title: Ultraviolet A exposure induces reversible disruption of gap junction intercellular communication in lens epithelial cells.
abstract: Gap junction intercellular communication (GJIC) is essential for the proper function of many organs including the lens. Disruption of GJIC can cause lens metabolic disorder and can induce cataracts. The purpose of this study was to investigate the signal transduction pathways involved in GJIC disruption following ultraviolet A (UVA) exposure in lens epithelial cells. Following exposure of human lens epithelial cells to UVA, connexin 43 (Cx43), the main component of gap junctions, was down-regulated at both the mRNA and protein levels. Furthermore, we observed that UVA exposure can increase protein kinase C activity and stimulate reactive oxygen species generation and lipid peroxidation. Using scrape load dye transfer technique, we found that the GJIC is compromised by UVA exposure. In addition, we demonstrated that UVA-induced modulation of GJIC was associated with p38 mitogen-activated protein kinase activation. More importantly, at non-lethal doses (10 J/cm²), the UVA-induced GJIC disruption and the consequent alterations were reversible. Collectively, our data revealed a new signaling pathway in GJIC disruption following UVA exposure, suggesting that UVA-compromised gap junction activity may sensitize human lens to photoaging and cataract formation.
authors: Department of Ophthalmology, The Fourth Affiliated Hospital of China Medical University, Key Lens Research Laboratory of Liaoning Province, Shenyang 110005, P.R. China.
authors: Dayang
authors: D
authors: Wu
authors: Jiangyue
authors: J
authors: Zhao
authors: Di
authors: D
authors: Wu
authors: Jinsong
authors: J
authors: Zhang
mesh_terms: D002450:Cell Communication / Q000528:radiation effects*; D002460:Cell Line; D018031:Connexin 43 / Q000235:genetics / Q000378:metabolism; D004789:Enzyme Activation / Q000528:radiation effects; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*; D017629:Gap Junctions / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*; D005786:Gene Expression Regulation / Q000528:radiation effects; D006801:Humans; D007908:Lens, Crystalline / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*; D015227:Lipid Peroxidation / Q000528:radiation effects; D011493:Protein Kinase C / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000528:radiation effects; D014466:Ultraviolet Rays; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D018031:Connexin 43; D017382:Reactive Oxygen Species; D011493:Protein Kinase C; D048051:p38 Mitogen-Activated Protein Kinases