title: MicroRNA-184 is a downstream effector of albuminuria driving renal fibrosis in rats with diabetic nephropathy.
abstract: Renal fibrosis is a common complication of diabetic nephropathy and is a major cause of end-stage renal disease. Despite the suggested link between renal fibrosis and microRNA (miRNA) dysregulation in diabetic nephropathy, the identification of the specific miRNAs involved is still incomplete. The aim of this study was to investigate miRNA profiles in the diabetic kidney and to identify potential downstream targets implicated in renal fibrosis.
  
  
  
  miRNA expression profiling was investigated in the kidneys of 8-month-old Zucker diabetic fatty (ZDF) rats during overt nephropathy. Localisation of the most upregulated miRNA was established by in situ hybridisation. The candidate miRNA target was identified by in silico analysis and its expression documented in the diabetic kidney associated with fibrotic markers. Cultured tubule cells served to assess which of the profibrogenic stimuli acted as a trigger for the overexpressed miRNA, and to investigate underlying epigenetic mechanisms.
  
  
  
  In ZDF rats, miR-184 showed the strongest differential upregulation compared with lean rats (18-fold). Tubular localisation of miR-184 was associated with reduced expression of lipid phosphate phosphatase 3 (LPP3) and collagen accumulation. Transfection of NRK-52E cells with miR-184 mimic reduced LPP3, promoting a profibrotic phenotype. Albumin was a major trigger of miR-184 expression. Anti-miR-184 counteracted albumin-induced LPP3 downregulation and overexpression of plasminogen activator inhibitor-1. In ZDF rats, ACE-inhibitor treatment limited albuminuria and reduced miR-184, with tubular LPP3 preservation and tubulointerstitial fibrosis amelioration. Albumin-induced miR-184 expression in tubule cells was epigenetically regulated through DNA demethylation and histone lysine acetylation and was accompanied by binding of NF-κB p65 subunit to miR-184 promoter.
  
  
  
  These results suggest that miR-184 may act as a downstream effector of albuminuria through LPP3 to promote tubulointerstitial fibrosis, and offer the rationale to investigate whether targeting miR-184 in association with albuminuria-lowering drugs may be a new strategy to achieve fully anti-fibrotic effects in diabetic nephropathy.
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126, Bergamo, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Zanchi
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126, Bergamo, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Macconi
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126, Bergamo, Italy.
authors.forename: Piera
authors.initials: P
authors.lastname: Trionfini
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126, Bergamo, Italy.
authors.forename: Susanna
authors.initials: S
authors.lastname: Tomasoni
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126, Bergamo, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Rottoli
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126, Bergamo, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Locatelli
authors.affiliation: Medical University Innsbruck, Department of Internal Medicine IV-Nephrology and Hypertension, Innsbruck, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Rudnicki
authors.affiliation: Biogazelle, Zwijnaarde, Belgium.
authors.forename: Jo
authors.initials: J
authors.lastname: Vandesompele
authors.affiliation: Biogazelle, Zwijnaarde, Belgium.
authors.forename: Pieter
authors.initials: P
authors.lastname: Mestdagh
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126, Bergamo, Italy.|Unit of Nephrology and Dialysis, Azienda Socio Sanitaria Territoriale (ASST) Papa Giovanni XXIII, Bergamo, Italy.|Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Remuzzi
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126, Bergamo, Italy.
authors.forename: Ariela
authors.initials: A
authors.lastname: Benigni
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126, Bergamo, Italy. carlamaria.zoja@marionegri.it.
authors.forename: Carlamaria
authors.initials: C
authors.lastname: Zoja
mesh_terms: D000419:Albuminuria / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D047369:Chromatin Immunoprecipitation; D019295:Computational Biology; D003928:Diabetic Nephropathies / Q000235:genetics / Q000378:metabolism*; D005355:Fibrosis / Q000235:genetics / Q000378:metabolism*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007674:Kidney Diseases / Q000235:genetics / Q000378:metabolism*; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism; D010711:Phosphatidate Phosphatase / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D051381:Rats; D011924:Rats, Zucker; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: C000602309:MIRN184 microRNA, rat; D035683:MicroRNAs; D016328:NF-kappa B; D010711:Phosphatidate Phosphatase
keywords: Albuminuria; Diabetic nephropathy; Fibrosis; Zucker diabetic fatty rats; miR-184