Peptide Alpha Research Articles

Correlation of gene polymorphism of interleukin 4 receptor alpha peptide chain and total serum IgE levels in asthmatic children in Guiyang area

To explore the correlation of gene polymorphism of interleukin 4 receptor alpha chain (IL-4Rα) and total serum IgE levels in children of bronchial asthma in Guiyang area. A total of 160 asthmatic children at Affiliated Hospital, Guiyang Medical College from August 2010 to February 2011 were selected as asthma group. There were 96 males and 64 females with an average age of (6.9 ± 3.3) years. During the same period, 143 healthy children from outpatient physical examination center of this hospital were chosen as control group. There were 75 males and 68 females with an average age of (4.9 ± 3.9) years. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and allele-specific polymerase chain reaction (AS-PCR) were used to determine the polymorphisms of Q576R on exon 12 and I75V on exon 5 of IL-4Rα in both groups. The total serum IgE levels were determined by enzyme-linked immune sorbent assay (ELISA). Comparisons of two groups were made for genotype and allele frequency, serum total IgE and different genotypes, different groups of total serum IgE levels. Three genotypes of AA, AG and GG existed on Q576R and I75V loci between two groups. The genotypic frequencies of two loci had significant differences in two groups (χ(2) = 30.972, 16.776, both P < 0.001). The subjects with variant allele on Q576R and I75V loci had higher risks for asthma than those without variant allele (χ(2) = 33.236, 13.845, both P < 0.001). The total serum levels of IgE in asthma group were higher than those in control group ((312 ± 297) vs (61 ± 48) U/ml, t = 9.959, P < 0.001). However, these three genotypes of two loci showed no significant inter-group difference (all P > 0.05). In mutation allele carriers and non-carriers of Q576R locus, total IgE levels showed no significant difference (t = -0.028, 1.279; P = 0.978, 0.203). Differences in total IgE levels between I75V polymorphic variant allele carriers and non-carriers were also not statistically significant in control group (t = -0.763, P = 0.447). However, in asthma group, total IgE levels of I75V polymorphic variant allele carriers were significantly higher than those of non-carriers (t = -2.112, P = 0.036). The 576 and 75 loci of IL-4Rα are important candidate genes of asthmatic children in Guiyang area. And the serum total IgE levels of variant allele G at 75 locus in IL-4Rα are higher than those without it.

Angiotensin I-converting enzyme (ACE) inhibitory activity and ACE inhibitory peptides of salmon (Salmo salar) protein hydrolysates obtained by human and porcine gastrointestinal enzymes.

The objectives of the present study were two-fold: first, to detect whether salmon protein fractions possess angiotensin I-converting enzyme (ACE) inhibitory properties and whether salmon proteins can release ACE inhibitory peptides during a sequential in vitro hydrolysis (with commercial porcine enzymes) and ex vivo digestion (with human gastrointestinal enzymes). Secondly, to evaluate the ACE inhibitory activity of generated hydrolysates. A two-step ex vivo and in vitro model digestion was performed to simulate the human digestion process. Salmon proteins were degraded more efficiently by porcine enzymes than by human gastrointestinal juices and sarcoplasmic proteins were digested/hydrolyzed more easily than myofibrillar proteins. The ex vivo digested myofibrillar and sarcoplasmic duodenal samples showed IC50 values (concentration required to decrease the ACE activity by 50%) of 1.06 and 2.16 mg/mL, respectively. The in vitro hydrolyzed myofibrillar and sarcoplasmic samples showed IC50 values of 0.91 and 1.04 mg/mL, respectively. Based on the results of in silico studies, it was possible to identify 9 peptides of the ex vivo hydrolysates and 7 peptides of the in vitro hydrolysates of salmon proteins of 11 selected peptides. In both types of salmon hydrolysates, ACE-inhibitory peptides IW, IY, TVY and VW were identified. In the in vitro salmon protein hydrolysates an ACE-inhibitory peptides VPW and VY were also detected, while ACE-inhibitory peptides ALPHA, IVY and IWHHT were identified in the hydrolysates generated with ex vivo digestion. In our studies, we documented ACE inhibitory in vitro effects of salmon protein hydrolysates obtained by human and as well as porcine gastrointestinal enzymes.

Abstract 5077: Anti-angiogenesis and anti-cancer activities of ZK002, a C-type lectin-like protein isolated from snake venom.

Abstract Snake venoms contain various biologically active proteins including C-type lectins and -like proteins (CTLs), phospholipases, proteinases and metalloproteinases, that could target diverse cellular processes. Among these active components, CTLs have demonstrated antithrombotic effects through their platelet agglutination and coagulation activities. In our study, we have detected anti-angiogenesis activity from the venom of Deinagkistrodon acutus snake. The partial purified fraction of snake venom with anti-angiogenesis activity was isolated through a stepwise separation in anion-exchange and cation-exchange chromatography. At the same time, the monoclonal antibody was generated and used for further protein purification by affinity chromatography. This highly purified protein was named as ZK002. By MALDI-TOF mass spectrometry determination, the mass of ZK002 is about 30KD. By LC-MS/MS analysis, protein sequence of highly purified ZK002 was determined and compared with the Deinagkistrodon acutus snake protein database. ZK002 is a heterodimer of CTLs consisting of alpha and beta peptide chains. Using In vitro chicken embryo chorioallantoic membrane assay and human umbilical vein endothelial cell (HUVEC) tube formation assay, it showed that ZK002 exhibited an anti-angiogenesis effect. Moreover, ZK002 also demonstrated an anti-cancer effect as shown in the ApcMin/+ mouse model for colorectal cancer. Administration of ZK002 significantly suppressed the total number and the size of tumors and showed no observable adverse effect. To further elucidate the anti-angiogenesis functions of ZK002, we deduced the coding DNA sequences from the peptide sequences of the alpha- and beta-chains, then subcloned individual gene sequence into yeast and mammalian expression vectors. Results showed that the recombinant vectors express secreted peptides with the expected molecular weight. Transient transfection of the alpha- and beta-recombinant vectors individually or in combination inhibit tube formation in HUVEC cells, suggesting that both alpha- and beta-chains possess anti-angiogenesis activity. The success of cloning and expression of recombinant ZK002 would greatly facilitate the future development of ZK002 as anti-angiogenesis and anti-cancer drugs. (This work is supported by the Innovation and Technology Fund (UIM208) of Hong Kong Government) Citation Format: Shan Yu, Xiangrong Dai, William C.S. Tai, Roy C.Y. Choi, Chaofan Liang, Benjamin X.y. Li, Karl W.K. Tsim, Wendy W.L. Hsiao. Anti-angiogenesis and anti-cancer activities of ZK002, a C-type lectin-like protein isolated from snake venom. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5077. doi:10.1158/1538-7445.AM2013-5077

Self-assembling amphipathic alpha-helical peptides induce the formation of active protein aggregates in vivo

We recently found that several self-assembling alpha, beta, or surfactant-like peptides, when terminally attached to proteins, can promote the in vivo assembly of active protein aggregates (or active inclusion bodies, AIBs) in Escherichia coil. In this work, we systematically examined the AIBs induced by an amphipathic alpha-helical peptide 18Awt (EWLKAFYEKVLEKLKELF) and its variants with altered ion pairs. Transmission electron microscopic and Fourier transform infrared spectroscopic analyses suggested that the AIBs appeared to adopt an amorphous mesh-like structure, and were likely induced by helical structures formed by the assembly of the 18A peptides. Confocal fluorescent micrographic analysis revealed that the AIBs resided around the periphery of the cell membrane or in the cytoplasm, depending on the distribution of ion pairs on the 18A peptides, which suggested that the association between the aggregates and the cell membrane was mediated by the lipid-18A interaction. Two of these 18A peptide variants were further used in constructing cleavable self-aggregating tags (cSAT) in conjunction with an intein molecule for protein purification, and verified using two model proteins. This extends the cSAT approach for laboratory and potentially industrial uses. Our study might also provide new insights into aggregation-related diseases.

Cytokine &amp; chemokine response in the lungs, pleural fluid and serum in thoracic surgery using one-lung ventilation

BackgroundThoracic surgery mandates usually a one-lung ventilation (OLV) strategy with the collapse of the operated lung and ventilation of the non-operated lung. These procedures trigger a substantial inflammatory response. The aim of this study was to analyze the cytokine and chemokine reaction in both lungs, pleural space and blood in patients undergoing lung resection with OLV with special interest in the chemokine growth-regulated peptide alpha (GROα) which is the human equivalent to the rat cytokine-induced neutrophil chemoattractant-1 (CINC-1).MethodsBroncho-alveolar lavage (BAL) fluid of both the collapsed, operated and the ventilated, non-operated lung, respectively, pleural space drainage fluid and blood was collected and the concentrations of interleukin (IL)-6, IL-1RA and GROα were determined with enzyme-linked immunosorbent assays in 15 patients.ResultsSubstantial inter-individual differences in the BAL fluid between patients in cytokine and chemokine levels occurred. In the pleural fluid and the blood these inter-individual differences were less pronounced. Both sides of the lung were affected and showed a significant increase in IL-6 and IL-1RA concentrations over time but not in GROα concentrations. Except for IL-6, which increased more in the collapsed, operated lung, no difference between the collapsed, operated and the ventilated, non-operated lung occurred. In the blood, IL-6 and IL-1RA increased early, already at the end of surgery. GROα was not detectable. In the pleural fluid, both cytokine and chemokine concentrations increased by day one. The increase was significantly higher in the pleural fluid compared to the blood.ConclusionThe inflammatory response of cytokines affects both the collapsed, operated and the ventilated, non-operated lungs. The difference in extent of response underlines the complexity of the inflammatory processes during OLV. In contrast to the cytokines, the chemokine GROα concentrations did not react in the BAL fluid or in the blood. This indicates that GROα might not be useful as marker for the inflammatory reaction in complex surgical procedures.

A Rabbit Vaginal Cell-Derived Antimicrobial Peptide, RVFHbαP, Blocks Lipopolysaccharide-Mediated Inflammation in Human Vaginal CellsIn Vitro

Antimicrobial peptides (AMPs) constitute a phylogenetically ancient form of innate immunity that provides host defense at various mucosal surfaces, including the vagina. Recently, we have identified one such AMP, rabbit vaginal fluid hemoglobin alpha peptide (RVFHbαP), from the vaginal lavage of rabbits (Oryctolagus cuniculus). The recent demonstration of a protective role of this peptide in erythrocytes and vaginal cells led us to investigate (i) the lipopolysaccharide (LPS) interactive domain in RVFHbαP and (ii) whether RVFHbαP of rabbit origin modulates the cellular immune responses of another species (humans) in vitro. HeLa-S3, a human vaginal epithelial cell line (hVEC), was exposed to LPS alone (10 μg/ml for 6 h), or LPS-induced cells were treated with RVFHbαP (70.45 μM for 1 h) and cultured for 24 h, and the results obtained were compared with the medium control. We show here that RVFHbαP exerts an anti-inflammatory activity in hVECs, as suggested by the prevention of LPS-induced production of extracellular (supernatant) and intracellular (lysate) levels of cytokines (interleukin 6 [IL-6] and IL-1α) and chemokines (IL-8 and monocyte chemoattractant protein 1 [MCP-1]). The demonstration of Toll-like receptor 4 (TLR4) and NF-κB expression in hVECs and the observations of RVFHbαP suppression of human β-defensin-1 (hBD1) mRNA expression further support the hypothesis of a genomic activity of RVFHbαP. Confocal microscopy and flow cytometry results demonstrate that RVFHbαP inhibits LPS-induced phagocytosis of Escherichia coli by macrophages. The chemotaxis studies performed using the Boyden chamber Transwell method showed the increased migration of U937 cells when supernatants of LPS-induced hVECs were used, and this effect was inhibited by RVFHbαP. In conclusion, our study proposes a novel explanation for the protective role of RVFHbαP in inflammation-associated infections, which not only may provide the new cellular targets for the screening of RVFHbαP ligands acting in the vaginal tissue but also has the potential to develop RVFHbαP as a therapeutic agent for reproductive tract infections.

Induction of Human β-defensins and Psoriasin in Vulvovaginal Human Papillomavirus–Associated Lesions

Infections with a low-risk type of human papillomavirus (HPV) may lead to genital warts. HPV targets the basal cell layer of epithelial cells. The first line of defense is the innate immune system, which provides nonspecific protection against a variety of pathogens. The antimicrobial peptides (AMPs) α- and β-defensins, cathelicidins, psoriasin, and RNase7 are central mediators. The expression of various α- and β-defensins, cathelicidin LL-37, psoriasin, and RNase7 was studied in biopsy samples from 35 patients with genital warts and 25 healthy women using quantitative real-time polymerase chain reaction and immunohistochemical analysis. We found a significantly higher expression of the β-defensins hBD-1 (P = .03), hBD-2 (P < 0.01), and hBD-3 (P < .001), and psoriasin (P = .001) in condylomata acuminata, compared with normal controls. The RNA and protein levels of RNase7 did not differ between infected and uninfected samples (P = .55). The α-defensins HNP 1-3, HD5, and HD6 and the cathelicidin LL-37 were scarcely detectable in normal and infected tissue. The differing expression of AMPs in HPV-infected, compared with noninfected, vulvovaginal biopsy samples suggests that these peptides are important in the local immune response. Curiously, hBD-1 shows a significant induction whereas RNase7 does not, which suggests differing regulation of AMPs over the course of bacterial and viral infections.

Alpha-melanocyte stimulating hormone plays an important role in the regulation of food intake by the central melanocortin system in chicks

Proopiomelanocortin (POMC, a precursor of melanocortin peptides) neurons in the hypothalamus play an important role in the central regulation of food intake in mammals. There is evidence that human melanocortin peptides alpha-, beta- and gamma2-melanocyte-stimulating hormone (α-, β- and γ2-MSH) significantly decreased food intake in chickens. However, the amino acid sequences of β- and γ2-MSH of chickens are different from those of humans whereas the amino acid sequence of α-MSH is conserved between these species. In the present study, we examined the effects of the central administration of α-, chicken β-, and chicken γ2-MSH on food intake in chicks. Central administration of α-MSH significantly suppressed food intake in chicks. In contrast, β- and γ2-MSH did not influence food intake in chicks. Central administration of HS014, a melanocortin 4 receptor antagonist, significantly reversed the anorexigenic action of α-MSH, suggesting that this action is mediated by the melanocortin 4 receptor in chicks as well as in mammals. These results suggest that α-MSH may play an important role in the regulation of food intake by the central melanocortin system in chicks.

Glutathionyl Hemoglobin Has Potential as a Biomarker of Iron Deficiency Anemia

AbstractAbstract 3210 Introduction:Iron deficiency anemia (IDA) is a major health problem worldwide. Although a clinical diagnosis is relatively simple, specific laboratory markers of IDA are lacking especially in the setting of inflammation. Ferritin, the current standard to define IDA is an acute phase protein that is non-specifically elevated during inflammation. Serum transferrin receptor level measurements although available are not yet standardized as a clinical tool. Serum hepcidin is a recently developed novel marker that is currently neither available nor standardized sufficiently. Furthermore, such assays require instrumentation, technical sophistication, and are expensive. Objectives:We sought to identify novel markers of IDA using mass spectrometry based proteomics. Identifying such markers could yield targets that once validated could serve cost effective point of care assays to detect iron deficiency anemia. Since there is evidence for oxidative damage mediated by reactive oxygen species in IDA, as a first step, we characterized and quantified posttranslational oxidative modifications of hemoglobin and tested their utility as biomarkers. Patients and Methods:We prospectively enrolled patients with IDA (defined as ferritin <12ng/ml in the presence of normal CRP and/or a bone marrow aspirate with “0” iron stores) and healthy controls (n = 23 and 15 respectively). Patients with diabetes, cardiovascular disease, renal disease, cerebrovascular disease and liver disease were excluded as these are conditions associated with preexisting oxidant stress. Erythrocytes from the blood of IDA patients and controls were isolated by centrifugation, washed in 0.9% saline, and lysed in distilled water to yield intracellular hemoglobin. Hemoglobin was then either studied further as an intact molecule or after digestion with trypsin. We used matrix assisted laser desorption ionization (MALDI - TOF) mass spectrometry to identify oxidative modifications of tryptic digested hemoglobin. We used electro spray ionization (ESI) mass spectrometry to identify and semiquantitate oxidative hemoglobin modifications by methods previously established and published by others and ourselves. Results:Using a combination of mass spectrometric methods, we identified 4 oxidative modifications of hemoglobin in patients with IDA and healthy controls (Table 1). Interestingly, a non enzymatic posttranslational modification of hemoglobin, glutathionyl hemoglobin, was found to be significantly increased in IDA patients compared with healthy controls (Glutathionyl hemoglobin % of beta chain; mean ± SD 0.169 ± 0.096 vs 0.077 ± 0.037; p = 0.001). Markers of oxidative stress (reduced RBC glutathione) were lower in IDA compared to healthy controls but the difference was not significant (mean ± SD 0.92 ± 0.53 vs 1.08 ± 0.52 mmol/L; p = 0.54). Glutathionyl hemoglobin levels correlated inversely with serum ferritin (Spearman rho -0.485; p < 0.05).Table 1Oxidative modifications of specific amino acid residues on tryptic digested peptides of alpha and beta chains of hemoglobin obtained from healthy controls and patients with iron deficiency anemia. AA, amino acidMALDI analysisAA modifiedControl(n = 15)IDA (n = 23)alpha chain 1071 oxidation to 1087Methionine15/1522/23alpha chain 1529 oxidation to 1545Tyrosine15/1517/23Beta chain 1274 oxidation to 1290Tryptophan15/1523/23Beta chain 2060 oxidation to 2076Methionine15/1523/23 Conclusions:Using two distinct proteomic methods, we identified oxidative posttranslational modifications of hemoglobin in IDA and healthy controls. Glutathionyl hemoglobin, an established marker of oxidative stress was elevated in patients with IDA and correlated inversely with serum ferritin. Overall, these findings suggest that glutathionyl hemoglobin has potential as a biomarker of IDA. Disclosures:No relevant conflicts of interest to declare.

Proteomic analysis of mitochondrial proteins in a mouse model of type 2 diabetes

Impaired mitochondrial function may contribute to the onset of contractile dysfunction with insulin resistance/type 2 diabetes. Our aim was therefore to determine alterations in the mitochondrial proteome of a mouse model of obesity/type 2 diabetes. Mitochondrial proteins were isolated from hearts collected from 18- to 20-week-old female db/db mice and compared to matched controls. We performed two-dimensional polyacrylamide gel electrophoresis to determine differentially expressed proteins. Peptides of interest were further analysed by mass spectrometry and Mascot software was employed to identify protein matches. Our data showed that ATP synthase D chain, ubiquinol cytochrome-C reductase core protein 1 and electron transfer flavoprotein subunit alpha peptide levels were altered with obesity. Moreover, we found coordinate downregulation of contractile proteins in the obese heart, i.e. α-smooth muscle actin, α-cardiac actin, myosin heavy-chain α and myosin-binding protein C. We propose that decreased contractile protein levels may contribute to contractile dysfunction of hearts from diabetic mice.

Tumor therapy in mice by using a tumor antigen linked to modulin peptides from Staphylococcus epidermidis

Staphylococcus epidermidis releases a complex of at least four peptides, termed phenol-soluble modulins (PSM), which stimulate macrophages to produce proinflammatory cytokines via activation of TLR2 signalling pathway. We demonstrated that covalent linkage of PSM peptides to an antigen facilitate its capture by dendritic cells and, in combination with different TLR ligands, can favour the in vivo induction of strong and persistent antigen-specific immune responses. Treatment of mice grafted with HPV16-E7-expressing tumor cells (TC-1) with poly(I:C) and a peptide containing αMod linked to the H-2Db-restricted cytotoxic T-cell epitope E7(49–57) from HPV16-E7 protein allowed complete tumor regression in 100% of the animals. Surprisingly, this immunomodulatory property of modulin-derived peptides was TLR2 independent and partially dependent upon the EGF-receptor signalling pathway. Our results suggest that alpha or gamma modulin peptides may serve as a suitable antigen carrier for the development of anti-tumoral or anti-viral vaccines.

Kynurenate Derivative Attenuates the Nitroglycerin‐Induced CamKIIα and CGRP Expression Changes

To examine the efficacy of L-kynurenine and a novel kynurenic acid derivative on the nitroglycerin-induced calmodulin-dependent protein kinase II alpha (CamKIIalpha) and calcitonin gene-related peptide (CGRP) expression changes in the rat caudal trigeminal nucleus. Systemic administration of the nitric oxide donor nitroglycerin can trigger an attack in migraineurs. In the rat, nitroglycerin activates second-order neurons in the caudal trigeminal nucleus, and increases expression of the CamKIIalpha and decreases that of the CGRP there. As glutamatergic mechanisms may be crucial in trigeminal pain processing, the aim of our study was to examine the effects of L-kynurenine, a metabolic precursor of the N-methyl D-aspartate receptor antagonist kynurenic acid, on the nitroglycerin-induced changes in CamKIIalpha and CGRP immunoreactivity. One hour before the nitroglycerin (10 mg/kg bodyweight, s.c.) injection, the animals were pretreated with L-kynurenine (300 mg/kg bodyweight, i.p.) or 2-(2-N,N-dimethylaminoethylamine-1-carbonyl)-1H-quinolin-4-one hydrochloride (300 mg/kg bodyweight, i.p.), a novel kynurenic acid derivative. Four hours later, the rats were perfused transcardially and the cervical spinal cord segments were removed for immunohistochemistry. Results.- L-kynurenine and 2-(2-N,N-dimethylaminoethylamine-1-carbonyl)-1H-quinolin-4-one hydrochloride pretreatment attenuated the nitroglycerin-induced changes in CamKIIalpha and CGRP immunoreactivity in the rat caudal trigeminal nucleus. These findings suggest a mechanism by which the inhibition of the excitatory amino acid receptors by kynurenic acid and its derivatives can alter trigeminal nociception.

Monitoring the large-scale production of the antihypertensive peptides RYLGY and AYFYPEL by HPLC-MS

This work reports the quantitative analysis of two novel antihypertensive peptides alpha(s1)-CN f(90-94), with sequence RYLGY, and alpha(s1)-CN f(143-149), with sequence AYFYPEL, by high-performance liquid chromatography-mass spectrometry in food-grade hydrolysates of milk proteins. The method was validated and showed sufficient specificity, reproducibility, linearity and recovery. Linear calibrations of the molecular ions m/z 671.2 and 902.3 were selected for the determination of the peptides RYLGY and AYFYPEL, respectively, and showed good statistical results (R(2) > or = 0.995 and with no significant lack-of-fit). The simplicity of RP-HPLC-MS method allowed the automated quantification of both antihypertensive peptides without any sample pretreatment. The application of this method permitted the evaluation of some hydrolysis variables, i.e., substrate, temperature, hydrolysis time or enzyme/substrate ratio, on the formation of antihypertensive peptides. The quantitative analysis of RYLGY and AYFYPEL showed that ultrafiltration was not effective to improve the content in active peptides, containing the hydrolysates and their respective permeates similar peptide amounts.

α1A-Adrenergic Receptor-Directed Autoimmunity Induces Left Ventricular Damage and Diastolic Dysfunction in Rats

BackgroundAgonistic autoantibodies to the α1-adrenergic receptor occur in nearly half of patients with refractory hypertension; however, their relevance is uncertain.Methods/Principal FindingsWe immunized Lewis rats with the second extracellular-loop peptides of the human α1A-adrenergic receptor and maintained them for one year. α1A-adrenergic antibodies (α1A-AR-AB) were monitored with a neonatal cardiomyocyte contraction assay by ELISA, and by ERK1/2 phosphorylation in human α1A-adrenergic receptor transfected Chinese hamster ovary cells. The rats were followed with radiotelemetric blood pressure measurements and echocardiography. At 12 months, the left ventricles of immunized rats had greater wall thickness than control rats. The fractional shortening and dp/dtmax demonstrated preserved systolic function. A decreased E/A ratio in immunized rats indicated a diastolic dysfunction. Invasive hemodynamics revealed increased left ventricular end-diastolic pressures and decreased dp/dtmin. Mean diameter of cardiomyocytes showed hypertrophy in immunized rats. Long-term blood pressure values and heart rates were not different. Genes encoding sarcomeric proteins, collagens, extracellular matrix proteins, calcium regulating proteins, and proteins of energy metabolism in immunized rat hearts were upregulated, compared to controls. Furthermore, fibrosis was present in immunized hearts, but not in control hearts. A subset of immunized and control rats was infused with angiotensin (Ang) II. The stressor raised blood pressure to a greater degree and led to more cardiac fibrosis in immunized, than in control rats.Conclusions/SignificanceWe show that α1A-AR-AB cause diastolic dysfunction independent of hypertension, and can increase the sensitivity to Ang II. We suggest that α1A-AR-AB could contribute to cardiovascular endorgan damage.

Site‐specific inhibition of integrin αvβ3‐vitronectin association by a ser‐asp‐val sequence through an Arg‐Gly‐Asp‐binding site of the integrin

A functional proteomic technology using protein chip and molecular simulation was used to demonstrate a novel biomolecular interaction between P11, a peptide containing the Ser-Asp-Val (SDV) sequence and integrin alpha v beta 3. P11 (HSDVHK) is a novel antagonistic peptide of integrin alpha v beta 3 screened from hexapeptide library through protein chip system. An in silico docking study and competitive protein chip assay revealed that the SDV sequence of P11 is able to create a stable inhibitory complex onto the vitronectin-binding site of integrin alpha v beta 3. The Arg-Gly-Asp (RGD)-binding site recognition by P11 was site specific because the P11 was inactive for the complex formation of a denatured form of integrin-vitronectin. P11 showed a strong antagonism against alpha v beta 3-GRGDSP interaction with an IC(50) value of 25.72+/-3.34 nM, whereas the value of GRGDSP peptide was 1968.73+/-444.32 nM. The binding-free energies calculated from the docking simulations for each P11 and RGD peptide were -3.99 and -3.10 kcal/mol, respectively. The free energy difference between P11 and RGD corresponds to approximately a 4.5-fold lower K(i) value for the P11 than the RGD peptide. The binding orientation of the docked P11 was similar to the crystal structure of the RGD in alpha v beta 3. The analyzed docked poses suggest that a divalent metal-ion coordination was a common driving force for the formation of both SDV/alpha v beta 3 and RGD/alpha v beta 3 complexes. This is the first report on the specific recognition of the RGD-binding site of alpha v beta 3 by a non-RGD containing peptide using a computer-assisted proteomic approach.

Serum interleukin-6 and C-reactive protein are markedly elevated in acute decompensated heart failure patients with left ventricular systolic dysfunction

Cytokines play important roles in heart failure (HF). We examined whether cytokine levels are different in acute decompensated heart failure (ADHF) patients between with left ventricular systolic dysfunction (LVSDF) and with preserved LV ejection function (PLVEF). We studied 81 HF patients who were admitted to our hospital with acute decompensation. They were divided into two groups: LVSDF (LVEF)<45% and PLVEF (LVEF45%). Serum interleukin-6 (IL-6), highly sensitive C-reactive protein (hsCRP), tumor necrosis factor alpha (TNF-alpha), and IL-18 and plasma brain natriuretic peptide (BNP) were measured on admission and at discharge. On admission, IL-6 and hsCRP were higher in LVSDF than in PLVEF. IL-6 and hsCRP decreased after treatment in LVSDF, but not in PLVEF, while plasma BNP levels decreased in both HF with treatment. There was no difference in TNF-alpha or in IL-18 level between LVSDF and PLVEF, and they did not change after treatment in either group. In conclusion, cytokine profiles were different in ADHF between those with LVSDF and PLVEF. Activation of IL-6-hsCRP pathway may play a specific role in ADHF with LVSDF.

Emotional stress and orthodontic tooth movement: effects on apical root resorption, tooth movement, and dental tissue expression of interleukin-1 alpha and calcitonin gene-related peptide immunoreactive nerve fibres in rats

The aim of the study was to investigate the effect of emotional stress on apical root resorption (ARR) and tooth displacement during orthodontic tooth movement in rats. A further area of interest was to evaluate if the expression of interleukin-1 alpha (IL-1alpha) as well as the density and distribution of peptidergic nerve fibres immunoreactive to calcitonin gene-related peptide (CGRP) in the periodontal ligament (PDL) are associated with possible stress-induced changes in root resorption and tooth movement. A total of 52 male Wistar rats, aged 6 weeks, were divided in three experimental and one control group (n = 4). Group 1 had orthodontic tooth movement and received foot shocks (OTMS; n = 16), group 2 had orthodontic tooth movement but received no foot shocks (OTMNS; n = 16), and group 3 had no orthodontic tooth movement and received foot shocks (NOTMS; n = 16). Each group was further divided into four subgroups (n = 4), corresponding to the period of the experiment, i.e. 3, 7, 13, and 21 days. At the end of each experimental period, the blood samples were taken, the animals were sacrificed, and the jaws excised, deminerialized, and processed for immunocytochemistry. One-way analysis of variance was used to detect inter-group differences for all investigated variables. CGRP immunopositive nerve fibres were evaluated qualitatively. All the experimental groups demonstrated higher corticosterone levels than the control group, suggesting a stress-induced experience by orthodontic treatment per se. The OTMS group had the least amount of cellular cementum throughout the experimental periods and showed significant reduction in tooth displacement, especially at 3 and 7 days. No obvious changes were observed in the dental tissue expression of IL-1alpha and CGRP immunoreactive nerve fibres between the stressed and non-stressed orthodontically treated groups.

Effect of reaction conditions and 3AB on the mutation rate of poliovirus RNA-dependent RNA polymerase in a α-complementation assay

The fidelity of poliovirus RNA-dependent RNA polymerase (3Dpol) was determined using a modified α-complementation assay. Several polymerases have been analyzed by this approach allowing comparisons to be drawn. Various conditions including high and low MgCl 2, replacing MgCl 2 with MnCl 2, skewed nucleotide pools, and the presence of poliovirus protein 3AB were analyzed. The assay included RNA synthesis by 3Dpol on an RNA template that coded for a region of the alpha peptide of β-galactosidase (lacZ-α). The product of this reaction was used as a template for a second round of 3Dpol synthesis and the resulting RNA was reverse transcribed to DNA by reverse transcriptase. The DNA was amplified by PCR and inserted into a vector used to transform Escherichia coli. The bacteria were screened for β-galactosidase activity by blue–white phenotype analysis with white or faint blue colonies scored as errors made during synthesis on lacZ-α. Although 3AB strongly stimulated 3Dpol synthesis as expected, no change in fidelity was detected. Changes in MgCl 2 also showed little effect. Mutation rates of ∼9 × 10 −5 (∼1 error per 11,000 incorporations) were estimated for these conditions. In contrast, MnCl 2 or skewed nucleotide pools were highly mutagenic resulting in lowered fidelity.

Calcitonin gene-related peptide alpha (CALCA) gene haplotypes and circulating CGRP levels significantly associate with risk of essential hypertension in Chinese subjects

Calcitonin gene-related peptide alpha (CALCA) gene haplotypes and circulating CGRP levels significantly associate with risk of essential hypertension in Chinese subjects

Convergence and Heterogeneity in Peptide Folding with Replica Exchange Molecular Dynamics.

Replica exchange molecular dynamics (REMD) techniques have emerged as standard tools for simulating peptides and small proteins, in part, to evaluate the accuracy of modern classical force fields for polypeptides. However, it often remains a challenge to unambiguously discriminate force field flaws from simulations that do not reach equilibrium convergence. Here, we examine closely the convergence behavior of REMD runs for 14 test alpha and beta peptide systems, using an AMBER force field with a generalized Born/surface area implicit solvation model. Somewhat surprisingly, we find that convergence times can be quite large compared to the time scales reached in many earlier REMD efforts, with some short peptides requiring up to 60 ns of run time (per replica). Moreover, we detect a high degree of run-to-run heterogeneity, finding that REMD runs of the same peptide seeded with different initial velocities can exhibit a range of fast- and slow-folding behavior. By increasing the number of swap attempts per REMD cycle, we are able to reduce heterogeneity by diminishing the presence of slower-folding trajectories. Finally, we notice that convergence often can be signaled by a spike in the population of the most populated configurational cluster - a metric that is independent of the native structure. These results suggest that the systematic application of long runs, multiple trials, and convergence indicators may be important in future folding studies and in force field development efforts.