Dong Qing-Yu, Chen Li, Gao Guan-Qi, Wang Lei, Song Jun, Chen Bo, Xu Yu-Xin, Sun Lei
Department of Endocrinology and Metabolism, QiluHospital of Shandong University, No. 107 WenhuaxiRoad, Jinan, Shandong, 250012, PR China.
Clin Invest Med. 2008 Dec 1;31(6):E328-37. doi: 10.25011/cim.v31i6.4918.
Bone marrow-derived mesenchymal stem cells (BM-MSCs) are multipotent stroma cells which can provide a potential therapy for diabetes mellitus. But the mechanism is still controversial. Also, the status of BM-MSCs under hyperglycemia is not known. In the present study, we investigated the status of BM-MSCs in experimental-diabetic rat and demonstrated the rescue of experimental diabetes by diabetic MSCs transplantation.
BM-MSCs were cultured and the potential of multiple-differentiation was identified through induction into osteoblasts. MSCs of passage 3 were used for the following experiment. The MSCs were labeled with 5-bromo-2?-deoxyuridine (BrdU). Diabetes in rats was induced by STZ injection. The rats were divided into three groups: normal control group (no DM, rats treated with saline through tail vein, n=10); DM control group (DM, no transplantation of MSCs, n=20); experimental group (DM and transplantation of MSCs, n=20). Body weight and blood glucose of the rats were monitored during the experiment after transplantation of MSCs. Paraffin sections of pancreas were obtained from rats of each group. Immuno-histochemistry analysis and double immunofluorescence were used to detect the BM-MSCs in the pancreatic tissue and their differentiating state.
MSCs were 89.5% labeled by BrdU and DAPI, which was green/blue double stained under fluorescent microscopy. Transplantation of diabetic MSCs resulted in a reduction of hyperglycemia on day 45 in experimental diabetic rats compared with control rats (17.7 mM +/-3.9 vs 27.8 mM +/- 2.1, P < 0.05), There was also a difference between MSC-treated experimental diabetic rats and control rats in body weight (232.7 g +/-19.7 vs 133.3g +/-13.1, P < 0.05). Histological and morphometric analysis of the pancreas of experimental diabetic rats showed the presence and differentiation of transplanted MSCs into insulin-producing cells which evidenced by double-staining of anti-BrdU and insulin. Also, there were many small islets throughout the sections. Their mean area and diameter analysis revealed that they were smaller than control islets (1835.7 +/- 175.8 microm2 vs 13257.2 +/- 1457.6 microm2; 43.5 +/- 3.7 microm vs 119.9 +/- 5.8 microm, respectively, P < 0.05).
Allogeneic MSCs transplantation can reduce blood glucose level in recipient rats. A relatively small quantity of transplanted diabetic MSCs survive and transdifferentiate into insulin-producing cells in the pancreas of recipient rats. Upon transplantation these cells initiate endogenous pancreatic regeneration by neogenesis of islet of recipient origin. The present study demonstrates that diabetic MSCs retains its stemness and potential to induce pancreatic regeneration on transplantation.
骨髓间充质干细胞（BM-MSCs）是多能基质细胞，可为糖尿病提供潜在的治疗方法。但其机制仍存在争议。此外，高血糖状态下BM-MSCs的情况尚不清楚。在本研究中，我们调查了实验性糖尿病大鼠中BM-MSCs的情况，并证明了糖尿病间充质干细胞移植可挽救实验性糖尿病。
培养BM-MSCs，并通过诱导成骨细胞来鉴定其多向分化潜能。第3代间充质干细胞用于以下实验。用5-溴-2'-脱氧尿苷（BrdU）标记间充质干细胞。通过注射链脲佐菌素（STZ）诱导大鼠患糖尿病。将大鼠分为三组：正常对照组（无糖尿病，经尾静脉注射生理盐水处理的大鼠，n = 10）；糖尿病对照组（糖尿病，未移植间充质干细胞，n = 20）；实验组（糖尿病并移植间充质干细胞，n = 20）。在移植间充质干细胞后的实验过程中监测大鼠的体重和血糖。从每组大鼠获取胰腺石蜡切片。采用免疫组织化学分析和双重免疫荧光检测胰腺组织中的BM-MSCs及其分化状态。
在荧光显微镜下，BrdU和DAPI标记的间充质干细胞呈绿色/蓝色双重染色，标记率为89.5%。与对照组大鼠相比，移植糖尿病间充质干细胞使实验性糖尿病大鼠在第45天时高血糖有所降低（17.7 mM±3.9 vs 27.8 mM±2.1，P < 0.05）。接受间充质干细胞治疗的实验性糖尿病大鼠与对照组大鼠在体重上也存在差异（232.7 g±19.7 vs 133.3 g±13.1，P < 0.05）。对实验性糖尿病大鼠胰腺的组织学和形态计量学分析显示，移植的间充质干细胞存在并分化为产生胰岛素的细胞，抗BrdU和胰岛素的双重染色证明了这一点。此外，整个切片中有许多小胰岛。对其平均面积和直径的分析显示，它们比对照胰岛小（分别为1835.7±175.8平方微米 vs 13257.2±1457.6平方微米；43.5±3.7微米 vs 119.9±5.8微米，P < 0.05）。
同种异体间充质干细胞移植可降低受体大鼠的血糖水平。相对少量移植的糖尿病间充质干细胞在受体大鼠胰腺中存活并转分化为产生胰岛素的细胞。移植后，这些细胞通过受体来源的胰岛新生启动内源性胰腺再生。本研究表明，糖尿病间充质干细胞在移植时保留了其干性和诱导胰腺再生的潜力。
