Diabetic cardiomyopathy:Importance of direct evidence to support the roles of NOD-like receptor protein 3 inflammasome and pyroptosis

Recently,the roles of pyroptosis,a form of cell death induced by activated NODlike receptor protein 3(NLRP3)inflammasome,in the pathogenesis of diabetic cardiomyopathy(DCM)have been extensively investigated.However,most studies have focused mainly on whether diabetes increases the NLRP3 inflammasome and associated pyroptosis in the heart of type 1 or type 2 diabetic rodent models,and whether various medications and natural products prevent the development of DCM,associated with decreased levels of cardiac NLRP3 inflammasome and pyroptosis.The direct link of NLRP3 inflammasome and associated pyroptosis to the pathogenesis of DCM remains unclear based on the limited evidence derived from the available studies,with the approaches of NLRP3 gene silencing or pharmaceutical application of NLRP3 specific inhibitors.We thus emphasize the requirement for more systematic studies that are designed to provide direct evidence to support the link,given that several studies have provided both direct and indirect evidence under specific conditions.This editorial emphasizes that the current investigation should be circumspect in its conclusion,i.e.,not overemphasizing its role in the pathogenesis of DCM with the fact of only significantly increased expression or activation of NLRP3 inflammasome and pyroptosis in the heart of diabetic rodent models.Only clear-cut evidence-based causative roles of NLRP3 inflammasome and pyroptosis in the pathogenesis of DCM can help to develop effective and safe medications for the clinical management of DCM,targeting these biomarkers.

Compatibility with Fructus Ligustri Lucidi Effectively Mitigates Idiosyncratic Liver Injury of Epimedii Folium by Modulating NOD-like Receptor Family Pyrin Domain Containing 3 Inflammasome Activation

Background: Idiosyncratic drug-induced liver injury(IDILI) is a serious side effect of drugs, Epimedii Folium(EF) is unequivocally implicated in idiosyncratic liver injury onset, potentially due to its ability to perturb the NOD-like receptor family pyrin domain containing 3(NLRP3) inflammasome. Fructus Ligustri Lucidi(FLL), a frequently used medicinal combination with EF, has not yet been investigated for its ability to ameliorate EF-associated hepatotoxicity. Aims and Objectives: Study on the mechanism of compatibility of FLL to alleviate liver injury caused by EF. Materials and Methods: Western blot was used to determine the expression of related proteins, ELISA was used to detect the secretion of related inflammatory factors IL-1β, IL-18, IL-6 and TNF-α, liver injury indexes were detected and liver pathological tissue staining was used to evaluate the liver injury. Results: Our results demonstrated that EF exerted a particular augmenting effect on the stimulation of the NLRP3 inflammasome mediated by nigericin or ATP, whereas FLL suppressed the NLRP3 inflammasome stimulation. Furthermore, an equal EF to FLL ratio significantly reduced the stimulatory effects of EF. Moreover, EF has the potential to induce hepatic injury and augment pro-inflammatory cytokine synthesis in rats subjected to LPS. However, when combined with FLL, the detrimental effects of EF were mitigated. Conclusions: FLL possesses the capacity to attenuate EF-associated hepatotoxicity by suppressing EF-triggered NLRP3 inflammasome activation. Thus, FLL holds promise for improving the clinical safety profile of EF, shedding light on the potential of compatibility and detoxification theories in traditional Chinese medicine.

3'-Deoxyadenosin alleviates methamphetamine-induced aberrant synaptic plasticity and seeking behavior by inhibiting the NLRP3 inflammasome

Methamphetamine addiction is a brain disorder characterized by persistent drug-seeking behavior, which has been linked with aberrant synaptic plasticity. An increasing body of evidence suggests that aberrant synaptic plasticity is associated with the activation of the NOD-like receptor family pyrin domain containing-3(NLRP3) inflammasome. 3′-Deoxyadenosin, an active component of the Chinese fungus Cordyceps militaris, has strong anti-inflammatory effects. However, whether 3′-deoxyadenosin attenuates methamphetamine-induced aberrant synaptic plasticity via an NLRP3-mediated inflammatory mechanism remains unclear. We first observed that 3′-deoxyadenosin attenuated conditioned place preference scores in methamphetamine-treated mice and decreased the expression of c-fos in hippocampal neurons. Furthermore, we found that 3′-deoxyadenosin reduced the aberrant potentiation of glutamatergic transmission and restored the methamphetamine-induced impairment of synaptic plasticity. We also found that 3′-deoxyadenosin decreased the expression of NLRP3 and neuronal injury. Importantly, a direct NLRP3 deficiency reduced methamphetamine-induced seeking behavior, attenuated the impaired synaptic plasticity, and prevented neuronal damage. Finally, NLRP3 activation reversed the effect of 3′-deoxyadenosin on behavior and synaptic plasticity, suggesting that the anti-neuroinflammatory mechanism of 3′-deoxyadenosin on aberrant synaptic plasticity reduces methamphetamine-induced seeking behavior. Taken together, 3′-deoxyadenosin alleviates methamphetamine-induced aberrant synaptic plasticity and seeking behavior by inhibiting the NLRP3 inflammasome.

Jianpi Gushen Huayu decoction ameliorated diabetic nephropathy through modulating metabolites in kidney,and inhibiting TLR4/NF-κB/NLRP3 and JNK/P38 pathways

BACKGROUND Jianpi Gushen Huayu Decoction(JPGS)has been used to clinically treat diabetic nephropathy(DN)for many years.However,the protective mechanism of JPGS in treating DN remains unclear.AIM To evaluate the therapeutic effects and the possible mechanism of JPGS on DN.METHODS We first evaluated the therapeutic potential of JPGS on a DN mouse model.We then investigated the effect of JPGS on the renal metabolite levels of DN mice using non-targeted metabolomics.Furthermore,we examined the effects of JPGS on c-Jun N-terminal kinase(JNK)/P38-mediated apoptosis and the inflammatory responses mediated by toll-like receptor 4(TLR4)/nuclear factor-kappa B(NF-κB)/NOD-like receptor family pyrin domain containing 3(NLRP3).RESULTS The ameliorative effects of JPGS on DN mice included the alleviation of renal injury and the control of inflammation and oxidative stress.Untargeted metabolomic analysis revealed that JPGS altered the metabolites of the kidneys in DN mice.A total of 51 differential metabolites were screened.Pathway analysis results indicated that nine pathways significantly changed between the control and model groups,while six pathways significantly altered between the model and JPGS groups.Pathways related to cysteine and methionine metabolism;alanine,tryptophan metabolism;aspartate and glutamate metabolism;and riboflavin metabolism were identified as the key pathways through which JPGS affects DN.Further experimental validation showed that JPGS treatment reduced the expression of TLR4/NF-κB/NLRP3 pathways and JNK/P38 pathway-mediated apoptosis related factors.CONCLUSION JPGS could markedly treat mice with streptozotocin(STZ)-induced DN,which is possibly related to the regulation of several metabolic pathways found in kidneys.Furthermore,JPGS could improve kidney inflammatory responses and ameliorate kidney injuries in DN mice via the TLR4/NF-κB/NLRP3 pathway and inhibit JNK/P38 pathwaymediated apoptosis in DN mice.

Increased Expression of the NOD-like Receptor Family, Pyrin Domain Containing 3 Inflammasome in Dermatomyositis and Polymyositis is a Potential Contributor to Their Pathogenesis

Background： Dermatomyositis （DM） and polymyositis （PM） are common inflammatory myopathies whose immunopathogenic mechanisms remain poorly understood. The NOD-like receptor family, pyrin domain containing 3 （NLRP3） inflammasome is a type of cytoplasmic multiprotein inflammasome and is responsible for the activation of inflammatory reactivations. Responding to a wide range of exogenous and endogenous microbial or sterile stimuli, NLRP3 inflammasomes can cleave pro-caspase- 1 into active caspase- 1, which processes the pro-infammatory cytokines pro-interleukin （IL）-1 β and pro-IL-18 into active and secreted IL-1β and I L-18. The NLRP3 inflammasome is implicated in infectious and sterile inflammatory diseases. However, it remains unclear whether it is involved in the pathogenesis of DM/PM, which we aim to address in our research. Methods： In this study, 22 DM/PM patients and 24 controls were recruited. The protein and RNA expression of IL-113, IL-18, NLRP3, and caspase-1 in serum and muscle samples were tested and compared between the two groups. Results： The serum IL-1 β and IL-18 levels were significantly higher in DM/PM patients than those in the controls by enzyme linked immunosorbent assay （EL1SA, DM vs. control, 25.02 ± 8.29 ng/ml vs. 16.49 ± 3.30 ng/ml, P 〈 0.001 ; PM vs. control, 26.49±7.79 ng/ml vs. 16.49 ± 3.30 ng/ml, P 〈 0.001）. Moreover, the real-time quantitative reverse transcription-polymerase chain reaction （qRT-PCR） showed that DM/PM patients exhibited higher RNA expression of IL-lβ, IL-18, and NLRP3 in the muscle （for IL-1 β, DM vs. control, P 0.0012, PM vs. control, P = 0.0021 ; for IL- 18, DM vs. control, P = 0.0045, PM vs. control, P 0.0031 ; for NLRP3, DM vs. control, P = 0.0017, PM vs. control, P 0.0006）. Moreover, the protein expression of NLRP3 and caspase- 1 in muscle samples of DM/PM patients were also significantly elevated compared to that in the muscles of the controls. Conclusions： Our findings demonstrate that the NLRP3 inflammasome is implicated in the pathogenesis of DM/PM. High NLRP3 expression led to elevated levels of IL-l13 and IL-18 and could be one of the factors promoting disease progress.

A Novel Mutation in the Pyrin Domain of the NOD-like Receptor Family Pyrin Domain Containing Protein 3 in Muckle-Wells Syndrome

Background： Cryopyrin-associated periodic syndrome （CAPS） is a group of rare, heterogeneous autoinflammatory disease characterized by interleukin （IL）-1β-mediated systemic inflammation and clinical symptoms involving skin, joints, central nervous system, and eyes. It encompasses a spectrum of three clinically overlapping autoinflammatory syndromes including familial cold autoinflammatory syndrome, Muckle-Wells syndrome （MWS）, and neonatal-onset multisystem inflammatory disease. CAPS is associated with gain-of-function missense mutations in NOD-like receptor family pyrin domain-containing protein 3 （NLRP3）, the gene encoding NLRP3. Moreover, most mutations leading to MWS occurred in exon 3 ofNLRP3 gene. Here, we reported a novel mutation occurred in exon 1 ofNLRP3 gene in an MWS patient and attempted to explore the pathogenic mechanism. Methods： Genetic sequence analysis of NLRP3 was performed in an MWS patient who presented with periodic lever, arthralgia, and multiform skin lesions. NLRP3 was also analyzed in this patient＇s parents and 50 healthy individuals. Clinical examinations including X-ray examination, skin biopsy, bone marrow aspiration smear, and blood test of C-reactive protein （CRP）, erythrocyte sedimentation rate （ESR）, serum levels oflL-1β, immunoglobulin E （lgE）, antineutrophil cytoplasmic antibodies, antinuclear antibodies, and extractable nuclear antigen were also analyzed. The protein structure of mutant NLRP3 inflammasome was calculated by SWISS-MODEL software. Proteins of wild type and mutant components ofNLRP3 inflammasome were expressed and purified, and the interaction abilities between these proteins were tested by surface plasmon resonance （SPR） assay. Results： X-ray examination showed no abnormality in the patient＇s knees. Laboratory tests indicated an elevation of CRP （233.24 nag/L） and ESR （67 mm/h） when the patient had fever. Serum IL-1β increased to 24.37 pg/ml, and serum lgE was higher than 2500.00 IU/ml. Other blood tests were normal. Bone marrow aspiration smear was normal. A novel point mutation c.92A〉T in exon 1 of NLRP3 gene was identified, which caused a p.D31V mutation in pyrin domain （PYD） of NLRP3. SPR assay showed that this point mutation may strengthen the interaction between the PYD of NLRP3 and the PYD of the apoptosis-associated speck-like protein. The mutation c.92A〉T in exon 1 of the NLRP3 gene was not lbund in the patient＇s parents and 50 healthy individuals. Conclusions： The rnutation c.92A〉T in exon 1 of the NLRP3 gene is a novel mutation associated with MWS. The p.D31V mutation might promote the activation ofNLRP3 inflammasome and induce MWS in this patient.

Effect of Curcumol on NOD-Like Receptor Thermoprotein Domain 3 Inflammasomes in Liver Fibrosis of Mice

Objective:To investigate the effect of curcumol on NOD-like receptor thermoprotein domain 3(NLRP3)inflammasomes,and analyze the mechanism underlying curcumol against liver fibrosis.Methods:Thirty Kunming mice were divided into a control group,a model group and a curcumol group according to a random number table,10 mice in each group.Mice were intraperitoneally injected with 40% carbon tetrachloride(CCl4:peanut oil,2:3 preparation)at 5 m L/kg for 6 weeks,twice a week,for developing a liver fibrosis model.The mice in the control group were given the same amount of peanut oil,twice a week for 6 weeks.The mice in the curcumol group were given curcumol(30 m L/kg)intragastrically,and the mice in the model and control groups were given the same amount of normal saline,once a day for 6 weeks.Changes in liver structure were observed by hematoxylin and eosin(HE)and Masson staining.Liver function,liver fiber indices,and the expression of interleukin(IL)-10 and tumor necrosis factor-α(TNF-α)levels were determined by automatic biochemical analyzer and enzyme linked immunosorbent assay kit.Immunoblotting and reverse transcription-quantitative PCR(RT-qPCR)were performed to detect the expression of NLRP3 inflammasome-related molecules,TGF-β and collagen.Results:HE and Masson staining results showed that the hepatocytes of the model group were arranged irregularly with pseudo-lobular structure and a large amount of collagen deposition.The mice in the curcumol group had a significant decrease in liver function and liver fibers indices compared with the model group(P<0.05);RT-qPCR and Western blot results reveal that,in the curcumol group,the mRNA and protein expression levels of NLRP3,IL-1β,Caspase 1 and gasdermin D decreased significantly compared with the model group(P<0.05);immunohistochemical results showed that in the curcumol group,the protein expression levels of NLRP3 and IL-1β decreased significantly compared with the model group(P<0.05).Conclusion:A potential anti-liver fibrosis mechanism of curcumol may be associated with the inhibition of NLRP3 inflammasomes and decreasing the downstream inflammatory response.

平喘颗粒对哮喘小鼠NLRP3/Caspase-1/IL-1β通路的影响

目的 观察平喘颗粒对哮喘小鼠NOD样受体热蛋白结构域3(NLRP3)/半胱氨酸蛋白酶-1(Caspase-1)/白细胞介素-1β(IL-1β)通路的影响,探讨平喘颗粒治疗哮喘的作用机制。方法 将40只健康雌性小鼠随机分为空白组、模型组、布地奈德组及平喘颗粒组,每组10只。除空白组外,其余组建立哮喘模型。于致敏的前1 d开始,布地奈德组给予布地奈德混悬液0.5 mg/mL雾化吸入30 min,平喘颗粒组给予平喘颗粒药液31.2 g/kg灌胃,空白组和模型组给予等体积的0.9%氯化钠注射液灌胃,均连续干预4周。末次干预结束后,HE染色观察各组小鼠肺组织病理改变,ELISA检测肺泡灌洗液中白细胞介素-6(IL-6)和白细胞介素-18(IL-18)水平,RT-qPCR检测肺组织中NLRP3、Caspase-1和IL-1βmRNA表达情况。结果 与空白组比较,模型组小鼠气道大量炎性细胞浸润,肺泡灌洗液中IL-6、IL-18水平和肺组织中NLRP3、Caspase-1、IL-1βmRNA相对表达量均明显升高(P均<0.05)。与模型组比较,平喘颗粒组和布地奈德组小鼠气道炎症浸润明显减轻,肺泡灌洗液中IL-6、IL-18水平和肺组织中NLRP3、Caspase-1、IL-1βmRNA相对表达量均明显降低(P均<0.05),且平喘颗粒组肺泡灌洗液中IL-6水平和肺组织中NLRP3 mRNA相对表达量均明显低于布地奈德组(P均<0.05)。结论 平喘颗粒能够明显减轻哮喘小鼠的气道炎症,其作用机制可能与抑制NLRP3/Caspase-1/IL-1β通路有关。

Thioredoxin interacting protein,a key molecular switch between oxidative stress and sterile inflammation in cellular response

Tissue and systemic inflammation have been the main culprit behind the cellular response to multiple insults and maintaining homeostasis.Obesity is an independent disease state that has been reported as a common risk factor for multiple metabolic and microvascular diseases including nonalcoholic fatty liver disease(NAFLD),retinopathy,critical limb ischemia,and impaired angiogenesis.Sterile inflammation driven by high-fat diet,increased formation of reactive oxygen species,alteration of intracellular calcium level and associated release of inflammatory mediators,are the main common underlying forces in the pathophysiology of NAFLD,ischemic retinopathy,stroke,and aging brain.This work aims to examine the contribution of the pro-oxidative and pro-inflammatory thioredoxin interacting protein(TXNIP)to the expression and activation of NLRP3-inflammasome resulting in initiation or exacerbation of sterile inflammation in these disease states.Finally,the potential for TXNIP as a therapeutic target and whether TXNIP expression can be modulated using natural antioxidants or repurposing other drugs will be discussed.