Genetic and pharmacological inhibition of Rho-associated kinase II enhances adipogenesis.

Rho-associated kinase (ROCK) regulates reorganization of actin cytoskeleton. During adipogenesis, the structure of filamentous actin is converted from long stress fibers to cortical actin, suggesting that the ROCK is involved in adipogenesis. Two ROCK isoforms have been identified: ROCK-I and ROCK-II.

Insulin-induced lipohypertrophy: report of a case with histopathology.

An 82-year-old woman with type 2 diabetes had been treated with recombinant human insulin for 16 years. She developed large swellings in both sides of her lower abdomen. The masses were soft, painless, and located around her insulin injection sites.

Transgenic expression of mutant peroxisome proliferator-activated receptor gamma in liver precipitates fasting-induced steatosis but protects against high-fat diet-induced steatosis in mice.

Steatosis is one of the most common liver diseases and is associated with the metabolic syndrome. A line of evidence suggests that peroxisome proliferator-activated receptor (PPAR) alpha and PPARgamma are involved in its pathogenesis. Hepatic overexpression of PPARgamma1 in mice provokes steatosis, whereas liver-specific PPARgamma disruption ameliorates steatosis in ob/ob mice, suggesting that hepatic PPARgamma functions as an aggravator of steatosis.

CCAAT/enhancer binding protein alpha maintains the ability of insulin-stimulated GLUT4 translocation in 3T3-C2 fibroblastic cells.

In 3T3-L1 preadipocytes, hormonal induction causes adipose conversion and facilitates the expression of insulin-sensitive glucose transporter, GLUT4. Evidence has accumulated that, in 3T3-L1 preadipocytes, the formation of GLUT4 storage vesicle and its translocation to plasma membrane precede both lipid accumulation and expression of GLUT4 and C/EBPalpha, a key transcription factor for adipose differentiation. On the other hand, 3T3-C2 fibroblastic cells, a subline of 3T3-L1, follow adipogenic process till mitotic clonal expansion stage (2 days after hormonal induction), but do not proceed to terminal differentiation stage (8 days after the induction), resulting in a lack of adipose conversion and GLUT4 expression.

Skeletal muscle AMP-activated protein kinase phosphorylation parallels metabolic phenotype in leptin transgenic mice under dietary modification.

Leptin augments glucose and lipid metabolism independent of its effect on satiety. Administration of leptin in rodents increases skeletal muscle beta-oxidation by activating AMP-activated protein kinase (AMPK). We previously reported that, as hyperleptinemic as obese human subjects, transgenic skinny mice overexpressing leptin in liver (LepTg) exhibit enhanced insulin sensitivity and lipid clearance.

Antidiabetic and adipogenic properties in a newly synthesized thiazolidine derivative, FPFS-410.

We report here a newly synthesized cyanoimino-oxothiazolidine derivative, FPFS-410, which has properties to ameliorate both hyperglycemia and dyslipidemia. Treatment of genetically obese-diabetic db/db mice with FPFS-410 markedly ameliorates severe hyperglycemia and hypertriglyceridemia. Although the oxothiazolidine ring of FPFS-410 shares a structural similarity with other thiazolidinedione derivatives, reporter assays showed that FPFS-410 was much less potent to activate peroxisome proliferators-activated receptor gamma (PPAR gamma) as compared with pioglitazone.

An angiotensin II AT1 receptor antagonist, telmisartan augments glucose uptake and GLUT4 protein expression in 3T3-L1 adipocytes.

Evidence has accumulated that some of the angiotensin II AT1 receptor antagonists have insulin-sensitizing property. We thus examined the effect of telmisartan on insulin action using 3T3-L1 adipocytes. With standard differentiation inducers, a higher dose of telmisartan effectively facilitated differentiation of 3T3-L1 preadipocytes.