A prospective study to evaluate the role of cholesterol metabolism related genes expression in predicting clinical outcome of patients with severe COVID-19

Background/Objectives: Latest studies have stressed the relevance of cholesterol metabolism with susceptibility to COVID-19 and its severity. We have previously shown downregulation of low-density lipoprotein particle receptor pathway in severe COVID-19 patient surviving compared to non-surviving(1). We aimed to assess the over-time expression changes of its relevant genes in severe COVID-19 patients with different outcomes (survivors/ non-survivors). Method(s): Blood samples were taken from 39 severe COVID-19 patients without chronic diseases twice: on the day of admission to the intensive care (T1) and in one week (T2). Within 30-day follow-up 18 patients recovered and 21 patients died. 20 individuals never previously infected with COVID-19 were also enrolled. Expression levels of studied genes in peripheral blood lymphocytes were analyzed by real-time PCR with TaqMan assay. Result(s): Increased expression of STAB1 at T2, PPARgamma at T1 and CD36 at T1 and T2 were revealed in COVID-19 patients regardless of the outcome compared to controls (p < 0.05). Interesting, that in respective groups of COVID-19 patients increased STAB1, decreased PPARgamma and in survivors decreased LRP6 expression were revealed at T2 compared to T1 (p < 0.01). Also, STAB1 expression was decreased in survivors compared to non-survivors at T2 (p=0.017). Conclusion(s): Our study revealed, that patients with severe COVID-19 are characterized by increased expression of cholesterol metabolism related genes, withmore pronounced decrease of expression of these genes over time for survivors. Increased STAB1 expression may be considered as a predictor of poor COVID-19 prognosis.

The CH24H metabolite, 24HC, blocks viral entry by disrupting intracellular cholesterol homeostasis.

Cholesterol-24-hydroxylase (CH24H or Cyp46a1) is a reticulum-associated membrane protein that plays an irreplaceable role in cholesterol metabolism in the brain and has been well-studied in several neuro-associated diseases in recent years. In the present study, we found that CH24H expression can be induced by several neuroinvasive viruses, including vesicular stomatitis virus (VSV), rabies virus (RABV), Semliki Forest virus (SFV) and murine hepatitis virus (MHV). The CH24H metabolite, 24-hydroxycholesterol (24HC), also shows competence in inhibiting the replication of multiple viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). 24HC can increase the cholesterol concentration in multivesicular body (MVB)/late endosome (LE) by disrupting the interaction between OSBP and VAPA, resulting in viral particles being trapped in MVB/LE, ultimately compromising VSV and RABV entry into host cells. These findings provide the first evidence that brain cholesterol oxidation products may play a critical role in viral infection.

25-Hydroxycholesterol Mediates Cholesterol Metabolism to Restrict Porcine Deltacoronavirus Infection via Suppression of Transforming Growth Factor ß1.

Porcine deltacoronavirus (PDCoV), an emerging enteropathogenic coronavirus in pigs, is one of the major pathogens for lethal watery diarrhea in piglets and poses a threat to public health because of its potential for interspecies transmission to humans. 25-Hydroxycholesterol (25HC), a derivative of cholesterol, exhibits multiple potential modulating host responses to pathogens, including viruses and bacteria, as well as pathogen-induced inflammation, while its antiviral effect on PDCoV and how it mediates the biological process of host cells to counter against infections remain poorly understood. Here, we thoroughly explored the antiviral effect of 25HC on PDCoV infection and tried to elucidate the underlying mechanisms. 25HC showed no toxic effect in LLC-PK1 cells and exerted antiviral ability against PDCoV infection in vitro. The viral cycle and time-of-addition analyses showed that 25HC mainly restricted the early and middle periods of the PDCoV postentry stage to inhibit infection. 25HC regulated disordered cholesterol metabolism induced by PDCoV infection and stimulated interferon-related lipid droplet accumulation. Transforming growth factor ß1 (TGF-ß1), screened by bioinformatic analyses, seemed to play an important role in PDCoV infection and was downregulated by 25HC. One interesting finding is that inhibition of TGF-ß1 with the inhibitor asiaticoside exhibited a similar antiviral capacity to 25HC and demonstrated regulation of cholesterol metabolism. Taking all of the findings together, we verified the antiviral effect of 25HC on PDCoV through interference with cholesterol metabolism, which may be related to its suppression of TGFß1. IMPORTANCE As an emerging enteropathogenic coronavirus in pigs, porcine deltacoronavirus (PDCoV) causes giant economic loss in the pig industry because of lethal diarrhea and possesses the potential for transmission from animals to humans. Several pieces of evidence have suggested the antiviral potential of cholesterol-25-hydroxylase and importance of cholesterol in viral infection. This study reports that 25-hydroxycholesterol (25HC) significantly restricted PDCoV infection through modulation of cholesterol metabolism, and we identified that lipid droplets play important roles in interferon response against virus infection. Moreover, this study identified the importance of TGF-ß1 in CoV infection by bioinformatic analysis and verified that the inhibition of TGF-ß1 showed anti-PDCoV capacity. Moreover, we uncovered the relationship between TGF-ß and cholesterol metabolism initially. Given that the importance of cholesterol in viral infection, 25HC has a great potential to treat PDCoV infection and TGF-ß1 can be a crucial antiviral target.

The constellation of cholesterol-dependent processes associated with SARS-CoV-2 infection.

The role of cholesterol in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other coronavirus-host cell interactions is currently being discussed in the context of two main scenarios: i) the presence of the neutral lipid in cholesterol-rich lipid domains involved in different steps of the viral infection and ii) the alteration of metabolic pathways by the virus over the course of infection. Cholesterol-enriched lipid domains have been reported to occur in the lipid envelope membrane of the virus, in the host-cell plasma membrane, as well as in endosomal and other intracellular membrane cellular compartments. These membrane subdomains, whose chemical and physical properties distinguish them from the bulk lipid bilayer, have been purported to participate in diverse phenomena, from virus-host cell fusion to intracellular trafficking and exit of the virions from the infected cell. SARS-CoV-2 recruits many key proteins that participate under physiological conditions in cholesterol and lipid metabolism in general. This review analyses the status of cholesterol and lipidome proteins in SARS-CoV-2 infection and the new horizons they open for therapeutic intervention.

Genomic variation underlies the severity of COVID19 clinical manifestation in individuals of European descent

Background: The coronavirus disease (COVID-19) caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is characterised by a wide spectrum of clinical phenotypes ranging in acuteness from asymptomatic, symptomatic with mild or moderate manifestation and severe involving pneumonia and respiratory distress. COVID-19 susceptibility, severity and recovery have demonstrated high variability worldwide. Variances in the host genetic architecture may potentially control the inter-individual and population scale differences in COVID-19 presentation. Methods: We performed a genome-wide association study (GWAS) employing the genotyping data from Ancestry DNA COVID-19 host genetic study that included COVID-19 positive patients and healthy individuals who had tested negative for SARS-CoV-2 infection at the time of recruitment. We restricted our analysis only to the individuals of European descents to avoid genetic structure in the dataset, arising due to the presence of people from different ancestries. Further, we uniquely employed the asymptomatic individuals as controls instead of healthy individuals. Results and Discussion: Our data revealed striking genomic differences between COVID-19 asymptomatic and severely symptomatic individuals. We identified 621 genetic variants that were significantly distinct (Multiple-testing corrected P<0.001) between asymptomatic and acutely symptomatic COVID-19 patients. These variants were found to be associated with pathways governing host immunity, such as innate and adaptive immune system, interferon signaling, interleukin signaling, antigen processing by MHC, cytokine signaling and known COVID-19 comorbidities, such as obesity, cholesterol metabolism and smoking. Variants modulating drug responses including to anti-retroviral agents were also found to vary significantly between asymptomatic and severe patient groups.

Proteomic Analysis Identifies Prolonged Disturbances in Pathways Related to Cholesterol Metabolism and Myocardium Function in the COVID-19 Recovery Stage.

The COVID-19 pandemic has become a worldwide health crisis. So far, most studies have focused on the epidemiology and pathogenesis of this infectious disease. Little attention has been given to the disease sequelae in patients recovering from COVID-19, and nothing is known about the mechanisms underlying these sequelae. Herein, we profiled the serum proteome of a cohort of COVID-19 patients in the disease onset and recovery stages. Based on the close integration of our proteomic analysis with clinical data, we propose that COVID-19 is associated with prolonged disorders in cholesterol metabolism and myocardium, even in the recovery stage. We identify potential biomarkers for these disorders. Moreover, severely affected patients presented more serious disturbances in these pathways. Our findings potentially support clinical decision-making to improve the prognosis and treatment of patients.