The Variations Of MAPK Signaling Pathway In Microglia And The Effect Of Catalpol

Objective: The objective of this study was to investigate the variations of MAPK signaling pathway and the influence of Catalpol on the signaling pathway in microglia on the base of our previous study.Methods: BV2 cell line and PC12 cell line were used to stand for microglia and neurons respectively in this study. PC12 cell was cultured with the medium of BV2 cell, which was cultured with or without catalpol in the condition of hypoxia. The function of BV2 cell was evaluated by measuring the survival of PC12 cell with the method of CCK-8.Meanwhile the protein expression and phosphorylation levels of ERK1/2, p38MAPK and JNK in BV2 cell were detected by Western blot.Results: 1.we used gray values to represent the expression of protein (gray value was proportional to the expression of protein). When BV2 cell presented protective role, the level of p-ERK1/2 was significantly higher than that of p-p38MAPK and p-JNK, the gray values of them were 0.277±0.010,0.221±0.019 and 0.163±0.003 respectively. When BV2 cell showed damage role, the levels of p-p38MAPK and p-JNK increased further to 0.398±0.005 and 0.495±0.050 respectively, while the level of p-ERK1 / 2 was not significant change, it was 0.282±0.005 . 2.Catalpol could enhance the protective role of BV2 cell and alleviate its damage role, meanwhile it also could significantly decrease the levels of p-p38MAPK and p-JNK no matter protective or damage role in BV2 cell. the levels of p-p38MAPK and p-JNK decreased from 0.211±0.019 and 0.163±0.003 to 0.125±0.009 and 0.077±0.002 respectively when catalpol was used in the situation that BV2 cell showed protective role, the values decreased from 0.398±0.005 and 0.495±0.050 to 0.265±0.011 and 0.304±0.002 respectively when catalpol was used in the situation that BV2 cell played damage role. Catalpol did not show any influence on the level of p-ERK1/2 either under protective role or damage role in BV2. Conclusions:1.The function of microglia might be associated with ERK1/2,p38MAPK and JNK phosphorylation levels in hypoxia conditions. p38MAPK and JNK signaling pathway were concerned with the damage role of microglia,and ERK1/2 signaling pathway was concerned with the protective role of microglia.2.Catalpol performed protective function by inhibiting JNK and p38MAPK signal pathway in BV2 cell in hypoxia.