title: L-malate enhances the gene expression of carried proteins and antioxidant enzymes in liver of aged rats.
abstract: Previous studies in our laboratory reported L-malate as a free radical scavenger in aged rats. To investigate the antioxidant mechanism of L-malate in the mitochondria, we analyzed the change in gene expression of two malate-aspartate shuttle (MAS)-related carried proteins (AGC, aspartate/glutamate carrier and OMC, oxoglutarate/malate carrier) in the inner mitochondrial membrane, and three antioxidant enzymes (CAT, SOD, and GSH-Px) in the mitochondria. The changes in gene expression of these proteins and enzymes were examined by real-time RT-PCR in the heart and liver of aged rats treated with L-malate. L-malate was orally administered in rats continuously for 30 days using a feeding atraumatic needle. We found that the gene expression of OMC and GSH-Px mRNA in the liver increased by 39 % and 38 %, respectively, in the 0.630 g/kg L-malate treatment group than that in the control group. The expression levels of SOD mRNA in the liver increased by 39 %, 56 %, and 78 % in the 0.105, 0.210, and 0.630 g/kg L-malate treatment groups, respectively. No difference were observed in the expression levels of AGC, OMC, CAT, SOD, and GSH-Px mRNAs in the heart of rats between the L-malate treatment and control groups. These results predicted that L-malate may increase the antioxidant capacity of mitochondria by enhancing the expression of mRNAs involved in the MAS and the antioxidant enzymes.
authors.affiliation: Guangdong Institute of Microbiology, Guangzhou, China. Zhangjm926@126.com and microwjl@yahoo.com.
authors.forename: X
authors.initials: X
authors.lastname: Zeng
authors.forename: J
authors.initials: J
authors.lastname: Wu
authors.forename: Q
authors.initials: Q
authors.lastname: Wu
authors.forename: J
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000367:Age Factors; D000375:Aging / Q000235:genetics / Q000378:metabolism*; D026922:Amino Acid Transport Systems, Acidic / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000378:metabolism* / Q000494:pharmacology*; D017920:Antiporters / Q000187:drug effects / Q000378:metabolism; D002352:Carrier Proteins / Q000187:drug effects / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D004798:Enzymes / Q000235:genetics / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D005979:Glutathione Peroxidase / Q000378:metabolism; D008099:Liver / Q000187:drug effects* / Q000201:enzymology; D008293:Malates / Q000494:pharmacology*; D008297:Male; D026901:Membrane Transport Proteins / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D008930:Mitochondria, Liver / Q000187:drug effects / Q000201:enzymology; D024101:Mitochondrial Proteins; D012333:RNA, Messenger / Q000378:metabolism; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013482:Superoxide Dismutase / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D026922:Amino Acid Transport Systems, Acidic; D000975:Antioxidants; D017920:Antiporters; D002352:Carrier Proteins; D004798:Enzymes; D008293:Malates; D026901:Membrane Transport Proteins; D024101:Mitochondrial Proteins; D012333:RNA, Messenger; C051046:aspartate-glutamate carrier; C066909:2-oxoglutarate-malate carrier protein; C030298:malic acid; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase