Axonal regulation of Schwann cell differentiation and integrin α6β4 expression / 北京大学学报(医学版)

ABSTRACT

Objective: To study the axonal effect and the expression of integrin α6β4 during Schwann cell(SC) differentiation and myelination. Methods: Schwann cells were dissociated from the sciatic nerve of neonatal Waster rats and neurons dissociated from spinal cord. Singal cultures and purified populations of SC were cocultured with NC. Four methods (contrast microscope, scanning electron microscopy(SEM), immunocytochemistry method and in situ hybridization ) were used. Results: The separately cultured Schwann cells showed MBP negetive by immunocytochemistry method. But cocultured SC were shown positive. SEM showed that Schwann cells' membrane loop progressively circumnavigated around the axon during myelination, which suggested that the non-myelinating SC(nMSC) transformed to myelinating SC (MSC). In situ hybridization showed integrin α6β4 positive signals only on the outer surface of the Schwann cell-axon unit in SC coculture with NC. Conclusion: The differentiation and maturation of SC depend on axon, and the activity of integrins is expressed by axon. Axonal contact induces the expression of α6β4 during SC myelination, which suggests that integrin α6β4 is an important mediator of interactions of myelinating SC with the basal limina.