维生素C提高体外培养的去分化脂肪细胞心肌分化效率

目的:采用维生素C处理体外培养的去分化脂肪(dedifferentiated fat,DFAT)细胞,以期进一步提高DFAT细胞的心肌分化效率。方法:用天花板贴壁培养法使大鼠成熟脂肪细胞去分化为DFAT细胞,并体外培养增殖至第3代,然后在培养基中添加维生素C或(和)乳鼠心脏细胞裂解液诱导DFAT细胞心肌分化。3周后,用倒置相差显微镜观察DFAT细胞的形态变化,用real-time PCR、免疫荧光和Western blot检测DFAT细胞的心肌特异性标志物c Tn T、GATA-4及NKx2.5 mRNA和蛋白的表达。结果:大鼠脂肪细胞经天花板贴壁培养后形态转变为成纤维细胞样的DFAT细胞。DFAT细胞在普通培养条件下可自发表达少量心肌特异性标志物。经乳鼠心脏细胞裂解液诱导后,DFAT细胞体积增大、变长,可见肌管样结构,c Tn T、GATA-4及NKx2.5 mRNA和蛋白的表达水平较普通培养的DFAT细胞显著升高。在维生素C的作用下,DFAT细胞c Tn T、GATA-4及NKx2.5的表达水平进一步升高。未观察到自发性搏动细胞。结论:维生素C可促进DFAT细胞分化为心肌样细胞。

Vitamin C enhanced myocardial differentiation of dedifferentiated fat cells

AIM: In order to observe the myocardial differentiation capacity of the dedifferentiated fat (DFAT) cells treated with vitamin C in vitro. METHODS: DFAT cells were dedifferentiated from the mature rat adipocytes with ceiling adherent culture. The DFAT cells of passage 3 were used in the study. Vitamin C and/or neonatal rat heart tissue lysate were added into the culture medium to induce myocardial differentiation for 3 weeks. The cell morphology was observed under microscope. The myocardial-specific markers, such as cTnT, GATA-4 and NKx2.5, were examined by the methods of immunofluorescence, PCR and Western blot. RESULTS: Mature rat adipocytes dedifferentiated into fibroblast-like DFAT cells after ceiling adherent culture. The DFAT cells spontaneously differentiated into cardiomyocyte-like cells under normal culture condition with a low incidence. After treated with neonatal rat heart cell lysate, the DFAT cells became cardiomyocyte-like cells that had bigger size, longer shape and myotubule-structure. The expression of cTnT, GATA-4 and NKx2.5 was remarkably increased at both mRNA and protein levels as compared with the normal cultured DFAT cells. The expression of cTnT, GATA-4 and NKx2.5 was further increased in DFAT cells after treating with vitamin C. No spontaneous beating cell was observed. CONCLUSION: Vitamin C enhances the differentiation of DFAT cells into cardiomyocyte-like cells.