Table of Contents
ISRN Cell Biology
Volume 2012, Article ID 295341, 6 pages
http://dx.doi.org/10.5402/2012/295341
Research Article

Biological Effects of Phosphate on Fibroblast-Like Synoviocytes

Department of Orthopaedic Surgery, Carolinas Medical Center, P.O. Box 32681, Charlotte, NC 28232, USA

Received 17 October 2011; Accepted 10 November 2011

Academic Editor: A. Chiarini

Copyright © 2012 Yubo Sun 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

This study sought to examine the expression of genes implicated in phosphate transport and pathological calcification in osteoarthritis (OA) and rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS) and investigate the biological effects of phosphate. Results revealed that several genes, which were implicated in phosphate transport and pathological calcification, were differentially expressed in OA FLS and RA FLS. Phosphate stimulated the expression of matrix metalloproteinse-1, matrix metalloproteinse-3, cyclooxygenase-2, and interleukin-1β in a dose-dependent manner. Phosphate also induced OA FLS cell death but not RA FLS cell death at higher concentration. Calcification inhibitors, phosphocitrate (PC), and ethane-1-hydroxy-1,1-diphosphonate (EHDP), effectively inhibited these detrimental biological effects of phosphate. These findings suggest that abnormal expression of genes implicated in phosphate transport and pathological calcification may contribute to the progression of OA through the induction of extracellular matrix-degrading enzymes, proinflammatory cytokines, cell death, and calcium deposits. Calcification inhibitors such as PC and EHDP are potent inhibitors of these detrimental biological effects of phosphate.