title: Promoter demethylation of cystathionine-β-synthetase gene contributes to inflammatory pain in rats.
abstract: Hydrogen sulfide (H(2)S), an endogenous gas molecule synthesized by cystathionine-β-synthetase (CBS), is involved in inflammation and nociceptive signaling. However, the molecular and epigenetic mechanisms of CBS-H(2)S signaling in peripheral nociceptive processing remain unknown. We demonstrated that peripheral inflammation induced by intraplantar injection of complete Freund adjuvant significantly up-regulated expression of CBS at both protein and mRNA levels in rat dorsal root ganglia (DRG). The CBS inhibitors hydroxylamine and aminooxyacetic acid attenuated mechanical hyperalgesia in a dose-dependent manner and reversed hyperexcitability of DRG neurons in inflamed rats. Intraplantar administration of NaHS (its addition mimics CBS production of H(2)S) or l-cysteine in healthy rats elicited mechanical hyperalgesia. Application of NaHS in vitro enhanced excitability and tetrodotoxin (TTX)-resistant sodium current of DRG neurons from healthy rats, which was attenuated by pretreatment of protein kinase A inhibitor H89. Methylation-specific PCR and bisulfite sequencing demonstrated that promoter region of cbs gene was less methylated in DRG samples from inflamed rats than that from controls. Peripheral inflammation did not alter expression of DNA methyltransferase 3a and 3b, the 2 major enzymes for DNA methylation, but led to a significant up-regulation of methyl-binding domain protein 4 and growth arrest and DNA damage inducible protein 45α, the enzymes involved in active DNA demethylation. Our findings suggest that epigenetic regulation of CBS expression may contribute to inflammatory hyperalgesia. H(2)S seems to increase TTX-resistant sodium channel current, which may be mediated by protein kinase A pathway, thus identifying a potential therapeutic target for the treatment of chronic pain.
authors.affiliation: Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong 226001, PR China Institute of Neuroscience, Department of Neurobiology and Psychology, Key Laboratory of Pain Research and Therapy, Soochow University, Suzhou 215123, PR China Department of Anesthesiology and the Graduate Program in Neuroscience, University of Cincinnati College of Medicine, P.O. Box 670531, 231 Albert Sabin Way, Cincinnati, OH 45267-0531, USA.
authors.forename: Feihu
authors.initials: F
authors.lastname: Qi
authors.forename: Youlang
authors.initials: Y
authors.lastname: Zhou
authors.forename: Ying
authors.initials: Y
authors.lastname: Xiao
authors.forename: Jin
authors.initials: J
authors.lastname: Tao
authors.forename: Jianguo
authors.initials: J
authors.lastname: Gu
authors.forename: Xinghong
authors.initials: X
authors.lastname: Jiang
authors.forename: Guang-Yin
authors.initials: GY
authors.lastname: Xu
mesh_terms: D000818:Animals; D001483:Base Sequence; D059350:Chronic Pain / Q000139:chemically induced / Q000235:genetics* / Q000276:immunology; D018899:CpG Islands / Q000502:physiology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D003541:Cystathionine beta-Synthase / Q000235:genetics* / Q000378:metabolism*; D003545:Cysteine / Q000633:toxicity; D019175:DNA Methylation / Q000502:physiology*; D004195:Disease Models, Animal; D057890:Epigenomics; D005727:Ganglia, Spinal / Q000502:physiology; D006930:Hyperalgesia / Q000139:chemically induced / Q000235:genetics / Q000276:immunology; D007249:Inflammation / Q000139:chemically induced / Q000235:genetics* / Q000276:immunology; D007546:Isoquinolines / Q000494:pharmacology; D008969:Molecular Sequence Data; D018408:Patch-Clamp Techniques; D011401:Promoter Regions, Genetic / Q000502:physiology; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012964:Sodium / Q000378:metabolism; D026941:Sodium Channel Blockers / Q000494:pharmacology; D013440:Sulfides / Q000633:toxicity; D013449:Sulfonamides / Q000494:pharmacology; D013779:Tetrodotoxin / Q000494:pharmacology
chemical_list: D007546:Isoquinolines; D047428:Protein Kinase Inhibitors; D026941:Sodium Channel Blockers; D013440:Sulfides; D013449:Sulfonamides; D013779:Tetrodotoxin; D012964:Sodium; D017868:Cyclic AMP-Dependent Protein Kinases; D003541:Cystathionine beta-Synthase; C025451:sodium bisulfide; D003545:Cysteine; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide