{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,26]],"date-time":"2026-05-26T06:03:09Z","timestamp":1779775389167,"version":"3.53.1"},"reference-count":33,"publisher":"Springer Science and Business Media LLC","license":[{"start":{"date-parts":[[2026,5,26]],"date-time":"2026-05-26T00:00:00Z","timestamp":1779753600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2026,5,26]],"date-time":"2026-05-26T00:00:00Z","timestamp":1779753600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"name":"Universit\u00e0 degli Studi di Roma La Sapienza"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Graefes Arch Clin Exp Ophthalmol"],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Purpose<\/jats:title>\n                    <jats:p>Pterygium is a common ocular surface disorder strongly associated with ultraviolet (UV) radiation exposure and oxidative stress. Double-strand breaks (DSBs) are among the most deleterious forms of DNA damage, and their repair mainly relies on the non-homologous end joining (NHEJ) pathway, in which the DNA-dependent protein kinase (DNA-PK) complex plays a central role. This study investigated the expression of the DNA-PK complex components\u2014DNA-PKcs, Ku70, and Ku86\u2014in pterygium compared with healthy conjunctiva.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Conjunctival tissues were obtained from six patients undergoing surgical excision of recurrent pterygium and 6 age- and sex-matched controls undergoing ocular surgery without surface disease. Protein and transcript expression of DNA-PKcs, Ku70, and Ku86 were assessed by immunofluorescence, Western blotting, and real-time PCR.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Immunofluorescence revealed markedly reduced DNA-PKcs immunoreactivity in the epithelium of pterygium conjunctiva compared with marked staining in controls. Western blot analysis demonstrated a significant decrease of DNA-PKcs protein, paralleled by a\u2009~\u200913-fold reduction of its mRNA. Similarly, Ku70 and Ku86 protein levels were dramatically reduced (by ~\u200993.5% and ~\u200992.0%, respectively) in pterygium compared with controls.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>This study provides the first evidence of profound down-regulation of the DNA-PK complex in pterygium. The loss of DNA-PKcs and its regulatory subunits Ku70 and Ku86 suggests impaired DSB repair capacity, potentially driven by chronic UV-induced oxidative stress. These alterations may contribute to pterygium pathogenesis and recurrence, highlighting DNA-PK complex proteins as potential biomarkers of disease susceptibility and progression.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1007\/s00417-026-07283-4","type":"journal-article","created":{"date-parts":[[2026,5,26]],"date-time":"2026-05-26T05:13:18Z","timestamp":1779772398000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Loss of DNA-PK complex in recurrent pterygium suggests a role for defective double-strand break repair"],"prefix":"10.1007","author":[{"given":"Leonardo","family":"Lupacchini","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marco","family":"Marenco","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marco","family":"Rosina","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fabiana","family":"Mallone","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cristiana","family":"Mollinari","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Angelina","family":"Pernazza","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alessandro","family":"Lambiase","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daniela","family":"Merlo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2026,5,26]]},"reference":[{"key":"7283_CR1","doi-asserted-by":"publisher","first-page":"1047","DOI":"10.1038\/S41433-020-0786-3","volume":"34","author":"WK Chu","year":"2020","unstructured":"Chu WK, Choi HL, Bhat AK, Jhanji V (2020) Pterygium: new insights. 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The study was approved by the local Ethics Committee (Prot. N. 7465\/2024) and was conducted in accordance with the Tenets of the Declaration of Helsinki.and ethics approval.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent to participate"}},{"value":"Not applicable.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"Clinical trial number"}}]}}