CHONDROCYTES ISOLATED FROM MATURE ARTICULAR-CARTILAGE RETAIN THE CAPACITY TO FORM FUNCTIONAL GAP-JUNCTIONS

The distribution, expression, and functionality of gap junctions was e xamined in bovine chondrocytes (BCs) isolated from mature articular ca rtilage, BC cells displayed immunoreactivity for connexin 43 (Cx43), a specific gap junction protein, Cx43 protein expression was confirmed by Western blot analysis, and Cx43 mRNA was detected by nuclease prote ction assay, Additionally, BCs were shown to be functionally coupled, as revealed by dye transfer studies, and octanol, a gap junction uncou pler, greatly attenuated coupling, Furthermore, confocal microscopy of fluo-3 loaded BC cells revealed that deformation-induced cytosolic Ca 2+ ion (Ca2+) signals propagated from cell-to-cell via gap junctions. To our knowledge, this is the first evidence suggesting that chondrocy tes isolated from adult articular cartilage express functional gap jun ctions.