Effects of frequency on osteoblast apoptosis induced by tensile strain
10.16156/j.1004-7220.2017.05.012
- VernacularTitle:频率对拉伸应变诱导成骨细胞凋亡的影响
- Author:
Fan MENG
1
;
Hui LI
;
Zi YE
;
Wei-Xin LI
;
Lu LIU
Author Information
1. 武警后勤学院
- Keywords:
Osteoblasts;
Tensile strain;
Cell apoptosis;
Frequency
- From:
Journal of Medical Biomechanics
2017;32(5):464-468,480
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effect of frequency on osteoblast apoptosis induced by tensile strain.Methods MC3T3-E1 cells were applied with 1％ biaxial tensile strain at the frequency of 1,2,3,4,5 Hz,re spectively for 1 hour per day in 8 days.The survival rate of the cells was determined by activity of lactate dehydrogenase (LDH).Annexin V-FITC/ PI Flow cytometry was used to test cell apoptosis.Real-time RT-PCR was used to detect the gene level of apoptosis markers caspase-3,-9 as well as Bcl-2 and Bax,and Western blotting was used to test protein expressions of caspase-3,-9.Results Different loading frequencies had no effect on osteoblast activity of LDH.There was no significant difference in the total apoptosis rate of flow cytometry at different frequencies.However,the frequency of 2 Hz could induce early osteoblast apoptosis.Tensile strain at the frequency of 2 Hz could significantly increase the expression of caspase-3,-9 gene and protein,and induce cell apoptosis with the up-regulation of the Bax/Bcl-2.Conclusions Osteoblast apoptosis and death cannot be induced by 1％ biaxial tensile strain at the frequency of 1-5 Hz,but the frequency of 2 Hz can induce the early apoptosis of osteoblasts by up-regulating the expression of Bax/BCI-2.
