ABSTRACT
Title
Expression and function of the P2X7 purinergic receptor in peripheral blood mononuclear cells from patients with Behçet’s disease
Authors
Castrichini M1, Lazzerini PE1, Capecchi PL1, Franceschini R2, Gamberucci A3, Hammoud M4, Moramarco A2, Natale M1, Gianchecchi E1, Montilli C1, Ricci G1, Zimbone S1, Galeazzi M4, Laghi-Pasini F1.
1Dept. of Clinical Medicine and Immunological Sciences, Section of Clinical Immunology; 2Dept. of Ophthalmology and NeuroSurgery; 3Dept. of Pathophysiology, Experimental medicine, and Public Health; 4Dept. of Clinical Medicine and Immunological Sciences, Section of Rheumatology. University of Siena, Siena, Italy.
1Dept. of Clinical Medicine and Immunological Sciences, Section of Clinical Immunology; 2Dept. of Ophthalmology and NeuroSurgery; 3Dept. of Pathophysiology, Experimental medicine, and Public Health; 4Dept. of Clinical Medicine and Immunological Sciences, Section of Rheumatology. University of Siena, Siena, Italy.
Abstract
Background. P2X7 receptor is a nucleotide-gated ion channel chiefly involved in the inflammatory response triggered by passive release of ATP from damaged cells. It is largely expressed in monocytes and plays a key role in promoting the release of pro-inflammatory cytokines, particularly IL-1β [1,2]. Behçet’s disease (BD) is a systemic immune-inflammatory disorder of unknown origin whose clinical manifestations include oral and genital ulcers, skin lesions, uveitis and arthritis [3]. Since innate immunity activation and IL-1β release seem to play a relevant role in BD, we hypothesized a P2X7 involvement in the pathogenesis of the disease.
On this basis, we evaluated the expression and function of P2X7 receptor in the peripheral blood mononuclear cells (PBMC) from BD patients.
Methods. PBMC, or isolated monocytes, were prepared from 18 BD patients and 17 healthy controls matched for age and sex. In these cells we evaluated: (i) P2X7 expression (by flow cytometry), and (ii) function, induced by P2X7 receptor stimulation,as determined bycytosolic free Ca2+ fluxes measurements (by single-cell fluorescent microscopy), IL-1β release (by ELISA test), and apoptosis induction (by flow cytometry).
Results.In BD monocytes P2X7expression, and the amount of Ca2+ influx, induced by the selective P2X7 receptor agonist 2’-3’-O-(4-benzoylbenzoyl)ATP (BzATP) were higher than in monocytes from healthy controls. Moreover, in BD patients BzATPstimulation significantly enhanced the release of IL-1β from lipopolysaccharides (LPS)-primed monocytes, and promoted apoptosis in PBMC.
Conclusions. Our results provide evidence that in PBMCs from BD patients both the expression and the function of the purinergic P2X7 receptor are increased with respect to healthy controls. These data, suggesting the putative involvement of this pathway in the pathogenesis of the immuno-inflammatory activation underlying BD, may designate the P2X7 receptor as a new potential therapeutic target of the disease.
[1] Di Virgilio F (2007) - Trends Pharmacol Sci 28: 465-472.
[2] Caporali F (2008) - J Mol Med 86: 937-949.
[3] Yurdakul S (2004) - Curr Opin Rheumatol 16:38-42.
On this basis, we evaluated the expression and function of P2X7 receptor in the peripheral blood mononuclear cells (PBMC) from BD patients.
Methods. PBMC, or isolated monocytes, were prepared from 18 BD patients and 17 healthy controls matched for age and sex. In these cells we evaluated: (i) P2X7 expression (by flow cytometry), and (ii) function, induced by P2X7 receptor stimulation,as determined bycytosolic free Ca2+ fluxes measurements (by single-cell fluorescent microscopy), IL-1β release (by ELISA test), and apoptosis induction (by flow cytometry).
Results.In BD monocytes P2X7expression, and the amount of Ca2+ influx, induced by the selective P2X7 receptor agonist 2’-3’-O-(4-benzoylbenzoyl)ATP (BzATP) were higher than in monocytes from healthy controls. Moreover, in BD patients BzATPstimulation significantly enhanced the release of IL-1β from lipopolysaccharides (LPS)-primed monocytes, and promoted apoptosis in PBMC.
Conclusions. Our results provide evidence that in PBMCs from BD patients both the expression and the function of the purinergic P2X7 receptor are increased with respect to healthy controls. These data, suggesting the putative involvement of this pathway in the pathogenesis of the immuno-inflammatory activation underlying BD, may designate the P2X7 receptor as a new potential therapeutic target of the disease.
[1] Di Virgilio F (2007) - Trends Pharmacol Sci 28: 465-472.
[2] Caporali F (2008) - J Mol Med 86: 937-949.
[3] Yurdakul S (2004) - Curr Opin Rheumatol 16:38-42.