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 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 Binding Efficacy and Thermogenic Efficiency of Pungent and Nonpungent Analogs of Capsaicin

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3198 ◽  
Author(s):  
Padmamalini Baskaran ◽  
Kyle Covington ◽  
Jane Bennis ◽  
Adithya Mohandass ◽  
Teresa Lehmann ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Molecular Docking ◽  
Energy Expenditure ◽  
High Fat Diet ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Docking Studies ◽  
Transient Receptor Potential Vanilloid ◽  
Metabolic Dysfunction ◽  
High Fat

(1) Background: Capsaicin, a chief ingredient of natural chili peppers, enhances metabolism and energy expenditure and stimulates the browning of white adipose tissue (WAT) and brown fat activation to counter diet-induced obesity. Although capsaicin and its nonpungent analogs are shown to enhance energy expenditure, their efficiency to bind to and activate their receptor—transient receptor potential vanilloid subfamily 1 (TRPV1)—to mediate thermogenic effects remains unclear. (2) Methods: We analyzed the binding efficiency of capsaicin analogs by molecular docking. We fed wild type mice a normal chow or high fat diet (± 0.01% pungent or nonpungent capsaicin analog) and isolated inguinal WAT to analyze the expression of thermogenic genes and proteins. (3) Results: Capsaicin, but not its nonpungent analogs, efficiently binds to TRPV1, prevents high fat diet-induced weight gain, and upregulates thermogenic protein expression in WAT. Molecular docking studies indicate that capsaicin exhibits the highest binding efficacy to TRPV1 because it has a hydrogen bond that anchors it to TRPV1. Capsiate, which lacks the hydrogen bond, and therefore, does not anchor to TRPV1. (4) Conclusions: Long-term activation of TRPV1 is imminent for the anti-obesity effect of capsaicin. Efforts to decrease the pungency of capsaicin will help in advancing it to mitigate obesity and metabolic dysfunction in humans.

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.

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 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.

scholarly journals PIRT the TRP Channel Regulating Protein Binds Calmodulin and Cholesterol-Like Ligands

Biomolecules ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 478 ◽  
Author(s):  
Nicholas J. Sisco ◽  
Dustin D. Luu ◽  
Minjoo Kim ◽  
Wade D. Van Horn
Keyword(s):  
Ion Channels ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Transmembrane Helix ◽  
Receptor Potential ◽  
Outer Leaflet ◽  
Heat Sensor ◽  
Transient Receptor ◽  
Α Helix ◽  
Obesity And Cancer

Transient receptor potential (TRP) ion channels are polymodal receptors that have been implicated in a variety of pathophysiologies, including pain, obesity, and cancer. The capsaicin and heat sensor TRPV1, and the menthol and cold sensor TRPM8, have been shown to be modulated by the membrane protein PIRT (Phosphoinositide-interacting regulator of TRP). The emerging mechanism of PIRT-dependent TRPM8 regulation involves a competitive interaction between PIRT and TRPM8 for the activating phosphatidylinositol 4,5-bisphosphate (PIP2) lipid. As many PIP2 modulated ion channels also interact with calmodulin, we investigated the possible interaction between PIRT and calmodulin. Using microscale thermophoresis (MST), we show that calmodulin binds to the PIRT C-terminal α-helix, which we corroborate with a pull-down experiment, nuclear magnetic resonance-detected binding study, and Rosetta-based computational studies. Furthermore, we identify a cholesterol-recognition amino acid consensus (CRAC) domain in the outer leaflet of the first transmembrane helix of PIRT, and with MST, show that PIRT specifically binds to a number of cholesterol-derivatives. Additional studies identified that PIRT binds to cholecalciferol and oxytocin, which has mechanistic implications for the role of PIRT regulation of additional ion channels. This is the first study to show that PIRT specifically binds to a variety of ligands beyond TRP channels and PIP2.

Transient Receptor Potential (TRP) Channels in the Brain: the Good and the Ugly

2012 ◽  
Vol 20 (3) ◽  
pp. 343-355 ◽  
Author(s):  
Bernd Nilius
Keyword(s):  
Ion Channels ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Receptor Potential ◽  
Sensory Function ◽  
Short Paper ◽  
The Novel ◽  
Cellular Functions ◽  
Transient Receptor ◽  
The Brain

The ‘transient receptor potential’ (TRP) multigene family encodes sixspan membrane proteins that function as ion channels in mostly tetrameric structures. Members of this family are conserved from yeast, worm, fly to invertebrate, vertebrate and man. These channels have been stigmatized to function only as cell sensors occupied by sensory function. It turns out that TRP channels fulfil a plethora of cellular functions, including non-sensory functions in our brain. This short paper will highlight the advent of novel ion channels in the brain serving different functions and being significantly involved in the genesis of multiple diseases. We will certainly witness a plethora of the novel roles of this protein family in physiological and pathophysiological functions in our central nervous system.

scholarly journals Dysfunction of transient receptor potential ion channels as an important pathophysiological mechanism in asthma

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Oxana Yu. Kytikova ◽  
Tatyana P. Novgorodtseva ◽  
Yulia K. Denisenko ◽  
Marina V. Antonyuk ◽  
Tatyana A. Gvozdenko
Keyword(s):  
Ion Channels ◽  
Neurogenic Inflammation ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Receptor Potential ◽  
Bronchial Hyperreactivity ◽  
Pathophysiological Mechanism ◽  
Lung Pathology ◽  
Trp Ion Channels ◽  
Transient Receptor

Asthma is a chronic heterogeneous disease characterized by chronic inflammation and bronchial hyperreactivity. Neurogenic inflammation is one of the important causes of hyperreactivity. Dysfunction of transient receptor potential (TRP) ion channels underlies the development of neurogenic inflammation, bronchial hyperreactivity and respiratory symptoms of asthma such as bronchospasm and cough. TRP channels are expressed in the respiratory tract. Their activation is mediated by endogenous and exogenous factors involved in the pathogenesis of asthma. The study of functioning and regulation of TRP channels is relevant, as they could be important therapeutic targets for asthma. The aim of the review is to summarize modern ideas about the mechanisms of functioning and regulation of members of the TRP channel superfamily, the role of which in lung pathology and physiology are the best studied.

Effect of high fat diet on mechanosensitive TRP channel activation in vagal afferent neurons

2020 ◽  
Author(s):  
Sung Jin Park ◽  
Yang Yu ◽  
Michael J. Beyak
Keyword(s):  
Mechanical Stimulation ◽  
High Fat Diet ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Imaging Techniques ◽  
Vagal Afferents ◽  
Trp Channel ◽  
Hypotonic Solution ◽  
High Fat ◽  
Diet Induced Obesity

Mechanical stimulation of the gastrointestinal tract is an important stimulus of satiety and can be transduced by transient receptor potential (TRP) channels. Several studies have revealed attenuated vagally-mediated satiety responses including mechanosensitivity in diet-induced obesity. However, ion channels underlying this hyposensitivity have not been fully understood. This study aimed to examine the effect of chronic high fat diet on activation of selected mechanosensitive TRP channels in vagal afferents. C57/BL6 mice were fed on either a high-fat or low-fat diet for 6-8 weeks. Increase in the intracellular calcium to hypotonic solution and activators of TRPV1, TRPV4, TRPA1 was measured in nodose neurons using Ca2+-imaging techniques. Jejunal afferent nerve firing induced by mechanical stimulation and TRP channel agonists was measured using in vitro extracellular multi-unit afferent recording. In high fat fed mice, we observed reduced calcium influx and jejunal afferent response induced by mechanical stimuli and agonists of TRPV4 and TRPA1, but not TRPV1. Our data show diet-induced obesity disrupts the activation of TRPV4 and TRPA1, at both the cellular level and the level of nerve terminals in the small intestine, which may partly explain reduced mechanosensitivity of vagal afferents and may contribute to decreased gut-brain satiety signaling in obesity.

scholarly journals Opening TRPP2 (PKD2L1) requires the transfer of gating charges

2019 ◽  
Vol 116 (31) ◽  
pp. 15540-15549 ◽  
Author(s):  
Leo C. T. Ng ◽  
Thuy N. Vien ◽  
Vladimir Yarov-Yarovoy ◽  
Paul G. DeCaen
Keyword(s):  
Ion Channels ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Receptor Potential ◽  
Voltage Gated ◽  
State Dependent ◽  
Transient Receptor ◽  
Voltage Gated Ion Channels ◽  
Gating Charges ◽  
Gated Ion Channels

The opening of voltage-gated ion channels is initiated by transfer of gating charges that sense the electric field across the membrane. Although transient receptor potential ion channels (TRP) are members of this family, their opening is not intrinsically linked to membrane potential, and they are generally not considered voltage gated. Here we demonstrate that TRPP2, a member of the polycystin subfamily of TRP channels encoded by the PKD2L1 gene, is an exception to this rule. TRPP2 borrows a biophysical riff from canonical voltage-gated ion channels, using 2 gating charges found in its fourth transmembrane segment (S4) to control its conductive state. Rosetta structural prediction demonstrates that the S4 undergoes ∼3- to 5-Å transitional and lateral movements during depolarization, which are coupled to opening of the channel pore. Here both gating charges form state-dependent cation–π interactions within the voltage sensor domain (VSD) during membrane depolarization. Our data demonstrate that the transfer of a single gating charge per channel subunit is requisite for voltage, temperature, and osmotic swell polymodal gating of TRPP2. Taken together, we find that irrespective of stimuli, TRPP2 channel opening is dependent on activation of its VSDs.

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