人成肌细胞向神经前体细胞转分化及在大鼠体内移植的研究

目的探讨成人成肌细胞能否转分化为神经前体细胞。方法从6例成人正常颞肌标本中分离培养成肌细胞,培养至第3代时加入含有碱性成纤维细胞生长因子、表皮生长因子和白血病抑制因子的无血清培养液,诱导2周,对诱导细胞进行免疫细胞化学鉴定和逆转录聚合酶链反应(RT-PCR)分析;将诱导细胞和人成肌细胞分别移植到12只脑缺血大鼠脑内,采用免疫组织化学植细胞的存活和分化进行鉴定。结果成肌细胞在经诱导7 d 后开始聚集成球,悬浮生长,该细胞球平均每14 d 传代1次。细胞球均表达巢蛋白,在分化条件下,(36±6)%的细胞表达微管相关蛋白2,(44±5)%的细胞表达胶质纤维酸性蛋白,(17±4)%的细胞表达半乳糖脑苷脂;经诱导细胞移植到大鼠脑内后表达微管相关蛋白2和胶质纤维酸性蛋白。而对照组的成肌细胞则不表达上述标志物。结论人成肌细胞在体外一定诱导条件下能够转分化为神经前体细胞。

Study on trans-differentiation of adult human myoblasts into neural precursor cells and its implantation in rats

Objective To investigate the feasibility of inducing adult human myoblasts into neural precursor cells.Methods The myoblasts were isolated with mixed digestive enzyme from minced human temporal muscle samples,cultured and purified clonally.The 3rd passage cells were incubated with serum free medium including basic fibroblast growth factor(bFGF),epidermal growth factor(EGF)and leukemia inhibitory factor(LIF).Morphological change was investigated during incubation period. Immunofluorescence cytochemistry and RT-PCR analysis were used to assess cell differentiation and transdifferentiation.Results After the induction,cells became non-adherent aggregates as neurospheres. The myoblast-derived neurospheres was immuno-positive for nestin.In differentiation condition,they looked like neurons and glial cells and expressed neuronal(microtubule associated protein 2,MAP-2),astrocytic (Glial fibrillary acidic protein,GFAP)and oligodendrocytic(Galactocerebroside,Galc)markers by immunocytochemistry.The result by RT-PCR was coincident with immunocytochemistry.The myoblast- derived neurospheres expressed MAP-2 and GFAP after they were transplanted into the brain of rats with cerebral ischemia.Conclusion Adult human myoblasts can be inducted to trans-differentiate into neural precursor cells.