title: Valproic acid increases NO production via the SH-PTP1-CDK5-eNOS-Ser(116) signaling cascade in endothelial cells and mice.
abstract: Valproic acid (VPA) with its inhibitory activity of histone deacetylase has been used in the treatment of epilepsy and bipolar disorder associated with cerebrovascular dysfunction. Because nitric oxide (NO) produced by endothelial NO synthase (eNOS) plays a role in the maintenance of vascular function, NO is likely to mediate VPA׳s drug effect, but its effect on NO production remains controversial. We investigated whether and how VPA regulates NO production in bovine aortic endothelial cells (BAECs) and mice. VPA increased NO production in BAECs, which was accompanied by a decrease in phosphorylation of eNOS at serine 116 (eNOS-Ser(116)) and cyclin-dependent kinase 5 at tyrosine 15 (CDK5-Tyr(15)). Ectopic expression of p25, a CDK5 activator, restored the VPA-inhibited eNOS-Ser(116) phosphorylation. In silico analysis revealed that the CDK5-Tyr(15) residue might be a substrate for SH2 domain-containing protein tyrosine phosphatase 1 (SH-PTP1), and CDK5 actually interacted with SH-PTP1. VPA increased SH-PTP1 expression and its activity. Stibogluconate, a specific SH-PTP1 inhibitor, reversed the VPA-inhibited phosphorylation of CDK5-Tyr(15) and eNOS-Ser(116). Knockdown of SH-PTP1 using small interfering RNA also reversed all the observed effects of VPA. Finally, both serum NO level and acetylcholine-induced aortic relaxation increased in VPA-medicated male mice. These increases were accompanied by increased SH-PTP1 expression and decreased phosphorylation of CDK5-Tyr(15) and eNOS-Ser(116) in mouse aortas. In conclusion, VPA increases NO production by inhibiting the CDK5-Tyr(15)-eNOS-Ser(116) phosphorylation axis; this process is mediated by SH-PTP1. VPA may be useful in the treatment of NO-related cerebrocardiovascular diseases.
authors.affiliation: Department of Neurology, Konkuk University Medical Center, and Department of Pharmacology, Center for Geriatric Neuroscience Research, SMART Institute of Advanced Biomedical Science, and Gwangjin-gu, Seoul 143-701, Korea; Department of Pharmacology, School of Medicine, Eulji University, Jung-gu, Daejeon 301-746, Korea.
authors.forename: Du-Hyong
authors.initials: DH
authors.lastname: Cho
authors.affiliation: Department of Molecular Medicine, Ewha Womans University Medical School, Yangcheon-gu, Seoul 158-710, Korea.
authors.forename: Jung-Hyun
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Neurology, Konkuk University Medical Center, and Department of Pharmacology, Center for Geriatric Neuroscience Research, SMART Institute of Advanced Biomedical Science, and Gwangjin-gu, Seoul 143-701, Korea.
authors.forename: Eun
authors.initials: E
authors.lastname: Joo Lee
authors.affiliation: Department of Medical Science, Institute of Functional Genomics, Konkuk University School of Medicine, Chungju 380-701, Korea.
authors.forename: Kyung
authors.initials: K
authors.lastname: Jong Won
authors.affiliation: Department of Microbiology, Chungbuk National University, Heungduk-gu, Cheongju 361-763, Korea.
authors.forename: Sang-Hee
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Microbiology, Chungbuk National University, Heungduk-gu, Cheongju 361-763, Korea.
authors.forename: Yang-Hoon
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Department of Molecular Medicine, Ewha Womans University Medical School, Yangcheon-gu, Seoul 158-710, Korea.
authors.forename: Soojin
authors.initials: S
authors.lastname: Hwang
authors.affiliation: Department of Neurology, Konkuk University Medical Center, and Department of Pharmacology, Center for Geriatric Neuroscience Research, SMART Institute of Advanced Biomedical Science, and Gwangjin-gu, Seoul 143-701, Korea.
authors.forename: Kyoung
authors.initials: K
authors.lastname: Ja Kwon
authors.affiliation: Department of Neurology, Konkuk University Medical Center, and Department of Pharmacology, Center for Geriatric Neuroscience Research, SMART Institute of Advanced Biomedical Science, and Gwangjin-gu, Seoul 143-701, Korea.
authors.forename: Chan
authors.initials: C
authors.lastname: Young Shin
authors.affiliation: Department of Internal Medicine, Konkuk University School of Medicine, Gwangjin-gu, Seoul 143-701, Korea.
authors.forename: Kee-Ho
authors.initials: KH
authors.lastname: Song
authors.affiliation: Department of Molecular Medicine, Ewha Womans University Medical School, Yangcheon-gu, Seoul 158-710, Korea. Electronic address: inhojo@ewha.ac.kr.
authors.forename: Inho
authors.initials: I
authors.lastname: Jo
authors.affiliation: Department of Neurology, Konkuk University Medical Center, and Department of Pharmacology, Center for Geriatric Neuroscience Research, SMART Institute of Advanced Biomedical Science, and Gwangjin-gu, Seoul 143-701, Korea. Electronic address: alzdoc@kuh.ac.kr.
authors.forename: Seol-Heui
authors.initials: SH
authors.lastname: Han
mesh_terms: D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology*; D001011:Aorta / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D015153:Blotting, Western; D002417:Cattle; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D051360:Cyclin-Dependent Kinase 5 / Q000235:genetics / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D007124:Immunoenzyme Techniques; D047468:Immunoprecipitation; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009569:Nitric Oxide / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics; D017382:Reactive Oxygen Species / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D054593:SH2 Domain-Containing Protein Tyrosine Phosphatases; D012694:Serine / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D020349:Surface Plasmon Resonance; D014635:Valproic Acid / Q000494:pharmacology*
chemical_list: D000927:Anticonvulsants; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D012694:Serine; D014635:Valproic Acid; D052250:Nitric Oxide Synthase Type III; D051360:Cyclin-Dependent Kinase 5; D054593:SH2 Domain-Containing Protein Tyrosine Phosphatases
keywords: Cyclin-dependent kinase 5; Endothelial nitric oxide synthase; Free radicals; Histone deacetylase; Nitric oxide; SH2 domain-containing protein tyrosine phosphatase 1; Valproic acid