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Sample records for growth hormone-releasing peptides

  1. Metabolism of growth hormone releasing peptides.

    PubMed

    Thomas, Andreas; Delahaut, Philippe; Krug, Oliver; Schänzer, Wilhelm; Thevis, Mario

    2012-12-01

    New, potentially performance enhancing compounds have frequently been introduced to licit and illicit markets and rapidly distributed via worldwide operating Internet platforms. Developing fast analytical strategies to follow these new trends is one the most challenging issues for modern doping control analysis. Even if reference compounds for the active drugs are readily obtained, their unknown metabolism complicates effective testing strategies. Recently, a new class of small C-terminally amidated peptides comprising four to seven amino acid residues received considerable attention of sports drug testing authorities due to their ability to stimulate growth hormone release from the pituitary. The most promising candidates are the growth hormone releasing peptide (GHRP)-1, -2, -4, -5, -6, hexarelin, alexamorelin, and ipamorelin. With the exemption of GHRP-2, the entity of these peptides represents nonapproved pharmaceuticals; however, via Internet providers, all compounds are readily available. To date, only limited information on the metabolism of these substances is available and merely one metabolite for GHRP-2 is established. Therefore, a comprehensive in vivo (po and iv administration in rats) and in vitro (with human serum and recombinant amidase) study was performed in order to generate information on urinary metabolites potentially useful for routine doping controls. The urine samples from the in vivo experiments were purified by mixed-mode cation-exchange solid-phase extraction and analyzed by ultrahigh-performance liquid chromatography (UHPLC) separation followed by high-resolution/high-accuracy mass spectrometry. Combining the high resolution power of a benchtop Orbitrap mass analyzer for the first metabolite screening and the speed of a quadrupole/time-of-flight (Q-TOF) instrument for identification, urinary metabolites were screened by means of a sensitive full scan analysis and subsequently confirmed by high-accuracy product ion scan experiments. Two

  2. Gastric motor effects of ghrelin and growth hormone releasing peptide 6 in diabetic mice with gastroparesis

    PubMed Central

    Qiu, Wen-Cai; Wang, Zhi-Gang; Wang, Wei-Gang; Yan, Jun; Zheng, Qi

    2008-01-01

    AIM: To investigate the potential therapeutic significance of ghrelin and growth hormone releasing peptide 6 (GHRP-6) in diabetic mice with gastric motility disorders. METHODS: A diabetic mouse model was established by intraperitoneal (ip) injection of alloxan. Diabetic mice were injected ip with ghrelin or GHRP-6 (20-200 μg/kg), and the effects on gastric emptying were measured after intragastric application of phenol red. The effect of atropine, NG-nitro-L-arginine methyl ester hydrochloride (L-NAME) or D-Lys3-GHRP-6 (a growth hormone secretagogue receptor (GHS-R) antagonist) on the gastroprokinetic effect of ghrelin or GHRP-6 (100 μg/kg) was also investigated. The effects of ghrelin or GHRP-6 (0.01-10 μmol/L) on spontaneous or carbachol-induced contractile amplitude were also investigated in vitro, in gastric fundic circular strips taken from diabetic mice. The presence of growth hormone secretagogue receptor 1a transcripts in the fundic strips of diabetic mice was detected by reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: We established a diabetic mouse model with delayed gastric emptying. Ghrelin and GHRP-6 accelerated gastric emptying in diabetic mice with gastroparesis. In the presence of atropine or L-NAME, which delayed gastric emptying, ghrelin and GHRP-6 (100 μg/kg) failed to accelerate gastric emptying. D-Lys3-GHRP-6 also delayed gastric emptying induced by the GHS-R agonist. Ghrelin and GHRP-6 increased the carbachol-induced contractile amplitude in gastric fundic strips taken from diabetic mice. RT-PCR confirmed the presence of GHS-R mRNA in the strip preparations. CONCLUSION: Ghrelin and GHRP-6 increase gastric emptying in diabetic mice with gastroparesis, perhaps by activating peripheral cholinergic pathways in the enteric nervous system. PMID:18322959

  3. Transplacental transfer of a growth hormone-releasing hormone peptide from mother to fetus in the rat.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous studies showed that when growth hormone-releasing hormone (GHRH) was administered to either pregnant rats or pigs as a plasmid-mediated therapy, pituitary weight, somatotroph and lactotroph numbers, and postnatal growth rate of the offspring increased. To determine if these responses result...

  4. Growth Hormone-Releasing Peptide 6 Enhances the Healing Process and Improves the Esthetic Outcome of the Wounds

    PubMed Central

    Mendoza Marí, Yssel; Fernández Mayola, Maday; Aguilera Barreto, Ana; García Ojalvo, Ariana; Bermúdez Alvarez, Yilian; Mir Benítez, Ana Janet; Berlanga Acosta, Jorge

    2016-01-01

    In addition to its cytoprotective effects, growth hormone-releasing peptide 6 (GHRP-6) proved to reduce liver fibrotic induration. CD36 as one of the GHRP-6 receptors appears abundantly represented in cutaneous wounds granulation tissue. The healing response in a scenario of CD36 agonistic stimulation had not been previously investigated. Excisional full-thickness wounds (6 mmØ) were created in the dorsum of Wistar rats and topically treated twice a day for 5 days. The universal model of rabbit's ears hypertrophic scars was implemented and the animals were treated daily for 30 days. Treatments for both species were based on a CMC jelly composition containing GHRP-6 400 μg/mL. Wounds response characterization included closure dynamic, RT-PCR transcriptional profile, histology, and histomorphometric procedures. The rats experiment indicated that GHRP-6 pharmacodynamics involves attenuation of immunoinflammatory mediators, their effector cells, and the reduction of the expression of fibrotic cytokines. Importantly, in the hypertrophic scars rabbit's model, GHRP-6 intervention dramatically reduced the onset of exuberant scars by activating PPARγ and reducing the expression of fibrogenic cytokines. GHRP-6 showed no effect on the reversion of consolidated lesions. This evidence supports the notion that CD36 is an active and pharmacologically approachable receptor to attenuate wound inflammation and accelerate its closure so as to improve wound esthetic. PMID:27200188

  5. Growth Hormone Releasing Peptide-2 Attenuation of Protein Kinase C-Induced Inflammation in Human Ovarian Granulosa Cells

    PubMed Central

    Chao, Yi-Ning; Sun, David; Peng, Yen-Chun; Wu, Yuh-Lin

    2016-01-01

    Cyclooxygenase-2 (COX-2) and interleukin-8 (IL-8) are two important inflammatory mediators in ovulation. Ghrelin may modulate inflammatory signaling via growth hormone secretagogue receptors. We investigated the role of ghrelin in KGN human ovarian granulosa cells using protein kinase C (PKC) activator phorbol 12, 13-didecanoate (PDD) and synthetic ghrelin analog growth hormone releasing peptide-2 (GHRP-2). GHRP-2 attenuated PDD-induced expression of protein and mRNA, the promoter activity of COX-2 and IL-8 genes, and the secretion of prostaglandin E2 (PGE2) and IL-8. GHRP-2 promoted the degradation of PDD-induced COX-2 and IL-8 proteins with the involvement of proteasomal and lysosomal pathways. PDD-mediated COX-2 production acts via the p38, c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathways; PDD-mediated IL-8 production acts via the p38, JNK and ERK pathways. GHRP-2 reduced the PDD-induced phosphorylation of p38 and JNK and activator protein 1 (AP-1) reporter activation and PDD-induced NF-κB nuclear translocation and reporter activation. The inhibitors of mitogen-activated protein kinase phosphatase-1 (MKP-1) and protein phosphatase 2 (PP2A) reduced the inhibitory effect of GHRP-2 on PDD-induced COX-2 and IL-8 expression. Our findings demonstrate an anti-inflammatory role for ghrelin (GHRP-2) in PKC-mediated inflammation of granulosa cells, at least in part, due to its inhibitory effect on PKC-induced activation of p38, JNK and NF-κB, possibly by targeting to MKP-1 and PP2A. PMID:27548147

  6. Pralmorelin: GHRP 2, GPA 748, growth hormone-releasing peptide 2, KP-102 D, KP-102 LN, KP-102D, KP-102LN.

    PubMed

    2004-01-01

    Pralmorelin [GPA 748, GHRP 2, growth hormone-releasing peptide 2, KP-102 D, KP 102 LN] is an orally active, synthetic growth hormone-releasing peptide from a series of compounds that were developed by Polygen in Germany and Tulane University in the US. Researchers at Tulane University led by Dr Cyril Bowers synthesised a series of small highly active peptides ranging in size from 3-5 amino acids or partial peptides that were suitable for a variety of administration formats (subcutaneous, buccal, oral, depot). These peptides mimic the actions of ghrelin, a 28 amino acid octanoyl peptide that regulates the release of growth hormone (GH), and may play an important role in bone and muscle growth, food intake and possibly improve recovery from injury. The use of pralmorelin as a diagnostic agent for GH deficiency is based on its ability to markedly increase plasma levels of GH in healthy subjects irrespectively of gender, obesity or age. However, in patients with GH deficiency, the effect of pralmorelin on GH levels is significantly lower compared with healthy controls. Analysis of the receiver-operating characteristics curve provided the cut-off threshold value for the GH peak of 15.0 micro g/L for the identification of patients with GH deficiency from those of healthy controls. Kaken acquired worldwide manufacturing and marketing rights to pralmorelin, and then sublicensed it to Wyeth (formerly American Home Products) for the US and Canada. Kaken retains rights to pralmorelin in Japan. On 11 March 2002 American Home Products changed its name and the names of its subsidiaries Wyeth-Ayerst and Wyeth Lederle to Wyeth. Kaken also granted exclusive sublicense options in Africa, Australia, Europe, Latin America and New Zealand to unspecified partners. Pralmorelin as KP-102 D [KP-102D] is currently awaiting approval in Japan as a diagnostic agent for hypothalamo-pituitary function. It is planned to be launched in Japan for this indication in 2004. Pralmorelin is also

  7. Growth hormone-releasing peptide-biotin conjugate stimulates myocytes differentiation through insulin-like growth factor-1 and collagen type I

    PubMed Central

    Lim, Chae Jin; Jeon, Jung Eun; Jeong, Se Kyoo; Yoon, Seok Jeong; Kwon, Seon Deok; Lim, Jina; Park, Keedon; Kim, Dae Yong; Ahn, Jeong Keun; Kim, Bong-Woo

    2015-01-01

    Based on the potential beneficial effects of growth hormone releasing peptide (GHRP)-6 on muscle functions, a newly synthesized GHRP-6-biotin conjugate was tested on cultured myoblast cells. Increased expression of myogenic marker proteins was observed in GHRP-6-biotin conjugate-treated cells. Additionally, increased expression levels of insulin-like growth factor-1 and collagen type I were observed. Furthermore, GHRP-6-biotin conjugate-treated cells showed increased metabolic activity, as indicated by increased concentrations of energy metabolites, such as ATP and lactate, and increased enzymatic activity of lactate dehydrogenase and creatine kinase. Finally, binding protein analysis suggested few candidate proteins, including desmin, actin, and zinc finger protein 691 as potential targets for GHRP6-biotin conjugate action. These results suggest that the newly synthesized GHRP-6-biotin conjugate has myogenic stimulating activity through, at least in part, by stimulating collagen type I synthesis and several key proteins. Practical applications of the GHRP-6-biotin conjugate could include improving muscle condition. [BMB Reports 2015; 48(9): 501-506] PMID:25644636

  8. Growth hormone-releasing peptide-biotin conjugate stimulates myocytes differentiation through insulin-like growth factor-1 and collagen type I.

    PubMed

    Lim, Chae Jin; Jeon, Jung Eun; Jeong, Se Kyoo; Yoon, Seok Jeong; Kwon, Seon Deok; Lim, Jina; Park, Keedon; Kim, Dae Yong; Ahn, Jeong Keun; Kim, Bong-Woo

    2015-09-01

    Based on the potential beneficial effects of growth hormone releasing peptide (GHRP)-6 on muscle functions, a newly synthesized GHRP-6-biotin conjugate was tested on cultured myoblast cells. Increased expression of myogenic marker proteins was observed in GHRP-6-biotin conjugate-treated cells. Additionally, increased expression levels of insulin-like growth factor-1 and collagen type I were observed. Furthermore, GHRP-6-biotin conjugate-treated cells showed increased metabolic activity, as indicated by increased concentrations of energy metabolites, such as ATP and lactate, and increased enzymatic activity of lactate dehydrogenase and creatine kinase. Finally, binding protein analysis suggested few candidate proteins, including desmin, actin, and zinc finger protein 691 as potential targets for GHRP6-biotin conjugate action. These results suggest that the newly synthesized GHRP-6-biotin conjugate has myogenic stimulating activity through, at least in part, by stimulating collagen type I synthesis and several key proteins. Practical applications of the GHRP-6-biotin conjugate could include improving muscle condition. PMID:25644636

  9. Antagonistic actions of analogs related to growth hormone-releasing hormone (GHRH) on receptors for GHRH and vasoactive intestinal peptide on rat pituitary and pineal cells in vitro

    PubMed Central

    Rekasi, Zoltan; Varga, Jozsef L.; Schally, Andrew V.; Halmos, Gabor; Groot, Kate; Czompoly, Tamas

    2000-01-01

    Peptide analogs of growth hormone-releasing hormone (GHRH) can potentially interact with vasoactive intestinal peptide (VIP) receptors (VPAC1-R and VPAC2-R) because of the structural similarities of these two hormones and their receptors. We synthesized four new analogs related to GHRH (JV-1–50, JV-1–51, JV-1–52, and JV-1–53) with decreased GHRH antagonistic activity and increased VIP antagonistic potency. To characterize various peptide analogs for their antagonistic activity on receptors for GHRH and VIP, we developed assay systems based on superfusion of rat pituitary and pineal cells. Receptor-binding affinities of peptides to the membranes of these cells were also evaluated by radioligand competition assays. Previously reported GHRH antagonists JV-1–36, JV-1–38, and JV-1–42 proved to be selective for GHRH receptors, because they did not influence VIP-stimulated VPAC2 receptor-dependent prolactin release from pituitary cells or VPAC1 receptor-dependent cAMP efflux from pinealocytes but strongly inhibited GHRH-stimulated growth hormone (GH) release. Analogs JV-1–50, JV-1–51, and JV-1–52 showed various degrees of VPAC1-R and VPAC2-R antagonistic potency, although also preserving a substantial GHRH antagonistic effect. Analog JV-1–53 proved to be a highly potent VPAC1 and VPAC2 receptor antagonist, devoid of inhibitory effects on GHRH-evoked GH release. The antagonistic activity of these peptide analogs on processes mediated by receptors for GHRH and VIP was consistent with the binding affinity. The analogs with antagonistic effects on different types of receptors expressed on tumor cells could be utilized for the development of new approaches to treatment of various human cancers. PMID:10655511

  10. One-year intranasal application of growth hormone releasing peptide-2 improves body weight and hypoglycemia in a severely emaciated anorexia nervosa patient

    PubMed Central

    Haruta, Izumi; Fuku, Yuki; Kinoshita, Kazuhisa; Yoneda, Koichi; Morinaga, Akinori; Amitani, Marie; Amitani, Haruka; Asakawa, Akihiro; Sugawara, Hideki; Takeda, Yasuo; Bowers, Cyril Y; Inui, Akio

    2015-01-01

    Background In Japan, growth hormone releasing peptide-2 (GHRP-2) is clinically used as a diagnostic agent for growth hormone secretion deficiency, but the therapeutic application of GHRP-2 has not been studied in anorexia nervosa. GHRP-2 reportedly exhibits agonistic action for ghrelin receptor and increases food intake. Methods We administered GHRP-2 to a patient with a 20-year history of anorexia nervosa to determine whether GHRP-2 treatment increases food intake and body weight. GHRP-2 was administered before every meal by an intranasal approach for 1 year. Results Although the patient reported a decreased fear of eating and decreased desire to be thin by our previous treatment, she was unable to increase food intake or body weight because of digestive tract dysfunction. Vomiting after meals caused by delayed gastric emptying and incurable constipation were prolonged, and sub-ileus and hypoglycemia were observed. GHRP-2 increased the feeling of hunger and food intake, decreased early satiety and improved hypoglycemia. The patient's body weight gradually increased by 6.7 kg (from 21.1 kg to 27.8 kg) in 14 months after starting GHRP-2 administration. The fatigability and muscle strength improved, and the physical and mental activities were also increased. No obvious side effects were observed after long-term intranasal administration of GHRP-2. Conclusions Patients with a long-term history of eating disorder occasionally recover from the psychological problems such as fear for obesity but remain emaciated. We believe that ghrelin agonists such as GHRP-2 may be promising agents for the effective treatments of severe anorexia nervosa in a chronic condition. PMID:26401470

  11. Determination of growth hormone releasing peptides metabolites in human urine after nasal administration of GHRP-1, GHRP-2, GHRP-6, Hexarelin, and Ipamorelin.

    PubMed

    Semenistaya, Ekaterina; Zvereva, Irina; Thomas, Andreas; Thevis, Mario; Krotov, Grigory; Rodchenkov, Grigory

    2015-10-01

    Growth hormone releasing peptides (GHRPs) stimulate secretion of endogenous growth hormone and are listed on the World Anti-Doping Agency (WADA) Prohibited List. To develop an effective method for GHRPs anti-doping control we have investigated metabolites of GHRP-1, GHRP-2, GHRP-6, Hexarelin, and Ipamorelin in urine after nasal administration. Each compound was administrated to one volunteer. Samples were collected for 2 days after administration, processed by solid-phase extraction on weak cation exchange cartridges and analyzed by means of nano-liquid chromatography - high resolution mass spectrometry. Six metabolites of GHRP-1 were identified. GHRP-1 in the parent form was not detected. GHRP-1 (2-4) free acid was detected in urine up to 27 h. GHRP-2, GHRP-2 free acid and GHRP-2 (1-3) free acid were detected in urine up to 47 h after administration. GHRP-6 was mostly excreted unchanged and detected in urine 23 h after administration, its metabolites were detectable for 12 h only. Hexarelin and Ipamorelin metabolized intensively and were excreted as a set of parent compounds with metabolites. Hexarelin (1-3) free acid and Ipamorelin (1-4) free acid were detected in urine samples after complete withdrawal of parent substances. GHRPs and their most prominent metabolites were included into routine ultra-pressure liquid chromatography-tandem mass spectrometry procedure. The method was fully validated, calibration curves of targeted analytes were obtained and excretion curves of GHRPs and their metabolites were plotted. Our results confirm that the detection window after GHRPs administration depends on individual metabolism, drug preparation form and the way of administration. PMID:25869809

  12. Pegylated peptides. V. Carboxy-terminal PEGylated analogs of growth hormone-releasing factor (GRF) display enhanced duration of biological activity in vivo.

    PubMed

    Campbell, R M; Heimer, E P; Ahmad, M; Eisenbeis, H G; Lambros, T J; Lee, Y; Miller, R W; Stricker, P R; Felix, A M

    1997-06-01

    In the present study, human growth hormone-releasing factor (hGRF) and analogs were successfully pegylated at the carboxy-terminus using a novel solid- and solution-phase strategy. Following synthesis, these pegylated hGRF analogs were evaluated for in vitro and in vivo biological activity. Specifically, hGRF (1-29)-NH2, [Ala15]-hGRF (1-29)-NH2, [desNH2Tyr1, D-Ala2, Ala15]-hGRF(1-29)-NH2 and [His1, Val2, Gln8, Ala15, Leu27]-hGRF(1-32)-OH were each C-terminally extended using a Gly-Gly-Cys-NH2 spacer (previously demonstrated not to alter intrinsic biological activity), and then monopegylated via coupling to an activated dithiopyridyl-PEG reagent. PEG moieties of 750, 2000, 5000 or 10,000 molecular weight (MW) were examined to determine the effect of polymer weight on activity. Initial biological evaluations in vitro revealed that all C-terminally pegylated hGRF analogs retained high growth hormone (GH)-releasing potencies, regardless of the MW of PEG polymer employed. Two of these pegylated hGRF analogs, [desNH2Tyr1, D-Ala2, Ala15]-hGRF (1-29)-Gly-Gly-Cys(NH2)-S-Nle-PEG5000 and [His1, Val2, Gln8, Ala15, Leu27]-hGRF(1-32)-Gly-Cys(NH2)-S-Nle-PEG5000, were subsequently evaluated in both pig and mouse models and found to be highly potent (in vivo potency range = 12-55-fold that of native hGRF). Relative to their non-pegylated counterparts, these two pegylated hGRF analogs exhibited enhanced duration of activity. PMID:9266480

  13. Growth hormone releasing factor-like immunoreactivity in human milk.

    PubMed

    Werner, H; Amarant, T; Fridkin, M; Koch, Y

    1986-03-28

    The presence of immunoreactive growth hormone-releasing factor (GRF) in human milk has been demonstrated. By using sequential high performance liquid chromatography, it has been shown that most of the immunoreactivity co-elutes with the synthetic, hypothalamic-like, GRF (1-40). The concentrations of GRF detected (between 152 and 432 pg GRF/ml milk) exceed several fold its values in plasma. PMID:3083812

  14. Tissue deiodinase activity during prolonged critical illness: effects of exogenous thyrotropin-releasing hormone and its combination with growth hormone-releasing peptide-2.

    PubMed

    Debaveye, Yves; Ellger, Björn; Mebis, Liese; Van Herck, Erik; Coopmans, Willy; Darras, Veerle; Van den Berghe, Greet

    2005-12-01

    Prolonged critical illness is characterized by reduced pulsatile TSH secretion, causing reduced thyroid hormone release and profound changes in thyroid hormone metabolism, resulting in low circulating T(3) and elevated rT(3) levels. To further unravel the underlying mechanisms, we investigated the effects of exogenous TRH and GH-releasing peptide-2 (GHRP-2) in an in vivo model of prolonged critical illness. Burn-injured, parenterally fed rabbits were randomized to receive 4-d treatment with saline, 60 microg/kg.h GHRP-2, 60 microg/kg.h TRH, or 60 microg/kg.h TRH plus 60 microg/kg.h GHRP-2 started on d 4 of the illness (n = 8/group). The activities of the deiodinase 1 (D1), D2, and D3 in snap-frozen liver, kidney, and muscle as well as their impact on circulating thyroid hormone levels were studied. Compared with healthy controls, hepatic D1 activity in the saline-treated, ill animals was significantly down-regulated (P = 0.02), and D3 activity tended to be up-regulated (P = 0.06). Infusion of TRH and TRH plus GHRP-2 restored the catalytic activity of D1 (P = 0.02) and increased T(3) levels back within physiological range (P = 0.008). D3 activity was normalized by all three interventions, but only addition of GHRP-2 to TRH prevented the rise in rT(3) seen with TRH alone (P = 0.02). Liver D1 and D3 activity were correlated (respectively, positively and negatively) with the changes in circulating T(3) (r = 0.84 and r = -0.65) and the T(3)/rT(3) ratio (r = 0.71 and r = -0.60). We conclude that D1 activity during critical illness is suppressed and related to the alterations within the thyrotropic axis, whereas D3 activity tends to be increased and under the joint control of the somatotropic and thyrotropic axes. PMID:16150898

  15. Rat growth-hormone release stimulators from fenugreek seeds.

    PubMed

    Shim, Sang Hee; Lee, Eun Ju; Kim, Ju Sun; Kang, Sam Sik; Ha, Hyekyung; Lee, Ho Young; Kim, Chungsook; Lee, Je-Hyun; Son, Kun Ho

    2008-09-01

    Bioassay-guided fractionation of MeOH extract from fenugreek (Trigonella foenum-graecum L.) seeds resulted in the isolation of two rat growth-hormone release stimulators in vitro, fenugreek saponin I (1) and dioscin (9), along with two new, i.e., 2 and 3, and five known analogues, i.e., 4-8. The structures of the new steroidal saponins, fenugreek saponins I, II, and III (1-3, resp.), were determined as gitogenin 3-O-beta-D-xylopyranosyl-(1-->6)-beta-D-glucopyranoside, sarsasapogenin 3-O-beta-D-xylopyranosyl-(1-->6)-beta-D-glucopyranoside, and gitogenin 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranoside, respectively. Fenugreek saponin I (1) and dioscin (9) caused ca. 12.5- and 17.7-fold stimulation of release, respectively, of rat growth hormone from rat pituitary cells, whereas gitogenin (5) showed moderate activity. To our knowledge, this is the first study to demonstrate that steroidal saponins stimulate rat growth-hormone release in rat pituitary cells. PMID:18816528

  16. Effect of growth hormone-releasing factor on growth hormone release in children with radiation-induced growth hormone deficiency

    SciTech Connect

    Lustig, R.H.; Schriock, E.A.; Kaplan, S.L.; Grumbach, M.M.

    1985-08-01

    Five male children who received cranial irradiation for extrahypothalamic intracranial neoplasms or leukemia and subsequently developed severe growth hormone (GH) deficiency were challenged with synthetic growth hormone-releasing factor (GRF-44), in an attempt to distinguish hypothalamic from pituitary dysfunction as a cause of their GH deficiency, and to assess the readily releasable GH reserve in the pituitary. In response to a pulse of GRF-44 (5 micrograms/kg intravenously), mean peak GH levels rose to values higher than those evoked by the pharmacologic agents L-dopa or arginine (6.4 +/- 1.3 ng/mL v 1.5 +/- 0.4 ng/mL, P less than .05). The peak GH value occurred at a mean of 26.0 minutes after administration of GRF-44. These responses were similar to those obtained in children with severe GH deficiency due to other etiologies (peak GH 6.3 +/- 1.7 ng/mL, mean 28.0 minutes). In addition, there was a trend toward an inverse relationship between peak GH response to GRF-44 and the postirradiation interval. Prolactin and somatomedin-C levels did not change significantly after the administration of a single dose of GRF-44. The results of this study support the hypothesis that cranial irradiation in children can lead to hypothalamic GRF deficiency secondary to radiation injury of hypothalamic GRF-secreting neurons. This study also lends support to the potential therapeutic usefulness of GRF-44 or an analog for GH deficiency secondary to cranial irradiation.

  17. Interactions of growth hormone secretagogues and growth hormone-releasing hormone/somatostatin.

    PubMed

    Tannenbaum, G S; Bowers, C Y

    2001-02-01

    The class of novel synthetic compounds termed growth hormone secretagogues (GHSs) act in the hypothalamus through, as yet, unknown pathways. We performed physiologic and histochemical studies to further understand how the GHS system interacts with the well-established somatostatin (SRIF)/growth hormone-releasing hormone (GHRH) neuroendocrine system for regulating pulsatile GH secretion. Comparison of the GH-releasing activities of the hexapeptide growth hormone-releasing peptide-6 (GHRP-6) and GHRH administered intravenously to conscious adult male rats showed that the pattern of GH responsiveness to GHRP-6 was markedly time-dependent, similar to that observed with GHRH. Immunoneutralization of endogenous SRIF reversed the blunted GH response to GHRP-6 at trough times, suggesting that GHRP-6 neither disrupts nor inhibits the cyclical release of endogenous hypothalamic SRIF. By striking contrast, passive immunization with anti-GHRH serum virtually obliterated the GH responses to GHRP-6, irrespective of the time of administration. These findings suggest that the GHSs do not act by altering SRIF release but, rather, stimulate GH release via GHRH-dependent pathways. Our dual chromogenic and autoradiographic in situ hybridization experiments revealed that a subpopulation of GHRH mRNA-containing neurons in the arcuate (Arc) nucleus and ventromedial nucleus (VMN) of the hypothalamus expressed the GHS receptor (GHS-R) gene. These results provide strong anatomic evidence that GHSs may directly stimulate GHRH release into hypophyseal portal blood, and thereby influence GH secretion, through interaction with the GHS-R on GHRH- containing neurons. Altogether, these findings support the notion that an additional neuroendocrine pathway may exist to regulate pulsatile GH secretion, possibly through the influence of the newly discovered GHS natural peptide, ghrelin. PMID:11322498

  18. Algorithmic complexity of growth hormone release in humans

    SciTech Connect

    Prank, K.; Wagner, M.; Brabant, G.

    1996-12-31

    Most hormones are secreted in an pulsatile rather than in a constant manner. This temporal pattern of pulsatile hormone release plays an important role in the regulation of cellular function and structure. In healthy humans growth hormone (GH) secretion is characterized by distinct pulses whereas patients bearing a GH producing tumor accompanied with excessive secretion (acromegaly) exhibit a highly irregular pattern of GH release. It has been hypothesized that this highly disorderly pattern of GH release in acromegaly arises from random events in the GH-producing tumor under decreased normal control of GH secretion. Using a context-free grammar complexity measure (algorithmic complexity) in conjunction with random surrogate data sets we demonstrate that the temporal pattern of GH release in acromegaly is not significantly different from a variety of stochastic processes. In contrast, normal subjects clearly exhibit deterministic structure in their temporal patterns of GH secretion. Our results support the hypothesis that GH release in acromegaly is due to random events in the GH-producing tumorous cells which might become independent from hypothalamic regulation. 17 refs., 1 fig., 2 tabs.

  19. The positive effects of growth hormone-releasing peptide-6 on weight gain and fat mass accrual depend on the insulin/glucose status.

    PubMed

    Granado, Miriam; García-Cáceres, Cristina; Frago, Laura M; Argente, Jesús; Chowen, Julie A

    2010-05-01

    Ghrelin and GH secretagogues, including GH-releasing peptide (GHRP)-6, stimulate food intake and adiposity. Because insulin modulates the hypothalamic response to GH secretagogues and acts synergistically with ghrelin on lipogenesis in vitro, we analyzed whether insulin plays a role in the metabolic effects of GHRP-6 in vivo. Streptozotocin-induced diabetic rats received saline, GHRP-6, insulin, or insulin plus GHRP-6 once daily for 8 wk. Rats receiving saline suffered hyperglycemia, hyperphagia, polydipsia, and weight loss. Insulin, but not GHRP-6, improved these parameters (P < 0.001 for all), as well as the diabetes-induced increase in hypothalamic mRNA levels of neuropeptide Y and agouti-related peptide and decrease in proopiomelanocortin. Cocaine amphetamine-related transcript mRNA levels were also reduced in diabetic rats, with GHRP-6 inducing a further decrease (P < 0.03) and insulin an increase. Diabetic rats receiving insulin plus GHRP-6 gained more weight and had increased epididymal fat mass and serum leptin levels compared with all other groups (P < 0.001). In epididymal adipose tissue, diabetic rats injected with saline had smaller adipocytes (P < 0.001), decreased fatty acid synthase (FAS; P < 0.001), and glucose transporter-4 (P < 0.001) and increased hormone sensitive lipase (P < 0.001) and proliferator-activated receptor-gamma mRNA levels (P < 0.01). Insulin normalized these parameters to control values. GHRP-6 treatment increased FAS and glucose transporter-4 gene expression and potentiated insulin's effect on epididymal fat mass, adipocyte size (P < 0.001), FAS (P < 0.001), and glucose transporter-4 (P < 0.05). In conclusion, GHRP-6 and insulin exert an additive effect on weight gain and visceral fat mass accrual in diabetic rats, indicating that some of GHRP-6's metabolic effects depend on the insulin/glucose status. PMID:20219977

  20. Structural study of human growth hormone-releasing factor fragment (1?29) by vibrational spectroscopy

    NASA Astrophysics Data System (ADS)

    Carmona, P.; Molina, M.; Lasagabaster, A.

    1995-05-01

    The conformational structure of fragment 1-29 of human growth hormone releasing factor, hGHRF (1-29), in aqueous solution and in the solid state is investigated by infrared and Raman spectroscopy. The polypeptide backbone is found to be unordered in the solid state. However, the spectra of the peptide prepared as 5% (w/w) aqueous solutions show that approximately 28% of the peptide is involved in intermolecular β-sheet aggregation. The remainder of the peptide exists largely as disordered and β-sheet conformations with a small portion of α-helices. Tyrosine residues are found to be exposed to the solvent. The secondary structures are quantitatively examined through infrared spectroscopy, the conformational percentages being near those obtained by HONDAet al. [ Biopolymers31, 869 (1991)] using circular dichroism. The fast hydrogen/deuterium exchange in peptide groups and the absence of any NMR sign indicative of ordered structure [ G. M. CLOREet al., J. Molec. Biol.191, 553 (1986)] support that the solution conformations of the non-aggregated peptide interconvert in dynamic equilibrium. Some physiological advantages that may derive from this conformational flexibility are also discussed

  1. Peripheral activities of growth hormone-releasing hormone.

    PubMed

    Granata, R

    2016-07-01

    Growth hormone (GH)-releasing hormone (GHRH) is produced by the hypothalamus and stimulates GH synthesis and release in the anterior pituitary gland. In addition to its endocrine role, GHRH exerts a wide range of extrapituitary effects which include stimulation of cell proliferation, survival and differentiation, and inhibition of apoptosis. Accordingly, expression of GHRH, as well as the receptor GHRH-R and its splice variants, has been demonstrated in different peripheral tissues and cell types. Among the direct peripheral activities, GHRH regulates pancreatic islet and β-cell survival and function and endometrial cell proliferation, promotes cardioprotection and wound healing, influences the immune and reproductive systems, reduces inflammation, indirectly increases lifespan and adiposity and acts on skeletal muscle cells to inhibit cell death and atrophy. Therefore, it is becoming increasingly clear that GHRH exerts important extrapituitary functions, suggesting potential therapeutic use of the peptide and its analogs in a wide range of medical settings. PMID:26891937

  2. Discovery of growth hormone-releasing hormones and receptors in nonmammalian vertebrates

    PubMed Central

    Lee, Leo T. O.; Siu, Francis K. Y.; Tam, Janice K. V.; Lau, Ivy T. Y.; Wong, Anderson O. L.; Lin, Marie C. M.; Vaudry, Hubert; Chow, Billy K. C.

    2007-01-01

    In mammals, growth hormone-releasing hormone (GHRH) is the most important neuroendocrine factor that stimulates the release of growth hormone (GH) from the anterior pituitary. In nonmammalian vertebrates, however, the previously named GHRH-like peptides were unable to demonstrate robust GH-releasing activities. In this article, we provide evidence that these GHRH-like peptides are homologues of mammalian PACAP-related peptides (PRP). Instead, GHRH peptides encoded in cDNAs isolated from goldfish, zebrafish, and African clawed frog were identified. Moreover, receptors specific for these GHRHs were characterized from goldfish and zebrafish. These GHRHs and GHRH receptors (GHRH-Rs) are phylogenetically and structurally more similar to their mammalian counterparts than the previously named GHRH-like peptides and GHRH-like receptors. Information regarding their chromosomal locations and organization of neighboring genes confirmed that they share the same origins as the mammalian genes. Functionally, the goldfish GHRH dose-dependently activates cAMP production in receptor-transfected CHO cells as well as GH release from goldfish pituitary cells. Tissue distribution studies showed that the goldfish GHRH is expressed almost exclusively in the brain, whereas the goldfish GHRH-R is actively expressed in brain and pituitary. Taken together, these results provide evidence for a previously uncharacterized GHRH-GHRH-R axis in nonmammalian vertebrates. Based on these data, a comprehensive evolutionary scheme for GHRH, PRP-PACAP, and PHI-VIP genes in relation to three rounds of genome duplication early on in vertebrate evolution is proposed. These GHRHs, also found in flounder, Fugu, medaka, stickleback, Tetraodon, and rainbow trout, provide research directions regarding the neuroendocrine control of growth in vertebrates. PMID:17283332

  3. PEGylation of growth hormone-releasing hormone (GRF) analogues.

    PubMed

    Esposito, P; Barbero, L; Caccia, P; Caliceti, P; D'Antonio, M; Piquet, G; Veronese, F M

    2003-09-26

    Synthetically produced GRF1-29 (Sermorelin) has an amino acid composition identical to the N-terminal 29 amino acids sequence of the natural hypothalamic GHRH1-44 (Figure 1). It maintains bioactivity in vitro and is almost equally effective in eliciting secretion of endogenous growth hormone in vivo. The main drawbacks associated with the pharmaceutical use of hGRF1-29 relate to its short half-life in plasma, about 10-20 min in humans, which is caused mostly by renal ultrafiltration and enzymatic degradation at the N terminus. PEGylation has been considered as one valid approach to obtain more stable forms of the peptide, with a longer in vivo half-life and ultimately with increased pharmacodynamic response along the somatotropic axis (endogenous GH, IGF-1 levels). Different PEGylated GRF conjugates were obtained and their bioactivity was tested in vitro and in vivo by monitoring endogenous growth hormone (GH) serum levels after intravenous (i.v.) injection in rats, and intravenous and subcutaneous (s.c.) injection in pigs. It was found that GRF-PEG conjugates are able to bind and activate the human GRF receptor, although with different potency. The effect of PEG molecular weight, number of PEG chains bound and position of PEGylation site on GRF activity were investigated. Mono-PEGylated isomers with a PEG5000 polymer chain linked to Lys 12 or Lys 21 residues, showed high biological activity in vitro, which is similar to that of hGRF1-29, and a higher pharmacodynamic response as compared to unmodified GRF molecule. PMID:14499707

  4. Lipopeptide antagonists of growth hormone-releasing hormone with improved antitumor activities.

    PubMed

    Zarandi, Marta; Varga, Jozsef L; Schally, Andrew V; Horvath, Judit E; Toller, Gabor L; Kovacs, Magdolna; Letsch, Markus; Groot, Kate; Armatis, Patricia; Halmos, Gabor

    2006-03-21

    Antagonists of growth hormone-releasing hormone (GHRH) synthesized previously inhibit proliferation of various human cancers, but derivatisation with fatty acids could enhance their clinical efficacy. We synthesized a series of antagonists of GHRH(1-29)NH(2) acylated at the N terminus with monocarboxylic or alpha,omega-dicarboxylic acids containing six to sixteen carbon atoms. These peptides are analogs of prior potent antagonists JV-1-36, JV-1-38, and JV-1-65 with phenylacetyl group at their N terminus. Several new analogs, including MZ-J-7-46 and MZ-J-7-30, more effectively inhibited GHRH-induced GH release in vitro in a superfused rat pituitary system than their parent compound JV-1-36 and had increased binding affinities to rat pituitary GHRH receptors, but they showed weaker inhibition of GH release in vivo than JV-1-36. All antagonists acylated with fatty acids containing 8-14 carbon atoms inhibited the proliferation of MiaPaCa-2 human pancreatic cancer cells in vitro better than JV-1-36 or JV-1-65. GHRH antagonist MZ-J-7-114 (5 mug/day) significantly suppressed the growth of PC-3 human androgen-independent prostate cancers xenografted into nude mice and reduced serum IGF-I levels, whereas antagonist JV-1-38 had no effect at the dose of 10 mug/day. GHRH antagonists including MZ-J-7-46 and MZ-J-7-114 acylated with octanoic acid and MZ-J-7-30 and MZ-J-7-110 acylated with 1,12-dodecanedicarboxylic acid represent relevant improvements over earlier antagonists. These and previous results suggest that this class of GHRH antagonists might be effective in the treatment of various cancers. PMID:16537407

  5. Lipopeptide antagonists of growth hormone-releasing hormone with improved antitumor activities

    PubMed Central

    Zarandi, Marta; Varga, Jozsef L.; Schally, Andrew V.; Horvath, Judit E.; Toller, Gabor L.; Kovacs, Magdolna; Letsch, Markus; Groot, Kate; Armatis, Patricia; Halmos, Gabor

    2006-01-01

    Antagonists of growth hormone-releasing hormone (GHRH) synthesized previously inhibit proliferation of various human cancers, but derivatisation with fatty acids could enhance their clinical efficacy. We synthesized a series of antagonists of GHRH(1-29)NH2 acylated at the N terminus with monocarboxylic or α,ω-dicarboxylic acids containing six to sixteen carbon atoms. These peptides are analogs of prior potent antagonists JV-1-36, JV-1-38, and JV-1-65 with phenylacetyl group at their N terminus. Several new analogs, including MZ-J-7-46 and MZ-J-7-30, more effectively inhibited GHRH-induced GH release in vitro in a superfused rat pituitary system than their parent compound JV-1-36 and had increased binding affinities to rat pituitary GHRH receptors, but they showed weaker inhibition of GH release in vivo than JV-1-36. All antagonists acylated with fatty acids containing 8–14 carbon atoms inhibited the proliferation of MiaPaCa-2 human pancreatic cancer cells in vitro better than JV-1-36 or JV-1-65. GHRH antagonist MZ-J-7-114 (5 μg/day) significantly suppressed the growth of PC-3 human androgen-independent prostate cancers xenografted into nude mice and reduced serum IGF-I levels, whereas antagonist JV-1-38 had no effect at the dose of 10 μg/day. GHRH antagonists including MZ-J-7-46 and MZ-J-7-114 acylated with octanoic acid and MZ-J-7-30 and MZ-J-7-110 acylated with 1,12-dodecanedicarboxylic acid represent relevant improvements over earlier antagonists. These and previous results suggest that this class of GHRH antagonists might be effective in the treatment of various cancers. PMID:16537407

  6. Interaction between a growth-hormone releasing hexapeptide and phospholipids spread as monolayers at the air/water interface.

    PubMed

    Issaurat, B; Teissié, J

    1988-10-20

    The interaction between a growth-hormone releasing hexapeptide and phospholipids was studied on mixed monolayers models by means of surface fluorescence. When in a monolayer this hexapeptide which contains two tryptophan molecules was observed to fluoresce. Isothermal compression experiments showed that the complex was destroyed upon compression in the case of phosphatidylethanolamine. With phosphatidylglycerol it was observed to be stable but a dramatic reversible decrease in emission was observed at high surface pressure. This is indicative of a reversible change in the organization of the peptide-phospholipid complex. These observations indicate that, in the complex, hydrophobic interactions were weak but electrostatic ones, when present, were strong enough to maintain the GHRP attached to the monolayer and not to destabilize it. The integrity of the lipid monolayer appeared not to be affected by the peptide. PMID:3179304

  7. Synthesis and in vitro anti-cancer evaluation of luteinizing hormone-releasing hormone-conjugated peptide.

    PubMed

    Deng, Xin; Qiu, Qianqian; Ma, Ke; Huang, Wenlong; Qian, Hai

    2015-11-01

    Luteinizing hormone-releasing hormone (LHRH) is a decapeptide hormone released from the hypothalamus and shows high affinity binding to the LHRH receptors. It is reported that several cancer cells also express LHRH receptors such as breast, ovarian, prostatic, bladder and others. In this study, we linked B1, an anti-cancer peptide, to LHRH and its analogs to improve the activity against cancer cells with LHRH receptor. Biological evaluation revealed that TB1, the peptide contains triptorelin sequence, present favorable anti-cancer activity as well as plasma stability. Further investigations disclosed that TB1 trigger apoptosis by activating the mitochondria-cytochrome c-caspase apoptotic pathway, it also exhibited the anti-migratory effect on cancer cells. PMID:26058357

  8. Identification of the growth hormone-releasing hormone analogue [Pro1, Val14]-hGHRH with an incomplete C-term amidation in a confiscated product.

    PubMed

    Esposito, Simone; Deventer, Koen; Van Eenoo, Peter

    2014-01-01

    In this work, a modified version of the 44 amino acid human growth hormone-releasing hormone (hGHRH(1-44)) containing an N-terminal proline extension, a valine residue in position 14, and a C-terminus amidation (sequence: PYADAIFTNSYRKVVLGQLSARKLLQDIMSRQQGESNQERGARARL-NH2 ) has been identified in a confiscated product by liquid chromatography-high resolution mass spectrometry (LC-HRMS). Investigation of the product suggests also an incomplete C-term amidation. Similarly to other hGHRH analogues, available in black markets, this peptide can potentially be used as performance-enhancing drug due to its growth hormone releasing activity and therefore it should be considered as a prohibited substance in sport. Additionally, the presence of partially amidated molecule reveals the poor pharmaceutical quality of the preparation, an aspect which represents a big concern for public health as well. PMID:25283153

  9. Effects of plasmid-mediated growth hormone-releasing hormone in severely debilitated dogs with cancer.

    PubMed

    Draghia-Akli, Ruxandra; Hahn, Kevin A; King, Glen K; Cummings, Kathleen K; Carpenter, Robert H

    2002-12-01

    Cachexia is a common manifestation of late stage malignancy and is characterized by anemia, anorexia, muscle wasting, loss of adipose tissue, and fatigue. Although cachexia is disabling and can diminish the life expectancy of cancer patients, there are still no effective therapies for this condition. We have examined the feasibility of using a myogenic plasmid to express growth hormone-releasing hormone (GHRH) in severely debilitated companion dogs with naturally occurring tumors. At a median of 16 days after intramuscular delivery of the plasmid, serum concentrations of insulin-like growth factor I (IGF-I), a measure of GHRH activity, were increased in 12 of 16 dogs (P < 0.01). These increases ranged from 21 to 120% (median, 49%) of the pretreatment values and were generally sustained or higher on the final evaluation. Anemia resolved posttreatment, as indicated by significant increases in mean red blood cell count, hematocrit, and hemoglobin concentrations, and there was also a significant rise in the percentage of circulating lymphocytes. Treated dogs maintained their weights over the 56-day study and did not show any adverse effects from the GHRH gene transfer. We conclude that intramuscular injection of a GHRH-expressing plasmid is both safe and capable of stimulating the release of growth hormone and IGF-I in large animals. The observed anabolic responses to a single dose of this therapy might be beneficial in patients with cancer-associated anemia and cachexia. PMID:12498779

  10. Structural and Functional Divergence of Growth Hormone-Releasing Hormone Receptors in Early Sarcopterygians: Lungfish and Xenopus

    PubMed Central

    Tam, Janice K. V.; Chow, Billy K. C.; Lee, Leo T. O.

    2013-01-01

    The evolutionary trajectories of growth hormone-releasing hormone (GHRH) receptor remain enigmatic since the discovery of physiologically functional GHRH-GHRH receptor (GHRHR) in non-mammalian vertebrates in 2007. Interestingly, subsequent studies have described the identification of a GHRHR2 in chicken in addition to the GHRHR and the closely related paralogous receptor, PACAP-related peptide (PRP) receptor (PRPR). In this article, we provide information, for the first time, on the GHRHR in sarcopterygian fish and amphibians by the cloning and characterization of GHRHRs from lungfish (P. dolloi) and X. laevis. Sequence alignment and phylogenetic analyses demonstrated structural resemblance of lungfish GHRHR to their mammalian orthologs, while the X. laevis GHRHR showed the highest homology to GHRHR2 in zebrafish and chicken. Functionally, lungfish GHRHR displayed high affinity towards GHRH in triggering intracellular cAMP and calcium accumulation, while X. laevis GHRHR2 was able to react with both endogenous GHRH and PRP. Tissue distribution analyses showed that both lungfish GHRHR and X. laevis GHRHR2 had the highest expression in brain, and interestingly, X. laevis GHRHR2 also had high abundance in the reproductive organs. These findings, together with previous reports, suggest that early in the Sarcopterygii lineage, GHRHR and PRPR have already established diverged and specific affinities towards their cognate ligands. GHRHR2, which has only been found in xenopus, zebrafish and chicken hitherto, accommodates both GHRH and PRP. PMID:23308232

  11. Structural and functional divergence of growth hormone-releasing hormone receptors in early sarcopterygians: lungfish and Xenopus.

    PubMed

    Tam, Janice K V; Chow, Billy K C; Lee, Leo T O

    2013-01-01

    The evolutionary trajectories of growth hormone-releasing hormone (GHRH) receptor remain enigmatic since the discovery of physiologically functional GHRH-GHRH receptor (GHRHR) in non-mammalian vertebrates in 2007. Interestingly, subsequent studies have described the identification of a GHRHR(2) in chicken in addition to the GHRHR and the closely related paralogous receptor, PACAP-related peptide (PRP) receptor (PRPR). In this article, we provide information, for the first time, on the GHRHR in sarcopterygian fish and amphibians by the cloning and characterization of GHRHRs from lungfish (P. dolloi) and X. laevis. Sequence alignment and phylogenetic analyses demonstrated structural resemblance of lungfish GHRHR to their mammalian orthologs, while the X. laevis GHRHR showed the highest homology to GHRHR(2) in zebrafish and chicken. Functionally, lungfish GHRHR displayed high affinity towards GHRH in triggering intracellular cAMP and calcium accumulation, while X. laevis GHRHR(2) was able to react with both endogenous GHRH and PRP. Tissue distribution analyses showed that both lungfish GHRHR and X. laevis GHRHR(2) had the highest expression in brain, and interestingly, X. laevis(GHRHR2) also had high abundance in the reproductive organs. These findings, together with previous reports, suggest that early in the Sarcopterygii lineage, GHRHR and PRPR have already established diverged and specific affinities towards their cognate ligands. GHRHR(2), which has only been found in xenopus, zebrafish and chicken hitherto, accommodates both GHRH and PRP. PMID:23308232

  12. Long-term effects of plasmid-mediated growth hormone releasing hormone in dogs.

    PubMed

    Tone, Catherine M; Cardoza, Dawn M; Carpenter, Robert H; Draghia-Akli, Ruxandra

    2004-05-01

    Geriatric and cancer-afflicted patients often experience decreased quality of life with cachexia, anemia, anorexia, and decreased activity level. We have studied the possibility that a myogenic plasmid that expresses growth hormone releasing hormone (GHRH) can prevent and/or treat these conditions. We administered plasmid to 17 geriatric and five cancer-afflicted companion dogs with an average age of 10.5+/-1.0 and 11.3+/-0.6 years at enrollment, respectively. Effects of the treatment were documented for at least 180 days post-treatment, with 10 animals followed for more than 1 year post-treatment, on average 444+/-40 days. Treated dogs showed increased IGF-I levels, and increases in scores for weight, activity level, exercise tolerance, and appetite. No adverse effects associated with the GHRH plasmid treatment were found. Most importantly, the overall assessment of the quality of life of the treated animals increased. Hematological parameters such as red blood cell count, hematocrit, and hemoglobin concentrations were improved and maintained within their normal ranges. We conclude that intramuscular injection of a GHRH-expressing plasmid is both safe and capable of improving the quality of life in animals for an extended period of time in the context of aging and disease. The observed anabolic and hematological responses to a single dose of this plasmid treatment may also be beneficial in geriatric patients or patients with cancer-associated anemia and/or cachexia. PMID:15073611

  13. Growth hormone-releasing hormone (GHRH) polymorphisms associated with carcass traits of meat in Korean cattle

    PubMed Central

    Cheong, Hyun Sub; Yoon, Du-Hak; Kim, Lyoung Hyo; Park, Byung Lae; Choi, Yoo Hyun; Chung, Eui Ryong; Cho, Yong Min; Park, Eng Woo; Cheong, Il-Cheong; Oh, Sung-Jong; Yi, Sung-Gon; Park, Taesung; Shin, Hyoung Doo

    2006-01-01

    Background Cold carcass weight (CW) and longissimus muscle area (EMA) are the major quantitative traits in beef cattle. In this study, we found several polymorphisms of growth hormone-releasing hormone (GHRH) gene and examined the association of polymorphisms with carcass traits (CW and EMA) in Korean native cattle (Hanwoo). Results By direct DNA sequencing in 24 unrelated Korean cattle, we identified 12 single nucleotide polymorphisms within the 9 kb full gene region, including the 1.5 kb promoter region. Among them, six polymorphic sites were selected for genotyping in our beef cattle (n = 428) and five marker haplotypes (frequency > 0.1) were identified. Statistical analysis revealed that -4241A>T showed significant associations with CW and EMA. Conclusion Our findings suggest that polymorphisms in GHRH might be one of the important genetic factors that influence carcass yield in beef cattle. Sequence variation/haplotype information identified in this study would provide valuable information for the production of a commercial line of beef cattle. PMID:16749938

  14. Myogenic expression of an injectable protease-resistant growth hormone-releasing hormone augments long-term growth in pigs

    NASA Technical Reports Server (NTRS)

    Draghia-Akli, R.; Fiorotto, M. L.; Hill, L. A.; Malone, P. B.; Deaver, D. R.; Schwartz, R. J.

    1999-01-01

    Ectopic expression of a new serum protease-resistant porcine growth hormone-releasing hormone, directed by an injectable muscle-specific synthetic promoter plasmid vector (pSP-HV-GHRH), elicits growth in pigs. A single 10 mg intramuscular injection of pSP-HV-GHRH DNA followed by electroporation in three-week-old piglets elevated serum GHRH levels by twofold to fourfold, enhanced growth hormone secretion, and increased serum insulin-like growth factor-I by threefold to sixfold over control pigs. After 65 days the average body weight of the pigs injected with pSP-HV-GHRH was approximately 37% greater than the placebo-injected controls and resulted in a significant reduction in serum urea concentration, indicating a decrease in amino acid catabolism. Evaluation of body composition indicated a uniform increase in mass, with no organomegaly or associated pathology.

  15. Agonist of growth hormone-releasing hormone reduces pneumolysin-induced pulmonary permeability edema

    PubMed Central

    Lucas, Rudolf; Sridhar, Supriya; Rick, Ferenc G.; Gorshkov, Boris; Umapathy, Nagavedi S.; Yang, Guang; Oseghale, Aluya; Verin, Alexander D.; Chakraborty, Trinad; Matthay, Michael A.; Zemskov, Evgeny A.; White, Richard; Block, Norman L.; Schally, Andrew V.

    2012-01-01

    Aggressive treatment with antibiotics in patients infected with Streptococcus pneumoniae induces release of the bacterial virulence factor pneumolysin (PLY). Days after lungs are sterile, this pore-forming toxin can still induce pulmonary permeability edema in patients, characterized by alveolar/capillary barrier dysfunction and impaired alveolar liquid clearance (ALC). ALC is mainly regulated through Na+ transport by the apically expressed epithelial sodium channel (ENaC) and the basolaterally expressed Na+/K+-ATPase in type II alveolar epithelial cells. Because no standard treatment is currently available to treat permeability edema, the search for novel therapeutic candidates is of high priority. We detected mRNA expression for the active receptor splice variant SV1 of the hypothalamic polypeptide growth hormone-releasing hormone (GHRH), as well as for GHRH itself, in human lung microvascular endothelial cells (HL-MVEC). Therefore, we have evaluated the effect of the GHRH agonist JI-34 on PLY-induced barrier and ALC dysfunction. JI-34 blunts PLY-mediated endothelial hyperpermeability in monolayers of HL-MVEC, in a cAMP-dependent manner, by means of reducing the phosphorylation of myosin light chain and vascular endothelial (VE)-cadherin. In human airway epithelial H441 cells, PLY significantly impairs Na+ uptake, but JI-34 restores it to basal levels by means of increasing cAMP levels. Intratracheal instillation of PLY into C57BL6 mice causes pulmonary alveolar epithelial and endothelial hyperpermeability as well as edema formation, all of which are blunted by JI-34. These findings point toward a protective role of the GHRH signaling pathway in PLY-induced permeability edema. PMID:22308467

  16. Increased activity of antagonists of growth hormone-releasing hormone substituted at positions 8, 9, and 10

    PubMed Central

    Varga, Jozsef L.; Schally, Andrew V.; Horvath, Judit E.; Kovacs, Magdolna; Halmos, Gabor; Groot, Kate; Toller, Gabor L.; Rekasi, Zoltan; Zarandi, Marta

    2004-01-01

    Antagonists of human growth hormone-releasing hormone (hGHRH) with increased potency and improved enzymatic and chemical stability are needed for potential clinical applications. We synthesized 21 antagonistic analogs of hGHRH(1-29)NH2, substituted at positions 8, 9, and 10 of the common core sequence {phenylacetyl-Tyr1, d-Arg2,28, para-chloro-phenylalanine 6, Arg9/homoarginine 9, Tyr10/O-methyltyrosine 10, α-aminobutyric acid 15, norleucine 27, Har29} hGHRH(1-29)NH2. Inhibitory effects on hGHRH-induced GH release were evaluated in vitro in a superfused rat pituitary system, as well as in vivo after i.v. injection into rats. The binding affinities of the peptides to pituitary GHRH receptors were also determined. Introduction of para-amidinophenylalanine 10 yielded antagonists JV-1-62 and -63 with the highest activities in vitro and lowest receptor dissociation constants (Ki = 0.057-0.062 nM). Antagonists JV-1-62 and -63 also exhibited the strongest effect in vivo, significantly (P < 0.05-0.001) inhibiting hGHRH-induced GH release for at least 1 h. Para-aminophenylalanine 10 and O-ethyltyrosine 10 substitutions yielded antagonists potent in vitro, but His10, 3,3′-diphenylalanine 10, 2-naphthylalanine 10, and cyclohexylalanine 10 modifications were detrimental. Antagonists containing citrulline 9 (in MZ-J-7-72), amidinophenylalanine 9 (in JV-1-65), His9, d-Arg9, citrulline 8, Ala8, d-Ala8, or α-aminobutyric acid 8 substituents also had high activity and receptor affinity in vitro. However, in vitro potencies of analogs with substitution in position 9 correlated poorly with acute endocrine effects in vivo, as exemplified by the weak and/or short inhibitory actions of antagonists JV-1-65 and MZ-J-7-72 on GH release in vivo. Nevertheless, antagonist JV-1-65 was more potent than JV-1-63 in tests on inhibition of the growth of human prostatic and lung cancer lines xenografted into nude mice. This indicates that oncological activity may be based on several mechanisms

  17. Synthesis and biological evaluation of antagonists of growth hormone-releasing hormone with high and protracted in vivo activities

    PubMed Central

    Varga, József L.; Schally, Andrew V.; Csernus, Valér J.; Zarándi, Márta; Halmos, Gábor; Groot, Kate; Rékási, Zoltán

    1999-01-01

    Some antagonists of human growth hormone-releasing hormone (hGH-RH) synthesized previously were shown to inhibit in vivo proliferation of various human cancers in nude mice. However, the activity of these analogs requires an increase to assure clinical efficacy. In an attempt to prepare hGH-RH antagonists with a high and protracted activity, we synthesized and biologically tested 22 antagonistic analogs of hGH-RH(1–29)NH2. The ability of the antagonists to inhibit hGH-RH-induced GH release was evaluated in vitro in a superfused rat pituitary system, as well as in vivo after i.v. injection into rats. The binding affinity of the peptides to GH-RH receptors also was determined. All antagonistic analogs had the common core sequence [PhAc-Tyr1,d-Arg2, Phe(4-Cl)6 (para-chlorophenylalanine), Abu15 (α-aminobutyric acid),Nle27]hGH-RH(1–29)NH2 and contained Arg, d-Arg, homoarginine (Har), norleucine (Nle), and other substitutions. The following analogs were determined to have a high and/or protracted antagonistic activity: [PhAc-Tyr1,d-Arg2,Phe(4-Cl)6,Arg9,Abu15,Nle27,d-Arg29]hGH-RH(1–29)NH2 (JV-1–10), [PhAc-Tyr1,d-Arg2,Phe(4-Cl)6,Abu15,Nle27,d-Arg28,Har29]hGH-RH(1–29)NH2 (MZ-6–55), [PhAc-Tyr1,d-Arg2,Phe(4-Cl)6,Arg9,Abu15,Nle27,d-Arg28,Har29]hGH-RH(1–29)NH2 (JV-1–36), and [PhAc-Tyr1,d-Arg2,Phe(4-Cl)6,Har9,Tyr(Me)10,Abu15,Nle27,d-Arg28,Har29]hGH-RH(1–29)NH2 (JV-1–38). Among the peptides tested, analog JV-1–36 showed the highest GH-RH antagonistic activity in vitro and also induced a strong and prolonged inhibition of GH release in vivo for at least 30 min. The antagonist JV-1–38 was slightly less potent than JV-1–36 both in vitro and in vivo but proved to be very long-acting in vivo, suppressing the GH-RH-induced GH release even after 60 min. High and protracted in vivo activities of these antagonists indicate an improvement over earlier GH-RH analogs. Some of these hGH-RH antagonists could find clinical applications in the treatment of cancers

  18. Effect of hypophysectomy and growth hormone replacement on hypothalamic growth hormone-releasing factor messenger ribonucleic Acid levels.

    PubMed

    Eccleston, L M; Powell, J F; Clayton, R N

    1991-12-01

    Abstract The mechanisms by which the pituitary gland, and growth hormone (GH) in particular, affect growth hormone-releasing factor (GRF) gene expression have been addressed using the technique of in situ hybridization. Anatomically matched sections through the mediobasal hypothalamus of control and hypophysectomized male rats, with or without GH hormone replacement, were analysed to obtain information on GRF mRNA levels within the arcuate nucleus and around the ventromedial hypothalamus. Hypophysectomy resulted in a 70% increase in the amount of GRF mRNA per cell (P<0.001), within neurons in the arcuate nucleus. GH replacement and T4 replacement separately partially attenuated this increase (GH replacement P< 0.001 versus hypophysectomy, T4 replacement P<0.05 versus hypophysectomy). Additionally, after hypophysectomy there was an 80% increase in the number of cells expressing the GRF gene in neurons around the ventromedial hypothalamus, when compared to shamoperated controls (P<0.01). Both GH and T4 replacement separately partially attenuated this phenomenon (P<0.01 versus hypophysectomized animals). Hypothyroidism alone did not affect GRF mRNA levels in either the arcuate nucleus or in the area surrounding the ventromedial hypothalamus. These results show that hypophysectomy increases GRF mRNA levels in two separate ways: by increasing the amount of mRNA produced per cell within the arcuate nucleus, and by increasing the number of cells expressing the gene in the area surrounding the ventromedial hypothalamus. This increase in the number of GRF mRNA-containing cells after hypophysectomy could result from the recruitment of neurons which previously did not express the GRF gene, and may reflect the plasticity of the adult central nervous system in response to a changing endocrine environment. This could represent part of a sensor mechanism to drive the production of GRF in the arcuate nucleus in response to extreme disruption of the GRF/ GH feedback loop. PMID

  19. Inhibition by somatostatin (growth-hormone release-inhibiting hormone, GH-RIH) of gastric acid and pepsin and G-cell release of gastrin.

    PubMed Central

    Barros D'sa, A A; Bloom, S R; Baron, J H

    1978-01-01

    Somatostatin (cyclic growth-hormone release-inhibiting hormone--GH-RIH) was infused into dogs with gastric fistulae. Somatostatin inhibited gastric acid response to four gastric stimulants--insulin, food, histamine, and pentagastrin. Histamine- and pentagastrin-stimulated pepsins were inhibited similarly to inhibition of acid. Somatostatin inhibited the gastrin response to insulin and food. PMID:348581

  20. Growth Hormone Releasing Hormone (GHRH) Signaling Modulates Intermittent Hypoxia-Induced Oxidative Stress and Cognitive Deficits In Mouse

    PubMed Central

    Nair, Deepti; Ramesh, Vijay; Li, Richard C.; Schally, Andrew V.; Gozal, David

    2013-01-01

    Intermittent hypoxia (IH) during sleep, such as occurs in obstructive sleep apnea (OSA), leads to degenerative changes in the hippocampus, and is associated with spatial learning deficits in adult mice. In both patients and murine models of OSA, the disease is associated with suppression of growth hormone (GH) secretion, which is actively involved in the growth, development and function of the central nervous system (CNS). Recent work showed that exogenous GH therapy attenuated neurocognitive deficits elicited by IH during sleep in rats. Here we show that administration of the Growth Hormone Releasing Hormone (GHRH) agonist JI-34 attenuates IH-induced neurocognitive deficits, anxiety, and depression in mice along with reduction in oxidative stress markers such as MDA and 8-OHDG, and increases in HIF-1α DNA binding and up-regulation of IGF-1 and erythropoietin expression. In contrast, treatment with a GHRH antagonist (MIA-602) during intermittent hypoxia did not affect any of the IH-induced deleterious effects in mice. Thus, exogenous GHRH administered as the formulation of a GHRH agonist may provide a viable therapeutic intervention to protect IH-vulnerable brain regions from OSA-associated neurocognitive dysfunction. PMID:23815362

  1. Growth hormone-releasing hormone (GHRH) antagonists inhibit the proliferation of androgen-dependent and -independent prostate cancers.

    PubMed

    Letsch, Markus; Schally, Andrew V; Busto, Rebeca; Bajo, Ana M; Varga, Jozsef L

    2003-02-01

    The antiproliferative effects of an antagonist of growth hormone-releasing hormone (GHRH) JV-1-38 were evaluated in nude mice bearing s.c. xenografts of LNCaP and MDA-PCa-2b human androgen-sensitive and DU-145 androgen-independent prostate cancers. In the androgen-sensitive models, JV-1-38 greatly potentiated the antitumor effect of androgen deprivation induced by surgical castration, but was ineffective when given alone. Thus, in castrated animals bearing MDA-PCa-2b cancers, the administration of JV-1-38 for 35 days virtually arrested tumor growth (94% inhibition vs. intact control, P < 0.01; and 75% vs. castrated control, P < 0.05). The growth of LNCaP tumors was also powerfully suppressed by JV-1-38 combined with castration (83% inhibition vs. intact control, P < 0.01; and 68% vs. castrated control, P < 0.05). However, in androgen-independent DU-145 cancers, JV-1-38 alone could inhibit tumor growth by 57% (P < 0.05) after 45 days. In animals bearing MDA-PCa-2b and LNCaP tumors, the reduction in serum prostate-specific antigen levels, after therapy with JV-1-38, paralleled the decrease in tumor volume. Inhibition of MDA-PCa-2b and DU-145 cancers was associated with the reduction in the expression of mRNA and protein levels of vascular endothelial growth factor. The mRNA expression for GHRH receptor splice variants was found in all these models of prostate cancer. Our results demonstrate that GHRH antagonists inhibit androgen-independent prostate cancers and, after combination with androgen deprivation, also androgen-sensitive tumors. Thus, the therapy with GHRH antagonist could be considered for the management of both androgen-dependent or -independent prostate cancers. PMID:12538852

  2. Growth hormone-releasing hormone (GHRH) antagonists inhibit the proliferation of androgen-dependent and -independent prostate cancers

    PubMed Central

    Letsch, Markus; Schally, Andrew V.; Busto, Rebeca; Bajo, Ana M.; Varga, Jozsef L.

    2003-01-01

    The antiproliferative effects of an antagonist of growth hormone-releasing hormone (GHRH) JV-1-38 were evaluated in nude mice bearing s.c. xenografts of LNCaP and MDA-PCa-2b human androgen-sensitive and DU-145 androgen-independent prostate cancers. In the androgen-sensitive models, JV-1-38 greatly potentiated the antitumor effect of androgen deprivation induced by surgical castration, but was ineffective when given alone. Thus, in castrated animals bearing MDA-PCa-2b cancers, the administration of JV-1-38 for 35 days virtually arrested tumor growth (94% inhibition vs. intact control, P < 0.01; and 75% vs. castrated control, P < 0.05). The growth of LNCaP tumors was also powerfully suppressed by JV-1-38 combined with castration (83% inhibition vs. intact control, P < 0.01; and 68% vs. castrated control, P < 0.05). However, in androgen-independent DU-145 cancers, JV-1-38 alone could inhibit tumor growth by 57% (P < 0.05) after 45 days. In animals bearing MDA-PCa-2b and LNCaP tumors, the reduction in serum prostate-specific antigen levels, after therapy with JV-1-38, paralleled the decrease in tumor volume. Inhibition of MDA-PCa-2b and DU-145 cancers was associated with the reduction in the expression of mRNA and protein levels of vascular endothelial growth factor. The mRNA expression for GHRH receptor splice variants was found in all these models of prostate cancer. Our results demonstrate that GHRH antagonists inhibit androgen-independent prostate cancers and, after combination with androgen deprivation, also androgen-sensitive tumors. Thus, the therapy with GHRH antagonist could be considered for the management of both androgen-dependent or -independent prostate cancers. PMID:12538852

  3. New therapeutic approach to heart failure due to myocardial infarction based on targeting growth hormone-releasing hormone receptor

    PubMed Central

    Schally, Andrew V.; Takeuchi, Lauro M.; Popovics, Petra; Jaszberenyi, Miklos; Vidaurre, Irving; Zarandi, Marta; Cai, Ren-Zhi; Block, Norman L.; Hare, Joshua M.; Rick, Ferenc G.

    2015-01-01

    Background We previously showed that growth hormone-releasing hormone (GHRH) agonists are cardioprotective following myocardial infarction (MI). Here, our aim was to evaluate the in vitro and in vivo activities of highly potent new GHRH agonists, and elucidate their mechanisms of action in promoting cardiac repair. Methods and Results H9c2 cells were cultured in serum-free medium, mimicking nutritional deprivation. GHRH agonists decreased calcium influx and significantly improved cell survival. Rats with cardiac infarction were treated with GHRH agonists or placebo for four weeks. MI size was reduced by selected GHRH agonists (JI-38, MR-356, MR-409); this accompanied an increased number of cardiac c-kit+ cells, cellular mitotic divisions, and vascular density. One week post-MI, MR-409 significantly reduced plasma levels of IL-2, IL-6, IL-10 and TNF-α compared to placebo. Gene expression studies revealed favorable outcomes of MR-409 treatment partially result from inhibitory activity on pro-apoptotic molecules and pro-fibrotic systems, and by elevation of bone morphogenetic proteins. Conclusions Treatment with GHRH agonists appears to reduce the inflammatory responses post-MI and may consequently improve mechanisms of healing and cardiac remod eling by regulating pathways involved in fibrosis, apoptosis and cardiac repair. Patients with cardiac dysfunction could benefit from treatment with novel GHRH agonists. PMID:25797248

  4. Improvement of islet function in a bioartificial pancreas by enhanced oxygen supply and growth hormone releasing hormone agonist

    PubMed Central

    Ludwig, Barbara; Rotem, Avi; Schmid, Janine; Weir, Gordon C.; Colton, Clark K.; Brendel, Mathias D.; Neufeld, Tova; Block, Norman L.; Yavriyants, Karina; Steffen, Anja; Ludwig, Stefan; Chavakis, Triantafyllos; Reichel, Andreas; Azarov, Dimitri; Zimermann, Baruch; Maimon, Shiri; Balyura, Mariya; Rozenshtein, Tania; Shabtay, Noa; Vardi, Pnina; Bloch, Konstantin; de Vos, Paul; Schally, Andrew V.; Bornstein, Stefan R.; Barkai, Uriel

    2012-01-01

    Islet transplantation is a feasible therapeutic alternative for metabolically labile patients with type 1 diabetes. The primary therapeutic target is stable glycemic control and prevention of complications associated with diabetes by reconstitution of endogenous insulin secretion. However, critical shortage of donor organs, gradual loss in graft function over time, and chronic need for immunosuppression limit the indication for islet transplantation to a small group of patients. Here we present a promising approach to address these limitations by utilization of a macrochamber specially engineered for islet transplantation. The s.c. implantable device allows for controlled and adequate oxygen supply and provides immunological protection of donor islets against the host immune system. The minimally invasive implantable chamber normalized blood glucose in streptozotocin-induced diabetic rodents for up to 3 mo. Sufficient graft function depended on oxygen supply. Pretreatment with the growth hormone-releasing hormone (GHRH) agonist, JI-36, significantly enhanced graft function by improving glucose tolerance and increasing β-cell insulin reserve in rats thereby allowing for a reduction of the islet mass required for metabolic control. As a result of hypervascularization of the tissue surrounding the device, no relevant delay in insulin response to glucose changes has been observed. Consequently, this system opens up a fundamental strategy for therapy of diabetes and may provide a promising avenue for future approaches to xenotransplantation. PMID:22393012

  5. Immunocytochemical and pharmacological evidence for an intrinsic cholinomimetic system modulating prolactin and growth hormone release in rat pituitary.

    PubMed

    Carmeliet, P; Denef, C

    1988-08-01

    Pituitary cells were cultured as three-dimensional reaggregates in serum-free chemically defined medium supplemented with different concentrations of dexamethasone. Immunostaining of the cells using a polyclonal antiserum and three monoclonal antibodies raised against choline acetyl transferase (CAT), revealed the presence of CAT immunoreactivity in 4-10% of anterior pituitary cells depending on the antibody used. CAT immunoreactivity was also found in freshly dispersed anterior pituitary cells. CAT-immunoreactive cells could be enriched on BSA and Percoll gradients and codistributed with ACTH-immunoreactive cells in these gradients. Perifusion of the aggregates with the potent muscarinic receptor antagonist atropine (Atr) resulted in a dose-dependent (0.1-100 nM) increase in both basal PRL and GH secretion; the response was dependent on the dexamethasone concentration in the culture medium. A similar response to Atr was observed in organ-cultured pituitaries. The specificity of the Atr effect was supported by the findings that the potent and highly specific muscarinic receptor blocker dexetimide showed a similar action, whereas its inactive enantiomer levetimide and the nicotinic receptor blocker hexamethonium failed to do so. Two other muscarinic antagonists, benzatropine and pirenzepine, showed a dose-dependent hormone-releasing action similar to that of Atr, but were less potent than the latter. Pirenzepine was only effective at high molar concentrations, suggesting that an M2 muscarinic receptor subtype was mediating the present phenomenon. Atr also potentiated GH release stimulated by the beta-adrenergic agonist isoproterenol and PRL release stimulated by vasoactive intestinal peptide, but had no effect on GRF-stimulated GH release. The choline uptake blocker hemicholinium abolished the effect of Atr on GH and PRL release. These data suggest that certain pituitary cells can express CAT activity and that these cells exert a tonic inhibitory activity on GH and

  6. Effects of retinoic acid on growth hormone-releasing hormone receptor, growth hormone secretagogue receptor gene expression and growth hormone secretion in rat anterior pituitary cells.

    PubMed

    Maliza, Rita; Fujiwara, Ken; Tsukada, Takehiro; Azuma, Morio; Kikuchi, Motoshi; Yashiro, Takashi

    2016-06-30

    Retinoic acid (RA) is an important signaling molecule in embryonic development and adult tissue. The actions of RA are mediated by the nuclear receptors retinoic acid receptor (RAR) and retinoid X receptor (RXR), which regulate gene expression. RAR and RXR are widely expressed in the anterior pituitary gland. RA was reported to stimulate growth hormone (GH) gene expression in the anterior pituitary cells. However, current evidence is unclear on the role of RA in gene expression of growth hormone-releasing hormone receptor (Ghrh-r), growth hormone secretagogue receptor (Ghs-r) and somatostatin receptors (Sst-rs). Using isolated anterior pituitary cells of rats, we examined the effects of RA on gene expression of these receptors and GH release. Quantitative real-time PCR revealed that treatment with all-trans retinoic acid (ATRA; 10(-6) M) for 24 h increased gene expression levels of Ghrh-r and Ghs-r; however, expressions of Sst-r2 and Sst-r5 were unchanged. Combination treatment with the RAR-agonist Am80 and RXR-agonist PA024 mimicked the effects of ATRA on Ghrh-r and Ghs-r gene expressions. Exposure of isolated pituitary cells to ATRA had no effect on basal GH release. In contrast, ATRA increased growth hormone-releasing hormone (GHRH)- and ghrelin-stimulated GH release from cultured anterior pituitary cells. Our results suggest that expressions of Ghrh-r and Ghs-r are regulated by RA through the RAR-RXR receptor complex and that RA enhances the effects of GHRH and ghrelin on GH release from the anterior pituitary gland. PMID:27052215

  7. Nitrogen balance and mineral excretion in growing male pigs injected with a human growth hormone-releasing factor analog.

    PubMed Central

    Dubreuil, P; Abribat, T; Brazeau, P; Lapierre, H

    1998-01-01

    A human growth hormone-releasing factor analog ([Desamino-Tyr1,D-Ala2,Ala15] hGRF(1-29) NH2) has been reported to reduce feed intake and increase growth and feed efficiency in a dose-dependent manner in growing pigs. The aim of this study was to determine the effect of this analog on nitrogen (N) balance and mineral excretion. Fifteen castrated male Yorkshire x Landrace pigs (45.9 +/- 1.4 kg) were randomly allotted to 2 groups: control (saline, n = 7) and GRF (6.66 micrograms/kg sc, TID, n = 8). The animals were injected for 20 consecutive days: feces and urine were collected during the last 10 d of injection. The animals had free access to water and food until satiety (approximately 15 min) at 07:00, 11:00, 15:00, 19:00, 23:00 and 07:00 h. The diet consisted of a hog fattening ration (18.0% crude protein). Blood samples were collected on the last day of the study by venipuncture. This analog increased (P < 0.05) insulin-like growth factor-1 and glucose serum concentrations and decreased (P < 0.05) serum urea nitrogen concentration and feed intake. The GRF-treated animals ingested less N, excreted less N in urine and feces to retain a similar amount of N than controls. The apparent coefficient of digestibility of the N has been slightly increased (P < 0.05) by GRF. Urinary excretion of P, K, and Cl decreased (P < 0.01) with GRF treatment. In conclusion, this GRF analog increased N digestibility and retention relative to N ingestion and reduced urinary N, P, K, and Cl excretion. PMID:9442933

  8. Bed rest suppresses bioassayable growth hormone release in response to muscle activity

    NASA Technical Reports Server (NTRS)

    McCall, G. E.; Goulet, C.; Grindeland, R. E.; Hodgson, J. A.; Bigbee, A. J.; Edgerton, V. R.

    1997-01-01

    Hormonal responses to muscle activity were studied in eight men before (-13 or -12 and -8 or -7 days), during (2 or 3, 8 or 9, and 13 or 14 days) and after (+2 or +3 and +10 or +11 days) 17 days of bed rest. Muscle activity consisted of a series of unilateral isometric plantar flexions, including 4 maximal voluntary contractions (MVCs), 48 contractions at 30% MVC, and 12 contractions at 80% MVC, all performed at a 4:1-s work-to-rest ratio. Blood was collected before and immediately after muscle activity to measure plasma growth hormone by radioimmunoassay (IGH) and by bioassay (BGH) of tibia epiphyseal cartilage growth in hypophysectomized rats. Plasma IGH was unchanged by muscle activity before, during, or after bed rest. Before bed rest, muscle activity increased (P < 0.05) BGH by 66% at -13 or -12 days (2,146 +/- 192 to 3,565 +/- 197 microg/l) and by 92% at -8 or -7 days (2,162 +/- 159 to 4,161 +/- 204 microg/l). After 2 or 3 days of bed rest, there was no response of BGH to the muscle activity, a pattern that persisted through 8 or 9 days of bed rest. However, after 13 or 14 days of bed rest, plasma concentration of BGH was significantly lower after than before muscle activity (2,594 +/- 211 to 2,085 +/- 109 microg/l). After completion of bed rest, muscle activity increased BGH by 31% at 2 or 3 days (1,807 +/- 117 to 2,379 +/- 473 microg/l; P < 0.05), and by 10 or 11 days the BGH response was similar to that before bed rest (1,881 +/- 75 to 4,160 +/- 315 microg/l; P < 0.05). These data demonstrate that the ambulatory state of an individual can have a major impact on the release of BGH, but not IGH, in response to a single bout of muscle activity.

  9. Decreased hypothalamic growth hormone-releasing hormone content and pituitary responsiveness in hypothyroidism.

    PubMed Central

    Katakami, H; Downs, T R; Frohman, L A

    1986-01-01

    The effects of thyroidectomy (Tx) and thyroxine replacement (T4Rx) on pituitary growth hormone (GH) secretion and hypothalamic GH-releasing hormone (GRH) concentration were compared to define the mechanism of hypothyroid-associated GH deficiency. Thyroidectomized rats exhibited a complete loss of pulsatile GH secretion with extensive reduction in GRH responsiveness and pituitary GH content. Cultured pituitary cells from Tx rats exhibited reduced GRH sensitivity, maximal GH responsiveness, and intracellular cyclic AMP accumulation to GRH, while somatostatin (SRIF) suppressive effects on GH secretion were increased. Hypothalamic GRH content was also markedly reduced. T4Rx completely restored hypothalamic GRH content and spontaneous GH secretion despite only partial recovery of pituitary GH content, GRH and SRIF sensitivity, and intracellular cyclic AMP response to GRH. The results indicate multiple effects of hypothyroidism on GH secretion and suggest that a critical role of T4 in maintaining normal GH secretion, in addition to restoring GH synthesis, is related to its effect on hypothalamic GRH. Images PMID:2871046

  10. Thyroid Hormone and Estrogen Regulate Exercise-Induced Growth Hormone Release

    PubMed Central

    Ignacio, Daniele Leão; da S. Silvestre, Diego H.; Cavalcanti-de-Albuquerque, João Paulo Albuquerque; Louzada, Ruy Andrade

    2015-01-01

    Growth hormone (GH) regulates whole body metabolism, and physical exercise is the most potent stimulus to induce its secretion in humans. The mechanisms underlying GH secretion after exercise remain to be defined. The aim of this study was to elucidate the role of estrogen and pituitary type 1 deiodinase (D1) activation on exercise-induced GH secretion. Ten days after bilateral ovariectomy, animals were submitted to 20 min of treadmill exercise at 75% of maximum aerobic capacity and tissues were harvested immediately or 30 min after exercise. Non-exercised animals were used as controls. A significant increase in D1 activity occurred immediately after exercise (~60%) in sham-operated animals and GH was higher (~6-fold) 30 min after exercise. Estrogen deficient rats exhibited basal levels of GH and D1 activity comparable to those found in control rats. However, after exercise both D1 activity and serum GH levels were blunted compared to sedentary rats. To understand the potential cause-effect of D1 activation in exercise-induced GH release, we pharmacologically blocked D1 activity by propylthiouracil (PTU) injection into intact rats and submitted them to the acute exercise session. D1 inhibition blocked exercise-induced GH secretion, although basal levels were unaltered. In conclusion, estrogen deficiency impairs the induction of thyroid hormone activating enzyme D1 in the pituitary, and GH release by acute exercise. Also, acute D1 activation is essential for exercise-induced GH response. PMID:25874614

  11. Thyroid hormone and estrogen regulate exercise-induced growth hormone release.

    PubMed

    Ignacio, Daniele Leão; da S Silvestre, Diego H; Cavalcanti-de-Albuquerque, João Paulo Albuquerque; Louzada, Ruy Andrade; Carvalho, Denise P; Werneck-de-Castro, João Pedro

    2015-01-01

    Growth hormone (GH) regulates whole body metabolism, and physical exercise is the most potent stimulus to induce its secretion in humans. The mechanisms underlying GH secretion after exercise remain to be defined. The aim of this study was to elucidate the role of estrogen and pituitary type 1 deiodinase (D1) activation on exercise-induced GH secretion. Ten days after bilateral ovariectomy, animals were submitted to 20 min of treadmill exercise at 75% of maximum aerobic capacity and tissues were harvested immediately or 30 min after exercise. Non-exercised animals were used as controls. A significant increase in D1 activity occurred immediately after exercise (~60%) in sham-operated animals and GH was higher (~6-fold) 30 min after exercise. Estrogen deficient rats exhibited basal levels of GH and D1 activity comparable to those found in control rats. However, after exercise both D1 activity and serum GH levels were blunted compared to sedentary rats. To understand the potential cause-effect of D1 activation in exercise-induced GH release, we pharmacologically blocked D1 activity by propylthiouracil (PTU) injection into intact rats and submitted them to the acute exercise session. D1 inhibition blocked exercise-induced GH secretion, although basal levels were unaltered. In conclusion, estrogen deficiency impairs the induction of thyroid hormone activating enzyme D1 in the pituitary, and GH release by acute exercise. Also, acute D1 activation is essential for exercise-induced GH response. PMID:25874614

  12. Pulsatile growth hormone release in Turner's syndrome and short normal children.

    PubMed

    Ghizzoni, L; Lamborghini, A; Ziveri, M; Volta, C; Panza, C; Balestrazzi, P; Bernasconi, S

    1990-09-01

    To determine whether the quantitative and qualitative aspects of GH secretion in girls with Turner's syndrome are similar to those of short-normal children we studied the 24-h GH secretion of 10 patients with Turner's syndrome and 9 short-normal children with comparable auxological features. GH profiles, obtained by 30-min sampling, were analysed by the Pulsar programme. The pulsatile GH release over the 24 h in Turner's syndrome was similar to that in normal children. However, when the GH release over the 12 day and night hours were separately analysed, only normal children showed a night-time increase in the sum of peak amplitudes. Moreover, patients with Turner's syndrome had significantly decreased number and frequency of peaks in the night-time compared with short children. In short-normal children but not in Turner's syndrome, height velocity was related to the 24-h integrated concentration of GH, area under the curve over zero-line and over baseline, sum of peak areas, and amplitudes. Night-time GH area over zero-line and over baseline, mean peak amplitude, height area, sum of peak area and amplitudes were positively correlated with height velocity in short children, whereas in Turner's syndrome height velocity was related to daytime parameters only. In conclusion, girls with Turner's syndrome have a discrete pattern of pulsatile GH release. However, the relation of GH secretion to growth in these patients, is uncertain. PMID:2239077

  13. Pharmacodynamic evaluation of a PEGylated analogue of human growth hormone releasing factor in rats and pigs.

    PubMed

    D'Antonio, M; Louveau, I; Esposito, P; Bertolino, M; Canali, S

    2004-06-01

    The aim of this study was to assess the in vivo efficacy of monoPEGylated GRF(1-29)NH(2) having one PEG(5000) chains attached to either lysine 12 or 21 as compared to the GRF(1-29)NH(2) in rats and pigs. This analogue termed GRF-1PEG(5000) was tested after a single intravenous administration in rats and after a single intravenous or subcutaneous injection in pigs. After 1 h administration, GH concentrations returned to values close to controls in the group of rats injected with GRF(1-29)NH(2). In animals injected with the same dose of GRF-1PEG(5000), the AUC values corresponding to the whole period 0.5-48 h and particularly to the 0.5-8 h period were higher than in the placebo or in the GRF(1-29)NH(2) groups. Interestingly, two additional peaks were observed at about 6 and 8 h following administration. An increase in the response of the endogenous GH peaks was also observed in pigs administered GRF-1PEG(5000) by intravenous route. When GRF-1PEG(5000) was administered subcutaneously to pigs, a significant increase, as compared to placebo and GRF(1-29)NH(2,) in both GH and IGF-I levels was observed. This new analogue might find therapeutic application in paediatric growth hormone deficiency or in aging. PMID:15125884

  14. Potentiation of mammary cancer inhibition by combination of antagonists of growth hormone-releasing hormone with docetaxel

    PubMed Central

    Buchholz, Stefan; Schally, Andrew V.; Engel, Jörg B.; Hohla, Florian; Heinrich, Elmar; Koester, Frank; Varga, Jozsef L.; Halmos, Gabor

    2007-01-01

    Antagonists of growth hormone-releasing hormone (GHRH) are being developed for the treatment of various cancers. In this study, we investigated the effectiveness of treatment with GHRH antagonist JMR-132 alone and in combination with docetaxel chemotherapy in nude mice bearing MX-1 human breast cancers. Specific high-affinity binding sites for GHRH were found on MX-1 tumor membranes using ligand competition assays with 125I-labeled GHRH antagonist JV-1-42. JMR-132 displaced radiolabeled JV-1-42 with an IC50 of 0.14 nM, indicating a high affinity of JMR-132 to GHRH receptors. Treatment of nude mice bearing xenografts of MX-1 with JMR-132 at 10 μg per day s.c. for 22 days significantly (P < 0.05) inhibited tumor volume by 62.9% and tumor weight by 47.8%. Docetaxel given twice at a dose of 20 mg/kg i.p. significantly reduced tumor volume and weight by 74.1% and 58.6%, respectively. Combination treatment with JMR-132 (10 μg/day) and docetaxel (20 mg/kg i.p.) led to growth arrest of most tumors as shown by an inhibition of tumor volume and weight by 97.7% and 95.6%, respectively (P < 0.001). Because no vital cancer cells were detected in some of the excised tumors, a total regression of the tumors was achieved in some cases. Treatment with JMR-132 also strongly reduced the concentration of EGF receptors in MX-1 tumors. Our results demonstrate that GHRH antagonists might provide a therapy for breast cancer and could be combined with docetaxel chemotherapy to enhance the efficacy of treatment. PMID:17261802

  15. The goldfish nervus terminalis: a luteinizing hormone-releasing hormone and molluscan cardioexcitatory peptide immunoreactive olfactoretinal pathway.

    PubMed Central

    Stell, W K; Walker, S E; Chohan, K S; Ball, A K

    1984-01-01

    Antisera to two putative neurotransmitters, luteinizing hormone-releasing hormone (LHRH) and molluscan cardioexcitatory tetrapeptide (H-Phe-Met-Arg-Phe-NH2; FMRF-amide), bind specifically to neurites in the inner nuclear and inner plexiform layers of the goldfish retina. Retrograde labeling showed that intraocular axon terminals originate from the nervus terminalis, whose cell bodies are located in the olfactory nerves. Double immunocytochemical and retrograde labeling showed that some terminalis neurons project to the retina; others may project only within the brain. All terminalis neurons having proven retinal projections were both LHRH- and FMRF-amide-immunoreactive. The activity of retinal ganglion cells was recorded with microelectrodes in isolated superfused goldfish retinas. In ON- and OFF-center double-color-opponent cells, micromolar FMRF-amide and salmon brain gonadotropin-releasing factor ( [Trp7, Leu8] LHRH) caused increased spontaneous activity in the dark, loss of light-induced inhibition, and increased incidence of light-entrained pulsatile response. The nervus terminalis is therefore a putatively peptidergic retinopetal projection. Sex-related olfactory stimuli may act through it, thereby modulating the output of ganglion cells responsive to color contrast. Images PMID:6199789

  16. Experiment K-7-22: Growth Hormone Regulation Synthesis and Secretion in Microgravity. Part 2; Hypothalamic Growth Hormone-Releasing Factor, Somatostatin Immunoreactivity, and Messenger RNA Levels in Microgravity

    NASA Technical Reports Server (NTRS)

    Sawchenko, P. E.; Arias, C.; Krasnov, I.; Grindeland, R. E.; Vale, W.

    1994-01-01

    Immunohistochemical analyses of hypothalamic hormones carried out on tissue from rats flown on an earlier flight (Cosmos 1887) suggested preferential effects on hypophysiotropic principles involved in the regulation of growth hormone secretion and synthesis. We found that staining in the median eminence for peptides that provide both stimulatory (growth hormone-releasing factor, or GRF) and inhibitory (somatostatin, SS) influences on growth hormone secretion were depressed in flight animals relative to synchronous controls, while staining for other neuroendocrine peptides, cortocotropin-releasing factor and arginine vasopressin, were similar in these two groups. While this suggests some selective impact of weightlessness on the two principal central nervous system regulators of growth hormone dynamics, the fact that both GRF- and SS-immunoreactivity (IR) appeared affected in the same direction is somewhat problematic, and makes tentative any intimation that effects on CNS control mechanisms may be etiologically significant contributors to the sequelae of reduced growth hormone secretion seen in prolonged space flight. To provide an additional, and more penetrating, analysis we attempted in hypothalamic material harvested from animals flown on Cosmos 2044 to complement immunohistochemical analyses of GRF and SS staining with quantitative, in situ assessments of messenger RNAs encoding the precursors for both these hormones.

  17. Protective effect of Growth Hormone-Releasing Hormone agonist in bacterial toxin-induced pulmonary barrier dysfunction

    PubMed Central

    Czikora, Istvan; Sridhar, Supriya; Gorshkov, Boris; Alieva, Irina B.; Kasa, Anita; Gonzales, Joyce; Potapenko, Olena; Umapathy, Nagavedi S.; Pillich, Helena; Rick, Ferenc G.; Block, Norman L.; Verin, Alexander D.; Chakraborty, Trinad; Matthay, Michael A.; Schally, Andrew V.; Lucas, Rudolf

    2014-01-01

    Rationale: Antibiotic treatment of patients infected with G− or G+ bacteria promotes release of the toxins lipopolysaccharide (LPS) and pneumolysin (PLY) in their lungs. Growth Hormone-releasing Hormone (GHRH) agonist JI-34 protects human lung microvascular endothelial cells (HL-MVEC), expressing splice variant 1 (SV-1) of the receptor, from PLY-induced barrier dysfunction. We investigated whether JI-34 also blunts LPS-induced hyperpermeability. Since GHRH receptor (GHRH-R) signaling can potentially stimulate both cAMP-dependent barrier-protective pathways as well as barrier-disruptive protein kinase C pathways, we studied their interaction in GHRH agonist-treated HL-MVEC, in the presence of PLY, by means of siRNA-mediated protein kinase A (PKA) depletion. Methods: Barrier function measurements were done in HL-MVEC monolayers using Electrical Cell substrate Impedance Sensing (ECIS) and VE-cadherin expression by Western blotting. Capillary leak was assessed by Evans Blue dye (EBD) incorporation. Cytokine generation in broncho-alveolar lavage fluid (BALF) was measured by multiplex analysis. PKA and PKC-α activity were assessed by Western blotting. Results: GHRH agonist JI-34 significantly blunts LPS-induced barrier dysfunction, at least in part by preserving VE-cadherin expression, while not affecting inflammation. In addition to activating PKA, GHRH agonist also increases PKC-α activity in PLY-treated HL-MVEC. Treatment with PLY significantly decreases resistance in control siRNA-treated HL-MVEC, but does so even more in PKA-depleted monolayers. Pretreatment with GHRH agonist blunts PLY-induced permeability in control siRNA-treated HL-MVEC, but fails to improve barrier function in PKA-depleted PLY-treated monolayers. Conclusions: GHRH signaling in HL-MVEC protects from both LPS and PLY-mediated endothelial barrier dysfunction and concurrently induces a barrier-protective PKA-mediated and a barrier-disruptive PKC-α-induced pathway in the presence of PLY, the

  18. Peptide hormone release monitored from single vesicles in "membrane lawns" of differentiated male pituitary cells: SNAREs and fusion pore widening.

    PubMed

    Stenovec, Matjaž; Gonçalves, Paula P; Zorec, Robert

    2013-03-01

    In this study we used live-cell immunocytochemistry and confocal microscopy to study the release from a single vesicle in a simplified system called membrane lawns. The lawns were prepared by exposing differentiated pituitary prolactin (PRL)-secreting cells to a hypoosmotic shear stress. The density of the immunolabeled ternary soluble N-ethylmaleimide-sensitive factor-attachment protein receptor (SNARE) complexes that bind complexin was approximately 10 times lower than the PRL-positive, lawn-resident vesicles; this indicates that some but not all vesicles are associated with ternary SNARE complexes. However, lawn-resident PRL vesicles colocalized relatively well with particular SNARE proteins: synaptobrevin 2 (35%), syntaxin 1 (22%), and 25-kDa synaptosome associated protein (6%). To study vesicle discharge, we prepared lawn-resident vesicles, derived from atrial natriuretic peptide tagged with emerald fluorescent protein (ANP.emd)-transfected cells, which label vesicles. These maintained the structural passage to the exterior because approximately 40% of ANP.emd-loaded vesicles were labeled by extracellular PRL antibodies. Cargo release from the lawn-resident vesicles, monitored by the decline in the ANP.emd fluorescence intensity, was similar to that in intact cells. It is likely that SNARE proteins are required for calcium-dependent release from these vesicles. This is because the expression of the dominant-negative SNARE peptide, which interferes with SNARE complex formation, reduced the number of PRL-positive spots per cell (PRL antibodies placed extracellularly) significantly, from 58 ± 9 to 4 ± 2. In dominant-negative SNARE-treated cells, the PRL-positive area was reduced from 0.259 ± 0.013 to 0.123 ± 0.014 μm(2), which is consistent with a hindered vesicle luminal access for extracellular PRL antibodies. These results indicate that vesicle discharge is regulated by SNARE-mediated fusion pore widening. PMID:23372020

  19. Growth Hormone Response after Administration of L-dopa, Clonidine, and Growth Hormone Releasing Hormone in Children with Down Syndrome.

    ERIC Educational Resources Information Center

    Pueschel, Seigfried M.

    1993-01-01

    This study of eight growth-retarded children with Down's syndrome (aged 1 to 6.5 years) found that administration of growth hormone was more effective than either L-dopa or clonidine. Results suggest that children with Down's syndrome have both anatomical and biochemical hypothalamic derangements resulting in decreased growth hormone secretion and…

  20. Antagonists of growth hormone-releasing hormone (GH-RH) enhance tumour growth inhibition induced by androgen deprivation in human MDA-Pca-2b prostate cancers.

    PubMed

    Letsch, M; Schally, A V; Stangelberger, A; Groot, K; Varga, J L

    2004-02-01

    In the present study, we investigated whether the growth hormone-releasing hormone (GH-RH) antagonist JV-1-38 could enhance the effects of androgen deprivation produced by the anti-androgen Flutamide and luteinising hormone-releasing hormone (LH-RH) agonist Decapeptyl in an experimental model of human androgen-sensitive MDA PCa 2b prostate carcinoma implanted subcutaneously (s.c.) into nude mice. We also evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR) the effects of combined treatment on the mRNA expression for prostate-specific antigen (PSA) and measured serum PSA levels. In experiment 1, GH-RH antagonist JV-1-38 greatly inhibited tumour growth in combination with Decapeptyl, but was ineffective when given alone. Thus, combined therapy with JV-1-38 at 20 microg/day and Decapeptyl microcapsules releasing 12.5 microg/day for 29 days inhibited significantly (P<0.01) MDA PCa 2b tumour growth by 65%, compared with controls. Combined treatment also significantly (P<0.05) decreased serum PSA levels by 52% and reduced tumour weight by 54% vs. controls. In experiment 2, GH-RH antagonist JV-1-38 at 20 microg/day likewise showed powerful growth inhibitory effects when combined with Flutamide (25 mg/kg/day) for 21 days. Combined treatment with JV-1-38 and slow-release pellets of Flutamide significantly (P<0.001) inhibited tumour growth by 61% versus controls, and was significantly (P<0.05) more effective than Flutamide or JV-1-38 alone. Combination therapy also reduced significantly (P<0.001) tumour weight and serum PSA levels by 59 and 47%, respectively. The mRNA expression for PSA in MDA PCa 2b tumours was not changed by JV-1-38, Decapeptyl and Flutamide alone or in their respective combinations. Our findings suggest that GH-RH antagonists could enhance the tumour inhibitory effects of androgen deprivation for the primary therapy of patients with advanced prostate carcinoma. PMID:14746863

  1. Evaluation of growth hormone release and human growth hormone treatment in children with cranial irradiation-associated short stature

    SciTech Connect

    Romshe, C.A.; Zipf, W.B.; Miser, A.; Miser, J.; Sotos, J.F.; Newton, W.A.

    1984-02-01

    We studied nine children who had received cranial irradiation for various malignancies and subsequently experienced decreased growth velocity. Their response to standard growth hormone stimulation and release tests were compared with that in seven children with classic GH deficiency and in 24 short normal control subjects. With arginine and L-dopa stimulation, six of nine patients who received radiation had a normal GH response (greater than 7 ng/ml), whereas by design none of the GH deficient and all of the normal children had a positive response. Only two of nine patients had a normal response to insulin hypoglycemia, with no significant differences in the mean maximal response of the radiation and the GH-deficient groups. Pulsatile secretion was not significantly different in the radiation and GH-deficient groups, but was different in the radiation and normal groups. All subjects in the GH-deficient and radiation groups were given human growth hormone for 1 year. Growth velocity increased in all, with no significant difference in the response of the two groups when comparing the z scores for growth velocity of each subject's bone age. We recommend a 6-month trial of hGH in children who have had cranial radiation and are in prolonged remission with a decreased growth velocity, as there is no completely reliable combination of GH stimulation or release tests to determine their response.

  2. Inhibition of growth of a prolactin and growth hormone-secreting pituitary tumor in rats by D-tryptophan-6 analog of luteinizing hormone-releasing hormone.

    PubMed Central

    Torres-Aleman, I; Redding, T W; Schally, A V

    1985-01-01

    The effect of long-term administration of analogs of luteinizing hormone-releasing hormone (LH-RH) and somatostatin on the growth of the growth hormone (GH)- and prolactin (PRL)-secreting rat pituitary GH3 tumor was investigated. Daily administration of [D-Trp6]LH-RH (50 micrograms/day), early after inoculation of the GH3 tumor, inhibited tumor growth by more than 90% as compared to controls. Similarly, in two experiments, a single once-a-month injection of long-acting [D-Trp6]LH-RH microcapsules (in a dose calculated to release about 25 micrograms/day for 30 days) inhibited the growth of GH3 pituitary tumor by more than 50% 6 or 13 wk after transplantation, when the tumors were fully developed. Serum GH and PRL levels also were reduced markedly by treatment with [D-Trp6]LH-RH. On the other hand, the administration of an antagonistic analog of LH-RH, N-Ac-[D-Phe(4Cl)1,2, D-Trp3, D-Arg6, D-Ala10]LH-RH, did not significantly reduce the growth of this tumor, and the treatment with two different analogs of somatostatin, cyclo(Pro-Phe-D-Trp-Lys-Thr-Phe) and D-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-Thr NH2, appeared to enhance it. These results are in agreement with previous findings of growth inhibition of 7315a pituitary tumors with different hormone-secreting characteristics by agonistic analogs of LH-RH. The collective data from experimental work with rat pituitary tumor models support the contention that the use of [D-Trp6]LH-RH might be considered for the treatment of some patients with pituitary tumors who failed to respond to conventional therapy. PMID:2858096

  3. Growth hormone responses to growth hormone-releasing hormone in Hand-Schüller-Christian Disease.

    PubMed

    Gelato, M C; Loriaux, D L; Merriam, G R

    1989-09-01

    Bolus doses of GH-releasing hormone (GHRH), 1 microgram/kg i.v., were given to two groups of adult patients with growth hormone deficiency (GHD): 9 with Hand-Schüller-Christian disease (HSCD, presumed hypothalamic GHD) and 9 with idiopathic GHD (IGHD, etiology unknown). Six patients in each group were then given further GHRH doses daily for 5 days, and the GH responses to GHRH were measured over 3 h on day 1 and day 5. Plasma levels of insulin-like growth factor-I (IGF-I) were measured twice daily on days 1 and 5 during GHRH treatment. All patients with HSCD had measurable GH responses to the first dose of GHRH, with a mean peak response of 6.4 +/- 2.1 ng/ml (mean +/- SE). Only 5 of 9 patients with IGHD had GH responses above the detection limits of the assay; their mean peak response, 1.3 +/- 0.2 ng/ml, was significantly lower than the GH responses of the HSCD patients (p less than 0.05). Responses in both groups of patients were lower than those previously observed in normal adult men (35 +/- 8 ng/ml; p less than 0.01). Five days of daily stimulation with GHRH significantly (p less than 0.01) increased the GH response in both groups of patients. The rise was greater in patients with HSCD than with IGHD (HSCD, 5.1 +/- 2.5 ng/ml on day 1, vs. 12.0 +/- 6.8 ng/ml on day 5; IGHD, 1.4 +/- 0.3 ng/ml vs. 2.9 +/- 0.6 ng/ml).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2507952

  4. Androgen-dependent somatotroph function in a hypogonadal adolescent male: evidence for control of exogenous androgens on growth hormone release

    SciTech Connect

    Mauras, N.; Blizzard, R.M.; Rogol, A.D.

    1989-03-01

    A 14(10/12)-year-old white male with primary gonadal failure following testicular irradiation for acute lymphocytic leukemia was evaluated for poor growth. He had received 2400 rad of prophylactic cranial irradiation. The growth velocity had decelerated from 7 to 3.2 cm/yr over 3 years. His bone age was 12(0/12) years (by TW2-RUS), and his peak growth hormone (GH) response to provocative stimuli was 1.4 ng/mL. The 24-hour GH secretion was studied by drawing blood every 20 minutes for 24 hours. The resulting GH profile was analyzed by a computerized pulse detection algorithm, CLUSTER. Timed serum GH samples were also obtained after a 1 microgram/kg IV bolus injection of the GH releasing factor (GRH). The studies showed a flat 24-hour profile and a peak GH response to GRH of 3.9 ng/ml. Testosterone enanthate treatment was started, 100 mg IM every 4 weeks. Ten months after the initiation of therapy the calculated growth rate was 8.6 cm/yr. The 24-hour GH study and GRH responses were repeated at the time, showing a remarkably normal 24-hour GH secretory pattern and a peak GH response to GRH of 14.4 ng/mL. Testosterone therapy was discontinued, and 4 months later similar studies were repeated. A marked decrease in the mean 24-hour GH secretion and mean peak height occurred, but with maintenance of the GH pulse frequency. The GH response to GRH was intermediate, with a peak of 8 ng/mL. There was no further growth during those 4 months despite open epiphyses.

  5. Polymorphisms of the porcine cathepsins, growth hormone-releasing hormone and leptin receptor genes and their association with meat quality traits in Ukrainian Large White breed.

    PubMed

    Balatsky, Viktor; Bankovska, Irina; Pena, Ramona N; Saienko, Artem; Buslyk, Tetyana; Korinnyi, Sergii; Doran, Olena

    2016-06-01

    Cathepsins, growth hormone-releasing hormone (GHRH) and leptin receptor (LEPR) genes have been receiving increasing attention as potential markers for meat quality and pig performance traits. This study investigated the allele variants in four cathepsin genes (CTSB, CTSK, CTSL, CTSS), GHRH and LEPR in pure-bred Ukrainian Large White pigs and evaluated effects of the allele variants on meat quality characteristics. The study was conducted on 72 pigs. Genotyping was performed using PCR-RFLP technique. Meat quality characteristics analysed were intramuscular fat content, tenderness, total water content, ultimate pH, crude protein and ashes. A medium level of heterozygosity values was established for GHRH and LEPR genes which corresponded to very high levels of informativeness indexes. Cathepsins CTSL, CTSB and CTSK had a low level of heterozygosity, and CTSS did not segregate in this breed. Association studies established that intramuscular fat content and tenderness were affected by the allele variance in GHRH and LEPR but not by CTSB and CTSL genes. The GHRH results could be particularly relevant for the production of lean prime cuts as the A allele is associated with both, a lower meat fat content and better tenderness values, which are two attributes highly regarded by consumers. Results of this study suggest that selective breeding towards GHRH/AA genotype would be particularly useful for improving meat quality characteristics in the production systems involving lean Large White lines, which typically have less than 2 % intramuscular fat content. PMID:27075656

  6. Beneficial effects of growth hormone-releasing hormone agonists on rat INS-1 cells and on streptozotocin-induced NOD/SCID mice

    PubMed Central

    Zhang, Xianyang; Cui, Tengjiao; He, Jinlin; Wang, Haibo; Cai, Renzhi; Popovics, Petra; Vidaurre, Irving; Sha, Wei; Schmid, Janine; Ludwig, Barbara; Block, Norman L.; Bornstein, Stefan R.; Schally, Andrew V.

    2015-01-01

    Agonists of growth hormone-releasing hormone (GHRH) have been previously reported to promote growth, function, and engraftment of islet cells following transplantation. Here we evaluated recently synthesized GHRH agonists on the proliferation and biological functions of rat pancreatic β-cell line (INS-1) and islets. In vitro treatment of INS-1 cells with GHRH agonists increased cell proliferation, the expression of cellular insulin, insulin-like growth factor-1 (IGF1), and GHRH receptor, and also stimulated insulin secretion in response to glucose challenge. Exposure of INS-1 cells to GHRH agonists, MR-356 and MR-409, induced activation of ERK and AKT pathways. Agonist MR-409 also significantly increased the levels of cellular cAMP and the phosphorylation of cAMP response element binding protein (CREB) in INS-1 cells. Treatment of rat islets with agonist, MR-409 significantly increased cell proliferation, islet size, and the expression of insulin. In vivo daily s.c. administration of 10 μg MR-409 for 3 wk dramatically reduced the severity of streptozotocin (STZ)-induced diabetes in nonobese diabetic severe combined immunodeficiency (NOD/SCID) mice. The maximal therapeutic benefits with respect to the efficiency of engraftment, ability to reach normoglycemia, gain in body weight, response to high glucose challenge, and induction of higher levels of serum insulin and IGF1 were observed when diabetic mice were transplanted with rat islets preconditioned with GHRH agonist, MR-409, and received additional treatment with MR-409 posttransplantation. This study provides an improved approach to the therapeutic use of GHRH agonists in the treatment of diabetes mellitus. PMID:26474831

  7. ATP-modulated K+ channels sensitive to antidiabetic sulfonylureas are present in adenohypophysis and are involved in growth hormone release.

    PubMed Central

    Bernardi, H; De Weille, J R; Epelbaum, J; Mourre, C; Amoroso, S; Slama, A; Fosset, M; Lazdunski, M

    1993-01-01

    The adenohypophysis contains high-affinity binding sites for antidiabetic sulfonylureas that are specific blockers of ATP-sensitive K+ channels. The binding protein has a M(r) of 145,000 +/- 5000. The presence of ATP-sensitive K+ channels (26 pS) has been demonstrated by electrophysiological techniques. Intracellular perfusion of adenohypophysis cells with an ATP-free medium to activate ATP-sensitive K+ channels induces a large hyperpolarization (approximately 30 mV) that is antagonized by antidiabetic sulfonylureas. Diazoxide opens ATP-sensitive K+ channels in adenohypophysis cells as it does in pancreatic beta cells and also induces a hyperpolarization (approximately 30 mV) that is also suppressed by antidiabetic sulfonylureas. As in pancreatic beta cells, glucose and antidiabetic sulfonylureas depolarize the adenohypophysis cells and thereby indirectly increase Ca2+ influx through L-type Ca2+ channels. The K+ channel opener diazoxide has an opposite effect. Opening ATP-sensitive K+ channels inhibits growth hormone secretion and this inhibition is eliminated by antidiabetic sulfonylureas. Images PMID:8433992

  8. Relationship between nitric oxide- and calcium-dependent signal transduction pathways in growth hormone release from dispersed goldfish pituitary cells.

    PubMed

    Chang, John P; Sawisky, Grant R; Davis, Philip J; Pemberton, Joshua G; Rieger, Aja M; Barreda, Daniel R

    2014-09-15

    Nitric oxide (NO) and Ca(2+) are two of the many intracellular signal transduction pathways mediating the control of growth hormone (GH) secretion from somatotropes by neuroendocrine factors. We have previously shown that the NO donor sodium nitroprusside (SNP) elicits Ca(2+) signals in identified goldfish somatotropes. In this study, we examined the relationships between NO- and Ca(2+)-dependent signal transduction mechanisms in GH secretion from primary cultures of dispersed goldfish pituitary cells. Morphologically identified goldfish somatotropes stained positively for an NO-sensitive dye indicating they may be a source of NO production. In 2h static incubation experiments, GH release responses to the NO donor S-nitroso-N-acetyl-d,l-penicillamine (SNAP) were attenuated by CoCl2, nifedipine, verapamil, TMB-8, BHQ, and KN62. In column perifusion experiments, the ability of SNP to induce GH release was impaired in the presence of TMB-8, BHQ, caffeine, and thapsigargin, but not ryanodine. Caffeine-elicited GH secretion was not affected by the NO scavenger PTIO. These results suggest that NO-stimulated GH release is dependent on extracellular Ca(2+) availability and voltage-sensitive Ca(2+) channels, as well as intracellular Ca(2+) store(s) that possess BHQ- and/or thapsigargin-inhibited sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPases, as well as TMB-8- and/or caffeine-sensitive, but not ryanodine-sensitive, Ca(2+)-release channels. Calmodulin kinase-II also likely participates in NO-elicited GH secretion but caffeine-induced GH release is not upstream of NO production. These findings provide insights into how NO actions many integrate with Ca(2+)-dependent signalling mechanisms in goldfish somatotropes and how such interactions may participate in the GH-releasing actions of regulators that utilize both NO- and Ca(2+)-dependent transduction pathways. PMID:25038498

  9. Qualitative identification of growth hormone-releasing hormones in human plasma by means of immunoaffinity purification and LC-HRMS/MS.

    PubMed

    Knoop, Andre; Thomas, Andreas; Fichant, Eric; Delahaut, Philippe; Schänzer, Wilhelm; Thevis, Mario

    2016-05-01

    The use of growth hormone-releasing hormones (GHRHs) is prohibited in sports according to the regulations of the World Anti-Doping Agency (WADA). The aim of the present study was to develop a method for the simultaneous detection of four different GHRHs and respective metabolites from human plasma by means of immunoaffinity purification and subsequent nano-ultrahigh performance liquid chromatography-high resolution/high accuracy (tandem) mass spectrometry. The target analytes included Geref (Sermorelin), CJC-1293, CJC-1295, and Egrifta (Tesamorelin) as well as two metabolites of Geref and CJC-1293, which were captured from plasma samples using a polyclonal GHRH antibody in concert with protein A/G monolithic MSIA™ D.A.R.T.'S® (Disposable Automation Research Tips) prior to separation and detection. The method was fully validated and found to be fit for purpose considering the parameters specificity, linearity, recovery (19-37%), lower limit of detection (<50 pg/mL), imprecision (<20%), and ion suppression/enhancement effects. The analytes' stability and metabolism were elucidated using in vitro and in vivo approaches. EDTA blood samples were collected from rats 2, 4, and 8 h after intravenous administration of GHRH (one compound per test animal). All intact substances were detected for at least 4 h but no anticipated metabolite was confirmed in laboratory rodents' samples; conversely, a Geref metabolite (GHRH3-29) was found in a human plasma sample collected after subcutaneous injection of the drug to a healthy male volunteer. The obtained results demonstrate that GHRHs are successfully detected in plasma using an immunoaffinity-mass spectrometry-based method, which can be applied to sports drug testing samples. Further studies are however required and warranted to account for potential species-related differences in metabolism and elimination of the target analytes. PMID:26879649

  10. Effects of growth hormone-releasing hormone on sleep and brain interstitial fluid amyloid-β in an APP transgenic mouse model

    PubMed Central

    Liao, Fan; Zhang, Tony J.; Mahan, Thomas E.; Jiang, Hong; Holtzman, David M.

    2014-01-01

    Alzheimer’s Disease (AD) is a neurodegenerative disorder characterized by impairment of cognitive function, extracellular amyloid plaques, intracellular neurofibrillary tangles, and synaptic and neuronal loss. There is substantial evidence that the aggregation of amyloid β (Aβ) in the brain plays a key role in the pathogenesis of AD and that Aβ aggregation is a concentration dependent process. Recently, it was found that Aβ levels in the brain interstitial fluid (ISF) are regulated by the sleep-wake cycle in both humans and mice; ISF Aβ is higher during wakefulness and lower during sleep. Intracerebroventricular infusion of orexin increased wakefulness and ISF Aβ levels, and chronic sleep deprivation significantly increased Aβ plaque formation in amyloid precursor protein transgenic (APP) mice. Growth hormone-releasing hormone (GHRH) is a well-documented sleep regulatory substance which promotes non-rapid eye movement sleep. GHRHRlit/lit mice that lack functional GHRH receptor have shorter sleep duration and longer wakefulness during light periods. The current study was undertaken to determine whether manipulating sleep by interfering with GHRH signaling affects brain ISF Aβ levels in APPswe/PS1ΔE9 (PS1APP) transgenic mice that overexpress mutant forms of APP and PSEN1 that cause autosomal dominant AD. We found that intraperitoneal injection of GHRH at dark onset increased sleep and decreased ISF Aβ and that delivery of a GHRH antagonist via reverse-microdialysis suppressed sleep and increased ISF Aβ. The diurnal fluctuation of ISF Aβ in PS1APP/GHRHRlit/lit mice was significantly smaller than that in PS1APP/GHRHRlit/+ mice. However despite decreased sleep in GHRHR deficient mice, this was not associated with an increase in Aβ accumulation later in life. One of several possibilities for the finding is the fact that GHRHR deficient mice have GHRH-dependent but sleep-independent factors which protect against Aβ deposition. PMID:25218899

  11. Noradrenergic regulation of hypothalamic cells that produce growth hormone-releasing hormone and somatostatin and the effect of altered adiposity in sheep.

    PubMed

    Iqbal, J; Manley, T R; Yue, Q; Namavar, M R; Clarke, I J

    2005-06-01

    The growth hormone (GH) axis is sensitive to alteration in body weight and there is evidence that central noradrenergic systems regulate neurones that produce growth hormone-releasing hormone (GHRH) and somatostatin (SRIF). This study reports semiquantitative estimates of the noradrenergic input to neuroendocrine GHRH and SRIF neurones in the sheep of different body weights. We also studied the effects of altered body weight on expression of dopamine beta-hydroxylase (DBH), the enzyme that produces noradrenalin from dopamine. Ovariectomised ewes were made Lean (39.6 +/- 2.6 kg; Mean +/- SEM) by dietary restriction, whereas Normally Fed animals (61.2 +/- 0.8 kg) were maintained on a regular diet. Brains were perfused for immunohistochemistry and in situ hybridisation. The Mean +/- SEM number of GHRH-immunoreactive (-IR) cells was lower in Normally Fed (65 +/- 7) than in Lean (115 +/- 14) animals, whereas the number of SRIF-IR cells was similar in the two groups (Normally Fed, 196 +/- 17; Lean 230 +/- 21). Confocal microscopic analysis revealed that the percentage of GHRH-IR cells (Normally Fed 36 +/- 1.5% versus Lean 32 +/- 4.6%) and percentage of SRIF-IR cells (Normally Fed 30 +/- 40.4% versus Lean 32 +/- 2.3%) contacted by noradrenergic fibres did not change with body weight. FluoroGold retrograde tracer injections confirmed that noradrenergic projections to the arcuate nucleus are from ventrolateral medulla and noradrenergic projections to periventricular nucleus arise from the ventrolateral medulla, nucleus of solitary tract, locus coeruleus (LC) and the parabrachial nucleus (PBN). DBH expressing cells were identified using immunohistochemistry and in situ hybridisation and the level of expression (silver grains/cell) quantified by image analysis. The number of DBH cells was similar in Normally Fed and Lean animals, but the level of expression/cell was lower (P < 0.02) in the PBN and LC of Lean animals. These results provide an anatomical basis for the

  12. Predictors of Treatment Response to Tesamorelin, a Growth Hormone-Releasing Factor Analog, in HIV-Infected Patients with Excess Abdominal Fat

    PubMed Central

    Mangili, Alexandra; Falutz, Julian; Mamputu, Jean-Claude; Stepanians, Miganush; Hayward, Brooke

    2015-01-01

    Background Tesamorelin, a synthetic analog of human growth hormone-releasing factor, decreases visceral adipose tissue (VAT) in human immunodeficiency virus (HIV)-infected patients with lipodystrophy. Objectives 1) To evaluate the utility of patient characteristics and validated disease-risk scores, namely indicator variables for the metabolic syndrome defined by the International Diabetes Federation (MetS-IDF) or the National Cholesterol Education Program (MetS-NCEP) and the Framingham Risk Score (FRS), as predictors of VAT reduction during tesamorelin therapy at 3 and 6 months, and 2) To explore the characteristics of patients who reached a threshold of VAT <140 cm2, a level associated with lower risk of adverse health outcomes, after 6 months of treatment with tesamorelin. Methods Data were analyzed from two Phase 3 studies in which HIV-infected patients with excess abdominal fat were randomized in a 2:1 ratio to receive tesamorelin 2 mg (n = 543) or placebo (n = 263) subcutaneously daily for 6 months, using ANOVA and ANCOVA models. Results Metabolic syndrome (MetS-IDF or MetS-NCEP) and FRS were significantly associated with VAT at baseline. Presence of metabolic syndrome ([MetS-NCEP), triglyceride levels >1.7 mmol/L, and white race had a significant impact on likelihood of response to tesamorelin after 6 months of therapy (interaction p-values 0.054, 0.063, and 0.025, respectively). No predictive factors were identified at 3 months. The odds of a VAT reduction to <140 cm2 for subjects treated with tesamorelin was 3.9 times greater than that of subjects randomized to placebo after controlling for study, gender, baseline body mass index (BMI) and baseline VAT (95% confidence interval [CI] 2.03; 7.44). Conclusions Individuals with baseline MetS-NCEP, elevated triglyceride levels, or white race were most likely to experience reductions in VAT after 6 months of tesamorelin treatment. The odds of response of VAT <140 cm2 was 3.9 times greater for tesamorelin

  13. Growth Hormone-Releaser Diet Attenuates Cognitive Dysfunction in Klotho Mutant Mice via Insulin-Like Growth Factor-1 Receptor Activation in a Genetic Aging Model

    PubMed Central

    Park, Seok Joo; Chung, Yoon Hee; Lee, Jeong Hyun; Dang, Duy-Khanh; Nam, Yunsung; Jeong, Ji Hoon; Kim, Yong Sun; Nabeshima, Toshitaka

    2014-01-01

    Background It has been recognized that a defect in klotho gene expression accelerates the degeneration of multiple age-sensitive traits. Accumulating evidence indicates that aging is associated with declines in cognitive function and the activity of growth hormone (GH)/insulin-like growth factor-1 (IGF-1). Methods In this study, we examined whether a GH-releaser diet could be effective in protecting against cognitive impairment in klotho mutant mice. Results The GH-releaser diet significantly induced the expression of IGF-1 and IGF-1 receptors in the hippocampus of klotho mutant mice. Klotho mutant mice showed significant memory impairments as compared with wild-type mice. In addition, the klotho mutation significantly decreased the expression of cell survival/antiapoptotic factors, including phospho-Akt (p-Akt)/phospho-glycogen synthase kinase3β (p-GSK3β), phospho-extracellular signal-related kinase (p-ERK), and Bcl-2, but significantly increased those of cell death/proapoptotic factors, such as phospho-c-jun N-terminal kinase (p-JNK), Bax, and cleaved caspase-3 in the hippocampus. Treatment with GH-releaser diet significantly attenuated both decreases in the expression of cell survival/antiapoptotic factors and increases in the expression of cell death/proapoptotic factors in the hippocampus of klotho mutant mice. In addition, klotho mutation-induced oxidative stress was significantly attenuated by the GH-releaser diet. Consequently, a GH-releaser diet significantly improved memory function in the klotho mutant mice. GH-releaser diet-mediated actions were significantly reversed by JB-1, an IGF-1 receptor antagonist. Conclusion The results suggest that a GH-releaser diet attenuates oxidative stress, proapoptotic changes and consequent dysfunction in klotho mutant mice by promoting IGF-1 expression and IGF-1 receptor activation. PMID:25309793

  14. Interaction of growth hormone-releasing hormone with the insulin-like growth-factors during prenatal development in the rat.

    PubMed

    Spatola, E; Pescovitz, O H; Marsh, K; Johnson, N B; Berry, S A; Gelato, M C

    1991-09-01

    The placenta is a chimeric organ that produces all the components of the hypothalamic-pituitary GH axis. We propose that placental GH-releasing hormone (GHRH) stimulates placental GH-like hormones which in turn stimulate production of the insulin-like growth factors (IGFs), IGF-I and IGF-II, and these placental IGFs are important for growth and development of the placenta as well as the fetus. To test this hypothesis, pregnant rats were given either GHRH antisera or preimmune sera ip from days 7-19 of gestation. Fetuses were killed on day 19, and IGF-I and IGF-II tissue and serum concentrations in the mother and fetus were measured by RIA. IGF-II receptor content was measured by Western analysis. IGF-I and IGF-II messenger (m) RNA levels were measured in the placentas as well as in the fetal livers. The GHRH antibody titer was highest at day 19 of gestation but continued to be present through day 20 of postnatal development. Although placental weights did not differ, antibody-treated animals had higher placental IGF-I and IGF-II levels (I, 108 +/- 6 (SD); II, 126 +/- 5 ng/g, respectively) vs. control animals (I, 88 +/- 2.5 (SD); II, 48 +/- 11 ng/g) in pooled specimens. The IGF-II receptor was also up-regulated in placentas from antibody-treated mothers. The fetuses of antibody-treated (A) mothers were larger than the controls (C) (A, 2.615 g; C, 2.49 g, P less than 0.05). Levels of both IGFs were significantly increased in livers of antibody treated fetuses (IGF-I: A, 15 +/- 1 (SD); C, 12 +/- 0.8 ng/g; and IGF-II: A, 295 +/- 10 (SD); C, 233 +/- 10 (SD) ng/g). In addition, the concentration of the IGF-II receptor in liver of antibody-treated fetuses was also increased. Further, pooled fetal sera from antibody-treated fetuses had higher levels of IGF-II than controls (A, 950 ng/ml; C, 700 ng/ml), and the circulating IGF-II receptor was increased as measured by Western analysis. In the liver, IGF-II mRNA levels of antibody-treated fetuses were increased to 117% of

  15. Lymphocyte subset distribution and natural killer activity in growth hormone deficiency before and during short-term treatment with growth hormone releasing hormone.

    PubMed

    Kiess, W; Malozowski, S; Gelato, M; Butenand, O; Doerr, H; Crisp, B; Eisl, E; Maluish, A; Belohradsky, B H

    1988-07-01

    Natural killer (NK) cell activity was assessed in the peripheral blood of 20 patients with growth hormone (GH) deficiency due to a hypothalamic deficit of GH-releasing hormone (GHRH). All patients failed to respond to at least two provocative tests of GH secretion (GH below 7 ng/ml) but responded to a single GHRH iv bolus injection (1 microgram/kg body wt). In 14 of the 20 patients (20 determinations), lymphocyte subsets were also measured; in all patients the distribution of lymphocyte subsets was within the normal range. More importantly, NK cell activity in the 20 patients was significantly lower than in controls (P less than 0.01). To assess the in vivo effect of GH and GHRH on NK activity and lymphocyte subset distribution, immunologic tests were performed (i) before and after a single iv bolus injection of GHRH (1 microgram/kg body wt) in six patients; (ii) before and after 3 weeks of GHRH treatment (3-9 micrograms/kg body wt, one to four times daily) in five patients; and (iii) after 6 weeks of GH treatment (5 IU sc every alternate day) in one patient. Neither NK activity nor the distribution of lymphocyte subsets was altered during short-term GHRH administration. In conclusion, low NK activity is found in GH-deficient patients, and short-term administration of GH or GHRH fails to restore this immunological abnormality. This result suggests that the hypothalamus may be a regulator of NK activity in the human and that patients with hypothalamic deficiencies should be monitored for the development of discrete immunodeficiencies. PMID:3133146

  16. Effect of different growth hormone-releasing factors on the concentrations of growth hormone, insulin and metabolites in the plasma of sheep maintained in positive and negative energy balance.

    PubMed

    Hart, I C; Chadwick, P M; Coert, A; James, S; Simmonds, A D

    1985-04-01

    Three experiments were conducted to compare the ability of different preparations of growth hormone-releasing factor (GRF) to stimulate GH secretion in sheep maintained in positive and negative energy balance. In experiment 1 five sheep were injected (i.v.) with three preparations of human pancreatic GRF (hpGRF-44, hpGRF-40, hpGRF-29-NH2) and one preparation of rat hypothalamic GRF (rhGRF-29-NH2) all at 98.0 pmol/kg, or control vehicle, in a Latin square design when the animals either had free access to food or were fed half their maintenance requirements. Analysis of plasma samples, obtained before and for 150 min after injection, revealed that the reduced food intake resulted in the expected changes in body weight and circulating GH, insulin, glucose, urea and non-esterified fatty acids. The maximum post-injection concentrations of GH did not differ between either the two levels of feeding or the four GRF preparations but the mean post-injection concentration of GH was significantly higher for all GRF treatments on the restricted ration (P less than 0.001). The mean post-injection response to rhGRF-29-NH2 was less than that obtained with hpGRF-44 for sheep with food available ad libitum (P less than 0.05) and was clearly more persistent for all GRF treatments in animals fed the reduced diet (P less than 0.001). In experiment 2 the same five sheep were injected i.v. with rhGRF-29-NH2 (98.0 pmol/kg) when they had free access to food and after food had been withdrawn for 3 days.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2859343

  17. Overexpression of the growth-hormone-releasing hormone gene in acromegaly-associated pituitary tumors. An event associated with neoplastic progression and aggressive behavior.

    PubMed Central

    Thapar, K.; Kovacs, K.; Stefaneanu, L.; Scheithauer, B.; Killinger, D. W.; Lioyd, R. V.; Smyth, H. S.; Barr, A.; Thorner, M. O.; Gaylinn, B.; Laws, E. R.

    1997-01-01

    The clinical behavior of growth hormone (GH)-producing pituitary tumors is known to vary greatly; however, the events underlying this variability remain poorly understood. Herein we demonstrate that tumor overexpression of the GH-releasing hormone (GHRH) gene is one prognostically informative event associated with the clinical aggressiveness of somatotroph pituitary tumors. Accumulation of GHRH mRNA transcripts was demonstrated in 91 of a consecutive series of 100 somatotroph tumors by in situ hybridization; these findings were corroborated by Northern analysis and reverse transcriptase polymerase chain reaction, and protein translation was confirmed by Western blotting. By comparison, transcript accumulation was absent or negligibly low in 30 normal pituitary glands. GHRH transcripts were found to preferentially accumulate among clinically aggressive tumors. Specifically, GHRH mRNA signal intensity was 1) linearly correlated with Ki-67 tumor growth fractions (r = 0.71; P < 0.001), 2) linearly correlated with preoperative serum GH levels (r = 0.56; p = 0.01), 3) higher among invasive tumors (P < 0.001), and 4) highest in those tumors in which post-operative remission was not achieved (P < 0.001). Using multivariate logistic regression, a model of postoperative remission likelihood was derived wherein remission was defined by the single criterion of suppressibility of GH levels to less than 2 ng/ml during an oral glucose tolerance test. In this outcome model, GHRH mRNA signal intensity proved to be the most important explanatory variable overall, eclipsing any and all conventional clinicopathological predictors as the single most significant predictor of postoperative remission; increases in GHRH mRNA signal were associated with marked declines in remission likelihood. The generalizability of this outcome model was further validated by the model's significant performance in predicting postoperative remission in a random sample of 30 somatotroph tumors treated at

  18. Differential effects of estrogen and medroxyprogesterone on basal and stress-induced growth hormone release, IGF-1 levels, and cellular immunity in postmenopausal women.

    PubMed

    Malarkey, W B; Burleson, M; Cacioppo, J T; Poehlmann, K; Glaser, R; Kiecolt-Glaser, J K

    1997-10-01

    We evaluated the influence of continual estrogen replacement therapy (ERT) as presently practiced by postmenopausal women with conjugated estrogens and medroxyprogesterone acetate (MPA) on the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis and cellular immunity. Thirty-nine postmenopausal women were evaluated (12 on no replacement, 14 on estrogen only, and 13 on estrogen and MPA). In the women receiving only conjugated estrogens, increased GH levels and decreased IGF-1 levels were found, which replicated previous research and probably reflected estrogen inhibition of hepatic IGF-1 production with a secondary increase in GH release because of reduced feedback inhibition. In women taking both MPA and estrogen, GH was increased and the previously observed estrogen induced decrease in IGF-1 levels was inhibited. In order to determine the influence of ERT on psycho-social stress-induced GH release, math (mental stress) and speech (social stress) challenges were utilized, and they produced significant increases in heart rate in all three groups. The heart rate following stress was significantly enhanced by estrogen replacement. These stressors also led to increased GH secretion in the women taking estrogen and MPA, but not in the other two groups. Gonadal steroids and GH can influence cellular immunity. We observed that ERT in both groups was associated with significantly enhanced lymphocyte responsiveness to the T-cell mitogens phytohemaglutinin (PHA) and Conconavalin A (Con A), and basal GH levels were correlated with the PHA response in the estrogen only group. ERT did not influence natural killer (NK) cell activity. We also found significant differences in the steady-state expression of latent Epstein-Barr virus (EBV) with increased antibody titers in the women in the estrogen only group and lower antibody titers in the MPA plus estrogen group. GH levels were correlated with EBV antibody titers in the estrogen plus MPA group. This study supports the

  19. Involvement of protein kinase C and intracellular Ca2+ in goldfish brain somatostatin-28 inhibitory action on growth hormone release in goldfish.

    PubMed

    Yu, Y; Chang, J P

    2010-08-01

    Goldfish brain somatostatin-28 (gbSS-28) is present in brain and pituitary tissues of goldfish. We assessed whether gbSS-28 targets Ca(2+) and/or protein kinase C (PKC)-dependent signaling cascades in inhibiting growth hormone (GH) release. gbSS-28 decreased basal GH release from primary cultures of dispersed goldfish pituitary cells and intracellular free calcium levels ([Ca(2+)](i)) in goldfish somatotropes. gbSS-28 partially reduced [Ca(2+)](i) and GH responses induced by two endogeneous gonadotropin-releasing hormones (GnRHs), salmon (s)GnRH and chicken (c)GnRH-II. Furthermore, gbSS-28 reduced GH increases and abolished [Ca(2+)](i) elevations elicited by two PKC activators, tetradecanoyl 4beta-phorbol-13-acetate and dioctanyl glycerol. The PKC inhibitors Gö6976 and Bis II abolished [Ca(2+)](i) responses to PKC activators, but only attenuated GnRH-induced increases in [Ca(2+)](i) and did not alter basal [Ca(2+)](i). In cells pretreated with Bis II, gbSS-28 further reduced basal [Ca(2+)](i). Our results suggest that gbSS-28 inhibits GnRH-induced GH release in part by attenuating PKC-mediated GnRH [Ca(2+)](i) signals. gbSS-28 reduces basal GH release also via reduction in [Ca(2+)](i) but PKC is not involved in this regard. PMID:20403359

  20. Effect of Oral Glucose Administration on Rebound Growth Hormone Release in Normal and Obese Women: The Role of Adiposity, Insulin Sensitivity and Ghrelin

    PubMed Central

    Pena-Bello, Lara; Pertega-Diaz, Sonia; Outeiriño-Blanco, Elena; Garcia-Buela, Jesus; Tovar, Sulay; Sangiao-Alvarellos, Susana; Dieguez, Carlos; Cordido, Fernando

    2015-01-01

    Context Metabolic substrates and nutritional status play a major role in growth hormone (GH) secretion. Uncovering the mechanisms involved in GH secretion following oral glucose (OG) administration in normal and obese patients is a pending issue. Objective The aim of this study was to investigate GH after OG in relation with adiposity, insulin secretion and action, and ghrelin secretion in obese and healthy women, to further elucidate the mechanism of GH secretion after OG and the altered GH secretion in obesity. Participants and Methods We included 64 healthy and obese women. After an overnight fast, 75 g of OG were administered; GH, glucose, insulin and ghrelin were obtained during 300 minutes. Insulin secretion and action indices and the area under the curve (AUC) were calculated for GH, glucose, insulin and ghrelin. Univariate and multivariate linear regression analyses were employed. Results The AUC of GH (μg/L•min) was lower in obese (249.8±41.8) than in healthy women (490.4±74.6), P=0.001. The AUC of total ghrelin (pg/mL•min) was lower in obese (240995.5±11094.2) than in healthy women (340797.5±37757.5), P=0.042. There were significant correlations between GH secretion and the different adiposity, insulin secretion and action, and ghrelin secretion indices. After multivariate analysis only ghrelin AUC remained a significant predictor for fasting and peak GH. PMID:25782001

  1. Treatment of true precocious puberty with a potent luteinizing hormone-releasing factor agonist: effect on growth, sexual maturation, pelvic sonography, and the hypothalamic-pituitary-gonadal axis.

    PubMed

    Styne, D M; Harris, D A; Egli, C A; Conte, F A; Kaplan, S L; Rivier, J; Vale, W; Grumbach, M M

    1985-07-01

    We used the LHRH agonist D-Trp6-Pro6-N-ethylamide LHRH (LHRH-A) to treat 19 children (12 girls and 7 boys) with true precocious puberty. Fourteen patients had idiopathic true precocious puberty, 4 had a hamartoma of the tuber cinereum, and 1 had a hypothalamic astrocytoma. Basal gonadotropin secretion and responses to native LHRH decreased within 1 week of initiation LHRH-A therapy, and sex steroid secretion decreased within 2 weeks to or within the prepubertal range. Ultrasonographic evaluation of the uterus indicated a postmenarchal size and shape in all 11 girls studied before treatment, which reverted to prepubertal size and configuration in 5 girls during LHRH-A therapy. The enlarged ovaries decreased in size and the multiple ovarian follicular cysts regressed. Sexual characteristics ceased advancing or reverted toward the prepubertal state in all patients receiving therapy for 6-36 months. All 5 girls with menarche before therapy had no further menses. Three girls had hot flashes after LHRH-A-induced reduction of the plasma estradiol concentration. Height velocity, SDs above the mean height velocity for age, and SDs above the mean height for age decreased during LHRH-A therapy; the velocity of skeletal maturation decreased after 12 months of LHRH-A therapy and was sustained during continued therapy over 18-36 months. In 4 patients, a subnormal growth rate (less than 4.5 cm/yr) occurred during LHRH-A therapy. Six patients had cutaneous reactions of LHRH-A, but no demonstrable circulating antibodies to LHRH-A. In 2 patients in whom LHRH-A therapy was discontinued because of skin reactions, precocious sexual maturation resumed at the previous rate for the ensuing 6-12 months; subsequently, they were desensitized to LHRH-A, and during a second course of therapy, their secondary sexual development and sex steroid levels again quickly decreased. LHRH-A proved an effective and safe treatment for true precocious puberty in boys as well as girls with central

  2. Analogues of luteinizing hormone-releasing hormone containing cytotoxic groups.

    PubMed Central

    Janáky, T; Juhász, A; Bajusz, S; Csernus, V; Srkalovic, G; Bokser, L; Milovanovic, S; Redding, T W; Rékási, Z; Nagy, A

    1992-01-01

    In an attempt to produce better cytotoxic analogues, chemotherapeutic antineoplastic radicals including an alkylating nitrogen mustard derivative of D-phenylalanine (D-melphalan), reactive cyclopropane, anthraquinone derivatives [2-(hydroxymethyl)anthraquinone and the anticancer antibiotic doxorubicin], and an antimetabolite (methotrexate) were coupled to suitably modified agonists and antagonists of luteinizing hormone-releasing hormone (LH-RH). Analogues with D-lysine6 and D-ornithine6 or N epsilon-(2,3-diaminopropionyl)-D-lysine and N delta-(2,3-diaminopropionyl)-D-ornithine were used as carriers for one or two cytotoxic moieties. The enhanced biological activities produced by the incorporation of D amino acids into position 6 of the agonistic analogues were further increased by the attachment of hydrophobic cytotoxic groups, resulting in compounds with 10-50 times higher activity than LH-RH. Most of the monosubstituted agonistic analogues showed high affinities for the membrane receptors of human breast cancer cells, while the receptor binding affinities of peptides containing two cytotoxic side chains were lower. Antagonistic carriers [Ac-D-Nal(2)1,D-Phe(4Cl)2,D-Trp3,Arg5,D-Lys6,D-Ala10] LH-RH [where Nal(2) is 3-(2-naphthyl)alanine], [Ac-D-Nal(2)1,D-Phe(4Cl)2,D-Trp3,Arg5,N epsilon-(2,3-diaminopropionyl)-D-Lys6,D-Ala10]LH-RH, and their D-Pal(3)3 homologs [Pal(3) is 3-(3-pyridyl)alanine] as well as [Ac-D-Nal(2)1,D-Phe(4Cl)2,D-Pal(3)3,Tyr5,N epsilon-(2,3-diamino-propionyl)-D-Lys6,D-Ala10]LH-RH were linked to cytotoxic compounds. The hybrid molecules inhibited ovulation in rats at doses of 10 micrograms and suppressed LH release in vitro. The receptor binding of cytotoxic analogues was decreased compared to the precursor peptides, although analogues with 2-(hydroxymethyl)anthraquinone hemiglutarate had high affinities. All of the cytotoxic analogues tested inhibited [3H]thymidine incorporation into DNA in cultures of human breast and prostate cancer cell lines

  3. Occurrence of D-aspartic acid and N-methyl-D-aspartic acid in rat neuroendocrine tissues and their role in the modulation of luteinizing hormone and growth hormone release.

    PubMed

    D'Aniello, A; Di Fiore, M M; Fisher, G H; Milone, A; Seleni, A; D'Aniello, S; Perna, A F; Ingrosso, D

    2000-04-01

    Using two specific and sensitive fluorometric/HPLC methods and a GC-MS method, alone and in combination with D-aspartate oxidase, we have demonstrated for the first time that N-methyl-D-aspartate (NMDA), in addition to D-aspartate (D-Asp), is endogenously present as a natural molecule in rat nervous system and endocrine glands. Both of these amino acids are mostly concentrated at nmol/g levels in the adenohypophysis, hypothalamus, brain, and testis. The adenohypophysis maximally showed the ability to accumulate D-Asp when the latter is exogenously administered. In vivo experiments, consisting of the i.p. injection of D-Asp, showed that D-Asp induced both growth hormone and luteinizing hormone (LH) release. However, in vitro experiments showed that D-Asp was able to induce LH release from adenohypophysis only when this gland was co-incubated with the hypothalamus. This is because D-Asp also induces the release of GnRH from the hypothalamus, which in turn is directly responsible for the D-Asp-induced LH secretion from the pituitary gland. Compared to D-Asp, NMDA elicits its hormone release action at concentrations approximately 100-fold lower than D-Asp. D-AP5, a specific NMDA receptor antagonist, inhibited D-Asp and NMDA hormonal activity, demonstrating that these actions are mediated by NMDA receptors. NMDA is biosynthesized from D-Asp by an S-adenosylmethionine-dependent enzyme, which we tentatively denominated as NMDA synthase. PMID:10744627

  4. Hormonal regulation of rat hypothalamic neuropeptide mRNAs: effect of hypophysectomy and hormone replacement on growth-hormone-releasing factor, somatostatin and the insulin-like growth factors.

    PubMed

    Wood, T L; Berelowitz, M; Gelato, M C; Roberts, C T; LeRoith, D; Millard, W J; McKelvy, J F

    1991-03-01

    Hormonal feedback regulation of hypothalamic peptides putatively involved in growth hormone (GH) regulation has been studied by measurement of steady-state mRNA levels in male hypophysectomized rats with or without thyroid hormone, corticosterone, testosterone or GH replacement. Hypothalamic GH-releasing factor (GRF) mRNA levels increased progressively following hypophysectomy to 420% of sham levels after 15 days while hypothalamic insulin-like growth factor I (IGF-I) and insulin-like growth factor II (IGF-II) mRNA levels decreased to less than 40% of sham levels. Whole hypothalamic somatostatin mRNA levels were not significantly different from sham. One week of continuous GH infusion restored hypothalamic IGF-I mRNA to levels (95%) indistinguishable from those in sham-operated controls but had no effect on either IGF-II or GRF mRNA. Thyroid hormone, corticosterone and testosterone treatment without GH had no effect on the hypophysectomy-induced reduction of either IGF-I or IGF-II mRNA levels but reversed the elevation of GRF mRNA. We conclude that hypothalamic IGF-I may be involved in GH feedback regulation and thus may function as a hypothalamic modulator of GH. In contrast, IGF-II may be regulated by one of the pituitary trophic hormones but not by GH or the target hormones tested. Finally, hypothalamic GRF mRNA regulation appears to be complex and may include target hormone feedback. PMID:1674982

  5. Naloxone does not Affect the Luteinizing Hormone-Releasing Hormone-Induced Inhibition of Luteinizing Hormone Secretion in Sheep.

    PubMed

    Naylor, A M; Porter, D W; Lincoln, D W

    1989-06-01

    Abstract Injection of luteinizing hormone-releasing hormone (21 pmol) into the third cerebral ventricle of long-term ovariectomized ewes caused a marked inhibition of luteinizing hormone secretion. Mean luteinizing hormone levels and luteinizing hormone pulse frequency were reduced significantly when compared with the control responses to saline (50 mul). A notable characteristic of the response was the delayed and sustained nature of the luteinizing hormone-releasing hormone-induced inhibition. In the presence of the opioid antagonist naloxone (4 +/- 25 mg iv), the central administration of luteinizing hormone-releasing hormone still produced a marked inhibition of luteinizing hormone secretion. Again, mean luteinizing hormone levels and luteinizing hormone pulse frequency were reduced significantly. When naloxone was injected iv, there was a significant rise in mean luteinizing hormone levels as a consequence of an increase in pulse frequency (in four out of five ewes) and a significant increase in luteinizing hormone pulse amplitude. In conclusion, these data suggest that central opioid pathways sensitive to blockade by naloxone are not involved in the luteinizing hormone-releasing hormone-induced inhibition of luteinizing hormone release. Furthermore, in the long-term ovariectomized ewe, endogenous opioid peptides exert a tonic inhibitory influence on luteinizing hormone-releasing hormone/luteinizing hormone secretion. PMID:19210459

  6. Clinical studies with d-Trp 6-luteinizing hormone-releasing hormone in anovulatory women.

    PubMed

    Jaramillo, C J; Charro-Salgado, A; Peréz-Infante, V; del Campo, G L; Botella-Llusiá, J; Coy, D H; Schally, A V

    1978-04-01

    Nine anovulatory patients with hypothalamic-pituitary dysfunction were treated with d-Trp6-luteinizing hormone-releasing hormone, an analog with far greater gonadotropin-releasing activity than luteinizing hormone-releasing hormone. Four of eight patients, who were formerly unsuccessfully treated with clomiphene, human chorionic gonadotropin, and human menopausal gonadotropin, ovulated after treatment with the peptide alone or with peptide preceded by clomiphene, and three became pregnant. The ninth patient, who had amenorrhea and anovulation due to excessive loss of weight caused by anorexia nervosa, also ovulated after treatment with the analog. These results demonstrate the effectiveness of this potent analog for induction of ovulation and pregnancy and point favorably toward clinical applications. PMID:348500

  7. Effects of spaceflight on hypothalamic peptide systems controlling pituitary growth hormone dynamics

    NASA Technical Reports Server (NTRS)

    Sawchenko, P. E.; Arias, C.; Krasnov, I.; Grindeland, R. E.; Vale, W.

    1992-01-01

    Possible effects of reduced gravity on central hypophysiotropic systems controlling growth hormone (GH) secretion were investigated in rats flown on Cosmos 1887 and 2044 biosatellites. Immunohistochemical (IHC)staining for the growth hormone-releasing factor (GRF), somatostatin (SS), and other hypothalamic hormones was performed on hypothalami obtained from rats. IHC analysis was complemented by quantitative in situ assessments of mRNAs encoding the precursors for these hormones. Data obtained suggest that exposure to microgravity causes a preferential reduction in GRF peptide and mRNA levels in hypophysiotropic neurons, which may contribute to impared GH secretion in animals subjected to spaceflight. Effects of weightlessness are not mimicked by hindlimb suspension in this system.

  8. Difference in growth hormone response to growth hormone-releasing hormone (GHRH) testing following GHRH subacute treatment in normal aging and growth hormone-deficient adults: possible perspectives for therapeutic use of GHRH or its analogs in elderly subjects?

    PubMed

    Iovino, M; Triggiani, V; Giagulli, V A; Iovine, N; Licchelli, B; Resta, F; Sabbà, C; Tafaro, E; Solimando, A; Tommasicchio, A; Guastamacchia, E

    2011-06-01

    The somatotroph axis function shows a decline in the elderly (somatopause). In particular growth hormone (GH) response to GH-releasing hormone (GHRH) is reduced in aged man but less than that observed in GH-deficient adults (GHDAs). Plasma GH response to GHRH (1 µg/kg BW) was significantly lower in four GHDAs than in seven healthy aged men 30, 60, and 90 min after acute GHRH administration. To verify whether a priming regimen might be able to increase the reduced GH response to GHRH, both healthy aged men and GHDA patients underwent repetitive administration of GHRH (100 µg GHRH intravenously as a single morning dose, every 2 days for 12 days). After the GHRH-priming regimen, plasma GH values 30, 60, and 90 min after the acute GHRH test were significantly higher than values at the corresponding time points before priming regimen in healthy aged men but not in GHDA patients. These findings confirmed that somatotroph cells become less sensitive to GHRH with normal aging and demonstrate that repetitive administration of GHRH restores the attenuated response only in healthy aged men but not in GHDA patients. This could support the possible use of GHRH or its analogs instead of recombinant human GH in elderly patients with the advantage of preserving the endogenous pulses of GH with the secretion of the different isoforms of GH. However, concerns arise about the possible role of these molecules in tumorigenesis and tumor growth promotion. PMID:20843274

  9. Growth hormone release of interleukin-1 alpha, interferon-gamma and interleukin-4 from murine splenocytes stimulated with staphylococcal protein A, toxic shock syndrome toxin-1 and streptococcal lysin S.

    PubMed

    Galdiero, M; Vitiello, M; Scarfogliero, P; Sommese, L

    1997-03-01

    We investigated changes in the IL-1 alpha, IFN-gamma and IL-4 release from splenocytes in the presence of growth hormone (GH). Splenocytes were stimulated with Protein A (PA), Toxic Shock Syndrome Toxin-1 (TSST-1) and Streptolysin S (SLS). In the presence of GH, splenocytes stimulated with PA, induced a 40% and 50% drop in IL-1 alpha and IFN-gamma release respectively, compared to controls, while no changes were shown in IL-4 release. The release of IFN-gamma by TSST-1-stimulated splenocytes fell by 30%, while no changes were shown in IL-1 alpha and IL-4 release after GH. The release of IL-1 alpha by SLS-stimulated splenocytes increased by 50% in the presence of GH. No changes were shown in IFN-gamma and IL-4 release. The results are discussed in terms of the possibility of an expanding function for these endocrine peptides within the immune system. PMID:9110153

  10. Mapping the human growth hormone-releasing hormone receptor (GHRHR) gene to the short arm of chromosome 7(7p13-p21) near the epidermal growth factor receptor (EGFR) gene

    SciTech Connect

    Vamvakopoulos, N.C. ); Kunz, J.; Olberding, U. ); Scherer, S.W. ); Sioutopoulou, O.T. ); Schneider, V.; Durkin, A.S.; Nierman, W.C. )

    1994-03-15

    In this report, the authors have assigned the human GHRHR gene to chromosome 7p13-p21, using polymerase chain reaction (PCR) amplification of DNA from well-defined human-rodent somatic cell hybrids. The GHRHR gene was assigned to human chromosome 7 by discordancy analysis (data not shown) of PCR amplification products from NIGMS mapping panel Nos. 1 and 2 DNA templates. The PCR primers (p[sub f], 5[prime]-GCTGCCTCATCACGCCACTGGAGTCCAC-3[prime]; and P[sub r], 5[prime]-CAGGTTTATTGGCTCCTCTGAGCCTTGG-3[prime]) amplified a 276-bp-long fragment from the 3[prime] untranslated region of the human GHRHR gene. Subsequently, they determined the location of the GHRHR gene within human chromosome 7 by PCR amplification of genomic DNA template from somatic cell hybrids that contain deletions of this chromosome. Amplification of the 276-bp DNA fragment was seen only in the cell lines that contained an intact chromosome 7 short arm. The lack of amplification using genomic DNA from 0044 Rag 1-15 and It A9 2-21-14 maps this gene to 7p13-p21. Additionally, the appropriate amplified product was observed from the human chromosome 4 containing NIGMS panel 2 cell line GM10115. This line was reported to have retained a small region of human chromosome 7 containing the epidermal growth factor receptor (EGFR) gene that is mapped to 7p12-p13. The authors conclude that the human GHRHR gene maps to the small arm of chromosome 7 within 7p13-p21 and close to the EGFR gene. This assignment is consistent with the syntenic relationship between mouse chromosome 6 and human chromosome 7 in this region.

  11. Peptide growth factors, part B

    SciTech Connect

    Barnes, D.; Sirbasku, D.A.

    1987-01-01

    This book discusses the following topics: Platelet-Derived Growth Factor;Nerve and Glial Growth Factors;PC12 Pheochromocytoma Cells;Techniques for the Study of Growth Factor Activity;Genetic Approaches and Biological Effects.

  12. Immunoreactive luteinizing hormone-releasing hormone in the seminal plasma and human semen parameters

    SciTech Connect

    Izumi, S.; Makino, T.; Iizuka, R.

    1985-04-01

    A luteinizing hormone-releasing hormone (LH-RH)-like substance has been detected in human seminal plasma by a radioimmunoassay (RIA) with a highly specific anti-LH-RH antiserum. The seminal samples - not only the plasma itself but also the sample extracted by an acid/alcohol method - showed satisfactory displacement curves in our RIA system. The relationship between fertility and the LH-RH values in the seminal plasma was studied by comparing the peptide levels with sperm concentration and motility. By these two parameters, 103 samples were divided into four groups. In the low-concentration groups (oligozoospermic patients), the hormonal concentrations differed significantly between those specimens demonstrating good and poor motility. These data suggest that this immunoreactive LH-RH may play a role in human spermatogenesis.

  13. Luteinizing hormone-releasing hormone and thyrotropin-releasing hormone in human and bovine milk.

    PubMed

    Amarant, T; Fridkin, M; Koch, Y

    1982-10-01

    Two hypothalamic peptide hormones, luteinizing hormone-releasing hormone (LHRH) and thyrotropin-releasing hormone (TRH), have been isolated from human milk and bovine colostrum. Acidified methanolic extracts, prepared from human milk, bovine colostrum and rat hypothalami, as well as synthetic LHRH and TRH markers were subjected to high-pressure liquid chromatography (HPLC). The eluates were tested for the presence of LHRH and TRH by specific radioimmunoassays. It was found that milk extracts contain significant amounts of LHRH (3.9 - 11.8 ng/ml) and TRH (0.16 - 0.34 ng/ml), which comigrate with the corresponding marker hormones and with those of hypothalamic origin. The HPLC-purified LHRH from both human and bovine milk was bioactive in a dose-response manner similar to synthetic LHRH. PMID:6816590

  14. Highly potent antagonists of luteinizing hormone-releasing hormone free of edematogenic effects.

    PubMed Central

    Bajusz, S; Kovacs, M; Gazdag, M; Bokser, L; Karashima, T; Csernus, V J; Janaky, T; Guoth, J; Schally, A V

    1988-01-01

    To eliminate the undesirable edematogenic effect of the luteinizing hormone-releasing hormone (LH-RH) antagonists containing basic D amino acids at position 6, exemplified by [Ac-D-Phe(pCl)1,2,D-Trp3,D-Arg6,D-Ala10]LH-RH [Phe(pCl) indicates 4-chlorophenylalanine], analogs with D-ureidoalkyl amino acids such as D-citrulline (D-Cit) or D-homocitrulline (D-Hci) at position 6 were synthesized and tested in several systems in vitro and in vivo. HPLC analysis revealed that the overall hydrophobicity of the D-Cit/D-Hci6 analogs was similar to that of the basic D-Arg6 antagonists. In vitro, most of the analogs completely inhibited LH-RH-mediated luteinizing hormone release in perfused rat pituitary cell systems at an antagonist to LH-RH molar ratio of 5:1. In vivo, the most active peptides, [Ac-D-Nal(2)1,D-Phe(pCl)2,D-Trp3,D-Cit6,D-Ala10]LH-RH [Nal(2) indicates 3-(2-naphthyl)alanine] and its D-Hci6 analog, caused 100% inhibition of ovulation in cycling rats in doses of 3 micrograms and suppressed the luteinizing hormone level in ovariectomized female rats for 47 hr when administered at doses of 25 micrograms. Characteristically, these peptides did not exert any edematogenic effects even at 1.5 mg/kg. These properties of the D-Cit/D-Hci6 antagonists may make them useful clinically. PMID:3278323

  15. Effects of chronic and subtoxic chlorobenzenes on adrenocorticotrophic hormone release.

    PubMed

    Molnár, Zsolt; Pálföldi, Regina; László, Anna; Radács, Marianna; Sepp, Krisztián; Hausinger, Péter; Tiszlavicz, László; Valkusz, Zsuzsanna; Gálfi, Márta

    2015-08-01

    Many environmental chemicals and pesticides have been found to alter neuroendocrine communication in exposed biological objects. The environmental loads have primary and secondary effects that can alter the homeostatic regulation potential. Since it is difficult to avoid human exposition, a potentially important area of research to develop in vivo and in vitro experimental models. In this context, the primary aim of this study was to demonstrate the effects of chlorobenzenes on adrenocorticotrophic hormone (ACTH) release. In our experimental study, male Wistar rats were exposed to 0.1, 1.0 and 10 μg/b.w. (body weight)kg of 1,2,4- trichlorobenzene and hexachlorobenzene (ClB) mix via gastric tube for 30, 60 or 90 days. At the endpoints of the experiment blood samples were taken and animals were decapitated. Primary, monolayer adenohypophysis cell cultures were prepared by enzymatic and mechanical digestion. The ACTH hormone content in serum and supernatant media was measured by immuno-chemiluminescence assay. The Mg(2+)-dependent ATPase activity was determined by modified method of Martin and Dotty. Significant differences were detected in the hormone release between the control and treated groups. The hormone release was enhanced characteristically in exposed groups depending upon the dose and duration of exposure. The Mg(2+)-ATPase activity enhanced after chronic and subtoxic ClB exposition. Light microscopy revealed that the adenohypophysis seemed to be more abundant. Results indicate that Wistar rats exposed to subtoxic ClB have direct and indirect effects on hypothalamus-hypophysis-adrenal axis. PMID:26257359

  16. Short Anabolic Peptides for Bone Growth.

    PubMed

    Amso, Zaid; Cornish, Jillian; Brimble, Margaret A

    2016-07-01

    Loss of bone occurs in the age-related skeletal disorder, osteoporosis, leading to bone fragility and increased incidence of fractures, which are associated with enormous costs and substantial morbidity and mortality. Recent data indicate that osteoporotic fractures are more common than other diseases, which usually attract public attention (e.g., heart attack and breast cancer). The prevention and treatment of this skeletal disorder are therefore of paramount importance. Majority of osteoporosis medications restore skeletal balance by reducing osteoclastic activity, thereby reducing bone resorption. These agents, however, do not regenerate damaged bone tissue, leaving limited options for patients once bone loss has occurred. Recently, attention has turned to bone-anabolic agents. Such agents have the ability to increase bone mass and strength, potentially reversing structural damage. To date, only one bone-anabolic drug is available in the market. The discovery of more novel, cost-effective bone anabolic agents is therefore a priority to treat those suffering from this disabling condition. Short peptides offer an important alternative for the development of novel bone-anabolic agents given their high target binding specificity, which translates into potent activity with limited side effects. This review summarizes attempts in the identification of bone-anabolic peptides, and their development for promoting bone growth. PMID:27297498

  17. Hydroxyapatite Growth Inhibition Effect of Pellicle Statherin Peptides.

    PubMed

    Xiao, Y; Karttunen, M; Jalkanen, J; Mussi, M C M; Liao, Y; Grohe, B; Lagugné-Labarthet, F; Siqueira, W L

    2015-08-01

    In our recent studies, we have shown that in vivo-acquired enamel pellicle is a sophisticated biological structure containing a significant portion of naturally occurring salivary peptides. From a functional aspect, the identification of peptides in the acquired enamel pellicle is of interest because many salivary proteins exhibit functional domains that maintain the activities of the native protein. Among the in vivo-acquired enamel pellicle peptides that have been newly identified, 5 peptides are derived from statherin. Here, we assessed the ability of these statherin pellicle peptides to inhibit hydroxyapatite crystal growth. In addition, atomistic molecular dynamics (MD) simulations were performed to better understand the underlying physical mechanisms of hydroxyapatite growth inhibition. A microplate colorimetric assay was used to quantify hydroxyapatite growth. Statherin protein, 5 statherin-derived peptides, and a peptide lacking phosphate at residues 2 and 3 were analyzed. Statherin peptide phosphorylated on residues 2 and 3 indicated a significant inhibitory effect when compared with the 5 other peptides (P < 0.05). MD simulations showed a strong affinity and fast adsorption to hydroxyapatite for phosphopeptides, whereas unphosphorylated peptides interacted weakly with the hydroxyapatite. Our data suggest that the presence of a covalently linked phosphate group (at residues 2 and 3) in statherin peptides modulates the effect of hydroxyapatite growth inhibition. This study provides a mechanism to account for the composition and function of acquired enamel pellicle statherin peptides that will contribute as a base for the development of biologically stable and functional synthetic peptides for therapeutic use against dental caries and/or periodontal disease. PMID:26116492

  18. Central stimulation of hormone release and the proliferative response of lymphocytes in humans.

    PubMed

    Juránková, E; Jezová, D; Vigas, M

    1995-01-01

    The central nervous system (CNS) may communicate with the immune system by direct innervation of lymphoid organs and/or by neurotransmitters and changes in neuroendocrine functioning and hormone release. The consequences of selective transient changes in circulating hormones on immune functioning in humans have not yet been studied. To address this problem, the authors evaluated the lymphoproliferative responses to optimal and suboptimal concentrations of phytohemagglutinin (PHA) and pokeweek mitogen (PWM) under selective enhancement of circulating growth hormone, prolactin, or norepinephrine. The authors failed to demonstrate any effect of elevated growth hormone levels after clonidine challenge on the lymphoproliferative response to mitogens. Similarly, the results did not show any effect of elevated prolactin concentrations induced by domperidone administration on the immune test. Exposure of volunteers to cold resulted in elevation of plasma norepinephrine levels without changes in growth hormone, epinephrine, or cortisol secretion. Cold exposure induced elevation of plasma norepinephrine and reduction of the lymphoproliferative response to the suboptimal dosage of PHA. The reduction was significant 180 and 240 min after exposure. These results are indicative of a relationship between norepinephrine and immunity. PMID:8534322

  19. A high-throughput LC-MS/MS screen for GHRP in equine and human urine, featuring peptide derivatization for improved chromatography.

    PubMed

    Timms, Mark; Hall, Nikki; Levina, Vita; Vine, John; Steel, Rohan

    2014-10-01

    The growth hormone releasing peptides (GHRPs) hexarelin, ipamorelin, alexamorelin, GHRP-1, GHRP-2, GHRP-4, GHRP-5, and GHRP-6 are all synthetic met-enkephalin analogues that include unnatural D-amino acids. They were designed specifically for their ability to stimulate growth hormone release and may serve as performance enhancing drugs. To regulate the use of these peptides within the horse racing industry and by human athletes, a method is presented for the extraction, derivatization, and detection of GHRPs from equine and human urine. This method takes advantage of a highly specific solid-phase extraction combined with a novel derivatization method to improve the chromatography of basic peptides. The method was validated with respect to linearity, repeatability, intermediate precision, specificity, limits of detection, limits of confirmation, ion suppression, and stability. As proof of principle, all eight GHRPs or their metabolites could be detected in urine collected from rats after intravenous administration. PMID:24574167

  20. Natriuretic peptides in the regulation of the hypothalamic-pituitary-adrenal axis.

    PubMed

    Porzionato, Andrea; Macchi, Veronica; Rucinski, Marcin; Malendowicz, Ludwik K; De Caro, Raffaele

    2010-01-01

    Atrial (ANP), brain (BNP), and C-type (CNP) natriuretic peptides act by binding to three main subtypes of receptors, named NPR-A, -B, and -C. NPR-A and NPR-B are coupled with guanylate cyclase. Not only NPR-C is involved in removing natriuretic peptides from the circulation but it also acts through inhibition of adenylyl cyclase. NPR-A binds ANP and BNP; NPR-B preferentially binds CNP; and NPR-C binds all natriuretic peptides with similar affinities. All natriuretic peptides and their receptors are widely present in the hypothalamus, pituitary, adrenal cortex, and medulla. In the hypothalamus, they reduce norepinephrine release, inhibit oxytocin, vasopressin, corticotropin-releasing factor, and luteinizing hormone-releasing hormone release. In the hypophysis, natriuretic peptides inhibit basal and induced ACTH release. Conversely, the effects of natriuretic peptides on secretion of growth, luteinizing, and follicle-stimulating hormones are not clear. Natriuretic peptides are known to inhibit basal and stimulated aldosterone secretion, through an increase of intracellular cGMP, and to inhibit the growth of zona glomerulosa. Inhibition or stimulation of glucocorticoid secretion by adrenocortical cells has been reported on the basis of the species involved, and an indirect effect mediated by adrenalmedullary cells has been hypothesized. In the adrenal medulla, natriuretic peptides inhibit catecholamine release and increase catecholamine uptake. It appears that natriuretic peptides may play a role in the pathophysiology of adrenocortical neoplasias and pheochromocytomas. PMID:20797680

  1. Hydroxyapatite-binding peptides for bone growth and inhibition

    DOEpatents

    Bertozzi, Carolyn R.; Song, Jie; Lee, Seung-Wuk

    2011-09-20

    Hydroxyapatite (HA)-binding peptides are selected using combinatorial phage library display. Pseudo-repetitive consensus amino acid sequences possessing periodic hydroxyl side chains in every two or three amino acid sequences are obtained. These sequences resemble the (Gly-Pro-Hyp).sub.x repeat of human type I collagen, a major component of extracellular matrices of natural bone. A consistent presence of basic amino acid residues is also observed. The peptides are synthesized by the solid-phase synthetic method and then used for template-driven HA-mineralization. Microscopy reveal that the peptides template the growth of polycrystalline HA crystals .about.40 nm in size.

  2. Short Laminin Peptide for Improved Neural Stem Cell Growth

    PubMed Central

    Li, Xiaowei; Liu, Xiaoyan; Josey, Benjamin; Chou, C. James; Tan, Yu; Zhang, Ning

    2014-01-01

    Human neural stem/progenitor cells (hNSCs) are very difficult to culture and require human or animal source extracellular matrix molecules, such as laminin or collagen type IV, to support attachment and to regulate their survival and proliferation. These extracellular matrix molecules are difficult to purify from human or animal tissues, have high batch-to-batch variability, and may cause an immune response if used in clinical applications. Although several laminin- and collagen IV-derived peptides are commercially available, they do not support long-term hNSC attachment and growth. To solve this problem, we developed a novel peptide sequence with only 12 amino acids based on the Ile-Lys-Val-Ala-Val, or IKVAV, sequence: Ac-Cys-Cys-Arg-Arg-Ile-Lys-Val-Ala-Val-Trp-Leu-Cys. This short peptide sequence, similar to tissue-derived full laminin molecules, supported hNSCs to attach and proliferate to confluence for continuous passage and subculture. This short peptide also directed hNSCs to differentiate into neurons. When conjugated to poly(ethylene glycol) hydrogels, this short peptide benefited hNSC attachment and proliferation on the surface of hydrogels and promoted cell migration inside the hydrogels with maximum enhancement at a peptide density of 10 μM. This novel short peptide shows great promise in artificial niche development for supporting hNSC culture in vitro and in vivo and for promoting hNSC transplantation in future clinical therapy. PMID:24692587

  3. USE OF PERIFUSION TO EVALUATE HORMONAL RELEASE IN VITRO FROM RAT PITUITARY AND HYPOTHALAMIC TISSUE

    EPA Science Inventory

    The use of in vitro procedures in reproductive toxicology has permitted a direct assessment of hormonal release from isolated tissue and a means by which to determine, potential sites of toxicant insult. he present chapter describes a perifusion procedure that can be used to eval...

  4. Mink aging is associated with a reduction in ovarian hormone release and the response to FSH and ghrelin.

    PubMed

    Sirotkin, Alexander V; Mertin, Dušan; Süvegová, Karina; Lauričik, Jozef; Morovič, Martin; Harrath, Abdel Halim; Kotwica, Jan

    2016-09-15

    The endocrine mechanisms of mink ovarian hormones release and reproductive aging are poorly investigated. The aims of our study were to: (1) identify hormones produced by mink ovaries (the steroids progesterone [P] and estradiol [E], the peptide hormone oxytocin [OT], and the prostaglandin F [PGF] and prostaglandin E [PGE]); (2) examine the effect of FSH and ghrelin on the release of the hormones listed previously; and (3) understand whether these hormones can be involved in the control of mink reproductive aging, i.e., whether aging can be associated with changes (a) in the basal release of P, E, OT, PGF, or PGE and (b) their response to FSH and ghrelin. Fragments of ovaries of young (yearlings) and old (3-5 years of age) minks were cultured with and without FSH and ghrelin (0, 1, 10, or 100 ng/mL), and the release of hormones was analyzed by EIA/RIA. We found that isolated ovaries were able to release P, E, OT, PGF, and PGE, and the levels of P produced in the ovaries of old animals were lower than those produced in the ovaries of young animals, whereas the levels of other hormones did not differ. FSH was able to stimulate P and E and suppress OT and PGF and did not affect PGE release. Aging was associated with the inhibition of the effect of FSH on ovarian P and E, the appearance of the inhibitory action of FSH on OT, and the disappearance of this action on ovarian PGF. PGE was not affected by FSH, irrespective of animal age. Ghrelin was able to promote E (but not P) and suppress OT, PGF, and PGE output. Aging was associated with the appearance of an inhibitory influence of ghrelin on ovarian OT and PGE and with the disappearance of this influence on PGF output. Aging did not affect the action of ghrelin on ovarian P and E. Our observations (1) confirm the production of P and E and show that OT, PGF, and PGE are released from mink ovaries, (2) confirm the involvement of FSH and demonstrate the involvement of ghrelin in the control of mink ovarian hormone

  5. Differential involvement of signaling pathways in the regulation of growth hormone release by somatostatin and growth hormone-releasing hormone in orange-spotted grouper (Epinephelus coioides).

    PubMed

    Wang, Bin; Qin, Chaobin; Zhang, Cong; Jia, Jirong; Sun, Caiyun; Li, Wensheng

    2014-02-15

    Somatostatin is the most effective inhibitor of GH release, and GHRH was recently identified as one of the primary GH-releasing factors in teleosts. In this study, we analyzed the possible intracellular transduction pathways that are involved in the mechanisms induced by SRIF and GHRH to regulate GH release. Using a pharmacological approach, the blockade of the PLC/IP/PKC pathway reversed the SRIF-induced inhibition of GH release but did not affect the GHRH-induced stimulation of GH release. Furthermore, SRIF reduced the GH release induced by two PKC activators. Inhibitors of the AC/cAMP/PKA pathway reversed both the SRIF- and GHRH-induced effects on GH release. Moreover, the GH release evoked by forskolin and 8-Br-cAMP were completely abolished by SRIF. The blockade of the NOS/NO pathway attenuated the GHRH-induced GH release but had minimal effects on the inhibitory actions of SRIF. In addition, inhibitors of the sGC/cGMP pathway did not modify the SRIF- or GHRH-induced regulation of GH release. Taken together, these findings indicate that the SRIF-induced inhibition of GH release is mediated by both the PLC/IP/PKC and the AC/cAMP/PKA pathways and not by the NOS/NO/sGC/cGMP pathway. In contrast, the GHRH-induced stimulation of GH secretion is mediated by both the AC/cAMP/PKA and the NOS/NO pathways and is independent of the sGC/cGMP pathway and the PLC/IP/PKC system. PMID:24183819

  6. The peptide growth factor, phytosulfokine, attenuates pattern-triggered immunity.

    PubMed

    Igarashi, Daisuke; Tsuda, Kenichi; Katagiri, Fumiaki

    2012-07-01

    Pattern-triggered immunity (PTI) is triggered by recognition of elicitors called microbe-associated molecular patterns (MAMPs). Although immune responses may provide good protection of plants from pathogen attack, excessive immune responses have negative impacts on plant growth and development. Thus, a good balance between positive and negative effects on the immune signaling network is important for plant fitness. However, little information is known about the molecular mechanisms that are involved in attenuation of PTI. Here, we describe a growth-promoting peptide hormone, phytosulfokine (PSK), as attenuating PTI signaling in Arabidopsis. This research was motivated by the observation that expression of the PSK Receptor 1 (PSKR1) gene was induced by MAMP treatment. Plants homozygous for pskr1 T-DNA insertions showed enhanced defense gene expression and seedling growth inhibition triggered by MAMPs. The pskr1 plants also showed enhanced PTI against the bacterial pathogen Pseudomonas syringae. These results indicate that the PSKR-mediated signaling attenuates immune responses. Tyrosyl protein sulfotransferase (TPST) is an enzyme required for production of the mature sulfated PSK. Like pskr1 mutants, a tpst T-DNA insertion line exhibited enhanced MAMP-triggered seedling growth inhibition, which was suppressed by exogenous application of PSK. Thus, PSK signaling mediated by PSKR1 attenuates PTI but stimulates growth. PMID:22353039

  7. Review of Growth Inhibitory Peptide as a biotherapeutic agent for tumor growth, adhesion, and metastasis.

    PubMed

    Muehlemann, M; Miller, K D; Dauphinee, M; Mizejewski, G J

    2005-09-01

    This review surveys the biological activities of an alpha-fetoprotein (AFP) derived peptide termed the Growth Inhibitory Peptide (GIP), which is a synthetic 34 amino acid segment produced from the full length 590 amino acid AFP molecule. The GIP has been shown to be growth-suppressive in both fetal and tumor cells but not in adult terminally-differentiated cells. The mechanism of action of this peptide has not been fully elucidated; however, GIP is highly interactive at the plasma membrane surface in cellular events such as endocytosis, cell contact inhibition and cytoskeleton-induced cell shape changes. The GIP was shown to be growth-suppressive in nine human tumor types and to suppress the spread of tumor infiltrates and metastases in human and mouse mammary cancers. The AFP-derived peptide and its subfragments were also shown to inhibit tumor cell adhesion to extracellular matrix (ECM) proteins and to block platelet aggregation; thus it was expected that the GIP would inhibit cell spreading/migration and metastatic infiltration into host tissues such as lung and pancreas. It was further found that the cyclic versus linear configuration of GIP determined its biological and anti-cancer efficacy. Genbank amino acid sequence identities with a variety of integrin alpha/beta chain proteins supported the GIP's linkage to inhibition of tumor cell adhesion and platelet aggregation. The combined properties of tumor growth suppression, prevention of tumor cell-to-ECM adhesion, and inhibition of platelet aggregation indicate that tumor-to-platelet interactions present promising targets for GIP as an anti-metastatic agent. Finally, based on cholinergic studies, it was proposed that GIP could influence the enzymatic activity of membrane acetylcholinesterases during tumor growth and metastasis. It was concluded that the GIP derived from full-length AFP represents a growth inhibitory motif possessing instrinsic properties that allow it to interfere in cell surface events such

  8. Effect of permeation enhancer pretreatment on the iontophoresis of luteinizing hormone releasing hormone (LHRH) through human epidermal membrane (HEM).

    PubMed

    Smyth, Hugh D C; Becket, Gordon; Mehta, Samir

    2002-05-01

    A 2 x 2 factorial design was performed to determine the effect of a permeation enhancer (oleic acid/propylene glycol), iontophoresis (2 V), and the combination of the two treatments on the permeation enhancement of a model peptide, LHRH (luteinizing hormone releasing hormone), through human epidermal membrane (HEM). In parallel studies, TEAB (tetraethylammonium bromide, a small ionic solute) and sucrose (an electroosmotic flow marker) were also investigated. Structural changes in the HEM were monitored via conductance measurements, differential scanning calorimetry (DSC), and infrared (IR) spectroscopy experiments. LHRH enhancement due to enhancer in combination with iontophoresis (I + E; 29.5 times passive permeability, P), was greater than during iontophoresis alone (I; 14.3) and enhancer treatment alone (E; 3.5). I + E had an additive effect of I and E, indicating the mechanisms of action of the individual enhancement strategies were likely to be located at different sites in the skin. Also, no synergistic enhancement was observed with I + E for either TEAB or sucrose. For TEAB, permeability enhancement due to I (approximately 1400) was much higher than that due to E (14.9), and no additive effect could be detected. For sucrose, E had no effect on either passive or iontophoretic permeability, eliminating the possibility that electroosmosis could explain increases in LHRH permeability. Evidence of synergy between E and I was found, with conductance measurements indicating that I + E synergistically increased the membrane permeability to conducting ions (Na+ and Cl-). It appears these pathways were not available for transport for the solutes used in the current study. DSC and IR investigations showed significant changes in stratum corneum lipid structure following E treatment but not following I. These findings probably arise from the localized action of iontophoresis compared with the bulk action of enhancer. In summary, increased LHRH delivery through HEM in

  9. Effects of a synthetic bioactive peptide on neurite growth and nerve growth factor release in chondroitin sulfate hydrogels.

    PubMed

    Conovaloff, Aaron W; Beier, Brooke L; Irazoqui, Pedro P; Panitch, Alyssa

    2011-01-01

    Previous work has revealed robust dorsal root ganglia neurite growth in hydrogels of chondroitin sulfate. In the current work, it was determined whether addition of a synthetic bioactive peptide could augment neurite growth in these matrices via enhanced binding and sequestering of growth factors. Fluorescence recovery after photobleaching studies revealed that addition of peptide slowed nerve growth factor diffusivity in chondroitin sulfate gels, but not in control gels of hyaluronic acid. Furthermore, cultures of chick dorsal root ganglia in gels of hyaluronic acid or chondroitin sulfate revealed enhanced growth in chondroitin sulfate gels only upon addition of peptide. Taken together, these results suggest a synergistic nerve growth factor-binding activity between this peptide and chondroitin sulfate. PMID:23507745

  10. Active immunization to luteinizing hormone releasing hormone to inhibit the induction of mammary tumors in the rat

    SciTech Connect

    Ravdin, P.M.; Jordan, V.C.

    1988-01-01

    Immunization of female rats with a bovine serum albumin-luteinizing hormone releasing hormone conjugate results in suppression of dimethylbenzanthracene mammary tumor incidence. Tumor incidence was 1.3, and 1.29 tumors per rat in bovine serum albumin alone (n = 10) and unimmunized (n = 18) control groups, but no tumors were found in the bovine serum albumin-luteinizing hormone releasing hormone conjugate immunized animals (n = 10). In a second experiment immunization with bovine serum albumin-luteinizing hormone releasing hormone conjugates reduced tumor incidence to 0.3 tumors per rat (n = 10) from the 1.2 tumors per animal seen in the control animals (n = 10) immunized with bovine serum albumin alone. Bovine serum albumin-luteinizing hormone immunization caused the production of anti-LHRH antibodies, an interruption of estrous cycles, lowered serum estradiol and progesterone levels, and atrophy of the ovaries and uteri. Immunization BSA-hormone conjugates is a novel anti-tumor strategy.

  11. Comparative Effect of ACTH and Related Peptides on Proliferation and Growth of Rat Adrenal Gland

    PubMed Central

    Lotfi, Claudimara Ferini Pacicco; de Mendonca, Pedro O. R.

    2016-01-01

    Pro-opiomelanocortin (POMC) is a polypeptide precursor known to yield biologically active peptides related to a range of functions. These active peptides include the adrenocorticotropic hormone (ACTH), which is essential for maintenance of adrenal growth and steroidogenesis, and the alpha-melanocyte stimulation hormone, which plays a key role in energy homeostasis. However, the role of the highly conserved N-terminal region of POMC peptide fragments has begun to be unraveled only recently. Here, we review the cascade of events involved in regulation of proliferation and growth of murine adrenal cortex triggered by ACTH and other POMC-derived peptides. Key findings regarding signaling pathways and modulation of genes and proteins required for the regulation of adrenal growth are summarized. We have outlined the known mechanisms as well as future challenges for research on the regulation of adrenal proliferation and growth triggered by these peptides. PMID:27242663

  12. Intranasal treatment with luteinising hormone releasing hormone agonist in women with endometriosis.

    PubMed Central

    Shaw, R W; Fraser, H M; Boyle, H

    1983-01-01

    An agonist analogue of luteinising hormone releasing hormone (buserelin) was successfully used to treat women with endometriosis. A dose of 200 micrograms administered intranasally thrice daily was found to be effective in five patients, in whom the endometriotic lesions resolved after six months' treatment. Failure occurred in a sixth patient, who received only 400 micrograms once daily. Anovulation was induced in all subjects together with suppression of menstruation after the first month of treatment. Symptoms of abdominal pain, dysmenorrhoea, and dyspareunia were relieved during treatment, and one previously infertile patient conceived within two months of stopping treatment. No side effects were reported with this dosage, and the results suggest a new form of treatment for patients with endometriosis. PMID:6416542

  13. Targeted Proapoptotic Peptides Depleting Adipose Stromal Cells Inhibit Tumor Growth.

    PubMed

    Daquinag, Alexes C; Tseng, Chieh; Zhang, Yan; Amaya-Manzanares, Felipe; Florez, Fernando; Dadbin, Ali; Zhang, Tao; Kolonin, Mikhail G

    2016-02-01

    Progression of many cancers is associated with tumor infiltration by mesenchymal stromal cells (MSC). Adipose stromal cells (ASC) are MSC that serve as adipocyte progenitors and endothelium-supporting cells in white adipose tissue (WAT). Clinical and animal model studies indicate that ASC mobilized from WAT are recruited by tumors. Direct evidence for ASC function in tumor microenvironment has been lacking due to unavailability of approaches to specifically inactivate these cells. Here, we investigate the effects of a proteolysis-resistant targeted hunter-killer peptide D-WAT composed of a cyclic domain CSWKYWFGEC homing to ASC and of a proapoptotic domain KLAKLAK2. Using mouse bone marrow transplantation models, we show that D-WAT treatment specifically depletes tumor stromal and perivascular cells without directly killing malignant cells or tumor-infiltrating leukocytes. In several mouse carcinoma models, targeted ASC cytoablation reduced tumor vascularity and cell proliferation resulting in hemorrhaging, necrosis, and suppressed tumor growth. We also validated a D-WAT derivative with a proapoptotic domain KFAKFAK2 that was found to have an improved cytoablative activity. Our results for the first time demonstrate that ASC, recruited as a component of tumor microenvironment, support cancer progression. We propose that drugs targeting ASC can be developed as a combination therapy complementing conventional cancer treatments. PMID:26316391

  14. Treatment of nitrosamine-induced pancreatic tumors in hamsters with analogs of somatostatin and luteinizing hormone-releasing hormone

    SciTech Connect

    Paz-Bouza, J.I.; Redding, T.W.; Schally, A.V.

    1987-02-01

    Pancreatic ductal adenocarcinoma was induced in female Syrian golden hamsters by injecting N-nitrosobis(2-oxopropyl)amine (BOP) once a week at a dose of 10 mg per kg of body weight for 18 weeks. Hamsters were then treated with somatostatin analog (RC-160) or with (6-D-tryptophan)luteinizing hormone-releasing hormone ((D-Trp/sup 6/)LH-RH) delayed delivery systems. After 18 weeks of BOP administration, the hamsters were divided into three groups of 10-20 animals each. Group I consisted of untreated controls, group II was injected with RC-160, and group III was injected with (D-Trp/sub 2/)LH-RH. A striking decrease in tumor weight and volume was obtained in animals treated with (D-Trp/sup 6/)LH-RH or with the somatostatin analog RC-160. After 45 days of treatment with either analog, the survival rate was significantly higher in groups II and III (70%), as compared with the control group (35%). The studies, done by light microscopy, high-resolution microscopy, and electron microscopy, showed a decrease in the total number of cancer cells and changes in the epithelium, connective tissue, and cellular organelles in groups II and III treated with the hypothalamic analogs as compared to controls. These results in female hamsters with induced ductal pancreatic tumors confirm and extend the authors findings, obtained in male animals with transplanted tumors, that (D-Trp/sub 6/)LH-RH and somatostatin analogs inhibit the growth of pancreatic cancers.

  15. Self-assembling peptide amphiphiles and related methods for growth factor delivery

    SciTech Connect

    Stupp, Samuel I; Donners, Jack J.J.M.; Silva, Gabriel A; Behanna, Heather A; Anthony, Shawn G

    2013-11-12

    Amphiphilic peptide compounds comprising one or more epitope sequences for binding interaction with one or more corresponding growth factors, micellar assemblies of such compounds and related methods of use.

  16. Self-assembling peptide amphiphiles and related methods for growth factor delivery

    DOEpatents

    Stupp, Samuel I.; Donners, Jack J. J. M.; Silva, Gabriel A.; Behanna, Heather A.; Anthony, Shawn G.

    2009-06-09

    Amphiphilic peptide compounds comprising one or more epitope sequences for binding interaction with one or more corresponding growth factors, micellar assemblies of such compounds and related methods of use.

  17. Self-assembling peptide amphiphiles and related methods for growth factor delivery

    DOEpatents

    Stupp, Samuel I.; Donners, Jack J. J. M.; Silva, Gabriel A.; Behanna, Heather A.; Anthony, Shawn G.

    2012-03-20

    Amphiphilic peptide compounds comprising one or more epitope sequences for binding interaction with one or more corresponding growth factors, micellar assemblies of such compounds and related methods of use.

  18. Inhibition of breast cancer growth and metastasis by a biomimetic peptide

    PubMed Central

    Lee, Esak; Lee, Seung Jae; Koskimaki, Jacob E.; Han, Zheyi; Pandey, Niranjan B.; Popel, Aleksander S.

    2014-01-01

    Metastasis is the main cause of mortality in cancer patients. Though there are many anti-cancer drugs targeting primary tumor growth, anti-metastatic agents are rarely developed. Angiogenesis and lymphangiogenesis are crucial for cancer progression, particularly, lymphangiogenesis is pivotal for metastasis in breast cancer. Here we report that a novel collagen IV derived biomimetic peptide inhibits breast cancer growth and metastasis by blocking angiogenesis and lymphangiogenesis. The peptide inhibits blood and lymphatic endothelial cell viability, migration, adhesion, and tube formation by targeting IGF1R and Met signals. The peptide blocks MDA-MB-231 tumor growth by inhibiting tumor angiogenesis in vivo. Moreover, the peptide inhibits lymphangiogenesis in primary tumors. MDA-MB-231 tumor conditioned media (TCM) was employed to accelerate spontaneous metastasis in tumor xenografts, and the anti-metastatic activity of the peptide was tested in this model. The peptide prevents metastasis to the lungs and lymph nodes by inhibiting TCM-induced lymphangiogenesis and angiogenesis in the pre-metastatic organs. In summary, a novel biomimetic peptide inhibits breast cancer growth and metastasis by blocking angiogenesis and lymphangiogenesis in the pre-metastatic organs as well as primary tumors. PMID:25409905

  19. The role of metabolic state and obestatin in control of chicken ovarian hormone release.

    PubMed

    Sirotkin, Alexander V; Harrath, Abdel Halim; Grossmann, Roland

    2016-08-01

    The aim of the present study was to examine the role and interrelationships between calorie restriction and obestatin in the control of hormone release by chicken ovarian tissue. For this purpose, we compared the release of progesterone (P), testosteron (T), estradiol (E), and arginine-vasotocin (AVT) by ovarian fragments isolated from chicken subjected and not subjested to food restriction, as well as the response of these ovarian fragments to obestatin additions.It was observed that food restriction promoted release of P, reduced output of T, but did not affect basal E and AVT release. Obestatin addition reduced E, promoted AVT, and did not alter P and T release by ovarian tissue isolated from ad libitum fed chicken. In ovarian fragments of fasted hens it reduced E, promoted T, and did not influence P and AVT release.The present observations demonstrate (1) that obestatin can directly control the release of avian ovarian hormones - regulators of reproduction, (2) that metabolic state can control the release of these hormones, and (3) metabolic state can alter the response of ovarian hormones to obestatin. PMID:27030691

  20. Hormone release and behavior during suckling and milking in Gir, Gir x Holstein, and Holstein cows.

    PubMed

    Negrão, J A

    2008-03-01

    There are several different milking management systems in Latin America, because Gir cattle are reputed to be easily stressed and not well adapted to machine-milking. This paper, therefore, provides an overview of hormone release and behavior during suckling and milking in Gir cows and their cross-bred offspring. Several experiments were performed to study oxytocin release during exclusive suckling or exclusive hand- and machine-milking, oxytocin, and prolactin release during a mixed suckling-milking system and oxytocin release after weaning. Cortisol concentrations and behavior were also examined. Concentration of oxytocin, released during suckling, and both types of milking were high, but the maximum concentration measured during suckling was significantly greater than that observed during exclusive milking. In the mixed suckling-milking system, the greatest oxytocin and prolactin releases were measured during suckling. Cortisol concentrations measured before, during, and after milking demonstrated that Gir x Holstein and Holstein cows were not stressed. On the other hand, although Gir had greater concentrations of cortisol, the percentage of residual milk for Gir cows was less than for dairy cows exposed to different stressful situations. In general, Gir cows and their crossbred offspring adapted to machine-milking, although these breeds can react negatively to milkers. Gir, Gir x Holstein, and Holstein cows all had similar cortisol levels during and after milking. PMID:17878278

  1. Glucose absorption, hormonal release and hepatic metabolism after guar gum ingestion

    NASA Technical Reports Server (NTRS)

    Simoes Nunes, C.; Malmlof, K.

    1992-01-01

    Six non-anaesthetized Large White pigs (mean body weight 59 +/- 1.7 kg) were fitted with permanent catheters in the portal vein, the brachiocephalic artery and the right hepatic vein and with electromagnetic flow probes around the portal vein and the hepatic artery. The animals were provided a basal none-fibre diet (diet A) alone or together with 6% guar gum (diet B) or 15% purified cellulose (diet C). The diets were given for 1 week and according to a replicated 3 x 3 latin-square design. On the last day of each adaptation period test meals of 800 g were given prior to blood sampling. The sampling was continued for 8 h. Guar gum strongly reduced the glucose absorption as well as the insulin, gastric inhibitory polypeptide (GIP) and insulin-like growth factor-1 (IGF-1) production. However, the reduction in peripheral blood insulin levels caused by guar gum was not associated with a change in hepatic insulin extraction. IGF-1 appeared to be strongly produced by the gut. The liver had a net uptake of the peptide. Ingestion of guar gum increased the hepatic extraction coefficient of gut produced IGF-1. Guar gum ingestion also appeared to decrease pancreatic glucagon secretion. Cellulose at the level consumed had very little effect on the parameters considered. It is suggested that the modulation of intestinal mechanisms by guar gum was sufficient to mediate the latter internal metabolic effects.

  2. Selected antimicrobial peptides inhibit in vitro growth of Campylobacter spp.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Novel alternatives to traditional antibiotics are urgently needed for food-animal production. A goal of our laboratory is to develop and evaluate antimicrobial peptides (AMP) to control and reduce foodborne pathogens in poultry. AMP have been found in most every class of living organism where they h...

  3. Substantial expression of luteinizing hormone-releasing hormone (LHRH) receptor type I in human uveal melanoma

    PubMed Central

    Schally, Andrew V.; Block, Norman L; Dezso, Balazs; Olah, Gabor; Rozsa, Bernadett; Fodor, Klara; Buglyo, Armin; Gardi, Janos; Berta, Andras; Halmos, Gabor

    2013-01-01

    Uveal melanoma is the most common primary intraocular malignancy in adults, with a very high mortality rate due to frequent liver metastases. Consequently, the therapy of uveal melanoma remains a major clinical challenge and new treatment approaches are needed. For improving diagnosis and designing a rational and effective therapy, it is essential to elucidate molecular characteristics of this malignancy. The aim of this study therefore was to evaluate as a potential therapeutic target the expression of luteinizing hormone-releasing hormone (LHRH) receptor in human uveal melanoma. The expression of LHRH ligand and LHRH receptor transcript forms was studied in 39 human uveal melanoma specimens by RT-PCR using gene specific primers. The binding charachteristics of receptors for LHRH on 10 samples were determined by ligand competition assays. The presence of LHRH receptor protein was further evaluated by immunohistochemistry. The expression of mRNA for type I LHRH receptor was detected in 18 of 39 (46%) of tissue specimens. mRNA for LHRH-I ligand could be detected in 27 of 39 (69%) of the samples. Seven of 10 samples investigated showed high affinity LHRH-I receptors. The specific presence of full length LHRH receptor protein was further confirmed by immunohistochemistry. A high percentage of uveal melanomas express mRNA and protein for type-I LHRH receptors. Our results support the merit of further investigation of LHRH receptors in human ophthalmological tumors. Since diverse analogs of LHRH are in clinical trials or are already used for the treatment of various cancers, these analogs could be considered for the LHRH receptor-based treatment of uveal melanoma. PMID:24077773

  4. Cadmium exerts toxic effects on ovarian steroid hormone release in rats.

    PubMed

    Zhang, Wenchang; Pang, Fen; Huang, Yaqing; Yan, Ping; Lin, Wei

    2008-11-10

    This study examined the toxic effects of cadmium on the function of sexual hormone release in the ovaries of rats and the mechanism of this dysregulation. In vivo, adult female rats were randomly assigned to four groups based on weight. Cadmium was given ip 5 days/week for 6 weeks at doses of 1.0, 0.5, 0.25 and 0mg/kg. Following euthanasia, the ovaries were removed and placed into culture medium for 3h. The levels of progesterone (P) and estadiol (E) in the culture medium were then measured by radioimmunoassay. In vitro studies were done using the ovaries of adult rats in different stages of estrous (proestrus, estrus, metestrus and diestrus). Individual ovaries were collected, placed into culture medium and exposed to 0, 0.1, 1, or 2mM of CdCl(2) for 3h, at which time the levels of P and E in the ovary culture serum were determined by radioimmunoassay. The in vivo results showed that the levels of P and E in the ovary culture serum (5.3+/-1.4 ng/ml and 1.4+/-0.4 pg/ml, respectively) decreased significantly in the high dose group compared to the control (9.2+/-0.9 ng/ml and 3.9+/-0.7 pg/ml, respectively). In vitro, there were significant differences in P and E in between the different concentrations of cadmium and also between the different stages of the estrous cycle. These data suggest that cadmium can inhibit P and E release in ovaries. This may represent an important mechanism of endocrine disruption. PMID:18708132

  5. Regulation of luteinizing hormone-releasing hormone and luteinizing hormone secretion by hypothalamic amino acids.

    PubMed

    Donoso, A O; Seltzer, A M; Navarro, C E; Cabrera, R J; López, F J; Negro-Vilar, A

    1994-04-01

    1. The present review discusses the proposed roles of the amino acids glutamate and GABA in the central regulation of luteinizing hormone-releasing hormone (LHRH) and in luteinizing hormone (LH) secretion. 2. Descriptions of the mechanisms of action of these neurotransmitters have focused on two diencephalic areas, namely, the preoptic-anterior hypothalamic area where the cell bodies of LHRH neurons are located, and the medial basal hypothalamus which contains the nerve endings of the LHRH system. Increasing endogenous GABA concentration by drugs, GABA agonists, or blockade of glutamatergic neurotransmission by selective antagonists in rats and non-human primates prevents ovulation and pulsatile LH release, and blunts the LH surges induced by estrogen or an estrogen-progesterone combination. In contrast, glutamate and different glutamate agonists such as NMDA, AMPA and kainate, can increase LHRH/LH secretion. 3. The simultaneous enhancement of glutamatergic activity and a decrease of GABAergic tone may positively influence the maturation of the pituitary-gonadal system in rats and non-human primates. Administration of glutamate receptor agonists has been shown to significantly advance the onset of puberty. Conversely, glutamate antagonists or increased endogenous GABA levels may delay the onset of puberty. The physiological regulation of LHRH/LH secretion may thus involve a GABA-glutamate interaction and a cooperative action of the various types of ionotropic glutamate receptors. 4. The inhibitory actions of GABA on LH release and ovulation may be exerted at the level of afferent nerve terminals that regulate LHRH secretion. A likely candidate is noradrenaline, as suggested by the synaptic connections between noradrenergic nerve terminals and GABAergic interneurons in the preoptic area. Recent experiments have provided complementary evidence for the physiological balance between inhibitory and excitatory transmission resulting in modulation of the action of

  6. Identification of major urinary metabolites of nafarelin acetate, a potent agonist of luteinizing hormone-releasing hormone, in the rhesus monkey

    SciTech Connect

    Chan, R.L.; Chaplin, M.D.

    1985-09-01

    Nafarelin acetate (less than Glu-His-Trp-Ser-Tyr-3-(2-naphthyl)-D-Ala-Leu-Arg-Pro-Gly-NH2) is a potent agonistic analogue of luteinizing hormone-releasing hormone. After a single iv administration of nafarelin acetate (with UC label at C-3 of 3-(2-naphthyl)-D-Ala) to female rhesus monkeys, about 80% of the radioactivity was eliminated in urine. Five major radioactive urinary metabolites were isolated and purified by reversed phase HPLC. Four of these metabolites, identified by amino acid analysis, were short peptides: the 5-10-hexapeptide amide, the 6-10-pentapeptide amide, the 5-7-tripeptide, and the 6-7-dipeptide. The fifth metabolite, which accounted for about 15% of the radioactivity administered, was shown by NMR and mass spectrometry to be 2-naphthylacetic acid. A possible pathway of its formation is by oxidative deamination of 3-(2-napthyl)-D-Ala to give the corresponding alpha-keto acid, followed by oxidative decarboxylation of the alpha-keto acid. These five metabolites together accounted for about 70% of the radioactivity recovered in the urine of rhesus monkeys, or more than half of the radioactivity in the administered dose. Nafarelin acetate was also present in small amounts. Several of these metabolites were also present in plasma of the rhesus monkey.

  7. The in vitro biological effect of nerve growth factor is inhibited by synthetic peptides.

    PubMed Central

    Longo, F M; Vu, T K; Mobley, W C

    1990-01-01

    Nerve growth factor (NGF)1 is a neurotrophic polypeptide that acts via specific receptors to promote the survival and growth of neurons. To delineate the NGF domain(s) responsible for eliciting biological activity, we synthesized small peptides corresponding to three regions in NGF that are hydrophilic and highly conserved. Several peptides from mouse NGF region 26-40 inhibited the neurite-promoting effect of NGF on sensory neurons in vitro. Inhibition was sequence-specific and could be overcome by increasing the concentration of NGF. Moreover, peptide actions were specific for NGF-mediated events in that they failed to block the neurotrophic activity of ciliary neuronotrophic factor (CNTF) or phorbol 12-myristate 13-acetate (PMA). In spite of the inhibition of NGF activity, peptides did not affect the binding of radiolabeled NGF. These studies define one region of NGF that may be required for neurotrophic activity. Images PMID:2100197

  8. A novel spider peptide toxin suppresses tumor growth through dual signaling pathways.

    PubMed

    Liu, Z; Deng, M; Xiang, J; Ma, H; Hu, W; Zhao, Y; Li, D W-C; Liang, S

    2012-12-01

    Spider venom is a large pharmacological repertoire containing many biologically active peptides, which may have a potent therapeutic implication. Here we investigated a peptide toxin, named lycosin-I, isolated from the venom of the spider Lycosa singoriensis. In contrast to most spider peptide toxins adopting inhibitor cystine knot (ICK) motif, lycosin-I shows a linear amphipathic alpha-helical conformation, common to α-helical host defense peptides. Lycosin-I displays strong ability to inhibit cancer cell growth in vitro and can effectively suppresses tumor growth in vivo. Mechanistically, it activates the mitochondrial death pathway to sensitize cancer cells for apoptosis, as well as up-regulates p27 to inhibit cell proliferation. Taken together, our results provide the first evidence that a spider toxin can effectively suppress tumorigenesis through activation of dual signaling pathways. In addition, lycosin-I may be a useful structural lead for the development of novel anticancer drugs. PMID:22882120

  9. Targeted in vivo photodynamic therapy with epidermal growth factor receptor-specific peptide linked nanoparticles.

    PubMed

    Narsireddy, Amreddy; Vijayashree, Kurra; Irudayaraj, Joseph; Manorama, Sunkara V; Rao, Nalam M

    2014-08-25

    In targeted photodynamic therapy (tPDT), photosensitizers (PS) are targeted to disease tissue to reduce the dosage of PS and in addition to reduce the photo damage to the non-target tissue. We synthesized iron oxide nanoparticles (NP) armored with tumor targeting peptide and PS for targeted PDT. Chitosan covered Fe3O4 NPs (30 nm) were deposited with gold NPs to generate two distinct chemical surfaces. To the gold particles PS was attached with a lipoic acid linker. Human epidermal growth factor receptor (hEGFR)-specific peptide was also attached to the same particles via a nickel-nitrilotriacetic acid linker attached to the chitosan. Using these nanoparticles, peptide specific uptake and PDT mediated cell death of the SK-OV-3 cells (Her2(+) positive cells) were demonstrated by confocal microscopy, T2 imaging and viability assays. Peptide mediated preferential distribution of these NPs into tumor tissue was also shown in a xenograft tumor model. After one intravenous injection and one PDT dose, peptide bound NPs retarded tumor growth significantly compared to dark controls or treatments with NPs without peptide. The tumor retardation by targeted NPs was achieved at a PS concentration of 3.9 nmol/animal, whereas similar effect was seen with free PS at 220 nmol/animal. Therapeutic potential of these peptide containing NPs would be a useful in targeted PDT and in imaging the target tissue. PMID:24939618

  10. Inhibition of Growth and Gene Expression by PNA-peptide Conjugates in Streptococcus pyogenes

    PubMed Central

    Patenge, Nadja; Pappesch, Roberto; Krawack, Franziska; Walda, Claudia; Mraheil, Mobarak Abu; Jacob, Anette; Hain, Torsten; Kreikemeyer, Bernd

    2013-01-01

    While Streptococcus pyogenes is consistently susceptible toward penicillin, therapeutic failure of penicillin treatment has been reported repeatedly and a considerable number of patients exhibit allergic reactions to this substance. At the same time, streptococcal resistance to alternative antibiotics, e.g., macrolides, has increased. Taken together, these facts demand the development of novel therapeutic strategies. In this study, S. pyogenes growth was inhibited by application of peptide-conjugated antisense-peptide nucleic acids (PNAs) specific for the essential gyrase A gene (gyrA). Thereby, HIV-1 Tat peptide-coupled PNAs were more efficient inhibitors of streptococcal growth as compared with (KFF)3K-coupled PNAs. Peptide-anti-gyrA PNAs decreased the abundance of gyrA transcripts in S. pyogenes. Growth inhibition by antisense interference was enhanced by combination of peptide-coupled PNAs with protein-level inhibitors. Antimicrobial synergy could be detected with levofloxacin and novobiocin, targeting the gyrase enzyme, and with spectinomycin, impeding ribosomal function. The prospective application of carrier peptide-coupled antisense PNAs in S. pyogenes covers the use as an antimicrobial agent and the employment as a knock-down strategy for the investigation of virulence factor function. PMID:24193033

  11. Anti-tumor effects of peptide analogs targeting neuropeptide hormone receptors on mouse pheochromocytoma cells.

    PubMed

    Ziegler, C G; Ullrich, M; Schally, A V; Bergmann, R; Pietzsch, J; Gebauer, L; Gondek, K; Qin, N; Pacak, K; Ehrhart-Bornstein, M; Eisenhofer, G; Bornstein, S R

    2013-05-22

    Pheochromocytoma is a rare but potentially lethal chromaffin cell tumor with currently no effective treatment. Peptide hormone receptors are frequently overexpressed on endocrine tumor cells and can be specifically targeted by various anti-tumor peptide analogs. The present study carried out on mouse pheochromocytoma cells (MPCs) and a more aggressive mouse tumor tissue-derived (MTT) cell line revealed that these cells are characterized by pronounced expression of the somatostatin receptor 2 (sst2), growth hormone-releasing hormone (GHRH) receptor and the luteinizing hormone-releasing hormone (LHRH) receptor. We further demonstrated significant anti-tumor effects mediated by cytotoxic somatostatin analogs, AN-162 and AN-238, by LHRH antagonist, Cetrorelix, by the cytotoxic LHRH analog, AN-152, and by recently developed GHRH antagonist, MIA-602, on MPC and for AN-152 and MIA-602 on MTT cells. Studies of novel anti-tumor compounds on these mouse cell lines serve as an important basis for mouse models of metastatic pheochromocytoma, which we are currently establishing. PMID:23267837

  12. Lactobacillus gasseri requires peptides, not proteins or free amino acids, for growth in milk.

    PubMed

    Arakawa, K; Matsunaga, K; Takihiro, S; Moritoki, A; Ryuto, S; Kawai, Y; Masuda, T; Miyamoto, T

    2015-03-01

    Lactobacillus gasseri is a widespread commensal lactic acid bacterium inhabiting human mucosal niches and has many beneficial effects as a probiotic. However, L. gasseri is difficult to grow in milk, which hurts usability for the food industry. It had been previously reported that supplementation with yeast extract or proteose peptone, including peptides, enables L. gasseri to grow well in milk. In this study, our objective was to confirm peptide requirement of L. gasseri and evaluate efficacy of peptide release by enzymatic proteolysis on growth of L. gassei in milk. Three strains of L. gasseri did not grow well in modified DeMan, Rogosa, Sharpe broth without any nitrogen sources (MRS-N), but addition of a casein-derived peptide mixture, tryptone, promoted growth. In contrast, little effect was observed after adding casein or a casein-derived amino acid mixture, casamino acids. These results indicate that L. gasseri requires peptides, not proteins or free amino acids, among milk-derived nitrogen sources for growth. Lactobacillus gasseri JCM 1131T hardly had growth capacity in 6 kinds of milk-based media: bovine milk, human milk, skim milk, cheese whey, modified MRS-N (MRSL-N) supplemented with acid whey, and MRSL-N supplemented with casein. Moreover, treatment with digestive proteases, particularly pepsin, to release peptides made it grow well in each milk-based medium. The pepsin treatment was the most effective for growth of strain JCM 1131T in skim milk among the tested food-grade proteases such as trypsin, α-chymotrypsin, calf rennet, ficin, bromelain, and papain. As well as strain JCM 1131T, pepsinolysis of milk improved growth of other L. gasseri strains and some strains of enteric lactobacilli such as Lactobacillus crispatus, Lactobacillus gallinarum, Lactobacillus johnsonii, and Lactobacillus reuteri. These results suggest that some relatives of L. gasseri also use peptides as desirable nitrogen sources, and that milk may be a good supplier of nutritious

  13. Radioimmunoassay for 6-D-tryptophan analog of luteinizing hormone-releasing hormone: measurement of serum levels after administration of long-acting microcapsule formulations

    SciTech Connect

    Mason-Garcia, M.; Vigh, S.; Comaru-Schally, A.M.; Redding, T.W.; Somogyvari-Vigh, A.; Horvath, J.; Schally, A.V.

    1985-03-01

    A sensitive and specific radioimmunoassay for (6-D-tryptophan)luteinizing hormone-releasing hormone ((D-Trp/sup 6/)LH-RH) was developed and used for following the rate of liberation of (D-Trp/sup 6/)LH-RH from a long-acting delivery systems based on a microcapsule formulation. Rabbit antibodies were generated against (D-Trp/sup 6/)LH-RH conjugated to bovine serum albumin with glutaraldehyde. Crossreactivity with LH-RH was less than 1%; there was no significant cross-reactivity with other peptides. The minimal detectable dose of (D-Trp/sup 6/)LH-RH was 2 pg per tube. In tra- and interassay coefficients of variation were 8% and 10%, respectively. The radioimmunoassay was suitable for direct determination of (D-Trp/sup 6/)LH-RH in serum, permitting the study of blood levels of the analog after single injections into normal men and after one-a-month administration of microcapsules to rats. In men, 90 min after subcutaneous injection of 250 ..mu..g of the peptide, serum (D-Trp/sup 6/)LH-RH rose to 6-12 ng/ml. Luteinizing hormone was increased 90 min and 24 hr after the administration of the analog. Several batches of microcapsules were tested in rats and the rate of release of (D-Trp/sup 6/)LH-RH was followed. The improved batch of microcapsules of (D-Trp/sup 6/)LH-RH increased serum concentrations of the analog for 30 days or longer after intramuscular injection.

  14. A mitogenic peptide amide encoded within the E peptide domain of the insulin-like growth factor IB prohormone.

    PubMed Central

    Siegfried, J M; Kasprzyk, P G; Treston, A M; Mulshine, J L; Quinn, K A; Cuttitta, F

    1992-01-01

    We have identified an amino acid sequence within the E peptide of the insulin-like growth factor IB (IGF-IB) precursor that is biologically active and designated this peptide insulin-like growth factor IB-(103-124) E1 amide (IBE1). Its existence was predicted by a flanking Gly-Lys-Lys-Lys, a signal sequence for sequential proteolytic cleavage and peptidyl C-terminal amidation. A synthetic analog of the predicted IBE1 peptide, designated Y-23-R-NH2, was generated with tyrosine added at position 0. This peptide at 2-20 nM had growth-promoting effects on both normal and malignant human bronchial epithelial cells. Y-23-R-NH2 bound to specific high-affinity receptors (Kd = 2.8 +/- 1.4 x 10(-11) M) present at 1-2 x 10(4) binding sites per cell. Ligand binding was not inhibited by recombinant insulin or recombinant IGF-I. Furthermore, a monoclonal antibody antagonist to the IGF-I receptor (alpha IR3) did not suppress the proliferative response induced by Y-23-R-NH2. In addition, C-terminal amidation was shown to be important in receptor recognition since the free-acid analog of IBE1 (Y-23-R-OH) did not effectively compete for binding and was not a potent agonist of proliferation. Immunoblot analysis of human lung tumor cell line extracts using an antibody raised against Y-23-R-NH2 detected a low molecular mass band of approximately 5 kDa, implying that a protein product is produced that has immunological similarity to IBE1. Extracts of human, mammalian, and avian livers analyzed on an immunoblot with the anti-Y-23-R-NH2 antibody contained proteins of approximately 21 kDa that were specifically recognized by the antiserum and presumably represent an IGF-I precursor molecule. This implies that in species where an IGF-I mRNA with homology to the human IGF-IB E domain has not yet been described, an alternate mRNA must be produced that contains a sequence similar to that of the midportion of the human IGF-IB E domain. Our findings demonstrate that IBE1 is a growth factor that

  15. Length-dependent β-sheet growth mechanisms of polyalanine peptides in water and on hydrophobic surfaces

    NASA Astrophysics Data System (ADS)

    Mu, Yan; Tang, Binqing; Yu, Meng

    2014-03-01

    Fibrillar assemblies by peptides are becoming one of the most promising nanomaterials due to their exceptional properties. The self-assembly of peptides into β sheets is a critical step in the fibrillization pathway. We investigated the length-dependent β-sheet growth mechanisms of polyalanine [poly(A)] peptides consisting of 6 to 24 alanines (A6 to A24) in water and on the hydrophobic surface, respectively, by molecular dynamics simulations. β-sheet growth behavior in water fits negative exponential growth model, showing that β-sheet growth rate decays exponentially with time. Meanwhile, increasing chain length leads to an accelerated decay of the β-sheet growth rate. By contrast, β-sheet growth on the surface from A6 to A18 occurs in two consecutive stages, both of which fit linear growth models. β-sheet growth rate in the first stage increases as chain length is increased, while the intermediate length peptide A12 has the highest β-sheet growth rate in the second stage. β-sheet growth behavior of A24 on the surface still fits negative exponential model. Overall, the hydrophobic surface accelerates β-sheet growth by enhancing local concentration and reducing conformational entropy of poly(A) peptide, and the β-sheet growth of the intermediate length peptide A12 is the fastest on the surface. Our simulation results shed light on understanding the accelerated peptide fibrillization on the hydrophobic surface.

  16. Electrospun PELCL membranes loaded with QK peptide for enhancement of vascular endothelial cell growth.

    PubMed

    Yang, Yang; Yang, Qingmao; Zhou, Fang; Zhao, Yunhui; Jia, Xiaoling; Yuan, Xiaoyan; Fan, Yubo

    2016-06-01

    One of the major challenges in tissue engineering of small-diameter vascular grafts is to inhibit intimal hyperplasia and keep long-term patency after implantation. Rapid endothelialization of the grafts could be an effective approach. In this study, QK, a peptide mimicking vascular endothelial growth factor, was selected as the bioactive substrate and loaded in electrospun membranes for enhancement of vascular endothelial cell growth. In detail, QK peptide was firstly introduced with poly(ethylene glycol) diacrylate into a thiolated chitosan solution that could transfer into hydrogel. Then, suspensions or emulsions of poly(ethylene glycol)-b-poly(L-lactide-co-ε-caprolactone) (PELCL) containing QK peptide (with or without chitosan hydrogel) were electrospun into fibrous membranes. For comparison, the electrospun PELCL membrane without QK was also fabricated. Results of release behaviors showed that the electrospun membranes, especially that contained chitosan hydrogel prepared by suspension electrospinning, could successfully encapsulate QK peptide and maintain its secondary structure after released. In vitro cell culture studies exhibited that the release of QK peptide could accelerate the proliferation of vascular endothelial cells in the 9 days. It was suggested that the electrospun PELCL membranes loaded with QK peptide might have potential applications in vascular tissue engineering. PMID:27107890

  17. A novel leptin antagonist peptide inhibits breast cancer growth in vitro and in vivo

    PubMed Central

    Catalano, Stefania; Leggio, Antonella; Barone, Ines; De Marco, Rosaria; Gelsomino, Luca; Campana, Antonella; Malivindi, Rocco; Panza, Salvatore; Giordano, Cinzia; Liguori, Alessia; Bonofiglio, Daniela; Liguori, Angelo; Andò, Sebastiano

    2015-01-01

    The role of the obesity cytokine leptin in breast cancer progression has raised interest in interfering with leptin's actions as a valuable therapeutic strategy. Leptin interacts with its receptor through three different binding sites: I–III. Site I is crucial for the formation of an active leptin–leptin receptor complex and in its subsequent activation. Amino acids 39-42 (Leu-Asp-Phe-Ile- LDFI) were shown to contribute to leptin binding site I and their mutations in alanine resulted in muteins acting as typical antagonists. We synthesized a small peptide based on the wild-type sequence of leptin binding site I (LDFI) and evaluated its efficacy in antagonizing leptin actions in breast cancer using in vitro and in vivo experimental models. The peptide LDFI abolished the leptin-induced anchorage-dependent and -independent growth as well as the migration of ERα-positive (MCF-7) and -negative (SKBR3) breast cancer cells. These results were well correlated with a reduction in the phosphorylation levels of leptin downstream effectors, as JAK2/STAT3/AKT/MAPK. Importantly, the peptide LDFI reversed the leptin-mediated up-regulation of its gene expression, as an additional mechanism able to enhance the peptide antagonistic activity. The described effects were specific for leptin signalling, since the developed peptide was not able to antagonize the other growth factors' actions on signalling activation, proliferation and migration. Finally, we showed that the LDFI pegylated peptide markedly reduced breast tumour growth in xenograft models. The unmodified peptide LDFI acting as a full leptin antagonist could become an attractive option for breast cancer treatment, especially in obese women. PMID:25721149

  18. Delivering heparin-binding insulin-like growth factor 1 with self-assembling peptide hydrogels.

    PubMed

    Florine, Emily M; Miller, Rachel E; Liebesny, Paul H; Mroszczyk, Keri A; Lee, Richard T; Patwari, Parth; Grodzinsky, Alan J

    2015-02-01

    Heparin-binding insulin-like growth factor 1 (HB-IGF-1) is a fusion protein of IGF-1 with the HB domain of heparin-binding epidermal growth factor-like growth factor. A single dose of HB-IGF-1 has been shown to bind specifically to cartilage and to promote sustained upregulation of proteoglycan synthesis in cartilage explants. Achieving strong integration between native cartilage and tissue-engineered cartilage remains challenging. We hypothesize that if a growth factor delivered by the tissue engineering scaffold could stimulate enhanced matrix synthesis by both the cells within the scaffold and the adjacent native cartilage, integration could be enhanced. In this work, we investigated methods for adsorbing HB-IGF-1 to self-assembling peptide hydrogels to deliver the growth factor to encapsulated chondrocytes and cartilage explants cultured with growth factor-loaded hydrogels. We tested multiple methods for adsorbing HB-IGF-1 in self-assembling peptide hydrogels, including adsorption prior to peptide assembly, following peptide assembly, and with/without heparan sulfate (HS, a potential linker between peptide molecules and HB-IGF-1). We found that HB-IGF-1 and HS were retained in the peptide for all tested conditions. A subset of these conditions was then studied for their ability to stimulate increased matrix production by gel-encapsulated chondrocytes and by chondrocytes within adjacent native cartilage. Adsorbing HB-IGF-1 or IGF-1 prior to peptide assembly was found to stimulate increased sulfated glycosaminoglycan per DNA and hydroxyproline content of chondrocyte-seeded hydrogels compared with basal controls at day 10. Cartilage explants cultured adjacent to functionalized hydrogels had increased proteoglycan synthesis at day 10 when HB-IGF-1 was adsorbed, but not IGF-1. We conclude that delivery of HB-IGF-1 to focal defects in cartilage using self-assembling peptide hydrogels is a promising technique that could aid cartilage repair via enhanced matrix

  19. Inhibition of cell growth by a hypothalamic peptide.

    PubMed Central

    Redding, T W; Schally, A V

    1982-01-01

    A fraction purified from acetic acid extracts of porcine hypothalami was found to contain significant antimitogenic activity when tested in normal and neoplastic cell lines. Addition of this hypothalamic material (1-100 micrograms/ml) to culture media significantly inhibited [3H]thymidine incorporation into cellular DNA in several cell lines. Amino acid incorporation into pituitary proteins and uridine incorporation into RNA were also significantly reduced by this factor(s). Addition to the culture media of this hypothalamic material at 5 micrograms/ml and 50 micrograms/ml per day decreased by 17% and 36%, respectively, cell numbers of 3T6 fibroblast cell cultures. Time-response curves showed that the inhibition of [3H]thymidine incorporation into DNA in 3T6 fibroblast cells begins within 2 hr after adding this fraction to the culture medium. The inhibitory action cannot be explained by a direct cytotoxic effect since 3T6 cells labeled with 51Cr and incubated for 6 hr in the presence of this hypothalamic fraction fail to show an increase in the release of 51Cr into the medium as compared with controls. Incubation with trypsin and chymotrypsin completely abolished the antimitogenic activity of this material and pepsin decreased it. This strongly suggests that the antimitogenic activity exhibited by this fraction is due to a polypeptide(s). These observations provide evidence for the presence in the mammalian hypothalamus of an antimitogenic peptide(s) that may be involved in the regulation of cell proliferation. PMID:6757925

  20. Inhibitory Effects of Synthetic Peptides Containing Bovine Lactoferrin C-lobe Sequence on Bacterial Growth

    PubMed Central

    Kim, Woan-Sub; Ohashi, Midori; Shimazaki, Kei-ichi

    2016-01-01

    Lactoferrin is a glycoprotein with various biological effects, with antibacterial activity being one of the first effects reported. This glycoprotein suppresses bacterial growth through bacteriostatic or bactericidal action. It also stimulates the growth of certain kinds of bacteria such as lactic acid bacteria and bifidobacteria. In this study, Asn-Leu-Asn-Arg was selected and chemically synthesized based on the partial sequences of bovine lactoferrin tryptic fragments. Synthetic Asn-Leu-Asn-Arg suppressed the growth of Pseudomonas fluorescens, P. syringae and Escherichia coli. P. fluorescens is a major psychrotrophic bacteria found in raw and pasteurized milk, which decreases milk quality. P. syringae is a harmful infectious bacterium that damages plants. However, synthetic Asn-Leu-Asn-Arg did not inhibit the growth of Lactobacillus acidophilus. It is expected that this synthetic peptide would be the first peptide sequence from the bovine lactoferrin C-lobe that shows antibacterial activity. PMID:27621684

  1. Inhibitory Effects of Synthetic Peptides Containing Bovine Lactoferrin C-lobe Sequence on Bacterial Growth.

    PubMed

    Kim, Woan-Sub; Ohashi, Midori; Shimazaki, Kei-Ichi

    2016-01-01

    Lactoferrin is a glycoprotein with various biological effects, with antibacterial activity being one of the first effects reported. This glycoprotein suppresses bacterial growth through bacteriostatic or bactericidal action. It also stimulates the growth of certain kinds of bacteria such as lactic acid bacteria and bifidobacteria. In this study, Asn-Leu-Asn-Arg was selected and chemically synthesized based on the partial sequences of bovine lactoferrin tryptic fragments. Synthetic Asn-Leu-Asn-Arg suppressed the growth of Pseudomonas fluorescens, P. syringae and Escherichia coli. P. fluorescens is a major psychrotrophic bacteria found in raw and pasteurized milk, which decreases milk quality. P. syringae is a harmful infectious bacterium that damages plants. However, synthetic Asn-Leu-Asn-Arg did not inhibit the growth of Lactobacillus acidophilus. It is expected that this synthetic peptide would be the first peptide sequence from the bovine lactoferrin C-lobe that shows antibacterial activity. PMID:27621684

  2. Glucagon-like peptide 2 may mediate growth and development of the bovine gastrointestinal tract

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glucagon-like peptide 2 (GLP-2), secreted by enteroendocrine cells, promotes growth, reduces apoptosis, and enhances blood flow, nutrient absorption, and barrier function in intestinal epithelium of monogastric species. Regulatory functions of GLP-2 in the ruminant gastrointestinal tract (GIT) are u...

  3. Expression of neuropeptide hormone receptors in human adrenal tumors and cell lines: antiproliferative effects of peptide analogues.

    PubMed

    Ziegler, C G; Brown, J W; Schally, A V; Erler, A; Gebauer, L; Treszl, A; Young, L; Fishman, L M; Engel, J B; Willenberg, H S; Petersenn, S; Eisenhofer, G; Ehrhart-Bornstein, M; Bornstein, S R

    2009-09-15

    Peptide analogues targeting various neuropeptide receptors have been used effectively in cancer therapy. A hallmark of adrenocortical tumor formation is the aberrant expression of peptide receptors relating to uncontrolled cell proliferation and hormone overproduction. Our microarray results have also demonstrated a differential expression of neuropeptide hormone receptors in tumor subtypes of human pheochromocytoma. In light of these findings, we performed a comprehensive analysis of relevant receptors in both human adrenomedullary and adrenocortical tumors and tested the antiproliferative effects of peptide analogues targeting these receptors. Specifically, we examined the receptor expression of somatostatin-type-2 receptor, growth hormone-releasing hormone (GHRH) receptor or GHRH receptor splice variant-1 (SV-1) and luteinizing hormone-releasing hormone (LHRH) receptor at the mRNA and protein levels in normal human adrenal tissues, adrenocortical and adrenomedullary tumors, and cell lines. Cytotoxic derivatives of somatostatin AN-238 and, to a lesser extent, AN-162, reduced cell numbers of uninduced and NGF-induced adrenomedullary pheochromocytoma cells and adrenocortical cancer cells. Both the splice variant of GHRH receptor SV-1 and the LHRH receptor were also expressed in adrenocortical cancer cell lines but not in the pheochromocytoma cell line. The GHRH receptor antagonist MZ-4-71 and LHRH antagonist Cetrorelix both significantly reduced cell growth in the adrenocortical cancer cell line. In conclusion, the expression of receptors for somatostatin, GHRH, and LHRH in the normal human adrenal and in adrenal tumors, combined with the growth-inhibitory effects of the antitumor peptide analogues, may make possible improved treatment approaches to adrenal tumors. PMID:19717419

  4. Evidence that cells expressing luteinizing hormone-releasing hormone mRNA in the mouse are derived from progenitor cells in the olfactory placode

    SciTech Connect

    Wray, S.; Grant, P.; Gainer, H. )

    1989-10-01

    In situ hybridization histochemistry and immunocytochemistry were used to study the prenatal expression of luteinizing hormone-releasing hormone (LHRH) cells in the mouse. Cells expressing LHRH mRNA and peptide product were first detected on embryonic day 11.5 (E11.5) in the olfactory pit. On E12.5, the majority of LHRH cells were located on tracks extending from the olfactory pit to the base of the telencephalon. From E12.5 to E15.5, LHRH cells were detected in a rostral-to-caudal gradient in forebrain areas. Prior to E12.5, cells expressing LHRH mRNA were not detected in forebrain areas known to contain LHRH cells in postnatal animals. Quantitation of cells expressing LHRH mRNA showed that the number of labeled cells on E12.5 (approximately 800) equaled the number of LHRH cells in postnatal animals, but more than 90% of these cells were located in nasal regions. Between E12.5 and E15.5, the location of LHRH cells shifted. The number of LHRH cells in the forebrain increased, while the number of LHRH cells in nasal regions decreased over this same period. These findings establish that cells first found in the olfactory pit and thereafter in forebrain areas express the LHRH gene and correspond to the position of LHRH immunopositive cells found at these developmental times. To further examine the ontogeny of the LHRH system, immunocytochemistry in combination with (3H)thymidine autoradiography was used to determine when LHRH cells left the mitotic cycle. We show that LHRH neurons exhibit a discrete time of birth, suggesting that they arise as a single neuronal population between E10.0 and E11.0. Postnatal LHRH neurons were birth-dated shortly after differentiation of the olfactory placode and before LHRH mRNA was expressed in cells in the olfactory pit.

  5. Pulsatile growth hormone secretion in patients with acromegaly and normal men: the effects of growth hormone-releasing hormone infusion.

    PubMed

    Gelato, M C; Oldfield, E; Loriaux, D L; Merriam, G R

    1990-09-01

    Twenty-four GH secretory patterns were studied before and during continuous infusions of GHRH in six patients with active acromegaly and in six normal adult men. GH release was episodic in both groups. Control subjects showed a normal diurnal variation in GH release, with the majority of GH released at night (2200-0800 h); mean levels were 1.5 +/- 0.4 (SE) ng/mL (day) and 4.2 +/- 0.8 ng/mL (night). Acromegalics had no diurnal variation in GH; levels were 45.3 +/- 13.7 ng/mL (day) and 39.8 +/- 12.2 ng/mL (night). Acromegalics demonstrated an increased frequency of GH pulses compared to normals (11.8 +/- 0.8 vs. 2.2 +/- 0.3/24 h). During continuous 24-h infusions of GHRH, the normal subjects continued to show a diurnal variation in GH release, but GH pulse frequency increased to a rate (11.7 +/- 1.4 pulses/24 h) very similar to that of the patients with acromegaly. In contrast, GHRH infusion did not alter the GH pulse frequency in the acromegalics. GHRH increased the mean levels of GH in both groups (patients 80.2 +/- 20.3 vs. 41.0 +/- 12.1 ng/mL, x +/- SE. P less than 0.05; controls 10.2 +/- 2.0 vs. 3.33 +/- 0.5 ng/mL, P less than 0.01). Some of the patients with acromegaly showed a progressive decline in GH levels during the infusion period, suggesting desensitization or exhaustion of releaseable stores; however, GH levels remained above basal values in all patients. After the 24-h GHRH infusions, the GH response to a bolus of GHRH was diminished in the normal subjects (2.1 +/- 0.9 vs. 16.8 +/- 5 ng/mL, x +/- SE; P less than 0.01) but not in the acromegalic patients (30.2 +/- 8.9 vs. 35.5 +/- 12.5 ng/mL; NS). These results indicate that GH release is episodic under basal conditions and during continuous GHRH infusion in both acromegalic and normal subjects, indicating the importance of other modulators of GH release, such as somatostatin, which may remain pulsatile even in acromegaly. PMID:2118536

  6. LHRH-Conjugated Lytic Peptides Directly Target Prostate Cancer Cells

    PubMed Central

    Yates, Clayton; Sharp, Starlette; Jones, Jacqueline; Topps, Daphne; Coleman, Mathew; Aneja, Ritu; Jaynes, Jesse; Turner, Timothy

    2010-01-01

    Prostate cancer is the second leading cause of cancer deaths among men. For patients with hormone-refractory disease, few treatments are available once the tumor has metastasized beyond the prostate. In the present study, two conjugated lytic peptide sequences (named JCHLHRH and JC21LHRH) were designed to target luteinizing hormone-releasing hormone receptors (LHRH-R). Our results indicate that human prostate cancer cell lines were sensitive to both LHRH-conjugated and non-conjugated lytic peptides, with IC50 concentrations for LNCaP cells, 4.4 and 9.1 µM; for DU-145 cells, 4.8 and 5.7 µM; and for PC-3 cells, 4.4 and 8.2 µM, respectively. JCHLHRH and JC21LHRH were nontoxic to normal primary human prostate epithelial cells or to bone marrow stromal cells in co-culture. There were morphological changes in PC-3 cells after 3 hr of exposure to either peptide; after 6 hr, there were significant reductions in cell numbers. Exposure of PC-3 cells for 24 hr to either JCHLHRH or JC21LHRH blocked their growth over 3 days. Since JCHLHRH and JC21LHRH have specificity for and anti-proliferative activity against tumor cells, and low toxicity for normal prostate cells, these peptides could serve as a new type of therapy for prostate cancer. PMID:20869347

  7. Thiol-disulfide exchange in peptides derived from human growth hormone.

    PubMed

    Chandrasekhar, Saradha; Epling, Daniel E; Sophocleous, Andreas M; Topp, Elizabeth M

    2014-04-01

    Disulfide bonds stabilize proteins by cross-linking distant regions into a compact three-dimensional structure. They can also participate in hydrolytic and oxidative pathways to form nonnative disulfide bonds and other reactive species. Such covalent modifications can contribute to protein aggregation. Here, we present experimental data for the mechanism of thiol-disulfide exchange in tryptic peptides derived from human growth hormone in aqueous solution. Reaction kinetics was monitored to investigate the effect of pH (6.0-10.0), temperature (4-50°C), oxidation suppressants [ethylenediaminetetraacetic acid (EDTA) and N2 sparging], and peptide secondary structure (amide cyclized vs. open form). The concentrations of free thiol containing peptides, scrambled disulfides, and native disulfide-linked peptides generated via thiol-disulfide exchange and oxidation reactions were determined using reverse-phase HPLC and liquid chromatography-mass spectrometry. Concentration versus time data were fitted to a mathematical model using nonlinear least squares regression analysis. At all pH values, the model was able to fit the data with R(2) ≥ 0.95. Excluding oxidation suppressants (EDTA and N2 sparging) resulted in an increase in the formation of scrambled disulfides via oxidative pathways but did not influence the intrinsic rate of thiol-disulfide exchange. In addition, peptide secondary structure was found to influence the rate of thiol-disulfide exchange. PMID:24549831

  8. Growth-Blocking Peptides As Nutrition-Sensitive Signals for Insulin Secretion and Body Size Regulation.

    PubMed

    Koyama, Takashi; Mirth, Christen K

    2016-02-01

    In Drosophila, the fat body, functionally equivalent to the mammalian liver and adipocytes, plays a central role in regulating systemic growth in response to nutrition. The fat body senses intracellular amino acids through Target of Rapamycin (TOR) signaling, and produces an unidentified humoral factor(s) to regulate insulin-like peptide (ILP) synthesis and/or secretion in the insulin-producing cells. Here, we find that two peptides, Growth-Blocking Peptide (GBP1) and CG11395 (GBP2), are produced in the fat body in response to amino acids and TOR signaling. Reducing the expression of GBP1 and GBP2 (GBPs) specifically in the fat body results in smaller body size due to reduced growth rate. In addition, we found that GBPs stimulate ILP secretion from the insulin-producing cells, either directly or indirectly, thereby increasing insulin and insulin-like growth factor signaling activity throughout the body. Our findings fill an important gap in our understanding of how the fat body transmits nutritional information to the insulin producing cells to control body size. PMID:26928023

  9. Growth-Blocking Peptides As Nutrition-Sensitive Signals for Insulin Secretion and Body Size Regulation

    PubMed Central

    Koyama, Takashi; Mirth, Christen K.

    2016-01-01

    In Drosophila, the fat body, functionally equivalent to the mammalian liver and adipocytes, plays a central role in regulating systemic growth in response to nutrition. The fat body senses intracellular amino acids through Target of Rapamycin (TOR) signaling, and produces an unidentified humoral factor(s) to regulate insulin-like peptide (ILP) synthesis and/or secretion in the insulin-producing cells. Here, we find that two peptides, Growth-Blocking Peptide (GBP1) and CG11395 (GBP2), are produced in the fat body in response to amino acids and TOR signaling. Reducing the expression of GBP1 and GBP2 (GBPs) specifically in the fat body results in smaller body size due to reduced growth rate. In addition, we found that GBPs stimulate ILP secretion from the insulin-producing cells, either directly or indirectly, thereby increasing insulin and insulin-like growth factor signaling activity throughout the body. Our findings fill an important gap in our understanding of how the fat body transmits nutritional information to the insulin producing cells to control body size. PMID:26928023

  10. Peptides of Matrix Gla Protein Inhibit Nucleation and Growth of Hydroxyapatite and Calcium Oxalate Monohydrate Crystals

    PubMed Central

    Goiko, Maria; Dierolf, Joshua; Gleberzon, Jared S.; Liao, Yinyin; Grohe, Bernd; Goldberg, Harvey A.; de Bruyn, John R.; Hunter, Graeme K.

    2013-01-01

    Matrix Gla protein (MGP) is a phosphorylated and γ-carboxylated protein that has been shown to prevent the deposition of hydroxyapatite crystals in the walls of blood vessels. MGP is also expressed in kidney and may inhibit the formation of kidney stones, which mainly consist of another crystalline phase, calcium oxalate monohydrate. To determine the mechanism by which MGP prevents soft-tissue calcification, we have synthesized peptides corresponding to the phosphorylated and γ-carboxylated sequences of human MGP in both post-translationally modified and non-modified forms. The effects of these peptides on hydroxyapatite formation and calcium oxalate crystallization were quantified using dynamic light scattering and scanning electron microscopy, respectively. Peptides YGlapS (MGP1-14: YγEpSHEpSMEpSYELNP), YEpS (YEpSHEpSMEpSYELNP), YGlaS (YγESHESMESYELNP) and SK-Gla (MGP43-56: SKPVHγELNRγEACDD) inhibited formation of hydroxyapatite in order of potency YGlapS > YEpS > YGlaS > SK-Gla. The effects of YGlapS, YEpS and YGlaS on hydroxyapatite formation were on both crystal nucleation and growth; the effect of SK-Gla was on nucleation. YGlapS and YEpS significantly inhibited the growth of calcium oxalate monohydrate crystals, while simultaneously promoting the formation of calcium oxalate dihydrate. The effects of these phosphopeptides on calcium oxalate monohydrate formation were on growth of crystals rather than nucleation. We have shown that the use of dynamic light scattering allows inhibitors of hydroxyapatite nucleation and growth to be distinguished. We have also demonstrated for the first time that MGP peptides inhibit the formation of calcium oxalate monohydrate. Based on the latter finding, we propose that MGP function not only to prevent blood-vessel calcification but also to inhibit stone formation in kidney. PMID:24265810

  11. Splicing of distant peptide fragments occurs in the proteasome by transpeptidation and produces the spliced antigenic peptide derived from fibroblast growth factor-5.

    PubMed

    Dalet, Alexandre; Vigneron, Nathalie; Stroobant, Vincent; Hanada, Ken-Ichi; Van den Eynde, Benoît J

    2010-03-15

    Peptide splicing is a newly described mode of production of antigenic peptides presented by MHC class I molecules, whereby two noncontiguous fragments of the parental protein are joined together after excision of the intervening segment. Three spliced peptides have been described. In two cases, splicing involved the excision of a short intervening segment of 4 or 6 aa and was shown to occur in the proteasome by transpeptidation resulting from the nucleophilic attack of an acyl-enzyme intermediate by the N terminus of the other peptide fragment. For the third peptide, which is derived from fibroblast growth factor-5 (FGF-5), the splicing mechanism remains unknown. In this case, the intervening segment is 40 aa long. This much greater length made the transpeptidation model more difficult to envision. Therefore, we evaluated the role of the proteasome in the splicing of this peptide. We observed that the spliced FGF-5 peptide was produced in vitro after incubation of proteasomes with a 49-aa-long precursor peptide. We evaluated the catalytic mechanism by incubating proteasomes with various precursor peptides. The results confirmed the transpeptidation model of splicing. By transfecting a series of mutant FGF-5 constructs, we observed that reducing the length of the intervening segment increased the production of the spliced peptide, as predicted by the transpeptidation model. Finally, we observed that trans-splicing (i.e., splicing of fragments from two distinct proteins) can occur in the cell, but with a much lower efficacy than splicing of fragments from the same protein. PMID:20154207

  12. Calcium carbonate crystal growth beneath Langmuir monolayers of acidic β-hairpin peptides.

    PubMed

    Gong, Haofei; Yang, Yi; Pluntke, Manuela; Marti, Othmar; Majer, Zsuzsa; Sewald, Norbert; Volkmer, Dirk

    2014-11-28

    Four amphiphilic peptides with designed hairpin structure were synthesized and their monolayers were employed as model systems to study biologically inspired calcium carbonate crystallization. Langmuir monolayers of hairpin peptides were investigated by surface pressure area isotherms, surface potential isotherms, Brewster angle microscopy (BAM), atomic force microscopy (AFM) and Fourier transform infrared (FTIR) spectroscopy. A β-hairpin conformation was found for all peptides at the air-water interface although their packing arrangements seem to be different. Crystallization of calcium carbonate under these peptide monolayers was investigated at different surface pressures and growth times both by in situ optical microscopy, BAM and ex situ investigations such as scanning electron microscopy (SEM) and transmission electron microscopy (TEM). An amorphous calcium carbonate precursor was found at the initial crystallization stage. The crystallization process occurred in three stages. It starts from the nucleation of amorphous particles being a kinetically controlled process. Crystal nuclei subsequently aggregate to large particles and vaterite crystals start to form inside the amorphous layer, with the monolayer fluidity exerting an important role. The third process includes the re-crystallization of vaterite to calcite, which is thermodynamically controlled by monolayer structural factors including the monolayer flexibility and packing arrangement of the polar headgroups. Thus, the kinetic factors, monolayer fluidity and flexibility as well as structure factors govern the crystal morphology and polymorph distribution simultaneously and synergistically. PMID:25292256

  13. Signature motif-guided identification of receptors for peptide hormones essential for root meristem growth.

    PubMed

    Song, Wen; Liu, Li; Wang, Jizong; Wu, Zhen; Zhang, Heqiao; Tang, Jiao; Lin, Guangzhong; Wang, Yichuan; Wen, Xing; Li, Wenyang; Han, Zhifu; Guo, Hongwei; Chai, Jijie

    2016-06-01

    Peptide-mediated cell-to-cell signaling has crucial roles in coordination and definition of cellular functions in plants. Peptide-receptor matching is important for understanding the mechanisms underlying peptide-mediated signaling. Here we report the structure-guided identification of root meristem growth factor (RGF) receptors important for plant development. An assay based on a signature ligand recognition motif (Arg-x-Arg) conserved in a subfamily of leucine-rich repeat receptor kinases (LRR-RKs) identified the functionally uncharacterized LRR-RK At4g26540 as a receptor of RGF1 (RGFR1). We further solved the crystal structure of RGF1 in complex with the LRR domain of RGFR1 at a resolution of 2.6 Å, which reveals that the Arg-x-Gly-Gly (RxGG) motif is responsible for specific recognition of the sulfate group of RGF1 by RGFR1. Based on the RxGG motif, we identified additional four RGFRs. Participation of the five RGFRs in RGF-induced signaling is supported by biochemical and genetic data. We also offer evidence showing that SERKs function as co-receptors for RGFs. Taken together, our study identifies RGF receptors and co-receptors that can link RGF signals with their downstream components and provides a proof of principle for structure-based matching of LRR-RKs with their peptide ligands. PMID:27229311

  14. Receptor binding peptides for target-selective delivery of nanoparticles encapsulated drugs

    PubMed Central

    Accardo, Antonella; Aloj, Luigi; Aurilio, Michela; Morelli, Giancarlo; Tesauro, Diego

    2014-01-01

    Active targeting by means of drug encapsulated nanoparticles decorated with targeting bioactive moieties represents the next frontier in drug delivery; it reduces drug side effects and increases the therapeutic index. Peptides, based on their chemical and biological properties, could have a prevalent role to direct drug encapsulated nanoparticles, such as liposomes, micelles, or hard nanoparticles, toward the tumor tissues. A considerable number of molecular targets for peptides are either exclusively expressed or overexpressed on both cancer vasculature and cancer cells. They can be classified into three wide categories: integrins; growth factor receptors (GFRs); and G-protein coupled receptors (GPCRs). Therapeutic agents based on nanovectors decorated with peptides targeting membrane receptors belonging to the GPCR family overexpressed by cancer cells are reviewed in this article. The most studied targeting membrane receptors are considered: somatostatin receptors; cholecystokinin receptors; receptors associated with the Bombesin like peptides family; luteinizing hormone-releasing hormone receptors; and neurotensin receptors. Nanovectors of different sizes and shapes (micelles, liposomes, or hard nanoparticles) loaded with doxorubicin or other cytotoxic drugs and externally functionalized with natural or synthetic peptides are able to target the overexpressed receptors and are described based on their formulation and in vitro and in vivo behaviors. PMID:24741304

  15. Temporally controlled release of multiple growth factors from a self-assembling peptide hydrogel.

    PubMed

    Bruggeman, Kiara F; Rodriguez, Alexandra L; Parish, Clare L; Williams, Richard J; Nisbet, David R

    2016-09-23

    Protein growth factors have demonstrated great potential for tissue repair, but their inherent instability and large size prevents meaningful presentation to biologically protected nervous tissue. Here, we create a nanofibrous network from a self-assembling peptide (SAP) hydrogel to carry and stabilize the growth factors. We significantly reduced growth factor degradation to increase their lifespan by over 40 times. To control the temporal release profile we covalently attached polysaccharide chitosan molecules to the growth factor to increase its interactions with the hydrogel nanofibers and achieved a 4 h delay, demonstrating the potential of this method to provide temporally controlled growth factor delivery. We also describe release rate based analysis to examine the growth factor delivery in more detail than standard cumulative release profiles allow and show that the chitosan attachment method provided a more consistent release profile with a 60% reduction in fluctuations. To prove the potential of this system as a complex growth factor delivery platform we demonstrate for the first time temporally distinct release of multiple growth factors from a single tissue specific SAP hydrogel: a significant goal in regenerative medicine. PMID:27517970

  16. Temporally controlled release of multiple growth factors from a self-assembling peptide hydrogel

    NASA Astrophysics Data System (ADS)

    Bruggeman, Kiara F.; Rodriguez, Alexandra L.; Parish, Clare L.; Williams, Richard J.; Nisbet, David R.

    2016-09-01

    Protein growth factors have demonstrated great potential for tissue repair, but their inherent instability and large size prevents meaningful presentation to biologically protected nervous tissue. Here, we create a nanofibrous network from a self-assembling peptide (SAP) hydrogel to carry and stabilize the growth factors. We significantly reduced growth factor degradation to increase their lifespan by over 40 times. To control the temporal release profile we covalently attached polysaccharide chitosan molecules to the growth factor to increase its interactions with the hydrogel nanofibers and achieved a 4 h delay, demonstrating the potential of this method to provide temporally controlled growth factor delivery. We also describe release rate based analysis to examine the growth factor delivery in more detail than standard cumulative release profiles allow and show that the chitosan attachment method provided a more consistent release profile with a 60% reduction in fluctuations. To prove the potential of this system as a complex growth factor delivery platform we demonstrate for the first time temporally distinct release of multiple growth factors from a single tissue specific SAP hydrogel: a significant goal in regenerative medicine.

  17. Therapeutic effects of cell-permeant peptides that activate G proteins downstream of growth factors

    PubMed Central

    Ma, Gary S.; Aznar, Nicolas; Kalogriopoulos, Nicholas; Midde, Krishna K.; Lopez-Sanchez, Inmaculada; Sato, Emi; Dunkel, Ying; Gallo, Richard L.; Ghosh, Pradipta

    2015-01-01

    In eukaryotes, receptor tyrosine kinases (RTKs) and trimeric G proteins are two major signaling hubs. Signal transduction via trimeric G proteins has long been believed to be triggered exclusively by G protein-coupled receptors (GPCRs). This paradigm has recently been challenged by several studies on a multimodular signal transducer, Gα-Interacting Vesicle associated protein (GIV/Girdin). We recently demonstrated that GIV’s C terminus (CT) serves as a platform for dynamic association of ligand-activated RTKs with Gαi, and for noncanonical transactivation of G proteins. However, exogenous manipulation of this platform has remained beyond reach. Here we developed cell-permeable GIV-CT peptides by fusing a TAT-peptide transduction domain (TAT-PTD) to the minimal modular elements of GIV that are necessary and sufficient for activation of Gi downstream of RTKs, and used them to engineer signaling networks and alter cell behavior. In the presence of an intact GEF motif, TAT-GIV-CT peptides enhanced diverse processes in which GIV’s GEF function has previously been implicated, e.g., 2D cell migration after scratch-wounding, invasion of cancer cells, and finally, myofibroblast activation and collagen production. Furthermore, topical application of TAT-GIV-CT peptides enhanced the complex, multireceptor-driven process of wound repair in mice in a GEF-dependent manner. Thus, TAT-GIV peptides provide a novel and versatile tool to manipulate Gαi activation downstream of growth factors in a diverse array of pathophysiologic conditions. PMID:25926659

  18. Enhancing Peptide Ligand Binding to Vascular Endothelial Growth Factor by Covalent Bond Formation

    PubMed Central

    Marquez, Bernadette V.; Beck, Heather E.; Aweda, Tolulope A.; Phinney, Brett; Holsclaw, Cynthia; Jewell, William; Tran, Diana; Day, Jeffrey J.; Peiris, Malalage N.; Nwosu, Charles; Lebrilla, Carlito; Meares, Claude F.

    2012-01-01

    Formation of a stable covalent bond between a synthetic probe molecule and a specific site on a target protein has many potential applications in biomedical science. For example, the properties of probes used as receptor-imaging ligands may be improved by increasing their residence time on the targeted receptor. Among the more interesting cases are peptide ligands, the strongest of which typically bind to receptors with micromolar dissociation constants, and which may depend on processes other than simple binding to provide images. The side chains of cysteine, histidine, or lysine are attractive for chemical attachment to improve binding to a receptor protein, and a system based on acryloyl probes attaching to engineered cysteine provides excellent positron emission tomographic images in animal models (Wei et al. (2008) J. Nucl. Med. 49, 1828-1835). In nature, lysine is a more common but less reactive residue than cysteine, making it an interesting challenge to modify. To seek practically useful cross-linking yields with naturally occurring lysine side chains, we have explored not only acryloyl but also other reactive linkers with different chemical properties. We employed a peptide-VEGF model system to discover that a 19mer peptide ligand, which carried a lysine-tagged dinitrofluorobenzene group, became attached stably and with good yield to a unique lysine residue on human vascular endothelial growth factor (VEGF), even in the presence of 70% fetal bovine serum. The same peptide carrying acryloyl and related Michael acceptors gave low yields of attachment to VEGF, as did the chloroacetyl peptide. PMID:22537066

  19. 60 YEARS OF POMC: N-terminal POMC peptides and adrenal growth.

    PubMed

    Bicknell, Andrew B

    2016-05-01

    The peptide hormones contained within the sequence of proopiomelanocortin (POMC) have diverse roles ranging from pigmentation to regulation of adrenal function to control of our appetite. It is generally acknowledged to be the archetypal hormone precursor, and as its biology has been unravelled, so too have many of the basic principles of hormone biosynthesis and processing. This short review focuses on one group of its peptide products, namely, those derived from the N-terminal of POMC and their role in the regulation of adrenal growth. From a historical and a personal perspective, it describes how their role in regulating proliferation of the adrenal cortex was identified and also highlights the key questions that remain to be answered. PMID:26759392

  20. AGE-RELATED ALTERATIONS IN THE STIMULATED RELEASE IN VITRO OF CATECHOLAMINES AND LUTEINIZING HORMONE-RELEASING HORMONE FROM THE MALE RAT HYPOTHALAMUS

    EPA Science Inventory

    Using an in vitro perifusion system, the present study investigated the possibility that alterations in catecholamine and luteinizing hormone-releasing hormone (LHRH) secretion from the male rat mediobasal hypothalamus are present during the period of middle-age. The results indi...

  1. The effect of luteinizing hormone releasing hormone analog regime and stage of oocyte maturity for induced ovulation of channel catfish Ictalurus punctatus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effective LHRHa (luteinizing hormone releasing hormone analog) dose based on the gonadal maturity of channel catfish, Ictalurus punctatus to optimize channel x blue hybrid catfish production was evaluated in 4 trials (twice in early part of the season and twice in the peak spawning season) in a ...

  2. Effect of carp pituitary extract and luteinizing hormone releasing analog hormone on reproductive indices and spawning of 3-year-old channel catfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The efficacy of carp pituitary extract (CPE) and luteinizing hormone releasing hormone (LHRHa) treatments to induce spawning in young-adult channel catfish undergoing first oogenesis just prior to the spawning season was evaluated in four commercial strains of channel catfish. Prior to injection of ...

  3. Amino Acid Metaclusters: Implications of Growth Trends on Peptide Self-Assembly and Structure.

    PubMed

    Do, Thanh D; de Almeida, Natália E C; LaPointe, Nichole E; Chamas, Ali; Feinstein, Stuart C; Bowers, Michael T

    2016-01-01

    Ion-mobility mass spectrometry is utilized to examine the metacluster formation of serine, asparagine, isoleucine, and tryptophan. These amino acids are representative of different classes of noncharged amino acids. We show that they can form relatively large metaclusters in solution that are difficult or impossible to observe by traditional solution techniques. We further demonstrate, as an example, that the formation of Ser metaclusters is not an ESI artifact because large metaclusters can be detected in negative polarity and low concentration with similar cross sections to those measured in positive polarity and higher concentration. The growth trends of tryptophan and isoleucine metaclusters, along with serine, asparagine, and the previously studied phenylalanine, are balanced among various intrinsic properties of individual amino acids (e.g., hydrophobicity, size, and shape). The metacluster cross sections of hydrophilic residues (Ser, Asn, Trp) tend to stay on or fall below the isotropic model trend lines whereas those of hydrophobic amino acids (Ile, Phe) deviate positively from the isotropic trend lines. The growth trends correlate well to the predicted aggregation propensity of individual amino acids. From the metacluster data, we introduce a novel approach to score and predict aggregation propensity of peptides, which can offer a significant improvement over the existing methods in terms of accuracy. Using a set of hexapeptides, we show that the strong negative deviations of Ser metaclusters from the isotropic model leads a prediction of microcrystalline formation for the SFSFSF peptide, whereas the strong positive deviation of Ile leads to prediction or fibril formation for the NININI peptide. Both predictions are confirmed experimentally using ion mobility and TEM measurements. The peptide SISISI is predicted to only weakly aggregate, a prediction confirmed by TEM. PMID:26632663

  4. Phthalocyanine-Peptide Conjugates for Epidermal Growth Factor Receptor Targeting1

    PubMed Central

    Ongarora, Benson G.; Fontenot, Krystal R.; Hu, Xiaoke; Sehgal, Inder; Satyanarayana-Jois, Seetharama D.; Vicente, M. Graça H.

    2012-01-01

    Four phthalocyanine (Pc)-peptide conjugates designed to target the epidermal growth factor receptor (EGFR) were synthesized and evaluated in vitro using four cell lines: human carcinoma A431 and HEp2, human colorectal HT-29, and kidney Vero (negative control) cells. Two peptide ligands for EGFR were investigated: EGFR-L1 and -L2, bearing 6 and 13 amino acid residues, respectively. The peptides and Pc-conjugates were shown to bind to EGFR using both theoretical (Autodock) and experimental (SPR) investigations. The Pc-EGFR-L1 conjugates 5a and 5b efficiently targeted EGFR and were internalized, in part due to their cationic charge, whereas the uncharged Pc-EGFR-L2 conjugates 4b and 6a poorly targeted EGFR maybe due to their low aqueous solubility. All conjugates were non-toxic (IC50 > 100 µM) to HT-29 cells, both in the dark and upon light activation (1 J/cm2). Intravenous (iv) administration of conjugate 5b into nude mice bearing A431 and HT-29 human tumor xenografts resulted in a near-IR fluorescence signal at ca. 700 nm, 24 h after administration. Our studies show that Pc-EGFR-L1 conjugates are promising near-IR fluorescent contrast agents for CRC, and potentially other EGFR over-expressing cancers. PMID:22468711

  5. Generation and Recovery of β-cell Spheroids From Step-growth PEG-peptide Hydrogels

    PubMed Central

    Raza, Asad; Lin, Chien-Chi

    2012-01-01

    Hydrogels are hydrophilic crosslinked polymers that provide a three-dimensional microenvironment with tissue-like elasticity and high permeability for culturing therapeutically relevant cells or tissues. Hydrogels prepared from poly(ethylene glycol) (PEG) derivatives are increasingly used for a variety of tissue engineering applications, in part due to their tunable and cytocompatible properties. In this protocol, we utilized thiol-ene step-growth photopolymerizations to fabricate PEG-peptide hydrogels for encapsulating pancreatic MIN6 b-cells. The gels were formed by 4-arm PEG-norbornene (PEG4NB) macromer and a chymotrypsin-sensitive peptide crosslinker (CGGYC). The hydrophilic and non-fouling nature of PEG offers a cytocompatible microenvironment for cell survival and proliferation in 3D, while the use of chymotrypsin-sensitive peptide sequence (CGGY↓C, arrow indicates enzyme cleavage site, while terminal cysteine residues were added for thiol-ene crosslinking) permits rapid recovery of cell constructs forming within the hydrogel. The following protocol elaborates techniques for: (1) Encapsulation of MIN6 β-cells in thiol-ene hydrogels; (2) Qualitative and quantitative cell viability assays to determine cell survival and proliferation; (3) Recovery of cell spheroids using chymotrypsin-mediated gel erosion; and (4) Structural and functional analysis of the recovered spheroids. PMID:23241531

  6. Histone H4-related osteogenic growth peptide (OGP): a novel circulating stimulator of osteoblastic activity.

    PubMed Central

    Bab, I; Gazit, D; Chorev, M; Muhlrad, A; Shteyer, A; Greenberg, Z; Namdar, M; Kahn, A

    1992-01-01

    It has been established that regenerating marrow induces an osteogenic response in distant skeletal sites and that this activity is mediated by factors released into the circulation by the healing tissue. In the present study we have characterized one of these factors, a 14 amino acid peptide named osteogenic growth peptide (OGP). Synthetic OGP, identical in structure to the native molecule, stimulates the proliferation and alkaline phosphatase activity of osteoblastic cells in vitro and increases bone mass in rats when injected in vivo. Immunoreactive OGP in high abundance is present physiologically in the serum, mainly in the form of an OGP-OGP binding protein complex. A marked increase in serum bound and unbound OGP accompanies the osteogenic phase of post-ablation marrow regeneration and associated systemic osteogenic response. Authentic OGP is identical to the C-terminus of histone H4 and shares a five residue motif with a T-cell receptor beta-chain V-region and the Bacillus subtilis outB locus. Since these latter proteins have not been implicated previously in the control of cell proliferation or differentiation, OGP may belong to a novel, heretofore unrecognized family of regulatory peptides. Perhaps more importantly, OGP appears to represent a new class of molecules involved in the systemic control of osteoblast proliferation and differentiation. Images PMID:1582415

  7. Alzheimer amyloid peptide aβ42 regulates gene expression of transcription and growth factors.

    PubMed

    Barucker, Christian; Sommer, Anette; Beckmann, Georg; Eravci, Murat; Harmeier, Anja; Schipke, Carola G; Brockschnieder, Damian; Dyrks, Thomas; Althoff, Veit; Fraser, Paul E; Hazrati, Lili-Naz; George-Hyslop, Peter St; Breitner, John C S; Peters, Oliver; Multhaup, Gerhard

    2015-01-01

    The pathogenesis of Alzheimer's disease (AD) is characterized by the aggregation of amyloid-β (Aβ) peptides leading to deposition of senile plaques and a progressive decline of cognitive functions, which currently remains the main criterion for its diagnosis. Robust biomarkers for AD do not yet exist, although changes in the cerebrospinal fluid levels of tau and Aβ represent promising candidates in addition to brain imaging and genetic risk profiling. Although concentrations of soluble Aβ42 correlate with symptoms of AD, less is known about the biological activities of Aβ peptides which are generated from the amyloid-β protein precursor. An unbiased DNA microarray study showed that Aβ42, at sub-lethal concentrations, specifically increases expression of several genes in neuroblastoma cells, notably the insulin-like growth factor binding proteins 3 and 5 (IGFBP3/5), the transcription regulator inhibitor of DNA binding, and the transcription factor Lim only domain protein 4. Using qRT-PCR, we confirmed that mRNA levels of the identified candidate genes were exclusively increased by the potentially neurotoxic Aβ42 wild-type peptide, as both the less toxic Aβ40 and a non-toxic substitution peptide Aβ42 G33A did not affect mRNA levels. In vivo immunohistochemistry revealed a corresponding increase in both hippocampal and cortical IGFBP5 expression in an AD mouse model. Proteomic analyses of human AD cerebrospinal fluid displayed increased in vivo concentrations of IGFBPs. IGFBPs and transcription factors, as identified here, are modulated by soluble Aβ42 and may represent useful early biomarkers. PMID:25318543

  8. Hedgehog signaling activation induces stem cell proliferation and hormone release in the adult pituitary gland

    PubMed Central

    Pyczek, Joanna; Buslei, Rolf; Schult, David; Hölsken, Annett; Buchfelder, Michael; Heß, Ina; Hahn, Heidi; Uhmann, Anja

    2016-01-01

    Hedgehog (HH) signaling is known to be essential during the embryonal development of the pituitary gland but the knowledge about its role in the adult pituitary and in associated tumors is sparse. In this report we investigated the effect of excess Hh signaling activation in murine pituitary explants and analyzed the HH signaling status of human adenopituitary lobes and a large cohort of pituitary adenomas. Our data show that excess Hh signaling led to increased proliferation of Sox2+ and Sox9+ adult pituitary stem cells and to elevated expression levels of adrenocorticotropic hormone (Acth), growth hormone (Gh) and prolactin (Prl) in the adult gland. Inhibition of the pathway by cyclopamine reversed these effects indicating that active Hh signaling positively regulates proliferative processes of adult pituitary stem cells and hormone production in the anterior pituitary. Since hormone producing cells of the adenohypophysis as well as ACTH-, GH- and PRL-immunopositive adenomas express SHH and its target GLI1, we furthermore propose that excess HH signaling is involved in the development/maintenance of hormone-producing pituitary adenomas. These findings advance the understanding of physiological hormone regulation and may open new treatment options for pituitary tumors. PMID:27109116

  9. Hedgehog signaling activation induces stem cell proliferation and hormone release in the adult pituitary gland.

    PubMed

    Pyczek, Joanna; Buslei, Rolf; Schult, David; Hölsken, Annett; Buchfelder, Michael; Heß, Ina; Hahn, Heidi; Uhmann, Anja

    2016-01-01

    Hedgehog (HH) signaling is known to be essential during the embryonal development of the pituitary gland but the knowledge about its role in the adult pituitary and in associated tumors is sparse. In this report we investigated the effect of excess Hh signaling activation in murine pituitary explants and analyzed the HH signaling status of human adenopituitary lobes and a large cohort of pituitary adenomas. Our data show that excess Hh signaling led to increased proliferation of Sox2(+) and Sox9(+) adult pituitary stem cells and to elevated expression levels of adrenocorticotropic hormone (Acth), growth hormone (Gh) and prolactin (Prl) in the adult gland. Inhibition of the pathway by cyclopamine reversed these effects indicating that active Hh signaling positively regulates proliferative processes of adult pituitary stem cells and hormone production in the anterior pituitary. Since hormone producing cells of the adenohypophysis as well as ACTH-, GH- and PRL-immunopositive adenomas express SHH and its target GLI1, we furthermore propose that excess HH signaling is involved in the development/maintenance of hormone-producing pituitary adenomas. These findings advance the understanding of physiological hormone regulation and may open new treatment options for pituitary tumors. PMID:27109116

  10. New insights on the role of luteinizing hormone releasing hormone agonists in premenopausal early breast cancer patients.

    PubMed

    Del Mastro, Lucia; Rossi, Giovanni; Lambertini, Matteo; Poggio, Francesca; Pronzato, Paolo

    2016-01-01

    Luteinising hormone releasing hormone agonists (LH-RHa) are effective in the treatment of advanced endocrine-sensitive breast cancer in premenopausal patients, but their role in the adjuvant setting has remained controversial for a long time. Tamoxifen for 5 years has been traditionally considered the standard endocrine therapy for premenopausal patients and this is still valid for many patients. However, the recently reported SOFT trial has suggested that adding ovarian function suppression (OFS) to tamoxifen could improve DFS in women at sufficient risk to warrant adjuvant chemotherapy and who remained premenopausal after this therapy. The administration of an aromatase inhibitor plus OFS represents an additional therapeutic option for hormone-receptor positive premenopausal breast cancer patients, according to the combined analysis of the SOFT and TEXT trials. Temporary ovarian suppression induced by LH-RHa has been recognized as an effective strategy to preserve ovarian function from the toxic effects of chemotherapy and is now recommended in young breast cancer patients with endocrine-insensitive tumors. In this review, we discuss recent data on the role of LH-RHa in combination with tamoxifen or with an aromatase inhibitor, and we comment on its role as a strategy to preserve ovarian function in young patients candidates for adjuvant or neo-adjuvant chemotherapy. PMID:26613834

  11. Aging influences steroid hormone release by mink ovaries and their response to leptin and IGF-I

    PubMed Central

    Sirotkin, Alexander V.; Mertin, Dušan; Süvegová, Karin; Harrath, Abdel Halim; Kotwica, Jan

    2016-01-01

    ABSTRACT The aim of our study was to understand whether ovarian steroid hormones, and their response to the metabolic hormones leptin and IGF-I leptin, could be involved in the control of mink reproductive aging via changes in basal release of ovarian progesterone and estradiol. For this purpose, we compared the release of progesterone and estradiol by ovarian fragments isolated from young (yearlings) and old (3-5 years of age) minks cultured with and without leptin and IGF-I (0, 1, 10 or 100 ng/ml). We observed that isolated ovaries of older animals produced less progesterone but not less estradiol than the ovaries of young animals. Leptin addition stimulated estradiol release by the ovarian tissue of young animals but inhibited it in older females. Leptin did not influence progesterone output by the ovaries of either young or older animals. IGF-I inhibited estradiol output in young but not old animals, whereas progesterone release was inhibited by IGF-I irrespective of the animal age. Our observations demonstrate the involvement of both leptin and IGF-I in the control of mink ovarian steroid hormones release. Furthermore, our findings suggest that reproductive aging in minks can be due to (a) reduction in basal progesterone release and (b) alterations in the response of estradiol but not of progesterone to leptin and IGF-I. PMID:26794607

  12. Inhibition of progesterone secretion during the luteal phase by two luteinizing hormone-releasing hormone agonists in Macaca fascicularis.

    PubMed

    Raynaud, J P; Mary, I; Moguilewsky, M; Mouren, M; Labrie, F

    1980-12-01

    The administration of 200 microgram of the potent luteinizing hormone-releasing hormone (LHRH) agonist [D-Leu6,des-Gly-NH2(10)]LHRH ethylamide on day 6 following the plasma estradiol peak to 11 female monkeys (Macaca fascicularis) during two consecutive menstrual cycles decreased plasma progesterone levels by 40.0% +/- 3.9% as compared with previous control cycles. The plasma estradiol profile and the cycle length were not affected significantly by the treatment. Similar results were obtained with 25 microgram of [D-Ser(TBU)6,des-Gly-NH2(10)]LHRH ethylamide administered to one monkey at the same period of the cycle, such treatment leading to a 41% inhibition of circulating progesterone levels. Although plasma progesterone levels were still reduced in the two post-treatment cycles in monkeys treated with the high dose (200 microgram) of [D-Leu6,des-Gly-NH2(10)]LHRH ethylamide, the recovery cycle was normal after the administration of a lower dose (25 microgram) of [D-Ser(TBU)6, des-Gly-NH2(10)] LHRH ethylamide. The M. fascicularis monkey thus appears as a valid model with which to study the inhibitory effects of LHRH agonists on luteal function. PMID:6778718

  13. Is radiation-induced ovarian failure in rhesus monkeys preventable by luteinizing hormone-releasing hormone agonists?: Preliminary observations

    SciTech Connect

    Ataya, K.; Pydyn, E.; Ramahi-Ataya

    1995-03-01

    With the advent of cancer therapy, increasing numbers of cancer patients are achieving long term survival. Impaired ovarian function after radiation therapy has been reported in several studies. Some investigators have suggested that luteinizing hormone-releasing hormone agonists (LHRHa) can prevent radiation-induced ovarian injury in rodents. Adult female rhesus monkeys were given either vehicle or Leuprolide acetate before, during, and after radiation. Radiation was given in a dose of 200 rads/day for a total of 4000 rads to the ovaries. Frequent serum samples were assayed for estradiol (E{sub 2}) and FSH. Ovariectomy was performed later. Ovaries were processed and serially sectioned. Follicle count and size distribution were determined. Shortly after radiation started, E{sub 2} dropped to low levels, at which it remained, whereas serum FSH level, which was low before radiation, rose soon after starting radiation. In monkeys treated with a combination of LHRHa and radiation, FSH started rising soon after the LHRHa-loaded minipump was removed (after the end of radiation). Serum E{sub 2} increased after the end of LHRHa treatment in the non-irradiated monkey, but not in the irradiated monkey. Follicle counts were not preserved in the LHRHa-treated monkeys that received radiation. The data demonstrated no protective effect of LHRHa treatment against radiation-induced ovarian injury in this rhesus monkey model. 58 refs., 2 figs., 1 tab.

  14. Growth hormone-releasing hormone resistance in pseudohypoparathyroidism type ia: new evidence for imprinting of the Gs alpha gene.

    PubMed

    Mantovani, Giovanna; Maghnie, Mohamad; Weber, Giovanna; De Menis, Ernesto; Brunelli, Valeria; Cappa, Marco; Loli, Paola; Beck-Peccoz, Paolo; Spada, Anna

    2003-09-01

    Heterozygous inactivating mutations in the Gs alpha gene cause Albright's hereditary osteodystrophy. Consistent with the observation that only maternally inherited mutations lead to resistance to hormone action [pseudohypoparathyroidism type Ia (PHP Ia)], recent studies provided evidence for a predominant maternal origin of Gs alpha transcripts in endocrine organs, such as thyroid, gonad, and pituitary. The aim of this study was to investigate the presence of pituitary resistance to hypothalamic hormones acting via Gs alpha-coupled receptors in patients with PHP Ia. Six of nine patients showed an impaired GH responsiveness to GHRH plus arginine, consistent with a complete GH deficiency (GH peak from 2.6-8.6 microg/liter, normal > 16.5), and partial (GH peak 13.9 and 13.6 microg/liter) and normal responses were found in two and one patient, respectively. Accordingly, IGF-I levels were below and in the low-normal range in seven and two patients. All patients had a normal cortisol response to 1 microg ACTH test, suggesting a normal corticotroph function that was confirmed by a normal ACTH and cortisol response to CRH test in three patients. In conclusion, we report that in addition to PTH and TSH resistance, patients with PHP Ia display variable degrees of GHRH resistance, consistent with Gs alpha imprinting in human pituitary. PMID:12970263

  15. Neither bST nor Growth Hormone Releasing Factor Alter Expression of Thyroid Hormone Receptors in Liver and Mammary Tissues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Physiological effects of thyroid hormones are mediated primarily by binding of triiodothyronine, to specific nuclear receptors. It has been hypothesized that organ-specific changes in production of triiodothyronine from its prohormone, thyroxine, target the action of thyroid hormones to the mammary...

  16. Apparent involvement of opioid peptides in stress-induced enhancement of tumor growth.

    PubMed

    Lewis, J W; Shavit, Y; Terman, G W; Nelson, L R; Gale, R P; Liebeskind, J C

    1983-01-01

    Exposure to stress has been associated with alterations in both immune function and tumor development in man and laboratory animals. In the present study, we investigated the effect of a particular type of inescapable footshock stress, known to cause an opioid mediated form of analgesia, on survival time of female Fischer 344 rats injected with a mammary ascites tumor. Rats subjected to inescapable footshock manifested an enhanced tumor growth indicated by a decreased survival time and decreased percent survival. This tumor enhancing effect of stress was prevented by the opiate antagonist, naltrexone, suggesting a role for endogenous opioid peptides in this process. In the absence of stress, naltrexone did not affect tumor growth. PMID:6686324

  17. Circadian and sleep-dependent regulation of hormone release in humans

    NASA Technical Reports Server (NTRS)

    Czeisler, C. A.; Klerman, E. B.

    1999-01-01

    Daily oscillations characterize the release of nearly every hormone. The circadian pacemaker, located in the suprachiasmatic nucleus of the hypothalamus, generates circadian, approximately 24-hour rhythms in many physiologic functions. However, the observed hormonal oscillations do not simply reflect the output of this internal clock. Instead, daily hormonal profiles are the product of a complex interaction between the output of the circadian pacemaker, periodic changes in behavior, light exposure, neuroendocrine feedback mechanisms, gender, age, and the timing of sleep and wakefulness. The interaction of these factors can affect hormonal secretory pulse frequency and amplitude, with each endocrine system differentially affected by these factors. This chapter examines recent advances in understanding the effects on endocrine rhythms of a number of these factors. Sleep exerts a profound effect on endocrine secretion. Sleep is a dynamic process that is characterized by periodic changes in electrophysiologic activity. These electrophysiologic changes, which are used to mark the state and depth of sleep, are associated with periodic, short-term variations in hormonal levels. The secretion of hormones such as renin and human growth hormone are strongly influenced by sleep or wake state, while melatonin and cortisol levels are relatively unaffected by sleep or wake state. In addition, sleep is associated with changes in posture, behavior, and light exposure, each of which is known to affect endocrine secretion. Furthermore, the tight concordance of habitual sleep and wake times with certain circadian phases has made it difficult to distinguish sleep and circadian effects on these hormones. Specific protocols, designed to extract circadian and sleep information semi-independently, have been developed and have yielded important insights into the effects of these regulatory processes. These results may help to account for changes in endocrine rhythms observed in circadian

  18. The FGF-2-Derived Peptide FREG Inhibits Melanoma Growth In Vitro and In Vivo

    PubMed Central

    Aguzzi, Maria S; Faraone, Debora; D'Arcangelo, Daniela; De Marchis, Francesco; Toietta, Gabriele; Ribatti, Domenico; Parazzoli, Alberto; Colombo, Paolo; Capogrossi, Maurizio C; Facchiano, Antonio

    2011-01-01

    Previous data report that fibroblast growth factor-2 (FGF-2)-derived peptide FREG potently inhibits FGF-2-dependent angiogenesis in vitro and in vivo. Here, we show that FREG inhibits up to 70% in vitro growth and invasion/migration of smooth muscle and melanoma cells. Such inhibition is mediated by platelet-derived growth factor-receptor-α (PDGF-Rα); in fact, proliferation and migration were restored upon PDGF-Rα neutralization. Further experiments demonstrated that FREG interacts with PDGF-Rα both in vitro and in vivo and stimulates its phosphorylation. We have previously shown that overexpressing PDGF-Rα strongly inhibits melanoma growth in vivo; we, therefore, hypothesized that PDGF-Rα agonists may represent a novel tool to inhibit melanoma growth in vivo. To support this hypothesis, FREG was inoculated intravenously (i.v.) in a mouse melanoma model and markedly inhibited pulmonary metastases formation. Immunohistochemical analyses showed less proliferation, less angiogenesis, and more apoptosis in metastasized lungs upon FREG treatment, as compared to untreated controls. Finally, in preliminary acute toxicity studies, FREG showed no toxicity signs in healthy animals, and neither microscopic nor macroscopic toxicity at the liver, kidney, and lungs level. Altogether, these data indicate that FREG systemic treatment strongly inhibits melanoma metastases development and indicate for the first time that agonists of PDGF-Rα may control melanoma both in vitro and in vivo. PMID:20924364

  19. Peptide-modified Substrate for Modulating Gland Tissue Growth and Morphology In Vitro

    PubMed Central

    Taketa, Hiroaki; Sathi, Gulsan Ara; Farahat, Mahmoud; Rahman, Kazi Anisur; Sakai, Takayoshi; Hirano, Yoshiaki; Kuboki, Takuo; Torii, Yasuhiro; Matsumoto, Takuya

    2015-01-01

    In vitro fabricated biological tissue would be a valuable tool to screen newly synthesized drugs or understand the tissue development process. Several studies have attempted to fabricate biological tissue in vitro. However, controlling the growth and morphology of the fabricated tissue remains a challenge. Therefore, new techniques are required to modulate tissue growth. RGD (arginine-glycine-aspartic acid), which is an integrin-binding domain of fibronectin, has been found to enhance cell adhesion and survival; it has been used to modify substrates for in vitro cell culture studies or used as tissue engineering scaffolds. In addition, this study shows novel functions of the RGD peptide, which enhances tissue growth and modulates tissue morphology in vitro. When an isolated submandibular gland (SMG) was cultured on an RGD-modified alginate hydrogel sheet, SMG growth including bud expansion and cleft formation was dramatically enhanced. Furthermore, we prepared small RGD-modified alginate beads and placed them on the growing SMG tissue. These RGD-modified beads successfully induced cleft formation at the bead position, guiding the desired SMG morphology. Thus, this RGD-modified material might be a promising tool to modulate tissue growth and morphology in vitro for biological tissue fabrication. PMID:26098225

  20. Beta hairpin peptide hydrogels as an injectable solid vehicle for neurotrophic growth factor delivery

    PubMed Central

    Lindsey, Stephan; Piatt, Joseph H.; Worthington, Peter; Sönmez, Cem; Satheye, Sameer; Schneider, Joel P.; Pochan, Darrin J.; Langhans, Sigrid A.

    2016-01-01

    There is intense interest in developing novel methods for the sustained delivery of low levels of clinical therapeutics. MAX8 is a peptide-based beta-hairpin hydrogel that has unique shear thinning properties that allow for immediate rehealing after the removal of shear forces, making MAX8 an excellent candidate for injectable drug delivery at a localized injury site. The current studies examined the feasibility of using MAX8 as a delivery system for Nerve Growth Factor (NGF) and Brain-derived neurotrophic factor (BDNF), two neurotrophic growth factors currently used in experimental treatments of spinal cord injuries. Experiments determined that encapsulation of NGF and BDNF within MAX8 did not negatively impact gel formation or rehealing and that shear thinning did not result in immediate growth factor release. We found that increased NGF/BDNF dosages increased the amount and rate of growth factor release and that NGF/BDNF release was inversely related to the concentration of MAX8, indicating that growth factor release can be tuned by adjusting MAX8 concentrations. Encapsulation within MAX8 protected NGF and BDNF from in vitro degradation for up to 28 days. Released NGF resulted in the formation of neurite-like extensions in PC12 pheochromocytoma cells, demonstrating that NGF remains biologically active after release from encapsulation. Direct physical contact of PC12 cells with NGF-containing hydrogel did not inhibit neurite-like extension formation. On a molecular level, encapsulated growth factors activated the NGF/BDNF signaling pathways. Taken together, our data show MAX8 acts as a time-release gel, continually releasing low levels of growth factor over 21 days. MAX8 allows for greater dosage control and sustained therapeutic growth factor delivery, potentially alleviating side effects and improving the efficacy of current therapies. PMID:26225909

  1. Combination of long-acting microcapsules of the D-tryptophan-6 analog of luteinizing hormone-releasing hormone with chemotherapy: investigation in the rat prostate cancer model.

    PubMed Central

    Schally, A V; Redding, T W

    1985-01-01

    The effect of combining hormonal treatment consisting of long-acting microcapsules of the agonist [D-Trp6]LH-RH (the D-tryptophan-6 analog of luteinizing hormone-releasing hormone) with the chemotherapeutic agent cyclophosphamide was investigated in the Dunning R-3327H rat prostate cancer model. Microcapsules of [D-Trp6]LH-RH formulated from poly(DL-lactide-co-glycolide) and calculated to release a controlled dose of 25 micrograms/day were injected intramuscularly once a month. Cyclophosphamide (Cytoxan) (5 mg/kg of body weight) was injected intraperitoneally twice a week. When the therapy was started 90 days after tumor transplantation--at the time that the cancers were well developed-and was continued for 2 months, tumor volume was significantly reduced by the microcapsules or Cytoxan given alone. The combination of these two agents similarly inhibited tumor growth but did not show a synergistic effect. In another study, the treatment was started 2 months after transplantation, when the developing tumors measured 60-70 mm3. Throughout the treatment period of 100 days, the microcapsules of [D-Trp6]LH-RH reduced tumor volume more than Cytoxan did, and the combination of the two drugs appeared to completely arrest tumor growth. Tumor weights also were diminished significantly in all experimental groups, the decrease in weight being smaller in the Cytoxan-treated group than in rats that received the microcapsules. The combination of Cytoxan plus the microcapsules was 10-100 times more effective than the single agents in reducing tumor weights. In both experiments, testes and ventral prostate weights were significantly diminished, serum testosterone was suppressed to undetectable levels, and prolactin values were reduced by administration of microcapsules of [D-Trp6]LH-RH alone or in combination with Cytoxan. These results in rats suggest that combined administration of long acting microcapsules of [D-Trp6]LH-RH with a chemotherapeutic agent, started soon after the

  2. Multi-species sequence comparison reveals conservation of ghrelin gene-derived splice variants encoding a truncated ghrelin peptide.

    PubMed

    Seim, Inge; Jeffery, Penny L; Thomas, Patrick B; Walpole, Carina M; Maugham, Michelle; Fung, Jenny N T; Yap, Pei-Yi; O'Keeffe, Angela J; Lai, John; Whiteside, Eliza J; Herington, Adrian C; Chopin, Lisa K

    2016-06-01

    The peptide hormone ghrelin is a potent orexigen produced predominantly in the stomach. It has a number of other biological actions, including roles in appetite stimulation, energy balance, the stimulation of growth hormone release and the regulation of cell proliferation. Recently, several ghrelin gene splice variants have been described. Here, we attempted to identify conserved alternative splicing of the ghrelin gene by cross-species sequence comparisons. We identified a novel human exon 2-deleted variant and provide preliminary evidence that this splice variant and in1-ghrelin encode a C-terminally truncated form of the ghrelin peptide, termed minighrelin. These variants are expressed in humans and mice, demonstrating conservation of alternative splicing spanning 90 million years. Minighrelin appears to have similar actions to full-length ghrelin, as treatment with exogenous minighrelin peptide stimulates appetite and feeding in mice. Forced expression of the exon 2-deleted preproghrelin variant mirrors the effect of the canonical preproghrelin, stimulating cell proliferation and migration in the PC3 prostate cancer cell line. This is the first study to characterise an exon 2-deleted preproghrelin variant and to demonstrate sequence conservation of ghrelin gene-derived splice variants that encode a truncated ghrelin peptide. This adds further impetus for studies into the alternative splicing of the ghrelin gene and the function of novel ghrelin peptides in vertebrates. PMID:26792793

  3. Walker 256 Tumor Growth Suppression by Crotoxin Involves Formyl Peptide Receptors and Lipoxin A4.

    PubMed

    Brigatte, Patrícia; Faiad, Odair Jorge; Ferreira Nocelli, Roberta Cornélio; Landgraf, Richardt G; Palma, Mario Sergio; Cury, Yara; Curi, Rui; Sampaio, Sandra Coccuzzo

    2016-01-01

    We investigated the effects of Crotoxin (CTX), the main toxin of South American rattlesnake (Crotalus durissus terrificus) venom, on Walker 256 tumor growth, the pain symptoms associated (hyperalgesia and allodynia), and participation of endogenous lipoxin A4. Treatment with CTX (s.c.), daily, for 5 days reduced tumor growth at the 5th day after injection of Walker 256 carcinoma cells into the plantar surface of adult rat hind paw. This observation was associated with inhibition of new blood vessel formation and decrease in blood vessel diameter. The treatment with CTX raised plasma concentrations of lipoxin A4 and its natural analogue 15-epi-LXA4, an effect mediated by formyl peptide receptors (FPRs). In fact, the treatment with Boc-2, an inhibitor of FPRs, abolished the increase in plasma levels of these mediators triggered by CTX. The blockage of these receptors also abolished the inhibitory action of CTX on tumor growth and blood vessel formation and the decrease in blood vessel diameter. Together, the results herein presented demonstrate that CTX increases plasma concentrations of lipoxin A4 and 15-epi-LXA4, which might inhibit both tumor growth and formation of new vessels via FPRs. PMID:27190493

  4. Walker 256 Tumor Growth Suppression by Crotoxin Involves Formyl Peptide Receptors and Lipoxin A4

    PubMed Central

    Brigatte, Patrícia; Faiad, Odair Jorge; Ferreira Nocelli, Roberta Cornélio; Landgraf, Richardt G.; Palma, Mario Sergio; Cury, Yara; Curi, Rui; Sampaio, Sandra Coccuzzo

    2016-01-01

    We investigated the effects of Crotoxin (CTX), the main toxin of South American rattlesnake (Crotalus durissus terrificus) venom, on Walker 256 tumor growth, the pain symptoms associated (hyperalgesia and allodynia), and participation of endogenous lipoxin A4. Treatment with CTX (s.c.), daily, for 5 days reduced tumor growth at the 5th day after injection of Walker 256 carcinoma cells into the plantar surface of adult rat hind paw. This observation was associated with inhibition of new blood vessel formation and decrease in blood vessel diameter. The treatment with CTX raised plasma concentrations of lipoxin A4 and its natural analogue 15-epi-LXA4, an effect mediated by formyl peptide receptors (FPRs). In fact, the treatment with Boc-2, an inhibitor of FPRs, abolished the increase in plasma levels of these mediators triggered by CTX. The blockage of these receptors also abolished the inhibitory action of CTX on tumor growth and blood vessel formation and the decrease in blood vessel diameter. Together, the results herein presented demonstrate that CTX increases plasma concentrations of lipoxin A4 and 15-epi-LXA4, which might inhibit both tumor growth and formation of new vessels via FPRs. PMID:27190493

  5. PbSe nanocrystal growth as nanocubes and nanorods on peptide nanotubes via different directed-assembly pathways

    NASA Astrophysics Data System (ADS)

    Shi, Menglu; Su, Wei; Matsui, Hiroshi

    2010-11-01

    Pb-binding TAR-1 peptides (Ile-Ser-Leu-Leu-His-Ser-Thr) were covalently conjugated on a bolaamphiphile peptide nanotube substrate and the precursors of PbSe were incubated at room temperature. This resulted in the growth of highly crystalline PbSe nanocubes on this biomimetic cylindrical substrate. The growth mechanism to generate nanocubes occurs via the directed self-assembly of nanoparticles and then nanoparticle fusion. The peptide conformation and the cylindrical peptide nanotube substrate play important roles in the mesoscopic crystallization of PbSe nanocubes. Changing the buffer for the peptide immobilization process from 2-(N-morpholino)ethanesulfonic acid to phosphate induces a transformation in the nanocrystal shape from nanocube to nanorods. The conformational change of the TAR-1 peptide on the nanotubes due to the change in the buffer seems to be responsible for aggregating intermediate nanoparticles in different directions for the directed fusion and mesoscopic crystallization of PbSe into the different shapes.

  6. PbSe nanocrystal growth as nanocubes and nanorods on peptide nanotubes via different directed-assembly pathways.

    PubMed

    Shi, Menglu; Su, Wei; Matsui, Hiroshi

    2010-11-01

    Pb-binding TAR-1 peptides (Ile-Ser-Leu-Leu-His-Ser-Thr) were covalently conjugated on a bolaamphiphile peptide nanotube substrate and the precursors of PbSe were incubated at room temperature. This resulted in the growth of highly crystalline PbSe nanocubes on this biomimetic cylindrical substrate. The growth mechanism to generate nanocubes occurs via the directed self-assembly of nanoparticles and then nanoparticle fusion. The peptide conformation and the cylindrical peptide nanotube substrate play important roles in the mesoscopic crystallization of PbSe nanocubes. Changing the buffer for the peptide immobilization process from 2-(N-morpholino)ethanesulfonic acid to phosphate induces a transformation in the nanocrystal shape from nanocube to nanorods. The conformational change of the TAR-1 peptide on the nanotubes due to the change in the buffer seems to be responsible for aggregating intermediate nanoparticles in different directions for the directed fusion and mesoscopic crystallization of PbSe into the different shapes. PMID:20835484

  7. Luteinizing hormone-releasing hormone (LH-RH) as a diagnostic and research tool in gynecologic endocrinology.

    PubMed

    Taymor, M L; Thompson, I E; Berger, M J; Patton, W

    1974-11-15

    A study is reported on the effects of 150 mcg. of luteinizing hormone-releasing hormone (LH-RH), administered iv to 48 women with 5 types of secondary oligoamenorrhea, on the serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) Levels. At Time 0, patients with pituitary disease showed a markedly diminished LH response and patients with polycystic ovarian disease with enlarged ovaries showed a brisk, elevated LH response. FSH levels in patients with pituitary disease and polycystic ovarian disease showed a negligible rise at Time 0. 9 of 10 patients with pituitary disease and 5 of 9 patients with dietary amenorrhea had a low LH response 30 minutes after LH-RH administration. FSH response 60 minutes after injection in patients with pituitary disease and polycystic ovarian disease seemed to be lowered though too much overlap prevented a complete diagnosis. The conclusion of this initial study is that through baseline determinations of FSH and LH, along with a LH-RH stimulation test, useful data are provided for determining whether amenorrhea is due to ovarian or pituitary failure. A 2nd study evaluated the effects of 150 mcg of LH-RH administered iv before and after the im administration of various dosages of estrogen and progesterone to anovulatory women. A vigorous response in pituitary gonadotropin, particularly LH, was observed with LH-RH administered only. The effect with estrogen and progesterone was diminished pituitary response in terms of LH production. It is concluded that estrogen and progesterone exert a negative feedback effect on gonadotropin secretion at the hypothalamic and pituitary levels. PMID:4611213

  8. Ability of luteinizing hormone releasing hormone-Pseudomonas aeruginosa exotoxin 40 binding to LHRH receptor on human liver cancer cells

    PubMed Central

    Gong, Shou-Liang; Zhao, Gang; Zhao, Hong-Guang; Lü, Wen-Tian; Liu, Guang-Wei; Zhu, Ping

    2004-01-01

    AIM: To explore the ability of recombinant toxin luteinizing hormone releasing hormone-Pseudomonas aeruginosa exotoxin 40 (LHRH-PE40) and LHRH binding to LHRH receptor (LHRHR) on the membrane surface of human liver cancer HEPG cells. METHODS: LHRH was labeled by using 125I with enzymatic reaction. The affinity and receptor volume of LHRH-PE40 and LHRH binding to LHRHR on the membrane surface of human liver cancer cells were measured with radioligand receptor assay. RESULTS: The specific activity of LHRH labeled with 125I was 2.7 × 104 kBq/μL, and its radiochemical purity reached to 99.2%-99.7%. The binding of 125I to LHRH was maximal for 240 min in the warm cultivation, and this binding was stabilized. The inhibiting rates of 125I-LHRH and LHRH on the proliferation of human liver cancer HEPG cells were not significantly different. On the basis of the saturation curve of 125I-LHRH binding to the membrane LHRHR of HEPG cells, 125I-LHRH of 1 × 105 cpm was selected for radioligand receptor assay. The affinity constants (Kd) of LHRH-PE40 and LHRH binding to the membrane LHRHR of HEPG cells were 0.43 ± 0.12 nmol/L and 4.86 ± 1.47 nmol/L, respectively, and their receptor volumes were 0.37 ± 0.15 μmol/g and 0.42 ± 0.13 μmol/g, respectively. The binding of LHRH-PE40 to the membrane protein of normal liver cells was not observed. CONCLUSION: The recombinant toxin LHRH-PE40 binding to the membrane surface of LHRHR of human liver cancer HEPG cells was very strong, while the specific binding of it to normal liver cells was not observed. The results provide an important experimental basis for the clinical application of LHRH-PE. PMID:15334689

  9. La Crosse virus (LACV) Gc fusion peptide mutants have impaired growth and fusion phenotypes, but remain neurotoxic

    SciTech Connect

    Soldan, Samantha S.; Hollidge, Bradley S.; Wagner, Valentina; Weber, Friedemann; Gonzalez-Scarano, Francisco

    2010-09-01

    La Crosse virus is a leading cause of pediatric encephalitis in the Midwestern United States and an emerging pathogen in the American South. The LACV glycoprotein Gc plays a critical role in entry as the virus attachment protein. A 22 amino acid hydrophobic region within Gc (1066-1087) was recently identified as the LACV fusion peptide. To further define the role of Gc (1066-1087) in virus entry, fusion, and neuropathogenesis, a panel of recombinant LACV (rLACV) fusion peptide mutant viruses was generated. Replication of mutant rLACVs was significantly reduced. In addition, the fusion peptide mutants demonstrated decreased fusion phenotypes relative to LACV-WT. Interestingly, these viruses maintained their ability to cause neuronal loss in culture, suggesting that the fusion peptide of LACV Gc is a determinant of properties associated with neuroinvasion (growth to high titer in muscle cells and a robust fusion phenotype), but not necessarily of neurovirulence.

  10. Patterning nanofibrils through the templated growth of multiple modified amyloid peptides.

    PubMed

    Sakai, Hiroki; Watanabe, Ken; Kudoh, Fuki; Kamada, Rui; Chuman, Yoshiro; Sakaguchi, Kazuyasu

    2016-01-01

    There has been considerable interest in the patterning of functionalized nanowires because of the potential applications of these materials to the construction of nanodevices. A variety of biomolecular building blocks containing amyloid peptides have been used to functionalize nanowires. However, the patterning of self-assembled nanowires can be challenging because of the difficulties associated with controlling the self-assembly of these functionalized building blocks. Herein, we present a versatile approach for the patterning of nanowires based on the combination of templated fibril growth with a versatile functionalization method using our structure-controllable amyloid peptides (SCAPs). Using this approach, we have succeeded in the formation of multi-type nanowires with tandem domain structures in high yields. Given that the mixing-SCAP method can lead to the formation of tandem fibrils, it is noteworthy that our method allowed us to control the initiation of fibril formation from the gold nanoparticles, which were attached to a short fibril as initiation points. This approach could be used to prepare a wide variety of fibril patterns, and therefore holds great potential for the development of novel self-assembled nanodevices. PMID:27559011

  11. Patterning nanofibrils through the templated growth of multiple modified amyloid peptides

    PubMed Central

    Sakai, Hiroki; Watanabe, Ken; Kudoh, Fuki; Kamada, Rui; Chuman, Yoshiro; Sakaguchi, Kazuyasu

    2016-01-01

    There has been considerable interest in the patterning of functionalized nanowires because of the potential applications of these materials to the construction of nanodevices. A variety of biomolecular building blocks containing amyloid peptides have been used to functionalize nanowires. However, the patterning of self-assembled nanowires can be challenging because of the difficulties associated with controlling the self-assembly of these functionalized building blocks. Herein, we present a versatile approach for the patterning of nanowires based on the combination of templated fibril growth with a versatile functionalization method using our structure-controllable amyloid peptides (SCAPs). Using this approach, we have succeeded in the formation of multi-type nanowires with tandem domain structures in high yields. Given that the mixing-SCAP method can lead to the formation of tandem fibrils, it is noteworthy that our method allowed us to control the initiation of fibril formation from the gold nanoparticles, which were attached to a short fibril as initiation points. This approach could be used to prepare a wide variety of fibril patterns, and therefore holds great potential for the development of novel self-assembled nanodevices. PMID:27559011

  12. Simultaneous Inhibition of Key Growth Pathways in Melanoma Cells and Tumor Regression by a Designed Bidentate Constrained Helical Peptide

    PubMed Central

    Dhar, Amlanjyoti; Mallick, Shampa; Ghosh, Piya; Maiti, Atanu; Ahmed, Israr; Bhattacharyya, Seemana; Mandal, Tapashi; Manna, Asit; Roy, Koushik; Singh, Sandeep; Nayak, Dipak Kumar; Wilder, Paul T.; Markowitz, Joseph; Weber, David J.; Ghosh, Mrinal K.; Chattopadhyay, Samit; Guha, Rajdeep; Konar, Aditya; Bandyopadhyay, Santu; Roy, Siddhartha

    2014-01-01

    Protein-protein interactions are part of a large number of signaling networks and potential targets for drug development. However, discovering molecules that can specifically inhibit such interactions is a major challenge. S100B, a calcium-regulated protein, plays a crucial role in the proliferation of melanoma cells through protein-protein interactions. In this article, we report the design and development of a bidentate conformationally constrained peptide against dimeric S100B based on a natural tight binding peptide, TRTK-12. The helical conformation of the peptide was constrained by substitution of α-amino isobutyric acid----an amino acid having high helical propensity----in positions which do not interact with S100B. A branched bidentate version of the peptide, bound to S100B tightly with a dissociation constant of 8 nM. When conjugated to a cell penetrating peptide, it caused growth inhibition and rapid apoptosis in melanoma cells. The molecule exerts anti-proliferative action through simultaneous inhibition of key growth pathways including reactivation of wild-type p53 and inhibition of Akt and STAT-3 phosphorylation. The apoptosis induced by the bidentate constrained helix is caused by direct migration of p53 to mitochondria. At moderate intravenous dose, the peptide completely inhibits melanoma growth in a mouse model without any significant observable toxicity. The specificity was shown by lack of ability of a double mutant peptide to cause tumor regression at the same dose level. The methodology described here for direct protein-protein interaction inhibition may be effective for rapid development of inhibitors against relatively weak protein-protein interactions for de novo drug development. PMID:24839139

  13. Vasoactive-intestinal-Peptide (vip) modulates the growth fraction of epithelial skin cells.

    PubMed

    Wollina, U; Bonnekoh, B; Mahrle, G

    1992-06-01

    Using the human keratinocyte cell line HaCaT, modifications of the growth fraction due to vasoactive intestinal peptide (VIP) were determined by immunostaining with monoclonal antibody Ki67. In addition, the expression of VIP receptor and epidermal growth factor (EGF) receptor have been analysed. VIP (10-(7) to 10-(11) M) produced an almost doubling of the total number of Ki67-positive cells in cultures with 2% fetal calf serum (FCS), wheras it was ineffective in FCS-free and 10% FCS cultures. The nuclear Ki67-staining patterns were classified into four categories. In FCS-free cultures VIP induced a shift from type III (light nucleus, staining nuclei) to type II (multiple, intensely stained spots). In cultures with 2% FCS, VIP induced a shift from type II to type III. VIP receptor expression was facilitated by VIP, when cells were grown in a medium supplemented with 10% FCS. VIP increased EGF receptor expression in FCS-free cultures but decreased the number EGF receptor-positive cells in experiments with 2% FCS. In conclusion, VIP is capable to modulate the growth fraction and receptor expression of HaCaT cells in vitro. The effects are dependent on the concentration of FCS within the culture medium. The findings might be of interest for keratinocyte pathology in general and dermatooncology in particular. PMID:21584504

  14. Controlling the Growth and Catalytic Activity of Platinum Nanoparticles Using Peptide and Polymer Ligands

    NASA Astrophysics Data System (ADS)

    Forbes, Lauren Marie

    Heterogeneous catalysts have widespread industrial applications. Platinum nanomaterials in particular, due to their particularly high electrocatalytic activity and durability, are used to catalyze a wide variety of reactions, including oxygen reduction, which is frequently used as the cathode reaction in fuel cells. As platinum is a very expensive material, a high priority in fuel cell research is the exploration of less expensive, more efficient catalysts for the oxygen reduction reaction (ORR). We demonstrate here the use of phage display to identify peptides that bind to Pt (100) which were then used to synthesize platinum cubes in solution. However, while the peptides were able to control particle growth, the bio-synthesized Pt particles showed extremely poor activity when tested for ORR. This could be attributed to peptide coverage on the surface or strong interactions between particular amino acids and the metal that are detrimental for catalysis. To investigate this further, we decided to investigate the role of individual amino acids on Pt nanocrystal synthesis and catalysis. For this, we conjugated the R-groups of single amino acids to polyethylene glycol (PEG) chains. Through this work we have determined that the identity of the amino acid R-group is important in both the synthesis and the catalytic activity of the particles. For Pt nanoparticle synthesis, we found that the hydrophobicity of the functional groups affected their ability to interact well with the particles during nucleation and growth, and thus only the hydrophilic functional groups were capable of mediating the synthesis to produce well-defined faceted particles. With respect to ORR, we found distinct trends that showed that the inclusion of certain amino acids could significantly enhance catalysis---even at high polymer loadings. This work presents evidence that counters the common conception that organic capping ligands decrease catalytic activity; in fact activity may actually be

  15. Effects of guar gum and cellulose on glucose absorption, hormonal release and hepatic metabolism in the pig

    NASA Technical Reports Server (NTRS)

    Nunes, C. S.; Malmlof, K.

    1992-01-01

    Six Large White pigs (mean body-weight 59 (SE 1.7) kg) were surgically fitted with permanent catheters in the portal vein, the brachiocephalic artery and the right hepatic vein, as well as with electromagnetic flow probes around the portal vein and the hepatic artery, and allowed to recover. The non-anaesthetized animals were given a basal non-fibre diet (diet A) alone or together with 60 g guar gum/kg (diet B) or 150 g purified cellulose/kg (diet C) by substitution for mica. The diets were given for weekly periods and according to a replicated 3 x 3 Latin square design. On the last day of each such adaptation period, test meals of 800 g were given before blood sampling. Sampling was continued for 8 h. Guar gum strongly reduced glucose apparent absorption without changing the absorption and the hepatic uptake profiles. Production rates of insulin, gastric inhibitory polypeptide and insulin-like growth factor-1 (IGF-1) were lowest after guar gum ingestion. However, the reductions in peripheral blood insulin levels caused by guar gum were not associated with a change in hepatic insulin extraction. IGF-1 appeared to be strongly secreted by the gut, whereas the liver had a net uptake of the peptide. Ingestion of guar gum increased the hepatic extraction coefficient of gut-produced IGF-1. Guar gum ingestion appeared also to decrease glucagon secretion. Cellulose at the level consumed had very few effects on the variables considered. It is suggested that the modulation of intestinal mechanisms by guar gum was sufficient to mediate the metabolic effects described.

  16. The glucagon-like peptide 2 pathway may mediate growth and development of the bovine gastrointestinal tract

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glucagon-like peptide 2 (GLP-2), secreted by enteroendocrine cells, has a number of physiological effects on the intestine of monogastric species, including promotion of growth of intestinal epithelium, reduction of epithelial cell apoptosis, and enhancement of intestinal blood flow, nutrient absorp...

  17. Stability of cytotoxic luteinizing hormone-releasing hormone conjugate (AN-152) containing doxorubicin 14-O-hemiglutarate in mouse and human serum in vitro: implications for the design of preclinical studies.

    PubMed

    Nagy, A; Plonowski, A; Schally, A V

    2000-01-18

    Recently, we developed a series of cytotoxic peptide conjugates containing 14-O-glutaryl esters of doxorubicin (DOX) or 2-pyrrolino-DOX (AN-201). Serum carboxylesterase enzymes (CE) can partially hydrolyze these conjugates in the circulation, releasing the cytotoxic radical, before the targeting is complete. CE activity in serum of nude mice is about 10 times higher than in human serum. Thus, we found that the t(1/2) of AN-152, an analog of luteinizing hormone-releasing hormone (LH-RH) containing DOX, at 0.3 mg/ml is 19. 49 +/- 0.74 min in mouse serum and 126.06 +/- 3.03 min in human serum in vitro. The addition of a CE inhibitor, diisopropyl fluorophosphate (DFP), to mouse serum in vitro significantly (P < 0. 01) prolongs the t(1/2) of AN-152 to 69.63 +/- 4.44 min. When DFP is used in vivo, 400 nmol/kg cytotoxic somatostatin analog AN-238 containing AN-201 is well tolerated by mice, whereas all animals die after the same dose without DFP. In contrast, DFP has no effect on the tolerance of AN-201. A better tolerance to AN-238 after DFP treatment is due to the selective uptake of AN-238 by somatostatin receptor-positive tissues. Our results demonstrate that the suppression of the CE activity in nude mice greatly decreases the toxicity of cytotoxic hybrids containing 2-pyrrolino-DOX 14-O-hemiglutarate and brings this animal model closer to the conditions that exist in humans. The use of DFP together with these peptide conjugates in nude mice permits a better understanding of their mechanism of action and improves the clinical predictability of the oncological and toxicological results. PMID:10639165

  18. Efficient inhibition of tumor angiogenesis and growth by a synthetic peptide blocking S100A4-methionine aminopeptidase 2 interaction

    PubMed Central

    Ochiya, Takahiro; Takenaga, Keizo; Asagiri, Masataka; Nakano, Kazumi; Satoh, Hitoshi; Watanabe, Toshiki; Imajoh-Ohmi, Shinobu; Endo, Hideya

    2015-01-01

    The prometastatic calcium-binding protein, S100A4, is expressed in endothelial cells, and its downregulation markedly suppresses tumor angiogenesis in a xenograft cancer model. Given that endothelial S100A4 can be a molecular target for inhibiting tumor angiogenesis, we addressed here whether synthetic peptide capable of blocking S100A4-effector protein interaction could be a novel antiangiogenic agent. To examine this hypothesis, we focused on the S100A4-binding domain of methionine aminopeptidase 2, an effector protein, which plays a role in endothelial cell growth. Overexpression of the domain in mouse endothelial MSS31 cells reduced DNA synthesis, and the corresponding synthetic peptide (named NBD) indeed interacted with S100A4 and inhibited capillary formation in vitro and new blood vessel formation in vivo. Intriguingly, a single intra-tumor administration of the NBD peptide in human prostate cancer xenografts significantly reduced vascularity, resulting in tumor regression. Mechanistically, the NBD peptide enhanced assembly of nonmuscle myosin IIA filaments along with Ser1943 phosphorylation, stimulated formation of focal adhesions without phosphorylation of focal adhesion kinase, and provoked G1/S arrest of the cell cycle. Altogether, the NBD peptide is a potent inhibitor for tumor angiogenesis, and is the first example of an anticancer peptide drug developed on the basis of an endothelial S100A4-targeted strategy. PMID:26029719

  19. Efficient inhibition of tumor angiogenesis and growth by a synthetic peptide blocking S100A4-methionine aminopeptidase 2 interaction.

    PubMed

    Ochiya, Takahiro; Takenaga, Keizo; Asagiri, Masataka; Nakano, Kazumi; Satoh, Hitoshi; Watanabe, Toshiki; Imajoh-Ohmi, Shinobu; Endo, Hideya

    2015-01-01

    The prometastatic calcium-binding protein, S100A4, is expressed in endothelial cells, and its downregulation markedly suppresses tumor angiogenesis in a xenograft cancer model. Given that endothelial S100A4 can be a molecular target for inhibiting tumor angiogenesis, we addressed here whether synthetic peptide capable of blocking S100A4-effector protein interaction could be a novel antiangiogenic agent. To examine this hypothesis, we focused on the S100A4-binding domain of methionine aminopeptidase 2, an effector protein, which plays a role in endothelial cell growth. Overexpression of the domain in mouse endothelial MSS31 cells reduced DNA synthesis, and the corresponding synthetic peptide (named NBD) indeed interacted with S100A4 and inhibited capillary formation in vitro and new blood vessel formation in vivo. Intriguingly, a single intra-tumor administration of the NBD peptide in human prostate cancer xenografts significantly reduced vascularity, resulting in tumor regression. Mechanistically, the NBD peptide enhanced assembly of nonmuscle myosin IIA filaments along with Ser1943 phosphorylation, stimulated formation of focal adhesions without phosphorylation of focal adhesion kinase, and provoked G1/S arrest of the cell cycle. Altogether, the NBD peptide is a potent inhibitor for tumor angiogenesis, and is the first example of an anticancer peptide drug developed on the basis of an endothelial S100A4-targeted strategy. PMID:26029719

  20. Inhibiting bladder tumor growth with a cell penetrating R11 peptide derived from the p53 C-terminus.

    PubMed

    Zhang, Tingting; Wu, Kaijie; Ding, Chen; Sun, Kangwei; Guan, Zhenfeng; Wang, Xinyang; Hsieh, Jer-Tsong; He, Dalin; Fan, Jinhai

    2015-11-10

    Urothelial carcinoma of the bladder (UCB) is the most common malignancy of the urinary tract, nearly half of which contains a mutation in TP53 gene. Hence, therapeutic approach by restoring functional p53 protein in cancer cells will be beneficial. Recent studies have demonstrated the inhibition of cancer cell growth by p53 reactivation using a peptide derived from the p53 C-terminus (p53C). However, the outcome of reactivating p53 in controlling bladder cancer development is limited by its efficiency and specificity of peptide delivery, especially in metastatic animal models. Herein, we report that the cell penetrating peptide (polyarginine, R11)-conjugated p53C can exhibit a preferential uptake and growth inhibit of UCB cells expressing either mutant or wild-type TP53 by the activation of p53-dependent pathway. R11-p53C peptide treatment of preclinical orthotopic and metastatic bladder cancer models significantly decreased the tumor burden and increased the lifespan without a significant cytotoxicity. Based on these results, we believe that R11-p53C peptide has therapeutic potential for primary and metastatic bladder cancer, and R11-mediated transduction may be a useful strategy for the therapeutic delivery of large tumor suppressor molecules to tumor cells in vitro and in vivo. PMID:26462022

  1. Preparation and characterization of luteinising-hormone releasing hormone nanoliposomal microbubbles specifically targeting ovarian cancer cells in vitro.

    PubMed

    Zhang, Jinyi; Liu, Sisun; Zhu, Yuanfang; Zhang, Liping; Li, Wenjuan; Wang, Fen; Huang, Shuying

    2014-07-01

    The aim of the present study was to prepare luteinizing-hormone releasing hormone (LHRH) nanoliposomal microbubbles specifically targeting ovarian cancer cells. The lyophilization/sonication method was used to prepare non-targeting nanoliposomal microbubbles (N-N-Mbs). Using the biotin-avidin bridge method, conjugated LHRH antibodies to N-N-Mbs generated LHRH nanoliposomal microbubbles (LHRH-N-Mbs) specifically targeting ovarian cancer cells. The morphology and physicochemical properties of the microbubbles was detected using an optical microscope and zeta detector. The binding affinity between the secondary antibody and LHRH-N-Mbs or N-N-Mbs was determined by flow cytometry. The binding of LHRH-N-Mb to human ovarian cancer cells (OVCAR-3) was detected by light microscopy. The rounded and uniformly distributed N-N-Mbs and LHRH-N-Mbs were successfully generated. The particle size ranged from 295-468 nm with a mean of 360 nm for N-N-Mbs or 369-618 nm with a mean of 508 nm for LHRH-N-Mbs. There was a significant difference in size between the two groups (P<0.05), although the surface potential of the two microbubbles remained the same (-14.6 mV). Following being kept at room temperature for 14 days, no significant difference in the physicochemical properties of the LHRH-N-Mbs was detected compared with that of freshly prepared microbubbles. The secondary antibody binding rate of LHRH-N-Mbs and N-N-Mbs was 75.6 and 0.83%, respectively. Furthermore, the formation of a rosette-like structure surrounding OVCAR-3 cells was observed after the cells were incubated with LHRH-N-Mbs, whereas pre-incubation with LHRH antibody blocked this rosette formation. In conclusion, LHRH-N-Mbs specifically targeting ovarian cancer cells were successfully prepared through biotin-avidin mediation and the lyophilization/sonication method. The key feature of LHRH-N-Mbs is their small size, stability and high efficiency in targeting human OVCAR-3 cells in vitro. PMID:24805264

  2. Solution structures, dynamics, and ice growth inhibitory activity of peptide fragments derived from an antarctic yeast protein.

    PubMed

    Shah, Syed Hussinien H; Kar, Rajiv K; Asmawi, Azren A; Rahman, Mohd Basyaruddin A; Murad, Abdul Munir A; Mahadi, Nor M; Basri, Mahiran; Rahman, Raja Noor Zaliha A; Salleh, Abu B; Chatterjee, Subhrangsu; Tejo, Bimo A; Bhunia, Anirban

    2012-01-01

    Exotic functions of antifreeze proteins (AFP) and antifreeze glycopeptides (AFGP) have recently been attracted with much interest to develop them as commercial products. AFPs and AFGPs inhibit ice crystal growth by lowering the water freezing point without changing the water melting point. Our group isolated the Antarctic yeast Glaciozyma antarctica that expresses antifreeze protein to assist it in its survival mechanism at sub-zero temperatures. The protein is unique and novel, indicated by its low sequence homology compared to those of other AFPs. We explore the structure-function relationship of G. antarctica AFP using various approaches ranging from protein structure prediction, peptide design and antifreeze activity assays, nuclear magnetic resonance (NMR) studies and molecular dynamics simulation. The predicted secondary structure of G. antarctica AFP shows several α-helices, assumed to be responsible for its antifreeze activity. We designed several peptide fragments derived from the amino acid sequences of α-helical regions of the parent AFP and they also showed substantial antifreeze activities, below that of the original AFP. The relationship between peptide structure and activity was explored by NMR spectroscopy and molecular dynamics simulation. NMR results show that the antifreeze activity of the peptides correlates with their helicity and geometrical straightforwardness. Furthermore, molecular dynamics simulation also suggests that the activity of the designed peptides can be explained in terms of the structural rigidity/flexibility, i.e., the most active peptide demonstrates higher structural stability, lower flexibility than that of the other peptides with lower activities, and of lower rigidity. This report represents the first detailed report of downsizing a yeast AFP into its peptide fragments with measurable antifreeze activities. PMID:23209600

  3. Osteogenic growth peptide and its use as a bio-conjugate in regenerative medicine applications.

    PubMed

    Policastro, Gina M; Becker, Matthew L

    2016-05-01

    For nearly 2000 years, biomaterials have been used as damaged tissue implants. A field that started with wood and gold tissue replacements has evolved into an advanced science which combines ideas of cellular biology, engineering, and synthetic chemistry to produce bioresorbable materials capable of directing specific cell responses. With the overwhelming number of failed bone defect repairs every year, bone tissue engineering has become an important area of study. Both naturally occurring and synthetic polymeric materials have shown promising results for bone regeneration with their wide range of mechanical and degradation properties. Despite their favorable properties, these materials are limited by their lack of the biological cues necessary for enhanced bone formation and osteogenic differentiation. For this reason, naturally occurring growth factors, such as osteogenic growth peptide (OGP), have been studied for use in bone tissue engineering constructs to elicit more efficient bone healing. OGP functionalization of bioresorbable polymers has been shown to enhance regeneration of bone and osteogenic differentiation of stem cells in defect models. Vast improvements in bone tissue engineering constructs have been made possible through the use of OGP as a functional bio-conjugate. As this field continues to expand, the hopes of overcoming the limitations of current bone defect repair treatment methods is becoming a reality. WIREs Nanomed Nanobiotechnol 2016, 8:449-464. doi: 10.1002/wnan.1376 For further resources related to this article, please visit the WIREs website. PMID:26391307

  4. Purification of growth-promoting peptides and proteins, and of histones, by high pressure silica gel chromatography.

    PubMed

    Pickart, L R; Thaler, M M

    1975-01-01

    A rapid method for the purification of histones and a variety of growth-promoting proteins and peptides by chromatography on silica gel has been developed. The isolation of the growth-promoting components of serum has been hampered by excessive losses associated with the use of water-based purification mens in acidic methanol-H2O solutions (eg. insulin, albumin, the somatomedins) provides a basis for purification on high-pressure silica gel columns, while peptides and histones can be purified in similar solvents. After column chromatography, the solvent is removed by flash-evaporation, or the protein may be precipitated directly from the solvent by neutralization of the pH and the addition of ethanol. The retention of biological activity (eg. somatomedin-C binding to insulin receptors and cell-growth stimulation) and recovery are excellent. PMID:1215337

  5. A peptide derived from alpha-fetoprotein prevents the growth of estrogen-dependent human breast cancers sensitive and resistant to tamoxifen.

    PubMed

    Bennett, James A; Mesfin, Fassil B; Andersen, Thomas T; Gierthy, John F; Jacobson, Herbert I

    2002-02-19

    An 8-mer peptide (EMTOVNOG) derived from alpha-fetoprotein was compared with tamoxifen for activity against growth of human breast cancer xenografts implanted in immune-deficient mice. Both peptide and tamoxifen prevented growth of estrogen-receptor-positive MCF-7 and T47D human breast cancer xenografts. A subline of MCF-7, made resistant to tamoxifen by a 6-month exposure to this drug in culture, was found to be resistant to tamoxifen in vivo. Peptide completely prevented the xenograft growth of this tamoxifen-resistant subline of MCF-7. Neither peptide nor tamoxifen was effective in slowing the xenograft growth of the estrogen-receptor-negative MDA-MB-231 human breast cancer. A worrisome side effect of tamoxifen is its hypertrophic effect on the uterus. In this study, tamoxifen was shown to stimulate the growth of the immature mouse uterus in vivo, and the peptide significantly inhibited tamoxifen's uterotrophic effect. The mechanism of action of peptide is different from that of tamoxifen in that the peptide does not interfere with the binding of [(3)H]estradiol to the estrogen receptor. In conclusion, alpha-fetoprotein-derived peptide appears to be a novel agent that interferes with the growth of tamoxifen-sensitive as well as tamoxifen-resistant estrogen-receptor-positive human breast cancers; it inhibits the uterotrophic side effect of tamoxifen and, thus, it may be useful in combination with or in place of tamoxifen for treatment of estrogen-receptor-positive human breast cancers. PMID:11830647

  6. Imaging exocytosis of single glucagon-like peptide-1 containing granules in a murine enteroendocrine cell line with total internal reflection fluorescent microscopy

    SciTech Connect

    Ohara-Imaizumi, Mica; Aoyagi, Kyota; Akimoto, Yoshihiro; Nakamichi, Yoko; Nishiwaki, Chiyono; Kawakami, Hayato; Nagamatsu, Shinya

    2009-12-04

    To analyze the exocytosis of glucagon-like peptide-1 (GLP-1) granules, we imaged the motion of GLP-1 granules labeled with enhanced yellow fluorescent protein (Venus) fused to human growth hormone (hGH-Venus) in an enteroendocrine cell line, STC-1 cells, by total internal reflection fluorescent (TIRF) microscopy. We found glucose stimulation caused biphasic GLP-1 granule exocytosis: during the first phase, fusion events occurred from two types of granules (previously docked granules and newcomers), and thereafter continuous fusion was observed mostly from newcomers during the second phase. Closely similar to the insulin granule fusion from pancreatic {beta} cells, the regulated biphasic exocytosis from two types of granules may be a common mechanism in glucose-evoked hormone release from endocrine cells.

  7. Levels of hormones and cytokines associated with growth in Honamlı and native hair goats.

    PubMed

    Devrim, A K; Elmaz, O; Mamak, N; Sudagidan, M

    2015-01-01

    This study was designed to assess alterations of hormone and cytokine levels associated with growth period during puberty in Honamlı goats which were identified as a new goat breed and had one of the highest meat production potential among the other goat breeds in Turkey. Honamlı goats are originated from native hair goats, so parallel studies of sampling and analyzing were conducted also in native hair goats which have moderate meat production. Blood serum samples of Honamlı (n=90) and native hair goats (n=90) were obtained from the pure herds in Korkuteli and Ka districts of Anatolia. Concentrations of growth hormone (GH), myostatin (MSTN), insulin-like growth factor (IGF), growth hormone releasing hormone (GHRH), growth hormone releasing peptide (GHRP), leptin, transforming growth factor-betal (TGF-β1) and vascular endothelial cell growth factor (VEGF) levels were measured by ELISA in each breed in the age groups of 4, 8 and 12 months. The present results indicate interesting correlations among the age groups and all the examined hormone and cytokine parameters exhibited significant (P<0.05 and P<0.001) differences. The parameters investigated were usually begun to increase after 4 months of age in the both breeds and sexes. Therefore, this paper supported the view that the beginning of hormonal alterations of goats could occur at 4th month of age. The results reported here emphasize the primary role played by GH, MSTN, IGF-1, leptin, GHRH, GHRP, TGF-βi and VEGF in the first year growth period of goats. PMID:26172195

  8. Synthetic peptide derived from alpha-fetoprotein inhibits growth of human breast cancer: investigation of the pharmacophore and synthesis optimization.

    PubMed

    DeFreest, L A; Mesfin, F B; Joseph, L; McLeod, D J; Stallmer, A; Reddy, S; Balulad, S S; Jacobson, H I; Andersen, T T; Bennett, J A

    2004-05-01

    Asynthetic peptide that inhibits the growth of estrogen receptor positive (ER+) human breast cancers, growing as xenografts in mice, has been reported. The cyclic 9-mer peptide, cyclo[EMTOVNOGQ], is derived from alpha-fetoprotein (AFP), a safe, naturally occurring human protein produced during pregnancy, which itself has anti-estrogenic and anti-breast cancer activity. To determine the pharmacophore of the peptide, a series of analogs was prepared using solid-phase peptide synthesis. Analogs were screened in a 1-day bioassay, which assessed their ability to inhibit the estrogen-stimulated growth of uterus in immature mice. Deletion of glutamic acid, Glu1, abolished activity of the peptide, but glutamine (Gln) or asparagine (Asn) could be substituted for Glu1 without loss of activity. Methionine (Met2) was replaced with lysine (Lys) or tyrosine (Tyr) with retention of activity. Substitution of Lys for Met2 in the cyclic molecule resulted in a compound with activity comparable with the Met2-containing cyclic molecule, but with a greater than twofold increase in purity and corresponding increase in yield. This Lys analog demonstrated anti-breast cancer activity equivalent to that of the original Met-containing peptide. Therefore, Met2 is not essential for biologic activity and substitution of Lys is synthetically advantageous. Threonine (Thr3) is a nonessential site, and can be substituted with serine (Ser), valine (Val), or alanine (Ala) without significant loss of activity. Hydroxyproline (Hyp), substituted in place of the naturally occurring prolines (Pro4, Pro7), allowed retention of activity and increased stability of the peptide during storage. Replacement of the first Pro (Pro4) with Ser maintains the activity of the peptide, but substitution of Ser for the second Pro (Pro7) abolishes the activity of the peptide. This suggests that the imino acid at residue 7 is important for conformation of the peptide, and the backbone atoms are part of the pharmacophore, but

  9. Intracellular protein delivery activity of peptides derived from insulin-like growth factor binding proteins 3 and 5

    SciTech Connect

    Goda, Natsuko; Tenno, Takeshi; Inomata, Kosuke; Shirakawa, Masahiro; Tanaka, Toshiki; Hiroaki, Hidekazu

    2008-08-01

    Insulin-like growth factor binding proteins (IGFBPs) have various IGF-independent cellular activities, including receptor-independent cellular uptake followed by transcriptional regulation, although mechanisms of cellular entry remain unclear. Herein, we focused on their receptor-independent cellular entry mechanism in terms of protein transduction domain (PTD) activity, which is an emerging technique useful for clinical applications. The peptides of 18 amino acid residues derived from IGFBP-3 and IGFBP-5, which involve heparin-binding regions, mediated cellular delivery of an exogenous protein into NIH3T3 and HeLa cells. Relative protein delivery activities of IGFBP-3/5-derived peptides were approximately 20-150% compared to that of the HIV-Tat peptide, a potent PTD. Heparin inhibited the uptake of the fusion proteins with IGFBP-3 and IGFBP-5, indicating that the delivery pathway is heparin-dependent endocytosis, similar to that of HIV-Tat. The delivery of GST fused to HIV-Tat was competed by either IGFBP-3 or IGFBP-5-derived synthetic peptides. Therefore, the entry pathways of the three PTDs are shared. Our data has shown a new approach for designing protein delivery systems using IGFBP-3/5 derived peptides based on the molecular mechanisms of IGF-independent activities of IGFBPs.

  10. Neuroactive peptides as putative mediators of antiepileptic ketogenic diets.

    PubMed

    Giordano, Carmela; Marchiò, Maddalena; Timofeeva, Elena; Biagini, Giuseppe

    2014-01-01

    Various ketogenic diet (KD) therapies, including classic KD, medium chain triglyceride administration, low glycemic index treatment, and a modified Atkins diet, have been suggested as useful in patients affected by pharmacoresistant epilepsy. A common goal of these approaches is to achieve an adequate decrease in the plasma glucose level combined with ketogenesis, in order to mimic the metabolic state of fasting. Although several metabolic hypotheses have been advanced to explain the anticonvulsant effect of KDs, including changes in the plasma levels of ketone bodies, polyunsaturated fatty acids, and brain pH, direct modulation of neurotransmitter release, especially purinergic (i.e., adenosine) and γ-aminobutyric acidergic neurotransmission, was also postulated. Neuropeptides and peptide hormones are potent modulators of synaptic activity, and their levels are regulated by metabolic states. This is the case for neuroactive peptides such as neuropeptide Y, galanin, cholecystokinin, and peptide hormones such as leptin, adiponectin, and growth hormone-releasing peptides (GHRPs). In particular, the GHRP ghrelin and its related peptide des-acyl ghrelin are well-known controllers of energy homeostasis, food intake, and lipid metabolism. Notably, ghrelin has also been shown to regulate the neuronal excitability and epileptic activation of neuronal networks. Several lines of evidence suggest that GHRPs are upregulated in response to starvation and, particularly, in patients affected by anorexia and cachexia, all conditions in which also ketone bodies are upregulated. Moreover, starvation and anorexia nervosa are accompanied by changes in other peptide hormones such as adiponectin, which has received less attention. Adipocytokines such as adiponectin have also been involved in modulating epileptic activity. Thus, neuroactive peptides whose plasma levels and activity change in the presence of ketogenesis might be potential candidates for elucidating the neurohormonal

  11. Neuroactive Peptides as Putative Mediators of Antiepileptic Ketogenic Diets

    PubMed Central

    Giordano, Carmela; Marchiò, Maddalena; Timofeeva, Elena; Biagini, Giuseppe

    2014-01-01

    Various ketogenic diet (KD) therapies, including classic KD, medium chain triglyceride administration, low glycemic index treatment, and a modified Atkins diet, have been suggested as useful in patients affected by pharmacoresistant epilepsy. A common goal of these approaches is to achieve an adequate decrease in the plasma glucose level combined with ketogenesis, in order to mimic the metabolic state of fasting. Although several metabolic hypotheses have been advanced to explain the anticonvulsant effect of KDs, including changes in the plasma levels of ketone bodies, polyunsaturated fatty acids, and brain pH, direct modulation of neurotransmitter release, especially purinergic (i.e., adenosine) and γ-aminobutyric acidergic neurotransmission, was also postulated. Neuropeptides and peptide hormones are potent modulators of synaptic activity, and their levels are regulated by metabolic states. This is the case for neuroactive peptides such as neuropeptide Y, galanin, cholecystokinin, and peptide hormones such as leptin, adiponectin, and growth hormone-releasing peptides (GHRPs). In particular, the GHRP ghrelin and its related peptide des-acyl ghrelin are well-known controllers of energy homeostasis, food intake, and lipid metabolism. Notably, ghrelin has also been shown to regulate the neuronal excitability and epileptic activation of neuronal networks. Several lines of evidence suggest that GHRPs are upregulated in response to starvation and, particularly, in patients affected by anorexia and cachexia, all conditions in which also ketone bodies are upregulated. Moreover, starvation and anorexia nervosa are accompanied by changes in other peptide hormones such as adiponectin, which has received less attention. Adipocytokines such as adiponectin have also been involved in modulating epileptic activity. Thus, neuroactive peptides whose plasma levels and activity change in the presence of ketogenesis might be potential candidates for elucidating the neurohormonal

  12. Identification of the sAPRIL Binding Peptide and Its Growth Inhibition Effects in the Colorectal Cancer Cells

    PubMed Central

    Liu, Fang; Li, Jing; He, Mei-rong

    2015-01-01

    Background A proliferation-inducing ligand (APRIL) is a member of the tumor necrosis factor (TNF) super family. It binds to its specific receptors and is involved in multiple processes during tumorigenesis and tumor cells proliferation. High levels of APRIL expression are closely correlated to the growth, metastasis, and 5-FU drug resistance of colorectal cancer. The aim of this study was to identify a specific APRIL binding peptide (BP) able to block APRIL activity that could be used as a potential treatment for colorectal cancer. Methods A phage display library was used to identify peptides that bound selectively to soluble recombinant human APRIL (sAPRIL). The peptides with the highest binding affinity for sAPRIL were identified using ELISA. The effects of sAPRIL-BP on cell proliferation and cell cycle/apoptosis in vitro were evaluated using the CCK-8 assay and flow cytometry, respectively. An in vivo mouse model of colorectal cancer was used to determine the anti-tumor efficacy of the sAPRIL-BP. Results Three candidate peptides were characterized from eight phage clones with high binding affinity for sAPRIL. The peptide with the highest affinity was selected for further characterization. The identified sAPRIL-BP suppressed tumor cell proliferation and cell cycle progression in LOVO cells in a dose-dependent manner. In vivo in a mouse colorectal challenge model, the sAPRIL-BP reduced the growth of tumor xenografts in nude mice by inhibiting proliferation and inducing apoptosis intratumorally. Moreover, in an in vivo metastasis model, sAPRIL-BP reduced liver metastasis of colorectal cancer cells. Conclusions sAPRIL-BP significantly suppressed tumor growth in vitro and in vivo and might be a candidate for treating colorectal cancers that express high levels of APRIL. PMID:25826583

  13. The Host Defense Peptide Cathelicidin Is Required for NK Cell-Mediated Suppression of Tumor Growth

    PubMed Central

    Büchau, Amanda S.; Morizane, Shin; Trowbridge, Janet; Schauber, Jürgen; Kotol, Paul; Bui, Jack D.; Gallo, Richard L.

    2010-01-01

    Tumor surveillance requires the interaction of multiple molecules and cells that participate in innate and the adaptive immunity. Cathelicidin was initially identified as an antimicrobial peptide, although it is now clear that it fulfills a variety of immune functions beyond microbial killing. Recent data have suggested contrasting roles for cathelicidin in tumor development. Because its role in tumor surveillance is not well understood, we investigated the requirement of cathelicidin in controlling transplantable tumors in mice. Cathelicidin was observed to be abundant in tumor-infiltrating NK1.1+ cells in mice. The importance of this finding was demonstrated by the fact that cathelicidin knockout mice (Camp−/−) permitted faster tumor growth than wild type controls in two different xenograft tumor mouse models (B16.F10 and RMA-S). Functional in vitro analyses found that NK cells derived from Camp−/− versus wild type mice showed impaired cytotoxic activity toward tumor targets. These findings could not be solely attributed to an observed perforin deficiency in freshly isolated Camp−/− NK cells, because this deficiency could be partially restored by IL-2 treatment, whereas cytotoxic activity was still defective in IL-2-activated Camp−/− NK cells. Thus, we demonstrate a previously unrecognized role of cathelicidin in NK cell antitumor function. PMID:19949065

  14. Regulation of growth-blocking peptide expression during embryogenesis of the cabbage army worm

    SciTech Connect

    Tsuzuki, Seiji; Sekiguchi, Shiroh; Hayakawa, Yoichi . E-mail: hayakayo@cc.saga-u.ac.jp

    2005-10-07

    Growth-blocking peptide (GBP) is an insect cytokine with diverse biological functions. Northern blot analysis revealed high heterogeneity in the size distribution of GBP mRNAs as well as in the tissues where they are detected. The s patio-temporal transcription pattern is dynamic, especially during embryogenesis. Gel shift assays demonstrated that the cabbage army worm embryo nuclear extract specifically binds to a 178-bp element, at position +234 to +411 from the transcription start site of the 1.3 kb GBP transcript, in which two Drosophila Deformed (DfD) binding sites are repeated in tandem. The specific binding between this element and Dfd was demonstrated using recombinant cabbage armyworm Dfd protein. Silencing the Dfd expression in embryos by treating with DfD double-stranded RNA did not reduce the expression level of GBP, but ectopic GBP expression was observed in the lateral region of the embryo, suggesting that DD could serve as a transcriptional repressor for the GBP gene.

  15. Identification and Evaluation of Cryoprotective Peptides from Chicken Collagen: Ice-Growth Inhibition Activity Compared to That of Type I Antifreeze Proteins in Sucrose Model Systems.

    PubMed

    Du, Lihui; Betti, Mirko

    2016-06-29

    The ability of chicken collagen peptides to inhibit the growth of ice crystals was evaluated and compared to that of fish antifreeze proteins (AFPs). This ice inhibition activity was assessed using a polarized microscope by measuring ice crystal dimensions in a sucrose model system with and without collagen peptides after seven thermal cycles. The system was stabilized at -25 °C and cycled between -16 and -12 °C. Five candidate peptides with ice inhibition activity were identified using liquid chromatography and tandem mass spectrometry and were then synthesized. Their ice inhibition capacity was compared to that of type I AFPs in a 23% sucrose model system. Specific collagen peptides with certain amino acid sequences reduced the extent of ice growth by approximately 70% at a relatively low concentration (1 mg/mL). These results suggest that specific collagen peptides may act in a noncolligative manner, inhibiting ice crystal growth like type I AFPs, but less efficiently. PMID:27293017

  16. Fibroblast Growth Factor-Peptide Improves Barrier Function and Proliferation in Human Keratinocytes After Radiation

    SciTech Connect

    Zhang Kunzhong; Tian Yeping; Yin Liangjie; Zhang Mei; Beck, Lisa A.; Zhang, Bingrong; Okunieff, Paul; Zhang Lurong; Vidyasagar, Sadasivan

    2011-09-01

    Purpose: Epidermal keratinocytes, which can be severely damaged after ionizing radiation (IR), are rapid turnover cells that function as a barrier, protecting the host from pathogenic invasion and fluid loss. We tested fibroblast growth factor-peptide (FGF-P), a small peptide derived from the receptor-binding domain of FGF-2, as a potential mitigator of radiation effects via proliferation and the barrier function of keratinocytes. Methods and Materials: Keratinocytes isolated from neonatal foreskin were grown on transwells. After being exposed to 0, 5, or 10 Gy IR, the cells were treated with a vehicle or FGF-P. The permeability of IR cells was assessed by using transepithelial electrical resistance (TEER) and a paracellular tracer flux of fluorescein isothiocyanate-conjugated bovine serum albumin (FITC-BSA) with Ussing chambers. The cell proliferation was measured with yellow tetrazolium salt (MTT) and tritiated thymidine ([{sup 3}H]-TdR) assays. The phosphorylation of extracellular signal-regulated kinases (ERK) was measured in an enzyme-linked immunosorbent (ELISA)-like assay, and the proteins related to tight junctions (TJ) and adherens junctions (AJ) were examined with Western blotting. We used a mouse model to assess the ability of FGF-P to promote the healing of skin {beta} burns created with a strontium applicator. Results: We found (1) FGF-P reduced the permeability of irradiated keratinocytes, as evidenced by increased TEER and decreased diffusion of FITC-BSA, both associated with the regulation of different proteins and levels of TJ and AJ; and (2) FGF-P enhanced the proliferation of irradiated keratinocytes, as evidenced by increased MTT activity and [{sup 3}H]-TdR incorporation, which was associated with activation of the ERK pathway; and (3) FGF-P promoted the healing of skin {beta} burns. Conclusions: FGF-P enhances the barrier function, including up-regulation of TJ proteins, increases proliferation of human keratinocytes, and accelerates the

  17. Root Growth Response to Application and Overexpression of Heterodera glycines CLE peptides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant CLAVATA3/ESR(CLE)-like peptides have been shown to be involved with several aspects of plant development including maintenance of stem cell pools in the root meristem. Interestingly, parasitism genes, HgCLE-1 and HgCLE-2, encoding secreted CLE-like peptides are expressed in the dorsal esophage...

  18. Multiple biological activities for two peptides derived from the nerve growth factor precursor

    SciTech Connect

    Dicou, Eleni . E-mail: dicou@ipmc.cnrs.fr

    2006-09-01

    ProNGF can be cleaved proteolytically at dibasic residues and liberates two other peptides beside NGF, LIP1 a 29 amino acid (aa) peptide and LIP2 a 38 aa peptide. These peptides were found present in the rat intestine and shown to induce rapid phosphorylation of the Trk receptor in cell lines. The present study describes several novel biological properties for these peptides. They exert an anti-proliferative effect on the mitogenic activity of estrogen and IGF in MCF-7 cells. They protect against in vivo induction of excitotoxic lesions by the glutamatergic analogue ibotenate injected into the developing mouse brain and against in vitro NMDA-induced cell death in primary neuronal cultures. They bind to murine microglial cells and induce phosphorylation of Akt. These results suggest a role for LIP1 and LIP2 in cell survival.

  19. Thiol-Disulfide Exchange in Peptides Derived from Human Growth Hormone during Lyophilization and Storage in the Solid State

    PubMed Central

    Chandrasekhar, Saradha; Topp, Elizabeth M.

    2015-01-01

    Lyophilization (freeze-drying) is frequently used to stabilize protein therapeutics. However, covalent modifications such as thiol-disulfide exchange and disulfide scrambling can occur even in the solid state. The effects of lyophilization and storage of lyophilized powders on the mechanism and kinetics of thioldisulfide exchange have not been elucidated and are explored here. Reaction kinetics were monitored in peptides corresponding to tryptic fragments of human growth hormone (T20 + T20-T21 or T20 + cT20-T21) during different stages of lyophilization and during storage of the lyophilized powders at 22 °C and ambient RH. The concentrations of reactants and products were determined using RP-HPLC and product identity confirmed using LC-MS. Loss of native disulfide was observed for the reaction of T20 with both linear (T20-T21) and cyclic (cT20-T21) peptides during the primary drying step, however, the native disulfides were regenerated during secondary drying with no further change till the end of lyophilization. Deviations from Arrhenius parameters predicted from solution studies and the absence of buffer effects during lyophilization suggest that factors such as temperature, initial peptide concentration, buffer type and concentration do not influence thiol-disulfide exchange during lyophilization. Results from a ‘cold finger’ method used to study peptide adsorption to ice indicate that there is no preferential adsorption to the ice surface and that its presence may not influence disulfide reactivity during primary drying. Overall, reaction rates and product distribution differ for the reaction of T20 with T20-T21 or cT20-T21 in the solid state and aqueous solution, while the mechanism of thiol-disulfide remains unchanged. Increased reactivity of the cyclic peptide in the solid state suggests that peptide cyclization does not offer protection against lyophilization and that damage induced by a process stress further affects storage stability at 22 °C and

  20. A novel nanoparticle containing neuritin peptide with grp170 induces a CTL response to inhibit tumor growth.

    PubMed

    Yuan, Bangqing; Shen, Hanchao; Su, Tonggang; Lin, Li; Chen, Ting; Yang, Zhao

    2015-10-01

    Malignant glioma is among the most challenging of all cancers to treat successfully. Despite recent advances in surgery, radiotherapy and chemotherapy, current treatment regimens have only a marginal impact on patient survival. In this study, we constructed a novel nanoparticle containing neuritin peptide with grp170. The nanoparticle could elicit a neuritin-specific cytotoxic T lymphocyte response to lyse glioma cells in vitro. In addition, the nanoparticle could inhibit tumor growth and improve the lifespan of tumor-bearing mice in vivo. Taken together, the results demonstrated that the nanoparticle can inhibit tumor growth and represents a promising therapy for glioma. PMID:26290143

  1. Growth of Streptococcus mutans in Biofilms Alters Peptide Signaling at the Sub-population Level

    PubMed Central

    Shields, Robert C.; Burne, Robert A.

    2016-01-01

    Streptococcus mutans activates multiple cellular processes in response to the formation of a complex between comX-inducing peptide (XIP) and the ComR transcriptional regulator. Bulk phase and microfluidic experiments previously revealed that ComR-dependent activation of comX is altered by pH and by carbohydrate source. Biofilm formation is a major factor in bacterial survival and virulence in the oral cavity. Here, we sought to determine the response of S. mutans biofilm cells to XIP during different stages of biofilm maturation. Using flow cytometry and confocal microscopy, we showed that exogenous addition of XIP to early biofilms resulted in robust comX activation. However, as the biofilms matured, increasing amounts of XIP were required to activate comX expression. Single-cell analysis demonstrated that the entire population was responding to XIP with activation of comX in early biofilms, but only a sub-population was responding in mature biofilms. The sub-population response of mature biofilms was retained when the cells were dispersed and then treated with XIP. The proportion and intensity of the bi-modal response of mature biofilm cells was altered in mutants lacking the Type II toxins MazF and RelE, or in a strain lacking the (p)ppGpp synthase/hydrolase RelA. Thus, competence signaling is markedly altered in cells growing in mature biofilms, and pathways that control cell death and growth/survival decisions modulate activation of comX expression in these sessile populations. PMID:27471495

  2. Evolution of potent and stable placental-growth-factor-1-targeting CovX-bodies from phage display peptide discovery.

    PubMed

    Bower, Kristen E; Lam, Son N; Oates, Bryan D; Del Rosario, Joselyn R; Corner, Emily; Osothprarop, Trina F; Kinhikar, Arvind G; Hoye, Julie A; Preston, R Ryan; Murphy, Robert E; Campbell, Lioudmila A; Huang, Hanhua; Jimenez, Judith; Cao, Xia; Chen, Gang; Ainekulu, Zemeda W; Datt, Aakash B; Levin, Nancy J; Doppalapudi, Venkata R; Pirie-Shepherd, Steven R; Bradshaw, Curt; Woodnutt, Gary; Lappe, Rodney W

    2011-03-10

    Novel phage-derived peptides are the first reported molecules specifically targeting human placental growth factor 1 (PlGF-1). Phage data enabled peptide modifications that decreased IC(50) values in PlGF-1/VEGFR-1 competition ELISA from 100 to 1 μM. Peptides exhibiting enhanced potency were bioconjugated to the CovX antibody scaffold 1 (CVX-2000), generating bivalent CovX-Bodies with 2 nM K(D) against PlGF-1. In vitro and in vivo peptide cleavage mapping studies enabled the identification of proteolytic hotspots that were subsequently chemically modified. These changes decreased IC(50) to 0.4 nM and increased compound stability from 5% remaining at 6 h after injection to 35% remaining at 24 h with a β phase half-life of 75 h in mice. In cynomolgus monkey, a 78 h β half-life was observed for lead compound 2. The pharmacological properties of 2 are currently being explored. PMID:21280651

  3. Recombinant vascular basement-membrane-derived multifunctional peptide inhibits angiogenesis and growth of hepatocellular carcinoma

    PubMed Central

    Wu, You-Hua; Cao, Jian-Guo; Xiang, Hong-Lin; Xia, Hong; Qin, Yong; Huang, A-Ji; Xiao, Di; Xu, Fang

    2009-01-01

    AIM: To investigate the anti-angiogenic and anti-tumor activities of recombinant vascular basement membrane-derived multifunctional peptide (rVBMDMP) in hepatocellular carcinoma (HCC). METHODS: HepG2, Bel-7402, Hep-3B, HUVE-12 and L-02 cell lines were cultured in vitro and the inhibitory effect of rVBMDMP on proliferation of cells was detected by MTT assay. The in vivo antitumor efficacy of rVBMDMP on HCC was assessed by HepG2 xenografts in nude mice. Distribution of rVBMDMP, mechanism by which the growth of HepG2 xenografts is inhibited, and microvessel area were observed by proliferating cell nuclear antigen (PCNA) and CD31 immunohistochemistry. RESULTS: MTT assay showed that rVBMDMP markedly inhibited the proliferation of human HCC (HepG2, Bel-7402, Hep-3B) cells and human umbilical vein endothelial (HUVE-12) cells in a dose-dependent manner, with little effect on the growth of L-02 cells. When the IC50 was 4.68, 7.65, 8.96, 11.65 and 64.82 μmol/L, respectively, the potency of rVBMDMP to HepG2 cells was similar to 5-fluorouracil (5-FU) with an IC50 of 4.59 μmol/L. The selective index of cytotoxicity to HepG2 cells of rVBMDMP was 13.8 (64.82/4.68), which was higher than that of 5-FU [SI was 1.9 (8.94/4.59)]. The VEGF-targeted recombinant humanized monoclonal antibody bevacizumab (100 mg/L) did not affect the proliferation of HepG2, Bel-7402, Hep-3B and L-02 cells, but the growth inhibitory rate of bevacizumab (100 mg/L) to HUVE-12 cells was 87.6% ± 8.2%. Alternis diebus intraperitoneal injection of rVBMDMP suppressed the growth of HepG2 xenografts in a dose-dependent manner. rVBMDMP (1, 3, 10 mg/kg) decreased the tumor weight by 12.6%, 55.9% and 79.7%, respectively, compared with the vehicle control. Immunohistochemical staining of rVBMDMP showed that the positive area rates (2.2% ± 0.73%, 4.5% ± 1.3% and 11.5% ± 3.8%) in rVBMDMP treated group (1, 3, 10 mg/kg) were significantly higher than that (0.13% ± 0.04%) in the control group (P < 0.01). The positive

  4. The cell-penetrating peptide, Pep-1, has activity against intracellular chlamydial growth but not extracellular forms of Chlamydia trachomatis

    PubMed Central

    Park, Narae; Yamanaka, Kinrin; Tran, Dat; Chandrangsu, Pete; Akers, Johnny C.; de Leon, Jessica C.; Morrissette, Naomi S.; Selsted, Michael E.; Tan, Ming

    2009-01-01

    Objectives In the course of studies to identify novel treatment strategies against the pathogenic bacterium, Chlamydia, we tested the carrier peptide, Pep-1, for activity against an intracellular infection. Methods Using a cell culture model of Chlamydia trachomatis infection, the effect of Pep-1 was measured by incubating the peptide with extracellular chlamydiae prior to infection, or by adding Pep-1 to the medium at varying times after infection, and assaying for inhibition of inclusion formation. Results Pep-1 had a concentration-dependent effect on chlamydial growth with 100% inhibition of inclusion formation at 8 mg/L peptide. There was a window of susceptibility during the chlamydial developmental cycle with a maximal effect when treatment was begun within 12 h of infection. Pep-1 treatment caused a severe reduction in the production of infectious progeny even when started later, when the effect on inclusion formation was minimal. Furthermore, electron micrographs showed a paucity of progeny elementary bodies (EBs) in the inclusion. In contrast, pre-incubation of EBs with Pep-1 prior to infection did not affect inclusion formation. Taken together, these findings indicate that the antichlamydial effect was specific for the intracellular stage of chlamydial infection. By comparison, Pep-1 had no antimicrobial activity against Escherichia coli and Staphylococcus aureus or the obligate intracellular parasite, Toxoplasma gondii. Conclusions Pep-1 has antichlamydial activity by preventing intracellular chlamydial growth and replication but has no effect on extracellular chlamydiae. PMID:18957395

  5. Mass spectrometric identification, sequence evolution, and intraspecific variability of dimeric peptides encoded by cockroach akh genes.

    PubMed

    Sturm, Sebastian; Predel, Reinhard

    2015-02-01

    Neuropeptides are structurally the most diverse group of messenger molecules of the nervous system. Regarding neuropeptide identification, distribution, function, and evolution, insects are among the best studied invertebrates. Indeed, more than 100 neuropeptides are known from single species. Most of these peptides can easily be identified by direct tissue or cell profiling using MALDI-TOF MS. In these experiments, protein hormones with extensive post-translational modifications such as inter- and intramolecular disulfides are usually missed. It is evident that an exclusion of these bioactive molecules hinders the utilization of direct profiling methods in comprehensive peptidomic analyses. In the current study, we focus on the detection and structural elucidation of homo- and heterodimeric adipokinetic hormone precursor-related peptides (APRPs) of cockroaches. The physiological relevance of these molecules with highly conserved sequences in insects is still uncertain. Sequence similarities with vertebrate growth hormone-releasing factors have been reported, but remarkably, few data regarding APRP processing exist and these data are restricted to locusts. Here, we elucidated sequences of carbamidomethylated APRP monomers of different cockroaches by means of MALDI-TOF MS(2), and we were able to identify a surprisingly large number of APRP sequences, resulting either from intraspecific amino acid substitutions within the APRP sequences or C-terminal truncated APRPs. PMID:25524231

  6. NOVEL MECHANISMS TO PROMOTE GROWTH IN A COMMERCIALLY-IMPORTANT TELEOST, THE RAINBOW TROUT (ONCORHYNCHUS MYKISS)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The pituitary hormone, growth hormone (GH), and its intermediary, insulin-like growth factor I (IGF-I), have fundamental roles in the regulation of growth in teleosts. Growth hormone secretion is principally controlled by the two neuroendocrine factors, growth hormone-releasing hormone (GHRH) and s...

  7. Phenylalanine-Rich Peptides Potently Bind ESAT6, a Virulence Determinant of Mycobacterium tuberculosis, and Concurrently Affect the Pathogen's Growth

    PubMed Central

    Kumar, Krishan; Tharad, Megha; Ganapathy, Swetha; Ram, Geeta; Narayan, Azeet; Khan, Jameel Ahmad; Pratap, Rana; Ghosh, Anamika; Samuchiwal, Sachin Kumar; Kumar, Sushil; Bhalla, Kuhulika; Gupta, Deepti; Natarajan, Krishnamurthy; Singh, Yogendra; Ranganathan, Anand

    2009-01-01

    Background The secretory proteins of Mycobacterium tuberculosis (M. tuberculosis) have been known to be involved in the virulence, pathogenesis as well as proliferation of the pathogen. Among this set, many proteins have been hypothesized to play a critical role at the genesis of the onset of infection, the primary site of which is invariably the human lung. Methodology/Principal Findings During our efforts to isolate potential binding partners of key secretory proteins of M. tuberculosis from a human lung protein library, we isolated peptides that strongly bound the virulence determinant protein Esat6. All peptides were less than fifty amino acids in length and the binding was confirmed by in vivo as well as in vitro studies. Curiously, we found all three binders to be unusually rich in phenylalanine, with one of the three peptides a short fragment of the human cytochrome c oxidase-3 (Cox-3). The most accessible of the three binders, named Hcl1, was shown also to bind to the Mycobacterium smegmatis (M. smegmatis) Esat6 homologue. Expression of hcl1 in M. tuberculosis H37Rv led to considerable reduction in growth. Microarray analysis showed that Hcl1 affects a host of key cellular pathways in M. tuberculosis. In a macrophage infection model, the sets expressing hcl1 were shown to clear off M. tuberculosis in much greater numbers than those infected macrophages wherein the M. tuberculosis was not expressing the peptide. Transmission electron microscopy studies of hcl1 expressing M. tuberculosis showed prominent expulsion of cellular material into the matrix, hinting at cell wall damage. Conclusions/Significance While the debilitating effects of Hcl1 on M. tuberculosis are unrelated and not because of the peptide's binding to Esat6–as the latter is not an essential protein of M. tuberculosis–nonetheless, further studies with this peptide, as well as a closer inspection of the microarray data may shed important light on the suitability of such small phenylalanine

  8. In vitro effect of. Delta. sup 9 -tetrahydrocannabinol to stimulate somatostatin release and block that of luteinizing hormone-releasing hormone by suppression of the release of prostaglandin E sub 2

    SciTech Connect

    Rettori, V.; Aguila, M.C.; McCann, S.M. ); Gimeno, M.F.; Franchi, A.M. )

    1990-12-01

    Previous in vivo studies have shown that {Delta}{sup 9}-tetrahydrocannabinol (THC), the principal active ingredient in marijuana, can suppress both luteinizing hormone (LH) and growth hormone (GH) secretion after its injection into the third ventricle of conscious male rats. The present studies were deigned to determine the mechanism of these effects. Various doses of THC were incubated with either stalk median eminence fragments (MEs) or mediobasal hypothalamic (MBH) fragments in vitro. Although THC (10 nM) did not alter basal release of LH-releasing hormone (LHRH) from MEs in vitro, it completely blocked the stimulatory action of dopamine or nonrepinephrine on LHRH release. The effective doses to block LHRH release were associated with a blockade of synthesis and release of prostaglandin E{sub 2} (PGE{sub 2}) from MBH in vitro. In contrast to the suppressive effect of THC on LHRH release, somatostatin release from MEs was enhanced in a dose-related manner with a minimal effective dose of 1 nM. Since PGE{sub 2} suppresses somatostatin release, this enhancement may also be related to the suppressive effect of THC on PGE{sub 2} synthesis and release. The authors speculate that these actions are mediated by the recently discovered THC receptors in the tissue. The results indicate that the suppressive effect of THC on LH release is mediated by a blockade of LHRH release, whereas the suppressive effect of the compound on growth hormone release is mediated, at least in part, by a stimulation of somatostatin release.

  9. Interactions of GRF(1-29)NH2 with plasma proteins and their effects on the release of the peptide from a PLAGA matrix.

    PubMed

    Mariette, B; Coudane, J; Vert, M

    2005-09-01

    The administration of the GRF(1-29)NH2 Growth Hormone Releasing Hormone analog is known as relevant of the concept of drug delivery system using a bioresorbable matrix. However, the release of this peptide from poly(dl-lactic acid-co-glycolic acid) matrices is affected by its insolubility at neutral in salted media and in plasma as well. In order to investigate the origin and the nature of the insolubility in these media in more details, the precipitates collected when the peptide was set in contact with saline, isotonic pH=7.4 phosphate buffer and plasma were analyzed by various techniques, namely weighting, gel chromatography, 1D- and 2D-immunoelectrophoresis, and dialysis to discern the soluble from the insoluble or aggregated fractions. It is shown that precipitation in protein-free salted media is due to a salting out phenomenon complemented by the neutralization of the solubilizing electrostatic charges in the isotonic buffer. In contrast, the precipitation in plasma is due to inter polyelectrolyte-type complexation that involved polyanionic proteins having a rather low isoelectric point like albumin, transferin, haptoglobulin and IgG immunoglobulins. When a rather large quantity of GRF(1-29)NH2 was entrapped in bioresorbable pellets working at a percolating regime after subcutaneous implantation in rats, the peptide was slowly released despite the complexation with plasma proteins. However only a very small part of the peptide was found in blood, this small part being still large enough to cause a detectable increase of the circulating growth hormone concentration. Attempts made to increase the solubility of the peptide in plasma were successful when the peptide was combined with arginine, an amino acid known to promote the poor hormonal activity of injected GRF(1-29)NH2 solutions under clinical conditions. PMID:15987661

  10. Effect of intravenous bovine growth hormone or human pancreatic growth hormone-releasing factor on milk production and plasma hormones and metabolites in sheep.

    PubMed

    Hart, I C; Chadwick, P M; James, S; Simmonds, A D

    1985-05-01

    Although it is well known that exogenous bovine GH (bGH) increases milk yield in ruminants it has not been possible to determine whether an increase in endogenous GH secretion has the same effect. The recent isolation of human pancreatic GH-releasing factor (hpGRF-44) has enabled this comparison of the effects of bGH and hpGRF-44 on milk production in sheep. Three pairs of Dorset ewes underwent three 4-day treatments according to a Latin square design. Treatment 1 involved: 2-hourly i.v. injections (approximately 3.0 ml) of bGH (15 micrograms/kg; 1.8 units/mg); treatment 2: 2-hourly i.v. injections (approximately 3.0 ml) of hpGRF-44 (0.6 microgram/kg); treatment 3: 2-hourly i.v. injections (3.0 ml) of the vehicle. Treatment periods were separated by 10 days. Sheep were milked twice daily and the milk was analysed for fat, protein and lactose. Blood samples (5.0 ml) were taken before and at 15, 45, 75 and 100 min after every third injection throughout the 4 days. Plasma was analysed for insulin, glucose, urea and non-esterified fatty acids (NEFA). The changes in plasma GH stimulated by hpGRF-44 were consistent and repeatable throughout the 4 days of treatment.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3921646

  11. Metabolic Effects of a Growth Hormone-Releasing Factor in Obese Subjects with Reduced Growth Hormone Secretion: A Randomized Controlled Trial

    PubMed Central

    Makimura, Hideo; Feldpausch, Meghan N.; Rope, Alison M.; Hemphill, Linda C.; Torriani, Martin; Lee, Hang

    2012-01-01

    Context: Obesity is associated with reduced GH secretion and increased cardiovascular disease risk. Objective: We performed this study to determine the effects of augmenting endogenous GH secretion on body composition and cardiovascular disease risk indices in obese subjects with reduced GH secretion. Design, Patients and Methods: A randomized, double-blind, placebo-controlled study was performed involving 60 abdominally obese subjects with reduced GH secretion. Subjects received tesamorelin, a GHRH1–44 analog, 2 mg once daily, or placebo for 12 months. Abdominal visceral adipose tissue (VAT) was assessed by abdominal computed tomography scan, and carotid intima-media thickness (cIMT) was assessed by ultrasound. Treatment effect was determined by longitudinal linear mixed-effects modeling. Results: VAT [−16 ± 9 vs.19 ± 9 cm2, tesamorelin vs. placebo; treatment effect (95% confidence interval): −35 (−58, −12) cm2; P = 0.003], cIMT (−0.03 ± 0.01 vs. 0.01 ± 0.01 mm; −0.04 (−0.07, −0.01) mm; P = 0.02), log C-reactive protein (−0.17 ± 0.04 vs. −0.03 ± 0.05 mg/liter; −0.15 (−0.30, −0.01) mg/liter, P = 0.04), and triglycerides (−26 ± 16 vs. 12 ± 8 mg/dl; −37 (−67, −7) mg/dl; P = 0.02) improved significantly in the tesamorelin group vs. placebo. No significant effects on abdominal sc adipose tissue (−6 ± 6 vs. 3 ± 11 cm2; −10 (−32, +13) cm2; P = 0.40) were seen. IGF-I increased (86 ± 21 vs. −6 ± 8 μg/liter; 92 (+52, +132) μg/liter; P < 0.0001). No changes in fasting, 2-h glucose, or glycated hemoglobin were seen. There were no serious adverse events or differences in adverse events between the groups. Conclusion: Among obese subjects with relative reductions in GH, tesamorelin selectively reduces VAT without significant effects on sc adipose tissue and improves triglycerides, C-reactive protein, and cIMT, without aggravating glucose. PMID:23015655

  12. A nerve growth factor peptide retards seizure development and inhibits neuronal sprouting in a rat model of epilepsy.

    PubMed Central

    Rashid, K; Van der Zee, C E; Ross, G M; Chapman, C A; Stanisz, J; Riopelle, R J; Racine, R J; Fahnestock, M

    1995-01-01

    Kindling, an animal model of epilepsy wherein seizures are induced by subcortical electrical stimulation, results in the upregulation of neurotrophin mRNA and protein in the adult rat forebrain and causes mossy fiber sprouting in the hippocampus. Intraventricular infusion of a synthetic peptide mimic of a nerve growth factor domain that interferes with the binding of neurotrophins to their receptors resulted in significant retardation of kindling and inhibition of mossy fiber sprouting. These findings suggest a critical role for neurotrophins in both kindling and kindling-induced synaptic reorganization. Images Fig. 2 PMID:7568161

  13. Characterization and in vitro biological evaluation of mineral/osteogenic growth peptide nanocomposites synthesized biomimetically on titanium

    NASA Astrophysics Data System (ADS)

    Chen, Cen; Kong, Xiangdong; Zhang, Sheng-Min; Lee, In-Seop

    2015-04-01

    Nanocomposite layers of mineral/osteogenic growth peptide (OGP) were synthesized on calcium phosphate coated titanium substrates by immersing in calcium-phosphate buffer solution containing OGP. Peptide incorporated mineral was characterized by determining quantity loaded, effects on mineral morphology and structure. Also, the biological activity was investigated by cell adhesion, proliferation assay, and measurement of alkaline phosphatase (ALP) activity. X-ray photoelectron spectroscopy (XPS) and micro-bicinchoninic acid (BCA) assay revealed that OGP was successfully incorporated with mineral and the amount was increased with immersion time. Incorporated OGP changed the mineral morphology from sharp plate-like shape to more rounded one, and the octacalcium phosphate structure of the mineral was gradually transformed into apatite. With confocal microscopy to examine the incorporation of fluorescently labeled peptide, OGP was evenly distributed throughout mineral layers. Mineral/OGP nanocomposites promoted cell adhesion and proliferation, and also increased ALP activity of mesenchymal stem cells (MSCs). Results presented here indicated that the mineral/OGP nanocomposites formed on titanium substrates had the potential for applications in dental implants.

  14. Thiol-disulfide exchange in peptides derived from human growth hormone during lyophilization and storage in the solid state.

    PubMed

    Chandrasekhar, Saradha; Topp, Elizabeth M

    2015-04-01

    Lyophilization (freeze-drying) is frequently used to stabilize protein therapeutics. However, covalent modifications such as thiol-disulfide exchange and disulfide scrambling can occur even in the solid state. The effects of lyophilization and storage of lyophilized powders on the mechanism and kinetics of thiol-disulfide exchange have not been elucidated and are explored here. Reaction kinetics was monitored in peptides corresponding to tryptic fragments of human growth hormone (T20 + T20-T21 or T20 + cT20-T21) during different stages of lyophilization and during storage of the lyophilized powders at 22°C and ambient RH. The concentrations of reactants and products were determined using RP-HPLC and product identity confirmed using liquid chromatography-mass spectrometry. Loss of native disulfide was observed for the reaction of T20 with both linear (T20-T21) and cyclic (cT20-T21) peptides during the primary drying step; however, the native disulfides were regenerated during secondary drying with no further change till the end of lyophilization. Deviations from Arrhenius parameters predicted from solution studies and the absence of buffer effects during lyophilization suggest that factors such as temperature, initial peptide concentration, buffer type, and concentration do not influence thiol-disulfide exchange during lyophilization. Results from a "cold finger" method used to study peptide adsorption to ice indicate that there is no preferential adsorption to the ice surface and that its presence may not influence disulfide reactivity during primary drying. Overall, reaction rates and product distribution differ for the reaction of T20 with T20-T21 or cT20-T21 in the solid state and aqueous solution, whereas the mechanism of thiol-disulfide remains unchanged. Increased reactivity of the cyclic peptide in the solid state suggests that peptide cyclization does not offer protection against lyophilization and that damage induced by a process stress further affects

  15. Transgenic tobacco expressing a modified spider peptide inhibits the growth of plant pathogens and insect larvae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The gene encoding lycotoxin I, an amphipathic pore-forming peptide, was modified to increase oral toxicity to insects. One of the most active modified genes was then constitutively expressed in tobacco (Nicotiana tabacum) and transformants were evaluated for insect and disease resistance. Pathogenic...

  16. A PCNA-Derived Cell Permeable Peptide Selectively Inhibits Neuroblastoma Cell Growth

    PubMed Central

    Gu, Long; Smith, Shanna; Li, Caroline; Hickey, Robert J.; Stark, Jeremy M.; Fields, Gregg B.; Lang, Walter H.; Sandoval, John A.; Malkas, Linda H.

    2014-01-01

    Proliferating cell nuclear antigen (PCNA), through its interaction with various proteins involved in DNA synthesis, cell cycle regulation, and DNA repair, plays a central role in maintaining genome stability. We previously reported a novel cancer associated PCNA isoform (dubbed caPCNA), which was significantly expressed in a broad range of cancer cells and tumor tissues, but not in non-malignant cells. We found that the caPCNA-specific antigenic site lies between L126 and Y133, a region within the interconnector domain of PCNA that is known to be a major binding site for many of PCNA's interacting proteins. We hypothesized that therapeutic agents targeting protein-protein interactions mediated through this region may confer differential toxicity to normal and malignant cells. To test this hypothesis, we designed a cell permeable peptide containing the PCNA L126-Y133 sequence. Here, we report that this peptide selectively kills human neuroblastoma cells, especially those with MYCN gene amplification, with much less toxicity to non-malignant human cells. Mechanistically, the peptide is able to block PCNA interactions in cancer cells. It interferes with DNA synthesis and homologous recombination-mediated double-stranded DNA break repair, resulting in S-phase arrest, accumulation of DNA damage, and enhanced sensitivity to cisplatin. These results demonstrate conceptually the utility of this peptide for treating neuroblastomas, particularly, the unfavorable MYCN-amplified tumors. PMID:24728180

  17. A cyclic peptide derived from alpha-fetoprotein inhibits the proliferative effects of the epidermal growth factor and estradiol in MCF7 cells.

    PubMed

    Torres, Cristian; Antileo, Elmer; Epuñán, Maráa José; Pino, Ana María; Valladares, Luis Emilio; Sierralta, Walter Daniel

    2008-06-01

    A cyclic peptide derived from the active domain of alpha-fetoprotein (AFP) significantly inhibited the proliferation of MCF7 cells stimulated with the epidermal growth factor (EGF) or estradiol (E2). The action of these three agents on cell growth was independent of the presence of calf serum in the culture medium. Our results demonstrated that the cyclic peptide interfered markedly with the regulation of MAPK by activated c-erbB2. The cyclic peptide showed no effect on the E2-stimulated release of matrix metalloproteinases 2 and 9 nor on the shedding of heparin-binding EGF into the culture medium. We propose that the AFP-derived cyclic peptide represents a valuable novel antiproliferative agent for treating breast cancer. PMID:18497971

  18. Growth promoting in vitro effect of synthetic cyclic RGD-peptides on human osteoblast-like cells attached to cancellous bone.

    PubMed

    Magdolen, Ursula; Auernheimer, Jörg; Dahmen, Claudia; Schauwecker, Johannes; Gollwitzer, Hans; Tübel, Jutta; Gradinger, Reiner; Kessler, Horst; Schmitt, Manfred; Diehl, Peter

    2006-06-01

    In tissue engineering, the application of biofunctional compounds on biomaterials such as integrin binding RGD-peptides has gained growing interest. Anchorage-dependent cells like osteoblasts bind to these peptides thus ameliorating the integration of a synthetic implant. In case sterilized bone grafts are used as substitutes for reconstruction of bone defects, the ingrowth of the implanted bone is often disturbed because of severe pretreatment such as irradiation or autoclaving, impairing the biological and mechanical properties of the bone. We report for the first time on the in vitro coating of the surface of freshly resected, cleaned bone discs with synthetic, cyclic RGD-peptides. For this approach, two different RGD-peptides were used, one containing two phosphonate anchors, the other peptide four of these binding moieties to allow efficient association of these reactive RGD-peptides to the inorganic bone matrix. Human osteoblast-like cells were cultured on RGD-coated bone discs and the adherence and growth of the cells were analyzed. Coating of bone discs with RGD-peptides did not improve the adhesion rate of osteoblast-like cells to the discs but significantly (up to 40%) accelerated growth of these cells within 8 days after attachment. This effect points to pretreatment of bone implants, especially at the critical interface area between the implanted bone and the non-resected residual bone structure, before re-implantation in order to stimulate and enhance osteointegration of a bone implant. PMID:16685410

  19. USE OF MOLECULAR BIOLOGICAL TECHNIQUES TO EVALUATE EFFECT OF ENDOGENOUS HORMONES AND A XENOBIOTIC PESTICIDE ON GROWTH OF SHEEPSHEAD MINNOW

    EPA Science Inventory

    We have developed a teleost model to screen physiological effects of endocrine disrupting chemicals (EDCs) on somatic growth. Growth is largely controlled by the endocrine system via the growth-hormone releasing hormone (GRF) - growth hormone (GH) - insulin-like growth factor (IG...

  20. Glucose-induced incretin hormone release and inactivation are differently modulated by oral fat and protein in mice.

    PubMed

    Gunnarsson, P Thomas; Winzell, Maria Sörhede; Deacon, Carolyn F; Larsen, Marianne O; Jelic, Katarina; Carr, Richard D; Ahrén, Bo

    2006-07-01

    Monounsaturated fatty acids, such as oleic acid (OA), and certain milk proteins, especially whey protein (WP), have insulinotropic effects and can reduce postprandial glycemia. This effect may involve the incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1). To explore this, we examined the release and inactivation of GIP and GLP-1 after administration of glucose with or without OA or WP through gastric gavage in anesthetized C57BL/6J mice. Insulin responses to glucose (75 mg) were 3-fold augmented by addition of WP (75 mg; P < 0.01), which was associated with enhanced oral glucose tolerance (P < 0.01). The insulin response to glucose was also augmented by addition of OA (34 mg; P < 0.05) although only 1.5-fold and with no associated increase in glucose elimination. The slope of the glucose-insulin curve was increased by OA (1.7-fold; P < 0.05) and by WP (4-fold; P < 0.01) compared with glucose alone, suggesting potentiation of glucose-stimulated insulin release. WP increased GLP-1 secretion (P < 0.01), whereas GIP secretion was unaffected. OA did not affect GIP or GLP-1 secretion. Nevertheless, WP increased the levels of both intact GIP and intact GLP-1 (both P < 0.01), and OA increased the levels of intact GLP-1 (P < 0.05). WP inhibited dipeptidyl peptidase IV activity in the proximal small intestine by 50% (P < 0.05), suggesting that luminal degradation of WP generates small fragments, which are substrates for dipeptidyl peptidase IV and act as competitive inhibitors. We therefore conclude that fat and protein may serve as exogenous regulators of secretion and inactivation of the incretin hormones with beneficial influences on glucose metabolism. PMID:16627575

  1. Three-dimensional nanofibrillar surfaces covalently modified with tenascin-C-derived peptides enhance neuronal growth in vitro.

    PubMed

    Ahmed, Ijaz; Liu, Hsing-Yin; Mamiya, Ping C; Ponery, Abdul S; Babu, Ashwin N; Weik, Thom; Schindler, Melvin; Meiners, Sally

    2006-03-15

    Current methods to promote growth of cultured neurons use two-dimensional (2D) glass or polystyrene surfaces coated with a charged molecule (e.g. poly-L-lysine (PLL)) or an isolated extracellular matrix (ECM) protein (e.g. laminin-1). However, these 2D surfaces represent a poor topological approximation of the three-dimensional (3D) architecture of the assembled ECM that regulates neuronal growth in vivo. Here we report on the development of a new 3D synthetic nanofibrillar surface for the culture of neurons. This nanofibrillar surface is composed of polyamide nanofibers whose organization mimics the porosity and geometry of the ECM. Neuronal adhesion and neurite outgrowth from cerebellar granule, cerebral cortical, hippocampal, motor, and dorsal root ganglion neurons were similar on nanofibers and PLL-coated glass coverslips; however, neurite generation was increased. Moreover, covalent modification of the nanofibers with neuroactive peptides derived from human tenascin-C significantly enhanced the ability of the nanofibers to facilitate neuronal attachment, neurite generation, and neurite extension in vitro. Hence the 3D nanofibrillar surface provides a physically and chemically stabile cell culture surface for neurons and, potentially, an exciting new opportunity for the development of peptide-modified matrices for use in strategies designed to encourage axonal regrowth following central nervous system injury. PMID:16345089

  2. Reducing Escherichia coli growth on a composite biomaterial by a surface immobilized antimicrobial peptide.

    PubMed

    Buckholtz, Gavin A; Reger, Nina A; Anderton, William D; Schimoler, Patrick J; Roudebush, Shana L; Meng, Wilson S; Miller, Mark C; Gawalt, Ellen S

    2016-08-01

    A new composite bioceramic consisting of calcium aluminum oxide (CaAlO) and hydroxyapatite (HA) was functionalized with the synthetic antimicrobial peptide Inverso-CysHHC10. CaAlO is a bioceramic that can be mold cast easily and quickly at room temperature. Improved functionality was previously achieved through surface reactions. Here, composites containing 0-5% HA (by mass) were prepared and the elastic modulus and modulus of rupture were mechanically similar to non-load bearing bone. The addition of hydroxyapatite resulted in increased osteoblast attachment (>180%) and proliferation (>140%) on all composites compared to 100% CaAlO. Antimicrobial peptide (AMP) immobilization was achieved using an interfacial alkene-thiol click reaction. The linked AMP persisted on the composite (>99.6% after 24h) and retained its activity against Escherichia coli based on N-phenylnaphthylamine uptake and bacterial turbidity tests. Overall, this simple scaffold system improves osteoblast activity and reduces bacterial activity. PMID:27157735

  3. The Influence of Peptide Modifications of Bioactive Glass on Human Mesenchymal Stem Cell Growth and Function

    NASA Astrophysics Data System (ADS)

    Ammar, Mohamed

    2011-12-01

    Bioactive glass is known for its potential as a bone scaffold due to its ability to stimulate osteogenesis and induce bone formation. Broadening this potential to include the differentiation of human mesenchymal stem cells (hMSCs) to bone cells will enhance the healing process in bone defects. The surface of bioactive glass made by the sol-gel technique with the composition of 70% SiO2-30% CaO (mol %) was grafted with 3 peptides sequences in different combinations from proteins (fibronectin BMP-2 and BMP-9) that are known to promote the adhesion, differentiation and osteogenesis process. The experiment was done in two forms, a 2D non-porous thin film and a 3D nano-macroporous structure. hMSCs were grown on the materials for a total of five weeks. The 2D materials were tested for the expression of 3 osteogenic markers (osteopontin, osteocalcin and osteonectin) through immunocytochemistry. The 3D forms were monitored for cell's adhesion, morphology, spreading and proliferation by scanning electron microscopy, in addition to proliferation assay and alkaline phosphatase activity measurement. Results showed that hMSCs poorly adhered to the 2D thin films, but the few cells survived showed enhanced expression of the osteogenic markers. On the 3D form, cells showed enhanced proliferation at week one and more survival of the cells on the materials grafted with the adhesion peptide for the successive weeks in comparison to the positive control samples. Enhanced alkaline phosphatase activity was also detected compared to the negative control samples but were still below the positive control samples. In conclusion, the peptide grafting could increase the effect of bioactive glass but more peptide combinations should be examined to improve the effects on the differentiation and osteogenic activity of the hMSCs.

  4. The Antitumor Peptide CIGB-552 Increases COMMD1 and Inhibits Growth of Human Lung Cancer Cells

    PubMed Central

    Fernández Massó, Julio R.; Oliva Argüelles, Brizaida; Tejeda, Yelaine; Astrada, Soledad; Garay, Hilda; Reyes, Osvaldo; Delgado-Roche, Livan; Bollati-Fogolín, Mariela; Vallespí, Maribel G.

    2013-01-01

    We have demonstrated that the peptide L-2 designed from an alanine scanning of the Limulus-derived LALF32-51 region is a potential candidate for the anticancer therapy and its cell-penetrating capacity is an associated useful property. By the modification in the primary structure of L-2, a second-generation peptide (CIGB-552) was developed. However, the molecular mechanism underlying its cytotoxic activity remains partially unknown. In this study, it was shown that CIGB-552 increases the levels of COMMD1, a protein involved in copper homeostasis, sodium transport, and the NF-κB signaling pathway. We found that CIGB-552 induces ubiquitination of RelA and inhibits the antiapoptotic activity regulated by NF-κB, whereas the knockdown of COMMD1 blocks this effect. We also found that CIGB-552 decreases the antioxidant capacity and induces the peroxidation of proteins and lipids in the tumor cells. Altogether, this study provides new insights into the mechanism of action of the peptide CIGB-552, which could be relevant in the design of future anticancer therapies. PMID:23401744

  5. Effects of maternal plasmid GHRH treatment on offspring growth

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To differentiate prenatal effects of plasmid growth hormone-releasing hormone (GHRH) treatment from maternal effects mediated by lactation on long-term growth of offspring, a cross-fostering study was designed. Pregnant sows (n = 12) were untreated (n = 6), or received either a Wt-GHRH (n = 2), or H...

  6. The Association between Newborn Regional Body Composition and Cord Blood Concentrations of C-Peptide and Insulin-Like Growth Factor I

    PubMed Central

    Carlsen, Emma M.; Renault, Kristina M.; Jensen, Rikke B.; Nørgaard, Kirsten; Jensen, Jens-Erik B.; Nilas, Lisbeth; Cortes, Dina; Michaelsen, Kim F.; Pryds, Ole

    2015-01-01

    Background Third trimester fetal growth is partially regulated by C-peptide and insulin-like growth factor I (IGF-I). Prenatal exposures including maternal obesity and high gestational weight gain as well as high birth weight have been linked to subsequent metabolic disease. We evaluated the associations between newborn regional body composition and cord blood levels of C-peptide and IGF-I. Methods We prospectively included obese and normal-weight mothers and their newborns; cord blood was collected and frozen. Analyses of C-peptide and IGF-I were performed simultaneously, after recruitment was completed. Newborn regional body composition was assessed with dual-energy X-ray absorptiometry scanning (DXA) within 48 hours of birth. Results Three hundred thirty-six term infants were eligible to participate in the study; of whom 174 (52%) infants had cord blood taken. Total, abdominal and arm and leg fat mass were positively associated with C-peptide (p < 0.001). Arm and leg fat mass was associated with IGF-I concentration: 28 g [95% confidence interval: 4, 53] per doubling of IGF-I. There was no association between total or abdominal fat mass and IGF-I. Fat-free mass was positively associated with both C-peptide (p < 0.001) and IGF-I (p = 0.004). Conclusion Peripheral fat tissue accumulation was associated with cord blood C-peptide and IGF-I. Total and abdominal fat masses were related to C-peptide but not to IGF-I. Thus, newborn adiposity is partially mediated through C-peptide and early linear growth is associated with IGF-I. PMID:26151559

  7. A Randomised Comparison Evaluating Changes in Bone Mineral Density in Advanced Prostate Cancer: Luteinising Hormone-releasing Hormone Agonists Versus Transdermal Oestradiol

    PubMed Central

    Langley, Ruth E.; Kynaston, Howard G.; Alhasso, Abdulla A.; Duong, Trinh; Paez, Edgar M.; Jovic, Gordana; Scrase, Christopher D.; Robertson, Andrew; Cafferty, Fay; Welland, Andrew; Carpenter, Robin; Honeyfield, Lesley; Abel, Richard L.; Stone, Michael; Parmar, Mahesh K.B.; Abel, Paul D.

    2016-01-01

    Background Luteinising hormone-releasing hormone agonists (LHRHa), used as androgen deprivation therapy (ADT) in prostate cancer (PCa) management, reduce serum oestradiol as well as testosterone, causing bone mineral density (BMD) loss. Transdermal oestradiol is a potential alternative to LHRHa. Objective To compare BMD change in men receiving either LHRHa or oestradiol patches (OP). Design, setting, and participants Men with locally advanced or metastatic PCa participating in the randomised UK Prostate Adenocarcinoma TransCutaneous Hormones (PATCH) trial (allocation ratio of 1:2 for LHRHa:OP, 2006–2011; 1:1, thereafter) were recruited into a BMD study (2006–2012). Dual-energy x-ray absorptiometry scans were performed at baseline, 1 yr, and 2 yr. Interventions LHRHa as per local practice, OP (FemSeven 100 μg/24 h patches). Outcome measurements and statistical analysis The primary outcome was 1-yr change in lumbar spine (LS) BMD from baseline compared between randomised arms using analysis of covariance. Results and limitations A total of 74 eligible men (LHRHa 28, OP 46) participated from seven centres. Baseline clinical characteristics and 3-mo castration rates (testosterone ≤1.7 nmol/l, LHRHa 96% [26 of 27], OP 96% [43 of 45]) were similar between arms. Mean 1-yr change in LS BMD was −0.021 g/cm3 for patients randomised to the LHRHa arm (mean percentage change −1.4%) and +0.069 g/cm3 for the OP arm (+6.0%; p < 0.001). Similar patterns were seen in hip and total body measurements. The largest difference between arms was at 2 yr for those remaining on allocated treatment only: LS BMD mean percentage change LHRHa −3.0% and OP +7.9% (p < 0.001). Conclusions Transdermal oestradiol as a single agent produces castration levels of testosterone while mitigating BMD loss. These early data provide further supporting evidence for the ongoing phase 3 trial. Patient summary This study found that prostate cancer patients treated with transdermal oestradiol

  8. Alternative splicing of pre-mRNA in cancer: focus on G protein-coupled peptide hormone receptors.

    PubMed

    Körner, Meike; Miller, Laurence J

    2009-08-01

    Through alternative splicing, multiple different transcripts can be generated from a single gene. Alternative splicing represents an important molecular mechanism of gene regulation in physiological processes such as developmental programming as well as in disease. In cancer, splicing is significantly altered. Tumors express a different collection of alternative spliceoforms than normal tissues. Many tumor-associated splice variants arise from genes with an established role in carcinogenesis or tumor progression, and their functions can be oncogenic. This raises the possibility that products of alternative splicing play a pathogenic role in cancer. Moreover, cancer-associated spliceoforms represent potential diagnostic biomarkers and therapeutic targets. G protein-coupled peptide hormone receptors provide a good illustration of alternative splicing in cancer. The wild-type forms of these receptors have long been known to be expressed in cancer and to modulate tumor cell functions. They are also recognized as attractive clinical targets. Recently, splice variants of these receptors have been increasingly identified in various types of cancer. In particular, alternative cholecystokinin type 2, secretin, and growth hormone-releasing hormone receptor spliceoforms are expressed in tumors. Peptide hormone receptor splice variants can fundamentally differ from their wild-type receptor counterparts in pharmacological and functional characteristics, in their distribution in normal and malignant tissues, and in their potential use for clinical applications. PMID:19574427

  9. Pathophysiological and diagnostic implications of cardiac biomarkers and antidiuretic hormone release in distinguishing immersion pulmonary edema from decompression sickness.

    PubMed

    Louge, Pierre; Coulange, Mathieu; Beneton, Frederic; Gempp, Emmanuel; Le Pennetier, Olivier; Algoud, Maxime; Dubourg, Lorene; Naibo, Pierre; Marlinge, Marion; Michelet, Pierre; Vairo, Donato; Kipson, Nathalie; Kerbaul, François; Jammes, Yves; Jones, Ian M; Steinberg, Jean-Guillaume; Ruf, Jean; Guieu, Régis; Boussuges, Alain; Fenouillet, Emmanuel

    2016-06-01

    Immersion pulmonary edema (IPE) is a misdiagnosed environmental illness caused by water immersion, cold, and exertion. IPE occurs typically during SCUBA diving, snorkeling, and swimming. IPE is sometimes associated with myocardial injury and/or loss of consciousness in water, which may be fatal. IPE is thought to involve hemodynamic and cardiovascular disturbances, but its pathophysiology remains largely unclear, which makes IPE prevention difficult. This observational study aimed to document IPE pathogenesis and improve diagnostic reliability, including distinguishing in some conditions IPE from decompression sickness (DCS), another diving-related disorder.Thirty-one patients (19 IPE, 12 DCS) treated at the Hyperbaric Medicine Department (Ste-Anne hospital, Toulon, France; July 2013-June 2014) were recruited into the study. Ten healthy divers were recruited as controls. We tested: (i) copeptin, a surrogate marker for antidiuretic hormone and a stress marker; (ii) ischemia-modified albumin, an ischemia/hypoxia marker; (iii) brain-natriuretic peptide (BNP), a marker of heart failure, and (iv) ultrasensitive-cardiac troponin-I (cTnI), a marker of myocardial ischemia.We found that copeptin and cardiac biomarkers were higher in IPE versus DCS and controls: (i) copeptin: 68% of IPE patients had a high level versus 25% of DCS patients (P < 0.05) (mean ± standard-deviation: IPE: 53 ± 61 pmol/L; DCS: 15 ± 17; controls: 6 ± 3; IPE versus DCS or controls: P < 0.05); (ii) ischemia-modified albumin: 68% of IPE patients had a high level versus 16% of DCS patients (P < 0.05) (IPE: 123 ± 25 arbitrary-units; DCS: 84 ± 25; controls: 94 ± 7; IPE versus DCS or controls: P < 0.05); (iii) BNP: 53% of IPE patients had a high level, DCS patients having normal values (P < 0.05) (IPE: 383 ± 394 ng/L; DCS: 37 ± 28; controls: 19 ± 15; IPE versus DCS or controls: P < 0.01); (iv) cTnI: 63% of IPE patients had a high

  10. Pathophysiological and diagnostic implications of cardiac biomarkers and antidiuretic hormone release in distinguishing immersion pulmonary edema from decompression sickness

    PubMed Central

    Louge, Pierre; Coulange, Mathieu; Beneton, Frederic; Gempp, Emmanuel; Le Pennetier, Olivier; Algoud, Maxime; Dubourg, Lorene; Naibo, Pierre; Marlinge, Marion; Michelet, Pierre; Vairo, Donato; Kipson, Nathalie; Kerbaul, François; Jammes, Yves; Jones, Ian M.; Steinberg, Jean-Guillaume; Ruf, Jean; Guieu, Régis; Boussuges, Alain; Fenouillet, Emmanuel

    2016-01-01

    Abstract Immersion pulmonary edema (IPE) is a misdiagnosed environmental illness caused by water immersion, cold, and exertion. IPE occurs typically during SCUBA diving, snorkeling, and swimming. IPE is sometimes associated with myocardial injury and/or loss of consciousness in water, which may be fatal. IPE is thought to involve hemodynamic and cardiovascular disturbances, but its pathophysiology remains largely unclear, which makes IPE prevention difficult. This observational study aimed to document IPE pathogenesis and improve diagnostic reliability, including distinguishing in some conditions IPE from decompression sickness (DCS), another diving-related disorder. Thirty-one patients (19 IPE, 12 DCS) treated at the Hyperbaric Medicine Department (Ste-Anne hospital, Toulon, France; July 2013–June 2014) were recruited into the study. Ten healthy divers were recruited as controls. We tested: (i) copeptin, a surrogate marker for antidiuretic hormone and a stress marker; (ii) ischemia-modified albumin, an ischemia/hypoxia marker; (iii) brain-natriuretic peptide (BNP), a marker of heart failure, and (iv) ultrasensitive-cardiac troponin-I (cTnI), a marker of myocardial ischemia. We found that copeptin and cardiac biomarkers were higher in IPE versus DCS and controls: (i) copeptin: 68% of IPE patients had a high level versus 25% of DCS patients (P < 0.05) (mean ± standard-deviation: IPE: 53 ± 61 pmol/L; DCS: 15 ± 17; controls: 6 ± 3; IPE versus DCS or controls: P < 0.05); (ii) ischemia-modified albumin: 68% of IPE patients had a high level versus 16% of DCS patients (P < 0.05) (IPE: 123 ± 25 arbitrary-units; DCS: 84 ± 25; controls: 94 ± 7; IPE versus DCS or controls: P < 0.05); (iii) BNP: 53% of IPE patients had a high level, DCS patients having normal values (P < 0.05) (IPE: 383 ± 394 ng/L; DCS: 37 ± 28; controls: 19 ± 15; IPE versus DCS or controls: P < 0.01); (iv) cTnI: 63% of IPE

  11. Elastin-derived peptides enhance melanoma growth in vivo by upregulating the activation of Mcol-A (MMP-1) collagenase

    PubMed Central

    Devy, J; Duca, L; Cantarelli, B; Joseph-Pietras, D; Scandolera, A; Rusciani, A; Parent, L; Thevenard, J; Pasco, S Brassart; Tarpin, M; Martiny, L; Debelle, L

    2010-01-01

    Background: Elastin peptides possess several biological activities and in vitro data suggest they could be involved in the early phase of melanoma growth. Methods: Using diverse in vitro and in vivo techniques (cell proliferation, invasion and migration assays, zymography, western blots, collagen degradation assay, reverse transcription PCR, melanoma allographs and immunohistochemistry), we analysed the effect of elastin-derived peptides (EDPs) on B16F1 melanoma growth and invasion, as well as on the proteolytic systems involved. Results: We found that EDPs dramatically promote in vivo tumour development of B16F1 melanoma, as well as their in vitro migration and invasion. The inhibition of serine proteases and matrix metalloproteinases (MMPs) activities, by aprotinin and galardin, respectively, demonstrated that these enzymes were involved in these processes. However, we found that EDPs did not increase urokinase-type plasminogen activator, tissue-type plasminogen activator or MMP-2 expression and/or activation, neither in vitro nor in vivo. Nevertheless, we observed a strong increase of pro-MMP-9 secretion in EDPs-treated tumours and, more importantly, an increase in the expression and activation of the murine counterpart of MMP-1, named murine collagenase-A (Mcol-A). Moreover, we show that plasminogen system inhibition decreases collagen degradation by this enzyme. Finally, the use of a specific blocking antibody against Mcol-A abolished EDP-induced B16F1 invasion in vitro, showing that this MMP was directly involved in this process. Conclusion: Our data show that in vivo, EDPs are involved in melanoma growth and invasion and reinforced the concept of elastin fragmentation as a predictive factor. PMID:20959825

  12. A proapoptotic peptide conjugated to penetratin selectively inhibits tumor cell growth.

    PubMed

    Alves, Isabel D; Carré, Manon; Montero, Marie-Pierre; Castano, Sabine; Lecomte, Sophie; Marquant, Rodrigue; Lecorché, Pascaline; Burlina, Fabienne; Schatz, Christophe; Sagan, Sandrine; Chassaing, Gérard; Braguer, Diane; Lavielle, Solange

    2014-08-01

    The peptide KLA (acetyl-(KLAKLAK)2-NH2), which is rather non toxic for eukaryotic cell lines, becomes active when coupled to the cell penetrating peptide, penetratin (Pen), by a disulfide bridge. Remarkably, the conjugate KLA-Pen is cytotoxic, at low micromolar concentrations, against a panel of seven human tumor cell lines of various tissue origins, including cells resistant to conventional chemotherapy agents but not to normal human cell lines. Live microscopy on cells possessing fluorescent labeled mitochondria shows that in tumor cells, KLA-Pen had a strong impact on mitochondria tubular organization instantly resulting in their aggregation, while the unconjugated KLA and pen peptides had no effect. But, mitochondria in various normal cells were not affected by KLA-Pen. The interaction with membrane models of KLA-Pen, KLA and penetratin were studied using dynamic light scattering, calorimetry, plasmon resonance, circular dichroism and ATR-FTIR to unveil the mode of action of the conjugate. To understand the selectivity of the conjugate towards tumor cell lines and its action on mitochondria, lipid model systems composed of zwitterionic lipids were used as mimics of normal cell membranes and anionic lipids as mimics of tumor cell and mitochondria membrane. A very distinct mode of interaction with the two model systems was observed. KLA-Pen may exert its deleterious and selective action on cancer cells by the formation of pores with an oblique membrane orientation and establishment of important hydrophobic interactions. These results suggest that KLA-Pen could be a lead compound for the design of cancer therapeutics. PMID:24796502

  13. Significant Type I and Type III Collagen Production from Human Periodontal Ligament Fibroblasts in 3D Peptide Scaffolds without Extra Growth Factors

    PubMed Central

    Kumada, Yoshiyuki; Zhang, Shuguang

    2010-01-01

    We here report the development of two peptide scaffolds designed for periodontal ligament fibroblasts. The scaffolds consist of one of the pure self-assembling peptide scaffolds RADA16 through direct coupling to short biologically active motifs. The motifs are 2-unit RGD binding sequence PRG (PRGDSGYRGDS) and laminin cell adhesion motif PDS (PDSGR). RGD and laminin have been previously shown to promote specific biological activities including periodontal ligament fibroblasts adhesion, proliferation and protein production. Compared to the pure RADA16 peptide scaffold, we here show that these designer peptide scaffolds significantly promote human periodontal ligament fibroblasts to proliferate and migrate into the scaffolds (for ∼300 µm/two weeks). Moreover these peptide scaffolds significantly stimulated periodontal ligament fibroblasts to produce extracellular matrix proteins without using extra additional growth factors. Immunofluorescent images clearly demonstrated that the peptide scaffolds were almost completely covered with type I and type III collagens which were main protein components of periodontal ligament. Our results suggest that these designer self-assembling peptide nanofiber scaffolds may be useful for promoting wound healing and especially periodontal ligament tissue regeneration. PMID:20421985

  14. Effects of ionizing radiation and pretreatment with (D-Leu6,des-Gly10) luteinizing hormone-releasing hormone ethylamide on developing rat ovarian follicles

    SciTech Connect

    Jarrell, J.; YoungLai, E.V.; McMahon, A.; Barr, R.; O'Connell, G.; Belbeck, L.

    1987-10-01

    To assess the effects of a gonadotropin-releasing hormone agonist, (D-Leu6,des-Gly10) luteinizing hormone-releasing hormone ethylamide, in ameliorating the damage caused by ionizing radiation, gonadotropin-releasing hormone agonist was administered to rats from day 22 to 37 of age in doses of 0.1, 0.4, and 1.0 microgram/day or vehicle and the rats were sacrificed on day 44 of age. There were no effects on estradiol, progesterone, luteinizing, or follicle-stimulating hormone, nor an effect on ovarian follicle numbers or development. In separate experiments, rats treated with gonadotropin-releasing hormone agonist in doses of 0.04, 0.1, 0.4, or 1.0 microgram/day were either irradiated or sham irradiated on day 30 and all groups sacrificed on day 44 of age. Irradiation produced a reduction in ovarian weight and an increase in ovarian follicular atresia. Pretreatment with the agonist prevented the reduction in ovarian weight and numbers of primordial and preantral follicles but not healthy or atretic antral follicles. Such putative radioprotection should be tested on actual reproductive performance.

  15. SIRT1 Regulates Thyroid-Stimulating Hormone Release by Enhancing PIP5Kγ Activity through Deacetylation of Specific Lysine Residues in Mammals

    PubMed Central

    Akieda-Asai, Sayaka; Zaima, Nobuhiro; Ikegami, Koji; Kahyo, Tomoaki; Yao, Ikuko; Hatanaka, Takahiro; Iemura, Shun-ichiro; Sugiyama, Rika; Yokozeki, Takeaki; Eishi, Yoshinobu; Koike, Morio; Ikeda, Kyoji; Chiba, Takuya; Yamaza, Haruyoshi; Shimokawa, Isao; Song, Si-Young; Matsuno, Akira; Mizutani, Akiko; Sawabe, Motoji; Chao, Moses V.; Tanaka, Masashi; Kanaho, Yasunori; Natsume, Tohru; Sugimura, Haruhiko; Date, Yukari; McBurney, Michael W.; Guarente, Leonard; Setou, Mitsutoshi

    2010-01-01

    Background SIRT1, a NAD-dependent deacetylase, has diverse roles in a variety of organs such as regulation of endocrine function and metabolism. However, it remains to be addressed how it regulates hormone release there. Methodology/Principal Findings Here, we report that SIRT1 is abundantly expressed in pituitary thyrotropes and regulates thyroid hormone secretion. Manipulation of SIRT1 level revealed that SIRT1 positively regulated the exocytosis of TSH-containing granules. Using LC/MS-based interactomics, phosphatidylinositol-4-phosphate 5-kinase (PIP5K)γ was identified as a SIRT1 binding partner and deacetylation substrate. SIRT1 deacetylated two specific lysine residues (K265/K268) in PIP5Kγ and enhanced PIP5Kγ enzyme activity. SIRT1-mediated TSH secretion was abolished by PIP5Kγ knockdown. SIRT1 knockdown decreased the levels of deacetylated PIP5Kγ, PI(4,5)P2, and reduced the secretion of TSH from pituitary cells. These results were also observed in SIRT1-knockout mice. Conclusions/Significance Our findings indicated that the control of TSH release by the SIRT1-PIP5Kγ pathway is important for regulating the metabolism of the whole body. PMID:20668706

  16. Stimulation of cholesterol side-chain cleavage by a luteinizing-hormone-releasing hormone (luliberin) agonist (ICI 118630) in rat Leydig cells.

    PubMed Central

    Sullivan, M H; Cooke, B A

    1983-01-01

    The action of a luliberin (luteinizing-hormone-releasing hormone) agonist (ICI 118630) and lutropin (luteinizing hormone) on the activity of the cytochrome P-450 cholesterol side-chain cleavage enzyme in rat Leydig cells has been investigated. This has been carried out by studying the metabolism of exogenous (22R)-22- and 25-hydroxycholesterol to testosterone. It was found that both hydroxycholesterols increased testosterone production to higher levels than achieved by lutropin alone. Addition of luliberin agonist but not lutropin was found to increase further the metabolism of the hydroxycholesterol to testosterone; this occurred in the presence of saturating and subsaturating levels of the hydroxycholesterols. This effect of luliberin agonist was potentiated in the presence of lutropin. The protein synthesis inhibitor, cycloheximide, inhibited the luliberin agonist-induced stimulation of the hydroxycholesterol metabolism. At low calcium levels (1.1 microM), testosterone production was increased by addition of (22R)-22-hydroxycholesterol but the luliberin agonist effect was negated. The calmodulin inhibitor trifluoperazine inhibited (22R)-22-hydroxycholesterol-stimulated steroidogenesis and negated the luliberin agonist effect. These results indicate that luliberin agonist specifically increases the synthesis of the cytochrome P-450 cholesterol side-chain cleavage enzyme in rat testis Leydig cells. PMID:6230077

  17. Luteinizing hormone-releasing hormone targeted poly(methyl vinyl ether maleic acid) nanoparticles for doxorubicin delivery to MCF-7 breast cancer cells.

    PubMed

    Varshosaz, Jaleh; Jahanian-Najafabadi, Ali; Ghazzavi, Jila

    2016-08-01

    The purpose of this study was to design a targeted anti-cancer drug delivery system for breast cancer. Therefore, doxorubicin (DOX) loaded poly(methyl vinyl ether maleic acid) nanoparticles (NPs) were prepared by ionic cross-linking method using Zn(2+) ions. To optimise the effect of DOX/polymer ratio, Zn/polymer ratio, and stirrer rate a full factorial design was used and their effects on particle size, zeta potential, loading efficiency (LE, %), and release efficiency in 72 h (RE72, %) were studied. Targeted NPs were prepared by chemical coating of tiptorelin/polyallylamin conjugate on the surface of NPs by using 1-ethyl-3-(3-dimethylaminopropyl) carboiimid HCl as cross-linking agent. Conjugation efficiency was measured by Bradford assay. Conjugated triptorelin and targeted NPs were studied by Fourier-transform infrared spectroscopy (FTIR). The cytotoxicity of DOX loaded in targeted NPs and non-targeted ones were studied on MCF-7 cells which overexpress luteinizing hormone-releasing hormone (LHRH) receptors and SKOV3 cells as negative LHRH receptors using Thiazolyl blue tetrazolium bromide assay. The best results obtained from NPs prepared by DOX/polymer ratio of 5%, Zn/polymer ratio of 50%, and stirrer rate of 960 rpm. FTIR spectrum confirmed successful conjugation of triptorelin to NPs. The conjugation efficiency was about 70%. The targeted NPs showed significantly less IC50 for MCF-7 cells compared to free DOX and non-targeted NPs. PMID:27463791

  18. Trp2 peptide vaccine adjuvanted with (R)-DOTAP inhibits tumor growth in an advanced melanoma model

    PubMed Central

    Vasievich, Elizabeth A.; Ramishetti, Srinivas; Zhang, Yuan; Huang, Leaf

    2012-01-01

    Previously we have shown cationic lipid (R)-DOTAP as the immunologically active enantiomer of the DOTAP racemic mixture, initiating complete tumor regression in an exogenous antigen model (murine cervical cancer model). Here, we investigate the use of (R)-DOTAP as an efficacious adjuvant delivering an endogenous antigen in an aggressive murine solid tumor melanoma model. (R)-DOTAP/Trp2 peptide complexes showed decreasing size and charge with increasing peptide concentration, taking a rod-shape at highest concentrations. The particles were stable for at 2 weeks at 4°C. A dose of 75nmol Trp2 (formulated in (R)-DOTAP) was able to show statistically significant tumor growth delay compared to lower doses of 5 and 25nmol which were no different than untreated tumors. (R)-DOTAP/Trp2 (75nmol) treated mice also showed increased T cell IFN-γ secretion after restimulation with Trp2, as well as CTL activity in vivo. This vaccination group also showed the highest population of functionally active tumor-infiltrating lymphocytes, indicated by IFN-γ secretion after restimulation with Trp2. Thus, (R)-DOTAP has shown the ability to break tolerance as an adjuvant. Its activity to enhance immunogenicity of other tumor associated antigens should be studied further. PMID:22142394

  19. PSP94 contributes to chemoresistance and its peptide derivative PCK3145 represses tumor growth in ovarian cancer.

    PubMed

    Yan, B-X; Ma, J-X; Zhang, J; Guo, Y; Riedel, H; Mueller, M D; Remick, S C; Yu, J J

    2014-11-01

    Tumor drug resistance remains a major challenge in the treatment of cancer. Here, we show that Prostatic secretory protein 94 (PSP94) levels are reduced in ovarian cancer patients with high levels of excision repair cross-complementing 1 (ERCC1), a marker for chemoresistance. We find that PSP94 is decreased in an ovarian cancer drug-resistant cell line, and plays an important role in the development of drug resistance in vitro. Our studies indicate that PSP94 can partially reverse drug resistance in mouse tumor models in vivo and that a PSP94 peptide derivative PCK3145 suppresses chemoresistant cancer cell and tumor growth in vitro and in vivo. Our investigation of the involved molecular mechanisms suggests that PSP94 may confer drug resistance by modulating the Lin28b/Let-7 signaling pathway. We introduce PSP94 and its peptide derivative PCK3145 as potential target to reverse chemoresistance in ovarian cancer and have begun to identify their relevant molecular targets in specific signaling pathways. PMID:24186202

  20. Self-assembling elastin-like peptides growth factor chimeric nanoparticles for the treatment of chronic wounds

    PubMed Central

    Koria, Piyush; Yagi, Hiroshi; Kitagawa, Yuko; Megeed, Zaki; Nahmias, Yaakov; Sheridan, Robert; Yarmush, Martin L.

    2011-01-01

    Chronic wounds are associated with poor epidermal and dermal remodeling. Previous work has shown the efficacy of keratinocyte growth factor (KGF) in reepithelialization and elastin in dermal wound healing. Here we demonstrate the fabrication of a fusion protein comprising of elastin-like peptides and KGF. This fusion protein retains the performance characteristics of KGF and elastin as evidenced by its enhancement of keratinocyte and fibroblast proliferation. It also preserved the characteristic elastin-like peptides inverse phase transitioning allowing the recombinant protein to be expressed in bacterial hosts (such as Escherichia coli) and purified rapidly and easily using inverse temperature cycling. The fusion protein self-assembled into nanoparticles at physiological temperatures. When applied to full thickness, wounds in Leprdb diabetic mice these particles enhanced reepithelialization and granulation, by 2- and 3-fold respectively, when compared to the controls. The data strongly suggests that these self-assembled nanoparticles may be beneficial in the treatment of chronic wounds resulting from diabetes or other underlying circulatory conditions. PMID:21193639

  1. Systemic transduction of p16INK4A antitumor peptide inhibits the growth of MBT-2 mouse bladder tumor cell line grafts.

    PubMed

    Shimazui, Toru; Yoshikawa, Kazuhiro; Miyazaki, Jun; Kojima, Takahiro; Inai, Hiromu; Ando, Satoshi; Uemura, Hirotsugu; Uchida, Kazuhiko; Nishiyama, Hiroyuki

    2013-02-01

    p16(INK4a) (p16), a key molecule in bladder tumor development, inhibits the activities of cyclin-dependent kinases (CDKs) and maintains the retinoblastoma protein (pRb) in its active hypophosphorylated state. Following the finding that the p16 antitumor peptide dramatically inhibits the growth of aggressive leukemia/lymphoma through the restoration of p16 function using the Wr-T peptide transporter system, in this study, we developed a systemic therapy using mouse‑p16 peptide (m‑p16) in subcutaneous p16‑null mouse bladder tumors. In vitro analysis showed that the growth of p16‑null bladder tumor cells and the hyperphosphorylation of their pRbs were inhibited by p16 transduction in a concentration‑dependent manner. In an animal model, p16‑null MBT‑2 cells were injected subcutaneously into KSN/SKC nude mice. The systemic delivery of the m‑p16 peptide using Wr‑T by cardiac injection significantly inhibited the growth of solid MBT‑2 tumors compared with the control phosphate‑buffered saline (PBS) injection. Histological examination by TUNEL staining revealed that apoptosis was increased and pRb phosphorylation was inhibited. Thus, the systemic peptide delivery of p16 restores the hypophosphorylation of pRb and may be a useful tool for the treatment of bladder tumors. PMID:23292502

  2. Potent sub-MIC effect of GSK1322322 and other peptide deformylase inhibitors on in vitro growth of Staphylococcus aureus.

    PubMed

    Butler, Deborah; Chen, Dongzhao; O'Dwyer, Karen; Lewandowski, Thomas; Aubart, Kelly; Zalacain, Magdalena

    2014-01-01

    Peptide deformylase (PDF), a clinically unexploited antibacterial target, plays an essential role in protein maturation. PDF inhibitors, therefore, represent a new antibiotic class with a unique mode of action that provides an alternative therapy for the treatment of infections caused by drug-resistant pathogens, including methicillin-resistant Staphylococcus aureus (MRSA). GSK1322322 is a novel PDF inhibitor that is in phase II clinical development for the treatment of lower respiratory tract and skin infections. We have discovered that PDF inhibitors can prevent S. aureus in vitro growth for up to 6 h at concentrations 8- to 32-fold below their MICs. This phenomenon seems specific to PDF inhibitors, as none of the antimicrobial agents with alternative mechanisms of action tested show such a potent and widespread effect. It also appears limited to S. aureus, as PDF inhibitors do not show such an inhibition of growth at sub-MIC levels in Streptococcus pneumoniae or Haemophilus influenzae. Analysis of the effect of GSK1322322 on the early growth of 100 randomly selected S. aureus strains showed that concentrations equal to or below 1/8× MIC inhibited growth of 91% of the strains tested for 6 h, while the corresponding amount of moxifloxacin or linezolid only affected the growth of 1% and 6% of strains, respectively. Furthermore, the sub-MIC effect demonstrated by GSK1322322 appears more substantial on those strains at the higher end of the MIC spectrum. These effects may impact the clinical efficacy of GSK1322322 in serious infections caused by multidrug-resistant S. aureus. PMID:24165188

  3. The application of antimicrobial peptides as growth and health promoters for swine.

    PubMed

    Xiao, Hao; Shao, Fangyuan; Wu, Miaomiao; Ren, Wenkai; Xiong, Xia; Tan, Bie; Yin, Yulong

    2015-01-01

    With the widespread ban on the use of antibiotics in swine feed, alternative measures need to be sought to maintain swine health and performance. Antimicrobial peptides (AMPs) are part of the nonspecific defense system and are natural antibiotics produced by plants, insects, mammalians, and micro-organisms as well as by chemical synthesis. Due to their broad microbicidal activity against various fungi, bacteria and enveloped viruses, AMPs are a potential alternative to conventional antibiotics for use in swine production. This review focuses on the structure and mechanism of action of AMPs, as well as their effects on performance, immune function and intestinal health in pigs. The aim is to provide support for the application of AMPs as feed additives replacing antibiotics in swine nutrition. PMID:26019864

  4. Inhibitory effects of small molecular peptides from Spirulina (Arthrospira) platensis on cancer cell growth.

    PubMed

    Wang, Zhujun; Zhang, Xuewu

    2016-02-01

    In this study, the whole proteins of Spirulina (Arthrospira) platensis were extracted, hydrolysis with three proteases (trypsin, alcalase and papain) was performed, and gel filtration chromatography was employed to separate hydrolysates. Totally, 15 polypeptides were isolated, which showed anti-proliferation activities on five cancer cells (HepG-2, MCF-7, SGC-7901, A549 and HT-29), with the IC50 values between <31.25 and 336.57 μg mL(-1). Moreover, a new peptide YGFVMPRSGLWFR was identified from papain-digested hydrolysates. It also exhibited inhibitory activities on cancer cells, and the best activity was observed on A549 cancer cells (IC50 values 104.05 μg mL(-1)). In other words, these polypeptides exhibited anti-proliferation activities on cancer cells, and low toxicity or stimulatory activity on normal cells, suggesting that they are promising ingredients in food and pharmaceutical applications. PMID:26584028

  5. A KDR-binding peptide (ST100,059) can block angiogenesis, melanoma tumor growth and metastasis in vitro and in vivo.

    PubMed

    Rastelli, Luca; Valentino, Maria Luisa; Minderman, Melissa Corso; Landin, Judith; Malyankar, Uriel M; Lescoe, Mary K; Kitson, Richard; Brunson, Kenneth; Souan, Lina; Forenza, Salvatore; Goldfarb, Ronald H; Rabbani, Shafaat A

    2011-08-01

    A major goal of treatment strategies for cancer is the development of agents which can block primary tumor growth and development as well as the progression of tumor metastasis without any treatment associated side effects. Using mini peptide display (MPD) technology, we generated peptides that can bind to the human vascular endothelial growth factor (VEGF) receptor KDR. These peptides were evaluated for their ability to block angiogenesis, tumor growth and metastasis in vitro and in vivo. A D-amino acid peptide with high serum stability (ST100,059) was found to have the most potent activity in vitro as indicated by inhibition of VEGF stimulation of endothelial cells. It was also found to be the most active of the series in blocking VEGF-mediated activity in vivo, as measured in Matrigel-filled angioreactors implanted in mice. ST100,059 blocks VEGF-induced MAPK phosphorylation, as well as inhibits VEGF-induced changes in gene expression in HUVEC cells. In in vivo studies, treatment of female C57BL/6 mice inoculated with B16 mouse melanoma cells with ST100,059 resulted in a dose-dependent decrease in tumor volume and lung metastasis as compared to control groups of animals receiving vehicle alone. These studies demonstrate that by using MPD, peptides can be identified with enhanced affinity relative to those discovered using phage display. Based on these studies we have identified one such peptide ST100,059 which can effectively block tumor growth and metastasis due to its anti-angiogenic effects and ability to block intracellular signaling pathways involved in tumor progression. PMID:21567086

  6. The role of RFamide-related peptide 3 (RFRP3) in regulation of the neuroendocrine reproductive and growth axes of the boar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    RFamide-related peptide 3 (RFRP3) has been implicated in the regulation of the male reproductive and growth axes. However, responsiveness to RFRP3 appears to be dependent upon sex, specie, physiological status, and developmental stage. Our objective was to evaluate the effects of RFRP3 on circulatin...

  7. Total Androgen Blockade Versus a Luteinizing Hormone-Releasing Hormone Agonist Alone in Men With High-Risk Prostate Cancer Treated With Radiotherapy

    SciTech Connect

    Nanda, Akash; Moran, Brian J.; Braccioforte, Michelle H.; Dosoretz, Daniel; Salenius, Sharon; Katin, Michael; Ross, Rudi; D'Amico, Anthony V.

    2010-04-15

    Purpose: To assess whether short-course total androgen blockade vs. a luteinizing hormone-releasing hormone (LHRH) agonist alone affects the risk of prostate cancer-specific mortality (PCSM) in men with localized but high-risk disease treated with radiotherapy. Methods and Materials: The study cohort comprised 628 men with T1-T4, N0, M0 prostate cancer with high-risk disease (prostate-specific antigen level >20 ng/mL, Gleason score >=8, or clinical category >=T3) treated with 45 Gy of external beam radiotherapy followed by a brachytherapy boost in addition to receiving a median of 4.3 (interquartile range [IQR], 3.6-6.4) months of hormonal blockade with an LHRH agonist plus an antiandrogen or monotherapy with an LHRH agonist. Fine and Gray's multivariable regression analysis was used to determine whether combination androgen suppression therapy (AST) vs. monotherapy affected the risk of PCSM, adjusting for treatment year, duration of AST, age, and known prognostic factors. Results: After a median follow-up of 4.9 (IQR, 3.5-6.5) years, men receiving combination AST had a lower risk of PCSM than those treated with monotherapy (adjusted hazard ratio [AHR], 0.18; 95% confidence interval [CI], 0.04-0.90; p = 0.04). An increasing prostate-specific antigen level (AHR, 2.70; 95% CI, 1.64-4.45; p < 0.001) and clinical category T3/4 disease (AHR, 29.6; 95% CI, 2.88-303.5; p = 0.004) were also associated with an increased risk of PCSM. Conclusions: In men with localized but high-risk prostate cancer treated with external beam radiotherapy and brachytherapy, short-course AST with an LHRH agonist plus an antiandrogen is associated with a decreased risk of PCSM when compared with monotherapy with an LHRH agonist.

  8. A specific aptamer-cell penetrating peptides complex delivered siRNA efficiently and suppressed prostate tumor growth in vivo.

    PubMed

    Diao, Yanjun; Liu, Jiayun; Ma, Yueyun; Su, Mingquan; Zhang, Hongyi; Hao, Xiaoke

    2016-05-01

    Specific and efficient delivery of siRNA into intended tumor cells remains as a challenge, even though RNAi has been exploited as a new strategy for prostate cancer therapy. This work aims to address both specificity and efficiency of SURVIVIN-siRNA delivery by constructing a therapeutic complex using combinatorial strategies. A fusion protein STD was first expressed to serve as a backbone, consisting of streptavidin, a cell-penetrating peptide called Trans-Activator of Transcription (TAT) and a double-stranded RNA binding domain. A biotinylated Prostate Specific Membrane Antigen (PSMA) specific aptamer A10 and SURVIVIN-siRNA were then linked to STD protein to form the therapeutic complex. This complex could specifically targeted PSMA(+) tumor cells. Compared to lipofectamine and A10-siRNA chimera, it demonstrated higher efficiency in delivering siRNA into target cells by 19.2% and 59.9%, and increased apoptosis by 16.8% and 26.1% respectively. Upon systemic administration, this complex also showed significant efficacy in suppressing tumor growth in athymic mice (p <0.001). We conclude that this therapeutic complex could specifically and efficiently deliver SURVIVIN-siRNA to target cells and suppressed tumor growth in vivo, which indicates its potential to be used as a new strategy in prostate cancer therapy. PMID:26954374

  9. Platelet-released growth factors induce the antimicrobial peptide human beta-defensin-2 in primary keratinocytes.

    PubMed

    Bayer, Andreas; Lammel, Justus; Rademacher, Franziska; Groß, Justus; Siggelkow, Markus; Lippross, Sebastian; Klüter, Tim; Varoga, Deike; Tohidnezhad, Mersedeh; Pufe, Thomas; Cremer, Jochen; Gläser, Regine; Harder, Jürgen

    2016-06-01

    Platelet-released growth factors (PRGF) and its related clinically used formulations [e.g. Vivostat platelet-rich fibrin (PRF(®) )] are thrombocyte concentrate lysates that support healing of chronic, hard-to-heal and infected wounds. Human beta-defensin-2 (hBD-2) is an antimicrobial peptide expressed in human keratinocytes exhibiting potent antimicrobial activity against wound-related bacteria. In this study, we analysed the influence of PRGF on hBD-2 expression in human primary keratinocytes and the influence of Vivostat PRF(®) on hBD-2 expression in experimentally generated skin wounds in vivo. Treatment of primary keratinocytes with PRGF caused a significant increase in hBD-2 gene and protein expressions in a concentration- and time-dependent manner. The use of blocking antibodies revealed that the PRGF-mediated hBD-2 induction was partially mediated by the epidermal growth factor receptor and the interleukin-6 receptor (IL-6R). Luciferase gene reporter assays indicated that the hBD-2 induction through PRGF required activation of the transcription factor activator protein 1 (AP-1), but not of NF-kappaB. In concordance with these cell culture data, Vivostat PRF(®) induced hBD-2 expression when applied to experimentally generated skin wounds. Together, our results indicate that the induction of hBD-2 by thrombocyte concentrate lysates can contribute to the observed beneficial effects in the treatment of chronic and infected wounds. PMID:26843467

  10. Efficacy of a Complex of 5-Aminolevulinic Acid and Glycyl-Histidyl-Lysine Peptide on Hair Growth

    PubMed Central

    Sim, Hyun Bo; Jang, Yong Hyun; Lee, Seok-Jong; Kim, Do Won; Yim, Soon-Ho

    2016-01-01

    Background Pattern hair loss is a very common problem. Although effective therapeutics for the treatment of pattern hair loss have been used, novel therapeutic modalities are still required to enhance hair growth. Objective We investigated the efficacy and safety of a complex (ALAVAX) of 5-aminolevulinic acid (5-ALA) and glycyl-histidyl-lysine (GHK) peptide for the treatment of pattern hair loss. Methods Forty-five patients with male pattern hair loss were treated with ALAVAX 100 mg/ml (group A), ALAVAX 50 mg/ml (group B) or placebo (group C) once a day for 6 months. Total hair count, hair length, hair thickness, patient's assessment and adverse events were evaluated at month 1, 3, and 6. Results An increase in hair count for 6 months was 52.6 (p<0.05) in group A, 71.5 (p<0.05) in group B, and 9.6 in group C. The ratio of changes in hair count between group B (2.38) and group C (1.21) at 6 months showed a statistically significant difference (p<0.05). The proportion above good satisfaction was higher in group A (26.7%) than in the other groups (group B: 14.3%, group C: 7.1%). There was no statistically significant difference in hair length and hair thickness among 3 groups at 6 months. There was no adverse event in 3 groups. Conclusion Our study showed that a complex of 5-ALA and GHK peptide may be considered as one of the complementary agents for the treatment of male pattern hair loss. PMID:27489425

  11. Distribution, characterization, and growth hormone-releasing activity of pituitary adenylate cyclase-activating polypeptide in the European eel, Anguilla anguilla.

    PubMed

    Montero, M; Yon, L; Rousseau, K; Arimura, A; Fournier, A; Dufour, S; Vaudry, H

    1998-10-01

    The complementary DNA encoding pituitary adenylate cyclase-activating polypeptide (PACAP) has been cloned from two species of teleost fishes, the Sockeye salmon and the Thai catfish, and the amino acid sequence of PACAP has been determined in another teleost, the stargazer. However, to date, the detailed distribution of PACAP immunoreactivity has never been investigated in the fish brain. In the present study, we have determined the localization of PACAP-immunoreactive neurons in the central nervous system of a primitive teleost fish, the European eel Anguilla anguilla, using an antiserum raised against PACAP27. PACAP-positive perikarya were exclusively observed in the diencephalon, i.e. in the preoptic nucleus of the hypothalamus and in the dorsal and ventral nuclei of the thalamus. PACAP-immunoreactive fibers were detected in various areas of the brain, notably in the ventral telencephalon, the diencephalon, the mesencephalon, the cerebellar valvula, and the medulla oblongata. In addition, a dense accumulation of PACAP-containing nerve terminals was found in the pars distalis of the pituitary. The PACAP-like immunoreactivity contained in the eel brain was characterized by HPLC analysis combined with RIA quantification. The major form of PACAP-immunoreactive material coeluted with mammalian PACAP38. Molecular cloning of the PACAP precursor has previously shown that in fish, PACAP and GH-releasing hormone (GHRH) originate from the same precursor. We have thus investigated the effects of PACAP and GHRH on GH secretion from eel pituitary cells in primary culture. Dose-response experiments revealed that PACAP27 and PACAP38 possessed the same efficacy, but PACAP38 was 12 times more potent than PACAP27 in stimulating GH release (ED50 = 4.3 x 10(-10) and 3.5 x 10(-9) M, respectively). In contrast, GHRH, even at a high concentration (10(-6) M), had no effect on GH release. Taken together, these data indicate that in the eel, PACAP may play a significant role in the regulation of somatotrope cells: 1) PACAP-immunoreactive neurons are exclusively located in the diencephalon and send numerous projections in the pars distalis; and 2) PACAP, but not GHRH, dose dependently stimulates GH secretion from cultured eel pituitary cells. PMID:9751513

  12. A new peptide-based urethane polymer: synthesis, biodegradation, and potential to support cell growth in vitro

    PubMed Central

    Zhang, Jian Ying; Beckman, Eric J.; Piesco, Nicholas P.; Agarwal, Sudha

    2016-01-01

    A novel non-toxic biodegradable lysine-di-isocyanate (LDI)-based urethane polymer was developed for use in tissue engineering applications. This matrix was synthesized with highly purified LDI made from the lysine diethylester. The ethyl ester of LDI was polymerized with glycerol to form a prepolymer. LDI–glycerol prepolymer when reacted with water foamed with the liberation of CO2 to provide a pliable spongy urethane polymer. The LDI–glycerol matrix degraded in aqueous solutions at 100, 37, 22, and 4°C at a rate of 27.7, 1.8, 0.8, and 0.1 mM per 10 days, respectively. Its thermal stability in water allowed its sterilization by autoclaving. The degradation of the LDI–glycerol polymer yielded lysine, ethanol, and glycerol as breakdown products. The degradation products of LDI–glycerol polymer did not significantly affect the pH of the solution. The glass transition temperature (Tg) of this polymer was found to be 103.4°C. The physical properties of the polymer network were found to be adequate to support the cell growth in vitro, as evidenced by the fact that rabbit bone marrow stromal cells (BMSC) attached to the polymer matrix and remained viable on its surface. Culture of BMSC on LDI–glycerol matrix for long durations resulted in the formation of multilayered confluent cultures, a characteristic typical of bone cells. Furthermore, cells grown on LDI–glycerol matrix did not differ phenotypically from the cells grown on the tissue culture polystyrene plates as assessed by the cell growth, and expression of mRNA for collagen type I, and transforming growth factor-β1 (TGF-β1). The observations suggest that biodegradable peptide-based urethane polymers can be synthesized which may pave their way for possible use in tissue engineering applications. PMID:10811306

  13. Vasoactive peptides upregulate mRNA expression and secretion of vascular endothelial growth factor in human airway smooth muscle cells.

    PubMed

    Alagappan, Vijay K T; Willems-Widyastuti, Anna; Seynhaeve, Ann L B; Garrelds, Ingrid M; ten Hagen, Timo L M; Saxena, Pramod R; Sharma, Hari S

    2007-01-01

    Airway remodeling and associated angiogenesis are documented features of asthma, of which the molecular mechanisms are not fully understood. Angiotensin (ANG)II and endothelin (ET)-1 are potent vasoconstricting circulatory hormones implicated in asthma. We investigated the effects of ANG II and ET-1 on human airway smooth muscle (ASM) cells proliferation and growth and examined the mRNA expression and release of the angiogenic peptide, vascular endothelial growth factor (VEGF). Serum deprived (48 h) human ASM cells were incubated with ANG II (100 nM) or ET-1 (10 nM) for 30 min, 1, 2, 4, 8, 16, and 24 h and the endogenous synthesis of VEGF was examined in relation to control cells receiving serum free culture medium. ET-1 induced time dependent DNA biosynthesis as determined by [3H]-thymidine incorporation assay. Using northern blot hybridization, we detected two mRNA species of 3.9 and 1.7 kb encoding VEGF in the cultured smooth muscle cells. Both ANG II and ET-1 induced the mRNA expression (two- to threefold) and secretion (1.8- to 2.8-fold) of VEGF reaching maximal levels between 4-8 h of incubation. Induced expression and release of VEGF declined after 8 h of ANG II incubation while levels remained elevated in the case of ET-1. The conditioned medium derived from ET-1-treated ASM cells induced [3H]-thymidine incorporation and cell number in porcine pulmonary artery endothelial as well as human umbilical vein endothelial cells. Moreover, the VEGF tyrosine kinase receptor inhibitor blocked the conditioned medium induced mitogenesis in endothelial cells. Our results suggest a potential role for ANG II and ET-1 in ASM cell growth and upregulation of VEGF that may participate in endothelial cell proliferation via paracrine mechanisms and thus causing pathological angiogenesis and vascular remodelling seen during asthma. PMID:17406064

  14. The p27 Pathway Modulates the Regulation of Skeletal Growth and Osteoblastic Bone Formation by Parathyroid Hormone-Related Peptide.

    PubMed

    Zhu, Min; Zhang, Jing; Dong, Zhan; Zhang, Ying; Wang, Rong; Karaplis, Andrew; Goltzman, David; Miao, Dengshun

    2015-11-01

    Parathyroid hormone-related peptide (PTHrP) 1-84 knock-in mice (Pthrp KI) develop skeletal growth retardation and defective osteoblastic bone formation. To further examine the mechanisms underlying this phenotype, microarray analyses of differential gene expression profiles were performed in long bone extracts from Pthrp KI mice and their wild-type (WT) littermates. We found that the expression levels of p27, p16, and p53 were significantly upregulated in Pthrp KI mice relative to WT littermates. To determine whether p27 was involved in the regulation by PTHrP of skeletal growth and development in vivo, we generated compound mutant mice, which were homozygous for both p27 deletion and the Pthrp KI mutation (p27(-/-) Pthrp KI). We then compared p27(-/-) Pthrp KI mice with p27(-/-), Pthrp KI, and WT littermates. Deletion of p27 in Pthrp KI mice resulted in a longer lifespan, increased body weight, and improvement in skeletal growth. At 2 weeks of age, skeletal parameters, including length of long bones, size of epiphyses, numbers of proliferating cell nuclear antigen (PCNA)-positive chondrocytes, bone mineral density, trabecular bone volume, osteoblast numbers, and alkaline phosphatase (ALP)-, type I collagen-, and osteocalcin-positive bone areas were increased in p27(-/-) mice and reduced in both Pthrp KI and p27(-/-) Pthrp KI mice compared with WT mice; however, these parameters were increased in p27(-/-) Pthrp KI mice compared with Pthrp KI mice. As well, protein expression levels of PTHR, IGF-1, and Bmi-1, and the numbers of total colony-forming unit fibroblastic (CFU-f) and ALP-positive CFU-f were similarly increased in p27(-/-) Pthrp KI mice compared with Pthrp KI mice. Our results demonstrate that deletion of p27 in Pthrp KI mice can partially rescue defects in skeletal growth and osteoblastic bone formation by enhancing endochondral bone formation and osteogenesis. These studies, therefore, indicate that the p27 pathway may function downstream in the action

  15. Effects of small peptides, probiotics, prebiotics, and synbiotics on growth performance, digestive enzymes, and oxidative stress in orange-spotted grouper, Epinephelus coioides, juveniles reared in artificial seawater

    NASA Astrophysics Data System (ADS)

    Wang, Tao; Cheng, Yongzhou; Chen, Xiaoyan; Liu, Zhaopu; Long, Xiaohua

    2016-04-01

    Aquaculture production efficiency may increase by using feed additives. This study investigated the effects of diff erent dietary additives [w/w: 2% small peptides, 0.01% probiotics (Bacillus licheniformis) and 0.2% prebiotics (inulin)] on growth performance, digestive enzyme activities, and oxidative stress in juvenile Epinephelus coioides reared in artificial seawater of two salt concentrations (13.5 vs. 28.5). Weight gain rate was significantly higher in fish fed the diet supplemented with small peptides, B. licheniformis, inulin, or synbiotics than that in fish fed the basal diet; the greatest weight gain rate was found in fish fed the small peptide treatment [56.0% higher than basal diet]. Higher feed efficiency was detected in fish fed the diet supplemented with small peptides than that of fish in the other dietary treatments. Total protease activity in the stomach and intestines was highest in fish fed the small peptide-treated diet, whereas lipase activity was highest in those fed synbiotics (combination of Bacillus licheniformis and inulin) than that in fish fed the other treatments. Antioxidant enzyme (total superoxide dismutase and catalase) activities and hepatic malondialdehyde content were higher in fish receiving the dietary supplements and maintained in artificial seawater containing 13.5 salinity compared with those in the control (28.5). Hepatic catalase activity in grouper fed the diets with small peptides or synbiotics decreased significantly compared with that in control fish. Overall, the three types of additives improved growth rate of juvenile grouper and digestive enzymes activities to varying degrees but did not effectively improve antioxidant capacity under low-salinity stress conditions.

  16. MATERNAL GHRH PLASMID ADMINISTRATION CHANGES PITUITARY CELL LINEAGE AND IMPROVES PROGENY GROWTH OF PIGS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous studies from our laboratory have demonstrated that administration of a myogenic plasmid that encodes a protease-resistant growth hormone-releasing hormone (HV-GHRH) to pregnant rat dams augmented long-term growth in first-generation progeny. In the present study, gilts were injected intra-m...

  17. The Anti-angiogenic Peptide, Loop 6, Binds Insulin-like Growth Factor-1 Receptor*

    PubMed Central

    Fernandez, Cecilia A.; Roy, Roopali; Lee, Sunyoung; Yang, Jiang; Panigrahy, Dipak; Van Vliet, Krystyn J.; Moses, Marsha A.

    2010-01-01

    Tissue inhibitors of metalloproteinases (TIMPs), the endogenous inhibitors of matrix metalloproteinases, have been shown to possess biological functions that are independent of their ability to inhibit matrix metalloproteinases. We have previously shown that the C-terminal domain of TIMP-2 and, in particular, Loop 6 inhibit capillary endothelial cell proliferation and angiogenesis both in vitro and in vivo. To elucidate the mechanism by which Loop 6 inhibits angiogenesis, we sought to determine whether its biological effects were the result of a known TIMP-2 protein-protein interaction or of a receptor-mediated event. In this study, we identify insulin-like growth factor-1 receptor as a binding partner of Loop 6/TIMP-2 and characterize this interaction on the endothelial cell surface and the consequences of this interaction on downstream receptor signaling. PMID:20940305

  18. Quantitative measurement of epidermal growth factor receptor-mitogen-activated protein kinase signal transduction using a nine-plex, peptide-based immunoassay.

    PubMed

    Rauh-Adelmann, Christine; Moskow, John M; Graham, James R; Yen, Lucy G; Boucher, Jeffrey I; Murphy, Cheryl E; Nadler, Timothy K; Gordon, Neal F; Radding, Jeffrey A

    2008-04-15

    Aberrant epidermal growth factor receptor (EGFR, ErbB1) signaling is implicated in cell transformation, motility, and invasion in a variety of cell types, and EGFR is the target of several anticancer drugs. However, the kinetics of EGFR signaling and the individual contributions of site-specific phosphorylation events remain largely unknown. A peptide-based, multiplex immunoassay approach was developed to simultaneously measure both total and phosphorylated protein in a single sample. The approach involves the proteolytic digestion of proteins prior to the isolation and quantitation of site-specific phosphorylation events within an individual protein. Quantitation of phosphorylated and total proteins, in picomolar to nanomolar concentrations, were interpolated from standard curves generated with synthetic peptides that correspond to the peptide targets used in the immunoassays. In this study, a bead-based, nine-plex immunoassay measuring total and phosphorylated protein was constructed to measure temporal, site-specific phosphorylation of key members of the EGFR pathway (ErbB1 receptor, MEK1, MEK2, ERK1, and ERK2) in A431 cells stimulated with epidermal growth factor. The effect of MEK inhibition on this pathway was determined using a known MEK kinase inhibitor, SL327. The results reported herein are the first quantitative measurements of site-specific phosphorylation events and total proteins in a single sample, at the same time representing a new paradigm for standardized protein and phosphorylation analysis using multiplexed, peptide-based, sandwich immunoassays. PMID:18275835

  19. The antibacterial peptide from Bombyx mori cecropinXJ induced growth arrest and apoptosis in human hepatocellular carcinoma cells

    PubMed Central

    XIA, LIJIE; WU, YANLING; MA, JI; YANG, JIANHUA; ZHANG, FUCHUN

    2016-01-01

    CecropinXJ is a cationic antimicrobial peptide originally isolated from the larvae of Bombyx mori. The anticancer effect of cecropinXJ has been reported in various tumor cells, including leukemia, gastric and esophageal cancer cells. However, the activity of cecropinXJ on hepatocellular carcinoma (HCC) and its underlying mechanism have not been investigated to date. Therefore, the present study investigated the efficacy and associated mechanism of cecropinXJ in Huh-7 cells. Flow cytometric analysis was performed to determine the presence of cell cycle arrested and apoptotic cells. CecropinXJ significantly inhibited the growth of Huh-7 cells in a dose- and time-dependent manner. CecropinXJ treatment for 24 h induced S cell cycle arrest and apoptosis, in addition to loss of the mitochondrial membrane potential, in hepatoma cells. CecropinXJ induced HCC cell apoptosis by activating caspase-3 and poly(ADP-ribose) polymerase. Furthermore, cecropinXJ downregulated the expression of B-cell lymphoma 2 (Bcl-2), while upregulated the expression of Bcl-2-associated death promoter and Bcl-2-associated X protein. In conclusion, the results of the present study suggest that cecropinXJ may be an active anti-HCC agent and provide novel insights into the mechanism of cecropinXJ. PMID:27347099

  20. A membrane penetrating peptide aptamer inhibits STAT3 function and suppresses the growth of STAT3 addicted tumor cells

    PubMed Central

    Borghouts, Corina; Delis, Natalia; Brill, Boris; Weiss, Astrid; Mack, Laura; Lucks, Peter; Groner, Bernd

    2012-01-01

    Cancer cells are characterized by the aberrant activation of signaling pathways governing proliferation, survival, angiogenesis, migration and immune evasion. These processes are partially regulated by the transcription factor STAT3. This factor is inappropriately activated in diverse tumor types. Since tumor cells can become dependent on its persistent activation, STAT3 is a favorable drug target. Here, we describe the functional characterization of the recombinant STAT3 inhibitor, rS3-PA. This inhibitor is based on a 20 amino acid peptide which specifically interacts with the dimerization domain of STAT3. It is integrated into a thioredoxin scaffold and fused to a protein transduction domain. Protein gel blot and immunofluorescence analyses showed that rS3-PA is efficiently taken up by cells via an endocytosis independent mechanism. Intracellularly, it reduces the phosphorylation of STAT3 and enhances its degradation. This leads to the downregulation of STAT3 target gene expression on the mRNA and protein levels. Subsequently, tumor cell proliferation, survival and migration and the induction of angiogenesis are inhibited. In contrast, normal cells remain unaffected. Systemic administration of rS3-PA at doses of 7.5 mg/kg reduced P-STAT3 levels and significantly inhibited tumor growth up to 35% in a glioblastoma xenograft mouse model. PMID:24058750

  1. Effect of priming injections of luteinizing hormone-releasing hormone on spermiation and ovulation in Gϋnther's Toadlet, Pseudophryne guentheri

    PubMed Central

    2011-01-01

    Background In the majority of vertebrates, gametogenesis and gamete-release depend on the pulsatile secretion of luteinizing hormone-releasing hormone (LHRH) from the hypothalamus. Studies attempting to artificially stimulate ovulation and spermiation may benefit from mimicking the naturally episodic secretion of LHRH by administering priming injections of a synthetic analogue (LHRHa). This study investigated the impact of low-dose priming injections of LHRHa on gamete-release in the Australian toadlet Pseudophryne guentheri. Methods Toadlets were administered a single dose of two micrograms per. gram LHRHa without a priming injection (no priming), or preceded by one (one priming) or two (two priming) injections of 0.4 micrograms per. gram LHRHa. Spermiation responses were evaluated at 3, 7 and 12 hrs post hormone administration (PA), and sperm number and viability were quantified using fluorescent microscopy. Oocyte yields were evaluated by stripping females at 10-11 hrs PA. A sub-sample of twenty eggs per female was then fertilised (with sperm obtained from testis macerates) and fertilisation success determined. Results No priming induced the release of the highest number of spermatozoa, with a step-wise decrease in the number of spermatozoa released in the one and two priming treatments respectively. Peak sperm-release occurred at 12 hrs PA for all priming treatments and there was no significant difference in sperm viability. Females in the control treatment failed to release oocytes, while those administered an ovulatory dose without priming exhibited a poor ovulatory response. The remaining two priming treatments (one and two priming) successfully induced 100% of females to expel an entire clutch. Oocytes obtained from the no, or two priming treatments all failed to fertilise, however oocytes obtained from the one priming treatment displayed an average fertilisation success of 97%. Conclusion Spermiation was most effectively induced in male P. guentheri by

  2. Lead (Pb) alters the norepinephrine-induced secretion of luteinizing hormone releasing hormone from the median eminence of adult male rats in vitro

    SciTech Connect

    Bratton, G.R.; Hiney, J.K.; Dees, W.L. )

    1994-01-01

    In the present study, the authors evaluated the in vitro effects of lead (Pb) on basal and stimulated luteinizing hormone releasing hormone (LHRH) and Prostaglandin E[sub 2] (PGE[sub 2]) secretion. Median eminences (ME) were removed from brains of adult male rats and preincubated for 15 minutes in Krebs-Ringer bicarbonate glucose buffer in an atmosphere of 95% O[sub 2]-5% CO[sub 2]. These media were discarded and all MEs were subjected to one of the following experiments. In Experiment 1, all MEs were incubated for 30 minutes in medium only. These media were collected and replaced with medium only (controls) or with medium containing Pb doses ranging from 5 to 20 [mu]M. After this 60-minute incubation, media were collected, then replaced with new medium containing 60 [mu]M norepinephrine (NE), or NE plus each dose of Pb, then incubated for a final 30-minute period. Experiment 2 was conducted as above, except PGE[sub 2] (2.8 [mu]M) replaced the NE. In both experiments, the amounts of LHRH released was measured by RIA. In experiment 3, NE was again used for the challenge; however, this time, the amount of PGE[sub 2] released was measured by RIA. Results indicate that Pb did not alter basal LHRH release, but compared with controls, significantly blocked NE-induced LHRH release in a dose-related manner. Conversely, Pb had no effect on the PGE[sub 2]-induced release of LHRH. Additionally, Pb did not alter basal PGE[sub 2] release; however, it significantly blocked the NE-induced release of PGE[sub 2]. Since NE-induced LHRH release is mediated by PGE[sub 2], these results support the hypothesis that Pb is capable of altering the hypothalamus and suggest that this effect is due, at least in part, to the diminished PGE[sub 2] synthesis/release within the ME, resulting in diminished LHRH secretion.

  3. Degarelix monotherapy compared with luteinizing hormone-releasing hormone (LHRH) agonists plus anti-androgen flare protection in advanced prostate cancer: an analysis of two randomized controlled trials

    PubMed Central

    Iversen, Peter; Damber, Jan-Erik; Malmberg, Anders; Persson, Bo-Eric; Klotz, Laurence

    2015-01-01

    Objectives: The objective of this study was to assess differences in efficacy outcomes between luteinizing hormone-releasing hormone (LHRH) agonist plus antiandrogen (AA) flare protection and monotherapy with the gonadotrophin-releasing hormone antagonist degarelix in patients with prostate cancer. Methods: Data from 1455 patients were pooled from two prospective, phase III randomized 1-year clinical trials of degarelix versus LHRH agonist with or without AA. The AA bicalutamide was administered at the investigator’s discretion. Adjusted hazard ratios (HRs) were calculated using a Cox proportional hazards regression model and a conditional logistic regression model was used for a case-control analysis of odds ratios (ORs). Results: Patients received degarelix monotherapy (n = 972) or LHRH agonist (n = 483) of whom 57 also received AA. Overall, prostate-specific antigen progression-free survival (PSA PFS) was improved with degarelix versus LHRH agonist + AA (Cox proportional hazards regression model-adjusted HR for PSA PFS failure was 0.56 [95% confidence interval (CI) 0.33–0.97, p = 0.038]). To compensate for a higher proportion of patients with metastases, Gleason score 7–10, and PSA >20 ng/ml in the LHRH agonist + AA group, a case-control analysis using a conditional logistic regression model was utilized. This resulted in an OR for PSA PFS of 0.42 (95% CI 0.20–0.89; p = 0.023) in the overall population, and 0.35 (95% CI 0.13–0.96; p = 0.042) in patients with PSA >50 ng/ml at baseline, when treated with degarelix versus LHRH agonists + AA. There were a small number of deaths, 1.9% with degarelix and 7% with LHRH agonists + AA (case-control analysis OR = 0.37; p = 0.085). Conclusions: Degarelix monotherapy produced a more favorable effect on PSA PFS outcomes than a LHRH agonist + AA flare protection therapy in patients with prostate cancer when a case-control analysis was used to compensate for differences between treatment groups. PMID:27034720

  4. A comparison of human chorionic gonadotropin and luteinizing hormone releasing hormone on the induction of spermiation and amplexus in the American toad (Anaxyrus americanus)

    PubMed Central

    2012-01-01

    Background Captive breeding programs for endangered amphibian species often utilize exogenous hormones for species that are difficult to breed. The purpose of our study was to compare the efficacy of two different hormones at various concentrations on sperm production, quantity and quality over time in order to optimize assisted breeding. Methods Male American toads (Anaxyrus americanus) were divided into three separate treatment groups, with animals in each group rotated through different concentrations of luteinizing hormone releasing hormone analog (LHRH; 0.1, 1.0, 4.0 and 32 micrograms/toad), human chorionic gonadotropin (hCG; 50, 100, 200, and 300 IU), or the control over 24 hours. We evaluated the number of males that respond by producing spermic urine, the sperm concentration, percent motility, and quality of forward progression. We also evaluated the effects of hCG and LHRH on reproductive behavior as assessed by amplexus. Data were analyzed using the Generalized Estimating Equations incorporating repeated measures over time and including the main effects of treatment and time, and the treatment by time interaction. Results The hormone hCG was significantly more effective at stimulating spermiation in male Anaxyrus americanus than LHRH and showed a dose-dependent response in the number of animals producing sperm. At the most effective hCG dose (300 IU), 100% of the male toads produced sperm, compared to only 35% for the best LHRH dose tested (4.0 micrograms). In addition to having a greater number of responders (P < 0.05), the 300 IU hCG treatment group had a much higher average sperm concentration (P < 0.05) than the treatment group receiving 4.0 micrograms LHRH. In contrast, these two treatments did not result in significant differences in sperm motility or quality of forward progressive motility. However, more males went into amplexus when treated with LHRH vs. hCG (90% vs. 75%) by nine hours post-administration. Conclusion There is a clear

  5. Insulin-like growth factor-I mRNA and peptide in the human anterior pituitary.

    PubMed

    Jevdjovic, T; Bernays, R L; Eppler, E

    2007-05-01

    The pituitary is the central organ regulating virtually all endocrine processes, and pathologies of the pituitary cause manifold adverse effects. Because insulin-like growth factor (IGF)-I appears to be involved in tumour pathogenesis, progression, and persistence, and only few data exist on the cellular synthesis sites of IGF-I, the present study aims to create a basis for further research on pituitary adenomas by investigating the presence of IGF-I in the human pituitary using reverse transcriptase-polymerase chain reaction, in situ hybridisation, immunohistochemistry and immunocytochemistry. IGF-I was expressed in the pituitary, and gene sequence analysis revealed a sequence identical to that found in human liver. The distribution pattern of IGF-I mRNA found by in situ hybridisation corresponded to that of IGF-I peptide in immunohistochemistry. In all pituitary samples investigated, IGF-I-immunoreactivity occurred in almost all adrenocorticotrophic hormone (ACTH)-immunoreactive cells. Occasionally, an interindividually varying number of growth hormone (GH) and, infrequently, follicle-stimulating hormone and luteinising hormone cells contained IGF-I-immunoreactivity but none was detected in supporting cells. At the ultrastructural level, IGF-I-immunoreactivity was confined to secretory granules in coexistence with ACTH- or GH-immunoreactivity, respectively, indicating a concomitant release of the hormones. Thus, in humans, IGF-I appears to be a constituent in ACTH cells whereas its production in GH-producing and gonadotrophic cells may depend on the physiological status (e.g. serum IGF-I level, age or reproductive phase). It is assumed that locally produced IGF-I plays a crucial role in the regulation of endocrine cells by autocrine/paracrine mechanisms in addition to the endocrine route. PMID:17425608

  6. alpha-Lactalbumin hydrolysate stimulates glucagon-like peptide-2 secretion and small intestinal growth in suckling rats.

    PubMed

    Izumi, Hirohisa; Ishizuka, Satoshi; Inafune, Ayako; Hira, Tohru; Ozawa, Kazuhiro; Shimizu, Takashi; Takase, Mitsunori; Hara, Hiroshi

    2009-07-01

    We investigated whether bovine milk constituents influenced glucagon-like peptide (GLP)-2 secretion and intestinal growth in suckling rats. Male Sprague-Dawley rats (14 d old) received i.g. infusions of a milk protein fraction, a lactose solution, or the cream fraction of milk. The serum concentration of GLP-2, but not GLP-1, markedly increased in rats administered milk protein compared with those given the lactose solution or the cream fraction from 60 to 120 min after administration. In another experiment, both casein (CN) and whey protein isolate stimulated GLP-2 secretion at 120 min after administration, but soy protein and ovalbumin did not. Stimulation of GLP-2 secretion by several milk proteins was similar, including alpha-CN, alpha-lactalbumin (alpha-La), and beta-lactoglobulin, in a separate experiment. A hydrolysate of alpha-La obtained by incubation with protease A extracted from Aspergillus oryzae (LaHPA) caused almost twice the GLP-2 release due to intact alpha-La and other alpha-La hydrolysates. Free amino acid concentrations and molecular size distributions did not differ among alpha-La hydrolysates, including LaHPA. In rat pups reared with milk formulae containing alpha-La or LaHPA, LaHPA significantly promoted small intestinal elongation and increased the number of crypt epithelial cells compared with a formula containing intact alpha-La. LaHPA administration also increased the maltase:lactase activity ratio, a marker of maturation of the intestinal mucosa. In conclusion, milk proteins stimulate GLP-2 secretion and contribute to growth and maturation of the small intestine in suckling rats. PMID:19494023

  7. Effects of antimicrobial peptides on Staphylococcus aureus growth and biofilm formation in vitro following isolation from implant-associated infections

    PubMed Central

    Zhao, Guangfeng; Zhong, Huiming; Zhang, Mao; Hong, Yucai

    2015-01-01

    To prevent biomaterial-associated infections, antibiotic agents are recommended for various medical conditions requiring biomaterial implants, but resistance often appears after the introduction of antibiotics into clinical use. Therefore, new strategies for the prevention or treatment for biomaterial-associated infections are required. The purpose of this study was to evaluate the effects of antimicrobial peptides on growth and biofilm formation of Staphylococcus aureus isolated from implant-associated infections. A total of 20 patients with culture-proven staphylococcal infection associated with stable orthopedic implants were selected as the experimental group. S. aureus were isolated from tissue biopsies for identification, the isolated strains were mixed with Tet213 incubated at 37°C and viable bactrial number of S. aureus was counted. For the biofilm formation, the broad spectrum AMP Tet213 was selected and loaded onto the Ti coating first. At the same time Ti coated with Tet213 were mixed with S. aureus in vitro to form biofilm. After 30 min, 2 h, 4 h, 6 h, 8 h, the population of S. aureus in the biofilm was counted. Tet213 showed significant antibacterial effect on 16 strains (P < 0.05, Table 1). The inhibition rate reached above 80% among 12 strains of the clinically isolated strain. In biofilm experiments, counts of the NO. 1, 2, 3, 4 strains in biofilms decreased significantly after 2 h (P < 0.05), while there was no obvious difference in counts of NO. 5 strain (P > 0.05). The broad spectrum AMP Tet213 could strongly reduce the growth and biofilm formation of S. aureus in vitro, and the use of this might be an important new approach to target implant-associated infections. PMID:25785171

  8. Modulation of Calcium Oxalate Dihydrate Growth by Selective Crystal-face Binding of Phosphorylated Osteopontin and Polyaspartate Peptide Showing Occlusion by Sectoral (Compositional) Zoning*

    PubMed Central

    Chien, Yung-Ching; Masica, David L.; Gray, Jeffrey J.; Nguyen, Sarah; Vali, Hojatollah; McKee, Marc D.

    2009-01-01

    Calcium oxalate dihydrate (COD) mineral and the urinary protein osteopontin/uropontin (OPN) are commonly found in kidney stones. To investigate the effects of OPN on COD growth, COD crystals were grown with phosphorylated OPN or a polyaspartic acid-rich peptide of OPN (DDLDDDDD, poly-Asp86–93). Crystals grown with OPN showed increased dimensions of the {110} prismatic faces attributable to selective inhibition at this crystallographic face. At high concentrations of OPN, elongated crystals with dominant {110} faces were produced, often with intergrown, interpenetrating twin crystals. Poly-Asp86–93 dose-dependently elongated crystal morphology along the {110} faces in a manner similar to OPN. In crystal growth studies using fluorescently tagged poly-Asp86–93 followed by imaging of crystal interiors using confocal microscopy, sectoral (compositional) zoning in COD was observed resulting from selective binding and incorporation (occlusion) of peptide exclusively into {110} crystal sectors. Computational modeling of poly-Asp86–93 adsorption to COD {110} and {101} surfaces also suggests increased stabilization of the COD {110} surface and negligible change to the natively stable {101} surface. Ultrastructural, colloidal-gold immunolocalization of OPN by transmission electron microscopy in human stones confirmed an intracrystalline distribution of OPN. In summary, OPN and its poly-Asp86–93 sequence similarly affect COD mineral growth; the {110} crystallographic faces become enhanced and dominant attributable to {110} face inhibition by the protein/peptide, and peptides can incorporate into the mineral phase. We, thus, conclude that the poly-Asp86–93 domain is central to the OPN ability to interact with the {110} faces of COD, where it binds to inhibit crystal growth with subsequent intracrystalline incorporation (occlusion). PMID:19581305

  9. The Role of “Mixed” Orexigenic and Anorexigenic Signals and Autoantibodies Reacting with Appetite-Regulating Neuropeptides and Peptides of the Adipose Tissue-Gut-Brain Axis: Relevance to Food Intake and Nutritional Status in Patients with Anorexia Nervosa and Bulimia Nervosa

    PubMed Central

    Papezova, Hana; Vondra, Karel; Hill, Martin; Hainer, Vojtech; Nedvidkova, Jara

    2013-01-01

    Eating disorders such as anorexia (AN) and bulimia nervosa (BN) are characterized by abnormal eating behavior. The essential aspect of AN is that the individual refuses to maintain a minimal normal body weight. The main features of BN are binge eating and inappropriate compensatory methods to prevent weight gain. The gut-brain-adipose tissue (AT) peptides and neutralizing autoantibodies play an important role in the regulation of eating behavior and growth hormone release. The mechanisms for controlling food intake involve an interplay between gut, brain, and AT. Parasympathetic, sympathetic, and serotoninergic systems are required for communication between brain satiety centre, gut, and AT. These neuronal circuits include neuropeptides ghrelin, neuropeptide Y (NPY), peptide YY (PYY), cholecystokinin (CCK), leptin, putative anorexigen obestatin, monoamines dopamine, norepinephrine (NE), serotonin, and neutralizing autoantibodies. This extensive and detailed report reviews data that demonstrate that hunger-satiety signals play an important role in the pathogenesis of eating disorders. Neuroendocrine dysregulations of the AT-gut-brain axis peptides and neutralizing autoantibodies may result in AN and BN. The circulating autoantibodies can be purified and used as pharmacological tools in AN and BN. Further research is required to investigate the orexigenic/anorexigenic synthetic analogs and monoclonal antibodies for potential treatment of eating disorders in clinical practice. PMID:24106499

  10. Velvet antler peptide prevents pressure overload-induced cardiac fibrosis via transforming growth factor (TGF)-β1 pathway inhibition.

    PubMed

    Zhao, Lihong; Mi, Yang; Guan, Hongya; Xu, Yan; Mei, Yingwu

    2016-07-15

    Velvet antlers (VAs) are commonly used in traditional Chinese medicine and invigorant and contain many functional components for health promotion. The velvet antler peptide sVAP32 is one of active components in VAs; based on structural study, the sVAP32 interacts with TGF-β1 receptors and disrupts the TGF-β1 pathway. We hypothesized that sVAP32 prevents cardiac fibrosis from pressure overload by blocking TGF-β1 signaling. Sprague-Dawley rats underwent transverse aortic constriction (TAC) or a sham operation. After one month, rats received either sVAP32 (15mg/kg/day) or vehicle for an additional one month. TAC surgery induced significant cardiac dysfunction, fibroblast activation and fibrosis; these effects were improved by treatment with sVAP32. In the heart tissue, TAC remarkably increased the expression of TGF-β1 and connective tissue growth factor (CTGF), reactive oxygen species levels, and the phosphorylation levels of Smad2/3 and extracellular signal-regulated kinases 1/2 (ERK1/2). SVAP32 inhibited the increases in reactive oxygen species levels, CTGF expression and the phosphorylation of Smad2/3 and ERK1/2, but not TGF-β1 expression. In cultured cardiac fibroblasts, angiotensin II (Ang II) had similar effects compared to TAC surgery, such as increases in α-SMA-positive cardiac fibroblasts and collagen synthesis. SVAP32 eliminated these effects by disrupting TGF-β1 binding to its receptors and blocking Ang II/TGF-β1 downstream signaling. These results demonstrated that sVAP32 has anti-fibrotic effects by blocking the TGF-β1 pathway in cardiac fibroblasts. PMID:27108788

  11. Replication Attempt: “Effect of BMAP-28 Antimicrobial Peptides on Leishmania Major Promastigote and Amastigote Growth: Role of Leishmanolysin in Parasite Survival”

    PubMed Central

    Iorns, Elizabeth; Gunn, William; Erath, Jessey; Rodriguez, Ana; Zhou, Jian; Benzinou, Michael

    2014-01-01

    This study describes an attempt to replicate experiments from the paper “Effect of BMAP-28 Antimicrobial Peptides on Leishmania major Promastigote and Amastigote Growth: Role of Leishmanolysin in Parasite Survival,” which was submitted to the Reproducibility Initiative for independent validation. The cathelicidin bovine myeloid antimicrobial peptide 28 (BMAP-28) and its isomers were previously shown to have potent antiparasitic activity against Leishmania major. We tested the effectiveness of L-BMAP-28 and two of its isomers, the D-amino acid form (D-BMAP-28) and the retro-inverso form (RI-BMAP-28), in both unamidated and amidated forms, as anti-leishmanial agents against Leishmania major promastigotes in vitro. We observed that L-BMAP-28, as well as its D and RI isomers, demonstrate anti-leishmanial activity against L. major promastigotes in vitro. The inhibitory effect was lower than what was seen in the original study. At 2 µM of amidated peptides, the viability was 94%, 36%, and 66% with L-, D- and RI-peptides, versus 57%, 6%, and 18% in the original study. PMID:25517992

  12. Overexpression of Peptide-Encoding OsCEP6.1 Results in Pleiotropic Effects on Growth in Rice (O. sativa)

    PubMed Central

    Sui, Zhipeng; Wang, Tianya; Li, Hongjian; Zhang, Ming; Li, Yangyang; Xu, Ruibin; Xing, Guofang; Ni, Zhongfu; Xin, Mingming

    2016-01-01

    Plant peptide hormones play an important role in regulating plant developmental programs via cell-to-cell communication in a non-cell autonomous manner. To characterize the biological relevance of C-TERMINALLY ENCODED PEPTIDE (CEP) genes in rice, we performed a genome-wide search against public databases using a bioinformatics approach and identified six additional CEP members. Expression analysis revealed a spatial-temporal pattern of OsCEP6.1 gene in different tissues and at different developmental stages of panicle. Interestingly, the expression level of the OsCEP6.1 was also significantly up-regulated by exogenous cytokinin. Application of a chemically synthesized 15-amino acid OsCEP6.1 peptide showed that OsCEP6.1 had a negative role in regulating root and seedling growth, which was further confirmed by transgenic lines. Furthermore, the constitutive expression of OsCEP6.1 was sufficient to lead to panicle architecture and grain size variations. Scanning electron microscopy analysis revealed that the phenotypic variation of OsCEP6.1 overexpression lines resulted from decreased cell size but not reduced cell number. Moreover, starch accumulation was not significantly affected. Taken together, these data suggest that the OsCEP6.1 peptide might be involved in regulating the development of panicles and grains in rice. PMID:26973672

  13. Overexpression of Peptide-Encoding OsCEP6.1 Results in Pleiotropic Effects on Growth in Rice (O. sativa).

    PubMed

    Sui, Zhipeng; Wang, Tianya; Li, Hongjian; Zhang, Ming; Li, Yangyang; Xu, Ruibin; Xing, Guofang; Ni, Zhongfu; Xin, Mingming

    2016-01-01

    Plant peptide hormones play an important role in regulating plant developmental programs via cell-to-cell communication in a non-cell autonomous manner. To characterize the biological relevance of C-TERMINALLY ENCODED PEPTIDE (CEP) genes in rice, we performed a genome-wide search against public databases using a bioinformatics approach and identified six additional CEP members. Expression analysis revealed a spatial-temporal pattern of OsCEP6.1 gene in different tissues and at different developmental stages of panicle. Interestingly, the expression level of the OsCEP6.1 was also significantly up-regulated by exogenous cytokinin. Application of a chemically synthesized 15-amino acid OsCEP6.1 peptide showed that OsCEP6.1 had a negative role in regulating root and seedling growth, which was further confirmed by transgenic lines. Furthermore, the constitutive expression of OsCEP6.1 was sufficient to lead to panicle architecture and grain size variations. Scanning electron microscopy analysis revealed that the phenotypic variation of OsCEP6.1 overexpression lines resulted from decreased cell size but not reduced cell number. Moreover, starch accumulation was not significantly affected. Taken together, these data suggest that the OsCEP6.1 peptide might be involved in regulating the development of panicles and grains in rice. PMID:26973672

  14. Expanded test method for peptides >2 kDa employing immunoaffinity purification and LC-HRMS/MS.

    PubMed

    Thomas, Andreas; Walpurgis, Katja; Tretzel, Laura; Brinkkötter, Paul; Fichant, Eric; Delahaut, Philippe; Schänzer, Wilhelm; Thevis, Mario

    2015-01-01

    Bioactive peptides with an approximate molecular mass of 2-12 kDa are of considerable relevance in sports drug testing. Such peptides have been used to manipulate several potential performance-enhancing processes in the athlete's body and include for example growth hormone releasing hormones (sermorelin, CJC-1293, CJC-1295, tesamorelin), synthetic/animal insulins (lispro, aspart, glulisine, glargine, detemir, degludec, bovine and porcine insulin), synthetic ACTH (synacthen), synthetic IGF-I (longR(3) -IGF-I) and mechano growth factors (human MGF, modified human MGF, 'full-length' MGF). A combined initial test method using one analytical procedure is a desirable tool in doping controls and related disciplines as requests for higher sample throughput with utmost comprehensiveness preferably at reduced costs are constantly issued. An approach modified from an earlier assay proved fit-for-purpose employing pre-concentration of all target analytes by means of ultrafiltration, immunoaffinity purification with coated paramagnetic beads, nano-ultra high performance liquid chromatography (UHPLC) separation, and subsequent detection by means of high resolution tandem mass spectrometry. The method was shown to be applicable to blood and urine samples, which represent the most common doping control specimens. The method was validated considering the parameters specificity, recovery (11-69%), linearity, imprecision (<25%), limit of detection (5-100 pg in urine, 0.1-2 ng in plasma), and ion suppression. The analysis of administration study samples for insulin degludec, detemir, aspart, and synacthen provided the essential data for the proof-of-principle of the method. PMID:26382721

  15. Non-steroidal antiandrogen monotherapy compared with luteinizing hormone-releasing hormone agonists or surgical castration monotherapy for advanced prostate cancer: a Cochrane systematic review.

    PubMed

    Kunath, Frank; Grobe, Henrik R; Rücker, Gerta; Motschall, Edith; Antes, Gerd; Dahm, Philipp; Wullich, Bernd; Meerpohl, Joerg J

    2015-07-01

    To assess the effects of non-steroidal antiandrogen monotherapy compared with luteinizing hormone-releasing hormone agonists or surgical castration monotherapy for treating advanced hormone-sensitive stages of prostate cancer. We searched the Cochrane Prostatic Diseases and Urologic Cancers Group Specialized Register (PROSTATE), the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Web of Science with Conference Proceedings, three trial registries and abstracts from three major conferences to 23 December 2013, together with reference lists, and contacted selected experts in the field and manufacturers. We included randomized controlled trials comparing non-steroidal antiandrogen monotherapy with medical or surgical castration monotherapy for men in advanced hormone-sensitive stages of prostate cancer. Two review authors independently examined full-text reports, identified relevant studies, assessed the eligibility of studies for inclusion, extracted data and assessed risk of bias as well as quality of evidence according to the GRADE working group guidelines. We used Review Manager 5.2 for data synthesis and the fixed-effect model as primary analysis (when heterogeneity was low with I(2) < 50%); we used a random-effects model when confronted with substantial or considerable heterogeneity (when I(2) ≥50%). A total of 11 studies involving 3060 randomly assigned participants were included in the present review. Use of non-steroidal antiandrogens resulted in lower overall survival times (hazard ratio [HR] 1.24, 95% confidence interval [CI] 1.05-1.48, six studies, 2712 participants) and greater clinical progression (1 year: risk ratio [RR] 1.25, 95% CI 1.08-1.45, five studies, 2067 participants; 70 weeks: RR 1.26, 95% CI 1.08-1.45, six studies, 2373 participants; 2 years: RR 1.14, 95% CI 1.04-1.25, three studies, 1336 participants), as well as treatment failure (1 year: RR 1.19, 95% CI 1.02-1.38, four studies, 1539 participants; 70 weeks: RR 1

  16. Non-coding Double-stranded RNA and Antimicrobial Peptide LL-37 Induce Growth Factor Expression from Keratinocytes and Endothelial Cells.

    PubMed

    Adase, Christopher A; Borkowski, Andrew W; Zhang, Ling-Juan; Williams, Michael R; Sato, Emi; Sanford, James A; Gallo, Richard L

    2016-05-27

    A critical function for skin is that when damaged it must simultaneously identify the nature of the injury, repair barrier function, and limit the intrusion of pathogenic organisms. These needs are carried out through the detection of damage-associated molecular patterns (DAMPs) and a response that includes secretion of cytokines, chemokines, growth factors, and antimicrobial peptides (AMPs). In this study, we analyzed how non-coding double-stranded RNA (dsRNAs) act as a DAMP in the skin and how the human cathelicidin AMP LL-37 might influence growth factor production in response to this DAMP. dsRNA alone significantly increased the expression of multiple growth factors in keratinocytes, endothelial cells, and fibroblasts. Furthermore, RNA sequencing transcriptome analysis found that multiple growth factors increase when cells are exposed to both LL-37 and dsRNA, a condition that mimics normal wounding. Quantitative PCR and/or ELISA validated that growth factors expressed by keratinocytes in these conditions included, but were not limited to, basic fibroblast growth factor (FGF2), heparin-binding EGF-like growth factor (HBEGF), vascular endothelial growth factor C (VEGFC), betacellulin (BTC), EGF, epiregulin (EREG), and other members of the transforming growth factor β superfamily. These results identify a novel role for DAMPs and AMPs in the stimulation of repair and highlight the complex interactions involved in the wound environment. PMID:27048655

  17. Facile rhenium-peptide conjugate synthesis using a one-pot derived Re(CO)3 reagent.

    PubMed

    Chanawanno, Kullapa; Kondeti, Vinay; Caporoso, Joel; Paruchuri, Sailaja; Leeper, Thomas C; Herrick, Richard S; Ziegler, Christopher J

    2016-03-21

    We have synthesized two Re(CO)3-modified lysine complexes (1 and 2), where the metal is attached to the amino acid at the Nε position, via a one-pot Schiff base formation reaction. These compounds can be used in the solid phase synthesis of peptides, and to date we have produced four conjugate systems incorporating neurotensin, bombesin, leutenizing hormone releasing hormone, and a nuclear localization sequence. We observed uptake into human umbilical vascular endothelial cells as well as differential uptake depending on peptide sequence identity, as characterized by fluorescence and rhenium elemental analysis. PMID:26863280

  18. Antimicrobial peptides.

    PubMed

    Zhang, Ling-Juan; Gallo, Richard L

    2016-01-11

    Antimicrobial peptides and proteins (AMPs) are a diverse class of naturally occurring molecules that are produced as a first line of defense by all multicellular organisms. These proteins can have broad activity to directly kill bacteria, yeasts, fungi, viruses and even cancer cells. Insects and plants primarily deploy AMPs as an antibiotic to protect against potential pathogenic microbes, but microbes also produce AMPs to defend their environmental niche. In higher eukaryotic organisms, AMPs can also be referred to as 'host defense peptides', emphasizing their additional immunomodulatory activities. These activities are diverse, specific to the type of AMP, and include a variety of cytokine and growth factor-like effects that are relevant to normal immune homeostasis. In some instances, the inappropriate expression of AMPs can also induce autoimmune diseases, thus further highlighting the importance of understanding these molecules and their complex activities. This Primer will provide an update of our current understanding of AMPs. PMID:26766224

  19. A VEGFR1 antagonistic peptide inhibits tumor growth and metastasis through VEGFR1-PI3K-AKT signaling pathway inhibition

    PubMed Central

    Zhou, Zheng; Zhao, Chuanke; Wang, Lixin; Cao, Xiaodan; Li, Jian; Huang, Ruijing; Lao, Qiaocong; Yu, Hangping; Li, Yanna; Du, Haiyan; Qu, Like; Shou, Chengchao

    2015-01-01

    Angiogenesis is central to the growth of cancers and VEGFR-1/Flt-1 plays an important role during the neovascularization under pathological conditions. We previously founded a VEGFR1 antagonistic peptide, F56, by screening the phage peptide library. We showed that DHFR-F56 chimeric protein displayed anti-tumor activity and inhibited angiogenesis, however the anti-tumor activity of monomeric F56 and the mechanism remain unclear. In this study, we found that the F56 didn’t affect VEGF-A induced endothelial cell proliferation, but reduced migration and tube formation of endothelial cells. F56 also inhibited the sprout of rat aortic endothelial cells, the angiogenesis of chicken embryo chorioallantoic membrane as well as the generation of subintestinal vein vessels (SIV) in zebrafish embryos. We found that F56 inhibited VEGF-induced phosphorylation of VEGFR1, as well as the phosphorylation of the downstream of PI3K-AKT axis. However, F56 had no effect on the phosphorylation of VEGFR2. Correlating with these effects, F56 inhibited xenograft growth of HT-29 and MGC-823 cells in BALB/c nude mice, and significantly suppressed the lung metastasis of B16 cells in C57BL/6 mice. Our study demonstrated that monomeric peptide F56 had a significant anti-tumor activity by inhibiting angiogenesis, and laid the foundation for its clinical application. PMID:26693066

  20. CD10/neutral endopeptidase 24.11 regulates fetal lung growth and maturation in utero by potentiating endogenous bombesin-like peptides.

    PubMed Central

    King, K A; Hua, J; Torday, J S; Drazen, J M; Graham, S A; Shipp, M A; Sunday, M E

    1993-01-01

    Bombesin-like peptides (BLPs) are mitogens for bronchial epithelial cells and small cell lung carcinomas, and increase fetal lung growth and maturation in utero and in organ cultures. BLPs are hydrolyzed by the enzyme CD10/neutral endopeptidase 24.11 (CD10/NEP) which is expressed in bronchial epithelium and functions to inhibit BLP-mediated growth of small cell lung carcinomas. To determine whether CD10/NEP regulates peptide-mediated lung development, we administered a specific CD10/NEP inhibitor, SCH32615, to fetal mice in utero from gestational days e15-17. Fetal lung tissues were evaluated on e18 for: (a) growth using [3H]thymidine incorporation into nuclear DNA; and (b) maturation using: [3H]-choline incorporation into surfactant phospholipids, electron microscopy for type II pneumocytes, and Northern blot analyses for surfactant apoproteins A, B, and C. Inhibition of CD10/NEP stimulated [3H]thymidine incorporation into DNA (70% above baseline, P < 0.005), [3H]choline incorporation into surfactant phospholipids (38% above baseline, P < 0.005), increased numbers of type II pneumocytes (36% above baseline, P = 0.07), and fivefold higher surfactant protein A transcripts (P < 0.05). CD10/NEP-mediated effects were completely blocked by the specific bombesin receptor antagonist, [D-Phe12, Leu14]bombesin. These observations suggest that CD10/NEP regulates fetal lung growth and maturation mediated by endogenous BLPs. Images PMID:8486767

  1. Neutral endopeptidase-resistant C-type natriuretic peptide variant represents a new therapeutic approach for treatment of fibroblast growth factor receptor 3-related dwarfism.

    PubMed

    Wendt, Daniel J; Dvorak-Ewell, Melita; Bullens, Sherry; Lorget, Florence; Bell, Sean M; Peng, Jeff; Castillo, Sianna; Aoyagi-Scharber, Mika; O'Neill, Charles A; Krejci, Pavel; Wilcox, William R; Rimoin, David L; Bunting, Stuart

    2015-04-01

    Achondroplasia (ACH), the most common form of human dwarfism, is caused by an activating autosomal dominant mutation in the fibroblast growth factor receptor-3 gene. Genetic overexpression of C-type natriuretic peptide (CNP), a positive regulator of endochondral bone growth, prevents dwarfism in mouse models of ACH. However, administration of exogenous CNP is compromised by its rapid clearance in vivo through receptor-mediated and proteolytic pathways. Using in vitro approaches, we developed modified variants of human CNP, resistant to proteolytic degradation by neutral endopeptidase, that retain the ability to stimulate signaling downstream of the CNP receptor, natriuretic peptide receptor B. The variants tested in vivo demonstrated significantly longer serum half-lives than native CNP. Subcutaneous administration of one of these CNP variants (BMN 111) resulted in correction of the dwarfism phenotype in a mouse model of ACH and overgrowth of the axial and appendicular skeletons in wild-type mice without observable changes in trabecular and cortical bone architecture. Moreover, significant growth plate widening that translated into accelerated bone growth, at hemodynamically tolerable doses, was observed in juvenile cynomolgus monkeys that had received daily subcutaneous administrations of BMN 111. BMN 111 was well tolerated and represents a promising new approach for treatment of patients with ACH. PMID:25650377

  2. Intestinal regulation of urinary sodium excretion and the pathophysiology of diabetic kidney disease: a focus on glucagon-like peptide 1 and dipeptidyl peptidase 4.

    PubMed

    Vallon, Volker; Docherty, Neil G

    2014-09-01

    The tubular hypothesis of glomerular filtration and nephropathy in diabetes is a pathophysiological concept that assigns a critical role to the tubular system, including proximal tubular hyper-reabsorption and growth, which is relevant for early glomerular hyperfiltration and later chronic kidney disease. Here we focus on how harnessing the bioactivity of hormones released from the gut may ameliorate the early effects of diabetes on the kidney in part by attenuating proximal tubular hyper-reabsorption and growth. The endogenous tone of the glucagon-like peptide 1 (GLP-1)/GLP-1 receptor (GLP-1R) system and its pharmacological activation are nephroprotective in diabetes independent of changes in blood glucose. This is associated with suppression of increases in kidney weight and glomerular hyperfiltration, which may reflect, at least in part, its inhibitory effects on tubular hyper-reabsorption and growth. Inhibition of dipeptidyl peptidase 4 (DPP-4) is also nephroprotective independent of changes in blood glucose and involves GLP-1/GLP-1R-dependent and -independent mechanisms. The GLP-1R agonist exendin-4 induces natriuresis via activation of the GLP-1R. In contrast, DPP4 inhibition increases circulating GLP-1, but drives a GLP-1R-independent natriuretic response, implying a role for other DPP-4 substrates. The extent to which the intrarenal DPP-4/GLP-1 receptor system contributes to all these changes remains to be established, as does the direct impact of the system on renal inflammation. PMID:25085841

  3. Effects of composite antimicrobial peptides in weanling piglets challenged with deoxynivalenol: I. Growth performance, immune function, and antioxidation capacity.

    PubMed

    Xiao, H; Wu, M M; Tan, B E; Yin, Y L; Li, T J; Xiao, D F; Li, L

    2013-10-01

    The mycotoxin deoxynivalenol (DON) is a food contaminant that leads to reduced feed intake and reduced BW gain, as well as organ impairment. On the other hand, antimicrobial peptides have been shown to have positive effects on growth performance, nutrient digestibility, and immune function. The purpose of this study was to investigate the protective effects of composite antimicrobial peptides (CAP) on piglets challenged with DON. After a 7-d adaptation period, 28 individually housed piglets (Duroc × Landrace × Large Yorkshire) weaned at 28 d of age were randomly assigned to receive 1 of 4 treatments (7 pigs/treatment): negative control, basal diet (NC), basal diet + 0.4% CAP (CAP), basal diet + 4 mg/kg DON (DON), and basal diet + 4 ppm DON + 0.4% CAP (DON + CAP). On d 15 and 30 after the initiation of treatment, blood samples were collected for the determination of blood profile. Piglets were monitored for 30 d to assess performance and then were slaughtered to obtain organs for the determination of the relative weight of organs. The results showed that dietary supplementation with DON decreased (P < 0.05) ADFI, ADG, and G:F, whereas dietary supplementation with CAP improved ADG and G:F (P < 0.05). The relative weight of the kidney and pancreas was greater and the relative weight of the spleen was lighter in the DON treatment than in the other 3 treatments (P < 0.05). There were no effects (P > 0.05) on other relative weights of viscera, except the relative weight of the gallbladder, but the diamine oxidase activity in the liver decreased in DON-treated piglets (P < 0.05). Piglets in the DON treatment had increased serum concentrations of alkaline phosphatase, alanine transaminase, and aspartate aminotransferase and a dramatic decrease in total protein (P < 0.05), whereas there were no differences (P > 0.05) between the DON + CAP treatment and the other treatments. The DON treatment decreased the numbers of red blood cells and platelets, as well as the serum

  4. GHRH, PRP-PACAP and GHRHR Target Sequencing via an Ion Torrent Personal Genome Machine Reveals an Association with Growth in Orange-Spotted Grouper (Epinephelus coioides)

    PubMed Central

    Guo, Liang; Xia, Junhong; Yang, Sen; Li, Mingming; You, Xinxin; Meng, Zining; Lin, Haoran

    2015-01-01

    Growth hormone-releasing hormone (GHRH) and the receptor, GHRHR, constitute important components of the hypothalamus-pituitary growth axis and act on the downstream growth hormone (GH). PACAP-related peptide/pituitary adenylate cyclase activating polypeptide (PRP-PACAP) is a paralog of GHRH. These genes all play key roles in development and growth patterns. To improve the quality of cultured fish strains, natural genetic variation must be examined and understood. A mixed linear model has been widely used in association mapping, taking the population structures and pairwise kinship patterns into consideration. In this study, a mass cross population of orange-spotted grouper (Epinephelus coioides) was examined. These candidate genes were found to harbor low nucleotide diversity (θw from 0.00154 to 0.00388) and linkage disequilibrium levels (delay of 50% within 2 kbp). Association mapping was employed, and two single-nucleotide polymorphisms (KR269823.1:g.475A>C and KR269823.1:g.2143T>C) were found to be associated with growth (false discovery rate Q < 0.05), explaining 9.0%–17.0% of the phenotypic variance. The association of KR269823.1:g.2143T>C was also found via haplotype-based association (p < 0.05). The identified associations offer new insights into gene functions, and the associated single-nucleotide polymorphisms (SNPs) may be used for breeding purposes. PMID:26540042

  5. Reiterated Targeting Peptides on the Nanoparticle Surface Significantly Promote Targeted Vascular Endothelial Growth Factor Gene Delivery to Stem Cells.

    PubMed

    Wang, Dong-Dong; Yang, Mingying; Zhu, Ye; Mao, Chuanbin

    2015-12-14

    Nonviral gene delivery vectors hold great promise for gene therapy due to the safety concerns with viral vectors. However, the application of nonviral vectors is hindered by their low transfection efficiency. Herein, in order to tackle this challenge, we developed a nonviral vector integrating lipids, sleeping beauty transposon system and 8-mer stem cell targeting peptides for safe and efficient gene delivery to hard-to-transfect mesenchymal stem cells (MSCs). The 8-mer MSC-targeting peptides, when synthetically reiterated in three folds and chemically presented on the surface, significantly promoted the resultant lipid-based nanoparticles (LBNs) to deliver VEGF gene into MSCs with a high transfection efficiency (∼52%) and long-lasting gene expression (for longer than 170 h) when compared to nonreiterated peptides. However, the reiterated stem cell targeting peptides do not enable the highly efficient gene transfer to other control cells. This work suggests that the surface presentation of the reiterated stem cell-targeting peptides on the nonviral vectors is a promising method for improving the efficiency of cell-specific nonviral gene transfection in stem cells. PMID:26588028

  6. Overexpression of apolipoprotein A-I fused to an anti-transforming growth factor beta peptide modulates the tumorigenicity and immunogenicity of mouse colon cancer cells.

    PubMed

    Medina-Echeverz, José; Vasquez, Marcos; Gomar, Celia; Ardaiz, Nuria; Berraondo, Pedro

    2015-06-01

    Transforming growth factor beta (TGF-β) promotes tumor growth, invasion and metastasis in established tumors. In this study, we analyzed the effect of overexpressing an anti-TGF-β peptide fused to apolipoprotein A-I (ApoA-I) as a scaffold molecule. We generated and characterized stable MC38 colon carcinoma clones expressing ApoA-I fused to the anti-TGF-β peptide P144 and ApoA-I as control cells. We evaluated in vitro the gene expression profile, cell cycle and anchorage-independent growth. The in vivo tumorigenic potential and immunogenicity were analyzed inoculating the MC38 clones into C57BL/6 mice, recombination-activating gene 1 knockout mice or mice deficient in NK cells either subcutaneously or intrasplenically to generate hepatic metastases. While overexpression of ApoA-I had no effect on the parameters analyzed, ApoA-I fused to P144 markedly diminished the tumorigenic capacity and metastatic potential of MC38 in vitro and in vivo, thus generating a highly immunogenic cell line. MC38 cells transfected with ApoA-I fused to P144 triggered memory T cell responses able to eliminate the parental cell line upon re-challenge. In summary, expression of ApoA-I fused to P144 is a novel strategy to modulate TGF-β in tumor cells. These results highlight the potential of TGF-β as a target in the development of new antitumor treatments. PMID:25795134

  7. Exploring the in meso crystallization mechanism by characterizing the lipid mesophase microenvironment during the growth of single transmembrane α-helical peptide crystals.

    PubMed

    van 't Hag, Leonie; Knoblich, Konstantin; Seabrook, Shane A; Kirby, Nigel M; Mudie, Stephen T; Lau, Deborah; Li, Xu; Gras, Sally L; Mulet, Xavier; Call, Matthew E; Call, Melissa J; Drummond, Calum J; Conn, Charlotte E

    2016-07-28

    The proposed mechanism for in meso crystallization of transmembrane proteins suggests that a protein or peptide is initially uniformly dispersed in the lipid self-assembly cubic phase but that crystals grow from a local lamellar phase, which acts as a conduit between the crystal and the bulk cubic phase. However, there is very limited experimental evidence for this theory. We have developed protocols to investigate the lipid mesophase microenvironment during crystal growth using standard procedures readily available in crystallography laboratories. This technique was used to characterize the microenvironment during crystal growth of the DAP12-TM peptide using synchrotron small angle X-ray scattering (SAXS) with a micro-sized X-ray beam. Crystal growth was found to occur from the gyroid cubic mesophase. For one in four crystals, a highly oriented local lamellar phase was observed, providing supporting evidence for the proposed mechanism for in meso crystallization. A new observation of this study was that we can differentiate diffraction peaks from crystals grown in meso, from peaks originating from the surrounding lipid matrix, potentially opening up the possibility of high-throughput SAXS analysis of in meso grown crystals.This article is part of the themed issue 'Soft interfacial materials: from fundamentals to formulation'. PMID:27298442

  8. Immunoglobulin Fc-fused, neuropilin-1-specific peptide shows efficient tumor tissue penetration and inhibits tumor growth via anti-angiogenesis.

    PubMed

    Kim, Ye-Jin; Bae, Jeomil; Shin, Tae-Hwan; Kang, Se Hun; Jeong, Moonkyoung; Han, Yunho; Park, Ji-Ho; Kim, Seok-Ki; Kim, Yong-Sung

    2015-10-28

    Neuropilin-1 (NRP1) receptor, involved in vascular endothelial growth factor (VEGF)-mediated vascular permeability and tumor angiogenesis, is targeted by peptides that bind to its VEGF-binding site. However, these peptides also cross-react with the structurally related receptor, NRP2. Here, we describe an immunoglobulin Fc-fused peptide, Fc-TPP11, which specifically binds to the VEGF-binding site of NRP1 with approximately 2nM affinity, but negligibly to that of NRP2. Fc-TPP11 triggered NRP1-dependent signaling, enhanced vascular permeability via vascular endothelial (VE)-cadherin downregulation, and increased paracellular permeability via E-cadherin downregulation in tumor tissues. Fc-TPP11 also significantly enhanced the tumor penetration of co-injected anti-cancer drug, doxorubicin, leading to the improved in vivo anti-tumor efficacy. Fc-TPP11 was easily adapted to the full-length anti-epidermal growth factor receptor (EGFR) monoclonal antibody (mAb) cetuximab (Erbitux), cetuximab-TPP11, exhibiting more than 2-fold improved tumor penetration than the parent cetuximab. Fc-TPP11 exhibited a similar whole-body half-life to that of intact Fc in tumor bearing mice. In addition to the tumor-penetrating activity, Fc-TPP11 suppressed VEGF-dependent angiogenesis by blocking VEGF binding to NRP1, thereby inhibiting tumor growth without promoting metastasis in the mouse model. Our results show that NRP1-specific, high-affinity binding of Fc-TPP11, is useful to validate NRP1 signaling, independent of NRP2. Thus, Fc-TPP11 can be used as a tumor penetration-promoting agent with anti-angiogenic activity or directly adapted to mAb-TPP11 format for more potent anti-cancer antibody therapy. PMID:26260451

  9. Regulation of feeding behavior and food intake by appetite-regulating peptides in wild-type and growth hormone-transgenic coho salmon.

    PubMed

    White, Samantha L; Volkoff, Helene; Devlin, Robert H

    2016-08-01

    Survival, competition, growth and reproductive success in fishes are highly dependent on food intake, food availability and feeding behavior and are all influenced by a complex set of metabolic and neuroendocrine mechanisms. Overexpression of growth hormone (GH) in transgenic fish can result in greatly enhanced growth rates, feed conversion, feeding motivation and food intake. The objectives of this study were to compare seasonal feeding behavior of non-transgenic wild-type (NT) and GH-transgenic (T) coho salmon (Oncorhynchus kisutch), and to examine the effects of intraperitoneal injections of the appetite-regulating peptides cholecystokinin (CCK-8), bombesin (BBS), glucagon-like peptide-1 (GLP-1), and alpha-melanocyte-stimulating hormone (α-MSH) on feeding behavior. T salmon fed consistently across all seasons, whereas NT dramatically reduced their food intake in winter, indicating the seasonal regulation of appetite can be altered by overexpression of GH in T fish. Intraperitoneal injections of CCK-8 and BBS caused a significant and rapid decrease in food intake for both genotypes. Treatment with either GLP-1 or α-MSH resulted in a significant suppression of food intake for NT but had no effect in T coho salmon. The differential response of T and NT fish to α-MSH is consistent with the melanocortin-4 receptor system being a significant pathway by which GH acts to stimulate appetite. Taken together, these results suggest that chronically increased levels of GH alter feeding regulatory pathways to different extents for individual peptides, and that altered feeding behavior in transgenic coho salmon may arise, in part, from changes in sensitivity to peripheral appetite-regulating signals. PMID:27149948

  10. Suppressed spontaneous secretion of growth hormone in girls after treatment for acute lymphoblastic leukaemia.

    PubMed Central

    Moëll, C; Garwicz, S; Westgren, U; Wiebe, T; Albertsson-Wikland, K

    1989-01-01

    The spontaneous secretion of growth hormone during a 24 hour period and the response of growth hormone to growth hormone releasing hormone was studied in 13 girls who had received treatment for acute lymphoblastic leukemia that included cranial irradiation with 20-24 Gy in 12-14 fractions. At the time of investigation the girls were at varying stages of puberty and had normal concentrations of thyroid hormones. The mean interval between the end of treatment and investigation was 4.6 years. The mean age at onset of the disease was 3.2 years and at investigation 10.7 years. The average attained height equalled -0.3 SD at onset, and -1.0 SD at the time of investigation. Secretion of growth hormone was substantially reduced compared with controls and did not increase during puberty. A prompt rise in growth hormone secretion was seen after injection of growth hormone releasing hormone, but the mean maximum growth hormone concentration was, however, only 25 mU/l. There was no correlation between the 24 hour secretion and growth hormone response to growth hormone releasing hormone, or the time since irradiation. These results confirm earlier work that suggested that girls who had received treatment for acute lymphoblastic leukaemia, that included cranial irradiation, have a comparative growth hormone insufficiency characterised by normal prepubertal growth and slow growth during puberty because of an inability to respond to the increased demands for growth hormone at that time. PMID:2494952

  11. Radiolabeling and evaluation of 64Cu-DOTA-F56 peptide targeting vascular endothelial growth factor receptor 1 in the molecular imaging of gastric cancer

    PubMed Central

    Zhu, Hua; Zhao, Chuanke; Liu, Fei; Wang, Lixin; Feng, Junnan; Zhou, Zheng; Qu, Like; Shou, Chengchao; Yang, Zhi

    2015-01-01

    Noninvasive imaging of vascular endothelial growth factor receptor 1 (VEGFR1) remains a great challenge in early diagnosis of gastric cancer. Here we reported the synthesis, radiolabeling, and evaluation of a novel 64Cu-radiolabeled peptide for noninvasive positron emission tomography (PET) imaging of VEGFR1 positive gastric cancer. The binding of modified peptide WHSDMEWWYLLG (termed as F56) to VEGER-1 expressed in gastric cancer cell BCG823 has been confirmed by immune-fluorescence overlap. DOTA-F56 was designed and prepared by solid-phase synthesis and folded in vitro. 64Cu-DOTA-F56 was synthesized in high radiochemical yield and high specific activity (S.A. up to 255.6 GBq/mmol). It has excellent in vitro stability. Micro-PET imaging of 64Cu-DOTA-F56 identifies tumor in BCG823 tumor-bearing mice, while that of 18F-FDG does not. Immunohistochemical analysis of excised BCG823 xenograft showed colocalization between the PET images and the staining of VEGFR1. These results demonstrated that 64Cu-DOTA-F56 peptide has potential as a noninvasive imaging agent in VEGFR1 positive tumors. PMID:26807312

  12. A novel recombinant slow-release TNF α-derived peptide effectively inhibits tumor growth and angiogensis.

    PubMed

    Ma, Yi; Zhao, Shaojun; Shen, Shutao; Fang, Shixiong; Ye, Zulu; Shi, Zhi; Hong, An

    2015-01-01

    RMP16, a recombinant TNF α-derived polypeptide comprising a specific human serum albumin (HSA)-binding 7-mer peptide identified by phage display screening (WQRPSSW), a cleavage peptide for Factor Xa (IEGR), and a 20-amino acid bioactive peptide P16 (TNF α segment including amino acid residues 75-94), was prepared by gene-engineering technology. RMP16 showed prolonged half-life, 13.11 hours in mice (half-lives of P16 and TNF α are 5.77 and 29.0 minutes, respectively), and obviously higher receptor selectivity for TNFRI than TNF α. RMP16 had significant inhibition effects for multiple tumor cells, especially prostate cancer Du145 cells, and human vascular endothelial cells but not for human mammary non-tumorigenic epithelial cells. RMP16 can more effectively induce apoptosis and inhibit proliferation for DU145 cells than P16 and TNF α via the caspase-dependent apoptosis pathway and G0/G1 cell cycle arrest. In nude mice with transplanted tumor of DU145 cells, RMP16 significantly induced apoptosis and necrosis of tumor tissues but causing less side effects, and tumor inhibitory rate reached nearly 80%, furthermore, RMP16 can potently inhibit tumor angiogenesis and neovascularization. These findings suggest that RMP16 may represent a promising long-lasting antitumor therapeutic peptide with less TNF α-induced toxicity. PMID:26337231

  13. A novel recombinant slow-release TNF α-derived peptide effectively inhibits tumor growth and angiogensis

    PubMed Central

    Ma, Yi; Zhao, Shaojun; Shen, Shutao; Fang, Shixiong; Ye, Zulu; Shi, Zhi; Hong, An

    2015-01-01

    RMP16, a recombinant TNF α-derived polypeptide comprising a specific human serum albumin (HSA)-binding 7-mer peptide identified by phage display screening (WQRPSSW), a cleavage peptide for Factor Xa (IEGR), and a 20-amino acid bioactive peptide P16 (TNF α segment including amino acid residues 75–94), was prepared by gene-engineering technology. RMP16 showed prolonged half-life, 13.11 hours in mice (half-lives of P16 and TNF α are 5.77 and 29.0 minutes, respectively), and obviously higher receptor selectivity for TNFRI than TNF α. RMP16 had significant inhibition effects for multiple tumor cells, especially prostate cancer Du145 cells, and human vascular endothelial cells but not for human mammary non-tumorigenic epithelial cells. RMP16 can more effectively induce apoptosis and inhibit proliferation for DU145 cells than P16 and TNF α via the caspase-dependent apoptosis pathway and G0/G1 cell cycle arrest. In nude mice with transplanted tumor of DU145 cells, RMP16 significantly induced apoptosis and necrosis of tumor tissues but causing less side effects, and tumor inhibitory rate reached nearly 80%, furthermore, RMP16 can potently inhibit tumor angiogenesis and neovascularization. These findings suggest that RMP16 may represent a promising long-lasting antitumor therapeutic peptide with less TNF α-induced toxicity. PMID:26337231

  14. Glucagon-like peptide-2 (GLP-2) increases small intestinal blood flow and mucosal growth in ruminating calves

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glucagon-like peptide-2 (GLP-2), increases small intestinal mass and blood flow in non-ruminants, but its effect in ruminants is unknown. Eight Holstein calves with an ultrasonic flow probe around the superior mesenteric artery (SMA), and catheters in the carotid artery and mesenteric vein, were pa...

  15. LPXRFamide peptide stimulates growth hormone and prolactin gene expression during the spawning period in the grass puffer, a semi-lunar synchronized spawner.

    PubMed

    Shahjahan, Md; Doi, Hiroyuki; Ando, Hironori

    2016-02-01

    Gonadotropin-inhibitory hormone (GnIH) plays as a multifunctional neurohormone that controls reproduction in birds and mammals. LPXRFamide (LPXRFa) peptide, the fish ortholog of GnIH, has been shown to regulate the secretion of not only gonadotropin (GTH) but also growth hormone (GH) and prolactin (PRL), which are potentially important for gonadal function. To investigate the role of LPXRFa peptide on reproduction of the grass puffer, which spawns in semilunar cycles, we examined changes in the levels of gh and prl expression over the several months during the reproductive cycle, and the effects of goldfish LPXRFa peptide-1 (gfLPXRFa-1) on their expression were examined using primary pituitary cultures. The expression levels of both gh and prl showed significant changes during the reproductive cycle in both sexes with one peak in the spawning and pre-spawning periods for gh and prl, respectively. Particularly, gh showed substantial increase in expression in the spawning and post-spawning periods, indicative of its essentiality in the advanced stage of reproduction. gfLPXRFa-1 stimulated the expression of both gh and prl but there was a marked difference in response between them: gfLPXRFa-1 stimulated gh expression at a relatively low dose but little effect was observed on prl. Combined with the previous results of daily and circadian oscillations of lpxrfa expression, the present results suggest that LPXRFa peptide is important in the control of the cyclic reproduction by serving as a multifunctional hypophysiotropic factor that regulates the expression of gh and prl as well as GTH subunit genes. PMID:26385315

  16. Transient silencing of Npr3 gene expression improved the circulatory levels of atrial natriuretic peptides and attenuated β-adrenoceptor activation- induced cardiac hypertrophic growth in experimental rats.

    PubMed

    Venkatesan, Balaji; Tumala, Anusha; Subramanian, Vimala; Vellaichamy, Elangovan

    2016-07-01

    Natriuretic peptide receptor-C (NPR-C) is considered as a clearance receptor that maintains the circulatory levels of natriuretic peptides. It has been suggested that augmented expression of NPR-C as a cause for the diminished anti-hypertrophic action of natriuretic peptides in the failing heart. Hence, we sought to determine the level of Npr3 gene (coding for NPR-C) expression in the Isoproterenol (ISO) treated Wistar rats. In addition, we studied the effect of Npr3 gene silencing on the hypertrophic growth. A significant increase in heart weight-to-body weight ratio (HW/BW-24%,P<0.01), an indicator of cardiac hypertrophic growth was observed in the ISO (10mg/kg BW/day,i.p for 7 days) treated rats. As expected, the cardiac NPR-C protein expression was significantly increased by 4 fold as compared to control rats. In parallel, the circulatory atrial natriuretic peptide (ANP) level was significantly decreased (2 fold) in ISO treated rats. Upon treatment with siRNA-Npr3, a significant decrease in the cardiac NPR-C protein expression (70%,P<0.01), HW/BW ratio (70%,P<0.01) and hypertrophic marker genes (α-Sk, β-MHC, c-fos, P<0.01, respectively) mRNA expression were observed. Interestingly, the circulatory ANP level was increased by 1.5 fold in the siRNA-Npr3 treated rats as compared to ISO treated rats. Moreover, the cardiac collagen content, matrixmetalloprotinases-2 (MMP-2) and enzymatic antioxidant status (P<0.01, respectively) were found to be restored back to near normal upon siRNA-Npr3 treatment. Taken together, the results of this study indicates that specific down-regulation of Npr3 gene improves the circulatory levels of ANP and antioxidant system and there by attenuates the β-adrenoceptor over-activation mediated cardiac hypertrophic growth in experimental rats. PMID:27108789

  17. Identification of a ghrelin-like peptide in two species of shark, Sphyrna lewini and Carcharhinus melanopterus.

    PubMed

    Kawakoshi, Akatsuki; Kaiya, Hiroyuki; Riley, Larry G; Hirano, Tetsuya; Grau, E Gordon; Miyazato, Mikiya; Hosoda, Hiroshi; Kangawa, Kenji

    2007-05-01

    In this study, we identified a ghrelin-like peptide (ghrelin-LP) in two elasmobranchs. The peptide, isoforms and cDNA encoding its precursor were isolated from the stomach of two sharks, the hammerhead (HH) shark (Sphyrna lewini) and the black-tip reef (BTR) shark (Carcharhinus melanopterus). The ghrelin-LP isolated from each shark was found to be 25 amino acids in length and exhibit high sequence homology with each other; only three amino acids were different. As has been shown in tetrapod and teleost fish ghrelins, shark ghrelin-LPs possess two forms that are distinguished by having the third serine residue (Ser) acylated by either octanoic or decanoic acid. The N-terminal four residues (GVSF), known as the active core of ghrelin, are not identical to those of other species (GSSF). Nevertheless, shark ghrelin-LP elevated Ca(2+) levels in CHO cell line expressing the growth hormone secretagogue receptor (GHS-R). Unlike teleosts ghrelin's, shark ghrelin-LPs are not amidated at the C-terminus. Messenger RNA of ghrelin-LP in the HH shark was predominantly expressed in the stomach as seen in other species, followed by the brain, intestine, gill, heart and liver. The nucleotide sequence of the ghrelin-LP gene in the HH shark was characterized to compare organization of the ghrelin gene with those in other species. The size of the HH ghrelin-LP gene was 8541 bp, two to ten times larger than that of other species studied to date. The HH ghrelin-LP gene is composed of five exons and four introns, which is the same as ghrelin genes in mammals, chicken and rainbow trout. In conclusion, the shark ghrelin-LPs identified in this study exhibit many characteristics for ghrelin in terms of peptide modifications, GHS-R activation, tissue distribution, and gene organization; however, it is necessary to further clarify their biological properties such as growth hormone-releasing or orexigenic activity before designating these peptides as ghrelin. PMID:17362948

  18. A placental growth factor-positively charged peptide potentiates the antitumor activity of interferon-gamma in human brain glioblastoma U87 cells

    PubMed Central

    Liu, Yu; Chen, Naifei; Yin, Hongmei; Zhang, Leilei; Li, Wei; Wang, Guanjun; Cui, Jiuwei; Yang, Bo; Hu, Ji-Fan

    2016-01-01

    Interferons have been marketed to treat hematological malignancies, but their efficacy in the treatment of solid tumors has been significantly hindered by low antitumor efficacy and numerous side effects. We used a “cDNA in-frame fragment” library screening method to identify short cDNA peptides that potentiate the anti-tumor activity of interferons. In this study, we synthesized a hybrid molecule by fusing a short positively charged peptide derived from placental growth factor-2 to the C-terminus of human IFNγ. Using the human brain glioblastoma U87 cell line as a model system, we found that the hybrid interferon exhibited significantly higher activity than did the wild-type IFNγ in inhibiting tumor cell growth. As compared with the unmodified IFNγ, the hybrid interferon was better at inhibiting cell invasion in a matri-gel assay and at decreasing tumor colony formation. The enhanced antitumor activity of the synthetic interferon was correlated with the activation of interferon pathway genes and the blockade of tumor cell division at the S-G2/M phase. This study demonstrates the potential of a synthetic IFNγ for use as a novel antitumor agent.

  19. The Nutrient-Responsive Hormone CCHamide-2 Controls Growth by Regulating Insulin-like Peptides in the Brain of Drosophila melanogaster.

    PubMed

    Sano, Hiroko; Nakamura, Akira; Texada, Michael J; Truman, James W; Ishimoto, Hiroshi; Kamikouchi, Azusa; Nibu, Yutaka; Kume, Kazuhiko; Ida, Takanori; Kojima, Masayasu

    2015-05-01

    The coordination of growth with nutritional status is essential for proper development and physiology. Nutritional information is mostly perceived by peripheral organs before being relayed to the brain, which modulates physiological responses. Hormonal signaling ensures this organ-to-organ communication, and the failure of endocrine regulation in humans can cause diseases including obesity and diabetes. In Drosophila melanogaster, the fat body (adipose tissue) has been suggested to play an important role in coupling growth with nutritional status. Here, we show that the peripheral tissue-derived peptide hormone CCHamide-2 (CCHa2) acts as a nutrient-dependent regulator of Drosophila insulin-like peptides (Dilps). A BAC-based transgenic reporter revealed strong expression of CCHa2 receptor (CCHa2-R) in insulin-producing cells (IPCs) in the brain. Calcium imaging of brain explants and IPC-specific CCHa2-R knockdown demonstrated that peripheral-tissue derived CCHa2 directly activates IPCs. Interestingly, genetic disruption of either CCHa2 or CCHa2-R caused almost identical defects in larval growth and developmental timing. Consistent with these phenotypes, the expression of dilp5, and the release of both Dilp2 and Dilp5, were severely reduced. Furthermore, transcription of CCHa2 is altered in response to nutritional levels, particularly of glucose. These findings demonstrate that CCHa2 and CCHa2-R form a direct link between peripheral tissues and the brain, and that this pathway is essential for the coordination of systemic growth with nutritional availability. A mammalian homologue of CCHa2-R, Bombesin receptor subtype-3 (Brs3), is an orphan receptor that is expressed in the islet β-cells; however, the role of Brs3 in insulin regulation remains elusive. Our genetic approach in Drosophila melanogaster provides the first evidence, to our knowledge, that bombesin receptor signaling with its endogenous ligand promotes insulin production. PMID:26020940

  20. The Nutrient-Responsive Hormone CCHamide-2 Controls Growth by Regulating Insulin-like Peptides in the Brain of Drosophila melanogaster

    PubMed Central

    Sano, Hiroko; Nakamura, Akira; Texada, Michael J.; Truman, James W.; Ishimoto, Hiroshi; Kamikouchi, Azusa; Nibu, Yutaka; Kume, Kazuhiko; Ida, Takanori; Kojima, Masayasu

    2015-01-01

    The coordination of growth with nutritional status is essential for proper development and physiology. Nutritional information is mostly perceived by peripheral organs before being relayed to the brain, which modulates physiological responses. Hormonal signaling ensures this organ-to-organ communication, and the failure of endocrine regulation in humans can cause diseases including obesity and diabetes. In Drosophila melanogaster, the fat body (adipose tissue) has been suggested to play an important role in coupling growth with nutritional status. Here, we show that the peripheral tissue-derived peptide hormone CCHamide-2 (CCHa2) acts as a nutrient-dependent regulator of Drosophila insulin-like peptides (Dilps). A BAC-based transgenic reporter revealed strong expression of CCHa2 receptor (CCHa2-R) in insulin-producing cells (IPCs) in the brain. Calcium imaging of brain explants and IPC-specific CCHa2-R knockdown demonstrated that peripheral-tissue derived CCHa2 directly activates IPCs. Interestingly, genetic disruption of either CCHa2 or CCHa2-R caused almost identical defects in larval growth and developmental timing. Consistent with these phenotypes, the expression of dilp5, and the release of both Dilp2 and Dilp5, were severely reduced. Furthermore, transcription of CCHa2 is altered in response to nutritional levels, particularly of glucose. These findings demonstrate that CCHa2 and CCHa2-R form a direct link between peripheral tissues and the brain, and that this pathway is essential for the coordination of systemic growth with nutritional availability. A mammalian homologue of CCHa2-R, Bombesin receptor subtype-3 (Brs3), is an orphan receptor that is expressed in the islet β-cells; however, the role of Brs3 in insulin regulation remains elusive. Our genetic approach in Drosophila melanogaster provides the first evidence, to our knowledge, that bombesin receptor signaling with its endogenous ligand promotes insulin production. PMID:26020940

  1. [Plant signaling peptides. Cysteine-rich peptides].

    PubMed

    Ostrowski, Maciej; Kowalczyk, Stanisław

    2015-01-01

    Recent bioinformatic and genetic analyses of several model plant genomes have revealed the existence of a highly abundant group of signaling peptides that are defined as cysteine-rich peptides (CRPs). CRPs are usually in size between 50 and 90 amino acid residues, they are positively charged, and they contain 4-16 cysteine residues that are important for the correct conformational folding. Despite the structural differences among CRP classes, members from each class have striking similarities in their molecular properties and function. The present review presents the recent progress in research on signaling peptides from several families including: EPF/EPFL, SP11/SCR, PrsS, RALF, LURE, and some other peptides belonging to CRP group. There is convincing evidence indicating multiple roles for these CRPs as signaling molecules during the plant life cycle, ranging from stomata development and patterning, self-incompatibility, pollen tube growth and guidance, reproductive processes, and nodule formation. PMID:26281357

  2. Studies of the chemical basis of the origin of protein synthesis Initiation and direction of peptide growth

    NASA Technical Reports Server (NTRS)

    Mullins, D. W., Jr.; Lacey, J. C., Jr.

    1980-01-01

    The data presented in this paper show that the ease of nonenzymatic activation of carboxylic acids by ATP at pH 5 varies directly with the pKa of the carboxyl group, and is consistent with the idea that it is the protonated form of the carboxyl group which participates in the activation reaction. Consequently, since most N-blocked amino acids have higher pKas than do their unblocked forms, they are activated more readily, and it has been demonstrated that this principle applies to peptides as well, which are activated more rapidly than single amino acids. It is proposed that this fact may be partly responsible for the origin of two important features still observed in contemporary protein synthesis: (1) initiation in prokaryotes is accomplished with an N-blocked amino acid, and (2) elongation in all living systems occurs at the carboxyl end of the growing peptide.

  3. Selective inhibition of JNK with a peptide inhibitor attenuates pain hypersensitivity and tumor growth in a mouse skin cancer pain model.

    PubMed

    Gao, Yong-Jing; Cheng, Jen-Kun; Zeng, Qing; Xu, Zhen-Zhong; Decosterd, Isabelle; Xu, Xiaoyin; Ji, Ru-Rong

    2009-09-01

    Cancer pain significantly affects the quality of cancer patients, and current treatments for this pain are limited. C-Jun N-terminal kinase (JNK) has been implicated in tumor growth and neuropathic pain sensitization. We investigated the role of JNK in cancer pain and tumor growth in a skin cancer pain model. Injection of luciferase-transfected B16-Fluc melanoma cells into a hindpaw of mouse induced robust tumor growth, as indicated by increase in paw volume and fluorescence intensity. Pain hypersensitivity in this model developed rapidly (<5 days) and reached a peak in 2 weeks, and was characterized by mechanical allodynia and heat hyperalgesia. Tumor growth was associated with JNK activation in tumor mass, dorsal root ganglion (DRG), and spinal cord and a peripheral neuropathy, such as loss of nerve fibers in the hindpaw skin and induction of ATF-3 expression in DRG neurons. Repeated systemic injections of D-JNKI-1 (6 mg/kg, i.p.), a selective and cell-permeable peptide inhibitor of JNK, produced an accumulative inhibition of mechanical allodynia and heat hyperalgesia. A bolus spinal injection of D-JNKI-1 also inhibited mechanical allodynia. Further, JNK inhibition suppressed tumor growth in vivo and melanoma cell proliferation in vitro. In contrast, repeated injections of morphine (5 mg/kg), a commonly used analgesic for terminal cancer, produced analgesic tolerance after 1 day and did not inhibit tumor growth. Our data reveal a marked peripheral neuropathy in this skin cancer model and important roles of the JNK pathway in cancer pain development and tumor growth. JNK inhibitors such as D-JNKI-1 may be used to treat cancer pain. PMID:19445931

  4. Targeting the EGFR/PCNA Signaling Suppresses Tumor Growth of Triple-Negative Breast Cancer Cells with Cell-Penetrating PCNA Peptides

    PubMed Central

    Yu, Yung-Luen; Chou, Ruey-Hwang; Liang, Jia-Hong; Chang, Wei-Jung; Su, Kuo-Jung; Tseng, Yen-Ju; Huang, Wei-Chien; Wang, Shao-Chun; Hung, Mien-Chie

    2013-01-01

    Tyrosine 211 (Y211) phosphorylation of proliferation cell nuclear antigen (PCNA) coincides with pronounced cancer cell proliferation and correlates with poor survival of breast cancer patients. In epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI)-resistant cells, both nuclear EGFR (nEGFR) expression and PCNA Y211 phosphorylation are increased. Moreover, the resistance to EGFR TKI is a major clinical problem in treating EGFR-overexpressing triple-negative breast cancer (TNBC). Thus, effective treatment to combat resistance is urgently needed. Here, we show that treatment of cell-penetrating PCNA peptide (CPPP) inhibits growth and induces apoptosis of human TNBC cells. The Y211F CPPP specifically targets EGFR and competes directly for PCNA tyrosine Y211 phosphorylation and prevents nEGFR from binding PCNA in vivo; it also suppresses tumor growth by sensitizing EGFR TKI resistant cells, which have enhanced nEGFR function and abrogated classical EGFR membrane signaling. Furthermore, we identify an active motif of CPPP, RFLNFF (RF6 CPPP), which is necessary and sufficient to inhibit TKI-resistant TNBC cell growth of orthotopic implanted tumor in mice. Finally, the activity of its synthetic retro-inverted derivative, D-RF6 CPPP, on an equimolar basis, is more potent than RF6 CPPP. Our study reveals a drug candidate with translational potential for the future development of safe and effective therapeutic for EGFR TKI resistance in TNBC. PMID:23593472

  5. Human recombinant endopeptidase PHEX has a strict S1' specificity for acidic residues and cleaves peptides derived from fibroblast growth factor-23 and matrix extracellular phosphoglycoprotein.

    PubMed Central

    Campos, Marcelo; Couture, Constance; Hirata, Izaura Y; Juliano, Maria A; Loisel, Thomas P; Crine, Philippe; Juliano, Luiz; Boileau, Guy; Carmona, Adriana K

    2003-01-01

    The PHEX gene (phosphate-regulating gene with homologies to endopeptidases on the X chromosome) encodes a protein (PHEX) with structural homologies to members of the M13 family of zinc metallo-endopeptidases. Mutations in the PHEX gene are responsible for X-linked hypophosphataemia in humans. However, the mechanism by which loss of PHEX function results in the disease phenotype, and the endogenous PHEX substrate(s) remain unknown. In order to study PHEX substrate specificity, combinatorial fluorescent-quenched peptide libraries containing o -aminobenzoic acid (Abz) and 2,4-dinitrophenyl (Dnp) as the donor-acceptor pair were synthesized and tested as PHEX substrates. PHEX showed a strict requirement for acidic amino acid residues (aspartate or glutamate) in S(1)' subsite, with a strong preference for aspartate. Subsites S(2)', S(1) and S(2) exhibited less defined specificity requirements, but the presence of leucine, proline or glycine in P(2)', or valine, isoleucine or histidine in P(1) precluded hydrolysis of the substrate by the enzyme. The peptide Abz-GFSDYK(Dnp)-OH, which contains the most favourable residues in the P(2) to P(2)' positions, was hydrolysed by PHEX at the N-terminus of aspartate with a k(cat)/ K(m) of 167 mM(-1) x s(-1). In addition, using quenched fluorescence peptides derived from fibroblast growth factor-23 and matrix extracellular phosphoglycoprotein sequences flanked by Abz and N -(2,4-dinitrophenyl)ethylenediamine, we showed that these physiologically relevant proteins are potential PHEX substrates. Finally, our results clearly indicate that PHEX does not have neprilysin-like substrate specificity. PMID:12678920

  6. Cationicity-enhanced analogues of the antimicrobial peptides, AcrAP1 and AcrAP2, from the venom of the scorpion, Androctonus crassicauda, display potent growth modulation effects on human cancer cell lines.

    PubMed

    Du, Qiang; Hou, Xiaojuan; Ge, Lilin; Li, Renjie; Zhou, Mei; Wang, Hui; Wang, Lei; Wei, Minjie; Chen, Tianbao; Shaw, Chris

    2014-01-01

    The non disulphide-bridged peptides (NDBPs) of scorpion venoms are attracting increased interest due to their structural heterogeneity and broad spectrum of biological activities. Here, two novel peptides, named AcrAP1 and AcrAP2, have been identified in the lyophilised venom of the Arabian scorpion, Androctonus crassicauda, through "shotgun" molecular cloning of their biosynthetic precursor-encoding cDNAs. The respective mature peptides, predicted from these cloned cDNAs, were subsequently isolated from the same venom sample using reverse phase HPLC and their identities were confirmed by use of mass spectrometric techniques. Both were found to belong to a family of highly-conserved scorpion venom antimicrobial peptides - a finding confirmed through the biological investigation of synthetic replicates. Analogues of both peptides designed for enhanced cationicity, displayed enhanced potency and spectra of antimicrobial activity but, unlike the native peptides, these also displayed potent growth modulation effects on a range of human cancer cell lines. Thus natural peptide templates from venom peptidomes can provide the basis for rational analogue design to improve both biological potency and spectrum of action. The diversity of such templates from such natural sources undoubtedly provides the pharmaceutical industry with unique lead compounds for drug discovery. PMID:25332684

  7. Boosting production yield of biomedical peptides

    NASA Technical Reports Server (NTRS)

    Manatt, S. L.

    1978-01-01

    Nuclear magnetic resonance (NMR) technique is employed to monitor synthesis of biomedical peptides. Application of NMR technique may improve production yields of insulin, ACTH, and growth hormones, as well as other synthesized biomedical peptides.

  8. Incorporation of Exogenous RGD Peptide and Inter-Species Blending as Strategies for Enhancing Human Corneal Limbal Epithelial Cell Growth on Bombyx mori Silk Fibroin Membranes

    PubMed Central

    Bray, Laura J.; Suzuki, Shuko; Harkin, Damien G.; Chirila, Traian V.

    2013-01-01

    While fibroin isolated from the cocoons of domesticated silkworm Bombyx mori supports growth of human corneal limbal epithelial (HLE) cells, the mechanism of cell attachment remains unclear. In the present study we sought to enhance the attachment of HLE cells to membranes of Bombyx mori silk fibroin (BMSF) through surface functionalization with an arginine-glycine-aspartic acid (RGD)-containing peptide. Moreover, we have examined the response of HLE cells to BMSF when blended with the fibroin produced by a wild silkworm, Antheraea pernyi, which is known to contain RGD sequences within its primary structure. A procedure to isolate A. pernyi silk fibroin (APSF) from the cocoons was established, and blends of the two fibroins were prepared at five different BMSF/APSF ratios. In another experiment, BMSF surface was modified by binding chemically the GRGDSPC peptide using a water-soluble carbodiimide. Primary HLE were grown in the absence of serum on membranes made of BMSF, APSF, and their blends, as well as on RGD-modified BMSF. There was no statistically significant enhancing effect on the cell attachment due to the RGD presence. This suggests that the adhesion through RGD ligands may have a complex mechanism, and the investigated strategies are of limited value unless the factors contributing to this mechanism become better known. PMID:24955953

  9. Epidermal Growth Factor and Parathyroid Hormone-related Peptide mRNA in the Mammary Gland and their Concentrations in Milk

    PubMed Central

    Bruder, E. D.; Van Hoof, J.; Young, J. B.; Raff, H.

    2008-01-01

    The physiological adaptations of the neonatal rat to hypoxia from birth include changes in gastrointestinal function and intermediary metabolism. We hypothesized that the hypoxic lactating dam would exhibit alterations in mammary gland function leading to changes in the concentration of milk peptides that are important in neonatal gastrointestinal development. The present study assessed the effects of chronic hypoxia on peptides produced by the mammary glands and present in milk. Chronic hypoxia decreased the concentration of epidermal growth factor (EGF) in expressed milk and pup stomach contents and decreased maternal mammary gland Egf mRNA. The concentration of parathyroid hormone-related protein (PTHrp) was unchanged in milk and decreased in pup stomach contents; however, mammary Pthlh mRNA was increased by hypoxia. There was a significant increase in adiponectin concentrations in milk from hypoxic dams. Chronic hypoxia decreased maternal body weight, and pair feeding normoxic dams an amount of food equivalent to hypoxic dam food intake decreased body weight to an equivalent degree. Decreased food intake did not affect the expression of Egf, Pthlh, or Lep mRNA in mammary tissue. The results indicated that chronic hypoxia modulated mammary function independently of hypoxia-induced decreases in maternal food intake. Decreased EGF and increased adiponectin concentrations in milk from hypoxic dams likely affect the development of neonatal intestinal function. PMID:18401831

  10. Anti-metastatic effects of DNA vaccine encoding single-chain trimer composed of MHC I and vascular endothelial growth factor receptor 2 peptide.

    PubMed

    Chen, Ruiling; Wang, Shengchao; Yao, Yunliang; Zhou, Yun; Zhang, Chong; Fang, Jie; Zhang, Dayong; Zhang, Lihuang; Pan, Jianping

    2015-05-01

    Vascular endothelial growth factor receptor 2 (VEGFR2)-mediated signaling is the key rate-limiting step in angiogenesis. VEGFR2 serves as the most important target of anti-angiogenic therapy for cancers. Single-chain trimer (SCT) comprising antigen peptide, β2-microglobulin (β2m), and major histocompatibility complex (MHC) class I heavy chain was a particularly powerful strategy involved in the increase of the potency of DNA vaccine against tumors and infections. In the present study, we constructed an SCT-encoding VEGFR2 antigen peptide [aa400-408, also known as kinase insert domain-containing receptor (KDR2)], β2m, and mouse MHC class I heavy chain H-2Db [pcDNA3.1(+)-KDR2-β2m-H-2Db, or SCT-KDR2]. The constructed SCT-KDR2 DNA was efficiently expressed in the human A293 embryonic kidney cell line. Intradermal immunization of C57BL/6 mice with SCT-KDR2 DNA was able to successfully break self-immunological tolerance and induce robust cytotoxic T‑lymphocyte (CTL) response to VEGFR2, leading to marked suppression of tumor cell‑induced angiogenesis and metastasis in murine models of B16 melanoma and 3LL Lewis lung carcinoma. Taken together, the results showed that VEGFR2-targeted SCT vaccination is an effective modality that can be utilized in anti-angiogenic active immunotherapy for various types of cancer. PMID:25739076

  11. Dynamics of GHRH in third-ventricle cerebrospinal fluid of cattle: relationship with serum concentrations of GH and responses to appetite-regulating peptides

    PubMed Central

    Thomas, M.G.; Amstalden, M.; Hallford, D.M.; Silver, G.A.; Garcia, M.D.; Keisler, D.H.; Williams, G.L.

    2009-01-01

    Objectives were to 1) characterize the relationship of third-ventricle (IIIV) cerebrospinal fluid (CSF) concentrations of growth hormone releasing hormone (GHRH) with concentrations of GH in the peripheral circulation, and 2) assess the influence of acute administration of appetite-regulating peptides, leptin (anti-orexigenic) and neuropeptide Y (NPY; orexigenic) on release of GHRH. Six mature beef cows fitted with IIIV and jugular vein cannulae were treated intracerebroventricularly with saline, and leptin (600 μg) and NPY (500 μg) in saline, in a replicated 3 x 3 Latin square design. Third-ventricle CSF and blood were collected 10 min before and continued 220 min after treatments. Mean concentrations of GHRH and frequency of pulses after treatments were 2.2 ± 0.13 ng/mL and 1.2 ± 0.15 pulses/220 min, respectively. These measures were not influenced by treatments. Concentrations of GHRH in CSF were weakly correlated (r = 0.15; P < 0.03) with serum concentrations of GH; however, 58% of the GH pulses were preceded by a pulse of GHRH and 90% of the GHRH pulses occurred within 20 min preceding a pulse of GH. Leptin tended (P < 0.10) to suppress GH area under the curve (AUC) compared to saline. Concomitantly, NPY tended (P < 0.10) to increase GH AUC, which appeared to be a consequence of increased (P < 0.05) pulse amplitude. Infusion of NPY also increased (P < 0.05) AUC of GHRH relative to saline. No differences were detected among treatments in serum concentrations of IGF-I or its AUC. Sampling CSF from the IIIV appears to be a viable procedure for assessing hypothalamic release of GHRH coincident with anterior pituitary gland secretion of GH in cattle. These data also demonstrate the differential responsiveness of the GH axis to appetite-regulating peptides. PMID:19632078

  12. Adhesion between peptides/antibodies and breast cancer cells

    NASA Astrophysics Data System (ADS)

    Meng, J.; Paetzell, E.; Bogorad, A.; Soboyejo, W. O.

    2010-06-01

    Atomic force microscopy (AFM) techniques were used to measure the adhesion forces between the receptors on breast cancer cells specific to human luteinizing hormone-releasing hormone (LHRH) peptides and antibodies specific to the EphA2 receptor. The adhesion forces between LHRH-coated AFM tips and human MDA-MB-231 cells (breast cancer cells) were shown to be about five times greater than those between LHRH-coated AFM tips and normal Hs578Bst breast cells. Similarly, those between EphA2 antibody-coated AFM tips and breast cancer cells were over five times greater than those between EphA2 antibody-coated AFM tips and normal breast cells. The results suggest that AFM can be used for the detection of breast cancer cells in biopsies. The implications of the results are also discussed for the early detection and localized treatment of cancer.

  13. Cellular and molecular insight into the inhibition of primary root growth of Arabidopsis induced by peptaibols, a class of linear peptide antibiotics mainly produced by Trichoderma spp.

    PubMed Central

    Shi, Wei-Ling; Chen, Xiu-Lan; Wang, Li-Xia; Gong, Zhi-Ting; Li, Shuyu; Li, Chun-Long; Xie, Bin-Bin; Zhang, Wei; Shi, Mei; Li, Chuanyou; Zhang, Yu-Zhong; Song, Xiao-Yan

    2016-01-01

    Trichoderma spp. are well known biocontrol agents that produce a variety of antibiotics. Peptaibols are a class of linear peptide antibiotics mainly produced by Trichoderma. Alamethicin, the most studied peptaibol, is reported as toxic to plants at certain concentrations, while the mechanisms involved are unclear. We illustrated the toxic mechanisms of peptaibols by studying the growth-inhibitory effect of Trichokonin VI (TK VI), a peptaibol from Trichoderma longibrachiatum SMF2, on Arabidopsis primary roots. TK VI inhibited root growth by suppressing cell division and cell elongation, and disrupting root stem cell niche maintenance. TK VI increased auxin content and disrupted auxin response gradients in root tips. Further, we screened the Arabidopsis TK VI-resistant mutant tkr1. tkr1 harbors a point mutation in GORK, which encodes gated outwardly rectifying K+ channel proteins. This mutation alleviated TK VI-induced suppression of K+ efflux in roots, thereby stabilizing the auxin gradient. The tkr1 mutant also resisted the phytotoxicity of alamethicin. Our results indicate that GORK channels play a key role in peptaibol–plant interaction and that there is an inter-relationship between GORK channels and maintenance of auxin homeostasis. The cellular and molecular insight into the peptaibol-induced inhibition of plant root growth advances our understanding of Trichoderma–plant interactions. PMID:26850879

  14. Cellular and molecular insight into the inhibition of primary root growth of Arabidopsis induced by peptaibols, a class of linear peptide antibiotics mainly produced by Trichoderma spp.

    PubMed

    Shi, Wei-Ling; Chen, Xiu-Lan; Wang, Li-Xia; Gong, Zhi-Ting; Li, Shuyu; Li, Chun-Long; Xie, Bin-Bin; Zhang, Wei; Shi, Mei; Li, Chuanyou; Zhang, Yu-Zhong; Song, Xiao-Yan

    2016-04-01

    Trichodermaspp. are well known biocontrol agents that produce a variety of antibiotics. Peptaibols are a class of linear peptide antibiotics mainly produced byTrichoderma Alamethicin, the most studied peptaibol, is reported as toxic to plants at certain concentrations, while the mechanisms involved are unclear. We illustrated the toxic mechanisms of peptaibols by studying the growth-inhibitory effect of Trichokonin VI (TK VI), a peptaibol fromTrichoderma longibrachiatumSMF2, onArabidopsisprimary roots. TK VI inhibited root growth by suppressing cell division and cell elongation, and disrupting root stem cell niche maintenance. TK VI increased auxin content and disrupted auxin response gradients in root tips. Further, we screened theArabidopsisTK VI-resistant mutanttkr1tkr1harbors a point mutation inGORK, which encodes gated outwardly rectifying K(+)channel proteins. This mutation alleviated TK VI-induced suppression of K(+)efflux in roots, thereby stabilizing the auxin gradient. Thetkr1mutant also resisted the phytotoxicity of alamethicin. Our results indicate that GORK channels play a key role in peptaibol-plant interaction and that there is an inter-relationship between GORK channels and maintenance of auxin homeostasis. The cellular and molecular insight into the peptaibol-induced inhibition of plant root growth advances our understanding ofTrichoderma-plant interactions. PMID:26850879

  15. One-Dimensional Peptide Nanostructure Templated Growth of Iron Phosphate Nanostructures for Lithium-Ion Battery Cathodes.

    PubMed

    Susapto, Hepi Hari; Kudu, O Ulas; Garifullin, Ruslan; Yılmaz, Eda; Guler, Mustafa O

    2016-07-13

    Template-directed synthesis of nanomaterials can provide benefits such as small crystalline size, high surface area, large surface-to-volume ratio, and structural stability. These properties are important for shorter distance in ion/electron movement and better electrode surface/electrolyte contact for energy storage applications. Here nanostructured FePO4 cathode materials were synthesized by using peptide nanostructures as a template inspired by biomineralization process. The amorphous, high surface area FePO4 nanostructures were utilized as a cathode for lithium-ion batteries. Discharge capacity of 155 mAh/g was achieved at C/20 current rate. The superior properties of biotemplated and nanostructured amorphous FePO4 are shown compared to template-free crystalline FePO4. PMID:27315038

  16. Nucleation and Growth of Ordered Arrays of Silver Nanoparticles on Peptide Nanofibers: Hybrid Nanostructures with Antimicrobial Properties.

    PubMed

    Pazos, Elena; Sleep, Eduard; Rubert Pérez, Charles M; Lee, Sungsoo S; Tantakitti, Faifan; Stupp, Samuel I

    2016-05-01

    Silver nanoparticles have been of great interest as plasmonic substrates for sensing and imaging, catalysts, or antimicrobial systems. Their physical properties are strongly dependent on parameters that remain challenging to control such as size, chemical composition, and spatial distribution. We report here on supramolecular assemblies of a novel peptide amphiphile containing aldehyde functionality in order to reduce silver ions and subsequently nucleate silver metal nanoparticles in water. This system spontaneously generates monodisperse silver particles at fairly regular distances along the length of the filamentous organic assemblies. The metal-organic hybrid structures exhibited antimicrobial activity and significantly less toxicity toward eukaryotic cells. Metallized organic nanofibers of the type described here offer the possibility to create hydrogels, which integrate the useful functions of silver nanoparticles with controllable metallic content. PMID:27103596

  17. Antimicrobial peptides

    PubMed Central

    2014-01-01

    With increasing antibiotics resistance, there is an urgent need for novel infection therapeutics. Since antimicrobial peptides provide opportunities for this, identification and optimization of such peptides have attracted much interest during recent years. Here, a brief overview of antimicrobial peptides is provided, with focus placed on how selected hydrophobic modifications of antimicrobial peptides can be employed to combat also more demanding pathogens, including multi-resistant strains, without conferring unacceptable toxicity. PMID:24758244

  18. ML-18 is a non-peptide bombesin receptor subtype-3 antagonist which inhibits lung cancer growth.

    PubMed

    Moody, Terry W; Mantey, Samuel A; Moreno, Paola; Nakamura, Taichi; Lacivita, Enza; Leopoldo, Marcello; Jensen, Robert T

    2015-02-01

    Bombesin receptor subtype (BRS)-3 is a G protein coupled receptor (GPCR) for the bombesin (BB)-family of peptides. BRS-3 is an orphan GPCR and little is known of its physiological role due to the lack of specific agonists and antagonists. PD168368 is a nonpeptide antagonist for the neuromedin B (NMB) receptor (R) whereas PD176252 is a nonpeptide antagonist for the gastrin releasing peptide (GRP) R and NMBR but not BRS-3. Here nonpeptide analogs of PD176252 e.g. the S-enantiomer ML-18, and the R-enantiomer, EMY-98, were investigated as BRS-3 antagonists using lung cancer cells. ML-18 and EMY-98 inhibited specific (125)I-BA1 (DTyr-Gln-Trp-Ala-Val-βAla-His-Phe-Nle-NH2)BB(6-14) binding to NCI-H1299 lung cancer cells stably transfected with BRS-3 with IC50 values of 4.8 and >100μM, respectively. In contrast, ML-18 bound with lower affinity to the GRPR and NMBR with IC50 values of 16 and >100μM, respectively. ML-18 (16μM), but not its enantiomer EMY-98, inhibited the ability of 10nM BA1 to elevate cytosolic Ca(2+) in a reversible manner using lung cancer cells loaded with FURA2-AM. ML-18 (16μM), but not EMY-98, inhibited the ability of 100nM BA1 to cause tyrosine phosphorylation of the EGFR and ERK in lung cancer cells. ML-18 but not EMY-98 inhibited the proliferation of lung cancer cells. The results indicate that ML-18 is a nonpeptide BRS-3 antagonist that should serve as a template to improve potency and selectivity. PMID:25554218

  19. The atypical antipsychotic, olanzapine, potentiates ghrelin-induced receptor signaling: An in vitro study with cells expressing cloned human growth hormone secretagogue receptor.

    PubMed

    Tagami, Keita; Kashiwase, Yohei; Yokoyama, Akinobu; Nishimura, Hitomi; Miyano, Kanako; Suzuki, Masami; Shiraishi, Seiji; Matoba, Motohiro; Ohe, Yuichiro; Uezono, Yasuhito

    2016-08-01

    The growth hormone secretagogue receptor (GHS-R) belongs to Gαq-coupled G protein-coupled receptor (GPCR) that mediates growth hormone release, food intake, appetite, glucose metabolism and body composition. Ghrelin has been identified as an endogenous ligand for GHS-R, and it is the only orexigenic peptide found in the peripheral organs. Olanzapine, an atypical antipsychotic agent that binds to and inhibits the activation of GPCR for several neurotransmitters, has metabolic side effects such as excessive appetite and weight gain. Recently, studies have revealed that the orexigenic mechanism of olanzapine is mediated via GHS-R signaling, although the precise mechanisms have not been clarified. In this study, we investigated the effect of olanzapine on ghrelin-mediated GHS-R signaling by using an electrical impedance-based receptor biosensor assay system (CellKey™). Olanzapine at concentrations of 10(-7) and 10(-6)mol/L enhanced ghrelin-induced (10(-10)-10(-8)mol/L) GHS-R activation. A Ca(2+) imaging assay revealed that olanzapine (10(-7) and 10(-6)mol/L) enhanced ghrelin (10(-7) M)-induced GHS-R activity. In contrast, haloperidol (an antipsychotic agent) failed to enhance this ghrelin-mediated GHS-R activation, as demonstrated by both the CellKey™ and Ca(2+) imaging assays. Together, these results suggest that olanzapine, but not haloperidol, promotes appetite by enhancing ghrelin-mediated GHS-R signaling. PMID:26775231

  20. In Vitro and in Vivo Characterization of MOD-4023, a Long-Acting Carboxy-Terminal Peptide (CTP)-Modified Human Growth Hormone.

    PubMed

    Hershkovitz, Oren; Bar-Ilan, Ahuva; Guy, Rachel; Felikman, Yana; Moschcovich, Laura; Hwa, Vivian; Rosenfeld, Ron G; Fima, Eyal; Hart, Gili

    2016-02-01

    MOD-4023 is a novel long-acting version of human growth hormone (hGH), containing the carboxy-terminal peptide (CTP) of human chorionic gonadotropin (hCG). MOD-4023 is being developed as a treatment for adults and children with growth hormone deficiency (GHD), which would require fewer injections than currently available GH formulations and thus reduce patient discomfort and increase compliance. This study characterizes MOD-4023's binding affinities for the growth hormone receptor, as well as the pharmacokinetic and pharmacodynamics, toxicology, and safety profiles of repeated dosing of MOD-4023 in Sprague-Dawley rats and Rhesus monkeys. Although MOD-4023 exhibited reduced in vitro potency and lower affinity to the GH receptor than recombinant hGH (rhGH), administration of MOD-4023 every 5 days in rats and monkeys resulted in exposure comparable to daily rhGH, and the serum half-life of MOD-4023 was significantly longer. Repeated administration of MOD-4023 led to elevated levels of insulin-like growth factor 1 (IGF-1), and twice-weekly injections of MOD-4023 resulted in larger increase in weight gain with fewer injections and a lower accumulative hGH dose. Thus, the increased half-life of MOD-4023 in comparison to hGH may increase the frequency of protein-receptor interactions and compensate for its decreased in vitro potency. MOD-4023 was found to be well-tolerated in rats and monkeys, with minimal adverse events, suggesting an acceptable safety profile. These results provide a basis for the continued clinical development of MOD-4023 as a novel treatment of GHD in children and adults. PMID:26713839

  1. A composite demineralized bone matrix--self assembling peptide scaffold for enhancing cell and growth factor activity in bone marrow.

    PubMed

    Hou, Tianyong; Li, Zhiqiang; Luo, Fei; Xie, Zhao; Wu, Xuehui; Xing, Junchao; Dong, Shiwu; Xu, Jianzhong

    2014-07-01

    The need for suitable bone grafts is high; however, there are limitations to all current graft sources, such as limited availability, the invasive harvest procedure, insufficient osteoinductive properties, poor biocompatibility, ethical problems, and degradation properties. The lack of osteoinductive properties is a common problem. As an allogenic bone graft, demineralized bone matrix (DBM) can overcome issues such as limited sources and comorbidities caused by invasive harvest; however, DBM is not sufficiently osteoinductive. Bone marrow has been known to magnify osteoinductive components for bone reconstruction because it contains osteogenic cells and factors. Mesenchymal stem cells (MSCs) derived from bone marrow are the gold standard for cell seeding in tissue-engineered biomaterials for bone repair, and these cells have demonstrated beneficial effects. However, the associated high cost and the complicated procedures limit the use of tissue-engineered bone constructs. To easily enrich more osteogenic cells and factors to DBM by selective cell retention technology, DBM is modified by a nanoscale self-assembling peptide (SAP) to form a composite DBM/SAP scaffold. By decreasing the pore size and increasing the charge interaction, DBM/SAP scaffolds possess a much higher enriching yield for osteogenic cells and factors compared with DBM alone scaffolds. At the same time, SAP can build a cellular microenvironment for cell adhesion, proliferation, and differentiation that promotes bone reconstruction. As a result, a suitable bone graft fabricated by DBM/SAP scaffolds and bone marrow represents a new strategy and product for bone transplantation in the clinic. PMID:24755526

  2. Signaling from Glia and Cholinergic Neurons Controls Nutrient-Dependent Production of an Insulin-like Peptide for Drosophila Body Growth.

    PubMed

    Okamoto, Naoki; Nishimura, Takashi

    2015-11-01

    The insulin-like peptide (ILP) family plays key biological roles in the control of body growth. Although the functions of ILPs are well understood, the mechanisms by which organisms sense their nutrient status and thereby control ILP production remain largely unknown. Here, we show that signaling relay and feedback mechanisms control the nutrient-dependent expression of Drosophila ILP5 (Dilp5). The expression of dilp5 in brain insulin-producing cells (IPCs) is negatively regulated by the transcription factor FoxO. Glia-derived Dilp6 remotely regulates the FoxO activity in IPCs, primarily through Jeb secreted by cholinergic neurons. Dilp6 production by surface glia is amplified by cellular response to circulating Dilps derived from IPCs, in concert with amino acid signals. The induction of dilp5 is critical for sustaining body growth under restricted food conditions. These results provide a molecular framework that explains how the production of an endocrine hormone in a specific tissue is coordinated with environmental conditions. PMID:26555050

  3. Effects of oral chlortetracycline and dietary protein level on plasma concentrations of growth hormone and thyroid hormones in beef steers before and after challenge with a combination of thyrotropin-releasing hormone and growth hormone-releasing hormone.

    PubMed

    Rumsey, T S; McLeod, K; Elsasser, T H; Kahl, S; Baldwin, R L

    1999-08-01

    The objective of this study was to determine the effect of a subtherapeutic level of chlortetracycline (CTC) fed to growing beef steers under conditions of limited and adequate dietary protein on plasma concentrations of GH, thyroid-stimulating hormone (TSH), and thyroid hormones before and after an injection of thyrotropin-releasing hormone (TRH) + GHRH. Young beef steers (n = 32; average BW = 285 kg) were assigned to a 2x2 factorial arrangement of treatments of either a 10 or 13% crude protein diet (70% concentrate, 15% wheat straw, and 15% cottonseed hulls) and either a corn meal carrier or carrier + 350 mg of CTC daily top dressed on the diet. Steers were fed ad libitum amounts of diet for 56 d, and a jugular catheter was then placed in each steer in four groups (two steers from each treatment combination per group) during four consecutive days (one group per day). Each steer was injected via the jugular catheter with 1.0 microg/kg BW TRH + .1 microg/kg BW GHRH in 10 mL of saline at 0800. Blood samples were collected at -30, -15, 0, 5, 10, 15, 20, 30, 45, 60, 120, 240, and 360 min after releasing hormone injection. Plasma samples were analyzed for GH, TSH, thyroxine (T4), and triiodothyronine (T3). After 84 d on trial, the steers were slaughtered and the pituitary and samples of liver were collected and analyzed for 5'-deiodinase activity. Feeding CTC attenuated the GH response to releasing hormone challenge by 26% for both area under the response curve (P<.03) and peak response (P<.10). Likewise, CTC attenuated the TSH response to releasing hormone challenge for area under the response curve by 16% (P<.10) and peak response by 33% (P<.02), and attenuated the T4 response for area under the curve by 12% (P<.08) and peak response by 14% (P<.04). Type II deiodinase activity in the pituitary was 36% less (P<.02) in CTC-fed steers than in steers not fed CTC. The results of this study are interpreted to suggest that feeding subtherapeutic levels of CTC to young growing beef cattle attenuates the release of GH and TSH in response to pituitary releasing hormones, suggesting a mechanism by which CTC may influence tissue deposition in cattle. PMID:10461985

  4. A novel peptide sansalvamide analogue inhibits pancreatic cancer cell growth through G0/G1 cell-cycle arrest

    SciTech Connect

    Ujiki, Michael B. |; Milam, Ben; Ding Xianzhong |; Roginsky, Alexandra B.; Salabat, M. Reza; Talamonti, Mark S.; Bell, Richard H. |; Gu Wenxin; Silverman, Richard B. ||; Adrian, Thomas E. |. E-mail: tadrian@northwestern.edu

    2006-02-24

    Patients with pancreatic cancer have little hope for cure because no effective therapies are available. Sansalvamide A is a cyclic depsipeptide produced by a marine fungus. We investigated the effect of a novel sansalvamide A analogue on growth, cell-cycle phases, and induction of apoptosis in human pancreatic cancer cells in vitro. The sansalvamide analogue caused marked time- and concentration-dependent inhibition of DNA synthesis and cell proliferation of two human pancreatic cancer cell lines (AsPC-1 and S2-013). The analogue induced G0/G1 phase cell-cycle arrest and morphological changes suggesting induction of apoptosis. Apoptosis was confirmed by annexin V binding. This novel sansalvamide analogue inhibits growth of pancreatic cancer cells through G0/G1 arrest and induces apoptosis. Sansalvamide analogues may be valuable for the treatment of pancreatic cancer.

  5. Growth-inhibition effects of pacifastin-like peptides on a pest insect: the desert locust, Schistocerca gregaria.

    PubMed

    Spit, Jornt; Breugelmans, Bert; van Hoef, Vincent; Simonet, Gert; Zels, Sven; Broeck, Jozef Vanden

    2012-03-01

    The main reason for the varying degrees of success of peptidase inhibitors (PI) as biological insecticides is the existence of a poorly understood mechanism, which allows pest insects to compensate for PI present in their diet. To challenge this highly flexible physiological mechanism and to prolong the inhibitory effect of PI on insect growth, a number of measures were taken into account before and during experiments with a notorious pest insect, the desert locust, Schistocerca gregaria: (i) non-plant PI (pacifastin-related inhibitors) were used to reduce the risk of a specific co-evolutionary adaptation of the pest insect, (ii) based on the main types of digestive enzymes present in the midgut, mixtures of multiple PI with different enzyme specificity were selected, allowing for a maximal inhibition of the proteolytic activity and (iii) digestive peptidase samples were taken during oral administration experiments to study compensatory mechanisms. Contrary to larvae fed on a diet containing plant-derived PI, a significant growth impediment was observed in larvae that were fed a mixture of different pacifastin-like PI. Nevertheless, the growth inhibition effect of this PI mixture attenuated after a few days, Moreover, a comprehensive study of the observed responses after oral administration of PI revealed that S. gregaria larvae can adjust their secreted digestive enzyme activities in two distinct ways depending on the composition/concentration of the PI-mixture. PMID:21736908

  6. Production and characterization of recombinantly derived peptides and antibodies for accurate determinations of somatolactin, growth hormone and insulin-like growth factor-I in European sea bass (Dicentrarchus labrax).

    PubMed

    de Celis, S Vega-Rubín; Gómez-Requeni, P; Pérez-Sánchez, J

    2004-12-01

    A specific radioimmunoassay (RIA) for European sea bass (Dicentrarchus labrax) growth hormone (GH) was developed and validated. For this purpose, a stable source of GH was produced by means of recombinant DNA technology in a bacteria system. The identity of the purified protein (ion exchange chromatography) was demonstrated by Western blot and a specific GH antiserum was raised in rabbit. In Western blot and RIA system, this antiserum recognized specifically native and recombinant GH, and it did not cross-react with fish prolactin (PRL) and somatolactin (SL). In a similar way, a specific polyclonal antiserum against the now available recombinant European sea bass SL was raised and used in the RIA system to a sensitivity of 0.3 ng/ml (90% of binding of tracer). Further, European sea bass insulin-like growth factor-I (IGF-I) was cloned and sequenced, and its high degree of identity with IGF-I peptides of barramundi, tuna, and sparid fish allowed the use of a commercial IGF-I RIA based on barramundi IGF-I antiserum. These assay tools assisted for the first time accurate determinations of SL and GH-IGF-I axis activity in a fish species of the Moronidae family. Data values were compared to those found with gilthead sea bream (Sparus aurata), which is currently used as a Mediterranean fish model for growth endocrinology studies. As a characteristic feature, the average concentration year round of circulating GH in growing mature males of European sea bass was higher than in gilthead sea bream. By contrast, the average concentration of circulating SL was lower. Concerning to circulating concentration of IGF-I, the measured plasma values for a given growth rate were also lower in European sea bass. These findings are discussed on the basis of a different energy status that might allowed a reduced but more continuous growth in European sea bass. PMID:15560873

  7. Diverse CLE peptides from cyst nematode species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant CLAVATA3/ESR (CLE)-like peptides play diverse roles in plant growth and development including maintenance of the stem cell population in the root meristem. Small secreted peptides sharing similarity to plant CLE signaling peptides have been isolated from several cyst nematode species including...

  8. Administration of insulin-like growth factor-I (IGF-I) peptides for three days stimulates proliferation of the small intestinal epithelium in rats.

    PubMed Central

    Steeb, C B; Trahair, J F; Read, L C

    1995-01-01

    It has previously been shown that longterm administration of insulin-like growth factor-I (IGF-I) or the analogue Long R3 IGF-I (LR3IGF-I) selectively stimulate growth of the gastrointestinal tract in gut resected, dexamethasone treated, and normal rats. In this study, the short-term effects of IGF-I administration on intestinal proliferation have been investigated. Female rats (110 g, five-six/group) were infused for three days with 2.5 mg/kg/day of either IGF-I or LR3IGF-I and compared with vehicle treated or untreated control rats. LR3IGF-I but not IGF-I increased body weight and wet tissue weight of the small and large intestine (+20%), compared with controls. Tissue weight responses were independent of food intake and were reflected in the histology of the tissue. In LR3IGF-I treated animals, duodenal and ileal crypts length were increased by 13 and 22%, respectively, associated with an increase in crypt cell number. No such histological changes were seen in IGF-I treated rats. Tritiated thymidine labelling indices were significantly increased after administration of either IGF-I or LR3IGF-I (up to 14%) in both the duodenum and ileum. In IGF-I treated rats, increased nuclear labelling was not associated with an increase in the crypt compartment. In contrast, LR3IGF-I induced proportional increments in thymidine labelling and crypt size, suggesting that LR3IGF-I is not only more potent than the native peptide but also induced proliferative events more rapidly. In the colon, the thymidine labelling index was low, however, a non-significant increase in the number of cells labelled with thymidine was seen. These results suggest that within a three day treatment period intestinal mitogenesis is more advanced in animals treated with LR3IGF-I. The differences in proliferative response between the two peptides may be accounted for by variations in pharmacokinetics, clearance rates, and interactions with circulating and tissue specific binding proteins. PMID:8549937

  9. Administration of insulin-like growth factor-I (IGF-I) peptides for three days stimulates proliferation of the small intestinal epithelium in rats.

    PubMed

    Steeb, C B; Trahair, J F; Read, L C

    1995-11-01

    It has previously been shown that longterm administration of insulin-like growth factor-I (IGF-I) or the analogue Long R3 IGF-I (LR3IGF-I) selectively stimulate growth of the gastrointestinal tract in gut resected, dexamethasone treated, and normal rats. In this study, the short-term effects of IGF-I administration on intestinal proliferation have been investigated. Female rats (110 g, five-six/group) were infused for three days with 2.5 mg/kg/day of either IGF-I or LR3IGF-I and compared with vehicle treated or untreated control rats. LR3IGF-I but not IGF-I increased body weight and wet tissue weight of the small and large intestine (+20%), compared with controls. Tissue weight responses were independent of food intake and were reflected in the histology of the tissue. In LR3IGF-I treated animals, duodenal and ileal crypts length were increased by 13 and 22%, respectively, associated with an increase in crypt cell number. No such histological changes were seen in IGF-I treated rats. Tritiated thymidine labelling indices were significantly increased after administration of either IGF-I or LR3IGF-I (up to 14%) in both the duodenum and ileum. In IGF-I treated rats, increased nuclear labelling was not associated with an increase in the crypt compartment. In contrast, LR3IGF-I induced proportional increments in thymidine labelling and crypt size, suggesting that LR3IGF-I is not only more potent than the native peptide but also induced proliferative events more rapidly. In the colon, the thymidine labelling index was low, however, a non-significant increase in the number of cells labelled with thymidine was seen. These results suggest that within a three day treatment period intestinal mitogenesis is more advanced in animals treated with LR3IGF-I. The differences in proliferative response between the two peptides may be accounted for by variations in pharmacokinetics, clearance rates, and interactions with circulating and tissue specific binding proteins. PMID:8549937

  10. Roles of aromatic side chains and template effects of the hydrophobic cavity of a self-assembled peptide nanoarchitecture for anisotropic growth of gold nanocrystals.

    PubMed

    Tomizaki, Kin-ya; Kishioka, Kohei; Kobayashi, Hiroki; Kobayashi, Akitsugu; Yamada, Naoki; Kataoka, Shunsuke; Imai, Takahito; Kasuno, Megumi

    2015-11-15

    Gold nanocrystals are promising as catalysts and for use in sensing/imaging systems, photonic/plasmonic devices, electronics, drug delivery systems, and for photothermal therapy due to their unique physical, chemical, and biocompatible properties. The use of various organic templates allows control of the size, shape, structure, surface modification and topology of gold nanocrystals; in particular, currently the synthesis of gold nanorods requires a cytotoxic surfactant to control morphology. To control the shape of gold nanocrystals, we previously demonstrated the de novo design and synthesis of a β-sheet-forming nonapeptide (RU006: Ac-AIAKAXKIA-NH2, X=L-2-naphthylalanine, Nal) and the fabrication of gold nanocrystals by mixing RU006 and HAuCl4 in water. The reaction afforded ultrathin gold nanoribbons 50-100 nm wide, several nanometers high, and microns long. To understand the mechanism underlying gold nanoribbon formation by the RU006 system, we here report (i) the effects of replacement of the Nal aromatic side chain in the RU006 sequence with other aromatic moieties, (ii) the electrochemical properties of aromatic side chains in the de novo designed template peptides to estimate the redox potential and number of electrons participating in the gold crystallization process, and (iii) the stoichiometry of the RU006 system for gold nanoribbon synthesis. Interestingly, RU006 bearing a naphthalene moiety (oxidation peak potential of 1.50 V vs Ag/Ag(+)) and an analog [Ant(6)]-RU006 bearing a bulky anthracene moiety (oxidation peak potential of 1.05 V vs Ag/Ag(+)) allowed the growth of anisotropic (ribbon-like) and isotropic (round) gold nanocrystals, respectively. This trend in morphology of gold nanocrystals was attributed to spatially-arranged hydrophobic cavities sufficiently large to accommodate the gold precursor and to allow directed crystal growth driven by cross-linking reactions among the naphthalene rings. Support for this mechanism was obtained by

  11. Synthetic antimicrobial peptide design.

    PubMed

    Powell, W A; Catranis, C M; Maynard, C A

    1995-01-01

    To guide the design of potential plant pathogen-resistance genes, synthetic variants of naturally occurring antimicrobial gene products were evaluated. Five 20-amino acid (ESF1, ESF4, ESF5, ESF6, ESF13), one 18-amino acid (ESF12), and one 17-amino acid (ESF17) amphipathic peptide sequences were designed, synthesized, and tested with in vitro bioassays. Positive charges on the hydrophilic side of the peptide were shown to be essential for antifungal activity, yet the number of positive charges could be varied with little or no change in activity. The size could be reduced to 18 amino acids, but at 17 amino acids a significant reduction in activity was observed. ESF1, 5, 6, and 12 peptides were inhibitory to the germination of conidia from Cryphonectria parasitica, Fusarium oxysporum f. sp. lycopersici, and Septoria musiva but did not inhibit the germination of pollen from Castanea mollissima and Salix lucida. ESF12 also had no effect on the germination of Malus sylvestris and Lycopersicon esculentum pollen, but inhibited the growth of the bacteria Agrobacterium tumefaciens, Erwinia amylovora, and Pseudomonas syringae. The minimal inhibitory concentrations of the active ESF peptides were similar to those of the naturally occurring control peptides, magainin II and cecropin B. The significant differential in sensitivity between the microbes and plant cells indicated that the active ESF peptides are potentially useful models for designing plant pathogen-resistance genes. PMID:7579625

  12. Perspectives and Peptides of the Next Generation

    NASA Astrophysics Data System (ADS)

    Brogden, Kim A.

    Shortly after their discovery, antimicrobial peptides from prokaryotes and eukaryotes were recognized as the next potential generation of pharmaceuticals to treat antibiotic-resistant bacterial infections and septic shock, to preserve food, or to sanitize surfaces. Initial research focused on identifying the spectrum of antimicrobial agents, determining the range of antimicrobial activities against bacterial, fungal, and viral pathogens, and assessing the antimicrobial activity of synthetic peptides versus their natural counterparts. Subsequent research then focused on the mechanisms of antimicrobial peptide activity in model membrane systems not only to identify the mechanisms of antimicrobial peptide activity in microorganisms but also to discern differences in cytotoxicity for prokaryotic and eukaryotic cells. Recent, contemporary work now focuses on current and future efforts to construct hybrid peptides, peptide congeners, stabilized peptides, peptide conjugates, and immobilized peptides for unique and specific applications to control the growth of microorganisms in vitro and in vivo.

  13. Stability analysis of an inline peptide-based conjugate for metal delivery: nickel(II)-claMP Tag epidermal growth factor as a model system.

    PubMed

    Mills, Brittney J; Laurence, Jennifer S

    2015-02-01

    Metals are a key component of many diagnostic imaging and biotechnology applications, and the majority of cancer patients receive a platinum-based drug as part of their treatment. Significant effort has been devoted to developing tight binding synthetic chelators to enable effective targeted delivery of metal-based conjugates, with most successes involving lanthanides rather than transition metals for diagnostic imaging. Chemical conjugation modifies the protein's properties and generates a heterogeneous mixture of products. Chelator attachment is typically carried out by converting the amino group on lysines to an amide, which can impact the stability and solubility of the targeting protein and these properties vary among the set of individual conjugate species. Site-specific attachment is sought to reduce complexity and control stability. Here, the metal abstraction peptide technology was applied to create the claMP Tag, an inline platform for generating site-specific conjugates involving transition metals. The claMP Tag was genetically encoded into epidermal growth factor (EGF) and loaded with nickel(II) as a model system to demonstrate that the tag within the homogeneous inline conjugate presents sufficient solution stability to enable biotechnology applications. The structure and disulfide network of the protein and chemical stability of the claMP Tag and EGF components were characterized. PMID:25212829

  14. Powerful anti-tumor and anti-angiogenic activity of a new anti-vascular endothelial growth factor receptor 1 peptide in colorectal cancer models.

    PubMed

    Cicatiello, Valeria; Apicella, Ivana; Tudisco, Laura; Tarallo, Valeria; Formisano, Luigi; Sandomenico, Annamaria; Kim, Younghee; Bastos-Carvalho, Ana; Orlandi, Augusto; Ambati, Jayakrishna; Ruvo, Menotti; Bianco, Roberto; De Falco, Sandro

    2015-04-30

    To assess the therapeutic outcome of selective block of VEGFR1, we have evaluated the activity of a new specific antagonist of VEGFR1, named iVR1 (inhibitor of VEGFR1), in syngenic and xenograft colorectal cancer models, in an artificial model of metastatization, and in laser-induced choroid neovascularization. iVR1 inhibited tumor growth and neoangiogenesis in both models of colorectal cancer, with an extent similar to that of bevacizumab, a monoclonal antibody anti-VEGF-A. It potently inhibited VEGFR1 phosphorylation in vivo, determining a strong inhibition of the recruitment of monocyte-macrophages and of mural cells as confirmed, in vitro, by the ability to inhibit macrophages migration. iVR1 was able to synergize with irinotecan determining a shrinkage of tumors that became undetectable after three weeks of combined treatment. Such treatment induced a significant prolongation of survival similar to that observed with bevacizumab and irinotecan combination. iVR1 also fully prevented lung invasion by HCT-116 cells injected in mouse tail vein. Also, iVR1 impressively inhibited choroid neovascularization after a single intravitreal injection. Collectively, data showed the strong potential of iVR1 peptide as a new anti-tumor and anti-metastatic agent and demonstrate the high flexibility of VEGFR1 antagonists as therapeutic anti-angiogenic agents in different pathological contexts. PMID:25868854

  15. Immobilizing osteogenic growth peptide with and without fibronectin on a titanium surface: effects of loading methods on mesenchymal stem cell differentiation

    PubMed Central

    Chen, Cen; Li, Han; Kong, Xiangdong; Zhang, Sheng-Min; Lee, In-Seop

    2015-01-01

    In this study, to improve the osseointegration of implants, osteogenic growth peptide (OGP) and fibronectin (FN) were loaded within mineral, which was formed on titanium, through adsorption and coprecipitation methods. The release profiles of OGP loaded by either adsorption or coprecipitation and the effects of the loading methods to immobilize OGP with and without FN on rat mesenchymal stem cell (rMSC) osteogenic differentiation were studied. The coprecipitation approach slightly reduced the initial burst release, while the adsorption approach provided a more sustained release. Dual loading of OGP and FN further improved cell attachments compared with either OGP or FN alone. Dually loaded OGP and FN also had a positive impact on rMSC proliferation and osteogenic differentiation. The difference in methods of loading OGP with and without FN also had some effects on osteogenic differentiation. Compared with coprecipitated OGP alone, adsorbed OGP enhanced later differentiation, such as osteocalcin secretion and matrix mineralization. Simultaneously adsorbed OGP and FN led to higher proliferation and higher osteogenic differentiation in both early and late stages compared with sequentially loaded OGP and FN. rMSC culture clearly indicated that simultaneously adsorbed OGP and FN could improve osseointegration, and this treatment represents a potential method for effective surface modification of dental and orthopedic implants. PMID:25678785

  16. Insulin-like growth factor II peptide fusion enables uptake and lysosomal delivery of α-N-acetylglucosaminidase to mucopolysaccharidosis type IIIB fibroblasts

    PubMed Central

    Kan, Shih-hsin; Troitskaya, Larisa A.; Sinow, Carolyn S.; Haitz, Karyn; Todd, Amanda K.; Di Stefano, Ariana; Le, Steven Q.; Dickson, Patricia I.; Tippin, Brigette L.

    2014-01-01

    Enzyme replacement therapy for mucopolysaccharidosis type IIIB (MPS IIIB; Sanfilippo B syndrome) has been hindered by inadequate mannose 6-phosphorylation and cellular uptake of recombinantly produced human α-N-acetyl-glucosamindase (rhNAGLU). We expressed and characterized a modified, recombinant human NAGLU fused to the receptor binding motif of insulin-like growth factor-II (rhNAGLU-IGF-II) to enhance its ability to enter cells using the cation-independent mannose 6-phosphate receptor, which is also the receptor for IGF-II (at a different binding site). RhNAGLU-IGF-II was stably expressed in Chinese hamster ovary cells, secreted and purified to apparent homogeneity. The Km and pH optimum of the fusion enzyme was similar to those reported for rhNAGLU. Both intracellular uptake and confocal microscopy suggested MPS IIIB fibroblasts readily take up the fusion enzyme via receptor-mediated endocytosis that was significantly inhibited (p<0.001) by monomeric IGF-II peptide. Glycosaminoglycan storage was reduced by 60% (p<0.001) to near background levels in MPS IIIB cells after treatment with rhNAGLU-IGF-II, with half-maximal correction at concentrations of 3–12 pM. Similar cellular uptake mechanism via the IGF-II receptor was also demonstrated in two different brain tumor-derived cell lines. Fusion of NAGLU to IGF-II enhanced its cellular uptake while maintaining enzymatic activity, supporting its potential as a therapeutic candidate for MPS IIIB. PMID:24266751

  17. Protection of SK-N-MC cells against β-amyloid peptide-induced degeneration using neuron growth factor-loaded liposomes with surface lactoferrin.

    PubMed

    Kuo, Yung-Chih; Wang, Cheng-Ting

    2014-07-01

    A liposomal system with surface lactoferrin (Lf) was developed for delivering neuron growth factor (NGF) across the blood-brain barrier (BBB) and improving the viability of neuron-like SK-N-MC cells with deposited β-amyloid peptide (Aβ). The Lf-grafted liposomes carrying NGF (Lf/NGF-liposomes) were applied to a monolayer of human brain-microvascular endothelial cells (HBMECs) regulated by human astrocytes (HAs) and to fibrillar Aβ1-42-insulted SK-N-MC cells. An increase in cholesterol mole percentage enhanced the particle size, absolute value of zeta potential, and physical stability, however, reduced the entrapment efficiency and release rate of NGF. In addition, an increase in Lf concentration increased the particle size, surface nitrogen percentage, NGF permeability across the BBB, and viability of HBMECs, HAs, and SK-N-MC cells, however, decreased the absolute value of zeta potential, surface phosphorus percentage, and loading efficiency of Lf. After treating with Lf/NGF-liposomes, a higher Aβ concentration yielded a lower survival of SK-N-MC cells. The current Lf/NGF-liposomes are efficacious drug carriers to target the BBB and inhibit the Aβ-induced neurotoxicity as potential pharmacotherapy for Alzheimer's disease. PMID:24746790

  18. In situ immobilization of proteins and RGD peptide on polyurethane surfaces via poly(ethylene oxide) coupling polymers for human endothelial cell growth.

    PubMed

    Wang, Dong-an; Ji, Jian; Sun, Yong-hong; Shen, Jia-cong; Feng, Lin-xian; Elisseeff, Jennifer H

    2002-01-01

    A "CBABC"-type pentablock coupling polymer, mesylMPEO, was designed and synthesized to promote human endothelial cell growth on the surfaces of polyurethane biomaterials. The polymer was composed of a central 4,4'-methylenediphenyl diisocyanate (MDI) coupling unit and poly(ethylene oxide) (PEO) spacer arms with methanesulfonyl (mesyl) end groups pendent on both ends. As the presurface modifying additive (pre-SMA), the mesylMPEO was noncovalently introduced onto the poly(ether urethane) (PEU) surfaces by dip coating, upon which the protein/peptide factors (gelatin, albumin, and arginine-glycine-aspartic acid tripeptide [RGD]) were covalently immobilized in situ by cleavage of the original mesyl end groups. The pre-SMA synthesis and PEU surface modification were characterized using nuclear magnetic resonance spectroscopy ((1)H NMR), attenuated total reflection infrared spectroscopy (ATR-FTIR), and X-ray photoelectron spectroscopy (XPS). Human umbilical vein endothelial cells (HUVEC) were harvested manually by collagenase digestion and seeded on the modified PEU surfaces. Cell adhesion ratios (CAR) and cell proliferation ratios (CPR) were measured using flow cytometry, and the individual cell viability (ICV) was determined by MTT assay. The cell morphologies were investigated by optical inverted microscopy (OIM) and scanning electrical microscopy (SEM). The gelatin- and RGD-modified surfaces were HUVEC-compatible and promoted HUVEC growth. The albumin-modified surfaces were compatible but inhibited cell adhesion. The results also indicated that, for HUVEC in vitro cultivation, the cell adhesion stage was of particular importance and had a significant impact on the cell responses to the modified surfaces. PMID:12425667

  19. Targeted delivery of cisplatin by LHRH-peptide conjugated dextran nanoparticles suppresses breast cancer growth and metastasis.

    PubMed

    Li, Mingqiang; Tang, Zhaohui; Zhang, Yu; Lv, Shixian; Li, Quanshun; Chen, Xuesi

    2015-05-01

    The metastasis of breast cancer is the leading cause of cancer death in women. In this work, an attempt to simultaneously inhibit the primary tumor growth and organ-specific metastasis by the cisplatin-loaded LHRH-modified dextran nanoparticles (Dex-SA-CDDP-LHRH) was performed in the 4T1 orthotopic mammary tumor metastasis model. With the rationally designed conjugation site of the LHRH ligand, the Dex-SA-CDDP-LHRH nanoparticles maintained the targeting function of LHRH and specifically bound to the LHRH-receptors overexpressed on the surface of 4T1 breast cancer cells. Therefore, the Dex-SA-CDDP-LHRH nanoparticles exhibited improved cellular uptake and promoted cytotoxicity, when compared with the non-targeted Dex-SA-CDDP nanoparticles. Moreover, both the non-targeted and targeted nanoparticles significantly decreased the systemic toxicity of CDDP and increased the maximum tolerated dose of CDDP from 4 to 30mgkg(-1). Importantly, Dex-SA-CDDP-LHRH markedly enhanced the accumulation of CDDP in the injected primary tumor and metastasis-containing organs, and meanwhile significantly reduced the nephrotoxicity of CDDP. Dose-dependent therapeutic effects further demonstrated that the CDDP-loaded LHRH-decorated polysaccharide nanoparticles significantly enhanced the antitumor and antimetastasis efficacy, as compared to the non-targeted nanoparticles. These results suggest that Dex-SA-CDDP-LHRH nanoparticles show great potential for targeted chemotherapy of metastatic breast cancer. PMID:25735801

  20. Inhibition of Stat3 by peptide aptamer rS3-PA enhances growth suppressive effects of irinotecan on colorectal cancer cells.

    PubMed

    Weber, Axel; Borghouts, Corina; Delis, Natalia; Mack, Laura; Brill, Boris; Bernard, Anne-Charlotte; Coqueret, Olivier; Groner, Bernd

    2012-06-01

    Abstract Cytotoxic agents, alone or in combination, are being used in the treatment of colorectal cancer. Despite progress in the therapeutic regimes, this common malignancy is still the cause of considerable morbidity and mortality, and further improvements are required. Cancer cells often exhibit intrinsic resistance against chemotherapeutic agents or they develop resistance over the time of treatment. Several mechanisms have been made responsible, e.g., drugs may fail to reach tumor cells or drugs may fail to elicit cytotoxicity. The molecular characterization of drug resistance in cancer cells may lead to strategies to overcome it and enhance the sensitivity to chemotherapy. Irinotecan is one of the main treatments of colorectal cancer; it is converted into its active metabolite SN38 and acts as a topoisomerase I inhibitor. Inhibition of this enzyme prevents DNA relegation following uncoiling. Irinotecan has been used as a chemotherapeutic agent either as a single agent or in combination with 5-fluorouracil and targeted therapies directed against the epidermal growth factor receptor, such as cetuximab. The transcription factor signal transducer and activator of transcription 3 (Stat3) is a member of the signal transducer and activator of transcription protein family. Its persistent activation is found in tumor cells and has been associated with drug and radiation resistance. The treatment of colorectal cancer cells with irinotecan leads to senescence or apoptosis following DNA double-strand break induction. This process is impaired by the activation of Stat3. We have derived a Stat3 specific peptide aptamer [recombinant Stat3 inhibitory peptide aptamer (rS3-PA)] that recognizes the dimerization domain of Stat3 and effectively inhibits its function. The delivery of rS3-PA into colon cancer cells and the resulting inhibition of Stat3 strongly enhanced the cytotoxic action of SN38. These data show that the targeted inhibition of Stat3 decreases drug resistance and

  1. A novel ligand-independent peptide inhibitor of TREM-1 suppresses tumor growth in human lung cancer xenografts and prolongs survival of mice with lipopolysaccharide-induced septic shock

    PubMed Central

    Sigalov, Alexander B.

    2014-01-01

    Triggering receptor expressed on myeloid cells-1 (TREM-1) amplifies the inflammatory response and plays a role in cancer and sepsis. Inhibition of TREM-1 by short hairpin RNA (shRNA) in macrophages suppresses cancer cell invasion in vitro. In the clinical setting, high levels of TREM-1 expression on tumor-associated macrophages are associated with cancer recurrence and poor survival of patients with non-small cell lung cancer (NSCLC). TREM-1 upregulation on peritoneal neutrophils has been found in human sepsis patients and in mice with experimental lipopolysaccharide (LPS)-induced septic shock. However, the precise function of TREM-1 and the nature of its ligand are not yet known. In this study, we used the signaling chain homooligomerization (SCHOOL) model of immune signaling to design a novel, ligand-independent peptide-based TREM-1 inhibitor and demonstrated that this peptide specifically silences TREM-1 signaling in vitro and in vivo. Utilizing two human lung tumor xenograft nude mouse models (H292 and A549) and mice with LPS-induced sepsis, we show for the first time that blockade of TREM-1 function using non-toxic and non-immunogenic SCHOOL peptide inhibitors: 1) delays tumor growth in xenograft models of human NSCLC, 2) prolongs survival of mice with LPS-induced septic shock, and 3) substantially decreases cytokine production in vitro and in vivo. In addition, targeted delivery of SCHOOL peptides to macrophages utilizing lipoprotein-mimicking nanoparticles significantly increased peptide half-life and dosage efficacy. Together, the results suggest that ligand-independent modulation of TREM-1 function using small synthetic peptides might be a suitable treatment for sepsis and NSCLC and possibly other types of inflammation-associated disorders. PMID:24836682

  2. Peptide identification

    DOEpatents

    Jarman, Kristin H [Richland, WA; Cannon, William R [Richland, WA; Jarman, Kenneth D [Richland, WA; Heredia-Langner, Alejandro [Richland, WA

    2011-07-12

    Peptides are identified from a list of candidates using collision-induced dissociation tandem mass spectrometry data. A probabilistic model for the occurrence of spectral peaks corresponding to frequently observed partial peptide fragment ions is applied. As part of the identification procedure, a probability score is produced that indicates the likelihood of any given candidate being the correct match. The statistical significance of the score is known without necessarily having reference to the actual identity of the peptide. In one form of the invention, a genetic algorithm is applied to candidate peptides using an objective function that takes into account the number of shifted peaks appearing in the candidate spectrum relative to the test spectrum.

  3. Minimal essential length of Clostridium botulinum C3 peptides to enhance neuronal regenerative growth and connectivity in a non-enzymatic mode.

    PubMed

    Loske, Peter; Boato, Francesco; Hendrix, Sven; Piepgras, Johannes; Just, Ingo; Ahnert-Hilger, Gudrun; Höltje, Markus

    2012-03-01

    C3 ADP-ribosyltransferase is a valuable tool to study Rho-dependent cellular processes. In the current study we investigated the impact of enzyme-deficient peptides derived from Clostridium botulinum C3 transferase in the context of neuronal process elongation and branching, synaptic connectivity, and putative beneficial effects on functional outcome following traumatic injury to the CNS. By screening a range of peptidic fragments, we identified three short peptides from C3bot that promoted axon and dendrite outgrowth in cultivated hippocampal neurons. Furthermore, one of these fragments, a 26-amino acid peptide covering the residues 156-181 enhanced synaptic connectivity in primary hippocampal culture. This peptide was also effective to foster axon outgrowth and re-innervation in organotypical brain slice culture. To evaluate the potential of the 26mer to foster repair mechanisms after CNS injury we applied this peptide to mice subjected to spinal cord injury by either compression impact or hemisection. A single local administration at the site of the lesion improved locomotor recovery. In addition, histological analysis revealed an increased serotonergic input to lumbar motoneurons in treated compared with control mice. Pull-down assays showed that lesion-induced up-regulation of RhoA activity within the spinal cord was largely blocked by C3bot peptides despite the lack of enzymatic activity. PMID:22239108

  4. Identification of multifunctional peptides from human milk.

    PubMed

    Mandal, Santi M; Bharti, Rashmi; Porto, William F; Gauri, Samiran S; Mandal, Mahitosh; Franco, Octavio L; Ghosh, Ananta K

    2014-06-01

    Pharmaceutical industries have renewed interest in screening multifunctional bioactive peptides as a marketable product in health care applications. In this context, several animal and plant peptides with potential bioactivity have been reported. Milk proteins and peptides have received much attention as a source of health-enhancing components to be incorporated into nutraceuticals and functional foods. By using this source, 24 peptides have been fractionated and purified from human milk using RP-HPLC. Multifunctional roles including antimicrobial, antioxidant and growth stimulating activity have been evaluated in all 24 fractions. Nevertheless, only four fractions show multiple combined activities among them. Using a proteomic approach, two of these four peptides have been identified as lactoferrin derived peptide and kappa casein short chain peptide. Lactoferrin derived peptide (f8) is arginine-rich and kappa casein derived (f12) peptide is proline-rich. Both peptides (f8 and f12) showed antimicrobial activities against both Gram-positive and Gram-negative bacteria. Fraction 8 (f8) exhibits growth stimulating activity in 3T3 cell line and f12 shows higher free radical scavenging activity in comparison to other fractions. Finally, both peptides were in silico evaluated and some insights into their mechanism of action were provided. Thus, results indicate that these identified peptides have multiple biological activities which are valuable for the quick development of the neonate and may be considered as potential biotechnological products for nutraceutical industry. PMID:24703967

  5. Transforming Growth Factor-β1 Antagonizes the Transcription, Expression, and Vascular Signaling of Guanylyl Cyclase/Natriuretic Peptide Receptor A: Role of δEF1

    PubMed Central

    Sen, Anagha; Kumar, Prerna; Garg, Renu; Lindsey, Sarah H.; Katakam, Prasad V.G.; Bloodworth, Meaghan; Pandey, Kailash N.

    2016-01-01

    The objective of this study was to determine the role of transforming growth factor-beta 1 (TGF-β1) in transcriptional regulation and function of guanylyl cyclase-A/natriuretic peptide receptor-A (GC-A/NPRA) gene (Npr1) and whether a cross-talk exists between these two hormonal systems in target cells. After treatments of primary cultured rat thoracic aortic vascular smooth muscle cells (RTASMCs) and mouse mesangial cells (MMCs) with TGF-β1, the Npr1 promoter construct embodying delta-crystallin enhancer binding factor 1 (δEF1) site showed 85% reduction in luciferase activity in a time- and dose-dependent manner. TGF-β1 also significantly attenuated luciferase activity of Npr1 promoter by 62% and decreased the ANP-mediated relaxation of mouse denuded aortic rings ex vivo. Treatment of cells with TGF-β1, stimulated the protein levels of δEF1 by 2.4- to 2.8-fold and also significantly enhanced the phosphorylation of Smad 2/3; however, markedly reduced Npr1 mRNA and receptor protein levels. Overexpression of δEF1 showed a reduction in Npr1 promoter activity by 75% while the deletion or site-directed mutagenesis of δEF1 sites in Npr1 promoter, eliminated the TGF-β1-mediated repression of Npr1 transcription. TGF-β1 significantly increased the expression of α-smooth muscle actin and collagen type 1 alpha 2 in RTASMCs, which were markedly attenuated by ANP in NPRA overexpressing cells. Together, the present results suggest that an antagonistic cascade exists between TGF-β1/Smad/δEF1 pathways and Npr1 expression and receptor signaling relevant to renal and vascular remodeling, which might be critical in the regulation of blood pressure and cardiovascular homeostasis. PMID:26934489

  6. Growth-differentiation factor-15, endoglin and N-terminal pro-brain natriuretic peptide induction in athletes participating in an ultramarathon foot race.

    PubMed

    Tchou, Isabelle; Margeli, Alexandra; Tsironi, Maria; Skenderi, Katerina; Barnet, Marc; Kanaka-Gantenbein, Christina; Papassotiriou, Ioannis; Beris, Photis

    2009-09-01

    We investigated the actions of growth-differentiation factor (GDF)-15, endoglin and N-terminal pro-brain natriuretic peptide (NT-pro-BNP) in 15 male athletes who participated in the ultradistance foot race of the 246 km 'Sparthathlon'. Measurements were performed before (phase I), at the end of the race (phase II) and 48 h post-race (phase III). GDF-15 and endoglin serum concentrations were determined with enzyme-linked immunosorbent assay and NT-pro-BNP plasma levels by electrochemiluminescence. GDF-15 levels were increased from phase I (563.9 +/- 57.1 pg ml(-1)) to phase II (2311.1 +/- 462.3 pg ml(-1)) and decreased at phase III (862.0 +/- 158.0 pg ml(-1)) (p < 0.0002). NT-pro-BNP levels followed a similar pattern to that of GDF-15 from 38.1 +/- 4.8 pg ml(-1) at phase I to 1280.6 +/- 259.0 pg ml(-1) at phase II and 89.8 +/- 13.6 pg ml(-1) at phase III (p < 0.0001) and at the same time points, endoglin levels were 4.7 +/- 0.2 ng ml(-1) at phase I, 5.8 +/- 0.2 ng ml(-1) at phase II and 4.3 +/- 0.2 ng ml(-1) at phase III (p < 0.002). These findings indicate that circulating GDF-15, endoglin and NT-pro-BNP levels reflect a transient endothelial dysfunction in these athletes who participated in a foot race consisting of continuous, prolonged and brisk exercise. PMID:19563304

  7. Transforming growth factor beta (TGFB) signaling is activated during porcine implantation: proposed role for latency-associated peptide interactions with integrins at the conceptus-maternal interface.

    PubMed

    Massuto, Dana A; Kneese, Eric C; Johnson, Gregory A; Burghardt, Robert C; Hooper, R Neil; Ing, Nancy H; Jaeger, Laurie A

    2010-02-01

    The process of implantation is mediated by a complex network of signaling and adhesive factors. In the pig, latent and active transforming growth factor beta (TGFB), TGFB receptors (TGFBR), and integrins (ITGs) are present during the peri-implantation period. TGFB signals via TGFBR and activates downstream effector SMAD proteins 2 and 3 (p-SMAD2/3). Latency-associated peptide (LAP), part of the latent TGFB complex, is known to bind to ITG heterodimers and activate TGFB. We hypothesize that active TGFBs and TGFBRs along with LAP and ITGs functionally interact at the conceptus-maternal interface to mediate events essential for conceptus development and attachment in pigs. Uteri and conceptuses from days 10, 12, 16, 20, and 24 pregnant gilts were immunostained for TGFB, LAP, and ITG subunits (ITGAV, ITGB1, ITGB3, ITGB5, ITGB6, and ITGB8). Activation of TGFBRs was evaluated by the presence of phosphorylated downstream effector SMAD2/3. Binding of LAP to ITGs was also evaluated using porcine trophectoderm cells. Abundant active TGFB was detected at the apical surfaces of epithelia at the conceptus-maternal interface, and p-SMAD2/3 was detected at both conceptus attachment and nonattachment sites during implantation. Separate aggregates of LAP, ITGB1, ITGB5, and later ITGB3 were detected at the porcine conceptus-maternal interface, and binding of LAP to ITGs on apical surfaces was demonstrated. Results suggest that functional LAP-ITG adhesion complexes support conceptus attachment and promote TGFB activation leading to TGFB interaction with TGFBR supporting events of porcine implantation. PMID:19920116

  8. Totally synthetic peptide-based immunocontraceptive vaccines show activity in dogs of different breeds.

    PubMed

    Walker, John; Ghosh, Souravi; Pagnon, Joanne; Colantoni, Caterina; Newbold, Andrea; Zeng, Weiguang; Jackson, David C

    2007-10-10

    In this study we examine the immunogenicity of totally synthetic peptide-based immunocontraceptive vaccines in dogs. Seven individual epitope-based vaccines were assembled in which a different T helper (T(H)) cell epitope derived from the sequence of F protein of canine distemper virus was synthesized in tandem with a peptide representing luteinising hormone releasing hormone (LHRH). Each of the individual T(H)-LHRH peptide vaccines was inoculated subcutaneously into dogs. The results demonstrate that five of the seven peptide vaccines were able to elicit strong anti-LHRH antibody responses in beagle foxhounds accompanied by a concomitant suppression in the levels of the hormones testosterone and progesterone in the majority of the animals. A pool of these five peptides was then used to inoculate five different breeds of dogs. All animals responded with high levels of anti-LHRH antibody. An investigation of the proliferative responses of peripheral blood mononuclear cells (PBMC) obtained from inoculated dogs showed that the majority of breeds responded to each of the individual T helper cell epitope tested. The results provide a strategy for development of an immunocontraceptive vaccine for use in multiple breeds of dogs. PMID:17825958

  9. The cell-penetrating peptide domain from human heparin-binding epidermal growth factor-like growth factor (HB-EGF) has anti-inflammatory activity in vitro and in vivo

    SciTech Connect

    Lee, Jue-Yeon; Seo, Yoo-Na; Park, Hyun-Jung; Park, Yoon-Jeong; Chung, Chong-Pyoung

    2012-03-23

    Highlights: Black-Right-Pointing-Pointer HBP sequence identified from HB-EGF has cell penetration activity. Black-Right-Pointing-Pointer HBP inhibits the NF-{kappa}B dependent inflammatory responses. Black-Right-Pointing-Pointer HBP directly blocks phosphorylation and degradation of I{kappa}B{alpha}. Black-Right-Pointing-Pointer HBP inhibits nuclear translocation of NF-{kappa}B p65 subunit. -- Abstract: A heparin-binding peptide (HBP) sequence from human heparin-binding epidermal growth factor-like growth factor (HB-EGF) was identified and was shown to exhibit cell penetration activity. This cell penetration induced an anti-inflammatory reaction in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages. HBP penetrated the cell membrane during the 10 min treatment and reduced the LPS-induced production of nitric oxide (NO), inducible nitric oxide synthase (iNOS), and cytokines (TNF-{alpha} and IL-6) in a concentration-dependent manner. Additionally, HBP inhibited the LPS-induced upregulation of cytokines, including TNF-{alpha} and IL-6, and decreased the interstitial infiltration of polymorphonuclear leukocytes in a lung inflammation model. HBP inhibited NF-{kappa}B-dependent inflammatory responses by directly blocking the phosphorylation and degradation of I{kappa}B{alpha} and by subsequently inhibiting the nuclear translocation of the p65 subunit of NF-{kappa}B. Taken together, this novel HBP may be potentially useful candidate for anti-inflammatory treatments and can be combined with other drugs of interest to transport attached molecules into cells.

  10. Effects of GHRP-2 and Cysteamine Administration on Growth Performance, Somatotropic Axis Hormone and Muscle Protein Deposition in Yaks (Bos grunniens) with Growth Retardation

    PubMed Central

    Hu, Rui; Wang, Zhisheng; Peng, Quanhui; Zou, Huawei; Wang, Hongze; Yu, Xiaoqiang; Jing, Xiaoping; Wang, Yixin; Cao, Binghai; Bao, Shanke; Zhang, Wenhua; Zhao, Suonan; Ji, Hanzhong; Kong, Xiangying; Niu, Quanxi

    2016-01-01

    The objective of this study was to investigate the effects of growth hormone-releasing peptide-2 (GHRP-2) and cysteamine (CS) administration on growth performance in yaks with growth retardation and try to elucidate its regulatory mechanisms. Trial 1, thirty-six 1-year-old Qinghai high plateau yaks (body weight 38–83.2 kg) were randomly chosen for body weight and jugular blood samples collection. The relationship between body weight and serum GHRH (P < 0.05, R = 0.45), GH (P < 0.05, R = 0.47), IGF-1 (P < 0.05, R = 0.62) was significantly correlated in yaks colonies with lighter body weights. Trial 2, fifteen 1-year-old Qinghai high plateau yaks with growth retardation (average body weight 54.8 ± 8.24 kg) were randomly selected and assigned to negative control group (NG), GHRP-2 injection group (GG) and cysteamine feeding group (CG), with 5 yaks per group. Another five 1-year-old Qinghai high plateau yaks with normal growth performance (average body weight 75.3 ± 2.43 kg) were selected as positive control group (PG). The average daily gain (ADG) of the GG and CG were significantly higher than those in the PG and NG (P < 0.05). Both GHRP-2 and CS administration significantly enhanced the myofiber diameter and area of skeletal muscle (P<0.05). GHRP-2 significantly enhanced the serum GH and IGF-1 levels (P < 0.05), and up-regulated GHR, IGF-1 and IGF-1R mRNA expression in the liver and skeletal muscle (P < 0.05), enhanced the mRNA expression of PI3K, AKt and mTOR in the skeletal muscle (P<0.05). CS significantly reduced the serum SS levels and the hypothalamus SS mRNA expression (P < 0.05), and enhanced GHR and IGF-1 mRNA expression in the liver (P < 0.05), decreased the mRNA expression of muscle atrophy F-box (Atrogin-1) and muscle ring finger 1 (MuRF1) mRNA (P < 0.05). Conclusions: Growth retardation in yaks was primarily due to somatotropic axis hormones secretion deficiency. Both GHRP-2 and CS administration can accelerate growth performance and GH, IGF-1

  11. A tyrosine-phosphorylated carboxy-terminal peptide of the fibroblast growth factor receptor (Flg) is a binding site for the SH2 domain of phospholipase C-gamma 1.

    PubMed Central

    Mohammadi, M; Honegger, A M; Rotin, D; Fischer, R; Bellot, F; Li, W; Dionne, C A; Jaye, M; Rubinstein, M; Schlessinger, J

    1991-01-01

    Phospholipase C-gamma (PLC-gamma) is a substrate of the fibroblast growth factor receptor (FGFR; encoded by the flg gene) and other receptors with tyrosine kinase activity. It has been demonstrated that the src homology region 2 (SH2 domain) of PLC-gamma and of other signalling molecules such as GTPase-activating protein and phosphatidylinositol 3-kinase-associated p85 direct their binding toward tyrosine-autophosphorylated regions of the epidermal growth factor or platelet-derived growth factor receptor. In this report, we describe the identification of Tyr-766 as an autophosphorylation site of flg-encoded FGFR by direct sequencing of a tyrosine-phosphorylated tryptic peptide isolated from the cytoplasmic domain of FGFR expressed in Escherichia coli. The same phosphopeptide was found in wild-type FGFR phosphorylated either in vitro or in living cells. Like other growth factor receptors, tyrosine-phosphorylated wild-type FGFR or its cytoplasmic domain becomes associated with intact PLC-gamma or with a fusion protein containing the SH2 domain of PLC-gamma. To delineate the site of association, we have examined the capacity of a 28-amino-acid tryptic peptide containing phosphorylated Tyr-766 to bind to various constructs containing SH2 and other domains of PLC-gamma. It is demonstrated that the tyrosine-phosphorylated peptide binds specifically to the SH2 domain but not to the SH3 domain or other regions of PLC-gamma. Hence, Tyr-766 and its flanking sequences represent a major binding site in FGFR for PLC-gamma. Alignment of the amino acid sequences surrounding Tyr-766 with corresponding regions of other FGFRs revealed conserved tyrosine residues in all known members of the FGFR family. We propose that homologous tyrosine-phosphorylated regions in other FGFRs also function as binding sites for PLC-gamma and therefore are involved in coupling to phosphatidylinositol breakdown. Images PMID:1656221

  12. A new pro-migratory activity on human myogenic precursor cells for a synthetic peptide within the E domain of the mechano growth factor

    SciTech Connect

    Mills, Philippe; Lafreniere, Jean-Francois; Benabdallah, Basma Fattouma; El Fahime, El Mostafa; Tremblay, Jacques-P. . E-mail: Jacques-P.Tremblay@crchul.ulaval.ca

    2007-02-01

    Duchenne muscular dystrophy (DMD) is an inherited disease that leads to progressive muscle wasting. Myogenic precursor cell transplantation is an approach that can introduce the normal dystrophin gene in the muscle fibers of the patients. Unfortunately, these myogenic precursor cells do not migrate well in the muscle and thus many injections have to be done to enable a good graft success. Recent reports have shown that there is extensive splicing of the IGF-1 gene in muscles. The MGF isoform contains a C-terminal 24 amino acids peptide in the E domain (MGF-Ct24E) that has intrinsic properties. It can promote the proliferation while delaying the differentiation of C{sub 2}C{sub 12} cells. Here, we demonstrated that this synthetic peptide is a motogenic factor for human precursor myogenic cells in vitro and in vivo. Indeed, MGF-Ct24E peptide can modulate members of the fibrinolytic and metalloproteinase systems, which are implicated in the migration of myogenic cells. MGF-Ct24E peptide enhances the expression of u-PA, u-PAR and MMP-7 while reducing PAI-1 activity. Moreover, it has no effect on the gelatinases MMP-2 and -9. Those combined effects can favour cell migration. Finally, we present some results suggesting that the MGF-Ct24E peptide induces these cell responses through a mechanism that does not involve the IGF-1 receptor. Thus, this MGF-Ct24E peptide has a new pro-migratory activity on human myogenic precursor cells that may be helpful in the treatment of DMD. Those results reinforce the possibility that the IGF-1Ec isoform may produce an E domain peptide that can act as a cytokine.

  13. Synthesis of Electroneutralized Amphiphilic Copolymers with Peptide Dendrons for Intramuscular Gene Delivery.

    PubMed

    Pu, Linyu; Wang, Jiali; Li, Na; Chai, Qiuxia; Irache, Juan M; Wang, Gang; Tang, James Zhenggui; Gu, Zhongwei

    2016-06-01

    Intramuscular gene delivery materials are of great importance in plasmid-based gene therapy system, but there is limited information so far on how to design and synthesize them. A previous study showed that the peptide dendron-based triblock copolymer with its components arranged in a reversed biomembrane architecture could significantly increase intramuscular gene delivery and expression. Herein, we wonder whether copolymers with biomembrane-mimicking arrangement may have similar function on intramuscular gene delivery. Meanwhile, it is of great significance to uncover the influence of electric charge and molecular structure on the function of the copolymers. To address the issues, amphiphilic triblock copolymers arranged in hydrophilic-hydrophobic-hydrophilic structure were constructed despite the paradoxical characteristics and difficulties in synthesizing such hydrophilic but electroneutral molecules. The as-prepared two copolymers, dendronG2(l-lysine-OH)-poly propylene glycol2k(PPG2k)-dendronG2(l-lysine-OH) (rL2PL2) and dendronG3(l-lysine-OH)-PPG2k-dendronG3(l-lysine-OH) (rL3PL3), were in similar structure but had different hydrophilic components and surface charges, thus leading to different capabilities in gene delivery and expression in skeletal muscle. rL2PL2 was more efficient than Pluronic L64 and rL3PL3 when mediating luciferase, β-galactosidase, and fluorescent protein expressions. Furthermore, rL2PL2-mediated growth-hormone-releasing hormone expression could significantly induce mouse body weight increase in the first 21 days after injection. In addition, both rL2PL2 and rL3PL3 showed good in vivo biosafety in local and systemic administration. Altogether, rL2PL2-mediated gene expression in skeletal muscle exhibited applicable potential for gene therapy. The study revealed that the molecular structure and electric charge were critical factors governing the function of the copolymers for intramuscular gene delivery. It can be concluded that, combined

  14. Phytosulfokine peptide signalling.

    PubMed

    Sauter, Margret

    2015-08-01

    Phytosulfokine (PSK) belongs to the group of plant peptide growth factors. It is a disulfated pentapeptide encoded by precursor genes that are ubiquitously present in higher plants, suggestive of universal functions. Processing of the preproprotein involves sulfonylation by a tyrosylprotein sulfotransferase in the trans-golgi and proteolytic cleavage in the apoplast. The secreted peptide is perceived at the cell surface by a membrane-bound receptor kinase of the leucine-rich repeat family. The PSK receptor PSKR1 from Arabidopsis thaliana is an active kinase and has guanylate cyclase activity resulting in dual-signal outputs. Receptor activity is regulated by calmodulin. While PSK may be an autocrine growth factor, it also acts non-cell autonomously by promoting growth of cells that are receptor-deficient. In planta, PSK has multiple functions. It promotes cell growth, acts in the quiescent centre cells of the root apical meristem, contributes to funicular pollen tube guidance, and differentially alters immune responses depending on the pathogen. It has been suggested that PSK integrates growth and defence signals to balance the competing metabolic costs of these responses. This review summarizes our current understanding of PSK synthesis, signalling, and activity. PMID:25754406

  15. A rhesus monkey model to characterize the role of gastrin-releasing peptide (GRP) in lung development. Evidence for stimulation of airway growth.

    PubMed Central

    Li, K; Nagalla, S R; Spindel, E R

    1994-01-01

    Gastrin-releasing peptide (GRP) is developmentally expressed in human fetal lung and is a growth factor for normal and neoplastic lung but its role in normal lung development has yet to be clearly defined. In this study we have characterized the expression of GRP and its receptor in fetal rhesus monkey lung and determined the effects of bombesin on fetal lung development in vitro. By RNA blot analysis, GRP mRNA was first detectable in fetal monkey lung at 63 days gestation, reached highest levels at 80 days gestation, and then declined to near adult levels by 120 days gestation; a pattern closely paralleling GRP expression in human fetal lung. As in human lung, in situ hybridization localized GRP mRNA to neuroendocrine cells though during the canalicular phase of development (between 63-80 days gestation) GRP mRNA was present not only in classic pulmonary neuroendocrine cells, but also in cells of budding airways. Immunohistochemistry showed that bombesin-like immunoreactivity was present in neuroendocrine cells, but not in budding airways, suggesting that in budding airways either the GRP mRNA is not translated, is rapidly secreted, or a related, but different RNA is present. RNase protection analysis using a probe to the monkey GRP receptor demonstrated that the time course of receptor RNA expression closely paralleled the time course of GRP RNA expression. In situ hybridization showed that GRP receptors were primarily expressed in epithelial cells of the developing airways. Thus GRP would appear to be secreted from neuroendocrine cells to act on target cells in developing airways. This hypothesis was confirmed by organ culture of fetal monkey lung in the presence of bombesin and bombesin antagonists. Bombesin treatment at 1 and 10 nM significantly increased DNA synthesis in airway epithelial cells and significantly increased the number and size of airways in cultured fetal lung. In fact, culturing 60 d fetal lung for 5 d with 10 nM bombesin increased airway size

  16. Hydrophobic peptide auxotrophy in Salmonella typhimurium.

    PubMed Central

    Brãnes, L V; Somers, J M; Kay, W W

    1981-01-01

    The growth of a pleiotropic membrane mutant of Salmonella typhimurium with modified lipopolysaccharide composition was found to be strictly dependent on the peptone component of complex media. Nutritional Shiftdown into minimal media allowed growth for three to four generations. Of 20 commercial peptones, only enzymatic digests supported growth to varying degrees. Neither trace cations, amino acids, vitamins, carbohydrates, lipids, glutathione, polyamines, carbodimides, nor synthetic peptides stimulated growth; however, cells still metabolized carbohydrates, and amino acid transport systems were shown to be functional. A tryptic digest of casein was fractionated into four electrophoretically different peptide fractions of 1,000 to 1,200 molecular weight which supported growth to varying degrees. The best of these was further fractionated to two highly hydrophopic peptides. N-terminal modifications eliminated biological activity. Fluorescein-conjugated goat antibody to rabbit immunoglobulin G was used as a probe to detect antipeptide antibody-peptide complexes on membrane preparations. Cells grown on peptone distributed the peptide into both inner and outer membranes. The peptide could be removed with chaotropic agents, and cells had to be pregrown in peptone-containing media to bind the hydrophobic peptide. The gene (hyp) responsible for peptide auxotrophy was mapped at 44 to 45 units by conjugation. Images PMID:7024254

  17. [Progress on parasiticidal activity of anitimicrobial peptides].

    PubMed

    Liu, Ze-hua; Zhao, Jun-long

    2014-10-01

    Antimicrobial peptides are a kind of gene encoded, ribosome synthesized, small molecular polypeptides that have high efficiency, wide antibacterial spectrum, and low immunogenicity. Many studies have indicated that antimicrobial peptides can inhibit the growth of parasites or even kill them. This paper reviews the research progress on parasiticidal activity of the antimicrobial peptides in recent years, and presents the problems in the research. PMID:25726604

  18. Simultaneous quantification of intracellular and secreted active and inactive glucagon-like peptide-1 from cultured cells.

    PubMed

    Amao, Michiko; Kitahara, Yoshiro; Tokunaga, Ayaka; Shimbo, Kazutaka; Eto, Yuzuru; Yamada, Naoyuki

    2015-03-01

    Glucagon-like peptide-1 (GLP-1) is an incretin peptide that regulates islet hormone secretion. During recent years, incretin-based therapies have been widely used for patients with type 2 diabetes. GLP-1 peptides undergo N- and C-terminal processing for gain or loss of functions. We developed a method to quantify picomolar quantities of intact GLP-1 peptides using liquid chromatography-tandem mass spectrometry (LC-MS/MS). By employing this label-free selected reaction monitoring (SRM) method, we were able to analyze secreted GLP-1(1-37), GLP-1(7-37), and GLP-1(7-36 amid from human enteroendocrine NCI-H716 cells after stimulation with nateglinide, glucose, and sucralose. The absolute total concentrations of secreted GLP-1 peptides at baseline and after stimulation with nateglinide, glucose, and sucralose were 167.3, 498.9, 238.3, and 143.1 pM, respectively. Meanwhile, the ratios of GLP-1(1-37), GLP-1(7-37), and GLP-1(7-36 amide) to total GLP-1 peptides were similar (6 ± 3, 26 ± 3, and 78 ± 5%, respectively). The SRM assay can analyze the concentrations of individual GLP-1 peptides and, therefore, is a tool to investigate the physiological roles of GLP-1 peptides. Furthermore, the molecular species secreted from NCI-H716 cells were unknown. Therefore, we performed a secretopeptidome analysis of supernatants collected from cultured NCI-H716 cells. Together with GLP-1 peptides, we detected neuroendocrine convertase 1, which regulates peptide hormones released from intestinal endocrine L-cells. PMID:25461479

  19. Peptide arrays for screening cancer specific peptides.

    PubMed

    Ahmed, Sahar; Mathews, Anu Stella; Byeon, Nara; Lavasanifar, Afsaneh; Kaur, Kamaljit

    2010-09-15

    In this paper, we describe a novel method to screen peptides for specific recognition by cancer cells. Seventy peptides were synthesized on a cellulose membrane in an array format, and a direct method to study the peptide-whole cell interaction was developed. The relative binding affinity of the cells for different peptides with respect to a lead 12-mer p160 peptide, identified by phage display, was evaluated using the CyQUANT fluorescence of the bound cells. Screening allowed identification of at least five new peptides that displayed higher affinity (up to 3-fold) for MDA-MB-435 and MCF-7 human cancer cells compared to the p160 peptide. These peptides showed very little binding to the control (noncancerous) human umbilical vein endothelial cells (HUVECs). Three of these peptides were synthesized separately and labeled with fluorescein isothiocyanate (FITC) to study their uptake and interaction with the cancer and control cells using confocal laser scanning microscopy and flow cytometry. The results confirmed the high and specific affinity of an 11-mer peptide 11 (RGDPAYQGRFL) and a 10-mer peptide 18 (WXEAAYQRFL) for the cancer cells versus HUVECs. Peptide 11 binds different receptors on target cancer cells as its sequence contains multiple recognition motifs, whereas peptide 18 binds mainly to the putative p160 receptor. The peptide array-whole cell binding assay reported here is a complementary method to phage display for further screening and optimization of cancer targeting peptides for cancer therapy and diagnosis. PMID:20799711

  20. Neuroendocrine Regulation of Growth Hormone Secretion.

    PubMed

    Steyn, Frederik J; Tolle, Virginie; Chen, Chen; Epelbaum, Jacques

    2016-01-01

    This article reviews the main findings that emerged in the intervening years since the previous volume on hormonal control of growth in the section on the endocrine system of the Handbook of Physiology concerning the intra- and extrahypothalamic neuronal networks connecting growth hormone releasing hormone (GHRH) and somatostatin hypophysiotropic neurons and the integration between regulators of food intake/metabolism and GH release. Among these findings, the discovery of ghrelin still raises many unanswered questions. One important event was the application of deconvolution analysis to the pulsatile patterns of GH secretion in different mammalian species, including Man, according to gender, hormonal environment and ageing. Concerning this last phenomenon, a great body of evidence now supports the role of an attenuation of the GHRH/GH/Insulin-like growth factor-1 (IGF-1) axis in the control of mammalian aging. © 2016 American Physiological Society. Compr Physiol 6:687-735, 2016. PMID:27065166

  1. C-Peptide Test

    MedlinePlus

    ... C-peptide is a useful marker of insulin production. The following are some purposes of C-peptide ... it nearly impossible to directly evaluate endogenous insulin production. In these cases, C-peptide measurement is a ...

  2. Guanylyl cyclase/natriuretic peptide receptor-A signaling antagonizes the vascular endothelial growth factor-stimulated MAPKs and downstream effectors AP-1 and CREB in mouse mesangial cells

    PubMed Central

    Tripathi, Satyabha; Pandey, Kailash N.

    2012-01-01

    Along with its natriuretic, diuretic, and vasodilatory properties, atrial natriuretic peptide (ANP) and its guanylyl cyclase/natriuretic peptide receptor-A (GC-A/NPRA) exhibit an inhibitory effect on cell growth and proliferation. However, the signaling pathways mediating this inhibition are not well understood. The objective of this study was to determine the effect of ANP-NPRA system on mitogen-activated protein kinases (MAPKs) and the downstream proliferative transcription factors involving activating protein-1 (AP-1) and cAMP-response element binding protein (CREB) in agonist-stimulated mouse mesangial cells (MMCs). We found that ANP inhibited vascular endothelial growth factor (VEGF)-stimulated phosphorylation of MAPKs (Erk1, Erk2, JNK, and p38), to a greater extent in NPRA-transfected cells (50–60%) relative to vector-transfected cells (25–30%). The analyses of the phosphorylated transcription factors revealed that ANP inhibited VEGF-stimulated activation of CREB, and the AP-1 subunits (c-jun and c-fos). Gel shift assays demonstrated that ANP inhibited VEGF-stimulated AP-1 and CREB DNA-binding ability by 67 % and 62 %, respectively. The addition of the protein kinase G (PKG) inhibitor, KT-5823, restored the VEGF-stimulated activation of MAPKs, AP-1, and CREB, demonstrating the integral role of cGMP/PKG signaling in NPRA-mediated effects. Our results delineate the under lying mechanisms through which ANP-NPRA system exerts an inhibitory effect on MAPKs and down-stream effector molecules, AP-1 and CREB, critical for cell growth and proliferation. PMID:22610792

  3. Salt Reduction in a Model High-Salt Akawi Cheese: Effects on Bacterial Activity, pH, Moisture, Potential Bioactive Peptides, Amino Acids, and Growth of Human Colon Cells.

    PubMed

    Gandhi, Akanksha; Shah, Nagendra P

    2016-04-01

    This study evaluated the effects of sodium chloride reduction and its substitution with potassium chloride on Akawi cheese during storage for 30 d at 4 °C. Survival of probiotic bacteria (Lactobacillus acidophilus, Lactobacillus casei, and Bifidobacterium longum) and starter bacteria (Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus), angiotensin-converting enzyme-inhibitory and antioxidant activities, and concentrations of standard amino acids as affected by storage in different brine solutions (10% NaCl, 7.5% NaCl, 7.5% NaCl+KCl [1:1], 5% NaCl, and 5% NaCl+KCl [1:1]) were investigated. Furthermore, viability of human colon cells and human colon cancer cells as affected by the extract showing improved peptide profiles, highest release of amino acids and antioxidant activity (that is, from cheese brined in 7.5% NaCl+KCl) was evaluated. Significant increase was observed in survival of probiotic bacteria in cheeses with low salt after 30 d. Calcium content decreased slightly during storage in all cheeses brined in various solutions. Further, no significant changes were observed in ACE-inhibitory activity and antioxidant activity of cheeses during storage. Interestingly, concentrations of 4 essential amino acids (phenylalanine, tryptophan, valine, and leucine) increased significantly during storage in brine solutions containing 7.5% total salt. Low concentration of cheese extract (100 μg/mL) significantly improved the growth of normal human colon cells, and reduced the growth of human colon cancer cells. Overall, the study revealed that cheese extracts from reduced-NaCl brine improved the growth of human colon cells, and the release of essential amino acids, but did not affect the activities of potential bioactive peptides. PMID:26919457

  4. Peptide displacement of ( sup 3 H)5-hydroxytryptamine binding to bovine cortical membranes

    SciTech Connect

    Takeuchi, Y.; Root-Bernstein, R.S.; Shih, J.C. )

    1990-12-01

    Chemical studies have demonstrated that peptides such as the encephalitogenic (EAE) peptide of myelin basic protein (MBP) and luteinizing hormone-releasing hormone (LHRH) can bind serotonin (5-hydroxytryptamine, 5-HT) in vitro. The present research was undertaken to determine whether such binding interferes with 5-HT binding to its 5-HT1 receptors on bovine cerebral cortical membranes. EAE peptide and LHRH displaced ({sup 3}H)5-HT with IC50s of 4.0 x 10(-4) and 1.8 x 10(-3) M respectively. MBP itself also showed apparent displacing ability with an IC50 of 6.0 x 10(-5) M, though it also caused aggregation of cortical membranes that might have interfered with normal receptor binding. These results support previous suggestions that the tryptophan peptide region of MBP may act as a 5-HT receptor in the neural system. We also tested the effects of muramyl dipeptide (N-acetyl-muramyl-L-Ala-D-isoGln, MD), a bacterial cell-wall breakdown product that acts as a slow-wave sleep promoter, binds to LHRH and EAE peptide, and competes for 5-HT binding sites on macrophages. It showed no significant displacement of 5-HT binding to cortical membranes (IC50 greater than 10(-1) M), but its D-Ala analogue did (IC50 = 1.7 x 10(-3) M). Thus, it seems likely that the 5-HT-related effects of naturally occurring muramyl peptides are physiologically limited by receptor types.

  5. Growth

    NASA Astrophysics Data System (ADS)

    Waag, Andreas

    This chapter is devoted to the growth of ZnO. It starts with various techniques to grow bulk samples and presents in some detail the growth of epitaxial layers by metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), and pulsed laser deposition (PLD). The last section is devoted to the growth of nanorods. Some properties of the resulting samples are also presented. If a comparison between GaN and ZnO is made, very often the huge variety of different growth techniques available to fabricate ZnO is said to be an advantage of this material system. Indeed, growth techniques range from low cost wet chemical growth at almost room temperature to high quality MOCVD growth at temperatures above 1, 000∘C. In most cases, there is a very strong tendency of c-axis oriented growth, with a much higher growth rate in c-direction as compared to other crystal directions. This often leads to columnar structures, even at relatively low temperatures. However, it is, in general, not straight forward to fabricate smooth ZnO thin films with flat surfaces. Another advantage of a potential ZnO technology is said to be the possibility to grow thin films homoepitaxially on ZnO substrates. ZnO substrates are mostly fabricated by vapor phase transport (VPT) or hydrothermal growth. These techniques are enabling high volume manufacturing at reasonable cost, at least in principle. The availability of homoepitaxial substrates should be beneficial to the development of ZnO technology and devices and is in contrast to the situation of GaN. However, even though a number of companies are developing ZnO substrates, only recently good quality substrates have been demonstrated. However, these substrates are not yet widely available. Still, the situation concerning ZnO substrates seems to be far from low-cost, high-volume production. The fabrication of dense, single crystal thin films is, in general, surprisingly difficult, even when ZnO is grown on a ZnO substrate. However

  6. Tripartite neuroendocrine activation of the human growth hormone (GH) axis in women by continuous 24-hour GH-releasing peptide infusion: pulsatile, entropic, and nyctohemeral mechanisms.

    PubMed

    Shah, N; Evans, W S; Bowers, C Y; Veldhuis, J D

    1999-06-01

    Despite the discovery of potent GH-releasing peptides (GHRPs) more than 15 yr ago and the recent cloning of human, rat, and pig GHRP receptors in the hypothalamus and pituitary gland, the neuroregulatory mechanisms of action of GHRP agonists on the human hypothalamo-somatotroph unit are not well delineated. To gain such clinical insights, we evaluated the ultradian (pulsatile), entropic (pattern orderliness), and nyctohemeral GH secretory responses during continuous 24-h i.v. infusion of saline vs. the most potent clinically available hexapeptide, GHRP-2 (1 microg/kg x h) in estrogen-unreplaced (mean serum estradiol, 12 +/- 2.4 pg/mL) postmenopausal women (n = 7) in a paired, randomized design. Blood was sampled every 10 min for 24 h during infusions and was assayed by ultrasensitive GH chemiluminescence assay. Pulsatile GH secretion was quantitated by deconvolution analysis, orderliness of GH release patterns by the approximate entropy statistic, and 24-h GH rhythmicity by cosinor analysis. Statistical analysis revealed that GHRP-2 elicited a 7.7-fold increase in (24-h) mean serum (+/-SEM) GH concentrations, viz. from 0.32 +/- 0.042 (saline) to 2.4 +/- 0.34 microg/L (GHRP-2; P = 0.0006). This occurred via markedly stimulated pulsatile GH release, namely a 7.1-fold augmentation of GH secretory burst mass: 0.87 +/- 0.18 (control) vs. 6.3 +/- 1.3 microg/L (GHRP-2; P = 0.0038). Enhanced GH pulse mass reflected a commensurate 10-fold (P = 0.023) rise in GH secretory burst amplitude [maximal GH secretory rate (micrograms per L/min) attained within a secretory pulse] with no prolongation in event duration. GH burst frequency, interpulse interval, and calculated GH half-life were all invariant of GHRP-2 treatment. Concurrently, as detected in the ultrasensitive GH assay, GHRP-2 augmented deconvolution-estimated interpulse (basal) GH secretion by 4.5-fold (P = 0.025). The approximate entropy of 24-h serum GH concentration profiles rose significantly during GHRP-2 infusion

  7. Early events elicited by Bombesin and structurally related peptides in quiescent Swiss 3T3 cells. I. Activation of protein kinase C and inhibition of epidermal growth factor binding

    SciTech Connect

    Zachary, I.; Sinnett-Smith, J.W.; Rozengurt, E.

    1986-01-01

    Addition of bombesin to quiescent cultures of Swiss 3T3 cells caused a rapid increase in the phosphorylation of an M/sub r/ 80,000 cellular protein (designated 80k). The effect was both concentration and time dependent. The 80k phosphoproteins generated in response to bombesin and to phorbol 12,13-dibutyrate were identical as judged by one- and two-dimensional PAGE and by peptide mapping after partial proteolysis with Staphylococcus aureus V8 protease. In addition, prolonged pretreatment of 3T3 cells with phorbol 12,13-dibutyrate, which leads to the disappearance of protein kinase C activity, blocked the ability of bombesin to stimulate 80k. Bombesin also caused a rapid (1 min) inhibition of /sup 125/I-labeled epidermal growth factor (/sup 125/I-EGF) binding to Swiss 3T3 cells. The inhibition was both concentration and temperature dependent and resulted from a marked decrease in the affinity of the EGF receptor for its ligand. These results strongly suggest that these responses are mediated by specific high-affinity receptors that recognize the peptides of the bombesin family in Swiss 3T3 cells. While an increase in cytosolic Ca/sup 2 +/ concentration does not mediate the bombesin inhibition of /sup 125/I-EGF binding, the activation of protein kinase C in intact Swiss 3T3 cells by peptides of the bombesin family may lead to rapid inhibition of the binding of /sup 125/I-EGF to its cellular receptor.

  8. Laminin-111-derived peptides and cancer

    PubMed Central

    Kikkawa, Yamato; Hozumi, Kentaro; Katagiri, Fumihiko; Nomizu, Motoyoshi; Kleinman, Hynda K.; Koblinski, Jennifer E.

    2013-01-01

    Laminin-111 is a large trimeric basement membrane glycoprotein with many active sites. In particular, four peptides active in tumor malignancy studies have been identified in laminin-111 using a systematic peptide screening method followed by various assays. Two of the peptides (IKVAV and AG73) are found on the α1 chain, one (YIGSR) of the β1 chain and one (C16) on the γ1 chain. The four peptides have distinct activities and receptors. Since three of the peptides (IKVAV, AG73 and C16) strongly promote tumor growth, this may explain the potent effects laminin-111 has on malignant cells. The peptide, YIGSR, decreases tumor growth and experimental metastasis via a 32/67 kD receptor while IKVAV increases tumor growth, angiogenesis and protease activity via integrin receptors. AG73 increases tumor growth and metastases via syndecan receptors. C16 increases tumor growth and angiogenesis via integrins. Identification of such sites on laminin-111 will have use in defining strategies to develop therapeutics for cancer. PMID:23263633

  9. BAM 1 and RECEPTOR-LIKE PROTEIN KINASE 2 constitute a signaling pathway and modulate CLE peptide-triggered growth inhibition in Arabidopsis root.

    PubMed

    Shimizu, Noriko; Ishida, Takashi; Yamada, Masashi; Shigenobu, Shuji; Tabata, Ryo; Kinoshita, Atsuko; Yamaguchi, Katsushi; Hasebe, Mitsuyasu; Mitsumasu, Kanako; Sawa, Shinichiro

    2015-12-01

    Ligand receptor-based signaling is a means of cell-to-cell communication for coordinating developmental and physiological processes in multicellular organisms. In plants, cell-producing meristems utilize this signaling to regulate their activities and ensure for proper development. Shoot and root systems share common requirements for carrying out this process; however, its molecular basis is largely unclear. It has been suggested that synthetic CLV3/EMBRYO SURROUNDING REGION (CLE) peptide shrinks the root meristem through the actions of CLAVATA2 (CLV2) and the RECEPTOR-LIKE PROTEIN KINASE 2 (RPK2) pathway in Arabidopsis thaliana. Our genetic screening for mutations that resist CLE peptide signaling in roots determined that BAM1, which is a member of the leucine-rich repeat receptor-like kinase (LRR-RLK) family, is also involved in this pathway. BAM1 is preferentially expressed in the root tip, including the quiescent center and its surrounding stem cells. Our genetic analysis revealed that BAM1 functions together with RPK2. Using coimmunoprecipitation assay, we showed that BAM1 is capable of forming heteromeric complexes with RPK2. These findings suggest that the BAM1 and RPK2 receptors constitute a signaling pathway that modulates cell proliferation in the root meristem and that related molecules are employed in root and shoot meristems. PMID:26083273

  10. Free-radical scavenging properties of low molecular weight peptide(s) isolated from S1 cultivar of mulberry leaves and their impact on Bombyx mori (L.) (Bombycidae)

    PubMed Central

    2014-01-01

    The mulberry leaves have been considered as a sole food source for silkworm, Bombyx mori (L.). In present work an attempt was made to investigate the role of low molecular weight peptide(s) isolated from mulberry leaves on silkworm rearing. Also we have tried to find out the role of free-radical scavenging activities of isolated peptide(s) on silkworm growth. Larval growth rate was found effective under the influence of peptide(s). Consumption rate of larvae after peptide(s) treatment on mulberry leaves was significantly enhanced over control. High antioxidant activity was found in Low molecular weight peptide(s) which have an effect on silkworm. PMID:24612781

  11. A peptide fragment from the human COX3 protein disrupts association of Mycobacterium tuberculosis virulence proteins ESAT-6 and CFP10, inhibits mycobacterial growth and mounts protective immune response

    PubMed Central

    2014-01-01

    Background Tuberculosis (TB) is one of the most prevalent infectious diseases affecting millions worldwide. The currently available anti-TB drugs and vaccines have proved insufficient to contain this scourge, necessitating an urgent need for identification of novel drug targets and therapeutic strategies. The disruption of crucial protein-protein interactions, especially those that are responsible for virulence in Mycobacterium tuberculosis – for example the ESAT-6:CFP10 complex – are a worthy pursuit in this direction. Methods We therefore sought to improvise a method to attenuate M. tuberculosis while retaining the latter’s antigenic properties. We screened peptide libraries for potent ESAT-6 binders capable of dissociating CFP10 from ESAT-6. We assessed the disruption by a peptide named HCL2, of the ESAT-6:CFP10 complex and studied its effects on mycobacterial survival and virulence. Results We found that HCL2, derived from the human cytochrome c oxidase subunit 3 (COX3) protein, disrupts ESAT-6:CFP10 complex, binds ESAT-6 potently, disintegrates bacterial cell wall and inhibits extracellular as well as intracellular mycobacterial growth. In addition, an HCL2 expressing M. tuberculosis strain induces both Th1 and Th17 host protective responses. Conclusions Disruption of ESAT-6:CFP10 association could, therefore, be an alternate method for attenuating M. tuberculosis, and a possible route towards future vaccine generation. PMID:24985537

  12. Alcohol Alters Insulin-Like Growth Factor-1-Induced Transforming Growth Factor-ß1 Synthesis in the Medial Basal Hypothalamus of the Prepubertal Female Rat

    PubMed Central

    Hiney, Jill K.; Srivastava, Vinod K.; Volz, Claire E.; Dees, William L.

    2014-01-01

    Objective Insulin-like growth factor-1 (IGF-1) and transforming growth factor ß1 (TGFß1) are produced in hypothalamic astrocytes and facilitate luteinizing hormone-releasing hormone (LHRH) secretion. IGF-1 stimulates release by acting directly on the LHRH nerve terminals and both peptides act indirectly through specific plastic changes on glial/tanycyte processes that further support LHRH secretion. Because the relationship between these growth factors in the hypothalamus is not known, we assessed the ability of IGF-1 to induce TGFβ1 synthesis and release and the actions of alcohol (ALC) on this mechanism prior to the onset of puberty. Methods Hypothalamic astrocytes were exposed to medium only, medium plus IGF-1 (200 ng/ml) or medium plus IGF-1 with 50 mM ALC. After 18 hours, media were collected and assayed for TGFß1. For the in vivo experiment, prepubertal female rats were administered either ALC (3g/kg) or water via gastric gavage at 0730 h and at 1130h. At 0900 h, saline or IGF-1 was administered into the third ventricle. Rats were killed at 1500 hrs and the medial basal hypothalamus (MBH) was collected for assessment of TGFß1, IGF-1 receptor (IGF-1R) and Akt. Results IGF-1 induced TGFß1 release (p<0.01) from hypothalamic astrocytes in culture, an action blocked by ALC. In vivo, IGF-1 administration caused an increase in TGFβ1 protein compared to controls (p<0.05), an action blocked by ALC as well as a PI3K/Akt inhibitor. IGF-1 stimulation also increased both total (p<0.01) and phosphorylated (p<0.05) IGF-1R protein levels, and phosphorylated Akt levels (p<0.01), which were also blocked by ALC. Conclusions This study shows that ALC blocks IGF-1 actions to stimulate synthesis and release of hypothalamic TGFß1, total and phosphorylated IGF-1R and phosphorylated Akt levels further demonstrating the inhibitory actions of ALC on puberty-related events associated with hypothalamic LHRH release. PMID:25335926

  13. A synthetic mechano-growth factor E peptide promotes rat tenocyte migration by lessening cell stiffness and increasing F-actin formation via the FAK-ERK1/2 signaling pathway

    SciTech Connect

    Zhang, Bingyu; Luo, Qing; Mao, Xinjian; Xu, Baiyao; Yang, Li; Ju, Yang; Song, Guanbin

    2014-03-10

    Tendon injuries are common in sports and are frequent reasons for orthopedic consultations. The management of damaged tendons is one of the most challenging problems in orthopedics. Mechano-growth factor (MGF), a recently discovered growth repair factor, plays positive roles in tissue repair through the improvement of cell proliferation and migration and the protection of cells against injury-induced apoptosis. However, it remains unclear whether MGF has the potential to accelerate tendon repair. We used a scratch wound assay in this study to demonstrate that MGF-C25E (a synthetic mechano-growth factor E peptide) promotes the migration of rat tenocytes and that this promotion is accompanied by an elevation in the expression of the following signaling molecules: focal adhesion kinase (FAK) and extracellular signal regulated kinase1/2 (ERK1/2). Inhibitors of the FAK and ERK1/2 pathways inhibited the MGF-C25E-induced tenocyte migration, indicating that MGF-C25E promotes tenocyte migration through the FAK-ERK1/2 signaling pathway. The analysis of the mechanical properties showed that the Young's modulus of tenocytes was decreased through treatment of MGF-C25E, and an obvious formation of pseudopodia and F-actin was observed in MGF-C25E-treated tenocytes. The inhibition of the FAK or ERK1/2 signals restored the decrease in Young's modulus and inhibited the formation of pseudopodia and F-actin. Overall, our study demonstrated that MGF-C25E promotes rat tenocyte migration by lessening cell stiffness and increasing pseudopodia formation via the FAK-ERK1/2 signaling pathway. - Highlights: • Mechano-growth factor E peptide (MGF-C25E) promotes migration of rat tenocytes. • MGF-C25E activates the FAK-ERK1/2 pathway in rat tenocytes. • MGF-C25E induces the actin remodeling and the formation of pseudopodia, and decreases the stiffness in rat tenocytes. • MGF-C25E promotes tenocyte migration via altering stiffness and forming pseudopodia by the activation of the FAK-ERK1

  14. Immunoreactive opioid peptides in human breast cancer.

    PubMed Central

    Scopsi, L.; Balslev, E.; Brünner, N.; Poulsen, H. S.; Andersen, J.; Rank, F.; Larsson, L. I.

    1989-01-01

    Opioid peptides have a variety of actions on inter alia pituitary hormone secretion and the immune system. Release of endogenous opioids has been found to stimulate growth of experimental breast cancers and opiate receptor blockers have reduced the growth of chemically induced rat breast tumors. Opioid peptides may therefore play a role in human breast cancer. Invasive ductal carcinomas from 61 premenopausal women were immunocytochemically analyzed for the presence of opioid peptide immunoreactivity. Positive staining was unambiguously identified in 34 of the tumors (56%). In addition, a medullary carcinoma was positive. In a smaller series of tumors, opioid peptide immunoreactive cells were detected in both primary tumors and metastases. Positive tumor cells were usually few and scattered. Therefore, underestimates of their true frequency of occurrence are likely to have occurred, making accurate correlations with clinical behavior and estrogen receptor status difficult. No correlations with estrogen receptors were established for the unambiguously opioid peptide-positive tumors. Many of the positive tumors also stained with antibodies to gamma-endorphin and alpha-melanocyte-stimulating hormone, suggesting the presence of proopiomelanocortin-derived peptides in them. However, peptides derived from other opioid precursors also may be present in breast cancer. Images Figure 1 PMID:2464945

  15. SCUBE3 (Signal Peptide-CUB-EGF Domain-containing Protein 3) Modulates Fibroblast Growth Factor Signaling during Fast Muscle Development*

    PubMed Central

    Tu, Cheng-Fen; Tsao, Ku-Chi; Lee, Shyh-Jye; Yang, Ruey-Bing

    2014-01-01

    SCUBE3 (signal peptide CUB-EGF-like domain-containing protein 3) belongs to a newly identified secreted and cell membrane-associated SCUBE family, which is evolutionarily conserved in vertebrates. Scube3 is predominantly expressed in a variety of developing tissues in mice such as somites, neural tubes, and limb buds. However, its function during development remains unclear. In this study, we first showed that knockdown of SCUBE3 in C2C12 myoblasts inhibited FGF receptor 4 expression and FGF signaling, thus resulting in reduced myogenic differentiation. Furthermore, knockdown of zebrafish scube3 by antisense morpholino oligonucleotides specifically suppressed the expression of the myogenic marker myod1 within the lateral fast muscle precursors, whereas its expression in the adaxial slow muscle precursors was largely unaffected. Consistent with these findings, immunofluorescent staining of fast but not slow muscle myosin was markedly decreased in scube3 morphants. Further genetic studies identified fgf8 as a key regulator in scube3-mediated fast muscle differentiation in zebrafish. Biochemical and molecular analysis showed that SCUBE3 acts as a FGF co-receptor to augment FGF8 signaling. Scube3 may be a critical upstream regulator of fast fiber myogenesis by modulating fgf8 signaling during zebrafish embryogenesis. PMID:24849601

  16. Processable Cyclic Peptide Nanotubes with Tunable Interiors

    SciTech Connect

    Hourani, Rami; Zhang, Chen; van der Weegen, Rob; Ruiz, Luis; Li, Changyi; Keten, Sinan; Helms, Brett A.; Xu, Ting

    2011-09-06

    A facile route to generate cyclic peptide nanotubes with tunable interiors is presented. By incorporating 3-amino-2-methylbenzoic acid in the d,l-alternating primary sequence of a cyclic peptide, a functional group can be presented in the interior of the nanotubes without compromising the formation of high aspect ratio nanotubes. The new design of such a cyclic peptide also enables one to modulate the nanotube growth process to be compatible with the polymer processing window without compromising the formation of high aspect ratio nanotubes, thus opening a viable approach toward molecularly defined porous membranes.

  17. Antiserum raised against a synthetic phosphotyrosine-containing peptide selectively recognizes p185neu/erbB-2 and the epidermal growth factor receptor.

    PubMed Central

    Bangalore, L; Tanner, A J; Laudano, A P; Stern, D F

    1992-01-01

    Rabbits were immunized with a synthetic phosphopeptide corresponding to a major autophosphorylation site of p185neu/erbB2 to determine the feasibility of producing tyrosine-phosphopeptide-specific antibodies. A series of adsorption and affinity chromatography steps were used to select antibodies with the desired reactivity. Immunoblot experiments showed that the resulting serum is highly specific for tyrosine-phosphorylated forms of p185 and the related epidermal growth factor receptor. The serum recognized these two receptors selectively when compared to five other receptor tyrosine kinases and several phosphorylated substrates. The serum is compatible with tissue-based assays since it detected tyrosine phosphorylation of the epidermal growth factor receptor in immunofluorescence experiments on permeabilized cells. The generality of the procedures used means that similar anti-tyrosine phosphopeptide sera can be produced that recognize other tyrosine kinases and substrates. Such sera will have numerous applications in research and clinical settings. Images PMID:1280833

  18. Streptococcus pyogenes CovRS mediates growth in iron starvation and in the presence of the human cationic antimicrobial peptide LL-37.

    PubMed

    Froehlich, Barbara J; Bates, Christopher; Scott, June R

    2009-01-01

    We found that the global regulatory two-component signal transduction system CovRS mediates the ability of group A streptococcus (GAS) to grow under two stresses encountered during infection: iron starvation and the presence of LL-37. We also showed that CovRS regulates transcription of the multimetal transporter operon that is important for GAS growth in a low concentration of iron. PMID:18996992

  19. Brain natriutetic peptide test

    MedlinePlus

    ... medlineplus.gov/ency/article/007509.htm Brain natriuretic peptide test To use the sharing features on this page, please enable JavaScript. Brain natriuretic peptide (BNP) test is a blood test that measures ...

  20. Vasoactive intestinal peptide test

    MedlinePlus

    ... medlineplus.gov/ency/article/003508.htm Vasoactive intestinal peptide test To use the sharing features on this page, please enable JavaScript. Vasoactive intestinal peptide (VIP) is a test that measures the amount ...

  1. Effects of carbohydrate sugars and artificial sweeteners on appetite and the secretion of gastrointestinal satiety peptides.

    PubMed

    Steinert, Robert E; Frey, Florian; Töpfer, Antonia; Drewe, Jürgen; Beglinger, Christoph

    2011-05-01

    In vitro, both carbohydrate sugars and artificial sweeteners (AS) stimulate the secretion of glucagon-like peptide-1 (GLP-1). It has been suggested that the gut tastes sugars and AS through the same mechanisms as the tongue, with potential effects on gut hormone release. We investigated whether the human gut responds in the same way to AS and carbohydrate sugars, which are perceived by lingual taste as equisweet. We focused on the secretion of gastrointestinal (GI) satiety peptides in relation to appetite perception. We performed a placebo-controlled, double-blind, six-way, cross-over trial including twelve healthy subjects. On separate days, each subject received an intragastric infusion of glucose, fructose or an AS (aspartame, acesulfame K and sucralose) dissolved in 250 ml of water or water only (control). In a second part, four subjects received an intragastric infusion of the non-sweet, non-metabolisable sugar analogue 2-deoxy-d-glucose. Glucose stimulated GLP-1 (P = 0·002) and peptide tyrosine tyrosine (PYY; P = 0·046) secretion and reduced fasting plasma ghrelin (P = 0·046), whereas fructose was less effective. Both carbohydrate sugars increased satiety and fullness (albeit not significantly) compared with water. In contrast, equisweet loads of AS did not affect gastrointestinal peptide secretion with minimal effects on appetite. 2-Deoxy-d-glucose increased hunger ratings, however, with no effects on GLP-1, PYY or ghrelin. Our data demonstrate that the secretion of GLP-1, PYY and ghrelin depends on more than the detection of (1) sweetness or (2) the structural analogy to glucose. PMID:21255472

  2. [SYNTHETIC PEPTIDE VACCINES].

    PubMed

    Sergeyev, O V; Barinsky, I F

    2016-01-01

    An update on the development and trials of synthetic peptide vaccines is reviewed. The review considers the successful examples of specific protection as a result of immunization with synthetic peptides using various protocols. The importance of conformation for the immunogenicity of the peptide is pointed out. An alternative strategy of the protection of the organism against the infection using synthetic peptides is suggested. PMID:27145593

  3. The peptide ACTH(1-39), adrenal growth and steroidogenesis in the sheep fetus after disconnection of the hypothalamus and pituitary.

    PubMed

    Phillips, I D; Ross, J T; Owens, J A; Young, I R; McMillen, I C

    1996-03-15

    1. We have investigated the role of the fetal hypothalamo-pituitary axis in the control of adrenocortical growth and steroidogenesis in the sheep fetus during late gestation. Plasma concentrations of ACTH(1-39) increased between 120-125 and 136-142 days (P < 0.05), but did not change after surgical disconnection of the fetal hypothalamus and pituitary (HPD) at 106-120 days gestation. There was no effect of either gestational age or HPD on the circulating concentrations of the ACTH-containing precursors pro-opiomelanocortin (POMC) and pro-ACTH (the 22 kDa N-terminal portion of POMC). 2. In the fetal sheep adrenal, the relative abundance of the mRNAs of the steroidogenic enzymes CYPIIA1 and CYP21A1 increased between 130-135 and 136-140 days gestation (P < 0.05) and remained high after 141 days, whereas that of CYP17 mRNA increased after 141 days gestation (P < 0.05). The abundance of adrenal 3 beta-HSD mRNA did not change between 130 and 145 days. 3. Hypothalamo-pituitary disconnection significantly reduced the abundance of of CYPIIA1 mRNA, 3 beta-HSD mRNA and CYP17 mRNA by 3.4, 3.1 and 3.7 times, respectively, at 140-142 days gestation (P < 0.05). 4. In the intact group of fetal sheep, adrenal weight increased between 130-135 and 141-145 days (P < 0.05), but there was no change in the abundance of adrenal insulin-like growth factor II (IGF-II) mRNA across this gestational age range. Hypothalamo-pituitary disconnection significantly reduced fetal adrenal weight to 66% that of intact sheep (P < 0.01), but did not alter the abundance of IGF-II mRNA in the fetal adrenal at 140-142 days. 5. Our results suggest that the prepartum changes in adrenal growth and steroidogenesis are under the control of an intact hypothalamo-pituitary axis in late gestation and are dependent on an increase in circulating ACTH(1-39), rather than on ACTH precursors. We have found no evidence, however, for a direct-relationship between fetal adrenal growth or steroidogenesis and adrenal IGF-II m

  4. De-Novo Design of Antimicrobial Peptides for Plant Protection

    PubMed Central

    Zeitler, Benjamin; Herrera Diaz, Areli; Dangel, Alexandra; Thellmann, Martha; Meyer, Helge; Sattler, Michael; Lindermayr, Christian

    2013-01-01

    This work describes the de-novo design of peptides that inhibit a broad range of plant pathogens. Four structurally different groups of peptides were developed that differ in size and position of their charged and hydrophobic clusters and were assayed for their ability to inhibit bacterial growth and fungal spore germination. Several peptides are highly active at concentrations between 0,1 and 1 µg/ml against plant pathogenic bacteria, such as Pseudomonas syringae, Pectobacterium carotovorum, and Xanthomonas vesicatoria. Importantly, no hemolytic activity could be detected for these peptides at concentrations up to 200 µg/ml. Moreover, the peptides are also active after spraying on the plant surface demonstrating a possible way of application. In sum, our designed peptides represent new antimicrobial agents and with the increasing demand for antimicrobial compounds for production of “healthy” food, these peptides might serve as templates for novel antibacterial and antifungal agents. PMID:23951222

  5. PH dependent adhesive peptides

    DOEpatents

    Tomich, John; Iwamoto, Takeo; Shen, Xinchun; Sun, Xiuzhi Susan

    2010-06-29

    A novel peptide adhesive motif is described that requires no receptor or cross-links to achieve maximal adhesive strength. Several peptides with different degrees of adhesive strength have been designed and synthesized using solid phase chemistries. All peptides contain a common hydrophobic core sequence flanked by positively or negatively charged amino acids sequences.

  6. Antimicrobial Peptides in 2014

    PubMed Central

    Wang, Guangshun; Mishra, Biswajit; Lau, Kyle; Lushnikova, Tamara; Golla, Radha; Wang, Xiuqing

    2015-01-01

    This article highlights new members, novel mechanisms of action, new functions, and interesting applications of antimicrobial peptides reported in 2014. As of December 2014, over 100 new peptides were registered into the Antimicrobial Peptide Database, increasing the total number of entries to 2493. Unique antimicrobial peptides have been identified from marine bacteria, fungi, and plants. Environmental conditions clearly influence peptide activity or function. Human α-defensin HD-6 is only antimicrobial under reduced conditions. The pH-dependent oligomerization of human cathelicidin LL-37 is linked to double-stranded RNA delivery to endosomes, where the acidic pH triggers the dissociation of the peptide aggregate to release its cargo. Proline-rich peptides, previously known to bind to heat shock proteins, are shown to inhibit protein synthesis. A model antimicrobial peptide is demonstrated to have multiple hits on bacteria, including surface protein delocalization. While cell surface modification to decrease cationic peptide binding is a recognized resistance mechanism for pathogenic bacteria, it is also used as a survival strategy for commensal bacteria. The year 2014 also witnessed continued efforts in exploiting potential applications of antimicrobial peptides. We highlight 3D structure-based design of peptide antimicrobials and vaccines, surface coating, delivery systems, and microbial detection devices involving antimicrobial peptides. The 2014 results also support that combination therapy is preferred over monotherapy in treating biofilms. PMID:25806720

  7. Antimicrobial peptides in 2014.

    PubMed

    Wang, Guangshun; Mishra, Biswajit; Lau, Kyle; Lushnikova, Tamara; Golla, Radha; Wang, Xiuqing

    2015-01-01

    This article highlights new members, novel mechanisms of action, new functions, and interesting applications of antimicrobial peptides reported in 2014. As of December 2014, over 100 new peptides were registered into the Antimicrobial Peptide Database, increasing the total number of entries to 2493. Unique antimicrobial peptides have been identified from marine bacteria, fungi, and plants. Environmental conditions clearly influence peptide activity or function. Human α-defensin HD-6 is only antimicrobial under reduced conditions. The pH-dependent oligomerization of human cathelicidin LL-37 is linked to double-stranded RNA delivery to endosomes, where the acidic pH triggers the dissociation of the peptide aggregate to release its cargo. Proline-rich peptides, previously known to bind to heat shock proteins, are shown to inhibit protein synthesis. A model antimicrobial peptide is demonstrated to have multiple hits on bacteria, including surface protein delocalization. While cell surface modification to decrease cationic peptide binding is a recognized resistance mechanism for pathogenic bacteria, it is also used as a survival strategy for commensal bacteria. The year 2014 also witnessed continued efforts in exploiting potential applications of antimicrobial peptides. We highlight 3D structure-based design of peptide antimicrobials and vaccines, surface coating, delivery systems, and microbial detection devices involving antimicrobial peptides. The 2014 results also support that combination therapy is preferred over monotherapy in treating biofilms. PMID:25806720

  8. Mycocerein, a novel antifungal peptide antibiotic produced by Bacillus cereus.

    PubMed Central

    Wakayama, S; Ishikawa, F; Oishi, K

    1984-01-01

    A peptide was obtained from culture filtrates of a bacterium which was newly isolated and tentatively named Bacillus cereus SW. The peptide was composed of Asx, Ser, Glx, Leu, Tyr, Pro, and an unknown amino acid in a ratio of 2:1:1:1:1:1:1, but, unless hydrolyzed with HCI, it was ninhydrin reaction negative. The peptide effectively inhibited the growth of all fungi and yeasts so far examined, whereas it inhibited none of the bacteria tested. PMID:6441513

  9. Morphogenic Peptides in Regeneration of Load Bearing Tissues.

    PubMed

    Moeinzadeh, Seyedsina; Jabbari, Esmaiel

    2015-01-01

    Morphogenic proteins due to their short half-life require high doses of growth factors in regeneration of load bearing tissues which leads to undesirable side effects. These side effects include bone overgrowth, tumor formation and immune reaction. An alternative approach to reduce undesirable side effects of proteins in regenerative medicine is to use morphogenic peptides derived from the active domains of morphogenic proteins or soluble and insoluble components of the extracellular matrix of mineralized load bearing tissues to induce differentiation of progenitor cells, mineralization, maturation and bone formation. In that regard, many peptides with osteogenic activity have been discovered. These include peptides derived from bone morphogenic proteins (BMPs), those based on interaction with integrin and heparin-binding receptors, collagen derived peptides, peptides derived from other soluble ECM proteins such as bone sialoprotein and enamel matrix proteins, and those peptides derived from vasculoinductive and neuro-inductive proteins. Although these peptides show significant osteogenic activity in vitro and increase mineralization and bone formation in animal models, they are not widely used in clinical orthopedic applications as an alternative to morphogenic proteins. This is partly due to the limited availability of data on structure and function of morphogenic peptides in physiological medium, particularly in tissue engineered scaffolds. Due to their amphiphilic nature, peptides spontaneously self-assemble and aggregate into micellar structures in physiological medium. Aggregation alters the sequence of amino acids in morphogenic peptides that interact with cell surface receptors thus affecting osteogenic activity of the peptide. Aggregation and micelle formation can dramatically reduce the active concentration of morphogenic peptides with many-fold increase in peptide concentration in physiological medium. Other factors that affect bioactivity are the non

  10. C-Peptide and its intracellular signaling.

    PubMed

    Hills, Claire E; Brunskill, Nigel J

    2009-01-01

    Although long believed to be inert, C-peptide has now been shown to have definite biological effects both in vitro and in vivo in diabetic animals and in patients with type 1 diabetes. These effects point to a protective action of C-peptide against the development of diabetic microvascular complications. Underpinning these observations is undisputed evidence of C-peptide binding to a variety of cell types at physiologically relevant concentrations, and the downstream stimulation of multiple cell signaling pathways and gene transcription via the activation of numerous transcription factors. These pathways affect such fundamental cellular processes as re-absorptive and/or secretory phenotype, migration, growth, and survival. Whilst the receptor remains to be identified, experimental data points strongly to the existence of a specific G-protein-coupled receptor for C-peptide. Of the cell types studied so far, kidney tubular cells express the highest number of C-peptide binding sites. Accordingly, C-peptide exerts major effects on the function of these cells, and in the context of diabetic nephropathy appears to antagonise the pathophysiological effects of major disease mediators such as TGFbeta1 and TNFalpha. Therefore, based on its cellular activity profile C-peptide appears well positioned for development as a therapeutic tool to treat microvascular complications in type 1 diabetes. PMID:20039003

  11. Characterization of insulin-like growth factor I and insulin receptors on cultured bovine adrenal fasciculata cells. Role of these peptides on adrenal cell function

    SciTech Connect

    Penhoat, A.; Chatelain, P.G.; Jaillard, C.; Saez, J.M.

    1988-06-01

    We have characterized insulin-like growth factor I (IGF-I) and insulin receptors in cultured bovine adrenal cells by binding and cross-linking affinity experiments. At equilibrium the dissociation constant and the number of binding sites per cell for IGF-I were 1.4 +/- (SE) 0.3 x 10(-9) M and 19,200 +/- 2,100, respectively. Under reduction conditions, disuccinimidyl suberate cross-linked (/sup 125/I)iodo-IGF-I to one receptor complex with an Mr of 125,000. Adrenal cells also contain specific insulin receptors with an apparent dissociation constant (Kd) of 10(-9) M. Under reduction conditions (/sup 125/I)iodo-insulin binds to one band with an approximate Mr of 125,000. IGF-I and insulin at micromolar concentrations, but not at nanomolar concentrations, slightly stimulated DNA synthesis, but markedly potentiated the mitogenic action of fibroblast growth factor. Adrenal cells cultured in a serum-free medium containing transferrin, ascorbic acid, and insulin (5 micrograms/ml) maintained fairly constant angiotensin-II (A-II) receptor concentration per cell and increased cAMP release on response to ACTH and their steroidogenic response to both ACTH and A-II. When the cells were cultured in the same medium without insulin, the number of A-II receptors significantly decreased to 65% and the increased responsiveness was blunted. Treatment of such cells for 3 days with increasing concentrations of IGF-I (1-100 ng/ml) produced a 2- to 3-fold increase in A-II receptors and enhanced the cAMP response (3- to 4-fold) to ACTH and the steroidogenic response (4- to 6-fold) to ACTH and A-II. These effects were time and dose dependent (ED50 approximately equal to 10(-9) M). Insulin at micromolar concentrations produced an effect similar to that of IGF-I, but at nanomolar concentrations the effect was far less.

  12. Development of peptide-based patterns by laser transfer

    NASA Astrophysics Data System (ADS)

    Dinca, V.; Kasotakis, E.; Catherine, J.; Mourka, A.; Mitraki, A.; Popescu, A.; Dinescu, M.; Farsari, M.; Fotakis, C.

    2007-12-01

    Peptide-based arrays and patterns have provided a powerful tool in the study of protein recognition and function. A variety of applications have been identified, including the interactions between peptides-enzymes, peptides-proteins, peptides-DNA, peptides-small molecules and peptides-cells. One of the main and most critical unresolved issues is the generation of high-density arrays which maintain the biological function of the peptides. In this study, we employ nanosecond laser-induced forward transfer for the generation of high-density peptide arrays and patterns on modified glass surfaces. We show that peptide-based microarrays can be fabricated on solid surfaces and specifically recognized by appropriate fluorescent tags, with the transfer not affecting the ability of the peptides to form fibrils. These initial results are poised to the construction of larger peptide patterns as scaffolds for the incorporation and display of ligands critical for cell attachment and growth, or for the templating of inorganic materials.

  13. Identification of Candidate Angiogenic Inhibitors Processed by Matrix Metalloproteinase 2 (MMP-2) in Cell-Based Proteomic Screens: Disruption of Vascular Endothelial Growth Factor (VEGF)/Heparin Affin Regulatory Peptide (Pleiotrophin) and VEGF/Connective Tissue Growth Factor Angiogenic Inhibitory Complexes by MMP-2 Proteolysis▿ †

    PubMed Central

    Dean, Richard A.; Butler, Georgina S.; Hamma-Kourbali, Yamina; Delbé, Jean; Brigstock, David R.; Courty, José; Overall, Christopher M.

    2007-01-01

    Matrix metalloproteinases (MMPs) exert both pro- and antiangiogenic functions by the release of cytokines or proteolytically generated angiogenic inhibitors from extracellular matrix and basement membrane remodeling. In the Mmp2−/− mouse neovascularization is greatly reduced, but the mechanistic aspects of this remain unclear. Using isotope-coded affinity tag labeling of proteins analyzed by multidimensional liquid chromatography and tandem mass spectrometry we explored proteome differences between Mmp2−/− cells and those rescued by MMP-2 transfection. Proteome signatures that are hallmarks of proteolysis revealed cleavage of many known MMP-2 substrates in the cellular context. Proteomic evidence of MMP-2 processing of novel substrates was found. Insulin-like growth factor binding protein 6, follistatin-like 1, and cystatin C protein cleavage by MMP-2 was biochemically confirmed, and the cleavage sites in heparin affin regulatory peptide (HARP; pleiotrophin) and connective tissue growth factor (CTGF) were sequenced by matrix-assisted laser desorption ionization-time of flight mass spectrometry. MMP-2 processing of HARP and CTGF released vascular endothelial growth factor (VEGF) from angiogenic inhibitory complexes. The cleaved HARP N-terminal domain increased HARP-induced cell proliferation, whereas the HARP C-terminal domain was antagonistic and decreased cell proliferation and migration. Hence the unmasking of cytokines, such as VEGF, by metalloproteinase processing of their binding proteins is a new mechanism in the control of cytokine activation and angiogenesis. PMID:17908800

  14. Effects of Rice Bran, Flax Seed, and Sunflower Seed on Growth Performance, Carcass Characteristics, Fatty Acid Composition, Free Amino Acid and Peptide Contents, and Sensory Evaluations of Native Korean Cattle (Hanwoo)

    PubMed Central

    Choi, Chang Bon; Kwon, Hana; Kim, Sung Il; Yang, Un Mok; Lee, Ju Hwan; Park, Eun Kyu

    2016-01-01

    This study was conducted to evaluate the effect of dietary supplementation with rice bran, flax seed, or sunflower seed to finishing native Korean cattle (Hanwoo) on growth performances, carcass characteristics, fatty acid composition, free amino acid and peptide contents, and sensory evaluations of Longissimus muscle (LM). A total of 39 Hanwoo steers (average age of 22.2 mo and average body weight (BW) of 552.2 kg) were randomly divided into Control, rice bran (RB), flax seed (FS), or Sunflower seed (SS) groups. The steers were group fed for 273 d until they reached an average age of 31.2 mo. Final BW was 768.2, 785.8, 786.2, and 789.0 kg, and average daily gain was 0.79, 0.85, 0.82, and 0.84 kg for the Control, RS, FS, and SS groups, respectively (p>0.05). Fat thickness of the FS group (19.8 mm) was greater (p<0.05) than that of the other groups. Final yield grade converted into numerical values was 2.0 for the RB group, 1.7 for the Control and SS groups, and 1.4 for the FS group. Marbling degrees for the Control, SS, RB, and FS groups were 5.3, 5.1, 4.7, and 4.6, respectively. Percentages of palmitic acid (C16:0), stearic acid (C18:0), and arachidic acid (C20:0) in the LM were not different among the groups. Palmitoleic (C16:1) acid was higher (p<0.05) in the SS group. The concentration of oleic acid was highest (p<0.05) in the Control group (47.73%). The level of linolenic acid (C18:3) was 2.3 times higher (p<0.05) in the FS group compared to the other groups. Methionine concentration was (p<0.05) higher in FS (1.7 mg/100 g) and SS (1.2 mg/100 g) steers than in the Control or RB groups. Glutamic acid and α-aminoadipic acid (α-AAA) contents were (p<0.05) higher in the FS group compared to the other groups. LM from the FS group had numerically higher (p>0.05) scores for flavor, umami, and overall palatability in sensory evaluations. In conclusion, supplementation of flax seed to diets of finishing Hanwoo steers improved sensory evaluations which might have been

  15. Effects of Rice Bran, Flax Seed, and Sunflower Seed on Growth Performance, Carcass Characteristics, Fatty Acid Composition, Free Amino Acid and Peptide Contents, and Sensory Evaluations of Native Korean Cattle (Hanwoo).

    PubMed

    Choi, Chang Bon; Kwon, Hana; Kim, Sung Il; Yang, Un Mok; Lee, Ju Hwan; Park, Eun Kyu

    2016-02-01

    This study was conducted to evaluate the effect of dietary supplementation with rice bran, flax seed, or sunflower seed to finishing native Korean cattle (Hanwoo) on growth performances, carcass characteristics, fatty acid composition, free amino acid and peptide contents, and sensory evaluations of Longissimus muscle (LM). A total of 39 Hanwoo steers (average age of 22.2 mo and average body weight (BW) of 552.2 kg) were randomly divided into Control, rice bran (RB), flax seed (FS), or Sunflower seed (SS) groups. The steers were group fed for 273 d until they reached an average age of 31.2 mo. Final BW was 768.2, 785.8, 786.2, and 789.0 kg, and average daily gain was 0.79, 0.85, 0.82, and 0.84 kg for the Control, RS, FS, and SS groups, respectively (p>0.05). Fat thickness of the FS group (19.8 mm) was greater (p<0.05) than that of the other groups. Final yield grade converted into numerical values was 2.0 for the RB group, 1.7 for the Control and SS groups, and 1.4 for the FS group. Marbling degrees for the Control, SS, RB, and FS groups were 5.3, 5.1, 4.7, and 4.6, respectively. Percentages of palmitic acid (C16:0), stearic acid (C18:0), and arachidic acid (C20:0) in the LM were not different among the groups. Palmitoleic (C16:1) acid was higher (p<0.05) in the SS group. The concentration of oleic acid was highest (p<0.05) in the Control group (47.73%). The level of linolenic acid (C18:3) was 2.3 times higher (p<0.05) in the FS group compared to the other groups. Methionine concentration was (p<0.05) higher in FS (1.7 mg/100 g) and SS (1.2 mg/100 g) steers than in the Control or RB groups. Glutamic acid and α-aminoadipic acid (α-AAA) contents were (p<0.05) higher in the FS group compared to the other groups. LM from the FS group had numerically higher (p>0.05) scores for flavor, umami, and overall palatability in sensory evaluations. In conclusion, supplementation of flax seed to diets of finishing Hanwoo steers improved sensory evaluations which might have been

  16. Cell Penetrating Peptides and Cationic Antibacterial Peptides

    PubMed Central

    Rodriguez Plaza, Jonathan G.; Morales-Nava, Rosmarbel; Diener, Christian; Schreiber, Gabriele; Gonzalez, Zyanya D.; Lara Ortiz, Maria Teresa; Ortega Blake, Ivan; Pantoja, Omar; Volkmer, Rudolf; Klipp, Edda; Herrmann, Andreas; Del Rio, Gabriel

    2014-01-01

    Cell penetrating peptides (CPP) and cationic antibacterial peptides (CAP) have similar physicochemical properties and yet it is not understood how such similar peptides display different activities. To address this question, we used Iztli peptide 1 (IP-1) because it has both CPP and CAP activities. Combining experimental and computational modeling of the internalization of IP-1, we show it is not internalized by receptor-mediated endocytosis, yet it permeates into many different cell types, including fungi and human cells. We also show that IP-1 makes pores in the presence of high electrical potential at the membrane, such as those found in bacteria and mitochondria. These results provide the basis to understand the functional redundancy of CPPs and CAPs. PMID:24706763

  17. Synthetic LPETG-Containing Peptide Incorporation in the Staphylococcus aureus Cell-Wall in a Sortase A- and Growth Phase-Dependent Manner

    PubMed Central

    Hansenová Maňásková, Silvie; Nazmi, Kamran; van Belkum, Alex; Bikker, Floris J.; van Wamel, Willem J. B.; Veerman, Enno C. I.

    2014-01-01

    The majority of Staphylococcus aureus virulence- and colonization-associated surface proteins contain a pentapeptide recognition motif (LPXTG). This motif can be recognized and cleaved by sortase A (SrtA) which is a membrane-bound transpeptidase. After cleavage these proteins are covalently incorporated into the peptidoglycan. Therefore, SrtA plays a key role in S. aureus virulence. We aimed to generate a substrate mimicking this SrtA recognition motif for several purposes: to incorporate this substrate into the S. aureus cell-wall in a SrtA-dependent manner, to characterize this incorporation and to determine the effect of substrate incorporation on the incorporation of native SrtA-dependent cell-surface-associated proteins. We synthesized substrate containing the specific LPXTG motif, LPETG. As a negative control we used a scrambled version of this substrate, EGTLP and a S. aureus srtA knockout strain. Both substrates contained a fluorescence label for detection by FACScan and fluorescence microscope. A spreading assay and a competitive Luminex assay were used to determine the effect of substrate treatment on native LPXTG containing proteins deposition in the bacterial cell-wall. We demonstrate a SrtA-dependent covalent incorporation of the LPETG-containing substrate in wild type S. aureus strains and several other Gram-positive bacterial species. LPETG-containing substrate incorporation in S. aureus was growth phase-dependent and peaked at the stationary phase. This incorporation negatively correlated with srtA mRNA expression. Exogenous addition of the artificial substrate did not result in a decreased expression of native SrtA substrates (e.g. clumping factor A/B and protein A) nor induced a srtA knockout phenotype. PMID:24586638

  18. Increased nuclear stiffness via FAK-ERK1/2 signaling is necessary for synthetic mechano-growth factor E peptide-induced tenocyte migration

    PubMed Central

    Zhang, Bingyu; Luo, Qing; Chen, Zhen; Shi, Yisong; Ju, Yang; Yang, Li; Song, Guanbin

    2016-01-01

    We have previously reported that a synthetic mechano-growth factor (MGF) C-terminal E-domain with 25 amino acids (MGF-C25E) promotes rat tenocyte migration through the FAK-ERK1/2 signaling pathway. However, the role of the nucleus in MGF-C25E-promoted tenocyte migration and the molecular mechanisms involved remain unclear. In this study, we demonstrate that MGF-C25E increases the Young’s modulus of tenocytes through the FAK-ERK1/2 signaling pathway. This increase is not accompanied by an obvious change in the expression of Lamin A/C but is accompanied by significant chromatin condensation, indicating that MGF-C25E-induced chromatin condensation may contribute to the increased nuclear stiffness. Moreover, DNA methylation is observed in MGF-C25E-treated tenocytes. Inhibition of DNA methylation suppresses the elevation in chromatin condensation, in nuclear stiffness, and in tenocyte migration induced by MGF-C25E. The inhibition of the focal adhesion kinase (FAK) or extracellular signal regulated kinase 1/2 (ERK1/2) signals represses MGF-C25E-promoted DNA methylation. It also abolishes chromatin condensation, nuclear stiffness, and cell migration. Taken together, our results suggest that MGF-C25E promotes tenocyte migration by increasing nuclear stiffness via the FAK-ERK1/2 signaling pathway. This provides strong evidence for the role of nuclear mechanics in tenocyte migration and new insight into the molecular mechanisms of MGF-promoted tenocyte migration. PMID:26742689

  19. Plant peptide hormone signalling.

    PubMed

    Motomitsu, Ayane; Sawa, Shinichiro; Ishida, Takashi

    2015-01-01

    The ligand-receptor-based cell-to-cell communication system is one of the most important molecular bases for the establishment of complex multicellular organisms. Plants have evolved highly complex intercellular communication systems. Historical studies have identified several molecules, designated phytohormones, that function in these processes. Recent advances in molecular biological analyses have identified phytohormone receptors and signalling mediators, and have led to the discovery of numerous peptide-based signalling molecules. Subsequent analyses have revealed the involvement in and contribution of these peptides to multiple aspects of the plant life cycle, including development and environmental responses, similar to the functions of canonical phytohormones. On the basis of this knowledge, the view that these peptide hormones are pivotal regulators in plants is becoming increasingly accepted. Peptide hormones are transcribed from the genome and translated into peptides. However, these peptides generally undergo further post-translational modifications to enable them to exert their function. Peptide hormones are expressed in and secreted from specific cells or tissues. Apoplastic peptides are perceived by specialized receptors that are located at the surface of target cells. Peptide hormone-receptor complexes activate intracellular signalling through downstream molecules, including kinases and transcription factors, which then trigger cellular events. In this chapter we provide a comprehensive summary of the biological functions of peptide hormones, focusing on how they mature and the ways in which they modulate plant functions. PMID:26374891

  20. Peptides from milk proteins and their properties.

    PubMed

    Kilara, Arun; Panyam, Dinakar

    2003-01-01

    This review has attempted to study the literature pertaining to peptides derived from milk proteins. Hydrolysis of milk proteins to generate peptides has been practiced for a long time and it was recognized early on in this process that the taste of hydrolyzates might hinder use of these products in food formulations. Modification of protein is necessary to form a more acceptable or utilizable product, to form a product that is less susceptible to deteriorative reactions and to form a product that is of higher nutritionall quality. Modifications may be achieved by a number of chemical and enzymatic means. This review has considered only enzymatic modification of dairy proteins. Modified proteins contain peptides and some of these peptides have been purified and their functionalities have been compared with unmodified proteins. This paper has examined the literature pertaining to improvement in functionality of enzyme-modified proteins. Improvements in solubility, emulsification, foaming and gelation were examined. There is limited information available on the sequence of the peptides necessary to improve the functional characteristics of proteins. Knowing the sequences of desirable functional peptides can lead to genetic alteration of proteins to improve functionality. Addition of synthetic peptides to intact proteins may be another way in which the functionality of proteins can be augmented. Some of the peptides in milk proteins are capable of affecting biological functions of an organism. These effects can be antimicrobial and probiotic, i.e., prevent the growth and proliferation of undesirable and pathogenic organisms, or they may promote the growth of desirable bacteria in the digestive tract of humans and animals. Peptides derived from milk protein have been shown to exert digestive and metabolic effects as well. They may also influence the immune system. These biological effects may play an important role in the development of medical foods that treat or

  1. Antihypertensive peptides from curd

    PubMed Central

    Dabarera, Melani Chathurika; Athiththan, Lohini V.; Perera, Rasika P.

    2015-01-01

    Introduction: Curd (Dadhi) peptides reduce hypertension by inhibiting angiotensin converting enzyme (ACE) and serum cholesterol. Peptides vary with bacterial species and milk type used during fermentation. Aim: To isolate and assay the antihypertensive peptides, before and after digestion, in two commercially available curd brands in Sri Lanka. Materials and Methods: Whey (Dadhi Mastu) separated by high-speed centrifugation was isolated using reverse-phase-high- performance liquid chromatography (HPLC). Eluted fractions were analyzed for ACE inhibitory activity using modified Cushman and Cheung method. Curd samples were subjected to enzymatic digestion with pepsin, trypsin, and carboxypeptidase-A at their optimum pH and temperature. Peptides isolated using reverse-phase-HPLC was assayed for ACE inhibitory activity. Results: Whey peptides of both brands gave similar patterns (seven major and five minor peaks) in HPLC elution profile. Smaller peptides concentration was higher in brand 1 and penta-octapeptides in brand 2. Pentapeptide had the highest ACE inhibitory activity (brand 2–90% and brand 1–73%). After digestion, di and tri peptides with similar inhibitory patterns were obtained in both which were higher than before digestion. Thirteen fractions were obtained, where nine fractions showed more than 70% inhibition in both brands with 96% ACE inhibition for a di-peptide. Conclusion: Curd has ACE inhibitory peptides and activity increases after digestion. PMID:27011726

  2. Antimicrobial Peptides in Reptiles

    PubMed Central

    van Hoek, Monique L.

    2014-01-01

    Reptiles are among the oldest known amniotes and are highly diverse in their morphology and ecological niches. These animals have an evolutionarily ancient innate-immune system that is of great interest to scientists trying to identify new and useful antimicrobial peptides. Significant work in the last decade in the fields of biochemistry, proteomics and genomics has begun to reveal the complexity of reptilian antimicrobial peptides. Here, the current knowledge about antimicrobial peptides in reptiles is reviewed, with specific examples in each of the four orders: Testudines (turtles and tortosises), Sphenodontia (tuataras), Squamata (snakes and lizards), and Crocodilia (crocodilans). Examples are presented of the major classes of antimicrobial peptides expressed by reptiles including defensins, cathelicidins, liver-expressed peptides (hepcidin and LEAP-2), lysozyme, crotamine, and others. Some of these peptides have been identified and tested for their antibacterial or antiviral activity; others are only predicted as possible genes from genomic sequencing. Bioinformatic analysis of the reptile genomes is presented, revealing many predicted candidate antimicrobial peptides genes across this diverse class. The study of how these ancient creatures use antimicrobial peptides within their innate immune systems may reveal new understandings of our mammalian innate immune system and may also provide new and powerful antimicrobial peptides as scaffolds for potential therapeutic development. PMID:24918867

  3. Polycyclic peptide therapeutics.

    PubMed

    Baeriswyl, Vanessa; Heinis, Christian

    2013-03-01

    Owing to their excellent binding properties, high stability, and low off-target toxicity, polycyclic peptides are an attractive molecule format for the development of therapeutics. Currently, only a handful of polycyclic peptides are used in the clinic; examples include the antibiotic vancomycin, the anticancer drugs actinomycin D and romidepsin, and the analgesic agent ziconotide. All clinically used polycyclic peptide drugs are derived from natural sources, such as soil bacteria in the case of vancomycin, actinomycin D and romidepsin, or the venom of a fish-hunting coil snail in the case of ziconotide. Unfortunately, nature provides peptide macrocyclic ligands for only a small fraction of therapeutic targets. For the generation of ligands of targets of choice, researchers have inserted artificial binding sites into natural polycyclic peptide scaffolds, such as cystine knot proteins, using rational design or directed evolution approaches. More recently, large combinatorial libraries of genetically encoded bicyclic peptides have been generated de novo and screened by phage display. In this Minireview, the properties of existing polycyclic peptide drugs are discussed and related to their interesting molecular architectures. Furthermore, technologies that allow the development of unnatural polycyclic peptide ligands are discussed. Recent application of these technologies has generated promising results, suggesting that polycyclic peptide therapeutics could potentially be developed for a broad range of diseases. PMID:23355488

  4. Peptide folding simulations.

    PubMed

    Gnanakaran, S; Nymeyer, Hugh; Portman, John; Sanbonmatsu, Kevin Y; García, Angel E

    2003-04-01

    Developments in the design of small peptides that mimic proteins in complexity, recent advances in nanosecond time-resolved spectroscopy methods to study peptides and the development of modern, highly parallel simulation algorithms have come together to give us a detailed picture of peptide folding dynamics. Two newly implemented simulation techniques, parallel replica dynamics and replica exchange molecular dynamics, can now describe directly from simulations the kinetics and thermodynamics of peptide formation, respectively. Given these developments, the simulation community now has the tools to verify and validate simulation protocols and models (forcefields). PMID:12727509

  5. The development of decision limits for the GH-2000 detection methodology using additional insulin-like growth factor-I and amino-terminal pro-peptide of type III collagen assays.

    PubMed

    Holt, Richard I G; Böhning, Walailuck; Guha, Nishan; Bartlett, Christiaan; Cowan, David A; Giraud, Sylvain; Bassett, E Eryl; Sönksen, Peter H; Böhning, Dankmar

    2015-09-01

    The GH-2000 and GH-2004 projects have developed a method for detecting GH misuse based on measuring insulin-like growth factor-I (IGF-I) and the amino-terminal pro-peptide of type III collagen (P-III-NP). The objectives were to analyze more samples from elite athletes to improve the reliability of the decision limit estimates, to evaluate whether the existing decision limits needed revision, and to validate further non-radioisotopic assays for these markers. The study included 998 male and 931 female elite athletes. Blood samples were collected according to World Anti-Doping Agency (WADA) guidelines at various sporting events including the 2011 International Association of Athletics Federations (IAAF) World Athletics Championships in Daegu, South Korea. IGF-I was measured by the Immunotech A15729 IGF-I IRMA, the Immunodiagnostic Systems iSYS IGF-I assay and a recently developed mass spectrometry (LC-MS/MS) method. P-III-NP was measured by the Cisbio RIA-gnost P-III-P, Orion UniQ™ PIIINP RIA and Siemens ADVIA Centaur P-III-NP assays. The GH-2000 score decision limits were developed using existing statistical techniques. Decision limits were determined using a specificity of 99.99% and an allowance for uncertainty because of the finite sample size. The revised Immunotech IGF-I - Orion P-III-NP assay combination decision limit did not change significantly following the addition of the new samples. The new decision limits are applied to currently available non-radioisotopic assays to measure IGF-I and P-III-NP in elite athletes, which should allow wider flexibility to implement the GH-2000 marker test for GH misuse while providing some resilience against manufacturer withdrawal or change of assays. PMID:25645199

  6. Synthetic peptides that cause F-actin bundling and block actin depolymerization

    DOEpatents

    Sederoff, Heike; Huber, Steven C; Larabell, Carolyn A

    2011-10-18

    Synthetic peptides derived from sucrose synthase, and having homology to actin and actin-related proteins, sharing a common motif, useful for causing acting bundling and preventing actin depolymerization. Peptides exhibiting the common motif are described, as well as specific synthetic peptides which caused bundled actin and inhibit actin depolymerization. These peptides can be useful for treating a subject suffering from a disease characterized by cells having neoplastic growth, for anti-cancer therapeutics, delivered to subjects solely, or concomitantly or sequentially with other known cancer therapeutics. These peptides can also be used for stabilizing microfilaments in living cells and inhibiting growth of cells.

  7. CLE Peptide Signaling and Crosstalk with Phytohormones and Environmental Stimuli.

    PubMed

    Wang, Guodong; Zhang, Guohua; Wu, Mengyao

    2015-01-01

    The CLE (CLAVATA3/Endosperm surrounding region-related) peptide family is one of the best-studied secreted peptide families in plants. Accumulated data have revealed that CLE genes play vital roles on stem cell homeostasis in different types of meristems. Additionally, CLE genes have been found to perform various biological roles in plant growth and development, and in response to environmental stimuli. With recent advances on our understanding of CLE peptide function, it is showing that the existence of potential crosstalks of CLE peptides with phytohormones and external stimuli. Complex interactions exist in which CLE petides coordinate with hormones to regulate plant growth and development, and in response to external stimuli. In this article, we present recent advances in cell-cell communication that is mediated by CLE peptides combining with phytohormones and external stimuli, and suggest additional Arabidopsis CLE genes that are likely to be controlled by hormones and environmental cues. PMID:26779239

  8. Bovine hemoglobin: an attractive source of antibacterial peptides.

    PubMed

    Nedjar-Arroume, Naïma; Dubois-Delval, Véronique; Adje, Estelle Yaba; Traisnel, Jonathan; Krier, François; Mary, Patrice; Kouach, Mostafa; Briand, Gilbert; Guillochon, Didier

    2008-06-01

    A peptic hemoglobin hydrolysate was fractioned by a semi-preparative reversed-phase HPLC and some fractions have an antibacterial activity against four bacteria strains: Micrococcus luteus A270, Listeria innocua, Escherichia coli and Salmonella enteritidis. These fractions were analyzed by ESI/MS and ESI/MS/MS, in order to characterize the peptides in these fractions. Each fraction contains at least three peptides and some fractions contain five peptides. All these fractions were purified several times by HPLC to obtain pure peptides. Thirty antibacterial peptides were identified. From the isolated antibacterial peptides, 24 peptides were derived from the alpha chains of hemoglobin and 6 peptides were derived from the beta chains of hemoglobin. The lowest concentration of these peptides (minimum inhibitory concentration (MIC)) necessary to completely inhibit the growth of four bacteria strain was determined. The cell population of all of the tested bacteria species decreased by at least 97% after a 24-h incubation with any of the peptides at the minimum inhibitory concentration. PMID:18342399

  9. The anorexic hormone Peptide YY3–36 is rapidly metabolized to inactive Peptide YY3–34 in vivo

    PubMed Central

    Toräng, Signe; Veedfald, Simon; Rosenkilde, Mette Marie; Hartmann, Bolette; Holst, Jens Juul

    2015-01-01

    Peptide YY (PYY) is a 36 amino acid peptide hormone released from enteroendocrine cells. An N-terminally degraded metabolite, PYY3–36, has anorexigenic effects, which makes the PYY system a target for obesity treatment. However, little is known about the kinetics and degradation products of PYY. A related peptide, Neuropeptide Y (NPY), may be degraded from the C-terminus. We therefore investigated PYY degradation after in vitro incubations in porcine plasma and blood and in vivo by infusing PYY3–36 into multicatheterized pigs (n = 7) (2 pmol/kg/min). Plasma samples were analyzed by region-specific radioimmunoassays (RIA) and HPLC analysis. A metabolite, corresponding to PYY3–34 was formed after incubation in plasma and blood and during the infusion study. When taking the C-terminal degradation into account, the half-life (T½) of PYY in blood and plasma amounted to 3.4 ± 0.2 and 6.2 ± 0.2 h, respectively. After PYY3–36 infusion in pigs, the peptide was degraded with a T½ of 3.6 ± 0.5 min. Significant extraction (20.5 ± 8.0%) compatible with glomerular filtration was observed across the kidneys and significant C-terminal degradation (26.5 ± 4.8%) was observed across the liver. Net balances across the hind limb, splanchnic bed, and lungs were not significantly different from zero. PYY3–34 was unable to activate the Y2 receptor in a transfected cell line. In conclusion, PYY3–36 is extensively degraded to PYY3–34 in the pig, a degradation that renders the peptide inactive on the Y2 receptor. Currently used assays are unlikely to be able to detect this degradation and therefore measure falsely elevated levels of PYY3–36, leading to underestimation of its physiological effects. PMID:26197931

  10. An Arabidopsis peptide transporter is a member of a new class of membrane transport proteins.

    PubMed Central

    Steiner, H Y; Song, W; Zhang, L; Naider, F; Becker, J M; Stacey, G

    1994-01-01

    An Arabidopsis peptide transport gene was cloned from an Arabidopsis cDNA library by functionally complementing a yeast peptide transport mutant. The Arabidopsis plant peptide transporter (AtPTR2) allowed growth of yeast cells on dipeptides and tripeptides but not peptides four residues and higher. The plant peptide transporter also conferred sensitivity to a number of ethionine-containing, toxic peptides of chain length three or less and restored the ability to take up radiolabeled dileucine at levels similar to that of the wild type. Dileucine uptake was reduced by the addition of a variety of growth-promoting peptides. The sequence of a cDNA insert of 2.8 kb indicated an open reading frame encoding a 610-amino acid polypeptide (67.5 kD). Hydropathy analysis predicted a highly hydrophobic protein with a number of potential transmembrane segments. At the amino acid level, the Arabidopsis plant peptide transporter shows 24.6, 28.5, and 45.2% identity to the Arabidopsis nitrate-inducible nitrate transporter (CHL1), the rabbit small intestine oligopeptide transporter (PepT1), and the yeast peptide transporter (Ptr2p), respectively, but little identity to other proteins known to be involved in peptide transport. Root growth of Arabidopsis seedlings exposed to ethionine-containing toxic peptides was inhibited, and growth was restored by the addition of certain peptides shown to compete with dileucine uptake in yeast expressing the Arabidopsis transport gene. Consistent with the observed inhibition of root growth by toxic peptides, the peptide transporter is expressed in the roots of Arabidopsis seedlings. This study represents the characterization of a plant peptide transporter that is a member of a new class of related membrane transport proteins. PMID:7919993

  11. Insulin C-peptide test

    MedlinePlus

    C-peptide ... the test depends on the reason for the C-peptide measurement. Ask your health care provider if ... C-peptide is measured to tell the difference between insulin produced by the body and insulin injected ...

  12. Bacteriocin Inducer Peptides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Novel peptides produced by bacteriocin-producing bacteria stimulate the production of bacteriocins in vitro. The producer bacteria are cultured in the presence of a novel inducer bacteria and a peptide having a carboxy terminal sequence of VKGLT in order to achieve an increase in bacteriocin produc...

  13. Neuropeptides and Peptide Hormones in Anopheles gambiae

    NASA Astrophysics Data System (ADS)

    Riehle, Michael A.; Garczynski, Stephen F.; Crim, Joe W.; Hill, Catherine A.; Brown, Mark R.

    2002-10-01

    The African malaria mosquito, Anopheles gambiae, is specialized for rapid completion of development and reproduction. A vertebrate blood meal is required for egg production, and multiple feedings subsequently allow transmission of malaria parasites, Plasmodium spp. Regulatory peptides from 35 genes annotated from the A. gambiae genome likely coordinate these and other physiological processes. Plasmodium parasites may affect actions of newly identified insulin-like peptides, which coordinate growth and reproduction of its vector, A. gambiae, as in Drosophila melanogaster, Caenorhabditis elegans, and mammals. This genomic information provides a basis to expand understanding of hematophagy and pathogen transmission in this mosquito.

  14. Antimicrobial Peptides from Fish

    PubMed Central

    Masso-Silva, Jorge A.; Diamond, Gill

    2014-01-01

    Antimicrobial peptides (AMPs) are found widely distributed through Nature, and participate in the innate host defense of each species. Fish are a great source of these peptides, as they express all of the major classes of AMPs, including defensins, cathelicidins, hepcidins, histone-derived peptides, and a fish-specific class of the cecropin family, called piscidins. As with other species, the fish peptides exhibit broad-spectrum antimicrobial activity, killing both fish and human pathogens. They are also immunomodulatory, and their genes are highly responsive to microbes and innate immuno-stimulatory molecules. Recent research has demonstrated that some of the unique properties of fish peptides, including their ability to act even in very high salt concentrations, make them good potential targets for development as therapeutic antimicrobials. Further, the stimulation of their gene expression by exogenous factors could be useful in preventing pathogenic microbes in aquaculture. PMID:24594555

  15. BDNF pro-peptide regulates dendritic spines via caspase-3.

    PubMed

    Guo, J; Ji, Y; Ding, Y; Jiang, W; Sun, Y; Lu, B; Nagappan, G

    2016-01-01

    The precursor of brain-derived neurotrophic factor (BDNF) (proBDNF) is enzymatically cleaved, by either intracellular (furin/PC1) or extracellular proteases (tPA/plasmin/MMP), to generate mature BDNF (mBDNF) and its pro-peptide (BDNF pro-peptide). Little is known about the function of BDNF pro-peptide. We have developed an antibody that specifically detects cleaved BDNF pro-peptide, but not proBDNF or mBDNF. Neuronal depolarization elicited a marked increase in extracellular BDNF pro-peptide, suggesting activity-dependent regulation of its extracellular levels. Exposure of BDNF pro-peptide to mature hippocampal neurons in culture dramatically reduced dendritic spine density. This effect was mediated by caspase-3, as revealed by studies with pharmacological inhibitors and genetic knockdown. BDNF pro-peptide also increased the number of 'elongated' mitochondria and cytosolic cytochrome c, suggesting the involvement of mitochondrial-caspase-3 pathway. These results, along with BDNF pro-peptide effects recently reported on growth cones and long-term depression (LTD), suggest that BDNF pro-peptide is a negative regulator of neuronal structure and function. PMID:27310873

  16. Maturation processes and structures of small secreted peptides in plants

    PubMed Central

    Tabata, Ryo; Sawa, Shinichiro

    2014-01-01

    In the past decade, small secreted peptides have proven to be essential for various aspects of plant growth and development, including the maintenance of certain stem cell populations. Most small secreted peptides identified in plants to date are recognized by membrane-localized receptor kinases, the largest family of receptor proteins in the plant genome. This peptide-receptor interaction is essential for initiating intracellular signaling cascades. Small secreted peptides often undergo post-translational modifications and proteolytic processing to generate the mature peptides. Recent studies suggest that, in contrast to the situation in mammals, the proteolytic processing of plant peptides involves a number of complex steps. Furthermore, NMR-based structural analysis demonstrated that post-translational modifications induce the conformational changes needed for full activity. In this mini review, we summarize recent advances in our understanding of how small secreted peptides are modified and processed into biologically active peptides and describe the mature structures of small secreted peptides in plants. PMID:25071794

  17. Luteinizing hormone release and androgen production of avian hybrids in response to luteinizing hormone releasing hormone injection.

    PubMed

    Mathis, G F; Burke, W H; McDougald, L R

    1983-04-01

    The levels of luteinizing hormone (LH) and androgens were measured in sterile avian hybrids. Guinea fowl-chicken and peafowl-guinea fowl hybrids were bled before and after injection with LH- releasing hormone (LHRH). The preinjection LH levels for the guinea fowl-chicken hybrids were below or at the very lower limit of the assay sensitivity and the peafowl-guinea fowl hybrids averaged 1.3 ng/ml. Within 10 min after LHRH injection, LH had increased dramatically in both hybrids and then began to slowly decline. Androgen levels in the guinea fowl-chicken hybrids increased from 16.2 pg/ml to 95.2 pg/ml and continued to increase, reaching 287 pg/ml at the last bleeding 60 min after injection. PMID:6346309

  18. Self-assembly of peptide-amphiphile nanofibers under physiological conditions

    DOEpatents

    Stupp, Samuel I.; Hartgerink, Jeffrey D.; Beniash, Elia

    2011-11-22

    The present invention provides a method of promoting neuron growth and development by contacting cells with a peptide amphiphile molecule in an aqueous solution in the presence of a metal ion. According to the method, the peptide amphiphile forms a cylindrical micellar nanofiber composed of beta-sheets, which promote neuron growth and development.

  19. Synthesis of the Growth Hormone Secretion Mechanism Using Nonlinear Analysis and CAD Tools.

    PubMed

    Shell, J R

    2005-01-01

    The goal of this paper is to present a hardware realization of the feed-forward and feedback hypothalamic-pituitary growth hormone (GH) secretion mechanism based on a bio-mathematical nonlinear delay differential equation model developed by Farhy et al. (2003) and Veldhuis et al. (2001). Behavioral modeling is implemented through Verilog hardware descriptive language (HDL) to simulate the antagonistic and stimulatory interaction of growth hormone, growth hormone releasing hormone (GHRH) and somatotropin release inhibiting factor (SRIF). The model is synthesized using computer aided design (CAD) tools and is promulgated through a combinational complex programmable logic device (CPLD)/field programmable grid array (FPGA) Xilinx XSA-50 microchip. The microchip sequentially displays the decimal equivalents of the time changing hormonal concentration levels of the biomathematical model. PMID:17281277

  20. New peptides players in metabolic disorders.

    PubMed

    Mierzwicka, Agata; Bolanowski, Marek

    2016-01-01

    Among new peptides responsible for the pathogenesis of metabolic disorders and carbohydrate metabolism, adipokines are of great importance. Adipokines are substances of hormonal character, secreted by adipose tissue. Apart from the well-known adipokines, adropin and preptin are relatively newly discovered, hence their function is not fully understood. They are peptides not secreted by adipose tissue but their role in the metabolic regulations seems to be significant. Preptin is a 34-amino acid peptide, a derivative of proinsulin growth factor II (pro-IGF-II), secreted by pancreatic β cells, considered to be a physiological enhancer of insulin secretion. Additionally, preptin has a stimulating effect on osteoblasts, inducing their proliferation, differentiation and survival. Adropin is a 76-amino acid peptide, encoded by the energy homeostasis associated gene (Enho), mainly in liver and brain, and its expression is dependent on a diet. Adropin is believed to play an important role in metabolic homeostasis, fatty acids metabolism control, insulin resistance prevention, dyslipidemia, and impaired glucose tolerance. The results of studies conducted so far show that the diseases resulting from metabolic syndrome, such as obesity, type 2 diabetes mellitus, polycystic ovary syndrome, non-alcoholic fatty liver disease, or cardiovascular disease are accompanied by significant changes in the concentration of these peptides. It is also important to note that preptin has an anabolic effect on bone tissue, which might be preventive in osteoporosis. PMID:27594563

  1. Permeability and contractile responses of collecting lymphatic vessels elicited by atrial and brain natriuretic peptides.

    PubMed

    Scallan, Joshua P; Davis, Michael J; Huxley, Virginia H

    2013-10-15

    Atrial and brain natriuretic peptides (ANP and BNP, respectively) are cardiac hormones released into the bloodstream in response to hypervolaemia or fluid shifts to the central circulation. The actions of both peptides include natriuresis and diuresis, a decrease in systemic blood pressure, and inhibition of the renin-angiotensin-aldosterone system. Further, ANP and BNP elicit increases in blood microvessel permeability sufficient to cause protein and fluid extravasation into the interstitium to reduce the vascular volume. Given the importance of the lymphatic vasculature in maintaining fluid balance, we tested the hypothesis that ANP or BNP (100 nM) would likewise elevate lymphatic permeability (Ps) to serum albumin. Using a microfluorometric technique adapted to in vivo lymphatic vessels, we determined that rat mesenteric collecting lymphatic Ps to rat serum albumin increased by 2.0 ± 0.4-fold (P = 0.01, n = 7) and 2.7 ± 0.8-fold (P = 0.07, n = 7) with ANP and BNP, respectively. In addition to measuring Ps responses, we observed changes in spontaneous contraction amplitude and frequency from the albumin flux tracings in vivo. Notably, ANP abolished spontaneous contraction amplitude (P = 0.005) and frequency (P = 0.006), while BNP augmented both parameters by ∼2-fold (P < 0.01 each). These effects of ANP and BNP on contractile function were examined further by using an in vitro assay. In aggregate, these data support the theory that an increase in collecting lymphatic permeability opposes the absorptive function of the lymphatic capillaries, and aids in the retention of protein and fluid in the interstitial space to counteract volume expansion. PMID:23897233

  2. Tumor-Penetrating Peptides

    PubMed Central

    Teesalu, Tambet; Sugahara, Kazuki N.; Ruoslahti, Erkki

    2013-01-01

    Tumor-homing peptides can be used to deliver drugs into tumors. Phage library screening in live mice has recently identified homing peptides that specifically recognize the endothelium of tumor vessels, extravasate, and penetrate deep into the extravascular tumor tissue. The prototypic peptide of this class, iRGD (CRGDKGPDC), contains the integrin-binding RGD motif. RGD mediates tumor-homing through binding to αv integrins, which are selectively expressed on various cells in tumors, including tumor endothelial cells. The tumor-penetrating properties of iRGD are mediated by a second sequence motif, R/KXXR/K. This C-end Rule (or CendR) motif is active only when the second basic residue is exposed at the C-terminus of the peptide. Proteolytic processing of iRGD in tumors activates the cryptic CendR motif, which then binds to neuropilin-1 activating an endocytic bulk transport pathway through tumor tissue. Phage screening has also yielded tumor-penetrating peptides that function like iRGD in activating the CendR pathway, but bind to a different primary receptor. Moreover, novel tumor-homing peptides can be constructed from tumor-homing motifs, CendR elements and protease cleavage sites. Pathologies other than tumors can be targeted with tissue-penetrating peptides, and the primary receptor can also be a vascular “zip code” of a normal tissue. The CendR technology provides a solution to a major problem in tumor therapy, poor penetration of drugs into tumors. The tumor-penetrating peptides are capable of taking a payload deep into tumor tissue in mice, and they also penetrate into human tumors ex vivo. Targeting with these peptides specifically increases the accumulation in tumors of a variety of drugs and contrast agents, such as doxorubicin, antibodies, and nanoparticle-based compounds. Remarkably the drug to be targeted does not have to be coupled to the peptide; the bulk transport system activated by the peptide sweeps along any compound that is present in the

  3. Antimitotic peptides and depsipeptides.

    PubMed

    Hamel, Ernest; Covell, David G

    2002-01-01

    Tubulin is the target for an ever increasing number of unusual peptides and depsipeptides that were originally isolated from a wide variety of organisms. Since tubulin is the major component of cellular microtubules, which maintain cell shape in interphase and form the mitotic spindle, most of these compounds are highly toxic to mammalian cells. These peptides and depsipeptides disrupt cellular microtubules and prevent formation of a functional spindle, resulting in the accumulation of cultured cells in the G2/M phase of the cell cycle through specific inhibition of mitosis. At the biochemical level, the compounds all inhibit the assembly of tubulin into polymer and, in the cases where it has been studied, strongly suppress microtubule dynamics at low concentrations. In most cases the peptides and depsipeptides inhibit the binding of vinblastine and vincristine to tubulin in a noncompetitive manner, inhibit tubulin-dependent GTP hydrolysis, and interfere with nucleotide turnover at the exchangeable GTP site on beta-tubulin. Most of the peptides and depsipeptides induce tubulin to form oligomers of aberrant morphology, including tubulin rings that vary in diameter depending on the (depsi) peptide under study. The purpose of this review is to give an overview of the cellular, biochemical, in vivo, and SAR aspects of this group of compounds. We also summarize initial efforts by computer modeling to decipher a pharmacophore among the diverse structures of these peptides and depsipeptides. PMID:12678750

  4. Peptide portions may hold key to amplifying bone against porosis

    SciTech Connect

    Cotton, P.

    1990-02-02

    Pieces of peptides that are encoded in the calcitonin gene may explain enigmas in treatment of bone disease. Amplification of bone formation by two peptides with similar amino acid sequences was reported at the Third International Conference on the Fundamentals of Bone Growth at the University of California, Los Angeles (UCLA), schools of medicine and dentistry. One treatment enigma is that calcitonin regulates normal bone resorption but does not work as well when administered for the treatment of osteoporosis. While hormone therapy does work, it has wide-ranging effects like the potential for an increased risk of breast cancer. Bone-growth promotion by a better-known peptide, calcitonin gene-related peptide (CGRP), was described. The CGRP is usually processed in the nervous system and has a wide range of activity.

  5. Novel antimicrobial peptides that inhibit gram positive bacterial exotoxin synthesis.

    PubMed

    Merriman, Joseph A; Nemeth, Kimberly A; Schlievert, Patrick M

    2014-01-01

    Gram-positive bacteria, such as Staphylococcus aureus, cause serious human illnesses through combinations of surface virulence factors and secretion of exotoxins. Our prior studies using the protein synthesis inhibitor clindamycin and signal transduction inhibitors glycerol monolaurate and α-globin and β-globin chains of hemoglobin indicate that their abilities to inhibit exotoxin production by S. aureus are separable from abilities to inhibit growth of the organism. Additionally, our previous studies suggest that inhibition of exotoxin production, in absence of ability to kill S. aureus and normal flora lactobacilli, will prevent colonization by pathogenic S. aureus, while not interfering with lactobacilli colonization. These disparate activities may be important in development of novel anti-infective agents that do not alter normal flora. We initiated studies to explore the exotoxin-synthesis-inhibition activity of hemoglobin peptides further to develop potential agents to prevent S. aureus infections. We tested synthesized α-globin chain peptides, synthetic variants of α-globin chain peptides, and two human defensins for ability to inhibit exotoxin production without significantly inhibiting S. aureus growth. All of these peptides were weakly or not inhibitory to bacterial growth. However, the peptides were inhibitory to exotoxin production with increasing activity dependent on increasing numbers of positively-charged amino acids. Additionally, the peptides could be immobilized on agarose beads or have amino acid sequences scrambled and still retain exotoxin-synthesis-inhibition. The peptides are not toxic to human vaginal epithelial cells and do not inhibit growth of normal flora L. crispatus. These peptides may interfere with plasma membrane signal transduction in S. aureus due to their positive charges. PMID:24748386

  6. Peptide assemblies: from cell scaffolds to immune adjuvants

    NASA Astrophysics Data System (ADS)

    Collier, Joel

    2011-03-01

    This talk will discuss two interrelated aspects of peptide self-assemblies in biological applications: their use as matrices for regenerative medicine, and their use as chemically defined adjuvants for directing immune responses against engineered antigens. In the first half of the presentation, the design of peptide self-assemblies as analogues for the extracellular matrix will be described, with a focus on self-assemblies displaying multiple different cell-binding peptides. We conducted multi-factorial investigations of peptide co-assemblies containing several different ligand-bearing peptides using statistical ``design of experiments'' (DoE). Using the DoE techniques of factorial experimentation and response surface modeling, we systematically explored how precise combinations of ligand-bearing peptides modulated endothelial cell growth, in the process finding interactions between ligands not previously appreciated. By investigating immune responses against the materials intended for tissue engineering applications, we discovered that the basic self-assembling peptides were minimally immunogenic or non-immunogenic, even when delivered in strong adjuvants. -But when they were appended to an appropriately restricted epitope peptide, these materials raised strong and persistent antibody responses. These responses were dependent on covalent conjugation between the epitope and self-assembling domains of the peptides, were mediated by T cells, and could be directed towards both peptide epitopes and conjugated protein antigens. In addition to their demonstrated utility as scaffolds for regenerative medicine, peptide self-assemblies may also be useful as chemically defined adjuvants for vaccines and immunotherapies. This work was funded by NIH/NIDCR (1 R21 DE017703-03), NIH/NIBIB (1 R01 EB009701-01), and NSF (CHE-0802286).

  7. Uncovering the design rules for peptide synthesis of metal nanoparticles.

    PubMed

    Tan, Yen Nee; Lee, Jim Yang; Wang, Daniel I C

    2010-04-28

    Peptides are multifunctional reagents (reducing and capping agents) that can be used for the synthesis of biocompatible metal nanoparticles under relatively mild conditions. However, the progress in peptide synthesis of metal nanoparticles has been slow due to the lack of peptide design rules. It is difficult to establish sequence-reactivity relationships from peptides isolated from biological sources (e.g., biomineralizing organisms) or selected by combinatorial display libraries because of their widely varying compositions and structures. The abundance of random and inactive amino acid sequences in the peptides also increases the difficulty in knowledge extraction. In this study, a "bottom-up" approach was used to formulate a set of rudimentary rules for the size- and shape-controlled peptide synthesis of gold nanoparticles from the properties of the 20 natural alpha-amino acids for AuCl(4)(-) reduction and binding to Au(0). It was discovered that the reduction capability of a peptide depends on the presence of certain reducing amino acid residues, whose activity may be regulated by neighboring residues with different Au(0) binding strengths. Another finding is the effect of peptide net charge on the nucleation and growth of the Au nanoparticles. On the basis of these understandings, several multifunctional peptides were designed to synthesize gold nanoparticles in different morphologies (nanospheres and nanoplates) and with sizes tunable by the strategic placement of selected amino acid residues in the peptide sequence. The methodology presented here and the findings are useful for establishing the scientific basis for the rational design of peptides for the synthesis of metal nanostructures. PMID:20355728

  8. Linear antimicrobial peptides from Ectatomma quadridens ant venom.

    PubMed

    Pluzhnikov, Kirill A; Kozlov, Sergey A; Vassilevski, Alexander A; Vorontsova, Olga V; Feofanov, Alexei V; Grishin, Eugene V

    2014-12-01

    Venoms from three poneromorph ant species (Paraponera clavata, Ectatomma quadridens and Ectatomma tuberculatum) were investigated for the growth inhibition of Gram-positive and Gram-negative bacteria. It was shown that the venom of E. quadridens and its peptide fraction in particular possess marked antibacterial action. Three linear antimicrobial peptides sharing low similarity to the well-known ponericin peptides were isolated from this ant venom by means of size-exclusion and reversed-phase chromatography. The peptides showed antimicrobial activity at low micromolar concentrations. Their primary structure was established by direct Edman sequencing in combination with mass spectrometry. The most active peptide designated ponericin-Q42 was chemically synthesized. Its secondary structure was investigated in aqueous and membrane-mimicking environment, and the peptide was shown to be partially helical already in water, which is unusual for short linear peptides. Analysis of its activity on different bacterial strains, human erythrocytes and chronic myelogenous leukemia K562 cells revealed that the peptide shows broad spectrum cytolytic activity at micromolar and submicromolar concentrations. Ponericin-Q42 also possesses weak toxic activity on flesh fly larvae with LD50 of ∼105 μg/g. PMID:25220871

  9. Cancer Treatment Using Peptides: Current Therapies and Future Prospects

    PubMed Central

    Thundimadathil, Jyothi

    2012-01-01

    This paper discusses the role of peptides in cancer therapy with special emphasis on peptide drugs which are already approved and those in clinical trials. The potential of peptides in cancer treatment is evident from a variety of different strategies that are available to address the progression of tumor growth and propagation of the disease. Use of peptides that can directly target cancer cells without affecting normal cells (targeted therapy) is evolving as an alternate strategy to conventional chemotherapy. Peptide can be utilized directly as a cytotoxic agent through various mechanisms or can act as a carrier of cytotoxic agents and radioisotopes by specifically targeting cancer cells. Peptide-based hormonal therapy has been extensively studied and utilized for the treatment of breast and prostate cancers. Tremendous amount of clinical data is currently available attesting to the efficiency of peptide-based cancer vaccines. Combination therapy is emerging as an important strategy to achieve synergistic effects in fighting cancer as a single method alone may not be efficient enough to yield positive results. Combining immunotherapy with conventional therapies such as radiation and chemotherapy or combining an anticancer peptide with a nonpeptidic cytotoxic drug is an example of this emerging field. PMID:23316341

  10. Peptide-membrane Interactions by Spin-labeling EPR

    PubMed Central

    Smirnova, Tatyana I.; Smirnov, Alex I.

    2016-01-01

    Site-directed spin labeling (SDSL) in combination with Electron Paramagnetic Resonance (EPR) spectroscopy is a well-established method that has recently grown in popularity as an experimental technique, with multiple applications in protein and peptide science. The growth is driven by development of labeling strategies, as well as by considerable technical advances in the field, that are paralleled by an increased availability of EPR instrumentation. While the method requires an introduction of a paramagnetic probe at a well-defined position in a peptide sequence, it has been shown to be minimally destructive to the peptide structure and energetics of the peptide-membrane interactions. In this chapter, we describe basic approaches for using SDSL EPR spectroscopy to study interactions between small peptides and biological membranes or membrane mimetic systems. We focus on experimental approaches to quantify peptide-membrane binding, topology of bound peptides, and characterize peptide aggregation. Sample preparation protocols including spin-labeling methods and preparation of membrane mimetic systems are also described. PMID:26477253

  11. Electromembrane extraction of peptides.

    PubMed

    Balchen, Marte; Reubsaet, Léon; Pedersen-Bjergaard, Stig

    2008-06-20

    Rapid extraction of eight different peptides using electromembrane extraction (EME) was demonstrated for the first time. During an extraction time of 5 min, the model peptides migrated from a 500 microL aqueous acidic sample solution, through a thin supported liquid membrane (SLM) of an organic liquid sustained in the pores in the wall of a porous hollow fiber, and into a 25 microL aqueous acidic acceptor solution present inside the lumen of the hollow fiber. The driving force of the extraction was a 50 V potential sustained across the SLM, with the positive electrode in the sample and the negative electrode in the acceptor solution. The nature and the composition of the SLM were highly important for the EME process, and a mixture of 1-octanol and 15% di(2-ethylhexyl) phosphate was found to work properly. Using 1mM HCl as background electrolyte in the sample and 100 mM HCl in the acceptor solution, and agitation at 1050 rpm, enrichment up to 11 times was achieved. Recoveries were found to be dependent on the structure of the peptide, indicating that the polarity and the number of ionized groups were important parameters affecting the extraction efficiency. The experimental findings suggested that electromembrane extraction of peptides is possible and may be a valuable tool for future extraction of peptides. PMID:18479691

  12. Antimicrobial Peptides from Plants.

    PubMed

    Tam, James P; Wang, Shujing; Wong, Ka H; Tan, Wei Liang

    2015-01-01

    Plant antimicrobial peptides (AMPs) have evolved differently from AMPs from other life forms. They are generally rich in cysteine residues which form multiple disulfides. In turn, the disulfides cross-braced plant AMPs as cystine-rich peptides to confer them with extraordinary high chemical, thermal and proteolytic stability. The cystine-rich or commonly known as cysteine-rich peptides (CRPs) of plant AMPs are classified into families based on their sequence similarity, cysteine motifs that determine their distinctive disulfide bond patterns and tertiary structure fold. Cystine-rich plant AMP families include thionins, defensins, hevein-like peptides, knottin-type peptides (linear and cyclic), lipid transfer proteins, α-hairpinin and snakins family. In addition, there are AMPs which are rich in other amino acids. The ability of plant AMPs to organize into specific families with conserved structural folds that enable sequence variation of non-Cys residues encased in the same scaffold within a particular family to play multiple functions. Furthermore, the ability of plant AMPs to tolerate hypervariable sequences using a conserved scaffold provides diversity to recognize different targets by varying the sequence of the non-cysteine residues. These properties bode well for developing plant AMPs as potential therapeutics and for protection of crops through transgenic methods. This review provides an overview of the major families of plant AMPs, including their structures, functions, and putative mechanisms. PMID:26580629

  13. Antimicrobial Peptides from Plants

    PubMed Central

    Tam, James P.; Wang, Shujing; Wong, Ka H.; Tan, Wei Liang

    2015-01-01

    Plant antimicrobial peptides (AMPs) have evolved differently from AMPs from other life forms. They are generally rich in cysteine residues which form multiple disulfides. In turn, the disulfides cross-braced plant AMPs as cystine-rich peptides to confer them with extraordinary high chemical, thermal and proteolytic stability. The cystine-rich or commonly known as cysteine-rich peptides (CRPs) of plant AMPs are classified into families based on their sequence similarity, cysteine motifs that determine their distinctive disulfide bond patterns and tertiary structure fold. Cystine-rich plant AMP families include thionins, defensins, hevein-like peptides, knottin-type peptides (linear and cyclic), lipid transfer proteins, α-hairpinin and snakins family. In addition, there are AMPs which are rich in other amino acids. The ability of plant AMPs to organize into specific families with conserved structural folds that enable sequence variation of non-Cys residues encased in the same scaffold within a particular family to play multiple functions. Furthermore, the ability of plant AMPs to tolerate hypervariable sequences using a conserved scaffold provides diversity to recognize different targets by varying the sequence of the non-cysteine residues. These properties bode well for developing plant AMPs as potential therapeutics and for protection of crops through transgenic methods. This review provides an overview of the major families of plant AMPs, including their structures, functions, and putative mechanisms. PMID:26580629

  14. Maize EMBRYO SAC family peptides interact differentially with pollen tubes and fungal cells

    PubMed Central

    Woriedh, Mayada; Merkl, Rainer; Dresselhaus, Thomas

    2015-01-01

    EMBRYO SAC1-4 (ES1-4) peptides belong to the defensin subgroup of cysteine-rich peptides known to mediate pollen tube burst in Zea mays (maize). ES1-4 are reported here to also be capable of inhibiting germination and growth of the maize fungal pathogens Fusarium graminearum and Ustilago maydis at higher concentrations. Dividing the peptides into smaller pieces showed that a 15-amino-acid peptide located in a highly variable loop region lacking similarity to other defensins or defensin-like peptides binds to maize pollen tube surfaces, causing swelling prior to burst. This peptide fragment and a second conserved neighbouring fragment showed suppression of fungal germination and growth. The two peptides caused swelling of fungal cells, production of reactive oxygen species, and finally the formation of big vacuoles prior to burst at high peptide concentration. Furthermore, peptide fragments were found to bind differently to fungal cells. In necrotrophic F. graminearum, a peptide fragment named ES-d bound only at cell surfaces whereas the peptide ES-c bound at cell surfaces and also accumulated inside cells. Conversely, in biotrophic U. maydis, both peptide fragments accumulated inside cells, but, if applied at higher concentration, ES-c but not ES-d accumulated mainly in vacuoles. Mapping of peptide interaction sites identified amino acids differing in pollen tube burst and fungal response reactions. In summary, these findings indicate that residues targeting pollen tube burst in maize are specific to the ES family, while residues targeting fungal growth are conserved within defensins and defensin-like peptides. PMID:26071527

  15. Enhanced animal growth via ligand-regulated GHRH myogenic-injectable vectors

    NASA Technical Reports Server (NTRS)

    Draghia-Akli, Ruxandra; Malone, P. Brandon; Hill, Leigh Anne; Ellis, Kenneth M.; Schwartz, Robert J.; Nordstrom, Jeffrey L.

    2002-01-01

    Regulated animal growth occurred following a single electroporated injection of a mixture of two plasmids (10 microg of DNA), one expressing the GeneSwitch regulator protein, the other an inducible growth hormone releasing hormone (GHRH) gene, into the tibialis anterior muscles of adult SCID mice. Administration of the ligand mifepristone (MFP) up-regulated GHRH expression, as shown by elevations of IGF-I levels, and when MFP dosing was withdrawn, IGF-I returned to baseline levels. Five cycles of IGF-I induction were observed during a five-month period. Chronic MFP dosing for 25 days increased lean body mass, weight gain, and bone mineral density significantly compared with non-MFP treated controls. In summary, long-term drug-regulated GHRH expression was achieved following plasmid-based gene therapy, and chronic induction of GHRH expression in adult animals led to improvements in weight gain and body composition.

  16. Synthetic antibiofilm peptides.

    PubMed

    de la Fuente-Núñez, César; Cardoso, Marlon Henrique; de Souza Cândido, Elizabete; Franco, Octavio Luiz; Hancock, Robert E W

    2016-05-01

    Bacteria predominantly exist as multicellular aggregates known as biofilms that are associated with at least two thirds of all infections and exhibit increased adaptive resistance to conventional antibiotic therapies. Therefore, biofilms are major contributors to the global health problem of antibiotic resistance, and novel approaches to counter them are urgently needed. Small molecules of the innate immune system called host defense peptides (HDPs) have emerged as promising templates for the design of potent, broad-spectrum antibiofilm agents. Here, we review recent developments in the new field of synthetic antibiofilm peptides, including mechanistic insights, synergistic interactions with available antibiotics, and their potential as novel antimicrobials against persistent infections caused by biofilms. This article is part of a Special Issue entitled: Antimicrobial peptides edited by Karl Lohner and Kai Hilpert. PMID:26724202

  17. Signal peptide of cellulase.

    PubMed

    Yan, Shaomin; Wu, Guang

    2014-06-01

    Cellulase is an enzyme playing a crucial role in biotechnology industries ranging from textile to biofuel because of tremendous amount of cellulose produced in plant. In order to improve cellulase productivity, huge resource has been spent in search for good cellulases from microorganism in remote areas and in creation of ideal cellulase by engineering. However, not much attention is given to the secretion of cellulases from cell into extracellular space, where a cellulase plays its enzymatic role. In this minireview, the signal peptides, which lead secreted proteins to specific secretion systems and scatter in literature, are reviewed. The patterns of signal peptides are checked