Study on antioxidant capacity of endplate chondrocytes from different ages in rats

English Keywords:Endplate chondrocytes  Antioxidant capacity  Ageing  Apoptosis

English Abstract:

  【Abstract】 Objectives: To explore the antioxidant capacity of aging on the endplate chondrocytes′ oxidative stress action in rats. Methods: Two kinds of endplate cartilage cells in primary generation were cultured. Cells were tested and passaged to the third generation for experiments. The cells were divided into two groups: group A was endplate chondrocytes from two-month rats; group B was endplate chondrocytes from 18-month rats. β-galactose dehydrogenase staining and PCR test on the relative length of telomere were used to compare their age difference. The total antioxidant capacity of the cell was determined by the total antioxidant capacity kits. Cells were intervented by a concentration of 200mmol/L of hydrogen peroxide for 2.5 hours. Before and after intervention by the same dose of hydrogen peroxide, RT-PCR was used to detect the expression of type Ⅱ collagen, proteoglycans, caspase-3 and bcl-2. Apoptosis of two different cells were compared by flow cytometry. The relative expressions of type Ⅱ collagen, proteoglycans, caspase-3 and bcl-2 were statistically analyzed by t test between two groups, P<0.05 meant statically significant. Results: Before intervention by the same dose of hydrogen peroxide, β-galactose dehydrogenase staining, expressions of type Ⅱ collagen, proteoglycans and apoptosis rate had no significant differences between 2 groups of endplate cartilage cells. The relative length of telomere was found significantly shorten in the aging rat origin and total antioxidant capacity was found significantly lower in group B. After the same dose of hydrogen peroxide stimulation, the expressions of type Ⅱ collagen and proteoglycans in group B were significantly lower than thoses in group A and the level of apoptosis rate was significantly higher than that in group A. Conclusions: Endplate cartilage cell under different ages has different antioxidant capacities. The older of the endplate cartilage cells, the lower ability to resist peroxidation.