IL-21 Enhances the Degradation of Cartilage Through the JAK-STAT Signaling Pathway During Osteonecrosis of Femoral Head Cartilage
IL-21 Enhances the Degradation of Cartilage Through the JAK-STAT Signaling Pathway During Osteonecrosis of Femoral Head Cartilage
复制标题
IL-21 在股骨头坏死过程中通过 JAK-STAT 信号通路增强软骨降解
DOI：
10.1007/s10753-017-0715-1
复制
发表时间：
2018-03-01
期刊：
影响因子：
5.1
通讯作者：
Cheng, Lei
中科院分区：
文献类型：
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作者：
Chen, Bin;Liu, Yi;Cheng, Lei
摘要本研究旨在探讨白细胞介素-21 （IL-21）在股骨头坏死发生机制中的作用。采用酶联免疫吸附试验（ELISA）检测股骨头坏死（ONFH）和股骨颈骨折（FNF）患者血清中IL-21的含量。软骨标本用红花素- o染色。免疫组化和western blot检测软骨组织中IL-21、肿瘤坏死因子-α (TNF-α)、环氧化酶（COX-2）、带血栓反应蛋白基元的崩解素和金属蛋白酶4 （ADAMTS-4）、基质金属蛋白酶13（MMP-13）、聚集蛋白的表达。用IL-21 （100 ng/mL）或PBS处理软骨细胞，RT-PCR检测TNF-α、COX-2、IL-1β和NOS-2 mRNA含量，western blot检测ADAMTS-4、MMP-13和aggrecan蛋白水平。在体外用IL-21刺激后测定JAK-STAT通路的活性。血清IL-21水平在ONFH患者中明显升高，且与ONFH严重程度呈正相关。ONFH患者软骨中IL-21、TNF-α、COX-2等炎性因子阳性细胞多于FNF患者。在ONFH患者中，某些相对生物标志物（如ADAMTS-4和MMP-13）的水平较高，而聚集蛋白水平较低。IL-21刺激后，TNF-α、COX-2、IL-1β、NOS-2 mRNA含量及ADAMTS-4、MMP-13水平均升高，聚集蛋白水平降低。IL-21刺激后p-STAT-1和p-STAT-3蛋白含量均升高，且在30 min时达到最高水平。AG-490刺激后，ADAMTS-4、MMP-13蛋白水平及TNF-α、COX-2、IL-1β、NOS-2 mRNA水平均显著降低。IL-21在ONFH患者软骨中通过JAK-STAT信号通路增强软骨炎症，促进软骨降解。
AbstractThis study aims to investigate the role of interleukin-21 (IL-21) in the mechanism of osteonecrosis of the femoral head. The serum content of IL-21 in patients with osteonecrosis of the femoral head (ONFH) and with femoral neck fracture (FNF) was examined by an enzyme-linked immunosorbent assay (ELISA). The cartilage specimens were stained with safranin-O. The expression of IL-21, tumor necrosis factor-α (TNF-α), cyclooxygenase (COX-2), a disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS-4), matrix metalloproteinase-13(MMP-13), and aggrecan in the cartilage was detected, by immunohistochemistry and western blot analysis. Moreover, chondrocytes were treated with IL-21 (100 ng/mL) or PBS to examine the mRNA content of TNF-α, COX-2, IL-1β and NOS-2 by RT-PCR, and the protein levels of ADAMTS-4, MMP-13, and aggrecan by western blot analysis. The activity of the JAK-STAT pathway was determinedin vitroafter stimulation with IL-21. IL-21 serum levels were obviously higher in the ONFH patients and positively correlated with the severity of ONFH. There were more cells positive for inflammatory cytokines, including IL-21, TNF-α, and COX-2, in the cartilage of the ONFH patients than the FNF patients. The level of certain relative biomarkers, such as ADAMTS-4 and MMP-13, was higher and aggrecan was lower in the ONFH patients. The mRNA contents of TNF-α, COX-2, IL-1β, and NOS-2, as well as the levels of ADAMTS-4, MMP-13, were enhanced, and aggrecan decreased after stimulation with IL-21. The protein content of p-STAT-1, as well as p-STAT-3, also increased after IL-21 stimulation, and the highest level appeared at 30 min. Furthermore, the protein level of ADAMTS-4 and MMP-13 and the mRNA level of TNF-α, COX-2, IL-1β, and NOS-2 significantly decreased after stimulation with AG-490. IL-21 enhances cartilage inflammation to promote cartilage degradation through the JAK-STAT signaling pathway in the cartilage of ONFH patients.