人脐带间充质干细胞肌肉注射对多柔比星诱导扩张型心肌病大鼠心功能及心肌超微结构的影响

Intramuscular injection of human umbilical cord mesenchymal stem cells and its effect on the cardiac function and myocardial ultrastructure in rats with Adriamycin -induced dilated cardiomyopathy rats

目的探讨人脐带问充质干细胞（hUCMSC）肌肉注射对多柔比星诱导扩张型心肌病（DCM）大鼠心功能及心肌超微结构的影响。方法160只SD大鼠按随机数字表法分为正常组（20只）和DCM组（140只），DCM组每周腹腔注射多柔比星2mg／kg，连续8周，建立DCM大鼠模型。造模成功者采用随机数字表法分为模型对照组（简称模型组）、hUCMSC培养上清液组（简称上清液组）、hUCMSC低剂量组（简称低剂量组）、hUCMSC中剂量组（简称中剂量组）、hUCMSC高剂量组（简称高剂量组）。超声心动图检测心功能，酶联免疫吸附测定检测大鼠血浆脑利钠肽（BNP）和血清心肌肌钙蛋白I（cTnI），光镜和电镜观察大鼠心肌组织超微结构。结果DCM组大鼠出现精神反应差、活动及进食减少、体质量不增或增长缓慢、脱毛及腹水，经肌肉注射hUC-MSC后，低剂量组、中剂量组大鼠上述症状均不同程度好转。肌肉注射hUCMSC前，DCM组大鼠左心室射血分数（LVEF）[（64．53±2．61）％]、左心室短轴缩短分数（LVFS）[（30．80±2．11）％]均显著低于正常组[（79．67±3．02）％、（43．08±3．15）％，P均〈0．01]。肌肉注射hUCMSC后，中、低剂量组LVEF[（75．5±7．4）％、（74．0±6．1）％]及LVFS[（40．8±3．8）％、（40．2±5．0）％]均显著高于模型组[（65．8±4．5）％、（30．2±2．9）％，P均〈0．01]。中、低剂量组血浆BNP[（438．3±82．2）ng／L、（341．7±68．9）ng／L]和血清cTnI水平[（375．9±110．9）ng／L、（355．9±55．6）,g／L]明显低于模型组[（449．9±91．8）ng／L、（425．9±42．6）ng／L，P均〈0．05]。心肌HE染色及透射电镜均显示中、低剂量组大鼠心肌细胞超微结构较模型组改善。结论hUCMSC肌肉注射可显著改善多柔比星诱导DCM大鼠LVEF、LVFS，降低血浆BNP和血清cTnI水平，减轻心肌组织病理损伤及改善心肌细胞超微结构。

Objective To explore the effects of intramuscular injection human umbilical cord mesenchymal stem cells（hUCMSC） intramuscular injection on the cardiac function and myocardial ultrastructure in rats with Adria- mycin - induced dilated cardiomyopathy （DCM） rats. Methods One hundred and sixty rats were randomly divided in- to a normal group （20 cases） and DCM groups （140 cases） ,rats in DCM groups receiving Adriamycin （2 mg/kg） in- traperitoneally once a week for 8 weeks to establish DCM models. The DCM rats were randomly divided into a model control group （ served as model group）, the supernatant of hUCMSC group （ served as supernatant group）, the low - dose hUCMSC group（ served as low- dose group） ,the medial- dose hUCMSC group（ served as medial- dose group）, and the high -dose hUCMSC group（ served as high -dose group）. Echocardiography was performed to evaluate the car- diac function, plasma brain natriuretic peptide （BNP） level and serum cardiac troponin I （cTnI） level were detected by enzyme- linked immunosorbent assay kit ;light microscope and transmission electron microscopy （TEM） were used to observe the ultrastructure of myocardium. Results Rats in the DCM group showed low spirit, declining food intake, progressive emaciation, slow growth, hair loss and ascites. After the intramuscular injection of hUCMSC, the above symp- toms of rats in the low - dose and the medial - dose hUCMSC groups were improved significantly. Before the administra- tion of hUCMSC, the left ventricular ejection fraction （LVEF） [ （64.53 ± 2.61 ）% ] and the left ventricular fractional shortening （LVFS） [ （30.80 ± 2.11 ） % ] were significantly decreased in the DCM group compared to those of the con- trol group[ （79.67 ± 3.02）%, （43.08 ± 3. 15）%, all P 〈 0.01 ]. After the administration of hUCMSC, LVEF [ （75.5 ± 7.4） %, （74.0 ± 6.1 ） % ] and LVFS [ （40.8 ± 3.8 ） %, （40.2 ± 5.0 ） % ] were significantly increased in the low - dose and the medial - dose group compared with those of the model group [ （ 65.8 ± 4.5 ） %, （ 30.2 ± 2. 9） %, all P 〈 0.01 ]. The concentration of plasma BNP level ± （438.3 ± 82.2） ng/L, （ 341.7 ± 68.9 ） ng/L ] and serum cTnI level [ （375.9 ± 110.9） ng/L, （355.9 ± 55.6） ng/L ] were significantly decreased compared with those ofthe model group [ （449.9 ± 91.8） ng/L, （425.9 ± 42.6） ng/L, all P 〈 0.05 ]. The findings of HE staining showed that eardiomyoeytes were orderly arranged, edema decreased and cell nucleus homogeneously stained in the low - dose and the medial - dose group. The outcomes of TEM revealed that the uhrastructure of cardiomyocytes was improved in the low - dose and the medial - dose group compared with that of model group, and the cardiomyocyte sarcolemma re- mained intact, and the swelling of mitoehondria ameliorated and the cristae of mitochondria remained clear. Conclusions Intramuscular injection of hUCMSC could significantly increase LVEF and LVFS in the Adriamycin - induced DCM rats, and decrease the plasma BNP levels and the serum cTnI levels, attenuate the myocardial pathological damage and improve myocardial uhrastructure.