Effect of Hypoxia/Reoxygenation on Cell Viability and Expression and Secretion of Neurotrophic Factors (NTFs) in Primary Cultured Schwann Cells

Abstract

As the primary myelin-forming cells of the peripheral nervous system, Schwann cells (SCs) play a key role in the regeneration of injured peripheral nerves. However, hypoxia causes injury of SCs, as observed in peripheral neuropathies, including those caused by diabetes. So we investigated the effect of hypoxia/reoxygenation (H/R) on SCs in this study. To do so, SCs were cultured in hypoxic condition in vitro and then in normal condition for 24 hr; The effects H/R on SCs were evaluated by MTT (3(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide) assay, Hoechst staining, immunocytochemistry, western blotting, ELISA, and RT-PCR. H/R resulted in a significant decrease in SCs survival and an increase in caspase-3 activity. H/R also reduced the mRNA level of BDNF (brain derived neurotrophic factor) and its secretion, but NGF mRNA level was elevated in these cells. These observations showed that H/R induces death of primary cultured SCs, and different mechanisms responsible for regulating NGF and BDNF expression.