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.

Subclinical signs of podocyte injury associated with Circulating Anodic Antigen (CAA) in Schistosoma mansoni-infected patients in Brazil

ABSTRACT Background: The long-term effects of schistosomiasis on the glomerulus may contribute to the development of chronic kidney disease. This study aimed to investigate baseline Schistosoma mansoni-Circulating Anodic Antigen (CAA) levels and their association with kidney biomarkers related to podocyte injury and inflammation in long-term follow-up after praziquantel (PZQ) treatment. Methods: Schistosoma infection was diagnosed by detecting CAA in urine using a quantitative assay based on lateral flow using luminescent up-converting phosphor reporter particles. A cutoff threshold of 0.1 pg/mL CAA was used to diagnose Schistosoma infection (baseline) in a low-prevalence area in Ceará, Northeast, Brazil. Two groups were included: CAA-positive and CAA-negative individuals, both of which received a single dose of PZQ at baseline. Urinary samples from 55 individuals were evaluated before (baseline) and at 1, 2, and 3 years after PZQ treatment. At all time points, kidney biomarkers were quantified in urine and adjusted for urinary creatinine levels. Results: CAA-positive patients had increased baseline albuminuria and proteinuria and showed greater associations between kidney biomarkers. CAA levels correlated only with Vascular Endothelial Growth Factor (VEGF) (podocyte injury) levels. Increasing trends were observed for malondialdehyde (oxidative stress), monocyte chemoattractant protein-1 (inflammation marker), and VEGF. In the follow-up analysis, no relevant differences were observed in kidney biomarkers between the groups and different periods. Conclusions: S. mansoni-infected individuals presented subclinical signs of glomerular damage that may reflect podocyte injury. However, no causal effect on long-term renal function was observed after PZQ treatment.

Establishment of a reporter system for estimating activation of human hepatic stellate cells based on COL1A1 promoter and enhanced green fluorescent protein / 北京大学学报(医学版)

OBJECTIVE@#To establish a visual reporting system for evaluating the activity of collagen Ⅰ α 1 chain (COL1A1) gene promoter in immortalized human hepatic stellate cells, so as to estimate the activation status of the cells and provide a new cell model for the screening and study of anti-hepatic fibrosis drugs.@*METHODS@#The promoter sequence of human COL1A1 was amplified from the genomic DNA of human hepatocarcinoma cell line HepG2. Based on the pLVX-AcGFP1-N1 plasmid, the recombinant plasmid pLVX-COL1A1-enhanced green fluorescent protein (EGFP) was constructed, in which the enhanced green fluorescent protein gene expression was regulated by the COL1A1 promoter. The monoclonal cell line was acquired by stably transfecting pLVX-COL1A1-EGFP into the immortalized human hepatic stellate cell line LX-2 by the lentivirus packaging system and screening. The cell line was treated with transforming growth factor-β1 (TGF-β1) or co-treated with TGF-β1 and drugs with potential anti-hepatic fibrosis effects. The EGFP fluorescence intensity in cells was analyzed by the fluorescence microscope and ImageJ 1.49 software using a semi-quantitative method. The COL1A1 and EGFP mRNA were detected by reverse transcription real-time quantitative PCR (RT-qPCR), and corresponding proteins were detected by Western blot.@*RESULTS@#The recombinant plasmid pLVX-COL1A1-EGFP with the expression of EGFP regulated by COL1A1 promoter was successfully constructed. Kozak sequence was added to enhance the expression of EGFP, which was identified by double digestion and sequencing. The LX-2 monoclonal cell line LX-2-CE stably transfected with pLVX-COL1A1-EGFP was obtained. After co-treatment with TGF-β1 and 5 μmol/L dihydrotanshinone Ⅰ with potential anti-hepatic fibrosis effect for 24 h, the total fluorescence intensity and the average fluorescence intensity of LX-2-CE were lower than those in TGF-β1 single treatment group (P < 0.05), the intracellular mRNA and protein levels of COL1A1 and EGFP were also lower than those in the TGF-β1 single treatment group (P < 0.05).@*CONCLUSION@#A reporter system for estimating activation of hepatic stellate cells based on COL1A1 promoter regulated EGFP expression is successfully constructed, which could visually report the changes in COL1A1 expression, one of the activation-related markers of hepatic stellate cells, in vitro. It provides a new cell model for the screening and study of anti-hepatic fibrosis drugs.

miR-23b-3p regulates the differentiation of goat intramuscular preadipocytes by targeting the PDE4B gene / 生物工程学报

This study aimed to explore the effect of miR-23b-3p on the differentiation of goat intramuscular preadipocytes, and to confirm whether miR-23b-3p plays its roles via targeting the PDE4B gene. Based on the pre-transcriptome sequencing data obtained previously, the miR-23b-3p, which was differentially expressed in goat intramuscular adipocytes before and after differentiation, was used as an entry point. real-time quantitative-polymerase chain reaction (qPCR) was used to detect the expression pattern of miR-23b-3p during the differentiation of goat intramuscular preadipocytes. The effects of miR-23b-3p on adipose differentiation and adipose differentiation marker genes were determined at the morphological and molecular levels. The downstream target genes of miR-23b-3p were determined using bioinformatics prediction as well as dual luciferase reporter assay to clarify the targeting relationship between miR-23b-3p and the predicted target genes. The results indicated that overexpression of miR-23b-3p reduced lipid droplet accumulation in goat intramuscular adipocytes, significantly down-regulated the expression levels of adipogenic marker genes AP2, C/EBPα, FASN, and LPL (P < 0.01). In addition, the expressions of C/EBPβ, DGAT2, GLUT4 and PPARγ were significantly downregulated (P < 0.05). After interfering with the expression of miR-23b-3p, lipid droplet accumulation was increased in goat intramuscular adipocytes. The expression levels of ACC, ATGL, AP2, DGAT2, GLUT4, FASN and SREBP1 were extremely significantly up-regulated (P < 0.01), and the expression levels of C/EBPβ, LPL and PPARγ were significantly up-regulated (P < 0.05). It was predicted that PDE4B might be a target gene of miR-23b-3p. The mRNA expression level of PDE4B was significantly decreased after overexpression of miR-23b-3p (P < 0.01), and the interference with miR-23b-3p significantly increased the mRNA level of PDE4B (P < 0.05). The dual luciferase reporter assay indicated that miR-23b-3p had a targeting relationship with PDE4B gene. MiR-23b-3p regulates the differentiation of goat intramuscular preadipocytes by targeting the PDE4B gene.

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.

Development of porcine induced pluripotent stem cells with a CD163 reporter system / 生物工程学报

As main recipient cells for porcine reproductive and respiratory syndrome virus (PRRSV), porcine alveolar macrophage (PAM) are involved in the progress of several highly pathogenic virus infections. However, due to the fact that the PAM cells can only be obtained from primary tissues, research on PAM-based virus-host interactions remains challenging. The improvement of induced pluripotent stem cells (iPSCs) technology provides a new strategy to develop IPSCs-derived PAM cells. Since the CD163 is a macrophage-specific marker and a validated receptor essential for PRRSV infection, generation of stable porcine induced pluripotent stem cells lines containing CD163 reporter system play important roles in the investigation of IPSCs-PAM transition and PAM-based virus-host interaction. Based on the CRISPR/Cas9- mediated gene editing system, we designed a sgRNA targeting CD163 locus and constructed the corresponding donor vectors. To test whether this reporter system has the expected function, the reporter system was introduced into primary PAM cells to detect the expression of RFP. To validate the low effect on stem cell pluripotency, we generated porcine iPSC lines containing CD163 reporter and assessed the pluripotency through multiple assays such as alkaline phosphatase staining, immunofluorescent staining, and EdU staining. The red-fluorescent protein (RFP) expression was detected in CD163-edited PAM cells, suggesting that our reporter system indeed has the ability to reflect the expression of gene CD163. Compared with wild-type (WT) iPSCs, the CD163 reporter-iPSCs display similar pluripotency-associated transcription factors expression. Besides, cells with the reporter system showed consistent cell morphology and proliferation ability as compared to WT iPSCs, indicating that the edited-cells have no effect on stem cell pluripotency. In conclusion, we generated porcine iPSCs that contain a CD163 reporter system. Our results demonstrated that this reporter system was functional and safe. This study provides a platform to investigate the iPS-PAM development and virus-host interaction in PAM cells.

Evaluation of stability of Luc2P reporter cell lines by duplex digital PCR / 中国生物制品学杂志

@#Objective To develop a duplex digital PCR(dPCR) for evaluation of the stability of luciferase(Luc) gene in Luc2P reporter cell lines(CHO-K1,Hacat,HEK293 and UT7).Methods Genomic DNAs of Luc2P reporter cell lines were extracted,a duplex dPCR was developed to determine the copies of reference gene RPP30 and the target gene Luc,and the relative copy number of Luc(copies Luc/copy RPP30) was employed as the indicator for the stability evaluation of Luc gene;The developed method was verified for the specificity,precision,linearity,accuracy and durability,and analyzed for the applicability,according to the related requirements in Chinese Pharmacopoeia(Volume Ⅲ,2020 edition).Results All the original cells without reporter gene transfection were negative,while all the four reporter cell lines were positive,and the negative and positive regions in dPCR results were clearly distinguished;The relative standard deviation(RSD) of the eight repeated detections of the same genomic DNA sample and the six independent extractions of genomic DNA sample of the same cell were all less than 10%,and the linear fitting R~2 values were more than 0.99 for both Luc and RPP30.The spike recoveries of five groups of samples detected by the developed method were between 50% and 100%,and the results of chip-type dPCR and droplet-type dPCR were consistent.This method distinguished the relative copy number of Luc in different cell clones,and the results of detecting the relative copy number of Luc in three passages(P8,P12 and P31) were highly consistent.Conclusion The developed duplex dPCR method has good specificity,precision,linearity,accuracy,durability and applicability,and might be used to evaluate the stability of Luc gene in Luc2P reporter cell lines.

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.

Relationship between miR-26a and metadherin and the verification of tumor-bearing experiment in nude mice / 解剖学报

Objective To explore the relationship between miR-26a and metadherin (MTDH), and to verify the relationship between miR-26a and MTDH in vivo in nude mice. Methods Immunohistochemical SP staining method was used to detect the expression of MTDH and in situ hybridization was used to detect the expression of miR-26a in 86 cases of esophageal cancer, and the correlation between the expressions was analyzed. The bioinformatics prediction Targetscan Human 7. 2 software could predicte the binding fragment of MTDH on the miR-26a sequence, and the luciferase report experiment was used to verify the targeted regulatory relationship between MTDH and miR-26a. Nude mice were injected esophageal cancer cell lines subcutaneously which were lentiviral interferenced and overexpressed miR-26a to observe the fonnation of tumors. The tumors from nude mice were made into paraffin, and each was detected. The expression of MTDH in miR-26a in the tumor groups was detected by immunohistochemical staining and in situ hybridization and the relationship was analyzed. Results The expression of miR-26a in esophageal cancer tissues was significantly lower than that in paired nonnal esophageal tissues, and the expression of MTDH in esophageal cancer tissues was significantly higher than that in paired normal esophageal tissues. The expression of miR-26a was related to the patient' s pathological grade (P<0. 05), N stage(P<0. 05), and tumor volume (P<0. 01). The expression of MTDH in esophageal cancer was related to the N stage (P<0. 05) and the degree of differentiation (P<0. 01). Targetscan Human7. 2 bioinformatics software predicted that the MTDH gene contained a target sequence of hsa-miR-26a.The luciferase reporter gene experiment also verified the targeted regulation relationship between miR-26a and MTDH. The expression of miR-26a was the highest in KYSE-450 cells and the lowest in Ecal09 cells. The mRNA expression of MTDH in the lv-miR-26a group was significantly lower than that in the lv-NC group, and the mRNA expression in the lv-miR-26a-inhibitor group was significantly higher than that in the lv-NC group. Alter tumor formation, miR-26a expression increased and MTDH expression decreased in miR-26a group. Alter tumor formation, the expression oi miR-26a decreased and the expression oi MTDH increased in miR-26a inhibitor group. Conclusion MiR-26a can inhibit the expression oi MTDH in esophageal cancer cells. Both in vitro and in vivo experiments can verily the targeted regulatory relationship between miR-26a and MTDH. MiR-26a ma)' play a role in the occurrence and development oi esophageal cancer through the MTDH.

Activating Effect of Effective Components in Medicinal and Edible Substances on Human Pregnane X Receptor and Cytotoxicity Screening / 中国实验方剂学杂志

ObjectiveTo explore the activating effects of ten important effective components in seven medicinal and edible substances on human pregnane X receptor （PXR）， including Glycyrrhizae Radix et Rhizoma （liquiritin and glycyrrhizic acid）， Houttuyniae Herba （quercetin and houttuyfonate）， Prunellae Spica （rosmarinic acid）， Cassiae Semen （aurantio-obtusin）， Poria （pachymic acid）， Lilii Bulbus （Lilium brownii saponin and colchicine）， and Lycii Fructus （Lycium barbarum polysaccharide） and screen potentially toxic components. MethodCell counting kit-8 （CCK-8） assay was used to investigate the cytotoxic effect of liquiritin， glycyrrhizic acid， quercetin， houttuyfonate， rosmarinic acid， pachymic acid， aurantio-obtusin， and colchicine （10， 20， and 50 μmol·L-1）， and L. brownii saponin and L. barbarum polysaccharide （10， 20， and 50 mg·L-1） on normal human hepatocyte cell line （L02）. The release of lactate dehydrogenase （LDH） in L02 cells after drug treatments was detected by the biochemical analyzer. The apoptosis induced by ten effective components was explored by Hoechst 33342 staining. The secreted luciferase reporter system was used to co-transfect the PXR expression vector and reporter gene vector containing cytochrome P450 3A4 （CYP3A4） transcriptional regulatory region into L02 cells， with 10 μmol·L-1 rifampicin （RIF） as a positive control. After treated with liquiritin， glycyrrhizic acid， quercetin， houttuyfonate， rosmarinic acid， aurantio-obtusin， pachymic acid， and colchicine （5， 10， and 20 μmol·L-1） and L. brownii saponin and L. barbarum polysaccharide （5， 10， and 20 mg·L-1） for 24 h， the cells were tested for secreted luciferase activity. ResultCompared with the control group， colchicine， L. brownii saponin， and quercetin decreased the cell viability （P<0.05， P<0.01）. Compared with the control group， quercetin， rosmarinic acid， glycyrrhizic acid， colchicine， aurantio-obtusin， and pachymic acid increased the release rate of LDH in L02 cells （P<0.05， P<0.01）. The proportion of hyperchromatic nuclei increased gradually after rosmarinic acid， liquiritin， and L. barbarum polysaccharide treatments as compared with the control group （P<0.05， P<0.01）. In terms of co-transfection of pcDNA3.1-PXR and pGLuc-CYP3A4 into L02 cells， compared with the control group， aurantio-obtusin and pachymic acid showed activating effects on PXR （P<0.05）， whereas liquiritin and glycyrrhizic acid showed inhibitory effects （P<0.05）. ConclusionThe findings suggest that when medicinal and edible substances are taken for a long time， attention should be paid to their influence on drug-metabolizing enzymes and possible interactions， so as to improve their safety.

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.

A living cell-based fluorescent reporter for high-throughput screening of anti-tumor drugs / 药物分析学报

Suppression of cellular O-linked β-N-acetylglucosaminylation (O-GlcNAcylation) can repress prolifera-tion and migration of various cancer cells,which opens a new avenue for cancer therapy.Based on the regulation of insulin gene transcription,we designed a cell-based fluorescent reporter capable of sensing cellular O-GlcNAcylation in HEK293T cells.The fluorescent reporter mainly consists of a reporter (green fluorescent protein (GFP)),an internal reference (red fluorescent protein),and an operator (neuronal differentiation 1),which serves as a "sweet switch" to control GFP expression in response to cellular O-GlcNAcylation changes.The fluorescent reporter can efficiently sense reduced levels of cellular O-GlcNAcylation in several cell lines.Using the fluorescent reporter,we screened 120 natural products and obtained one compound,sesamin,which could markedly inhibit protein O-GlcNAcylation in HeLa and human colorectal carcinoma-116 cells and repress their migration in vitro.Altogether,the present study demonstrated the development of a novel strategy for anti-tumor drug screening,as well as for con-ducting gene transcription studies.

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.

MicroRNA-141-3p expression in serum of patients with cerebral hemorrhage and its mechanism / 解剖学报

Objective To analyze the expression level of microRNA-141-3p (miR-141-3) in patients with intracerebral hemorrhage (ICH), and explore the effect and mechanism of miR-141-3p on cerebral hemorrhage injury in rats. Methods Forty patients with ICH and 40 healthy controls in total were enrolled in this study. The expression of miR- 141-3p in peripheral blood serum was determined by the Real-time PCR method. The target relationship between miR-141- 3p and NOD-like receptor 3 (NLRP3) 3′ UTR was confirmed by dual luciferase reporter assay. miR-141-3p agonist and agonist NC were injected into rats via the lateral ventricle, respectively. On day 7 after treatment, the neurological function score was evaluated, and then all rats were killed to obtain brain tissue. Brain water content was examined by the dried and wet mass. HE staining was conducted to observe the pathological changes of cerebral tissue. The mRNA expressions of NLRP3 and miR-141-3p were detected by Real-time PCR. The protein expression of interleukin (IL)-lβ, IL-6 and IL-18 were detected by Western blotting analysis. Results The expression of miR-141-3p in serum of ICH patients was significantly down-regulated compared to healthy controls and negatively correlated with the severity of edema around the hematoma [(0.068±0.038) vs (0.520±0.028), t = 15.93, P<0.001; r =-0.8948, -0.9434 to-0.8087, P<0.001 ]. The result of luciferase reporter assay showed that miR-141-3p was related to the regulation of NLRP3 gene expression. The relative expression levels of miR-141-3p in agonist group were significantly higher than those in the agonist NC group (P< 0.001), while the expression levels of NLRP3, IL-lβ, IL-6 and IL-18 were significantly lower than those in the agonist NC group (P< 0.001). Compared with the agonist NC group, the cerebral water content reduced significantly (P< 0.001), and the neurological function score was significantly improved on the day 7 after treatment in agonist group (P< 0.001). The result of HE staining showed that injection of miR-141-3p in ICH rats could reduced the severity of edema around the hematoma. Conclusion MiR-141-3p alleviates ICH-induced inflammatory injury in rat possibly by modulating miR-141-3p.

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.

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.

LncRNA-599554 sponges miR-15a-5p to contribute inductive ability of dermal papilla cells through positive regulation of the expression of Wnt3a in cashmere goat

BACKGROUND: Long non-coding RNAs (lncRNAs), as post-transcriptional regulators, were thought to function in the inductive property of dermal papilla cells (DPCs) in cashmere goat. Previously, lncRNA-599554 was identified in secondary hair follicle (SHF) of cashmere goat, but its functional significance is unknown. RESULTS: In the present investigation, we verified that lncRNA-599554 had significantly higher expression at the anagen dermal papilla of cashmere goat SHF than that at telogen. Based on overexpression and knockdown techniques, we found that lncRNA-599554 contributes the inductive property of DPCs of cashmere goat, which was assessed by detecting the changes in the expression of several typical indictor genes in DPCs including ET-1, SCF, Versican, ALP, Lef1 and Ptc-1. Based on RNA pull-down assay, we verified that lncRNA-599554 directly interacted with chi-miR-15a-5p. Also, we showed that lncRNA-599554 positively regulated the Wnt3a expression in DPCs but which did not appear to involve its modulating of promoter methylation. Based on the use of Dual-luciferase reporter assays, our data indicated that lncRNA-599554 regulated the Wnt3a expression through chi-miR-15a-5p-mediated post-transcriptional level. CONCLUSIONS: We showed that lncRNA-599554 contributes the inductive property of DPCs in cashmere goat which might be achieved through sponging chi-miR-15b-5p to promote the Wnt3a expression. The results from the present investigation provided a novel insight into the functional mechanism of lncRNA-599554 in the SHF regeneration of cashmere goat along with the formation and growth of cashmere fiber.