Department of spine surgery, Shandong Provincial Hospital affiliated to Shandong First Medical University, Jinan, China.
Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital Affiliated to Shandong University, Jinan, China.
J Cell Mol Med. 2021 Jun;25(12):5671-5680. doi: 10.1111/jcmm.16581. Epub 2021 May 3.
Iron overload is common in elderly people which is implicated in the disease progression of osteoarthritis (OA), however, how iron homeostasis is regulated during the onset and progression of OA and how it contributes to the pathological transition of articular chondrocytes remain unknown. In the present study, we developed an in vitro approach to investigate the roles of iron homeostasis and iron overload mediated oxidative stress in chondrocytes under an inflammatory environment. We found that pro-inflammatory cytokines could disrupt chondrocytes iron homeostasis via upregulating iron influx transporter TfR1 and downregulating iron efflux transporter FPN, thus leading to chondrocytes iron overload. Iron overload would promote the expression of chondrocytes catabolic markers, MMP3 and MMP13 expression. In addition, we found that oxidative stress and mitochondrial dysfunction played important roles in iron overload-induced cartilage degeneration, reducing iron concentration using iron chelator or antioxidant drugs could inhibit iron overload-induced OA-related catabolic markers and mitochondrial dysfunction. Our results suggest that pro-inflammatory cytokines could disrupt chondrocytes iron homeostasis and promote iron influx, iron overload-induced oxidative stress and mitochondrial dysfunction play important roles in iron overload-induced cartilage degeneration.
铁过载在老年人中很常见,这与骨关节炎(OA)的疾病进展有关,然而,铁稳态在 OA 的发生和进展中是如何调节的,以及它如何促进关节软骨细胞的病理转化仍然未知。在本研究中,我们开发了一种体外方法来研究铁稳态和铁过载介导的氧化应激在炎症环境下对软骨细胞的作用。我们发现,促炎细胞因子可以通过上调铁摄取转运蛋白 TfR1 和下调铁输出转运蛋白 FPN 来破坏软骨细胞的铁稳态,从而导致软骨细胞铁过载。铁过载会促进软骨细胞分解代谢标志物的表达,如 MMP3 和 MMP13。此外,我们发现氧化应激和线粒体功能障碍在铁过载诱导的软骨退化中起着重要作用,使用铁螯合剂或抗氧化药物降低铁浓度可以抑制铁过载诱导的 OA 相关分解代谢标志物和线粒体功能障碍。我们的结果表明,促炎细胞因子可以破坏软骨细胞的铁稳态并促进铁内流,铁过载诱导的氧化应激和线粒体功能障碍在铁过载诱导的软骨退化中起着重要作用。