TY - JOUR
T1 - Role of HIF-1 in proton-mediated CXCR4 down-regulation in endothelial cells
AU - Melchionna, Roberta
AU - Romani, Marta
AU - Ambrosino, Valeria
AU - D'Arcangelo, Daniela
AU - Cencioni, Chiara
AU - Porcelli, Daniele
AU - Toietta, Gabriele
AU - Truffa, Silvia
AU - Gaetano, Carlo
AU - Mangoni, Antonella
AU - Pozzoli, Ombretta
AU - Cappuzzello, Claudia
AU - Capogrossi, Maurizio C.
AU - Napolitano, Monica
PY - 2010/5
Y1 - 2010/5
N2 - AimsAcidification is associated with a variety of pathological and physiological conditions. In the present study, we aimed at investigating whether acidic pH may regulate endothelial cell (EC) functions via the chemokine receptor CXCR4, a key modulator of EC biological activities.Methods and resultsExposure of ECs to acidic pH reversibly inhibited mRNA and protein CXCR4 expression, CXCL12/stromal cell-derived factor (SDF)-1-driven EC chemotaxis in vitro, and CXCR4 expression and activation in vivo in a mouse model. Further, CXCR4 signalling impaired acidosis-induced rescue from apoptosis in ECs. The inhibition of CXCR4 expression occurred transcriptionally and was hypoxia-inducible factor (HIF)-1-dependent as demonstrated by both HIF-1 and HIF-1 dominant negative overexpression, by HIF-1 silencing, and by targeted mutation of the-29 to-25 hypoxia response element (HRE) in the-357/-59 CXCR4 promoter fragment. Moreover, chromatin immunoprecipitation (ChIP) analysis showed endogenous HIF-1 binding to the CXCR4 promoter that was enhanced by acidification.ConclusionThe results of the present study identify CXCR4 as a key player in the EC response to acidic pH and show, for the first time, that HRE may function not only as an effector of hypoxia, but also as an acidosis response element, and raise the possibility that this may constitute a more general mechanism of transcriptional regulation at acidic pH.
AB - AimsAcidification is associated with a variety of pathological and physiological conditions. In the present study, we aimed at investigating whether acidic pH may regulate endothelial cell (EC) functions via the chemokine receptor CXCR4, a key modulator of EC biological activities.Methods and resultsExposure of ECs to acidic pH reversibly inhibited mRNA and protein CXCR4 expression, CXCL12/stromal cell-derived factor (SDF)-1-driven EC chemotaxis in vitro, and CXCR4 expression and activation in vivo in a mouse model. Further, CXCR4 signalling impaired acidosis-induced rescue from apoptosis in ECs. The inhibition of CXCR4 expression occurred transcriptionally and was hypoxia-inducible factor (HIF)-1-dependent as demonstrated by both HIF-1 and HIF-1 dominant negative overexpression, by HIF-1 silencing, and by targeted mutation of the-29 to-25 hypoxia response element (HRE) in the-357/-59 CXCR4 promoter fragment. Moreover, chromatin immunoprecipitation (ChIP) analysis showed endogenous HIF-1 binding to the CXCR4 promoter that was enhanced by acidification.ConclusionThe results of the present study identify CXCR4 as a key player in the EC response to acidic pH and show, for the first time, that HRE may function not only as an effector of hypoxia, but also as an acidosis response element, and raise the possibility that this may constitute a more general mechanism of transcriptional regulation at acidic pH.
KW - Acidosis
KW - Chemokine
KW - HIF-1
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U2 - 10.1093/cvr/cvp393
DO - 10.1093/cvr/cvp393
M3 - Article
C2 - 20007689
AN - SCOPUS:77951687021
VL - 86
SP - 293
EP - 301
JO - Cardiovascular Research
JF - Cardiovascular Research
SN - 0008-6363
IS - 2
ER -