| Background: Long non-coding RNA(lnc RNA)is a kind of non-coding RNA which is longer than 200 nt in length,widely involved in and regulates various metabolic processes in cells,and can play a regulatory role when cells are stimulated by xenobiotic compounds and toxins.Organophosphate esters(OPEs)are a type of compounds that are commonly used in daily life and have caused large-scale pollution worldwide,posing potential hazards to the environment and human body However,the relationship between organic phosphate stimulation and lnc RNA regulation is unclear.Objects: Our team previously found that lnc RNA CYTOR expression was downregulated in human kidney cells stimulated by OPE.In order to analyze this abnormal phenomenon,our study investigated the toxic effects of organophosphate esters TCPP and TNPP on two human renal cell lines HEK293 T and HK-2,and the mechanism by which OPEs affect CYTOR expression,providing a reference for the study of the toxicological mechanism of organophosphate esters.Results: Within a certain concentration range,TCPP and TNPP had an inhibitory effect on HEK293 T and HK-2 cells,while promoting cell apoptosis and increasing cellular reactive oxygen species.The activities of the ACh E and CES in cells were not inhibited,indicating that the main pathways of TCPP and TNPP causing toxic effects on cells are cell apoptosis and reactive oxygen species rather than esterase inhibition.Under two OPEs treatment,CYTOR in cells was down regulated,which was consistent with the previous transcriptome sequencing results.Overexpression of CYTOR to a certain extent decreased the apoptosis rate under the stimulation of two OPEs,indicating that CYTOR plays a regulatory role in OPEs stimulation.The potential transcription factor CEBPA that might bind to the CYTOR promoter region was predicted and screened by bioinformatic technology.Western blot experiments indicated that protein levels of CEBPA showed the same change trend as CYTOR m RNA expression.And The results of Dual Luciferase Reporter Assay further proved that CEBPA is a promoting transcription factor of CYTOR.In addition,detection of the protein levels of the key factors in MAPK signaling pathway found that after treatment with TCPP and TNPP,the upstream regulatory molecule of CEBPA,ERK,had not changed in protein levels,while the level of its activated form p-ERK had decreased.The cellular receptor GPER,one of the upstream regulatory molecules of ERK,also underwent a decrease in protein levels under the treatment of the two OPEs.Conclusion: TCPP and TNPP might act as extracellular signals to inhibit GPER activity,reduce ERK activation,and lower the level of CEBPA,resulting in a decrease in CYTOR expression.And this promoted cell ROS and apoptosis.Therefore,GPER/ERK/CEBPA might be a pathway for OPEs to exert cellular toxicity leading to renal cell damage.Our discovery can provide theoretical reference for relevant research on the toxic mechanism of OPEs and lnc RNA regulation. |
