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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 1:28 |
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Conference: Bucharest University Faculty of Physics 2012 Meeting
Section: Biophysics; Medical Physics
Title:
Cytoprotective effects of high intensity green light
Authors:
F. HALITZCHI (1), Bianca GALATEANU (2), B.AMUZESCU (1), E. RADU (3), S. COMOROSAN (4)
Affiliation:
(1)Dept. Biophysics, Faculty of Biology, University of Bucharest
(2)Dept. Biochemistry, Faculty of Biology, University of Bucharest
(3) MOLIMAGEX Molecular Biology Laboratory, SUUB
(4) Romanian Academy
E-mail
fhalitzchi@yahoo.com
Keywords:
high-density green light, cytoprotection, oxidative stress, cell viability, flow cytometry, qPCR
Abstract:
The aim of the present study was to test the protective effect of “high density” polarized green light on HEK293 cells within a model of exogenous oxidative stress induced by hydrogen peroxide, as well as the changes induced by green light exposure on expression levels of 3 genes (GAPDH, KCND2, KCNH2) via qPCR with absolute quantitation. HEK293 cells were cultured upon confluence in small Petri dishes in a humidified incubator at 37oC, 5% CO2, in DMEM supplemented with 10% FCS and 1% penicillin-streptomycin. Cultured cells were preexposed to green light for 1 hour, then H2O2 at a final concentration of 1 mM, 10 mM or 100 mM was added directly to the culture medium, and the exposure to green light continued for another hour. Subsequently, a propidium iodide cell viability assay was performed by adding the dye to each purified cell sample at a concentration of 1 ug/ml, at cold, and measuring the fluorescence of 15000 cells/sample (Beckman Coulter FC500 flow-cytometer on FL3 channel). In the qPCR assay, total RNA was extracted from cultures exposed to green light for 24 h, 2 h, or unexposed controls; the quantity, purity and integrity of RNA extracts was checked. Purity was inferred from A260/A280 and A260/A230 ratios, while integrity was expressed as RIN (Agilent BioAnalyzer2100). A dilution curve extended on 7 orders of magnitude was achieved for GAPDH. The cell viability of samples treated with green light prior to and during exposure to 10 mM H2O2 was higher than for unexposed controls with 5.87 ± 2.60 % (average ± SEM, n = 9, p = 0.053 – paired Student test). GAPDH expression levels were 105-106 copies/10 ng cDNA, those of KCND2 were 102-103 copies/10 ng, while KCNH2 was absent. These preliminary data point to a new cytoprotective effect of green light to oxidative stress.
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