• Biomedical Science Letters
• /
• v.26 no.1
• /
• pp.47-50
• /
• 2020

Recently, decades of robust researches on degenerative brain disorder have been highlighted on the interactive connection of gut and brain. In terms of inflammatory cytokine production, others have shown that Nucleotide-Binding Oligomerization Domain Containing 2 (NOD2) is involved with Leucine-Rich Repeat Kinase 2 (LRRK2). HEK293T cells were transiently co-transfected with Myc-tagged LRRK2 and Flag-tagged NOD2 and then followed by co-immunoprecipitation assay. In this study, we provide the novel finding of physical protein-protein interaction between NOD2 and LRRK2. G2019S variant has shown stronger interactions against NOD2 than those of wild type LRRK2. In an axis of NOD2-LRRK2 communication, it is believed to pave a new way in the understanding of the bidirectional molecular mechanism of brain disorder, including Parkinson's disease into gut inflammatory disease, including Crohn's disease.

• Parasites, Hosts and Diseases
• /
• v.54 no.6
• /
• pp.711-717
• /
• 2016

Toxoplasma gondii is an obligate intracellular parasite that stimulates production of high levels of proinflammatory cytokines, which are important for innate immunity. NLRs, i.e., nucleotide-binding oligomerization domain (NOD)-like receptors, play a crucial role as innate immune sensors and form multiprotein complexes called inflammasomes, which mediate caspase-1-dependent processing of $pro-IL-1{\beta}$. To elucidate the role of inflammasome components in T. gondiiinfected THP-1 macrophages, we examined inflammasome-related gene expression and mechanisms of inflammasome-regulated cytokine $IL-1{\beta}$ secretion. The results revealed a significant upregulation of $IL-1{\beta}$ after T. gondii infection. T. gondii infection also upregulated the expression of inflammasome sensors, including NLRP1, NLRP3, NLRC4, NLRP6, NLRP8, NLRP13, AIM2, and NAIP, in a time-dependent manner. The infection also upregulated inflammasome adaptor protein ASC and caspase-1 mRNA levels. From this study, we newly found that T. gondii infection regulates NLRC4, NLRP6, NLRP8, NLRP13, AIM2, and neuronal apoptosis inhibitor protein (NAIP) gene expressions in THP-1 macrophages and that the role of the inflammasome-related genes may be critical for mediating the innate immune responses to T. gondii infection.

• Laboraroty Animal Research
• /
• v.34 no.4
• /
• pp.295-301
• /
• 2018

Nucleotide-binding domain 1 (Nod1) is a cytosolic receptor that is responsible for the recognition of a bacterial peptidoglycan motif containing meso-diaminophimelic acid. In this study, we sought to identify the role of Nod1 in host defense in vivo against pulmonary infection by multidrug resistant Acinetobacter baumannii. Wildtype (WT) and Nod1-deficient mice were intranasally infected with $3{\times}10^7CFU$ of A. baumannii and sacrificed at 1 and 3 days post-infection (dpi). Bacterial CFUs, cytokines production, histopathology, and mouse ${\beta}$-defensins (mBD) in the lungs of infected mice were evaluated. The production of cytokines in response to A. baumannii was also measured in WT and Nod1-deficient macrophages. The bacterial clearance in the lungs was not affected by Nod1 deficiency. Levels of IL-6, $TNF-{\alpha}$, and $IL-1{\beta}$ in the lung homogenates were comparable at days 1 and 3 between WT and Nod1-deficient mice, except the $TNF-{\alpha}$ level at day 3, which was higher in Nod1-deficient mice. There was no significant difference in lung pathology and expression of mBDs (mBD1, 2, 3, and 4) between WT and Nod1-deficient mice infected with A. baumannii. The production of IL-6, $TNF-{\alpha}$, and NO by macrophages in response to A. baumannii was also comparable in WT and Nod1-deficient mice. Our results indicated that Nod1 does not play an important role in host immune responses against A. baumannii infection.

• BMB Reports
• /
• v.52 no.11
• /
• pp.665-670
• /
• 2019

Nucleotide-binding oligomerization domain protein 2 (NOD2), an intracellular pattern recognition receptor, plays important roles in inflammation and cell death. Previously, we have shown that NOD2 is expressed in vascular smooth muscle cells (VSMCs) and that NOD2 deficiency promotes VSMC proliferation, migration, and neointimal formation after vascular injury. However, its role in endoplasmic reticulum (ER) stress-induced cell death in VSMCs remains unclear. Thus, the objective of this study was to evaluate ER stress-induced viability of mouse primary VSMCs. NOD2 deficiency increased ER stress-induced cell death and expression levels of apoptosis mediators (cleaved caspase-3, Bax, and Bak) in VSMCs in the presence of tunicamycin (TM), an ER stress inducer. In contrast, ER stress-induced cell death and expression levels of apoptosis mediators (cleaved caspase-3, Bax, and Bak) were decreased in NOD2-overexpressed VSMCs. We found that the $IRE-1{\alpha}-XBP1$ pathway, one of unfolded protein response branches, was decreased in NOD2-deficient VSMCs and reversed in NOD2-overexpressed VSMCs in the presence of TM. Furthermore, NOD2 deficiency reduced the expression of XBP1 target genes such as GRP78, PDI-1, and Herpud1, thus improving cell survival. Taken together, these data suggest that the induction of ER stress through NOD2 expression can protect against TM-induced cell death in VSMCs. These results may contribute to a new paradigm in vascular homeostasis.

• Biomolecules & Therapeutics
• /
• v.29 no.4
• /
• pp.410-418
• /
• 2021

Helicobacter pylori causes chronic gastritis through cag pathogenicity island (cagPAI), vacuolating cytotoxin A (VacA), lipopolysaccharides (LPS), and flagellin as pathogen-related molecular patterns (PAMPs), which, in combination with the pattern recognition receptors (PRRs) of host cells promotes the expression and secretion of inflammation-causing cytokines and activates innate immune responses such as inflammasomes. To identify useful compounds against H. pylori-associated gastric disorders, the effect of chalcone derivatives to activate the nucleotide-binding oligomerization domain (NOD)-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome was examined in an H. pylori-infected human monocytic THP-1 cell line in this study. Among the five synthetic structurally-related chalcone derivatives examined, 2'-hydroxy-4',6'-dimethoxychalcone (8) and 2'-hydroxy-3,4,5-trimethoxychalcone (12) strongly blocked the NLRP3 inflammasome in H. pylori-infected THP-1 cells. At 10 μM, these compounds inhibited the production of active IL-1β, IL-18, and caspase-1, and apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) oligomerization, but did not affect the expression levels of NLRP3, ASC, and pro-caspase-1. The interruption of NLRP3 inflammasome activation by these compounds was found to be mediated via the inhibition of the interleukin-1 receptor-associated kinase 4 (IRAK4)/IκBα/NF-κB signaling pathway. These compounds also inhibited caspase-4 production associated with non-canonical NLRP3 inflammasome activation. These results show for the first time that certain chalcones could interrupt the activation of the NLRP3 inflammasome in H. pylori-infected THP-1 cells. Therefore, these chalcones may be helpful in alleviating H. pylori-related inflammatory disorders including chronic gastritis.

• International Journal of Stem Cells
• /
• v.17 no.3
• /
• pp.309-318
• /
• 2024

Nucleotide-binding oligomerization domain 1 (NOD1), a cytosolic pattern recognition receptor protein, plays a crucial role in innate immune responses. However, the functional expression of NOD1 in mesenchymal stem cells (MSCs) derived from endometriosis remains unclear. The aim of this study was to explore the functions of NOD1 in ectopic endometrial lesions. Tissues and MSCs were isolated from both normal endometrium and endometriosis. Immunohistochemistry and real time quantitative polymerase chain reaction (RT-qPCR) were used to determine the expression of NOD1 in the tissues/MSCs. Quantification of various cytokines was performed using RT-qPCR and enzyme-linked immunosorbent assay. To confirm the proliferation, invasion/migration, and apoptotic viabilities of the samples, Cell Counting Kit-8, clonogenic formation, transwell assays, and apoptotic experiments were conducted. Higher levels of NOD1 expression were detected in the ectopic-MSCs obtained from endometriosis compared to those from the endometrium. The expression of interleukin-8 was higher in the ectopic-MSCs than in the eutopic-MSCs. Pretreatment with NOD1 agonist significantly enhanced the proliferation and invasion/migration of eutopic-MSCs. Additionally, the NOD1 inhibitor ML-130 significantly reduced the proliferation, clone formation, invasion, and migration abilities of the ectopic-MSCs, having no effect on their apoptosis capacity. Our findings suggest that the expression of NOD1 in ectopic-MSCs may contribute to the progression of ectopic endometrial lesions.

• Molecules and Cells
• /
• v.23 no.1
• /
• pp.1-10
• /
• 2007

Invading pathogens are recognized by diverse germline-encoded pattern-recognition receptors (PRRs) which are distributed in three different cellular compartments: extracellular, membrane, and cytoplasmic. In mammals, the major extracellular PRRs such as complements may first encounter the invading pathogens and opsonize them for clearance by phagocytosis which is mediated by membrane-associated phagocytic receptors including complement receptors. The major membrane-associated PRRs, Toll-like receptors, recognize diverse pathogens and generate inflammatory signals to coordinate innate immune responses and shape adaptive immune responses. Furthemore, certain membrane-associated PRRs such as Dectin-1 can mediate phagocytosis and also induce inflammatory response. When these more forefront detection systems are avoided by the pathogens, cytoplasmic PRRs may play major roles. Cytoplasmic caspase-recruiting domain (CARD) helicases such as retinoic acid-inducible protein I (RIG-I)/melanoma differentiation-associated gene 5 (MDA5), mediate antiviral immunity by inducing the production of type I interferons. Certain members of nucleotide-binding oligomerization domain (NOD)-like receptors such as NALP3 present in the cytosol form inflammasomes to induce inflammatory responses upon ligand recognition. Thus, diverse families of PRRs coordinately mediate immune responses against diverse types of pathogens.

• Journal of Ginseng Research
• /
• v.47 no.1
• /
• pp.23-32
• /
• 2023

Coronavirus disease 2019 (COVID-19) is a highly infectious respiratory disease caused by a severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). SARS-CoV-2 infection may cause clinical manifestations of multiple organ damage, including various neurological syndromes. There are currently two oral antiviral drugs-Paxlovid and molnupiravir-that are recognized to treat COVID-19, but there are still no drugs that can specifically fight the challenges of SARS-CoV-2 variants. Nucleotide-binding oligomerization domain-like receptor pyrin domain-containing-3 (NLRP3) inflammasome is a multimolecular complex that can sense heterogeneous pathogen-associated molecular patterns associated with neurological disorders. The NLRP3 activation stimulates the production of caspase-1-mediated interleukin (IL)-1β, IL-18, and other cytokines in immune cells. Panax (P.) ginseng is a medicinal plant that has traditionally been widely used to boost immunity and treat various pathological conditions in the nervous system due to its safety and anti-inflammatory/oxidant/viral activities. Several recent reports have indicated that P. ginseng and its active ingredients may regulate NLRP3 inflammasome activation in the nervous system. Therefore, this review article discusses the current knowledge regarding the pathogenesis of neurological disorders related to COVID-19 and NLRP3 inflammasome activation and the possibility of using P. ginseng in a strategy targeting this pathway to treat neurological disorders.

• Journal of Ginseng Research
• /
• v.43 no.2
• /
• pp.172-178
• /
• 2019

Inflammation is an innate immune response that protects the body from pathogens, toxins, and other dangers and is initiated by recognizing pathogen-associated molecular patterns or danger-associated molecular patterns by pattern-recognition receptors expressing on or in immune cells. Intracellular pattern-recognition receptors, including nucleotide-binding oligomerization domain-like receptors (NLRs), absent in melanoma 2, and cysteine aspartate-specific protease (caspase)-4/5/11 recognize various pathogen-associated molecular patterns and danger-associated molecular patterns and assemble protein complexes called "inflammasomes." These complexes induce inflammatory responses by activating a downstream effector, caspase-1, leading to gasdermin D-mediated pyroptosis and the secretion of proinflammatory cytokines, such as interleukin $(IL)-1{\beta}$ and IL-18. Ginsenosides are natural steroid glycosides and triterpene saponins found exclusively in the plant genus Panax. Various ginsenosides have been identified, and their abilities to regulate inflammatory responses have been evaluated. These studies have suggested a link between ginsenosides and inflammasome activation in inflammatory responses. Some types of ginsenosides, including Rh1, Rg3, Rb1, compound K, chikusetsu saponin IVa, Rg5, and Rg1, have been clearly demonstrated to inhibit inflammatory responses by suppressing the activation of various inflammasomes, including the NLRP3, NLRP1, and absent in melanoma 2 inflammasomes. Ginsenosides have also been shown to inhibit caspase-1 and to decrease the expression of $IL-1{\beta}$ and IL-18. Given this body of evidence, the functional relationship between ginsenosides and inflammasome activation provides new insight into the understanding of the molecular mechanisms of ginsenoside-mediated antiinflammatory actions. This relationship also has applications regarding the development of antiinflammatory remedies by ginsenoside-mediated targeting of inflammasomes, which could be used to prevent and treat inflammatory diseases.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2023.04a
• /
• pp.17-17
• /
• 2023

Chrysanthemum zawadskii (C. zawadskii) is used in traditional East Asian medicine for the treatment of various diseases, including inflammatory disease. However, it has remained unclear whether extracts of C. zawadskii inhibit inflammasome activation in macrophages. The present study assessed the inhibitory effect of an ethanol extract of C. zawadskii (CZE) on the activation of the inflammasome in macrophages and the underlying mechanism. Bone marrow[-derived macrophages (BMDMs) were obtained from wild-type C57BL/6 mice. The release of IL-1β and lactate dehydrogenase in response to nucleotide-binding oligomerization domain-like receptor (NLR) family pyrin domain containing 3 (NLRP3) inflammasome activators, such as ATP, nigericin and monosodium urate (MSU) crystals, was significantly decreased by CZE in lipopolysaccharide(LPS)-primed BMDMs. Western blotting revealed that CZE inhibited ATP-induced caspase-1 cleavage and IL-1β maturation. To investigate whether CZE inhibits the priming step of the NLRP3 inflammasome, we confirmed the role of CZE at the gene level using RT-qPCR. CZE also downregulated the gene expression of NLRP3 and pro-IL-1β as well as NF-κB activation in BMDMs in response to LPS. Apoptosis associated speck-like protein containing a caspase-recruitment domain (CARD) oligomerization and speck formation by NLRP3 inflammasome activators were suppressed by CZE. By contrast, CZE did not affect NLR family CARD domain containing protein 4 (NLRC4) or absent in melanoma 2 (AIM2) inflammasome activation in response to Salmonella typhimurium and poly(dA:dT) in LPS-primed BMDMs, respectively. The results revealed that three key components of CZE, namely linarin, 3,5-dicaffeoylquinic acid and chlorogenic acid, decreased IL-1β secretion in response to ATP, nigericin and MSU. These findings suggest that CZE effectively inhibited activation of the NLRP3 inflammasome.