scholarly journals Hypertonic saline and aprotinin based blockage of SARS-CoV-2 specific furin site cleavage by inhibition of nasal protease activity

2021 ◽  
Author(s):  
Adam Li ◽  
Clarissa Ting Li
Keyword(s):  
Epithelial Cells ◽  
Nasal Cavity ◽  
Hypertonic Saline ◽  
Human Body ◽  
Protease Activity ◽  
Nasal Swab ◽  
Cell Entry ◽  
Wild Type ◽  
Nasal Epithelial Cells

SARS-CoV-2 enters into the human body mainly through the nasal epithelial cells. Cell entry of SARS-CoV-2 needs to be pre-activated by S1/S2 boundary furin motif cleavage by furin and/or relevant proteases. It is important to locally block SARS-CoV-2 S1/S2 site cleavage caused by furin and other relevant protease activity in the nasal cavity. We tested hypertonic saline and aprotinin-based blockage of SARS-CoV-2 specific furin site cleavage by furin, trypsin and nasal swab samples containing nasal proteases. Our results show that saline and aprotinin block SARS-Cov-2 specific furin site cleavage and that a saline and aprotinin combination could significantly reduce SARS-Cov-2 wild-type and P681R mutant furin site cleavage by inhibition of nasal protease activity.

scholarly journals Identification of bistable populations of Porphyromonas gingivalis that differ in epithelial cell invasion

Microbiology ◽  
2010 ◽  
Vol 156 (10) ◽  
pp. 3052-3064 ◽  
Author(s):  
S. Suwannakul ◽  
G. P. Stafford ◽  
S. A. Whawell ◽  
C. W. I. Douglas
Keyword(s):  
Epithelial Cells ◽  
Porphyromonas Gingivalis ◽  
Cell Invasion ◽  
Protease Activity ◽  
Periodontal Pathogen ◽  
Wild Type ◽  
Oral Epithelial Cells ◽  
Specific Protease ◽  
Oral Epithelial ◽  
First Time

Bistable populations of bacteria give rise to two or more subtypes that exhibit different phenotypes. We have explored whether the periodontal pathogen Porphyromonas gingivalis exhibits bistable invasive phenotypes. Using a modified cell invasion assay, we show for the first time that there are two distinct subtypes within a population of P. gingivalis strains NCTC 11834 and W50 that display differences in their ability to invade oral epithelial cells. The highly invasive subtype invades cells at 10–30-fold higher levels than the poorly invasive subtype and remains highly invasive for approximately 12–16 generations. Analysis of the gingipain activity of these subtypes revealed that the highly invasive type had reduced cell-associated arginine-specific protease activity. The role of Arg-gingipain activity in invasion was verified by enhancement of invasion by rgpAB mutations and by inclusion of an Arg-gingipain inhibitor in invasion assays using wild-type bacteria. In addition, a population of ΔrgpAB bacteria did not contain a hyperinvasive subtype. Screening of the protease activity of wild-type populations of both strains identified high and low protease subtypes which also showed a corresponding reduction or enhancement, respectively, of invasive capabilities. Microarray analysis of these bistable populations revealed a putative signature set of genes that includes oxidative stress resistance and iron transport genes, and which might be critical to invasion of or survival within epithelial cells.

Effect of hypo-, iso- and hypertonic saline irrigation on secretory mucins and morphology of cultured human nasal epithelial cells

2005 ◽  
Vol 125 (12) ◽  
pp. 1296-1300 ◽  
Author(s):  
Chang-Hoon Kim ◽  
Mee Hyun Song ◽  
Young Eun Ahn ◽  
Jeung-Gweon Lee ◽  
Joo-Heon Yoon
Keyword(s):  
Epithelial Cells ◽  
Hypertonic Saline ◽  
Saline Irrigation ◽  
Nasal Epithelial Cells ◽  
Human Nasal Epithelial Cells

Hypertonic saline solution stimulated CLC-3 production in primary cultured human nasal epithelial cells

2008 ◽  
Vol 35 (1) ◽  
pp. 47-51
Author(s):  
Hua-bin Li ◽  
Jian-bo Shi ◽  
Fang Cao ◽  
Lei Cheng ◽  
Wei-ping Wen ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Hypertonic Saline ◽  
Saline Solution ◽  
Hypertonic Saline Solution ◽  
Nasal Epithelial Cells ◽  
Human Nasal Epithelial Cells

Localisation of wild-type and ?F508-CFTR in nasal epithelial cells

2001 ◽  
Vol 443 (0) ◽  
pp. S117-S120 ◽  
Author(s):  
Dormer R. ◽  
McNeilly C. ◽  
Morris M. ◽  
Pereira M. ◽  
Doull I. ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Wild Type ◽  
Nasal Epithelial Cells

scholarly journals Single-cell RNA expression profiling of ACE2, the putative receptor of Wuhan 2019-nCoV, in the nasal tissue

2020 ◽  
Author(s):  
Chao Wu ◽  
Shufa Zheng ◽  
Yu Chen ◽  
Min Zheng
Keyword(s):  
Epithelial Cells ◽  
Single Cell ◽  
Nasal Swab ◽  
Throat Swab ◽  
Strategy Development ◽  
Rna Expression ◽  
Alveolar Cells ◽  
Nasal Epithelial Cells ◽  
Nasal Tissue ◽  
Novel Coronavirus

AbstractA novel coronavirus (2019-nCoV) was first identified in Wuhan, Hubei Province, and then spreads to the other Provinces of China. WHO decides to determine a Public Health Emergency of International Concern (PHEIC) of 2019-nCoV. 2019-nCov was reported to share the same receptor, Angiotensin-converting enzyme 2 (ACE2), with SARS-Cov. Here based on the public single-cell RNA-Seq datasets, we analyzed the ACE2 RNA expression profile in the tissues at different locations of the respiratory tract. The result indicates that the ACE2 expression appears in nasal epithelial cells. We found that the size of this population of ACE2-expressing nasal epithelial cells is comparable with the size of the population of ACE2-expression type II alveolar cells (AT2) in the Asian sample reported by Yu Zhao et al. We further detected 2019-nCoV by polymerase chain reaction (PCR) from the nasal-swab and throat-swab of seven suspected cases. We found that 2019-nCoV tends to have a higher concentration in the nasal-swab comparing to the throat-swab, which could attribute to the ACE2-expressing nasal epithelial cells. We hope this study could be informative for virus-prevention strategy development, especially the treatment of nasal mucus.

scholarly journals Fluticasone Propionate Suppresses Poly(I:C)-Induced ACE2 in Primary Human Nasal Epithelial Cells

2021 ◽  
Vol 11 ◽  
Author(s):  
Akira Nakazono ◽  
Yuji Nakamaru ◽  
Mahnaz Ramezanpour ◽  
Takeshi Kondo ◽  
Masashi Watanabe ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Fluticasone Propionate ◽  
Nasal Mucosa ◽  
Fold Change ◽  
Innate Immune ◽  
Cell Entry ◽  
Poly I:C ◽  
Nasal Epithelial Cells ◽  
Tlr Agonists ◽  
Human Nasal Epithelial Cells

BackgroundFrom the first detection in 2019, SARS-CoV-2 infections have spread rapidly worldwide and have been proven to cause an urgent and important health problem. SARS-CoV-2 cell entry depends on two proteins present on the surface of host cells, angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine 2 (TMPRSS2). The nasal cavity is thought to be one of the initial sites of infection and a possible reservoir for dissemination within and between individuals. However, it is not known how the expression of these genes is regulated in the nasal mucosa.ObjectiveIn this study, we examined whether the expression of ACE2 and TMPRSS2 is affected by innate immune signals in the nasal mucosa. We also investigated how fluticasone propionate (FP), a corticosteroid used as an intranasal steroid spray, affects the gene expression.MethodsPrimary human nasal epithelial cells (HNECs) were collected from the nasal mucosa and incubated with Toll-like receptor (TLR) agonists and/or fluticasone propionate (FP), followed by quantitative PCR, immunofluorescence, and immunoblot analyses.ResultsAmong the TLR agonists, the TLR3 agonist Poly(I:C) significantly increased ACE2 and TMPRSS2 mRNA expression in HNECs (ACE2 36.212±11.600-fold change, p<0.0001; TMPRSS2 5.598±2.434-fold change, p=0.031). The ACE2 protein level was also increased with Poly(I:C) stimulation (2.884±0.505-fold change, p=0.003). The Poly(I:C)-induced ACE2 expression was suppressed by co-incubation with FP (0.405±0.312-fold change, p=0.044).ConclusionThe activation of innate immune signals via TLR3 promotes the expression of genes related to SARS-CoV2 cell entry in the nasal mucosa, although this expression is suppressed in the presence of FP. Further studies are required to evaluate whether FP suppresses SARS-CoV-2 viral cell entry.

scholarly journals Effect of Group A Streptococcal Cysteine Protease on Invasion of Epithelial Cells

1998 ◽  
Vol 66 (4) ◽  
pp. 1460-1466 ◽  
Author(s):  
Pei-Jane Tsai ◽  
Chih-Feng Kuo ◽  
Kuei-Yuan Lin ◽  
Yee-Shin Lin ◽  
Huan-Yao Lei ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cysteine Protease ◽  
Protease Activity ◽  
Extracellular Proteins ◽  
Wild Type ◽  
Respiratory Epithelial Cells ◽  
Group A ◽  
Human Respiratory Epithelial Cells ◽  
Respiratory Epithelial ◽  
Type Strains

ABSTRACT Cysteine protease of group A streptococci (GAS) is considered an important virulence factor. However, its role in invasiveness of GAS has not been investigated. We demonstrated in this study that two strains of protease-producing GAS had the ability to invade A-549 human respiratory epithelial cells. Isogenic protease mutants were constructed by using integrational plasmids to disrupt thespeB gene and confirmed by Southern hybridization and Western immunoblot analyses. No extracellular protease activity was produced by the mutants. The mutants had growth rates similar to those of the wild-type strains and produced normal levels of other extracellular proteins. When invading A-549 cells, the mutants had a two- to threefold decrease in activity compared to that of the wild-type strains. The invasion activity increased when the A-549 cells were incubated with purified cysteine protease and the mutant. However, blockage of the cysteine protease with a specific cysteine protease inhibitor, E-64, decreased the invasion activity of GAS. Intracellular growth of GAS was not found in A-549 cells. The presence or absence of protease activity did not affect the adhesive ability of GAS. These results suggested that streptococcal cysteine protease can enhance the invasion ability of GAS in human respiratory epithelial cells.

scholarly journals Infection of human Nasal Epithelial Cells with SARS-CoV-2 and a 382-nt deletion isolate lacking ORF8 reveals similar viral kinetics and host transcriptional profiles

2020 ◽  
Vol 16 (12) ◽  
pp. e1009130
Author(s):  
Akshamal M. Gamage ◽  
Kai Sen Tan ◽  
Wharton O. Y. Chan ◽  
Jing Liu ◽  
Chee Wah Tan ◽  
...  
Keyword(s):  
Immune Response ◽  
Epithelial Cells ◽  
Post Infection ◽  
Viral Gene ◽  
Suitable Model ◽  
Late Time ◽  
Wild Type ◽  
Nasal Epithelial Cells ◽  
Time Points ◽  
Infected Cells

The novel coronavirus SARS-CoV-2 is the causative agent of Coronavirus Disease 2019 (COVID-19), a global healthcare and economic catastrophe. Understanding of the host immune response to SARS-CoV-2 is still in its infancy. A 382-nt deletion strain lacking ORF8 (Δ382 herein) was isolated in Singapore in March 2020. Infection with Δ382 was associated with less severe disease in patients, compared to infection with wild-type SARS-CoV-2. Here, we established Nasal Epithelial cells (NECs) differentiated from healthy nasal-tissue derived stem cells as a suitable model for the ex-vivo study of SARS-CoV-2 mediated pathogenesis. Infection of NECs with either SARS-CoV-2 or Δ382 resulted in virus particles released exclusively from the apical side, with similar replication kinetics. Screening of a panel of 49 cytokines for basolateral secretion from infected NECs identified CXCL10 as the only cytokine significantly induced upon infection, at comparable levels in both wild-type and Δ382 infected cells. Transcriptome analysis revealed the temporal up-regulation of distinct gene subsets during infection, with anti-viral signaling pathways only detected at late time-points (72 hours post-infection, hpi). This immune response to SARS-CoV-2 was significantly attenuated when compared to infection with an influenza strain, H3N2, which elicited an inflammatory response within 8 hpi, and a greater magnitude of anti-viral gene up-regulation at late time-points. Remarkably, Δ382 induced a host transcriptional response nearly identical to that of wild-type SARS-CoV-2 at every post-infection time-point examined. In accordance with previous results, Δ382 infected cells showed an absence of transcripts mapping to ORF8, and conserved expression of other SARS-CoV-2 genes. Our findings shed light on the airway epithelial response to SARS-CoV-2 infection, and demonstrate a non-essential role for ORF8 in modulating host gene expression and cytokine production from infected cells.

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