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Objective:To assess the correlation between circulating chemerin and two indicators of renal function, estimated glomerular filtration rate (eGFR) and urine albumin creatinine ratio (UACR), in individuals with type 2 diabetes and to determine whether chemerin is an independent marker of early renal insufficiency.Methods:A total of 742 patients with type 2 diabetes were recruited into the cross-sectional community study. Basic information, anthropometric parameters, and biochemical parameters of these individuals were determined and collected, and serum chemerin level was measured using enzyme-linked immunosorbent assay.Results:Chemerin levels were significantly higher in the eGFR-impaired group compared with eGFR-normal group, and macroalbuminuria group compared to the normal or microalbuminuria groups. Spearman′ rank correlation analysis showed serum chemerin level was correlated with eGFR ( r=-0.25, P<0.001), UACR ( r=0.23, P<0.001) and some other biochemical indicators such as triglyceride. And univariate and multivariate logistic regression analyses revealed circulating chemerin was an independent risk factor for eGFR impairment or proteinuria after adjusting corresponding covariates. Receiver operating characteristic (ROC) curve analysis showed that the area under curve (AUC) of circulating chemerin for predicting early impaired eGFR in type 2 diabetes was 0.747, while the AUC of circulating chemerin for predicting macroalbuminuria in type 2 diabetes was 0.748. Conclusion:Circulating chemerin is associated with eGFR or UACR and may be a potential diagnostic marker for early renal insufficiency in type 2 diabetes.
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Objective:To investigate the relationship between serum lipocalin-2 level and the risk of cardiovascular disease(CVD) in patients with type 2 diabetes.Methods:A total of 279 type 2 diabetic patients were enrolled in this study. Basic information and clinical data were collected. These patients were divided into CVD group and non-CVD group according to their cardiovascular disease status. Serum lipocalin-2 level was assessed by enzyme linked immunosorbent assay.Results:Compared to non-CVD group, serum lipocalin-2 level was significantly higher in CVD group( P<0.01). The Spearman correlation analysis showed that serum lipocalin-2 level was positively correlated with waist circumstance, diastolic blood pressure, uric acid, triglyceride, and HbA 1C( P<0.05), while negatively correlated with high density lipoprotein-cholesterol level( P<0.01). In addition, the univariate and multivariate logistic regression analysis revealed that serum lipocalin-2 was an independent risk factor for CVD( P<0.01)after adjustment for potential confounders. Moreover, receiver operating characteristic curve analysis demonstrated that the area under curve value of lipocalin-2 was 0.74, with the optimal cutoff value of lipocalin-2 66.84 ng/mL. Conclusion:Serum lipocalin-2 is closely associated with CVD in patients with type 2 diabetes, which might be considered as one of the predictors for CVD in type 2 diabetes mellitus.
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Objective To investigate the impact of glucose metabolism-related protein 1 (GMRP1) on the regulation of c-Myc gene transcription, to establish GMRP1 gene knockout mouse model, and to study the influence of GMRP1 on glucose metabolism. Methods Chromatin immunoprecipitation-PCR (ChIP-PCR) was utilized to screen out the genes transcriptionally regulated by GMRP1. Luciferase reporter system was applied to assay the regulation of c-Myc promoter activity by GMRP1. GMRP1 knockout mice were constructed and validated by PCR and western blotting. Body weight and random blood glucose were measured in both knockout and wild type mice fed with either chow diet or high-fat diet. The levels of glucose metabolism in mice of 20 or 28 weeks old were evaluated by intraperitoneal glucose tolerance test. Results GMRP1 was capable of binding to the promoter of c-Myc gene and activating the expression of c-Myc gene. There were no significant differences in body weight, random blood glucose or glucose tolerance between GMRP1-deficient and wild type mice fed with either chow diet or high-fat diet (all P > 0.05). Conclusion GMRP1 may activate the transcription of c-Myc gene. GMRP1 deficiency exerted no significant effects on mouse glucose metabolism.
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It is well established that cardiovascular diseases are the leading causes of diabetes-related death. Endothelial dysfunction is widely accepted as the initial and critical factor contributing to diabetic vascular diseases. Insulin resistance may result in vascular endothelial dysfunction, which in turn aggravates diabetic vascular diseases. Via PI3K/Akt signaling pathway, insulin inhibits the function of FoxOs, which, endothelial FoxO1 especially, exerts an important role in atherosclerosis and angiogenesis. In this regard, Wang et al. characterized 10 FoxO1 target genes regulated by insulin in endothelial cells, among which, CITED2, a transcriptional coregulator, was selected to extensively investigate its role and the underlying mechanism of insulin-regulated angiogenesis. CITED2 was significantly increased in vascular endothelial cells in diet-induced mice, ob/ob mice, as well as obese type 2 diabetic patients, all of those models or subjects are accompanied by insulin resistance. In endothelial cells, insulin significantly down-regulated CITED2 expression through insulin receptor-PI3K-Akt-FoxO1 pathway. Inhibition of CITED2 resulted in significant increases in proliferation and tube formation of endothelial cells. Overexpression of CITED2, however, repressed the transactivation of HIF. The study on the mouse model with hind limb ischemia showed that endothelial CITED2 deficiency gave rise to significant increases of expression of endothelin-1, a well-known HIF target gene, induced by ischemia or hypoxia, suggesting that CITED2 inhibited endothelial angiogenesis via suppressing HIF transactivation. In summary, insulin resistance accompanying obesity and type 2 diabetes leads to enhanced CITED2 expression, consequently impairing HIF signaling and proangiogenic capacity in endothelial cells. Inhibition of CITED2 will be a promising novel way to deal with ischemic cardiovascular diseases in diabetic patients.
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Objective To observe the effect of acetylated low-density lipoprotein (AcLDL) on the expression of adipophilin and the effect of adipophilin on AcLDL uptake and lipid accumulation in human vascular smooth muscle cells (HVSMCs)in order to approach the role played by adipophilin in genesis of macroangiopathy. Methodse HVSMCs were treated with various amount of AcLDL. Adipophilin expression levels were detected by Northern blot and Western blot. The effects of adipophilin on AcLDL uptake and lipid accumulation in HVSMCs were observed by the methods of siRNA, flow cytometry, enzymatic method and oil red stain. Results AcLDL dose-dependently increased adipophilin expression in HVSMCs. Silence adipophilin by siRNA decreased AcLDL uptake (decreasing by 38.7%, P<0. 05) and lipids accumulation (tfiglyceride and total cholesterol decreasing by 30.6% and 29.8% respectively, both P<0. 01) in HVSMCs, Conclusion Adipophilin is able to increase AcLDL uptake and lipid accumulation in HVSMCs, suggesting that it might play a role in enhancing atherosclerosis.
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Objective: To investigate the effect of aqueous extract of Radix et Rhizome Rhodiolae on expressions of HIF-1?, HIF-1? and VEGF in human umbilical vein endothelial cells(HUVECs) exposed to hypoxia. Methods: The effect of different treatment time and concentrations of aqueous extract of Radix et Rhizome Rhodiolae on cellular proliferation were determined with XTT colorimetric assay. The mRNA and protein expressions of HIF-1?, HIF-1? and VEGF were analyzed respectively by quantitative real-time polymerase chain reaction with SYBR Green I and Western blot. Three groups were studied: normoxia control group, hypoxia control group, Radix et Rhizome Rhodiolae treatment group. Results: The optimal condition of Radix et Rhizome Rhodiolae treatment were 24h and 10?g/mL. The protein levels of HIF-1?, HIF-1? and VEGF were elevated by hypoxia (P
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AIM: To verify and localize the expression of nicotinamide N-methyltransferase (NNMT) in pancreas of streptozotocin(STZ)-induced diabetic monkeys and understand its important role in ?-cell destruction in the pathogenesis of diabetes. METHODS: Through an olig-microarray gene chip, NNMT was identified as the most obviously up-regulated genes in pancreas of STZ-induced diabetic monkeys versus controls. Semiquantitative RT-PCR and Western blotting were performed to verify the differential expression at mRNA and protein level respectively. Then the cellular localization of NNMT expression within pancreas was identified by immunohistochemical(IHC) staining.RESULTS: An obvious high expression of NNMT at both mRNA and protein levels was shown in pancreas of STZ-induced diabetic monkeys compared to that of controls. Further localization of the protein by IHC staining in pancreas specimens showed that its altered expression was restricted to central islets, most of which were ? cells.CONCLUSION: Expression of NNMT is increased in islets of STZ- induced diabetic monkeys, which infers that NNMT might participate in the process of ? cell damage in diabetes probably through the mechanism of energy metabolism disturbance.
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AIM: To clone and express the gene of SLC24A6, which provide the basis to illuminate the relationship between the SLC24A6 and insulin release. METHODS: The gene expression of SLC24A6 was analyzed in the insulinoma and normal pancreatic tissues by RT-PCR. The full-length cDNA sequence was subcloned into pET32a vector, and induced expression and purified in ROSSET (DE3) strain. At the same time, the ORF of SLC24A6 was cloned into green fluorescence protein vector pEGFP-C3 to study the location of SLC24A6 in the mouse insulinoma ?-TC3 cells. RESULTS: The mRNA expression of SLC24A6 in the human insulinoma tissue was significantly higher than that in normal pancreatic tissue. The fusion protein of SLC24A6 was a 80 kD protein and was purified successfully by prokaryotic vector in ROSSET strain. The localization of SLC24A6 in the mouse insulinoma ?-TC3 cells was located in the membrane of the cells. CONCLUSION: SLC24A6 might be related with insulin release. The prokaryotic expression of SLC24A6 provides the basis for the study on biological function and protein structure, and the location of SLC24A6 in the insulinoma cell will throw light on the relationship with insulin release.