Associations between TERF2 rs251796 and leukocyte telomere length in males with optic neuritis

Abstract

Background. Optic neuritis (ON) is the most common cause of subacute optic neuropathy in young adults [1]. It is thought to be an immune-mediated disease and research indicates a link between telomeres and inflammation, as studies demonstrate that inflammation can lead to increased telomere shortening [2]. Telomere-related genes and telomere dysfunction in diseases can lead to persistent chronic low-grade inflammation [3]. Telomeric repeat binding factor 2 (TERF2) functions as an inhibitor of telomerase and thus plays a role in the regulation of telomere length [4]. Aim. The present study aimed to determine the associations of telomere-related TERF2 rs251796 polymorphism and relative leukocyte telomere length (LTL) with the occurrence of ON in male subjects. Methods. Men diagnosed with optic neuritis (ON) were analyzed, while the control group comprised men without any health problems. The DNA samples were obtained from peripheral blood leukocytes and purified using the DNA salting-out technique. Real-time polymerase chain reaction (RT-PCR) assessed single nucleotide polymorphism (SNP) and relative leukocyte telomere lengths (LTL). The data obtained were processed and analyzed using the "IBM SPSS Statistics 29.0" program. Results. TERF2 rs251796 (AA, AG, and TT) statistically significantly differed between the long and short telomeres group, with frequencies of 65.7%, 22.9%, and 2.0% in long telomeres, compared to 35.1%, 56.8%, and 8.1% in the short telomeres group (p=0.013). TERF2 rs251796 CT genotype, compared to CC, under the codominant genetic model, was associated with a 4.7-fold decreased odds of telomere shortening (p=0.005). Meanwhile, CT+TT genotypes, compared to CC under the dominant genetic model, were associated with a 3.5- fold decreased odds of telomere shortening (p=0.011). Also, CT genotype, compared to CC+TT, under the overdominant genetic model, is associated with a 4.4-fold decreased odds of telomere shortening (p=0.004). Conclusions. The current findings suggest a protective role of TERF2 rs251796 in the occurrence of ON in men.