Re-defining and tackling the emerging challenges in stem cell research and translation: A report of the 10th CSSCR annual meeting.

The 10th congress of the Chinese Society for Stem Cell Research was held from 11 to 13 October 2020 at Guiyang International Eco-Conference Center in Guizhou (Southwest China) with 700 offline participants (and 500 online participants). With a theme adopted from a poem by Mao Zedong during the long march, 'However difficult it might appear; the challenges will be overcome', the congress provided opportunities for the fast-growing field to exchange ideas among people from academia, industry and regulatory authorities, to help accelerate translation. Eight plenary lectures and six concurrent sessions on cell fate decision, stem cell metabolism, neural stem cells and neural regeneration, organoids and disease models, tissue and organ regeneration and clinical translation of stem cell research were covered, including 77 oral presentations and 75 poster presentations. The congress also included special programmes of a youth forum, a lecture award programme, a flagship journal forum and a dedicated networking session. This 3-day event will significantly boost the stem cell research in an era closing to application.

Relationship between the Chinese Main Air Transport Network and COVID-19 Pandemic Transmission

The COVID-19 pandemic had an unprecedented impact on the civil aviation passenger transport industry. This study analyzes the scale change and spatial distribution of the Chinese main air transport network (CMATN) and its role in the early spread of the pandemic using a complex network analysis method and econometric model. The result shows that CMATN is mainly located in the economically developed and densely populated central and eastern regions of China. The normalized degree, closeness, and betweenness centralities of CMATN node cities show an overall increasing trend, indicating that the air transport network is constantly improving. There was a significant positive relationship between the centrality of node cities, the duration of the COVID-19 pandemic, and the number of confirmed cases, indicating that air transport networks were crucial in the pandemic's early spread. Furthermore, social and economic variables such as GDP and population had a significant positive impact on the duration of the pandemic, indicating that higher levels of social and economic development increased the seriousness of the pandemic. Our findings are expected to supplement existing research and serve as a point of reference for pandemic prevention and control.

A single-cell transcriptomic landscape of the lungs of patients with COVID-19.

The lung is the primary organ targeted by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), making respiratory failure a leading coronavirus disease 2019 (COVID-19)-related mortality. However, our cellular and molecular understanding of how SARS-CoV-2 infection drives lung pathology is limited. Here we constructed multi-omics and single-nucleus transcriptomic atlases of the lungs of patients with COVID-19, which integrate histological, transcriptomic and proteomic analyses. Our work reveals the molecular basis of pathological hallmarks associated with SARS-CoV-2 infection in different lung and infiltrating immune cell populations. We report molecular fingerprints of hyperinflammation, alveolar epithelial cell exhaustion, vascular changes and fibrosis, and identify parenchymal lung senescence as a molecular state of COVID-19 pathology. Moreover, our data suggest that FOXO3A suppression is a potential mechanism underlying the fibroblast-to-myofibroblast transition associated with COVID-19 pulmonary fibrosis. Our work depicts a comprehensive cellular and molecular atlas of the lungs of patients with COVID-19 and provides insights into SARS-CoV-2-related pulmonary injury, facilitating the identification of biomarkers and development of symptomatic treatments.

Immunity-and-matrix-regulatory cells derived from human embryonic stem cells safely and effectively treat mouse lung injury and fibrosis.

Lung injury and fibrosis represent the most significant outcomes of severe and acute lung disorders, including COVID-19. However, there are still no effective drugs to treat lung injury and fibrosis. In this study, we report the generation of clinical-grade human embryonic stem cells (hESCs)-derived immunity- and matrix-regulatory cells (IMRCs) produced under good manufacturing practice requirements, that can treat lung injury and fibrosis in vivo. We generate IMRCs by sequentially differentiating hESCs with serum-free reagents. IMRCs possess a unique gene expression profile distinct from that of umbilical cord mesenchymal stem cells (UCMSCs), such as higher expression levels of proliferative, immunomodulatory and anti-fibrotic genes. Moreover, intravenous delivery of IMRCs inhibits both pulmonary inflammation and fibrosis in mouse models of lung injury, and significantly improves the survival rate of the recipient mice in a dose-dependent manner, likely through paracrine regulatory mechanisms. IMRCs are superior to both primary UCMSCs and the FDA-approved drug pirfenidone, with an excellent efficacy and safety profile in mice and monkeys. In light of public health crises involving pneumonia, acute lung injury and acute respiratory distress syndrome, our findings suggest that IMRCs are ready for clinical trials on lung disorders.