title: Ubiquitination and regulation of Smad7 in the TGF-β1/Smad signaling of aristolochic acid nephropathy.
abstract: Aristolochic acid I (AAI) affects TGF-β1/Smad signaling, which causes AA nephropathy (AAN), but the mechanisms are not fully understood. We aimed to clarify whether Arkadia and UCH37 participate in TGF-β1/Smad signaling via Smad7, and the regulatory mechanisms of Smad7. One side, mice and cultured mouse renal tubular epithelial cells (RTECs) were treated with various AAI doses and concentrations, respectively; on the other side, RTECs were transfected with small interfering RNA (siRNA) expression vectors against Arkadia and UCH37 and then treated with 10 µg/ml AAI. And then detect the mRNA and protein levels of Smad7, UCH37, Arkadia and any other relative factors by RT-PCR and Western blotting. In kidney tissues and RTECs, the mRNA and protein levels of Smad7 decreased with increasing AAI doses concentrations by real-time PCR and Western blotting, whereas those of Arkadia, UCH37, Smad2, Smad3 and TβRI increased. Cells transfected with the Arkadia siRNA expression vector showed reduced mRNA and protein levels of vimentin, α-SMA, Smad2, Smad3 and TβRI after AAI treatment, while those of CK18 and Smad7 increased compared with those of untransfected RTECs. Conversely, cells transfected with the UCH37 siRNA expression vector showed the opposite effect on analyzed signaling molecules after AAI treatment. Arkadia and UCH37 participate in TGF-β1/Smad signaling-mediated renal fibrosis, and Smad7 blocks TGF-β1 signaling by inhibiting Smad2/Smad3 phosphorylation and enhancing the degradation of TβRI.
authors.affiliation: a Laboratory of Veterinary Pharmacology , Animal Science and Technology College, Beijing University of Agriculture , Beijing , China .
authors.forename: Yahui
authors.initials: Y
authors.lastname: Tian
authors.affiliation: a Laboratory of Veterinary Pharmacology , Animal Science and Technology College, Beijing University of Agriculture , Beijing , China .
authors.forename: Fangfang
authors.initials: F
authors.lastname: Liao
authors.affiliation: b Maternity and Child Care Center , Changchun, Jilin , China , and.
authors.forename: Guoying
authors.initials: G
authors.lastname: Wu
authors.affiliation: a Laboratory of Veterinary Pharmacology , Animal Science and Technology College, Beijing University of Agriculture , Beijing , China .
authors.forename: Di
authors.initials: D
authors.lastname: Chang
authors.affiliation: a Laboratory of Veterinary Pharmacology , Animal Science and Technology College, Beijing University of Agriculture , Beijing , China .
authors.forename: Yaohui
authors.initials: Y
authors.lastname: Yang
authors.affiliation: a Laboratory of Veterinary Pharmacology , Animal Science and Technology College, Beijing University of Agriculture , Beijing , China .
authors.forename: Xiaokai
authors.initials: X
authors.lastname: Dong
authors.affiliation: a Laboratory of Veterinary Pharmacology , Animal Science and Technology College, Beijing University of Agriculture , Beijing , China .
authors.forename: Zhongwen
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: c Wanger Biotechnology Co., Ltd. , Beijing , PR China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: a Laboratory of Veterinary Pharmacology , Animal Science and Technology College, Beijing University of Agriculture , Beijing , China .
authors.forename: Guojuan
authors.initials: G
authors.lastname: Wu
mesh_terms: D000818:Animals; D034341:Aristolochic Acids / Q000633:toxicity*; D002273:Carcinogens / Q000633:toxicity*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation / Q000187:drug effects; D007684:Kidney Tubules / Q000166:cytology / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D051379:Mice; D009393:Nephritis / Q000139:chemically induced / Q000276:immunology / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011499:Protein Processing, Post-Translational; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000819:agonists / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D051906:Smad7 Protein / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D053773:Transforming Growth Factor beta1 / Q000378:metabolism; D043222:Ubiquitin Thiolesterase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D054875:Ubiquitination / Q000187:drug effects*
chemical_list: D034341:Aristolochic Acids; D002273:Carcinogens; D012333:RNA, Messenger; D018125:Receptors, Transforming Growth Factor beta; D051906:Smad7 Protein; C497807:Smad7 protein, mouse; C508961:Tgfb1 protein, mouse; D053773:Transforming Growth Factor beta1; C000228:aristolochic acid I; C427283:Rnf111 protein, mouse; D044767:Ubiquitin-Protein Ligases; D017346:Protein Serine-Threonine Kinases; D000077293:Receptor, Transforming Growth Factor-beta Type I; D043222:Ubiquitin Thiolesterase; C581032:Uchl5 protein, mouse
keywords: Aristolochic acid nephropathy; Arkadia; Smad7; TGF-β1/Smad signaling pathway; UCH37