胰岛素样生长因子-1对共培养的神经细胞和施万细胞超微结构的影响

Effect of insulin like growth factor-1 on ultratructure of co-cultured nerve cell and Schwann cell

目的分析胰岛素样生长因子-1(insulin-like growth factor-1,IGF-1)对体外培养的神经细胞和施万细胞超微结构的影响。方法建立VSC4.1大鼠神经细胞与RSC96大鼠施万细胞共培养模型:将VSC4.1神经细胞与RSC96施万细胞共同培养,通过改善培养条件,使之共同生长。经相差显微镜观察,确定共培养的两种细胞可发生相互作用。透射电镜观察单独培养的神经细胞、施万细胞及共培养时细胞超微结构的变化。观察IGF-1的影响:实验分为共培养对照组和IGF-1组(20 ng/ml)。培养5天后,收集细胞进行扫描电镜和透射电镜观察。结果透射电镜观察单独培养的神经细胞及施万细胞均可见不同的分化状态,其超微结构各异。透射电镜结果:与对照组相比,IGF-1组中细胞表面绒毛状或指状突起明显增多且联系紧密。扫描电镜结果:对照组与IGF-1组中均可见RSC96细胞包绕轴突形成髓鞘(可称之为成髓的施万细胞)。对照组中所有的细胞表面均比较平滑,绒毛样突起不明显。IGF-1组的细胞表面不再光滑,神经细胞和未成髓的施万细胞表面呈明显的绒毛样突起,而包裹轴突的成髓施万细胞表面主要呈片层状突起。结论 IGF-1可引起VSC4.1神经细胞和RSC96施万细胞超微结构及表面形态的改变。这或许是引起其功能改变的外在表现形式。

Purpose To determine the effects of insulin-like growth factor-1 on ultrastructure of co-cultured neuron cell （NC） and Schwann cell （SC） in vitro. Methods The VSC4. 1-RSC96 cells co-culture model was established and identified under phase contrast microscope. The ultrastructural changes of NC and SC cultured alone and co-cultured were observed using transmission election micros- copy （TEM）. The effects of insulin-like growth factor-I were detected. The co-cultured cells were assigned to IGF-1 affecting group （20 ng/ml） and control group. Those cells were observed under scanning electron microscope （SEM） after 5 days of culture. Results NC and SC showed different differentiation stages and ultrastructural features. The cellular surfaces of IGF-1 affecting group revealed more microvilli-like or finger-shape protuberances than that of the control group under TEM. In those two groups RSC96 cells had wrap- ping axon to form myelination （myelinating SC ）. All cellular surfaces in the control group were smooth without villous or protuber- ances. In the IGF-1 affecting group there were villi in the surfaces of NC and non-myelinating SC, but the lamellar-like protuberances appeared in the surface of myelinating SC which wrapped the axon of NC. Conclusion IGF-1 can cause the changes of microstructures and surface morphology of VSC4. 1 and RSC96 cells. Those morphology changes may be the manifestations of the alteration of cellular behaviors.