title: Down-regulation of BNIP3 by olomoucine, a CDK inhibitor, reduces LPS- and NO-induced cell death in BV2 microglial cells.
abstract: Proinflammatory responses eliciting the microglial production of cytokines and nitric oxide (NO) have been reported to play a crucial role in the acute and chronic pathogenic effects of neurodegeneration. Chemical inhibitors of cyclin-dependent kinases (CDKs) may prevent the progression of neurodegeneration by both limiting cell proliferation and reducing cell death. However, the mechanism underlying the protective effect of CDK inhibitors on microglia remains unexplored. In this study, we found that olomoucine, a CDK inhibitor, alleviated lipopolysaccharide (LPS)-induced BV2 microglial cell death by reducing the generation of NO and inhibiting the gene expression of proinflammatory cytokines. In addition, olomoucine reduced inducible NO synthase promoter activity and alleviated NF-κB- and E2F-mediated transcriptional activation. NO-induced cell death involved mitochondrial disruptions such as cytochrome c release and loss of mitochondrial membrane potential, and pretreatment with olomoucine prior to NO exposure reduced these disruptions. Microarray analysis revealed that olomoucine treatment induced prominent down-regulation of Bcl2/adenovirus E1B 19-kDa-interacting protein 3 (BNIP3), a pro-apoptotic Bcl-2 family protein that is involved in mitochondrial disruption. As BNIP3 knock-down significantly increased the viability of LPS- and NO-treated BV2 cells, we conclude that olomoucine may protect cells by limiting proinflammatory responses, thereby reducing NO generation. Simultaneously, down-regulation of BNIP3 prevents NO stimulation from inducing mitochondrial disruption.
authors.affiliation: Department of Bioscience and Biotechnology, Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 20224, Taiwan.
authors.forename: Yu-Chi
authors.initials: YC
authors.lastname: Tsou
authors.affiliation: Section of Urology, Cheng-Hsin General Hospital, Taipei 11211, Taiwan.
authors.forename: Hsiao-Hsien
authors.initials: HH
authors.lastname: Wang
authors.affiliation: Section of Urology, Cheng-Hsin General Hospital, Taipei 11211, Taiwan.
authors.forename: Chii-Cheng
authors.initials: CC
authors.lastname: Hsieh
authors.affiliation: Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University, Taipei 11211 Taiwan; Department of Education and Research, Taipei City Hospital, Taipei 100, Taiwan.
authors.forename: Kuang-Hui
authors.initials: KH
authors.lastname: Sun
authors.affiliation: Division of Urology, Department of Surgery, Tri-service General Hospital, National Defense Medical Center, Taipei 11100, Taiwan.
authors.forename: Guang-Huan
authors.initials: GH
authors.lastname: Sun
authors.affiliation: Department of Bioscience and Biotechnology, Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 20224, Taiwan.
authors.forename: Ren-Shiang
authors.initials: RS
authors.lastname: Jhou
authors.affiliation: Department of Bioscience and Biotechnology, Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 20224, Taiwan.
authors.forename: Tz-I
authors.initials: TI
authors.lastname: Lin
authors.affiliation: Department of Bioscience and Biotechnology, Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 20224, Taiwan.
authors.forename: Shou-Yun
authors.initials: SY
authors.lastname: Lu
authors.affiliation: Division of Urology, Department of Surgery, Taoyuan Armed Forces General, Taiwan.
authors.forename: Huan-Yun
authors.initials: HY
authors.lastname: Liu
authors.affiliation: Department of Bioscience and Biotechnology, Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 20224, Taiwan. Electronic address: tsj@mail.ntou.edu.tw.
authors.forename: Shye-Jye
authors.initials: SJ
authors.lastname: Tang
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002460:Cell Line; D049109:Cell Proliferation; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors*; D015536:Down-Regulation; D050684:E2F Transcription Factors / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000008:administration & dosage; D007249:Inflammation / Q000139:chemically induced / Q000378:metabolism*; D018836:Inflammation Mediators / Q000378:metabolism; D007701:Kinetin / Q000008:administration & dosage*; D008070:Lipopolysaccharides; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D017628:Microglia / Q000187:drug effects* / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism
chemical_list: C508686:BNip3 protein, mouse; D050684:E2F Transcription Factors; D004791:Enzyme Inhibitors; D018836:Inflammation Mediators; D008070:Lipopolysaccharides; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D016328:NF-kappa B; D009569:Nitric Oxide; C090046:olomoucine; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D018844:Cyclin-Dependent Kinases; D007701:Kinetin
keywords: BNIP3; BV2 cells; Inflammation; Microglia; Nitric oxide; Olomoucine