Abstract: Objective:To explore the mRNA expressions of matrix metalloproteinases(MMPs) in rabbit articular chondrocytes at different time-points after injury.Methods:The rabbit knee joint cartilage cells were obtained under sterile condition,primarily cultured in vitro,and established the cell scratch model in six-well plates.The proliferation of chondrocytes after 1,3 and 7 days of scratching and normal cells were observed under the microscope.The MMPs mRNA expression levels in normal cells and different time-points after injury were detected using real-time PCR.Results:The articular chordrocyte was successfully isolated,the scratch model of chondrocytes was established after primary culture.Compared with normal cells,the mRNA expression levels of MMP-2 gene in chondrocytes increased at 1,3 and 7 days aftere injury,and which was the highest on the seventh day(P<0.05 to P<0.01).Compared with normal cells,the mRNA expression levels of MMP-3 gene in chondrocytes decreased significantly at 1,3 and 7 days after injury,and which was the lowest at on the seventh day(P<0.01).Compared with normal cells,the mRNA expression levels of MMP-9 gene in chondrocytes increased at 1,3 and 7 days after injury,and which was the highest on the third day and then began to decrease(P<0.01).Conclusions:The mRNA expression levels of MMPs are different after injury,which can provide the experimental evidence in gene therapy of articular cartilage injury.