scholarly journals Molecular Basis of TRPA1 Regulation in Nociceptive Neurons. A Review

2017 ◽  
pp. 425-439 ◽  
Author(s):  
A. KÁDKOVÁ ◽  
V. SYNYTSYA ◽  
J. KRUSEK ◽  
L. ZÍMOVÁ ◽  
V. VLACHOVÁ

Transient receptor potential A1 (TRPA1) is an excitatory ion channel that functions as a cellular sensor, detecting a wide range of proalgesic agents such as environmental irritants and endogenous products of inflammation and oxidative stress. Topical application of TRPA1 agonists produces an acute nociceptive response through peripheral release of neuropeptides, purines and other transmitters from activated sensory nerve endings. This, in turn, further regulates TRPA1 activity downstream of G-protein and phospholipase C-coupled signaling cascades. Despite the important physiological relevance of such regulation leading to nociceptor sensitization and consequent pain hypersensitivity, the specific domains through which TRPA1 undergoes post-translational modifications that affect its activation properties are yet to be determined at a molecular level. This review aims at providing an account of our current knowledge on molecular basis of regulation by neuronal inflammatory signaling pathways that converge on the TRPA1 channel protein and through modification of its specific residues influence the extent to which this channel may contribute to pain.

2021 ◽  
Vol 22 (7) ◽  
pp. 3360
Author(s):  
Mee-Ra Rhyu ◽  
Yiseul Kim ◽  
Vijay Lyall

In addition to the sense of taste and olfaction, chemesthesis, the sensation of irritation, pungency, cooling, warmth, or burning elicited by spices and herbs, plays a central role in food consumption. Many plant-derived molecules demonstrate their chemesthetic properties via the opening of transient receptor potential ankyrin 1 (TRPA1) and transient receptor potential vanilloid 1 (TRPV1) channels. TRPA1 and TRPV1 are structurally related thermosensitive cation channels and are often co-expressed in sensory nerve endings. TRPA1 and TRPV1 can also indirectly influence some, but not all, primary taste qualities via the release of substance P and calcitonin gene-related peptide (CGRP) from trigeminal neurons and their subsequent effects on CGRP receptor expressed in Type III taste receptor cells. Here, we will review the effect of some chemesthetic agonists of TRPA1 and TRPV1 and their influence on bitter, sour, and salt taste qualities.


Author(s):  
Sanjeev K. Singh ◽  
M. S. Muthu ◽  
Ravindran Revand ◽  
M. B. Mandal

Background: Since long back, it has been a matter of discussion regarding the role of peripheral blood vessels in regulation of cardiorespiratory (CVR) system. Objective: The role of 5-HT3 and TRPV1 receptors present on perivascular nerves in elicitation of CVR reflexes was examined after intra-arterial instillation of bradykinin in urethane anesthetized rats. Materials and Methods: Femoral artery was cannulated retrogradely and was utilized for the instillation of saline/agonist/antagonist and recording of blood pressure (BP), using a double ported 24G cannula. BP, respiration and ECG were recorded for 30 min after bradykinin (1 µM) in the absence or presence of antagonists. Results: Instillation of bradykinin produced immediate hypotensive (40%), bradycardiac (17%), tachypnoeic (45%) and hyperventilatory (96%) responses of shorter latencies (5-8 s) favoring the neural mechanisms in producing the responses. In lignocaine (2%) pretreated animals, bradykinin-induced hypotensive (10%), bradycardiac (1.7%), tachypnoeic (13%) and hyperventilatory (13%) responses attenuated significantly. Pretreatment with ondansetron (100 µg/kg), 5-HT3-antagonist attenuated the hypotensive (10%), bradycardiac (1.7%), tachypnoeic (11%) and hyperventilatory (11%) responses significantly. Pretreatment with capsazepine (1 mg/kg), transient receptor potential vanilloid 1- antagonist blocked the hypotensive (5%), bradycardiac (1.2%), tachypnoeic (6%) and hyperventilatory (6%) responses significantly. Conclusion: In conclusion, presence of a nociceptive agent in the local segment of an artery evokes vasosensory reflex responses modulating CVR parameters involving TRPV1 and 5-HT3 receptors present on the perivascular sensory nerve terminals in anesthetized rats.


2008 ◽  
Vol 294 (5) ◽  
pp. G1288-G1298 ◽  
Author(s):  
Walter E. B. Sipe ◽  
Stuart M. Brierley ◽  
Christopher M. Martin ◽  
Benjamin D. Phillis ◽  
Francisco Bautista Cruz ◽  
...  

Protease-activated receptor (PAR2) is expressed by nociceptive neurons and activated during inflammation by proteases from mast cells, the intestinal lumen, and the circulation. Agonists of PAR2 cause hyperexcitability of intestinal sensory neurons and hyperalgesia to distensive stimuli by unknown mechanisms. We evaluated the role of the transient receptor potential vanilloid 4 (TRPV4) in PAR2-induced mechanical hyperalgesia of the mouse colon. Colonic sensory neurons, identified by retrograde tracing, expressed immunoreactive TRPV4, PAR2, and calcitonin gene-related peptide and are thus implicated in nociception. To assess nociception, visceromotor responses (VMR) to colorectal distension (CRD) were measured by electromyography of abdominal muscles. In TRPV4+/+ mice, intraluminal PAR2 activating peptide (PAR2-AP) exacerbated VMR to graded CRD from 6–24 h, indicative of mechanical hyperalgesia. PAR2-induced hyperalgesia was not observed in TRPV4−/− mice. PAR2-AP evoked discharge of action potentials from colonic afferent neurons in TRPV4+/+ mice, but not from TRPV4−/− mice. The TRPV4 agonists 5′,6′-epoxyeicosatrienoic acid and 4α-phorbol 12,13-didecanoate stimulated discharge of action potentials in colonic afferent fibers and enhanced current responses recorded from retrogradely labeled colonic dorsal root ganglia neurons, confirming expression of functional TRPV4. PAR2-AP enhanced these responses, indicating sensitization of TRPV4. Thus TRPV4 is expressed by primary spinal afferent neurons innervating the colon. Activation of PAR2 increases currents in these neurons, evokes discharge of action potentials from colonic afferent fibers, and induces mechanical hyperalgesia. These responses require the presence of functional TRPV4. Therefore, TRPV4 is required for PAR2-induced mechanical hyperalgesia and excitation of colonic afferent neurons.


2020 ◽  
Vol 100 (2) ◽  
pp. 725-803 ◽  
Author(s):  
Karel Talavera ◽  
Justyna B. Startek ◽  
Julio Alvarez-Collazo ◽  
Brett Boonen ◽  
Yeranddy A. Alpizar ◽  
...  

The transient receptor potential ankyrin (TRPA) channels are Ca2+-permeable nonselective cation channels remarkably conserved through the animal kingdom. Mammals have only one member, TRPA1, which is widely expressed in sensory neurons and in non-neuronal cells (such as epithelial cells and hair cells). TRPA1 owes its name to the presence of 14 ankyrin repeats located in the NH2 terminus of the channel, an unusual structural feature that may be relevant to its interactions with intracellular components. TRPA1 is primarily involved in the detection of an extremely wide variety of exogenous stimuli that may produce cellular damage. This includes a plethora of electrophilic compounds that interact with nucleophilic amino acid residues in the channel and many other chemically unrelated compounds whose only common feature seems to be their ability to partition in the plasma membrane. TRPA1 has been reported to be activated by cold, heat, and mechanical stimuli, and its function is modulated by multiple factors, including Ca2+, trace metals, pH, and reactive oxygen, nitrogen, and carbonyl species. TRPA1 is involved in acute and chronic pain as well as inflammation, plays key roles in the pathophysiology of nearly all organ systems, and is an attractive target for the treatment of related diseases. Here we review the current knowledge about the mammalian TRPA1 channel, linking its unique structure, widely tuned sensory properties, and complex regulation to its roles in multiple pathophysiological conditions.


2013 ◽  
Vol 6 (1) ◽  
pp. 50-61 ◽  
Author(s):  
E.S. Fernandes ◽  
S. Awal ◽  
R. Karadaghi ◽  
S.D. Brain

Arthritis is a condition characterised by mainly pain, reduced joint movement and signs of inflammation, such as swelling. The disorder has many different types, of which osteoarthritis (a degenerative joint disease) and rheumatoid arthritis (a chronic autoimmune disease) are the two most common forms. There are >6 million sufferers in the UK and both conditions have a huge potential to impair capabilities and contribute to social and economic burdens. Whilst there are a wide range of arthritic therapies available, many patients under treatment complain of poor pain relief. Thus there is a need for novel therapeutic approaches, and the transient receptor potential (TRP) family of receptor channels has been investigated. One particular area of recent research has been the ligand-gated transient receptor potential vanilloid 1 (TRPV1) channel. Findings from numerous pre-clinical models and scientific studies have shown that TRPV1 desensitisation, or the use of TRPV1 antagonists alleviates pain and some inflammatory aspects. New findings have started to unveil the potential of other TRP channels in mediating arthritic pain and inflammation. With the understanding that the currently available treatments for arthritis are limited, researchers have looked into the exciting prospect that TRP receptor antagonists may be developed into effective, specific drugs, which would potentially protect against the complications of arthritis. These antagonists are still under development, although only data from studies from pre-clinical models are currently available. This review acts to summarize knowledge of the potential influence of TRP receptors in arthritis to date.


2021 ◽  
Vol 12 ◽  
Author(s):  
Trine L. Toft-Bertelsen ◽  
Nanna MacAulay

The transient receptor potential vanilloid 4 channel (TRPV4) is a non-selective cation channel that is widely expressed and activated by a range of stimuli. Amongst these stimuli, changes in cell volume feature as a prominent regulator of TRPV4 activity with cell swelling leading to channel activation. In experimental settings based on abrupt introduction of large osmotic gradients, TRPV4 activation requires co-expression of an aquaporin (AQP) to facilitate such cell swelling. However, TRPV4 readily responds to cell volume increase irrespectively of the molecular mechanism underlying the cell swelling and can, as such, be considered a sensor of increased cell volume. In this review, we will discuss the proposed events underlying the molecular coupling from cell swelling to channel activation and present the evidence of direct versus indirect swelling-activation of TRPV4. With this summary of the current knowledge of TRPV4 and its ability to sense cell volume changes, we hope to stimulate further experimental efforts in this area of research to clarify TRPV4’s role in physiology and pathophysiology.


2020 ◽  
Vol 21 (14) ◽  
pp. 5019
Author(s):  
Maja Payrits ◽  
Ádám Horváth ◽  
Tünde Biró-Sütő ◽  
János Erostyák ◽  
Géza Makkai ◽  
...  

Transient Receptor Potential Vanilloid 1 and Ankyrin 1 (TRPV1, TRPA1) cation channels are expressed in nociceptive primary sensory neurons and regulate nociceptor and inflammatory functions. Resolvins are endogenous lipid mediators. Resolvin D1 (RvD1) is described as a selective inhibitor of TRPA1-related postoperative and inflammatory pain in mice acting on the G protein-coupled receptor DRV1/GPR32. Resolvin D2 (RvD2) is a very potent TRPV1 and TRPA1 inhibitor in DRG neurons, and decreases inflammatory pain in mice acting on the GPR18 receptor, via TRPV1/TRPA1-independent mechanisms. We provided evidence that resolvins inhibited neuropeptide release from the stimulated sensory nerve terminals by TRPV1 and TRPA1 activators capsaicin (CAPS) and allyl-isothiocyanate (AITC), respectively. We showed that RvD1 and RvD2 in nanomolar concentrations significantly decreased TRPV1 and TRPA1 activation on sensory neurons by fluorescent calcium imaging and inhibited the CAPS- and AITC-evoked 45Ca-uptake on TRPV1- and TRPA1-expressing CHO cells. Since CHO cells are unlikely to express resolvin receptors, resolvins are suggested to inhibit channel opening through surrounding lipid raft disruption. Here, we proved the ability of resolvins to alter the membrane polarity related to cholesterol composition by fluorescence spectroscopy. It is concluded that targeting lipid raft integrity can open novel peripheral analgesic opportunities by decreasing the activation of nociceptors.


Scientifica ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Nelson S. Yee ◽  
Ada S. Chan ◽  
Julian D. Yee ◽  
Rosemary K. Yee

Transient receptor potential (TRP) ion channels are essential for normal functions and health by acting as molecular sensors and transducing various stimuli into cellular and physiological responses. Growing evidence has revealed that TRP ion channels play important roles in a wide range of human diseases, including malignancies. In light of recent discoveries, it has been found that TRP melastatin-subfamily members, TRPM7 and TRPM8, are required for normal and cancerous development of exocrine pancreas. We are currently investigating the mechanisms which mediate the functional roles of TRPM7 and TRPM8 and attempting to develop these ion channels as clinical biomarkers and therapeutic targets for achieving the goal of personalized therapy in pancreatic cancer.


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