Polypeptide Levels Research Articles

High Throughput Screening Based Highly Potent Sulfonylbenzamide Anti-diabetic Drug

Background: Dipeptidyl peptidase-4 (DPP4), a serine exopeptidase which is found in human, is encoded by the DPP4 gene. Glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP) levels increase in the presence of DPP-4 inhibitors, which also inhibit the release of glucagon. Accordingly, insulin secretion increases with gastric emptying and blood glucose levels decrease. Objective: The aim of the present work was to screen suitable DPP4 inhibitors which can be used to treat diabetes mellitus type 2. Method: 230 sulfonyl-benzamides have been screened by Discovery Studio Molecular Docking Programme to search the best suitable molecule for type 2 diabetes treatment. To find inhibitors with high stability and flexibility, molecular dynamics (MD) simulation has been done and Lipinski’s rule of five protocols has been employed to screen druglikeness. ADMET (absorption, distribution, metabolism, excretion and toxicity) filtration has also been used to value the toxicity. Among them, 106 sulfonyl-benzamide showed better docking score than the approved diabetes mellitus type 2 drug. These sulfonylbenzamides also passed the ADMET and druglikeness filters. Quantitative structure– activity relationship has been studied to observe change in the docking properties with the change of druglike sulfonyl-benzamide molecules. DFT computation of optimized geometry and derivation of molecular orbitals have been used to correlate the druglikeness. The small difference in the energy between HOMO and LUMO may help to activate the drug in the protein environment quickly. Pharmacophore generation has been done to recognize the inhibitors binding modes in the active site of receptor. Results: 4-chloro-N-[3-[[(1S)-1-(4-methylsulfonylphenyl)ethyl]amino]-3-oxopropyl]benzamide (MSPB) showed the best theoretical efficiency as DPP-4 inhibitor. Conclusion: Structure based drug design approach for the treatment of type-2 diabetes revealed its influence on the development of new DPP-4 sulfonyl-benzamide inhibitors. Keywords: Sulfonyl-benzamide, type-2 diabetes DPP-4 inhibitors, structure based drug design, molecular docking and MD simulation, ADMET, pharmacophore generation.

Biomarkers for Acute Brain Injury in Cord Blood [23E

INTRODUCTION: We investigated whether the second stage of labor (mode and duration) is associated with differences in biomarkers of neuronal injury in cord blood. METHODS: Using a prospective, longitudinal biobank of cord blood specimens, all women who underwent a forceps or vacuum delivery were matched to 3 controls: (1) an unlabored cesarean, (2) the shortest second stage within 3 months and (3) the longest second stage within 3 months. Cord blood samples were analyzed for two established biomarkers of acute axonal injury: total TAU and neurofilament light polypeptide (NFL). RESULTS: Our cohort consisted of 56 women. Maternal comorbidities and labor complications were similar across groups. Median levels of NFL, but not TAU, were statistically different across the 4 groups (forceps/vacuum 19.8 vs. unlabored cesarean 11.0 vs. short second stage 15.4 vs. long second stage 21.1; p<0.01). The most marked differences were by second stage duration irrespective of mode. Those with a second stages >2 hours (N=19) had a median NFL level more than twice that of those with an unlabored cesarean (22.7 vs. 11.0; p<0.01). CONCLUSION: Neurofilament light polypeptide levels (NFL) are significantly greater in cord blood after a prolonged second stage. While there is no current data to suggest this is associated with long term neurologic morbidity, the robust association of NFL with neuroaxonal injury in adults may prompt further research. Using biomarkers of acute brain injury may help obstetricians further clarify safety of varying second stage durations and/or help neonatologists better predict which neonates may benefit from interventions, such as therapeutic hypothermia.

Postprandial glucose-lowering effect of premeal consumption of protein-enriched, dietary fiber-fortified bar in individuals with type 2 diabetes mellitus or normal glucose tolerance.

Aims/IntroductionProtein preload improves postprandial glycemia by stimulating secretion of insulin and incretin hormones. However, it requires a large dose of protein to produce a significant effect. The present study was carried out to investigate the postprandial glucose‐lowering effect of a premeal protein‐enriched, dietary fiber‐fortified bar (PFB), which contains moderate amounts of protein, in individuals with type 2 diabetes mellitus or normal glucose tolerance (NGT).Materials and MethodsThe participants (15 type 2 diabetes mellitus and 15 NGT) were randomly assigned to either a premeal or postmeal PFB group and underwent two mixed meal tolerance tests, 1 week apart in reverse order. Plasma levels of glucose, insulin, glucagon‐like peptide‐1 and glucose‐dependent insulinotropic polypeptide were measured.ResultsDuring the mixed meal tolerance tests, the incremental area under the curve from 0 to 180 min of plasma glucose levels was lower with premeal PFB than with postmeal PFB in the type 2 diabetes mellitus (14,723 ± 1,310 mg min/dL vs 19,642 ± 1,367 mg min/dL; P = 0.0002) and NGT participants (3,943 ± 416 mg min/dL vs 4,827 ± 520 mg min/dL, P = 0.0296). In the type 2 diabetes mellitus participants, insulinogenic index and the incremental area under the curve from 0 to 180 min of plasma total glucagon‐like peptide‐1 levels were higher with premeal PFB than with postmeal PFB, but not in the NGT participants. There was no difference in postprandial glucose‐dependent insulinotropic polypeptide levels between premeal and postmeal PFB in both groups.ConclusionsAcute administration of premeal PFB decreased postprandial glucose excursion in both type 2 diabetes mellitus and NGT participants. In the type 2 diabetes mellitus participants, premeal PFB augmented the early‐phase insulin secretion, possibly through enhancing glucagon‐like peptide‐1 secretion.

CD36 Modulates Fasting and Preabsorptive Hormone and Bile Acid Levels.

Abnormal fatty acid (FA) metabolism contributes to diabetes and cardiovascular disease. The FA receptor CD36 has been linked to risk of metabolic syndrome. In rodents CD36 regulates various aspects of fat metabolism, but whether it has similar actions in humans is unknown. We examined the impact of a coding single-nucleotide polymorphism in CD36 on postprandial hormone and bile acid (BA) responses. To examine whether the minor allele (G) of coding CD36 variant rs3211938 (G/T), which reduces CD36 level by ∼50%, influences hormonal responses to a high-fat meal (HFM). Obese African American (AA) women carriers of the G allele of rs3211938 (G/T) and weight-matched noncarriers (T/T) were studied before and after a HFM. Two-center study. Obese AA women. HFM. Early preabsorptive responses (10 minutes) and extended excursions in plasma hormones [C-peptide, insulin, incretins, ghrelin fibroblast growth factor (FGF)19, FGF21], BAs, and serum lipoproteins (chylomicrons, very-low-density lipoprotein) were determined. At fasting, G-allele carriers had significantly reduced cholesterol and glycodeoxycholic acid and consistent but nonsignificant reductions of serum lipoproteins. Levels of GLP-1 and pancreatic polypeptide (PP) were reduced 60% to 70% and those of total BAs were 1.8-fold higher. After the meal, G-allele carriers displayed attenuated early (-10 to 10 minute) responses in insulin, C-peptide, GLP-1, gastric inhibitory peptide, and PP. BAs exhibited divergent trends in G allele carriers vs noncarriers concomitant with differential FGF19 responses. CD36 plays an important role in the preabsorptive hormone and BA responses that coordinate brain and gut regulation of energy metabolism.

Effect of gastric bypass combined with ileal transportation on type 2 diabetes mellitus.

Type 2 diabetes mellitus (T2DM) is a chronic progressive disease, which manifests as an endocrine disorder. Among the different methods of surgery available to treat patients with T2DM, Roux-en-Y gastric bypass (RYGBP) and ileal transposition (IT) are the most commonly performed. The aim of the present study was to investigate the effects of RYGBP combined with IT on rats with T2DM. A total of 8 healthy male rats were used as a control group and 40 GK rats were randomly divided into 5 groups: A diabetes mellitus (DM) group, a sham operative group (SO), a RYGBP group, an IT group and a RYGBP+IT group. The results demonstrated that fasting blood glucose, triglyceride, total cholesterol and gastric inhibitory polypeptide levels in all treatment groups were significantly lower than those of the SO and DM groups. Furthermore, levels TC and TG in the RYGBP+IT group were significantly lower than in the RYGBP and IT groups. Levels of phosphoenolpyruvate carboxykinase and glucose-6-phosphatase mRNA and IRS-2 protein in all treatment groups were also significantly lower than those of the SO group; and they were significantly lower in the RYGBP+IT group compared with the RYGBP and IT groups. The expression of phosphorylated Akt in the treatment groups was significantly higher than the SO group and was significantly higher in the RYGBP+IT group compared with the RYGBP and IT groups. These results indicate that RYGBP and IT surgical treatment can induce T2DM remission by mediating the expression of insulin-related factors to reverse insulin resistance. The current study also indicated that the effect of RYGBP combined with IT may be developed as a novel first-line method of treating T2DM.

Cholinergic signaling mediates the effects of xenin-25 on secretion of pancreatic polypeptide but not insulin or glucagon in humans with impaired glucose tolerance.

We previously demonstrated that infusion of an intestinal peptide called xenin-25 (Xen) amplifies the effects of glucose-dependent insulinotropic polypeptide (GIP) on insulin secretion rates (ISRs) and plasma glucagon levels in humans. However, these effects of Xen, but not GIP, were blunted in humans with type 2 diabetes. Thus, Xen rather than GIP signaling to islets fails early during development of type 2 diabetes. The current crossover study determines if cholinergic signaling relays the effects of Xen on insulin and glucagon release in humans as in mice. Fasted subjects with impaired glucose tolerance were studied. On eight separate occasions, each person underwent a single graded glucose infusion- two each with infusion of albumin, Xen, GIP, and GIP plus Xen. Each infusate was administered ± atropine. Heart rate and plasma glucose, insulin, C-peptide, glucagon, and pancreatic polypeptide (PP) levels were measured. ISRs were calculated from C-peptide levels. All peptides profoundly increased PP responses. From 0 to 40 min, peptide(s) infusions had little effect on plasma glucose concentrations. However, GIP, but not Xen, rapidly and transiently increased ISRs and glucagon levels. Both responses were further amplified when Xen was co-administered with GIP. From 40 to 240 min, glucose levels and ISRs continually increased while glucagon concentrations declined, regardless of infusate. Atropine increased resting heart rate and blocked all PP responses but did not affect ISRs or plasma glucagon levels during any of the peptide infusions. Thus, cholinergic signaling mediates the effects of Xen on insulin and glucagon release in mice but not humans.

Profile of Gut Hormones, Pancreatic Hormones and Pro-inflammatory Cytokines in New Zealand Maori.

BackgroundMaori, indigenous people of New Zealand, have at least two times higher prevalence of obesity and diabetes in comparison with the general population in the country. Gut and pancreatic hormone profile differences as well as pro-inflammatory milieu may contribute to this disparity. The aim was to investigate the differences in gut hormones, pancreatic hormones and pro-inflammatory cytokines between Maori and non-Maori individuals.MethodsThis was a cross-sectional study. Fasting blood samples were collected to measure cholecystokinin, ghrelin, gastric inhibitory peptide, glicentin, glucagon-like peptide-1 and -2, oxyntomodulin, secretin, amylin, C-peptide, glucagon, insulin, pancreatic polypeptide, somatostatin, interleukin-6, monocyte chemoattractant protein-1 and tumour necrosis factor-α. Binary logistic regression analysis was conducted in one unadjusted and four adjusted statistical models adjusting for patient-, metabolic- and pancreatitis-related factors.ResultsA total of 8 Maori and 85 non-Maori individuals were included. Circulating levels of ghrelin, pancreatic polypeptide and interleukin-6 levels were significantly higher in Maori (P = 0.005, P = 0.003 and P = 0.011, respectively) in both unadjusted and all the four adjusted analyses. Other signaling molecules did not show consistently significant associations with ethnicity.ConclusionProfile of gut hormones, pancreatic hormones and pro-inflammatory cytokines appears to differ between Maori and non-Maori individuals, independent of obesity, diabetes and other covariates. This may go some way to explain the increased propensity to obesity and diabetes in the Maori population.

PPARγ Modulates Long Chain Fatty Acid Processing in the Intestinal Epithelium.

Nuclear receptor PPARγ affects lipid metabolism in several tissues, but its role in intestinal lipid metabolism has not been explored. As alterations have been observed in the plasma lipid profile of ad libitum fed intestinal epithelium-specific PPARγ knockout mice (iePPARγKO), we submitted these mice to lipid gavage challenges. Within hours after gavage with long chain unsaturated fatty acid (FA)-rich canola oil, the iePPARγKO mice had higher plasma free FA levels and lower gastric inhibitory polypeptide levels than their wild-type (WT) littermates, and altered expression of incretin genes and lipid metabolism-associated genes in the intestinal epithelium. Gavage with the medium chain saturated FA-rich coconut oil did not result in differences between the two genotypes. Furthermore, the iePPARγKO mice did not exhibit defective lipid uptake and stomach emptying; however, their intestinal transit was more rapid than in WT mice. When fed a canola oil-rich diet for 4.5 months, iePPARγKO mice had higher body lean mass than the WT mice. We conclude that intestinal epithelium PPARγ is activated preferentially by long chain unsaturated FAs compared to medium chain saturated FAs. Furthermore, we hypothesize that the iePPARγKO phenotype originates from altered lipid metabolism and release in epithelial cells, as well as changes in intestinal motility.

Prognostic Utility of Total 68Ga-DOTATATE-Avid Tumor Volume in Patients With Neuroendocrine Tumors

Survival times vary among patients with neuroendocrine tumors (NETs) - even among those with the same site, stage, and grade of primary tumor. This makes it difficult to select treatment for patients with unresectable NETs because some patients can survive decades without treatment. 68Gallium-DOTATATE positron emission tomography with computed tomography (68Ga-DOTATATE PET/CT) is a sensitive imaging technique for detection of NETs. We investigated the prognostic accuracy of 68Ga-DOTATATE PET/CT-based analysis of tumor volume in patients with NETs. We performed a prospective study of 184 patients with NETs (128 [69.6%] with metastases and 11 patients [6.0%] with locally advanced disease) at the National Institutes of Health Clinical Center (Bethesda, MD) from 2013 through 2017. All patients underwent 68Ga-DOTATATE PET/CT image analysis and total 68Ga-DOTATATE-Avid tumor volume (68Ga-DOTATATE TV) was determined. We also measured fasting serum chromogranin A, neuron-specific enolase, gastrin, glucagon, vasoactive intestinal peptide, pancreatic polypeptide, and 24-hour urinary 5-hydroxyindoleacetic acid levels in all patients. Disease progression was defined as a new lesion or a growth of a known lesion during the interval between baseline 68Ga-DOTATATE PET/CT scan and follow-up imaging (14.0 ± 6.1 months; range, 1-35 months). The primary outcomes were progression-free survival (PFS) and disease-specific mortality during a median follow-up time of 18 months (range, 4-35 months). We found an inverse correlation between quartiles of 68Ga-DOTATATE TV and PFS (P= .001) and disease-specific survival (P= .002). A 68Ga-DOTATATE TV of 7.0 mL or more was associated with higher odds of disease progression (hazard ratio, 3.0; P= .04). A 68Ga-DOTATATE TV of 35.8 mL or more was associated with increased risk of disease-specific death (hazard ratio, 10.6) in multivariable analysis (P= .01), as well as in subgroup analysis of patients with pancreatic NETs. In a prospective study, we demonstrated the prognostic utility of 68Ga-DOTATATE TV in a large cohort of patients with NETs, in terms of PFS and disease-specific mortality.

Preserving Duodenal-Jejunal (Foregut) Transit Does Not Impair Glucose Tolerance and Diabetes Remission Following Gastric Bypass in Type 2 Diabetes Sprague-Dawley Rat Model.

Possible mechanisms underlying diabetes remission following Roux-en-Y gastric bypass (RYGB) include eradication of putative factor(s) with duodenal-jejunal bypass. The objective of this study is to observe the effects of duodenal-jejunal transit on glucose tolerance and diabetes remission in gastric bypass rat model. In order to verify the effect of duodenal-jejunal transit on glucose tolerance and diabetes remission in gastric bypass, 22 type 2 diabetes Sprague-Dawley rat models established through high-fat diet and low-dose streptozotocin (STZ) administered intraperitoneally were assigned to one of three groups: gastric bypass with duodenal-jejunal transit (GB-DJT n=8), gastric bypass without duodenal-jejunal transit (RYGB n=8), and sham (n=6). Body weight, food intake, blood glucose, as well as meal-stimulated insulin, and incretin hormone responses were assessed to ascertain the effect of surgery in all groups. Oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) were conducted three and 7weeks after surgery. Comparing our GB-DJT to the RYGB group, we saw no differences in the mean decline in body weight, food intake, and blood glucose 8weeks after surgery. GB-DJT group exhibited immediate and sustained glucose control throughout the study. Glucagon-like peptide 1 (GLP-1) and gastric inhibitory polypeptide (GIP) levels were also significantly increased from preoperative level in the GB-DJT group (p<0.05). Insulin and GLP-1 area under curve (AUC) as well as improved glycemic excursion on OGTT did not differ between GB-DJT and RYGB groups. Outcomes with sham operation did not differ from preoperative level. Preserving duodenal-jejunal transit does not impede glucose tolerance and diabetes remission after gastric bypass in type-2 diabetes Sprague-Dawley rat model.

Postmeal increment in intact glucagon-like peptide 1 level, but not intact glucose-dependent insulinotropic polypeptide levels, is inversely associated with metabolic syndrome in patients with type 2 diabetes

ABSTRACT Purpose: Metabolic syndrome increases the risk of cardiovascular disease. Recently glucagon-like peptide 1 (GLP-1) agonists proved to be effective in preventing cardiovascular disease (CVD) in patients with type 2 diabetes. We investigated the association of blood incretin levels with metabolic syndrome in patients with type 2 diabetes. Materials and methods: This is a cross-sectional study involving 334 people with type 2 diabetes. Intact GLP-1 (iGLP-1) and intact glucose-dependent insulinotropic polypeptide (iGIP) levels were measured in a fasted state and 30 min after ingestion of a standard mixed meal. Metabolic syndrome was diagnosed based on the criteria of the International Diabetes Federation. Results: Two hundred twenty-five (69%) of the subjects have metabolic syndrome. The fasting iGLP-1 level was no different between groups. Thirty-min postprandial iGLP-1 was non-significantly lower in the subjects who had metabolic syndrome. Incremental iGLP-1 (ΔiGLP-1, the difference between 30-min postmeal and fasting iGLP-1 levels) was significantly lower in those with metabolic syndrome. There were no significant differences in fasting iGIP, postprandial iGIP, and ΔiGIP between groups. The ΔiGLP-1, but not ΔiGIP levels decreased significantly as the number of metabolic syndrome components increased. In hierarchical logistic regression analysis, the ΔiGLP-1 level was found to be a significant contributor to metabolic syndrome even after adjusting for other covariates. Conclusion: Taken together, the iGLP-1 increment in the 30 min after meal ingestion is inversely associated with metabolic syndrome in patients with type 2 diabetes. This suggests that postmeal iGLP-1 increment could be useful in assessing cardiovascular risk in type 2 diabetes.

Heterozygous RFX6 protein truncating variants are associated with MODY with reduced penetrance

Finding new causes of monogenic diabetes helps understand glycaemic regulation in humans. To find novel genetic causes of maturity-onset diabetes of the young (MODY), we sequenced MODY cases with unknown aetiology and compared variant frequencies to large public databases. From 36 European patients, we identify two probands with novel RFX6 heterozygous nonsense variants. RFX6 protein truncating variants are enriched in the MODY discovery cohort compared to the European control population within ExAC (odds ratio = 131, P = 1 × 10−4). We find similar results in non-Finnish European (n = 348, odds ratio = 43, P = 5 × 10−5) and Finnish (n = 80, odds ratio = 22, P = 1 × 10−6) replication cohorts. RFX6 heterozygotes have reduced penetrance of diabetes compared to common HNF1A and HNF4A-MODY mutations (27, 70 and 55% at 25 years of age, respectively). The hyperglycaemia results from beta-cell dysfunction and is associated with lower fasting and stimulated gastric inhibitory polypeptide (GIP) levels. Our study demonstrates that heterozygous RFX6 protein truncating variants are associated with MODY with reduced penetrance.

Association of TCM body constitution with insulin resistance and risk of diabetes in impaired glucose regulation patients

BackgroundImpaired glucose regulation (IGR) patients have increased risk of type 2 diabetes mellitus (T2DM). Identifying relevant risk factors in IGR subjects could facilitate early detection and prevention of IGR progression to diabetes. This study investigated the association between Traditional Chinese Medicine (TCM) body constitution and serum cytokines, and whether body constitution could independently predict diabetes in IGR subjects.MethodPatients with IGR (n = 306) received a blood test and their body constitution type was assessed using a body constitution questionnaire (BCQ). Serum levels of cytokines were measured by ELISA. Patients were followed up for at least three years, and their status of diabetes were recorded. Multivariate logistic regression was used to estimate odds ratios (ORs) of diabetes for body constitution.ResultsPhlegm-damp, Damp-heat and Qi-deficiency were three most common unbanlenced constitutions among IGR subjects. Phlegm-damp and Damp-heat constitution subjects showed higher serum levels of interleukin 6 (IL-6), tumour necrosis factor-α (TNF-α), leptin and lower serum levels of adiponectin (P<0.05). Qi-deficiency constitution subjects showed higher serum levels of leptin and lower serum levels of adiponectin, glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP) (P<0.05). Subjects with Phlegm-damp or Damp-heat constitution demonstrated a significantly higher risk of diabetes (P<0.05).ConclusionPhlegm-damp and Damp-heat TCM body constitution are strongly associated with abnormal serum cytokines, and could potentially serve as a predictor of diabetes in IGR subjects. Body constitution can help to identify IGR subjects who are at a high risk of progression to diabetes.

Long-Term Dietary Supplementation with Yerba Mate Ameliorates Diet-Induced Obesity and Metabolic Disorders in Mice by Regulating Energy Expenditure and Lipid Metabolism.

This study evaluated whether long-term supplementation with dietary yerba mate has beneficial effects on adiposity and its related metabolic dysfunctions in diet-induced obese mice. C57BL/6J mice were randomly divided into two groups and fed their respective experimental diets for 16 weeks as follows: (1) control group fed with high-fat diet (HFD) and (2) mate group fed with HFD plus yerba mate. Dietary yerba mate increased energy expenditure and thermogenic gene mRNA expression in white adipose tissue (WAT) and decreased fatty acid synthase (FAS) mRNA expression in WAT, which may be linked to observed decreases in body weight, WAT weight, epididymal adipocyte size, and plasma leptin level. Yerba mate also decreased levels of plasma lipids (free fatty acids, triglycerides, and total cholesterol) and liver aminotransferase enzymes, as well as the accumulation of hepatic lipid droplets and lipid content by inhibiting the activities of hepatic lipogenic enzymes, such as FAS and phosphatidate phosphohydrolase, and increasing fecal lipid excretion. Moreover, yerba mate decreased the levels of plasma insulin as well as the homeostasis model assessment of insulin resistance, and improved glucose tolerance. Circulating levels of gastric inhibitory polypeptide and resistin were also decreased in the mate group. These findings suggest that long-term supplementation of dietary yerba mate may be beneficial for improving diet-induced adiposity, insulin resistance, dyslipidemia, and hepatic steatosis.

Changes in Expression of Neuropeptides and Their Receptors in the Hypothalamus and Gastrointestinal Tract of Calorie Restricted Hens

The list of orexigenic and anorexigenic peptides, those are known to alter feed intake, is continuously growing. However, most of them are studied in mammalian species. We aimed to investigate plasma level and mRNA expression of the pituitary adenylate cyclase-activating polypeptide (PACAP), gene expression of its receptor (PAC1), furthermore the gene expression of galanin (GAL), neuromedin U (NMU), and its two receptors (NMUR1 and NMUR2) in the hypothalamus, proventriculus, and jejunum of hens exposed to 40% calorie restriction. Feed restriction resulted in a 88% increase in mRNA and a 27% increase in peptide level of PACAP in proventriculus measured with qPCR and RIA, respectively. Increases were found in the gene expression of PAC1 (49%) and NMUR1 (63%) in the hypothalamus. Higher expressions of peptide encoding genes (76% for PACAP, 41% for NMU, 301% for NMUR1 and 308% for GAL, P < 0.05) were recorded in the jejunum of hens exposed to restricted nutrition. The results indicate that PACAP level responds to calorie restriction in the proventriculus and jejunum, but not in the hypothalamus and plasma.

Histone Deacetylase 2 Is a Component of Influenza A Virus-Induced Host Antiviral Response.

Host cells produce variety of antiviral factors that create an antiviral state and target various stages of influenza A virus (IAV) life cycle to inhibit infection. However, IAV has evolved various strategies to antagonize those antiviral factors. Recently, we reported that a member of class I host histone deacetylases (HDACs), HDAC1 possesses an anti-IAV function. Herein, we provide evidence that HDAC2, another class I member and closely related to HDAC1 in structure and function, also possesses anti-IAV properties. In turn, IAV, like HDAC1, dysregulates HDAC2, mainly at the polypeptide level through proteasomal degradation to potentially minimize its antiviral effect. We found that IAV downregulated the HDAC2 polypeptide level in A549 cells in an H1N1 strain-independent manner by up to 47%, which was recovered to almost 100% level in the presence of proteasome-inhibitor MG132. A further knockdown in HDAC2 expression by up to 90% via RNA interference augmented the growth kinetics of IAV in A549 cells by more than four-fold after 24 h of infection. Furthermore, the knockdown of HDAC2 expression decreased the IAV-induced phosphorylation of the transcription factor, Signal Transducer and Activator of Transcription I (STAT1) and the expression of interferon-stimulated gene, viperin in infected cells by 41 and 53%, respectively. The role of HDAC2 in viperin expression was analogous to that of HDAC1, but it was not in the phosphorylation of STAT1. This indicated that, like HDAC1, HDAC2 is a component of IAV-induced host innate antiviral response and performs both redundant and non-redundant functions vis-a-vis HDAC1; however, IAV dysregulates them both in a redundant manner.

Human COQ9 Rescues a coq9 Yeast Mutant by Enhancing Coenzyme Q Biosynthesis from 4-Hydroxybenzoic Acid and Stabilizing the CoQ-Synthome.

Coq9 is required for the stability of a mitochondrial multi-subunit complex, termed the CoQ-synthome, and the deamination step of Q intermediates that derive from para-aminobenzoic acid (pABA) in yeast. In human, mutations in the COQ9 gene cause neonatal-onset primary Q10 deficiency. In this study, we determined whether expression of human COQ9 could complement yeast coq9 point or null mutants. We found that expression of human COQ9 rescues the growth of the temperature-sensitive yeast mutant, coq9-ts19, on a non-fermentable carbon source and increases the content of Q6, by enhancing Q biosynthesis from 4-hydroxybenzoic acid (4HB). To study the mechanism for the rescue by human COQ9, we determined the steady-state levels of yeast Coq polypeptides in the mitochondria of the temperature-sensitive yeast coq9 mutant expressing human COQ9. We show that the expression of human COQ9 significantly increased steady-state levels of yeast Coq4, Coq6, Coq7, and Coq9 at permissive temperature. Human COQ9 polypeptide levels persisted at non-permissive temperature. A small amount of the human COQ9 co-purified with tagged Coq6, Coq6-CNAP, indicating that human COQ9 interacts with the yeast Q-biosynthetic complex. These findings suggest that human COQ9 rescues the yeast coq9 temperature-sensitive mutant by stabilizing the CoQ-synthome and increasing Q biosynthesis from 4HB. This finding provides a powerful approach to studying the function of human COQ9 using yeast as a model.

Influence of Hot and Cold Environments on the Regulation of Energy Balance Following a Single Exercise Session: A Mini-Review

Understanding the regulation of human food intake in response to an acute exercise session is of importance for interventions with athletes and soldiers, as well as overweight individuals. However, the influence of hot and cold environments on this crucial function for the regulation of body mass and motor performance has not been summarized. The purpose of this review was to exhaustively search the literature on the effect of ambient temperature during an exercise session on the subsequent subjective feeling of appetite, energy intake (EI) and its regulation. In the absence of stress due to environmental temperature, exercise-induced energy expenditure is not compensated by EI during an ad libitum meal following the session, probably due to decreased acylated ghrelin and increased peptide tyrosine tyrosine (PYY), glucagon-like peptide 1 (GLP-1), and pancreatic polypeptide (PP) levels. No systematic analysis has been yet made for major alterations of relative EI in cold and hot environments. However, observed eating behaviors are altered (proportion of solid/liquid food, carbohydrate/fat) and physiological regulation appears also to be altered. Anorexigenic signals, particularly PYY, appear to further increase in hot environments than in those that are thermoneutral. Ghrelin and leptin may be involved in the observed increase in EI after exercise in the cold, in parallel with increased energy expenditure. The potential influence of ambient thermal environment on eating behaviors after an exercise session should not be neglected.

Distribution and hormonal characterization of primary murine L cells throughout the gastrointestinal tract.

Aims/IntroductionGlucagon‐like peptide‐1 (GLP‐1) secreted from enteroendocrine L cells is an incretin that potentiates insulin secretion and is already applied in therapies for type 2 diabetes. However, detailed examination of L cells throughout the gastrointestinal tract remains unclear, because of difficulties in purifying scattered L cells from other cells. In the present study, we identified characteristics of L cells of the upper small intestine (UI), the lower small intestine (LI) and the colon using glucagon‐green fluorescent protein‐expressing mice that express GFP driven by the proglucagon promoter.Materials and MethodsThe localization and density of primary L cells were evaluated by anti‐green fluorescent protein antibody reactivity. GLP‐1 content, messenger ribonucleic acid (mRNA) expression levels and secretion in purified L cells were measured.ResultsThe number of L cells significantly increased toward the colon. In contrast, the GLP‐1 content and secretion from L cells were higher in the UI than in the LI and colon. L cells from the UI and LI expressed notably high mRNA levels of the transcription factor, islet 1. The mRNA expression levels of peptide YY in L cells were higher in the LI than in the UI and colon. The mRNA expression levels of gastric inhibitory polypeptide in L cells from the UI were significantly higher compared with those from the LI and colon.ConclusionsL cells show different numbers and characteristics throughout the gut, and they express different mRNA levels of transcription factors and gastrointestinal hormones. These results contribute to the therapeutic application of promoting GLP‐1 release from L cells for the treatment of type 2 diabetes.

Su1266 - Fasting Human Pancreatic Polypeptide (HPP) Level is not a Reliable Marker of Pancreatic Cancer, Chronic Pancreatitis or Type 3C (Pancreatogenic) Diabetes Mellitus (DM)

Su1266 - Fasting Human Pancreatic Polypeptide (HPP) Level is not a Reliable Marker of Pancreatic Cancer, Chronic Pancreatitis or Type 3C (Pancreatogenic) Diabetes Mellitus (DM)