Age-Related Changes in the Expression of Cadherin-11, the Mesenchyme Specific Calcium-Dependent Cell Adhesion Molecule

Cadherin-11 is a calcium-dependent cell adhesion molecule that is expressed in cells of the mesenchymal lineage during embryonic development. In this study we show, for the first time, that cadherin-11 gene is expressed in the bone marrow and bone cells obtained from rabbits of various age groups. Furthermore, a quantitative measurement of gene expression revealed that cadherin-11 was expressed in young rabbits (6 week-old: open epiphysis) at a level of 6.7 × 10⁵± 0.7 × 10⁵ molecules; in mature rabbits (8–10 month-old: closed epiphysis) at 11 × 10⁵± 0.9 × 10⁵ molecules; and in aged rabbits (4–5 year-old) at a level of 1.2 × 10⁵± 0.2 × 10⁵ molecules/μg total RNA. The relative level of cadherin-11 gene expression in mature rabbit marrow was found to be approximately 50% greater than in young rabbits. However, aged animals showed a reduction in cadherin-11 specific gene expression of greater than 900% as compared with mature animals. Age-related changes in bone remodeling/turnover lead to reduced bone density and high fracture risk, and since cadherins play a crucial role in tissue morphogenesis, this marked decrease may represent an index of the aging process in bone. Received: 2 January 1997 / Accepted: 29 September 1997