CD34+细胞在干细胞旁分泌下向内皮细胞分化的研究

目的 探讨人脐血CD34+细胞在脐带间充质干细胞(UC-MSCs)旁分泌作用下向内皮细胞诱导分化的可行性.方法 收集20份脐血,体积(103.80±19.77)ml.免疫磁珠(MACS)分选CD34+细胞;取脐带用消化贴壁法获得UC-MSC.流式鉴定干细胞表型.实验分单纯培养组、诱导组、共培养组.结果 流式鉴定CD34+细胞纯度(95.02±3.81)%.培养14 d流式检测共培养组表达CD31、CD144、VWF分别为(65.43±5.61)%、(54.40±4.13)%、(47.53±3.96)%(与单纯培养组比较P＜0.05),部分表达CD34,阴性表达CD45,这与诱导组及成熟脐静脉内皮细胞表达率一致.结论 UC-MSCs旁分泌作用与外源性细胞因子都具有促分化作用,均能使脐血CD34+细胞向内皮细胞分化.

Abstract：

Objective To study whether the paracrine action of umbilical cord-derived mesenchymal stem cells (UC-MSC) can induce differentiation of human umbilical cord blood-derived CD34+ cells into endothelial cells in vitro. Methods The 20 fresh umbilical cord blood samples were collected with volume of (103. 80 ± 19. 77) ml. CD34+ cells were isolated from the mononuclear cells by magnetic activated cell sorting system (MACS) , and mesenchymal stem cells (MSCs) were isolated from umbilical cord by collagenase and trypsin digestion. Three groups were set up: CD34+ cells pure culture group, cytokineinduced group and two stem cells co-culture group with noncontact. Results The average purity of enriched CD34+ cells as assessed by FACS was (95. 02 ± 3. 81) %. Freshly isolated CD34+ cells were small and round which suspended in culture medium. Attached cord-like structure cells of CD34+ cells appeared after 7 days coculture with noncontacted MSC, and when the CD34+ cells grew into large number, they formed colonies. These cells expressed endothelial specific markers, including CD144 (54. 40 ±4. 13)% ,vWF (47. 53 ± 3. 96) % , CD31 (65. 43 ± 5. 61) % ( P ＜ 0. 05, as compared with CD34+ cells pure culture group) , partially expressed CD34 and, the leukocyte common antigen CD45 was negatively expressed.Conclusion Human umbilical cord blood-derived CD34+ cells could be induced into endothelial cells under the paracrine action of umbilical cord-derive mesenchymal stem cells which has the same effect of cytokines.

Paracrine action of umbilical cord-derived mesenchymal stem cells inducing differentiation of human umbilical cord blood-derived CD34+ cells into endothelial cells in vitro

Objective To study whether the paracrine action of umbilical cord-derived mesenchymal stem cells (UC-MSC) can induce differentiation of human umbilical cord blood-derived CD34+ cells into endothelial cells in vitro. Methods The 20 fresh umbilical cord blood samples were collected with volume of (103. 80 ± 19. 77) ml. CD34+ cells were isolated from the mononuclear cells by magnetic activated cell sorting system (MACS) , and mesenchymal stem cells (MSCs) were isolated from umbilical cord by collagenase and trypsin digestion. Three groups were set up: CD34+ cells pure culture group, cytokineinduced group and two stem cells co-culture group with noncontact. Results The average purity of enriched CD34+ cells as assessed by FACS was (95. 02 ± 3. 81) %. Freshly isolated CD34+ cells were small and round which suspended in culture medium. Attached cord-like structure cells of CD34+ cells appeared after 7 days coculture with noncontacted MSC, and when the CD34+ cells grew into large number, they formed colonies. These cells expressed endothelial specific markers, including CD144 (54. 40 ±4. 13)% ,vWF (47. 53 ± 3. 96) % , CD31 (65. 43 ± 5. 61) % ( P ＜ 0. 05, as compared with CD34+ cells pure culture group) , partially expressed CD34 and, the leukocyte common antigen CD45 was negatively expressed.Conclusion Human umbilical cord blood-derived CD34+ cells could be induced into endothelial cells under the paracrine action of umbilical cord-derive mesenchymal stem cells which has the same effect of cytokines.