ABSTRACT
Background@#Inactivated vaccines are limited in preventing foot-and-mouth disease (FMD) due to safety problems. Recombinant virus-like particles (VLPs) are an excellent candidate for a novel vaccine for preventing FMD, given that VLPs have similar immunogenicity as natural viruses and are replication- and infection-incompetent. @*Objectives@#The 3C protease and P1 polyprotein of type O FMD virus (FDMV) was expressed in yeast Hansenula polymorpha to generate self-resembling VLPs, and the potential of recombinant VLPs as an FMD vaccine was evaluated. @*Methods@#BALB/c mice were immunized with recombinant purified VLPs using CpG oligodeoxynucleotide and aluminum hydroxide gel as an adjuvant. Cytokines and lymphocytes from serum and spleen were analyzed by enzyme-linked immunosorbent assay, enzyme-linked immunospot assay, and flow cytometry. @*Results@#The VLPs of FMD were purified successfully from yeast protein with a diameter of approximately 25 nm. The immunization of mice showed that animals produced high levels of FMDV antibodies and a higher level of antibodies for a longer time. In addition, higher levels of interferon-γ and CD4 + T cells were observed in mice immunized with VLPs. @*Conclusions@#The expression of VLPs of FMD in H. polymorpha provides a novel strategy for the generation of the FMDV vaccine.
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Background and Objectives@#Induced pluripotent stem cells (iPSCs) are usually generated by reprogramming differentiated cells through the introduction of specific transcription factors, but this is a difficult and inefficient process.Valproic acid (VPA) is a histone deacetylase inhibitor that significantly improves the efficiency of iPSC generation.But its role and mechanism are still unclear. @*Methods@#and Results: We transduced Bactrian camel fetal fibroblasts (BCFFs) with retroviruses carrying defined factors (OCT4, SOX2, KLF4, c-MYC and EGFP; OSKMG) in the presence of VPA. Cells were collected (Day 7) and analyzed using RNA-seq technology. Afterwards, different groups of cells and transcriptomics results were detected by PCR and qRT-PCR technology. The results showed that VPA promoted the expression of the endogenous gene c-Myc and inhibited cell proliferation; at the same time, it promoted the expression of VEGF and other genes related to angiogenesis. @*Conclusions@#When VPA is added to the culture medium, only the cells that have begun to reprogram can break the G2/M repression through the expression of the endogenous gene c-Myc, and use the nutrients and space in the culture dish to proliferate normally, which can achieve the purpose of directly improving the efficiency of reprogramming.Another new discovery for Bactrian camels, VPA significantly increased the expression of VEGFC and other genes, promoting the transformation of fibroblasts to endothelial cells (different from the mesenchymal-to-epithelial transition process of other species) to accelerate the early induction of Bactrian camels iPSc process. Overall, this study proved the new mechanism of VPA in enhancing the induction of pluripotency from the transcriptome level.
ABSTRACT
Background and Objectives@#Induced pluripotent stem cells (iPSCs) are usually generated by reprogramming differentiated cells through the introduction of specific transcription factors, but this is a difficult and inefficient process.Valproic acid (VPA) is a histone deacetylase inhibitor that significantly improves the efficiency of iPSC generation.But its role and mechanism are still unclear. @*Methods@#and Results: We transduced Bactrian camel fetal fibroblasts (BCFFs) with retroviruses carrying defined factors (OCT4, SOX2, KLF4, c-MYC and EGFP; OSKMG) in the presence of VPA. Cells were collected (Day 7) and analyzed using RNA-seq technology. Afterwards, different groups of cells and transcriptomics results were detected by PCR and qRT-PCR technology. The results showed that VPA promoted the expression of the endogenous gene c-Myc and inhibited cell proliferation; at the same time, it promoted the expression of VEGF and other genes related to angiogenesis. @*Conclusions@#When VPA is added to the culture medium, only the cells that have begun to reprogram can break the G2/M repression through the expression of the endogenous gene c-Myc, and use the nutrients and space in the culture dish to proliferate normally, which can achieve the purpose of directly improving the efficiency of reprogramming.Another new discovery for Bactrian camels, VPA significantly increased the expression of VEGFC and other genes, promoting the transformation of fibroblasts to endothelial cells (different from the mesenchymal-to-epithelial transition process of other species) to accelerate the early induction of Bactrian camels iPSc process. Overall, this study proved the new mechanism of VPA in enhancing the induction of pluripotency from the transcriptome level.
ABSTRACT
BACKGROUND:Although there is a certain progress in the preparation of tissue-engineered bone tissue using a variety of materials, some deficiencies have appeared such as mismatching between scaffold degradation rate and new bone formation rate, slow tissue growth, toxic metabolites. OBJECTIVE:To build a new type of inducible bone repair composite scaffold with bionic bone structurematerials and to evaluate its physicochemical and biological properties. METHODS: Icarin encapsulated by chitosan was used to prepare drug-loaded microspheres, and the drug release rate of the microspheres was detected. Chitosan microspheres were mixed with colagen to build the core part of scaffold materials. Hydroxyapatite (HA), polycaprolactone (PCL) and colagen were mixed in hexafluoride isopropanol (HFIP) to prepare the HA/PCL/colagen outer part of composite scaffold material at the rate of 0:3:3, 1:3:3, 2:3:3, 3:3:3. Each proportional electrospinning was used for one layer, and finaly the 4-layer outer tube of the scaffold was produced. The tube core and outer tube were crosslinked by 1% genipin. Universal material testing machine, surface contact angle meter, infrared spectroscopy, scanning electron microscope, water absorption, permeability, porosity,in vitro degradation tests for cross-linked and uncross-linked were used to observe the structure and characteristics of tubular materials. Bone marrow mesenchymal stem cels were seeded on the surface of cross-linked and uncross-linked bone repair materials to evaluate the biocompatibility of the scaffolds. Cross-linked and uncross-linked bone repair materials were implanted subcutaneously into Wistar rats to evaluate the histocompatibility of the scaffolds. RESULTS AND CONCLUSION:The drug in the scaffold had a suitable release; the bone scaffold material had good uniformity, and cross-linked scaffolds materials had better mechanical properties, water absorption and permeability than the uncross-linked(P < 0.05). The degradation rate of the cross-linked group was significantly lower than that of the uncross-linked group (P< 0.05). Hematoxylin-eosin staining showed that the bone marrow mesenchymal stem cels could adhere wel to the cross-linked and uncross-linked materials. No inflammatory reactions occurred after subcutaneous implantation of cross-linked and uncross-linked materials. These findings indicate that the cross-linked scaffold for inducible bone tissue engineering has good biocompatibility and mechanical properties.
ABSTRACT
Focal adhesion kinase is a non-receptor protein tyrosine kinase with molecular weight 125 ku and regarded as the foundmental molecule of integrin-dependent signal transduction pathway. Active focal adhesion kinase regulates cell adhesion, migration, proliferation and differentiation by interacting with Src family kinase, phosphatidylinositol-3 kinase, cytoskeletal proteins, Graf and adoptor proteins through the phosphorylated tyrosines and the proline-rich sequences.