scholarly journals Protective Effects of Fucoxanthin on Ultraviolet B-Induced Corneal Denervation and Inflammatory Pain in a Rat Model

Marine Drugs ◽  
2019 ◽  
Vol 17 (3) ◽  
pp. 152 ◽  
Author(s):  
Shiu-Jau Chen ◽  
Ching-Ju Lee ◽  
Tzer-Bin Lin ◽  
Hsien-Yu Peng ◽  
Hsiang-Jui Liu ◽  
...  
Keyword(s):  
Inflammatory Pain ◽  
Transient Receptor Potential ◽  
Pain Treatment ◽  
Brown Seaweed ◽  
P38 Map Kinase ◽  
Ultraviolet B ◽  
Transient Receptor Potential Vanilloid ◽  
Related Factor ◽  
Protective Effects ◽  
Trigeminal Pain

Fucoxanthin is a carotenoid with many pharmaceutical properties that is found in brown seaweed. However, the effects of fucoxanthin on corneal innervation and intense eye pain have not been extensively examined. To clarify the protective roles and underlying mechanisms of fucoxanthin on ocular lesions, we investigated the beneficial effects and mechanisms by which fucoxanthin ameliorates ultraviolet B (UVB)-induced corneal denervation and trigeminal pain. Treatment with fucoxanthin enhanced the expression of nuclear factor erythroid 2-related factor 2 in the cornea. Inhibition of typical denervation and epithelial exfoliation in the cornea were observed in rats treated with fucoxanthin following UVB-induced nerve disorders. Moreover, the active phosphorylated form of p38 MAP kinase (pp38) and the number of glial fibrillary acidic protein (GFAP)-positive neural cells were significantly reduced. Decreased expression of neuron-selective transient receptor potential vanilloid type 1 (TRPV1) in the trigeminal ganglia neurons was also demonstrated in rats treated with fucoxanthin after UVB-induced keratitis. Symptoms of inflammatory pain, including difficulty in opening the eyes and eye wipe behaviour, were also reduced in fucoxanthin-treated groups. Pre-treatment with fucoxanthin may protect the eyes from denervation and inhibit trigeminal pain in UVB-induced photokeratitis models.

scholarly journals Total Sesquiterpene Glycosides from Loquat Leaves Ameliorate HFD-Induced Insulin Resistance by Modulating IRS-1/GLUT4, TRPV1, and SIRT6/Nrf2 Signaling Pathways

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Ruoyun Wu ◽  
Tunyu Jian ◽  
Xiaoqin Ding ◽  
Han Lv ◽  
Xiuhua Meng ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Signaling Pathways ◽  
Transient Receptor Potential ◽  
Glucose Transporter ◽  
Receptor Potential ◽  
Causative Factor ◽  
Eriobotrya Japonica ◽  
Transient Receptor Potential Vanilloid ◽  
Related Factor

Loquat (Eriobotrya japonica Lindl.), a subtropical fruit tree native to Asia, is not only known to be nutritive but also beneficial for the treatment of diabetes in the south of China. To expand its development, this study was undertaken concerning the potential therapeutic role of total sesquiterpene glycosides (TSGs) from loquat leaves in insulin resistance (IR), the major causative factor of type 2 diabetes mellitus (T2DM). Male C57BL/6 mice were fed on high-fat diet (HFD) to induce IR and then were given TSG by oral administration at 25 and 100 mg/kg/day, respectively. TSG notably improved metabolic parameters including body weight, serum glucose, and insulin levels and prevented hepatic injury. Moreover, inflammatory response and oxidative stress were found to be remarkably alleviated in IR mice with TSG supplement. Further research in liver of IR mice demonstrated that TSG repaired the signalings of insulin receptor substrate-1 (IRS-1)/glucose transporter member 4 (GLUT4) and AMP-activated protein kinase (AMPK), which improved glucose and lipid metabolism and prevented lipid accumulation in liver. It was also observed that TSG suppressed the expression of transient receptor potential vanilloid 1 (TRPV1), whereas the signaling pathway of sirtuin-6 (SIRT6)/nuclear factor erythroid 2-related factor 2 (Nrf2) was significantly promoted. Based on the results, the current study demonstrated that TSG from loquat leaves potentially ameliorated IR in vivo by enhancing IRS-1/GLUT4 signaling and AMPK activation and modulating TRPV1 and SIRT6/Nrf2 signaling pathways.

Roles of Cannabidiol in the treatment and prevention of Alzheimer’s disease by multi-target actions

2021 ◽  
Vol 21 ◽  
Author(s):  
Xiao- Bei Zhang ◽  
Jintao Li ◽  
Juanhua Gu ◽  
Yue-Qin Zeng
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Transient Receptor Potential ◽  
Senile Plaques ◽  
Memory Loss ◽  
Receptor Potential ◽  
Transient Receptor Potential Vanilloid ◽  
Peroxisome Proliferator ◽  
Protective Effects ◽  
Peroxisome Proliferator Activated Receptor

: Alzheimer’s disease (AD) is one of the most common neurodegenerative diseases with chronic, progressive, and irreversible characteristics, affecting nearly 50 million older adults worldwide. The pathogenesis of AD includes the formation of senile plaques, the abnormal aggregation of tau protein and the gradual degeneration and death of cerebral cortical cells. The main symptoms are memory loss, cognitive decline and behavioral disorders. Studies indicate that cannabidiol(CBD) possesses various pharmacological activities including anti-inflammatory, anti-oxidation and neuroprotective activities. It has been suggested as a potential multi-target medicine for treatment of AD. In this review, we aim to summarize the underlying mechanisms and protective effects of CBD on signaling pathways and central receptors involved in the pathogenesis of AD, including the endocannabinoid system（eCBs）, the Transient receptor potential vanilloid type 1(TRPV1) receptor, and the Peroxisome proliferator-activated receptor (PPAR) receptor.

scholarly journals TRPV1 promotes opioid analgesia during inflammation

2019 ◽  
Vol 12 (575) ◽  
pp. eaav0711 ◽  
Author(s):  
Lilian Basso ◽  
Reem Aboushousha ◽  
Churmy Yong Fan ◽  
Mircea Iftinca ◽  
Helvira Melo ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Opioid Receptor ◽  
Inflammatory Pain ◽  
Transient Receptor Potential ◽  
Nuclear Translocation ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Opioid Analgesia ◽  
Transient Receptor Potential Vanilloid ◽  
Receptor Desensitization

Pain and inflammation are inherently linked responses to injury, infection, or chronic diseases. Given that acute inflammation in humans or mice enhances the analgesic properties of opioids, there is much interest in determining the inflammatory transducers that prime opioid receptor signaling in primary afferent nociceptors. Here, we found that activation of the transient receptor potential vanilloid type 1 (TRPV1) channel stimulated a mitogen-activated protein kinase (MAPK) signaling pathway that was accompanied by the shuttling of the scaffold protein β-arrestin2 to the nucleus. The nuclear translocation of β-arrestin2 in turn prevented its recruitment to the μ-opioid receptor (MOR), the subsequent internalization of agonist-bound MOR, and the suppression of MOR activity that occurs upon receptor desensitization. Using the complete Freund’s adjuvant (CFA) inflammatory pain model to examine the role of TRPV1 in regulating endogenous opioid analgesia in mice, we found that naloxone methiodide (Nal-M), a peripherally restricted, nonselective, and competitive opioid receptor antagonist, slowed the recovery from CFA-induced hypersensitivity in wild-type, but not TRPV1-deficient, mice. Furthermore, we showed that inflammation prolonged morphine-induced antinociception in a mouse model of opioid receptor desensitization, a process that depended on TRPV1. Together, our data reveal a TRPV1-mediated signaling pathway that serves as an endogenous pain-resolution mechanism by promoting the nuclear translocation of β-arrestin2 to minimize MOR desensitization. This previously uncharacterized mechanism may underlie the peripheral opioid control of inflammatory pain. Dysregulation of the TRPV1–β-arrestin2 axis may thus contribute to the transition from acute to chronic pain.

scholarly journals N-Arachidonoyl-l-Serine is Neuroprotective after Traumatic Brain Injury by Reducing Apoptosis

2011 ◽  
Vol 31 (8) ◽  
pp. 1768-1777 ◽  
Author(s):  
Ayelet Cohen-Yeshurun ◽  
Victoria Trembovler ◽  
Alexander Alexandrovich ◽  
Erik Ryberg ◽  
Peter J Greasley ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Specific Binding ◽  
Closed Head Injury ◽  
Receptor Potential ◽  
Bk Channels ◽  
Transient Receptor Potential Vanilloid ◽  
Lesion Volume ◽  
Protective Effects ◽  
Neuroprotective Effects ◽  
Trpv1 Channels

N-arachidonoyl-L-serine (AraS) is a brain component structurally related to the endocannabinoid family. We investigated the neuroprotective effects of AraS following closed head injury induced by weight drop onto the exposed fronto-parietal skull and the mechanisms involved. A single injection of AraS following injury led to a significant improvement in functional outcome, and to reduced edema and lesion volume compared with vehicle. Specific antagonists to CB2 receptors, transient receptor potential vanilloid 1 (TRPV1) or large conductance calcium-activated potassium (BK) channels reversed these effects. Specific binding assays did not indicate binding of AraS to the GPR55 cannabinoid receptor. N-arachidonoyl-l-serine blocked the attenuation in phosphorylated extracellular-signal-regulated kinase 1/2 (ERK) levels and led to an increase in pAkt in both the ipsilateral and contralateral cortices. Increased levels of the prosurvival factor Bcl-xL were evident 24 hours after injury in AraS-treated mice, followed by a 30% reduction in caspase-3 activity, measured 3 days after injury. Treatment with a CB2 antagonist, but not with a CB1 antagonist, reversed this effect. Our results suggest that administration of AraS leads to neuroprotection via ERK and Akt phosphorylation and induction of their downstream antiapoptotic pathways. These protective effects are related mostly to indirect signaling via the CB2R and TRPV1 channels but not through CB1 or GPR55 receptors.

scholarly journals Antinociceptive Effects of Emodin on CFA-Induced Inflammatory Pain in Rats

2020 ◽  
Vol 15 (7) ◽  
pp. 1934578X2094200
Author(s):  
Wan Ni ◽  
Nianyun Wang ◽  
Shenglan Tian ◽  
Qingbang Xu
Keyword(s):  
Mrna Expression ◽  
Inflammatory Pain ◽  
Transient Receptor Potential ◽  
Interleukin 1 ◽  
Receptor Potential ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Transient Receptor Potential Vanilloid ◽  
Tnf Α ◽  
Transient Receptor

The effect of emodin on complete Freund’s adjuvant (CFA)-induced inflammatory pain in rats and its potential molecular mechanism was investigated. For this, a rat model of inflammatory pain induced by CFA was established and rats were treated with emodin by intraperitoneal injection. The pain threshold was evaluated by the von Frey, thermo hyperalgesia, and cold plate tests. The mRNA expression of transient receptor potential channel ankyrin type-1 ( Trpa1) and transient receptor potential vanilloid 1 ( Trpv1) was detected by quantitative reverse transcription polymerase chain reaction, and the level of inflammatory cytokines was determined by enzyme-linked immunosorbent assay. The mechanical and thermal pain thresholds of CFA-treated rats were significantly lower than those of the control rats, while the paw withdrawal responses in response to cold stimulation were higher than that of the control group. Emodin treatment significantly improved CFA-induced hyperalgesia. Further results showed that emodin inhibits the upregulation of Trpa1 and Trpv1 mRNA expression in the dorsal root ganglion (DRG) of rats with inflammatory pain compared with the control group. Emodin also significantly reduced the levels of tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), and interleukin 6 (IL-6) in the serum of rats with inflammatory pain. Thus, emodin may inhibit hyperalgesia induced by inflammatory stimulation by downregulating the mRNA expression of Trpa1 and Trpv1 in DRG neurons and reducing the levels of TNF-α, IL-1β, and IL-6.

scholarly journals Chemokine CCL2 prevents opioid-induced inhibition of nociceptive synaptic transmission in spinal cord dorsal horn

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Mario Heles ◽  
Petra Mrozkova ◽  
Dominika Sulcova ◽  
Pavel Adamek ◽  
Diana Spicarova ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Synaptic Transmission ◽  
Dorsal Horn ◽  
Transient Receptor Potential ◽  
Pain Treatment ◽  
Spinal Cord Dorsal Horn ◽  
Transient Receptor Potential Vanilloid ◽  
Trpv1 Receptors ◽  
Spinal Cord Dorsal

Abstract Background Opioid analgesics remain widely used for pain treatment despite the related serious side effects. Some of those, such as opioid tolerance and opioid-induced hyperalgesia may be at least partially due to modulation of opioid receptors (OR) function at nociceptive synapses in the spinal cord dorsal horn. It was suggested that increased release of different chemokines under pathological conditions may play a role in this process. The goal of this study was to investigate the crosstalk between the µOR, transient receptor potential vanilloid 1 (TRPV1) receptor and C–C motif ligand 2 (CCL2) chemokine and the involvement of spinal microglia in the modulation of opioid analgesia. Methods Patch-clamp recordings of miniature excitatory postsynaptic currents (mEPSCs) and dorsal root evoked currents (eEPSC) in spinal cord slices superficial dorsal horn neurons were used to evaluate the effect of µOR agonist [D-Ala2, N-Me-Phe4, Gly5-ol]-enkephalin (DAMGO), CCL2, TRPV1 antagonist SB366791 and minocycline. Paw withdrawal test to thermal stimuli was combined with intrathecal (i.t.) delivery of CCL2 and DAMGO to investigate the modulation in vivo. Results Application of DAMGO induced a rapid decrease of mEPSC frequency and eEPSC amplitude, followed by a delayed increase of the eESPC amplitude, which was prevented by SB366791. Chemokine CCL2 treatment significantly diminished all the DAMGO-induced changes. Minocycline treatment prevented the CCL2 effects on the DAMGO-induced eEPSC depression, while mEPSC changes were unaffected. In behavioral experiments, i.t. injection of CCL2 completely blocked DAMGO-induced thermal hypoalgesia and intraperitoneal pre-treatment with minocycline prevented the CCL2 effect. Conclusions Our results indicate that opioid-induced inhibition of the excitatory synaptic transmission could be severely attenuated by increased CCL2 levels most likely through a microglia activation-dependent mechanism. Delayed potentiation of neurotransmission after µOR activation is dependent on TRPV1 receptors activation. Targeting CCL2 and its receptors and TRPV1 receptors in combination with opioid therapy could significantly improve the analgesic properties of opioids, especially during pathological states.

scholarly journals Electroacupuncture inhibits the interaction between peripheral TRPV1 and P2X3 in rats with different pathological pain

2021 ◽  
Vol 70 (4) ◽  
pp. 635-647
Author(s):  
Yingjun Liu ◽  
Junying Du ◽  
Junfan Fang ◽  
Xuaner Xiang ◽  
Yingling Xu ◽  
...  
Keyword(s):  
Neuropathic Pain ◽  
Inflammatory Pain ◽  
Transient Receptor Potential ◽  
Subcutaneous Administration ◽  
Receptor Potential ◽  
Transient Receptor Potential Vanilloid ◽  
Spontaneous Pain ◽  
Physical Interaction ◽  
Expression Ratio ◽  
Pathological Pain

Chronic pain is regarded to be one of the common and refractory diseases to cure in the clinic. One hundred Hz electroacupuncture (EA) is commonly used for inflammatory pain and 2 Hz for neuropathic pain possibly by modulating the transient receptor potential vanilloid subtype 1 (TRPV1) or the purinergic P2X3 related pathways. To clarify the mechanism of EA under various conditions of pathological pain, rats received a subcutaneous administration of complete Freund’s adjuvant (CFA) for inflammatory pain and spared nerve injury (SNI) for neuropathic pain. The EA was performed at the bilateral ST36 and BL60 1 d after CFA or SNI being successfully established for 3 consecutive days. The mechanical hyperalgesia test was measured at baseline, 1 d after model establishment, 1 d and 3 d after EA. The co-expression changes, co-immunoprecipitation of TRPV1 and P2X3, and spontaneous pain behaviors (SPB) test were performed 3 d after EA stimulation. One hundred Hz EA or 2Hz EA stimulation could effectively down-regulate the hyperalgesia of CFA or SNI rats. The increased co-expression ratio between TRPV1 and P2X3 at the dorsal root ganglion (DRG) in two types of pain could be reduced by 100Hz or 2Hz EA intervention. While 100Hz or 2Hz EA was not able to eliminate the direct physical interaction between TRPV1 and P2X3. Moreover, EA could significantly inhibit the SPB induced by the co-activation of peripheral TRPV1 and P2X3. All results indicated that EA could significantly reduce the hyperalgesia and the SPB, which was partly related to inhibiting the co-expression and indirect interaction between peripheral TRPV1 and P2X3.

scholarly journals Resolvin D1 and D2 Inhibit Transient Receptor Potential Vanilloid 1 and Ankyrin 1 Ion Channel Activation on Sensory Neurons via Lipid Raft Modification

2020 ◽  
Vol 21 (14) ◽  
pp. 5019
Author(s):  
Maja Payrits ◽  
Ádám Horváth ◽  
Tünde Biró-Sütő ◽  
János Erostyák ◽  
Géza Makkai ◽  
...  
Keyword(s):  
Sensory Neurons ◽  
Lipid Raft ◽  
Cho Cells ◽  
Inflammatory Pain ◽  
Transient Receptor Potential ◽  
Sensory Nerve ◽  
Receptor Potential ◽  
Transient Receptor Potential Vanilloid ◽  
Resolvin D1 ◽  
Transient Receptor

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.

Glycolic acid attenuates UVB-induced aquaporin-3, matrix metalloproteinase-9 expression, and collagen degradation in keratinocytes and mouse skin

2019 ◽  
Vol 476 (10) ◽  
pp. 1387-1400 ◽  
Author(s):  
Sheau-Chung Tang ◽  
Lee-Chun Tang ◽  
Chin-Hung Liu ◽  
Pei-Yun Liao ◽  
Ji-Ching Lai ◽  
...  
Keyword(s):  
Glycolic Acid ◽  
Transient Receptor Potential ◽  
Mouse Skin ◽  
Skin Aging ◽  
Ultraviolet B ◽  
Mitogen Activated Protein Kinase ◽  
Transient Receptor Potential Vanilloid ◽  
Type I ◽  
Dorsal Skin ◽  
Aquaporin 3

Abstract Ultraviolet-B exposure causes an inflammatory response, photoaged skin, and degradation of extracellular matrix proteins including collagen and elastin. The regulation of these genes was suggested as an important mechanism to attenuate skin aging. Glycolic acid (GA) is commonly present in fruits and recently used to treat dermatological diseases. We reported that GA slows down cell inflammation and aging caused by UVB. Little is known about GA retarding the skin premature senescence or how to impede these events. To investigate the potential of GA to regulate the expression of MMPs and collagen, GA was topically applied onto human keratinocytes and the C57BL/6J mice dorsal skin. In the present study, we demonstrated that GA reduced UVB-induced type-I procollagen expression and secretory collagen levels. GA reverted and dose-dependently increased the level of aquaporin-3 (AQP3), the expression of which was down-regulated by UVB. The UV-induced MMP-9 level and activity were reduced by GA pre-treatment. Concomitantly, GA reverted mitogen-activated protein kinase (MMP-9) activation and inhibited the extracellular signal-regulated kinase activation (p38, pERK) triggered by UVB. The animal model also presented that GA attenuated the wrinkles caused by UVB on the mouse dorsal skin. Finally, GA triggers the transient receptor potential vanilloid-1 (TRPV-1) channel to initiate the anti-photoaging mechanism in keratinocytes. These findings clearly indicated that the mechanisms of GA promote skin protection against UVB-induced photoaging and wrinkle formation. GA might be an important reagent and more widely used to prevent UVB-induced skin aging.

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