Hexavalent chromium [Cr(VI)] is a widespread environmental contaminant known to cause severe organ damage, with acute exposure leading to significant nephrotoxicity. To elucidate the underlying mechanisms, this study investigated the role of the mitophagy-ferroptosis axis in Cr(VI)-induced renal injury using mouse models and renal tubular epithelial cells (mRTECs). We found that Cr(VI) exposure disrupted mitochondrial iron homeostasis in mRTECs, leading to Mito-Fe2+ accumulation and mitochondrial damage. Consequently, this triggered an overproduction of mitochondrial and total reactive oxygen species (Mito-ROS/total ROS) and initiated lipid peroxidation. Furthermore, our mechanistic studies revealed that Cr(VI) induced FUNDC1-dependent mitophagy, which specifically targeted the degradation of SLC7A11. This event downregulated GPX4 and impaired the glutathione antioxidant system, thereby exacerbating lipid peroxidation and ultimately driving ferroptosis. In vivo studies corroborated these findings, demonstrating evident renal injury in Cr(VI)-exposed mouse. Collectively, Our data reveal a novel mechanism whereby FUNDC1-mediated mitophagy participates in hexavalent Cr(VI)-induced renal ferroptosis through degradation of SLC7A11. These results not only clarify a key pathological pathway but also highlight the therapeutic potential of targeting the SLC7A11-FUNDC1 axis to mitigate Cr(VI) nephrotoxicity.

RESEARCH HIGHLIGHTS:The co-infection rate of infectious tumour disease in chickens is 37% in China.The incidence rate is the highest in Dezhou City.

Luteolin, a naturally occurring flavonoid abundantly found in various fruits and vegetables, possesses anti-inflammatory and antioxidant properties. Its biological activities, including modulating immune responses and alleviating oxidative stress, make it a promising therapeutic candidate for inflammatory diseases. However, the precise role of this compound in mitigatingEscherichia coli induced (E. coli-induced) intestinal inflammation remains largely unexplored. More specifically, the mechanistic underpinnings by which it preserves intestinal mucosal barrier integrity, fine-tunes the activation dynamics of key mediators in intestinal inflammatory signaling cascades, and orchestrates the intricate crosstalk between intestinal microbiota homeostasis and host immune responses remain poorly elucidated. In this study, a total of 144 three-week-old specific pathogen-free (SPF) chickens were randomly divided into groups. An E. coli-induced enteritis model was subsequently established in these animals. Luteolin was administered at varying doses through the feed for a period of one week. The potential protective effects of luteolin against E. coli-induced intestinal damage were investigated from multiple aspects, including intestinal barriers function, gut microbiota composition, and differential metabolites profiles. Luteolin alleviated intestinal damage, enhanced survival rate and weight gain in chicken (P<0.05) and improved antioxidant capacity by reducing oxidative stress (P<0.05). It repaired intestinal barrier injury by upregulating the mRNA levels of tight junction proteins, and reduced intestinal inflammation by inhibiting the activation of the Toll-like receptor 4 nuclear (TLR4)/Myeloid Differentiation Primary Response Protein 88 (MyD88)/factor-κB (NF-κB) signaling pathway (P<0.05). In addition, luteolin reversed E. coli-induced gut microbiota dysbiosis, increasing the abundance of beneficial microorganisms such as Lachnospiraceae-Clostridium and Butyricimonas. Metabolomics analysis further revealed that luteolin partially corrected E. coli-induced metabolic disorders by modulating nucleotide metabolism (IMP, P<0.05), amino acid biosynthesis(arginine ornithine and lysine, P<0.05), and glutathione metabolism (S - lactoyl glutathione, P<0.05). Notably, a significant association was observed between gut microbiota and metabolic products (P<0.05). In summary, luteolin alleviates E. coli-induced enteritis in chickens via a multi-target mode of action that entails preserving gut microbiota homeostasis, restoring intestinal metabolic signatures, and suppressing the TLR4/MyD88/NF-κB signaling cascade, which offers new perspectives for avian disease management and highlights its prospects as a safe antibiotic substitute.

Although numerous studies have reported the male reproductive toxicity of bisphenol A (BPA) and its substitute bisphenol S (BPS), the impacts of paternal exposure to these chemicals on the male reproductive system of offspring and the underlying molecular mechanism remain inadequately explored. In this study, we investigated male reproductive toxicity in pubertal offspring resulting from paternal exposure to environmentally relevant doses of BPA (0.45 μg/kg body weight [bw]/day) or BPS (0.15 μg/kg bw/day). Our results showed that paternal exposure to BPA or BPS reduced pubertal offspring testosterone levels and impaired testicular histomorphology and development. Concurrently, BPA and BPS decreased the activities of testicular marker enzymes (LDH and SDH), down-regulated the expression of spermatogenesis-related genes (Plzf, Pcna, and Sycp3), and were accompanied by reduced sperm quality and increased malformation rates. Notably, paternal exposure to BPA/BPS suppressed the expression of the key carnitine transporter OCTN2 and disrupted testicular carnitine transport homeostasis in offspring. The consequent reduction in testicular carnitine led to decreased expression of markers involved in mitochondrial β-oxidation (CPT1 and CPT2) and the respiratory chain (ND1, ND2, ND3, CYTB, COX1, and ATP6), resulting in severely impaired energy metabolism. Further investigation revealed that paternal BPA/BPS exposure also inhibited the activities of antioxidant enzymes (CAT, SOD, and GSH-Px) in offspring testes, leading to substantial accumulation of MDA. Elevated oxidative stress promoted intrinsic apoptotic signaling in offspring testes. This was characterized by the upregulation of pro-apoptotic markers, including increased Cleaved-CASPASE-3/9 levels and a higher BAX/BCL2 ratio. In summary, this study demonstrates that paternal BPA/BPS-induced dysregulation of the testicular carnitine transport system and disruption of carnitine homeostasis contribute to impairments in testicular energy metabolism in offspring. Concurrently, it induces oxidative stress and activates the intrinsic apoptotic pathway, collectively contributing to impaired testicular development and spermatogenesis in pubertal offspring.

Staphylococcus aureus (S. aureus) is a Gram-positive bacterium that serves as a major pathogen causing bovine mastitis. One of the key intracellular survival mechanisms of S. aureus involves the induction of autophagy. The capacity of S. aureus to subvert autophagy for intracellular survival and replication is strongly linked to its broad array of virulence determinants, which play pivotal roles in infection establishment and immune evasion. One of these virulence factors is phenol-soluble modulin alpha (PSMα), an amphipathic small peptide that plays a key role in the pathogenesis of S. aureus. Utilizing gene-edited S. aureus strain and bovine mammary epithelial cells (BMECs, MAC-T), this study elucidates the involvement of PSMα in autophagy induction during S. aureus infection. The results demonstrated that PSMα knockout attenuated S. aureus-induced autophagy, weakened the activation of the PI3K/Akt/mTOR pathway, and reduced intracellular bacterial load. Our findings elucidate a PSMα-dependent autophagy induction mechanism in S. aureus infection, which is associated with the intracellular survival of S. aureus.

With increasing industrialization, hexavalent chromium (Cr(VI)) is used in various metal smelting and other industries, which, in turn, causes hexavalent chromium pollution. This study aimed to investigate the characteristics of isolated Bacillus subtilis (B. subtilis) from high-Cr(VI) soils and to evaluate its safety. Genomic and transcriptomic analyses were performed to explore its Cr(VI) response mechanisms, and a mouse model (24 mice) was established to evaluate the safety of the bacterium at different concentrations. Key genetic findings showed that Cr(VI) exposure significantly up-regulated the Spx gene and down-regulated the CtsR gene—two critical transcriptional regulators involved in stress response and development that mediate Cr(VI) tolerance. Pathway analysis revealed that ribosome RNA, redox balance, protein biosynthesis, metabolism, and cysteine biosynthesis play a significant role in bacterial Cr(VI) resistance. In the in vivo experiment, it was observed that the small intestine (SI), liver, and spleen of the mice remained normal without any injuries. Different levels of the F3 isolate demonstrated the ability to resist colonization by digestive juices, as observed in the SI slides. Consequently, B. subtilis can endure high levels of Cr(VI) by regulating redox process genes, which makes it a potential candidate for further research in selecting safe, tolerant, and bio-remedial isolates for Cr(VI) treatment.

Broiler ascites syndrome (BAS), a non-infectious group disease caused by relative hypoxia in broilers, is one of the three most serious nutritional metabolic diseases that jeopardize the chicken industry. At present, traditional Chinese medicine (TCM) is widely used to treat BAS, however, its mechanism of action remains unclear. Therefore, this study aimed to screen a new traditional Chinese medicine compound (NCMC) for the treatment of BAS and to elucidate its therapeutic mechanism through an integrated strategy of data mining, network pharmacology, molecular docking, and animal experiments. To this end, a novel NCMC comprising Poria, Pericarpium Citri Reticulatae, Radix Scutellariae, Radix Astragali, Semen Plantaginis, and Rhizoma Zingiberis Recens was successfully formulated based on data mining analysis. Utilizing network pharmacology, STAT3, SRC, and EGFR were identified as core therapeutic targets for BAS. Gene pathway analysis further suggested that the NCMC might exert its effects by modulating hypoxia response, oxidative stress, and the FOXO signaling pathway. These in silico predictions were subsequently validated by in vivo experiments, which demonstrated that NCMC treatment significantly alleviated systemic inflammation, reduced the ascites heart index, and mitigated lung tissue damage in broilers. Concurrently, it markedly enhanced the activities of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) while decreasing the content of malondialdehyde (MDA) in lung tissue. Ultimately, our integrated research approach revealed that the therapeutic effect of NCMC against BAS is primarily achieved through inhibition of the IL-6/STAT3/FOXO3a signaling pathway activation. This study not only provides a promising candidate drug for the treatment of BAS, but also offers a feasible systems pharmacology paradigm for modern research on traditional Chinese medicine compounds.

INTRODUCTION:Hexavalent Chromium [Cr(VI)], a Group 1 carcinogen designated by the International Agency for Research on Cancer (IARC), is a pervasive environmental pollutant. The kidneys are particularly vulnerable to Cr(VI)-induced damage, and emerging evidence suggests that ferroptosis plays a pivotal role in Cr(VI) toxicity. OBJECTIVES:This study aimed to investigate the role of ferroptosis in Cr(VI)-induced injury of mouse renal tubular epithelial cells (mRTECs), and to delineate the underlying molecular mechanisms. METHODS:The cytotoxicity of Cr(VI) on mRTECs was assessed using CCK-8 assays. A comprehensive approach, including Western blot analysis, immunofluorescence, flow cytometry, gene knockdown, overexpression, and malondialdehyde (MDA) detection, was employed to evaluate ferroptosis-related markers, including protein expression, lipid peroxidation, Fe2+ levels, mitochondrial Fe2+ (Mito-Fe2+) levels, reactive oxygen species (ROS) levels, and mitochondrial damage. The transcriptional regulation of IREB2 by metal regulatory transcription factor 1 (MTF1) was validated using a dual-luciferase reporter assay and site-directed mutagenesis. RESULTS:Cr(VI) exposure induced nuclear translocation of MTF1, which transcriptionally upregulated IREB2 expression. We identified a specific MTF1 binding site (5'-TGCACAC-3') in the IREB2 promoter, and its functional role was confirmed through site-directed mutagenesis and dual-luciferase reporter assays. IREB2 upregulation increased divalent metal transporter 1 (DMT1) expression while decreasing ferritin heavy chain 1 (FTH1) levels, leading to elevated intracellular free Fe2+. The excess Fe2+ was transported into mitochondria, causing mitochondrial damage, increased ROS production, and exacerbated lipid peroxidation, ultimately triggering ferroptosis in mRTECs. CONCLUSION:Our findings reveal a novel MTF1-IREB2-FTH1/DMT1 axis through which Cr(VI) induces ferroptosis in mRTECs by disrupting iron homeostasis, promoting mitochondrial damage, and enhancing lipid peroxidation. This study uncovers a critical molecular mechanism underlying Cr(VI)-induced kidney injury and provides new insights for developing preventive and therapeutic strategies against Cr(VI)-associated public health diseases.

Various studies have shown that the harm of hexavalent chromium (Cr(VI)) to animals covers all aspects of the body, while glucose metabolism disorder is one of its hazard factors. In this study, the possible mechanism underlying Cr(VI) exposure on liver glycometabolism and damage was investigated. A mouse model was established by intragastrical administration of Cr(VI) for 5 days; liver tissues were collected and used to detect liver glycometabolism and balance between autophagy and apoptosis. Expose liver cells to a high dose of Cr(VI) significantly increased the levels of alanine aminotransferase, aspartate aminotransferase, malondialdehyde and reactive oxygen species production, suppressed glutathione peroxidase and superoxide dismutase release, upregulated 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFKFB3) expression, inhibited tp53-induced glycolysis and apoptosis regulator (TIGAR) expression and promoted liver glycometabolism disorder. Moreover, the pathway network of glycometabolism has been analysised, showing that 21 differential metabolites levels were decreased and 6 increased. Carbohydrate metabolism pathways closely related to glycometabolism disorder were significantly enriched after Cr(VI) exposure. TIGAR/PFKFB3 inhibited the interactions between Beclin1/BAX and Bcl-2 via Bcl-2 regulated the balance between autophagy and apoptosis. Overall, Cr(VI) can lead to glycometabolism disorder through TIGAR/PFKFB3 imbalance and result in liver injuries in mice.

Dysregulated activation of the NLRP3 inflammasome is a key driver in the pathogenesis of numerous inflammatory disorders. This study aimed to evaluate the protective effect of Platycodon grandiflorus polysaccharide (PGPSt) against NLRP3-inflammasome-mediated inflammation and elucidate its underlying mechanisms. An in vitro inflammatory model was established in porcine alveolar macrophages (3D4/21) using LPS/ATP co-stimulation. The effects of PGPSt were assessed by measuring inflammasome activation, intracellular reactive oxygen species (ROS) generation, and pro-inflammatory cytokine secretion. Molecular docking, alongside inhibitors (NAC, MCC950) and siRNA targeting NEK7, was employed to probe the involved mechanisms. PGPSt significantly suppressed NLRP3 inflammasome assembly and activation, reduced caspase-1 cleavage, and decreased the maturation and release of IL-1β and IL-18. It exerted its inhibitory effects through dual mechanisms: scavenging intracellular ROS and directly binding to NEK7 and NLRP3 to disrupt their interaction, as supported by molecular docking. The anti-inflammatory effect was diminished upon NEK7 knockdown. In conclusion, PGPSt is an effective natural inhibitor of the NLRP3 inflammasome, functioning through ROS clearance and direct interference with the NLRP3–NEK7 interaction. These findings propose PGPSt as a promising therapeutic candidate and further validate NEK7 as a potential target for treating NLRP3-driven inflammatory diseases.

Hexavalent chromium [Cr(VI)], a widespread environmental toxicant with mutagenic and carcinogenic potential, preferentially accumulates in the kidneys, though its nephrotoxic mechanisms remain incompletely understood. This study demonstrates that Cr(VI) induces ferroptosis, an iron-dependent regulated cell death, in nephrocytes. Cr(VI) exposure resulted in mitochondrial dysfunction, iron overload, depleted glutathione (GSH) and superoxide dismutase (SOD), and elevated malondialdehyde (MDA) and reactive oxygen species (ROS). These changes were accompanied by downregulation of the ferroptosis-related proteins GPX4 and FTH1, upregulation of ACSL4, and reduced cell viability. We further identified the mitochondrial deacetylase SIRT3 as a key negative regulator of this process. Genetic inhibition of SIRT3 exacerbated Cr(VI)-induced ferroptosis. Resveratrol is predicted to directly interact with SIRT3 via molecular docking, and functional cellular/in vivo assays confirm resveratrol triggers SIRT3 upregulation and improves its functional activity, thereby alleviating ferroptotic damage by restoring redox and iron homeostasis. The protective effect of resveratrol was largely abolished upon SIRT3 inhibition, indicating a SIRT3-dependent mechanism. Consistent with cellular findings, resveratrol administration in a murine model of Cr(VI) nephrotoxicity attenuated renal tissue injury, upregulated SIRT3 and GPX4 expression, and mitigated pathological changes. Our results reveal a novel SIRT3-mediated pathway through which resveratrol counteracts Cr(VI)-induced renal ferroptosis, highlighting its potential as a therapeutic agent against heavy metal-induced kidney damage.

Sphinganine (SA), a fundamental sphingolipid whose cytotoxicity remains incompletely characterized, has received less attention compared to other sphingoid bases. Here, we demonstrate that SA predominantly triggers cell death via lysosomal membrane permeabilization (LMP) resulting from pH dysregulation and osmotic imbalance, rather than through direct ROS-mediated mechanisms, although mitochondrial ROS contribute to oxidative stress. SA-induced mitochondrial fragmentation significantly increased hydrogen peroxide levels in both the mitochondrial matrix and intermembrane space (IMS). Strikingly, lysosomes exhibited spatial colocalization with elevated hydrogen peroxide microdomains under SA exposure, suggesting a redox-dependent mechanism governing organelle repositioning. The cysteine protease inhibitor E64D attenuated SA-induced apoptosis through suppressing cathepsin B/L release, confirming lysosomal membrane permeabilization as an executor of apoptotic signaling. These findings unveil SA's dual-targeting organelle toxicity mechanism. Our study not only elucidates key aspects of sphingolipid-mediated cytotoxicity but also provides therapeutic rationale for counteracting fumonisin B1 (FB1)-induced pathologies and related sphingolipid disorders, potentially through lysosomal stabilization or targeted ROS modulation.

The interplay between endosomal and autophagic pathways is crucial for intracellular transport and modulation of pathogen replication. However, the mechanisms underlying the interaction between endosomes and autophagosomes (APs) in the context of Staphylococcus aureus (S. aureus) infection are not well understood. Specifically, the fusion of multivesicular bodies (MVBs) or recycled endosomes (REs) with APs remains unexplored. Here, we reveal that S. aureus induces crosstalk between endosomes and APs, a process modulated by Ca2+ influx. Depletion of Rab11A from REs impairs APs formation and trafficking. Meanwhile, we identify α-hemolysin (α-toxin, Hla) as a key virulence factor in S. aureus-induced membrane damage. α-Hemolysin facilitates S. aureus escape from vesicles, contributing to cytotoxicity and membrane disruption.

Avian reovirus (ARV) represents a significant avian pathogen that imposes substantial economic burdens on the global poultry industry. Although it is primarily associated with arthritis and tenosynovitis, certain ARV strains can induce substantial inflammatory responses and histopathological damage in organs such as the heart and liver, even in the absence of overt clinical signs. The S1 gene, a key segment of the ARV genome, encodes proteins that critically influence viral biological characteristics. Its molecular architecture has been closely linked to viral virulence, pathogenic mechanisms, infectivity, and host immune modulation, though the precise regulatory pathways remain incompletely elucidated. A deeper understanding of the S1 gene is therefore crucial for unraveling ARV's pathogenesis. This review systematically examines the role of the S1 gene in reovirus-induced pathogenicity and discusses its implications for the development of novel vaccine strategies.

Staphylococcus aureus, a common pathogen, is capable of producing a significant array of toxins and can develop biofilms or small colony variants (SCVs) to evade detection by the immune system and resist the effects of antibiotics. Its ability to persist for extended periods within host cells has led to increased research interest. This review examines the process of internalization of S. aureus, highlighting the impact of its toxins and adhesion factors on host cells. It elucidates the intricate interactions between them and the host cellular environment, thereby offering potential strategies for the treatment and prevention of S. aureus infections.

IntroductionMorganella morganii (M. morganii) is a Gram-negative opportunistic pathogen, whose increasing virulence and antibiotic resistance negatively impact dairy cow health and productivity, raising concerns in livestock health management. To mitigate this risk, rapid and reliable diagnostic methods for detection are essential. Currently, detection methods for M. morganii are underdeveloped, prompting us to develop both pathogenic and serological detection methods, including an optimized PCR technique and an indirect enzyme-linked immunosorbent assay (I-ELISA).MethodsThe optimized PCR method utilized bacterial suspensions directly as templates, bypassing the need for DNA extraction and thereby allowing the direct detection of M. morganii in fecal samples. Primer concentrations and annealing temperatures were optimized to minimize primer dimer formation, ensuring high specificity. Clinical evaluation was conducted using 771 fecal and nasal fluid samples collected from dairy farms in five regions. The I-ELISA method was developed using M. morganii lipoprotein (LPP) antigen. Parameters such as antigen coating, blocking conditions, and antibody dilution were optimized to improve specificity. Stability and reproducibility were validated through intra- and inter-assay tests. A total of 476 serum samples from dairy cows were tested to assess the method’s clinical applicability.ResultsThe optimized PCR method demonstrated high sensitivity and specificity, achieving a detection threshold of 0.2 CFU/μL. Clinical testing revealed a positivity rate of 1.4% among 771 fecal and nasal fluid samples. The I-ELISA method showed excellent stability and reproducibility, confirmed through intra- and inter-assay consistency. In testing 476 dairy cow serum samples, the positivity rate for M. morganii was 5.9%. These results indicate the utility of I-ELISA as a reliable serological diagnostic tool.DiscussionThe PCR and I-ELISA methods collectively offer practical solutions for the early clinical diagnosis of M. morganii infections in dairy cows. The PCR technique’s efficiency and sensitivity make it ideal for pathogen detection in fecal samples, while the I-ELISA method provides a robust platform for serological analysis. Together, these tools enable timely intervention, contributing to improved livestock health management and mitigating the negative impacts of M. morganii on dairy cow productivity. Future research may focus on further refining these techniques and exploring their applications in broader livestock management contexts.

Avian reovirus (ARV), a highly pathogenic agent in poultry, causes severe economic losses through immunosuppression and secondary infections. Traditional diagnostic methods like reverse transcription quantitative PCR (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA) face limitations in resource-limited settings due to equipment dependency and prolonged processing. To address this, we developed a rapid, portable detection method integrating reverse transcription–recombinase-aided amplification (RT-RAA) with CRISPR/Cas12a. By targeting the conserved P17-coding region of the ARV S1 gene, this assay amplifies viral RNA isothermally (37 °C) within 20 min, followed by Cas12a-mediated collateral cleavage of fluorescent or lateral flow reporters for visual readout. The method achieved a sensitivity of 1 copy/μL, surpassing RT-qPCR (10 copies/μL), and completed detection in 40 min. Specificity tests against non-target pathogens confirmed zero cross-reactivity. Utilizing a portable incubator and low-cost visual tools, this platform eliminates reliance on thermocyclers and skilled personnel. Its field-deployable design enables on-site diagnosis, facilitating early ARV detection to mitigate outbreaks and economic losses in poultry farming. This study provides a paradigm shift in avian pathogen surveillance, combining speed, sensitivity, and accessibility for global agricultural and public health applications.

IntroductionThis study systematically analyzed bacterial diversity and antimicrobial resistance (AMR) profiles in bulk tank milk from five dairy farms (n = 30) in Shandong Province, China, to assess public health risks associated with microbial contamination and provide critical data for regional quality control and AMR risk assessment in dairy production systems.MethodsTotal bacterial counts were quantified, revealing significant inter-farm variation (P < 0.05) with a range of 3.94–6.68 log CFU/mL. Among 129 bacterial isolates, genus-level dominance and species prevalence were identified. Antimicrobial susceptibility testing (AST) against 10 agents was performed using integrated resistance criteria combining Clinical and Laboratory Standards Institute (CLSI) standards and epidemiological cutoff values (ECOFFs). Nine resistance genes targeting seven antibiotic classes were detected via PCR.ResultsThe highest resistance rate was observed for sulfadiazine (53.2%) and the lowest for levofloxacin (6.0%). Multidrug resistance was detected in 23% (20/87) of isolates, with 14 strains meeting ECOFFs-based resistance criteria. PCR analysis showed sul1 (70.5%) and ant(4′)-Ia (54.3%) as the most prevalent resistance genes, while mcr-1, lnu (B), and blaNDM-1 were absent in all isolates. Regional resistance variations correlated significantly with farm management practices.DiscussionThese findings underscore the impact of historical antibiotic use on AMR dissemination. Enhanced AMR surveillance in raw milk, improved antibiotic stewardship, and targeted interventions are crucial to mitigate public health risks from microbial contamination and horizontal gene transfer of resistance determinants.

Porcine circovirus type 2 (PCV2) infection cause multi-systemic inflammation in pigs. Platycodon grandiflorus polysaccharide (PGPSt) has been reported to have the effects of immune regulation and disease resistance. Nevertheless, the role and mechanism of PGPSt in the inflammatory response of 3D4/21 cells induced by PCV2 infection remain unclear. The present study aims to investigate effects of PGPSt on inflammatory response and its possible underlying mechanisms in vitro models. Cells were treated with PCV2 for 36 h to construct a cell inflammation model. The 3D4/21 cell lines were pretreated with or without PGPSt, and the changes of inflammation-related markers and the signaling pathway were detected by CCK-8, ELISA, qPCR and Western blot. The results showed that PGPSt was non-toxic to cells and protected PCV2-infected cells from inflammatory damage. PGPSt could significantly inhibit the high acetylation of histone H3 (AcH3) and histone H4 (AcH4), down-regulate HAT and up-regulate HDAC activity, and reduce the expression of pro-inflammatory enzymes iNOS and COX-2 proteins levels. Then the levels of IL-1β, IL-6 and TNF-α were significantly inhibited, and the level of IL-10 was promoted. We also observed that PGPSt inhibited the phosphorylation of p65, p38 and Erk1/2, which subsequently inhibited nuclear translocation of NF-κB p65 to express pro-inflammatory factors. In conclusion, PGPSt can reduce the inflammatory response by regulating histone acetylation, reducing the release of inflammatory factors, reducing the expression of pro-inflammatory enzymes, and inhibiting the activation of NF-κB and MAPKs signaling pathways. This suggests that PGPSt had an anti-inflammatory effect on the inflammatory response caused by PCV2 infection, which provided theoretical data support for the research.

Global milk consumption exceeds 800 million tons a year and is still growing. Milk quality and its products are critical to human health. A teat cup makes direct contact with the cow’s teats during milking and its cleanliness is very important for the quality of raw milk. In this study, the microorganism from post-milking teat cup liners were collected from six dairy farms in Shandong Province of China, the bacterial species were identified using microbial mass spectrometry, the minimum inhibitory concentrations of the isolated strains against ten antimicrobial agents were determined using the broth microdilution method, and the antimicrobial resistance genes were detected by PCR. The results indicated that the most frequently isolated bacteria in this study were Bacillus licheniformis (39/276, 14.13%), followed by Bacillus pumilus (20/276, 7.25%), Bacillus cereus (17/276, 6.16%), and Bacillus subtili (16/276, 5.80%). The isolates exhibited the highest average resistance to lincomycin (87.37%), followed by sulfadiazine (61.05%) and streptomycin (42.63%); the highest detection rate of resistance genes was Sul1 (55.43%), followed by ant(4’) (51.09%), tet(M) (25.36%), blaKPC (3.62%) and qnrS (3.62%). These findings imply the necessity for enhanced measures in disinfecting cow udders and milking equipment, highlighting the persistently challenging issue of antimicrobial resistance in Shandong Province.