Effects Of 1.8 GHz Microwaves Radiation On Protein Expression In Human Lens Epithelial Cells

BackgroundThe widespread use of mobile telecommunications has aroused public concern with potential health risks associated with exposure to microwave eletromagnetic fields from these novel products of mobile phones. Aging is one of the most common causes for cataract, but many other factors are involved. Microwave eletromagnetism radiation has been regard as one of the much more important risk factors. Also there is concern about microwave radiation-induced proteomic changes. The shotgun method, as the representative of emerging proteomic technologies, has been widely used in life science research, which can be expected to show the changes in protein expression profile. The potential molecular targets obtained by proteomic analysis might be applied in further investigations to ascertain the possible alteration of protein expression levels which are related to the biological effects induced by microwave radiation and to understanding the possible pathogenic mechanism of cataract.ObjectiveTo investigate the impact of 1.8GHz microwave radiation on the protein expression of human lens epithelial cells (hLECs) in vitro.MethodsThe hLECs were exposed and sham-exposed to 1.8GHz microwave radiation for 2 hours. The specific absorption rate (SAR) was 4 W/kg. After exposure, the proteome extracted from LECs were loaded on the Ettan MDLC system connected to the LTQ-Orbitrap MS. Chemometrics method was used to analyze the differences of MS/MS between exposed- and sham exposed-groups, and to screen the candidate microwave-induced biomarker proteins.QRT-PCR was used to screen the candidate biomarkers on mRNA level in hLECs exposed to 1.8GHz microwaves (SAR,4 W/kg) for 2 hours.After the hLECs were exposed to 1.8GHz microwaves (SAR,4,3 and 2 W/kg) for 2 hours, the western blot assay was utilized to detect the expression of microwave-induced biomarker proteins.Each experiment was repeated at least three times.ResultsThe results of shotgun proteomic analysis indicated that there were 8 proteins with the differential expression between exposure group and sham-exposure group. The results of qRT-PCR showed that there were the expressional differences of 3 genes (VCP, USP35 and SRP68) between exposure group and sham-exposure group. The results of western blot assay exhibited that the expressional levels of two proteins (VCP and USP35) significantly increased and the expressional level of protein SRP68 significantly decreased in hLECs exposed to 1.8GHz (SAR,4 and 3 W/kg) microwave radiation for 2 hours, as compared with sham groups (P<0.05), but there were no significant expressional differences of VCP, USP35 and SRP68 proteins between the exposure group and sham-exposure group when SAR was 2 W/kg (P>0.05).ConclusionThe shotgun method can be applied to screen the differentially expressed proteins in hLECs exposed to 1.8GHz microwaves, and 3 protein biomarkers associated with microwaves radiation were validated by western blot assay. VCP and USP35 proteins might involve in the protein quality control reaction of hLECs exposed to microwave. The alteration of SRP68 protein indicated that microwave may affect the protein secretion.