Hyperandrogenism and Metabolic Syndrome Are Associated With Changes in Serum-Derived microRNAs in Women With Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) remains one of the most common endocrine disorder in premenopausal women with an unfavorable metabolic risk profile. Here, we investigate whether biochemical hyperandrogenism, represented by elevated serum free testosterone, resulted in an aberrant circulating microRNA (miRNAs) expression profile and whether miRNAs can identify those PCOS women with metabolic syndrome (MetS). Accordingly, we measured serum levels of miRNAs as well as biochemical markers related to MetS in a case-control study of 42 PCOS patients and 20 Controls. Patients were diagnosed based on the Rotterdam consensus criteria and stratified based on serum free testosterone levels (≥0.034 nmol/l) into either a normoandrogenic (n = 23) or hyperandrogenic (n = 19) PCOS group. Overall, hyperandrogenic PCOS women were more insulin resistant compared to normoandrogenic PCOS women and had a higher prevalence of MetS. A total of 750 different miRNAs were analyzed using TaqMan Low-Density Arrays. Altered levels of seven miRNAs (miR-485-3p, -1290, -21-3p, -139-3p, -361-5p, -572, and -143-3p) were observed in PCOS patients when compared with healthy Controls. Stratification of PCOS women revealed that 20 miRNAs were differentially expressed between the three groups. Elevated serum free testosterone levels, adjusted for age and BMI, were significantly associated with five miRNAs (miR-1290, -20a-5p, -139-3p, -433-3p, and -361-5p). Using binary logistic regression and receiver operating characteristic curves (ROC), a combination panel of three miRNAs (miR-361-5p, -1225-3p, and -34-3p) could correctly identify all of the MetS cases within the PCOS group. This study is the first to report comprehensive miRNA profiling in different subgroups of PCOS women with respect to MetS and suggests that circulating miRNAs might be useful as diagnostic biomarkers of MetS for a different subset of PCOS

Micromanaging Glucose Tolerance and Diabetes

MicroRNAs (miRNAs) are endogenous non-coding RNAs that have significant roles in biological processes such as glucose homoeostasis. MiRNAs fine-tune target genes expression via sequence-specific binding of their seed sequence to the untranslated region of mRNAs and degrade target mRNAs. MicroRNAs in islet β-cells regulate β-cell differentiation, proliferation, insulin transcription and glucose-stimulated insulin secretion. Furthermore, miRNAs play key roles in the regulation of glucose and lipid metabolisms and modify insulin sensitivity by controlling metabolic functions in main target organs of insulin such as skeletal muscle, liver and adipose tissue. Moreover, since circulating miRNAs are detectable and stable in serum, levels of certain miRNAs seem to be novel biomarkers for prediction of diabetes mellitus. In this article, due to the prominent impact of miRNAs on diabetes, we overviewed the microRNAs regulatory functions in organs related to insulin resistance and diabetes and shed light on their potential as diagnostic and therapeutic markers for diabetes

Prolonged incubation with Metformin decreased angiogenic potential in human bone marrow mesenchymal stem cells

WOS: 000450101800149PubMed ID: 30372835Metformin is commonly prescribed as a hypoglycemic agent following the onset of type 2 diabetes mellitus. This study aimed to investigate pro-and/or anti-angiogenic effects of Metformin on human bone marrow mesenchymal stem cells. Cells were incubated with different doses of Metformin including 0.5, 1, 10, 50, 100, 200 and 500 mu M for 14 days. Cell viability and total fatty acids profile were examined by MTT and gas chromatography methods. Differentiation of cells to endothelial lineage was studied by monitoring the expression of VEGFR-2 and Tie-2 receptors and VE-cadherin via real-time PCR and western blotting. Angiogenic potential and migration of cells were assessed by tubulogenesis and Transwell migration assays. PCR array was performed to analyze mTOR signaling. CD133(+) and VEGFR-2(+) cells were detected in blood samples of non-diabetic control, diabetic subjects and diabetics received Metformin. Metformin dose-dependently reduced cell survival. Decreased content of palmitate and oleate coincided increased level of stearate, palmitoleate, and linoleate (p 0.05). These data support a notion that Metformin could blunt the angiogenic behavior of human mesenchymal stem cells by modulating mTOR signaling pathway.Tabriz University of Medical Sciences [5.4.2187]This study was supported by a grant (No: 5.4.2187) from Tabriz University of Medical Sciences. The authors would like to appreciate the personnel of the Stem Cell Research Center, Tabriz University of Medical Sciences

Association of usf1s2 variant in the upstream stimulatory factor 1 gene with premature coronary artery disease in southern population of Iran

Background: Polymorphisms of the upstream transcription factor 1 (USF1) have been associated with familial combined hyperlipidemia (FCHL), type 2 diabetes and coronary heart diseases (CHD). In the current investigation, the association of USF1s2 variant of human USF1 gene with premature coronary artery disease (PCAD) was evaluated in a population from southern Iran. USF1s2 has the best potential as a functional variant .in the USF1 gene. Methods: In a case-control study USF1s2 variant of human USF1 gene was determined by polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) technique using BsiHKA I restriction enzyme for 186 women under 55 years of age and 135 men less than 50 years of age who underwent diagnostic coronary angiography in Saadi, Nemazee and Kowsar Hospitals of Shiraz, between July 2009 and March 2012. Data on the history of familial myocardial infarction or other heart diseases, hypertension, and smoking habit were collected by a simple questionnaire. Blood sugar level and serum lipid profile of all participants were also obtained by measuring the levels of fasting blood sugar (FBS), total cholesterol (TC), triglycerides (TG), low density lipoprotein (LDL) and high-density lipoprotein cholesterol (HDL). Results: Frequencies of the major (G) and minor (A) alleles of usf1s2 gene variant were 0.74 and 0.26 in the whole population, respectively. Meanwhile, the prevalence of the minor allele was significantly higher in PCAD patients compared with control subjects. This difference remained significant even after adjustment for confounding parameters. Indeed, subjects with mutant homozygous genotype (AA) were about 5 times more likely to suffer from early-onset CAD than those with wild-type homozygous genotype (GG). Moreover, the baseline characteristics of the control subjects and patients were statistically similar for almost all parameters except for the number of male individuals; there was no significant difference among various genotypes in the patient group for any of these investigated variables. Conclusion: It appears that the usf1s2 variant in upstream transcription factor 1 gene is an independent predictor of premature coronary artery disease in our population and applies its effects without affecting blood sugar and lipid levels

Inhibition of MEK/ERK1/2 Signaling Affects the Fatty Acid Composition of HepG2 Human Hepatic Cell Line

Introduction: The extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase pathway, also known as the MEK/ERK1/2 kinase cascade, has recently been implicated in the regulation of lipid metabolism and fatty liver disease. However, its functional effect on cellular fatty acid composition is unknown. Herein, we examined the effect of a pharmacological inhibitor of MEK, the upstream kinase activator of ERK1/2, on fatty acid composition of hepatocellular carcinoma cell line HepG2. Methods: HepG2 cells cultured in RPMI-1640 were exposed to the commonly used ERK1/2 pathway inhibitor PD98059 and were investigated with respect to fatty acid composition by gas-liquid chromatography. Results: Exposure of cells to the ERK1/2 pathway inhibitor induced an increase in monounsaturated fatty acids and the fatty acid desaturation index and a decrease in polyunsaturated fatty acid content. Specifically, we showed a significant increase of oleic acid (18:1n‑9; +29%, P=0.003) and arachidonic acid (20:4n‑6)/linoleic acid (18:2n‑6) ratio (3.5-fold; P<0.001) in HepG2 cells. Conclusion: Cellular fatty acid composition of HepG2 cells appeared to be differentially regulated by ERK1/2 pathway, thus suggesting related metabolic pathways as potential mediators of the effects of ERK1/2 signaling on hepatic fatty acid composition