Blockade of Wnt/β-catenin signaling by paricalcitol ameliorates proteinuria and kidney injury

J Am Soc Nephrol. 2011 Jan;22(1):90-103. doi: 10.1681/ASN.2009121236. Epub 2010 Oct 28.

Abstract

Recent studies implicate Wnt/β-catenin signaling in podocyte dysfunction. Because vitamin D analogs can inhibit β-catenin in other tissues, we tested whether the vitamin D analog paricalcitol could ameliorate podocyte injury, proteinuria, and renal fibrosis in adriamycin (ADR) nephropathy. Compared with vehicle-treated controls, paricalcitol preserved expression of nephrin, podocin, and WT1; prevented proteinuria; and reduced glomerulosclerotic lesions induced by ADR. Paricalcitol also inhibited expression of proinflammatory cytokines, reduced renal infiltration of monocytes/macrophages, hampered activation of renal myofibroblasts, and suppressed expression of the fibrogenic TGF-β1, CTGF, fibronectin, and types I and III collagen. Selective suppression of renal Wnt4, Wnt7a, Wnt7b, and Wnt10a expression after ADR accompanied these renoprotective effects of paricalcitol. Significant upregulation of β-catenin, predominantly in podocytes and tubular epithelial cells, accompanied renal injury; paricalcitol largely abolished this induction of renal β-catenin and inhibited renal expression of Snail, a downstream effector of Wnt/β-catenin signaling. Administration of paricalcitol also ameliorated established proteinuria. In vitro, paricalcitol induced a physical interaction between the vitamin D receptor and β-catenin in podocytes, which led to suppression of β-catenin-mediated gene transcription. In summary, these findings suggest that paricalcitol prevents podocyte dysfunction, proteinuria, and kidney injury in adriamycin nephropathy by inhibiting Wnt/β-catenin signaling.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Kidney Injury / chemically induced
  • Acute Kidney Injury / pathology
  • Acute Kidney Injury / prevention & control*
  • Animals
  • Disease Models, Animal
  • Doxorubicin / adverse effects
  • Ergocalciferols / pharmacology*
  • Glomerular Mesangium / drug effects
  • Glomerular Mesangium / pathology
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Podocytes / drug effects
  • Podocytes / metabolism
  • Podocytes / pathology
  • Proteinuria / prevention & control*
  • Signal Transduction / drug effects*
  • Signal Transduction / physiology
  • Vitamin D / analogs & derivatives*
  • Wnt Proteins / antagonists & inhibitors*
  • Wnt Proteins / metabolism
  • beta Catenin / antagonists & inhibitors*
  • beta Catenin / metabolism

Substances

  • Ergocalciferols
  • Wnt Proteins
  • beta Catenin
  • Vitamin D
  • paricalcitol
  • Doxorubicin