Unraveling the Epigenetic Impact of High-Fat Diet: Dnmt3b and Dnmt3l Expressions in Mouse Ovary

Objective: Obesity is characterized by an increase in adipose tissue volume. It has emerged as a risk factor for infertility. Recent research has unveiled a strong correlation between obesity and epigenetics. Epigenetic mechanisms, primarily DNA methylation which is governed by DNA methyltransferases (Dnmts), regulates gene expression. In the present study, we aimed to evaluate Dnmt3b and Dnmt3l expression in ovary of HFD-induced group compared to control. Materials and Methods: For this purpose, C57BL6/J female mice (4 weeks old) (n=8) were fed either a normal diet consisting of 20% protein, 10% fat and 70% carbohydrate or an HFD consisting of 20% protein, 60% fat and 20% carbohydrate for 12 weeks. At the end of 12 weeks, animals were euthanized, and ovaries were transferred into buffered solution. In accordance with our research objective, we conducted immunohistochemistry to examine the presence of Dnmt3b and Dnmt3l proteins and their changes in the ovaries of HFD-induced mice. Results: Our findings revealed significant alterations in the protein levels in the ovary of the HFD-induced obese mice. Specifically, the total expressions of both Dnmt3b and Dnmt3l were remarkably increased in the ovary of the HFD group (p<0.05). Furthermore, we observed increased expression of Dnmt3b in each stage of folliculogenesis, while Dnmt3b and Dnmt3l expressions were elevated in granulosa cells of the HFD-induced group (p<0.05). Conclusion: These results indicate that HFD has a significant impact on the expression of Dnmt3b and Dnmt3l proteins in the ovaries, particularly affecting granulosa cells, which could be potentially associated with the observed changes in global DNA methylation levels.