Background: Obesity is a risk factor for acute pancreatitis (AP), but the molecular mechanism remains unclear. Adiponectin, an adipose tissue-derived secretory factor, has anti-inflammatory properties in addition to various biological functions, and its plasma concentrations are reduced in obese subjects. However, the role of adiponectin in AP has not been investigated.
Aim: To determine the effects of adiponectin on AP.
Methods: We investigated the effects of adiponectin on experimental AP by using adiponectin-knockout (APN-KO) mice and adenovirus-mediated adiponectin overexpression. AP was induced by 10 hourly intraperitoneal injections of low-dose caerulein (10 μg/kg) after 2-week feeding of normal chow or high-fat diet (HFD) in wild-type (WT) and APN-KO mice. We evaluated the severity of AP biochemically and morphologically.
Results: Low-dose caerulein treatment did not induce pancreatic damage, in both WT and APN-KO mice under normal chow feeding. APN-KO mice, but not WT mice, fed HFD then treated with caerulein developed pancreatic damage and inflammation, accompanied by increased macrophage/neutrophil infiltration and upregulation of pro-inflammatory mediators such as tumor necrosis factor-α in the pancreas. Adenovirus-mediated overexpression of adiponectin attenuated the severity of HFD/caerulein-induced AP in APN-KO mice.
Conclusions: Adiponectin plays a protective role in caerulein-induced AP in HFD-fed mice.