Search Results (99)

Coxsackievirus B3 (CVB3) is a primary causative agent of viral myocarditis (VMC), which can lead to both acute and chronic cardiac inflammation accompanied by progressive heart failure and arrhythmias. Although CVB3 has been implicated in various forms of programmed cell death, whether it triggers necroptosis and the underlying mechanisms remains unclear. This study aimed to investigate the role and mechanism of CVB3-induced necroptosis and its effect on viral replication. Using both in vitro and in vivo models, we demonstrated that CVB3 infection significantly upregulates the expression of key necroptotic markers RIP1 and RIP3 in HeLa cells and mouse myocardial tissues. This upregulation was accompanied by elevated intracellular reactive oxygen species (ROS) levels and suppression of the Nrf2/HO-1 antioxidant pathway. Intervention with the necroptosis inhibitor Necrostatin-1 (Nec-1) or the ROS scavenger N-acetylcysteine (NAC) markedly attenuated cell death, suppressed viral replication, and ameliorated myocardial injury and inflammatory responses in infected mice. Mechanistically, CVB3 inhibits the Nrf2/HO-1 pathway, thereby inducing substantial ROS accumulation that promotes necroptosis. This effect can be reversed by NAC treatment. Our study reveals a novel mechanism through which CVB3 induces ROS-dependent necroptosis via the suppression of the Nrf2/HO-1 pathway, providing new insights into the pathogenesis of viral myocarditis and suggesting potential therapeutic strategies. Full article

Enteroviruses (EVs), particularly those within the species Enterovirus A and B, represent a significant global public health burden, especially in infants and young children. While often causing self-limiting hand, foot, and mouth disease (HFMD), certain serotypes can lead to severe neurological and cardiopulmonary complications. This comprehensive review focuses on the major pathogenic serotypes, including enterovirus A71 (EV-A71), coxsackievirus A16 (CV-A16), coxsackievirus A6 (CV-A6), coxsackievirus B3 (CV-B3), and enterovirus D68 (EV-D68). We began by reconstructing a phylogenetic tree based on VP1 protein sequences, elucidating the genetic relationships and evolutionary patterns among these serotypes, which underpin their diverse antigenicity and epidemiology. Building upon this genetic foundation, the review then provides a detailed synthesis of their distinct pathogenesis, highlighting the five-phase clinical progression from exanthematous phase to convalescence, and their unique tropisms for target organs such as the central nervous system and heart. Progressing to the molecular mechanisms, a critical component of this work is a systematic summary of the specific host receptors that mediate viral entry, including SCARB2 for EV-A71 and CV-A16, sialic acid and ICAM-5 for EV-D68, and CAR/CD55 for CV-B3, explaining the mechanistic basis for their tissue specificity and pathogenicity. Finally, to translate these insights into clinical applications, we critically evaluate the current landscape of vaccine development, noting the high efficacy (~90%) of inactivated EV-A71 vaccines in Asia and the significant global success of poliovirus vaccines, while also addressing the stark lack of cross-protective or licensed vaccines for other prevalent serotypes like CV-A16, CV-A6, and EV-D68. The review concludes that the high genetic diversity and serotype-specific immunity of enteroviruses pose a major challenge, necessitating a concerted shift towards the development of broad-spectrum vaccines and therapeutics informed by an integrated understanding of viral evolution, receptor usage, and pathogenesis. Full article

Nuclear factor of activated T cells 5 (NFAT5), an osmosensitive transcription factor, has been shown to protect against coxsackievirus B3 (CVB3)-induced myocarditis but is susceptible to cleavage by viral proteases. Identifying agents that upregulate NFAT5 may offer a novel antiviral strategy. Cyclodextrins, cyclic oligosaccharides that influence cellular osmolality, are promising candidates. In this study, we demonstrate that NFAT5 is critical for maintaining desmosomal integrity in cardiomyocytes. Cardiac-specific Nfat5-knockout mice showed a significant reduction in desmosomes, as observed by transmission electron microscopy. Furthermore, we identified desmoplakin (DSP), a structural desmosomal protein, as a direct transcriptional target of NFAT5, with reduced expression in Nfat5-knockout mouse hearts and NFAT5-knockdown HeLa cells. Notably, treatment with 5 mM cyclodextrin significantly upregulated NFAT5 expression with minimal cytotoxicity, restored DSP expression, and suppressed CVB3 replication by inhibiting viral RNA transcription, protein synthesis, and virion production. Additionally, cyclodextrin reduced mRNA levels of proinflammatory cytokines interleukin-1 beta and interleukin-8, indicating its potential role as an alleviator of excessive cytokine production. These findings identify NFAT5 as a key regulator of desmoplakin expression and prove cyclodextrin as a dual-functioning agent in counteracting cardiac damage through NFAT5-DSP-mediated protection of desmosome integrity and suppressing proinflammatory cytokine expression in CVB3-induced myocarditis. Full article

Coxsackievirus B3 (CV-B3) infection causes inflammatory conditions such as viral myocarditis and meningitis, and incidence rates are rising annually. While children are more likely to be affected by severe manifestations, the molecular basis of this age-dependent susceptibility is poorly understood. In this study, we used young Balb/c mice at three developmental stages (7-, 14-, and 30-day-old mice) to investigate CV-B3 pathogenesis. Our findings revealed that 7-day-old mice exhibited substantial infection susceptibility and pathological severity compared to older mice. Critically, an age-dependent analysis showed a progressive decline in the expression of CV-B3-binding Coxsackievirus and Adenovirus Receptor (CAR) splice variants (CAR1 and CAR2) at both the transcriptional and translational levels as the mice matured from 7 to 30 days. These receptor isoforms demonstrated a direct correlation with viral replication efficiency in younger hosts. Concurrently, aging was associated with a rise in non-binding CAR variants (CAR3 and CAR4). During CV-B3 infection, the abundance of CAR1/CAR2 in young mice facilitated accelerated viral proliferation, coupled with the hyperactivation of the NLRP3 inflammasome and the expansion of IL-17-producing γδT cells (γδT17 cells). This cascade triggered excessive production of proinflammatory cytokines (IL-1β, IL-18, and IL-17), culminating in pronounced inflammatory infiltrates within cardiac and cerebral tissues. These findings establish NLRP3 inflammasome dysregulation as a critical determinant of CV-B3-induced tissue damage and provide novel insights into the heightened susceptibility to CV-B infection during early life and its associated severe disease rates. Full article

The enterovirus Coxsackievirus B3 causes a range of serious health problems, including aseptic meningitis, myocarditis, and pancreatitis. Currently, Coxsackievirus B3 has no targeted antiviral treatments or vaccines, leaving supportive care as the primary management option. Understanding how Coxsackievirus B3 interacts with and alters the blood–brain barrier may help identify new therapies to combat this often-devastating infection. We reanalyzed a previously published RNA sequencing dataset for Coxsackievirus B3-infected human-induced pluripotent stem-cell-derived brain endothelial cells (iBECs) to examine how Coxsackievirus B3 altered mRNA expression. By integrating GSEA, EnrichR, and iLINCs-based perturbagen analysis, we present a novel, systems-level approach to uncover potential drug repurposing candidates for CVB3 infection. We found dynamic changes in host transcriptomic response to Coxsackievirus B3 infection at 2- and 5-day infection time points. Downregulated pathways included ribosomal biogenesis and protein synthesis, while upregulated pathways included a defense response to viruses, and interferon production. Using iLINCs transcriptomic analysis, MEK, PDGFR, and VEGF inhibitors were identified as possible novel antiviral therapeutics. Our findings further elucidate Coxsackievirus B3-associated pathways in (iBECs) and highlight potential drug repurposing candidates, including pelitinib and neratinib, which may disrupt Coxsackievirus B3 pathology at the blood–brain barrier (BBB). Full article

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer characterized by a dense desmoplastic stroma and a highly immunosuppressive tumor microenvironment (TME). The focal adhesion kinase (FAK), a non-receptor tyrosine kinase, is considered a critical regulator of various cellular processes involved in cancer development. FAK inhibitors (FAKi) have proven to be promising therapeutics for cancer treatment including for pancreatic cancer. As monotherapy, however, FAKi showed only a modest effect in clinical studies. In this study, we investigated the cytotoxicity of six FAKi (Defactinib, CEP-37440, VS-4718, VS-6062, Ifebemtinib and GSK2256098) used in clinical trials on five pancreatic tumor cell lines. We further examined whether their anti-tumor activity can be enhanced by combination with the oncolytic coxsackievirus B3 (CVB3) strain PD-H. IC₅₀ analyses identified Defactinib and CEP-37440 as the most potent inhibitors of tumor cell growth. VS-4718, VS-6062, and Ifebemtinib showed slightly lower activity, while GSK2256098 was largely ineffective. The combination of Defactinib, CEP-37440, VS-4718, and VS-6062 with PD-H resulted in varying effects on cytotoxicity, depending on the cell line and the specific FAKi, ranging from no enhancement to a pronounced increase. Using the Chou–Talalay method, we determined combination indices (CI), revealing synergistic, additive, but also antagonistic interactions between the respective FAKi and PD-H. Considering both oncolytic efficacy and the CI, the greatest enhancement in oncolytic activity was achieved when VS-4718 or CEP-37440 was combined with PD-H. These findings indicate that co-treatment with PD-H can potentiate the therapeutic activity of the selected FAKi and may represent a novel strategy to improve treatment outcomes in PDAC. Full article

Artemisia serotina Bunge represents one of the endemic Artemisia L. species in flora of Central Asia. There is scant information on the phytochemistry and biological activity of this species. The aim of the present study was to analyze the chemical composition of essential oil from A. serotina (ASEO) growing in south Kazakhstan, together with the determination of its biological activity. ASEO isolation was carried out by hydrodistillation according to the State Pharmacopoeia of the Republic of Kazakhstan. Analysis of GC/MS data revealed that the most characteristic components of ASEO were irregular monoterpenes from three families: santolinane, artemisane, and lavandulane. The major compound was santolina alcohol (34.6%). Antimicrobial activity was studied against the reference bacterial and fungal strains using the recommended methods, allowing for an estimation of MIC (minimum inhibitory concentration). ASEO was most effective against Candida albicans (MIC = 2 mg/mL), exerting fungicidal activity. Thw MIC for bacterial species was higher, i.e., 4–16 mg/mL. Antiviral activity was tested against Coxsackievirus B3 (CVB3) and Human Herpesvirus type 1 (HHV-1) propagated in VERO cells. No antiviral effect against either virus was found at an ASEO concentration of 0.25 mg/mL, but a noticeable decrease in the intensity of HHV-1-related cytopathic effects was observed. Anticancer activity studies included several cancer cell lines. Cytotoxicity, cell cycle, thiol levels, and cell vitality were analyzed. Among the cancer cell lines tested, the breast cancer T47-D cell line exhibited the highest sensitivity to ASEO (IC₅₀ = 40.81 ± 4.21 µg/mL at 24 h; IC₅₀ = 33.17 ± 2.11 µg/mL at 48 h). The anticancer effect was suggested to be mainly due to the induction of cytostatic effects, accompanied by a disturbance of the intracellular redox balance. The obtained data provide novel information on the unique chemical composition of ASEO from south Kazakhstan, representing a new chemotype. Its bioactivity, including promising antifungal and anticancer properties, was demonstrated for the first time. Full article

Inflammatory cardiomyopathy is a condition that is characterised by the presence of inflammatory cells in the myocardium, which can lead to a significant deterioration in cardiac function. The etiology of this condition involves multiple factors, both infectious and non-infectious causes. While it is primarily associated with viral infections, other potential causes include bacterial, protozoal, or fungal infections, as well as a wide variety of toxic substances and drugs, and systemic immune-mediated pathological conditions. In spite of comprehensive investigation, the presence of inflammatory cardiomyopathy accompanied by left ventricular dysfunction, heart failure or arrhythmia is indicative of an unfavourable outcome. The reasons for the occurrence of either favourable outcomes, characterised by the absence of residual myocardial injury, or unfavourable outcomes, marked by the development of dilated cardiomyopathy, in patients afflicted by the condition remain to be elucidated. The relative contributions of pathogenic agents, genomic profiles of the host, and environmental factors in disease progression and resolution remain subjects of ongoing discourse. This includes the determination of which viruses function as active inducers and which merely play a bystander role. It remains unknown which changes in the host immune profile are critical in determining the outcome of myocarditis caused by various viruses, including coxsackievirus B3 (CVB3), adenoviruses, parvoviruses B19 and SARS-CoV-2. The objective of this review is unambiguous: to provide a concise summary and comprehensive assessment of the extant evidence on the pathogenesis, diagnosis and treatment of myocarditis and inflammatory cardiomyopathy. Its focus is exclusively on virus-induced and virus-associated myocarditis. In addition, the extant lacunae of knowledge in this field are identified and the extant experimental models are evaluated, with the aim of proposing future directions for the research domain. This includes differential gene expression that regulates iron and lipid and metabolic remodelling. Furthermore, the current state of knowledge regarding the cardiovascular implications of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is also discussed, along with the open questions that remain to be addressed. Full article

Coxsackievirus B (CVB) infections, ranging from mild to severe diseases, lack specific antiviral treatments, underscoring the need for novel therapeutic strategies. Drug therapy is an important tool for controlling enterovirus infections, but clinically effective drugs do not currently exist, mainly due to the development of drug resistance. Combination therapy with two or more drugs has the potential to successfully inhibit viral infection more effectively than either drug alone as well as delay the development of resistance. This study explores the consecutive alternating administration (CAA) scheme in mice with CVB1 infection, utilizing double antiviral combinations consisting of pleconaril and MDL-860, with guanidine hydrochloride and oxoglaucine. The CAA combinations of pleconaril achieved a survival rate, in infected mice, of up to 59%, while the combinations of MDL-860 showed no significant effects. CAA reduced mortality, prolonged mean survival time (up to 5 days), and mitigated drug resistance compared to monotherapy or simultaneous administration. Monotherapeutic courses and daily administration of double combinations had no effect. Phenotypic characterization using the IC₅₀ marker of virus isolates from brain tissue of infected and treated mice was of particular importance for the evaluation of the CAA treatment scheme. The results show increased susceptibility of the virus isolates to the partner compounds in double CAA combinations. In contrast, virus isolates from the monotherapeutic groups manifested a diminished susceptibility to their respective compound, which signals the development of drug resistance. All data obtained prove the potential of the CAA scheme for the development of effective chemotherapy of enterovirus infections. Full article

Recently, we demonstrated that the oncolytic Coxsackievirus B3 (CVB3) strain PD-H can be efficiently adapted to resistant colorectal cancer cells through dose-dependent passaging in colorectal cancer cells. However, the method is time-consuming, which limits its clinical applicability. Here, we investigated whether the manufacturing time of the adapted virus can be reduced by replacing the dose-based passaging with volume-based passaging. For this purpose, the murine colorectal carcinoma cell line MC38, resistant to PD-H-induced lysis, was initially infected with PD-H at 0.1 multiplicity of infection (MOI). For subsequent passages, 15–30 µL of a 1:10 dilution of the cell culture supernatant was transferred to fresh MC38 cells early after virus-induced cell lysis became visible. By virus passage 10, complete cell lysis of MC38 cells was achieved. Sequencing of the passage 10 virus (P-10) revealed two nucleotide substitutions in the 5′ UTR and six amino acid changes in the viral polyprotein compared to the PD-H founder. P-10, however, consisted of a heterogeneous virus population. Therefore, the detected mutations were introduced into the cDNA of PD-H, from which the recombinant virus PD-MC38 was generated. PD-MC38 exhibited significantly enhanced replication and lytic activity in MC38 cells compared to PD-H, whereas its oncolytic activity in other colorectal cancer cell lines was comparable to or even lower than that of PD-H. These findings demonstrate that volume-based passaging is suitable to generate tumor cell-specific adapted PD-H. Moreover, compared to the dose-dependent passaging, volume-based passaging significantly reduced the time required to generate the adapted virus. Full article

During virus infection, the activation of the antiviral endoribonuclease, ribonuclease L (RNase L), by a unique ligand 2′-5′-oilgoadenylate (2-5A) causes the cleavage of single-stranded viral and cellular RNA targets, restricting protein synthesis, activating stress response pathways, and promoting cell death to establish broad antiviral effects. The immunostimulatory dsRNA cleavage products of RNase L activity (RL RNAs) recruit diverse dsRNA sensors to activate signaling pathways to amplify interferon (IFN) production and activate inflammasome, but the sensors that promote cell death are not known. In this study, we found that DEAH-box polypeptide 15 (DHX15) and retinoic acid-inducible gene I (Rig-I) are essential for apoptosis induced by RL RNAs and require mitochondrial antiviral signaling (MAVS), c-Jun amino terminal kinase (JNK), and p38 mitogen-activated protein kinase (p38 MAPK) for caspase-3-mediated intrinsic apoptosis. In RNase L-activated cells, DHX15 interacts with Rig-I and MAVS, and cells lacking MAVS expression were resistant to apoptosis. RL RNAs induced the transcription of genes for IFN and proinflammatory cytokines by interferon regulatory factor 3 (IRF-3) and nuclear factor kB (NF-kB), while cells lacking both DHX15 and Rig-I showed a reduced induction of cytokines. However, apoptotic cell death is independent of both IRF-3 and NF-kB, suggesting that cytokine and cell death induction by RL RNAs are uncoupled. The RNA binding of both DHX15 and Rig-I is required for apoptosis induction, and the expression of both single proteins in cells lacking both DHX15 and Rig-I is insufficient to promote cell death by RL RNAs. Cell death induced by RL RNAs suppressed Coxsackievirus B3 (CVB3) replication, and inhibiting caspase-3 activity or cells lacking IRF-3 showed that the induction of apoptosis directly resulted in the CVB3 antiviral effect, and the effects were independent of the role of IRF-3. Full article

Di(2-ethhylhexyl) phthalate (DEHP) is a common plastic rubberizer. DEHP leaches from plastic matrices and is under increasing scrutiny as numerous studies have linked it to negative human health manifestations. Coxsackievirus B3 (CVB) is a human pathogen that typically causes subclinical infections but can sometimes cause severe diseases such as pancreatitis, myocarditis, and meningoencephalitis. Though CVB infections are common, severe illness is relatively rare, and it is unclear what factors mediate disease severity. In this study, we sought to determine the effects that DEHP has on CVB infection in a variety of human cell types to evaluate whether this plastic-derived pollutant could represent a proviral environmental factor. Methods: HeLa cervical cancer cells, human induced pluripotent stem cell-derived brain-like endothelial cells (iBECs), and Caco-2 colon carcinoma cells were exposed to 40 µg/mL DEHP for 24 h prior to infecting with enhanced green fluorescent protein (EGFP)-expressing CVB. The severity of the infection was evaluated via fluorescence microscopy and flow cytometry-based viral EGFP detection, viral plaque assay on tissue culture media, and Western blotting to detect VP1 viral capsid protein. Interferon-associated proteins such as interferon regulatory factor (IRF) 3, IRF7, interferon-induced transmembrane (IFITM) 2, and IFITM3 were measured by Western blotting. The roles of IFITM2 and IFITM3 in the context of CVB infection were evaluated via siRNA silencing. Results: We found that DEHP drastically increased CVB infection in each of the cell types we tested, and, while the cellular processes underlying DEHP’s proviral properties were not entirely clear, we observed that DEHP may subvert CVB-induced interferon signaling and elevate levels of IFITMs, which appeared to bolster CVB infection. Conclusions: DEHP may represent a major environmental factor associated with the severity of CVB infection. Further understanding of how DEHP exacerbates infection may better elucidate its potential role as a proviral environmental factor. Full article

Four previously undescribed pentacyclic triterpenoid saponins, pannosides F–I (1–4), were isolated from the halophyte Aster tripolium L. (Tripolium pannonicum), and their chemical structures were elucidated using 1D and 2D NMR spectroscopy and mass spectrometry. Comprehensive structural analysis revealed the presence of distinct aglycone and glycosidic moieties, along with complex acylation patterns. The acyl chains of pannosides, 3-hydroxybutyrate (3-HB) residues, were derivatized with (S)- and (R)- phenylglycine methyl ester to resolve the absolute configurations of the chiral centers in 3-HB. Then, the acyl chain-containing saponins, pannosides were evaluated for their antiviral activities against enterovirus A71 (EV71), coxsackievirus B3 (CVB3), and rhinovirus 1B (HRV1B). Pannosides exhibited antiviral activities against HRV1B, EV71, and CVB3. These findings suggest that saponins from A. tripolium exhibit potential antiviral activities and could be further explored for their therapeutic applications. Full article

N6-methyladenosine (m⁶A) is the most prevalent internal RNA modification. Here, we demonstrate that coxsackievirus B3 (CVB3), a common causative agent of viral myocarditis, induces m⁶A modification primarily at the stop codon and 3′ untranslated regions of its genome. As a positive-sense single-stranded RNA virus, CVB3 replicates exclusively in the cytoplasm through a cap-independent translation initiation mechanism. Our study shows that CVB3 modulates the expression and nucleo-cytoplasmic transport of the m⁶A machinery components—METTL3, ALKBH5 and YTHDFs—resulting in increased m⁶A modifications that enhance viral replication. Mechanistically, this enhancement is mediated through YTHDF-driven stress granule (SG) formation. We observed that YTHDF proteins co-localize with human antigen R (HuR), a protein facilitating cap-independent translation, in SGs during early infection. Later in infection, YTHDFs are cleaved, suppressing SG formation. Notably, for the first time, we identified that during early infection CVB3’s RNA-dependent RNA polymerase (3D) and double-stranded RNA (dsRNA) are stored in SGs, co-localizing with HuR. This early-stage sequestration likely protects viral components for use in late-phase replication, when SGs are disrupted due to YTHDF cleavage. In summary, our findings reveal that CVB3-induced m⁶A modifications enhance viral replication by regulating YTHDF-mediated SG dynamics. This study provides a potential therapeutic strategy for CVB3-induced myocarditis. Full article

Pancreatic cancer is one of the deadliest cancers globally, with limited success from existing therapies, including chemotherapies and immunotherapies like checkpoint inhibitors for patients with advanced pancreatic ductal adenocarcinoma (PDAC). A promising new approach is the use of oncolytic viruses (OV), a form of immunotherapy that has been demonstrated clinical effectiveness in various cancers. Here we investigated the potential of the oncolytic coxsackievirus B3 strain (CVB3) PD-H as a new treatment for pancreatic cancer. In vitro, PD-H exhibited robust replication, as measured by plaque assays, and potent lytic activity, as assessed by XTT assays, in most pancreatic tumor cell lines, outperforming two other coxsackievirus strains tested, H3N-375/1TS and CVA21. Thus, H3N-375/1TS showed efficient replication and lytic efficiency in distinctly fewer tumor cell lines, while most tumor cells were resistant to CVA21. The oncolytic efficiency of the three OV largely correlated with mRNA expression levels of viral receptors and their ability to induce apoptosis, as measured by cleaved caspase 3/7 activity in the tumor cells. In a syngeneic mouse model with subcutaneous pancreatic tumors, intratumoral administration of PD-H significantly inhibited tumor growth but did not completely stop tumor progression. Importantly, no virus-related side effects were observed. Although pancreatic tumors respond to PD-H treatment, its therapeutic efficacy is limited. Combining PD-H with other treatments, such as those aiming at reducing the desmoplastic stroma which impedes viral infection and spread within the tumor, may enhance its efficacy. Full article