Duck Tembusu virus induces stronger cellular responses than Japanese encephalitis virus in primary duck neurons and fibroblasts

The Application of Duck Embryonic Fibroblasts CCL-141 as a Cell Model for Adipogenesis

The duck embryo fibroblast cell line CCL-141, which is currently the only commercialized duck cell line, has been underexplored in adipogenesis research. (1) Background: This study establishes an experimental protocol to induce adipogenesis in CCL-141 cells, addressing the importance of understanding gene functions in this process. (2) Methods: Chicken serum, fatty acids, insulin, and all-trans retinoic acid were used to treat CCL-141 cells, with adipogenesis confirmed by Oil Red O staining and gene expression quantification. CRISPR/Cas9 technology was applied to knockout PPARγ, and the resulting adipogenic phenotype was assessed. (3) Results: The treatments promoted adipogenesis, and the knockout of PPARγ validated the cell line's utility for gene function studies. (4) Conclusions: CCL-141 cells are a suitable model for investigating duck adipogenesis, contributing to the understanding of regulatory factors in this biological process.

High-throughput sequencing-based Detection of Japanese encephalitis virus and its effect on micro ribonucleic acid

it was to explore the mechanism of Japanese encephalitis virus (JEV) and micro ribonucleic acid (miRNA) under high-throughput sequencing. 20 experimental mice, with good growth status and no disease infection, were selected. The cells used in the experiment included mouse microglial cell line (BV2), mouse neuroblastoma cell line (NA), and mouse brain endothelial cell line (bEnd.3). JEV titration was performed with JEV-infected cells, ribonucleic acid (RNA) in the cells was extracted, and finally the miRNA high-throughput sequencing data was analyzed. Agarose gel electrophoresis showed that the 28S and 18S electrophoresis bands were bright. Among the miRNAs detected in mouse brain tissues, 2986 were down-regulated and 1251 were up-regulated. Among miRNAs detected in NA cells, 4238 the decreasing expression and 2356 were expressed increasingly. In reducing miRNA expression, 1 multiplicity of infection (MOI) of P3 strain infection was more significant than 0.1 MOI. 10 miRNAs with significantly decreasing expression were miR-466d-3p, miR-381-3p, miR-540-3p, miR-466a-3p, miR-467a-3p, miR-574-5p, miR-199a-5p, miR-467a-5p, miR-674-5p, and miR-376b-3p. These were all obviously down-regulated in JEV-infected BV2, NA, and bEnd.3 neurons. High-throughput sequencing of JEV-infected mouse brain tissues and mouse neuronal cells found that JEV infection led to down-regulation of overall miRNA expression in host cells.

Identification of duck GSDME: Tissue distribution, proteolysis and cellular location

Gasdermin E (GSDME) is a member of the gasdermin family. Cleavage of mammalian GSDME by apoptotic caspases or granzyme proteases liberates the N-terminal effector domain (GSDME-N), which is capable of forming membrane pores and executing inflammation and cell death. Herein, duck GSDME was first cloned with a total length of 1500 bp and encoding 499 amino acids (aa), which is most evolutionally related to the chicken GSDME. The tissue-distribution profiles of GSDME showed that relatively high levels of GSDME mRNA were detected in immune tissues of duckling and adult ducks. Additionally, GSDME mRNA was significantly upregulated in duck primary embryo fibroblasts (DEFs) and duck primary ovary cells after duck Tembusu virus (DTMUV) infection. Intriguingly, when duck caspase-3 was coexpressed, the duck GSDME produced two GSDME-N fragments with molecular weights of 25 kDa and 30 kDa. Furthermore, both GSDME and cleaved GSDME were observed to be located in the cytoplasm by indirect immunofluorescence assay (IFA). Taken together, our research data show that duck GSDME has similar biological characteristics to mammals. These findings highlight the role of duck GSDME in TMUV infection, indicating that cooperation between GSDME and caspase-3 promotes the proteolytic process.

Role of apoptosis in Duck Tembusu virus infection of duckling brains in vivo

The Duck Tembusu virus (DTMUV) is a novel flavivirus that occurs mainly in poultry. DTMUV infection can cause common neurological symptoms in ducklings, but the pathogenesis of DTMUV has not been elucidated yet. In this study, a DTMUV-infected duckling model was constructed to investigate the apoptosis in the duckling brains. After DTMUV infection, apoptotic cells were observed by transmission electron microscopy. It was found that the abundances of apoptosis-related genes and proteins were not obviously changed in the early stage of infection but significantly changed in the middle and late stages of the disease. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay staining results were also consistent with the above phenomena. Interestingly, although apoptosis occurred in the duckling brains infected by DTMUV, some antiapoptotic genes in the brain increased in varying degrees. In conclusion, DTMUV infection could induce apoptosis in ducklings' brains, and the occurrence of apoptosis was accompanied by the virus infection process with certain regularity. This study provides a scientific basis for elucidating the apoptotic mechanism of brain lesions induced by DTMUV infection.