SARS-CoV-2 RNA-dependent RNA polymerase as a target for high-throughput drug screening.

The ongoing COVID-19 pandemic caused by the SARS-CoV-2 has necessitated rapid development of drug screening tools. RNA-dependent RNA polymerase (RdRp) is a promising target due to its essential functions in replication and transcription of viral genome. To date, through minimal RNA synthesizing machinery established from cryo-electron microscopy structural data, there has been development of high-throughput screening assays for directly screening inhibitors that target the SARS-CoV-2 RdRp. Here, we analyze and present verified techniques that could be used to discover potential anti-RdRp agents or repurposing of approved drugs to target the SARS-CoV-2 RdRp. In addition, we highlight the characteristics and application value of cell-free or cell-based assays in drug discovery.

Roles and mechanisms of exosomal microRNAs in viral infections.

Exosomes are small extracellular vesicles with a diameter of 30-150 nm that originate from endosomes and fuse with the plasma membrane. They are secreted by almost all kinds of cells and can stably transfer different kinds of cargo from donor to recipient cells, thereby altering cellular functions for assisting cell-to-cell communication. Exosomes derived from virus-infected cells during viral infections are likely to contain different microRNAs (miRNAs) that can be transferred to recipient cells. Exosomes can either promote or suppress viral infections and therefore play a dual role in viral infection. In this review, we summarize the current knowledge about the role of exosomal miRNAs during infection by six important viruses (hepatitis C virus, enterovirus A71, Epstein-Barr virus, human immunodeficiency virus, severe acute respiratory syndrome coronavirus 2, and Zika virus), each of which causes a significant global public health problem. We describe how these exosomal miRNAs, including both donor-cell-derived and virus-encoded miRNAs, modulate the functions of the recipient cell. Lastly, we briefly discuss their potential value for the diagnosis and treatment of viral infections.

SARS-CoV-2 RNA-dependent RNA polymerase as a target for high-throughput drug screening

The ongoing COVID-19 pandemic caused by the SARS-CoV-2 has necessitated rapid development of drug screening tools. RNA-dependent RNA polymerase (RdRp) is a promising target due to its essential functions in replication and transcription of viral genome. To date, through minimal RNA synthesizing machinery established from cryo-electron microscopy structural data, there has been development of high-throughput screening assays for directly screening inhibitors that target the SARS-CoV-2 RdRp. Here, we analyze and present verified techniques that could be used to discover potential anti-RdRp agents or repurposing of approved drugs to target the SARS-CoV-2 RdRp. In addition, we highlight the characteristics and application value of cell-free or cell-based assays in drug discovery.