Stability of SARS-CoV-2 on Cold-chain Food (preprint)

Although close exposure to respiratory droplets from an infected patient is the main transmission route of SARS-CoV-2, touching contaminated surfaces and objects might also contribute to transmission of this virus. There are increasing reports that cold-chain food and food packages have been tested with SARS-CoV-2, raising concerns that importation of contaminated food could be a source for transmission of SARS-CoV-2. The survival of SARS-CoV-2 on cold-chain food was investigated. We found SARS-CoV-2 remained viable for more than three weeks on both beef and mutton at 4°C. Furthermore, at freezing temperature, SARS-CoV-2 can easily survive for more than eight weeks. Our study showed the ability of SARS-CoV-2 to survive for a long time on cold-chain food at low temperatures.

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.

Progress in the development of baicalein and its clinical pharmacology study

The 2019 new coronavirus pneumonia (COVID-19) caused by the new coronavirus (SARS-Cov-2) infection has become a global pandemic, and currently there is a lack of specific antiviral drugs. Traditional Chinese medicine plays a critical role in the treatment of COVID-19. Scutellaria baicalensis is an important component of the Qingfei Paidu decoction recommended in the Chinese National Health Commission's Treatment Regimen and Wuhan Xiehe No.2 and No.3 prescriptions as well. Baicalein is the main ingredient in Scutellaria baicalensis, and has various pharmacological effects such as antiviral, antibacterial, antiallergic, and immunomodulatory activities, showing a broad prospect in new drug development. This article systemically reviewed the recent progress in the preclinical and clinical studies, potential drug interactions, and other aspects of baicalein, which will help further development and clinical application of the drug.

Continuity of services for patients with tuberculosis in China in the COVID-19 era (preprint)

It is crucial to maintain continuity of essential services for people affected by tuberculosis (TB). Efforts to deliver these essential services in many global settings have been complicated by the emergence and global spread of SARS-CoV-2 and the pandemic of COVID-19. Understanding how the COVID-19 pandemic has impacted the availability of TB diagnostic and treatment services is critical for identifying policies that can mitigate disruptions of these essential services. China has a dual burden of TB and COVID-19. We conducted a survey and collected data from 13 provinces in China to evaluate the early impact of COVID-19 on TB services and to document interventions that were adopted to maintain the continuity services for TB patients during the pandemic. We use these data to identify additional opportunities that will improve the ability of TB programs to maintain essential services during this crisis. While health systems and underlying epidemiology differ between countries, we believe that sharing China's experience can inform the design of locally tailored strategies to maintain essential TB services during the COVID-19 pandemic.

Stability of SARS-CoV-2 on environmental surfaces and in human excreta (preprint)

At room temperature, SARS-CoV-2 was stable on environmental surfaces and remained viable up to 7 days on smooth surfaces. This virus could survive for several hours in feces and 3-4 days in urine.

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.