Comparison of telomere length and association with progenitor cell markers in lacrimal gland between Sj?gren syndrome and non-Sj?gren syndrome dry eye patients

摘要

Purpose: Indicators of aging such as disruption of telomeric function due to shortening may be more frequent in dysfunctional lacrimal gland. The aims of this study were to 1) determine the viability of quantitative fluorescence in situ hybridization of telomeres (telo-FISH) for the assessment of telomere length in lacrimal gland in Sj?gren and non- Sj?gren syndrome patients; and 2) investigate the relationship between progenitor cell markers and telomere length in both groups. Methods: Quantitative fluorescence in situ hybridization with a peptide nucleic acid probe complementary to the telomere repeat sequence was performed on frozen sections from human lacrimal gland tissues. The mean fluorescence intensity of telomere spots was automatically quantified by image analysis as relative telomere length in lacrimal gland epithelial cells. Immunostaining for p63, nucleostemin, ATP-binding cassette, sub-family G, member 2 (ABCG2), and nestin was also performed. Results: Telomere intensity in the Sj?gren syndrome group (6,785.0±455) was significantly lower than that in the non-Sj?gren syndrome group (7,494.7±477; p=0.02). Among the samples from the non-Sj?gren syndrome group, immunostaining revealed that p63 was expressed in 1–3 acinar cells in each acinar unit and continuously in the basal layer of duct cells. In contrast, in the Sj?gren syndrome group, p63 and nucleostemin showed a lower level of expression. ABCG2 was expressed in acinar cells in both sjogren and non-Sjogren syndrome. Conclusions: The results of this study indicate that 1) telo-FISH is a viable method of assessing telomere length in lacrimal gland, and 2) telomere length in Sj?gren syndrome is shorter and associated with lower levels of expression of p63 and nucleostemin than in non-Sj?gren syndrome.