Cathepsin B/NLRP3/GSDMD axis-mediated macrophage pyroptosis induces inflammation and fibrosis in systemic sclerosis

Chaofan Liu; Jiaxuan Tang; Shiying Liu; Chen Shen; Xing Zhou; Jinghao Lu; Ming Li; Lubing Zhu

doi:10.1016/j.jdermsci.2022.12.006

Cathepsin B/NLRP3/GSDMD axis-mediated macrophage pyroptosis induces inflammation and fibrosis in systemic sclerosis

J Dermatol Sci. 2022 Dec;108(3):127-137. doi: 10.1016/j.jdermsci.2022.12.006. Epub 2022 Dec 24.

Authors

Chaofan Liu¹, Jiaxuan Tang¹, Shiying Liu¹, Chen Shen², Xing Zhou³, Jinghao Lu⁴, Ming Li¹, Lubing Zhu⁵

Affiliations

¹ Department of Dermatology, Zhongshan Hospital, Fudan University, Shanghai, China.
² Department of Dermatology, Shanghai Skin Disease Hospital, Tongji University School of Medicine, Shanghai, China.
³ Department of Dermatology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China.
⁴ Department of Dermatology, Huashan Hospital, Fudan University, Shanghai, China.
⁵ Department of Dermatology, Zhongshan Hospital, Fudan University, Shanghai, China. Electronic address: zhu.lubing@zs-hospital.sh.cn.

PMID: 36585288
DOI: 10.1016/j.jdermsci.2022.12.006

Abstract

Background: Pyroptosis is a newly discovered type of programmed cell death associated with inflammatory and fibrotic diseases. Macrophages play an important role in inducing early immune inflammation in systemic sclerosis (SSc).

Objective: To investigate the effect of macrophages pyroptosis on fibrosis of SSc.

Methods: Pyroptosis/inflammatory markers in serum and skin of SSc patients were detected. Bleomycin (BLM) was subcutaneously injected to establish SSc mouse model. The levels of pyroptosis markers, dermal thickness and collagen deposition in skin were assessed before and after the administration of pyroptosis inhibitors, including MCC950, Disulfiram and necrosulfonamide (NSA). Human-derived monocyte-macrophage cell line (THP-1) or mouse bone marrow-derived macrophages (BMDMs) were primed with lipopolysaccharide (LPS) and stimulated by silicon dioxide (SiO₂) to induce cell pyroptosis. Fibroblasts from patients with SSc were co-cultured with pyroptotic THP-1 cells, and the collagen production was assessed.

Results: Pyroptotic/inflammatory proteins, including NLRP3, cleaved-Caspase (CASP)1, GSDMD-N terminal and IL-18 were increased in the serum, and ASC aggregation and GSDMD were elevated in macrophages in the skin of SSc patients. SSc mice showed increased pyroptosis markers, dermal thickness and collagen deposition in skins, which were alleviated by MCC950, Disulfiram and NSA. Pyroptosis of THP-1 cells and BMDMs was induced by LPS/SiO₂, and it was reduced by the inhibitors of Cathepsin B, NLRP3, CASP1 and GSDMD. Co-culture with pyroptotic THP-1 cells increased the fibrotic proteins in fibroblasts, which were alleviated by pyroptosis inhibitors.

Conclusions: SSc patients and BLM-induced mouse model presented increased pyroptosis. LPS/SiO₂-induced macrophage pyroptosis promoted fibrosis of SSc through Cathepsin B/NLRP3/GSDMD pathway.

Keywords: Collagen; Macrophage; Pyroptosis; Silicon dioxide; Systemic sclerosis.

MeSH terms

Animals
Caspase 1 / metabolism
Cathepsin B / metabolism
Cathepsin B / pharmacology
Disease Models, Animal
Disulfiram / metabolism
Disulfiram / pharmacology
Fibrosis
Humans
Inflammasomes / metabolism
Inflammation / metabolism
Lipopolysaccharides / pharmacology
Macrophages
Mice
NLR Family, Pyrin Domain-Containing 3 Protein / metabolism
Pyroptosis*
Scleroderma, Systemic* / metabolism
Silicon Dioxide / metabolism
Silicon Dioxide / pharmacology

Substances

NLR Family, Pyrin Domain-Containing 3 Protein
Cathepsin B
Lipopolysaccharides
Disulfiram
Silicon Dioxide
Caspase 1
Inflammasomes
GSDMD protein, human
Nlrp3 protein, mouse