目的：探讨Toll样受体3（Toll‐like receptor 3，TLR3）基因缺陷对于四氯化碳诱导的肝纤维化小鼠模型肝纤维化损伤程度的影响。方法：将20只野生型雄性小鼠和20只T L R3基因缺陷型（T L R3‐／‐）雄性小鼠分别分为野生型对照组、野生型造模组、T L R3‐／‐对照组和T L R3‐／‐造模组，每组各10只。对照组腹腔注射玉米油，造模组腹腔注射四氯化碳。造模8周后采集血液标本，应用全自动生化分析仪检测血清丙氨酸氨基转移酶（alanine aminotransferase ，ALT）、天门冬氨酸氨基转移酶（aspar‐tate transaminase ，AST）、总胆红素（total bilirubin ，TBIL）、白蛋白（albumin ，ALB）水平；采用马松三色染色法对肝组织胶原沉积程度进行分析；采用α‐平滑肌肌动蛋白（alpha smooth muscle actin ，α‐SMA）免疫组织化学染色法检测肝星状细胞的激活情况；应用试剂盒检测肝组织中的羟脯氨酸含量；采用实时荧光定量PC R法检测肝组织中纤维化标志物Ⅰ型胶原、炎性因子[包括肿瘤坏死因子‐α（tumor necrosis factor‐α，TNF‐α）、白介素6（interleukin‐6，IL‐6）和单核细胞趋化因子1（monocyte chemotac‐tic protein‐1，MCP‐1）]以及促纤维化分子[包括转化生长因子‐β（transforming growth factor‐β，TGF‐β）、基质金属蛋白酶组织抑制因子1（ tissue inhibitor of metalloproteinase 1，TIMP1）和血小板衍生生长因子受体（platelet‐derived growth factor recep‐tor ，PDGFR）]的表达。结果：TLR3基因缺陷对于四氯化碳诱导的肝纤维化小鼠血清中的ALT、AST、TBIL、ALB水平变化无影响。T L R3基因缺陷可加重四氯化碳诱导的肝组织胶原沉积和肝星状细胞激活；促进四氯化碳诱导的小鼠肝组织中羟脯氨酸的升高；使四氯化碳诱导的肝纤维化标志物Ⅰ型胶原增多，也使肝组织中炎性因子 TNF‐α、IL‐6和 MCP‐1以及促纤维化分子TGF‐β、TIMP1和PDGFR表达升高。结论：TLR3基因缺陷可促进四氯化碳诱导的肝纤维化小鼠肝组织中的胶原沉积和肝星状细胞激活，促进肝组织炎性因子释放，使肝促纤维化分子上调。以上提示，T L R3是肝纤维化病理过程中的一个保护性基因。%Objective:To investigate the effect of Toll‐like receptor 3(TLR3) gene deficiency on the degree of liver fibrosis in mouse model of carbon tetrachloride(CCl4 )‐induced liver fibrosis .Methods :A total of 20 wild‐type male mice and 20 male mice with TLR3 gene deficiency (TLR3‐/‐) were divided into wild‐type control group and wild‐type model group ,TLR3‐/‐ control group and TLR3‐/‐ model group ,respectively ,with 10 mice in each group .The control group was injected with corn‐oil by intraperitoneal injection while the model group was injected with CCl4 by intraperitoneal injection .After 8 weeks ,blood sample wascollectedandserumlevelofalanineaminotransferase(ALT),aspartatetransaminase(AST),totalbilirubin(TBIL),and albumin(Alb) was analyzed by automatic biochemical analyzer .And the degree of collagen deposition in liver tissue was evaluated by Masson trichrome staining .And the activation of hepatic stellate cells was detected by immunohistochemistry staining of α‐smooth muscle actin(α‐SMA).And hydroxyproline content of liver tissue was detected with detection kit . Furthermore ,real‐time fluorescence polymerase chain reaction was used to detect the expression of liver fibrotic marker type I collagen ,and inflammatory cytokines including tumor necrosis factor‐alpha (TNF‐α) , interleukin‐6 (IL‐6 ) and monocyte chemotactic protein‐1(MCP‐1) ,as well as pro‐fibrotic molecule including transforming growth factor‐beta (TGF‐β) ,tissue inhibitor of metalloproteinase 1(TIMP1) and platelet‐derived growth factor receptor(PDGFR) .Results:TLR3 gene deficiency had no effect on CCl4‐induced change regarding serum level of ALT ,AST ,TBIL ,ALB .TLR3 gene deficiency aggregated the CCl4‐induced collagen deposition and hepatic stellate cell activation in liver tissue .And it promoted the CCl4‐induced elevation of hydroxyproline content and expression increase of fibrotic marker type I collagen .Furthermore ,the expression increase of inflammatory cytokines including TNF‐α,IL‐6 and MCP‐1 ,as well as that of pro‐fibrotic molecule including TGF‐β,TIMP1 and PDGFR ,was promoted .Conclusions :TLR3 gene deficiency could promote liver collagen deposition and hepatic stellate cell activation in mouse model of CCl4‐induced liver fibrosis ,and it could promote inflammatory cytokine release and pro‐fibrotic molecule up‐regulation .All above suggest that TLR3 is a protective gene during liver fibrosis pathological process .
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