Evidence Details for Trpv1
PMID Title Journal Year Abstract
31775332 Electroacupuncture Alleviates Paclitaxel-Induced Peripheral Neuropathic Pain in Rats via Suppressing TLR4 Signaling and TRPV1 Upregulation in Sensory Neurons. Int J Mol Sci. 2019 Nov 25;20(23):5917. doi: 10.3390/ijms20235917. 2019 Nov 25 Paclitaxel-induced peripheral neuropathy is a common adverse effect during paclitaxel treatment resulting in sensory abnormalities and neuropathic pain during chemotherapy and in cancer survivors. Conventional therapies are usually ineffective and possess adverse effects. Here, we examined the effects of electroacupuncture (EA) on a rat model of paclitaxel-induced neuropathic pain and related mechanisms. EA robustly and persistently alleviated paclitaxel-induced pain hypersensitivities. Mechanistically, TLR4 (Toll-Like Receptor 4) and downstream signaling MyD88 (Myeloid Differentiation Primary Response 88) and TRPV1 (Transient Receptor Potential Vallinoid 1) were upregulated in dorsal root ganglion (DRGs) of paclitaxel-treated rats, whereas EA reduced their overexpression. Ca(2+) imaging further indicated that TRPV1 channel activity was enhanced in DRG neurons of paclitaxel-treated rats whereas EA suppressed the enhanced TRPV1 channel activity. Pharmacological blocking of TRPV1 mimics the analgesic effects of EA on the pain hypersensitivities, whereas capsaicin reversed EA's effect. Spinal astrocytes and microglia were activated in paclitaxel-treated rats, whereas EA reduced the activation. These results demonstrated that EA alleviates paclitaxel-induced peripheral neuropathic pain via mechanisms possibly involving suppressing TLR4 signaling and TRPV1 upregulation in DRG neurons, which further result in reduced spinal glia activation. Our work supports EA as a potential alternative therapy for paclitaxel-induced neuropathic pain."

Evidence Sentence: Electroacupuncture Alleviates Paclitaxel-Induced Peripheral Neuropathic Pain in Rats via Suppressing TLR4 Signaling and TRPV1 Upregulation in Sensory Neurons
Evidence Sentence: Mechanistically, TLR4 (Toll-Like Receptor 4) and downstream signaling MyD88 (Myeloid Differentiation Primary Response 88) and TRPV1 (Transient Receptor Potential Vallinoid 1) were upregulated in dorsal root ganglion (DRGs) of paclitaxel-treated rats, whereas EA reduced their overexpression.
Evidence Sentence: Ca2+ imaging further indicated that TRPV1 channel activity was enhanced in DRG neurons of paclitaxel-treated rats whereas EA suppressed the enhanced TRPV1 channel activity.
Evidence Sentence: Pharmacological blocking of TRPV1 mimics the analgesic effects of EA on the pain hypersensitivities, whereas capsaicin reversed EA's effect.
Evidence Sentence: These results demonstrated that EA alleviates paclitaxel-induced peripheral neuropathic pain via mechanisms possibly involving suppressing TLR4 signaling and TRPV1 upregulation in DRG neurons, which further result in reduced spinal glia activation.
Evidence Sentence: EA Reduced the Overexpression of TLR4, MyD88, and TRPV1 in DRGs of Paclitaxel-Treated Rats
Evidence Sentence: It is well established that TRPV1 channel expression is increased in DRGs upon paclitaxel treatment and plays a critical role in mediating paclitaxel-induced peripheral neuropathic pain.
Evidence Sentence: Our immunofluorescence study revealed that the percentage of TRPV1 immune positive (TRPV1+) DRG neurons among all DRG neurons (stained with NeuN) and TRPV1 immunofluorescent staining intensity were both significantly increased in the paclitaxel-treated group (Figure 2A-C).
Evidence Sentence: Repeated EA treatment significantly reduced the overexpression of TRPV1 induced by paclitaxel treatment (Figure 2A-C).
Evidence Sentence: In contrast, sham EA had no effect on TRPV1 overexpression (Figure 2A-C).
Evidence Sentence: We further examined the expression of TRPV1 in DRGs by Western blotting.
Evidence Sentence: Western blotting revealed that TRPV1 expression was significantly increased in the L4-6 DRGs of paclitaxel-treated rats (Figure 3A).
Evidence Sentence: Repeated EA treatment significantly reduced TRPV1 overexpression in L4-6 DRGs, whereas sham EA had no effect (Figure 3A).
Evidence Sentence: Evidence suggests that TLR4 promotes TRPV1 overexpression in DRG neurons during paclitaxel-induced peripheral neuropathy and inflammation.
Evidence Sentence: TRPV1 Channel Functional Activity is Enhanced in DRG Neurons of Paclitaxel-Treated Rats, and EA Eliminated the Enhancement of TRPV1 Activity by Paclitaxel
Evidence Sentence: Since TRPV1 channel expression is upregulated in DRG neurons by paclitaxel treatment, we then performed live cell Ca2+ imaging to monitor the functional activities of TRPV1 channel in acutely dissociated L4-6 DRG neurons from paclitaxel-treated rats.
Evidence Sentence: Capsaicin, the specific TRPV1 agonist, was used to probe TRPV1 channel activities.
Evidence Sentence: Therefore, Ca2+ imaging experiments indicated that the functional activity of the TRPV1 channel was significantly increased in DRG neurons from paclitaxel-treated rats whereas repeated EA treatment attenuated the upregulated TRPV1 channel functional activity in DRG neurons induced by paclitaxel.
Evidence Sentence: Pharmacological Blocking of TRPV1 Mimics EA's Therapeutic Effect in Reducing Pain Hypersensitivities of Paclitaxel-Treated Rats
Evidence Sentence: To further confirm that EA's analgesic effect on paclitaxel-treated rats was due to TRPV1 modulation, we tested the effect of TRPV1 agonist capsaicin on EA's analgesic effect.
Evidence Sentence: These results further support the notion that EA's analgesic effect on paclitaxel-induced pain hypersensitivities is mediated by TRPV1 modulation.
Evidence Sentence: Capsaicin, the specific TRPV1 agonist, was used to probe TRPV1 channel activities.
Evidence Sentence: To further confirm that EA's analgesic effect on paclitaxel-treated rats was due to TRPV1 modulation, we tested the effect of TRPV1 agonist capsaicin on EA's analgesic effect.
Evidence Sentence: We next examined the effects of AMG9810, the specific TRPV1 antagonist, on the pain hypersensitivities of paclitaxel-treated rats.