Ye Liu

Bio: Ye Liu is an academic researcher from Sun Yat-sen University. The author has contributed to research in topics: Medicine & Cancer research. The author has an hindex of 3, co-authored 5 publications receiving 1701 citations.

Evidence for gastrointestinal infection of SARS-CoV-2

Abstract: The new coronavirus (SARS-CoV-2) outbreak originating from Wuhan, China, poses a threat to global health. While it’s evident that the virus invades respiratory tract and transmits from human to human through airway, other viral tropisms and transmission routes remain unknown. We tested viral RNA in stool from 73 SARS-CoV-2-infected hospitalized patients using rRT-PCR. 53.42% of the patients tested positive in stool. 23.29% of the patients remained positive in feces even after the viral RNA decreased to undetectable level in respiratory tract. The viral RNA was also detected in gastrointestinal tissues. Furthermore, gastric, duodenal and rectal epithelia showed positive immunofluorescent staining of viral host receptor ACE2 and viral nucleocapsid protein in a case of SARS-CoV-2 infection. Our results provide evidence for gastrointestinal infection of SARS-CoV-2, highlighting its potential fecal-oral transmission route.

Glycyrrhizic Acid Nanoparticles as Antiviral and Anti-inflammatory Agents for COVID-19 Treatment.

Abstract: COVID-19 has been diffusely pandemic around the world, characterized by massive morbidity and mortality. One of the remarkable threats associated with mortality may be the uncontrolled inflammatory processes, which were induced by SARS-CoV-2 in infected patients. As there are no specific drugs, exploiting safe and effective treatment strategies is an instant requirement to dwindle viral damage and relieve extreme inflammation simultaneously. Here, highly biocompatible glycyrrhizic acid (GA) nanoparticles (GANPs) were synthesized based on GA. In vitro investigations revealed that GANPs inhibit the proliferation of the murine coronavirus MHV-A59 and reduce proinflammatory cytokine production caused by MHV-A59 or the N protein of SARS-CoV-2. In an MHV-A59-induced surrogate mouse model of COVID-19, GANPs specifically target areas with severe inflammation, such as the lungs, which appeared to improve the accumulation of GANPs and enhance the effectiveness of the treatment. Further, GANPs also exert antiviral and anti-inflammatory effects, relieving organ damage and conferring a significant survival advantage to infected mice. Such a novel therapeutic agent can be readily manufactured into feasible treatment for COVID-19.

SARS-CoV-2 membrane protein causes the mitochondrial apoptosis and pulmonary edema via targeting BOK

Abstract: Deaths caused by coronavirus disease 2019 (COVID-19) are largely due to the lungs edema resulting from the disruption of the lung alveolo-capillary barrier, induced by SARS-CoV-2-triggered pulmonary cell apoptosis. However, the molecular mechanism underlying the proapoptotic role of SARS-CoV-2 is still unclear. Here, we revealed that SARS-CoV-2 membrane (M) protein could induce lung epithelial cells mitochondrial apoptosis. Notably, M protein stabilized B-cell lymphoma 2 (BCL-2) ovarian killer (BOK) via inhibiting its ubiquitination and promoted BOK mitochondria translocation. The endodomain of M protein was required for its interaction with BOK. Knockout of BOK by CRISPR/Cas9 increased cellular resistance to M protein-induced apoptosis. BOK was rescued in the BOK-knockout cells, which led to apoptosis induced by M protein. M protein induced BOK to trigger apoptosis in the absence of BAX and BAK. Furthermore, the BH2 domain of BOK was required for interaction with M protein and proapoptosis. In vivo M protein recombinant lentivirus infection induced caspase-associated apoptosis and increased alveolar-capillary permeability in the mouse lungs. BOK knockdown improved the lung edema due to lentivirus-M protein infection. Overall, M protein activated the BOK-dependent apoptotic pathway and thus exacerbated SARS-CoV-2 associated lung injury in vivo. These findings proposed a proapoptotic role for M protein in SARS-CoV-2 pathogenesis, which may provide potential targets for COVID-19 treatments. In SARS-CoV-2-infected lung epithelial cells, endodomain of M protein binds to the BH2 domain of BOK and inhibits ubiquitination. BOK is stabilized and translocate to the mitochondrial outer membrane, promoting Cyt c release. Cyt c released outside the mitochondria activates CASP 9 mediated apoptosis, thereby inducing pulmonary edema.

Hypersensitivity may be involved in severe COVID-19.

Abstract: Deaths attributed to Coronavirus Disease 2019 (COVID-19) are mainly due to severe hypoxemic respiratory failure. Although the inflammatory storm has been considered main pathogenesis of severe COVID-19, hypersensitivity may be another important mechanism involved in severe cases, which have perfect response to corticosteroids (CS). We detected the presence of anti-SARS-CoV-2-spike S1 protein specific IgE (SP- IgE) and SARS-CoV-2 nucleocapsid protein specific IgE (NP- IgE) in all COVID-19 patients' serum, while it was rarely detected in non-COVID-19 controls. Additionally, the levels of serum SP- IgE and NP- IgE were significantly higher in severe cases, and which were correlations with the total lung severity scores (TLSS) and the PaO2 /FiO2 ratio. In both airway and intestinal tissues obtained from severe COVID-patients via endoscopy, NP could be stained and detected in activated mast cells, which was binded with IgE. After application of CS in severe COVID-19, SP- IgE and NP- IgE decreased, but maintained at high level in early convalescence, which were maybe reason of airway hyperresponsiveness (AHR) in these patients partly. Overall, our study revealed that the chief mechanism of severe COVID-19-related hypoxemic respiratory failure is likely hypersensitivity reactions directly involving SARS-CoV-2 antigens, anti-SARS-CoV-2-specific IgE, and mast cells. Moreover, in our cohort of COVID-19 patients, severe COVID-19 patients with increased SP- IgE and NP-IgE and hypoxemic respiratory failure were treated with pulse methylprednisolone and achieved an excellent response. In conclusion, hypersensitivity may be involved in severe COVID-19.

Post-acute COVID-19 syndrome.

Abstract: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the pathogen responsible for the coronavirus disease 2019 (COVID-19) pandemic, which has resulted in global healthcare crises and strained health resources. As the population of patients recovering from COVID-19 grows, it is paramount to establish an understanding of the healthcare issues surrounding them. COVID-19 is now recognized as a multi-organ disease with a broad spectrum of manifestations. Similarly to post-acute viral syndromes described in survivors of other virulent coronavirus epidemics, there are increasing reports of persistent and prolonged effects after acute COVID-19. Patient advocacy groups, many members of which identify themselves as long haulers, have helped contribute to the recognition of post-acute COVID-19, a syndrome characterized by persistent symptoms and/or delayed or long-term complications beyond 4 weeks from the onset of symptoms. Here, we provide a comprehensive review of the current literature on post-acute COVID-19, its pathophysiology and its organ-specific sequelae. Finally, we discuss relevant considerations for the multidisciplinary care of COVID-19 survivors and propose a framework for the identification of those at high risk for post-acute COVID-19 and their coordinated management through dedicated COVID-19 clinics.

Extrapulmonary manifestations of COVID-19.

Abstract: Although COVID-19 is most well known for causing substantial respiratory pathology, it can also result in several extrapulmonary manifestations. These conditions include thrombotic complications, myocardial dysfunction and arrhythmia, acute coronary syndromes, acute kidney injury, gastrointestinal symptoms, hepatocellular injury, hyperglycemia and ketosis, neurologic illnesses, ocular symptoms, and dermatologic complications. Given that ACE2, the entry receptor for the causative coronavirus SARS-CoV-2, is expressed in multiple extrapulmonary tissues, direct viral tissue damage is a plausible mechanism of injury. In addition, endothelial damage and thromboinflammation, dysregulation of immune responses, and maladaptation of ACE2-related pathways might all contribute to these extrapulmonary manifestations of COVID-19. Here we review the extrapulmonary organ-specific pathophysiology, presentations and management considerations for patients with COVID-19 to aid clinicians and scientists in recognizing and monitoring the spectrum of manifestations, and in developing research priorities and therapeutic strategies for all organ systems involved.