1. Academic Validation
  2. Endoplasmic reticulum aminopeptidase 2 regulates CD4+ T cells pyroptosis in rheumatoid arthritis

Endoplasmic reticulum aminopeptidase 2 regulates CD4+ T cells pyroptosis in rheumatoid arthritis

  • Arthritis Res Ther. 2024 Jan 25;26(1):36. doi: 10.1186/s13075-024-03271-3.
Jianhua Zhang # 1 Hao Cai # 1 Weiwei Sun # 1 Weijie Wu 1 Yunyi Nan 1 Yingchen Ni 1 Xinyuan Wu 1 Minhao Chen 2 Hua Xu 3 Youhua Wang 4
Affiliations

Affiliations

  • 1 Department of Orthopaedics, Affiliated Hospital of Nantong University, Nantong, Jiangsu, China.
  • 2 Department of Orthopaedics, Affiliated Hospital of Nantong University, Nantong, Jiangsu, China. chenminhao_nt@126.com.
  • 3 Department of Orthopaedics, Affiliated Hospital of Nantong University, Nantong, Jiangsu, China. xuhua1981111@126.com.
  • 4 Department of Orthopaedics, Affiliated Hospital of Nantong University, Nantong, Jiangsu, China. wangyouhua99@163.com.
  • # Contributed equally.
Abstract

Objective: Rheumatoid arthritis (RA) is a chronic, progressive autoimmune disease with a complex pathogenesis that has not yet been fully elucidated, and T-cell Pyroptosis is an important pathogenetic factor in RA. This study aimed to investigate the role of endoplasmic reticulum Aminopeptidase 2 (ERAP2) in the Pyroptosis of CD4+ T cells in RA and the specific molecular mechanism.

Methods: Peripheral venous blood was collected from human subjects, and CD4+ T cells were isolated and activated to measure the level of Pyroptosis and ERAP2 expression. Pyroptosis levels were assessed using immunofluorescence, flow cytometry, qRT-PCR, and Western blotting. Changes in Pyroptosis levels were observed upon knockdown or overexpression of ERAP2. To detect activated Caspase-1 in tissues, chimeric mice were engrafted with human synovial tissue and reconstituted with human CD4+ T cells. CD4 + T cells were treated with GLI1 antagonists and Smo receptor agonists to detect changes in Pyroptosis levels.

Results: CD4+ T cell levels undergoing Pyroptosis were found to be elevated in the blood and synovium of RA patients. The gene and protein expression of ERAP2 were significantly higher in CD4+ T cells from RA patients. Deletion of ERAP2 suppressed Pyroptosis of these cells, attenuated the activation of Caspase-1 in tissue T cells, and reduced tissue inflammatory responses. Reciprocally, overexpression of ERAP2 triggered inflammasome assembly, activated Caspase-1, and induced Pyroptosis in CD4+ T cells. Mechanistically, ERAP2 inhibits the Hedgehog signaling pathway and upregulates the expression of nucleotide-binding oligomerization segment-like receptor family 3(NLRP3), cleaved Caspase-1, and Gasdermin D to promote Pyroptosis in CD4+ T cells.

Conclusions: Taken together, our results identify a novel mechanism by which ERAP2 regulates RA development and document the effect of the ERAP2/Hedgehog signaling axis on Pyroptosis of CD4+ T cells from RA patients.

Keywords

CD4+ T cells; ERAP2; Hedgehog signaling pathway; Pyroptosis; Rheumatoid arthritis.

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