Effects of cognate, non-cognate and synthetic CXCR4 and ACKR3 ligands on human lung endothelial cell barrier function Journal Article


Authors: Cheng, Y. H.; Eby, J. M.; LaPorte, H. M.; Volkman, B. F.; Majetschak, M
Article Title: Effects of cognate, non-cognate and synthetic CXCR4 and ACKR3 ligands on human lung endothelial cell barrier function
Abstract: Recent evidence suggests that chemokine CXCL12, the cognate agonist of chemokine receptors CXCR4 and ACKR3, reduces thrombin-mediated impairment of endothelial barrier function. A detailed characterization of the effects of CXCL12 on thrombin-mediated human lung endothelial hyperpermeability is lacking and structure-function correlations are not available. Furthermore, effects of other CXCR4/ACKR3 ligands on lung endothelial barrier function are unknown. Thus, we tested the effects of a panel of CXCR4/ACKR3 ligands (CXCL12, CXCL11, ubiquitin, AMD3100, TC14012) and compared the CXCR4/ACKR3 activities of CXCL12 variants (CXCL12alpha/beta, CXCL12(3-68), CXCL121, CXCL122, CXCL12-S-S4V, CXCL12-R47E, CXCL12-K27A/R41A/R47A) with their effects on human lung endothelial barrier function in permeability assays. CXCL12alpha enhanced human primary pulmonary artery endothelial cell (hPPAEC) barrier function, whereas CXCL11, ubiquitin, AMD3100 and TC14012 were ineffective. Pre-treatment of hPPAEC with CXCL12alpha and ubiquitin reduced thrombin-mediated hyperpermeability. CXCL12alpha-treatment of hPPAEC after thrombin exposure reduced barrier function impairment by 70% (EC50 0.05-0.5nM), which could be antagonized with AMD3100; ubiquitin (0.03-3muM) was ineffective. In a human lung microvascular endothelial cell line (HULEC5a), CXCL12alpha and ubiquitin post-treatment attenuated thrombin-induced hyperpermeability to a similar degree. CXCL12(3-68) was inefficient to activate CXCR4 in Presto-Tango beta-arrestin2 recruitment assays; CXCL12-S-S4V, CXCL12-R47E and CXCL12-K27A/R41A/R47A showed significantly reduced potencies to activate CXCR4. While the potencies of all proteins in ACKR3 Presto-Tango assays were comparable, the efficacy of CXCL12(3-68) to activate ACKR3 was significantly reduced. The potencies to attenuate thrombin-mediated hPPAEC barrier function impairment were: CXCL12alpha/beta, CXCL121, CXCL12-K27A/R41A/R47A gt; CXCL12-S-S4V, CXCL12-R47E gt; CXCL122 gt; CXCL12(3-68). Our findings indicate that CXCR4 activation attenuates thrombin-induced lung endothelial barrier function impairment and suggest that protective effects of CXCL12 are dictated by its CXCR4 agonist activity and interactions of distinct protein moieties with heparan sulfate on the endothelial surface. These data may facilitate development of compounds with improved pharmacological properties to attenuate thrombin-induced vascular leakage in the pulmonary circulation.
Journal Title: PloS one
Volume: 12
Issue: 11
ISSN: 1932-6203; 1932-6203
Publisher: Unknown  
Journal Place: United States
Date Published: 2017
Start Page: e0187949
Language: eng
DOI/URL:
Notes: LR: 20171219; GR: R01 GM107495/GM/NIGMS NIH HHS/United States; JID: 101285081; 0 (CXCR4 protein, human); 0 (CXCR7 protein, human); 0 (Ligands); 0 (Receptors, CXCR); 0 (Receptors, CXCR4); 2017/09/19 00:00 [received]; 2017/10/28 00:00 [accepted]; 2017/11/11 06:00 [entrez]; 2017/11/11 06:00 [pubmed]; 2017/12/05 06:00 [medline]; epublish