Salvianolic acid A inhibits pseudorabies virus infection by directly inactivating the virus particle.

BACKGROUND: Pseudorabies virus (PRV), a member of the family Herpesviridae, is responsible for significant economic losses in the pig industry and has recently been associated with human viral encephalitis, leading to severe neurological symptoms post-recovery. Despite the widespread impact of PRV, there are currently no approved effective drugs for treating PRV-related diseases in humans or pigs. Therefore, the exploration and discovery of safe and effective drugs for the prevention and treatment of PRV infection is of paramount importance. PURPOSE: The objective of this study is to screen and identify natural compounds with antiviral activity against PRV. METHODS: First, we used a strain of PRV with green fluorescent protein (PRV-GFP) to screen a natural product chemical library to identify potential antiviral drugs. Next, we assessed the antiviral abilities of salvianolic acid A (SAA) in vitro using virus titer assay, qPCR, and IFA. We investigated the mechanisms of SAA's antiviral activity through viral attachment, internalization, inactivation, and nuclease digestion assay. Finally, we evaluated the efficacy of SAA in inactivating PRV using mice as the experimental subjects. RESULTS: This study screened 206 natural compounds for anti-PRV activity in vitro, resulting in the identification of seven potential antiviral agents. Notably, SAA emerged as a promising candidate with significant anti-PRV activity. The mechanism of action may be that SAA can directly inactivate the virus by disrupting viral envelope. In vivo experiments have shown that pre-incubation of SAA and PRV can effectively inhibit the infectivity and pathogenicity of PRV in mice. CONCLUSION: This study offers valuable insights into the antiviral properties of SAA, potentially informing strategies for controlling PRV epidemics and treating related diseases in both humans and animals.

Effect of pseudorabies virus infection on NMDA receptor expression in mice and its role in immunosuppression.

Pseudorabies virus (PRV), an α-herpesvirus, induces immunosuppression and can lead to severe neurological diseases. N-methyl-D-aspartate receptor (NMDAR), an important excitatory nerve receptor in the central nervous system, is linked to various nervous system pathologies. The link between NMDAR and PRV-induced neurological diseases has not been studied. In vivo studies revealed that PRV infection triggers a reduction in hippocampal NMDAR expression, mediated by inflammatory processes. Extensive hippocampal neuronal degeneration was found in mice on the 6th day by hematoxylin-eosin staining, which was strongly correlated with increased NMDAR protein expression. In vitro studies utilizing the CCK-8 assay demonstrated that treatment with an NMDAR antagonist significantly heightened the cytotoxic effects of PRV on T lymphocytes. Notably, NMDAR inhibition did not affect the replication ability of PRV. However, it facilitated the accumulation of pro-inflammatory cytokines in PRV-infected T cells and enhanced the transcription of the CD25 gene through the secretion of interleukin-2 (IL-2), consequently exacerbating immunosuppression. In this study, we found that NMDAR has functional activity in T lymphocytes and is crucial for the inflammatory and immune responses triggered by PRV infection. These discoveries highlight the significant role of NMDAR in PRV-induced neurological disease pathogenesis.

Antiviral activity of Morus alba L. extract against pseudorabies virus.

ETHNOPHARMACOLOGICAL RELEVANCE: Morus alba L. are widely used as ethnomedicine and functional food in China, Japan, Korea and other Asian countries. Morus alba L. have a variety of pharmacological activity such as antiviral, antioxidation, anti-cholesterol, anticancer, hypoglycemia, and neuroprotection. Morus alba L. has demonstrated antiviral efficacy against influenza viruses, SARS-CoV-2 and so on, but its potential activity against pseudorabies virus (PRV) remains uncertain. AIM OF THE STUDY: This study endeavors to delve into the anti-pseudorabies virus (PRV) potential of the ethanol extract of Morus alba L. leaves (MLE), while simultaneously elucidating its underlying mechanism of action. MATERIALS AND METHODS: The anti-PRV activities of Morus alba L. extracts at different concentrations were evaluated by qPCR and immunoblotting. The inhibitory effects of MLE on PRV replication in three distinct treatment modes (pretreatment, co-treatment, and post-treatment) were detected by qPCR and indirect immunofluorescence assays. qPCR was used to investigate the effects of MLE on PRV attachment, entrance, and cytokine expression in PRV-infected cells. The chemical components in MLE were analyzed by UPLC-MS/MS. RESULTS: MLE significantly inhibits PRV replication and protein expression in a dose-dependent manner. MLE displays inhibitory effects against PRV at three different modes of treatment. The most significant inhibitory effect of MLE was observed when used in co-treatment mode, resulting in an inhibition rate of 99.42%. MLE inhibits PRV infection in the early stage. MLE inhibits PRV infection by affecting viral attachment and viral entry. Furthermore, MLE exerts its inhibition on PRV replication by mitigating the heightened expression of cytokines (TNF-α and IFN-α) triggered by PRV. Analysis of its chemical composition highlights phenolic acids and flavonoids as the principal constituents of MLE. CONCLUSION: The results illustrate that MLE effectively impedes PRV infection by suppressing viral adsorption and entry, while also curbing the expression of antiviral cytokines. Therefore, MLE may be a potential resource for creating new medications to treat human and animal PRV infections.

STRAP upregulates antiviral innate immunity against PRV by targeting TBK1.

Serine/threonine kinase receptor-associated protein (STRAP) serves as a scaffold protein and is engaged in a variety of cellular activities, although its importance in antiviral innate immunity is unknown. We discovered that STRAP works as an interferon (IFN)-inducible positive regulator, facilitating type I IFN signaling during pseudorabies virus infection. Mechanistically, STRAP interacts with TBK1 to activate type I IFN signaling. Both the CT and WD40 7 - 6 domains contribute to the function of STRAP. Furthermore, TBK1 competes with PRV-UL50 for binding to STRAP, and STRAP impedes the degradation of TBK1 mediated by PRV-UL50, thereby increasing the interaction between STRAP and TBK1. Overall, these findings reveal a previously unrecognized role for STRAP in innate antiviral immune responses during PRV infection. STRAP could be a potential therapeutic target for viral infectious diseases.

Pseudorabies virus infection triggers mitophagy to dampen the interferon response and promote viral replication.

Pseudorabies virus (PRV) utilizes multiple strategies to inhibit type I interferon (IFN-I) production and signaling to achieve innate immune evasion. Among several other functions, mitochondria serve as a crucial immune hub in the initiation of innate antiviral responses. It is currently unknown whether PRV inhibits innate immune responses by manipulating mitochondria. In this study, we found that PRV infection damages mitochondrial structure and function, as shown by mitochondrial membrane potential depolarization, reduction in mitochondrial numbers, and an imbalance in mitochondrial dynamics. In addition, PRV infection triggered PINK1-Parkin-mediated mitophagy to eliminate the impaired mitochondria, which resulted in a suppression of IFN-I production, thereby promoting viral replication. Furthermore, we found that mitophagy resulted in the degradation of the mitochondrial antiviral signaling protein, which is located on the mitochondrial outer membrane. In conclusion, the data of the current study indicate that PRV-induced mitophagy represents a previously uncharacterized PRV evasion mechanism of the IFN-I response, thereby promoting virus replication.IMPORTANCEPseudorabies virus (PRV), a pathogen that induces different disease symptoms and is often fatal in domestic animals and wildlife, has caused great economic losses to the swine industry. Since 2011, different PRV variant strains have emerged in Asia, against which current commercial vaccines may not always provide optimal protection in pigs. In addition, there are indications that some of these PRV variant strains may sporadically infect people. In the current study, we found that PRV infection causes mitochondria injury. This is associated with the induction of mitophagy to eliminate the damaged mitochondria, which results in suppressed antiviral interferon production and signaling. Hence, our study reveals a novel mechanism that is used by PRV to antagonize the antiviral host immune response, providing a theoretical basis that may contribute to the research toward and development of new vaccines and antiviral drugs.

Analysis of the recombination and evolution of the new type mutant pseudorabies virus XJ5 in China.

Pseudorabies have caused enormous economic losses in China's pig industry and have recurred on many large pig farms since late 2011. The disease is caused by highly pathogenic, antigenic variant pseudorabies virus (vPRV) strains. Our laboratory isolated a pseudorabies virus in 2015 and named it XJ5. The pathogenic ability of this mutant strain was much stronger than that of the original isolate. After we sequenced its whole genome (GenBank accession number: OP512542), we found that its overall structure was not greatly changed compared with that of the previous strain Ea (KX423960.1). The whole genome alignment showed that XJ5 had a strong genetic relationship with the strains isolated in China after 2012 reported in GenBank. Based on the isolation time of XJ5 and the mutation and recombination analysis of programs, we found that the whole genome homology of XJ5 and other strains with Chinese isolates was greater than 95%, while the homology with strains outside Asia was less than 94%, which indicated that there may be some recombination and mutation patterns. We found that virulent PRV isolates emerged successively in China in 2011 and formed two different evolutionary clades from foreign isolates. At the same time, this may be due to improper immunization and the presence of wild strains in the field, and recent reports have confirmed that Bartha vaccine strains recombine with wild strains to obtain new pathogenic strains. We performed genetic evolution analysis of XJ5 isolated and sequenced in our laboratory to trace its possible mutations and recombination. We found that XJ5 may be the result of natural mutation of a virus in a branch of mutant strains widely existing in China.

Sexual Dimorphism of Spinal Neural Circuits Controlling the Mouse External Urethral Sphincter With and Without Spinal Cord Injury.

Spinal cord injury (SCI) disrupts coordination between the bladder and the external urinary sphincter (EUS), leading to transient or permanent voiding impairment, which is more severe in males. Male versus female differences in spinal circuits related to the EUS as well as post-SCI rewiring are essential for understanding of sex-/gender-specific impairments and possible recovery mechanisms. To quantitatively assess differences between EUS circuits in males versus females and in spinal intact (SI) versus SCI animals, we retrogradely traced and counted EUS-related neurons. In transgenic ChAT-GFP mice, motoneurons (MNs), interneurons (INs), and propriospinal neurons (PPNs) were retrogradely trans-synaptically traced with PRV614-red fluorescent protein (RFP) injected into EUS. EUS-MNs in dorsolateral nucleus (DLN) were separated from other GFP+ MNs by tracing them with FluoroGold (FG). We found two morphologically distinct cell types in DLN: FG+ spindle-shaped bipolar (SB-MNs) and FG- rounded multipolar (RM-MNs) cholinergic cells. Number of MNs of both types in males was twice as large as in females. SCI caused a partial loss of MNs in all spinal nuclei. After SCI, males showed a fourfold rise in the number of RFP-labeled cells in retro-DLN (RDLN) innervating hind limbs. This suggests (a) an existence of direct synaptic interactions between spinal nuclei and (b) a post-SCI increase of non-specific inputs to EUS-MNs from other motor nuclei. Number of INs and PPNs deferred between males and females: In SI males, the numbers of INs and PPNs were ∼10 times larger than in SI females. SCI caused a twofold decrease of INs and PPNs in males but not in females.

A pseudorabies outbreak in hunting dogs in Campania region (Italy): a case presentation and epidemiological survey.

BACKGROUND: Pseudorabies is an infection of domestic and wild pigs that has occasionally been reported in dogs with fatal encephalitis. Hunting dogs are predisposed to pseudorabies exposure due to incorrect practices (administration of raw infected meat) or close contact with infected wild boars. This study described an outbreak of pseudorabies in two hunting dogs in the Campania region, southern Italy. CASE PRESENTATION: Two hunting dogs were hospitalized after a hunting trip, with fever, itching, and self-inflicted lesions. Laboratory tests showed mild anemia and marked leukocytosis. Despite conservative therapy, both animals died 48 h after the presentation of symptoms. One of the carcasses was sent to the Department of Veterinary Medicine and Animal Production in Naples to confirm the suspicion of pseudorabies. DNA was extracted from different matrices and used as a template for real-time PCR to detect PRV. Several samples (brain, cerebellum, brainstem, lung, and liver) tested positive. Subsequent sequence analyses of glycoprotein E from DNA extracted from the brain stem revealed a sequence similarity to those described in previous cases of pseudorabies in dogs in Italy, France and Belgium. One month after the outbreak, blood samples were collected from 42 dogs belonging to the same hunting team and from 245 dogs (cohort population) living in the Campania region. All samples were tested with two commercial ELISAs to detect seroconversion against glycoproteins B and E. A seroprevalence of 19% was observed in the hunting team affected by the outbreak, while only 0.8% was observed in the regional dog population. CONCLUSIONS: The data reported in this study demonstrate potential exposure to PRV by dead-end hosts, particularly hunting dogs. The sequencing results indicated the homogeneity of PRV strains circulating in the different Italian regions.

TRIM26 facilitates PRV infection through NDP52-mediated autophagic degradation of MAVS.

Pseudorabies virus (PRV) has evolved multiple strategies to evade host antiviral responses to benefit virus replication and establish persistent infection. Recently, tripartite motif 26 (TRIM26), a TRIM family protein, has been shown to be involved in a broad range of biological processes involved in innate immunity, especially in regulating viral infection. Herein, we found that the expression of TRIM26 was significantly induced after PRV infection. Surprisingly, the overexpression of TRIM26 promoted PRV production, while the depletion of this protein inhibited virus replication, suggesting that TRIM26 could positively regulate PRV infection. Further analysis revealed that TRIM26 negatively regulates the innate immune response by targeting the RIG-I-triggered type I interferon signalling pathway. TRIM26 was physically associated with MAVS independent of viral infection and reduced MAVS expression. Mechanistically, we found that NDP52 interacted with both TRIM26 and MAVS and that TRIM26-induced MAVS degradation was almost entirely blocked in NDP52-knockdown cells, demonstrating that TRIM26 degrades MAVS through NDP52-mediated selective autophagy. Our results reveal a novel mechanism by which PRV escapes host antiviral innate immunity and provide insights into the crosstalk among virus infection, autophagy, and the innate immune response.

Comparative proteomic analysis of PK-15 cells infected with wild-type strain and its EP0 gene-deleted mutant strain of pseudorabies virus.

IMPORTANCE: As one of the main etiologic agents of infectious diseases in pigs, pseudorabies virus (PRV) infections have caused enormous economic losses worldwide. EP0, one of the PRV early proteins (EP) plays a vital role in PRV infections, but the mechanisms are unclear. OBJECTIVE: This study examined the function of EP0 to provide a direction for its in-depth analysis. METHODS: In this study, the EP0-deleted PRV mutant was obtained, and Tandem Mass Tag-based proteomic analysis was used to screen the differentially expressed proteins (DEPs) quantitatively in EP0-deleted PRV- or wild-type PRV-infected porcine kidney 15 cells. RESULTS: This study identified 7,391 DEPs, including 120 and 21 up-regulated and down-regulated DEPs, respectively. Western blot analysis confirmed the changes in the expression of the selected proteins, such as speckled protein 100. Comprehensive analysis revealed 141 DEPs involved in various biological processes and molecular functions, such as transcription regulator activity, biological regulation, and localization. CONCLUSIONS AND RELEVANCE: These results holistically outlined the functions of EP0 during a PRV infection and might provide a direction for more detailed function studies of EP0 and the stimulation of lytic PRV infections.

Proteomic analysis reveals the antiviral effects of baicalin on pseudorabies virus.

Pseudorabies virus (PRV) poses a significant threat to livestock and even humans. Baicalin, a bioactive flavonoid glycoside with medicinal potential, has been reported to have various biological activities. However, its inhibitory effect on PRV remains poorly understood. In this study, we proved that baicalin effectively inhibits PRV infection. Proteomic analysis revealed that baicalin reduces the expression of 14 viral proteins, which are associated with virus replication, release and immune evasion. Furthermore, the abundance of 116 host proteins was altered by PRV infection, but restored to normal levels after treatment with baicalin. Pathway analysis indicated that baicalin mitigates reactive oxygen species (ROS) and suppresses abnormal mitochondrion by reducing the expression of NFU1 iron­sulfur cluster scaffold homolog (NFU1) protein induced by PRV. Notably, baicalin also activates the complete coagulation cascade by increasing the expression of coagulation factor III (F3) protein and enhances nucleoplasm by upregulating the expression of solute carrier family 3 member 2 (SLC3A2) and CCAAT enhancer binding protein beta (CEBPB) proteins, contributing to its inhibitory effects on PRV. Our findings implied that baicalin has the potential to be developed as an anti-PRV drug and provide insights into the underlying molecular basis.

Pseudorabies virus tegument protein US2 antagonizes antiviral innate immunity by targeting cGAS-STING signaling pathway.

Background: The cGAS-STING axis-mediated type I interferon pathway is a crucial strategy for host defense against DNA virus infection. Numerous evasion strategies developed by the pseudorabies virus (PRV) counteract host antiviral immunity. To what extent PRV-encoded proteins evade the cGAS-STING signaling pathway is unknown. Methods: Using US2 stably expressing cell lines and US2-deficient PRV model, we revealed that the PRV tegument protein US2 reduces STING protein stability and downregulates STING-mediated antiviral signaling. Results: To promote K48-linked ubiquitination and STING degradation, US2 interacts with the LBD structural domain of STING and recruits the E3 ligase TRIM21. TRIM21 deficiency consistently strengthens the host antiviral immune response brought on by PRV infection. Additionally, US2-deficient PRV is less harmful in mice. Conclusions: Our study implies that PRV US2 inhibits IFN signaling by a new mechanism that selectively targets STING while successfully evading the host antiviral response. As a result, the present study reveals a novel strategy by which PRV evades host defense and offers explanations for why the Bartha-K61 classical vaccine strain failed to offer effective defense against PRV variant strains in China, indicating that US2 may be a key target for developing gene-deficient PRV vaccines.

The inhibitory effect of swine TAB1 on the replication of pseudorabies virus.

TAK1-binding protein 1 (TAB1) assembles with TAK1 through its C-terminal domain, leading to the self-phosphorylation and activation of TAK1, which plays an important role in the activation of NF-κB and MAPK signaling pathway. Pseudorabies virus (PRV) is the pathogen of Pseudorabies (PR), which belongs to the Alphaherpesvirus subfamily and causes serious economic losses to the global pig industry. However, the impact of swine TAB1 (sTAB1) on PRV infection has not been reported. In this study, evidence from virus DNA copies, virus titer and western blotting confirmed that sTAB1 could inhibit PRV replication and knockout of sTAB1 by CRISPR-Cas9 gene editing system could promote PRV replication. Further mechanistic studies by real-time PCR and luciferase reporter gene assay demonstrated that sTAB1 could enhance the production of inflammatory factors and chemokines, IFN-ß transcription level and IFN-ß promoter activity after PRV infection. In summary, we clarify the underlying mechanism of sTAB1 in inhibiting PRV replication for the first time, which provides a new idea for preventing PRV infection and lays a foundation for PRV vaccine development.

Pseudorabies virus infection increases the permeability of the mammalian respiratory barrier to facilitate Pasteurella multocida infection.

Interaction between viruses and bacteria during the development of infectious diseases is a complex question that requires continuous study. In this study, we explored the interactions between pseudorabies virus (PRV) and Pasteurella multocida (PM), which are recognized as the primary and secondary agents of porcine respiratory disease complex (PRDC), respectively. In vivo tests using mouse models demonstrated that intranasal inoculation with PRV at a sublethal dose induced disruption of murine respiratory barrier and promoted the invasion and damages caused by PM through respiratory infection. Inoculation with PRV also disrupted the barrier function of murine and porcine respiratory epithelial cells, and accelerated the adherence and invasion of PM to the cells. In mechanism, PRV infection resulted in decreased expression of tight junction proteins (ZO-1, occludin) and adherens junction proteins (ß-catenin, E-cadherin) between neighboring respiratory epithelial cells. Additionally, PRV inoculation at an early stage downregulated multiple biological processes contributing to epithelial adhesion and barrier functions while upregulating signals beneficial for respiratory barrier disruption (e.g., the HIF-1α signaling). Furthermore, PRV infection also stimulated the upregulation of cellular receptors (CAM5, ICAM2, ACAN, and DSCAM) that promote bacterial adherence. The data presented in this study provide insights into the understanding of virus-bacteria interactions in PRDC and may also contribute to understanding the mechanisms of secondary infections caused by different respiratory viruses (e.g., influenza virus and SARS-CoV-2) in both medical and veterinary medicine. IMPORTANCE: Co-infections caused by viral and bacterial agents are common in both medical and veterinary medicine, but the related mechanisms are not fully understood. This study investigated the interactions between the zoonotic pathogens PRV and PM during the development of respiratory infections in both cell and mouse models, and reported the possible mechanisms which included: (i) the primary infection of PRV may induce the disruption and/or damage of mammal respiratory barrier, thereby contributing to the invasion of PM; (ii) PRV infection at early stage accelerates the transcription and/or expression of several cellular receptors that are beneficial for bacterial adherence. This study may shed a light on understanding the mechanisms on the secondary infection of PM promoted by different respiratory viruses (e.g., influenza virus and SARS-CoV-2) in both medical and veterinary medicine.

Evaluation of the activity and mechanisms of oregano essential oil against PRV in vivo and in vitro.

BACKGROUND: The Pseudorabies Virus (PRV) leading to pseudorabies and causes huge economic losses in pig industry. The development of novel PRV variations has diminished the efficacy of traditional vaccinations, and there is yet no medication that can stop the spread of PRV infection. Therefore, PRV eradication is challenging. Oregano essential oil, the plant-based ingredient for medication feed have been shown to has strong anti-herpesvirus activity, but no anti-PRV function has been reported. RESULTS: The current study assessed the anti-pseudorabies virus (PRV) activity of oregano essential oil and explored its mechanisms and most effective components against PRV. Our in vivo findings demonstrated that oregano essential oil could decrease the PRV load in tissues, mitigate tissue lesions, and enhance the survival rate of mice. The potential antiviral mechanism involves augmenting humoral and cellular immune responses in PRV-infected mice. To further investigate the most effective components of oregano essential oil against PRV, an in vitro study was conducted, revealing that oregano essential oil and its main constituents, carvacrol and thymol, all diminished PRV intracellular proliferation in vitro. Carvacrol exhibited the most potent anti-PRV effect, serving as the primary contributor to oregano essential oil's anti-PRV activity. The mechanisms underlying carvacrol's anti-PRV properties include the upregulation of cytokines TNF-α, IFN-ß, IFN-γ, IL-12, and the inhibition of PRV-induced apoptosis in BHK-21 cells. CONCLUSIONS: Our study provides an effective drug for the prevention and control of PRV infection.

Immunological characteristics of a recombinant alphaherpesvirus with an envelope-embedded Cap protein of circovirus.

Introduction: Variant pseudorabies virus (PRV) is a newly emerged zoonotic pathogen that can cause human blindness. PRV can take advantage of its large genome and multiple non-essential genes to construct recombinant attenuated vaccines carrying foreign genes. However, a major problem is that the foreign genes in recombinant PRV are only integrated into the genome for independent expression, rather than assembled on the surface of virion. Methods: We reported a recombinant PRV with deleted gE/TK genes and an inserted porcine circovirus virus 2 (PCV2) Cap gene into the extracellular domain of the PRV gE gene using the Cre-loxP recombinant system combined with the CRISPR-Cas9 gene editing system. This recombinant PRV (PRV-Cap), with the envelope-embedded Cap protein, exhibits a similar replication ability to its parental virus. Results: An immunogenicity assay revealed that PRV-Cap immunized mice have 100% resistance to lethal PRV and PCV2 attacks. Neutralization antibody and ELISPOT detections indicated that PRV-Cap can enhance neutralizing antibodies to PRV and produce IFN-γ secreting T cells specific for both PRV and PCV2. Immunological mechanistic investigation revealed that initial immunization with PRV-Cap stimulates significantly early activation and expansion of CD69+ T cells, promoting the activation of CD4 Tfh cell dependent germinal B cells and producing effectively specific effector memory T and B cells. Booster immunization with PRV-Cap recalled the activation of PRV-specific IFN-γ+IL-2+CD4+ T cells and IFN-γ+TNF-α+CD8+ T cells, as well as PCV2-specific IFN-γ+TNF-α+CD8+ T cells. Conclusion: Collectively, our data suggested an immunological mechanism in that the recombinant PRV with envelope-assembled PCV2 Cap protein can serve as an excellent vaccine candidate for combined immunity against PRV and PCV2, and provided a cost-effective method for the production of PRV- PCV2 vaccine.

The global landscapes of lysine crotonylation in pseudorabies virus infection.

Lysine crotonylation is a common occurrence in eukaryotic cells, regulating various physiological functions, including chromatin remodeling, cellular growth, and development. However, its involvement in viral infections has rarely been documented. In this study, we reveal that pseudorabies virus (PRV) infection significantly alters the global lysine crotonylation levels in porcine kidney PK-15 cells. Specifically, we identified a few viral proteins, including UL54, gM, gD, UL19, UL37, and UL46, which undergo crotonylation modification. Our observations indicate that at 20 h post-infection (hpi), 551 crotonylation sites were reduced across 345 proteins, while 47 new sites emerged in 37 proteins compared to the control group. By 40 hpi, 263 sites had decreased in 190 proteins, while 389 new sites appeared in 240 proteins. Deeper analysis revealed that the proteins with altered crotonylation levels were primarily involved in binding, catalytic activity, biosynthetic processes, ribosome activity, and metabolic processes. Additionally, our findings underscored the significance of ribosomes and the endoplasmic reticulum (ER), which were enriched with proteins exhibiting altered crotonylation. Overall, our study for the first time offers new insights into the relationship between crotonylation and herpes virus infection, paving the way for future investigations into the role of crotonylation in viral infections.

Sex-Dimorphic Kidney-Brain Connectivity Map of Mice.

The kidneys are essential organs that help maintain homeostasis, and their function is regulated by the neural system. Despite the anatomical multi-synaptic connection between the central autonomic nuclei and the kidneys, it remains unclear whether there are any variations in neural connections between the nervous systems and the renal cortex and medulla in male and female mice. Here, we used the pseudorabies virus to map the central innervation network of the renal cortex and medulla in both sexes. The data revealed that specific brain regions displayed either a contralateral-bias or ipsilateral-bias pattern while kidney-innervating neurons distributed symmetrically in the midbrain and hindbrain. Sex differences were observed in the distribution of neurons connected to the left kidney, as well as those connected to the renal cortex and medulla. Our findings provide a comprehensive understanding of the brain-kidney network in both males and females and may help shed light on gender differences in kidney function and disease susceptibility in humans.

MARCH1 and MARCH2 inhibit pseudorabies virus replication by trapping the viral cell-to-cell fusion complex in trans-Golgi network.

The membrane-associated RING-CH (MARCH) family of proteins are members of the E3 ubiquitin ligase family and are essential for a variety of biological functions. Currently, MARCH proteins are discovered to execute antiviral functions by directly triggering viral protein degradation or blocking the furin cleavage of viral class I fusion proteins. Here, we report a novel antiviral mechanism of MARCH1 and MARCH2 (MARCH1/2) in the replication of Pseudorabies virus (PRV), a member of the Herpesviridae family. We discovered MARCH1/2 restrict PRV replication at the cell-to-cell fusion step. Furthermore, MARCH1/2 block gB cleavage, and this is dependent on their E3 ligase activity. Interestingly, the blocking of gB cleavage by MARCH1/2 does not contribute to their antiviral activity in vitro. We discovered that MARCH1/2 are associated with the cell-to-cell fusion complex of gB, gD, gH, and gL and trap these viral proteins in the trans-Golgi network (TGN) rather than degrading them. Overall, we conclude that MARCH1/2 inhibit PRV by trapping the viral cell-to-cell fusion complex in TGN.

The heat shock protein DNAJB8 inhibits pseudorabies virus replication by autophagy.

Pseudorabies virus (PRV) effectively utilizes numerous host proteins and pathways to establish a successful infection. Consequently, it becomes imperative to investigate novel host factors implicated in viral infections to gain a deeper understanding of PRV pathogenesis. In this study, we reveal that the host heat shock protein, DNAJB8, functions as a negative regulator in PRV replication. Our findings indicated that both mRNA and protein levels of DNAJB8 were downregulated in cells infected with PRV. Further analysis demonstrated that overexpressing DNAJB8 suppressed PRV replication, whereas its knockdown enhanced viral replication. From a mechanistic perspective, DNAJB8 promoted cellular autophagy, subsequently impeding viral replication. Additionally, we discovered that the transcription factor SOX30 regulated DNAJB8 expression, thereby influencing viral replication. Collectively, these findings enhance our comprehension of the roles played by DNAJB8 and SOX30 in viral replication, broadening our knowledge of virus-host interactions.