炎症小体激活与强直性脊柱炎肠菌失调有关。

Inflammasome Activation in Ankylosing Spondylitis Is Associated With Gut Dysbiosis.

机构信息

University of Palermo, Palermo, Italy.

Università degli Studi della Campania Luigi Vanvitelli, Naples, Italy.

出版信息

Arthritis Rheumatol. 2021 Jul;73(7):1189-1199. doi: 10.1002/art.41644. Epub 2021 May 25.

DOI:10.1002/art.41644

PMID:33452867

Abstract

OBJECTIVE

We undertook this study to evaluate the activation and functional relevance of inflammasome pathways in ankylosing spondylitis (AS) patients and rodent models and their relationship to dysbiosis.

METHODS

An inflammasome pathway was evaluated in the gut and peripheral blood from 40 AS patients using quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR), immunohistochemistry (IHC), flow cytometry, and confocal microscopy, and was compared to that of 20 healthy controls and 10 patients with Crohn's disease. Bacteria was visualized using silver stain in human samples, and antibiotics were administered to HLA-B27-transgenic rats. The NLRP3 inhibitor MCC950 was administered to SKG mice, and ileal and joint tissues were assessed by IHC analysis and real-time qRT-PCR. The role of inflammasome in modulating the interleukin-23 (IL-23)/IL-17 axis was studied ex vivo.

RESULTS

Expression levels of Nlrp3, Nlrc4, and Aim2 were increased in the gut of HLA-B27-transgenic rats and reduced by antibiotic treatment (P < 0.05). In curdlan-treated SKG mice, NLRP3 blockade prevented ileitis and delayed arthritis onset (P < 0.05). Compared to healthy controls, AS patients demonstrated overexpression of NLRP3 (fold induction 2.33 versus 22.2; P < 0.001), NLRC4 (fold induction 1.90 versus 6.47; P < 0.001), AIM2 (fold induction 2.40 versus 20.8; P < 0.001), CASP1 (fold induction 2.53 versus 24.8; P < 0.001), IL1B (fold induction 1.07 versus 10.93; P < 0.001), and IL18 (fold induction 2.56 versus 15.67; P < 0.001) in the ileum, and caspase 1 activity was increased (P < 0.01). The score of adherent and invasive mucosa-associated bacteria was higher in AS (P < 0.01) and correlated with the expression of inflammasome components in peripheral blood mononuclear cells (P < 0.001). NLRP3 expression was associated with disease activity (the Ankylosing Spondylitis Disease Activity Score using the C-reactive protein level) (r = 0.28, P < 0.01) and with IL23A expression (r = 0.34, P < 0.001). In vitro, inflammasome activation in AS monocytes was paralleled by increased serum levels of IL-1β and IL-18. Induction of IL23A, IL17A, and IL22 was IL-1β-dependent.

CONCLUSION

Inflammasome activation occurs in rodent models of AS and in AS patients, is associated with dysbiosis, and is involved in triggering ileitis in SKG mice. Inflammasomes drive type III cytokine production with an IL-1β-dependent mechanism in AS patients.

摘要

目的

我们进行这项研究旨在评估炎症小体途径在强直性脊柱炎（AS）患者和啮齿动物模型中的激活和功能相关性，并研究其与肠道菌群失调的关系。

方法

通过定量逆转录聚合酶链反应（qRT-PCR）、免疫组织化学（IHC）、流式细胞术和共聚焦显微镜评估 40 例 AS 患者和 20 例健康对照者及 10 例克罗恩病患者的肠道和外周血中的炎症小体途径，并进行比较。使用银染法在人样本中观察细菌，并用抗生素处理 HLA-B27 转基因大鼠。给 SKG 小鼠使用 NLRP3 抑制剂 MCC950，并通过 IHC 分析和实时 qRT-PCR 评估回肠和关节组织。体外研究炎症小体在调节白细胞介素 23（IL-23）/IL-17 轴中的作用。

结果

HLA-B27 转基因大鼠的肠道中 Nlrp3、Nlrc4 和 Aim2 的表达水平升高，经抗生素治疗后降低（P < 0.05）。在卷曲霉素处理的 SKG 小鼠中，NLRP3 阻断可预防回肠炎并延迟关节炎发病（P < 0.05）。与健康对照组相比，AS 患者的 NLRP3（诱导倍数 2.33 比 22.2；P < 0.001）、NLRC4（诱导倍数 1.90 比 6.47；P < 0.001）、AIM2（诱导倍数 2.40 比 20.8；P < 0.001）、CASP1（诱导倍数 2.53 比 24.8；P < 0.001）、IL1B（诱导倍数 1.07 比 10.93；P < 0.001）和 IL18（诱导倍数 2.56 比 15.67；P < 0.001）在回肠中的表达增加，且 caspase 1 活性升高（P < 0.01）。AS 患者的黏附性和侵袭性黏膜相关细菌评分较高（P < 0.01），且与外周血单核细胞中炎症小体成分的表达相关（P < 0.001）。NLRP3 表达与疾病活动度（使用 C 反应蛋白水平的强直性脊柱炎疾病活动评分）相关（r = 0.28，P < 0.01），且与 IL23A 表达相关（r = 0.34，P < 0.001）。体外，AS 单核细胞中的炎症小体激活与血清中 IL-1β 和 IL-18 水平升高相关。IL23A、IL17A 和 IL22 的诱导与 IL-1β 依赖。