Pharmacological characterization of P2X₁ and P2X₃ purinergic receptors in bovine chondrocytes

详细信息    查看全文

• 作者：K. Varani ; M. De Mattei ; F. Vincenzi ; A. Tosi ; S. Gessi ; S. Merighi ; A. Pellati ; F. Masieri ; A. Ongaro ; P.A. Borea
• 关键词：Purinergic receptors ; Chondrocytes ; Binding assays ; NO production ; PGE₂ release
• 刊名：Osteoarthritis and Cartilage
• 出版年：2008
• 出版时间：November 2008
• 年：2008
• 卷：16
• 期：11
• 页码：1421-1429
• 全文大小：461 K

文摘

Summary

Objective

The aim of the present study is that of characterizing, for the first time in a quantitative way, from a biochemical, physico chemical and functional point of view P2X₁ and P2X₃ purinergic receptors in bovine chondrocytes. The affinity and the potency of typical purinergic ligands were studied through competition binding experiments and their role in modulating chondrocyte actvities was investigated by analyzing nitric oxide (NO) and prostaglandin E2 (PGE₂) release.

Methods

Saturation, competition binding experiments, western blotting and immunohistochemistry assays on the P2X₁ and P2X₃ purinergic receptors in bovine chondrocytes were performed. Thermodynamic analysis of the P2X₁ and P2X₃ purinergic binding was studied to investigate the forces driving drug-receptor coupling. In the functional assays (NO and PGE₂ release) the potency of purinergic agonists and antagonists was evaluated.

Results

Bovine chondrocytes expressed P2X₁ and P2X₃ purinergic receptors and thermodynamic parameters indicated that purinergic binding is enthalpy- and entropy-driven for agonists and totally entropy-driven for antagonists. Typical purinergic agonists such as adenosine 5′-triphosphate (ATP) and α,β-methyleneATP were able to increase NO and PGE₂ release. A purinergic antagonist, A317491, was able to block the stimulatory effect on functional experiments mediated by the agonists.

Conclusions

These data demonstrate for the first time the presence of functional P2X₁ and P2X₃ purinergic receptors in bovine chondrocytes. Agonists and antagonists are thermodynamically discriminated and are able to modulate functional responses such as NO and PGE₂ release. These results suggest the potential role of novel purinergic antagonists in the treatment of pathophysiological diseases linked to the inflammation and involved in articular cartilage resorption.