Dermatophagoides Pteronyssinus 1 (DerP1) May Trigger NLRP3-Mediated Corneal Epithelial Cell Pyroptosis by Elevating Interleukin-33 Expression Levels

Abstract

Purpose

To characterize the in vivo effects of Dermatophagoides pteronyssinus 1 (DerP1) in mice and determine the underlying NLRP3 inflammasome-mediated pyroptosis signaling mechanisms in the human corneal epithelial cells (HCECs).

Methods

DerP1 was used to induce allergic conjunctivitis in C57 mice. HCECs were sensitized with DerP1 in vitro to mimic their condition observed in allergic conjunctivitis in vivo. Transmission electron microscopy was used to evaluate pyroptosis in the HCECs, enzyme-linked immunosorbent assays to assess interleukin (IL)-33, IL-1β and IL-4 levels, flow cytometry to detect the proportion of Th2 cells, MTT assays to assess cell metabolic activity, immunofluorescence to evaluate the effects of DerP1 on functional HCEC phenotypes, and Western blot assays to detect the expression of NOD-like receptor family pyrin domain-containing 3 (NLRP3), gasdermin D (GSDMD), N-terminal fragment of GSDMD (GSDMD-N), pro-caspase-1, cleaved caspase-1, IL-1β, and IL-33. IL-33 expression in the HCECs was knocked down via lentivirus transfection.

Results

In vivo, DerP1 promotes pyroptosis, production of Th2 inflammatory cytokines and IL-33, and NLRP3 activation in mouse corneas. In vitro, pyroptotic bodies were found in the HCECs after sensitization with DerP1. Various concentrations of DerP1 increased the expression levels of NLRP3, GSDMD, GSDMD-N, pro-caspase-1, cleaved caspase-1, and IL-1β in the HCECs, with the largest increase observed after exposure to 20 µM DerP1. In vitro, recombinant human IL-33 mediated the expression of pyroptotic biomarkers in the HCECs, whereas IL-33 silencing diminished 20 µM DerP1-induced increase in their expression levels.

Conclusions

DerP1 induces pyroptosis and allergic conjunctivitis, the expression of Th2 inflammatory cytokines, NLRP3 activation, and IL-33 in mouse corneas in our model. These effects would attribute to its activating NLRP3–GSDMD signaling pathway axis via enhancing IL-33 expression in HCECs.

Keywords:

• Dermatophagoides pteronyssinus 1 (DerP1)
• NLRP3
• corneal epithelial cell
• pyroptosis
• interleukin-33

Acknowledgements

The authors wish to thank Professors Peizeng Yang, Shengping Hou, Hui Peng, and Ning Hu for their assistance.

Author contributions

Shengming Ran conducted experiments, drafted and reviewed the manuscript. Qinxin Shu extracted data. Xu Gao contributed to study design, project conception, supervision, and manuscript review.

Ethics statement

The Animal Care and Use Committee of The First Affiliated Hospital of Chongqing Medical University approved all study protocols (2022-K471). Studies were reviewed and approved by the Ethics Committee of Bishan Hospital of Chongqing Medical University (2020-KY-11).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data of this study is included within the article. The data is available from the first author ([email protected]) upon reasonable request.

Additional information

Funding

This study was supported by grants from the Chongqing Science and Technology Commission Research Program (Chongqing, China) (No. cstc2020jcyj-msxmX1073) and Project of Science and Technology Bureau of Bishan District of Chongqing, China (No. BSKJ2022016).