Jih-Shyong Lin1,2, Chia-Jung Wang2, Wen-Tyng Li2,3. 1. Division of Cardiology, Department of Internal Medicine, Taoyuan General Hospital, Ministry of Health and Welfare. 2. Department of Biomedical Engineering. 3. Center for Biomedical Technology and Center for Nanotechnology, Chung Yuan Christian University, Taoyuan, Taiwan.
Abstract
BACKGROUND: Vascular smooth muscle cells play a critical role in the intimal hyperplasia of restenosis. A previous study of a rat balloon injury model demonstrated that photodynamic therapy (PDT) using indocyanine green (ICG) and near-infrared (NIR) light irradiation reduced intimal hyperplasia in carotid arteries. However, the effect of ICG-PDT on smooth muscle cells remains unclear. This study aimed to evaluate the effects of PDT with ICG and NIR irradiation on the viability of vascular smooth muscle (A-10) cells. METHODS: A-10 cells were incubated with ICG at different concentrations for different time intervals. Intracellular accumulation of ICG inside the cells was observed by light microscopy, ultraviolet-visible (UV-VIS) spectrophotometry and spectrofluorometry. Cell viability and cell death after ICG-PDT were assessed by 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide assay and lactate dehydrogenase release assay. Changes in nuclear morphology and cell cycle distribution were evaluated to determine the possible cell death mechanism mediated by ICG-PDT. RESULTS: ICG uptake in A-10 cells increased with the amount of ICG in the culture media. The intracellular accumulation of ICG reached a maximum at 8 h. After ICG-PDT, cell viability decreased and cell death increased in a concentration- dependent manner. The half maximal inhibitory concentration of ICG was 8.3 μM with 4 J/cm2 NIR irradiation. Membrane blebbing and chromatin condensation were observed, and the percentage of cells in the sub-G1 phase increased after ICG-PDT. Thus, apoptosis might be responsible for decreasing the viability of A-10 cells by ICG-PDT. CONCLUSIONS: This study demonstrated that ICG-PDT had an inhibitory effect on smooth muscle cells, possibly via an apoptosis pathway.
BACKGROUND: Vascular smooth muscle cells play a critical role in the intimal hyperplasia of restenosis. A previous study of a rat balloon injury model demonstrated that photodynamic therapy (PDT) using indocyanine green (ICG) and near-infrared (NIR) light irradiation reduced intimal hyperplasia in carotid arteries. However, the effect of ICG-PDT on smooth muscle cells remains unclear. This study aimed to evaluate the effects of PDT with ICG and NIR irradiation on the viability of vascular smooth muscle (A-10) cells. METHODS: A-10 cells were incubated with ICG at different concentrations for different time intervals. Intracellular accumulation of ICG inside the cells was observed by light microscopy, ultraviolet-visible (UV-VIS) spectrophotometry and spectrofluorometry. Cell viability and cell death after ICG-PDT were assessed by 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide assay and lactate dehydrogenase release assay. Changes in nuclear morphology and cell cycle distribution were evaluated to determine the possible cell death mechanism mediated by ICG-PDT. RESULTS: ICG uptake in A-10 cells increased with the amount of ICG in the culture media. The intracellular accumulation of ICG reached a maximum at 8 h. After ICG-PDT, cell viability decreased and cell death increased in a concentration- dependent manner. The half maximal inhibitory concentration of ICG was 8.3 μM with 4 J/cm2 NIR irradiation. Membrane blebbing and chromatin condensation were observed, and the percentage of cells in the sub-G1 phase increased after ICG-PDT. Thus, apoptosis might be responsible for decreasing the viability of A-10 cells by ICG-PDT. CONCLUSIONS: This study demonstrated that ICG-PDT had an inhibitory effect on smooth muscle cells, possibly via an apoptosis pathway.
Authors: Peter R Waterman; Marcus Overhaus; Joerg Heckenkamp; Giuseppe R Nigri; Patrick F C Fungaloi; Michael E Landis; Sylvie C Kossodo; Glenn M LaMuraglia Journal: Photochem Photobiol Date: 2002-01 Impact factor: 3.421
Authors: Dean J Kereiakes; Arthur M Szyniszewski; Dennis Wahr; Howard C Herrmann; Daniel I Simon; Campbell Rogers; Paul Kramer; Wendy Shear; Alan C Yeung; Kendrick A Shunk; Tony M Chou; Jeffrey Popma; Peter Fitzgerald; Tanya E Carroll; David Forer; Daniel C Adelman Journal: Circulation Date: 2003-08-25 Impact factor: 29.690