LRRC8A promotes Glaesserella parasuis cytolethal distending toxin-induced p53-dependent apoptosis in NPTr cells

ABSTRACT

Glaesserella parasuis is an early colonizer of the swine upper respiratory tract and can break through the respiratory barrier for further invasion. However, the mechanisms underlying G. parasuis increases epithelial barrier permeability remain unclear. This study demonstrates that G. parasuis cytolethal distending toxin (CDT) induces p53-dependent apoptosis in new-born piglet tracheal (NPTr) cells. Moreover, we report for the first time that leucine-rich repeat-containing protein 8A (LRRC8A), an essential subunit of the volume-regulated anion channel (VRAC), involves in apoptosis of NPTr cells mediated by G. parasuis CDT. Pharmacological inhibition of VRAC with either PPQ-102 or NS3728 largely attenuated CDT-induced apoptosis in NPTr cells. Additionally, experiments with cells knocked down for LRRC8A using small interfering ribonucleic acid (siRNA) or knocked out LRRC8A using CRISPR/Cas9 technology showed a significant reduction in CDT-induced apoptosis. Conversely, re-expression of Sus scrofa LRRC8A in LRRC8A^–/– NPTr cells efficiently complemented the CDT-induced apoptosis. In summary, these findings suggest that LRRC8A is pivotal for G. parasuis CDT-induced apoptosis, providing novel insights into the mechanism of apoptosis caused by CDT.

KEYWORDS:

• Glaesserella parasuis
• cytolethal distending toxin
• cell apoptosis
• p53 signalling
• LRRC8A

Disclosure statement

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

Author contribution

XC designed the experiments, supervised the study, edited the manuscript, and acquired funding. WM designed, performed experiments and drafted the manuscript. ZW, SW, JG and YL edited the manuscript. ZW and SW supplemented the experiments. WM, ZW, YL, HW, JS, and QC analysed the data and contributed reagents, materials, and analysis tools. YX and XX provided overall supervision. All authors have contributed to the manuscript and approved the submitted version.

Data availability statement

The datasets generated for this study are available on request to the corresponding author.

Additional information

Funding

This work was supported by the National Key Research and Development Program Special Project (No. 2022YFD1800902) and the China Agriculture Research System of the MOF and MARA (No. CARS-35).