Abstract
Purpose :
Telomerase is a ribonucleoprotein complex that maintains chromosome length by adding telomeric repeats. It is a cancer biomarker and has been detected in healthy and diseased body fluids such as saliva, urine, serum. In this study, 1) the level of telomerase protein, and 2) telomerase activity, was assessed in healthy, non-contact lens wearing participants.
Methods :
Study 1: Flush tears were collected bilaterally from 10 participants (mean age 21 ± SD 1 years) at two timepoints (> 24 hours apart). The unprocessed tear samples were tested for telomerase protein levels using enzyme-linked immunosorbent assay (Elabscience telomerase kit).
Study 2: Flush tears were collected bilaterally from 25 adults (mean age 26.8 ± SD 1.4 years). Telomerase activity was tested on unprocessed tears, diluted tears, tears processed with lysis buffer (diluted and undiluted), centrifuged tears (pellet and supernatant) and RNA extracted from tears. Telomerase detection kit with specific Amplifluor primers, telomeric repeat amplification protocol (TRAP) and reverse transcriptase-polymerase chain reaction (RT-qPCR) were used to detect telomerase activity.
Results :
Study 1: The mean telomerase protein level in tears was 163 ± 138.4 ng/mL (Range 39.6 - 661.6 ng/mL). There was no significant difference between right and left eyes at either visit (p=0.49).
Study 2: All tear samples showed either, no amplification, or amplified at late cycles below the limit of quantification, which, using telomerase standards was established to be a minimum of 2408 telomerase copies.
Conclusions :
While telomerase protein can commonly be detected in tear samples from healthy normals, telomerase activity appears to be absent, or below the level of detection (2408 copies) in such circumstances. Further studies are needed to establish how telomerase behaves in tears from those with ocular surface disease.
This is a 2020 ARVO Annual Meeting abstract.