The recent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, previously known as 2019-nCoV) outbreak has engulfed an unprepared world amidst a festive season. The zoonotic SARS-CoV-2, believed to have originated from infected bats, is the seventh member of enveloped RNA coronavirus. Specifically, the overall genome sequence of the SARS-CoV-2 is 96.2% identical to that of bat coronavirus termed BatCoV RaTG13. Although the current mortality rate of 2% is significantly lower than that of SARS (9.6%) and Middle East respiratory syndrome (MERS)

SummaryNicotinamide, the amide form of vitamin B3, is widely used in disease treatments and stem cell applications. However, nicotinamide's impact often cannot be attributed to its nutritional functions. In a vitamin screen, we find that nicotinamide promotes cell survival and differentiation in human pluripotent stem cells. Nicotinamide inhibits the phosphorylation of myosin light chain, suppresses actomyosin contraction, and leads to improved cell survival after individualization. Further analysis demonstrates that nicotinamide is an inhibitor of multiple kinases, including ROCK and casein kinase 1. We demonstrate that nicotinamide affects human embryonic stem cell pluripotency and differentiation as a selective kinase inhibitor. The findings in this report may help researchers design better strategies to develop nicotinamide-related stem cell applications and disease treatments.

Background: The novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, also called 2019-nCoV) causes different morbidity risks to individuals in different age groups. This study attempts to quantify the age-specific transmissibility using a mathematical model. Methods: An epidemiological model with five compartments (susceptible-exposed-symptomatic-asymptomaticrecovered/removed [SEIAR]) was developed based on observed transmission features. Coronavirus disease 2019 (COVID-19) cases were divided into four age groups: group 1, those ≤ 14 years old; group 2, those 15 to 44 years old; group 3, those 45 to 64 years old; and group 4, those ≥ 65 years old. The model was initially based on cases (including imported cases and secondary cases) collected in Hunan Province from January 5 to February 19, 2020. Another dataset, from Jilin Province, was used to test the model.

In view of the high incidence of diabetic retinopathy and the functionality of long non-coding RNA (lncRNA) maternally expressed gene 3 (MEG3) in different disease models, the present study aimed to investigate the role of MEG3 in diabetic retinopathy. In the study, patients with diabetic retinopathy, diabetic patients without retinopathy as well as healthy people were included. Fasting blood was extracted from each participant. Serum MEG3 levels were detected by everse transcription-quantitative polymerase chain reaction (RT-qPCR) and serum vascular endothelial growth factor (VEGF) and transforming growth factor-β1 (TGF-β1) levels were detected by ELISA. Also, the effects of high glucose treatment on the expression of MEG3 and VEGF and the effects of MEG3 overexpression on expression of VEGF and TGF-β1 in high glucose-treated ARPE-19 cells were detected by RT-qPCR and western blot analysis to determine the mRNA and protein levels, respectively. It was indicated that serum levels of MEG3 were significantly lower, while the serum levels of VEGF and TGF-β1 were significantly higher in patients with diabetic retinopathy and diabetic patients without retinopathy compared with the healthy controls. Furthermore, slight differences were found between patients with diabetic retinopathy and diabetic patients without retinopathy; however, these differences were not significant. The findings indicated that high glucose upregulated the expression of VEGF mRNA and downregulated the expression of MEG3, MEG3 overexpression reduced the increased expression levels of VEGF and TGF-β1 induced by high glucose treatment. Therefore, it was concluded that lncRNA MEG3 overexpression may inhibit the development of diabetic retinopathy by inhibiting TGF-β1 and VEGF expression.

Most breast cancers at an advanced stage exhibit an aggressive nature, and there is a lack of effective anticancer options. Herein, the development of patient-derived organoids (PDOs) is described as a real-time platform to explore the feasibility of tailored treatment for refractory breast cancers. PDOs are successfully generated from breast cancer tissues, including heavily treated specimens. The microtubule-targeting drug-sensitive response signatures of PDOs predict improved distant relapse-free survival for invasive breast cancers treated with adjuvant chemotherapy. It is further demonstrated that PDO pharmaco-phenotyping reflects the previous treatment responses of the corresponding patients. Finally, as clinical case studies, all patients who receive at least one drug predicate to be sensitive by PDOs achieve good responses. Altogether, the PDO model is developed as an effective platform for evaluating patient-specific drug sensitivity in vitro, which can guide personal treatment decisions for breast cancer patients at terminal stage.