Chondromodulin-I (Cnmd), also known as Chm-1, Chm-I, or Lect1, is a type II transmembrane glycoprotein-encoding gene. It is primarily expressed in cartilage and healthy cardiac valves. Cnmd plays a vital role in chondrocyte proliferation, cartilage homeostasis, and angiogenesis blocking, which are essential for endochondral ossification and tissue development, homeostasis, repair, and regeneration [1,3].

In Cnmd null (Cnmd -/-) mice, less cartilage callus was observed during distraction osteogenesis, and the distraction gap was filled by fibrous tissues. Radiological and histological investigations demonstrated delayed bone consolidation and remodeling of the lengthened segment. Eventually, Cnmd deficiency caused a one-week delay in the peak expression of VEGF, MMP2, and MMP9 genes, as well as subsequent angiogenesis and osteoclastogenesis, indicating that Cnmd is necessary for cartilage callus distraction [2].

In conclusion, Cnmd is crucial for cartilage-related biological processes, especially in cartilage callus distraction as revealed by Cnmd KO mouse models. Its role in regulating angiogenesis and chondrocyte-related functions may have implications for understanding and treating diseases such as osteoarthritis, where its down-regulation correlates with disease severity [1,2,3].

References:

1. Reyes Alcaraz, Viviana, Pattappa, Girish, Miura, Shigenori, Shukunami, Chisa, Docheva, Denitsa. 2024. A Narrative Review of the Roles of Chondromodulin-I (Cnmd) in Adult Cartilage Tissue. In International journal of molecular sciences, 25, . doi:10.3390/ijms25115839. https://pubmed.ncbi.nlm.nih.gov/38892027/

2. Yukata, Kiminori, Shukunami, Chisa, Matsui, Yoshito, Hiraki, Yuji, Yasui, Natsuo. 2023. Chondromodulin is necessary for cartilage callus distraction in mice. In PloS one, 18, e0280634. doi:10.1371/journal.pone.0280634. https://pubmed.ncbi.nlm.nih.gov/36795722/

3. Zhu, Sipin, Qiu, Heng, Bennett, Samuel, Xu, Huazi, Xu, Jiake. 2019. Chondromodulin-1 in health, osteoarthritis, cancer, and heart disease. In Cellular and molecular life sciences : CMLS, 76, 4493-4502. doi:10.1007/s00018-019-03225-y. https://pubmed.ncbi.nlm.nih.gov/31317206/