【摘要】 目的探讨人脐带间充质干细胞(MSC)对中重度脂肪肝供肝肝移植大鼠的保护作用。方法给予Lewis大鼠高脂饲料饮食建立中重度脂肪肝模型。采用改良的Kamad"a二袖套法"进行大鼠原位肝移植。供体为中重度脂肪肝的Lewis大鼠,受体为近交系Brown Norway大鼠。32只肝移植大鼠按随机数字表法随机分为MSC组和对照组,各16只。MSC组肝移植术后立即从阴茎背静脉注射含2×106个MSC的生理盐水1.5 ml,对照组从阴茎背静脉注射生理盐水1.5 ml。分别于术后1、3 d两组各取4只大鼠处死,同时留取血清和移植肝组织标本。观察两组血清丙氨酸转氨酶(ALT)、总胆红素(TB)的水平,移植肝组织丙二醛(MDA)、肿瘤坏死因子(TNF)-α含量;病理学检查观察移植肝组织损伤情况;并观察其余大鼠术后存活情况。两组实验数据比较采用t检验。两组大鼠生存分析和比较采用Kaplan-Meier法和Log-rank检验。结果 MSC组和对照组术后1 d的血清ALT水平分别为(501±42)、(619±73)U/L,差异有统计学意义(t=-2.890,P<0.05)。MSC组和对照组术后3 d的血清ALT水平分别为(385±65)、(1190±118)U/L,差异有统计学意义(t=-11.980,P<0.05)。MSC组和对照组术后1 d的TB水平分别为(31±8)、(32±6)μmol/L,差异无统计学意义(t=-2.410,P>0.05);MSC组和对照组术后3 d的TB水平分别为(51±9)、(91±14)μmol/L,差异有统计学意义(t=-4.807,P<0.05)。MSC组和对照组术后1 d的移植肝组织MDA含量分别为(4.9±0.8)、(7.4±0.8)mmol/mg,差异有统计学意义(t=-4.415,P<0.05)。MSC组和对照组术后3 d的移植肝组织MDA含量分别为(3.8±0.6)、(7.9±0.9)mmol/mg,差异有统计学意义(t=-7.597;P<0.05)。MSC组和对照组术后1 d的移植肝组织TNF-α含量分别为(1.04±0.18)、(1.61±0.21)ng/L,差异有统计学意义(t=-4.203,P<0.05)。MSC组和对照组术后3 d的移植肝组织TNF-α含量分别为(0.87±0.06)、(1.92±0.22)ng/L,差异有统计学意义(t=-9.561,P<0.05)。术后1、3 d,对照组移植肝组织可见大量白细胞浸润,肝小叶结构紊乱,肝窦淤血,而MSC组局部反应较轻,组织形态改变明显轻于对照组。MSC组6只大鼠(6/8)存活>1周;对照组仅有1只大鼠(1/8)存活>1周,两组大鼠术后的累积生存率比较,差异有统计学意义(χ2=6.703,P<0.05)。结论人脐带MSC对中重度脂肪肝供肝肝移植大鼠具有保护作用。更多还原

【Abstract】 Objective To investigate the protective effect of human umbilical cord mesenchymal stem cell(MSC) on liver transplant rats with moderate or severe donor fatty livers. Methods Lewis rats were given high fat diets to established models of moderate or severe fatty livers, and orthotopic liver transplantation(LT) was performed on rats using modified Kamada ′s two-cuff technique. The donors were Lewis rats with moderate or severe fatty liver and the recipients were inbred strain Brown Norway rats. Thirty-two LT rats were randomly divided into two groups according to the random number table: MSC group(n=16) and control group(n=16). The rats in MSC group were injected with 1.5 ml normal saline containing 2 ×106MSCs through penile dorsal veins immediately after LT, while the rats in control group were only injected with 1.5 ml normal saline through penile dorsal veins. Four rats from each group were put to death respectively on day 1 and day 3 after operation, and the samples of serum and grafted liver tissues were collected. The levels of serum alanine aminotransferase(ALT), total bilirubin(TB) and the contents of malondialdehyde(MDA), tumor necrosis factor(TNF)- α in grafted liver tissues of two groups were observed. The damage of grafted liver tissues was observed through pathological examination. The postoperative survival of the other rats was also observed. Experimental data between two groups were compared by t test. Survival analysis and comparision of rats between two groups were performed by Kaplan-Meier method and Log-rank test. Results The level of serum ALT on day 1 after operation was(501±42)U/L in MSC group, and was(619±73)U/L in control group, there was significant difference between them(t=-2.890, P<0.05). The level of serum ALT on day 3 after operation was(385±65)U/L in MSC group, and was(1190±118)U/L in control group, there was significant difference between them(t=-11.980, P<0.05). The level of TB on day 1 after operation was(31±8)μmol/L in MSC group, and was(32±6)μmol/L in control group, there was no significant difference between them( t=-2.410, P>0.05). The level of TB on day 3 after operation was(51±9)μmol/L in MSC group, and was(91 ±14)μmol/L in control group, there was significant difference between them(t=-4.807, P<0.05). The content of MDA in grafted liver tissues on day 1 after operation was(4.9±0.8)mmol/mg in MSC group, and was(7.4 ±0.8)mmol/mg in control group, there was significant difference between them(t=-4.415, P<0.05). The content of MDA in grafted liver tissues on day 3 after operation was(3.8 ±0.6)mmol/mg in MSC group, and was(7.9 ±0.9)mmol/mg in control group, there was significant difference between them(t=-7.597, P<0.05). The content of TNF-α in grafted liver tissues on day 1 after operation was(1.04±0.18)ng/L in MSC group, and was(1.61±0.21)ng/L in control group, there was significant difference between them(t=-4.203, P<0.05). The content of TNF-α in grafted liver tissues on day 3 after operation was(0.87±0.06)ng/L in MSC group, and was(1.92±0.22)ng/L in control group, there was significant difference between them(t=-9.561, P<0.05). On day 1, 3 after operation, a large number of leukocyte infiltration, disorder of hepatic lobule structure, hepatic sinusoid congestion were observed in grafted liver tissues of control group, while milder local response was observed in MSC group. The histologic changes in MSC group was evidently milder than that in control group. There were 6 rats(6/8) survived for over 1 week in MSC group while only 1 rat(1/8) in control group. There was significant difference in the cumulative survival rates after operation between rats of two groups( χ2=6.703, P<0.05). Conclusion Human umbilical cord MSC plays a role in the protection of liver transplant rats with moderate or severe donor fatty livers.更多还原