Secretion of Adipocytes and Macrophages under Conditions of Inflammation and/or Insulin Resistance and Effect of Adipocytes on Preadipocytes under These Conditions

The purpose of the present study was to examine changes in preadipocytes following the coculture of preadipocytes and adipocytes and the effects on the secretion of adipocytes and macrophages following induction of inflammation and insulin resistance. Mature adipocytes and RAW264.7 macrophages were treated with lipopolysaccharide and insulin to establish models of inflammation and insulin resistance, respectively. The mRNA expression levels of IL-6, MCP-1, and TNF-alpha in all adipocyte treatment groups were significantly greater compared with the control, and that of adiponectin was less (P < 0.05). In the RAW264.7 macrophages, the mRNA expression levels of IL-6 and TNF-alpha were greater than those in the control group (P < 0.05). Moreover, the results of this study confirmed that adipocytes and macrophages increased the secretion of inflammatory factors under conditions of induced inflammation and insulin resistance. In addition, 3T3-L1 adipocytes inhibited the proliferation and differentiation of preadipocytes when cocultured with adipocytes under conditions of inflammation and/or insulin resistance, and the phenotype of preadipocytes did not change.