OBJECTIVETo explore the expression characteristics of new mechanosensitive ion channel Piezo1 protein in stress models of human degenerative chondrocytes.

METHODSThe stress stimulation model of human degenerative chondrocytes in vitro was constructed. Multi-channel cell stretch stress loading system FX-4000T was used to treat chondrocytes. According to the results of pre-test, the loading frequency of 0.5 Hz and the cell elongation of 20% were loaded. According to cell processing time, it was divided into 0 h, 2 h, 12 h, 24 h and 48 h mechanical stress group. The RT-PCR and Western-blot were used to test the expression of the Piezo1, also the Laser scanning confocal microscope (LSCM) was used to test the intensity of the fluorescence of the Piezo1.

RESULTS(1)The result of the RT-PCR showed that the expression of the Piezo1 in the 2 h group was higher than the 0 h group(13.917, 0.037 1, <0.05). The expression of the piezo1 in the 24 h group was the highest. While the expression of the piezo1 in the 48 h group was lower than the expression of the piezo1 in the 24 h group(13.917, 0.049 5, <0.05). (2)The result of the Western-blot showed that the 2 h group was higher than the 0 h group(19.341, 0.037 1, <0.05). The expression of the 24 h had the highest expression which was higher than the 48 h group(19.341, 0.017 7, <0.05). (3)The Piezo1 protein was extensively expressed in the cytoplasm and nucleus of the nucleus pulposus cells. And with the increase of stress processing time, the fluorescence intensity of the protein also increased.

CONCLUSIONSIn human degeneration cartilage cells, the new mechanio sensitive ion channel Piezo1 protein has a trace expression. After loading periodic mechanical tensile force, the expression of Piezo1 protein increases with time dependence.