Melatonin pretreatment enhances the therapeutic effects of exogenous mitochondria against hepatic ischemia-reperfusion injury in rats through suppression of mitochondrial permeability transition.
J Pineal Res. 2016 Mar 18. Epub 2016 Mar 18. PMID: 26993080
We tested the hypothesis that melatonin (Mel) enhances exogenous mitochondria (Mito) treatment against rodent hepatic ischemia-reperfusion (IR) injury. In vitro study utilized three groups of hepatocytes (i.e., non-treatment, menadione, and menadione-melatonin treatment, 4.0 x 10(5) each), while in vivo study involved adult male Sprague-Dawley rats (n=40) equally divided into sham-control (SC), IR (60-min left lobe ischemia + 72-hr reperfusion), IR-Mel (melatonin at 30 min/6h/8h after reperfusion), IR-Mito (mitochondria 15000μg/rat 30 min after reperfusion), and IR-Mel-Mito. Following menadione treatment in vitro, oxidative-stress (NOX-1/NOX-2/oxidized protein), apoptotic (cleaved caspase-3/PARP), DNA-damage (γ-H2AX/CD90/XRCC1), mitochondria-damage (cytosolic cytochrome-C) biomarkers and mitochondrial permeability transition were lower, whereas mitochondrial cytochrome-C were higher in hepatocytes with melatonin treatment compared to those without (all p<0.001). In vivo study demonstrated highest liver injury score and serum AST in IR group but lowest in SC group, higher in IR-Mito group than that in groups IR-Mel and IR-Mel-Mito, and higher in IR-Mel group than that in IR-Mel-Mito group after 72-hour reperfusion (all p<0.003). Protein expressions of inflammatory (TNF-α/NF-κB/IL-1β/MMP-9), oxidative-stress (NOX-1/NOX-2/oxidized protein), apoptotic (caspase-3/PARP/Bax), mitochondria-damage (cytosolic cytochrome-C) biomarkers displayed an identical pattern, whereas mitochondria integrity marker (mitochondrial cytochrome-C) showed an opposite pattern compared tothat of liver injury score (all p<0.001) among five groups. Microscopically, expressions of apoptotic nuclei, inflammatory (MPO(+) /CD68(+) /CD14(+) cells) and DNA-damage (γ-H2AX(+) cells) biomarkers exhibited an identical pattern compared to that of liver injury score (all p<0.001) among five groups. Melatonin-supported mitochondria treatment offered additional benefit of alleviating hepatic IR injury. This article is protected by copyright. All rights reserved.