Ultraviolet light triggers the conversion of Cu2+-bound Aβ42 aggregates into cytotoxic species in a copper chelation-independent manner.
Increasing evidence indicates that abnormal Cu2+ binding to Aβ peptides are responsible for the formation of soluble Aβ oligomers and ROS that play essential roles in AD pathogenesis. During studying the Cu2+-chelating treatment of Cu2+-bound Aβ42 aggregates, we found that UV light exposure pronouncedly enhances cytotoxicity of the chelator-treated and -untreated Cu2+-bound Aβ42 aggregates. This stimulated us to thoroughly investigate (1) either the chelation treatment or UV light exposure leads to the increased cytotoxicity of the aggregates, and (2) why the chelator-treated and -untreated Cu2+-bound Aβ42 aggregates exhibit the increased cytotoxicity following UV light exposure if the latter is the case. The data indicated that the controlled UV exposure induced the dissociation of Cu2+-free and -bound Aβ42 aggregates into SDS-stable soluble oligomers and the production of ROS including H2O2 in an UV light intensity- and time-dependent, but Cu2+ chelation-independent manner. Although we can't fully understand the meaning of this finding at the current stage, the fact that the UV illuminated Aβ42 aggregates can efficiently kill HeLa cells implies that the aggregates after UV light exposure could be used to decrease the viability of skin cancer cells through skin administration.
Key Laboratory of Pesticide &Chemical Biology, Ministry of Education, and School of Chemistry, Central China Normal University, Wuhan 430079, Hubei.
Xiongwei
X
Dong
Key Laboratory of Pesticide &Chemical Biology, Ministry of Education, and School of Chemistry, Central China Normal University, Wuhan 430079, Hubei.
Zhe
Z
Zhang
Key Laboratory of Pesticide &Chemical Biology, Ministry of Education, and School of Chemistry, Central China Normal University, Wuhan 430079, Hubei.
Dan
D
Zhao
Key Laboratory of Pesticide &Chemical Biology, Ministry of Education, and School of Chemistry, Central China Normal University, Wuhan 430079, Hubei.
Yaojing
Y
Liu
Key Laboratory of Pesticide &Chemical Biology, Ministry of Education, and School of Chemistry, Central China Normal University, Wuhan 430079, Hubei.
Yan
Y
Meng
School of Chemical and Materials Engineering, Hubei Polytechnic University, Huangshi, 435003 Hubei, China.
Yong
Y
Zhang
Key Laboratory of Pesticide &Chemical Biology, Ministry of Education, and School of Chemistry, Central China Normal University, Wuhan 430079, Hubei.
Dan
D
Zhang
Key Laboratory of Pesticide &Chemical Biology, Ministry of Education, and School of Chemistry, Central China Normal University, Wuhan 430079, Hubei.
Changlin
C
Liu
D016229:Amyloid beta-Peptides / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D045744:Cell Line, Tumor; D002614:Chelating Agents / Q000494:pharmacology*; D005617:Chlorofluorocarbons, Methane / Q000737:chemistry / Q000494:pharmacology; D003300:Copper / Q000378:metabolism*; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D066329:Protein Aggregates / Q000187:drug effects* / Q000528:radiation effects*; D066263:Protein Aggregation, Pathological; D017433:Protein Structure, Secondary; D017382:Reactive Oxygen Species; D014466:Ultraviolet Rays / Q000009:adverse effects
D016229:Amyloid beta-Peptides; D002614:Chelating Agents; D005617:Chlorofluorocarbons, Methane; D066329:Protein Aggregates; D017382:Reactive Oxygen Species; D003300:Copper; C005848:trichlorofluoromethane; D006861:Hydrogen Peroxide