Preventive and therapeutic effects of a super-multivalent sialylated filamentous bacteriophage against the influenza virus.

The resurgence of influenza viruses as a significant global threat emphasizes the urgent need for innovative antiviral strategies beyond existing treatments. Here, we present the development and evaluation of a novel super-multivalent sialyllactosylated filamentous phage, termed t-6SLPhage, as a potent entry blocker for influenza A viruses. Structural variations in sialyllactosyl ligands, including linkage type, valency, net charge, and spacer length, were systematically explored to identify optimal binding characteristics against target hemagglutinins and influenza viruses. The selected SLPhage equipped with optimal ligands, exhibited exceptional inhibitory potency in in vitro infection inhibition assays. Furthermore, in vivo studies demonstrated its efficacy as both a preventive and therapeutic intervention, even when administered post-exposure at 2 days post-infection, under 4 lethal dose 50% conditions. Remarkably, co-administration with oseltamivir revealed a synergistic effect, suggesting potential combination therapies to enhance efficacy and mitigate resistance. Our findings highlight the efficacy and safety of sialylated filamentous bacteriophages as promising influenza inhibitors. Moreover, the versatility of M13 phages for surface modifications offers avenues for further engineering to enhance therapeutic and preventive performance.

Harnessing traditional Chinese medicine polysaccharides for combatting COVID-19.

With the global spread of COVID-19 posing ongoing challenges to public health systems, there is an ever-increasing demand for effective therapeutics that can mitigate both viral transmission and disease severity. This review surveys the landscape of polysaccharides derived from traditional Chinese medicine, acclaimed for their medicinal properties and potential to contribute to the COVID-19 response. We specifically focus on the capability of these polysaccharides to thwart SARS-CoV-2 entry into host cells, a pivotal step in the viral life cycle that informs transmission and pathogenicity. Moreover, we delve into the concept of trained immunity, an innate immune system feature that polysaccharides may potentiate, offering an avenue for a more moderated yet efficacious immune response against various pathogens, including SARS-CoV-2. Our comprehensive overview aims to bolster understanding of the possible integration of these substances within anti-COVID-19 measures, emphasizing the need for rigorous investigation into their potential applications and underlying mechanisms. The insights provided here strongly support ongoing investigations into the adjunctive use of polysaccharides in the management of COVID-19, with the anticipation that such findings could lead to a deeper appreciation and clearer elucidation of the antiviral potentials inherent in complex Chinese herbal remedies.

FGFR1-mediated enhancement of foot-and-mouth disease virus entry.

Foot-and-mouth disease virus (FMDV), a member of picornavirus, can enter into host cell via macropinocytosis. Although it is known that receptor tyrosine kinases (RTKs) play a crucial role in FMDV macropinocytic entry, the specific RTK responsible for regulating this process and the intricacies of RTK-mediated downstream signaling remain to be elucidated. Here, we conducted a screening of RTK inhibitors to assess their efficacy against FMDV. Our findings revealed that two compounds specifically targeting fibroblast growth factor receptor 1 (FGFR1) and FMS-like tyrosine kinase 3 (FLT3) significantly disrupted FMDV entry. Furthermore, additional evaluation through gene knockdown and overexpression confirmed the promotion effect of FGFR1 and FLT3 on FMDV entry. Interestingly, we discovered that the increasement of FMDV entry facilitated by FGFR1 and FLT3 can be ascribed to increased macropinocytic uptake. Additionally, in-depth mechanistic study demonstrated that FGFR1 interacts with FMDV VP3 and undergoes phosphorylation during FMDV entry. Furthermore, the FGFR1 inhibitor inhibited FMDV-induced activation of p21-activated kinase 1 (PAK1) on Thr212 and Thr423 sites. Consistent with these findings, the ectopic expression of FGFR1 resulted in a concomitant increase in phosphorylation level of PAK1 on Thr212 and Thr423 sites. Taken together, our findings represent the initial exploration of FGFR1's involvement in FMDV macropinocytic entry, providing novel insights with potential implications for the development of antiviral strategies.

Value based healthcare and Health Technology Assessment for emerging market countries: joint efforts to overcome barriers.

INTRODUCTION: This paper summarizes the results from a forum of healthcare experts, academia representatives, and public agency officials from emerging and established market countries on Value-Based Healthcare (VBHC) and Health Technology Assessment (HTA). Presentations from experts provided insights into current developments and challenges, followed by interactive roundtable discussions. Emerging markets have unique healthcare systems, patient populations, resource constraints and needs. AREAS COVERED: Each roundtable explored specific topics including the role of HTA and Real-world evidence (RWE) in healthcare decision-making, challenges in biosimilar value assessment and incorporating non-price criteria reflecting context-related specifications of emerging markets such as the multifaceted nature of value in healthcare decision-making, emphasizing stakeholder perspectives and system complexities. EXPERT OPINION: RWE emerged as important in understanding biosimilar value recognition and decision-making processes, with insights into its applications and challenges. Recommendations were provided for utilizing Multi-Criteria Decision Analysis (MCDA) in pharmaceutical procurement, particularly for off-patent medicines, underscoring the importance of comprehensive evaluation frameworks and adherence to value-based principles. Overall findings suggest avenues for collaboration between industry, academia, and public agencies to address implementation barriers and promote equitable, efficient, and high-quality healthcare systems in emerging markets through public-private partnerships, joint capacity building and training initiatives, and knowledge transfers.

Virtual Waiting Room: The New Narrative of Waiting in Oncology Care.

This conceptual study introduces the "virtual waiting room," an innovative, interactive, web-based platform designed to enhance the waiting experience in oncology by providing personalized, educational, and supportive content. Central to our study is the implementation of the circular entry model, which allows for non-linear navigation of health information, empowering patients to access content based on their immediate needs and interests. This approach respects the individual journeys of patients, acknowledging the diverse pathways through which they seek understanding and manage their health. The virtual waiting room is designed not only to support patients but also to facilitate stronger communication and shared understanding between patients, caregivers, and families. By providing a shared digital space, the platform enables caregivers and family members to access the same information and resources, thereby promoting transparency and collective knowledge. This shared access is crucial in managing the emotional complexities of oncology care, where effective communication can significantly impact treatment outcomes and patient well-being. Furthermore, the study explores how the circular entry model within the virtual waiting room can enhance patient autonomy and engagement by offering customized interactions based on user feedback and preferences. This personalized approach aims to reduce anxiety, improve health literacy, and prepare patients more effectively for clinical interactions. By transforming passive waiting into active engagement, the virtual waiting room turns waiting time into a meaningful, informative period that supports both the psychological and informational needs of patients and their support networks.

Impaired calcium influx underlies skewed T helper cell differentiation in children with IgE-mediated food allergies.

BACKGROUND: Reasons for Th2 skewing in IgE-mediated food allergies remains unclear. Clinical observations suggest impaired T cell activation may drive Th2 responses evidenced by increased atopic manifestations in liver transplant patients on tacrolimus (a calcineurin inhibitor). We aimed to assess differentiation potential, T cell activation and calcium influx of naïve CD4+ T cells in children with IgE-mediated food allergies. METHODS: Peripheral blood mononuclear cells from infants in the Starting Time for Egg Protein (STEP) Trial were analyzed by flow cytometry to assess Th1/Th2/Treg development. Naïve CD4+ T cells from children with and without food allergies were stimulated for 7 days to assess Th1/Th2/Treg transcriptional factors and cytokines. Store operated calcium entry (SOCE) was measured in children with and without food allergies. The effect of tacrolimus on CD4+ T cell differentiation was assessed by treating stimulated naïve CD4+ T cells from healthy volunteers with tacrolimus for 7 days. RESULTS: Egg allergic infants had impaired development of IFNγ+ Th1 cells and FoxP3+ transitional CD4+ T cells compared with non-allergic infants. This parallels reduced T-bet, IFNγ and FoxP3 expression in naïve CD4+ T cells from food allergic children after in vitro culture. SOCE of naïve CD4+ T cells was impaired in food allergic children. Naïve CD4+ T cells treated with tacrolimus had reduced IFNγ, T-bet, and FoxP3, but preserved IL-4 expression. CONCLUSIONS: In children with IgE-mediated food allergies, dysregulation of T helper cell development is associated with impaired SOCE, which underlies an intrinsic impairment in Th1 and Treg differentiation. Along with tacrolimus-induced Th2 skewing, this highlights an important role of SOCE/calcineurin pathway in T helper cell differentiation.

A comparative study of the versatility of various entry points for double-puncture TMJ arthrocentesis: A randomized controlled study.

Although various authors employed various entry points for the double-puncture technique (DPT) for arthrocentesis, the literature is devoid of any comparative studies. Therefore, the current prospective study aimed to evaluate the versatility of these different points. A total of 144 TMJs in 108 patients were included and randomly divided into two categories according to ID stage: category I (disc displacement without reduction with limitation), and category II (disc displacement without reduction without limitation). Patients in every category were randomly divided into 3 groups according to the site of entry point of the second needle: group 1 (20-10 point: 20 mm anterior to the tragus and 2 mm inferior to the cantho-tragus line), group 2 (20-1 point), and group 3 (7-2 point). For all patients, the first entry point was 10-2, and the upper joint cavity was irrigated with 150 ml of Ringer's solution without subsequent intra-articular injections. Group 3 had better results than group 2 and further than group 1 in categories I and II with regard to the number of second needle relocations, ease of the procedure, duration of the procedure, and nature of the outflow, as well as pain at rest and pain on function at 1, 3, and 6 post-operative months. For the maximum mouth opining, group 3 had better results than group 2 and further than group 1 only in category I. Therefore, techniques depending on the superior posterior entry points (such as 7-2 point) were recommended.

Tunneling Nanotubes: The Cables for Viral Spread and Beyond.

Multicellular organisms require cell-to-cell communication to maintain homeostasis and thrive. For cells to communicate, a network of filamentous, actin-rich tunneling nanotubes (TNTs) plays a pivotal role in facilitating efficient cell-to-cell communication by connecting the cytoplasm of adjacent or distant cells. Substantial documentation indicates that diverse cell types employ TNTs in a sophisticated and intricately organized fashion for both long and short-distance communication. Paradoxically, several pathogens, including viruses, exploit the structural integrity of TNTs to facilitate viral entry and rapid cell-to-cell spread. These pathogens utilize a "surfing" mechanism or intracellular transport along TNTs to bypass high-traffic cellular regions and evade immune surveillance and neutralization. Although TNTs are present across various cell types in healthy tissue, their magnitude is increased in the presence of viruses. This heightened induction significantly amplifies the role of TNTs in exacerbating disease manifestations, severity, and subsequent complications. Despite significant advancements in TNT research within the realm of infectious diseases, further studies are imperative to gain a precise understanding of TNTs' roles in diverse pathological conditions. Such investigations are essential for the development of novel therapeutic strategies aimed at leveraging TNT-associated mechanisms for clinical applications. In this chapter, we emphasize the significance of TNTs in the life cycle of viruses, showcasing the potential for a targeted approach to impede virus-host cell interactions during the initial stages of viral infections. This approach holds promise for intervention and prevention strategies.

Discovery of selective Orai channel blockers bearing an indazole or a pyrazole scaffold.

The calcium release activated calcium (CRAC) channel is highly expressed in T lymphocytes and plays a critical role in regulating T cell proliferation and functions including activation of the transcription factor nuclear factor of activated T cells (NFAT), cytokine production and cytotoxicity. The CRAC channel consists of the Orai pore subunit and STIM (stromal interacting molecule) endoplasmic reticulum calcium sensor. Loss of CRAC channel mediated calcium signaling has been identified as an underlying cause of severe combined immunodeficiency (SCID), leading to drastically weakened immunity against infections. Gain-of-function mutations in Orai and STIM have been associated with tubular aggregated myopathy (TAM), a skeletal muscle disease. While a number of small molecules have shown activity in inhibiting the CRAC signaling pathway, the usefulness of those tool compounds is limited by their off-target activity against TRPM4 and TRPM7 ion channels, high lipophilicity, and a lack of understanding of their mechanism of action. We report structure-activity relationship (SAR) studies that resulted in the characterization of compound 4k [1-(cyclopropylmethyl)-N-(3-fluoropyridin-4-yl)-1H-indazole-3-carboxamie] as a fast onset, reversible, and selective CRAC channel blocker. 4k fully blocked the CRAC current (IC50: 4.9 µM) and the nuclear translocation of NFAT at 30 and 10 µM, respectively, without affecting the electrophysiological function of TRPM4 and TRPM7 channels. Computational modeling appears to support its direction binding to Orai proteins that form the transmembrane CRACchannel.

Experimental dataset on aluminium wedge slamming: Measurements of acceleration, pressure, strain, and video data.

This paper presents data from three experimental campaigns investigating slamming loads on a three-dimensional non-prismatic aluminium wedge, complementing the original research article "Slamming loads and responses on a non-prismatic stiffened aluminium wedge: Part I. Experimental study [1]." The experiments were designed to investigate the effects of slamming loads on structural responses through a series of free-fall drop tests. These tests included wedges with stiffened and unstiffened bottom plates to examine the influence of flexural rigidity on hydroelastic slamming. The experimental setup utilized three accelerometers for vertical acceleration measurement, sixteen pressure sensors for slamming pressure capture, and twenty strain gauges for recording structural responses. Detailed information on wedge geometry, material properties, and test plans is provided. Symmetric impact tests were conducted at drop heights from 25 cm to 200 cm with two different wedge masses. Asymmetric impact tests were carried out at three drop heights with heel angles ranging from 5 to 25°. The dataset includes time histories of sensor records, the geometry of the wedge section, and video footage from various runs. This comprehensive data offers insights into the effects of water impact velocity, deadrise angle, wedge mass, and bending stiffness on hydrodynamic pressures and structural responses on V-shaped sections. The experiments provide a valuable benchmark for future slamming impact research, aiding in the refinement of experiments, validation of numerical methods, and enhancement of mathematical models.

DeepIRES: a hybrid deep learning model for accurate identification of internal ribosome entry sites in cellular and viral mRNAs.

The internal ribosome entry site (IRES) is a cis-regulatory element that can initiate translation in a cap-independent manner. It is often related to cellular processes and many diseases. Thus, identifying the IRES is important for understanding its mechanism and finding potential therapeutic strategies for relevant diseases since identifying IRES elements by experimental method is time-consuming and laborious. Many bioinformatics tools have been developed to predict IRES, but all these tools are based on structure similarity or machine learning algorithms. Here, we introduced a deep learning model named DeepIRES for precisely identifying IRES elements in messenger RNA (mRNA) sequences. DeepIRES is a hybrid model incorporating dilated 1D convolutional neural network blocks, bidirectional gated recurrent units, and self-attention module. Tenfold cross-validation results suggest that DeepIRES can capture deeper relationships between sequence features and prediction results than other baseline models. Further comparison on independent test sets illustrates that DeepIRES has superior and robust prediction capability than other existing methods. Moreover, DeepIRES achieves high accuracy in predicting experimental validated IRESs that are collected in recent studies. With the application of a deep learning interpretable analysis, we discover some potential consensus motifs that are related to IRES activities. In summary, DeepIRES is a reliable tool for IRES prediction and gives insights into the mechanism of IRES elements.

The ability of human TIM1 to bind phosphatidylethanolamine enhances viral uptake and efferocytosis compared to rhesus and mouse orthologs.

T-cell Immunoglobulin and Mucin (TIM)-family proteins facilitate the clearance of apoptotic cells, are involved in immune regulation, and promote infection of enveloped viruses. These processes are frequently studied in experimental animals such as mice or rhesus macaques, but functional differences among the TIM orthologs from these species have not been described. Previously, we reported that while all three human TIM proteins bind phosphatidylserine (PS), only human TIM1 (hTIM1) binds phosphatidylethanolamine (PE), and that this PE-binding ability contributes to both phagocytic clearance of apoptotic cells and virus infection. Here we show that rhesus macaque TIM1 (rhTIM1) and mouse TIM1 (mTIM1) bind PS but not PE and that their inability to bind PE makes them less efficient than hTIM1. We also show that alteration of only two residues of mTIM1 or rhTIM1 enables them to bind both PE and PS, and that these PE-binding variants are more efficient at phagocytosis and mediating viral entry. Further, we demonstrate that the mucin domain also contributes to the binding of the virions and apoptotic cells, although it does not directly bind phospholipid. Interestingly, contribution of the hTIM1 mucin domain is more pronounced in the presence of a PE-binding head domain. These results demonstrate that rhTIM1 and mTIM1 are inherently less functional than hTIM1, owing to their inability to bind PE and their less functional mucin domains. They also imply that mouse and macaque models underestimate the activity of hTIM1.

The Problem of Sequential Entry of Nurses as a Disincentive to Medical Safety and a Factor Increasing Overtime.

The purpose of this study was to visualize the nurses' approach to recording and to identify the causes that lead to overtime. The data used were those related to the performance and entry of nursing tasks (observation and care acts). Data from Hospital A, a provider of acute care with approximately 400 beds, was used. One month of work data were obtained from 12 nurses who were judged by the chief nurse to be excellent and efficient in their work. 12 nurses were divided into three groups: a high-level sequential entry rate group (>0.6), a medium-level sequential entry rate group (0.4 to <0.6), and a low-level sequential entry rate group (<0.4). The high-level sequential input rate group had data input every time they performed their work, so that the work implementation and input implementation were completed at 5:00 p.m. The medium-level sequential entry rate group tended to enter data about an hour late when they started work, which tended to result in overtime. The low-level sequential input rate group tended to input work in the afternoon, resulting in significant overtime. The data of approximately 400 nurses in a 900-bed University Hospital B, where Team Compass is implemented, were used to analyze the actual sequential input rate. 884 nurses in University Hospital B, of whom 397 had input data for 19 consecutive months. The sequential input rate in November 2020, one and a half years after the start of operation, was divided into five groups by 20%: 0-20%: 27 (7%), 20-40%: 30 (7%), 40-60%: 37 (9%), 60-80%: 69 (17%), and over 80%: 234 (59%). The number of employees who have been working overtime hours is also high. Although the importance of sequential entry to achieve results in reducing overtime hours continued to be strongly presented, there were 23% of nurses who indicated a sequential entry rate of less than 60%.

Linking Reimbursement to Patient Benefits for Advanced Therapy Medicinal Products and Other High-Cost Innovations: Policy Recommendations for Outcomes-Based Agreements in Europe.

OBJECTIVES: Health technology assessment (HTA) of advanced therapy medicinal products (ATMPs), such as high-cost and one-time cell and gene therapies, is particularly challenging. Outcomes-based agreements (OBAs) are a potential solution to mitigate the risks while providing access to patients but are not widely used across Europe. This study aimed to develop policy recommendations to support the acceptability and implementation of OBAs in Europe. METHODS: A policy sandbox approach was used to engage with stakeholders and explore how HTA organizations can support reimbursement decisions regarding OBAs for ATMPs. A panel of 38 experts from across the European region was convened in 2 workshops, representing payers, HTA organizations, patients, registries, and an industry trade body. RESULTS: Policy recommendations were developed to support the appropriate consideration of OBAs for reimbursing highly uncertain technologies, such as ATMPs. If a positive HTA recommendation cannot be made at the proposed price, then a simple price discount reflecting the uncertainty is preferred over complex solutions such as OBAs. If an OBA is pursued, it should be designed collaboratively with all stakeholders to understand data collection feasibility and minimize burden to patients and providers. Payers are encouraged to approach OBAs as a tool for informed decision making, including a readiness to make negative reimbursement decisions based on unfavorable evidence. CONCLUSIONS: The study presents a policy framework for using OBAs in reimbursement decisions. OBAs must be carefully designed, focusing on appropriateness and the burden of implementation. The relevant authorities should be committed to making decisions in light of the resulting evidence.

Clinical and pathological significance of Orai1 channel expression in human diabetic nephropathy.

Background: Targeted therapies for diabetic nephropathy (DN) are lacking, partly due to their irreversible nature. The role of Orai1, a store-operated Ca2+ channel, in DN remains debated, with conflicting evidence on its effect on proteinuria in animal models. We aimed to elucidate the functional relevance of Orai1 expression for clinicopathological parameters in patients with DN. Methods: In this study, we included 93 patients diagnosed with DN between 2009 and 2019. Immunohistochemical staining for Orai1 was performed on paraffin-embedded kidney sections. The significance of Orai1 expression in human DN was assessed by examining its correlation with DN's pathological and clinical parameters using Pearson's correlation coefficient and univariate logistic regression. Results: Orai1 was significantly overexpressed in DN patients compared to control. A strong correlation was observed between increased Orai1 expression and higher Renal Pathology Society DN classification, enhanced interstitial fibrosis and tubular atrophy scores. Positive correlations with serum creatinine levels and prognosis of chronic kidney disease (CKD) by glomerular filtration rate (GFR) and albuminuria category were noted but the estimated GFR was inversely related to Orai1 expression. Orai1's association with advanced CKD stages persisted even after adjusting for confounding variables in multivariate logistic regression analysis. Conclusion: Orai1 expression is closely associated with histological and clinical severities of DN, suggesting its potential as a predictive biomarker for disease progression and prognosis. These findings provide new perspectives on therapeutic interventions targeting Orai1 in DN.

Relationship between oligoarginine-induced membrane damage of single Escherichia coli cells and entry of the peptide into the cytoplasm.

Cell-penetrating peptides (CPPs) can enter the cytosol of eukaryotic cells without killing them whereas some CPPs exhibit antimicrobial activity against bacterial cells. Here, to elucidate the mode of interaction of the CPP nona-arginine (R9) with bacterial cells, we investigated the interactions of lissamine rhodamine B red-labeled peptide (Rh-R9) with single Escherichia coli cells encapsulating calcein using confocal laser scanning microscopy. After Rh-R9 induced the leakage of a large amount of calcein, the fluorescence intensity of the cytosol due to Rh-R9 greatly increased, indicating that Rh-R9 induces cell membrane damage, thus allowing entry of a significant amount of Rh-R9 into the cytosol. To determine if the lipid bilayer region of the membrane is the main target of Rh-R9, we then investigated the interaction of Rh-R9 with single giant unilamellar vesicles (GUVs) comprising an E. coli polar lipid extract containing small GUVs and AlexaFluor 647 hydrazide (AF647) in the lumen. Rh-R9 entered the GUV lumen without inducing AF647 leakage, but leakage eventually did occur, indicating that GUV membrane damage was induced after the entry of Rh-R9 into the GUV lumen. The Rh-R9 peptide concentration dependence of the fraction of entry of Rh-R9 after a specific interaction time was similar to that of the fraction of leaking GUVs. These results indicate that Rh-R9 can damage the lipid bilayer region of a cell membrane, which may be related to its antimicrobial activity.

N,N,N',N'-Tetrakis(2-pyridylmethyl)ethylenediamine induces endothelium-dependent hyperpolarization-mediated vasorelaxation via store-operated calcium entry mechanism in healthy and intestinal inflammatory mice.

Although the store-operated Ca2+ entry (SOCE) plays a critical role in maintaining Ca2+ homeostasis in vascular endothelial cells (VECs), its role in regulating endothelium-dependent hyperpolarization (EDH)-mediated vasorelaxation is largely unknown. Inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) are the most common gastrointestinal disorders with no effective cures. The present study applied N,N,N',N'-tetrakis (2-pyridylmethyl)ethylenediamine (TPEN) as a Ca2+ chelator in the endoplasmic reticulum (ER) to study the SOCE/EDH-mediated vasorelaxation of micro-arteries and their involvements in the pathogenesis of IBD and IBS. Human submucosal arterioles and the second-order branch of 6-8 weeks male C57BL/6 mouse mesenteric arterioles were used, and TPEN-induced vasorelaxation was recorded by Danish DMT520A microvascular measuring system. The mice were fed water with 2.5 % dextran sulfate sodium for 7 days to induce mouse model of ulcerative colitis, and water avoidance stress was used to induce mouse model of IBS. The statistical significance of differences in the means of experimental groups was determined using a t-test for two groups or one-way ANOVA for more than two groups. TPEN concentration-dependently induced vasorelaxation of human colonic submucosal arterioles and the second-order branch of murine mesenteric arteries in endothelium-dependent manner. TPEN-induced vasorelaxation was much greater in the arteries pre-constricted by noradrenaline than those by high K+. While TPEN-induced vasorelaxation was unaffected by inhibitors of NO and PGI2, it was significantly inhibited by the selective inhibitors of IKCa and SKCa channels but was potentiated by their activator. Moreover, TPEN-induced vasorelaxation was attenuated by selective inhibitors of NCX, NKA, SOCE, STIM translocation and Orai transportation. Finally, TPEN-induced vasorelaxation via SOCE/EDH was impaired in colitic mice but remained intact in IBS mice. Interestingly, TPEN could rescue vagus neurotransmitter ACh-induced vasorelaxation that was impaired in IBS mice. Therefore, since TPEN-induced SOCE/EDH-mediated vasorelaxation of mesenteric arteries is well-preserved to be able to rescue ACh-induced vasorelaxation impaired in IBS, TPEN has therapeutic potentials for IBS.

SARS-CoV-2 spike fusion peptide trans interaction with phosphatidylserine lipid triggers membrane fusion for viral entry.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike is the fusion machine for host cell entry. Still, the mechanism by which spike protein interacts with the target lipid membrane to facilitate membrane fusion during entry is not fully understood. Here, using steady-state membrane fusion and single-molecule fluorescence resonance energy transfer imaging of spike trimers on the surface of SARS-CoV-2 pseudovirion, we directly show that spike protein interacts with phosphatidylserine (PS) lipid in the target membrane for mediating fusion. We observed that the fusion peptide of the spike S2 domain interacts with the PS lipid of the target membrane. Low pH and Ca2+ trigger the spike conformational change and bring fusion peptide in close proximity to the PS lipid of the membrane. The binding of the spike with PS lipid of its viral membrane (cis interaction) impedes the fusion activation. PS on the target membrane promotes spike binding via trans interaction, prevents the cis interaction, and accelerates fusion. Sequestering or absence of PS lipid abrogates the spike-mediated fusion process and restricts SARS-CoV-2 infectivity. We found that PS-dependent interaction for fusion is conserved across all the SARS-CoV-2 spike variants of concern (D614G, Alpha, Beta, Delta, and Omicron). Our study suggests that PS lipid is indispensable for SARS-CoV-2 spike-mediated virus and target membrane fusion for entry, and restricting PS interaction with spike inhibits the SARS-CoV-2 spike-mediated entry. Therefore, PS is an important cofactor and acts as a molecular beacon in the target membrane for SARS-CoV-2 entry. IMPORTANCE: The role of lipids in the host cell target membrane for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) entry is not clear. We do not know whether SARS-CoV-2 spike protein has any specificity in terms of lipid for membrane fusion reaction. Here, using in vitro reconstitution of membrane fusion assay and single-molecule fluorescence resonance energy transfer imaging of SARS-CoV-2 spike trimers on the surface of the virion, we have demonstrated that phosphatidylserine (PS) lipid plays a key role in SARS-CoV-2 spike-mediated membrane fusion reaction for entry. Membrane-externalized PS lipid strongly promotes spike-mediated membrane fusion and COVID-19 infection. Blocking externalized PS lipid with PS-binding protein or in the absence of PS, SARS-CoV-2 spike-mediated fusion is strongly inhibited. Therefore, PS is an important target for restricting viral entry and intervening spike, and PS interaction presents new targets for COVID-19 interventions.

Comprehensive morphometric analysis of the rhomboid fossa: implications for safe entry zones in brainstem surgery.

BACKGROUND: The rhomboid fossa (RF) is a crucial anatomical region in brainstem surgery, as it contains essential structures like the reticular formation and cranial nerve nuclei. This study aims to provide a detailed understanding of the RF's complex microsurgical anatomy, which is vital for the safe execution of neurosurgical procedures. METHODS: Morphometric analysis was conducted on 45 adult human brainstems preserved in 10% formalin. Thirteen linear measurements were performed under 20x magnification, using a millimeter graph to identify key anatomical landmarks. RESULTS: The study provided precise measurements of the rhomboid fossa, with a length of 34.65 mm and a width of 22.61 mm. The facial colliculus (FC) measured 4.26 mm in length on the left and 4.45 mm on the right, with corresponding widths of 3.77 mm and 3.50 mm. The distance between the sulcus limitans incisures was 9.52 mm, while the distance from the upper border of the medullary striae to obex was 11.53 mm. The proximity of the FC to the median sulcus was measured at 0.86 mm on the right and 0.96 mm on the left. Additionally, two safe entry zones-the suprafacial and infrafacial triangles-were identified, offering pathways to reach dorsal pons lesions through the RF. CONCLUSION: This comprehensive morphometric analysis of the RF enhances the understanding of its intricate anatomy. By describing safe entry zones, the suprafacial and infrafacial triangles, and providing precise measurements of key anatomical features, this research serves as a valuable resource for neurosurgeons in planning and executing brainstem surgeries.

Revealing Different Pathways for Influenza A Virus To Reach Microtubules after Endocytosis by Quantum Dot-Based Single-Virus Tracking.

Actin- and microtubule (MT)-based transport systems are essential for intracellular transport. During influenza A virus (IAV) infection, MTs provide long tracks for virus trafficking toward the nucleus. However, the role of the actin cytoskeleton in IAV entry and especially the transit process is still ambiguous. Here, by using quantum dot-based single-virus tracking, it was revealed that the actin cytoskeleton was crucial for the virus entry via clathrin-mediated endocytosis (CME). After entry via CME, the virus reached MTs through three different pathways: the virus (1) was driven by myosin VI to move along actin filaments to reach MTs (AF); (2) was propelled by actin tails assembled by an Arp2/3-dependent mechanism to reach MTs (AT); and (3) directly reached MTs without experiencing actin-related movement (NA). Therefore, the NA pathway was the main one and the fastest for the virus to reach MTs. The AT pathway was activated only when plenty of viruses entered the cell. The viruses transported by the AF and AT pathways shared similar moving velocities, durations, and displacements. This study comprehensively visualized the role of the actin cytoskeleton in IAV entry and transport, revealing different pathways for IAV to reach MTs after entry. The results are of great significance for globally understanding IAV infection and the cellular endocytic transport pathway.