Effect of Intrauterine Smoke Exposure on microRNA-15a Expression in Human Lung Development and Subsequent Asthma Risk

Area of Science:

• Developmental Biology
• Genetics
• Immunology

Background:

• In utero smoke (IUS) exposure is a known risk factor for asthma.
• Understanding the molecular mechanisms linking IUS exposure to asthma is crucial.

Purpose of the Study:

• To investigate if changes in microRNA (miRNA) expression due to IUS exposure during human fetal lung development are associated with asthma susceptibility.
• To identify specific miRNAs and their gene targets involved in this process.

Main Methods:

• Gene expression profiling of human fetal lung tissues from IUS-exposed and unexposed groups.
• Differential expression analysis of miRNAs based on post-conception age and IUS exposure.
• Correlation analysis between IUS-associated miRNAs and their gene expression targets.
• Validation in a mouse model and association studies with asthma exacerbations in human cohorts.

Main Results:

• Five miRNAs showed differential expression across post-conception age, with two also differing by IUS exposure in fetal lungs.
• MiR-15a was significantly altered by developmental stage, IUS exposure in fetal lungs, and in postnatal mouse lungs.
• MiR-15a was associated with the intrauterine expression of the asthma gene GSDMB and with asthma exacerbations in a human cohort.

Conclusions:

• MiR-15a is expressed during human lung development, is affected by IUS exposure, and regulates intrauterine expression of asthma-related genes.
• These findings support a role for miR-15a in the fetal origins of asthma, highlighting its potential as a biomarker or therapeutic target.