From the Department of Pediatrics and.
Internal Medicine, Children's Hospital of Pittsburgh of the University of Pittsburgh Medical Center and the University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224.
J Biol Chem. 2013 Jul 19;288(29):21065-21073. doi: 10.1074/jbc.M113.471425. Epub 2013 Jun 6.
Biliary pancreatitis is the most common etiology of acute pancreatitis, accounting for 30-60% of cases. A dominant theory for the development of biliary pancreatitis is the reflux of bile into the pancreatic duct and subsequent exposure to pancreatic acinar cells. Bile acids are known to induce aberrant Ca(2+) signals in acinar cells as well as nuclear translocation of NF-κB. In this study, we examined the role of the downstream Ca(2+) target calcineurin on NF-κB translocation. Freshly isolated mouse acinar cells were infected for 24 h with an adenovirus expressing an NF-κB luciferase reporter. The bile acid taurolithocholic acid-3-sulfate caused NF-κB activation at concentrations (500 μm) that were associated with cell injury. We show that the NF-κB inhibitor Bay 11-7082 (1 μm) blocked translocation and injury. Pretreatment with the Ca(2+) chelator 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, the calcineurin inhibitors FK506 and cyclosporine A, or use of acinar cells from calcineurin Aβ-deficient mice each led to reduced NF-κB activation with taurolithocholic acid-3-sulfate. Importantly, these manipulations did not affect LPS-induced NF-κB activation. A critical upstream regulator of NF-κB activation is protein kinase C, which translocates to the membranes of various organelles in the active state. We demonstrate that pharmacologic and genetic inhibition of calcineurin blocks translocation of the PKC-δ isoform. In summary, bile-induced NF-κB activation and acinar cell injury are mediated by calcineurin, and a mechanism for this important early inflammatory response appears to be upstream at the level of PKC translocation.
胆源性胰腺炎是急性胰腺炎最常见的病因，占 30-60%。胆源性胰腺炎发展的一个主要理论是胆汁反流到胰管，然后暴露于胰腺腺泡细胞。胆酸已知会在腺泡细胞中诱导异常的 Ca(2+)信号和 NF-κB 的核转位。在这项研究中，我们研究了下游 Ca(2+)靶标钙调神经磷酸酶在 NF-κB 转位中的作用。新鲜分离的小鼠腺泡细胞用表达 NF-κB 荧光素酶报告基因的腺病毒感染 24 小时。胆酸牛磺胆酸-3-硫酸盐在与细胞损伤相关的浓度（500μm）下引起 NF-κB 激活。我们表明，NF-κB 抑制剂 Bay 11-7082（1μm）阻断了转位和损伤。用 Ca(2+)螯合剂 1,2-双（邻氨基苯氧基）乙烷-N,N,N',N'-四乙酸预处理、钙调神经磷酸酶抑制剂 FK506 和环孢菌素 A 预处理，或使用钙调神经磷酸酶 Aβ 缺陷型小鼠的腺泡细胞，均可导致牛磺胆酸-3-硫酸盐引起的 NF-κB 激活减少。重要的是，这些操作不影响 LPS 诱导的 NF-κB 激活。NF-κB 激活的一个关键上游调节因子是蛋白激酶 C，它在活跃状态下易位到各种细胞器的膜上。我们证明，钙调神经磷酸酶的药理学和遗传抑制阻断了 PKC-δ 同工型的转位。总之，胆汁诱导的 NF-κB 激活和腺泡细胞损伤是由钙调神经磷酸酶介导的，这种重要的早期炎症反应的机制似乎在上游的 PKC 转位水平。
