TY - JOUR
T1 - Endothelin-1 activation of the endothelin B receptor modulates pulmonary endothelial CX3CL1 and contributes to pulmonary angiogenesis in experimental hepatopulmonary syndrome
AU - Zhang, Junlan
AU - Yang, Wenli
AU - Hu, Bingqian
AU - Wu, Wei
AU - Fallon, Michael B.
PY - 2014/6
Y1 - 2014/6
N2 - Hepatic production and release of endothelin-1 (ET-1) binding to endothelin B (ETB) receptors, overexpressed in the lung microvasculature, is associated with accumulation of pro-angiogenic monocytes and vascular remodeling in experimental hepatopulmonary syndrome (HPS) after common bile duct ligation (CBDL). We have recently found that lung vascular monocyte adhesion and angiogenesis in HPS involve interaction of endothelial C-X3-C motif ligand 1 (CX3CL1) with monocyte CX3C chemokine receptor 1 (CX3CR1), although whether ET-1/ETB receptor activation influences these events is unknown. Our aim was to define if ET-1/ETB receptor activation modulates CX3CL1/CX3CR1 signaling and lung angiogenesis in experimental HPS. A selective ETB receptor antagonist, BQ788, was given for 2 weeks to 1-week CBDL rats. ET-1 (±BQ788) was given to cultured rat pulmonary microvascular endothelial cells overexpressing ETB receptors. BQ788 treatment significantly decreased lung angiogenesis, monocyte accumulation, and CX3CL1 levels after CBDL. ET-1 treatment significantly induced CX3CL1 production in lung microvascular endothelial cells, which was blocked by inhibitors of Ca 2+ and mitogen-activated protein kinase (MEK)/ERK pathways. ET-1-induced ERK activation was Ca2+ independent. ET-1 administration also increased endothelial tube formation in vitro, which was inhibited by BQ788 or by blocking Ca2+ and MEK/ERK activation. CX3CR1 neutralizing antibody partially inhibited ET-1 effects on tube formation. These findings identify a novel mechanistic interaction between the ET-1/ETB receptor axis and CX3CL1/CX3CR1 in mediating pulmonary angiogenesis and vascular monocyte accumulation in experimental HPS.
AB - Hepatic production and release of endothelin-1 (ET-1) binding to endothelin B (ETB) receptors, overexpressed in the lung microvasculature, is associated with accumulation of pro-angiogenic monocytes and vascular remodeling in experimental hepatopulmonary syndrome (HPS) after common bile duct ligation (CBDL). We have recently found that lung vascular monocyte adhesion and angiogenesis in HPS involve interaction of endothelial C-X3-C motif ligand 1 (CX3CL1) with monocyte CX3C chemokine receptor 1 (CX3CR1), although whether ET-1/ETB receptor activation influences these events is unknown. Our aim was to define if ET-1/ETB receptor activation modulates CX3CL1/CX3CR1 signaling and lung angiogenesis in experimental HPS. A selective ETB receptor antagonist, BQ788, was given for 2 weeks to 1-week CBDL rats. ET-1 (±BQ788) was given to cultured rat pulmonary microvascular endothelial cells overexpressing ETB receptors. BQ788 treatment significantly decreased lung angiogenesis, monocyte accumulation, and CX3CL1 levels after CBDL. ET-1 treatment significantly induced CX3CL1 production in lung microvascular endothelial cells, which was blocked by inhibitors of Ca 2+ and mitogen-activated protein kinase (MEK)/ERK pathways. ET-1-induced ERK activation was Ca2+ independent. ET-1 administration also increased endothelial tube formation in vitro, which was inhibited by BQ788 or by blocking Ca2+ and MEK/ERK activation. CX3CR1 neutralizing antibody partially inhibited ET-1 effects on tube formation. These findings identify a novel mechanistic interaction between the ET-1/ETB receptor axis and CX3CL1/CX3CR1 in mediating pulmonary angiogenesis and vascular monocyte accumulation in experimental HPS.
UR - http://www.scopus.com/inward/record.url?scp=84901006367&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84901006367&partnerID=8YFLogxK
U2 - 10.1016/j.ajpath.2014.02.027
DO - 10.1016/j.ajpath.2014.02.027
M3 - Article
C2 - 24731444
AN - SCOPUS:84901006367
SN - 0002-9440
VL - 184
SP - 1706
EP - 1714
JO - American Journal of Pathology
JF - American Journal of Pathology
IS - 6
ER -