Adiponectin deficiency is associated with severe polymicrobial sepsis, high inflammatory cytokine levels, and high mortality.

BACKGROUND

Adiponectin, a key substance in metabolic syndrome, is known to have anti-inflammatory properties. The relationship between adiponectin and sepsis in vivo is unclear. In this study, the possible involvement of adiponectin in polymicrobial sepsis was investigated using adiponectin-knockout (APN-KO) mice that underwent cecal ligation and puncture (CLP) and received the peroxisome proliferator-activated receptor gamma (PPAR-gamma) that increases the plasma adiponectin concentration.

METHODS

APN-KO and wild-type (WT) mice underwent either CLP or a sham operation. The plasma adiponectin, endotoxin, tumor necrosis factor-alpha (TNF-alpha), and interleukin-6 (IL-6) levels were determined before and at 2, 4, 6, 8, 12, 16, and 24 hours after the procedures, and the survival rates were compared. Mice were injected with rosiglitazone, a selective PPAR-gamma agonist, and compared survival rates after CLP with those without rosiglitazone.

RESULTS

After CLP, APN-KO mice had a significantly higher mortality than WT mice. The plasma endotoxin, TNF-alpha, and IL-6 levels in APN-KO mice were significantly higher than those in WT mice 24 hours after CLP. Within 4 hours after CLP, the plasma adiponectin level in WT mice decreased to half of the initial levels. Pre-CLP treatment with PPAR-gamma was shown to increase the plasma adiponectin level and to improve significantly mortality of WT mice during sepsis; mortality among APN-KO mice did not improve.

CONCLUSION

These results suggest that adiponectin deficiency may cause the high mortality and the high inflammatory cytokine levels in mice with polymicrobial sepsis.