Low-Level Laser Therapy (LLLT) in Dystrophin-Deficient Muscle Cells: Effects on Regeneration Capacity, Inflammation Response and Oxidative Stress

Abstract

The present study evaluated low-level laser therapy (LLLT) effects on some physiological pathways that may lead to muscle damage or regeneration capacity in dystrophin-deficient muscle cells of mdx mice, the experimental model of Duchenne muscular dystrophy (DMD). Primary cultures of mdx skeletal muscle cells were irradiated only one time with laser and analyzed after 24 and 48 hours. The LLLT parameter used was 830 nm wavelengths at 5 J/cm² fluence. The following groups were set up: Ctrl (untreated C57BL/10 primary muscle cells), mdx (untreated mdx primary muscle cells), mdx LA 24 (mdx primary muscle cells - LLLT irradiated and analyzed after 24 h), and mdx LA 48 (mdx primary muscle cells - LLLT irradiated and analyzed after 48 h). The mdx LA 24 and mdx LA 48 groups showed significant increase in cell proliferation, higher diameter in muscle cells and decreased MyoD levels compared to the mdx group. The mdx LA 48 group showed significant increase in Myosin Heavy Chain levels compared to the untreated mdx and mdx LA 24 groups. The mdx LA 24 and mdx LA 48 groups showed significant increase in [Ca2+]i. The mdx group showed significant increase in H2O2 production and 4-HNE levels compared to the Ctrl group and LLLT treatment reduced this increase. GSH levels and GPx, GR and SOD activities increased in the mdx group. Laser treatment reduced the GSH levels and GR and SOD activities in dystrophic muscle cells. The mdx group showed significant increase in the TNF-α and NF-κB levels, which in turn was reduced by the LLLT treatment. Together, these results suggest that the laser treatment improved regenerative capacity and decreased inflammatory response and oxidative stress in dystrophic muscle cells, indicating that LLLT could be a helpful alternative therapy to be associated with other treatment for dystrophinopathies.

The role of oxidative stress in skeletal muscle injury and regeneration: focus on antioxidant enzymes

“…Prevention of pathology in dystrophin deficient mice by application of different antioxidants has been recently intensively investigated and reviewed (Hnia et al 2008 ; Kim et al 2013 ; Kim and Lawler 2012 ; Messina et al 2009 ; Nakae et al 2012 ; Whitehead et al 2008 ). The favourable effects in modulating the oxidative stress were also achieved by low-level laser therapy which decreased ROS and increased activity of antioxidant enzymes such as SOD, CAT and GPX (Leal Junior et al 2010 ; Macedo et al 2015 ). Additionally, the low-intensity endurance exercise has beneficial influence on skeletal muscle of mdx mice.…”

Low-level laser therapy (LLLT) accelerates the sternomastoid muscle regeneration process after myonecrosis due to bupivacaine

“…Pires et al [73] studied tendinitis in rats after 7 and 14 days and they showed that LLLT reduced the TNF-α expression only at chronic phase. Macedo et al [74] studying dystrophic muscle cells verified that LLLT treatment reduced the TNF-α and NF-κB levels. Mantineo et al [75] utilized LLLT at five frequencies (5, 25, 50, 100, and 200 Hz) for treating inflammation induced in the gastrocnemius muscle and the treatment effects occurred for all doses with a reduction of TNF-α, IL-1β, IL-6 cytokines and inflammatory cells.…”

GaAs laser therapy reestablishes the morphology of the NMJ and nAChRs after injury due to bupivacaine

“…The use of LLLT increases neovascularization [65] and the expression of growth factors [66] and decreases oxidative stress, inflammation [67] and myonecrosis, activating precursor cells of myogenesis (satellite cells) [32]. Studies involving muscle regeneration of elderly rats undergoing laser therapy showed an increase in the maturation of satellite cells into myoblasts and myotubes [68].…”