ABSTRACT
Different wavelengths emitted from light-emitting diodes (LEDs) are known as an influential factor in proliferation and differentiation of various cell types. Since human umbilical cord matrix-derived mesenchymal cells (hUCMs) are ideal tools for human regenerative medicine clinical trials and stem cell researches, in the present study we investigated the neurogenesis effects of single and intermittent green and red LED irradiation on hUCM cells. Exposure of hUCMs to single and intermittent green (530 nm, 1.59 J/cm2) and red (630 nm, 0.318 J/cm2) lights significantly increased the expression of specific genes including nestin, ß-tubulin III and Olig2. Additionally, immunocytochemical analysis confirmed the expression of specific neural-related proteins including nestin, ß-tubulin III, Olig2 and GFAP. Also, alternating exposure of hUCM cells to green and red lights increased the expression of some neural markers more than either light alone. Further research are required to develop the application of LED irradiation as a useful tool for therapeutic purposes including neural repair and regeneration.
Subject(s)
Cell Differentiation , Mesenchymal Stem Cells , Neurogenesis , Umbilical Cord , Humans , Mesenchymal Stem Cells/radiation effects , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/metabolism , Cell Differentiation/radiation effects , Umbilical Cord/cytology , Neurogenesis/radiation effects , Light , Nestin/metabolism , Nestin/genetics , Cells, Cultured , Neurons/radiation effects , Neurons/metabolism , Neurons/cytology , Tubulin/metabolism , Tubulin/genetics , Oligodendrocyte Transcription Factor 2/metabolism , Oligodendrocyte Transcription Factor 2/geneticsABSTRACT
Alteration of the proliferation rate and differentiation of mesenchymal stem cells (MSCs) into various lineages, including neural cells, by light emitting diodes (LEDs) irradiation has received considerable attention in recent years. Human umbilical cord matrix-derived mesenchymal cells (hUCMs) are an accessible source of adult stem cells with appropriate characteristics that make them ideal tools for stem cell researches, cell therapy procedures and regenerative medicine. The aim of the present study was to investigate the effects of green LED irradiation, retinoic acid (RA) and their combination on the differentiation of hUCMs into neural lineage as well as the mechanisms involved. Exposure of hUCMs to green LED (530 nm, 1.59 J/cm2) with or without retinoic acid (RA) treatment, significantly increased the expression of specific genes including nestin, ß-tubulin III, MAP2 and Olig2. In addition, immunohistochemical analysis confirmed expression of specific neural-related proteins including MAP2, GFAP and Olig2 in irradiated cells. ROS generation significantly increased following green light irradiation which in turn has activated the MAPK signaling pathway, resulting in the differentiation of hUCMs into neurons and glial cells, confirmed by western blot analysis of MAPK-related pathway. Taken together, our results suggest that the green LED irradiation, alone and in combination with RA, via ERK 1/2, JNK and p38 phosphorylation improves differentiation of hUCMs into neural lineage. Other mechanisms and inducers to enhance differentiation phenomena in vitro and in vivo should be investigated to determine the most appropriate strategy for therapeutic purposes.