Effects of low intensity ultrasound (LIUS) on the macular degeneration model in vitro

Abstract

AbstractPurpose The retinal pigment epithelium (RPE) is compose of monolayer of tightly connected pigmented cells and supports the function of the normal vision function. Structural deformation and/or inflammation in RPE are commonly accompanied with and in many cases severely aggravate macular degeneration. We have reported previously low‐intensity ultrasound (LIUS) of less than 1 mW/cm^2 shows cyto‐protective and anti‐inflammatory effects on chondrocytes and cartilage tissue under pathologic environments. The aim of this study is to investigate the effects of LIUS on RPE cells in macular degeneration models in vitro.Methods ARPE‐19 cells were grown on a plastic dish or permeable transwell inserts and were treated with various damaging agents such as PlGF (an agonist of VEGF receptor), NaCN and H2O2. Then, cells were untreated or treated with varying intensities of LIUS with a maximum of 200 mW/cm^2 once for 20 min a day. Viability of cells was examined with Wst‐1 and TUNEL assays. Permeability of the cell monolayer on transwell membrane was tested by trans‐epithelial electrical resistance (TEER) system. JC‐1 staining was also performed to measure mitochondrial activity in cells.Results Cell damaging agents increased cell death and permeability of cell monolayer in a dose‐dependent dose manner. LIUS treatment significantly reduced both of the cell death and permeability. Changes in the mitochondrial membrane potential were also decreased by LIUS.Conclusion This study demonstrated that LIUS inhibits cell death of ARPE‐19 by various pathologic stresses, thereby might be a promising treatment for RPE under macular degeneration.