Pregnancy-driven cardiovascular maternal miR-29 plasticity in obesity

Area of Science:

• Cardiovascular Science
• Reproductive Biology
• Molecular Biology

Background:

• Maternal obesity is linked to cardiovascular disorders in mothers and fetuses.
• MicroRNA-29 (miR-29) family and its target molecules are implicated in cardiovascular system (CVS) regulation.
• Pregnancy typically influences CVS miR-29 concentrations, but this adaptation may be altered by obesity.

Purpose of the Study:

• To evaluate maternal CVS expression of the miR-29 family in pregnant obese (POb) versus pregnant non-obese (PnOb) baboons.
• To test the hypothesis that miR-29 concentrations increase during pregnancy but decrease in maternal obesity.
• To investigate the relationship between miR-29 and its target molecules, such as elastin (ELN), in the context of maternal obesity.

Main Methods:

• A comparative study involving non-pregnant, POb, and PnOb baboons (n=4 each).
• Collection of maternal left ventricle (LV), left atrium (LA), and aortic arch (AA) tissues at the end of gestation.
• Quantification of miR-29 (a, b, c) expression and ELN mRNA levels in collected tissues.

Main Results:

• Left atrial (LA) miR-29 (a, c) expression was significantly higher in PnOb compared to POb baboons.
• In the left ventricle (LV), miR-29b expression showed a trend towards lower levels in PnOb animals (P=.059).
• A positive correlation was observed between ELN mRNA expression and miR-29b levels in the aortic arch (AA) (r=.76, P=.03).

Conclusions:

• Maternal obesity impairs the normal adaptation of miR-29 levels during pregnancy.
• Reduced miR-29 expression in maternal obesity may contribute to cardiovascular complications.
• Targeting miR-29 pharmacologically presents a potential strategy for managing and preventing complications associated with maternal obesity.