title: miR-192 induces G2/M growth arrest in aristolochic acid nephropathy.
abstract: Aristolochic acid nephropathy is characterized by rapidly progressive tubulointerstitial nephritis culminating in end-stage renal failure and urothelial malignancy. Profibrotic effects of aristolochic acid are linked to growth arrest of proximal tubular epithelial cells; however, the underlying mechanisms are largely undetermined. miRNAs are small, endogenous, post-transcriptional regulators of gene expression implicated in numerous physiological and pathological processes. In the present study, we characterized the mechanism of aristolochic acid-induced cell cycle arrest and its regulation by miRNAs. Incubation with aristolochic acid led to profound G2/M arrest in proximal tubular epithelial cells via p53-mediated inactivation of the maturation-promoting complex, CDK1/cyclin-B1. Analysis of miRNA expression identified up-regulation of miRNAs, including miR-192, miR-194, miR-450a, and miR-542-3p. The stable overexpression of miR-192 recapitulated G2/M arrest via repression of the E3 ubiquitin ligase, murine double-minute 2, a negative regulator of p53. p53-induced transcription of p21(cip1) and growth arrest and DNA damage 45 and resulted in the inactivation and dissociation of the maturation-promoting complex. These data demonstrate a core role for miR-192 in mediating proximal tubular epithelial cell G2/M arrest after toxic injury by aristolochic acid. Because numerous studies have linked such growth arrest to fibrosis after proximal tubular epithelial cell injury, this mechanism may have widespread relevance to recovery/nonrecovery after acute kidney injury.
authors: Institutes of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Wales, United Kingdom.
authors: Robert H
authors: RH
authors: Jenkins
authors: Infection and Immunity, School of Medicine, Cardiff University, Wales, United Kingdom.
authors: Luke C
authors: LC
authors: Davies
authors: Infection and Immunity, School of Medicine, Cardiff University, Wales, United Kingdom.
authors: Philip R
authors: PR
authors: Taylor
authors: Toray Industries Inc., Tokyo, Japan.
authors: Hideo
authors: H
authors: Akiyama
authors: Central Biotechnologies Services, Institute of Translation, Innovation, Methodology and Engagement, School of Medicine, Cardiff University, Wales, United Kingdom.
authors: Bevan
authors: B
authors: Cumbes
authors: Institutes of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Wales, United Kingdom.
authors: Cristina
authors: C
authors: Beltrami
authors: Institutes of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Wales, United Kingdom.
authors: Christopher P
authors: CP
authors: Carrington
authors: Institutes of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Wales, United Kingdom.
authors: Aled O
authors: AO
authors: Phillips
authors: Institutes of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Wales, United Kingdom.
authors: Timothy
authors: T
authors: Bowen
authors: Institutes of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Wales, United Kingdom. Electronic address: fraserdj@cf.ac.uk.
authors: Donald J
authors: DJ
authors: Fraser
mesh_terms: D034341:Aristolochic Acids / Q000506:poisoning*; D015153:Blotting, Western; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000473:pathology; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D059565:G2 Phase Cell Cycle Checkpoints / Q000235:genetics*; D006801:Humans; D047468:Immunoprecipitation; D007674:Kidney Diseases / Q000139:chemically induced / Q000473:pathology*; D007687:Kidney Tubules, Proximal / Q000473:pathology; D059566:M Phase Cell Cycle Checkpoints / Q000235:genetics*; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology
chemical_list: D034341:Aristolochic Acids; C546783:MIRN192 microRNA, human; D035683:MicroRNAs