The correlated expression of immune and energy metabolism related genes in the response to Salmonella enterica serovar Enteritidis inoculation in chicken

Effects of Dietary Supplementation Using Phytobiotics with Different Functional Properties on Expression of Immunity Genes, Intestinal Histology, Growth, and Meat Productivity of Broiler Chickens

The aim of this study was to investigate the expression of immunity-related genes and morpho-histological features of the intestines, and the growth and meat production of broiler chickens when fed plant extracts with different functional components. Chickens in the control group received a basic diet. The feed in the experimental groups contained plant extracts standardized to various biologically active components such as the extract of common chicory with inulin (INUL), St. John's wort with flavonoids (FLAV), maral root with ecdysterone (ECDS), and extracts of creeping thyme with flavonoids and tannins (FLAV-TANN). The results of this study showed that the application of the studied phytobiotics increased the expression of the pro-inflammatory gene IL8, with the 2-ΔΔCT value ranging from 2.66 to 4.63. In the case of the antimicrobial peptide gene AvBD9, the 2-ΔΔCT value ranged from 1.66 to 8.16, depending on the group. AvBD10 gene expression increased (2-ΔΔCT = 2.19) when the chickens were fed the chicory extract and decreased when thyme extract was used (2-ΔΔCT = 0.33). The study also found that using biologically active components in the diets of broiler chickens was accompanied by a significant decrease in the height of epithelial cells in the cecum mucous membrane in the INUL group (61.3%, p ≤ 0.001), FLAV group (60.0%, p ≤ 0.001), ECDS group (48.2%, p ≤ 0.001), and FLAV + TANN group (67.6%, p ≤ 0.001). It also caused a reduction in the depth of crypts in the INUL (38.4%, p ≤ 0.001), FLAV (32.3%, p ≤ 0.001), ECDS (50.9%, p ≤ 0.001), and FLAV + TANN (53.4%, p ≤ 0.001) groups. The use of all extracts, except creeping thyme, caused changes in the size of muscular elements in the intestinal walls; thus, the thickness of the muscular layer increased 1.5-2.0 times under the influence of flavonoids in St. John's wort and of inulin in chicory, to 430.99 and 579.87 μm, respectively (p ≤ 0.001), and decreased 1.9 times under the influence of ecdysterone in maral root to 151.59 μm (p ≤ 0.001). The use of phytobiotics increased feed consumption and stock safety, leading to an increase of 4.1-7.5% in the live weights of broiler chickens at the end of the rearing period, thus contributing to the higher slaughter quality of poultry; in particular, the weights of breast muscles in cockerels in the INUL group increased by 16.9% (p ≤ 0.05), while the weights in the ECDS and FLAV + TANN groups increased by 18.1% (p ≤ 0.05) and 23.1% (p ≤ 0.01), respectively. Thus, the use of the studied phytobiotics in the broiler chicken diet increases meat production and activates immunity, which indicates the possibility of replacing antibacterial drugs with natural nutraceuticals.

Temporal transcriptome profiling in the response to Salmonella enterica serovar enteritidis infection in chicken cecum

Salmonella enterica serovar Enteritidis (S. Enteritidis) is a common zoonotic pathogen that not only causes gastroenteritis or death of livestock and poultry but also poses a serious threat to human health, causing severe economic losses to the poultry industry and society. Herein, RNA-sequencing (RNA-seq) was used to analyze the transcriptome variation of chicken cecum at four different time points (1, 3, 7, and 14 days) following S. Enteritidis infection. There were 529, 1477, 476, and 432 differentially expressed genes (DEGs) in the cecum at four different days post-infection (dpi), respectively. The DEGs were significantly enriched in various immune-related pathways on 3 dpi and 7 dpi, such as cytokine-cytokine-receptor interaction and Toll-like receptor signaling pathway. DEGs were significantly enriched in several metabolic pathways on 14 dpi. Gene ontology (GO) enrichment of DEGs showed that up-regulated genes were significantly enriched in immune-related terms on 3 and 7 dpi. On 14 dpi, up-regulated genes were mainly enriched in the signaling-related terms, while the down-regulated genes were primarily enriched in the metabolic-related terms. Based on weighted gene co-expression network analysis (WGCNA), the key modules related to energy, non-coding processes, immunity, and development-related functions were identified at 1, 3, 7, and 14 dpi, respectively, and 5, 8, 6, and 5 hub genes were screened out, respectively. This study demonstrated that the chicken cecal transcriptome regulation responding to S. Enteritidis infection is time-dependent. The regulation of S. Enteritidis infection in chickens is coordinated by multiple systems, mainly involving immunity, metabolism, and signal transduction. Both 3 and 7 dpi are key time points for immune response. As the infection progresses, metabolism-related pathways were increasingly identified. This change reflects the dynamic adjustment between immune response and metabolism in Jining Bairi chickens following S. Enteritidis infection. These results suggested that starting from 3 dpi, the chickens gradually transition from an immune response triggered by S. Enteritidis infection to a state where they adapt to the infection by modulating their metabolism.

Therapeutic effects and mechanisms of berberine on enteritis caused by Salmonella in poultry

The present study aimed to investigate the therapeutic effects of berberine (BBR) on Salmonella enteritis in broiler chickens and to elucidate its mechanisms of action preliminarily. Blood samples were collected from 21- to 35-day-old Sanhuang male chicks to measure immune and biochemical indicators and to calculate the organ coefficients for the liver, spleen, bursa of Fabricius, and thymus. The caecal microbiota was analysed through 16S ribosomal RNA (rRNA) gene sequencing, and transcriptome sequencing was conducted. Compared with the positive control group (S), the berberine-treated group (BS) presented increased serum immunoglobulin M (IgM) levels, serum IgG levels, and total antioxidant capacity; berberine ameliorated the increase in the thymus index caused by Salmonella administration. The addition of berberine to the diet increased the abundance of beneficial bacterial genera, including Bacteroides and Lactobacillus. It also decreased the abundance of harmful bacterial genera, including Faecalibacterium and Streptococcus. Transcriptome analysis revealed that gene expression in the S and BS groups was associated with T cell selection and B cell receptor signalling pathways, which are enriched primarily in multiple immune-related signalling pathways, including the B cell receptor signalling pathway, NF-κ B signalling pathway, intestinal immune network for IgA production, asthma, and African trypanosomiasis. The significantly expressed genes included ATAD5, ERP29, MGST2, PIK3CA, and HSP90AA1. The present study demonstrated that berberine has a good therapeutic effect on Salmonella infection in chicks, as it inhibits the occurrence and development of Salmonella-induced intestinal inflammation by regulating the balance of the gut microbiota and the expression of related genes, including ATAD5, ERP29, MGST2, PIK3CA, and HSP90AA1.

Genome-wide detection of positive and balancing signatures of selection shared by four domesticated rainbow trout populations (Oncorhynchus mykiss)

BACKGROUND

Evolutionary processes leave footprints along the genome over time. Highly homozygous regions may correspond to positive selection of favorable alleles, while maintenance of heterozygous regions may be due to balancing selection phenomena. We analyzed data from 176 fish from four disconnected domestic rainbow trout populations that were genotyped using a high-density Axiom Trout genotyping 665K single nucleotide polymorphism array, including 20 from the US and 156 from three French lines. Using methods based on runs of homozygosity and extended haplotype homozygosity, we detected signatures of selection in these four populations.

RESULTS

Nine genomic regions that included 253 genes were identified as being under positive selection in all four populations Most were located on chromosome 2 but also on chromosomes 12, 15, 16, and 20. In addition, four heterozygous regions that contain 29 genes that are putatively under balancing selection were also shared by the four populations. These were located on chromosomes 10, 13, and 19. Regardless of the homozygous or heterozygous nature of the regions, in each region, we detected several genes that are highly conserved among vertebrates due to their critical roles in cellular and nuclear organization, embryonic development, or immunity. We identified new candidate genes involved in rainbow trout fitness, as well as 17 genes that were previously identified to be under positive selection, 10 of which in other fishes (auts2, atp1b3, zp4, znf135, igf-1α, brd2, col9a2, mrap2, pbx1, and emilin-3).

CONCLUSIONS

Using material from disconnected populations of different origins allowed us to draw a genome-wide map of signatures of positive selection that are shared between these rainbow trout populations, and to identify several regions that are putatively under balancing selection. These results provide a valuable resource for future investigations of the dynamics of genetic diversity and genome evolution during domestication.

Role of ATP5G3 in sodium nitroprusside-induced cell death in cervical carcinoma cells

We identified a gene, subunit C3 (ATP5G3) of mitochondrial ATP synthase, that displayed changes in gene expression under oxidative stress. We examined the role of ATP5G3 and its molecular mechanisms in sodium nitroprusside (SNP)-induced cell death using ATP5G3 small interfering RNA (siATP5G3)-transfected HeLa cells. A significant increase in cytotoxicity was observed in the transfected cells treated with SNP, which suggests a protective role of ATP5G3 in SNP-induced cytotoxicity in the cells. The transfected cells treated with photodegraded SNP showed equal cytotoxicity to SNP, and pretreatment with deferoxamine (DFO) completely inhibited this cytotoxicity. Further, cytotoxicity was significantly inhibited by pretreatment with a p38 inhibitor and was accentuated by the p38 activator in cells. Pretreatment with the Bcl-xL inhibitor also significantly accentuated cytotoxicity. The increase in p38 phosphorylation was significantly higher in siATP5G3-transfected cells treated with SNP in immunoblotting, which was inhibited by pretreatment with DFO. The increase in cytotoxicity with siATP5G3 transfection was completely blocked by cotransfection with sip38, and the blocking effect disappeared by cotransfection with additional siBcl-xL, which suggests that the protective role of ATP5G3 is mediated by Bcl-xL via the inhibition of p38 activity. Cytotoxicity was completely blocked by the cotransfection of siATP5G3 with siBax. No change in apoptotic parameters was observed during cytotoxicity. However, pretreatment with lysosomal inhibitors significantly inhibited cytotoxicity and increased p62 protein levels. These findings suggest that ATP5G3 plays a protective role in autophagic cell death/lysosome-associated cell death induced by SNP via the sequential signaling of ROS/p38/Bcl-xL/Bax in HeLa cells.

Meta-Analysis and Systematic Review of the Thermal Stress Response: Gallus gallus domesticus Show Low Immune Responses During Heat Stress

Heat stress, which affects broiler growth performance and immunity, is a major concern in the poultry industry. This meta-analysis aimed to demonstrate the significant effect of heat stress on broiler mass gain and immunoglobulin levels, which regulates the mortality rate of broilers. A total of 2,585 studies were downloaded from PubMed, Web of Science, and Google Scholar from January 1, 2015, to September 1, 2021. Eventually, 28 studies were selected based on specific criteria. The results for body mass gain, total mass of immune organs (thymus, spleen, and bursa of Fabricius), immunoglobulin (IgA, IgG, and IgM) levels, and mortality rate were analyzed using odds ratio or the random-effects model (REM) at a confidence interval (CI) of 95%. Compared to the control, heat stress significantly decreased body mass gain (10 trials: REM = 1.35, 95% CI: 1.21, 1.50). Compared to that in the control, heat stress significantly increased immunoglobulin levels: IgA (7 trials: REM = 1.69, 95% CI: 0.90, 3.16), IgG (6 trials: REM = 1.24, 95% CI: 0.85, 1.81), IgM (8 trials: REM = 0.69, 95% CI: 0.44, 1.08), and heat stress also increased the broiler mortality rate (6 trials: REM = 0.06, 95% CI: 0.01, 0.27). However, there were no significant changes in the immune organs between the control and heat-stressed groups. In conclusion, heat stress remarkably alters the mass gain and immunoglobulin levels of broilers, which may be a cause of the high mortality rate.

Chicken cecal DNA methylome alteration in the response to Salmonella enterica serovar Enteritidis inoculation

BACKGROUND

Salmonella enterica serovar Enteritidis (SE) is one of the pathogenic bacteria, which affects poultry production and poses a severe threat to public health. Chicken meat and eggs are the main sources of human salmonellosis. DNA methylation is involved in regulatory processes including gene expression, chromatin structure and genomic imprinting. To understand the methylation regulation in the response to SE inoculation in chicken, the genome-wide DNA methylation profile following SE inoculation was analyzed through whole-genome bisulfite sequencing in the current study.

RESULTS

There were 185,362,463 clean reads and 126,098,724 unique reads in the control group, and 180,530,750 clean reads and 126,782,896 unique reads in the inoculated group. The methylation density in the gene body was higher than that in the upstream and downstream regions of the gene. There were 8946 differentially methylated genes (3639 hypo-methylated genes, 5307 hyper-methylated genes) obtained between inoculated and control groups. Methylated genes were mainly enriched in immune-related Gene Ontology (GO) terms and metabolic process terms. Cytokine-cytokine receptor interaction, TGF-beta signaling pathway, FoxO signaling pathway, Wnt signaling pathway and several metabolism-related pathways were significantly enriched. The density of differentially methylated cytosines in miRNAs was the highest. HOX genes were widely methylated.

CONCLUSIONS

The genome-wide DNA methylation profile in the response to SE inoculation in chicken was analyzed. SE inoculation promoted the DNA methylation in the chicken cecum and caused methylation alteration in immune- and metabolic- related genes. Wnt signal pathway, miRNAs and HOX gene family may play crucial roles in the methylation regulation of SE inoculation in chicken. The findings herein will deepen the understanding of epigenetic regulation in the response to SE inoculation in chicken.