title: Dysregulation between TRIM63/FBXO32 expression and soleus muscle wasting in diabetic rats: potential role of miR-1-3p, -29a/b-3p, and -133a/b-3p.
abstract: Diabetes mellitus (DM) induces a variable degree of muscle sarcopenia, which may be related to protein degradation and to the expression of both E3 ubiquitin ligases and some specific microRNAs (miRNAs). The present study investigated the effect of diabetes and acute muscle contraction upon the TRIM63 and FBXO32 expression as well as the potential involvement of some miRNAs. Diabetes was induced by streptozotocin and studied after 30 days. Soleus muscles were harvested, stimulated to contract in vitro for twitch tension analysis (0.5 Hz), 30 min later for tetanic analysis (100 Hz), and 30 min later were frozen. TRIM63 and FBXO32 proteins were quantified by western blotting; Trim63 mRNA, Fbxo32 mRNA, miR-1-3p, miR-29a-3p, miR-29b-3p, miR-133a-3p, and miR-133b-3p were quantified by qPCR. Diabetes induced sarcopenia by decreasing (P < 0.05) muscle weight/tibia length index, maximum tetanic contraction and relaxation rates, and absolute twitch and tetanic forces (P < 0.05). Diabetes decreased (P < 0.05) the Trim63 and Fbxo32 mRNAs (30%) and respective proteins (60%), and increased (P < 0.01) the miR-29b-3p (2.5-fold). In muscle from diabetic rats, acute contractile stimulus increased TRIM63 protein, miR-1-3p, miR-29a-3p, and miR-133a/b-3p, but decreased miR-29b-3p (P < 0.05). Independent of the metabolic condition, after muscle contraction, both TRIM63 and FBXO32 proteins correlated significantly with miR-1-3p, miR-29a/b-3p, and miR-133a/b-3p. All diabetes-induced regulations were reversed by insulin treatment. Concluding, the results depict that muscle wasting in long-term insulinopenic condition may not be accompanied by increased proteolysis, pointing out the protein synthesis as an important modulator of muscle sarcopenia in DM.
authors.affiliation: Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil. fredgerlinger@gmail.com.
authors.forename: Frederico
authors.identifier: http://orcid.org/0000-0002-2150-0384
authors.initials: F
authors.lastname: Gerlinger-Romero
authors.affiliation: Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Caio Yogi
authors.initials: CY
authors.lastname: Yonamine
authors.affiliation: Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Danilo Correa Pinto
authors.initials: DC
authors.lastname: Junior
authors.affiliation: Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: João Victor DelConti
authors.initials: JV
authors.lastname: Esteves
authors.affiliation: Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Ubiratan Fabres
authors.initials: UF
authors.lastname: Machado
mesh_terms: D000818:Animals; D048909:Diabetes Complications / Q000378:metabolism* / Q000473:pathology; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism* / Q000473:pathology; D005786:Gene Expression Regulation; D008297:Male; D035683:MicroRNAs / Q000378:metabolism*; D009124:Muscle Proteins / Q000096:biosynthesis*; D051381:Rats; D017208:Rats, Wistar; D044843:SKP Cullin F-Box Protein Ligases / Q000096:biosynthesis*; D055948:Sarcopenia / Q000378:metabolism* / Q000473:pathology; D000070584:Tripartite Motif Proteins / Q000096:biosynthesis*; D044767:Ubiquitin-Protein Ligases / Q000096:biosynthesis*
chemical_list: C542191:MIRN1 microRNA, rat; C549446:MIRN133 microRNA, rat; C526366:MIRN29 microRNA, rat; D035683:MicroRNAs; D009124:Muscle Proteins; D000070584:Tripartite Motif Proteins; C486692:Fbxo32 protein, rat; D044843:SKP Cullin F-Box Protein Ligases; C499086:Trim63 protein, rat; D044767:Ubiquitin-Protein Ligases
keywords: Acute contraction; Atrogene; Sarcopenia; Soleus; Streptozotocin