scholarly journals Scalable Parallel Manipulation of Single Cells Using Micronozzle Array Integrated with Bidirectional Electrokinetic Pumps

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 442
Author(s):  
Moeto Nagai ◽  
Keita Kato ◽  
Satoshi Soga ◽  
Tuhin Subhra Santra ◽  
Takayuki Shibata
Keyword(s):  
Indium Tin Oxide ◽  
Integration Method ◽  
Single Cells ◽  
Operating Conditions ◽  
Cell Manipulation ◽  
Cellular Functions ◽  
Peak Voltage ◽  
Dc Bias ◽  
Standard Integration

High throughput reconstruction of in vivo cellular environments allows for efficient investigation of cellular functions. If one-side-open multi-channel microdevices are integrated with micropumps, the devices will achieve higher throughput in the manipulation of single cells while maintaining flexibility and open accessibility. This paper reports on the integration of a polydimethylsiloxane (PDMS) micronozzle array and bidirectional electrokinetic pumps driven by DC-biased AC voltages. Pt/Ti and indium tin oxide (ITO) electrodes were used to study the effect of DC bias and peak-to-peak voltage and electrodes in a low conductivity isotonic solution. The flow was bidirectionally controlled by changing the DC bias. A pump integrated with a micronozzle array was used to transport single HeLa cells into nozzle holes. The application of DC-biased AC voltage (100 kHz, 10 Vpp, and VDC: −4 V) provided a sufficient electroosmotic flow outside the nozzle array. This integration method of nozzle and pumps is anticipated to be a standard integration method. The operating conditions of DC-biased AC electrokinetic pumps in a biological buffer was clarified and found useful for cell manipulation.

scholarly journals Roles for RNA export factor, Nxt1, in ensuring muscle integrity and normal RNA expression in Drosophila

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Kevin van der Graaf ◽  
Katia Jindrich ◽  
Robert Mitchell ◽  
Helen White-Cooper
Keyword(s):  
Mrna Export ◽  
Rna Stability ◽  
Muscle Degeneration ◽  
Loss Of Function ◽  
Cellular Functions ◽  
Partial Loss ◽  
Export Pathway ◽  
Pathway Gene ◽  
Rna Export

Abstract The mRNA export pathway is responsible for the transport of mRNAs from the nucleus to the cytoplasm, and thus is essential for protein production and normal cellular functions. A partial loss of function allele of the mRNA export factor Nxt1 in Drosophila shows reduced viability and sterility. A previous study has shown that the male fertility defect is due to a defect in transcription and RNA stability, indicating the potential for this pathway to be implicated in processes beyond the known mRNA transport function. Here we investigate the reduced viability of Nxt1 partial loss of function mutants, and describe a defect in growth and maintenance of the larval muscles, leading to muscle degeneration. RNA-seq revealed reduced expression of a set of mRNAs, particularly from genes with long introns in Nxt1 mutant carcass. We detected differential expression of circRNA, and significantly fewer distinct circRNAs expressed in the mutants. Despite the widespread defects in gene expression, muscle degeneration was rescued by increased expression of the costamere component tn (abba) in muscles. This is the first report of a role for the RNA export pathway gene Nxt1 in the maintenance of muscle integrity. Our data also links the mRNA export pathway to a specific role in the expression of mRNA and circRNA from common precursor genes, in vivo.

In vivo expansion of cells expressing acquired CSF3R mutations in patients with severe congenital neutropenia

Blood ◽  
2009 ◽  
Vol 113 (3) ◽  
pp. 668-670 ◽  
Author(s):  
Manuela Germeshausen ◽  
Karl Welte ◽  
Matthias Ballmaier
Keyword(s):  
Single Cells ◽  
Bone Marrow Failure ◽  
Point Mutations ◽  
Predictive Marker ◽  
Lymphoid Cells ◽  
Lower Percentage ◽  
Severe Congenital Neutropenia ◽  
Congenital Neutropenia ◽  
Bone Marrow Failure Syndrome

Abstract Severe congenital neutropenia (CN) is a rare bone marrow failure syndrome with a high incidence of acute leukemia. In previous studies, we could show that point mutations in the gene for the granulocyte colony-stimulating factor (G-CSF) receptor CSF3R are a highly predictive marker for leukemic development in CN patients. To find out at which stage of hematopoietic development these mutations emerge and how they are propagated during hematopoietic differentiation, we analyzed single cells of different hematopoietic subpopulations from CN patients with CSF3R mutations. We found that CSF3R mutations are not restricted to the myeloid compartment but are also detectable in lymphoid cells, although at a much lower percentage. From our observations, we conclude that CSF3R mutations are acquired in multipotent hematopoietic progenitor cells in CN patients and that they are clonally expanded in myeloid cells expressing the G-CSF receptor due to the growth advantage mediated by the CSF3R mutation.

Corrigendum to “Indium Tin Oxide devices for amperometric detection of vesicular release by single cells” [Biophys. Chem. 162 (2012) 14–21]

2013 ◽  
Vol 171 ◽  
pp. 84-85 ◽  
Author(s):  
Anne Meunier ◽  
Rémy Fulcrand ◽  
François Darchen ◽  
Manon Guille Collignon ◽  
Frédéric Lemaître ◽  
...  
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Single Cells ◽  
Amperometric Detection ◽  
Vesicular Release

Current trends in mathematical modeling of tumor–microenvironment interactions: a survey of tools and applications

2010 ◽  
Vol 235 (4) ◽  
pp. 411-423 ◽  
Author(s):  
Katarzyna A Rejniak ◽  
Lisa J McCawley
Keyword(s):  
Mathematical Modeling ◽  
Protein Interactions ◽  
Computational Models ◽  
Chemical Species ◽  
Tumor Stroma ◽  
Cellular Functions ◽  
Complex Interactions ◽  
Expanding Population

In its simplest description, a tumor is comprised of an expanding population of transformed cells supported by a surrounding microenvironment termed the tumor stroma. The tumor microcroenvironment has a very complex composition, including multiple types of stromal cells, a dense network of various extracellular matrix (ECM) fibers interpenetrated by the interstitial fluid and gradients of several chemical species that either are dissolved in the fluid or are bound to the ECM structure. In order to study experimentally such complex interactions between multiple players, cancer is dissected and considered at different scales of complexity, such as protein interactions, biochemical pathways, cellular functions or whole organism studies. However, the integration of information acquired from these studies into a common description is as difficult as the disease itself. Computational models of cancer can provide cancer researchers with invaluable tools that are capable of integrating the complexity into organizing principles as well as suggesting testable hypotheses. We will focus in this Minireview on mathematical models in which the whole cell is a main modeling unit. We will present a current stage of such cell-focused mathematical modeling incorporating different stromal components and their interactions with growing tumors, and discuss what modeling approaches can be undertaken to complement the in vivo and in vitro experimentation.

An In Vivo Fluorescent Sensor Reveals Intracellular Ins(1,3,4,5)P4Dynamics in Single Cells

2010 ◽  
Vol 49 (12) ◽  
pp. 2150-2153 ◽  
Author(s):  
Reiko Sakaguchi ◽  
Kazuki Tainaka ◽  
Naoko Shimada ◽  
Shun Nakano ◽  
Masafumi Inoue ◽  
...  
Keyword(s):  
Fluorescent Sensor ◽  
Single Cells

scholarly journals Measuring fast gene dynamics in single cells with time-lapse luminescence microscopy

2014 ◽  
Vol 25 (22) ◽  
pp. 3699-3708 ◽  
Author(s):  
Anyimilehidi Mazo-Vargas ◽  
Heungwon Park ◽  
Mert Aydin ◽  
Nicolas E. Buchler
Keyword(s):  
Gene Expression ◽  
Fluorescent Proteins ◽  
Single Cells ◽  
Time Lapse ◽  
Photon Flux ◽  
Luminescence Microscopy ◽  
Cell Cycle Genes ◽  
Light Excitation ◽  
Better Than

Time-lapse fluorescence microscopy is an important tool for measuring in vivo gene dynamics in single cells. However, fluorescent proteins are limited by slow chromophore maturation times and the cellular autofluorescence or phototoxicity that arises from light excitation. An alternative is luciferase, an enzyme that emits photons and is active upon folding. The photon flux per luciferase is significantly lower than that for fluorescent proteins. Thus time-lapse luminescence microscopy has been successfully used to track gene dynamics only in larger organisms and for slower processes, for which more total photons can be collected in one exposure. Here we tested green, yellow, and red beetle luciferases and optimized substrate conditions for in vivo luminescence. By combining time-lapse luminescence microscopy with a microfluidic device, we tracked the dynamics of cell cycle genes in single yeast with subminute exposure times over many generations. Our method was faster and in cells with much smaller volumes than previous work. Fluorescence of an optimized reporter (Venus) lagged luminescence by 15–20 min, which is consistent with its known rate of chromophore maturation in yeast. Our work demonstrates that luciferases are better than fluorescent proteins at faithfully tracking the underlying gene expression.

scholarly journals Visual pH Sensors: From a Chemical Perspective to New Bioengineered Materials

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2952
Author(s):  
Luigi Di Costanzo ◽  
Barbara Panunzi
Keyword(s):  
Ph Monitoring ◽  
Three Dimensional ◽  
Lessons Learned ◽  
Background Information ◽  
Biological Macromolecules ◽  
Ph Sensing ◽  
Ph Sensors ◽  
Cellular Functions ◽  
Metal Organic

Many human activities and cellular functions depend upon precise pH values, and pH monitoring is considered a fundamental task. Colorimetric and fluorescence sensors for pH measurements are chemical and biochemical tools able to sense protons and produce a visible signal. These pH sensors are gaining widespread attention as non-destructive tools, visible to the human eye, that are capable of a real-time and in-situ response. Optical “visual” sensors are expanding researchers’ interests in many chemical contexts and are routinely used for biological, environmental, and medical applications. In this review we provide an overview of trending colorimetric, fluorescent, or dual-mode responsive visual pH sensors. These sensors include molecular synthetic organic sensors, metal organic frameworks (MOF), engineered sensing nanomaterials, and bioengineered sensors. We review different typological chemical entities of visual pH sensors, three-dimensional structures, and signaling mechanisms for pH sensing and applications; developed in the past five years. The progression of this review from simple organic molecules to biological macromolecules seeks to benefit beginners and scientists embarking on a project of pH sensing development, who needs background information and a quick update on advances in the field. Lessons learned from these tools will aid pH determination projects and provide new ways of thinking for cell bioimaging or other cutting-edge in vivo applications.

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