title: The renin inhibitor aliskiren attenuates high-glucose induced extracellular matrix synthesis and prevents apoptosis in cultured podocytes.
abstract: OBJECTIVE
  Altered extracellular matrix (ECM) remodeling and podocyte apoptosis are characteristic features of diabetic nephropathy (DN). Aliskiren (ALI) inhibits the renin-catalyzed conversion of angiotensinogen to angiotensin I. This study tested ALI's effect on podocyte ECM accretion and survival in a high-glucose environment in vitro.
  
  
  METHODS
  Conditionally immortalized mouse podocytes were incubated in normal glucose (NG; 5.5 mM) or high glucose (HG; 40 mM) for 24-48 h with and without ALI (20 nM). Real-time RT-PCR was performed for fibronectin (FN), collagen α5(type IV) (Cola5IV), matrix metalloproteinases 2 and 9 (MMP2 and MMP9), and tissue inhibitor of metalloproteinases 1 and 2 (TIMP1 and TIMP2). Western blots were performed for FN, Cola5IV, MMP2, MMP9, TIMP1 and cleaved (activated) caspase-3.
  
  
  RESULTS
  ALI significantly reduced the mRNA and protein levels of FN, Cola5IV and TIMP1, and the mRNA of TIMP2 and cleaved caspase-3. ALI had no effect on MMP2 mRNA or protein or MMP9 mRNA tested under HG conditions. Under NG conditions, ALI had no effect on FN, Cola5IV, MMP2, MMP9 and activated caspase-3 proteins. ALI decreased the activated caspase-3 protein and evidence of apoptosis by TUNEL staining observed in podocytes cultured under HG conditions.
  
  
  CONCLUSIONS
  These results show for the first time that renin inhibition with ALI mitigates the profibrotic and apoptotic effects of HG in cultured podocytes. These data strengthen the therapeutic rationale for renin inhibition with ALI beyond its hemodynamic effects.
authors.affiliation: Division of Nephrology, Los Angeles Biomedical Research Institute/Harbor-UCLA Medical Center, Torrance, CA 90502, USA.
authors.forename: Lynetta M
authors.initials: LM
authors.lastname: Phillips
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Tiane
authors.initials: T
authors.lastname: Dai
authors.forename: David L
authors.initials: DL
authors.lastname: Feldman
authors.forename: Janine
authors.initials: J
authors.lastname: LaPage
authors.forename: Sharon G
authors.initials: SG
authors.lastname: Adler
mesh_terms: D000577:Amides / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002478:Cells, Cultured; D024141:Collagen Type IV / Q000187:drug effects; D003928:Diabetic Nephropathies / Q000503:physiopathology; D005109:Extracellular Matrix / Q000378:metabolism*; D005353:Fibronectins / Q000187:drug effects; D005650:Fumarates / Q000494:pharmacology*; D005947:Glucose / Q000494:pharmacology*; D020782:Matrix Metalloproteinases / Q000096:biosynthesis; D050199:Podocytes / Q000187:drug effects* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D000092502:Renin Inhibitors
chemical_list: D000577:Amides; D024141:Collagen Type IV; D005353:Fibronectins; D005650:Fumarates; D005947:Glucose; D020782:Matrix Metalloproteinases; D012333:RNA, Messenger; D000092502:Renin Inhibitors; C446481:aliskiren