GP73 is a glucogenic hormone that contributes to SARS-CoV-2-induced hyperglycemia (preprint)

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection induces new-onset diabetes and severe metabolic complications of pre-existing diabetes. The pathogenic mechanism underlying this is incompletely understood. Here, we provided evidence linking circulating GP73 with the exaggerated gluconeogenesis triggered by SARS-CoV-2 infection. We found that SARS-CoV-2 infection or glucotoxic conditions increased GP73 production and secretion. Secreted GP73 then trafficked to the liver and kidney to stimulate gluconeogenesis through the cAMP/PKA pathway. By using global phosphoproteomics, we found a drastic remodeling of the PKA kinase hub exerted by GP73. Notably, plasma GP73 levels were elevated and positively correlated with blood glucose in patients with COVID19 and diabetes. Neutralization of circulating GP73 in serum of individuals infected with SARS-CoV-2 or with diabetes reduced excessive gluconeogenesis in cultured hepatocytes, and lowered blood glucose levels in animal models of diabetes. Ablation of GP73 from whole animals has a profound glucose-lowering effect secondary to reduced gluconeogenesis. Thus, GP73 is a key glucogenic hormone contributing to SARS-CoV-2-induced glucose abnormality.

GP73 is a glucogenic hormone regulating SARS-CoV-2-induced hyperglycemia (preprint)

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection induces new-onset diabetes and severe metabolic complications of pre-existing diabetes. The pathogenic mechanism underlying this is incompletely understood. Here, we provided evidence linking circulating GP73 with the exaggerated gluconeogenesis triggered by SARS-CoV-2 infection. We found that SARS-CoV-2 infection or glucotoxic condition increased the cellular secretion of GP73. Secreted GP73 trafficked to the liver and kidney to stimulate gluconeogenesis through cAMP/PKA pathway. By using global phosphoproteomics, we found a drastic remodeling of PKA kinase hub exerted by GP73. Notably, COVID-19 patients showed pathologically elevated plasma GP73, and neutralization of the secreted GP73 inhibited enhanced PKA signaling and glucose production associated with SARS-CoV-2 infection. GP73 blockade also reduced gluconeogenesis and lowered hyperglycemia in type 2 (T2D) diabetic mice. Therefore, our findings provide novel insight into the roles of GP73 as a key glucogenic hormone and mechanistic clues underlying the development of SARS-CoV-induced glucose abnormalities.

SARS-CoV-2 manipulates the SR-B1-mediated HDL uptake pathway for its entry (preprint)

The recently emerged pathogenic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread rapidly, leading to a global COVID-19 pandemic. Binding of the viral spike protein (SARS-2-S) to cell surface receptor angiotensin-converting enzyme 2 (ACE2) mediates host cell infection. In the present study, we demonstrate that in addition to ACE2, the S1 subunit of SARS-2-S binds to HDL and that SARS-CoV-2 hijacks the SR-B1-mediated HDL uptake pathway to facilitate its entry. SR-B1 facilitates SARS-CoV-2 entry into permissive cells by augmenting virus attachment. MAb (monoclonal antibody)-mediated blocking of SARS-2-S-HDL binding and SR-B1 antagonists strongly inhibit HDL-enhanced SARS-CoV-2 infection. Notably, SR-B1 is co-expressed with ACE2 in human pulmonary and extrapulmonary tissues. These findings revealed a novel mechanism for SARS-CoV-2 entry and could provide a new target to treat SARS-CoV-2 infection.

Risk Factors Related to Weight Gain for Chines During Home Confinement in COVID-19 Pandemic: An Observational Retrospective Study (preprint)

Objective: The observational study was intended to explore the weight changes and risk factors of weight gain during the self-quarantine and find available methods to lose weight. Method: This was an online retrospective observational study investigating the weight changes before and after home confinement. A total of 530 participants completed the online questionnaire. diet, sleep, self-reported depression, disease history and exercise information possibly relating to weight changes were incorporated into the questionnaire. The differences among four groups (underweight, normal weight, overweight and obesity) in BMI change and weight change were compared, and the risk factors of weight gain was also analyzed by multiple linear regression analysis. Result: Participants were mostly between 21-50 years old, getting an average weight change of 0.82±3.31kg, and an average BMI change of 0.35 [-0.37, 1.00]. 43.77% of them gained weight by 2.99±2.29kg averagely. People with normal weight were easier to gain weight than obese group (p=0.001). There were differences in food intake (p<0.001), eating habits(p<0.001), taste preference (p=0.047), daily exercise step change(p=0.007), exercise (p=0.02) between non-weight gain group and weight gain group. The multiple linear regression revealed that weight gains were associated with sex (p=0.002), food intake (p=0.004), current daily exercise step (p=0.009) and self-reported depression (p=0.002) and weight loss was related to food intake (p=0.004) and pre-BMI (p=0.001). Conclusion: Eating irregularly, increasing food intake, self-reported depression and decreased daily steps were risk factors of weight gain, yet weight loss was related to decreased food intake and pre-BMI.

Clinical Efficacy of Ribavirin in Adults Hospitalized With Severe Covid-19: A Retrospective Analysis of 208 Patients (preprint)

Background: Coronavirus disease-2019 (COVID-19) spreads rapidly throughout the world. So far, no therapeutics have yet been proven to be effective. Ribavirin was recommended for the treatment of COVID-19 because of its in vitro activity. However, evidence supporting its clinical use with good efficacy is still lacking.Methods: A total of 208 confirmed severe or critical COVID-19 patients who were hospitalized in Wuhan Union West Campus between 1 February 2020 and 10 March 2020 were enrolled in the retrospective study. Patients were divided into two groups based on the use of ribavirin. The primary endpoint was the time to clinical improvement. The secondary endpoints included mortality, survival time, time to throat swab SARS-CoV-2 nucleic acid negative conversion, and hospital duration.Results: 68 patients were treated with ribavirin while 140 not. There were no significant between-group differences in demographic characteristics, baseline laboratory test results, treatment, and distribution of ordinal scale scores at enrollment, except coexisting diseases especially cancer (ribavirin group vs no ribavirin group, P = 0.014). Treatment with ribavirin was not associated with a difference in the time to clinical improvement (P = 0.483, HR = 0.884, 95% CI = 0.627-1.247). There were also no significant differences between-group in the number of patients with SARS-CoV-2 nucleic acid negative conversion, mortality, survival time, and hospital duration. Conclusion: In hospitalized adult patients with severe or critical COVID-19, no significant benefit was observed with ribavirin treatment.

Cholesterol Metabolism--Impact for SARS-CoV-2 Infection Prognosis, Entry, and Antiviral Therapies (preprint)

Abstract The recently emerged pathogenic SARS-coronavirus 2 (SARS-CoV-2) has spread rapidly, leading to a global pandemic. In this study, we show that SARS-CoV-2 infection was associated with clinically significant lower level of HDL cholesterol (HDL-C), which can be used as indicators of disease severity and poor prognosis. Importantly, we found the spike protein of SARS-CoV-2 (SARS-2-S) bound to HDL. Antagonists of HDL receptor-Scavenger receptor class B type I (SR-B1), strongly inhibited SARS-CoV-2 infection. Notably, the lipids transfer function of SR-B1 was indispensable for this inhibition, offering explanations for the reduced serum HDL level observed in COVID-19 patients. Basing on findings here, we speculate that SR-B1-mediated pulmonary HDL-vitamin E uptake could participate in mediating SARS-CoV-2 infection of lung cells, and the unique expression profile of SR-B1 may also affect SARS-CoV-2 cell and tissue tropism. These findings might help to provide further insights into viral transmission, pathological characteristics and reveal therapeutic targets.

Orthogonal genome-wide screenings in bat cells identify MTHFD1 as a target of broad antiviral therapy (preprint)

Bats are responsible for the zoonotic transmission of several major viral diseases including the 2003 SARS outbreak and the ongoing COVID-19 pandemic. While bat genomic sequencing studies have revealed characteristic adaptations of the innate immune system, functional genomic studies are urgently needed to provide a foundation for the molecular dissection of the tolerance of viral infections in bats. Here we report the establishment and screening of genome-wide RNAi library and CRISPR library for the model megabat, Pteropus Alecto. We used the complementary RNAi and CRISPR libraries to interrogate Pteropus Alecto cells for infection with two different viruses, mumps virus and Influenza A virus, respectively. Screening results converged on the endocytosis pathway and the protein secretory pathway as required for both viral infections. Additionally, we revealed a general dependence of the C-1-tetrahydrofolate synthase gene, MTHFD1, for viral replication in bat cells as well as in human cells. MTHFD1 inhibitor carolacton potently blocked replication of several RNA viruses including SARS-CoV-2. Our studies provide a resource for systematic inquiry into the genetic underpinnings of bat biology and a potential target for developing broad spectrum antiviral therapy.

Correlation Analysis Between Disease Severity and Inflammation-related Parameters in Patients with COVID-19 Pneumonia (preprint)

Aim: The new coronavirus pneumonia (COVID-19) outbreaking at the end of 2019 is highly contagious. Crude mortality rate reached 49% in critical patients. Inflammation matters on disease progression. This study analyzed blood inflammation indicators among mild, severe and critical patients, helping to identify severe or critical patients early. Methods: In this cross-sectional study, 100 patients were included and divided to mild, severe or critical groups. Correlation of peripheral blood inflammation-related indicators with disease criticality was analyzed. Cut-off values for critically ill patients were speculated through the ROC curve. ResultsSignificantly, disease severity were associated with age (R=-0.564, P<0.001), interleukin-2 receptor (IL2R) (R=-0.534, P<0.001), interleukin-6 (IL-6) (R=-0.535, P<0.001), interleukin-8 (IL-8) (R=-0.308, P<0.001), interleukin-10 (IL-10) (R=-0.422, P<0.001), tumor necrosis factor (TNF) (R=-0.322, P<0.001), C-reactive protein (CRP) (R=-0.604, P<0.001), ferroprotein (R=-0.508, P<0.001), procalcitonin (R=-0.650, P<0.001), white cell counts (WBC) (R=-0.54, P<0.001), lymphocyte counts (LC) (R=-0.56, P<0.001), neutrophil count (NC) (R=-0.585, P<0.001) and eosinophil counts (EC) (R=-0.299, P=0.01). ConclusionWith following parameters such as age >67.5 years, IL2R >793.5U/mL, CRP >30.7ng/mL, ferroprotein >2252g/L, WBC>9.5*10^9/L or NC >7.305*10^9/L, the progress of COVID-19 to critical stage should be closely observed and possibly prevented. Inflammation is closely related to severity of COVID-19, and IL-6, TNF and IL-8 might be promising therapeutic targets.