HSP90 Inhibitors Modulate SARS-CoV-2 Spike Protein Subunit 1-Induced Human Pulmonary Microvascular Endothelial Activation and Barrier Dysfunction

Litopenaeus vannamei heat shock protein 90 (LvHSP90) interacts with white spot syndrome virus protein, WSSV322, to modulate hemocyte apoptosis during viral infection

As cellular chaperones, heat shock protein can facilitate viral infection in different steps of infection process. Previously, we have shown that the suppression of Litopenaeus vannamei (Lv)HSP90 not only results in a decline of white spot syndrome virus (WSSV) infection but also induces apoptosis in shrimp hemocyte cells. However, the mechanism underlying how LvHSP90 involved in WSSV infection remains largely unknown. In this study, a yeast two-hybrid assay and co-immunoprecipitation revealed that LvHSP90 interacts with the viral protein WSSV322 which function as an anti-apoptosis protein. Recombinant protein (r) LvHSP90 and rWSSV322 inhibited cycloheximide-induced hemocyte cell apoptosis in vitro. Co-silencing of LvHSP90 and WSSV322 in WSSV-infected shrimp led to a decrease in expression level of viral replication marker genes (VP28, ie-1) and WSSV copy number, while caspase 3/7 activity was noticeably induced. The number of apoptotic cells, confirmed by Hoechst 33342 staining assay and annexin V/PI staining, was significantly higher in LvHSP90 and WSSV322 co-silenced-shrimp than the control groups. Moreover, the co-silencing of LvHSP90 and WSSV322 triggered apoptosis by the mitochondrial pathway, resulting in the upregulation of pro-apoptotic protein expression (bax) and the downregulation of anti-apoptotic protein expression (bcl, Akt). This process also involved the release of cytochrome c (CytC) from the mitochondria and a decrease in mitochondrial membrane potential (MMP). These findings suggest that LvHSP90 interacts with WSSV322 to facilitate viral replication by inhibiting host apoptosis during WSSV infection.

Influenza, SARS-CoV-2, and Their Impact on Chronic Lung Diseases and Fibrosis: Exploring Therapeutic Options

Respiratory tract infections represent a significant global public health concern, disproportionately affecting vulnerable populations such as children, the elderly, and immunocompromised individuals. RNA viruses, particularly influenza viruses and coronaviruses, significantly contribute to respiratory illnesses, especially in immunosuppressed and elderly individuals. Influenza A viruses (IAVs) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continue to pose global health threats due to their capacity to cause annual epidemics, with profound implications for public health. In addition, the increase in global life expectancy is influencing the dynamics and outcomes of respiratory viral infections. Understanding the molecular mechanisms by which IAVs and SARS-CoV-2 contribute to lung disease progression is therefore crucial. The aim of this review was to comprehensively explore the impact of IAVs and SARS-CoV-2 on chronic lung diseases, with a specific focus on pulmonary fibrosis in the elderly. It also outlines potential preventive and therapeutic strategies and suggests directions for future research.

Protective role of the HSP90 inhibitor, STA-9090, in lungs of SARS-CoV-2-infected Syrian golden hamsters

INTRODUCTION

The emergence of new SARS-CoV-2 variants, capable of escaping the humoral immunity acquired by the available vaccines, together with waning immunity and vaccine hesitancy, challenges the efficacy of the vaccination strategy in fighting COVID-19. Improved therapeutic strategies are urgently needed to better intervene particularly in severe cases of the disease. They should aim at controlling the hyperinflammatory state generated on infection, reducing lung tissue pathology and inhibiting viral replication. Previous research has pointed to a possible role for the chaperone HSP90 in SARS-CoV-2 replication and COVID-19 pathogenesis. Pharmacological intervention through HSP90 inhibitors was shown to be beneficial in the treatment of inflammatory diseases, infections and reducing replication of diverse viruses.

METHODS

In this study, we investigated the effects of the potent HSP90 inhibitor Ganetespib (STA-9090) in vitro on alveolar epithelial cells and alveolar macrophages to characterise its effects on cell activation and viral replication. Additionally, the Syrian hamster animal model was used to evaluate its efficacy in controlling systemic inflammation and viral burden after infection.

RESULTS

In vitro, STA-9090 reduced viral replication on alveolar epithelial cells in a dose-dependent manner and lowered significantly the expression of proinflammatory genes, in both alveolar epithelial cells and alveolar macrophages. In vivo, although no reduction in viral load was observed, administration of STA-9090 led to an overall improvement of the clinical condition of infected animals, with reduced oedema formation and lung tissue pathology.

CONCLUSION

Altogether, we show that HSP90 inhibition could serve as a potential treatment option for moderate and severe cases of COVID-19.

Regulation of Epithelial and Endothelial Barriers by Molecular Chaperones

The integrity and permeability of epithelial and endothelial barriers depend on the formation of tight junctions, adherens junctions, and a junction-associated cytoskeleton. The establishment of this junction-cytoskeletal module relies on the correct folding and oligomerization of its protein components. Molecular chaperones are known regulators of protein folding and complex formation in different cellular compartments. Mammalian cells possess an elaborate chaperone network consisting of several hundred chaperones and co-chaperones. Only a small part of this network has been linked, however, to the regulation of intercellular adhesions, and the systematic analysis of chaperone functions at epithelial and endothelial barriers is lacking. This review describes the functions and mechanisms of the chaperone-assisted regulation of intercellular junctions. The major focus of this review is on heat shock protein chaperones, their co-chaperones, and chaperonins since these molecules are the focus of the majority of the articles published on the chaperone-mediated control of tissue barriers. This review discusses the roles of chaperones in the regulation of the steady-state integrity of epithelial and vascular barriers as well as the disruption of these barriers by pathogenic factors and extracellular stressors. Since cytoskeletal coupling is essential for junctional integrity and remodeling, chaperone-assisted assembly of the actomyosin cytoskeleton is also discussed.

Syphilis and the host: multi-omic analysis of host cellular responses to Treponema pallidum provides novel insight into syphilis pathogenesis

Introduction

Syphilis is a chronic, multi-stage infection caused by the extracellular bacterium Treponema pallidum ssp. pallidum. Treponema pallidum widely disseminates through the vasculature, crosses endothelial, blood-brain and placental barriers, and establishes systemic infection. Although the capacity of T. pallidum to traverse the endothelium is well-described, the response of endothelial cells to T. pallidum exposure, and the contribution of this response to treponemal traversal, is poorly understood.

Methods

To address this knowledge gap, we used quantitative proteomics and cytokine profiling to characterize endothelial responses to T. pallidum.

Results

Proteomic analyses detected altered host pathways controlling extracellular matrix organization, necroptosis and cell death, and innate immune signaling. Cytokine analyses of endothelial cells exposed to T. pallidum revealed increased secretion of interleukin (IL)-6, IL-8, and vascular endothelial growth factor (VEGF), and decreased secretion of monocyte chemoattractant protein-1 (MCP-1).

Discussion

This study provides insight into the molecular basis of syphilis disease symptoms and the enhanced susceptibility of individuals infected with syphilis to HIV co-infection. These investigations also enhance understanding of the host response to T. pallidum exposure and the pathogenic strategies used by T. pallidum to disseminate and persist within the host. Furthermore, our findings highlight the critical need for inclusion of appropriate controls when conducting T. pallidum-host cell interactions using in vitro- and in vivo-grown T. pallidum.

An acute respiratory distress syndrome drug development collaboration stimulated by the Virginia Drug Discovery Consortium

The genesis of most older medicinal agents has generally been empirical. During the past one and a half centuries, at least in the Western countries, discovering and developing drugs has been primarily the domain of pharmaceutical companies largely built upon concepts emerging from organic chemistry. Public sector funding for the discovery of new therapeutics has more recently stimulated local, national, and international groups to band together and focus on new human disease targets and novel treatment approaches. This Perspective describes one contemporary example of a newly formed collaboration that was simulated by a regional drug discovery consortium. University of Virginia, Old Dominion University, and a university spinout company, KeViRx, Inc., partnered under a NIH Small Business Innovation Research grant, to produce potential therapeutics for acute respiratory distress syndrome resulting from the ongoing COVID-19 pandemic.

The SARS-CoV-2 spike S1 protein induces global proteomic changes in ATII-like rat L2 cells that are attenuated by hyaluronan

The COVID-19 pandemic continues to impose a major impact on global health and economy since its identification in early 2020, causing significant morbidity and mortality worldwide. Caused by the SARS-CoV-2 virus, along with a growing number of variants, COVID-19 has led to 651,918,402 confirmed cases and 6,656,601 deaths worldwide (as of December 27, 2022; https://covid19.who.int/). Despite advances in our understanding of COVID-19 pathogenesis, the precise mechanism by which SARS-CoV2 causes epithelial injury is incompletely understood. In this current study, robust application of global-discovery proteomics identified highly significant induced changes by the Spike S1 protein of SARS-CoV-2 in the proteome of alveolar type II (ATII)-like rat L2 cells that lack ACE2 receptors. Systems biology analysis revealed that the S1-induced proteomics changes were associated with three significant network hubs: E2F1, CREB1/RelA, and ROCK2/RhoA. We also found that pretreatment of L2 cells with high molecular weight hyaluronan (HMW-HA) greatly attenuated the S1 effects on the proteome. Western blotting analysis and cell cycle measurements confirmed the S1 upregulation of E2F1 and ROCK2/RhoA in L2 cells and the protective effects of HMW-HA. Taken as a whole, our studies revealed profound and novel biological changes that contribute to our current understanding of both S1 and hyaluronan biology. These data show that the S1 protein may contribute to epithelial injury induced by SARS-CoV-2. In addition, our work supports the potential benefit of HMW-HA in ameliorating SARS CoV-2-induced cell injury.

COVID-19 Vaccination and Alcohol Consumption: Justification of Risks

Since the beginning of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, pharmaceutical companies and research institutions have been actively working to develop vaccines, and the mass roll-out of vaccinations against COVID-19 began in January 2021. At the same time, during lockdowns, the consumption of alcoholic beverages increased. During the peak of vaccination, consumption remained at high levels around the world, despite the gradual relaxation of quarantine restrictions. Two of the popular queries on search engines were whether it is safe to drink alcohol after vaccination and whether this will affect the effectiveness of vaccines. Over the past two years, many studies have been published suggesting that excessive drinking not only worsens the course of an acute respiratory distress syndrome caused by the SARS-CoV-2 virus but can also exacerbate post-COVID-19 syndrome. Despite all sorts of online speculation, there is no specific scientific data on alcohol-induced complications after vaccination in the literature. Most of the published vaccine clinical trials do not include groups of patients with a history of alcohol-use disorders. This review analyzed the well-known and new mechanisms of action of COVID-19 vaccines on the immune system and the effects of alcohol and its metabolites on these mechanisms.

Label-Free Analysis of Binding and Inhibition of SARS-Cov-19 Spike Proteins to ACE2 Receptor with ACE2-Derived Peptides by Surface Plasmon Resonance

SARS-CoV-2 has been shown to enter and infect human cells via interactions between spike protein (S glycoprotein) and angiotensin-converting enzyme 2 (ACE2). As such, it may be possible to suppress the infection of the virus via the blocking of this binding interaction through the use of specific peptides that can mimic the human ACE 2 peptidase domain (PD) α 1-helix. Herein, we report the use of competitive assays along with surface plasmon resonance (SPR) to investigate the effect of peptide sequence and length on spike protein inhibition. The characterization of these binding interactions helps us understand the mechanisms behind peptide-based viral blockage and develop SPR methodologies to quickly screen disease inhibitors. This work not only helps further our understanding of the important biological interactions involved in viral inhibition but will also aid in future studies that focus on the development of therapeutics and drug options. Two peptides of different sequence lengths, [30-42] and [22-44], based on the α 1-helix of ACE2 PD were selected for this fundamental investigation. In addition to characterizing their inhibitory behavior, we also identified the critical amino acid residues of the RBD/ACE2-derived peptides by combining experimental results and molecular docking modeling. While both investigated peptides were found to effectively block the RBD residues known to bind to ACE2 PD, our investigation showed that the shorter peptide was able to reach a maximal inhibition at lower concentrations. These inhibition results matched with molecular docking models and indicated that peptide length and composition are key in the development of an effective peptide for inhibiting biophysical interactions. The work presented here emphasizes the importance of inhibition screening and modeling, as longer peptides are not always more effective.

Targeting heat shock proteins 90 and 70: A promising remedy for both autoimmune bullous diseases and COVID-19

Heat shock proteins (Hsps), including Hsp90 and Hsp70, are intra- and extracellular molecules implicated in cellular homeostasis and immune processes and are induced by cell stress such as inflammation and infection. Autoimmune bullous disorders (AIBDs) and COVID-19 represent potentially life-threatening inflammatory and infectious diseases, respectively. A significant portion of AIBDs remain refractory to currently available immunosuppressive therapies, which may represent a risk factor for COVID-19, and suffer from treatment side-effects. Despite advances in vaccination, there is still a need to develop new therapeutic approaches targeting SARS-CoV-2, especially considering vaccine hesitancy, logistical distribution challenges, and breakthrough infections. In this mini review, we briefly summarize the role of targeting Hsp90/70 as a promising double-edged sword in the therapy of AIBDs and COVID-19.

SARS-CoV-2 Spike triggers barrier dysfunction and vascular leak via integrins and TGF-β signaling

Severe COVID-19 is associated with epithelial and endothelial barrier dysfunction within the lung as well as in distal organs. While it is appreciated that an exaggerated inflammatory response is associated with barrier dysfunction, the triggers of vascular leak are unclear. Here, we report that cell-intrinsic interactions between the Spike (S) glycoprotein of SARS-CoV-2 and epithelial/endothelial cells are sufficient to induce barrier dysfunction in vitro and vascular leak in vivo, independently of viral replication and the ACE2 receptor. We identify an S-triggered transcriptional response associated with extracellular matrix reorganization and TGF-β signaling. Using genetic knockouts and specific inhibitors, we demonstrate that glycosaminoglycans, integrins, and the TGF-β signaling axis are required for S-mediated barrier dysfunction. Notably, we show that SARS-CoV-2 infection caused leak in vivo, which was reduced by inhibiting integrins. Our findings offer mechanistic insight into SARS-CoV-2-triggered vascular leak, providing a starting point for development of therapies targeting COVID-19.

The role of angiotensin I converting enzyme insertion/deletion polymorphism in the severity and outcomes of COVID-19 patients

The pandemic of coronavirus disease in 2019 has led to a global crisis. COVID-19 shows distinct clinical manifestations of the severity of symptoms. Numerous patients with no associated risk factors demonstrate acute respiratory distress syndrome (ARDS). The role of genetic factors in determining the severity and outcome of the disease remains unresolved. The purpose of this study was to see if a correlation exists between Angiotensin I Converting Enzyme (ACE) insertion/deletion (I/D) polymorphism and the severity of COVID-19 patients’ symptoms. 120 COVID-19 patients admitted to Masih Daneshvari Hospital in Tehran with their consent to participate entered the study. Based on the World Health Organization classification, patients were divided into moderate and severe groups, which were primarily affected by O2 saturation levels. The effects of the patients’ ACE insertion/deletion polymorphism, background disease, Angiotensin receptor blocker (ARB) drug consumption, and demographic parameters on the severity risk were calculated statistically. The ACE D allele was associated with an increased risk of disease severity (OR = 6.766, p = 0.012), but had no effect on mortality.

Optimizing antidotal treatment with the oral HSP90 inhibitor TAS-116 against hydrochloric acid-induced pulmonary fibrosis in mice

Exposure to high concentrations of hydrochloric acid (HCl) can lead to severe acute and chronic lung injury. In the aftermath of accidental spills, victims may be treated for the acute symptoms, but the chronic injury is often overlooked. We have developed a mouse model of acute and chronic lung injury, in which the peak of acute lung injury occurs on the day 4 after HCl exposure. We have also demonstrated that HSP90 inhibitors are effective antidotes when administered starting 24 h after HCl. In this study we examined the hypothesis that the novel oral HSP90 inhibitor TAS-116 can effectively ameliorate HCl-induced lung injury even when treatment starts at the peak of the acute injury, as late as 96 h after HCl. C57BI/6J mice were intratracheally instilled with 0.1N HCl. After 24 or 96 h, TAS-116 treatment began (3.5, 7 or 14 mg/kg, 5 times per week, p. o.) for either 2,3 or 4 or weeks. TAS-116 moderated the HCl-induced alveolar inflammation, as reflected in the reduction of white blood cells and total protein content in bronchoalveolar lavage fluid (BALF), overexpression of NLRP3 inflammasome, and inhibited the activation of pro-fibrotic pathways. Furthermore, TAS-116 normalized lung mechanics and decreased the deposition of extracellular matrix proteins in the lungs of mice exposed to HCl. Delayed and shortened treatment with TAS-116, successfully blocked the adverse chronic effects associated with acute exposure to HCl.

Calcium dobesilate reduces SARS-CoV-2 entry into endothelial cells by inhibiting virus binding to heparan sulfate

Recent reports demonstrate that SARS-CoV-2 utilizes cell surface heparan sulfate as an attachment factor to facilitate the initial interaction with host cells. Heparan sulfate interacts with the receptor binding domain of SARS-CoV-2 spike glycoprotein, and blocking this interaction can decrease cell infection. We and others reported recently that the family of compounds of 2,5-dihydroxyphenylic acid interferes with the binding of the positively charged groove in growth factor molecules to negatively charged cell surface heparan sulfate. We hypothesized that Calcium Dobesilate (CaD)-calcium salt of 2,5-dihydroxyphenylic acid-may also interfere with the binding of SARS-CoV-2 spike protein to heparan sulfate. Using lentiviral SARS-CoV-2 spike protein pseudotyped particles we show that CaD could significantly reduce pseudovirus uptake into endothelial cells. On the contrary, CaD did not affect cell infection with VSVG-expressing lentivirus. CaD could also prevent retention of SARS-CoV-2 spike protein in ex vivo perfused mouse kidney. Using microfluidic culture of endothelial cells under flow, we show that CaD prevents spike protein interaction with heparan sulfate glycocalyx. Since CaD has no adverse side effects and is approved in humans for other medical indications, our findings can rapidly translate into clinical studies.

Host cell stress response as a predictor of COVID-19 infectivity and disease progression

The coronavirus disease (COVID-19) caused by a coronavirus identified in December 2019 has caused a global pandemic. COVID-19 was declared a pandemic in March 2020 and has led to more than 6.3 million deaths. The pandemic has disrupted world travel, economies, and lifestyles worldwide. Although vaccination has been an effective tool to reduce the severity and spread of the disease there is a need for more concerted approaches to fighting the disease. COVID-19 is characterised as a severe acute respiratory syndrome . The severity of the disease is associated with a battery of comorbidities such as cardiovascular diseases, cancer, chronic lung disease, and renal disease. These underlying diseases are associated with general cellular stress. Thus, COVID-19 exacerbates outcomes of the underlying conditions. Consequently, coronavirus infection and the various underlying conditions converge to present a combined strain on the cellular response. While the host response to the stress is primarily intended to be of benefit, the outcomes are occasionally unpredictable because the cellular stress response is a function of complex factors. This review discusses the role of the host stress response as a convergent point for COVID-19 and several non-communicable diseases. We further discuss the merits of targeting the host stress response to manage the clinical outcomes of COVID-19.

Endothelial cell-derived extracellular vesicles impair the angiogenic response of coronary artery endothelial cells

Cardiovascular disease (CVD) is the most prominent cause of death of adults in the United States with coronary artery disease being the most common type of CVD. Following a myocardial event, the coronary endothelium plays an important role in the recovery of the ischemic myocardium. Specifically, endothelial cells (EC) must be able to elicit a robust angiogenic response necessary for tissue revascularization and repair. However, local or distant cues may prevent effective revascularization. Extracellular vesicles (EV) are produced by all cells and endothelium is a rich source of EVs that have access to the main circulation thereby potentially impacting local and distant tissue function. Systemic inflammation associated with conditions such as obesity as well as the acute inflammatory response elicited by a cardiac event can significantly increase the EV release by endothelium and alter their miRNA, protein or lipid cargo. Our laboratory has previously shown that EVs released by adipose tissue endothelial cells exposed to chronic inflammation have angiostatic effects on naïve adipose tissue EC in vitro. Whether the observed effect is specific to EVs from adipose tissue endothelium or is a more general feature of the endothelial EVs exposed to pro-inflammatory cues is currently unclear. The objective of this study was to investigate the angiostatic effects of EVs produced by EC from the coronary artery and adipose microvasculature exposed to pro-inflammatory cytokines (PIC) on naïve coronary artery EC. We have found that EVs from both EC sources have angiostatic effects on the coronary endothelium. EVs produced by cells in a pro-inflammatory environment reduced proliferation and barrier function of EC without impacting cellular senescence. Some of these functional effects could be attributed to the miRNA cargo of EVs. Several miRNAs such as miR-451, let-7, or miR-23a impact on multiple pathways responsible for proliferation, cellular permeability and angiogenesis. Collectively, our data suggests that EVs may compete with pro-angiogenic cues in the ischemic myocardium therefore slowing down the repair response. Acute treatments with inhibitors that prevent endogenous EV release immediately after an ischemic event may contribute to better efficacy of therapeutic approaches using functionalized exogenous EVs or other pro-angiogenic approaches.

The Role of Nuclear Factor Kappa B (NF-κB) in Development and Treatment of COVID-19: Review

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes Coronavirus Disease 19 (COVID-19), a disease that has affected more than 500 million people worldwide since the end of 2019. Due to its high complications and death rates, there is still a need to find the best therapy for SARS-CoV-2 infection. The dysregulation of the inflammatory response in COVID-19 plays a very important role in disease progression. It has been observed that abnormal activity of Nuclear Factor kappa B (NF-κB) is directly associated with, inter alia, increased synthesis of proinflammatory factors. Therefore, this review paper focuses on the functions of NF-κB in the development of SARS-CoV-2 infection and potential application of NF-κB inhibitors in COVID-19 immunotherapy. A comprehensive literature search was performed using the MEDLINE/PubMed database. In the current review, it is highlighted that NF-κB plays important functions in the modulation of an adaptive inflammatory response, including inducing the expression of proinflammatory genes. Increased activation of NF-κB in SARS-CoV-2 infection was observed. The association between NF-κB activation and the expression of SARS-CoV-2 structural and non-structural proteins were also reported. It was observed that modulation of NF-κB using, e.g., traditional Chinese medicine or glucocorticosteroids resulted in decreased synthesis of proinflammatory factors caused by SARS-CoV-2 infection. This review summarizes the role of NF-κB in COVID-19 and describes its potential immunotherapeutic target in treatment of SARS-CoV-2 infection. However, indisputably more studies involving patients with a severe course of COVID-19 are sorely needed.