title: Augmented O-GlcNAc signaling via glucosamine attenuates oxidative stress and apoptosis following contrast-induced acute kidney injury in rats.
abstract: Contrast-induced acute kidney injury (CI-AKI) is an iatrogenic renal injury and associated with substantial morbidity and mortality in susceptible individuals. Despite extensive study of a variety of agents for renal protection, limited strategies have been shown to be effective in the reduction of CI-AKI. O-linked β-N-acetylglucosamine (O-GlcNAc) is a post-translational regulatory modification of intracellular proteins and governs the function of numerous proteins, both cytosolic and nuclear. Increasing evidence suggests that O-GlcNAc levels are increased in response to stress and that acute augmentation of this reaction is cytoprotective. However, the underlying mechanisms by which augmented OGlcNAc signaling provides renoprotection against contrast media insults is still unknown. Here, we investigated the effect of augmented O-GlcNAc signaling via glucosamine on CI-AKI and explored the underlying molecular mechanisms, particularly its relationship with PI3-kinase (PI3K)/Akt signaling. We used a novel and reliable CI-AKI model consisting of 5/6 nephrectomized (NE) rats, and a low-osmolar contrast media (iohexol, 10mL/kg, 3.5gI) injected via the tail vein after dehydration for 48h. The results showed that augmented O-GlcNAc signaling by glucosamine prevented the kidneys against iohexol-induced injury characterized by the attenuation of renal dysfunction, tubular damage, apoptosis and oxidative stress. Furthermore, this renoprotection was blocked by treatment with alloxan, an O-GlcNAc transferase inhibitor. Augmented O-GlcNAc signaling also increased the protein expression levels of phospho-Akt (Ser473, but not Thr308 and Thr450), phospho-GSK-3β, Nrf2, and Bcl-2, and decreased the levels of Bax and cleaved caspase-3. Both alloxan and specific inhibitors of PI3K (Wortmannin and LY294002) blocked the protection of glucosamine via inhibiting Akt signaling pathway. We further identified O-GlcNAcylated Akt through immunoprecipitation and western blot. We confirmed that Akt was modified by O-GlcNAcylation, and glucosamine pretreatment increased the O-GlcNAcylation of Akt. Collectively, the results demonstrate that glucosamine induces renoprotection against CI-AKI through augmented O-GlcNAc and activation of PI3K/Akt signaling, making it a promising strategy for preventing CI-AKI.
authors.affiliation: Division of Nephrology, Zhongshan Hospital, Shanghai Medical College, Fudan University, Shanghai 200032, China; Shanghai Institute of Kidney and Dialysis, Shanghai 200032, China; Key Laboratory of Kidney and Blood Purification of Shanghai, Shanghai 200032, China; Quality Control Center of Dialysis, Shanghai 200032, China.
authors.forename: Jiachang
authors.initials: J
authors.lastname: Hu
authors.affiliation: Division of Nephrology, Zhongshan Hospital, Shanghai Medical College, Fudan University, Shanghai 200032, China; Shanghai Institute of Kidney and Dialysis, Shanghai 200032, China; Key Laboratory of Kidney and Blood Purification of Shanghai, Shanghai 200032, China; Quality Control Center of Dialysis, Shanghai 200032, China.
authors.forename: Rongyi
authors.initials: R
authors.lastname: Chen
authors.affiliation: Division of Nephrology, Zhongshan Hospital, Shanghai Medical College, Fudan University, Shanghai 200032, China; Shanghai Institute of Kidney and Dialysis, Shanghai 200032, China; Key Laboratory of Kidney and Blood Purification of Shanghai, Shanghai 200032, China; Quality Control Center of Dialysis, Shanghai 200032, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Jia
authors.affiliation: Division of Nephrology, Zhongshan Hospital, Shanghai Medical College, Fudan University, Shanghai 200032, China; Shanghai Institute of Kidney and Dialysis, Shanghai 200032, China; Key Laboratory of Kidney and Blood Purification of Shanghai, Shanghai 200032, China; Quality Control Center of Dialysis, Shanghai 200032, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Fang
authors.affiliation: Division of Nephrology, The Affiliated Chang zhou No. 2 Hospital of Nanjing Medical College, Changzhou, Jiangsu 213003, China.
authors.forename: Tongqiang
authors.initials: T
authors.lastname: Liu
authors.affiliation: Division of Nephrology, Zhongshan Hospital, Shanghai Medical College, Fudan University, Shanghai 200032, China; Shanghai Institute of Kidney and Dialysis, Shanghai 200032, China; Key Laboratory of Kidney and Blood Purification of Shanghai, Shanghai 200032, China; Quality Control Center of Dialysis, Shanghai 200032, China.
authors.forename: Nana
authors.initials: N
authors.lastname: Song
authors.affiliation: Division of Nephrology, Zhongshan Hospital, Shanghai Medical College, Fudan University, Shanghai 200032, China; Shanghai Institute of Kidney and Dialysis, Shanghai 200032, China; Key Laboratory of Kidney and Blood Purification of Shanghai, Shanghai 200032, China; Quality Control Center of Dialysis, Shanghai 200032, China.
authors.forename: Xialian
authors.initials: X
authors.lastname: Xu
authors.affiliation: Division of Nephrology, Zhongshan Hospital, Shanghai Medical College, Fudan University, Shanghai 200032, China; Shanghai Institute of Kidney and Dialysis, Shanghai 200032, China; Key Laboratory of Kidney and Blood Purification of Shanghai, Shanghai 200032, China; Quality Control Center of Dialysis, Shanghai 200032, China. Electronic address: ji.jun@zs-hospital.sh.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Ji
authors.affiliation: Division of Nephrology, Zhongshan Hospital, Shanghai Medical College, Fudan University, Shanghai 200032, China; Shanghai Institute of Kidney and Dialysis, Shanghai 200032, China; Key Laboratory of Kidney and Blood Purification of Shanghai, Shanghai 200032, China; Quality Control Center of Dialysis, Shanghai 200032, China. Electronic address: ding.xiaoqiang@zs-hospital.sh.cn.
authors.forename: Xiaoqiang
authors.initials: X
authors.lastname: Ding
mesh_terms: D000117:Acetylglucosamine / Q000494:pharmacology*; D058186:Acute Kidney Injury; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D003287:Contrast Media / Q000633:toxicity*; D004353:Drug Evaluation, Preclinical; D007472:Iohexol / Q000633:toxicity*; D007668:Kidney / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008297:Male; D018384:Oxidative Stress; D010766:Phosphorylation; D020011:Protective Agents / Q000494:pharmacology*; D011499:Protein Processing, Post-Translational; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction
chemical_list: D003287:Contrast Media; D020011:Protective Agents; D007472:Iohexol; D051057:Proto-Oncogene Proteins c-akt; D000117:Acetylglucosamine
keywords: Acute kidney injury; Glycogen synthase kinase-3β; Hexosamine biosynthetic pathway; Iodinated contrast media