Search Results (6)

Hydropericardium hepatitis syndrome (HHS) is primarily caused by fowl adenovirus serotype 4 (FAdV-4), causing high mortality in chickens. Although vaccination strategies against FAdV-4 have been adopted, HHS still occurs sporadically. Furthermore, no effective drugs are available for controlling FAdV-4 infection. However, type I and III interferon (IFN) are crucial therapeutic agents against viral infection. The following experiments were conducted to investigate the inhibitory effect of chicken IFN against FadV-4. We expressed recombinant chicken type I IFN-α (ChIFN-α) and type III IFN-λ (ChIFN-λ) in Escherichia coli and systemically investigated their antiviral activity against FAdV-4 infection in Leghorn male hepatocellular (LMH) cells. ChIFN-α and ChIFN-λ dose dependently inhibited FAdV-4 replication in LMH cells. Compared with ChIFN-λ, ChIFN-α more significantly inhibited viral genome transcription but less significantly suppressed FAdV-4 release. ChIFN-α- and ChIFN-λ-induced IFN-stimulated gene (ISG) expression, such as PKR, ZAP, IRF7, MX1, Viperin, IFIT5, OASL, and IFI6, in LMH cells; however, ChIFN-α induced a stronger expression level than ChIFN-λ. Thus, our data revealed that ChIFN-α and ChIFN-λ might trigger different ISG expression levels, inhibiting FAdV-4 replication via different steps of the FAdV-4 lifecycle, which furthers the potential applications of IFN antiviral drugs in chickens. Full article

Fowl adenovirus serotype 4 (FAdV-4) is the primary causative agent responsible for the hepatitis-hydropericardium syndrome (HHS) in chickens, leading to considerable economic losses to stakeholders. Although the pathogenesis of FAdV-4 infection has gained attention, the underlying molecular mechanism is still unknown. Here, we showed that the ectopic expression of gga-miR-30c-5p in leghorn male hepatocellular (LMH) cells enhanced apoptosis in FAdV-4-infected LMH cells by directly targeting the myeloid cell leukemia-1 (Mcl-1), facilitating viral replication. On the contrary, the inhibition of endogenous gga-miR-30c-5p markedly suppressed apoptosis and viral replication in LMH cells. Importantly, the overexpression of Mcl-1 inhibited gga-miR-30c-5p or FAdV-4-induced apoptosis in LMH cells, reducing FAdV-4 replication, while the knockdown of Mcl-1 by RNAi enhanced apoptosis in LMH cells. Furthermore, transfection of LMH cells with gga-miR-30c-5p mimics enhanced FAdV-4-induced apoptosis associated with increased cytochrome c release and caspase-3 activation. Thus, gga-miR-30c-5p enhances FAdV-4-induced apoptosis by directly targeting Mcl-1, a cellular anti-apoptotic protein, facilitating FAdV-4 replication in host cells. These findings could help to unravel the mechanism of how a host responds against FAdV-4 infection at an RNA level. Full article

Hepatitis-hydropericardium syndrome (HHS) is caused by fowl adenovirus serotype 4 (FAdV-4) and has resulted in considerable economic losses to the poultry industry globally. FAdV-4 elicits apoptosis in host cells. Long noncoding RNAs (lncRNAs) have emerged as important regulatory RNAs with profound effects on various biological processes, including apoptosis. However, it remains unknown whether lncRNAs participate in FAdV-4-induced apoptosis. In this study, RNA sequencing was applied to determine the transcription of cellular lncRNA in leghorn male hepatocellular (LMH) cells infected with FAdV-4. Cellular RNA transcription analysis demonstrated that FAdV-4 infection elicited 1798 significantly differentially expressed (DE) lncRNAs in infected LMH cells at 24 h post-infection (hpi) compared to mock control infection. In addition, 2873 DE mRNAs were also found. Target prediction and analyses revealed that 775 DE lncRNAs whose 671 target mRNAs were among the DE mRNAs were involved in several signaling pathways, including the AMPK signaling pathway, p53 signaling pathway and insulin signaling pathway. From these 775 DE lncRNAs, we identified 71 DE lncRNAs related to apoptosis based on their target gene functions. Subsequently, lncRNA 54128 was selected from the 71 identified DE lncRNAs, and its role in FAdV-4-induced apoptosis was verified. LncRNA 54128 interference significantly suppressed the rate of apoptosis, which was accompanied by reduced BMP4 transcription levels. To the best of our knowledge, this is the first study to analyze host lncRNA transcription during FAdV-4 infection. Our findings provide a better understanding of host responses to FAdV-4 infection and provide new directions for understanding the potential association between lncRNAs and FAdV-4 pathogenesis. Full article

Hydropericardium-Hepatitis Syndrome (HHS) caused by Fowl Adenovirus Serotype 4 (FAdV4) infection is a severe threat to the poultry industry worldwide, especially in China since 2015. Recent studies show that FAdV4 induces liver injury through apoptosis. However, the underlying molecular mechanism is still unclear. We report here that FAdV4 infection caused apoptosis in Leghorn male hepatocellular (LMH) cells and that PX, a structural protein of FAdV4, acted as a major viral factor inducing apoptosis. Furthermore, the nuclear localization of PX is determined by the R/K regions of PX and required for PX-induced apoptosis. Moreover, alanines 11 and 129 of PX are crucial to PX-induced apoptosis. Inhibition of FAdV4-induced apoptosis by caspase inhibitors retarded viral replication, suggesting that PX serves as a virulence factor for FAdV4 infection, which may further our understandings of the pathogenesis of FAdV4 infection. Full article

Fowl adenovirus serotype 4 (FAdV-4) causes hepatitis-hydropericardium syndrome (HHS), leading to severe economic losses in the poultry industry. Although the pathogenesis of FAdV-4 infection has caused much attention, the underlying molecular mechanisms remain poorly understood. Here, we identified chaperonin containing TCP-1 subunit eta (CCT7) as an interacting partner of the FAdV-4 capsid protein hexon. We found that ectopic expression of CCT7 in leghorn male hepatocellular (LMH) cells enhanced hexon expression in pRK5-flag-hexon transfected cells. On the contrary, knockdown of cellular CCT7 by RNAi markedly reduced hexon expression in FAdV-4-infected cells and suppressed viral replication. These data suggest that CCT7 is required for FAdV-4 replication and may serve as a potential target for controlling FAdV-4 infection. Full article

Long-term exposure and inhalation of odorous compounds from poultry manure can be harmful to farm workers and the surrounding residents as well as animals. The aim of the present study was to determine the cytotoxicity and IC₅₀ values of common odorous compounds such as ammonium, dimethylamine, trimethylamine, butyric acid, phenol, and indole in the chick liver hepatocellular carcinoma cell line LMH (Leghorn Male Hepatoma), in vitro, using MTT (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide) and PrestoBlue cytotoxicity assays. The cells were microscopically examined for any morphological changes post treatment. Dimethylamine exhibited the strongest cytotoxic effect on LMH cells with an IC₅₀ value of 0.06% and 0.04% after an exposure of 24 h and 48 h, respectively. Both ammonium and trimethylamine had comparable cytotoxicity and their IC₅₀ values were 0.08% and 0.04% after 24 h and 48 h, respectively. Of note, indole had the lowest cytotoxicity as the majority of cells were viable even after 72 h exposure. Thus, the IC₅₀ for indole was not calculated. Results achieved from both MTT and PrestoBlue assays were comparable. Moreover, the morphological changes induced by the tested odours in LMH cells resulted in monolayer destruction, cytoplasm vacuolisation, chromatin condensation, and changes in nucleus and cell shape. Our study showed harmful effects of odorous compounds in chick tissues. Full article