Involvement of calmodulin and actin in directed differentiation of rat cortical neural stem cells into neurons

Abstract

Calmodulin (CaM) is a multifunctional receptor of intercellular Ca2+, which under different physiological conditions or at different developmental stages plays different roles in different tissues and cells. This study aimed to investigate the involvement of spatial expression and coexistence of CaM and actin in directed differentiation of rat cortical neural stem cells (NSCs) into neurons. Immunohistochemistry, RT-PCR and immunofluorescence dual-labeling technology was conducted to investigate the temporal and spatial pattern of CaM and actin proteins in neuron-oriented cortical NSC differentiation. Confocal laser scanning microscopy (CLSM) was used to observe changes of the coexistence in protein expression. Our results showed that cortical NSCs expressed and showed localized CaM and actin in a well-defined temporal order. In the process of rat neuron-oriented cerebral cortical NSC differentiation, CaM displayed a similar expression pattern with actin in the development of neurons, that is, both proteins extended into neurites following the sprouting and growth of neurons. These results suggest that the temporal and spatial pattern of CaM and actin expression is comparable to the growth of cell processes in differentiating NSCs. Therefore, both CaM and actin may jointly participate in the development and maturation of neurites, and this provides a theoretical basis for further study of the biological features of neuron-oriented NSC differentiation.