跨膜蛋白88对缺血-再灌注小鼠心肌纤维化的影响及机制研究

Effect of TMEM88 on myocardial fibrosis in mice with ischemia-reperfusion and its mechanism

目的探讨跨膜蛋白(transmembrane protein 88,TMEM88)对缺血-再灌注小鼠心肌纤维化(myocardial fibrosis,MF)的影响及可能机制研究。方法将36只SPF级C57小鼠随机分为对照组(Control组)、心肌缺血-再灌注模型组(Ischemia reperfusion,I/R组)和心肌缺血-再灌注模型+TMEM88组(I/R+TMEM88组)。采用对左冠状动脉前降支结扎的方法构建缺血-再灌注小鼠模型。利用超声心动图检测各组小鼠心功能;Masson染色检测各组小鼠心脏病理学变化并测定胶原容积分数(Collagen volume fraction,CVF);蛋白免疫印迹(Western blot)法检测β-连环蛋白(β-catenin)、α-平滑肌肌动蛋白(alpha-smooth muscle actin,α-SMA)和E-钙黏蛋白(E-cadherin)的表达情况。结果与Control组比较,I/R组小鼠LVEDD和LVEDV明显增高[LVEDD(mm):3.37±0.25 vs. 4.28±0.56,LVEDV(mm):46.89±8.20 vs. 83.80±22.48],LVFS和LVEF明显降低[(LVFS:(%) 30.33±3.18 vs. 20.71±2.82,LVEF(%):58.77±4.55vs. 42.44±4.80],CVF升高(%:4.06±0.74 vs. 29.54±1.32),β-catenin及α-SMA表达明显增加(β-catenin:0.35±0.17 vs. 0.74±0.14,α-SMA:0.39±0.21 vs. 0.85±0.30),Ecadherin表达减少(0.54±0.16 vs. 0.28±0.10),差异均有统计学意义(P<0.05);与I/R组比较,I/R+TMEM88组小鼠LVEDD和LVEDV减低[LVEDD(mm):4.28±0.56 vs. 3.85±0.29,LVEDV(mm):83.80±22.48 vs. 64.27±11.59],LVFS和LVEF增高[LVFS(%):20.71±2.82vs. 24.14±3.79,LVEF(%):42.44±4.80 vs. 48.53±6.14),CVF降低(%:29.54±1.32 vs.25.06±3.62),β-catenin及α-SMA表达减少(β-catenin:0.74±0.14 vs. 0.58±0.10,α-SMA:0.85±0.30 vs. 0.59±0.11),E-cadherin表达增加(0.28±0.10 vs. 0.41±0.05),差异均有统计学意义(P<0.05)。结论 TMEM88能够通过抑制Wnt/β-catenin信号通路活性改善缺血-再灌注小鼠的心肌纤维化程度。

Objective To explore the effect of transmembrane protein 88( TMEM88) on myocardial fibrosis( MF) in mice with ischemia-reperfusion( I/R) and its possible mechanism.Methods 36 SPF C57 mice were randomly divided into control group,I/R group and I/R + TMEM88 group. Mice models of I/R were constructed by ligating the left anterior descending coronary artery.Ultrasound was used to detect the cardiac function in the mice of each group;Masson staining was used to detect the physical changes in the heart disease and to determine the collagen volume fraction( CVF);Western blot was used to detect β-catenin protein and alpha-smooth muscle actin( α-SMA) and E-cadherin. Results Compared with the control group,the LVEDD and LVEDV of the I/R group weresignificantly increased[LVEDD( mm) : 3. 37 ± 0. 25 vs. 4. 28 ± 0. 56,LVEDV( mm) : 46. 89 ± 8. 20 vs. 83. 80 ± 22. 48],and LVFS and LVEF were significantly reduced[LVFS( %) : 30. 33 ± 3. 18 vs.20. 71 ± 2. 82,LVEF( %) : 58. 77 ± 4. 55 vs. 42. 44 ± 4. 80],the CVF increased( % : 4. 06 ± 0. 74 vs.29. 54 ± 1. 32),the expression of β-catenin and α-SMA were significantly increased( β-catenin:0. 35 ± 0. 17 vs. 0. 74 ± 0. 14,α-SMA: 0. 39 ± 0. 21 vs. 0. 85 ± 0. 30),E-cadherin expression decreased( 0. 54 ± 0. 16 vs. 0. 28 ± 0. 10),the difference was statistically significant( P< 0. 05);Compared with the I/R group,LVEDD and LVEDV in I/R + TMEM88 group decreased[LVEDD( mm) : 4. 28 ± 0. 56 vs. 3. 85 ± 0. 29,LVEDV( mm) : 83. 80 ±22. 48 vs. 64. 27 ±11. 59],and LVFS and LVEF increased[LVFS( %) : 20. 71 ± 2. 82 vs. 24. 14 ± 3. 79,LVEF( %) : 42. 44 ± 4. 80 vs. 48. 53 ±6. 14],CVF decreased( % : 29. 54 ± 1. 32 vs. 25. 06 ± 3. 62),β-catenin and α-SMA expression were reduced( β-catenin: 0. 74 ± 0. 14 vs. 0. 58 ± 0. 10,α-SMA: 0. 85 ± 0. 30 vs. 0. 59 ± 0. 11),E-cadherin expression increased( 0. 28 ± 0. 10 vs. 0. 41 ± 0. 05),the difference was statistically significant( P< 0. 05). Conclusions TMEM88 can improve the myocardial fibrosis of I/R mice by inhibiting the activity of Wnt/β-catenin signaling pathway.