Severe COVID-19 disease caused by SARS-CoV-2 is frequently accompanied by dysfunction of the lungs and extrapulmonary organs. However, the organotropism of SARS-CoV-2 and the port of virus entry for ...systemic dissemination remain largely unknown. We profiled 26 COVID-19 autopsy cases from four cohorts in Wuhan, China, and determined the systemic distribution of SARS-CoV-2. SARS-CoV-2 was detected in the lungs and multiple extrapulmonary organs of critically ill COVID-19 patients up to 67 days after symptom onset. Based on organotropism and pathological features of the patients, COVID-19 was divided into viral intrapulmonary and systemic subtypes. In patients with systemic viral distribution, SARS-CoV-2 was detected in monocytes, macrophages, and vascular endothelia at blood-air barrier, blood-testis barrier, and filtration barrier. Critically ill patients with long disease duration showed decreased pulmonary cell proliferation, reduced viral RNA, and marked fibrosis in the lungs. Permanent SARS-CoV-2 presence and tissue injuries in the lungs and extrapulmonary organs suggest direct viral invasion as a mechanism of pathogenicity in critically ill patients. SARS-CoV-2 may hijack monocytes, macrophages, and vascular endothelia at physiological barriers as the ports of entry for systemic dissemination. Our study thus delineates systemic pathological features of SARS-CoV-2 infection, which sheds light on the development of novel COVID-19 treatment.
Abstract In this study, a novel strategy is developed for the first time, referred to as high‐concentration cobalt ion‐assisted hydration (HCCAH) utilizing zeolitic imidazolate framework‐67 (ZIF‐67) ...as a precursor, to produce independent and flat α‐cobalt hydroxide nanosheets (CHN). These nanosheets offer abundant contact sites for binding with virus surface proteins. The formation of CHN involves the in situ transformation from ZIF‐67, due to the matching of the hydrolysis rate of ZIF‐67 and in situ growth rate of cobalt hydroxide orchestrated by high concentration of cobalt ions. Notably, the CHN contains a higher proportion of trivalent cobalt, which is shown to enhance the binding with the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS‐CoV‐2) Spike protein and induce protein structural denaturation, as demonstrated by molecular dynamics (MD) simulation. Antiviral experiments using pseudovirus and authentic viruses have confirmed the promising antiviral performance of CHN. Furthermore, both in vitro and in vivo experiments have demonstrated the excellent biocompatibility of CHN. This research opens up new possibilities for the application of cobalt hydroxide nanosheets and serves as a valuable reference for the design of antiviral nanomaterials.
Naturally abundant quinones are important molecules, which play essential roles in various biological processes due to their reduction potential. In contrast to their universality, the investigation ...of reactions between quinones and proteins remains sparse. Herein, we report the development of a convenient strategy to protein modification via a biomimetic quinone-mediated oxidation at the N-terminus. By exploiting unique reactivity of an ortho-quinone reagent, the α-amine of protein N-terminus is oxidized to generate aldo or keto handle for orthogonal conjugation. The applications have been demonstrated using a range of proteins, including myoglobin, ubiquitin and small ubiquitin-related modifier 2 (SUMO2). The effect of this method is further highlighted via the preparation of a series of 17 macrophage inflammatory protein 1β (MIP-1β) analogs, followed by preliminary anti-HIV activity and cell viability assays, respectively. This method offers an efficient and complementary approach to existing strategies for N-terminal modification of proteins.
Background and Purpose
The aim of this study was to investigate the ameliorative effects of corilagin on intrahepatic cholestasis induced by regulating liver farnesoid X receptor (FXR)‐associated ...pathways in vitro and in vivo.
Experimental Approach
Cellular and animal models were treated with different concentrations of corilagin. In the cellular experiments, FXR expression was up‐regulated by either lentiviral transduction or GW4064 treatment and down‐regulated by either siRNA technology or treatment with guggulsterones. Real‐time PCR and Western blotting were employed to detect the mRNA and protein levels of FXR, SHP1, SHP2, UGT2B4, BSEP, CYP7A1, CYP7B1, NTCP, MRP2 and SULT2A1. Immunohistochemistry was used to examine the expression of BSEP in liver tissues. Rat liver function and pathological changes in hepatic tissue were assessed using biochemical tests and haematoxylin and eosin staining.
Results
Corilagin increased the mRNA and protein levels of FXR, SHP1, SHP2, UGT2B4, BSEP, MRP2 and SULT2A1, and decreased those of CYP7A1, CYP7B1 and NTCP. After either up‐ or down‐regulating FXR using different methods, corilagin could still increase the mRNA and protein levels of FXR, SHP1, SHP2, UGT2B4, BSEP, MRP2 and SULT2A1 and decrease the protein levels of CYP7A1, CYP7B1 and NTCP, especially when administered at a high concentration. Corilagin also exerted a notable effect on the pathological manifestations of intrahepatic cholestasis, BSEP staining in liver tissues and liver function.
Conclusions and Implications
Corilagin exerts a protective effect in hepatocytes and can prevent the deleterious activities of intrahepatic cholestasis by stimulating FXR‐associated pathways.
The RNA‐dependent RNA polymerase (RdRp) is a crucial element in the replication and transcription of RNA viruses. Although the RdRps of lethal human coronaviruses severe acute respiratory syndrome ...coronavirus 2 (SARS‐CoV‐2), SARS‐CoV, and Middle East respiratory syndrome coronavirus (MERS‐CoV) have been extensively studied, the molecular mechanism of the catalytic subunit NSP12, which is involved in pathogenesis, remains unclear. In this study, the biochemical and cell biological results demonstrate the interactions between SARS‐CoV‐2 NSP12 and seven host proteins, including three splicing factors (SLU7, PPIL3, and AKAP8). The entry efficacy of SARS‐CoV‐2 considerably decreased when SLU7 or PPIL3 was knocked out, indicating that abnormal splicing of the host genome was responsible for this occurrence. Furthermore, the polymerase activity and stability of SARS‐CoV‐2 RdRp were affected by the three splicing factors to varying degrees. In addition, NSP12 and its homologues from SARS‐CoV and MERS‐CoV suppressed the alternative splicing of cellular genes, which were influenced by the three splicing factors. Overall, our research illustrates that SARS‐CoV‐2 NSP12 can engage with various splicing factors, thereby impacting virus entry, replication, and gene splicing. This not only improves our understanding of how viruses cause diseases but also lays the foundation for the development of antiviral therapies.
Great efforts have been made to expand the application fields of nanozymes, which puts forward requirements for nanozymes with both superior catalytic activity and specificity. Herein, we reported ...the high-indexed intermetallic Pt3Sn (H–Pt3Sn) with high peroxidase-like activity and specificity. The resultant H–Pt3Sn exhibits a specific activity of 345.3 U/mg, which is 1.82 times higher than Pt. Moreover, H–Pt3Sn possesses negligible oxidase-like and catalase-like activities, achieving superior catalytic specificity toward H2O2 activation. Experimental and theoretical calculations reveal both the splitting energy for adsorbed H2O2 and the energy barrier for the rate-determining step of H–Pt3Sn are significantly decreased compared with Pt3Sn and Pt. Finally, a nanozyme-linked immunosorbent assay is successfully developed, achieving the sensitive and accurate colorimetric detection for carcinoembryonic antigen with a low detection limit of 0.49 pg/mL and showing practical feasibility in serum sample detection.
Natural products possessing unique scaffolds may have antiviral activity but their complex structures hinder facile synthesis. A pharmacophore‐oriented semisynthesis approach was applied to ...(−)‐maoelactone A (1) and oridonin (2) for the discovery of anti‐SARS‐CoV‐2 agents. The Wolff rearrangement/lactonization cascade (WRLC) reaction was developed to construct the unprecedented maoelactone‐type scaffold during semisynthesis of 1. Further mechanistic study suggested a concerted mechanism for Wolff rearrangement and a water‐assisted stepwise process for lactonization. The WRLC reaction then enabled the creation of a novel family by assembly of the maoelactone‐type scaffold and the pharmacophore of 2, whereby one derivative inhibited SARS‐CoV‐2 replication in HPA EpiC cells with a low EC50 value (19±1 nM) and a high TI value (>1000), both values better than those of remdesivir.
A pharmacophore‐oriented semisynthesis (POSS) approach was applied to (−)‐maoelactone A (1) and oridonin (2) for the discovery of anti‐SARS‐CoV‐2 agents. A Wolff rearrangement/lactonization cascade (WRLC) was developed to install the unprecedented scaffold during semisynthesis of 1. Further assembly of the pharmacophore of 1 and scaffold of 2 by WRLC reaction led to the discovery of a potential anti‐SARS‐CoV‐2 agent with EC50 at 19 nM.
The selective interaction of nanomaterials with proteins for protein function suppression has been reported. However, whether the nanomaterials could be used to target a three-dimensional (3D) ...structure of proteins for the consequent function inhibition is not defined. When SARS-CoV-2 binds to the host cell surface ACE2 receptor, the spike protein trimer changes to an "Open State" which forms a 5 nm cavity structure, consequently exposing the receptor binding domain (RBD) for the following viral infection. We found that the 3 nm cerium oxide nanoparticles (CeO2@3) showed a better anti-SARS-CoV-2 effect than 30 nm cerium oxide nanoparticles (CeO2@30). We performed a series of experiments and demonstrated that the CeO2@3 could target the 5 nm spike protein trimer cavity and tightly bind with the RBD, thus effectively blocking the following virus-cell interaction and rendering CeO2@3 as an effective anti-viral agent. As all coronaviruses possess similar spike protein structures as homologous proteins, CeO2@3 can be used as a broad-sperm anti-coronavirus nanodrug candidate by targeting the spike protein 3D structure. This work, for the first time, demonstrated that rationally engineered inorganic nanomaterials can be used to specifically target a 3D structure of a certain protein for function inhibition, thus providing a novel methodological approach and paving the way for future molecular targeting nanodrug candidate design.
Display omitted
•Nanomaterials can be specifically used to target a 3D structure of a certain protein for function inhibition.•Nanomaterials have the strong and selective binding capacity to the target protein: here as CeO2@3 binding with RBD.•The tiny size of nanomaterials is appropriate to stuck a 3D structure thus block the subsequently function: here CeO2@3 is small enough to insert into the S1 trimer cavity.
Angiotensin-converting enzyme 2 (ACE2) is a major cell entry receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The induction of ACE2 expression may serve as a strategy by ...SARS-CoV-2 to facilitate its propagation. However, the regulatory mechanisms of ACE2 expression after viral infection remain largely unknown. Using 45 different luciferase reporters, the transcription factors SP1 and HNF4α were found to positively and negatively regulate ACE2 expression, respectively, at the transcriptional level in human lung epithelial cells (HPAEpiCs). SARS-CoV-2 infection increased the transcriptional activity of SP1 while inhibiting that of HNF4α. The PI3K/AKT signaling pathway, activated by SARS-CoV-2 infection, served as a crucial regulatory node, inducing ACE2 expression by enhancing SP1 phosphorylation-a marker of its activity-and reducing the nuclear localization of HNF4α. However, colchicine treatment inhibited the PI3K/AKT signaling pathway, thereby suppressing ACE2 expression. In Syrian hamsters (
) infected with SARS-CoV-2, inhibition of SP1 by either mithramycin A or colchicine resulted in reduced viral replication and tissue injury. In summary, our study uncovers a novel function of SP1 in the regulation of ACE2 expression and identifies SP1 as a potential target to reduce SARS-CoV-2 infection.
PDF
