高良姜素对阻塞性黄疸大鼠肝组织细胞凋亡的影响及机制

Effects and mechanism of galangin on hepatocyte apoptosis in rats with obstructive jaundice

目的基于Janus激酶2(JAK2)/信号转导及转录激活因子3(STAT3)信号通路探究高良姜素(GAL)对阻塞性黄疸(OJ)大鼠肝组织细胞凋亡的影响及机制。方法以雄性SD大鼠为对象,采用胆总管双重结扎法建立OJ模型,并将造模成功的48只大鼠分为OJ模型组(Model组)、低剂量GAL组(GAL-L组)、高剂量GAL组(GAL-H组)、高剂量GAL+JAK2激活剂colivelin组(GAL-H+colivelin组),每组12只;另取只开/关腹部不结扎的SD大鼠12只,作为假手术组(Sham组)。各药物组大鼠灌胃和/或腹腔注射相应药液,每天1次,连续7 d。末次给药后,观察各组大鼠的肝组织病理学形态,检测其血清中总胆红素(TBIL)、直接胆红素(DBIL)、丙氨酸转氨酶(ALT)、γ-谷氨酰转移酶(GGT)水平,肝组织中超氧化物歧化酶(SOD)、丙二醛(MDA)水平,肝组织细胞凋亡率,以及信号通路相关蛋白[磷酸化JAK2、JAK2、磷酸化STAT3、STAT3]、凋亡相关蛋白[B细胞淋巴瘤2(Bcl-2)、Bcl-2相关X蛋白(Bax)]的表达情况。结果与Sham组比较,Model组大鼠肝组织肝窦充血,肝小叶出现损伤,肝细胞排列紊乱、形态肿胀且核仁消失,可见大量炎症细胞浸润和纤维组织增生;血清中TBIL、DBIL、ALT、GGT水平,肝组织中MDA水平,肝组织细胞凋亡率,以及肝组织中Bax蛋白的表达水平和JAK2、STAT3蛋白的磷酸化水平均显著升高(P<0.05);肝组织中SOD水平、Bcl-2蛋白的表达水平均显著降低(P<0.05)。与Model组相比,GAL-L、GAL-H组大鼠肝组织病理损伤均有所减轻,各定量指标均显著改善,且GAL-H组的效果更显著(P<0.05);colivelin可显著逆转GAL对于OJ大鼠肝损伤及相关指标的改善作用(P<0.05)。结论GAL可抑制OJ大鼠肝组织细胞凋亡,改善其肝功能,减轻氧化应激,上述作用可能与抑制JAK2/STAT3信号通路有关。

OBJECTIVE To investigate the effects and mechanism of galangin(GAL)on hepatocyte apoptosis in rats with obstructive jaundice(OJ)based on the Janus kinase 2(JAK2)/signal transduction and activator of transcription 3(STAT3)signaling pathway.METHODS Taking male SD rats as the object,the OJ model was established by double ligation of common bile duct,and 48 rats with successful modeling were randomly separated into OJ model group(model group),low-dose GAL group(GAL-L group),high-dose GAL group(GAL-H group)and high-dose GAL+JAK2 activator colivelin group(GAL-H+colivelin group),with 12 rats in each group;another 12 SD rats with laparotomy/abdominal closure without ligation were selected as sham operation group(sham group).Each administration group was given relevant medicine intragastrically and/or intraperitoneally,once a day,for 7 consecutive days.After the last medication,the morphology of liver tissue in rats was observed;the serum levels of total bilirubin(TBIL),direct bilirubin(DBIL),alanine transaminase(ALT)andγ-glutamyltransferase(GGT),as well as the levels of superoxide dismutase(SOD)and malondialdehyde(MDA)in liver tissue were detected.The apoptotic rate of liver tissue cells,the expression levels of signaling pathway-related proteins(phosphorylated JAK2,JAK2,phosphorylated STAT3,STAT3)and apoptosis-related proteins[B cell lymphoma 2(Bcl-2),Bcl-2 related X protein(Bax)]were determined.RESULTS Compared with sham group,congestion of liver sinusoids,damage to liver lobules,disordered arrangement and swollen morphology of liver cells,the disappearance of nucleoli,and significant infiltration of inflammatory cells and fibrous tissue proliferation were observed in model group;the serum levels of TBIL,DBIL,ALT and GGT,the level of MDA in liver tissue,the apoptosis rate of liver cells,the protein expression of Bax,and the protein phosphorylation levels of JAK2 and STAT3 in liver tissue of model group were increased significantly(P<0.05);the level of SOD and the protein expression of Bcl-2 in liver tissue were decreased significantly(P<0.05).Compared with the model group,the pathological injuries of liver tissue were relieved in GAL-L group and GAL-H group,all quantitative indicators had significantly improved,and the effect of GAL-H group was more significant(P<0.05).Colivelin could significantly reverse the improvement effects of GAL on liver injury and related indicators of OJ rats(P<0.05).CONCLUSIONS GAL may inhibit liver cell apoptosis in OJ rats,improve liver function and alleviate oxidant stress,the mechanism of which may be associated with inhibiting JAK2/STAT3 signaling pathway.