Arthritis Center, Department of Internal Medicine and Medical Specialties, Sapienza University of Rome, Rome, Italy.
Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy.
Arthritis Res Ther. 2019 Jan 29;21(1):39. doi: 10.1186/s13075-019-1818-x.
Autophagy has emerged as a key mechanism in the survival and function of T and B lymphocytes, and its activation was involved in apoptosis resistance in rheumatoid arthritis (RA). To investigate whether the relationship between autophagy and apoptosis may impact the response to the therapy, we analyzed ex vivo spontaneous autophagy and apoptosis in patients with RA subjected to treatment with anti-tumor necrosis factor (TNF) drugs and in vitro the effects of TNFα and anti-TNF drugs on cell fate.
Peripheral blood mononuclear cells (PBMCs) from 25 RA patients treated with anti-TNF drugs were analyzed for levels of autophagy marker LC3-II by western blot and for the percentage of annexin V-positive apoptotic cells by flow cytometry. The same techniques were used to assess autophagy and apoptosis after in vitro treatment with TNFα and etanercept in both PBMCs and fibroblast-like synoviocytes (FLS) from patients with RA.
PBMCs from patients with RA responsive to treatment showed a significant reduction in LC3-II levels, associated with an increased apoptotic activation after 4 months of therapy with anti-TNF drugs. Additionally, the expression of LC3-II correlated with DAS28. TNFα was able to induce autophagy in a dose-dependent manner after 24 h of culture in RA PBMCs and FLS. Moreover, etanercept caused a significant reduction of autophagy and of levels of citrullinated proteins.
Our results show how the crosstalk between autophagy and apoptosis can sustain the survival of immune cells, thus influencing RA progression. This suggests that inhibition of autophagy represents a possible therapeutic target in RA.
自噬已成为 T 和 B 淋巴细胞存活和功能的关键机制，其激活与类风湿关节炎（RA）中的凋亡抵抗有关。为了研究自噬与凋亡之间的关系是否会影响对治疗的反应，我们分析了接受抗肿瘤坏死因子（TNF）药物治疗的 RA 患者的体外自发性自噬和凋亡，以及 TNFα 和抗 TNF 药物对细胞命运的影响。
通过 Western blot 分析接受抗 TNF 药物治疗的 25 例 RA 患者外周血单核细胞（PBMC）中自噬标志物 LC3-II 的水平，并通过流式细胞术分析 annexin V 阳性凋亡细胞的百分比。同样的技术用于评估 TNFα 和依那西普在 RA 患者的 PBMC 和成纤维样滑膜细胞（FLS）中的体外自噬和凋亡。
治疗反应良好的 RA 患者的 PBMC 中 LC3-II 水平显著降低，与治疗 4 个月后抗 TNF 药物治疗引起的凋亡激活增加相关。此外，LC3-II 的表达与 DAS28 相关。TNFα 在 RA PBMC 和 FLS 培养 24 小时后可呈剂量依赖性诱导自噬。此外，依那西普可显著减少自噬和瓜氨酸化蛋白的水平。
我们的研究结果表明，自噬和凋亡之间的相互作用如何维持免疫细胞的存活，从而影响 RA 的进展。这表明抑制自噬可能是 RA 的一个潜在治疗靶点。
