Effect of Nerve Growth Factor on Cultured Rat Schwann Cells in Hyperglycemic Condition

Hyung, Geun Young; Kim, Kyoung Hee; Baek, Seung Hoon; Jang, Geun Young; Cho, Chung Gu

Abstract

BACKGROUND: Nerve growth factor (NGF) is produced in tissues innervafed by its responsive neurons. In the peripheral nervous system, NGF messenger RNA (mRNA) is produced in target fields of small pain and temperature-mediating dorsal root ganglia (DRG) sensory neurons and sympathetic neurons. NGF receptors are expressed in these neurons, and NGF has been shown to promote their survival, differentiation, as well as maintenance. However, the mechanism of neuronal damage in diabetes and the effect of NGF on diabetic neuropathy are unclear.
METHODS
in order to clarify the effect of hyperglycemia, the hyperglycemia-induced cytotoxic effects were evaluated by MTT assay on cultured rat Schwann cells, Schwann cells were grown with media containing concentrations of high glucose for inducing hyperglycemic condition. The neuroprotective effect of nerve growth factor (NGF) against hyperglycemia-induced Schwann cell changes were also examined. RESULT: 1. MMT50 value was at concentration of 25mM glucose after 72 hours, 2. Cell viability of cultured rat Schwann cells treated with hyperglycemic media made with 25~35mM glucose was markedly decreased in a dose-dependent manner when compared with control medium (normoglycemic medium) containing concentration of 5.5 mM glucose, While cell number did not show a dose- dependent decrease. 3. Cultured Schwann cells exposed to hyperglycemic medium made with 25mM glucose for 72 hours did nof show any morphological change as well as decrease of cell number. 4. Pretreatment of 10 ng/mL NGF for 2 hours increased remarkably the cell viability of cultured Schwann cells exposed to hyperglycemic medium(25mM glucose for 72 hours).
CONCLUSIONS
The results from this study suggested that hyperglycemic condition induces the decrease of cell viability on cultured Schwann cells of rat. But it did not show the decrease of cell number and rnorphological change. The selective neurotrophic factors such as NGF are very effective in preventing dysfunction of cells induced by hyperglycemic condition.