Investigation of biochemical and epigenetic effects of methylparaben exposure on zebrafish embryos

Objective: The aim of our study is to investigate the adverse effects of methylparaben exposure at molecular, biochemical and epigenetic levels.Materials and methods: LC50 dose was determined, locomotor activity test, expression of genes associated with apoptosis and methylation was determined by RT-PCR method. Apoptotic cells were determined by acridine orange staining method and lipid accumulations were determined by oil red o staining. Vitellogenin was detected by in situ hybridization. Biochemical parameters were determined by spectrophotometric methods and changes in H3K27ac histone modification by chromatin immunoprecipitation (ChIP) method. RNA-seq was performed by NGS (next-generation sequencing) method and the BlueBee bioinformatics program was used for analysis. Gene ontology and gene cluster analysis of significantly changed genes were made on the DAVID bioinformatics website. Results: Methylparaben exposure caused pericardial edema, pigmentation and tail defects, decreased movements. Changes in gene expressions associated with apoptosis and methylation, apoptotic cells, lipid accumulation, vitellogenin expression, increased lipid peroxidation nitric oxide levels; decreased glutathione s-transferase activities were observed. Changes in H3K27ac histone modifications were not significant but expressions of 172 genes significantly changed related to translation, lipid metabolism, coagulation, and energy metabolism according to the gene clusters analysis. Conclusion: Methylparaben exposure caused apoptosis, oxidant damage, did not change histone modifications but changed gene expressions related to translation, lipid metabolism, coagulation, and energy metabolism.