Protein Kinase R (PKR) as a Novel dsRNA Sensor in Antiviral Innate Immunity.

Protein kinase R (PKR), a key double-stranded RNA (dsRNA)-activated sensor, is pivotal for cellular responses to diverse stimuli. This protocol delineates a comprehensive methodological framework employing single luciferase assays, yeast assays, immunoblot assays, and quantitative PCR (qPCR) to discern and validate PKR activities and their downstream impacts on NF-κB-activating signaling pathways. These methodologies furnish a systematic approach to unraveling the role of PKR as a dsRNA sensor and effector in antiviral innate immunity, enabling in-depth analyses of dsRNA sensor activities.

Radiation-sensitive circRNA hsa_circ_0096498 inhibits radiation-induced liver fibrosis by suppressing EIF4A3 nuclear translocation to decrease CDC42 expression in hepatic stellate cells.

BACKGROUND: Radiation-induced liver fibrosis (RILF) is a common manifestation of radiation-induced liver injury (RILI) and is caused primarily by activated hepatic stellate cells (HSCs). Circular RNAs (circRNAs) play critical roles in various diseases, but little is known about the function and mechanism of circRNAs in RILF. METHODS: RNA pull-down and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were used to screen binding proteins of hsa_circ_0096498 (circ96498). RNA-binding protein immunoprecipitation, RNA pull-down and nuclear and cytoplasmic protein extraction were conducted to confirm the interaction between circ96498 and eukaryotic initiation factor 4A3 (EIF4A3). RNA sequencing was performed to screen target genes regulated by EIF4A3. HSCs with altered circ96498 and cell division cycle 42 (CDC42) expression were used to assess irradiated HSC activation. Circ96498 inhibition and CDC42 blockade were evaluated in RILF mouse models. RESULTS: In this study, we identified a radiation-sensitive circ96498, which was highly expressed in the irradiated HSCs of paracancerous tissues from RILI patients. Circ96498 inhibited the proliferation but promoted the apoptosis of irradiated HSCs, suppressed the secretion of proinflammatory cytokines IL-1ß, IL-6 and TNF-α, and decreased the expression of profibrotic markers (α-SMA and collagen 1) in irradiated HSCs. Mechanistically, irradiation induced the transport of EIF4A3 into the nucleus, and nuclear EIF4A3 increased the stability of CDC42 mRNA and increased CDC42 expression, thereby promoting HSC activation through the NF-κB and JNK/Smad2 pathways. However, the binding of circ96498 to EIF4A3 impeded the translocation of EIF4A3 into the nucleus, resulting in the inhibition of CDC42 expression and subsequent HSC activation. Furthermore, circ96498 knockdown promoted the development of the early and late stages of RILF in a mouse model, which was mitigated by CDC42 blockade. CONCLUSIONS: Collectively, our findings elucidate the involvement of the circ96498/EIF4A3/CDC42 axis in inhibiting irradiated HSC activation, which offers a novel approach for RILF prevention and treatment.

eIF2Bß confers resistance to Turnip mosaic virus by recruiting ALKBH9B to modify viral RNA methylation.

Eukaryotic translation initiation factors (eIFs) are the primary targets for overcoming RNA virus resistance in plants. In a previous study, we mapped a BjeIF2Bß from Brassica juncea representing a new class of plant virus resistance genes associated with resistance to Turnip mosaic virus (TuMV). However, the mechanism underlying eIF2Bß-mediated virus resistance remains unclear. In this study, we discovered that the natural variation of BjeIF2Bß in the allopolyploid B. juncea was inherited from one of its ancestors, B. rapa. By editing of eIF2Bß, we were able to confer resistance to TuMV in B. juncea and in its sister species of B. napus. Additionally, we identified an N6-methyladenosine (m6A) demethylation factor, BjALKBH9B, for interaction with BjeIF2Bß, where BjALKBH9B co-localized with both BjeIF2Bß and TuMV. Furthermore, BjeIF2Bß recruits BjALKBH9B to modify the m6A status of TuMV viral coat protein RNA, which lacks the ALKB homologue in its genomic RNA, thereby affecting viral infection. Our findings have applications for improving virus resistance in the Brassicaceae family through natural variation or genome editing of the eIF2Bß. Moreover, we uncovered a non-canonical translational control of viral mRNA in the host plant.

Interaction of chikungunya virus glycoproteins with macrophage factors controls virion production.

Despite their role as innate sentinels, macrophages can serve as cellular reservoirs of chikungunya virus (CHIKV), a highly-pathogenic arthropod-borne alphavirus that has caused large outbreaks among human populations. Here, with the use of viral chimeras and evolutionary selection analysis, we define CHIKV glycoproteins E1 and E2 as critical for virion production in THP-1 derived human macrophages. Through proteomic analysis and functional validation, we further identify signal peptidase complex subunit 3 (SPCS3) and eukaryotic translation initiation factor 3 subunit K (eIF3k) as E1-binding host proteins with anti-CHIKV activities. We find that E1 residue V220, which has undergone positive selection, is indispensable for CHIKV production in macrophages, as its mutation attenuates E1 interaction with the host restriction factors SPCS3 and eIF3k. Finally, we show that the antiviral activity of eIF3k is translation-independent, and that CHIKV infection promotes eIF3k translocation from the nucleus to the cytoplasm, where it associates with SPCS3. These functions of CHIKV glycoproteins late in the viral life cycle provide a new example of an intracellular evolutionary arms race with host restriction factors, as well as potential targets for therapeutic intervention.

The oncogenic role of EIF4A3/CDC20 axis in the endometrial cancer.

Eukaryotic initiation factor 4A-3 (EIF4A3) is a key component of the exon junction complex (EJC) and is extensively involved in RNA splicing, inducing mRNA decay, and regulating the cell cycle and apoptosis. However, the potential role of EIF4A3 in EC has not been comprehensively investigated and remains unknown. Here, we report that the expression level of EIF4A3 is dramatically elevated in endometrial cancer (EC) samples compared with normal EC samples via bioinformatics analysis and immunohistochemistry analysis, and that high expression of EIF4A3 promotes the proliferation, migration, and invasion of EC cells. Mechanistically, we found that high EIF4A3 expression stabilized cell division cyclin 20 (CDC20) mRNA, and high EIF4A3 expression induced pro-carcinogenic effects in EC cells that were efficiently antagonized upon knockdown of CDC20, as well as Apcin, an inhibitor of CDC20. These findings reveal a novel mechanism by which high expression of EIF4A3 induces CDC20 upregulation, thus leading to EC tumorigenesis and metastasis, indicating a potential treatment strategy for EC patients with high EIF4A3 expression using Apcin. KEY MESSAGES: The expression level of EIF4A3 was dramatically elevated in endometrial cancer (EC) samples compared with normal endometrial cancer samples. High EIF4A3 expression stabilized CDC20 mRNA, and high EIF4A3 expression induced pro-carcinogenic effect in EC cells which was efficiently antagonized upon knockdown of CDC20. Apcin, an inhibitor of CDC20, could effectively counteract high expression of EIF4A3 inducing EC tumourigenesis and metastasis, indicating the potential treatment strategy for EC patients with EIF4A3 high expression by using Apcin.

EIF3B affects the invasion and metastasis of hepatocellular carcinoma cells via the TGFBI/MAPK/ERK pathway.

INTRODUCTION AND OBJECTIVES: To study the effect of eukaryotic initiation factor 3B (EIF3B) on the invasion and migration of hepatocellular carcinoma (HCC) and its potential mechanism. MATERIALS AND METHODS: The clinical significance of EIF3B expression was studied with The Cancer Genome Atlas (TCGA) and Gene Expression Profiling Interaction Analysis datasets. Immunohistochemical staining and western blotting were used to examine EIF3B expression in cell lines and tissues from HCC patients. The scratch assay and transwell assay were used to measure the invasion and metastasis of different HCC cell lines in vitro. The molecular mechanism of EIF3B was determined using RNA-seq and identification of dysregulated signaling pathways. Western blotting was used to verify the alterations of EIF3B signaling functioned in the promotion of HCC progression. RESULTS: Elevated expression of EIF3B in HCC correlated significantly with aggressive clinicopathologic characteristics, including advanced tumor grade and poor prognosis. Studies with cultured cells indicated that EIF3B knockdown inhibited HCC cell invasion and metastasis by depressing the epithelial-mesenchymal transition (EMT). EIF3B also activated the TGFBI/MAPK/ERK signaling pathway by increasing the levels of pMEK and pERK. CONCLUSIONS: Our results indicate that EIF3B functions as an oncogene in HCC that accelerates cell invasion, metastasis, and the EMT by stimulation of the TGFBI/MAPK/ERK signaling pathway. EIF3B is a potential target for the treatment of HCC.

Reprograming immunosuppressive microenvironment by eIF4G1 targeting to eradicate pancreatic ductal adenocarcinoma.

Current therapies against pancreatic ductal adenocarcinoma (PDAC) have limited clinical benefits owing to tumor heterogeneity and their unique immunosuppressive microenvironments. The eukaryotic initiation factor (eIF) 4F complex is involved in regulating translation and various downstream carcinogenic signaling pathways. We report that eIF4G1, one of the subunits of eIF4F, is overexpressed in cancer cells and cancer-associated fibroblasts, and this correlates with poor prognosis in patients with PDAC. In PDAC mice, eIF4G1 inhibition limits tumor progression and prolongs overall survival, especially when combined with PD1/PDL1 antagonists and gemcitabine. Mechanistically, eIF4G1 inhibition hinders the production of cytokines and chemokines that promote fibrosis and inhibit cytotoxic T cell chemotaxis. Moreover, eIF4G1 inhibition impairs integrinß1 protein translation and exerts tumor suppression effects through the FAK-ERK/AKT signaling pathway. These findings highlight the effects of eIF4G1 on tumor immune dependence and independence and identify eIF4G1 as a promising therapeutic target for PDAC.

Insights into eukaryotic translation initiation factor 5A: Its role and mechanisms in protein synthesis.

The protein synthesis within eukaryotic cells is a complex process involving various translation factors. Among these factors, eukaryotic translation initiation factor 5A (eIF5A) emerges as a crucial translation factor with high evolutionary conservation. eIF5A is unique as it is the only protein in eukaryotic cells containing the hypusine modification. Initially presumed to be a translation initiation factor, eIF5A was subsequently discovered to act mainly during the translation elongation phase. Notably, eIF5A facilitates the translation of peptide sequences containing polyproline stretches and exerts a universal regulatory effect on the elongation and termination phases of protein synthesis. Additionally, eIF5A indirectly affects various physiological processes within the cell by modulating the translation of specific proteins. This review provides a comprehensive overview of the structure, physiological functions, various post-translational modifications of eIF5A, and its association with various human diseases. The comparison between eIF5A and its bacterial homolog, EF-P, extends the discussion to the evolutionary conservation of eIF5A. This highlights its significance across different domains of life.

Design, synthesis and biological evaluation of plant-derived miliusol derivatives achieve TNBC profound regression in vivo.

Triple-negative breast cancer has become a major problem in clinical treatment due to its high heterogeneity, and Plant-derived drug discovery has been the focus of attention for novel anti-tumor therapeutics. In this study, Miliusol, a natural product isolated from the rarely reported plant Miliusa tenuistipitata, was identified as the lead compound, and 25 miliusol derivatives were designed and synthesized under antiproliferative activity guidance. The results revealed that ZMF-24 was demonstrated to have potent anti-TNBC proliferation with IC50 values of 0.22 µM and 0.44 µM in BT-549 cells and MDA-MB-231 cells respectively with low cytotoxicity to MCF10A cells, and could significantly downregulate proliferation and migration markers. Through RNAseq analysis, molecular docking and CETSA experiment, we found that ZMF-24 could inhibit Eukaryotic translation initiation factor 3 subunit D (EIF3D) that further disrupted the energy supply of TNBC by inhibiting glycolysis, induced profound TNBC apoptosis by stimulating persistent ER stress. Importantly, ZMF-24 exhibited remarkable anti-proliferation and anti-metastasis potential in nude mice xenograft TNBC model without obvious toxicity. Collectively, the findings demonstrate ZMF-24 has significant potential as a potent chemotherapy agent against triple-negative breast cancer.

Putting a Kink in HIV-1 Particle Infectivity: Rocaglamide Inhibits HIV-1 Replication by Altering Gag-Genomic RNA Interaction.

Our examination of RNA helicases for effects on HIV-1 protein production and particle assembly identified Rocaglamide (RocA), a known modulator of eIF4A1 function, as an inhibitor of HIV-1 replication in primary CD4+ T cells and three cell systems. HIV-1 attenuation by low-nM RocA doses was associated with reduced viral particle formation without a marked decrease in Gag production. Rather, the co-localization of Gag and HIV-1 genomic RNA (gRNA) assemblies was impaired by RocA treatment in a reversible fashion. Ribonucleoprotein (RNP) immunoprecipitation studies recapitulated the loss of Gag-gRNA assemblies upon RocA treatment. Parallel biophysical studies determined that neither RocA nor eIF4A1 independently affected the ability of Gag to interact with viral RNA, but together, they distorted the structure of the HIV-1 RNP visualized by electron microscopy. Taken together, several lines of evidence indicate that RocA induces stable binding of eIF4A1 onto the viral RNA genome in a manner that interferes with the ordered assembly of Gag along Gag-gRNA assemblies required to generate infectious virions.

Ketamine Reverses Chronic Corticosterone-Induced Behavioral Deficits and Hippocampal Synaptic Dysfunction by Regulating eIF4E/BDNF Signaling.

Major depressive disorder (MDD) is a debilitating illness with a high global burden. While Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, offers rapid-acting antidepressant effects, its mechanism remains incompletely understood. Recent research suggests that dysregulation of mRNA translation via the Eukaryotic initiation factor 4E (eIF4E) pathway might contribute to depression pathophysiology. This study investigates whether Ketamine modulates eIF4E signaling in the hippocampus during its antidepressant action. Herein, adult male mice were exposed to Corticosterone, a well-established model for anxiety and depression, followed by behavioral testing and biochemical analysis. Corticosterone induced depression-like symptoms and disrupted synaptic function, including reduced TrkB/BDNF and eIF4E/MNK1/p-eIF2α/ubiquitin signaling. Ketamine treatment reversed these deficits. Notably, the eIF4E/MNK1 signaling inhibitor, eFT508, blocked Ketamine's antidepressant effect, leading to a return of depression-like phenotype and impaired synaptic signaling. Importantly, these effects were reversed by 7,8-DHF, a BDNF/TrkB signaling agonist. Mice treated with Corticosterone, Ketamine, and eFT508 and subsequently exposed to 7,8-DHF displayed normalized depression-like behaviors and restored synaptic signaling, including increased eIF4E phosphorylation and MNK1 expression. Besides, 7,8-DHF treatment enhanced p-eIF2α levels compared to the eFT508-treated group. These findings suggest that Ketamine exerts its antidepressant action through the regulation of the eIF4E/BDNF signaling pathway in the hippocampus. This study provides novel insights into the molecular mechanisms underlying Ketamine's therapeutic effects and highlights the potential of targeting this pathway for future MDD treatment strategies.

Vanishing white matter.

"Vanishing white matter" (VWM) is a leukodystrophy caused by autosomal recessive pathogenic variants in the genes encoding the subunits of eukaryotic initiation factor 2B (eIF2B). Disease onset and disease course are extremely variable. Onset varies from the antenatal period until senescence. The age of onset is predictive of disease severity. VWM is characterized by chronic neurologic deterioration and, additionally, episodes of rapid and major neurologic decline, provoked by stresses such as febrile infections and minor head trauma. The disease is dominated by degeneration of the white matter of the central nervous system due to dysfunction of oligodendrocytes and in particular astrocytes. Organs other than the brain are rarely affected, with the exception of the ovaries. The reason for the selective vulnerability of the white matter of the central nervous system and, less consistently, the ovaries is poorly understood. eIF2B is a central regulatory factor in the integrated stress response (ISR). Genetic variants decrease eIF2B activity and thereby cause constitutive activation of the ISR downstream of eIF2B. Strikingly, the ISR is specifically activated in astrocytes. Modulation of eIF2B activity and ISR activation in VWM mouse models impacts disease severity, revealing eIF2B-regulated pathways as potential druggable targets.

Rotenone-induced cell apoptosis via endoplasmic reticulum stress and PERK-eIF2α-CHOP signalling pathways in TM3 cells.

Rotenone (ROT), a widely used natural pesticide, has an uncertain effect on reproductive toxicity. In this study, we used 20 mice distributed randomly into four groups, with each group receiving ROT doses of 0, 2, 4, and 8 mg/kg/day for 28 days. The results demonstrated that ROT induced significant testicular damage, including impaired spermatogenesis, inhibition of testosterone synthesis, and apoptosis of Leydig cells. Additionally, ROT disrupted the normal ultrastructure of the endoplasmic reticulum (ER) in testicular tissue, leading to ER stress in Leydig cells. To further explore whether ROT-induced apoptosis in Leydig cells is related to ER stress, the mouse Leydig cell line (TM3 cells) was treated with ROT at 0, 250, 500, and 1000 nM. ROT inhibited TM3 cell viability, induced cytotoxicity, and reduced testosterone content in the culture supernatants. Furthermore, ROT treatment triggered apoptosis in TM3 cells by activating ER stress and the PERK-eIF2α-CHOP signalling pathway. Pre-treatment of TM3 cells exposed to ROT with the ER stress inhibitor 4-phenylbutyric acid (4-PBA) alleviated these effects, decreasing apoptosis and preserving testosterone levels. Further intervention with the PERK inhibitor GSK2606414 reduced ROT-induced apoptosis and testosterone reduction by inhibiting PERK activity. In summary, ROT-induced male reproductive toxicity is specifically driven by apoptosis, with the PERK-eIF2α-CHOP signalling pathway activated by ER stress playing a crucial role in the apoptosis of Leydig cells triggered by ROT.

Genetic investigations on singleton school aged children reveal novel variants and new candidate genes for hearing loss.

Hearing loss affects around 5% of the global population. Two preliminary studies have described genetic variants in sporadic individuals with hearing loss from Pakistan. Here we extend these studies to determine the spectrum of variants in a cohort of individuals with no previous history of hearing loss. Individuals with hearing loss born to consanguineous couples were identified from special schools. Audiograms were assessed. DNA from participants negative for GJB2 pathogenic variants was subjected to exome sequencing. Data were filtered to include variants with frequencies < 0.01 in the public databases. The effects of the missense variants on respective amino acids were analyzed by using PyMol software. Among the 44 participants, hearing loss was moderate for two individuals; 14 exhibited moderately-severe hearing loss while 25 had a severe degree of hearing loss. Hearing loss was reported to have been progressive in four participants and was currently profound in three participants. Variants were unambiguously identified in 17 genes, of which the majority affected SLC26A4. CDH23, MYO15A and OTOF were other significant contributors. Deleterious variants detected in two genes suggest new associations for hearing loss. Molecular characterization of hearing loss in our cohort revealed high genetic heterogeneity with a 75% diagnostic rate.

Deciphering colorectal cancer radioresistance and immune microrenvironment: unraveling the role of EIF5A through single-cell RNA sequencing and machine learning.

Background: Radiotherapy (RT) is a critical component of treatment for locally advanced rectal cancer (LARC), though patient response varies significantly. The variability in treatment outcomes is partly due to the resistance conferred by cancer stem cells (CSCs) and tumor immune microenvironment (TiME). This study investigates the role of EIF5A in radiotherapy response and its impact on the CSCs and TiME. Methods: Predictive models for preoperative radiotherapy (preRT) response were developed using machine learning, identifying EIF5A as a key gene associated with radioresistance. EIF5A expression was analyzed via bulk RNA-seq and single-cell RNA-seq (scRNA-seq). Functional assays and in vivo experiments validated EIF5A's role in radioresistance and TiME modulation. Results: EIF5A was significantly upregulated in radioresistant colorectal cancer (CRC) tissues. EIF5A knockdown in CRC cell lines reduced cell viability, migration, and invasion after radiation, and increased radiation-induced apoptosis. Mechanistically, EIF5A promoted cancer stem cell (CSC) characteristics through the Hedgehog signaling pathway. Analysis of the TiME revealed that the radiation-resistant group had an immune-desert phenotype, characterized by low immune cell infiltration. In vivo experiments showed that EIF5A knockdown led to increased infiltration of CD8+ T cells and M1 macrophages, and decreased M2 macrophages and Tregs following radiation therapy, thereby enhancing the radiotherapy response. Conclusion: EIF5A contributes to CRC radioresistance by promoting CSC traits via the Hedgehog pathway and modulating the TiME to an immune-suppressive state. Targeting EIF5A could enhance radiation sensitivity and improve immune responses, offering a potential therapeutic strategy to optimize radiotherapy outcomes in CRC patients.

Eukaryotic translation initiation factor 6-mediated ribosome biogenesis promotes synovial aggression and inflammation by increasing the translation of SP1 in rheumatoid arthritis.

INTRODUCTION: Fibroblast-like synoviocytes (FLSs) play critical roles in synovial inflammation and aggression in rheumatoid arthritis (RA). Here, we explored the role of eukaryotic translation initiation factor 6 (eIF6) in regulating the biological behaviors of FLSs from patients with RA. METHODS: FLSs were isolated from the synovial tissues of RA patients. Gene expression was assessed via RT-qPCR, and protein expression was evaluated via Western blotting or immunohistochemistry. Proliferation and nascent peptide synthesis were evaluated via EdU incorporation and HPG labeling, respectively. Cell migration and invasion were observed via Transwell assays. Polysome profiling was conducted to analyze the distribution of ribosomes and combined mRNAs. The in vivo effect of eIF6 inhibition was evaluated in a collagen-induced arthritis (CIA) rat model. RESULTS: We found that eIF6 expression was elevated in FLSs and synovial tissues from RA patients compared to those from healthy controls and osteoarthritis patients. Knockdown of eIF6 inhibited the migration, invasion, inflammation, and proliferation of FLSs from patients with RA. Mechanistically, eIF6 knockdown downregulated ribosome biogenesis in FLSs from with RA, leading to a decrease in the proportion of polysome-associated specificity protein 1 (SP1) mRNA and a subsequent reduction in the translation initiation efficiency of SP1 mRNA. Thus, eIF6 controls SP1 expression through translation-mediated mechanisms. Interestingly, intra-articular eIF6 siRNA treatment attenuated symptoms and histological manifestations in CIA rats. CONCLUSIONS: Our findings suggest that an increase in synovial eIF6 might contribute to rheumatoid synovial inflammation and aggression and that targeting eIF6 may have therapeutic potential in RA patients.

RBM8A, a new target of TEAD4, promotes breast cancer progression by regulating IGF1R and IRS-2.

BACKGROUND: Breast cancer (BC) is the most common malignant tumor in women worldwide, and further elucidation of the molecular mechanisms involved in BC pathogenesis is essential to improve the prognosis of BC patients. RNA Binding Motif Protein 8 A (RBM8A), with high affinity to a myriad of RNA transcripts, has been shown to play a crucial role in genesis and progression of multiple cancers. We attempted to explore its functional significance and molecular mechanisms in BC. METHODS: Bioinformatics analysis was performed on publicly available BC datasets. qRT-PCR was used to determine the expression of RBM8A in BC tissues. MTT assay, clone formation assay and flow cytometry were employed to examine BC cell proliferation and apoptosis in vitro. RNA immunoprecipitation (RIP) and RIP-seq were used to investigate the binding of RBM8A/EIF4A3 to the mRNA of IGF1R/IRS-2. RBM8A and EIF4A3 interactions were determined by co-immunoprecipitation (Co-IP) and immunofluorescence. Chromatin immunoprecipitation (Ch-IP) and dual-luciferase reporter assay were carried out to investigate the transcriptional regulation of RBM8A by TEAD4. Xenograft model was used to explore the effects of RBM8A and TEAD4 on BC cell growth in vivo. RESULTS: In this study, we showed that RBM8A is abnormally highly expressed in BC and knockdown of RBM8A inhibits BC cell proliferation and induces apoptosis in vitro. EIF4A3, which phenocopy RBM8A in BC, forms a complex with RBM8A in BC. Moreover, EIF4A3 and RBM8A complex regulate the expression of IGF1R and IRS-2 to activate the PI3K/AKT signaling pathway, thereby promoting BC progression. In addition, we identified TEAD4 as a transcriptional activator of RBM8A by Ch-IP, dual luciferase reporter gene and a series of functional rescue assays. Furthermore, we demonstrated the in vivo pro-carcinogenic effects of TEAD4 and RBM8A by xenograft tumor experiments in nude mice. CONCLUSION: Collectively, these findings suggest that TEAD4 novel transcriptional target RBM8A interacts with EIF4A3 to increase IGF1R and IRS-2 expression and activate PI3K/AKT signaling pathway, thereby further promoting the malignant phenotype of BC cells.

Melatonin inhibits bovine viral diarrhea virus replication by ER stress-mediated NF-κB signal pathway and autophagy in MDBK cells.

Bovine viral diarrhea-mucosal disease (BVD-MD) is a contagious disease in cattle, caused by the bovine viral diarrhea virus (BVDV). This virus continues to spread globally, exerting pressure on both public health and the economy. Despite its impact, there are currently no effective drugs for treating BVDV. This study utilized Madin-Darby bovine kidney (MDBK) cells as a model to investigate the antiviral effects of melatonin against Bovine Viral Diarrhea Virus (BVDV) and its connection with endoplasmic reticulum (ER) stress. Our results show that melatonin can suppress BVDV proliferation in MDBK cells by modulating the endoplasmic reticulum (ER) stress-mediated NF-κB pathway and autophagy. Specifically, melatonin alleviated ER stress, inhibited the activation of IκBα and p65, regulated autophagy, and reduced the expression levels of pro-inflammatory cytokines. Further, when we treated BVDV-infected cells with the ER stress inducer thapsigargin, it led to significant activation of the NF-κB pathway and autophagy. Conversely, treating the cells with the ER stress inhibitor 4-phenylbutyric acid reversed these effects. These findings suggest that melatonin exerts its antiviral effects primarily through the PERK-eIF2α-ATF4 of ER stress-mediated NF-κB pathway and autophagy. Overall, our study underscores the potential of melatonin as an effective protective and therapeutic option against BVDV, offering insights into its anti-infective mechanisms.

FOXA1-dependent PUS1 regulates EIF3b stability in a non-enzymatic pathway mediating prostate cancer bone metastasis.

Bone metastasis is a significant contributor to the poor prognosis in prostate cancer. Recent evidence highlights the pivotal role of pseudouridine synthases in solid tumor progression, yet the specific enzyme driving prostate cancer metastasis remains unidentified. This study uncovers a novel regulatory mechanism of the FOXA1/PUS1/EIF3b signaling axis in prostate cancer bone metastasis. We identified elevated PUS1 expression in prostate cancer tissues, correlating with higher clinical grade and worse prognosis. Knockdown of PUS1 inhibited metastasis independently of its enzymatic activity, with EIF3b acting as a downstream effector, protected from ubiquitin-mediated degradation by PUS1. Overexpression of EIF3b countered the metastasis suppression due to PUS1 knockdown. Additionally, FOXA1 was shown to enhance PUS1 expression by binding to its promoter. Mogroside IV-E, a specific PUS1 inhibitor, demonstrated potent anti-metastatic effects by reducing PUS1 expression. Our findings highlight the FOXA1/PUS1/EIF3b axis as a critical mediator of prostate cancer bone metastasis and suggest that targeting this pathway could be a promising therapeutic strategy.

eIF6 deficiency regulates gut microbiota, decreases systemic inflammation, and alleviates atherosclerosis.

Altered composition of the gut microbiota affects immunity and metabolism. This study previously found that eIF6 gene knockdown changes the composition of the intestinal flora in the eIF6 gene knockdown mouse model. Lactobacillus acidophilus is significantly increased in the model. This study was designed to investigate the role of L. acidophilus in the pathogenesis of atherosclerosis. Transcriptomic data from 117 patients with coronary artery disease (CAD) and 79 healthy individuals were obtained. ApoE-/- and ApoE-/-/eIF6+/- mice on normal chow diet or a high-fat diet were treated for 16 weeks; eIF6 deficiency was evaluated atherosclerosis. ApoE-/- mice on normal chow diet or a high-fat diet were treated with L. acidophilus by daily oral gavage for 16 weeks. Moreover, one group was treated with lipopolysaccharide at 12 weeks. The levels of eIF6, RNASE3, and RSAD2 were notably higher in the patients with CAD than in the healthy individuals. eIF6 deficiency altered the composition of gut microbiota. eIF6 deficiency reduced the atherosclerotic lesion formation in ApoE-/-/eIF6+/- mice compared with the ApoE-/- mice. The microbial sequencing and metabolomics analysis demonstrated some beneficial bacterial (L. acidophilus, Ileibacterium, and Bifidobacterium) and metabolic levels significantly had deference in ApoE-/-/eIF6+/- mice compared with the ApoE-/- mice. Correlational studies indicated that L. acidophilus had close correlations with low-density lipoprotein cholesterol, lesion area, and necrotic area. L. acidophilus inhibited high-fat diet-induced inflammation and atherosclerotic lesion, increasing the expression of tight junction proteins (ZO-1 and claudin-1) and reducing the gut permeability. However, lipopolysaccharide reversed the protective effect of L. acidophilus against atherosclerosis. eIF6 deficiency protected against atherosclerosis by regulating the composition of gut microbiota and metabolites. L. acidophilus attenuated atherosclerotic lesions by reducing inflammation and increasing gut permeability.IMPORTANCEeIF6 deficiency modulates the gut microbiota and multiple metabolites in atherosclerotic ApoE-/- mice. L. acidophilus was reduced in the gut of atherosclerotic ApoE-/- mice, but administration of Lactobacillus acidophilus reversed intestinal barrier dysfunction and vascular inflammation. Our findings suggest that targeting individual species is a beneficial therapeutic strategy to prevent inflammation and atherosclerosis.