A reporter gene assays for bioactivity determination of human chorinonic gonadotropin / 药学学报

This study constructed a LHCGR-CRE-luc-HEK293 transgenic cell line according to the activation of the cAMP signaling pathway after recombinant human chorionic gonadotropin binding to the receptor. The biological activity of recombinant human chorionic gonadotropin was assayed using a luciferase assay system. The relative potency of the samples was calculated using four-parameter model. And the method conditions were optimized to validate the specificity, relative accuracy, precision and linearity of the method. The results showed that there was a quantitative potency relationship of human chorinonic gonadotropin (hCG) in the method and it was in accordance with the four-parameter curve. After optimization, the conditions were determined as hCG dilution concentration of 2.5 μg·mL-1, dilution ratio of 1∶4, cell number of 10 000-15 000 cells/well, and induction time of 6 h. The method had good specificity, relative accuracy with relative bias ranging from -8.9% to 3.4%, linear regression equation correlation coefficient of 0.996, intermediate precision geometric coefficient of variation ranging from 3.3% to 15.0%, and linearity range of 50% to 200%. This study successfully established and validated a reporter gene method to detect hCG biological activity, which can be used for hCG biological activity assay and quality control.

Prognostic significance of microRNA-20a-5p levels which promotes proliferation and invasion by targeting cyclin G2 in small cell lung cancer

MicroRNA-20a-5p (miR-20a-5p) has been shown to function as a tumor promoter factor in several cancers. However, its role in small cell lung cancer (SCLC) remains unclear. In this study, we have made an attempt to measure the tumor tissue levels of miR-20a-5p in patients with SCLC using quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). The biological function of miR-20a-5p in SCLC cells was investigated in vitro and in vivo studies, including cell proliferation, migration assays and tumorigenicity in nude mice. Meanwhile?we conducted the luciferase reporter assay to verify the biological relationship between miR-20a-5p and CCNG2. The expression of miR-20a-5p was significantly upregulated in human SCLC compared to that in normal tissues. Kaplan-Meier analysis indicated that patients with high expression of miR-20a-5p are closely related with the shorter survival of SCLC. Further, multivariate analysis showed that miR-20a-5p was an independent prognostic factor. Increasing miR-20a-5p expression promotes the proliferation, migration and invasion of the NCI-H446 cells in vitro and in vivo. Dual-luciferase reporter gene assay demonstrated that miR-20a-5p directly targets CCNG2. These findings suggest that miR-20a-5p levels might be a novel diagnostic and prognostic marker of SCLC. Inhibiting miR-20a-5p could be a promising therapeutic strategy for SCLC.

Reporter gene assay for detection of biological activity of human growth hormone / 中国生物制品学杂志

@#Objective To develop and verify a reporter gene assay(RGA) for the detection of biological activity of human growth hormone(hGH).Methods The biological activity of hGH was evaluated by the expression of luciferase(Luc)activated by hGH binding to hGH receptor(hGHR) on HEK293/GH-Luc cell membrane.The developed detection conditions were as follows:the initial concentration of sample was 1 μg/mL;the cell inoculation amount was(2.45～2.66) × 10~4 cells/well;the sample was of 3-fold serial dilution,with a total of 8 dilutions and the incubation time was 18～24 h.The relative biological activity of the sample was calculated by measuring Luc intensity and comparing it with the national standard by four-parameter fitting.The developed method was verified for specificity,repeatability,intermediate precision,relative accuracy,linear range and durability.Results The excipient components in product and the serum components in culture medium showed no effect on the activity detection results;The geometric coefficient of variation(GCV) of relative titer of one batch of samples in six repeated detections was 6.794%,much lower than 20%.The relative titer GCV detected by two experimenters in different batches of samples at different times were both lower than 20%;The relative deviations of the relative titer determination values of samples at different concentrations were within ±12%,the slope of linear regression equation was 0.982,the linear range was 0.6～1.6 μg/mL,and the coefficient of determination(R~2) was 0.997;The GCV of three batches of stock solutions and one batch of finished products were 4.758%,4.430%,7.294% and 2.771% respectively under the conditions of different cell generation,cell density and sampling location,all of which were less than 20%.Conclusion The developed RGA showed good specificity,repeatability,intermediate precision,relative accuracy,linear range and durability,which met the application requirements and was expected to replace the traditional in vivo biological activity detection methods for the activity evaluation and quality control of hGH.

A cell model for high-throughput screening GLP-1 receptor agonists / 中国药理学通报

Aim To establish a high-throughput screening cell model for GLP-1 receptor agonists. Methods A pEGFP-GLP-1R-3 C recombinant plasmid was constructed and transfected into HEK293T cells. The cells were screened with G418 and flow cytometry. The established stable cell line was named HEK293TGLP-lR-3C-eGFP cell line. The expression level of GLP-1 R-3C-eGFP protein was confirmed by Western blotting and laser confocal microscopy. Then cyclic adenosine monophosphate (cAMP) response element reporter gene was transfected into the HEK293T-GLP-lR-3C-eGFP cells. The luminescence values were detected by One-Step Luciferase Reporter Gene Assay Kit after stimulation with different concentrations of GLP-1 peptide. The luminescence values reflected the cellular cAMP level, which was verified using the cAMP kit (E L I S A). Results HEK293T-GLP-lR-3C-eGFP cell line was successfully constructed. The relative light unit change trend after stimulation with different concentrations of GLP-1 was similar to that of the cellular cAMP level change trend. The value of Z' in this experiment was 0.52. Conclusions A recombinant HEK293T cell line is established, which can be used for high-throughput screening of GLP-1 receptor agonists.

Collaborative study to evaluate a reporter gene assay for recombinant human follicle-stimulating hormone bioactivity / 药学学报

The goal of this work was to explore the prospect of standardized application of an in-vitro bioactivity assay for recombinant human follicle-stimulating hormone based on a reporter gene. The relative accuracy, intermediate precision, linearity and applicable range of the method were validated according to the General Rules of Chinese Pharmacopoeia 2020 edition Volume IV (9401). Three laboratories used this method to determine the in-vitro biological activities of six batches of drug product and three batches of drug substance manufactured by two different companies. The consistency of the potency determined by three laboratories, the intra-laboratory precision and inter-laboratory precision were analyzed. The method was optimized during the collaborative validation. The results of method validation meet the requirements of the General Rules of Chinese Pharmacopoeia 2020 edition Volume IV (9401). Aiming to resolve the problems found in the collaborative validation, the medium for cell seeding, the pre-diluted buffer solution of standard and sample, and the means of removing and discarding supernatant after stimulation were optimized. After optimization, there was no significant difference in the bioactivity among the different laboratories (P > 0.05), indicating statistical equivalency. Intra-laboratory and inter-laboratory precision were good and the geometric coefficient of variation (GCV%) were both less than 15%. In conclusion, the reporter gene assay has good intra-laboratory repeatability and inter-laboratory reproducibility and is suitable for analyzing recombinant human follicle-stimulating hormone drug product and drug substance by different manufacturers. It is expected to be used as a standardized method for the determination of the in-vitro bioactivity of such products.

Metformin and lipopolysaccharide regulate transcription of NFATc2 gene via the transcription factor RUNX2 / 南方医科大学学报

OBJECTIVE@#To construct a luciferase reporter gene vector carrying human nuclear factor of activated T cells 2 (NFATc2) gene promoter and examine the effects of metformin and lipopolysaccharide (LPS) on the transcriptional activity of NFATc2 gene.@*METHODS@#The promoter sequence of human NFATc2 gene was acquired from UCSC website for PCR amplification. NFATc2 promoter fragment was inserted into pGL3-basic plasmid double cleaved with Kpn Ⅰ and Hind Ⅲ. The resultant recombinant plasmid pGL3-NFATC2-promoter was co-transfected with the internal reference plasmid pRL-TK in 293F cells, and luciferase activity in the cells was detected. Reporter gene vectors of human NFATc2 gene promoter with different fragment lengths were also constructed and assayed for luciferase activity. The changes in transcription activity of NFATc2 gene were assessed after treatment with different concentrations of metformin and LPS for 24 h. We also examined the effect of mutation in RUNX2-binding site in NFATC2 gene promoter on the regulatory effects of metformin and LPS on NFATc2 transcription.@*RESULTS@#We successfully constructed pGL3-NFATc2-promoter plasmids carrying different lengths (2170 bp, 2077 bp, 1802 bp, 1651 bp, 1083 bp, 323 bp) of NFATc2 promoter sequences as verified by enzymatic digestion and sequencing. Transfection of 293F cells with the plasmid carrying a 1651 bp NFATc2 promoter (pGL3-1651 bp) resulted in the highest transcriptional activity of NFATc2 gene, and the luciferase activity was approximately 3.3 times that of pGL3-2170 bp (1.843 ± 0.146 vs 0.547 ± 0.085). Moderate (5 mmol/L) and high (10 mmol/L) concentrations of metformin significantly upregulated the transcriptional activity of pGL3-1651 bp by up to 2.5 and 3 folds, respectively. LPS at different doses also upregulated the transcriptional activity of pGL3-1651 bp by at least 1.6 folds. The mutation in the RUNX2 binding site on pGL3-1651 bp obviously reduced metformin- and LPS-induced enhancement of pGL3-1651bp transcription by 1.7 and 2 folds, respectively.@*CONCLUSION@#pGL3-NFATc2-promoter can be transcribed and activated in 293F cells, and LPS and metformin can activate the transcription of pGL3- NFATc2-promoter in a RUNX2-dependent manner.

Construction and efficacy evaluation of Rb luciferase reporter gene detection system / 西安交通大学学报(医学版)

【Objective】 To construct the Rb luciferase reporter gene assay system and detect the activation ability of Rb gene for screening the targeted drugs. 【Methods】 The synthetic Rb gene sequence was annealed to form a double-stranded DNA structure and then inserted into the polyclonal site of pGL6-TA. The junction product was transformed into E.coli DH5α competent cells for expanded culture, and the constructed pGL6-Rb-Luc plasmid and pGL6-TA plasmid were transfected into HEK293 cells. The monoclonal cell line HEK293-Rb-Luc with stable expression was screened by G418, and the activation and inhibition of Rb in HEK293-Rb-Luc were tested by serum and CDK4/6 inhibitor Palbociclib. 【Results】 The sequence of Rb reaction elements in pGL6-Rb-Luc was completely correct. The recovery of serum culture significantly increased the luciferase activity in HEK293-Rb-Luc (P<0.001). Compared with 0 nmol/L, 25, 50, 75 and 100 nmol/L, CDK4/6 inhibitor Palbociclib made the inhibition rate of Rb activity rise to 6.90%, 40.23%, 50.57% and 52.07%, respectively (P<0.05). 【Conclusion】 The Rb luciferase reporter gene detection system HEK293-Rb-Luc was successfully constructed, which can effectively detect the activation level of Rb.

The Biological Role of miR-340 in Colorectal Cancer Cells and the Regulatory Mechanism of Target Genes / 中国生物化学与分子生物学报

miR-340 can promote the proliferation and invasion of cancer cells, but how miR-340 regulates the occurrence and development of cancer in colon cancer is rarely reported. This study aims to explore the biological function and target gene regulation mechanism of miR-340 in colorectal cancer cells. Firstly, RT-qPCR was used to detect the expression level of miR-340 in different colorectal cancer cell lines, and then miR-340 was overexpressed or inhibited in COLO-205 cells. CCK-8, Transwell migration and invasion assay, and flow cytometry were performed to analyze the cell ability of proliferation, migration and invasion, as well as cell apoptosis and cell cycle. Finally, after bioinformatics prediction of miR-340 target genes, luciferase reporter gene and Western blot experiment were applied to verify those target genes. The results showed that miR-340 was downregulated in COLO-205 cells. Compared with the control group, cell proliferation, migration and invasion were significantly inhibited in the miR-340 overexpression group, but were promoted in the miR-340 suppression group (P<0. 01). The results of flow cytometry showed that the percentage of apoptosis in the miR-340 overexpression group was significantly increased, while the percentage of apoptosis in the miR-340 inhibition group was decreased (P<0. 01). The bioinformatics analysis of the overexpression miR-340 transfection group showed that the 3′UTR of glucose regulated protein 78 kD (GRP78) had a miR-340-5p binding site, and the luciferase activity was significantly reduced in the overexpression miR-340 group (P<0. 01); Western blot results also showed that overexpression of miR-340 can inhibit the expression of GRP78, while inhibiting miR-340 expression, the expression of GRP78 is relieved. In summary, miR-340 can directly target GRP78 to promote the apoptosis of COLO-205 cells and inhibit their proliferation, migration and invasion.

Construction and evaluation of a pUC-type prokaryotic promoter reporter system based on lacZ gene / 生物工程学报

To construct a prokaryotic promoter report system with wide applicability, a series of pFGH reporter vectors based on lacZ gene and pUC replicon were constructed from plasmid pFLX107 through the replacement of multiple cloning sites and sequence modifications. The plasmid with the lowest background activity was selected as the final report system with the lacZ gene deletion strain MC4100 as the host bacterium, following by testing with inducible promoter araBAD and the constitutive promoter rpsM. The background activity of pFGH06 was significantly lower than that of other plasmids of the same series, and even lower than that of reference plasmid pRCL at 28 °C (P<0.01). Further evaluation tests show that the plasmid pFGH06 could be used to clone and determine the activity of inducible promoter or constitutive promoter, and the complete recognition of the target promoter could be achieved through blue-white selection in the simulation test of promoter screening. Compared with the reported prokaryotic promoter report systems, pFGH06 has the advantages of smaller size, more multiple clone sites, adjustable background activity, high efficiency of promoter screening and recognition, thus with a wide application prospect.

A reporter gene assay for determining the biological activity of therapeutic antibodies targeting TIGIT

T cell immunoglobulin and ITIM domain (TIGIT) is a novel immune checkpoint that has been considered as a target in cancer immunotherapy. Current available bioassays for measuring the biological activity of therapeutic antibodies targeting TIGIT are restricted to mechanistic investigations because donor primary T cells are highly variable. Here, we designed a reporter gene assay comprising two cell lines, namely, CHO-CD112-CD3 scFv, which stably expresses CD112 (PVRL2, nectin-2) and a membrane-bound anti-CD3 single-chain fragment variable (scFv) as the target cell, and Jurkat-NFAT-TIGIT, which stably expresses TIGIT as well as the nuclear factor of activated T-cells (NFAT) response element-controlled luciferase gene, as the effector cell. The anti-CD3 scFv situated on the target cells activates Jurkat-NFAT-TIGIT cells through binding and crosslinking CD3 molecules of the effector cell, whereas interactions between CD112 and TIGIT prevent activation. The presence of anti-TIGIT mAbs disrupts their interaction, which in turn reverses the inactivation and luciferase expression. Optimization and validation studies have demonstrated that this assay is superior in terms of specificity, accuracy, linearity, and precision. In summary, this reliable and effective reporter gene assay may potentially be utilized in lot release control, stability assays, screening, and development of novel TIGIT-targeted therapeutic antibodies.

Collaborative study to evaluate a reporter gene assay for anti-PD-1 antibody bioactivity / 药学学报

A collaborative inter-laboratory validation was carried out using a reporter gene assay to measure the bioactivity of anti-PD-1 monoclonal antibody, in order to study the applicability and transferability of the method. In this study, two collaborative schemes were designed to measure the precision, linearity and accuracy of the method. The results showed that the 95% confidence interval (CI) of the intra-assay precision was (1.72-16.89) %, inter-assay precision was (2.63-17.67) %, inter-laboratory precision was (9.00-14.26) %, all linear correlation coefficients were greater than 0.99, and the 95% CI for the accuracy at different potency levels was (91.83-104.40) % at 50%, (90.40-101.40) % at 75%, (94.71-105.60) % at 100%, (94.00-102.00) % at 125%, and (96.73-104.30) % at 150%. The collaborative validation results proved that the reporter gene assay for the bioactivity determination of anti-PD-1 monoclonal antibody has good precision, linearity and accuracy, and could be applied to the release and stability analysis of anti-PD-1 monoclonal antibodies in different laboratories.

Nrf2-inducing and HMG-CoA reductase inhibitory activities of a polyphenol-rich fraction of Guazuma ulmifolia leaves

To fractionate and identify polyphenols from Guazuma ulmifolia Lam. leaves, and to explore their antioxidant, 5-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitory, and Nrf2 modulatory activities. Methods: The 1,1-diphenyl-2-picrylhydrazyl assay was used to evaluate the antioxidant activity of a polyphenolic fraction of the extract of Guazuma ulmifolia Lam. leaves. THP-1 gene reporter cell lines constructed with a transcriptional response element specific for Nrf2 and a minimal promoter for the firefly luciferase–green fluorescent protein transgene were used to determine the effect of the polyphenolic fraction on the Nrf2 signaling pathway. Furthermore, an assay of HMG-CoA reductase inhibitory activity was performed by using a commercial enzyme kit. Polyphenolic compounds were identified by liquid chromatography-tandem mass spectrometry. Results: The polyphenolic fraction showed fairly strong antioxidant activity [IC50 = (14.90 ± 4.70) μg/mL] and inhibited HMG-CoA reductase activity by 69.10％, which was slightly lower than that by pravastatin (84.37％) and quercetin (84.25％). Additionally, the polyphenolic fraction activated the Nrf2 antioxidant signaling pathway at 500 μg/mL. Eleven subfractions resulting from the column chromatography separation of the polyphenolic fraction also showed relatively strong antioxidant activities (IC50: 17.46–217.14 μg/mL). The subfraction (F6) stimulated the Nrf2 signaling pathway and had HMG-CoA reductase inhibitory activity (65.43％). Moreover, the subfraction contained two main flavonoids: quercetin and quercimeritrin. Conclusions: The polyphenolic fraction of Guazuma ulmifolia could induce antioxidant genes via the Nrf2/antioxidant regulatory elements pathway, and is a promising candidate for an inhibitor of HMG-CoA reductase.

The "target + activity" method for rapid discovery of active compounds targeting Hsp90 in pancreatic cancer cells from Physalis angulata L / 药学学报

The purpose of this study was to select the active compounds targeting Hsp90 protein in pancreatic cancer cells through a new dual "target + activity" rapid discovery technique. We combined an in vitro anti-cancer activity screening method with a dual-luciferase reporter gene and multi-chromatography separation technology, for rapid discovery of potential Hsp90 inhibitors from the Chinese herbal medicine Physalis angulata L. The anti-proliferation activity of those compounds was assessed in pancreatic cancer cell line BxPC-3 by MTT assays. The molecular mechanisms of Hsp90 inhibition were explored by Western blot and shRNA knockdown assays. As a result, two withanolides, withanolide E (WE) and 4β-hydroxywithanolide E (HWE), were identified from Physalis angulata L. The half maximal inhibitory concentration (IC50) of WE and HWE were 0.71±0.03 and 1.23±0.10 μmol·L-1 for the growth of BxPC-3 cells in 48 h. Luciferase reporter assay demonstrated that WE and HWE significantly induced heat shock element (HSE) activity in a dose- and time-dependent manner. The molecular mechanism study showed that after exposing to 5 μmol·L-1 WE or HWE for 48 h, the aggregation of Hsp90 dimer was upregulated to 6.5±1.3 and 11.8±2.0 fold, while the expression of Hsp90 client protein Akt was downregulated to 21.7%±2.8% and 9.8%±1.4% of the control group. Moreover, the Hsp90 inhibitory activity of WE or HWE was canceled by shRNA mediated Hsp90 knockdown. Overall, based on the dual "target + active" rapid discovery technique, two new Hsp90 inhibitors WE and HWE were found from Physalis angulata L. The Hsp90 inhibitory mechanism of WE and HWE may be mediated by induction of Hsp90 aggregate dimer and inhibition of Hsp90 client protein Akt expression.

Regulatory effect of grainyhead-like 2 gene on proliferation of epithelial ovarian cancer cells by nuclear factor erythroid-2-related factor 2 transcription / 解剖学报

Objective: To study the effect of nuclear factor erythroid-2-related factor 2(Nrf2) and the downstream gene grainyhead-like 2(GRHL2) on epithelial ovarian cancer cell lines and the interaction of Nrf2 and GRHL2. Methods: We conducted ChlP-PCR assay to test the binding of Nrf2 with six candidate genes including GRHL2. Furthermore, we proved whether Nrf2 could bind with the GRHL2 promoter and transcriptionally activate the GRHL2 gene or not. Moreover, if the overexpression and knockdown of Nrf2 could increase and decrease the GRHL2 protein respectively. Results: We discovered that fallopian tube epithelial cells taken from epithelial ovarian cancer patients and ovarian cancer cell lines highly expressed the Nrf2 and GRHL2 at mRNA level. The overexpression and knockdown of Nrf2 could increase and decrease the cells activity, respectively. However, the knockdown of GRHL2 could inhibit the influence of Nrf2 overexpression. Conclusion: Nrf2 promotes the activity of epithelial ovarian cancer cells via modulating the GRHL2 gene transcriptionally.

Molecular imaging for magnetotactic bacterial magnetosomes and related MRI reporter genes / 中国医学影像技术

Magnetotactic bacteria encode iron nanoparticles-magnetosomes, which are regulated by a group of genes, have organelle-like structures. Their unique structures have received much attention in recent years due to the distinctive properties, including applications of purified magnetosomes in magnetic particles imaging and of magnetosome-associated regulatory genes in molecular imaging as MRI reporter genes. Although the research on magnetosomes has been increasing in recent years, its application as MRI reporter gene is still in its infancy. Molecular imaging studies of magnetosomes and related genes as MRI reporter genes were reviewed in this article.

Development of a Novel Optimization and Validation Method Based on DOE for the ADCC Potency of Anti-PD-1/PD-L1 Monoclonal Antibodies Using Reporter Genes / 中国药学杂志

OBJECTIVE: To develop a novel optimization and validation method based on design of experiment(DOE) for the antibody-dependent cell-mediated cytotoxicity (ADCC) potency of anti-programmed cell death 1 and anti-programmed cell death-ligand 1 (PD-1/PD-L1) monoclonal antibodies using reporter genes. METHODS: Jurkat-hFcγRIIIa-NFAT transgenic cell line was used as effector cells, 293FT-PD-1 cell line and CHO-PD-L1 cell line were used as target cells, respectively. The ADCC potency for anti-PD-1/PD-L1 monoclonal antibodies was detected with Luciferase detection system (BrightGloTM Luciferase Assay system), then the method was optimized and validated based on DOE. RESULTS: The anti-PD-1/PD-L1 monoclonal antibodies showed a dose-response relationship and the determination result complied with the following four-parameter equation: y=(A-D)/+D. The method was optimized and the testing parameters were determined as follows: the working concentration of anti-PD-1 monoclonal antibody was 10 000 ng•mL-1 to 4.833 ng•mL-1 and that of anti-PD-L1 was 2 000 ng•mL-1 to 0.488 ng•mL-1, the ratio of effector cells and target cells for anti-PD-1/PD-L1 monoclonal antibodies were 6:1 and 3:1, and the induction time for both of these antibodies was 20 h. The method possessed good specificity. The recovery rate test samples in the four different dilution groups were determined for 3 times, and the results showed that the relative potencies of anti-PD-1 monoclonal antibody were (51.74±2.22)%, (77.12±3.14)%, (118.71±2.83)% and (156.20±12.99)%, and the recoveries of which were (103.49±4.44)%, (102.83±4.19)%, (94.96±2.26)% and (104.14±8.66)%, respectively. While as for anti-PD-L1 monoclonal antibody, the relative potencies were (54.32±4.75)%, (75.24±4.25)%, (127.40±2.43)%, (156.82±3.27)% and the recoveries were (108.64±9.51)%, (100.33±5.67)%, (101.92±1.94)% and (104.55±2.18)%, respectively. The RSDs of the above results were all less than 10%. CONCLUSION: A novel optimization and validation method based on DOE for detecting ADCC potency of anti-PD-1/PD-L1 mAb is successfully developed. This detecting method based on reporter gene shows high specificity, good reproducibility and high accuracy, and might be used in the evaluation of ADCC potency of anti-PD-1/PD-L1 mAb.

Construction of luciferase reporter gene cell model and its application in screening rhein derivatives targeting RAC1 / 中国药理学通报

Aim To establish luciferase reporter gene expression cell models of CNEi-RACI-Luc2 based on the target of RAC1 promoter, and explore the application of screening anti-tumor active of rhein derivatives targeted regulating RAC1 at transcriptional level. Methods The lentiviral carrying luciferase reporter vector was designed and synthesized using RAC1 promoter se-quence, and CNE1 cells were infected with recombinant plasmid lentiviral to obtain cell lines that stably expressed firefly luciferase. Luciferase reporter assay was used to detect the luciferase luminescence value after stimulating with RAC1 activator PMA and inhibitor NSC23766 that targeted regulating the RAC1 promoter activities in cells, and RAC 1 expression was verified by Western blot. The effect of series of rhein derivatives on the lu-cifcrase activity of RAC1 promoter was observed, and RAC1 expression was determined by Western blot. Results The identification result of double enzyme digestion showed that a lentiviral expression vector carrying luciferase reporter vector rc-combined with RAC1 promoter was successfully constructed. Lcntivirus-infcctcd CNE1 cells were screened by puromycin, the CNE1-RAC1-Luc2 cells stably expressing firefly luciferase were obtained, and the Iransfection efficiency was over 90%. The RAC1 luciferase reporter assay system was sensitive to FMA and NSC23766 and consistent with the result of RAC1 protein expression by Western blot. The regulation of series of rhein derivatives to RAC1 luciferase activity of CNE1-RAC1-Luc2 cells was consistent with the results of Western blot. Conclusions The cell model of luciferase reporting system containing RAC1 promoter can be successfully constructed, which provides a practical platform for high throughput screening of RAC1-targeted drugs.

MicroRNA-29a-3p regulates osteoblast differentiation and peri-implant osseointegration in a rat model of hyperlipidemia by modulating Frizzled 4 expression / 华西口腔医学杂志

OBJECTIVE@#This work aimed to study and identify the influence and target gene of microRNA-29a-3p (miR-29a-3p) in the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in a high-fat environment in vitro and in vivo.@*METHODS@#1) In vitro: BMSCs were randomly allocated into two groups and were then induced to undergo osteogenic differentiation in a normal or high-fat environment. Next, a miR-29a-3p mimic/inhibitor was transfected into the two groups of cells. The mRNA expression levels of alkaline phosphatase (ALP), Runt related gene 2 (Runx2), and miR-29a-3p and the protein expression levels of ALP and Runx2 were detected before and after transfection through reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) and Western blot analyses. Moreover, Frizzled (Fzd) 4 was predicted as the target gene of miR-29a-3p by using an online database (Target Scan, MiRNA.org). The interactive relationship between miR-29a-3p and Fzd4 was confirmed through dual-luciferase assays. 2) In vivo: Rats were randomly divided into two groups and fed with a standard or high-fat diet. Titanium implants were grown in rats. Then, the expression levels of miR-29a-3p, ALP, and Runx2 were detected in bone tissues surrounding implants. Moreover, hard tissue sections were subjected to methylene blue-acid magenta staining and observed under microscopy to study bone formation around implants. In addition, miR-29a-3p-overexpressing lentiviral vectors were transfected into rats, and the expression levels of ALP, Runx2, and miR-29a-3p in bone tissues surrounding implants were detected at 3 and 10 days after transfection.@*RESULTS@#The expression levels of ALP, Runx2, and miR-29a-3p and the osteogenic differentiation of BMSCs were suppressed in high-fat groups in vitro and in vivo.@*CONCLUSIONS@#MiR-29a-3p plays a positive role in the regulation of BMSCs in a high-fat environment. It can increase ALP and Runx2 expression levels in bone tissues surrounding implants in hyperlipidemia models. This result implies that miR-29a-3p can promote implant osseointergration in a rat model of hyperlipidemia.

Agrobacterium-Mediated Transient Assay of the Gus Gene Expression in Sugar Beet

Modification of transformation systems with a set of markers is almost used to confirm whether the transgene has been successfully transmitted to the host cells. Transient expression technique is a fast and simple way to analyze promoter expression. This method is not affected by the position of the transgene in the target genome. In the present study, the gus reporter gene directed by the CaMV 35S promoter and the nptII selectable gene were used for optimization of transformation event in sugar beet. The results demonstrated the activity of β-glucuronidase in the Agrobacterium cells showing suppressed expression of the prokaryotic reporter gene. The function of the pCAMBIA2301 vector was assessed through inoculation of shoot apex with Agrobacterium. The results demonstrated that cells adjacent to the main vein of leave reared from tissue cultured apical meristems were suitable for transformation and regeneration. The highest shoot regeneration was achieved for tissue-cultured leaf explants grown in the presence of BA, IBA and TDZ media. In this study, an improved protocol for regeneration and genetic engineering of a sugar beet genotype was described using the tested vector. Analysis of GUS Histochemical and polymerase chain reaction (PCR) of the T0 generation plants demonstrated that the tested vector enables the expression of the gus gene in the transgenic plants that was an evidence of transient expression.

Preliminary investigation on adenovirus-mediated transferrin receptor reporter gene in colorectal cancer cell MR imaging / 中国介入影像与治疗学

Objective To explore the best multiplicities of infection (MOI),the expression of the target gene and in vitro MR imaging of adenovirus vector-mediated transferrin receptor (TFRC) reporter gene transfection of human colorectal cancer Lovo cells.Methods Lovo cells were transfected with recombinant adenovirus (Ad-TFRC) at 5,10,50,100 MOI to determine the best MOI,and quantitative real-time PCR was performed to detect the eDNA of TFRC.The transfected cells were incubated in the culture medium including Tf-USPIO of various concentrations,and were observed by Prussian blue staining,then the cell viability was evaluated via Trypan blue staining.The labeled cells were scanned with 7.0T MR T2W,T2 map,T2* map sequences,and the signal intensities were analyzed.Results Ad-TFRC were successfully transfected into Lovo cells.The best MOI was 50,and the efficiency of infection was more than 90％.The relative expression amount of TFRC in transfected cells was higher than that in control Lovo cells by real-time quantitive PCR (P＜ 0.01).Prussian blue staining showed numerous blue iron particles in transfected cells when the best labeling concentration was 1.5 μg/ml.Trypan blue staining results of transfected Lovo cells and control Lovo cells was (93.80± 1.60)％ and (95.10±2.30) ％,respectively (P＞0.05).MR imaging in vitro showed that compared with control Lovo cells,the signal intensity decreased on T2WI,T2 map and T2* map sequences in transfected Lovo cells (P＜0.05).Conclusion TFRC reporter gene can be efficiently mediated by adenovirus for expression in Lovo cells.After magnetization labeling,7.0T MR imaging of Lovo cells can be successfully achieved in vitro.