scholarly journals Quantitative Phase Imaging of Spreading Fibroblasts Identifies the Role of Focal Adhesion Kinase in the Stabilization of the Cell Rear

Biomolecules ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1089
Author(s):  
Olga Ramaniuk ◽  
Zuzana Klímová ◽  
Tomáš Groušl ◽  
Tomáš Vomastek
Keyword(s):  
Focal Adhesion Kinase ◽  
Focal Adhesion ◽  
Cell Mass ◽  
Dry Mass ◽  
Cell Polarization ◽  
Phase Imaging ◽  
Quantitative Phase Imaging ◽  
Quantitative Phase ◽  
Cell Front

Cells attaching to the extracellular matrix spontaneously acquire front–rear polarity. This self-organization process comprises spatial activation of polarity signaling networks and the establishment of a protruding cell front and a non-protruding cell rear. Cell polarization also involves the reorganization of cell mass, notably the nucleus that is positioned at the cell rear. It remains unclear, however, how these processes are regulated. Here, using coherence-controlled holographic microscopy (CCHM) for non-invasive live-cell quantitative phase imaging (QPI), we examined the role of the focal adhesion kinase (FAK) and its interacting partner Rack1 in dry mass distribution in spreading Rat2 fibroblasts. We found that FAK-depleted cells adopt an elongated, bipolar phenotype with a high central body mass that gradually decreases toward the ends of the elongated processes. Further characterization of spreading cells showed that FAK-depleted cells are incapable of forming a stable rear; rather, they form two distally positioned protruding regions. Continuous protrusions at opposite sides results in an elongated cell shape. In contrast, Rack1-depleted cells are round and large with the cell mass sharply dropping from the nuclear area towards the basal side. We propose that FAK and Rack1 act differently yet coordinately to establish front–rear polarity in spreading cells.

scholarly journals In Vivo Role of Focal Adhesion Kinase in Regulating Pancreatic  -Cell Mass and Function Through Insulin Signaling, Actin Dynamics, and Granule Trafficking

Diabetes ◽  
2012 ◽  
Vol 61 (7) ◽  
pp. 1708-1718 ◽  
Author(s):  
E. P. Cai ◽  
M. Casimir ◽  
S. A. Schroer ◽  
C. T. Luk ◽  
S. Y. Shi ◽  
...  
Keyword(s):  
Focal Adhesion Kinase ◽  
Focal Adhesion ◽  
Insulin Signaling ◽  
Cell Mass ◽  
Actin Dynamics ◽  
Pancreatic Cell ◽  
And Function

scholarly journals Dry Mass and Cell Cycle Follow-Up from Quantitative Phase Imaging

2014 ◽  
Vol 106 (2) ◽  
pp. 575a
Author(s):  
Julien Savatier ◽  
Sherazade Aknoun ◽  
Pierre Bon ◽  
Lamiae Abdeladim ◽  
Benoit Wattellier ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dry Mass ◽  
Phase Imaging ◽  
Quantitative Phase Imaging ◽  
Quantitative Phase

scholarly journals Measuring three-dimensional dynamics of platelet activation using 3-D quantitative phase imaging

2019 ◽  
Author(s):  
SangYun Lee ◽  
Seongsoo Jang ◽  
YongKeun Park
Keyword(s):  
Platelet Activation ◽  
Three Dimensional ◽  
Dry Mass ◽  
Phase Imaging ◽  
Label Free ◽  
Quantitative Phase Imaging ◽  
Biochemical Alterations ◽  
Quantitative Phase ◽  
Before And After ◽  
Quantitative Manner

AbstractPlatelets, or thrombocytes, are anucleated tiny blood cells with an indispensable contribution to the hemostatic properties of whole blood, detecting injured sites at the surface of blood vessels and forming blood clots. Here, we quantitatively and non-invasively investigated the morphological and biochemical alterations of individual platelets during activation in the absence of exogenous agents by employing 3-D quantitative phase imaging (QPI). By reconstructing 3-D refractive index (RI) tomograms of individual platelets, we investigated alterations in platelet activation before and after the administration of various platelet agonists. Our results showed that while the integrity of collagen-stimulated platelets was preserved despite the existence of a few degranulated platelets with developed pseudopods, platelets stimulated by thrombin or thrombin receptor-activating peptide (TRAP) exhibited significantly lower cellular concentration and dry mass than did resting platelets. Our work provides a means to systematically investigate drug-respondents of individual platelets in a label-free and quantitative manner, and open a new avenue to the study of the activation of platelets.Abstract Figure

scholarly journals Quantitative Phase Imaging Using Deep Learning-Based Holographic Microscope

2021 ◽  
Vol 9 ◽  
Author(s):  
Jianglei Di ◽  
Ji Wu ◽  
Kaiqiang Wang ◽  
Ju Tang ◽  
Ying Li ◽  
...  
Keyword(s):  
Neural Network ◽  
Deep Learning ◽  
Dry Mass ◽  
Learning Technologies ◽  
Digital Holographic Microscopy ◽  
Phase Imaging ◽  
Quantitative Phase Imaging ◽  
Quantitative Phase ◽  
Living Mouse ◽  
Digital Holograms

Digital holographic microscopy enables the measurement of the quantitative light field information and the visualization of transparent specimens. It can be implemented for complex amplitude imaging and thus for the investigation of biological samples including tissues, dry mass, membrane fluctuation, etc. Currently, deep learning technologies are developing rapidly and have already been applied to various important tasks in the coherent imaging. In this paper, an optimized structural convolution neural network PhaseNet is proposed for the reconstruction of digital holograms, and a deep learning-based holographic microscope using above neural network is implemented for quantitative phase imaging. Living mouse osteoblastic cells are quantitatively measured to demonstrate the capability and applicability of the system.

scholarly journals Phase imaging with computational specificity (PICS) for measuring dry mass changes in sub-cellular compartments

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Mikhail E. Kandel ◽  
Yuchen R. He ◽  
Young Jae Lee ◽  
Taylor Hsuan-Yu Chen ◽  
Kathryn Michele Sullivan ◽  
...  
Keyword(s):  
Cell Biology ◽  
Imaging System ◽  
High Specificity ◽  
Dry Mass ◽  
Live Cells ◽  
Phase Imaging ◽  
Label Free ◽  
Quantitative Phase Imaging ◽  
Cell Nuclei ◽  
Quantitative Phase

AbstractDue to its specificity, fluorescence microscopy has become a quintessential imaging tool in cell biology. However, photobleaching, phototoxicity, and related artifacts continue to limit fluorescence microscopy’s utility. Recently, it has been shown that artificial intelligence (AI) can transform one form of contrast into another. We present phase imaging with computational specificity (PICS), a combination of quantitative phase imaging and AI, which provides information about unlabeled live cells with high specificity. Our imaging system allows for automatic training, while inference is built into the acquisition software and runs in real-time. Applying the computed fluorescence maps back to the quantitative phase imaging (QPI) data, we measured the growth of both nuclei and cytoplasm independently, over many days, without loss of viability. Using a QPI method that suppresses multiple scattering, we measured the dry mass content of individual cell nuclei within spheroids. In its current implementation, PICS offers a versatile quantitative technique for continuous simultaneous monitoring of individual cellular components in biological applications where long-term label-free imaging is desirable.

scholarly journals Simultaneous measurement of neurite and neural body mass accumulation via quantitative phase imaging

The Analyst ◽  
2021 ◽  
Author(s):  
Soorya Pradeep ◽  
Tasmia Tasnim ◽  
Huanan Zhang ◽  
Thomas A. Zangle
Keyword(s):  
Body Mass ◽  
Biomass Production ◽  
Simultaneous Measurement ◽  
Neural Differentiation ◽  
Phase Imaging ◽  
Quantitative Phase Imaging ◽  
Quantitative Phase ◽  
Mass Accumulation

Quantitative phase imaging (QPI) used to quantify the mass of soma (cell bodies) and neurites as well as the rates of biomass production due to neurite maturation and formation during neural differentiation.

scholarly journals SAT-604 The Role of the Focal Adhesion Kinase Family in Leptin Receptor Signaling

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Colleen Hadley ◽  
Isin Cakir ◽  
Roger D Cone
Keyword(s):  
Food Intake ◽  
Focal Adhesion Kinase ◽  
Focal Adhesion ◽  
Leptin Receptor ◽  
Kinase Activity ◽  
Cytokine Receptor ◽  
Receptor Signaling ◽  
Kinase Family ◽  
Stat3 Phosphorylation

Abstract Overweight and obesity are global concerns affecting nearly one third of the world population. These conditions are characterized by increased adiposity and are accompanied by a proportional increase in circulating leptin, an anorexigenic adipokine. Leptin is responsible for signaling peripheral energy status to the central nervous system to modulate food intake and energy expenditure. As such, neurons within the hypothalamus expressing the long isoform of leptin receptor (LepRb), a type I cytokine receptor, are primarily responsible for mediating the effects of leptin, which signal predominantly through the JAK2-STAT3 transduction mechanism. STAT3 is a latent transcription factor activated upon phosphorylation, which triggers its homodimerization and nuclear translocation. Evidence, however, for JAK2-independent, STAT3-dependent leptin receptor signaling mechanisms exist. FAK (focal adhesion kinase, Ptk2) and Pyk2 (protein tyrosine kinase 2b, Ptk2b) are a subset of nonreceptor protein tyrosine kinases and comprise the focal adhesion kinase family. FAK and Pyk2 are implicated in the regulation of cytokine receptor signaling. Furthermore, Pyk2 knockout mice have an obesity prone phenotype. Here, we studied the role of the focal adhesion kinases in leptin receptor signaling using genetic and pharmacological approaches. We found that overexpression of Pyk2 or FAK increased STAT3 phosphorylation (activation). Overexpression of a FAK or Pyk2 construct with impaired kinase activity, however, attenuated STAT3 phosphorylation, suggesting the increase in STAT3 phosphorylation is largely dependent upon kinase activity of FAK/Pyk2. Treatment of cells with a small molecule dual inhibitor of FAK and Pyk2 (PF431396) attenuated leptin-induced STAT3 phosphorylation in a mouse hypothalamic cell line. Importantly, this effect is independent of JAK2, as PF treatment of two independent JAK2-deficient cell lines exhibited similar attenuation of leptin-induced STAT3 phosphorylation. To assess the physiological relevance of FAK/Pyk2 in leptin receptor signaling in vivo, we administered PF compound to the lateral ventricle of 24-hour fasted lean wild-type mice followed by peripheral leptin administration. Intracerebroventricular (ICV) administration of PF suppressed the anorectic effect of leptin as evidenced by impaired inhibition of food intake upon refeeding. Accordingly, analysis of total hypothalamic lysates from these mice showed ICV PF impaired leptin-induced STAT3 phosphorylation. Taken together, these data suggest that Pyk2 and/or FAK play a role in leptin signal transduction.

scholarly journals High-speed line-field confocal holographic microscope for quantitative phase imaging

2016 ◽  
Vol 24 (9) ◽  
pp. 9251 ◽  
Author(s):  
Changgeng Liu ◽  
Sebastian Knitter ◽  
Zhilong Cong ◽  
Ikbal Sencan ◽  
Hui Cao ◽  
...  
Keyword(s):  
High Speed ◽  
Phase Imaging ◽  
Quantitative Phase Imaging ◽  
Line Field ◽  
Quantitative Phase
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