Clinical Manifestations and Epigenetic Regulation of Oral Herpesvirus Infections

Network pharmacology integrated molecular docking of fucoidan against oral cancer and in vitro evaluation- A study using GEO datasets

Oral cancer is a widespread health concern in rural India due to a lack of awareness, delayed diagnosis and limited access to affordable treatment options. The current chemotherapy has notable side effects, underscoring the need for new drug candidates with improved bioavailability and specificity. In this current research, fucoidan, a sulphated polysaccharide, was extracted from the brown algae Spatoglossum asperum, and shown to be cytotoxic in vitro against oral cancer cells (KB cell line) at an IC50 of 107.76 µg/ml, suggesting its potential as a drug candidate. This study further aimed to explore the potential therapeutic implications of fucoidan in managing oral cancer using network pharmacology. PharmMapper, Comparative Toxicogenomics Database and SuperPred were initially used to identify fucoidan protein targets. The identified targets were further screened against Gene Expression Omnibus (GSE23558, GSE25099 and GSE146483), OMIM, TCGA and GeneCards datasets to identify oral cancer-specific protein targets. The interactions between the selected proteins were visualised using STRING and Cytoscape. Subsequently, Database for Annotation, Visualization and Integrated Discovery was used for gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis of candidate targets. The cancer-related network was assessed using CancerGeneNet, while life expectancy based on the expression of the top 10 CytoHubba ranked hub genes was evaluated using Kaplan-Meier plots. Finally, EGFR, AKT1, HSP90AA1 and SRC were selected for docking and molecular dynamics simulation with fucoidan, using Maestro and GROMACS, respectively.Communicated by Ramaswamy H. Sarma.

Herpesviruses and SARS-CoV-2: Viral Association with Oral Inflammatory Diseases

The oral cavity is a niche for diverse microbes, including viruses. Members of the Herpesviridae family, comprised of dsDNA viruses, as well as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), an ssRNA virus, are among the most prevalent viruses infecting the oral cavity, and they exhibit clinical manifestations unique to oral tissues. Viral infection of oral mucosal epithelia triggers an immune response that results in prolonged inflammation. The clinical and systemic disease manifestations of HHV have been researched extensively, and several recent studies have illuminated the relationship between HHV and oral inflammatory diseases. Burgeoning evidence suggests the oral manifestation of SARS-CoV-2 infection includes xerostomia, dysgeusia, periodontal disease, mucositis, and opportunistic viral and bacterial infections, collectively described as oral post-acute sequelae of COVID-19 (PASC). These diverse sequelae could be a result of intensified immune responses initially due to the copious production of proinflammatory cytokines: the so-called "cytokine storm syndrome", facilitating widespread oral and non-oral tissue damage. This review explores the interplay between HHV, SARS-CoV-2, and oral inflammatory diseases such as periodontitis, endodontic disease, and peri-implantitis. Additionally, the review discusses proper diagnostic techniques for identifying viral infection and how viral diagnostics can lead to improved overall patient health.

Nasal Herpes Simplex With Infraorbital Neuralgia: A Rare Presentation

Facial herpes is a form of herpes simplex type I infection and presents with characteristic vesicular lesion around the perioral region. Nasal herpes, a form of facial herpes is a rare presentation with only a few cases reported in the literature. Neuralgic pain in herpes simplex is usually experienced at the site of the lesion during or before the eruptive stage. Here, we are reporting a case where the patient with a herpes simplex lesion over the tip of her nose presented with pain over the infraorbital region, which is a region supplied by the infraorbital nerve, a branch of the maxillary division of the trigeminal nerve. Initially confused as a bacterial infection due to its unusual presentation and rarity of the condition, the patient was given anti-bacterial therapy, but on showing no relief in symptoms, the patient was treated with appropriate antiviral drugs, following which complete remission of the lesion was observed. The case highlights a rare site for a common condition and atypical presentation.

Kaposi's Sarcoma-Associated Herpesvirus Immediate Early Proteins Trigger FOXQ1 Expression in Oral Epithelial Cells, Engaging in a Novel Lytic Cycle-Sustaining Positive Feedback Loop

Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic gammaherpesvirus that can replicate in oral epithelial cells to promote viral transmission via saliva. To identify novel regulators of KSHV oral infection, we performed a transcriptome analysis of KSHV-infected primary human gingival epithelial (HGEP) cells, which identified the gene coding for the host transcription factor FOXQ1 as the top induced host gene. FOXQ1 is nearly undetectable in uninfected HGEP and telomerase-immortalized gingival keratinocytes (TIGK) cells but is highly expressed within hours of KSHV infection. We found that while the FOXQ1 promoter lacks activating histone acetylation marks in uninfected oral epithelial cells, these marks accumulate in the FOXQ1 promoter in infected cells, revealing a rapid epigenetic reprogramming event. To evaluate FOXQ1 function, we depleted FOXQ1 in KSHV-infected TIGK cells, which resulted in reduced accumulation of KSHV lytic proteins and viral DNA over the course of 4 days of infection, uncovering a novel lytic cycle-sustaining role of FOXQ1. A screen of KSHV lytic proteins demonstrated that the immediate early proteins ORF45 and replication and transcription activator (RTA) were both sufficient for FOXQ1 induction in oral epithelial cells, indicating active involvement of incoming and rapidly expressed factors in altering host gene expression. ORF45 is known to sustain extracellular signal-regulated kinase (ERK) p90 ribosomal s6 kinase (RSK) pathway activity to promote lytic infection. We found that an ORF45 mutant lacking RSK activation function failed to induce FOXQ1 in TIGK cells, revealing that ORF45 uses a shared mechanism to rapidly induce both host and viral genes to sustain lytic infection in oral epithelial cells. IMPORTANCE The oral cavity is a primary site of initial contact and entry for many viruses. Viral replication in the oral epithelium promotes viral shedding in saliva, allowing interpersonal transmission, as well as spread to other cell types, where chronic infection can be established. Understanding the regulation of KSHV infection in the oral epithelium would allow for the design of universal strategies to target the first stage of viral infection, thereby halting systemic viral pathogenesis. Overall, we uncover a novel positive feedback loop in which immediate early KSHV factors drive rapid host reprogramming of oral epithelial cells to sustain the lytic cycle in the oral cavity.

Advances in the oral microbiota and rapid detection of oral infectious diseases

Several studies have shown that the dysregulation of the oral microbiota plays a crucial role in human health conditions, such as dental caries, periodontal disease, oral cancer, other oral infectious diseases, cardiovascular diseases, diabetes, bacteremia, and low birth weight. The use of traditional detection methods in conjunction with rapidly advancing molecular techniques in the diagnosis of harmful oral microorganisms has expanded our understanding of the diversity, location, and function of the microbiota associated with health and disease. This review aimed to highlight the latest knowledge in this field, including microbial colonization; the most modern detection methods; and interactions in disease progression. The next decade may achieve the rapid diagnosis and precise treatment of harmful oral microorganisms.

Oxidative stress and inflammation regulation of sirtuins: New insights into common oral diseases

Sirtuins are a family of nicotinamide adenine dinucleotide (NAD)⁺-dependent histone deacetylases, comprising seven members SIRT1-SIRT7. Sirtuins have been extensively studied in regulating ageing and age-related diseases. Sirtuins are also pivotal modulators in oxidative stress and inflammation, as they can regulate the expression and activation of downstream transcriptional factors (such as Forkhead box protein O3 (FOXO3a), nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor-kappa B (NF-κB)) as well as antioxidant enzymes, through epigenetic modification and post-translational modification. Most importantly, studies have shown that aberrant sirtuins are involved in the pathogenesis of infectious and inflammatory oral diseases, and oral cancer. In this review, we provide a comprehensive overview of the regulatory patterns of sirtuins at multiple levels, and the essential roles of sirtuins in regulating inflammation, oxidative stress, and bone metabolism. We summarize the involvement of sirtuins in several oral diseases such as periodontitis, apical periodontitis, pulpitis, oral candidiasis, oral herpesvirus infections, dental fluorosis, and oral cancer. At last, we discuss the potential utilization of sirtuins as therapeutic targets in oral diseases.

The role of Herpes Simplex Virus type 1 in oral diseases in children

Relevance. Herpes virus infections are the most common and poorly controllable viral infections. There are many difficulties in herpetic lesion verification and treatment in dental practice.

Purpose. The study aimed to present the results of a foreign publication investigation on the role of herpes simplex virus type 1 in the development of oral diseases in children.

Material and methods. Foreign scientific articles about the oral HSV-1 infections published from 2018 to 2022 formed the basis for the study. The study searched the publications on PubMed and Google Scholar bases.

Results. The article presents the newest data on the prevalence, clinical characteristics and diagnosis of oral HSV infection in children. Primary herpetic gingivostomatitis (PHGS), chronic recurrent herpetic gingivostomatitis, chronic recurrent herpes labialis are the main clinical presentations of herpes infection diagnosed in a dental practice. Primary herpetic gingivostomatitis is very common in children aged six months to fve years and occurs in newborns from 2 to 43 days of life. Modern virology success can improve diagnosis and treatment of oral herpetic lesions.

Conclusion. Primary herpetic gingivostomatitis is an acute infectious disease that requires the joint attention of a general practitioner and a dentist to ensure comprehensive treatment.

Debulking SARS-CoV-2 in saliva using angiotensin converting enzyme 2 in chewing gum to decrease oral virus transmission and infection

To advance a novel concept of debulking virus in the oral cavity, the primary site of viral replication, virus-trapping proteins CTB-ACE2 were expressed in chloroplasts and clinical-grade plant material was developed to meet FDA requirements. Chewing gum (2 g) containing plant cells expressed CTB-ACE2 up to 17.2 mg ACE2/g dry weight (11.7% leaf protein), have physical characteristics and taste/flavor like conventional gums, and no protein was lost during gum compression. CTB-ACE2 gum efficiently (>95%) inhibited entry of lentivirus spike or VSV-spike pseudovirus into Vero/CHO cells when quantified by luciferase or red fluorescence. Incubation of CTB-ACE2 microparticles reduced SARS-CoV-2 virus count in COVID-19 swab/saliva samples by >95% when evaluated by microbubbles (femtomolar concentration) or qPCR, demonstrating both virus trapping and blocking of cellular entry. COVID-19 saliva samples showed low or undetectable ACE2 activity when compared with healthy individuals (2,582 versus 50,126 ΔRFU; 27 versus 225 enzyme units), confirming greater susceptibility of infected patients for viral entry. CTB-ACE2 activity was completely inhibited by pre-incubation with SARS-CoV-2 receptor-binding domain, offering an explanation for reduced saliva ACE2 activity among COVID-19 patients. Chewing gum with virus-trapping proteins offers a general affordable strategy to protect patients from most oral virus re-infections through debulking or minimizing transmission to others.

Release of HSV-1 Cell-Free Virions: Mechanisms, Regulation, and Likely Role in Human-Human Transmission

Herpes simplex virus type 1, or HSV-1, is a widespread human pathogen that replicates in epithelial cells of the body surface and then establishes latent infection in peripheral neurons. When HSV-1 replicates, viral progeny must be efficiently released to spread infection to new target cells. Viral spread occurs via two major routes. In cell-cell spread, progeny virions are delivered directly to cellular junctions, where they infect adjacent cells. In cell-free release, progeny virions are released into the extracellular milieu, potentially allowing the infection of distant cells. Cell-cell spread of HSV-1 has been well studied and is known to be important for in vivo infection and pathogenesis. In contrast, HSV-1 cell-free release has received less attention, and its significance to viral biology is unclear. Here, I review the mechanisms and regulation of HSV-1 cell-free virion release. Based on knowledge accrued in other herpesviral systems, I argue that HSV-1 cell-free release is likely to be tightly regulated in vivo. Specifically, I hypothesize that this process is generally suppressed as the virus replicates within the body, but activated to high levels at sites of viral reactivation, such as the oral mucosa and skin, in order to promote efficient transmission of HSV-1 to new human hosts.