Wen Li1, Yanhui Liu2, Wanghui Ding3, Tan Long3, Jiejun Shi3. 1. Stomatology Hospital Affiliated to Medical College, Zhejiang University, China. Electronic address: ewen74@163.com. 2. The First Affiliated Hospital,Guangzhou University of Chinese Medicine, China. 3. Stomatology Hospital Affiliated to Medical College, Zhejiang University, China.
Abstract
OBJECTIVE: To study the protein expression of HIF-2α in condylar chondrocytes under the different stress loading, to investigate the possible effects of HIF-2α involved in the mortality of condylar chondrocytes under overloaded- stress. MATERIALS AND METHODS: Chondrocytes were isolated from TMJ condylar cartilage and cultured in hypoxia-incubator. Chondrocytes were divided into 4 groups: 0, 1000, 2000, 3000 ustrain group, which was subjected to cyclic tensile strain (CTS) of 0.5Hz for 2h. The rate of cell mortality was calculated. Western blot was used to measure the expression of HIF-2α and it's downstream catabolic factors (MMP3, MMP13, ADAMTS4) in protein levels respectively. RESULTS: With the increase of CTS, both of the rate of cell mortality and protein expression of HIF-2α increased significantly (p<0.05). The same tendency was also found in it's downstream catabolic factors (MMP3, MMP13, ADAMTS4) in protein levels (p<0.05). CONCLUSIONS: The results indicated that elevated expression of HIF-2α may be a possible mechanism related to overloaded- stress induced mortality of condylar chondrocytes.
OBJECTIVE: To study the protein expression of HIF-2α in condylar chondrocytes under the different stress loading, to investigate the possible effects of HIF-2α involved in the mortality of condylar chondrocytes under overloaded- stress. MATERIALS AND METHODS: Chondrocytes were isolated from TMJ condylar cartilage and cultured in hypoxia-incubator. Chondrocytes were divided into 4 groups: 0, 1000, 2000, 3000 ustrain group, which was subjected to cyclic tensile strain (CTS) of 0.5Hz for 2h. The rate of cell mortality was calculated. Western blot was used to measure the expression of HIF-2α and it's downstream catabolic factors (MMP3, MMP13, ADAMTS4) in protein levels respectively. RESULTS: With the increase of CTS, both of the rate of cell mortality and protein expression of HIF-2α increased significantly (p<0.05). The same tendency was also found in it's downstream catabolic factors (MMP3, MMP13, ADAMTS4) in protein levels (p<0.05). CONCLUSIONS: The results indicated that elevated expression of HIF-2α may be a possible mechanism related to overloaded- stress induced mortality of condylar chondrocytes.