Zoonotic origins of human coronavirus 2019(HCoV-19/SARS-CoV-2):why is this work important?

The ongoing pandemic of coronavirus disease 2019 (COVID-19), caused by infection with human coronavirus 2019 (HCoV-19/SARS-CoV-2/2019-nCoV), is a global threat to the human population. Here, we briefly summarize the available data for the zoonotic origins of HCoV-19, with reference to the other two epidemics of highly virulent coronaviruses, SARSCoV and MERS-CoV, which cause severe pneumonia in humans. We propose to intensify future efforts for tracing the origins of HCoV-19, which is a very important scientific question for the control and prevention of the pandemic.

Transcription factor networks involved in cell death in the dorsal root ganglia following peripheral nerve injury

The peripheral nervous system has the potential to regenerate after nerve injury owing to the intrinsic regrowth ability of neurons and the permissive microenvironment.The regenerative process involves numerous gene expression changes,in which transcription factors play a critical role.Previously,we profiled dysregulated genes in dorsal root ganglion neurons at different time points（0,3 and 9 hours,and 1,4 and 7 days） after sciatic nerve injury in rats by RNA sequencing.In the present study,we investigated differentially expressed transcription factors following nerve injury,and we identified enriched molecular and cellular functions of these transcription factors by Ingenuity Pathway Analysis.This analysis revealed the dynamic changes in the expression of transcription factors involved in cell death at different time points following sciatic nerve injury.In addition,we constructed regulatory networks of the differentially expressed transcription factors in cell death and identified some key transcription factors（such as STAT1,JUN,MYC and IRF7）.We confirmed the changes in expression of some key transcription factors（STAT1 and IRF7） by quantitative reverse transcription-polymerase chain reaction.Collectively,our analyses provide a global overview of transcription factor changes in dorsal root ganglia after sciatic nerve injury and offer insight into the regulatory transcription factor networks involved in cell death.

miR-30c promotes Schwann cell remyelination following peripheral nerve injury

Differential expression of mi RNAs occurs in injured proximal nerve stumps and includes mi RNAs that are firstly down-regulated and then gradually up-regulated following nerve injury.These mi RNAs might be related to a Schwann cell phenotypic switch.mi R-30 c,as a member of this group,was further investigated in the current study.Sprague-Dawley rats underwent sciatic nerve transection and proximal nerve stumps were collected at 1,4,7,14,21,and 28 days post injury for analysis.Following sciatic nerve injury,mi R-30 c was down-regulated,reaching a minimum on day 4,and was then upregulated to normal levels.Schwann cells were isolated from neonatal rat sciatic nerve stumps,then transfected with mi R-30 c agomir and co-cultured in vitro with dorsal root ganglia.The enhanced expression of mi R-30 c robustly increased the amount of myelin-associated protein in the co-cultured dorsal root ganglia and Schwann cells.We then modeled sciatic nerve crush injury in vivo in Sprague-Dawley rats and tested the effect of perineural injection of mi R-30 c agomir on myelin sheath regeneration.Fourteen days after surgery,sciatic nerve stumps were harvested and subjected to immunohistochemistry,western blot analysis,and transmission electron microscopy.The direct injection of mi R-30 c stimulated the formation of myelin sheath,thus contributing to peripheral nerve regeneration.Overall,our findings indicate that mi R-30 c can promote Schwann cell myelination following peripheral nerve injury.The functional study of mi R-30 c will benefit the discovery of new therapeutic targets and the development of new treatment strategies for peripheral nerve regeneration.