Dataset Information

Protein kinase C-? contributes to impaired endothelial insulin signaling in humans with diabetes mellitus.

ABSTRACT: Abnormal endothelial function promotes atherosclerotic vascular disease in diabetes. Experimental studies indicate that disruption of endothelial insulin signaling, through the activity of protein kinase C-? (PKC?) and nuclear factor ?B, reduces nitric oxide availability. We sought to establish whether similar mechanisms operate in the endothelium in human diabetes mellitus.We measured protein expression and insulin response in freshly isolated endothelial cells from patients with type 2 diabetes mellitus (n=40) and nondiabetic controls (n=36). Unexpectedly, we observed 1.7-fold higher basal endothelial nitric oxide synthase (eNOS) phosphorylation at serine 1177 in patients with diabetes mellitus (P=0.007) without a difference in total eNOS expression. Insulin stimulation increased eNOS phosphorylation in nondiabetic subjects but not in diabetic patients (P=0.003), consistent with endothelial insulin resistance. Nitrotyrosine levels were higher in diabetic patients, indicating endothelial oxidative stress. PKC? expression was higher in diabetic patients and was associated with lower flow-mediated dilation (r=-0.541, P=0.02). Inhibition of PKC? with LY379196 reduced basal eNOS phosphorylation and improved insulin-mediated eNOS activation in patients with diabetes mellitus. Endothelial nuclear factor ?B activation was higher in diabetes mellitus and was reduced with PKC? inhibition.We provide evidence for the presence of altered eNOS activation, reduced insulin action, and inflammatory activation in the endothelium of patients with diabetes mellitus. Our findings implicate PKC? activity in endothelial insulin resistance.

SUBMITTER: Tabit CE

PROVIDER: S-EPMC3572725 | biostudies-literature | 2013 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Protein kinase C-β contributes to impaired endothelial insulin signaling in humans with diabetes mellitus.

Tabit Corey E CE Shenouda Sherene M SM Holbrook Monica M Fetterman Jessica L JL Kiani Soroosh S Frame Alissa A AA Kluge Matthew A MA Held Aaron A Dohadwala Mustali M MM Gokce Noyan N Farb Melissa G MG Rosenzweig James J Ruderman Neil N Vita Joseph A JA Hamburg Naomi M NM

Circulation 20121130 1

<h4>Background</h4>Abnormal endothelial function promotes atherosclerotic vascular disease in diabetes. Experimental studies indicate that disruption of endothelial insulin signaling, through the activity of protein kinase C-β (PKCβ) and nuclear factor κB, reduces nitric oxide availability. We sought to establish whether similar mechanisms operate in the endothelium in human diabetes mellitus.<h4>Methods and results</h4>We measured protein expression and insulin response in freshly isolated endo ...[more]

PMID: 23204109

Similar Datasets

Project description:ObjectiveGestational diabetes mellitus (GDM) is a serious complication in pregnancy. Despite controlling the plasma glucose levels with dietary intervention (GDM-D) or insulin therapy (GDM-I), children born of diabetic mothers suffer more long-term complications from childhood to early adulthood. Placental circulation and nutrient exchange play a vital role in fetal development. Additionally, placental endothelial function is an indicator of vascular health, and plays an important role in maintaining placental circulation for nutrient exchange. This study was conducted to assess changes in fetal endothelial dysfunction in GDM under different interventions during pregnancy.MethodsThe primary human umbilical vein endothelial cells (HUVECs) were obtained from normal pregnant women (n = 11), GDM-D (n = 14), and GDM-I (n = 12) patients. LC-MS/MS was used to identify differentially expressed proteins in primary HUVECs among the three groups, after which Bioinformatics analysis was performed. Glucose uptake, ATP level, apoptosis, and differentially expressed proteins were assessed to investigate changes in energy metabolism.ResultsA total of 8174 quantifiable proteins were detected, and 142 differentially expressed proteins were identified after comparing patients with GDM-D/GDM-I and healthy controls. Of the 142, 64 proteins were upregulated while 77 were downregulated. Bioinformatics analysis revealed that the differentially expressed proteins were involved in multiple biological processes and signaling pathways related to cellular processes, biological regulation, and metabolic processes. According to the results from KEGG analysis, there were changes in the PI3K/AKT signaling pathway after comparing the three groups. In addition, there was a decrease in glucose uptake in the GDM-I (P < 0.01) group. In GDM-I, there was a significant decrease in the levels of glucose transporter 1 (GLUT1) and glucose transporter 3 (GLUT3). Moreover, glucose uptake was significantly decreased in GDM-I, although in GDM-D, there was only a decrease in the levels of GLUT1. ATP levels decreased in GDM-I (P < 0.05) and apoptosis occurred in both the GDM-D and GDM-I groups. Compared to the normal controls, the levels of phosphate AKT and phosphate AMPK over total AKT and AMPK were reduced in the GDM-I group.ConclusionIn summary, endothelial dysfunction occurred in pregnancies with GDM even though the plasma glucose levels were controlled, and this dysfunction might be related to the degree of glucose tolerance. The energy dysfunction might be related to the regulation of the AKT/AMPK/mTOR signaling pathway.

Project description:Dysregulation in expression of microRNAs (miRNAs) in various tissues has been linked to a wide spectrum of diseases, including Type 2 Diabetes mellitus (T2D). In this study, we compared the expression profiles of miRNAs in blood samples from Impaired Fasting Glucose (IFG) and T2D male patients with tissues from T2D rat models. Healthy adult males with no past history of T2D (n=158) and with desirable cholesterol and blood pressure profiles were enrolled in this study. They were then classified according to fasting glucose levels to have T2D, IFG or as healthy controls (CTL), for comparison of miRNA expression profiles. Employing miRNA microarray, we identified ‘signature miRNAs’ in peripheral blood samples that distinguished IFG and T2D. Eight selected miRNAs were further validated using stem-loop real-time RT-PCR. miR-144 expression was found to be dysregulated in Type 2 Diabetes, wherein its expression was significantly higher than in healthy controls. Insulin receptor substrate 1 (IRS1) has been predicted to be a potential target of miR-144. Consistent with this observation, IRS1 mRNA and protein levels, verified by quantitative real-time PCR and western blotting respectively, were found to be down-regulated. Using luciferase assay, we further demonstrated that miR-144 directly targets IRS1 and showed its effects on protein expression via immunocytochemistry. From this cross-sectional study in humans, we have identified signature miRNAs which could explain the pathogenesis of T2D. Whether miRNAs like miR-144 could be potential therapeutic targets for management of T2D will need to be explored by further mechanistic and functional studies. miRNA profiling of tissues from T2D rat models. Total RNA (plus miRNAs) was isolated using a modification of the RiboPure™-Blood kit from Ambion (Austin,TX) according to the manufacturer’s protocol. The concentration of total RNA and integrity were determined by using Nano-Drop ND-1000 Spectrophotometry (NanoDrop Tech, Rockland, Del) and gel electrophoresis respectively.

Dataset Information

Protein kinase C-? contributes to impaired endothelial insulin signaling in humans with diabetes mellitus.

Publications

Protein kinase C-β contributes to impaired endothelial insulin signaling in humans with diabetes mellitus.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets