rudy M

    2015-11-01

    Angiotensin II (Ang II) and aldosterone contribute to hypertension, oxidative stress and cardiovascular damage, but the contributions of aldosterone during Ang II-dependent hypertension are not well defined because of the difficulty to assess each independently. To test the hypothesis that during Ang II infusion, oxidative and nitrosative damage is mediated through both the mineralocorticoid receptor (MR) and angiotensin type 1 receptor (AT1), five groups of Sprague-Dawley rats were studied: (i) control; (ii) Ang II infused (80 ng/min × 28 days); (iii) Ang II + AT1 receptor blocker (ARB; 10 mg losartan/kg per day × 21 days); (iv) Ang II + mineralocorticoid receptor (MR) antagonist (Epl; 100 mg eplerenone/day × 21 days); and (v) Ang II + ARB + Epl (Combo; × 21 days). Both ARB and combination treatments completely alleviated the Ang II-induced hypertension, whereas eplerenone treatment only prolonged the onset of the hypertension. Eplerenone treatment exacerbated the Ang II-mediated increase in plasma and heart aldosterone 2.3- and 1.8-fold, respectively, while ARB treatment reduced both. Chronic MR blockade was sufficient to ameliorate the AT1-mediated increase in oxidative damage. All treatments normalized protein oxidation (nitrotyrosine) levels; however, only ARB and Combo treatments completely reduced lipid peroxidation (4-hydroxynonenal) to control levels. Collectively, these data suggest that receptor signalling, and not the elevated arterial blood pressure, is the principal culprit in the oxidative stress-associated cardiovascular damage in Ang II-dependent hypertension. PMID:26234762

  16. Pharmacological enhancement of mGlu1 metabotropic glutamate receptors causes a prolonged symptomatic benefit in a mouse model of spinocerebellar ataxia type 1

    PubMed Central

    2013-01-01

    Background Spinocerebellar ataxia type 1 (SCA1) is a genetic disorder characterized by severe ataxia associated with progressive loss of cerebellar Purkinje cells. The mGlu1 metabotropic glutamate receptor plays a key role in mechanisms of activity-dependent synaptic plasticity in the cerebellum, and its dysfunction is linked to the pathophysiology of motor symptoms associated with SCA1. We used SCA1 heterozygous transgenic mice (Q154/Q2) as a model for testing the hypothesis that drugs that enhance mGlu1 receptor function may be good candidates for the medical treatment of SCA1. Results Symptomatic 30-week old SCA1 mice showed reduced mGlu1 receptor mRNA and protein levels in the cerebellum. Interestingly, these mice also showed an intense expression of mGlu5 receptors in cerebellar Purkinje cells, which normally lack these receptors. Systemic treatment of SCA1 mice with the mGlu1 receptor positive allosteric modulator (PAM), Ro0711401 (10 mg/kg, s.c.), caused a prolonged improvement of motor performance on the rotarod and the paw-print tests. A single injection of Ro0711401 improved motor symptoms for several days, and no tolerance developed to the drug. In contrast, the mGlu5 receptor PAM, VU0360172 (10 mg/kg, s.c.), caused only a short-lasting improvement of motor symptoms, whereas the mGlu1 receptor antagonist, JNJ16259685 (2.5 mg/kg, i.p.), further impaired motor performance in SCA1 mice. The prolonged symptomatic benefit caused by Ro0711401 outlasted the time of drug clearance from the cerebellum, and was associated with neuroadaptive changes in the cerebellum, such as a striking reduction of the ectopically expressed mGlu5 receptors in Purkinje cells, increases in levels of total and Ser880-phosphorylated GluA2 subunit of AMPA receptors, and changes in the length of spines in the distal dendrites of Purkinje cells. Conclusions These data demonstrate that pharmacological enhancement of mGlu1 receptors causes a robust and sustained motor improvement in SCA

  17. Induction of Innate Immune Response through Toll-like Receptor 2 and Dectin 1 prevents type 1 diabetes1

    PubMed Central

    Karumuthil-Melethil, Subha; Perez, Nicolas; Li, Ruobing; Vasu, Chenthamarakshan

    2008-01-01

    Studies have suggested a correlation between the decline in infectious diseases and increase in the incidence of T1D in developed countries. Pathogens influence the disease outcome through innate immune receptors such as toll-like receptors (TLRs). Here, we report the effect of ligation of TLR2 and dectin 1 on APCs, and the influence of innate immune response induced through these receptors on T1D. Exposure of APCs of non-obese diabetic (NOD) mice to zymosan, a fungal cell-wall component that is known to interact with TLR2 and dectin 1, resulted in the release of significant amounts of IL-10, TGF-β1, IL-2, and TNF-α. Treatment of pre- and early-hyperglycemic mice with zymosan resulted in suppression of insulitis leading to a significant delay in hyperglycemia. Importantly, T cells from zymosan treated mice showed reduced ability to induce diabetes in NOD-Scid mice compared to control T cells. Zymosan treatment induced suppression of T1D was associated with an increase in the CD62Lhigh T cell frequencies and enhanced suppressor function of CD4+CD25+ Tregs. Further, activation by anti-CD3-Ab induced larger amounts of TGF-β1 and/or IL-10 production by CD4+CD25+ and CD4+CD25- T cells from zymosan treated mice. These results show that innate immune response through TLR2 and dectin 1 results in suppressor cytokine production by APCs, and promotes regulatory function of T cells. Our study demonstrates the possible involvement of signaling through innate immune receptors such as TLR2 and dectin 1 in reduced T1D incidence under the conditions of low hygiene, and the potential of targeting them for treating T1D. PMID:19050249

  18. Deletion of the type-1 interferon receptor in APPSWE/PS1ΔE9 mice preserves cognitive function and alters glial phenotype.

    PubMed

    Minter, Myles R; Moore, Zachery; Zhang, Moses; Brody, Kate M; Jones, Nigel C; Shultz, Sandy R; Taylor, Juliet M; Crack, Peter J

    2016-01-01

    A neuro-inflammatory response is evident in Alzheimer's disease (AD), yet the precise mechanisms by which neuro-inflammation influences the progression of Alzheimer's disease (AD) remain poorly understood. Type-1 interferons (IFNs) are master regulators of innate immunity and have been implicated in multiple CNS disorders, however their role in AD progression has not yet been fully investigated. Hence, we generated APPSWE/PS1ΔE9 mice lacking the type-1 IFN alpha receptor-1 (IFNAR1, APPSWE/PS1ΔE9 x IFNAR1(-/-)) aged to 9 months to investigate the role of type-1 IFN signaling in a well-validated model of AD. APPSWE/PS1ΔE9 x IFNAR1(-/-) mice displayed a modest reduction in Aβ monomer levels, despite maintenance of plaque deposition. This finding correlated with partial rescue of spatial learning and memory impairments in the Morris water maze in comparison to APPSWE/PS1ΔE9 mice. Q-PCR identified a reduced type-1 IFN response and modulated pro-inflammatory cytokine secretion in APPSWE/PS1ΔE9 x IFNAR1(-/-) mice compared to APPSWE/PS1ΔE9 mice. Interestingly, immunohistochemistry displayed enhanced astrocyte reactivity but attenuated microgliosis surrounding amyloid plaque deposits in APPSWE/PS1ΔE9 x IFNAR1(-/-) mice in comparison to APPSWE/PS1ΔE9 mice. These APPSWE/PS1ΔE9 x IFNAR1(-/-) microglial populations demonstrated an anti-inflammatory phenotype that was confirmed in vitro by soluble Aβ1-42 treatment of IFNAR1(-/-) primary glial cultures. Our findings suggest that modulating neuro-inflammatory responses by suppressing type-1 IFN signaling may provide therapeutic benefit in AD. PMID:27400725

  19. Histamine induces NF-κB controlled cytokine secretion by orbital fibroblasts via histamine receptor type-1.

    PubMed

    Virakul, Sita; Phetsuksiri, Tanachaporn; van Holten-Neelen, Conny; Schrijver, Benjamin; van Steensel, Leendert; Dalm, Virgil A S H; Paridaens, Dion; van den Bosch, Willem A; van Hagen, P Martin; Dik, Willem A

    2016-06-01

    Mast cells and their products are likely to be involved in regulating orbital fibroblast activity in Graves' Ophthalmopathy (GO). Histamine is abundantly present in granules of mast cells and is released upon mast cell activation. However, the effect of histamine on orbital fibroblasts has not been examined so far. Orbital tissues from GO patients and controls were analyzed for the presence of mast cells using toluidine blue staining and immunohistochemical detection of CD117 (stem cell factor receptor). Orbital fibroblasts were cultured from GO patients and healthy controls, stimulated with histamine and cytokines (IL-6, IL-8, CCL2, CCL5, CCL7, CXCL10 and CXCL11) were measured in culture supernatants. Also hyaluronan levels were measured in culture supernatants and hyaluronan synthase (HAS) and hyaluronidase (HYAL) gene expression levels were determined. In addition, histamine receptor subtype gene expression levels were examined as well as the effect of the histamine receptor-1 (HRH1) antagonist loratadine and NF-κB inhibitor SC-514 on histamine-induced cytokine production. Mast cell numbers were increased in GO orbital tissues. Histamine stimulated the production of IL-6, IL-8 and CCL2 by orbital fibroblasts, while it had no effect on the production of CCL5, CCL7, CXCL10, CXCL11 and hyaluronan. Orbital fibroblasts expressed HRH1 and loratadine and SC-514 both blocked histamine-induced IL-6, IL-8 and CCL2 production by orbital fibroblasts. In conclusion, this study demonstrates that histamine can induce the production of NF-κB controlled-cytokines by orbital fibroblasts, which supports a role for mast cells in GO. PMID:27170049

  20. Identification of novel inhibitors of the transforming growth factor beta1 (TGF-beta1) type 1 receptor (ALK5).

    PubMed

    Callahan, James F; Burgess, Joelle L; Fornwald, James A; Gaster, Laramie M; Harling, John D; Harrington, Frank P; Heer, Jag; Kwon, Chet; Lehr, Ruth; Mathur, A; Olson, Barbara A; Weinstock, Joseph; Laping, Nicholas J

    2002-02-28

    Screening of our internal compound collection for inhibitors of the transforming growth factor beta1 (TGF-beta1) type I receptor (ALK5) identified several hits. Optimization of the dihydropyrroloimidazole hit 2 by introduction of a 2-pyridine and 3,4-methylenedioxyphenyl group gave 7, a selective ALK5 inhibitor. With this information, optimization of the triarylimidazole hit 8 gave the selective inhibitor 14, which inhibits TGF-beta1-induced fibronectin mRNA formation while displaying no measurable cytotoxicity in the 48 h XTT assay. PMID:11855979

  1. Galactosyl ceramide or a derivative is an essential component of the neural receptor for human immunodeficiency virus type 1 envelope glycoprotein gp120.

    PubMed Central

    Bhat, S; Spitalnik, S L; Gonzalez-Scarano, F; Silberberg, D H

    1991-01-01

    This report demonstrates that galactosyl ceramide (GalCer) or a molecule derived from it may serve as an alternative receptor for human immunodeficiency virus in the nervous system. Recombinant gp120, an envelope glycoprotein of human immunodeficiency virus type 1, specifically binds to GalCer and its derivatives. This specificity was studied by inhibiting binding of radioiodinated gp120 to GalCer with antibodies to GalCer, antibodies to gp120, and an excess of unlabeled gp120. Binding activity was also removed by absorbing gp120 with liposomes containing GalCer. In addition, studies using natural and semisynthetic lipids indicate that the linkage between galactose and ceramide is essential for binding. The significance of an alternative receptor for human immunodeficiency virus in the nervous system is discussed. Images PMID:1871126

  2. Structural insights into transient receptor potential vanilloid type 1 (TRPV1) from homology modeling, flexible docking, and mutational studies

    PubMed Central

    Lee, Jin Hee; Lee, Yoonji; Ryu, HyungChul; Kang, Dong Wook; Lee, Jeewoo; Lazar, Jozsef; Pearce, Larry V.; Pavlyukovets, Vladimir A.; Blumberg, Peter M.; Choi, Sun

    2012-01-01

    The transient receptor potential vanilloid subtype 1 (TRPV1) is a non-selective cation channel composed of four monomers with six transmembrane helices (TM1-TM6). TRPV1 is found in the central and peripheral nervous system, and it is an important therapeutic target for pain relief. We describe here the construction of a tetrameric homology model of rTRPV1. We experimentally evaluated by mutational analysis the contribution of residues of rat TRPV1 (rTRPV1) contributing to ligand binding by the prototypical TRPV1 agonists capsaicin and resiniferatoxin. We then performed docking analysis using our homology model. The docking results with capsaicin and RTX showed that our homology model was reliable, affording good agreement with our mutation data. Additionally, the binding mode of a simplified RTX (sRTX) ligand as predicted by the modeling agreed well with those of capsaicin and RTX, accounting for the high binding affinity of the sRTX ligand for TRPV1. Through the homology modeling, docking and mutational studies, we obtained important insights into the ligand-receptor interactions at the molecular level which should prove of value in the design of novel TRPV1 ligands. PMID:21448716

  3. A switch in G protein coupling for type 1 corticotropin-releasing factor receptors promotes excitability in epileptic brains.

    PubMed

    Narla, Chakravarthi; Scidmore, Tanner; Jeong, Jaymin; Everest, Michelle; Chidiac, Peter; Poulter, Michael O

    2016-01-01

    Anxiety and stress increase the frequency of epileptic seizures. These behavioral states induce the secretion of corticotropin-releasing factor (CRF), a 40-amino acid neuropeptide neurotransmitter that coordinates many behavioral responses to stress in the central nervous system. In the piriform cortex, which is one of the most seizurogenic regions of the brain, CRF normally dampens excitability. By contrast, CRF increased the excitability of the piriform cortex in rats subjected to kindling, a model of temporal lobe epilepsy. In nonkindled rats, CRF activates its receptor, a G protein (heterotrimeric guanosine triphosphate-binding protein)-coupled receptor, and signals through a Gαq/11-mediated pathway. After seizure induction, CRF signaling occurred through a pathway involving Gαs This change in signaling was associated with reduced abundance of regulator of G protein signaling protein type 2 (RGS2), which has been reported to inhibit Gαs-dependent signaling. RGS2 knockout mice responded to CRF in a similar manner as epileptic rats. These observations indicate that seizures produce changes in neuronal signaling that can increase seizure occurrence by converting a beneficial stress response into an epileptic trigger. PMID:27303056

  4. Human T lymphotropic virus type-1 p30II alters cellular gene expression to selectively enhance signaling pathways that activate T lymphocytes

    PubMed Central

    Michael, Bindhu; Nair, Amrithraj M; Hiraragi, Hajime; Shen, Lei; Feuer, Gerold; Boris-Lawrie, Kathleen; Lairmore, Michael D

    2004-01-01

    Background Human T-lymphotropic virus type-1 (HTLV-1) is a deltaretrovirus that causes adult T-cell leukemia/lymphoma and is implicated in a variety of lymphocyte-mediated disorders. HTLV-1 contains both regulatory and accessory genes in four pX open reading frames. pX ORF-II encodes two proteins, p13II and p30II, which are incompletely defined in the virus life cycle or HTLV-1 pathogenesis. Proviral clones of the virus with pX ORF-II mutations diminish the ability of the virus to maintain viral loads in vivo. Exogenous expression of p30II differentially modulates CREB and Tax-responsive element-mediated transcription through its interaction with CREB-binding protein/p300 and represses tax/rex RNA nuclear export. Results Herein, we further characterized the role of p30II in regulation of cellular gene expression, using stable p30II expression system employing lentiviral vectors to test cellular gene expression with Affymetrix U133A arrays, representing ~33,000 human genes. Reporter assays in Jurkat T cells and RT-PCR in Jurkat and primary CD4+ T-lymphocytes were used to confirm selected gene expression patterns. Our data reveals alterations of interrelated pathways of cell proliferation, T-cell signaling, apoptosis and cell cycle in p30II expressing Jurkat T cells. In all categories, p30II appeared to be an overall repressor of cellular gene expression, while selectively increasing the expression of certain key regulatory genes. Conclusions We are the first to demonstrate that p30II, while repressing the expression of many genes, selectively activates key gene pathways involved in T-cell signaling/activation. Collectively, our data suggests that this complex retrovirus, associated with lymphoproliferative diseases, relies upon accessory gene products to modify cellular environment to promote clonal expansion of the virus genome and thus maintain proviral loads in vivo. PMID:15560845

  5. Parathyroid Hormone (PTH)/PTH-related Peptide Type 1 Receptor (PPR) Signaling in Osteocytes Regulates Anabolic and Catabolic Skeletal Responses to PTH*

    PubMed Central

    Saini, Vaibhav; Marengi, Dean A.; Barry, Kevin J.; Fulzele, Keertik S.; Heiden, Erica; Liu, Xiaolong; Dedic, Christopher; Maeda, Akira; Lotinun, Sutada; Baron, Roland; Pajevic, Paola Divieti

    2013-01-01

    Parathyroid hormone (PTH) is the only Food and Drug Administration-approved anabolic agent to treat osteoporosis; however, the cellular targets of PTH action in bone remain controversial. PTH modulates bone turnover by binding to the PTH/PTH-related peptide (PTHrP) type 1 receptor (PPR), a G-protein-coupled receptor highly expressed in bone and kidneys. Osteocytes, the most abundant cells in adult bone, also express PPR. However, the physiological relevance of PPR signaling in osteocytes remains to be elucidated. Toward this goal, we generated mice with PPR deletion in osteocytes (Ocy-PPRKO). Skeletal analysis of these mice revealed a significant increase in bone mineral density and trabecular and cortical bone parameters. Osteoblast activities were reduced in these animals, as demonstrated by decreased collagen type I α1 mRNA and receptor activator of NF-κB ligand (RANKL) expression. Importantly, when subjected to an anabolic or catabolic PTH regimen, Ocy-PPRKO animals demonstrated blunted skeletal responses. PTH failed to suppress SOST/Sclerostin or induce RANKL expression in Ocy-PPRKO animals compared with controls. In vitro, osteoclastogenesis was significantly impaired in Ocy-PPRKO upon PTH administration, indicating that osteocytes control osteoclast formation through a PPR-mediated mechanism. Taken together, these data indicate that PPR signaling in osteocytes is required for bone remodeling, and receptor signaling in osteocytes is needed for anabolic and catabolic skeletal responses. PMID:23729679

  6. Neurorestoration after traumatic brain injury through angiotensin II receptor blockage.

    PubMed

    Villapol, Sonia; Balarezo, María G; Affram, Kwame; Saavedra, Juan M; Symes, Aviva J

    2015-11-01

    See Moon (doi:10.1093/awv239) for a scientific commentary on this article.Traumatic brain injury frequently leads to long-term cognitive problems and physical disability yet remains without effective therapeutics. Traumatic brain injury results in neuronal injury and death, acute and prolonged inflammation and decreased blood flow. Drugs that block angiotensin II type 1 receptors (AT1R, encoded by AGTR1) (ARBs or sartans) are strongly neuroprotective, neurorestorative and anti-inflammatory. To test whether these drugs may be effective in treating traumatic brain injury, we selected two sartans, candesartan and telmisartan, of proven therapeutic efficacy in animal models of brain inflammation, neurodegenerative disorders and stroke. Using a validated mouse model of controlled cortical impact injury, we determined effective doses for candesartan and telmisartan, their therapeutic window, mechanisms of action and effect on cognition and motor performance. Both candesartan and telmisartan ameliorated controlled cortical impact-induced injury with a therapeutic window up to 6 h at doses that did not affect blood pressure. Both drugs decreased lesion volume, neuronal injury and apoptosis, astrogliosis, microglial activation, pro-inflammatory signalling, and protected cerebral blood flow, when determined 1 to 3 days post-injury. Controlled cortical impact-induced cognitive impairment was ameliorated 30 days after injury only by candesartan. The neurorestorative effects of candesartan and telmisartan were reduced by concomitant administration of the peroxisome proliferator-activated receptor gamma (PPARγ, encoded by PPARG) antagonist T0070907, showing the importance of PPARγ activation for the neurorestorative effect of these sartans. AT1R knockout mice were less vulnerable to controlled cortical impact-induced injury suggesting that the sartan's blockade of the AT1R also contributes to their efficacy. This study strongly suggests that sartans with dual AT1R blocking and

  7. Sirolimus for progressive neurofibromatosis type 1–associated plexiform neurofibromas: a Neurofibromatosis Clinical Trials Consortium phase II study

    PubMed Central

    Weiss, Brian; Widemann, Brigitte C.; Wolters, Pamela; Dombi, Eva; Vinks, Alexander; Cantor, Alan; Perentesis, John; Schorry, Elizabeth; Ullrich, Nicole; Gutmann, David H.; Tonsgard, James; Viskochil, David; Korf, Bruce; Packer, Roger J.; Fisher, Michael J.

    2015-01-01

    Background Plexiform neurofibromas (PNs) are benign peripheral nerve sheath tumors that arise in one-third of individuals with neurofibromatosis type 1 (NF1). They may cause significant disfigurement, compression of vital structures, neurologic dysfunction, and/or pain. Currently, the only effective management strategy is surgical resection. Converging evidence has demonstrated that the NF1 tumor suppressor protein, neurofibromin, negatively regulates activity in the mammalian Target of Rapamycin pathway. Methods We employed a 2-strata clinical trial design. Stratum 1 included subjects with inoperable, NF1-associated progressive PN and sought to determine whether sirolimus safely and tolerably increases time to progression (TTP). Volumetric MRI analysis conducted at regular intervals was used to determine TTP relative to baseline imaging. Results The estimated median TTP of subjects receiving sirolimus was 15.4 months (95% CI: 14.3–23.7 mo), which was significantly longer than 11.9 months (P < .001), the median TTP of the placebo arm of a previous PN clinical trial with similar eligibility criteria. Conclusions This study demonstrated that sirolimus prolongs TTP by almost 4 months in patients with NF1-associated progressive PN. Although the improvement in TTP is modest, given the lack of significant or frequent toxicity and the availability of few other treatment options, the use of sirolimus to slow the growth of progressive PN could be considered in select patients. PMID:25314964

  8. Calcium mobilization from fish scales is mediated by parathyroid hormone related protein via the parathyroid hormone type 1 receptor.

    PubMed

    Rotllant, J; Redruello, B; Guerreiro, P M; Fernandes, H; Canario, A V M; Power, D M

    2005-12-15

    The scales of bony fish represent a significant reservoir of calcium but little is known about their contribution, as well as of bone, to calcium balance and how calcium deposition and mobilization are regulated in calcified tissues. In the present study we report the action of parathyroid hormone-related protein (PTHrP) on calcium mobilization from sea bream (Sparus auratus) scales in an in vitro bioassay. Ligand binding studies of piscine 125I-(1-35(tyr))PTHrP to the membrane fraction of isolated sea bream scales revealed the existence of a single PTH receptor (PTHR) type. RT-PCR of fish scale cDNA using specific primers for two receptor types found in teleosts, PTH1R, and PTH3R, showed expression only of PTH1R. The signalling mechanisms mediating binding of the N-terminal amino acid region of PTHrP were investigated. A synthetic peptide (10(-8) M) based on the N-terminal 1-34 amino acid residues of Fugu rubripes PTHrP strongly stimulated cAMP synthesis and [3H]myo-inositol incorporation in sea bream scales. However, peptides (10(-8) M) with N-terminal deletions, such as (2-34), (3-34) and (7-34)PTHrP, were defective in stimulating cAMP production but stimulated [3H]myo-inositol incorporation. (1-34)PTHrP induced significant osteoclastic activity in scale tissue as indicated by its stimulation of tartrate-resistant acid phosphatase. In contrast, (7-34)PTHrP failed to stimulate the activity of this enzyme. This activity could also be abolished by the adenylyl cyclase inhibitor SQ-22536, but not by the phospholipase C inhibitor U-73122. The results of the study indicate that one mechanism through which N-terminal (1-34)PTHrP stimulates osteoclastic activity of sea bream scales, is through PTH1R and via the cAMP/AC intracellular signalling pathway. It appears, therefore, that fish scales can act as calcium stores and that (1-34)PTHrP regulates calcium mobilization from them; it remains to be established if this mechanism contributes to calcium homeostasis in vivo

  9. Cannabinoid receptor type 1 agonist ACEA improves motor recovery and protects neurons in ischemic stroke in mice.

    PubMed

    Caltana, Laura; Saez, Trinidad Maria; Aronne, María Paula; Brusco, Alicia

    2015-11-01

    Brain ischemia produces neuronal cell death and the recruitment of pro-inflammatory cells. In turn, the search for neuroprotection against this type of insult has rendered results involving a beneficial role of endocannabinoid receptor agonists in the Central Nervous System. In this work, to further elucidate the mechanisms associated to this neuroprotective effect, focal brain ischemia was generated by middle cerebral artery occlusion (MCAo) in C57Bl/6 mice. Three, 24 and 48 h after MCAo, animals received CB1R agonist ACEA (1 mg/kg), CB1R antagonist AM251 (1 mg/kg) or vehicle. To assess motor activity, neural deficit scores and motor tests were performed 1 day before and 3, 7, 14, 21, and 28 days after MCAo. At 7 and 28 days post lesion, cytoskeleton structure, astroglial and microglial reaction, and alterations in synapsis were studied in the cerebral cortex. ACEA treatment reduced astrocytic reaction, neuronal death, and dendritic loss. In contrast, AM251 treatment increased these parameters. Motor tests showed a progressive deterioration in motor activity in ischemic animals, which only ACEA treatment was able to counteract. Our results suggest that CB1R may be involved in neuronal survival and in the regulation of neuroprotection during focal cerebral ischemia in mice. PMID:26296704

  10. Serotonin type 1D receptors (5HT1DR) are differentially distributed in nerve fibres innervating craniofacial tissues

    PubMed Central

    Harriott, AM; Gold, MS

    2009-01-01

    We tested the hypothesis that the 5HT1DR, the primary antinociceptive target of triptans, is differentially distributed in tissues responsible for migraine pain. The density of 5HT1DR was quantified in tissues obtained from adult female rats with Western blot analysis. Receptor location was assessed with immunohistochemistry. The density of 5HT1DR was significantly greater in tissues known to produce migraine-like pain (i.e. circle of Willis and dura) than in structures in which triptans have no antinociceptive efficacy (i.e. temporalis muscle). 5HT1DR-like immunoreactivity was restricted to neuronal fibres, where it colocalized with calcitonin gene-related peptide and tyrosine hydroxylase immunoreactive fibres. These results are consistent with our hypothesis that the limited therapeutic profile of triptans could reflect its differential peripheral distribution and that the antinociceptive efficacy reflects inhibition of neuropeptide release from sensory afferents. An additional site of action at sympathetic efferents is also suggested. PMID:18557979

  11. Alternate receptor usage of neuropilin-1 and glucose transporter protein 1 by the human T cell leukemia virus type 1

    SciTech Connect

    Jin Qingwen; Alkhatib, Bashar; Cornetta, Kenneth; Alkhatib, Ghalib

    2010-01-20

    Recent studies have demonstrated that neuropilin 1 (NP-1) is involved in HTLV-1 entry; however, the role NP-1 plays in this process is not understood. We demonstrated that ectopic expression of human NP-1 but not NP-2 cDNA increased susceptibility to HTLV-1. SiRNA-mediated inhibition of NP-1 expression correlated with significant reduction of HTLV-1 Env-mediated fusion. The vascular endothelial growth factor (VEGF{sub 165}) caused downmodulation of surface NP-1 and inhibited HTLV-1 infection of U87 cells. In contrast, VEGF{sub 165} partially inhibited infection of primary astrocytes and had no significant effect on infection of HeLa cells. VEGF{sub 165} and antibodies to the glucose transporter protein 1 (anti-GLUT-1) were both needed to block infection of primary astrocytes, however, only anti-GLUT-1 antibodies were sufficient to block infection of HeLa cells. HTLV-1 Env forms complexes with both NP-1 and GLUT-1 in primary human astrocytes. The alternate usage of these two cellular receptors may have important implications regarding HTLV-1 neuro-tropism.

  12. Nutrient induced type 2 and chemical induced type 1 experimental diabetes differently modulate gastric GLP-1 receptor expression.

    PubMed

    Bloch, Olga; Broide, Efrat; Ben-Yehudah, Gilad; Cantrell, Dror; Shirin, Haim; Rapoport, Micha J

    2015-01-01

    T2DM patients demonstrate reduced GLP-1 receptor (GLP-1R) expression in their gastric glands. Whether induced T2DM and T1DM differently affect the gastric GLP-1R expression is not known. This study assessed extrapancreatic GLP-1R system in glandular stomach of rodents with different types of experimental diabetes. T2DM and T1DM were induced in Psammomys obesus (PO) by high-energy (HE) diet and by streptozotocin (STZ) in Sprague Dawly (SD) rats, respectively. GLP-1R expression was determined in glandular stomach by RT PCR and immunohistomorphological analysis. The mRNA expression and cellular association of the GLP-1R in principal glands were similar in control PO and SD rats. However, nutrient and chemical induced diabetes resulted in opposite alterations of glandular GLP-1R expression. Diabetic PO demonstrated increased GLP-1R mRNA expression, intensity of cellular GLP-1R immunostaining, and frequency of GLP-1R positive cells in the neck area of principal glands compared with controls. In contrast, SD diabetic rats demonstrated decreased GLP-1 mRNA, cellular GLP-1R immunoreactivity, and frequency of GLP-1R immunoreactive cells in the neck area compared with controls. In conclusion, nutrient and chemical induced experimental diabetes result in distinct opposite alterations of GLP-1R expression in glandular stomach. These results suggest that induced T1DM and T2DM may differently modulate GLP-1R system in enteropancreatic axis. PMID:25893200

  13. Angiotensin II-induced angiotensin II type I receptor lysosomal degradation studied by fluorescence lifetime imaging microscopy

    NASA Astrophysics Data System (ADS)

    Li, Hewang; Yu, Peiying; Felder, Robin A.; Periasamy, Ammasi; Jose, Pedro A.

    2009-02-01

    Upon activation, the angiotensin (Ang) II type 1 receptor (AT1Rs) rapidly undergoes endocytosis. After a series of intracellular processes, the internalized AT1Rs recycle back to the plasma membrane or are trafficked to proteasomes or lysosomes for degradation. We recently reported that AT1Rs degrades in proteasomes upon stimulation of the D5 dopamine receptor (D5R) in human renal proximal tubule and HEK-293 cells. This is in contrast to the degradation of AT1R in lysosomes upon binding Ang II. However, the dynamic regulation of the AT1Rs in lysosomes is not well understood. Here we investigated the AT1Rs lysosomal degradation using FRET-FLIM in HEK 293 cells heterologously expressing the human AT1R tagged with EGFP as the donor fluorophore. Compared to its basal state, the lifetime of AT1Rs decreased after a 5-minute treatment with Ang II treatment and colocalized with Rab5 but not Rab7 and LAMP1. With longer Ang II treatment (30 min), the AT1Rs lifetime decreased and co-localized with Rab5, as well as Rab7 and LAMP1. The FLIM data are corroborated with morphological and biochemical co-immunoprecipitation studies. These data demonstrate that Ang II induces the internalization of AT1Rs into early sorting endosomes prior to trafficking to late endosomes and subsequent degradation in lysosomes.

  14. Angiotensin type 1a receptor-deficient mice develop diabetes-induced cardiac dysfunction, which is prevented by renin-angiotensin system inhibitors

    PubMed Central

    2013-01-01

    Background Diabetes-induced organ damage is significantly associated with the activation of the renin-angiotensin system (RAS). Recently, several studies have demonstrated a change in the RAS from an extracellular to an intracellular system, in several cell types, in response to high ambient glucose levels. In cardiac myocytes, intracellular angiotensin (ANG) II synthesis and actions are ACE and AT1 independent, respectively. However, a role of this system in diabetes-induced organ damage is not clear. Methods To determine a role of the intracellular ANG II in diabetic cardiomyopathy, we induced diabetes using streptozotocin in AT1a receptor deficient (AT1a-KO) mice to exclude any effects of extracellular ANG II. Further, diabetic animals were treated with a renin inhibitor aliskiren, an ACE inhibitor benazeprilat, and an AT1 receptor blocker valsartan. Results AT1a-KO mice developed significant diastolic and systolic dysfunction following 10 wks of diabetes, as determined by echocardiography. All three drugs prevented the development of cardiac dysfunction in these animals, without affecting blood pressure or glucose levels. A significant down regulation of components of the kallikrein-kinin system (KKS) was observed in diabetic animals, which was largely prevented by benazeprilat and valsartan, while aliskiren normalized kininogen expression. Conclusions These data indicated that the AT1a receptor, thus extracellular ANG II, are not required for the development of diabetic cardiomyopathy. The KKS might contribute to the beneficial effects of benazeprilat and valsartan in diabetic cardiomyopathy. A role of intracellular ANG II is suggested by the inhibitory effects of aliskiren, which needs confirmation in future studies. PMID:24215514

  15. Regulation of corticotropin-releasing factor and its types 1 and 2 receptors by leptin in rats subjected to treadmill running-induced stress.

    PubMed

    Huang, Qingling; Timofeeva, Elena; Richard, Denis

    2006-10-01

    The present study was conducted to investigate the long-term effects of subchronic elevation of central leptin levels on the expression of corticotropin-releasing factor (CRF) and its types 1 and 2 receptors in the brain of rats subjected to treadmill running-induced stress. PBS or recombinant murine leptin was infused continuously for a period of 5 days into the third ventricle of rats with the aid of osmotic minipumps at a delivery rate of 2 mug/day. On the fifth day of infusion, rats were killed under resting conditions or after a session of treadmill running, which is known to induce a stress response in rats. Leptin treatment significantly decreased food intake, body weight, white adipose tissue weight, glucose and insulin plasma contents, and blunted the treadmill running-induced elevation in plasma levels of corticosterone. Leptin infusion prevented stress-induced de novo synthesis of CRF in the paraventricular hypothalamic nucleus (PVN), which was measured using the intronic probe for CRF heteronuclear RNA. The induction of the type 1 CRF receptor (CRF(1)R) in the PVN and supraoptic nucleus in running rats was also significantly blunted by leptin. In contrast, leptin treatment strongly increased the expression of type 2 CRF receptor (CRF(2)R) in the ventromedial hypothalamic nucleus (VMH). The present results suggest that subchronic elevation of central levels of leptin blunts treadmill running-induced activation of the hypothalamic-pituitary-adrenal axis through the inhibition of activation of the CRFergic PVN neurons, and potentially enhances the anorectic CRF effects via the stimulation of expression of CRF(2)R in the VMH. PMID:17065401

  16. The bovine papillomavirus type 1 E5 transforming protein specifically binds and activates the beta-type receptor for the platelet-derived growth factor but not other related tyrosine kinase-containing receptors to induce cellular transformation.

    PubMed Central

    Goldstein, D J; Li, W; Wang, L M; Heidaran, M A; Aaronson, S; Shinn, R; Schlegel, R; Pierce, J H

    1994-01-01

    The 44-amino-acid E5 protein of bovine papillomavirus type 1 is a highly hydrophobic protein which appears to transform cells through the activation of growth factor receptors. To investigate the specificity of E5-growth factor receptor interactions required for mitogenic signaling, we utilized a nontumorigenic, murine myeloid cell line (32D) which is strictly dependent on interleukin-3 (IL-3) for sustained proliferation in culture. This IL-3 dependence can be functionally substituted by the expression of a variety of surrogate growth factor receptors and the addition of the corresponding ligand. Several receptor cDNAs for the alpha- and beta-type platelet-derived growth factor receptors [alpha PDGFR and beta PDGFR], the epidermal growth factor receptor, and the colony-stimulating factor 1 receptor) were transfected into 32D cells constitutively expressing the E5 protein to test for IL-3-independent growth. Only beta PDGFR was capable of abrogating the IL-3 dependence of 32D cells. The proliferative signal induced by the coexpression of beta PDGFR and E5 was accompanied by stable complex formation between these proteins, constitutive tyrosine phosphorylation of the receptor, and tumorigenicity in nude mice. The lack of cooperative interaction between E5 and the epidermal growth factor receptor, the colony-stimulating factor 1 receptor, and the highly related alpha PDGFR was paralleled by the inability of E5 to bind to these receptors and failure to increase receptor tyrosine phosphorylation. Thus, these data indicate that the ability of E5 to induce sustained proliferation and transformation of 32D cells is a direct consequence of specific interaction between the E5 protein and the beta PDGFR signaling complex and the subsequent stimulation of receptor tyrosine phosphorylation. Images PMID:8207816

  17. Suppression of Neurotensin Receptor Type 1 Expression and Function by Histone Deacetylase Inhibitors in Human Colorectal Cancers*

    PubMed Central

    Wang, Xiaofu; Jackson, Lindsey N.; Johnson, Sara M.; Wang, Qingding; Evers, B. Mark

    2010-01-01

    Neurotensin (NT), a gut peptide, stimulates growth of colorectal cancers (CRCs) which possess the high affinity NT receptor (NTR1). Sodium butyrate (NaBT) is a potent histone deacetylase inhibitor (HDACi) which induces growth arrest, differentiation and apoptosis of CRCs. Previously, we showed that NaBT increases nuclear GSK-3β expression and kinase activity; GSK-3β functions as a negative regulator of ERK signaling. The purpose of our current study was to determine: (a) whether HDACi alters NTR1 expression and function, and (b) the role of GSK-3β/ERK in NTR1 regulation. Human CRCs with NTR1 were treated with various HDACi and NTR1 expression and function were assessed. Treatment with HDACi dramatically decreased endogenous NTR1 mRNA, protein and promoter activity. Overexpression of GSK-3β decreased NTR1 promoter activity (> 30%); inhibition of GSK-3β increased NTR1 expression in CRC cells, indicating that GSK-3β is a negative regulator of ERK and NTR1. Consistent with our previous findings, HDACi significantly decreased phosphorylated ERK while increasing GSK-3β. Selective MEK/ERK inhibitors suppressed NTR1 mRNA expression in a time- and dose-dependent fashion, and reduced NTR1 promoter activity by ~70%. Finally, pretreatment with NaBT prevented NT-mediated COX-2 and c-myc expression and attenuated NT-induced IL-8 expression. HDACi suppresses endogenous NTR1 expression and function in CRC cell lines; this effect is mediated through, at least in part, the GSK-3β/ERK pathway. The down-regulation of NTR1 in CRCs may represent an important mechanism for the anti-cancer effects of HDACi. PMID:20663927

  18. Leishmania major-human macrophage interactions: cooperation between Mac-1 (CD11b/CD18) and complement receptor type 1 (CD35) in promastigote adhesion.

    PubMed Central

    Rosenthal, L A; Sutterwala, F S; Kehrli, M E; Mosser, D M

    1996-01-01

    It has been suggested that the developmental maturation of Leishmania major promastigotes can affect their interaction with human complement receptors. To study this, we measured the adhesion of metacyclic and logarithmic-phase L. major promastigotes to complement receptors expressed on primary macrophages, to recombinant receptors expressed on transfected cells, or to purified complement receptors in a cell-free system. We demonstrate that complement-opsonized promastigotes can bind to both Mac-1 and complement receptor type 1 (CR1) and that the transition of promastigotes from the noninfectious logarithmic phase of growth to the infectious metacyclic stage does not affect this interaction. Furthermore, we show that Mac-1 and CR1 can cooperate to mediate the efficient adhesion of complement-opsonized metacyclic promastigotes to cells expressing both receptors. On human monocyte-derived macrophages, Mac-1 appears to make a quantitatively greater contribution to this adhesion than does CR1, since blocking macrophage Mac-1 diminishes metacyclic promastigote adhesion to a greater extent than does blocking CR1. In addition, bovine monocytes lacking Mac-1 exhibit a dramatic decrease in complement-dependent promastigote adhesion, relative to normal monocytes. The predominance of Mac-1 in these interactions is due, at least in part, to the factor I cofactor activity of CR1, which facilitates the conversion of C3b to iC3b. The stable adhesion of complement-opsonized metacyclic promastigotes to Mac-1 is a prerequisite for phagocytosis by human monocyte-derived macrophages. Blocking Mac-1 on macrophages abrogates the majority of the complement-dependent phagocytosis of promastigotes, whereas blocking CR1 has no detectable effect on phagocytosis. In addition, bovine monocytes lacking Mac-1 exhibit a dramatic reduction in promastigote phagocytosis relative to normal bovine monocytes. We conclude, therefore, that the two complement receptors, Mac-1 and CR1, can cooperate to

  19. Oxidative DNA Damage in Kidneys and Heart of Hypertensive Mice Is Prevented by Blocking Angiotensin II and Aldosterone Receptors

    PubMed Central

    Brand, Susanne; Amann, Kerstin; Mandel, Philipp; Zimnol, Anna; Schupp, Nicole

    2014-01-01

    Introduction Recently, we could show that angiotensin II, the reactive peptide of the blood pressure-regulating renin-angiotensin-aldosterone-system, causes the formation of reactive oxygen species and DNA damage in kidneys and hearts of hypertensive mice. To further investigate on the one hand the mechanism of DNA damage caused by angiotensin II, and on the other hand possible intervention strategies against end-organ damage, the effects of substances interfering with the renin-angiotensin-aldosterone-system on angiotensin II-induced genomic damage were studied. Methods In C57BL/6-mice, hypertension was induced by infusion of 600 ng/kg • min angiotensin II. The animals were additionally treated with the angiotensin II type 1 receptor blocker candesartan, the mineralocorticoid receptor blocker eplerenone and the antioxidant tempol. DNA damage and the activation of transcription factors were studied by immunohistochemistry and protein expression analysis. Results Administration of angiotensin II led to a significant increase of blood pressure, decreased only by candesartan. In kidneys and hearts of angiotensin II-treated animals, significant oxidative stress could be detected (1.5-fold over control). The redox-sensitive transcription factors Nrf2 and NF-κB were activated in the kidney by angiotensin II-treatment (4- and 3-fold over control, respectively) and reduced by all interventions. In kidneys and hearts an increase of DNA damage (3- and 2-fold over control, respectively) and of DNA repair (3-fold over control) was found. These effects were ameliorated by all interventions in both organs. Consistently, candesartan and tempol were more effective than eplerenone. Conclusion Angiotensin II-induced DNA damage is caused by angiotensin II type 1 receptor-mediated formation of oxidative stress in vivo. The angiotensin II-mediated physiological increase of aldosterone adds to the DNA-damaging effects. Blocking angiotensin II and mineralocorticoid receptors therefore

  20. Quantitative autoradiography of angiotensin II receptors in the SHR brain

    SciTech Connect

    Gehlert, D.R.; Speth, R.C.; Wamsley, J.K.

    1986-11-01

    Several lines of evidence indicate brain angiotensin II is associated with the elevation of blood pressure seen in the spontaneously hypertensive rat (SHR). These include an increased pressor response to intracerebroventricularly administered angiotensin II and a reduction of blood pressure in response to centrally administered angiotensin II receptor antagonists. Using quantitative receptor autoradiography, we have detected greater angiotensin II receptor binding in a number of discrete brain nuclei of the 6-week-old SHR when compared to age-matched Wistar-Kyoto controls. Tissue sections from various brain regions were labeled with (/sup 125/I)-angiotensin II according to a previously described method. Autoradiograms were generated by apposing the labeled tissue sections to LKB Ultrofilm along with brain paste standards which contained known amounts of (/sup 125/I). Quantitation of the binding, utilizing computer-assisted microdensitometry, indicated greater (/sup 125/I)-angiotensin II binding in several brain areas implicated in cardiovascular control including the subfornical organ, nucleus of the solitary tract, dorsal motor nucleus of the vagus, locus coeruleus, supraoptic nucleus and the organum vasculosum of the lamina terminalis. Scatchard analysis of the binding in the nucleus of the solitary tract indicated an increased receptor number (Bmax) was responsible for the change while binding in two forebrain structures, the subfornical organ and supraoptic nucleus, showed alterations in receptor number and affinity (Kd). Several other brain regions, unrelated to cardiovascular control, exhibited no change in (/sup 125/I)-angiotensin II binding.

  1. Association between the p170 form of human topoisomerase II and progeny viral DNA in cells infected with herpes simplex virus type 1.

    PubMed Central

    Ebert, S N; Subramanian, D; Shtrom, S S; Chung, I K; Parris, D S; Muller, M T

    1994-01-01

    Endogenous host topoisomerase II acts upon herpes simplex virus type 1 (HSV-1) DNA in infected cells (S.N. Ebert, S.S. Shtrom, and M.T. Muller, J. Virol. 56:4059-4066, 1990), and cleavage is directed exclusively at progeny viral DNA while parental DNA is resistant. To evaluate the possibility that HSV-1 induces topoisomerase II activity which could account for the preferential cleavage of progeny viral DNA, we assessed topoisomerase II cleavage activity on cellular and viral DNA substrates before and after the initiation of viral DNA replication. We show that cleavage of a host gene in mock-infected cells was similar to that observed in HSV-1-infected cells, regardless of whether viral DNA replication had occurred. In addition, quantitative measurements revealed comparable amounts of topoisomerase II activity in infected and mock-infected cells; thus, HSV-1 neither induces nor encodes its own type II topoisomerase and cleavages in vivo are due to a preexisting host topoisomerase. Human cells contain two isozymes of topoisomerase II (p170 and p180), encoded by separate genes. Through the use of isozyme-specific antibodies, we demonstrate that only p170 was found to be cross-linked to HSV-1 DNA even though both forms were present at nearly constant levels in HSV-1-infected cells. Immunofluorescence revealed that by 6 h postinfection, p170 becomes redistributed and localized to sites of active viral DNA synthesis. The data suggest that p170 gains preferential access to replicated viral DNA molecules, which explains why topoisomerase II activity is concentrated on progeny DNA. Images PMID:8289331

  2. Heavily reddened z ˜ 2 Type 1 quasars - II. H α star formation constraints from SINFONI IFU observations

    NASA Astrophysics Data System (ADS)

    Alaghband-Zadeh, S.; Banerji, Manda; Hewett, Paul C.; McMahon, Richard G.

    2016-06-01

    We use near-infrared integral field unit spectroscopy to search for H α emission associated with star formation in a sample of 28 heavily reddened (E(B - V) ≃ 0.5-1.9), hyperluminous (log({{L}}_{bol}/erg s^{-1})≃ 47-48) broad-line quasars at z ≃ 1.4-2.7. 16 of the 28 quasars show evidence for star formation with an average extinction-corrected star formation rate (SFR) of 320 ± 70 M⊙ yr-1. A stacked spectrum of the detections shows weak [N II], consistent with star formation as the origin of the narrow H α emission. The star-forming regions are spatially unresolved in 11 of the 16 detections and constrained to lie within ˜6 kpc of the quasar emission. In the five resolved detections we find the star-forming regions are extended on scales of ˜8 kpc around the quasar emission. The prevalence of high SFRs is consistent with the identification of the heavily reddened quasar population as representing a transitional phase from apparent `starburst galaxies' to optically luminous quasars. Upper limits are determined for 10 quasars in which star formation is undetected. In two of the quasars the SFR is constrained to be relatively modest, <50 M⊙ yr-1, but significantly higher levels of star formation could be present in the other eight quasars. The combination of the 16 strong star formation detections and the eight high SFR limits means that high levels of star formation may be present in the majority of the sample. Higher spatial resolution data, of multiple emission lines, will allow us to better understand the interplay between star formation and active galactic nucleus activity in these transitioning quasars.

  3. NADPH Oxidases and Angiotensin II Receptor Signaling

    PubMed Central

    Garrido, Abel Martin; Griendling, Kathy K.

    2010-01-01

    Over the last decade many studies have demonstrated the importance of reactive oxygen species (ROS) production by NADPH oxidases in angiotensin II (Ang II) signaling, as well as a role for ROS in the development of different diseases in which Ang II is a central component. In this review, we summarize the mechanism of activation of NADPH oxidases by Ang II and describe the molecular targets of ROS in Ang II signaling in the vasculature, kidney and brain. We also discuss the effects of genetic manipulation of NADPH oxidase function on the physiology and pathophysiology of the renin angiotensin system. PMID:19059306

  4. The Angiotensin II Type 2 (AT2) Receptor Promotes Axonal Regeneration in the Optic Nerve of Adult Rats

    PubMed Central

    Lucius, Ralph; Gallinat, Stefan; Rosenstiel, Philip; Herdegen, Thomas; Sievers, Jobst; Unger, Thomas

    1998-01-01

    The renin-angiotensin system (RAS) has been traditionally linked to blood pressure and volume regulation mediated through the angiotensin II (ANG II) type 1 (AT1) receptor. Here we report that ANG II via its ANG II type 2 (AT2) receptor promotes the axonal elongation of postnatal rat retinal explants (postnatal day 11) and dorsal root ganglia neurons in vitro, and, moreover, axonal regeneration of retinal ganglion cells after optic nerve crush in vivo. In retinal explants, ANG II (10−7–10−5 M) induced neurite elongation via its AT2 receptor, since the effects were mimicked by the AT2 receptor agonist CGP 42112 (10−5 M) and were entirely abolished by costimulation with the AT2 receptor antagonist PD 123177 (10−5 M), but not by the AT1 receptor antagonist losartan (10−5 M). To investigate whether ANG II is able to promote axonal regeneration in vivo, we performed optic nerve crush experiments in the adult rats. After ANG II treatment (0.6 nmol), an increased number of growth-associated protein (GAP)-43–positive fibers was detected and the regenerating fibers regularly crossed the lesion site (1.6 mm). Cotreatment with the AT2 receptor antagonist PD 123177 (6 nmol), but not with the AT1 receptor antagonist losartan (6 nmol), completely abolished the ANG II–induced axonal regeneration, providing for the first time direct evidence for receptor-specific neurotrophic action of ANG II in the central nervous system of adult mammals and revealing a hitherto unknown function of the RAS. PMID:9705948

  5. Corticotropin-Releasing Hormone Receptor Type 1 (CRHR1) Clustering with MAGUKs Is Mediated via Its C-Terminal PDZ Binding Motif

    PubMed Central

    Bender, Julia; Engeholm, Maik; Ederer, Marion S.; Breu, Johannes; Møller, Thor C.; Michalakis, Stylianos; Rasko, Tamas; Wanker, Erich E.; Biel, Martin; Martinez, Karen L.; Wurst, Wolfgang; Deussing, Jan M.

    2015-01-01

    The corticotropin-releasing hormone receptor type 1 (CRHR1) plays an important role in orchestrating neuroendocrine, behavioral, and autonomic responses to stress. To identify molecules capable of directly modulating CRHR1 signaling, we performed a yeast-two-hybrid screen using the C-terminal intracellular tail of the receptor as bait. We identified several members of the membrane-associated guanylate kinase (MAGUK) family: postsynaptic density protein 95 (PSD95), synapse-associated protein 97 (SAP97), SAP102 and membrane associated guanylate kinase, WW and PDZ domain containing 2 (MAGI2). CRHR1 is co-expressed with the identified MAGUKs and with the additionally investigated PSD93 in neurons of the adult mouse brain and in primary hippocampal neurons, supporting the probability of a physiological interaction in vivo. The C-terminal PDZ (PSD-95, discs large, zona occludens 1) binding motif of CRHR1 is essential for its physical interaction with MAGUKs, as revealed by the CRHR1-STAVA mutant, which harbors a functionally impaired PDZ binding motif. The imitation of a phosphorylation at Thr413 within the PDZ binding motif also disrupted the interaction with MAGUKs. In contrast, distinct PDZ domains within the identified MAGUKs are involved in the interactions. Expression of CRHR1 in primary neurons demonstrated its localization throughout the neuronal plasma membrane, including the excitatory post synapse, where the receptor co-localized with PSD95 and SAP97. The co-expression of CRHR1 and respective interacting MAGUKs in HEK293 cells resulted in a clustered subcellular co-localization which required an intact PDZ binding motif. In conclusion, our study characterized the PDZ binding motif-mediated interaction of CRHR1 with multiple MAGUKs, which directly affects receptor function. PMID:26352593

  6. Angiotensin II Receptor Blockers and Cancer Risk

    PubMed Central

    Zhao, Yun-Tao; Li, Peng-Yang; Zhang, Jian-Qiang; Wang, Lei; Yi, Zhong

    2016-01-01

    Abstract Angiotensin II receptor blockers (ARB) are widely used drugs that are proven to reduce cardiovascular disease events; however, several recent meta-analyses yielded conflicting conclusions regarding the relationship between ARB and cancer incidence, especially when ARB are combined with angiotensin-converting enzyme inhibitors (ACEI). We investigated the risk of cancer associated with ARB at different background ACEI levels. Search of PubMed and EMBASE (1966 to December 17, 2015) without language restriction. Randomized, controlled trials (RCTs) had at least 12 months of follow-up data and reported cancer incidence was included. Study characteristics, quality, and risk of bias were assessed by 2 reviewers independently. Nineteen RCTs including 148,334 patients were included in this study. Random-effects model meta-analyses were used to estimate the risk ratio (RR) of cancer risk. No excessive cancer risk was observed in our analyses of ARB alone versus placebo alone without background ACEI use (risk ratio [RR] 1.08, 95% confidence interval [CI] 1.00–1.18, P = 0.05); ARB alone versus ACEI alone (RR 1.03, 95%CI 0.94–1.14, P = 0.50); ARB plus partial use of ACEI versus placebo plus partial use of ACEI (RR 0.97, 95%CI 0.90–1.04, P = 0.33); and ARB plus ACEI versus ACEI (RR 0.99, 95%CI 0.79–1.24, P = 0.95). Lack of long-term data, inadequate reporting of safety data, significant heterogeneity in underlying study populations, and treatment regimens. ARB have a neutral effect on cancer incidence in randomized trials. We observed no significant differences in cancer incidence when we compared ARB alone with placebo alone, ARB alone with ACEI alone, ARB plus partial use of ACEI with placebo plus partial use of ACEI, or ARB plus ACEI combination with ACEI. PMID:27149494

  7. The Calcitonin Receptor Gene Is a Candidate for Regulation of Susceptibility to Herpes simplex Type 1 Neuronal Infection Leading to Encephalitis in Rat

    PubMed Central

    Abdelmagid, Nada; Bereczky-Veress, Biborka; Guerreiro-Cacais, André Ortlieb; Bergman, Petra; Luhr, Katarina M.; Bergström, Tomas; Sköldenberg, Birgit; Piehl, Fredrik

    2012-01-01

    Herpes simplex encephalitis (HSE) is a fatal infection of the central nervous system (CNS) predominantly caused by Herpes simplex virus type 1. Factors regulating the susceptibility to HSE are still largely unknown. To identify host gene(s) regulating HSE susceptibility we performed a genome-wide linkage scan in an intercross between the susceptible DA and the resistant PVG rat. We found one major quantitative trait locus (QTL), Hse1, on rat chromosome 4 (confidence interval 24.3–31 Mb; LOD score 29.5) governing disease susceptibility. Fine mapping of Hse1 using recombinants, haplotype mapping and sequencing, as well as expression analysis of all genes in the interval identified the calcitonin receptor gene (Calcr) as the main candidate, which also is supported by functional studies. Thus, using unbiased genetic approach variability in Calcr was identified as potentially critical for infection and viral spread to the CNS and subsequent HSE development. PMID:22761571

  8. Role of Mas receptor antagonist (A779) in renal hemodynamics in condition of blocked angiotensin II receptors in rats.

    PubMed

    Mansoori, A; Oryan, S; Nematbakhsh, M

    2016-03-01

    The vasodilatory effect of angiotensin 1-7 (Ang 1-7) is exerted in the vascular bed via Mas receptor (MasR) gender dependently. However, the crosstalk between MasR and angiotensin II (Ang II) types 1 and 2 receptors (AT1R and AT2R) may change some actions of Ang 1-7 in renal circulation. In this study by blocking AT1R and AT2R, the role of MasR in kidney hemodynamics was described. In anaesthetized male and female Wistar rats, the effects of saline as vehicle and MasR blockade (A779) were tested on mean arterial pressure (MAP), renal perfusion pressure (RPP), renal blood flow (RBF), and renal vascular resistance (RVR) when both AT1R and AT2R were blocked by losartan and PD123319, respectively. In male rats, when AT1R and AT2R were blocked, there was a tendency for the increase in RBF/wet kidney tissue weight (RBF/KW) to be elevated by A779 as compared with the vehicle (P=0.08), and this was not the case in female rats. The impact of MasR on renal hemodynamics appears not to be sexual dimorphism either when Ang II receptors were blocked. It seems that co-blockade of all AT1R, AT2R, and MasR may alter RBF/ KW in male more than in female rats. These findings support a crosstalk between MasR and Ang II receptors in renal circulation. PMID:27030624

  9. Quantitation of HLA Class II Protein Incorporated into Human Immunodeficiency Type 1 Virions Purified by Anti-CD45 Immunoaffinity Depletion of Microvesicles

    PubMed Central

    Trubey, Charles M.; Chertova, Elena; Coren, Lori V.; Hilburn, Joanne M.; Hixson, Catherine V.; Nagashima, Kunio; Lifson, Jeffrey D.; Ott, David E.

    2003-01-01

    Among the many host cell-derived proteins found in human immunodeficiency virus type 1 (HIV-1), HLA class II (HLA-II) appears to be selectively incorporated onto virions and may contribute to mechanisms of indirect imunopathogenesis in HIV infection and AIDS. However, the amount of HLA-II on the surface of HIV-1 particles has not been reliably determined due to contamination of virus preparations by microvesicles containing host cell proteins, including HLA-II. Even rigorous sucrose density centrifugation is unable to completely separate HIV-1 from microvesicles. CD45, a leukocyte integral membrane protein, is found on microvesicles, yet appears to be excluded from HIV-1 particles. Exploiting this observation, we have developed a CD45-based immunoaffinity depletion method for removing CD45-containing microvesicles that yields highly purified preparations of virions. Examination of CD45-depleted HIV-1MN by high-pressure liquid chromatography, protein sequencing, and amino acid analyses determined a molar ratio of HLA-II to Gag of 0.04 to 0.05 in the purified virions, corresponding to an estimated average of 50 to 63 native HLA-II complexes (i.e., a dimer of α and β heterodimers) per virion. These values are approximately 5- to 10-fold lower than those previously determined for other virion preparations that contained microvesicles. Our observations demonstrate the utility of CD45 immunoaffinity-based approaches for producing highly purified retrovirus preparations for applications that would benefit from the use of virus that is essentially free of microvesicles. PMID:14610192

  10. Development of a Highly Selective Allosteric Antagonist Radioligand for the Type 1 Cholecystokinin Receptor and Elucidation of Its Molecular Basis of Binding

    PubMed Central

    Dong, Maoqing; Vattelana, Ashton M.; Lam, Polo C.-H.; Orry, Andrew J.; Abagyan, Ruben; Christopoulos, Arthur; Sexton, Patrick M.; Haines, David R.

    2015-01-01

    Understanding the molecular basis of ligand binding to receptors provides insights useful for rational drug design. This work describes development of a new antagonist radioligand of the type 1 cholecystokinin receptor (CCK1R), (2-fluorophenyl)-2,3-dihydro-3-[(3-isoquinolinylcarbonyl)amino]-6-methoxy-2-oxo-l-H-indole-3-propanoate (T-0632), and exploration of the molecular basis of its binding. This radioligand bound specifically with high affinity within an allosteric pocket of CCK1R. T-0632 fully inhibited binding and action of CCK at this receptor, while exhibiting no saturable binding to the closely related type 2 cholecystokinin receptor (CCK2R). Chimeric CCK1R/CCK2R constructs were used to explore the molecular basis of T-0632 binding. Exchanging exonic regions revealed the functional importance of CCK1R exon 3, extending from the bottom of transmembrane segment (TM) 3 to the top of TM5, including portions of the intramembranous pocket as well as the second extracellular loop region (ECL2). However, CCK1R mutants in which each residue facing the pocket was changed to that present in CCK2R had no negative impact on T-0632 binding. Extending the chimeric approach to ECL2 established the importance of its C-terminal region, and site-directed mutagenesis of each nonconserved residue in this region revealed the importance of Ser208 at the top of TM5. A molecular model of T-0632-occupied CCK1R was consistent with these experimental determinants, also identifying Met121 in TM3 and Arg336 in TM6 as important. Although these residues are conserved in CCK2R, mutating them had a distinct impact on the two closely related receptors, suggesting differential orientation. This establishes the molecular basis of binding of a highly selective nonpeptidyl allosteric antagonist of CCK1R, illustrating differences in docking that extend beyond determinants attributable to distinct residues lining the intramembranous pocket in the two receptor subtypes. PMID:25319540

  11. Development of a highly selective allosteric antagonist radioligand for the type 1 cholecystokinin receptor and elucidation of its molecular basis of binding.

    PubMed

    Dong, Maoqing; Vattelana, Ashton M; Lam, Polo C-H; Orry, Andrew J; Abagyan, Ruben; Christopoulos, Arthur; Sexton, Patrick M; Haines, David R; Miller, Laurence J

    2015-01-01

    Understanding the molecular basis of ligand binding to receptors provides insights useful for rational drug design. This work describes development of a new antagonist radioligand of the type 1 cholecystokinin receptor (CCK1R), (2-fluorophenyl)-2,3-dihydro-3-[(3-isoquinolinylcarbonyl)amino]-6-methoxy-2-oxo-l-H-indole-3-propanoate (T-0632), and exploration of the molecular basis of its binding. This radioligand bound specifically with high affinity within an allosteric pocket of CCK1R. T-0632 fully inhibited binding and action of CCK at this receptor, while exhibiting no saturable binding to the closely related type 2 cholecystokinin receptor (CCK2R). Chimeric CCK1R/CCK2R constructs were used to explore the molecular basis of T-0632 binding. Exchanging exonic regions revealed the functional importance of CCK1R exon 3, extending from the bottom of transmembrane segment (TM) 3 to the top of TM5, including portions of the intramembranous pocket as well as the second extracellular loop region (ECL2). However, CCK1R mutants in which each residue facing the pocket was changed to that present in CCK2R had no negative impact on T-0632 binding. Extending the chimeric approach to ECL2 established the importance of its C-terminal region, and site-directed mutagenesis of each nonconserved residue in this region revealed the importance of Ser(208) at the top of TM5. A molecular model of T-0632-occupied CCK1R was consistent with these experimental determinants, also identifying Met(121) in TM3 and Arg(336) in TM6 as important. Although these residues are conserved in CCK2R, mutating them had a distinct impact on the two closely related receptors, suggesting differential orientation. This establishes the molecular basis of binding of a highly selective nonpeptidyl allosteric antagonist of CCK1R, illustrating differences in docking that extend beyond determinants attributable to distinct residues lining the intramembranous pocket in the two receptor subtypes. PMID:25319540

  12. Signaling complex formation of phospholipase Cbeta4 with metabotropic glutamate receptor type 1alpha and 1,4,5-trisphosphate receptor at the perisynapse and endoplasmic reticulum in the mouse brain.

    PubMed

    Nakamura, Michiko; Sato, Kazunori; Fukaya, Masahiro; Araishi, Kenji; Aiba, Atsu; Kano, Masanobu; Watanabe, Masahiko

    2004-12-01

    Upon activation of cell surface receptors coupled to the Gq subclass of G proteins, phospholipase C (PLC) beta hydrolyses membrane phospholipid to yield a pair of second messengers, inositol 1,4,5-trisphosphate (IP3) and 1,2-diacylglycerol. PLCbeta4 has been characterized as the isoform enriched in cerebellar Purkinje cells (PCs) and the retina and involved in motor and visual functions. Here we examined cellular and subcellular distributions of PLCbeta4 in adult mouse brains. Immunohistochemistry showed that high levels of PLCbeta4 were detected in the somatodendritic domain of neuronal populations expressing the metabotropic glutamate receptor (mGluR) type 1alpha, including olfactory periglomerular cells, neurons in the bed nucleus anterior commissure, thalamus, substantia nigra, inferior olive, and unipolar brush cells and PCs in the cerebellum. Low to moderate levels were detected in many other mGluR1alpha-positive neurons and in a few mGluR1alpha-negative neurons. In PCs, immunogold electron microscopy localized PLCbeta4 to the perisynapse, at which mGluR1alpha is concentrated, and to the smooth endoplasmic reticulum in dendrites and spines, an intracellular Ca2+ store gated by IP3 receptors. In the cerebellum, immunoblot demonstrated its concentrated distribution in the post-synaptic density and microsomal fractions, where mGluR1alpha and type 1 IP3 receptor were also greatly enriched. Furthermore, PLCbeta4 formed coimmunoprecipitable complexes with mGluR1alpha, type 1 IP3 receptor and Homer 1. These results suggest that PLCbeta4 is preferentially localized in the perisynapse and smooth endoplasmic reticulum as a component of the physically linked phosphoinositide signaling complex. This close molecular relationship might provide PLCbeta4 with a high-fidelity effector function to mediate various neuronal responses under physiological and pathophysiological conditions. PMID:15579147

  13. Augmented cocaine seeking in response to stress or CRF delivered into the ventral tegmental area following long-access self-administration is mediated by CRF receptor type 1 but not CRF receptor type 2.

    PubMed

    Blacktop, Jordan M; Seubert, Chad; Baker, David A; Ferda, Nathan; Lee, Geng; Graf, Evan N; Mantsch, John R

    2011-08-01

    Stressful events are determinants of relapse in recovering cocaine addicts. Excessive cocaine use may increase susceptibility to stressor-induced relapse through alterations in brain corticotropin-releasing factor (CRF) regulation of neurocircuitry involved in drug seeking. We previously reported that the reinstatement of cocaine seeking by a stressor (footshock) is CRF dependent and is augmented in rats that self-administered cocaine under long-access (LgA; 6 h daily) conditions for 14 d when compared with rats provided shorter daily cocaine access [short access (ShA) rats; 2 h daily]. Further, we have demonstrated that reinstatement in response to intracerebroventricular CRF administration is heightened in LgA rats. This study examined the role of altered ventral tegmental area (VTA) responsiveness to CRF in intake-dependent increases in CRF- and stress-induced cocaine seeking. Bilateral intra-VTA administration of CRF (250 or 500 ng/side) produced reinstatement in LgA but not ShA rats. In LgA rats, intra-VTA CRF-induced reinstatement was blocked by administration of the CRF-receptor type 1 (CRF-R1) antagonist antalarmin (500 ng/side) or CP-376395 (500 ng/side), but not the CRF-R2 antagonist astressin-2B (500 ng or 1 μg/side) or antisauvagine-30 (ASV-30; 500 ng/side) into the VTA. Likewise, intra-VTA antalarmin, but not astressin-2B, blocked footshock-induced reinstatement in LgA rats. By contrast, neither intra-VTA antalarmin nor CP-376395 altered food-reinforced lever pressing. Intra-VTA injection of the CRF-R1-selective agonist cortagine (100 ng/side) but not the CRF-R2-selective agonist rat urocortin II (rUCN II; 250 ng/side) produced reinstatement. These findings reveal that excessive cocaine use increases susceptibility to stressor-induced relapse in part by augmenting CRF-R1-dependent regulation of addiction-related neurocircuitry in the VTA. PMID:21813699

  14. Exclusion of the locus for autosomal recessive pseudohypoaldosteronism type 1 from the mineralocorticoid receptor gene region on human chromosome 4q by linkage analysis

    SciTech Connect

    Chung, E.; Hanukoglu, A.; Rees, M.; Thompson, R.; Gardiner, R.M.

    1995-10-01

    Pseudohypoaldosteronism type 1 (PHA1) is an uncommon inherited disorder characterized by salt-wasting in infancy arising from target organ unresponsiveness to mineralocorticoids. Clinical expression of the disease varies from severely affected infants who may die to apparently asymptomatic individuals. Inheritance is Mendelian and may be either autosomal dominant or autosomal recessive. A defect in the mineralocortiocoid receptor has been implicated as a likely cause of PHA1. The gene for human mineralocorticoid receptor (MLR) has been cloned and physically mapped to human chromosome 4q31.1-31.2. The etiological role of MLR in autosomal recessive PHA1 was investigated by performing linkage analysis between PHA1 and three simple sequence length polymorphisms (D4S192, D4S1548, and D4S413) on chromosome 4q in 10 consanguineous families. Linkage analysis was carried out assuming autosomal recessive inheritance with full penetrance and zero phenocopy rate using the MLINK program for two-point analysis and the HOMOZ program for multipoint analysis. Lod scores of less than -2 were obtained over the whole region from D4S192 to D4S413 encompassing MLR. This provides evidence against MLR as the site of mutations causing PHA1 in the majority of autosomal recessive families. 34 refs., 3 figs., 2 tabs.

  15. Placenta expressing the greatest quantity of bisphenol A receptor ERR{gamma} among the human reproductive tissues: Predominant expression of type-1 ERRgamma isoform.

    PubMed

    Takeda, Yukimasa; Liu, Xiaohui; Sumiyoshi, Miho; Matsushima, Ayami; Shimohigashi, Miki; Shimohigashi, Yasuyuki

    2009-07-01

    Estrogen-related receptor gamma (ERRgamma), one of the 48 human nuclear receptors, has a fully active conformation with no ligand. We recently demonstrated that ERRgamma binds strongly bisphenol A (BPA), one of the nastiest endocrine disruptors, and thus retaining ERRgamma's high basal constitutive activity. A report that BPA accumulates in the human maternal-fetal placental unit has led us to hypothesize that a large amount of ERRgamma might exist in the human placenta. Here we report evidence that placenta indeed expresses ERRgamma exceptionally strongly. We first ascertained the presence of nine different ERRgamma mRNA variants and the resulting three ERRgamma protein isoforms. By real-time PCR, we estimated the relative amount of ERRgamma mRNA using total RNA extracts from human reproductive tissues. Placenta was found to express ERRgamma extremely highly. Among the three ERRgamma protein isoforms, placenta exclusively expresses the type-1 isoform, which possesses additional 23-mer amino-acid residues at the N-terminus of the ordinary ERRgamma. This N-terminal elongation was found to elevate by approximately 50% the basal constitutive activity of ERRgamma, as evidenced in the luciferase reporter gene assay. The present results suggest that BPA accumulates in the placenta by binding to ERRgamma. PMID:19304792

  16. Control of Toll-like Receptor-mediated T Cell-independent Type 1 Antibody Responses by the Inducible Nuclear Protein IκB-ζ*

    PubMed Central

    Hanihara-Tatsuzawa, Fumito; Miura, Hanae; Kobayashi, Shuhei; Isagawa, Takayuki; Okuma, Atsushi; Manabe, Ichiro; MaruYama, Takashi

    2014-01-01

    Antibody responses have been classified as being either T cell-dependent or T cell-independent (TI). TI antibody responses are further classified as being either type 1 (TI-1) or type 2 (TI-2), depending on their requirement for B cell-mediated antigen receptor signaling. Although the mechanistic basis of antibody responses has been studied extensively, it remains unclear whether different antibody responses share similarities in their transcriptional regulation. Here, we show that mice deficient in IκB-ζ, specifically in their B cells, have impaired TI-1 antibody responses but normal T cell-dependent and TI-2 antibody responses. The absence of IκB-ζ in B cells also impaired proliferation triggered by Toll-like receptor (TLR) activation, plasma cell differentiation, and class switch recombination (CSR). Mechanistically, IκB-ζ-deficient B cells could not induce TLR-mediated induction of activation-induced cytidine deaminase (AID), a class-switch DNA recombinase. Retroviral transduction of AID in IκB-ζ-deficient B cells restored CSR activity. Furthermore, acetylation of histone H3 in the vicinity of the transcription start site of the gene that encodes AID was reduced in IκB-ζ-deficient B cells relative to IκB-ζ-expressing B cells. These results indicate that IκB-ζ regulates TLR-mediated CSR by inducing AID. Moreover, IκB-ζ defines differences in the transcriptional regulation of different antibody responses. PMID:25124037

  17. Corticotropin releasing factor type-1 receptor antagonism in the dorsolateral bed nucleus of the stria terminalis disrupts contextually conditioned fear, but not unconditioned fear to a predator odor.

    PubMed

    Asok, Arun; Schulkin, Jay; Rosen, Jeffrey B

    2016-08-01

    The bed nucleus of the stria terminalis (BNST) plays a critical role in fear and anxiety. The BNST is important for contextual fear learning, but the mechanisms regulating this function remain unclear. One candidate mechanism is corticotropin-releasing-factor (CRF) acting at CRF type 1 receptors (CRFr1s). Yet, there has been little progress in elucidating if CRFr1s in the BNST are involved in different types of fear (conditioned and/or unconditioned). Therefore, the present study investigated the effect of antalarmin, a potent CRFr1 receptor antagonist, injected intracerebroventricularly (ICV) and into the dorsolateral BNST (LBNST) during single trial contextual fear conditioning or exposure to the predator odor 2,5-dihydro-2,4,5-trimethylthiazoline (TMT). Neither ICV nor LBNST antalarmin disrupted unconditioned freezing to TMT. In contrast, ICV and LBNST antalarmin disrupted the retention of contextual fear when tested 24h later. Neither ICV nor LBNST antalarmin affected baseline or post-shock freezing-indicating antalarmin does not interfere with the early phases of contextual fear acquisition. Antalarmin did not (1) permanently affect the ability to learn and express contextual fear, (2) change responsivity to footshocks, or (3) affect the ability to freeze. Our findings highlight an important role for CRFr1s within the LBNST during contextually conditioned fear, but not unconditioned predator odor fear. PMID:27153520

  18. Effects of Long-term Blockade of Vasopressin Receptor Types 1a and 2 on Cardiac and Renal Damage in a Rat Model of Hypertensive Heart Failure.

    PubMed

    Ikeda, Tomoyuki; Iwanaga, Yoshitaka; Watanabe, Heitaro; Morooka, Hanako; Akahoshi, Yasumitsu; Fujiki, Hiroyuki; Miyazaki, Shunichi

    2015-11-01

    The effects of chronic blockade of vasopressin type 1a receptors (V1aR) and the additive effects of a type 2 receptor (V2R) antagonist on the treatment of hypertension-induced heart failure and renal injury remain to be unknown. In this study, Dahl salt-sensitive hypertensive rats were chronically treated with a vehicle (CONT), a V1aR antagonist (OPC21268; OPC), a V2R antagonist (tolvaptan; TOLV), or a combination of OPC21268 and tolvaptan (OPC/TOLV) from the pre-hypertrophic stage (6 weeks). No treatment altered blood pressure during the study. Significant improvements were seen in median survival for the OPC and TOLV, and the OPC/TOLV showed a further improvement in Kaplan-Meier analysis. Echocardiography showed suppressed left ventricular hypertrophy in the OPC and OPC/TOLV at 11 weeks with improved function in all treatment groups by 17 weeks. In all treatment groups, improvements were seen in the following: myocardial histological changes, creatinine clearance, urinary albumin excretion, and renal histopathologic damage. Also, key mRNA levels were suppressed (eg, endothelin-1 and collagen). In conclusion, chronic V1aR blockade ameliorated disease progression in this rat model, with additive benefits from the combination of V1aR and V2R antagonists. It was associated with protection of both myocardial and renal damage, independent of blood pressure. PMID:26248278

  19. Control of Toll-like receptor-mediated T cell-independent type 1 antibody responses by the inducible nuclear protein IκB-ζ.

    PubMed

    Hanihara-Tatsuzawa, Fumito; Miura, Hanae; Kobayashi, Shuhei; Isagawa, Takayuki; Okuma, Atsushi; Manabe, Ichiro; MaruYama, Takashi

    2014-11-01

    Antibody responses have been classified as being either T cell-dependent or T cell-independent (TI). TI antibody responses are further classified as being either type 1 (TI-1) or type 2 (TI-2), depending on their requirement for B cell-mediated antigen receptor signaling. Although the mechanistic basis of antibody responses has been studied extensively, it remains unclear whether different antibody responses share similarities in their transcriptional regulation. Here, we show that mice deficient in IκB-ζ, specifically in their B cells, have impaired TI-1 antibody responses but normal T cell-dependent and TI-2 antibody responses. The absence of IκB-ζ in B cells also impaired proliferation triggered by Toll-like receptor (TLR) activation, plasma cell differentiation, and class switch recombination (CSR). Mechanistically, IκB-ζ-deficient B cells could not induce TLR-mediated induction of activation-induced cytidine deaminase (AID), a class-switch DNA recombinase. Retroviral transduction of AID in IκB-ζ-deficient B cells restored CSR activity. Furthermore, acetylation of histone H3 in the vicinity of the transcription start site of the gene that encodes AID was reduced in IκB-ζ-deficient B cells relative to IκB-ζ-expressing B cells. These results indicate that IκB-ζ regulates TLR-mediated CSR by inducing AID. Moreover, IκB-ζ defines differences in the transcriptional regulation of different antibody responses. PMID:25124037

  20. Sensitization of the transient receptor potential vanilloid type 1 ion channel by isoflurane or sevoflurane does not result in extracellular signal-regulated kinase 1/2 activation in rat spinal dorsal horn neurons.

    PubMed

    White, J P M; Cibelli, M; Fidalgo, A R; Paule, C C; Anderson, P J; Jenes, A; Rice, A S C; Nagy, I

    2010-03-17

    Clinically relevant concentrations of isoflurane or sevoflurane sensitize transient receptor potential vanilloid type 1 to several of its activators, including capsaicin. It has, moreover, been suggested these volatile general anaesthetics may augment nociceptive signalling arising from surgical procedures and thereby contribute to post-operative pain. To investigate this suggestion, we have studied intraplantar capsaicin injection-induced phosphorylation of extracellular signal-regulated kinase 1/2 in spinal dorsal horn neurons (which is a recognized marker of spinal nociceptive processing) in rat during isoflurane or sevoflurane anaesthesia after 60 min under anaesthesia. Control animals were anaesthetized with pentobarbital (which of itself does not activate extracellular signal-regulated kinase 1/2 in spinal dorsal horn neurons). Unilateral intraplantar capsaicin injection in control animals evoked extracellular signal-regulated kinase 1/2 phosphorylation in a group of neurons in lamina I and lamina II of the ipsilateral spinal dorsal horn in a somatotopically appropriate area. In contrast, both anaesthetic gases (given for 60 min and without subsequent capsaicin injection) induced extracellular signal-regulated kinase 1/2 activation in a different group of mainly lamina I neurons bilaterally. The total number of spinal dorsal horn neurons labelled on the ipliateral side following capsaicin injection into the isoflurane-, or sevoflurane-, anaesthetized animals was significantly less than that produced by capsaicin alone. Further, capsaicin injection into isoflurane-, or sevoflurane-, anaesthetized animals reduced extracellular signal-regulated kinase 1/2 phosphorylation induced by the gases alone on both sides. These findings do not support the suggestion that isoflurane-, or sevoflurane-, induced sensitization of transient receptor potential vanilloid type 1 by capsaicin, or other agonist, is translated into induction of spinal nociceptive processing and

  1. Assessment of angiotensin II receptor blockade in humans using a standardized angiotensin II receptor-binding assay.

    PubMed

    Maillard, M P; Mazzolai, L; Daven, V; Centeno, C; Nussberger, J; Brunner, H R; Burnier, M

    1999-12-01

    An in vitro angiotensin II (AngII) receptor-binding assay was developed to monitor the degree of receptor blockade in standardized conditions. This in vitro method was validated by comparing its results with those obtained in vivo with the injection of exogenous AngII and the measurement of the AngII-induced changes in systolic blood pressure. For this purpose, 12 normotensive subjects were enrolled in a double-blind, four-way cross-over study comparing the AngII receptor blockade induced by a single oral dose of losartan (50 mg), valsartan (80 mg), irbesartan (150 mg), and placebo. A significant linear relationship between the two methods was found (r = 0.723, n = 191, P<.001). However, there exists a wide scatter of the in vivo data in the absence of active AngII receptor blockade. Thus, the relationship between the two methods is markedly improved (r = 0.87, n = 47, P<.001) when only measurements done 4 h after administration of the drugs are considered (maximal antagonist activity observed in vivo) suggesting that the two methods are equally effective in assessing the degree of AT-1 receptor blockade, but with a greatly reduced variability in the in vitro assay. In addition, the pharmacokinetic/pharmacodynamic analysis performed with the three antagonists suggest that the AT-1 receptor-binding assay works as a bioassay that integrates the antagonistic property of all active drug components of the plasma. This standardized in vitro-binding assay represents a simple, reproducible, and precise tool to characterize the pharmacodynamic profile of AngII receptor antagonists in humans. PMID:10619583

  2. Prolonged Monoacylglycerol Lipase Blockade Causes Equivalent Cannabinoid Receptor Type 1 Receptor–Mediated Adaptations in Fatty Acid Amide Hydrolase Wild-Type and Knockout Mice

    PubMed Central

    Kinsey, Steven G.; Ignatowska-Jankowska, Bogna; Ramesh, Divya; Abdullah, Rehab A.; Tao, Qing; Booker, Lamont; Long, Jonathan Z.; Selley, Dana E.; Cravatt, Benjamin F.; Lichtman, Aron H.

    2014-01-01

    Complementary genetic and pharmacological approaches to inhibit monoacylglycerol lipase (MAGL) and fatty acid amide hydrolase (FAAH), the primary hydrolytic enzymes of the respective endogenous cannabinoids 2-arachidonoylglycerol (2-AG) and N-arachidonoylethanolamine, enable the exploration of potential therapeutic applications and physiologic roles of these enzymes. Complete and simultaneous inhibition of both FAAH and MAGL produces greatly enhanced cannabimimetic responses, including increased antinociception, and other cannabimimetic effects, far beyond those seen with inhibition of either enzyme alone. While cannabinoid receptor type 1 (CB1) function is maintained following chronic FAAH inactivation, prolonged excessive elevation of brain 2-AG levels, via MAGL inhibition, elicits both behavioral and molecular signs of cannabinoid tolerance and dependence. Here, we evaluated the consequences of a high dose of the MAGL inhibitor JZL184 [4-nitrophenyl 4-(dibenzo[d][1,3]dioxol-5-yl(hydroxy)methyl)piperidine-1-carboxylate; 40 mg/kg] given acutely or for 6 days in FAAH(−/−) and (+/+) mice. While acute administration of JZL184 to FAAH(−/−) mice enhanced the magnitude of a subset of cannabimimetic responses, repeated JZL184 treatment led to tolerance to its antinociceptive effects, cross-tolerance to the pharmacological effects of Δ9-tetrahydrocannabinol, decreases in CB1 receptor agonist–stimulated guanosine 5′-O-(3-[35S]thio)triphosphate binding, and dependence as indicated by rimonabant-precipitated withdrawal behaviors, regardless of genotype. Together, these data suggest that simultaneous elevation of both endocannabinoids elicits enhanced cannabimimetic activity but MAGL inhibition drives CB1 receptor functional tolerance and cannabinoid dependence. PMID:24849924

  3. Antagonism of Corticotrophin-Releasing Factor Type 1 Receptors Attenuates Caloric Intake of Free Feeding Subordinate Female Rhesus Monkeys in a Rich Dietary Environment

    PubMed Central

    Moore, C J; Johnson, Z P; Higgins, M; Toufexis, D; Wilson, M E

    2015-01-01

    Social subordination in macaque females is a known chronic stressor and previous studies have shown that socially subordinate female rhesus monkeys consume fewer kilocalories than dominant animals when a typical laboratory chow diet is available. However, in a rich dietary environment that provides access to chow in combination with a more palatable diet (i.e. high in fat and refined sugar), subordinate animals consume significantly more daily kilocalories than dominant conspecifics. Substantial literature is available supporting the role of stress hormone signals in shaping dietary preferences and promoting the consumption of palatable, energy-dense foods. The present study was conducted using stable groups of adult female rhesus monkeys to test the hypothesis that pharmacological treatment with a brain penetrable corticotrophin-releasing factor type 1 receptor (CRF1) antagonist would attenuate the stress-induced consumption of a palatable diet among subordinate animals in a rich dietary environment but would be without effect in dominant females. The results show that administration of the CRF1 receptor antagonist significantly reduced daily caloric intake of both available diets among subordinate females compared to dominant females. Importantly, multiple regression analyses showed that the attenuation in caloric intake in response to Antalarmin (Sigma-Aldrich, St Louis, MO, USA) was significantly predicted by the frequency of submissive and aggressive behaviour emitted by females, independent of social status. Taken together, the findings support the involvement of activation of CRF1 receptors in the stress-induced consumption of excess calories in a rich dietary environment and also support the growing literature concerning the importance of CRF for sustaining emotional feeding. PMID:25674637

  4. A membrane-type-1 matrix metalloproteinase (MT1-MMP)-discoidin domain receptor 1 axis regulates collagen-induced apoptosis in breast cancer cells.

    PubMed

    Assent, Delphine; Bourgot, Isabelle; Hennuy, Benoît; Geurts, Pierre; Noël, Agnès; Foidart, Jean-Michel; Maquoi, Erik

    2015-01-01

    During tumour dissemination, invading breast carcinoma cells become confronted with a reactive stroma, a type I collagen-rich environment endowed with anti-proliferative and pro-apoptotic properties. To develop metastatic capabilities, tumour cells must acquire the capacity to cope with this novel microenvironment. How cells interact with and respond to their microenvironment during cancer dissemination remains poorly understood. To address the impact of type I collagen on the fate of tumour cells, human breast carcinoma MCF-7 cells were cultured within three-dimensional type I collagen gels (3D COL1). Using this experimental model, we have previously demonstrated that membrane type-1 matrix metalloproteinase (MT1-MMP), a proteinase overexpressed in many aggressive tumours, promotes tumour progression by circumventing the collagen-induced up-regulation of BIK, a pro-apoptotic tumour suppressor, and hence apoptosis. Here we performed a transcriptomic analysis to decipher the molecular mechanisms regulating 3D COL1-induced apoptosis in human breast cancer cells. Control and MT1-MMP expressing MCF-7 cells were cultured on two-dimensional plastic plates or within 3D COL1 and a global transcriptional time-course analysis was performed. Shifting the cells from plastic plates to 3D COL1 activated a complex reprogramming of genes implicated in various biological processes. Bioinformatic analysis revealed a 3D COL1-mediated alteration of key cellular functions including apoptosis, cell proliferation, RNA processing and cytoskeleton remodelling. By using a panel of pharmacological inhibitors, we identified discoidin domain receptor 1 (DDR1), a receptor tyrosine kinase specifically activated by collagen, as the initiator of 3D COL1-induced apoptosis. Our data support the concept that MT1-MMP contributes to the inactivation of the DDR1-BIK signalling axis through the cleavage of collagen fibres and/or the alteration of DDR1 receptor signalling unit, without triggering a

  5. Blockade of Rostral Ventrolateral Medulla (RVLM) Bombesin Receptor Type 1 Decreases Blood Pressure and Sympathetic Activity in Anesthetized Spontaneously Hypertensive Rats

    PubMed Central

    Pinto, Izabella S.; Mourão, Aline A.; da Silva, Elaine F.; Camargo, Amanda S.; Marques, Stefanne M.; Gomes, Karina P.; Fajemiroye, James O.; da Silva Reis, Angela A.; Rebelo, Ana C. S.; Ferreira-Neto, Marcos L.; Rosa, Daniel A.; Freiria-Oliveira, André H.; Castro, Carlos H.; Colombari, Eduardo; Colugnati, Diego B.; Pedrino, Gustavo R.

    2016-01-01

    Intrathecal injection of bombesin (BBS) promoted hypertensive and sympathoexcitatory effects in normotensive (NT) rats. However, the involvement of rostral ventrolateral medulla (RVLM) in these responses is still unclear. In the present study, we investigated: (1) the effects of BBS injected bilaterally into RVLM on cardiorespiratory and sympathetic activity in NT and spontaneously hypertensive rats (SHR); (2) the contribution of RVLM BBS type 1 receptors (BB1) to the maintenance of hypertension in SHR. Urethane-anesthetized rats (1.2 g · kg−1, i.v.) were instrumented to record mean arterial pressure (MAP), diaphragm (DIA) motor, and renal sympathetic nerve activity (RSNA). In NT rats and SHR, BBS (0.3 mM) nanoinjected into RVLM increased MAP (33.9 ± 6.6 and 37.1 ± 4.5 mmHg, respectively; p < 0.05) and RSNA (97.8 ± 12.9 and 84.5 ± 18.1%, respectively; p < 0.05). In SHR, BBS also increased DIA burst amplitude (115.3 ± 22.7%; p < 0.05). BB1 receptors antagonist (BIM-23127; 3 mM) reduced MAP (–19.9 ± 4.4 mmHg; p < 0.05) and RSNA (−17.7 ± 3.8%; p < 0.05) in SHR, but not in NT rats (−2.5 ± 2.8 mmHg; −2.7 ± 5.6%, respectively). These results show that BBS can evoke sympathoexcitatory and pressor responses by activating RVLM BB1 receptors. This pathway might be involved in the maintenance of high levels of arterial blood pressure in SHR. PMID:27313544

  6. Receptor Autoradiography Protocol for the Localized Visualization of Angiotensin II Receptors.

    PubMed

    Linares, Andrea; Couling, Leena E; Carrera, Eduardo J; Speth, Robert C

    2016-01-01

    This protocol describes receptor binding patterns for Angiotensin II (Ang II) in the rat brain using a radioligand specific for Ang II receptors to perform receptor autoradiographic mapping. Tissue specimens are harvested and stored at -80 °C. A cryostat is used to coronally section the tissue (brain) and thaw-mount the sections onto charged slides. The slide-mounted tissue sections are incubated in (125)I-SI-Ang II to radiolabel Ang II receptors. Adjacent slides are separated into two sets: 'non-specific binding' (NSP) in the presence of a receptor saturating concentration of non-radiolabeled Ang II, or an AT1 Ang II receptor subtype (AT1R) selective Ang II receptor antagonist, and 'total binding' with no AT1R antagonist. A saturating concentration of AT2 Ang II receptor subtype (AT2R) antagonist (PD123319, 10 µM) is also present in the incubation buffer to limit (125)I-SI-Ang II binding to the AT1R subtype. During a 30 min pre-incubation at ~22 °C, NSP slides are exposed to 10 µM PD123319 and losartan, while 'total binding' slides are exposed to 10 µM PD123319. Slides are then incubated with (125)I-SI-Ang II in the presence of PD123319 for 'total binding', and PD123319 and losartan for NSP in assay buffer, followed by several 'washes' in buffer, and water to remove salt and non-specifically bound radioligand. The slides are dried using blow-dryers, then exposed to autoradiography film using a specialized film and cassette. The film is developed and the images are scanned into a computer for visual and quantitative densitometry using a proprietary imaging system and a spreadsheet. An additional set of slides are thionin-stained for histological comparisons. The advantage of using receptor autoradiography is the ability to visualize Ang II receptors in situ, within a section of a tissue specimen, and anatomically identify the region of the tissue by comparing it to an adjacent histological reference section. PMID:27341008

  7. Heart failure therapeutics on the basis of a biased ligand of the angiotensin-2 type 1 receptor. Rationale and design of the BLAST-AHF study (Biased Ligand of the Angiotensin Receptor Study in Acute Heart Failure).

    PubMed

    Felker, G Michael; Butler, Javed; Collins, Sean P; Cotter, Gad; Davison, Beth A; Ezekowitz, Justin A; Filippatos, Gerasimos; Levy, Phillip D; Metra, Marco; Ponikowski, Piotr; Soergel, David G; Teerlink, John R; Violin, Jonathan D; Voors, Adriaan A; Pang, Peter S

    2015-03-01

    The BLAST-AHF (Biased Ligand of the Angiotensin Receptor Study in Acute Heart Failure) study is designed to test the efficacy and safety of TRV027, a novel biased ligand of the angiotensin-2 type 1 receptor, in patients with acute heart failure (AHF). AHF remains a major public health problem, and no currently-available therapies have been shown to favorably affect outcomes. TRV027 is a novel biased ligand of the angiotensin-2 type 1 receptor that antagonizes angiotensin-stimulated G-protein activation while stimulating β-arrestin. In animal models, these effects reduce afterload while increasing cardiac performance and maintaining stroke volume. In initial human studies, TRV027 appears to be hemodynamically active primarily in patients with activation of the renin-angiotensin-aldosterone system, a potentially attractive profile for an AHF therapeutic. BLAST-AHF is an international prospective, randomized, phase IIb, dose-ranging study that will randomize up to 500 AHF patients with systolic blood pressure ≥120 mm Hg and ≤200 mm Hg within 24 h of initial presentation to 1 of 3 doses of intravenous TRV027 (1, 5, or 25 mg/h) or matching placebo (1:1:1:1) for at least 48 h and up to 96 h. The primary endpoint is a composite of 5 clinical endpoints (dyspnea, worsening heart failure, length of hospital stay, 30-day rehospitalization, and 30-day mortality) combined using an average z-score. Secondary endpoints will include the assessment of dyspnea and change in amino-terminal pro-B-type natriuretic peptide. The BLAST-AHF study will assess the efficacy and safety of a novel biased ligand of the angiotensin-2 type 1 receptor in AHF. PMID:25650371

  8. Effects of β(3)-adrenoceptor activation on expression of pancreatic adrenoceptors and angiotensin II receptors in ApoE(-/-) mice.

    PubMed

    Song, Jun-Ying; Li, Yan-Fang; Jiang, Zhi-Li; Guo, Yan-Qing

    2015-10-01

    Hyperlipidemia can be harmful to the pancreas and β3-adrenoceptor agonist can improve lipid metabolism disorder. We aimed to study the effects of β3-adrenoceptor activation on glucose, insulin and the expression of pancreatic adrenoceptors and angiotensin II receptors. Ten C57BL/6J mice at the age of 10 weeks served as normal control, and forty age-matched apolipoprotein E knockout (ApoE(-/-)) mice were randomly divided into hyperlipidaemia model group, low-dose and high-dose β3-adrenoceptor agonist group and β3-adrenoceptor antagonist group. After 26 weeks of high-fat diet, treatments were given for 12 weeks. Serum glucose and insulin levels in 48 weeks old mice were measured using an automatic biochemical detector. Quantitative rt-PCR and Western blot were used to analyze the mRNA and protein expression of α1A-, α2A-, β2-, β3-adrenoceptors and angiotensin II type 1 and type 2 receptors in pancreas. We found that β3-adrenoceptor agonist could decrease serum glucose and insulin levels in aged ApoE(-/-) mice (P<0.01) and down-regulate the expression of α1A-adrenoceptor and angiotensin II type 1 receptor which were significantly increased in model mice (P<0.05, P<0.01). Compared with the model mice, α2A-, β2-, β3-adrenoceptor and angiotensin II type 2 receptor expression were up-regulated in β3-adrenoceptor agonist treat mice (P<0.05, P<0.01). These results suggest that chronic β3-adrenoceptor activation regulated the expression of adrenoceptors and angiontensin II receptors towards contrary direction, which indicates that there are interactions between β3-adrenoceptor and subtypes of adrenoceptor and angiotensin II receptor, and these interactions may play a protective role in pancreas and improve glucose metabolism disorders. PMID:26102566

  9. Angiotensin II AT(1) receptor blockers as treatments for inflammatory brain disorders.

    PubMed

    Saavedra, Juan M

    2012-11-01

    The effects of brain AngII (angiotensin II) depend on AT(1) receptor (AngII type 1 receptor) stimulation and include regulation of cerebrovascular flow, autonomic and hormonal systems, stress, innate immune response and behaviour. Excessive brain AT(1) receptor activity associates with hypertension and heart failure, brain ischaemia, abnormal stress responses, blood-brain barrier breakdown and inflammation. These are risk factors leading to neuronal injury, the incidence and progression of neurodegerative, mood and traumatic brain disorders, and cognitive decline. In rodents, ARBs (AT(1) receptor blockers) ameliorate stress-induced disorders, anxiety and depression, protect cerebral blood flow during stroke, decrease brain inflammation and amyloid-β neurotoxicity and reduce traumatic brain injury. Direct anti-inflammatory protective effects, demonstrated in cultured microglia, cerebrovascular endothelial cells, neurons and human circulating monocytes, may result not only in AT(1) receptor blockade, but also from PPARγ (peroxisome-proliferator-activated receptor γ) stimulation. Controlled clinical studies indicate that ARBs protect cognition after stroke and during aging, and cohort analyses reveal that these compounds significantly reduce the incidence and progression of Alzheimer's disease. ARBs are commonly used for the therapy of hypertension, diabetes and stroke, but have not been studied in the context of neurodegenerative, mood or traumatic brain disorders, conditions lacking effective therapy. These compounds are well-tolerated pleiotropic neuroprotective agents with additional beneficial cardiovascular and metabolic profiles, and their use in central nervous system disorders offers a novel therapeutic approach of immediate translational value. ARBs should be tested for the prevention and therapy of neurodegenerative disorders, in particular Alzheimer's disease, affective disorders, such as co-morbid cardiovascular disease and depression, and traumatic

  10. Angiotensin II AT1 receptor blockers as treatments for inflammatory brain disorders

    PubMed Central

    SAAVEDRA, Juan M.

    2012-01-01

    The effects of brain AngII (angiotensin II) depend on AT1 receptor (AngII type 1 receptor) stimulation and include regulation of cerebrovascular flow, autonomic and hormonal systems, stress, innate immune response and behaviour. Excessive brain AT1 receptor activity associates with hypertension and heart failure, brain ischaemia, abnormal stress responses, blood–brain barrier breakdown and inflammation. These are risk factors leading to neuronal injury, the incidence and progression of neurodegerative, mood and traumatic brain disorders, and cognitive decline. In rodents, ARBs (AT1 receptor blockers) ameliorate stress-induced disorders, anxiety and depression, protect cerebral blood flow during stroke, decrease brain inflammation and amyloid-β neurotoxicity and reduce traumatic brain injury. Direct anti-inflammatory protective effects, demonstrated in cultured microglia, cerebrovascular endothelial cells, neurons and human circulating monocytes, may result not only in AT1 receptor blockade, but also from PPARγ (peroxisome-proliferator-activated receptor γ) stimulation. Controlled clinical studies indicate that ARBs protect cognition after stroke and during aging, and cohort analyses reveal that these compounds significantly reduce the incidence and progression of Alzheimer’s disease. ARBs are commonly used for the therapy of hypertension, diabetes and stroke, but have not been studied in the context of neurodegenerative, mood or traumatic brain disorders, conditions lacking effective therapy. These compounds are well-tolerated pleiotropic neuroprotective agents with additional beneficial cardiovascular and metabolic profiles, and their use in central nervous system disorders offers a novel therapeutic approach of immediate translational value. ARBs should be tested for the prevention and therapy of neurodegenerative disorders, in particular Alzheimer’s disease, affective disorders, such as co-morbid cardiovascular disease and depression, and traumatic

  11. Angiotensin II receptor blockade in normotensive subjects: A direct comparison of three AT1 receptor antagonists.

    PubMed

    Mazzolai, L; Maillard, M; Rossat, J; Nussberger, J; Brunner, H R; Burnier, M

    1999-03-01

    Use of angiotensin (Ang) II AT1 receptor antagonists for treatment of hypertension is rapidly increasing, yet direct comparisons of the relative efficacy of antagonists to block the renin-angiotensin system in humans are lacking. In this study, the Ang II receptor blockade induced by the recommended starting dose of 3 antagonists was evaluated in normotensive subjects in a double-blind, placebo-controlled, randomized, 4-way crossover study. At 1-week intervals, 12 subjects received a single dose of losartan (50 mg), valsartan (80 mg), irbesartan (150 mg), or placebo. Blockade of the renin-angiotensin system was assessed before and 4, 24, and 30 hours after drug intake by 3 independent methods: inhibition of the blood pressure response to exogenous Ang II, in vitro Ang II receptor assay, and reactive changes in plasma Ang II levels. At 4 hours, losartan blocked 43% of the Ang II-induced systolic blood pressure increase; valsartan, 51%; and irbesartan, 88% (P<0.01 between drugs). The effect of each drug declined with time. At 24 hours, a residual effect was found with all 3 drugs, but at 30 hours, only irbesartan induced a marked, significant blockade versus placebo. Similar results were obtained when Ang II receptor blockade was assessed with an in vitro receptor assay and by the reactive rise in plasma Ang II levels. This study thus demonstrates that the first administration of the recommended starting dose of irbesartan induces a greater and longer lasting Ang II receptor blockade than that of valsartan and losartan in normotensive subjects. PMID:10082498

  12. Human type II receptor for bone morphogenic proteins (BMPs): extension of the two-kinase receptor model to the BMPs.

    PubMed Central

    Liu, F; Ventura, F; Doody, J; Massagué, J

    1995-01-01

    Bone morphogenic proteins (BMPs) are universal regulators of animal development. We report the identification and cloning of the BMP type II receptor (BMPR-II), a missing component of this receptor system in vertebrates. BMPR-II is a transmembrane serine/threonine kinase that binds BMP-2 and BMP-7 in association with multiple type I receptors, including BMPR-IA/Brk1, BMPR-IB, and ActR-I, which is also an activin type I receptor. Cloning of BMPR-II resulted from a strong interaction of its cytoplasmic domain with diverse transforming growth factor beta family type I receptor cytoplasmic domains in a yeast two-hybrid system. In mammalian cells, however, the interaction of BMPR-II is restricted to BMP type I receptors and is ligand dependent. BMPR-II binds BMP-2 and -7 on its own, but binding is enhanced by coexpression of type I BMP receptors. BMP-2 and BMP-7 can induce a transcriptional response when added to cells coexpressing ActR-I and BMPR-II but not to cells expressing either receptor alone. The kinase activity of both receptors is essential for signaling. Thus, despite their ability to bind to type I and II receptors receptors separately, BMPs appear to require the cooperation of these two receptors for optimal binding and for signal transduction. The combinatorial nature of these receptors and their capacity to crosstalk with the activin receptor system may underlie the multifunctional nature of their ligands. PMID:7791754

  13. Surinabant, a selective cannabinoid receptor type 1 antagonist, inhibits Δ9-tetrahydrocannabinol-induced central nervous system and heart rate effects in humans

    PubMed Central

    Klumpers, Linda E; Roy, Christine; Ferron, Geraldine; Turpault, Sandrine; Poitiers, Franck; Pinquier, Jean-Louis; van Hasselt, Johan G C; Zuurman, Lineke; Erwich, Frank A S; van Gerven, Joop M A

    2013-01-01

    Aim Cannabinoid receptor type 1 (CB1) antagonists have been developed for the treatment of obesity and associated risk factors. Surinabant is a high affinity CB1 antagonist in vitro. The aim of this study was to assess the magnitude of inhibition by surinabant of CNS effects and heart rate induced by Δ9-tetrahydrocannabinol (THC) in humans. Methods This was a double-blind, placebo-controlled, randomized, four period six sequence crossover study. Thirty healthy young male occasional cannabis users (<1 per week) were included. A single oral dose of surinabant (5, 20 or 60 mg) or placebo was administered followed 1.5 h later by four intrapulmonary THC doses (2, 4, 6 and 6 mg) or vehicle, administered at 1 h intervals. The wash-out period was 14–21 days. Subjective and objective pharmacodynamic (PD) measurements were performed. A population PK–PD model for THC and surinabant quantified PK and PD effects. Results Surinabant 20 and 60 mg inhibited all THC-induced PD effects in a similar range for both doses with inhibition ratios ranging from 68.3% (95% CI = 32.5, 104.2; heart rate) to 91.1% (95% CI = 30.3, 151.8; body sway). IC50 ranged from 22.0 ng ml−1 [relative standard error (RSE) = 45.2%; body sway] to 58.8 ng ml−1 (RSE = 44.2%; internal perception). Surinabant 5 mg demonstrated no significant effects. Conclusions The dose-related inhibition by surinabant, without any effect of its own, suggests that this compound behaves as a CB1 receptor antagonist in humans at these concentrations. A single surinabant dose between 5 to 20 mg and above was able to antagonize THC-induced effects in humans. PMID:23278647

  14. Blockade of tumor necrosis factor (TNF) receptor type 1-mediated TNF-alpha signaling protected Wistar rats from diet-induced obesity and insulin resistance.

    PubMed

    Liang, Huifang; Yin, Bingjiao; Zhang, Hailong; Zhang, Shu; Zeng, Qingling; Wang, Jing; Jiang, Xiaodan; Yuan, Li; Wang, Cong-Yi; Li, Zhuoya

    2008-06-01

    TNF-alpha plays an important role in the pathogenesis of obesity and insulin resistance in which the effect of TNF-alpha signaling via TNF receptor type 1 (TNFR1) largely remains controversial. To delineate the role of TNFR1-mediated TNF-alpha signaling in the pathogenesis of this disorder, a TNFR1 blocking peptide-Fc fusion protein (TNFR1BP-Fc) was used for the present study. Wistar rats were fed a high-fat/high-sucrose (HFS) diet for 16 wk until obesity and insulin resistance developed. In comparison with increased body weight and fat weight, enlarged adipocytes, and hypertriglyceridemia in the obese state, the subsequent 4-wk treatment with TNFR1BP-Fc resulted in significant weight loss characterized by decreased fat pad weight and adipocyte size and reduced plasma triglycerides. Furthermore, obesity-induced insulin resistance, including hyperinsulinemia, elevated C-peptide, higher degree of hyperglycemia after glucose challenge, and less hypoglycemic response to insulin, was markedly improved, and the compensatory hyperplasia and hypertrophy of pancreatic islets were reduced. Interestingly, treatment with TNFR1BP-Fc markedly suppressed systemic TNF-alpha release and its local expression in pancreatic islets and muscle and adipose tissues. In addition, blockage of TNFR1-mediated TNF-alpha signaling in obese rats significantly enhanced tyrosine phosphorylation of insulin receptor substrate 1 (IRS-1) in the muscle and fat tissues. Our results strongly suggest a pivotal role for TNFR1-mediated TNF-alpha signaling in the pathogenesis of obesity and insulin resistance. Thus, TNFR1BP-Fc may be a good candidate for the treatment of this disease. PMID:18339717

  15. Involvement of toll-like receptors 3 and 7/8 in the neuropathogenesis of bovine herpesvirus types 1 and 5.

    PubMed

    Rensetti, Daniel; Marin, Maia; Quintana, Silvina; Morán, Pedro; Verna, Andrea; Odeón, Anselmo; Pérez, Sandra

    2016-08-01

    Bovine herpesvirus types 1 (BoHV-1) and 5 (BoHV-5) are closely related alpha-herpesviruses. BoHV-5 is the causal agent of non-suppurative meningoencephalitis in calves. BoHV-1 causes respiratory disease, abortions, genital disorders and, occasionally, encephalitis in cattle. Both viruses are neurotropic and they share similar biological properties. Nevertheless, they differ in their ability to cause neurological disease. Toll-like receptors (TLRs) are involved in the innate immune response to pathogens. In this study, the variations in the expression levels of TLRs were evaluated in different regions of the bovine central nervous system during the acute infection and reactivation of BoHV-1 and BoHV-5- infected cattle. With the exception of TLR9, significant up-regulation of all TLRs was detected following primary infection of neural tissues by both bovine alpha-herpesviruses. Furthermore, the stages of acute infection and reactivation were characterized by a distinguishable TLR expression pattern. Important differences in TLR expression upon infection of the central nervous system by BoHV-1 or BoHV-5 were not detected. The striking differences in TLR mRNA levels during acute infection and reactivation provide evidence that the innate immune response may be involved in the clinical outcomes observed at each stage. Further research is required to analyze the mechanisms that initiate TLR activation and the signaling cascade mediated by each TLR to elucidate the precise role these receptors play in bovine herpesvirus encephalitis. PMID:27473967

  16. The Effects of Melatonin on Brain Arginine Vasotocin: Relationship with Sex and Seasonal Differences in Melatonin Receptor Type 1 in Green Treefrogs (Hyla cinerea).

    PubMed

    Howard, C M; Lutterschmidt, D I

    2015-08-01

    The neuroendocrine mechanisms by which animals synchronise their physiological state with environmental cues are vital to timing life-history events appropriately. One important endocrine transducer of environmental cues in vertebrates is the pineal hormone melatonin, the secretion of which is directly sensitive to photoperiod and temperature. Melatonin modulates arginine vasotocin (AVT)-immunoreactive (-IR) cell number in the brain of green treefrogs (Hyla cinerea) during the summer breeding season, and this modulation is sexually dimorphic. In the present study, we investigated whether the influence of melatonin on vasotocin varies seasonally. We show that treatment of nonreproductive male green treefrogs with melatonin-filled silastic implants for 4 weeks during the winter does not alter vasotocin-IR cell number in any brain region (i.e. nucleus accumbens, amygdala, preoptic area, suprachiasmatic nucleus or ventral hypothalamus). Taken together, these results suggest that the influence of melatonin on AVT is associated with sex and seasonal variation in melatonin receptor expression. We tested this hypothesis by using immunohistochemistry to characterise the distribution of melatonin receptor type 1 (MT1, also known as Mel1a) in the brain of reproductive and nonreproductive male and female frogs. We quantified MT1-IR cell number in regions known to contain AVT cell populations. Reproductive males had significantly more MT1-IR cells than nonreproductive males in all brain regions, including the combined nucleus accumbens, diagonal band of Broca and septum, striatum, amygdala, combined preoptic area and suprachiasmatic nucleus, as well as the ventral hypothalamus. In the accumbens region, where the effect of melatonin on AVT is known to be sexually dimorphic, males had significantly more MT1-IR cells than females during the summer breeding season. Based on these findings, we suggest that MT1 plays a role in mediating the interactions between melatonin and

  17. Test–retest reproducibility of cannabinoid-receptor type 1 availability quantified with the PET ligand [11C]MePPEP

    PubMed Central

    Riaño Barros, Daniela A.; McGinnity, Colm J.; Rosso, Lula; Heckemann, Rolf A.; Howes, Oliver D.; Brooks, David J.; Duncan, John S.; Turkheimer, Federico E.; Koepp, Matthias J.; Hammers, Alexander

    2014-01-01

    Background Endocannabinoids are involved in normal cognition, and dysfunction in cannabinoid-receptor-mediated neurotransmission has been suggested in a variety of neurological and psychiatric pathologies. The type 1 cannabinoid receptor (CB1) is widely expressed in the human central nervous system. The objective of this study was to quantify the test–retest reproducibility of measures of the PET ligand [11C]MePPEP in order to assess the stability of CB1-receptor quantification in humans in vivo. Methods Fifteen healthy subjects (eight females; median age 32 years, range 25 to 65 years) had a 90-minute PET scan on two occasions after injection of a median dose of [11C]MePPEP of 364 MBq. Metabolite-corrected arterial plasma input functions were obtained for all scans. Eight ROIs, reflecting different levels of receptor densities/concentrations, were defined automatically: hippocampus, anterior cingulate gyrus, inferior frontal gyrus, caudate nucleus, globus pallidus, nucleus accumbens, thalamus, and pons. We used seven quantification methods: reversible compartmental models with one and two tissue classes, two and four rate constants, and a variable blood volume term (2kbv; 4kbv); model-free (spectral) analyses with and without regularisation, including one with voxel-wise quantification; the simplified reference tissue model (SRTM) with pons as a pseudo-reference region; and modified standard uptake values (mSUVs) calculated for the period of ~ 30–60 min after injection. Percentage test–retest change and between-subject variability were both assessed, and test–retest reliability was quantified by the intraclass correlation coefficient (ICC). The ratio of binding estimates pallidum:pons served as an indicator of a method's ability to reflect binding heterogeneity. Results Neither the SRTM nor the 4kbv model produced reliable measures, with ICCs around zero. Very good (> 0.75) or excellent (> 0.80) ICCs were obtained with the other methods. The most

  18. Reduced proximal tubule angiotensin II receptor expression in streptozotocin-induced diabetes mellitus.

    PubMed

    Cheng, H F; Burns, K D; Harris, R C

    1994-12-01

    Diabetes mellitus is characterized by alterations in the intrarenal renin-angiotensin system, including decreases in glomerular angiotensin II (Ang II) receptor density. Since Ang II regulates proximal tubule transport function, the present studies examined whether diabetes altered expression of proximal tubule receptors. In basolateral membranes from 14 day streptozotocin-induced diabetic rats, specific binding of 125I Ang II was decreased to 53 +/- 8% of control (3.2 +/- 0.5 vs. 1.5 +/- 0.2 fmol/mg protein; N = 7; P < 0.02). Similarly, in proximal tubule brush border membranes from diabetic animals, specific binding was decreased to 63 +/- 11% of control (1.1 +/- 0.2 vs 0.6 +/- 0.1 fmol/mg protein; N = 9; P < 0.05). Concomitant insulin treatment reversed the decrease in specific binding of 125I Ang II to basolateral membranes (109 +/- 26% of control; N = 3) and to brush border membranes (85 +/- 17% of control; N = 6). In order to determine if changes in expression of type-1 Ang II receptors (AT1R) accompanied the changes in binding, quantitative polymerase chain reaction of AT1R mRNA was performed and expressed as the ratio of the amplified AT1R to that of an Msc1/Msc1 internal deletion mutant and normalized to that of beta-actin. In total RNA from proximal tubule suspensions of diabetic animals, AT1R mRNA expression decreased by 38% (21 +/- 3 vs. 13 +/- 2 cpm AT1R/cpm deletion mutant/cpm beta actin/10(6); N = 4; P < 0.0025). Insulin treatment reverted AT1R mRNA expression to control levels (22 +/- 3 cpm AT1R/cpm deletion mutant/cpm beta actin/10(6); P < 0.001 compared to the untreated group).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7700017

  19. Human inositol 1,4,5-trisphosphate type-1 receptor, InsP3R1: structure, function, regulation of expression and chromosomal localization.

    PubMed Central

    Yamada, N; Makino, Y; Clark, R A; Pearson, D W; Mattei, M G; Guénet, J L; Ohama, E; Fujino, I; Miyawaki, A; Furuichi, T

    1994-01-01

    We have isolated cDNA clones encoding an inositol 1,4,5-trisphosphate receptor type 1 (InsP3R1) from human uteri and a leukaemic cell line, HL-60. Northern-blot analysis showed that approx. 10 kb of InsP3R1 mRNA is expressed in human uteri, oviducts and HL-60 cells. The predicted amino acid sequence of human InsP3R1 (2695 amino acids) has 99% identity with that of the mouse SI-/SII- splicing counterpart. Western-blot analysis with anti-(mouse InsP3R1) antibodies showed that InsP3R1 protein of human uteri and oviducts of approx 220 kDa is immunostained. Northern-blot analysis of HL-60 cell differentiation along the neutrophilic lineage induced by retinoic acid or dimethylsulphoxide showed an accompanying enhanced expression of InsP3R1 mRNA. Immunohistochemical analysis of the cerebella of spinocerebellar degeneration patients showed a variable loss of Purkinje cells with an altered pattern of immunostaining. The InsP3R1 gene (Insp3r1) was localized to the 3P25-26 region of human chromosome 3. The data presented here clearly show that InsP3R1 exists widely in human tissues and may play critical roles in various kinds of cellular functions. Images Figure 2 Figure 3 Figure 5 Figure 6 Figure 7 Figure 8 PMID:7945203

  20. Antibody Inhibition of a Viral Type 1 Interferon Decoy Receptor Cures a Viral Disease by Restoring Interferon Signaling in the Liver

    PubMed Central

    Xu, Ren-Huan; Rubio, Daniel; Roscoe, Felicia; Krouse, Tracy E.; Truckenmiller, Mary Ellen; Norbury, Christopher C.; Hudson, Paul N.; Damon, Inger K.; Alcamí, Antonio; Sigal, Luis J.

    2012-01-01

    Type 1 interferons (T1-IFNs) play a major role in antiviral defense, but when or how they protect during infections that spread through the lympho-hematogenous route is not known. Orthopoxviruses, including those that produce smallpox and mousepox, spread lympho-hematogenously. They also encode a decoy receptor for T1-IFN, the T1-IFN binding protein (T1-IFNbp), which is essential for virulence. We demonstrate that during mousepox, T1-IFNs protect the liver locally rather than systemically, and that the T1-IFNbp attaches to uninfected cells surrounding infected foci in the liver and the spleen to impair their ability to receive T1-IFN signaling, thus facilitating virus spread. Remarkably, this process can be reversed and mousepox cured late in infection by treating with antibodies that block the biological function of the T1-IFNbp. Thus, our findings provide insights on how T1-IFNs function and are evaded during a viral infection in vivo, and unveil a novel mechanism for antibody-mediated antiviral therapy. PMID:22241999

  1. The type 1 Interleukin 1 receptor is not required for the death of murine hippocampal dentate granule cells and microglia activation

    PubMed Central

    Harry, G. Jean; Funk, Jason; Lefebvre d’Hellencourt, Christian; Aoyama, Mineyoshi

    2008-01-01

    Alterations in the inflammatory process, neuronal death, and glia response have been observed under manipulation of the interleukin-1 (IL-1) cytokine and subsequent signaling through the type 1 IL-1 receptor (IL-1R1). To investigate the influence of IL-1R1 activation in the pathophysiology of a chemical-induced injury to the murine hippocampus, we examined the level and pattern of neuronal death and neuroinflammation in 25-day-old male mice exposed to trimethyltin hydroxide (2.0 mg/kg, i.p.). In IL-1R1 null (IL-1R1−/−) mice, the pattern and severity of dentate granule cell death was similar as compared to wild type mice. In both groups of mice, mRNA levels for TNFα and MIP-1α were elevated and the early activation of microglia, including their ability to progress to a phagocytic phenotype, was maintained. Compared to WT mice, IL-1R1−/− mice displayed a limited glial fibrillary acidic protein (GFAP) astrocytic response, as well as a preferential induction in mRNA levels of Fas signaling components. Cumulatively, these results indicate that IL-1R1 activation is not necessary for TMT-induced death of dentate granule neurons or local activation of microglia; however, IL-1R1 signaling is involved in mediating the structural response of astrocytes to injury and may also regulate apoptotic mechanisms by influencing Fas signaling components. PMID:18191113

  2. The let-7g microRNA promotes follicular granulosa cell apoptosis by targeting transforming growth factor-β type 1 receptor.

    PubMed

    Zhou, Jilong; Liu, Jiying; Pan, Zengxiang; Du, Xing; Li, Xinyu; Ma, Baiquan; Yao, Wang; Li, Qifa; Liu, Honglin

    2015-07-01

    The intronic microRNA let-7g controls cell differentiation and proliferation during angiogenesis and oncogenesis. Here, we demonstrate that let-7g regulates granulosa cell (GC) apoptosis and follicular atresia in the pig ovary. Bioinformatics analyses and luciferase reporter assays showed that transforming growth factor-β type 1 receptor (TGFBR1) is a let-7g target. Overexpression of let-7g induced apoptosis of porcine GCs in vitro and repressed the mRNA and protein levels of TGFBR1, as well as the level of phosphorylated SMAD3 (p-SMAD3) protein. RNA interference-mediated knockdown of TGFBR1 and inhibitor LY2157299-mediated blocking of TGFBR1 significantly increased the rate of apoptosis of GCs and Caspase-3 activity. In addition, treatment of porcine GCs with TGF-β1 reduced the level of let-7g and increased the levels of the TGFBR1 mRNA and proteins significantly. Overall, these results demonstrate that let-7g regulates the apoptosis of GCs in the pig ovary by targeting TGFBR1 and down-regulating the TGF-β signaling pathway. PMID:25817543

  3. Up-regulated expression of scavenger receptor class B type 1 (SR-B1) is associated with malignant behaviors and poor prognosis of breast cancer.

    PubMed

    Li, Juan; Wang, Jing; Li, Ming; Yin, Linlin; Li, Xiang-An; Zhang, Ting-Guo

    2016-06-01

    Scavenger receptor class B type 1 (SR-B1) is an integral membrane protein that is expressed in numerous cells and tissue types. The primary role of SR-B1 is to facilitate uptake of cholesteryl esters from high-density lipoproteins (HDL) in the liver. Altered SR-B1 expression contributes to human diseases. This study assessed association of SR-B1 expression in breast tissue specimens with breast cancer development and prognosis. Tissue specimens from 30 cases of adjacent normal breast tissues, ductal carcinoma in situ (DCIS) and invasive ductal breast cancer (IDCA) were subjected to Western blot analysis, and 135 cases of DCIS and IDCA were used for quantitative immunohistochemical analysis of SR-B1 expression. The data showed that SR-B1 was significantly overexpressed in IDCA tissues compared to normal breast and DCIS tissues. SR-B1 expression was associated with pre-menopausal status, tumor size, and worse overall survival of patients. The data from this ex vivo study suggests that up-regulated SR-B1 protein expression is associated with malignant behaviors of breast cancer and that SR-B1 is an independent predictor for poor survival in breast cancer patients. PMID:27067809

  4. Nitric Oxide-Induced Calcium Release: Activation of Type 1 Ryanodine Receptor, a Calcium Release Channel, through Non-Enzymatic Post-Translational Modification by Nitric Oxide

    PubMed Central

    Kakizawa, Sho

    2013-01-01

    Nitric oxide (NO) is a typical gaseous messenger involved in a wide range of biological processes. In our classical knowledge, effects of NO are largely achieved by activation of soluble guanylyl cyclase to form cyclic guanosine-3′, 5′-monophosphate. However, emerging evidences have suggested another signaling mechanism mediated by NO: “S-nitrosylation” of target proteins. S-nitrosylation is a covalent addition of an NO group to a cysteine thiol/sulfhydryl (RSH), and categorized into non-enzymatic post-translational modification (PTM) of proteins, contrasted to enzymatic PTM of proteins, such as phosphorylation mediated by various protein kinases. Very recently, we found novel intracellular calcium (Ca2+) mobilizing mechanism, NO-induced Ca2+ release (NICR) in cerebellar Purkinje cells. NICR is mediated by type 1 ryanodine receptor (RyR1), a Ca2+ release channel expressed in endoplasmic-reticular membrane. Furthermore, NICR is indicated to be dependent on S-nitrosylation of RyR1, and involved in synaptic plasticity in the cerebellum. In this review, molecular mechanisms and functional significance of NICR, as well as non-enzymatic PTM of proteins by gaseous signals, are described. PMID:24130553

  5. Possible involvement of the transient receptor potential vanilloid type 1 channel in postoperative adhesive obstruction and its prevention by a kampo (traditional Japanese) medicine, daikenchuto.

    PubMed

    Tokita, Yohei; Yamamoto, Masahiro; Satoh, Kazuko; Nishiyama, Mitsue; Iizuka, Seiichi; Imamura, Sachiko; Kase, Yoshio

    2011-01-01

    This study focused on the localization of transient receptor potential vanilloid type 1 (TRPV1) in the intestines in postoperative adhesion model rats and investigated the underlying mechanism for the anti-adhesion action of daikenchuto (DKT), especially in relation to TRPV1. Postoperative intestinal adhesion was induced by sprinkling talc in the small intestine. The expression of TRPV1 mRNA was examined by in situ hybridization and real-time RT-PCR. The effects of DKT and its major ingredient, hydroxy sanshool, with or without ruthenium red, a TRP-channel antagonist, on talc-induced intestinal adhesions were evaluated. The level of TRPV1 mRNA was higher in the adhesion regions of talc-treated rats than in normal small intestine of sham-operated rats. Localization of TRPV1 mRNA expression was identified in the submucosal plexus of both sham-operated and talc-treated rats; and in talc-treated rats, it was observed also in the myenteric plexus and regions of adhesion. Capsaicin, DKT, and hydroxy sanshool significantly prevented formation of intestinal adhesions. The effects of DKT and hydroxy sanshool were abrogated by subcutaneous injection of ruthenium red. These results suggest that pharmacological modulation of TRPV1 might be a possible therapeutic option in postoperative intestinal adhesion, which might be relevant to the prevention of postoperative adhesive obstruction by DKT. PMID:21186335

  6. Angiotensin type 1a receptors in the paraventricular nucleus of the hypothalamus control cardiovascular reactivity and anxiety-like behavior in male mice.

    PubMed

    Wang, Lei; Hiller, Helmut; Smith, Justin A; de Kloet, Annette D; Krause, Eric G

    2016-09-01

    This study tested the hypothesis that deletion of angiotensin type 1a receptors (AT1a) from the paraventricular nucleus of hypothalamus (PVN) attenuates anxiety-like behavior, hypothalamic-pituitary-adrenal (HPA) axis activity, and cardiovascular reactivity. We used the Cre/LoxP system to generate male mice with AT1a specifically deleted from the PVN. Deletion of the AT1a from the PVN reduced anxiety-like behavior as indicated by increased time spent in the open arms of the elevated plus maze. In contrast, PVN AT1a deletion had no effect on HPA axis activation subsequent to an acute restraint challenge but did reduce hypothalamic mRNA expression for corticotropin-releasing hormone (CRH). To determine whether PVN AT1a deletion inhibits cardiovascular reactivity, we measured systolic blood pressure, heart rate, and heart rate variability (HRV) using telemetry and found that PVN AT1a deletion attenuated restraint-induced elevations in systolic blood pressure and elicited changes in HRV indicative of reduced sympathetic nervous activity. Consistent with the decreased HRV, PVN AT1a deletion also decreased adrenal weight, suggestive of decreased adrenal sympathetic outflow. Interestingly, the altered stress responsivity of mice with AT1a deleted from the PVN was associated with decreased hypothalamic microglia and proinflammatory cytokine expression. Collectively, these results suggest that deletion of AT1a from the PVN attenuates anxiety, CRH gene transcription, and cardiovascular reactivity and reduced brain inflammation may contribute to these effects. PMID:27468749

  7. The immunoexpression of androgen receptor, estrogen receptors alpha and beta, vanilloid type 1 receptor and cytochrome p450 aromatase in rats testis chronically treated with letrozole, an aromatase inhibitor.

    PubMed

    Pilutin, Anna; Misiakiewicz-Has, Kamila; Kolasa, Agnieszka; Baranowska-Bosiacka, Irena; Marchlewicz, Mariola; Wiszniewska, Barbara

    2014-01-01

    The function of testis is under hormonal control and any disturbance of hormonal homeostasis can lead to morphological and physiological changes. Therefore the aim of the study was to investigate the expression of androgen and estrogen receptors (AR, ERs), vanilloid receptor (TRPV1), cytochrome P450 aromatase (P450arom), as well as apoptosis of cells in testis of adult rats chronically treated with letrozole (LT), a non-steroidal aromatase inhibitor, for 6 months. The testicular tissues were fixed in Bouin's fixative and embedded in paraffin. Immunohistochemistry with monoclonal antibodies (abs) against AR, ERa, P450arom, and polyclonalabs against ERβ, TRPV1, caspase-3 was applied. Long-lasting estradiol deficiency, as an effect of LT treatment, produced changes in the morphology of testis and altered the expression of the studied receptors in cells of the seminiferous tubules and rate of cell apoptosis. The immunostaining for AR was found in the nuclei of Sertoli cells and the cytoplasm of spermatogonia and spermatocytes in III-IV stages of the seminiferous epithelium cycle. The intensity of staining for P450arom was lower in the testis of LT-treated rats as compared to control animals. The immunofluorescence of ERα and ERβ was observed exclusively in the nuclei of Leydig cells of LT-treated rats. There were no changes in localization of TRPV1, however, the intensity of reaction was stronger in germ cells of the seminiferous epithelium after LT treatment. The apoptosis in both groups of animals was observed within the population of spermatocytes and spermatids in II and III stages of the seminiferous epithelium cycle. In testis of LT-treated rats the immunoexpression of caspase-3 was additionally found in the germ cells in I and IV stages, and Sertoli, myoid and Leydig cells. In conclusion, our results underline the important role of letrozole treatment in the proper function of male reproductive system, and additionally demonstrate that hormonal imbalance can

  8. Acute ethanol intake induces superoxide anion generation and mitogen-activated protein kinase phosphorylation in rat aorta: A role for angiotensin type 1 receptor

    SciTech Connect

    Yogi, Alvaro; Callera, Glaucia E.; Mecawi, André S.; Batalhão, Marcelo E.; Carnio, Evelin C.; Antunes-Rodrigues, José; Queiroz, Regina H.; Touyz, Rhian M.; Tirapelli, Carlos R.

    2012-11-01

    Ethanol intake is associated with increase in blood pressure, through unknown mechanisms. We hypothesized that acute ethanol intake enhances vascular oxidative stress and induces vascular dysfunction through renin–angiotensin system (RAS) activation. Ethanol (1 g/kg; p.o. gavage) effects were assessed within 30 min in male Wistar rats. The transient decrease in blood pressure induced by ethanol was not affected by the previous administration of losartan (10 mg/kg; p.o. gavage), a selective AT{sub 1} receptor antagonist. Acute ethanol intake increased plasma renin activity (PRA), angiotensin converting enzyme (ACE) activity, plasma angiotensin I (ANG I) and angiotensin II (ANG II) levels. Ethanol induced systemic and vascular oxidative stress, evidenced by increased plasma thiobarbituric acid-reacting substances (TBARS) levels, NAD(P)H oxidase‐mediated vascular generation of superoxide anion and p47phox translocation (cytosol to membrane). These effects were prevented by losartan. Isolated aortas from ethanol-treated rats displayed increased p38MAPK and SAPK/JNK phosphorylation. Losartan inhibited ethanol-induced increase in the phosphorylation of these kinases. Ethanol intake decreased acetylcholine-induced relaxation and increased phenylephrine-induced contraction in endothelium-intact aortas. Ethanol significantly decreased plasma and aortic nitrate levels. These changes in vascular reactivity and in the end product of endogenous nitric oxide metabolism were not affected by losartan. Our study provides novel evidence that acute ethanol intake stimulates RAS activity and induces vascular oxidative stress and redox-signaling activation through AT{sub 1}-dependent mechanisms. These findings highlight the importance of RAS in acute ethanol-induced oxidative damage. -- Highlights: ► Acute ethanol intake stimulates RAS activity and vascular oxidative stress. ► RAS plays a role in acute ethanol-induced oxidative damage via AT{sub 1} receptor activation.

  9. Targeting the Insulin-Like Growth Factor (IGF) System Is Not as Simple as Just Targeting the Type 1 IGF Receptor.

    PubMed

    Scotlandi, Katia; Belfiore, Antonino

    2012-01-01

    Increased signaling of the insulin-like growth factor (IGF) system via alterations in expression levels of its components has been demonstrated in various tumor types. Numerous experimental studies have supported the involvement of the IGF system signaling axis in tumor initiation and progression. These studies, combined with data that link alterations in the levels of circulating IGFs with cancer risk and prognosis, have focused on the IGF-1 receptor (IGF-1R) as a therapeutic target for patients with cancer. As a consequence, most therapeutic strategies have been designed to specifically inhibit IGF-1R but have for the most part ignored the insulin receptor (IR), based on concerns that targeting IR would lead to unacceptable toxicity both because of its role in physiologic metabolism and because we frequently try to oversimplify biologic complexity whenever we are urged to find practical, friendly solutions for clinical practice. Although this is an understandable and necessary starting point in the complex and long-lasting processes that leads to translational biology, the crude reality of the results obtained from phase I and II studies suggest a need for researchers to be humble and go back to the drawing board. Cancer research has substantially neglected the role of IR, and it remains unclear whether and to what extent avoiding the inhibition of IR has compromised the efficacy of anti-IGF-1R therapy. Clarifying its role might also help us take advantage of older drugs that could offer new perspectives in cancer care. PMID:24451803

  10. AT1 Receptor Mediated Augmentation of Intrarenal Angiotensinogen in Angiotensin II-Dependent Hypertension

    PubMed Central

    Kobori, Hiroyuki; Prieto-Carrasquero, Minolfa C.; Ozawa, Yuri; Navar, L. Gabriel

    2009-01-01

    Angiotensin (Ang) II-infused hypertensive rats exhibit increases in renal angiotensinogen mRNA and protein, as well as urinary angiotensinogen excretion in association with increased intrarenal Ang II content. The present study was performed to determine if the augmentation of intrarenal angiotensinogen requires activation of Ang II type 1 (AT1) receptors. Male Sprague-Dawley rats (200 to 220 g) were divided into 3 groups: sham surgery (n=10), subcutaneous infusion of Ang II (80 ng/min, n=11), and Ang II infusion plus AT1 blocker (ARB), olmesartan (5 mg/d, n=12). Ang II infusion progressively increased systolic blood pressure (SBP) compared with sham (178±8 mm Hg versus119±4 at day 11). ARB treatment prevented hypertension (113±6 at day 11). Twenty-four-hour urine collections were taken at day 12, and plasma and tissue samples were harvested at day 13. The Ang II+ARB group had a significant increase in plasma Ang II compared with Ang II and sham groups (365±46 fmol/mL versus 76±9 and 45±14, respectively). Nevertheless, ARB treatment markedly limited the enhancement of kidney Ang II by Ang II infusion (65±17 fmol/g in sham, 606±147 in Ang II group, and 288±28 in Ang II+ARB group). Ang II infusion significantly increased kidney angiotensinogen compared with sham (1.69±0.21 densitometric units versus 1.00±0.17). This change was reflected by increased angiotensinogen immunostaining in proximal tubules. ARB treatment prevented this increase (1.14±0.12). Urinary angiotensinogen excretion rates were enhanced 4.7× in Ang II group (4.67±0.41 densitometric units versus 1.00±0.21) but ARB treatment prevented the augmentation of urinary angiotensinogen (0.96±0.23). These data demonstrate that augmentation of intrarenal angiotensinogen in Ang II-infused rats is AT1-dependent and provide further evidence that urinary angiotensinogen is closely linked to intrarenal Ang II in Ang II-dependent hypertension. PMID:15037565

  11. Role of the transient receptor potential vanilloid type 1 receptor and stretch-activated ion channels in nitric oxide release from endothelial cells of the aorta and heart in rats.

    PubMed

    Torres-Narváez, Juan Carlos; Mondragón, Leonardo Del Valle; Varela López, Elvira; Pérez-Torres, Israel; Díaz Juárez, Julieta Anabell; Suárez, Jorge; Hernández, Gustavo Pastelín

    2012-09-01

    Shear stress stimulates nitric oxide (NO) release in endothelial cells. Stretch-activated ion channels (SACs) and the transient receptor potential vanilloid type 1 (TRPV1) receptor respond to mechanical stimulus and are permeable to Na(+), Ca(2+) and K(+). The influence of SACs and the TRPV1 receptor on NO release on the heart and on the vascular reactivity of the thoracic aorta (TA) was studied. Experiments were performed in isolated perfused heart, cultured endothelial cells and TA rings from Wistar rats. Capsaicin (10 μM, 30 μM) was used as a NO release stimulator, capsazepine (6 μM, 10 μM) was used as a capsaicin antagonist and gadolinium (3 μM, 5 μM) was used as an inhibitor of SACs. NO was measured by the Kelm and Tenorio methods. Left ventricular pressure was recorded and coronary vascular resistance was calculated. Capsaicin increased NO release in the heart by 58% (395±8 pmol/mL to 627±23 pmol/mL). Capsazepine and gadolinium inhibited NO release by 74% and 82%, respectively. This tendency was similar in all experimental models. Capsaicin attenuated the effects of norepinephrine (10 M to 7 M) on TA and had no effect in the presence of N (ω)-nitro-L-arginine methyl ester. Therefore, the authors conclude that SACs and the TRPV1 receptor are both present in the coronary endothelium and that both participate in Ca(2+)-dependent NO release. PMID:23620694

  12. Role of the transient receptor potential vanilloid type 1 receptor and stretch-activated ion channels in nitric oxide release from endothelial cells of the aorta and heart in rats

    PubMed Central

    Torres-Narváez, Juan Carlos; Mondragón, Leonardo del Valle; Varela López, Elvira; Pérez-Torres, Israel; Díaz Juárez, Julieta Anabell; Suárez, Jorge; Hernández, Gustavo Pastelín

    2012-01-01

    Shear stress stimulates nitric oxide (NO) release in endothelial cells. Stretch-activated ion channels (SACs) and the transient receptor potential vanilloid type 1 (TRPV1) receptor respond to mechanical stimulus and are permeable to Na+, Ca2+ and K+. The influence of SACs and the TRPV1 receptor on NO release on the heart and on the vascular reactivity of the thoracic aorta (TA) was studied. Experiments were performed in isolated perfused heart, cultured endothelial cells and TA rings from Wistar rats. Capsaicin (10 μM, 30 μM) was used as a NO release stimulator, capsazepine (6 μM, 10 μM) was used as a capsaicin antagonist and gadolinium (3 μM, 5 μM) was used as an inhibitor of SACs. NO was measured by the Kelm and Tenorio methods. Left ventricular pressure was recorded and coronary vascular resistance was calculated. Capsaicin increased NO release in the heart by 58% (395±8 pmol/mL to 627±23 pmol/mL). Capsazepine and gadolinium inhibited NO release by 74% and 82%, respectively. This tendency was similar in all experimental models. Capsaicin attenuated the effects of norepinephrine (10 M to 7 M) on TA and had no effect in the presence of Nω-nitro-L-arginine methyl ester. Therefore, the authors conclude that SACs and the TRPV1 receptor are both present in the coronary endothelium and that both participate in Ca2+-dependent NO release. PMID:23620694

  13. Early decrease of type 1 cannabinoid receptor binding and phosphodiesterase 10A activity in vivo in R6/2 Huntington mice.

    PubMed

    Ooms, Maarten; Rietjens, Roma; Rangarajan, Janaki Raman; Vunckx, Kathleen; Valdeolivas, Sara; Maes, Frederik; Himmelreich, Uwe; Fernandez-Ruiz, Javier; Bormans, Guy; Van Laere, Koen; Casteels, Cindy

    2014-12-01

    Several lines of evidence imply early alterations in endocannabinoid and phosphodiesterase 10A (PDE10A) signaling in Huntington disease (HD). Using [(18)F]MK-9470 and [(18)F]JNJ42259152 small-animal positron emission tomography (PET), we investigated for the first time cerebral changes in type 1 cannabinoid (CB1) receptor binding and PDE10A levels in vivo in presymptomatic, early symptomatic, and late symptomatic HD (R6/2) mice, in relation to glucose metabolism ([(18)F]FDG PET), brain morphology (magnetic resonance imaging) and motor function. Ten R6/2 and 16 wild-type (WT) mice were investigated at 3 different time points between the age of 4 and 13 weeks. Parametric CB1 receptor and PDE10A images were anatomically standardized to Paxinos space and analyzed voxelwise. Volumetric microMRI imaging was performed to assess HD pathology. In R6/2 mice, CB1 receptor binding was decreased in comparison with WT in a cluster comprising the bilateral caudate-putamen, globus pallidus, and thalamic nucleus at week 5 (-8.1% ± 2.6%, p = 1.7 × 10(-5)). Longitudinal follow-up showed further progressive decline compared with controls in a cluster comprising the bilateral hippocampus, caudate-putamen, globus pallidus, superior colliculus, thalamic nucleus, and cerebellum (late vs. presymptomatic age: -13.7% ± 3.1% for R6/2 and +1.5% ± 4.0% for WT, p = 1.9 × 10(-5)). In R6/2 mice, PDE10A binding potential also decreased over time to reach significance at early and late symptomatic HD (late vs. presymptomatic age: -79.1% ± 1.9% for R6/2 and +2.1% ± 2.7% for WT, p = 1.5 × 10(-4)). The observed changes in CB1 receptor and PDE10A binding were correlated to anomalies exhibited by R6/2 animals in motor function, whereas no correlation was found with magnetic resonance imaging-based striatal volume. Our findings point to early regional dysfunctions in endocannabinoid and PDE10A signaling, involving the caudate-putamen and lateral globus pallidus, which may play a role

  14. Insulin-like growth factor-II (IGF II) receptor from rat brain is of lower apparent molecular weight than the IGF II receptor from rat liver

    SciTech Connect

    McElduff, A.; Poronnik, P.; Baxter, R.C.

    1987-10-01

    The binding subunits of the insulin and insulin-like growth factor-I (IGF I) receptors from rat brain are of lower molecular weight than the corresponding receptor in rat liver, possibly due to variations in sialic acid content. We have compared the IGF II receptor from rat brain and rat liver. The brain receptor is of smaller apparent mol wt (about 10 K) on sodium dodecyl sulfate polyacrylamide gel electrophoresis. This size difference is independent of ligand binding as it persists in iodinated and specifically immunoprecipitated receptors. From studies of wheat germ agglutinin binding and the effect of neuraminidase on receptor mobility, we conclude that this difference is not simply due to variations in sialic acid content. Treatment with endoglycosidase F results in reduction in the molecular size of both liver and brain receptors and after this treatment the aglycoreceptors are of similar size. We conclude that in rat brain tissue the IGF II receptor like the binding subunits of the insulin and IGF I receptors is of lower molecular size than the corresponding receptors in rat liver. This difference is due to differences in N-linked glycosylation.

  15. Genetic risk for co-occurrence of type 1 diabetes and celiac disease is modified by HLA-C and killer immunoglobulin-like receptors.

    PubMed

    Smigoc Schweiger, D; Mendez, A; Kunilo Jamnik, S; Bratanic, N; Bratina, N; Battelino, T; Brecelj, J; Vidan-Jeras, B

    2014-11-01

    The prevalence of celiac disease (CD) in patients with type 1 diabetes (T1D) has been reported to be 5-7 times higher than in the general population. Risk factors for co-occurrence of both diseases have not been entirely established. The aim of our study was to analyze possible impact of human leukocyte antigen (HLA) class I and killer cell immunoglobulin-like receptors (KIRs) on the co-occurrence of T1D and CD. We analyzed 67 patients with T1D, 68 patients with CD, 69 patients with both diseases (T1D+CD) and 130 controls. Statistical analysis was based on two tailed Fisher exact test with corrections for multiple testing. After stratification by DR3-DQ2, an association of HLA class I part of the COX haplotype (A1-B8-Cw7-DR3-DQ2) was not observed with each of the studied diseases separately, but it could be shown in case of the co-occurrence of T1D and CD. Only in the group of patients with coexisting diseases, the presence of HLA-C*07 (P = 8.65×10(-3) ) and HLA-B*08 (P = 0.03) but not HLA-A*01 increased the succeptibility. Our current data indicated that C*07, contributing C1 ligand (Pc  = 3.67×10(-5) ) rather than B*08, that possesses no KIR ligand, could have an impact on the innate immunity rout of this susceptibility. The significant combination of C1-KIR2DL3 (Pc  = 1.97×10(-4) ) observed in patients with coexisting diseases supports this hypotesis. Interestingly, no association was observed when C1 in combination with its stronger inhibitory receptor KIR2DL2 was investigated. Predominantly, weak inhibition in patients with coexisting T1D and CD could lead to a natural killer cell response, making them vulnerable for developing more than one autoimmune disease. PMID:25329633

  16. Autoradiographic localization of angiotensin II receptors in rat brain

    SciTech Connect

    Mendelsohn, F.A.O.; Quirion, R.; Saavedra, J.M.; Aguilera, G.; Catt, K.J.

    1984-03-01

    The /sup 125/I-labeled agonist analog (1-sarcosine)-angiotensin II ((Sar/sup 1/)AII) bound with high specificity and affinity (K/sub a/ = 2 x 10/sup 9/ M/sup -1/) to a single class of receptor sites in rat brain. This ligand was used to analyze the distribution of AII receptors in rat brain by in vitro autoradiography followed by computerized densitometry and color coding. A very high density of AII receptors was found in the subfornical organ, paraventricular and periventricular nuclei of the hypothalamus, nucleus of the tractus solitarius, and area postrema. A high concentration of receptors was found in the suprachiasmatic nucleus of the hypothalamus, lateral olfactory tracts, nuclei of the accessory and lateral olfactory tracts, triangular septal nucleus, subthalamic nucleus, locus coeruleus, and inferior olivary nuclei. Moderate receptor concentrations were found in the organum vasculosum of the lamina terminalis, median preoptic nucleus, medial habenular nucleus, lateral septum, ventroposterior thalamic nucleus, median eminence, medial geniculate nucleus, superior colliculus, subiculum, pre- and parasubiculum, and spinal trigeminal tract. Low concentrations of sites were seen in caudate-putamen, nucleus accumbens, amygdala, and gray matter of the spinal cord. These studies have demonstrated that AII receptors are distributed in a highly characteristic anatomical pattern in the brain. The high concentrations of AII receptors at numerous physiologically relevant sites are consistent with the emerging evidence for multiple roles of AII as a neuropeptide in the central nervous system. 75 references, 2 figures.

  17. Autoradiographic localization of angiotensin II receptors in rat brain.

    PubMed Central

    Mendelsohn, F A; Quirion, R; Saavedra, J M; Aguilera, G; Catt, K J

    1984-01-01

    The 125I-labeled agonist analog [1-sarcosine]-angiotensin II ( [Sar1]AII) bound with high specificity and affinity (Ka = 2 X 10(9) M-1) to a single class of receptor sites in rat brain. This ligand was used to analyze the distribution of AII receptors in rat brain by in vitro autoradiography followed by computerized densitometry and color coding. A very high density of AII receptors was found in the subfornical organ, paraventricular and periventricular nuclei of the hypothalamus, nucleus of the tractus solitarius, and area postrema. A high concentration of receptors was found in the suprachiasmatic nucleus of the hypothalamus, lateral olfactory tracts, nuclei of the accessory and lateral olfactory tracts, triangular septal nucleus, subthalamic nucleus, locus coeruleus, and inferior olivary nuclei. Moderate receptor concentrations were found in the organum vasculosum of the lamina terminalis, median preoptic nucleus, medial habenular nucleus, lateral septum, ventroposterior thalamic nucleus, median eminence, medial geniculate nucleus, superior colliculus, subiculum, pre- and parasubiculum, and spinal trigeminal tract. Low concentrations of sites were seen in caudate-putamen, nucleus accumbens, amygdala, and gray matter of the spinal cord. These studies have demonstrated that AII receptors are distributed in a highly characteristic anatomical pattern in the brain. The high concentrations of AII receptors at numerous physiologically relevant sites are consistent with the emerging evidence for multiple roles of AII as a neuropeptide in the central nervous system. Images PMID:6324205

  18. Lateral diffusion of inositol 1,4,5-trisphosphate receptor type 1 is regulated by actin filaments and 4.1N in neuronal dendrites.

    PubMed

    Fukatsu, Kazumi; Bannai, Hiroko; Zhang, Songbai; Nakamura, Hideki; Inoue, Takafumi; Mikoshiba, Katsuhiko

    2004-11-19

    Inositol 1,4,5-trisphosphate receptor type1 (IP3R1) plays an important role in neuronal functions; however, the lateral diffusion of IP3R1 on the endoplasmic reticulum membrane and its regulation in the living neurons remain unknown. We expressed green fluorescent protein-tagged IP3R1 in cultured rat hippocampal neurons and observed the lateral diffusion by the fluorescence recovery after photobleaching technique. IP3R1 showed lateral diffusion with an effective diffusion constant of approximately 0.3 microm2/s. Depletion of actin filaments increased the diffusion constant of IP3R1, suggesting that the diffusion of IP3R1 is regulated negatively through actin filaments. We also found that protein 4.1N, which binds to IP3R1 and contains an actin-spectrin-binding region, was responsible for this actin regulation of the IP3R1 diffusion constant. Overexpression of dominant-negative 4.1N and blockade of 4.1N binding to IP3R1 increased the IP3R1 diffusion constant. The diffusion of IP3R type 3 (IP3R3), one of the isoforms of IP3Rs lacking the binding ability to 4.1N, was not dependent on actin filaments but became dependent on actin filaments after the addition of a 4.1N-binding sequence. These data suggest that 4.1N serves as a linker protein between IP3R1 and actin filaments. This actin filament-dependent regulation of IP3R1 diffusion may be important for the spatiotemporal regulation of intracellular Ca2+ signaling. PMID:15364918

  19. Multiple splice variants of the pituitary adenylate cyclase-activating polypeptide type 1 receptor detected by RT-PCR in single rat pituitary cells.

    PubMed

    Bresson-Bépoldin, L; Jacquot, M C; Schlegel, W; Rawlings, S R

    1998-10-01

    Alternative splicing of the rat type 1 pituitary adenylate cyclase-activating polypeptide (PACAP) receptor (PVR1) produces variants that couple either to both adenylyl cyclase (AC) and phospholipase C (PLC) (PVR1 short, PVR1 hop, PVR1 hiphop), or to AC alone (PVR1 hip). We have previously shown that populations of clonal alphaT3-1 gonadotrophs express PVR1 hop and PVR1 short mRNAs, whereas clonal GH4C1 somatotrophs do not. Here we have used the single cell RT-PCR technique to investigate whether normal rat gonadotrophs and somatotrophs express PVR1 mRNA, whether a single cell co-expresses multiple splice variant forms, and whether differential PVR1 mRNA expression correlates with differences in PACAP-stimulated Ca2+ signalling. We found that individual rat gonadotrophs expressed mRNA either for PVR1 hop, for PVR1 short, or co-expressed the two forms. Although we found no differences between the splice variant(s) expressed and the characteristics of PACAP-stimulated Ca2+ responses, the expression of PVR1 mRNA is consistent with the known PACAP stimulation of the PLC system in gonadotrophs. Individual rat somatotrophs also expressed PVR1 hop or PVR1 short (but not PVR1 hip) mRNAs although these forms were never co-expressed. The expression of PVR1 mRNA in somatotrophs can explain in part the activation by PACAP of the AC system in such cells. In conclusion, the single cell RT-PCR technique was used to demonstrate expression of multiple PVR1 splice variants in single identified pituitary cells. These findings open up important questions on the role of alternative splicing in cell biology. PMID:9801454

  20. The chromosome 16q region associated with ankylosing spondylitis includes the candidate gene tumour necrosis factor receptor type 1-associated death domain (TRADD)

    PubMed Central

    Pointon, Jennifer J; Harvey, David; Karaderi, Tugce; Appleton, Louise H; Farrar, Claire; Stone, Millicent A; Sturrock, Roger D; Reveille, John D; Weisman, Michael H; Ward, Michael M; Brown, Matthew A; Wordsworth, B Paul

    2010-01-01

    Objective To replicate and refine the reported association of ankylosing spondylitis (AS) with two non-synonymous single nucleotide polymorphisms (nsSNPs) on chromosome 16q22.1. Methods Firstly, 730 independent UK patients with AS were genotyped for rs9939768 and rs6979 and allele frequencies were compared with 2879 previously typed historic disease controls. Secondly, the two data sets were combined in meta-analyses. Finally, 5 tagging SNPs, located between rs9939768 and rs6979, were analysed in 1604 cases and 1020 controls. Results The association of rs6979 with AS was replicated, p=0.03, OR=1.14 (95% CI 1.01 to 1.28), and a trend for association with rs9939768 detected, p=0.06, OR=1.25 (95% CI 0.99 to 1.57). Meta-analyses revealed association of both SNPs with AS, p=0.0008, OR=1.31 (95% CI 1.12 to 1.54) and p=0.0009, OR=1.15 (95% CI 1.06 to 1.23) for rs9939768 and rs6979, respectively. New associations with rs9033 and rs868213 (p=0.00002, OR=1.23 (95% CI 1.12 to 1.36) and p=0.00002 OR=1.45 (95% CI 1.22 to 1.72), respectively, were identified. Conclusions The region on chromosome 16 that has been replicated in the present work is interesting as the highly plausible candidate gene, tumour necrosis factor receptor type 1 (TNFR1)-associated death domain (TRADD), is located between rs9033 and rs868213. It will require additional work to identify the primary genetic association(s) with AS. PMID:19854717

  1. Osteoprotegerin, Soluble Receptor Activator of Nuclear Factor- κ B Ligand, and Subclinical Atherosclerosis in Children and Adolescents with Type 1 Diabetes Mellitus.

    PubMed

    Lambrinoudaki, Irene; Tsouvalas, Emmanouil; Vakaki, Marina; Kaparos, George; Stamatelopoulos, Kimon; Augoulea, Areti; Pliatsika, Paraskevi; Alexandrou, Andreas; Creatsa, Maria; Karavanaki, Kyriaki

    2013-01-01

    Aims. To evaluate carotid intima-media thickness (cIMT) and biomarkers of the osteoprotegerin/receptor activator of nuclear factor- κ B ligand (OPG/RANKL) system in type 1 diabetes (T1DM) children and adolescents and controls. Subjects and Methods. Fifty six T1DM patients (mean ± SD age: 12.0 ± 2.7 years, diabetes duration: 5.42 ± 2.87 years and HbA1c: 8.0 ± 1.5%) and 28 healthy matched controls, were studied with anthropometric and laboratory measurements, including serum OPG, soluble RANKL (sRANKL) and cIMT. Results. Anthropometric, laboratory, and cIMT measurements were similar between T1DM youngsters and controls. However patients with longer diabetes duration (>/7.0 years) had indicatively higher cIMT (cIMT = 0.49 vs 0.44 mm, P 0.072) and triglyceride levels than the rest of the patients (93.7 vs 64.6 mg/dl, P 0.025). Both in the total study population (β 0.418, P 0.027) and among T1DM patients separately (β 0.604, P 0.013), BMI was the only factor associated with cIMT. BMI was further associated with OPG in both groups (β -0.335, P 0.003 and β -0.356, P 0.008 respectively), while sRANKL levels were not associated with any factor. Conclusions. BMI was the strongest independent predictor of cIMT among the whole population, and especially in diabetics, suggesting a possible synergistic effect of diabetes and adiposity on atherosclerotic burden. BMI was overall strongly associated with circulating OPG, but the causes of this association remain unclear. PMID:24288529

  2. INTRACEREBROVENTRICULAR LOSARTAN INFUSION MODULATES ANGIOTENSIN TYPE 1 RECEPTOR EXPRESSION IN THE SUBFORNICAL ORGAN AND DRINKING BEHAVIOUR IN BILE DUCT LIGATED RATS

    PubMed Central

    Walch, Joseph D; Carreño, Flávia Regina; Cunningham, J. Thomas

    2013-01-01

    Bile duct ligation (BDL) causes congestive liver failure that initiates hemodynamic changes including peripheral vasodilation and generalized edema. Peripheral vasodilation is hypothesized to then activate compensatory mechanisms including increased drinking behavior and neurohumoral activation. This study tested the hypothesis that changes in the expression of AT1R mRNA and protein in the lamina terminalis is associated with BDL induced hypoosmolality in the rat. All rats received either BDL or sham ligation surgery. The rats were housed in metabolic chambers for measurement of fluid and food intake and urine output. Angiotensin type 1 receptor (AT1R) expression in the lamina terminalis was assessed by western blot and quantitative real-time PCR (RT-qPCR). Average baseline water intake significantly increased in BDL rats compared to sham and upregulation of AT1R protein and AT1aR mRNA were observed in the subfornical organ (SFO) of BDL rats. Separate groups of BDL and sham ligated rats were instrumented with minipumps filled with either losartan (2.0 µg/µl) or 0.9% saline for chronic intracerebroventricular (ICV) or subcutaneous (SC) chronic infusion. Chronic ICV losartan infusion attenuated the increased drinking behavior and prevented the increased abundance of AT1R protein in the SFO in BDL rats. Chronic SC did not affect water intake or AT1R abundance in the SFO. The data presented here indicate a possible role of increased central AT1R expression in the regulation of drinking behavior during congestive cirrhosis. PMID:23243146

  3. Overexpression of ryanodine receptor type 1 enhances mitochondrial fragmentation and Ca2+-induced ATP production in cardiac H9c2 myoblasts

    PubMed Central

    O-Uchi, Jin; Jhun, Bong Sook; Hurst, Stephen; Bisetto, Sara; Gross, Polina; Chen, Ming; Kettlewell, Sarah; Park, Jongsun; Oyamada, Hideto; Smith, Godfrey L.; Murayama, Takashi

    2013-01-01

    Ca+ influx to mitochondria is an important trigger for both mitochondrial dynamics and ATP generation in various cell types, including cardiac cells. Mitochondrial Ca2+ influx is mainly mediated by the mitochondrial Ca2+ uniporter (MCU). Growing evidence also indicates that mitochondrial Ca2+ influx mechanisms are regulated not solely by MCU but also by multiple channels/transporters. We have previously reported that skeletal muscle-type ryanodine receptor (RyR) type 1 (RyR1), which expressed at the mitochondrial inner membrane, serves as an additional Ca2+ uptake pathway in cardiomyocytes. However, it is still unclear which mitochondrial Ca2+ influx mechanism is the dominant regulator of mitochondrial morphology/dynamics and energetics in cardiomyocytes. To investigate the role of mitochondrial RyR1 in the regulation of mitochondrial morphology/function in cardiac cells, RyR1 was transiently or stably overexpressed in cardiac H9c2 myoblasts. We found that overexpressed RyR1 was partially localized in mitochondria as observed using both immunoblots of mitochondrial fractionation and confocal microscopy, whereas RyR2, the main RyR isoform in the cardiac sarcoplasmic reticulum, did not show any expression at mitochondria. Interestingly, overexpression of RyR1 but not MCU or RyR2 resulted in mitochondrial fragmentation. These fragmented mitochondria showed bigger and sustained mitochondrial Ca2+ transients compared with basal tubular mitochondria. In addition, RyR1-overexpressing cells had a higher mitochondrial ATP concentration under basal conditions and showed more ATP production in response to cytosolic Ca2+ elevation compared with nontransfected cells as observed by a matrix-targeted ATP biosensor. These results indicate that RyR1 possesses a mitochondrial targeting/retention signal and modulates mitochondrial morphology and Ca2+-induced ATP production in cardiac H9c2 myoblasts. PMID:24124188

  4. Myeloid Cell Prostaglandin E2 Receptor EP4 Modulates Cytokine Production but Not Atherogenesis in a Mouse Model of Type 1 Diabetes

    PubMed Central

    Vallerie, Sara N.; Kramer, Farah; Barnhart, Shelley; Kanter, Jenny E.; Breyer, Richard M.; Andreasson, Katrin I.; Bornfeldt, Karin E.

    2016-01-01

    Type 1 diabetes mellitus (T1DM) is associated with cardiovascular complications induced by atherosclerosis. Prostaglandin E2 (PGE2) is often raised in states of inflammation, including diabetes, and regulates inflammatory processes. In myeloid cells, a key cell type in atherosclerosis, PGE2 acts predominately through its Prostaglandin E Receptor 4 (EP4; Ptger4) to modulate inflammation. The effect of PGE2-mediated EP4 signaling specifically in myeloid cells on atherosclerosis in the presence and absence of diabetes is unknown. Because diabetes promotes atherosclerosis through increased arterial myeloid cell accumulation, we generated a myeloid cell-targeted EP4-deficient mouse model (EP4M-/-) of T1DM-accelerated atherogenesis to investigate the relationship between myeloid cell EP4, inflammatory phenotypes of myeloid cells, and atherogenesis. Diabetic mice exhibited elevated plasma PGE metabolite levels and elevated Ptger4 mRNA in macrophages, as compared with non-diabetic littermates. PGE2 increased Il6, Il1b, Il23 and Ccr7 mRNA while reducing Tnfa mRNA through EP4 in isolated myeloid cells. Consistently, the stimulatory effect of diabetes on peritoneal macrophage Il6 was mediated by PGE2-EP4, while PGE2-EP4 suppressed the effect of diabetes on Tnfa in these cells. In addition, diabetes exerted effects independent of myeloid cell EP4, including a reduction in macrophage Ccr7 levels and increased early atherogenesis characterized by relative lesional macrophage accumulation. These studies suggest that this mouse model of T1DM is associated with increased myeloid cell PGE2-EP4 signaling, which is required for the stimulatory effect of diabetes on IL-6, markedly blunts the effect of diabetes on TNF-α and does not modulate diabetes-accelerated atherogenesis. PMID:27351842

  5. A small difference in the molecular structure of angiotensin II receptor blockers induces AT1 receptor-dependent and -independent beneficial effects

    PubMed Central

    Fujino, Masahiro; Miura, Shin-ichiro; Kiya, Yoshihiro; Tominaga, Yukio; Matsuo, Yoshino; Karnik, Sadashiva S; Saku, Keijiro

    2013-01-01

    Angiotensin II (Ang II) type 1 (AT1) receptor blockers (ARBs) induce multiple pharmacological beneficial effects, but not all ARBs have the same effects and the molecular mechanisms underlying their actions are not certain. In this study, irbesartan and losartan were examined because of their different molecular structures (irbesartan has a cyclopentyl group whereas losartan has a chloride group). We analyzed the binding affinity and production of inositol phosphate (IP), monocyte chemoattractant protein-1 (MCP-1) and adiponectin. Compared with losartan, irbesartan showed a significantly higher binding affinity and slower dissociation rate from the AT1 receptor and a significantly higher degree of inverse agonism and insurmountability toward IP production. These effects of irbesartan were not seen with the AT1-Y113A mutant receptor. On the basis of the molecular modeling of the ARBs–AT1 receptor complex and a mutagenesis study, the phenyl group at Tyr113 in the AT1 receptor and the cyclopentyl group of irbesartan may form a hydrophobic interaction that is stronger than the losartan–AT1 receptor interaction. Interestingly, irbesartan inhibited MCP-1 production more strongly than losartan. This effect was mediated by the inhibition of nuclear factor-kappa B activation that was independent of the AT1 receptor in the human coronary endothelial cells. In addition, irbesartan, but not losartan, induced significant adiponectin production that was mediated by peroxisome proliferator-activated receptor-γ activation in 3T3-L1 adipocytes, and this effect was not mediated by the AT1 receptor. In conclusion, irbesartan induced greater beneficial effects than losartan due to small differences between their molecular structures, and these differential effects were both dependent on and independent of the AT1 receptor. PMID:20668453

  6. The transforming growth factor beta type II receptor can replace the activin type II receptor in inducing mesoderm.

    PubMed Central

    Bhushan, A; Lin, H Y; Lodish, H F; Kintner, C R

    1994-01-01

    The type II receptors for the polypeptide growth factors transforming growth factor beta (TGF-beta) and activin belong to a new family of predicted serine/threonine protein kinases. In Xenopus embryos, the biological effects of activin and TGF-beta 1 are strikingly different; activin induces a full range of mesodermal cell types in the animal cap assay, while TGF-beta 1 has no effects, presumably because of the lack of functional TGF-beta receptors. In order to assess the biological activities of exogenously added TGF-beta 1, RNA encoding the TGF-beta type II receptor was introduced into Xenopus embryos. In animal caps from these embryos, TGF-beta 1 and activin show similar potencies for induction of mesoderm-specific mRNAs, and both elicit the same types of mesodermal tissues. In addition, the response of animal caps to TGF-beta 1, as well as to activin, is blocked by a dominant inhibitory ras mutant, p21(Asn-17)Ha-ras. These results indicate that the activin and TGF-beta type II receptors can couple to similar signalling pathways and that the biological specificities of these growth factors lie in their different ligand-binding domains and in different competences of the responding cells. Images PMID:8196664

  7. Type 1 diabetes in Japan.

    PubMed

    Kawasaki, E; Matsuura, N; Eguchi, K

    2006-05-01

    Type 1 diabetes is a multifactorial disease which results from a T-cell-mediated autoimmune destruction of the pancreatic beta cells in genetically predisposed individuals. The risk for individuals of developing type 1 diabetes varies remarkably according to country of residence and race. Japan has one of the lowest incidence rates of type 1 diabetes in the world, and recognises at least three subtypes of the condition: acute-onset ('classical'), slow-onset, and fulminant type 1 diabetes. The incidence rate of type 1 diabetes in children aged 0-14 years in Japan increased over the period from 1973-1992, but remained constant over the last decade, averaging 2.37 cases per 100,000 persons per year; the incidence does not appear to have increased in older age groups. Although there are few reports regarding the incidence and prevalence of type 1 diabetes in adult-onset patients, it appears that the prevalence of type 1 diabetes in adults is more than twice that in childhood-onset patients and that two-thirds of them have a slow-onset form of type 1 diabetes. Differences and similarities in the association of MHC and non-MHC genes with type 1 diabetes are observed in Japan and in countries with Caucasoid populations. Highly susceptible class II HLA haplotypes identified in patients of Caucasoid origin are rarely seen in Japanese patients, whereas protective haplotypes are universal. Non-MHC genes associated with susceptibility to type 1 diabetes in both Japanese and Caucasoid patients include polymorphisms in the insulin gene, the cytotoxic T-lymphocyte antigen 4 (CTLA4) gene, the interleukin-18 (IL18) gene and the major histocompatibility complex class I chain-related gene A (MICA) gene. Fulminant type 1 diabetes is a unique subtype of type 1 diabetes that accounts for about 20% of acute-onset type 1 diabetes, and is seen mainly in adults. The challenge for the future is to investigate the underlying pathogenesis of beta cell destruction, including the genetic or

  8. Role of agonistic autoantibodies against type-1 angiotensin II receptor in the pathogenesis of retinopathy in preeclampsia

    PubMed Central

    Liu, Fang; Wang, Yuxian; Wang, Xiaofang; Zheng, Yanqian; Jin, Zhu; Zhi, Jianming

    2016-01-01

    To investigate the mechanism underlying AT1-AA-induced retinopathy in severe preeclampsia by measuring the positive rate and titer of AT1-AA in plasma from women with severe preeclampsia and normal pregnant women to see whether AT1-AA titer was correlated with the grade of retinopathy. A preeclampsia rat model was also established by intravenous injection of AT1-AA extracted from the plasma of patient suffering from severe preeclampsia. The results showed that the plasma titer and positive rate of AT1-AA were significantly higher in women with severe preeclampsia than normal pregnant women. The antibody titer in cases of severe preeclampsia was associated with the grade of retinopathy, and positively correlated with the level of TNF-α and VEGF. The animal experiment results showed that the modeled rats presented symptoms very similar to symptoms of human preeclampsia, including retinopathy. Ocular fundus examination showed retinal microvascular abnormalities, hemorrhaging and leakage in the severe preeclampsia. Morphological changes included edema, thickening of the INL and ONL, and pigment atrophy. TNF-α and VEGF levels were increased in the vitreous humor and retina of the model rats. Our studies results suggest that abnormal expression of AT1-AA could induce damage to retinal capillary endothelial cells and increase vascular permeability, resulting in retinopathy. PMID:27381670

  9. Role of agonistic autoantibodies against type-1 angiotensin II receptor in the pathogenesis of retinopathy in preeclampsia.

    PubMed

    Liu, Fang; Wang, Yuxian; Wang, Xiaofang; Zheng, Yanqian; Jin, Zhu; Zhi, Jianming

    2016-01-01

    To investigate the mechanism underlying AT1-AA-induced retinopathy in severe preeclampsia by measuring the positive rate and titer of AT1-AA in plasma from women with severe preeclampsia and normal pregnant women to see whether AT1-AA titer was correlated with the grade of retinopathy. A preeclampsia rat model was also established by intravenous injection of AT1-AA extracted from the plasma of patient suffering from severe preeclampsia. The results showed that the plasma titer and positive rate of AT1-AA were significantly higher in women with severe preeclampsia than normal pregnant women. The antibody titer in cases of severe preeclampsia was associated with the grade of retinopathy, and positively correlated with the level of TNF-α and VEGF. The animal experiment results showed that the modeled rats presented symptoms very similar to symptoms of human preeclampsia, including retinopathy. Ocular fundus examination showed retinal microvascular abnormalities, hemorrhaging and leakage in the severe preeclampsia. Morphological changes included edema, thickening of the INL and ONL, and pigment atrophy. TNF-α and VEGF levels were increased in the vitreous humor and retina of the model rats. Our studies results suggest that abnormal expression of AT1-AA could induce damage to retinal capillary endothelial cells and increase vascular permeability, resulting in retinopathy. PMID:27381670

  10. Distinct angiotensin II receptor in primary cultures of glial cells from rat brain

    SciTech Connect

    Raizada, M.K.; Phillips, M.I.; Crews, F.T.; Sumners, C.

    1987-07-01

    Angiotensin II (Ang-II) has profound effects on the brain. Receptors for Ang-II have been demonstrated on neurons, but no relationship between glial cells and Agn-II has been established. Glial cells (from the hypothalamus and brain stem of 1-day-old rat brains) in primary culture have been used to demonstrate the presence of specific Ang-II receptors. Binding of /sup 125/I-Ang-II to glial cultures was rapid, reversible, saturable, and specific for Ang-II. The rank order of potency of /sup 125/I-Ang-II binding was determined. Scatchard analysis revealed a homogeneous population of high-affinity binding sites with a B/sub max/ of 110 fmol/mg of protein. Light-microscopic autoradiography of /sup 125/I-Ang-II binding supported the kinetic data, documenting specific Ang-II receptors on the glial cells. Ang-II stimulated a dose-dependent hydrolysis of phosphatidylinositols in glial cells, an effect mediated by Ang-II receptors. However, Ang-II failed to influence (/sup 3/H) norepinephrine uptake, and catecholamines failed to regulate Ang-II receptors, effects that occur in neurons. These observations demonstrate the presence of specific Ang-II receptors on the glial cells in primary cultures derived from normotensive rat brain. The receptors are kinetically similar to, but functionally distinct from, the neuronal Ang-II receptors.

  11. Diabetes Type 1

    MedlinePlus

    ... blood sugar, levels are too high. With type 1 diabetes, your pancreas does not make insulin. Insulin ... eyes, kidneys, nerves, and gums and teeth. Type 1 diabetes happens most often in children and young ...

  12. Angiotensin II receptor subtypes in rat renal preglomerular vessels.

    PubMed

    De León, H; Garcia, R

    1992-01-01

    A simple technique to isolate rat renal preglomerular vessels is described. Kidneys were pressed against a 0.3 mm stainless steel grid. The whole vascular tree, including the interlobar, arcuate, and interlobular arteries, as well as the afferent arterioles, remained on the grid surface from where they were recovered. Extensive washing yielded a highly pure preparation of renal microvessels. Radioligand binding experiments were performed to characterize 125I-[Sar1,Ile8]-ANG II binding sites in preglomerular microvessel membranes. Equilibrium saturation binding experiments revealed the presence of one group of high affinity receptors (Kd = 1.22 +/- 0.171 nM; Bmax = 209 +/- 14 fmol/mg protein). Competitive inhibition experiments with two highly specific nonpeptide ANG II antagonists, losartan (DuP 753), which is specific for the AT1 receptor subtype, and PD123319, which is specific for the AT2 subtype, demonstrated that the large majority of, if not all, ANG II receptors in rat renal preglomerular vessels correspond to the AT1 subtype. PMID:1299411

  13. Angiotensin II receptors and peritoneal dialysis-induced peritoneal fibrosis.

    PubMed

    Morinelli, Thomas A; Luttrell, Louis M; Strungs, Erik G; Ullian, Michael E

    2016-08-01

    The vasoactive hormone angiotensin II initiates its major hemodynamic effects through interaction with AT1 receptors, a member of the class of G protein-coupled receptors. Acting through its AT1R, angiotensin II regulates blood pressure and renal salt and water balance. Recent evidence points to additional pathological influences of activation of AT1R, in particular inflammation, fibrosis and atherosclerosis. The transcription factor nuclear factor κB, a key mediator in inflammation and atherosclerosis, can be activated by angiotensin II through a mechanism that may involve arrestin-dependent AT1 receptor internalization. Peritoneal dialysis is a therapeutic modality for treating patients with end-stage kidney disease. The effectiveness of peritoneal dialysis at removing waste from the circulation is compromised over time as a consequence of peritoneal dialysis-induced peritoneal fibrosis. The non-physiological dialysis solution used in peritoneal dialysis, i.e. highly concentrated, hyperosmotic glucose, acidic pH as well as large volumes infused into the peritoneal cavity, contributes to the development of fibrosis. Numerous trials have been conducted altering certain components of the peritoneal dialysis fluid in hopes of preventing or delaying the fibrotic response with limited success. We hypothesize that structural activation of AT1R by hyperosmotic peritoneal dialysis fluid activates the internalization process and subsequent signaling through the transcription factor nuclear factor κB, resulting in the generation of pro-fibrotic/pro-inflammatory mediators producing peritoneal fibrosis. PMID:27167177

  14. The blockade of the transient receptor potential vanilloid type 1 and fatty acid amide hydrolase decreases symptoms and central sequelae in the medial prefrontal cortex of neuropathic rats

    PubMed Central

    2011-01-01

    Background Neuropathic pain is a chronic disease resulting from dysfunction within the "pain matrix". The basolateral amygdala (BLA) can modulate cortical functions and interactions between this structure and the medial prefrontal cortex (mPFC) are important for integrating emotionally salient information. In this study, we have investigated the involvement of the transient receptor potential vanilloid type 1 (TRPV1) and the catabolic enzyme fatty acid amide hydrolase (FAAH) in the morphofunctional changes occurring in the pre-limbic/infra-limbic (PL/IL) cortex in neuropathic rats. Results The effect of N-arachidonoyl-serotonin (AA-5-HT), a hybrid FAAH inhibitor and TPRV1 channel antagonist, was tested on nociceptive behaviour associated with neuropathic pain as well as on some phenotypic changes occurring on PL/IL cortex pyramidal neurons. Those neurons were identified as belonging to the BLA-mPFC pathway by electrical stimulation of the BLA followed by hind-paw pressoceptive stimulus application. Changes in their spontaneous and evoked activity were studied in sham or spared nerve injury (SNI) rats before or after repeated treatment with AA-5-HT. Consistently with the SNI-induced changes in PL/IL cortex neurons which underwent profound phenotypic reorganization, suggesting a profound imbalance between excitatory and inhibitory responses in the mPFC neurons, we found an increase in extracellular glutamate levels, as well as the up-regulation of FAAH and TRPV1 in the PL/IL cortex of SNI rats. Daily treatment with AA-5-HT restored cortical neuronal activity, normalizing the electrophysiological changes associated with the peripheral injury of the sciatic nerve. Finally, a single acute intra-PL/IL cortex microinjection of AA-5-HT transiently decreased allodynia more effectively than URB597 or I-RTX, a selective FAAH inhibitor or a TRPV1 blocker, respectively. Conclusion These data suggest a possible involvement of endovanilloids in the cortical plastic changes

  15. Knockdown of Interleukin-1 Receptor Type-1 on Endothelial Cells Attenuated Stress-Induced Neuroinflammation and Prevented Anxiety-Like Behavior

    PubMed Central

    Wohleb, Eric S.; Patterson, Jenna M.; Sharma, Vikram; Quan, Ning

    2014-01-01

    Interleukin-1β (IL-1β) is an inflammatory cytokine that plays a prominent role in stress-induced behavioral changes. In a model of repeated social defeat (RSD), elevated IL-1β expression in the brain was associated with recruitment of primed macrophages that were necessary for development of anxiety-like behavior. Moreover, microglia activation and anxiety-like behavior associated with RSD did not occur in IL-1 receptor type-1 knock-out (IL-1R1KO) mice. Therefore, the objective of this study was to examine the role of IL-1 signaling in RSD-induced macrophage trafficking to the brain and anxiety-like behavior. Initial studies revealed that RSD did not increase circulating myeloid cells in IL-1R1KO mice, resulting in limited macrophage trafficking to the brain. In addition, IL-1R1KO bone marrow-chimera mice showed that IL-1R1 expression was essential for macrophage trafficking into the brain. To differentiate cellular mediators of stress-induced IL-1 signaling, endothelial-specific IL-1R1 knock-down (eIL-1R1kd) mice were used. Both wild-type (WT) and eIL-1R1kd mice had increased circulating monocytes, recruitment of macrophages to the brain, and altered microglia activation after RSD. Nonetheless, RSD-induced expression of IL-1β, TNF-α, and IL-6 mRNA in brain CD11b+ cells was attenuated in eIL-1R1kd mice compared with WT. Moreover, anxiety-like behavior did not develop in eIL-1R1kd mice. Collectively, these findings demonstrated that there was limited RSD-induced priming of myeloid cells in IL-1R1KO mice and disrupted propagation of neuroinflammatory signals in the brain of eIL-1R1kd mice. Furthermore, these data showed that transduction of IL-1 signaling by endothelial cells potentiates stress-induced neuroinflammation and promotes anxiety-like behavior. PMID:24523548

  16. Calcium-Dependent Energetics of Calmodulin Domain Interactions with Regulatory Regions of the Ryanodine Receptor Type 1 (RyR1)

    PubMed Central

    Newman, Rhonda A.; Sorensen, Brenda R.; Kilpatrick, Adina M.; Shea, Madeline A.

    2014-01-01

    Calmodulin (CaM) plays a vital role in calcium homeostasis by allosterically modulating intracellular calcium channels including the homo-tetrameric human Ryanodine Receptor Type 1 (hRyR1). Apo (calcium-free) CaM activates hRyR1 while calcium-saturated CaM inhibits it. Two CaM-binding regions (residues 1975–1999 and 3614–3643) identified in each RyR1 monomer were proposed to allow CaM to bridge adjacent RyR1 subunits. We explored the distinct roles of CaM domains by using fluorescence anisotropy to determine the affinity of CaM1–148 (full-length), CaM1–80 (N-domain) and CaM76–148 (C-domain) for peptides encompassing hRyR1 residues 1975–1999 or 3614–3643. Both CaM1–148 and CaM76–148 associated in a calcium-independent manner with similar affinities for hRyR1(3614–3643)p while CaM1–80 required calcium and bound ~250-fold more weakly. Association of CaM1–148, CaM1–80 and CaM76–148 with hRyR1(1975–1999)p was much less favorable than with hRyR1(3614–3643)p; differences between the two CaM domains were smaller. Equilibrium calcium titrations monitored by steady-state fluorescence demonstrated that both hRyR1 peptides increased the calcium-binding affinity of both CaM domains. These thermodynamic properties support a prior model in which the CaM C-domain associates with RyR1(3614–3643) at low levels of calcium, positioning CaM to rapidly respond to calcium efflux. However, the affinity of the N-domain of CaM for hRyR1(1975–1999)p is insufficient to explain a model in which CaM bridges adjacent RyR1 subunits within the tetramer. This indicates that other protein factors or properties of the tertiary or quaternary structure of hRyR1 contribute to the energetics of CaM-mediated regulation. PMID:25145833

  17. Malignant hyperthermia susceptibility arising from altered resting coupling between the skeletal muscle L-type Ca2+ channel and the type 1 ryanodine receptor

    PubMed Central

    Eltit, Jose Miguel; Bannister, Roger A.; Moua, Ong; Altamirano, Francisco; Hopkins, Philip M.; Pessah, Isaac N.; Molinski, Tadeusz F.; López, Jose R.; Beam, Kurt G.; Allen, Paul D.

    2012-01-01

    Malignant hyperthermia (MH) susceptibility is a dominantly inherited disorder in which volatile anesthetics trigger aberrant Ca2+ release in skeletal muscle and a potentially fatal rise in perioperative body temperature. Mutations causing MH susceptibility have been identified in two proteins critical for excitation–contraction (EC) coupling, the type 1 ryanodine receptor (RyR1) and CaV1.1, the principal subunit of the L-type Ca2+ channel. All of the mutations that have been characterized previously augment EC coupling and/or increase the rate of L-type Ca2+ entry. The CaV1.1 mutation R174W associated with MH susceptibility occurs at the innermost basic residue of the IS4 voltage-sensing helix, a residue conserved among all CaV channels [Carpenter D, et al. (2009) BMC Med Genet 10:104–115.]. To define the functional consequences of this mutation, we expressed it in dysgenic (CaV1.1 null) myotubes. Unlike previously described MH-linked mutations in CaV1.1, R174W ablated the L-type current and had no effect on EC coupling. Nonetheless, R174W increased sensitivity of Ca2+ release to caffeine (used for MH diagnostic in vitro testing) and to volatile anesthetics. Moreover, in CaV1.1 R174W-expressing myotubes, resting myoplasmic Ca2+ levels were elevated, and sarcoplasmic reticulum (SR) stores were partially depleted, compared with myotubes expressing wild-type CaV1.1. Our results indicate that CaV1.1 functions not only to activate RyR1 during EC coupling, but also to suppress resting RyR1-mediated Ca2+ leak from the SR, and that perturbation of CaV1.1 negative regulation of RyR1 leak identifies a unique mechanism that can sensitize muscle cells to MH triggers. PMID:22547813

  18. Malignant hyperthermia susceptibility arising from altered resting coupling between the skeletal muscle L-type Ca2+ channel and the type 1 ryanodine receptor.

    PubMed

    Eltit, Jose Miguel; Bannister, Roger A; Moua, Ong; Altamirano, Francisco; Hopkins, Philip M; Pessah, Isaac N; Molinski, Tadeusz F; López, Jose R; Beam, Kurt G; Allen, Paul D

    2012-05-15

    Malignant hyperthermia (MH) susceptibility is a dominantly inherited disorder in which volatile anesthetics trigger aberrant Ca(2+) release in skeletal muscle and a potentially fatal rise in perioperative body temperature. Mutations causing MH susceptibility have been identified in two proteins critical for excitation-contraction (EC) coupling, the type 1 ryanodine receptor (RyR1) and Ca(V)1.1, the principal subunit of the L-type Ca(2+) channel. All of the mutations that have been characterized previously augment EC coupling and/or increase the rate of L-type Ca(2+) entry. The Ca(V)1.1 mutation R174W associated with MH susceptibility occurs at the innermost basic residue of the IS4 voltage-sensing helix, a residue conserved among all Ca(V) channels [Carpenter D, et al. (2009) BMC Med Genet 10:104-115.]. To define the functional consequences of this mutation, we expressed it in dysgenic (Ca(V)1.1 null) myotubes. Unlike previously described MH-linked mutations in Ca(V)1.1, R174W ablated the L-type current and had no effect on EC coupling. Nonetheless, R174W increased sensitivity of Ca(2+) release to caffeine (used for MH diagnostic in vitro testing) and to volatile anesthetics. Moreover, in Ca(V)1.1 R174W-expressing myotubes, resting myoplasmic Ca(2+) levels were elevated, and sarcoplasmic reticulum (SR) stores were partially depleted, compared with myotubes expressing wild-type Ca(V)1.1. Our results indicate that Ca(V)1.1 functions not only to activate RyR1 during EC coupling, but also to suppress resting RyR1-mediated Ca(2+) leak from the SR, and that perturbation of Ca(V)1.1 negative regulation of RyR1 leak identifies a unique mechanism that can sensitize muscle cells to MH triggers. PMID:22547813

  19. Human Induced Pluripotent Stem Cell-Derived Cardiac Progenitor Cells in Phenotypic Screening: A Transforming Growth Factor-β Type 1 Receptor Kinase Inhibitor Induces Efficient Cardiac Differentiation.

    PubMed

    Drowley, Lauren; Koonce, Chad; Peel, Samantha; Jonebring, Anna; Plowright, Alleyn T; Kattman, Steven J; Andersson, Henrik; Anson, Blake; Swanson, Bradley J; Wang, Qing-Dong; Brolen, Gabriella

    2016-02-01

    Several progenitor cell populations have been reported to exist in hearts that play a role in cardiac turnover and/or repair. Despite the presence of cardiac stem and progenitor cells within the myocardium, functional repair of the heart after injury is inadequate. Identification of the signaling pathways involved in the expansion and differentiation of cardiac progenitor cells (CPCs) will broaden insight into the fundamental mechanisms playing a role in cardiac homeostasis and disease and might provide strategies for in vivo regenerative therapies. To understand and exploit cardiac ontogeny for drug discovery efforts, we developed an in vitro human induced pluripotent stem cell-derived CPC model system using a highly enriched population of KDR(pos)/CKIT(neg)/NKX2.5(pos) CPCs. Using this model system, these CPCs were capable of generating highly enriched cultures of cardiomyocytes under directed differentiation conditions. In order to facilitate the identification of pathways and targets involved in proliferation and differentiation of resident CPCs, we developed phenotypic screening assays. Screening paradigms for therapeutic applications require a robust, scalable, and consistent methodology. In the present study, we have demonstrated the suitability of these cells for medium to high-throughput screens to assess both proliferation and multilineage differentiation. Using this CPC model system and a small directed compound set, we identified activin-like kinase 5 (transforming growth factor-β type 1 receptor kinase) inhibitors as novel and potent inducers of human CPC differentiation to cardiomyocytes. Significance: Cardiac disease is a leading cause of morbidity and mortality, with no treatment available that can result in functional repair. This study demonstrates how differentiation of induced pluripotent stem cells can be used to identify and isolate cell populations of interest that can translate to the adult human heart. Two separate examples of phenotypic

  20. Angiotensin II binding to cultured bovine adrenal chromaffin cells: identification of angiotensin II receptors

    SciTech Connect

    Boyd, V.L.; Printz, M.P.

    1986-03-05

    Physiological experiments have provided evidence that angiotensin II stimulates catecholamine secretion from the adrenal gland. Their laboratory and others have now shown by receptor autoradiography the presence of angiotensin II receptors (AIIR) in bovine and rat adrenal medulla. In order to extend these studies they have undertaken to define AIIR on cultured bovine adrenal chromaffin cells. Cells were isolated using the method of Levitt including cell enrichment with Percoll gradient centrifugation. Primary cultures of bovine adrenal medullary cells were maintained in DME/F12 medium containing 10% FCS. Cells were characterized by immunocytochemistry for Met- and Leu-enkephalin, PNMT, DBH and Chromagranin A. Cultured cells bind with high affinity and specificity (/sup 125/I)-ANG II yielding a K/sub D/ of 0.74 nM and B/sub max/ of 24,350 sites/cell. After Percoll treatment values of .77 nm and 34,500 sites/cell are obtained. K/sub D/ values are in close agreement with that obtained in adrenal slices by Healy. Competition studies identify a rank order of binding by this receptor similar to that of other tissues. They conclude that cultured chromaffin cells provide a suitable model system for the investigation and characterization of the ANG II receptor and for cellular studies of its functional significance.

  1. Angiotensin II type 2 (AT2) receptors have a major somatodendritic distribution in vasopressin-containing neurons in the mouse hypothalamic paraventricular nucleus

    PubMed Central

    Coleman, Christal G.; Anrather, Josef; Iadecola, Costantino; Pickel, Virginia M.

    2009-01-01

    The hypothalamic paraventricular nucleus (PVN) and angiotensin II (AngII) play critical roles in cardiovascular and neurohumoral regulation ascribed in part to vasopressin (VP) release. The AngII actions in the PVN are mediated largely through AngII type 1 (AT1) receptors. However, there is indirect evidence that the functionally elusive central AngII type 2 (AT2) receptors are also mediators of AngII signaling in the PVN. We used electron microscopic dual immunolabeling of antisera recognizing the AT2 receptor and VP to test the hypothesis that PVN neurons expressing VP are among the cellular sites where this receptor has a subcellular distribution conducive to local activation. Immunoreactivity for the AT2 receptor was detected in somatodendritic profiles, of which ~60% of the somata and ~28% of the dendrites also contained VP. In comparison with somata and dendrites, axons, axon terminals, and glia less frequently contained the AT2 receptor. Somatic labeling for the AT2 receptor was often seen in the cytoplasm near the Golgi lamellae and other endomembrane structures implicated in receptor trafficking. AT2 receptor immunoreactivity in dendrites was commonly localized to cytoplasmic endomembranes, but was occasionally observed on extra- or peri-synaptic portions of the plasma membrane apposed by astrocytic processes or by unlabeled axon terminals. The labeled dendritic plasmalemmal segments containing AT2 receptors received asymmetric excitatory-type or more rarely symmetric inhibitory-type contacts from unlabeled axon terminals containing dense core vesicles, many of which are known to store neuropeptides. These results provide the first ultrastructural evidence that AT2 receptors in PVN neurons expressing vasopressin and other neuromodulators are strategically positioned for surface activation by AngII and/or intracellular trafficking. PMID:19539723

  2. Transforming growth factor receptor type II (ec-TβR II) behaves as a halophile.

    PubMed

    Saini, Komal; Khan, M Ashhar I; Chakrapani, Sumit; Deep, Shashank

    2015-01-01

    The members of transforming growth factor β family (TGF-β) are multifunctional proteins but their main role is to control cell proliferation and differentiation. Polypeptides of TGF-β family function by binding to two related, functionally distinct transmembrane receptor kinases, first to the type II (TβR II) followed by type I receptor (TβR I). The paper describes, in details, the stability of wt-ec-TβR II under different conditions. The stability of wt-ec-TβR II was observed at different pH and salt concentration using fluorescence spectroscopy. Stability of ec-TβR II decreases with decrease in pH. Interestingly, the addition of salt increases the stability of the TβRII at pH 5.0 as observed for halophiles. Computational analysis using DELPHI suggests that this is probably due to the decrease in repulsion between negatively charged residues at surface on the addition of salt. This is further confirmed by the change in the stability of receptor on mutation of some of the residues (D32A) at surface. PMID:25316422

  3. Characterization of the Igf-II Binding Site of the IGF-II/MAN-6-P Receptor Extracellular Domain.

    NASA Astrophysics Data System (ADS)

    Garmroudi, Farideh

    1995-01-01

    In mammals, insulin-like growth factor II (IGF -II) and glycoproteins bearing the mannose 6-phosphate (Man -6-P) recognition marker bind with high affinity to the same receptor. The functional consequences of IGF-II binding to the receptor at the cell surface are not clear. In these studies, we sought to broaden our understanding of the functional regions of the receptor regarding its IGF -II binding site. The IGF-II binding/cross-linking domain of the IGF-II/Man-6-P receptor was mapped by sequencing receptor fragments covalently attached to IGF-II. Purified rat placental or bovine liver receptors were affinity-labeled, with ^{125}I-IGF-II and digested with endoproteinase Glu-C. Analysis of digests by gel electrophoresis revealed a major radiolabeled band of 18 kDa, which was purified by gel filtration chromatography followed by reverse-phase HPLC and electroblotting. Sequence analysis revealed that, the peptide S(H)VNSXPMF, located within extracellular repeat 10 and beginning with serine 1488 of the bovine receptor, was the best candidate for the IGF-II cross-linked peptide. These data indicated that residues within repeats 10-11 were important for IGF -II binding. To define the location of the IGF-II binding site further, a nested set of six human receptor cDNA constructs was designed to produce epitope-tagged fusion proteins encompassing the region between repeats 8 and 11 of the human IGF-II/Man-6-P receptor extracellular domain. These truncated receptors were transiently expressed in COS-7 cells, immunoprecipitated and analyzed for their abilities to bind and cross-link to IGF-II. All of the constructs were capable of binding/cross-linking to IGF-II, except for the 9.0-11 construct. Displacement curve analysis indicated that the truncated receptors were approximately equivalent in IGF-II binding affinity, but were of 5- to 10-fold lower affinity than full-length receptors. Sequencing of the 9.0-11 construct indicated the presence of a point mutation

  4. The angiotensin II-AT1 receptor stimulates reactive oxygen species within the cell nucleus

    SciTech Connect

    Pendergrass, Karl D.; Gwathmey, TanYa M.; Michalek, Ryan D.; Grayson, Jason M.; Chappell, Mark C.

    2009-06-26

    We and others have reported significant expression of the Ang II Type 1 receptor (AT1R) on renal nuclei; thus, the present study assessed the functional pathways and distribution of the intracellular AT1R on isolated nuclei. Ang II (1 nM) stimulated DCF fluorescence, an intranuclear indicator of reactive oxygen species (ROS), while the AT1R antagonist losartan or the NADPH oxidase (NOX) inhibitor DPI abolished the increase in ROS. Dual labeling of nuclei with antibodies against nucleoporin 62 (Nup62) and AT1R or the NADPH oxidase isoform NOX4 revealed complete overlap of the Nup62 and AT1R (99%) by flow cytometry, while NOX4 was present on 65% of nuclei. Treatment of nuclei with a PKC agonist increased ROS while the PKC inhibitor GF109203X or PI3 kinase inhibitor LY294002 abolished Ang II stimulation of ROS. We conclude that the Ang II-AT1R-PKC axis may directly influence nuclear function within the kidney through a redox sensitive pathway.

  5. Testicular gonadotropin-releasing hormone II receptor (GnRHR-II) knockdown constitutively impairs diurnal testosterone secretion in the boar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The second mammalian GnRH isoform (GnRH-II) and its specific receptor (GnRHR-II) are highly expressed in the testis, suggesting an important role in testis biology. Gene coding errors prevent the production of GnRH-II and GnRHR-II in many species, but both genes are functional in swine. We have demo...

  6. A Novel Approach to Identify Two Distinct Receptor Binding Surfaces of Insulin-like Growth Factor II*S⃞

    PubMed Central

    Alvino, Clair L.; McNeil, Kerrie A.; Ong, Shee Chee; Delaine, Carlie; Booker, Grant W.; Wallace, John C.; Whittaker, Jonathan; Forbes, Briony E.

    2009-01-01

    Very little is known about the residues important for the interaction of insulin-like growth factor II (IGF-II) with the type 1 IGF receptor (IGF-1R) and the insulin receptor (IR). Insulin, to which IGF-II is homologous, is proposed to cross-link opposite halves of the IR dimer through two receptor binding surfaces, site 1 and site 2. In the present study we have analyzed the contribution of IGF-II residues equivalent to insulin's two binding surfaces toward the interaction of IGF-II with the IGF-1R and IR. Four “site 1” and six “site 2” analogues were produced and analyzed in terms of IGF-1R and IR binding and activation. The results show that Val43, Phe28, and Val14 (equivalent to site 1) are critical to IGF-1R and IR binding, whereas mutation to alanine of Gln18 affects only IGF-1R and not IR binding. Alanine substitutions at Glu12, Asp15, Phe19, Leu53, and Glu57 analogues resulted in significant (>2-fold) decreases in affinity for both the IGF-1R and IR. Furthermore, taking a novel approach using a monomeric, single-chain minimized IGF-1R we have defined a distinct second binding surface formed by Glu12, Phe19, Leu53, and Glu57 that potentially engages the IGF-1R at one or more of the FnIII domains. PMID:19139090

  7. Synthesis and biological evaluation of a new angiotensin II receptor antagonist.

    PubMed

    Zheng, H-l; Zhu, W-b; Wu, D; Da, Y-j; Yan, Y-J; Bian, J; Chen, Z-l

    2014-12-01

    The design, synthesis, in vitro and in vivo evaluation of (2 R,6 S)-4-({1-[2-(1 H-tetrazol-5-yl)phenyl]-1 H-indol-4-yl}methyl)-2,6-dimethylmorpholine, compound 1, as a novel angiotensin II receptor antagonist is outlined. Radioligand binding assays showed that 1 displayed a high affinity for the angiotensin II type 1receptor with IC50 value of 0.82 nM. It acted as a potent anti-hypertensive derivative (maximal reduction of mean arterial pressure of 47 mm Hg at 10 mg/kg po in spontaneously hypertensive rat producing a dose-dependent fall in blood pressure following oral administration lasting beyond 10 h. Acute toxicity tests measured the LD50 of 1 value as 2431.7 mg/kg, which is higher than Losartan (LD50=2248 mg/kg). In addition further testing showed that 1 also demonstrated efficient anti-proliferative activity in vitro and anti-prostate cancer activity in vivo were also found. Taken together this compound could be considered as an effective and durable anti-hypertension drug candidate with additional anti-prostate cancer activity. These encouraging results are deserved of further investigation towards its use for therapeutic benefit. PMID:24573978

  8. [Ca{sup 2+}]{sub i} and PKC-{alpha} are involved in the inhibitory effects of Ib, a novel nonpeptide AngiotensinII subtype AT{sub 1} receptor antagonist, on AngiotensinII-induced vascular contraction in vitro

    SciTech Connect

    Wang Yu; Wang Wei; Wang Qiujuan Wu Jinhui; Xu Jinyi; Wu Xiaoming

    2007-12-07

    The vasoactive peptide AngiotensinII (AngII) is an important factor in the cardiovascular system, exerting most of its effects through AngII receptor type 1 (AT{sub 1}). Ib, a new nonpeptide AT{sub 1} receptor antagonist, has been observed to play a positive role in the treatment of hypertension in preclinical tests. In this study, the inhibitory effects of Ib on AngII-induced vascular contraction in vitro were investigated, and its molecular mechanisms were further explored. In endothelium-denuded aortic rings from rabbits, Ib produced a rightward shift in the concentration-response curve for AngII with a decrease in the maximal contractile response and the pD{sub 2}{sup '} was 7.29. In vascular smooth muscle cells (VSMCs), the specific binding of [{sup 125}I]AngII to AT{sub 1} receptors was inhibited by Ib in a concentration-dependent manner with IC{sub 50} value of 0.96 nM. Ib could inhibit both AngII-induced Ca{sup 2+} mobilization from internal stores and Ca{sup 2+} influx. Moreover, the translocation of PKC-{alpha} stimulated by AngII was inhibited by Ib. Thus, the inhibitory effects of Ib might be related with the depression on AngII-induced increase in [Ca{sup 2+}]{sub i} and translocation of PKC-{alpha} through blocking AT{sub 1} receptors.

  9. FCRL6 is an MHC class II receptor1

    PubMed Central

    Schreeder, Daniel M.; Cannon, John P.; Wu, Jiongru; Li, Ran; Shakhmatov, Mikhail A.; Davis, Randall S.

    2016-01-01

    Receptors for the Fc portion (FCR) of Ig have been extensively characterized and are known to regulate humoral responses, but members of the closely related FCR-like (FCRL) family have not been found to bind Ig and to date no ligand has been identified for any FCRL. Using a cell-based GFP reporter system and a recombinant Fc chimeric protein, we show that human FCRL6, a receptor selectively expressed by cytotoxic T and NK cells, directly binds HLA-DR, a major histocompatibility complex (MHC) class II molecule. Given the similarity among constant regions of Ig and MHC molecules, these findings suggest that representatives of the FCR and FCRL multigene families may have independently evolved to engage two ancestral elements fundamental to adaptive immunity. This discovery may offer new insight into the interaction between cytotoxic lymphocytes and antigen presenting cells and may have important implications for better understanding HLA disease susceptibility and pathogenesis. PMID:20519654

  10. Diabetes Type 1

    MedlinePlus

    Diabetes means your blood glucose, or blood sugar, levels are too high. With type 1 diabetes, your pancreas does not make insulin. Insulin is ... kidneys, nerves, and gums and teeth. Type 1 diabetes happens most often in children and young adults ...

  11. Angiotensin II and angiotensin II receptor blocker modulate the arrhythmogenic activity of pulmonary veins

    PubMed Central

    Chen, Yi-Jen; Chen, Yao-Chang; Tai, Ching-Tai; Yeh, Hung-I; Lin, Cheng-I; Chen, Shih-Ann

    2005-01-01

    Angiotensin II receptor blockers (AIIRBs) have been shown to prevent atrial fibrillation. The pulmonary veins (PVs) are the most important focus for the generation of atrial fibrillation. The aim of this study was to evaluate whether angiotensin II or AIIRB may change the arrhythmogenic activity of the PVs. Conventional microelectrodes and whole-cell patch clamps were used to investigate the action potentials (APs) and ionic currents in isolated rabbit PV tissue and single cardiomyocytes before and after administering angiotensin II or losartan (AIIRB). In the tissue preparations, angiotensin II induced delayed after-depolarizations (1, 10, and 100 nM) and accelerated the automatic rhythm (10 and 100 nM). Angiotensin II (100 nM) prolonged the AP duration and increased the contractile force (10 and 100 nM). Losartan (1 and 10 μM) inhibited the automatic rhythm. Losartan (10 μM) prolonged the AP duration and reduced the contractile force (1 and 10 μM). Angiotensin II reduced the transient outward potassium current (Ito) but increased the L-type calcium, delayed rectifier potassium (IK), transient inward (Iti), pacemaker, and Na+–Ca2+ exchanger (NCX) currents in the PV cardiomyocytes. Losartan decreased the Ito, IK, Iti, and NCX currents. In conclusion, angiotensin II and AIIRB modulate the PV electrical activity, which may play a role in the pathophysiology of atrial fibrillation. PMID:16273119

  12. Nigral dopamine type-1 receptors are reduced in Huntington's disease: A postmortem autoradiographic study using ( sup 3 H)SCH 23390 and correlation with ( sup 3 H)forskolin binding

    SciTech Connect

    Filloux, F.; Wagster, M.V.; Folstein, S.; Price, D.L.; Hedreen, J.C.; Dawson, T.M.; Wamsley, J.K. )

    1990-11-01

    Intrastriatal injection of excitatory amino acids, particularly quinolinic acid, has been proposed as an animal model of Huntington's disease. Such neurotoxic lesions of caudate-putamen result in marked dopamine type-1 (D1) receptor losses in the injected nuclei as well as in the ipsilateral substantia nigra pars reticulata. Postmortem human substantia nigra from Huntington's disease brains and from control brains were examined using in vitro autoradiography. A marked reduction in ({sup 3}H)SCH 23390 binding (labeling D1 receptors) in the substantia nigra of postmortem brains of Huntington's patients was identified, thus paralleling the alterations seen in the animal models. A positive, statistically significant correlation was also encountered between D1 receptor binding (labeled by ({sup 3}H)SCH 23390) and ({sup 3}H)forskolin binding (which identifies adenylate cyclase, a second messenger system linked to D1 receptor activation). The results suggest that in the human--as in lower vertebrates--D1 receptors are located on striatonigral terminals and that D1 receptor loss tends to be paralleled by a reduction in adenylate cyclase. Radioactive agents selective for the D1 receptor may prove useful in future studies of Huntington's disease using positron emission tomography scanning.

  13. 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

  14. Identification of Two Laminin-Binding Fimbriae, the Type 1 Fimbria of Salmonella enterica Serovar Typhimurium and the G Fimbria of Escherichia coli, as Plasminogen Receptors

    PubMed Central

    Kukkonen, Maini; Saarela, Sirkku; Lähteenmäki, Kaarina; Hynönen, Ulla; Westerlund-Wikström, Benita; Rhen, Mikael; Korhonen, Timo K.

    1998-01-01

    Escherichia coli strains carrying recombinant plasmids encoding either the type 1 fimbria of Salmonella enterica serovar Typhimurium or the G fimbria of E. coli exhibited binding of human 125I-Glu-plasminogen and enhanced the tissue-type plasminogen activator-catalyzed conversion of plasminogen to plasmin. Purified type 1 or G fimbriae similarly bound plasminogen and enhanced its activation. The binding of plasminogen did not involve the characteristic carbohydrate-binding property of the fimbriae but was inhibited at low concentrations by the lysine analog ɛ-aminocaproic acid. Because these fimbrial types bind to laminin of basement membranes (M. Kukkonen et al., Mol. Microbiol. 7:229–237, 1993; S. Saarela et al., Infect. Immun. 64:2857–2860, 1996), the results demonstrate a structural unity in the creation and targeting of bacterium-bound proteolytic plasmin activity to basement membranes. PMID:9746604

  15. Histamine up-regulates fibroblast growth factor receptor 1 and increases FOXP2 neurons in cultured neural precursors by histamine type 1 receptor activation: conceivable role of histamine in neurogenesis during cortical development in vivo

    PubMed Central

    2013-01-01

    Background During rat development, histamine (HA) is one of the first neuroactive molecules to appear in the brain, reaching its maximal value at embryonic day 14, a period when neurogenesis of deep layers is occurring in the cerebral cortex, suggesting a role of this amine in neuronal specification. We previously reported, using high-density cerebrocortical neural precursor cultures, that micromolar HA enhanced the effect of fibroblast growth factor (FGF)-2 on proliferation, and that HA increased neuronal differentiation, due to HA type 1 receptor (H1R) activation. Results Clonal experiments performed here showed that HA decreased colony size and caused a significant increase in the percentage of clones containing mature neurons through H1R stimulation. In proliferating precursors, we studied whether HA activates G protein-coupled receptors linked to intracellular calcium increases. Neural cells presented an increase in cytoplasmic calcium even in the absence of extracellular calcium, a response mediated by H1R. Since FGF receptors (FGFRs) are known to be key players in cell proliferation and differentiation, we determined whether HA modifies the expression of FGFRs1-4 by using RT-PCR. An important transcriptional increase in FGFR1 was elicited after H1R activation. We also tested whether HA promotes differentiation specifically to neurons with molecular markers of different cortical layers by immunocytochemistry. HA caused significant increases in cells expressing the deep layer neuronal marker FOXP2; this induction of FOXP2-positive neurons elicited by HA was blocked by the H1R antagonist chlorpheniramine in vitro. Finally, we found a notable decrease in FOXP2+ cortical neurons in vivo, when chlorpheniramine was infused in the cerebral ventricles through intrauterine injection. Conclusion These results show that HA, by activating H1R, has a neurogenic effect in clonal conditions and suggest that intracellular calcium elevation and transcriptional up

  16. Effects of Urotensin II Receptor Antagonist, GSK1440115, in Asthma

    PubMed Central

    Portnoy, Alison; Kumar, Sanjay; Behm, David J.; Mahar, Kelly M.; Noble, Robert B.; Throup, John P.; Russ, Steven F.

    2013-01-01

    Background: Urotensin II (U-II) is highly expressed in the human lung and has been implicated in regulating respiratory physiology in preclinical studies. Our objective was to test antagonism of the urotensin (UT) receptor by GSK1440115, a novel, competitive, and selective inhibitor of the UT receptor, as a therapeutic strategy for the treatment of asthma. Methods: Safety, tolerability, and pharmacokinetics (PK) of single doses of GSK1440115 (1–750 mg) were assessed in a Phase I, placebo controlled study in 70 healthy subjects. In a Phase Ib study, 12 asthmatic patients were randomized into a two-period, single-blind crossover study and treated with single doses of 750 mg GSK1440115 or placebo and given a methacholine challenge. Results: Administration of GSK1440115 was safe and well-tolerated in healthy subjects and asthmatic patients. In both studies, there was a high degree of variability in the observed PK following oral dosing with GSK1440115 at all doses. There was a marked food effect in healthy subjects at the 50 mg dose. In the presence of food at the 750 mg dose, the time to maximal concentration was between 2 and 6 h and the terminal half-life was short at approximately 2 h. All asthmatic patients maintained greater than the predicted concentration levels necessary to achieve predicted 96% receptor occupancy for ≥3 h (between 4 and 7 h post-dose). There were no apparent trends or relationships between the systemic plasma exposure of GSK1440115 and pharmacodynamic endpoints, PC20 after methacholine challenge and FEV1, in asthmatics. Conclusion: While GSK1440115 was safe and well-tolerated, it did not induce bronchodilation in asthmatics, or protect against methacholine-induced bronchospasm, suggesting that acute UT antagonism is not likely to provide benefit as an acute bronchodilator in this patient population. PMID:23641215

  17. Type 1 diabetes

    PubMed Central

    Atkinson, Mark A; Eisenbarth, George S; Michels, Aaron W

    2015-01-01

    Over the past decade, knowledge of the pathogenesis and natural history of type 1 diabetes has grown substantially, particularly with regard to disease prediction and heterogeneity, pancreatic pathology, and epidemiology. Technological improvements in insulin pumps and continuous glucose monitors help patients with type 1 diabetes manage the challenge of lifelong insulin administration. Agents that show promise for averting debilitating disease-associated complications have also been identified. However, despite broad organisational, intellectual, and fiscal investments, no means for preventing or curing type 1 diabetes exists, and, globally, the quality of diabetes management remains uneven. This Seminar discusses current progress in epidemiology, pathology, diagnosis, and treatment of type 1 diabetes, and prospects for an improved future for individuals with this disease. PMID:23890997

  18. Ground states of multi-band type-I and type-1.5 superconductors and interlaced type-I/type-II layered superconducting structures in external magnetic field

    NASA Astrophysics Data System (ADS)

    Garaud, Julien; Carlstrom, Johan; Babaev, Egor

    2011-03-01

    We report a numerical study of magnetic field-induced structures in multiband/multi-component superconductors and type-I/type-II multilayers. The magnetic ground state in these different regimes shows very rich structure formation. In particular we report vortex cluster formation in the cases of strong interband Josephson coupling. The results in particular can be applied to layered structures manufactured from interlaced layers of type-I and type-II superconductors yielding effectively the type-1.5 superconducting behavior with tunable intercomponent couplings. Supported by NSF CAREER Award DMR-0955902, Knut and Alice Wallenberg Foundation through the Royal Swedish Academy of Sciences and Swedish Research Council.

  19. Synthesis and biological evaluation of novel potent angiotensin II receptor antagonists with anti-hypertension effect.

    PubMed

    Nie, Yong-yan; Da, Ya-jing; Zheng, Hao; Yang, Xiao-xia; Jia, Lin; Wen, Cai-hong; Liang, Li-sha; Tian, Juan; Chen, Zhi-long

    2012-04-15

    A series of novel angiotensin II type 1 receptor antagonists were prepared. Radioligand binding assay suggested that compounds 1b and 1c could be recognized by the AT(1) receptor with an IC(50) value of 1.6 ± 0.09 nM and 2.64 ± 0.7 nM, respectively. In vivo anti-hypertension experiments showed that compounds (1a, 1b, 1c, 1e) elicited a significant decrease in SBP and DBP of spontaneous hypertensive rats (SHRs). The antihypertensive effects maintained for 10 h, which indicated that these compounds had a favorable blood pressure-lowering effect. Acute toxicity testing suggested that the LD(50) value of compound 1b was 2316.8 mg/kg which was lower than valsartan (LD(50)=307.50 mg/kg) but higher than losartan (LD(50)=2248 mg/kg). So they could be considered as novel anti-hypertension candidates and deserved for further investigation. PMID:22410249

  20. Spinal astrocytic activation contributes to both induction and maintenance of pituitary adenylate cyclase-activating polypeptide type 1 receptor-induced long-lasting mechanical allodynia in mice

    PubMed Central

    Yokai, Masafumi; Miyata, Atsuro

    2016-01-01

    Background Pituitary adenylate cyclase-activating polypeptide (PACAP) and its receptors are present in the spinal dorsal horn and dorsal root ganglia, suggesting an important role of PACAP–PACAP receptors signaling system in the modulation of spinal nociceptive transmission. We have previously reported that a single intrathecal injection of PACAP or a PACAP specific (PAC1) receptor selective agonist, maxadilan, in mice induced dose-dependent aversive behaviors, which lasted more than 30 min, and suggested that the maintenance of the nociceptive behaviors was associated with the spinal astrocytic activation. Results We found that a single intrathecal administration of PACAP or maxadilan also produced long-lasting hind paw mechanical allodynia, which persisted at least 84 days without affecting thermal nociceptive threshold. In contrast, intrathecal application of vasoactive intestinal polypeptide did not change mechanical threshold, and substance P, calcitonin gene-related peptide, or N-methyl-D-aspartate induced only transient mechanical allodynia, which disappeared within 21 days. Western blot and immunohistochemical analyses with an astrocytic marker, glial fibrillary acidic protein, revealed that the spinal PAC1 receptor stimulation caused sustained astrocytic activation, which also lasted more than 84 days. Intrathecal co-administration of L-α-aminoadipate, an astroglial toxin, with PACAP or maxadilan almost completely prevented the induction of the mechanical allodynia. Furthermore, intrathecal treatment of L-α-aminoadipate at 84 days after the PAC1 stimulation transiently reversed the mechanical allodynia accompanied by the reduction of glial fibrillary acidic protein expression level. Conclusion Our data suggest that spinal astrocytic activation triggered by the PAC1 receptor stimulation contributes to both induction and maintenance of the long-term mechanical allodynia. PMID:27175011

  1. Role of the monocyte chemoattractant protein-1/C-C chemokine receptor 2 signaling pathway in transient receptor potential vanilloid type 1 ablation-induced renal injury in salt-sensitive hypertension.

    PubMed

    Wang, Youping; Zhu, Mingjun; Xu, Hui; Cui, Lin; Liu, Weihong; Wang, Xiaoxiao; Shen, Si; Wang, Donna H

    2015-09-01

    Our recent studies indicate that the transient receptor potential vanilloid type 1 (TRPV1) channel may act as a potential regulator of monocyte/macrophage recruitment to reduce renal injury in salt-sensitive hypertension. This study tests the hypothesis that deletion of TRPV1 exaggerates salt-sensitive hypertension-induced renal injury due to enhanced inflammatory responses via monocyte chemoattractant protein-1 (MCP-1)/C-C chemokine receptor 2 (CCR2)-dependent pathways. Wild type (WT) and TRPV1-null mutant (TRPV1(-/-)) mice were subjected to uninephrectomy and deoxycorticosterone acetate (DOCA)-salt treatment for four weeks with or without the selective CCR2 antagonist, RS504393. DOCA-salt treatment increased systolic blood pressure (SBP) to the same degree in both strains, but increased urinary excretion of albumin and 8-isoprostane and decreased creatinine clearance with greater magnitude in TRPV1(-/-) mice compared to WT mice. DOCA-salt treatment also caused renal glomerulosclerosis, tubulointerstitial injury, collagen deposition, monocyte/macrophage infiltration, proinflammatory cytokine and chemokine production, and NF-κB activation in greater degree in TRPV1(-/-) mice compared to WT mice. Blockade of the CCR2 with RS504393 (4 mg/kg/day) had no effect on SBP in DOCA-salt-treated WT or TRPV1(-/-) mice compared to their respective controls. However, treatment with RS504393 ameliorated renal dysfunction and morphological damage, and prevented the increase in monocyte/macrophage infiltration, cytokine/chemokine production, and NF-κB activity in both DOCA-salt hypertensive strains with a greater effect in DOCA-salt-treated TRPV1(-/-) mice compared to DOCA-salt-treated WT mice. No differences in CCR2 protein expression in kidney were found between DOCA-salt-treated WT and TRPV1(-/-) mice with or without RS504393 treatment. Our studies for the first time indicate that deletion of TRPV1 aggravated renal injury in salt-sensitive hypertension via enhancing MCP-1

  2. Perinatal Nicotine Exposure Increases Angiotensin II Receptor-Mediated Vascular Contractility in Adult Offspring

    PubMed Central

    Xiao, DaLiao; Dasgupta, Chiranjib; Li, Yong; Huang, Xiaohui; Zhang, Lubo

    2014-01-01

    Previous studies have reported that perinatal nicotine exposure causes development of hypertensive phenotype in adult offspring. Aims The present study was to determine whether perinatal nicotine exposure causes an epigenetic programming of vascular Angiotensin II receptors (ATRs) and their-mediated signaling pathway leading to heightened vascular contraction in adult offspring. Main methods Nicotine was administered to pregnant rats via subcutaneous osmotic minipumps from day 4 of gestation to day 10 after birth. The experiments were conducted at 5 months of age of male offspring. Key Findings Nicotine treatment enhanced Angitension II (Ang II)-induced vasoconstriction and 20-kDa myosin light chain phosphorylation (MLC20-P) levels. In addition, the ratio of Ang II-induced tension/MLC-P was also significantly increased in nicotine-treated group compared with the saline group. Nicotine-mediated enhanced constrictions were not directly dependent on the changes of [Ca2+]i concentrations but dependent on Ca2+ sensitivity. Perinatal nicotine treatment significantly enhanced vascular ATR type 1a (AT1aR) but not AT1bR mRNA levels in adult rat offspring, which was associated with selective decreases in DNA methylation at AT1aR promoter. Contrast to the effect on AT1aR, nicotine decreased the mRNA levels of vascular AT2R gene, which was associated with selective increases in DNA methylation at AT2R promoter. Significance Our results indicated that perinatal nicotine exposure caused an epigenetic programming of vascular ATRs and their-mediated signaling pathways, and suggested that differential regulation of AT1R/AT2R gene expression through DNA methylation mechanism may be involved in nicotine-induced heightened vasoconstriction and development of hypertensive phenotype in adulthood. PMID:25265052

  3. Cell Type-Specific Modifications of Corticotropin-Releasing Factor (CRF) and its type 1 receptor (CRF1) on Startle Behavior and Sensorimotor Gating

    PubMed Central

    Flandreau, Elizabeth; Lu, Ailing; Ableitner, Martin; Geyer, Mark A; Holsboer, Florian; Deussing, Jan M

    2015-01-01

    The corticotropin-releasing factor (CRF) family of peptides and receptors coordinates the mammalian endocrine, autonomic, and behavioral responses to stress. Excessive CRF production has been implicated in the etiology of stress-sensitive psychiatric disorders such as posttraumatic stress disorder (PTSD), which is associated with alterations in startle plasticity. The CRF family of peptides and receptors mediate acute startle response changes during stress, and chronic CRF activation can induce startle abnormalities. To determine what neural circuits modulate startle in response to chronic CRF activation, transgenic mice overexpressing CRF throughout the central nervous system (CNS; CRF-COECNS) or restricted to inhibitory GABAergic neurons (CRF-COEGABA) were compared across multiple domains of startle plasticity. CRF overexpression throughout the CNS increased startle magnitude and reduced ability to inhibit startle (decreased habituation and decreased prepulse inhibition (PPI)), similar to previous reports of exogenous effects of CRF. Conversely, CRF overexpression confined to inhibitory neurons decreased startle magnitude but had no effect on inhibitory measures. Acute CRF receptor 1 (CRF1) antagonist treatment attenuated only the effects on startle induced by CNS-specific CRF overexpression. Specific deletion of CRF1 receptors from forebrain principal neurons failed to alter the effects of exogenous CRF or stress on startle, suggesting that these CRF1 expressing neurons are not required for CRF-induced changes in startle behaviors. These data indicate that the effects of CRF activation on startle behavior utilize an extensive neural circuit that includes both forebrain and non-forebrain regions. Furthermore, these findings suggest that the neural source of increased CRF release determines the startle phenotype elicited. It is conceivable that this may explain why disorders characterized by increased CRF in cerebrospinal fluid (e.g. PTSD and major depressive

  4. Cell type-specific modifications of corticotropin-releasing factor (CRF) and its type 1 receptor (CRF1) on startle behavior and sensorimotor gating.

    PubMed

    Flandreau, Elizabeth; Risbrough, Victoria; Lu, Ailing; Ableitner, Martin; Geyer, Mark A; Holsboer, Florian; Deussing, Jan M

    2015-03-01

    The corticotropin-releasing factor (CRF) family of peptides and receptors coordinates the mammalian endocrine, autonomic, and behavioral responses to stress. Excessive CRF production has been implicated in the etiology of stress-sensitive psychiatric disorders such as posttraumatic stress disorder (PTSD), which is associated with alterations in startle plasticity. The CRF family of peptides and receptors mediate acute startle response changes during stress, and chronic CRF activation can induce startle abnormalities. To determine what neural circuits modulate startle in response to chronic CRF activation, transgenic mice overexpressing CRF throughout the central nervous system (CNS; CRF-COE(CNS)) or restricted to inhibitory GABAergic neurons (CRF-COE(GABA)) were compared across multiple domains of startle plasticity. CRF overexpression throughout the CNS increased startle magnitude and reduced ability to inhibit startle (decreased habituation and decreased prepulse inhibition (PPI)), similar to previous reports of exogenous effects of CRF. Conversely, CRF overexpression confined to inhibitory neurons decreased startle magnitude but had no effect on inhibitory measures. Acute CRF receptor 1 (CRF1) antagonist treatment attenuated only the effects on startle induced by CNS-specific CRF overexpression. Specific deletion of CRF1 receptors from forebrain principal neurons failed to alter the effects of exogenous CRF or stress on startle, suggesting that these CRF1 expressing neurons are not required for CRF-induced changes in startle behaviors. These data indicate that the effects of CRF activation on startle behavior utilize an extensive neural circuit that includes both forebrain and non-forebrain regions. Furthermore, these findings suggest that the neural source of increased CRF release determines the startle phenotype elicited. It is conceivable that this may explain why disorders characterized by increased CRF in cerebrospinal fluid (e.g. PTSD and major depressive

  5. Nitric oxide preferentially induces type 1 T cell differentiation by selectively up-regulating IL-12 receptor β2 expression via cGMP

    PubMed Central

    Niedbala, Wanda; Wei, Xiao-qing; Campbell, Carol; Thomson, Duncan; Komai-Koma, Mousa; Liew, Foo Y.

    2002-01-01

    Nitric oxide plays an important role in immune regulation. We have shown that although high concentrations of NO generally were immune-suppressive, low concentrations of NO selectively enhanced the differentiation of T helper (Th)1 cells but not Th2 cells. This finding provided an explanation for the crucial role of NO in defense against intracellular pathogens. However, the mechanism for the selective induction of Th1 cells was unknown. We report here that at low concentrations, NO activates soluble guanylyl cyclase, leading to the up-regulation of cGMP, which selectively induces the expression of IL-12 receptor β2 but has no effect on IL-4 receptor. Because IL-12 and IL-4 are the key cytokines for induction of Th1 and Th2 cells, respectively, these results, therefore, provide the mechanism for the selective action of NO on T cell subset differentiation. Furthermore, this selectivity also applies to CD8+ cytotoxic and human T cells and, thus, demonstrates the general implication of this observation in immune regulation. Our results also provide an example of the regulation of cytokine receptor expression by NO. The selectivity of such action via cGMP suggests that it is amenable to therapeutic intervention. PMID:12451176

  6. Endothelial cell-specific aryl hydrocarbon receptor knockout mice exhibit hypotension mediated, in part, by an attenuated angiotensin II responsiveness

    PubMed Central

    Agbor, Larry N.; Elased, Khalid M.; Walker, Mary K.

    2011-01-01

    Hypotension in aryl hydrocarbon receptor knockout mice (ahr−/−) is mediated, in part, by a reduced contribution of angiotensin (Ang) II to basal blood pressure (BP). Since AHR is highly expressed in endothelial cells (EC), we hypothesized that EC-specific ahr−/− (ECahr−/−) mice would exhibit a similar phenotype. We generated ECahr−/− mice by crossing AHR floxed mice (ahrfx/fx) to mice expressing Cre recombinase driven by an EC-specific promoter. BP was assessed by radiotelemetry prior to and following an acute injection of Ang II or chronic treatment with an angiotensin converting enzyme inhibitor (ACEi). ECahr−/− mice were hypotensive (ECahr+/+: 116.1 ± 1.4; ECahr−/−: 107.4 ± 2.0 mmHg, n=11, p<0.05) and exhibited significantly different responses to Ang II and ACEi. While Ang II increased BP in both genotypes, the increase was sustained in ECahr+/+, whereas the increase in ECahr−/− mice steadily declined. Area under the curve analysis showed that Ang II-induced increase in diastolic BP (DBP) over 30 min was significantly lower in ECahr−/− mice (ECahr+/+ 1297 ± 223 mmHg/30 min; ECahr−/−AUC: 504 ± 138 mmHg/30 min, p<0.05). In contrast, while ACEi decreased BP in both genotypes, the subsequent rise in DBP after treatment was significantly delayed in the ECahr−/− mice. ECahr−/− mice also exhibited reduced vascular and adipose Ang II type 1 receptor (AT1R) expression, and reduced aortic Ang II-dependent vasoconstriction in the presence of vascular adipose. Taken together these data suggest that hypotension in ECahr−/− mice results from reduced vascular responsiveness to Ang II that is influenced by AT1R expression and adipose. PMID:21684261

  7. The effect of angiotensin II receptor blockers on hyperuricemia

    PubMed Central

    Wolff, Marissa L.; Cruz, Jennifer L.; Vanderman, Adam J.; Brown, Jamie N.

    2015-01-01

    The objective of this review was to explore the efficacy of angiotensin II receptor blockers (ARBs) for the treatment of hyperuricemia in individuals diagnosed with gout or hyperuricemia defined as ⩾7 mg/dl at baseline. A literature search of MEDLINE (1946 to June 2015) and EMBASE (1947 to June 2015) was conducted. The following search terms were used: ‘uric acid’, ‘urate transporter’, ‘gout’, ‘angiotensin II receptor blockers’, ‘hyperuricemia’ and the names for individual ARBs, as well as any combinations of these terms. Studies were excluded that did not explore fractional excretion or serum uric acid as an endpoint, if patients did not have a diagnosis of gout or hyperuricemia at baseline, or if they were non-English language. A total of eight studies met the inclusion criteria. Of the eight studies identified, six explored ARB monotherapy and two studies investigated ARBs as adjunct therapy. Losartan demonstrated statistically significant reductions in serum uric acid levels or increases in fractional excretion of uric acid in all studies, whereas no other ARB reached statistical benefit. The effect of ARBs on the occurrence of gout attacks or other clinical outcomes were not represented. Four studies evaluated safety effects of these agents indicating abnormalities such as minor changes in lab values. In conclusion, losartan is the only ARB that has consistently demonstrated a significant reduction in serum uric acid levels, although the significance of impacting clinical outcomes remains unknown. Losartan appears to be a safe and efficacious agent to lower serum uric acid levels in patients with hyperuricemia. PMID:26568810

  8. Simvastatin enhances bone morphogenetic protein receptor type II expression

    SciTech Connect

    Hu Hong; Sung, Arthur; Zhao, Guohua; Shi, Lingfang; Qiu Daoming; Nishimura, Toshihiko; Kao, Peter N. . E-mail: peterkao@stanford.edu

    2006-01-06

    Statins confer therapeutic benefits in systemic and pulmonary vascular diseases. Bone morphogenetic protein (BMP) receptors serve essential signaling functions in cardiovascular development and skeletal morphogenesis. Mutations in BMP receptor type II (BMPR2) are associated with human familial and idiopathic pulmonary arterial hypertension, and pathologic neointimal proliferation of vascular endothelial and smooth muscle cells within small pulmonary arteries. In severe experimental pulmonary hypertension, simvastatin reversed disease and conferred a 100% survival advantage. Here, modulation of BMPR2 gene expression by simvastatin is characterized in human embryonic kidney (HEK) 293T, pulmonary artery smooth muscle, and lung microvascular endothelial cells (HLMVECs). A 1.4 kb BMPR2 promoter containing Egr-1 binding sites confers reporter gene activation in 293T cells which is partially inhibited by simvastatin. Simvastatin enhances steady-state BMPR2 mRNA and protein expression in HLMVEC, through posttranscriptional mRNA stabilization. Simvastatin induction of BMPR2 expression may improve BMP-BMPR2 signaling thereby enhancing endothelial differentiation and function.

  9. Homology modeling, binding site identification and docking study of human angiotensin II type I (Ang II-AT1) receptor.

    PubMed

    Vyas, Vivek K; Ghate, Manjunath; Patel, Kinjal; Qureshi, Gulamnizami; Shah, Surmil

    2015-08-01

    Ang II-AT1 receptors play an important role in mediating virtually all of the physiological actions of Ang II. Several drugs (SARTANs) are available, which can block the AT1 receptor effectively and lower the blood pressure in the patients with hypertension. Currently, there is no experimental Ang II-AT1 structure available; therefore, in this study we modeled Ang II-AT1 receptor structure using homology modeling followed by identification and characterization of binding sites and thereby assessing druggability of the receptor. Homology models were constructed using MODELLER and I-TASSER server, refined and validated using PROCHECK in which 96.9% of 318 residues were present in the favoured regions of the Ramachandran plots. Various Ang II-AT1 receptor antagonist drugs are available in the market as antihypertensive drug, so we have performed docking study with the binding site prediction algorithms to predict different binding pockets on the modeled proteins. The identification of 3D structures and binding sites for various known drugs will guide us for the structure-based drug design of novel compounds as Ang II-AT1 receptor antagonists for the treatment of hypertension. PMID:26349961

  10. Type 1 Diabetes Facts

    MedlinePlus

    ... rid of it. Whom T1D Affects Type 1 diabetes strikes both children and adults at any age. It comes on suddenly, causes ... their children might develop the disease.” — Nicky Hider, adult, New York CDC National Diabetes Statistics Report, 2014 Impreatore, et al. 2012. Diab ...

  11. Enhanced Cysteinyl-Leukotriene Type 1 Receptor Expression in T Cells from House Dust Mite-Allergic Individuals following Stimulation with Der p

    PubMed Central

    Thivierge, Maryse

    2015-01-01

    In order to determine the potential for allergen to modulate T cell expression of the CysLT1 receptor and responsiveness to leukotrienes, peripheral blood mononuclear cells from house dust mite-allergic or nonallergic individuals were incubated with D. pteronyssinus allergen (Der p). Baseline CysLT1 expression was similar in both groups of donors, but Der p significantly enhanced CysLT1 expression in CD4+ and CD8+ T cells of only allergic individuals and induced enhanced responsiveness of CD4+ T cells to LTD4 in terms of calcium mobilisation. This effect was prevented by the CysLT1 antagonist MK571. Der p also induced IL-4 and IL-10 production, and neutralizing antibody to IL-4 prevented both the enhanced CysLT1 expression and the enhanced responsiveness of T cells to LTD4 induced by Der p. In allergic individuals, Der p also induced T cell proliferation and a Th2-biased phenotype. Our data suggest that, in allergen-sensitized individuals, exposure to allergen can enhance T cell expression of CysLT1 receptors through a mechanism involving IL-4 production. This, in turn, would induce CD4+ T cell responsiveness to cysteinyl-leukotrienes and Th2 cell activation. PMID:25918735

  12. Divergent effects of corticotropin releasing hormone on endothelial cell nitric oxide synthase are associated with different expression of CRH type 1 and 2 receptors

    PubMed Central

    Cantarella, Giuseppina; Lempereur, Laurence; Lombardo, Gabriella; Chiarenza, Andrea; Pafumi, Carlo; Zappalà, Giovanna; Bernardini, Renato

    2001-01-01

    Endothelium is a target for an array of factors involved in inflammation. Endothelial cells express receptors for CRH, a neuropeptide produced during inflammation. We report both the concentration-dependent inhibitory effect of CRH upon cytokine-stimulated nitrite release by H5V murine endothelioma cells, and its stimulatory one in HUVEC cells.Western blot analysis showed that CRH inhibits cytokine-stimulated iNOS protein in H5V cells, and, instead, potentiated it in HUVEC cells.H5V cells expressed both CRH receptors (CRH-R1 and R2) mRNAs, whereas HUVEC cells expressed the CRH-R2 mRNA solely.CRH increased medium nitrites and iNOS protein expression in H5V cells pretreated with the selective CRH-R1 antagonist CP 154,526. However, the selective CRH-R2 antagonist anti-Svg-30 failed to produce similar effects. In fact, anti-Svg-30 inhibited CRH-induced increase of nitrite release and iNOS expression in HUVEC cells.Our results confirm the activating role of CRH on endothelial cells, although it suggests its possible inhibitory role in the late phase of the inflammatory response. NO-mediated effects of CRH on endothelial cells could be exploited in therapeutic strategies related to inflammatory and/or degenerative diseases. PMID:11606324

  13. Crystal Structure of Dengue Type 1 Envelope Protein in the Postfusion Conformation and its Implication for Receptor Binding, Membrane Fusion and Antibody Recognition

    SciTech Connect

    Nayak, V.; Dessau, M; Kucera, K; Anthony, K; Ledizet, M; Modis, Y

    2009-01-01

    Dengue virus relies on a conformational change in its envelope protein, E, to fuse the viral lipid membrane with the endosomal membrane and thereby deliver the viral genome into the cytosol. We have determined the crystal structure of a soluble fragment E (sE) of dengue virus type 1 (DEN-1). The protein is in the postfusion conformation even though it was not exposed to a lipid membrane or detergent. At the domain I-domain III interface, 4 polar residues form a tight cluster that is absent in other flaviviral postfusion structures. Two of these residues, His-282 and His-317, are conserved in flaviviruses and are part of the pH sensor that triggers the fusogenic conformational change in E, at the reduced pH of the endosome. In the fusion loop, Phe-108 adopts a distinct conformation, forming additional trimer contacts and filling the bowl-shaped concavity observed at the tip of the DEN-2 sE trimer.

  14. The Novel Angiotensin II Receptor Blocker Azilsartan Medoxomil Ameliorates Insulin Resistance Induced by Chronic Angiotensin II Treatment in Rat Skeletal Muscle

    PubMed Central

    Lastra, Guido; Santos, Fernando R.; Hooshmand, Payam; Hooshmand, Paria; Mugerfeld, Irina; Aroor, Annayya R.; DeMarco, Vincent G.; Sowers, James R.; Henriksen, Erik J.

    2013-01-01

    Angiotensin receptor (type 1) blockers (ARBs) can reduce both hypertension and insulin resistance induced by local and systemic activation of the renin-angiotensin-aldosterone system. The effectiveness of azilsartan medoxomil (AZIL-M), a novel imidazole-based ARB, to facilitate metabolic improvements in conditions of angiotensin II (Ang II)-associated insulin resistance is currently unknown. The aim of this study was to determine the impact of chronic AZIL-M treatment on glucose transport activity and key insulin signaling elements in red skeletal muscle of Ang II-treated rats. Male Sprague-Dawley rats were treated for 8 weeks with or without Ang II (200 ng/kg/min) combined with either vehicle or AZIL-M (1 mg/kg/day). Ang II induced significant (p < 0.05) increases in blood pressure, which were completely prevented by AZIL-M. Furthermore, Ang II reduced insulin-mediated glucose transport activity in incubated soleus muscle, and AZIL-M co-treatment increased this parameter. Moreover, AZIL-M treatment of Ang II-infused animals increased the absolute phosphorylation of insulin signaling molecules, including Akt [both Ser473 (81%) and Thr308 (23%)] and AS160 Thr642 (42%), in red gastrocnemius muscle frozen in situ. Absolute AMPKα (Thr172) phosphorylation increased (98%) by AZIL-M treatment, and relative Thr389 phosphorylation of p70 S6K1, a negative regulator of insulin signaling, decreased (51%) with AZIL-M treatment. These results indicate that ARB AZIL-M improves the in vitro insulin action on glucose transport in red soleus muscle and the functionality of the Akt/AS160 axis in red gastrocnemius muscle in situ in Ang II-induced insulin-resistant rats, with the latter modification possibly associated with enhanced AMPKα and suppressed p70 S6K1 activation. PMID:23922555

  15. Effect of gonadotropin-releasing hormone II receptor (GnRHR-II) knockdown on testosterone secretion in the boar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Unlike the classical gonadotropin-releasing hormone (GnRH-I), the second mammalian GnRH isoform (GnRH-II; His5, Trp7, Tyr8) is a poor stimulator of gonadotropin secretion. In addition, GnRH-II is ubiquitously expressed, with transcript levels highest in tissues outside of the brain. A receptor speci...

  16. Japanese cases of type 1 thanatophoric dysplasia exclusively carry a C to T transition at nucleotide 742 of the fibroblast growth factor receptor 3 gene.

    PubMed

    Pokharel, R K; Alimsardjono, H; Takeshima, Y; Nakamura, H; Naritomi, K; Hirose, S; Onishi, S; Matsuo, M

    1996-10-01

    Type I thanatophoric dysplasia (TD) is typically a lethal neonatal dwarfism, but a limited number of cases of type I TD cases survive more than one year, suggesting genetic heterogeneity. In this study, we analyzed the fibroblast growth factor receptor 3 (FGFR3) gene in 5 Japanese cases of type I TD with clinical symptoms ranging from lethal to long-survival. In every case, nucleotide sequence analysis of cDNA revealed a C to T transition at nucleotide 742 (C742T) in one allele of the FGFR3 gene, suggesting that type I TD is a rather homogeneous genetic condition, irrespective of clinical course. No association was found between C742T and C882T, although both nucleotides changes were from CpG dinucleotide in a near location. PMID:8858131

  17. Anti-tumor activity of arjunolic acid against Ehrlich Ascites Carcinoma cells in vivo and in vitro through blocking TGF-β type 1 receptor.

    PubMed

    Elsherbiny, Nehal M; Al-Gayyar, Mohammed M H

    2016-08-01

    We aimed to evaluate therapeutic potential of arjunolic acid (AA), in Terminalia Arjuna bark, on Ehrlich Ascites carcinoma (EAC) in-vivo and in-vitro. EAC was induced in fifty female Swiss albino mice. Two doses of AA was used 100 and 250mg/kg. Arjunulic acid reduced tumor volume and cells count. AA decreased EAC cells viability and increased cell toxicity. Moreover, AA reduced TNF-α, IL-1β, TGF-β, TGF-β type I receptor and latency-associated peptide levels associated with elevated IL-10 in-vivo and in-vitro. In conclusion, AA produced antitumor activity against EAC by increasing cytotoxicity and apoptosis and partially blocking the TGF-βR1 and affecting inflammatory cytokine levels. PMID:27470335

  18. The onset of labor alters corticotropin-releasing hormone type 1 receptor variant expression in human myometrium: putative role of interleukin-1beta.

    PubMed

    Markovic, Danijela; Vatish, Manu; Gu, Mei; Slater, Donna; Newton, Rob; Lehnert, Hendrik; Grammatopoulos, Dimitris K

    2007-07-01

    CRH targets the human myometrium during pregnancy. The efficiency of CRH actions is determined by expression of functional receptors (CRH-R), which are dynamically regulated. Studies in myometrial tissue biopsies using quantitative RT-PCR demonstrated that the onset of labor, term or preterm, is associated with a significant 2- to 3-fold increase in CRH-R1 mRNA levels. Detailed analysis of myometrial CRH-R1 mRNA variants showed a decline of the pro-CRH-R1 mRNA encoding the CRH-R1beta variant during labor and increased mRNA levels of CRH-R1d mRNA. Studies in myometrial cells identified IL-1beta as an important regulator of myometrial CRH-R1 gene expression because prolonged treatment of myometrial cells with IL-1beta (1 ng/ml) for 18 h induced expression of CRH-R1 mRNA levels by 1.5- to 2-fold but significantly attenuated CRH-R1beta mRNA expression by 70%. In contrast, IL-1beta had no effect on CRH-R1d mRNA expression. Studies using specific inhibitors suggest that ERK1/2, p38 MAPK, and downstream nuclear translocation of nuclear factor-kappaB mediate IL-1beta effects on myometrial CRH-R1 gene. However, the increased CRH-R1 mRNA expression was associated with a dampening of the receptor efficacy to activate the adenylyl cyclase/cAMP signaling cascade. Thus, our findings suggest that IL-1beta is an important regulator of CRH-R1 expression and functional activity, and this interaction might play a role in the transition of the uterus from quiescence to active contractions necessary for the onset of parturition. PMID:17431005

  19. Identification of the sites for CaMK-II-dependent phosphorylation of GABA(A) receptors.

    PubMed

    Houston, Catriona M; Lee, Henry H C; Hosie, Alastair M; Moss, Stephen J; Smart, Trevor G

    2007-06-15

    Phosphorylation can affect both the function and trafficking of GABA(A) receptors with significant consequences for neuronal excitability. Serine/threonine kinases can phosphorylate the intracellular loops between M3-4 of GABA(A) receptor beta and gamma subunits thereby modulating receptor function in heterologous expression systems and in neurons (1, 2). Specifically, CaMK-II has been demonstrated to phosphorylate the M3-4 loop of GABA(A) receptor subunits expressed as GST fusion proteins (3, 4). It also increases the amplitude of GABA(A) receptor-mediated currents in a number of neuronal cell types (5-7). To identify which substrate sites CaMK-II might phosphorylate and the consequent functional effects, we expressed recombinant GABA(A) receptors in NG108-15 cells, which have previously been shown to support CaMK-II modulation of GABA(A) receptors containing the beta3 subunit (8). We now demonstrate that CaMK-II mediates its effects on alpha1beta3 receptors via phosphorylation of Ser(383) within the M3-4 domain of the beta subunit. Ablation of beta3 subunit phosphorylation sites for CaMK-II revealed that for alphabetagamma receptors, CaMK-II has a residual effect on GABA currents that is not mediated by previously identified sites of CaMK-II phosphorylation. This residual effect is abolished by mutation of tyrosine phosphorylation sites, Tyr(365) and Tyr(367), on the gamma2S subunit, and by the tyrosine kinase inhibitor genistein. These results suggested that CaMK-II is capable of directly phosphorylating GABA(A) receptors and activating endogenous tyrosine kinases to phosphorylate the gamma2 subunit in NG108-15 cells. These findings were confirmed in a neuronal environment by expressing recombinant GABA(A) receptors in cerebellar granule neurons. PMID:17442679

  20. A seven-transmembrane domain receptor involved in fusion and entry of T-cell-tropic human immunodeficiency virus type 1 strains.

    PubMed Central

    Berson, J F; Long, D; Doranz, B J; Rucker, J; Jirik, F R; Doms, R W

    1996-01-01

    Entry of human immunodeficiency virus type 1 (HIV-1) into cells requires binding to CD4 and fusion with a cellular membrane. Fusion does not occur in most nonhuman cells even when they express human CD4, indicating that one or more human accessory factors are required for virus infection. Recently, a seven-transmembrane domain protein has been shown to serve as an accessory factor for T-cell-tropic (T-tropic) HIV-1 isolates (Y. Feng, C. C. Broder, P. E. Kennedy, and E. A. Berger, Science 272:872-877, 1996). Here we show that expression of this glycoprotein, termed fusin, in murine, feline, simian, and quail cell lines, in conjunction with human CD4, rendered these cells fully permissive for HIV-1 envelope glycoprotein (Env)-mediated membrane fusion. Expression of CD4 or fusin alone did not permit fusion. In addition, introduction of fusin and CD4 into a human cell line, U87MG, that is resistant to HIV-1 induced syncytium formation and to infection by HIV-1 when expressing CD4 alone made this cell line permissive for Env-mediated cell-cell fusion. Fusion was observed only with T-tropic Env proteins. Macrophage-tropic (M-tropic) Env proteins from the SF162, ADA, and Ba-L HIV-1 strains did not fuse with cells expressing fusin and CD4, suggesting that M-tropic viruses utilize an accessory molecule other than fusin. Finally, coexpression of fusin and CD4 made both a murine and feline cell line susceptible to virus infection by T-tropic, but not M-tropic, HIV-1 strains. PMID:8709256

  1. Vascular oxidative stress upregulates angiotensin II type I receptors via mechanisms involving nuclear factor kappa B.

    PubMed

    Bhatt, Siddhartha R; Lokhandwala, Mustafa F; Banday, Anees Ahmad

    2014-01-01

    Abstract The association of oxidative stress with hypertension is well known. However, a causal role of oxidative stress in hypertension is unclear. Vascular angiotensin II type 1 receptor (AT1R) upregulation is a prominent contributor to pathogenesis of hypertension. However, the mechanisms causing this upregulation are unknown. Oxidative stress is an important regulator of protein expression via activation of transcription factors such as nuclear factor kappa B (NFκB). The present study was carried out to test the hypothesis that oxidative stress contributes to vascular AT1R upregulation via NFκB in human aortic smooth muscle cells (HASMC) and spontaneously hypertensive rats (SHR). HASMC exposed to oxidative stress exhibited a robust increase in AT1R mRNA in HASMC. Furthermore, oxidative stress failed to upregulate AT1Rs in the presence of either an antioxidant catalase or siRNA against p65 subunit of NFκB. To test the role of oxidative stress and NFκB in hypertension, prehypertensive SHR were treated with NFκB inhibitor pyrrolidine dithiocarbamate from 5 weeks to 11-12 weeks of age. At 11-12 weeks of age, SHR exhibited increased NFκB expression, AT1R upregulation and exaggerated Ang II-induced vasoconstriction as compared to age-matched Wistar Kyoto (WKY) rats. PDTC treatment of SHR lowered NFκB expression, normalized AT1R expression and Ang II-induced vasoconstriction. More importantly, PDTC treatment significantly attenuated hypertension development in SHR. In conclusion, vascular oxidative can upregulate AT1R, via mechanisms involving NFκB, and contribute to the development of hypertension. PMID:25198883

  2. Inclusion of Strep-Tag II in design of antigen receptors for T cell immunotherapy

    PubMed Central

    Liu, Lingfeng; Sommermeyer, Daniel; Cabanov, Alexandra; Kosasih, Paula; Hill, Tyler; Riddell, Stanley R

    2016-01-01

    The tactical introduction of Strep-tag II into synthetic antigen receptors provides engineered T cells with a marker for identification and rapid purification, and a functional element for selective antibody coated microbead-driven large-scale expansion. Such receptor designs can be applied to chimeric antigen receptors of different ligand specificities and costimulatory domains, and to T cell receptors to facilitate cGMP manufacturing of adoptive T cell therapies to treat cancer and other diseases. PMID:26900664

  3. The Involvement of Angiotensin Type 1 and Type 2 Receptors in Estrogen-Induced Cell Proliferation and Vascular Endothelial Growth Factor Expression in the Rat Anterior Pituitary

    PubMed Central

    Lawnicka, Hanna; Ptasinska-Wnuk, Dorota; Mucha, Slawomir; Kunert-Radek, Jolanta; Pawlikowski, Marek; Stepien, Henryk

    2012-01-01

    The aim of our study was to examine the involvement of renin-angiotensin system (RAS) in estrogen-induced lactotropes proliferation and vascular endothelial growth factor (VEGF) expression in rat pituitary. The study was performed on Fisher 344 rats underwent 8-day treatment with diethylstilboestrol (DES). The proliferation index (PCNA) and VEGF expression in pituitary sections were estimated using immunohistochemical methods. Treatment with DES increased the number of PCNA-positive cells, VEGF-positive cells, and VEGF-positive blood vessels in pituitary. Stimulatory effect of estrogen on cell proliferation and VEGF expression in blood vessels was attenuated by losartan, PD123319, and captopril. VEGF immunoreactivity in pituitary cells of DES-treated rats was decreased by AT1 antagonist and not changed by AT2 blocker and ACE inhibitor. Our findings suggest the involvement of RAS in DES-induced cell proliferation and VEGF expression in pituitary. Both the AT1 and AT2 receptors appear to mediate the estrogen-dependent mitogenic and proangiogenic effects in rat pituitary. PMID:22645419

  4. A Polymorphism in the Regulatory Region of the CC-Chemokine Receptor 5 Gene Influences Perinatal Transmission of Human Immunodeficiency Virus Type 1 to African-American Infants

    PubMed Central

    Kostrikis, Leondios G.; Neumann, Avidan U.; Thomson, Bruce; Korber, Bette T.; McHardy, Paul; Karanicolas, Rose; Deutsch, Lisa; Huang, Yaoxing; Lew, Judy F.; McIntosh, Kenneth; Pollack, Henry; Borkowsky, William; Spiegel, Hans M. L.; Palumbo, Paul; Oleske, James; Bardeguez, Arlene; Luzuriaga, Katherine; Sullivan, John; Wolinsky, Steven M.; Koup, Richard A.; Ho, David D.; Moore, John P.

    1999-01-01

    There are natural mutations in the coding and noncoding regions of the human immunodeficiency virus type 1 (HIV-1) CC-chemokine coreceptor 5 (CCR5) and in the related CCR2 protein (the CCR2-64I mutation). Individuals homozygous for the CCR5-Δ32 allele, which prevents CCR5 expression, strongly resist HIV-1 infection. Several genetic polymorphisms have been identified within the CCR5 5′ regulatory region, some of which influence the rate of disease progression in adult AIDS study cohorts. We genotyped 1,442 infants (1,235 uninfected and 207 HIV-1 infected) for five CCR5 and CCR2 polymorphisms: CCR5-59353-T/C, CCR5-59356-C/T CCR5-59402-A/G, CCR5-Δ32, and CCR2-64I. The clinical significance of each genotype was assessed by measuring whether it influenced the rate of perinatal HIV-1 transmission among 667 AZT-untreated mother-infant pairs (554 uninfected and 113 HIV-1 infected). We found that the mutant CCR5-59356-T allele is relatively common in African-Americans (20.6% allele frequency among 552 infants) and rare in Caucasians and Hispanics (3.4 and 5.6% of 174 and 458 infants, respectively; P < 0.001). There were 38 infants homozygous for CCR5-59356-T, of whom 35 were African-Americans. Among the African-American infants in the AZT-untreated group, there was a highly significant increase in HIV-1 transmission to infants with two mutant CCR5-59356-T alleles (47.6% of 21), compared to those with no or one mutant allele (13.4 to 14.1% of 187 and 71, respectively; P < 0.001). The increased relative risk was 5.9 (95% confidence interval, 2.3 to 15.3; P < 0.001). The frequency of the CCR5-59356-T mutation varies between population groups in the United States, a low frequency occurring in Caucasians and a higher frequency occurring in African-Americans. Homozygosity for CCR5-59356-T is strongly associated with an increased rate of perinatal HIV-1 transmission. PMID:10559343

  5. ACTH-independent macronodular adrenocortical hyperplasia reveals prevalent aberrant in vivo and in vitro responses to hormonal stimuli and coupling of arginine-vasopressin type 1a receptor to 11β-hydroxylase

    PubMed Central

    2013-01-01

    Background Adrenal Cushing’s syndrome caused by ACTH-independent macronodular adrenocortical hyperplasia (AIMAH) can be accompanied by aberrant responses to hormonal stimuli. We investigated the prevalence of adrenocortical reactions to these stimuli in a large cohort of AIMAH patients, both in vivo and in vitro. Methods In vivo cortisol responses to hormonal stimuli were studied in 35 patients with ACTH-independent bilateral adrenal enlargement and (sub-)clinical hypercortisolism. In vitro, the effects of these stimuli on cortisol secretion and steroidogenic enzyme mRNA expression were evaluated in cultured AIMAH and other adrenocortical cells. Arginine-vasopressin (AVP) receptor mRNA levels were determined in the adrenal tissues. Results Positive serum cortisol responses to stimuli were detected in 27/35 AIMAH patients tested, with multiple responses within individual patients occurring for up to four stimuli. AVP and metoclopramide were the most prevalent hormonal stimuli triggering positive responses in vivo. Catecholamines induced short-term cortisol production more often in AIMAH cultures compared to other adrenal cells. Short- and long-term incubation with AVP increased cortisol secretion in cultures of AIMAH cells. AVP also increased steroidogenic enzyme mRNA expression, among which an aberrant induction of CYP11B1. AVP type 1a receptor was the only AVPR expressed and levels were high in the AIMAH tissues. AVPR1A expression was related to the AVP-induced stimulation of CYP11B1. Conclusions Multiple hormonal signals can simultaneously induce hypercortisolism in AIMAH. AVP is the most prevalent eutopic signal and expression of its type 1a receptor was aberrantly linked to CYP11B1 expression. PMID:24034279

  6. Mosaic neurofibromatosis type 1.

    PubMed

    Liang, Christine; Schaffer, Julie V

    2008-01-01

    A 24-year-old man presented with numerous lentigines and multiple cafe-au-lait macules on both sides of the face, neck, and trunk as well as on the proximal area of the upper extremities and in the axillae. The pigmented lesions had a Blaschko-linear distribution on the upper trunk and were limited to the left side of the abdomen, with a sharp demarcation at the midline. Multiple, cutaneous neurofibromas were found on the trunk, and ophthalmologic examination showed a Lisch nodule in the left iris. The clinical findings and their widespread but segmental distribution were consistent with a diagnosis of mosaic neurofibromatosis type 1. PMID:18627742

  7. Loss of inhibition by brain natriuretic peptide over P2X3 receptors contributes to enhanced spike firing of trigeminal ganglion neurons in a mouse model of familial hemiplegic migraine type-1.

    PubMed

    Marchenkova, Anna; van den Maagdenberg, Arn M J M; Nistri, Andrea

    2016-09-01

    Purinergic P2X3 receptors (P2X3Rs) play an important role in pain pathologies, including migraine. In trigeminal neurons, P2X3Rs are constitutively downregulated by endogenous brain natriuretic peptide (BNP). In a mouse knock-in (KI) model of familial hemiplegic migraine type-1 with upregulated calcium CaV2.1 channel function, trigeminal neurons exhibit hyperexcitability with gain-of-function of P2X3Rs and their deficient BNP-mediated inhibition. We studied whether the absent BNP-induced control over P2X3Rs activity in KI cultures may be functionally expressed in altered firing activity of KI trigeminal neurons. Patch-clamp experiments investigated the excitability of wild-type and KI trigeminal neurons induced by either current or agonists for P2X3Rs or transient receptor potential vanilloid-1 (TRPV1) receptors. Consistent with the constitutive inhibition of P2X3Rs by BNP, sustained pharmacological block of BNP receptors selectively enhanced P2X3R-mediated excitability of wild-type neurons without affecting firing evoked by the other protocols. This effect included increased number of action potentials, lower spike threshold and shift of the firing pattern distribution toward higher spiking activity. Thus, inactivation of BNP signaling transformed the wild-type excitability phenotype into the one typical for KI. BNP receptor block did not influence excitability of KI neurons in accordance with the lack of BNP-induced P2X3R modulation. Our study suggests that, in wild-type trigeminal neurons, negative control over P2X3Rs by the BNP pathway is translated into tonic suppression of P2X3Rs-mediated excitability. Lack of this inhibition in KI cultures results in a hyperexcitability phenotype and might contribute to facilitated trigeminal pain transduction relevant for migraine. PMID:27346147

  8. Chromatographic resolution of angiotensin II receptor antagonists (sartans).

    PubMed

    Tahir, Muhammad Saqlain; Adnan, Ahmad; Syed, Quratulain

    2016-08-01

    First time a simple, sensitive and unified quantification method has been developed to analyze the complete class of angiotensin II receptor antagonists which are used in the treatment of hypertension either alone or in combination with some other drugs. The most important advantage of developed method was that the eight separate drugs can be determined on a single chromatographic system without modifications in detection wavelength and mobile phase. The drugs were separated on a Purospher Star 4.6mm×25cm, 5μm, C18 column maintained at 40°C with 1mLmin(-1) flow rate using ultra violet detection at 254nm. Good separation (Rs>2.0) was achieved in a short analysis allowing simultaneous determination of all eight sartans. The effect of variation in flow rate, detection wavelength and column oven temperature was also studied. The proposed method was statistically validated in terms of precision, accuracy, linearity, specificity and robustness. The newly developed method proved to be specific, robust and accurate for the quantification of eight sartans in commercial pharmaceutical formulations. PMID:27258943

  9. Blockade of Urotensin II Receptor Prevents Vascular Dysfunction

    PubMed Central

    Kim, Young-Ae; Lee, Dong Gil; Yi, Kyu Yang; Lee, Byung Ho; Jung, Yi-Sook

    2016-01-01

    Urotensin II (UII) is a potent vasoactive peptide and mitogenic agent to induce proliferation of various cells including vascular smooth muscle cells (VSMCs). In this study, we examined the effects of a novel UII receptor (UT) antagonist, KR-36676, on vasoconstriction of aorta and proliferation of aortic SMCs. In rat aorta, UII-induced vasoconstriction was significantly inhibited by KR-36676 in a concentration-dependent manner. In primary human aortic SMCs (hAoSMCs), UII-induced cell proliferation was significantly inhibited by KR-36676 in a concentration-dependent manner. In addition, KR-36676 decreased UII-induced phosphorylation of ERK, and UII-induced cell proliferation was also significantly inhibited by a known ERK inhibitor U0126. In mouse carotid ligation model, intimal thickening of carotid artery was dramatically suppressed by oral treatment with KR-36676 (30 mg/ kg/day) for 4 weeks compared to vehicle-treated group. From these results, it is indicated that KR-36676 suppress UII-induced proliferation of VSMCs at least partially through inhibition of ERK activation, and that it also attenuates UII-induced vasoconstriction and vascular neointima formation. Our study suggest that KR-36676 may be an attractive candidate for the pharmacological management of vascular dysfunction. PMID:27582556

  10. Blockade of Urotensin II Receptor Prevents Vascular Dysfunction.

    PubMed

    Kim, Young-Ae; Lee, Dong Gil; Yi, Kyu Yang; Lee, Byung Ho; Jung, Yi-Sook

    2016-09-01

    Urotensin II (UII) is a potent vasoactive peptide and mitogenic agent to induce proliferation of various cells including vascular smooth muscle cells (VSMCs). In this study, we examined the effects of a novel UII receptor (UT) antagonist, KR-36676, on vasoconstriction of aorta and proliferation of aortic SMCs. In rat aorta, UII-induced vasoconstriction was significantly inhibited by KR-36676 in a concentration-dependent manner. In primary human aortic SMCs (hAoSMCs), UII-induced cell proliferation was significantly inhibited by KR-36676 in a concentration-dependent manner. In addition, KR-36676 decreased UII-induced phosphorylation of ERK, and UII-induced cell proliferation was also significantly inhibited by a known ERK inhibitor U0126. In mouse carotid ligation model, intimal thickening of carotid artery was dramatically suppressed by oral treatment with KR-36676 (30 mg/ kg/day) for 4 weeks compared to vehicle-treated group. From these results, it is indicated that KR-36676 suppress UII-induced proliferation of VSMCs at least partially through inhibition of ERK activation, and that it also attenuates UII-induced vasoconstriction and vascular neointima formation. Our study suggest that KR-36676 may be an attractive candidate for the pharmacological management of vascular dysfunction. PMID:27582556

  11. Functional role of residues corresponding to helical domain II (amino acids 35 to 46) of human immunodeficiency virus type 1 Vpr.

    PubMed

    Singh, S P; Tomkowicz, B; Lai, D; Cartas, M; Mahalingam, S; Kalyanaraman, V S; Murali, R; Srinivasan, A

    2000-11-01

    Vpr, encoded by the human immunodeficiency virus type 1 genome, contains 96 amino acids and is a multifunctional protein with features which include cell cycle arrest at G(2), nuclear localization, participation in transport of the preintegration complex, cation channel activity, oligomerization, and interaction with cellular proteins, in addition to its incorporation into the virus particles. Recently, structural studies based on nuclear magnetic resonance and circular dichroism spectroscopy showed that Vpr contains a helix (HI)-turn-helix (HII) core at the amino terminus and an amphipathic helix (HIII) in the middle region. Though the importance of helical domains HI and HIII has been defined with respect to Vpr functions, the role of helical domain HII is not known. To address this issue, we constructed a series of mutants in which the HII domain was altered by deletion, insertion, and/or substitution mutagenesis. To enable the detection of Vpr, the sequence corresponding to the Flag epitope (DYKDDDDK) was added, in frame, to the Vpr coding sequences. Mutants, expressed through the in vitro transcription/translation system and in cells, showed an altered migration corresponding to deletions in Vpr. Substitution mutational analysis of residues in HII showed reduced stability for VprW38S-FL, VprL42G-FL, and VprH45W-FL. An assay involving cotransfection of NLDeltaVpr proviral DNA and a Vpr expression plasmid was employed to analyze the virion incorporation property of Vpr. Mutant Vpr containing deletions and specific substitutions (VprW38S-FL, VprL39G-FL, VprL42G-FL, VprG43P-FL, and VprI46G-FL) exhibited a negative virion incorporation phenotype. Further, mutant Vpr-FL containing deletions also failed to associate with wild-type Vpr, indicating a possible defect in the oligomerization feature of Vpr. Subcellular localization studies indicated that mutants VprDelta35-50-H-FL, VprR36W-FL, VprL39G-FL, and VprI46G-FL exhibited both cytoplasmic and nuclear localization

  12. Functional Role of Residues Corresponding to Helical Domain II (Amino Acids 35 to 46) of Human Immunodeficiency Virus Type 1 Vpr

    PubMed Central

    Singh, Satya P.; Tomkowicz, Brian; Lai, Derhsing; Cartas, Maria; Mahalingam, Sundarasamy; Kalyanaraman, Vaniambadi S.; Murali, Ramachandran; Srinivasan, Alagarsamy

    2000-01-01

    Vpr, encoded by the human immunodeficiency virus type 1 genome, contains 96 amino acids and is a multifunctional protein with features which include cell cycle arrest at G2, nuclear localization, participation in transport of the preintegration complex, cation channel activity, oligomerization, and interaction with cellular proteins, in addition to its incorporation into the virus particles. Recently, structural studies based on nuclear magnetic resonance and circular dichroism spectroscopy showed that Vpr contains a helix (HI)-turn-helix (HII) core at the amino terminus and an amphipathic helix (HIII) in the middle region. Though the importance of helical domains HI and HIII has been defined with respect to Vpr functions, the role of helical domain HII is not known. To address this issue, we constructed a series of mutants in which the HII domain was altered by deletion, insertion, and/or substitution mutagenesis. To enable the detection of Vpr, the sequence corresponding to the Flag epitope (DYKDDDDK) was added, in frame, to the Vpr coding sequences. Mutants, expressed through the in vitro transcription/translation system and in cells, showed an altered migration corresponding to deletions in Vpr. Substitution mutational analysis of residues in HII showed reduced stability for VprW38S-FL, VprL42G-FL, and VprH45W-FL. An assay involving cotransfection of NLΔVpr proviral DNA and a Vpr expression plasmid was employed to analyze the virion incorporation property of Vpr. Mutant Vpr containing deletions and specific substitutions (VprW38S-FL, VprL39G-FL, VprL42G-FL, VprG43P-FL, and VprI46G-FL) exhibited a negative virion incorporation phenotype. Further, mutant Vpr-FL containing deletions also failed to associate with wild-type Vpr, indicating a possible defect in the oligomerization feature of Vpr. Subcellular localization studies indicated that mutants VprΔ35-50-H-FL, VprR36W-FL, VprL39G-FL, and VprI46G-FL exhibited both cytoplasmic and nuclear localization, unlike

  13. Overexpression of angiotensin II type I receptor in cardiomyocytes induces cardiac hypertrophy and remodeling

    PubMed Central

    Paradis, Pierre; Dali-Youcef, Nassim; Paradis, François W.; Thibault, Gaétan; Nemer, Mona

    2000-01-01

    Angiotensin II (AII) is a major determinant of arterial pressure and volume homeostasis, mainly because of its vascular action via the AII type 1 receptor (AT1R). AII has also been implicated in the development of cardiac hypertrophy because angiotensin I-converting enzyme inhibitors and AT1R antagonists prevent or regress ventricular hypertrophy in animal models and in human. However, because these treatments impede the action of AII at cardiac as well as vascular levels, and reduce blood pressure, it has been difficult to determine whether AII action on the heart is direct or a consequence of pressure-overload. To determine whether AII can induce cardiac hypertrophy directly via myocardial AT1R in the absence of vascular changes, transgenic mice overexpressing the human AT1R under the control of the mouse α-myosin heavy chain promoter were generated. Cardiomyocyte-specific overexpression of AT1R induced, in basal conditions, morphologic changes of myocytes and nonmyocytes that mimic those observed during the development of cardiac hypertrophy in human and in other mammals. These mice displayed significant cardiac hypertrophy and remodeling with increased expression of ventricular atrial natriuretic factor and interstitial collagen deposition and died prematurely of heart failure. Neither the systolic blood pressure nor the heart rate were changed. The data demonstrate a direct myocardial role for AII in the development of cardiac hypertrophy and failure and provide a useful model to elucidate the mechanisms of action of AII in the pathogenesis of cardiac diseases. PMID:10639182

  14. Overexpression of angiotensin II type I receptor in cardiomyocytes induces cardiac hypertrophy and remodeling.

    PubMed

    Paradis, P; Dali-Youcef, N; Paradis, F W; Thibault, G; Nemer, M

    2000-01-18

    Angiotensin II (AII) is a major determinant of arterial pressure and volume homeostasis, mainly because of its vascular action via the AII type 1 receptor (AT1R). AII has also been implicated in the development of cardiac hypertrophy because angiotensin I-converting enzyme inhibitors and AT1R antagonists prevent or regress ventricular hypertrophy in animal models and in human. However, because these treatments impede the action of AII at cardiac as well as vascular levels, and reduce blood pressure, it has been difficult to determine whether AII action on the heart is direct or a consequence of pressure-overload. To determine whether AII can induce cardiac hypertrophy directly via myocardial AT1R in the absence of vascular changes, transgenic mice overexpressing the human AT1R under the control of the mouse alpha-myosin heavy chain promoter were generated. Cardiomyocyte-specific overexpression of AT1R induced, in basal conditions, morphologic changes of myocytes and nonmyocytes that mimic those observed during the development of cardiac hypertrophy in human and in other mammals. These mice displayed significant cardiac hypertrophy and remodeling with increased expression of ventricular atrial natriuretic factor and interstitial collagen deposition and died prematurely of heart failure. Neither the systolic blood pressure nor the heart rate were changed. The data demonstrate a direct myocardial role for AII in the development of cardiac hypertrophy and failure and provide a useful model to elucidate the mechanisms of action of AII in the pathogenesis of cardiac diseases. PMID:10639182

  15. Differential regulation of angiotensin converting enzyme 2 and nuclear factor-κB by angiotensin II receptor subtypes in type 2 diabetic kidney.

    PubMed

    Pandey, Anuradha; Goru, Santosh Kumar; Kadakol, Almesh; Malek, Vajir; Gaikwad, Anil Bhanudas

    2015-11-01

    Angiotensin II (Ang II) acts through Angiotensin Converting Enzyme (ACE)/Ang II type 1 receptor (AT1R) axis to promote renal failure whereas the Ang II type 2 receptor (AT2R)/Angiotensin Converting Enzyme 2 (ACE2)/Ang1-7/Mas axis constitutes the protective arm of Renin Angiotensin System (RAS). Though Ang II has been known to activate the Nuclear Factor-κB (NF-κB) signalling pathway through different receptor subtype(s) in different tissues under various diseases, the subtype orchestrating this stimulation in type 2 diabetic kidney remains elusive. ACE2, a protective monocarboxypeptidase, responsible for conversion of Ang II to Ang1-7, opposes the deleterious effects of RAS pathway but how its expression is altered with blockade of AT1R and AT2R is not yet known. Hence, the present study was conceived to understand the regulation of NF-κB and ACE2 by using specific AT1 and AT2 receptor antagonists in non-genetic model of type 2 diabetic nephropathy. Our results show that the AT1R and AT2R antagonists lead to the repression and activation of NF-κB signalling pathway, respectively which suggests the role of AT1R in NF-κB activation. The blockade of AT2R led to an increase in ACE2 expression, which may be a compensatory response to the drastically increased inflammatory mediators and oxidative stress in the diabetic kidney. To the best of our knowledge, this is the first study showing the differential regulation of NF-κB and ACE2 by Ang II receptor subtypes and thus this study improves our understanding regarding regulation of inflammatory cascade and ACE2 by AT1R and AT2R in type 2 diabetic kidney, which may help in designing novel strategies to combat the disease in future. PMID:26271886

  16. The Structural Basis for Class II Cytokine Receptor Recognition by JAK1.

    PubMed

    Ferrao, Ryan; Wallweber, Heidi J A; Ho, Hoangdung; Tam, Christine; Franke, Yvonne; Quinn, John; Lupardus, Patrick J

    2016-06-01

    JAK1 is a member of the Janus kinase (JAK) family of non-receptor tyrosine kinases that are activated in response to cytokines and interferons. Here, we present two crystal structures of the human JAK1 FERM and SH2 domains bound to peptides derived from the class II cytokine receptors IFN-λ receptor 1 and IL-10 receptor 1 (IFNLR1 and IL10RA). These structures reveal an interaction site in the JAK1 FERM that accommodates the so-called "box1" membrane-proximal receptor peptide motif. Biophysical analysis of the JAK1-IFNLR1 interaction indicates that the receptor box1 is the primary driver of the JAK1 interaction, and identifies residues conserved among class II receptors as important for binding. In addition, we demonstrate that a second "box2" receptor motif further stabilizes the JAK1-IFNLR1 complex. Together, these data identify a conserved JAK binding site for receptor peptides and elucidate the mechanism by which class II cytokine receptors interact with JAK1. PMID:27133025

  17. Calix receptor edifice; scrupulous turn off fluorescent sensor for Fe(III), Co(II) and Cu(II).

    PubMed

    Bhatt, Keyur D; Gupte, Hrishikesh S; Makwana, Bharat A; Vyas, Disha J; Maity, Debdeep; Jain, Vinod K

    2012-11-01

    Novel Supramolecular fluorescence receptor derived from calix-system i.e. calix[4]resorcinarene bearing dansylchloride as fluorophore was designed and synthesized. The compound was purified by column chromatography and characterized by elemental analysis, NMR and Mass spectroscopy. Tetradansylated calix[4] resorcinarene (TDCR) shows a boat conformation with C(2)v symmetry. The complexation behaviour of metal cations [Ag(I), Cd(II), Co(II), Fe(III), Hg(II), Cu(II), Pb(II), Zn(II), U(VI) (1 × 10(-4) M)] with tetra dansylated calix[4]resorcinarene (1 × 10(-6) M) was studied by spectophotometry and spectrofluorometry. Red shift in the absorption spectra led us to conclude that there is strong complexation Fe(III), Co(II) and Cu(II) with TDCR. These metal cations also produce quenching with red shifts in the emission spectra. The maximum quenching in emission intensity was observed in the case of Fe(III) and its binding constant was also found to be significantly higher than that of Co(II) and Cu(II). Quantum yield of metal complexes of Fe(III) was found to be lower in comparison with Co(II) and Cu(II) complexes. Stern Volmer analysis indicates that the mechanism of fluorescence quenching is either purely dynamic, or purely static. PMID:22739703

  18. Quantitative autoradiography of angiotensin II receptors in brain and kidney: focus on cardiovascular implications

    SciTech Connect

    Gehlert, D.R.; Speth, R.C.; Wamsley, J.K.

    1985-01-01

    Quantitative techniques of receptor autoradiography have been applied to localize (/sup 125/I)-angiotensin II binding sites in brain and kidney. High densities of autoradiographic grains, indicating the presence of angiotensin II receptors, have been localized to several rat brain nuclei including the dorsal motor nucleus of the vagus, nucleus of the solitary tract, anterior pituitary, locus coeruleus and several hypothalamic nuclei. Cat thoracic spinal cord exhibited a high density of sites over the intermedio-lateral cell column. In sections of rat kidney, angiotensin II receptors were detected in the glomerulus, vasa recta and ureter. The cardiovascular implications of these results are apparent and relate angiotensin II to hypertensive mechanisms. Thus, angiotensin II represents an endocoid which is involved in control of blood pressure through its effects on peripheral organs as well as the central nervous system.

  19. Glutaric Acidemia Type 1

    PubMed Central

    Hedlund, Gary L.; Longo, Nicola; Pasquali, Marzia

    2008-01-01

    Glutaric acidemias comprise different disorders resulting in an increased urinary excretion of glutaric acid. Glutaric acidemia type 1 (GA-1) is an autosomal recessive disorder of lysine, hydroxylysine, and tryptophan metabolism caused by deficiency of glutaryl-CoA dehydrogenase. It results in the accumulation of 3-hydroxyglutaric and glutaric acid. Affected patients can present with brain atrophy and macrocephaly and with acute dystonia secondary to striatal degeneration in most cases triggered by an intercurrent childhood infection with fever between 6 and 18 months of age. This disorder can be identified by increased glutaryl (C5DC) carnitine on newborn screening. Urine organic acid analysis indicates the presence of excess 3-OH-glutaric acid, and urine acylcarnitine profile shows glutaryl carnitine as the major peak. Therapy consists in carnitine supplementation to remove glutaric acid, a diet restricted in amino acids capable of producing glutaric acid, and prompt treatment of intercurrent illnesses. Early diagnosis and therapy reduce the risk of acute dystonia in patients with GA-1. PMID:16602100

  20. Changes in angiotensin II receptor bindings in the hen neurohypophysis before and after oviposition.

    PubMed

    Takahashi, T; Nozaki, Y; Nakagawa-Mizuyachi, K; Nakayama, H; Kawashima, M

    2011-11-01

    The present study was performed to elucidate whether the angiotensin II (ANG II) receptor exists in the plasma membrane fraction of the neurohypophysis in hens, to estimate the time of action of ANG II on the neurohypophysis before and after oviposition, and to examine relationships between the action of ANG II on the neurohypophysis and those of estrogen and prostaglandin F(2α) (PGF(2α)) in relation to arginine vasotocin (AVT) release. The specific binding had a binding specificity to chicken ANG II (cANG II), reversibility, and saturation in the [(125)I]cANG II binding assay. Scatchard analysis revealed that the binding sites are of a single class. The equilibrium dissociation constant (K(d)) obtained by kinetic analysis and Scatchard analysis suggested a high affinity, and the maximum binding capacity (B(max)) obtained by Scatchard analysis suggested a limited capacity. These results suggest that an ANG II receptor exists in the neurohypophysis of hens. The K(d) and the B(max) value was significantly smaller in laying hens than in nonlaying hens, which suggests that bindings of the cANG II receptor change, depending on the difference in laying condition. Values of the K(d) and the B(max) decreased approximately 15 min before oviposition in laying hens, and decreased 1 h after an intramuscular injection of estradiol-17β and 5 min after an intravenous injection of cANG II in nonlaying hens. The amount of specific binding of PGF(2α) receptor in the neurohypophysis also decreased and AVT concentration in blood increased after the cANG II injection. It seems likely that the action of cANG II in the neurohypophysis increases due to the effect of estrogen approximately 15 min before oviposition, and the cANG II action stimulates AVT release through the increase in the PGF(2α) action in this tissue. PMID:22010242

  1. Group II Metabotropic Glutamate Receptor Agonist LY379268 Regulates AMPA Receptor Trafficking in Prefrontal Cortical Neurons

    PubMed Central

    Wang, Min-Juan; Li, Yan-Chun; Snyder, Melissa A.; Wang, Huaixing; Li, Feng; Gao, Wen-Jun

    2013-01-01

    Group II metabotropic glutamate receptor (mGluR) agonists have emerged as potential treatment drugs for schizophrenia and other neurological disorders, whereas the mechanisms involved remain elusive. Here we examined the effects of LY379268 (LY37) on the expression and trafficking of the α-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptor subunits GluA1 and GluA2 in prefrontal neurons. We show that LY37 significantly increased the surface and total expression of both GluA1 and GluA2 subunits in cultured prefrontal neurons and in vivo. This effect was mimicked by the selective mGluR2 agonist LY395756 and was blocked by mGluR2/3 antagonist LY341495. Moreover, we found that both GluA1 and GluA2 subunits were colocalized with PSD95 but not synapsin I, suggesting a postsynaptic localization. Consistently, treatment with LY37 significantly increased the amplitude, but not frequency, of miniature excitatory postsynaptic currents. Further, actinomycin-D blocked LY37's effects, suggesting a transcriptional regulation. In addition, application of glycogen synthase kinase-3beta (GSK-3β) inhibitor completely blocked LY37's effect on GluA2 surface expression, whereas GSK-3β inhibitor itself induced decreases in the surface and total protein levels of GluA1, but not GluA2 subunits. This suggests that GSK-3β differentially mediates GluA1 and GluA2 trafficking. Further, LY37 significantly increased the phosphorylation, but not total protein, of extracellular signal-regulated kinase 1/2 (ERK1/2). Neither ERK1/2 inhibitor PD98059 alone nor PD98059 combined with LY37 treatment induced changes in GluA1 or GluA2 surface expression or total protein levels. Our data thus suggest that mGluR2/3 agonist regulates postsynaptic AMPA receptors by affecting the synaptic trafficking of both GluA1 and GluA2 subunits and that the regulation is likely through ERK1/2 signaling in GluA1 and/or both ERK1/2 and GSK-3β signaling pathways in the GluA2 subunit. PMID:23593498

  2. Angiotensin II (AT(1)) receptor blockade reduces vascular tissue factor in angiotensin II-induced cardiac vasculopathy.

    PubMed

    Müller, D N; Mervaala, E M; Dechend, R; Fiebeler, A; Park, J K; Schmidt, F; Theuer, J; Breu, V; Mackman, N; Luther, T; Schneider, W; Gulba, D; Ganten, D; Haller, H; Luft, F C

    2000-07-01

    Tissue factor (TF), a main initiator of clotting, is up-regulated in vasculopathy. We tested the hypothesis that chronic in vivo angiotensin (ANG) II receptor AT(1) receptor blockade inhibits TF expression in a model of ANG II-induced cardiac vasculopathy. Furthermore, we explored the mechanisms by examining transcription factor activation and analyzing the TF promoter. Untreated transgenic rats overexpressing the human renin and angiotensinogen genes (dTGR) feature hypertension and severe left ventricular hypertrophy with focal areas of necrosis, and die at age 7 weeks. Plasma and cardiac ANG II was three- to fivefold increased compared to Sprague-Dawley rats. Chronic treatment with valsartan normalized blood pressure and coronary resistance completely, and ameliorated cardiac hypertrophy (P < 0.001). Valsartan prevented monocyte/macrophage infiltration, nuclear factor-kappaB (NF-kappaB) and activator protein-1 (AP-1) activation, and c-fos expression in dTGR hearts. NF-kappaB subunit p65 and TF expression was increased in the endothelium and media of cardiac vessels and markedly reduced by valsartan treatment. To analyze the mechanism of TF transcription, we then transfected human coronary artery smooth muscle cells and Chinese hamster ovary cells overexpressing the AT(1) receptor with plasmids containing the human TF promoter and the luciferase reporter gene. ANG II induced the full-length TF promoter in both transfected cell lines. TF transcription was abolished by AT(1) receptor blockade. Deletion of both AP-1 and NF-kappaB sites reduced ANG II-induced TF gene transcription completely, whereas the deletion of AP-1 sites reduced transcription. Thus, the present study clearly shows an aberrant TF expression in the endothelium and media in rats with ANG II-induced vasculopathy. The beneficial effects of AT(1) receptor blockade in this model are mediated via the inhibition of NF-kappaB and AP-1 activation, thereby preventing TF expression, cardiac vasculopathy, and

  3. Angiotensin II (AT1) Receptor Blockade Reduces Vascular Tissue Factor in Angiotensin II-Induced Cardiac Vasculopathy

    PubMed Central

    Müller, Dominik N.; Mervaala, Eero M. A.; Dechend, Ralf; Fiebeler, Anette; Park, Joon-Keun; Schmidt, Folke; Theuer, Jürgen; Breu, Volker; Mackman, Nigel; Luther, Thomas; Schneider, Wolfgang; Gulba, Dietrich; Ganten, Detlev; Haller, Hermann; Luft, Friedrich C.

    2000-01-01

    Tissue factor (TF), a main initiator of clotting, is up-regulated in vasculopathy. We tested the hypothesis that chronic in vivo angiotensin (ANG) II receptor AT1 receptor blockade inhibits TF expression in a model of ANG II-induced cardiac vasculopathy. Furthermore, we explored the mechanisms by examining transcription factor activation and analyzing the TF promoter. Untreated transgenic rats overexpressing the human renin and angiotensinogen genes (dTGR) feature hypertension and severe left ventricular hypertrophy with focal areas of necrosis, and die at age 7 weeks. Plasma and cardiac ANG II was three- to fivefold increased compared to Sprague-Dawley rats. Chronic treatment with valsartan normalized blood pressure and coronary resistance completely, and ameliorated cardiac hypertrophy (P < 0.001). Valsartan prevented monocyte/macrophage infiltration, nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) activation, and c-fos expression in dTGR hearts. NF-κB subunit p65 and TF expression was increased in the endothelium and media of cardiac vessels and markedly reduced by valsartan treatment. To analyze the mechanism of TF transcription, we then transfected human coronary artery smooth muscle cells and Chinese hamster ovary cells overexpressing the AT1 receptor with plasmids containing the human TF promoter and the luciferase reporter gene. ANG II induced the full-length TF promoter in both transfected cell lines. TF transcription was abolished by AT1 receptor blockade. Deletion of both AP-1 and NF-κB sites reduced ANG II-induced TF gene transcription completely, whereas the deletion of AP-1 sites reduced transcription. Thus, the present study clearly shows an aberrant TF expression in the endothelium and media in rats with ANG II-induced vasculopathy. The beneficial effects of AT1 receptor blockade in this model are mediated via the inhibition of NF-κB and AP-1 activation, thereby preventing TF expression, cardiac vasculopathy, and microinfarctions. PMID

  4. Effect of chronic treatment with angiotensin type 1 receptor antagonists on striatal dopamine levels in normal rats and in a rat model of Parkinson's disease treated with L-DOPA.

    PubMed

    Dominguez-Meijide, Antonio; Villar-Cheda, Begoña; Garrido-Gil, Pablo; Sierrra-Paredes, German; Guerra, Maria J; Labandeira-Garcia, Jose L

    2014-01-01

    Beneficial effects of angiotensin type-1 receptor (AT1) inhibition have been observed in a number of brain processes mediated by oxidative stress and neuroinflammation, including Parkinson's disease. However, important counterregulatory interactions between dopamine and angiotensin systems have recently been demonstrated in several peripheral tissues, and it is possible that a decrease in dopamine levels due to AT1 inhibition may interfere with neuroprotective strategies. The present experiments involving rats with normal dopaminergic innervation indicate that chronic treatment with the AT1 antagonist candesartan does not significantly affect striatal levels of dopamine, serotonin or metabolites, as does not significantly affect motor behavior, as evaluated by the rotarod test. Interestingly, chronic administration of candesartan to normal rats induced a marked increase in dopamine D1 and a decrease in dopamine D2 receptor expression. In a rat model of Parkinson's disease treated with L-DOPA, no differences in striatal dopamine and serotonin levels were observed between candesartan-treated rats and untreated, which suggests that chronic treatment with candesartan does not significantly affect the process of L-DOPA decarboxylation and dopamine release in Parkinson's disease patients. Candesartan did not induce any differences in the striatal expression of dopamine D1 and D2 and serotonin 5-HT1B receptors in 6ydroxydopamine-lesioned rats treated with L-DOPA. The results suggest that chronic treatment with AT1 antagonists as a neuroprotective strategy does not significantly affect striatal dopamine release or motor behavior. This article is part of the Special Issue entitled 'The Synaptic Basis of Neurodegenerative Disorders'. PMID:23973568

  5. An Orphan G Protein-Coupled Receptor, GPR1, Acts as a Coreceptor To Allow Replication of Human Immunodeficiency Virus Types 1 and 2 in Brain-Derived Cells

    PubMed Central

    Shimizu, Nobuaki; Soda, Yasushi; Kanbe, Katsuaki; Liu, Hui-Yu; Jinno, Atsushi; Kitamura, Toshio; Hoshino, Hiroo

    1999-01-01

    Twelve G protein-coupled receptors, including chemokine receptors, act as coreceptors and determinants for the cell tropisms of human immunodeficiency virus type 1 (HIV-1), HIV-2, and simian immunodeficiency virus (SIV). We isolated HIV-1 variants from T-cell-line (T)- and macrophage (M)-tropic (i.e., dualtropic) (R5-R3-X4) HIV-1 strains and also produced six HIV-1 mutants carrying single-point amino acid substitutions at the tip of the V3 region of the Env protein of HIV-1. These variants and three mutants infected brain-derived CD4-positive cells that are resistant to M-, T-, or dualtropic (R5, X4, or R5-X4) HIV-1 strains. However, a factor that determines this cell tropism has not been identified. This study shows that primary brain-derived fibroblast-like cell strains, BT-3 and BT-20/N, as well as a CD4-transduced glioma cell line, U87/CD4, which were susceptible to these HIV-1 variants and mutants and the HIV-2ROD strain, expressed mRNA of an orphan G protein-coupled receptor (GPCR), GPR1. When a CD4-positive cell line which was strictly resistant to infection with diverse HIV-1 and HIV-2 strains was transduced with GPR1, the cell line became susceptible to these HIV-1 variants and mutants and to an HIV-2 strain but not to T- or dualtropic HIV-1 strains, and numerous syncytia formed after infection. These results indicate that GPR1 functions as a coreceptor for the HIV-1 variants and mutants and for the HIV-2ROD strain in vitro. PMID:10233994

  6. Identification of heparin-binding EGF-like growth factor (HB-EGF) as a biomarker for lysophosphatidic acid receptor type 1 (LPA1) activation in human breast and prostate cancers.

    PubMed

    David, Marion; Sahay, Debashish; Mege, Florence; Descotes, Françoise; Leblanc, Raphaël; Ribeiro, Johnny; Clézardin, Philippe; Peyruchaud, Olivier

    2014-01-01

    Lysophosphatidic acid (LPA) is a natural bioactive lipid with growth factor-like functions due to activation of a series of six G protein-coupled receptors (LPA₁₋₆). LPA receptor type 1 (LPA₁) signaling influences the pathophysiology of many diseases including cancer, obesity, rheumatoid arthritis, as well as lung, liver and kidney fibrosis. Therefore, LPA₁ is an attractive therapeutic target. However, most mammalian cells co-express multiple LPA receptors whose co-activation impairs the validation of target inhibition in patients because of missing LPA receptor-specific biomarkers. LPA₁ is known to induce IL-6 and IL-8 secretion, as also do LPA₂ and LPA₃. In this work, we first determined the LPA induced early-gene expression profile in three unrelated human cancer cell lines expressing different patterns of LPA receptors (PC3: LPA₁,₂,₆; MDA-MB-231: LPA1,2; MCF-7: LPA₂,₆). Among the set of genes upregulated by LPA only in LPA₁-expressing cells, we validated by QPCR and ELISA that upregulation of heparin-binding EGF-like growth factor (HB-EGF) was inhibited by LPA₁-₃ antagonists (Ki16425, Debio0719). Upregulation and downregulation of HB-EGF mRNA was confirmed in vitro in human MDA-B02 breast cancer cells stably overexpressing LPA₁ (MDA-B02/LPA₁) and downregulated for LPA₁ (MDA-B02/shLPA1), respectively. At a clinical level, we quantified the expression of LPA₁ and HB-EGF by QPCR in primary tumors of a cohort of 234 breast cancer patients and found a significantly higher expression of HB-EGF in breast tumors expressing high levels of LPA₁. We also generated human xenograph prostate tumors in mice injected with PC3 cells and found that a five-day treatment with Ki16425 significantly decreased both HB-EGF mRNA expression at the primary tumor site and circulating human HB-EGF concentrations in serum. All together our results demonstrate that HB-EGF is a new and relevant biomarker with potentially high value in quantifying LPA

  7. Ferristatin II Promotes Degradation of Transferrin Receptor-1 In Vitro and In Vivo

    PubMed Central

    Kim, Jonghan; Luo, Flora; Sanford, Jack; Chen, Juxing; Enns, Caroline; Wessling-Resnick, Marianne

    2013-01-01

    Previous studies have shown that the small molecule iron transport inhibitor ferristatin (NSC30611) acts by down-regulating transferrin receptor-1 (TfR1) via receptor degradation. In this investigation, we show that another small molecule, ferristatin II (NSC8679), acts in a similar manner to degrade the receptor through a nystatin-sensitive lipid raft pathway. Structural domains of the receptor necessary for interactions with the clathrin pathway do not appear to be necessary for ferristatin II induced degradation of TfR1. While TfR1 constitutively traffics through clathrin-mediated endocytosis, with or without ligand, the presence of Tf blocked ferristatin II induced degradation of TfR1. This effect of Tf was lost in a ligand binding receptor mutant G647A TfR1, suggesting that Tf binding to its receptor interferes with the drug’s activity. Rats treated with ferristatin II have lower TfR1 in liver. These effects are associated with reduced intestinal 59Fe uptake, lower serum iron and transferrin saturation, but no change in liver non-heme iron stores. The observed hypoferremia promoted by degradation of TfR1 by ferristatin II appears to be due to induced hepcidin gene expression. PMID:23894616

  8. Angiotensin II modulates mouse skeletal muscle resting conductance to chloride and potassium ions and calcium homeostasis via the AT1 receptor and NADPH oxidase

    PubMed Central

    Cozzoli, Anna; Liantonio, Antonella; Conte, Elena; Cannone, Maria; Massari, Ada Maria; Giustino, Arcangela; Scaramuzzi, Antonia; Pierno, Sabata; Mantuano, Paola; Capogrosso, Roberta Francesca; Camerino, Giulia Maria

    2014-01-01

    Angiotensin II (ANG II) plays a role in muscle wasting and remodeling; however, little evidence shows its direct effects on specific muscle functions. We presently investigated the acute in vitro effects of ANG II on resting ionic conductance and calcium homeostasis of mouse extensor digitorum longus (EDL) muscle fibers, based on previous findings that in vivo inhibition of ANG II counteracts the impairment of macroscopic ClC-1 chloride channel conductance (gCl) in the mdx mouse model of muscular dystrophy. By means of intracellular microelectrode recordings we found that ANG II reduced gCl in the nanomolar range and in a concentration-dependent manner (EC50 = 0.06 μM) meanwhile increasing potassium conductance (gK). Both effects were inhibited by the ANG II receptors type 1 (AT1)-receptor antagonist losartan and the protein kinase C inhibitor chelerythrine; no antagonism was observed with the AT2 antagonist PD123,319. The scavenger of reactive oxygen species (ROS) N-acetyl cysteine and the NADPH-oxidase (NOX) inhibitor apocynin also antagonized ANG II effects on resting ionic conductances; the ANG II-dependent gK increase was blocked by iberiotoxin, an inhibitor of calcium-activated potassium channels. ANG II also lowered the threshold for myofiber and muscle contraction. Both ANG II and the AT1 agonist L162,313 increased the intracellular calcium transients, measured by fura-2, with a two-step pattern. These latter effects were not observed in the presence of losartan and of the phospholipase C inhibitor U73122 and the in absence of extracellular calcium, disclosing a Gq-mediated calcium entry mechanism. The data show for the first time that the AT1-mediated ANG II pathway, also involving NOX and ROS, directly modulates ion channels and calcium homeostasis in adult myofibers. PMID:25080489

  9. [76Br]BMK-152, a non-peptide analogue, with high affinity and low non-specific binding for the Corticotropin-Releasing Factor Type 1 Receptor (CRF1 receptor)

    PubMed Central

    Jagoda, Elaine M.; Lang, Lixin; McCullough, Karen; Contoreggi, Carlo; Kim, B. Moon; Ma, Ying; Rice, Kenner C.; Szajek, Lawrence P; Eckelman, William C.; Kiesewetter, Dale O.

    2013-01-01

    Corticotropin-releasing factor (CRF), a neuropeptide, regulates endocrine and autonomic responses to stress through G-protein coupled receptors, CRF1 or CRF2. A PET ligand able to monitor changes in CRF1 receptor occupancy in vivo would aid in understanding the pathophysiology of stress related diseases as well as in the clinical development of non-peptide antagonists with therapeutic value. We have radiolabeled the CRF1 receptor ligand, BMK-152 ([8-(4-bromo-2,6-dimethoxyphenyl)-2,7-dimethylpyrazolo[1,5-α][1,3,5]triazin-4-yl]-N,N-bis-(2-methoxyethyl)amine; ClogP= 2.6), at both the 3 and 4 position with [76Br]. Using in vitro autoradiography saturation studies the 4-[76Br]BMK-152 exhibited high affinity binding to both rat (Kd = 0.23 ± 0.07 nM; n=3) and monkey frontal cortex (Kd = 0.31 ± 0.08 nM; n=3) consistent with CRF1 receptor regional distribution whereas with the 3-[76Br]BMK-152, the Kd's could not be determined due to high non-specific binding. In vitro autoradiography competition studies using [125I]Tyr0-o-CRF confirmed that 3-Br-BMK-152 (Ki = 24.4 ± 4.9 nM; n=3) had lower affinity (70 fold) than 4-Br-BMK-152 (Ki = 0.35 ± 0.07 nM; n=3) in monkey frontal cortex and similiar studies using [125I]Sauvagine confirmed CRF1 receptor selectivity. In vivo studies with P-glycoprotein (PGP) knockout mice (KO) and their wildtype littermates (WT) showed that the brain uptake of 3-[76Br]BMK/4-[76Br]BMK was increased < 2 fold in KO vs WT indicating that 3-[76Br]BMK-152/4-[76Br]BMK was not a Pgp substrate. Rat brain uptakes of 4-[76Br] BMK-152 from ex vivo autoradiography studies showed regional localization consistent with known published CRF1 receptor distribution and potential as a PET ligand for in vivo imaging of CRF1 receptors. PMID:21308801

  10. Identification of the angiotensin II receptor in rat mesenteric artery.

    PubMed Central

    McQueen, J; Murray, G D; Semple, P F

    1984-01-01

    Specific binding sites of high affinity and low capacity for 125I-angiotensin II have been identified in a membrane fraction derived from arterial arcades of the rat mesentery. Heterogeneity of binding sites and extensive tracer degradation necessitated the use of nonlinear regression methods for the analysis of radioligand binding data. Forward and reverse rate constants for the high affinity sites obtained by three experimental approaches were in good agreement and gave a dissociation equilibrium constant (Kd) of 19-74 pM (95% confidence interval). Affinities for a number of angiotensin-related peptides calculated from competitive binding curves were in the order 125I-angiotensin II = angiotensin II greater than angiotensin III greater than [Sar1,Ile8]angiotensin II greater than [Sar1,Gly8]angiotensin II. Angiotensin I and biochemically unrelated peptides had virtually no effect on binding of tracer angiotensin II. The divalent cations Mn2+, Mg2+ and Ca2+ stimulated 125I-angiotensin II binding at concentrations of 2-10 mM, as did Na+ at 50-100 mM. In the presence of Na+ or Li+, K+ had a biphasic effect. The chelating agents EDTA and EGTA were inhibitory, as were the thiol reagents dithiothreitol and cysteine. This study defined angiotensin II binding sites in a vascular target tissue of sufficiently high affinity to interact rapidly with plasma angiotensin II at physiological concentrations. PMID:6095806

  11. A peptide tetramer Tk-tPN induces tolerance of cardiac allografting by conversion of type 1 to type 2 immune responses via the Toll-like receptor 2 signal-promoted activation of the MCP1 gene.

    PubMed

    Li, Zuoqing; Yang, Neng; Zhou, Ling; Gu, Peng; Wang, Hui; Zhou, Yun; Zhou, Peijun; Lu, Liming; Chou, Kuang-Yen

    2016-03-01

    The plant protein trichosanthin (Tk) and its derived peptide tetramer Tk-tPN have been shown to stimulate the type 2 immune responses for treating autoimmune disease. This work explores the possibility of using Tk-tPN as a non-toxic immunosuppressant to induce transplantation tolerance using the mechanisms by which T-cell-mediated immune responses are transferred from type 1 to type 2 through innate immunity-related pathways. Immunocytes and cytokine secretions involved in the mouse cardiac allografting model with Tk-tPN treatment were characterized. Identification of critical genes and analysis of their functions through Toll-like receptor (TLR) -initiated signalling and the possible epigenetic changes were performed. Mean survival times of the cardiac allografts were delayed from 7.7 ± 0.3 days (control) to 22.7 ± 3.9 days (P < 0.01) or 79.1 ± 19.2 days (P < 0.0001) when Tk-tPN was introduced into the recipients alone or together with rapamycin, respectively. The grafting tolerance was donor-specific. The secretion pattern of the type 1 cytokine/transcription factor (IL-2(+) IFN-γ(+) T-bet(+)), which is responsible for the acute graft rejection, was shifted to the type 2 factor (IL-4(+) IL-10(+) Gata3+), together with a selective expansion of the IL-4/IL-10-producing CD8+ CD28- regulatory T-cell subset. A TLR2-initiated high expression of chemokine gene MCP1 was detectable simultaneously. Epigenetically Tk/Tk-tPN could also acetylate the histone H3K9 of MCP1 promoter to skew the immunity towards T helper type 2 responses. Tk/Tk-tPN is therefore capable of down-regulating the type 1 response-dominant rejection of cardiac allografts by evoking type 2 immunity through the activation of a TLR2-initiated signalling pathway and MCP1 gene to expand the IL-4/IL-10-secreting CD8+ CD28- regulatory T cells. Tk-tPN could be a promising novel immunosuppressant to induce tolerance in allotransplantation. PMID:26694804

  12. An elevation in physical coupling of type 1 inositol 1,4,5-trisphosphate (IP3) receptors to transient receptor potential 3 (TRPC3) channels constricts mesenteric arteries in genetic hypertension.

    PubMed

    Adebiyi, Adebowale; Thomas-Gatewood, Candice M; Leo, M Dennis; Kidd, Michael W; Neeb, Zachary P; Jaggar, Jonathan H

    2012-11-01

    Hypertension is associated with an elevation in agonist-induced vasoconstriction, but mechanisms involved require further investigation. Many vasoconstrictors bind to phospholipase C-coupled receptors, leading to an elevation in inositol 1,4,5-trisphosphate (IP(3)) that activates sarcoplasmic reticulum IP(3) receptors. In cerebral artery myocytes, IP(3) receptors release sarcoplasmic reticulum Ca(2+) and can physically couple to canonical transient receptor potential 3 (TRPC3) channels in a caveolin-1-containing macromolecular complex, leading to cation current activation that stimulates vasoconstriction. Here, we investigated mechanisms by which IP(3) receptors control vascular contractility in systemic arteries and IP(3)R involvement in elevated agonist-induced vasoconstriction during hypertension. Total and plasma membrane-localized TRPC3 protein was ≈2.7- and 2-fold higher in mesenteric arteries of spontaneously hypertensive rats (SHRs) than in Wistar-Kyoto (WKY) rat controls, respectively. In contrast, IP(3)R1, TRPC1, TRPC6, and caveolin-1 expression was similar. TRPC3 expression was also similar in arteries of pre-SHRs and WKY rats. Control, IP(3)-induced and endothelin-1 (ET-1)-induced fluorescence resonance energy transfer between IP3R1 and TRPC3 was higher in SHR than WKY myocytes. IP3-induced cation current was ≈3-fold larger in SHR myocytes. Pyr3, a selective TRPC3 channel blocker, and calmodulin and IP(3) receptor binding domain peptide, an IP(3)R-TRP physical coupling inhibitor, reduced IP(3)-induced cation current and ET-1-induced vasoconstriction more in SHR than WKY myocytes and arteries. Thapsigargin, a sarcoplasmic reticulum Ca(2+)-ATPase blocker, did not alter ET-1-stimulated vasoconstriction in SHR or WKY arteries. These data indicate that ET-1 stimulates physical coupling of IP(3)R1 to TRPC3 channels in mesenteric artery myocytes, leading to vasoconstriction. Furthermore, an elevation in IP(3)R1 to TRPC3 channel molecular coupling augments

  13. Identification and characterization of an angiotensin II receptor on cultured bovine adrenal chromaffin cells

    SciTech Connect

    Boyd, V.L.

    1987-01-01

    The presence of an angiotensin II receptor on cultured bovine adrenal chromaffin cells was demonstrated by radioligand binding. A single class of finding sites with a K/sub D/ of 0.7 nM was characterized. The use of radioligands also allows the localization of receptors by autoradiography. Autoradiography demonstrated that approximately 50% of the isolated cells bound angiotensin II. It was of interest to see if angiotensin II bound to a cell that possessed a certain phenotype. In order to evaluate this possibility a technique was developed that combined autoradiography and immunocytochemistry. Results indicated that angiotensin II binding sites were not localized preferentially to either norepinephrine or epinephrine cells. Binding of angiotensin II was associated with the release of intracellular catecholamine stores. Cells were pre-loaded with /sup 3/H-norepinephrine and secretion was monitored by following radioactivity released into the supernatant. Alternatively, release of endogenous catecholamines was determined by fluorometric assay.

  14. Excitation of type II anterior caudate neurons by stimulation of dopamine D3 receptors.

    PubMed

    Piercey, M F; Hyslop, D K; Hoffmann, W E

    1997-07-11

    Previous studies have demonstrated that both direct- and indirect-acting dopamine (DA) receptor agonists excite type II neurons in the anterior caudate (CN) by stimulation of DA receptors belonging to the D2 receptor subfamily (D2, D3, D4 receptor subtypes). In the present study, pramipexole, a D3-preferring DA agonist effective in treating Parkinson's disease, excited type II anterior CN neurons. As with other direct-acting agonists, excitation of the CN neurons occurred only at doses above those that silenced DA neurons in the substantia nigra pars compacta (SNPC). Although more potent than pramipexole in inhibiting SNPC cells, PNU-91356A, a D2-preferring agonist, did not excite type II CN cells. The D3-preferring antagonist (+)-AJ76 was weaker than haloperidol, a D2-preferring antagonist, in reversing the effects of amphetamine on firing rates in dopaminergic neurons in both the SNPC and the CN. However, in relationship to its potency in the SNPC, (+)-AJ76 was more potent than haloperidol in the CN. PNU-101387, a selective D4 antagonist, did not alter amphetamine-induced stimulation of type II CN neurons. We conclude that DA agonists may excite type II anterior CN neurons via D3 receptor activation. The stimulation of these neurons may contribute to the anti-parkinsonian effects of pramipexole. PMID:9262154

  15. Angiotensin II AT1 receptor constitutive activation: from molecular mechanisms to pathophysiology.

    PubMed

    Petrel, Christophe; Clauser, Eric

    2009-04-29

    Mutations activating the angiotensin II AT(1) receptor are important to identify and characterize because they give access to the activation mechanisms of this G protein coupled receptor and help to characterize the signaling pathways and the potential pathophysiology of this receptor. The different constitutively activated mutations of the AT(1) receptor are mostly localized in transmembrane domains (TM) and their characterization demonstrated that release of intramolecular constraints and movements among these TM are a necessary step for receptor activation. These mutations constitutively activate Gq linked signaling pathways, receptor internalization and maybe the G protein-independent signaling pathways. Expression of such mutations in mice is linked to hypertension and cardiovascular diseases, but such natural mutations have not been identified in human pathology. PMID:19061936

  16. Solution structure of urotensin-II receptor extracellular loop III and characterization of its interaction with urotensin-II.

    PubMed

    Boivin, Stéphane; Ségalas-Milazzo, Isabelle; Guilhaudis, Laure; Oulyadi, Hassan; Fournier, Alain; Davoust, Daniel

    2008-05-01

    Urotensin-II (U-II) is a vasoactive hormone that acts through a G-protein-coupled receptor named UT. Recently, we have shown, using the surface plasmon resonance technology that human U-II (hU-II) interacts with the hUT(281-300) fragment, a segment containing the extracellular loop III (EC-III) and short extensions of the transmembrane domains VI and VII (TM-VI and TM-VII). To further investigate the interaction of UT receptor with U-II, we have determined the solution structure of hUT(281-300) by high-resolution NMR and molecular modeling and we have examined, also using NMR, the binding with hU-II at residue level. In the presence of dodecylphosphocholine micelles, hUT(281-300) exhibited a type III beta-turn (Q285-L288), followed by an -helical structure (A289-L299), the latter including a stretch of transmembrane helix VII. Upon addition of hU-II, significant chemical shift perturbations were observed for residues located just on the N-terminal side of the beta-turn (end of TM-VI/beginning of EC-III) and on one face of the -helix (end of EC-III/beginning of TM-VII). These data, in conjunction with intermolecular NOEs, suggest that the initiation site of EC-III, as well as the upstream portion of helix VII, would be involved in agonist binding and allow to propose points of interaction in the ligand-receptor complex. PMID:18423797

  17. 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.

  18. Quantitative autoradiography of angiotensin II receptors in the brain and kidney

    SciTech Connect

    Gehlert, D.R.

    1985-01-01

    The renin-angiotensin system is an important component in the regulation of systemic blood pressure. Angiotensin II is the principal effector peptide of this system. Interaction of angiotensin II with specific receptors can produce in several organic systems. When administered into the brain this octa-peptide produces a variety of responses including a stimulation of drinking, increased systemic blood pressure and several neuroendocrine responses. Its effects on the kidney include alterations in arteriolar resistance, mesangial cell contraction and a feedback inhibition of the release of renin. Since this peptide produces profound effects on homeostatis by an interaction with specific receptors, the quantitative technique of in vitro autoradiography was applied to localize receptor populations for angiotensin II. Specific binding sites for a radiolabeled form of angiotensin II were localized in various brain and kidney regions. In the rat brain high densities of angiotensin II receptors were observed in the paraventricular and suprachiasmatic nuclei of the hypothalamus, supraoptic nucleus and the posterior lobe of the pituitary, brain areas in which angiotensin II modified neuroendocrine functions.

  19. Insulin-like Growth Factor-II (IGF-II) and IGF-II Analogs with Enhanced Insulin Receptor-a Binding Affinity Promote Neural Stem Cell Expansion*

    PubMed Central

    Ziegler, Amber N.; Chidambaram, Shravanthi; Forbes, Briony E.; Wood, Teresa L.; Levison, Steven W.

    2014-01-01

    The objective of this study was to employ genetically engineered IGF-II analogs to establish which receptor(s) mediate the stemness promoting actions of IGF-II on mouse subventricular zone neural precursors. Neural precursors from the subventricular zone were propagated in vitro in culture medium supplemented with IGF-II analogs. Cell growth and identity were analyzed using sphere generation and further analyzed by flow cytometry. F19A, an analog of IGF-II that does not bind the IGF-2R, stimulated an increase in the proportion of neural stem cells (NSCs) while decreasing the proportion of the later stage progenitors at a lower concentration than IGF-II. V43M, which binds to the IGF-2R with high affinity but which has low binding affinity to the IGF-1R and to the A isoform of the insulin receptor (IR-A) failed to promote NSC growth. The positive effects of F19A on NSC growth were unaltered by the addition of a functional blocking antibody to the IGF-1R. Altogether, these data lead to the conclusion that IGF-II promotes stemness of NSCs via the IR-A and not through activation of either the IGF-1R or the IGF-2R. PMID:24398690

  20. Binding of type II nuclear receptors and estrogen receptor to full and half-site estrogen response elements in vitro.

    PubMed Central

    Klinge, C M; Bodenner, D L; Desai, D; Niles, R M; Traish, A M

    1997-01-01

    The mechanism by which retinoids, thyroid hormone (T3) and estrogens modulate the growth of breast cancer cells is unclear. Since nuclear type II nuclear receptors, including retinoic acid receptor (RAR), retinoid X receptor (RXR) and thyroid hormone receptor (TR), bind direct repeats (DR) of the estrogen response elements (ERE) half-site (5'-AGGTCA-3'), we examined the ability of estrogen receptor (ER) versus type II nuclear receptors, i.e. RARalpha, beta and gamma, RXRbeta, TRalpha and TRbeta, to bind various EREs in vitro . ER bound a consensus ERE, containing a perfectly palindromic 17 bp inverted repeat (IR), as a homodimer. In contrast, ER did not bind to a single ERE half-site. Likewise, ER did not bind two tandem (38 bp apart) half-sites, but low ER binding was detected to three tandem copies of the same half-site. RARalpha,beta or gamma bound both ERE and half-site constructs as a homodimer. RXRbeta did not bind full or half-site EREs, nor did RXRbeta enhance RARalpha binding to a full ERE. However, RARalpha and RXRbeta bound a half-site ERE cooperatively forming a dimeric complex. The RARalpha-RXRbeta heterodimer bound the Xenopus vitellogenin B1 estrogen responsive unit, with two non-consensus EREs, with higher affinity than one or two copies of the full or half-site ERE. Both TRalpha and TRbeta bound the full and the half-site ERE as monomers and homodimers and cooperatively as heterodimers with RXRbeta. We suggest that the cellular concentrations of nuclear receptors and their ligands, and the nature of the ERE or half-site sequence and those of its flanking sequences determine the occupation of EREs in estrogen-regulated genes in vivo . PMID: