Chondrocyte suppression is mediated by miR-129-5p via GDF11/SMAD3 signaling in developmental dysplasia of the hip
Chondrocyte suppression is mediated by miR-129-5p via GDF11/SMAD3 signaling in developmental dysplasia of the hip
复制标题
在髋关节发育不良中，软骨细胞抑制是由 miR-129-5p 通过 GDF11/SMAD3 信号传导介导的
DOI：
10.1002/jor.24713
复制
发表时间：
2020-05-22
影响因子：
2.8
通讯作者：
Jia, Jingyu
中科院分区：
文献类型：
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作者：
Liu, Xijuan;Deng, Xueqiang;Jia, Jingyu
最近的研究表明，儿童期和动物模型中的发育性髋关节发育不良（DDH）与髋臼顶部的软骨内骨化受损有关，但这种病理学的分子机制仍不清楚。为了解决这一问题，在4周龄新西兰白色兔中通过膝伸展的石膏固定建立DDH的动物模型。本研究共选取DDH家兔五十六只，其中雄兔21只，雌兔25只。高通量RNA测序鉴定了18个差异表达的microRNA;定量聚合酶链反应进一步证实了miR-129- 5 p下调。通过生物信息学和荧光素酶报告基因分析，初步确定生长分化因子11（GDF 11）为miR-129- 5 p的靶基因。miR-129- 5 p下调增加了GDF 11的表达，这诱导了SMAD家族成员3的磷酸化。其结果是，在体外的表达侏儒相关的转录因子2，印度刺猬同源物，和X型胶原蛋白被抑制。同时，茜素红S和Von Kossa染色显示，与对照组相比，miR-129- 5 P下调后软骨细胞形成的矿化结节减少。此外，增殖测定和流式细胞术证实了miR-129- 5 p下调后软骨细胞增殖和G1细胞周期停滞的抑制。这些发现表明miR-129- 5 p能够通过miR-129- 5 p/GDF 11/SMAD 3轴抑制软骨细胞增殖和肥大分化并减少矿化。这可能是观察到的髋臼顶DDH相关骨化损伤的根本原因。
Recent studies have shown that developmental dysplasia of the hip (DDH) during childhood and in animal models is associated with impaired endochondral ossification of the roof of the acetabulum, yet the molecular mechanism of this pathology remains unknown. To address this, an animal model of DDH was established in 4-week-old New Zealand white rabbits by cast immobilization of knee extension. Fifty-six rabbits of DDH were involved in this study, including 21 male rabbits and 25 female rabbits. High-throughput RNA sequencing identified 18 differentially expressed microRNAs; miR-129-5p downregulation was further confirmed by quantitative polymerase chain reaction. Bioinformatics and luciferase reporter assay identified growth differentiation factor 11 (GDF11) as the target gene of miR-129-5p in vitro. miR-129-5p downregulation increased GDF11 expression, which induced the phosphorylation of SMAD family member 3. As a result, the expression of runt-related transcription factor 2, Indian hedgehog homolog, and collagen type X was inhibited in vitro. Meanwhile, Alizarin Red S and Von Kossa staining revealed reduced formation of mineralized nodules by chondrocytes after miR-129-5P downregulation compared with the control. Additionally, proliferation assays and flow cytometry confirmed the suppression of chondrocyte proliferation and G1 cell cycle arrest following miR-129-5p downregulation. These findings indicate that miR-129-5p is able to suppress chondrocyte proliferation and hypertrophic differentiation and decrease mineralization via the miR-129-5p/GDF11/SMAD3 axis. This could present the underlying cause for the observed DDH-associated ossification impairment of the acetabular roof.