Magnetically Stimulated Myogenesis Recruits a CRY2-TRPC1 Photosensitive Signaling Axis

Abstract

Overview

The cryptochromes are flavoproteins that either individually or synergistically respond to light and magnetic field directionality. They are also implicated in circadian rhythm entrainment and development. This study investigates the effects of single brief exposures (10 min) to low energy (1.5 mT) pulsed electromagnetic fields (PEMFs) on myogenesis, focusing on the TRPC1-mediated Ca2+ entry pathway. Notably, downwardly directed fields produced greater myogenic enhancement than upwardly directed fields.

Findings

• Growth in the dark causes myoblasts to lose sensitivity to both magnetic field exposure and directionality.
• Overexpressing or silencing cryptochrome circadian regulator 2 (CRY2) in myoblasts either enhances or reduces PEMF responses, respectively, when under ambient light.
• Reducing cellular flavin adenine dinucleotide (FAD) by silencing riboflavin kinase (RFK) impairs the response to PEMFs and disrupts selectivity for magnetic field direction.
• The typical upregulation of TRPC1 and cell cycle regulatory proteins in response to PEMF exposure is diminished by upwardly directed fields, darkness, magnetic shielding, or silencing CRY2 or RFK.
• A physical interaction between CRY2 and TRPC1 was identified, and their co-translocation into the nucleus following PEMF exposure was observed.

Conclusion

These results identify CRY2 as a key part of a TRPC1-dependent magnetotransduction cascade regulating myogenesis in response to electromagnetic fields. Notably, the study reinforces the biological connection—and health relevance—of electromagnetic field exposure, demonstrating that both light and magnetic field parameters critically direct biological processes at the cellular level.