Intercellular calcium signalling between chondrocytes and synovial cells in co-culture.
Intercellular communication allows the co-ordination of cell metabolism between tissues as well as sensitivity to extracellular stimuli. Paracrine stimulation and cell-to-cell coupling through gap junctions induce the formation of complex cellular networks that favour the intercellular exchange of nutrients and second messengers. Heterologous intercellular communication was studied in co-cultures of articular chondrocytes and HIG-82 synovial cells by measuring mechanically induced cytosolic changes in Ca2+ ion levels by digital fluorescence video imaging. In confluent co-cultures, mechanical stimulation induced intercellular Ca2+ waves that propagated to both cell types with similar kinetics. Intercellular wave spreading was inhibited by 18alpha-glycyrrhetinic acid and by treatments inhibiting the activation of purinoreceptors, suggesting that intercellular signalling between these two cell types occurs both through gap junctions and ATP-mediated paracrine stimulation. In rheumatoid arthritis the formation of the synovial pannus induces structural changes at the chondrosynovial junction, where chondrocyte and synovial cells come into close apposition: these results provide the first evidence for direct intercellular communication between these two cell types.
D'andrea
P
P
Dipartimento di Biochimica, Biofisica e Chimica delle Macromolecole, Università di Trieste, Italy.
Calabrese
A
A
Grandolfo
M
M
D000255:Adenosine Triphosphate / Q000502:physiology; D000818:Animals; D002118:Calcium / Q000502:physiology*; D002358:Cartilage, Articular; D002450:Cell Communication / Q000502:physiology*; D002460:Cell Line; D002478:Cells, Cultured; D019902:Chondrocytes / Q000502:physiology*; D018920:Coculture Techniques; D005110:Extracellular Space / Q000502:physiology*; D008846:Micromanipulation; D011817:Rabbits; D015398:Signal Transduction; D013314:Stress, Mechanical; D013583:Synovial Membrane / Q000166:cytology / Q000502:physiology*
D000255:Adenosine Triphosphate; D002118:Calcium