Mecanismos y dianas terapéuticas del inflamasoma NLRP3 en la miocardiopatía diabética / NLRP3 inflammasome mechanism and therapeutic targets in diabetic cardiomyopathy

Resumen La cardiomiopatía diabética es una complicación grave de la diabetes causada por estrés oxidativo, inflamación, resistencia a la insulina, fibrosis miocárdica y lipotoxicidad. Se trata de un padecimiento insidioso, complejo y difícil de tratar. El inflamasoma NLRP3 desencadena la maduración y liberación de citoquinas proinflamatorias, participa en procesos fisiopatológicos como la resistencia a la insulina y la fibrosis miocárdica, además de estar estrechamente relacionado con la aparición y progresión de la cardiomiopatía diabética. El desarrollo de inhibidores dirigidos a aspectos específicos de la inflamación sugiere que el inflamasoma NLRP3 puede utilizarse para tratar la cardiomiopatía diabética. Este artículo pretende resumir el mecanismo y las dianas terapéuticas del inflamasoma NLRP3 en la cardiomiopatía diabética, así como aportar nuevas sugerencias para el tratamiento de esta enfermedad.

Abstract Diabetic cardiomyopathy (DCM) is a serious complication of diabetes caused by oxidative stress, inflammation, insulin resistance, myocardial fibrosis, and lipotoxicity; its nature is insidious, complex and difficult to treat. NLRP3 inflammasome triggers the maturation and release of pro-inflammatory cytokines, participates in pathophysiological processes such as insulin resistance and myocardial fibrosis, in addition to being closely related to the development and progression of diabetic cardiomyopathy. The development of inhibitors targeting specific aspects of inflammation suggests that NLRP3 inflammasome can be used to treat diabetic cardiomyopathy. This paper aims to summarize NLRP3 inflammasome mechanism and therapeutic targets in diabetic cardiomyopathy, and to provide new suggestions for the treatment of this disease.

10,11-Dehydrocurvularin attenuates inflammation by suppressing NLRP3 inflammasome activation / 中国天然药物

10,11-Dehydrocurvularin (DCV) is a natural-product macrolide that has been shown to exert anti-inflammatory activity. However, the underlying mechanism of its anti-inflammatory activity remains poorly understood. Aberrant activation of the NLRP3 inflammasome is involved in diverse inflammation-related diseases, which should be controlled. The results showed that DCV specifically inhibited the activation of the NLRP3 inflammasome in association with reduced IL-1β secretion and caspase-1 activation, without effect on the NLRC4 and AIM2 inflammasomes. Furthermore, DCV disturbed the interaction between NEK7 and NLRP3, resulting in the inhibition of NLRP3 inflammasome activation. The C=C double bond of DCV was required for the NLRP3 inflammasome inhibition induced by DCV. Importantly, DCV ameliorated inflammation in vivo through inhibiting the NLRP3 inflammasome. Taken together, our study reveals a novel mechanism by which DCV suppresses inflammation, which indicates the potential role of DCV in NLRP3 inflammasome-driven inflammatory disorders.

Drofenine as a Kv2.1 inhibitor alleviated AD-like pathology in mice through A β/Kv2.1/microglial NLRP3/neuronal tau axis / 中国药理学与毒理学杂志

OBJECTIVE Alzheimer disease(AD)is a neurodegenerative disease with clinical hallmarks of pro-gressive cognitive impairment.Synergistic effects of Aβ-tau cascade reaction are tightly implicated in AD patholo-gy,and microglial NLRP3 inflammasome activation drives neuronal tauopathy through microglia and neurons cross-talk.However,the underlying mechanism of how Aβ medi-ates NLRP3 inflammasome remains unclear.Shab related potassium channel member 1(Kv2.1)as a voltage gated po-tassium channel widely distributed in the central nervous system and plays an important role in regulating the out-ward potassium flow in neurons and glial cells.In current work,we aimed to explore the underlying mechanism of Kv2.1 in regulating Aβ/NLRP3 inflammasome/tau axis by using a determined Kv2.1 inhibitor drofenine(Dfe).METHODS Cell-based assays including Western blot-ting and immunofluorescence staining against primary microglia or neurons were carried out to expound the role of Kv2.1 channel in NLRP3 inflammasome activa-tion and subsequent neuronal tau hyperphosphorylation.For animal studies,new object recognition,Y-maze and Morris water maze were performed to evaluate the ame-lioration of Kv2.1 inhibition through either Kv2.1 inhibitor Dfe treatment or adeno-associated virus AAV-ePHP-si-Kv2.1injectionon5×FADADmodel mice.Assays of histol-ogy and immunostaining of tissue sections and Western blotting of brain tissues were performed to verify the con-clusion of cellular assays.RESULTS We reported that oligomeric Aβ(o-Aβ)bound to microglial Kv2.1 and pro-moted Kv2.1-dependent potassium leakage to activate NLRP3 inflammasome through JNK/NF-κB pathway sub-sequently resulting in neuronal tauopathy.Treatment of either Kv2.1 inhibitor Dfe or AAV-ePHP-si-Kv2.1 for brain-specific Kv2.1 knockdown deprived o-A β of its capability in inducing microglial NLRP3 inflammasome activation and neuronal tau hyperphosphorylation,while improved the cognitive impairment of 5×FAD AD model mice.CONCLUSION Our results have highly addressed that Kv2.1 channel is required for o-Aβ driving NLRP3 inflammasome activation and neuronal tauopathy in AD model mice and highlighted that Kv2.1 inhibition is a prom-ising therapeutical strategy for AD and Dfe as a Kv2.1 inhibitor shows potential in the treatment of this disease.

Heat-killed Lactobacillus murinus confers neuropro-tection against dopamine neuronal loss by targeting NLRP3 inflammasome / 中国药理学与毒理学杂志

OBJECTIVE In this study,the effects of live Lactobacillus murinus(L.m)and heat-killed L.muri-nus(H-k L.m)on DA neuronal damage in rats and the underlying mechanisms were investigated.METHODS Male SD rats were randomly divided into five groups:vehicle group,L.m/H-k L.m(1×109 cfu)group,6-OHDH group,6-OHDH + L.m/H-k L.m(1×107 cfu)group,and 6-OHDH + L.m/H-k L.m(1×109 cfu)group.Wild-type and NLRP3 knockout mice were divided into three groups:sham(vehicle),6-OHDH,and 6-OHDH + H-k L.m(1×109 cfu).The model was established after five weeks of pre-administration.Motor ability of experimental mice was assessed by rotarod,mine,and stepping experiments;the expression of dopaminergic neuron markers—tyro-sine hydroxylase(TH),microglial cell markers—ionized calnexin 1(IBA-1),and NOD-like receptor family protein 3(NLRP3)in the substantia nigra was detected by immunohistochemistry and immunofluorescence experi-ments.The expression changes of TH,IBA-1,NLRP3,apoptosis-associated microparticle protein(ASC),cas-pase 1,and inflammatory factors such as interleukin-1β(IL-1β),IL-18,and tumor necrosis factor-α(TNF-α)were detected by immunoblotting experiments.RESULTS H-k L.m ameliorated 6-OHDH-induced motor dysfunctions and loss of substantia nigra DA neurons,while no protec-tion was shown in live L.m treatment.At the same time,H-k L.m reduced the activation of NLRP3 inflammasome in microglia and the secretion of pro-inflammatory factors,thus inhibiting the development of neuroinflammation.Fur-thermore,H-k L.m failed to display its original neuropro-tective properties in NLRP3 inflammasome knockout mice.CONCLUSION H-k L.m conferred neuroprotec-tion against DA neuronal loss via the inhibition of microglial NLRP3 inflammasome activation,these findings provide a promising potential for future applications of L.m,and also beneficial strategy for PD treatment.

Tetrahydroxy stilbene glycoside ameliorates neuroin-flammation for Alzheimer's disease via cGAS-STING / 中国药理学与毒理学杂志

OBJECTIVE Alzheimer's disease(AD)is the most common neurodegenerative disease worldwide.Neuroinflammation is a potential target for the patients with AD.It is attributed to activated microglia and the release of various inflammatory mediators from infec-tion,ischemia and toxin accumulation.Accumulating evi-dence has indicated that the cGAS-STING pathway driven neuroinflammation in neurological disease.TSG is a main natural active ingredient that derived from polyg-onum multiflorum.Previous research from our group found that TSG has beneficial effects of anti-aging,anti-inflammatory action and improving memory function in APP/PS1 transgenic AD mice.Here,we investigated the effects of TSG on cognitive impairment and neuroinflam-mation in APP/PS1-AD mice and explore the underly-ing mechanism by which TSG ameliorates memory func-tion in the cGAS-STING-mediated inflammatory response.METHODS The Morris water mace test and the novel object recognition test were performed to test the effects of TSG on spatial learning and cognitive and memory abil-ity in APP/PS1 double transgenic AD mice model.In addi-tion,real-time quantitative PCR,Western blotting,ELISA analysis,and flow cytometry to examine gene and pro-tein expression of cGAS-STING related pro-inflammatory cytokines and chemokines.Statistical analyses were ana-lyzed using the SPSS 25.0 package by analysis of vari-ance(ANOVA).Neuman-Keuls or Tukey's multiple-com-parisons test were conducted as ANOVA justified post hoc comparisons between group means.RESULTS We demonstrated that AD transgenic mice exhibited cognitive deficits accompanied by the elevated serum and brain inflammation.The expressions of serum inflammatory cytokines and the activation of microglia in cerebral cor-tex and hippocampus were suppressed after TSG treat-ment,which was probably attributable to the decrease of cyclic GMP-AMP synthase(cGAS)and stimulator of interferon genes(STING)triggered immune response.Additionally,the data showed that TSG treatment reduced the expression level of inflammatory cytokines(IL-1β,TNF-α,IFN-β,IFN-α)in microglial cells BV2 primed with LPS and IFN-γ.CONCLUSION TSG implicated the health benefits in preventing cognitive disorders by inhib-iting neuroinflammation via cGAS-STING signalling path-way in AD.

Pharmacological inhibition of STING signaling attenu-ates MPTP-induced neuroinflammation and neurode-generation in experimental models of Parkinson's disease / 中国药理学与毒理学杂志

OBJECTIVE To investigate the effects of pharmacological inhibition of STING by C-176,a STING selective inhibitor,in experimental model of Parkinson's disease.METHODS The acute and sub-acute mice mod-els of Parkinson's disease(PD)were established by in-traperitoneal injection of 1-methyl-4-(2′-methylphenyl)-1,2,3,6-tetrahydrophine(MPTP).The selective STING inhibitor C-176 was administered by intraperitoneal injec-tion.The potential neuroprotective effects of C-176 were evaluated by behavioral test,tyrosine hydroxylase(TH)immunostaining,Nissl staining,Western blotting,qPCR and immunofluorescence.For in vitro study,the effects of C-176 on LPS/MPP+-induced inflammatory responses in BV2 microglial cells were determined by real time RT-PCR and Western blotting analysis.RESULTS Our study revealed that C-176 significantly inhibited STING signaling activation,ameliorated MPTP-induced dopami-nergic neurotoxicity,motor deficit and associated neuroin-flammation.Furthermore,pharmacological inhibition of STING in BV2 microglia treated with LPS/MPP+ exhibited decreased inflammatory responses.More importantly,C176 also reduced NLRP3 inflammasome activation both in vitro and in vivo.CONCLUSION The results of our study suggest that pharmacologic inhibition of STING protects against neuroinflammation that may act at least in part through suppressing NLRP3 inflammasome acti-vation and thus ameliorated dopaminergic neurodegener-ation.STING signaling may holds great promise for the development of new treatment strategy for PD as an effective therapeutic target.

Effects of NLRP3 inflammasome activation on the proliferation, migration and extracellular matrix deposition of pancreatic stellate cells / 中华胰腺病杂志

Objective:To investigate the effects of NOD-like receptor protein 3(NLRP3) inflammasome activation on the proliferation, migration and extracellular matrix desposition of activated pancreatic stellate cells(PSCs).Methods:The rat PSCs were isolated, cultured and identified, and were divided into control group or LPS group based on the pretreatment with LPS (10 μg/ml for 24 hours) or without. The expression of NLRP3 inflammasome associated molecules in PSCs culture medium was detected by ELISA. The PSCs with NLRP3 inhibition were constructed by shRNA carrying lentivirus infection and were divided into LPS+ negative control group and LPS+ lentivirus group based on whether the cells were treated with LPS and infected by lentivirus or not. The alteration in cell proliferation and migration were detected by CCK-8 kit and transwell chamber method. The expression of extracellular matrix α-SMA and collagen in PSCs was detected by immunofluorescence staining and the expression of TGF-β mRNA was analyzed by RT-qPCR.Results:The cytoplasm of PSCs which were cultured for 24 hours was rich in bright annular lipid droplets, and the cells expressed desmin. After 7 days of culture, the cell became larger in size, the lipid droplets basically disappeared, and the cells were activated and expressed α-SMA. The expression of caspase-1, IL-1β and IL-18 in the supernatant of PSCs culture medium in LPS group were significantly higher than those in control group (1.55±0.04 vs 0.65±0.03), (2.02±0.04 vs 1.05±0.05) and (1.70±0.05 vs 0.97±0.03), respectively. After inhibiting by lentivirus infection, the expression of NLRP3 in the lentivirus group (0.25±0.04) was significantly lower than that in negative control group (0.68±0.05). In control group, LPS group, LPS+ negative control group and LPS+ lentivirus group, the A490 values was 0.61±0.02, 1.15±0.06, 0.96±0.05, and 0.56±0.01, respectively; the migrating PSCs number was (64.12±4.58), (121.67±8.02), (111.67±4.67) and (69.67±8.08)/HF, respectively; the relative expression of α-SMA was 0.78±0.05, 4.12±0.04, 3.81±0.06 and 0.88±0.05, respectively; the relative expression of collagen was 0.65±0.03, 3.43±0.02, 2.67±0.02 and 0.48±0.03, respectively; and the expression of TGF-β mRNA was 0.22±0.03, 0.89±0.01, 0.86±0.03 and 0.43±0.02, respectively. The A490 value, the migrating cells number, the expression of α-SMA, collagen and the expression of TGF-β mRNA in LPS group and LPS+ negative control group was significantly higher than those in control group and LPS+ lentivirus group, and all the differences were statistically significant (all P value <0.05). Conclusions:NLRP3 inflammasome activation may accelerate the extracellular matrix deposition and pancreatic fibrogenesis by promoting PSCs proliferation and migration ability via regulating the biological functions.

Chinese Medicine Regulates NLRP3 Inflammasomes to Treat Diabetic Nephropathy： A Review / 中国实验方剂学杂志

Diabetic nephropathy （DN）， a major cause of chronic kidney disease （CKD）， aggravates the prevalence of end-stage renal disease （ESRD） and threatens human health. The pathogenesis of DN is complex， in which inflammation is a key pathological link in the cascade injury. Therefore， the treatment targeting inflammation helps to delay the progression of DN. NOD-like receptor protein 3 （NLRP3）， a classical proteasome， acts as an inducer of innate immune responses. The activated NLRP3 inflammasomes produce and release inflammatory mediators to trigger pyroptosis and uncontrolled autophagy and mediate the stress signals promoting renal fibrosis， thus participating in the development and progression of DN. The NLRP3 inflammasome as a core site inducing inflammation is widely involved in DN progression and may be a novel target. The active components and compound prescriptions of Chinese medicines are increasingly applied in the prevention and treatment of DN. The latest studies have discovered that Chinese medicines can treat DN by regulating the activation of NLRP3 inflammasomes. Although studies have been conducted to explore the mechanism of Chinese medicines in the treatment of DN via NLRP3 inflammasome， the systematic review remains to be carried out. This paper reviews the relevant publications in recent years and introduces the research progress from the assembly and activation of NLRP3 inflammasomes， the mechanism of NLRP3 inflammasomes in the treatment of DN， and the regulation of NLRP3 inflammasomes by Chinese medicines for the prevention and treatment of DN， aiming to lay a foundation for the relevant studies and provide new targets and strategies for the prevention and treatment of DN.

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.

Chinese Medicine Intervenes in NLRP3 Inflammasome in Treatment of Bone and Joint Diseases： A Review / 中国实验方剂学杂志

The prevalence of osteoporosis， osteoarthritis， gouty arthritis， rheumatoid arthritis， and intervertebral disc degeneration is increasing year by year with the growing number of elderly people， and the common clinical manifestations of these diseases include severe pain in different areas， which seriously affects the daily life of the patients. Therefore， how to relieve the pain and reduce the prevalence of bone and joint diseases and improve the quality of life of the patients is a hot spot in the medical field. Studies have confirmed that NOD-like receptor family， pyrin domain-containing protein 3 （NLRP3） inflammasomes， as pattern recognition receptors， are involved in the inflammation， chondrocyte proliferation， osteoblast and osteoclast differentiation， intervertebral disc cell inflammation and scorching， extracellular matrix degradation and apoptosis， mitochondrial dysfunction， endoplasmic reticulum stress， and reactive oxygen species damage， demonstrating close link with the development of bone and joint diseases. Chinese medicine has a long history and demonstrates remarkable therapeutic effects in the treatment of bone and joint diseases. It can mitigate the pathological changes of bone and joint diseases by inhibiting NLRP3 inflammasomes to alleviate the pain， playing a role in preventing and treating these diseases. Therefore， this paper briefly describes the relationship between NLRP3 inflammasomes and the development of bone and joint diseases by reviewing the latest research progress at home and abroad. We summarize the latest studies about the active components， extracts， and compound prescriptions of Chinese medicines in the treatment of bone and joint diseases via regulating NLRP3 inflammasomes. This review is expected to offer new insights into the in-depth research on the pathogenesis and drug treatment of bone and joint diseases and provide a basis for the clinical application of Chinese medicine in the prevention and treatment of such diseases.

The impact of human umbilical cord-derived mesenchymal stem cells on the pancreatic function of type 2 diabetic mice and their regulatory role on NLRP3 inflammasomes / 中华内科杂志

Objective:To investigate the effect and regulation of umbilical cord-derived mesenchymal stem cells (UC-MSCs) on islets function and NOD-like receptor family, pyrin domain containing 3 (NLRP3) and autophagy in type 2 diabetic mellitus (T2DM) mice.Methods:Experimental study. Twenty, 8-week-old, male C57BL/6J mice were selected and divided into a normal control group ( n=5) and a high-fat feeding modeling group ( n=15). The model of T2DM was established by high-fat feeding combined with intraperitoneal injection of low-dose streptozotocin. After successful modeling, those mice were divided into a diabetes group ( n=7) and a UC-MSCs treatment group ( n=7). The UC-MSCs treatment group was given UC-MSCs (1×10 6/0.2 ml phosphate buffer solution) by tail vein infusion once a week for a total of 4 weeks; the diabetes group was injected with the same amount of normal saline, and the normal control group was not treated. One week after the treatment, mice underwent intraperitoneal glucose tolerance tests and intraperitoneal insulin tolerance tests, and then the mice were sacrificed to obtain pancreatic tissue to detect the expressions of interleukin-1β (IL-1β) and pancreatic and duodenal homeobox 1 (PDX-1) by immunofluorescence. The bone marrow-derived macrophages were stimulated with lipopolysaccharide and adenosine triphosphate (experimental group) in vitro, then co-cultured with UC-MSCs for 24 h (treatment group). After the culture, enzyme-linked immunosorbent assay was used to detect the secretion level of IL-1β in the supernatant, and immunofluorescence staining was used to detect the expression of NLRP3 inflammasome, and related autophagy proteins. Statistical analysis was performed using unpaired one-way analysis of variance, repeated measure analysis of variance. Results:In vivo experiments showed that compared with the diabetes group, the UC-MSCs treatment group partially repaired islet structure, improved glucose tolerance and insulin sensitivity (all P<0.05), and the expression of PDX-1 increased and IL-1β decreased in islets under confocal microscopy. In vitro experiments showed that compared with the experimental group, the level of IL-1β secreted by macrophages in the treatment group was decreased [(85.9±74.6) pg/ml vs. (883.4±446.2) pg/ml, P=0.001], the expression of NLRP3 inflammasome and autophagy-related protein P62 was decreased, and the expressions of microtubule-associated protein 1 light chain 3β (LC3) and autophagy effector Beclin-1 were increased under confocal microscopy. Conclusions:UC-MSCs can reduce the level of pancreatic inflammation in T2DM mice, preserving pancreatic function. This might be associated with the ability of UC-MSCs to inhibit the activity of NLRP3 inflammasomes in macrophages and enhance autophagy levels.

Research on the mechanism of NLRP3 inflammasome in neurovascular unit impairment of diabetic retinopathy / 国际眼科杂志(Guoji Yanke Zazhi)

Diabetic retinopathy(DR)is a neurovascular disease caused by the neurovascular unit(NVU)impairment. Immune imbalance and inflammation are key factors that affect the normal function of NVU and lead to the progression of DR. Nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3)inflammasome is indicated as an important component of the inflammatory response, and it can identify endogenous danger signals, leading to the activation of caspase-1 and then activating a series of inflammatory cytokines and pyroptosis. Early activation of inflammasome maintains and promotes innate immunity against bacterial and viral infections, while excessive inflammasome activation results in excessive expression and ongoing action of inflammatory proteins, which in turn triggers off immune disorders and an inflammatory cascade that seriously harms the body. This review summarizes the recent research progress on the mechanism of NLRP3 inflammasome in NVU impairment of DR, including the related drugs targeting NLRP3 pathways.

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.

Effect of Jianpi Yichang Powder on NLRP3/ASC/Caspase-l Signaling Pathway in Rats with Ulcerative Colitis / 中国实验方剂学杂志

ObjectiveTo explore the effect of Jianpi Yichang power on the nucleotide-binding oligomerization domain-like receptor protein 3 （NLRP3） inflammasome signaling pathway in a rat model of ulcerative colitis （UC）. MethodSixty Sprague-Dawley rats were randomly divided into a normal group （n=10） and an experimental group （n=50）. The experimental group received 5% dextran sulfate sodium （DSS） solution freely for 7 days to induce UC， and then they were further randomly divided into model group， sulfasalazine （0.3 g·kg-1） group， and high-， medium-， and low-dose Jianpi Yichang power groups （54.4， 27.2， 13.6 g·kg-1） for continuous treatment of 14 days. The general condition of the rats was observed and recorded daily， and the disease activity index （DAI） was scored before and after treatment. Enzyme-linked immunosorbent assay （ELISA） was used to detect the levels of interleukin-1β （IL-1β） and interleukin-18 （IL-18） in the serum of rats in each group. Hematoxylin-eosin （HE） staining was performed to observe the histopathological changes in the colon tissue. Immunohistochemistry， Western blot， and Real-time polymerase chain reaction （Real-time PCR） were used to detect the positive protein expression， protein expression， and mRNA expression of NLRP3， apoptosis-associated speck-like protein containing a CARD （ASC）， and cysteine aspartate-special proteases-1（Caspase-1） in the colon tissue. ResultCompared with the condition in the normal group， the general condition of rats in the model group was relatively poor， with increased DAI scores （P<0.01）， pathological changes in the colon， increased levels of IL-1β and IL-18 in the serum （P<0.01）， and enhanced positive protein expression， protein expression， and mRNA expression of NLRP3， ASC， and Caspase-1 in the colon tissue （P<0.01）. Compared with the condition in the model group， the general condition of rats in the Jianpi Yichang power groups at various doses improved significantly， with reduced DAI scores （P<0.05， P<0.01）， alleviated pathological changes in the colon as revealed by HE staining， and reduced protein expression levels of NLRP3 and Caspase-1 in the colon tissue （P<0.05， P<0.01）. The serum levels of IL-1β and IL-18， and ASC protein expression in the colon， as well as the mRNA expression levels of NLRP3， ASC， and Caspase-1， decreased in the high- and medium-dose Jianpi Yichang power groups （P<0.05， P<0.01）. The positive protein expression levels of NLRP3， ASC， and Caspase-1 were reduced in the high-dose Jianpi Yichang power group （P<0.01）. The positive protein expression levels of ASC and Caspase-1 were reduced in the medium-dose Jianpi Yichang power group （P<0.05）. The mRNA expression level of ASC was reduced in the low-dose Jianpi Yichang power group （P<0.05）. ConclusionJianpi Yichang power can reduce colon immune inflammatory damage by regulating the NLRP3 inflammasome signaling pathway， thereby exerting a role in treating UC.

Traditional Chinese Medicine in Treatment of Ulcerative Colitis Based on NLRP3 Inflammasome： A Review / 中国实验方剂学杂志

Ulcerative colitis （UC） is a common inflammatory bowel disease （IBD） in clinical practice， characterized by symptoms such as abdominal pain， diarrhea， and bloody mucus in the stool. It is difficult to cure and has a high recurrence rate. The pathogenesis of UC is related to abnormal immune response， oxidative stress in intestinal tissues， and inflammatory reactions. As reported， the abnormal activation of the NOD-like receptor pyrin domain-containing protein 3 （NLRP3） inflammasome is involved in the pathological process of UC. This activation triggers pathological mechanisms such as oxidative stress， pyroptosis， and inflammation in intestinal epithelial cells. Therefore， blocking the abnormal activation of NLRP3 is beneficial for alleviating UC. Currently， western medicine treatment for UC mainly includes salicylic acid derivatives， corticosteroids， and biologics， but the overall efficacy is unsatisfactory. Traditional Chinese medicine （TCM） treatment of this disease has the advantages of significant efficacy and low recurrence rate. In recent years， great advances have been made in the basic research of using TCM methods to treat UC. Studies have found that TCM intervention targeting the NLRP3 inflammasome can significantly promote intestinal mucosal healing and treat UC， and the mechanism of action involves multiple targets， levels， and pathways. This article summarized the experimental research on the impact of TCM targeting the NLRP3 inflammasome on UC in recent years， and found that NLRP3 interacted with factors such as Caspase-1 and nuclear factor-κB （NF-κB）， thereby promoting the release of pro-inflammatory factors and cell pyroptosis in intestinal epithelial cells. This activation triggered oxidative stress， inflammatory reactions， and other pathological mechanisms. TCM acted on the NLRP3 inflammasome and its upstream and downstream factors to block the pathological process of UC， inhibit the pathological damage to the intestinal mucosa， and thereby alleviate colonic ulcers. The findings of this study provide a theoretical basis for the prevention and treatment of UC and further drug development.

Role of JNK/AP-1 signaling pathway in paraquat-induced activation of NLRP3 inflammasome in microglia / 环境与职业医学

Background Paraquat (PQ) is one of the environmental factors that can cause sporadic Parkinson's disease (PD). Microglia-mediated neuroinflammation plays an important role in the occurrence and development of PD. Our previous studies have found that low doses of PQ can activate BV-2 microglia to the M1 phenotype and exert pro-inflammatory effects, but the associated mechanism is not clear yet. Objective To explore the role of c-Jun N-terminal kinase (JNK)/activator protein 1 (AP-1) signaling pathway in PQ-induced activation of the NOD-like receptor thermal protein domain associated protoin 3 (NLRP3) inflammasome in microglia. Methods An in vitro microglia model was established. The cells were treated with 0, 0.03, 0.06,and 0.12 μmol·L−1 PQ for 24 h, the whole cell protein was extracted. The relative expression levels of JNK, AP-1 constituent proteins (c-Jun, c-Fos), NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), caspasse-1 precursor (pro caspase-1), interleukin-18 (IL-18), and interleukin-1β (IL-1β) were evaluated by Western blotting, to observe the effects of PQ exposure on JNK/AP-1 signaling pathway and NLRP3 inflammasome. After the treatment of 20 μmol·L−1 JNK inhibitor SP600125, the above proteins were detected again, to explore the driving effect of JNK/AP-1 signaling pathway on NLRP3 inflammasome activation. Results After PQ exposure, the relative expression levels of key proteins of JNK, c-Jun, and c-Fos, NLRP3, ASC, and pro caspase-1 in the 0.06 μmol·L−1 PQ group and the 0.12 μmol·L−1 PQ group were higher than those in the 0 μmol·L−1 PQ group (P＜0.05), and the relative expression levels of IL-18 and IL-1β increased with higher exposure (P＜0.05). After the treatment of JNK inhibitor SP600125, the relative expression levels of key proteins of JNK/AP-1 signaling pathway (JNK, c-Jun, and c-Fos), NLRP3 inflammasome (NLRP3, ASC, and Pro caspase-1), and inflammatory factors (IL-18 and IL-1β) in the control group, the 20 μmol·L−1 SP600125 group, and the 20 μmol·L−1 SP600125+0.06 μmol·L−1 PQ group were lower than those in the 0.06 μmol·L−1 PQ group (P＜0.05). Conclusion PQ exposure can activate the JNK/AP-1 signaling pathway and subsequently drive the activation of NLRP3 inflammasome in BV-2 microglia to mediate neuroinflammatory responses..

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.

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.

Costunolide covalently targets NACHT domain of NLRP3 to inhibit inflammasome activation and alleviate NLRP3-driven inflammatory diseases

The NLRP3 inflammasome's core and most specific protein, NLRP3, has a variety of functions in inflammation-driven diseases. Costunolide (COS) is the major active ingredient of the traditional Chinese medicinal herb Saussurea lappa and has anti-inflammatory activity, but the principal mechanism and molecular target of COS remain unclear. Here, we show that COS covalently binds to cysteine 598 in NACHT domain of NLRP3, altering the ATPase activity and assembly of NLRP3 inflammasome. We declare COS's great anti-inflammasome efficacy in macrophages and disease models of gouty arthritis and ulcerative colitis via inhibiting NLRP3 inflammasome activation. We also reveal that the α-methylene-γ-butyrolactone motif in sesquiterpene lactone is the certain active group in inhibiting NLRP3 activation. Taken together, NLRP3 is identified as a direct target of COS for its anti-inflammasome activity. COS, especially the α-methylene-γ-butyrolactone motif in COS structure, might be used to design and produce novel NLRP3 inhibitors as a lead compound.

Research progress on the mechanisms of inflammasomes during respiratory infections / 中华实用儿科临床杂志

Acute respiratory infections are the most common infectious diseases in children.Among them, respiratory viruses are the main pathogens that cause many respiratory diseases, system damages or even death.As the first line of defense against pathogens like respiratory viruses, the innate immune system recognizes the structural components of viruses and endogenous danger signals with the pattern recognition receptors on immune cells and epithelial cells.During this process, inflammasomes are assembled and activated, and they participate in the recognition of viruses, inflammatory and immune response against viruses.The present study aims to describe the composition and function of inflammasomes, as well as the activation and negative regulation mechanisms of inflammasomes during common respiratory infections.