Light Emitting Diodes Irradiation Regulates miRNA-877-3p to Promote Cardiomyocyte Proliferation

Area of Science:

• Cardiovascular Biology
• Regenerative Medicine
• Biophotonics

Background:

• Mammalian cardiomyocytes have limited self-renewal capacity in adulthood.
• Myocardial repair after injury necessitates strategies to induce cardiomyocyte proliferation.
• Photobiomodulation (PBM) offers a non-invasive method to modulate cellular functions.

Purpose of the Study:

• To investigate the effect of conditioned photobiomodulation using 630 nm red light-emitting diodes (LED-Red) on neonatal cardiomyocyte proliferation.
• To elucidate the molecular mechanisms underlying LED-Red-induced cardiomyocyte proliferation, focusing on microRNA and gene expression.

Main Methods:

• Neonatal cardiomyocytes were irradiated with conditioned LED-Red (630 nm).
• MicroRNA (miR-877-3p) expression levels were analyzed.
• GADD45g gene expression and its role as a target of miR-877-3p were investigated.
• Cell proliferation assays were performed with and without miR-877-3p silencing or GADD45g siRNA.

Main Results:

• LED-Red irradiation significantly promoted neonatal cardiomyocyte proliferation.
• LED-Red irradiation increased the expression of miR-877-3p.
• Silencing miR-877-3p partially reversed the pro-proliferative effect of LED-Red.
• GADD45g was identified as a downstream target of miR-877-3p, and its expression was inhibited by LED-Red.
• GADD45g knockdown reversed the pro-proliferative effects of LED-Red.

Conclusions:

• Conditioned LED-Red irradiation enhances neonatal cardiomyocyte proliferation.
• This effect is mediated through the upregulation of miR-877-3p and subsequent downregulation of its target gene, GADD45g.
• LED-Red PBM presents a promising therapeutic avenue for myocardial repair after injury.