Recombinant Fusion Protein Vaccine Containing Clostridioides difficile FliC and FliD Protects Mice against C. difficile Infection.

Bacterial flagella are involved in infection through their roles in host cell adhesion, cell invasion, auto-agglutination, colonization, the formation of biofilms, and the regulation and secretion of nonflagellar bacterial proteins that are involved in the virulence process. In this study, we constructed a fusion protein vaccine (FliCD) containing the Clostridioides difficile flagellar proteins FliC and FliD. The immunization of mice with FliCD induced potent IgG and IgA antibody responses against FliCD, protected mice against C. difficile infection (CDI), and decreased the C. difficile spore and toxin levels in the feces after infection. Additionally, the anti-FliCD serum inhibited the binding of C. difficile vegetative cells to HCT8 cells. These results suggest that FliCD may represent an effective vaccine candidate against CDI.

Development of a droplet digital PCR assay to detect bovine alphaherpesvirus 1 in bovine semen.

BACKGROUND: Infectious bovine rhinotracheitis (IBR) caused by bovine alphaherpesvirus 1 (BoHV-1) is one of the most important contagious diseases in bovine. This is one of the most common infectious disease of cattle. This has led to high economic losses in the cattle farming industry. BoHV-1 can potentially be transmitted via semen during natural or artificial insemination (AI). Therefore, testing methods for the early diagnosis of BoHV-1 infection are urgently needed for international trade of ruminant semen. In this study, we developed a novel droplet digital PCR (ddPCR) assay for the detection of BoHV-1 DNA in semen samples. RESULTS: The ddPCR results showed that the detection limit was 4.45 copies per reaction with high reproducibility. The established method was highly specific for BoHV-1 and did not show cross-reactivity with specify the organisms (BTV, BVDV, Brucella, M . bovis). The results of clinical sample testing showed that the positivity rate of ddPCR (87.8%) was higher than that of qPCR (84.1%). CONCLUSIONS: The ddPCR assay showed good accuracy for mixed samples and could be a new added diagnostic tool for detecting BoHV-1.

Overexpression of heat shock protein 70 induces apoptosis of intestinal epithelial cells in heat-stressed pigs: A proteomics approach.

Heat stress (HS)-induced intestinal epithelial cell apoptosis may play a pivotal role in intestinal barrier dysfunction in animals. However, the underlying molecular mechanism by which HS induces apoptosis in intestinal epithelial cells is still poorly understood. Herein, a eukaryotic expression vector for an HSP70 gene was constructed and transfected into intestinal porcine epithelial cells (IPEC-J2). Afterward, functional proteomics approaches followed by liquid-chromatography-tandem mass spectrometry (LC-MS/MS) were used to identify interacting proteins. Analysis of HSP70 transfected IPEC-J2 cells revealed 246 differentially expressed proteins (DEPs), and functional annotation indicated that most DEPs were primarily related to ECM-receptor interaction, focal adhesion, and apoptosis. Furtherly, the apoptosis rate and expression levels of apoptosis-related proteins in HSP70 transfected IPEC-J2 cells were detected, we found that the expression of caspase-3, PARP, and Bax were increased, but Bcl-2 were decreased in transfected cells. Lastly, an in vitro and in vivo heat stress model were established to explore the role of HSP70 in intestinal epithelia cell apoptosis. The results of in vitrol study showed that HS-induced cellular apoptosis and increases of caspase-3, PARP, and Bax, but decreased of Bcl-2 in IPEC-J2 cells. In vivo study, the cell apoptosis were induced significantly in the duodenum, cecum, and colon of heat stressed pigs, and upregulation of HSP70 was also detected in colon tissues. Therefore, it has been shown that HSP70 plays a crucial role in heat stress-induced apoptosis and may provide new insights into the molecular mechanisms of epithelial cell apoptosis induced by heat stress in pigs.

Effect of heat stress on growth and production performance of livestock and poultry: Mechanism to prevention.

Heat stress is a widespread phenomenon in domestic animal feeding in tropical and sub-tropical areas that are subjected to a growing negative effect in livestock and poultry due to global warming. It leads to reduced food intake, retarded growth, intestinal disequilibrium, lower reproductive performance, immunity and endocrine disorders in livestock and poultry. Many studies show that the pathogenesis of heat stress is mainly related to oxidative stress, hormone secretion disorder, cytokine imbalance, cell apoptosis, cell autophagy, and abnormal cell function. Its mechanism refers to activation of mitogen-activated protein kinase (MAPK) signaling pathway and nuclear factor kappa B (NF-κB) signaling pathway, the fluctuation of tight junction protein and heat shock protein expression, and protein epigenetic modification. This manuscript reviews the mechanism of heat stress through an insight into the digestive, reproductive, immune, and endocrine system. Lastly, the progress in prevention and control techniques of heat stress has been summarized.

ERK1/2 mitogen-activated protein kinase mediates downregulation of intestinal tight junction proteins in heat stress-induced IBD model in pig.

In many mammalian species, including pigs, heat stress (HS) detrimentally leads to epithelium damage and increases intestinal permeability. However, the underlying molecular mechanisms are not thoroughly investigated yet. This study aimed to examine the RIP1/RIP3-ERK1/2 signaling pathway that regulates the expression of tight junction proteins in HS-treated pigs. In in vitro cultured intestinal porcine epithelial cells (IPEC-J2), HS induced the expression of tight junction proteins, ZO-1, claudin-1, and claudin-4, that are regulated by the ERK1/2-MAPK signaling pathway. Further, high expression of HSP70 in IPEC-J2 cells induced a significant decrease in receptor-interacting protein 1/3 (RIP1/3), phosphorylated ERK, and tight junction protein claudin-1 (P < 0.05). Necrostatin-1 (A selective inhibitor of RIPK1) suppressed the upregulation of phosphorylated ERK1/2 induced by HS, indicating that the RIP1/RIP3 regulates ERK1/2 phosphorylation in IPEC-J2 under heat stress. In addition, HS significantly damaged the intestinal morphology characterized by reduction of villus length and crypt depth in in vivo porcine model. Moreover, the expression of tight junction, ZO-1, and claudin-4 were downregulated, whereas phosphorylated p38 and ERK1/2 were upregulated in the duodenum of heat-stressed pigs. Interestingly, a decrease in ZO-1 and claudin-1 was observed in the colon, where phosphorylated ERK1/2 was similar to that in the duodenum. Our results demonstrate that RIP1/RIP3-ERK1/2 signaling pathway regulates the expression of tight junction proteins in HS-pigs. This finding further advances the intestinal barrier function's underlying mechanisms associated with signaling regulation.

Dynamics of apoptosis-related gene expression during follicular development in yak.

The potential reproduction power of domestic animals is limited by a complicated follicular atresia process. P53, caspase-9 (Casp9), Bax, Bcl-2 and Fas play a crucial role in the ovarian mitochondrion-dependent apoptosis and death receptor pathway. In accordance with this study, the expression levels of Casp9, Bax, Bcl-2 and Fas were analysed in ovaries and oviducts of yak by immunohistochemistry (IHC). P53 and the above in ovarian granulosa cells (GCs) from atretic (3-6 mm) to healthy follicles (6-8 mm) and in oviducts were examined from the luteal phase to the follicular phase during the oestrous circle by Western blot (WB) and real-time PCR (RT-PCR). Results demonstrated that typical classic apoptotic factors Casp9, Bax, Bcl-2 and Fas were expressed in the cytoplasm and zonal pellucida of oocytes, primordial follicles, primary follicles, ovarian surface epithelium, ovarian GCs, granular lutein cells, surface epithelia in oviduct uterotubal junction and oviduct ampulla during the luteal phase. RT-PCR and WB revealed that P53 and Fas significantly increased in GCs of atretic follicles. P53 and Casp9 increased in oviduct epithelium during the luteal phase, but Fas was unchanged. A contrary tendency was noted in Bcl-2 and Bax expression. Overall, P53 and Fas play an essential role in inducing GC apoptosis, and Bax, Bcl-2, Casp9 and P53 are involved in oviduct epithelial regeneration in yak.

Proteomic study of hypothalamus in pigs exposed to heat stress.

BACKGROUND: With evidence of warming climates, it is important to understand the effects of heat stress in farm animals in order to minimize production losses. Studying the changes in the brain proteome induced by heat stress may aid in understanding how heat stress affects brain function. The hypothalamus is a critical region in the brain that controls the pituitary gland, which is responsible for the secretion of several important hormones. In this study, we examined the hypothalamic protein profile of 10 pigs (15 ± 1 kg body weight), with five subjected to heat stress (35 ± 1 °C; relative humidity = 90%) and five acting as controls (28 ± 3 °C; RH = 90%). RESULT: The isobaric tags for relative and absolute quantification (iTRAQ) analysis of the hypothalamus identified 1710 peptides corresponding to 360 proteins, including 295 differentially expressed proteins (DEPs), 148 of which were up-regulated and 147 down-regulated, in heat-stressed animals. The Ingenuity Pathway Analysis (IPA) software predicted 30 canonical pathways, four functional groups, and four regulatory networks of interest. The DEPs were mainly concentrated in the cytoskeleton of the pig hypothalamus during heat stress. CONCLUSIONS: In this study, heat stress significantly increased the body temperature and reduced daily gain of body weight in pigs. Furthermore, we identified 295 differentially expressed proteins, 147 of which were down-regulated and 148 up-regulated in hypothalamus of heat stressed pigs. The IPA showed that the DEPs identified in the study are involved in cell death and survival, cellular assembly and organization, and cellular function and maintenance, in relation to neurological disease, metabolic disease, immunological disease, inflammatory disease, and inflammatory response. We hypothesize that a malfunction of the hypothalamus may destroy the host physical and immune function, resulting in decreased growth performance and immunosuppression in heat stressed pigs.

Magnetic molecularly imprinted specific solid-phase extraction for determination of dihydroquercetin from Larix griffithiana using HPLC.

The naturally occurring quercetin flavonoid, dihydroquercetin, is widely distributed in plant tissues and has a variety of biological activities. Herein, a magnetic molecularly imprinted solid-phase extraction was tailor made for selective determination of dihydroquercetin in Larix griffithiana using high-performance liquid chromatography. Amino-functionalized core-shell magnetic nanoparticles were prepared and characterized using scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, and infrared spectroscopy. The polymer had an average diameter of 250 ± 2.56 nm and exhibited good stability and adsorption for template molecule, which is enriched by hydrogen bonding interaction. Multiple factors for extraction, including loading, washing, elution solvents, and extraction time, were optimized. The limit of detection was 1.23 µg/g. The precision determined at various concentration of dihydroquercetin was less than 4% and the mean recovery was between 74.64 and 101.80%. It has therefore been shown that this protocol can be used as an alternative extraction to quantify dihydroquercetin in L. griffithiana and purify quercetin flavonoid from other complex matrices.

SOCS3 control the activity of NF-κB induced by HSP70 via degradation of MyD88-adapter-like protein (Mal) in IPEC-J2 cells.

Hyperthermia in pigs induces suppressor of cytokine signaling (SOCS) 3 and SOCS4 expression in intestinal gut and causes disruption of inflammation cytokine production. These changes may affect the development of inflammatory bowel disease in heat-stressed pigs. However, the mechanisms are not well understood. Accordingly, in this study, we examined the roles of SOCS members in regulation of the nuclear factor (NF)-κB pathway and heat shock protein (HSP) 70-mediated cytokine induction in 293T human embryonic kidney cells and IPEC-J2 porcine small intestinal epithelial cells. Ectopic expression of HSP70 significantly modulated NF-κB activity (p ≤ .05). Moreover, co-expression of SOCS3 or SOCS4 with HSP70 reduced NF-κB activity, which was abolished by SOCS3 or SOCS4 knockdown with short hairpin RNA. Interestingly, MyD88-adaptor-like (Mal) protein was downregulated in cells expressing SOCS3 but not in cells expressing SOCS4. In addition, SOCS3 but not SOCS4 negatively regulated the activity of NF-κB induced by HSP70 overexpression via degradation of Mal. These findings may facilitate the development of novel SOCS3-based therapeutic strategies to control heat stress-related disorders in pigs.

Oral Immunization with Nontoxigenic Clostridium difficile Strains Expressing Chimeric Fragments of TcdA and TcdB Elicits Protective Immunity against C. difficile Infection in Both Mice and Hamsters.

The symptoms of Clostridium difficile infection (CDI) are attributed largely to two C. difficile toxins, TcdA and TcdB. Significant efforts have been devoted to developing vaccines targeting both toxins through parenteral immunization routes. However, C. difficile is an enteric pathogen, and mucosal/oral immunization would be particularly useful to protect the host against CDI, considering that the gut is the main site of disease onset and progression. Moreover, vaccines directed only against toxins do not target the cells and spores that transmit the disease. Previously, we constructed a chimeric vaccine candidate, mTcd138, comprised of the glucosyltransferase and cysteine proteinase domains of TcdB and the receptor binding domain of TcdA. In this study, to develop an oral vaccine that can target both C. difficile toxins and colonization/adhesion factors, we expressed mTcd138 in a nontoxigenic C. difficile (NTCD) strain, resulting in strain NTCD_mTcd138. Oral immunization with spores of NTCD_mTcd138 provided mice full protection against infection with a hypervirulent C. difficile strain, UK6 (ribotype 027). The protective strength and efficacy of NTCD_mTcd138 were further evaluated in the acute CDI hamster model. Oral immunization with spores of NTCD_mTcd138 also provided hamsters significant protection against infection with 2 × 104 UK6 spores, a dose 200-fold higher than the lethal dose of UK6 in hamsters. These results imply that the genetically modified, nontoxigenic C. difficile strain expressing mTcd138 may represent a novel mucosal vaccine candidate against CDI.

Histopathological changes in zebrafish embryos exposed to DLPCBs extract from Zhanjiang coastal sediment.

Dioxin-like polychlorinated biphenyls (DLPCBs) are ubiquitous persistent pollutants that cause adverse effects in many environmental organisms. DLPCBs in marine sediments can be absorbed by benthic organisms, bioaccumulate, and biomagnify through the food chain and threaten animal and human health. There are no reports of DLPCBs concentrations in the Zhanjiang Gulf seabed. This study was designed to investigate the concentration of DLPCBs in the Zhanjiang coastal sediment and histopathological changes in zebrafish (Diano rerio) embryos exposed to environmentally relevant concentrations of DLPCBs. Of the five sites selected, two sites TS and JSW contained DLPCBs at concentrations of 0.08 and 22.54 ng/g dry sediment, respectively. Two groups of zebrafish embryos were used. One group was exposed to 3.75, 7.5, 15, 30, and 60 mg/ml of DLPCBs extracted from the sediments sampled from the TS site and the second group to 4.375, 8.75, 17.5, 35, and 70 mg/ml of DLPCBs from JSW site from 0.75 h post-fertilization (hpf) to 96 hpf. The zebrafish exposed to 60 and 70 mg/ml of DLPCBs at 96 hpf displayed gross histopathological changes with cardiac lesions including pericardial edema being the most deleterious. Other changes observed were hydropic degeneration of gill filaments and hepatocytes, loss of intestinal folds, and uninflated swim bladder. It appears that only a few sites of the Zhanjiang gulf are contaminated with DLPCBs. This is the first report of histopathological changes in the gills, hepatocytes, intestines, heart, and the swim bladder in zebrafish embryos exposed to DLPCBs from a coastal sediment. Further studies with sampling at different stages of development are required to identify which organ/tissue is most sensitive to DLPCBs.

Developmental toxicity, oxidative stress, and related gene expression induced by dioxin-like PCB 126 in zebrafish (Danio rerio).

3,3',4,4',5-Pentachlorobiphenyl (PCB126) cause multiple adverse effects in organisms including animals and humans. Although PCB toxicities are linked to oxidative damage in rodents, the mechanism in early life stages of zebrafish is not clear. To explore the developmental toxicity mechanism of PCB126, three paradigms (toxicological phenotypes, biochemical changes, and molecular changes) were studied in 3-h postfertilization (hpf) zebrafish (Danio rerio) embryos exposed to different PCB126 concentrations (0, 16, 32, 64, and 128 µg/L) until 168 hpf. Developmental malformations, including pericardial and yolk sac edema, impaired lower jaw growth, spinal curvature, head edema and failure to inflate the swim bladder were observed, some as early as 72 hpf. Mortality was not apparent in early stages but significantly increased in a dose-dependent manner from 144 hpf onward. A dose-dependent significant increase in malformation rate was observed from 72 hpf onward with up to 100% at 132 hpf in embryos exposed to 128 µg/L of PCB126. Higher doses of PCB126 significantly decreased the copper-zinc superoxide dismutase (CuZn-Sod), catalase (Cat), and glutathione peroxidase (Gpx) enzyme activities at 96, 132 hpf, but markedly declined from thereafter. PCB126 at 128 µg/L significantly increased the malondialdehyde content at 72, 96, and 132 hpf. The transcriptional gene expression of antioxidant enzymes Cat and Gpx was upregulated in embryos exposed to 64 µg/L of PCB126 at 24 and 96 hpf. Sod1 messenger RNA (mRNA) was low in embryos exposed to 32 µg/L at 72 and 96 hpf but was induced in embryos exposed to 64 and 128 µg/L doses at 132 hpf. Collectively, the results suggest oxidative stress as a major factor in the induction of multiple developmental abnormalities in early life stages of zebrafish exposed to PCB126. However, the relationship between the antioxidant enzyme activity and the mRNA expression was not clear and the potential reasons for this are discussed.

Developmental toxicity, EROD, and CYP1A mRNA expression in zebrafish embryos exposed to dioxin-like PCB126.

Dioxin-like PCB126 is a persistent organic pollutant that causes a range of syndromes including developmental toxicity. Dioxins have a high affinity for aryl hydrocarbon receptor (AhR) and induce cytochrome P4501A (CYP1A). However, the role of CYP1A activity in developmental toxicity is less clear. To better understand dioxin induced developmental toxicity, we exposed zebrafish (Danio rerio) embryos to PCB126 at concentrations of 0, 16, 32, 64, and 128 µg L(-1) from 3-h post-fertilization (hpf) to 168 hpf. The embryonic survival rate decreased at 144 and 168 hpf. The fry at 96 hpf displayed gross developmental malformations, including pericardial and yolk sac edema, spinal curvature, abnormal lower jaw growth, and non-inflated swim bladder. The pericardial and yolk sac edema rate significantly increased and the heart rate declined from 96 hpf compared with the controls. PCB126 did not alter the hatching rate. To elucidate the mechanism of PCB126-induced developmental toxicity, we conducted ethoxyresorufin-O-deethylase (EROD) in vivo assay to determine CYP1A enzyme activity, and real-time PCR to study the induction of CYP1A mRNA gene expression in embryo/larval zebrafish at 24, 72, 96, and 132 hpf. In vivo EROD activity was induced by PCB126 at 16 µg L(-1) concentration as early as 72 hpf but significant increases were observed only in zebrafish exposed to 64 and 128 µg L(-1) doses (p < 0.005) at 72, 96, and 132 hpf. Induction of CYP1A mRNA expression was significantly upregulated in zebrafish exposed to 32 and 64 µg L(-1) at 24, 72, 96, and 132 hpf. Overall, the severe pericardial and yolk sac edema and reduced heart rate suggest that heart defects are a sensitive endpoint, and the general trend of dose-dependent increase in EROD activity and induction of CYP1A mRNA gene expression provide evidence that the developmental toxicity of PCB126 to zebrafish embryos is mediated by activation of AhR.

Identification and functional characterization of Toll-like receptor 2-1 in geese.

BACKGROUND: Toll-like receptor 2 (TLR2), an important pattern recognition receptor, activates proinflammatory pathways in response to various pathogens. It has been reported in humans and chicken, but not in geese, an important waterfowl species in China. Since some vaccines stimulate robust immune responsesl in chicken but not in geeeses we speculated that their immune systems are different. RESULTS: In this study, we cloned the goose TLR2-1 gene using rapid amplification of cDNA ends (RACE)and showed that geese TLR2-1 encoded a 793-amino-acid protein, containing a signal secretion peptide, an extracellular leucine-rich repeat domain, a transmembrane domain and a Toll/interleukin-1 receptor signaling domain deduced from amino acid sequence. TLR2-1 shared 38.4%-93.5% homology with its homologues in other species. Tissue expression of geese TLR2-1 varied markedly, and was higher in kidney, cloacal bursa, skin and brain compared to other organs/tissues. HEK293 cells transfected with plasmids carrying goose TLR2-1 and NF-κB-luciferase responded significantly to stimulation with Mycoplasma fermentans lipopeptide. Furthermore, geese infected with Mycoplasma gallisepticum (MG) and Salmonella enteritidis (SE) showed significant upregulation of TLR2-1 in both in vivo and in vitro. CONCLUSION: Geese TLR2-1 is a functional homologue of TLR2 present in other species and plays an important role in bacterial recognition in geese.

Effects of Heat Stress on Goat Production and Mitigating Strategies: A Review.

Goats, versatile creatures selectively bred for various purposes, have become pivotal in shaping the socioeconomic landscape, particularly in rural and economically challenged areas. Their remarkable ability to withstand and adapt to extreme heat has proven invaluable, allowing them to flourish and reproduce in even the harshest climates on Earth. Goat farming has emerged as a reliable and sustainable solution for securing food resources. However, despite its significance, the goat-producing industry has received less attention than other ruminants. Despite goats' inherent resilience to heat, their productivity and reproductive performance suffer under high ambient temperatures, leading to heat stress. This presents a significant challenge for goat production, necessitating a comprehensive multidisciplinary approach to mitigating the adverse effects of heat stress. This review aims to explore the diverse impacts of heat stress on goats and propose effective measures to address the sector's challenges. By understanding and addressing these issues, we can enhance the resilience and sustainability of goat farming, ensuring its continued contribution to food security and socioeconomic development.

The Identification of RPL4 as a Hub Gene Associated with Goat Litter Size via Weighted Gene Co-Expression Network Analysis.

Reproduction in goats is a highly complex and dynamic process of life regulation, involving coordinated regulation from various aspects such as central nervous system regulation, reproductive system development, oocyte maturation, and fertilized egg development. In recent years, researchers have identified numerous genes associated with goat reproductive performance through high-throughput sequencing, single-cell sequencing, gene knockout, and other techniques. However, there is still an urgent need to explore marker genes related to goat reproductive performance. In this study, a single-cell RNA sequencing dataset of oocytes (GSE136005) was obtained from the Gene Expression Omnibus (GEO) database. Weighted Gene Co-expression Network Analysis (WGCNA) was utilized to identify modules highly correlated with goat litter size. Through gene function enrichment analysis, it was found that genes within the modules were mainly enriched in adhesive junctions, cell cycle, and other signaling pathways. Additionally, the top 30 hub genes with the highest connectivity in WGCNA were identified. Subsequently, using Protein-Protein Interaction (PPI) network analysis, the top 30 genes with the highest connectivity within the modules were identified. The intersection of hub genes, key genes in the PPI network, and differentially expressed genes (DEGs) led to the identification of the RPL4 gene as a key marker gene associated with reproductive capacity in goat oocytes. Overall, our study reveals that the RPL4 gene in oocytes holds promise as a biological marker for assessing goat litter size, deepening our understanding of the regulatory mechanisms underlying goat reproductive performance.

Protective Effects of Carbonated Chitosan Montmorillonite on Vomitoxin-Induced Intestinal Inflammation.

Exposure to vomitoxin (DON) can negatively impact the intestinal health of livestock and poultry, leading to compromised nutrient absorption and utilization, resulting in slowed growth and reduced production efficiency. In this study, we synthesized carbonated chitosan montmorillonite intercalation complexes (CCM) through solution precipitation. The successful formation of intercalation complexes was confirmed by examining functional groups and surface features using infrared spectroscopy and scanning electron microscopy. To assess the impact of CCM on DON-infected mice, we established an experimental mouse model of jejunal inflammation induced by DON infection. We analyzed the effects of CCM on blood biochemical and conventional indices, jejunal inflammatory factors, pathological changes, and the expression of proteins in the MAPK pathways in DON-infected mice. Our results indicate that CCM effectively mitigates the adverse effects of DON on growth performance, jejunal injury, and the inflammatory response in mice. CCM supplementation alleviated the negative effects of DON infection on growth performance and reduced intestinal inflammation in mice. Moreover, CCM supplementation successfully inhibited the activation of the mitogen-activated protein kinase (MAPK) signaling pathway induced by DON. These findings suggest that the mitigating effect of CCM on DON-induced inflammatory injury in the murine jejunum is closely linked to the regulation of the MAPK signaling pathway.

Preliminary Proteomic Study of the Porcine Pituitary Gland under Heat Stress.

Although numerous studies have shown that the hypothalamic-pituitary-adrenal axis plays a vital role in the response to environmental stress by mediating the production of a series of hormones, the mechanism underlying these effects has not been elucidated. This study used proteomics techniques to investigate the differentially expressed proteins (DEPs) in the pituitary glands of pigs and to elucidate the potential changes in the immune-neuroendocrine system under heat stress (HS). In total, 2517 peptides corresponding to 205 proteins were detected. A comparison of the expression patterns between HSs and healthy controls revealed 56 DEPs, of which 31 were upregulated and 25 were downregulated. Ingenuity pathway analysis (IPA) was used to reveal the subcellular characteristics, functional pathways, regulatory networks, and upstream regulators of the identified proteins. The results showed that these differentially expressed proteins were involved in intercellular communication, interactions, apoptosis, nervous system development, functions, abnormalities and other functions, and in the regulatory network. Moreover, the upstream regulators of the differentially expressed proteins were mainly transcriptional regulators, hormones, and cytokines. Thus, the functional network and pathway analyses could provide insights into the complexity and dynamics of HS-host interactions and may accelerate our understanding of the mechanisms underlying HS.

Enhancing gut barrier integrity: Upregulation of tight junction proteins by chitosan oligosaccharide through the ERK1/2 signaling pathway.

OBJECTIVES: This study aimed to explore the protective mechanism of chitosan oligosaccharide (COS) against lipopolysaccharide (LPS)-induced inflammatory responses in IEC-6 cells and dextran sodium sulfate (DSS)-induced colitis in mice. METHODS: The cell inflammation model was constructed by LPS in vitro and enteritis model by DSS in vivo. RESULTS: Following LPS exposure, IEC-6 cell proliferation significantly decreased, epithelial cell integrity was compromised, and TNF-α and IL-1ß levels were increased. However, COS pretreatment reversed these changes. In vivo, DSS-treated mice exhibited evident pathological alterations, including heightened inflammatory levels and significantly decreased expression of tight junction proteins and critical proteins in the Mitogen activated proteins kinase signaling pathway. Nevertheless, COS administration notably reduced inflammatory levels and increased the expression of tight junction proteins and key proteins in the Mitogen activated proteins kinase signaling pathway. CONCLUSIONS: Our findings suggest that COS safeguards gut barrier integrity by upregulating tight junction proteins through the ERK1/2 signaling pathway. Therefore, COS has emerged as a promising candidate for novel drug interventions against inflammatory bowel disease.

Base composition, adaptation, and evolution of goose astroviruses: codon-based investigation.

Goose astroviruses (GoAstVs) are causative agents that account for fatal infection of goslings characterized by visceral urate deposition, resulting in severe economic losses in major goose-producing regions in China since 2017. In this study, we sought to unravel the intrinsic properties associated with adaptation and evolution in the host environment of GoAstVs. Consistent results from phylogenetic analysis and correspondence analysis performed on the codon usage patterns (CUPs) reveal 2 clusters of GoAstVs, namely, GoAstV-1 and GoAstV-2. However, multiple similar compositional characteristics were found, despite the high divergence between GoAstV-1 and GoAstV-2. Studies on the base composition of GoAstVs reveal an A/U bias, indicating a compositional constraint, while natural selection prevailed in determining the CUPs in the virus genome based on our neutrality plot analysis, reflecting high adaptive pressure to fit the host environment. Codon adaptation index (CAI) analysis revealed a higher degree of fitness to the CUPs of the corresponding host for GoAstVs than avian influenza virus and betacoronaviruses, which may be a favorable factor contributing to the high pathogenicity and wide distribution of GoAstVs in goslings. In addition, GoAstVs were less adapted to ducks and chickens, with significantly lower CAI values than to geese, which may be a reason for the different prevalence of GoAstVs among these species. Extensive investigations on dinucleotide distribution revealed a significant suppression of the CpG and UpA motifs in the virus genome, which may facilitate adaptation to the host's innate immune system by evading surveillance. In addition, our study reported the trends of increasing fitness to the host's microenvironment for GoAstVs through increasing adaptation to host CUPs and ongoing reduction of CpG motifs in the virus genome. The present analysis deepens our understanding of the basic biology, pathogenesis, adaptation and evolutionary pattern of GoAstVs, and contributes to the development of novel antiviral strategies.