Untargeted and targeted metabolomics profiling reveals the underlying pathogenesis and abnormal arachidonic acid metabolism in laying hens with fatty liver hemorrhagic syndrome

Liver Haemorrhagic Syndrome in Broilers: Its Effect on Serum Parameters, Antioxidant Capacity, Liver Enzymes and Fatty Acid Profile of Liver

This study sought to evaluate the occurrence of various degrees of liver haemorrhagic syndrome (LHS) in broilers subjected to commercial rearing conditions. The objective was to investigate the influence of lesion scores on various biochemical parameters. The prevalence of liver lesions graded from 0 to 5 was 12%, 31%, 33%, 15%, 6% and 3%, respectively. The crude protein content decreased, whereas the crude fat content increased in Scores 4 and 5 (p < 0.05). The observed increase in thiobarbituric acid reactive substances (TBARSs), carbonyl and sulphydryl levels in Score 5 (82.8%, 43.3% and 74.8%, respectively) suggests that this score may be more susceptible to oxidation compared to livers with no LHS incidence (p < 0.01). A reduction in total protein in Scores 4 and 5, a decline in albumin in Score 5, an elevation in uric acid and gamma-glutamyl transferase (GGT) in Scores 4 and 5 as well as a rise in cholesterol and alanine transaminase (ALT) in Score 5 were noted (p < 0.05). Furthermore, there was an increase in aspartate transferase (AST) levels in 3, 4 and 5 (p < 0.01). A comparison of the antioxidant data indicated a significant enhancement in the levels of superoxide dismutase (SOD), glutathione peroxidase (GSH PX) and total antioxidants in Scores 1-3, compared to the control group. The lowest levels of SOD, GSH PX and total antioxidants were observed in livers scored 4 and 5 (p < 0.01). Besides, an increase in total saturated fatty acids and a decrease in total monounsaturated fatty acid (MUFA), n-6, n-3 and polyunsaturated fatty acid (PUFA) levels were observed in livers scored 4 and 5 when compared to the other groups (p < 0.05). In conclusion, this study has demonstrated that elevated levels of LHS scores are associated with a detrimental impact on the physicochemical and oxidative quality of livers and blood serum.

Impact of bacteroides uniformis on fatty liver hemorrhagic syndrome in dawu golden phoenix laying hens: modulation of gut microbiota and arachidonic acid metabolism

This study explored the impact of Bacteroides uniformis (B. uniformis) on fatty liver hemorrhagic syndrome (FLHS) induced by a high-energy and low-protein (HELP) diet in laying hens, mainly focusing on hepatic lipid metabolism, gut microbiota, and arachidonic acid (AA) metabolism. A total of 120 Dawu Golden Phoenix laying hens (210-day-old) were randomly divided into four groups. The control group (CON) was fed a standard diet and received a daily gavage of PBS, while the other groups were fed with a HELP diet to induce FLHS and received a daily gavage of PBS (MOD), 1 × 109 CFU/ml B. uniformis (BUL), and 1 × 1011 CFU/ml B. uniformis (BUH) for 70 days. All hens were administered 1 ml daily by gavage. Each group had 6 replications with 5 hens per replication. The results showed that B. uniformis increased the egg production rate and feed conversion ratio and decreased body weight, liver index, and abdominal fat rate (p < 0.05). B. uniformis treatment reduced liver lipid accumulation by reducing the levels of Triglyceride (TG), Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), alanine transaminases (ALT), and aspartate transaminases (AST) in serum and significantly elevated high-density lipoprotein cholesterol (HDL-C) (p < 0.05). The results indicated that B. uniformis altered the gut microbiota. Specifically, the abundance of Bacteroides was higher, and the relative abundances of Treponema, Helicobacter, and Spirochaetota were lower than those of the MOD group (p < 0.05). Moreover, targeted metabolomic analysis showed that supplementation of B. uniformis significantly elevated 6-keto-PGF1α and AA levels, along with significantly reduced levels of thromboxane B2 (TXB2), leukotriene D4 (LTD4), 8-isoprostaglandin F2α (8-iso-PGF2α), 12S-hydroxyeicosatetraenoic acid (12S-HETE), 15S-hydroxyeicosatetraenoic acid (15S-HETE), 9-S-hydroxy-octadecadienoic acid (9S-HODE), and 13-S-hydroxy-octadecadienoic acid (13S-HODE) (p < 0.05). In conclusion, the oral intake of B. uniformis can improve liver function, gut microbiota, and AA metabolism, thereby helping to ameliorate FLHS in Dawu Golden Phoenix laying hens.

Multiomics Reveal the Effects and Regulatory Mechanism of Naringin on Metabolic Dysfunction-Associated Fatty Liver Disease of Laying Hens

This study aimed to utilize aged laying hens as a model to investigate the effects of naringin on the occurrence and progression of metabolic dysfunction-associated fatty liver disease (MAFLD), along with its underlying regulatory mechanisms. A total of 288 aged laying hens, 50-week-old, were divided into four groups: a normal diet (ND) group, and three naringin groups receiving 200 mg/kg (N1), 400 mg/kg (N2), and 600 mg/kg (N3). The experiment lasted for 10 weeks, after which serum, liver, and cecal contents were collected from the hens. Results indicated that dietary naringin supplementation reduced hepatic lipid deposition, lowered blood lipid levels, improved antioxidant capacity, and promoted estradiol secretion. Additionally, 16S rDNA analysis revealed that naringin enhanced microbial diversity in the cecum and regulated the abundance of gut microbes associated with fatty liver. Untargeted metabolomics of blood demonstrated that naringin decreased the concentration of glycerophospholipid and sterol lipid metabolites while increasing levels of pantothenic acids and amino acid metabolites. Furthermore, liver transcriptome analysis indicated that naringin interfered with fatty acid synthesis and transport processes while enhancing fatty acid oxidation. Dietary naringin supplementation can mitigate the occurrence of MAFLD by regulating the gut-liver axis and estrogen signaling, particularly in postmenopausal women.

Caffeic acid and chlorogenic acid mediate the ADPN-AMPK-PPARα pathway to improve fatty liver and production performance in laying hens

BACKGROUND

Caffeic acid (CA) and its derivative, chlorogenic acid (CGA), have shown promise in preventing and alleviating fatty liver disease. CA, compared to CGA, has much lower production costs and higher bioavailability, making it a potentially superior feed additive. However, the efficacy, mechanistic differences, and comparative impacts of CA and CGA on fatty liver disease in laying hens remain unclear. This study aimed to evaluate and compare the effects of CA and CGA on production performance, egg quality, and fatty liver disease in laying hens.

RESULTS

A total of 1,440 61-week-old Hyline Brown laying hens were randomly divided into 8 groups and fed diets supplemented with basal diet, 25, 50, 100 and 200 mg/kg of CA, and 100, 200 and 400 mg/kg of CGA (CON, CA25, CA50, CA100, CA200, CGA100, CGA200 and CGA400, respectively) for 12 weeks. Both CA and CGA improved production performance and egg quality, while reducing markers of hepatic damage and lipid accumulation. CA and CGA significantly decreased TG, TC, and LDL-C levels and increased T-SOD activity. Transcriptomic and proteomic analyses revealed that CA and CGA reduced hepatic lipid accumulation through downregulation of lipid biosynthesis-related genes (ACLY, ACACA, FASN, and SCD1) and enhanced lipid transport and oxidation genes (FABPs, CD36, CPT1A, ACOX1, and SCP2). Of note, low-dose CA25 exhibited equivalent efficacy to the higher dose CGA100 group in alleviating fatty liver conditions. Mechanistically, CA and CGA alleviated lipid accumulation via activation of the ADPN-AMPK-PPARα signaling pathway.

CONCLUSIONS

This study demonstrates that dietary CA and CGA effectively improve laying performance, egg quality, and hepatic lipid metabolism in laying hens, with CA potentially being more economical and efficient. Transcriptomic and proteomic evidence highlight shared mechanisms between CA25 and CGA100. These findings provide a foundation for CA and CGA as therapeutic agents for fatty liver disease and related metabolic diseases in hens, and also offer insights into the targeted modification of CGA (including the isomer of CGA) into CA, thereby providing novel strategies for the efficient utilization of CGA.

Effects of induced molting on lipid accumulation in liver of aged laying hens

As the age of laying increases, the metabolic capacity of the liver decreases, leading to excessive lipid accumulation, which seriously affects the laying performance of laying hens. Induced molting (IM) can rejuvenate the reproductive system of older laying hens, allowing them to enter a new laying cycle. However, it remains unclear whether induced molting can enhance lipid accumulation in the liver of aged laying hens and what the underlying mechanism might be. In this study, fasting-induced molting was performed on 70-week-old Hy-line brown laying hens, and the resulting metabolic changes were analyzed using non-targeted metabolomics. Serum lipid levels, liver oxidative stress, and inflammation were measured using kits, while autophagy and lipid metabolism-related factors were assessed through immunofluorescence and western blotting. The results showed that IM could promote hepatic lipid deposition in aged laying hens, reduce hepatic steatosis and injury, lower the blood lipid level, improve hepatic antioxidant capacity and increase egg production rate. During the fasting period, the hepatic autophagic system was activated in laying hens and the level of hepatic autophagy increased. Additionally, AMPK phosphorylation levels increased, while the expression of fatty acid synthesis genes SREBP-1C, ACC, and FASN decreased (P < 0.01). The expression of PPARα, PGC 1α and CPT1A, which are associated with fatty acid oxidation, was upregulated (P < 0.01). In conclusion, IM enhanced lipid metabolism, increased liver autophagy, and improved liver function in aged laying hens.

Immunomodulatory and anti-inflammatory potential of botanicals bioactive product (PHYTO AX'CELL™) for an improvement of the well-being of laying hens at the peak of production

This study was designed to assess the effectiveness of an authorized commercial standardized mixture of Artepillin-C, methyl-salicylates, flavonoids and curcuminoids (PHYTO AX'CELL™) provided intermittently during 8 weeks (wk) of trial to laying hens raised in enriched cages during the peak of the production, in the reduction of inflammation status, improving the immune response, and egg quality. In this study, 764 Lohmann LSL-White hens on the first day (d) of the 26th wk of age (T0), were randomly assigned to 2 replicated experimental groups, control and treated (n=382 each). The treatment was supplied in drinking water, as follows: 26th to 27th wk (T1, 14 d) first treatment administration at a dose of 1 mL/L (0.5 mL/L only the first d of the treatment); 28th to the 31st wk (T2, 4 wk of withdrawal period); 32nd to 33rd wk (T3, 14 d) second treatment at a dose of 1 mL/L, until the end of the trial (T4). At T0, mid-T3 and T4, 13 hens per group were sampled for serum biochemical analyses (metabolic profile, H/L ratio) and weighed, and 60 eggs per group were analyzed for quality parameters. At T4, 13 hens per group were sacrificed for histological investigations and gut IgA quantification. The treatment reduced the mortality rate in the treated group (0.00%) compared to the control (2.61%). An improvement in intestinal IgA production and immune reactivity in the treated hens was observed with a significant fluctuating trend of the heterophil, lymphocyte and their ratio (P < 0.05). The egg quality was improved by the treatment, with positive effects in the Haugh unit, shell weight and thickness (P < 0.05). A T4, significant reduction in duodenal and rectal pH was observed in the treated group (P < 0.05), without intestinal inflammation score changes, body weight, serum biochemistry, interleukin levels, and infectious bronchitis virus titers (P > 0.05). From the results, PHYTO AX'CELL™ improved the well-being and physical condition of laying hens raised in cages, modulating the immune system with a positive production of intestinal IgA, and egg quality parameters important for commercial purposes.

Improving fatty liver hemorrhagic syndrome in laying hens through gut microbiota and oxylipin metabolism by Bacteroides fragilis: A potential involvement of arachidonic acid

Bacteroides fragilis (B. fragilis), a crucial commensal bacterium within the gut, has shown connections with hepatic lipid metabolism and inflammation regulation. Nonetheless, the role of B. fragilis in the progression of fatty liver hemorrhagic syndrome (FLHS) remains unknown. This study aims to explore the ameliorative effects of B. fragilis on FLHS in laying hens, as well as its underlying mechanisms. This is the first study to employ a chicken FLHS model, combining microbiomics and oxylipin metabolomics to investigate the mechanism of action of intestinal symbiotic bacteria. Exp. 1: 40 laying hens at 25 weeks old were randomly divided into five treatment groups (eight replicates per group and one hen per replicate), including the control group (basal diet), the high-energy and low-protein (HELP) group, and the HELP group with three different levels (108, 109, and 1010 CFU) of B. fragilis. Exp. 2: 18 chickens at 25 weeks old were randomly divided into three treatment groups (six replicates per group and one hen per replicate) including the control group (basal diet), the model group (HELP diet), and the arachidonic acid (AA) group (HELP diet with 0.3% AA). The experiment period of Exp. 1 and Exp. 2 were 8 weeks. B. fragilis significantly improved body weight of seventh week (P = 0.006), liver lipid degeneration, blood lipid levels (triglycerides, cholesterol, and low-density lipoprotein cholesterol; P < 0.05), and liver function (alanine aminotransferase and aminotransferase; P < 0.05) in laying hens. B. fragilis downregulated the expression of lipid synthesis-related genes fatty acid synthase, acetyl-CoA carboxylase, and liver X receptor α, and inflammation-related genes tumor necrosis factor α, interleukin (IL)-1β, IL-6, and IL-8 in the liver of FLHS-affected hens (P < 0.05), while upregulating the expression of lipid oxidation-related genes carnitine palmitoyl transferase-1, peroxisome proliferator activated receptor (PPAR) α, and PPARγ (P < 0.05). The in-depth analysis indicated alterations in oxylipin pathways triggered by B. fragilis, as evidenced by changes in the expression of pivotal genes arachidonate 15-lipoxygenase, arachidonate 5-lipoxygenase (P < 0.05), subsequently causing modifications in relevant metabolites. This included a decrease in pro-inflammatory substances such as 15-oxoETE (P = 0.004), accompanied by an increase in AA (P = 0.008). B. fragilis regulated the homeostasis of intestinal flora by increasing the abundance of Bacteroides and decreasing the abundance of Succinatimonas and Faecalicoccus (P < 0.05). The integrated analysis revealed a robust positive correlation between Bacteroides abundance and AA levels (P = 0.007). This relationship was corroborated through in vitro experiments. Subsequently, the beneficial effect of AA in mitigating FLHS was confirmed in laying hens with FLHS, further supported by reverse transcription-polymerase chain reaction analysis demonstrating gene expression patterns akin to B. fragilis intervention. This study demonstrated that B. fragilis exerts an anti-FLHS effect through modulation of oxylipin metabolism and gut microbiota stability, with a pivotal role played by AA.

Goose Deoxycholic Acid Ameliorates Liver Injury in Laying Hens with Fatty Liver Hemorrhage Syndrome by Inhibiting the Inflammatory Response

Fatty liver hemorrhagic syndrome (FLHS) in laying hens is a nutritional and metabolic disease involving liver enlargement, hepatic steatosis, and hepatic hemorrhage as the primary symptoms. The syndrome is prone to occur during the peak laying period of laying hens, which has resulted in significant economic losses in the laying hen breeding industry; however, the specific pathogenesis of FLHS remains unclear. Our group and previous studies have shown that bile acid levels are significantly decreased during the development of fatty liver and that targeted activation of bile acid-related signaling pathways is beneficial for preventing and treating fatty liver. In this study, we generated a FLHS laying hen model by feeding hens a high-energy, low-protein diet, with goose deoxycholic acid (CDCA) given as an intervention. HE staining, fluorescence quantitative PCR, and ELISA were used to evaluate the effects of CDCA on pathological changes and inflammatory responses in the liver. The results showed that hepatic hemorrhage in FLHS laying hens was reduced after CDCA treatment. Furthermore, fat vacuoles and transaminase levels decreased significantly. In addition, expression levels of M1-type macrophage markers and polarization products were significantly reduced, and the expression of pro-inflammatory regulatory factors related to the JAK-STAT signaling pathway, LPS-TLR4-Myd88-NF-kB signaling pathway, and NLRP3 inflammasomes decreased significantly as well. Expression levels of M2-type macrophage markers and polarization products increased significantly, as did the expression of anti-inflammatory regulators related to the JAK-STAT signaling pathway. These results suggest that CDCA ameliorates liver injury in laying hens with FLHS by inhibiting macrophage M1-type polarization and the resulting pro-inflammatory response, thereby promoting M2-type macrophage polarization and an anti-inflammatory response.

Advance in the application of metabolomics technology in poultry

Metabolomics is a science that takes small molecular metabolites in organisms as the research object and determines the dynamic changes of metabolites at the overall level through a variety of modern analytical techniques. At present, metabolomics technology has been widely used in biological significance interpretation, food safety and quality, breeding, disease diagnosis, functional compound identification, and other fields. Its application in poultry science has also become the focus of widespread attention. With the sustainable development of analytical techniques, metabolomics has great potential in the application of poultry science. In this paper, the research progress of metabolomics in poultry growth and development, genetics and breeding, egg quality, meat quality, and disease is reviewed and concluded, which is expected to provide scientific ideas for the research of metabolomics in poultry.

Dioscin improves fatty liver hemorrhagic syndrome by promoting ERα-AMPK mediated mitophagy in laying hens

BACKGROUND

Mitochondria play a crucial role in upholding metabolic homeostasis. Mitochondrial damage closely associated with the pathogenesis of fatty liver hemorrhagic syndrome (FLHS), while mitophagy being among the most effective methods for eliminating the damaged mitochondria. Dioscin, a natural extract, can activate autophagy; however, its effects on FLHS regarding mitophagy regulation remain unelucidated.

PURPOSE

We explored the impact of dioscin on FLHS induced by a high-energy and low-protein (HELP) diet in laying hens, mainly focused the protective effects of dioscin on mitochondrial injury.

METHOD

To investigate the impact of dioscin on fatty liver syndrome in laying hens, we first induced the condition by feeding them a high-energy and low-protein diet. Then, we assessed lipid metabolism-related markers using oil red staining and a commercial detection kit. In addition, the role of dioscin on fatty liver syndrome in laying hens was confirmed by assessing the activation of hepatocyte fat deposition and hepatocyte apoptosis; and the mechanism of dioscin in FLHS was investigated through LMH cell experiment in vitro. Furthermore, CETSA and molecular docking were conducted for additional confirmation.

RESULT

The results showed that dioscin alleviated mitochondrial damage, relieved the excessive deposition of hepatic lipid droplets and oxidative stress induced by HELP diet in laying hens. Furthermore, dioscin regulated the mitophagy by activating the estrogen receptor α (ERα)/adenosine 5'-monophosphate-activated protein kinase (AMPK) signaling pathway, thus mitigating mitochondria injury and apoptosis in hepatocytes. In addition, we found that dioscin promoted the translocation of nuclear transcription factor into nucleus by activating ERα-AMPK signaling, facilitating autophagic flux in the liver of laying hens and LMH cells. Furthermore, cells pretreated with the lysosomal acidification inhibitor bafilomycin A1 blocked the inhibitory effect of dioscin on the apoptosis induced by palmitic acid (PA)-stimulation in LMH cells, suggesting that dioscin reduces PA-induced apoptosis by activating mitophagy. Moreover, dioscin-induced lysosomal acidification and mitochondrial biogenesis were reversed in PA-induced LMH cells pretreated with ERα-specific inhibitor methylpiperidino pyrazole.

CONCLUSION

This study firstly demonstrated that dioscin alleviates fatty liver syndrome induced by HELP diet in laying hens. The findings from this study illustrated that dioscin plays a significant role in reducing mitochondrial damage and apoptosis, and these beneficial effects mainly achieve through promotion of ERα-AMPK signaling, which mediates autophagy within the liver of laying hens fed a HELP-diets. These findings provide a theoretical basis for considering dioscin as a possible treatment option for mitigating FLHS in egg-laying hens.

Glucose Metabolism-Modifying Natural Materials for Potential Feed Additive Development

Glucose, a primary energy source derived from animals' feed ration, is crucial for their growth, production performance, and health. However, challenges such as metabolic stress, oxidative stress, inflammation, and gut microbiota disruption during animal production practices can potentially impair animal glucose metabolism pathways. Phytochemicals, probiotics, prebiotics, and trace minerals are known to change the molecular pathway of insulin-dependent glucose metabolism and improve glucose uptake in rodent and cell models. These compounds, commonly used as animal feed additives, have been well studied for their ability to promote various aspects of growth and health. However, their specific effects on glucose uptake modulation have not been thoroughly explored. This article focuses on glucose metabolism is on discovering alternative non-pharmacological treatments for diabetes in humans, which could have significant implications for developing feed additives that enhance animal performance by promoting insulin-dependent glucose metabolism. This article also aims to provide information about natural materials that impact glucose uptake and to explore their potential use as non-antibiotic feed additives to promote animal health and production. Further exploration of this topic and the materials involved could provide a basis for new product development and innovation in animal nutrition.

Epigenetic regulation of H3K27me3 in laying hens with fatty liver hemorrhagic syndrome induced by high-energy and low-protein diets

BACKGROUND

Fatty liver hemorrhagic syndrome (FLHS) in the modern poultry industry is primarily caused by nutrition. Despite encouraging progress on FLHS, the mechanism through which nutrition influences susceptibility to FLHS is still lacking in terms of epigenetics.

RESULTS

In this study, we analyzed the genome-wide patterns of trimethylated lysine residue 27 of histone H3 (H3K27me3) enrichment by chromatin immunoprecipitation-sequencing (ChIP-seq), and examined its association with transcriptomes in healthy and FLHS hens. The study results indicated that H3K27me3 levels were increased in the FLHS hens on a genome-wide scale. Additionally, H3K27me3 was found to occupy the entire gene and the distant intergenic region, which may function as silencer-like regulatory elements. The analysis of transcription factor (TF) motifs in hypermethylated peaks has demonstrated that 23 TFs are involved in the regulation of liver metabolism and development. Transcriptomic analysis indicated that differentially expressed genes (DEGs) were enriched in fatty acid metabolism, amino acid, and carbohydrate metabolism. The hub gene identified from PPI network is fatty acid synthase (FASN). Combined ChIP-seq and transcriptome analysis revealed that the increased H3K27me3 and down-regulated genes have significant enrichment in the ECM-receptor interaction, tight junction, cell adhesion molecules, adherens junction, and TGF-beta signaling pathways.

CONCLUSIONS

Overall, the trimethylation modification of H3K27 has been shown to have significant regulatory function in FLHS, mediating the expression of crucial genes associated with the ECM-receptor interaction pathway. This highlights the epigenetic mechanisms of H3K27me3 and provides insights into exploring core regulatory targets and nutritional regulation strategies in FLHS.

Sodium butyrate alleviates free fatty acid-induced steatosis in primary chicken hepatocytes via the AMPK/PPARα pathway

Fatty liver hemorrhagic syndrome (FLHS) is a prevalent metabolic disorder observed in egg-laying hens, characterized by fatty deposits and cellular steatosis in the liver. Our preliminary investigations have revealed a marked decrease in the concentration of butyric acid in the FLHS strain of laying hens. It has been established that sodium butyrate (NaB) protects against metabolic disorders. However, the underlying mechanism by which butyrate modulates hepato-lipid metabolism to a great extent remains unexplored. In this study, we constructed an isolated in vitro model of chicken primary hepatocytes to induce hepatic steatosis by free fatty acids (FFA). Our results demonstrate that treatment with NaB effectively mitigated FFA-induced hepatic steatosis in chicken hepatocytes by inhibiting lipid accumulation, downregulating the mRNA expression of lipo-synthesis-related genes (sterol regulatory element binding transcription factor 1 (SREBF1), acetyl-CoA carboxylase 1(ACC1), fatty acid synthase (FASN), stearoyl-CoA desaturase 1 (SCD1), liver X receptor α (LXRα), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR)) (P < 0.05), and upregulating the mRNA and protein expression of AMP-activated protein kinase α1 (AMPKα1), peroxisome proliferator-activated receptor α (PPARα), and carnitine palmitoyl-transferase 1A (CPT1A) (P < 0.05). Moreover, AMPK and PPARα inhibitors (Compound C (Comp C) and GW6471, respectively) reversed the protective effects of NaB against FFA-induced hepatic steatosis by blocking the AMPK/PPARα pathway, leading to lipid droplet accumulation and triglyceride (TG) contents in chicken primary hepatocytes. With these findings, NaB can alleviate hepatocyte lipoatrophy injury by activating the AMPK/PPARα pathway, promoting fatty acid oxidation, and reducing lipid synthesis in chicken hepatocytes, potentially being able to provide new ideas for the treatment of FLHS.

Reorganization of 3D genome architecture provides insights into pathogenesis of early fatty liver disease in laying hens

BACKGROUND

Fatty liver disease causes huge economic losses in the poultry industry due to its high occurrence and lethality rate. Three-dimensional (3D) chromatin architecture takes part in disease processing by regulating transcriptional reprogramming. The study is carried out to investigate the alterations of hepatic 3D genome and H3K27ac profiling in early fatty liver (FLS) and reveal their effect on hepatic transcriptional reprogramming in laying hens.

RESULTS

Results show that FLS model is constructed with obvious phenotypes including hepatic visible lipid deposition as well as higher total triglyceride and cholesterol in serum. A/B compartment switching, topologically associating domain (TAD) and chromatin loop changes are identified by high-throughput/resolution chromosome conformation capture (HiC) technology. Targeted genes of these alternations in hepatic 3D genome organization significantly enrich pathways related to lipid metabolism and hepatic damage. H3K27ac differential peaks and differential expression genes (DEGs) identified through RNA-seq analysis are also enriched in these pathways. Notably, certain DEGs are found to correspond with changes in 3D chromatin structure and H3K27ac binding in their promoters. DNA motif analysis reveals that candidate transcription factors are implicated in regulating transcriptional reprogramming. Furthermore, disturbed folate metabolism is observed, as evidenced by lower folate levels and altered enzyme expression.

CONCLUSION

Our findings establish a link between transcriptional reprogramming changes and 3D chromatin structure variations during early FLS formation, which provides candidate transcription factors and folate as targets for FLS prevention or treatment.

Dietary supplementation of magnolol alleviates fatty liver hemorrhage syndrome in postpeak Xinhua laying hens via regulation of liver lipid metabolism

As a metabolic disease, fatty liver hemorrhagic syndrome (FLHS) has emerged as a major cause of noninfectious mortality in laying hens, resulting in substantial economic losses to the poultry industry. This study aimed to investigate the therapeutic effects of magnolol on FLHS in postpeak laying hen model, focusing on lipid metabolism, antioxidative capacity, and potential molecular mechanisms of action. We selected 150 Xinhua laying hens aged 50 wk and divided them into normal diet group (ND), high-fat diet group (HFD), 100 mg/kg magnolol group (MG100), 300 mg/kg magnolol group (MG300), 500 mg/kg magnolol group (MG500) on average. The experiment lasted for 6 wk, and liver samples were collected from the hens at the end of the experiment. The results demonstrated that the inclusion of magnolol in the diet had a significant impact on various factors. It led to a reduction in weight, an increase in egg production rate, a decrease in blood lipid levels, and an improvement in abnormal liver function, liver steatosis, and oxidative stress. These effects were particularly prominent in the MG500 group. The RNA-Seq analysis demonstrated that in the MG500 group, there was a down-regulation of genes associated with fatty acid synthesis (Acc, Fasn, Scd, Srebf1, Elovl6) compared to the HFD group. Moreover, genes related to fatty acid oxidation (CPT1A and PGC1α) were found to be up-regulated. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of these differentially expressed genes indicated their enrichment in the PPAR signaling pathway. These findings demonstrate that magnolol can mitigate FLHS by inhibiting fatty acid synthesis and promoting fatty acid oxidation. This discovery offers a novel approach for treating FLHS in laying hens, reducing the economic losses associate with FLHS.

MTK, Orlowski SK. Effects of Environmental Enrichments on Welfare and Hepatic Metabolic Regulation of Broiler Chickens

The aims of this study were to find suitable environmental enrichment (EE) and evaluate the combined effect of two EEs, variable light intensity (VL) lighting program and EH, on mental health and hepatic metabolic regulation in commercial broilers. To find the advantageous EEs for broilers, three different EEs (board, hut, and ramp) were tested in trial 1. EEs were placed and the engagement of birds to EEs, dustbathing behavior, and daily physical activity were observed. Birds treated with huts showed higher engagement than the board- or ramp-treated birds (p < 0.05). The results of dustbathing behavior and daily physical activity indicated that the environmental hut (EH) is the most favorable enrichment for broilers. In the second trial, to test the effect of EHs on mental health and hepatic metabolic conditions, the brain and liver were sampled from the four treatment birds (20 lx_Con, 20 lx_Hut, VL_Con and VL_Hut) on day 42. The lower expression of TPH2 (tryptophan hydroxylase 2) of VL_Hut birds than those of VL_Con and 20 lx_Hut treated birds suggests the combining effect of EHs with the VL lighting program on the central serotonergic homeostasis of broilers. Reduced expressions of TH (tyrosine hydroxylase), GR (glucocorticoid receptor), BDNF (brain-derived neurotrophic factor) of VL_Hut treated birds compared to those of VL_Con and 20 lx_Hut birds suggest lower stress, stress susceptibility, and chronic social stress in VL_Hut treated birds. The expression of CPT1A (carnitine palmitoyl transferase 1) increased over three-fold in the liver of VL_Con birds compared to 20 lx_Con birds (p < 0.05). EHs treatment in VL birds (VL_Hut) significantly decreased CPT1A but not in 20 lx birds (20 lx_Hut). The expression of ACCα (acetyl-CoA carboxylase alpha) was significantly decreased in VL_Con birds compared to 20 lx_Con birds. There was no significant difference in the hepatic FBPase (fructose-1,6-bisphosphatase), GR, and 11β-HSD1 (11 β-hydroxysteroid dehydrogenease-1) expression between 20 lx_Con and VL_Con birds, but EHs significantly stimulated GR in 20 lx_Hut birds, and stimulated FBPase and 11β-HSD1 expression in the VL_Hut birds compared to 20 lx_Con birds, suggesting that the VL lighting program reduced fatty acid synthesis and increased fatty acid β-oxidation in the broilers' liver and VL_Hut improved the hepatic de novo glucose production. Taken together, the results suggest that the stimulated voluntary activity by EHs in the light-enriched broiler house improved mental health and hepatic metabolic function of broilers and may indicate that the improved hepatic metabolic function contributes to efficient nutritional support for broilers.

Coated sodium butyrate ameliorates high-energy and low-protein diet induced hepatic dysfunction via modulating mitochondrial dynamics, autophagy and apoptosis in laying hens

BACKGROUND

Fatty liver hemorrhagic syndrome (FLHS), a fatty liver disease in laying hens, poses a grave threat to the layer industry, stemming from its ability to trigger an alarming plummet in egg production and usher in acute mortality among laying hens. Increasing evidence suggests that the onset and progression of fatty liver was closely related to mitochondria dysfunction. Sodium butyrate was demonstrated to modulate hepatic lipid metabolism, alleviate oxidative stress and improve mitochondrial dysfunction in vitro and mice models. Nevertheless, there is limited existing research on coated sodium butyrate (CSB) to prevent FLHS in laying hens, and whether and how CSB exerts the anti-FLHS effect still needs to be explored. In this experiment, the FLHS model was induced by administering a high-energy low-protein (HELP) diet in laying hens. The objective was to investigate the effects of CSB on alleviating FLHS with a focus on the role of CSB in modulating mitochondrial function.

METHODS

A total of 288 healthy 28-week-old Huafeng laying hens were arbitrarily allocated into 4 groups with 6 replicates each, namely, the CON group (normal diet), HELP group (HELP diet), CH500 group (500 mg/kg CSB added to HELP diet) and CH750 group (750 mg/kg CSB added to HELP diet). The duration of the trial encompassed a period of 10 weeks.

RESULTS

The result revealed that CSB ameliorated the HELP-induced FLHS by improving hepatic steatosis and pathological damage, reducing the gene levels of fatty acid synthesis, and promoting the mRNA levels of key enzymes of fatty acid catabolism. CSB reduced oxidative stress induced by the HELP diet, upregulated the activity of GSH-Px and SOD, and decreased the content of MDA and ROS. CSB also mitigated the HELP diet-induced inflammatory response by blocking TNF-α, IL-1β, and F4/80. In addition, dietary CSB supplementation attenuated HELP-induced activation of the mitochondrial unfolded protein response (UPRmt), mitochondrial damage, and decline of ATPase activity. HELP diet decreased the autophagosome formation, and downregulated LC3B but upregulated p62 protein expression, which CSB administration reversed. CSB reduced HELP-induced apoptosis, as indicated by decreases in the Bax/Bcl-2, Caspase-9, Caspase-3, and Cyt C expression levels.

CONCLUSIONS

Dietary CSB could ameliorate HELP diet-induced hepatic dysfunction via modulating mitochondrial dynamics, autophagy, and apoptosis in laying hens. Consequently, CSB, as a feed additive, exhibited the capacity to prevent FLHS by modulating autophagy and lipid metabolism.

Osteocalcin activates lipophagy via the ADPN-AMPK/PPARα-mTOR signaling pathway in chicken embryonic hepatocyte

Fatty liver hemorrhage syndrome (FLHS) is the leading cause of noninfectious mortality in caged layers worldwide. Osteocalcin (OCN) is a protein secreted by osteoblasts, and its undercarboxylated form (ucOCN) acts as a multifunctional hormone that protects laying hens from FLHS. Lipophagy is a form of selective autophagy that breaks down lipid droplets (LDs) through lysosomes, and defective lipophagy is associated with FLHS. The aim of this study was to investigate the effects of ucOCN on the lipophagy of chicken embryonic hepatocytes and associated the function of the adiponectin (ADPN) signaling pathway. In this study, chicken embryonic hepatocytes were divided into 5 groups: control (CONT), fat emulsion (FE, 10% FE, v/v), FE with ucOCN at 1 ng/mL (FE-LOCN), 3 ng/mL (FE-MOCN), and 9 ng/mL (FE-HOCN). In addition, 4 μM AdipoRon, an adiponectin receptor agonist, was used to investigate the function of ADPN. The results showed that compared with CONT group, FE promoted the levels of phosphorylation of mammalian target of rapamycin (p-mTOR) (P < 0.05) and decreased the mRNA expression of ADNP receptors (AdipoR1 and AdipoR2). Compared with FE group, 3 and 9 ng/mL ucOCN inhibited the levels of autophagy adaptor p62 and p-mTOR (P < 0.05), increased the ratios of LC3-II/LC3-I (P < 0.05) and phosphorylated adenosine 5'-monophosphate-activated protein kinase (p-AMPK)/AMPK (P < 0.05), as well as the levels of peroxisome proliferator-activated receptor α (PPAR-α) and ADPN (P < 0.05). In addition, ucOCN at the tested concentrations increased the colocalization of LC3 and LDs in fatty hepatocytes. Administrated 4 μM AdipoRon activated AdipoR1 and AidpoR2 mRNA expression (P < 0.05), decreased the concentrations of triglyceride (P < 0.05), without effects on cell viability (P > 0.05). AdipoRon also increased the LC3-II/LC3-I ratio (P < 0.05) and the levels of p-AMPK/AMPK and PPAR-α (P < 0.05). In conclusion, the results reveal that ucOCN regulates lipid metabolism by activating lipophagy via the ADPN-AMPK/PPARα-mTOR signaling pathway in chicken embryonic hepatocytes. The results may provide new insights for controlling FLHS in laying hens.

Sodium Butyrate Alleviates Free Fatty Acid-Induced Steatosis in Primary Chicken Hepatocytes via Regulating the ROS/GPX4/Ferroptosis Pathway

Fatty liver hemorrhagic syndrome (FLHS) in laying hens is a nutritional metabolic disease commonly observed in high-yielding laying hens. Sodium butyrate (NaB) and ferroptosis were reported to contribute to the pathogenesis of fatty liver-related diseases. However, the underlying mechanism of NaB in FLHS and whether it mediates ferroptosis remains unclear. A chicken primary hepatocyte induced by free fatty acids (FFAs, keeping the ratio of sodium oleate and sodium palmitate concentrations at 2:1) was established, which received treatments with NaB, the ferroptosis inducer RAS-selective lethal 3 (RSL3), and the inhibitor ferrostatin-1 (Fer-1). As a result, NaB increased biochemical and lipid metabolism indices, and the antioxidant level, while inhibiting intracellular ROS accumulation and the activation of the ferroptosis signaling pathway, as evidenced by a reduction in intracellular iron concentration, upregulated GPX4 and xCT expression, and inhibited NCOA4 and ACSL4 expression. Furthermore, treatment with Fer-1 reinforced the protective effects of NaB, while RSL3 reversed it by blocking the ROS/GPX4/ferroptosis pathway, leading to the accumulation of lipid droplets and oxidative stress. Collectively, our findings demonstrated that NaB protects hepatocytes by regulating the ROS/GPX4-mediated ferroptosis pathway, providing a new strategy and target for the treatment of FLHS.

Comparative Lipidomics and Metabolomics Reveal the Underlying Mechanisms of Taurine in the Alleviation of Nonalcoholic Fatty Liver Disease Using the Aged Laying Hen Model

SCOPE

Aged laying hen is recently suggested as a more attractive animal model than rodent for studying nonalcoholic fatty liver disease (NAFLD) of humans. This study aims to reveal effects and metabolic regulation mechanisms of taurine alleviating NAFLD by using the aged laying hen model.

METHODS AND RESULTS

Liver histomorphology and biochemical indices show 0.02% taurine effectively alleviated fat deposition and liver damage. Comparative liver lipidomics and gene expressions analyses reveal taurine promoted lipolysis, fatty acids oxidation, lipids transport, and reduced oxidative stress in liver. Furthermore, comparative serum metabolomics screen six core metabolites negatively correlated with NAFLD, including linoleic acid, gamma-linolenic acid, pantothenate, L-methionine, 2-methylbutyroylcarnitine, L-carnitine; and two core metabolites positively correlated with NAFLD, including lysophosphatidylcholine (14:0/0:0) and lysophosphatidylcholine (16:0/0:0). Metabolic pathway analysis reveals taurine mainly regulated linoleic acid metabolism, cysteine and methionine metabolism, carnitine metabolism, pantothenic acid and coenzyme A biosynthesis metabolism, and glycerophospholipid metabolism to up-adjust levels of six negatively correlated metabolites and down-adjust two positively correlated metabolites for alleviating NAFLD of aged hens.

CONCLUSION

This study firstly reveals underlying metabolic mechanisms of taurine alleviating NAFLD using the aged hen model, thereby laying the foundation for taurine's application in the prevention of NAFLD in both human and poultry.

Effects of dietary supplementation with microencapsulated Galla chinensis tannins on growth performance, antioxidant capacity, and lipid metabolism of young broiler chickens

This study aimed to investigate the impacts of dietary supplementation with Galla chinensis tannins (GCT) on the growth performance, antioxidant capacity, and lipid metabolism of young broilers. Overall, a total of 216 healthy 1 day-old broilers were randomly allocated to CON group and GCT group, and provided with a basal diet or a basal diet added with 300 mg/kg microencapsulated GCT, respectively, in a 21 days trial. Our findings indicated that dietary GCT addition had no significant effects (p > 0.05) on growth performance. However, GCT supplementation led to a significant reduction in the total cholesterol (TC) concentration in the serum and liver (p < 0.05). Furthermore, GCT supplementation significantly increased the ratios of high-density lipoprotein (HDL) to low-density lipoprotein (LDL) and HDL to TC in the serum, in addition to elevating the activities of enzymes related to lipid metabolism in the liver (p < 0.05). Dietary GCT addition also improved the antioxidant capacity of the broilers, as evidenced by a significant decrease in the concentration of malondialdehyde in serum and liver (p < 0.05). Additionally, the GCT group exhibited significantly increased expressions of hepatic genes associated with antioxidant enzymes (HO-1, GPX1, SOD2, SIRT1, CPT-1, and PPARα) (p < 0.05), while the mRNA expression of SREBP-1 was significantly decreased (p < 0.05) compared with the CON group. In conclusion, dietary addition of 300 mg/kg microencapsulated GCT improved the antioxidant status and lipid metabolism of broilers without affecting their growth performance.

Ginkgo biloba extract alleviates fatty liver hemorrhagic syndrome in laying hens via reshaping gut microbiota

BACKGROUND

Ginkgo biloba extract (GBE) is evidenced to be effective in the prevention and alleviation of metabolic disorders, including obesity, diabetes and fatty liver disease. However, the role of GBE in alleviating fatty liver hemorrhagic syndrome (FLHS) in laying hens and the underlying mechanisms remain to be elucidated. Here, we investigated the effects of GBE on relieving FLHS with an emphasis on the modulatory role of GBE in chicken gut microbiota.

RESULTS

The results showed that GBE treatment ameliorated biochemical blood indicators in high-fat diet (HFD)-induced FLHS laying hen model by decreasing the levels of TG, TC, ALT and ALP. The lipid accumulation and pathological score of liver were also relieved after GBE treatment. Moreover, GBE treatment enhanced the antioxidant activity of liver and serum by increasing GSH, SOD, T-AOC, GSH-PX and reducing MDA, and downregulated the expression of genes related to lipid synthesis (FAS, LXRα, GPAT1, PPARγ and ChREBP1) and inflammatory cytokines (TNF-α, IL-6, TLR4 and NF-κB) in the liver. Microbial profiling analysis revealed that GBE treatment reshaped the HFD-perturbed gut microbiota, particularly elevated the abundance of Megasphaera in the cecum. Meanwhile, targeted metabolomic analysis of SCFAs revealed that GBE treatment significantly promoted the production of total SCFAs, acetate and propionate, which were positively correlated with the GBE-enriched gut microbiota. Finally, we confirmed that the GBE-altered gut microbiota was sufficient to alleviate FLHS by fecal microbiota transplantation (FMT).

CONCLUSIONS

We provided evidence that GBE alleviated FLHS in HFD-induced laying hens through reshaping the composition of gut microbiota. Our findings shed light on mechanism underlying the anti-FLHS efficacy of GBE and lay foundations for future use of GBE as additive to prevent and control FLHS in laying hen industry.

Analysis of the role of glucose metabolism-related genes in dilated cardiomyopathy based on bioinformatics

BACKGROUND

Dilated cardiomyopathy (DCM) is a prevalent condition with diverse etiologies, including viral infection, autoimmune response, and genetic factors. Despite the crucial role of energy metabolism in cardiac function, therapeutic targets for key genes in DCM's energy metabolism remain scarce.

METHODS

Our study employed the GSE79962 and GSE42955 datasets from the Gene Expression Omnibus (GEO) database for myocardial tissue sample collection and target gene identification via differential gene expression screening. Using various R packages, GSEA software, and the STRING database, we conducted data analysis, gene set enrichment, and protein-protein interaction predictions. The least absolute shrinkage and selection operator (LASSO) and Support Vector Machine (SVM) algorithms aided in feature gene selection, while the predictive model's efficiency was evaluated via the receiver operating characteristic (ROC) curve analysis. We used the non-negative matrix factorization (NMF) method for molecular typing and the cell-type identification by estimating relative subsets of RNA transcripts (CIBERSORT) algorithm for predicting immune cell infiltration.

RESULTS

The DLAT and LDHA genes may regulate the immune microenvironment of DCM by influencing activated dendritic cells, activated mast cells, and M0 macrophages, respectively. The BPGM, DLAT, PGM2, ADH1A, ADH1C, LDHA, and PFKM genes may regulate m6A methylation in DCM by affecting the ZC3H13, ALKBH5, RBMX, HNRNPC, METTL3, and YTHDC1 genes. Further regulatory mechanism analysis suggested that PFKM, DLAT, PKLR, PGM2, LDHA, BPGM, ADH1A, and ADH1C could be involved in the development of cardiomyopathy by regulating the Toll-like receptor signaling pathway.

CONCLUSIONS

PFKM, DLAT, PKLR, PGM2, LDHA, BPGM, ADH1A, and ADH1C may serve as potential targets for guiding the diagnosis, treatment, and follow-up of DCM.

Taurine Protects against the Fatty Liver Hemorrhagic Syndrome in Laying Hens through the Regulation of Mitochondrial Homeostasis

Metabolic-associated fatty liver disease (MAFLD) is a chronic liver disease caused by fat deposition in the liver of humans and mammals, while fatty liver hemorrhagic syndrome (FLHS) is a fatty liver disease in laying hens which can increase the mortality and cause severe economic losses to the laying industry. Increasing evidence has shown a close relationship between the occurrence of fatty liver disease and the disruption of mitochondrial homeostasis. Studies have proven that taurine can regulate hepatic fat metabolism, reduce hepatic fatty deposition, inhibit oxidative stress, and alleviate mitochondrial dysfunction. However, the mechanisms by which taurine regulates mitochondrial homeostasis in hepatocytes need to be further studied. In this study, we determined the effects and mechanisms of taurine on high-energy low-protein diet-induced FLHS in laying hens and in cultured hepatocytes in free fatty acid (FFA)-induced steatosis. The liver function, lipid metabolism, antioxidant capacity, mitochondrial function, mitochondrial dynamics, autophagy, and biosynthesis were detected. The results showed impaired liver structure and function, mitochondrial damage and dysfunction, lipid accumulation, and imbalance between mitochondrial fusion and fission, mitochondrial autophagy, and biosynthesis in both FLHS hens and steatosis hepatocytes. Taurine administration can significantly inhibit the occurrence of FLHS, protect mitochondria in hepatocytes from disease induced by lipid accumulation and FFA, up-regulate the expression levels of Mfn1, Mfn2, Opa1, LC3I, LC3II, PINK1, PGC-1α, Nrf1, Nrf2, and Tfam, and down-regulate the expression levels of Fis1, Drp1, and p62. In conclusion, taurine can protect laying hens from FLHS through the regulation of mitochondrial homeostasis, including the regulation of mitochondrial dynamics, autophagy, and biosynthesis.

Comprehensive Proteome and Acetyl-Proteome Atlas Reveals Hepatic Lipid Metabolism in Layer Hens with Fatty Liver Hemorrhagic Syndrome

The feeding of high-energy and low-protein diets often induces fatty liver hemorrhagic syndrome (FLHS) in laying hens. However, the mechanism of hepatic fat accumulation in hens with FLHS remains uncertain. In this research, a comprehensive hepatic proteome and acetyl-proteome analysis was performed in both normal and FLHS-affected hens. The results indicated that the upregulated proteins were primarily associated with fat digestion and absorption, the biosynthesis of unsaturated fatty acids, and glycerophospholipid metabolism, while the downregulated proteins were mainly related to bile secretion and amino acid metabolism. Furthermore, the significant acetylated proteins were largely involved in ribosome and fatty acid degradation, and the PPAR signaling pathway, while the significant deacetylated proteins were related to valine, leucine, and isoleucine degradation in laying hens with FLHS. Overall, these results demonstrate that acetylation inhibits hepatic fatty acid oxidation and transport in hens with FLHS, and mainly exerts its effects by affecting protein activity rather than expression. This study provides new nutritional regulation options to alleviate FLHS in laying hens.

Osteocalcin and Its Potential Functions for Preventing Fatty Liver Hemorrhagic Syndrome in Poultry

Osteocalcin (OCN) is synthesized and secreted by differentiating osteoblasts. In addition to its role in bone, OCN acts as a hormone in the pancreas, liver, muscle, fat, and other organs to regulate multiple pathophysiological processes including glucose homeostasis and adipic acid metabolism. Fat metabolic disorder, such as excessive fat buildup, is related to non-alcoholic fatty liver disease (NAFLD) in humans. Similarly, fatty liver hemorrhage syndrome (FLHS) is a metabolic disease in laying hens, resulting from lipid accumulation in hepatocytes. FLHS affects hen health with significant impact on poultry egg production. Many studies have proposed that OCN has protective function in mammalian NAFLD, but its function in chicken FLHS and related mechanism have not been completely clarified. Recently, we have revealed that OCN prevents laying hens from FLHS through regulating the JNK pathway, and some pathways related to the disease progression have been identified through both in vivo and vitro investigations. In this view, we discussed the current findings for predicting the strategy for using OCN to prevent or reduce FLHS impact on poultry production.

Effects and potential mechanism of dietary vitamin C supplementation on hepatic lipid metabolism in growing laying hens under chronic heat stress

The adverse effects of chronic heat stress (CHS)-induced fatty liver syndrome on laying hens during the egg-producing stages have been wildly documented. However, until nowadays, the CHS responses of growing laying hens as well as its alleviating effects of vitamin C are rarely reported. In this study, 12-wk-old laying hens were subjected to CHS at 36 °C for 10 h/d for 3 wk with or without dietary supplementation of 300 mg/kg vitamin C. Results showed that CHS significantly impaired the growth performances and the liver functions of birds, as characterized by reduced feed intake and body weight, increased hepatic lipid accumulation and serum concentrations of TG, ALT, and AST, as well as the abnormal expression patterns of the lipid metabolism-related genes. Vitamin C supplementation successfully mitigated the lipid accumulation, while showing no alleviating effect on the serum contents of ALT or AST, which are two key indicators of liver functions. Metabolomic analysis based on UPLC-Q-TOF/MS identified 173 differential metabolites from the HS and HSV group samples, and they are mainly enriched in the pathways related to the cellular components, vitamin and amino acid metabolism and energy substance metabolism. The results indicate that CHS-induced hepatic lipid deposition in growing laying hens is effectively alleviated by dietary supplementation of vitamin C, which is probably resulted from the alterations of hepatocellular metabolic patterns.

Oleic acid-induced steatosis model establishment in LMH cells and its effect on lipid metabolism

Hepatic steatosis is a highly prevalent liver disease, yet research on it is hampered by the lack of tractable cellular models in poultry. To examine the possibility of using organoids to model steatosis and detect it efficiently in leghorn male hepatocellular (LMH) cells, we first established steatosis using different concentrations of oleic acid (OA) (0.05-0.75 mmol/L) for 12 or 24 h. The subsequent detections found that the treatment of LMH cells with OA resulted in a dramatic increase in intracellular triglyceride (TG) concentrations, which was positively associated with the concentration of the inducing OA (R2 > 0.9). Then, the modeled steatosis was detected by flow cytometry after NileRed staining and it was found that the intensity of NileRed-A was positively correlated with the TG concentration (R2 > 0.93), which demonstrates that the flow cytometry is suitable for the detection of steatosis in LMH cells. According to the detection results of the different steatosis models, we confirmed that the optimal induction condition for the establishment of the steatosis model in LMH cells is OA (0.375 mmol/L) incubation for 12 h. Finally, the transcription and protein content of fat metabolism-related genes in steatosis model cells were detected. It was found that OA-induced steatosis could significantly decrease the expression of nuclear receptor PPAR-γ and the synthesis of fatty acids (SREBP-1C, ACC1, FASN), increasing the oxidative decomposition of triglycerides (CPT1A) and the assembly of low-density lipoproteins (MTTP, ApoB). Sterol metabolism in model cells was also significantly enhanced (HMGR, ABCA1, L-BABP). This study established, detected, and analyzed an OA-induced steatosis model in LMH cells, which provides a stable model and detection method for the study of poultry steatosis-related diseases.

Quantitative lipidomics reveals lipid perturbation in the liver of fatty liver hemorrhagic syndrome in laying hens

Fatty liver hemorrhagic syndrome (FLHS) is a metabolic disease that causes decreased egg production and even death in laying hens, which brings huge economic losses to the poultry industry. However, the pathogenesis of FLHS is unclear. The purpose of the present study was to identify the changes in lipid profile and the lipid species related to FLHS. In the present study, the FLHS disease model in Chinese commercial Jing Fen laying hens was induced by a high-energy low-protein diet. A lipidomics approach based on ultra-performance liquid chromatography-mass spectrometry coupled with multivariate statistical analysis was performed for the qualitative and quantitative analyses of the liver lipids. The results showed that a total of 29 lipid subclasses, including 1,302 lipid species, were detected and identified. Among them, the proportions of phosphatidylserine (Control/FLHS, 33.1% vs. 29.1%), phosphatidylethanolamine (22.7% vs. 15.5%), phosphatidylcholine (15.7% vs. 11.7%) and phosphatidylinositol (7% vs. 6%) were reduced, while triacylglycerol (7.1% vs. 18.3%) and diglyceride (3.9% vs. 11.7%) were increased. Between the Control and FLHS groups, distinct changes in lipid profile were observed in the score plots of principal component analysis and orthogonal partial least squares discriminant analysis. Twelve differential lipid species mainly involved in glycerophospholipid metabolism and linoleic acid metabolism were identified and considered to be related to the pathogenesis of FLHS. Fatty acid chain length and unsaturation were reduced, while the mRNA levels of elongation of very long chain fatty acids-2 (ELOVL2) were increased in the liver of laying hens with FLHS. Collectively, this study characterized the liver lipid profile and explored the changes in lipid species related to FLHS, which provided insights into the pathogenesis of FLHS from the view of lipid metabolism.

How to employ metabolomic analysis to research on functions of prebiotics and probiotics in poultry gut health?

Gut health can be considered one of the major, manageable constituents of the animal immunity and performance. The fast spread of intestinal diseases, and increase of antimicrobial resistance have been observed, therefore the intestinal health has become not only economically relevant, but also highly important subject addressing the interest of public health. It is expected, that the strategies to control infections should be based on development of natural immunity in animals and producing resilient flocks using natural solutions, whilst eliminating antibiotics and veterinary medicinal products from action. Probiotics and prebiotics have been favored, because they have potential to directly or indirectly optimize intestinal health by manipulating the metabolism of the intestinal tract, including the microbiota. Studying the metabolome of probiotics and gut environment, both in vivo, or using the in vitro models, is required to attain the scientific understanding about the functions of bioactive compounds in development of gut health and life lasting immunity. There is a practical need to identify new metabolites being the key bioactive agents regulating biochemical pathways of systems associated with gut (gut-associated axes). Technological advancement in metabolomics studies, and increasing access to the powerful analytical platforms have paved a way to implement metabolomics in exploration of the effects of prebiotics and probiotics on the intestinal health of poultry. In this article, the basic principles of metabolomics in research involving probiotics and probiotics are introduced, together with the overview of existing strategies and suggestions of their use to study metabolome in poultry.

Punicalagin: a monomer with anti-Eimeria tenella effect from Fruit peel of Punica granatum L

Poultry production was long plagued by coccidiosis, and the development of alternative therapies will make practical sense. In this work, 2 battery experiments were designed. In battery experiment 1, the best effect of 7 anticoccidial herbs (Sophora japonica Linn, Citrus aurantium L, leaf of Acer palmatum, bark of Magnolia officinalis, fruit peel of Punica granatum L., Eclipta prostrata L., and Piper sarmentosum Roxb.) against Eimeria tenella infection of 21-day-old male Chinese Guangxi yellow-feathered chickens were screened out by clinic indexes (bloody feces scores, cecal lesion scores, oocysts output, relative weight gain rate, and survival rate). According to the results from battery experiment 1 and other literature research, we selected 2 monomers which were extracted from fruit peel of Punica granatum L. for further battery experiment 2 which were similar with battery experiment 1. Clinic results showed that Punicalagin had better anticoccidial effect than Ellagic acid. The anticoccidial mechanism exploration results of Elisa, antioxidant test, and pathological observation showed that Punicalagin reduced the cecal inflammation, improved the expression of immunoglobulin in cecal tissue, improved cecal integrity, and restored its REDOX state. Results of 16S rRNA sequencing analysis showed that Punicalagin also maintained the fecal flora health during E. tenella infection through insignificantly increasing the proportion of Lactobacillus and Faecalibacterium as well as significantly reducing the proportion of pathogenic bacteria, Escherichia–Shigella. RNA-Seq analysis results suggested that Punicalagin may play a role in controlling E. tenella infection by interaction with cytochrome P450 family enzymes. Overall, Punicalagin has promising potential as an alternative therapy for chicken Eimeria tenella infection.

Dietary γ-Aminobutyric Acid Supplementation Inhibits High-Fat Diet-Induced Hepatic Steatosis via Modulating Gut Microbiota in Broilers

The present study aims to investigate the effect of γ-aminobutyric acid (GABA) on liver lipid metabolism and on AA broilers. Broilers were divided into three groups and fed with low-fat diets, high-fat diets, and high-fat diets supplemented with GABA. Results showed that GABA supplementation decreased the level of triglyceride (TG) in the serum and liver of broilers fed high-fat diets, accompanied by up-regulated mRNA expression of genes related to lipolysis and β-oxidation in the liver (p < 0.05). Furthermore, GABA supplementation increased liver antioxidant capacity, accompanied by up-regulated mRNA expression of antioxidant genes (p < 0.05). 16S rRNA gene sequencing showed that GABA improved high-fat diet-induced dysbiosis of gut microbiota, increased the relative abundance of Bacteroidetes phylum and Barnesiella genus, and decreased the relative abundance of Firmicutes phylum and Ruminococcus_torques_group and Romboutsia genus (p < 0.05). Moreover, GABA supplementation promoted the production of propionic acid and butyric acid in cecal contents. Correlation analysis further suggested the ratio of Firmicutes/Bacteroidetes negatively correlated with hepatic TG content, and positively correlated with cecal short chain fatty acids content (r > 0.6, p < 0.01). Together, these data suggest that GABA supplementation can inhibit hepatic TG deposition and steatosis via regulating gut microbiota in broilers.

Integrated Analyses of Gut Microbiome and Host Metabolome in Children With Henoch-Schönlein Purpura

Recent studies have shown that intestinal microbes and metabolites are involved in the pathogenesis of many diseases. However, whether and how they are related to Henoch–Schönlein purpura (HSP) has yet to be understood. This work is designed to detect gut microbes, intestinal and serum metabolites in children with HSP, trying to discover the etiology and pathogenesis of HSP. A total of 86 children were recruited in this study, namely, 58 children with HSP (HSP group) and 28 healthy children as control groups (CON group). 16S rDNA amplicon sequencing technology and UPLC-QTOF/MS non-targeted metabolomics analysis were used to detect the intestinal microbes and metabolites, and also multi-reaction monitoring technology for detecting serum arachidonic acid (AA) and its metabolites. Then, correlation analysis was performed to explore the possible interaction between the differential gut microbes and metabolites. As a result, at the microbiota family level, the CON group had an advantage of Coriobacteriaceae while the HSP group had a dominant Bacteroidaceae. Five kinds of bacteria in the HSP group were significantly enriched at the genus level, and seven kinds of bacteria were significantly enriched in the CON group. A total of 59 kinds of gut metabolites significantly differ between the two groups, in which most are lipids and peptides. Spearman correlation analysis showed that Bacteroides, Dialister, and Agathobacter were associated with unsaturated fatty acids, especially AA metabolism. Then, we tested the AA related metabolites in serum and found thromboxane B2, leukotriene B4, prostaglandin D2, 9S-hydroxyoctadecadienoic acid, and 13S-hydroxyoctadecadienoic acid significantly changed. In conclusion, children with HSP had dominant Bacteroidaceae and decreased Coriobacteriaceae in the family level of gut microbes, and also lipids and peptides changed most in the gut metabolites. Our data suggested that the biosynthesis and metabolism of unsaturated fatty acids, especially AA and its metabolites, might participate in the occurrence and development of HSP.