Direct protective effect of interleukin-10 on articular chondrocytes in vitro.
OBJECTIVE
To assess whether interleukin-10 (IL-10) is chondroprotective in vitro.


METHODS
Chondrocytes were isolated from femoral cartilage of rats (7-10 days) by digestion with collagenase II. The first passage cells were grown in 24- well plates with DMEM, supplemented with 10% fetal bovine serum, for 2-4 days. The cells were then cultured in 0.1% fetal bovine serum DMEM medium, and given respectively interleukin-1 (IL-1) 100 mu/ml, IL-1 100 mu/ml + recombinant murine interleukin-10 (rmIL-10) 20 ng/ml, rmIL-10 20 ng/ml, and cultured for 48 hours. Scanning electron morphology and immunohistochemical study of nitric oxide synthase 2 and matric metalloproteinase 3 mRNA in situ hybridization were performed. Cell proliferation and morphology were observed under inverted microscope from the beginning of cell culture for three weeks.


RESULTS
IL-1 stimulated granule production in the cytoplasma of chondrocytes, and the cells died in the second and third weeks of culture. IL-10 antagonized IL-1, protected the cells from death and maintained chondrocyte proliferation. Scanning electron morphology showed that IL-1 stimulated the formation of numerous microvilli on the cell surface, while thin and less numerous microvilli were found in cultures with IL-10. Immunohistochemical study and in situ hybridization showed that IL-10 inhibited NOS2 and MMP3 expression.


CONCLUSIONS
IL-10 not only inhibits the synthesis of inflammatory cytokines, but also directly protects chondrocytes by antagonizing IL-1.
Wang
Y
Y
Department of Orthopaedic Surgery, Third Hospital, Peking University, Beijing 100083, China.
Lou
S
S
D000818:Animals; D019902:Chondrocytes / Q000737:chemistry / Q000166:cytology / Q000187:drug effects*; D019610:Cytoprotection; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007375:Interleukin-1 / Q000037:antagonists & inhibitors; D016753:Interleukin-10 / Q000494:pharmacology*; D008855:Microscopy, Electron, Scanning; D020011:Protective Agents / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
D007375:Interleukin-1; D020011:Protective Agents; D016753:Interleukin-10