Fibroblast-Specific <i>β</i>-catenin Signaling Dictates the Outcome of AKI.
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| Abstract |    :  
                  AKI is a devastating condition with high morbidity and mortality. The pathologic features of AKI are characterized by tubular injury, inflammation, and vascular impairment. Whether fibroblasts in the renal interstitium have a role in the pathogenesis of AKI is unknown. In this study, we investigated the role of fibroblast-specific β-catenin signaling in dictating the outcome of AKI, using conditional knockout mice in which β-catenin was specifically ablated in fibroblasts (Gli1-β-cat-/-). After ischemia-reperfusion injury (IRI), Gli1-β-cat-/- mice had lower serum creatinine levels and less morphologic injury than Gli1-β-cat+/+ littermate controls. Moreover, we detected fewer apoptotic cells, as well as decreased cytochrome C release; reduced expression of Bax, FasL, and p53; and increased phosphorylation of Akt, in the Gli1-β-cat-/- kidneys. Gli1-β-cat-/- kidneys also exhibited upregulated expression of proliferating cell nuclear antigen and Ki-67, which are markers of cell proliferation. Furthermore, Gli1-β-cat-/- kidneys displayed suppressed NF-κB signaling and cytokine expression and reduced infiltration of inflammatory cells. Notably, loss of β-catenin in fibroblasts induced renal expression of hepatocyte growth factor (HGF) and augmented the tyrosine phosphorylation of c-met receptor after IRI. In vitro, treatment with Wnt ligands or ectopic expression of active β-catenin inhibited HGF mRNA and protein expression and repressed HGF promoter activity. Collectively, these results suggest that fibroblast-specific β-catenin signaling can control tubular injury and repair in AKI by modulating HGF expression. Our studies uncover a previously unrecognized role for interstitial fibroblasts in the pathogenesis of AKI.  | 
        
| Year of Publication |    :  
                  2018 
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| Journal |    :  
                  Journal of the American Society of Nephrology : JASN 
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| Date Published |    :  
                  2018 
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| ISSN Number |    :  
                  1046-6673 
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| URL |    :  
                  http://jasn.asnjournals.org/cgi/pmidlookup?view=long&pmid=29343518 
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| DOI |    :  
                  10.1681/ASN.2017080903 
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| Short Title |    :  
                  J Am Soc Nephrol 
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