title: Regulation of podoplanin expression by microRNA-29b associates with its antiapoptotic effect in angiotensin II-induced injury of human podocytes.
abstract: BACKGROUND
  Angiotensin (Ang)II is involved in induction of proteinuria, renal injury, and apoptosis and thus a major contributor to the development of chronic kidney disease. Podocytes are of major importance for the pathogenesis of several kidney diseases. Decrease of podoplanin (PDPN) in podocytes and podocyte loss has been associated with the development of proteinuria. Little is known about the regulation and biological function of PDPN in podocytes and its role in AngII-mediated kidney damage. Here, we determined the influence of AngII on the expression of PDPN, microRNA (miRNA)-29b and miRNA-497 in human podocytes. Further, we analyzed the impact of small interfering RNA-mediated downregulation of PDPN on AngII-induced apoptosis and viability. Moreover, we characterized the role of miRNA-29b and miRNA-497 in expression regulation of PDPN.
  
  
  METHODS
  Cell viability and apoptosis were determined by functional assays. Expression analyses were done via Real-Time PCR and western blot analyses. Dual luciferase assay was performed to characterize miRNA-mediated expression control.
  
  
  RESULTS
  AngII increased the expression of miRNA-29b and reduced PDPN. Small interfering RNA-mediated downregulation of PDPN increased proapoptotic caspase-3 activation and cytochrome C translocation, whereas cell viability and Akt phosphorylation were reduced in AngII-stimulated podocytes. In contrast to miRNA-497, transfection of cells with miRNA-29b mimics significantly decreased PDPN. Cotransfection of cells with miRNA-29b and a dual luciferase reporter vector decreased the luciferase activity compared with controls.
  
  
  CONCLUSIONS
  These data demonstrate the posttranscriptional control of PDPN expression by miRNA-29b and support a role of PDPN as an antiapoptotic prosurvival factor in AngII-induced injury of human podocytes.
authors: Institut für Klinische Pharmakologie und Toxikologie, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors: Andreas
authors: A
authors: Eisenreich
authors: Sebastian
authors: S
authors: Langer
authors: Laura
authors: L
authors: Herlan
authors: Reinhold
authors: R
authors: Kreutz
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D053148:Caspase 3 / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D045304:Cytochromes c / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D035683:MicroRNAs / Q000235:genetics*; D010766:Phosphorylation / Q000187:drug effects; D050199:Podocytes / Q000187:drug effects* / Q000378:metabolism; D011507:Proteinuria / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D014162:Transfection; D014662:Vasoconstrictor Agents / Q000494:pharmacology*; D000098853:Podoplanin
chemical_list: D000804:Angiotensin II; D053148:Caspase 3; D045304:Cytochromes c; D008562:Membrane Glycoproteins; D035683:MicroRNAs; D051057:Proto-Oncogene Proteins c-akt; D034741:RNA, Small Interfering; D014662:Vasoconstrictor Agents; C532045:MIRN29a microRNA, human; C559640:MIRN497 microRNA, human; C117468:PDPN protein, human; D000098853:Podoplanin