scholarly journals Promise of the NLRP3 Inflammasome Inhibitors in In Vivo Disease Models

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4996
Author(s):  
Biswadeep Das ◽  
Chayna Sarkar ◽  
Vikram Singh Rawat ◽  
Deepjyoti Kalita ◽  
Sangeeta Deka ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Wide Spectrum ◽  
Biologically Active ◽  
Receptor Protein ◽  
Therapeutic Effects ◽  
Caspase 1 ◽  
Inflammatory Conditions ◽  
Molecular Patterns ◽  
Scientific Documentation

Nucleotide-binding oligomerization domain NOD-like receptors (NLRs) are conserved cytosolic pattern recognition receptors (PRRs) that track the intracellular milieu for the existence of infection, disease-causing microbes, as well as metabolic distresses. The NLRP3 inflammasome agglomerates are consequent to sensing a wide spectrum of pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs). Certain members of the NLR family have been documented to lump into multimolecular conglomerates called inflammasomes, which are inherently linked to stimulation of the cysteine protease caspase-1. Following activation, caspase-1 severs the proinflammatory cytokines interleukin (IL)-1β and IL-18 to their biologically active forms, with consequent commencement of caspase-1-associated pyroptosis. This type of cell death by pyroptosis epitomizes a leading pathway of inflammation. Accumulating scientific documentation has recorded overstimulation of NLRP3 (NOD-like receptor protein 3) inflammasome involvement in a wide array of inflammatory conditions. IL-1β is an archetypic inflammatory cytokine implicated in multiple types of inflammatory maladies. Approaches to impede IL-1β’s actions are possible, and their therapeutic effects have been clinically demonstrated; nevertheless, such strategies are associated with certain constraints. For instance, treatments that focus on systemically negating IL-1β (i.e., anakinra, rilonacept, and canakinumab) have been reported to result in an escalated peril of infections. Therefore, given the therapeutic promise of an NLRP3 inhibitor, the concerted escalated venture of the scientific sorority in the advancement of small molecules focusing on direct NLRP3 inflammasome inhibition is quite predictable.

scholarly journals Suppression of lncRNA NLRP3 inhibits NLRP3-triggered inflammatory responses in early acute lung injury

2021 ◽  
Vol 12 (10) ◽  
Author(s):  
Deqiang Luo ◽  
Wei Dai ◽  
Xiaojin Feng ◽  
Chengzhi Ding ◽  
Qiang Shao ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Inflammatory Response ◽  
Nlrp3 Inflammasome ◽  
Receptor Protein ◽  
Luciferase Reporter ◽  
Lung Pathology ◽  
Caspase 1

AbstractAcute lung injury (ALI) is a common lung pathology that is accompanied by alveolar macrophage (AM) activation and inflammatory response. This study investigated the role of the long non-coding RNA NONRATT004344 (hereafter named lncRNA NLRP3) in regulating the Nod-like receptor protein 3 (NLRP3)-triggered inflammatory response in early ALI and the underlying mechanism as well. We established LPS-induced ALI models to explore their interactive mechanisms in vitro and in vivo. Luciferase reporter assays were performed to determine that miR-138-5p could bind to lncRNA NLRP3 and NLRP3. We observed increased lncRNA NLRP3 expression, decreased miR-138-5p expression, NLRP3 inflammasome activation, and upregulated caspase-1, IL-1β, and IL-18 expression in the LPS-induced ALI model. Furthermore, lncRNA NLRP3 overexpression activated the NLRP3 inflammasome and promoted IL-1β and IL-18 secretion; the miR-138-5p mimic abolished these effects in vivo and in vitro. Consistently, miR-138-5p inhibition reversed the effects of lncRNA NLRP3 silencing on the expression of NLRP3-related molecules and inhibition of the NLRP3/caspase-1/IL-1β signalling pathway. Mechanistically, lncRNA NLRP3 sponging miR-138-5p facilitated NLRP3 activation through a competitive endogenous RNA (ceRNA) mechanism. In summary, our results suggested that lncRNA NLRP3 binding miR-138-5p promotes NLRP3-triggered inflammatory response via lncRNA NLRP3/miR-138-5p/NLRP3 ceRNA network (ceRNET) and provides insights into the treatment of early ALI.

scholarly journals Vanillic Acid Reduces Pain-Related Behavior in Knee Osteoarthritis Rats Through the Inhibition of NLRP3 Inflammasome-Related Synovitis

2021 ◽  
Vol 11 ◽  
Author(s):  
Zhenyuan Ma ◽  
Zhengquan Huang ◽  
Li Zhang ◽  
Xiaochen Li ◽  
Bo Xu ◽  
...  
Keyword(s):  
Knee Osteoarthritis ◽  
Vanillic Acid ◽  
Nlrp3 Inflammasome ◽  
Animal Experiments ◽  
Herbal Medicines ◽  
Receptor Protein ◽  
Caspase 1 ◽  
Monosodium Iodoacetate

Objectives: Synovitis plays an important role in knee osteoarthritis (KOA) pain. The activation of the NOD-like receptor protein 3 (NLRP3) inflammasome in fibroblast-like synoviocytes (FLSs) promotes KOA development. In this study, we aimed to investigate whether vanillic acid (VA), a monomer derived from Chinese herbal medicines, could target NLRP3 inflammasome-related synovitis to reduce pain.Methods: Rats in the KOA and KOA + VA groups were injected with monosodium iodoacetate (MIA) in the knee to induce KOA. From day 14, the KOA + VA group was given VA at 30 mg/kg every day via gastric intubation. FLSs were collected from the synovial tissues. We examined both the protein and gene expression of caspase-1, apoptosis-associated speck-like protein with a caspase recruitment domain (ASC), NLRP3, components of the NLRP3 inflammasome, and interleukin-1β (IL-1β) and IL-18 in vivo and in vitro.Results: The upregulation of caspase-1, ASC, and NLRP3 in the KOA model were reduced by VA. VA also lowered the level of IL-1β and IL-18 in the KOA model. In addition, VA relieved pain-related behavior of KOA model rats and downregulated the pain mediators CGRP, NGF, and TrkA in FLSs. Interestingly, we also observed reduced synovial fibrosis in the animal experiments.Conclusion: Our research showed that VA reduces synovitis and pain-related behaviors in a rat model of KOA, which provides the basis for further investigations into the potential therapeutic impact of VA in KOA.

scholarly journals Baicalein Exerts Anti-Neuroinflammatory Effects by Inhibiting the TLR4-ROS /NF-κB-NLRP3 Inflammasome

2021 ◽  
Vol 16 (4) ◽  
pp. 1934578X2110113
Author(s):  
Wenyu Xin ◽  
Ming Jing ◽  
Junjie Yang ◽  
Meiling Wang ◽  
Guige Hou ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Inflammatory Responses ◽  
Critical Role ◽  
Underlying Mechanism ◽  
Receptor Protein ◽  
Motor Impairments ◽  
Caspase 1 ◽  
Mediated Effects

Emerging evidence indicates that NOD-like receptor protein 3 (NLRP3) inflammasome-induced inflammation plays a critical role in the pathogenesis of Parkinson’s disease (PD). Baicalein has been considered as a possible option for PD treatment based on its anti-neuroinflammatory effects. However, no studies have elucidated the precise mechanisms underlying the anti-neuroinflammatory activity of baicalein, particularly inflammasome-mediated effects. In this present study, rotenone-induced PD mice and BV2 microglia were used to investigate the anti-neuroinflammatory effects of baicalein and explore its underlying mechanism in vivo and in vitro. The results demonstrated that baicalein alleviated motor impairments and attenuated several inflammatory responses in rotenone-induced PD mice. Also, baicalein inhibited the expression of NLRP3 and activated caspase-1 in brain tissues. Correspondingly, baicalein prominently suppressed the inflammatory response in BV2 microglia induced by rotenone. Furthermore, in vitro data showed that baicalein suppressed the expression of NLRP3 and activated caspase-1 by abrogating the upregulation of ROS, as well as by inhibiting the TLR4/NF-κB signaling cascade. Overall, the results of the present study indicated that baicalein exerted anti-neuroinflammatory effects partly by inhibiting activation of the NLRP3 inflammasome, and targeting NLRP3 inflammasome signaling offers a novel therapeutic strategy for PD treatment.

scholarly journals The Essential Oil of Artemisia argyi H.Lév. and Vaniot Attenuates NLRP3 Inflammasome Activation in THP-1 Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Pengxiao Chen ◽  
Qi Bai ◽  
Yanting Wu ◽  
Qiongzhen Zeng ◽  
Xiaowei Song ◽  
...  
Keyword(s):  
Essential Oil ◽  
Nlrp3 Inflammasome ◽  
Therapeutic Potential ◽  
Inflammasome Activation ◽  
Caspase 1 ◽  
Artemisia Argyi ◽  
Nlrp3 Inflammasome Activation ◽  
Long Time

Artemisia argyi H. Lév. and Vaniot is a traditional medical herb that has been used for a long time in China and other Asian counties. Essential oil is the main active fraction of Artemisia argyi H. Lév. and Vaniot, and its anti-inflammatory potential has been observed in vitro and in vivo. Here, we found that the essential oil of Artemisia argyi H. Lév. and Vaniot (EOAA) inhibited monosodium urate (MSU)- and nigericin-induced NLRP3 inflammasome activation. EOAA suppressed caspase-1 and IL-1β processing and pyroptosis. NF-κB p65 phosphorylation and translocation were also inhibited. In addition, EOAA suppressed nigericin-induced NLRP3 inflammasome activation without blocking ASC oligomerization, suggesting that it may inhibit NLRP3 inflammasome activation by preventing caspase-1 processing. Our study thus indicates that EOAA inhibits NLRP3 inflammasome activation and has therapeutic potential against NLRP3-driven diseases.

scholarly journals Astragaloside IV Suppresses High Glucose-Induced NLRP3 Inflammasome Activation by Inhibiting TLR4/NF-κB and CaSR

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Bin Leng ◽  
Yingjie Zhang ◽  
Xinran Liu ◽  
Zhen Zhang ◽  
Yang Liu ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
High Glucose ◽  
Inflammasome Activation ◽  
Astragaloside Iv ◽  
Caspase 1 ◽  
Endothelial Inflammation ◽  
Nlrp3 Inflammasome Activation ◽  
Anti Inflammatory

Long-term exposure to high glucose induces vascular endothelial inflammation that can result in cardiovascular disease. Astragaloside IV (As-IV) is widely used for anti-inflammatory treatment of cardiovascular diseases. However, its mechanism of action is still not fully understood. In this study, we investigated the effect of As-IV on high glucose-induced endothelial inflammation and explored its possible mechanisms. In vivo, As-IV (40 and 80 mg/kg/d) was orally administered to rats for 8 weeks after a single intraperitoneal injection of streptozotocin (STZ, 65 mg/kg). In vitro, human umbilical vein endothelial cells (HUVECs) were treated with high glucose (33 mM glucose) in the presence or absence of As-IV, NPS2143 (CaSR inhibitor), BAY 11-7082 (NF-κB p65 inhibitor), and INF39 (NLRP3 inhibitor), and overexpression of CaSR was induced by infection of CaSR-overexpressing lentiviral vectors to further discuss the anti-inflammatory property of As-IV. The results showed that high glucose increased the expression of interleukin-18 (IL-18), interleukin-1β (IL-1β), NLRP3, caspase-1, and ASC, as well as the protein level of TLR4, nucleus p65, and CaSR. As-IV can reverse these changes in vivo and in vitro. Meanwhile, NPS2143, BAY 11-7082, and INF39 could significantly abolish the high glucose-enhanced NLRP3, ASC, caspase-1, IL-18, and IL-1β expression in vitro. In addition, both NPS2143 and BAY 11-7082 attenuated high glucose-induced upregulation of NLRP3, ASC, caspase-1, IL-18, and IL-1β expression. In conclusion, this study suggested that As-IV could inhibit high glucose-induced NLRP3 inflammasome activation and subsequent secretion of proinflammatory cytokines via inhibiting TLR4/NF-κB signaling pathway and CaSR, which provides new insights into the anti-inflammatory activity of As-IV.

scholarly journals Curcumin, a cancer chemopreventive and chemotherapeutic agent, is a biologically active iron chelator

Blood ◽  
2009 ◽  
Vol 113 (2) ◽  
pp. 462-469 ◽  
Author(s):  
Yan Jiao ◽  
John Wilkinson ◽  
Xiumin Di ◽  
Wei Wang ◽  
Heather Hatcher ◽  
...  
Keyword(s):  
Iron Deficiency ◽  
Cultured Cells ◽  
Transferrin Saturation ◽  
Iron Chelator ◽  
Biologically Active ◽  
Liver Iron ◽  
Liver Iron Content ◽  
Inflammatory Conditions ◽  
Dose Dependent

Abstract Curcumin is a natural product currently in human clinical trials for a variety of neoplastic, preneoplastic, and inflammatory conditions. We previously observed that, in cultured cells, curcumin exhibits properties of an iron chelator. To test whether the chelator activity of curcumin is sufficient to induce iron deficiency in vivo, mice were placed on diets containing graded concentrations of both iron and curcumin for 26 weeks. Mice receiving the lowest level of dietary iron exhibited borderline iron deficiency, with reductions in spleen and liver iron, but little effect on hemoglobin, hematocrit, transferrin saturation, or plasma iron. Against this backdrop of subclinical iron deficiency, curcumin exerted profound 2 effects on systemic iron, inducing a dose-dependent decline in hematocrit, hemoglobin, serum iron, and transferrin saturation, the appearance of microcytic anisocytotic red blood cells, and decreases in spleen and liver iron content. Curcumin repressed synthesis of hepcidin, a peptide that plays a central role in regulation of systemic iron balance. These results demonstrate that curcumin has the potential to affect systemic iron metabolism, particularly in a setting of subclinical iron deficiency. This may affect the use of curcumin in patients with marginal iron stores or those exhibiting the anemia of cancer and chronic disease.

scholarly journals Dual Role of Triptolide in Interrupting the NLRP3 Inflammasome Pathway to Attenuate Cardiac Fibrosis

2019 ◽  
Vol 20 (2) ◽  
pp. 360 ◽  
Author(s):  
Xi-Chun Pan ◽  
Ya Liu ◽  
Yan-Yan Cen ◽  
Ya-Lan Xiong ◽  
Jing-Mei Li ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Dual Role ◽  
Receptor Protein ◽  
Inflammasome Activation ◽  
Collagen Production ◽  
Antifibrotic Effect ◽  
Myeloid Differentiation Factor

In a previous paper, we reported that triptolide (TP), a commonly used immunomodulator, could attenuate cardiac hypertrophy. This present study aimed to further explore the inhibition of cardiac fibrosis by TP and the possible mechanism from the perspective of the NOD-like receptor protein 3 (NLRP3) inflammasome. Hematoxylin-eosin and Masson’s staining, immunohistochemistry, and immunofluorescence were performed to observe cardiac fibrotic changes in mice and mouse cardiac fibroblasts (CFs). The Western blot, colocalization, and immunoprecipitation were applied to detect protein expression and interactions. Results suggested that TP dose-dependently inhibited cardiac fibrosis induced by isoproterenol and collagen production of CFs induced by angiotensin II. TP exhibited an antifibrotic effect via inhibiting activation of the NLRP3 inflammasome, which sequentially decreased IL-1β maturation, myeloid differentiation factor 88 (MyD88)-related phosphorylation of c-Jun N-terminal kinase (JNK), extracellular regulated protein kinase 1/2 (ERK1/2), and TGF-β1/Smad signaling, and ultimately resulted in less collagen production. Moreover, TP showed no antifibrotic effect in Nlrp3-knockout CFs. Notably, TP inhibited the expression of NLRP3 and apoptosis-associated speck-like proteins containing a caspase recruitment domain (ASC) as well as inflammasome assembly, by interrupting the NLRP3-ASC interaction to inhibit inflammasome activation. Finally, TP indeed inhibited the NLRP3-TGFβ1-Smad pathway in vivo. Conclusively, TP was found to play a dual role in interrupting the activation of the NLRP3 inflammasome to attenuate cardiac fibrosis.

scholarly journals Distinct expression profile and histological distribution of NLRP3 inflammasome components in the tissues of Hainan black goat suggest a site-specific role in the inflammatory response

2017 ◽  
Vol 65 (3) ◽  
pp. 402-416 ◽  
Author(s):  
Kaizhao Zhang ◽  
Pan Tao ◽  
Jianxin Liu ◽  
Qingnan Wang ◽  
Shikun Ge ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Nlrp3 Inflammasome ◽  
Cortical Neurons ◽  
Inflammatory Diseases ◽  
Polyclonal Antibodies ◽  
Receptor Protein ◽  
Mesenteric Lymph Nodes ◽  
Specific Expression ◽  
Caspase 1 ◽  
Black Goat

The NOD-like receptor protein 3 (NLRP3) inflammasome comprised of NLRP3, ASC and caspase-1 plays an important role in the inflammatory and innate immune response. However, little is known about the expression pattern and histological distribution of these genes in goat. Here, we first cloned the fulllength cDNAs of the NLRP3, ASC and caspase-1 genes of Hainan black goat and produced their polyclonal antibodies. Tissue-specific expression and histological distribution of these genes were analysed. Phylogenetic analysis revealed that these three goat genes had high homology with Bos taurus genes and low homology with avian or fish genes. After immunisations with these recombinant Histagged proteins, the titres of antiserum were higher than 1:1024 and purified IgG was obtained. These three genes were expressed in all examined tissues, the mRNA expression level of NLRP3 and caspase-1 was most abundant in the spleen and mesenteric lymph nodes (MLNs), while ASC was primary expressed in the liver, spleen and kidney. The histological distribution of NLRP3, ASC and caspase-1 was detected in myocardial cells, hepatocytes, focal lymphocytes, bronchiolar epithelial cells, renal tubular epithelial cells, cortical neurons and endothelial cells of the germinal centres in the MLNs. These results will be helpful in further investigations into the function of the NLRP3 inflammasome and in elucidating its role in caprine inflammatory diseases.

The Transcription Factor Gfi1 Negatively Regulates NLRP3 inflammasome-Mediated IL-1β Secretion in Macrophages

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 4119-4119
Author(s):  
Zhu Liuluan ◽  
Meng Qingcai ◽  
Liang Shuntao ◽  
Li Guoli ◽  
Hong Zheng ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Critical Role ◽  
Biologically Active ◽  
Luciferase Reporter ◽  
Transcriptional Level ◽  
Inflammasome Activation ◽  
Nlrp3 Gene ◽  
Caspase 1 ◽  
Reporter Assays ◽  
Nlrp3 Expression

Abstract Background: IL-1β secretion is tightly controlled at the transcriptional and post-translational levels. The NLRP3 inflammasome, a multiprotein complex composed of NOD-like receptor-containing pyrin 3 (NLRP3), apoptosis-associated speck-like protein (ASC) and pro-caspase-1, plays a critical role in IL-1β maturation at the latter stage. NLRP3 expression is a limiting factor for inflammasome activation, and therefore, negative regulation of this factor is necessary to control excessive IL-1β production during sepsis. Previously, we showed that the transcriptional repressor Gfi1 inhibits pro-IL-1β transcription and the IL-1β level is significantly higher in serum of LPS-treated Gfi1-/- than wild-type (WT) mice. The present study revealed that Gfi1 regulates IL-1β secretion through inhibiting NLRP3 inflammasome activation in macrophages. Methods and Results: Bone marrow-derived macrophages (BMDM) from WT and Gfi1-/- mice were primed with LPS and stimulated with ATP. Compared with WT cells, those lacking Gfi1 induced a significant increase in IL-1β in the culture medium (Figure 1A). Western blot disclosed moderate elevation of pro-IL-1β, along with a more dramatic increase in mature IL-1β and cleaved caspase-1 in Gfi1-deficient BMDMs, suggesting that Gfi1 inhibits IL-1β maturation. Consistently, real-time PCR findings showed increased NLRP3 mRNA in Gfi1-deficient macrophages (Figure 1B), implying that Gfi1 affects expression of NLRP3 at the transcriptional level. To determine the mechanism underlying the regulatory activity of Gfi1 on NLRP3 expression, the mouse NLRP3 promoter was screened, leading to the identification of a putative binding site for Gfi1 (GRE1, located at nt -1210/-1207). In dual luciferase reporter assays performed with WT and GRE1 mutant promoters, the inhibitory effect of Gfi1 on NLRP3 transcription was significantly reversed upon GRE1 mutation. EMSA and ChIP assays performed to further establish the function of GRE1 (Figure 2A) validated the in vivo and in vitro interactions between Gfi1 and the GRE1 element, and consequently, a direct transcriptional repression effect on the NLRP3 gene. NF-κB p65 activates NLRP3 transcription through binding two elements in its promoter region, and Gfi1 interferes with activity through direct interactions with p65. Accordingly, we mutated the binding elements of p65 (NRE1 and NRE2) in the NLRP3 promoter. Dual luciferase reporter assays showed that mutation of NRE1 almost entirely suppressed activation of p65 while mutation of NRE2 exerted no effect, indicating that NF-κB p65 specifically interacts with NRE1 for the activation in this system. EMSA studies further confirmed that Gfi1 strongly competes for binding of NF-κB p65 with NRE1, antagonizing interactions between p65 and the NLRP3 promoter (Figure 2B). Maximum suppression of NLRP3 promoter activity by Gfi1 was observed with the NLRP3 promoter reporter containing a NRE1/ GRE1 double mutant (Figure 2C). Conclusions: In summary, we propose a “dual repression model” mechanism of Gfi1 in the regulation of NLRP3 expression. Once activated by LPS, NF-κB promotes NLRP3 expression by binding to the cis-element, NRE1, in turn, promoting assembly of the NLRP3 inflammasome to generate biologically active IL-1β. Meanwhile, Gfi1 is induced to control LPS-induced inflammation. Gfi1 directly inhibits NLRP3 transcription by binding the GRE1 site or blocks NF-κB-mediated NLRP3 transcription via interactions with NF-κB p65. Both modes of action lead to suppression of IL-1β release from macrophages in response to LPS stimulation. The present data, along with previous reports showing that Gfi1 restricts pro-IL-1β transcription, indicate that Gfi1 plays pivotal roles in regulating IL-1β production at both transcriptional and post-translational levels. These findings provide novel evidence that should aid in the development of future anti-inflammatory therapies to prevent IL-1β-induced tissue injury and mortality during sepsis. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures No relevant conflicts of interest to declare.

scholarly journals In Vivo Discrimination of Type 3 Secretion System-Positive and -Negative Pseudomonas aeruginosa via a Caspase-1-Dependent Pathway

2010 ◽  
Vol 78 (11) ◽  
pp. 4744-4753 ◽  
Author(s):  
Tamding Wangdi ◽  
Lilia A. Mijares ◽  
Barbara I. Kazmierczak
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Immune System ◽  
Innate Immune System ◽  
Interleukin 1 ◽  
Innate Immune ◽  
Secretion Systems ◽  
Caspase 1 ◽  
Molecular Patterns ◽  
Type 3

ABSTRACT Microbe-associated molecular patterns are recognized by Toll-like receptors of the innate immune system. This recognition enables a rapid response to potential pathogens but does not clearly provide a way for the innate immune system to discriminate between virulent and avirulent microbes. We find that pulmonary infection of mice with type 3 translocation-competent Pseudomonas aeruginosa triggers a rapid inflammatory response, while infection with isogenic translocation-deficient mutants does not. Discrimination between translocon-positive and -negative bacteria requires caspase-1 activity in bone marrow-derived cells and interleukin-1 receptor signaling. Thus, the activation of caspase-1 by bacteria expressing type 3 secretion systems allows for rapid recognition of bacteria expressing conserved functions associated with virulence.

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