BACKGROUND:The inflammatory response of microglia is closely related to neuronal survival,regeneration,and functional recovery after spinal cord injury.Peroxiredoxin 1 is not only involved in the regulation of oxidative stress,but also has an important effect on cell proliferation,apoptosis,and inflammatory response.OBJECTIVE:To investigate the role and mechanism of peroxiredoxin 1 in the inflammatory response of microglia following spinal cord injury.METHODS:(1)Twelve female C57BL/6 mice were randomly divided into sham-operated(n=6)and spinal cord injury(n=6)groups.The sham-operated group was not modeled and acute spinal cord injury models were constructed in the spinal cord injury group using the modified Allen's method.Spinal cord tissue at the injured site was taken at 7 days after modeling and transcriptome sequencing was performed to identify differentially expressed genes.The expression of peroxiredoxin 1 in spinal cord tissues was verified using western blot and RT-qPCR.(2)Mouse microglia BV2 were divided into two groups:the control group was stimulated with lipopolysaccharide for 6 hours,and in the knockout group,lipopolysaccharide stimulation was applied for 6 hours at 24 hours after peroxiredoxin 1 was knocked down in the cells.RT-qPCR was performed to detect mRNA expression of peroxiredoxin 1,inflammatory factors(interleukin 1β,interleukin 6,inducible nitric oxide synthase,tumor necrosis factor α,C-C motif chemokine ligand 2,and C-X-C motif chemokine ligand 2),and western blot was performed to detect the expression of peroxiredoxin 1,inducible nitric oxide synthase,and reactive oxygen/mitogen-activated protein kinase signaling pathway proteins.Mouse microglia BV2 were treated in two groups:the control group was stimulated by hydrogen peroxide for 4 hours,and the knockout group was stimulated by hydrogen peroxide for 4 hours at 24 hours after knockdown of peroxiredoxin 1.The level of reactive oxygen species was detected by 2,7-dichlorodihydrofluorescein diacetate probe.RESULTS AND CONCLUSION:(1)Results from transcriptome sequencing,western blot and RT-qPCR confirmed that peroxiredoxin 1 expression levels in mouse spinal cord tissues were significantly higher in the spinal cord injury group than the sham-operated group(P＜0.05).(2)Peroxiredoxin 1 knockdown in microglial cells led to decreased expression of peroxiredoxin 1 mRNA and protein(P＜0.05),increased mRNA expression of interleukin 1β,interleukin 6,inducible nitric oxide synthase,tumor necrosis factor α,C-C motif chemokine ligand 2,and C-X-C motif chemokine ligand 2(P＜0.05),increased protein expression of inducible nitric oxide synthase,P-P38,P-JNK and P-ERK proteins(P＜0.05),and increased level of reactive oxygen species(P＜0.05).To conclude,peroxiredoxin 1 regulates microglial inflammation by targeting the reactive oxygen species/mitogen-activated protein kinase signaling pathway.

ObjectiveSpinal cord injury (SCI) directly impairs the regulatory function of the autonomic nervous system, induces intestinal dysfunction, and significantly reduces patients’ quality of life. Preclinical studies have shown that electroacupuncture (EA) therapy can regulate the brain-gut axis and is used to treat central nervous system diseases such as major depressive disorder, Alzheimer’s disease and Parkinson’s disease. Recent research has established that fecal microbiota transplantation (FMT) from EA-treated SCI rats restored intestinal motility and colonic morphology. However, it remains unclear whether the regulation of gut microbiota by EA therapy directly contributes to neural repair after SCI. This study aims to explore whether gut microbiota mediates the neuroprotective effect of EA in the treatment of SCI and its possible mechanism. MethodsThe study employed RNA transcriptome analysis of spinal cord tissue to characterize gene expression profiles and to identify key signaling pathways following EA treatment for SCI. Hematoxylin-Eosin (HE) staining and Nissl staining were used to observe the morphological changes in spinal cord tissue. Western blot (WB) and enzyme-linked immunosorbent assay (ELISA) were applied to detect the effects of EA on the expression of proteins related to nucleotide-binding domain leucine-rich repeat and pyrin domain-containing receptor 3 (NLRP3) -dependent pyroptosis. Using 16S rDNA sequencing, the study observed alterations in gut microbiota diversity and community composition in SCI rats. Prior to establishing SCI models, rats were pretreated with an antibiotic cocktail to induce gut dysbiosis, and the effects on intestinal function and spinal cord neural repair were evaluated. FMT was performed to investigate the regulatory effects of post-EA FMT on motor function, general status, liver and spleen indices, and NLRP3-mediated pyroptosis in SCI rats. ResultsEA improved motor function and reduced regulated neuronal cell death in SCI rats. Transcriptomic analysis demonstrated the activation of immune- and inflammation-related pathways post-SCI, including NOD-like receptors, nuclear factor-kappa B(NF-κB), and Toll-like receptor (TLR) pathways. EA primarily influenced intestinal inflammation and autoimmune functions. 16S rDNA sequencing illustrated that EA did not alter the diversity of gut microbiota. However, EA altered the gut microbiota composition in SCI rats, increasing Lactobacillus and Akkermansia genera while rebalancing the Firmicutes/Bacteroidetes ratio. Furthermore, depletion of gut microbiota by antibiotics disrupted the intestinal barrier, reduced the expression of intestinal barrier proteins Zonula Occludens-1 (ZO-1) and Occludin, elevated serum lipopolysaccharide-binding protein (LBP) levels, exacerbated spinal cord tissue damage, and hindered motor function recovery in SCI rats. FMT from donors treated with EA reduced LBP levels in the intestine, blood, and spinal cord of rats, inhibited the TLR4 myeloid differentiation primary response protein 88 (MyD88)-NF‑κB pathway and NLRP3-dependent pyroptosis, and improved motor function. On the other hand, FMT treatment resulted in decreased body weight and food intake, whereas FMT using EA-treated donors effectively alleviated these alterations. ConclusionEA effectively alleviated neuroinflammatory responses in rats with SCI, primarily through regulating the gut microbiota and suppressing the NLRP3-dependent pyroptosis signaling pathway.

ObjectiveSpinal cord injury (SCI) directly impairs the regulatory function of the autonomic nervous system, induces intestinal dysfunction, and significantly reduces patients’ quality of life. Preclinical studies have shown that electroacupuncture (EA) therapy can regulate the brain-gut axis and is used to treat central nervous system diseases such as major depressive disorder, Alzheimer’s disease and Parkinson’s disease. Recent research has established that fecal microbiota transplantation (FMT) from EA-treated SCI rats restored intestinal motility and colonic morphology. However, it remains unclear whether the regulation of gut microbiota by EA therapy directly contributes to neural repair after SCI. This study aims to explore whether gut microbiota mediates the neuroprotective effect of EA in the treatment of SCI and its possible mechanism. MethodsThe study employed RNA transcriptome analysis of spinal cord tissue to characterize gene expression profiles and to identify key signaling pathways following EA treatment for SCI. Hematoxylin-Eosin (HE) staining and Nissl staining were used to observe the morphological changes in spinal cord tissue. Western blot (WB) and enzyme-linked immunosorbent assay (ELISA) were applied to detect the effects of EA on the expression of proteins related to nucleotide-binding domain leucine-rich repeat and pyrin domain-containing receptor 3 (NLRP3) -dependent pyroptosis. Using 16S rDNA sequencing, the study observed alterations in gut microbiota diversity and community composition in SCI rats. Prior to establishing SCI models, rats were pretreated with an antibiotic cocktail to induce gut dysbiosis, and the effects on intestinal function and spinal cord neural repair were evaluated. FMT was performed to investigate the regulatory effects of post-EA FMT on motor function, general status, liver and spleen indices, and NLRP3-mediated pyroptosis in SCI rats. ResultsEA improved motor function and reduced regulated neuronal cell death in SCI rats. Transcriptomic analysis demonstrated the activation of immune- and inflammation-related pathways post-SCI, including NOD-like receptors, nuclear factor-kappa B(NF-κB), and Toll-like receptor (TLR) pathways. EA primarily influenced intestinal inflammation and autoimmune functions. 16S rDNA sequencing illustrated that EA did not alter the diversity of gut microbiota. However, EA altered the gut microbiota composition in SCI rats, increasing Lactobacillus and Akkermansia genera while rebalancing the Firmicutes/Bacteroidetes ratio. Furthermore, depletion of gut microbiota by antibiotics disrupted the intestinal barrier, reduced the expression of intestinal barrier proteins Zonula Occludens-1 (ZO-1) and Occludin, elevated serum lipopolysaccharide-binding protein (LBP) levels, exacerbated spinal cord tissue damage, and hindered motor function recovery in SCI rats. FMT from donors treated with EA reduced LBP levels in the intestine, blood, and spinal cord of rats, inhibited the TLR4 myeloid differentiation primary response protein 88 (MyD88)-NF‑κB pathway and NLRP3-dependent pyroptosis, and improved motor function. On the other hand, FMT treatment resulted in decreased body weight and food intake, whereas FMT using EA-treated donors effectively alleviated these alterations. ConclusionEA effectively alleviated neuroinflammatory responses in rats with SCI, primarily through regulating the gut microbiota and suppressing the NLRP3-dependent pyroptosis signaling pathway.

Background: and Purpose Live cell-based assays (LCBA) are increasingly used for serological antibody detection due to their ability to preserve antigen conformation, offering moderately higher sensitivity than fixed cell-based assays. However, the clinical necessity of prioritizing LCBA for the detection of aquaporin-4 immunoglobulin G (AQP4-IgG) in neuromyelitis optica spectrum disorder (NMOSD) remains unclear, especially when compared to its established role in diagnosing myelin oligodendrocyte glycoprotein antibody-associated disease. Methods: We compared the performance of live cell-based assays using immunofluorescence (LCBA-IF) and fixed cell-based assays using immunofluorescence (FCBA-IF) in detecting AQP4-IgG in 90 cases of NMOSD meeting 2015 International Panel for Neuromyelitis Optica Diagnosis criteria, alongside 40 controls. Additionally, we further investigated the relationship between AQP4-IgG titers as measured by LCBA-IF and FCBA-IF and clinical parameters in NMOSD patients. Results: Results showed 96.9% agreement between LCBA-IF and FCBA-IF (Cohen’s κ=0.935), with a strong Spearman correlation (0.977, p<0.001). Both methods demonstrated 100% specificity, with LCBA-IF showing slightly higher sensitivity compared to FCBA-IF. Within LCBAIF-tested groups, statistically significant differences in annualized relapse rates were observed across all pairwise comparisons (low-titer vs. moderate-titer, low-titer vs. high-titer, and moderate-titer vs. high-titer; all p<0.050). However, this association reached statistical significance in some FCBA-IF-tested groups. Conclusions Overall, there is a strong concordance between LCBA-IF and FCBA-IF in detecting AQP4-IgG, where LCBA-IF shows slightly higher sensitivity. Furthermore, there is a potential link between elevated AQP4-IgG titers and an increased risk of relapse, and this correlation may appear more pronounced when using LCBA-IF.

ObjectiveTo investigate the migration and distribution characteristics of chemical constituents in blood and hippocampal tissues before and after vinegar processing of Citri Reticulatae Pericarpium Viride（CRPV）， and to explore the potential material basis and mechanisms underlying their regulatory effects on emotional disorders by comparing the effects of raw and vinegar-processed products of CRPV. MethodsUltra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry（UPLC-Q-TOF-MS/MS） was employed to characterize and identify the chemical constituents of raw and vinegar-processed products of CRPV extracts， as well as their migrating components in blood and hippocampal tissues after oral administration. Reference standards， databases， and relevant literature were utilized for compound annotation， with data processing performed using PeakView 1.2 software. Seventy male C57BL/6 mice were randomly divided into seven groups， including the blank group， model group， diazepam group（2.5 mg·kg^-1）， raw CRPV low/high dose groups（0.6， 1.2 g·kg^-1）， and vinegar-processed CRPV low/high dose groups（0.6， 1.2 g·kg^-1）， with 10 mice per group. Except for the blank group， all other groups underwent chronic restraint stress（2 h·d^-1） for 20 d. Each drug-treated group received oral administration at the predetermined dose starting 10 d after modeling， with a total treatment duration of 10 d. Following model-based drug administration， mice underwent open-field， forced swimming， and elevated plus maze tests. After anesthesia with isoflurane， whole brains were collected from each group of mice， and hippocampi were dissected. Reactive oxygen species（ROS） level in hippocampal tissues was quantified by enzyme-linked immunosorbent assay（ELISA）. Hematoxylin-eosin（HE） staining was used to observe hippocampal tissue morphology. Immunofluorescence was performed to detect neuronal nuclei（NeuN） and peroxisome proliferator-activated receptor alpha（PPARα） expressions in hippocampal tissue. Then， pharmacodynamic evaluations were conducted to assess the effects of raw and vinegar-processed CRPV on mood disorders， exploring the potential mechanisms. ResultsVinegar processing caused significant changes in the chemical composition of CRPV， with 18 components showing increased relative content and 35 components showing decreased relative content. The primary changes occurred in flavonoid compounds， including 20 flavonoids， 20 flavonoid glycosides， 3 triterpenes， 3 phenolic acids， 1 alkaloid， and 6 other compounds. Twenty-one components were detected in blood（15 methoxyflavones， 4 flavonoid glycosides， and 2 phenolic acids）， with 17 shared between raw and vinegar-processed CRPV. Seven components reached hippocampal tissues（all common to both forms）. In regulating emotional disorders， Vinegar-processed CRPV exhibited superior antidepressant-like effects compared to raw products. HE staining revealed that both treatments improved hippocampal neuronal morphology， particularly in the damaged CA1 and CA3 regions. Immunofluorescence and ELISA analyses demonstrated that both raw and vinegar-processed CRPV significantly modulated NeuN and PPARα expressions in hippocampal tissue while alleviating oxidative stress induced by excessive ROS（P<0.05）. ConclusionThe chemical composition of CRPV undergoes changes after vinegar processing， but the migrating components in blood and hippocampus are primarily methoxyflavonoids. These components may serve as the potential material basis for activating the PPARα pathway， thereby negatively regulating ROS generation in the hippocampus， reducing oxidative stress， and promoting the development of NeuN-positive neurons. These findings provide experimental evidence for enhancing quality standards， pharmacodynamic material research， and active drug development of raw and vinegar-processed CRPV.

Objective: To investigate the epidemiological characteristics and spatial-temporal clustering of severe fever with thrombocytopenia syndrome (SFTS) in Huai'an City, Jiangsu Province from 2011 to 2024, so as to provide a basis for optimizing local SFTS prevention and control strategies, and identifying high-risk areas and key populations. Methods: Data on SFTS incidence and deaths in Huai'an City from 2011 to 2024 were collected from the Infectious Disease Reporting Information System of the Chinese Disease Prevention and Control Information System. The reported incidence, mortality, and fatality rates were calculated. Descriptive analysis was performed on temporal, population, and regional distribution. The average annual percent change (AAPC) was used to analyze the trend in the reported incidence of SFTS. Global and local spatial autocorrelation analyses were employed to examine the spatial distribution patterns and spatial association patterns of SFTS incidence while spatio-temporal scanning analyses was used to assess the spatial-temporal clustering of SFTS. Results: A total of 337 SFTS cases were reported in Huai'an City from 2011 to 2024, with the reported incidence rising from 0.17/100 000 to 1.88/100 000. There were 20 deaths, with an average annual mortality of 0.03/100 000, and a fatality rate of 5.93%. The incidence showed obvious seasonality, with a peak in May and June (148 cases, accounting for 43.92%). Spring and summer accounted for 107 cases (31.75%) and 159 cases (47.18%), respectively. The reported SFTS cases were mainly male, farmers, and individuals aged ≥41 years, accounting for 56.38%, 79.23%, and 96.74%, respectively. The population distribution of death cases was basically consistent with that of incident cases. Xuyi County was a high-incidence area, with a total of 332 reported cases, accounting for 98.52%. All death cases were reported in this county. Spatial autocorrelation analyses revealed a positive spatial correlation in SFTS incidence from 2019 to 2024, with Moran's I values ranging from 0.214 to 0.336 (all P<0.05). Heqiao Town, Tianquanhu Town, and Guiwu Town in Xuyi County were identified as high-high clustering areas. Spatio-temporal scanning analyses showed that cluster 1 was consistent with the high-high clustering areas, with an aggregation time from the second quarter of 2019 to the second quarter of 2022. Conclusions From 2011 to 2024, the reported incidence of SFTS in Huai'an City showed an upward trend, with a high incidence in spring and summer. Males, farmers, and the middle-aged and elderly population were the key populations for prevention and control. Xuyi County was the key area for prevention and control.

ObjectiveThis study aims to investigate the action mechanism by which Xiaozheng Zhitong paste （XZP） alleviates bone cancer pain （BCP） by regulating programmed death protein 1 （PD-1）/programmed death-ligand 1 （PD-L1） pathway-induced osteoclast formation. MethodsThirty female C57BL/6 mice were randomly allocated into the following groups （n=6 per group）： normal control group， model group， low‑dose XZP group （31.5 g·kg^-1）， high‑dose XZP group （63 g·kg^-1）， and PD‑1 inhibitor （Niv） group. A bone cancer pain （BCP） model was established by injecting Lewis lung carcinoma cells. Mice in the normal control and model groups received topical application of a blank paste matrix at the wound site. Mice in the low‑ and high‑dose XZP groups were treated with XZP applied topically twice daily. Mice in the Niv group were topically administered the blank paste matrix and additionally received Niv via tail‑vein injection every two days. All interventions were continued for 21 days. During this period， behavioral tests were performed to assess mechanical， motor， and thermal nociceptive sensitivities. After 21 days， all mice were euthanized， and bone tissue from the operated side was collected for sectioning and preservation. Tartrate‑resistant acid phosphatase （TRAP） staining was used to evaluate osteoclast expression in the lesioned bone tissue. Immunohistochemistry was performed to detect the expression of Runt‑related transcription factor 2 （Runx2） in the lesioned bone tissue. Immunofluorescence was employed to assess the expression of PD‑1 and PD‑L1 in the lesioned bone tissue. ResultsCompared with the normal group， the model group showed significantly decreased limb mechanical withdrawal threshold， spontaneous paw flinching， and thermal withdrawal latency （P<0.01）， increased number of osteoclasts in the lesioned bone tissue （P<0.01）， and reduced expression of Runx2 （P<0.01）. Compared with the model group， the BCP mice in the XZP low-dose group， XZP high-dose group， and Niv group exhibited increased limb mechanical withdrawal threshold， movement scores， and thermal withdrawal latency （P<0.01）. The XZP low-dose group showed no significant changes in osteoclast number or Runx2 expression， while the XZP high-dose group and Niv group demonstrated significantly reduced osteoclast numbers （P<0.01） and significantly increased Runx2 expression （P<0.01）. In the lesioned bone tissue of BCP mice， the XZP low-dose group showed no significant decrease in the percentage of PD-1 expression， but a decrease in the percentage of PD-L1 expression （P<0.05）. In contrast， both the XZP high-dose group and the Niv group exhibited significant reductions in the percentages of PD-1 and PD-L1 expression （P<0.01）. ConclusionXZP alleviates the pain of mice with BCP by blocking the PD-1/PD-L1 pathway to inhibit osteoclastogenesis.

ObjectiveThe paper aims to investigate the mechanism by which Xiaozheng Zhitong paste （XZP） alleviates bone cancer pain （BCP） through regulating the PTEN-induced putative kinase 1 （PINK1）/Parkin-mediated mitophagy-NOD-like receptor protein 3 （NLRP3） inflammasome pathway to suppress microglial pyroptosis. MethodsLipopolysaccharide （LPS） and LPS-adenosine triphosphate （ATP） were used to establish an inflammation and pyroptosis model in microglial cells. The cells were randomly divided into the following groups： control group， LPS group， LPS+low-dose XZP group， LPS+high-dose XZP group， LPS-ATP group， LPS-ATP+low-dose XZP group， LPS-ATP+high-dose XZP group， LPS-ATP+XZP group， and LPS-ATP+XZP+CsA group. Techniques including terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling （TUNEL） staining， enzyme-linked immunosorbent assay （ELISA）， Western blot， and confocal fluorescence staining were employed to assess the effects of XZP on microglial apoptosis， inflammatory cytokine release， inflammasome activation， pyroptosis， and mitophagy. ResultsIn vitro experiments showed that compared with the blank group， the LPS group exhibited significantly increased levels of microglial apoptosis and pro-inflammatory factors interleukin （IL）-1β， IL-6， and tumor necrosis factor-α （TNF-α）（P<0.01）， along with significantly upregulated protein expression of inducible nitric oxide synthase （iNOS）， cyclooxygenase-2 （COX-2）， and phosphorylated nuclear factor-κB p65 （p-NF-κB p65） （P<0.01）. Compared with the LPS group， the high-dose LPS-XZP group significantly reduced the level of apoptosis （P<0.01） and the content of the aforementioned pro-inflammatory factors （P<0.01）. Both the low- and high-dose LPS-XZP groups dose-dependently downregulated the protein expression of iNOS， COX-2， and p-NF-κB p65 （P<0.05， P<0.01）. Compared with the blank group， the LPS-ATP group showed significantly upregulated expression of pyroptosis-related proteins， including Caspase-1/pro-Caspase-1， N-terminal fragment of gasdermin D （GSDMD-N）/full-length gasdermin D （GSDMD-F）， NLRP3， apoptosis-associated speck-like protein containing a CARD （ASC）， IL-1β precursor （pro-IL-1β）， and mature IL-1β （P<0.01）. The levels of pyroptotic factors IL-1β and IL-18 were significantly elevated （P<0.01）， and membrane pore formation and intracellular reactive oxygen species （ROS） levels were significantly increased （P<0.01）. Compared with the LPS-ATP group， both the low- and high-dose LPS-ATP+XZP groups dose-dependently downregulated the expression of the aforementioned pyroptosis-related proteins （P<0.05， P<0.01）. The low-dose LPS-ATP+XZP group reduced IL-1β levels （P<0.01）， while the high-dose group reduced both IL-1β and IL-18 levels （P<0.01） Both the low- and high-dose LPS-ATP+XZP groups dose-dependently reduced membrane pore formation and intracellular ROS production （P<0.01）. Compared with the blank group， the LPS-ATP group showed significantly reduced expression of mitophagy-related proteins PINK1 and Parkin， and a decreased ratio of microtubule-associated protein 1 light chain 3Ⅱ（LC3Ⅱ） to LC3Ⅰ（P<0.01）， while p62 expression was significantly increased （P<0.01）. Mitochondrial ROS levels were significantly enhanced （P<0.01）. Compared with the LPS-ATP group， both the low- and high-dose LPS-ATP+XZP groups dose-dependently reversed the expression of these proteins （P<0.05， P<0.01） and reduced mitochondrial ROS levels （P<0.01）. After treatment with the mitophagy inhibitor cyclosporin A （CsA）， the beneficial effects of XZP on mitochondrial function and its inhibitory effects on pyroptosis-related protein expression were significantly reversed （P<0.05， P<0.01）. ConclusionXZP reduces ROS levels by activating PINK1/Parkin-mediated mitophagy， thereby inhibiting NLRP3 inflammasome activation and microglial pyroptosis， which provides new molecular evidence for the mechanism by which XZP alleviates BCP.

ObjectiveTo investigate the effects and underlying mechanisms of Xiaozheng Zhitong Paste （XZP） on bone cancer pain （BCP）. MethodsThirty female BALB/c mice were randomly divided into five groups： a Sham group， a BCP group， a BCP+low-dose XZP group， a BCP+high-dose XZP group， and a BCP+high-dose XZP + protease-activated receptor 2 （PAR2） agonist GB-110 group. BCP mice model was constructed by injecting Lewis lung carcinoma cells into the femoral cavity of the right leg， which was followed by being treated with XZP for 21 d. After 21 d， the mice were sacrificed. Nissl staining was used to evaluate the survival of spinal cord neurons. Immunofluorescence staining was conducted to localize ionized calcium-binding adapter molecule 1 （Iba1） and neuronal nuclear antigen （NeuN） in spinal cord tissue， thereby assessing microglial activation and neuronal survival. Enzyme-linked immunosorbent assay （ELISA） was employed to measure the levels of interleukin-1β （IL-1β）， tumor necrosis factor-α （TNF-α）， interleukin-6 （IL-6）， transforming growth factor-β （TGF-β）， interleukin-4 （IL-4）， and interleukin-10 （IL-10） in spinal cord tissue. Real-time quantitative polymerase chain reaction （Real-time PCR） was used to detect mRNA expression levels associated with M1/M2 polarization of microglia. Western blot analysis was performed to examine the expression of proteins related to microglial polarization as well as those involved in the PAR2/nuclear factor kappa B （NF-κB）/NOD-like receptor protein 3 （NLRP3） signaling pathway in the spinal cord. ResultsCompared with the Sham group， the spinal cord neurons were damaged， the number of Nissl-positive spinal cord neurons in the spinal cord tissue was significantly reduced （P<0.01）， and the rate of NeuN-positive cells was significantly decreased （P<0.01）. The spinal cord microglia were activated， the inflammatory level of the spinal cord tissue was enhanced， and Iba1 staining was significantly enhanced （P<0.01）. The levels of IL-1β， TNF-α， IL-6， TGF-β， IL-4 and IL-10 were significantly increased （P<0.01）. The mRNA expressions of IL-1β， TNF-α and inducible nitric oxide synthase （iNOS） were significantly increased （P<0.01）， and the expression of PAR2， NLRP3， ASC and NF-κB p65 proteins in the spinal cord tissue of the BCP mice was significantly enhanced （P<0.01）. Compared with the BCP group， high-dose XZP treatment significantly increased the number of Nissl-positive spinal cord neurons in the BCP mice （P<0.01）， significantly enhanced the rate of NeuN-positive cells in the spinal cord tissue， and significantly weakened Iba1 staining （P<0.01）. In addition， the levels of IL-1β， TNF-α， and IL-6 were significantly decreased， while the levels of TGF-β， IL-4， and IL-10 were significantly increased （P<0.05， P<0.01）. The mRNA expression levels of IL-1β， TNF-α， and iNOS were decreased， whereas those of cluster of differentiation 206 （CD206）， arginase-1 （Arg-1）， and YM1/2 were significantly increased （P<0.05， P<0.01）. Low-dose and high-dose XZP treatment significantly decreased the expression of PAR2， NLRP3， ASC， and NF-κB p65 proteins in the spinal cord tissue （P<0.05， P<0.01）. These effects could all be significantly eliminated by the PAR2 agonist GB-110. ConclusionXZP can mitigate BCP in mice， which may be achieved through blocking the activated PAR2/NF-κB/NLRP3 pathway.

ObjectiveThe paper aims to investigate the action mechanism by which the Xiaozheng Zhitong paste （XZP） relieves bone cancer pain （BCP）. MethodsA model of mice with BCP was established by using Lewis tumor cells. The therapeutic effects of XZP， the ferroptosis inhibitor Ferrostatin-1 （Fer-1）， and the nuclear factor erythroid 2-related factor 2 （Nrf2） inhibitor Brusatol （Bru） on BCP were examined. Mice were randomly divided into the Sham operation group， BCP group， BCP+XZP-L group， BCP+XZP-H group， BCP+Fer-1 group， and BCP+XZP-H+Bru group， with six mice in each group. Pain behavior tests were conducted on the mice to assess pain levels. Colorimetric assays were employed to measure ferroptosis-related factors in serum and spinal cord tissue including Fe， malondialdehyde （MDA）， reactive oxygen species （ROS）， and superoxide dismutase （SOD）. Immunofluorescence staining was used to assess ROS production in spinal cord tissue. Transmission electron microscopy was used to observe the ultrastructure of mitochondria in lumbar spinal cord tissue. Quantitative real-time polymerase chain reaction （Real-time PCR） was employed to detect mRNA expression of Nrf2， heme oxygenase-1 （HO-1）， glutathione peroxidase 4 （GPX4）， and solute carrier family 7 member 11 （SLC7A11） in spinal cord neuron tissue. The protein expression of Nrf2， HO-1， GPX4， and SLC7A11 in spinal cord neurons was measured by Western blot. ResultsCompared with the Sham group， mice in the BCP group exhibited significantly reduced limb usage scores， mechanical foot withdrawal thresholds， and thermal foot withdrawal thresholds （P<0.01）. Serum and lumbar spinal cord tissue levels of Fe， MDA， and reactive oxygen species （ROS） were significantly elevated （P<0.05）， while superoxide dismutase （SOD） levels were significantly decreased （P<0.05）. Lumbar spinal cord mitochondrial structural damage was observed， and mRNA and protein expression of Nrf2， HO-1， GPX4， and SLC7A11 were significantly downregulated （P<0.01）. Compared with the BCP group， both low- and high-dose XZP groups improved the aforementioned pain behavioral indicators （P<0.05，P<0.01）， reduced ferroptosis-related biomarkers including Fe， MDA， and ROS levels （P<0.05）， increased SOD levels （P<0.05，P<0.01）， alleviated mitochondrial damage， and upregulated Nrf2， HO-1， GPX4， SLC7A11 mRNA and protein expression （P<0.05，P<0.01）. The high-dose XZP group exhibited comparable efficacy to Fer-1 in alleviating pain and inhibiting ferroptosis. Following Bru administration， XZP's effects on pain behavioral indicators， regulation of ferroptosis-related markers， mitochondrial structural protection， and activation of the Nrf2/HO-1/GPX4/SLC7A11 pathway were significantly reversed （P<0.05，P<0.01）. ConclusionExternal application of XZP alleviates pain symptoms in BCP mice by activating the Nrf2/HO-1/GPX4/SLC7A11 pathway， thereby inhibiting ferroptosis and neuronal damage in spinal cord neurons.