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Author van der Burght, B.W.; Hansen, M.; Olsen, J.; Zhou, J.; Wu, Y.; Nissen, M.H.; Sparrow, J.R. url  doi
openurl 
  Title Early changes in gene expression induced by blue light irradiation of A2E-laden retinal pigment epithelial cells Type Journal Article
  Year 2013 Publication (up) Acta Ophthalmologica Abbreviated Journal Acta Ophthalmol  
  Volume 91 Issue 7 Pages e537-45  
  Keywords Apoptosis; Cell Line; Cell Survival; Gene Expression Regulation/*physiology; Humans; Light; Lipofuscin/genetics; Oligonucleotide Array Sequence Analysis; Principal Component Analysis; Pyridinium Compounds; RNA, Messenger/genetics; Real-Time Polymerase Chain Reaction; Retinal Pigment Epithelium/metabolism/pathology/*radiation effects; Retinoids/*genetics; Transcriptome; A2e; age-related macular degeneration; apoptosis; complement cascade; gene expression; retinal pigment epithelial cells; blue light; retinal pigment epithelial; epigenetics  
  Abstract PURPOSE: Accumulation of bisretinoids as lipofuscin in retinal pigment epithelial (RPE) cells is implicated in the pathogenesis of some blinding diseases including age-related macular degeneration (AMD). To identify genes whose expression may change under conditions of bisretinoid accumulation, we investigated the differential gene expression in RPE cells that had accumulated the lipofuscin fluorophore A2E and were exposed to blue light (430 nm). METHODS: A2E-laden RPE cells were exposed to blue light (A2E/430 nm) at various time intervals. Cell death was quantified using Dead Red staining, and RNA levels for the entire genome was determined using DNA microarrays (Affymetrix GeneChip Human Genome 2.0 Plus). Array results for selected genes were confirmed by real-time reverse-transcriptase polymerase chain reaction. RESULTS: Principal component analysis revealed that the A2E-laden RPE cells irradiated with blue light were clearly distinguishable from the control samples. We found differential regulation of genes belonging to the following functional groups: transcription factors, stress response, apoptosis and immune response. Among the last mentioned were downregulation of four genes that coded for proteins that have an inhibitory effect on the complement cascade: (complement factor H, complement factor H-related 1, complement factor I and vitronectin) and of two belonging to the classical pathway (complement component 1, s subcomponent and complement component 1, r subcomponent). CONCLUSION: This study demonstrates that blue light irradiation of A2E-laden RPE cells can alter the transcription of genes belonging to different functional pathways including stress response, apoptosis and the immune response. We suggest that these molecules may be associated to the pathogenesis of AMD and can potentially serve as future therapeutic targets.  
  Address Department of International Health, Immunology and Microbiology, Eye Research Unit, University of Copenhagen, Copenhagen, DenmarkDepartment of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, DenmarkDepartment of Ophthalmology, Columbia University, New York, New York, USA  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1755-375X ISBN Medium  
  Area Expedition Conference  
  Notes PMID:23742627 Approved no  
  Call Number IDA @ john @ Serial 346  
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Author Yue, F.; Xia, K.; Wei, L.; Xing, L.; Wu, S.; Shi, Y.; Man, L.S.; Shui, G.; Xiang, X.; Russell, R.; Zhang, D. url  doi
openurl 
  Title Constant light exposure causes dysregulation of sphingolipids and promotes steatohepatitis in high-fat fed rats Type Journal Article
  Year 2020 Publication (up) Journal of Gastroenterology and Hepatology Abbreviated Journal J Gastroenterol Hepatol  
  Volume in press Issue Pages  
  Keywords Animals; apoptosis; ceramide; light pollution; non-alcoholic fatty liver disease; sphingolipids  
  Abstract BACKGROUND AND AIM: Non-alcoholic fatty liver disease (NAFLD) is a growing public health concern worldwide. With the progression of urbanization, light pollution is becoming an inevitable risk factor for NAFLD. However, the role of light pollution on NAFLD is insufficiently understood, and the underlying mechanism remains unclear. The present study explored effects of constant light exposure on NAFLD and elucidated its related mechanisms. METHODS: Thirty-two male SD rats were divided into 4 groups (n=8 each): 1) rats on a normal diet exposed to standard light-dark cycle (ND-LD); 2) rats on a normal diet exposed to constant light (ND-LL); 3) rats on a high fat diet exposed to standard light-dark cycle (HFD-LD); 4) and rats on a high fat diet exposed to constant light (HFD-LL). After 12 weeks treatment, rats were sacrificed and pathophysiological assessments were performed. Targeted lipidomics was used to measure sphingolipids, including ceramides, glucosylceramides and lactosylceramides, sphingomyelins and sphingosine-1-phosphates in plasma and liver tissues. RESULTS: In normal chow rats, constant light exposure led to glucose abnormalities and dyslipidemia. In high-fat fed rats, constant light exposure exacerbated glucose abnormalities, dyslipidemia, insulin resistance, inflammation and aggravated steatohepatitis. Compared to HFD-LD rats, HFD-LL had decreased plasma sphingosine-1-phosphate and elevated liver concentrations of total ceramides and specific ceramide species (ceramide d18:0/24:0, ceramide d18:1/22:0, ceramide d18:1/24:0 and ceramide d18:1/24:1), and which were associated with increased hepatocyte apoptosis. CONCLUSIONS: Constant light exposure causes dysregulation of sphingolipids and promotes steatohepatitis in high-fat fed rats.  
  Address Department of Endocrinology, Xiangya Hospital, Central South University, Changsha, Hunan, China  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0815-9319 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:32027419 Approved no  
  Call Number GFZ @ kyba @ Serial 2829  
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Author Chamorro, E.; Bonnin-Arias, C.; Perez-Carrasco, M.J.; Munoz de Luna, J.; Vazquez, D.; Sanchez-Ramos, C. url  doi
openurl 
  Title Effects of light-emitting diode radiations on human retinal pigment epithelial cells in vitro Type Journal Article
  Year 2013 Publication (up) Photochemistry and Photobiology Abbreviated Journal Photochem Photobiol  
  Volume 89 Issue 2 Pages 468-473  
  Keywords Human Health; Apoptosis/*radiation effects; Biological Markers/metabolism; Caspases/metabolism; Cell Survival/radiation effects; DNA Damage; Epithelial Cells/cytology/metabolism/*radiation effects; Histones/metabolism; Humans; Light; Membrane Potential, Mitochondrial/*radiation effects; Mitochondria/*radiation effects; Photoperiod; Primary Cell Culture; Reactive Oxygen Species/metabolism; Retinal Pigment Epithelium/cytology/metabolism/*radiation effects  
  Abstract Human visual system is exposed to high levels of natural and artificial lights of different spectra and intensities along lifetime. Light-emitting diodes (LEDs) are the basic lighting components in screens of PCs, phones and TV sets; hence it is so important to know the implications of LED radiations on the human visual system. The aim of this study was to investigate the effect of LEDs radiations on human retinal pigment epithelial cells (HRPEpiC). They were exposed to three light-darkness (12 h/12 h) cycles, using blue-468 nm, green-525 nm, red-616 nm and white light. Cellular viability of HRPEpiC was evaluated by labeling all nuclei with DAPI; Production of reactive oxygen species (ROS) was determined by H2DCFDA staining; mitochondrial membrane potential was quantified by TMRM staining; DNA damage was determined by H2AX histone activation, and apoptosis was evaluated by caspases-3,-7 activation. It is shown that LED radiations decrease 75-99% cellular viability, and increase 66-89% cellular apoptosis. They also increase ROS production and DNA damage. Fluorescence intensity of apoptosis was 3.7% in nonirradiated cells and 88.8%, 86.1%, 83.9% and 65.5% in cells exposed to white, blue, green or red light, respectively. This study indicates three light-darkness (12 h/12 h) cycles of exposure to LED lighting affect in vitro HRPEpiC.  
  Address Neuro-Computing and Neuro-Robotics Research Group, Universidad Complutense de Madrid, Madrid, Spain. eva.chamorro@opt.ucm.es  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0031-8655 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:22989198 Approved no  
  Call Number LoNNe @ christopher.kyba @ Serial 511  
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