Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 5 de 5
Filter
1.
Int J Biol Sci ; 18(12): 4744-4755, 2022.
Article in English | MEDLINE | ID: covidwho-1954694

ABSTRACT

Viruses exploit the host lipid metabolism machinery to achieve efficient replication. We herein characterize the lipids profile reprogramming in vitro and in vivo using liquid chromatography-mass spectrometry-based untargeted lipidomics. The lipidome of SARS-CoV-2-infected Caco-2 cells was markedly different from that of mock-infected samples, with most of the changes involving downregulation of ceramides. In COVID-19 patients' plasma samples, a total of 54 lipids belonging to 12 lipid classes that were significantly perturbed compared to non-infected control subjects' plasma samples were identified. Among these 12 lipid classes, ether-linked phosphatidylcholines, ether-linked phosphatidylethanolamines, phosphatidylcholines, and ceramides were the four most perturbed. Pathway analysis revealed that the glycerophospholipid, sphingolipid, and ether lipid metabolisms pathway were the most significantly perturbed host pathways. Phosphatidic acid phosphatases (PAP) were involved in all three pathways and PAP-1 deficiency significantly suppressed SARS-CoV-2 replication. siRNA knockdown of LPIN2 and LPIN3 resulted in significant reduction of SARS-CoV-2 load. In summary, these findings characterized the host lipidomic changes upon SARS-CoV-2 infection and identified PAP-1 as a potential target for intervention for COVID-19.


Subject(s)
COVID-19 , SARS-CoV-2 , Caco-2 Cells , Ceramides , Ethers , Glycerophospholipids , Humans , Lipid Metabolism , Phosphatidate Phosphatase/genetics , Phosphatidate Phosphatase/metabolism , Phosphatidylcholines/metabolism , Phosphatidylethanolamines/metabolism
2.
Journal of Clinical Microbiology ; 58(5), 2020.
Article in English | GIM | ID: covidwho-1723516

ABSTRACT

On 31 December 2019, the World Health Organization was informed of a cluster of cases of pneumonia of unknown etiology in Wuhan, China. Subsequent investigations identified a novel coronavirus, now named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), from the affected patients. Highly sensitive and specific laboratory diagnostics are important for controlling the rapidly evolving SARS-CoV-2-associated coronavirus disease 2019 (COVID-19) epidemic. In this study, we developed and compared the performance of three novel real-time reverse transcription-PCR (RT-PCR) assays targeting the RNA-dependent RNA polymerase (RdRp)/helicase (Hel), spike (S), and nucleocapsid (N) genes of SARS-CoV-2 with that of the reported RdRp-P2 assay, which is used in >30 European laboratories. Among the three novel assays, the COVID-19-RdRp/Hel assay had the lowest limit of detection in vitro (1.8 50% tissue culture infective doses [TCID50]/ml with genomic RNA and 11.2 RNA copies/reaction with in vitro RNA transcripts). Among 273 specimens from 15 patients with laboratory-confirmed COVID-19 in Hong Kong, 77 (28.2%) were positive by both the COVID-19-RdRp/Hel and RdRp-P2 assays. The COVID-19- RdRp/Hel assay was positive for an additional 42 RdRp-P2-negative specimens (119/273 [43.6%] versus 77/273 [28.2%];P 0.001), including 29/120 (24.2%) respiratory tract specimens and 13/153 (8.5%) non-respiratory tract specimens. The mean viral load of these specimens was 3.21 x 104 RNA copies/ml (range, 2.21 x 102 to 4.71 x 105 RNA copies/ml). The COVID-19-RdRp/Hel assay did not cross-react with other human-pathogenic coronaviruses and respiratory pathogens in cell culture and clinical specimens, whereas the RdRp-P2 assay cross-reacted with SARS-CoV in cell culture. The highly sensitive and specific COVID-19-RdRp/Hel assay may help to improve the laboratory diagnosis of COVID-19.

3.
Clin Infect Dis ; 2021 Sep 18.
Article in English | MEDLINE | ID: covidwho-1429186

ABSTRACT

BACKGROUND: The effect of low environmental temperature on viral shedding and disease severity of COVID-19 is uncertain. METHODS: We investigated the virological, clinical, pathological, and immunological changes in hamsters housed at room (21 oC), low (12-15 oC), and high (30-33 oC) temperature after challenge by 10 5 plaque-forming units of SARS-CoV-2. RESULTS: The nasal turbinate, trachea, and lung viral load and live virus titre were significantly higher (~0.5-log10 gene copies/ß-actin, p<0.05) in the low temperature group at 7 days post-infection (dpi). The low temperature group also demonstrated significantly higher level of TNF-α, IFN-γ, IL-1ß, and CCL3, and lower level of the antiviral IFN-α in lung tissues at 4dpi than the other two groups. Their lungs were grossly and diffusely haemorrhagic, with more severe and diffuse alveolar and peribronchiolar inflammatory infiltration, bronchial epithelial cell death, and significantly higher mean total lung histology scores. By 7dpi, the low temperature group still showed persistent and severe alveolar inflammation and haemorrhage, and little alveolar cell proliferative changes of recovery. The viral loads in the oral swabs of the low temperature group were significantly higher from 10-17dpi by about 0.5-1.0-log10 gene copies/ß-actin. The mean neutralizing antibody titre of the low temperature group was significantly (p<0.05) lower than that of the room temperature group at 7dpi and 30dpi. CONCLUSIONS: This study provided in-vivo evidence that low environmental temperature exacerbated the degree of virus shedding, disease severity, and tissue proinflammatory cytokines/chemokines expression, and suppressed the neutralizing antibody response of SARS-CoV-2-infected hamsters. Keeping warm in winter may reduce the severity of COVID-19.

5.
Int J Mol Sci ; 21(7)2020 Apr 08.
Article in English | MEDLINE | ID: covidwho-42099

ABSTRACT

The pandemic novel coronavirus infection, Coronavirus Disease 2019 (COVID-19), has affected at least 190 countries or territories, with 465,915 confirmed cases and 21,031 deaths. In a containment-based strategy, rapid, sensitive and specific testing is important in epidemiological control and clinical management. Using 96 SARS-CoV-2 and 104 non-SARS-CoV-2 coronavirus genomes and our in-house program, GolayMetaMiner, four specific regions longer than 50 nucleotides in the SARS-CoV-2 genome were identified. Primers were designed to target the longest and previously untargeted nsp2 region and optimized as a probe-free real-time reverse transcription-polymerase chain reaction (RT-PCR) assay. The new COVID-19-nsp2 assay had a limit of detection (LOD) of 1.8 TCID50/mL and did not amplify other human-pathogenic coronaviruses and respiratory viruses. Assay reproducibility in terms of cycle threshold (Cp) values was satisfactory, with the total imprecision (% CV) values well below 5%. Evaluation of the new assay using 59 clinical specimens from 14 confirmed cases showed 100% concordance with our previously developed COVID-19-RdRp/Hel reference assay. A rapid, sensitive, SARS-CoV-2-specific real-time RT-PCR assay, COVID-19-nsp2, was developed.


Subject(s)
Betacoronavirus/genetics , Clinical Laboratory Techniques/methods , Coronavirus Infections/diagnosis , Genome, Viral , Pneumonia, Viral/diagnosis , RNA, Viral/analysis , Real-Time Polymerase Chain Reaction , COVID-19 , COVID-19 Testing , COVID-19 Vaccines , Humans , Pandemics , Reproducibility of Results , Reverse Transcriptase Polymerase Chain Reaction , SARS-CoV-2 , Sensitivity and Specificity
SELECTION OF CITATIONS
SEARCH DETAIL