Multimode light microscopy and fluorescence-based reagents as tools for the study of chemical and molecular dynamics of living cells and tissues

1992 ◽  
Vol 50 (1) ◽  
pp. 418-419
Author(s):  
D. L. Taylor
Keyword(s):  
Living Cells ◽  
Cellular Level ◽  
Molecular Techniques ◽  
Cellular Functions ◽  
Macromolecular Assemblies ◽  
Cell Functions ◽  
Molecular Events ◽  
Yield Information ◽  
Full Knowledge ◽  
Structural Methods

Cells function through the complex temporal and spatial interplay of ions, metabolites, macromolecules and macromolecular assemblies. Biochemical approaches allow the investigator to define the components and the solution chemical reactions that might be involved in cellular functions. Static structural methods can yield information concerning the 2- and 3-D organization of known and unknown cellular constituents. Genetic and molecular techniques are powerful approaches that can alter specific functions through the manipulation of gene products and thus identify necessary components and sequences of molecular events. However, full knowledge of the mechanism of particular cell functions will require direct measurement of the interplay of cellular constituents. Therefore, there has been a need to develop methods that can yield chemical and molecular information in time and space in living cells, while allowing the integration of information from biochemical, molecular and genetic approaches at the cellular level.

scholarly journals Phosphoinositide-derived messengers in endocrine signaling

2006 ◽  
Vol 188 (2) ◽  
pp. 135-153 ◽  
Author(s):  
T Balla
Keyword(s):  
Protein Complexes ◽  
Modern Concept ◽  
Cellular Functions ◽  
Surface Receptors ◽  
Cell Functions ◽  
Molecular Events ◽  
Membrane Compartments ◽  
Specific Receptors ◽  
Endocrine Signaling ◽  
G Protein Coupled

One of the fundamental questions in endocrinology is how circulating or locally produced hormones affect target cell functions by activating specific receptors linked to numerous signal-transduction pathways. An important subset of G protein-coupled cell-surface receptors can activate phospholipase C enzymes to hydrolyze a small but critically important class of phospholipids, the phosphoinositides. Although this signaling pathway has been extensively explored over the last 20 years, this has proven to be only the tip of the iceberg, and the multiplicity and diversity of the cellular functions controlled by phosphoinositides have surpassed any imagination. Phosphoinositides have been found to be key regulators of ion channels and transporters, and controllers of vesicular trafficking and the transport of lipids between intracellular membranes. Essentially, they organize the recruitment and regulation of signaling protein complexes in specific membrane compartments. While many of these processes have been classically studied by cell biologists, molecular endocrinology cannot ignore these recent advances, and now needs to integrate the cell biologist’s views in the modern concept of how hormones affect cell functions and how derailment of simple molecular events can lead to complex endocrine and metabolic disorders.

scholarly journals Modulating Tumor Cell Functions by Tunable Nanopatterned Ligand Presentation

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 212
Author(s):  
Katharina Amschler ◽  
Michael P. Schön
Keyword(s):  
Extracellular Matrix ◽  
Tumor Cell ◽  
Cell Fate ◽  
Epithelial Mesenchymal Transition ◽  
Model Systems ◽  
Cellular Functions ◽  
Biophysical Parameters ◽  
Ligand Density ◽  
Mesenchymal Transition ◽  
Cell Functions

Cancer comprises a large group of complex diseases which arise from the misrouted interplay of mutated cells with other cells and the extracellular matrix. The extracellular matrix is a highly dynamic structure providing biochemical and biophysical cues that regulate tumor cell behavior. While the relevance of biochemical signals has been appreciated, the complex input of biophysical properties like the variation of ligand density and distribution is a relatively new field in cancer research. Nanotechnology has become a very promising tool to mimic the physiological dimension of biophysical signals and their positive (i.e., growth-promoting) and negative (i.e., anti-tumoral or cytotoxic) effects on cellular functions. Here, we review tumor-associated cellular functions such as proliferation, epithelial-mesenchymal transition (EMT), invasion, and phenotype switch that are regulated by biophysical parameters such as ligand density or substrate elasticity. We also address the question of how such factors exert inhibitory or even toxic effects upon tumor cells. We describe three principles of nanostructured model systems based on block copolymer nanolithography, electron beam lithography, and DNA origami that have contributed to our understanding of how biophysical signals direct cancer cell fate.

Signaling and cytotoxic functions of 4-hydroxyalkenals

2010 ◽  
Vol 299 (6) ◽  
pp. E879-E886 ◽  
Author(s):  
Yael Riahi ◽  
Guy Cohen ◽  
Ofer Shamni ◽  
Shlomo Sasson
Keyword(s):  
Chemical Reactivity ◽  
Cellular Functions ◽  
Free Oxygen Radical ◽  
Lipid Molecule ◽  
Cell Functions ◽  
Peroxidation Product ◽  
Covalent Adducts ◽  
12 Lipoxygenase ◽  
Hydroperoxyeicosatetraenoic Acid ◽  
In Cells

The peroxidation of n-3 and n-6 polyunsaturated fatty acids (PUFAs) and of their hydroperoxy metabolites is a complex process. It is initiated by free oxygen radical-induced abstraction of a hydrogen atom from the lipid molecule followed by a series of nonenzymatic reactions that ultimately generate the reactive aldehyde species 4-hydroxyalkenals. The molecule 4-hydroxy- 2E-hexenal (4-HHE) is generated by peroxidation of n-3 PUFAs, such as linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid. The aldehyde product 4-hydroxy-2 E-nonenal (4-HNE) is the peroxidation product of n-6 PUFAs, such as arachidonic and linoleic acids and their 15-lipoxygenase metabolites, namely 15-hydroperoxyeicosatetraenoic acid (15-HpETE) and 13-hydroperoxyoctadecadienoic acid (13-HpODE). Another reactive peroxidation product is 4-hydroxy-2 E,6 Z-dodecadienal (4-HDDE), which is derived from 12-hydroperoxyeicosatetraenoic acid (12-HpETE), the 12-lipoxygenase metabolite of arachidonic acid. Hydroxyalkenals, notably 4-HNE, have been implicated in various pathophysiological interactions due to their chemical reactivity and the formation of covalent adducts with macromolecules. The progressive accumulation of these adducts alters normal cell functions that can lead to cell death. The lipophilicity of these aldehydes positively correlates to their chemical reactivity. Nonetheless, at low and noncytotoxic concentrations, these molecules may function as signaling molecules in cells. This has been shown mostly for 4-HNE and to some extent for 4-HHE. The capacity of 4-HDDE to generate such “mixed signals” in cells has received less attention. This review addresses the origin and cellular functions of 4-hydroxyalkernals.

scholarly journals Energetic Evolution of Cellular Transportomes

2017 ◽  
Author(s):  
Behrooz Darbani ◽  
Douglas B. Kell ◽  
Irina Borodina
Keyword(s):  
Ion Channels ◽  
Bacterial Species ◽  
Living Cells ◽  
Energetic Efficiency ◽  
Cellular Functions ◽  
Transporter Proteins ◽  
Genome Wide Analysis ◽  
Solute Carriers ◽  
Genome Wide ◽  
A Genome

ABSTRACTTransporter proteins mediate the translocation of substances across the membranes of living cells. We performed a genome-wide analysis of the compositional reshaping of cellular transporters (the transportome) across the kingdoms of bacteria, archaea, and eukarya. We show that the transportomes of eukaryotes evolved strongly towards a higher energetic efficiency, as ATP-dependent transporters diminished and secondary transporters and ion channels proliferated. This change has likely been important in the development of tissues performing energetically costly cellular functions. The transportome analysis also indicated seven bacterial species, includingNeorickettsia risticiiandNeorickettsia sennetsu, as likely origins of the mitochondrion in eukaryotes, due to the restricted presence therein of clear homologues of modern mitochondrial solute carriers.

scholarly journals Integrative ‘Omic’ Approach Towards Understanding the Nature of Human Diseases

2012 ◽  
Vol 15 (Supplement) ◽  
pp. 45-50 ◽  
Author(s):  
Borut Peterlin ◽  
A Maver
Keyword(s):  
Large Body ◽  
Experimental Information ◽  
Cellular Level ◽  
Human Diseases ◽  
Sequence Information ◽  
Proteomic Profiling ◽  
Disease Etiology ◽  
Complete Representation ◽  
Molecular Alterations ◽  
Molecular Events

ABSTRACT The combination of improving technologies for molecular interrogation of global molecular alterations in human diseases along with increases in computational capacity, have enabled unprecedented insight into disease etiology, pathogenesis and have enabled new possibilities for biomarker development. A large body of data has accumulated over recent years, with a most prominent increase in information originating from genomic, transcriptomic and proteomic profiling levels. However, the complexity of the data made discovery of highorder disease mechanisms involving various biological layers, difficult, and therefore required new approaches toward integration of such data into a complete representation of molecular events occurring on cellular level. For this reason, we developed a new mode of integration of results coming from heterogeneous origins, using rank statistics of results from each profiling level. Due to the increased use of nextgeneration sequencing technology, experimental information is becoming increasingly more associated to sequence information, for which reason we have decided to synthesize the heterogeneous results using the information of their genomic position. We therefore propose a novel positional integratomic approach toward studying ‘omic’ information in human disease.

scholarly journals The orchestrated cellular and molecular responses of the kidney to endotoxin define the sepsis timeline

2020 ◽  
Author(s):  
Danielle Janosevic ◽  
Jered Myslinski ◽  
Thomas McCarthy ◽  
Amy Zollman ◽  
Farooq Syed ◽  
...  
Keyword(s):  
Cell Communication ◽  
Tissue Level ◽  
Dynamic State ◽  
Cellular Functions ◽  
Clinical Sepsis ◽  
Human Sepsis ◽  
Molecular Events ◽  
Definition Of ◽  
Injury And Repair ◽  
Recovery Pathways

AbstractClinical sepsis is a highly dynamic state that progresses at variable rates and has life-threatening consequences. Staging patients along the sepsis timeline requires a thorough knowledge of the evolution of cellular and molecular events at the tissue level. Here, we investigated the kidney, an organ central to the pathophysiology of sepsis. Single cell RNA sequencing revealed the involvement of various cell populations in injury and repair to be temporally organized and highly orchestrated. We identified key changes in gene expression that altered cellular functions and can explain features of clinical sepsis. These changes converged towards a remarkable global cell-cell communication failure and organ shutdown at a well-defined point in the sepsis timeline. Importantly, this time point was also a transition towards the emergence of recovery pathways. This rigorous spatial and temporal definition of murine sepsis will uncover precise biomarkers and targets that can help stage and treat human sepsis.

scholarly journals SRSF3 promotes pluripotency through Nanog mRNA export and coordination of the pluripotency gene expression program

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Madara Ratnadiwakara ◽  
Stuart K Archer ◽  
Craig I Dent ◽  
Igor Ruiz De Los Mozos ◽  
Traude H Beilharz ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cellular Functions ◽  
Protein Levels ◽  
The Core ◽  
Molecular Events ◽  
Coordinate Gene Expression ◽  
Pluripotency Gene ◽  
Steady State Levels ◽  
Expression Program ◽  
Pluripotency Genes

The establishment and maintenance of pluripotency depend on precise coordination of gene expression. We establish serine-arginine-rich splicing factor 3 (SRSF3) as an essential regulator of RNAs encoding key components of the mouse pluripotency circuitry, SRSF3 ablation resulting in the loss of pluripotency and its overexpression enhancing reprogramming. Strikingly, SRSF3 binds to the core pluripotency transcription factor Nanog mRNA to facilitate its nucleo-cytoplasmic export independent of splicing. In the absence of SRSF3 binding, Nanog mRNA is sequestered in the nucleus and protein levels are severely downregulated. Moreover, SRSF3 controls the alternative splicing of the export factor Nxf1 and RNA regulators with established roles in pluripotency, and the steady-state levels of mRNAs encoding chromatin modifiers. Our investigation links molecular events to cellular functions by demonstrating how SRSF3 regulates the pluripotency genes and uncovers SRSF3-RNA interactions as a critical means to coordinate gene expression during reprogramming, stem cell self-renewal and early development.

A one-step synthesis of novel high pH-sensitive nitrogen-doped yellow fluorescent carbon dots and their detection application in living cells

2019 ◽  
Vol 11 (44) ◽  
pp. 5711-5717
Author(s):  
Lian Shen ◽  
Changjun Hou ◽  
Jaiwei Li ◽  
Xianfeng Wang ◽  
Yanan Zhao ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Disease Diagnosis ◽  
Living Cells ◽  
Ph Sensitive ◽  
Cellular Functions ◽  
High Ph ◽  
Nitrogen Doped ◽  
One Step ◽  
Fluorescent Carbon Dots ◽  
Fluorescent Carbon

Monitoring the pH in living cells is of great significance for a deeper understanding of cellular functions for effective disease diagnosis.

scholarly journals Roles of Gβγ in membrane recruitment and activation of p110γ/p101 phosphoinositide 3-kinase γ

2002 ◽  
Vol 160 (1) ◽  
pp. 89-99 ◽  
Author(s):  
Carsten Brock ◽  
Michael Schaefer ◽  
H. Peter Reusch ◽  
Cornelia Czupalla ◽  
Manuela Michalke ◽  
...  
Keyword(s):  
G Protein ◽  
Living Cells ◽  
Membrane Lipid ◽  
Cellular Functions ◽  
Direct Stimulation ◽  
Membrane Recruitment ◽  
Ph Domains ◽  
Phosphoinositide 3 Kinase ◽  
Stimulation Of

Receptor-regulated class I phosphoinositide 3-kinases (PI3K) phosphorylate the membrane lipid phosphatidylinositol (PtdIns)-4,5-P2 to PtdIns-3,4,5-P3. This, in turn, recruits and activates cytosolic effectors with PtdIns-3,4,5-P3–binding pleckstrin homology (PH) domains, thereby controlling important cellular functions such as proliferation, survival, or chemotaxis. The class IB p110γ/p101 PI3Kγ is activated by Gβγ on stimulation of G protein–coupled receptors. It is currently unknown whether in living cells Gβγ acts as a membrane anchor or an allosteric activator of PI3Kγ, and which role its noncatalytic p101 subunit plays in its activation by Gβγ. Using GFP-tagged PI3Kγ subunits expressed in HEK cells, we show that Gβγ recruits the enzyme from the cytosol to the membrane by interaction with its p101 subunit. Accordingly, p101 was found to be required for G protein–mediated activation of PI3Kγ in living cells, as assessed by use of GFP-tagged PtdIns-3,4,5-P3–binding PH domains. Furthermore, membrane-targeted p110γ displayed basal enzymatic activity, but was further stimulated by Gβγ, even in the absence of p101. Therefore, we conclude that in vivo, Gβγ activates PI3Kγ by a mechanism assigning specific roles for both PI3Kγ subunits, i.e., membrane recruitment is mediated via the noncatalytic p101 subunit, and direct stimulation of Gβγ with p110γ contributes to activation of PI3Kγ.

AMP-activated protein kinase: new regulation, new roles?

2012 ◽  
Vol 445 (1) ◽  
pp. 11-27 ◽  
Author(s):  
David Carling ◽  
Claire Thornton ◽  
Angela Woods ◽  
Matthew J. Sanders
Keyword(s):  
Protein Kinase ◽  
Living Cells ◽  
Cellular Functions ◽  
Disease States ◽  
Kinase Cascade ◽  
Amp Activated Protein Kinase ◽  
Obesity And Cancer ◽  
Hydrolysis Of ◽  
Protein Kinase Cascade

The hydrolysis of ATP drives virtually all of the energy-requiring processes in living cells. A prerequisite of living cells is that the concentration of ATP needs to be maintained at sufficiently high levels to sustain essential cellular functions. In eukaryotic cells, the AMPK (AMP-activated protein kinase) cascade is one of the systems that have evolved to ensure that energy homoeostasis is maintained. AMPK is activated in response to a fall in ATP, and recent studies have suggested that ADP plays an important role in regulating AMPK. Once activated, AMPK phosphorylates a broad range of downstream targets, resulting in the overall effect of increasing ATP-producing pathways whilst decreasing ATP-utilizing pathways. Disturbances in energy homoeostasis underlie a number of disease states in humans, e.g. Type 2 diabetes, obesity and cancer. Reflecting its key role in energy metabolism, AMPK has emerged as a potential therapeutic target. In the present review we examine the recent progress aimed at understanding the regulation of AMPK and discuss some of the latest developments that have emerged in key areas of human physiology where AMPK is thought to play an important role.

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