title: Enhanced protection against renal ischemia-reperfusion injury with combined melatonin and exendin-4 in a rodent model.
abstract: We tested the hypothesis that combined treatment with melatonin, an anti-oxidant, and exendin-4, an anti-inflammatory agent, was superior to either alone for protecting the kidney from ischemia-reperfusion (IR) injury. Male adult Sprague-Dawley rats (n=40) were equally divided into group 1 (sham-operated control), group 2 (IR only, IR=1h/72h), group 3 (IR-exendin-4, 10 µg/kg at 30 min, 24 h, 48 h after IR procedure), group 4 (IR-melatonin, i.p. 50 mg at 30 min, then 20 mg at 6 and 18 h after IR procedure), and group 5 (combined IR-exendin-4-melatonin). All animals were sacrificed by 72 h after IR/sham procedure. The results showed that the kidney injury score, plasma creatinine, and blood urea nitrogen (BUN) levels were highest in group 2 and lowest in group 1, significantly higher in groups 3 and 4 than those in group 5 and significantly higher in group 3 than those in group 4 (all p < 0.001). The protein expressions of inflammatory (toll-like receptor 4, inducible nitric oxide synthase, interleukin-1β), apoptotic (mitochondrial Bax, cleaved caspase-3 and poly(ADP-ribose) polymerase, p53), podocyte integrity (E-cadherin, P-cadherin), and cell survival (phosphatidylinositol-3-kinase/AKT/mammalian target of rapamycin) biomarkers, as well the podocyte dysfunction biomarkers (Wnt1/Wnt4/β-catenin) displayed a pattern identical to that of creatinine level among the five groups (all p < 0.001). Microscopic findings demonstrated that podocyte dysfunction (Wnt1/Wnt4/β-catenin expression) and inflammatory (CD14 and F4/80-positively stained cells) biomarkers exhibited an identical pattern, whereas that of antioxidant (HO-1(+), NQO-1(+) cells) biomarkers showed an opposite pattern compared to that of creatinine level among the five groups (all p < 0.001). Combined melatonin-exendin-4 therapy offered an additional benefit in protecting the kidney from acute IR injury.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Xiamen Chang Gung Memorial Hospital, Fujian 361028, China.
authors.forename: Yi-Chih
authors.initials: YC
authors.lastname: Chang
authors.affiliation: Department of Anatomy, Chang Gung University, Taoyuan 33302, Taiwan.
authors.forename: Shu-Yuan
authors.initials: SY
authors.lastname: Hsu
authors.affiliation: Division of Nephrology Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan.
authors.forename: Chih-Chao
authors.initials: CC
authors.lastname: Yang
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan.
authors.forename: Pei-Hsun
authors.initials: PH
authors.lastname: Sung
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan.
authors.forename: Yi-Ling
authors.initials: YL
authors.lastname: Chen
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan.
authors.forename: Tien-Hung
authors.initials: TH
authors.lastname: Huang
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan.
authors.forename: Gour-Shenq
authors.initials: GS
authors.lastname: Kao
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan.
authors.forename: Sheng-Yi
authors.initials: SY
authors.lastname: Chen
authors.affiliation: Department of Anesthesiology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan.
authors.forename: Kuan-Hung
authors.initials: KH
authors.lastname: Chen
authors.affiliation: Department of Obstetrics and Gynecology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan.
authors.forename: Hsin-Ju
authors.initials: HJ
authors.lastname: Chiang
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 83301, Taiwan Center for Shockwave Medicine and Tissue Engineering, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 83301, Taiwan Department of Medical Research, China Medical University Hospital, China Medical University, Taichung 40402, Taiwan han.gung@msa.hinet.net twinfan@seed.net.tw.
authors.forename: Hon-Kan
authors.initials: HK
authors.lastname: Yip
authors.affiliation: Division of thoracic and Cardiovascular Surgery, Department of Surgery, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan.
authors.forename: Fan-Yen
authors.initials: FY
authors.lastname: Lee
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology / Q000627:therapeutic use*; D000975:Antioxidants / Q000494:pharmacology / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects; D015415:Biomarkers / Q000097:blood; D001806:Blood Urea Nitrogen; D003404:Creatinine / Q000097:blood / Q000652:urine; D000077270:Exenatide; D007668:Kidney / Q000187:drug effects / Q000293:injuries / Q000473:pathology; D008297:Male; D008550:Melatonin / Q000494:pharmacology / Q000627:therapeutic use*; D018384:Oxidative Stress; D010455:Peptides / Q000494:pharmacology / Q000627:therapeutic use*; D011507:Proteinuria; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000517:prevention & control*; D015398:Signal Transduction / Q000187:drug effects; D014688:Venoms / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D000893:Anti-Inflammatory Agents; D000975:Antioxidants; D015415:Biomarkers; D010455:Peptides; D014688:Venoms; D000077270:Exenatide; D003404:Creatinine; D008550:Melatonin
keywords: Acute kidney ischemia–reperfusion injury; apoptosis; inflammation; phosphatidylinositol-3-kinase/AKT/mammalian target of rapamycin signaling pathway