Stigmasterol regulates microglial M1/M2 polarization via the TLR4/NF-κB pathway to alleviate neuropathic pain.

(Switching from the microglial M1 phenotype to the M2 phenotype is a promising therapeutic strategy for neuropathic pain (NP). This study aimed to investigate the potential use of stigmasterol for treating NP. In animal experiments, 32 male Sprague-Dawley rats were randomly divided into the sham operation group, chronic constriction injury (CCI) group, CCI + ibuprofen group, and CCI + stigmasterol group. We performed behavioral tests, enzyme-linked immunosorbent assay, hematoxylin-esoin staining (H&E) staining and immunohistochemistry, immunofluorescence, and Western blotting. In cell experiments, we performed flow cytometry, immunofluorescence, Western blotting, and qRT-PCR. Stigmasterol reduced thermal and mechanical hyperalgesia and serum IL-1ß and IL-8 levels and increased serum IL-4 and TGF-ß levels in CCI rats. Stigmasterol reduced IL-1ß, COX-2, and TLR4 expression in the right sciatic nerve and IL-1ß expression in the spinal cord. Stigmasterol reduced the expression of Iba-1, TLR4, MyD88, pNF-κB, pP38 MAPK, pJNK, pERK, COX-2, IL-1ß, and CD32 in the spinal cord of CCI rats while increasing the expression of IL-10 and CD206. Stigmasterol decreased M1 polarization markers and increased M2 polarization markers in lipopolysaccharide (LPS)-induced microglia and decreased the expression of Iba-1, TLR4, MyD88, pNF-κB, pP38 MAPK, pJNK, pERK, iNOS, COX-2, and IL-1ß in LPS-treated microglia while increasing the expression of Arg-1 and IL-10. Stigmasterol regulates microglial M1/M2 polarization via the TLR4/NF-κB pathway to alleviate NP.

ß-Sitosterol Alleviates Neuropathic Pain by Affect Microglia Polarization through Inhibiting TLR4/NF-κB Signaling Pathway.

The etiology of neuropathic pain is mostly caused by mechanical deformation and neuroinflammation, of which neuroinflammation is the main cause of chronic neuropathic pain. Activation of the TLR4/NF-κB signaling pathway mediates elevated levels of inflammatory cytokines, and we clearly demonstrated by in vivo and in vitro Western blot experiments that ß-sitosterol significantly inhibited the elevated Toll-like receptor 4 (TLR4) expression levels and nuclear factor-kappa B (NF-κB) activation associated with inflammatory responses. In cellular experiments, we clearly saw that both ß-sitosterol and TLR4/NF-κB signaling pathway inhibitors could inhibit M1 proinflammatory phenotype expression and promote M2 anti-inflammatory phenotype expression in GMI-R1 microglia by flow cytometry and immunofluorescence assays. Therefore, we suggest that ß-sitosterol can affect microglial polarization by inhibiting the TLR4/NF-κB signaling pathway thereby reducing neuroinflammation and thus alleviating neuropathic pain.

(+)-Catechin Alleviates CCI-Induced Neuropathic Pain in Rats by Modulating the IL34/CSFIR Axis and Attenuating the Schwann Cell-Macrophage Cascade Response in the DRG.

The aim of this study was to investigate the potential therapeutic applications of (+)-catechin in the treatment of neuropathic pain. In vivo study, 32 SD rats were randomly divided into four groups: sham group, chronic constriction injury (CCI) group, CCI + ibuprofen group and CCI+ (+)-catechin group. They were subjected to behavioural tests, ELISA, immunohistochemistry and Western blotting. The mechanisms involved were investigated using specific inhibitors in cell experiments. Results of in vivo experiments showed that (+)-catechin could reduce the cold sensitivity pain in a rat model of CCI; ELISA and immunohistochemistry results showed that (+)-catechin could decrease the levels of IL-8, IL-6, TNF-α, CCL2 and CCL5 in serum and the expression levels of nNOS, COX2, IL6, TNF-α, IBA-1 and CSF1R in DRG of CCI rats. Finally, western blot confirmed that (+)-catechin could diminish the levels of IL-34/CSF1R/JAK2/STAT3 signalling pathway in DRG of CCI rats. In vitro studies showed that (+)-catechin reduced IL-34 secretion in LPS-induced RSC96 cells. Meanwhile, (+)-catechin administration in LPS-induced Schwann cell-conditioned medium (L-CM) significantly inhibited the proliferation and migration of RAW264.7 cells; in addition, L-CM+(+)-catechin reduced the activation of the CSF1R/JAK2/STAT3 signalling pathway. (+)-Catechin attenuated the Schwann cell-macrophage cascade response in the DRG by modulating the IL34/CSFIR axis and inhibiting activation of the JAK2/STAT3 pathway, thereby attenuating CCI-induced neuropathic pain in rats.

Fully endoscopic microvascular decompression for the treatment of hemifacial spasm, trigeminal neuralgia, and glossopharyngeal neuralgia: a retrospective study.

BACKGROUND: Microvascular decompression (MVD) is already the preferred surgical treatment for medically refractory neurovascular compression syndromes (NVC) such as hemifacial spasm (HFS), trigeminal neuralgia (TN), and glossopharyngeal neuralgia (GPN). Endoscopy has significantly advanced surgery and provides enhanced visualization of MVD. The aim of this study is to analyze the efficacy and safety of fully endoscopic microvascular decompression (E-MVD) for the treatment of HFS, TN, and GPN, as well as to present our initial experience. MATERIALS AND METHODS: This retrospective case series investigated fully E-MVD performed in 248 patients (123 patients with HFS, 115 patients with TN, and 10 patients with GPN ) from December 2008 to October 2021 at a single institution. The operation duration, clinical outcomes, responsible vessels, intra- and postoperative complications, and recurrences were recorded. Preoperative and immediate postoperative magnetic resonance imaging (MRI) and computerized tomography (CT) were performed for imageological evaluation. The Shorr grading and Barrow Neurological Institute (BNI) pain score were used to evaluate clinical outcomes. The efficacy, safety, and risk factors related to the recurrence of the operation were retrospectively analysed, and the surgical techniques of fully E-MVD were summarised. RESULTS: A total of 248 patients (103 males) met the inclusion criteria and underwent fully E-MVD were retrospectively studied. The effective rate of 123 patients with HFS was 99.1%, of which 113 cases were completely relieved and 9 cases were significantly relieved. The effective rate of 115 patients with TN was 98.9%, of which 105 cases had completely pain relieved after surgery, 5 cases had significant pain relieved, 4 cases had partial pain relieved but still needed to be controlled by medication. The effective rate of 10 patients with GPN was 100%, 10 cases of GPN were completely relieved after surgery. As for complications, temporary facial numbness occurred in 4 cases, temporary hearing loss in 5 cases, dizziness with frequent nausea and vomiting in 8 cases, headache in 12 cases, and no cerebral hemorrhage, intracranial infection, and other complications occurred. Follow-up ranged from 3 to 42 months, with a mean of 18.6 ± 3.3 months. There were 4 cases of recurrence of HFS and 11 cases of recurrence of TN. The other effective patients had no recurrence or worsening of postoperative symptoms. The cerebellopontine angle (CPA) area ratio (healthy/affected side), the length of disease duration, and the type of responsible vessels are the risk factors related to the recurrence of HFS, TN, and GPN treated by fully E-MVD. CONCLUSIONS: In this retrospective study, our results suggest that the fully E-MVD for the treatment of NVC such as HFS, TN, and GPN, is a safe and effective surgical method. Fully E-MVD for the treatment of NVC has advantages and techniques not available with microscopic MVD, which may reduce the incidence of surgical complications while improving the curative effect and reducing the recurrence rate.

Paeonol alleviates neuropathic pain by modulating microglial M1 and M2 polarization via the RhoA/p38MAPK signaling pathway.

BACKGROUND: This study aimed to investigate the potential mechanism of paeonol in the treatment of neuropathic pain. METHODS: Relevant mechanisms were explored through microglial pseudotime analysis and the use of specific inhibitors in cell experiments. In animal experiments, 32 SD rats were randomly divided into the sham operation group, the chronic constrictive injury (CCI) group, the ibuprofen group, and the paeonol group. We performed behavioral testing, ELISA, PCR, Western blotting, immunohistochemistry, and immunofluorescence analysis. RESULTS: The pseudotime analysis of microglia found that RhoA, Rock1, and p38MAPK were highly expressed in activated microglia, and the expression patterns of these genes were consistent with the expression trends of the M1 markers CD32 and CD86. Paeonol decreased the levels of M1 markers (IL1ß, iNOS, CD32, IL6) and increased the levels of M2 markers (IL10, CD206, ARG-1) in LPS-induced microglia. The expression of iNOS, IL1ß, RhoA, and Rock1 was significantly increased in LPS-treated microglia, while paeonol decreased the expression of these proteins. Thermal hyperalgesia occurred after CCI surgery, and paeonol provided relief. In addition, paeonol decreased the levels of IL1ß and IL8 and increased the levels of IL4 and TGF-ß in the serum of CCI rats. Paeonol decreased expression levels of M1 markers and increased expression levels of M2 markers in the spinal cord. Paeonol decreased IBA-1, IL1ß, RhoA, RhoA-GTP, COX2, Rock1, and p-p38MAPK levels in the spinal dorsal horn. CONCLUSION: Paeonol relieves neuropathic pain by modulating microglial M1 and M2 phenotypes through the RhoA/p38 MAPK pathway.

Ferulic acid alleviates sciatica by inhibiting neuroinflammation and promoting nerve repair via the TLR4/NF-κB pathway.

INTRODUCTION: Sciatica causes intense pain. No satisfactory therapeutic drugs exist to treat sciatica. This study aimed to probe the potential mechanism of ferulic acid in sciatica treatment. METHODS: Thirty-two SD rats were randomly divided into 4 groups: sham operation, chronic constriction injury (CCI), mecobalamin, and ferulic acid. We conducted RNA sequencing, behavioral tests, ELISA, PCR, western blotting, and immunofluorescence analysis. TAK-242 and JSH23 were administered to RSC96 and GMI-R1 cells to explore whether ferulic acid can inhibit apoptosis and alleviate inflammation. RESULTS: RNA sequencing showed that TLR4/NF-κB pathway is involved in the mechanism of sciatica. CCI induced cold and mechanical hyperalgesia; destroyed the sciatic nerve structure; increased IL-1ß, IL-6, TNF-α, IL-8, and TGF-ß protein levels and IL-1ß, IL-6, TNF-α, TGF-ß, TLR4, and IBA-1 mRNA levels; and decreased IL-10 and INF-γ protein levels and IL-4 mRNA levels. Immunohistochemistry showed that IBA-1, CD32, IL-1ß, iNOS, nNOS, COX2, and TLR4 expression was increased while S100ß and Arg-1 decreased. CCI increased TLR4, IBA-1, IL-1ß, iNOS, Myd88, p-NF-κB, and p-p38MAPK protein levels. Treatment with mecobalamin and ferulic acid reversed these trends. Lipopolysaccharide (LPS) induced RSC96 cell apoptosis by reducing Bcl-2 and Bcl-xl protein and mRNA levels and increasing Bax and Bad mRNA and IL-1ß, TLR4, Myd88, p-NF-κB, and p-p38MAPK protein levels, while ferulic acid inhibited cell apoptosis by decreasing IL-1ß, TLR4, Myd88, p-NF-κB, and p-p38MAPK levels and increasing Bcl-2 and Bcl-xl levels. In GMI-R1 cells, Ferulic acid attenuated LPS-induced M1 polarization by decreasing the M1 polarization markers IL-1ß, IL-6, iNOS, and CD32 and increasing the M2 polarization markers CD206, IL-4, IL-10 and Arg-1. After LPS treatment, IL-1ß, iNOS, TLR4, Myd88, p-p38MAPK, and p-NF-κB levels were obviously increased, and Arg-1 expression was reduced, while ferulic acid reversed these changes. CONCLUSION: Ferulic acid can promote injured sciatic nerve repair by reducing neuronal cell apoptosis and inflammatory infiltration though the TLR4/NF-κB pathway.

Identification of pyroptosis­related genes in neuropathic pain based on bioinformatics analysis.

Pyroptosis is defined as inflammation-induced programmed cell death. However, gene expression levels related to pyroptosis and their role in neuropathic pain (NP) remain unclear. The present study aimed to develop and validate an NP-predictive signature based on the genes associated with pyroptosis. Gene expression level profiles were downloaded from the Gene Expression Omnibus database. Weighted gene co-expression network analysis was used to identify the pyroptotic genes most highly associated with NP. NP-related pyroptosis gene signature was constructed using multivariate logistic regression. A rat model of neuropathic pain was established through chronic constriction injury to analyse the inflammatory infiltration and myelin damage around the sciatic nerve, and examine the expression levels of macrophage markers S100 calcium-binding protein ß (S100ß) and ionized calcium-binding adapter molecule 1 (Iba-1). Finally, flow cytometry analysis was used to examine the lipopolysaccharide (LPS)-induced cell death ratio of RSC96 cells (Schwann cells), while the expression levels of LPS-induced pyroptosis-related genes in RSC96 cells were measured via reverse transcription-quantitative PCR. The results demonstrated that pyroptosis-related genes (gasdermin D, NLR family pyrin domain containing 3, neuronal apoptosis inhibitory protein and NLR family CARD domain containing 4) were identified to increase the risk of NP. NP-related pyroptosis signatures were constructed based on these four genes. Moreover, the high-risk group had a higher level of macrophage infiltration compared with the low-risk group, as determined by the CIBERSORT algorithm. H&E staining results showed that the myelin structure of the sciatic nerve tissue of chronic constriction injury (CCI) rats was destroyed and inflammatory cells infiltrated around neurons. The results of immunohistochemistry showed that compared with in the sham group, the expression levels of Iba-1 and sS100ß in the sciatic nerve of the CCI group were increased. Furthermore, the expression levels of cell death and pyroptosis-related genes in Schwann cells induced by LPS were increased compared with in the control group. In conclusion, an NP-related pyroptosis gene signature was constructed based on four pyroptosis-related genes and it was found that the expression of pyroptosis-related genes was upregulated in the early steps of the neuroinflammatory process in RSC96 cells.

α-Asarone attenuates chronic sciatica by inhibiting peripheral sensitization and promoting neural repair.

This study explored the therapeutic effect of α-asarone on chronic sciatica. Thirty-two Sprague-Dawley (SD) rats were divided into four groups: the sham group, chronic constriction injury (CCI) group, pregabalin group, and α-asarone group. Hot hyperalgesia was induced after the CCI operation, and α-asarone was found to relieve chronic neuralgia. Furthermore, α-asarone reduced IL1ß, IL6, TNF-α, CRP, and LPS levels and increased IL10 levels in serum. α-Asarone decreased the protein levels of TRPA1, TRPM8, and TRPV1-4 and the mRNA levels of TRPA1, TRPM8, TRPV1-4, IL1ß, and TNF-α in dorsal root ganglion neurons. In the sciatic nerve, α-asarone treatment reduced the number of inflammatory cells and promoted the proliferation of Schwann cells, favouring recovery of the nerve structure. In cellular experiments, LPS induced Schwann cell apoptosis via TLR4/p38MAPK signalling; α-asarone attenuated LPS-induced Schwann cell apoptosis by decreasing TLR4, p-p38MAPK, cleaved-caspase3, and cleaved-caspase7 levels and increasing Bcl-2 and Bcl-xl expression. Overall, these findings suggest that α-asarone relieves chronic sciatica by decreasing the levels of inflammatory factors, inhibiting peripheral sensitization, and favouring the repair of damaged nerves.

Ferulic acid alleviates sciatica by inhibiting peripheral sensitization through the RhoA/p38MAPK signalling pathway.

BACKGROUND: Nonsteroidal anti-inflammatory drugs are used to relieve sciatica, but their effects are not satisfactory. PURPOSE: This study aimed to explore the therapeutic effects of ferulic acid on sciatica. METHODS: Thirty-two SD rats were randomly divided into 4 groups, i.e., sham operation group, chronic constriction injury (CCI) group, mecobalamin group, and ferulic acid group. We conducted behavioural tests, ELISA, PCR, Western blots, and immunofluorescence analysis. Specific inhibitors were used in cell experiments to explore the related mechanisms. RESULTS: Thermal hyperalgesia was induced after CCI operation, and ferulic acid relieved thermal hyperalgesia. In addition, ferulic acid decreased the IL1ß, IL6, TNF-α, and CRP mRNA levels; the IBA-1, iNOS, IL1ß, RhoA, RhoA-GTP, COX2, Rock1, TRPV1, TRPA1, and p-p38MAPK levels in dorsal root ganglion (DRG) neurons; and the LPS, CRP, substance P (SP), and prostaglandin E2 (PGE2) levels in serum, and these levels were higher in the CCI group. In the cell experiments, LPS induced M1 polarization of GMI-R1 cells via the RhoA/Rock pathway. Ferulic acid attenuated LPS-induced M1 polarization by decreasing the levels of M1 polarization markers, including IL1ß, IL6, TNF-α, iNOS, and CD32, and increased M2 polarization by increasing the levels of M2 polarization markers, including CD206 and Arg-1. LPS treatment clearly increased the iNOS, IL1ß, RhoA, Rock1, Rock2 and p-p38 MAPK levels and reduced Arg-1 expression, and ferulic acid reversed these changes. CONCLUSION: Ferulic acid can inhibit peripheral sensitization by reducing the levels of inflammatory factors, TRPA1 and TRPV1 through the RhoA/p38 MAPK pathway to alleviate sciatica.

The combination of Lonicerae Japonicae Flos and Forsythiae Fructus herb-pair alleviated inflammation in liver fibrosis.

Objective: To explore the active components and epigenetic regulation mechanism underlying the anti-inflammatory effects of Lonicerae Japonicae Flos and Forsythiae Fructus herb-pair (LFP) in carbon tetrachloride (CCl4)-induced rat liver fibrosis. Methods: The main active ingredients and disease-related gene targets of LFP were determined using TCMSP and UniProt, and liver fibrosis disease targets were screened in the GeneCards database. A network was constructed with Cytoscape 3.8.0 and the STRING database, and potential protein functions were analyzed using bioinformatics analysis. Based on these analyses, we determined the main active ingredients of LFP and evaluated their effects in a CCl4-induced rat liver fibrosis model. Serum biochemical indices were measured using commercial kits, hepatocyte tissue damage and collagen deposition were evaluated by histopathological studies, and myofibroblast activation and inflammation were detected by reverse transcription-polymerase chain reaction (RT-PCR) and western blotting. High-performance liquid chromatography-mass spectrometry was performed to determine the levels of homocysteine, reduced glutathione, and oxidized glutathione, which are involved in inflammation and oxidative stress. Results: The main active components of LFP were quercetin, kaempferol, and luteolin, and its main targets were α-smooth muscle actin, cyclooxygenase-2, formyl-peptide receptor-2, prostaglandin-endoperoxide synthase 1, nuclear receptor coactivator-2, interleukinß, tumor necrosis factor α, CXC motif chemokine ligand 14, and transforming growth factor ß1. A combination of quercetin, kaempferol, and luteolin alleviated the symptoms of liver fibrosis. Conclusion: The results of this study support the role of LFP in the treatment of liver fibrosis, and reveal that LFP reduces collagen formation, inflammation, and oxidative stress. This study suggests a potential mechanism of action of LFP in the treatment of liver fibrosis.

Identification of pathways and key genes in male late-stage carotid atherosclerosis using bioinformatics analysis.

Late-stage carotid atherosclerosis has a high incidence rate and may lead to various cerebrovascular diseases. The gene expression profile GSE100927 was selected to identify differentially expressed genes (DEGs) in carotid atherosclerosis. Subsequently, protein-protein interaction, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were conducted. Furthermore, experimental verification was performed using human umbilical vein endothelial cells (HUVECs), human aortic vascular smooth muscle cells (HAVSMCs) and Tohoku Hospital Pediatrics-1 (THP-1)-induced macrophages. The groups were as follows: Control group, solvent control group and palmitic acid group. The levels of reactive oxygen species (ROS) in the three cell types were detected by flow cytometry or fluorescence microscopy. Furthermore, apoptosis of HUVECs and HAVSMCs was assessed by flow cytometry and the nuclear Hoechst 33258 staining of THP-1-induced macrophages was performed. Male late-stage carotid atherosclerosis samples, including 10 control samples and 21 atherosclerosis samples, were selected. Pathway enrichment analysis demonstrated that 'Toll-like receptor signaling pathway' was the top pathway associated with the DEGs. MMP7, MMP9, IL1ß, C-C motif chemokine ligand 4 (CCL4), secreted phosphoprotein 1 (SPP1), CCL3 and interferon regulatory factor 5 (IRF5) were selected for experimental verification. Palmitic acid increased the ROS levels and the apoptosis rates of HUVECs and HAVSMCs. However, it did not increase the levels of ROS and did not shrink the nuclei of THP-1-induced macrophages. Furthermore, palmitic acid increased the mRNA levels of IL1ß, CCL4, SPP1, CCL3, IRF5, MMP7 and MMP9 in HUVECs and THP-1-induced macrophages, and increased the mRNA levels of CCL4 and MMP9 in HAVSMCs. In conclusion, IL1ß, CCL3, CCL4, SPP1, IRF5, MMP7 and MMP9 are important markers of late-stage carotid atherosclerosis.

Therapeutic effect of paeoniflorin on chronic constriction injury of the sciatic nerve via the inhibition of Schwann cell apoptosis.

Therapeutic drugs of chronic neuralgia have a high risk of addiction, making it crucial to identify novel drugs for chronic neuralgia. This study aimed to explore the therapeutic effect of paeoniflorin on chronic sciatica via inhibiting Schwann cell apoptosis. 28 SD rats were randomly divided into four groups, including the sham operation group, chronic constriction injury (CCI) group, mecobalamin group, and paeoniflorin group. The therapeutic effect and mechanism of paeoniflorin were evaluated via rat and cell experiments. Mechanical, hot, or cold hyperalgesia was induced in the rats after CCI operation, while paeoniflorin relieved chronic neuralgia. Besides, paeoniflorin decreased the levels of IL1, IL6, TNF-α, CRP, and LPS and increased the level of IL10 in serum. As for the sciatic nerve, the number of inflammatory cells was decreased, and Schwann cells were present after paeoniflorin treatment, and paeoniflorin promoted the recovery of nerve structure. In cell experiments, LPS induced Schwann cell apoptosis via the TLR4/NF-kB pathway. And paeoniflorin attenuated LPS-induced Schwann cell apoptosis by decreasing the levels of TLR4, p-NF-kB, caspase3, cleaved-caspase3, and cleaved-caspase7. Overall, these results suggest that paeoniflorin alleviates chronic sciatica by decreasing inflammatory factor levels and promotes the repair of damaged nerves by reducing Schwann cell apoptosis.

Kaempferol exerts a neuroprotective effect to reduce neuropathic pain through TLR4/NF-ĸB signaling pathway.

Switching microglial polarization from the M1 to M2 phenotype is a promising therapeutic strategy for neuropathic pain (NP). Toll-like receptor 4 (TLR4) is activated by lipopolysaccharide (LPS). Uncontrolled activation of TLR4 has been proven to trigger chronic inflammation. Kaempferol, a dietary flavonoid, is known to have anti-inflammatory properties. This study is aimed to investigate the analgesic and anti-inflammatory effects and the underlying mechanisms of kaempferol, which were explored with an NP model in vivo and LPS-induced injury in microglial BV2 cells in vitro. The levels of proinflammatory cytokines were evaluated. H&E staining and immunohistochemistry were used to assess the sciatic nerve condition after chronic constriction injury surgery. Western blotting and immunofluorescence were used to determine whether TLR4/NF-ĸB signaling pathway plays a major role in kaempferol-mediated alleviation of neuroinflammation. Quantitative real-time polymerase chain reaction and flow cytometry were used to examine the modulator effect of kaempferol on microglial M1/M2 polarization. We found that kaempferol treatment can significantly reduce NP and proinflammatory cytokine production. Kaempferol attenuated the activation of TLR4/NF-κB pathways in LPS-activated BV2 cells. The analgesic effects of kaempferol on NP may be due to inhibition of microglia activation and switching the M1 to M2 phenotype.

Reactive Oxygen Species Are Essential for Vasoconstriction upon Cold Exposure.

PURPOSE: We explored the role of ROS in cold-induced vasoconstriction and corresponding mechanism. METHODS: Three experiments were performed. First, we measured blood flow in human hands before and after cold exposure. Second, 24 mice were randomly divided into 3 groups: 8 mice received saline injection, 8 received subcutaneous Tempol injection, and 8 received intrathecal Tempol injection. After 30 min, we determined blood flow in the skin before and after cold exposure. Finally, we used Tempol, CCG-1423, and Go 6983 to pretreat HAVSMCs and HUVECs for 24 h. Then, cells in the corresponding groups were exposed to cold (6 h, 4°C). After cold exposure, the cytoskeleton was stained. Intracellular Ca2+ and ROS levels were measured by flow cytometry and fluorescence microscopy. We measured protein expression via Western blotting. RESULTS: In the first experiment, after cold exposure, maximum skin blood flow decreased to 118.4 ± 50.97 flux units. Then, Tempol or normal saline pretreatment did not change skin blood flow. Unlike intrathecal Tempol injection, subcutaneous Tempol injection increased skin blood flow after cold exposure. Finally, cold exposure for 6 h shrank the cells, making them narrower, and increased intracellular Ca2+ and ROS levels in HUVECs and HAVSMCs. Tempol reduced cell shrinkage and decreased intracellular Ca2+ levels. In addition, Tempol decreased intracellular ROS levels. Cold exposure increased RhoA, Rock1, p-MLC-2, ET-1, iNOS, and p-PKC expression and decreased eNOS expression. Tempol or CCG-1423 pretreatment decreased RhoA, Rock1, and p-MLC-2 levels in HAVSMCs. Furthermore, Tempol or Go 6983 pretreatment decreased ET-1, iNOS, and p-PKC expression and increased eNOS expression in HUVECs. CONCLUSION: ROS mediate the vasoconstrictor response within the cold-induced vascular response, and ROS in blood vessel tissues rather than nerve fibers are involved in vasoconstriction via the ROS/RhoA/ROCK1 and ROS/PKC/ET-1 pathways in VSMCs and endothelial cells.

Protective effect of 18ß-glycyrrhetinic acid against H2O2-induced injury in Schwann cells based on network pharmacology and experimental validation.

The aim of the present study was to assess the protective effects of 18ß-GA against hydrogen peroxide (H2O2)-induced injury. First, the SMILES annotation for 18ß-GA was used to search PubChem and for reverse molecular docking in Swiss Target Prediction, the Similarity Ensemble Approach Search Server and the TargetNet database to obtain potential targets. Injury-related molecules were obtained from the GeneCards database and the predicted targets of 18ß-GA for injury treatment were selected by Wayne diagram analysis. Subsequently, Kyoto Encyclopedia of Genes and Genomes analysis was performed by WebGestalt. The experimental cells were assorted into control, model, 10 µM SB203580-treated, 5 µM 18ß-GA-treated and 10 µM 18ß-GA-treated groups. Hoechst 33258 staining was performed and intracellular reactive oxygen species (ROS) levels, cell apoptosis, Bcl-xl, Bcl-2, Bad, Bax, cleaved-caspase 3, cleaved-caspase 7, transient receptor potential ankyrin 1 (TRPA1) and transient receptor potential vanilloid 1 (TRPV1) levels, as well as p38 MAPK phosphorylation were measured. The 'Inflammatory mediator regulation of TRP channels' pathway was selected for experimental verification. The results indicated that 10 µM 18ß-GA significantly increased cell viability as compared with the H2O2-treated model group. As suggested by the difference in intracellular ROS fluorescence intensity, 18ß-GA inhibited H2O2-induced ROS production in Schwann cells. Hoechst 33258 staining indicated that 18ß-GA reversed chromatin condensation and the increase in apoptotic nuclei following H2O2 treatment. Furthermore, flow cytometry suggested that 18ß-GA substantially inhibited H2O2-induced apoptosis. Pre-treatment with 18ß-GA obviously reduced Bad, Bax, cleaved-caspase3, cleaved-caspase 7, TRPA1 and TRPV1 levels and p38 MAPK phosphorylation after H2O2 treatment and increased Bcl-2 and Bcl-xl levels. In conclusion, 18ß-GA inhibited Schwann cell injury and apoptosis induced by H2O2 and may be a potential drug to prevent peripheral nerve injury.

Protective effect of paeoniflorin on H2O2 induced Schwann cells injury based on network pharmacology and experimental validation.

This study was to investigate the protective effect of paeoniflorin (PF) on hydrogen peroxide-induced injury. Firstly, "SMILES" of PF was searched in Pubchem and further was used for reverse molecular docking in Swiss Target Prediction database to obtain potential targets. Injury-related molecules were obtained from GeenCards database, and the predicted targets of PF for injury treatment were selected by Wayne diagram. For mechanism analysis, the protein-protein interactions were constructed by String, and the KEGG analysis was conducted in Webgestalt. Then, cell viability and cytotoxicity assay were established by CCK8 assay. Also, the experimental cells were allocated to control, model (200 µmol·L-1 H2O2), SB203580 10 µmol·L-1 (200 µmol·L-1 H2O2+ SB203580 10 µmol·L-1), PF 50 µmol·L-1 (200 µmol·L-1 H2O2+ PF 50 µmol·L-1), and PF 100 µmol·L-1 (200 µmol·L-1 H2O2+ PF 100 µmol·L-1) groups. We measured the intracellular ROS, Hoechst 33258 staining, cell apoptosis, the levels of Bcl-xl, Bcl-2, Caspase-3, Cleaved-caspase3, Cleaved-caspase7, TRPA1, TRPV1, and the phosphorylation expression of p38MAPK. There are 96 potential targets that may be associated with PF for injury treatment. Then, we chose the "Inflammatory mediator regulation of TRP channels" pathway for the experimental verification from the first 10 KEGG pathway. In experimental verification, H2O2 decreased the cell viability moderately (P < 0.05), and 100 µmol·L -1 PF increased the cell viability significantly (P < 0.05). Depending on the difference of intracellular ROS fluorescence intensity, PF inhibited H 2O2-induced reactive oxygen species production in Schwann cells. In Hoechst 33258 staining, PF reversed the condensed chromatin and apoptotic nuclei following H2O2 treatment. Moreover, Flow cytometry results showed that PF could substantially inhibit H2O2 induced apoptosis (P < 0.05). Pretreatment with PF obviously reduced the levels of Caspase3, Cleaved-caspase3, Cleaved-caspase7, TRPA1, TRPV1, and the phosphorylation expression of p38MAPK after H 2O2 treatment (P < 0.05), increased the levels of Bcl-2, and Bcl-xl ( P < 0.05). PF inhibited Schwann cell injury and apoptosis induced by hydrogen peroxide, which mechanism was linked to the inhibition of phosphorylation of p38MAPK.