A potential role of the GRO-α/CXCR2 system in Sjögren's syndrome: regulatory effects of pro-inflammatory cytokines.
Chemokines, small pro-inflammatory cytokines, are involved in migration of inflammatory cells in inflamed tissues and recent studies established their role in angiogenesis, hematopoiesis, cancer and autoimmune conditions. Growth related oncogene-alpha (GRO-α), a member of the CXC chemokine family, and its receptor CXCR2 are involved in the inflammatory processes. Since there is no previous report that supports a possible role of GRO-α/CXCR2 receptor complex during inflammation and neovascularization existing in the autoimmune disease Sjögren's syndrome (SS), in this study, we examined CXCR2 and its ligand GRO-α expression in SS tissues. Immunohistochemistry revealed that GRO-α and its receptor CXCR2 were expressed at high levels in diseased tissues compared to healthy controls. In addition, human salivary gland epithelial cells (SGEC) cultures were submitted to a pro-inflammatory microenvironment using cytokines IL-6 and TNF-α in order to demonstrate that CXCR2 may change its initial expression pattern to another under inflammatory condition. The data show an increased expression of CXCR2 depending on the inflammatory cytokine used in culture in a time-dependent manner. Furthermore, silencing of the pro-angiogenic chemokine GRO-α is proportionally correlated with decreased expression of CXCR2 in pro-inflammatory cytokine-stimulated SGEC indicating the GRO-α/CXCR2 complex as a novel therapeutic target for the chronic inflammatory disease Sjögren's syndrome.
Department of Basic Medical Sciences, Section of Human Anatomy and Histology, Laboratory of Cell Biology, University of Bari Medical School, piazza Giulio Cesare 1, 70124 Bari, Italy. sabrina.lisi@uniba.it
Sabrina
S
Lisi
Margherita
M
Sisto
Dario Domenico
DD
Lofrumento
Massimo
M
D'Amore
Raffaella
R
De Lucro
Domenico
D
Ribatti
D000328:Adult; D000368:Aged; D002478:Cells, Cultured; D054360:Chemokine CXCL1 / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism*; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D023063:Receptors, Interleukin-8B / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D012859:Sjogren's Syndrome / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism*
C475829:CXCL1 protein, human; D054360:Chemokine CXCL1; D016207:Cytokines; D018836:Inflammation Mediators; D023063:Receptors, Interleukin-8B; D011994:Recombinant Proteins