程序性坏死在髁突软骨退变中的作用

The effects of necroptosis on the development of condylar cartilage degeneration

目的:探究程序性坏死(Necroptosis)在髁突软骨退变中的作用。方法:48只SD大鼠随机分为对照(Con)组、雌激素补充(E 2)组、单侧前牙反(UAC)组、单侧前牙反+雌激素补充(U+E 2)组(n=12),3周后处死、取材。HE、番红O-固绿染色评价软骨退变程度;免疫组化及Western blot检测髁突软骨中Necroptosis关键分子RIPK3、p-MLKL,损伤相关模式分子HMGB1和促炎/降解因子TNF-α、MMP13、ADAMTS5的表达。结果:与Con组相比,E 2、UAC和U+E 2组软骨厚度、番红O阳性面积比显著降低(P<0.01);RIPK3、p-MLKL、HMGB1、TNF-α阳性细胞率及蛋白表达显著升高(P<0.05)。UAC和U+E 2组中MMP13、ADAMTS5蛋白表达量显著高于Con组(P<0.01)。结论:髁突软骨细胞程序性坏死参与了髁突软骨的退变进程。

Objective:To explore the effects of necroptosis on the development of mandibular condylar cartilage degeneration in rats.Methods:48 SD rats were randomly divided into control(Con),estrogen supplement(E 2),unilateral anterior crossbite(UAC)and UAC with estrogen supplement(U+E 2)groups(n=12).All rats were sacrificed 3 weeks later.HE and Safranin O staining were performed to evaluate the degree of condylar cartilage degeneration.Immunohistochemical staining and western blot were used to detect the expression of crucial molecules of necroptosis(RIPK3,p-MLKL),damage associated molecular patterns(HMGB1)and pro-inflammatory and catabolic cytokines(TNF-α,MMP13,ADAMTS5)in cartilage.Results:Compared with Con group,there was a significant decrease in the thickness of cartilage and positive area of Safranin O staining(P<0.01),accompany with a significant increase in the percentage of positive chondrocytes and the expression of RIPK3,p-MLKL,TNF-αand HMGB1(P<0.05)in E 2,UAC and UAC+E 2 groups.The expression of MMP13 and ADAMTS5 was significantly higher in UAC and U+E 2 group than that in Con group(P<0.01).Conclusion:Necroptosis of condylar chondrocytes is involved in the development of condylar cartilage degeneration.