Spironolactone ameliorates PIT1-dependent vascular osteoinduction in klotho-hypomorphic mice

J Clin Invest. 2013 Feb;123(2):812-22. doi: 10.1172/JCI64093. Epub 2013 Jan 9.

Abstract

Klotho is a potent regulator of 1,25-hydroxyvitamin D3 [1,25(OH)2D3] formation and calcium-phosphate metabolism. Klotho-hypomorphic mice (kl/kl mice) suffer from severe growth deficits, rapid aging, hyperphosphatemia, hyperaldosteronism, and extensive vascular and soft tissue calcification. Sequelae of klotho deficiency are similar to those of end-stage renal disease. We show here that the mineralocorticoid receptor antagonist spironolactone reduced vascular and soft tissue calcification and increased the life span of kl/kl mice, without significant effects on 1,25(OH)2D3, FGF23, calcium, and phosphate plasma concentrations. Spironolactone also reduced the expression of osteoinductive Pit1 and Tnfa mRNA, osteogenic transcription factors, and alkaline phosphatase (Alpl) in calcified tissues of kl/kl mice. In human aortic smooth muscle cells (HAoSMCs), aldosterone dose-dependently increased PIT1 mRNA expression, an effect paralleled by increased expression of osteogenic transcription factors and enhanced ALP activity. The effects of aldosterone were reversed by both spironolactone treatment and PIT1 silencing and were mitigated by FGF23 cotreatment in HAoSMCs. In conclusion, aldosterone contributes to vascular and soft tissue calcification, an effect due, at least in part, to stimulation of spironolactone-sensitive, PIT1-dependent osteoinductive signaling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aldosterone / pharmacology
  • Animals
  • Cell Differentiation / drug effects
  • Cells, Cultured
  • Fibroblast Growth Factors / metabolism
  • Glucuronidase / deficiency*
  • Glucuronidase / genetics
  • Humans
  • Mice
  • Mice, Knockout
  • Osteoblasts / drug effects
  • Osteoblasts / metabolism
  • Osteoblasts / pathology
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Renal Insufficiency, Chronic / complications
  • Renal Insufficiency, Chronic / metabolism
  • Renal Insufficiency, Chronic / pathology
  • Signal Transduction / drug effects
  • Spironolactone / pharmacology*
  • Transcription Factor Pit-1 / genetics
  • Transcription Factor Pit-1 / metabolism*
  • Vascular Calcification / etiology
  • Vascular Calcification / metabolism
  • Vascular Calcification / pathology
  • Vascular Calcification / prevention & control*

Substances

  • POU1F1 protein, human
  • Pit1 protein, mouse
  • RNA, Messenger
  • Transcription Factor Pit-1
  • Spironolactone
  • Aldosterone
  • Fibroblast Growth Factors
  • fibroblast growth factor 23
  • Glucuronidase
  • klotho protein