Investigation of DNA damage and inflammatory marker profile in patients after bariatric surgery

Abstract

Purpose: Obesity is a significant risk factor in the development of many serious diseases. The most prominent ones among them are diabetes and coronary heart disease. Elevated blood sugar levels in obese individuals lead to increased susceptibility to infections due to the suppression of the immune response. Moreover, fatty skin folds can cause topical infections, ulcers, and delayed/impaired wound healing. Therefore, inflammatory and pro-inflammatory markers in the serum have gained importance in diseases such as diabetes and obesity. Furthermore, in obesity, reactive oxygen species (ROS) lead to DNA damage. 8-oxo-dG, which is the primary product of DNA oxidation, can be detected in the serum, saliva, and urine, making it an ideal biological marker for DNA damage in large population-based studies. The Comet assay analysis is a method used to demonstrate the double-strand breaks in DNA. Induction of γ-H2AX in tissue indicates the initiation of a well-regulated mechanism to reverse double-strand breaks in DNA. Potential benefits of monitoring the genomic health in obesity include creating a sense of urgency for personalized intervention measures and evaluating their progress. DNA damage in obesity is believed to be a reversible condition. Chronic inflammation is an etiological factor known to support DNA damage and neoplastic transformations in cells. Cytokines secreted from adipose tissue, especially TNF-alpha, IL-6, and IL-1β, promote the accumulation of various cells, including neutrophils, macrophages, and dendritic cells, and it indicates the initiation of an inflammatory process. In this project, it was aimed to investigate possible changes in inflammation markers and DNA damage in individuals undergoing bariatric surgery, who were beginning to improve endocrine and metabolic syndrome markers. Materials and methods: For this purpose, blood and urine samples were collected from 45 obese patients, who had undergone bariatric surgery and 45 healthy volunteers matched for age and gender. The levels of inflammatory markers (IL-1β, IL-6, IL-8, and TNF-α) and the DNA damage marker γ-H2AX in serum, as well as the amount of 8-oxo-dG in urine, were determined using ELISA. Additionally, the percentage of DNA damage was determined using the Comet assay analysis. Results: Weight control achieved through bariatric surgery and the subsequent reduction in fat tissue resulted in a significant decrease in the levels of γ-H2AX and 8-oxo-dG, as well as a parallel significant reduction in the percentage of DNA damage in the Comet assay results. The significant decrease in inflammatory markers IL-1β, IL-6, IL-8, and TNF-α levels indicated that bariatric surgery also affects inflammation indirectly. Conclusion: Although there are numerous studies in the literature on individual parameters related to DNA damage in various diseases and obesity, it is believed that the present study determining DNA damage, oxidation, and repair mechanisms simultaneously with inflammatory marker levels serves as a guiding example for comparing genomic health and stability in pre-obese, post-obese, and non-obese individuals.