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BioMed Research International
Volume 2015, Article ID 783538, 13 pages
http://dx.doi.org/10.1155/2015/783538
Research Article

Paricalcitol Inhibits Aldosterone-Induced Proinflammatory Factors by Modulating Epidermal Growth Factor Receptor Pathway in Cultured Tubular Epithelial Cells

1Cellular Biology in Renal Diseases Laboratory, IIS-Fundación Jimenez Diaz, Universidad Autónoma Madrid (UAM), 28040 Madrid, Spain
2REDINREN, Madrid, Spain
3Department of Experimental Nephrology, Universitat de Lleida/Institut de Recerca Biomèdica de Lleida, 25198 Lleida, Spain
4Dialysis Unit, IIS-Fundación Jiménez Díaz, School of Medicine, UAM, Madrid, Spain
5Institute of Renal Research Queen Sophia (IRSIN), Spain
6Division of Nephrology and Hypertension, IIS-Fundación Jiménez Díaz, UAM, Madrid, Spain
7Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Spain

Received 31 October 2014; Accepted 11 January 2015

Academic Editor: Luca De Nicola

Copyright © 2015 Jose L. Morgado-Pascual et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Chronic kidney disease is characterized by Vitamin D deficiency and activation of the renin-angiotensin-aldosterone system. Increasing data show that vitamin D receptor agonists (VDRAs) exert beneficial effects in renal disease and possess anti-inflammatory properties, but the underlying mechanism remains unknown. Emerging evidence suggests that “a disintegrin and metalloproteinase” (ADAM)/epidermal growth factor receptor (EGFR) signalling axis contributes to renal damage. Aldosterone induces EGFR transactivation regulating several processes including cell proliferation and fibrosis. However, data on tubular epithelial cells is scarce. We have found that, in cultured tubular epithelial cells, aldosterone induced EGFR transactivation via TGF-α/ADAM17. Blockade of the TGF-α/ADAM17/EGFR pathway inhibited aldosterone-induced proinflammatory gene upregulation. Moreover, among the potential downstream mechanisms, we found that TGF-α/ADAM17/EGFR inhibition blocked ERK and STAT-1 activation in response to aldosterone. Next, we investigated the involvement of TGF-α/ADAM17/EGFR axis in VDRA anti-inflammatory effects. Preincubation with the VDRA paricalcitol inhibited aldosterone-induced EGFR transactivation, TGF-α/ADAM-17 gene upregulation, and downstream mechanisms, including proinflammatory factors overexpression. In conclusion, our data suggest that the anti-inflammatory actions of paricalcitol in tubular cells could depend on the inhibition of TGF-α/ADAM17/EGFR pathway in response to aldosterone, showing an important mechanism of VDRAs action.