{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,2]],"date-time":"2026-02-02T00:26:19Z","timestamp":1769991979809,"version":"3.49.0"},"reference-count":33,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2022,7,22]],"date-time":"2022-07-22T00:00:00Z","timestamp":1658448000000},"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","id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Endocrinol."],"abstract":"<jats:p>To study the role of Claudin (CLDN)12 in bone, we developed mice with a targeted deletion of exon2 in the <jats:italic>Cldn12<\/jats:italic> gene for skeletal phenotype analysis. Micro-CT analysis of the secondary spongiosa of distal femurs of mice with targeted disruption of the <jats:italic>Cldn12<\/jats:italic> gene and control littermates showed no significant genotype-specific differences in either cortical or trabecular bone parameters for either gender in 13-week-old mice. Immunohistochemistry revealed that while CLDN12 was expressed in both differentiating chondrocytes and osteoblasts of the secondary spongiosa of 3-week-old wild-type mice, its expression was restricted to differentiating chondrocytes in the articular cartilage and growth plate in adult mice. Articular cartilage area at the knee were increased by 47% in <jats:italic>Cldn12<\/jats:italic> knockout (KO) mice compared to control littermates. Micro-CT analyses found that while the trabecular number was increased by 9% and the trabecular spacing was reduced by 9% in the femoral epiphysis of <jats:italic>Cldn12<\/jats:italic> KO mice, neither bone volume nor bone volume adjusted for tissue volume was different between the two genotypes. The expression levels of <jats:italic>Clusterin<\/jats:italic>, <jats:italic>Lubricin<\/jats:italic> and <jats:italic>Mmp13<\/jats:italic> were increased by 56%, 46%, and 129%, respectively, in primary articular chondrocytes derived from KO compared to control mice. Our data indicate that targeted deletion of the <jats:italic>Cldn12<\/jats:italic> gene in mice increases articular cartilage, in part, by promoting articular chondrocyte phenotype.<\/jats:p>","DOI":"10.3389\/fendo.2022.931318","type":"journal-article","created":{"date-parts":[[2022,7,22]],"date-time":"2022-07-22T12:05:08Z","timestamp":1658491508000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":3,"title":["Targeted Deletion of the Claudin12 Gene in Mice Increases Articular Cartilage and Inhibits Chondrocyte 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