scholarly journals 17β-Estradiol Exacerbated Experimental Occlusal Interference-Induced Chronic Masseter Hyperalgesia by Increasing the Neuronal Excitability and TRPV1 Function of Trigeminal Ganglion in Ovariectomized Rats

2021 ◽  
Vol 22 (13) ◽  
pp. 6945
Author(s):  
Yun Liu ◽  
Xiao-Xiang Xu ◽  
Ye Cao ◽  
Si-Yi Mo ◽  
Shan-Shan Bai ◽  
...  

Pain symptoms in temporomandibular disorders (TMD) predominantly affect reproductive women, suggesting that estrogen regulates pain perception. However, how estrogen contributes to chronic TMD pain remains largely unclear. In the present study, we performed behavioral tests, electrophysiology, Western blot and immunofluorescence to investigate the role and underlying mechanisms of estrogen in dental experimental occlusal interference (EOI)-induced chronic masseter mechanical hyperalgesia in rats. We found that long-term 17β-estradiol (E2) replacement exacerbated EOI-induced masseter hyperalgesia in a dose-dependent manner in ovariectomized (OVX) rats. Whole-cell patch-clamp recordings demonstrated that E2 (100 nM) treatment enhanced the excitability of isolated trigeminal ganglion (TG) neurons in OVX and OVX EOI rats, and EOI increased the functional expression of transient receptor potential vanilloid-1 (TRPV1). In addition, E2 replacement upregulated the protein expression of TRPV1 in EOI-treated OVX rats. Importantly, intraganglionic administration of the TRPV1 antagonist AMG-9810 strongly attenuated the facilitatory effect of E2 on EOI-induced masseter mechanical sensitivity. These results demonstrate that E2 exacerbated EOI-induced chronic masseter mechanical hyperalgesia by increasing TG neuronal excitability and TRPV1 function. Our study helps to elucidate the E2 actions in chronic myogenic TMD pain and may provide new therapeutic targets for relieving estrogen-sensitive pain.

Biomolecules ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1513
Author(s):  
Sung-Min Hwang ◽  
Kihwan Lee ◽  
Sang-Taek Im ◽  
Eun Jin Go ◽  
Yong Ho Kim ◽  
...  

Local anesthetics (LAs) can completely block nociception by inhibiting voltage-gated sodium channels (VGSCs), and thus, blocking action potentials (APs) within sensory neurons. As one of the several LAs, eugenol is used for dental pain treatment. It reportedly features multiple functions in regulating diverse ion channels. This study aimed to investigate the long-lasting analgesic effect of eugenol alone, as well as that of the combination of eugenol as a noxious-heat-sensitive transient receptor potential vanilloid 1 (TRPV1) channel agonist and a permanently charged sodium channel blocker (QX-314), on neuronal excitability in trigeminal ganglion (TG) neurons. Eugenol alone increased inward current in a dose-dependent manner in capsaicin-sensitive TG neurons. Eugenol also inhibited the VGSC current and AP. These effects were reversed through wash-out. The combination of eugenol and QX-314 was evaluated in the same manner. The combination completely inhibited the VGSC current and AP. However, these effects were not reversed and were continuously blocked even after wash-out. Taken together, our results suggest that, in contrast to the effect of eugenol alone, the combination of eugenol and QX-314 irreversibly and selectively blocked VGSCs in TG neurons expressing TRPV1.


2003 ◽  
Vol 89 (3) ◽  
pp. 1387-1401 ◽  
Author(s):  
L. Liu ◽  
S. A. Simon

When capsaicin, the pungent compound in hot pepper, is applied to epithelia it produces pain, allodynia, and hyperalgesia. We investigated, using whole cell path clamp, whether some of these responses induced by capsaicin could be a consequence of capsaicin blocking I Acurrents, a reduction in which, such as occurs in injury, increases neuronal excitability. In capsaicin-sensitive (CS) rat trigeminal ganglion (TG) neurons, capsaicin inhibited I A currents in a dose-dependent manner. I A currents were reduced 49% by 1 μM capsaicin. In capsaicin-insensitive (CIS) rat TG neurons, or small-diameter mouse VR1−/− neurons, 1 μM capsaicin inhibited I A currents 9 and 3%, respectively. These data suggest that in CS neurons the vast majority of the capsaicin-induced inhibition of I Acurrents occurs as a consequence of the activation of vanilloid receptors. Capsaicin (1 μM) did not alter the I A conductance-voltage relationship but shifted the inactivation-voltage curve about 15 mV to hyperpolarizing voltages, thereby increasing the number of inactivated I A channels at the resting potential. I A currents were relatively unaffected by 1 mM CTP-cAMP or 500 nM phorbol-12, 13-dibuterate (a protein kinase C agonist) but were inhibited by 20–30% with either 1 mM CTP-cGMP or 25 μM N-(6-aminohexyl)-5-chloro-1-napthalenesulfonamide HCl (a calcium-calmodulin kinase inhibitor). In the presence of 0.5 μM KT5823, an inhibitor of protein kinase G (PKG) pathways, 1 μM capsaicin inhibited I A by only 26%. In summary, in CS neurons, capsaicin decreases I A currents through the activation of vanilloid receptors. That activation, partially through the activation of cGMP-PKG and calmodulin-dependent pathways should result in increased excitability of capsaicin-sensitive nociceptors.


Cosmetics ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 47
Author(s):  
Hwa Sun Ryu ◽  
Jeong-Yeon Choi ◽  
Kyeong-Sun Lee ◽  
Jung-No Lee ◽  
Chun Mong Lee ◽  
...  

Heat shock treatment-induced skin aging causes a thickened epidermis, increased matrix metalloproteinase (MMP)-1 expression, collagen degradation, and deep wrinkles. In this study, we investigated the effect of manassantin B in preventing heat shock treatment-induced aging. We first separated manassantin B (MB) from the roots of Saururus chinensis, and the structure was identified using 1H- and 13C-NMR spectroscopy. RT-PCR and western blotting were applied to investigate the anti-aging effect of manassantin B. Manassantin B decreased MMP-1 expression through transient receptor potential vanilloid (TRPV) 1 channel inhibition and significantly increased procollagen expression. In addition, manassantin B suppressed MAPK phosphorylation in a dose-dependent manner. Our results suggest that manassantin B, the active ingredient in S. chinensis, can be effectively used to inhibit heat shock treatment-induced skin aging.


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 295 (29) ◽  
pp. 9986-9997
Author(s):  
Nicholas W. Zaccor ◽  
Charlotte J. Sumner ◽  
Solomon H. Snyder

G-protein–coupled receptors (GPCRs) are a ubiquitously expressed family of receptor proteins that regulate many physiological functions and other proteins. They act through two dissociable signaling pathways: the exchange of GDP to GTP by linked G-proteins and the recruitment of β-arrestins. GPCRs modulate several members of the transient receptor potential (TRP) channel family of nonselective cation channels. How TRP channels reciprocally regulate GPCR signaling is less well-explored. Here, using an array of biochemical approaches, including immunoprecipitation and fluorescence, calcium imaging, phosphate radiolabeling, and a β-arrestin–dependent luciferase assay, we characterize a GPCR–TRP channel pair, angiotensin II receptor type 1 (AT1R), and transient receptor potential vanilloid 4 (TRPV4), in primary murine choroid plexus epithelial cells and immortalized cell lines. We found that AT1R and TRPV4 are binding partners and that activation of AT1R by angiotensin II (ANGII) elicits β-arrestin–dependent inhibition and internalization of TRPV4. Activating TRPV4 with endogenous and synthetic agonists inhibited angiotensin II–mediated G-protein–associated second messenger accumulation, AT1R receptor phosphorylation, and β-arrestin recruitment. We also noted that TRPV4 inhibits AT1R phosphorylation by activating the calcium-activated phosphatase calcineurin in a Ca2+/calmodulin–dependent manner, preventing β-arrestin recruitment and receptor internalization. These findings suggest that when TRP channels and GPCRs are co-expressed in the same tissues, many of these channels can inhibit GPCR desensitization.


2017 ◽  
Vol 312 (5) ◽  
pp. C562-C572 ◽  
Author(s):  
Shweta Sharma ◽  
Rishov Goswami ◽  
Michael Merth ◽  
Jonathan Cohen ◽  
Kai Y. Lei ◽  
...  

Scleroderma is a multisystem fibroproliferative disease with no effective medical treatment. Myofibroblasts are critical to the fibrogenic tissue repair process in the skin and many internal organs. Emerging data support a role for both matrix stiffness, and transforming growth factor β1 (TGFβ1), in myofibroblast differentiation. Transient receptor potential vanilloid 4 (TRPV4) is a mechanosensitive ion channel activated by both mechanical and biochemical stimuli. The objective of this study was to determine the role of TRPV4 in TGFβ1- and matrix stiffness-induced differentiation of dermal fibroblasts. We found that TRPV4 channels are expressed and functional in both human (HDF) and mouse (MDF) dermal fibroblasts. TRPV4 activity (agonist-induced Ca2+ influx) was induced by both matrix stiffness and TGFβ1 in dermal fibroblasts. TGFβ1 induced expression of TRPV4 proteins in a dose-dependent manner. Genetic ablation or pharmacological antagonism of TRPV4 channel abrogated Ca2+ influx and both TGFβ1-induced and matrix stiffness-induced myofibroblast differentiation as assessed by 1) α-smooth muscle actin expression/incorporation into stress fibers, 2) generation of polymerized actin, and 3) expression of collagen-1. We found that TRPV4 inhibition abrogated TGFβ1-induced activation of AKT but not of Smad2/3, suggesting that the mechanism by which profibrotic TGFβ1 signaling in dermal fibroblasts is modified by TRPV4 may be through non-Smad pathways. Altogether, these data identify a novel reciprocal functional link between TRPV4 activation and TGFβ1 signals regulating dermal myofibroblast differentiation. These findings suggest that therapeutic inhibition of TRPV4 activity may provide a targeted approach to the treatment of scleroderma.


Endocrinology ◽  
2005 ◽  
Vol 146 (6) ◽  
pp. 2760-2765 ◽  
Author(s):  
Istvan Merchenthaler ◽  
Gloria E. Hoffman ◽  
Malcolm V. Lane

Abstract Among the many factors that integrate the activity of the GnRH neuronal system, estrogens play the most important role. In females, estrogen, in addition to the negative feedback, also exhibits a positive feedback influence upon the activity and output of GnRH neurons to generate the preovulatory LH surge and ovulation. Until recently, the belief has been that the GnRH neurons do not contain estrogen receptors (ERs) and that the action of estrogen upon GnRH neurons is indirect involving several, estrogen-sensitive neurotransmitter and neuromodulator systems that trans-synaptically regulate the activity of the GnRH neurons. Based on our recent findings that GnRH neurons of the female rat coexpress galanin, that galanin is a potent GnRH-releasing peptide, and that ERβ is present in GnRH neurons, we have evaluated the effect of 17β-estradiol and two ERβ-selective agonists (WAY-200070, WAY-166818) on the expression of galanin within GnRH neurons. By combining immunocytochemistry for GnRH and in situ hybridization histochemistry for galanin, we demonstrate that 17β-estradiol (20 μg/kg, sc) stimulates galanin expression within GnRH-immunoreactive neurons in a time-dependent manner. A significant increase was observed 2 h after its administration to ovariectomized rats. However, a more robust expression required 3-d treatment regimen. Treatment with the β-selective ligands resulted in similar observations, although no statistical analysis is available for the 2 hr survival. These observations strongly suggest that estrogen and the ERβ-selective ligands stimulate galanin expression within GnRH neurons via ERβ, although an indirect mechanism via interneurons still cannot be ruled out.


2021 ◽  
Vol 11 ◽  
Author(s):  
Liping Zhou ◽  
Ka-Ying Wong ◽  
Wenxuan Yu ◽  
Christina Chui-Wa Poon ◽  
Huihui Xiao ◽  
...  

Herbaepimedii (HEP), a kidney-tonifying herb, has been commonly used alone or in formula for strengthening kidney function and treating bone disorders. Its bone protective activity has been demonstrated to be via estrogen receptor (ERs). HEP activates the phosphorylation of ERα in an estrogen response element- (ERE-) dependent manner. We examined the bone protective effects of HEP and its potential interactions with Selective Estrogen Receptor Modulators (SERMs, such as tamoxifen and raloxifene) as they act via the same ERs. Six-month-old mature Sprague Dawley sham-operated (Sham) or ovariectomized (OVX) rats were treated with either vehicle, 17ß-estradiol (1.0 mg/kg.day), tamoxifen (Tamo, 1.0 mg/kg.day), raloxifene (Ralo, 3.0 mg/kg.day), HEP (0.16 g/kg.day), or its combinations with respective SERMs (HEP + Tamo; HEP + Ralo) for 12 weeks. HEP and SERMs as well as their combinations significantly restored changes in bone mineral density (BMD), trabecular bone properties, and bone turnover biomarkers induced by ovarian sex hormone deficiency in ovariectomized rats. Besides the increase in serum estradiol, inhibition on follicle stimulating hormone (FSH) might also be involved in the osteoprotective activities of HEP and SERMs. HEP interacted with SERMs to protect bones from ovarian sex hormone deficiency without altering SERMs’ bone protective activities. HEP neither induced changes in uterus weight nor altered the uterotrophic activity of SERMs in OVX rats. In human osteosarcoma MG-63 cells, HEP-treated serum (HEP-Ts) significantly promoted alkaline phosphatase (ALP) activity like the crude HEP extract did but did not stimulate ERE activity. Our study also reported that biologically activated HEP interacted with SERMs to promote ALP activity without altering the action of SERMs at most of the concentrations tested in MG-63 cells. HEP exerted bone protective activity and the use of HEP did not alter the bone protective activities of SERMs when they were used simultaneously in an estrogen-deficient rat model.


2019 ◽  
Author(s):  
Wen-yuan Zhang ◽  
Yujin Guo ◽  
Ke-yi Wang ◽  
Pei Jiang

Abstract Background: A deficiency of vitamin D (VD) or 17β-estradiol (E2) is associated with increased risk of mood disorders such as depression in menopausal females, but the mechanism underlying is still elusive. The present study aims to evaluate whether vitamin D and 17β-estradiol could relieve a depressive-like state through neuroinflammatory regulation in ovariectomized (OVX) rats. Methods: Female SD rats were randomly divided into four groups, namely, control (SHAM), OVX, OVX+VD, and OVX+E2. The treatment procedure was performed for 10 weeks until sacrifice. Results: The chronic administration of vitamin D and 17β-estradiol showed anti-depressive-like activity in the OVX rats. Additionally, vitamin D and 17β-estradiol upregulated each other's receptors, including VDR, ERα, and ERβ in the hippocampus of OVX rats. Vitamin D and 17β-estradiol showed neuroprotective effects by decreasing OVX-induced apoptosis and neuronal damage, regulating the AMPK/NF-κB signaling pathway, and reducing the proinflammatory cytokines (IL-1β, IL-6, and TNFα), as well as iNOS and COX-2 in the hippocampus of OVX rats. Conclusions: The present study demonstrated that vitamin D and 17β-estradiol could upregulate each other's receptors and regulate the AMPK/NF-κB pathway to relieve the OVX-induced depressive-like state. The results should stimulate translational research towards the vitamin D potential for prevention or treatment of menopause-related depression.


2019 ◽  
Vol 116 (18) ◽  
pp. 8869-8878 ◽  
Author(s):  
Shangyu Dang ◽  
Mark K. van Goor ◽  
Daniel Asarnow ◽  
YongQiang Wang ◽  
David Julius ◽  
...  

TRPV5 (transient receptor potential vanilloid 5) is a unique calcium-selective TRP channel essential for calcium homeostasis. Unlike other TRPV channels, TRPV5 and its close homolog, TRPV6, do not exhibit thermosensitivity or ligand-dependent activation but are constitutively open at physiological membrane potentials and modulated by calmodulin (CaM) in a calcium-dependent manner. Here we report high-resolution electron cryomicroscopy structures of truncated and full-length TRPV5 in lipid nanodiscs, as well as of a TRPV5 W583A mutant and TRPV5 in complex with CaM. These structures highlight the mechanism of calcium regulation and reveal a flexible stoichiometry of CaM binding to TRPV5.


Sign in / Sign up

Export Citation Format

Share Document