Effect of different cyclic stretching strengths on expressions of phospholipase A2 and cyclooxygenase in human tenocytes in vitro / 中华创伤杂志

ABSTRACT

ObjectiveTo investigate the effect of different cyclic strengths on expressions of phospholipase A2 (PLA2) and cyclooxygenase (COX) in human tenocytes.MethodsHuman tenocytes were uniaxially stretched with different stretching intensity (4％, 8％ and 12％) under 0.5 Hz for four hours.Non-stretched tenocytes were applied to the control group.The expressions of cytosolic PLA2(cPLA2), COX1 and COX2 were measured by Western blot and RT-PCR.The secretion of secretory PLA2 (sPLA2) was measured by ELISA.Results The mRNA expressions of cPLA2, COX1 and COX2 in control group, 4％, 8％ and 12％ stretch groups showed an increase trend.But protein expressions of cPLA2 and COX1 in 4％ stretch group were increased insignificantly compared with the control group (P ＞ 0.05).Protein expressions of cPLA2 and COX1 in 8％ and 12％ stretch groups were increased more significantly compared with the control group (P ＜ 0.01).The COX2 expression in 4％,8％ and 12％ stretch groups showed statistical difference compared with that in the control group (P ＜0.01) and the difference increased with stretch intensity.There was no different expression of sPLA2 between 4％ stretch group and control group (P = 0.260).However, expression of sPLA2 was increased markedly in 8％ and 12％ stretch groups (P ＜ 0.01).ConclusionsThe expressions of human tendnocytes PLA2, COX1 and COX2 in vitro are positively correlated with stretch intensity.PLA2/COX system may be a new molecule target in clinical treatment of tendinopathy.