DNA damage and nuclear anomalies in peripheral blood lymphocytes from asthma patients and obese individuals

Abstract

Asthma is a chronic, non-communicable respiratory disorder affecting approximately 262 million people worldwide, with India projected to become one of the leading countries in prevalence. Asthma is well-established as a condition of chronic inflammation of the airways and related to systemic oxidative stress, but relatively not much is known about the genomic instability associated with asthma. On the other hand, obesity is found in 650 million people worldwide and 113 million people in India. Studies reported links between asthma and obesity, which include adipose tissue dysfunction and inefficient blood monocyte efferocytosis. Obesity enhances reactive oxygen species (ROS) production and inflammation, leading to DNA lesions. Thus, the aim of this study was to assess the DNA damage and frequencies of micronuclei (MNi), nucleoplasmic bridges (NPB), and nuclear buds (NBUD) in the lymphocytes of asthma patients and obese individuals. This study evaluates the DNA damage and nuclear anomalies in (n = 435) subjects (asthma patients n = 100, asthmatic obese patients n = 131, obese n = 100 and controls n = 104). An alkaline comet assay was used to assess DNA damage and nuclear anomalies were assessed by cytokinesis block micronucleus cytome (CBMN-Cyt) assay. All subjects were recruited between the age of 20 and 60 years. The total DNA damage, MNi, and frequency of total nuclear anomalies were found to be significantly higher in asthma male and female patients, asthmatic obese male and female patients, and obese males and females in comparison to control males and females (p < 0.05). The total comet score showed a positive correlation with the frequency of total nuclear anomalies in asthma male and female patients and obese males, respectively. Overall the findings demonstrate that inflammation and oxidative stress in asthma and obesity lead to DNA damage and genomic instability.