同种异体骨髓间充质干细胞在急性坏死性胰腺炎大鼠中的迁移和分化

Migration and differentiation of intravenously transplanted bone marrow mesenchymal stem cells in rats with acute necrotizing pancreatitis

目的观察同种异体来源的骨髓问充质干细胞（bone marrow mesenchymal stem cells，MSCs）在急性坏死性胰腺炎（ANP）大鼠中的迁移及分化状况。方法分离、纯化雄性SD大鼠的骨髓MSCs。按数字表法将雌性SD大鼠分为正常移植组、ANP移植组和ANP组，每组10只。采用腹腔注射L-精氨酸方法制备ANP模型。24h后2个移植组大鼠经尾静脉输注MSCs。移植后72h处死大鼠，取胰腺及心脏、肝脏、肾脏组织标本。胰腺组织常规病理检奋并评分，采用原位杂交方法检测各组织Y染色体雄性鉴别基因sry片段的存在。结果分离的MSCs在培养3～5d内快速分裂增殖，形成集落，传代培养至第3代，CD29^＋CD44^＋CD45^-细胞群达到95％以上。ANP组大鼠胰腺组织大片坏死，大量炎细胞浸润，病理分值为（10．31±0．85）分，显著高于ANP移植组的（7．30±0．79）分（P〈0．05）。移植组大鼠的心脏、肝脏、胰腺、肾脏均可检测到sty基因。正常移植组胰腺组织可见散在分布的sry阳性细胞；ANP移植组胰腺组织可见较多sry阳性细胞，且多聚集于损伤较严重的部位。结论炎性损伤的胰腺组织可能具有招募MSCs的能力，并能减轻大鼠胰腺局部的炎症反应。

Objective To observe whether the intravenously transplanted homologous bone marrow mesenchymal stem cells （MSCs） can migrate to the impaired pancreas tissue in the rats with acute necrotizing pancreatitis （ANP）. Methods MSCs were isolated fiom bone marrow of male Sprague-Dawley （SD） rats and adhered to the culture plate in vitro. Female rats were divided randomly into 3 groups： normal transplantation group, ANP transplantation group, ANP group with 10 rats in each group. ANP was induced by intraperitoneal injections with L-arginine. Both transplantation group received MSCs infusion through tail vein. 72 h later, the rats were sacrificed, the pancreas, heart, liver and kidney tissues were harvested, and the morphological changes were examined and scored, the characteristics of migration of MSCs to pancreas were detected with the expression of sry gene of Y chromosome by using chromogenic in situ hybridization （CISH）. Results Rapid proliferation occurred in isolated MSCs after culture for 3 - 5 days and colonies were formed. After 3 generations, CD29^＋ CD44^＋ CD45^- cells accounted for over 95% of all the cells. There ware massive tissue necrosis, inflammatory cells infiltration in the pancreas of ANP group, the pathological score was 10.31± 0.85, which were significantly higher than that in ANP transplantation group （7.30 ± 0.79, P 〈 0.05）. Sty gene eouht be detected in the pancreas, heart, liver and kidney tissues. In addition, scattered distributed sty positive ceils were observed in the normally transplanted pancreatic tissue, lots of sry positive cells were observed in the ANP transplanted pancreatic tissue, and they were located in the most injured areas. Conclusions The intlammatory pancreatic tissue has the ability of recruiting MSCs in vivo, which can alleviate local inflammation.