Hypoxia-inducible factor-1alpha protects cultured cortical neurons from lipopolysaccharide-induced cell death via regulation of NR1 expression.
Inflammation is involved in some neurodegenerative disorders. NMDA glutamate receptors play an important role in neuronal development. Here, we show that NR1 expression in the cerebral cortex and primary neurons of rats was upregulated after lipopolysaccharide (LPS) treatment. This increase in NR1 expression was considered to be strongly associated with hypoxia-inducible factor-1alpha (HIF-1alpha) activation because the treatment of primary neurons with either echinomycin or small interfering RNA (siRNA) targeting HIF-1alpha could block NR1 expression. HIF-1alpha could be induced by an increase in the translational efficiency of the cells. After this, it was transported into the nucleus where it bound to the NR1 promoter and regulated the induction of NR1 transcriptional activity by LPS. LPS injection into the prefrontal cortex caused neuronal death, and this condition was aggravated by intracerebroventricular injection of echinomycin. Furthermore, knockdown of HIF-1alpha and NR1 by the appropriate siRNAs reduced the neurite outgrowth and viability of the primary neurons. These results suggest that NR1 expression is regulated by HIF-1alpha and plays a protective role in neurons during LPS challenge.
Yeh
Shiu-Hwa
SH
Department of Pharmacology, College of Medicine, National Cheng-Kung University, Tainan 701, Taiwan.
Hung
Jan-Jong
JJ
Gean
Po-Wu
PW
Chang
Wen-Chang
WC
D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D016923:Cell Death / Q000187:drug effects; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology* / Q000378:metabolism*; D004448:Echinomycin / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009474:Neurons / Q000187:drug effects*; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors
D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D008070:Lipopolysaccharides; C489787:MAP2 protein, rat; D008869:Microtubule-Associated Proteins; C409466:NR1 NMDA receptor; D019384:Nucleic Acid Synthesis Inhibitors; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D016194:Receptors, N-Methyl-D-Aspartate; D004448:Echinomycin; D010751:Phosphopyruvate Hydratase