Panax notoginseng saponin Rl attenuates allergic rhinitis through AMPK/DRP1 mediated mitochondrial fission北大核心CSCD

目的探讨三七皂苷(notoginsenoside R1,PNS-R1)是否通过AMP激活蛋白激酶(AMP-activated protein kinase,AMPK)/线粒体裂变关键蛋白(dynamin-related protein 1,DRP1)介导的线粒体裂变减轻过敏性鼻炎(allergic rhinitis,AR)。方法利用不同剂量PNS-R1治疗卵清蛋白(Ovalbumin,OVA)诱导的AR小鼠,通过观察擦鼻、打喷嚏的过敏症状和鼻组织的HE染色探索PNS-R1在AR中的抑制作用。通过酶联免疫吸附法(ELISA)检测血清IgE水平和鼻灌洗液(nasal lavage fluid,NLF)炎性细胞因子水平,Western blot检测凋亡相关蛋白。在体外,利用IL-13刺激人鼻黏膜上皮细胞(human nasal epithelial cells,HNEpC),观察细胞凋亡、线粒体膜电位、细胞活性氧(reactive oxygen species,ROS)和线粒体ROS(mtROS)生成、AMPK/DRP1,TXNIP/NLRP3炎症小体的表达水平以及DRP1易位情况。结果PNS-R1减轻了AR小鼠的过敏症状,HE染色炎性细胞减少,降低血清OVA特异性IgE水平以及NLF中IL-4、IL-6和IL-8的水平。在体外,PNS-R1上调IL-13刺激后的线粒体膜电位,降低ROS和mtROS生成、减少cleaved-caspase-3、Bax和上调Bcl-2表达,以AMPK依赖性方式下调DRP1磷酸化(Ser 616)和DRP1在线粒体膜上的易位,减少TXNIP/NLRP3表达。结论PNS-R1通过抑制AMPK/DRP1信号轴及随后的TXNIP/NLRP3信号轴保护线粒体的完整性,缓解AR。     

Ca2 +-activated K+ channel-3.1 blocker TRAM-34 alleviates murine allergic rhinitis

The precise pathogenesis of allergic rhinitis (AR) remains unclear and AR is less easily cured. Recent evidence has suggested that calcium-activated K⁺ channel-3.1(KCa3.1) is implicated in the immune response of allergic and inflammatory diseases and TRAM-34 is a selective KCa3.1 blocker. However, little is known about its role in AR. We aimed to investigate the effect of TRAM-34 in a mouse model of AR induced by ovalbumin (OVA). The BALB/c mice were divided into six groups: untreated AR group, 200 μg TRAM-34 treated AR group, 400 μg TRAM-34 treated AR group, 200 μg TRAM-34 treated normal group, 400 μg TRAM-34 treated normal group and untreated normal control group. Histopathological characteristics were assessed by HE staining. KCa3.1 protein expression was investigated by immunohistochemistry and western blotting method, and mRNA expression of KCa3.1, stromal interaction molecule1 (STIM1) and Orai1 in nasal tissues were assessed by real-time PCR. Furthermore, concentrations of OVA-specific IgE, ECP, IL-4, IL-5, IL-17 and IL-1β in nasal lavage fluid (NLF) were analyzed by enzyme-linked immunosorbent assay (ELISA). Results showed that TRAM-34 administration into the nostril attenuated sneezing, nasal rubbing, epithelial cell proliferation, eosinophil infiltration and inhibited nasal mucosa KCa3.1, STIM1 and Orai1 expression in TRAM-34 treated mice compared with untreated AR mice and suppressed inflammatory cytokines in the NLF of TRAM-34 treated groups compared with untreated AR mice. In conclusion, TRAM-34 could effectively alleviate murine allergic rhinitis by suppressing KCa3.1 and leads to reduction of K⁺ efflux and Ca^2 + influx, leading to inflammation reduction and allergic responses attenuation.     

Inhibiting NLRP3 inflammasome with MCC950 ameliorates perioperative neurocognitive disorders,suppressing neuroinflammation in the hippocampus in aged mice

Perioperative neurocognitive disorders (PND) are characterized by deficits in cognitive functions in the elderly following anesthesia and surgery. Effective clinical interventions for preventing this disease are limited. Growing evidence demonstrates that activation of NOD-like receptor protein3 (NLRP3) inflammasome is involved in neurodegenerative diseases. We therefore hypothesized that activation of NLRP3 inflammasome is linked to neuroinflammation and the subsequent cognitive impairments that occurred in an animal model of PND. In this study, 18-month-old C57BL/6 mice were subjected to an exploratory laparotomy under isoflurane anesthesia to mimic clinical human abdominal surgery. For interventional studies, mice received NLRP3 specific inhibitor MCC950 (10 mg/kg) or the vehicle only intraperitoneally. Behavioral studies were performed at 6 and 7 d after surgery using open field and fear conditioning tests, respectively. Interleukin-1β (IL-1β), interleukin-18 (IL-18), tumor necrosis factor-α (TNF-α), ionized calcium-binding adaptor molecule-1 (IBA1) positive cells, glial fibrillary acidic protein (GFAP) positive cells, NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), and cleaved caspase-1 were measured at 3 days post-surgery. Brain-derived neurotrophic factor (BDNF) and postsynaptic density protein 95 (PSD95) were measured at 7 days post-surgery. Our data indicates that surgery-induced cognitive impairments were associated with significant increases in IL-1β, IL-18, TNF-α, NLRP3, ASC, cleaved caspase-1, IBA1-positive cells and GFAP-positive cells, and decreases in BDNF and PSD95 expression in the hippocampus. Notably, administration with MCC950 attenuated inflammatory changes and rescued surgery-induced cognitive impairments. Our study suggests that surgery induces neuroinflammation and cognitive deficits that are partly attributed to the activation of NLRP3 inflammasome in the hippocampus of aged mice.     

α-Mangostin protects lipopolysaccharide-stimulated nucleus pulposus cells against NLRP3 inflammasome-mediated apoptosis via the NF-κB pathway

Intervertebral disc degeneration (IDD) is a common and chronic inflammatory disorder. α-Mangostin exhibits a novel biological function against inflammation in various inflammatory diseases. Here, we aimed to explore the role of α-mangostin in IDD using an in vitro cell model. Human nucleus pulposus cells (NPCs) were exposed to lipopolysaccharide (LPS) to induce inflammatory injury. Cell viability of NPCs was determined by CCK-8 assay. ELISA was performed to examine the production of interleukin (IL)-1β and IL-18. Apoptotic cell death in NPCs was detected by TUNEL staining. The expression levels of apoptotic-associated proteins were detected by western blotting. Nuclear factor-kappa B (NF-κB) activation was examined by determining the expression levels of p-p65, p65, and nuclear p65. Results showed that treatment with α-mangostin improved the viability of LPS-treated NPCs. α-Mangostin treatment also inhibited the LPS-induced increase in expression levels of NLRP3, ASC and pro-caspase-1, as well as the production of IL-1β and IL-18 in NPCs. Moreover, treatment with α-mangostin or NLRP3 inhibitor (MCC950) significantly decreased apoptotic cell death in NPCs, as compared with treatment with LPS. In addition, the expression levels of cleaved caspase-3 and Bax were decreased, while Bcl-2 expression was increased in α-mangostin- or MCC950-treated NPCs. Treatment with α-mangostin also suppressed LPS-induced increase of p-p65/p65 and nuclear p65 levels. Moreover, inhibition of NF-κB by PDTC aggravated the inhibitory effects of α-mangostin on NLRP3 inflammasome activation and apoptosis in LPS-induced NPCs. These findings suggested that α-mangostin exerted a protective effect on NLRP3 inflammasome-mediated apoptosis in LPS-induced NPCs through regulating NF-κB signaling.     

Dexamethasone alleviate allergic airway inflammation in mice by inhibiting the activation of NLRP3 inflammasome

Dexamethasone (DEX) is the mainstay treatment for asthma, which is a common chronic airway inflammation disease. However, the mechanism of DEX resolute symptoms of asthma is not completely clear. Here, we aimed to analyze the effect of DEX on airway inflammation in OVA-induced mice and whether this effect is related to the inhibition of the activation of NLRP3 inflammasome. Female (C57BL/6) mice were used to establish the allergic airway inflammation model by inhalation OVA. The number of inflammatory cells in the bronchi alveolar lavage fluid (BALF) was counted by Swiss-Giemsa staining, and the contents of IL-1β, IL-18, IL-5 and IL-17 were detected by ELISA. The degree of inflammatory cells infiltration and mucous cells proliferation in lung tissue were separately observed by H&E and PAS staining. The proteins expression of NLRP3, pro-caspase-1, caspase-1, IL-1β, IL-6 and IL-17 in lung tissue were detected by Western blotting. We found that DEX significantly inhibited OVA-induced inflammatory cells infiltration, airway mucus secretion and goblet cell proliferation in mice. The total and classified numbers of inflammatory cells and the levels of IL-1β, IL-18, IL-5 and IL-17 in the BALF of the experimental group were significantly lower than those of the model group after DEX treatment. DEX also significantly inhibited the activity of NLRP3 inflammasome and reduced the protein contents of Pro-Caspase-1, Caspase-1, Capase-1/Pro-Caspase-1, IL-1β, IL-6 and IL-17 in lung tissues. Our study suggested that DEX alleviates allergic airway inflammation by inhibiting the activity of NLRP3 inflammasome and the levels of IL-1β and IL-18.     

氟西汀调节TLR4/NF-κB/NLRP3炎症体信号通路改善CUMS大鼠抑郁样行为

目的 基于Toll样受体4(TLR4)/核因子κB(NF-κB)/NOD样受体热蛋白结构域相关蛋白3(NLRP3)炎症体信号通路探究氟西汀对慢性不可预知性轻度应激(CUMS)模型大鼠抑郁样行为的作用。方法 18只SD大鼠随机分为对照组、模型组和氟西汀组。模型组和氟西汀组大鼠随机给予不可预知性轻度刺激11周,制备抑郁症模型。氟西汀组于第7～11周灌胃氟西汀(10 mg·kg^-1·d^-1),其余组大鼠灌胃1 mL生理盐水。干预结束后进行行为学检测,酶联免疫吸附试验检测脑组织中白细胞介素(IL)-1β和IL-18的含量,免疫荧光染色观察海马CA3区和皮质区中NLRP3、凋亡相关斑点样蛋白(ASC)和胱天蛋白酶1(Caspase-1)的表达情况。Western blot测定脑组织TLR4、NF-κB、NLRP3、Caspase-1和活化的Caspase-1(cleaved Caspase-1)蛋白的表达水平。结果 与模型组比较,氟西汀组大鼠在旷场的运动距离及站立次数显著增多,在高架十字迷宫的运动距离增加,且在闭臂的停留时间减少,大鼠脑组织中IL-1β...     

Anti-inflammatory effect of epigallocatechin gallate in a mouse model of ovalbumin-induced allergic rhinitis

Currently, a variety of studies have demonstrated that green tea has anti-allergic properties, and the major polyphenolic compound, epigallocatechin gallate (EGCG), plays a significant role. Some research indicates that EGCG reduces the production and expression of allergy-related substances. Therefore, EGCG has a potential effect of reducing allergic rhinitis (AR). In this study, the effect of EGCG on allergic rhinitis in an ovalbumin (OVA)-induced mouse model was investigated. After administration of EGCG, the number of sneezes and the occurrence of nasal rubbing were significantly decreased, the concentrations of immunoglobulin E (IgE) and histamine were suppressed in AR mouse serum, the levels of interleukin (IL)-1β, IL-4, and IL-6 were reduced in AR mice nasal lavage fluid (NLF), and the nasal mucosa mRNA and protein expression of cyclooxygenase 2 (COX-2), IL-1β, IL-4, and IL-6 were inhibited. The data indicate that EGCG has a beneficial effect of reducing allergic rhinitis.     

Leptin is upregulated in epididymitis and promotes apoptosis and IL-1β production in epididymal epithelial cells by activating the NLRP3 inflammasome

Epididymitis, one of the most common urological disease, is a significant cause of male infertility. Leptin is capable of modulating both reproduction and immune response. We analyzed the serum and seminal plasma levels of leptin in infertile patients with or without chronic epididymitis. Experimental epididymitis models were generated by administrating 200 μg Lipopolysaccharide (LPS) to Sprague-Dawley rats. The expression of leptin in epididymis were detected using qPCR, Western blots 6–72 h after injection, and using immunohistochemistry 72 h after injection. Besides, rat epididymal epithelial cells were isolated as an in vitro model and were treated with leptin (5–40 ng/ml, 6–48 h), LPS (1ug/ml, 6 h), and NLRP3 inflammasome inhibitor MCC950 (10 μM, 2 h). Cell Counting Kits-8 assay and Annexin V/PE assay were used to evaluate cell viability and apoptosis. Quantitive PCR and ELISA assay were used to detected inflammatory cytokines interleukin-1beta (IL-1β) production. Western Blots were used to detect molecular related to cell apoptosis, IL-1β maturation, and NLRP3 inflammasome. We found that patients with chronic epididymitis presented a significantly higher level of seminal plasma leptin and correlated declined sperm progressive motility. Leptin and leptin receptor expression in epididymis was significantly upregulated 24 h after LPS administration both in mRNA and protein level, and highly expressed in the epididymis epithelium 72 h after LPS administration. In epididymal epithelial cells, leptin reduced cell viability and promoted apoptosis in a concentration-dependent manner via cleavage of caspase-9, caspase-3, and PARP. Leptin enhanced the LPS-induced production of IL-1β, which was associated with increased IL-1β maturation and caspase-1 activation. Furthermore, NLRP3 inhibitor MCC950 attenuated the effects of leptin or co-treatment with LPS on NLRP3, ASC expression, IL-1β maturation, and caspase-1 activation, which indicated that leptin promotes IL-1β production via activating the NLRP3 inflammasome. These data suggested that leptin may act as a potential evaluation and treatment target for epididymitis and male subfertility.     

Skullcapflavone II attenuates ovalbumin-induced allergic rhinitis through the blocking of Th2 cytokine production and mast cell histamine release

Allergic rhinitis is a common heterogeneous chronic upper airway disorder and is an IgE-mediated inflammation characterized by one or more nasal symptoms such as sneezing, itching, nasal discharge, rhinorrhea, post nasal drainage and nasal blockage. In the present study, the effects of skullcapflavone II (SCFII) on upper airway inflammation, Th2 cytokines, and NF-κB signaling in an ovalbumin (OVA)-induced allergic rhinitis (AR) murine model in vivo were investigated. OVA-induced AR mice increased nasal symptoms, eosinophils and mast cells infiltration into nasal cavity, OVA-specific IgE/IgG1 and histamine in serum, Th2 cytokines including IL-13 and GATA3, and NF-κB signaling in NALF and lung homogenate. Interestingly, treatment of SCFII reduced the levels of OVA-specific IgE/IgG1 and histamine in serum, of Th2 cytokines and of NF-κB signaling in the NALF and the lung homogenate, and histopathological changes in the nasal tissue and the lung. Also, dexamethasone suppressed such increases. The results of this study suggested that SCFII may ameliorate allergic inflammation of upper airway in AR mice model by blocking the Th2 cytokine production, the NF-κB signal pathway and the mast cell histamine release. Taken together, we suggest that SCFII may be used as a therapeutic agent for patients with Th2-mediated or mast cell-mediated allergic diseases.     

Beneficial effects of chelidonic acid on a model of allergic rhinitis

Chelidonic acid (CA) is known as an inhibitor of the rat brain glutamate decarboxylase. However, the pharmacological effects of CA in allergic reactions have not yet been defined. Here, we show the effects and the mechanism of CA in the ovalbumin (OVA)-sensitized allergic rhinitis (AR) model. CA significantly decreased the number of nasal/ear rubs and increment of IgE levels in the AR mice. The level of interferon-γ was enhanced while the level of IL-4 was reduced on the spleen tissue of the CA-administered AR mice. Expressions of IL-1β and cyclooxygenase-2 were inhibited by CA administration in the nasal mucosa tissues. Infiltration of eosinophils and mast cells was decreased in the CA-administered AR mice. Furthermore, CA decreased the caspase-1 activity in the same nasal mucosa tissue and human mast cell line, HMC-1. Our results indicate that CA may attenuate allergic reaction by inhibition of caspase-1 activity.     

NLRP3 inflammasome is involved in nerve recovery after sciatic nerve injury

The activation of the inflammasome plays an important role in the central nervous system. However, only a few studies have investigated the effects of inflammasome activation in the peripheral nerve, especially in the sciatic nerve, and the mechanism of this activation remains elusive. Moreover, how interleukin-1 beta (IL-1β) is produced after sciatic nerve injury is also unknown. In our study, we aimed to investigate whether the nucleotide-binding oligomerization domain-like pyrin domain containing protein 3 (NLRP3) inflammasome is activated after sciatic nerve injury and to explore its role in sciatic nerve injury. The results of immunoblotting and immunofluorescence microscopy indicate that the NLRP3 inflammasome was activated after sciatic nerve injury in wild-type (WT) mice, as demonstrated by upregulated inflammasome-related components, e.g., NLRP3, procaspase-1 and ASC. Furthermore, upregulated inflammasome-related components cis-cleavage precursor IL-1β (proIL-1β) and precursor interleukin-18 (proIL-18) to IL-1β and IL-18, contributing to the inflammatory response. Consequently, the inflammatory response after sciatic nerve injury in NLRP3 knockout (NLRP3-KO) mice was less severe than that in WT mice. Moreover, NLRP3-KO mice exhibited an increased sciatic functional index (SFI), which was determined by footprint analysis, suggesting that NLRP3 deficiency is beneficial to sciatic nerve recovery after injury. Therefore, our results indicate that NLRP3 is involved in the recovery from sciatic nerve injury and mediates the production of inflammatory factors, such as IL-1β, after sciatic nerve injury.     

PI3K/AKT信号通路在大鼠腹腔感染性脓毒症急性肾损伤中的作用

目的 探究磷脂酰肌醇3-激酶/蛋白激酶B（PI3K/AKT）信号通路在大鼠腹腔感染性脓毒症急性肾损伤（acute kidney injury,AKI）中的作用。方法 使用盲肠结扎穿孔（cecal ligation and puncture,CLP）的方法制备大鼠腹腔感染性脓毒症模型,按照检测时间点（24、48、72 h）分组,于术后各时间点用全自动生化分析仪检测血清肌酐（Cr）、尿素氮（BUN）水平;用实时定量聚合酶链反应（Real-time PCR）检测大鼠肾脏组织PI3K mRNA及AKT mRNA的表达水平,采用蛋白免疫印迹法（Western blot,WB）检测大鼠肾脏组织Nod样受体蛋白3（NLRP3）、凋亡相关斑点样蛋白（ASC）、半胱氨酸天冬氨酸特异性蛋白酶1（Caspase-1）蛋白表达水平,采用酶联免疫吸附法（ELISA）检测血清肿瘤坏死因子-α（TNF-α）、白细胞介素（IL）-1β及IL-18的表达水平。假手术组除不进行盲肠结扎及穿孔外,其余操作与CLP组相同。结果 与假手术组相比,CLP各组大鼠血Cr、BUN水平出现明显升高（P＜0.05）,肾脏组织内PI3K及AKT mRNA 表达水平明显升高（P＜0.01）,且其下游 NLRP3 炎性小体蛋白表达水平明显升高（P＜0.01）,同时血清TNF-α、IL-1β及IL-18水平明显升高（P＜0.01）。结论 PI3K/AKT信号通路在腹腔感染性脓毒症AKI中具有重要作用,其活化诱导下游NLRP3炎性小体活化增加,进而使炎症因子释放增加并加重脓毒症病情。     

Effects of lentivirus-mediated CCR3 RNA interference on the function of mast cells of allergic rhinitis in mice

The CC chemokine receptor 3 (CCR3) expressed by eosinophils, mast cells and Th2 cells is closely related to allergic diseases. The objective of this study was to explore whether silencing of CCR3 with short hairpin RNAs (shRNAs) delivered by a lentiviral vector could impact the function of mast cells in a murine model of allergic rhinitis (AR) in vivo. The murine model of allergic rhinitis (AR) inducing by ovalbumin (OVA) was constructed, and the BALB/c mice were divided into normal control group, AR group, controlshRNA treated group and lentiviral CCR3-shRNA treated group. The recombinant lentivirus vectors which express a short hairpin RNA (shRNA) targeting the CCR3 were dropped into the nasal cavity of OVA-sensitized mice before the challenges. Real-time fluorescence quantitative PCR and western blotting were performed to observe inhibitory effect of CCR3 gene. Nasal symptoms of mice and OVA-specific IgE in each group were assessed. Concentrations of histamine, tryptase and Prostaglandin D2 (PGD2) in bone marrow, peripheral blood and nasal mucosa were analyzed. Furthermore, histological analysis and electron microscopy analysis were applied to detect the histology changes of nasal mucosa and the infiltration of mast cells in nasal mucosa. The results showed that administration of CCR3shRNA could effectively inhibit the expression of the CCR3 gene in bone marrow, peripheral blood and nasal mucosa, which reduced the nasal symptoms, the level of OVA-specific IgE, the inflammatory cells and mast cells infiltration into nasal cavity, and relieved the histopathological changes of nasal mucosa. In addition, intervention of CCR3shRNA could reduce the levels of the histamine, tryptase and PGD2 in bone marrow, peripheral blood and nasal mucosa. These results suggest that inhibition of CCR3 gene expression by shRNAs lentiviral vectors can effectively attenuate migration, infiltration and degranulation of mast cells in local tissues and alleviate the inflammation of allergic rhinitis mice.     

Bamboo salt reduces allergic responses by modulating the caspase-1 activation in an OVA-induced allergic rhinitis mouse model

Bamboo salt (BS) is a specially processed salt according to the traditional recipe using sun-dried salt (SDS) and bamboo in Korea. The present study investigated the effects and mechanism of BS, SDS, NaCl, or mineral mixture (containing zinc, magnesium, and potassium) on ovalbumin (OVA)-induced allergic rhinitis (AR) animal model. The increased number of rubs was inhibited by the oral administration of BS, SDS, NaCl, mineral mixture, or nose inhalation of BS. The increased levels of IgE, histamine, and interleukin (IL)-1β in serum were reduced by BS. The level of interferon-γ was increased, whereas the level of IL-4 was reduced on the spleen tissue of BS-treated mice. In the BS-treated mice, the number of eosinophils and mast cells infiltration increased by OVA-sensitization were also decreased. Protein levels of inflammatory cytokines were reduced by BS or NaCl administration in the nasal mucosa of the AR mice. In addition, BS inhibited caspase-1 activity in the nasal mucosa tissue. In activated human mast cells, BS significantly inhibited the production of IL-1β and thymic stromal lymphopoietin and activation of caspase-1. Our data indicate that BS has anti-allergic and anti-inflammatory effects by regulating of caspase-1 activation in AR mice and in vitro models.     

The interplay between ASMase signaling pathway and NLRP3 in the epithelial to mesenchymal transition of HBE cells induced by silica

Epithelial–mesenchymal transition (EMT) is an important part of pulmonary fibrosis. Our earlier study illustrated that the acid sphingomyelinase (ASMase) pathway plays significant role in silica (SiO₂)-induced transformation of lung fibroblasts into myofibroblasts. The metabolite of ASMase, ceramide (Cer), activates the inflammatory response by activating Nod-like receptor protein 3 (NLRP3) in macrophages, and NLRP3 is also involved in the EMT process. However, whether ASMase and NLRP3 are involved in regulating SiO₂-induced EMT has not been confirmed. In this study, an in vitro model of EMT in human bronchial epithelial (HBE) cells was established by SiO₂ dust staining to investigate the role of ASMase and NLRP3 in EMT and to provide new clues for the molecular mechanism of silicosis. HBE cells were stained with 100 μg/ml SiO₂ dust for 72 h to establish the EMT model. The ASMase inhibitor desipramine decreased the level of S1P and the expression of α-smooth muscle actin (α-SMA) and NLRP3 in SiO₂ dust-stained HBE cells, whereas the expression of E-cadherin (E-cad) increased. The NLRP3 inhibitor MCC950 inhibited the secretion of interleukin-1β (IL-1β) and decreased the expression of NLRP3, Caspase-1, and α-SMA in SiO₂ dust-stained HBE cells, whereas E-cad expression increased and ASMase activity and S1P levels decreased. It was concluded that SiO₂ dust increases the release of the inflammatory factor and induces EMT in HBE cells. Inhibition of ASMase activity or NLRP3 expression reduced the SiO₂ dust-induced cell inflammatory response and slowed the occurrence of EMT in HBE cells. Therefore, NLRP3 and ASMase may interact in SiO₂ dust-induced EMT in HBE cells.     

Scutellarin inhibits caspase-11 activation and pyroptosis in macrophages via regulating PKA signaling

Inflammatory caspase-11 senses and is activated by intracellular lipopolysaccharide (LPS) leading to pyroptosis that has critical role in defensing against bacterial infection, whereas its excess activation under pathogenic circumstances may cause various inflammatory diseases. However, there are few known drugs that can control caspase-11 activation. We report here that scutellarin, a flavonoid from Erigeron breviscapus, acted as an inhibitor for caspase-11 activation in macrophages. Scutellarin dose-dependently inhibited intracellular LPS-induced release of caspase-11p26 (indicative of caspase-11 activation) and generation of N-terminal fragment of gasdermin D (GSDMD-NT), leading to reduced pyroptosis. It also suppressed the activation of non-canonical nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome as evidenced by reduced apoptosis-associated speck-like protein containing a CARD (ASC) speck formation and decreased interleukin-1 beta (IL-1β) and caspase-1p10 secretion, whereas the NLRP3-specific inhibitor MCC950 only inhibited IL-1β and caspase-1p10 release and ASC speck formation but not pyroptosis. Scutellarin also suppressed LPS-induced caspase-11 activation and pyroptosis in RAW 264.7 cells lacking ASC expression. Moreover, scutellarin treatment increased Ser/Thr phosphorylation of caspase-11 at protein kinase A (PKA)-specific sites, and its inhibitory action on caspase-11 activation was largely abrogated by PKA inhibitor H89 or by adenylyl cyclase inhibitor MDL12330A. Collectively, our data indicate that scutellarin inhibited caspase-11 activation and pyroptosis in macrophages at least partly via regulating the PKA signaling pathway.KEY WORDS: Caspase-11, Macrophages, Gasdermin D, Pyroptosis, Scutellarin, PKA signaling     

白藜芦醇调节卵清蛋白诱导的小鼠过敏性鼻炎的作用机制研究

目的探讨白藜芦醇对过敏性鼻炎小鼠的行为学、鼻黏膜组织形态学、血清过敏细胞因子和脾脏中Th2型细胞比例的影响。方法小鼠随机分为NC、AR、白藜芦醇低剂量组(30 mg·kg^-1,RL)、白藜芦醇高剂量组(100 mg·kg^-1,RH)、地塞米松组(Dex),共5组。治疗结束后,记录小鼠挠鼻和打喷嚏次数;HE染色观察鼻黏膜炎细胞浸润;ELISA检测血清中IL-4、IL^-10、IL^-13、IL^-17、IFN-γ和OVA-sIgE的水平;流式细胞术检测脾脏中CD4+GATA3+T细胞比例。结果同AR组比较,RH组小鼠挠鼻和打喷嚏次数显著减少,鼻黏膜炎性细胞浸润降低,血清中IL-4、IL^-13和OVA-sIgE水平均显著下降;RH组中小鼠脾脏中CD4+GATA3+Th2比例显著降低。结论高剂量白藜芦醇治疗后,可以降低卵清蛋白诱导的过敏性鼻炎小鼠脾脏中CD4+IL-4+Th2型T细胞比例,降低血清中OVA-sIgE、IL-4、IL^-13水平,缓解小鼠鼻黏膜炎性细胞浸润,进而减少小鼠的挠鼻和打喷嚏次数,缓解小鼠过敏性鼻炎相关症状。