title: Silencing of microRNA-132 reduces renal fibrosis by selectively inhibiting myofibroblast proliferation.
abstract: Chronic kidney disease is associated with progressive renal fibrosis, where perivascular cells give rise to the majority of α-smooth muscle actin (α-SMA) positive myofibroblasts. Here we sought to identify pericytic miRNAs that could serve as a target to decrease myofibroblast formation. Kidney fibrosis was induced in FoxD1-GC;Z/Red-mice by unilateral ureteral obstruction followed by FACS sorting of dsRed-positive FoxD1-derivative cells and miRNA profiling. MiR-132 selectively increased 21-fold during pericyte-to-myofibroblast formation, whereas miR-132 was only 2.5-fold up in total kidney lysates (both in obstructive and ischemia-reperfusion injury). MiR-132 silencing during obstruction decreased collagen deposition (35%) and tubular apoptosis. Immunohistochemistry, Western blot, and qRT-PCR confirmed a similar decrease in interstitial α-SMA(+) cells. Pathway analysis identified a rate-limiting role for miR-132 in myofibroblast proliferation that was confirmed in vitro. Indeed, antagomir-132-treated mice displayed a reduction in the number of proliferating Ki67(+) interstitial myofibroblasts. Interestingly, this was selective for the interstitial compartment and did not impair the reparative proliferation of tubular epithelial cells, as evidenced by an increase in Ki67(+) epithelial cells, as well as increased phospho-RB1, Cyclin-A and decreased RASA1, p21 levels in kidney lysates. Additional pathway and gene expression analyses suggest miR-132 coordinately regulates genes involved in TGF-β signaling (Smad2/Smad3), STAT3/ERK pathways, and cell proliferation (Foxo3/p300). Thus, silencing miR-132 counteracts the progression of renal fibrosis by selectively decreasing myofibroblast proliferation and could potentially serve as a novel antifibrotic therapy.
authors.affiliation: Department of Nephrology and the Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center (LUMC), Leiden, the Netherlands; Renal Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA. Electronic address: r.bijkerk@lumc.nl.
authors.forename: Roel
authors.initials: R
authors.lastname: Bijkerk
authors.affiliation: Department of Nephrology and the Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center (LUMC), Leiden, the Netherlands.
authors.forename: Ruben G
authors.initials: RG
authors.lastname: de Bruin
authors.affiliation: Department of Nephrology and the Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center (LUMC), Leiden, the Netherlands.
authors.forename: Coen
authors.initials: C
authors.lastname: van Solingen
authors.affiliation: Department of Nephrology and the Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center (LUMC), Leiden, the Netherlands.
authors.forename: Janine M
authors.initials: JM
authors.lastname: van Gils
authors.affiliation: Department of Nephrology and the Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center (LUMC), Leiden, the Netherlands.
authors.forename: Jacques M G J
authors.initials: JM
authors.lastname: Duijs
authors.affiliation: Department of Nephrology and the Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center (LUMC), Leiden, the Netherlands.
authors.forename: Eric P
authors.initials: EP
authors.lastname: van der Veer
authors.affiliation: Department of Nephrology and the Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center (LUMC), Leiden, the Netherlands.
authors.forename: Ton J
authors.initials: TJ
authors.lastname: Rabelink
authors.affiliation: Renal Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA; Renal Division, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Humphreys
authors.affiliation: Department of Nephrology and the Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center (LUMC), Leiden, the Netherlands.
authors.forename: Anton Jan
authors.initials: AJ
authors.lastname: van Zonneveld
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D000070416:Antagomirs / Q000235:genetics; D017209:Apoptosis; D002460:Cell Line; D049109:Cell Proliferation / Q000235:genetics*; D003094:Collagen / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism; D005355:Fibrosis; D006801:Humans; D007150:Immunohistochemistry; D007668:Kidney / Q000473:pathology*; D007684:Kidney Tubules / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000235:genetics*; D058628:Myofibroblasts / Q000378:metabolism / Q000502:physiology*; D020286:Pericytes / Q000378:metabolism; D034622:RNA Interference; D051436:Renal Insufficiency, Chronic / Q000473:pathology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics; D016212:Transforming Growth Factor beta
chemical_list: C541116:ACTA2 protein, human; D000199:Actins; D000070416:Antagomirs; C546976:MIRN132 microRNA, mouse; D035683:MicroRNAs; D016212:Transforming Growth Factor beta; C544013:alpha-smooth muscle actin, mouse; D003094:Collagen
keywords: chronic kidney disease; fibrosis; transforming growth factor β