The hypothetical role of phosphatidic acid in subverting ER membranes during SARS-CoV infection

Metabolic alterations upon SARS-CoV-2 infection and potential therapeutic targets against coronavirus infection

The coronavirus disease 2019 (COVID-19) caused by coronavirus SARS-CoV-2 infection has become a global pandemic due to the high viral transmissibility and pathogenesis, bringing enormous burden to our society. Most patients infected by SARS-CoV-2 are asymptomatic or have mild symptoms. Although only a small proportion of patients progressed to severe COVID-19 with symptoms including acute respiratory distress syndrome (ARDS), disseminated coagulopathy, and cardiovascular disorders, severe COVID-19 is accompanied by high mortality rates with near 7 million deaths. Nowadays, effective therapeutic patterns for severe COVID-19 are still lacking. It has been extensively reported that host metabolism plays essential roles in various physiological processes during virus infection. Many viruses manipulate host metabolism to avoid immunity, facilitate their own replication, or to initiate pathological response. Targeting the interaction between SARS-CoV-2 and host metabolism holds promise for developing therapeutic strategies. In this review, we summarize and discuss recent studies dedicated to uncovering the role of host metabolism during the life cycle of SARS-CoV-2 in aspects of entry, replication, assembly, and pathogenesis with an emphasis on glucose metabolism and lipid metabolism. Microbiota and long COVID-19 are also discussed. Ultimately, we recapitulate metabolism-modulating drugs repurposed for COVID-19 including statins, ASM inhibitors, NSAIDs, Montelukast, omega-3 fatty acids, 2-DG, and metformin.

Untargeted LC-MS based metabolomic profiling of iPAMs to investigate lipid metabolic pathways alternations induced by different Pseudorabies virus strains

Owing to viral recombination, interspecies transmission, and evolution, variant pseudorabies virus (PRV) strains exhibit different biological characteristics and pathogenicity. To improve the understanding of common and specific metabolic changes that occur upon infection by different PRV strains, we herein describe the comprehensive analysis of metabolites of PRV vaccine strain (Bartha K61), classical strain (EA) and variant strain (HNX) infection in immortalized porcine alveolar macrophage cells. Compared with uninfected cells, cells infected with Bartha K61, EA and HNX had 246, 225, and 272 differing metabolites, respectively. In the three types of PRV-strain-infected cells, lipids and lipid-like molecules accounted for over 50 % of the altered metabolites. As these viruses are enveloped, viral replication, assembly and release occur on cellular membranes primed through the manipulation of the host metabolism. We analyzed the potential relationship between virus replication and the virus-mediated host metabolism. Our study resulted in the first reconstruction of the major lipid metabolic pathways involved in PRV infection, including those of glycerophospholipids, sphingolipids, glycerolipids, and fatty acyls. In addition, the metabolic perturbations caused by different PRV strain infections are consistent across many species, however, our results also revealed many specific metabolic alterations during HNX infection, such as the enrichment of phosphatidylinositol and 15R-PGE2 methyl ester 15-acetate, and the diminishment of phosphatidylethanolamine, phosphatidic acid, and ceramides. These strain-specific altered metabolites may be linked to the unique biological characteristics and pathogenicity of the HNX strain.

Dissecting lipid metabolism alterations in SARS-CoV-2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of the COVID-19 pandemic that has infected over a hundred million people globally. There have been more than two million deaths recorded worldwide, with no end in sight until a widespread vaccination will be achieved. Current research has centred on different aspects of the virus interaction with cell surface receptors, but more needs to be done to further understand its mechanism of action in order to develop a targeted therapy and a method to control the spread of the virus. Lipids play a crucial role throughout the viral life cycle, and viruses are known to exploit lipid signalling and synthesis to affect host cell lipidome. Emerging studies using untargeted metabolomic and lipidomic approaches are providing new insight into the host response to COVID-19 infection. Indeed, metabolomic and lipidomic approaches have identified numerous circulating lipids that directly correlate to the severity of the disease, making lipid metabolism a potential therapeutic target. Circulating lipids play a key function in the pathogenesis of the virus and exert an inflammatory response. A better knowledge of lipid metabolism in the host-pathogen interaction will provide valuable insights into viral pathogenesis and to the development of novel therapeutic targets.

Various Facets of Pathogenic Lipids in Infectious Diseases: Exploring Virulent Lipid-Host Interactome and Their Druggability

Lipids form an integral, structural, and functional part of all life forms. They play a significant role in various cellular processes such as membrane fusion, fission, endocytosis, protein trafficking, and protein functions. Interestingly, recent studies have revealed their more impactful and critical involvement in infectious diseases, starting with the manipulation of the host membrane to facilitate pathogenic entry. Thereafter, pathogens recruit specific host lipids for the maintenance of favorable intracellular niche to augment their survival and proliferation. In this review, we showcase the lipid-mediated host pathogen interplay in context of life-threatening viral and bacterial diseases including the recent SARS-CoV-2 infection. We evaluate the emergent lipid-centric approaches adopted by these pathogens, while delineating the alterations in the composition and organization of the cell membrane within the host, as well as the pathogen. Lastly, crucial nexus points in their interaction landscape for therapeutic interventions are identified. Lipids act as critical determinants of bacterial and viral pathogenesis by altering the host cell membrane structure and functions.

On the potential role of exosomes in the COVID-19 reinfection/reactivation opportunity

We propose here that one of the potential mechanisms for the relapse of the COVID-19 infection could be a cellular transport pathway associated with the release of the SARS-CoV-2-loaded exosomes and other extracellular vesicles. It is possible that this “Trojan horse” strategy represents possible explanation for the re-appearance of the viral RNA in the recovered COVID-19 patients 7–14 day post discharge, suggesting that viral material was hidden within such exosomes or extracellular vesicles during this “silence” time period and then started to re-spread again.

Communicated by Ramaswamy H. Sarma