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Hypoglycemia enhances the expression of prion protein and heat‐shock protein 70 in a mouse neuroblastoma cell line
Author(s) -
Shyu W.C.,
Chen C.P.,
Saeki K.,
Kubosaki A.,
Matusmoto Y.,
Onodera T.,
Ding D.C.,
Chiang M.F.,
Lee Y.J.,
Lin S.Z.,
Li H.
Publication year - 2005
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.20509
Subject(s) - hsp70 , hypoglycemia , heat shock protein , downregulation and upregulation , in vitro , promoter , microbiology and biotechnology , phosphorylation , biology , blot , heat shock , endocrinology , medicine , gene expression , biochemistry , insulin , gene
Cellular prion protein (PrP C ) expression can be regulated by heat‐shock stress, and we designed the present study to determine whether hypoglycemia could affect PrP C expression. RT‐PCR and Western blotting were used to measure the expression of PrP C and heat‐shock protein (Hsp70) in mouse neuroblastoma (N18) cells cultured 3 hr to 3 days in media deprived of 97.5% (L) or 75% (M) of its glucose. Hypoglycemia caused a concomitant time‐dependent and glucose dose‐dependent increase in PrP C and Hsp70. In addition, hypoglycemia also increased phosphorylated c‐Jun N‐terminal kinase (JNK) protein levels in a time‐dependent manner. The upregulation of PrP C and Hsp70 under hypoglycemic conditions was disrupted by the specific JNK inhibitor SP600125. It was also found from in vitro studies that hypoglycemic conditions induced higher levels of PrP C promoter activity in PrP C promoters containing a heat‐shock element (HSE) than in PrP C promoters lacking HSE. We propose that hypoglycemia‐increased PrP C expression might be due to JNK phosphorylation of a heat‐shock transcriptional factor, which then interacts with HSE in the promoter of PrP C . © 2005 Wiley‐Liss, Inc.