SARS-CoV-2 RBD and Its Variants Can Induce Platelet Activation and Clearance: Implications for Antibody Therapy and Vaccinations against COVID-19.

The COVID-19 pandemic caused by SARS-CoV-2 virus is an ongoing global health burden. Severe cases of COVID-19 and the rare cases of COVID-19 vaccine-induced-thrombotic-thrombocytopenia (VITT) are both associated with thrombosis and thrombocytopenia; however, the underlying mechanisms remain inadequately understood. Both infection and vaccination utilize the spike protein receptor-binding domain (RBD) of SARS-CoV-2. We found that intravenous injection of recombinant RBD caused significant platelet clearance in mice. Further investigation revealed the RBD could bind platelets, cause platelet activation, and potentiate platelet aggregation, which was exacerbated in the Delta and Kappa variants. The RBD-platelet interaction was partially dependent on the ß3 integrin as binding was significantly reduced in ß3-/- mice. Furthermore, RBD binding to human and mouse platelets was significantly reduced with related αIIbß3 antagonists and mutation of the RGD (arginine-glycine-aspartate) integrin binding motif to RGE (arginine-glycine-glutamate). We developed anti-RBD polyclonal and several monoclonal antibodies (mAbs) and identified 4F2 and 4H12 for their potent dual inhibition of RBD-induced platelet activation, aggregation, and clearance in vivo, and SARS-CoV-2 infection and replication in Vero E6 cells. Our data show that the RBD can bind platelets partially though αIIbß3 and induce platelet activation and clearance, which may contribute to thrombosis and thrombocytopenia observed in COVID-19 and VITT. Our newly developed mAbs 4F2 and 4H12 have potential not only for diagnosis of SARS-CoV-2 virus antigen but also importantly for therapy against COVID-19.

Myocardin Reverses Hypoxia-Inducible Factor-1α Mediated Phenotypic Modulation of Corpus Cavernosum Smooth Muscle Cells in Hypoxia Induced by Cobalt Chloride.

PURPOSE: We aimed to investigate the mechanism of phenotypic transformation of corporal cavernosum smooth muscle cells (CCSMCs) under hypoxic conditions in vitro. MATERIALS AND METHODS: In this study, a hypoxia model was established using cobalt chloride (CoCl2). CCSMCs were treated with different concentrations of CoCl2 for varying time periods, and cell viability was assessed. Hypoxia-inducible factor-1α (HIF-1α), myocardin (Myocd) and phenotypic markers were detected in the CCSMCs. We also transfected the CCSMCs with si-HIF-1α and Ad-Myocd and evaluated the effects on phenotypic modulation of CCSMCs and the relationship between HIF-1α and Myocd was evaluated. RESULTS: CoCl2 inhibited the viability of CCSMCs in a dose- and time-dependent manner, and treatment with 300 µM CoCl2 for 48 hours were the optimal conditions for establishing the hypoxia model. The results showed increased expression levels of HIF-1α and osteopontin and decreased Myocd, alpha-smooth muscle actin, and calponin levels in CCSMCs under hypoxia. HIF-1α knockdown reversed hypoxia-induced phenotypic transformation with elevated Myocd expression. Overexpression of Myocd also reversed the effect of hypoxia on the phenotypic switch, but did not affect HIF-1α expression. CONCLUSIONS: Our findings showed that HIF-1α was involved in the effect of hypoxia induced by CoCl2 on CCSMC phenotypic modulation, and Myocd overexpression could inhibit this process. Thus, Myocd might be a potential therapeutic target for erectile dysfunction under hypoxia or HIF-1α activation.

Key Role of Mesenchymal Stromal Cell Interaction with Macrophages in Promoting Repair of Lung Injury.

Lung macrophages (Mφs) are essential for pulmonary innate immunity and host defense due to their dynamic polarization and phenotype shifts. Mesenchymal stromal cells (MSCs) have secretory, immunomodulatory, and tissue-reparative properties and have shown promise in acute and chronic inflammatory lung diseases and in COVID-19. Many beneficial effects of MSCs are mediated through their interaction with resident alveolar and pulmonary interstitial Mφs. Bidirectional MSC-Mφ communication is achieved through direct contact, soluble factor secretion/activation, and organelle transfer. The lung microenvironment facilitates MSC secretion of factors that result in Mφ polarization towards an immunosuppressive M2-like phenotype for the restoration of tissue homeostasis. M2-like Mφ in turn can affect the MSC immune regulatory function in MSC engraftment and tissue reparatory effects. This review article highlights the mechanisms of crosstalk between MSCs and Mφs and the potential role of their interaction in lung repair in inflammatory lung diseases.

The Potential Protective Role of GS-441524, a Metabolite of the Prodrug Remdesivir, in Vaccine Breakthrough SARS-CoV-2 Infections.

Cases of vaccine breakthrough, especially in variants of concern (VOCs) infections, are emerging in coronavirus disease (COVID-19). Due to mutations of structural proteins (SPs) (e.g., Spike proteins), increased transmissibility and risk of escaping from vaccine-induced immunity have been reported amongst the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Remdesivir was the first to be granted emergency use authorization but showed little impact on survival in patients with severe COVID-19. Remdesivir is a prodrug of the nucleoside analogue GS-441524 which is converted into the active nucleotide triphosphate to disrupt viral genome of the conserved non-structural proteins (NSPs) and thus block viral replication. GS-441524 exerts a number of pharmacological advantages over Remdesivir: (1) it needs fewer conversions for bioactivation to nucleotide triphosphate; (2) it requires only nucleoside kinase, while Remdesivir requires several hepato-renal enzymes, for bioactivation; (3) it is a smaller molecule and has a potency for aerosol and oral administration; (4) it is less toxic allowing higher pulmonary concentrations; (5) it is easier to be synthesized. The current article will focus on the discussion of interactions between GS-441524 and NSPs of VOCs to suggest potential application of GS-441524 in breakthrough SARS-CoV-2 infections. Supplementary Information: The online version contains supplementary material available at 10.1007/s44231-022-00021-4.

Infection with the SARS-CoV-2 Omicron variant in children with congenital heart disease: A case series study during Shanghai epidemic.

Objective: To analyze the clinical characteristics and prognostic factors of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant infections in children with congenital heart disease (CHD). Methods: A retrospective analysis was performed on SARS-CoV-2 Omicron-infected children with CHD who were admitted to Shanghai Children's Medical Center from April 1, 2022 to May 31, 2022. The clinical, laboratory and imaging data, and the nucleic acid conversion time of the children in this group were collected and analyzed. Results: Thirteen patients were included in this study and had an average age of 1.1 (0.16-14) years. Among the patients, 3 patients were preoperatively treated, and 10 were postoperatively treated. According to the severity of the disease, 1 patient was diagnosed with the moderate type, and the remaining 12 patients were diagnosed with the mild type. The clinical symptoms were mostly associated with upper respiratory tract infections, including 13 with fever (100%), 8 with cough (61.8%), 5 with sputum production (38.5%), 1 of shortness of breath (7.7%), etc. All patients were successfully discharged from the hospital, with 16.4 ± 2.9 days needed to obtain cycle threshold (CT) values ≥35 in nucleic acid testing and 17.5 ± 3.6 days of hospitalization. Conclusions: For vulnerable patients such as children with CHD, SARS-CoV-2 Omicron variant infections mostly present with mild upper respiratory tract symptoms with negative or mildly changed chest imaging. Through appropriate treatment of the underlying disease in the quarantine ward, patients might obtain good outcomes, even after long periods of hospitalization.

Pharmacological therapies and drug development targeting SARS-CoV-2 infection.

The development of therapies for SARS-CoV-2 infection, based on virus biology and pathology, and of large- and small-scale randomized controlled trials, have brought forward several antiviral and immunomodulatory drugs targeting the disease severity. Casirivimab/Imdevimab monoclonal antibodies and convalescent plasma to prevent virus entry, Remdesivir, Molnupiravir, and Paxlovid nucleotide analogs to prevent viral replication, a variety of repurposed JAK-STAT signaling pathway inhibitors, corticosteroids, and recombinant agonists/antagonists of cytokine and interferons have been found to provide clinical benefits in terms of mortality and hospitalization. However, current treatment options face multiple clinical needs, and therefore, in this review, we provide an update on the challenges of the existing therapeutics and highlight drug development strategies for COVID-19 therapy, based on ongoing clinical trials, meta-analyses, and clinical case reports.

Genome-wide spatial expression profiling in formalin-fixed tissues.

Formalin-fixed paraffin embedding (FFPE) is the most widespread long-term tissue preservation approach. Here, we report a procedure to perform genome-wide spatial analysis of mRNA in FFPE-fixed tissue sections, using well-established, commercially available methods for imaging and spatial barcoding using slides spotted with barcoded oligo(dT) probes to capture the 3' end of mRNA molecules in tissue sections. We applied this method for expression profiling and cell type mapping in coronal sections from the mouse brain to demonstrate the method's capability to delineate anatomical regions from a molecular perspective. We also profiled the spatial composition of transcriptomic signatures in two ovarian carcinosarcoma samples, exemplifying the method's potential to elucidate molecular mechanisms in heterogeneous clinical samples. Finally, we demonstrate the applicability of the assay to characterize human lung and kidney organoids and a human lung biopsy specimen infected with SARS-CoV-2. We anticipate that genome-wide spatial gene expression profiling in FFPE biospecimens will be used for retrospective analysis of biobank samples, which will facilitate longitudinal studies of biological processes and biomarker discovery.

Basic Characteristics, Status, and Challenges of Integrative Oncology in China.

Integrative oncology has developed for about 20 years in some countries; however, integrative oncology is still a relative new term for most China's oncologists. Thus, it is essential to summarize the experience and expertise, share details of differing existing models and discuss future perspectives to help define and guide practice in integrative oncology in China. This study presents a summary of the basic characteristics, status, and challenges of integrative oncology in China, and also reports on China's integrative physicians' service delivery, clinical practice and research patterns of integrative oncology by an online national survey, including 405 oncologists. It is easy for cancer patients to access to integrative therapies in China. Public funding is sufficient for integrative oncology in China, and services are often provided through general hospitals and academic hospitals. Most (95.3%) of oncologists showed a positive attitude toward the development of integrative oncology. More than half (55.6%) of the oncologists worried about the influence on integrative oncology of COVID-19, especially for routine treatment, follow-up and holding seminars. We found that integrative oncology in China has swiftly developed in recent years. However, we suggest that standard diagnosis and treatment patterns and national professional guidelines should be set up as soon as possible.

JAK inhibition reduces SARS-CoV-2 liver infectivity and modulates inflammatory responses to reduce morbidity and mortality.

Using AI, we identified baricitinib as having antiviral and anticytokine efficacy. We now show a 71% (95% CI 0.15 to 0.58) mortality benefit in 83 patients with moderate-severe SARS-CoV-2 pneumonia with few drug-induced adverse events, including a large elderly cohort (median age, 81 years). An additional 48 cases with mild-moderate pneumonia recovered uneventfully. Using organotypic 3D cultures of primary human liver cells, we demonstrate that interferon-α2 increases ACE2 expression and SARS-CoV-2 infectivity in parenchymal cells by greater than fivefold. RNA-seq reveals gene response signatures associated with platelet activation, fully inhibited by baricitinib. Using viral load quantifications and superresolution microscopy, we found that baricitinib exerts activity rapidly through the inhibition of host proteins (numb-associated kinases), uniquely among antivirals. This reveals mechanistic actions of a Janus kinase-1/2 inhibitor targeting viral entry, replication, and the cytokine storm and is associated with beneficial outcomes including in severely ill elderly patients, data that incentivize further randomized controlled trials.

Emerging SARS-CoV-2 variants of concern and potential intervention approaches.

The major variant of concerns (VOCs) have shared mutations in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike proteins, mostly on the S1 unit and resulted in higher transmissibility rate and affect viral virulence and clinical outcome. The spike protein mutations and other non-structural protein mutations in the VOCs may lead to escape approved vaccinations in certain extend. We will discuss these VOC mutations and discuss the need for combination therapeutic strategies targeting viral cycle and immune host responses.

Association between use of Qingfei Paidu Tang and mortality in hospitalized patients with COVID-19: A national retrospective registry study.

BACKGROUND: Qingfei Paidu Tang (QPT), a formula of traditional Chinese medicine, which was suggested to be able to ease symptoms in patients with Coronavirus Disease 2019 (COVID-19), has been recommended by clinical guidelines and widely used to treat COVID-19 in China. However, whether it decreases mortality remains unknown. PURPOSE: We aimed to explore the association between QPT use and in-hospital mortality among patients hospitalized for COVID-19. STUDY DESIGN: A retrospective study based on a real-world database was conducted. METHODS: We identified patients consecutively hospitalized with COVID-19 in 15 hospitals from a national retrospective registry in China, from January through May 2020. Data on patients' characteristics, treatments, and outcomes were extracted from the electronic medical records. The association of QPT use with COVID-19 related mortality was evaluated using Cox proportional hazards models based on propensity score analysis. RESULTS: Of the 8939 patients included, 28.7% received QPT. The COVID-19 related mortality was 1.2% (95% confidence interval [CI] 0.8% to 1.7%) among the patients receiving QPT and 4.8% (95% CI 4.3% to 5.3%) among those not receiving QPT. After adjustment for patient characteristics and concomitant treatments, QPT use was associated with a relative reduction of 50% in-hospital COVID-19 related mortality (hazard ratio, 0.50; 95% CI, 0.37 to 0.66 p < 0.001). This association was consistent across subgroups by sex and age. Meanwhile, the incidences of acute liver injury (8.9% [95% CI, 7.8% to 10.1%] vs. 9.9% [95% CI, 9.2% to 10.7%]; odds ratio, 0.96 [95% CI, 0.81% to 1.14%], p = 0.658) and acute kidney injury (1.6% [95% CI, 1.2% to 2.2%] vs. 3.0% [95% CI, 2.6% to 3.5%]; odds ratio, 0.85 [95% CI, 0.62 to 1.17], p = 0.318) were comparable between patients receiving QPT and those not receiving QPT. The major study limitations included that the study was an observational study based on real-world data rather than a randomized control trial, and the quality of data could be affected by the accuracy and completeness of medical records. CONCLUSIONS: QPT was associated with a substantially lower risk of in-hospital mortality, without extra risk of acute liver injury or acute kidney injury among patients hospitalized with COVID-19.

Tai Chi for the elderly patients with COVID-19 in recovery period: A protocol for systematic review and meta-analysis.

BACKGROUND: The coronavirus disease 2019 (COVID-19) outbreak has caused a great impact in many countries. Older people are more susceptible to the virus than other people. As a good health exercise suitable for the elderly, Tai Chi has a positive impact on heart function, blood pressure, lung function, immunity, etc. It can enhance cardiopulmonary function, increase the elasticity of blood vessels, and improve the body's self-regulation function. For the elder patients with COVID-19, Tai Chi has outstanding merits. METHODS: We will search PubMed, EMBASE, MEDLINE, the Cochrane Library, Chinese National Knowledge Infrastructure, Chinese Biomedical Literature Database, Chinese Science and Technology Periodical Database, Wanfang Database, Clinical Trials and Chinese Clinical Trial Registry. The complete process will include study selection, data extraction, risk of bias assessment and meta-analyses. Endnote X9.3 will be used to manage data screening. The statistical analysis will be completed by Stata/SE 15.1 software. RESULTS: This proposed study will evaluate the effectiveness and safety of Tai Chi for the improvement of psychological pressure, cardiopulmonary function, and immunity in elderly COVID-19 patients during the recovery period. CONCLUSION: The conclusion of this study will provide evidence to prove the safety and effectiveness of Tai Chi on elderly COVID-19 patients during the recovery period. ETHICS AND DISSEMINATION: This protocol will not evaluate individual patient information or infringe patient rights and therefore does not require ethical approval. REGISTRATION: PEROSPERO CRD42020220128.

Human soluble ACE2 improves the effect of remdesivir in SARS-CoV-2 infection.

There is a critical need for safe and effective drugs for COVID-19. Only remdesivir has received authorization for COVID-19 and has been shown to improve outcomes but not decrease mortality. However, the dose of remdesivir is limited by hepatic and kidney toxicity. ACE2 is the critical cell surface receptor for SARS-CoV-2. Here, we investigated additive effect of combination therapy using remdesivir with recombinant soluble ACE2 (high/low dose) on Vero E6 and kidney organoids, targeting two different modalities of SARS-CoV-2 life cycle: cell entry via its receptor ACE2 and intracellular viral RNA replication. This combination treatment markedly improved their therapeutic windows against SARS-CoV-2 in both models. By using single amino-acid resolution screening in haploid ES cells, we report a singular critical pathway required for remdesivir toxicity, namely, Adenylate Kinase 2. The data provided here demonstrate that combining two therapeutic modalities with different targets, common strategy in HIV treatment, exhibit strong additive effects at sub-toxic concentrations. Our data lay the groundwork for the study of combinatorial regimens in future COVID-19 clinical trials.

Molecular mechanisms of sex bias differences in COVID-19 mortality.

More men than women have died from COVID-19. Genes encoded on X chromosomes, and sex hormones may explain the decreased fatality of COVID-19 in women. The angiotensin-converting enzyme 2 gene is located on X chromosomes. Men, with a single X chromosome, may lack the alternative mechanism for cellular protection after exposure to SARS-CoV-2. Some Toll-like receptors encoded on the X chromosomes can sense SARS-CoV-2 nucleic acids, leading to a stronger innate immunity response in women. Both estrogen and estrogen receptor-α contribute to T cell activation. Interventional approaches including estrogen-related compounds and androgen receptor antagonists may be considered in patients with COVID-19.

Hybrid Coordination for Coping with the Medical Surge from the COVID-19 Pandemic: Paired Assistance Programs in China.

The COVID-19 pandemic poses unprecedented challenges to public health care systems and demands intergovernmental coordination to cope with the resulting medical surge. This essay analyzes the operation of Paired Assistance Programs (PAPs) in China, offering a timely comparative case for researchers and practitioners to examine when reflecting on the classic debate over the hierarchical versus network approaches to coordination in emergency management. PAPs highlight the importance of network management and necessity of institutionalizing mechanisms of governance to facilitate coordination within multilevel response systems.

Inhibition of SARS-CoV-2 Infections in Engineered Human Tissues Using Clinical-Grade Soluble Human ACE2.

We have previously provided the first genetic evidence that angiotensin converting enzyme 2 (ACE2) is the critical receptor for severe acute respiratory syndrome coronavirus (SARS-CoV), and ACE2 protects the lung from injury, providing a molecular explanation for the severe lung failure and death due to SARS-CoV infections. ACE2 has now also been identified as a key receptor for SARS-CoV-2 infections, and it has been proposed that inhibiting this interaction might be used in treating patients with COVID-19. However, it is not known whether human recombinant soluble ACE2 (hrsACE2) blocks growth of SARS-CoV-2. Here, we show that clinical grade hrsACE2 reduced SARS-CoV-2 recovery from Vero cells by a factor of 1,000-5,000. An equivalent mouse rsACE2 had no effect. We also show that SARS-CoV-2 can directly infect engineered human blood vessel organoids and human kidney organoids, which can be inhibited by hrsACE2. These data demonstrate that hrsACE2 can significantly block early stages of SARS-CoV-2 infections.