Hyperglycemia-induced cathepsin L maturation: Implications for diabetic comorbidities and COVID-19 susceptibility (preprint)

Diabetes is the second most frequent chronic comorbidity for COVID-19 mortality, yet the underlying mechanism remains unclear. Previous studies suggest that Cathepsin L (CTSL) is implicated in diabetic complications such as nephropathy and retinopathy. Our previous research identified CTSL as a critical protease that promotes SARS-CoV-2 infection and a potential drug target. Here, we show that individuals with diabetes have elevated blood CTSL levels, which facilitates SARS-CoV-2 infection. Chronic hyperglycemia, as indicated by HbA1c levels, is positively correlated with CTSL concentration and activity in diabetic patients. Acute hyperglycemia induced by a hyperglycemic clamp in healthy individuals increases CTSL activity. In vitro, high glucose, but not high insulin, promotes SARS-CoV-2 infection in wild-type (WT) cells, while CTSL knockout (KO) cells show reduced susceptibility to high glucose-promoted effects. Using lung tissue samples from diabetic and non-diabetic patients, as well as db/db diabetic and control mice, our findings demonstrate that diabetic conditions increase CTSL activity in both humans and mice. Mechanistically, high glucose levels promote CTSL maturation and CTSL translocation from the endoplasmic reticulum (ER) to the lysosome via the ER-Golgi-lysosome axis. This study emphasizes the significance of hyperglycemia-induced cathepsin L maturation in the development of diabetic comorbidities and complications.

pH-Sensitive and Biodegradable Mn3(PO4)2·3H2O Nanoparticles as an Adjuvant of Protein-Based Bivalent COVID-19 Vaccine to Induce Potent and Broad-Spectrum Immunity.

Developing a novel and potent adjuvant with great biocompatibility for immune response augmentation is of great significance to enhance vaccine efficacy. In this work, we prepared a long-term stable, pH-sensitive, and biodegradable Mn3(PO4)2·3H2O nanoparticle (nano-MnP) by simply mixing MnCl2/NaH2PO4/Na2HPO4 solution for the first time and employed it as an immune stimulant in the bivalent COVID-19 protein vaccine comprised of wild-type S1 (S1-WT) and Omicron S1 (S1-Omicron) proteins as antigens to elicit a broad-spectrum immunity. The biological experiments indicated that the nano-MnP could effectively activate antigen-presenting cells through the cGAS-STING pathway. Compared with the conventional Alum-adjuvanted group, the nano-MnP-adjuvanted bivalent vaccine elicited approximately 7- and 8-fold increases in IgG antibody titers and antigen-specific IFN-γ secreting T cells, respectively. Importantly, antisera of the nano-MnP-adjuvanted group could effectively cross-neutralize the SARS-CoV-2 and its five variants of concern (VOCs) including Alpha, Beta, Gamma, Delta, and Omicron, demonstrating that this bivalent vaccine based on S1-WT and S1-Omicron proteins is an effective vaccine design strategy to induce broad-spectrum immune responses. Collectively, this nano-MnP material may provide a novel and efficient adjuvant platform for various prophylactic and therapeutic vaccines and provide insights for the development of the next-generation manganese adjuvant.

Affinity binding of COVID-19 drug candidates (chloroquine/hydroxychloroquine) and serum albumin: Based on photochemistry and molecular docking.

Chloroquine (CQ) and hydroxychloroquine (HCQ) show good efficacy in the treatment of SARS-CoV-2 in the early stage, while they are no longer recommended due to their side effects. As an important drug delivery carrier, serum albumin (SA) is closely related to the efficacy of drugs. Here, the affinity behaviour of chloroquine and hydroxychloroquine with two SA were investigated through the multispectral method of biochemistry and computer simulation. The results showed that the intrinsic emission of both SA was quenched by CQ and HCQ in a spontaneous exothermic entropy reduction static process, which relied mainly on hydrogen bonding and van der Waals forces. The lower binding constants suggested weak binding between the two drugs and SA, which might lead to differences in efficacy and possibly even to varying side effects. Binding site recognition demonstrated that CQ preferred to bind to the two sites of both SA, while HCQ tended to bind to site I of SA. The results of conformational studies demonstrated that CQ and HCQ could affect the structure of both SA by slightly increasing the α-helix content of SA. Finally, we combine the results from experimental start with molecular simulations to suggest drug modifications to guide the design of drugs. This work has important implications for guiding drug design improvements to select CQ derivatives with fewer side effects for the treatment of COVID-19.

[Clinical features of children and their family members with family clusters of SARS-CoV-2 Omicron variant infection in Shanghai, China: an analysis of 380 cases]. / 上海380例家庭聚集性感染Omicronå˜å¼‚æ ªçš„å„¿ç«¥åŠå ¶å®¶å±žä¸´åºŠç‰¹å¾åˆ†æž.

OBJECTIVES: To study the clinical features and prognosis of children and their family members with family clusters of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant infection under the admission mode of parent-child ward. METHODS: A retrospective analysis was performed on the medical data of 190 children and 190 family members with SARS-CoV-2 Omicron variant infection who were admitted to Shanghai Sixth People's Hospital, the designated hospital for coronavirus disease 2019 (COVID-19), April 8 to May 10, 2022. RESULTS: Both the child and adult groups were mainly mild COVID-19, and the proportion of mild cases in the child group was higher than that in the adult group (P<0.05). Respiratory symptoms were the main clinical manifestations in both groups. Compared with the adult group, the child group had higher incidence rates of fever, abdominal pain, diarrhea, and wheezing (P<0.05) and lower incidence rates of nasal obstruction, runny nose, cough, dry throat, throat itching, and throat pain (P<0.05). Compared with the child group, the adult group had higher rates of use of Chinese patent drugs, traditional Chinese medicine decoction, recombinant interferon spray, cough-relieving and phlegm-eliminating drugs, and nirmatrelvir/ritonavir tablets (P<0.05). Compared with the adult group, the child group had a lower vaccination rate of SARS-CoV-2 vaccine (30.5% vs 71.1%, P<0.001) and a shorter duration of positive SARS-CoV-2 nucleic acid (P<0.05). The patients with mild COVID-19 had a shorter duration of positive SARS-CoV-2 nucleic acid than those with common COVID-19 in both groups (P<0.05). The patients with underlying diseases had a longer duration of positive SARS-CoV-2 nucleic acid than those without such diseases in both groups (P<0.05). CONCLUSIONS: Both children and adults with family clusters of SARS-CoV-2 Omicron variant infection manifest mainly mild COVID-19. Despite lower vaccination rate of SARS-CoV-2 vaccine in children, they have rapid disease recovery, with a shorter duration of positive SARS-CoV-2 nucleic acid than adults, under the admission mode of parent-child ward.

Non-covalent cyclic peptides simultaneously targeting Mpro and NRP1 are highly effective against Omicron BA.2.75.

Available vaccine-based immunity may at high risk of being evaded due to substantial mutations in the variant Omicron. The main protease (Mpro) of SARS-CoV-2 and human neuropilin-1 (NRP1), two less mutable proteins, have been reported to be crucial for SARS-CoV-2 replication and entry into host cells, respectively. Their dual blockade may avoid vaccine failure caused by continuous mutations of the SARS-CoV-2 genome and exert synergistic antiviral efficacy. Herein, four cyclic peptides non-covalently targeting both Mpro and NRP1 were identified using virtual screening. Among them, MN-2 showed highly potent affinity to Mpro (K d = 18.2 ± 1.9 nM) and NRP1 (K d = 12.3 ± 1.2 nM), which was about 3,478-fold and 74-fold stronger than that of the positive inhibitors Peptide-21 and EG3287. Furthermore, MN-2 exhibited significant inhibitory activity against Mpro and remarkable anti-infective activity against the pseudotyped variant Omicron BA.2.75 without obvious cytotoxicity. These data demonstrated that MN-2, a novel non-covalent cyclic peptide, is a promising agent against Omicron BA.2.75.

Comparison of chest CT features between progressive and nonprogressive patients with COVID-19 pneumonia: A meta-analysis.

OBJECTIVE: The aim of this study was to compare the radiographic features of patients with progressive and nonprogressive coronavirus disease 2019 (COVID-19) pneumonia. METHODS: PubMed, Embase, and Cochrane Library databases were searched from January 1, 2020, to February 28, 2022, by using the keywords: "COVID-19", "novel Coronavirus", "2019-novel coronavirus", "CT", "radiology" and "imaging". We summarized the computed tomography manifestations of progressive and nonprogressive COVID-19 pneumonia. The meta-analysis was performed using the Stata statistical software version 16.0. RESULTS: A total of 10 studies with 1092 patients were included in this analysis. The findings of this meta-analysis indicated that the dominating computed tomography characteristics of progressive patients were a crazy-paving pattern (odds ratio [OR] = 2.10) and patchy shadowing (OR = 1.64). The dominating lesions distribution of progressive patients were bilateral (OR = 11.62), central mixed subpleural (OR = 1.37), and central (OR = 1.36). The other dominating lesions of progressive patients were pleura thickening (OR = 2.13), lymphadenopathy (OR = 1.74), vascular enlargement (OR = 1.39), air bronchogram (OR = 1.29), and pleural effusion (OR = 1.29). Two patterns of lesions showed significant links with the progression of disease: nodule (P = .001) and crazy-paving pattern (P = .023). Four lesions distribution showed significant links with the progression of disease: bilateral (P = .004), right upper lobe (P = .003), right middle lobe (P = .001), and left upper lobe (P = .018). CONCLUSION: Nodules, crazy-paving pattern, and/or new lesions in bilateral, upper and middle lobe of right lung, and lower lobe of left lung may indicate disease deterioration. Clinicians should formulate or modify treatment strategies in time according to these specific conditions.

Dual-targeting cyclic peptides of receptor-binding domain (RBD) and main protease (Mpro) as potential drug leads for the treatment of SARS-CoV-2 infection.

The receptor-binding domain (RBD) and the main protease (Mpro) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) play a crucial role in the entry and replication of viral particles, and co-targeting both of them could be an attractive approach for the treatment of SARS-CoV-2 infection by setting up a "double lock" in the viral lifecycle. However, few dual RBD/Mpro-targeting agents have been reported. Here, four novel RBD/Mpro dual-targeting peptides, termed as MRs 1-4, were discovered by an integrated virtual screening scheme combining molecular docking-based screening and molecular dynamics simulation. All of them possessed nanomolar binding affinities to both RBD and Mpro ranging from 14.4 to 39.2 nM and 22.5-40.4 nM, respectively. Further pseudovirus infection assay revealed that the four selected peptides showed >50% inhibition against SARS-CoV-2 pseudovirus at a concentration of 5 µM without significant cytotoxicity to host cells. This study leads to the identification of a class of dual RBD/Mpro-targeting agents, which may be developed as potential and effective SARS-CoV-2 therapeutics.

A qualitative comparative study of Japanese fashion brands via profiling young shoppers

Purpose This study adopts complexity theory to explore behavioural brand loyalty (BBL) development by investigating brand perceptional components and loyalty programs (LPs) in the Japanese fashion market through a qualitative comparative study. The authors address two research questions: (1) Under the potential influence of the COVID-19 pandemic, do brand perceptions and LPs contribute to young generation's BBL toward three types of brands with different scales of store numbers and prices? (2) If so, under what conditions do these factors positively influence BBL? Design/methodology/approach This study considers the effects of complex factors and conditions on BBL formation by testing the asymmetric relationships that exist among brand perceptions, LPs, and BBL via fuzzy-set qualitative comparative analysis (fsQCA). The authors surveyed 751 Japanese consumers (aged 18-25 years) who had chosen 26 Japanese fashion brands as their favourites and participated in the LPs of those brands. The use of fsQCA supplements the existing research by explaining how causal variables affect BBL both positively and negatively. Findings The results (1) present multiple causal solutions in predicting high BBL by profiling young shoppers based on their psychological and behavioural characteristics;(2) show how causal factors and consumer characteristics work differently when developing BBL for different types of brands. The findings established that brand perceptions and LPs could affect BBL positively and negatively, depending on the characteristics of fashion brands and shoppers. Originality/value This study offers theoretical and practical implications in two main aspects: (1) the authors adopted a mixed methodology with quantitative and qualitative analysis to propose an integrated model that connects perceptional brand loyalty and LPs with BBL, based on three types of Japanese fashion brands;(2) the results offer multiple solutions for predicting the high level of BBL by profiling shoppers' characteristics, considering the impacts of the COVID-19 pandemic.

The effects of COVID-19 on trade, production, environmental quality and its implications for green economy

Purpose>This study examines the effects of COVID-19 on trade, production and environmental quality and provides policy implications on green recovery.Design/methodology/approach>The two-step Heckman method is applied to estimate the structural gravity specification of trade. Besides, the two-step system GMM model is used to estimate the effects of COVID-19 on production and environmental quality. Additionally, descriptive analysis and literature review have been used.Findings>The findings disclose that COVID-19 adversely affected the trade performance of the countries. The results further imply that the regional trade agreements (RTAs) can play a key mediating role in the post-COVID-19 trade recovery. Besides, the impact of COVID-19 on the output is substantially negative. However, the effect of COVID-19 on environmental quality is significantly positive.Originality/value>It is the first study of its kind to examine the effects of COVID-19 on trade, production and CO2 emissions covering panel countries. Second, it provides a detailed analysis of firms planning to engage in the export sector. Moreover, it offers policy suggestions to consider environmental quality and green recovery. Besides, it examines the mediating role of RTAs in the relationship between trade and the pandemic.

How Health-Related Misinformation Spreads Across the Internet: Evidence for the "Typhoon Eye" Effect.

Online health-related misinformation has become a major problem in society and in-depth research is needed to understand its propagation patterns and underlying mechanisms. This study proposes a psychological typhoon eye effect to understand how health-related misinformation spreads during the pandemic using two national studies. In Study 1, we collected online search data from the United States and China to explore the relationship between the physical distance from the epicenter and the spread of health-related misinformation. Two common pieces of health-related misinformation were examined: "Microwaves kill coronavirus" in the United States and "Taking a hot bath can prevent against COVID-19" in China. Our results indicated a "typhoon eye effect" in the spread of two actual pieces of health-related misinformation using online data from the United States and China. In Study 2, we fabricated a piece of health-related misinformation, "Wash Clothes with Salt Water to Block Infection," and measured the spread behavior and perceived credibility of the misinformation. Again, we observed a typhoon eye effect on the spread behavior as well as the perceived credibility of health-related misinformation among people with limited education. In addition, based on the stimulus-organism-response theory, perceived credibility could serve as a mediator in the relationship between physical distance from the epicenter and the spread of health-related misinformation. Our results highlight the importance of psychological approaches to understanding the propagation patterns of health-related misinformation. The present findings provide a new perspective for development of prevention and control strategies to reduce the spread of health-related misinformation during pandemics.

Towards Efficient and Accurate SARS-CoV-2 Genome Sequence Typing Based on Supervised Learning Approaches.

Despite the active development of SARS-CoV-2 surveillance methods (e.g., Nextstrain, GISAID, Pangolin), the global emergence of various SARS-CoV-2 viral lineages that potentially cause antiviral and vaccine failure has driven the need for accurate and efficient SARS-CoV-2 genome sequence classifiers. This study presents an optimized method that accurately identifies the viral lineages of SARS-CoV-2 genome sequences using existing schemes. For Nextstrain and GISAID clades, a template matching-based method is proposed to quantify the differences between viral clades and to play an important role in classification evaluation. Furthermore, to improve the typing accuracy of SARS-CoV-2 genome sequences, an ensemble model that integrates a combination of machine learning-based methods (such as Random Forest and Catboost) with optimized weights is proposed for Nextstrain, Pangolin, and GISAID clades. Cross-validation is applied to optimize the parameters of the machine learning-based method and the weight settings of the ensemble model. To improve the efficiency of the model, in addition to the one-hot encoding method, we have proposed a nucleotide site mutation-based data structure that requires less computational resources and performs better in SARS-CoV-2 genome sequence typing. Based on an accumulated database of >1 million SARS-CoV-2 genome sequences, performance evaluations show that the proposed system has a typing accuracy of 99.879%, 97.732%, and 96.291% for Nextstrain, Pangolin, and GISAID clades, respectively. A single prediction only takes an average of <20 ms on a portable laptop. Overall, this study provides an efficient and accurate SARS-CoV-2 genome sequence typing system that benefits current and future surveillance of SARS-CoV-2 variants.

New-onset COVID-19-related diabetes: an early indicator of multi-organ injury and mortally of SARS-CoV-2 infection.

Objective: The pandemic of 2019 coronavirus (SARS-CoV-2) disease (COVID-19) has imposed a severe public health burden worldwide. Most patients with COVID-19 were mild. Severe patients progressed rapidly to critical condition including acute respiratory distress syndrome (ARDS), multi-organ failure and even death. This study aims to find early multi-organ injury indicators and blood glucose for predicting mortality of COVID-19. Methods: Fasting blood glucose (FBG) ≥7.0 mmol/L for two times during hospitalization and without a history of diabetes were defined as new-onset COVID-19-related diabetes (CRD). Indicators of injuries for multiple organs, including the lung, heart, kidney and liver, and glucose homeostasis were specifically analyzed for predicting death. Results: A total of 120 patients with a severity equal to or greater than Moderate were hospitalized. After excluding patients with history of diabetes, chronic heart, kidney, and liver disease, 69 patients were included in the final analysis. Of the 69 patients, 23 were Moderate, 20 were Severe, and 26 were Critical (including 16 deceased patients). Univariable analysis indicated that CRD, lactate dehydrogenase (LDH), hydroxybutyrate dehydrogenase (HBDH), creatine kinase (CK) and creatinine (Cr) were associated with death. Multivariable analysis indicated that CRD was an independent predictor for death (HR = 3.75, 95% CI 1.26-11.15). Abnormal glucose homeostasis or CRD occurred earlier than other indicators for predicting poor outcomes. Indicators of multiple organ injury were in parallel with the expression patterns of ACE2 (the SARS-CoV-2 receptor) in different organs including pancreatic islet. Conclusions: New-onset COVID-19-related diabetes is an early indicator of multi-organ injury and predictor for poor outcomes and death in COVID-19 patients. As it is easy to perform for clinical practices and self-monitoring, glucose testing will be helpful for predicting poor outcomes to facilitate appropriate intensive care.

Potential drug discovery for COVID-19 treatment targeting Cathepsin L using a deep learning-based strategy.

Cathepsin L (CTSL), a cysteine protease that can cleave and activate the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein, could be a promising therapeutic target for coronavirus disease 2019 (COVID-19). However, there is still no clinically available CTSL inhibitor that can be used. Here, we applied Chemprop, a newly trained directed-message passing deep neural network approach, to identify small molecules and FDA-approved drugs that can block CTSL activity to expand the discovery of CTSL inhibitors for drug development and repurposing for COVID-19. We found 5 molecules (Mg-132, Z-FA-FMK, leupeptin hemisulfate, Mg-101 and calpeptin) that were able to significantly inhibit the activity of CTSL in the nanomolar range and inhibit the infection of both pseudotype and live SARS-CoV-2. Notably, we discovered that daptomycin, an FDA-approved antibiotic, has a prominent CTSL inhibitory effect and can inhibit SARS-CoV-2 pseudovirus infection. Further, molecular docking calculation showed stable and robust binding of these compounds with CTSL. In conclusion, this study suggested for the first time that Chemprop is ideally suited to predict additional inhibitors of enzymes and revealed the noteworthy strategy for screening novel molecules and drugs for the treatment of COVID-19 and other diseases with unmet needs.

Novel cleavage sites identified in SARS-CoV-2 spike protein reveal mechanism for cathepsin L-facilitated viral infection and treatment strategies.

The spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an important target for vaccine and drug development. However, the rapid emergence of variant strains with mutated S proteins has rendered many treatments ineffective. Cleavage of the S protein by host proteases is essential for viral infection. Here, we discovered that the S protein contains two previously unidentified Cathepsin L (CTSL) cleavage sites (CS-1 and CS-2). Both sites are highly conserved among all known SARS-CoV-2 variants. Our structural studies revealed that CTSL cleavage promoted S to adopt receptor-binding domain (RBD) "up" activated conformations, facilitating receptor-binding and membrane fusion. We confirmed that CTSL cleavage is essential during infection of all emerged SARS-CoV-2 variants (including the recently emerged Omicron variant) by pseudovirus (PsV) infection experiment. Furthermore, we found CTSL-specific inhibitors not only blocked infection of PsV/live virus in cells but also reduced live virus infection of ex vivo lung tissues of both human donors and human ACE2-transgenic mice. Finally, we showed that two CTSL-specific inhibitors exhibited excellent In vivo effects to prevent live virus infection in human ACE2-transgenic mice. Our work demonstrated that inhibition of CTSL cleavage of SARS-CoV-2 S protein is a promising approach for the development of future mutation-resistant therapy.

The relationship between active coping and hope during the COVID-19 pandemic: The mediating role of meaning in life.

This study aims to examine the relationship between active coping and hope during the COVID-19 pandemic and investigate the underlying mechanism based on meaning making theory. We conducted a two-wave survey and recruited 521 Chinese adults (aged 18-65). Results show that all three active coping strategies (personal hygiene practice, support seeking, and positive reappraisal) at T1 was positively associated with T2 hope. Importantly, T2 meaning in life serves as a mediator between T1 active coping and T2 hope. Our findings suggest that active coping could be an effective approach to maintain mental health by making meaning and promoting hope.

Progress in Traditional Chinese Medicine Against Respiratory Viruses: A Review.

Respiratory viruses, such as severe acute respiratory syndrome coronavirus (SARS-CoV)-1, SARS-CoV-2, influenza A viruses, and respiratory syncytial virus, pose a serious threat to society. Based on the guiding principles of "holism" and "syndrome differentiation and treatment", traditional Chinese medicine (TCM) has unique advantages in the treatment of respiratory virus diseases owing to the synergistic effect of multiple components and targets, which prevents drug resistance from arising. According to TCM theory, there are two main strategies in antiviral treatments, namely "dispelling evil" and "fu zheng". Dispelling evil corresponds to the direct inhibition of virus growth and fu zheng corresponds to immune regulation, inflammation control, and tissue protection in the host. In this review, current progress in using TCMs against respiratory viruses is summarized according to modern biological theories. The prospects for developing TCMs against respiratory viruses is discussed to provide a reference for the research and development of innovative TCMs with multiple components, multiple targets, and low toxicity.

Novel sites for Cathepsin L cleavage in SARS-CoV-2 spike guide treatment strategies (preprint)

The spike (S) protein of SARS coronavirus 2 (SARS-CoV-2) is an ideal target for the development of specific vaccines or drugs. However, treatments targeting viruses with mutant S proteins that have recently emerged in many countries are limited. Cleavage of the S protein by host proteases is essential for viral infection. Here, we discovered two novel sites (CS-1 and CS-2) in the S protein for cleavage by the protease Cathepsin L (CTSL). Both sites are highly conserved among all SARS-CoV-2 variants of concern. Cryo-electron microscopy structural studies revealed that CTSL cleavage increases the dynamics of the receptor binding domain of S and induces novel conformations. In our pseudovirus (PsV) infection experiment, alteration of the cleavage site significantly reduced the infection efficiency, and CTSL inhibitors markedly inhibited infection with PsVs of both the wild-type and emerged SARS-CoV-2 variants. Furthermore, six highly efficient CTSL inhibitors were found to effectively inhibit live virus infection in human cells in vitro , and two of these were further confirmed to prevent live virus infection in human ACE2 transgenic mice in vivo . Our work suggested that the CTSL cleavage sites in SARS-CoV-2 S are emerging new but effective targets for the development of mutation-resistant vaccines and drugs.