The Mechanisms Of Bisphenola-induced DNA Damage In INS-1Cells

Objective: Bisphenol A (BPA) is one of the endocrine disruptor, which is widely usedto manufacture polycarbonate plastic and epoxy resins. With the extensive applicationof plastic products, people have more opportunities to expose to the BPA. Many animalstudies have demonstrated that BPA can play a role in reproductive toxicity and affectthe normal metabolic function. Recent research has showed that BPA can influence thefunction of islet and induce the insulin resistance. In this study, our aim is to access theDNAdamage of BPAand to clarify the mechanisms, using INS-1cells.Method: INS-1cells were exposed to different doses of BPA (25,50,100μM). Weexamined the DNA damage and the expression of protein induced by BPA using singlecell gel electrophoresis (SCGE) assay and western bolt respectively. We examined theintracellular reactive oxygen species (ROS) with2’,7’-dihydro dichlorofluorescein(DCFH) and the GSH with o-phthalaldehyde(OPT) to discuss the possible mechanismsof DNA damage. We detected the role of oxidative stress-associated damage in DNAdamage by N-acetyl cysteine (NAC) intervention experiment. The data was analyzedby using one-way analysis of variance (ANOVA) and Student’s t-test (spss v11.5software).Results: BPA caused a significant increase of the DNA migration compared to the untreated cells. The tail length, tail moment and tail DNA%were also significantlyincreased in INS-1cell. Moreover, the expression of DNA damage protein (p53andp-Chk2(T68)) was also significantly increased. The exposure to various doses of BPAcaused the content of intracellular ROS increased significantly and the level of GSHreduced significantly. NAC as an inhibitor of intracellular ROS, can significantlydecrease the level of DNA strand breaks and the expression of DNA damage protein,and also can significantly reduce the generation of intracellular reactive oxygen.Conclusion: BPA can induce DNA damage in INS-1cells, and the expression of DNAdamage protein (p53and p-Chk2(T68)) was significantly increased. BPA caused thecontent of intracellular ROS increased significantly and make the cells in a state ofoxidative stress. NAC as an inhibitor of intracellular ROS, can reduce the generation ofintracellular reactive oxygen, can decrease the level of DNA strand breaks and theexpression of DNA damage protein. All of these indicate the mechanisms of bisphenolA-induced DNA damage were associated with oxidative stress.