Effects of Elevated Pressure and Narcotic Gases on Calcium Dependent Cell Functions

1994 ◽  
Author(s):  
R. B. Philp ◽  
D. J. McIver
Keyword(s):  
Elevated Pressure ◽  
Calcium Dependent ◽  
Cell Functions ◽  
Dependent Cell

scholarly journals A novel phospho-modulatory mechanism contributes to the calcium-dependent regulation of T-type Ca2+ channels

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jean Chemin ◽  
Tamara Timic Stamenic ◽  
Magalie Cazade ◽  
Jodie Llinares ◽  
Iulia Blesneac ◽  
...  
Keyword(s):  
Calcium Dependent ◽  
Cell Functions ◽  
Medial Nucleus ◽  
Steady State Inactivation ◽  
Intracellular Ca ◽  
Phosphorylation Mechanism ◽  
Multiple Cell ◽  
Atp Analogs ◽  
Ca2 Channels ◽  
Endocytic Pathways

Abstract Cav3 / T-type Ca2+ channels are dynamically regulated by intracellular Ca2+ ions, which inhibit Cav3 availability. Here, we demonstrate that this inhibition becomes irreversible in the presence of non-hydrolysable ATP analogs, resulting in a strong hyperpolarizing shift in the steady-state inactivation of the residual Cav3 current. Importantly, the effect of these ATP analogs was prevented in the presence of intracellular BAPTA. Additional findings obtained using intracellular dialysis of inorganic phosphate and alkaline phosphatase or NaN3 treatment further support the involvement of a phosphorylation mechanism. Contrasting with Cav1 and Cav2 Ca2+ channels, the Ca2+-dependent modulation of Cav3 channels appears to be independent of calmodulin, calcineurin and endocytic pathways. Similar findings were obtained for the native T-type Ca2+ current recorded in rat thalamic neurons of the central medial nucleus. Overall, our data reveal a new Ca2+ sensitive phosphorylation-dependent mechanism regulating Cav3 channels, with potentially important physiological implications for the multiple cell functions controlled by T-type Ca2+ channels.

scholarly journals Electrophysiological engineering of heart-derived cells with calcium-dependent potassium channels improves cell therapy efficacy for cardioprotection

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Patrick Vigneault ◽  
Sandrine Parent ◽  
Pushpinder Kanda ◽  
Connor Michie ◽  
Darryl R. Davis ◽  
...  
Keyword(s):  
Cell Therapy ◽  
Therapeutic Potential ◽  
Resting Potential ◽  
Intramyocardial Injection ◽  
Membrane Hyperpolarization ◽  
Calcium Dependent ◽  
Cell Functions ◽  
Kca Channels ◽  
Therapy Effectiveness ◽  
Intracellular Ca

AbstractWe have shown that calcium-activated potassium (KCa)-channels regulate fundamental progenitor-cell functions, including proliferation, but their contribution to cell-therapy effectiveness is unknown. Here, we test the participation of KCa-channels in human heart explant-derived cell (EDC) physiology and therapeutic potential. TRAM34-sensitive KCa3.1-channels, encoded by the KCNN4 gene, are exclusively expressed in therapeutically bioactive EDC subfractions and maintain a strongly polarized resting potential; whereas therapeutically inert EDCs lack KCa3.1 channels and exhibit depolarized resting potentials. Somatic gene transfer of KCNN4 results in membrane hyperpolarization and increases intracellular [Ca2+], which boosts cell-proliferation and the production of pro-healing cytokines/nanoparticles. Intramyocardial injection of EDCs after KCNN4-gene overexpression markedly increases the salutary effects of EDCs on cardiac function, viable myocardium and peri-infarct neovascularization in a well-established murine model of ischemic cardiomyopathy. Thus, electrophysiological engineering provides a potentially valuable strategy to improve the therapeutic value of progenitor cells for cardioprotection and possibly other indications.

Structural features and functional domains of amassin-1, a cell-binding olfactomedin protein

2007 ◽  
Vol 85 (5) ◽  
pp. 552-562 ◽  
Author(s):  
Brian J. Hillier ◽  
Victor D. Vacquier
Keyword(s):  
Disulfide Bonds ◽  
Biological Activities ◽  
Structural Features ◽  
Body Cavity ◽  
Binding Activity ◽  
Coiled Coils ◽  
Cell Binding ◽  
Calcium Dependent ◽  
Dependent Cell ◽  
A Cell

Amassin-1 mediates a rapid cell adhesion that tightly adheres sea urchin coelomocytes (body cavity immunocytes) together. Three major structural regions exist in amassin-1: a short β region, 3 coiled coils, and an olfactomedin domain. Amassin-1 contains 8 disulfide-bonded cysteines that, upon reduction, render it inactive. Truncated forms of recombinant amassin-1 were expressed and purified from Pichia pastoris and their disulfide bonding and biological activities investigated. Expressed alone, the olfactomedin domain contained 2 intramolecular disulfide bonds, existed in a monomeric state, and inhibited amassin-1-mediated clotting of coelomocytes by a calcium-dependent cell-binding activity. The N-terminal β region, containing 3 cysteines, was not required for clotting activity. The coiled coils may dimerize amassin-1 in a parallel orientation through a homodimerizing disulfide bond. Neither amassin-1 fragments that were disulfide-linked as dimers or that were engineered to exist as dimers induced coelomocytes clotting. Clotting required higher multimeric states of amassin-1, possibly tetramers, which occurred through the N-terminal β region and (or) the first segment of coiled coils.

scholarly journals KCNJ11 knockout morula re-engineered by stem cell diploid aggregation

2008 ◽  
Vol 364 (1514) ◽  
pp. 269-276 ◽  
Author(s):  
Timothy J Nelson ◽  
Almudena Martinez-Fernandez ◽  
Andre Terzic
Keyword(s):  
Metabolic Flux ◽  
Ex Vivo ◽  
Gene Knockout ◽  
Embryonic Stem ◽  
Adaptive Behaviour ◽  
Wild Type ◽  
New Paradigm ◽  
Cell Functions ◽  
Dependent Cell ◽  
Channel Dependent

KCNJ11 -encoded Kir6.2 assembles with ATP-binding cassette sulphonylurea receptors to generate ATP-sensitive K + (K ATP ) channel complexes. Expressed in tissues with dynamic metabolic flux, these evolutionarily conserved yet structurally and functionally unique heteromultimers serve as high-fidelity rheostats that adjust membrane potential-dependent cell functions to match energetic demand. Genetic defects in channel subunits disrupt the cellular homeostatic response to environmental stress, compromising organ tolerance in the adult. As maladaptation characterizes malignant K ATP channelopathies, establishment of platforms to examine progression of K ATP channel-dependent adaptive behaviour is warranted. Chimeras provide a powerful tool to assay the contribution of genetic variance to stress intolerance during prenatal or post-natal development. Here, KCNJ11 K ATP channel gene knockout↔wild-type chimeras were engineered through diploid aggregation. Integration of wild-type embryonic stem cells into zona pellucida-denuded morula derived from knockout embryos achieved varying degrees of incorporation of stress-tolerant tissue within the K ATP channel-deficient background. Despite the stress-vulnerable phenotype of the knockout, ex vivo derived mosaic blastocysts tolerated intrauterine transfer and implantation, followed by full-term embryonic development in pseudopregnant surrogates to produce live chimeric offspring. The development of adult chimerism from the knockout↔wild-type mosaic embryo offers thereby a new paradigm to probe the ecogenetic control of the K ATP channel-dependent stress response.

scholarly journals Desmosomal glycoproteins 2 and 3 (desmocollins) show N-terminal similarity to calcium-dependent cell-cell adhesion molecules

1990 ◽  
Vol 97 (2) ◽  
pp. 239-246
Author(s):  
J.L. Holton ◽  
T.P. Kenny ◽  
P.K. Legan ◽  
J.E. Collins ◽  
J.N. Keen ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Cell Adhesion ◽  
Intercellular Space ◽  
Solid Phase ◽  
Rabbit Antiserum ◽  
High Titre ◽  
Polyclonal Antiserum ◽  
Keyhole Limpet Haemocyanin ◽  
Calcium Dependent ◽  
Dependent Cell

The N-terminal sequence of a mixture of desmosomal glycoproteins 2 and 3 (dg2/3, desmocollins) from bovine nasal epidermis, prepared by electro-elution from polyacrylamide gels, was determined by solid-phase Edman degradation. A sequence of 23 amino acids was obtained. This showed 43% identity with that of the N terminus of the calcium-dependent cell adhesion molecule, N-cadherin. A lesser degree of identity with other members of the cadherin-uvomorulin-L-CAM family was also found. In order to confirm that the sequence was derived from the dg2/3 molecules a rabbit antiserum was raised against a synthetic peptide corresponding to the sequence, conjugated to keyhole limpet haemocyanin (KLH). The antiserum obtained showed high (titre) activity against both the peptide and KLH in ELISA. Each activity could be specifically adsorbed with the appropriate ligand. The antiserum reacted specifically with both dg2 and dg3 of bovine nasal epidermis on immunoblots, this binding was blocked by the N-terminal peptide but was unaffected by KLH. The identity of dg2 and -3 in these preparations was confirmed by immunoblotting with two monoclonal antibodies and one polyclonal antiserum raised against the whole molecules. The N-terminal peptide antiserum was shown to bind to the intercellular space of desmosome profiles by immunoelectron microscopy on ultra-thin frozen sections. One of the two monoclonal antibodies (07–4D) also reacted with the desmosomal intercellular space. dg2 and -3 were shown by Staphylococcus aureus V8 protease digestion to have identical one-dimensional peptide maps. Both the N-terminal antiserum and 07–4D reacted with a V8 fragment of 19,000 Mr derived from dg2 and dg3.(ABSTRACT TRUNCATED AT 250 WORDS)

Discovery of a Novel Small-Molecule Interleukin-6 Inhibitor through Virtual Screening Using Artificial Intelligence

2021 ◽  
Vol 18 ◽  
Author(s):  
Yoshiaki Sato ◽  
Ikuo Kashiwakura ◽  
Masaru Yamaguchi ◽  
Hironori Yoshino ◽  
Takeshi Tanaka ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Small Molecule ◽  
Interleukin 6 ◽  
Inflammatory Diseases ◽  
Biological Activities ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Cell Functions ◽  
Dependent Cell ◽  
Dose Dependent

Background: Interleukin-6 (IL-6) is a multifunctional cytokine involved in various cell functions and diseases. Thus far, several IL-6 inhibitors, such as, humanized monoclonal antibody have been used to block excessive IL-6 signaling causing autoimmune and inflammatory diseases. However, anti-IL-6 and anti-IL-6 receptor monoclonal antibodies have some clinical disadvantages, such as a high cost, unfavorable injection route, and tendency to mask infectious diseases. While a small-molecule IL-6 inhibitor would help mitigate these issues, none are currently available. Objective: The present study evaluated the biological activities of identified compounds on IL-6 stimulus. Methods: We virtually screened potential IL-6 binders from a compound library using INTerprotein’s Engine for New Drug Design (INTENDD®) followed by the identification of more potent IL-6 binders with artificial intelligence (AI)-guided INTENDD®. The biological activities of the identified compounds were assessed with the IL-6-dependent cell line 7TD1. Results: The compounds showed the suppression of IL-6-dependent cell growth in a dose-dependent manner. Furthermore, the identified compound inhibited expression of IL-6-induced phosphorylation of signal transducer and activator of transcription 3 in a dose-dependent manner. Conclusion: Our screening compound demonstrated an inhibitory effect on IL-6 stimulus. These findings may serve as a basis for the further development of small-molecule IL-6 inhibitors.

Sign in / Sign up

Export Citation Format

Share Document