Demographic profile and outcome in primary pediatric brain tumors. A single tertiary institute experience in India

Introduction: Pediatric brain tumors are the most common tumor in children after hematological malignancies. There is very few data about the epidemiology of pediatric brain tumors in India. Methods - This was a prospective and retrospective study in pediatric patients who had undergone surgery in our institute (JIPMER,Pondicherry). 80 cases were recruited and followed up for minimum follow up period of 1 year. The demographic profile was analysed and IHC markers were done for embroyonal tumors and glioma. Result(s): Pediatric brain tumors was equally distributed among male and females. (1:1) .Mean age of presentation was 10 years . 27.5 % of our cases were embryonal tumors,low grade glioma (16.25 % ) ,high grade glioma ( 12.5 % ) ,ependymoma and craniopharyngioma comprised 15 % of our cases each. Medulloblastoma comprised 23.75 % of cases Out of which 31.5 % had craniospinal metastasis at time of diagnosis. The most common location of SHH pathway medulloblastoma was cerebellar hemisphere and non WNT/non SHH was fourth ventricle. 45.45 % of patients with high grade glioma had recurrence .50 % of ependymoma cases were infratentorial. we had 2 cases of ganglioglioma ,one in the midbrain and other in temporal lobe .Gross total resection was achieved in 30 % ,Subtotal resection in 46.25 % and partial resection in 20 % of our cases. Outcome of patients at the end of 1 year for low and high grade glioma, ependymoma and craniopharyngioma were similar to western literature. Two patients acquired COVID 19 and died while undergoing treatment. Molecular markers like INI1, LIN28 A was highly sensitive and specific for diagnosing atypical teratoid rhabdoid tumor (ATRT) and embryonal tumor with multilayered rosettes (ETMR )respectively. Conclusion(s): Our study emphasizes the need of standardized and systemic cancer registries in India. (Figure Presented).

Changes in the proteomics of exhaled breath condensate under the influence of inhaled hydrogen in patients with post-COVID syndrome.

Aim. To study the effect of inhalation therapy with an active hydrogen (AH) on the protein composition of exhaled breath condensate (EBC) in patients with post-COVID syndrome (PCS). Material and methods. This randomized controlled parallel prospective study included 60 patients after coronavirus disease 2019 (COVID-19) with PCS during the recovery period and clinical manifestations of chronic fatigue syndrome who received standard therapy according to the protocol for managing patients with chronic fatigue syndrome (CFS). The patients were divided into 2 groups: group 1 (main) - 30 people who received standard therapy and AH inhalations (SUISONIA, Japan) for 10 days, and group 2 (control) - 30 medical workers who received only standard therapy. Patients in both groups were comparable in sex and mean age. All participants in the study were sampled with EBC on days 1 and 10. Samples were subjected to tryptic digestion and high-performance liquid chromatography combined with tandem mass spectrometry analysis using a nanoflow chromatograph (Dionex 3000) in tandem with a high-resolution time-of-flight mass spectrometer (timsTOF Pro). Results. A total of 478 proteins and 1350 peptides were identified using high resolution mass spectrometry. The number of proteins in samples after AH therapy, on average, is 12% more than before treatment. An analysis of the distribution of proteins in different groups of patients showed that only half of these proteins (112) are common for all groups of samples and are detected in EBC before, after, and regardless of hydrogen therapy. In addition to the qualitative difference in the EBC protein compositions in different groups, quantitative changes in the concentration of 36 proteins (mainly structural and protective) were also revealed, which together made it possible to reliably distinguish between subgroups before and after treatment. It is worth noting that among these proteins there are participants of blood coagulation (alpha-1-antitrypsin), chemokine- and cytokine-mediated inflammation, and a number of signaling pathways (cytoplasmic actin 2), response to oxidative stress (thioredoxin), glycolysis (glyceraldehyde-3- phosphate dehydrogenase), etc. Conclusion. The use of hydrogen therapy can contribute to the switching of a number of physiological processes, which may affect the success of recovery in PCS patients. In particular, the obtained results indicate the activation of aerobic synthesis of adenosine triphosphate in mitochondria by hydrogen therapy, which correlates well with the decrease in the blood lactate level detected by laboratory studies. At the same time, this therapy can inhibit pro-inflammatory activity, negatively affecting the coagulation and signaling pathways of integrins and apoptosis, and, in addition, activate protective pathways, tricarboxylic acid cycle, FAS signaling, and purine metabolism, which may be essential for effective recovery after COVID-19.Copyright © 2023 Vserossiiskoe Obshchestvo Kardiologov. All rights reserved.

The regulation of host cytoskeleton during SARS-CoV-2 infection in the nervous system

The global economy and public health are currently under enormous pressure since the outbreak of COVID-19. Apart from respiratory discomfort, a subpopulation of COVID-19 patients exhibits neurological symptoms such as headache, myalgia, and loss of smell. Some have even shown encephalitis and necrotizing hemorrhagic encephalopathy. The cytoskeleton of nerve cells changes drastically in these pathologies, indicating that the cytoskeleton and its related proteins are closely related to the pathogenesis of nervous system diseases. In this review, we present the up-to-date association between host cytoskeleton and coronavirus infection in the context of the nervous system. We systematically summarize cytoskeleton-related pathogen-host interactions in both the peripheral and central nervous systems, hoping to contribute to the development of clinical treatment in COVID-19 patients.

Inhibition of exchange proteins directly activated by cAMP as a strategy for broad-spectrum antiviral development.

The recent SARS-CoV-2 and mpox outbreaks have highlighted the need to expand our arsenal of broad-spectrum antiviral agents for future pandemic preparedness. Host-directed antivirals are an important tool to accomplish this as they typically offer protection against a broader range of viruses than direct-acting antivirals and have a lower susceptibility to viral mutations that cause drug resistance. In this study, we investigate the exchange protein activated by cAMP (EPAC) as a target for broad-spectrum antiviral therapy. We find that the EPAC-selective inhibitor, ESI-09, provides robust protection against a variety of viruses, including SARS-CoV-2 and Vaccinia (VACV)-an orthopox virus from the same family as mpox. We show, using a series of immunofluorescence experiments, that ESI-09 remodels the actin cytoskeleton through Rac1/Cdc42 GTPases and the Arp2/3 complex, impairing internalization of viruses that use clathrin-mediated endocytosis (e.g. VSV) or micropinocytosis (e.g. VACV). Additionally, we find that ESI-09 disrupts syncytia formation and inhibits cell-to-cell transmission of viruses such as measles and VACV. When administered to immune-deficient mice in an intranasal challenge model, ESI-09 protects mice from lethal doses of VACV and prevents formation of pox lesions. Altogether, our finding shows that EPAC antagonists such as ESI-09 are promising candidates for broad-spectrum antiviral therapy that can aid in the fight against ongoing and future viral outbreaks.

Ultrastructural analysis and three-dimensional reconstruction of cellular structures involved in SARS-CoV-2 spread.

The cytoskeleton not only deals with numerous interaction and communication mechanisms at the cellular level but also has a crucial role in the viral infection cycle. Although numerous aspects of SARS-CoV-2 virus interaction at the cellular level have been widely studied, little has been reported about the structural and functional response of the cytoskeleton. This work aims to characterize, at the ultrastructural level, the modifications in the cytoskeleton of infected cells, namely, its participation in filopodia formation, the junction of these nanostructures forming bridges, the viral surfing, and the generation of tunnel effect nanotubes (TNT) as probable structures of intracellular viral dissemination. The three-dimensional reconstruction from the obtained micrographs allowed observing viral propagation events between cells in detail for the first time. More profound knowledge about these cell-cell interaction models in the viral spread mechanisms could lead to a better understanding of the clinical manifestations of COVID-19 disease and to find new therapeutic strategies.

Functional proteomic profiling links deficient DNA clearance with increased mortality in individuals with severe COVID-19 pneumonia.

The factors that influence survival during severe infection are unclear. Extracellular chromatin drives pathology, but the mechanisms enabling its accumulation remain elusive. Here, we show that in murine sepsis models, splenocyte death interferes with chromatin clearance through the release of the DNase I inhibitor actin. Actin-mediated inhibition was compensated by upregulation of DNase I or the actin scavenger gelsolin. Splenocyte death and neutrophil extracellular trap (NET) clearance deficiencies were prevalent in individuals with severe COVID-19 pneumonia or microbial sepsis. Activity tracing by plasma proteomic profiling uncovered an association between low NET clearance and increased COVID-19 pathology and mortality. Low NET clearance activity with comparable proteome associations was prevalent in healthy donors with low-grade inflammation, implicating defective chromatin clearance in the development of cardiovascular disease and linking COVID-19 susceptibility to pre-existing conditions. Hence, the combination of aberrant chromatin release with defects in protective clearance mechanisms lead to poor survival outcomes.

SMARCA4-DEFICIENT UNDIFFERENTIATED TUMOR: A RARE THORACIC MALIGNANCY

SESSION TITLE: Rare Malignancies SESSION TYPE: Case Reports PRESENTED ON: 10/17/2022 03:15 pm - 04:15 pm INTRODUCTION: SMARCA4 deficient undifferentiated tumors (SMARCA4-DUT) are rare and aggressive neoplasms that are most commonly encountered in young male smokers and portend a poor prognosis (1,2). They are characterized by loss of SMARCA4, a subunit of chromatin remodeling complexes, and loss of the tumor suppressor brahma-related gene 1 (BRG1). We present a case of an elderly female with an extensive smoking history who was diagnosed with SMARCA4-DUT. CASE PRESENTATION: An 84 year old female with approximately 70 pack year smoking history, emphysema, ischemic cardiomyopathy, and coronary artery disease, presented to the emergency room with upper abdominal pain which started one day prior to admission. She endorsed an unintentional 10 pound weight loss in the past two months. The patient was admitted for an incarcerated ventral hernia for which she underwent repair. Of note, one and a half years ago, she was found to have a right lower lobe 7mm nodule but was unable to follow up due to the COVID pandemic. On this admission, a CT chest revealed a 4.2 x 3.8 x 3.7cm mediastinal mass and subcarincal lymphadenopathy. She underwent an EBUS with biopsy of the mediastinal mass and subcarinal lymph node. Cytology showed highly atypical epitheloid cells, concerning for a neoplasm with neuroendocrine differentiation and granulomas. Given the high suspicion for malignancy, she had a PET CT (figure 1) which showed FDG activity (SUV 11) in the mass with areas of necrosis and was referred to thoracic surgery. She underwent thoracoscopy with mediastinal mass resection and lymph node dissection and pathology showed diffuse sheets of epithelioid cells with large foci of necrosis. Neoplastic cells showed preserved INI (SMARCB1) expression, non-reactivity for NUT, and complete loss of BRG1 (SMARCA4) expression, consistent with a SMARCA4-DUT with positive margins (figure 2). She was referred to Radiation Oncology with plans to pursue further therapy thereafter. DISCUSSION: SMARCA4-DUT is a new and distinctive clinicopathological entity of aggressive thoracic tumors (1). The novelty of this class of tumors poses challenges in terms of treatment. Immune checkpoint inhibitors have shown compelling outcomes in case reports (3), however larger studies are needed to delineate optimal treatment regimens. CONCLUSIONS: SMARCA4-DUT are are rare but highly aggressive thoracic neoplasms. They present as large tumors and are smoking related. Prompt recognition may aid in early diagnosis. No definitive therapy exists but immunotherapy has shown promising results. Reference #1: Chatzopoulos, K., Boland, J.M. Update on genetically defined lung neoplasms: NUT carcinoma and thoracic SMARCA4-deficient undifferentiated tumors. Virchows Arch 478, 21–30 (2021). Reference #2: Roden AC. Thoracic SMARCA4-deficient undifferentiated tumor-a case of an aggressive neoplasm-case report. Mediastinum. 2021;5:39. Published 2021 Dec 25. Reference #3: Henon C, Blay JY, Massard C, Mir O, Bahleda R, Dumont S, Postel-Vinay S, Adam J, Soria JC, Le Cesne A. Long lasting major response to pembrolizumab in a thoracic malignant rhabdoid-like SMARCA4-deficient tumor. Ann Oncol. 2019 Aug 1;30(8):1401-1403. DISCLOSURES: No relevant relationships by Sathya Alekhya Bukkuri No relevant relationships by Erin Meier No relevant relationships by Mangalore Amith Shenoy No relevant relationships by Alexandra Zavin

Rotavirus Spike Protein VP4 Mediates Viroplasm Assembly by Association to Actin Filaments.

Rotavirus (RV) viroplasms are cytosolic inclusions where both virus genome replication and primary steps of virus progeny assembly take place. A stabilized microtubule cytoskeleton and lipid droplets are required for the viroplasm formation, which involves several virus proteins. The viral spike protein VP4 has not previously been shown to have a direct role in viroplasm formation. However, it is involved with virus-cell attachment, endocytic internalization, and virion morphogenesis. Moreover, VP4 interacts with actin cytoskeleton components, mainly in processes involving virus entrance and egress, and thereby may have an indirect role in viroplasm formation. In this study, we used reverse genetics to construct a recombinant RV, rRV/VP4-BAP, that contains a biotin acceptor peptide (BAP) in the K145-G150 loop of the VP4 lectin domain, permitting live monitoring. The recombinant virus was replication competent but showed a reduced fitness. We demonstrate that rRV/VP4-BAP infection, as opposed to rRV/wt infection, did not lead to a reorganized actin cytoskeleton as viroplasms formed were insensitive to drugs that depolymerize actin and inhibit myosin. Moreover, wild-type (wt) VP4, but not VP4-BAP, appeared to associate with actin filaments. Similarly, VP4 in coexpression with NSP5 and NSP2 induced a significant increase in the number of viroplasm-like structures. Interestingly, a small peptide mimicking loop K145-G150 rescued the phenotype of rRV/VP4-BAP by increasing its ability to form viroplasms and hence improve virus progeny formation. Collectively, these results provide a direct link between VP4 and the actin cytoskeleton to catalyze viroplasm assembly. IMPORTANCE The spike protein VP4 participates in diverse steps of the rotavirus (RV) life cycle, including virus-cell attachment, internalization, modulation of endocytosis, virion morphogenesis, and virus egress. Using reverse genetics, we constructed for the first time a recombinant RV, rRV/VP4-BAP, harboring a heterologous peptide in the lectin domain (loop K145-G150) of VP4. The rRV/VP4-BAP was replication competent but with reduced fitness due to a defect in the ability to reorganize the actin cytoskeleton, which affected the efficiency of viroplasm assembly. This defect was rescued by adding a permeable small-peptide mimicking the wild-type VP4 loop K145-G150. In addition to revealing a new role of VP4, our findings suggest that rRV harboring an engineered VP4 could be used as a new dual vaccination platform providing immunity against RV and additional heterologous antigens.

Actin cytoskeleton remodeling primes RIG-I-like receptor activation.

The current dogma of RNA-mediated innate immunity is that sensing of immunostimulatory RNA ligands is sufficient for the activation of intracellular sensors and induction of interferon (IFN) responses. Here, we report that actin cytoskeleton disturbance primes RIG-I-like receptor (RLR) activation. Actin cytoskeleton rearrangement induced by virus infection or commonly used reagents to intracellularly deliver RNA triggers the relocalization of PPP1R12C, a regulatory subunit of the protein phosphatase-1 (PP1), from filamentous actin to cytoplasmic RLRs. This allows dephosphorylation-mediated RLR priming and, together with the RNA agonist, induces effective RLR downstream signaling. Genetic ablation of PPP1R12C impairs antiviral responses and enhances susceptibility to infection with several RNA viruses including SARS-CoV-2, influenza virus, picornavirus, and vesicular stomatitis virus. Our work identifies actin cytoskeleton disturbance as a priming signal for RLR-mediated innate immunity, which may open avenues for antiviral or adjuvant design.

Enterogenous Cyst and Glioblastoma: A Brief Histopathological Review of Two Uncommon Cystic Lesions of the Central Nervous System

Intracranial cystic lesions are common findings in cerebral imaging and might represent a broad spectrum of conditions. These entities can be divided into nonneoplastic lesions, comprising Rathke cleft cyst, arachnoid cyst, and colloid cyst, as well as neoplastic lesions, including benign and malignant components of neoplasms such as pilocytic astrocytoma, hemangioblastoma, and ganglioglioma. Surgical resection and histological evaluation are currently the most effective methods to classify cysts of the central nervous system. The authors report two uncommon cases presenting as cystic lesions of the encephalic parenchyma-a enterogenous cyst and a glioblastoma-and discuss typical histological findings and differential diagnosis.

Oleic acid-induced acute lung injury in Ob/Ob mice fed with high-fat-diet exacerbate bile acid uptake and liver injury that was reversed by antagonizing their entry

Background and aims: Acute respiratory distress syndrome (ARDS) is a serious complication of COVID-19 and present in a large percentage of COVID-19 deaths. Many studies suggest that people with obesity are at increased risk of severe COVID-19, however, mechanism on liver-lung axis remains unknown. We aimed to evaluate whether bile acid (BAs) trafficking interfere with acute lung injury (ALI) in animal model with obesity. Method: Leptin deficient (ob/ob) mice fed with high-fat-diet (Ob/Ob HFD) were i.p injected with oleic acid (OA) to induce ALI. To modulate BAs uptake, mice were i.p treated with neutralizing antibody for sodium taurocholate co-transporting polypeptide (NTCP;BAs-transporter). Broncho-alveolar lavage fluid (BALF), lungs, livers and serum were obtained from mice and assessed for inflammatory (HandE staining, ALT and pro-inflammatory panel of cytokines), fibrosis (Sirius red staining, a-smooth muscle actin, collagen and fibronectin) and metabolic (BAs, cholesterol, triglyceride, glucose tolerance test (GTT) and fasting blood sugar (FBS)) profiles. In addition, alveolarcapillary membrane injury of surfactant D (SP-D) and the receptor for advanced glycation end-products (RAGE). BAs trafficking were assessed in primary lung cells and their impact on proliferation and apoptosis were evaluated. Results: Compared to WT-littermates, OA-induced lung injury and was worsened in the in the Ob/Ob HFD in the histopathology outcome. In addition, BALF of the Ob/Ob HFD showed elevated levels of BAs (3- fold;P = 0.002) associated with increased GM-CSF, INF-g, IL-1, IL-6 and IL-8 (p < 0.01). Moreover, Ob/Ob HFD with OA showed elevated serum levels in liver enzymes, lipids, glucose and metabolic markers (p < 0.01). In addition, Ob/Ob HFD livers showed an exacerbated fibrosis profile. NTCP neutralizing antibody in Ob/Ob HFD while inhibited BAs uptake/trafficking in both primary alveolar type II (BALF showed 4-fold increase in BAs) and primary hepatocytes (serum showed 3-fold increase in BAs). SP-D, RAGE and serum metabolic markers were suppressed to normal in line with enhance lung and liver histology and maintaining cell viability. Conclusion: Modulation of BAs trafficking from the liver of obese mice to the lungs could be an important step in the pathogenesis of ALI. Antagonizing BAs uptake may suggest a therapeutic strategy in improving liver-lung axis.

Saponin-based PAK-1 inhibitors as promising agents for struggle against SARS-CoV-2 infection

The serine/threonine p21-activating PAK kinases which act as important mediators of the Rho family of GTPases (Rho GTPases) Cdc42ĝ€¢GTP and Racĝ€¢GTP. PAK1 is one of the key molecules in the regulation of cytoskeletal actin assembly, phenotypic signaling, gene expression, and directly affects many cellular processes such as cell motility, invasion, metastasis, cell growth, angiogenesis, cell cycle progression. To date, several sulphated steroidal saponins have been reported to block the PAK1-dependent growth of A549 lung cancer. In this study, we investigated molecular interactions of N-triterpene saponins and PAK1 in silico molecular docking, and further evaluated the binding affinities. Molecular docking simulation was performed through AutoDock 4.2.2. an automated docking tool. We found that N-triterpene saponin 2 had the higher binding affinity towards PAK1 targeted protein. To the best of our knowledge, no report on N-triterpene saponins as a PAK1 inhibitor. © 2022 ACM.

GLOMERULAR HYPERFILTRATION MAY CONTRIBUTE TO RENAL TROPISM AND KIDNEY INJURY IN COVID-19 BY UPREGULATING ACE2 IN HUMAN PODOCYTES

Objective: Apart from the respiratory system, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can potentially infect multiple other organs including podocytes in the kidney. The latter play a crucial role in glomerular filtration. Podocytes can be damaged by increased fluid flow shear stress (FFSS) of the ultrafiltrate in Bowman's space in the setting of glomerular hyperfiltration that occurs in disease states such as hypertension, diabetes or in several forms of chronic kidney disease. These conditions are associated with an increased risk of a more severe course of coronavirus disease 2019 (COVID-19) and mortality. Design and method: To assess the susceptibility of human podocytes (hPC) for SARS-CoV-2 infection in the context of hyperfiltration in vitro, we used a recently established model system (Streamer Shear Stress Device)) to mimic hyperfiltration by exposing hPC to increased FFSS of 1 dyne/cm2 for 2 h. In this setting we nalysed the effects of FFSS on mRNA expression of angiotensin I-converting enzyme 2 (ACE2) as the pivotal entry receptor for SARS-CoV-2 infection in hPC. Moreover, other potential critical host cell factors including transmembrane serine protease 2 (TMPRSS2), furin (FURIN), and neuropilin 1 (NRP1) were also assessed in parallel with changes of the F-actin fiber structure, i.e. an important cytoskeletal marker in hPC. Results: Under control conditions, hPC displayed long, parallel F-actin fibers crossing the entire cell body. After FFSS, an enrichment of cells that express F-actin in a cortically condensed pattern near the cell membrane was observed. FFSS induced a significant upregulation of ACE2 expression (about twofold) and of all other nalysed SARS-CoV-2 entry factors in hPC (p < 0.05, respectively compared to control conditions, Figure 1 with data plotted as log2fold change [FC]). Conclusions: Our data support a potential link between glomerular hyperfiltration, podocyte damage and renal tropism of SARS-CoV-2 that may contribute to kidney damage including albuminuria development in COVID-19 patients.

Interactive Web-Based Lung Cell Atlases Lower Barriers to Transcriptomic Data Sharing, Mining and Dissemination

Rationale: Recent advancements in sequencing technologies have led to a substantial increase in the scale and resolution of transcriptomic data. Despite this progress, accessibility to this data, particularly among those who are coming from non-computational backgrounds is limited. To facilitate improved access and exploration of our single-cell RNA sequencing data, we generated several data sharing, mining and dissemination portals to accompany our idiopathic pulmonary fibrosis (IPF), chronic obstructive pulmonary disease (COPD), and lung endothelial cells (Lung EC) cell atlases. Descriptions and links of each website can be found here: https://medicine.yale.edu/lab/kaminski/research/atlas/. Methods: Each interactive data mining website is coded in the R language using the Shiny package and is hosted by Shinyapps.io. Percell expression data for each website is stored on a MySQL database hosted by Amazon Web Services (AWS). Time-associated website engagement statistics and gene query information is collected for each website using a combination of Google Analytics and a gene search table stored on our MySQL database. User exploration of available data is facilitated through several easy-touse visualization tools available on each website. Results: Website usage statistics since the publication of each website shows that 9,772 unique users from 56 countries and five continents have accessed at least one of the three websites. At the time of writing, 300,748 total queries have been made for 15,627 unique genes across the websites. The top five searched genes for the IPF Cell Atlas are CD14, ACE2, ACTA2, IL11 and MUC5B while for the COPD Cell Atlas they are FAM13A, MIRLET7BHG, HHIP, ISM1 and DDT. Finally, the top searched genes for the Lung Endothelial Cell Atlas are BMPR2, PECAM1, EDNRB, APLNR and PROX1. Of note, interaction with the IPF Cell Atlas increased dramatically at the start of the COVID-19 pandemic, with queries for the ACE2 gene, the putative binding receptor for the SARS-CoV-2 virus, increasing substantially at the pandemic's onset in the United States. Conclusions: Usage statistics, gene query information and feedback from users, both within academia and industry, have shown broad engagement with our websites by individuals across computational and non-computational backgrounds. We envision widespread adoption of web-based portals similar to ours will facilitate novel discoveries within these complex datasets and new scientific collaborations.

The mammalian endocytic cytoskeleton.

Clathrin-mediated endocytosis (CME) is the major route through which cells internalise various substances and recycle membrane components. Via the coordinated action of many proteins, the membrane bends and invaginates to form a vesicle that buds off-along with its contents-into the cell. The contribution of the actin cytoskeleton to this highly dynamic process in mammalian cells is not well understood. Unlike in yeast, where there is a strict requirement for actin in CME, the significance of the actin cytoskeleton to mammalian CME is variable. However, a growing number of studies have established the actin cytoskeleton as a core component of mammalian CME, and our understanding of its contribution has been increasing at a rapid pace. In this review, we summarise the state-of-the-art regarding our understanding of the endocytic cytoskeleton, its physiological significance, and the questions that remain to be answered.

ROLE of ACTIN REGULATORS in HIV-1, IAV, & SARS-CoV-2 VIRUS-LIKE PARTICLES PRODUCTION

Background: Human immunodeficiency virus (HIV) and Influenza A virus (IAV) remain a global health concern. Further, emergence of novel coronavirus SARS-CoV-2, which rapidly became global pandemic, increases the concern in biomedical research field for antiviral treatment. To develop new antiviral therapy, we must need to understand the molecular and cellular mechanisms involved in assembly and replication. It is known for some viruses (HIV and IAV) that the host actin cytoskeleton has been involved in various stages of the virus life cycle. Regulation of actin cytoskeleton requires several actin binding proteins, which organize the actin filaments (F-actin) into higher order structures such as actin bundles, branches, filopodia and microvilli, for further assistance in viral particle production. Thus, our objective for this work is to understand the role of these actin regulator proteins, like cofilin and one of its cofactor WDR1, in viral particle assembly and release. Methods: Here we used a combination of different experimental methods like RNA interference, immunoblot, immunoprecipitation, immunofluorescence coupled to confocal and STED fluorescence microscopy. In order to study only virus release, and bypass viral entry, we set up a minimal system for virus-like particles production in transfected cells, giving HIV-1 Gag-VLP, Influenza M1-VLP and SARS-CoV-2 MNE-VLP (developed by D. Muriaux lab). For image analysis, we used Image J software. Statistical analysis was performed with non-parametric t-tests or one-way Anova test. Results: Using siRNA strategy, we have shown that upon knock down of actin protein cofilin or WDR1, HIV-1 and IAV particles production increases in contrario to SARS-CoV-2 VLP release. Further, using immunoprecipitation, we report that HIV-1 Gag is able to form an intracellular complex with WDR1 and cofilin. Similarly, IAV-M1, which like HIV Gag-MA binds with plasma membrane phospholipids, is able to form an intracellular complex with cofilin. These results suggested that virus budding from the host cell plasma membrane seemed restricted by the cofilin/WDR1 complex. Finally, using confocal/STED microscopy on cell producing VLP, we observed actin fibers rearrangement with cell protrusions, suggesting a role for actin in viral particles assembly and release. Conclusion: In conclusion, regulators of actin dynamic are involved in HIV-1 Gag, IAV-M1 and SARS-CoV-2 VLP production but play a differential role in assembly and release of these RNA enveloped viruses.

Nanoantidote for repression of acidosis pH promoting COVID-19 infection.

Acidosis, such as respiratory acidosis and metabolic acidosis, can be induced by coronavirus disease 2019 (COVID-19) infection and is associated with increased mortality in critically ill COVID-19 patients. It remains unclear whether acidosis further promotes SARS-CoV-2 infection in patients, making virus removal difficult. For antacid therapy, sodium bicarbonate poses great risks caused by sodium overload, bicarbonate side effects, and hypocalcemia. Therefore, new antacid antidote is urgently needed. Our study showed that an acidosis-related pH of 6.8 increases SARS-CoV-2 receptor angiotensin-converting enzyme 2 (ACE2) expression on the cell membrane by regulating intracellular microfilament polymerization, promoting SARS-CoV-2 pseudovirus infection. Based on this, we synthesized polyglutamic acid-PEG materials, used complexation of calcium ions and carboxyl groups to form the core, and adopted biomineralization methods to form a calcium carbonate nanoparticles (CaCO3-NPs) nanoantidote to neutralize excess hydrogen ions (H+), and restored the pH from 6.8 to approximately 7.4 (normal blood pH). CaCO3-NPs effectively prevented the heightened SARS-CoV-2 infection efficiency due to pH 6.8. Our study reveals that acidosis-related pH promotes SARS-CoV-2 infection, which suggests the existence of a positive feedback loop in which SARS-CoV-2 infection-induced acidosis enhances SARS-CoV-2 infection. Therefore, antacid therapy for acidosis COVID-19 patients is necessary. CaCO3-NPs may become an effective antacid nanoantidote superior to sodium bicarbonate.

Abstracts for the 260th Otago Medical School Research Society Masters/ Honours Speakers Awards

The proceedings contain 8 papers. The topics discussed include: an exploration of mental health promotion in Aotearoa New Zealand: a qualitative study;vaccination, vaccine hesitancy and COVID-19 in New Zealand, 2018-2021;infra-slow pink noise stimulation can increase default-mode network activity in individuals with early Alzheimer's disease;agmatine attenuates actin dynamic alteration and synaptic dysfunction in aged rats;estrogen receptor alpha activation stimulates the Coolidge effect but has no effect on the sexual refractory period of estrogen-deprived male rats;and dissecting the receptor signaling events responsible for the immune suppressive and immune stimulatory effects of IL-10.

Research on the mechanism of berberine in the treatment of COVID-19 pneumonia pulmonary fibrosis using network pharmacology and molecular docking.

Purpose Pulmonary fibrosis caused by COVID-19 pneumonia is a serious complication of COVID-19 infection, there is a lack of effective treatment methods clinically. This article explored the mechanism of action of berberine in the treatment of COVID-19 (Corona Virus Disease 2019, COVID-19) pneumonia pulmonary fibrosis with the help of the network pharmacology and molecular docking. Methods We predicted the role of berberine protein targets with the Pharmmapper database and the 3D structure of berberine in the Pubchem database. And GeneCards database was used in order to search disease target genes and screen common target genes. Then we used STRING web to construct PPI interaction network of common target protein. The common target genes were analyzed by GO and KEGG by DAVID database. The disease-core target gene-drug network was established and molecular docking was used for prediction. We also analyzed the binding free energy and simulates molecular dynamics of complexes. Results Berberine had 250 gene targets, COVID-19 pneumonia pulmonary fibrosis had 191 gene targets, the intersection of which was 23 in common gene targets. Molecular docking showed that berberine was associated with CCl2, IL-6, STAT3 and TNF-α. GO and KEGG analysis reveals that berberine mainly plays a vital role by the signaling pathways of influenza, inflammation and immune response. Conclusion Berberine acts on TNF-α, STAT3, IL-6, CCL2 and other targets to inhibit inflammation and the activation of fibrocytes to achieve the purpose of treating COVID-19 pneumonia pulmonary fibrosis.