With the continuous development of messenger RNA (mRNA) technology, mRNA-based drugs have shown broad application prospects in recent years. Since mRNA is easy to be degraded and difficult to enter cells directly, the mRNA delivery vectors have always been one of the focuses in the development of mRNA-based drugs. Although lipid nanoparticles (LNPs) have been widely used for the delivery of mRNA, they tend to accumulate in the liver, and repeated administration can easily induce inflammatory response which leads to tissue damage. Compared with LNPs, virus-like particles (VLPs) have the advantages of high biocompatibility and safety, being expected to offer new solutions for mRNA delivery. Based on the practical application requirements, this review summarized the research progress in VLPs according to the mRNA delivery steps: particle assembly, delivery into cells, and intracellular release. We hope to provide a basis and design ideas for the development of new VLPs as delivery vectors, promote the application of VLPs in mRNA delivery, and provide new possibilities for the research and application of mRNA-based therapeutics.
RNA, Messenger/administration & dosage* ; Humans ; Nanoparticles/chemistry* ; Genetic Vectors ; Lipids/chemistry* ; Drug Delivery Systems/methods* ; Virion ; Animals ; Gene Transfer Techniques ; Liposomes

Objective To investigate the effect and mechanism of melatonin on the anoikis of melanoma cells.Methods The drug concentration of melatonin inhibiting melanoma cell line B16-F10 was optimized based on the effect on CCK-8 assay.An anti-anoikis of melanoma cell model was developed and divided it into four groups:The blank control group,the TrkB activator group,the melatonin group and the melatonin+TrkB activator group.Calce-in AM/EthD-1 fluorescence double staining was used to detect the anoikis of melanoma cells.Reactive oxygen spe-cies were detected using the fluorescent probe DCFH-DA.Western blot was used to detect the expression of Nrf2 protein and TrkB protein in each group.Results Melatonin significantly inhibited the proliferation of melanoma cells in a time-and dose-dependent manner with IC50 of 1×10-7 μmol/L.Its inhibitory effect was found to be related to in-duction of anoikis of melanoma cells.Melatonin could upregulate the generation of cellular reactive oxygen species(P<0.05),while addition of TrkB activator antagonized this effect.Melatonin could reduce the expression of Nrf2 protein and TrkB protein in melanoma cells(P<0.05),and the addition of TrkB activator could inhibite the effect of melatonin on the expression of Nrf2 protein and TrkB protein(P<0.05).Conclusions Melatonin can inhibit the pro-liferation of melanoma cell line B16-F10 through the mechanism of inducing anoikis.

Objective:To study the repair impact of recombinant human collagen Ⅲ(rhCol Ⅲ)hydrogel with sus-tained cell-free fat extract(CEFFE)release on spinal cord injury(SCI).Methods:The rhCol Ⅲ hydrogel was com-bined with CEFFE to create a composite scaffold capable of releasing CEFFE.Rats with SCI hemicut models were divid-ed into three groups:SCI,rhCol Ⅲ,and rhCol Ⅲ/CEFFE.Results:The rhCol Ⅲ/CEFFE hydrogel features a three-dimensional(3D)porous structure and suitable elasticity,enabling continuous CEFFE release.This group demonstra-ted notable motor function improvement and more complete spinal cord tissue continuity compared to other greups.The enzyme-linked immunosorbent assay(ELISA),Luxol fast blue staining(LFB),and immunofluorescence results dem-onstrated that RhCol Ⅲ/CEFFE hydrogel inhibits inflammatory factors,encourages microglia M2 transformation,reduces glial scar formation,and promotes neuronal differentiation,axonal regeneration,and myelin sheath formation.Conclusion:The rhCol Ⅲ/CEFFE hydrogel reshapes the inhibitory microenvironment,supports nerve regeneration and neural network formation,and aids in neural function recovery.

Objective:To study the repair impact of recombinant human collagen Ⅲ(rhCol Ⅲ)hydrogel with sus-tained cell-free fat extract(CEFFE)release on spinal cord injury(SCI).Methods:The rhCol Ⅲ hydrogel was com-bined with CEFFE to create a composite scaffold capable of releasing CEFFE.Rats with SCI hemicut models were divid-ed into three groups:SCI,rhCol Ⅲ,and rhCol Ⅲ/CEFFE.Results:The rhCol Ⅲ/CEFFE hydrogel features a three-dimensional(3D)porous structure and suitable elasticity,enabling continuous CEFFE release.This group demonstra-ted notable motor function improvement and more complete spinal cord tissue continuity compared to other greups.The enzyme-linked immunosorbent assay(ELISA),Luxol fast blue staining(LFB),and immunofluorescence results dem-onstrated that RhCol Ⅲ/CEFFE hydrogel inhibits inflammatory factors,encourages microglia M2 transformation,reduces glial scar formation,and promotes neuronal differentiation,axonal regeneration,and myelin sheath formation.Conclusion:The rhCol Ⅲ/CEFFE hydrogel reshapes the inhibitory microenvironment,supports nerve regeneration and neural network formation,and aids in neural function recovery.

Objective : To investigate the expression and clinical significance of classic vascular endothelial growth factor A (VEGFA) and vasotropic mimicry factor matrix metalloproteinase 14 (MMP⁃14) in lung adenocarcinoma(LUAD) . Methods : The expression levels of MMP⁃14 and VEGFA genes and proteins in LUAD and their correlation with survival and prognosis were analyzed using TCGA and UALCAN databases . Serum of 69 patients with LUAD and 20 healthy subjects (control group) was collected , and the contents of MMP⁃14 and VEGFA were detected by ELISA and chemiluminescence , respectively , to analyze the correlation between the two and the clinicopathological features of tumors and their value in prediction and diagnosis of LUAD . Results: The levels of MMP⁃14 and VEGFA in LUAD tissues and serum were higher than those in control group . There were significant differences in serum VEGFA and MMP⁃14 expression levels among early stage group , advanced stage group and control group (P< 0. 001) . MMP⁃14 was higher in T3 /T4 stage than that in T1 /T2 stage (P = 0. 045) , higher in N2 /N3 stage than that in N0 /N1 stage (P = 0. 035) , and higher in the pleural metastasis group than that in the non⁃pleural metastasis group (P = 0. 034) . VEGFA level was higher in M 1 than M0 (P = 0. 025) . Elevated VEGFA level was a risk factor for LUAD (P = 0. 002) . The area under the curve (AUC) of MMP⁃14 , VEGFA and CEA alone was 0. 793 , 0. 849 and 0. 851 , respectively , and the AUC of the combined test was 0. 952 . The overall survival ( OS) and disease specific survival (DSS) of MMP⁃14 and VEGFA low expression group were longer than those of MMP⁃14 and VEGFA high expression group (P < 0. 05) . Conclusion High expression of MMP⁃14 and VEGFA in LUAD is associated with the growth , invasion and metastasis of LUAD , respectively , and has implications for survival prognosis determination .

Rotavirus (RV) is one of the leading causes of acute gastroenteritis in infants and young animals worldwide. Rotavirus infection has obvious species specificity and mainly causes diarrhea in infants and young animals. The host innate responses suppress the infection and replication of rotavirus through activating multiple signaling pathways. Meanwhile, rotavirus also antagonizes the innate immune responses in various ways. This article reviewed the mechanisms of host innate immune responses to rotavirus infection and the antagonistic mechanism of rotavirus against host innate immunity with a view to providing reference for the development of therapeutic drugs and the prevention of rotavirus infection.

Targeted protein degradation (TPD) technology facilitates specific and efficient degradation of disease-related proteins through hijacking the two major protein degradation systems in mammalian cells: ubiquitin-proteasome system and lysosome pathway. Compared with traditional small molecule-inhibitors, TPD-based drugs exhibit the characteristics of a broader target spectrum. Compared with techniques interfere with protein expression on the gene and mRNA level, TPD-based drugs are target-specific, efficaciously rapid, and not constrained by post-translational modification of proteins. In the past 20 years, various TPD-based technologies have been developed. Most excitingly, two TPD-based therapeutic drugs have been approved by FDA for phase Ⅰ clinical trials in 2019. Despite of the early stage characteristics and various obstructions of the TPD technology, it could serve as a powerful tool for the development of novel drugs. This review summarizes the advances of different degradation systems based on TPD technologies and their applications in disease therapy. Moreover, the advantages and challenges of various technologies were discussed systematically, with the aim to provide theoretical guidance for further application of TPD technologies in scientific research and drug development.
Animals ; Proteasome Endopeptidase Complex/metabolism* ; Protein Processing, Post-Translational ; Proteins/metabolism* ; Proteolysis ; Technology

With the requirements of early diagnosis, biomarker development and functional definition, the challenge of sensitivity of immunoassay has become increasingly prominent. How to improve it to break the bottleneck has become a major challenge in the field of bioassays. Amplifying the immunosignal is the most direct method to improve detection sensitivity. Biotin-avidin system (BAS), tyramide signal amplification (TSA) and immuno-polymerase chain reaction (Im-PCR) are the most classic signal amplification techniques which significantly improved the sensitivity of immunoassays. In recent years, studies have confirmed that the sensitivity of immunoassays can be further increased by approximately three orders of magnitude with the invention of techniques including catalyzed reporter deposition-based signal amplification, nanotechnologies-based signal amplification and hybridization chain reaction-based signal amplification. Herein, we will summarize the techniques that have been developed in recent years for amplifying the signals of immunodetection and comparatively analyze their advantages and disadvantages in order to provide reference for the developed techniques transformed to clinical application and further research on ultrasensitive immunoassays.

In previous studies, we found that truncated rotavirus VP4* (aa 26-476) could be expressed in soluble form in Escherichia coli and confer high protection against rotavirus in the mouse mode. In this study, we further improved the immunogenicity of VP4* by polymerization. The purified VP4* was polymerized through incubation at 37 ℃ for 24 h, and then the homogeneity of the particles was analyzed by HPLC, TEM and AUC, while the thermal stability and antigenicity was analyzed by DSC and ELISA, respectively. Finally, the immunogenicity and protective efficacy of the polymers analyzed by a mouse maternal antibody model. The results showed that VP4* aggregated into homogeneous polymers, with high thermostability and neutralizing antibody binding activity. In addition, VP4* polymers (endotoxin <20 EU/dose) stimulated higher neutralizing antibodies and confer higher protection against rotavirus-induced diarrhoea compared with the VP4* trimers when immunized with aluminium adjuvant. In summary, the study in VP4* polymers provides a new strategy for the development of recombinant rotavirus vaccines.
Animals ; Antibodies, Viral ; Antigens, Viral ; Capsid ; Capsid Proteins ; Mice ; Polymerization ; Rotavirus ; Rotavirus Infections

Reverse genetics approaches can directly manipulate the genome of virus at the gene level, making it possible to quickly, directly and thoroughly study the mechanisms of virus replication and pathogenesis. At present, many viruses of the family Reoviridae, such as mammalian orthoreovirus ( MRV) and bluetongue virus ( BTV) , have made great progress in basic viral research using the powerful tool of re-verse genetics. However, for members of the genus Rotavirus in the family Reoviridae, progress in the con-struction of reverse genetic systems has been slow. The remarkable reverse genetics system based on helper-viruses was established in 2006, and it was not until 2017 that the entirely plasmid-based reverse genetics system was successfully established. This paper briefly reviewed the development of reverse genetics systems for rotavirus and prospected the direction for future research in order to provide technical support for acceler-ating the basic research on mechanisms of rotavirus infection.