Intense light therapy was found to reduce right ventricular remodeling and dysfunction caused by prolonged hypoxic exposure in mice, according to an April 10 study published in Genes & Diseases. The research was conducted by scientists from the Army Medical University, Key Laboratory of Geriatric Cardiovascular and Cerebrovascular Diseases, and Key Laboratory of Extreme Environmental Medicine.
The findings are significant because right ventricular changes due to low oxygen conditions are common in chronic lung disease and high-altitude environments. These changes can lead to impaired cardiac function and increased inflammation.
Researchers divided mice into groups exposed to either normal or low-oxygen conditions, with some receiving intense light intervention. Assessments showed that while hypoxia led to marked heart dysfunction and structural changes, intense light significantly reduced these effects. The treated mice had improved heart function, less hypertrophy, lower pulmonary artery pressures, and decreased collagen buildup compared to those under normal lighting conditions during hypoxia.
Further analysis at the single-cell level revealed that hypoxia increased inflammatory macrophages in the heart tissue. Intense light exposure shifted these immune cells toward a more protective state by reducing damaging cytokines such as TNF-α and IL-6. The study identified platelet factor 4 (PF4), a chemokine produced by macrophages, as being elevated during hypoxia but suppressed with intense light treatment. Reducing PF4+ macrophages correlated directly with better heart outcomes.
Advanced analysis showed that macrophages shifted toward an inflammatory state during hypoxia but were redirected away from this path with intense light therapy. This suggests that targeting PF4+ resident macrophages could be important for future treatments of cardiac issues related to low oxygen levels.
The authors concluded that "this study reveals intense light therapy as a novel, noninvasive approach that mitigates hypoxia-induced RV remodeling and dysfunction by suppressing macrophage-associated inflammation." They suggest their findings may offer new avenues for treating similar cardiac problems.
