Luciferase Assay

2001 ◽  
pp. 231-246
Keyword(s):  
1990 ◽  
Vol 63 (02) ◽  
pp. 286-290 ◽  
Author(s):  
Christina Beurling-Harbury ◽  
Pehr B Harbury

SummaryActin is the major ATP and ADP binding protein in platelets, 0.9–1.3 nmol/108 cells, 50–70% in the unpolymerized state. The goal of these experiments was to develop a method for extracting all protein-bound ATP and ADP from undisturbed platelets in plasma. Extraction of actin-bound ADP is routine while extraction of actin-bound ATP from platelets in buffer has been unsuccessful. Prior to extraction the platelets were exposed to 14-C adenine, to label the metabolic and actin pools of ATP and ADP. The specific activity was determined from the actin-bound ADP in the 43% ethanol precipitate. Sequential ethanol and perchlorate extractions of platelet rich plasma, and the derived supernatants and precipitates were performed. ATP concentrations were determined with the luciferase assay, and radioactive nucleotides separated by TLC. A total of 1.18 nmol/108 cells of protein-bound ATP and ADP was recovered, 52% ATP (0.61 nmol). The recovery of protein-bound ADP was increased from 0.3 to 0.57 nmol/108 cells. This approach for the first time successfully recovered protein bound ATP and ADP from platelets in a concentration expected for actin.


2019 ◽  
Vol 17 (4) ◽  
pp. 463-469
Author(s):  
Hou Deqiang ◽  
Gao Yufeng ◽  
Bai Ning ◽  
Dong Yu

Isoliquiritigenin is a flavonoid commonly found in liquorice and has been identified as a potent anti-tumor agent. The aim of this study was to investigate whether isoliquiritigenin regulates the proliferation and apoptosis of tongue squamous cell carcinoma cells by regulating forkhead box G1 expression via miR-21. MTT assay and flow cytometry were used to analyze cell proliferation and apoptosis, respectively. Quantitative real time polymerase chain reaction and western blotting were used to detect mRNA and protein expression levels, respectively. The relationship between miR-21 and forkhead box G1 was detected by dual luciferase assay. Isoliquiritigenin inhibited proliferation and induced apoptosis of tongue squamous cell carcinoma cells, and decreased miR-21 levels and promoted forkhead box G1 expression. Forkhead box G1 was then identified as a target of miR-21 and ISL could promote forkhead box G1 expression by inhibiting miR-21. Further analysis suggested that upregulation of miR-21 improved proliferation and suppressed apoptosis of tongue squamous cell carcinoma cells by inhibiting forkhead box G1 expression. Finally, our results revealed that isoliquiritigenin inhibited proliferation and induced apoptosis of tongue squamous cell carcinoma cells by regulating miR-21. Isoliquiritigenin might act as a novel therapeutic treatment for tongue squamous cell carcinoma cells through up-regulation of forkhead box G1 expression via inhibiting miR-21expression.


2019 ◽  
Vol 22 (5) ◽  
pp. 346-354
Author(s):  
Yan A. Ivanenkov ◽  
Renat S. Yamidanov ◽  
Ilya A. Osterman ◽  
Petr V. Sergiev ◽  
Vladimir A. Aladinskiy ◽  
...  

Aim and Objective: Antibiotic resistance is a serious constraint to the development of new effective antibacterials. Therefore, the discovery of the new antibacterials remains one of the main challenges in modern medicinal chemistry. This study was undertaken to identify novel molecules with antibacterial activity. Materials and Methods: Using our unique double-reporter system, in-house large-scale HTS campaign was conducted for the identification of antibacterial potency of small-molecule compounds. The construction allows us to visually assess the underlying mechanism of action. After the initial HTS and rescreen procedure, luciferase assay, C14-test, determination of MIC value and PrestoBlue test were carried out. Results: HTS rounds and rescreen campaign have revealed the antibacterial activity of a series of Nsubstituted triazolo-azetidines and their isosteric derivatives that has not been reported previously. Primary hit-molecule demonstrated a MIC value of 12.5 µg/mL against E. coli Δ tolC with signs of translation blockage and no SOS-response. Translation inhibition (26%, luciferase assay) was achieved at high concentrations up to 160 µg/mL, while no activity was found using C14-test. The compound did not demonstrate cytotoxicity in the PrestoBlue assay against a panel of eukaryotic cells. Within a series of direct structural analogues bearing the same or bioisosteric scaffold, compound 2 was found to have an improved antibacterial potency (MIC=6.25 µg/mL) close to Erythromycin (MIC=2.5-5 µg/mL) against the same strain. In contrast to the parent hit, this compound was more active and selective, and provided a robust IP position. Conclusion: N-substituted triazolo-azetidine scaffold may be used as a versatile starting point for the development of novel active and selective antibacterial compounds.


2020 ◽  
Vol 20 ◽  
Author(s):  
Wenbin Wu ◽  
Yangmei Zhang ◽  
Xiaowu Li ◽  
Xiang Wang ◽  
Yuan Yuan

Objective: The purpose of this study was to explore the mechanism of the miR-375/XPR1 axis in esophageal squamous cell carcinoma (ESCC) and provide a new idea for targeted therapy of ESCC. Methods: Differentially expressed genes in GEO and TCGA databases were analyzed by bioinformatics. The expression levels of miR-375 and XPR1 mRNA were detected by qRT-PCR. Protein expression of XPR1 was detected by western blot. Bioinformatics analysis and dual luciferase assay were conducted to confirm the targeting relationship between miR-375 and XPR1. The viability, proliferation, migration and invasion of cells in each treatment group were detected by CCK-8, colony formation, wound healing and Transwell assays. Results: Significantly down-regulated miR-375 and remarkably up-regulated XPR1 were observed in ESCC tissue and cells. Overexpression of miR-375 inhibited proliferation, invasion and migration of ESCC cells, and greatly reduced the promoting effect of XPR1 overexpression on cell proliferation, migration and invasion. Dual luciferase assay confirmed that miR-375 targeted and inhibited XPR1 expression in ESCC. Conclusion: These results demonstrate the regulatory role of the miR-375/XPR1 axis in ESCC cells and provide a new potential target for the precise treatment of patients with ESCC.


2019 ◽  
Vol 16 (4) ◽  
pp. 365-372 ◽  
Author(s):  
Qishuai Liu ◽  
Li Wang ◽  
Guizhen Yan ◽  
Weifa Zhang ◽  
Zhigang Huan ◽  
...  

Background: MicroRNAs (miRNA) are known to play a key role in the etiology and treatment of epilepsy through controlling the expression of gene. However, miR-125a-5p in the epilepsy is little known. Epilepsy in rat models was induced by Pentylenetetrazol (PTZ) and miR- 125a-5p profiles in the hippocampus were investigated in our experiment. Also, the relationship between miR-125a-5p and calmodulin-dependent protein kinase IV (CAMK4) was identified and the related mechanism was also illustrated. Methods: The miR-125a-5p mRNA expression levels were evaluated by quantitative real time polymerase chain reaction (qRT-PCR). Western Blot (WB) was used to analyze the CAMK4 protein expression levels. Seizure score, latency and duration were determined based on a Racine scale. The enzyme-linked immunosorbent assay (ELISA) was used to analyze the inflammatory factor expression. The relationship between miR-125a-5p and CAMK4 was detected through dual luciferase assay. Results: Downregulation of miR-125a-5p was observed in the hippocampus of PTZ-induced epilepsy rats. The overexpression of miR-125a-5p attenuated seizure and decreased inflammatory factor level in the hippocampus of PTZ-induced rats. The miR-125a-5p alleviated epileptic seizure and inflammation in PTZ-induced rats by suppressing its target gene, CAMK4. Conclusion: miR-125a-5p may represent a novel therapeutic treatment for PTZ-induced epilepsy by preventing the activation of CAMK4.


2020 ◽  
Vol 17 (5) ◽  
pp. 716-724
Author(s):  
Yan A. Ivanenkov ◽  
Renat S. Yamidanov ◽  
Ilya A. Osterman ◽  
Petr V. Sergiev ◽  
Vladimir A. Aladinskiy ◽  
...  

Background: The key issue in the development of novel antimicrobials is a rapid expansion of new bacterial strains resistant to current antibiotics. Indeed, World Health Organization has reported that bacteria commonly causing infections in hospitals and in the community, e.g. E. Coli, K. pneumoniae and S. aureus, have high resistance vs the last generations of cephalosporins, carbapenems and fluoroquinolones. During the past decades, only few successful efforts to develop and launch new antibacterial medications have been performed. This study aims to identify new class of antibacterial agents using novel high-throughput screening technique. Methods: We have designed library containing 125K compounds not similar in structure (Tanimoto coeff.< 0.7) to that published previously as antibiotics. The HTS platform based on double reporter system pDualrep2 was used to distinguish between molecules able to block translational machinery or induce SOS-response in a model E. coli system. MICs for most active chemicals in LB and M9 medium were determined using broth microdilution assay. Results: In an attempt to discover novel classes of antibacterials, we performed HTS of a large-scale small molecule library using our unique screening platform. This approach permitted us to quickly and robustly evaluate a lot of compounds as well as to determine the mechanism of action in the case of compounds being either translational machinery inhibitors or DNA-damaging agents/replication blockers. HTS has resulted in several new structural classes of molecules exhibiting an attractive antibacterial activity. Herein, we report as promising antibacterials. Two most active compounds from this series showed MIC value of 1.2 (5) and 1.8 μg/mL (6) and good selectivity index. Compound 6 caused RFP induction and low SOS response. In vitro luciferase assay has revealed that it is able to slightly inhibit protein biosynthesis. Compound 5 was tested on several archival strains and exhibited slight activity against gram-negative bacteria and outstanding activity against S. aureus. The key structural requirements for antibacterial potency were also explored. We found, that the unsubstituted carboxylic group is crucial for antibacterial activity as well as the presence of bulky hydrophobic substituents at phenyl fragment. Conclusion: The obtained results provide a solid background for further characterization of the 5'- (carbonylamino)-2,3'-bithiophene-4'-carboxylate derivatives discussed herein as new class of antibacterials and their optimization campaign.


Author(s):  
Shurong Ren ◽  
Qizhen Yue ◽  
Qiubo Wang ◽  
Yanli Zhang ◽  
Bei Zhang

Background: Chronic liver damages from viral infection or alcohol abuse result in liver fibrosis, which is a key pathological event in many types of liver diseases. Discovering new anti-fibrosis agents may provide alternative solutions to manage chronic liver diseases. Methods: We first used CCl4 induced liver fibrosis animal model to evaluate the beneficial effects of Cryptotanshinone (CRY). We next explored target miRNAs regulated by CRY in hepatocytes using microarray. The target miRNA candidate was confirmed with realtime-PCR. We also elucidated the downstream target and pathway directly regulated by the miRNA using luciferase assay, western blotting and Epithelial–Mesenchymal Transition (EMT) markers quantification. Lastly, we confirmed CRY induced expression changes of the target genes in vivo. Results: CRY oral administration markedly alleviated the liver injury caused by CCl4. miRNAs expression profiling and realtime-PCR validation revealed miR-539-3p was directly induced by CRY around 4 folds. The induction of miR-539-3p suppressed SMO expression and antagonized Hedgehog (Hh) pathway. Independently CRY treatment suppressed SMO and inhibited EMT process in hepatocytes. The CRY induced expression changes of both miR-539-3p (~ 2 folds increase) and SMO (~ 60% decrease) in livers were validated in animal model. Conclusion: Our study supported CRY could inhibit liver fibrosis by targeting Hh pathway during EMT. CRY could be used as anti-fibrosis agent candidate for managing chronic liver damages.


Author(s):  
Hongtao Li ◽  
Peng Chen ◽  
Lei Chen ◽  
Xinning Wang

Background: Nuclear factor kappa B (NF-κB) is usually activated in Wilms tumor (WT) cells and plays a critical role in WT development. Objective: The study purpose was to screen a NF-κB inhibitor from natural product library and explore its effects on WT development. Methods: Luciferase assay was employed to assess the effects of natural chemical son NF-κB activity. CCK-8 assay was conducted to assess cell growth in response to naringenin. WT xenograft model was established to analyze the effect of naringenin in vivo. Quantitative real-time PCR and Western blot were performed to examine the mRNA and protein levels of relative genes, respectively. Results: Naringenin displayed significant inhibitory effect on NF-κB activation in SK-NEP-1 cells. In SK-NEP-1 and G-401 cells, naringenin inhibited p65 phosphorylation. Moreover, naringenin suppressed TNF-α-induced p65 phosphorylation in WT cells. Naringenin inhibited TLR4 expression at both mRNA and protein levels in WT cells. CCK-8 staining showed that naringenin inhibited cell growth of the two above WT cells in dose-and time-dependent manner, whereas Toll-like receptor 4 (TLR4) over expression partially reversed the above phenomena. Besides, naringenin suppressed WT tumor growth in dose-and time-dependent manner in vivo. Western blot found that naringenin inhibited TLR4 expression and p65 phosphorylation in WT xenograft tumors. Conclusion: Naringenin inhibits WT development viasuppressing TLR4/NF-κB signaling


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jing Zhou ◽  
Yang Lin ◽  
Xiuhua Kang ◽  
Zhicheng Liu ◽  
Wei Zhang ◽  
...  

Abstract Background Previous reports have identified that human bone marrow mesenchymal stem cell-derived extracellular vesicles (BMSC-EVs) with their cargo microRNAs (miRNAs) are a promising therapeutic approach for the treatment of idiopathic pulmonary fibrosis (IPF). Therefore, we explored whether delivery of microRNA-186 (miR-186), a downregulated miRNA in IPF, by BMSC EVs could interfere with the progression of IPF in a murine model. Methods In a co-culture system, we assessed whether BMSC-EVs modulated the activation of fibroblasts. We established a mouse model of PF to evaluate the in vivo therapeutic effects of BMSC-EVs and determined miR-186 expression in BMSC-EVs by polymerase chain reaction. Using a loss-of-function approach, we examined how miR-186 delivered by BMSC-EVs affected fibroblasts. The putative relationship between miR-186 and SRY-related HMG box transcription factor 4 (SOX4) was tested using luciferase assay. Next, we investigated whether EV-miR-186 affected fibroblast activation and PF by targeting SOX4 and its downstream gene, Dickkopf-1 (DKK1). Results BMSC-EVs suppressed lung fibroblast activation and delayed IPF progression in mice. miR-186 was downregulated in IPF but enriched in the BMSC-EVs. miR-186 delivered by BMSC-EVs could suppress fibroblast activation. Furthermore, miR-186 reduced the expression of SOX4, a target gene of miR-186, and hence suppressed the expression of DKK1. Finally, EV-delivered miR-186 impaired fibroblast activation and alleviated PF via downregulation of SOX4 and DKK1. Conclusion In conclusion, miR-186 delivered by BMSC-EVs suppressed SOX4 and DKK1 expression, thereby blocking fibroblast activation and ameliorating IPF, thus presenting a novel therapeutic target for IPF.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Fangfang Yang ◽  
Hua Wang ◽  
Bianbian Yan ◽  
Tong Li ◽  
Lulu Min ◽  
...  

Abstract The molecular pathogenesis of colorectal cancer (CRC) has been widely investigated in recent years. Accumulating evidence has indicated that microRNA (miRNA) dysregulation participates in the processes of driving CRC initiation and progression. Aberrant expression of miR-1301 has been found in various tumor types. However, its role in CRC remains to be elucidated. In the present study, we identified miR-1301 was enriched in normal colorectal tissues and significantly down-regulated in CRC. Decreased level of miR-1301 strongly correlated with aggressive pathological characteristics, including advanced stage and metastasis. Bioinformatics and dual luciferase assay demonstrated that STAT3 is a direct target of miR-1301. Gain and loss-of-function assays showed that miR-1301 had no effect on cell proliferation. Overexpression of miR-1301 suppressed cell migration and invasion capacity of pSTA3-positive LoVo cells, but not pSTAT3-negative SW480 cells, while inhibition of miR-1301 consistently promoted cell migration and invasion in both cell lines. Additionally, miR-1301 inhibition restored the suppressed migration and invasion of STAT3- knockdown LoVo cells. MiR-1301 functioned as a tumor suppressor to modulate the IL6/STAT3 signaling pathway. In summary, this study highlights the significant role of miR- 1301/STAT3 axis in CRC metastasis.


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