# Mechanistic Roles of Adrenomedullin and its Signaling Receptors in Experimental Bronchopulmonary Dysplasia and Pulmonary Hypertension

> **NIH NIH R01** · BAYLOR COLLEGE OF MEDICINE · 2022 · $396,250

## Abstract

Abstract/Summary
Bronchopulmonary dysplasia (BPD) is the most common chronic lung disease of preterm infants; development
of pulmonary hypertension (PH) in these infants increases BPD-associated mortality and morbidity. Interrupted
angiogenesis and alveolarization, endothelial cell dysfunction, and pulmonary vascular remodeling contribute
to the pathogenesis of BPD and PH, a disease for which there are no specific therapies. Adrenomedullin (AM)
is an endogenous peptide that regulates angiogenesis and endothelial cell survival and function, making this
peptide an ideal target to develop therapies for this disease. AM signals through its cognate receptors,
calcitonin-receptor like receptor (Calcrl) and receptor activity-modifying protein (RAMP)-2. Recent studies
indicate that AM signaling is necessary for lung development and to ameliorate lung injury in neonatal rodents.
However, it is unclear if AM improves BPD-associated lung and pulmonary vascular dysfunction in these
animals. Further, the cellular and molecular mechanisms by which AM signaling protects against neonatal lung
injury are unknown. So, we propose to address these knowledge gaps using an established neonatal mouse
model of hyperoxic lung injury. Our preliminary studies indicate that AM signaling is necessary for healthy lung
development and to mitigate hyperoxia-induced lung injury in neonatal mice. Further, we observed that AM
regulates extracellular signal-regulated kinase (ERK) 1/2 activation and endothelial nitric oxide synthase
(eNOS) expression in the lungs of neonatal mice and in fetal human pulmonary endothelial cells. Based on
these data, we will test the central hypothesis that endothelial-specific AM signaling activates ERK 1/2 and
eNOS to promote angiogenesis and prevent endothelial cell dysfunction in neonatal lungs, which in turn will
mitigate hyperoxia-induced experimental BPD and PH. We will use a unique combination of molecular, cellular,
functional, and translational approaches to test this hypothesis. In Aim 1, we will use transgenic mice to
determine if endothelial-specific AM signaling is necessary and sufficient to protect neonatal mice against
hyperoxia-induced lung and pulmonary vascular injury and dysfunction. In Aim 2, we will use double transgenic
mice to examine the interactions between AM, ERK 1/2 signaling, and eNOS activity in the developing lungs
exposed to hyperoxia. Aim 3, which has two sub-aims, is designed to examine the translational potential of our
proposal. In sub-aim 1, we will examine if AM signaling regulates hyperoxia-induced injury in human pulmonary
endothelial cells. In sub-aim 2, we will determine the expression of AM and its receptors in the lungs of infants
with and without BPD. We expect that successful completion of these studies would provide a mechanistic
rationale for targeting AM, Calcrl, or RAMP2 to develop meaningful therapies for BPD and PH. Further, these
studies could provide a scientific premise for clinical trials with A...

## Key facts

- **NIH application ID:** 10458644
- **Project number:** 5R01HL139594-05
- **Recipient organization:** BAYLOR COLLEGE OF MEDICINE
- **Principal Investigator:** Binoy Shivanna
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $396,250
- **Award type:** 5
- **Project period:** 2018-09-01 → 2023-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10458644

## Citation

> US National Institutes of Health, RePORTER application 10458644, Mechanistic Roles of Adrenomedullin and its Signaling Receptors in Experimental Bronchopulmonary Dysplasia and Pulmonary Hypertension (5R01HL139594-05). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10458644. Licensed CC0.

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