Adrenomedullin Overexpression Protects Mice from Experimental Bronchopulmonary Dysplasia and Associated Pulmonary Hypertension

Shyam Thapa, Poonam Sarkar, M. Waleed Gaber, Roberto Barrios, Madhulata Chauhan, Chandrasekhar Yallampalli, Binoy Shivanna
Texas Children’s Hospital and Baylor College of Medicine. Houston Methodist Hospital
United States

American Journal of Physiology Lung Cellular and Molecular Physiology
Am J Physiol Lung Cell Mol Physiol 2025;
DOI: 10.1152/ajplung.00234.2025

Abstract
Bronchopulmonary dysplasia (BPD) associated pulmonary hypertension (PH) or BPD-PH is a lung disease of infants with significant morbidity. Adrenomedullin (Adm) is an angiogenic peptide that signals through calcitonin receptor-like receptor (Calcrl) and receptor activity modifying protein 2 (RAMP2). Adm deficiency potentiates hyperoxia-induced experimental BPD-PH in mice; however, whether Adm overexpression can mitigate this lung disease is unclear. Thus, we tested the hypothesis that Adm overexpression attenuates hyperoxia (HO)-induced murine experimental BPD-PH by using a novel transgenic mouse that overexpresses Adm globally (Admhi/hi mice). One-day-old Admhi/hi mice or their wild-type littermates (Adm+/+ mice) were exposed to HO (FiO2 70%) for 14 d and allowed to recover in normoxia (NO, FiO2 21%) for an additional 14 d. Controls were maintained in NO for 28 d. On postnatal day (P) 14, we harvested the lungs to determine the extent of Adm expression and apoptosis. On P28, we quantified alveolarization, lung vascularization, and PH. HO-exposed Adm+/+ mice demonstrated increased lung apoptosis, decreased alveolarization and lung vascularization, and indices of PH, indicating that neonatal HO exposure causes BPD-PH. However, Adm overexpression attenuated experimental BPD-PH, as evident by the decreased extent of hyperoxia-induced lung apoptosis and inflammation, alveolar and vascular simplification, pulmonary vascular remodeling, and PH in Admhi/hi mice than in Adm+/+ mice. Collectively, our results demonstrate that Adm overexpression attenuates HO-induced murine experimental BPD-PH, emphasizing the therapeutic potential of Adm for BPD-PH in preterm infants.

Category
Class III. Pulmonary Hypertension Associated with Lung Disease
Animal Models of Pulmonary Vascular Disease and Therapy
Genetic Factors Associated with Pulmonary Vascular Disease
Vascular Cell Biology and Mechanisms of Pulmonary Vascular Disease
Pulmonary Vascular Pathology

Age Focus: Pediatric Pulmonary Vascular Disease

Fresh or Filed Publication: Fresh (PHresh). Less than 1-2 years since publication

Article Access
Free PDF File or Full Text Article Available Through PubMed or DOI: Yes

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