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Xinhui Liu,1 Xiuli Zhang,2,3 Xiaoyi Cai,2 Jiqiu Dong,2 Yinmao Chi,4 Zhihong Chi,3 Harvest F Gu5 1Traditional Chinese Medicine, Liaoning University of Traditional Chinese Medicine, Shenyang, Liaoning Province, 110847, People’s Republic of China; 2Department of Nephrology, Second People’s Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong Province, 518000, People’s Republic of China; 3Department of Pathophysiology, China Medical University, Shenyang, Liaoning Province, 110001, People’s Republic of China; 4Department of Physiology, China Medical University, Shenyang, Liaoning Province, 110001, People’s Republic of China; 5Center for Pathophysiology, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu Province, 210009, People’s Republic of ChinaCorrespondence: Xiuli ZhangDepartment of Nephrology, Second People’s Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong Province, 518000, People’s Republic of ChinaEmail zhangxiuli54321@sina.comHarvest F GuCenter for Pathophysiology, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu Province, 210009, People’s Republic of ChinaEmail feng.gu@cpu.edu.cnObjective: Diabetic kidney disease (DKD) is a microvascular complication in diabetes mellitus, while tubuloepithelial to mesenchymal transition (EMT) of mature tubular epithelial cells is a key point in the early development and progression of renal interstitial fibrosis. The present study aimed to investigate the protective effects of Curcumin on EMT and fibrosis in cultured normal rat kidney tubular epithelial cell line (NRK-52E).Methods: By using immunofluorescence staining and Western blot protocols, in vitro experiments were designed to analyze EMT markers, including collagen I and E-cadherin in high glucose (HG) exposed NRK-52E cells and to detect the expression levels of phosphorylated-NF-κB, TLR4 and reactive oxygen species (ROS) after Curcumin pre-treatment. With co-treatment with TAK242, these molecules in the TLR4-NF-κB signaling pathway were further evaluated.Results: Curcumin decreased the HG-induced EMT levels and ROS production in NRK-52E cells. Furthermore, Curcumin was found to inhibit the TLR4-NF-κB signaling activation in HG-induced EMT of NRK-52E cells.Conclusion: The present study provides evidence suggesting a novel mechanism that Curcumin exerts the anti-fibrosis effects via inhibiting activation of the TLR4-NF-κB signal pathway and consequently protecting the HG-induced EMT in renal tubular epithelial cells. Thereby, TLR4-NF-κB may be a useful target for therapeutic intervention in DKD.Keywords: diabetic kidney disease, tubuloepithelial to mesenchymal transition, toll-like receptor 4, curcumin, inflammation

Bone morphogenetic proteins (BMPs) are secreted ligands that belong to the transforming growth factor-β (TGF-β) superfamily. BMP7 has been reported to play a role in reversing obesity and regulating appetite in the hypothalamus. Whether BMP9 plays a central role in regulating glucose metabolism and insulin sensitivity remains unclear. Here, we investigated the impact of central BMP9 signaling and possible route of transmission. We performed intracerebroventricular (ICV) surgery and injected adenovirus expressing BMP9 (Ad-BMP9) into the cerebral ventricle of mice. Metabolic analysis, hyperinsulinemic-euglycemic clamp test, and analysis of phosphatidylinositol 3,4,5-trisphosphate (PIP3) formation were then performed. Real-time PCR and Western blotting were performed to detect gene expression and potential pathways involved. We found that hypothalamic BMP9 expression was downregulated in obese and insulin-resistant mice. Overexpression of BMP9 in the mediobasal hypothalamus reduced food intake, body weight, and blood glucose level, and elevated the energy expenditure in high-fat diet (HFD)-fed mice. Importantly, central treatment with BMP9 improved hepatic insulin resistance (IR) and inhibited hepatic glucose production in HFD-fed mice. ICV BMP9-induced increase in hepatic insulin sensitivity and related metabolic effects were blocked by ICV injection of rapamycin, an inhibitor of mammalian target of rapamycin (mTOR) signaling. In addition, ICV BMP9 promoted the ability of insulin to activate the insulin receptor/phosphoinositide 3-kinase (PI3K)/Akt pathway in the hypothalamus. Thus, this study provides insights into the potential mechanism by which central BMP9 ameliorates hepatic glucose metabolism and IR via activating the mTOR/PI3K/Akt pathway in the hypothalamus.

Previous cross-sectional studies have established that circulating osteoprotegerin (OPG) levels are associated with nonalcoholic fatty liver disease (NAFLD). However, the role of OPG in metabolic diseases, such as diabetes and NAFLD, is still unclear. In the current study, we demonstrated that hepatic OPG expression was downregulated in NAFLD individuals and in obese mice. OPG deficiency decreased lipid accumulation and expression of CD36 and peroxisome proliferator–activated receptor-γ (PPAR-γ) in the livers of OPG−/− mice and cultured cells, respectively, whereas OPG overexpression elicited the opposite effects. The stimulatory role of OPG in lipid accumulation was blocked by CD36 inactivation in hepatocytes isolated from CD36−/− mice. The overexpression of OPG led to a decrease in extracellular signal–regulated kinase (ERK) phosphorylation in the livers of OPG−/− mice and in cultured cells, while OPG deficiency resulted in the opposite effect. The inhibition of PPAR-γ or the activation of ERK blocked the induction of CD36 expression by OPG in cultured cells. Mechanistically, OPG facilitated CD36 expression by acting on PPAR response element (PPRE) present on the CD36 promoter. Taken together, our study revealed that OPG signaling promotes liver steatosis through the ERK–PPAR-γ–CD36 pathway. The downregulation of OPG in NAFLD might be a compensatory response of the body to dampen excess hepatic fat accumulation in obesity.

Purpose: High prevalence of nonalcoholic fatty liver disease (NAFLD) among patients with type 2 diabetes has implicated the role of hepatic insulin resistance (IR) in the diseases. To better understand the underlying mechanism, we have evaluated the pathophysiological effects of Liraglutide on NAFLD via the insulin signaling pathway. Patients and methods: A 2×2 factorial experiment was designed. High-fat diet (HFD)-induced NAFLD mice with diabetes were treated with Liraglutide for 10 weeks, while the control mice were saline-treated. Hepatic expressions of InsR, IGF-1R, IRS2, PI3K and Akt at mRNA and protein levels were analyzed with RT-PCR and Western blotting. Hematoxylin and eosin staining, Oil Red O staining and electron microscopy were used to visualize triglyceride accumulation in liver. Results: Liraglutide significantly decreased body weight, fasting blood glucose levels and HOMA-IR scores in HFD mice. Compared with the control mice fed with chow diet, hepatic expressions of InsR, IRS2, PI3K and Akt at both mRNA and protein levels in HFD mice were significantly reduced, but upregulated after Liraglutide treatment. Furthermore, Liraglutide treatment was found to improve hepatic steatosis. Conclusion: The current study thereby provides evidence that Liraglutide ameliorates NAFLD and improves hepatic steatosis mainly by upregulation of the IRS2/PI3K/Akt signaling mediators.

Genetic association studies have implicated that cartilage intermediate layer protein 2 (CILP-2) confers the risk susceptibility for type 2 diabetes (T2DM). However, it is still unknown whether CILP-2 is involved in the regulation of glucose homeostasis and insulin resistance (IR). In the current study, we initially observed that CILP-2 as a secreted protein was detected in both conditioned medium and lysates of cells transfected with an overexpressed vector. We then found that circulating CILP-2 levels had a progressive increase from normal to impaired glucose tolerance (a pre-diabetic status) and then to diabetes, which was correlated positively with waist-to-hip ratio, triglyceride, fasting blood glucose, 2-h blood glucose after glucose overload, HbA1c, fasting insulin, 2-h plasma insulin after glucose overload, and homeostasis model assessment of insulin resistance but negatively with HDL-C. CILP-2 expression was increased in the liver and muscle but decreased in adipose tissues of obese mice or T2DM patients. Furthermore, we demonstrated that CILP-2 circulating levels were affected by OGTT and Exenatide. CILP-2 overexpression resulted in impaired glucose tolerance and hepatic IR in vivo and increased PEPCK expression whereas suppressed phosphorylation of insulin receptor and Akt kinase in vitro. Based on these findings, we have identified a direct interaction between CILP-2 and PEPCK and suggested that CILP-2 plays an important role in the regulation of hepatic glucose production.

Objective. Hypoxia is central in the pathogenesis of diabetic retinopathy (DR). Hypoxia-inducible factor-1 (HIF-1) is the key mediator in cellular oxygen homeostasis that facilitates the adaptation to hypoxia. HIF-1 is repressed by hyperglycemia contributing by this to the development of complications in diabetes. Recent work has shown that the HIF-1A Pro582Ser polymorphism is more resistant to hyperglycemia-mediated repression, thus protecting against the development of diabetic nephropathy. In this study, we have investigated the effect of the HIF-1A Pro582Ser polymorphism on the development of DR and further dissected the mechanisms by which the polymorphism confers a relative resistance to the repressive effect of hyperglycemia. Research Design and Method. 703 patients with type 1 diabetes mellitus from one endocrine department were included in the study. The degree of retinopathy was correlated to the HIF-1A Pro582Ser polymorphism. The effect of glucose on a stable HIF-1A construct with a Pro582Ser mutation was evaluated in vitro. Results. We identified a protective effect of HIF-1A Pro582Ser against developing severe DR with a risk reduction of 95%, even when adjusting for known risk factors for DR such as diabetes duration, hyperglycemia, and hypertension. The Pro582Ser mutation does not cancel the destabilizing effect of glucose but is followed by an increased transactivation activity even in high glucose concentrations. Conclusion. The HIF-1A genetic polymorphism has a protective effect on the development of severe DR. Moreover, the relative resistance of the HIF-1A Pro582Ser polymorphism to the repressive effect of hyperglycemia is due to the transactivation activity rather than the protein stability of HIF-1α.

Objective Zinc is intimately involved in testosterone production. Zinc transporter 8 (ZnT8) is found to be localized in insulin secretory granules as a β-cell specific Zn transporter. The effect of ZnT8 and related zinc accumulation in steroidogenesis, however, is still unknown. The present study aimed to explore whether ZnT8 plays a role in the facilitation of zinc accumulation and regulation of testosterone synthesis in testicles. Methods Leydig cells were isolated from the testicles of human, CD-1 suckling and ZnT8-KO mice. Zn accumulation in mitochondria was induced by hCG stimulation. Transfection of hZnT8-EGFP and RNA interfere of mZnT8 were done in MLTC-1 cells. ZnT8 expression and its co-localization with steroidogenic acute regulatory (StAR) protein were analyzed with RT-PCR, Western blot and dual-fluorescent staining protocols. Serum testosterone levels in mice were determined with chemiluminescent enzyme immunoassay. Results ZnT8 was found to be presented in Leydig cells and up-regulated in suckling mouse Leydig cells and MLTC-1 cells after hCG administration, by which zinc accumulation occurred in mitochondria. ZnT8 gene silencing or knockout inhibited stimulated progesterone and testosterone production, reduced stimulated zinc accumulation and down-regulated phosphorylated steroidogenic acute regulatory (StAR) expression in Leydig cells. Furthermore, an inhibitor (H89) of PKA blocked hCG-stimulated progesterone caused by ZnT8 over-expression and zinc treatment. Conclusion The present study provided the first evidence that ZnT8 transports Zn into Leydig cell mitochondria with gonadotropin stimulation and suggests that ZnT8 may play a role in testosterone production via the PKA signaling pathway.

Aims Apoptosis and oxidant stress are known to be involved in the pathogenesis of diabetic kidney disease (DKD). We have previously reported that zinc transporter 7 in SLC30 family (SLC30A7) inhibits apoptosis in rat peritoneal mesothelial cells under high glucose (HG) conditions. In the current study, we aimed to investigate whether SLC30A7 had effect for anti-oxidant stress in renal tubular epithelial cells under HG. Methods SLC30A7 in HG-induced apoptosis in a normal rat kidney tubular epithelial cell line (NRK-52E cells)/kidneys of STZ-induced diabetic mice was examined and the activity of nuclear factor erythroid 2-related factor 2 (NFE2L2) was further analyzed by using real time RT-PCR, siRNA and Western blot protocols. Results SLC30A7 was found to be up-regulated, while NFE2L2 was activated in kidneys of STZ-induced diabetic mice and HG-induced apoptosis of NRK-52E cells. Knock-down of SLC30A7 with siRNA protocol resulted in lower intracellular free zinc levels in the cells and decreased zinc distribution in the Golgi apparatus. Furthermore, knock-down of NFE2L2 down-regulated its target HMOX1 gene expression, decreased SLC30A7 activity but increased HG-induced apoptosis. Conclusion The current study provides new evidence that SLC30A7 has anti-oxidant stress effects in HG-induced apoptosis via the NFE2L2/HMOX1 signal transduction pathway.

Diabetic kidney disease (DKD) is a complex disease, in which local inflammatory stress results from both metabolic and hemodynamic derangements. Intercellular adhesion molecule 1 (ICAM-1) is an acute-phase protein marker of inflammation. In the recent years, clinical observations have reported that increased serum/plasma ICAM-1 levels are positively correlated with albuminuria in the patients with type 1 (T1D) and type 2 diabetes (T2D). Genetic association studies have demonstrated that genetic polymorphisms, including SNP rs5498 (E469K, G/A), in the ICAM1 gene is associated with DKD. rs5498 is a nonsynonymous SNP and caused by substitution between E (Glu) and K (Lys) for ICAM-1 protein. In this review, we first summarized the genetic effects of ICAM1 E469K polymorphism in DKD and then demonstrated the possible changes of ICAM-1 protein crystal structures according to the genotypes of this polymorphism. Finally, we discussed the genetic effects of the ICAM1 E469K polymorphism and the biological role of increased circulating ICAM-1 protein and its formation changes in DKD.

Objective We examined whether established metabolic risk genetic variants in the population confer a risk for increased waist circumference in patients with schizophrenia spectrum disorders and also an association with schizophrenia spectrum disorders irrespective of waist circumference. Patients and methods We analyzed the association in (i) a case–case model in which patients with schizophrenia spectrum disorder with increased waist circumference (≥80 cm for women and ≥94 cm for men) (n=534) were compared with patients with normal waist circumference (

// Han Wang 1,* , Lin Du 1,* , Tong Wu 2 , Gangyi Yang 2 , Wenjing Hu 2 , Hansheng Wang 1 , Mengliu Yang 2 , Dongfang Liu 2 , Harvest F. Gu 3,4 , Zhiming Zhu 5 , Hongting Zheng 6 and Ling Li 1 1 The Key Laboratory of Laboratory Medical Diagnostics in The Ministry of Education and Department of Clinical Biochemistry, College of Laboratory Medicine, Chongqing Medical University, Chongqing, China 2 Department of Endocrinology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China 3 Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden 4 Center for Molecular Medicine, Karolinska Institute, Karolinska University Hospital, Solna, Stockholm, Sweden 5 Department of Hypertension and Endocrinology, Daping Hospital, Third Military Medical University, Chongqing Institute of Hypertension, Chongqing, China 6 Department of Endocrinology, Xinqiao Hospital, Third Military Medical University, Chongqing, China * These authors have contributed equally to this project Correspondence to: Ling Li, email: // Keywords : betatrophin; insulin resistance; metabolic disorders; interventional study; cell cross-talk; Gerotarget Received : August 15, 2017 Accepted : October 05, 2017 Published : October 16, 2017 Abstract Betatrophin has a closely relationship with metabolism. However, its effect on metabolism disorder remains unclear. This study was comprised of a series of cross-sectional and interventional studies in vivo and vitro . PCOS women with IR and healthy women were recruited from the general population and outpatients. Plasma betatrophin levels were measured with ELISA. Insulin sensitivity was assessed with EHC. Gene expressions at mRNA and protein levels were determined with RT-PCR and Western blotting. Influences of insulin, metformin, rosiglitazone and over- or knockdown-expression of betatrophin were analyzed ex vivo . Our results indicated that IR women had higher betatrophin levels compared with the controls. Circulating betatrophin was positively correlated with BMI, WHR, Fat%, triglyceride, total cholesterol, LDL-C, AUC glucose and AUC insulin , luteinizing Hormone, FAI and HOMA-IR but negatively with M-value. Metformin treatment in PCOS women with IR led to a reduction of betatrophin levels. Insulin stimulation in hepatocytes increased betatrophin expression. Metformin or rosiglitazone led to a reduction of betatrophin expression in insulin-stimulated hepatocytes. In hepatocytes/macrophages co-culture systems, betatrophin expression was significantly increased, whereas this increase was eliminated by rosiglitazone. In hepatocytes, overexpression and knockdown of betatrophin decreased or increased insulin-stimulated insulin receptor, protein kinase B and insulin receptor substrate-1 phosphorylation respectively. Serum from metformin-treated women with IR decreased betatrophin expression and reinforced insulin signals. Thus, the present study provides the in vivo and in vitro evidence, suggesting that there is a cell cross-talking between hepatocytes with macrophages for the regulating betatrophin and it may be a useful marker for IR and metabolic disorders.

Bone morphogenetic protein (BMP)-9 has been reported to regulate energy balance in vivo. However, the mechanisms underlying BMP9-mediated regulation of energy balance remain incompletely understood. Here, we investigated the role of BMP9 in energy metabolism. In the current study, we found that hepatic BMP9 expression was down-regulated in insulin resistance (IR) mice and in patients who are diabetic. In mice fed a high-fat diet (HFD), the overexpression of hepatic BMP9 improved glucose tolerance and IR. The expression of gluconeogenic genes was down-regulated, whereas the level of insulin signaling molecule phosphorylation was increased in the livers of Adenovirus-BMP9-treated mice and glucosamine-treated hepatocytes. Furthermore, BMP9 overexpression ameliorated triglyceride accumulation and inhibited the expression of lipogenic genes in both human hepatocellular carcinoma HepG2 cells treated with a fatty acid mixture as well as the livers of HFD-fed mice. In hepatocytes isolated from sterol regulatory element-binding protein (SREBP)-1c knockout mice, the effects of BMP9 were ablated. Mechanistically, BMP9 inhibited SREBP-1c expression through the inhibition of liver X receptor response element 1 activity in the SREBP-1c promoter. Taken together, our results show that BMP9 is an important regulator of hepatic glucose and lipid metabolism.-Yang, M., Liang, Z., Yang, M., Jia, Y., Yang, G., He, Y., Li, X., Gu, H. F., Zheng, H., Zhu, Z., Li, L. Role of bone morphogenetic protein-9 in the regulation of glucose and lipid metabolism.

Insulin-like growth factor binding-protein 2 (IGFBP-2) is secreted by differentiating white adipocytes. Clinical studies demonstrate that circulating IGFBP-2 levels associated inversely with body mass index (BMI) and insulin resistance. To explore possible epigenetic changes of the IGFBP2 gene in obesity, we analyzed DNA methylation and mRNA expression in adipocytes from different depots. Healthy lean controls (BMI = 24.5 ± 0.3 kg/m 2 , n = 19) and obese subjects (BMI > 35 kg/m 2 , n = 24) were recruited. All subjects were Swedish Caucasian. Visceral abdominal adipose tissue (VAT) and subcutaneous adipose tissue (SAT) fragments were homogenized. Genomic DNA and total RNAs were extracted. Four CpG sites in the IGFBP2 gene promoter region were analyzed with bisulfite pyrosequencing. IGFBP2 gene expression at mRNA levels was determined with TaqMan real time RT-PCR. Serum samples were used for measurement of circulating IGFBP-2 and leptin levels. IGFBP2 DNA methylation levels in VAT were increased in obese subjects compared with controls (P

Background Ghrelin modulates many physiological processes. However, the effects of intestinal ghrelin on hepatic glucose production (HGP) are still unclear. The current study was to explore the roles of intestinal ghrelin on glucose homeostasis and insulin signaling in the liver. Methods The system of intraduodenal infusion and intracerebral microinfusion into the nucleus of the solitary tract (NTS) in the normal chow-diet rats and pancreatic-euglycemic clamp procedure (PEC) combined with [3-3H] glucose as a tracer were used to analyze the effect of intestinal ghrelin. Intraduodenal co-infusion of ghrelin, tetracaine and Activated Protein Kinase (AMPK) activator (AICAR), or pharmacologic and molecular inhibitor of N-methyl-D-aspartate receptors within the dorsal vagal complex, or hepatic vagotomy in rats were used to explore the possible mechanism of the effect of intestinal ghrelin on HGP. Results Our results demonstrated that gut infusion of ghrelin inhibited duodenal AMP-dependent protein kinase (AMPK) signal pathways, increased HGP and expression of gluconeogenic enzymes, and decreased insulin signaling in the liver of the rat. Intraduodenal co-infusion of ghrelin receptor antagonist [D-Lys3]-GHRP-6 and AMPK agonist with ghrelin diminished gut ghrelin-induced increase in HGP and decrease in glucose infusion rate (GIR) and hepatic insulin signaling. The effects of gut ghrelin were also negated by co-infusion with tetracaine, or MK801, an N-methyl-D-aspartate (NMDA) receptor inhibitor, and adenovirus expressing the shRNA of NR1 subunit of NMDA receptors (Ad-shNR1) within the dorsal vagal complex, and hepatic vagotomy in rats. When ghrelin and lipids were co-infused into the duodenum, the roles of gut lipids in increasing the rate of glucose infusion (GIR) and lowering HGP were reversed. Conclusions The current study provided evidence that intestinal ghrelin has an effect on HGP and identified a neural glucoregulatory function of gut ghrelin signaling. Electronic supplementary material The online version of this article (10.1186/s12964-019-0321-y) contains supplementary material, which is available to authorized users.

Background: Bone morphogenetic proteins (BMPs) are secreted ligands of the transforming growth factor-β (TGF-β) superfamily of proteins. BMP7 has been reported to traverse obesity and regulates appetite in the hypothalamus. However, whether central BMP9 regulates glucose metabolism and insulin sensitivity remains unclear. In this study, we focused on the impacts of central BMP-9 signaling and possible route of transmission. Methods: We performed intracerebroventricular (ICV) surgery and injected adenovirus expressing BMP9 (Ad-BMP9) or adenovirus encoding enhanced green fluorescence protein (Ad-GFP) into cerebral ventricle of mice. Then metabolic analyses, hyperinsulinemic-euglycemic clamp (HEC) and analysis of PIP3 formation were fulfilled. Real-time PCR and Western blot were performed to investigate potential pathway. Findings: We exhibited that hypothalamic BMP9 expression was downregulated in obese or insulin resistance (IR) mice. Overexpression of BMP9 in the hypothalamus reduced food intake, body weight, blood glucose, and elevated energy expenditure in high fat diet (HFD)-fed mice. Importantly, central treatment of BMP9 improved hepatic IR and inhibited hepatic glucose production (HGP) in mice fed with HFD. The increased hepatic insulin sensitivity and the related metabolic impacts by central BMP9 were blocked by ICV rapamycin injection (an inhibitor of the mTOR signaling). In addition, ICV BMP9 promoted the ability of insulin to activate the insulin receptor (InsR)/PI3K/Akt kinase pathway in hypothalamus. Interpretation: This study provided insight into the potential mechanism by which central BMP9 ameliorates glucose metabolism and IR by promoting the ability insulin to activate the mTOR/PI3K/Akt signaling in the hypothalamus. Funding Statement: This work was supported by grants from National Natural Science Foundation (No:81873658, 81670755), the Natural Science Foundation Project of CQ (No. cstc2015jcyjA10084 and cstc2013 jcyjA 10067) and the Science and Technology Key Program of Health Bureau of Chongqing (2015ZDXM038). Declaration of Interests: The authors have no conflict of interests to declare. Ethics Approval Statement: In the study, all kinds of treatments for mice were strictly carried out in accordance with the administrative animal management method of Chongqing Medical University, and at the same time, they met the relevant regulations of the Ethics Society of Chongqing Medical University.

Obesity has become epidemic worldwide, and abdominal obesity has a negative impact on health. Current treatment options on obesity, however, still remain limited. It is then of importance to find a new target for anti-obesity drug development based upon recent molecular studies in obesity. Adenylate cyclase 3 (ADCY3) is the third member of adenylyl cyclase family and catalyses the synthesis of cAMP from ATP. Genetic studies with candidate gene and genome-wide association study approaches have demonstrated that ADCY3 genetic polymorphisms are associated with obesity in European and Chinese populations. Epigenetic studies have indicated that increased DNA methylation levels in the ADCY3 gene are involved in the pathogenesis of obesity. Furthermore, biological analyses with animal models have implicated that ADCY3 dysfunction resulted in increased body weight and fat mass, while reduction of body weight is partially explained by ADCY3 activation. In this review, we describe genomic and biological features of ADCY3, summarize genetic and epigenetic association studies of the ADCY3 gene with obesity and discuss dysfunction and activation of ADCY3. Based upon all data, we suggest that ADCY3 is a new target for anti-obesity drug development. Further investigation on the effectiveness of ADCY3 activator and its delivery approach to treat abdominal obesity has been taken into our consideration.

Bipolar patients are at a higher risk of developing metabolic disorders. Cardiovascular morbidity and mortality is twice the rate reported in the population. Antipsychotic medication increases the risk of metabolic abnormalities. However, bipolar disorder and schizophrenia have a similarly increased mortality from cardiovascular causes of death, although bipolar patients medicate with antipsychotic drugs to a much smaller extent than schizophrenic patients. Bipolar disorder and schizophrenia share substantial genetic risk components; thus, increased metabolic abnormalities is hypothesized to be an effect of specific sets of metabolic risk genes, which might overlap with the metabolic risk genes in schizophrenia. This study reports that a functional genetic variant of MTNR1B, previously implicated in the impairment of glucose-stimulated insulin release also in schizophrenia, was associated with elevated fasting glucose levels in bipolar patients and controls. This finding suggests that the MTNR1B-dependent vulnerability for elevated fasting plasma glucose levels is shared between bipolar disorder and schizophrenia.

JAZF zinc finger 1 (JAZF1) is involved in glucose and lipid metabolisms. However, its role in aging- and nutrient-related hepatic steatosis is unclear. In the current study, we demonstrated that JAZF1 expression was markedly down-regulated in obesity-associated mice and nonalcoholic fatty liver disease (NAFLD) patients. During aging, JAZF1 expression was gradually down-regulated in both C57BL/6 J and JAZF1-Tg mice. In JAZF1-Tg mice, body fat content and hepatosteatosis were protected from HFD-induced steatosis, and accompanied by decreased lipogenesis gene expression. The inhibitory effects of hepatic steatosis in JAZF1-Tg mice, however, were disappeared during aging. In hepatocytes, over-expression of JAZF1 attenuated, while knockdown of JAZF1 enhanced the expression of lipogenesis genes. The over-expressing of JAZF1 in hepatocytes displayed the increased adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and decreased sterol regulatory element-binding protein 1c (SREBP-1c) expression. The roles of JAZF1 were partially attenuated by Compound C. Mechanistically, JAZF1 suppressed SREBP-1c expression through the inhibition of transcriptional activity of liver X receptor response elements (LXREs) in the SREBP-1c promoter. Data illustrate that JAZF1 may have a crucial role in the regulation of age and nutrient-associated hepatosteatosis through an AMPK/SREBP-1c-dependent mechanism.

Background/Aims: Alarin has been reported to be related with increased food intake and body weight. The relationship of circulating Alarin with insulin resistance or metabolic syndrome (MetS), however, is unknown. This study aimed to investigate the physiological role of Alarin and its association with MetS in humans. Methods: Newly diagnosed MetS patients (n=237) and age-matched healthy subjects (n=192) were recruited for this study. Oral glucose tolerance test, treadmill exercise, lipid infusions and euglycemic-hyperinsulinemic clamp (EHCs) were performed. Circulating Alarin and TNFα levels were measured by ELISA. Results: Circulating Alarin levels were significantly higher in MetS patients compared with healthy subjects (0.46 ± 0.22 vs. 0.41 ± 0.14 µg/L, P < 0.01). In all studied subjects, circulating Alarin levels were positively correlated with WC, blood pressure, FBG, triglyceride, HbA1c, HOMA-IR, AUCglucose, and TNFα (P < 0.05 or P < 0.01). Multivariate logistic regression analyses revealed that circulating Alarin levels were correlated with MetS and insulin resistance. There was no significant change of circulating Alarin levels in the subjects with treadmill exercise for 45 min. In healthy individuals, however, glucose challenge, acute hyperglycemia and lipid infusions resulted in increased circulating Alarin levels, while acute hyperinsulinaemia transiently decreased circulating Alarin levels. Conclusion: The present study provides the evidence that circulating Alarin levels are associated with MetS and insulin resistance.

International audience; We aimed to characterize of the role of insulin-like growth factor-binding protein 7 (IGFBP-7) in heart failure (HT) pathophysiology. IGFBP-7 has been associated with cardiac hypertrophy and diastolic dysfunction in HF. In 86 patients with HF with a preserved ejection fraction (HFpEF) (ejection fraction [EF] >= 45%) and 79 with HF with a reduced ejection fraction (HFrEF), we assessed concentrations of serum IGFBP-7, correlations between serum IGFBP-7 and clinical data, diastolic function, and associations with outcome. IGFBP-7 was lower in HFpEF than HFrEF (102 vs 152 mu g/L, p

Intercellular adhesion molecule-1 (ICAM-1) is an inflammation cytokine. Previous studies have demonstrated that genetic polymorphisms in the ICAM-1 gene are associated with chronic inflammation and diabetic nephropathy. The present study aimed to investigate the association of ICAM-1 gene polymorphisms with type 2 diabetes (T2D) and diabetic peripheral neuropathy (DPN) in a Chinese Han population. Four valid single nucleotide polymorphisms (SNPs) in the ICAM-1 gene were genotyped in 672 control subjects, 787 T2D patients with and without DPN with TaqMan allelic discrimination. Single marker association analyses indicated that A allele of SNP rs5498 was associated with DPN (P = 0.037, OR 1.715, 95 % CI 1.027–2.865). Further analyses of clinical parameters according to the genotypes of this polymorphism demonstrated that T2D patients with DPN carrying AA and AG genotypes had higher risk of coronary heart disease compared with those carrying GG genotype (30.6 % vs. 11.5 %, P = 0.040). In SNP rs1799969, the difference of minor allele frequencies between the patients without and with DPN was found (0.02 vs 0.01, P = 0.014, OR 3.695, 95 % CI 1.211–11.277). SNP rs281432 had higher frequency of G allele in all T2D patients compared with control subjects (0.35 vs. 0.31, P = 0.041, OR 1.200, 95 % CI 1.008–1.428). The present study provides evidence that rs5498 (A/G E469K) polymorphism is associated with DPN in T2D, and also implicates that the association of ICAM-1 with DPN may be related to other vascular complications.

Background/Aims: Solute carrier family 12 member 3 (SLC12A3) encodes a sodium/chloride transporter in kidneys. Previous reports suggest that Arg913Gln polymorphism in this gene is associated with diabetic nephropathy (DN), but the data appear to be inconsistent. Up to now, there is no biological evidence concerning the effects of SLC12A3 in DN. In this study, we aim to evaluate the genetic effects of the SLC12A3 gene and its Arg913Gln polymorphism with genetic and functional analyses. Methods: We genotyped SLC12A3 genetic polymorphisms including Arg913Gln in 784 non-diabetes controls and 633 type 2 diabetes (T2D) subjects with or without DN in a Malaysian population and performed a meta-analysis of the present and previous studies. We further analyzed the role of slc12a3 in kidney development and progress of DN in zebrafish and db/db mice. Results: We found that SLC12A3 Arg913Gln polymorphism was associated with T2D (p = 0.028, OR = 0.772, 95% CI = 0.612-0.973) and DN (p = 0.038, OR = 0.547, 95% CI = 0.308-0.973) in the Malaysian cohort. The meta-analysis confirmed the protective effects of SLC12A3 913Gln allele in DN (Z-value = -1.992, p = 0.046, OR = 0.792). Furthermore, with knockdown of zebrafish ortholog, slc12a3 led to structural abnormality of kidney pronephric distal duct at 1-cell stage. Slc12a3 mRNA and protein expression levels were upregulated in kidneys of db/db mice from 6, 12, and 26 weeks at the age. Conclusion: The present study provided the first biological and further genetic evidence that SLC12A3 has genetic susceptibility in the development of DN, while the minor 913Gln allele in this gene confers a protective effect in the disease. i 2014 S. Karger AG, Basel

Objective The sympathetic nervous system (SNS) is linked to glucose, lipid, and protein metabolism. The α2A-adrenergic receptor (ADRA2A) is involved in the SNS and mediates inhibition of insulin secretion and lipolysis. The association of ADRA2A single-nucleotide polymorphisms (SNPs) with obesity and/or type 2 diabetes (T2D) was investigated. Design and Methods Genotyping was performed in a case–control study of 1,177 Swedish individuals, including lean and obese subjects with normal glucose tolerance (NGT) and T2D patients. ADRA2A mRNA expression was measured in pancreatic islets isolated from T2D patients and nondiabetic subjects. Results SNP rs553668 was associated with T2D in men (odds ratio [OR] = 1.47; 95% confidence interval [CI] = 1.08–2.01; P = 0.015) but this association was lost after adjusting for age and for body mass index (BMI). Associations were also detected when comparing obese NGT and lean NGT subjects (OR = 1.49; 95% CI = 1.07–2.07; P = 0.017), and in obese (OR = 1.62; 95% CI = 1.06–2.49; P = 0.026), but not in lean T2D. In women, multiple logistic regression regarding SNP rs521674 demonstrated an increased OR of 7.61 (95% CI = 1.70–34.17; P = 0.008) for T2D when including age as a covariant. Correcting for BMI removed the significant association. When age was included in the model, association also found when obese T2D patients were compared with lean NGT subjects (P = 0.041). ADRA2A mRNA expression in human pancreatic islets was detectable, but with no statistically significant difference between the diabetic and the control groups. Conclusions ADRA2A genetic polymorphisms are mainly associated with obesity and possibly with T2D in a Swedish population.

Recent reports have demonstrated that elevated plasma long pentraxin 3 (PTX3) levels are associated with cardiovascular and chronic kidney diseases. In the current study, we investigated the plasma PTX3 levels in 296 Malay subjects including the subjects with normal glucose tolerance (NGT) and type 2 diabetes (T2DM) patients with or without DN by using an enzyme-linked immune-sorbent assay. Results showed that in males, plasma PTX3 levels in T2DM patients without DN were lower than that in the subjects with NGT (2.78 versus 3.98 ng/mL;P=0.021). Plasma PTX3 levels in T2DM patients with DN were decreased compared to the patients without DN (1.63 versus 2.78 ng/mL;P=0.013). In females, however, no significant alteration of plasma PTX3 levels among NGT subjects and T2DM patients with and without DN was detected. Furthermore, an inverse correlation between PTX3 and body mass index was found in male subjects with NGT (P=0.012;r=-0.390), but not in male T2DM patients, neither in all females. The current study provided the first evidence that decreased plasma PTX3 levels are associated with T2DM and DN in Malay men and also suggested that PTX3 may have different effects in DN and chronic kidney diseases.

Alpha-2-adrenergic receptor (ADRA2A) is involved in the sympathetic nervous system and plays a role in the regulation of insulin secretion and lipolysis. Recent studies have indicated that the ADRA2A polymorphisms are associated with type 2 diabetes (T2DM) in Caucasians and African Americans. The present study aimed to evaluate the association between the ADRA2A polymorphisms and T2DM in a Chinese Han population. Two single-nucleotide polymorphisms (SNPs) rs521674 and rs553668 in the ADRA2A gene were genotyped in 2094 Chinese subjects (1042 T2DM patients and 1052 nondiabetic controls) by using the TaqMan allelic discrimination technique. A single-locus analysis indicated that SNP rs553668 was associated with T2DM (p=0.04). Further analysis indicated that the association of SNP rs553668 was found in T2DM patients with body mass index (BMI)25 kg/m(2) (p=0.03), but not in the patients with BMI≥25 kg/m(2) (p=0.56). This association was still significant in a recessive model (p=0.01, odds ratio=0.68, 95% confidence interval=0.51-0.92). In conclusion, the present study provides evidence that the ADRA2A polymorphism, rs553668, is associated with lean T2DM patients in a Chinese Han population. Further investigation to explore the role of ADRA2A in the regulation of body weight has been taken into our consideration.

Recent genome-wide association studies show that loci in FTO and melanocortin 4 receptor (MC4R) associate with obesity-related traits. Outside Western populations the associations between these variants have not always been consistent and in Indians it has been suggested that FTO relates to diabetes without an obvious intermediary obesity phenotype. We investigated the association between genetic variants in FTO (rs9939609) and near MC4R (rs17782313) with obesity- and type 2 diabetes (T2DM)-related traits in a longitudinal birth cohort of 2,151 healthy individuals from the Vellore birth cohort in South India. The FTO locus displayed significant associations with several conventional obesity-related anthropometric traits. The per allele increase is about 1% for BMI, waist circumference (WC), hip circumference (HC), and waist-hip ratio. Consistent associations were observed for adipose tissue-specific measurements such as skinfold thickness reinforcing the association with obesity-related traits. Obesity associations for the MC4R locus were weak or nonsignificant but a signal for height (P < 0.001) was observed. The effect on obesity-related traits for FTO was seen in adulthood, but not at younger ages. The loci also showed nominal associations with increased blood glucose but these associations were lost on BMI adjustment. The effect of FTO on obesity-related traits was driven by an urban environmental influence. We conclude that rs9939609 variant in the FTO locus is associated with measures of adiposity and metabolic consequences in South Indians with an enhanced effect associated with urban living. The detection of these associations in Indians is challenging because conventional anthropometric obesity measures work poorly in the Indian "thin-fat" phenotype.

Objective To investigate the magnitude of association of FTO variants with obesity, type 2 diabetes (T2DM), and related traits among Asian Indians. Methods Random-effect meta-analysis was performed on pooled data from eight studies (n = 28,394) for obesity and related traits and six studies (n = 24,987) for assessment of T2DM risk in Indians where FTO variants were reported. Results The minor A-allele of the FTO variant rs9939609 was associated with increased risk of obesity (OR 1.15, 95% CI 1.08-1.21, p = 2.14 × 10-5), BMI (β = 0.30 kg/m2, 95% CI 0.21-0.38, p = 4.78 × 10-11) and other regional adiposity measurements [waist (β = 0.74 cm, 95% CI 0.49-0.99), HC (β = 0.52, 95% CI 0.26-0.78), and waist-hip ratio (WHR) (β = 0.002, 95% CI 0.001-0.004)] in Indians (p ≤ 0.001). An increased risk for T2DM (OR 1.11; 95% CI 1.04-1.19, p = 0.002) was observed, which attenuated when adjusted for age, gender, and BMI (OR 1.09; 95%CI 1.02-1.16, p = 0.01). Conclusions Our study provides evidence of association between common FTO variant and obesity risk among Indians with comparable effect sizes as in Caucasians. The attenuation of FTO-T2DM risk on BMI adjustment reinforces that BMI does not fully account for the adiposity effects among Asian Indians who are more centrally obese. Copyright © 2013 The Obesity Society.

Abnormally increased skeletal-muscle-specific E3 ubiquitin ligase (MG53) is associated with the inhibition of insulin signalling and insulin resistance (IR) in animal models. Four community-based studies of Han Chinese populations were included in this study to test the association of variants of MG53 and type 2 diabetes (T2D). The results showed that rs7186832 and rs12929077 in MG53 were significantly associated with T2D and impaired fasting glucose (IFG) of females in the discovery-stage case–control study and cohort study respectively of rural population but not in the replication sample of urban population. In rural population, the fasting insulin (mU/L) of the subjects with AA, AG and GG genotypes in rs12929077 were 8.70 ± 8.05, 10.71 ± 11.16 and 13.41 ± 14.26, respectively, and increased linearly in T2D cases without medication treatment (P = 0.04). This variant was significantly associated with HOMA-IR (P = 0.020) and HOMA-IS (P = 0.023). In individuals with IFG, the insulin and HOMA-IR of AG carriers were significantly higher than those of AA carriers. In urban population, after glucose loading, there were significant differences in the 30-min glucose, the area under the curve (AUC) of 30-min glucose and the AUC of 120-min glucose according to the genotypes of rs7186832 and rs12929077 in males but not females. Our findings suggest that MG53 variants might confer risk susceptibility to the development of T2D of females and IR particularly in rural population. Electronic supplementary material The online version of this article (doi:10.1186/s40064-016-2218-1) contains supplementary material, which is available to authorized users.

Background: Metabolic risk factors represent a major cause of increased coronary heart disease morbidity and mortality among psychosis patients. Although antipsychotic medication may lead to hyperglycemia, an association to severe mental illness was established before the introduction of antipsychotics. Methods: We investigated the association between metabolic risk genes and elevated fasting glucose level in patients with schizophrenia spectrum disorder. We applied two association models; (i) case-case where psychosis patients with elevated fasting glucose level (≥5.6 mmol/l) or diagnosed diabetes (n=263) were compared to patients with normal glucose level (n=389), and (ii) case-control model where psychosis patients with elevated fasting glucose level were compared to population-derived controls (n=494). Association analyses were adjusted for age, sex, smoking, family history of diabetes, and waist circumference. (iii) We also investigated whether metabolic genes were associated with schizophrenia spectrum disorder independent of fasting glucose. Results: No differences between schizophrenia spectrum diagnoses regarding genetic associations with increased fasting glucose were detected. In a case-case model, a genetic variant in IGF2BP2 was associated with elevated fasting glucose level among persons with schizophrenia spectrum disorder. In a case-control model associations were found with genetic variants in the NOTCH2, THADA, WFS1, P2RX7, and MNTR1B. A genetic variant in PPARD was nominally associated with schizophrenia spectrum disorder independent of glucose level. Conclusion: Our findings indicate that common metabolic polymorphisms associated with elevated fasting glucose among schizophrenia spectrum disorder patients may at least partially be explained by increased vulnerability in schizophrenia spectrum disorders for genes associate with elevated fasting glucose in the population.

The IGF2BP2 gene is located on chromosome 3q27.2 within a region linked to type 1 diabetes (T1D), type 2 diabetes (T2D) and diabetic nephropathy (DN). Its protein functionally binds to 5'-UTR of the imprinting IGF2 gene. The present study aims to evaluate the IGF2BP2-IGF2 genetic effects in diabetes and DN.Three cohorts including T1D with and without DN (n=1139) of European descents from the GoKinD study, Swedish T1D with and without DN (n=303) and Czech control subjects without diabetes, T1D, T2D with and without DN (n=1418) were enrolled in TaqMan genotyping experiments for IGF2BP2 rs4402960 and IGF2 rs10770125. Igf2bp2 gene expression in kidney tissues of db/db and control mice at the ages of 5 and 26 weeks was examined with real time RT-PCR and Western blot.An association of IGF2BP2 rs4402960 with T2D in the Czech population was replicated. This IGF2BP2 polymorphism (P=0.037, OR=0.69 95% CI 0.49-0.98) was found to be associated with DN in male not in female patients with T1D selected from the GoKinD study. In the analyses of combined the GoKinD, Czech and Swedish populations, the association between IGF2BP2 polymorphism and DN in male patients with T1D was still significant (P=0.030, OR=0.73, 95% CI 0.54-0.97). IGF2 rs10770125 was also associated with DN in male T1D patients of the GoKinD population (P=0.038, OR=0.67 95% CI 0.46-0.98). There might be a genetic interaction between IGF2BP2 and IGF2 (P=0.05). The Igf2bp2 gene expression levels were increased in the kidneys of db/db mice compared to controls at the age of 5weeks but not at 26 weeks.The present study has replicated the association of IGF2BP2 rs4402960 with T2D in the Czech population and provided data suggesting that IGF2BP2 may have genetic interaction with IGF2 with a protective effect against DN in male patients with T1D.

Adenylyl cyclase 3 (AC3) is expressed in pancreatic islets of the Goto-Kakizaki (GK) rat, a spontaneous animal model of type 2 diabetes (T2D), and also exerts genetic effects on the regulation of body weight in man. In addition to pancreatic islets, the central nervous system (CNS) plays an important role in the pathogenesis of T2D and obesity by regulating feeding behavior, body weight and glucose metabolism. In the present study, we have investigated AC3 expression in pancreatic islets, striatum and hypothalamus of GK rats to evaluate its role in the regulation of glucose homeostasis. GK and Wistar rats at the age of 2.5 mo were used. A group of GK rats were implanted with sustained insulin release chips for 15 d. Plasma glucose and serum insulin levels were measured. AC3 gene expression levels in pancreatic islets, striatum and hypothalamus were determined by using real-time RT-PCR. Results indicated that plasma glucose levels in Wistar rats were found to be similar to insulin-treated GK rats, and significantly lower compared with non-treated GK rats. AC3 expression levels in pancreatic islets, striatum and hypothalamus of GK rats were higher compared with Wistar rats, while the levels were intermediate in insulin-treated GK rats. The AC3 expression display patterns between pancreatic islets and striatum-hypothalamus were similar. The present study thus provides the first evidence that AC3 is overexpressed in the regions of striatum and hypothalamus of brain, and similarly in pancreatic islets of GK rats suggesting that AC3 plays a role in regulation of glucose homeostasis via CNS and insulin secretion.

Polycystic ovary syndrome (PCOS) and type 2 diabetes (T2D) are two common metabolic disorders in reproductive-aged women, and both are associated with insulin resistance. Evidence has indicated that the growth hormone receptor (GHR) exon 3 polymorphism is associated with T2D and the GHRd3 allele may have the preventive effect on the disease. However, the genetic effect of this polymorphism on PCOS is unknown. The present study thus aims to evaluate the association between the GHR exon 3 polymorphism and PCOS.A total of 432 patients with PCOS and 441 healthy control subjects were included. All of them were Han Chinese women and well characterized. Genotyping experiments of GHR exon 3 polymorphism were performed with a standard protocol of PCR and gel electrophoresis.GHRd3 allele frequency in PCOS patients was significantly higher compared to the control subjects (19.1% vs. 14.3%; P=0.007, OR=1.416; 95% CI=1.099-1.825). Further analyses indicated that the GHRd3 allele was associated with increased waist and hip circumstance in healthy women (P=0.016; 0.003), and also with 1-h, 2-h and area under the curve (AUC) plasma glucose levels among PCOS patients (all P0.05). But, no association of GHR exon 3 polymorphism with insulin resistance in the patients was observed.The present study provides the first evidence that GHR exon 3 polymorphism is associated with PCOS in Han Chinese women. The GHRd3 allele may contribute to an impact of glucose metabolism but not insulin resistance.

Introduction Recent studies have indicated that methylation of the LINE-1 elements is associated with an increased risk of worsening carbohydrate metabolism. It has been shown that overall DNA methylation of LINE-1 elements could be considered as a risk factor for T2DM and its complications, independent of other established risk factors. Methods A total of 794 T2DM individuals from Salford, UK were included in this study (60% men n = 470). All patients had clinical and metabolic variables measured in 2002 (baseline outcomes) and annually through to 2016. Global LINE-1 DNA methylation was measured at four CpG sites. The QIAGEN PyroMark Q96 MD pyrosequencer was used to quantify methylation. Results The overall mean ± SD global LINE-1 methylation was 75.81 ± 3.25%. Cross-sectional linear regression analysis at baseline year 2002 showed that LINE-1 methylation was a significant predictor of diastolic BP (adjusted beta coefficient β = -0.25), estimated glomerular filtration rate (eGFR) (β = -0.48) and cholesterol HDL ratio (β = -0.04). A 10% increase in LINE-1 methylation was associated with a lower diastolic BP by 2.5 mm Hg, a lower eGFR by 4.8 ml/min/1.73 m2 and decreased cholesterol/HDL ratio by 0.4 mmol/L. Longitudinal analysis over the 14-year-follow-up periods showed that global LINE-1 methylation at baseline was associated with lower BMI in women [β = -0.25] and lower cholesterol: HDL ratio [β = -0.07]. A 10% increase in LINE-1 methylation was associated with reduction in BMI by 2.5 kg/m2 in women and reduction in cholesterol:HDL ratio by 0.7 mmol/L. Conclusion In a 14-year longitudinal cohort of T2DM individuals, relations between global LINE-1 DNA methylation status and specific metabolic markers were seen. Also, a higher degree of DNA methylation was predictive of less weight gain over time in women.

Aim of the study New options are needed to prevent and treat metabolic disorders associated with polycystic ovary syndrome (PCOS). Labisia pumila var. alata (LPva)—a Malaysian herb thought to have phytoestrogenic effects—has shown promise in reducing body weight gain in ovariectomized rats. In this study, we investigated the effect of LPva on body composition and metabolic features in female rats treated continuously with dihydrotestosterone, starting before puberty, to induce PCOS. Material and methods At 9 weeks of age, the PCOS rats were randomly subdivided into two groups; PCOS LPva and PCOS control. PCOS LPva rats received a daily oral dose of LPva (50 mg/kg body weight), dissolved in 1 ml of deionised water, for 4–5 weeks. PCOS controls received 1 ml of deionised water on the same schedule. Results LPva increased uterine weight (27%) and insulin sensitivity (36%) measured by euglycemic hyperinsulinemic clamp. Plasma resistin levels were increased and lipid profile was improved in LPva rats. In adipose tissue, LPva decreased leptin mRNA expression but did not affect expression of resistin and adiponectin. No effects on body composition, adipocyte size, or plasma leptin levels were observed. Conclusion LPva increases uterine weight, indicating estrogenic effects, and improves insulin sensitivity and lipid profile in PCOS rats without affecting body composition.

Background: Sex-determining region Y-box 2 (SOX2) is a transcription factor that plays an important role in the induction of pluripotent stem cells from somatic cells. The SOX2 gene is located in chromosome 3q26.33, in the linkage region of diabetes and diabetic nephropathy (DN). Evidence indicates that SOX2 is expressed in the adult human pancreas. Objective: This study investigated whether SOX2 is involved in the pathogenesis of diabetes and DN. Methods: A genetic association study of the unique tag single nucleotide polymorphism (SNP) rs11915160 of the SOX2 gene was conducted in patients with type 1 diabetes mellitus (T1DM), with or without DN, who were identified from the Genetics of Kidneys in Diabetes (GoKinD) study. Results: In 1120 patients with T1DM (591 women, 529 men), SNP rs11915160 was found to be significantly associated with DN (odds ratio [OR] = 0.720; P = 0.038) and end-stage renal disease (OR = 0.686; P = 0.034) in women but not in men. Compared with male T1DM patients without DN, female T1DM patients without DN who carried the CC, CA, or AA genotype had reversed distribution patterns in HDL-C, creatinine, cystatin, and glycosylated hemoglobin. Among the female patients with DN, carriers of the AA genotype had lower creatinine and cystatin levels compared with carriers of the CC or CA genotype. Furthermore, this SOX2 genetic polymorphism and the adiponectin promoter polymorphism rs266729 had combined effects on DN. Conclusions: The present study provides the first evidence that the SOX2 genetic polymorphism has gender-specific effects on DN, and also implies that transcription factors in pluripotency mechanisms may be involved in the pathogenesis of diabetes and DN.

OBJECTIVE—Nuclear respiratory factor 1 (NRF1) is a strong biological and positional candidate to contribute to type 2 diabetes susceptibility. This study aimed at evaluating associations between NRF1 genetic polymorphisms and development of type 2 diabetes. RESEARCH DESIGN AND METHODS—Using a variation screening approach, 6 novel and 10 known single nucleotide polymorphisms (SNPs) in the NRF1 gene were identified. Nine SNPs were then selected using pairwise tagging with an r2 cutoff of 0.8 and/or minor allele frequency of >5% and genotyped in 596 type 2 diabetic patients and 431 nondiabetic subjects, all of whom were Han Chinese. RESULTS—Two novel SNPs (−46127T>C and +98560A>G) were associated with type 2 diabetes (P = 0.018 and 0.036; for possession of minor allele, odds ratio [OR] 0.620 and 3.199, with dominant model and correction for multiple comparisons). In SNP rs1882094 (+141G>T), the nondiabetic control subjects carrying GG genotype had lower fasting plasma glucose levels than carriers with other genotypes (P = 0.0002). One common haplotype (H2) mainly composed of SNPs rs6969098 (−24833 A>G), rs1882094, and another novel variant (+97884G>A) was significantly associated with type 2 diabetes (P = 0.016, OR 0.706). Subjects with this haplotype had lower fasting triglyceride levels when compared with those with other haplotypes (P = 0.010). CONCLUSIONS—The present study shows an association of SNPs in the NRF1 gene with type 2 diabetes in a Han Chinese population. NRF1 genetic polymorphisms may be a suspectibility factor for type 2 diabetes by conferring abnormalities in triglyceride metabolism. Further studies should replicate this finding using larger and racially diverse populations.

ObjectiveThe distribution of Leu7Pro polymorphism in the neuropeptide Y gene shows a geographical north to south gradient of decreasing frequency, suggesting that it may be a population-specific causal variant. This polymorphism is found to be associated with diabetic nephropathy (DN) and coronary heart disease in Finnish women with type 1 diabetes (T1D). The present study aims to evaluate the susceptibility of this polymorphism to the development of DN in two different populations.DesignOne sample set consists of 174 (females 98 and males 76) Swedish T1D patients with DN and 249 (females 132 and males 117) patients without DN. Another sample set includes 597 (females 356 and males 241) American T1D patients without DN and 577 (females 264 and males 313) patients with DN, who were descents of European Caucasians and were from the Genetics of Kidneys in Diabetes (GoKinD) Study.MethodsGenotyping of Leu7Pro polymorphism was performed by dynamic allele-specific hybridization.ResultsThe C allele frequencies of Leu7Pro polymorphism in T1D patients between Swedish and American GoKinD populations were significantly different (6.3 vs 4.0%; P=0.006). Particularly, the C allele frequency in Swedish female T1D patients with DN was significantly higher in comparison with T1D patients without DN (10.2 vs 4.2%; P=0.011, OR=2.614, 95% confidence intervals: 1.249–5.467). No significant association of this polymorphism with DN was observed in Swedish male T1D patients and the patients from GoKinD.ConclusionsThe present study provides further evidence that Leu7Pro polymorphism confers the susceptibility to the development of DN in Swedish female T1D patients.

Objective: Previously, it has been demonstrated that receptor protein tyrosine phosphatase σ (RPTPσ) is involved in glucose homeostasis and insulin signaling in several animal models. The aim of this study was to evaluate whether polymorphisms in this gene influence the development of type 2 diabetes (T2D) in humans. Design: We investigated how genetic variations in the RPTPσ gene influence susceptibility to impaired glucose tolerance (IGT) and T2D, in Swedish men and women. Methods: Genotyping of single nucleotide polymorphisms (SNPs) was performed by dynamic allele-specific hybridization in a total of 1057 Swedish Caucasians including 497 subjects with normal glucose tolerance (NGT), 262 subjects with IGT, and 298 patients with T2D. Results: SNPs rs1143699, rs4807015, and rs1978237 were found to be associated with T2D. SNP rs1143699 was associated with male T2D patients when compared with NGT controls (odds ratio; OR = 1.57; P = 0.029). SNP rs4807015 showed association with T2D patients when compared with NGT controls (OR = 1.32; P = 0.025). Finally, SNP rs1978237 was associated with T2D patients when compared with NGT controls (OR = 1.59; P = 0.002). Logistic regression analysis demonstrated that for SNP rs1143699 in men, C/C homozygosity conveys an increased risk of T2D (OR = 2.19; P = 0.035), while SNP rs4807015 was associated with an increased risk of T2D in both men and women (OR = 1.74; P = 0.029). SNP rs1978237 also demonstrated a risk of T2D in men and women (OR = 1.59; P = 0.026). Conclusions: This study provides evidence for association of SNPs in the RPTPσ gene with T2D in Swedish Caucasians. SNPs rs1143699, rs4807015, and rs1978237 confer an increased risk of developing T2D.

Objective Dyslipidemia correlating to insulin resistance is one of the key features in type 2 diabetes (T2D). Recent studies have demonstrated that apolipoprotein M (apoM) is important for the formation of preβ-high-density lipoprotein (HDL) and cholesterol (CHO) efflux in macrophages to HDL. In the present study, we investigated the potential association of apoM genetic variation with the development of T2D. Methods Single nucleotide polymorphisms (SNPs) C-1065A, T-855C and T-778C in the proximal promoter region of apoM gene were validated to represent in Han Chinese. Further genotyping experiments in 170 T2D patients and 156 non-diabetic control subjects were performed with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results Single marker analysis for SNP T-778C indicated that T2D patients had increased frequency of C allele in comparison with non-diabetic controls (10.6% versus 5.8%, P = 0.026, OR = 1.934). In non-diabetic controls, the carriers with CT and CC genotypes had higher plasma CHO (221.7 versus 204.2 mg/dL, P = 0.033) and fasting plasma glucose (FPG) (92.6 versus 89.7 mg/dL, P = 0.041) levels than the subjects with TT genotype. Further analysis with adjustment for age, BMI, SBP, DBP, CHO and TG demonstrated that this SNP was strongly associated with T2D (P = 0.013, OR = 2.287). Haplotype analysis for those three SNPs, however, indicated that the common haplotypes were less informative than studying the role of the T-778C variant independently of the haplotype context. Conclusion The present study provided the first evidence that SNP T-778C in the proximal promoter region of apoM gene was associated with the levels of plasma CHO and FPG and also conferred the risk in the development of T2D among Han Chinese. Copyright © 2006 John Wiley & Sons, Ltd.

ObjectiveZinc-α2-glycoprotein (ZAG) has recently been characterized as a potent metabolic regulator. However, the effects of anti-diabetic agents on circulating ZAG levels in humans remain largely unknown. To explore the possible mechanisms by which the dipeptidyl peptidase-IV (DPP-IV) inhibitor improves insulin resistance, we investigated the effect of sitagliptin, a DPP-IV inhibitor, on circulating cytokine levels in newly diagnosed type 2 diabetes (nT2DM) patients.Design and methodsA subset of 141 subjects with nT2DM were assigned to receive placebo (n=47) or sitagliptin (n=94) for 3 months. Before and after treatment, subjects received a 75 g oral glucose tolerance test, euglycemic-hyperinsulinemic clamp (EHC), and measurement of ZAG and adiponectin (ADI) concentrations.ResultsCirculating ZAG levels were lower in nT2DM than in control individuals (PPPMvalues) during EHC were significantly increased (PPPConclusionA low level of circulating ZAG is associated with insulin resistance and sitagliptin treatment significantly increases circulating ZAG levels. These observations have implications in relation to the mode of action of the DPP-IV inhibitor as an insulin sensitizing agent.

Aims. To evaluate the antidiabetic effects ofGynostemma pentaphyllum(GP) in Goto-Kakizaki (GK) rat, an animal model of type 2 diabetes, and to investigate the mechanisms of insulin release.Methods. Oral glucose tolerance test was performed and plasma insulin levels were measured.Results. An oral treatment withGP(0.3 g/kg of body weight daily) for two weeks in GK rats improved glucose tolerance versus placebo group (P<0.01). Plasma insulin levels were significantly increased in theGP-treated group. The insulin release fromGP-treated GK rats was 1.9-fold higher as compared to the control group (P<0.001).GPstimulated insulin release in isolated GK rat islets at high glucose. Opening of ATP-sensitive potassium (K-ATP) channels by diazoxide and inhibition of calcium channels by nifedipine significantly decreased insulin response toGP. Furthermore, the protein kinase A (PKA) inhibitor H89 decreased the insulin response toGP(P<0.05). In addition,GP-induced insulin secretion was decreased after preincubation of GK islets with pertussis toxin to inhibit exocytoticGeproteins (P<0.05).Conclusion.The antidiabetic effect ofGPis associated with the stimulation of insulin release from the islets.GP-induced insulin release is partly mediated via K-ATP and L-type Ca2+channels, the PKA system and also dependent on pertussis toxin sensitiveGe-protein.

Metabolic syndrome (MetS), one of the major public health concerns, is regarded as the “common soil” of incidence of common chronic diseases and may increase the risk of type 2 diabetes. The predominant underlying mechanism of MetS is insulin resistance (IR). Additionally, previous studies have indicated that IGFBP7 has high affinity of binding with insulin and might induce IR. The objective of this study was to firstly evaluate the associations of serum IGFBP7 levels with IR and MetS with a relatively large sample and population based design. In a population based MetS case-control study, HOMA-IR was used to evaluate the insulin sensitivity and serum IGFBP7 levels were determined with chemiluminescence–linked immunoassay. As a result, the subjects of MetS and IR had higher serum levels of IGFBP7 than control healthy subjects. High serum IGFBP7 levels increased the risk of MetS and IR. Serum IGFBP7 levels were also found to be significantly correlated with metabolic-associated parameters of Waist-to-hip ratio (WHR), HDL and LDL. These findings suggest that serum IGFBP7 levels are associated with IR and MetS, providing new insight into the mechanism of IR and Mets. IGFBP7 may be a potential interventional target for IR and Mets.

Recent research has implicated that the inflammation may be a key pathophysiological mechanism in diabetic nephropathy (DN). Intercellular adhesion molecule 1 (ICAM-1) is an acute phase marker of inflammation. In the present study, we carried out genetic, epigenetic and protein analyses of ICAM-1 in a Malaysian population, including normal glucose tolerance (NGT) subjects and type 2 diabetes (T2D) patients with or without DN in order to evaluate its role in DN.Analyses of DNA polymorphism and methylation in the ICAM1 gene were performed with TaqMan allelic discrimination and pyrosequencing, respectively. Plasma ICAM-1 levels were determined using an enzyme-linked immune-sorbent assay kit.We found that the ICAM1 K469E(A/G) polymorphism (rs5498) was significantly associated with DN. Particularly, 86.1% of T2D patients with DN carried heterozygous genotype compared to the patients without DN (68.6%). Furthermore, plasma ICAM-1 levels were increased from NGT subjects to T2D patients without and with DN (P0.001). The NGT subjects carrying heterozygous genotype had significantly lower plasma ICAM-1 levels compared to the K469(A/A) genotype carriers (P=0.009). In the ICAM1 gene promoter, DNA methylation levels of CpG sites were low, and no association of the ICAM1 DNA methylation alteration with DN was detected.The present study provided evidence that the ICAM1 K469E(A/G) polymorphism with high heterozygous index and elevation of plasma ICAM-1 levels were associated with DN in a Malaysian population. Further prospective study of ICAM-1 protein according to the ICAM1 K469E(A/G) genotypes is necessary for predicting the susceptibility to T2D and DN.

Protein kinase C (PKC) is a family of protein kinases controlling protein phosphorylation and playing important roles in the regulation of metabolism. We have investigated expression levels of PKC isoforms in pancreatic islets and liver of diabetic Goto-Kakizaki (GK) rats with and without insulin treatment to evaluate their association with glucose homeostasis. mRNA and protein expression levels of PKC isoforms were assessed in pancreatic islets and liver of Wistar rats and GK rats with or without insulin treatment. PKCα and PKCζ mRNA expressions were down-regulated in islets of GK compared with Wistar rats. PKCα and phosphorylated PKCα (p-PKCα) protein expressions were decreased in islets of GK compared with insulin-treated GK and Wistar rats. PKCζ protein expression in islets was reduced in GK and insulin-treated GK compared with Wistar rats, but p-PKCζ was decreased only in GK rats. Islet PKCε mRNA and protein expressions were lower in GK compared with insulin-treated GK and Wistar rats. In liver, PKCδ and PKCζ mRNA expressions were decreased in both GK and insulin-treated GK compared with Wistar rats. Hepatic PKCζ protein expression was diminished in both GK rats with and without insulin treatment compared with Wistar rats. Hepatic PKCε mRNA expression was down-regulated in insulin-treated GK compared with GK and Wistar rats. PKCα, PKCε, and p-PKCζ expressions were secondary to hyperglycaemia in GK rat islets. Hepatic PKCδ and PKCζ mRNA expressions were primarily linked to hyperglycaemia. Additionally, hepatic PKCε mRNA expression could be under control of insulin.

AIM: The intercellular adhesion molecule-1 (ICAM-1) gene is located on chromosome 19p13, which is linked to Type 1 diabetes (T1D). ICAM-1 expression is related to development of T1D and diabetic ne ...

Neuropeptide Y (NPY) has been implicated in the control of food intake and energy balance based on many observations in animals. We have studied single nucleotide polymorphisms (SNPs) within the regulatory and coding sequences of the human NPY gene. One variant (1128 T>C), which causes an amino acid change from leucine to proline at codon 7 in the signal peptide of NPY, was associated with increased body mass index (BMI) in two separate Swedish populations of normal and overweight individuals. In vitro transcription and translation studies indicated the unlikelihood that this signal peptide variation affects the site of cleavage and targeting or uptake of NPY into the endoplasmic reticulum (ER). However, the mutant, and to a lesser extent the wild-type, signal peptide by themselves markedly potentiated NPY-induced food intake, as well as hypothalamic NPY receptor signaling. Our findings in humans strongly indicate that the NPY signaling system is implicated in body weight regulation and suggest a new and unexpected functional role of a signal peptide.

Sox2 is a transcription factor, which plays an important role in the induction of pluripotent stem cells from somatic cells. The Sox2 gene is located in chromosome 3q26.33 and resides in a linkage region of diabetes. In the present study, we attempted to evaluate the genetic effect of Sox2 in the development of type 2 diabetes (T2D). A total of 1598 Swedish subjects of T2D, pre-diabetes and non-diabetic control subjects were enrolled in the present study. Genotyping experiments for allelic discrimination of SNP rs11915160 were performed with TaqMan allelic discrimination. Sox2 mRNA expression levels in pancreatic islets of T2D patients (n = 16) and control subjects (n = 8) were detected by using real time RT-PCR. Among the non-diabetic control subjects with and without family history of diabetes (FHD, i.e. at least one first degree relative with diabetes or at least two second degree relatives with diabetes), the A allele frequency in Sox2 rs11915160 were 12.3% and 12.9%. This allele frequency was increased to 13.4% in T2D patients with FHD selected from SDPP and 17.9% in the patients with FHD from Kronan study, while the patients without FHD had the allele frequency at 12.4%. The difference of mRNA expression levels of the Sox2 gene in pancreatic islets between T2D patients and controls was not statistically significant. The present study thus suggests that Sox2 is unlikely to exert the genetic effect on the development of T2D.

Objective: Recent genetic studies have demonstrated that Single Nucleotide Polymorphism (SNP) rs35767(C/T) in the IGF1 gene promoter is associated with insulin resistance and serum IGF-I levels and thereby implicated that IGF1 has genetic effect in Type 2 Diabetes (T2D). The present study aimed to investigate the alteration of DNA methylation levels of the IGF1 gene in T2D. Subjects and methods: A total of 688 Swedish men with Normal Glucose Tolerance (NGT) or T2D were selected from Stockholm Diabetes Prevention Program. DNA methylation levels at rs35767 SNP-CpG site and other three CpG sites (P1-P3) in the IGF1 gene promoter region were analyzed with PyroMark Assays and bisulfite pyrosequencing. Fasting serum IGF-I levels were measured with an in-house radio-immunoassay. Results: DNA methylation levels at CpG site P3 of the IGF1 gene promoter were increased in T2D patients compared with NGT subjects (84.8% vs. 74.2%, P