{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,27]],"date-time":"2026-04-27T19:21:51Z","timestamp":1777317711936,"version":"3.51.4"},"reference-count":30,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2020,2,7]],"date-time":"2020-02-07T00:00:00Z","timestamp":1581033600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000002","name":"National Institutes of Health","doi-asserted-by":"publisher","award":["RO1EYO6000 and R21EYO29097"],"award-info":[{"award-number":["RO1EYO6000 and R21EYO29097"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]},{"name":"New England Corneal Transplant Fund","award":["none"],"award-info":[{"award-number":["none"]}]},{"DOI":"10.13039\/100007745","name":"Massachusetts Lions Eye Research Fund","doi-asserted-by":"publisher","award":["none"],"award-info":[{"award-number":["none"]}],"id":[{"id":"10.13039\/100007745","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Bioengineering"],"abstract":"<jats:p>The cornea is avascular, which makes it an excellent model to study matrix protein expression and tissue stiffness. The corneal epithelium adheres to the basement zone and the underlying stroma is composed of keratocytes and an extensive matrix of collagen and proteoglycans. Our goal was to examine changes in corneas of 8- and 15-week mice and compare them to 15-week pre-Type 2 diabetic obese mouse. Nanoindentation was performed on corneal epithelium in situ and then the epithelium was abraded, and the procedure repeated on the basement membrane and stroma. Confocal imaging was performed to examine the localization of proteins. Stiffness was found to be age and obesity dependent. Young\u2019s modulus was greater in the epithelium from 15-week mice compared to 8-week mice. At 15 weeks, the epithelium of the control was significantly greater than that of the obese mice. There was a difference in the localization of Crb3 and PKC\u03b6 in the apical epithelium and a lack of lamellipodial extensions in the obese mouse. In the pre-Type 2 diabetic obese mouse there was a difference in the stiffness slope and after injury localization of fibronectin was negligible. These indicate that age and environmental changes incurred by diet alter the integrity of the tissue with age rendering it stiffer. The corneas from the pre-Type 2 diabetic obese mice were significantly softer and this may be a result of changes both in proteins on the apical surface indicating a lack of integrity and a decrease in fibronectin.<\/jats:p>","DOI":"10.3390\/bioengineering7010014","type":"journal-article","created":{"date-parts":[[2020,2,7]],"date-time":"2020-02-07T11:50:28Z","timestamp":1581076228000},"page":"14","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Changes in Epithelial and Stromal Corneal Stiffness Occur with Age and Obesity"],"prefix":"10.3390","volume":"7","author":[{"given":"Peiluo","family":"Xu","sequence":"first","affiliation":[{"name":"Department of Biomedical Engineering, Boston University, Boston, MA 02115, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7622-548X","authenticated-orcid":false,"given":"Anne","family":"Londregan","sequence":"additional","affiliation":[{"name":"Department of Biochemistry\/Molecular Biology, Boston University, Boston, MA 02215, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Celeste","family":"Rich","sequence":"additional","affiliation":[{"name":"Department of Biochemistry, Boston University School of Medicine, Boston, MA 02115, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Vickery","family":"Trinkaus-Randall","sequence":"additional","affiliation":[{"name":"Department of Biochemistry, Boston University School of Medicine, Boston, MA 02115, USA"},{"name":"Department of Ophthalmology, Boston University School of Medicine, Boston, MA 02115, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,2,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1016\/S0079-6107(02)00052-4","article-title":"Fluid shear stress and the vascular endothelium: For better and for worse","volume":"81","author":"Resnick","year":"2003","journal-title":"Prog. 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