PM2.5 exposure aggravates left heart failure induced pulmonary hypertension

Area of Science:

• Cardiovascular Research
• Environmental Health
• Pulmonary Medicine

Background:

• Particulate matter 2.5 (PM2.5) is a known cardiovascular risk factor.
• Left ventricular (LV) failure can lead to pulmonary arterial hypertension (PAH).

Purpose of the Study:

• To investigate the impact of PM2.5 exposure on a murine model of PAH induced by LV failure.
• To determine if PM2.5 exacerbates cardiac and pulmonary remodeling in this model.

Main Methods:

• C57BL/6 mice were subjected to sham surgery or transverse aortic constriction (TAC) to induce LV failure.
• Mice were exposed to PM2.5 or filtered air.
• Evaluated cardiac and lung function, RV and lung remodeling, and fibrotic markers.

Main Results:

• PM2.5 exposure significantly worsened PAH in TAC mice, indicated by increased right ventricular systolic blood pressure (RVSBP), cardiomyocyte size, and RV/lung fibrosis.
• Upregulated expression of collagen III and TGF-β1 in lung tissue was observed in PM2.5-exposed TAC mice.
• PM2.5 alone did not induce significant cardiac or pulmonary pathology in sham-operated mice.

Conclusions:

• PM2.5 exposure exacerbates the progression of PAH in the setting of LV failure.
• Environmental pollutants like PM2.5 pose a significant threat to cardiovascular health, particularly in individuals with pre-existing heart conditions.