Effect of Laser Wavelength and MSC on Mitochondrial Activation and Apoptosis in Renal Fibrosis

Kidney disease, including both acute and chronic, is the 8th leading cause of death in the United States with over 50,000 deaths in 2010. Progression to chronic kidney disease is marked by fibrosis of both the tubular epithelium as well as the glomeruli with overexpression of extracellular matrix (ECM) proteins such as collagen creating an inhospitable environment for healthy cellular activity. Low level laser therapy (LLLT) is currently being used to promote regenerative effects in wound healing with improved tissue repair and inhibition of tissue degeneration. The purpose of this study was to define the relative contribution of 635 nm, 532 nm, and 405 nm wavelength lasers in a single dose application to early regenerative activity in a mouse unilateral ureter obstruction (UUO) model of renal fibrosis. Treatment including both lasers and mesenchymal stem cells (MSCs) was also investigated to determine the possible effects of laser/MSC synergy. Results demonstrated increased mitochondrial activity with 635 nm laser treatment, increased glomerular cell proliferation with 635 nm laser +/- MSC and 532 nm laser + MSC treatments, and an increase in the anti-inflammatory cytokine IL-10 with 635 nm laser treatment. Pro-fibrotic cytokine TGFβ1 was significantly decreased with the 532 nm laser + MSC treatment, and apoptosis in the fibrotic tissue was decreased by all laser treatments. These results indicate a positive contribution of the 635 nm laser and the 532 nm laser + MSC treatment to early regenerative activity within the fibrotic kidney.