2017 Volume 40 Issue 5 Pages 638-644
Pioglitazone improves sepsis-induced organ injury accompanied with anti-inflammatory effects on visceral adipose tissue. However, its action in adipose immune cells remains to be ascertained. We investigated the effects of pioglitazone on visceral adipose macrophage population and polarisation in cecal ligation and puncture (CLP)-induced sepsis mice. Eight-week-old male mice were assigned to 3 groups: 1) sham-operated group, 2) CLP group, or 3) pioglitazone-treated CLP group. Pioglitazone (10 mg/kg) was injected intraperitonally for 7 d and CLP surgery was performed. Visceral adipose tissues were collected 24 h after the surgery. mRNA expression of several macrophage markers (inducible nitric oxide synthase (iNOS) for M1, arginase1 (Arg1) and interleukin (IL)-10 for M2, CD163 and F4/80 for mature macrophages) and inflammatory adipokines (IL-6, monocyte chemoattractant protein-1: MCP-1) was quantified by real-time RT-PCR. Tissue sections were subjected to the immunohistochemical analysis and the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay. CLP significantly enhanced Arg1, IL-10 and iNOS mRNA expressions as compared with the sham group, and pioglitazone significantly increased the mRNA level of CD163 and F4/80 in CLP mice. Expression of IL-6 and MCP-1 stimulated by CLP was reduced by pioglitazone treatment. Increased CD11b/c- and CD163-positive cells as well as apoptotic cells were observed in the CLP group and the pioglitazone-treated group. The data indicate that M1/M2 macrophage activation of visceral adipose tissues is induced in CLP-induced mice, and the function of macrophages recruited from surrounding organs may be modulated by pioglitazone treatment.
