Targeting G9a translational mechanism of SARS-CoV-2 pathogenesis for multifaceted therapeutics of COVID-19 and its sequalae (preprint)

By largely unknown mechanism(s), SARS-CoV-2 hijacks the host translation apparatus to promote COVID-19 pathogenesis. We report that the histone methyltransferase G9a noncanonically regulates viral hijacking of the translation machinery to bring about COVID-19 symptoms of hyperinflammation, lymphopenia, and blood coagulation. Chemoproteomic analysis of COVID-19 patient peripheral mononuclear blood cells (PBMC) identified enhanced interactions between SARS-CoV-2-upregulated G9a and distinct translation regulators, particularly the N6-methyladenosine (m6A) RNA methylase METTL3. These interactions with translation regulators implicated G9a in translational regulation of COVID-19. Inhibition of G9a activity suppressed SARS-CoV-2 replication in human alveolar epithelial cells. Accordingly, multi-omics analysis of the same alveolar cells identified SARS-CoV-2-induced changes at the transcriptional, m6A-epitranscriptional, translational, and post-translational (phosphorylation or secretion) levels that were reversed by inhibitor treatment. As suggested by the aforesaid chemoproteomic analysis, these multi-omics-correlated changes revealed a G9a-regulated translational mechanism of COVID-19 pathogenesis in which G9a directs translation of viral and host proteins associated with SARS-CoV-2 replication and with dysregulation of host response. Comparison of proteomic analyses of G9a inhibitor-treated, SARS-CoV-2 infected cells, or ex vivo culture of patient PBMCs, with COVID-19 patient data revealed that G9a inhibition reversed the patient proteomic landscape that correlated with COVID-19 pathology/symptoms. These data also indicated that the G9a-regulated, inhibitor-reversed, translational mechanism outperformed G9a-transcriptional suppression to ultimately determine COVID-19 pathogenesis and to define the inhibitor action, from which biomarkers of serve symptom vulnerability were mechanistically derived. This cell line-to-patient conservation of G9a-translated, COVID-19 proteome suggests that G9a inhibitors can be used to treat patients with COVID-19, particularly patients with long-lasting COVID-19 sequelae.

Functional Multi-Omics Reveals Noncanonical Function of G9a in Translational Regulation of Chronic Inflammation (preprint)

By largely unknown mechanisms, dysregulated gene-specific translation directly contributes to chronic inflammation-associated diseases such as sepsis and ARDS. Here, we report that G9a, a histone methyltransferase and well-regarded transcriptional repressor, non-canonically or non-epigenetically activates translation of select antimicrobial genes to promote proliferation of cytokine producing macrophages and to impair T cell function; all hallmarks of endotoxin-tolerance related complications including sepsis, ARDS and COVID19. Mechanistically, G9a interacts with translation regulators including METTL3, an N6-methyladenosine or m6A RNA methyltransferase, and methylates it to cooperatively upregulate the translation of certain m6A-modified mRNAs that encode immune checkpoint and anti-inflammatory proteins. Further, translatome proteomic analysis of ET macrophages progressively treated by a G9a inhibitor identified proteins showing G9a-dependent translation that unite the networks associated with hyperinflammation and T cell dysfunction. Overall, we identified a previously unrecognized function of G9a in gene-specific translation that can be leveraged to treat ET-related chronic inflammatory diseases.

Study on the Transmission of COVID-19 in Hubei Province Based on SEIR Model with Intervention Measures (preprint)

Background At the end of 2019, an unidentified coronavirus, named as “COVID-19” by WHO, has broken out in Wuhan, Hubei Province. We aimed to simulate the development trend of COVID-19 in Wuhan and Hubei as well as estimate the number of COVID-19 cases with the government control policies and traffic control.Methods We collected the COVID-19 data in Wuhan and Hubei (January 1, 2020 to April 8, 2020) and simulated three situations about COVID-19 epidemic trend: non-interference, government controlling behavior and traffic control by the SEIR model to analyzed the development and influence of the epidemic.Results We adopted the SEIR model to estimate the number of COVID-19 cases in Hubei peaked on the 107th day without human control, and the number in Wuhan peaked on the 51st day after the lockdown of Wuhan. The number of new cases in Hubei and Wuhan presented a skewed normal distribution in the time series. Government intervention and traffic control had a certain inhibitory effect on the daily increase of COVID-19 cases. During the period from January 23 to April 8, 2020, there was a difference of 1,253,433 cases between the daily number of confirmed cases and the actual number of confirmed cases in Hubei under the simulated state of without human control. Also, there was a difference of 953,202 cases between thedaily number of confirmed cases and the actual number of confirmed cases in Wuhan under the simulated state of without human control.Conclusion The actual COVID-19 outbreak quantity conforms to the simulation results, secondly the government control behavior and the traffic control can effectively inhibit COVID-19 to spread and the efficient can reach 52%. In other countries or regions, an effective intervention measures can control the spread of the epidemic. The earlier the control started and the stronger the control intensity was, the more effective the intervention for the COVID-19 epidemic was, so appropriate to cut off the route of transmission as soon as possible.

Novel gene-specific translation mechanism of dysregulated, chronic inflammation reveals promising, multifaceted COVID-19 therapeutics (preprint)

Hyperinflammation and lymphopenia provoked by SARS-CoV-2-activated macrophages contribute to the high mortality of Coronavirus Disease 2019 (COVID-19) patients. Thus, defining host pathways aberrantly activated in patient macrophages is critical for developing effective therapeutics. We discovered that G9a, a histone methyltransferase that is overexpressed in COVID-19 patients with high viral load, activates translation of specific genes that induce hyperinflammation and impairment of T cell function or lymphopenia. This noncanonical, pro-translation activity of G9a contrasts with its canonical epigenetic function. In endotoxin-tolerant (ET) macrophages that mimic conditions which render patients with pre-existing chronic inflammatory diseases vulnerable to severe symptoms, our chemoproteomic approach with a biotinylated inhibitor of G9a identified multiple G9a-associated translation regulatory pathways that were upregulated by SARS-CoV-2 infection. Further, quantitative translatome analysis of ET macrophages treated progressively with the G9a inhibitor profiled G9a-translated proteins that unite the networks associated with viral replication and the SARS-CoV-2-induced host response in severe patients. Accordingly, inhibition of G9a-associated pathways produced multifaceted, systematic effects, namely, restoration of T cell function, mitigation of hyperinflammation, and suppression of viral replication. Importantly, as a host-directed mechanism, this G9a-targeted, combined therapeutics is refractory to emerging antiviral-resistant mutants of SARS-CoV-2, or any virus, that hijacks host responses.

A Mini Review on Current Clinical and Research Findings for Children Suffering from COVID-19 (preprint)

Background: As the novel coronavirus triggering COVID-19 has broken out in Wuhan, China and spread rapidly worldwide, it threatens the lives of thousands of people and poses a global threat on the economies of the entire world. However, infection with COVID-19 is currently rare in children. Objective To discuss the latest findings and research focus on the basis of characteristics of children confirmed with COVID-19, and provide an insight into the future treatment and research direction. Methods: We searched the terms "COVID-19 OR coronavirus OR SARS-CoV-2" AND "Pediatric OR children" on PubMed, Embase, Cochrane library, NIH, CDC, and CNKI. The authors also reviewed the guidelines published on Chinese CDC and Chinese NHC. Results: We included 25 published literature references related to the epidemiology, clinical manifestation, accessary examination, treatment, and prognosis of pediatric patients with COVID-19. Conclusion: The numbers of children with COVID-19 pneumonia infection are small, and most of them come from family aggregation. Symptoms are mainly mild or even asymptomatic, which allow children to be a risk factor for transmission. Thus, strict epidemiological history screening is needed for early diagnosis and segregation. This holds especially for infants, who are more susceptible to infection than other age groups in pediatric age, but have most likely subtle and unspecific symptoms. They need to be paid more attention to. CT examination is a necessity for screening the suspected cases, because most of the pediatric patients are mild cases, and plain chest X-ray do not usually show the lesions or the detailed features. Therefore, early chest CT examination combined with pathogenic detection is a recommended clinical diagnosis scheme in children. The risk factors which may suggest severe or critical progress for children are: Fast respiratory rate and/or; lethargy and drowsiness mental state and/or; lactate progressively increasing and/or; imaging showed bilateral or multi lobed infiltration, pleural effusion or rapidly expending of lesions in a short period of time and/or; less than 3 months old or those who underly diseases. For those critical pediatric patients with positive SARS-CoV-2 diagnosis, polypnea may be the most common symptom. For treatment, the elevated PCT seen in children in contrast to adults suggests that the underlying coinfection/secondary infection may be more common in pediatric patients and appropriate antibacterial treatment should be considered. Once cytokine storm is found in these patients, anti-autoimmune or blood-purifying therapy should be given in time. Furthermore, effective isolation measures and appropriate psychological comfort need to be provided timely.

Exploration on the emergency support mode of hospital medical supplies under the epidemic of NCP / 中华医院管理杂志

Since the outbreak of Novel Coronavirus Pneumonia(NCP), hospitals have taken the fight against the virus as its own responsibility, and keep standing in the front line of epidemic prevention and control. The continuous input of anti-epidemic forces in hospitals also brings challenges to the medical supplies support, including the management of protective supplies and the maintenance of medical equipment. In the face of increasing security pressure, the medical materials support team broke the game on multiple fronts. Firstly, the team implements active material procurement strategy, sets material distribution priority according to risk level, releases materials uniformly based on stock and use, and implements traceability management of donated materials to ensure material supply. Secondly, centralized allocation management of equipment, emergency installation, advanced maintenance and emergency maintenance work is effectively completed. Thirdly, disinfection strategies for items and equipment are developed safely and effectively with the aid of disinfection equipment functions. At last, personnel management and training have been strengthened. These measures have provided strong support for the orderly prevention and control of the epidemic.