scholarly journals Rational Design of a Bifunctional AND-Gate Ligand to Modulate Cell-Cell Interactions

2019 ◽  
Author(s):  
Jungmin Lee ◽  
Andyna Vernet ◽  
Katherine Redfield ◽  
Shulin Lu ◽  
Ionita C. Ghiran ◽  
...  
Keyword(s):  
Rational Design ◽  
Structural Model ◽  
Molecular Geometry ◽  
Glycophorin A ◽  
Cell Type ◽  
V Region ◽  
Meso Scale ◽  
Signaling Activity

ABSTRACTProtein “AND-gate” systems, in which a ligand acts only on cells with two different receptors, direct signaling activity to a particular cell type and avoid action on other cells. In a bifunctional AND-Gate protein, the molecular geometry of the protein domains is crucial. Here we constructed a tissue-targeted erythropoietin (EPO) that stimulates red blood cell (RBC) production without triggering thrombosis. EPO was directed to RBC precursors and mature RBCs by fusion to an anti-glycophorin A antibody V region. Many such constructs activated EPO receptorsin vitroand stimulated RBC and not platelet production in mice but nonetheless enhanced thrombosis in mice and caused adhesion between RBCs and EPO receptor-bearing cells. Based on a protein-structural model of the RBC surface, we rationally designed an anti-glycophorin/EPO fusion that does not induce cell adhesionin vitroor enhance thrombosisin vivo. Thus, meso-scale geometry can inform design of synthetic-biological systems.

Ultrastructural Correlations between Clonal Human Tumor Colonies and in Vivo Neoplasms

1982 ◽  
Vol 40 ◽  
pp. 210-211
Author(s):  
M.J. Murphy ◽  
R.R. Price ◽  
J.C. Sloman
Keyword(s):  
Cultured Cells ◽  
Human Tumor ◽  
Cell Type ◽  
Tumor Mass ◽  
Initial Cell ◽  
Cloning Assay ◽  
Human Tumor Cloning ◽  
The Relationship

The in vitro human tumor cloning assay originally described by Salmon and Hamburger has been applied recently to the investigation of differential anti-tumor drug sensitivities over a broad range of human neoplasms. A major problem in the acceptance of this technique has been the question of the relationship between the cultured cells and the original patient tumor, i.e., whether the colonies that develop derive from the neoplasm or from some other cell type within the initial cell population. A study of the ultrastructural morphology of the cultured cells vs. patient tumor has therefore been undertaken to resolve this question. Direct correlation was assured by division of a common tumor mass at surgical resection, one biopsy being fixed for TEM studies, the second being rapidly transported to the laboratory for culture.

The Hierarchic Order of Intermediate Filament Structure and Assembly

1985 ◽  
Vol 43 ◽  
pp. 722-725
Author(s):  
U. Aebi ◽  
E.C. Glavaris ◽  
R. Eichner
Keyword(s):  
Tissue Specificity ◽  
Structural Model ◽  
Eukaryotic Cells ◽  
Cdna Sequencing ◽  
Filament Structure ◽  
Keratin Filaments ◽  
Isoelectric Points ◽  
Immunological Crossreactivity

Five different classes of intermediate-sized filaments (IFs) have been identified in differentiated eukaryotic cells: vimentin in mesenchymal cells, desmin in muscle cells, neurofilaments in nerve cells, glial filaments in glial cells and keratin filaments in epithelial cells. Despite their tissue specificity, all IFs share several common attributes, including immunological crossreactivity, similar morphology (e.g. about 10 nm diameter - hence ‘10-nm filaments’) and the ability to reassemble in vitro from denatured subunits into filaments virtually indistinguishable from those observed in vivo. Further more, despite their proteinchemical heterogeneity (their MWs range from 40 kDa to 200 kDa and their isoelectric points from about 5 to 8), protein and cDNA sequencing of several IF polypeptides (for refs, see 1,2) have provided the framework for a common structural model of all IF subunits.

scholarly journals 99mTc Labelling Strategies for the Development of Potential Nitroimidazolic Hypoxia Imaging Agents

Inorganics ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 128 ◽  
Author(s):  
Giglio ◽  
Rey
Keyword(s):  
Rational Design ◽  
Biological Properties ◽  
Fine Tuning ◽  
Oxidation States ◽  
Hypoxia Imaging ◽  
Biological Target ◽  
99Mtc Radiopharmaceuticals ◽  
99Mtc Labelling

Technetium-99m has a rich coordination chemistry that offers many possibilities in terms of oxidation states and donor atom sets. Modifications in the structure of the technetium complexes could be very useful for fine tuning the physicochemical and biological properties of potential 99mTc radiopharmaceuticals. However, systematic study of the influence of the labelling strategy on the “in vitro” and “in vivo” behaviour is necessary for a rational design of radiopharmaceuticals. Herein we present a review of the influence of the Tc complexes’ molecular structure on the biodistribution and the interaction with the biological target of potential nitroimidazolic hypoxia imaging radiopharmaceuticals presented in the literature from 2010 to the present. Comparison with the gold standard [18F]Fluoromisonidazole (FMISO) is also presented.

scholarly journals High-throughput screening and rational design of biofunctionalized surfaces with optimized biocompatibility and antimicrobial activity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhou Fang ◽  
Junjian Chen ◽  
Ye Zhu ◽  
Guansong Hu ◽  
Haoqian Xin ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
High Throughput ◽  
High Throughput Screening ◽  
Rational Design ◽  
Click Reaction ◽  
Reaction Times ◽  
Great Promise ◽  
Biomaterial Surfaces

AbstractPeptides are widely used for surface modification to develop improved implants, such as cell adhesion RGD peptide and antimicrobial peptide (AMP). However, it is a daunting challenge to identify an optimized condition with the two peptides showing their intended activities and the parameters for reaching such a condition. Herein, we develop a high-throughput strategy, preparing titanium (Ti) surfaces with a gradient in peptide density by click reaction as a platform, to screen the positions with desired functions. Such positions are corresponding to optimized molecular parameters (peptide densities/ratios) and associated preparation parameters (reaction times/reactant concentrations). These parameters are then extracted to prepare nongradient mono- and dual-peptide functionalized Ti surfaces with desired biocompatibility or/and antimicrobial activity in vitro and in vivo. We also demonstrate this strategy could be extended to other materials. Here, we show that the high-throughput versatile strategy holds great promise for rational design and preparation of functional biomaterial surfaces.

scholarly journals Experimental and theoretical explorations of nanocarriers’ multistep delivery performance for rational design and anticancer prediction

2021 ◽  
Vol 7 (6) ◽  
pp. eaba2458
Author(s):  
Weier Bao ◽  
Falin Tian ◽  
Chengliang Lyu ◽  
Bin Liu ◽  
Bin Li ◽  
...  
Keyword(s):  
Physical Properties ◽  
Rational Design ◽  
Theoretical Models ◽  
Cell Uptake ◽  
Anticancer Efficacy ◽  
Delivery Performance ◽  
Simulation Based ◽  
Multistep Process

The poor understanding of the complex multistep process taken by nanocarriers during the delivery process limits the delivery efficiencies and further hinders the translation of these systems into medicine. Here, we describe a series of six self-assembled nanocarrier types with systematically altered physical properties including size, shape, and rigidity, as well as both in vitro and in vivo analyses of their performance in blood circulation, tumor penetration, cancer cell uptake, and anticancer efficacy. We also developed both data and simulation-based models for understanding the influence of physical properties, both individually and considered together, on each delivery step and overall delivery process. Thus, beyond finding that nanocarriers that are simultaneously endowed with tubular shape, short length, and low rigidity outperformed the other types, we now have a suit of theoretical models that can predict how nanocarrier properties will individually and collectively perform in the multistep delivery of anticancer therapies.

scholarly journals Streptococcal Adhesion and Colonization

1997 ◽  
Vol 8 (2) ◽  
pp. 175-200 ◽  
Author(s):  
H.F. Jenkinson ◽  
RJ Lamont
Keyword(s):  
Immune Modulation ◽  
Rational Design ◽  
Repeated Sequence ◽  
Host Cells ◽  
Mammalian Host ◽  
Related Factors ◽  
Bacterial Populations ◽  
Acellular Vaccines

Streptococci express arrays of adhesins on their cell surfaces that facilitate adherence to substrates present in their natural environment within the mammalian host. A consequence of such promiscuous binding ability is that streptococcal cells may adhere simultaneously to a spectrum of substrates, including salivary glycoproteins, extracellular matrix and serum components, host cells, and other microbial cells. The multiplicity of streptococcal adherence interactions accounts, at least in part, for their success in colonizing the oral and epithelial surfaces of humans. Adhesion facilitates colonization and may be a precursor to tissue invasion and immune modulation, events that presage the development of disease. Many of the streptococcal adhesins and virulence-related factors are cell-wall-associated proteins containing repeated sequence blocks of amino acids. Linear sequences, both within the blocks and within non-repetitive regions of the proteins, have been implicated in substrate binding. Sequences and functions of these proteins among the streptococci have become assorted through gene duplication and horizontal transfer between bacterial populations. Several adhesins identified and characterized through in vitro binding assays have been analyzed for in vivo expression and function by means of animal models used for colonization and virulence. Information on the molecular structure of adhesins as related to their in vivo function will allow for the rational design of novel acellular vaccines, recombinant antibodies, and adhesion agonists for the future control or prevention of streptococcal colonization and streptococcal diseases.

scholarly journals TRPM7 and CaV3.2 channels mediate Ca2+ influx required for egg activation at fertilization

2018 ◽  
Vol 115 (44) ◽  
pp. E10370-E10378 ◽  
Author(s):  
Miranda L. Bernhardt ◽  
Paula Stein ◽  
Ingrid Carvacho ◽  
Christopher Krapp ◽  
Goli Ardestani ◽  
...  
Keyword(s):  
Rational Design ◽  
Culture Media ◽  
Mammalian Development ◽  
Developmental Potential ◽  
Store Depletion ◽  
Offspring Growth ◽  
Mechanistic Basis ◽  
Genetic Mouse Models

The success of mammalian development following fertilization depends on a series of transient increases in egg cytoplasmic Ca2+, referred to as Ca2+ oscillations. Maintenance of these oscillations requires Ca2+ influx across the plasma membrane, which is mediated in part by T-type, CaV3.2 channels. Here we show using genetic mouse models that TRPM7 channels are required to support this Ca2+ influx. Eggs lacking both TRPM7 and CaV3.2 stop oscillating prematurely, indicating that together they are responsible for the majority of Ca2+ influx immediately following fertilization. Fertilized eggs lacking both channels also frequently display delayed resumption of Ca2+ oscillations, which appears to require sperm–egg fusion. TRPM7 and CaV3.2 channels almost completely account for Ca2+ influx observed following store depletion, a process previously attributed to canonical store-operated Ca2+ entry mediated by STIM/ORAI interactions. TRPM7 serves as a membrane sensor of extracellular Mg2+ and Ca2+ concentrations and mediates the effects of these ions on Ca2+ oscillation frequency. When bred to wild-type males, female mice carrying eggs lacking TRPM7 and CaV3.2 are subfertile, and their offspring have increased variance in postnatal weight. These in vivo findings confirm previous observations linking in vitro experimental alterations in Ca2+ oscillatory patterns with developmental potential and offspring growth. The identification of TRPM7 and CaV3.2 as key mediators of Ca2+ influx following fertilization provides a mechanistic basis for the rational design of culture media that optimize developmental potential in research animals, domestic animals, and humans.

scholarly journals xMD-miRNA-seq to generate near in vivo miRNA expression estimates in colon epithelial cells

2018 ◽  
Author(s):  
Avi Z. Rosenberg ◽  
Carrie Wright ◽  
Karen Fox-Talbot ◽  
Anandita Rajpurohit ◽  
Courtney Williams ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Small Rna ◽  
Mirna Expression ◽  
Low Cost ◽  
Expression Patterns ◽  
Small Rna Sequencing ◽  
Rna Seq ◽  
Cell Type

AbstractAccurate, RNA-seq based, microRNA (miRNA) expression estimates from primary cells have recently been described. However, this in vitro data is mainly obtained from cell culture, which is known to alter cell maturity/differentiation status, significantly changing miRNA levels. What is needed is a robust method to obtain in vivo miRNA expression values directly from cells. We introduce expression microdissection miRNA small RNA sequencing (xMD-miRNA-seq), a method to isolate cells directly from formalin fixed paraffin-embedded (FFPE) tissues. xMD-miRNA-seq is a low-cost, high-throughput, immunohistochemistry-based method to capture any cell type of interest. As a proof-of-concept, we isolated colon epithelial cells from two specimens and performed low-input small RNA-seq. We generated up to 600,000 miRNA reads from the samples. Isolated epithelial cells, had abundant epithelial-enriched miRNA expression (miR-192; miR-194; miR-200b; miR-200c; miR-215; miR-375) and overall similar miRNA expression patterns to other epithelial cell populations (colonic enteroids and flow-isolated colon epithelium). xMD-derived epithelial cells were generally not contaminated by other adjacent cells of the colon as noted by t-SNE analysis. xMD-miRNA-seq allows for simple, economical, and efficient identification of cell-specific miRNA expression estimates. Further development will enhance rapid identification of cell-specific miRNA expression estimates in health and disease for nearly any cell type using archival FFPE material.

scholarly journals Btbd11 is an inhibitory interneuron specific synaptic scaffolding protein that supports excitatory synapse structure and function

2021 ◽  
Author(s):  
Alexei M. Bygrave ◽  
Ayesha Sengupta ◽  
Ella P. Jackert ◽  
Mehroz Ahmed ◽  
Beloved Adenuga ◽  
...  
Keyword(s):  
Inhibitory Interneuron ◽  
Nmda Receptor Antagonist ◽  
Specific Protein ◽  
Network Activity ◽  
Scaffolding Protein ◽  
Inhibitory Interneurons ◽  
Cell Type ◽  
Cell Type Specific

Synapses in the brain exhibit cell–type–specific differences in basal synaptic transmission and plasticity. Here, we evaluated cell–type–specific differences in the composition of glutamatergic synapses, identifying Btbd11, as an inhibitory interneuron–specific synapse–enriched protein. Btbd11 is highly conserved across species and binds to core postsynaptic proteins including Psd–95. Intriguingly, we show that Btbd11 can undergo liquid–liquid phase separation when expressed with Psd–95, supporting the idea that the glutamatergic post synaptic density in synapses in inhibitory and excitatory neurons exist in a phase separated state. Knockout of Btbd11 from inhibitory interneurons decreased glutamatergic signaling onto parvalbumin–positive interneurons. Further, both in vitro and in vivo, we find that Btbd11 knockout disrupts network activity. At the behavioral level, Btbd11 knockout from interneurons sensitizes mice to pharmacologically induced hyperactivity following NMDA receptor antagonist challenge. Our findings identify a cell–type–specific protein that supports glutamatergic synapse function in inhibitory interneurons–with implication for circuit function and animal behavior.

scholarly journals Rational design of protein-specific folding modifiers

2020 ◽  
Author(s):  
Anirban Das ◽  
Anju Yadav ◽  
Mona Gupta ◽  
R Purushotham ◽  
Vishram L. Terse ◽  
...  
Keyword(s):  
Single Molecule ◽  
Rational Design ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Force Measurements ◽  
Folding Nucleus ◽  
Dynamics Simulations ◽  
General Method

AbstractProtein folding can go wrong in vivo and in vitro, with significant consequences for the living cell and the pharmaceutical industry, respectively. Here we propose a general design principle for constructing small peptide-based protein-specific folding modifiers. We construct a ‘xenonucleus’, which is a pre-folded peptide that resembles the folding nucleus of a protein, and demonstrate its activity on the folding of ubiquitin. Using stopped-flow kinetics, NMR spectroscopy, Förster Resonance Energy transfer, single-molecule force measurements, and molecular dynamics simulations, we show that the ubiquitin xenonucleus can act as an effective decoy for the native folding nucleus. It can make the refolding faster by 33 ± 5% at 3 M GdnHCl. In principle, our approach provides a general method for constructing specific, genetically encodable, folding modifiers for any protein which has a well-defined contiguous folding nucleus.

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