[Apoptosis of neuroglial cell and expressions of neurite outgrowth inhibitor B and MAP kinase-activated protein kinase 2 in white matter damage model of newborn rat brain].

OBJECTIVE: To observe and explore the apoptosis of neuroglial cell and the expression changes of neurite outgrowth inhibitor B (Nogo-B) and MAP kinase-activated protein kinase 2 (MK2) in SD rats with white matter damage (WMD).

METHODS: The WMD model of newborn rat was established for this study, and then the pups were respectively killed at 30 min, 1 h, 4 h, 12 h, 1 d, 3 d, 7 d, 14 d, 21 d after WMD. The apoptosis of neuroglial cells was investigated by TUNEL method; the changes of Nogo-B expression in white matter were investigated by immunohistochemical technique; the changes of expression of MK2 mRNA in white matter were measured by in situ hybridization.

RESULTS: TUNEL result showed the number of apoptotic cells increased at 4 h and peaked at 3 d, decreased at 7 d after WMD of newborn rat; the expression of MK2 mRNA began to increase at 1 h and reached a maximum at 3 d (P<0.05); the expression of Nogo-B in periventricular white matter and corpus callosum of WMD rat was up-regulated at 12 h and peaked at 3 d after cerebral white matter damage, displaying significant differences at 12 h, 1 d, 3 d and 7 d when the Nogo-B expression in WMD rat compared with that observed in the control (P<0.05).

CONCLUSION: Nogo-B and MK2 can participate in pathogenesis of white matter damage in newborn rat.