Saikosaponin D mitigate pilocarpine-induced astrocyte injury by regulating the NLRP3/caspase-1 signaling pathway.

Studies have shown that saikosaponin D (SSD) has favorable neurotherapeutic effects. Therefore, the objective of this study was to explore the efficacy and possible molecular mechanisms of SSD on pilocarpine (PP)-induced astrocyte injury. Primary astrocytes were isolated from juvenile rats and identified using immunofluorescence. The cells were treated with PP and/or SSD for 6 h and 12 h, respectively, followed by measurement of their viability through 3-(4,5-dimethylthiazol)-2,5-diphenyl-tetrazolium bromide (MTT) assay. Next, quantitative real-time polymerase chain reaction (qRT-PCR) was used to measure the expression levels of Glial fibrillary acidic protein (GFAP), C3, S100 calcium binding protein A10 (S100a10), pentraxin 3 (Ptx3), toll-like receptor 4 (TLR4), and RAG in astrocytes after different treatments. Enzyme-linked immunosorbent assay and biochemical tests were utilized to evaluate the level of inflammatory factors [interleukin (IL)-1ß, IL-6, and tumor necrosis factor alpha (TNF-α)] secreted by cells and the content of oxidative stress-related factors (malondialdehyde [MDA] and glutathione [GSH]) or enzyme activity (catalase [CAT] and glutathione peroxidase [GPX]) in cells. The JC-1 mitochondrial membrane potential (MMP) fluorescence probe was used to measure the MMP in astrocytes. Additionally, western blot was applied to test the expression of proteins related to the nod-like receptor protein 3 (NLRP3)/caspase-1 signaling pathway. PP treatment (1 mM) induced cell injury by significantly reducing the viability of astrocytes and expression of cellular markers. SSD treatment (4 µM) had no toxicity to astrocytes. Besides, SSD (4 µM) treatment could significantly up-regulate the cell viability and marker expression of PP-induced astrocytes. Furthermore, SSD could be employed to inhibit inflammation (reduce IL-1ß, IL-6, and TNF-α levels) and oxidative stress (decrease MDA level, elevate GSH level, the activity of CAT and GPX), and ameliorate mitochondrial dysfunction (upregulate JC-1 ratio) in PP-induced astrocytes. Moreover, further mechanism exploration revealed that SSD treatment significantly reduced the activity of the NLRP3/caspase-1 signaling pathway activated by PP induction. SSD increased cell viability, inhibited inflammation and oxidative stress response, and ameliorated mitochondrial dysfunction in PP-induced astrocyte injury model, thus playing a neuroprotective role. The mechanism of SSD may be related to the inhibition of the NLRP3/caspase-1 inflammasome.

Role of NLRP3 Inflammasome in IgA Nephropathy and Chinese Medicine Intervention： A Review / 中国实验方剂学杂志

IgA nephropathy is recognized as the most common primary glomerular disease， with up to 20%-40% of patients developing end-stage kidney disease within 20 years of onset. The deposition of IgA1-containing immune complexes targeting glycosylation defects in the mesangial region and the subsequent inflammation caused by T lymphocyte activation are considered as the main causes of IgA nephropathy， and innate immunity is also involved in the pathogenesis. Nucleotide-binding oligomerization domain （NOD）-like receptor protein 3 （NLRP3） is a newly discovered pattern recognition receptor expressed in renal intrinsic cells such as renal tubular epithelial cells， mesangial cells， and podocytes. Activated by external stimuli， NLRP3 can form NLRP3 inflammasomes with apoptosis-associated speck-like protein containing a caspase recruitment domain （ASC）. The NLRP3 inflammasome can activate cysteine aspartate-specific protease-1 （Caspase-1）， causing the maturation and release of interleukin-18 （IL-18） and interleukin-1β （IL-1β） involved in inflammation. Increasing evidence has suggested that NLRP3 inflammasomes are involved in the pathogenesis and progression of IgA nephropathy and associated with the damage of renal intrinsic cells such as podocytes， mesangial cells， endothelial cells， and renal tubular epithelial cells. Chinese medicine can regulate inflammatory cytokines and their signaling pathways by acting on NLRP3 inflammasomes and related molecules， exerting therapeutic effects on IgA nephropathy. This article introduces the role of NLRP3 inflammasomes in IgA nephropathy and reviews the clinical and experimental research progress of Chinese medicine intervention in IgA nephropathy via NLRP3 inflammasomes， aiming to provide a reference for further research and application of Chinese medicine intervention in the NLRP3 inflammasome as a new therapeutic target.

Wenyang Jieyu Prescription Regulates Hippocampal Neural Plasticity in Depressed Mice via NLRP3/Caspase-1/IL-1β Pathway / 中国实验方剂学杂志

ObjectiveTo explore the effects of Wenyang Jieyu prescription （WJP） on neuroinflammation and synaptic plasticity in the mouse model of depression induced by maternal separation combined with restraint stress. MethodThe mice on postnatal day 0 （PD0） were randomized into a control group and a modeling group. Maternal separation combined with restraint stress was employed to establish the mouse model of depression. After the removal of female mice， the modeled mice were randomized into model， Wenyang prescription （5.85 g·kg-1）， Jieyu prescription （12.03 g·kg-1）， WJP （16.71 g·kg-1）， and fluoxetine （2.6 mg·kg-1） groups on the weaning day （PD21）， with 15 mice in each group. The mice were administrated with corresponding drugs mixed with the diet from PD21 to PD111. The sucrose preference test， open field test， O-maze test， and novel object recognition test were then carried out to evaluate the depression state， memory， and learning ability of the mice. Immunohistochemistry （IHC） was employed to observe the ionized calcium-binding adapter molecule-1 （Iba-1） in hippocampal microglia. High performance liquid chromatography （HPLC） was employed to measure the content of noradrenaline （NE） and epinephrine （E） in the hippocampus. Enzyme-linked immunosorbent assay （ELISA） was employed to determine the content of interleukin （IL）-18 and IL-1β in the hippocampus. Western blot was employed to determine the protein levels of NOD-like receptor protein 3 （NLRP3）， apoptosis-associated speck-like protein containing a CARD （ASC）， cysteine aspartate-specific protease-1 （Caspase-1）， IL-1β， synaptophysin （Syn）， and postsynaptic density 95 （PSD95）. ResultCompared with control group， the model group showed decreased sucrose preference rate， time spent in central zone within 5 min， total movement distance， time spent in the open arm， and cognition index （P<0.05， P<0.01）. The microglia in the model group presented amoeba-like appearance， the Iba1 increased. Moreover， the model group showed decreased content of NE and E （P<0.01）， elevated levels of IL-1β and IL-18 （P<0.01）， down-regulated protein levels of PSD95 and Syn （P<0.05， P<0.01）， and up-regulated protein levels of NLRP3， ASC， Caspase-1， and IL-1β （P<0.05， P<0.01）. Compared with model group， WJP and fluoxetine increased the sucrose preference rate， time spent in central zone within 5 min， total movement distance， time spent in the open arm， and cognition index （P<0.05， P<0.01）. They recovered the microglia and the Iba1 decreased. Moreover， the drugs increased the content of NE and E （P<0.05， P<0.01）， lowered the levels of IL-1β and IL-18 （P<0.01）， up-regulated the protein levels of PSD95 and Syn （P<0.01）， down-regulated the protein levels of NLRP3， ASC， Caspase-1， and IL-1β （P<0.05， P<0.01）. ConclusionWJP can treat the depressive behavior induced by maternal separation combined with restraint stress in mice， with the performance outperforming Wenyang prescription and Jieyu prescription. It may alleviate the neuroinflammation induced by microglia and improve the synaptic plasticity by regulating the NLRP3 pathway and increasing neurotransmitters in the hippocampus.

[Acacetin protects rats from cerebral ischemia-reperfusion injury by regulating TLR4/NLRP3 signaling pathway].

This study aims to investigate the mechanism of acacetin in protecting rats from cerebral ischemia-reperfusion injury via the Toll-like receptor 4(TLR4)/NOD-like receptor protein 3(NLRP3) signaling pathway. Wistar rats were randomized into sham, model, low-and high-dose acacetin, and nimodipine groups, with 10 rats in each group. The rat model of middle cerebral artery occlusion(MCAO) was established with the improved suture method in other groups except the sham group. The neurological deficit score and cerebral infarction volume of each group were evaluated 24 h after modeling. Enzyme-linked immunosorbent assay(ELISA) was employed to measure the levels of interleukin-1ß(IL-1ß), IL-6, tumor necrosis factor-α(TNF-α), malondialdehyde(MDA), supe-roxide dismutase(SOD), and glutathione(GSH). Western blot was employed to determine the expression levels of B-cell lymphonoma-2(Bcl-2), Bcl-2-associated X protein(Bax), and TLR4/NLRP3 signaling pathway-related proteins(TLR4, p-NF-κB/NF-κB, NLRP3, pro-caspase-1, cleaved caspase-1, pro-IL-1ß, and cleaved IL-1ß) in the rat brain tissue. Hematoxylin-eosin(HE) staining was employed to reveal the histopathological changes in the ischemic area. Compared with the sham group, the modeling of MCAO increased the neurological deficit score and cerebral infarction volume, elevated the IL-1ß, IL-6, TNF-α, and MDA levels and lowered the SOD and GSH levels in the brain tissue(P<0.05). Compared with the MCAO model group, low-and high-dose acacetin and nimodipine decreased the neurological deficit score and cerebral infarction volume, lowered the IL-1ß, IL-6, TNF-α, and MDA levels and elevated the SOD and GSH levels in the brain tissue(P<0.05). Compared with the sham group, the model group showed up-regulated protein levels of Bax, TLR4, p-NF-κB/NF-κB, NLRP3, pro-caspase-1, cleaved caspase-1, pro-IL-1ß, and cleaved IL-1ß and down-regulated protein level of Bcl-2 in the brain tissue(P<0.05). Compared with the MCAO model group, the acacetin and nimodipine groups showed down-regulated protein levels of Bax, TLR4, p-NF-κB/NF-κB, NLRP3, pro-caspase-1, cleaved caspase-1, pro-IL-1ß, and cleaved IL-1ß and up-regulated protein level of Bcl-2 in the brain tissue(P<0.05). In conclusion, acacetin regulates the TLR4/NLRP3 signaling pathway to inhibit neuroinflammatory response and oxidative stress, thus exerting the protective effect on cerebral ischemia-reperfusion injury in rats.

[Effect of acupuncture on HIF-1α/NLRP3 inflammatory signaling pathway in the rats with cerebral ischemia-reperfusion injury].

OBJECTIVE: To observe the effects of Xingnao Kaiqiao (regaining consciousness and opening orifices) acupuncture therapy on the expression of hypoxia-inducible factor 1α (HIF-1α) and Nod-like receptor protein 3 (NLRP3) in cerebral ischemia-reperfusion rats, and to explore the mechanism of acupuncture against cerebral ischemia-reperfusion injury. METHODS: Seventy-two male SD rats were randomly divided into a sham-operation group, a model group, an acupuncture group and a non-point acupuncture group, with 18 rats in each one. Using modified Longa thread embolization method, the rat model of acute focal cerebral ischemia was prepared; and after 2 h ischemia, the reperfusion was performed to prepared the model of cerebral ischemia-reperfusion. Immediately after reperfusion, Xingnao Kaiqiao acupuncture method was applied to bilateral "Neiguan" (PC 6) and "Shuigou" (GV 26) in the acupuncture group, while in the non-point acupuncture group, acupuncture was delivered at non-points and all of the needles were retained for 30 min in these two groups. The samples were collected 24 h after reperfusion in the rats of each group. Zea-Longa neurological deficit score was used to evaluate the degree of cerebral neurological impairment, TTC staining was adopted to observe the volume percentage of cerebral infarction, HE staining was provided to observe the morphological changes of brain, and Western blot was applied for detecting the expression of HIF-1α and NLRP3 proteins in the cerebral cortex on the right side. RESULTS: Compared with the sham-operation group, neurological deficit score and volume percentage of cerebral infarction were increased in the model group (P<0.01), and HIF-1α and NLRP3 protein expression was elevated (P<0.01). Compared with the model group, neurological deficit score and volume percentage of cerebral infarction were decreased (P<0.01), and HIF-1α and NLRP3 protein expression was lower (P<0.01) in the acupuncture group. There was no significant difference in above indexes in the non-point acupuncture group compared with the model group (P>0.05). Compared with the sham-operation group, the brain tissue of the rats in the model group and the non-point acupuncture group was loose and edema, and the nuclei were shriveled. The brain tissue morphology in the acupuncture group was similar to that of the sham-operation group. CONCLUSION: Acupuncture can alleviate cerebral ischemia-reperfusion injury, and its mechanism may be related to the regulation of HIF-1α/NLRP3 signaling pathway to attenuate inflammatory response.

Corrigendum: Role of NLRP3 inflammasome in rheumatoid arthritis.

[This corrects the article DOI: 10.3389/fimmu.2022.931690.].

Blocking CXC Motif Chemokine Ligand 2 Ameliorates Diabetic Peripheral Neuropathy via Inhibiting Apoptosis and NLRP3 Inflammasome Activation.

Evidence suggests that CXC motif chemokines are involved in neuronal injury and inflammatory processes. Bioinformatics analysis by using data from the Gene Expression Omnibus (GEO) database was performed and identified CXC motif chemokine ligands (CXCLs) as associated with diabetic peripheral neuropathy (DPN). The present study focused on CXC motif chemokine ligand 2 (CXCL2), and the role and potential mechanisms of CXCL2 in DPN were investigated. The DPN rat model was generated by streptozotocin (STZ) injection in vivo, and high-glucose (HG)-stimulated Schwann cell RSC96 was considered a cell model of DPN in vitro. Neuropathic symptoms of DPN were explored by neurological tests and histological examinations. DPN rats showed a decreased level of motor nerve conduction velocity (MNCV) along with typical histological changes. CXCL2 expression was significantly increased in STZ-induced DPN rat sciatic nerve and HG-induced RSC96 cells. Functionally, CXCL2 knockdown inhibited cell apoptosis and inflammation activation under diabetic conditions in vitro and in vivo. CXCL2 knockdown increased cell viability in HG-treated RSC96 cells and reduced apoptosis concerning the decreased expression of cleaved Caspase 3/9. In addition, CXCL2 knockdown protected against NOD-like receptor protein 3 (NLRP3) inflammasome activation and reduced levels of pro-inflammatory cytokines, interleukin (IL)-1ß and IL-18. The repressive effects of CXCL2 knockdown on inflammasome activation under HG conditions were significantly abolished by treatment of the NLRP3 activator nigericin. In conclusion, these results indicated that CXCL2 knockdown exhibited amelioration of hyperglycemia-induced DPN by inhibiting cell apoptosis and NLRP3 inflammasome activation, suggesting that targeting CXCL2 might be a potential strategy for DPN treatment.

Yang-Gan-Jiang-Mei formula alleviates non-alcoholic steatohepatitis by inhibiting NLRP3 inflammasome through mitophagy.

As an effective formula of traditional Chinese medicine, Yang-Gan-Jiang-Mei (YGJM) formula exhibited a unique advantage in ameliorating liver injury and hepatic steatosis of non-alcoholic steatohepatitis (NASH). Nevertheless, the related pharmacological mechanism needs to be elucidated. This study aimed to explore the molecular mechanism of YGJM formula on mitophagy mediated by PINK1/parkin signaling pathway and NOD-like receptor protein 3 (NLRP3) inflammasome in NASH. High-fat-diet rats and HepG2 cells induced by free fatty acid were used as NASH models in vivo and in vitro. Liver pathology and serum indicator embodying liver function (aspartate transferase, alanine transferase, triglyceride, and total cholesterol) were applied to evaluate the extent of hepatic damage and lipid accumulation. Besides, transmission electron microscopy, JC-1 and 2',7'-dichlorofluorescein diacetate were utilized to observe hepatic mitochondrial morphology, as well as cellular mitochondrial membrane potential and reactive oxygen species level. Additionally, expression of PINK1/parkin-mediated mitophagy and NLRP3 inflammasome was detected to elucidate the underlying mechanism of YGJM formula by immunohistochemistry, immunofluorescence, RT-PCR (reverse transcription-polymerase chain reaction) and Western blot. The manifestations of pathology and biochemical detection confirmed the efficacy of YGJM formula in relieving hepatic damage and lipid deposition. Simultaneously, YGJM formula could obviously improve mitochondrial function. In addition, YGJM formula exhibited the promotion of PINK1/parkin-mediated mitophagy, which could perturb NLRP3 inflammasome activation, and as a result, the hepatocyte inflammation was also suppressed both in vitro and in vivo. Our preliminary results indicate that YGJM formula can ameliorate NASH mechanistically by interfering with PINK1/parkin-mediated mitophagy and NLRP3 inflammasome to exert anti-inflammation ability and promote mitochondrial function restoration.

Human placental extract regulates polarization of macrophages via IRGM/NLRP3 in allergic rhinitis.

Allergic rhinitis (AR) is globally prevalent and its pathogenesis remains unclear. Alternative activation of macrophages is suggested in AR and thought to be involved in natural immunoregulatory processes in AR. Aberrant activation of Nod-like receptor protein 3 (NLRP3) inflammasome is linked with AR. Human placenta extract (HPE) is widely used in clinics due to its multiple therapeutic potential carried by diverse bioactive molecules in it. We aim to investigate the effect of HPE on AR and the possible underlying mechanism. Ovalbumin (OVA)-induced AR rat model was set up and treated by HPE or cetirizine. General manifestation of AR was evaluated along with the histological and biochemical analysis performed on rat nasal mucosa. A proteomic analysis was performed on AR rat mucosa. Mouse alveolar macrophages (MH-S cells) were cultured under OVA stimulation to investigate the regulation of macrophages polarization. The morphological changes and the expression of NLRP3 inflammasome and immunity-related GTPase M (IRGM) in nasal mucosa as well as in MH-S cells were evaluated respectively. The results of our study showed the general manifestation of AR along with the histological changes in nasal mucosa of AR rats were improved by HPE. HPE suppresses NLRP3 inflammasome and the decline of IRGM in AR rats and MH-S cells. HPE regulates macrophage polarization through IRGM/NLRP3. We demonstrated that HPE had protection for AR and the protection is achieved partly through suppressing M1 while promoting M2, the process which is mediated by IRGM via inhibiting NLRP3 inflammasome in AR.

PANoptosis-like cell death in ischemia/reperfusion injury of retinal neurons.

PANoptosis is a newly identified type of regulated cell death that consists of pyroptosis, apoptosis, and necroptosis, which simultaneously occur during the pathophysiological process of infectious and inflammatory diseases. Although our previous literature mining study suggested that PANoptosis might occur in neuronal ischemia/reperfusion injury, little experimental research has been reported on the existence of PANoptosis. In this study, we used in vivo and in vitro retinal neuronal models of ischemia/reperfusion injury to investigate whether PANoptosis-like cell death (simultaneous occurrence of pyroptosis, apoptosis, and necroptosis) exists in retinal neuronal ischemia/reperfusion injury. Our results showed that ischemia/reperfusion injury induced changes in morphological features and protein levels that indicate PANoptosis-like cell death in retinal neurons both in vitro and in vivo. Ischemia/reperfusion injury also significantly upregulated caspase-1, caspase-8, and NLRP3 expression, which are important components of the PANoptosome. These results indicate the existence of PANoptosis-like cell death in ischemia/reperfusion injury of retinal neurons and provide preliminary experimental evidence for future study of this new type of regulated cell death.

Traditional Chinese Medicine Intervenes in Atherosclerosis by Regulating TLR/NLRP3 Pathway via TRPV1/TRPA1 / 中国实验方剂学杂志

Atherosclerosis is a chronic inflammatory disease caused by lipid accumulation and vascular endothelial dysfunction. The Toll-like receptor （TLR）/nuclear transcription factor-κB （NF-κB） pathway and the NOD-like receptor protein 3 （NLRP3） inflammasome pathway play a proinflammatory role， while the transient receptor potential vanilloid subtype 1 （TRPV1） and transient receptor potential ankyrin 1 （TRPA1） play a protective role in the occurrence of atherosclerosis. We reviewed the relevant studies published in the last 10 years. The results showed that activation of TRPV1/TRPA1 could activate endothelial-type nitric oxide synthase （eNOS） and inhibit the generation of reactive oxygen species （ROS） and cholesterol crystal （CC） to modulate the TLR/NF-κB and NLRP3 inflammasome pathways， thereby inhibiting TLR/NLRP3-mediated inflammatory response. A variety of compound prescriptions and active components of Chinese medicinal materials can activate TRPV1/TRPA1 or its downstream pathway to regulate the TLR/NLRP3 pathway in atherosclerosis. This paper introduces the mechanisms of compound prescriptions and active components of Chinese medicinal materials in regulating the TLR/NLRP3 pathway via TRPV1/TRPA1 in atherosclerosis. This review provides new ideas for the research on the interactions between Chinese medicines in the treatment of atherosclerosis and provides a new strategy for the clinical treatment of atherosclerosis with traditional Chinese medicine.

Mechanism of Dendrobium huoshanense Polysaccharide Against Neuroinflammation in Parkinson's Disease Model： Based on NLRP3 Inflammasome / 中国实验方剂学杂志

ObjectiveTo explore the mechanism of Dendrobium huoshanense polysaccharide （DHP） against inflammatory damage of neurons in Parkinson's disease （PD） model. MethodSH-SY5Y cells were randomized into blank group， model group， and DHP group. The survival rate of cells was measured by thiazole blue（MTT） assay， and the levels of lactate dehydrogenase （LDH）， reactive oxygen species （ROS）， malondialdehyde （MDA）， and superoxide dismutase （SOD） were measured by colorimetric analysis. BV-2 microglia were classified into blank group， model group， DHP group， and MCC950 group （positive control group）， and enzyme-linked immunosorbent assay （ELISA） was applied to detect the levels of tumor necrosis factor-α （TNF-α）， interleukin-1β （IL-1β）， and interleukin-18 （IL-18）. The expression of NOD-like receptor protein 3 （NLRP3）， adaptor protein apoptosis-associated dot protein （ASC）， cysteine aspartic protease-1 （Caspase-1）， and IL-1β was measured by Western blot. A total of 50 C57BL/6 mice were randomized into blank group， model group， DHP low-dose （100 mg·kg-1） group， DHP equivalent-dose （350 mg·kg-1） group， and MCC950 group （positive control group）， 10 mice in each group. The motor balance and coordination of C57BL/6 mice were observed by beam walking test， tail suspension test and rotarod test. The levels of Iba-1 and tyrosine hydroxylase （TH） were detected by immunofluorescence staining. The damage of dopaminergic neurons in the substantia nigra was detected by FJB staining. The levels of inflammatory factors such as IL-1β， IL-18， and TNF-α in mouse midbrain tissues were detected by ELISA and the protein levels of NLRP3， ASC， Caspase-1， and IL-1β protein were measured by Western blot. ResultCompared with the blank group， the SH-SY5Y model group showed decreased cell survival， increased levels of LDH， ROS， and MDA （P<0.05）， and decreased levels of SOD （P<0.05）. Compared with the model group， the DHP group demonstrated increased cell survival， decreased levels of LDH， ROS， and MDA （P<0.01）， and increased level of SOD （P<0.01）. Compared with the blank group， BV-2 model group had high levels of IL-1β， IL-18， and TNF-α （P<0.05） and high protein expression of NLRP3， Caspase-1， IL-1β， and ASC （P<0.05）. Compared with the model group， DHP and MCC950 groups demonstrated low levels of IL-1β， IL-18， and TNF-α （P<0.01） and low protein expression of NLRP3， Caspase-1， IL-1β， and ASC （P<0.01）. Compared with the blank group， the C57BL/6 model group displayed long time to pass the balance wood （P<0.05）， short time spent on the rod in the rotarod test （P<0.05）， high levels of IL-1β， IL-18， and TNF-α （P<0.05） and expression of Iba-1 in the midbrain substantia nigra （P<0.05）， low TH expression （P<0.05）， more positive neurons in the FJB staining （P<0.05）， and high expression of NLRP3， Caspase-1， ASC， and IL-1β proteins （P < 0.05）. Compared with the model group， the mice in the DHP and MCC950 groups had short time to pass the balance beam （P<0.01）， long time spent on the rod （P<0.01）， low levels of IL-1β， IL-18， and TNF-α （P<0.01）， low Iba-1 expression in midbrain substantia nigra （P<0.01）， high TH expression （P<0.01）， and small number of positive neurons in the midbrain substantia nigra （P<0.01）. The expression of NLRP3， ASC， and IL-1β proteins was lower in the MCC950 group （P<0.01）， and the expression of NLRP3， ASC， Caspase-1 and IL-1β proteins was lower in the DHP equivalent-dose group （P<0.01） than in the model group. ConclusionDHP has anti-oxidative stress effect. It regulates the expression of NLRP3 inflammasome and inhibits the overactivation of microglia， thereby alleviating the neuroinflammatory injury in PD and exerting the neuroprotective effect.

Effect of acupuncture on HIF-1α/NLRP3 inflammatory signaling pathway in the rats with cerebral ischemia-reperfusion injury / 中国针灸

OBJECTIVE@#To observe the effects of Xingnao Kaiqiao (regaining consciousness and opening orifices) acupuncture therapy on the expression of hypoxia-inducible factor 1α (HIF-1α) and Nod-like receptor protein 3 (NLRP3) in cerebral ischemia-reperfusion rats, and to explore the mechanism of acupuncture against cerebral ischemia-reperfusion injury.@*METHODS@#Seventy-two male SD rats were randomly divided into a sham-operation group, a model group, an acupuncture group and a non-point acupuncture group, with 18 rats in each one. Using modified Longa thread embolization method, the rat model of acute focal cerebral ischemia was prepared; and after 2 h ischemia, the reperfusion was performed to prepared the model of cerebral ischemia-reperfusion. Immediately after reperfusion, Xingnao Kaiqiao acupuncture method was applied to bilateral "Neiguan" (PC 6) and "Shuigou" (GV 26) in the acupuncture group, while in the non-point acupuncture group, acupuncture was delivered at non-points and all of the needles were retained for 30 min in these two groups. The samples were collected 24 h after reperfusion in the rats of each group. Zea-Longa neurological deficit score was used to evaluate the degree of cerebral neurological impairment, TTC staining was adopted to observe the volume percentage of cerebral infarction, HE staining was provided to observe the morphological changes of brain, and Western blot was applied for detecting the expression of HIF-1α and NLRP3 proteins in the cerebral cortex on the right side.@*RESULTS@#Compared with the sham-operation group, neurological deficit score and volume percentage of cerebral infarction were increased in the model group (P<0.01), and HIF-1α and NLRP3 protein expression was elevated (P<0.01). Compared with the model group, neurological deficit score and volume percentage of cerebral infarction were decreased (P<0.01), and HIF-1α and NLRP3 protein expression was lower (P<0.01) in the acupuncture group. There was no significant difference in above indexes in the non-point acupuncture group compared with the model group (P>0.05). Compared with the sham-operation group, the brain tissue of the rats in the model group and the non-point acupuncture group was loose and edema, and the nuclei were shriveled. The brain tissue morphology in the acupuncture group was similar to that of the sham-operation group.@*CONCLUSION@#Acupuncture can alleviate cerebral ischemia-reperfusion injury, and its mechanism may be related to the regulation of HIF-1α/NLRP3 signaling pathway to attenuate inflammatory response.

Jiedu Huoxue Prescription Regulates NF-κB/NLRP3/Caspase-1 to Promote Vascular Reendothelialization in Rat Model of Injured Thoracic Aorta / 中国实验方剂学杂志

ObjectiveTo investigate the mechanism of Jiedu Huoxue prescription in promoting the reendothelialization of injured vessels by regulating the nuclear factor （NF）-κB/NOD-like receptor protein 3 （NLRP3）/cysteine-aspartic acid protease （Caspase）-1-mediated pyroptosis. MethodA rat model of injured thoracic aorta was established by balloon injury， and 36 rats were assigned into shame surgery， model， low-， medium-， and high-dose Jiedu Huoxue prescription， and atorvastatin calcium tablet groups. The injured aortic segment was collected 28 days after surgery. Hematoxylin-eosin （HE） staining and Evans blue staining were conducted to reveal the changes of vascular structural morphology and the reendothelialization of blood vessels， respectively. The enzyme-linked immunosorbent assay （ELISA） was employed to determine the levels of tumor necrosis factor-α （TNF-α）， intercellular adhesion molecule-1 （ICAM-1）， interleukin （IL）-1β， and nitric oxide （NO） in the serum. Western blotting was employed to determine the expression of endothelial nitric oxide synthase （eNOS）， NF-κB p65， phospho-NF-κB p65 （p-NF-κB p65）， NLRP3， and Caspase-1 in the vascular tissue. ResultThe model group showed thickened endovascular membrane， proliferation and disarrangement of smooth muscle cells of the artery wall， obvious inflammatory cell infiltration， and narrowed luminal area. Jiedu Huoxue prescription and atorvastatin calcium tablets mitigated the pathological changes of the thoracic aorta in different degrees. After balloon injury， the endothelial coverage rate of the model group decreased significantly， while Jiedu Huoxue prescription and atorvastatin calcium tablets increased the reendothelialization rate （P<0.05）. Compared with the shame surgery group， the model group showed elevated levels of TNF-α， ICAM-1， and IL-1β （P<0.01） and lowered NO level （P<0.01） in the serum. In addition， the model group presented down-regulated protein level of eNOS （P<0.01） and up-regulated phosphorylation of pyroptosis-associated proteins NLPR3， Caspase-1， and NF-κB p65 in the vascular tissue （P<0.05， P<0.01）. Compared with the model group， Jiedu Huoxue prescription and atorvastatin calcium tablets lowered TNF-α， ICAM-1， and IL-1β levels （P<0.05， P<0.01） and elevated the NO level in the serum （P<0.05， P<0.01）. Moreover， the drugs up-regulated the expression of eNOS （P<0.01） and down-regulated the expression of NLRP3， Caspase-1， and NF-κB p65 （P<0.05， P<0.01） in the vascular tissue. ConclusionJiedu Huoxue prescription can promote the reendothelialization and inhibit the intimal hyperplasia of vessels after balloon injury by regulating the NF-κB/NLRP3/Caspase-1 pathway to inhibit pyroptosis and reduce endothelial inflammatory injury.

Huanglian Jiedutang Treats Acute Gouty Arthritis via NLRP3 Inflammasome and TLR4/NF-κB Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo observe the effect of Huanglian Jiedutang on the inflammatory injury in the mouse model of acute gouty arthritis （AGA） and to explore the mechanism of Huanglian Jiedutang in treating AGA. MethodForty male C57BL/6J mice were randomized into blank， model， colchicine （0.83 mg·kg-1）， and Huanglian Jiedutang （5 g·kg-1） groups. The mouse model of AGA was established by injecting monosodium urate （MSU） crystals into the ankle joint. The swelling degree of the right ankle joint of each mouse was measured every day for 7 days， and the pathological changes of the ankle joint were detected by hematoxylin-eosin （HE） staining after 7 days. The other 40 C57BL/6J mice were grouped as above. After 18 hours of modeling， the right ankle joint was collected， and real-time polymerase chain reaction was employed to measure the mRNA levels of interleukin （IL）-1β， tumor necrosis factor （TNF）-α， IL-6， NOD-like receptor protein 3 （NLRP3）， apoptosis-associated speck-like protein containing a CARD （ASC）， and Caspase-1. The expression levels of IL-1β， TNF-α， and IL-6 were measured by the enzyme-linked immunosorbent assay. Western blot was employed to determine the protein levels of NLRP3 inflammasome， Toll-like receptor 4 （TLR4）， and nuclear factor-κB （NF-κB）. ResultCompared with the blank group， the model group showed swelling right ankle joint （P<0.01）， obvious foreign body granuloma in the ankle joint with inflammatory cell infiltration. After the treatment with Huanglian Jiedutang， the ankle joint swelling was relieved （P<0.05， P<0.01）， and the size of foreign body granuloma was reduced. Compared with the blank group， the model group showed up-regulated mRNA levels of IL-1β， TNF-α， and IL-6 in the ankle joint tissue （P<0.01）， up-regulated mRNA levels of NLRP3 and Caspase-1 in the NLRP3 inflammasome （P<0.05， P<0.01）， and up-regulated protein levels of NLRP3， Caspase-1， TLR4， and NF-κB （P<0.05， P<0.01）. Huanglian Jiedutang down-regulated the mRNA levels of IL-1β， TNF-α， IL-6， NLRP3， and Caspase-1 （P<0.05， P<0.01） and the protein levels of IL-1β， TNF-α， IL-6， NLRP3， Caspase-1， TLR4， and NF-κB （P<0.05 or P<0.01）. ConclusionInjecting MSU crystal resulted in local inflammatory injury of the joints in the mouse model of AGA. The treatment with Huanglian Jiedutang may alleviate the inflammatory injury by regulating the NLRP3 inflammasome and TLR4/NF-κB signaling pathway.

Mechanism of Shenqi Yiliu Prescription Combined with Cisplatin on H22 Liver Cancer-bearing Mice Based on NLRP3/Caspase-1/GSDMD Pyroptosis Pathway / 中国实验方剂学杂志

ObjectiveTo explore the anti-tumor effect and mechanism of Shenqi Yiliu prescription in the intervention of pyroptosis. MethodTen male BALB/c mice were randomly selected and assigned to the blank group. The remaining 40 mice underwent the induction of the liver cancer xenograft model. After 5 days of modeling， 40 surviving mice were randomly divided into model group， cisplatin group ［2.5×10-3 g·kg-1·（3 d）-1］， Shenqi Yiliu prescription group （27 g·kg-1·d-1）， and a combination group （Shenqi Yiliu prescription group + cisplatin）. The mice in the blank group and the model group were treated with an equal volume of normal saline for 10 days. The general conditions of mice in each group were observed. After the intervention， the tumor weight of the mice was weighed and the tumor inhibition rate was calculated. Hematoxylin-eosin （HE） staining was used to observe the pathological changes in tumor tissues. The levels of mouse liver function indicators， including alanine aminotransferase （ALT） and aspartate aminotransferase （AST） were detected. The TdT-mediated dUTP-biotin nick end labeling （TUNEL） assay was used to detect DNA damage in mouse tumor tissue cells. Immunohistochemistry （IHC）， immunofluorescence （IF）， and Western blot were used to detect the protein expression levels of NOD-like receptor protein 3 （NLRP3）， cysteinyl aspartate-specific protease-1 （Caspase-1）， and gasdermin D （GSDMD） in tumor tissues. The levels of interleukin-1β （IL-1β） and interleukin-18 （IL-18） in tumor tissues were detected by enzyme-linked immunosorbent assay （ELISA）. ResultCompared with the mice in the blank group， those in the model group were in a poor mental state， sleepy， and lazy， and their fur color was dull， with increased levels of serum ALT and AST in liver function tests （P<0.01）. Compared with the model group， the groups with drug intervention showed improved mental state， inhibited tumor growth to varying degrees， and decreased tumor weight， and the tumor inhibition rate in the combination group was the highest （P<0.01）. HE staining showed that the pathological and morphological lesions of the tumor tissues in the model group were significant， while those in all groups with drug intervention were improved to a certain extent. The karyolysis and nuclear rupture in the Shenqi Yiliu prescription group and the combination group were more significant. In the liver function test， the serum ALT and AST levels of mice in the Shenqi Yiliu prescription group and the combination group decreased （P<0.01）， and the inflammatory factors IL-1β and IL-18 in each group with drug intervention decreased （P<0.05， P<0.01）. Among them， the declining trend of IL-1β and IL-18 in the Shenqi Yiliu prescription group was the most significant （P<0.01）. TUNEL staining showed that the positive TUNEL staining in each group with drug intervention decreased after intervention （P<0.05， P<0.01）， especially the cisplatin group and Shenqi Yiliu prescription group （P<0.01）. Western blot， IHC， and IF found that the protein expression levels of NLRP3， Caspase-1， and GSDMD in each group with drug intervention decreased （P<0.05， P<0.01）. Compared with the mice in the cisplatin group， those in the Shenqi Yiliu prescription group and the combination group had better mental state and regular tumor morphology， and the tumor weight of the mice in the combination group decreased （P<0.05）. The levels of ALT and AST in the Shenqi Yiliu prescription group decreased （P<0.05）， and the levels of IL-1β and IL-18 in the Shenqi Yiliu prescription group and the combination group decreased （P<0.05， P<0.01）， especially in the combination group （P<0.01）. The results of IHC showed that the expression of GSDMD protein in the tumor tissues of mice in the combination group was reduced （P<0.01）. IF detection showed that the expression of NLRP3 in the tumor tissues of the Shenqi Yiliu prescription group was reduced （P<0.01）. The results of Western blot showed that the expression level of NLRP3 protein in the Shenqi Yiliu prescription group and the combination group decreased （P<0.01）， and the expression level of Caspase-1 protein in the combination group decreased （P<0.01）. The decrease in GSDMD protein expression was not significant， and the difference was not statistically significant. ConclusionShenqi Yiliu prescription combined with cisplatin has an obvious anti-tumor effect， which may be achieved by down-regulating the NLRP3/Caspase-1/GSDMD inflammatory pyroptosis pathway to inhibit cell pyroptosis， and relieve the inflammatory response in mice with liver cancer.

Relationship Between NLRP3 Inflammasome and Diabetic Cardiomyopathy and Intervention Effect of Traditional Chinese Medicine： A Review / 中国实验方剂学杂志

Diabetic cardiomyopathy （DCM） is one of the complications of diabetes. It refers to a specific type of idiopathic cardiomyopathy that occurs in individuals with diabetes， distinct from other cardiovascular diseases such as coronary heart disease， valvular heart disease， or congenital heart disease. It has also been identified as one of the leading causes of death in diabetic patients for many years. Research has shown that the pathogenesis of DCM is closely associated with insulin resistance， activation of various inflammatory responses， increased oxidative stress， impaired coronary microcirculation， and accumulation of advanced glycation end products （AGEs）. Among various inflammatory responses， the activation of the NOD-like receptor protein 3 （NLRP3） inflammasome can induce the secretion of a large amount of pro-inflammatory cytokines through the cascade reaction of inflammation， subsequently mediating cellular pyroptosis and promoting myocardial damage. Currently， extensive experimental studies on traditional Chinese medicine （TCM） have been conducted in China and abroad based on the significant role of the NLRP3 inflammasome in the prevention and treatment of DCM. These studies have demonstrated that Chinese medicinal extracts， such as Astragalus polysaccharide and ginsenoside Rb1， single drugs like Coriolus and Cordyceps， and Chinese medicinal formulas like Didangtang and modified Taohe Chengqitang， as well as acupuncture and TCM exercise therapy， can regulate the relevant pathways of the NLRP3 inflammasome to inhibit its assembly or activation， reduce inflammatory responses， inhibit myocardial remodeling in DCM， and improve cardiac function. This article reviewed the relationship between the NLRP3 inflammasome and DCM， as well as the research progress on TCM in exerting anti-inflammatory effects in this field， aiming to provide new insights for the development of therapeutic approaches for DCM.

Regulation of Pyroptosis in Gastric Cancer by Traditional Chinese Medicine： A Review / 中国实验方剂学杂志

Pyroptosis， a new type of inflammatory programmed cell death， is different from apoptosis， necrosis， cytosis， ferroptosis， and autophagy. Pyroptosis is dependent on the activation of cysteine aspartate-specific protease （Caspase）， which cleaves key mediator proteins to form pores in the cell membrane and induces the maturation and release of the proinflammatory cytokines interleukin-1β and interleukin-18 into the extracellular environment， resulting in a cascade of inflammatory reactions. Gastric cancer as a malignant tumor of the digestive tract is refractory and has poor prognosis， and the chemoradiotherapy of this disease may lead to a variety of complications. At present， the pathogenesis of gastric cancer remains unclear. Studies have proved that pyroptosis is associated with the occurrence and development of gastric cancer， which has attracted wide attention. Pyroptosis is a double-edged sword for gastric cancer. On the one hand， it can release the contents of proinflammatory cells to amplify or maintain inflammation and induce the "inflammation-cancer" transformation of cells. On the other hand， pyroptosis can enhance the sensitivity of drugs for chemotherapy to improve the therapeutic effect and survival. In recent years， the anti-tumor mechanism of traditional Chinese medicine （TCM） has become a research hotspot as TCM has demonstrated significant effects in clinical application. Therefore， the regulation of pyroptosis by TCM may be a new direction for the treatment of gastric cancer in the future. Based on the available studies， this paper introduces the roles of pyroptosis-associated key proteins in the occurrence and development of gastric cancer. Furthermore， this paper summarizes the effects of TCM prescriptions and active ingredients on alleviating gastric mucosal damage， reducing the incidence of gastric cancer， and preventing tumor metastasis and recurrence by mediating pyroptosis pathways， aiming to provide new ideas for deciphering the mechanism of pyroptosis and exploring the TCM treatment of gastric cancer in the future.

Therapeutic Effect and Mechanism of Regulating Inflammasome NLRP3 Signaling Pathway of Lycopi Herba Extract on Chronic Prostatitis / 中国实验方剂学杂志

ObjectiveTo investigate the therapeutic effect of Lycopi Herba extract on chronic prostatitis （CNP） and explore the underlying action mechanism via the inflammasome NOD-like receptor protein 3 （NLRP3） pathway. MethodNormal human prostatic stromal cells， namely WPMY-1 were induced by lipopolysaccharide （LPS） of 5 mg·L-1， and the effects of Lycopi Herba extract of 3.125， 6.25， 12.5， 25， 50， and 100 mg·L-1 on interleukin-6 （IL-6） level released by LPS-induced WPMY-1 cells were detected by enzyme-linked immunosorbent assay （ELISA）. The half-maximal inhibitory concentration （IC50） was calculated. The expression of key proteins in the NLRP3 pathway was detected by western blot after Lycopi Herba extract of 50， 75， and 100 mg·L-1 was administered to WPMY-1 cells. The rat model of CNP was established by injecting carrageenan salt solution into the abdominal lobe of the prostate gland. Hematoxylin-eosin （HE） staining was used to observe the histopathological changes in the prostate gland in rats. The prostate organ index of rats was measured. The level of 5α-dihydrotestosterone （5α-DHT） in serum， as well as the levels of IL-6， tumor necrosis factor-α （TNF-α）， transforming growth factor-β1 （TGF-β1）， cyclooxygenase-2 （COX-2）， prostaglandin E2 （PGE2）， and inducible nitric oxide synthase （iNOS） in prostate tissue were detected by ELISA. The key protein expressions of COX-2， TGF-β1， and NLRP3 pathway in prostate tissue were detected by Western blot. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to detect the expressions of COX-2， IL-1β， TGF-β1， and TNF-α mRNA in prostate tissue. ResultCompared with the normal group， the level of IL-6 and the protein expression levels of NLRP3， ASC， Caspase-1， and IL-1β of WPMY-1 cells in the model group were increased （P<0.05， P<0.01）. Compared with the model group， Lycopi Herba extract could inhibit the levels of IL-6 （P<0.01） released by LPS-induced WPMY-1 cells， with IC50 of 38.26 mg·L-1. The protein expression levels of NLRP3， ASC， and IL-1β in the low-， medium-， and high-dose groups of Lycopi Herba extract were significantly down-regulated （P<0.05， P<0.01）. The expression levels of Caspase-1 protein in medium- and high-dose groups of Lycopi Herba extract were significantly down-regulated （P<0.05， P<0.01）. Compared with the sham operation group， the prostate organ index of rats in the model group was significantly increased （P<0.01）， a large number of inflammatory cells were infiltrated in the prostate tissue， and the histopathological score was significantly increased （P<0.05）； the levels of 5α-DHT in serum， the levels of TNF-α， PGE2， IL-6， TGF-β1， NOS2/iNOS， and COX-2 in prostate tissue， and expression levels of COX-2， IL-1β， and TGF-β1 were significantly increased （P<0.05， P<0.01）. The mRNA expression levels of COX-2， TGF-β1， NLRP3， Caspase-1， ASC， and IL-1β in prostate tissue were significantly up-regulated （P<0.05， P<0.01）. Compared with model group， the low and high doses of Lycopi Herba extract could alleviate the pathological changes in prostate tissue induced by carrageenan， significantly reduce the level of 5α-DHT in serum， levels of TNF-α， PGE2， TGF-β1， and iNOS in prostate tissue （P<0.05， P<0.01）， and mRNA expression levels of COX-2， IL-1β， and TGF-β1 （P<0.05， P<0.01）. The protein expression levels of COX-2， Caspase-1， ASC， and NLRP3 in prostate tissue were significantly down-regulated （P<0.05， P<0.01）. The prostate organ index of the low-dose group of Lycopi Herba extract was significantly decreased （P<0.01）. The level of COX-2 in prostate tissue of the high-dose group of Lycopi Herba extract was significantly decreased， and the protein expression levels of TGF-β1 and IL-1β were significantly down-regulated （P<0.05）. ConclusionLycopi Herba extract has an obvious therapeutic effect on CNP and may reduce inflammation by inhibiting the activation of the inflammasome NLRP3 signaling pathway.

Alcohol Extract of Angelicae Pubescentis Radix Treats Gouty Arthritis Induced by MSU via NLRP3/ASC/Caspase-1 Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo explore the efficacy and mechanism of the alcohol extract DH50 of Angelicae Pubescentis Radix in treating gouty arthritis induced by monosodium urate （MSU） crystals in vivo and in vitro. MethodFifty male SD rats were randomly assigned into five groups （n=10）： a normal group， a model group， a dexamethasone （DXMS， 0.07 mg·kg-1） group， and low- （DH50-D， 9 mg·kg-1） and high-dose （DH50-G， 18 mg·kg-1） DH50 groups. The rats in the normal group and model group were administrated with the same amount of pure water. On day 5， the gouty arthritis model was established by injecting MSU into the right ankle joint of rats. The toe volume and joint inflammation index were measured 4， 8， 24， and 48 h after modeling. The pathological changes of the synovial tissue were detected by hematoxylin-eosin （HE） staining. Enzyme-linked immunosorbent assay （ELISA） was employed to measure the levels of tumor necrosis factor-alpha （TNF-α）， interleukin （IL）-1β， and IL-6 in the synovial tissue. Western blot was employed to measure the protein levels of NOD-like receptor protein 3 （NLRP3）， cysteine-aspartic protease-1 （Caspase-1）， apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain （ASC）， IL-1β， and cyclooxygenase-2 （COX-2） in the synovial tissue. Furthermore， the cell inflammation model was established with RAW264.7 cells stimulated with MSU （75 mg·L-1）. The cell experiments were carried out with 6 groups： a normal group， a model group， a positive drug （DXMS， 100 μmol·L-1） group， and low- （DH50-D， 25 mg·L-1）， medium- （DH50-Z， 50 mg·L-1）， and high-dose （DH50-G， 100 mg·L-1） DH50 groups. Methyl thiazolyl tetrazolium （MTT） assay was employed to determine the cell viability， ELISA to determine the content of TNF-α in the supernatant of cell culture， and Western blot to determine the protein levels of NLRP3， cleaved Caspase-1， IL-1β， TNF-α， and COX-2. ResultCompared with the normal group， the rat model group showed increased toe swelling degree and joint inflammatory index （P<0.01）， serious infiltration of the synovium， elevated levels of inflammatory cytokines in the tissue homogenate （P<0.01）， and up-regulated protein levels of NLRP3， Caspase-1， ASC， IL-1β， and COX-2 （P<0.05， P<0.01）. Compared with the rat model group， low- and high-dose DH50 mitigated the toe swelling degree， decreased the joint inflammatory index， alleviated the inflammatory infiltration， lowered the levels of inflammatory cytokines in the tissue homogenate （P<0.01）， and down-regulated the expression of related proteins （P<0.05， P<0.01）. Compared with the normal group， the cell model group showed elevated level of TNF-α in the supernatant （P<0.01） and up-regulated protein levels of NLRP3， cleaved Caspase-1， IL-1β， TNF-α， and COX-2 （P<0.05）. Compared with the model group， low， medium， and high doses of DH50 lowered the level of TNF-α in the supernatant of cell culture in a dose-dependent manner and down-regulated the expression of related proteins （P<0.05， P<0.01）. ConclusionDH50 can mitigate gouty arthritis both in vitro and in vivo by inhibiting the activation of NLRP3 inflammasomes and the production of inflammatory cytokines.