不同牵伸强度对体外人肌腱细胞磷脂酶A2/环氧合酶表达的影响

目的 探讨不同循环牵伸强度对体外人肌腱细胞磷脂酶A2(phospholipase A2，PLA2)和环氧合酶(cyclooxygenase，COX)表达的影响。 方法 取4～6代人肌腱细胞在0.5 Hz、4h条件下施加不同牵伸强度(4％、8％、12％)，未牵伸组设为对照组。静置4h后，用RT-PCR、Western blot检测胞浆性PLA2(cytosolic PLA.2，cPLA2)、COX1、COX2的表达，ELISA测定分泌性PLA2 (secretory PLA2，sPLA2)的表达。 结果 对照组、4％、8％、12％牵伸组cPLA2、COX1、COX2基因表达随牵伸强度增加呈递增趋势，4％牵伸组cPLA2、COX1蛋白表达与对照组比较增加均不明显，差异无统计学意义(P＞0.05)；8％和12％牵伸组cPLA2及COX1蛋白表达与对照组比较明显增加，差异有统计学意义(P＜0.01)。4％、8％、12％牵伸组COX2与对照组比较，差异均有统计学意义(P＜0.01)，且随牵伸强度增加而逐渐增加。sPLA2在4％牵伸组分泌量和对照组比较，差异无统计学意义(P＞0.05)，8％和12％牵伸组增加明显(P＜0.01)。 结论 体外人肌腱细胞PLA2、COX1、COX2的表达与牵伸强度呈正相关，PLA2/COX调节系统可能成为防治肌腱病的新分子靶标。

Effect of different cyclic stretching strengths on expressions of phospholipase A2 and cyclooxygenase in human tenocytes in vitro

Objective To investigate the effect of different cyclic strengths on expressions of phospholipase A2 (PLA2) and cyclooxygenase (COX) in human tenocytes. Methods Human 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.