SARS-CoV-2 spike S1 mediated lung tumor regression in a mouse model

Lung cancer is the leading cause of cancer related deaths worldwide, with a relatively low 5-year survival rate. Although there are some therapies against lung cancer, new effective treatment options are urgently required. Recently during the COVID-19 pandemic, we have seen that SARSCoV-2 binds to its receptor angiotensin-converting enzyme 2 (ACE2) via spike S1 to enter the cells. This study underlines the importance of SARS-CoV-2 spike S1 in inducing death in human lung cancer cells. Interestingly, we have seen that recombinant spike S1 treatment at very low doses led to death of human A549 lung cancer cells. On the other hand, boiled recombinant SARS-CoV-2 spike S1 remained unable to induce death, suggesting that the induction of cell death in A549 cells was due to native SARS-CoV-2 spike S1 protein. SARS-CoV-2 spike S1-induced A549 cell death was also inhibited by neutralizing antibodies against spike S1 and ACE2. Moreover, our newly designed wild type ACE2-interacting domain of SARS-CoV-2 (wtAIDS), but not mAIDS, peptide also attenuated SARS-CoV-2 spike S1-induced cell death, suggesting that SARS-CoV-2 spike S1- induced death in lung cancer cells depends on its interaction with ACE2 receptor. Similarly, recombinant spike S1 treatment also led to death of H1299 and H358 human lung cancer cells. Finally, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) intoxication led to the formation tumors in lungs of A/J mice and alternate day intranasal treatment with low dose of recombinant SARS-CoV-2 spike S1 from 22-weeks of NNK insult (late stage) led to induced apoptosis and tumor regression in the lungs. These studies indicate that recombinant SARS-CoV-2 Spike S1 protein may have implications in the treatment of lung cancer.

Application of Convolutional Neural Network techniques to the classification of lung illnesses

The heterotypic perspective of cancer depicts solid tumors as ecosystems composed of aberrant epithelium tumor cells and a multitude of cell types together referred to as stromal cells. Macrophages, which are innate immune cells, are overrepresented in certain environments. Tumor-associated macrophages (TAMs) are macrophages found in the tumor microenvironment;they are derived from the blood's monocytes and are essential for tumor progression. TAMs acquiring tumorigenic qualities is dependent on a complicated interaction between TAMs and tumor cells. Using co-culture studies, we showed that tumor-derived secretory signals promote Tams' tumor-promoting characteristics, shaping up Tams' features in ways that are advantageous to the tumor. When model human monocytes (THP-1) were co-cultured with A549 cells, the A549 cells exhibited increased proliferation, migration, and invasiveness due to the secretion of tumor-promoting cytokines from the THP-1 cells. We showed that EDA-containing Fibronectin secreted by A549 cells reliably mediates the pro-inflammatory response of THP-1 monocytes in a paracrine manner. Ablation of such responses by the treatment of THP-1 cells with TLR-4 blocking antibody implicated Fibronectin-TLR4 axis in tumor-associated inflammation and suggests a paradigm wherein lung carcinoma cell derived EDA-containing Fibronectin drives a pro-inflammatory and pro-metastatic tumor microenvironment. Interestingly, autocrine proliferation, migration, and invasion were all boosted by EDA-containing Fibronectin secreted by A549 cells. Lastly, we demonstrated that the EDA in Fibronectin activates the epithelial-mesenchymal transition pathway in A549 cells, hence granting these cells the ability to metastasize. © 2023 IEEE.

REMDESIVIR RETAINS POTENT ACTIVITY AGAINST SARS-CoV-2 VARIANTS OF CONCERN

Background: Recent SARS-CoV-2 variants of concern (VOCs) have shown a progressive loss of sensitivity to monoclonal antibody therapeutics. Remdesivir (RDV) is a nucleotide analog prodrug that targets the viral RNA-dependent RNA polymerase (RdRp) Nsp12 and is approved to treat COVID-19 in hospitalized and non-hospitalized patients. Nsp12 is highly conserved across VOCs to date and RDV antiviral activity against previous VOCs (Alpha to Omicron BA.1) has been maintained. Here, we conduct a structural analysis of Nsp12 substitutions observed in recent Omicron subvariants (BA.2, BA.2.12.1, BA.4, BA.5 and BA.2.75) and assess RDV antiviral activity against clinical isolates and sitedirected mutants (SDMs) in a replicon system. Method(s): The prevalence of Nsp12 substitutions in Omicron subvariants was evaluated by analysis of sequences from the Global Initiative on Sharing Avian Influenza Data (GISAID) EpiCoV database. Structural analysis of identified substitutions was conducted on a prior cryo-electron microscopy-based model of the replication-transcription complex. Antiviral activity against subvariant clinical isolates was assessed by nucleoprotein ELISA in A549-hACE2-TMPRSS2 cells and by SDMs in the replicon system. Result(s): Genomic analysis of >1.4 million Omicron subvariant sequences revealed unique substitutions in Nsp12 compared to the ancestral WA1 strain. Besides P323L, present in all subvariants, G671S was observed in 95.9% of BA.2.75 sequences, F694Y was observed in <=1.9% of BA.4, BA.5 and BA.2.75 sequences, and Y521C was observed in 1.7% of BA.5 sequences. As anticipated, structural analysis of these substitutions showed no direct interaction with the incoming RDV nucleotide triphosphate or the viral RNA. Phenotyping of clinical isolates of Omicron subvariants BA.2, BA.2.12.1, BA.4, BA.5, and BA.2.75 consistently resulted in mean RDV EC50 values of 24.5 nM (BA.2) to 106.0 nM (BA.5). This represented 0.15-to 0.66-fold changes compared to WA1, indicating no loss of in vitro RDV antiviral activity against these VOCs. P323L, G671S, and F694Y were shown previously to have no impact on RDV antiviral activity. Similarly, the individual substitution Y521C showed no change in RDV susceptibility in the SARS-CoV-2 replicon system. Conclusion(s): RDV retained potent in vitro antiviral activity against all tested Omicron VOCs with potencies comparable to the WA1 isolate. These data support the continued use of RDV in patients infected with Omicron subvariants.

LONG NON-CODING RNA REGULATES IFN-I RESPONSE AND SARS-CoV-2 REPLICATION

Background: Infection with SARS-CoV-2 triggers reprogramming through global transcriptomic changes that drive the development of Coronavirus disease 2019 (COVID-19). Although the expression and functions of proteincoding transcripts have been widely studied in SARS-CoV-2 infection, most of the transcriptome consists of non-protein-coding RNAs (ncRNAs). Long noncoding RNAs (lncRNAs), which constitute a large proportion of the transcriptome, regulate immune responses and play prominent roles in health and disease. However, the impact of lncRNAs on SARS-CoV-2 infection is poorly understood. Our study will provide fundamental insights into the role of lncRNAs in SARS-CoV-2 infection. Method(s): We hypothesized that SARS-CoV-2-induced lncRNAs are critical regulators of viral replication and immune response. To test our hypothesis, we identified lncRNAs with significant differential expression in SARS-CoV-2 infected vs. uninfected cells across two cell types (A549-hACE2 and Calu) from published transcriptome data. We silenced the expression of the top lncRNA Bre- AS1 (BA) a human lung epithelial cell model (A549 cells stably expressing hACE2 and hTMPRSS2, A549AT) using lncRNA-specific ASO (lncsi) or negative control (NC) and compared viral replication in lncsi vs. NC cells. BA-silencing (BA-si) increased SARS-CoV-2 replication. and inhibited the expression of antiviral interferon-stimulated genes (ISG). (Tyr 705) pSTAT3 forms suppressor molecular complexes (pSTAT3-pSTAT1 or pSTAT3-PLSCR2) that inhibit ISG transcription. Using molecular methods such as gene-silencing, immunoprecipitation, western blot, and measuring promoter activity, we further show that Bre-AS1 inhibits the phosphorylation of STAT3 and enhances ISG transcription. Result(s): Our data show that cellular lncRNA, Bre-AS1 enhances antiviral interferon-stimulated genes (ISG) expression and inhibits replication of SARSCoV- 2. Our data show that Bre-AS1 inhibits the (Tyr705) phosphorylation of STAT3 that forms ISG repressor complexes (pSTAT3-pSTAT1 or pSTAT3-PLSCR2) and thus enhances ISG transcription. Conclusion(s): Cellular lncRNA Bre-AS1 enhances expression of antiviral interferon-stimulated genes and inhibits the replication of SARS-CoV-2. Our data show that cellular lncRNAs could play significant roles in immune response and viral propagation. Thus, unraveling the mechanisms of lncRNA-mediated regulation of virus replication and immune response may lead to identifying new, highly selective therapeutic targets Bre-AS1 inhibits STAT3 phosphorylation and enhances ISG transcription.

Using ex vivo bioengineered lungs to model pathologies and screening therapeutics

Introduction: More than 8 million lives are claimed annually by various respiratory diseases including lung cancer. While therapeutics is the first line of defence, treatment failure always remains challenging and research studies face a lag of transition from preclinical to clinical phase. This is partly due to the inadequate representation of the preclinical models in clinical trials. In this proof-of-concept study, we sought to use an ex-vivo model to identify lung pathologies and therapeutically screen them in a rodent model. Method(s): Briefly, the heart-lung tissues were extracted and decellularized using a detergent-based decellularization technique. Subsequently, lungs were seeded and cultured (6-10 days) with human cell lines: BEAS-2B, A549, and Calu3, demonstrating healthy lung, cancerous state, and congenital pathologies (cystic fibrosis), respectively. By altering the cultural conditions and exploiting the unique characteristics of these cell lines, we were able to model a variety of novel pathological models in ex vivo, such as advanced-stage solid tumours and the primary phase of infection via SARS-COV2. We also validated the above-mentioned observations by histology and immunofluorescence staining. Another novel part of our study includes a qualitative screening of efficacy and impact of important Therapeutics (anti-neoplastic)- Cisplatin and Wogonin, in our cancer models. Result(s): Using A549 and BEAS-2B cells, we were able to model different stages of Non-small cell lung cancer, qualitatively validated the resemblance to clinical samples and monitor the impact of different therapeutics on these models. The qualitative assessment also demonstrated different levels of cell death depending on the efficacy of the drugs. Contribution to research : Collectively this study demonstrates the remarkable versatility and strength of the ex vivo model in representing important lung pathologies and screening therapeutics in the preclinical phase.

Coagulopathies after vaccination against SARS-CoV-2: The sole solution might lead to another problem

The common reported adverse impacts of COVID-19 vaccination include the injection site's local reaction followed by various non-specific flu-like symptoms. Nevertheless, uncommon cases of vaccine-induced immune thrombotic thrombocytopenia (VITT) and cerebral venous sinus thrombosis (CVST) following viral vector vaccines (ChAdOx1 nCoV-19 vaccine, Ad26.COV2 vaccine) have been reported. This literature review was performed using PubMed and Google Scholar databases using appropriate keywords and their combinations: SARS-CoV-2, adenovirus, spike protein, thrombosis, thrombocytopenia, vaccine-induced immune thrombotic thrombocytopenia (VITT), NF-kappaB, adenoviral vector, platelet factor 4 (PF4), COVID-19 Vaccine, AstraZeneca COVID vaccine, ChAdOx1 nCoV-19 COVID vaccine, AZD1222 COVID vaccine, coagulopathy. The s and titles of each article were assessed by authors for screening and inclusion English reports about post-vaccine CVST and VITT in humans were also collected. Some SARS-CoV-2 vaccines based on viral vector, mRNA, or inactivated SARS-CoV-2 virus have been accepted and are being pragmatic global. Nevertheless, the recent augmented statistics of normally very infrequent types of thrombosis associated with thrombocytopenia have been stated, predominantly in the context of the adenoviral vector vaccine ChAdOx1 nCoV-19 from Astra Zeneca. The numerical prevalence of these side effects seems to associate with this particular vaccine type, i.e., adenoviral vector-based vaccines, but the meticulous molecular mechanisms are still not clear. The present review summarizes the latest data and hypotheses for molecular and cellular mechanisms into one integrated hypothesis demonstrating that coagulopathies, including thromboses, thrombocytopenia, and other associated side effects, are correlated to an interaction of the two components in the COVID-19 vaccine.Copyright © 2022, Iranian Pediatric Hematology and Oncology Society. All rights reserved.

Developing advanced cell culture models to study COVID19-associated pulmonary fibrosis

Patients with severe COVID-19-associated pneumonia are at risk to develop pulmonary fibrosis. To study the underlying mechanisms, we aim to develop advanced cell culture models that reliably reflect COVID-19-related profibrotic microenvironment. To identify key cellular players, we performed pilot immunohistochemistry analysis on lung tissue from COVID-19 patients with fibrosis collected during autopsy. Results revealed diffuse alveolar damage with macrophage infiltration, and myofibroblast accumulation with enriched collagen deposition surrounding the damaged alveoli. To mimic SARS-CoV-2 infection in alveoli, we infected human primary type II alveolar epithelial cells (AEC2) and found enhanced signaling of profibrotic cytokine transforming growth factor beta (TGFbeta) in some donors. To recreate the early fibrotic niche, an alveolar-macrophage-fibroblast (AMF) tri-culture model was established. After infecting AEC2 with SARS-CoV-2 in this AMF model, gene expression analysis provided evidence for fibroblast-to-myofibroblast transition. Furthermore, we found that overexpression of SARS-CoV-2 papain-like protease (PLpro) can promote TGFbeta signaling in HEK293T and A549 cells. After infecting AEC2 with SARS-CoV-2 PLpro lentivirus in the AMF model, we found signs of epithelial-to-mesenchymal transition and fibroblast-to myofibroblast transition. In future studies, we will use a detailed analysis of COVID-19-associated lung fibrosis with other types of lung fibrosis, to further refine COVID-19-related fibrosis models, including lung-on-chip models.

Oral Bioactive Self-Nanoemulsifying Drug Delivery Systems of Remdesivir and Baricitinib: A Paradigmatic Case of Drug Repositioning for Cancer Management.

Oral anticancer therapy mostly faces the challenges of low aqueous solubility, poor and irregular absorption from the gastrointestinal tract, food-influenced absorption, high first-pass metabolism, non-targeted delivery, and severe systemic and local adverse effects. Interest has been growing in bioactive self-nanoemulsifying drug delivery systems (bio-SNEDDSs) using lipid-based excipients within nanomedicine. This study aimed to develop novel bio-SNEDDS to deliver antiviral remdesivir and baricitinib for the treatment of breast and lung cancers. Pure natural oils used in bio-SNEDDS were analyzed using GC-MS to examine bioactive constituents. The initial evaluation of bio-SNEDDSs were performed based on self-emulsification assessment, particle size analysis, zeta potential, viscosity measurement, and transmission electron microscopy (TEM). The single and combined anticancer effects of remdesivir and baricitinib in different bio-SNEDDS formulations were investigated in MDA-MB-231 (breast cancer) and A549 (lung cancer) cell lines. The results from the GC-MS analysis of bioactive oils BSO and FSO showed pharmacologically active constituents, such as thymoquinone, isoborneol, paeonol and p-cymenene, and squalene, respectively. The representative F5 bio-SNEDDSs showed relatively uniform, nanosized (247 nm) droplet along with acceptable zeta potential values (+29 mV). The viscosity of the F5 bio-SNEDDS was recorded within 0.69 Cp. The TEM suggested uniform spherical droplets upon aqueous dispersions. Drug-free, remdesivir and baricitinib-loaded bio-SNEDDSs (combined) showed superior anticancer effects with IC50 value that ranged from 1.9-4.2 µg/mL (for breast cancer), 2.4-5.8 µg/mL (for lung cancer), and 3.05-5.44 µg/mL (human fibroblasts cell line). In conclusion, the representative F5 bio-SNEDDS could be a promising candidate for improving the anticancer effect of remdesivir and baricitinib along with their existing antiviral performance in combined dosage form.

Transcriptional profiles and common genes link lung cancer with the development and severity of COVID-19.

Lung cancer patients with COVID-19 present an increased risk of developing severe disease and, consequently, have poor outcomes. Determining SARS-CoV-2-host interactome in lung cancer cells and tissues, infected or uninfected with SARS-CoV-2, may reveal molecular mechanisms associated with COVID-19 development and severity in lung cancer patients. Here, we integrated transcriptome data of lung tumors from patients with small- or non-small cell lung cancer (SCLC and NSCLC) and normal lung and lung cancer cells infected with SARS-CoV-2. We aimed to characterize molecular mechanisms potentially associated with COVID-19 development and severity in lung cancer patients and to predict the SARS-CoV-2-host cell interactome. We found that the gene expression profiles of lung cell lines infected with SARS-CoV-2 resemble more primary lung tumors than non-malignant lung tissues. In addition, the transcriptomic-based interactome analysis of SCLC and NSCLC revealed increased expression of cancer genes BRCA1 and CENPF, whose proteins are known or predicted to interact with the SARS-CoV-2 spike glycoprotein and helicase, respectively. We also found that TRIB3, a gene coding a putative host-SARS-CoV-2 interacting protein associated with COVID-19 infection, is co-expressed with the up-regulated genes MTHFD2, ADM2, and GPT2 in all tested conditions. Our analysis identified biological processes such as amino acid metabolism and angiogenesis and 22 host mediators of SARS-CoV-2 infection and replication that may contribute to the development and severity of COVID-19 in lung cancers.

Inhibition of coronavirus HCoV-OC43 by targeting the eIF4F complex.

The translation initiation complex 4F (eIF4F) is a rate-limiting factor in protein synthesis. Alterations in eIF4F activity are linked to several diseases, including cancer and infectious diseases. To this end, coronaviruses require eIF4F complex activity to produce proteins essential for their life cycle. Efforts to target coronaviruses by abrogating translation have been largely limited to repurposing existing eIF4F complex inhibitors. Here, we report the results of a high throughput screen to identify small molecules that disrupt eIF4F complex formation and inhibit coronavirus RNA and protein levels. Of 338,000 small molecules screened for inhibition of the eIF4F-driven, CAP-dependent translation, we identified SBI-1232 and two structurally related analogs, SBI-5844 and SBI-0498, that inhibit human coronavirus OC43 (HCoV-OC43; OC43) with minimal cell toxicity. Notably, gene expression changes after OC43 infection of Vero E6 or A549 cells were effectively reverted upon treatment with SBI-5844 or SBI-0498. Moreover, SBI-5844 or SBI-0498 treatment effectively impeded the eIF4F complex assembly, with concomitant inhibition of newly synthesized OC43 nucleocapsid protein and OC43 RNA and protein levels. Overall, we identify SBI-5844 and SBI-0498 as small molecules targeting the eIF4F complex that may limit coronavirus transcripts and proteins, thereby representing a basis for developing novel therapeutic modalities against coronaviruses.

Development of a robust and convenient dual-reporter high-throughput screening assay for SARS-CoV-2 antiviral drug discovery.

Massive efforts on both vaccine development and antiviral research were launched to combat the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We contributed, amongst others, by the development of a high-throughput screening (HTS) antiviral assay against SARS-CoV-2 using a fully automated, high-containment robot system. Here, we describe the development of this novel, convenient and phenotypic dual-reporter virus-cell-based high-content imaging assay using the A549+hACE2+TMPRSS2_mCherry reporter lung carcinoma cell line and an ancestral SARS-CoV-2_Wuhan_mNeonGreen reporter virus. Briefly, by means of clonal selection, a host cell subclone was selected that (i) efficiently supports replication of the reporter virus with high expression, upon infection, of the NeonGreen fluorescent reporter protein, (ii) that is not affected by virus-induced cytopathogenic effects and, (iii) that expresses a strong fluorescent mCherry signal in the nucleus. The selected clone matched these criteria with an infection rate on average of 75% with limited cell death. The average (R)Z'-factors of the assay plates were all >0.8, which indicates a robust assay suitable for HTS purposes. A selection of reference compounds that inhibits SARS-CoV-2 replication in vitro were used to validate this novel dual-reporter assay and confirms the data reported in the literature. This assay is a convenient and powerful tool for HTS of large compound libraries against SARS-CoV-2.

Anti-SARS-CoV-2 Activity of Adamantanes In Vitro and in Animal Models of Infection.

Coronavirus disease 2019 (COVID-19) has had devastating effects worldwide, with particularly high morbidity and mortality in outbreaks on residential care facilities. Amantadine, originally licensed as an antiviral agent for therapy and prophylaxis against influenza A virus, has beneficial effects on patients with Parkinson's disease and is used for treatment of Parkinson's disease, multiple sclerosis, acquired brain injury, and various other neurological disorders. Recent observational data suggest an inverse relationship between the use of amantadine and COVID-19. Adamantanes, including amantadine and rimantadine, are reported to have in vitro activity against severe acute respiratory syndrome coronavirus (SARS-CoV) and, more recently, SARS-CoV-2. We hypothesized that adamantanes have antiviral activity against SARS-CoV-2, including variant strains. To assess the activity of adamantanes against SARS-CoV-2, we used in vitro and in vivo models of infection. We established that amantadine, rimantadine, and tromantadine inhibit the growth of SARS-CoV-2 in vitro in cultured human epithelial cells. While neither rimantadine nor amantadine reduces lung viral titers in mice infected with mouse-adapted SARS-CoV-2, rimantadine significantly reduces viral titers in the lungs in golden Syrian hamsters infected with SARS-CoV-2. In summary, rimantadine has antiviral activity against SARS-CoV-2 in human alveolar epithelial cells and in the hamster model of SARS-CoV-2 lung infection. The evaluation of amantadine or rimantadine in human randomized controlled trials can definitively address applications for the treatment or prevention of COVID-19.

Quercitrin loaded cyclodextrin based nanosponge as a promising approach for management of lung cancer and COVID-19.

Lung cancer and pandemic acute respiratory disease, COVID-19, are examples of the most worldwide widespread diseases. The aim of the current study is to develop cyclodextrin based nanosponge (CD-NS) for loading the flavonoid drug, quercitrin (QCT). This is to improve its solubility in an attempt to enhance its activity against lung cancer as well as SARS-CoV-2 virus responsible for COVID-19. Preparation of CD-NS was performed by ultrasound-assisted synthesis method. Two CDs were employed, namely, ß cyclodextrin (ßCD) and 2-hydroxy propyl-ß-cyclodextrin (2-HPßCD) that were crosslinked with diphenyl carbonate, one at a time. QCT loaded CD-NS revealed entrapment efficiency and particle size ranged between 94.17 and 99.03% and 97.10-325.90 nm, respectively. QCT loaded 2-HPßCD-NS revealed smaller particle size compared with that of QCT loaded ßCD-NS. Zeta potential absolute values of the prepared formulations were >20 mV, indicating physically stable nanosystems. The selected formulations were investigated by Fourier transform infrared spectroscopy, X-ray powder diffraction and scanning electron microscopy which proved the formation of QCT loaded CD-NS exhibiting porous structure. QCT exhibited partial and complete amorphization in ßCD-NS and 2-HPßCD-NS, respectively. In vitro release revealed an improved release of QCT from CD-NS formulations. The biological activity of free QCT and QCT loaded CD-NS was investigated against lung cancer cell line A549 as well as SARS-CoV-2 virus. The results revealed that IC50 values of free QCT against lung cancer cell line A549 and SARS-CoV-2 were higher than those exhibited by QCT loaded CD-NS by 1.57-5.35 and 5.95-26.95 folds, respectively. QCT loaded 2-HPßCD-NS revealed enhanced in vitro release and superior biological activity compared with QCT loaded ßCD-NS.

The SARS-CoV-2 S1 Spike Protein Promotes MAPK and NF-kB Activation in Human Lung Cells and Inflammatory Cytokine Production in Human Lung and Intestinal Epithelial Cells.

The coronavirus disease 2019 (COVID-19) pandemic began in January 2020 in Wuhan, China, with a new coronavirus designated SARS-CoV-2. The principal cause of death from COVID-19 disease quickly emerged as acute respiratory distress syndrome (ARDS). A key ARDS pathogenic mechanism is the "Cytokine Storm", which is a dramatic increase in inflammatory cytokines in the blood. In the last two years of the pandemic, a new pathology has emerged in some COVID-19 survivors, in which a variety of long-term symptoms occur, a condition called post-acute sequelae of COVID-19 (PASC) or "Long COVID". Therefore, there is an urgent need to better understand the mechanisms of the virus. The spike protein on the surface of the virus is composed of joined S1-S2 subunits. Upon S1 binding to the ACE2 receptor on human cells, the S1 subunit is cleaved and the S2 subunit mediates the entry of the virus. The S1 protein is then released into the blood, which might be one of the pivotal triggers for the initiation and/or perpetuation of the cytokine storm. In this study, we tested the hypothesis that the S1 spike protein is sufficient to activate inflammatory signaling and cytokine production, independent of the virus. Our data support a possible role for the S1 spike protein in the activation of inflammatory signaling and cytokine production in human lung and intestinal epithelial cells in culture. These data support a potential role for the SARS-CoV-2 S1 spike protein in COVID-19 pathogenesis and PASC.

PCL- And Gelatin-based Electrospun Biological Scaffolds For In Vitro Lung Tissue Engineering

Purpose/Objectives: Acute and chronic respiratory diseases constitute a substantial socioeconomic burden on a global scale, as made abundantly clear in the last two years with the rampant coronavirus disease 2019 (COVID-19) pandemic. Alas, the development of new therapies for pathological respiratory conditions has been hindered by the inadequacy of current preclinical models, which often fail to provide reliable predictions on drug safety and efficacy in humans. In particular, considerable anatomical and physiological differences between the respiratory systems of commonly used animal models and humans are one of the main issues leading to high drug attrition and clinical failure rates. Accordingly, the generation of physiologically relevant preclinical lung models for early drug development and pharmaceutical research is urgently needed. In this work, poly(ϵ-caprolactone) (PCL) and gelatin were used as raw materials to produce electrospun scaffolds for in vitro lung tissue engineering, in order to generate human biomimetic platforms for preclinical drug safety and efficacy testing. Methodology: PCL and gelatin were mixed at varying volume ratios: 1:0 (PP), 6:1 (PPG61), 4:1 (PPG41), and 2:1 (PPG21), so as to determine the optimal gelatin concentration for cell adhesion and growth. Poly(vinylpyrrolidone) (PVP) was added to every polymer mixture to facilitate the electrospinning process, and electrospun fibrous matrices were fabricated using a needleless electrospinning technique. Scaffold morphology, chemical composition, and wettability were characterized with scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and water contact angle analysis, respectively. Biocompatibility testing was performed using human bronchial (16HBE) and alveolar (A549) epithelial cell lines, consisting of cell metabolic activity, proliferation, and adhesion evaluation over two weeks of in vitro culture. Results: All polymer blends resulted in the formation of electrospun scaffolds with a nanofibrous structure. The addition of gelatin in PPG61 scaffolds improved fiber morphology compared to PP formulations, but increasing proportions of this polymer in PPG41 and PPG21 mats caused a larger number of defects, such as beading and branching. FTIR analysis confirmed the presence of PCL and PVP in PP scaffolds, as well as the addition of gelatin in all PPG blends. Moreover, as expected, all scaffolds were hydrophilic, with water contact angles below 90°, being suitable for protein adsorption and cell adhesion. Regarding 16HBE and A549 cell viability, surprisingly, no major differences were found between the different formulations over the two-week culture period, showing that all polymer blends were equally capable of promoting cell adhesion and growth. While PP scaffolds significantly outperformed PPG electrospun mats in early timepoints, no such differences were identified at the end of the experimental period. Conclusion/Significance: These results suggested that PCL, PVP, and/or gelatin blend electrospun scaffolds are conducive to lung epithelial cell adhesion and proliferation. Nevertheless, further studies investigating epithelial cell differentiation and function should be conducted to fully assess the suitability of these biomaterials as platforms for in vitro lung tissue engineering.

Nicotine in Combination with SARS-CoV-2 Affects Cells Viability, Inflammatory Response and Ultrastructural Integrity.

The aims of our study are to: (i) investigate the ability of nicotine to modulate the expression level of inflammatory cytokines in A549 cells infected with SARS-CoV-2; (ii) elucidate the ultrastructural features caused by the combination nicotine+SARS-CoV-2; and (iii) demonstrate the mechanism of action. In this study, A549 cells pretreated with nicotine were either exposed to LPS or poly(I:C), or infected with SARS-CoV-2. Treated and untreated cells were analyzed for cytokine production, cytotoxicity, and ultrastructural modifications. Vero E6 cells were used as a positive reference. Cells pretreated with nicotine showed a decrease of IL6 and TNFα in A549 cells induced by LPS or poly(I:C). In contrast, cells exposed to SARS-CoV-2 showed a high increase of IL6, IL8, IL10 and TNFα, high cytopathic effects that were dose- and time-dependent, and profound ultrastructural modifications. These modifications were characterized by membrane ruptures and fragmentation, the swelling of cytosol and mitochondria, the release of cytoplasmic content in extracellular spaces (including osmiophilic granules), the fragmentation of endoplasmic reticulum, and chromatin disorganization. Nicotine increased SARS-CoV-2 cytopathic effects, elevating the levels of inflammatory cytokines, and inducing severe cellular damage, with features resembling pyroptosis and necroptosis. The protective role of nicotine in COVID-19 is definitively ruled out.

Caged Dexamethasone/Quercetin Nanoparticles, Formed of the Morphogenetic Active Inorganic Polyphosphate, are Strong Inducers of MUC5AC.

Inorganic polyphosphate (polyP) is a widely distributed polymer found from bacteria to animals, including marine species. This polymer exhibits morphogenetic as well as antiviral activity and releases metabolic energy after enzymatic hydrolysis also in human cells. In the pathogenesis of the coronavirus disease 2019 (COVID-19), the platelets are at the frontline of this syndrome. Platelets release a set of molecules, among them polyP. In addition, the production of airway mucus, the first line of body defense, is impaired in those patients. Therefore, in this study, amorphous nanoparticles of the magnesium salt of polyP (Mg-polyP-NP), matching the size of the coronavirus SARS-CoV-2, were prepared and loaded with the secondary plant metabolite quercetin or with dexamethasone to study their effects on the respiratory epithelium using human alveolar basal epithelial A549 cells as a model. The results revealed that both compounds embedded into the polyP nanoparticles significantly increased the steady-state-expression of the MUC5AC gene. This mucin species is the major mucus glycoprotein present in the secreted gel-forming mucus. The level of gene expression caused by quercetin or with dexamethasone, if caged into polyP NP, is significantly higher compared to the individual drugs alone. Both quercetin and dexamethasone did not impair the growth-supporting effect of polyP on A549 cells even at concentrations of quercetin which are cytotoxic for the cells. A possible mechanism of the effects of the two drugs together with polyP on mucin expression is proposed based on the scavenging of free oxygen species and the generation of ADP/ATP from the polyP, which is needed for the organization of the protective mucin-based mucus layer.

Which East Asian herbal medicines can decrease viral infections?

Introduction In the light of the ongoing corona and influenza virus public health crisis, traditional East Asian herbal medicines with anti-viral activities might be an option in therapy. Methods Literature research on anti-viral effects of traditional East Asian medicine was performed. Results In patients with uncomplicated upper respiratory tract infection, treatment with Andrographis paniculata (Jap. Senshinren) extract resulted in 53% of improvement compared with placebo. When 158 common cold patients took 1.2 g of dried extract of A. paniculata for 5 days, nasal secretion, sore throat and sleep disorder were improved [1]. Ding Y et al. [2] demonstrated that mice infected with influenza A and treated with extract of A. paniculata improved body weight, lung function and showed reduced inflammation. In Japan, Kampo prescriptions like Maoto as well as its variant Maoto-ka-senshinren ([Tab. 1]), were examined for anti-viral activity [3] [4]. Nabeshima et al. [5] investigated Maoto for the treatment of influenza in a randomized trial in comparison with oseltamivir and zanamivir. No significant differences for total symptom score and no severe adverse events were found. In A549 cells infected with influenza A virus that were treated with Maoto, the virus titre in the supernatant, intracellular viral proteins and viral RNA were significantly reduced. Maoto also inhibited the uncoating of the influenza virus [6]. Conclusion In Japan, Maoto is regarded as a suitable medication for influenza. Maoto-ka-senshinren ([Tab. 1]) may present a promising therapy option for influenza and potentially COVID-19.

Differential transcriptomic landscapes of SARS-CoV-2-infected and bystander lung cells reveal proviral genes selectively upregulated by viral replication

Bulk transcriptomic analyses of virus-cell interactions are commonly performed on mixed populations of infected and uninfected bystander cells and may thus lead to inaccurate interpretations. Moreover, they generally focus on the expression of the coding genome and not on the total transcriptome, which is largely composed of long non-coding RNAs (lncRNAs). We performed polyA+ and whole transcriptome analysis of lung epithelial A549 cells infected with SARS-CoV-2, which were sorted based on the expression of the viral protein Spike (S). To increase the sequencing depth and ameliorate the robustness of the analysis, the samples were depleted of viral transcripts, which constituted up to 85% of total reads in the S-positive cells. Results highlighted a high number of down-regulated genes upon infection, an indication of massive host transcription shutdown. We also noticed an increased level of intronic reads in infected cells as compared to control cells, suggesting a defect in mRNA splicing. Among the upregulated coding genes in S-positive cells, we recovered candidates previously identified by analysis performed on non-sorted cells, such as CXCL8 and CCL20, but also novel candidates, including IL- 32, ITGAM and the down-regulated FEN1. Comparison of mRNA abundances of few coding, non-coding and unannotated genes between non-sorted cells and sorted ones confirmed the accuracy of the approach. We also observed that S-negative bystander cells and mock-infected control cells exhibited very similar transcriptomic profiles. This was not due to a lack of communication between infected and bystander cells: transcripts related to inflammatory cytokines underwent normal splicing and maturation in infected cells, with concomitant high levels of protein secretion. The observed lack of major transcriptomic changes in the bystander population can be linked to the insufficient interferon response in infected cells. Finally, we explored the functional implications of genes selectively upregulated in the infected subpopulation and observed previously uncharacterized proviral activities of lncRNA ADIRFAS1 and endogenous Interleukin 32 (IL-32), making them attractive targets for putative therapeutic strategies. Thus, analyzing the whole transcriptome of pure populations of infected lung cells allowed the accurate identification of cellular functions that are directly affected by infection and recovery of coding and non-coding genes relevant for SARS-CoV-2 replication.

A Newly Engineered A549 Cell Line Expressing ACE2 and TMPRSS2 Is Highly Permissive to SARS-CoV-2, Including the Delta and Omicron Variants.

New variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continue to emerge, causing surges, breakthrough infections, and devastating losses-underscoring the importance of identifying SARS-CoV-2 antivirals. A simple, accessible human cell culture model permissive to SARS-CoV-2 variants is critical for identifying and assessing antivirals in a high-throughput manner. Although human alveolar A549 cells are a valuable model for studying respiratory virus infections, they lack two essential host factors for SARS-CoV-2 infection: angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2). SARS-CoV-2 uses the ACE2 receptor for viral entry and TMPRSS2 to prime the SARS-CoV-2 spike protein, both of which are negligibly expressed in A549 cells. Here, we report the generation of a suitable human cell line for SARS-CoV-2 studies by transducing human ACE2 and TMPRSS2 into A549 cells. We show that subclones highly expressing ACE2 and TMPRSS2 ("ACE2plus" and the subclone "ACE2plusC3") are susceptible to infection with SARS-CoV-2, including the delta and omicron variants. These subclones express more ACE2 and TMPRSS2 transcripts than existing commercial A549 cells engineered to express ACE2 and TMPRSS2. Additionally, the antiviral drugs EIDD-1931, remdesivir, nirmatrelvir, and nelfinavir strongly inhibit SARS-CoV-2 variants in our infection model. Our data show that ACE2plusC3 cells are highly permissive to SARS-CoV-2 infection and can be used to identify anti-SARS-CoV-2 drugs.