Gaofeng Zhao1, Jingjing Seng2, John Beagle3, Olga Syrkina3, Charles A Hales4. 1. Pulmonary and Critical Care Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Department of Surgery, First Affiliated Hospital, Zhengzhou University, Zhengzhou, Henan, China. 2. Department of Surgery, First Affiliated Hospital, Zhengzhou University, Zhengzhou, Henan, China; Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts. 3. Pulmonary and Critical Care Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts. 4. Pulmonary and Critical Care Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts. Electronic address: chales@partners.org.
Abstract
BACKGROUND: Artery remodeling is the principal change of pulmonary artery hypertension. Heparin has been shown to inhibit vascular smooth muscle cell proliferation. We hypothesized that heparin may modulate vascular remodeling in pulmonary artery hypertension, and explored the mechanism. METHODS: A localized overcirculation-induced artery remodeling was created in piglets by anastomosing the left lower lobe pulmonary artery (LLLPA) to the thoracic aortic artery. Piglets were treated with heparin or saline for 4 weeks. Hemodynamic data were collected, and histology of the lung was assessed. We investigated the expressions of several candidate genes in lung and further observed the involvement of P38 mitogen-activated protein kinases (MAPK). The effects of heparin on the growth of cultured pulmonary arterial vascular smooth muscle cell and P38 MAPK expression were further determined under various conditions. RESULTS: Four weeks after the shunt setup, overcirculation caused significant LLLPA remodeling, pressure increase, and pulmonary vascular resistance increase, and LLLPA flow reduction compared with that immediately after the shunt setup. Heparin reduced the LLLPA remodeling, pressure, and pulmonary vascular resistance, and increased the LLLPA flow compared with that not heparin treated. Shunt and heparin treatment did not change the piglet's systemic hemodynamics. Shunt increased the expression of P38 MAPK and heparin decreased its expression in the shunted LLLPA. Both heparin and P38 MAPK inhibitor suppressed VSMC growth and P38 MAPK expression in the cultured VSMC, but they did not present additive effects when the two treatments were combined. CONCLUSIONS: Heparin reduces overcirculation-induced pulmonary artery remodeling through a P38 MAPK-dependent pathway.
BACKGROUND: Artery remodeling is the principal change of pulmonary artery hypertension. Heparin has been shown to inhibit vascular smooth muscle cell proliferation. We hypothesized that heparin may modulate vascular remodeling in pulmonary artery hypertension, and explored the mechanism. METHODS: A localized overcirculation-induced artery remodeling was created in piglets by anastomosing the left lower lobe pulmonary artery (LLLPA) to the thoracic aortic artery. Piglets were treated with heparin or saline for 4 weeks. Hemodynamic data were collected, and histology of the lung was assessed. We investigated the expressions of several candidate genes in lung and further observed the involvement of P38 mitogen-activated protein kinases (MAPK). The effects of heparin on the growth of cultured pulmonary arterial vascular smooth muscle cell and P38 MAPK expression were further determined under various conditions. RESULTS: Four weeks after the shunt setup, overcirculation caused significant LLLPA remodeling, pressure increase, and pulmonary vascular resistance increase, and LLLPA flow reduction compared with that immediately after the shunt setup. Heparin reduced the LLLPA remodeling, pressure, and pulmonary vascular resistance, and increased the LLLPA flow compared with that not heparin treated. Shunt and heparin treatment did not change the piglet's systemic hemodynamics. Shunt increased the expression of P38 MAPK and heparin decreased its expression in the shunted LLLPA. Both heparin and P38 MAPK inhibitor suppressed VSMC growth and P38 MAPK expression in the cultured VSMC, but they did not present additive effects when the two treatments were combined. CONCLUSIONS:Heparin reduces overcirculation-induced pulmonary artery remodeling through a P38 MAPK-dependent pathway.
Authors: Sarah Cullivan; Claire A Murphy; Luisa Weiss; Shane P Comer; Barry Kevane; Brian McCullagh; Patricia B Maguire; Fionnuala Ní Ainle; Sean P Gaine Journal: Pulm Circ Date: 2021-06-04 Impact factor: 3.017