germanium and Insulin-Resistance

Obese patients with chronic inflammation in white adipose tissue (WAT) have an increased risk of developing non-alcoholic steatohepatitis (NASH). The C-C chemokine receptor-2 (CCR2) has a crucial role in the recruitment of immune cells to WAT and liver, thereby promoting the inflammatory component of the disease. Herein, we examined whether intervention with propagermanium, an inhibitor of CCR2, would attenuate tissue inflammation and NASH development.. Male C57BL/6J mice received a high-fat diet (HFD) for 0, 6, 12 and 24 weeks to characterize the development of early disease symptoms of NASH, i.e. insulin resistance and WAT inflammation (by hyperinsulinemic-euglycemic clamp and histology, respectively) and to define the optimal time point for intervention. In a separate study, mice were pretreated with HFD followed by propagermanium treatment (0.05% w/w) after 6 weeks (early intervention) or 12 weeks (late intervention). NASH was analyzed after 24 weeks of diet feeding.. Insulin resistance in WAT developed after 6 weeks of HFD, which was paralleled by modest WAT inflammation. Insulin resistance and inflammation in WAT intensified after 12 weeks of HFD, and preceded NASH development. The subsequent CCR2 intervention experiment showed that early, but not late, propagermanium treatment attenuated insulin resistance. Only the early treatment significantly decreased Mcp-1 and CD11c gene expression in WAT, indicating reduced WAT inflammation. Histopathological analysis of liver demonstrated that propagermanium treatment decreased macrovesicular steatosis and tended to reduce lobular inflammation, with more pronounced effects in the early intervention group. Propagermanium improved the ratio between pro-inflammatory (M1) and anti-inflammatory (M2) macrophages, quantified by CD11c and Arginase-1 gene expression in both intervention groups.. Overall, early propagermanium administration was more effective to improve insulin resistance, WAT inflammation and NASH compared to late intervention. These data suggest that therapeutic interventions for NASH directed at the MCP-1/CCR2 pathway should be initiated early.

Topics: Adipose Tissue; Animals; Anti-Inflammatory Agents; Arginase; CD11 Antigens; Chemokine CCL2; Diet, High-Fat; Germanium; Insulin Resistance; Male; Mice; Mice, Inbred C57BL; Non-alcoholic Fatty Liver Disease; Organometallic Compounds; Propionates; Receptors, CCR2

Adipose tissue inflammation induced by macrophage infiltration through the MCP-1/CCR2 pathway is considered to play a pivotal role in the development of visceral obesity and insulin resistance. In the present study, therefore, we examined whether pharmacological inhibition of CCR2 is effective against the development of diet-induced metabolic disorders.. C57BL/6 mice were fed a high fat and sucrose diet with or without propagermanium (CCR2 inhibitor, 5 or 50 mg/kg BW/day) for 12 weeks from 6 weeks of age. Then we analyzed lipid and glucose metabolism and tissue inflammation in the liver and adipose tissues along with serum markers in those mice.. Propagermanium treatment slightly decreased body weight gain and visceral fat accumulation in diet-induced obese (DIO) mice. Further, propagermanium suppressed macrophage accumulation and shifted adipose tissue macrophage polarization from the pro-inflammatory (M1) state to anti-inflammatory (M2) state in DIO mice. Expressions of TNF-alpha and MCP-1 mRNA in adipose tissue were reduced by propagermanium treatment, indicating that propagermanim suppressed inflammation in adipose tissue. Propagermanium treatment also ameliorated glucose tolerance, insulin sensitivity, and decreased hepatic triglyceride in DIO mice. Thus, propagermanium improved diet-induced obesity and related metabolic disorders, such as insulin resistance and hepatic steatosis by suppressing inflammation in adipose tissue. Our data indicate that inhibition of CCR2 could improve diet-induced metabolic disorders, and that propagermanium may be a beneficial drug for the treatment of metabolic syndrome.

Topics: Adipose Tissue; Animal Feed; Animals; Body Weight; Fatty Liver; Germanium; Inflammation; Insulin Resistance; Lipids; Male; Mice; Mice, Inbred C57BL; Obesity; Organometallic Compounds; Propionates; Receptors, CCR2; Tumor Necrosis Factor-alpha

Recently, adipose tissue inflammation induced by macrophage infiltration through MCP-1/C-C chemokine receptor-2 (CCR2) pathway is considered to play a role in the development of visceral obesity and insulin resistance. In the present study, to further examine the role of CCR2 in the development of obesity and type 2 diabetes, we studied the effect of pharmacological inhibition of CCR2 from the early stage of obesity in db/db mice.. Db/+m (lean control) and db/db mice were fed with a standard diet with or without 0.005% propagermanium, as a CCR2 inhibitor for 12 weeks from 6 weeks of age. Propagermanium treatment decreased body weight gain, visceral fat accumulation, and the size of adipocytes only in db/db mice. Further, propagermanium suppressed macrophage accumulation and inflammation in adipose tissue. Propagermanium treatment also ameliorated glucose tolerance and insulin sensitivity, and decreased hepatic triglyceride contents in db/db mice.. Propagermanium improved obesity and related metabolic disorders, such as insulin resistance and hepatic steatosis by suppressing inflammation in adipose tissue. Our data indicate that inhibition of CCR2 could improve obesity and type 2 diabetes by interfering adipose tissue inflammation, and that propagermanium may be a beneficial drug for the treatment of the metabolic syndrome.

Topics: Adipose Tissue; Adiposity; Animals; Cell Size; Fatty Liver; Germanium; Insulin Resistance; Liver; Macrophages; Male; Metabolic Syndrome; Mice; Mice, Mutant Strains; Mice, Obese; Obesity; Organometallic Compounds; Propionates; Receptors, CCR2; Triglycerides; Weight Gain