Effectiveness of acupuncture for postoperative gastrointestinal recovery in patients undergoing thoracoscopic surgery: a prospective randomized controlled study.

BACKGROUND: Postoperative gastrointestinal dysfunction (PGD) is one of the most common complications among patients who have undergone thoracic surgery. Acupuncture has long been used in traditional Chinese medicine to treat gastrointestinal diseases and has shown benefit as an alternative therapy for the management of digestive ailments. This study aimed to explore the therapeutic effectiveness of acupuncture as a means to aid postoperative recovery of gastrointestinal function in patients undergoing thoracoscopic surgery. METHODS: In total, 112 patients aged 18-70 years undergoing thoracoscopic surgery between 15 June 2022 and 30 August 2022 were randomized into two groups. Patients in the acupuncture group (AG) first received acupuncture treatment 4 h after surgery, and treatment was repeated at 24 and 48 h. Patients in the control group (CG) did not receive any acupuncture treatment. Both groups received the same anesthetic protocol. Ultrasound-guided thoracic paravertebral block (TPVB) was performed in the paravertebral spaces between T4 and T5 with administration of 20 mL of 0.33% ropivacaine. All patients received patient-controlled intravenous analgesia (PCIA) after surgery. RESULTS: Median time to first flatus [interquartile range] in the AG was significantly less than in the CG (23.25 [18.13, 29.75] vs 30.75 [24.13, 45.38] h, p < 0.001). Time to first fluid intake after surgery was significantly less in the AG, as compared with the CG (4 [3, 7] vs 6.5 [4.13, 10.75] h, p = 0.003). Static pain, measured by visual analog scale (VAS) score, was significantly different on the third day after surgery (p = 0.018). Dynamic pain VAS scores were lower in the AG versus CG on the first three postoperative days (p = 0.014, 0.003 and 0.041, respectively). CONCLUSION: Addition of acupuncture appeared to improve recovery of postoperative gastrointestinal function and alleviate posteoperative pain in patients undergoing thoracoscopic surgery. Acupuncture may represent a feasible strategy for the prevention of PGD occurrence. TRIAL REGISTRATION NUMBER: ChiCTR2200060888 (Chinese Clinical Trial Registry).

AKAP150 from nucleus accumbens dopamine D1 and D2 receptor-expressing medium spiny neurons regulates morphine withdrawal.

Dopamine D1 receptor-expressing medium spiny neurons (D1R-MSNs) and dopamine D2 receptor-expressing MSNs (D2R-MSNs) in nucleus accumbens (NAc) have been demonstrated to show different effects on reward and memory of abstinence. A-kinase anchoring protein 150 (AKAP150) expression in NAc is significantly upregulated and contributes to the morphine withdrawal behavior. However, the underlying mechanism of AKAP150 under opioid withdrawal remains unclear. In this study, AKAP150 expression in NAc is upregulated in naloxone-precipitated morphine withdrawal model, and knockdown of AKAP150 alleviates morphine withdrawal somatic signs and improves the performance of conditioned place aversion (CPA) test. AKAP150 in NAc D1R-MSNs is related to modulation of the performance of morphine withdrawal CPA test, while AKAP150 in NAc D2R-MSNs is relevant to the severity of somatic responses. Our results suggest that AKAP150 from D1R-MSNs or D2R-MSNs in NAc contributes to the developmental process of morphine withdrawal but plays different roles in aspects of behavior or psychology.

Selective activation of AKAP150/TRPV1 in ventrolateral periaqueductal gray GABAergic neurons facilitates conditioned place aversion in male mice.

Aversion refers to feelings of strong dislike or avoidance toward particular stimuli or situations. Aversion can be caused by pain stimuli and has a long-term negative impact on physical and mental health. Aversion can also be caused by drug abuse withdrawal, resulting in people with substance use disorder to relapse. However, the mechanisms underlying aversion remain unclear. The ventrolateral periaqueductal gray (vlPAG) is considered to play a key role in aversive behavior. Our study showed that inhibition of vlPAG GABAergic neurons significantly attenuated the conditioned place aversion (CPA) induced by hindpaw pain pinch or naloxone-precipitated morphine withdrawal. However, activating or inhibiting glutamatergic neurons, or activating GABAergic neurons cannot affect or alter CPA response. AKAP150 protein expression and phosphorylated TRPV1 (p-TRPV1) were significantly upregulated in these two CPA models. In AKAP150flox/flox mice and C57/B6J wild-type mice, cell-type-selective inhibition of AKAP150 in GABAergic neurons in the vlPAG attenuated aversion. However, downregulating AKAP150 in glutamatergic neurons did not attenuate aversion. Knockdown of AKAP150 in GABAergic neurons effectively reversed the p-TRPV1 upregulation in these two CPA models utilized in our study. Collectively, inhibition of the AKAP150/p-TRPV1 pathway in GABAergic neurons in the vlPAG may be considered a potential therapeutic target for the CPA response.

CircNf1-mediated CXCL12 expression in the spinal cord contributes to morphine analgesic tolerance.

BACKGROUND: Severe pain in patients can be alleviated by morphine treatment. However, long-term morphine treatment induces analgesic tolerance and the molecular mechanism of morphine analgesic intolerance is still not fully elucidated. Therefore, a novel target for improving morphine analgesic tolerance is required. Whole-genome sequencing showed that circNf1 is highly expressed in the dorsal horns of morphine-treated rats. Circular RNAs (circRNAs) are known to be unique and conserved cellular molecules that are mostly present in cytoplasm and participate in various biochemical processes with different functions. Therefore, we focused on exploring the molecular mechanism by which circNf1 contributes to morphine analgesic tolerance. METHODS: CircRNA sequencing revealed differential expression of circRNAs after morphine treatment, and bioinformatics software programs (miRNAda, PicTar, and RNAhybrid) were used to predict possible mRNAs and binding sites. RNA binding protein immunoprecipitation (RIP), chromatin isolation by RNA purification (ChIRP), fluorescence in situ hybridization (FISH), western blotting, biotin-coupled probe pull-down assay, luciferase assay, and quantitative real-time polymerase chain reaction (qRT-PCR) were conducted to detect and measure the expression levels of circRNAs, mRNAs, and proteins. Intrathecal injections of small interfering RNAs (siRNAs), microRNA (miRNA) agomirs, and functional virus microinjections were administered to artificially mediate the expression of molecules. Tail immersion and hotplate tests were performed to evaluate morphine analgesic tolerance. RESULTS: Morphine-induced circNf1 expression was high in the spinal cord. RIP-PCR and luciferase assay data showed that circNf1 could combine with both miR-330-3p and miR-665, and FISH showed that circNf1 co-localized with miR-330-3p and miR-665. qRT-PCR assay showed downregulation of miR-330-3p and miR-665 in morphine-treated rats; western blotting results showed that CXCL12 increased after morphine treatment, however, the upregulation of CXCL12 could be alleviated after the intrathecal injection of miR-330-3p as well as miR-665 agomir. qRT-PCR indicated that circNf1 can bind to CXCL12 promoter, the increased circNf1 can enhance CXCL12 mRNA in naïve rats, and inhibition of circNf1 can alleviate the upregulation of CXCL12 mRNA in morphine-treated rats. Behavioral tests revealed that inhibition of circNf1 and CXCL12 and the enhancement of miR-330-3p and miR-665 can alleviate morphine analgesic tolerance. CONCLUSIONS: Our study indicates a novel pathway that can contribute to morphine analgesic tolerance, the circRNA to cytokine pathway, in which circNf1 functions as a sponge for miR-330-3p and miR-665 and induces the upregulation of CXCL12 at both transcriptional and translational levels in morphine-treated rats.

Wnt3a/YTHDF1 Regulated Oxaliplatin-Induced Neuropathic Pain Via TNF-α/IL-18 Expression in the Spinal Cord.

Oxaliplatin is widely used in cancer treatment, however, many patients will suffer from neuropathic pain (NP) induced by it at the same time. Therefore exploring the mechanism and founding novel target for this problem are needed. In this study, YTHDF1 showed upregulation in oxaliplatin treated mice. As m6A is known as conserved and it widely functions in numerous physiological and pathological processes. Therefore, we focused on exploring the molecular mechanism of whether and how YTHDF1 functions in NP induced by oxaliplatin. IHC and western blotting were conducted to measure proteins. Intrathecal injection for corresponding siRNAs in C57/BL6 mice or spinal microinjection for virus in YTHDF1flox/flox mice were applied to specially knockdown the expression of molecular. Von Frey, acetone test and ethyl chloride (EC) test were applied to evaluate NP behavior. YTHDF1, Wnt3a, TNF-α and IL-18 were increased in oxaliplatin treated mice, restricted the molecular mentioned above respectively can significantly attenuate oxaliplatin-induced NP, including the mechanical allodynia and cold allodynia. Silencing YTHDF1 and inhibiting Wnt3a and Wnt signaling pathways can reduce the enhancement of TNF-α and IL-18, and the decreasing of the upregulation of YTHDF1 can be found when inhibiting Wnt3a and Wnts signaling pathways in oxaliplatin treated mice. Our study indicated a novel pathway that can contribute to oxaliplatin-induced NP, the Wnt3a/YTHDF1 to cytokine pathway, which upregulating YTHDF1 functioned as the downstream of Wnt3a signal and promoted the translation of TNF-α and IL-18 in oxaliplatin treated mice.

The YTHDF1-TRAF6 pathway regulates the neuroinflammatory response and contributes to morphine tolerance and hyperalgesia in the periaqueductal gray.

Long-term use of opioids such as morphine has negative side effects, such as morphine analgesic tolerance and morphine-induced hyperalgesia (MIH). These side effects limit the clinical use and analgesic efficacy of morphine. Elucidation of the mechanisms and identification of feasible and effective methods or treatment targets to solve this clinical phenomenon are important. Here, we discovered that YTHDF1 and TNF receptor-associated factor 6 (TRAF6) are crucial for morphine analgesic tolerance and MIH. The m6A reader YTHDF1 positively regulated the translation of TRAF6 mRNA, and chronic morphine treatments enhanced the m6A modification of TRAF6 mRNA. TRAF6 protein expression was drastically reduced by YTHDF1 knockdown, although TRAF6 mRNA levels were unaffected. By reducing inflammatory markers such as IL-1ß, IL-6, TNF-α and NF-κB, targeted reduction of YTHDF1 or suppression of TRAF6 activity in ventrolateral periaqueductal gray (vlPAG) slows the development of morphine analgesic tolerance and MIH. Our findings provide new insights into the mechanism of morphine analgesic tolerance and MIH indicating that YTHDF1 regulates inflammatory factors such as IL-1ß, IL-6, TNF-α and NF-κB by enhancing TRAF6 protein expression.

Efficacy and safety of the combination of propofol and S(+)-ketamine for procedural sedation in pediatric patients undergoing totally implantable venous access port implantation: A prospective randomized controlled study.

Background: Totally implantable venous access port (TIVAP) implantation is usually performed under general anesthesia with endotracheal intubation in children. Procedural sedation without endotracheal intubation has been applied to minor pediatric surgeries like central venous catheter insertion. To explore a more efficient and less invasive anesthesia mode to implant TIVAPs for children, we aimed to evaluate the efficacy and safety of procedural sedation using propofol and S(+)-ketamine compared with general anesthesia. Methods: Sixty-six patients aged 6 months to 10 years undergoing TIVAP implantation were randomly allocated to two groups. Patients under procedural sedation [S(+)-ketamine-propofol (sketofol) group] were given target-controlled infusion of propofol 4 µg/ml using the Paedfusor model and S(+)-ketamine 0.5 mg/kg as induction, and had target-controlled infusion of propofol 3-4 µg/ml as maintenance. Patients in sketofol group received medium-flow oxygen inhalation through facemasks during surgery. Patients under general anesthesia (control group) were given propofol 2 mg/kg, cisatracurium 0.2 mg/kg, fentanyl 3 µg/kg as induction, and sevoflurane 0.8 minimum alveolar concentration as maintenance after endotracheal intubation. Primary outcome was the postoperative emergence agitation evaluated 5 min after awakening. Results: Postoperative emergence agitation evaluated 5 min after awakening was lower in sketofol group versus control group [1.0 (0.5, 1.0) vs. 3.0 (2.0, 4.0); median difference (95% CI): 2.0 (1.0, 2.0); P < 0.001]. Time to awakening was significantly lower in sketofol group versus control group [15.0 (5.0, 23.0) vs. 26.0 (20.5, 37.5); median difference (95% CI): 11.0 (7.0, 19.0); P < 0.001], as well as time to discharge from post anesthesia care unit [35.0 (24.0, 45.0) vs. 45.0 (37.5, 59.5); median difference (95% CI): 10.0 (10.0, 23.0); P < 0.001]. Postoperative complications or adverse events were not reported in sketofol group. Conclusions: Compared to general anesthesia with endotracheal intubation, procedural sedation using propofol and S(+)-ketamine improves the postoperative emergence agitation right after the recovery of consciousness, and has advantage in shortening anesthetic recovery time for pediatric patients undergoing TIVAP implantation.

Correction to: Correlations between meteorological indicators, air quality and the COVID-19 pandemic in 12 cities across China.

[This corrects the article DOI: 10.1007/s40201-020-00564-y.].

The use of Esketamine in CT-guided percutaneous liver tumor ablation reduces the consumption of remifentanil: a randomized, controlled, double-blind trial.

Background: In the anesthesia management of percutaneous liver tumor ablation, the requirement of analgesia is very strict. Currently, intravenous anesthesia is commonly used, such as remifentanil combined with sedative drugs. However, the pain relief is not instantaneous after increasing the dosage of remifentanil. Esketamine, a medium- or long-term analgesic drug, does not inhibit respiration to maintain patient comfort during the ablation and reduces the consumption of remifentanil. Therefore, this experiment was designed to investigate the potential of combinational therapy and the most appropriate dose of esketamine. Methods: A total of 120 patients were randomly divided into three groups by SPSS. The regular anesthesia model included dexmedetomidine 0.5 µg/kg, intravenous glucose tolerance test, remifentanil continuous infusion, flurbiprofen 50 mg, i.v., palonosetron 0.225 mg, i.v., and 1% lidocaine for local anesthesia. Group A was the regular control group, only using the regular model; Group B also received with 0.1 mg/kg esketamine, i.v.; and Group C also received 0.2 mg/kg esketamine, i.v.. The whole experiment was double-blind. Results: From December 2020 to March 2021, 120 patients were randomized in total, and 108 were included in the analysis: 36, 37, 35 were allocated to Group A, Group B, and Group C, respectively. The total dosage of remifentanil in Group A, Group B, Group C was 179.38±123.37, 120.31±57.96 and 115.91±62.42 µg, respectively. We found the total dosage of remifentanil in Group B and Group C were significantly decreased in comparison to that of Group A (P=0.004, P=0.003, respectively). The maximum dosage of remifentanil in Group A, Group B, and Group C was 1.76±0.62, 1.37±0.47, and 1.33±0.56 ng/mL, respectively. The maximum dosage of remifentanil in Group B and Group C were significantly decreased in comparison to that of Group A (P=0.003, P=0.001, respectively). The incidence of severe pain during the ablation in Group B was significantly lower than that in Group A (3 vs. 12, P<0.05). Conclusions: The use of esketamine can reduce the dosage of opioids for liver tumor ablation and reduce the occurrence of severe pain. We found that 0.1 mg/kg esketamine, i.v. is the most suitable dose for liver tumor ablation. Trial Registration: Chinese Clinical Trial Registry ChiCTR2100049152.

Antinociceptive Effects and Interaction Mechanisms of Intrathecal Pentazocine and Neostigmine in Two Different Pain Models in Rats.

Background: Pentazocine produces a wide variety of actions in the treatment of perioperative analgesia. Neostigmine is a cholinesterase inhibitor used to antagonize the residual effects of muscle relaxants and also produces an analgesic effect. Objectives: To investigate the analgesic effects of intrathecally injected pentazocine and neostigmine and their interaction. Methods: Sprague-Dawley rats were used to test the analgesic effect of pentazocine and neostigmine using the paw formalin pain model and the incision mechanical allodynia model. Pentazocine (3, 10, 30, and 100 µg), neostigmine (0.3, 1, 3, and 10 µg) or a pentazocine-neostigmine mixture were separately injected to evaluate their antinociceptive effects alone on the treatment groups. The corresponding control group received an intrathecal injection containing the same volume of saline. The formalin pain test, or the plantar incision pain behavior test were performed 30 minutes later. Isobolographic analysis was used to evaluate the interaction between pentazocine and neostigmine. Intrathecally administered selective mu-opioid receptor antagonist CTAP, selective kappa-opioid receptor antagonist nor-Binaltorphimine (nor-BNI), nonselective opioid receptor antagonist naloxone, and muscarinic acetylcholine receptor antagonist atropine were also used to test the possible interaction mechanism. These antagonists were used 30 minutes before the pentazocine and neostigmine mixtures which were intrathecally injected. Results: Intrathecally administered pentazocine (3, 10, 30, and 100 µg) and neostigmine (0.3, 1, 3, and 10 µg) alone had a marked dose-related impact on suppressing the biphasic responses in the formalin test. Pentazocine (3, 10, 30, and 100 µg) and neostigmine (0.3, 1, 3, and 10 µg) alone attenuated the mechanical allodynia in a plantar incision model in a dose-dependent manner. Isobolographic analysis revealed that the mixture of intrathecal pentazocine and neostigmine synergistically decreased both phase I and II activity in the formalin test and mechanical allodynia in the plantar incision model. Pretreatment of intrathecally administered nor-BNI, naloxone, atropine, but not CTAP, antagonized the analgesic effect of the pentazocine-neostigmine mixture. Conclusions: All of these results suggest that the combined application of pentazocine and neostigmine is an effective way to relieve pain from formalin and acute incision mechanical allodynia. The synergistic effect between pentazocine and neostigmine is mostly attributed to the kappa-opioid receptor and the cholinergic receptor in the spinal cord.

Ganglioside-monosialic acid (GM1) for prevention of chemotherapy-induced peripheral neuropathy: a meta-analysis with trial sequential analysis.

BACKGROUND: Chemotherapy-induced peripheral neuropathy (CIPN) is a dose-limiting side effect that largely remains an unresolved clinical issue, leading to long-term morbidity. This meta-analysis aimed to evaluate the efficacy and safety of Ganglioside-monosialic acid (GM1) in preventing CIPN. METHODS: Systematic literature searches of PubMed, Web of Science, Embase, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov were performed to identify randomized controlled trials and cohort studies that evaluated the efficacy of GM1 for preventing CIPN. Conventional meta-analysis with a random-effects model and trial sequential analysis (TSA) were performed. RESULTS: A total of five studies involving 868 participants were included. The results showed that GM1 did not reduce the overall incidence of grade ≥ 2 CIPN when the common terminology criteria for adverse events (CTCAE) was used (OR 0.34, 95% CI 0.34-1.11). Subgroup analyses showed that GM1 could not reduce the risk of CTCAE grade ≥ 2 CIPN (OR 0.63, 95% CI 0.35-1.13) and neurotoxicity criteria of Debiopharm (DEB-NTC) grade ≥ 2 CIPN (OR 0.25, 95% CI 0.01-7.10) in oxaliplatin-treated patients, despite that GM1 was associated with a reduced risk of CTCAE grade ≥ 2 CIPN in the taxane subgroup of one study (OR 0.003, 95% CI 0.00-0.05). These results were confirmed by the sub-analysis of randomized controlled trials (RCTs). In TSA, the z-curve for the taxane subgroup crossed the upper trial sequential monitoring boundary (TSMB) but do not reach the required information size (RIS). The z-curves for the oxaliplatin subgroup remained in the nonsignificant area and did not reach the RIS. Further, GM1 did not influence the rate of response to chemotherapy and CTCAE grade ≥ 2 adverse events such as fatigue, nausea, diarrhea, and rash. CONCLUSIONS: GM1 seemed to be well-tolerated and did not influence the anti-cancer effects of chemotherapeutic agents. Although the data did not confirm the effectiveness of GM1 in preventing oxaliplatin-induced peripheral neuropathy, GM1 might be able to prevent taxane-induced peripheral neuropathy. More studies are required in different ethnic populations receiving taxane-based chemotherapy to confirm these findings.

Correlations between Meteorological Indicators, Air Quality and the COVID-19 Pandemic in 12 Cities across China.

BACKGROUND: COVID-19 is a global pandemic. The purpose of this study is to explore correlations between the novel coronavirus (COVID-19) and meteorological indicators from cities across China. METHODS: We collected daily data of the cumulative number of infected, recovered and death cases, and the meteorological indicators including average temperature, wind speed, relative humidity, precipitation and air quality index (AQI) from 12 cities in China during the period of Jan 23 to Feb 22, 2020. Correlation tests were chosen for data analysis. RESULTS: The average temperature and AQI showed significant association with the mortality rate of COVID-19. The mortality rate was not correlated with wind speed, relative humidity or precipitation. Meanwhile, higher average temperatures and more precipitation were beneficial for the recovery rate of COVID-19, but the recovery rate was not correlated with wind speed, relative humidity or AQI. CONCLUSIONS: Our study provides a new basis for correlations between COVID-19, meteorological indicators and air quality index, which can help authorities to combat COVID-19.

Distinct roles of srGAP3-Rac1 in the initiation and maintenance phases of neuropathic pain induced by paclitaxel.

KEY POINTS: Spinal cord dorsal horn srGAP3 (slit-robo GTPase activating protein 3) increases in the initiation phase of neuropathic pain and decreases in the maintenance phase. However, Rac1 activity, which can be reduced by srGAP3, decreases in the initiation phase and increases in the maintenance phase. The increased srGAP3 in the initiation phase promotes new immature dendritic spines instigating neuropathic pain. Decreased srGAP3 in the maintenance phase enhances Rac1 activity facilitating maturation of dendritic spines and the persistence of neuropathic pain. SrGAP3 small interfering RNA can ameliorate neuropathic pain only when administrated in the initiation phase. The Rac1 inhibitor can ameliorate neuropathic pain only when administrated in the maintenance phase. Combined targeting of srGAP3 in the initiation phase and Rac1 in the maintenance phase can produce optimal analgesic efficacy. ABSTRACT: Neuropathic pain includes an initiation phase and maintenance phase, each with different pathophysiological processes. Understanding the synaptic plasticity and molecular events in these two phases is relevant to exploring precise treatment strategies for neuropathic pain. In the present study, we show that dendritic spine density increases in the spinal dorsal horn in the initiation phase of neuropathic pain induced by paclitaxel and that the spine maturity ratio increases in the maintenance phase. Increased srGAP3 (slit-robo GTPase activating protein 3) facilitates dendritic spine sprouting in the initiation phase. In the maintenance phase, srGAP3 decreases to upregulate Rac1 activity, which facilitates actin polymerization and dendritic spine maturation and thus the persistence of neuropathic pain. Knockdown of srGAP3 in the initiation phase or inhibition of Rac1 in the maintenance phase attenuates neuropathic pain. Combined intervention of srGAP3 in the initiation phase, and Rac1 in the maintenance phase shows better analgesic efficacy against neuropathic pain. The present study demonstrates the role of srGAP3-Rac1 in dendritic spine plasticity in the two phases of neuropathic pain and, accordingly, provides treatment strategies for different phases of neuropathic pain.

Oxaliplatin Regulates Chemotherapy Induced Peripheral Neuropathic Pain in the Dorsal Horn and Dorsal Root Ganglion via the Calcineurin/NFAT Pathway.

OBJECTIVE: The aim of this study was to investigate the mechanism of oxaliplatin in the induction of neuropathic pain as a symptom of Chemotherapy-Induced Peripheral Neuropathy (CIPN). METHODS: The CIPN rat model was induced with a one-time injection of oxaliplatin, and the paw withdrawal response was determined using von Frey filaments. The Paw Withdrawal Threshold (PWT) value was recorded and the Dorsal Horn (DH) and Dorsal Root Ganglion (DRG) tissues were collected. The mRNA and protein levels of Calcineurin (CaN), Nuclear Factor of Activated T cells (NFAT), and other relevant cytokines were determined. CaN and NFAT inhibition reagents, FK506 and 11R-VIVIT, were applied in order to investigate the functions of the CaN/NFAT pathway in the neuropathic pain processes. The levels of the downstream inflammatory cytokines, TNF-α and IL-1ß, were assessed by ELISA. RESULTS: The application of oxaliplatin reduced the value of PWT by 4 times on days 7（4±1.33）and 14（5.13±3.07）compared with the control group(14±0.91; 13.67±0.76). After treatment, the CaN mRNA level decreased and that of NFAT increased in DH and DRG tissues (P<0.05). However, treatment with FK506 and 11R-VIVIT decreased the value of PWT that had increased after oxaliplatin treatment. The expression of downstream cytokines related to the CaN/NFAT pathway increased, including CCR2, COX2, p-ERK, and p-P38 (all p<0.05). In addition, when the CaN/NFAT pathway was activated, the concentration of TNFα increased to 40pg/mg in DH tissues and 60pg/mg in DRG tissues compared with the control group, while the concentration of IL-1ß increased to over 60pg/mg in DH and DRG tissues. CONCLUSION: It was the first time to prove that oxaliplatin-induced neuropathic pain was correlated to the activation of the CaN/NFAT pathway in our rat model. This finding can provide a new direction to explore the mechanism of oxaliplatin-induced neuropathic pain.

Bulleyaconitine A attenuates hyperexcitability of dorsal root ganglion neurons induced by spared nerve injury: The role of preferably blocking Nav1.7 and Nav1.3 channels.

Background Oral administration of Bulleyaconitine A, an extracted diterpenoid alkaloid from Aconitum bulleyanum plants, is effective for treating chronic pain in rats and in human patients, but the underlying mechanisms are poorly understood. Results As the hyperexcitability of dorsal root ganglion neurons resulting from the upregulation of voltage-gated sodium (Nav) channels has been proved critical for development of chronic pain, we tested the effects of Bulleyaconitine A on Nav channels in rat spared nerve injury model of neuropathic pain. We found that Bulleyaconitine A at 5 nM increased the threshold of action potentials and reduced the firing rate of dorsal root ganglion neurons in spared nerve injury rats but not in sham rats. Bulleyaconitine A preferably blocked tetrodotoxin-sensitive Nav channels over tetrodotoxin-resistant ones in dorsal root ganglion neurons of spared nerve injury rats. Bulleyaconitine A was more potent for blocking Nav1.3 and Nav1.7 than Nav1.8 in cell lines. The half maximal inhibitory concentration (IC50) values for resting Nav1.3, Nav1.7, and Nav1.8 were 995.6 ± 139.1 nM, 125.7 ± 18.6 nM, and 151.2 ± 15.4 µM, respectively, which were much higher than those for inactivated Nav1.3 (20.3 ± 3.4 pM), Nav1.7 (132.9 ± 25.5 pM), and Nav1.8 (18.0 ± 2.5 µM). The most profound use-dependent blocking effect of Bulleyaconitine A was observed on Nav1.7, less on Nav1.3, and least on Nav1.8 at IC50 concentrations. Bulleyaconitine A facilitated the inactivation of Nav channels in each subtype. Conclusions Preferably blocking tetrodotoxin-sensitive Nav1.7 and Nav1.3 in dorsal root ganglion neurons may contribute to Bulleyaconitine A's antineuropathic pain effect.

Upregulation of NLRP3 via STAT3-dependent histone acetylation contributes to painful neuropathy induced by bortezomib.

Painful neuropathy, as a severe side effect of chemotherapeutic bortezomib, is the most common reason for treatment discontinuation. However, the mechanism by which administration of bortezomib leads to painful neuropathy remains unclear. In the present study, we found that application of bortezomib significantly increased the expression of NOD-like receptor family pyrin domain containing 3 (NLRP3) and phosphorylated signal transducer and activator of transcription-3 (STAT3) in dorsal root ganglion (DRG). Intrathecal injection of NLRP3 siRNA significantly prevented the mechanical allodynia induced by bortezomib treatment, and intrathecal injection of recombinant adeno-associated virus vector encoding NLRP3 markedly decreased paw withdrawal threshold of naive rats. Furthermore, the expressions of p-STAT3 were colocalized with NLRP3-positive cells in DRG neurons, and inhibition of STAT3 by intrathecal injection of AAV-Cre-GFP into STAT3flox/flox mice or inhibitor S3I-201 suppressed the upregulation of NLRP3 and mechanical allodynia induced by bortezomib treatment. Chromatin immunoprecipitation further found that bortezomib increased the recruitment of STAT3, as well as the acetylation of histone H3 and H4, in the NLRP3 promoter region in DRG neurons. Importantly, inhibition of the STAT3 activity by using S3I-201 or DRG local deficiency of STAT3 also significantly prevented the upregulated H3 and H4 acetylation in the NLRP3 promoter region following bortezomib treatment. Altogether, our results suggest that the upregulation of NLRP3 in DRG via STAT3-dependent histone acetylation is critically involved in bortezomib-induced mechanical allodynia.

AKAP150 involved in paclitaxel-induced neuropathic pain via inhibiting CN/NFAT2 pathway and downregulating IL-4.

Antitubulin chemotherapeutics agents, such as paclitaxel, are effective chemotherapy drugs for cancer treatment. However, painful neuropathy is a major adverse effect limiting the wider application of chemotherapeutics. In this study, we found that A-kinase anchor protein 150 (AKAP150) was significantly upregulated after paclitaxel injection. Inhibition of AKAP150 via siRNA or AKAP150flox/flox in rodents alleviated the pain behavior induced by paclitaxel, and partly restored the decreased calcineurin (CN) phosphatase activity after paclitaxel treatment. Paclitaxel decreased the expression of anti-inflammatory cytokine interleukin-4 (IL-4), and intrathecal injections of IL-4 effectively alleviated paclitaxel-induced hypersensitivity and the frequency of dorsal root ganglion (DRG) neurons action potential. The decreased CN enzyme activity, resulted in reduced protein expression of nuclear factor of activated T cells 2 (NFAT2) in cell nuclei. Chromatin immunoprecipitation showed that, NFAT2 binds to the IL-4 gene promoter regulating the protein expression of IL-4. Overexpression of NFAT2 by intrathecal injection of the AAV5-NFAT2-GFP virus alleviated the pain behavior induced by paclitaxel via increasing the expression of IL-4. Knocked down AKAP150 by siRNA or AAV5-Cre-GFP partly restored the expression of IL-4 in DRG. Our results indicated that regulation of IL-4 via the CN/NFAT2 pathway mediated by AKAP150 could be a pivotal treatment target for paclitaxel-induced neuropathic pain and or other neuropsychiatric disorders.

Synergistic Interaction Between Dexmedetomidine and Ulinastatin Against Vincristine-Induced Neuropathic Pain in Rats.

Antimicrotubulin chemotherapeutic agents such as vincristine (VCR), often induce peripheral neuropathic pain. It is usually permanent and seriously harmful to cancer patients' quality of life and can result in the hampering of clinical treatments. Currently, there is no definitive therapy, and many of the drugs approved for the treatment of other neuropathic pain have shown little or no analgesic effect. It is therefore vital to find new and novel therapeutic strategies for patients suffering from chemotherapeutic agent-induced neuropathic pain to improve patients' quality of life. This study shows that intrathecal injections of dexmedetomidine (DEX), or intraperitoneally administered ulinastatin (UTI) significantly reduces Sprague Dawley rats' mechanical allodynia induced by VCR via upregulation of interleukin-10 expression and activating the α2-adrenergic receptor in dorsal root ganglion (DRG). Moreover, when combined there is a synergistic interaction between DEX and UTI, which acts against VCR-induced neuropathic pain. This synergistic interaction between DEX and UTI may be partly attributed to a common analgesic pathway in which the upregulation of interleukin -10 plays an important role via activating α2-adrenergic receptor in rat dorsal root ganglion. The combined use of DEX and UTI does not affect the rat's blood pressure, heart rate, sedation, motor score, spatial learning, or memory function. All of these show that the combined use of DEX and UTI is an effective method in relieving VCR-induced neuropathic pain in rats. PERSPECTIVE: This article documents the synergistic interaction between 2 widely used drugs, DEX and UTI, against VCR-induced neuropathic pain. The results provide a potential target and novel drug administrated method for the clinical treatment of chemotherapy-induced peripheral neuropathic pain.

Activation of RAGE/STAT3 pathway by methylglyoxal contributes to spinal central sensitization and persistent pain induced by bortezomib.

Bortezomib is a first-line chemotherapeutic drug widely used for multiple myeloma and other nonsolid malignancies. Although bortezomib-induced persistent pain is easily diagnosed in clinic, the pathogenic mechanism remains unclear. Here, we studied this issue with use of a rat model of systemic intraperitoneal administration of bortezomib for consecutive 5days. Consisted with our previous study, we found that bortezomib treatment markedly induced mechanical allodynia in rats. Furthermore, we first found that bortezomib treatment significantly induced the upregulation of methylglyoxal in spinal dorsal horn of rats. Spinal local application of methylglyoxal also induced mechanical allodynia and central sensitization in normal rats. Moreover, administration of bortezomib upregulated the expression of receptors for advanced glycation end products (RAGE) and phosphorylated STAT3 (p-STAT3) in dorsal horn. Importantly, intrathecal injection of metformin, a known scavenger of methylglyoxal, significantly attenuated the upregulation of methylglyoxal and RAGE in dorsal horn, central sensitization and mechanical allodynia induced by bortezomib treatment, and blockage of RAGE also prevented the upregulation of p-STAT3, central sensitization and mechanical allodynia induced by bortezomib treatment. In addition, inhibition of STAT3 activity by S3I-201 attenuated bortezomib-induced mechanical allodynia and central sensitization. Local knockdown of STAT3 also ameliorated the mechanical allodynia induced by bortezomib administration. Our results suggest that accumulation of methylglyoxal may activate the RAGE/STAT3 signaling pathway in dorsal horn, and contributes to the spinal central sensitization and persistent pain induced by bortezomib treatment.