In vitro studies have demonstrated that BVR-A is a substrate of the insulin receptor and regulates IRS1 by avoiding its aberrant activation, and in animal model of obesity the loss of hepatic BVR-A has been associated with glucose/insulin alterations and fatty liver disease.However, no studies exist in humans.
Additionally, the effects of LLAE on body weight, fat mass, glucose and lipid metabolism and the expression of PPARγ2, insulin receptor substrate 1 and glucose transporter 4 (GLUT4) in visceral adipose tissue (VAT) were measured in HFD-induced obese rats treated with low or high dose [0.5 or 3.0 g crude drug/(kg.d)] LLAE for 6 weeks.
Because IRS-1 is down-regulated in states of insulin resistance that occur in response to metabolic stresses such as obesity and cytokine stimulation, the findings provide a mechanism for understanding how patients with metabolic stress and/or diabetes are predisposed to developing vascular complications.
Evidence in obesity and type-2 diabetes suggests a role for a metabolic inflammasome ("metaflammasome") in mediating chronic inflammation in peripheral organs implicating IKKβ (inhibitor of nuclear factor kappa-B kinase subunit beta), IRS1 (insulin receptor substrate 1), JNK (c-jun N-terminal kinase), and PKR (double-stranded RNA protein kinase).
In accordance with previous studies, our findings suggest that the IRS1G972R R allele and RR+GR genotype have protective effects for CRC in overweight/obese patients and for obesity in patients with CRC.
This novel abnormality, increased interaction of multiple proteins with IRS1 in obesity and T2D in humans, provides new insights into the molecular mechanism of insulin resistance and identifies new targets for T2D drug development.
In addition to known driver mutations in TP53 and CTNNB1, our mutation analysis identified non-synonymous mutations in genes implicated in metabolic diseases, i.e. diabetes and obesity: IRS1, HMGCS1, ATP8B1, PRMT6 and CLU, suggesting a common molecular etiology for HCC of alternative pathogenic origin.
Two variants near IRS1, rs1522813 and rs2943641, were genotyped in 738 overweight/obese adults (age 60 ± 9 years; BMI 32.7 ± 3.9 kg/m2) randomly assigned to one of four weight-loss diets (a deficit of 750 kcal/day of caloric intake from baseline) varying in macronutrient contents for 2 years.
The aim of the present study was to determine the prevalence and association of the G972S polymorphism of the insulin receptor substrate-1 gene (IRS-1G972S SNP) with polycystic ovary syndrome (PCOS) and insulin resistance-related traits in a distinct phenotypic group of lean PCOS women with biochemical hyperandrogenemia, excluding obesity, which is considered to be an aggravating parameter of insulin resistance.
The aim of this study was to determine the incidence of the following polymorphisms in the following genes in 262 obese (BMI > or = 30) and 138 control (BMI < or = 25) subjects: leptin receptor (LEPR)-Gln223Arg, B3-adrenergic receptor (B3-AR)-Trp64Arg, serotonin transporter (5-HTT)--a 44-base pair insertion/deletion functional polymorphism in the 5-HTTLPR and insulin receptor substrate-1 (IRS-1)-Gly972Arg.
In vitro studies with rapamycin suggest that mTOR/S6K1 overactivation contributes to elevated serine phosphorylation of IRS-1, leading to impaired insulin signaling to Akt in liver and muscle of this dietary model of obesity.
The aim of this study was to evaluate the role of the IRS-1 gene G972R variant in 61 subjects with "uncomplicated" obesity [i.e. without diabetes, hypertension, dyslipidemia, coronary artery disease (CAD)], studied by hyperinsulinemic-euglycemic clamp.
Several studies indicate the possible role of mutations of the insulin receptor substrate-1 (IRS-1) gene in the pathogenesis of insulin-resistance and suggest a possible interaction between the IRS-1 gene and obesity, either by an effect on the development of obesity or by causing or aggravating the obesity-associated insulin resistance.