紧密连接蛋白2缺失对小鼠胆汁及胆固醇结石形成的影响分析  

Effect of tight junction protein 2 deficiency on the formation of bile and cholesterol stones in mice

作　　者：陈跃 冯亚东[2] 赵向阳 Chen Yue;Feng Ya-dong;Zhao Xiang-yang(Department of Gastroenterology,Lishui People’s Hospital/Zhongda Hospital Lishui Branch,Southeast University,Nanjing 211200,Jiangsu,China;Department of Gastroenterology,Zhongda Hospital,Southeast University,Nanjing 210009,Jiangsu,China)

机构地区：[1]南京市溧水区人民医院/东南大学附属中大医院溧水分院消化科,江苏南京211200 [2]东南大学附属中大医院消化科,江苏南京210009

出　　处：《肝胆胰外科杂志》2020年第4期227-231,共5页Journal of Hepatopancreatobiliary Surgery

基　　金：南京市卫生科技发展专项资金项目(YKK18215)。

摘　　要：目的旨在探究紧密连接蛋白2(Cldn2)在胆汁分泌中的相关作用。方法实验将受试小鼠分为Cldn2^^-/-基因敲除组(Cldn2^-/-组)与Cldn2^+/+野生型组(Cldn2^+/+组),进行4周致石饮食,两组小鼠分别获得肝脏及胆管组织,通过组织学、生物化学、电生理学分析等分析两组小鼠肝脏和胆管内水及相关离子渗透压梯度运动差异;评价两组小鼠胆结石的形成情况。结果Cldn2^+/+组小鼠的胆汁流速为[(58.0±4.4)μL/(min·kg)],约为Cldn2^-/-组[29.0±3.3μL/(min·kg)]的2倍,Cldn2^-/-组胆汁中总胆固醇、磷脂、总胆汁酸及总胆红素均显著高于Cldn2^+/+组(P<0.01)。当将Cldn2^+/+组的肝内胆管单位(IBDU)置于低渗缓冲液中时,腔内空间立即增加且持续至90 s;相反,当IBDU置于高渗缓冲液中时,Cldn2^+/+组腔内空间立即降低并且持续收缩至90 s;Cldn2^-/-组具有相同的趋势,但变化幅度显著低于Cldn2^+/+组,表现为90 s低渗时[(1.20±0.02)%vs(1.34±0.02)%,P=0.035],高渗时[(0.67±0.01)%vs(0.82±0.01)%,P=0.025]。与Cldn2^+/+组比,Cldn2^-/-组Na+浓度降低,但K+浓度升高,跨上皮电传导速度显著降低。致石饮食后所有Cldn2^-/-组肉眼均可见明显的胆结石形成,结石的主要成分是胆固醇(>98%),而Cldn^+/+组中仅1只小鼠有结石形成。结论Cldn2可能通过调控胆汁中的水分、胆固醇含量以及离子浓度,进而影响胆汁流速和成分,该蛋白的缺失会导致胆固醇结石发生的风险增加。Objective To explore the role of tight junction protein 2(Cldn2)in bile secretion.Methods Experimental mice were divided into two groups:Cldn2^-/-knockout group(Cldn2^-/-group)and Cldn2^+/+wild type group(Cldn2^+/+group).After 4 weeks of lithogenic diet,liver and bile duct tissues in two groups were obtained.Histological,biochemical and electrophysiological analysis were used to observe the difference of osmotic pressure gradient movement of water and related ions in hepatocytes and bile ducts,and to evaluate the formation of gallstones in two groups.Results The bile flow rate in Cldn2^+/+group was[(58.0±4.4)μL/(min·kg)]twice as much as that in Cldn2^-/-group[29.0±3.3μL/(min·kg)],the bile total cholesterol,phospholipid,total bile acid and total bilirubin in Cldn2^-/-group were significantly higher than those in Cldn2^+/+group(P<0.01).When IBDU in Cldn2^+/+group was placed in hypotonic buffer,the lumen space increased immediately and lasted for 90 s;on the contrary,when IBDU was placed in hypertonic buffer,the intracavitary space in Cldn2^+/+group decreased immediately and continuous contraction lasted for 90 s in Cldn2^+/+group,but the change was significantly lower than that in Cldn2^+/+group,with[(1.20±0.02)vs(1.34±0.02),P=0.035]at hypotonic buffer and[(0.67±0.01)%vs(0.82±0.01)%,P=0.025]at hypertonic buffer.The concentration of Na+decreased and the concertration of K+increased in Cldn2^-/-group than those in Cldn2^+/+group,and transepithelial electrical conduction velocity decreased.After lithogenic diet,obvious gallstone formation was visible to the naked eye in all Cldn2^-/-groups,and the main component of gallstone was cholesterol(>98%);while only 1 in Cldn2^+/+group had gallstone formation.Conclusion Cldn2-deficiency affects the bile composition and fluidity by regulating the content of water,cholesterol and ion concentration in bile,and then affecting the flow rate and composition of bile by regulating cholesterol and water flow in the way of paracrine.This process will increase the risk of chole

关 键 词：紧密连接蛋白2 胆汁流动 胆结石 胆固醇 小鼠 

分 类 号：R575.6[医药卫生—消化系统]