Increased SRF transcriptional activity in human and mouse skeletal muscle is a signature of insulin resistance.

Insulin resistance in skeletal muscle is a key phenotype associated with type 2 diabetes (T2D) for which the molecular mediators remain unclear. We therefore conducted an expression analysis of human muscle biopsies from patients with T2D; normoglycemic but insulin-resistant subjects with a parental family history (FH(+)) of T2D; and family history-negative control individuals (FH(–)). Actin cytoskeleton genes regulated by serum response factor (SRF) and its coactivator megakaryoblastic leukemia 1 (MKL1) had increased expression in T2D and FH(+) groups.

Early life nutrition modulates muscle stem cell number: implications for muscle mass and repair.

Suboptimal nutrition during prenatal and early postnatal development is associated with increased risk for type 2 diabetes during adult life. A hallmark of such diabetes risk is altered body composition, including reduced lean mass and increased adiposity. Since stem cell number and activity are important determinants of muscle mass, modulation of perinatal nutrition could alter stem cell number/function, potentially mediating developmentally programmed reductions in muscle mass.

Accelerated postnatal growth increases lipogenic gene expression and adipocyte size in low-birth weight mice.

Objective: To characterize the hormonal milieu and adipose gene expression in response to catch-up growth (CUG), a growth pattern associated with obesity and diabetes risk, in a mouse model of low birth weight (LBW).

Research Design And Methods: ICR mice were food restricted by 50% from gestational days 12.5-18.

Necdin and E2F4 are modulated by rosiglitazone therapy in diabetic human adipose and muscle tissue.

To identify novel pathways mediating molecular mechanisms of thiazolidinediones (TZDs) in humans, we assessed gene expression in adipose and muscle tissue from six subjects with type 2 diabetes before and after 8 weeks of treatment with rosiglitazone. mRNA was analyzed using Total Gene Expression Analysis (TOGA), an automated restriction-based cDNA display method with quantitative analysis of PCR products. The expression of cell cycle regulatory transcription factors E2F4 and the MAGE protein necdin were similarly altered in all subjects after rosiglitazone treatment.

Sexual differentiation, pregnancy, calorie restriction, and aging affect the adipocyte-specific secretory protein adiponectin.

Adiponectin or adipocyte complement-related protein of 30 kDa (Acrp30) is a circulating protein produced exclusively in adipocytes. Circulating Acrp30 levels have been associated with insulin sensitivity in adult mice and humans, yet the Acrp30 profile over the lifespan and its hormonal regulation in vivo have not been previously described. Hence, we set forth to determine whether hormonal and metabolic changes associated with sexual maturation, reproduction, aging, and calorie restriction affect Acrp30.