Transposon Insertions in the Promoter of the Zea mays a1 Gene Differentially Affect Transcription by the Myb Factors P and C1

Abstract The understanding of control of gene regulation in higher eukaryotes relies heavily on results derived from non-in vivo studies, but rarely can the significance of these approximations be established in vivo. Here, we investigated the effect of Mutator and Spm insertions on the expression of the flavonoid biosynthetic gene a1, independently regulated by the transcription factors C1 and P. The a1-mum2 and a1-m2 alleles carry Mu1 and Spm insertions, respectively, in a cis-element (ARE) of unknown function located between the P- and C1-binding sites. We show that the insertions of Mu1 and Spm similarly influence the expression of a1 controlled by C1 or P. The P-controlled a1 expression in a1-m2 is Spm dependent, and the mutant phenotype of a1-mum2 is suppressed in the pericarp in the absence of the autonomous MuDR element. Footprints within the ARE affect the regulation of a1 by C1 and P differently, providing evidence that these factors control a1 expression using distinct cis-acting regulatory elements. Together, our findings contribute significantly to one of the best-described plant regulatory systems, while stressing the need to complement with in vivo experiments current approaches used for the study of control of gene expression.

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ANTITUMOR EFFECT OF COLLOIDAL SILVER BISILICATE IN EXPERIMENTAL IN VITRO AND IN VIVO STUDIES

Problems in oncology ◽

10.37469/0507-3758-2019-65-5-760-765 ◽

2019 ◽

Vol 65 (5) ◽

pp. 760-765

Author(s):

Margarita Tyndyk ◽

Irina Popovich ◽

A. Malek ◽

R. Samsonov ◽

N. Germanov ◽

...

Keyword(s):

Antitumor Activity ◽

Tumor Growth ◽

Tumor Cells ◽

Human Tumor ◽

Significant Inhibition ◽

In Vivo Studies ◽

Ehrlich Carcinoma ◽

In Vivo Experiments

The paper presents the results of the research on the antitumor activity of a new drug - atomic clusters of silver (ACS), the colloidal solution of nanostructured silver bisilicate Ag6Si2O7 with particles size of 1-2 nm in deionized water. In vitro studies to evaluate the effect of various ACS concentrations in human tumor cells cultures (breast cancer, colon carcinoma and prostate cancer) were conducted. The highest antitumor activity of ACS was observed in dilutions from 2.7 mg/l to 5.1 mg/l, resulting in the death of tumor cells in all studied cell cultures. In vivo experiments on transplanted Ehrlich carcinoma model in mice consuming 0.75 mg/kg ACS with drinking water revealed significant inhibition of tumor growth since the 14th day of experiment (maximally by 52% on the 28th day, p < 0.05) in comparison with control. Subcutaneous injections of 2.5 mg/kg ACS inhibited Ehrlich's tumor growth on the 7th and 10th days of the experiment (p < 0.05) as compared to control.

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The Challenging Melanoma Landscape: From Early Drug Discovery to Clinical Approval

Cells ◽

10.3390/cells10113088 ◽

2021 ◽

Vol 10 (11) ◽

pp. 3088

Author(s):

Mariana Matias ◽

Jacinta O. Pinho ◽

Maria João Penetra ◽

Gonçalo Campos ◽

Catarina Pinto Reis ◽

...

Keyword(s):

Therapeutic Potential ◽

Drug Evaluation ◽

Three Dimensional ◽

Experimental Models ◽

In Vivo Studies ◽

Murine Models ◽

In Vivo Experiments ◽

Novel Therapeutic Strategies

Melanoma is recognized as the most dangerous type of skin cancer, with high mortality and resistance to currently used treatments. To overcome the limitations of the available therapeutic options, the discovery and development of new, more effective, and safer therapies is required. In this review, the different research steps involved in the process of antimelanoma drug evaluation and selection are explored, including information regarding in silico, in vitro, and in vivo experiments, as well as clinical trial phases. Details are given about the most used cell lines and assays to perform both two- and three-dimensional in vitro screening of drug candidates towards melanoma. For in vivo studies, murine models are, undoubtedly, the most widely used for assessing the therapeutic potential of new compounds and to study the underlying mechanisms of action. Here, the main melanoma murine models are described as well as other animal species. A section is dedicated to ongoing clinical studies, demonstrating the wide interest and successful efforts devoted to melanoma therapy, in particular at advanced stages of the disease, and a final section includes some considerations regarding approval for marketing by regulatory agencies. Overall, considerable commitment is being directed to the continuous development of optimized experimental models, important for the understanding of melanoma biology and for the evaluation and validation of novel therapeutic strategies.

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Transducing positional information to the Hox genes: critical interaction of cdx gene products with position-sensitive regulatory elements

Development ◽

10.1242/dev.125.22.4349 ◽

1998 ◽

Vol 125 (22) ◽

pp. 4349-4358 ◽

Cited By ~ 4

Author(s):

J. Charite ◽

W. de Graaff ◽

D. Consten ◽

M.J. Reijnen ◽

J. Korving ◽

...

Keyword(s):

Binding Sites ◽

Hox Genes ◽

Regulatory Element ◽

Ectopic Expression ◽

Positional Information ◽

Regulatory Elements ◽

Gene Products ◽

Anteroposterior Patterning

Studies of pattern formation in the vertebrate central nervous system indicate that anteroposterior positional information is generated in the embryo by signalling gradients of an as yet unknown nature. We searched for transcription factors that transduce this information to the Hox genes. Based on the assumption that the activity levels of such factors might vary with position along the anteroposterior axis, we devised an in vivo assay to detect responsiveness of cis-acting sequences to such differentially active factors. We used this assay to analyze a Hoxb8 regulatory element, and detected the most pronounced response in a short stretch of DNA containing a cluster of potential CDX binding sites. We show that differentially expressed DNA binding proteins are present in gastrulating embryos that bind to these sites in vitro, that cdx gene products are among these, and that binding site mutations that abolish binding of these proteins completely destroy the ability of the regulatory element to drive regionally restricted expression in the embryo. Finally, we show that ectopic expression of cdx gene products anteriorizes expression of reporter transgenes driven by this regulatory element, as well as that of the endogenous Hoxb8 gene, in a manner that is consistent with them being essential transducers of positional information. These data suggest that, in contrast to Drosophila Caudal, vertebrate cdx gene products transduce positional information directly to the Hox genes, acting through CDX binding sites in their enhancers. This may represent the ancestral mode of action of caudal homologues, which are involved in anteroposterior patterning in organisms with widely divergent body plans and modes of development.

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How Does the Selection of Laboratory Mice Affect the Results of Physiological Distribution of Radiopharmaceuticals?

Current Radiopharmaceuticals ◽

10.2174/1874471014666210528124953 ◽

2021 ◽

Vol 14 ◽

Author(s):

Urszula Karczmarczyk ◽

Piotr Ochniewicz ◽

Ewa Laszuk ◽

Kamil Tomczyk ◽

Piotr Garnuszek

Keyword(s):

Quality Control ◽

Statistical Significance ◽

The United States ◽

Radioactive Isotopes ◽

In Vivo Studies ◽

P Value ◽

Preclinical Studies ◽

In Vivo Experiments ◽

Physicochemical Methods

Background: The choice of mice strain can significantly influence the physiological distribution and may lead to an inadequate assessment of the radiopharmaceutical properties. Objective: This work aims to present how the legal requirements that apply to radiopharmaceuticals contained in the various guidelines determine the choice of the mouse strain for quality control and preclinical studies and affect the results of physiological distribution. Methods: Swiss and BALB/c mice were chosen as commonly used strains in experiments for research and quality control purposes. Radiopharmaceuticals, i.e., preparations containing one or more radioactive isotopes in their composition, are subject to the same legal regulations at every stage of the research, development and routine quality control as all other medicines. Therefore, in vivo experiments are to be carried out to confirm the pharmacological properties and safety. Moreover, if a radiopharmaceutical's chemical structure is unknown or complex and impossible to be determined by physicochemical methods, an analysis of physiological distribution in a rodent animal model needs to be performed. Results: In our studies, thirty-six mice (Swiss n=18, BALB/c n=18) were randomly divided into six groups and injected with the following radiopharmaceuticals: [99mTc]Tc-Colloid, [99mTc]Tc-DTPA and [99mTc]Tc-EHIDA. Measurement of physiological distribution was conducted following the requirements of European Pharmacopoeia (Ph. Eur.) monograph 0689, internal instructions and the United States Pharmacopeia (USP) monograph, respectively. Additionally, at preclinical studies, ten mice (Swiss n=5, BALB/c n=5) were injected with the new tracer [99mTc]Tc-PSMA-T4, and its physiological distribution has been compared. The p-value <0.05 proved the statistical significance of the radiopharmaceutical physiological distribution. Conclusion: We claim that mice strain choice can significantly influence the physiological distribution and may lead to inaccurate quality control results and incomprehensible interpretation of the results from preclinical in vivo studies of a new radiopharmaceutical.

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Effect of Resveratrol on In Vitro and In Vivo Models of Diabetic Retinophathy: A Systematic Review

International Journal of Molecular Sciences ◽

10.3390/ijms20143503 ◽

2019 ◽

Vol 20 (14) ◽

pp. 3503 ◽

Cited By ~ 4

Author(s):

Mario D. Toro ◽

Katarzyna Nowomiejska ◽

Teresio Avitabile ◽

Robert Rejdak ◽

Sarah Tripodi ◽

...

Keyword(s):

Diabetic Retinopathy ◽

Risk Of Bias ◽

In Vivo Studies ◽

Exclusion Criteria ◽

In Vivo Models ◽

In Vivo Experiments ◽

Retinal Pathology ◽

Full Text Review

A large number of preclinical studies suggest the involvement of resveratrol in the prevention and treatment of eye diseases induced by oxidative stress and inflammation. We tested the hypothesis that resveratrol influences many pathways of in vitro and in vivo models of diabetic retinopathy through a systematic literature review of original articles. The review was conducted in accordance with the PRISMA guidelines. A literature search of all original articles published until April 2019 was performed. The terms “resveratrol” in combination with “retina”, “retinal pathology”, “diabetic retinopathy” and “eye” were searched. Possible biases were identified with the adopted SYRCLE’s tool. Eighteen articles met inclusion/exclusion criteria for full-text review. Eleven of them included in vitro experiments, 11 studies reported in vivo data and 3 studies described both in vitro and in vivo experiments. Most of the in vivo studies did not include data that would allow exclusion of bias risks, according to SYRCLE’s risk of bias tool. Both in vitro and in vivo data suggest anti-apoptotic, anti-inflammatory and anti-oxidative actions of resveratrol in models of diabetic retinopathy. However, results on its anti-angiogenic effects are contradictory and need more rigorous studies.

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A Novel Cys2His2 Zinc Finger Homolog of AZF1 Modulates Holocellulase Expression in Trichoderma reesei

mSystems ◽

10.1128/msystems.00161-19 ◽

2019 ◽

Vol 4 (4) ◽

Cited By ~ 4

Author(s):

Amanda Cristina Campos Antonieto ◽

Karoline Maria Vieira Nogueira ◽

Renato Graciano de Paula ◽

Luísa Czamanski Nora ◽

Murilo Henrique Anzolini Cassiano ◽

...

Keyword(s):

Trichoderma Reesei ◽

Filamentous Fungi ◽

Plant Cell Wall ◽

Plant Biomass ◽

Regulatory Elements ◽

Biomass Degradation ◽

Control Of Gene Expression ◽

Content Type ◽

Encoding Genes

ABSTRACT Filamentous fungi are remarkable producers of enzymes dedicated to the degradation of sugar polymers found in the plant cell wall. Here, we integrated transcriptomic data to identify novel transcription factors (TFs) related to the control of gene expression of lignocellulosic hydrolases in Trichoderma reesei and Aspergillus nidulans. Using various sets of differentially expressed genes, we identified some putative cis-regulatory elements that were related to known binding sites for Saccharomyces cerevisiae TFs. Comparative genomics allowed the identification of six transcriptional factors in filamentous fungi that have corresponding S. cerevisiae homologs. Additionally, a knockout strain of T. reesei lacking one of these TFs (S. cerevisiae AZF1 homolog) displayed strong reductions in the levels of expression of several cellulase-encoding genes in response to both Avicel and sugarcane bagasse, revealing a new player in the complex regulatory network operating in filamentous fungi during plant biomass degradation. Finally, RNA sequencing (RNA-seq) analysis showed the scope of the AZF1 homologue in regulating a number of processes in T. reesei, and chromatin immunoprecipitation-quantitative PCR (ChIP-qPCR) provided evidence for the direct interaction of this TF in the promoter regions of cel7a, cel45a, and swo. Therefore, we identified here a novel TF which plays a positive effect in the expression of cellulase-encoding genes in T. reesei. IMPORTANCE In this work, we used a systems biology approach to map new regulatory interactions in Trichoderma reesei controlling the expression of genes encoding cellulase and hemicellulase. By integrating transcriptomics related to complex biomass degradation, we were able to identify a novel transcriptional regulator which is able to activate the expression of these genes in response to two different cellulose sources. In vivo experimental validation confirmed the role of this new regulator in several other processes related to carbon source utilization and nutrient transport. Therefore, this work revealed novel forms of regulatory interaction in this model system for plant biomass deconstruction and also represented a new approach that could be easy applied to other organisms.

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Rcs and PhoPQ Regulatory Overlap in the Control of Salmonella enterica Virulence

Journal of Bacteriology ◽

10.1128/jb.00640-07 ◽

2007 ◽

Vol 189 (18) ◽

pp. 6635-6644 ◽

Cited By ~ 41

Author(s):

Clara B. García-Calderón ◽

Josep Casadesús ◽

Francisco Ramos-Morales

Keyword(s):

Escherichia Coli ◽

Signal Transduction ◽

Salmonella Enterica ◽

In Vivo Studies ◽

Genetic Screens ◽

Signal Transduction System ◽

Constitutive Activation ◽

Regulatory Systems ◽

Serovar Typhimurium

ABSTRACT Genetic screens based on the use of MudJ-generated lac fusions permitted the identification of novel genes regulated by the Rcs signal transduction system in Salmonella enterica serovar Typhimurium. Besides genes that are also found in the Escherichia coli genome, our screens identified Salmonella-specific genes regulated by RcsB, including bapA, siiE, srfA, and srfB. Here we show that the srfABC operon is negatively regulated by RcsB and by PhoP. In vivo studies using mutants with constitutive activation of the Rcs and/or PhoPQ system suggested that there is an overlap between these regulatory systems in the control of Salmonella virulence.

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Assessing Visual Exploratory Activity of Athletes in Virtual Reality Using Head Motion Characteristics

Sensors ◽

10.3390/s21113728 ◽

2021 ◽

Vol 21 (11) ◽

pp. 3728

Author(s):

Markus Wirth ◽

Sebastian Kohl ◽

Stefan Gradl ◽

Rosanna Farlock ◽

Daniel Roth ◽

...

Keyword(s):

Virtual Reality ◽

Expert Knowledge ◽

Body Movement ◽

Assessment Method ◽

Exploratory Activity ◽

In Vivo Studies ◽

Future Research ◽

Performance Factors ◽

In Vivo Experiments

Maximizing performance success in sports is about continuous learning and adaptation processes. Aside from physiological, technical and emotional performance factors, previous research focused on perceptual skills, revealing their importance for decision-making. This includes deriving relevant environmental information as a result of eye, head and body movement interaction. However, to evaluate visual exploratory activity (VEA), generally utilized laboratory settings have restrictions that disregard the representativeness of assessment environments and/or decouple coherent cognitive and motor tasks. In vivo studies, however, are costly and hard to reproduce. Furthermore, the application of elaborate methods like eye tracking are cumbersome to implement and necessitate expert knowledge to interpret results correctly. In this paper, we introduce a virtual reality-based reproducible assessment method allowing the evaluation of VEA. To give insights into perceptual-cognitive processes, an easily interpretable head movement-based metric, quantifying VEA of athletes, is investigated. Our results align with comparable in vivo experiments and consequently extend them by showing the validity of the implemented approach as well as the use of virtual reality to determine characteristics among different skill levels. The findings imply that the developed method could provide accurate assessments while improving the control, validity and interpretability, which in turn informs future research and developments.

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Hepatic transcription of the acute-phase alpha 1-inhibitor III gene is controlled by a novel combination of cis-acting regulatory elements.

Molecular and Cellular Biology ◽

10.1128/mcb.10.7.3483 ◽

1990 ◽

Vol 10 (7) ◽

pp. 3483-3491 ◽

Cited By ~ 9

Author(s):

L J Abraham ◽

A D Bradshaw ◽

B R Shiels ◽

W Northemann ◽

G Hudson ◽

...

Keyword(s):

Binding Sites ◽

Transcriptional Start Site ◽

Regulatory Elements ◽

Nuclear Factor ◽

Base Pairs ◽

Cis Acting ◽

Expression Studies ◽

Positive Regulators ◽

Flanking Region ◽

Related Proteins

mRNA coding for the abundant broad-range plasma proteinase inhibitor alpha 1-inhibitor III (alpha 1I3) was detected only in rat liver, while mRNA for the related proteins alpha 1-macroglobulin and alpha 2-macroglobulin was also found in a variety of nonhepatic tissues. cis-Acting control elements necessary for the hepatic transcription of alpha 1I3 were mapped by transfection and expression studies of control-region constructs in cultured hepatic and nonhepatic cells. The promoter-proximal 5'-flanking region contained four control elements, I to IV, located between -109 and -196 base pairs upstream of the transcriptional start site relevant for the hepatic transcription of this gene. Elements II and III were essential, and I and IV exerted strong modulatory effects. Elements I to III acted as positive regulators, and IV acted as a negative element. Element II contained the sequence TGGCA and is probably a binding site for a nuclear factor related to the known transcription factor NF1. The other three elements did not resemble consensus binding sites for known transcription factors that are involved in the hepatocyte-specific transcription of other well-characterized plasma protein genes, such as the prototype factor HNF-1. Thus, the alpha 1I3 gene achieves its highly hepatocyte-specific transcription through a novel combination of cis-acting control elements and trans-acting factors.

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