Compromised Cardiopulmonary Function in Fibulin-5 Deficient Mice

Area of Science:

• Cardiovascular Biology
• Pulmonary Medicine
• Connective Tissue Biology

Background:

• Elastic fibers, composed of elastin and associated glycoproteins, are crucial for lung and right heart function.
• Elastopathies, diseases affecting elastic fibers, require robust murine models to understand elastin's role.
• Fibulin-5 is an elastin-associated glycoprotein vital for elastic fiber assembly and function.

Purpose of the Study:

• To investigate the impact of fibulin-5 deficiency on lung and pulmonary arterial structure, function, and mechanics.
• To assess right heart function in fibulin-5 deficient mice.
• To elucidate the specific roles of fibulin-5 in maintaining pulmonary and cardiovascular integrity.

Main Methods:

• Quantification of lung and pulmonary arterial structure, function, and mechanics in fibulin-5 deficient mice.
• Biaxial mechanical testing of pulmonary arteries.
• Histological analysis of elastic fiber content and lamellar integrity.
• Echocardiographic assessment of right ventricular function.

Main Results:

• Fibulin-5 deficiency resulted in increased lung compliance and alveolar disruption.
• Pulmonary arteries showed decreased elastic energy storage capacity and wall stress, linked to reduced elastic fiber content and fragmented laminae.
• Sex differences were observed in compromised right ventricular function in fibulin-5 deficient mice.

Conclusions:

• Fibulin-5 deficiency compromises right heart function and alters lung parenchyma and pulmonary artery mechanics.
• Elastic fiber dysfunction has opposing effects on lung compliance (increased) and pulmonary artery distensibility (decreased).
• Fibulin-5 deficient mice serve as a valuable model for studying elastin's role in pulmonary and cardiovascular diseases.