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BACKGROUND:SMAD family member 4(SMAD4)can promote bone remodeling in osteoporotic rats,but it is unclear whether SMAD4 interferes with the expression of iron metabolism related proteins in osteoporotic rats. OBJECTIVE:To explore the effect of SMAD4 overexpression on the expression of iron metabolism related proteins in osteoporotic rats. METHODS:Rats were randomized into sham group,ovariectomy group,transfection control group and SMAD4 overexpression group.Animal models of osteoporosis were established in the latter three groups by ovariectomy,and only adipose tissue was removed in the sham group.One week later,adenovirus was injected into the femoral bone marrow cavity.SMAD4 overexpression group and transfection control group were injected with adenovirus overexpressing SMAD4 gene and control empty virus,respectively.Index detection was performed at 1 month after injection.Micro-CT,hematoxylin-eosin staining and tartrate resistant acid phosphatase staining were used to detect bone formation and bone resorption in osteoporotic rats.ELISA was used to detect serum ferritin and hepcidin levels.Immunohistochemical staining was used to detect alkaline phosphatase,osteocalcin,receptor activator for nuclear factor-κB ligand and tartrate resistant acid phosphatase levels in femoral tissue.RT-qPCR was used to detect SMAD4,hepcidin,divalent metal transporter 1,transferrin receptor1 and ferroportin1 mRNA levels in femoral tissue.Western blot was used to detect SMAD4,alkaline phosphatase,osteocalcin,osteoprotegerin,receptor activator for nuclear factor-κB ligand,tartrate resistant acid phosphatase,β-Crosslaps,hepcidin,divalent metal transporter 1,transferrin receptor 1,and ferroportin 1 protein levels. RESULTS AND CONCLUSION:In the sham group,bone trabeculae in femur tissue were intact,and almost no osteoclasts were found.In the ovariectomy and transfection control groups,the bone trabeculae were sparse and a large number of osteoclasts were present.In the SMAD4 overexpression group,the number of bone trabeculae was increased and the number of osteoclasts was decreased.Compared with the sham group,the ovariectomy group showed a significant reduction in the protein expression of SMAD4,alkaline phosphatase,osteocalcin,and osteoprotegerin in femoral tissue and hepcidin levels in serum and femoral tissue,while receptor activator for nuclear factor-κB ligand,tartrate resistant acid phosphatase,β-Crosslaps protein levels,divalent metal transporter 1,transferrin receptor1,ferroportin1 mRNA and protein levels were significantly increased(P＜0.05).Compared with the transfection control group,the SMAD4 overexpression showed a significant increase in SMAD4,alkaline phosphatase,osteocalcin,and osteoprotegerin protein levels in femoral tissue and hepcidin levels in serum and femoral tissue,while the expressions of receptor activator for nuclear factor-κB ligand,tartrate resistant acid phosphatase,β-Crosslaps protein levels,divalent metal transporter 1,transferrin receptor1,and ferroportin 1 at mRNA and protein levels were significantly decreased(P＜0.05).To conclude,overexpression of SMAD4 promotes bone remodeling in osteoporotic rats by interfering with the expression of iron metabolism related proteins.
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BACKGROUND:Previous studies have shown that puerarin can inhibit the differentiation of osteoclasts,and the expression of Notch signaling pathway-related proteins such as Notch1,HES1,and Jagged1 is decreased.However,the specific mechanism of the Notch1 signaling pathway for the inhibition of osteoclast differentiation by puerarin is not clear. OBJECTIVE:To explore the effect of Notch signaling pathway on puerarin inhibiting the differentiation of mouse macrophage Raw264.7 into osteoclasts. METHODS:Raw264.7 cells were divided into seven groups for intervention culture.Blank control group was cultured in high-sugar DMEM medium;the osteoclast induction group was cultured in osteoclast induction medium;the puerarin intervention group was cultured with 50 μmol/L puerarin at the same time of osteoclast induction;Notch1 siRNA control group,Notch1 siRNA group,Notch1 overexpression control group and Notch1 overexpression group were transfected with Notch1 siRNA control sequence,Notch1 siRNA,Notch1 overexpression control plasmid and Notch1 overexpression plasmid,respectively,and then cultured with osteoclast induction medium and puerarin.The number and size of osteoclasts were observed by tartrate-resistant acid phosphatase staining,the skeleton formation of osteoclasts was observed by F-actin staining,and the gene expression level of osteoclast formation markers was detected by RT-PCR. RESULTS AND CONCLUSION:Tartrate-resistant acid phosphatase staining results showed that puerarin intervention could inhibit the generation of osteoclasts,Notch1 silencing could further reduce the number of osteoclasts,while the number of osteoclasts in the osteoclast-induced group increased significantly after Notch1 overexpression.The results of F-actin showed that Raw264.7 cells could form a well-defined F-actin ring after osteoclast induction.Puerarin intervention would inhibit the formation of cytoskeleton,and Notch1 silencing could aggravate the inhibitory effect of cytoskeleton formation,while Notch1 overexpression could alleviate this inhibitory effect of puerarin.RT-PCR results showed that puerarin could inhibit the mRNA expression levels of tartrate-resistant acid phosphatase,Cathepsin K and c-Fos,the expression of the above-mentioned three factors decreased significantly after Notch1 gene silencing,and Notch1 overexpression could upregulate the expression of these factors.These finding indicate that puerarin inhibits the differentiation of Raw264.7 cells into osteoclasts through the Notch signaling pathway.
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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.
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Objective To generate mice with whole-body overexpression of human METRNL gene. Methods Based on Cre-loxP system, Dppa3-Cre mice were mated with Rosa26-LSL-METRNL knock-in mice（R26-LSL-METRNL+/-）to generate R26-L-METRNL+/- mice. The genotypes of the offsprings were identified, and tissues of the blood, heart, liver, spleen, lung, kidney, brain, white adipose and muscle were collected. The expression of human METRNL gene in mice was investigated by quantitative real-time PCR, western blot and enzyme linked immunosorbent assay. Results Compared with wild type control mice, human METRNL in R26-L-METRNL+/- mice significantly expressed at both mRNA and protein levels in tissues, with abundant METRNL protein in blood. Conclusion The mouse model overexpressing human METRNL gene（R26-L-METRNL+/- mouse）was successfully constructed.
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Modulating Tankyrases (TNKS), interactions with USP25 to promote TNKS degradation, rather than inhibiting their enzymatic activities, is emerging as an alternative/specific approach to inhibit the Wnt/β-catenin pathway. Here, we identified UAT-B, a novel neoantimycin analog isolated from Streptomyces conglobatus, as a small-molecule inhibitor of TNKS-USP25 protein-protein interaction (PPI) to overcome multi-drug resistance in colorectal cancer (CRC). The disruption of TNKS-USP25 complex formation by UAT-B led to a significant decrease in TNKS levels, triggering cell apoptosis through modulation of the Wnt/β-catenin pathway. Importantly, UAT-B successfully inhibited the CRC cells growth that harbored high TNKS levels, as demonstrated in various in vitro and in vivo studies utilizing cell line-based and patient-derived xenografts, as well as APCmin/+ spontaneous CRC models. Collectively, these findings suggest that targeting the TNKS-USP25 PPI using a small-molecule inhibitor represents a compelling therapeutic strategy for CRC treatment, and UAT-B emerges as a promising candidate for further preclinical and clinical investigations.
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@#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.
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Aim To investigate the effect of overexpression of silent information regulator 1 (Sirtl) on cardiac function in mice with myocardial ischemia. Methods Myocardial specific Sirtl overexpression transgenic mice (Sirtl-Tg) and littermate control mice (C57BL/6J), half male and half female, were randomly divided into control sham operation group (Con), control model group (Con +ISO), Sirtl overexpression sham operation group (Sirtl-Tg) and Sirtl overexpression model group (Sirtl-Tg + ISO). Isoproterenol (ISO) was injected subcutaneously into the back of the neck at 100 mg • kg
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Current studies have shown that centromere protein F (CENPF) was overexpressed in hepatocellular carcinoma (HCC) and might be involved in the pathogenesis of HCC. Specifically, due to the very large molecular weight (358 kDa) of CENPF full length protein, only CENPF knock-down, but not overexpression models, were applied currently to explore the carcinogenicity of CENPF in HCC. Whether CENPF overexpression is a cause or an effect in HCC remains to be illustrated. We aimed to establish a CENPF overexpression cell model using CRISPR/dCas9 synergistic activation mediator (SAM) system with lentiMPHv2 and lentiSAMv2 vectors to explore the role of CENPF overexpression in HCC. Single guide RNAs (sgRNAs) that specifically identify the transcription initiation site of CENPF gene were synthesized and inserted into the lentiSAMv2 plasmid. Huh-7 and HCCLM3 cells were first transduced with lentiMPHv2 and then selected with hygromycin B. The cells were then transduced with lentiSAMv2 carrying specific sgRNA for CENPF gene, followed by blasticidin S selection. The mRNA and protein detection results of Huh-7 and HCCLM3 cells screened by hygromycin B and blasticidin S showed that the endogenous overexpression of CENPF can be induced by sgRNA1 and sgRNA4, especially by sgRNA4. By using the CRISPR/dCas9 technique, stable cell models with overexpressed CENPF were successfully constructed to explore the role of CENPF in tumorigenesis, which provides a reference for the construction of cell models overexpressing large molecular weight protein.
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Humanos , Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , ARN Guía de Sistemas CRISPR-Cas , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Higromicina BRESUMEN
Abstract The present study investigated the effects of valerian methanolic extract and valerenic acid on the expression of LL-37 gene and protein in A549 and MRC5 line cells. After preparing Valerian seeds, sowing them in March 2020, and harvesting the rhizome in October 2020, the extract was prepared from the valerian rhizome by maceration method. Valerian acid content was determined using high performance liquid chromatography (HPLC). Two cell lines (A549 and MRC-5) were used to study the effects of valerian extract, and the MTT test was used to evaluate cell viability. The expression of LL-37 mRNA and protein was assessed by Real-Time PCR and western blot, respectively. In vivo safety assessments and histopathological analysis were also conducted. Data was analyzed by Graphpad Prism 8 software. Valerian methanolic extract and valerenic acid upregulated the LL-37 mRNA and protein expression in both treated cell lines. Valerenic acid showed a greater effect on upregulating LL-37 expression than valerian methanolic extract. A549 cells were more sensitive to valerian methanolic extract compared to MRC5 cells, and its cell viability was reduced. Furthermore, liver and kidney-related safety assessments showed that valerian methanolic extract had no toxic effects. In general, it was concluded that the methanolic extract of valerian as well as the resulting valerenic acid as the most important component of the extract has the ability to upregulate LL-37expression. Therefore, methanolic extract of valerian and valerenic acid can be considered for improving the immune system.
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Valeriana/efectos adversos , Extractos Vegetales/efectos adversos , Catelicidinas/efectos adversos , Western Blotting/instrumentación , Cromatografía Líquida de Alta Presión/métodos , Péptidos Catiónicos Antimicrobianos/agonistas , Células A549/clasificación , Genes/genética , Hígado/anomalíasRESUMEN
(3S)-Linalool synthase (LIS) is a key enzyme involved in the monoterpene biosynthetic pathway. Based on our previous transcriptome study, the expression level of LIS gene was exceedingly related to glycyrrhizic acid (GA) biosynthesis. Therefore, we used hairy root culturing to further investigate the effect of LIS on the GA biosynthesis. A LIS gene (GenBank accession number: MZ169552) was cloned from Glycyrrhiza uralensis. The plant binary overexpression vector pCA-LIS was constructed by gene fusion. G. uralensis hairy roots overexpressing LIS were induced by the Agrobacterium rhizogenes ATCC15834. The expression levels of LIS were analyzed by real-time quantitative PCR (RT-qPCR) and the contents of GA in hairy root lines were determined by UPLC. It was found that in the hairy root lines overexpressing LIS, the expression levels of LIS were significantly higher than that in the wild type, while the contents of GA were remarkably lower than those in the wild type and negative control. These findings indicate that the expression level of LIS is negatively correlated with the accumulation of GA. In this study, LIS was cloned from G. uralensis for the first time and the negative regulatory effect of LIS on GA biosynthesis was confirmed by reverse genetics. This work provides support for further improvement of the molecular regulatory network of GA biosynthesis in G. uralensis.
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OBJECTIVE@#To construct a HEK293 cell line stably overexpressing TrxR1 as a cell model for functional study of TrxR1 and screening of TrxR1-targeting drugs.@*METHODS@#TrxR1 gene was amplified by PCR and ligated with the lentivirus expression vector pLVX-Puro, which was transformed into Escherichia coli and identified by Sanger dideoxy sequencing. HEK293 cells were infected with the recombinant lentivirus vector (pLVX-Puro-TXNRD1) and screened with Puromycin for cell clones with stable TrxR1 overexpression (HEK293-TrxR1-OE cells). HEK293-TrxR1-OE cells, along with HEK293 cells infected with pLVX-Puro vector (HEK293-NC) and normal HEK293 cells, were tested for mRNA and protein expression levels of TrxR1 using RT-qPCR and Western blotting. TrxR1 enzyme activity in the cells was evaluated with insulin endpoint assay and TRFS-green probe imaging. The sensitivity of the cells to auranofin, a specific TrxR1 inhibitor, was determined with CCK8 assay.@*RESULTS@#TrxR1 gene was successfully inserted into the lentiviral vector pLVX-Puro as confirmed by DNA sequencing. The enzyme activity and mRNA and protein expression levels of TrxR1 were significantly higher in HEK293-TrxR1-OE cells than in HEK293 and HEK293-NC cells (P < 0.005). The inhibitory effects of auranofin on proliferation and cellular TrxR1 enzyme activity were significantly attenuated in HEK293-TrxR1-OE cells as compared with HEK293 and HEK293-NC cells (P < 0.005).@*CONCLUSION@#We successfully obtained a HEK293 cell line with stable TrxR1 overexpression, which shows resistance to auranofin and can be used for screening TrxR1 targeting drugs.
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Humanos , Auranofina , Línea Celular Tumoral , Vectores Genéticos , Células HEK293 , Lentivirus/genética , ARN Mensajero , TransfecciónRESUMEN
Objective To study the effect and mechanism of epigallocatechol gallate (EGCG) combined with trastuzu-mab on the proliferation of human epidermal growth factor receptor 2 (HER2) overexpressing breast cancer cells. Methods Trastuzumab was expressed and purified. The cell proliferation of HER2 overexpressing breast cancer cells BT474 and SK-BR-3 treated with trastuzumab, EGCG, or trastuzumab plus EGCG was evaluated by CCK8 assay. The effects of EGCG and trastuzumab on the expression of HER2, epidermal growth factor receptor (EGFR), mitogen-activated protein kinase (MAPK), protein kinase B (Akt), and their phosphorylated proteins in BT474 breast cancer cells were detected by Western blot. Results The results of cell proliferation assay indicated that EGCG and trastuzumab, alone or in combination, effectively inhibited the proliferation of BT-474 and SK-BR-3 cells. And within a certain concentration range, EGCG and trastuzumab showed a synergistic proliferation inhibitory effect on HER2 overexpressing breast cancer cells. Consistent with these results, Western blot results showed that trastuzumab and EGCG, alone or in combination significantly reduced the phosphorylation levels of Akt, MAPK, EGFR, and HER2 in BT474 cells. Moreover, the inhibition effect of EGCG plus trastuzumab was significantly more potent than either EGCG or trastuzumab. Conclusion EGCG and trastuzumab could synergistically inhibit the proliferation of HER2 overexpressing breast cancer cells, which may be related to the regulation of Akt and MAPK signaling pathways.
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OBJECTIVE@#To analyze the characteristics of gene mutation and overexpression in newly diagnosed multiple myeloma (NDMM) patients.@*METHODS@#Bone marrow cells from 208 NDMM patients were collected and analyzed. The gene mutation of 28 genes and overexpression of 6 genes was detected by DNA sequencing. Chromosome structure abnormalities were detected by fluorescence in situ hybridization (FISH).@*RESULTS@#Gene mutations were detected in 61 (29.33%) NDMM patients. Some mutations occurred in 5 or more cases, such as NRAS, PRDM1, FAM46C, MYC, CCND1, LTB, DIS3, KRAS, and CRBN. Overexpression of six genes (CCND1, CCND3, BCL-2, CCND2, FGFR3, and MYC) were detected in 83 (39.9%) patients, and cell cycle regulation gene was the most common. Single nucleotide polymorphisms (SNP) changes were detected in 169 (81.25%) patients, the TP53 P72R gene SNP (70.17%) was the most common. Abnormality in chromosome structure was correlated to gene overexpression. Compared to the patients with normal chromosome structure, patients with 14q32 deletion showed higher proportion of CCND1 overexpression. Similarly, patients with 13q14 deletion showed higher proportion of FGFR3 overexpression, whereas patients with 1q21 amplification showed higher proportion of CCND2, BCL-2 and FGFR3 overexpression.@*CONCLUSION@#There are multiple gene mutations and overexpression in NDMM. However, there is no dominated single mutation or overexpression of genes. The most common gene mutations are those in the RAS/MAPK pathway and the genes of cyclin family CCND are overexpression.
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Humanos , Aberraciones Cromosómicas , Hibridación Fluorescente in Situ , Mieloma Múltiple/genética , MutaciónRESUMEN
Objective:To explore the basic biological characteristics of lncRNA B230352I09 and its role in the process of myocardial injury.Methods:We analyzed the biological characteristics of lncRNA B230352I09 on the UCSC website and predicted the possible binding protein of lncRNA B230352I09 by the catRAPID. Real-time fluorescence quantitative (RT) PCR method was applied to detect the expression of lncRNA B230352I09 in heart tissues at different time points (0, 1, 3, 7d) within 7 days after birth, the organs distribution and expression of lncRNA B230352I09 in neonatal mouse and the expression pattern of lncRNA B230352I09 in the heart of mice with myocardial injury. In addition, we constructed hypoxia model by culturing primary cardiomyocytes to detect the effect of lncRNA 230352I09 overexpression on hypoxic cardiomyocyte apoptosis by Hoechst staining kit, the effect of lncRNA B230352I09 overexpression on ROS content of hypoxic cardiomyocyte by DCFDA probe and changes in mitochondrial membrane potential of hypoxic cardiomyocytes by JC-1 Fluorescent probes.Results:Full-length of mouse B230352I09 was 663bp, located in the chr7:123031415-123066439 forward strand. RBBP6 gene was adjacent to B230352I09, which may be the target of lncRNA B230352I09 by catrapid prediction analysis. With the development of the heart, the expression level of lncRNA B230352I09 showed a gradual downward trend. The main expression organs of lncRNA B230352I09 in 1-day-old mice were heart, brain, kidney and liver. In heart tissue, lncRNA B230352I09 expression in non-cardiomyocytes was significantly less than in cardiomyocytes [ (1.0± 0.03) vs. (9.2± 3.29), P=0.013]. After myocardial injury, the expression level of lncRNA B230352I09 showed an increasing trend compared with the normal developing mice, but there was no statistical significance. Hoechst staining showed that lncRNA B230352I09 could inhibit the apoptosis of hypoxic cardiomyocytes. Detecting the content of ROS in cardiomyocytes showed that compared with the hypoxia group, the generation of ROS was significantly reduced in the lncRNA B230352I09 overexpression group ([(3.8±0.71) vs. (1.65±0.56), P=0.015]). JC-1 fluorescent probe was used to detect the mitochondrial membrane potential, and the results showed that the mitochondrial membrane potential of cardiomyocytes in the lncRNA B230352I09 overexpression group was significantly higher than that in the hypoxia group. Conclusions:In heart tissue, lncRNA B230352I09 was mainly expressed in cardiomyocytes. LncRNA B230352I09 has a protective effect in the process of myocardial injury in mice, mainly by inhibiting apoptosis of cardiomyocytes, reducing ROS production, and protecting mitochondrial membrane potential of cardiomyocytes.
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Abstract Preterm birth is the leading cause of infant mortality. The mechanisms that instigate preterm birth remain elusive and this makes it difficult to predict or prevent preterm birth. In this study, the authors found that SP-A induced pathological damage to the placenta and promoted preterm birth. Through mechanism, SP-A promoted the expression of STOX1 which further promoted the oxidative stress in the placenta by inhibiting the activities of a series of antioxidant enzymes including SOD, CAT and GSH-Px. SP-A also induced dysregulation of arginine metabolism by inhibiting NOS2 and ARG2. Overexpression of STOX1 aggravated SP-A induced oxidative stress, pathological damage, and preterm birth, whereas knockdown of STOX1 alleviated SP-A induced oxidative stress, pathological damage and preterm birth. The present study uncovers that SP-A induces preterm birth by promoting oxidative stress via upregulating STOX1, which provides new targets for the prediction and prevention of preterm birth.
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Chalcone isomerase (CHI) is the second rate-limiting enzyme involved in the biosynthetic pathway of flavonoids in Glycyrrhiza uralensis. Based on our previous studies, we selected the specific CHI haplotype (GenBank Accession No. KY115232) to maximize flavonoid accumulation. We constructed a plant binary expression vector for overexpression of this CHI gene by the gene fusion method and transfected the plasmid into Agrobacterium tumefaciens ACCC10060 by electroporation. The recombinant A. tumefaciens ACCC10060 subsequently was used to infect cotyledons and hypocotyls of G. uralensis to obtain transgenic hairy roots. A qRT-PCR method was used to determine the copy number of CHI and a UPLC method was used to assay the content of four flavonoids in different hairy root lines. The qRT-PCR results showed that the copy number of CHI in hairy roots was 1 or 5. UPLC results showed that the content of total flavonoids, liquiritin, liquiritigenin, and isoliquiritigenin in transgenic hairy root samples was significantly higher than that in wild-type samples. This study demonstrates that overexpression of CHI significantly increases the content of flavonoids in hairy roots of G. uralensis. This work provides a theoretical basis for clarifying the function of CHI. Three transgenic hairy root lines of G. uralensis were isolated which can be used to increase the accumulation of licorice flavonoids in vitro.
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Ferulate 5-hydroxylase (F5H) is a key enzyme involved in the phenylpropane metabolism pathway. Based on our previous transcriptome sequencing study, F5H played a negative regulatory role in glycyrrhizic acid (GA) biosynthesis. Therefore, in this study we cloned the F5H gene and investigated its regulatory effect on GA accumulation through gene overexpression and knockout. F5H was cloned from Glycyrrhiza glabra L. (GenBank Accession No. MK882511). A plant binary expression vector pCA-F5H was constructed by inserting F5H into pCAMBIA1305.1 at Spe I and Bgl II sites. The sgRNA sequences were designed based on the first exon of F5H. The CRISPR/Cas9 gene editing vector pHSE-F5H was constructed by inserting F5H sgRNA into pHSE401 at two Bsa Ⅰ sites. PCA-F5H and pHSE-F5H were transfected into Agrobacterium tumefaciens ATCC15834, which was used to induce hairy root overexpressing or knocking out F5H with licorice hypocotyl as explants. At the same time, wild type and negative control hairy roots were also generated. UPLC was used to assay the GA content in different hairy root lines, and results showed that the GA content in hairy root lines knocking out F5H was significantly higher, whereas in hairy root lines overexpressing F5H GA content was lower than that in the wild-type and negative control. In this work, through a reverse genetics strategy, the negative regulatory effect of F5H on GA biosynthesis was confirmed through gene overexpression and knockout. This work will lay a foundation for further elucidation of the molecular regulatory network of GA biosynthesis.
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1-Deoxy-D-xylulose-5-phosphate synthase (DXS) is a rate-limiting enzyme involved in the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway for terpenoid precursor biosynthesis. DXS plays an essential role in glycyrrhizic acid (GA) biosynthesis. Based on our previous transcriptome study, there was a negative correlation between DXS expression and GA content. Therefore, we explored the regulatory role of DXS in GA biosynthesis using both gene overexpression and gene knockout in a hairy root culture system. DXS was cloned from Glycyrrhiza glabra L. (GenBank Accession No. MN158121). A plant binary expression vector pCA-DXS was constructed by a gene fusion method. The sgRNA sequence was designed based on the first exon of DXS to construct the gene editing vector pHSE-DXS. Hairy roots overexpressing or knocking out DXS were generated through an Agrobacterium-mediated method with licorice hypocotyls as explants. Wild-type hairy roots and negative control hairy roots containing empty plasmids were also evaluated. UPLC was used to determine the GA content in each licorice hairy root line. Results showed that the content of GA in the hairy root group knocking out DXS was significantly higher than that in the wild-type and negative control groups, while in the hairy root group overexpressing DXS was significantly lower, suggesting that DXS plays a negative role in GA biosynthesis. This study provides a foundation for determining the function of DXS in terpenoid metabolism and for further establishment of a molecular regulatory network of GA biosynthesis.
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Objective To investigate whether the overexpression of neurogenin 3 ( Ngn3 ) can promote the induced differentiation of human umbilical cord mesenchymal stem cells ( HUCMSCs) into insulin-producing cells (IPGs). Methods HUCMSCs were isolated and cultured, identified by flow cytometry, and the differentiation potential was identified by adipogenesis and osteogenesis induction. HUCMSCs were induced into IPCs in different stages, including a low glucose induction stage and a high glucose induction stage. The experiment was divided into two groups, the control group was induced by the above scheme, while the experimental group was additionally infected the lentivirus overexpression vector carrying the target gene Ngn3 on the 6th day of the same induction process. After induction, the changes of cell structure were observed by electron microscope ; mRNA and protein was collected and Real-time PCR and Western blotting were used to compare the expressions of insulin and musculoaponeurotic fibrosarcoma oncogene homolog A Mafa in the two groups ; medium supernatant was collected and C-peptide content was determined by ELISA. Results HUCMSCs were successfully isolated with positive expression of CD 105 and CD90 and negative expression of CD34 and CD45, which had adipogenic and osteogenic differentiation ability. Then, HUCMSCs were induced into IPCs by stage induction, and the cells expressed Mafa and insulin positively. Ngn3 was overexpressed in the experimental group during the induction. After induction, electron microscopy showed that the cell structure was more mature in the experimental group. The expression levels of insulin and Mafa in the experimental group were significantly higher than those in the control group. During the induction process, the amount of C-peptide secreted by the experimental group was higher than that of the control group. Conclusion Lentivirus-mediated Ngn3 overexpression improves the differentiation efficiency of HUCMSCs into IPCs.
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Objective To investigate the protective effect of nuclear factor E2-related factor 2(Nrf2)on hydrogen peroxide (H