Association of Egr-1 and autophagy-related gene polymorphism in men with chronic obstructive pulmonary disease

Background/Purpose: Autophagy is important in cellular homeostasis and control of inflammatory immune response. Increased autophagy has recently been associated with increased cell death and chronic obstructive pulmonary disease (COPD) pathogenesis. Two autophagy regulator genes have been identified: Egr-1 (early growth response), associated with different phenotype expressions in asthma; and, Atg16L1 (autophagy related 16-like 1), a candidate gene responsible for susceptibility to chronic inflammatory diseases. We will explore the role of the Egr-1 and Atg16L1 gene polymorphisms in COPD. Methods: The genotypes of 151 male smoking patients with COPD and 100 male smoking controls were evaluated by polymerase chain reaction followed by restriction fragment length polymorphism analysis of the Egr-1 (-4071 A → G) rs7729723 and Atg16L-1 (T300A) rs2241880 variants. Results: The G allele of the Egr-1 gene polymorphism was associated with an increased risk of developing COPD [odds ratio (OR), 2.05; 95% confidence interval (CI), 1.15-3.72], and participants with the G allele polymorphism (GG and GA genotypes) had a 2.56-fold higher risk (OR, 2.56; 95% CI, 1.31-5.16) of having COPD than those homozygous for the A allele [35.8% (54/151) vs. 24.0% (24/100); p = 0.007]. Participants with the A allele of the Atg16L1 gene polymorphism (AA and AG genotypes) had a 3.34-fold higher risk (OR, 3.34; 95% CI, 1.32-8.97) of having COPD than those homozygous for the G allele [93.4% (141/151) vs. 81.0% (81/100); p = 0.013]. Conclusion: The Egr-1 and Atg16L1 genes' polymorphisms were significant risk factors for susceptibility to COPD. These results demonstrate that autophagy regulator genetic mutations are associated with COPD in male smokers.