Low level laser irradiation stimulates mitochondrial membrane potential and disperses subnuclear promyelocytic leukemia protein

• Published in: Lasers in surgery and medicine 2004-12, Vol.35 (5), p.369-376
• Main Authors: Gavish, Lilach, Asher, Yael, Becker, Yechiel, Kleinman, Yosef
• Format: Article
• Language: English
• Subjects: biostimulation; cell cycle; Cells, Cultured; cytokine; Cytokines - genetics; Gene Expression; Humans; keratinocyte; Keratinocytes; lasers; Low-Level Light Therapy; Membrane Potentials - radiation effects; Mitochondria - radiation effects; Neoplasm Proteins - radiation effects; Nuclear Proteins - radiation effects; photobiology; Promyelocytic Leukemia Protein; Transcription Factors - radiation effects; Tumor Suppressor Proteins
• ISSN: 0196-8092; 1096-9101
• DOI: 10.1002/lsm.20108

Background and Objectives Low level laser irradiation (LLLI) is used to promote wound healing. Molecularly it is known to stimulate mitochondrial membrane potential (MMP), cytokine secretion, and cell proliferation. This study was designed to determine the influence of LLLI on the kinetics of MMP stimulation and decay, specific cytokine gene expression, and subcellular localization of promyelocytic leukemia (PML) protein on HaCaT human keratinocytes. Study Design/Material and Methods The cells were irradiated by a 780 nm titanium–sapphire (Ti–Sa) laser with 2 J/cm2 energy density. MMP was monitored with Mitotracker, a mitochondrial voltage‐sensitive fluorescent dye. Cytokine gene expression was carried out using semi‐quantitative‐reverse transcription polymerase chain reaction. Subcellular localization of PML protein, a cell‐cycle checkpoint protein, was determined using immunofluorescent staining. Results The fluorescence intensity of MMP was increased immediately after the end of LLLI by 148 ± 6% over control (P