Classical swine fever virus inhibits serine metabolism-mediated antiviral immunity by deacetylating modified PHGDH.

Classical swine fever virus (CSFV), an obligate intracellular pathogen, hijacks cellular metabolism to evade immune surveillance and facilitate its replication. The precise mechanisms by which CSFV modulates immune metabolism remain largely unknown. Our study reveals that CSFV infection disrupts serine metabolism, which plays a crucial role in antiviral immunity. Notably, we discovered that CSFV infection leads to the deacetylation of PHGDH, a key enzyme in serine metabolism, resulting in autophagic degradation. This deacetylation impairs PHGDH's enzymatic activity, reduces serine biosynthesis, weakens innate immunity, and promotes viral proliferation. Molecularly, CSFV infection induces the association of HDAC3 with PHGDH, leading to deacetylation at the K364 site. This modification attracts the E3 ubiquitin ligase RNF125, which facilitates the addition of K63-linked ubiquitin chains to PHGDH-K364R. Subsequently, PHGDH is targeted for lysosomal degradation by p62 and NDP52. Furthermore, the deacetylation of PHGDH disrupts its interaction with the NAD+ substrate, destabilizing the PHGDH-NAD complex, impeding the active site, and thereby inhibiting de novo serine synthesis. Additionally, our research indicates that deacetylated PHGDH suppresses the mitochondria-MAVS-IRF3 pathway through its regulatory effect on serine metabolism, leading to decreased IFN-ß production and enhanced viral replication. Overall, our findings elucidate the complex interplay between CSFV and serine metabolism, revealing a novel aspect of viral immune evasion through the lens of immune metabolism. IMPORTANCE: Classical swine fever (CSF) seriously restricts the healthy development of China's aquaculture industry, and the unclear pathogenic mechanism and pathogenesis of classical swine fever virus (CSFV) are the main obstacle to CSF prevention, control, and purification. Therefore, it is of great significance to explore the molecular mechanism of CSFV and host interplay, to search for the key signaling pathways and target molecules in the host that regulate the replication of CSFV infection, and to elucidate the mechanism of action of host immune dysfunction and immune escape due to CSFV infection for the development of novel CSFV vaccines and drugs. This study reveals the mechanism of serine metabolizing enzyme post-translational modifications and antiviral signaling proteins in the replication of CSFV and enriches the knowledge of CSFV infection and immune metabolism.

Metal-support spin orders: Crucial effect on electrocatalytic oxygen reduction.

Magnetic property (e.g. spin order) of support is of great importance in the rational design of heterogeneous catalysts. Herein, we have taken the Ni-supported ferromagnetic (FM) CrBr3 support (Nix/CrBr3) to thoroughly investigate the effect of spin-order on electrocatalytic oxygen reduction reaction (ORR) via spin-polarized density functional theory calculations. Specifically, Ni loading induces anti-FM coupling in Ni-Cr, leading to a transition from FM-to-ferrimagnetic (FIM) properties, while Ni-Ni metallic bonds create a robust FM direct exchange, benefiting the improvement of the phase transition temperature. Interestingly, with the increase in Ni loading, the easy magnetic axis changes from out-of-plane (2D-Heisenberg) to in-plane (2D-XY). The adsorption properties of Nix/CrBr3, involving O2 adsorption energy and configuration, are not governed by the d-band center but strongly correlate with magnetic anisotropy. It is noteworthy that the applied potential and electrolyte acidity triggers spin-order transition phenomena during the ORR and induces the catalytic pathway change from 4e- ORR to 2e- ORR with the excellent onset potential of 0.93 V/reversible hydrogen electrode, comparable to the existing most excellent noble-metal catalysts. Generally, these findings offer new avenues to understand and design heterogeneous catalysts with magnetic support.

Magnetic Order Transition of a Two-Dimensional Square-Lattice Electrocatalyst Assembled by Fe-N4 Units: Crucial Role on Oxygen Reduction.

Herein, we theoretically investigate the effect of magnetic orders on electrocatalytic oxygen reduction reaction (ORR) properties on the Fe-N4 site-embedded two-dimensional (2D) covalent organic framework (Fe-N4@COF-C3N2) under realistic environments. The Fe-N4@COF-C3N2 shows a 2D square-lattice (sql) topology with three magnetic order states: one ferromagnetic state (FM) and two antiferromagnetic states (AFM1 and AFM2). Specially, the electrocatalyst in the AFM2 state shows a remarkable onset potential of 0.80 V/reversible hydrogen electrode (RHE) at pH 1, superior to the existing most excellent noble-metal catalysts. Thermodynamically, the onset potential for the 4e- ORR is 0.64 V/RHE at pH 1, with a magnetic state transition process of FM → AFM1 → FM → FM → FM, while at pH 13, the onset potential for the 4e- ORR is 0.54 V/RHE, with the magnetic transition process of FM → FM → AFM1 → FM → FM. Generally, this finding will provide new avenues to rationally design the Fe-N4 electrocatalyst.

Correction: Li et al. African Swine Fever Virus: A Review. Life 2022, 12, 1255.

In the original publication [...].

Ramelteon alleviates myocardial ischemia/reperfusion injury (MIRI) through Sirt3--dependent regulation of cardiomyocyte apoptosis.

Reperfusion stands as a pivotal intervention for ischemic heart disease. However, the restoration of blood flow to ischemic tissue always lead to further damage, which is known as myocardial ischemia/reperfusion injury (MIRI). Ramelteon is an orally administered drug used to improve sleep quality, which is famous for its high bioadaptability and absence of notable addictive characteristics. However, the specific mechanism by which it improves MIRI is still unclear. Sirtuin-3 (Sirt3), primarily located in mitochondria, is crucial in mitigating many cardiac diseases, including MIRI. Based on the structure of Sirt3, we simulated molecular docking and identified several potential amino acid binding sites between it and ramelteon. Therefore, we propose a hypothesis that ramelteon may exert cardioprotective effects by activating the Sirt3 signaling pathway. Our results showed that the activation levels and expression level of Sirt3 were significantly decreased in MIRI tissue and H2O2 stimulated H9C2 cells, while ramelteon treatment upregulated Sirt3 activity and expression. After treat with 3-TYP, a classic Sirt3 activity inhibitor, we constructed myocardial ischemia/reperfusion surgery in vivo and induced H9C2 cells with H2O2 in vitro. The results showed that the myocardial protection and anti-apoptotic effects of ramelteon were antagonized by 3-TYP, indicating that the activation of Sirt3 is a key mechanism for ramelteon to exert myocardial protection. In summary, our results confirm a novel mechanism by which ramelteon improves MIRI by activating Sirt3 signaling pathway, providing strong evidence for the treatment of MIRI with ramelteon.

Berberine inhibits NLRP3 inflammasome activation by regulating mTOR/mtROS axis to alleviate diabetic cardiomyopathy.

Diabetes cardiomyopathy (DCM) refers to myocardial dysfunction and disorganization resulting from diabetes. In this study, we investigated the effects of berberine on cardiac function in male db/db mice with metformin as a positive control. After treatment for 8 weeks, significant improvements in cardiac function and a reduction in collagen deposition were observed in db/db mice. Furthermore, inflammation and pyroptosis were seen to decrease in these mice, as evidenced by decreased expressions of p-mTOR, NOD-like receptor thermal protein domain associated protein 3 (NLRP3), IL-1ß, IL-18, caspase-1, and gasdermin D (GSDMD). In vitro experiments on H9C2 cells showed that glucose exposure at 33 mmol/L induced pyroptosis, whereas berberine treatment reduced the expression of p-mTOR and NLRP3 inflammasome components. Moreover, berberine treatment was seen to inhibit the generation of mitochondrial reactive oxygen species (mtROS) and effectively improve cell damage in high glucose-induced H9C2 cells. The mTOR inhibitor, Torin-1, showed a therapeutic effect similar to that of berberine, by reducing the expression of NLRP3 inflammasome components and inhibiting mtROS generation. However, the activation of mTOR by MHY1485 partially nullified berberine's protective effects during high glucose stress. Collectively, our study reveals the mechanism that berberine regulates the mTOR/mtROS axis to inhibit pyroptosis induced by NLRP3 inflammasome activation, thereby alleviating DCM.

CSFV restricts necroptosis to sustain infection by inducing autophagy/mitophagy-targeted degradation of RIPK3.

IMPORTANCE: CSFV infection in pigs causes persistent high fever, hemorrhagic necrotizing multi-organ inflammation, and high mortality, which seriously threatens the global swine industry. Cell death is an essential immune response of the host against pathogen invasion, and lymphopenia is the most typical clinical feature in the acute phase of CSFV infection, which affects the initial host antiviral immunity. As an "old" virus, CSFV has evolved mechanisms to evade host immune response after a long genetic evolution. Here, we show that necroptosis is a limiting host factor for CSFV infection and that CSFV-induced autophagy can subvert this host defense mechanism to promote its sustained replication. Our findings reveal a complex link between necroptosis and autophagy in the process of cell death, provide evidence supporting the important role for CSFV in counteracting host cell necrosis, and enrich our knowledge of pathogens that may subvert and evade this host defense.

The Challenging Path to Diagnosing Extraintestinal Amoebiasis: A Case Report of an HIV-Infected Patient.

Background: Amoebiasis, an infectious disease caused by the parasitic protozoan E. histolytica, is easily misdiagnosed due to its declining incidence and atypical symptoms. Case Presentation: A 31-year-old male presented to the hospital with dyspnea and inability to lie flat. Imaging studies indicated a large amount of pleural effusion on the right side and multiple huge cysts in the liver. The patient underwent liver tumor resection surgery at another hospital due to suspected malignancy, but no evidence of relevant malignant tumors was found in the pathological examination. Subsequently, we performed metagenomic next-generation sequencing on the liver drainage fluid and obtained liver pathology slides from the hospital where the surgery was performed at that time. Both of them confirmed the diagnosis of amoebic infection. Empirical treatment with metronidazole was initiated before the diagnosis was confirmed, along with symptomatic treatments such as thoracic drainage and liver drainage. Eventually, the patient's condition improved and he was discharged smoothly. Conclusion: In order to avoid misdiagnosis of amoebiasis, thoroughly inquiring about the patient's medical history, shifting perspectives and continuing investigating are necessary when one diagnostic approach proves ineffective. Besides, interdisciplinary collaboration and persistent efforts are crucial for accurate diagnosis.

Visible-Light Photocatalytic Overall Water Splitting on a B4C3/CxNy Z-Scheme Heterojunction: Role of Ultrafast Carrier Recombination-Transfer Kinetics.

Herein, combining density functional theory (DFT) calculations with nonadiabatic molecular dynamics (NAMD), we built a computational framework to rationally screen from a series of 2D conjugated carbon nitrides (CNs) to match with B4C3, resulting in the excellent direct Z-scheme photocatalyst (B4C3/C6N6) for overall water splitting (OWS). Studies on interface engineering and ultrafast dynamics of carrier recombination-transfer show that in the B4C3/C6N6 system, compared with the slower interlayer migration process of carriers, strong nonadiabatic coupling and longer quantum decoherence time accelerates weak carrier interlayer recombination on a subpicosecond time scale, enabling simultaneous triggering of hydrogen evolution reaction (HER) with ΔG = -0.23 eV and spontaneous oxygen evolution reaction (OER) in the absence of sacrificial or cocatalysts. In general, our work will promote the design of efficient direct Z-scheme photocatalysts from an ultrafast dynamics perspective.

Preventive effects of Ramelteon on bleomycin-induced pulmonary fibrosis in mice.

Pulmonary fibrosis (PF) is a devastating lung disease that leads to impaired lung function and ultimately death. Several studies have suggested that melatonin, a hormone involved in regulating sleep-wake cycles, may be effective in improving PF. Ramelteon, an FDA-approved melatonin receptor agonist, has shown promise in exerting an anti-PF effect similar to melatonin. However, further investigations are required for illuminating the extent on its therapeutic benefits and the underlying molecular mechanisms. In this work, a mouse lung fibrosis model was built through intratracheal administration of bleomycin (BLM). Subsequently, the mice were administrated Ramelteon for a duration of 3 weeks to explore its efficacy and mechanism of action. Additionally, we utilized a TGF-ß1-induced MRC-5 cell model to further investigate the molecular mechanism underlying ramelteon's effects. Functionally, Ramelteon partially abrogated TGF-ß1-induced pulmonary fibrosis and reduced fibroblast proliferation, extracellular matrix deposition, and differentiation into myofibroblasts. In vivo experiments, ramelteon attenuated BLM-induced pulmonary fibrosis and collagen deposition. Mechanistically, ramelteon exerts its beneficial effect by alleviating translocation and expression of YAP1, a core component of Hippo pathway, from cytoplasm to nucleus; however, overexpression of YAP1 reversed this effect. In conclusion, our findings indicate that ramelteon can improve PF by regulating Hippo pathway and may become a potential candidate as a therapy to PF.

Role of OGDH in Atophagy-IRF3-IFN-ß pathway during classical swine fever virus infection.

Classical swine fever (CSF) is a severe infectious disease caused by the classical swine fever virus (CSFV) that poses significant challenges to the swine industry. α-ketoglutarate dehydrogenase (OGDH), the first rate-limiting enzyme of the tricarboxylic acid (TCA) cycle, catalyzes α-ketoglutarate (α-KG) to succinyl-CoA, playing a crucial role in glycometabolism. Our previous studies showed that CSFV disrupts the TCA cycle, resulting in α-KG accumulation. However, the interplay between CSFV and OGDH remains unclear. In this study, we found that CSFV significantly reduces OGDH protein levels and promotes α-KG secretion through OGDH in PK-15 cells. Furthermore, we observed CSFV C protein interacts with OGDH and revealed that CSFV utilizes NDP52/NBR1 to target OGDH protein degradation in the autophagy-lysosome pathway. We also unveiled that OGDH overexpression inhibits CSFV proliferation, whereas OGDH knockdown increases CSFV proliferation. Further investigation into the mechanisms of OGDH on CSFV replication revealed that OGDH regulates the AMPK-mTOR-autophagy pathway. Additionally, using the autophagy agonist/inhibitor, rapamycin/3-MA, we observed that OGDH modulates autophagy to regulate the IRF3-IFN-ß network and CSFV replication. These findings shed light on the role of OGDH in CSFV infection and host metabolism, promoting the development of innovative strategies for combating CSFV and other viral infections via targeting metabolic pathways.

Correlation of the spin state and catalytic property of M-N4 single-atom catalysts in oxygen reduction reactions.

The rational design of high-performance catalysts for oxygen reduction reactions (ORRs) is of great importance for large-scale applications in the field of proton-exchange membrane fuel cells and the green synthesis of H2O2. The effect of spin states of paramagnetic metal ions on the selectivity of ORRs is significant for single-atom catalysts (SACs). In this work, via spin-polarization density functional theory (DFT) calculations, we systematically investigated the popular paramagnetic metal-nitrogen graphene (M-N4-C, M = Mn, Fe, and Co) SACs to mainly focus on the correlation of spin states and catalytic performance (e.g. activity and selectivity). Both thermodynamically and kinetically, it was found that Co-N4-C (S = 1/2) has excellent 2e- oxygen reduction performance (hydrogen peroxide production) with an ultralow overpotential of 0.03 V, and the hydrogenation of OOH* is the rate-determining step (RDS) with an energy barrier of 1.20 eV. The 4e- ORR tends to occur along the OOH dissociation pathway (O* + OH*) on Co-N4-C (S = 3/2), in which OOH* decomposition is the RDS with an energy barrier of 1.01 eV. It is proved that the spin magnetic moment is the key factor to regulate the ORR property via multi-angle electronic analysis. The spin states of catalysts play a crucial role in the activity and selectivity of ORRs mainly by manipulating the bond strength between OOH and catalysts. This will provide new insights for the rational design of ORR catalysts with magnetic metals.

Rational design of bimetallic MXene solid solution with High-Performance electrocatalytic N2 reduction.

Electrocatalytic N2 reduction reaction (eNRR) was an effective alternative method for green synthesis of NH3. By combining the first-principal Density functional theory (DFT) calculations and Monte Carlo (MC) simulation, we systematacially investigated 24 types equal-ratio bimetallic MXene solid solution, involving 88 different catalysts. Our focus was on the catalytic performance of these materials in eNRR. The computational result indicate that MoW(3Mo) has high stability, selectivity (93.8 % against the hydrogen evolution reaction (HER)) and activity (UL = -0.26 V), which is significantly better than that of monometal Mo2CO2 and W2CO2. This improvement in catalytic properties is attributed to the unique electronic structure (e.g. d-band center, charge) of bimetallic MXene solid solution. In explicit solvent conditions, the microenvironment of hydrogen bond in aqueous liquid thermodynamically promotes the catalytic property for eNRR and reduce the catalytic property of HER side reaction, but the kinetic barrier is also increased due to the effect of the hydrogen-bond microenvironment on proton migration. Overall, the obtained bimetallic MXene solid solution MoW(3Mo) exhibits excellent catalytic performance in eNRR.

The regulation of cell homeostasis and antiviral innate immunity by autophagy during classical swine fever virus infection.

CSFV (classical swine fever virus) is currently endemic in developing countries in Asia and has recently re-emerged in Japan. Under the pressure of natural selection pressure, CSFV keeps evolving to maintain its ecological niche in nature. CSFV has evolved mechanisms that induce immune depression, but its pathogenic mechanism is still unclear. In this study, using transcriptomics and metabolomics methods, we found that CSFV infection alters innate host immunity by activating the interferon pathway, inhibiting host inflammation, apoptosis, and remodelling host metabolism in porcine alveolar macrophages. Moreover, we revealed that autophagy could alter innate immunity and metabolism induced by CSFV infection. Enhanced autophagy further inhibited CSFV-induced RIG-I-IRF3 signal transduction axis and JAK-STAT signalling pathway and blocked type I interferon production while reducing autophagy inhibition of the NF-κB signalling pathway and apoptosis in CSFV infection cells. Furthermore, the level of CSFV infection-induced glycolysis and the content of lactate and pyruvate, as well as 3-phosphoglyceraldehyde, a derivative of glycolysis converted to serine, was altered by autophagy. We also found that silencing HK2 (hexokinase 2), the rate-limiting enzyme of glycolytic metabolism, could induce autophagy but reduce the interferon signalling pathway, NF-κB signalling pathway, and inhibition of apoptosis induced by CSFV infection. In addition, inhibited cellular autophagy by silencing ATG5 or using 3-Methyladenine, could backfill the inhibitory effect of silencing HK2 on the cellular interferon signalling pathway, NF-κB signalling pathway, and apoptosis.

Transcriptome Profiling in Swine Macrophages Infected with African Swine Fever Virus (ASFV) Uncovers the Complex and Close Relationship with Host.

African swine fever virus (ASFV) is a pathogen to cause devastating and economically significant diseases in domestic and feral swine. ASFV mainly infects macrophages and monocytes and regulates its replication process by affecting the content of cytokines in the infected cells. There is a limited understanding of host gene expression and differential profiles before and after ASFV infection in susceptible cells. In this study, RNA-seq technology was used to analyze the transcriptomic change in PAMs infected with ASFV at different time points (0 h, 12 h, 24 h). As a result, a total of 2748, 1570, and 560 genes were enriched in group V12 h vs. MOCK, V24 h vs. MOCK, and V24 h vs. V12 h, respectively. These DEGs (differentially expressed genes) in each group were mainly concentrated in the KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways related to innate immunization and inflammation, including the NF-κB signaling pathway, Toll-like receptor signaling pathway, TNF signaling pathway, IL-17 signaling pathway, cytokine-cytokine receptor interaction, and chemokine signaling pathway. Furthermore, the increased levels of IL-1ß, TNF-α, IKKß, CXCL2, and TRAF2 and decreased level of IκBα were validated through the qPCR method. These results suggested that ASFV infection can activate the NF-κB signaling pathway in the early stage. In general, this study provides a theoretical basis for further understanding the pathogenesis and immune escape mechanism of ASFV.

Optimization of up-flow anaerobic sludge blanket second-layer influent distribution structure.

ABSTRACTA parametric model of the second-layer influent distributor is proposed to increase the reaction efficiency of the up-flow anaerobic sludge blanket. The impacts on the flow efficiency of the main parameters, including the length of distribution pipe, that is, the cylinder radius r1, the eccentricity of the nozzle e, and the number of nozzles n1, are investigated. The optimal parameter combination of the second-layer influent distributoris obtained by single factor analysis and orthogonal analysis. Then the two-layer distributor combination model, including the bottom influent distributor and the second-layer influent distributor, is established and the simulations are conducted to study the effect of the two-layer distributor on flow inside the reactor. The simulation results show that the proposed two-layer distributor can achieve a higher mixture efficiency than the single distributor.

Immunogenicity and Immunoprotection of PCV2 Virus-like Particles Incorporating Dominant T and B Cell Antigenic Epitopes Paired with CD154 Molecules in Piglets and Mice.

Porcine circovirus type 2 (PCV2) is capable of causing porcine circovirus-associated disease (PCVAD) and is one of the major threats to the global pig industry. The nucleocapsid protein Cap encoded by the PCV2 ORF2 gene is an ideal antigen for the development of PCV2 subunit vaccines, and its N-terminal nuclear localization sequence (NLS) structural domain is essential for the formation of self-assembling VLPs. In the present study, we systematically expressed and characterized full-length PCV2 Cap proteins fused to dominant T and B cell antigenic epitopes and porcine-derived CD154 molecules using baculovirus and found that the Cap proteins fusing epitopes were still capable of forming virus-like particles (VLPs). Both piglet and mice experiments showed that the Cap proteins fusing epitopes or paired with the molecular adjuvant CD154 were able to induce higher levels of humoral and cellular responses, particularly the secretion of PCV2-specific IFN-γ and IL-4. In addition, vaccination significantly reduced clinical signs and the viral load of PCV2 in the blood and tissues of challenged piglets. The results of the study provide new ideas for the development of a more efficient, safe and broad-spectrum next-generation PCV2 subunit vaccine.

Advances in the differential molecular diagnosis of vesicular disease pathogens in swine.

Foot-and-mouth disease virus (FMDV), Senecavirus A (SVA) and swine vesicular disease virus (SVDV) are members of the family Picornaviridae, which can cause similar symptoms - vesicular lesions in the tissues of the mouth, nose, feet, skin and mucous membrane of animals. Rapid and accurate diagnosis of these viruses allows for control measures to prevent the spread of these diseases. Reverse transcription-polymerase chain reaction (RT-PCR) and real-time RT-PCR are traditional and reliable methods for pathogen detection, while their amplification reaction requires a thermocycler. Isothermal amplification methods including loop-mediated isothermal amplification and recombinase polymerase amplification developed in recent years are simple, rapid and do not require specialized equipment, allowing for point of care diagnostics. Luminex technology allows for simultaneous detection of multiple pathogens. CRISPR-Cas diagnostic systems also emerging nucleic acid detection technologies which are very sensitivity and specificity. In this paper, various nucleic acid detection methods aimed at vesicular disease pathogens in swine (including FMDV, SVA and SVDV) are summarized.

Development of Foot-and-Mouth Disease Vaccines in Recent Years.

Foot-and-mouth disease (FMD) is a serious disease affecting the global graziery industry. Once an epidemic occurs, it can lead to economic and trade stagnation. In recent decades, FMD has been effectively controlled and even successfully eradicated in some countries or regions through mandatory vaccination with inactivated foot-and-mouth disease vaccines. Nevertheless, FMD still occurs in some parts of Africa and Asia. The transmission efficiency of foot-and-mouth disease is high. Both disease countries and disease-free countries should always be prepared to deal with outbreaks of FMD. The development of vaccines has played a key role in this regard. This paper summarizes the development of several promising vaccines including progress and design ideas. It also provides ways to develop a new generation of vaccines for FMDV and other major diseases.