Background and purpose

Osteoarthritis (OA) impacts the quality of life in middle-aged and elderly people by inducing immobility. The severe inflammation in chondrocytes is reported to be related to the development and process of OA. The present study aims to investigate the protective effects of Apremilast on injured chondrocytes induced by interleukin-1α (IL-1α) and the underlying mechanism.

Methods

10 ng/mL IL-1α was used to induce the in vitro injured chondrocytes. QRT-PCR was used to evaluate the expression level of Sry-type high-mobility-group box 9 (SOX-9), collagen type II alpha-1 gene (COL2A1), Aggrecan (ACAN) and collagen type X alpha 1 chain (COL10A1). SiRNA technology was utilized to knock down the expression of SOX-9 in the chondrocytes. The expression of SOX-9 was determined by Western Blot assay and/or immunofluorescence assay. Western Blot was used to evaluate the expression level of phosphorylated cyclic AMP response element binding (CREB).

Results

SOX9, Col2a1 and Acan were significantly up-regulated and Col10a1 was significantly down-regulated in the chondrocytes by Apremilast in a dose-dependent manner. IL-1α induced the injured chondrocytes by decreasing the expression of SOX9, Col2a1, Acan and increasing the expression of Col10a1, which were greatly reversed by Apremilast. By silencing SOX-9, the effects of Apremilast on SOX9 and marker genes were abolished. Phosphorylated CREB was up-regulated by Apremilast in a time-dependent manner. The up-regulated SOX-9 by Apremilast was reversed by the protein kinase A (PKA)/CREB pathway inhibitor H89.

Conclusion

Apremilast may protect chondrocytes from inflammation by up-regulating SOX9.

中文翻译：

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Apremilast在人软骨细胞中的抗炎能力取决于SOX-9

背景和目的

骨关节炎（OA）会导致不动，从而影响中老年人的生活质量。据报道，软骨细胞的严重炎症与OA的发生和发展有关。本研究旨在探讨Apremilast对白介素1α（IL-1α）诱导的软骨细胞损伤的保护作用及其潜在机制。

方法

10 ng / mLIL-1α用于诱导体外损伤的软骨细胞。QRT-PCR用于评估Sry型高迁移率族框9（SOX-9），II型胶原α-1基因（COL2A1），Aggrecan（ACAN）和X型胶原α1链的表达水平（ COL10A1）。SiRNA技术被用于敲低软骨细胞中SOX-9的表达。通过蛋白质印迹测定和/或免疫荧光测定确定SOX-9的表达。Western Blot用于评估磷酸化环状AMP反应元件结合（CREB）的表达水平。

结果

SOX9，COL2A1和ACAN均显著上调，COL10A1中以剂量依赖性方式通过软骨细胞被Apremilast显著下调。IL-1α通过减少SOX9，表达诱导受伤软骨细胞COL2A1，ACAN和增加的表达COL10A1，将其大大Apremilast逆转。通过沉默SOX-9，消除了Apremilast对SOX9和标记基因的影响。磷酸化的CREB被Apremilast上调，呈时间依赖性。Apremilast上调的SOX-9被蛋白激酶A（PKA）/ CREB途径抑制剂H89逆转。

结论

普雷米司可能通过上调SOX9来保护软骨细胞免于炎症。