Identification and characterization of Varicella Zoster Virus circular RNA in lytic infection.

This study investigates the role of circular RNAs (circRNAs) in the context of Varicella-Zoster Virus (VZV) lytic infection. We employ two sequencing technologies, short-read sequencing and long-read sequencing, following RNase R treatment on VZV-infected neuroblastoma cells to identify and characterize both cellular and viral circRNAs. Our large scanning analysis identifies and subsequent experiments confirm 200 VZV circRNAs. Moreover, we discover numerous VZV latency-associated transcripts (VLTs)-like circRNAs (circVLTslytic), which contain multiple exons and different isoforms within the same back-splicing breakpoint. To understand the functional significance of these circVLTslytic, we utilize the Bacteria Artificial Chromosome system to disrupt the expression of viral circRNAs in genomic DNA location. We reveal that the sequence flanking circVLTs' 5' splice donor plays a pivotal role as a cis-acting element in the formation of circVLTslytic. The circVLTslytic is dispensable for VZV replication, but the mutation downstream of circVLTslytic exon 5 leads to increased acyclovir sensitivity in VZV infection models. This suggests that circVLTslytic may have a role in modulating the sensitivity to antiviral treatment. The findings shed new insight into the regulation of cellular and viral transcription during VZV lytic infection, emphasizing the intricate interplay between circRNAs and viral processes.

Lanatoside C inhibits herpes simplex virus 1 replication by regulating NRF2 distribution within cells.

BACKGROUND: In the past decades, extensive research has been conducted to identify new drug targets for the treatment of Herpes simplex virus type 1 (HSV-1) infections. However, the emergence of drug-resistant HSV-1 strains remains a major challenge. This necessitates the identification of new drugs with novel mechanisms of action. Lanatoside C (LanC), a cardiac glycoside (CG) approved by the US Food and Drug Administration (FDA), has demonstrated anticancer and antiviral properties. Nevertheless, its potential as an agent against HSV-1 infections and the underlying mechanism of action are currently unknown. PURPOSE: This study aimed to investigate the antiviral activity of LanC against HSV-1 and elucidate its molecular mechanisms. METHODS: The in vitro antiviral activity of LanC was assessed by examining the levels of viral genes, proteins, and virus titers in HSV-1-infected ARPE-19 and Vero cells. Immunofluorescence (IF) analysis was performed to determine the intracellular distribution of NRF2. Additionally, an in vivo mouse model of HSV-1 infection was developed to evaluate the antiviral activity of LanC, using indicators such as intraepidermal nerve fibers (IENFs) loss and viral gene inhibition. RESULTS: Our findings demonstrate that LanC significantly inhibits HSV-1 replication both in vitro and in vivo. The antiviral effect of LanC is mediated by the perinuclear translocation of NRF2. CONCLUSIONS: LanC exhibits anti-HSV-1 effects in viral infections, which are associated with the intracellular translocation of NRF2. These findings suggest that LanC has the potential to serve as a novel NRF2 modulator in the treatment of viral diseases.

HSV-1 infection-induced herpetic neuralgia involves a CCL5/CCR5-mediated inflammation mechanism.

Herpetic-related neuralgia (HN) caused by varicella-zoster virus (VZV) infection is one of the most typical and common neuropathic pain in the clinic. However, the potential mechanisms and therapeutic approaches for the prevention and treatment of HN are still unclear. This study aims to provide a comprehensive understanding of the molecular mechanisms and potential therapeutic targets of HN. We used an HSV-1 infection-induced HN mouse model and screened the differentially expressed genes (DEGs) in the DRG and spinal cord using an RNAseq technique. Moreover, bioinformatics methods were used to figure out the signaling pathways and expression regulation patterns of the DEGs enriched. In addition, quantitative real-time RT-PCR and western blot were carried out to further confirm the expression of DEGs. HSV-1 inoculation in mice resulted in mechanical allodynia, thermal hyperalgesia, and cold allodynia, following the infection of HSV-1 in both DRG and spinal cord. Besides, HSV-1 inoculation induced an up-regulation of ATF3, CGRP, and GAL in DRG and activation of astrocytes and microglia in the spinal cord. Moreover, 639 genes were upregulated, 249 genes were downregulated in DRG, whereas 534 genes were upregulated and 12 genes were downregulated in the spinal cord of mice 7 days after HSV-1 inoculation. GO and KEGG enrichment analysis suggested that immune responses and cytokine-cytokine receptor interaction are involved in DRG and spinal cord neurons in mice after HSV-1 infection. In addition, CCL5 and its receptor CCR5 were significantly upregulated in DRG and spinal cord upon HSV-1 infection in mice. And blockade of CCR5 exhibited a significant analgesic effect and suppressed the upregulation of inflammatory cytokines in DRG and spinal cord induced by HSV-1 infection in mice. HSV-1 infection-induced allodynia and hyperalgesia in mice through dysregulation of immune response and cytokine-cytokine receptor interaction mechanism. Blockade of CCR5 alleviated allodynia and hyperalgesia probably through the suppression of inflammatory cytokines. Therefore, CCR5 could be a therapeutic target for the alleviation of HSV-1 infection-induced HN.

Rodent models of postherpetic neuralgia: How far have we reached?

Background: Induced by varicella zoster virus (VZV), postherpetic neuralgia (PHN) is one of the common complications of herpes zoster (HZ) with refractory pain. Animal models play pivotal roles in disclosing the pain mechanisms and developing effective treatments. However, only a few rodent models focus on the VZV-associated pain and PHN. Objective: To summarize the establishment and characteristics of popular PHN rodent models, thus offer bases for the selection and improvement of PHN models. Design: In this review, we retrospect two promising PHN rodent models, VZV-induced PHN model and HSV1-induced PHN model in terms of pain-related evaluations, their contributions to PHN pathogenesis and pharmacology. Results: Significant difference of two PHN models is the probability of virus proliferation; 2) Most commonly used pain evaluation of PHN model is mechanical allodynia, but pain-induced anxiety and other behaviours are worth noting; 3) From current PHN models, pain mechanisms involve changes in virus gene and host gene expression, neuroimmune-glia interactions and ion channels; 4) antiviral drugs and classical analgesics serve more on the acute stage of herpetic pain. Conclusions: Different PHN models assessed by various pain evaluations combine to fulfil more comprehensive understanding of PHN.

Comparative Transcriptome of Dorsal Root Ganglia Reveals Distinct Etiologies of Paclitaxel- and Oxaliplatin-induced Peripheral Neuropathy in Rats.

Chemotherapy-induced peripheral neuropathy is one of the most common side effects of anticancer therapy. It is anticipated that chemotherapies with different mechanisms of action may affect somatosensory neurons differently. This study aimed to explore similar and differential etiologies of oxaliplatin- and paclitaxel-induced neuropathy by comparing the transcriptomes of dorsal root ganglia (DRGs). We retrieved our previously published transcriptome data of DRGs extracted from vehicle-, oxaliplatin- and paclitaxel-treated rats (GSE160543), to analyze in parallel the differentially expressed genes (DEGs) and Gene ontology (GO) terms enrichment. We found that both oxaliplatin and paclitaxel treatments consistently produced mechanical allodynia, thermal hyperalgesia, and cold hyperalgesia in rats. Compared to vehicle, 320 and 150 DEGs were identified after oxaliplatin and paclitaxel treatment, respectively. Only 17 DEGs were commonly dysregulated by the two reagents. Activating transcription factor 3 (Atf3), a marker of nerve injury, was elevated only after paclitaxel treatment. GO analysis suggested that paclitaxel treatment was associated with neuronal changes characterized by numerous terms that are related to synaptic transmission, while oxaliplatin was more likely to affect dividing cells (e.g., the glia) and neuroinflammation. Notably, 29 biological processes GO terms were commonly enriched in response to both drugs. However, 28 out of 29 terms were oppositely modulated. This study suggests that distinct mechanisms underly paclitaxel- and oxaliplatin-induced neuropathy. Paclitaxel might directly affect somatosensory neurons while oxaliplatin primarily targets dividing cells and immune cells.

Up-regulation of oxytocin receptors on peripheral sensory neurons mediates analgesia in chemotherapy-induced neuropathic pain.

BACKGROUND AND PURPOSE: Chemotherapy-induced neuropathic pain (CINP) currently has limited effective treatment. Although the roles of oxytocin (OXT) and the oxytocin receptor (OXTR) in central analgesia have been well documented, the expression and function of OXTR in the peripheral nervous system remain unclear. Here, we evaluated the peripheral antinociceptive profiles of OXTR in CINP. EXPERIMENTAL APPROACH: Paclitaxel (PTX) was used to establish CINP. Quantitative real-time polymerase chain reaction (qRT-PCR), in situ hybridization, and immunohistochemistry were used to observe OXTR expression in dorsal root ganglia (DRG). The antinociceptive effects of OXT were assessed by hot-plate and von Frey tests. Whole-cell patch clamp was performed to record sodium currents, excitability of DRG neurons, and excitatory synapse transmission. KEY RESULTS: Expression of OXTR in DRG neurons was enhanced significantly after PTX treatment. Activation of OXTR exhibited antinociceptive effects, by decreasing the hyperexcitability of DRG neurons in PTX-treated mice. Additionally, OXTR activation up-regulated the phosphorylation of protein kinase C (pPKC) and, in turn, impaired voltage-gated sodium currents, particularly the voltage-gated sodium channel 1.7 (NaV 1.7) current, that plays an indispensable role in PTX-induced neuropathic pain. OXT suppressed excitatory transmission in the spinal dorsal horn as well as excitatory inputs from primary afferents in PTX-treated mice. CONCLUSION AND IMPLICATIONS: The OXTR in small-sized DRG neurons is up-regulated in CINP and its activation relieved CINP by inhibiting the neural excitability by impairment of NaV 1.7 currents via pPKC. Our results suggest that OXTR on peripheral sensory neurons is a potential therapeutic target to relieve CINP.

Transcriptome analysis reveals dysregulation of inflammatory and neuronal function in dorsal root ganglion of paclitaxel-induced peripheral neuropathy rats.

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 P-value < 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.

Short-term spinal cord stimulation is an effective therapeutic approach for herpetic-related neuralgia-A Chinese nationwide expert consensus.

Purpose: Short-term spinal cord stimulation (st-SCS) has been widely used to treat herpetic-related neuralgia (HN) in China for several years, but is still heavily debated as it has no strong evidence in clinical application. Therefore, a questionnaire survey among the Chinese pain specialist workgroup of the Chinese Neuromodulation Society and Chinese Medical Doctor Association was carried out to achieve a consensus about the clinical use of st-SCS for HN treatment. Methods: The contents of the questionnaire include basic information about doctors (hospital level, work experience, training, procedure numbers, etc.), efficacy, indications, and contraindications of st-SCS, operation conditions, and preoperative preparation of st-SCS, and the prospect of the st-SCS procedure. Initially, the survey was conducted on 110 experts who have practiced the st-SCS procedure from all over the provinces in China. Finally, valuable data was calculated from the 110 questionnaires excluding the doctors with <1 year of experience of st-SCS, <10 cases of procedures per year, and no standard training in SCS technique. Results: Based on the 110 questionnaires, it is estimated that 5,000 to 10,000 cases of electrical stimulation are carried out nationwide each year. Sixty-nine valid questionnaires acquired from senior pain physicians were more valuable and specialized in the efficacy, indications, and contraindications of st-SCS for HN. It was commonly agreed (97.10%) that the HN patients with <3 months will obtain good effectiveness (patient satisfaction rate ≥50%). Almost all (98.55%) agreed that st-SCS can be used in SHN patients, there was a common agreement (72.46%) that AHN patients are an indication of st-SCS, and more than half agreement (53.62%) that st-SCS may be fit for early PHN (3-6 months). A common agreement (79.71%) was achieved that more than half of HN patients had the experience of nerve block or nerve pulsed RF. A similarly large number of experts 57/69 (82.61%) agreed that an 80% paresthesia coverage should be achieved at the test stimulation and 57/69 (82.61%) agreed that the treatment of st-SCS need be persistent for 1-2 weeks. Conclusions: Early HN patients can get an effective outcome from the treatment of st-SCS and maybe the indication of st-SCS. Moreover, standardized training for pain physicians and basic research and clinical studies are warranted.

Three-Day Continuous Oxytocin Infusion Attenuates Thermal and Mechanical Nociception by Rescuing Neuronal Chloride Homeostasis via Upregulation KCC2 Expression and Function.

Oxytocin (OT) and its receptor are promising targets for the treatment and prevention of the neuropathic pain. In the present study, we compared the effects of a single and continuous intrathecal infusion of OT on nerve injury-induced neuropathic pain behaviours in mice and further explore the mechanisms underlying their analgesic properties. We found that three days of continuous intrathecal OT infusion alleviated subsequent pain behaviours for 14 days, whereas a single OT injection induced a transient analgesia for 30 min, suggesting that only continuous intrathecal OT attenuated the establishment and development of neuropathic pain behaviours. Supporting this behavioural finding, continuous intrathecal infusion, but not short-term incubation of OT, reversed the nerve injury-induced depolarizing shift in Cl- reversal potential via restoring the function and expression of spinal K+-Cl- cotransporter 2 (KCC2), which may be caused by OT-induced enhancement of GABA inhibitory transmission. This result suggests that only continuous use of OT may reverse the pathological changes caused by nerve injury, thereby mechanistically blocking the establishment and development of pain. These findings provide novel evidence relevant for advancing understanding of the effects of continuous OT administration on the pathophysiology of pain.

Change in Cav3.2 T-Type Calcium Channel Induced by Varicella-Zoster Virus Participates in the Maintenance of Herpetic Neuralgia.

Pain, as the most prevalent neurological complication of herpes zoster (HZ), may occur before or during the rash onset or even after the rash has recovered. Particularly, postherpetic neuralgia (PHN) is a refractory chronic condition, usually defined as pain persisting for 3 months or longer from the onset of HZ. Pain evoked by HZ impairs the normal physical and emotional functions of the patients, severely reducing their quality of life. However, how zoster-associated pain occurs and develops into PHN are elusive, making PHN difficult to predict. Uncovering the pathogenesis of zoster-associated pain (or HN) helps us to better understand the onset of PHN and supports developing more effective treatments. In this study, we successfully constructed a model for zoster-associated pain through varicella-zoster virus (VZV) infections of mouse footpads and pain behavior assessments. Next, we used the Kyoto Encyclopedia of Genes and Genomes (KEGG) and the Gene Ontology (GO) to analyze PHN rodent dorsal root ganglion (DRG) gene microarray data and found that calcium signal disorder might be involved in the onset of PHN. By using reverse transcription real-time fluorescent quantitative PCR (RT-qPCR) and Western blotting, we confirmed that VZV infection could significantly upregulate the expression of T-type calcium channel Cav3.2 in DRG and spinal dorsal horn (SDH). Intrathecal administration of Cav3.2 blocker (2R/S)-6-prenylnaringenin (6-PNG) relieved mechanical and thermal hyperalgesia induced by VZV. Taken together, our data indicated that VZV might participate in the occurrence and development of HN by upregulating the expression of Cav3.2 in DRG and SDH. These findings will help to reveal the underlying mechanisms on long-lasting pain and PHN formation, providing a new insight that Cav3.2 can be the promising drug target for remitting PHN.

Direct Inhibition of Microglia Activation by Pretreatment With Botulinum Neurotoxin A for the Prevention of Neuropathic Pain.

Peripheral injection of botulinum neurotoxin A (BoNT/A) has been demonstrated to have a long-term analgesic effect in treating neuropathic pain. Around peripheral nerves, BoNT/A is taken up by primary afferent neurons and inhibits neuropeptide release. Moreover, BoNT/A could also be retrogradely transported to the spinal cord. Recent studies have suggested that BoNT/A could attenuates neuropathic pain by inhibiting the activation of spinal glial cells. However, it remains unclear whether BoNT/A directly interacts with these glial cells or via their interaction with neurons. Our aim here is to determine the direct effect of BoNT/A on primary microglia and astrocytes. We show that BoNT/A pretreatment significantly inhibits lipopolysaccharide (LPS) -induced activation and pro-inflammatory cytokine release in primary microglia (1 U/mL BoNT/A in medium), while it has no effect on the activation of astrocytes (2 U/mL BoNT/A in medium). Moreover, a single intrathecal pre-administration of a low dose of BoNT/A (1 U/kg) significantly prohibited the partial sciatic nerve ligation (PSNL)- induced upregulation of pro-inflammatory cytokines in both the spinal cord dorsal horn and dorsal root ganglions (DRGs), which in turn prevented the PSNL-induced mechanical allodynia and thermal hyperalgesia. In conclusion, our results indicate that BoNT/A pretreatment prevents PSNL-induced neuropathic pain by direct inhibition of spinal microglia activation.

Clinical Characteristics, Treatment Effectiveness, and Predictors of Response to Pharmacotherapeutic Interventions Among Patients with Herpetic-Related Neuralgia: A Retrospective Analysis.

BACKGROUND: The treatment for herpetic-related neuralgia focuses on symptom control by use of antiviral drugs, anticonvulsants, and tricyclic antidepressants. We aimed to explore the clinical characteristics associated with medication responsiveness, and to build a classifier for identification of patients who have risk of inadequate pain management. METHODS: We recruited herpetic-related neuralgia patients during a 3-year period. Patients were stratified into a medication-resistant pain (MRP) group when the pain decrease in the visual analogue scale (VAS) is < 3 points, and otherwise a medication-sensitive pain (MSP) group. Multivariate logistic regression was performed to determine the factors associated with MRP. We fitted four machine learning (ML) models, namely logistic regression, random forest, supporting vector machines (SVM), and naïve Bayes with clinical characteristics gathered at admission to identify patients with MRP. RESULTS: A total of 213 patients were recruited, and 132 (61.97%) patients were diagnosed with MRP. Subacute herpes zoster (HZ) (vs. acute, OR 8.95, 95% CI 3.15-29.48, p = 0.0001), severe lesion (vs. mild lesion, OR 3.84, 95% CI 1.44-10.81, p = 0.0084), depressed mood (unit increase OR 1.10, 95% CI 1.00-1.20, p = 0.0447), and hypertension (hypertension, vs. no hypertension, OR 0.36, 95% CI 0.14-0.87, p = 0.0266) were significantly associated with MRP. Among four ML models, SVM had the highest accuracy (0.917) and receiver operating characteristic-area under the curve (0.918) to discriminate MRP from MSP. Phase of disease is the most important feature when fitting ML models. CONCLUSIONS: Clinical characteristics collected before treatment could be adopted to identify patients with MRP.

Transcriptome Analysis Reveals the Role of Cellular Calcium Disorder in Varicella Zoster Virus-Induced Post-Herpetic Neuralgia.

As a typical neuropathic pain, post-herpetic neuralgia (PHN) is a common complication of herpes zoster (HZ), which seriously affects the normal life and work of patients. The unclear pathogenesis and lack of effective drugs make the clinical efficacy of PHN unsatisfactory. Here, we obtained the transcriptome profile of neuroblastoma cells (SH-SY5Y) and DRG in rats infected with varicella zoster virus (VZV) by transcriptome sequencing (RNA-Seq) combined with publicly available gene array data sets. Next, the data processing of the transcriptome map was analyzed using bioinformatics methods, including the screening of differentially expressed genes (DEGs), Gene Ontology (GO), and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Finally, real-time fluorescent quantitative PCR (qRT-PCR) was used to detect the expression of calcium-related genes, and calcium fluorescent probes and calcium colorimetry were used to evaluate the distribution and content of calcium ions in cells after VZV infection. Transcriptome data analysis (GO and KEGG enrichment analysis) showed that calcium disorder played an important role in SH-SY5Y cells infected by VZV and dorsal root ganglion (DRG) of the PHN rat model. The results of qRT-PCR showed that the expression levels of calcium-related genes BHLHA15, CACNA1F, CACNG1, CHRNA9, and STC2 were significantly upregulated, while the expression levels of CHRNA10, HRC, and TNNT3 were significantly downregulated in SH-SY5Y cells infected with VZV. Our calcium fluorescent probe and calcium colorimetric test results showed that VZV could change the distribution of calcium ions in infected cells and significantly increase the intracellular calcium content. In conclusion, our results revealed that the persistence of calcium disorder caused by VZV in nerve cells might be a crucial cause of herpetic neuralgia, and a potential target for clinical diagnosis and treatment of PHN.

Battlefield Acupuncture for Adult Pain: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Pain is a major public health problem, causing heavy social and economic burdens to patients and society while consuming tremendous medical resources at the same time. Thus, there is a critical need to find low-cost, efficacious, and therapeutic approaches to help manage pain. While acupuncture is increasingly recognized as a promising pain-relieving method, less is known about a specific form of auricular acupuncture known as Battlefield Acupuncture (BFA). The BFA technique involves the sequential placement of semi-permanent, single-use, French ASP[Formula: see text] golden needles to five specific acupoints in one or both ears, where they are left in place for 3-4 days or longer [Niemtzow, R.C., Battlefield acupuncture. Med. Acupunct. 19: 225-228, 2007]. The BFA needles (more accurately described as tiny conical darts) pierce the ear in designated locations in a particular order [Levy, C.E., N. Casler and D.B. FitzGerald. Battlefield acupuncture: an emerging method for easing pain. Am. J. Phys. Med. Rehabil. 97: e18-e19, 2018.]. (Figs. 4 and 5) It was developed by Dr. Richard C. Niemtzow in 2001, as a subgroup form of an auricular acupuncture technique based on the somatotopic arrangement of an inverted fetus pattern on the external ear [Romoli, M. Ear acupuncture: historical abstract-differences of ear cartography between the east and the west. Dtsch. Z. Akupunkt. 53: 24-33, 2010.]. Currently, BFA is widely used in the US military, but to our knowledge, there is no review which comprehensively synthesizes the current publications surrounding pain management. This review aims to investigate the effects and safety of BFA in adults with pain. Electronic databases were searched for randomized controlled trials (RCTs) published in English evaluating efficacy and safety of BFA in adults with pain, from database inception to September 6, 2019. The primary outcome was pain intensity change, and the secondary outcome was safety. Nine RCTs were included in this review, and five trials involving 344 participants were analyzed quantitatively. Compared with no intervention, usual care, sham BFA, and delayed BFA interventions, BFA had no significant improvement in the pain intensity felt by adults suffering from pain. Few adverse effects (AEs) were reported with BFA therapy, but they were mild and transitory. BFA is a safe, rapid, and easily learned acupuncture technique, mainly used in acute pain management, but no significant efficacy was found in adult individuals with pain, compared with the control groups. Given the poor methodological quality of the included studies, high-quality RCTs with rigorous evaluation methods are needed in the future.

Oxytocin Elicits Itch Scratching Behavior via Spinal GRP/GRPR System.

Oxytocin (OT), a neuropeptide involved in the regulation of complex social and sexual behavior in mammals, has been proposed as a treatment for a number of psychiatric disorders including pain. It has been well documented that central administration of OT elicits strong scratching and grooming behaviors in rodents. However, these behaviors were only described as symptoms, few studies have investigated their underlying neural mechanisms. Thus, we readdressed this question and undertook an analysis of spinal circuits underlying OT-induced scratching behavior in the present study. We demonstrated that intrathecal OT induced robust but transient hindpaw scratching behaviors by activating spinal OT receptors (OTRs). Combining the pre-clinical and clinical evidence, we speculated that OT-induced scratching may be an itch symptom. Further RNAscope studies revealed that near 80% spinal GRP neurons expressed OTRs. OT activated the expression of c-fos mRNA in spinal GRP neurons. Chemical ablation of GRPR neurons significantly reduced intrathecal OT-induced scratching behaviors. Given GRP/GRPR pathway plays an important role in spinal itch transmission, we proposed that OT binds to the OTRs expressed on the GRP neurons, and activates GRP/GRPR pathway to trigger itch-scratching behaviors in mice. These findings provide novel evidence relevant for advancing understanding of OT-induced behavioral changes, which will be important for the development of OT-based drugs to treat a variety of psychiatric disorders.

Spinal cord stimulation for chronic intractable trunk or limb pain: study protocol for a Chinese multicenter randomized withdrawal trial (CITRIP study).

BACKGROUND: Although effective results of many studies support the use of spinal cord stimulation in chronic pain patients, no randomized controlled trial has been undertaken in China to date. CITRIP is a multicenter, prospective, randomized, withdrawal study designed to evaluate the clinical effectiveness and safety of spinal cord stimulation plus remote programming management in patients with intractable trunk or limb pain. METHOD: Participants will be recruited in approximately 10 centers across China. Eligible participants with intractable trunk or limb and an average visual analog scale (VAS) score ≥ 5 will undergo a spinal cord stimulation test. Participants with VAS score reduction ≥ 50% could move forward to receive implantation of an implanted pulse generator. In the withdrawal period at 3-month follow-up visit, participants randomized to the experimental group (EG) will undergo continuous stimulation while ceasing the stimulation in the control group (CG). The outcome assessment will occur at baseline and at 1, 3 (pre- and post-randomization), and 6 months. The primary outcome is the difference of maximal VAS score between EG and CG in the withdrawal period compared with baseline before the withdrawal period. Additional outcomes include VAS score change at 1-, 3-, and 6-month follow-ups; responder rate (VAS score improving by 50%); achievement rate of a desirable pain state (VAS score ≤ 4); awake times during sleep; Beck Depression Inventory for depression evaluation; short-form 36 for quality of life evaluation; drug usage; and satisfaction rating of the device. Adverse events will be collected. The primary analysis will follow the intention-to-treat principle. DISCUSSION: The CITRIP study seeks to evaluate the effectiveness and safety of a randomized withdrawal trial of spinal cord stimulation for patients with intractable trunk or limb pain. TRIAL REGISTRATION: ClinicalTrials.gov NCT03858790 . Registered on March 1, 2019, retrospectively registered.

The Safety of Laser Acupuncture: A Systematic Review.

Objective: Laser acupuncture has become increasingly attractive in clinical practice, especially for patients with needle phobias well as elderly people and children. However, literature concerning the safety of laser acupuncture has been limited. This systematic review synthesizes the current available literature on the safety of laser acupuncture. Methods: Ovid MEDLINE,® Epub Ahead of Print, In-Process & Other Non-Indexed Citations Daily, Ovid Embase, Scopus, and EBM Reviews-Cochrane Central Register of Controlled Trials databases were searched for available randomized controlled trials (RCTs) on laser acupuncture. Safety data were extracted from the included studies. Adverse events (AEs) data were extracted and assessed in terms of severity and causality. Results: Of 737 articles, 21 RCTs were included. The majority of these RCTs reported that laser acupuncture was safe, without AEs; 6 trials reported AEs (including tingling, pain flare-ups, and transient fatigue). All AEs were mild and resolved spontaneously within 24 hours. The causal relationship between AEs and laser acupuncture was felt to be "certain" in 4 studies, "probable" in 1 study, and "possible" in 1 study. AEs were collected and monitored by evaluation methods in 7 trials: 5 with AE questionnaires, 1 with a checklist, and 1 with oral reports. Conclusions: Laser acupuncture appears to be a safe therapy associated with few mild and transient AEs. However, given the heterogeneity of current studies, large, well-designed placebo-controlled RCTs with rigorous evaluation methods are needed to assess the safety of laser acupuncture more completely.

Impact of herbs and dietary supplements in patients with fibromyalgia: A protocol for a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Fibromyalgia (FM) is a common chronic pain condition that seriously affects the quality of patient lives. Its etiology, pathogenesis, and treatment still remain uncertain. Dietary supplements have been widely trialed for symptom relief for FM. The review aims to synthesize the previous literature publications to assess the impact of herbs and dietary supplements on FM patients. METHODS: We will conduct a literature search in the following databases PubMed, MEDLINE, EMBASE, Cochrane Library, Scopus, and Global Health from database inception to December 2019. Clinical studies published in the English language that used human participants and address the efficacy, safety, and acceptability of herbs and dietary supplements on individuals with FM will be included. The risk of bias and quality assessment of each trial will be evaluated. If trials are enough, a meta-analysis will be conducted using software RevMan5.3, Cochrane Collaboration. RESULT: Our review will be the first attempt to facilitate evidence-based management using herbs and dietary supplements to treat patients with FM. CONCLUSION: The findings may provide a framework for future research and clinic practice in FM management. PROSPERO REGISTRATION NUMBER: CRD42020149941.