急性胰腺炎中胰腺腺泡细胞信号转导通路

急性胰腺炎(acute pancreatitis,AP)是一种炎症反应所致的胰腺腺泡细胞损伤、间质水肿和出血,并可导致局部和全身并发症.各种因素如胆结石、酒精、局部缺血、遗传等似乎都首先影响胰腺腺泡细胞,引起胰腺腺泡细胞胰酶活化,诱发局部炎症反应[1].AP发病机制中胰腺腺泡细胞受到多种细胞因子调控,这些细胞因子通过结合细胞表面受体,激活细胞内不同的信号转导通路,使胰腺腺泡细胞的功能结构发生变化.     

急性胰腺炎腺泡细胞钙超载发病机制及其研究方法

急性胰腺炎（acute pancreatitis，AP）病势凶险且缺乏特异性治疗手段，主要原因在于其发病机制尚未完全阐明。在AP的诸个发病环节中，腺泡细胞内酶原异常激活引起自身消化是AP早期的主要病理事件。追溯触发酶原异常激活的机制，“胰腺腺泡细胞钙超载学说”是目前研究的热点并得到越来越广泛的认同。多学科研究技术相结合在该学说研究领域的应用正方兴未艾。本文拟对AP腺泡细胞钙超载发病机制及其研究方法作一综述。     

细胞凋亡与急性胰腺炎关系的研究进展

急性胰腺炎（acute pancreatitis，AP）是一种常见的急腹症，近年来发病率有所上升。大部分患是轻症胰腺炎，但约有25％的患发展成为重症急性胰腺炎（severe acute pancreatitis，SAP），并伴发全身炎症反应综合征（SIRS）和多器官衰竭（MOF），死亡率达30％～50％。AP的最早期病理变化为胰腺腺泡细胞损伤。随后炎症介质和炎性细胞浸润。AP病情的严重程度与腺泡细胞凋亡密切相关。本就胰腺腺泡细胞凋亡及其调控基因与AP的相互关系做一综述。     

X连锁凋亡抑制蛋白和Smac在大鼠急性胰腺炎腺泡细胞中的表达

近年研究发现,胰腺腺泡细胞不同的死亡方式对急性胰腺炎(AP)病情轻重起着重要作用,AP的严重程度与腺泡细胞凋亡密切相关.     

细胞凋亡与急性胰腺炎关系的研究进展

急性胰腺炎(acute pancreatitis, AP)是一种常见的急腹症,近年来发病率有所上升[1].大部分患者是轻症胰腺炎,但约有25%的患者发展成为重症急性胰腺炎(severe acute pancreatitis, SAP),并伴发全身炎症反应综合征(SIRS)和多器官衰竭(MOF),死亡率达30% ～ 50%[2,3].AP的最早期病理变化为胰腺腺泡细胞损伤,随后炎症介质和炎性细胞浸润.AP病情的严重程度与腺泡细胞凋亡密切相关.     

急性胰腺炎中的损伤相关分子模式

急性胰腺炎(acute pancreatitis,AP)是多种病因引起胰酶激活,以胰腺局部炎症反应为主要特征,伴或不伴有其他器官功能改变的疾病[1].其初始阶段的局部炎症反应已被证实了是由胰腺腺泡细胞的损伤及坏死介导的[2].细胞损伤后释放的物质被称为损伤相关分子模式(Damage associated molecular pattern,DAMPs).近年来越来越多的证据证明坏死的胰腺腺泡细胞释放的DAMPs介导的炎症反应是决定胰腺损伤及疾病严重程度的关键因素[3].本文就急性胰腺炎中的DAMPs作一综述.     

酒精性胰腺炎——胆碱能的致病假说

对酒精性胰腺炎的发病机制了解尚不多。用雨蛙素过度刺激所致实验性急性胰腺炎的研究促使人们假设:在胰腺外分泌控制起变化后,腺泡细胞胞浆内的消化酶被激活。腺泡细胞对分泌刺激反应的变化,在酒精性胰腺炎发病机制的作用业已受到重视,但有关酒精所致胰腺     

内质网应激与胰腺腺泡细胞损伤

内质网（endoplasmic reticulum,ER）是真核细胞中负责蛋白质合成、折叠修饰和质量监控的重要细胞器.任何扰乱ER稳态的因素如氧化应激、Ca2＋紊乱、病毒感染等都可导致ER处于蛋白折叠的高负荷状态,引发内质网应激（ERS）,激活多条下游信号通路,促进细胞生存;但如果应激反应过于强烈或持久时,ERS则引起细胞损伤甚至死亡[1].胰腺腺泡细胞损伤被认为是胰腺疾病如胰腺炎和胰腺癌的起始发病环节,是目前胰腺疾病研究的中心环节之一.新近的研究报道,在细胞生物学水平上,ERS是引起腺泡细胞受损的最经典最主要的应激机制之一,ERS的过度激活很可能与胰腺组织的多种病理表现相关[2].本文在综合近年文献报道的基础上,针对ERS及下游信号通路与胰腺腺泡细胞损伤及相关疾病如胰腺炎、胰腺癌的关系作一简要阐述.     

趋化因子在实验性急性胰腺炎早期发病机制中的作用

目的　探讨中性粒细胞趋化因子(CINC)和单核细胞趋化蛋白(MCP-1/JE)在急性胰腺炎(AP)早期发病机制中的作用。方法　分别以浓度为0.5%和5%的牛磺胆酸钠逆行胆胰管注射制备大鼠急性水肿型胰腺炎(AEP)和急性坏死型胰腺炎(ANP)模型,同时设假手术对照组,检测血清淀粉酶、生化指标、观察胰腺组织湿干重比、髓过氧化物酶(MPO)活性和病理学改变,检测胰腺组织中 CINC及MCP-1/JE基因和蛋白表达。结果　与假手术对照组阴性表达相比,造模各组胰腺腺泡细胞内均有强弱不等的CINC和MCP-1/JE蛋白表达,胰腺组织MPO活性和CINC mRNA、MCP-1/JE mRNA表达均随AP逐渐加重及时间进展呈不断上调趋势(P< 0. 05 或 P< 0. 01),且 CINC mRNA、MCP-1/JEmRNA的表达都与胰腺组织病理学改变呈正相关。结论　AP 发生早期,胰腺腺泡细胞为 CINC 和MCP-1/JE的来源之一,在AP早期发病机制中发挥重要作用。     

奥曲肽和柴芍承气溻、丹参液治疗重症胰腺炎的作用机制

重症胰腺炎的发病机制十分复杂,包括胰酶和腺泡细胞溶酶体酶的释放：血管通透性的增加和胰腺微循环障碍：巨噬细胞和中性粒细胞的过度刺激释放很多细胞因子、炎症介质和自由基,这些因素相互作用造成胰腺腺泡损伤和肠上皮屏障功能失调,如不及时纠正可导致肠管屏障功能损害、肠菌     

Tubular complexes in cerulein- and oleic acid-induced pancreatitis in rats: glycoconjugate pattern, immunocytochemical, and ultrastructural findings

Ductlike tubular complexes in cerulein-induced pancreatitis and oleic acid-induced pancreatic insufficiency were studied to analyze further their origin and development. Immunocytochemistry for pancreatic enzymes, lectin-binding studies, and ultrastructural investigations were combined with autoradiographic quantitation of labeling indices of ductlike cells in tubular complexes. In one group of rats, pancreatitis was induced by infusion of cerulein (10 micrograms kg-1 h-1). In a second group, pancreatic insufficiency was induced by intraductal injection of oleic acid (50 microliters). The investigations were carried out at distinct intervals following induction of pancreatic injury. In both groups of animals, after 3 days, a significant widening of acinar lumina was paralleled by a decreasing height of acinar cells, which showed pronounced retrogressive changes. At this time, acinar cells bound all of the lectins used and retained their immunoreactivity for amylase, trypsinogen, chymotrypsinogen, and lipase. At further intervals, acinar structures formed typical ductlike complexes, with a progressive loss of immunoreactivity for pancreatic enzymes and a reduced lectin-binding for L-fucose and N-acetylgalactosamine. Autoradiographic quantitation demonstrated no significant labeling of acinar cells undergoing tubular dedifferentiation. In both models, tubular complexes were removed by macrophages. It is concluded that lining cells in tubular complexes represent degenerating acinar cells that have no regenerative potency and have lost their secretory and membrane characteristics.     

Severe acute pancreatitis and reduced acinar cell apoptosis in the exocrine pancreas of mice deficient for the Cx32 gene

BACKGROUND & AIMS: The early events leading to acinar cell injury during acute pancreatitis are poorly characterized. Signaling through gap junction channels contributes to the homeostasis of the exocrine pancreas by coordinating acinar cell activity within an acinus. To explore the role of gap junctional communication in acinar cell response to injury, we analyzed the course of acute pancreatitis induced by injection of cerulein in mice deficient for Cx32, the major gap junction protein expressed in the exocrine pancreas. METHODS: The severity of pancreatitis was evidenced by measuring serum amylase activity, pancreatic edema, acinar cell necrosis, pancreatic tumor necrosis factor alpha concentration, and myeloperoxidase activity. Acinar cell apoptosis was detected by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL), caspase-3 activity, and Bax/Bcl-2 expression. Expression and function of connexin were evaluated by immunofluorescence and dye coupling. RESULTS: Cx32-deficient mice exhibited a deleterious course of acute pancreatitis with increased necrosis, edema, and inflammation of the exocrine pancreas. In addition, the exocrine pancreas of Cx32-deficient mice showed a decreased number of TUNEL-positive acinar cells and decreased caspase-3 activity but no change in Bax or Bcl-2 pancreatic expression. Interestingly, chemicals known to induce apoptosis in vivo had no effect on Cx32-deficient pancreatic acinar cells. CONCLUSIONS: Deficiency of a pancreatic connexin converts a mild reversible form of acute pancreatitis into a severe disease and decreases the sensitivity of acinar cells to apoptotic stimuli. The results show that acinar cell-to-cell communication plays a key role in the modulation of severity of acute pancreatitis.     

Molecular mechanisms of alcoholic pancreatitis

Alcoholic pancreatitis is a major complication of alcohol abuse. Since only a minority of alcoholics develop pancreatitis, there has been a keen interest in identifying the factors that may confer individual susceptibility to the disease. Numerous possibilities have been evaluated including diet, drinking patterns and a range of inherited factors. However, at the present time, no susceptibility factor has been unequivocally identified. In contrast, considerable progress has been made with respect to the constant effects of alcohol on the pancreas. The molecular mechanisms of alcohol-induced pancreatic injury are being increasingly defined with an emphasis, in recent years, on the acinar cell itself as the principal site on ethanol-related damage. It has now been established that the acinar cell is capable of metabolizing alcohol and that the direct toxic effects of alcohol and/or its metabolites on acinar cells may predispose the gland to autodigestive injury in the presence of an appropriate triggering factor. A significant recent development relates to the characterization of pancreatic stellate cells, increasingly implicated in alcoholic pancreatic fibrosis. Here the current concepts regarding the mechanisms/pathways mediating alcohol-induced pancreatic injury are outlined.     

Amino acid transporters expression in acinar cells is changed during acute pancreatitis

Pancreatic acinar cells accumulate amino acids against a marked concentration gradient to synthesize digestive enzymes. Thus, the function of acinar cells depends on amino acid uptake mediated by active transport. Despite the importance of this process, pancreatic amino acid transporter expression and cellular localization is still unclear. We screened mouse pancreas for the expression of genes encoding amino acid transporters. We showed that the most highly expressed transporters, namely sodium dependent SNAT3 (Slc38a3) and SNAT5 (Slc38a5) and sodium independent neutral amino acids transporters LAT1 (Slc7a5) and LAT2 (Slc7a8), are expressed in the basolateral membrane of acinar cells. SNAT3 and SNAT5, LAT1 and LAT2 are expressed in acinar cells. Additional evidence that these transporters are expressed in mature acinar cells was gained using acinar cell culture and acute pancreatitis models. In the acute phase of pancreatic injury, when acinar cell loss occurs, and in an acinar cell culture model, which mimics changes occurring during pancreatitis, SNAT3 and SNAT5 are strongly down-regulated. LAT1 and LAT2 were down-regulated only in the in vitro model. At protein level, SNAT3 and SNAT5 expression was also reduced during pancreatitis. Expression of other amino acid transporters was also modified in both models of pancreatitis. The subset of transporters with differential expression patterns during acute pancreatitis might be involved in the injury/regeneration phases. Further expression, localization and functional studies will follow to better understand changes occurring during acute pancreatitis. These findings provide insight into pancreatic amino acid transport in healthy pancreas and during acute pancreatitis injury.     

塞来昔布对大鼠胰腺腺泡细胞炎症损伤的作用

背景：急性胰腺炎（AP）的发病始于胰腺腺泡细胞内胰酶的激活,造成腺泡细胞损伤。环氧合酶-2（COX-2）和核因子-κB（NF．KB）在AP的炎症反应中起重要作用。目的：观察雨蛙肽和选择性COX-2抑制剂塞来昔布对离体大鼠胰腺腺泡细胞COX-2和NF—κB表达的影响．探讨塞来昔布对腺泡细胞炎症损伤的作用。方法：分离大鼠胰腺腺泡细胞,分为对照组、雨蛙肽组（1×10^-7mol／L）和塞来昔布干预组（100μmol／L,15min后加入雨蛙肽）,分别培养1、3、6、12h。测定腺泡细胞活力、淀粉酶分泌率和乳酸脱氢酶（LDH）漏出率,逆转录聚合酶链反应（RT-PCR）和免疫细胞化学染色检测COX-2、NF—κBmRNA和蛋白表达。结果：与对照组相比,雨蛙肽组各时间点腺泡细胞活力均显著降低,淀粉酶分泌率和LDH漏出率显著增高,COX-2和NF—κBmRNA表达量显著增高,蛋白表达阳性率亦增加（P〈0．05）。塞来昔布干预组各时间点腺泡细胞活力、淀粉酶分泌率和LDH漏出率均较雨蛙肽组显著改善（心O．05）,COX-2mRNA和蛋白表达显著降低（P〈0．05）,NF—κBmRNA和蛋白表达与雨蛙肽组无明显差异。结论：塞来昔布可抑制大鼠胰腺腺泡细胞中雨蛙肽刺激的COX-2活性,从而减轻细胞炎症损伤。     

Primary Culture of Pancreatic (Human) Acinar Cells

The acinar cell culture plays a very important role in research of pancreatic pathophysiology. The aim of this study was to establish a long-term culture of human (foetal) pancreatic acinar cells in standardized nutrient media with supplements. Acinar cells were prepared from pancreatic tissues obtained from aborted foetus (> or =35 weeks) with no prior pancreatic complications by collagenase digestion and cultured using different media and supplements. The purity and phenotype of acinar cells was confirmed by various staining techniques and FACS. The acinar cell proliferation was determined at different time intervals by Bromo-deoxyuridine (BrdU) incorporation, and metabolic enzyme activity was analysed. The acini could be cultured and maintained in Ham's F-12 K/M199 media in the presence of 5% BSA, 0.1 mg/ml STI, 10 ng/ml EGF, and 10% FCS with the same morphological appearance as that of freshly prepared for 12 days with maximum viability of 80-85% and formation of monolayer without extracellular matrix. A significant BrdU incorporation of acinar cells in primary culture was observed which was maximum (105%) at day four. Higher amylase and lipase activity was seen in freshly isolated acinar cells which decreased with time of the culture. The established human pancreatic acinar cell culture may act as an excellent model to study exocrine dysfunction or pancreatitis in response to acinar cell injury.     

Early proteome analysis of rat pancreatic acinar AR42J cells treated with taurolithocholic acid 3-sulfate

BackgroundBile acids are the initiating factors of biliary acute pancreatitis. Bile acids can induce the activation of intracellular zymogen, thus leading injury in pancreatic acinar cells. Pathological zymogen activation in pancreatic acinar cells is a common feature of all types of acute pancreatitis. The proteins expressed in pancreatic acinar cells during the activation of zymogen may determine the severity of acute pancreatitis. The present study aims to determine the differentially expressed proteins in taurolithocholic acid 3-sulfate-stimulated pancreatic acinar cells as an in vitro model for acute pancreatitis.MethodsRat pancreatic acinar AR42J cells were treated with taurolithocholic acid 3-sulfate for 20 min. Laser confocal scanning microscopy and flow cytometry were used to detect activated trypsinogen in pancreatic acinar AR42J cells. After the determination of trypsinogen activation, proteome analysis was performed to identify the proteins differentially expressed in taurolithocholic acid 3-sulfate-treated cells and non-treated cells.ResultsAfter treatment with taurolithocholic acid 3-sulfate for 20 min, the activation of trypsinogen in AR42J cells was concurrent with changes in the protein expression profile. Thirty-nine differentially expressed proteins were detected; among these, 23 proteins were up-regulated and 16 proteins were down-regulated. KEGG analysis indicated that these proteins are involved in cellular metabolic pathways, cellular defensive mechanisms, intracellular calcium regulation and cytoskeletal changes.ConclusionThe expression of proteins in the pancreatic acinar cell changes at the early stage of biliary acute pancreatitis. These differentially expressed proteins will provide valuable information to understand the pathophysiologic mechanism biliary acute pancreatitis and may be useful for prognostic indices of acute pancreatitis.     

Effect of Tetrandrine on LPS-induced NF-κB activation in isolated pancreatic acinar cells of rat

AIM: To investigate the effect of Tetrandrine (Tet) on LPS-induced NF-κB activation and cell injury in pancreatic acinar cells and to explore the mechanism of Tetrandrine preventing LPS-induced acinar cell injury.METHODS: Male rat pancreatic acinar cells were isolated by collagenase digestion, then exposed to LPS (10mg/L), Tet (50 μmol/L, 100 μmol/L) or normal media. At different time point (30 min, 1 h, 4 h, 10 h) after treatment with the agents, cell viability was determined by MTT, the product and nuclear translocation of subunit p65 of NF-κB was visualized by immunofluorescence staining and nuclear protein was extracted to perform EMSA which was used to assay the NF-κB binding activity.RESULTS: LPS induced cell damage directly in a time dependent manner and Tet attenuated LPS-induced cell damage (50 μmol/L, P ＜ 0.05; 100 μmol/L, P ＜ 0.01).NF-κB p65 immunofluorescence staining in cytoplasm increased and began showing its nuclear translocation within 30 min and the peak was shown at 1 h of LPS 10 mg/L treatment. NF-κB DNA binding activity showed the same alteration pattern as p65 immunofluorescence staining. In Tet group, the immunofluorescence staining in cytoplasm and nuclear translocation of NF-κB were inhibited significantly.CONCLUSION: NF-κB activation is an important early event that may contribute to inflammatory responses and cell injury in pancreatic acinar cells. Tet possesses the protective effect on LPS-induced acinar cell injury by inhibiting NF-κB activation.     

Effect of Tetrandrine on LPS-induced NF-κB activation in isolated pancreatic acinar cells of rat

AIM: To investigate the effect of Tetrandrine (Tet) on LPS-induced NF-kappaB activation and cell injury in pancreatic acinar cells and to explore the mechanism of Tetrandrine preventing LPS-induced acinar cell injury. METHODS: Male rat pancreatic acinar cells were isolated by collagenase digestion, then exposed to LPS (10 mg/L), Tet (50 micromol/L, 100 micromol/L) or normal media. At different time point (30 min, 1 h, 4 h, 10 h) after treatment with the agents, cell viability was determined by MTT, the product and nuclear translocation of subunit p65 of NF-kappaB was visualized by immunofluorescence staining and nuclear protein was extracted to perform EMSA which was used to assay the NF-kappaB binding activity. RESULTS: LPS induced cell damage directly in a time dependent manner and Tet attenuated LPS-induced cell damage (50 micromol/L, P < 0.05; 100 micromol/L, P < 0.01). NF-kappaB p65 immunofluorescence staining in cytoplasm increased and began showing its nuclear translocation within 30 min and the peak was shown at 1 h of LPS 10 mg/L treatment. NF-kappaB DNA binding activity showed the same alteration pattern as p65 immunofluorescence staining. In Tet group, the immunofluorescence staining in cytoplasm and nuclear translocation of NF-kappaB were inhibited significantly. CONCLUSION: NF-kappaB activation is an important early event that may contribute to inflammatory responses and cell injury in pancreatic acinar cells. Tet possesses the protective effect on LPS-induced acinar cell injury by inhibiting NF-kappaB activation.