The network pharmacology of the mechanism of the drug pair on the treatment of new Coronavirus pneumonia offending lung health syndrome

Objective: To explore the main pathways and possible mechanisms of Lonicera japonica-forsythia in the treatment of COVID-19 using network pharmacology.

Rapid visual detection of porcine reproductive and respiratory syndrome virus via recombinase polymerase amplification combined with a lateral flow dipstick.

Porcine reproductive and respiratory syndrome (PRRS) is one of the most economically devastating infectious diseases in the global swine industry. A rapid and sensitive on-site detection method for PRRS virus (PRRSV) is critically important for diagnosing PRRS. In this study, we established a method that combines reverse transcription recombinase polymerase amplification (RT-RPA) with a lateral flow dipstick (LFD) for detecting North American PRRSV (PRRSV-2). The primers and probe were designed based on the conserved region of all complete PRRSV-2 genomic sequences available in China (n = 512) from 1996 to 2020. The detection limit of the assay was 5.6 × 10-1 median tissue culture infection dose (TCID50) per reaction within 30 min at 42 °C, which was more sensitive than that of reverse transcription polymerase chain reaction (RT-PCR) (5.6 TCID50 per reaction). The assay was highly specific for the epidemic lineages of PRRSV-2 in China and did not cross-react with pseudorabies virus, porcine circovirus 2, classical swine fever virus, or porcine epidemic diarrhea virus. The assay performance was evaluated by testing 179 samples and comparing the results with those of quantitative RT-PCR (RT-qPCR). The results showed that the detection coincidence rate of RT-RPA and RT-qPCR was 100% when the cycle threshold values of RT-qPCR were < 32. The assay provides a new alternative for simple and reliable detection of PRRSV-2 and has great potential for application in the field.

Preclinical Evaluation and Pilot Clinical Study of Al18F-DX600-BCH for non-invasive PET Mapping of Angiotensin Converting Enzyme 2 in Mammal (preprint)

Angiotensin-converting enzyme 2 (ACE2), a transmembrane protein, is the main entry point for certain coronaviruses including the new coronavirus SARS-CoV-2 to enter cells. Synthesizing the PET imaging probe Al18F-DX600-BCH which is high-affinity ACE2 is aim to detect the expression of ACE2 in body and monitor the therapeutic effect. The Al18F-DX600-BCH was obtained manually with a 20.4% ± 5.2% radiochemical yield without attenuation correction and an over 99% purified radiochemical purity, being stable in vitro within 4 hours and cleared rapidly in blood (the half-lives of the distribution phase and clearance phase were 2.12 min and 25.31 min, respectively). Results of both biodistribution and PET imaging showed that Al18F-DX600-BCH was highly accumulated in the kidney (SUVkidney/normal > 50), and specific uptake in testis (SUVtestis/normal > 10) was observed in rat images. The kidney (++), gastrointestinal (++) and bronchial (+++) cells were evidenced of ACE2 positive by IHC staining of rats. A total of 10 volunteers were enrolled and received PET/CT 1 hour and 2 hours after injection or dynamic PET/CT during 0-330 seconds (NCT04542863), from which strong radioactivity accumulation was mostly observed in the genitourinary system (SUVrenal cortex = 32.00, SUVtestis = 4.56), and moderate accumulation in conjunctiva and nasal mucosa for several cases. This work firstly reported the probe Al18F-DX600-BCH targeting ACE2, conducting preliminary preclinical experiments and a total of 10 clinical transformations, which demonstrated the potential and possibility of non-invasive mapping of ACE2. Trial registration: ClinicalTrials.gov NCT04542863. Registered 9 September 2020.

The Home-School Linkage Instructional System and Its Development Suggestions Under the Perspective of Large-Scale Home-Based Learning

The learning ecosystem is the unified whole formed by education and its surrounding environment, including human elements such as the internal school education system and organization and non-human factors such as the external soft and challenging environment. However, the global COVID-19 outbreak in 2020 has led to large-scale home-based learning among students, which has broken the original ecological balance of learning. The interaction between the four elements of the traditional instructional system cannot explain all the teaching behavior. Based on the research perspective of large-scale home-based learning, this paper proposes to add family and technology into the original teaching system framework to form a new family-school linkage instructional System framework, including school education, family education, online teaching, and other types of education, improve the learning ecosystem and provide new thinking for the education and teaching in the post-epidemic era.

Retrospective Study of Clinical Features of COVID-19 in Inpatients and Their Association with Disease Severity.

BACKGROUND The aim of this study was to analyze the clinical features and laboratory indices of patients with coronavirus disease (COVID-19) and explore their association with the severity of the disease. MATERIAL AND METHODS A total of 61 patients with COVID-19 were divided into groups with common symptoms and with severe diseases, and clinical data were collected to analyze and compare the differences between them. RESULTS In patients with severe COVID-19, compared with the common group, lymphocyte count and albumin levels were lower, and aspartate aminotransferase (AST), blood urea, blood creatinine, lactate dehydrogenase (LDH), and C-reactive protein (CRP) levels, and prothrombin time (PT) were elevated (all P<0.05). The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), mean platelet volume-to-lymphocyte ratio (MPVLR), and C-reactive protein-to-albumin ratio (CAR) were significantly elevated in the severe group compared with the group with common symptoms; however, the lymphocyte-to-monocyte ratio (LMR) was significantly reduced (P<0.05). Univariate logistic regression showed that lower lymphocyte count, prolonged PT, elevated CRP and LDH levels, and elevated NLR, PLR, MPVLR, and CAR were risk factors for COVID-19 severity (P<0.05). Multivariate logistic regression showed that elevated CRP levels (odds ratio [OR], 0.028; 95% confidence interval [CI]: 0.002-0.526; P=0.017), prolonged PT (OR, 0.014; 95% CI: 0.001-0.341; P=0.09), and an MPVLR >8.9 (OR, 0.026; 95% CI: 0.002-0.349; P=0.006) were independent risk factors for COVID-19 severity. CONCLUSIONS Elevated CRP and prolonged PT, and an MPVLR >8.9 were independent risk factors for COVID-19 severity.

ORF3a mediated-incomplete autophagy facilitates SARS-CoV-2 replication (preprint)

SARS-CoV-2 is the causative agent for the COVID-19 pandemic and there is an urgent need to understand the cellular response to SARS-CoV-2 infection. Beclin-1 is an essential scaffold autophagy protein that forms two distinct subcomplexes with modulators Atg14 and UVRAG, responsible for autophagosome formation and maturation, respectively. In the present study, we found that SARS-CoV-2 infection triggers an incomplete autophagy response, elevated autophagosome formation but impaired autophagosome maturation, and declined autophagy by genetic knockout of essential autophagic genes reduces SARS-CoV-2 replication efficiency. By screening 28 viral proteins of SARS-CoV-2, we demonstrated that expression of ORF3a alone is sufficient to induce incomplete autophagy. Mechanistically, SARS-CoV-2 ORF3a interacts with autophagy regulator UVRAG to facilitate Beclin-1-Vps34-Atg14 complex but selectively inhibit Beclin-1-Vps34-UVRAG complex. Interestingly, although SARS-CoV ORF3a shares 72.7% amino acid identity with the SARS-CoV-2 ORF3a, the former had no effect on cellular autophagy response. Thus, our findings provide the mechanistic evidence of possible takeover of host autophagy machinery by ORF3a to facilitate SARS-CoV-2 replication and raises the possibility of targeting the autophagic pathway for the treatment of COVID-19.

ORF3a mediated-incomplete autophagy facilitates SARS-CoV-2 replication (preprint)

SARS-CoV-2 is the causative agent for the COVID-19 pandemic and there is an urgent need to understand the cellular response to SARS-CoV-2 infection. Beclin-1 is an essential scaffold autophagy protein that forms two distinct subcomplexes with modulators Atg14 and UVRAG, responsible for autophagosome formation and maturation, respectively. In the present study, we found that SARS-CoV-2 infection triggers an incomplete autophagy response, elevated autophagosome formation but impaired autophagosome maturation, and declined autophagy by genetic knockout of essential autophagic genes reduces SARS-CoV-2 replication efficiency. By screening 28 viral proteins of SARS-CoV-2, we demonstrated that expression of ORF3a alone is sufficient to induce incomplete autophagy. Mechanistically, SARS-CoV-2 ORF3a interacts with autophagy regulator UVRAG to facilitate Beclin-1-Vps34-Atg14 complex but selectively inhibit Beclin-1-Vps34-UVRAG complex. Interestingly, although SARS-CoV ORF3a shares 72.7% amino acid identity with the SARS-CoV-2 ORF3a, the former had no effect on cellular autophagy response. Thus, our findings provide the mechanistic evidence of possible takeover of host autophagy machinery by ORF3a to facilitate SARS-CoV-2 replication and raises the possibility of targeting the autophagic pathway for the treatment of COVID-19.

Virus-host interactome and proteomic survey of PMBCs from COVID-19 patients reveal potential virulence factors influencing SARS-CoV-2 pathogenesis (preprint)

The ongoing coronavirus disease (COVID-19) pandemic caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is a global public health concern due to relatively easy person-to-person transmission and the current lack of effective antiviral therapy. However, the exact molecular mechanisms of SARS-CoV-2 pathogenesis remain largely unknown. We exploited an integrated proteomics approach to systematically investigate intra-viral and virus-host interactomes for the identification of unrealized SARS-CoV-2 host targets and participation of cellular proteins in the response to viral infection using peripheral blood mononuclear cells (PBMCs) isolated from COVID-19 patients. Using this approach, we elucidated 251 host proteins targeted by SARS-CoV-2 and more than 200 host proteins that are significantly perturbed in COVID-19 derived PBMCs. From the interactome, we further identified that non-structural protein nsp9 and nsp10 interact with NKRF, a NF-[Kcy]B repressor, and may precipitate the strong IL-8/IL-6 mediated chemotaxis of neutrophils and overexuberant host inflammatory response observed in COVID-19 patients. Our integrative study not only presents a systematic examination of SARS-CoV-2-induced perturbation of host targets and cellular networks to reflect disease etiology, but also reveals insights into the mechanisms by which SARS-CoV-2 triggers cytokine storms and represents a powerful resource in the quest for therapeutic intervention.