An Optical Approach for Studying the Cellular Mechanotransduction of Hydrostatic Pressure by Bladder Urothelial Cells

2011 ◽  
Author(s):  
Shawn Olsen ◽  
Jiro Nagatomi
Keyword(s):  
Ion Channels ◽  
Hydrostatic Pressure ◽  
Cell Volume ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Receptor Potential ◽  
Fluorescent Imaging ◽  
Urothelial Cells ◽  
Bladder Urothelium

Recent studies have suggested that the bladder urothelium is sensitive to both stretch and hydrostatic pressure during bladder filling, and is considered to play a mechanosensory role in sensing bladder fullness [1, 2]. In a previous study [3], our group demonstrated that compared to the control, rat bladder urothelial cells (UCs) exposed to hydrostatic pressure (10–15 cmH2O for 5 minutes) in vitro released significantly higher levels of ATP and that this response was attenuated by pharmacologically blocking transient receptor potential (TRP) channels, as well as epithelial sodium channels (ENACs). While blocking these ion channels inhibited the ATP response by UCs to hydrostatic pressure, it remains unclear whether these ion channels are being activated directly by hydrostatic pressure or by membrane deformation. Our current hypothesis is that a change in cell volume may occur due to the application of hydrostatic pressure and subsequent changes in cellular osmolality, which, in turn, activate the membrane-bound mechanosensitive channels. Using real-time fluorescent imaging and a custom experimental setup, the present study sought to quantify the UC cell volume changes during exposure to hydrostatic pressure and to better understand the mechanisms by which UCs sense hydrostatic pressure.

Electrophysiological Investigation of Hydrostatic Pressure Mechanotransduction by Urothelial Cell Lines

2011 ◽  
Author(s):  
Kevin D. Champaigne ◽  
Sarette N. Jenderny ◽  
Jiro Nagatomi
Keyword(s):  
Hydrostatic Pressure ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Primary Cultures ◽  
Receptor Potential ◽  
Ruthenium Red ◽  
Mechanical Stimuli ◽  
Urothelial Cells ◽  
Membrane Stretch

The urothelium is the epithelial lining of the ureters, urinary bladder, and urethra. Recent discoveries have suggested that in addition to providing a barrier function to urine, the urothelium actively participates in sensory functions related to thermal, chemical, and mechanical stimuli, and releases chemical signals in response[1]. In addition to a sensitivity to cell membrane stretch caused by wall tension upon bladder filling, in vitro studies by our group have shown that urothelial cells may be sensitive to hydrostatic pressure directly without requiring membrane stretching [2]. Specifically, primary cultures of rat bladder urothelial cells exposed to 10 cmH2O pressure on rigid substrates released significantly greater amounts of ATP compared to the baseline control without exposure to pressure. Moreover, this ATP response by rat urothelial cells to pressure was inhibited by pre-treatment of cells with ruthenium red, a non-specific antagonist of transient receptor potential (TRP) channels, suggesting a potential involvement of these channels in pressure mechanotransduction. Further understanding of the mechanisms, however, is needed to improve treatment of bladder dysfunction such as overactive bladder.

scholarly journals The Transient Receptor Potential Vanilloid Type-2 (TRPV2) Ion Channels in Neurogenesis and Gliomagenesis: Cross-Talk between Transcription Factors and Signaling Molecules

Cancers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 322 ◽  
Author(s):  
Giorgio Santoni ◽  
Consuelo Amantini
Keyword(s):  
Ion Channels ◽  
Neural Progenitor Cells ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Receptor Potential ◽  
Transient Receptor Potential Vanilloid ◽  
New Therapeutic Approaches ◽  
Transient Receptor

Recently, the finding of cancer stem cells in brain tumors has increased the possibilitiesfor advancing new therapeutic approaches with the aim to overcome the limits of current availabletreatments. In addition, a role for ion channels, particularly of TRP channels, in developing neuronsas well as in brain cancer development and progression have been demonstrated. Herein, we focuson the latest advancements in understanding the role of TRPV2, a Ca2+ permeable channel belongingto the TRPV subfamily in neurogenesis and gliomagenesis. TRPV2 has been found to be expressedin both neural progenitor cells and glioblastoma stem/progenitor-like cells (GSCs). In developingneurons, post-translational modifications of TRPV2 (e.g., phosphorylation by ERK2) are required tostimulate Ca2+ signaling and nerve growth factor-mediated neurite outgrowth. TRPV2overexpression also promotes GSC differentiation and reduces gliomagenesis in vitro and in vivo.In glioblastoma, TRPV2 inhibits survival and proliferation, and induces Fas/CD95-dependentapoptosis. Furthermore, by proteomic analysis, the identification of a TRPV2 interactome-basedsignature and its relation to glioblastoma progression/recurrence, high or low overall survival anddrug resistance strongly suggest an important role of the TRPV2 channel as a potential biomarkerin glioblastoma prognosis and therapy.

scholarly journals Emerging Roles for Ion Channels in Ovarian Cancer: Pathomechanisms and Pharmacological Treatment

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 668
Author(s):  
Concetta Altamura ◽  
Maria Raffaella Greco ◽  
Maria Rosaria Carratù ◽  
Rosa Angela Cardone ◽  
Jean-François Desaphy
Keyword(s):  
Ovarian Cancer ◽  
Ion Channels ◽  
Transient Receptor Potential ◽  
Critical Role ◽  
Gynecologic Cancer ◽  
Receptor Potential ◽  
Transient Receptor Potential Channels ◽  
Platinum Resistance

Ovarian cancer (OC) is the deadliest gynecologic cancer, due to late diagnosis, development of platinum resistance, and inadequate alternative therapy. It has been demonstrated that membrane ion channels play important roles in cancer processes, including cell proliferation, apoptosis, motility, and invasion. Here, we review the contribution of ion channels in the development and progression of OC, evaluating their potential in clinical management. Increased expression of voltage-gated and epithelial sodium channels has been detected in OC cells and tissues and shown to be involved in cancer proliferation and invasion. Potassium and calcium channels have been found to play a critical role in the control of cell cycle and in the resistance to apoptosis, promoting tumor growth and recurrence. Overexpression of chloride and transient receptor potential channels was found both in vitro and in vivo, supporting their contribution to OC. Furthermore, ion channels have been shown to influence the sensitivity of OC cells to neoplastic drugs, suggesting a critical role in chemotherapy resistance. The study of ion channels expression and function in OC can improve our understanding of pathophysiology and pave the way for identifying ion channels as potential targets for tumor diagnosis and treatment.

scholarly journals The transient receptor potential, TRP4, cation channel is a novel member of the family of calmodulin binding proteins

2001 ◽  
Vol 355 (3) ◽  
pp. 663-670 ◽  
Author(s):  
Claudia TROST ◽  
Christiane BERGS ◽  
Nina HIMMERKUS ◽  
Veit FLOCKERZI
Keyword(s):  
Amino Acid ◽  
Ion Channels ◽  
Transient Receptor Potential ◽  
Direct Interaction ◽  
Receptor Potential ◽  
Amino Acid Residues ◽  
Glutathione S Transferase ◽  
Calmodulin Binding ◽  
Transient Receptor

The mammalian gene products, transient receptor potential (trp)1 to trp7, are related to the Drosophila TRP and TRP-like ion channels, and are candidate proteins underlying agonist-activated Ca2+-permeable ion channels. Recently, the TRP4 protein has been shown to be part of native store-operated Ca2+-permeable channels. These channels, most likely, are composed of other proteins in addition to TRP4. In the present paper we report the direct interaction of TRP4 and calmodulin (CaM) by: (1) retention of in vitro translated TRP4 and of TRP4 protein solubilized from bovine adrenal cortex by CaM–Sepharose in the presence of Ca2+, and (2) TRP4–glutathione S-transferase pull-down experiments. Two domains of TRP4, amino acid residues 688–759 and 786–848, were identified as being able to interact with CaM. The binding of CaM to both domains occurred only in the presence of Ca2+ concentrations above 10µM, with half maximal binding occurring at 16.6µM (domain 1) and 27.9µM Ca2+ (domain 2). Synthetic peptides, encompassing the two putative CaM binding sites within these domains and covering amino acid residues 694–728 and 829–853, interacted directly with dansyl–CaM with apparent Kd values of 94–189nM. These results indicate that TRP4/Ca2+-CaM are parts of a signalling complex involved in agonist-induced Ca2+ entry.

scholarly journals Characterization Of Selective TRPM8 Ligands And Their Structure Activity Response (S.A.R) Relationship

2010 ◽  
Vol 13 (2) ◽  
pp. 242 ◽  
Author(s):  
Muhammad Azhar Sherkheli ◽  
Angela K. Vogt-Eisele ◽  
Daniel Bura ◽  
Leopoldo R. Beltrán Márques ◽  
Günter Gisselmann ◽  
...  
Keyword(s):  
Ion Channels ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Parent Compound ◽  
Receptor Potential ◽  
Basic Research ◽  
Fold Increase ◽  
Ring Structure ◽  
Sensory Nerves ◽  
Transient Receptor Potential Melastatin

PURPOSE: Transient receptor potential melastatin-8 (TRPM8) is an ion channel expressed extensively in sensory nerves, human prostate and overexpressed in a variety of cancers including prostate, breast, lung, colon and skin melanomas. It is activated by innoxious cooling and chemical stimuli. TRPM8 activation by cooling or chemical agonists is reported to induce profound analgesia in neuropathic pain conditions. Known TRPM8 agonists like menthol and icilin cross-activate other thermo-TRP channels like TRPV3 and TRPA1 and mutually inhibit TRPM8. This limits the usefulness of menthol and icilin as TRPM8 ligands. Consequently, the identification of selective and potent ligands for TRPM8 is of high relevance both in basic research and for therapeutic applications. In the present investigation, a group of menthol derivates was characterized. These ligands are selective and potent agonists of TRPM8. Interestingly they do not activate other thermo-TRPs like TRPA1, TRPV1, TRPV2, TRPV3 and TRPV4. These ion channels are also nociceptors and target of many inflammatory mediators. METHODS: Investigations were performed in a recombinant system: Xenopus oocytes microinjected with cRNA of gene of interest were superfused with the test substances after initial responses of known standard agonists. Evoked currents were measured by two-electrode voltage clamp technique. RESULTS: The newly characterized ligands possess an up to six-fold higher potency (EC50 in low µM) and an up to two-fold increase in efficacy compared to the parent compound menthol. In addition, it is found that chemical derivatives of menthol like CPS-368, CPS-369, CPS-125, WS-5 and WS-12 are the most selective ligands for TRPM8. The enhanced activity and selectivity seems to be conferred by hexacyclic ring structure present in all ligands as substances like WS-23 which lack this functional group activate TRPM8 with much lower potency (EC50 in mM) and those with pentacyclcic ring structure (furanone compounds) are totally inactive. CONCLUSION: The new substances activate TRPM8 with a higher potency, efficacy and specificity than menthol and will thus be of importance for the development of pharmacological agents suitable for treatment and diagnosis of certain cancers and as analgesics. STATEMENT OF NOVELTY: The new compounds have an unmatched specificity for TRPM8 ion channels with additional display of high potency and efficacy. Thus these substances are better pharmacological tools for TRPM8 characterization then known compounds and it is suggested that these menthol-derivates may serve as model substances for the development of TRPM8 ligands.

scholarly journals Deciphering the interactions of SARS-CoV-2 proteins with human ion channels using machine learning-based method

2021 ◽  
Author(s):  
Nupur S. Munjal ◽  
Dikscha Sapra ◽  
Abhishek Goyal ◽  
K.T. Shreya Parthasarathi ◽  
Akhilesh Pandey ◽  
...  
Keyword(s):  
Machine Learning ◽  
Ion Channels ◽  
Protein Interactions ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Transmission Rate ◽  
Drug Repurposing ◽  
Receptor Potential ◽  
Ppi Networks ◽  
Approved Drugs

Abstract Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the worldwide COVID-19 pandemic which began in 2019. It has a high transmission rate and pathogenicity leading to health emergencies and economic crisis. Recent studies pertaining to the understanding of the molecular pathogenesis of SARS-CoV-2 infection exhibited the indispensable role of ion channels in viral infection inside the host. Moreover, machine learning-based algorithms are providing higher accuracy for host-SARS-CoV-2 protein-protein interactions (PPIs). In this study, predictions of PPIs of SARS-CoV-2 proteins with human ion channels (HICs) were performed using PPI-MetaGO algorithm. The PPIs were predicted with 82.71% accuracy, 84.09% precision, 84.09% sensitivity, 0.89 AUC-ROC, 65.17% MCC score and 84.09% F1 score. Thereafter, PPI networks of SARS-CoV-2 proteins with HICs were generated. Furthermore, biological pathway analysis of HICs interacting with SARS-CoV-2 proteins showed the involvement of six pathways, namely inflammatory mediator regulation of TRP channels, insulin secretion, renin secretion, gap junction, taste transduction and apelin signaling pathway. The inositol 1,4,5-trisphosphate receptor 1 (ITPR1) and transient receptor potential cation channel subfamily A member 1 (TRPA1) were identified as potential target proteins. Various FDA approved drugs interacting with ITPR1 and TRPA1 are also available. It is anticipated that targeting ITPR1 and TRPA1 may provide a better therapeutic management of infection caused by SARS-CoV-2. The study also reinforces the drug repurposing approach for the development of host directed antiviral drugs.

scholarly journals Transient Receptor Potential Cation Channels in Cancer Therapy

2019 ◽  
Vol 7 (12) ◽  
pp. 108 ◽  
Author(s):  
Giorgio Santoni ◽  
Federica Maggi ◽  
Maria Beatrice Morelli ◽  
Matteo Santoni ◽  
Oliviero Marinelli
Keyword(s):  
Cell Proliferation ◽  
Cell Death ◽  
Cancer Cells ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Receptor Potential ◽  
Chemotherapeutic Agents ◽  
Migration And Invasion ◽  
Transient Receptor

In mammals, the transient receptor potential (TRP) channels family consists of six different families, namely TRPC (canonical), TRPV (vanilloid), TRPM (melastatin), TRPML (mucolipin), TRPP (polycystin), and TRPA (ankyrin), that are strictly connected with cancer cell proliferation, differentiation, cell death, angiogenesis, migration, and invasion. Changes in TRP channels’ expression and function have been found to regulate cell proliferation and resistance or sensitivity of cancer cells to apoptotic-induced cell death, resulting in cancer-promoting effects or resistance to chemotherapy treatments. This review summarizes the data reported so far on the effect of targeting TRP channels in different types of cancer by using multiple TRP-specific agonists, antagonists alone, or in combination with classic chemotherapeutic agents, microRNA specifically targeting the TRP channels, and so forth, and the in vitro and in vivo feasibility evaluated in experimental models and in cancer patients. Considerable efforts have been made to fight cancer cells, and therapies targeting TRP channels seem to be the most promising strategy. However, more in-depth investigations are required to completely understand the role of TRP channels in cancer in order to design new, more specific, and valuable pharmacological tools.

Transient receptor potential ion channels as participants in thermosensation and thermoregulation

2007 ◽  
Vol 292 (1) ◽  
pp. R64-R76 ◽  
Author(s):  
Michael J. Caterina
Keyword(s):  
Ion Channels ◽  
Molecular Mechanisms ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Core Body Temperature ◽  
Expression Patterns ◽  
Receptor Potential ◽  
Genetic Ablation ◽  
Transient Receptor ◽  
Living Organisms

Living organisms must evaluate changes in environmental and internal temperatures to mount appropriate physiological and behavioral responses conducive to survival. Classical physiology has provided a wealth of information regarding the specialization of thermosensory functions among subclasses of peripheral sensory neurons and intrinsically thermosensitive neurons within the hypothalamus. However, until recently, the molecular mechanisms by which these cells carry out thermometry have remained poorly understood. The demonstration that certain ion channels of the transient receptor potential (TRP) family can be activated by increases or decreases in ambient temperature, along with the recognition of their heterogeneous expression patterns and heterogeneous temperature sensitivities, has led investigators to evaluate these proteins as candidate endogenous thermosensors. Much of this work has involved one specific channel, TRP vanilloid 1 (TRPV1), which is both a receptor for capsaicin and related pungent vanilloid compounds and a “heat receptor,” capable of directly depolarizing neurons in response to temperatures >42°C. Evidence for a contribution of TRPV1 to peripheral thermosensation has come from pharmacological, physiological, and genetic approaches. In contrast, although capsaicin-sensitive mechanisms clearly influence core body temperature regulation, the specific contribution of TRPV1 to this process remains a matter of debate. Besides TRPV1, at least six additional thermally sensitive TRP channels have been identified in mammals, and many of these also appear to participate in thermosensation. Moreover, the identification of invertebrate TRP channels, whose genetic ablation alters thermally driven behaviors, makes it clear that thermosensation represents an evolutionarily conserved role of this ion channel family.

scholarly journals Ion channels alterations in the forebrain of high-fat diet fed rats

2021 ◽  
Vol 65 (s1) ◽  
Author(s):  
Proshanta Roy ◽  
Ilenia Martinelli ◽  
Michele Moruzzi ◽  
Federica Maggi ◽  
Consuelo Amantini ◽  
...  
Keyword(s):  
Ion Channels ◽  
Western Blot ◽  
High Fat Diet ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Receptor Potential ◽  
Acid Oxidation ◽  
Standard Diet ◽  
High Fat ◽  
Qrt Pcr

Evidence suggests that transient receptor potential (TRP) ion channels dysfunction significantly contributes to the physiopathology of metabolic and neurological disorders. Dysregulation in functions and expression in genes encoding the TRP channels cause several inherited diseases in humans (the so-called ‘TRP channelopathies’), which affect the cardiovascular, renal, skeletal, and nervous systems. This study aimed to evaluate the expression of ion channels in the forebrain of rats with diet-induced obesity (DIO). DIO rats were studied after 17 weeks under a hypercaloric diet (high-fat diet, HFD) and were compared to the control rats with a standard diet (CHOW). To determine the systemic effects of HFD exposure, we examined food intake, fat mass content, fasting glycemia, insulin levels, cholesterol, and triglycerides. qRT-PCR, Western blot, and immunochemistry analysis were performed in the frontal cortex (FC) and hippocampus (HIP). After 17 weeks of HFD, DIO rats increased their body weight significantly compared to the CHOW rats. In DIO rats, TRPC1 and TRPC6 were upregulated in the HIP, while they were downregulated in the FC. In the case of TRPM2 expression, instead was increased both in the HIP and in the FC. These could be related to the increase of proteins and nucleic acid oxidation. TRPV1 and TRPV2 gene expression showed no differences both in the FC and HIP. In general, qRT-PCR analyses were confirmed by Western blot analysis. Immunohistochemical procedures highlighted the expression of the channels in the cell body of neurons and axons, particularly for the TRPC1 and TRPC6. The alterations of TRP channel expression could be related to the activation of glial cells or the neurodegenerative process presented in the brain of the DIO rat highlighted with post synaptic protein (PSD 95) alterations. The availability of suitable animal models may be useful for studying possible pharmacological treatments to counter obesity-induced brain injury. The identified changes in DIO rats may represent the first insight to characterize the neuronal alterations occurring in obesity. Further investigations are necessary to characterize the role of TRP channels in the regulation of synaptic plasticity and obesity-related cognitive decline.

scholarly journals Deciphering the interactions of SARS-CoV-2 proteins with human ion channels using machine learning-based method

2021 ◽  
Author(s):  
Nupur S. Munjal ◽  
Dikscha Sapra ◽  
Abhishek Goyal ◽  
K.T. Shreya Parthasarathi ◽  
Akhilesh Pandey ◽  
...  
Keyword(s):  
Machine Learning ◽  
Ion Channels ◽  
Gap Junction ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Receptor Potential ◽  
Cation Channel ◽  
Ppi Networks ◽  
Junction Protein ◽  
Transient Receptor

Abstract Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the worldwide COVID-19 pandemic which began in 2019. It has a high transmission rate and pathogenicity leading to health emergencies and economic crisis. Recent studies pertaining to the understanding of the molecular pathogenesis of SARS-CoV-2 infection exhibited the indispensable role of ion channels in viral infection inside the host. Moreover, machine learning (ML)-based algorithms are providing higher accuracy for host-SARS-CoV-2 protein-protein interactions (PPIs). In this study, predictions of PPIs of SARS-CoV-2 proteins with human ion channels (HICs) were performed using PPI-MetaGO algorithm. The PPIs were predicted with 82.71% accuracy, 84.09% precision, 84.09% sensitivity, 0.89 AUC-ROC, 65.17% Matthews correlation coefficient (MCC) score and 84.09% F1 score. Thereafter, PPI networks of SARSCoV-2 proteins with HICs were generated. Furthermore, biological pathway analysis of HICs interacting with SARS-CoV-2 proteins showed the involvement of six pathways, namely inflammatory mediator regulation of transient receptor potential (TRP) channels, insulin secretion, renin secretion, gap junction, taste transduction and apelin signaling pathway. Our analysis suggests that transient receptor potential cation channel subfamily M member 4 (TRPM4), transient receptor potential cation channel subfamily A member 1 (TRPA1), gap junction protein alpha 1 (GJA1), potassium calcium-activated channel subfamily N member 4 (KCNN4), acid sensing ion channel subunit 1 (ASIC1) and inositol 1,4,5-trisphosphate receptor type 1 (ITPR1) could serve as an initial set to the experimentalists for further validation. Additionally, various US food and drug administration (FDA) approved drugs interacting with the potential HICs were also identified. The study also reinforcesthe drug repurposing approach for the development of host directed antiviral drugs.

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