title: Promoted interaction of nuclear factor-κB with demethylated cystathionine-β-synthetase gene contributes to gastric hypersensitivity in diabetic rats.
abstract: Patients with long-standing diabetes frequently demonstrate gastric hypersensitivity with an unknown mechanism. The present study was designed to investigate roles for nuclear factor-κB (NF-κB) and the endogenous H2S-producing enzyme cystathionine-β-synthetase (CBS) signaling pathways by examining cbs gene methylation status in adult rats with diabetes. Intraperitoneal injection of streptozotocin (STZ) produced gastric hypersensitivity in female rats in response to gastric balloon distention. Treatment with the CBS inhibitor aminooxyacetic acid significantly attenuated STZ-induced gastric hypersensitivity in a dose-dependent fashion. Aminooxyacetic acid treatment also reversed hyperexcitability of gastric-specific dorsal root ganglion (DRG) neurons labeled by the dye DiI in diabetic rats. Conversely, the H2S donor NaHS enhanced neuronal excitability of gastric DRG neurons. Expression of CBS and p65 were markedly enhanced in gastric DRGs in diabetic rats. Blockade of NF-κB signaling using pyrrolidine dithiocarbamate reversed the upregulation of CBS expression. Interestingly, STZ treatment led to a significant demethylation of CpG islands in the cbs gene promoter region, as determined by methylation-specific PCR and bisulfite sequencing. STZ treatment also remarkably downregulated the expression of DNA methyltransferase 3a and 3b. More importantly, STZ treatment significantly enhanced the ability of cbs to bind DNA at the p65 consensus site, as shown by chromatin immunoprecipitation assays. Our findings suggest that upregulation of cbs expression is attributed to cbs promoter DNA demethylation and p65 activation and that the enhanced interaction of the cbs gene and p65 contributes to gastric hypersensitivity in diabetes. This finding may guide the development and evaluation of new treatment modalities for patients with diabetic gastric hypersensitivity.
authors.affiliation: Division of Endocrinology, the Second Affiliated Hospital, Soochow University, Suzhou 215000, PR China.
authors.forename: Hong-Hong
authors.initials: HH
authors.lastname: Zhang
authors.forename: Ji
authors.initials: J
authors.lastname: Hu
authors.forename: You-Lang
authors.initials: YL
authors.lastname: Zhou
authors.forename: Shufen
authors.initials: S
authors.lastname: Hu
authors.forename: Yong-Meng
authors.initials: YM
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Ying
authors.initials: Y
authors.lastname: Xiao
authors.forename: Li-Yen Mae
authors.initials: LY
authors.lastname: Huang
authors.forename: Xinghong
authors.initials: X
authors.lastname: Jiang
authors.forename: Guang-Yin
authors.initials: GY
authors.lastname: Xu
mesh_terms: D000596:Amino Acids; D000704:Analysis of Variance; D000818:Animals; D019540:Area Under Curve; D016022:Case-Control Studies; D047369:Chromatin Immunoprecipitation; D018899:CpG Islands / Q000187:drug effects / Q000502:physiology; D003541:Cystathionine beta-Synthase / Q000235:genetics / Q000378:metabolism*; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics / Q000378:metabolism; D000090205:DNA Methyltransferase 3A; D003921:Diabetes Mellitus, Experimental / Q000150:complications*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004576:Electromyography; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005727:Ganglia, Spinal / Q000473:pathology; D006967:Hypersensitivity / Q000188:drug therapy / Q000209:etiology; D008564:Membrane Potentials / Q000187:drug effects; D008745:Methylation / Q000187:drug effects; D016328:NF-kappa B / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000378:metabolism; D029543:Nucleocytoplasmic Transport Proteins / Q000378:metabolism; D010072:Oxamic Acid / Q000627:therapeutic use; D018408:Patch-Clamp Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D011984:Sensory Receptor Cells / Q000187:drug effects / Q000502:physiology; D013272:Stomach Diseases / Q000188:drug therapy / Q000209:etiology*; D013447:Sulfites / Q000494:pharmacology; D015854:Up-Regulation / Q000187:drug effects; D000097584:DNA Methyltransferase 3B
chemical_list: D000596:Amino Acids; D003541:Cystathionine beta-Synthase; D004248:DNA (Cytosine-5-)-Methyltransferases; D000090205:DNA Methyltransferase 3A; D004791:Enzyme Inhibitors; D016328:NF-kappa B; D009363:Neoplasm Proteins; D029543:Nucleocytoplasmic Transport Proteins; D010072:Oxamic Acid; D013447:Sulfites; D000097584:DNA Methyltransferase 3B; C098463:dolaisoleucine; C063447:p65 oncofetal mRNA transport protein, rat; C569244:sodium hydrogen sulfite