{
  "abstract": "Purpose: 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—DNA-PKcs, Ku70, and Ku86—in pterygium compared with healthy conjunctiva.\n\nMethods: 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.\n\nResults: 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 ~ 13-fold reduction of its mRNA. Similarly, Ku70 and Ku86 protein levels were dramatically reduced (by ~ 93.5% and ~ 92.0%, respectively) in pterygium compared with controls.\n\nConclusions: 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.\n\nSupplementary Information: The online version contains supplementary material available at https://doi.org/10.1007/s00417-026-07283-4.",
  "abstract_shown": true,
  "affiliations": [
    "Laboratory of Molecular and Cellular Neurobiology, IRCCS San Raffaele Roma, Via di Val Cannuta 247, Rome, 00166 Italy",
    "Department of Sense Organs, Sapienza - University of Rome, Viale del Policlinico 155, Rome, 00161 Italy",
    "Department of Neuroscience, Italian National Institute of Health (ISS), Viale Regina Elena 299, Rome, 00161 Italy",
    "IRCCS-G.B. Bietti Foundation, Via Livenza 3, Rome, 00198 Italy",
    "Institute of Translational Pharmacology (IFT), National Research Council, Via Fosso del Cavaliere 100, Rome, 00133 Italy",
    "Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Corso della Repubblica 79, Latina, 04100 Italy"
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 8,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Leonardo Lupacchini"
    },
    {
      "affs": [
        1
      ],
      "name": "Marco Marenco"
    },
    {
      "affs": [
        2
      ],
      "name": "Marco Rosina"
    },
    {
      "affs": [
        1,
        3
      ],
      "name": "Fabiana Mallone"
    },
    {
      "affs": [
        2,
        4
      ],
      "name": "Cristiana Mollinari"
    },
    {
      "affs": [
        5
      ],
      "name": "Angelina Pernazza"
    },
    {
      "affs": [
        1
      ],
      "name": "Alessandro Lambiase"
    },
    {
      "affs": [
        2
      ],
      "name": "Daniela Merlo"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/bkrzwp7g0j88s.bib",
  "cited_by": 0,
  "doi": "10.1007/s00417-026-07283-4",
  "fulltext_url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC13736378/",
  "id": "bkrzwp7g0j88s",
  "issns": [
    "0721-832X",
    "1435-702X"
  ],
  "landing_url": "https://doi.org/10.1007/s00417-026-07283-4",
  "language": "en",
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Research"
    ],
    [
      "openalex",
      "1312|DNA Repair Mechanisms"
    ]
  ],
  "openalex": "W7162412857",
  "pdf_url": "https://link.springer.com/content/pdf/10.1007/s00417-026-07283-4.pdf",
  "pmcid": "PMC13736378",
  "pmid": "42189208",
  "published": "2026-05-26",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/bkrzwp7g0j88s.ris",
  "sources": [
    {
      "first_seen": "2026-11-09T12:21:50Z",
      "native_id": "PMC13736378",
      "source": "pmc",
      "url": "https://doi.org/10.1007/s00417-026-07283-4"
    }
  ],
  "subjects": [
    {
      "field": "biochemistry",
      "origin": "openalex:1312|DNA Repair Mechanisms",
      "subfield": "molecular-biology"
    }
  ],
  "title": "Loss of DNA-PK complex in recurrent pterygium suggests a role for defective double-strand break repair",
  "title_text": "Loss of DNA-PK complex in recurrent pterygium suggests a role for defective double-strand break repair",
  "type": "peer-reviewed",
  "updated_at": "2026-11-09T12:21:50Z",
  "url": "https://research.draconitic.com/paper/bkrzwp7g0j88s",
  "venue": "Graefe's Archive for Clinical and Experimental Ophthalmology",
  "versions": []
}