miR-192 mediates TGF-beta/Smad3-driven renal fibrosis.

TGF-beta/Smad3 promotes renal fibrosis, but the mechanisms that regulate profibrotic genes remain unclear. We hypothesized that miR-192, a microRNA expressed in the kidney may mediate renal fibrosis in a Smad3-dependent manner. Microarray and real-time PCR demonstrated a tight association between upregulation of miR-192 in the fibrotic kidney and activation of TGF-beta/Smad signaling. Deletion of Smad7 promoted miR-192 expression and enhanced Smad signaling and fibrosis in obstructive kidney disease. In contrast, overexpression of Smad7 to block TGF-beta/Smad signaling inhibited miR-192 expression and renal fibrosis in the rat 5/6 nephrectomy model; in vitro, overexpression of Smad7 in tubular epithelial cells abolished TGF-beta1-induced miR-192 expression. Furthermore, Smad3 but not Smad2 mediated TGF-beta1-induced miR-192 expression by binding to the miR-192 promoter. Last, overexpression of a miR-192 mimic promoted and addition of a miR-192 inhibitor blocked TGF-beta1-induced collagen matrix expression. Taken together, miR-192 may be a critical downstream mediator of TGF-beta/Smad3 signaling in the development of renal fibrosis.

[1]  E. Miska.  MicroRNAs — keeping cells in formation , 2008, Nature Cell Biology.

[2]  Hong-Jian Zhu,et al.  Role of TGF-beta signaling in extracellular matrix production under high glucose conditions. , 2003, Kidney international.

[3]  E. Bottinger,et al.  TGF-β signaling in renal disease , 2002 .

[4]  Gang Wang,et al.  Intrarenal expression of miRNAs in patients with hypertensive nephrosclerosis. , 2010, American journal of hypertension.

[5]  Seongjoon Koo,et al.  Development of a micro-array to detect human and mouse microRNAs and characterization of expression in human organs. , 2004, Nucleic acids research.

[6]  K. Lai,et al.  Disruption of the Smad7 gene promotes renal fibrosis and inflammation in unilateral ureteral obstruction (UUO) in mice. , 2009, Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association.

[7]  C. Heldin,et al.  The regulation of TGFβ signal transduction , 2009, Development.

[8]  Ivan Ovcharenko,et al.  rVISTA 2.0: evolutionary analysis of transcription factor binding sites , 2004, Nucleic Acids Res..

[9]  R. Kucherlapati,et al.  Deletion of Smad2 in Mouse Liver Reveals Novel Functions in Hepatocyte Growth and Differentiation , 2006, Molecular and Cellular Biology.

[10]  H. Lan,et al.  Angiotensin II Induces Connective Tissue Growth Factor and Collagen I Expression via Transforming Growth Factor–&bgr;–Dependent and –Independent Smad Pathways: The Role of Smad3 , 2009, Hypertension.

[11]  Youhua Liu,et al.  Renal fibrosis: new insights into the pathogenesis and therapeutics. , 2006, Kidney international.

[12]  H. Lan,et al.  Transforming growth factor‐β and Smad signalling in kidney diseases , 2005, Nephrology.

[13]  L. Truong,et al.  Advanced glycation end products activate Smad signaling via TGF‐β‐dependent and ‐independent mechanisms: implications for diabetic renal and vascular disease , 2004 .

[14]  八木 健,et al.  Alternatively spliced variant of smad2 lacking exon 3 : comparison with wild-type smad2 and smad3 , 2001 .

[15]  A. Roberts,et al.  Targeted disruption of SMAD3 results in impaired mucosal immunity and diminished T cell responsiveness to TGF‐β , 1999, The EMBO journal.

[16]  Aimee L Jackson,et al.  Coordinated regulation of cell cycle transcripts by p53-Inducible microRNAs, miR-192 and miR-215. , 2008, Cancer research.

[17]  C. Eng,et al.  A limited set of human MicroRNA is deregulated in follicular thyroid carcinoma. , 2006, The Journal of clinical endocrinology and metabolism.

[18]  M. Bitzer,et al.  TGF-beta signaling in renal disease. , 2002, Journal of the American Society of Nephrology : JASN.

[19]  H. Schnaper,et al.  It’s a Smad World: Regulation of TGF-β Signaling in the Kidney , 2002 .

[20]  H. Lan,et al.  Angiotensin II Induces Connective Tissue Growth Factor and Collagen I Expression via Transforming Growth Factor–&bgr;–Dependent and –Independent Smad Pathways: The Role of Smad3 , 2009, Hypertension.

[21]  Tso‐Hsiao Chen,et al.  Ultrasound-microbubble-mediated gene transfer of inducible Smad7 blocks transforming growth factor-beta signaling and fibrosis in rat remnant kidney. , 2005, The American journal of pathology.

[22]  T. Pawson,et al.  Deletion of Exon I of SMAD7 in Mice Results in Altered B Cell Responses , 2006, The Journal of Immunology.

[23]  Robert H. Jenkins,et al.  Loss of MicroRNA-192 promotes fibrogenesis in diabetic nephropathy. , 2010, Journal of the American Society of Nephrology : JASN.

[24]  K. Lai,et al.  Activation of p53 promotes renal injury in acute aristolochic acid nephropathy. , 2010, Journal of the American Society of Nephrology : JASN.

[25]  John J Rossi,et al.  MicroRNA-192 in diabetic kidney glomeruli and its function in TGF-β-induced collagen expression via inhibition of E-box repressors , 2007, Proceedings of the National Academy of Sciences.

[26]  L. Truong,et al.  Advanced glycation end products activate Smad signaling via TGF-beta-dependent and independent mechanisms: implications for diabetic renal and vascular disease. , 2004, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[27]  K. Lai,et al.  Mechanism of chronic aristolochic acid nephropathy: role of Smad3. , 2010, American journal of physiology. Renal physiology.

[28]  J. Zavadil,et al.  Transforming Growth Factor-β and microRNA:mRNA Regulatory Networks in Epithelial Plasticity , 2007, Cells Tissues Organs.

[29]  R. Kucherlapati,et al.  Functional Characterization of Transforming Growth Factor β Signaling in Smad2- and Smad3-deficient Fibroblasts* , 2001, The Journal of Biological Chemistry.

[30]  Mingyu Liang,et al.  MicroRNA-target pairs in the rat kidney identified by microRNA microarray, proteomic, and bioinformatic analysis. , 2008, Genome research.

[31]  Hong-Jian Zhu,et al.  Smad7 inhibits fibrotic effect of TGF-Beta on renal tubular epithelial cells by blocking Smad2 activation. , 2002, Journal of the American Society of Nephrology : JASN.

[32]  H. Schnaper,et al.  It's a Smad world: regulation of TGF-beta signaling in the kidney. , 2002, Journal of the American Society of Nephrology : JASN.

[33]  R. Morishita,et al.  Inhibition of renal fibrosis by gene transfer of inducible Smad7 using ultrasound-microbubble system in rat UUO model. , 2003, Journal of the American Society of Nephrology : JASN.

[34]  A. Roberts,et al.  Targeted disruption of TGF-beta1/Smad3 signaling protects against renal tubulointerstitial fibrosis induced by unilateral ureteral obstruction. , 2003, The Journal of clinical investigation.

[35]  Y. Liu,et al.  MicroRNA: a new frontier in kidney and blood pressure research. , 2009, American journal of physiology. Renal physiology.

[36]  J. Kopp,et al.  Advanced glycation end-products induce tubular CTGF via TGF-beta-independent Smad3 signaling. , 2010, Journal of the American Society of Nephrology : JASN.

[37]  K. Lai,et al.  Mice overexpressing latent TGF-beta1 are protected against renal fibrosis in obstructive kidney disease. , 2008, American journal of physiology. Renal physiology.

[38]  Xin Zhang,et al.  p53-Responsive micrornas 192 and 215 are capable of inducing cell cycle arrest. , 2008, Cancer research.

[39]  Bo Song,et al.  miR-192 Regulates Dihydrofolate Reductase and Cellular Proliferation through the p53-microRNA Circuit , 2008, Clinical Cancer Research.

[40]  M. Kitagawa,et al.  Down-regulation of Smad7 expression by ubiquitin-dependent degradation contributes to renal fibrosis in obstructive nephropathy in mice. , 2004, Proceedings of the National Academy of Sciences of the United States of America.

[41]  Gang Wang,et al.  Intrarenal expression of microRNAs in patients with IgA nephropathy , 2010, Laboratory Investigation.