1. Academic Validation
  2. Porcine Epidemic Diarrhea Virus Infection of Porcine Intestinal Epithelial Cells Causes Mitochondrial DNA Release and the Activation of the NLRP3 Inflammasome to Mediate Interleukin-1β Secretion

Porcine Epidemic Diarrhea Virus Infection of Porcine Intestinal Epithelial Cells Causes Mitochondrial DNA Release and the Activation of the NLRP3 Inflammasome to Mediate Interleukin-1β Secretion

  • Vet Sci. 2024 Dec 12;11(12):643. doi: 10.3390/vetsci11120643.
Di Bao 1 Shushuai Yi 2 Luobing Zhao 3 Han Zhao 1 Jiuyuan Liu 1 Yiming Wei 1 Guixue Hu 1 Xinxin Liu 3
Affiliations

Affiliations

  • 1 College of Veterinary Medicine, Jilin Agricultural University, Changchun 130118, China.
  • 2 College of Veterinary Medicune, Jilin Agricultural Science and Technology University, Jilin 132109, China.
  • 3 Institute of Animal Husbandry and Veterinary Medicine, Jilin Academy of Agricultural Sciences, Kemao Street No. 186, Gongzhuling 136100, China.
Abstract

Porcine epidemic diarrhea virus (PEDV) induces enteritis and diarrhea in piglets. Mitochondrial DNA (mtDNA) contributes to virus-induced inflammatory responses; however, the involvement of inflammasomes in PEDV Infection responses remains unclear. We investigated the mechanism underlying inflammasome-mediated interleukin (IL)-1β secretion during the PEDV Infection of porcine intestinal epithelial (IPEC-J2) cells. IL-1β production and Caspase-1 activity were assessed by quantitative PCR and enzyme-linked immunosorbent assay. NLRP3 inflammasome activation was assessed using immunoprecipitation experiments. Mitochondrial damage was evaluated by analyzing the mitochondrial membrane potential and ATP levels and by the flow cytometry examination of mitochondrial Reactive Oxygen Species (mtROS). Mitochondria and mtDNA localization were observed using immunofluorescence. The inhibition of mtROS and mtDNA production allowed NLRP3 inflammasome and IL-1β expression detection and the evaluation of the pathway underlying NLRP3 inflammasome activation in PEDV-infected IPEC-J2 cells. IPEC-J2 cells upregulated IL-1β upon PEDV Infection, where mature IL-1β secretion depended on Caspase-1 activity, triggered NLRP3 inflammasome expression and assembly, and caused mitochondrial dysfunction, leading to mtDNA release and NLRP3 inflammasome activation, while mtROS contributed to NF-κB pathway activation, enhancing IL-1β secretion. This is the first demonstration of the mechanism underlying mtDNA release and NLRP3 inflammasome activation facilitating IL-1β secretion from PEDV-infected IPEC-J2 cells. These data enhance our understanding of the inflammatory mechanisms triggered by PEDV.

Keywords

IL-1β; IPEC-J2; NLRP3; PEDV; inflammation; mtDNA.

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