BACKGROUNDTo investigate the biological effects of anti VEGF₁₆₅ ribozyme on human lung adenocarcinoma cell.

METHODSHammerhead ribozyme (VRz) against VEGF₁₆₅ gene transcripts (site 212) and its paired mutant ribozyme (mVRz) were designed and synthesized, and the cleavage activity of the ribozymes on target RNA in a cell-free system was observed. The replication-incompetent adenovirus-mediated eukaryotic expression vectors (rpAdVRz) containing VRz and mVRz gene were constructed and identified. Then the human lung adenocarcinoma cells (A549) were infected with recombinant adenovirus. The biological characteristics of A549 cell before and after infection in vitro were inspected by Northern blot, laser confocal imaging system analysis, flow cytometry and transmission electron microscopy.

RESULTSVRz specifically and efficiently cleaved the VEGF₁₆₅ mRNA. The rpAdVRz was successfully constructed and infected A549 cell. The level of VEGF₁₆₅ expression decreased 87% in rpAdVRz infected cells compared with the other groups, but their biological characteristics were not influenced by the expression of the exogenous gene.

CONCLUSIONSThe adenovirus mediated hammerhead ribozyme against VEGF₁₆₅ can significantly decrease the expression of VEGF₁₆₅. This provides an experimental basis for human lung cancer gene therapy with antiangiogenesis method.

Tuberculosis （TB） and human immunodeficiency virus infection / acquired immune deficiency syndrome （HIV/AIDS） are both serious global public health threats. Early detection of infected persons and/or patients through TB/HIV bi-directional screening is crucial for prevention and control strategy in China and globally. In recent years， with the promotion and application of new TB and HIV detection technologies worldwide， TB/HIV bi-directional screening technologies and strategies have made remarkable changes. This expert consensus introduces the significance and challenges of TB/HIV bi-directional screening， summarizes important progress of research and applications， and makes recommendations on screening measures and procedures to further strengthen TB/HIV bi-directional screening in China.

The nucleocapsid (N) protein of SARS-CoV-2 has been reported to have a high ability of liquid-liquid phase separation, which enables its incorporation into stress granules (SGs) of host cells. However, whether SG invasion by N protein occurs in the scenario of SARS-CoV-2 infection is unknow, neither do we know its consequence. Here, we used SARS-CoV-2 to infect mammalian cells and observed the incorporation of N protein into SGs, which resulted in markedly impaired self-disassembly but stimulated cell cellular clearance of SGs. NMR experiments further showed that N protein binds to the SG-related amyloid proteins via non-specific transient interactions, which not only expedites the phase transition of these proteins to aberrant amyloid aggregation in vitro, but also promotes the aggregation of FUS with ALS-associated P525L mutation in cells. In addition, we found that ACE2 is not necessary for the infection of SARS-CoV-2 to mammalian cells. Our work indicates that SARS-CoV-2 infection can impair the disassembly of host SGs and promote the aggregation of SG-related amyloid proteins, which may lead to an increased risk of neurodegeneration.
Amyloidogenic Proteins/metabolism* ; Amyotrophic Lateral Sclerosis/genetics* ; Animals ; COVID-19 ; Cytoplasmic Granules/metabolism* ; Mammals ; SARS-CoV-2 ; Stress Granules