Effect Of P38MAPK Signaling Pathway On Cell Function And NGF、TNFα Secretion Of Microglia Cells

Objective: To determine the effects of p38MAPK signaling pathway in microgliacell function and the cytokine secretion, and to explore the underlying mechanisms ofp38MAPK signaling pathway in microglia cell function.Methods: In this study, BV2(Mouse microglia tumor cells) and PC12(Ratchromaffin tumor cells) cell lines were used to represent microglia and neuron,respectively. BV2cells were cultured with or without p38MAPK signaling pathwayblocker (SB203580) under hypoxia stimulation, whose condition media were then usedfor PC12cells culture. CCK-8was performed to evaluate cell viability in PC12cells, inwhich way the effects of BV2cells in different conditions were determined. ELISA wasperformed to detect the secretory expression of TNF-α, IL-1β and NGF in BV2cells.Results:1. NGF, TNF-α and IL-1β were secreted by BV2cells under hypoxiastimulation. After1hour of hypoxia, the secretion levels of NGF, TNF-α and IL-1β were215.81±13.11pg/ml,808.91±7.41pg/ml, and7.89±0.47pg/ml, respectively; after theblockage of p38MAPK signaling pathway by SB203580treatment, they became376.25±11.67pg/ml,544.85±8.13pg/ml and4.75±0.23pg/ml, respectively (p<0.01).After12hour of hypoxia, the secretion levels of NGF, TNF-α and IL-1β were142.35±1.60pg/ml,1569.27±19.07pg/ml, and28.53±6.2pg/ml, respectively; after theblockage of p38MAPK signaling pathway by SB203580treatment, the secretion levelof IL-1β was24.50±2.10pg/ml. However, the secretion level of NGF and TNF-αbecame166.40±3.74pg/ml and1127.88±14.03pg/ml. The level of NGF was obviouslyhigh and the level of TNF-α was markedly low after adding the blocker of p38MAPKsignaling pathway（p<0.01）.3. Cell viability in normal control PC12group was100%, while cell viability was71.4%and86.9%（p<0.01）in hypoxia (1h) group and hypoxia (1h)+SB203580group,respectively;29.6%and51.4%（p<0.01）in hypoxia (12h) group and hypoxia (12h)+ SB203580group, respectively. Cell viability was obviously increased after the blockageof p38MAPK signaling pathway.Conclusions:1. The injury effect of microglia may be related with the p38MAPKsignaling pathway, and the protective effect of microglia cells could be enhanced by theblockage of p38MAPK signaling pathway.2. NGF and TNFα were secreted by microglia cells under hypoxia, which wasrelated with p38MAPK signaling pathway.