心肌梗死后移植骨髓间充质干细胞后全身细胞的分布

Cell body distribution after bone marrow mesenchymal stem cells intramyocardial injection into a rat myocardial infarction model

目的观察经心肌梗死边缘区移植骨髓间充质干细胞（MSCs）24h和2周后的全身分布。方法雄性SD大鼠的MSCs用溴脱氧尿苷（BrdU）标记。将雌性SD大鼠经心梗3周后随机分为2组。第1组为标记细胞（3×10^6，50μl）经心肌注入心梗边缘区（n=12）。第2组为等体积的磷酸盐缓冲液（PBS）经心肌注入心梗边缘区（n=8）。移植细胞24h及2周后，体内细胞的分布情况通过实时定量逆转录一聚合酶链反应（RT—PCR）检测及病理切片免疫组织化学染色来评价。结果细胞经心梗边缘区移植后可以分布在心脏以及心外脏器脾脏、肺脏和肝脏中。移植24h后细胞主要在心脏中分布（467467±191387），其他脏器中的分布较少，而在2周后移植细胞在包括心脏（112388±43751）在内的各个脏器中的分布都很少，病理切片免疫组织化学染色结果显示与RT-PCR结果相符。结论MSCs经心梗边缘区移植后主要在心脏中分布，同时脾脏、肺脏、肝脏中也有分布，但其分布数量随着移植时间锐减。

Objective To study the systemic distribution of bone marrow derived mesenchymal stem cells （MSCs） 24 h and 2 weeks after cell injection into the border zone of myocardial infarction area. Methods MSCs from male SD rats were labeled with Bromodeoxyuridine （BrdU）. Three weeks after induction of myocardial infarction, female SD rats were randomized into 2 groups. Labeled ceils （3 × 106 ,50 V,1） were injected into the border zone of infarcted area in the one group （n = 12） ,and PBS of equal vol- ume was injected into the border zone of infarcted area in the other group （ n = 8）. The systemic distribution of MSCs was evaluated through real-time PCR and immunohistochemistry at time points of 24 h and 2 weeks after injection, respectively. Results Cells injected into border zone of infarcted area were distributed to extra-cardiac organs such as spleen, lung and liver. Twenty-four h after injection, cells mainly concentrated in the heart （467 467 ± 191 387） ,while obvious cell loss was noted in all organs including the heart （112 388 ±43 751 ） 2 weeks after injection. Of immunostaining were consistent with those of real- time PCR. Conclusion After injected into the border zone of infarcted area, MSCs mainly gathered in the heart with distributions into spleen, lung, and liver. However, substantial number of cells lost with prolonged time span.