title: Attenuation of leukocyte recruitment via CXCR1/2 inhibition stops the progression of PAH in mice with genetic ablation of endothelial BMPR-II.
abstract: Previous studies from our group have demonstrated that bone morphogenetic protein receptor-II (BMPR-II), expressed on pulmonary artery endothelial cells, imparts profound anti-inflammatory effects by regulating the release of proinflammatory cytokines and promoting barrier function by suppressing the transmigration of leukocytes into the pulmonary vessel wall. Here we demonstrate that, in mice with endothelial-specific loss of BMPR-II expression (L1Cre(+);Bmpr2(f/f)), reduction in barrier function and the resultant pulmonary hypertension observed in vivo are the result of increased leukocyte recruitment through increased CXCR1/2 signaling. Loss of endothelial expressed BMPR-II leads to elevated plasma levels of a wide range of soluble mediators important in regulating leukocyte migration and extravasation, including the CXCR1/2 ligand, KC. Treatment of L1Cre(+);Bmpr2(f/f) mice with the CXCR1/2 antagonist SCH527123 inhibits leukocyte transmigration into lung and subsequently reverses the pulmonary hypertension. Our data have uncovered a previously unrecognized regulatory function of BMPR-II, which acts to regulate the expression of CXCR2 on endothelial cells, suggesting that increased CXCR2 signaling may also be a feature of the human pathology and that CXCR1/2 pathway antagonists may represent a novel therapeutic approach for treating pulmonary hypertension because of defects in BMPR-II expression.
authors: Novartis Institutes for BioMedical Research, West Sussex, UK. victoria.burton@novartis.com
authors: Victoria J
authors: VJ
authors: Burton
authors: Alan M
authors: AM
authors: Holmes
authors: Loredana I
authors: LI
authors: Ciuclan
authors: Alexander
authors: A
authors: Robinson
authors: Jan S
authors: JS
authors: Roger
authors: Gabor
authors: G
authors: Jarai
authors: Andrew C
authors: AC
authors: Pearce
authors: David C
authors: DC
authors: Budd
mesh_terms: D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology / Q000627:therapeutic use; D001549:Benzamides / Q000494:pharmacology / Q000627:therapeutic use*; D052006:Bone Morphogenetic Protein Receptors, Type II / Q000235:genetics* / Q000502:physiology; D002478:Cells, Cultured; D002634:Chemotaxis, Leukocyte / Q000187:drug effects* / Q000235:genetics*; D003503:Cyclobutanes / Q000494:pharmacology / Q000627:therapeutic use*; D004195:Disease Models, Animal; D018450:Disease Progression; D015536:Down-Regulation / Q000235:genetics; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D017353:Gene Deletion; D006801:Humans; D006976:Hypertension, Pulmonary / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D051379:Mice; D008822:Mice, Transgenic; D009928:Organ Specificity / Q000187:drug effects / Q000235:genetics; D011651:Pulmonary Artery / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D023062:Receptors, Interleukin-8A / Q000037:antagonists & inhibitors*; D023063:Receptors, Interleukin-8B / Q000037:antagonists & inhibitors*
chemical_list: C516686:2-hydroxy-N,N-dimethyl-3-(2-((1-(5-methylfuran-2-yl)propyl)amino)-3,4-dioxocyclobut-1-enylamino)benzamide; D000959:Antihypertensive Agents; D001549:Benzamides; D003503:Cyclobutanes; D023062:Receptors, Interleukin-8A; D023063:Receptors, Interleukin-8B; D052006:Bone Morphogenetic Protein Receptors, Type II