scholarly journals Graphene oxide-enhanced cytoskeleton imaging and mitosis tracking

2017 ◽  
Vol 53 (23) ◽  
pp. 3373-3376 ◽  
Author(s):  
Qian-Ru Li ◽  
Jin-Biao Jiao ◽  
Li-Li Li ◽  
Xiao-Peng He ◽  
Yi Zang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Live Cells ◽  
Peptide Probe ◽  
Dynamic Tracking ◽  
A Cell

Graphene oxide enhances the imaging ability of a cell-impermeable peptide probe that targets microtubules, enabling the dynamic tracking of mitosis in live cells.

scholarly journals A dual-labeling probe to track functional mitochondria–lysosome interactions in live cells

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Qixin Chen ◽  
Hongbao Fang ◽  
Xintian Shao ◽  
Zhiqi Tian ◽  
Shanshan Geng ◽  
...  
Keyword(s):  
Fluorescence Intensity ◽  
Fluorescent Probes ◽  
Living Cells ◽  
Molecular Probe ◽  
Live Cells ◽  
Blue Fluorescence ◽  
Red Fluorescence ◽  
Dynamic Tracking ◽  
A Cell

AbstractMitochondria–lysosome interactions are essential for maintaining intracellular homeostasis. Although various fluorescent probes have been developed to visualize such interactions, they remain unable to label mitochondria and lysosomes simultaneously and dynamically track their interaction. Here, we introduce a cell-permeable, biocompatible, viscosity-responsive, small organic molecular probe, Coupa, to monitor the interaction of mitochondria and lysosomes in living cells. Through a functional fluorescence conversion, Coupa can simultaneously label mitochondria with blue fluorescence and lysosomes with red fluorescence, and the correlation between the red–blue fluorescence intensity indicates the progress of mitochondria–lysosome interplay during mitophagy. Moreover, because its fluorescence is sensitive to viscosity, Coupa allowed us to precisely localize sites of mitochondria–lysosome contact and reveal increases in local viscosity on mitochondria associated with mitochondria–lysosome contact. Thus, our probe represents an attractive tool for the localization and dynamic tracking of functional mitochondria–lysosome interactions in living cells.

Graphene Oxide-Peptide Conjugate as an Intracellular Protease Sensor for Caspase-3 Activation Imaging in Live Cells

2011 ◽  
Vol 123 (31) ◽  
pp. 7203-7207 ◽  
Author(s):  
Haibo Wang ◽  
Qing Zhang ◽  
Xia Chu ◽  
Tingting Chen ◽  
Jia Ge ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Caspase 3 ◽  
Live Cells

scholarly journals Nanoscale Chromatin Imaging and Analysis (nano-ChIA) platform bridges 4-D chromatin organization with molecular function

2020 ◽  
Author(s):  
Yue Li ◽  
Adam Eshein ◽  
Ranya K.A. Virk ◽  
Aya Eid ◽  
Wenli Wu ◽  
...  
Keyword(s):  
Chromatin Structure ◽  
Electron Tomography ◽  
Population Level ◽  
Average Diameter ◽  
Chromatin Organization ◽  
Live Cells ◽  
Molecular Function ◽  
Label Free ◽  
A Cell ◽  
Chromatin Packing

AbstractIn eukaryotic cells, chromatin structure is linked to transcription processes through the regulation of genome organization. Extending across multiple length-scales - from the nucleosome to higher-order three-dimensional structures - chromatin is a dynamic system which evolves throughout the lifetime of a cell. However, no individual technique can fully elucidate the behavior of chromatin organization and its relation to molecular function at all length- and timescales at both a single-cell and a cell population level. Herein, we present a multi-technique nanoscale Chromatin Imaging and Analysis (nano-ChIA) platform that bridges electron tomography and optical superresolution imaging of chromatin conformation and transcriptional processes, with resolution down to the level of individual nucleosomes, with high-throughput, label-free analysis of chromatin packing and its dynamics in live cells. Utilizing nano-ChIA, we observed that chromatin is localized into spatially separable packing domains, with an average diameter of around 200 nm, sub-Mb genomic size, and an internal fractal structure. The chromatin packing behavior of these domains is directly influenced by active gene transcription. Furthermore, we demonstrated that the chromatin packing domain structure is correlated among progenitor cells and all their progeny, indicating that the organization of chromatin into fractal packing domains is heritable across cell division. Further studies employing the nano-ChIA platform have the potential to provide a more coherent picture of chromatin structure and its relation to molecular function.

Distinct photophysical behaviour and transport of cell-impermeable [Ru(bpy)2dppz]2+ in live cells using cucurbit[7]uril as a delivery system

2018 ◽  
Vol 47 (11) ◽  
pp. 3857-3863 ◽  
Author(s):  
Meenakshi N. Shinde ◽  
Soniya S. Rao ◽  
Shridhar P. Gejji ◽  
Anupa A. Kumbhar
Keyword(s):  
Cell Membrane ◽  
Delivery System ◽  
Live Cells ◽  
System P ◽  
Molecular Container ◽  
A Cell

We have successfully demonstrated the delivery of a cell-impermeable [Ru(bpy)2dppz]2+ complex across the cell membrane in live cells using a cucurbit[7]uril molecular container.

scholarly journals Semiquantification of ATP in Live Cells Using Nonspecific Desorption of DNA from Graphene Oxide as the Internal Reference

2012 ◽  
Vol 84 (20) ◽  
pp. 8622-8627 ◽  
Author(s):  
Xiaohong Tan ◽  
Tao Chen ◽  
Xiangling Xiong ◽  
Ye Mao ◽  
Guizhi Zhu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Live Cells ◽  
Internal Reference

scholarly journals Graphene Oxide and Pluronic Copolymer Aggregates–Possible Route to Modulate the Adsorption of Fluorophores and Imaging of Live Cells

2015 ◽  
Vol 119 (44) ◽  
pp. 25023-25035 ◽  
Author(s):  
Niloy Kundu ◽  
Arpita Roy ◽  
Debasis Banik ◽  
Jagannath Kuchlyan ◽  
Nilmoni Sarkar
Keyword(s):  
Graphene Oxide ◽  
Live Cells

scholarly journals Role of calcium-phosphate deposition in vascular smooth muscle cell calcification

2011 ◽  
Vol 300 (1) ◽  
pp. C210-C220 ◽  
Author(s):  
Ricardo Villa-Bellosta ◽  
Angel Millan ◽  
Víctor Sorribas
Keyword(s):  
Smooth Muscle ◽  
Calcium Phosphate ◽  
Vascular Smooth Muscle ◽  
Bone Markers ◽  
Active Role ◽  
Live Cells ◽  
Transmission Electron ◽  
A Cell ◽  
Independent Process

In this work we are studying whether calcium phosphate deposition (CPD) during vascular calcification is a passive or a cell-mediated mechanism. Passive CPD was studied in fixed vascular smooth muscle cells (VSMC), which calcify faster than live cells in the presence of 1.8 mM Ca2+ and 2 mM Pi. CPD seems to be a cell-independent process that depends on the concentration of calcium, phosphate, and hydroxyl ions, but not on Ca × Pi concentration products, given that deposition is obtained with 2 × 2 and 4 × 1 Ca × Pi mM2 but not with 2 × 1 or 1 × 4 Ca × Pi mM2. Incubation with 4 mM Pi without CPD (i.e., plus 1 mM Ca) does not induce osteogene expression. Increased expression of bone markers such as Bmp2 and Cbfa1 is only observed concomitantly with CPD. Hydroxyapatite is the only crystalline phase in both lysed and live cells. Lysed cell deposits are highly crystalline, whereas live cell deposits still contain large amounts of amorphous calcium. High-resolution transmission electron microscopy revealed a nanostructure of rounded crystallites of 5–10 nm oriented at random in lysed cells, which is compatible with spontaneous precipitation. The nanostructure in live cells consisted of long fiber crystals, 10-nm thick, embedded in an amorphous matrix. This structure indicates an active role of cells in the process of hydroxyapatite crystallization. In conclusion, our data suggest that CPD is a passive phenomenon, which triggers the osteogenic changes that are involved in the formation of a well organized, calcified crystalline structure.

scholarly journals Epithelial cell extrusion requires the sphingosine-1-phosphate receptor 2 pathway

2011 ◽  
Vol 193 (4) ◽  
pp. 667-676 ◽  
Author(s):  
Yapeng Gu ◽  
Tetyana Forostyan ◽  
Roger Sabbadini ◽  
Jody Rosenblatt
Keyword(s):  
Stem Cells ◽  
Epithelial Cell ◽  
Kinase Activity ◽  
Apoptotic Cell ◽  
Sphingosine Kinase ◽  
Live Cells ◽  
Sphingosine 1 Phosphate ◽  
A Cell ◽  
Dying Cells ◽  
Cell Extrusion

To maintain an intact barrier, epithelia eliminate dying cells by extrusion. During extrusion, a cell destined for apoptosis signals its neighboring cells to form and contract a ring of actin and myosin, which squeezes the dying cell out of the epithelium. Here, we demonstrate that the signal produced by dying cells to initiate this process is sphingosine-1-phosphate (S1P). Decreasing S1P synthesis by inhibiting sphingosine kinase activity or by blocking extracellular S1P access to its receptor prevented apoptotic cell extrusion. Extracellular S1P activates extrusion by binding the S1P2 receptor in the cells neighboring a dying cell, as S1P2 knockdown in these cells or its loss in a zebrafish mutant disrupted cell extrusion. Because live cells can also be extruded, we predict that this S1P pathway may also be important for driving delamination of stem cells during differentiation or invasion of cancer cells.

scholarly journals A mammalian homolog of the zebrafish transmembrane protein 2 (TMEM2) is the long-sought-after cell-surface hyaluronidase

2017 ◽  
Vol 292 (18) ◽  
pp. 7304-7313 ◽  
Author(s):  
Hayato Yamamoto ◽  
Yuki Tobisawa ◽  
Toshihiro Inubushi ◽  
Fumitoshi Irie ◽  
Chikara Ohyama ◽  
...  
Keyword(s):  
Cell Surface ◽  
Dermatan Sulfate ◽  
Transmembrane Protein ◽  
Live Cells ◽  
Dependent Manner ◽  
Cellular Functions ◽  
Ph Optimum ◽  
Hyaluronidase Activity ◽  
A Cell ◽  
Intermediate Size

Hyaluronan (HA) is an extremely large polysaccharide (glycosaminoglycan) involved in many cellular functions. HA catabolism is thought to involve the initial cleavage of extracellular high-molecular-weight (HMW) HA into intermediate-size HA by an extracellular or cell-surface hyaluronidase, internalization of intermediate-size HA, and complete degradation into monosaccharides in lysosomes. Despite considerable research, the identity of the hyaluronidase responsible for the initial HA cleavage in the extracellular space remains elusive. HYAL1 and HYAL2 have properties more consistent with lysosomal hyaluronidases, whereas CEMIP/KIAA1199, a recently identified HA-binding molecule that has HA-degrading activity, requires the participation of the clathrin-coated pit pathway of live cells for HA degradation. Here we show that transmembrane protein 2 (TMEM2), a mammalian homolog of a protein playing a role in zebrafish endocardial cushion development, is a cell-surface hyaluronidase. Live immunostaining and surface biotinylation assays confirmed that mouse TMEM2 is expressed on the cell surface in a type II transmembrane topology. TMEM2 degraded HMW-HA into ∼5-kDa fragments but did not cleave chondroitin sulfate or dermatan sulfate, indicating its specificity to HA. The hyaluronidase activity of TMEM2 was Ca2+-dependent; the enzyme's pH optimum is around 6–7, and unlike CEMIP/KIAA1199, TMEM2 does not require the participation of live cells for its hyaluronidase activity. Moreover, TMEM2-expressing cells could eliminate HA immobilized on a glass surface in a contact-dependent manner. Together, these data suggest that TMEM2 is the long-sought-after hyaluronidase that cleaves extracellular HMW-HA into intermediate-size fragments before internalization and degradation in the lysosome.

scholarly journals Simultaneous intracellular redox potential and pH measurements in live cells using SERS nanosensors

The Analyst ◽  
2015 ◽  
Vol 140 (7) ◽  
pp. 2330-2335 ◽  
Author(s):  
L. E. Jamieson ◽  
A. Jaworska ◽  
J. Jiang ◽  
M. Baranska ◽  
D. J. Harrison ◽  
...  
Keyword(s):  
Redox Potential ◽  
Single Cell ◽  
Live Cells ◽  
Ph Measurements ◽  
Cell Basis ◽  
Redox Responsive ◽  
Cell Measurement ◽  
A Cell ◽  
Intracellular Redox

In this paper we have presented the first example of multiplexing pH and redox responsive SERS nanosensors for intracellular live single cell measurement on a cell by cell basis.

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