title: Overexpression of heme oxygenase-1 protects dopaminergic neurons against 1-methyl-4-phenylpyridinium-induced neurotoxicity.
abstract: Heme oxygenase-1 (HO-1) is up-regulated in response to oxidative stress and catalyzes the degradation of pro-oxidant heme to carbon monoxide (CO), iron, and bilirubin. Intense HO-1 immunostaining in the Parkinsonian brain is demonstrated, indicating that HO-1 may be involved in the pathogenesis of Parkinsonism. We here locally injected adenovirus containing human HO-1 gene (Ad-HO-1) into rat substantia nigra concomitantly with 1-methyl-4-phenylpyridinium (MPP(+)). Seven days after injection of MPP(+) and Ad-HO-1, the brain was isolated for immunostaining and for measurement of dopamine content and inflammatory cytokines. It was found that overexpression of HO-1 significantly increased the survival rate of dopaminergic neurons; reduced the production of tumor necrosis factor alpha (TNF-alpha) and interleukin-1beta (IL-1beta) in substantia nigra; antagonized the reduction of striatal dopamine content induced by MPP(+); and also up-regulated brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) expression in substantia nigra. Apomorphine-induced rotation after MPP(+) treatment was also inhibited by Ad-HO-1. On the other hand, inhibition of HO enzymatic activity by zinc protoporphyrin-IX facilitated the MPP(+)-induced rotatory behavior and enhanced the reduction of dopamine content. HO-1 overexpression also protected dopaminergic neurons against MPP(+)-induced neurotoxicity in midbrain neuron-glia cocultures. Overexpression of HO-1 increased the expression of BDNF and GDNF in astrocytes and BDNF in neurons. Our results indicate that HO-1 induction exerts neuroprotection both in vitro and in vivo. Pharmacological or genetic approaches targeting HO-1 may represent a promising and novel therapeutic strategy in treating Parkinsonism.
authors.affiliation: Pharmacological Institute, College of Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Shih-Ya
authors.initials: SY
authors.lastname: Hung
authors.forename: Houng-Chi
authors.initials: HC
authors.lastname: Liou
authors.forename: Kai-Hsiang
authors.initials: KH
authors.lastname: Kang
authors.forename: Ruey-Meei
authors.initials: RM
authors.lastname: Wu
authors.forename: Chun-Chiang
authors.initials: CC
authors.lastname: Wen
authors.forename: Wen-Mei
authors.initials: WM
authors.lastname: Fu
mesh_terms: D015655:1-Methyl-4-phenylpyridinium; D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000096:biosynthesis / Q000235:genetics; D016923:Cell Death; D002478:Cells, Cultured; D018920:Coculture Techniques; D004298:Dopamine / Q000378:metabolism*; D004790:Enzyme Induction; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000096:biosynthesis / Q000235:genetics; D051547:Heme Oxygenase-1 / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D053583:Interleukin-1beta / Q000378:metabolism; D009457:Neuroglia / Q000473:pathology; D009474:Neurons / Q000473:pathology*; D010302:Parkinson Disease, Secondary / Q000139:chemically induced / Q000201:enzymology / Q000473:pathology*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D051100:Glial Cell Line-Derived Neurotrophic Factor; D053583:Interleukin-1beta; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D051547:Heme Oxygenase-1; D015655:1-Methyl-4-phenylpyridinium; D004298:Dopamine