Functional and molecular factors associated with TAPSE in hypoxic pulmonary hypertension.
Adaptation of the right ventricle (RV) to increased afterload is crucial for survival in pulmonary hypertension (PH), but it is challenging to assess RV function and identify associated molecular mechanisms. The aim of the current study was to analyze the relationship between invasive and noninvasive parameters of RV morphology and function and associated molecular changes. The response of mice to normobaric hypoxia was assessed by hechocardiography, invasive hemodynamics, and histological and molecular analyses. Plasma levels of possibly novel markers of RV remodeling were measured by ELISA in patients with idiopathic pulmonary arterial hypertension (IPAH) and matched healthy controls. Chronic hypoxia-induced PH was accompanied by significantly decreased tricuspid annular plane systolic excursion (TAPSE) and unchanged RV contractility index and tau. RV hypertrophy was present without an increase in fibrosis. There was no change in α- and β-major histocompatibility class or natriuretic peptides expression. Comparative microarray analysis identified two soluble factors, fibroblast growth factor-5 (FGF5) and interleukin-22 receptor alpha-2 (IL22RA2), as being possibly associated with RV remodeling. We observed significantly higher plasma levels of IL22RA2, but not FGF5, in patients with IPAH. Hypoxic pulmonary hypertension in a stage of RV remodeling with preserved systolic function is associated with decreased pulmonary vascular compliance, mild diastolic RV dysfunction, and significant decrease in TAPSE. Subtle gene expression changes in the RV vs. the left ventricle upon chronic hypoxia suggest that the majority of changes are due to hypoxia and not due to changes in afterload. Increased IL22RA2 levels might represent a novel RV adaptive mechanism.
Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria; Department of Experimental Anaesthesiology, Medical University of Graz, Graz, Austria.
Slaven
0000-0002-0820-3318
S
Crnkovic
Division of Cardiology, Department of Internal Medicine, Medical University of Graz, Graz, Austria;
Albrecht
A
Schmidt
Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria;
Bakytbek
B
Egemnazarov
Department of Internal Medicine, Justus-Liebig-University Giessen, Universities of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany;
Jochen
J
Wilhelm
Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria;
Leigh M
LM
Marsh
Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria; Department of Thoracic Surgery, Medical University of Vienna/Vienna General Hospital, Vienna, Austria;
Bahil
B
Ghanim
Department of Thoracic Surgery, Medical University of Vienna/Vienna General Hospital, Vienna, Austria;
Walter
W
Klepetko
Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria; Department of Experimental Anaesthesiology, Medical University of Graz, Graz, Austria.
Andrea
A
Olschewski
Division of Pulmonology, Department of Internal Medicine, Medical University of Graz, Graz, Austria; and horst.olschewski@medunigraz.at.
Horst
H
Olschewski
Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria; Department of Experimental Anaesthesiology, Medical University of Graz, Graz, Austria.
Grazyna
G
Kwapiszewska
D000818:Animals; D015687:Cell Hypoxia; D006352:Heart Ventricles / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D006976:Hypertension, Pulmonary / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology*; D017380:Hypertrophy, Right Ventricular / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D018123:Receptors, Interleukin / Q000097:blood; D059467:Transcriptome; D014261:Tricuspid Valve / Q000473:pathology*; D016278:Ventricular Function, Right; D020257:Ventricular Remodeling
C433253:IL22RA2 protein, human; D009124:Muscle Proteins; D018123:Receptors, Interleukin
IL22RA2; TAPSE; hypoxia; pulmonary hypertension