scholarly journals The industrial solvent 1,4-dioxane causes hyperalgesia by targeting capsaicin receptor TRPV1

BMC Biology ◽  
2022 ◽  
Vol 20 (1) ◽  
Author(s):  
Xiaoyi Mo ◽  
Qiang Liu ◽  
Luna Gao ◽  
Chang Xie ◽  
Xin Wei ◽  
...  

Abstract Background The synthetic chemical 1,4-dioxane is used as industrial solvent, food, and care product additive. 1,4-Dioxane has been noted to influence the nervous system in long-term animal experiments and in humans, but the molecular mechanisms underlying its effects on animals were not previously known. Results Here, we report that 1,4-dioxane potentiates the capsaicin-sensitive transient receptor potential (TRP) channel TRPV1, thereby causing hyperalgesia in mouse model. This effect was abolished by CRISPR/Cas9-mediated genetic deletion of TRPV1 in sensory neurons, but enhanced under inflammatory conditions. 1,4-Dioxane lowered the temperature threshold for TRPV1 thermal activation and potentiated the channel sensitivity to agonistic stimuli. 1,3-dioxane and tetrahydrofuran which are structurally related to 1,4-dioxane also potentiated TRPV1 activation. The residue M572 in the S4-S5 linker region of TRPV1 was found to be crucial for direct activation of the channel by 1,4-dioxane and its analogs. A single residue mutation M572V abrogated the 1,4-dioxane-evoked currents while largely preserving the capsaicin responses. Our results further demonstrate that this residue exerts a gating effect through hydrophobic interactions and support the existence of discrete domains for multimodal gating of TRPV1 channel. Conclusions Our results suggest TRPV1 is a co-receptor for 1,4-dioxane and that this accounts for its ability to dysregulate body nociceptive sensation.

2016 ◽  
Vol 68 (Suppl. 2) ◽  
pp. 19-23 ◽  
Author(s):  
Daniel G. Bichet

Disorders of water balance are a common feature of clinical practice. An understanding of the physiology and pathophysiology of central vasopressin release and perception of thirst is the key to diagnosis and management of these disorders. Mammals are osmoregulators; they have evolved mechanisms that maintain extracellular fluid osmolality near a stable value, and, in animal studies, osmoregulatory neurons express a truncated delta-N variant of the transient receptor potential vannilloid (TRPV1) channel involved in hypertonicity and thermal perception while systemic hypotonicity might be perceived by TRPV4 channels. Recent cellular and optogenetic animal experiments demonstrate that, in addition to the multifactorial process of excretion, circumventricular organ sensors reacting to osmotic pressure and angiotensin II, subserve genesis of thirst, volume regulation and behavioral effects of thirst avoidance.


2021 ◽  
Author(s):  
Javier Casas ◽  
Clara Meana ◽  
José Ramón López-López ◽  
Jesús Balsinde ◽  
María A. Balboa

ABSTRACTToll-like receptor 4, the receptor for bacterial lipopolysaccharide (LPS), drives inflammatory responses that protect against pathogens and boost the adaptive immunity. LPS responses are known to depend on calcium fluxes, but the molecular mechanisms involved are poorly understood. Here we present evidence that the transient receptor potential canonical channel 3 (TRPC3) is activated intracellularly during macrophage exposure to LPS and is essential for Ca2+ release from internal stores. In this way TRPC3 participates in cytosolic Ca2+ elevations, TLR4 endocytosis, activation of inflammatory transcription factors and cytokine upregulation. We also report that TRPC3 is activated by diacylglycerol (DAG) generated by the phosphatidic acid phosphatase lipin-1. In accord with this, lipin-1-deficient cells show reduced Ca2+ responses to LPS challenge. A cameleon indicator directed to the endoplasmic reticulum shows that this is the organelle from which TRPC3 mediates the Ca2+ release. Finally, pharmacological inhibition of TRPC3 reduces systemic inflammation induced by LPS in mice. Collectively, our study unveils a central component of LPS-triggered Ca2+ signaling that involves intracellular sensing of lipin-1-derived DAG by TRPC3.


2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Zhi-Chuan Sun ◽  
Sui-Bin Ma ◽  
Wen-Guang Chu ◽  
Dong Jia ◽  
Ceng Luo

Chronic pathological pain is one of the most intractable clinical problems faced by clinicians and can be devastating for patients. Despite much progress we have made in understanding chronic pain in the last decades, its underlying mechanisms remain elusive. It is assumed that abnormal increase of calcium levels in the cells is a key determinant in the transition from acute to chronic pain. Exploring molecular players mediating Ca2+ entry into cells and molecular mechanisms underlying activity-dependent changes in Ca2+ signaling in the somatosensory pain pathway is therefore helpful towards understanding the development of chronic, pathological pain. Canonical transient receptor potential (TRPC) channels form a subfamily of nonselective cation channels, which permit the permeability of Ca2+ and Na+ into the cells. Initiation of Ca2+ entry pathways by these channels triggers the development of many physiological and pathological functions. In this review, we will focus on the functional implication of TRPC channels in nociception with the elucidation of their role in the detection of external stimuli and nociceptive hypersensitivity.


Author(s):  
Bhupesh Vaidya ◽  
Shyam Sunder Sharma

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by the symptoms of motor deficits and cognitive decline. There are a number of therapeutics available for the treatment of PD, but most of them suffer from serious side effects such as bradykinesia, dyskinesia and on-off effect. Therefore, despite the availability of these pharmacological agents, PD patients continue to have an inferior quality of life. This has warranted a need to look for alternate strategies and molecular targets. Recent evidence suggests the Transient Receptor Potential (TRP) channels could be a potential target for the management of motor and non-motor symptoms of PD. Though still in the preclinical stages, agents targeting these channels have shown immense potential in the attenuation of behavioral deficits and signaling pathways. In addition, these channels are known to be involved in the regulation of ionic homeostasis, which is disrupted in PD. Moreover, activation or inhibition of many of the TRP channels by calcium and oxidative stress has also raised the possibility of their paramount involvement in affecting the other molecular mechanisms associated with PD pathology. However, due to the paucity of information available and lack of specificity, none of these agents have gone into clinical trials for PD treatment. Considering their interaction with oxidative stress, apoptosis and excitotoxicity, TRP channels could be considered as a potential future target for the treatment of PD.


2006 ◽  
Vol 85 (10) ◽  
pp. 900-904 ◽  
Author(s):  
C.-K. Park ◽  
H.Y. Li ◽  
K.-Y. Yeon ◽  
S.J. Jung ◽  
S.-Y. Choi ◽  
...  

Although eugenol is widely used in dentistry, little is known about the molecular mechanisms responsible for its anesthetic properties. In addition to calcium channels, recently demonstrated by our group, there could be another molecular target for eugenol. Using a whole-cell patch-clamp technique, we investigated the effect of eugenol on voltage-gated sodium channel currents ( I Na) in rat dental primary afferent neurons identified by retrograde labeling with a fluorescent dye in maxillary molars. Eugenol inhibited action potentials and I Na in both capsaicin-sensitive and capsaicin-insensitive neurons. The pre-treatment with capsazepine, a competitive antagonist of transient receptor potential vanilloid 1 (TRPV1), failed to block the inhibitory effect of eugenol on I Na, suggesting no involvement of TRPV1. Two types of I Na, tetrodotoxin (TTX)-resistant and TTX-sensitive I Na, were inhibited by eugenol. Our results demonstrated that eugenol inhibits I Na in a TRPV1-independent manner. We suggest that I Na inhibition by eugenol contributes to its analgesic effect.


2019 ◽  
Vol 20 (3) ◽  
pp. 526 ◽  
Author(s):  
Mohammad Hossain ◽  
Marina Bakri ◽  
Farhana Yahya ◽  
Hiroshi Ando ◽  
Shumpei Unno ◽  
...  

Dental pain is a common health problem that negatively impacts the activities of daily living. Dentine hypersensitivity and pulpitis-associated pain are among the most common types of dental pain. Patients with these conditions feel pain upon exposure of the affected tooth to various external stimuli. However, the molecular mechanisms underlying dental pain, especially the transduction of external stimuli to electrical signals in the nerve, remain unclear. Numerous ion channels and receptors localized in the dental primary afferent neurons (DPAs) and odontoblasts have been implicated in the transduction of dental pain, and functional expression of various polymodal transient receptor potential (TRP) channels has been detected in DPAs and odontoblasts. External stimuli-induced dentinal tubular fluid movement can activate TRP channels on DPAs and odontoblasts. The odontoblasts can in turn activate the DPAs by paracrine signaling through ATP and glutamate release. In pulpitis, inflammatory mediators may sensitize the DPAs. They could also induce post-translational modifications of TRP channels, increase trafficking of these channels to nerve terminals, and increase the sensitivity of these channels to stimuli. Additionally, in caries-induced pulpitis, bacterial products can directly activate TRP channels on DPAs. In this review, we provide an overview of the TRP channels expressed in the various tooth structures, and we discuss their involvement in the development of dental pain.


2020 ◽  
Vol 21 (21) ◽  
pp. 7866
Author(s):  
Ryosuke Tsumagari ◽  
Kenta Maruo ◽  
Sho Kakizawa ◽  
Shuji Ueda ◽  
Minoru Yamanoue ◽  
...  

Diacylglycerol kinase γ (DGKγ) is a lipid kinase to convert diacylglycerol (DG) to phosphatidic acid (PA) and indirectly regulates protein kinase C γ (PKCγ) activity. We previously reported that the basal PKCγ upregulation impairs cerebellar long-term depression (LTD) in the conventional DGKγ knockout (KO) mice. However, the precise mechanism in impaired cerebellar LTD by upregulated PKCγ has not been clearly understood. Therefore, we first produced Purkinje cell-specific DGKγ KO (tm1d) mice to investigate the specific function of DGKγ in Purkinje cells and confirmed that tm1d mice showed cerebellar motor dysfunction in the rotarod and beam tests, and the basal PKCγ upregulation but not PKCα in the cerebellum of tm1d mice. Then, the LTD-induced chemical stimulation, K-glu (50 mM KCl + 100 µM, did not induce phosphorylation of PKCα and dissociation of GluR2 and glutamate receptor interacting protein (GRIP) in the acute cerebellar slices of tm1d mice. Furthermore, treatment with the PKCγ inhibitor, scutellarin, rescued cerebellar LTD, with the phosphorylation of PKCα and the dissociation of GluR2 and GRIP. In addition, nonselective transient receptor potential cation channel type 3 (TRPC3) was negatively regulated by upregulated PKCγ. These results demonstrated that DGKγ contributes to cerebellar LTD by regulation of the basal PKCγ activity.


2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Utchariya Anantamongkol ◽  
Mei Ao ◽  
Jayashree Sarathy nee Venkatasubramanian ◽  
Y. Sangeeta Devi ◽  
Nateetip Krishnamra ◽  
...  

Mammary gland ion transport is essential for lactation and is regulated by prolactin and glucocorticoids. This study delineates the roles of prolactin receptors (PRLR) and long-term prolactin and dexamethasone (P-D)-mediation of [Ca2+]i and Cl− transport in HC-11 cells. P-D (24 h) suppressed ATP-induced [Ca2+]i. This may be due to decreased Ca2+ entry since P-D decreased transient receptor potential channel 3 (TRPC3) but not secretory pathway Ca2+-ATPase 2 (SPCA2) mRNA. ATP increased Cl− transport, measured by iodide (I−) efflux, in control and P-D-treated cells. P-D enhanced I− efflux response to cAMP secretagogues without altering Cl− channels or NKCC cotransporter expression. HC-11 cells contain only the long form of PRLR (PRLR-L). Since the short isoform, PRLR-S, is mammopoietic, we determined if transfecting PRLR-S (rs) altered PRLR-L-mediated Ca2+ and Cl− transport. Untreated rs cells showed an attenuated [Ca2+]i response to ATP with no further response to P-D, in contrast to vector-transfected (vtc) controls. P-D inhibited TRPC3 in rs and vtc cells but increased SPCA2 only in rs cells. As in wild-type, cAMP-stimulated Cl− transport, in P-D-treated vtc and rs cells. In summary, 24 h P-D acts via PRLR-L to attenuate ATP-induced [Ca2+]i and increase cAMP-activated Cl− transport. PRLR-S fine-tunes these responses underscoring its mammopoietic action.


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