Differentiation of insulin-producing cells from human umbilical cord mesenchymal stem cells infected by MAFA-PDX1 overexpressed lentivirus / 中国组织工程研究

BACKGROUND:Transplantation of stem cell-derived islet β cells has been considered effective for the treatment of type 1 diabetes.Human umbilical cord mesenchymal stem cell is an ideal cellular source,but with a low differentiation efficiency to islet β cells. OBJECTIVE:To explore the possibility of human umbilical cord mesenchymal stem cells modified by MAFA and PDX1 to differentiate into insulin-producing cells. METHODS:MAFA-PDX1 lentivirus expression vectors were constructed.The efficiency and potentiality of human umbilical cord mesenchymal stem cells differentiated into insulin-producing cells with three methods were compared by cell morphology,RT-qPCR,and dithizone staining[protocol A:Simple lentivirus group;protocol B:Drug(nicotinamide β-mercaptoethanol)induction followed by lentivirus group;protocol C:lentivirus and drug induction group]. RESULTS AND CONCLUSION:(1)Morphological change of cells:Cell morphology was all altered after the induction of three protocols.At day 11,human umbilical cord mesenchymal stem cells induced by protocol B showed the most cell clusters among the three protocols,appearing aggregated islet-like cell clusters.(2)Islet-related gene expression detected by RT-qPCR:Horizontal comparison of the three protocols at the same induction time point showed that the expression levels of MAFA and PDX1 genes were the highest in protocol C on day 5 of induction,and those in protocol B were the highest on day 11 of induction.Human umbilical cord mesenchymal stem cells induced by protocol B had the greatest expression of GCG gene at day 5,INS and GLUT2 genes at day 11.(3)Dithizone staining to identify zinc ions:parts of the post-induced cells were stained brownish red by dithizone on day 11.The partial small island cells were stained brownish red with a darker color(positive expression)in protocol B.(4)It is concluded that the overexpression of MAFA and PDX1 can promote the differentiation of human umbilical cord mesenchymal stem cells into insulin-producing cells.The combination of MAFA-PDX1 gene modification and drug induction is superior to the single gene modification.

Construction of human interleukin-26 lentivirus expression plasmid and gene knockout plasmid and their activity verification in HEK293T cells / 中国生物制品学杂志

@#Objective To construct a lentivirus-based expression plasmid and gene knockout plasmid of human interleukin(IL)-26 so as to lay a foundation of studying the function of IL-26 gene in cell signaling pathway and autophagy.Methods IL-26 gene sequence was amplified from human peripheral blood mononuclear cells by RT-PCR and cloned into pCDH-CMVMCS-EF1-copGFP eukaryotic expression vector to construct overexpression plasmid;Four knockout targets,Exon1sgRNA1,Exon1sgRNA2,Exon3sgRNA1 and Exon3sgRNA2,were designed based on the exon sequence of IL-26,and constructed into lentiCRISPRv2 vector by CRISPR/Cas9 technology to construct gene knockout plasmid. The overexpression plasmid and gene knockout plasmid were transiently transfected into HEK293T cells respectively,and the expression of IL-26 was verified by RT-qPCR and Western blot. In addition,amino acid sequence analysis,structure prediction and subcellular localization observation of IL-26 were performed.Results The results of restriction digestion,sequencing and bioinformatics analysis showed that IL-26 was 516 bp in length,encoding 171 amino acids. The IL-26 mRNA level and protein level of HEK293T cells transfected with IL-26 overexpression plasmid increased by 656. 789 times and 1. 978 times respectively with significant differences as compared with the normal control group(t = 17. 976 and 7. 859,P < 0. 000 1 and < 0. 001,respectively). With the transfection of 4 knockout targets Exon1sgRNA1,Exon1sgRNA2,Exon3sgRNA1 and Exon3sg-RNA2 into HEK293T cells,the expression of IL-26 decreased by 0. 930,0. 980,0. 523 3 and 0. 316 9 times,respectively,among which Exon3sgRNA2 significantly down-regulated the expression of IL-26(t = 7. 440,P < 0. 001). IL-26protein showed signal peptide structure and certain transmembrane function in the first 22 amino acids,which existed in cytoplasm.Conclusion IL-26overexpression and gene knockout plasmids were successfully constructed,which laid a foundation of the follow-up study of the function of IL-26.

The construction and application of lentiviral overexpression vector of goat miR-204 in testis.

The miRNA gene in DNA is first transcribed to Pri-miRNA, and then processed to Pre-miRNA, a stem-loop RNA segment (precursor) and further to miRNA which binds to mRNA by Dicer protein complex. It was confirmed that goat miR-204 could regulate the expressions of Sirt1 and the SSCs' (Spermatogonial Stem Cells) important genes Oct4 and Plzf, and inhibit the proliferation of dairy goat SSCs in vitro in our previous work. So, the research in vivo was needed next. In this study, the recombinant lentivirus vector pCDH-CMV-mir204-EF1-GreenPuro containing a goat chi-pri-mir-204 gene DNA segment was structured, and transfected into 293 T cells for packaged lentivirus, which then were injected into mouse seminiferous tubules. After 7 days, the goat miR-204 and the related genes such as Sirt1 and Plzf were detected in the mouse testis. This work laid a good foundation for further study of miR-204 biological function in vivo.

[Construction of an oral squamous cell carcinoma cell line for stable PA28γ overexpression].

OBJECTIVE: To construct a PA28γ overexpression cell line and determine its effects after infecting an oral squa-mous cell carcinoma (OSCC) cell line. METHODS: The PA28γ gene was cloned into the pLOV.CMV.cherry.2A.EF1a.PuroR lentiviral vector by polymerase chain reaction (PCR), and PCR and DNA sequencing alignment analysis were used for identification. Then, 293T cells were used to package viral diseases. Infected OSCC cells were used to construct a cell line with stable PA28γ overexpression. Finally, the level of PA28γ expression in the OSCC cell line was detected through Western blot. RESULTS: The successful construction of PA28γ recombinant lentiviral vectors was confirmed by DNA sequencing. The results of immunofluorescence showed that the PA28γ overexpression lentivirus successfully infected the OSCC cells and showed cherry red fluorescence. The results of Western blot demonstrated that the constructed cells with stable PA28γ overexpression significantly increased the expression of PA28γ. CONCLUSIONS: The PA28γ overexpression lentiviral vector can significantly increase its protein expression in OSCC cells. We provide a stable OSCC cell line for further study on the effect of PA28γ in OSCC.

Construction of an oral squamous cell carcinoma cell line for stable PA28γ overexpression / 华西口腔医学杂志

OBJECTIVE@#To construct a PA28γ overexpression cell line and determine its effects after infecting an oral squa-mous cell carcinoma (OSCC) cell line.@*METHODS@#The PA28γ gene was cloned into the pLOV.CMV.cherry.2A.EF1a.PuroR lentiviral vector by polymerase chain reaction (PCR), and PCR and DNA sequencing alignment analysis were used for identification. Then, 293T cells were used to package viral diseases. Infected OSCC cells were used to construct a cell line with stable PA28γ overexpression. Finally, the level of PA28γ expression in the OSCC cell line was detected through Western blot.@*RESULTS@#The successful construction of PA28γ recombinant lentiviral vectors was confirmed by DNA sequencing. The results of immunofluorescence showed that the PA28γ overexpression lentivirus successfully infected the OSCC cells and showed cherry red fluorescence. The results of Western blot demonstrated that the constructed cells with stable PA28γ overexpression significantly increased the expression of PA28γ.@*CONCLUSIONS@#The PA28γ overexpression lentiviral vector can significantly increase its protein expression in OSCC cells. We provide a stable OSCC cell line for further study on the effect of PA28γ in OSCC.

[Construction of miR-331-3p overexpression vector and its effect on cell proliferation].

To investigate the effect of miR-331-3p on the proliferation of porcine renal epithelial cells (PK15) and its mechanism, the pcDNA 3.1(+) overexpression vector of miRNA-331-3p (pcDNA 3.1(+)-miR-331-3p) was constructed. PK15 cells were divided into four groups, including experimental group, experimental control group, inhibitor group and inhibitor control group. Experimental group and experimental control group were transfected with pcDNA 3.1(+)-miR-331-3p and pcDNA 3.1(+), respectively. Inhibitor group and inhibitor control group were transfected with miR-331-3p inhibitor and miR-331-3p negative control (miR-331-3p NC), respectively. Above all, CCK-8 reagent was used to plot the cell proliferation curve and Propidium (PI) staining was used to detect the proportion of cell stages. Secondly, its expression change were detected by quantitative real-time PCR that included the growth inhibitory protein family member 5 (ING5), cyclin-dependent kinase 2 (CDK2), cyclin-dependent kinase 3 (CDK3), cyclin-dependent kinase 4 (CDK4), Cyclin B and cyclin-dependent kinase inhibitor 1A (CDKN1A). The results showed that the expression of miRNA-331-3p was significantly increased in the experimental group. The cell proliferation curve showed that the number of cells in experimental group was significantly higher than that in experimental control group or inhibitor control group at 48 h and 72 h (P<0.05). Simultaneously, Inhibitor group was significantly lower than experimental control group or inhibitor control group in the number of cells at 48 h and 72 h (P<0.05), but there was no significant difference between the experimental group and the control group. Compared with the experimental control group, the proportion of cells of experimental group in G0/G1 phase decreased, the proportion of S phase and G2/M phase increased, and the inhibitor control group showed the opposite trend. Simultaneously, the expression levels of CDK2, CDK3, CDK4 and Cyclin B genes in the experimental group were significantly increased, while ING5 and CDKN1A genes inhibiting proliferation showed a significant downward trend. These results demonstrate that the miR-331-3p overexpression vector was successfully constructed, and miR-331-3p has the ability to promote the proliferation of PK15 cells. The study lays a solid foundation for further research for its role in pig growth and development.

Construction of miR-331-3p overexpression vector and its effect on cell proliferation / 生物工程学报

To investigate the effect of miR-331-3p on the proliferation of porcine renal epithelial cells (PK15) and its mechanism, the pcDNA 3.1(+) overexpression vector of miRNA-331-3p (pcDNA 3.1(+)-miR-331-3p) was constructed. PK15 cells were divided into four groups, including experimental group, experimental control group, inhibitor group and inhibitor control group. Experimental group and experimental control group were transfected with pcDNA 3.1(+)-miR-331-3p and pcDNA 3.1(+), respectively. Inhibitor group and inhibitor control group were transfected with miR-331-3p inhibitor and miR-331-3p negative control (miR-331-3p NC), respectively. Above all, CCK-8 reagent was used to plot the cell proliferation curve and Propidium (PI) staining was used to detect the proportion of cell stages. Secondly, its expression change were detected by quantitative real-time PCR that included the growth inhibitory protein family member 5 (ING5), cyclin-dependent kinase 2 (CDK2), cyclin-dependent kinase 3 (CDK3), cyclin-dependent kinase 4 (CDK4), Cyclin B and cyclin-dependent kinase inhibitor 1A (CDKN1A). The results showed that the expression of miRNA-331-3p was significantly increased in the experimental group. The cell proliferation curve showed that the number of cells in experimental group was significantly higher than that in experimental control group or inhibitor control group at 48 h and 72 h (P<0.05). Simultaneously, Inhibitor group was significantly lower than experimental control group or inhibitor control group in the number of cells at 48 h and 72 h (P<0.05), but there was no significant difference between the experimental group and the control group. Compared with the experimental control group, the proportion of cells of experimental group in G0/G1 phase decreased, the proportion of S phase and G2/M phase increased, and the inhibitor control group showed the opposite trend. Simultaneously, the expression levels of CDK2, CDK3, CDK4 and Cyclin B genes in the experimental group were significantly increased, while ING5 and CDKN1A genes inhibiting proliferation showed a significant downward trend. These results demonstrate that the miR-331-3p overexpression vector was successfully constructed, and miR-331-3p has the ability to promote the proliferation of PK15 cells. The study lays a solid foundation for further research for its role in pig growth and development.

Characterization analysis and overexpressed vector construction of the circular RNA hsa_circ_0082626 derived from the antiviral gene ZC3HAV1 / 医学研究生学报

Objective Circular RNA is a research hotspot of non-coding RNAs. The purpose of this study was to investigate the basic characteristics and expression effect of the overexpression vectors of circular RNA hsa_circ_0082626 transcribed from antiviral gene ZC3HAV1. Methods The basic characteristics of hsa_circ_0082626 were studied by the verification of reverse cleavage site, RNase digestion assay and intracellular distribution location with extraction of cytoplasmic and nuclear RNA. In the RNase digestion assay, samples were divided into RNase R treatment group and control group. RNase. 20 U (2 U/μg) of RNase R was added to the R treatment group, and the control group was replaced with an equivalent amount of ddH2O to detect changes in expression levels after RNase treatment. The cells were divided into 2 groups: overexpression group and negative control group. At 24, 48 and 72 h after transfection, cells were collected to detect the expression of circular RNA by RT-qPCR. Results Compared with the control group, the expression of ZC3HAV1, CDR1as and GAPDH in the RNase R treatment group was increased (0.144±0.002 vs 1.000±0.016, 0.772±0.058 vs 1.000±0.122, 0.077±0.009 vs 1.000±0.164, P<0.05). Hsa_circ_0082626 could resist the treatment of RNase R and was mainly distributed in cytoplasm. The expression level of hsa_circ_0082626 in the overexpression group was significantly higher than that in the negative control group, and the expression level was the highest at 48 h after transfection. Conclusion The characteristics of hsa_circ_0082626 reverse cleavage site, RNase resistance and expression in cells were successfully analyzed, which proved that hsa_circ_0082626 does have a circular structure. The overexpression vector of hsa_circ_0082626 was successfully constructed to provide an experimental basis for the biological function and mechanism of RNA hsa_circ_0082626.

The novel protein C3orf43 accelerates hepatocyte proliferation.

BACKGROUND: Our previous study found that single-pass membrane protein with coiled-coil domains 1 (C3orf43; XM_006248472.3) was significantly upregulated in the proliferative phase during liver regeneration. This indicates that C3orf43 plays a vital role in liver cell proliferation. However, its physiological functions remains unclear. METHODS: The expressions of C3orf43 in BRL-3A cells transfected with C3orf43-siRNA (C3-siRNA) or overexpressing the vector plasmid pCDH-C3orf43 (pCDH-C3) were measured via RT-qPCR and western blot. Cell growth and proliferation were determined using MTT and flow cytometry. Cell proliferation-related gene expression was measured using RT-qPCR and western blot. RESULTS: It was found that upregulation of C3orf43 by pCDH-C3 promoted hepatocyte proliferation, and inhibition of C3orf43 by C3-siRNA led to the reduction of cell proliferation. The results of qRT-PCR and western blot assay showed that the C3-siRNA group downregulated the expression of cell proliferation-related genes like JUN, MYC, CCND1 and CCNA2, and the pCDH-C3 group upregulated the expression of those genes. CONCLUSION: These findings reveal that C3orf43 may contribute to hepatocyte proliferation and may have the potential to promote liver repair and regeneration.

Effect of Smad3 on cell migration of A549 and HeLa cells / 中国比较医学杂志

Objective To investigate the effect of Smad3 on cell migration of A549 and HeLa cells.Methods Primers for pCMV-Myc-Smad3 plasmid construction and siRNA targeting Smad 3 were designed and synthesized .pCMV-Myc-Smad3 plasmid was constructed with molecular cloning techniques .Overexpression of Smad 3 with Myc-tag or silencing of endogenous Smad3, and then scratch assay was used to detect the migration ability of A 549 and HeLa cells in vitro. Results pCMV-Myc-Smad3 plasmid was successfully constructed .Overexpression of Smad 3 significantly up-regulated the migration rate of A549 and HeLa cells.Conversely, in the same cells, silencing of endogenous Smad3 or treatment with Smad3 inhibitor, SIS3, down-regulated the migration rate .Conclusions Smad3 promotes cell migration of A549 and HeLa cells.

Pancreatic Beta Cell Survival and Signaling Pathways: Effects of Type 1 Diabetes-Associated Genetic Variants.

Type 1 diabetes (T1D) is a complex autoimmune disease in which pancreatic beta cells are specifically destroyed by the immune system. The disease has an important genetic component and more than 50 loci across the genome have been associated with risk of developing T1D. The molecular mechanisms by which these putative T1D candidate genes modulate disease risk, however, remain poorly characterized and little is known about their effects in pancreatic beta cells. Functional studies in in vitro models of pancreatic beta cells, based on techniques to inhibit or overexpress T1D candidate genes, allow the functional characterization of several T1D candidate genes. This requires a multistage procedure comprising two major steps, namely accurate selection of genes of potential interest and then in vitro and/or in vivo mechanistic approaches to characterize their role in pancreatic beta cell dysfunction and death in T1D. This chapter details the methods and settings used by our groups to characterize the role of T1D candidate genes on pancreatic beta cell survival and signaling pathways, with particular focus on potentially relevant pathways in the pathogenesis of T1D, i.e., inflammation and innate immune responses, apoptosis, beta cell metabolism and function.

Expression vectors for C-terminal fusions with fluorescent proteins and epitope tags in Candida glabrata.

Candida glabrata is a haploid yeast considered the second most common of the Candida species found in nosocomial infections, accounting for approximately 18% of candidemias worldwide. Even though molecular biology methods are easily adapted to study this organism, there are not enough vectors that will allow probing the transcriptional and translational activity of any gene of interest in C. glabrata. In this work we have generated a set of expression vectors to systematically tag any gene of interest at the carboxy-terminus with three different fluorophores (CFP, YFP and mCherry) or three epitopes (HA, FLAG or cMyc) independently. This system offers the possibility to generate translational fusions in three versions: under the gene's own promoter integrated in its native locus in genome, on a replicative plasmid under its own promoter, or on a replicative plasmid under a strong promoter to overexpress the fusions. The expression of these translational fusions will allow determining the transcriptional and translational activity of the gene of interest as well as the intracellular localization of the protein. We have tested these expression vectors with two biosynthetic genes, HIS3 and TRP1. We detected fluorescence under the microscope and we were able to immunodetect the fusions using the three different versions of the system. These vectors permit coexpression of several different fusions simultaneously in the same cell, which will allow determining protein-protein and protein-DNA interactions. This set of vectors adds a new toolbox to study expression and protein interactions in the fungal pathogen C. glabrata.

Molecular cloning, sequence analysis, and construction of expression vector of monofunction feedback inhibition sensitive CtAK1 gene in Carthamus tinctorius / 中草药

Objective: To separate the full length cDNA of gene encoding the key enzyme AK in aspartate metabolic pathways of Carthamus tinctorius and to construct plant overexpression vector. Methods: According to annotation on transcriptome library of C. tinctorius and core fragments and expression analysis data of CtAK identified by qRT-PCR, we separated the full length cDNA of AK gene of C. tinctorius (CtAK) using RACE technology and constructed plant expression vector using recombinant DNA technology. Results: Bioinformatics analysis showed the full length CtAK was 1 703 bp and ORF area was 1 626 bp, encoding 541 amino acid residues. The function structure domain analysis showed the gene might be a monofunction feedback inhibition sensitive AK1 from plant. We successfully constructed plant expression vector pCAMBIA3301-CTP-AK1 which contained 35 S promoter and Bar resistance genes and chloroplast transit peptide by recombinant DNA technology. Conclusion: The gene encoding CtAK1 is obtained and the plant overexpression vector is constructed, which lays the foundation for researching on biological function and mechanism of action in amino acid metabolism regulation of C. tinctorius.