Recent advances of GIP and future horizons
Publication date: Available online 12 December 2019Source: PeptidesAuthor(s): Jens Juul Holst, Mette Marie RosenkildeAbstractRecently GIP-GLP-1 co-agonists with powerful effects on glycemic control and body weight in patients with type 2 diabetes have been described. While such effects are the expected ones from a glucagonlike peptide-1 receptor agonist, similar contributions from the GIP component of the co-agonist would be surprising and contrast to the existing literature. Conventionally, GIP is thought of as an important incretin hormone regulating postprandial insulin secretion in glucose tolerant individuals, but suc...
Source: Peptides - December 14, 2019 Category: Biochemistry Source Type: research
Combinatorial inhibition of Angiotensin converting enzyme, Neutral endopeptidase and Aminopeptidase N by N-methylated peptides alleviates blood pressure and fibrosis in rat model of dexamethasone-induced hypertension
In this study, N-methylated peptide inhibitors F-N(Me)H-L, V-N(Me)F-R and R-N(Me)V-Y were synthesized against ACE, NEP and APN respectively, using their respective physiological substrates. F-N(Me)H-L inhibited ACE activity with an IC50 of 83 nmol/L, V-N(Me)F-R inhibited NEP activity with an IC50 of 1.173 μmol/L and R-N(Me)V-Y inhibited APN activity with an IC50 of 3.94 nmol/L respectively. Further, the anti-hypertensive effect of N-methylated peptides was evaluated using rat model of dexamethasone-induced hypertension. Individual peptides and their cocktail treatment were started from day 6 of the study period and ...
Source: Peptides - December 11, 2019 Category: Biochemistry Source Type: research
Cardiovascular Biology of the GIP Receptor
Publication date: Available online 5 December 2019Source: PeptidesAuthor(s): Amanda A. Greenwell, Jadin J. Chahade, John R. UssherAbstractGlucose-dependent insulinotropic polypeptide (GIP) is a gut hormone secreted primarily from enteroendocrine K cells in the duodenum and proximal jejunum following nutrient ingestion, primarily acting on islet β-cells to potentiate insulin secretion in a glucose-dependent manner. New discoveries of GIPR biology in adipose tissue, as well as findings that co-agonists for the glucagon-like peptide-1 receptor (GLP-1R) and GIPR induce greater weight loss than that seen with GLP-1R agonists a...
Source: Peptides - December 7, 2019 Category: Biochemistry Source Type: research
Molecular interactions of full-length and truncated GIP peptides with the GIP receptor – a comprehensive review
Publication date: Available online 3 December 2019Source: PeptidesAuthor(s): Maria Buur Nordskov Gabe, Wijnand J.C. van der Velden, Florent Xavier Smit, Lærke Smidt Gasbjerg, Mette Marie RosenkildeAbstractEnzymatic cleavage of endogenous peptides is a commonly used principle to initiate, modulate and terminate action for instance among cytokines and peptide hormones. The incretin hormones, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) and the related hormone glucagon-like peptide-2 (GLP-2) are all rapidly N-terminally truncated with severe loss of intrinsic activity. The most abund...
Source: Peptides - December 4, 2019 Category: Biochemistry Source Type: research
Endogenous Opiates and Behavior: 2017
Publication date: Available online 2 December 2019Source: PeptidesAuthor(s): Richard J. BodnarAbstractThis paper is the fortieth consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2017 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their...
Source: Peptides - December 4, 2019 Category: Biochemistry Source Type: research
Effects of Gastric Inhibitory Polypeptide (GIP) Immunoneutralization on Mouse Motor Coordination and Memory
Publication date: Available online 2 December 2019Source: PeptidesAuthor(s): Claire Y. Zhang, Michael O. Boylan, Hiroyuki Arakawa, M. Michael WolfeAbstractGastric inhibitory polypeptide (GIP) is a regulatory peptide expressed in the mammalian upper small intestine, and both GIP and its receptor (GIPR) are expressed in the cortex and hippocampus regions of the brain as well. While learning and memory deficits have been observed in GIPR-/- mice, the effects of peripheral GIP immunoneutralization on motor-coordination, learning, and memory have not been examined. In the present study, adult GIPR-/- mice (KO) and age-matched w...
Source: Peptides - December 2, 2019 Category: Biochemistry Source Type: research
C-type natriuretic peptide plasma levels and whole blood mRNA expression show different trends in adolescents with different degree of endothelial dysfunction
Publication date: Available online 30 November 2019Source: PeptidesAuthor(s): Silvia Del Ry, Manuela Cabiati, Vanessa Bianchi, Emioli Randazzo, Diego Peroni, Aldo Clerico, Giovanni FedericoAbstractC-type natriuretic peptide (CNP) is an endogenous adipogenesis regulator whose plasma levels in childhood are known, while no data are available on its expression. Our aim was to evaluate both CNP plasma levels and CNP system expression in whole blood obtained from normal-weight (N, n = 24) and obese (O, n = 16) adolescents (age:13.5 ± 0.4 years). Endothelial function was assessed measuring reactive hyperemia index (...
Source: Peptides - December 1, 2019 Category: Biochemistry Source Type: research
Selection and progression of unimolecular agonists at the GIP, GLP-1, and glucagon receptors as drug candidates
This report reviews recent progress in this area, with emphasis on what the initial clinical results demonstrate and what remains to be addressed. (Source: Peptides)
Source: Peptides - November 29, 2019 Category: Biochemistry Source Type: research
Ghrelin as an anti-inflammatory and protective agent in Ischemia/Reperfusion injury
Publication date: Available online 28 November 2019Source: PeptidesAuthor(s): K. Raghay, R. Akki, D. Bensaid, M. ErramiAbstractIschemia/reperfusion (I/R) continue to be the most frequent cause of damaged tissues. Injured tissues resulted from the first ischemic insult, which is determined by the interruption in the blood supply, followed by subsequent impairment induced by reperfusion. In addition, ischemia-reperfusion injury is mediated by tumor necrosis factor (TNF) and other cytokines that activate complements and proteases responsible for free radical production. However, earlier studies have reported the protective ro...
Source: Peptides - November 29, 2019 Category: Biochemistry Source Type: research
The role of GIP in α-cells and glucagon secretion
Publication date: Available online 27 November 2019Source: PeptidesAuthor(s): Kimberley El, Jonathan E. CampbellAbstractGlucose-dependent insulinotropic polypeptide (GIP) is an intestinally derived peptide that is secreted in response to feeding. The GIP receptor (GIPR) is expressed in many cell types involved in the regulation of metabolism, including α- and β-cells. Glucagon and insulin exert tremendous control over glucose metabolism. Thus, GIP action in islets strongly dictates metabolic control in the postprandial state. Loss of GIPR activity in β-cells is a characteristic of type 2 diabetes (T2D) which associates ...
Source: Peptides - November 28, 2019 Category: Biochemistry Source Type: research
Evidence for diversity in the activation of the Melanocortin 2 Receptor: a study on gar, elephant shark and stingray MC2Rs
Publication date: Available online 26 November 2019Source: PeptidesAuthor(s): Brianne E. Hoglin, Amanda Ferguson, Sheila Pahlavan, Robert M. DoresAbstractThe melanocortin-2 receptor (MC2R) is a critical component of the HPI and HPA axes of cartilaginous fishes, teleosts and tetrapods. Studies on teleost and tetrapod orthologs suggest two contact sites between ACTH and the receptor involving the following motifs on ACTH: H6F7R8W9 and K15K16R17R18P19. Using spotted gar (g) MC2R as a representative bony fish MC2R ortholog, we found that activation of gMC2R in Chinese Hamster Ovary (CHO) cells was diminished following stimulat...
Source: Peptides - November 26, 2019 Category: Biochemistry Source Type: research
The globus pallidus as a target for neuropeptides and endocannabinoids participating in central activities
Publication date: Available online 26 November 2019Source: PeptidesAuthor(s): Xin-Yi Chen, Yan Xue, Hua Chen, Lei ChenAbstractThe globus pallidus in the basal ganglia plays an important role in movement regulation. Neuropeptides and endocannabinoids are neuronal signalling molecules that influence the functions of the whole brain. Endocannabinoids, enkephalin, substance P, neurotensin, orexin, somatostatin and pituitary adenylate cyclase-activating polypeptides are richly concentrated in the globus pallidus. Neuropeptides and endocannabinoids exert excitatory or inhibitory effects in the globus pallidus mainly by modulatin...
Source: Peptides - November 26, 2019 Category: Biochemistry Source Type: research
C-type natriuretic peptide regulates the molecular components of the rainbow trout gill epithelium tight junction complex
Publication date: Available online 23 November 2019Source: PeptidesAuthor(s): Dennis Kolosov, Scott P. KellyAbstractFreshwater (FW) fish experience passive paracellular loss of ions into the surrounding environment across water-exposed epithelia such as the gill. The mitigation of paracellular ion loss is thought to be regulated by proteins of the tight junction (TJ) complex and in particular, the large superfamily of claudin (cldn) TJ proteins plays an important role. Transcript and protein levels of TJ proteins in teleosts are known to be under endocrine control of several important osmoregulatory hormones and the curren...
Source: Peptides - November 25, 2019 Category: Biochemistry Source Type: research
Liraglutide ameliorates palmitate-induced oxidative injury in islet microvascular endothelial cells through GLP-1 receptor/PKA and GTPCH1/eNOS signaling pathways
In conclusion, liraglutide ameliorates the PA-induced oxidative stress, apoptosis, and endothelin-1 secretion dysfunction in mouse IMECs through GLP-1R/PKA and GTPCH1/eNOS signaling pathways. (Source: Peptides)
Source: Peptides - November 25, 2019 Category: Biochemistry Source Type: research
GIP analogues augment bone strength by modulating bone composition in diet-induced obesity in mice
This study demonstrates that activation of skeletal GIPr by stable GIP analogues enhance bone strength in prediabetes and suggest that these analogues may be beneficial in the treatment of bone disease. (Source: Peptides)
Source: Peptides - November 23, 2019 Category: Biochemistry Source Type: research
