Molecular PainPub Date : 2023-01-01DOI: 10.1177/17448069231186592
Justin E LaVigne, Ian M Adams, Marena A Montera, Karin N Westlund, Sascha Ra Alles
{"title":"Pain-related behavioral and electrophysiological actions of dynorphin A (1-17).","authors":"Justin E LaVigne, Ian M Adams, Marena A Montera, Karin N Westlund, Sascha Ra Alles","doi":"10.1177/17448069231186592","DOIUrl":"https://doi.org/10.1177/17448069231186592","url":null,"abstract":"<p><p>Dynorphin A (1-17) (DynA17) has been identified as a key regulator of both sensory and affective dimensions of chronic pain. Following nerve injury, increases in DynA17 have been reported in the spinal and supraspinal areas involved in chronic pain. Blocking these increases provides therapeutic benefits in preclinical chronic pain models. Although heavily characterized at the behavioral level, how DynA17 mediates its effects at the cellular physiological level has not been investigated. In this report, we begin to decipher how DynA17 mediates its direct effects on mouse dorsal root ganglion (DRG) cells and how intrathecal administration modifies a key node in the pain axis, the periaqueductal gray These findings build on the plethora of literature defining DynA17 as a critical neuropeptide in the pathophysiology of chronic pain syndromes.</p>","PeriodicalId":19010,"journal":{"name":"Molecular Pain","volume":"19 ","pages":"17448069231186592"},"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/0d/fb/10.1177_17448069231186592.PMC10328155.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9763144","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: 10.1177/17448069221148958
Ryan Vaden, Jianguo Gu
{"title":"Non-nociceptive and nociceptive-like trigeminal Aβ-afferent neurons of rats: Distinct electrophysiological properties, mechanical and chemical sensitivity.","authors":"Ryan Vaden, Jianguo Gu","doi":"10.1177/17448069221148958","DOIUrl":"https://doi.org/10.1177/17448069221148958","url":null,"abstract":"<p><p>The role of Aβ-afferents in somatosensory function is often oversimplified as low threshold mechanoreceptors (LTMRs) with large omission of Aβ-afferent involvement in nociception. Recently, we have characterized Aβ-afferent neurons which have large diameter somas in the trigeminal ganglion (TG) and classified them into non-nociceptive and nociceptive-like TG afferent neurons based on their electrophysiological properties. Here, we extend our previous observations to further characterize electrophysiological properties of trigeminal Aβ-afferent neurons and investigate their mechanical and chemical sensitivity by patch-clamp recordings from large-diameter TG neurons in ex vivo TG preparations of adult male and female rats. Based on cluster analysis of electrophysiological properties, trigeminal Aβ-afferent neurons can be classified into five discrete types (type I, IIa, IIb, IIIa, and IIIb), which responded differentially to mechanical stimulation and sensory mediators including serotonin (5-HT), acetylcholine (ACh) and adenosine triphosphate (ATP). Notably, type I neuron action potential (AP) was small in amplitude, width was narrow in duration, and peak dV/dt repolarization was great with no deflection observed, whereas discretely graded differences were observed for type IIa, IIb, IIIa, and IIIb, as AP increased in amplitude, width broadened in duration, and peak dV/dt repolarization reduced with the emergence of increasing deflection. Type I, IIa, and IIb neurons were mostly mechanically sensitive, displaying robust and rapidly adapting mechanically activated current (I<sub>MA</sub>) in response to membrane displacement, while IIIa and IIIb, conversely, were almost all mechanically insensitive. Interestingly, mechanical insensitivity coincided with increased sensitivity to 5-HT and ACh. Together, type I, IIa and IIb display features of LTMR Aβ-afferent neurons while type IIIa and type IIIb show properties of nociceptive Aβ-afferent neurons.</p>","PeriodicalId":19010,"journal":{"name":"Molecular Pain","volume":"19 ","pages":"17448069221148958"},"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/0b/e2/10.1177_17448069221148958.PMC9829874.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9953015","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: 10.1177/17448069231187366
Sotatsu Tonomura, Jianguo Gu
{"title":"Saltatory conduction and intrinsic electrophysiological properties at the nodes of ranvier of Aα/β-afferent fibers and Aα-efferent fibers in rat sciatic nerves.","authors":"Sotatsu Tonomura, Jianguo Gu","doi":"10.1177/17448069231187366","DOIUrl":"10.1177/17448069231187366","url":null,"abstract":"<p><p>Large-diameter myelinated fibers in sciatic nerves are composed of both Aα/β-afferent fibers and Aα-efferent fibers to convey sensory and motor impulses, respectively, via saltatory conduction for rapid leg responses. Saltatory conduction and electrophysiological properties at the nodes of Ranvier (NRs) of these sciatic nerve fibers have not been directly studied. We used ex vivo sciatic nerve preparations from rats and applied patch-clamp recordings at the NRs of both Aα/β-afferent fibers and Aα-efferent fibers in the sciatic nerves to characterize their saltatory conduction and intrinsic electrophysiological properties. The velocity and frequency of saltatory conduction in both types of fibers were similar. Resting membrane potentials (RMPs), input resistance, action potential (AP) threshold, and AP rheobase were also not significantly different at the NRs of the two types of fibers in the sciatic nerves. In comparison with Aα/β-afferent fibers, Aα-efferent fibers in the sciatic nerves show higher amplitude and broader width of APs at their NRs. At the NRs of both types of fibers, depolarizing voltages evoked transient inward currents followed by non-inactivating outward currents, and the inward currents and non-inactivating outward currents at the NRs were not significantly different between the two types of fibers. Using AP-clamp, inward currents during AP upstroke were found to be insignificant difference, but amplitudes of non-inactivating outward currents during AP repolarization were significantly lower at the NRs of Aα-efferent fibers than at the NRs of Aα/β-afferent fibers in the sciatic nerves. Collectively, saltatory conduction, ionic currents, and intrinsic electrophysiological properties at the NRs of Aα/β-afferent fibers and Aα-efferent fibers in the sciatic nerves are generally similar, but some differences were also observed.</p>","PeriodicalId":19010,"journal":{"name":"Molecular Pain","volume":"19 ","pages":"17448069231187366"},"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/8b/4d/10.1177_17448069231187366.PMC10413906.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9968013","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: 10.1177/17448069231185696
Fabiana C Dias, Zilong Wang, Garrett Scapellato, Yong Chen
{"title":"Silencing of TRPV4-expressing sensory neurons attenuates temporomandibular disorders pain.","authors":"Fabiana C Dias, Zilong Wang, Garrett Scapellato, Yong Chen","doi":"10.1177/17448069231185696","DOIUrl":"https://doi.org/10.1177/17448069231185696","url":null,"abstract":"<p><p>Identification of potential therapeutic targets is needed for temporomandibular disorders (TMD) pain, the most common form of orofacial pain, because current treatments lack efficacy. Considering TMD pain is critically mediated by the trigeminal ganglion (TG) sensory neurons, functional blockade of nociceptive neurons in the TG may provide an effective approach for mitigating pain associated with TMD. We have previously shown that TRPV4, a polymodally-activated ion channel, is expressed in TG nociceptive neurons. Yet, it remains unexplored whether functional silencing of TRPV4-expressing TG neurons attenuates TMD pain. In this study, we demonstrated that co-application of a positively charged, membrane-impermeable lidocaine derivative QX-314 with the TRPV4 selective agonist GSK101 suppressed the excitability of TG neurons. Moreover, co-administration of QX-314 and GSK101 into the TG significantly attenuated pain in mouse models of temporomandibular joint (TMJ) inflammation and masseter muscle injury. Collectively, these results suggest TRPV4-expressing TG neurons represent a potential target for TMD pain.</p>","PeriodicalId":19010,"journal":{"name":"Molecular Pain","volume":"19 ","pages":"17448069231185696"},"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/5e/d3/10.1177_17448069231185696.PMC10288408.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10086699","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: 10.1177/17448069231158289
Meng Liu, Jing-Wen Mai, De-Xing Luo, Guan-Xi Liu, Ting Xu, Wen-Jun Xin, Su-Yan Lin, Zhen-Yu Li
{"title":"NFATc2-dependent epigenetic downregulation of the TSC2/Beclin-1 pathway is involved in neuropathic pain induced by oxaliplatin.","authors":"Meng Liu, Jing-Wen Mai, De-Xing Luo, Guan-Xi Liu, Ting Xu, Wen-Jun Xin, Su-Yan Lin, Zhen-Yu Li","doi":"10.1177/17448069231158289","DOIUrl":"10.1177/17448069231158289","url":null,"abstract":"<p><p>Neuropathic pain is a common dose-limiting side effect of oxaliplatin, which hampers the effective treatment of tumors. Here, we found that upregulation of transcription factor NFATc2 decreased the expression of Beclin-1, a critical molecule in autophagy, in the spinal dorsal horn, and contributed to neuropathic pain following oxaliplatin treatment. Meanwhile, manipulating autophagy levels by intrathecal injection of rapamycin (RAPA) or 3-methyladenine (3-MA) differentially altered mechanical allodynia in oxaliplatin-treated or naïve rats. Utilizing chromatin immunoprecipitation-sequencing (ChIP-seq) assay combined with bioinformatics analysis, we found that NFATc2 negatively regulated the transcription of tuberous sclerosis complex protein 2 (TSC2), which contributed to the oxaliplatin-induced Beclin-1 downregulation. Further assays revealed that NFATc2 regulated histone H4 acetylation and methylation in the <i>TSC2</i> promoter site 1 in rats' dorsal horns with oxaliplatin treatment. These results suggested that NFATc2 mediated the epigenetic downregulation of the TSC2/Beclin-1 autophagy pathway and contributed to oxaliplatin-induced mechanical allodynia, which provided a new therapeutic insight for chemotherapy-induced neuropathic pain.</p>","PeriodicalId":19010,"journal":{"name":"Molecular Pain","volume":"19 ","pages":"17448069231158289"},"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/5a/35/10.1177_17448069231158289.PMC9941598.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9483132","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: 10.1177/17448069231182501
{"title":"Corrigendum to \"Rac1/PAK1 signaling contributes to bone cancer pain by Regulation dendritic spine remodeling in rats\".","authors":"","doi":"10.1177/17448069231182501","DOIUrl":"10.1177/17448069231182501","url":null,"abstract":"","PeriodicalId":19010,"journal":{"name":"Molecular Pain","volume":"19 ","pages":"17448069231182501"},"PeriodicalIF":3.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10469238/pdf/10.1177_17448069231182501.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10522497","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: 10.1177/17448069231152125
Hong-Li Zheng, Shi-Yu Sun, Tong Jin, Ming Zhang, Ying Zeng, Qiaoqiao Liu, Kehui Yang, Runa Wei, Zhiqiang Pan, Fuqing Lin
{"title":"Transcription factor ETS proto-oncogene 1 contributes to neuropathic pain by regulating histone deacetylase 1 in primary afferent neurons.","authors":"Hong-Li Zheng, Shi-Yu Sun, Tong Jin, Ming Zhang, Ying Zeng, Qiaoqiao Liu, Kehui Yang, Runa Wei, Zhiqiang Pan, Fuqing Lin","doi":"10.1177/17448069231152125","DOIUrl":"10.1177/17448069231152125","url":null,"abstract":"<p><p>Nerve injury can induce aberrant changes in ion channels, enzymes, and cytokines/chemokines in the dorsal root ganglia (DRGs); these changes are due to or at least partly governed by transcription factors that contribute to the genesis of neuropathic pain. However, the involvement of transcription factors in neuropathic pain is poorly understood. In this study, we report that transcription factor (TF) ETS proto-oncogene 1 (ETS1) is required for the initiation and development of neuropathic pain. Sciatic nerve chronic constrictive injury (CCI, a clinical neuropathic pain model) increases ETS1 expression in the injured male mouse DRG. Blocking this upregulation alleviated CCI-induced mechanical allodynia and thermal hyperalgesia, with no apparent effect on locomotor function. Mimicking this upregulation results in the genesis of nociception hypersensitivity; mechanistically, nerve injury-induced ETS1 upregulation promotes the expression of histone deacetylase 1 (HDAC1, a key initiator of pain) via enhancing its binding activity to the HDAC1 promotor, leading to the elevation of spinal central sensitization, as evidenced by increased expression of p-ERK1/2 and GFAP in the dorsal spinal horn. It appears that the ETS1/HDAC1 axis in DRG may have a critical role in the development and maintenance of neuropathic pain, and ETS1 is a potential therapeutic target in neuropathic pain.</p>","PeriodicalId":19010,"journal":{"name":"Molecular Pain","volume":"19 ","pages":"17448069231152125"},"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/c3/7a/10.1177_17448069231152125.PMC9909074.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9295119","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":"Transcriptome analysis reveals dysregulation of inflammatory and neuronal function in dorsal root ganglion of paclitaxel-induced peripheral neuropathy rats.","authors":"Wuping Sun, Shaomin Yang, Songbin Wu, Xiyuan Ba, Donglin Xiong, Lizu Xiao, Yue Hao","doi":"10.1177/17448069221106167","DOIUrl":"https://doi.org/10.1177/17448069221106167","url":null,"abstract":"<p><p>Chemotherapy-induced peripheral neuropathy (CIPN) is the most common side-effect of anti-cancer therapy. To date, there are no clinically effective analgesics that could prevent and treat CIPN. However, the exact pathogenesis of CIPN is still unclear. In the present study, we use the paclitaxel-induced peripheral neuropathy (PIPN) model, aiming to better understand the transcriptomic level of the Dorsal root ganglia (DRG) neurons in rats with PIPN. mRNA from each DRG sample was reverse transcribed to cDNA and sequenced using next-generation high throughput sequencing technology. Quantitative RT-PCR verification was used to confirm the identified Differentially expressed genes (DEGs) in the DRG of PIPN rats. RNAseq results have identified 384 DEGs (adjusted <i>P-value</i> < 0.05; fold change ≥ 2) in the DRG of rats 14 days after paclitaxel injection in total, including 97 up-regulated genes, and 287 down-regulated genes. GO analysis revealed that these DEGs were majorly involved in neuropeptide activity, chemokine receptor activity, defense response, and inflammatory response. Kyoto Encyclopedia of Gene and Genomes analysis showed that neuroactive ligand-receptor interaction and cytokine-cytokine receptor interaction were involved in sensory neurons of rats with PIPN. Besides, comparison analysis identified that 11 DEGs in the PIPN model are shared with either inflammatory pain (Ces1d, Cfd, Retn, and Fam150b) or neuropathic pain (Atf3, Csrp3, Ecel1, Gal, Sprr1a, Tgm1, and Vip). Quantitative RT-PCR results also confirmed the validation of the RNAseq data. These results suggested that neuroactive ligand-receptor interaction and cytokine-cytokine receptor interaction are majorly involved in sensory neurons of rats with PIPN. Immune, inflammatory responses and neuron functional changes are the major pathogenesis of PIPN. Paclitaxel-induced peripheral neuropathy has shared characteristics with both inflammatory pain and neuropathic pain.</p>","PeriodicalId":19010,"journal":{"name":"Molecular Pain","volume":"19 ","pages":"17448069221106167"},"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/92/4c/10.1177_17448069221106167.PMC10227877.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9549497","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":"Mechanisms of acupuncture-electroacupuncture on inflammatory pain.","authors":"Qingxiang Zhang, Mengmeng Zhou, Mingzhu Huo, Yuxin Si, Youlin Zhang, Yuxin Fang, Di Zhang","doi":"10.1177/17448069231202882","DOIUrl":"10.1177/17448069231202882","url":null,"abstract":"<p><p>Acupuncture, as a traditional treatment, has been extensively used in China for thousands of years. According to the World Health Organization (WHO), acupuncture is recommended for the treatment of 77 diseases. And 16 of these diseases are related to inflammatory pain. As a combination of traditional acupuncture and modern electrotherapy, electroacupuncture (EA) has satisfactory analgesic effects on various acute and chronic pain. Because of its good analgesic effects and no side effects, acupuncture has been widely accepted all over the world. Despite the increase in the number of studies, the mechanisms via which acupuncture exerts its analgesic effects have not been conclusively established. A literature review of related research is of great significance to elaborate on its mechanisms and to inform on further research directions. We elucidated on its mechanisms of action on inflammatory pain from two levels: peripheral and central. It includes the mechanisms of acupuncture in the periphery (immune cells and neurons, purinergic pathway, nociceptive ion channel, cannabinoid receptor and endogenous opioid peptide system) and central nervous system (TPRV1, glutamate and its receptors, glial cells, GABAergic interneurons and signaling molecules). In this review, we collected relevant recent studies to systematically explain the mechanisms of acupuncture in treating inflammatory pain, with a view to providing direction for future applications of acupuncture in inflammatory pain and promoting clinical development.</p>","PeriodicalId":19010,"journal":{"name":"Molecular Pain","volume":" ","pages":"17448069231202882"},"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/56/ae/10.1177_17448069231202882.PMC10515556.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10534744","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}