The Involvement of Histone H3 Acetylation in Bovine Herpesvirus 1 Replication in MDBK Cells

Histone H2B lysine lactylation modulates the NF-κB response via KPNA2 during CSFV infection

Histone lysine lactylation (Kla) has recently been reported to participate in various biological processes, regulating transcription, inflammation, and immune-related diseases. However, the mechanism of histone Kla in innate immunity and viral infection remains largely unknown. Here, we observed fluorescent Kla signals in all four histones (H2A, H2B, H3, and H4) in PK-15 cells. Immunoprecipitation analysis showed prominent histone Kla protein bands, with H2B being the most abundant. We generated the H2B K16R mutant plasmid and identified K16 as one of the Kla modification sites in H2B. Further exploration revealed increased global H2B Kla and H2BK16la levels upon classical swine fever virus (CSFV) infection. By employing the Kla agonist (L-lactate), inhibitor (oxamate), or siLDHA, we demonstrated that H2BK16la and pan Kla in PK-15 cells rely on the LDHA-lactate axis, which is also crucial for CSFV-induced H2BK16la and pan Kla levels. Moreover, our data proved the interaction between H2B and CSFV NS4A protein. Notably, H2B Kla can modulate CSFV proliferation. Mechanistically, H2BK16la and pan Kla activate the nuclear factor kappa B (NF-κB) pathway by mediating p65 nuclear translocation via karyopherin α2 (KPNA2), thereby inducing type III interferon (IFN-λ) expression and inhibiting CSFV replication. In conclusion, our study unveils the role of H2B Kla in regulating the NF-κB pathway during viral infection, presenting a novel mechanism. These findings significantly contribute to understanding the pathogenic mechanisms during viral infection and hold promise for the development of viral therapeutic strategies.

Class IIa histone deacetylase (HDAC) inhibitor TMP269 suppresses lumpy skin disease virus replication by regulating host lysophosphatidic acid metabolism

Lumpy skin disease virus (LSDV) infection poses a significant threat to global cattle farming. Currently, effective therapeutic agents are lacking. TMP269, a small molecule inhibitor of class IIa histone deacetylase inhibitor, plays a vital role in cancer therapy. In this study, we demonstrated that TMP269 treatment inhibits the early-stage replication of LSDV in a dose-dependent manner. RNA sequencing data revealed that metabolism-related signaling pathways were significantly enriched after LSDV infection. Furthermore, untargeted metabolomics analysis revealed that lysophosphatidic acid (LPA), a key metabolite of the glycerophospholipid pathway, was upregulated following LSDV infection and downregulated after TMP269 treatment. In addition, exogenous LPA promotes LSDV replication by activating the mitogen-activated protein kinase (MEK)/extracellular-signal-regulated kinase (ERK) signaling pathway and suppressing the host's innate immune response. Furthermore, treatment with the LPA receptor inhibitor Ki16425 suppressed LSDV replication and promoted the host's innate immune response. These findings suggest that LSDV infection can induce LPA expression and aid viral activation of the MEK/ERK signaling pathway and escape of the host's innate immune response, whereas TMP269 treatment can inhibit LPA production and limit its promotion of LSDV replication. These data identified the antiviral mechanism of TMP269 and a novel mechanism by which LSDV inhibits host innate immune responses, providing insights into the development of new preventive or therapeutic strategies targeting altered metabolic pathways.IMPORTANCELumpy skin disease virus (LSDV) poses a significant threat to global cattle farming. Owing to insufficient research on LSDV infection, pathogenesis, and immune escape mechanisms, prevention and control methods against LSDV infection are lacking. Here, we found that TMP269, a class IIa histone deacetylase inhibitor, significantly inhibited LSDV replication. We further demonstrated that TMP269 altered LSDV infection-induced host glycerophospholipid metabolism. In addition, TMP269 decreased the accumulation of lysophosphatidic acid (LPA), a key metabolite in glycerophospholipid metabolism, induced by LSDV infection, and exogenous LPA-promoted LSDV replication by activating the mitogen-activated protein kinase (MEK)/extracellular-signal-regulated kinase (ERK) signaling pathway and suppressing the host innate immune response. Our findings identified the antiviral mechanism of TMP269 and a novel mechanism by which LSDV manipulates host signaling pathways to promote its replication, offering insights into the development of novel antiviral agents against LSDV infection.

Quercetin alleviates depressive-like behavior by modulating acetyl-H3K9 mediated ferroptosis pathway in hypothalamus of perimenopausal depression rat model

Perimenopausal depression is a subtype of depression and is prevalent among perimenopausal women, which has brought a heavy burden to family and society. The pathogenesis of perimenopausal depression is still unclear, which affects the prevention and treatment of perimenopausal depression to a certain extent. Quercetin is a flavonoid compound, and has estrogenic activity and pharmacological effects such as antioxidant, anti-inflammatory, and neuroprotective effects. This study investigated whether quercetin improved perimenopausal depression-like behaviors and potential mechanism. The results demonstrated that quercetin could alleviate the depression-like behaviors in perimenopausal depression rat model, inhibit astrocyte activation, improve ferroptosis-associated mitochondrial damage (such as mitochondrial pyknosis and mitochondrial cristae reduction) in hypothalamus, increase the expressions of histone 3 lysine 9 acetylation (acetyl-H3K9), ferroptosis-associated protein including glutathione peroxidase 4 (GPX4) and Xc- antiporter (SLC7A11), and reduce the expressions of endoplasmic reticulum stress-related proteins including inositol-requiring enzyme 1 (IRE1α), phosphorylated IRE1α (p-IRE1α), X-box binding protein 1 (XBP1) and glucose-regulated protein 78 (GRP78) in hypothalamus of perimenopausal depression rat model. Furtherly, in vitro study indicated that quercetin could restore histone acetylase (HAT)/histone deacetylase (HDAC) homeostasis through binding to estrogen receptors and increase the expression of acetyl-H3K9, inhibiting ferroptosis through IRE1α/XBP1 pathway in astrocytes of hypothalamus. Our findings demonstrated that acetyl-H3K9 is a crucial target in development of perimenopausal depression, and quercetin exhibited antidepressant effects through modulating acetyl-H3K9 mediated ferroptosis in perimenopausal depression. Quercetin might be the prevention and adjuvant treatment strategy of perimenopausal depression.

Quantitative analysis of acetylation in peste des petits ruminants virus-infected Vero cells

BACKGROUND

Peste des petits ruminants virus (PPRV) is a highly contagious pathogen that strongly influences the productivity of small ruminants worldwide. Acetylation is an important post-translational modification involved in regulation of multiple biological functions. However, the extent and function of acetylation in host cells during PPRV infection remains unknown.

METHODS

Dimethylation-labeling-based quantitative proteomic analysis of the acetylome of PPRV-infected Vero cells was performed.

RESULTS

In total, 1068 proteins with 2641 modification sites were detected in response to PPRV infection, of which 304 differentially acetylated proteins (DAcPs) with 410 acetylated sites were identified (fold change < 0.83 or > 1.2 and P < 0.05), including 109 up-regulated and 195 down-regulated proteins. Gene Ontology (GO) classification indicated that DAcPs were mostly located in the cytoplasm (43%) and participated in cellular and metabolic processes related to binding and catalytic activity. Functional enrichment indicated that the DAcPs were involved in the minichromosome maintenance complex, unfolded protein binding, helicase activity. Only protein processing in endoplasmic reticulum pathway was enriched. A protein-protein interaction (PPI) network of the identified proteins further indicated that a various chaperone and ribosome processes were modulated by acetylation.

CONCLUSIONS

To the best of our knowledge, this is the first study on acetylome in PPRV-infected host cell. Our findings establish an important baseline for future study on the roles of acetylation in the host response to PPRV replication and provide novel insights for understanding the molecular pathological mechanism of PPRV infection.

Isoforms of autophagy-related proteins: role in glioma progression and therapy resistance

Autophagy is the process of recycling and utilization of degraded organelles and macromolecules in the cell compartments formed during the fusion of autophagosomes with lysosomes. During autophagy induction the healthy and tumor cells adapt themselves to harsh conditions such as cellular stress or insufficient supply of nutrients in the cell environment to maintain their homeostasis. Autophagy is currently seen as a form of programmed cell death along with apoptosis and necroptosis. In recent years multiple studies have considered the autophagy as a potential mechanism of anticancer therapy in malignant glioma. Although, subsequent steps in autophagy development are known and well-described, on molecular level the mechanism of autophagosome initiation and maturation using autophagy-related proteins is under investigation. This article reviews current state about the mechanism of autophagy, its molecular pathways and the most recent studies on roles of autophagy-related proteins and their isoforms in glioma progression and its treatment.

The protective effect of beta-hydroxybutyric acid on renal glomerular epithelial cells in adriamycin-induced injury

Beta-hydroxybutyric acid (BHB) exerts a protective effect in experimental of kidney disease models. However, the mechanisms underlying this activity are not well defined. BHB stands out for its ability to inhibit the Nε-lysine acetylation of histone and non-histone proteins, which may affect cellular processes and protein functions. In adriamycin-injured murine glomerular podocytes, BHB ameliorates podocyte damage and preserves actin cytoskeleton integrity, reminiscent of the effect of MS275, a highly selective inhibitor of lysine deacetylase. Further research found that adriamycin causes the reduced acetylation of nephrin, WT-1, and GSK3β. This process is abrogated by the lysine deacetylase inhibitor or BHB, suggesting that the acetylation of these molecules regulates their activity. In contrast, anacardic acid, a selective inhibitor of acetyltransferase, decreases the acetylation of nephrin, WT-1, and GSK3β and mitigates the podocyte protective effects of BHB. Taken together, BHB attenuates adriamycin-elicited glomerular epithelial cell injury, at least in part, by inhibiting the deacetylation of the key molecules implicated in glomerular injury.

Oncolytic Bovine Herpesvirus 1 Inhibits Human Lung Adenocarcinoma A549 Cell Proliferation and Tumor Growth by Inducing DNA Damage

Bovine herpesvirus 1 (BoHV-1) is a promising oncolytic virus with broad antitumor spectrum; however, its oncolytic effects on human lung adenocarcinoma in vivo have not been reported. In this study, we report that BoHV-1 can be used as an oncolytic virus for human lung adenocarcinoma, and elucidate the underlying mechanism of how BoHV-1 suppresses tumor cell proliferation and growth. First, we examined the oncolytic activities of BoHV-1 in human lung adenocarcinoma A549 cells. BoHV-1 infection reduced the protein levels of histone deacetylases (HDACs), including HDAC1-4 that are promising anti-tumor drug targets. Furthermore, the HDAC inhibitor Trichostatin A (TSA) promoted BoHV-1 infection and exacerbated DNA damage and cytopathology, suggesting a synergy between BoHV-1 and TSA. In the A549 tumor xenograft mouse model, we, for the first time, showed that BoHV-1 can infect tumor and suppressed tumor growth with a similar high efficacy as the treatment of TSA, and HDACs have potential effects on the virus replication. Taken together, our study demonstrates that BoHV-1 has oncolytic effects against human lung adenocarcinoma in vivo.

Role of the Bombyx mori nucleopolyhedrovirus LEF3 acetylation on viral replication

Late expression factor 3 (LEF3) is a single-stranded DNA binding protein of Bombyx mori nucleopolyhedrovirus (BmNPV) with multiple functions. It is an essential factor for viral DNA replication and plays an important regulatory role during BmNPV infection. Our recent quantitative analysis of protein acetylome revealed for the first time that LEF3 can be acetylated at four lysine residues during the viral infection, but the underlying mechanism is unknown. Among the modification sites, two of them (K18 and K27) are located in the conserved nuclear localization sequence region. The acetylation level for K18 especially was up-regulated approximately 7.4 times after 36 h of post-infection. To understand the regulatory function of this modification, site-direct mutagenesis for acetylated mimic (K18Q) or deacetylated mimic (K18R) mutants was performed on LEF3. The fluorescence analysis results showed that the replication capacity of the virus was significantly reduced after K18 acetylation. Meanwhile, co-localization analysis revealed that acetylation at K18 caused LEF3 to lose its nuclear targeting ability and affected the interaction between LEF3 and P143, retaining P143 in the cytoplasm. And further Yeast two-hybrid analysis results also confirmed that the acetylation at K18 did affect the interaction between LEF3 and P143. In conclusion, the acetylation of LEF3 at K18 might act as one of the antiviral strategies for silkworm host by affecting nuclear localization of LEF3, interaction with P143, and then blocking viral replication.

A histone K-lysine acetyltransferase CqKAT2A-like gene promotes white spot syndrome virus infection by enhancing histone H3 acetylation in red claw crayfish Cherax quadricarinatus

In contrast to that hypoacetylation of histones is associated with condensed chromatin and gene silencing, the hyperacetylation of histones can promote an "open chromatin" conformation and transcriptional activation, which is recruited by some viruses to enhance the viral genome replication in host cells. However, the function of histone acetylation modification in the infection of white spot syndrome virus (WSSV), one of the most virulent pathogens for crustaceans like shrimp and crayfish at present, is still unknown. Previously, we found that the transcript of a histone K-Lysine acetyltransferase CqKAT2A-like gene was down-regulated in a differentially expressed transcriptome library of the haematopietic tissue (Hpt) cells from red claw crayfish Cherax quadricarinatus upon WSSV infection at 12 hpi. To further reveal its possible role in anti-WSSV response, CqKAT2A-like gene was then identified with an open reading frame (ORF) of 2523 bp encoding 840 amino acids, which contained a conserved PCAF-N domain, acetyltransf1 domain and bromo domain. Gene expression analysis showed that CqKAT2A-like was distributed in all tissues examined with high presence in haemocyte and muscle, and the transcript was significantly down-regulated after WSSV infection in Hpt cells. Furthermore, the level of histone H3 acetylation (H3ac) was strongly reduced by gene silencing of CqKAT2A-like, which was accompanied with the significantly decreased gene expression of WSSV in Hpt cells, suggesting that CqKAT2A-like gene can promote the activity H3ac and the replication of WSSV. When the H3ac was induced by histone deacetyltransferase inhibitor TSA, the transcription of WSSV genes including both IE1 and VP28 genes was significantly increased, indicating that H3ac participated in WSSV infection in Hpt cells. Taken together, these data suggest that CqKAT2A-like gene might promote the replication of WSSV by regulating H3ac, which sheds new light on the pathogenesis of WSSV in crustaceans.

The Antiviral Effects of Sodium Phenylbutyrate Against BoHV-1 Infection In Vitro

Introduction:

The alteration of histone acetylation is a known mechanism to regulate gene expression, and thereby affecting various cellular processes. Histone deacetylases (HDACs) are known to regulate histone acetylation by removal of the acetyl group from lysines. HDAC inhibitor such as Sodium Phenylbutyrate (PB) and Valproic Acid (VPA) have been reported to affect multiple virus infection while whether they affect BoHV-1 infection is unknown.

Objective:

The aim of the study is to investigate whether PB and VPA effects BoHV-1 infection and the virus induced inflammation related signaling including Erk1/2 and p38MAPK signaling.

Methods:

To assess the antiviral effects of PB and VPA on BoHV-1 infection, MDBK cells were treated with these inhibitors at different concentrations. Then time addition was performed to pinpoint which stages of virus infection was affected by the chemicals. In order to assess whether PB affect viral gene expression, we detected the viral IE genes such as bICP0, bICP4 and bICP22 using real-time PCR assay. The effects of PB had on the activation of inflammation related signaling including Erk1/2 and p38MAPK in response to the virus infection were also detected.

Results:

Here, for the first time we reveals that PB but not VPA affects BoHV-1 infection at late stages of infection. It affected the expression of IE genes such as bICP0, bICP4 and bICP22. Interestingly, PB enhanced the activation of both Erk1/2 and p38MAPK signaling stimulated by BoHV-1 infection.

Conclusion:

HDAC inhibitor PB significantly inhibited BoHV-1 infection partially through the interruption of certain viral IE gene expression. Though PB has been reported to have antiinflammatory effects, we found that it enhanced the activation of inflammation pertinent signaling of both Erk1/2 and p38MAPK stimulated by BoHV-1 infection.

Bovine Herpesvirus 1 Productive Infection Led to Inactivation of Nrf2 Signaling through Diverse Approaches

Bovine herpesvirus type 1 (BoHV-1) is a significant cofactor for bovine respiratory disease complex (BRDC), the most important inflammatory disease in cattle. BoHV-1 infection in cell cultures induces overproduction of pathogenic reactive oxygen species (ROS) and the depletion of nuclear factor erythroid 2 p45-related factor 2 (Nrf2), a master transcriptional factor regulating a panel of antioxidant and cellular defense genes in response to oxidative stress. In this study, we reported that the virus productive infection in MDBK cells at the later stage significantly decreased the expression levels of heme oxygenase-1 (HO-1) and NAD(P)H quinone oxidoreductase-1 (NQO1) proteins, the canonical downstream targets regulated by Nrf2, inhibited Nrf2 acetylation, reduced the accumulation of Nrf2 proteins in the nucleus, and relocalized nuclear Nrf2 proteins to form dot-like staining patterns in confocal microscope assay. The differential expression of Kelch-like ECH associated protein 1 (KEAP1) and DJ-1 proteins as well as the decreased association between KEAP1 and DJ-1 promoted Nrf2 degradation through the ubiquitin proteasome pathway. These data indicated that the BoHV-1 infection may significantly suppress the Nrf2 signaling pathway. Moreover, we found that there was an association between Nrf2 and LaminA/C, H3K9ac, and H3K18ac, and the binding ratios were altered following the virus infection. Taken together, for the first time, we provided evidence showing that BoHV-1 infection inhibited the Nrf2 signaling pathway by complicated mechanisms including promoting Nrf2 degradation, relocalization of nuclear Nrf2, and inhibition of Nrf2 acetylation.