scholarly journals In vivo measurements reveal a single 5’ intron is sufficient to increase protein expression level in C. elegans

2018 ◽  
Author(s):  
Matthew M. Crane ◽  
Bryan Sands ◽  
Christian Battaglia ◽  
Brock Johnson ◽  
Soo Yun ◽  
...  

AbstractIntrons can increase gene expression levels using a variety of mechanisms collectively referred to as Intron Mediated Enhancement (IME). To date, the magnitude of IME has been quantified in human cell culture and plant models by comparing intronless reporter gene expression levels to those of intron-bearing reporter genes in vitro (mRNA, Western Blots, protein activity), using genome editing technologies that lacked full control of locus and copy number. Here, for the first time, we quantified IME in vivo, in terms of protein expression levels, using fluorescent reporter proteins expressed from a single, defined locus in Caenorhabditis elegans. To quantify the magnitude of IME, we developed a microfluidic chip-based workflow to mount and image individual animals, including software for operation and image processing. We used this workflow to systematically test the effects of position, number and sequence of introns on two different proteins, mCherry and mEGFP, driven by two different promoters, vit-2 and hsp-90. We found the three canonical synthetic introns commonly used in C. elegans transgenes increased mCherry protein concentration by approximately 50%. The naturally-occurring introns found in hsp-90 also increased mCherry expression level by about 50%. Furthermore, and consistent with prior results examining mRNA levels, protein activity or phenotypic rescue, we found that a single, natural or synthetic, 5’ intron was sufficient for the full IME effect while a 3’ intron was not. IME was also affected by protein coding sequence (50% for mCherry and 80% for mEGFP) but not strongly affected by promoter 46% for hsp-90 and 54% for the stronger vit-2. Our results show that IME of protein expression in C. elegans is affected by intron position and contextual coding sequence surrounding the introns, but not greatly by promoter strength. Our combined controlled transgenesis and microfluidic screening approach should facilitate screens for factors affecting IME and other intron-dependent processes.

2018 ◽  
Vol 42 (1-2) ◽  
pp. 23-29
Author(s):  
Sayed R. Hosseini-Fard ◽  
Mohsen Khosravi ◽  
Amaneh Yarnazari ◽  
Parisa Hassanpour ◽  
Abdollah Amirfarhangi ◽  
...  

AbstractBackground:The metabolism of cholesteryl esters (CEs) is under the control of a gene network in macrophages. Several genes such asATF3andEGR2are related to cholesterol metabolism.Methods:In this study, theATF3andEGR2gene expression levels were evaluated in differentiated macrophages of subjects undergoing coronary artery angiography [controls (<5% stenosis), patients (>70% stenosis)] after treatment with small dense low density lipoprotein (sdLDL) particles. Monocytes were isolated using a RosetteSep Kit and were differentiated into macrophages using the M-CSF factor. A modified heparin-MgSO4-PEG method was used for the sdLDL preparation. TheATF3andEGR2gene expression levels were measured by the real-time quantitative polymerase chain reaction (RT-qPCR) technique.Results:In contrast with the control group (p=0.4), theATF3expression level reduced significantly in the differentiated macrophages from all patients [single vessel disease (SVD), fold change 17 times, p=0.02; two vessel disease (2VD), fold change 1.5 times, p=0.05; three vessel disease (3VD), fold change 3.5 times, p=0.04]. Also, theEGR2expression level reduced significantly in all groups (p<0.02). The gene fold changes had no significant differences between the patients (p>0.8).Conclusions:We propose that the failure ofATF3gene expression improves the CE synthesis after sdLDL influx. Furthermore, the reducedEGR2gene expression level in the sdLDL-treated groups may be a negative factor in cholesterol homeostasis.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sabrina Borchert ◽  
Pia-Maria Suckrau ◽  
Robert F. H. Walter ◽  
Michael Wessolly ◽  
Elena Mairinger ◽  
...  

Abstract Malignant pleural mesothelioma (MPM) is a rare, but aggressive tumor with dismal prognosis. Platinum-based chemotherapy is regularly used as part of multimodality therapy. The expression of metallothioneins (MT) has been identified as a reason for cisplatin resistance, which often leads to early therapy failure or relapse. Thus, knockdown of MT expression may improve response to cisplatin treatment. The MT gene- and protein expression of the MPM-cell lines MSTO-211H, NCI-H2052 and NCI-H2452 and the human fibroblast cell line MRC-5, as well as their sensitivity to cisplatin treatment have been evaluated. Knockdown of MT1A, 1B and 2A expression was induced by RNA interference. MT expression was measured using quantitative real-time PCR. An in vitro Assay based on enzyme activity was used to detect cell viability, necrosis and apoptosis before and after incubation with cisplatin. MT2A gene expression could be detected in all MPM cell lines, showing the highest expression in NCI-H2452 and NCI-H2052, whereas gene expression levels of MT1A and MT1B were low or absent. The immunohistochemically protein expression of MT-I/II reflect MT2A gene expression levels. Especially for MSTO-211H cell presenting low initial MT2A levels, a strong induction of MT2A expression could be observed during cisplatin treatment, indicating a cell line-specific and platin-dependent adaption mechanism. Additionally, a MT2A-dependent cellular evasion of apoptosis during cisplatin could be observed, leading to three different MT based phenotypes. MSTO-211H cells showed lower apoptosis rates at an increased expression level of MT2A after cisplatin treatment (from sixfold to fourfold). NCI-H2052 cells showed no changes in MT2A expression, while apoptosis rate is the highest (8–12-fold). NCI-H2452 cells showed neither changes in alteration rate of MT2A expression nor changes in apoptosis rates, indicating an MT2A-independent resistance mechanism. Knockdown of MT2A expression levels resulted in significantly induced apoptotic rates during cisplatin treatment with strongest induction of apoptosis in each of the MPM cell lines, but in different markedness. A therapeutic meaningful effect of MT2A knockdown and subsequent cisplatin treatment could be observed in MSTO-211H cells. The present study showed MT2A to be part of the underlying mechanism of cisplatin resistance in MPM. Especially in MSTO-211H cells we could demonstrate major effects by knockdown of MT2A expression, verifying our hypothesis of an MT driven resistance mechanism. We could prove the inhibition of MT2A as a powerful tool to boost response rates to cisplatin-based therapy in vitro. These data carry the potential to enhance the clinical outcome and management of MPM in the future.


2019 ◽  
Vol 20 (3) ◽  
pp. 506 ◽  
Author(s):  
Pei-Lin Shao ◽  
Shun-Cheng Wu ◽  
Zih-Yin Lin ◽  
Mei-Ling Ho ◽  
Chung-Hwan Chen ◽  
...  

Simvastatin (SVS) promotes the osteogenic differentiation of mesenchymal stem cells (MSCs) and has been studied for MSC-based bone regeneration. However, the mechanism underlying SVS-induced osteogenesis is not well understood. We hypothesize that α5 integrin mediates SVS-induced osteogenic differentiation. Bone marrow MSCs (BMSCs) derived from BALB/C mice, referred to as D1 cells, were used. Alizarin red S (calcium deposition) and alkaline phosphatase (ALP) staining were used to evaluate SVS-induced osteogenesis of D1 cells. The mRNA expression levels of α5 integrin and osteogenic marker genes (bone morphogenetic protein-2 (BMP-2), runt-related transcription factor 2 (Runx2), collagen type I, ALP and osteocalcin (OC)) were detected using quantitative real-time PCR. Surface-expressed α5 integrin was detected using flow cytometry analysis. Protein expression levels of α5 integrin and phosphorylated focal adhesion kinase (p-FAK), which is downstream of α5 integrin, were detected using Western blotting. siRNA was used to deplete the expression of α5 integrin in D1 cells. The results showed that SVS dose-dependently enhanced the gene expression levels of osteogenic marker genes as well as subsequent ALP activity and calcium deposition in D1 cells. Upregulated p-FAK was accompanied by an increased protein expression level of α5 integrin after SVS treatment. Surface-expressed α5 integrin was also upregulated after SVS treatment. Depletion of α5 integrin expression significantly suppressed SVS-induced osteogenic gene expression levels, ALP activity, and calcium deposition in D1 cells. These results identify a critical role of α5 integrin in SVS-induced osteogenic differentiation of BMSCs, which may suggest a therapeutic strategy to modulate α5 integrin/FAK signaling to promote MSC-based bone regeneration.


2019 ◽  
Vol 68 (2) ◽  
pp. 79-86
Author(s):  
Natalia Yu. Shved ◽  
Olga V. Malysheva ◽  
Natalia S. Osinovskaya ◽  
Arseniy S. Molotkov ◽  
Anna A. Tsypurdeyeva ◽  
...  

Hypothesis/aims of study. Endometriosis is one of the most pressing problems of gynecology. Clarifying the expression of the estrogen receptor (ESR1) and the progesterone receptor (PGR) genes and polymorphisms in the aromatase (CYP19A1) gene in endometriosis will expand the understanding of the pathogenesis of the disease and the causes of resistance to its therapy. The objective of this study was to conduct a comparative analysis of mRNA expression of PGR, ESR1 and CYP19A1 genes in paired samples of the eutopic endometrium and peritoneal endometrioid lesions in order to search for predictive markers of response to hormonal therapy. In the future, this may allow personalizing the selection of hormonal preparations for the treatment of endometriosis. Study design, materials and methods. Reverse transcription real-time PCR made it possible to evaluate CYP19A1, PGR and ESR1 gene expression levels in studied tissue samples from 22 patients with endometriosis and 9 women in the comparison group. Results. Quantitative analysis revealed a high heterogeneity in the expression level of the studied genes, in both the endometrium and endometrioid lesions from patients with endometriosis. In the endometrium of patients in the comparison group, the heterogeneity of the expression level was observed only for the ESR1 gene. Conclusion. Our findings suggest a high variability in CYP19A1, ESR1 and PGR gene expression levels in the endometrium and peritoneal foci in patients with endometriosis. This information indicates the need for an individual approach to prescribing targeted therapy, since it is obvious that the effect of treatment will depend primarily on the availability of a therapeutic target in a particular patient. The absence of a typical expression pattern for each of the genes in patients with endometriosis indicates the heterogeneity of the disease and the need to develop a molecular classification of this common pathology.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4888-4888
Author(s):  
Csongor Kiss ◽  
Katalin Gyurina ◽  
Gábor Kiss ◽  
Silvia Bresolin ◽  
Zsuzsa Hevessy ◽  
...  

Abstract Using multiparameter flow cytometry, Western blot, ELISA and laser scanning microscopy, leukemic B-cell progenitor lymphoblasts were identified as a novel expression site of coagulation factor XIII subunit A (FXIIIA) (Kiss et al Thromb Haemost 2006). Three-year overall survival (OS) of children with FXIIIA-positive acute lymphoblastic leukemia (ALL) was significantly higher (87%) than 3-yr OS of patients with FXIIIA-negative ALL (65%). Here we report on gene expression profiles (GEP) associated with FXIIIA-positive vs. FXIIIA–negative childhood (ch)ALL. Finnally, the expression levels of F13A1 gene in cytogenetic subgroups were investigated. GEP of 11 FXIIIA-positive and 9 FXIIIA-negative samples of patients treated at the Department of Hematology-Oncology, University of Debrecen was investigated using HG-U 133 plus 2.0 Affymetrix Platform Array. Expression sequence tags (EST) characterized by expression levels with at least 2 logs difference among FXIIIA-positive vs. FXIIIA-negative samples were selected and validated with real-time quantitative PCR. Extending the analysis, we have searched the database containing GEPs of 317 children with ALL treated at the Division of Hemato-Oncology, Department of Women’s and Children’s Health, University of Padova, using R package and Partek Genomic Suite softwares. FXIIIA-positive and FXIIIA-negative samples exhibited a characteristically different GEP. In the FXIIIA-positive samples one of the overexpressed genes was F13A1. FXIIIA-negative samples contained two characteristic groups of overexpressed genes. One of these consisted of genes participating in B-cell development: EBF1, IKZF1 and PAX5. The second set consisted of genes encoding for tyrosine kinases: JAK1, JAK3, NC07523, NC08002, NC06523, NC08345 and for serine-threonine kinase NC00027. In contrast, FXIIIA-positive samples contained only two overexpressed tyrosine kinases: C-KIT and JAK2. A wide variation of F13A1 expression levels of the 317 Padova patients was observed. Since expression level of FXIIIA protein of these patients has not been determined, we have arbitrarily defined F13A1 gene expression levels below 106 as “low” and gene expression levels exceeding 109 as “high”. Considering these two groups, we have investigated the distribution of F13A1 expression among the known cytogenetic subgroups of ALL. Low F13A1 expression was prevalent among “B-other” samples, high F13A1 expression was associated with t(1;19). The pattern of overexpressed ESTs, accumulation of low F13A1 expressing samples in the “B-other” cytogenetic group of ALL and the unfavorable disease outcome of FXIIIA-negative cases may suggest a possible overlap between FXIIIA-negative ALL and BCR-ABL1-like ALL identified recently in the “B-other” group. The nature and extent of this overlap will be investigated prospectively in the BFM ALL-IC 2009 clinical trial. In contrast, high expression levels of F13A1 accumulated preferentially within the t(1;19) genetic group, associated with a good prognosis. Detection of FXIIIA expression by flow cytometry may offer an easy and non-expensive tool for defining new prognostic subpopulations of ALL. Grant support TÁMOP 4.2.2.A-11/1/KONV-2012-0025 project (CK, KG, HZ, IG, IS and JK). The project is co-financed by the European Union and the European Social Fund and the AIRC (Associazione Italiana Ricerca su Cancro; SB) project. Disclosures: No relevant conflicts of interest to declare.


2019 ◽  
Vol 60 (7) ◽  
pp. 1471-1486 ◽  
Author(s):  
Zefeng Wu ◽  
Jing Tang ◽  
Junjie Zhuo ◽  
Yuhan Tian ◽  
Feiyang Zhao ◽  
...  

Abstract Chromatin accessibility and post-transcriptional histone modifications play important roles in gene expression regulation. However, little is known about the joint effect of multiple chromatin modifications on the gene expression level in plants, despite that the regulatory roles of individual histone marks such as H3K4me3 in gene expression have been well-documented. By using machine-learning methods, we systematically performed gene expression level prediction based on multiple chromatin modifications data in Arabidopsis and rice. We found that as few as four histone modifications were sufficient to yield good prediction performance, and H3K4me3 and H3K36me3 being the top two predictors with known functions related to transcriptional initiation and elongation, respectively. We demonstrated that the predictive powers differed between protein-coding and non-coding genes as well as between CpG-enriched and CpG-depleted genes. We also showed that the predictive model trained in one tissue or species could be applied to another tissue or species, suggesting shared underlying mechanisms. More interestingly, the gene expression levels of conserved orthologs are easier to predict than the species-specific genes. In addition, chromatin state of distal enhancers was moderately correlated to gene expression but was dispensable if given the chromatin features of the proximal regions of genes. We further extended the analysis to transcription factor (TF) binding data. Strikingly, the combinatorial effects of only a few TFs were roughly fit to gene expression levels in Arabidopsis. Overall, by using quantitative modeling, we provide a comprehensive and unbiased perspective on the epigenetic and TF-mediated regulation of gene expression in plants.


2018 ◽  
Vol 12 (02.1) ◽  
pp. 14S
Author(s):  
Bassam El-Hafi ◽  
Sari Shawki Rasheed ◽  
Noor A Salloum ◽  
Antoine Abou Fayad ◽  
George F Araj ◽  
...  

Introduction: The range of antimicrobial agents used to treat bacterial infections is becoming limited with the constant increase in antimicrobial resistance (AMR). Several genetic factors underlie AMR, including β-lactamase-encoding genes such as blaCTXM-15 that confers resistance to third-generation cephalosporins, and blaOXA-48, blaNDM-1, and blaKPC-2 that confer resistance to carbapenems. Remaining treatment approaches for such resistant infections include antimicrobial combination therapy and the use of β-lactamase inhibitors. This study assesses the molecular effects of such treatment approaches on antimicrobial resistant Enterobacteriaceae clinical isolates in vitro and in vivo. Methodology: Nine clinical Enterobacteriaceae isolates were included in the study. One harboring blaCTXM-15, one harboring blaOXA-48, one harboring blaKPC-2, two harboring blaNDM-1 and blaCTXM-15, and four harboring blaOXA-48 and blaCTXM-15. Minimal inhibitory concentrations were determined for carbapenems with β-lactamase inhibitors: avibactam, Ca-EDTA, and relebactam. Synergism between antibiotic combinations was determined by double disc diffusion when using colistin with several antibiotics. In vitro and in vivo gene expression levels were done on these combinations with and without inhibitors. Results: The use of meropenem, imipenem, and ertapenem with the selected β-lactamase inhibitors restored isolate susceptibility in 100%, 87.5%, and 25% of the cases, respectively. Antimicrobial synergism was mostly detected between colistin and meropenem, fosfomycin, or tigecycline. Survival studies revealed the survival of most mice receiving antimicrobial combination therapy with inhibitors as compared to the controls. Overall gene expression levels of resistance genes were variable depending on treatment. Conclusions: The threat of antibiotic resistant bacterial infections remains viable; however, different approaches to therapy are available.


2020 ◽  
Author(s):  
Ghasem Ghasempour ◽  
Fahimeh Zamani-Garmsiri ◽  
Asghar Mohammadi ◽  
Mohammad Najafi

Abstract Background and Aims: Some saturated fatty acids are known to involve in atherosclerosis through different biologic pathways. The aim of this study was to investigate the effects of palmitic acid on the HCK gene and protein expression levels in vascular smooth muscle cells (VSMCs). Methods and Results: The cells were treated with palmitic acid (0.5 mM, 24 hours) on the cell viability assays. The HCK gene and protein expression levels were measured by real time q-PCR and western blot techniques, respectively. Oil Red O staining method was used to determine the intracellular lipid values. The HCK gene expression level was increased significantly in the PA-treated VSMCs (P 0.02). The total and phosphorylated HCK (p-HCK) protein expression levels increased in VSMCs. However, there was a significant increase in p-HCK value (P 0.001). Conclusion: The results showed that the palmitic acid increases p-HCK function so that it may affect the VSMC proliferation.


2011 ◽  
Vol 21 (5) ◽  
pp. 707-717 ◽  
Author(s):  
V. Grishkevich ◽  
T. Hashimshony ◽  
I. Yanai

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