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1.
Biomolecules ; 12(2)2022 02 15.
Article in English | MEDLINE | ID: covidwho-1715101

ABSTRACT

Protein-based carriers are promising vehicles for the intracellular delivery of therapeutics. In this study, we designed and studied adenovirus protein fiber constructs with potential applications as carriers for the delivery of protein and nanoparticle cargoes. We used as a basic structural framework the fibrous shaft segment of the adenovirus fiber protein comprising of residues 61-392, connected to the fibritin foldon trimerization motif at the C-terminal end. A fourteen-amino-acid biotinylation sequence was inserted immediately after the N-terminal, His-tagged end of the construct in order to enable the attachment of a biotin moiety in vivo. We report herein that this His-tag biotinylated construct folds into thermally and protease-stable fibrous nanorods that can be internalized into cells and are not cytotoxic. Moreover, they can bind to proteins and nanoparticles through the biotin-streptavidin interaction and mediate their delivery to cells. We demonstrate that streptavidin-conjugated gold nanoparticles can be transported into NIH3T3 fibroblast and HeLa cancer cell lines. Furthermore, two streptavidin-conjugated model proteins, alkaline phosphatase and horseradish peroxidase can be delivered into the cell cytoplasm in their enzymatically active form. This work is aimed at establishing the proof-of-principle for the rational engineering of diverse functionalities onto the initial protein structural framework and the use of adenovirus fiber-based proteins as nanorods for the delivery of nanoparticles and model proteins. These constructs could constitute a stepping stone for the development of multifunctional and modular fibrous nanorod platforms that can be tailored to applications at the sequence level.


Subject(s)
Viral Proteins , Adenoviridae/chemistry , Animals , Biotin/chemistry , Biotin/metabolism , Gold/chemistry , HeLa Cells , Humans , Metal Nanoparticles/chemistry , Mice , NIH 3T3 Cells , Streptavidin/chemistry , Viral Proteins/chemistry
2.
Int J Mol Sci ; 22(16)2021 Aug 10.
Article in English | MEDLINE | ID: covidwho-1662670

ABSTRACT

Hypoxic conditions induce the activation of hypoxia-inducible factor-1α (HIF-1α) to restore the supply of oxygen to tissues and cells. Activated HIF-1α translocates into the nucleus and binds to hypoxia response elements to promote the transcription of target genes. Cathepsin L (CTSL) is a lysosomal protease that degrades cellular proteins via the endolysosomal pathway. In this study, we attempted to determine if CTSL is a hypoxia responsive target gene of HIF-1α, and decipher its role in melanocytes in association with the autophagic pathway. The results of our luciferase reporter assay showed that the expression of CTSL is transcriptionally activated through the binding of HIF1-α at its promoter. Under autophagy-inducing starvation conditions, HIF-1α and CTSL expression is highly upregulated in melan-a cells. The mature form of CTSL is closely involved in melanosome degradation through lysosomal activity upon autophagosome-lysosome fusion. The inhibition of conversion of pro-CTSL to mature CTSL leads to the accumulation of gp100 and tyrosinase in addition to microtubule-associated protein 1 light chain 3 (LC3) II, due to decreased lysosomal activity in the autophagic pathway. In conclusion, we have identified that CTSL, a novel target of HIF-1α, participates in melanosome degradation in melanocytes through lysosomal activity during autophagosome-lysosome fusion.


Subject(s)
Cathepsin L/physiology , Hypoxia-Inducible Factor 1, alpha Subunit/physiology , Melanosomes/metabolism , Animals , Cathepsin L/genetics , Cell Hypoxia/genetics , Cells, Cultured , Gene Expression Regulation , Melanocytes/metabolism , Mice , NIH 3T3 Cells
3.
J Ethnopharmacol ; 283: 114701, 2022 Jan 30.
Article in English | MEDLINE | ID: covidwho-1446835

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: Xuanfei Baidu Decoction (XFBD), one of the "three medicines and three prescriptions" for the clinically effective treatment of COVID-19 in China, plays an important role in the treatment of mild and/or common patients with dampness-toxin obstructing lung syndrome. AIM OF THE STUDY: The present work aims to elucidate the protective effects and the possible mechanism of XFBD against the acute inflammation and pulmonary fibrosis. METHODS: We use TGF-ß1 induced fibroblast activation model and LPS/IL-4 induced macrophage inflammation model as in vitro cell models. The mice model of lung fibrosis was induced by BLM via endotracheal drip, and then XFBD (4.6 g/kg, 9.2 g/kg) were administered orally respectively. The efficacy and molecular mechanisms in the presence or absence of XFBD were investigated. RESULTS: The results proved that XFBD can effectively inhibit fibroblast collagen deposition, down-regulate the level of α-SMA and inhibit the migration of fibroblasts. IL-4 induced macrophage polarization was also inhibited and the secretions of the inflammatory factors including IL6, iNOS were down-regulated. In vivo experiments, the results proved that XFBD improved the weight loss and survival rate of the mice. The XFBD high-dose administration group had a significant effect in inhibiting collagen deposition and the expression of α-SMA in the lungs of mice. XFBD can reduce bleomycin-induced pulmonary fibrosis by inhibiting IL-6/STAT3 activation and related macrophage infiltration. CONCLUSIONS: Xuanfei Baidu Decoction protects against macrophages induced inflammation and pulmonary fibrosis via inhibiting IL-6/STAT3 signaling pathway.


Subject(s)
COVID-19/drug therapy , Drugs, Chinese Herbal , Inflammation/drug therapy , Macrophages/drug effects , SARS-CoV-2 , Signal Transduction/drug effects , Animals , Cell Survival/drug effects , Drugs, Chinese Herbal/pharmacology , Drugs, Chinese Herbal/therapeutic use , Fibroblasts/drug effects , Gene Expression Regulation/drug effects , Gene Regulatory Networks , Humans , Interleukin-6/antagonists & inhibitors , Interleukin-6/genetics , Interleukin-6/metabolism , Male , Mice , Mice, Inbred C57BL , NIH 3T3 Cells , Phytotherapy , Pulmonary Fibrosis/pathology , Pulmonary Fibrosis/prevention & control , RAW 264.7 Cells , STAT3 Transcription Factor/antagonists & inhibitors , STAT3 Transcription Factor/genetics , STAT3 Transcription Factor/metabolism
4.
Nat Commun ; 12(1): 3431, 2021 06 08.
Article in English | MEDLINE | ID: covidwho-1262001

ABSTRACT

The current COVID-19 pandemic is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We demonstrate that despite the large size of the viral RNA genome (~30 kb), infectious full-length cDNA is readily assembled in vitro by a circular polymerase extension reaction (CPER) methodology without the need for technically demanding intermediate steps. Overlapping cDNA fragments are generated from viral RNA and assembled together with a linker fragment containing CMV promoter into a circular full-length viral cDNA in a single reaction. Transfection of the circular cDNA into mammalian cells results in the recovery of infectious SARS-CoV-2 virus that exhibits properties comparable to the parental virus in vitro and in vivo. CPER is also used to generate insect-specific Casuarina virus with ~20 kb genome and the human pathogens Ross River virus (Alphavirus) and Norovirus (Calicivirus), with the latter from a clinical sample. Additionally, reporter and mutant viruses are generated and employed to study virus replication and virus-receptor interactions.


Subject(s)
Reverse Genetics , SARS-CoV-2/genetics , Amino Acid Sequence , Animals , Base Sequence , Chlorocebus aethiops , Culicidae/virology , Furin/metabolism , Genome, Viral , HEK293 Cells , Humans , Mice , Mutation/genetics , NIH 3T3 Cells , Polymerase Chain Reaction , RAW 264.7 Cells , Receptors, Virus/metabolism , Vero Cells , Viral Proteins/chemistry , Virus Replication
5.
Biointerphases ; 16(1): 011006, 2021 01 28.
Article in English | MEDLINE | ID: covidwho-1066780

ABSTRACT

The novel coronavirus caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has reached more than 160 countries and has been declared a pandemic. SARS-CoV-2 infects host cells by binding to the angiotensin-converting enzyme 2 (ACE-2) surface receptor via the spike (S) receptor-binding protein (RBD) on the virus envelope. Global data on a similar infectious disease spread by SARS-CoV-1 in 2002 indicated improved stability of the virus at lower temperatures facilitating its high transmission in the community during colder months (December-February). Seasonal viral transmissions are strongly modulated by temperatures, which can impact viral trafficking into host cells; however, an experimental study of temperature-dependent activity of SARS-CoV-2 is still lacking. We mimicked SARS-CoV-2 with polymer beads coated with the SARS-CoV-2 S protein to study the effect of seasonal temperatures on the binding of virus-mimicking nanospheres to lung epithelia. The presence of the S protein RBD on nanosphere surfaces led to binding by Calu-3 airway epithelial cells via the ACE-2 receptor. Calu-3 and control fibroblast cells with S-RBD-coated nanospheres were incubated at 33 and 37 °C to mimic temperature fluctuations in the host respiratory tract, and we found no temperature dependence in contrast to nonspecific binding of bovine serum ablumin-coated nanospheres. Moreover, the ambient temperature changes from 4 to 40 °C had no effect on S-RBD-ACE-2 ligand-receptor binding and minimal effect on the S-RBD protein structure (up to 40 °C), though protein denaturing occurred at 51 °C. Our results suggest that ambient temperatures from 4 to 40 °C have little effect on the SARS-CoV-2-ACE-2 interaction in agreement with the infection data currently reported.


Subject(s)
COVID-19/metabolism , Coated Materials, Biocompatible , Epithelial Cells/metabolism , Lung/metabolism , Nanospheres , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Temperature , Angiotensin-Converting Enzyme 2/metabolism , Animals , Cell Line, Tumor , Coated Materials, Biocompatible/chemistry , Coated Materials, Biocompatible/metabolism , Epithelial Cells/pathology , Epithelial Cells/virology , Humans , Lung/pathology , Lung/virology , Mice , NIH 3T3 Cells , SARS-CoV-2/chemistry , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolism
6.
Cell Death Differ ; 28(5): 1610-1626, 2021 05.
Article in English | MEDLINE | ID: covidwho-957566

ABSTRACT

The receptor-interacting serine/threonine protein kinase 1 (RIPK1) is a key mediator of regulated cell death and inflammation. Recent studies suggest that RIPK1 inhibition would fundamentally improve the therapy of RIPK1-dependent organ damage in stroke, myocardial infarction, kidney failure, and systemic inflammatory response syndrome. Additionally, it could ameliorate or prevent multi-organ failure induced by cytokine release in the context of hyperinflammation, as seen in COVID-19 patients. Therefore, we searched for a RIPK1 inhibitor and present the aromatic antiepileptic and FDA-approved drug primidone (Liskantin®) as a potent inhibitor of RIPK1 activation in vitro and in a murine model of TNFα-induced shock, which mimics the hyperinflammatory state of cytokine release syndrome. Furthermore, we detected for the first time RIPK1 activation in the respiratory tract epithelium of hospitalized patients who tested positive for SARS-CoV-2 infection. Our data provide a strong rationale for evaluating the drug primidone in conditions of hyperinflammation in humans.


Subject(s)
COVID-19/enzymology , Primidone/pharmacology , Receptor-Interacting Protein Serine-Threonine Kinases/metabolism , SARS-CoV-2/metabolism , Animals , COVID-19/drug therapy , COVID-19/pathology , Cell Death/drug effects , HEK293 Cells , HT29 Cells , Humans , Inflammation/drug therapy , Inflammation/enzymology , Inflammation/pathology , Jurkat Cells , Mice , NIH 3T3 Cells , U937 Cells
7.
J Clin Immunol ; 41(2): 335-344, 2021 02.
Article in English | MEDLINE | ID: covidwho-947042

ABSTRACT

In 2014, we reported two siblings with a rare congenital disorder of glycosylation due to mutations in mannosyl-oligosaccharide glucosidase (MOGS). The glycan alteration derived from this disease resulted in an in vitro infection resistance to particular enveloped, N-glycosylation-dependent viruses as influenza and HIV. As part of the global effort to find safe and effective antiviral therapies for Covid-19, we assessed the in vitro activity of the FDA-approved α-glucosidase inhibitor miglustat against SARS-CoV-2. Expression plasmids encoding SARS-CoV-2 spike (S) and human ACE2 glycoproteins (GP) were tested to evaluate N-glycan modifications induced by α-glucosidase inhibition. Immunoprecipitation was used to assess binding between these two GP. Cell-to-cell fusion was assessed by immunofluorescence of cocultures of SARS-CoV-2 S and ACE2-expressing cells. Miglustat effect on immune response was tested by measuring cytokine release from PBMC exposed to purified SARS-CoV-2 S. In our overexpression system, miglustat successfully and specifically modified N-glycans in both SARS-CoV-2 S and its main receptor ACE2. Binding between these two GP was not affected by glycan modifications. A surrogate marker for viral cytopathic effect, measured as receptor-dependent SARS-CoV-2 S-driven cell-to-cell fusion, was not disrupted by miglustat treatment. This observation was further confirmed in MOGS-null transfected cells. Miglustat produced no statistically significant effects on cytokine production following SARS-CoV-2 S glycoprotein stimulation of PBMC. Our work shows that despite clear N-glycan alteration in the presence of miglustat, the functions of the Covid-19-related glycoproteins studied were not affected, making it unlikely that miglustat can change the natural course of the disease.


Subject(s)
COVID-19/metabolism , COVID-19/virology , Host-Pathogen Interactions , Polysaccharides/metabolism , SARS-CoV-2 , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Animals , Cytokines/metabolism , Estrogen Receptor alpha/metabolism , Glycosylation , HEK293 Cells , Humans , Mice , NIH 3T3 Cells , Peptidyl-Dipeptidase A/genetics , Peptidyl-Dipeptidase A/metabolism
8.
Mol Cell ; 80(6): 1123-1134.e4, 2020 12 17.
Article in English | MEDLINE | ID: covidwho-939163

ABSTRACT

Analyzing the genome of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from clinical samples is crucial for understanding viral spread and evolution as well as for vaccine development. Existing RNA sequencing methods are demanding on user technique and time and, thus, not ideal for time-sensitive clinical samples; these methods are also not optimized for high performance on viral genomes. We developed a facile, practical, and robust approach for metagenomic and deep viral sequencing from clinical samples. We demonstrate the utility of our approach on pharyngeal, sputum, and stool samples collected from coronavirus disease 2019 (COVID-19) patients, successfully obtaining whole metatranscriptomes and complete high-depth, high-coverage SARS-CoV-2 genomes with high yield and robustness. With a shortened hands-on time from sample to virus-enriched sequencing-ready library, this rapid, versatile, and clinic-friendly approach will facilitate molecular epidemiology studies during current and future outbreaks.


Subject(s)
COVID-19/genetics , Genome, Viral , High-Throughput Nucleotide Sequencing , RNA, Viral/genetics , SARS-CoV-2/genetics , Whole Genome Sequencing , Animals , Humans , Mice , NIH 3T3 Cells , RNA, Viral/metabolism , SARS-CoV-2/metabolism
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