摘要目的 探讨POSTN蛋白对老年大鼠膝胫骨平台软骨细胞增殖的影响.方法 体外分离培养20月龄SD雌性大鼠膝胫骨平台软骨细胞至第3代,分为3组:培养液注射POSTN蛋白组、注射PBS组、注射抗POSTN蛋白组,使用EDU检测软骨细胞增殖率.分别于24、48、72 h观测各组软骨细胞增殖情况,同时使用免疫组织化学技术观测软骨细胞中Notch1蛋白表达情况;20月龄SD大鼠30只,随机分为3组:注射POSTN蛋白组、注射PBS组、注射抗POSTN蛋白组.分别于1、3、5d连续向一侧膝关节腔注射3次相关试剂,并在1d时关节腔注射EDU,2周后处死大鼠取膝胫骨平台,观测软骨细胞增殖情况.组间比较使用单因素方差分析.结果 24 h时体外培养细胞增殖率3组间差异有统计学意义(F=27.32,P=0.017),注射POSTN蛋白组[(23±8)％]和PBS组[(21±10)％]细胞增殖率较抗POSTN蛋白组[(16±5)％]高(P=0.003,P=0.011);48 h时体外培养细胞增殖率3组间差异有统计学意义(F=35.34,P＜0.01),注射POSTN蛋白组细胞[(36±11)％]增殖率较其他2组[(22±6)％、(18±6)％]高(P=0.021,P＜0.01);72 h体外培养细胞增殖率3组间差异有统计学意义(F=52.62,P＜0.01),注射POSTN蛋白组细胞增殖率[(56±17)％]较注射PBS组[(31±8)％]、抗POSTN蛋白组[(26±7)％]高(P=0.007,P＜0.01),注射PBS组较注射抗POSTN蛋白组高(P＜0.01);Notch1蛋白在注射POSTN蛋白组软骨细胞表达最多,在抗POSTN蛋白组最少.大鼠膝内侧胫骨平台软骨细胞2周增殖率3组间差异有统计学意义(F=26.72,P＜0.01),关节腔注射POSTN蛋白组[(36±14)％]细胞增殖率较注射PBS组[(19±7)％]、注射抗POSTN蛋白组[(10±4)％]高(P=0.003,P＜0.01),注射PBS组较注射抗POSTN蛋白组细胞增殖率高(P=0.031).结论 POSTN蛋白可以促进老年大鼠膝胫骨平台软骨细胞的增殖,而抗POSTN蛋白可以减缓软骨细胞的增殖;POSTN蛋白可能通过激活Notch信号通路来促进软骨细胞的增殖.

abstractsObjective To investigate the effect of POSTN protein on the proliferation of chondrocytes of tibial plateau in old rats.Methods Cartilage cells collected from the tibial plateau of old rats were cultured in vitro to the third generation.Then the cells were divided into 3 groups:POSTN group,PBS group and POSTN antibody group.The proliferations of the three groups at 24 h,48 h and 72 h were determined by EDU method.The expression of Notch1 protein was detected by immunohistochemistry in all groups at the same time.Female 20-month-old Sprague-Dawley rats were randomly divided into 3 groups:POSTN protein injection group,Phosphate Buffered Saline (PBS) injection group and POSTN antibody injection group.Twelve weeks after the operation,related reagents were injected 3 times consecutively at day 1,day 3,day 5 and EDU was injected into joints at day 1.At 2 weeks after injection,the rats were killed and the knee tibial plateau was taken to observe the proliferation of the cartilage cells.Results At 24 h,there were differences between the three groups O(F=27.32,P=0.017).The proliferation rates of POSTN group [(23±8)％] and PBS group [(21±10)％] were higher than that of POSTN antibody group (16±5)(P=0.003,P=0.011).At 48 h,there were differences between the three groups (F=35.34,P＜0.01).The proliferation rate of POSTN group [(36±11)％] was higher than that of the other groups [(22±6)％],(18±6)％(P=0.021,P＜0.01).At 72h,there were differences between the three groups (F=52.62,P=0.000).The proliferation rate of POSTN group [(56±17)％] was the highest one,the proliferation rate of PBS group [(31±8)％] was the medium,and the POSTN antibody group [(26±7)％] was the lowest one (all P＜0.05).As for Notch1 protein expression in chondrocytes,there were differences between the three groups (F=26.72,P＜0.01).The Notch1 protein was the most frequently expressed in POSTN protein-injection group and the least in the anti-POSTN group.In rats,the proliferation rate of the chondrocytes in the medial tibia plateau of the knee of POSTN protein injection group [(36±14)％],which was the highest,and that of the POSTN antibody injection group [(10 ±4)％] was the lowest (all P＜0.05).Conclusion POSTN protein can promote the proliferation of chondrocytes knee OA rats.POSTN antibody injection has been shown to induce the proliferation of chondrocytes.The POSTN protein may promote the proliferation of chondrocytes by activating the Notch signaling pathway.