Dual RNA-seq of spleens extracted from channel catfish infected with Aeromonas veronii reveals novel insights into host-pathogen interactions

Mechanism of sturgeon intestinal inflammation induced by Yersinia ruckeri and the effect of florfenicol intervention

The mechanism by which Y. ruckeri infection induces enteritis in Chinese sturgeon remains unclear, and the efficacy of drug prevention and control measures is not only poor but also plagued with numerous issues. We conducted transcriptomic and 16 S rRNA sequencing analyses to examine the differences in the intestinal tract of hybrid sturgeon before and after Y. ruckeri infection and florfenicol intervention. Our findings revealed that Y. ruckeri induced the expression of multiple inflammatory factors, including il1β, il6, and various chemokines, as well as casp3, casp8, and multiple tumor necrosis factor family members, resulting in pathological injury to the body. Additionally, at the phylum level, the relative abundance of Firmicutes and Bacteroidota increased, while the abundance of Plesiomonas and Cetobacterium decreased at the genus level, altering the composition of the intestinal flora. Following florfenicol intervention, the expression of multiple apoptosis and inflammation-related genes was down-regulated, promoting tissue repair. However, the flora became further dysregulated, increasing the risk of infection. In conclusion, our analysis of the transcriptome and intestinal microbial composition demonstrated that Y. ruckeri induces intestinal pathological damage by triggering apoptosis and altering the composition of the intestinal microbiota. Florfenicol intervention can repair pathological damage, but it also exacerbates flora imbalance, leading to a higher risk of infection. These findings help elucidate the molecular mechanism of Y. ruckeri-induced enteritis in sturgeon and evaluate the therapeutic effect of drugs on intestinal inflammation in sturgeon.

Effects of butyl benzyl phthalate on zebrafish (Danio rerio) brain and the underlying molecular mechanisms revealed by transcriptome analysis

Butyl benzyl phthalate (BBP), a widely used class of plasticizers, has caused considerable concerns due to its widespread detection in various environmental media. However, the potential impact of BBP on the brain and its underlying molecular mechanisms remain poorly understood. In this study, adult zebrafish (Danio rerio) were exposed to 0, 5, 50, and 500 μg/L BBP for 28 days. Elevated levels of both reactive oxygen species and 8-hydroxydeoxyguanosine were observed, indicating the occurrence of oxidative stress and DNA damage. Furthermore, exposure to BBP resulted in neurotoxicity, apoptosis, and histopathological damage within the zebrafish brain. Transcriptome analysis further revealed that Gene Ontology terms associated with muscle contraction were specifically expressed in the brain after BBP exposure. In addition, BBP altered the transcriptome profile of the brain, with 293 genes induced and 511 genes repressed. Kyoto Encyclopedia of Genes and Genomes analysis highlighted the adverse effects of BBP on the complement and coagulation cascades and two cardiomyopathy-related pathways. Taken together, our results revealed that BBP resulted in brain oxidative stress, histological damage, and transcriptome alterations. These findings have the potential to offer novel insights into the adverse outcome pathways of key events in the brain.

Effect of Agaricus bisporus Polysaccharides (ABPs) on anti-CCV immune response of channel catfish

Herein, the effects of Agaricus bisporus Polysaccharides (ABPs) on anti-channel catfish virus (CCV) infections to promote their application in channel catfish culture were explored. Transcriptome and metabolome analyses were conducted on the spleen of a CCV-infected channel catfish model fed with or without ABPs. CCV infections upregulated many immune and apoptosis-related genes, such as IL-6, IFN-α3, IFN-γ1, IL-26, Casp3, Casp8, and IL-10, and activated specific immunity mediated by B cells. However, after adding ABPs, the expression of inflammation-related genes decreased in CCV-infected channel catfish, and the inflammatory inhibitors NLRC3 were upregulated. Meanwhile, the expression of apoptosis-related genes was reduced, indicating that ABPs can more rapidly and strongly enhance the immunity of channel catfish to resist viral infection. Moreover, the metabonomic analysis showed that channel catfish had a high energy requirement during CCV infection, and ABPs could enhance the immune function of channel catfish. In conclusion, ABPs can enhance the antiviral ability of channel catfish by enhancing immune response and regulating inflammation. Thus, these findings provided new insights into the antiviral response effects of ABPs, which might support their application in aquaculture.

Effects of diets rich in Agaricus bisporus polysaccharides on the growth, antioxidant, immunity, and resistance to Yersinia ruckeri in channel catfish

To promote the application of Agaricus bisporus polysaccharides (ABPs) in channel catfish (Ictalurus punctatus) culture, we evaluated the effects of ABPs on the growth, immunity, antioxidant, and antibacterial activity of channel catfish. When the amount of ABPs was 250 mg/kg, channel catfish's weight gain and specific growth rates increased significantly while the feed coefficient decreased. We also found that adding ABPs in the feed effectively increased the activities of ACP, MDA, T-SOD, AKP, T-AOC, GSH, and CAT enzymes and immune-related genes such as IL-1β, Hsp70, and IgM in the head kidney of channel catfish. Besides, long-term addition will not cause pathological damage to the head kidney. When the amount of ABPs was over 125 mg/kg, the protection rate of channel catfish was more than 60%. According to the intestinal transcriptome analysis, the addition of ABPs promoted the expression of intestinal immunity genes and growth metabolism-related genes and enriched multiple related KEEG pathways. When challenged by Yersinia ruckeri infection, the immune response of channel catfish fed with ABPs was intenser and quicker. Additionally, the 16S rRNA gene sequencing analysis showed that the composition of the intestinal microbial community of channel catfish treated with ABPs significantly changed, and the abundance of microorganisms beneficial to channel catfish growth, such as Firmicutes and Bacteroidota increased. In conclusion, feeding channel catfish with ABPs promoted growth, enhanced immunity and antioxidant, and improved resistance to bacterial infections. Our current results might promote the use of ABPs in channel catfish and even other aquacultured fish species.