title: miR-141 as a regulator of the mitochondrial phosphate carrier (Slc25a3) in the type 1 diabetic heart.
abstract: Dysfunctional mitochondria are central in the pathogenesis of diabetic cardiomyopathy. Mitochondrial proteomic alterations resulting from diabetes mellitus have been reported although the mechanisms driving changes in proteomic signatures are unknown. microRNAs (miRNAs) have been considered as potential regulators of proteins. The goal of this study was to determine whether miRNAs play a role in diabetes-induced mitochondrial proteomic alterations. Quanitative RT-PCR miRNA screening in diabetic mice, 5 wk following multiple low-dose streptozotocin treatment was associated with alteration in the expression of 29 miRNAs in the diabetic heart compared with control. Among those miRNAs upregulated in the diabetic heart was miR-141 (P < 0.002). miRNA target prediction analyses identified miR-141 as a potential regulator of the inner mitochondrial membrane phosphate transporter, solute carrier family 25 member 3 (Slc25a3), which provides inorganic phosphate to the mitochondrial matrix and is essential for ATP production. With the use of a luciferase reporter construct with a Slc25a3 3'-untranslated region (UTR) target sequence, overexpression of miR-141 downregulated luciferase activity levels confirming miR-141/Slc25a3 3'-UTR binding. miR-141 overexpression in HL-1 cells elicited a decrease in Slc25a3 protein content, ATP production and a decrease in ATP synthase activity, similar to the diabetic phenotype (P < 0.05, for both). Diabetic interfibrillar mitochondria (IFM) displayed decreased Slc25a3 protein content, which was inversely correlated with increased miR-141 expression. Further, diabetic IFM ATP synthase activity was also decreased (P < 0.05). Together these results indicate that miR-141 can regulate Slc25a3 protein expression in the diabetic heart. Further, diabetes-induced miRNA changes may influence mitochondrial proteomes and functional processes such as mitochondrial ATP production.
authors.affiliation: Center for Cardiovascular and Respiratory Sciences, Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV 26506, USA.
authors.forename: Walter A
authors.initials: WA
authors.lastname: Baseler
authors.forename: Dharendra
authors.initials: D
authors.lastname: Thapa
authors.forename: Rajaganapathi
authors.initials: R
authors.lastname: Jagannathan
authors.forename: Erinne R
authors.initials: ER
authors.lastname: Dabkowski
authors.forename: Tara L
authors.initials: TL
authors.lastname: Croston
authors.forename: John M
authors.initials: JM
authors.lastname: Hollander
mesh_terms: D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism*; D058065:Diabetic Cardiomyopathies / Q000378:metabolism*; D008297:Male; D051379:Mice; D035683:MicroRNAs / Q000378:metabolism*; D008929:Mitochondria, Heart / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000096:biosynthesis*; D025261:Mitochondrial Proton-Translocating ATPases / Q000378:metabolism; D028061:Phosphate Transport Proteins / Q000096:biosynthesis*
chemical_list: D035683:MicroRNAs; C543718:Mirn141 microRNA, mouse; D024101:Mitochondrial Proteins; D028061:Phosphate Transport Proteins; C422067:SLC25A3 protein, human; D025261:Mitochondrial Proton-Translocating ATPases