1.Influence of mitochondrial deficiency on expression of microtubule-associated proteins in primary cultured hippocampal neurons of neonatal rats
Lan ZHANG ; Wenlin AN ; Lin LI ; Bing XUE ; Liqin BAN ; Xiaoming LI ; Yanling XU ; Shuse LIU
Chinese Journal of Pathophysiology 2000;0(12):-
AIM: In order to study the relationship between mitochondrial deficiency and Alzheimer's disease(AD), we used sodium azide, a specific inhibitor of cytochrome C oxidase(COX), to develop a cell model of mitochondrial complex IV deficiency and investigated the impairment of microtubules and microtubule-associated proteins. METHODS: Primary cultured hippocampal neurons of hewborn rats were exposed to sodium azide ,then cell viability was measured by MTT method; cell morphology, immunofluorecence-stained cellular microtubules and microtubule-associated proteins were observed by confocal microscopy. RESULTS: Primary cultured hippocampal neurons were exposed to 8-128 mmol/L sodium azide for 3-24 h, MTT absorbance decreased dose-and time-dependently. Exposed to 64 mmol/L sodium azide for 6 h, the processes of cells retracted, synapses disappeared, axons were shortened under contrast microscope. Meanwhile, microtubles were disassembled and became disorderly, the expression of microtubule-associated proteins were also reduced especially in the processes observed by confocal microscopy. CONCLUSIONS: Sodium azide inhibits the assembly and polymerization of tubulin in microtubules which may be reduced by low expression of microtubule-associated proteins in nerve cells. The damage of axons induced by microtubule collapse further blocks the intercellular signal transduction and intracellular material transportation which are important causes in cell death.