Objective: To observe apoptosis of chondrocytes in cartilage and arthritis.
Methods: Apoptosis was detected by light and electron microscope and DNA electrophoresis, while [Ca2+]i was detected by confocal laser scanning microscope.
Results: Cartilage cells from osteoarthritis (OA) and rheumatoid arthritis (RA) could be seen to undergo normal differentiation after cultured for 3 days under light or electron microscope, while some chondrocytes directly isolated without culturing could give early changes of apoptosis, and normal chondrocytes in vitro after treatment with IL-1, TNF-alpha also underwent apoptosis. IL-1, TNF-alpha could induce increase of [Ca2+]i in chondrocytes.
Conclusions: Our data showed that apoptosis might present in the normal cartilage as well as in OA and RA cells. IL-1, TNF-alpha could induce apoptosis of chondrocytes and [Ca2+]i increase during apoptosis.