Correlations of transglutaminase 2 expression in peripheral blood mononuclear cells with relevant inflammatory factors and disease severity in patients with atopic dermatitis / 中华皮肤科杂志

Objective:To determine the expression of transglutaminase 2 (TGM2) in peripheral blood mononuclear cells (PBMCs) from patients with atopic dermatitis (AD), and to analyze its correlation with AD-related inflammatory factors and disease severity.Methods:A total of 29 AD patients and 15 healthy controls were collected from the First Affiliated Hospital of Fujian Medical University from July 2020 to January 2021. Ten milliliters of peripheral blood samples were collected from each subject, so was the clinical information, including age, gender, course of disease, eosinophil counts, basophil counts, total IgE levels, Scoring AD index (SCORAD), etc. PBMCs were isolated by density gradient centrifugation. Fluorescence-based quantitative PCR was performed to determine the mRNA expression of TGM2 and AD-related inflammatory factors (interleukin [IL]-1β, IL-4, IL-6, IL-8, IL-10, IL-13, IL-17, thymic stromal lymphopoietin [TSLP], P2RX7 [purinergic receptor P2X, ligand-gated ion channel, 7], etc.) in PBMCs from 29 AD patients and 15 healthy controls, and flow cytometry to determine TGM2 protein expression on PBMCs. Mann-Whitney U test was used to analyze differences between groups, and Spearman correlation analysis to evaluate the correlation. Results:The relative mRNA expression of TGM2 in PBMCs did not differ between the AD group and control group ( M[ Q1, Q3]: 0.509 [0.325, 0.958] vs. 0.475 [0.328, 1.051], U = 210.50, P = 0.872). Compared with the control group, the AD group showed significantly decreased IL-4 mRNA expression (0.171[0.049, 0.449] vs. 0.824 [0.397, 1.378], P < 0.001), but significantly increased mRNA expression of IL-8 and IL-13 ( P = 0.011, 0.006, respectively). Spearman correlation analysis showed that the mRNA expression level of TGM2 in PBMCs was positively correlated with the mRNA expression levels of IL-4 and P2RX7 in the AD group ( rs = 0.42, 0.40, P = 0.024, 0.034, respectively), while there were no correlations between TGM2 mRNA expression and AD severity-related indicators (all P>0.05), such as age (21[16, 29] years), course of disease (4[1,10] years), eosinophil counts (0.33[0.18, 0.65] × 10 9/L), basophil counts (0.04[0.03, 0.06] × 10 9/L], SCORAD scores (60.5[46.98, 66.13] points), and serum total IgE levels (373 [40, 1 815] IU/ml). The relative protein expression levels of TGM2 on the surface of PBMCs did not differ between the AD group and control group (54.9 [47.6, 62.8] vs. 55.55 [51.5, 60.25], U = 112.00, P = 0.922) ], and no correlations were observed between the protein expression of TGM2 on PBMCs and AD severity-related indicators in the AD group (all P > 0.05) . Conclusion:No significant differences were observed in TGM2 mRNA expression in PBMCs or TGM2 protein expression on the surface of PBMCs between the AD patients and healthy controls, and there were no correlations between the TGM2 mRNA and protein expression and AD severity.

Targeting GATA1 and p2x7r Locus Binding in Spinal Astrocytes Suppresses Chronic Visceral Pain by Promoting DNA Demethylation / 神经科学通报·英文版

Irritable bowel syndrome is a gastrointestinal disorder of unknown etiology characterized by widespread, chronic abdominal pain associated with altered bowel movements. Increasing amounts of evidence indicate that injury and inflammation during the neonatal period have long-term effects on tissue structure and function in the adult that may predispose to gastrointestinal diseases. In this study we aimed to investigate how the epigenetic regulation of DNA demethylation of the p2x7r locus guided by the transcription factor GATA binding protein 1 (GATA1) in spinal astrocytes affects chronic visceral pain in adult rats with neonatal colonic inflammation (NCI). The spinal GATA1 targeting to DNA demethylation of p2x7r locus in these rats was assessed by assessing GATA1 function with luciferase assay, chromatin immunoprecipitation, patch clamp, and interference in vitro and in vivo. In addition, a decoy oligodeoxynucleotide was designed and applied to determine the influence of GATA1 on the DNA methylation of a p2x7r CpG island. We showed that NCI caused the induction of GATA1, Ten-eleven translocation 3 (TET3), and purinergic receptors (P2X7Rs) in astrocytes of the spinal dorsal horn, and demonstrated that inhibiting these molecules markedly increased the pain threshold, inhibited the activation of astrocytes, and decreased the spinal sEPSC frequency. NCI also markedly demethylated the p2x7r locus in a manner dependent on the enhancement of both a GATA1-TET3 physical interaction and GATA1 binding at the p2x7r promoter. Importantly, we showed that demethylation of the p2x7r locus (and the attendant increase in P2X7R expression) was reversed upon knockdown of GATA1 or TET3 expression, and demonstrated that a decoy oligodeoxynucleotide that selectively blocked the GATA1 binding site increased the methylation of a CpG island in the p2x7r promoter. These results demonstrate that chronic visceral pain is mediated synergistically by GATA1 and TET3 via a DNA-demethylation mechanism that controls p2x7r transcription in spinal dorsal horn astrocytes, and provide a potential therapeutic strategy by targeting GATA1 and p2x7r locus binding.

Effect of Yinxing Mihuan Oral Solutionon P2RX7/NLRP3 Signaling Pathway in Depression Model Rats Induced by Isolation Combined with Chronic Unpredictable Mild Stress / 中国实验方剂学杂志

Objective:To explore the antidepressant mechanism of Yinxing Mihuan oral solution （YMO） by investigating its effect on depression model rats. Method:The depression rats were induced by isolation combined with chronic unpredictable mild stress （CUMS） and then randomly divided into model group， fluoxetine group （10 mg·kg^-1） and high-dose （618 mg·kg^-1） and low-dose （309 mg·kg^-1） YMO groups. A blank control group was also set up and ten rats were included in each group. Modeling lasted for 21 consecutive days， and rats were administered the 8th day after stimulation at a dose of 10 mL·kg^-1 for 14 days， except those in the blank control and model groups which were given distilled water. Afterward， the sucrose preference test， open field test， tail suspension test were carried out. The pathological changes of hippocampus in depression rats were observed after hematoxylin-eosin （HE） staining. The content of interleukin-1<italic>β </italic>（IL-1<italic>β</italic>）， interleukin-6 （IL-6） and tumor necrosis factor-<italic>α </italic>（TNF-<italic>α</italic>） in the hippocampus of rats in each group and the expression of NOD-like receptor 3 （NLRP3） and other proteins in its related activation signaling pathways were detected with multi-factor detection （Luminex） and Western blot. Result:After 14 days of continuous administration， compared with the blank control group， the model group witnessed significantly reduced sugar water consumption rate and the times of rearing and significantly prolonged cumulative time of immobility during tail suspension （<italic>P</italic><0.05， <italic>P</italic><0.01）. Compared with the model group， the fluoxetine group and the high-dose YMO group saw increases in the times of rearing， times of crossing and sugar water consumption rate and a significant decrease in the cumulative time of immobility during tail suspension （<italic>P</italic><0.05， <italic>P</italic><0.01）. The results of HE staining showed that the neurons in the hippocampus of rats in the high-dose YMO group were arranged in order and slightly loosened， without obvious microglia infiltration observed. The levels of IL-1<italic>β</italic>， IL-6 and TNF-<italic>α</italic> in the hippocampus of the model group increased significantly as compared with the blank control group （<italic>P</italic><0.05， <italic>P</italic><0.01）， and their content in the high-dose YMO group was significantly lowered in the comparison with the model group （<italic>P</italic><0.05， <italic>P</italic><0.01）. Molecular biology experiments demonstrated that compared with the results of blank group， the expression of purinergic receptor P2X7 （P2RX7）， NLRP3， apoptosis-associated speck-like protein （ASC）， Caspase-1 and IL-1<italic>β</italic> remarkably increased in the model group （<italic>P</italic><0.05， <italic>P</italic><0.01）. Additionally， the expression of P2RX7， NLRP3， ASC， Caspase-1 and IL-1<italic>β </italic>was significantly inhibited in the fluoxetine group and the high-dose YMO group compared with the model group （<italic>P</italic><0.05， <italic>P</italic><0.01）. Conclusion:YMO can improve the depression-like behaviors of rats induced by isolation combined with CUMS， and its mechanism of action is related to the regulation of the P2RX7/NLRP3 signaling pathway.

Electroacupuncture at "Jiaji" (EX-B2) induced down-regulation of OX-42 and P2X4 in lumbar spinal cord contributes to its analgesic after-effect in rats with chronic constriction injury / 针刺研究

OBJECTIVE: To investigate the effect of electroacupuncture (EA) at "Jiaji" (EX-B2) at different time points on the expression of OX-42 (a monoclonal antibody with specific expression of complement receptor-3 in spinal microglial cells) and purinergic receptor P2X4 (P2X4) in rats with chronic constriction injury (CCI) of the sciatic nerve, as well as the possible after-effect mechanism of EA analgesia in neuropathic pain. METHODS: Sprague-Dawley rats were randomly divided into blank group, model group, immediately after EA group, 0.5-hour after EA group, 1-hour after EA group, 2-hour after EA group, 4-hour after EA group, 12-hour after EA group, and 24-hour after EA group, with 6 rats in each group. The rats in the model group and the EA groups were used to establish a model of CCI-induced neuropathic pain, and those in the immediately after EA group and the 0.5, 1, 2, 4, 12 and 24 hours after EA groups were treated with EA at bilateral L3 and L5 "Jiaji" points for 20 min after 7 d of modeling. Samples were collected immediately and at 0.5, 1, 2, 4, 12, and 24 hours after EA, and for the rats in the blank group and the model group, samples were collected after fixation the rats for 20 min. Heat pain threshold was observed before and after intervention, and immunohistochemistry was used to measure the protein expression of OX-42 and P2X4 in the spinal cord lumbar enlargement. RESULTS: After 7 days of modeling (before intervention), compared with the blank group, the heat pain threshold had a significant reduction in the model group and the EA groups (P<0.01). Compared with the model group after intervention, the immediately after EA group and the 0.5, 1 and 2 hours after EA groups had a significant increase in heat pain threshold (P<0.05). Compared with the model group, immediately after EA, the 0.5, 1 and 2 hours after EA groups had a significant reduction in the protein expression of OX-42 (P<0.01), and immediately after EA, the 0.5 and 1 hour after EA groups had a significant reduction in the protein expression of P2X4 (P<0.01). CONCLUSION: EA at "Jiaji" points can significantly increase heat pain threshold and down-regulate the protein expression of OX-42 and P2X4 in the spinal cord of CCI rats. The analgesic effect can last for 2 h.

Dexmedetomidine Attenuates Neuropathic Pain by Inhibiting P2X7R Expression and ERK Phosphorylation in Rats

α2-Adrenoceptor agonists attenuate hypersensitivity under neuropathic conditions. However, the mechanisms underlying this attenuation remain largely unknown. In the present study, we explored the potential roles of purinergic receptor 7 (P2X7R)/extracellular signal-regulated kinase (ERK) signaling in the anti-nociceptive effect of dexmedetomidine in a rat model of neuropathic pain induced by chronic constriction injury (CCI) of the sciatic nerve. An animal model of CCI was adopted to mimic the clinical neuropathic pain state. Behavioral hypersensitivity to mechanical and thermal stimuli was determined by von Frey filament and Hargreaves' tests, and the spinal P2X7R expression level and ERK phosphorylation were analyzed using western blot analysis and immunohistochemistry. In parallel with the development of mechanical and thermal hyperalgesia, a significant increase in P2X7R expression was noted in the ipsilateral spinal cord on day 7 after CCI. Intrathecal administration of dexmedetomidine (2.5 µg) for 3 days not only attenuated neuropathic pain but also inhibited the CCI-induced P2X7R upregulation and ERK phosphorylation. Intrathecal dexmedetomidine administration did not produce obvious effects on locomotor function. The present study demonstrated that dexmedetomidine attenuates the neuropathic pain induced by CCI of the sciatic nerve in rats by inhibiting spinal P2X7R expression and ERK phosphorylation, indicating the potential therapeutic implications of dexmedetomidine administration for the treatment of neuropathic pain.

Nitric oxide modulates ATP-evoked currents in mouse Leydig cells

Testosterone synthesis within Leydig cells is a calcium-dependent process. Intracellular calcium levels are regulated by different processes including ATP-activated P2X purinergic receptors, T-type Ca2+ channels modulated by the luteinizing hormone, and intracellular calcium storages recruited by a calcium-induced calcium release mechanism. On the other hand, nitric oxide (NO) is reported to have an inhibitory role in testosterone production. Based on these observations, we investigated the interaction between the purinergic and nitrergic systems in Leydig cells of adult mice. For this purpose, we recorded ATP-evoked currents in isolated Leydig cells using the whole cell patch clamp technique after treatment with L-NAME (300 μM and 1 mM), L-arginine (10, 100, 300, and 500 μM), ODQ (300 μM), and 8-Br-cGMP (100 μM). Our results show that NO produced by Leydig cells in basal conditions is insufficient to change the ATP-evoked currents and that extra NO provided by adding 300 μM L-arginine positively modulates the current through a mechanism involving the NO/cGMP signaling pathway. Thus, we report an interaction between the nitrergic and purinergic systems in Leydig cells and suggest that Ca2+ entry via the purinergic receptors can be regulated by NO.

Research progress in interactions between neuron and satellite glial cells / 中国药理学通报

Recent studies suggest that glial cells play an impor-tant role in nervous system. Like astrocytes in the central nervous system,satellite glial cells( SGCs) also participate in the physio-logical and pathological processes of the peripheral nervous sys-tem. SGCs affect neuronal functions through neuro-glial interac-tions. In this review,we summarize the current understanding of how SGCs affect the function of neurons.

The clinical significance purinergic receptor P2X ligand-gated ion channel 7, purinergic receptor and its expression on peripheral blood mononuclear cell surface in patients with new-onset systemic lupus erythematosus / 中华风湿病学杂志

Objective To analyze the expression of purinergic receptor P2X ligand-gated ion channel 7 (P2X7R) on different cells and peripheral blood mononuclear cell (PBMC) and to investigate its correlation with inflammatory cytokines in patients with SLE.Methods Flow cytometry was used to detect surface expression of P2X7R on lymphocytes,CD4+ cells,and CD19+ cell in 29 SLE patients and 28 healthy human controls to compare the difference between the SLE patients and the controls in P2X7R expression.Enzyme linked immunosorbent assay (ELISA) was performed to detect P2X7R-related serum cytokines interleukin (IL)-1β,IL-6,tumor necrosis factor (TNF)-α level.T test,Wilcoxon rank sum test,Spearman's correlation analysis were used for statitical analysis.Results ① SLE patients had significantly higher expression of P2X7R on CD4+,CD8+ lymphocytes compared to controls [CD4+ cells∶ 2.21(3.55) vs 0.89(1.15),Z=-1.527,P=0.015； CD19+ cells∶ 11.53(20.01) vs 6.66 (6.27),Z=-2.091,P=0.037]； ② The levels of three cytokines in patients with SLE were significantly higher than those in control.The positive relationship between P2X7R expression in lymphocytes with the serum IL-6 level was found in SLE patients (r=0.449,P=0.015)；③ Patients with arthritis showed significantly higher expression of P2X7R on lym-phocytes compared to patients without arthritis (Z=-2.772,P=0.006).The expression of P2X7R on lymphocytes and CD19+ cell was significantly positively correlated with the SLEDAI score.Positive correlation with anti-β2GP Ⅰ in lymphocyteswas also found.Conclusion P2X7R may mediate the release of inflammatory cytokines involved in the pathogenesis of SLE,and may participate the development of arthritis,lupus nephritis and NPSLE in SLE patients.

Functional Expression of P2Y Receptors in WERI-Rb1 Retinoblastoma Cells

P2Y receptors are metabotropic G-protein-coupled receptors, which are involved in many important biologic functions in the central nervous system including retina. Subtypes of P2Y receptors in retinal tissue vary according to the species and the cell types. We examined the molecular and pharmacologic profiles of P2Y purinoceptors in retinoblastoma cell, which has not been identified yet. To achieve this goal, we used Ca2+ imaging technique and western blot analysis in WERI-Rb-1 cell, a human retinoblastoma cell line. ATP (10 microM) elicited strong but transient [Ca2+]i increase in a concentration-dependent manner from more than 80% of the WERI-Rb-1 cells (n=46). Orders of potency of P2Y agonists in evoking [Ca2+]i transients were 2MeS-ATP>ATP>>UTP=alphabeta-MeATP, which was compatible with the subclass of P2Y1 receptor. The [Ca2+]i transients evoked by applications of 2MeS-ATP and/or ATP were also profoundly suppressed in the presence of P2Y1 selective blocker (MRS 2179; 30 microM). P2Y1 receptor expression in WERI-Rb-1 cells was also identified by using western blot. Taken together, P2Y1 receptor is mainly expressed in a retinoblastoma cell, which elicits Ca2+ release from internal Ca2+ storage sites via the phospholipase C-mediated pathway. P2Y1 receptor activation in retinoblastoma cell could be a useful model to investigate the role of purinergic [Ca2+]i signaling in neural tissue as well as to find a novel therapeutic target to this lethal cancer.

Octyl Gallate Inhibits ATP-induced Intracellular Calcium Increase in PC12 Cells by Inhibiting Multiple Pathways

Phenolic compounds affect intracellular free Ca2+ concentration ([Ca2+]i) signaling. The study examined whether the simple phenolic compound octyl gallate affects ATP-induced Ca2+ signaling in PC12 cells using fura-2-based digital Ca2+ imaging and whole-cell patch clamping. Treatment with ATP (100 micrometer) for 90 s induced increases in [Ca2+]i in PC12 cells. Pretreatment with octyl gallate (100 nM to 20 micrometer) for 10 min inhibited the ATP-induced [Ca2+]i response in a concentration-dependent manner (IC50=2.84 micrometer). Treatment with octyl gallate (3 micrometer) for 10 min significantly inhibited the ATP-induced response following the removal of extracellular Ca2+ with nominally Ca2+-free HEPES HBSS or depletion of intracellular Ca2+ stores with thapsigargin (1 micrometer). Treatment for 10 min with the L-type Ca2+ channel antagonist nimodipine (1 micrometer) significantly inhibited the ATP-induced [Ca2+]i increase, and treatment with octyl gallate further inhibited the ATP-induced response. Treatment with octyl gallate significantly inhibited the [Ca2+]i increase induced by 50 mM KCl. Pretreatment with protein kinase C inhibitors staurosporin (100 nM) and GF109203X (300 nM), or the tyrosine kinase inhibitor genistein (50 micrometer) did not significantly affect the inhibitory effects of octyl gallate on the ATP-induced response. Treatment with octyl gallate markedly inhibited the ATP-induced currents. Therefore, we conclude that octyl gallate inhibits ATP-induced [Ca2+]i increase in PC12 cells by inhibiting both non-selective P2X receptor-mediated influx of Ca2+ from extracellular space and P2Y receptor-induced release of Ca2+ from intracellular stores in protein kinase-independent manner. In addition, octyl gallate inhibits the ATP-induced Ca2+ responses by inhibiting the secondary activation of voltage-gated Ca2+ channels.

Distributions of purinergic P2X_3 receptor immunoreactive afferent fibers in the rat pharyngeal mucosa / 解剖学报

Objective To study the distribution of purinergic P2X_3 receptor immunoreactive afferent fibers in the rat pharyngeal mucosa and provide morphological evidence for exploring the role of ATP in the signal transduction of sensory stimuli. Methods Twelve adult Wistar rats were used and immunofluorescenthistochemical double-labeling technique combined laser confocal scanning microscope was applied in the present study. Results 1.P2X_3 immunoreactive fibers were observed on sections from all parts of pharyngeal mucosa. Two types of positive fibers were found. One was free nerve fibers covered with many varicosities. Another one ramified in mucosa and showed complex arborization endings. Nerve plexus in mucosa were formed by P2X_3 immunoreactive fiber ramifications. 2.Most calcitonin gene-related peptide (CGRP) positive fibers intermingled with P2X_3 immunoreactive fiber arborizations. A few P2X_3 immunoreactive fibers were covered with many varicosities co-localized with CGRP. 3.In petrosal ganglion, most neurons were stained with P2X_3 or CGRP immunoreactivity and small number of P2X_3 immunoreactive neurons co-stained with CGRP. Conclusion These results indicated that the different types of afferent fibers in rat pharyngeal mucosa expressed purinergic P2X_3 receptor immunoreactivity and ATP might be related to nociceptive or physiological signals transduction in rat pharyngeal mucosa.