Molecular PainPub Date : 2023-01-01DOI: 10.1177/17448069231158290
Xiaowen Liu, Ruisong Gong, Liang Peng, Jing Zhao
{"title":"Toll-like receptor 4 signaling pathway in sensory neurons mediates remifentanil-induced postoperative hyperalgesia via transient receptor potential ankyrin 1.","authors":"Xiaowen Liu, Ruisong Gong, Liang Peng, Jing Zhao","doi":"10.1177/17448069231158290","DOIUrl":"https://doi.org/10.1177/17448069231158290","url":null,"abstract":"<p><p><b>Background:</b> Remifentanil-induced postoperative hyperalgesia (RIH) refers to a state of hyperalgesia or aggravated pre-existing pain after remifentanil exposure. There has been considerable interest in understanding and preventing RIH. However, the mechanisms responsible for RIH are still not completely understood. Toll-like receptor 4 (TLR4), a classic innate immune receptor, has been detected in sensory neurons and participates in various nociceptive conditions, whereas its role in RIH remains unclear. Transient receptor potential ankyrin 1 (TRPA1) always serves as a nociceptive channel, whereas its role in RIH has not yet been investigated. This study aimed to determine whether the TLR4 signaling pathway in sensory neurons engaged in the development of RIH and the possible involvement of TRPA1 during this process. <b>Methods:</b> A rat model of remifentanil-induced postoperative hyperalgesia (RIH) was established, which presented decreased paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL). The mRNA and protein expression levels of TLR4, phosphorylated NF-κB, and TRPA1 in the dorsal root ganglion (DRG) from RIH model were analyzed by real-time PCR, western blot, and immunofluorescence. The TLR4 antagonist TAK-242 and the TRPA1 antagonist HC-030031 were applied to determine the role of sensory neuron TLR4 signaling and TRPA1 in RIH. <b>Results:</b> Compared with control, PWMT and PWTL were significantly decreased in RIH model. Moreover, the mRNA and protein expression of TLR4 and TRPA1 in DRG were upregulated after remifentanil exposure together with increased NF-κB phosphorylation. TLR4 antagonist TAK-242 mitigated mechanical pain in RIH together with downregulated expression of TLR4, phosphorylated NF-κB, and TRPA1 in DRG neurons. In addition, TRPA1 antagonist HC-030031 also alleviated mechanical pain and decreased TRPA1 expression in RIH without affecting TLR4 signaling in DRG. <b>Conclusions:</b> Taken together, these results suggested that activation of TLR4 signaling pathway engaged in the development of RIH by regulating TRPA1 in DRG neurons. Blocking TLR4 and TRPA1 might serve as a promising therapeutic strategy for RIH.</p>","PeriodicalId":19010,"journal":{"name":"Molecular Pain","volume":"19 ","pages":"17448069231158290"},"PeriodicalIF":3.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/37/7d/10.1177_17448069231158290.PMC9926008.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10734978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Molecular PainPub Date : 2023-01-01DOI: 10.1177/17448069231218352
Kai Sun, Hao Zhang, Ting Zhang, Nan Sun, Jingru Hao, Zhiping Wang, Can Gao
{"title":"Spinal HDAC6 mediates nociceptive behaviors induced by chronic constriction injury via neuronal activation and neuroinflammation.","authors":"Kai Sun, Hao Zhang, Ting Zhang, Nan Sun, Jingru Hao, Zhiping Wang, Can Gao","doi":"10.1177/17448069231218352","DOIUrl":"10.1177/17448069231218352","url":null,"abstract":"<p><p>Neuropathic pain (NP) is often accompanied by psychiatric comorbidities and currently lacks effective treatment. Prior research has shown that HDAC6 plays a crucial role in pain sensitization, but the specific mechanisms remain unclear. HDAC6 inhibitors have been found to alleviate mechanical allodynia caused by inflammation and peripheral nerve damage. In this study, we investigated the cellular mechanisms of HDAC6 in the development and maintenance of neuropathic pain. Our findings indicate that HDAC6 expression in the spinal cord (SC) is upregulated in a time-dependent manner following chronic constriction injury (CCI). HDAC6 is primarily expressed in neurons and microglia in the spinal cord. CCI-induced HDAC6 production was abolished by intrathecal injection of a microglia inhibitor. ACY-1215, a specific HDAC6 inhibitor, significantly reduced CCI-induced mechanical allodynia, but not thermal hyperalgesia. ACY-1215 also inhibited neuron activation and suppressed CCI-induced pyroptosis and neuroinflammatory responses. In summary, our results suggest that HDAC6 contributes to the development and maintenance of NP through neuronal activation and neuroinflammation. HDAC6 may be a promising target for treating NP.</p>","PeriodicalId":19010,"journal":{"name":"Molecular Pain","volume":" ","pages":"17448069231218352"},"PeriodicalIF":3.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10734332/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138047402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Molecular PainPub Date : 2023-01-01DOI: 10.1177/17448069231222407
Michael Morgan, Jenny Thai, Sara Nencini, James Xu, Jason J Ivanusic
{"title":"Stomatin-like protein 3 modulates the responses of Aδ, but not C fiber bone afferent neurons to noxious mechanical stimulation in an animal model of acute experimental bone pain.","authors":"Michael Morgan, Jenny Thai, Sara Nencini, James Xu, Jason J Ivanusic","doi":"10.1177/17448069231222407","DOIUrl":"10.1177/17448069231222407","url":null,"abstract":"<p><p>STOML3 is a membrane bound scaffolding protein that has been shown to facilitate the opening of mechanically sensitive ion channels and contribute to noxious mechanical sensation, allodynia and hyperalgesia. In this study, we aimed to determine the role of STOML3 in noxious mechanical sensitivity of bone afferent neurons and carrageenan-induced acute inflammation in the bone. An <i>in</i> <i>vivo</i><i>,</i> electrophysiological bone-nerve preparation was used to make recordings of the activity and sensitivity of bone afferent neurons that innervate the tibial marrow cavity in anaesthetised rats, in response to noxious mechanical stimuli delivered to the marrow cavity, before and after injection of either the STOML3 oligomerisation inhibitor OB-1 or vehicle, in either naïve animals or animals with carrageenan-induced inflammation of the marrow cavity. A dynamic weight-bearing apparatus was used to measure weight bearing in response to inflammatory pain before and after injection of OB-1 or saline into the tibial marrow cavity in the presence of carrageenan-induced inflammation. Electrophysiological recordings revealed that Aδ, but not C bone afferent neurons have a reduced discharge frequency in response to mechanical stimulation, and that carrageenan-induced sensitisation of Aδ, but not C bone afferent neurons was attenuated by inhibition of STOML3 oligomerisation with OB-1. Animals treated with OB-1 spent a significantly greater amount of time on the limb injected with carrageenan than animals treated with saline. Our findings demonstrate that inhibition of STOML3 oligomerisation reduces inflammatory bone pain by reducing the sensitivity of Aδ bone afferent neurons to mechanical stimulation. Targeting STOML3 may be an effective approach to reduce pain from noxious pressure and/or painful inflammatory pathology in bone.</p>","PeriodicalId":19010,"journal":{"name":"Molecular Pain","volume":"19 ","pages":"17448069231222407"},"PeriodicalIF":3.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10734363/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138799985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Involvement of interferon gamma signaling in spinal trigeminal caudal subnucleus astrocyte in orofacial neuropathic pain in rats with infraorbital nerve injury.","authors":"Sayaka Asano, Akiko Okada-Ogawa, Momoyo Kobayashi, Mamiko Yonemoto, Yasushi Hojo, Ikuko Shibuta, Noboru Noma, Koichi Iwata, Suzuro Hitomi, Masamichi Shinoda","doi":"10.1177/17448069231222403","DOIUrl":"10.1177/17448069231222403","url":null,"abstract":"<p><p><i>Background</i>: Trigeminal nerve injury causes orofacial pain that can interfere with activities of daily life. However, the underlying mechanism remains unknown, and the appropriate treatment has not been established yet. This study aimed to examine the involvement of interferon gamma (IFN-γ) signaling in the spinal trigeminal caudal subnucleus (Vc) in orofacial neuropathic pain. <i>Methods</i>: Infraorbital nerve (ION) injury (IONI) was performed in rats by partial ION ligation. The head-withdrawal reflex threshold (HWT) to mechanical stimulation of the whisker pad skin was measured in IONI or sham rats, as well as following a continuous intracisterna magna administration of IFN-γ and a mixture of IFN-γ and fluorocitrate (inhibitor of astrocytes activation) in naïve rats, or an IFN-γ antagonist in IONI rats. The IFN-γ receptor immunohistochemistry and IFN-γ Western blotting were analyzed in the Vc after IONI or sham treatment. The glial fibrillary acid protein (GFAP) immunohistochemistry and Western blotting were also analyzed after administration of IFN-γ and the mixture of IFN-γ and fluorocitrate. Moreover, the change in single neuronal activity in the Vc was examined in the IONI, sham, and IONI group administered IFN-γ antagonist. <i>Results</i>: The HWT decreased after IONI. The IFN-γ and IFN-γ receptor were upregulated after IONI, and the IFN-γ receptor was expressed in Vc astrocytes. IFN-γ administration decreased the HWT, whereas the mixture of IFN-γ and fluorocitrate recovered the decrement of HWT. IFN-γ administration upregulated GFAP expression, while the mixture of IFN-γ and fluorocitrate recovered the upregulation of GFAP expression. IONI significantly enhanced the neuronal activity of the mechanical-evoked responses, and administration of an IFN-γ antagonist significantly inhibited these enhancements. <i>Conclusions</i>: IFN-γ signaling through the receptor in astrocytes is a key mechanism underlying orofacial neuropathic pain associated with trigeminal nerve injury. These findings will aid in the development of therapeutics for orofacial neuropathic pain.</p>","PeriodicalId":19010,"journal":{"name":"Molecular Pain","volume":" ","pages":"17448069231222403"},"PeriodicalIF":3.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138800008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Molecular PainPub Date : 2023-01-01DOI: 10.1177/17448069231179011
Min Zhuo
{"title":"Silent synapses in pain-related anterior cingulate cortex.","authors":"Min Zhuo","doi":"10.1177/17448069231179011","DOIUrl":"https://doi.org/10.1177/17448069231179011","url":null,"abstract":"<p><p>Synaptic plasticity such as Long-term potentiation (LTP) is a key mechanism for learning in central synapses including the cortex. There are two least two major forms of LTPs: presynaptic LTP and postsynaptic LTP. For postsynaptic LTP, the potentiation of AMPA receptor-mediated responses through protein phosphorylation is thought to be a key mechanism. Silent synapses have been reported in the hippocampus, but it is thought to be mainly present in the cortex during early development, and may contribute to maturation of the cortical circuit. However, recent several lines of evidence demonstrate that silent synapses may exist in mature synapses of adult cortex, and they can be recruited by LTP-inducing protocols, as well as chemical-induced LTP. In pain-related cortical regions, silent synapses may not only contribute to cortical excitation after peripheral injury, but also the recruitment of new cortical circuits as well. Thus, it is proposed that silent synapses and modification of functional AMPA receptors and NMDA receptors may play important roles in chronic pain, including phantom pain.</p>","PeriodicalId":19010,"journal":{"name":"Molecular Pain","volume":"19 ","pages":"17448069231179011"},"PeriodicalIF":3.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10226042/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9543395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Molecular PainPub Date : 2023-01-01DOI: 10.1177/17448069231158287
RafaÅ Staszkiewcz, Marcin Gralewski, Dorian gÅ Adysz, Kamil bryÅ, Tomasz Francuz, Wojciech Garczorz, michaÅ Garczarek, Marcin Gadzielinski, wiesÅ Aw Marcol, Dawid sobaÅ Ski, Beniamin Oskar Grabarek
{"title":"Evaluation of the concentration of growth associated protein-43 and glial cell-derived neurotrophic factor in degenerated intervertebral discs of the lumbosacral region of the spine.","authors":"RafaÅ Staszkiewcz, Marcin Gralewski, Dorian gÅ Adysz, Kamil bryÅ, Tomasz Francuz, Wojciech Garczorz, michaÅ Garczarek, Marcin Gadzielinski, wiesÅ Aw Marcol, Dawid sobaÅ Ski, Beniamin Oskar Grabarek","doi":"10.1177/17448069231158287","DOIUrl":"https://doi.org/10.1177/17448069231158287","url":null,"abstract":"<p><p>Important neurotrophic factors that are potentially involved in degenerative intervertebral disc (IVD) disease of the spine's lumbosacral (L/S) region include glial cell-derived neurotrophic factor (GDNF) and growth associated protein 43 (GAP-43). The aim of this study was to determine and compare the concentrations of GAP-43 and GDNF in degenerated and healthy IVDs and to quantify and compare the GAP-43-positive and GDNF-positive nerve fibers. The study group consisted of 113 Caucasian patients with symptomatic lumbosacral discopathy (confirmed by a specialist surgeon), an indication for surgical treatment. The control group included 81 people who underwent postmortem examination. GAP-43 and GDNF concentrations were significantly higher in IVD samples from the study group compared with the control group, and the highest concentrations were observed in the degenerated IVDs that were graded 4 on the Pfirrmann scale. In the case of GAP-43, it was found that as the degree of IVD degeneration increased, the number of GAP-43-positive nerve fibers decreased. In the case of GDNF, the greatest number of fibers per mm<sup>2</sup> of surface area was found in the IVD samples graded 3 on the Pfirrmann scale, and the number was found to be lower in samples graded 4 and 5. Hence, GAP-43 and GDNF are promising targets for analgesic treatment of degenerative IVD disease of the lumbosacral region of the spine.</p>","PeriodicalId":19010,"journal":{"name":"Molecular Pain","volume":"19 ","pages":"17448069231158287"},"PeriodicalIF":3.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/d3/e1/10.1177_17448069231158287.PMC10071099.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9636382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Activation of neurons and satellite glial cells in the DRG produces morphine-induced hyperalgesia.","authors":"Shunsuke Yamakita, Daisuke Fujita, Kazuki Sudo, Daiki Ishikawa, Kohsuke Kushimoto, Yasuhiko Horii, Fumimasa Amaya","doi":"10.1177/17448069231181973","DOIUrl":"10.1177/17448069231181973","url":null,"abstract":"<p><p>Activation of neurons and glial cells in the dorsal root ganglion is one of the key mechanisms for the development of hyperalgesia. The aim of the present study was to examine the role of neuroglial activity in the development of opioid-induced hyperalgesia. Male rats were treated with morphine daily for 3 days. The resultant phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 in the dorsal root ganglion was analyzed by immunohistochemistry and Western blotting. Pain hypersensitivity was analyzed using behavioral studies. The amount of cytokine expression in the dorsal root ganglion was also analyzed. Repeated morphine treatment induced hyperalgesia and marked induction of phosphorylated ERK1/2 in the neurons and satellite glial cells on day 3. An opioid receptor antagonist, toll like receptor-4 inhibitor, MAP/ERK kinase (MEK) inhibitor and gap junction inhibitor inhibited morphine-induced hyperalgesia and ERK1/2 phosphorylation. Morphine treatment induced alteration of cytokine expression, which was inhibited by the opioid receptor antagonist, toll like receptor-4 inhibitor, MEK inhibitor and gap junction inhibitor. Dexamethasone inhibited morphine-induced hyperalgesia and ERK1/2 phosphorylation after morphine treatment. The peripherally restricted opioid receptor antagonist, methylnaltrexone, inhibited hyperalgesia and ERK1/2 phosphorylation. Morphine activates ERK1/2 in neurons and satellite glial cells in the dorsal root ganglion via the opioid receptor and toll like receptor-4. ERK1/2 phosphorylation is gap junction-dependent and is associated with the alteration of cytokine expression. Inhibition of neuroinflammation by activation of neurons and glia might be a promising target to prevent opioid-induced hyperalgesia.</p>","PeriodicalId":19010,"journal":{"name":"Molecular Pain","volume":" ","pages":"17448069231181973"},"PeriodicalIF":2.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/17/4c/10.1177_17448069231181973.PMC10291868.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9698902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Molecular PainPub Date : 2023-01-01DOI: 10.1177/17448069231183902
Fredrik H G Ahlstrà M, Hanna Viisanen, Leena Karhinen, Kert Mã Tlik, Kim J Blomqvist, Tuomas Lilius, Yulia A Sidorova, Vinko Palada, Pekka Rauhala, Eija Kalso
{"title":"The effects of chronic high-dose morphine on microgliosis and the microglial transcriptome in rat spinal cord.","authors":"Fredrik H G Ahlstrà M, Hanna Viisanen, Leena Karhinen, Kert Mã Tlik, Kim J Blomqvist, Tuomas Lilius, Yulia A Sidorova, Vinko Palada, Pekka Rauhala, Eija Kalso","doi":"10.1177/17448069231183902","DOIUrl":"https://doi.org/10.1177/17448069231183902","url":null,"abstract":"<p><p><b>Background:</b> Opioids are efficacious and safe analgesic drugs in short-term use for acute pain but chronic use can lead to tolerance and dependence. Opioid-induced microglial activation may contribute to the development of tolerance and this process may differ between males and females. A link is suggested between this microglial activation and inflammation, disturbances of circadian rhythms, and neurotoxic effects. We set out to further delineate the effects of chronic morphine on pain behaviour, microglial and neuronal staining, and the transcriptome of spinal microglia, to better understand the role of microglia in the consequences of long-term high-dose opioid administration. <b>Experimental Approach:</b> In two experiments, we administered increasing subcutaneous doses of morphine hydrochloride or saline to male and female rats. Thermal nociception was assessed with the tail flick and hot plate tests. In Experiment I, spinal cord (SC) samples were prepared for immunohistochemical staining for microglial and neuronal markers. In Experiment II, the transcriptome of microglia from the lumbar SC was analysed. <b>Key Results:</b> Female and male rats had similar antinociceptive responses to morphine and developed similar antinociceptive tolerance to thermal stimuli following chronic increasing high doses of s.c. morphine. The area of microglial IBA1-staining in SC decreased after 2 weeks of morphine administration in both sexes. Following morphine treatment, the differentially expressed genes identified in the microglial transcriptome included ones related to the circadian rhythm<i>,</i> apoptosis, and immune system processes. <b>Conclusions:</b> Female and male rats showed similar pain behaviour following chronic high doses of morphine. This was associated with decreased staining of spinal microglia, suggesting either decreased activation or apoptosis. High-dose morphine administration also associated with several changes in gene expression in SC microglia, e.g., those related to the circadian rhythm (<i>Per2, Per3, Dbp</i>). These changes should be considered in the clinical consequences of long-term high-dose administration of opioids.</p>","PeriodicalId":19010,"journal":{"name":"Molecular Pain","volume":"19 ","pages":"17448069231183902"},"PeriodicalIF":3.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10331785/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9825977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The rs216009 single-nucleotide polymorphism of the <i>CACNA1C</i> gene is associated with phantom tooth pain.","authors":"Masako Morii, Seii Ohka, Daisuke Nishizawa, Junko Hasegawa, Kyoko Nakayama, Yuko Ebata, Moe Soeda, Ken-Ichi Fukuda, Kaori Yoshida, Kyotaro Koshika, Tatsuya Ichinohe, Kazutaka Ikeda","doi":"10.1177/17448069231193383","DOIUrl":"10.1177/17448069231193383","url":null,"abstract":"<p><p>Phantom tooth pain (PTP) is a rare and specific neuropathic pain that occurs after pulpectomy and tooth extraction, but its cause is not understood. We hypothesized that there is a genetic contribution to PTP. The present study focused on the <i>CACNA1C</i> gene, which encodes the α1C subunit of the Ca<sub>v</sub>1.2 L-type Ca<sup>2+</sup> channel (LTCC) that has been reported to be associated with neuropathic pain in previous studies. We investigated genetic polymorphisms that contribute to PTP. We statistically examined the association between genetic polymorphisms and PTP vulnerability in 33 patients with PTP and 118 patients without PTP but with pain or dysesthesia in the orofacial region. From within and around the <i>CACNA1C</i> gene, 155 polymorphisms were selected and analyzed for associations with clinical data. We found that the rs216009 single-nucleotide polymorphism (SNP) of the <i>CACNA1C</i> gene in the recessive model was significantly associated with the vulnerability to PTP. Homozygote carriers of the minor C allele of rs216009 had a higher rate of PTP. Nociceptive transmission in neuropathic pain has been reported to involve Ca<sup>2+</sup> influx from LTCCs, and the rs216009 polymorphism may be involved in <i>CACNA1C</i> expression, which regulates intracellular Ca<sup>2+</sup> levels, leading to the vulnerability to PTP. Furthermore, psychological factors may lead to the development of PTP by modulating the descending pain inhibitory system. Altogether, homozygous C-allele carriers of the rs216009 SNP were more likely to be vulnerable to PTP, possibly through the regulation of intracellular Ca<sup>2+</sup> levels and affective pain systems, such as those that mediate fear memory recall.</p>","PeriodicalId":19010,"journal":{"name":"Molecular Pain","volume":"19 ","pages":"17448069231193383"},"PeriodicalIF":3.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/5c/15/10.1177_17448069231193383.PMC10437699.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10102057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}