The antimicrobial and anti-endotoxic peptide AmyI-1-18 from rice α-amylase and its [N3L] analog promote angiogenesis and cell migration
In this study, we investigated the potential of these peptides to promote proliferation, angiogenesis (tube formation), and migration in human umbilical vein endothelial cells (HUVECs). Among five single amino acid-substituted analogs, [N3L]AmyI-1-18 induced cell proliferation in a concentration-dependent manner with similar efficacy to AmyI-1-18. In tube formation assays, AmyI-1-18 and [N3L]AmyI-1-18 had angiogenic activities at 1 μM and their effects were similar to those of LL-37. Moreover, scratch migration assays showed that AmyI-1-18, [N3L]AmyI-1-18, and LL-37 promote cell migration with optimum concentrations o...
Source: Peptides - May 1, 2018 Category: Biochemistry Source Type: research

Cell-penetrating peptides for siRNA delivery to glioblastomas
In conclusion, we have established an efficient non-covalently complexed carrier (PF14:TG1) for siRNA delivery to human glioblastoma cells (U87), showing a significant two-fold increase in gene-silencing efficiency compared to the parent peptide PF14 and also improved specificity to U87 cells compared to non-glioma targeted cells. Graphical abstract (Source: Peptides)
Source: Peptides - May 1, 2018 Category: Biochemistry Source Type: research

Distribution of MCH-containing fibers in the feline brainstem: Relevance for REM sleep regulation
Publication date: June 2018 Source:Peptides, Volume 104 Author(s): Alicia Costa, Santiago Castro-Zaballa, Patricia Lagos, Michael H. Chase, Pablo Torterolo Neurons that utilize melanin-concentrating hormone (MCH) as a neuromodulator are localized in the postero-lateral hypothalamus and incerto-hypothalamic area. These neurons project diffusely throughout the central nervous system and have been implicated in critical physiological processes, such as sleep. Unlike rodents, in the order carnivora as well as in humans, MCH exerts its biological functions through two receptors: MCHR-1 and MCHR-2. Hence, the cat is an optimal ...
Source: Peptides - May 1, 2018 Category: Biochemistry Source Type: research

New APETx-like peptides from sea anemone Heteractis crispa modulate ASIC1a channels
Publication date: June 2018 Source:Peptides, Volume 104 Author(s): Rimma Kalina, Irina Gladkikh, Pavel Dmitrenok, Oleg Chernikov, Sergey Koshelev, Aleksandra Kvetkina, Sergey Kozlov, Emma Kozlovskaya, Margarita Monastyrnaya Sea anemones are an abundant source of various biologically active peptides. The hydrophobic 20% ethanol fraction of tropical sea anemone Heteractis crispa was shown to contain at least 159 peptide compounds including neurotoxins, proteinase and α-amylase inhibitors, as well as modulators of acid-sensing ion channels (ASICs). The three new peptides, π-AnmTX Hcr 1b-2, -3, and -4 (41 aa) (short ...
Source: Peptides - May 1, 2018 Category: Biochemistry Source Type: research

A synthetic snake-venom-based tripeptide (Glu-Val-Trp) protects PC12 cells from MPP+ toxicity by activating the NGF-signaling pathway
Publication date: June 2018 Source:Peptides, Volume 104 Author(s): Carolina P. Bernardes, Neife A.G. Santos, Flavia M. Sisti, Rafaela Scalco Ferreira, Norival A. Santos-Filho, Adélia C.O. Cintra, Eduardo M. Cilli, Suely V. Sampaio, Antonio C. Santos Venom small peptides that target neurotrophin receptors might be beneficial in neurodegeneration, including Parkinsońs disease (PD). Their small size, ease of synthesis, structural stability and target selectivity make them important tools to overcome the limitations of endogenous neurotrophins as therapeutic agents. Additionally, they might be optimized to improve res...
Source: Peptides - May 1, 2018 Category: Biochemistry Source Type: research

Elevated plasma soluble (pro)renin receptor levels are associated with left ventricular remodeling and renal function in chronic heart faiure patients with reduced ejection fraction
In conclusion, high plasma s(P)RR levels are associated with left ventricular remodeling and, especially, with renal dysfunction. Therefore, s(P)RR is a promising evaluative indicator for the severity of HFrEF patients. (Source: Peptides)
Source: Peptides - April 14, 2018 Category: Biochemistry Source Type: research

Pituitary Adenylate Cyclase-Activating Polypeptide is a Potent Broad-Spectrum Antimicrobial Peptide: Structure-Activity Relationships
Publication date: Available online 11 April 2018 Source:Peptides Author(s): Charles G. Starr, Jerome L. Maderdrut, Jing He, David H. Coy, William C. Wimley Pituitary adenylate cyclase-activating polypeptide (PACAP) is a naturally occurring cationic peptide with potent immunosuppressant and cytoprotective activities. We now show that full length PACAP38 and to a lesser extent, the truncated form PACAP27, and the closely related vasoactive intestinal peptide (VIP) and secretin had antimicrobial activity against the Gram-negative bacteria Escherichia coli in the radial diffusion assay. PACAP38 was more potent than either the...
Source: Peptides - April 12, 2018 Category: Biochemistry Source Type: research

Computational Design and Experimental Characterization of a Novel β-Common Receptor Inhibitory Peptide
This study aimed to design and evaluate the efficacy of novel computationally designed βCR inhibitory peptides (βIP). These novel βIPs were designed based on a truncated portion of Helix-A from EPO, specifically residues 11 to 26 (VLERYLLEAKEAEKIT). Seven novel peptides (P1 to P7) were designed. Peptide 7 (P7), VLERYLHEAKHAEKIT, demonstrated the most robust inhibitory activity. We also report here the ability of P7 to inhibit βCR-induced nitric oxide (NO) production and angiogenesis in human umbilical vein endothelial cells (HUVECs). Specifically, we found that P7 βIP completely abolished EPO-induc...
Source: Peptides - April 8, 2018 Category: Biochemistry Source Type: research

The SAFE pathway is involved in the postconditioning mechanism of oxytocin in isolated rat heart
Publication date: Available online 7 April 2018 Source:Peptides Author(s): Mirali Polshekan, Vahid Khori, Ali Mohammad Alizadeh, Majid Ghayour-Mobarhan, Mohsen Saeidi, Yahya Jand, Maryam Rajaei, Gholamreza Farnoosh, Khadijeh Jamialahmadi Oxytocin (OT) has a postconditioning effect against the ischemia-reperfusion (I/R) injury. However, its precise cardioprotection mechanism at the early reperfusion phase remains under debate. Our previous study revealed that OT postconditioning (OTpost) is cardioprotective by activating the Reperfusion Injury Salvage Kinase (RISK) pathway. Therefore, the present study is aimed to determin...
Source: Peptides - April 8, 2018 Category: Biochemistry Source Type: research

Effects of truncation of the peptide chain on the secondary structure and bioactivities of palmitoylated anoplin
In this study, truncated analogues (pal-ano-9 to pal-ano-5) of palmitoylated anoplin (pal-anoplin) were synthesized to determine the effects of C-truncation on its bioactivities. Moreover, secondary structure of each analogue using circular dichroism (CD) spectroscopy was determined to correlate with bioactivities. Interestingly, pal-anoplin, pal-ano-9 and pal-ano-6 were helical in water, unlike anoplin. In contrast, pal-ano-8, pal-ano-7 and pal-ano-5, with polar amino acid residues at the C-terminus, were random coil in water. Nevertheless, all the peptides folded into helical structures in 30% trifluoroethanol/water (TFE...
Source: Peptides - April 1, 2018 Category: Biochemistry Source Type: research

An update on the role of irisin in the regulation of endocrine and metabolic functions
In conclusion, modification of circulating irisin level may help in the management of a variety of endocrine and metabolic disorders. Graphical abstract (Source: Peptides)
Source: Peptides - March 31, 2018 Category: Biochemistry Source Type: research

Bradykinin-potentiating peptide-10c, an argininosuccinate synthetase activator, protects against h2o2-induced oxidative stress in sh-sy5y neuroblastoma cells
Publication date: Available online 29 March 2018 Source:Peptides Author(s): Samyr Machado Querobino, César Augusto João Ribeiro, Carlos Alberto-Silva Bradykinin-potentiating peptides (BPPs – 5a, 7a, 9a, 10c, 11e, and 12b) of Bothrops jararaca (Bj) were described as argininosuccinate synthase (AsS) activators, improving L-arginine availability. Agmatine and polyamines, which are L-arginine metabolism products, have neuroprotective properties. Here, we investigated the neuroprotective effects of low molecular mass fraction from Bj venom (LMMF) and two synthetic BPPs (BPP-10c, <ENWPHPQIPP; B...
Source: Peptides - March 30, 2018 Category: Biochemistry Source Type: research

Mechanism of adrenomedullin 2/intermedin mediated vasorelaxation in rat main pulmonary artery
In this study, we aimed to investigate the exact mechanism and the role of BKCa and calcium channels on the vasorelaxant effect of AM2/IMD in rat PA. Changes in the AM2/IMD-mediated vasorelaxation were evaluated in the presence of various inhibitors. CGRP(8-37) (10−6 M), L-NAME (10−4 M), ODQ (10−5 M), SQ22536 (10−4 M), H89 (10−6 M), TEA (10−2 M), iberiotoxin (3 × 10−7 M), and verapamil (10−5 M), all partly or completely inhibited the vasorelaxation. The relaxation was also abolished by removal of the endothelium, or in KCl precontracted PAs. AM2/IMD ...
Source: Peptides - March 27, 2018 Category: Biochemistry Source Type: research

NMR structures in different membrane environments of three ocellatin peptides isolated from Leptodactylus labyrinthicus
Publication date: Available online 26 March 2018 Source:Peptides Author(s): Karla A.G.G. Gomes, Daniel M. dos Santos, Virgílio M. Santos, Dorila Piló-Veloso, Higor M. Mundim, Leticia V. Rodrigues, Luciano M. Lião, Rodrigo M. Verly, Maria Elena de Lima, Jarbas M. Resende The peptides ocellatin-LB1, −LB2 and −F1 have previously been isolated from anurans of the Leptodactylus genus and the sequences are identical from residue 1 to 22, which correspond to ocellatin-LB1 sequence (GVVDILKGAAKDIAGHLASKVM-NH2), whereas ocellatin-LB2 carries an extra N and ocellatin-F1 extra NKL residues at their C...
Source: Peptides - March 27, 2018 Category: Biochemistry Source Type: research

Actinobacteria –Derived peptide antibiotics since 2000
Publication date: May 2018 Source:Peptides, Volume 103 Author(s): Pengchao Zhao, Yun Xue, Weina Gao, Jinghua Li, Xiangyang Zu, Dongliao Fu, Shuxiao Feng, Xuefei Bai, Yanjun Zuo, Ping Li Members of the Actinobacteria, including Streptomyces spp., Kutzneria sp. Actinoplanes spp., Actinomycete sp., Nocardia sp., Brevibacteriumsp.,Actinomadura spp., Micromonospora sp., Amycolatopsis spp., Nonomuraea spp., Nocardiopsis spp., Marinactinospora sp., Rhodococcus sp., Lentzea sp., Actinokineospora sp., Planomonospora sp., Streptomonospora sp., and Microbacterium sp., are an important source of structurally diverse classes of short ...
Source: Peptides - March 26, 2018 Category: Biochemistry Source Type: research

Alamandine injected into the paraventricular nucleus increases blood pressure and sympathetic activation in spontaneously hypertensive rats
Publication date: Available online 23 March 2018 Source:Peptides Author(s): Yi-Hui Shen, Xi-Ru Chen, Chun-Xi Yang, Bo-Xun Liu, Peng Li Alamandine is a newly discovered new component of the renin-angiotensin (Ang) system (RAS) that has been shown to exert vasoactive effects in some areas of the nervous system. The present study investigated whether administration of alamandine to the hypothalamic paraventricular nucleus (PVN) modulates blood pressure and sympathetic activity. Mean arterial pressure (MAP) and renal sympathetic nerve activity (RSNA) were recorded in anaesthetized rats. PVN microinjection of alamandine increa...
Source: Peptides - March 24, 2018 Category: Biochemistry Source Type: research

Adrenomedullin: Continuing to explore cardioprotection
Publication date: Available online 22 March 2018 Source:Peptides Author(s): Toshihiro Tsuruda, Johji Kato, Kenji Kuwasako, Kazuo Kitamura Adrenomedullin (AM), a peptide isolated from an extract of human pheochromocytoma, comprises 52 amino acids with an intramolecular disulfide bond and amidation at the carboxy-terminus. AM is present in various tissues and organs in rodents and humans, including the heart. The peptide concentration increases with cardiac hypertrophy, acute myocardial infarction, and overt heart failure in the plasma and the myocardium. The principal function of AM in the cardiovascular system is the regu...
Source: Peptides - March 23, 2018 Category: Biochemistry Source Type: research

Detection and quantitation of irisin in human cerebrospinal fluid by tandem mass spectrometry
Publication date: Available online 21 March 2018 Source:Peptides Author(s): Qingwei Ruan, Limin Zhang, Jian Ruan, Xixue Zhang, Jie Chen, Cheng Ma, Zhuowei Yu The myokine irisin can cross the blood brain barrier and act as a neurokine to protect brain function during endurance exercise. However, the mechanism of transport from the blood to cerebrospinal fluid is unknown. Irisin has been detected in rodent and human brain and human cerebrospinal fluid by using commercial antibodies and enzyme linked immunosorbent assay kits. However, as human FNDC5 has an atypical translation start codon, some studies have questioned the sp...
Source: Peptides - March 22, 2018 Category: Biochemistry Source Type: research

The anuran skin peptide bradykinin mediates its own absorption across epithelial barriers of the digestive tract
This study provides evidence that bradykinin, a widespread peptide toxin in anurans (frogs), is capable to pass through epithelial barriers independent of this delivery system. We quantified bradykinin peptides secreted by Bombina orientalis during acute stress, and found that at biologically relevant concentrations, bradykinin passage across model epithelia occurs even in the absence of AMPs. Monitoring of transepithelial electric resistance showed that bradykinin treatment caused a subtle yet prolonged reduction in barrier function, indicating that the peptide itself is capable to increase the permeability of epithelia. ...
Source: Peptides - March 21, 2018 Category: Biochemistry Source Type: research

Actinobacteria-Derived Peptide Antibiotics since 2000
Publication date: Available online 19 March 2018 Source:Peptides Author(s): Pengchao Zhao, Yun Xue, Weina Gao, Jinghua Li, Xiangyang Zu, Dongliao Fu, Shuxiao Feng, Xuefei Bai, Yanjun Zuo, Ping Li Members of the Actinobacteria, including Streptomyces spp., Kutzneria sp. Actinoplanes spp., Actinomycete sp., Nocardia sp., Brevibacteriumsp.,Actinomadura spp., Micromonospora sp., Amycolatopsis spp., Nonomuraea spp., Nocardiopsis spp., Marinactinospora sp., Rhodococcus sp., Lentzea sp., Actinokineospora sp., Planomonospora sp., Streptomonospora sp., and Microbacterium sp., are an important source of structurally diverse classes...
Source: Peptides - March 20, 2018 Category: Biochemistry Source Type: research

Functional characterization of mosquito short neuropeptide F receptors
Publication date: Available online 14 March 2018 Source:Peptides Author(s): Peter Christ, Sharon R. Hill, Joachim Schachtner, Frank Hauser, Rickard Ignell Mosquito blood feeding transiently inhibits sugar- and host seeking through neuropeptide signaling. Short neuropeptide F (sNPF) is one of the neuromodulators involved in this regulation. Here, we identified the genes for the sNPF precursor and the sNPF receptor in the southern house mosquito, Culex quinquefasciatus. Comparative analyses are made with the genes of the sNPF precursor and receptor from two other important vectors, Aedes aegypti and Anopheles coluzzii. We f...
Source: Peptides - March 16, 2018 Category: Biochemistry Source Type: research

Crustacean cardioactive peptide (CCAP) of the oriental fruit fly, Bactrocera dorsalis (Diptera: Tephritidae): Molecular characterization, distribution and its potential roles in larva-pupa ecdysis
Publication date: Available online 15 March 2018 Source:Peptides Author(s): Yan Shi, Tian-Yuan Liu, Yu-Xia Pei, Hong-Bo Jiang, Wei Dou, Guy Smagghe, Jin-Jun Wang Insects must undergo ecdysis for successful development and growth, and the crustacean cardioactive peptide (CCAP) is one of the most important hormone in this process. Here we reported a cDNA encoding for the CCAP precursor cloned from the oriental fruit fly, Bactrocera dorsalis, a most destructive insect pest of agriculture. The CCAP mature peptide (PFCNAFTGC-NH2) of B. dorsalis was generated by post-translational processing and found to be highly comparable wi...
Source: Peptides - March 16, 2018 Category: Biochemistry Source Type: research

Seasonal variations in cellular expression of neuropeptide Y (NPY) in testis of the catfish, Clarias batrachus and its potential role in regulation of steroidogenesis
This study for the first time demonstrates the existence of NPY peptide at cellular levels in fish testis, which stimulates androgen production by acting directly at testicular level. (Source: Peptides)
Source: Peptides - March 14, 2018 Category: Biochemistry Source Type: research

Identification of evolutionarily conserved residues required for the bioactivity of a pedal peptide/orcokinin-type neuropeptide
In conclusion, we have identified key residues required for the bioactivity of a PP/OK-type neuropeptide (SMP), including hydrophobic residues located in the N- and C-terminal regions that are conserved in PP/OK-type peptides from other phyla as well as core residues that are conserved in echinoderm PP/OK-type peptides. Graphical abstract (Source: Peptides)
Source: Peptides - March 11, 2018 Category: Biochemistry Source Type: research

Distribution of pituitary adenylate cyclase-activating polypeptide 2 in zebrafish brain
This study aims to determine the distribution of these PACAPs and their mRNAs in zebrafish. We generated a zebrafish PACAP2-specific antibody. Using real-time PCR, we observed that adcyap1b mRNA was primarily localized in the brain, with the highest level in the telencephalon, followed by the diencephalon. Using immunostaining of brain tissue samples, PACAP2 immunoreactivity was observed mainly in the telencephalon, hypothalamus, and cerebellum, and the immunopositive fibers formed a line to the habenula. PACAP2-immunopositive cells were observed in the ventral and dorsal regions of the telencephalon and in the hypothalami...
Source: Peptides - March 11, 2018 Category: Biochemistry Source Type: research

The ghrelin paradox in the control of equine chondrocyte function: the good and the bad
Publication date: Available online 8 March 2018 Source:Peptides Author(s): Serena Ceriotti, Anna Lange Consiglio, Lavinia Casati, Fausto Cremonesi, Valeria Sibilia, Francesco Ferrucci Increasing evidence suggests a role for ghrelin in the control of articular inflammatory diseases like osteoarthritis (OA). In the present study we examined the ability of ghrelin to counteract LPS-induced necrosis and apoptosis of chondrocytes and the involvement of GH secretagogue receptor (GHS-R)1a in the protective action of ghrelin. The effects of ghrelin (10−7–10−11 mol/L) on equine primary cultured chondrocytes via...
Source: Peptides - March 9, 2018 Category: Biochemistry Source Type: research

Need for more holistic therapeutic and management strategies to understand the causal or correlative link of the A β amyloid pathway with Alzheimer’s disease for a more efficiënt treatment
Publication date: Available online 7 March 2018 Source:Peptides Author(s): Jean-Pierre Timmermans (Source: Peptides)
Source: Peptides - March 8, 2018 Category: Biochemistry Source Type: research

Vasopressin V1a receptors are present in the carotid body and contribute to the control of breathing in male Sprague-Dawley rats
Publication date: Available online 7 March 2018 Source:Peptides Author(s): Tymoteusz Żera, Jacek Przybylski, Tomasz Grygorowicz, Kaja Kasarełło, Martyna Podobińska, Dagmara Mirowska-Guzel, Agnieszka Cudnoch-Jędrzejewska Vasopressin (AVP) maintains body homeostasis by regulating water balance, cardiovascular system and stress response. AVP inhibits breathing through central vasopressin 1a receptors (V1aRs). Chemoreceptors within carotid bodies (CBs) detect chemical and hormonal signals in the bloodstream and provide sensory input to respiratory and cardiovascular centers of the brainstem. In the study we investigated ...
Source: Peptides - March 8, 2018 Category: Biochemistry Source Type: research

Serum proatrial natriuretic peptide concentrations during oral glucose-induced acute hyperinsulinemia in lean and obese men
In conclusion, during an oral glucose challenge, serum MR-proANP concentrations drop significantly in obese individuals, but the time-course curves of MR-proANP do not display a reciprocal relationship to the time-course curves of insulin. (Source: Peptides)
Source: Peptides - March 8, 2018 Category: Biochemistry Source Type: research

The peptide toxin δ-hexatoxin-MrIX inhibits fast inactivation of NaVs in mouse cerebellar granule cells
This study has characterized a 44-amino acid peptide toxin, δ-hexatoxin-MrIX (δ-HXTX-MrIX), from the venom of the spider Macrothele raveni. δ-hexatoxin-MrIX potently inhibited the fast inactivation of NaVs in mouse cerebellar granule cells (CGCs) with an EC50 of 35.3 ± 5.9 nM. The toxin shifted both the steady-state activation and the steady-state inactivation curves of CGC NaVs to the hyperpolarized direction. δ-hexatoxin-MrIX also acted on NaV1.3 and NaV1.4 channels heterologously expressed in HEK293T cells, as well a s on NaVs in acutely isolated cockroach DUM neurons. However, the N...
Source: Peptides - March 7, 2018 Category: Biochemistry Source Type: research

Extraction and identification of α-amylase inhibitor peptides from Nephelium lappacheum and Nephelium mutabile seed protein using gastro-digestive enzymes
Publication date: Available online 3 March 2018 Source:Peptides Author(s): Natashya Anak Evaristus, Wan Nadiah Wan Abdullah, Chee-Yuen Gan The potential of N. lappacheum and N. mutabile seed as a source of α-amylase inhibitor peptides was explored based on the local traditional practice of using the seed. Different gastro-digestive enzymes (i.e. pepsin or chymotrypsin) or a sequential digestion were used to extract the peptides. The effects of digestion time and enzyme to substrate (E:S) ratio on the α-amylase inhibitory activity were investigated. Results showed that chymotrypsin was effective in producing th...
Source: Peptides - March 4, 2018 Category: Biochemistry Source Type: research

Identification and Screening of Potent Antimicrobial Peptides in Arthropod Genomes
Publication date: Available online 1 March 2018 Source:Peptides Author(s): Deepesh Duwadi, Anishma Shrestha, Binyam Yilma, Itamar Kozlovski, Munaya Sa-eed, Nikesh Dahal, James Jukosky Using tBLASTn and BLASTp searches, we queried recently sequenced arthropod genomes and expressed sequence tags (ESTs) using a database of known arthropod cecropins, defensins, and attacins. We identified and synthesized 6 potential AMPs and screened them for antimicrobial activity. Using radial diffusion assays and microtiter antimicrobial assays, we assessed the in vitro antimicrobial effects of these peptides against several human pathogen...
Source: Peptides - March 2, 2018 Category: Biochemistry Source Type: research

Automatic procedures for the synthesis of difficult peptides using oxyma as activating reagent: a comparative study on the use of bases and on different deprotection and agitation conditions.
Publication date: Available online 24 February 2018 Source:Peptides Author(s): A. Caporale, N. Doti, A. Monti, A. Sandomenico, M. Ruvo Solid-Phase Peptide Synthesis (SPPS) is a rapid and efficient methodology for the chemical synthesis of peptides and small proteins. However, the assembly of peptide sequences classified as “difficult” poses severe synthetic problems in SPPS for the occurrence of extensive aggregation of growing peptide chains which often leads to synthesis failure. In this framework, we have investigated the impact of different synthetic procedures on the yield and final purity of three well-k...
Source: Peptides - February 25, 2018 Category: Biochemistry Source Type: research

Corrigendum to “Structure, folding and stability of a minimal homologue from Anemonia sulcata of the sea anemone potassium channel blocker ShK” [Peptides 99 (2018) 169–178]
Publication date: March 2018 Source:Peptides, Volume 101 Author(s): Bankala Krishnarjuna, Christopher A. MacRaild, Punnepalli Sunanda, Rodrigo A.V. Morales, Steve Peigneur, Jason Macrander, Heidi H. Yu, Marymegan Daly, Srinivasarao Raghothama, Vikas Dhawan, Satendra Chauhan, Jan Tytgat, Michael W. Pennington, Raymond S. Norton (Source: Peptides)
Source: Peptides - February 24, 2018 Category: Biochemistry Source Type: research

Nesfatin-1 and visfatin expression is associated with reduced atherosclerotic disease risk in patients with rheumatoid arthritis
We examined the potential impact of nesfatin and visfatin on atherosclerotic disease in 232 (113 black and 119 white) consecutive rheumatoid arthritis (RA) patients from 2 centers. Independent relationships of nesfatin and visfatin concentrations with metabolic risk factors, endothelial activation, carotid atherosclerosis and altered plaque stability were determined in multivariable regression models. Rheumatoid factor (RF) positivity was associated with both nesfatin (β = 0.650, p < 0.0001) and visfatin levels (β = 0.157, p = 0.03). Visfatin concentrations were related to increased diastol...
Source: Peptides - February 22, 2018 Category: Biochemistry Source Type: research

Stapled truncated orexin peptides as orexin receptor agonists
In this study, we set out to stabilize the α‐helical conformation of orexin‐A15–33 via peptide stapling at four different sites. At a suggested hinge region, we varied the length of the cross-linker as well as replaced the staple with two α-aminoisobutyric acid residues. Modifications close to the peptide C‐terminus, which is crucial for activity, were not allowed. However, central and N‐terminal modifications yielded bioactive peptides, albeit with decreased potencies. This provides evidence that the orexin receptors can accommodate and be activated by α-helical peptides. The decrease in po...
Source: Peptides - February 22, 2018 Category: Biochemistry Source Type: research

Relationship between cerebrospinal fluid concentrations of orexin A/hypocretin-1 and body composition in humans
Publication date: Available online 19 February 2018 Source:Peptides Author(s): João C.P. Santiago, Markus Otto, Werner Kern, Paul Christian Baier, Manfred Hallschmid The hypothalamic neuropeptide orexin A (hypocretin-1) is a key signal in sleep/wake regulation and promotes food intake. We investigated the relationship between cerebrospinal fluid orexin A concentrations and body composition in non-narcoleptic human subjects with a wide range of body weight to gain insight into the role of orexin A in human metabolism. We collected cerebrospinal fluid and blood samples and measured body composition by bioelectric imp...
Source: Peptides - February 20, 2018 Category: Biochemistry Source Type: research

Gastrointestinal Hormones in Regulation of Memory
Publication date: Available online 18 February 2018 Source:Peptides Author(s): Anwesha Mandal, Kedar S. Prabhavalkar, Lokesh K. Bhatt The connection between the gastrointestinal hormones and the brain has been established many years ago. This relation is termed the gut-brain axis (GBA). The GBA is a bidirectional communication which not only regulates gastrointestinal homeostasis but is also linked with higher emotional and cognitive functions. Hypothalamus plays a critical role in the regulation of energy metabolism, nutrient partitioning and control of feeding behaviors. Various gut hormones are released inside the gast...
Source: Peptides - February 19, 2018 Category: Biochemistry Source Type: research

Roles of the insulin signaling pathway in insect development and organ growth
Publication date: Available online 16 February 2018 Source:Peptides Author(s): Xianyu Lin, Guy Smagghe Organismal development is a complex process as it requires coordination of many aspects to grow into fit individuals, such as the control of body size and organ growth. Therefore, the mechanisms of precise control of growth are essential for ensuring the growth of organisms at a correct body size and proper organ proportions during development. The control of the growth rate and the duration of growth (or the cessation of growth) are required in size control. The insulin signaling pathway and the elements involved are es...
Source: Peptides - February 17, 2018 Category: Biochemistry Source Type: research

Gut hormone polyagonists for the treatment of type 2 diabetes
Publication date: February 2018 Source:Peptides, Volume 100 Author(s): Sara J. Brandt, Anna Götz, Matthias H. Tschöp, Timo D. Müller Chemical derivatives of the gut-derived peptide hormone glucagon-like peptide 1 (GLP-1) are among the best-in-class pharmacotherapies to treat obesity and type 2 diabetes. However, GLP-1 analogs have modest weight lowering capacity, in the range of 5–10%, and the therapeutic window is hampered by dose-dependent side effects. Over the last few years, a new concept has emerged: combining the beneficial effects of several key metabolic hormones into a single molecular entit...
Source: Peptides - February 13, 2018 Category: Biochemistry Source Type: research

Glucose-dependent insulinotropic polypeptide (GIP) receptor antagonists as anti-diabetic agents
Publication date: February 2018 Source:Peptides, Volume 100 Author(s): Lærke Smidt Gasbjerg, Maria Buur Nordskov Gabe, Bolette Hartmann, Mikkel Bring Christensen, Filip Krag Knop, Jens Juul Holst, Mette Marie Rosenkilde Glucose-dependent insulinotropic polypeptide (GIP) is an intestinal hormone with a broad range of physiological actions. In the postprandial state, the hormone stimulates insulin secretion and during eu- and hypoglycemia, it stimulates glucagon secretion. In addition, GIP increases triacylglycerol (TAG) uptake in adipose tissue and decreases bone resorption. However, the importance of these actions i...
Source: Peptides - February 13, 2018 Category: Biochemistry Source Type: research

Tissue expression of DPP-IV in obesity-diabetes and modulatory effects on peptide regulation of insulin secretion
Publication date: February 2018 Source:Peptides, Volume 100 Author(s): Aine M. McKillop, Claire L. Stevenson, Brian M. Moran, Yasser H.A. Abdel-Wahab, Peter R. Flatt Dipeptidyl peptidase type 4 (DPP-4) inhibitors represent an important class of glucose-lowering drug for type 2 diabetes. DPP-4 enzyme activity has been observed to be significantly altered in type 2 diabetes. Here, the role of DPP-4 was examined in a high fat fed (HFF) mouse model of insulin resistance. HFF mice had an increased bodyweight (p < .01), were hyperglycaemic (p < .01) and hyperinsulinaemic (p < .05). Compared to n...
Source: Peptides - February 13, 2018 Category: Biochemistry Source Type: research

Dipeptidyl peptidase inhibitor therapy in type 2 diabetes: Control of the incretin axis and regulation of postprandial glucose and lipid metabolism
Publication date: February 2018 Source:Peptides, Volume 100 Author(s): Erin E. Mulvihill Dipeptidyl peptidase 4 (DPP4) is a widely expressed, serine protease which regulates the bioactivity of many peptides through cleavage and inactivation including the incretin hormones, glucagon like peptide −1 (GLP-1) and glucose dependent insulinotropic polypeptide (GIP). Inhibitors of DPP4 are used therapeutically to treat patients with Type 2 Diabetes Mellitus (T2DM) as they potentiate incretin action to regulate islet hormone secretion and improve glycemia and post-prandial lipid excursions. The widespread clinical use of DP...
Source: Peptides - February 13, 2018 Category: Biochemistry Source Type: research

Peptide degradation and the role of DPP-4 inhibitors in the treatment of type 2 diabetes
Publication date: February 2018 Source:Peptides, Volume 100 Author(s): Carolyn F. Deacon Dipeptidyl peptidase-4 (DPP-4) inhibitors are now a widely used, safe and efficacious class of antidiabetic drugs, which were developed prospectively using a rational drug design approach based on a thorough understanding of the endocrinology and degradation of glucagon-like peptide-1 (GLP-1). GLP-1 is an intestinal hormone with potent insulinotropic and glucagonostatic effects and can normalise blood glucose levels in patients with type 2 diabetes, but the native peptide is not therapeutically useful because of its inherent metabolic...
Source: Peptides - February 13, 2018 Category: Biochemistry Source Type: research

Insulin and IGF-1 receptor autocrine loops are not required for Exendin-4 induced changes to pancreatic β-cell bioenergetic parameters and metabolism in BRIN-BD11 cells
Publication date: February 2018 Source:Peptides, Volume 100 Author(s): Jordan Rowlands, Vinicius Cruzat, Rodrigo Carlessi, Philip Newsholme Pharmacological long lasting Glucagon-like peptide-1 (GLP-1) analogues, such as Exendin-4, have become widely used diabetes therapies. Chronic GLP-1R stimulation has been linked to β-cell protection and these pro-survival actions of GLP-1 are dependent on the activation of the mammalian target of rapamycin (mTOR) leading to accumulation of Hypoxia inducible factor 1 alpha (HIF-1α). Recent studies from our lab indicate that prolonged GLP-1R stimulation promotes metabolic rep...
Source: Peptides - February 13, 2018 Category: Biochemistry Source Type: research

Intestinal peptide changes after bariatric and minimally invasive surgery: Relation to diabetes remission
Publication date: February 2018 Source:Peptides, Volume 100 Author(s): Lidia Castagneto Gissey, James Casella Mariolo, Geltrude Mingrone Bariatric surgery is very effective in achieving and maintaining weight loss but it is also associated with improvement of obesity metabolic complications, primarily type 2 diabetes (T2D). Remission of T2D or at least a net improvement of glycemic control persists for at least 5 years. The bypass of duodenum and of the first portion of the jejunum up to the Treitz ligament as in Roux-en-Y Gastric Bypass (RYGB), or the bypass of the duodenum, the entire jejunum and the first tract of the ...
Source: Peptides - February 13, 2018 Category: Biochemistry Source Type: research

Incretin-based therapy for the treatment of bone fragility in diabetes mellitus
Publication date: February 2018 Source:Peptides, Volume 100 Author(s): Guillaume Mabilleau, Benoît Gobron, Béatrice Bouvard, Daniel Chappard Bone fractures are common comorbidities of type 2 diabetes mellitus (T2DM). Bone fracture incidence seems to develop due to increased risk of falls, poor bone quality and/or anti-diabetic medications. Previously, a relation between gut hormones and bone has been suspected. Most recent evidences suggest indeed that two gut hormones, namely glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), may control bone remodeling and quality. The G...
Source: Peptides - February 13, 2018 Category: Biochemistry Source Type: research

GLP-1 receptor agonists show neuroprotective effects in animal models of diabetes
Publication date: February 2018 Source:Peptides, Volume 100 Author(s): Victor A. Gault, Christian Hölscher Enzyme-resistant receptor agonists of the incretin hormone glucagon-like peptide-1 (GLP-1) have shown positive therapeutic effects in people with type 2 diabetes mellitus (T2DM). T2DM has detrimental effects on brain function and impairment of cognition and memory formation has been described. One of the underlying mechanisms is most likely insulin de-sensitization in the brain, as insulin improves cognitive impairments and enhances learning. Treatment with GLP-1 receptor agonists improves memory formation and i...
Source: Peptides - February 13, 2018 Category: Biochemistry Source Type: research

Glucagon-like peptide-1 receptor mediated control of cardiac energy metabolism
Publication date: February 2018 Source:Peptides, Volume 100 Author(s): Rami Al Batran, Malak Almutairi, John R. Ussher Glucagon-like peptide-1 receptor (GLP-1R) agonists are frequently used to improve glycemia in patients with type 2 diabetes (T2D). Recent data from cardiovascular outcomes trials for the GLP-1R agonists, liraglutide and semaglutide, have also demonstrated significant reductions in death rates from cardiovascular causes in patients with T2D. As cardiovascular death is the number one cause of death in patients with T2D, understanding the mechanisms by which GLP-1R agonists such as liraglutide and semaglutid...
Source: Peptides - February 13, 2018 Category: Biochemistry Source Type: research

A role for Glucagon-Like Peptide-1 in the regulation of β-cell autophagy
Publication date: February 2018 Source:Peptides, Volume 100 Author(s): Catherine Arden Autophagy is a highly conserved intracellular recycling pathway that serves to recycle damaged organelles/proteins or superfluous nutrients during times of nutritional stress to provide energy to maintain intracellular homeostasis and sustain core metabolic functions. Under these conditions, autophagy functions as a cell survival mechanism but impairment of this pathway can lead to pro-death stimuli. Due to their role in synthesising and secreting insulin, pancreatic β-cells have a high requirement for robust degradation pathways. ...
Source: Peptides - February 13, 2018 Category: Biochemistry Source Type: research