共查询到20条相似文献,搜索用时 88 毫秒
1.
Xiujian Xu Liang Zhang Xinchun Ye Qi Hao Tao Zhang Guiyun Cui Ming Yu 《Inflammation research》2018,67(1):57-65
Objective
Current therapies for ischemia/reperfusion are insufficient because of our poor understanding of the mechanisms of brain injury after ischemic stroke. As a vital component of the innate immune system, NLRP3 inflammasome contributes to ischemic brain injury; however, a detailed understanding of their molecular mechanisms is unknown. This study was designed to investigate the effect of nuclear factor E2-related factor-2 (Nrf2) on NLRP3 inflammasome.Materials and methods
BV2 microglial cells were pretreated with tert-butylhydroquinone or Nrf2 CRISPR plasmid before oxygen–glucose deprivation/reoxygenation (OGDR) exposure. Then we observed the effect of Nrf2 on NLRP3 inflammasome.Results
We identified that Nrf2 activation inhibited NLRP3 inflammasome expression and subsequent IL-1β generation. Furthermore, the activation of NLRP3 inflammasome was sensitive to the reactive oxygen species (ROS) level and Nrf2 could decrease the production of ROS. Additionally, as a Nrf2-targeted ARE gene, NADPH quinone oxidoreductase 1 was involved in the inhibition of the NLRP3 inflammasome.Conclusion
We elucidated an inhibitory regulation of Nrf2/ARE pathway on ROS-induced NLRP3 inflammasome activation in BV2 microglial cells after OGDR exposure.2.
Wei Chen Minjie Zhao Shuzhi Zhao Qianyi Lu Lisha Ni Chen Zou Li Lu Xun Xu Huaijin Guan Zhi Zheng Qinghua Qiu 《Inflammation research》2017,66(2):157-166
Objective and design
Chronic low-grade inflammation occurs in diabetic retinopathy (DR), but the underlying mechanism(s) remains (remain) unclear. NLRP3 inflammasome activation is involved in several other inflammatory diseases. Thus, we investigated the role of the NLRP3 inflammasome signaling pathway in the pathogenesis of DR.Methods
Diabetes was induced in rats by streptozotocin treatment for 8 weeks. They were treated with NLRP3 shRNA or minocycline during the last 4 weeks. High glucose-exposed human retinal microvascular endothelial cells (HRMECs) were co-incubated with antioxidants or subjected to TXNIP or NLRP3 shRNA interference.Results
In high glucose-exposed HRMECs and retinas of diabetic rats, mRNA and protein expression of NLRP3, ASC, and proinflammatory cytokines were induced significantly by hyperglycemia. Upregulated interleukin (IL)-1β maturation, IL-18 secretion, and caspase-1 cleavage were also observed with increased cell apoptosis and retinal vascular permeability, compared with the control group. NLRP3 silencing blocked these effects in the rat model and HRMECs, confirming that inflammasome activation contributed to inflammation in DR. TXNIP expression was increased by reactive oxygen species (ROS) overproduction in animal and cell models, whereas antioxidant addition or TXNIP silencing blocked IL-1β and IL-18 secretion in high glucose-exposed HRMECs, indicating that the ROS–TXNIP pathway mediates NLRP3 inflammasome activation. Minocycline significantly downregulated ROS generation and reduced TXNIP expression, subsequently inhibited NLRP3 activation, and further decreased inflammatory factors, which were associated with a decrease in retinal vascular permeability and cell apoptosis.Conclusions
Together, our data suggest that the TXNIP/NLRP3 pathway is a potential therapeutic target for the treatment of DR, and the use of minocycline specifically for such therapy may be a new avenue of investigation in inflammatory disease.3.
Balázs Rada Jonathan J. Park Payel Sil Miklós Geiszt Thomas L. Leto 《Inflammation research》2014,63(10):821-830
Objective and design
We studied the involvement of calcium and calcium-activated NADPH oxidases in NLRP3 inflammasome activation and IL-1β release to better understand inflammasome signaling in macrophages.Material or subjects
Human volunteer blood donors were recruited to isolate monocytes to differentiate them into macrophages. Wild-type or DUOX1-deficient C57/B6 mice were used to prepare bone marrow-derived macrophages.Treatment
Murine or human macrophages were treated in vitro with NLRP3 inflammasome agonists (ATP, silica crystals) or calcium agonists (thapsigargin, ionomycin) in calcium-containing or calcium-free medium.Methods
Intracellular calcium changes were followed by measuring FURA2-based fluorescence. Gene expression changes were measured by quantitative real-time PCR. Protein expression was assessed by western blotting. Enzymatic activity was measured by fluorescence caspase-1 activity assay. IL-1β release was determined by ELISA. ELISA data were analyzed by ANOVA and Tukey’s post hoc test.Results
Our data show that calcium is essential for IL-1β release in human macrophages. Increases in cytosolic calcium alone lead to IL-1β secretion. Calcium removal blocks caspase-1 activation. Human macrophages express Duox1, a calcium-regulated NADPH oxidase that produces reactive oxygen species. However, Duox1-deficient murine macrophages show normal IL-1β release.Conclusions
Human macrophage inflammasome activation and IL-1β secretion requires calcium but does not involve NADPH oxidases. 相似文献4.
Pei-Chun Liao Louis Kuoping Chao Ju-Ching Chou Wei-Chih Dong Chien-Nan Lin Chai-Yi Lin Ann Chen Shuk-Man Ka Chen-Lung Ho Kuo-Feng Hua 《Inflammation research》2013,62(1):89-96
Objective
Reactive oxygen species (ROS) plays a critical role in the regulation of NLRP3 inflammasome activation. However, the ROS-mediated signaling pathways controlling NLRP3 inflammasome activation are not well defined.Methods
Using lipopolysaccharide (LPS) and adenosine triphosphate (ATP) activated murine macrophages as the testing model, cytokine release and protein expression were quantified by enzyme-linked immunosorbent assay and Western blot, respectively. ROS was scavenged by N-acetyl cysteine; NADPH oxidase, the major source of ROS, was inhibited by diphenyliodonium, apocynin or gp91-phox siRNA transfection; and protein kinase was inhibited by its specific inhibitor.Results
LPS-induced NLRP3 protein expression was regulated through the NADPH oxidase/ROS/NF-κB-dependent, JAK2/PI3-kinase/AKT/NF-κB-dependent, and MAPK-dependent pathways, while ATP-induced caspase-1 activation was regulated through the NADPH oxidase/ROS-dependent pathway.Conclusions
These results demonstrate that ROS regulates not only the priming stage, but also the activation stage, of NLRP3 inflammasome activation in LPS + ATP-activated macrophages. 相似文献5.
Zheng Fan Zhigang Liang Hui Yang Yuting Pan Yan Zheng Xiaomin Wang 《Journal of neuroinflammation》2017,14(1):256
Background
Emerging evidence indicates that nod-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome-induced inflammation plays a crucial role in the pathogenesis of Parkinson’s disease (PD). Thus, inhibition of NLRP3 inflammasome activation may offer a therapeutic benefit in the treatment of PD. Tenuigenin, a major active component of Polygala tenuifolia, has been shown to have potential anti-inflammatory activity, but the underlying mechanisms remain obscure.Methods
In the present study, the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD was established to explore the effect of tenuigenin on dopaminergic neurons in substantia nigra. We next activated NLRP3 inflammasome in both BV2 microglia cells and adult mice to investigate the mechanisms for the neuroprotective effect of tenuigenin.Results
We demonstrated that treatment with tenuigenin increased striatal dopaminergic levels and improved motor impairment induced by MPTP. Also, tenuigenin significantly ameliorated the degeneration of dopaminergic neurons and inhibited NLRP3 inflammasome activation in substantia nigra of MPTP mouse model. We further found that tenuigenin reduced intracellular reactive oxygen species (ROS) production and suppressed NLRP3 inflammasome activation, subsequent caspase-1 cleavage, and interleukin-1β secretion in BV2 microglia cells. These data indicate that tenuigenin inhibits the activation of NLRP3 inflammasome via downregulating ROS. Correspondingly, in vivo data showed that tenuigenin attenuates microglia activation induced by lipopolysaccharide (LPS) in substantia nigra via suppressing NLRP3 inflammasome.Conclusions
Our findings reveal that tenuigenin protects dopaminergic neurons from inflammation partly through inhibition of NLRP3 inflammasome activation in microglia, and suggest the promising clinical use of tenuigenin for PD therapy.6.
Background
NLRP3-inflammasome activation was evaluated in monocyte-derived dendritic cells (DC) obtained through IL-4 (IL4-DC) or IFN-α (IFN-DC) protocols and pulsed with chemically inactivated HIV-1. Inflammasome’ genes expression and IL-1β secretion were compared in DC isolated from 15 healthy subjects (HC) and 10 HIV-1 infected individuals (HIV+).Findings
Whether HIV was able to increased NLRP3-inflammasome genes expression and IL-1β secretion in IL4-DC from HC, the induction of inflammasome appeared significantly reduced in IFN-DC from HC, suggesting a different responsive state of IFN-DC compared to IL4-DC. No inflammasome activation was observed in IL4-DC as well as in IFN-DC derived from HIV?+?subjects, confirming previous findings on “unresponsive” state of DC derived from HIV?+?possibly due to chronic inflammatory state of these individuals.Conclusions
Our results showed that IFN-α differently modulates inflammasome expression during monocytes-DC in vitro differentiation. These findings could be of interest considering the on-going research about DC manipulation and therapeutic strategies for HIV?+?involving DC-based immune-vaccines.7.
Hiroaki Ono Ryo Ohta Yuri Kawasaki Akira Niwa Hidetoshi Takada Tatsutoshi Nakahata Shouichi Ohga Megumu K. Saito 《Inflammation research》2018,67(10):879-889
Objective
IL-1β secretion by the inflammasome is strictly controlled and requires two sequential signals: a priming signal and an activating signal. Lysosomal membrane permeabilization (LMP) plays a critical role in the regulation of NLRP3 inflammasome, and generally acts as an activating signal. However, the role of LMP controlling NLRP3 inflammasome activation in human vascular smooth muscle cells (hVSMCs) is not well defined.Methods
LMP was induced in hVSMCs by Leu-Leu-O-methyl ester. Cathepsin B was inhibited by CA-074 Me. Cytokine release, mRNA, and protein were quantified by enzyme-linked immunosorbent assay, quantitative PCR, and Western blot, respectively. NF-κB activity was analyzed by immunostaining of the NF-κB p65 nuclear translocation and using the dual-luciferase reporter assay system.Results
LMP had both priming and activating roles, causing an upregulation of proIL-1β and NLRP3 and the secretion of mature IL-1β from unprimed hVSMCs. LMP activated the canonical NF-κB pathway. The priming effect of LMP was inhibited by CA-074 Me, indicating an upstream role of cathepsin B.Conclusions
These data support a novel role of LMP as a single stimulus for the secretion of IL-1β from hVSMCs, implying the possibility that hVSMCs are an important initiator of the sterile inflammatory response caused by lysosomal disintegration.8.
Hong Wang Mingqiang Hua Shukang Wang Jie Yu Chen Chen Xueyun Zhao Chen Zhang Chaoqin Zhong Ruiqing Wang Na He Ming Hou Daoxin Ma 《Inflammation research》2017,66(3):249-258
Background
Though the pathogenesis of AML is still unknown, accumulating evidence revealed that immune response plays a vital part in it. NLRP3 inflammasome as a component of immune system has been found related to several cancers. The single nucleotide polymorphisms (SNPs) of NLRP3 inflammasome genes may be related to pathogenesis and prognosis of AML.Methods and results
We determined polymorphisms of NLRP3 (rs35829419), CARD8 (rs2043211), IL-1β (rs16944), IL-18 (rs1946518) and NF-κB ?94 ins/del ATTG in de novo AML patients to find out whether they play roles in the susceptibility and severity of AML. In our study, 383 AML cases and 300 randomly selected healthy individuals were examined for the polymorphisms and expression of NLRP3 genes. IL-1β (rs16944) polymorphism in different risk AML subgroups was found statistically different, with more GA genotype in favorable-risk cytogenetics group. We also demonstrated that the bone marrow blasts of patients carrying IL-18 (rs1946518) GG or GT genotype were higher than patients of TT genotype. IL-18 plasma level of patients with IL-18 (rs1946518) GT or TT genotype was higher than GG genotype. Moreover, the GT genotype of IL-18 (rs1946518) led to statistically poorer AML-specific survival.Conclusion
IL-1β (rs16944) and IL-18 (rs1946518) may be served as potential predictors for AML.9.
Yohei Yamaguchi Tomoko Kurita-Ochiai Ryoki Kobayashi Toshihiko Suzuki Tomohiro Ando 《Inflammation research》2017,66(1):59-65
Objective
Porphyromonas gingivalis is involved in the pathogenesis of chronic inflammatory periodontal disease. Recent studies have suggested that the NLRP3 inflammasome plays an important role in the development of chronic inflammation. We investigated a possible association between the inflammasome in gingival inflammation and bone loss induced by P. gingivalis infection using NLRP3-deficient mice.Methods
Wild-type and NLRP3-deficient mice were injected orally with P. gingivalis. We assessed alveolar bone loss, expression of pro-interleukin (IL)-1β, pro-IL-18, receptor activator of nuclear factor kappa-B ligand (RANKL), and osteoprotegerin (OPG) in gingival tissue, as well as IL-1β, IL-18, and IL-6 production and caspase-1 activity in peritoneal macrophages.Results
Porphyromonas gingivalis challenge significantly increased alveolar bone loss; gingival gene expression of pro-IL-1β, pro-IL-18, and RANKL; production of IL-1β, IL-18, and IL-6; and caspase-1 activity in peritoneal macrophages of wild-type mice, but did not affect NLRP3-deficient mice. Meanwhile, OPG mRNA expression in gingival tissue and peritoneal IL-6 production were significantly higher in NLRP3-knockout mice.Conclusions
Porphyromonas gingivalis activated innate immune cells via the NLRP3 inflammasome. These results suggest that the NLRP3 inflammasome, followed by a response from the IL-1 family, is critical in periodontal disease induced by wild-type P. gingivalis challenge via sustained inflammation.10.
《Immunobiology》2017,222(3):552-561
NLRP3 inflammasome not only functions as a critical effector in innate immunity, but also triggers the production of proinflammatory cytokines involved in inflammation-associated diseases. Sirtuin 1 (SIRT1) plays an important role in the regulation of cellular inflammation. However, whether the activation of NLRP3 inflammasome is regulated by SIRT1 remains unknown. In this study, we investigated the regulatory effect of SIRT1 on NLRP3 inflammasome and the underlying mechanisms. We found that lipopolysaccharide (LPS) and adenosine triphosphate (ATP)-induced the activation of NLRP3 inflammasome in human umbilical vein endothelial cells (HUVECs). Activation of SIRT1 inhibited NLRP3 inflammasome activation and subsequent caspase-1 cleavage as well as interleukin (IL)-1β secretion, whereas SIRT1 knockdown obviously enhanced the activation of NLRP3 inflammasome in HUVECs. Importantly, gene silencing of SIRT1 abrogated the inhibitory effect of SIRT1 activator on NLRP3 inflammasome formation and IL-1β production in HUVECs stimulated with LPS plus ATP. Further study indicated that cluster of differentiation 40 (CD40) may be involved in the regulation of NLRP3 inflammasome by SIRT1. In vivo studies indicated that implantation of the periarterial carotid collar increased the arterial expression levels of CD40 and CD40 Ligand (CD40L), but inhibited arterial SIRT1 expression in the rabbits. Moreover, treatment with SIRT1 activator decreased CD40 and CD40L levels in collared arteries. Meanwhile, serum IL-1β level, the marker of inflammasome activation, was also inhibited by SIRT1 activation. Taken together, these findings revealed a novel regulatory mechanism of NLRP3 inflammasome by SIRT1, which may be related to suppression of CD40. 相似文献
11.
Extracellular adenosine triphosphate (ATP) is a second signal for the assembly of the NLR family, pyrin domain-containing 3 (NLRP3) inflammasome, which form a framework to activate caspase 1, leading to the processing and secretion of the pro-inflammatory cytokine interleukin-1β (IL-1β). The aim of the present study was to investigate the role of the ATP-gated ion channel subtype P2X7 receptor in the inflammasome activation of bovine monocytes. ATP-induced inflammasome assembly in bovine monocytes was shown by caspase-1 activation and the release of IL-1β by LPS/ATP-stimulated bovine cells. The IL-1β release depended on potassium efflux but was independent of reactive oxygen generation of bovine monocytes. Unlike in the human system, a P2X7 receptor antagonist did not block the ATP-induced release of IL-1β of LPS-primed bovine cells. P2X7 mediated pore formation was observed in subsets of bovine T lymphocytes (CD4+>CD8+) but not in monocytes. In addition, ATP and 2-MeSATP but not the high affinity P2X7 agonist BzATP induced calcium influx in bovine monocytes. The data indicate that ROS generation plays no role in the ATP-induced activation of inflammasome in bovine monocytes and that P2X7-mediated pore formation is not necessary for the release of Interleukin-1β. 相似文献
12.
Sung Hee Jang Soonok Cho Eung-Seok Lee Jung Mogg Kim Hyeyoung Kim 《Inflammation research》2013,62(7):689-696
13.
Background
Various microbial, inflammatory and immune signals regulate the activation of dendritic cells (DC), determining their ability to interact with naïve T cells and to produce cytokines that direct T cell development. In particular, CD40L and IL-1 cooperatively activate DC to secrete high levels of IL-12. The immuno-stimulatory capacity of such DC is otherwise not well-defined prompting further characterization of the effects of IL-1 and family members on DC activation in comparison with other pro-inflammatory stimuli.Results
Human DC co-activated in vitro by CD40L and IL-1β expressed numerous cytokine genes including IL-12β, IL-23 p19, IL-1β, IL-1α, IL-1Ra, IL-10, IL-6, IL-18 and IFN-γ. These DC produced high levels of IL-12 protein and appeared capable of producing IFN-γ. Potent CD4+ and CD8+ T cell-stimulatory properties were acquired by DC under conditions that also induced IL-12. Notably, these DC induced rapid differentiation of fluMP-specific CD8+ T cells. Molecules related to IL-1β, like IL-1α, co-induced IL-12 secretion whereas IL-18 did not. Conversely, the inhibitor IL-1Ra, produced endogenously by DC curtailed IL-12 production in response to CD40L.Conclusions
IL-1 and IL-1Ra play a biologically-relevant role in the positive and negative regulation of DC activation. In conjunction with CD40L, IL-1 sends a powerful activation signal to DC that could be distinguished from other modes of activation. This signal enables the production of pro-inflammatory cytokines by DC, and enhances the differentiation of naïve T cells into effectors of type-1 cellular immune responses. 相似文献14.
Paraquat can result in dysfunction of multiple organs after ingestion in human. However, the mechanisms of nucleotide-binding domain and leucine-rich repeat containing protein 3 (NLRP3) inflammasome activation in acute kidney injury have not been clearly demonstrated. The aim of this study was to determine the effect of NLRP3 inflammasome activation and its regulation by nuclear factor-kappa B (NF-κB) and death-associated protein kinase (DAPK). Male Wistar rats were treated with intraperitoneal injection of paraquat at 20 mg/kg, and NF-κB inhibitor BAY 11-7082 was pretreated at 10 mg/kg 1 h before paraquat exposure. Additionally, rat renal tubular epithelial cells (NRK-52E) were transfected with small interfering RNA (siRNA) against DAPK to evaluate its role in NLRP3 inflammasome activation. DAPK and NLRP3 inflammasome were evaluated by immunohistochemistry staining or Western blot; the pro-inflammatory cytokines including tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and interleukin-18 (IL-18) were measured via ELISA. The results showed that NF-κB, DAPK, and NLRP3 inflammasome were activated in paraquat (PQ)-treated rat kidney; the secretion of pro-inflammatory cytokines was significantly increased. These toxic effects were attenuated by NF-κB inhibitor. Besides, the activation of NLRP3 inflammasome and secretion of IL-1β and IL-18 in paraquat-treated rat renal tubular epithelial cells were inhibited by siRNA against DAPK. In conclusion, NLRP3 inflammasome activation regulated by NF-κB and DAPK played an important role in paraquat-induced acute kidney injury. 相似文献
15.
Xiaolong Pan Xiang Cao Na Li Yimiao Xu Qiuyue Wu Jing Bai Zhimin Yin Lan Luo Lei Lan 《Inflammation research》2014,63(7):597-608
Objective
Forsythin (FOR) is an active ingredient extracted from the fruit of the medicinal plant Forsythia suspensa (Thunb.) Vahl. Here, we investigated the effect of FOR on LPS-induced inflammatory response and the underlying molecular mechanisms in RAW264.7 macrophages.Materials and methods
RAW264.7 cells were pre-treated with or without FOR and then stimulated with or without LPS. The productions of TNF-α, IL-1β, IL-6, PGE2 and NO were determined by ELISA and nitrite analysis, respectively. The expressions of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were measured by Western blotting and RT-PCR analysis. The activations of signaling molecules were detected by Western blotting using phosphorylation specific antibodies. Reactive oxygen species (ROS) production was determined by ROS assay.Results
LPS-induced productions of IL-1β, IL-6, TNF-α, NO and PGE2 were inhibited by FOR in a dose-dependent manner. FOR also suppressed the LPS-elevated expressions of iNOS and COX-2. Further investigations revealed that FOR significantly inhibited the LPS-induced activations of JAK-STATs and p38 MAPKs, but not of IKKα/β in LPS-stimulated RAW264.7 cells. Additionally, FOR interfered with both JAK-STATs and p38 MAPKs signaling pathways to modulate the expressions of IL-1β, IL-6, TNF-α, iNOS and COX-2. Furthermore, FOR reduced the LPS-induced ROS accumulation, validating that FOR serves as an antioxidant.Conclusions
Our data suggested that FOR exerts anti-inflammatory action, at least in part, via suppressing LPS-induced activation of JAK-STATs and p38 MAPKs signalings and production of ROS in macrophage cells. 相似文献16.
Angèle Nalbandian Arif A. Khan Ruchi Srivastava Katrina J. Llewellyn Baichang Tan Nora Shukr Yasmin Fazli Virginia E. Kimonis Lbachir BenMohamed 《Inflammation》2017,40(1):21-41
Aberrant activation of the NOD-like receptor (NLR) family, pyrin domain-containing protein 3 (NLRP3) inflammasome, triggers a pathogenic inflammatory response in many inherited neurodegenerative disorders. Inflammation has recently been associated with valosin-containing protein (VCP)-associated diseases, caused by missense mutations in the VCP gene. This prompted us to investigate whether NLRP3 inflammasome plays a role in VCP-associated diseases, which classically affects the muscles, bones, and brain. In this report, we demonstrate (i) an elevated activation of the NLRP3 inflammasome in VCP myoblasts, derived from induced pluripotent stem cells (iPSCs) of VCP patients, which was significantly decreased following in vitro treatment with the MCC950, a potent and specific inhibitor of NLRP3 inflammasome; (ii) a significant increase in the expression of NLRP3, caspase 1, IL-1β, and IL-18 in the quadriceps muscles of VCPR155H/+ heterozygote mice, an experimental mouse model that has many clinical features of human VCP-associated myopathy; (iii) a significant increase of number of IL-1β(+)F4/80(+)Ly6C(+) inflammatory macrophages that infiltrate the muscles of VCPR155H/+ mice; (iv) NLRP3 inflammasome activation and accumulation IL-1β(+)F4/80(+)Ly6C(+) macrophages positively correlated with high expression of TDP-43 and p62/SQSTM1 markers of VCP pathology in damaged muscle; and (v) treatment of VCPR155H/+ mice with MCC950 inhibitor suppressed activation of NLRP3 inflammasome, reduced the F4/80(+)Ly6C(+)IL-1β(+) macrophage infiltrates in the muscle, and significantly ameliorated muscle strength. Together, these results suggest that (i) NLRP3 inflammasome and local IL-1β(+)F4/80(+)Ly6C(+) inflammatory macrophages contribute to pathogenesis of VCP-associated myopathy and (ii) identified MCC950 specific inhibitor of the NLRP3 inflammasome with promising therapeutic potential for the treatment of VCP-associated myopathy. 相似文献
17.
Objective
We investigated the effect of IL-1β on the development of intestinal epithelial stem cells.Materials and methods
Normal intestinal epithelial cell line IEC-18 cells were cultured in the presence or absence of 200?pM of IL-1β in serum-free medium (SFM) for various time periods. The effects of IL-1β on intestinal stem cell self-renewal and IEC-18 cell proliferation were evaluated by a colony formation assay, MTT assay, and a focus formation assay. The expression of stemness genes including Bmi-1, Lgr-5, c-myc, Nanog, and β-catenin in IEC-18 cells were measured by quantitative PCR and western blot analysis.Results
IEC-18 cells grew as a monolayer in SFM in the absence of IL-1β. Cellular spheres were formed when IEC-18 cells were grown in SFM in the presence of IL-1β. IL-1β induced the development of large colonies in the soft-agar as well as the formation of foci when IEC-18 cells were cultured in type-I collagen-coated plates. The expression of Bmi-1, Lgr-5, c-myc, Nanog, and β-catenin were significantly increased in IEC-18 cells treated with IL-1β.Conclusion
Our studies provide direct evidence the IL-1β may play an important role in the self-renewal of intestinal epithelial stem cells and the development of cancer stem cells. 相似文献18.
An inflammasome is a multiprotein complex that serves as a platform for caspase-1 activation and caspase-1-dependent proteolytic maturation and secretion of interleukin-1β (IL-1β). Though a number of inflammasomes have been described, the NLRP3 inflammasome is the most extensively studied but also the most elusive. It is unique in that it responds to numerous physically and chemically diverse stimuli. The potent proinflammatory and pyrogenic activities of IL-1β necessitate that inflammasome activity is tightly controlled. To this end, a priming step is first required to induce the expression of both NLRP3 and proIL-1β. This event renders the cell competent for NLRP3 inflammasome activation and IL-1β secretion, and it is highly regulated by negative feedback loops. Despite the wide array of NLRP3 activators, the actual triggering of NLRP3 is controlled by integration a comparatively small number of signals that are common to nearly all activators. Minimally, these include potassium efflux, elevated levels of reactive oxygen species (ROS), and, for certain activators, lysosomal destabilization. Further investigation of how these and potentially other as yet uncharacterized signals are integrated by the NLRP3 inflammasome and the relevance of these biochemical events in vivo should provide new insight into the mechanisms of host defense and autoinflammatory conditions. 相似文献
19.
Min Xia Krishna M. Boini Justine M. Abais Ming Xu Yang Zhang Pin-Lan Li 《The American journal of pathology》2014,184(5):1617-1628
Inflammasomes serve as an intracellular machinery to initiate inflammatory response to various danger signals. The present study tested whether an inflammasome centered on nucleotide oligomerization domain-like receptor protein 3 (NLRP3) triggers endothelial inflammatory response to adipokine visfatin, a major injurious adipokine during obesity. NLRP3 inflammasome components were abundantly expressed in cultured mouse microvascular endothelial cells, including NLRP3, apoptosis-associated speck-like protein, and caspase-1. These NLRP3 inflammasome molecules could be aggregated to form an inflammasome complex on stimulation of visfatin, as shown by fluorescence confocal microscopy and size exclusion chromatography. Correspondingly, visfatin significantly increased caspase-1 activity and IL-1β release in microvascular endothelial cells, indicating an activation of NLRP3 inflammasomes. In animal experiments, direct infusion of visfatin in mice with partially ligated left carotid artery were found to have significantly increased neointimal formation, which was correlated with increased NLRP3 inflammasome formation and IL-1β production in the intima. Further, visfatin-induced neointimal formation, endothelial inflammasome formation, and IL-1β production in mouse partially ligated left carotid artery were abolished by caspase-1 inhibition, local delivery of apoptosis-associated speck-like protein shRNA or deletion of the ASC gene. In conclusion, the formation and activation of NLRP3 inflammasomes by adipokine visfatin may be an important initiating mechanism to turn on the endothelial inflammatory response leading to arterial inflammation and endothelial dysfunction in mice during early stage obesity.Obesity is a major risk factor for cardiovascular disease and has been strongly associated with endothelial dysfunction and coronary atherosclerosis. Obese patients have significantly elevated morbidity and mortality due to coronary artery disease.1 However, weight loss can decrease cardiovascular risk, improve endothelial function, and protect coronary arteries from atherosclerotic injury. However, mechanisms underlying obesity-associated coronary atherosclerotic injury and endothelial dysfunction are not fully understood. Numerous studies have reported a critical role of vascular inflammation in the development of coronary atherosclerosis, which has been characterized as an inflammatory disease.2–6 To date, the precise mechanism that mediates the early inflammatory responses of endothelial cells (ECs) during obesity remains unknown.Recently, the inflammasome as an intracellular inflammatory machinery has been reported to switch on the inflammatory response of tissues or organs to various danger signals.7,8 Among different types of inflammasomes, the nucleotide oligomerization domain (Nod)-like receptor family pyrin domain containing 3 (NLRP3) inflammasome is well characterized in a variety of mammalian cells, especially as a receptor for endogenous danger signals such as ATP, cholesterol crystal, β-amyloid, and monosodium urate.2,9–14 The NLRP3 inflammasome is characteristic of a proteolytic complex mainly composed of NLRP3, the adaptor protein apoptosis-associated speck-like protein (ASC), and caspase-1. On stimulation, NLRP3 inflammasomes oligomerize to form large multimolecular complexes that control the caspase-1 activity and subsequent bioactive IL-1β production.10,15–18 More recently, NLRP3 inflammasomes have been implicated in the development of obesity and insulin resistance.11 For example, the consumption of a high-fat diet (HFD) has been considered as critical contributor to type 2 diabetes, and NLRP3 inflammasome might be an important pathway of HFD mediating insulin resistance leading to inflammation.19 These findings led us to wonder whether activation of NLRP3 inflammasome is an initiating mechanism for obesity-induced endothelial inflammatory responses.Adipose tissue as an active metabolic tissue secretes multiple metabolically important proteins known as ‘adipokines.''20,21 Visfatin is a newly identified adipokine and a major injurious factor during obesity-associated diseases, including diabetes,22 carotid and coronary atherosclerosis,23,24 and chronic kidney disease.25,26 Visfatin has also been considered as a pro-inflammatory adipokine to promote endothelial inflammation and injury.27,28 The present study was designed to test the hypothesis that activation of NLRP3 inflammasomes is one of the important mechanisms that mediate endothelial inflammatory response to visfatin during early-stage obesity. We used a series of molecular and physiological approaches both in vitro and in vivo to test this hypothesis. 相似文献
20.
Li Gao Qing Dong Zhenghong Song Fei Shen Jianquan Shi Yansheng Li 《Inflammation research》2017,66(1):17-24