scholarly journals Ultrasound Imaging of Gene Expression in Mammalian Cells

2019 ◽  
Author(s):  
Arash Farhadi ◽  
Gabrielle H. Ho ◽  
Daniel P. Sawyer ◽  
Raymond W. Bourdeau ◽  
Mikhail G. Shapiro
Keyword(s):  
Gene Expression ◽  
Mammalian Cells ◽  
Reporter Genes ◽  
Tissue Imaging ◽  
Cellular Functions ◽  
Cellular Processes ◽  
Deep Tissue Imaging ◽  
And Function ◽  
Expression In Mammalian Cells

ABSTRACTThe study of cellular processes occurring inside intact organisms and the development of cell-based diagnostic and therapeutic agents requires methods to visualize cellular functions such as gene expression in deep tissues. Ultrasound is a widely used biomedical technology enabling deep-tissue imaging with high spatial and temporal resolution. However, no genetically encoded molecular reporters are available to connect ultrasound contrast to gene expression in mammalian cells. To address this limitation, we introduce the first mammalian acoustic reporter genes. Starting with an eleven-gene polycistronic gene cluster derived from bacteria, we engineered a eukaryotic genetic program whose introduction into mammalian cells results in the expression of a unique class of intracellular air-filled protein nanostructures called gas vesicles. The scattering of ultrasound by these nanostructures allows mammalian cells to be visualized at volumetric densities below 0.5%, enables the monitoring of dynamic circuit-driven gene expression, and permits high-resolution imaging of gene expression in living animals. These mammalian acoustic reporter genes enable previously impossible approaches to monitoring the location, viability and function of mammalian cellsin vivo.

scholarly journals Ultrasound imaging of gene expression in mammalian cells

Science ◽  
2019 ◽  
Vol 365 (6460) ◽  
pp. 1469-1475 ◽  
Author(s):  
Arash Farhadi ◽  
Gabrielle H. Ho ◽  
Daniel P. Sawyer ◽  
Raymond W. Bourdeau ◽  
Mikhail G. Shapiro
Keyword(s):  
Gene Expression ◽  
Mammalian Cells ◽  
Reporter Genes ◽  
High Resolution Imaging ◽  
Gas Vesicles ◽  
Cellular Functions ◽  
Cellular Processes ◽  
Ultrasound Contrast ◽  
Resolution Imaging ◽  
Expression In Mammalian Cells

The study of cellular processes occurring inside intact organisms requires methods to visualize cellular functions such as gene expression in deep tissues. Ultrasound is a widely used biomedical technology enabling noninvasive imaging with high spatial and temporal resolution. However, no genetically encoded molecular reporters are available to connect ultrasound contrast to gene expression in mammalian cells. To address this limitation, we introduce mammalian acoustic reporter genes. Starting with a gene cluster derived from bacteria, we engineered a eukaryotic genetic program whose introduction into mammalian cells results in the expression of intracellular air-filled protein nanostructures called gas vesicles, which produce ultrasound contrast. Mammalian acoustic reporter genes allow cells to be visualized at volumetric densities below 0.5% and permit high-resolution imaging of gene expression in living animals.

HMGN proteins play roles in DNA repair and gene expression in mammalian cells

2004 ◽  
Vol 32 (6) ◽  
pp. 918-919 ◽  
Author(s):  
K.L. West
Keyword(s):  
Gene Expression ◽  
Dna Repair ◽  
Knockout Mice ◽  
Mammalian Cells ◽  
High Mobility ◽  
Genetically Engineered ◽  
Expression In Mammalian Cells ◽  
Transcription And Replication

HMGN (high-mobility-group N) family members are vertebrate proteins that unfold chromatin and promote transcription and replication of chromatin templates in vitro. However, their precise roles in vivo have been elusive until recently. This paper summarizes recent advances from studies of Hmgn1 knockout mice and genetically engineered cell lines that are beginning to reveal the diverse roles that HMGN proteins play in DNA repair and transcription within mammalian cells.

scholarly journals Protein manipulation using single copies of short peptide tags in cultured cells and in Drosophila melanogaster

2020 ◽  
Author(s):  
M. Alessandra Vigano ◽  
Clara-Maria Ell ◽  
Manuela MM Kustermann ◽  
Gustavo Aguilar ◽  
Shinya Matsuda ◽  
...  
Keyword(s):  
Cultured Cells ◽  
Single Copy ◽  
Specific Protein ◽  
Cellular Functions ◽  
Cellular Processes ◽  
Peptide Tags ◽  
Genetic Technologies ◽  
Protein Binders ◽  
And Function

AbstractCellular development and specialized cellular functions are regulated processes which rely on highly dynamic molecular interactions among proteins, distributed in all cell compartments. Analysis of these interactions and their mechanisms of action has been one of the main topics in cellular and developmental research over the last fifty years. Studying and understanding the functions of proteins of interest (POIs) has been mostly achieved by their alteration at the genetic level and the analysis of the phenotypic changes generated by these alterations. Although genetic and reverse genetic technologies contributed to the vast majority of information and knowledge we have gathered so far, targeting specific interactions of POIs in a time- and space-controlled manner or analyzing the role of POIs in dynamic cellular processes such as cell migration or cell division would require more direct approaches. The recent development of specific protein binders, which can be expressed and function intracellularly, together with several improvements in synthetic biology techniques, have contributed to the creation of a new toolbox for direct protein manipulations. We selected a number of short tag epitopes for which protein binders from different scaffolds have been developed and tested whether these tags can be bound by the corresponding protein binders in living cells when they are inserted in a single copy in a POI. We indeed find that in all cases, a single copy of a short tag allows protein binding and manipulation. Using Drosophila, we also find that single short tags can be recognized and allow degradation and relocalization of POIs in vivo.

scholarly journals Coordinated genomic control of ciliogenesis and cell movement by RFX2

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Mei-I Chung ◽  
Taejoon Kwon ◽  
Fan Tu ◽  
Eric R Brooks ◽  
Rakhi Gupta ◽  
...  
Keyword(s):  
Gene Expression ◽  
Control Cell ◽  
Cell Movement ◽  
Genomic Analysis ◽  
Apical Surface ◽  
Biological Processes ◽  
Cellular Functions ◽  
Genomic Control ◽  
And Function

The mechanisms linking systems-level programs of gene expression to discrete cell biological processes in vivo remain poorly understood. In this study, we have defined such a program for multi-ciliated epithelial cells (MCCs), a cell type critical for proper development and homeostasis of the airway, brain and reproductive tracts. Starting from genomic analysis of the cilia-associated transcription factor Rfx2, we used bioinformatics and in vivo cell biological approaches to gain insights into the molecular basis of cilia assembly and function. Moreover, we discovered a previously un-recognized role for an Rfx factor in cell movement, finding that Rfx2 cell-autonomously controls apical surface expansion in nascent MCCs. Thus, Rfx2 coordinates multiple, distinct gene expression programs in MCCs, regulating genes that control cell movement, ciliogenesis, and cilia function. As such, the work serves as a paradigm for understanding genomic control of cell biological processes that span from early cell morphogenetic events to terminally differentiated cellular functions.

Optogenetics for gene expression in mammalian cells

2015 ◽  
Vol 396 (2) ◽  
pp. 145-152 ◽  
Author(s):  
Konrad Müller ◽  
Sebastian Naumann ◽  
Wilfried Weber ◽  
Matias D. Zurbriggen
Keyword(s):  
Gene Expression ◽  
Cell Biology ◽  
Mammalian Cells ◽  
Expression System ◽  
Molecular Switches ◽  
Central Research ◽  
Spatiotemporal Resolution ◽  
Cellular Processes ◽  
Recent Developments ◽  
Expression In Mammalian Cells

Abstract Molecular switches that are controlled by chemicals have evolved as central research instruments in mammalian cell biology. However, these tools are limited in terms of their spatiotemporal resolution due to freely diffusing inducers. These limitations have recently been addressed by the development of optogenetic, genetically encoded, and light-responsive tools that can be controlled with the unprecedented spatiotemporal precision of light. In this article, we first provide a brief overview of currently available optogenetic tools that have been designed to control diverse cellular processes. Then, we focus on recent developments in light-controlled gene expression technologies and provide the reader with a guideline for choosing the most suitable gene expression system.

scholarly journals In vivo bioluminescence for tracking cell fate and function

2011 ◽  
Vol 301 (3) ◽  
pp. H663-H671 ◽  
Author(s):  
Patricia E. de Almeida ◽  
Juliaan R. M. van Rappard ◽  
Joseph C. Wu
Keyword(s):  
Gene Expression ◽  
Cell Survival ◽  
Cell Fate ◽  
Mammalian Cells ◽  
Cardiac Injury ◽  
Therapeutic Interventions ◽  
Luciferase Expression ◽  
Physiological Processes ◽  
And Function

Tracking the fate and function of cells in vivo is paramount for the development of rational therapies for cardiac injury. Bioluminescence imaging (BLI) provides a means for monitoring physiological processes in real time, ranging from cell survival to gene expression to complex molecular processes. In mice and rats, BLI provides unmatched sensitivity because of the absence of endogenous luciferase expression in mammalian cells and the low background luminescence emanating from animals. In the field of stem cell therapy, BLI provides an unprecedented means to monitor the biology of these cells in vivo, giving researchers a greater understanding of their survival, migration, immunogenicity, and potential tumorigenicity in a living animal. In addition to longitudinal monitoring of cell survival, BLI is a useful tool for semiquantitative measurements of gene expression in vivo, allowing a better optimization of drug and gene therapies. Overall, this technology not only enables rapid, reproducible, and quantitative monitoring of physiological processes in vivo but also can measure the influences of therapeutic interventions on the outcome of cardiac injuries.

scholarly journals Bend, Push, Stretch: Remarkable Structure and Mechanics of Single Intermediate Filaments and Meshworks

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1960
Author(s):  
K. Tanuj Sapra ◽  
Ohad Medalia
Keyword(s):  
Intermediate Filaments ◽  
Eukaryotic Cell ◽  
Coiled Coils ◽  
Cellular Functions ◽  
Mechanical Pressure ◽  
Mechanical Feature ◽  
Cellular Processes ◽  
Nuclear Lamins ◽  
Filament Networks ◽  
And Function

The cytoskeleton of the eukaryotic cell provides a structural and functional scaffold enabling biochemical and cellular functions. While actin and microtubules form the main framework of the cell, intermediate filament networks provide unique mechanical properties that increase the resilience of both the cytoplasm and the nucleus, thereby maintaining cellular function while under mechanical pressure. Intermediate filaments (IFs) are imperative to a plethora of regulatory and signaling functions in mechanotransduction. Mutations in all types of IF proteins are known to affect the architectural integrity and function of cellular processes, leading to debilitating diseases. The basic building block of all IFs are elongated α-helical coiled-coils that assemble hierarchically into complex meshworks. A remarkable mechanical feature of IFs is the capability of coiled-coils to metamorphize into β-sheets under stress, making them one of the strongest and most resilient mechanical entities in nature. Here, we discuss structural and mechanical aspects of IFs with a focus on nuclear lamins and vimentin.

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