Targeting the Coronavirus Nucleocapsid Protein through GSK-3 Inhibition

A mitochondrial surveillance mechanism activated by SRSF2 mutations in hematologic malignancies

Splicing factor mutations are common in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML), but how they alter cellular functions is unclear. We show that the pathogenic SRSF2P95H/+ mutation disrupts the splicing of mitochondrial mRNAs, impairs mitochondrial complex I function, and robustly increases mitophagy. We also identified a mitochondrial surveillance mechanism by which mitochondrial dysfunction modifies splicing of the mitophagy activator PINK1 to remove a poison intron, increasing the stability and abundance of PINK1 mRNA and protein. SRSF2P95H-induced mitochondrial dysfunction increased PINK1 expression through this mechanism, which is essential for survival of SRSF2P95H/+ cells. Inhibition of splicing with a glycogen synthase kinase 3 inhibitor promoted retention of the poison intron, impairing mitophagy and activating apoptosis in SRSF2P95H/+ cells. These data reveal a homeostatic mechanism for sensing mitochondrial stress through PINK1 splicing and identify increased mitophagy as a disease marker and a therapeutic vulnerability in SRSF2P95H mutant MDS and AML.

The SARS-CoV-2 nucleocapsid protein: its role in the viral life cycle, structure and functions, and use as a potential target in the development of vaccines and diagnostics

Coronavirus disease 2019 (COVID-19) continues to take a heavy toll on personal health, healthcare systems, and economies around the globe. Scientists are expending tremendous effort to develop diagnostic technologies for detecting positive infections within the shortest possible time, and vaccines and drugs specifically for the prevention and treatment of COVID-19 disease. At the same time, emerging novel variants have raised serious concerns about vaccine efficacy. The SARS-CoV-2 nucleocapsid (N) protein plays an important role in the coronavirus life cycle, and participates in various vital activities after virus invasion. It has attracted a large amount of attention for vaccine and drug development. Here, we summarize the latest research of the N protein, including its role in the SARS-CoV-2 life cycle, structure and function, and post-translational modifications in addition to its involvement in liquid-liquid phase separation (LLPS) and use as a basis for the development of vaccines and diagnostic techniques.

Psychotropic drug repurposing for COVID-19: A Systematic Review and Meta-Analysis

Several psychotropic drugs, including antidepressants (AD), mood stabilizers, and antipsychotics (AP) have been suggested to have favorable effects in the treatment of COVID-19. The aim of this systematic review and meta-analysis was to collect evidence from studies concerning the scientific evidence for the repurposing of psychotropic drugs in COVID-19 treatment. Two independent authors searched PubMed-MEDLINE, Scopus, PsycINFO, and ClinicalTrials.gov databases, and reviewed the reference lists of articles for eligible articles published up to 13th December 2021. All computational, preclinical and clinical (observational and/or RCTs) studies on the effect of any psychotropic drug on Sars-CoV-2 or patients with COVID-19 were considered for inclusion. We conducted random effect meta-analyses on clinical studies reporting the effect of AD or AP on COVID-19 outcomes. 29 studies were included in the synthesis: 15 clinical, 9 preclinical, and 5 computational studies. 9 clinical studies could be included in the quantitative analyses. AD did not increase the risk of severe COVID-19 (RR= 1.71; CI 0.65-4.51) or mortality (RR=0.94; CI 0.81-1.09). Fluvoxamine was associated with a reduced risk of mortality for COVID-19 (OR=0.15; CI 0.02-0.95). AP increased the risk of severe COVID-19 (RR=3.66; CI 2.76-4.85) and mortality (OR=1.53; CI 1.15-2.03). Fluvoxamine might be a possible candidate for psychotropic drug repurposing in COVID-19 due to its anti-inflammatory and antiviral potential, while evidence on other AD is still controversial. Although AP are associated with worse COVID-19 outcomes, their use should be evaluated case to case and ongoing treatment with antipsychotics should be not discontinued in psychiatric patients.

Molecular mechanisms and therapeutic effects of different vitamins and minerals in COVID-19 patients

COVID-19 is a rapidly spreading disease, which has caught the world by surprise. Millions of people suffer from illness, and the mortality rates are dramatically high. Currently, there is no specific and immediate treatment for this disease. Remedies are limited to supportive regiments and few antiviral and anti-inflammatory drugs. The lack of a definite cure for COVID-19 is the reason behind its high mortality and global prevalence. COVID-19 can lead to a critical illness with severe respiratory distress and cytokine release. Increased oxidative stress and excessive production of inflammatory cytokines are vital components of severe COVID-19. Micronutrients, metalloids, and vitamins such as iron, manganese, selenium, Zinc, Copper, vitamin A, B family, and C are among the essential and trace elements that play a pivotal role in human nutrition and health. They participate in metabolic processes that lead to energy production. In addition, they support immune functions and act as antioxidants. Therefore, maintaining an optimal level of micronutrients intake, particularly those with antioxidant activities, is essential to fight against oxidative stress, modulate inflammation, and boost the immune system. Therefore, these factors could play a crucial role in COVID-19 prevention and treatment. In this review, we aimed to summarize antiviral properties of different vitamins and minerals. Moreover, we will investigate the correlation between them and their effects in COVID-19 patients.

SARS-CoV-2 Nucleocapsid Protein Targets a Conserved Surface Groove of the NTF2-like Domain of G3BP1

Stress granule (SG) formation mediated by Ras GTPase-activating protein-binding protein 1 (G3BP1) constitutes a key obstacle for viral replication, which makes G3BP1 a frequent target for viruses. For instance, the SARS-CoV-2 nucleocapsid (N) protein interacts with G3BP1 directly to suppress SG assembly and promote viral production. However, the molecular basis for the SARS-CoV-2 N - G3BP1 interaction remains elusive. Here we report biochemical and structural analyses of the SARS-CoV-2 N - G3BP1 interaction, revealing differential contributions of various regions of SARS-CoV-2 N to G3BP1 binding. The crystal structure of the NTF2-like domain of G3BP1 (G3BP1_NTF2) in complex with a peptide derived from SARS-CoV-2 N (residues 1-25, N_1-25) reveals that SARS-CoV-2 N_1-25 occupies a conserved surface groove of G3BP1_NTF2 via surface complementarity. We show that a φ-x-F (φ, hydrophobic residue) motif constitutes the primary determinant for G3BP1_NTF2-targeting proteins, while the flanking sequence underpins diverse secondary interactions. We demonstrate that mutation of key interaction residues of the SARS-CoV-2 N_1-25 - G3BP1_NTF2 complex leads to disruption of the SARS-CoV-2 N - G3BP1 interaction in vitro. Together, these results provide a molecular basis of the strain-specific interaction between SARS-CoV-2 N and G3BP1, which has important implications for the development of novel therapeutic strategies against SARS-CoV-2 infection.

Knowledge Graph-Based Approaches to Drug Repurposing for COVID-19

The COVID-19 pandemic has motivated researchers all over the world in trying to find effective drugs and therapeutics for treating this disease. To save time, much effort has focused on repurposing drugs known for treating other diseases than COVID-19. To support these drug repurposing efforts, we built the CAS Biomedical Knowledge Graph and identified 1350 small molecules as potentially repurposable drugs that target host proteins and disease processes involved in COVID-19. A computer algorithm-driven drug-ranking method was developed to prioritize those identified small molecules. The top 50 molecules were analyzed according to their molecular functions and included 11 drugs in clinical trials for treating COVID-19 and new candidates that may be of interest for clinical investigation. The CAS Biomedical Knowledge Graph provides researchers an opportunity to accelerate innovation and streamline the investigative process not just for COVID-19 but also in many other diseases.