骨髓间充质干细胞对大鼠结直肠放射性损伤的防护作用

The protective effect of bone marrow mesenchymal stem cells on colorectal radiation injury in rats

目的探讨骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)移植对大鼠结直肠组织放射性损伤的修复作用及其可能机制。方法36只健康SD大鼠,随机分为空白对照组、γ射线照射组、BMSCs治疗组。γ射线照射组及BMSCs治疗组予12Gy的60Coγ射线一次性全腹照射,BMSCs治疗组照射后第2d尾静脉注射大鼠骨髓间充质干细胞注射液1ml(1×106个/ml)。3组大鼠均于实验第7d经心脏采血后处死并留取结直肠标本,采用HE染色法观察黏膜组织病理形态变化;TUNEL法检测黏膜细胞的凋亡情况;ELISA法测定外周血TNF-α和IL-10含量。结果HE染色示γ射线照射组大鼠结直肠肠黏膜形态和结构发生明显病理损伤改变;BMSCs治疗组较γ射线照射组病理受损程度减轻。γ射线照射组大鼠结直肠肠黏膜细胞凋亡率较空白对照组显著升高,BMSCs治疗组则显著低于γ射线照射组。γ射线照射组大鼠外周血中TNF-α含量较空白对照组显著升高,IL-10升高无统计学差异;BMSCs治疗组TNF-α低于γ射线照射,IL-10含量显著高于γ射线照射组。结论BMSCs移植可减轻结直肠粘膜的放射性病理性损伤,并可通过抑制细胞凋亡减轻大鼠放射性结直肠损伤,通过抑制炎症反应减轻大鼠放射性结直肠损伤。

Objective To explore the repairing effect of bone marrow mesenchymal stem cells(BMSCs)transplantation on radiation injury of colorectal tissue in rats and its possible mechanism.Methods 36 healthy SD rats were randomly divided into control group,γ-ray irradiation group and BMSCs treatment group.The abdomen of rats in theγ-ray irradiation group and the BMSCs treatment group was irradiated with 12 Gy 60 Coγ-ray once.The BMSCs treatment group was injected with 1 ml of rat bone marrow mesenchymal stem cell(1×106 cells/ml)via tail vein on the second day after irradiation.All three groups of rats were collected blood through the heart on the 7 th day of the experiment,and were sacrificed to dissect and collect colorectal specimens.HE staining method was used to observe the pathological change of colorectal mucosa.TUNEL method was used to detect the apoptosis of colorectal mucosa cells.The content of TNF-αand IL-10 in peripheral blood were measured by ELISA.Results It was observed by HE staining that the morphology and structure of colorectal and intestinal mucosa of rats inγ-irradiation group had obvious pathological changes,and the degree of that pathological damage in BMSCs treatment group was alleviated inγ-ray irradiation group.The rate of apoptosis of colorectal intestinal mucosa cells in theγ-ray irradiation group was significantly higher than that in the control group,while the BMSCs treatment significantly reversed that irradiation-caused cell apoptosis increase.The TNF-αcontent in the peripheral blood of rats in theγ-ray irradiation group was obviously higher than that in the control group,and there was no statistical difference in the increase of IL-10;the TNF-αin the peripheral blood of rats in the BMSCs treatment group was significantly lower than that inγ-ray irradiation,and the content of IL-10 was markedly higher than that inγ-ray irradiation group.Conclusion BMSCs transplantation can alleviate the pathological injury caused by irradiation in colorectal mucosa by inhibiting apoptosis and inflammatory reaction.