Therapeutic effect and potential mechanism of pioglitazone in rats with severe acute pancreatitis

Caspase recruitment domain-containing protein 9 (Card9) is located upstream of the nuclear factor kappa B (NF-κB) and p38 mitogen-activated protein kinase (MAPK) inflammatory pathways. This study investigated the therapeutic effect and potential mechanism of pioglitazone in rats with severe acute pancreatitis (SAP). SAP was induced by a retrograde infusion of 5.0% sodium taurocholate into the biliopancreatic duct of Sprague Dawley rats (n=54), which were then treated with pioglitazone. Blood and pancreatic tissues were harvested at 3, 6, and 12 h after SAP induction. Pancreatic pathological damage was evaluated by hematoxylin and eosin staining. Serum amylase, serum pro-inflammatory cytokines, and pancreatic myeloperoxidase (MPO) activities were determined by enzyme-linked immunosorbent assay. The expression of Card9 mRNA and protein in pancreatic tissues was detected by real-time polymerase chain reaction and western blotting. Pioglitazone had a therapeutic effect in treating rats with SAP by decreasing the level of amylase activity, ameliorating pancreatic histological damage, decreasing serum pro-inflammatory cytokine levels and tissue MPO activity, and downregulating the expression of NF-κB, p38MAPK, and Card9 mRNAs and proteins (P<0.05). The present study demonstrated that the inhibition of Card9 expression could reduce the severity of SAP. Card9 has a role in the pathogenic mechanism of SAP.

含半胱天冬酶募集结构域蛋白9（Caspase recruitment domain-containing protein 9, Card9）定位于核因子κB（nuclear factor kappa B, NF-κB）与p38丝裂原活化蛋白激酶（mitogen-activated protein kinase, MAPK）炎症通路的上游。本研究旨在探讨吡格列酮（pioglitazone）对重症急性胰腺炎（severe acute pancreatitis, SAP）大鼠的治疗作用及其潜在分子机制。实验通过向54只Sprague Dawley大鼠的胆胰管逆行灌注5.0%牛磺胆酸钠构建SAP模型，随后给予吡格列酮干预。于SAP造模后3 h、6 h及12 h采集外周血与胰腺组织样本。采用苏木精-伊红染色法评估胰腺组织的病理损伤程度；通过酶联免疫吸附试验检测血清淀粉酶、血清促炎细胞因子水平及胰腺髓过氧化物酶（myeloperoxidase, MPO）活性；采用实时聚合酶链反应（real-time polymerase chain reaction）与蛋白质印迹法（western blotting）检测胰腺组织中Card9 mRNA及蛋白的表达水平。结果显示，吡格列酮可通过降低血清淀粉酶活性、减轻胰腺组织学损伤、下调血清促炎细胞因子水平与组织MPO活性，同时抑制NF-κB、p38MAPK及Card9的mRNA与蛋白表达，从而对SAP大鼠发挥治疗作用（P<0.05）。本研究证实，抑制Card9表达可减轻SAP的病情严重程度，提示Card9在SAP的发病机制中发挥关键作用。