Enhanced phosphatidylinositol 4-phosphate 5-kinase alpha expression and PI(4,5)P2 production in LPS-stimulated microglia.
Lee, SY; Kim, B; Jeong, HK; Min, KJ; Liu, T; Park, JY; Joe, EH; Jou, I
Neurochemistry international, 57(5):600-607, 2010
Microglia are the major glial cells responsible for immune responses against harmful substances in the central nervous system. Type I phosphatidylinositol 4-phosphate 5-kinase alpha (PIP5Kalpha) and its lipid product, phosphatidylinositol 4,5-bisphosphate (PI[4,5]P(2)), regulate important cell surface functions. Here, we report that lipopolysaccharide (LPS) significantly enhanced PIP5Kalpha mRNA and protein expression levels in a time- and concentration-dependent manner in microglia. Furthermore, LPS stimulation led to a robust increase in PI(4,5)P(2) in the plasma membrane, demonstrated by PI(4,5)P(2) immunostaining or PI(4,5)P(2) imaging using a PI(4,5)P(2)-specific probe, tubby (R332H), fused to yellow fluorescent protein. Phosphatidylinositol 3-kinase, p38 mitogen-activated protein kinase (MAPK), p42/44 MAPK, and c-Jun N-terminal kinase signaling pathway inhibitors clearly reduced PIP5Kalpha expression, indicating that these pathways are necessary for LPS-induced PIP5Kalpha expression. In addition, inhibition of nuclear factor-kappaB and Sp1 transcription factors interfered with the LPS-induced upregulation of PIP5Kalpha. Delivery of PI(4,5)P(2) into microglia increased the expression of interleukin-1beta and tumor necrosis factor alpha. These findings indicate that PIP5Kalpha upregulation and the subsequent rise in PI(4,5)P(2) in LPS-stimulated microglia may positively regulate microglial inflammatory responses.
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.
Total Visit :3,089,272
Total Download :1,260,877
Today View :397
Ajou University Medical Information & Media Center 164 Worldcup-ro Yeongtong-gu Suwon 16499 Korea / TEL : 031-219-5312 / FAX : 031-219-5314 Copyright (c) Ajou University Medical Information & Media Center All Rights Reserved. AJOU Open Repository는 국립중앙도서관 OAK 보급사업으로 구축되었습니다.