# Six Hundred and Sixty Nanometer Light Exposure‐Induced Alterations in Actin Filament, Mitochondrial Morphological Dynamics, and Migration in Mesenchymal Stem Cells

## TL;DR

Exposure to 660 nm light enhances migration and alters actin and mitochondrial structures in stem cells, potentially improving stem cell therapies.

## Contribution

This study reveals novel effects of 660 nm light on actin filaments, mitochondrial dynamics, and migration in mesenchymal stem cells.

## Key findings

- 660 nm light exposure induces rapid actin fiber rearrangement and mitochondrial granulation in mesenchymal stem cells.
- The treatment enhances cell migration, proliferation, ATP, and ROS levels in human adipose-derived mesenchymal stem cells.
- These findings suggest new mechanistic insights for improving stem cell homing and migration through photobiomodulation.

## Abstract

Actin cytoskeleton alteration and cell homing/migration are crucial determinants for the success of stem cell (SC) based therapy. Photobiomodulation (PBM) is a promising non‐pharmacological approach for modulating SC potency. Though ~660 nm is the most studied wavelength for the proliferation/differentiation of SCs, the migration and cytoskeleton remodeling aspects have not been investigated in detail. In this study, we report the effect of ~660 nm on actin filaments, mitochondrial morphological dynamics, along with the migration of human adipose‐derived mesenchymal stem cells (hADMSCs). Exposure to ~660 nm (~15 J/cm2) elicits rapid actin fiber rearrangement leading to elongated, parallel fibers, and mitochondrial granulation along the leading edge of cell migration. In addition, 660 nm (~15 J/cm2) also enhances cell proliferation, ATP, and ROS levels. These ultrastructural and biochemical alterations, in conjunction with the increased cell migration, shed new light on mechanistic perspectives to elicit enhanced homing/migration in SCs and would help in further optimization of ~660 nm based SC priming.

Six hundred and sixty nanometer light‐induced alteration of actin filament cytoskeleton, mitochondrial morphological dynamics, and enhanced migration in adipose‐derived mesenchymal stem cells.