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

• Published in: The Journal of clinical investigation 2013-02, Vol.123 (2), p.812-822
• Main Authors: Voelkl, Jakob, Alesutan, Ioana, Leibrock, Christina B, Quintanilla-Martinez, Leticia, Kuhn, Volker, Feger, Martina, Mia, Sobuj, Ahmed, Mohamed S E, Rosenblatt, Kevin P, Kuro-O, Makoto, Lang, Florian
• Format: Article
• Language: English
• Subjects: Aldosterone - pharmacology; Animals; Biomedical research; Blood vessels; Calcification; Cell Differentiation - drug effects; Cells, Cultured; Fibroblast Growth Factors - metabolism; Glucuronidase - deficiency; Glucuronidase - genetics; Health aspects; Humans; Kidney diseases; Mice; Mice, Knockout; Mortality; Osteoblasts - drug effects; Osteoblasts - metabolism; Osteoblasts - pathology; Phosphatase; Physiological aspects; Plasma; Renal Insufficiency, Chronic - complications; Renal Insufficiency, Chronic - metabolism; Renal Insufficiency, Chronic - pathology; RNA, Messenger - genetics; RNA, Messenger - metabolism; Signal Transduction - drug effects; Smooth muscle; Spironolactone; Spironolactone - pharmacology; Transcription Factor Pit-1 - genetics; Transcription Factor Pit-1 - metabolism; Transcription factors; Vascular Calcification - etiology; Vascular Calcification - metabolism; Vascular Calcification - pathology; Vascular Calcification - prevention & control
• ISSN: 0021-9738; 1558-8238
• DOI: 10.1172/JCI64093

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.