CAJ | 학술논문

目的观察微炎症致脂质稳态失调在载脂蛋白E基因敲除(apolipoprotein E knockout,ApoE-/-)小鼠心肌纤维化中的作用,并探讨内皮-间充质转化(endothelial-mesenchymal transition,End-MT)在其中的作用机制.方法 24只ApoE-/-小鼠分为对照组(普通饮食,n=8),高脂组(高脂饮食,n=8)和高脂炎症组(高脂饮食,且每日背部皮下注射10％酪蛋白0.5 ml,n=8).干预8周后处死小鼠,检测血清脂质谱及炎症标志物淀粉样蛋白A(serum amloid A,SAA)水平；采用苏木素伊红染色观察心脏内血管泡沫细胞的形成；Masson染色观察心肌纤维化情况；免疫组织化学、免疫荧光染色及Western blot检测End-MT相关蛋白表达水平,如CD31、胶原Ⅰ、α-平滑肌肌动蛋白(α-smooth muscle actin,α-SMA).结果高脂炎症组小鼠SAA水平明显高于对照组和高脂组[(127.42±26.99) ng/ml比(15.40±7.62) ng/ml和(8.17 ±0.72) ng/ml,P值分别为0.003和0.002],而高脂炎症组血清甘油三酯(TG)、总胆固醇(TC)及低密度脂蛋白胆固醇(LDL-C)水平却均明显低于高脂组[TG值为(3.43±0.79) mmol/L比(7.53 ±2.05) mmol/L;TC值为(14.94±1.92) mmol/L比(27.80±3.99) mmol/L;LDL-C值为(9.46±1.31)mmol/L比(11.56±2.56) mmol/L,P均＜0.05].苏木素伊红染色及Masson染色显示,与对照组和高脂组相比,高脂炎症组小鼠心脏内血管有更多泡沫细胞形成,且心肌纤维化程度更重.免疫组织化学及Western blot结果显示,高脂炎症组胶原Ⅰ,α-SMA表达水平均较对照组和高脂组高(P均＜ 0.001),而CD31表达水平则均较对照组和高脂组低(P均＜0.05).结论微炎症致脂质稳态失调在ApoE-/-小鼠心肌纤维化过程中发挥着重要作用,其机制可能与诱导End-MT发生有关.
목적 관찰미염증치지질은태실조재재지단백E기인고제(apolipoprotein E knockout,ApoE-/-)소서심기섬유화중적작용,병탐토내피-간충질전화(endothelial-mesenchymal transition,End-MT)재기중적작용궤제.방법 24지ApoE-/-소서분위대조조(보통음식,n=8),고지조(고지음식,n=8)화고지염증조(고지음식,차매일배부피하주사10％락단백0.5 ml,n=8).간예8주후처사소서,검측혈청지질보급염증표지물정분양단백A(serum amloid A,SAA)수평；채용소목소이홍염색관찰심장내혈관포말세포적형성；Masson염색관찰심기섬유화정황；면역조직화학、면역형광염색급Western blot검측End-MT상관단백표체수평,여CD31、효원Ⅰ、α-평활기기동단백(α-smooth muscle actin,α-SMA).결과 고지염증조소서SAA수평명현고우대조조화고지조[(127.42±26.99) ng/ml비(15.40±7.62) ng/ml화(8.17 ±0.72) ng/ml,P치분별위0.003화0.002],이고지염증조혈청감유삼지(TG)、총담고순(TC)급저밀도지단백담고순(LDL-C)수평각균명현저우고지조[TG치위(3.43±0.79) mmol/L비(7.53 ±2.05) mmol/L;TC치위(14.94±1.92) mmol/L비(27.80±3.99) mmol/L;LDL-C치위(9.46±1.31)mmol/L비(11.56±2.56) mmol/L,P균＜0.05].소목소이홍염색급Masson염색현시,여대조조화고지조상비,고지염증조소서심장내혈관유경다포말세포형성,차심기섬유화정도경중.면역조직화학급Western blot결과현시,고지염증조효원Ⅰ,α-SMA표체수평균교대조조화고지조고(P균＜ 0.001),이CD31표체수평칙균교대조조화고지조저(P균＜0.05).결론 미염증치지질은태실조재ApoE-/-소서심기섬유화과정중발휘착중요작용,기궤제가능여유도End-MT발생유관.
Objective Dyslipidemia and chronic inflammation are risk factors of cardiac fibrosis.This study was aimed to investigate their possible synergetic effects and underlying mechanisms on progression of cardiac fibrosis in apolipoprotein E knockout (ApoE-/-) mice.Methods Twenty-four ApoE-/-mice were divided into normal chow diet (control),high fat diet (HFD group),and HFD plus subcutaneously injection of 10％ casein (inflammation group) for 8 weeks.Lipid profile and serum amyloid A (SAA) were examined by clinical biochemical assays and Enzyme-Linked Immunosorbent Assay,respectively.Hematoxylin-eosin staining (HE) and Masson staining were used to evaluate the myocardial accumulation of lipid and collagen.Collagen Ⅰ protein expression was detected by immunohistochemical staining.Endothelial-to-mesenchymal transition related protein expressions were determined by Western blot.Results Serum SAA level was significantly higher in inflammation group [(127.42 ± 26.99) ng/ml] than in control [(15.40 ± 7.62) ng/ml] and HFD [(8.17 ± 0.72) ng/ml] group (all P ＜ 0.01).However serum levels of triglyceride,total cholesterol,and low density lipoprotein (LDL) cholesterol were significantly higher in HFD group than in inflammation and control groups[TG (7.53 ± 2.05) mmol/L vs.(3.43 ± 0.79) mmol/L ; TC (27.80 ± 3.99) mmoL/L vs.(14.94 ± 1.92) mmol/L ; LDL-C (11.56 ±2.56) mmol/L vs.(9.46 ± 1.31) mmol/L,all P ＜ 0.05).Foam cell formation in cardiac vessels.myocardial collagen deposit,protein expressions of collagen Ⅰ,CD31,and alpha-smooth muscle actin (α-SMA) were all significantly higher in inflammation group than in HFD group (all P ＜ 0.05) suggesting that inflammation contributes to the phenotype endothelial-to-mesenchymal transition in heart.Conclusion Inflammation exacerbates dyslipidemia mediated cardiac fibrosis in ApoE-/-mice partly through enhancing myocardial endothelial-to-mesenchymal transition.