Pancreatic protease activation by alcohol metabolite depends on Ca2+ release via acid store IP3 receptors
Pancreatic protease activation by alcohol metabolite depends on Ca2+ release via acid store IP3 receptors
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DOI：
10.1073/pnas.0904818106
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发表时间：
2009-06-30
影响因子：
11.1
通讯作者：
Petersen, Ole H.
中科院分区：
文献类型：
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作者：
Gerasimenko, Julia V.;Lur, Gyoergy;Petersen, Ole H.
毒性酒精对胰腺腺泡细胞的影响，引起通常致命的人类疾病急性胰腺炎，主要是由脂肪酸乙酯（酒精和脂肪酸的非氧化产物）介导的，使体内Ca2+储存空化。由于细胞内胰蛋白酶激活，这种过量的Ca2+释放诱导Ca2+依赖性坏死。我们的目的是确定与致命的细胞内蛋白酶激活相关的Ca2+释放的特定来源。在双光子渗透的小鼠胰腺腺泡细胞中，我们监测了在素敏感的内质网（ER）和巴非霉素敏感的酸室中Ca2+浓度的变化，这些细胞只位于顶端颗粒极。我们还评估了顶端颗粒区域的胰蛋白酶活性。棕榈油酸乙酯（POAEE）可诱导内质网和酸池中Ca2+的释放，但胰蛋白酶的激活主要依赖于酸池中Ca2+的释放，这主要由2型和3型功能性肌醇1,4,5-三磷酸受体（IP(3)Rs）介导。当2型和3型的IP(3)Rs被敲除时，POAEE引起了很少的Ca2+释放和胰蛋白酶激活。针对2型和3型的IP(3)Rs抗体，而不是1型抗体，显著抑制poaee诱导的Ca2+释放和胰蛋白酶激活。我们得出结论，Ca2+通过酸颗粒Ca2+储存中2型和3型的IP(3)Rs释放诱导细胞内蛋白酶激活，并提出这是酒精相关性急性胰腺炎发病的关键过程。
Toxic alcohol effects on pancreatic acinar cells, causing the often fatal human disease acute pancreatitis, are principally mediated by fatty acid ethyl esters (non-oxidative products of alcohol and fatty acids), emptying internal stores of Ca2+. This excessive Ca2+ liberation induces Ca2+-dependent necrosis due to intracellular trypsin activation. Our aim was to identify the specific source of the Ca2+ release linked to the fatal intracellular protease activation. In 2-photon permeabilized mouse pancreatic acinar cells, we monitored changes in the Ca2+ concentration in the thapsigargin-sensitive endoplasmic reticulum (ER) as well as in a bafilomycin-sensitive acid compartment, localized exclusively in the apical granular pole. We also assessed trypsin activity in the apical granular region. Palmitoleic acid ethyl ester (POAEE) elicited Ca2+ release from both the ER as well as the acid pool, but trypsin activation depended predominantly on Ca2+ release from the acid pool, that was mainly mediated by functional inositol 1,4,5-trisphosphate receptors (IP(3)Rs) of types 2 and 3. POAEE evoked very little Ca2+ release and trypsin activation when IP(3)Rs of both types 2 and 3 were knocked out. Antibodies against IP(3)Rs of types 2 and 3, but not type 1, markedly inhibited POAEE-elicited Ca2+ release and trypsin activation. We conclude that Ca2+ release through IP(3)Rs of types 2 and 3 in the acid granular Ca2+ store induces intracellular protease activation, and propose that this is a critical process in the initiation of alcohol-related acute pancreatitis.