Sodium Butyrate Mitigates iE-DAP Induced Inflammation Caused by High-Concentrate Feeding in Liver of Dairy Goats

Short-term effects of Subacute ruminal acidosis on ferroptosis and iron metabolism in the livers of lactating sheep fed a high-grain diet

Subacute ruminal acidosis can cause liver injury in ruminants. Ferroptosis, an iron-dependent cell death, is involved in many liver diseases. This study aimed to investigate ferroptosis in SARA-induced liver injury and explore the changes in hepatic iron metabolism. Twelve ruminally cannulated, lactating Hu sheep (parities: 2 or 3; BW: 50.6 ± 4.0 kg; 18.8 ± 3.6 d in milk; MY: 0.52 ± 0.08 kg/d; mean ± SD) were divided into 2 groups (n = 6/group) and fed a low-grain diet (LG group, grain: forage = 3: 7, 24.89% starch and 40.66% NDF) or a high-grain diet (HG group, grain: forage = 7: 3, 38.64% starch and 24.41% NDF) for 8 wk. Weekly, rumen pH was measured 10 min before feeding and 1, 2, 3, 4, 5, 6, and 8 h post-feeding. On d 57, all sheep were slaughtered after collecting the hepatic vein blood, and liver tissue was collected. The high-grain diet significantly decreased rumen pH compared with the low-grain diet; the rumen pH on d 56 in the HG group was <5.6 at 1, 2, 3, and 4 h after feeding. Plasma concentrations of LPS, MDA, IL-1β, and IL-6 at 4 h post-feeding increased, while glutathione (GSH) and glutathione peroxidase 4 (GPX4) decreased. Moreover, lipid reactive oxygen species (lipid ROS), ferrous ion, and MDA were elevated, whereas GSH was decreased in the liver of the HG group. For ferroptosis-related proteins, feeding a high-grain diet led to increased acyl-CoA synthetase long-chain family member 4 (ACSL4) and arachidonate 15-lipoxygenase (ALOX15) and decreased GPX4 and solute carrier family 7 member 11 (SLC7A11). For ferritinophagy-related proteins, high-grain diet feeding decreased ferritin heavy chain 1 (FTH1) and increased nuclear receptor coactivator 4 (NCOA4) and microtubule-associated protein 1 light chain 3 II (MAP1LC3-II). Regarding iron metabolism, increased protein expression of nuclear mothers against decapentaplegic homolog1/5/8 (SMAD1/5/8) and hepcidin, decreased protein expression of ferroportin (FPN), and iron deposits were observed in the liver of the HG group. Furthermore, feeding high-grain diets also increased inflammatory signaling-related proteins IL-6 and phospho-signal transducer and activator of transcription 3 (p-STAT3). Taken together, this study suggests that SARA induced liver injury and ferroptosis. Enhanced ferritinophagy, disordered iron metabolism, and elevated inflammatory response may mediate ferroptosis in the livers of sheep fed a high-grain diet.

Ileal microbial microbiome and its secondary bile acids modulate susceptibility to nonalcoholic steatohepatitis in dairy goats

BACKGROUND

Liver damage from nonalcoholic steatohepatitis (NASH) presents a significant challenge to the health and productivity of ruminants. However, the regulatory mechanisms behind variations in NASH susceptibility remain unclear. The gut‒liver axis, particularly the enterohepatic circulation of bile acids (BAs), plays a crucial role in regulating the liver diseases. Since the ileum is the primary site for BAs reabsorption and return to the liver, we analysed the ileal metagenome and metabolome, liver and serum metabolome, and liver single-nuclei transcriptome of NASH-resistant and susceptible goats together with a mice validation model to explore how ileal microbial BAs metabolism affects liver metabolism and immunity, uncovering the key mechanisms behind varied NASH pathogenesis in dairy goats.

RESULTS

In NASH goats, increased total cholesterol (TC), triglyceride (TG), and primary BAs and decreased secondary BAs in the liver and serum promoted hepatic fat accumulation. Increased ileal Escherichia coli, Erysipelotrichaceae bacterium and Streptococcus pneumoniae as well as proinflammatory compounds damaged ileal histological morphology, and increased ileal permeability contributes to liver inflammation. In NASH-tolerance (NASH-T) goats, increased ursodeoxycholic acid (UDCA), isodeoxycholic acid (isoDCA) and isolithocholic acid (isoLCA) in the liver, serum and ileal contents were attributed to ileal secondary BAs-producing bacteria (Clostridium, Bifidobacterium and Lactobacillus) and key microbial genes encoding enzymes. Meanwhile, decreased T-helper 17 (TH17) cells and increased regulatory T (Treg) cells proportion were identified in both liver and ileum of NASH-T goats. To further validate whether these key BAs affected the progression of NASH by regulating the proliferation of TH17 and Treg cells, the oral administration of bacterial UDCA, isoDCA and isoLCA to a high-fat diet-induced NASH mouse model confirmed the amelioration of NASH through the TH17 cell differentiation/IL-17 signalling/PPAR signalling pathway by these bacterial secondary BAs.

CONCLUSION

This study revealed the roles of ileal microbiome and its secondary BAs in resilience and susceptibility to NASH by affecting the hepatic Treg and TH17 cells proportion in dairy goats. Bacterial UDCA, isoDCA and isoLCA were demonstrated to alleviate NASH and could be novel postbiotics to modulate and improve the liver health in ruminants. Video Abstract.

Nutrition, gastrointestinal microorganisms and metabolites in mastitis occurrence and control

Mastitis affects almost all mammals including humans and dairy cows. In the dairy industry, bovine mastitis is a disease with a persistently high incidence, causing serious losses to the health of cows, the quality of dairy products, and the economy of dairy farms. Although local udder infection caused by the invasion of exogenous pathogens into the mammary gland was considered the main cause of mastitis, evidence has been established and continues to grow, showing that nutrition factors and gastrointestinal microbiome (GM) as well as their metabolites are also involved in the development of mammary inflammatory response. Suboptimal nutrition is recognized as a risk factor for increased susceptibility to mastitis in cattle, in particular the negative energy balance. The majority of data regarding nutrition and bovine mastitis involves micronutrients. In addition, the dysbiotic GM can directly trigger or aggravate mastitis through entero-mammary gland pathway. The decreased beneficial commensal bacteria, lowered bacterial diversity, and increased pathogens as well as proinflammatory metabolites are found in both the milk and gastrointestinal tract of mastitic dairy cows. This review discussed the relationship between the nutrition (energy and micronutrient levels) and mastitis, summarized the role of GM and metabolites in regulating mastitis. Meanwhile, several non-antibiotics strategies were provided for the prevention and alleviation of mastitis, including micronutrients, probiotics, short-chain fatty acids, high-fiber diet, inulin, and aryl hydrocarbon receptor.

Zearalenone promotes porcine ESCs apoptosis by enhancing Drp1-mediated mitochondrial fragmentation and activating the JNK pathway

Zearalenone (ZEA) is widely present in food and feed, and pigs are susceptible to its effects. This study explored the underlying function of ZEA-induced apoptosis in porcine endometrial stromal cells (ESCs) through activation of the JNK signaling pathway and mitochondrial division. This study utilized ESCs to explore the impact of exposure to ZEA. A mitochondrial division inhibitor (Mdivi) was also included as a reference. The results indicated a gradual decrease in cell viability with increasing ZEA concentration. In addition, ZEA can modify the growth status of porcine ESCs, disrupt their ultrastructure, and lead to apoptosis of porcine ESCs via the mitochondrial division pathway and JNK signaling pathway. In summary, our study found the critical targets of ZEA infected with pig ESCs, which provided a conceptual foundation to prevent and control ZEA.

Effects of dietary disodium fumarate supplementation on muscle quality, chemical composition, oxidative stress and lipid metabolism of Hu sheep induced by high concentrate diet

Long-term feeding of high-concentrate (HC) diet causes the decrease of rumen pH, and induces subacute rumen acidosis (SARA), which results in metabolic disorders in sheep. This not only reduces animal performance, but also increases the risk of oxidative stress and inflammatory reaction. Disodium fumarate can improve the rumen buffering capacity and increase rumen pH. This experiment was conducted to investigate the effects of high concentrate diet on muscle quality, chemical composition, oxidative damage and lipid metabolism of Hu sheep, and the regulating effect of disodium fumarate. The results showed that HC diet induced SARA by reducing rumen pH value, thus causing oxidative stress and lipid metabolism disorder in longissimus lumborum (LL) muscle of Hu sheep, which also reduced meat quality by increasing shear force, drip loss, cooking loss, chewiness and hardness, and reducing the contents of crude fat and crude protein in LL muscle. However, disodium fumarate can improve meat quality of SARA Hu sheep by regulating rumen pH, inhibiting muscle oxidative stress and promoting lipid metabolism.

Forkhead box protein A2 alleviates toll-like receptor 4-mediated inflammation, endoplasmic reticulum stress, autophagy, and apoptosis induced by lipopolysaccharide in bovine hepatocytes

Lipopolysaccharide (LPS) is an important stimulus of inflammation via binding to toll-like receptor 4 (TLR4), but the role of TLR4 in LPS-induced cellular homeostasis disruption indicated by the increased level of endoplasmic reticulum (ER) stress, autophagy, and apoptosis is unknown in the liver of dairy cows. Previous studies show that forkhead box protein A2 (FOXA2) is an important transcriptional factor to maintain cellular metabolic homeostasis, but the mechanisms by which FOXA2 mediates cellular homeostasis disruption in response to LPS remains unclear. To achieve the aims, hepatocytes separated from dairy cows at ∼160 d in milk were pretreated with a specific TLR4 inhibitor TAK-242 for 12 h, followed by LPS treatment for another 12 h to investigate the role of TLR4 in LPS-induced disruption of cellular homeostasis. The results indicated that LPS-induced nuclear factor-κB (NF-κB)-mediated inflammatory cascades, ER stress, autophagy, and apoptosis via activating TLR4 and downregulating FOXA2 expression in bovine hepatocytes. The application of TLR4 inhibitor alleviated LPS-induced inflammation through inactivating NF-κB proinflammatory pathway, restored cell homeostasis by decreasing the level of ER stress, autophagy, and apoptosis, and upregulated FOXA2 expression. Furthermore, we also elevated FOXA2 expression with an overexpression plasmid to clarify its molecular role in response to LPS challenge. FOXA2 overexpression reduced LPS-caused inflammation by inhibiting NF-κB signaling pathway. Also, FOXA2 could alleviate ER stress to block unfolded protein response and suppress autophagic flux. In addition, FOXA2 enhanced mitochondrial membrane potential via reducing pro-apoptotic protein BAX, CASPASE3, and Cleaved CASPASE3 expression and elevating anti-apoptotic protein BCL-2 expression to mitigate LPS-induced apoptosis. Taken together, these findings suggested that FOXA2 is a mediator to alleviate TLR4-controlled inflammation, ER stress, autophagy, and apoptosis in LPS-treated bovine hepatocytes, it could serve as a potential target to intervene cell homeostasis disruption caused by LPS in the liver of dairy cows.

Ameliorative effects of supranutritional selenium on TLR-4-NF-kB-TNF-α-mediated hepatic oxidative injury and inflammation in goats fed high concentrate diet

We examined whether surplus dietary selenium (Se) supply could alleviate high concentrate (HC) diet-induced hepatic oxidative stress (OS) and inflammation. Eighteen young goats were distributed into three groups; were fed low (LC, concentrate: forage; 35: 65), high concentrate (HC, 65: 35), or Se-supplemented HC (HCSe, 65: 35 + 0.5 mg Se kg-1 diet) diets for 10 weeks. Short chain fatty acids, OS markers and immunoinflammatory genes expressions were assessed through gas chromatograph, kits, and RT-qPCR, respectively. Compared with LC, HC diet increased (p < .05) colonic and serum lipopolysaccharide (LPS) levels and induced hepatic oxidative injury by increasing (p < .05) malondialdehyde (MDA) levels and decreasing (p < .05) activities of glutathione peroxidase, superoxide dismutase, and catalase. HC diet altered hepatic mRNA expressions of toll-like receptor-4 (TLR-4), cluster of differentiation-14 (CD-14), tumor necrosis factor-α (TNF-α), TNF receptor-associated factor-6 (TRAF-6), nuclear factor kappa B (NF-κB), interleukin-1β (IL-1β), IL-10, IL-13, LPS-binding protein (LBP), serum amyloid A (SAA), α-acid glycoprotein (AGP), and albumin (ALB). Conversely, extra-Se supply lowered LPS and attenuated antioxidant status and inflammation in liver. In conclusion, HC diet induced oxidative lesions and TLR-4 pathway-mediated inflammation, whereas supranutritional Se alleviated oxidative and inflammatory lesions through TLR-4 pathway regulation in goat liver.

The Role of Rumen Microbiota and Its Metabolites in Subacute Ruminal Acidosis (SARA)-Induced Inflammatory Diseases of Ruminants

Subacute ruminal acidosis (SARA) is a common metabolic disease in ruminants. In the early stage of SARA, ruminants do not exhibit obvious clinical symptoms. However, SARA often leads to local inflammatory diseases such as laminitis, mastitis, endometritis and hepatitis. The mechanism by which SARA leads to inflammatory diseases is largely unknown. The gut microbiota is the totality of bacteria, viruses and fungi inhabiting the gastrointestinal tract. Studies have found that the gut microbiota is not only crucial to gastrointestinal health but also involved in a variety of disease processes, including metabolic diseases, autoimmune diseases, tumors and inflammatory diseases. Studies have shown that intestinal bacteria and their metabolites can migrate to extraintestinal distal organs, such as the lung, liver and brain, through endogenous pathways, leading to related diseases. Combined with the literature, we believe that the dysbiosis of the rumen microbiota, the destruction of the rumen barrier and the dysbiosis of liver function in the pathogenesis of SARA lead to the entry of rumen bacteria and/or metabolites into the body through blood or lymphatic circulation and place the body in the "chronic low-grade" inflammatory state. Meanwhile, rumen bacteria and/or their metabolites can also migrate to the mammary gland, uterus and other organs, leading to the occurrence of related inflammatory diseases. The aim of this review is to describe the mechanism by which SARA causes inflammatory diseases to obtain a more comprehensive and profound understanding of SARA and its related inflammatory diseases. Meanwhile, it is also of great significance for the joint prevention and control of diseases.

A high-concentrate diet provokes inflammatory responses by downregulating Forkhead box protein A2 (FOXA2) through epigenetic modifications in the liver of dairy cows

A high-concentrate diet has been reported to promote an inflammatory response in dairy cows. The purpose of this study was to clarify the effect of the high-concentrate (HC) diet on hepatic Forkhead box protein A2 (FOXA2) expression and uncover the molecular mechanisms in inflammatory responses in the liver. The results showed that the HC diet reduced the ruminal fluid pH and elevated the secretion of SAA3, IL-1α, and IL-8 and reduced that of IL-10 in peripheral blood plasma. Compared with the low-concentrate (LC) group, the concentration of myeloperoxidase (MPO) was higher in the liver of dairy cows in the HC group. In addition, the relative mRNA expression of acute phase proteins (HP, SAA3, and LBP), proinflammatory cytokines (TNFα, IL-1α, IL-1β, IL-8), TLR4, MyD88, TRAF6, TRIF, IκBα, p65, p38 and JNK1 was upregulated and that of IL-10 was downregulated in the liver of the HC group. Consistently, the protein abundance of TLR4, TNFα and phosphorylation of proteins involved in NF-κB (IκBα and p65) and MAPK (p38 and JNK) pathways were significantly increased in the HC group compared with the LC group. And both the mRNA and protein abundance of FOXA2 were downregulated in the HC group. Further epigenetic analysis results demonstrated that chromatin compaction and DNA hypermethylation contributed to inhibiting FOXA2 expression, in which the demethylase ten-eleven translocation 1 (TET1) and histone deacetylase 3 (HDAC3) might participate. Overall, these findings demonstrated that the high-concentrate diet triggered inflammatory cascades and downregulated FOXA2 by epigenetic modifications in the liver of dairy cows.

Standardized Astragalus Mongholicus Bunge-Curcuma Aromatica Salisb. Extract Efficiently Suppresses Colon Cancer Progression Through Gut Microbiota Modification in CT26-Bearing Mice

Altered gut microbiota and a damaged colon mucosal barrier have been implicated in the development of colon cancer. Astragalus mongholicus Bunge-Curcuma aromatica Salisb. (ACE) is a common herbal drug pair that widely used clinically to treat cancer. However, whether the anti-cancer effect of ACE is related to gut microbiota remains unclear yet. We standardized ACE and investigated the effects of ACE on tumour suppression and analyze the related mechanisms on gut microbiota in CT26 colon cancer-bearing mice in the present study. Firstly, four flavonoids (calycosin-7-glucoside, ononin, calycosin, formononetin) and three astragalosides (astragaloside A, astragaloside II, astragaloside I) riched in Astragalus mongholicus Bunge, three curcumins (bisdemethoxycurcumin, demethoxycurcumin, curcumin) and four essential oils (curdione, curzerene, germacrone and β-elemene) from Curcuma aromatica Salisb., in concentrations from 0.08 to 2.07 mg/g, were examined in ACE. Then the results in vivo studies indicated that ACE inhibited solid tumours, liver and spleen metastases of colon cancer while simultaneously reducing pathological tissue damage. Additionally, ACE regulated gut microbiota dysbiosis and the short chain fatty acid content in the gut, repaired intestinal barrier damage. ACE treatment suppressed the overgrowth of conditional pathogenic gut bacteria, including Escherichia-Shigella, Streptococcus and Enterococcus, while the probiotic gut microbiota like Lactobacillus, Roseburia, Prevotellaceae_UCG-001 and Mucispirillum were increased. More interestingly, the content level of SCFAs such as propionic acid and butyric acid was increased after ACE administration, which further mediates intestinal SDF-1/CXCR4 signalling pathway to repair the integrity of the intestinal barrier, decrease Cyclin D1 and C-myc expressions, eventually suppress the tumor the growth and metastasis of colon cancer. To sum up, the present study demonstrated that ACE could efficiently suppress colon cancer progression through gut microbiota modification, which may provide a new explanation of the mechanism of ACE against colon cancer.

Sodium Butyrate More Effectively Mitigates the Negative Effects of High-Concentrate Diet in Dairy Cows than Sodium β-Hydroxybutyrate via Reducing Free Bacterial Cell Wall Components in Rumen Fluid and Plasma

The present study was aimed at investigating the effects of sodium butyrate and sodium β-hydroxybutyrate on lactation and health of dairy cows fed a high-concentrate (HC) diet. Eighty mid-lactation dairy cows with an average milk yield of 33.75 ± 5.22 kg/d were randomly allocated to four groups (n = 20 per group) and were fed either a low-concentrate (LC) diet, a HC diet, the HC diet with 1% sodium butyrate (HCSB), or the HC diet with 1% sodium β-hydroxybutyrate (HCHB). The feeding trial lasted for 7 weeks, with a 2-week adaptation period and a 5-week measurement period, and the trial started from 96 ± 13 d in milk. Sodium butyrate supplementation delayed the decline in milk production and improved milk synthesis efficiency and milk fat content. Additionally, it decreased the proinflammatory cytokines and acute phase proteins (APPs) in plasma, the leucocytes in blood, the somatic cell count (SCC) in milk, and the gene expression of pattern recognition receptors (PRRs) and proinflammatory cytokines in the mammary gland, due to decreasing the contents of bacterial cell wall components (lipopolysaccharide, LPS; peptidoglycan, PGN; and lipoteichoic acid, LTA) in the rumen and plasma, compared with the HC diet. Sodium β-hydroxybutyrate supplementation also improved milk yield, milk synthesis efficiency and milk fat content and partially reduced the adverse effects caused by the HC diet, but it had no effect on decreasing bacterial cell wall components in the rumen and plasma, compared with the HC diet. Collectively, both sodium butyrate and sodium β-hydroxybutyrate mitigated the negative effects of HC diet on lactation and health of dairy cows, with sodium butyrate being more effective than sodium β-hydroxybutyrate.

γ-d-Glutamyl-meso-diaminopimelic acid induces autophagy in bovine hepatocytes during nucleotide-binding oligomerization domain 1-mediated inflammation

Autophagy is a crucial cellular homeostatic process and an important part of the host defense system. Dysfunction in autophagy enhances tissue susceptibility to infection and multiple diseases. However, the role of nucleotide oligomerization domain 1 (NOD1) in autophagy in bovine hepatocytes is not well known. Therefore, our aim was to study the contribution of NOD1 to autophagy during inflammation in response to a specific ligand γ-d-glutamyl-meso-diaminopimelic acid (iE-DAP). To achieve this aim, hepatocytes separated from cows at ∼160 days in milk (DIM) were divided into six groups: the nontreated control (CON) group, the rapamycin-treated (RAP) group as a positive control, the iE-DAP-treated (DAP) group, the 3-MA-treated (MA) group, the rapamycin with 3-MA (RM) group, and the iE-DAP with 3-MA (DM) group. iE-DAP administration significantly increased the mRNA expression of NOD1, ATG16L1, RIPK2, ULK1, AMBRA1, DFCP1, WIPI1, ATG5, ATG7, ATG10, ATG4A, IκBα, NF-κB, CXCL1, IL-8, and STAT6 and significantly decreased PIK3C3. The protein expression of NOD1, p-IκBα, p-NF-κB/p-p65, LC3-II, ATG5, and beclin 1 were significantly upregulated and that of SQSTM1/p62, p-mTOR, and FOXA2 were significantly downregulated in response to iE-DAP. iE-DAP also induced the formation of LC3-GFP autophagic puncta in bovine hepatocytes. We also knocked down the NOD1 with siRNA. NOD1 silencing suppressed the autophagy and inflammation-related genes and proteins. The application of the autophagy inhibitor increased the expression of inflammatory molecules and alleviated autophagy-associated molecules. Taken together, these findings suggest that NOD1 is a key player for regulating both ATG16L1 and RIPK2-ULK1 directed autophagy during inflammation in response to iE-DAP in bovine hepatocytes.

Unveiling the immunomodulatory properties of Haemonchus contortus adhesion regulating molecule 1 interacting with goat T cells

Background

Gastrointestinal nematodes could release excretory-secretory (ES) proteins into the host environment to ensure their survival. These ES proteins act as immunomodulators to suppress or subvert the host immune response via the impairment of immune cell functions, especially in chronic infections. In our preliminary study, Haemonchus contortus adhesion-regulating molecule 1 (HcADRM1) was identified from H. contortus ES proteins (HcESPs) that interacted with host T cells via liquid chromatography-tandem mass spectrometry analysis. However, little is known about HcADRM1 as an ES protein which may play a pivotal role at the parasite-host interface.

Methods

Based on bioinformatics approaches, multiple amino acid sequence alignment was conducted and the evolutionary relationship of HcADRM1 with ADRM1 orthologues was extrapolated. Employing RT-qPCR and immunohistochemistry assays, temporal transcriptional and spatial expression profiles of HcADRM1 were investigated. Using immunostaining approaches integrated with immunological bioassays, the immunomodulatory potentials of HcADRM1 on goat T cells were assessed.

Results

We hereby demonstrated that HcADRM1 with immunodiagnostic utility was a mammalian ADRM1 orthologue abundantly expressed at all developmental stages of H. contortus. Given the implications of ADRM1 proteins in cell growth, survival and development, we further investigated the immunomodulatory property of HcADRM1 as an individual ES protein acting at the parasite-host interface. The rHcADRM1 stimuli notably suppressed T cell viability, promoted intrinsic and extrinsic T cell apoptosis, inhibited T cell proliferation and induced cell cycle arrest at G1 phase. Simultaneously, rHcADRM1 stimuli exerted critical controls on T cell cytokine secretion profiles, predominantly by restraining the secretions of interleukin (IL)-4, IL-10 and interferon-gamma.

Conclusions

Importantly, HcADRM1 protein may have prophylactic potential for anti-H. contortus vaccine development. Together, these findings may contribute to the clarification of molecular and immunomodulatory traits of ES proteins, as well as improvement of our understanding of parasite immune evasion mechanism in H. contortus-host biology.

A Novel α/β Hydrolase Domain Protein Derived From Haemonchus contortus Acts at the Parasite-Host Interface

The α/β-hydrolase domain (ABHD) proteins belonging to α/β-hydrolase (ABH) superfamily are ubiquitously distributed throughout all the organisms, and their functional roles have been implicated in energy metabolism, cell signaling, growth and development. In our preliminary work, we identified a novel ABHD protein derived from Haemonchus contortus excretory-secretory (ES) proteins (HcESPs) that interacted with host T cells. Here, we demonstrated that H. contortus ABHD (HcABHD) protein, expressed in all life-cycle stages of H. contortus, is a mammalian ABHD17 homolog with immunodiagnostic utility and lipase activity. Given its catalytic activities and immunomodulatory potentials, we further investigated the functional diversity of HcABHD as an individual ES protein in parasite-host interactions. HcABHD protein may serve as depalmitoylase or thioesterase to suppress cell viability, inhibit cell proliferation, induce intrinsic and extrinsic T cell apoptosis, and cause cell cycle arrested at G1 phase. Moreover, recombinant HcABHD stimuli exerted critical controls on T cell cytokine production profiles, predominantly by inhibiting the secretions of interleukin (IL)-4, interferon-gamma (IFN-γ) and transforming growth factor-beta (TGF-β) 1, and promoting IL-10 production. As the immunomodulator acting at the parasite-host interface, HcABHD protein may have potential applications for the vaccine development of therapeutic intervention. Together, these findings may help illuminate the molecular and particularly immunomodulatory aspects of ES proteins and contribute to an enhanced understanding of parasite immune evasion in H. contortus-host biology.

High-Concentrate Feeding to Dairy Cows Induces Apoptosis via the NOD1/Caspase-8 Pathway in Mammary Epithelial Cells

(1) Background: The effects of a high-concentrate (HC) diet in inducing mammary epithelial cell apoptosis in dairy cows via the NOD1/Caspase-8 pathway have never been investigated before the current study. (2) Methods: Twelve Holstein Frisian cows at mid-lactation were selected to conduct this research. The animals were randomly allocated to two groups (n = 6), and both groups received one of two diets: a low-concentrate (LC) (forage: concentrate 6:4) or a high-concentrate (HC) (forage: concentrate 4:6) diet. Furthermore, an enzyme activity assay, tunnel cell assay, RT-qPCR, western blotting, and an immunofluorescence antibody (IFA) assay were performed to elucidate the effect of an HC diet in the mammary gland of dairy cows. (3) Results: The tunnel cell assay revealed a significant number of apoptotic cells in HC group, and the concentration of Caspase-3, and Caspase-8 was higher in the HC group than in the LC group. NOD1, Rip-2, Caspase-3, Caspase-8, Caspase-9, and Bax mRNA expressions, and NOD1, Caspase-3, Caspase-8, and Bax protein expressions, in the HC group were markedly higher than those in the LC group. Furthermore, Bcl-2 mRNA and protein expressions were markedly decreased in the HC compared to those in the LC group. (4) Conclusions: A HC diet fed to dairy cows incites subacute ruminal acidosis (SARA), which increases the iE-DAP concentration and induces apoptosis in the mammary gland via the NOD1/Caspase-8 pathway.

Sodium butyrate suppresses NOD1-mediated inflammatory molecules expressed in bovine hepatocytes during iE-DAP and LPS treatment

Nucleotide oligomerization domain protein-1 (NOD1), a cytosolic pattern recognition receptor for the γ-D-glutamyl-meso-diaminopimelic acid (iE-DAP) is associated with the inflammatory diseases. Very little is known how bovine hepatocytes respond to specific ligands of NOD1 and sodium butyrate (SB). Therefore, the aim of our study was to investigate the role of bovine hepatocytes in NOD1-mediated inflammation during iE-DAP or LPS treatment or SB pretreatment. To achieve this aim, hepatocytes separated from cows at ∼160 days in milk (DIM) were divided into six groups: The nontreated control group (CON), the iE-DAP-treated group (DAP), the lipopolysaccharide-treated group (LPS), iE-DAP with SB group (DSB), LPS with SB group (LSB), and the SB group. Both iE-DAP and LPS highly increased the expression of both NOD1 and RIPK2, the two key factors for the immune response in hepatocytes. IκBα, NF-κB/p65, and MAP kinases (ERK, JNK, and p38) were activated through phosphorylation. The activation of NF-κB and MAPK pathway consequently increased the proinflammatory cytokines, IL-6, TNF-α, IL-8, and IFN-γ and the chemokines CCL5, CCL20, and CXCL-10. Both treatments improved iNOS/NOS2 expression. However, iE-DAP was failed to express acute phase protein SAA3, but HP and LPS HP but SAA3. These ligands also increased LRRK2, TAK1, TAB1, and β-defensins expression. The SB pretreatment at lower dose restored the function of hepatocytes by suppressing these increased molecules, as HDAC3 was inhibited. The activated NOD1 negatively regulated the expression of FOXA2. Altogether these data suggest an important role of bovine hepatocytes to promote immune responses via NOD1 expression during infection in the liver and a key role of SB to attenuate inflammation.

Overfeeding with a high-concentrate diet activates the NOD1-NF-κB signalling pathway in the mammary gland of mid-lactating dairy cows

Long term high-concentrate (HC) diet feeding induces subacute ruminal acidosis (SARA), which is reported to trigger a pro-inflammatory response. This study aimed to investigate the role of nucleotide-binding oligomerization domain protein 1 (NOD1) in initiating the pro-inflammatory response triggered by grain-induced SARA in the mammary gland of mid-lactating dairy cows. Twelve multiparous mid-lactating Holstein cows (455 ± 28 kg) were randomly assigned into two groups to conduct the experiment for 18 weeks as follows: one group was fed a low-concentrate (LC) diet as a control (40% grain), and the other was fed an HC diet as a treatment (60% grain). Overall, the results showed that a decreased rumen pH and elevated γ-D-glutamyl-meso-diaminopimelic acid (iE-DAP) concentrations in the HC group compared with LC group. The concentration of pro-inflammatory cytokines, including interleukin (IL)-1β, IL-6 and tumour necrosis factor-alpha (TNF-α), significantly increased in the lacteal vein of the HC group than LC group. The mRNA expression levels of NOD1, receptor-interacting protein2 (RIP2), NF-κBp65 (p65), IL-1β, IL-6, IL-8 and TNF-α, which involved in inflammatory response, were up-regulated in the HC-induced mammary gland. The changes of the target proteins, including NOD1, p65 and pp65 presented the same tendency as those of the target genes. Collectively, long-term high concentrate feeding-induced SARA increased the rumen iE-DAP concentration which activated NOD1-NF-κB signalling pathway-dependent inflammation in the mammary gland of mid-lactating cows.