PROBING THE IMPACT OF GAMMA-IRRADIATION ON THE METABOLIC STATE OF NEURAL STEM AND PRECURSOR CELLS USING DUAL-WAVELENGTH INTRINSIC SIGNAL TWO-PHOTON EXCITED FLUORESCENCE  

作　　者：TATIANA B.KRASIEVA ERICH GIEDZINSKI KATHERINE TRAN MARY LAN CHARLES L.LIMOLI BRUCE J.TROMBERG 

机构地区：[1]Laser Microbeam and Medical Program Beckman Laser Institute,University of California Irvine,1002 Health Sciences Road East,Irvine,CA 92612,USA [2]Department of Radiation Oncology University of California,Irvine,California 92697,USA

出　　处：《Journal of Innovative Optical Health Sciences》2011年第3期289-300,共12页创新光学健康科学杂志（英文）

基　　金：supported by U.S.Department of Energy,Grant No.DE-FG02-09ER64798(CLL);National Aeronautics and Space Administration Grant No.NNX09AK25G(CLL);American Cancer Society Grant No.RSG-00-036-04-CNE(CLL);National Institute of Health NIH LAMMP P41 Grant No.R01192(BJT,TBK);National Cancer Institute 2P30CA62203(BJT,TBK).

摘　　要：Two-photon excitedfluorescence(TPEF)spectroscopy and imaging were used to investigate the effects of gamma-irradiation on neural stem and precursor cells(NSPCs).While the observed signal from reduced nicotinamide adenine dinucleotide(NADH)was localized to the mitochondria,the signal typically associated with oxidizedflavoproteins(Fp)was distributed diffusely throughout the cell.The measured TPEF emission and excitation spectra were similar to the established spectra of NAD(P)H and Fp.Fpfluorescence intensity was markedly increased by addition of the electron transport chain(ETC)modulator menadione to the medium,along with a concomitant decrease in the NAD(P)H signal.Three-dimensional(3D)neurospheres were imaged to obtain the cellular metabolic index(CMI),calculated as the ratio of Fp to NAD(P)Hfluorescence intensity.Radiation effects were found to differ between low-dose(
50 cGy)and high-dose(50 cGy)exposures.Low-dose irradiation caused a marked drop in CMI values accompanied by increased cellular proliferation.At higher doses,both NAD(P)H and Fp signals increased,leading to an overall elevation in CMI values.Thesefindings underscore the complex relationship between radiation dose,metabolic state,and proliferation status in NSPCs and highlight the ability of TPEF spectroscopy and imaging to characterize metabolism in 3D spheroids.

关 键 词：Multiphoton microscopy cellular metabolic index gamma radiation brain tumors NAD(P)H FLAVOPROTEINS 

分 类 号：R73[医药卫生—肿瘤]