Objective:To evaluate the effects of Capsosiphon fulvescens(C.fulvescens)ethanolic extract on inflammation in lipopolysaccharide(LPS)-induced RAW296.7 macrophages.Methods:The protective effects of C.fulvescens ethanol...Objective:To evaluate the effects of Capsosiphon fulvescens(C.fulvescens)ethanolic extract on inflammation in lipopolysaccharide(LPS)-induced RAW296.7 macrophages.Methods:The protective effects of C.fulvescens ethanolic extract on LPS-induced inflammation in RAW264.7 macrophages were assessed using biochemical analysis,including enzyme-linked immunosorbent assay,quantitative reverse transcription-polymerase chain reaction,and Western blot analysis.To examine reactive oxygen species(ROS)production,flow cytometry analysis,and immunofluorescence staining were used.Furthermore,the modulatory effect of C.fulvescens ethanolic extract on NF-κB activation was investigated.Results:C.fulvescens ethanolic extract significantly attenuated LPS-induced levels of pro-inflammatory cytokines and notably reduced the secretion and mRNA levels of LPS-mediated matrix metalloproteinases.In addition,C.fulvescens ethanolic extract decreased ROS production and suppressed the TLR4/NF-κB signaling pathway.Conclusions:C.fulvescens ethanolic extract alleviates inflammation as well as oxidative stress by modulating the TLR4/NF-κB signaling in LPS-induced RAW264.7 macrophages.C.fulvescens can be used as a potential therapeutic agent to suppress inflammation and oxidative stress-associated diseases.展开更多
The relationship between intracelluar trypsinogen activation and NF-κB activation in rat pancreatic acinar cells induced by M3 cholinergic receptor agonist （carbachol） hyperstimulation was studied. Rat pancreatic a...The relationship between intracelluar trypsinogen activation and NF-κB activation in rat pancreatic acinar cells induced by M3 cholinergic receptor agonist （carbachol） hyperstimulation was studied. Rat pancreatic acinar cells were isolated, cultured and treated with carbachol, the active protease inhibitor （pefabloc） and NF-κB inhibitor （PDTC） in vitro. Intracelluar trypsin activity was measured by using a fluorogenic substrate. The activity of NF-κB was monitored by using electrophoretic mobility shift assay. The results showed that after pretreatment with 2 mmol/L pefabloc, the activities of trypsin and NF-κB in pancreatic acinar cells treated with high concertrations of carbachol （10^-3 mol/L） in vitro was significantly decreased as compared with control group （P〈0.01 ）. The addition of 10^-2 mol/L PDTC resulted in a significant decrease of NF-κB activities in pancreatic acinar cells after treated with high concertrations of carbachol （10^-3 mol/L） in vitro, but the intracelluar trypsinogen activity was not obviously inhibited （P〉0.05）. It was concluded that intracelluar trypsinogen activation is likely involved in the regulation of high concertrations of carbachol-induced NF-κB activation in pancreatic acinar cells in vitro. NF-κB activation is likely not necessary for high concertrations of carbachol-induced trypsinogen activation in pancreatic acinar cells in vitro.展开更多
AIM： Different strains of bifidobacteria were analysed for their effects on HT-29 intestinal epithelial cells （IECs） in in vitro models both of the non-inflamed and inflamed intestinal epithelium. METHODS： A repor...AIM： Different strains of bifidobacteria were analysed for their effects on HT-29 intestinal epithelial cells （IECs） in in vitro models both of the non-inflamed and inflamed intestinal epithelium. METHODS： A reporter gene system in HT-29 cells was used to measure levels of NF-KB activation after challenge with bifidobacteria or after bacterial pre-treatment following LPS challenge. IL-8 protein and pro-inflammatory gene expression was investigated using normal HT-29 cells. RESULTS： None of the bifidobacteria tested induced activation of nuclear factor κB （NF-κB） indicating that bifidobacteria themselves do not induce inflammatory events in IECs. However, six out of eight bifidobacteria tested inhibited lipopolysaccharide- （LPS-） induced NF-κB activation in a dose- and strain-dependent manner. In contrast, NF-κB activation in response to challenge with tumor necrosis factor-α （TNF-α） was affected by none of the tested bifidobacteria, indicating that the inhibitory effect of bifidobacteria is specific for LPS-induced inflammation in IECs. As shown with two of the six inhibitionpositive bifidobacteria, LPS-induced inhibition of NF-κB activation was accompanied by a dose-dependent decrease of interleukin 8 （IL-8） secretion and by lower mRNA levels for IL-8, TNF-α, cyclooxygenase 2 （Cox-2）, and intercellular adhesion molecule 1（ICAM-1）. CONCLUSION： Some strains of bifidobacteria are effective in inhibiting LPS-induced inflammation and thus might be appropriate candidates for probiotic intervention in chronic intestinal inflammation.展开更多
Objective: To explore the characteristics of NF-闎 activation in the progress of pancreatitis, the relationship with expression of TNF- in the inflammatory reaction, and prevent the exacerbation of pancreatitis by usi...Objective: To explore the characteristics of NF-闎 activation in the progress of pancreatitis, the relationship with expression of TNF- in the inflammatory reaction, and prevent the exacerbation of pancreatitis by using NAC. Method: Forty-eight rats were divided into three groups: therapy (group C), pancreatitis (group B) and control (group A). NAC served as the inhibitor of NF-闎 activation. In the time intervals of 1.5, 3.0, 6.0, 12.0 hour, NF-闎 activation was detected with flow cytometry (FCM) and the expression of TNF- mRNA and protein with in situ hybridization (ISH) and enzyme-linked immuno-sorbent assay (ELISA) respectively. Meanwhile, the level of lipase and amylase in the serum was assayed and the pathological change was evaluated. Result: NF-闎 activation in the pancreatitis group was higher than that in the control group (P<0.01), peaked at 3 hours, and was depressed by the inhibitor of NF-闎, NAC. The expression of TNF- as well as the level of lipase and amylase in the serum also rose synchronously with activation of NF-闎. In contrast to group A, it was significantly different (P<0.01) in group B. After using NAC in group C, all of these values were decreased and the in-flammatory reaction in the pancreas abated evidently. The pathology changes of the pancreas were shown to be alleviated in group C. Conclusion: First, NF-闎 activity is intensively initiated in the course of pancreatitis and shown to have closely relationship with the release of cytokines. Second, use of NAC markedly depressed NF-闎 activation. TNF- expression is down regulated by cytokines. It is suggested that NAC probably acts as a useful agent for treatment of pancreatitis by indirectly inhibiting activation of NF-闎.展开更多
AIM: To investigate the effect of Tetrandrine (Tet) on LPS-induced NF-κB activation and cell injury in pancreatic acinar cells and to explore the mechanism of Tetrandrine preventing LPS-induced acinar cell injury. ME...AIM: To investigate the effect of Tetrandrine (Tet) on LPS-induced NF-κB activation and cell injury in pancreatic acinar cells and to explore the mechanism of Tetrandrine preventing LPS-induced acinar cell injury. METHODS: Male rat pancreatic acinar cells were isolated by collagenase digestion, then exposed to LPS (10 mg/L), Tet (50μmol/L, 100μmol/L) or normal media. At different time point (30 min, 1 h, 4 h, 10 h) after treatment with the agents, cell viability was determined by MTT, the product and nuclear translocation of subunit p65 of NF-κB was visualized by immunofluorescence staining and nuclear protein was extracted to perform EMSA which was used to assay the NF-κB binding activity. RESULTS: LPS induced cell damage directly in a time dependent manner and Tet attenuated LPS-induced cell damage (50μmol/L, P < 0.05; 100μmol/L, P < 0.01). NF-κB p65 immunofluorescence staining in cytoplasm increased and began showing its nuclear translocation within 30 min and the peak was shown at 1 h of LPS 10 mg/L treatment. NF-κB DNA binding activity showed the same alteration pattern as p65 immunofluorescence staining. In Tet group, the immunofluorescence staining in cytoplasm and nuclear translocation of NF-κB were inhibited significantly. CONCLUSION: NF-κB activation is an important early event that may contribute to inflammatory responses and cell injury in pancreatic acinar cells. Tet possesses the protective effect on LPS-induced acinar cell injury by inhibiting NF-κB activation.展开更多
Nuclear factor-κB(NF-κB), a transcription factor, which plays a pivotal role in the expression of a wide variety of genes, involves in systemic inflammatory response syndrome and is the new target for therapy. To ex...Nuclear factor-κB(NF-κB), a transcription factor, which plays a pivotal role in the expression of a wide variety of genes, involves in systemic inflammatory response syndrome and is the new target for therapy. To explore the effects and mechanism of lanthanum on nuclear translocation of NF-κB in macrophage of mice(Mφ), fluorescent antibody technique, western blotting and ELISA(enzyme-linked immunosorbent assay) were employed. Mφ were divided into five groups at random: one was the control group, in which the cells were cultured in medium without any stimulation, one was LPS (lipopolysaccharide) group, in which the cells were incubated with 1 μg·ml -1 LPS for 30 min and one was LaCl_3 group, in which cells were incubated with 2.5 μm of lanthanum chloride for 30 min. The forth group was named as LaCl_3+LPS group, in which cells were incubated with 2.5 μm of lanthanum chloride for 30 min before stimulated with LPS(1 μg·ml -1, 30 min), and the fifth group was known as LaCl_3/LPS group, in which the cells were cultured in medium containing 2.5 μm of lanthanum chloride at first, then the cells were incubated with LPS(1 μg·ml -1, 30 min) after lanthanum chloride was removed from the media. The location of NF-κB p65 subunit (NF-κB/p65) in Mφ was detected by immunofluorescence and fluorescence microscope. The activation of NF-κB/P65 in nuclei was detected by TransAM TM NF-κB/P65 Transcription Factor assay kit. Meanwhile, the expression of NF-κB/p65 in nuclei and that of IκBα in cytoplasm were measured by Western blotting analysis. The majority of FITC-labeled NF-κB/p65 was located in the nuclei stimulated with LPS. However, there was less fluorescence seen in the nuclei of control group, LaCl_3 group, LaCl_3 + LPS group and LaCl_3/LPS group. Compared with LPS group, the IκBα protein level in cytoplasm increase in LaCl_3 group, LaCl_3+LPS group and LaCl_3/LPS group. The expression and activation of nuclei p65 protein decrease significantly in LaCl_3 group, LaCl_3+LPS group and LaCl_3/LPS group, compare with LPS group. All the results indicate that lanthanum inhibits the nuclear translocation of NF-κB induce by LPS, and the effects are partly due to the upregulation of IκB.展开更多
Staphylococcus aureus （S. aureus） is an important human pathogen which can cause a chronic condition with a high relapse rate despite the aggressive antimicrobial treatment. Recent studies showed that intracellular ...Staphylococcus aureus （S. aureus） is an important human pathogen which can cause a chronic condition with a high relapse rate despite the aggressive antimicrobial treatment. Recent studies showed that intracellular pattern recognition receptors （including NOD） in response to bacteria or bacterial products play a proinflammatory role by activating nuclear transcription factor-κB （NF-κB）. But how NOD2 mediates the proinflammatory response to S. aureus in mast cells （MCs） is unclear. So, in this study, we attempted to examine the role of NOD2 in inflammatory responses of MCs to S. aureus. P815 cells （a mouse mast cell line） were cultured. Real-time PCR was used to detect the NOD2 mRNA expression in P815 cells during S. aureus infection. The siRNA against NOD2 gene was synthesized and transfected into S. aureus-infected P815 cells. By using the methods of ELISA and flow cytometry, the effects of NOD2 gene silencing on cell phagocytosis, cytokine secretion, NF-κB activation and cell apoptosis of the S. aureus-infected P815 cells were examined. It was found that S. aureus infection could increase the expression of NOD2 mRNA in P815 cells. NOD2 gene interference in P815 cells reduced the number of S. aureus engulfed by P815 cells, the level of cytokines and the activation of NF-κB. In addition, S. aureus could induce the apoptosis of P815 cells, but NOD2 gene silencing did not affect the cell apoptosis rate. Our data suggested that NOD2 plays a key role in pathogen recognition, signal transduction, and NF-κB activation in the inflammatory responses of MCs infected by S. aureus.展开更多
AIM： To analyze the effects of NF-kB inhibition by antioxidant pyrrolidine dithiocarbamate （PDTC） or TNF inhibitor pentoxifylline （PTX） on liver regeneration after partial hepatectomy （PH）. METHODS： Saline, PD...AIM： To analyze the effects of NF-kB inhibition by antioxidant pyrrolidine dithiocarbamate （PDTC） or TNF inhibitor pentoxifylline （PTX） on liver regeneration after partial hepatectomy （PH）. METHODS： Saline, PDTC or PTX were injected 1 h before PH and rats were killed at 0.5 and 24 h after PH. Several control groups were used for comparison （injection control groups）. RESULTS： Compared to saline injected controls, NF-kB activation was absent 0.5 h after PH in rats treated with PDTC or PTX. At 24 h after PH, DNA synthesis and PCNA expression were identical in treated and control rats and thus occurred irrespectively of the status of NF-kB activation at 0.5 h. Signal transducer and activator of transcription 3 （Stat3） acUvatJon was observed already 0.5 h after PH in saline, PDTC or PTX group and was similar to Stat3 activation in response to injection without PH. CONCLUSION： These data strongly suggest that （1） NF-kB p65/p50 DNA binding produced in response to PH is not a signal necessary to initiate the liver regeneration, （2） star3 activation is a stress response unrelated to the activation of NF-kB. In conclusion, NF-kB activation is not critically required for the process of liver regeneration after PH.展开更多
Summary: To investigate the effect of N-tosyl-L-phenylalanylchloromethyl ketone (TPCK) on tumor necrosis factor-alpha-induced NF-κB activation and apoptosis in U937 cell line, changes and subcellular localization of ...Summary: To investigate the effect of N-tosyl-L-phenylalanylchloromethyl ketone (TPCK) on tumor necrosis factor-alpha-induced NF-κB activation and apoptosis in U937 cell line, changes and subcellular localization of NF-κB/p65 and IκB-α were observed by fluorescencemicroscopy and expression and degradation of IκB-α by flow cytometry. The apoptosis of U937 cells was measured by flow cytometry and electrophoresis of DNA. Immunolfluorescence assay showed that NF-κB/p65, IκB-α only localized in cytoplasm. After TNF-α stimulation, p65 was localized only in nuclei, and IκB-α was only localized in cytoplasm and decreased. The changes of TNF-α stimulation were specifically inhibited by TPCK. Flow cytometry also revealed the downregulation of IκB-α protein during TNF-α-induced apoptosis and the down-regulation was specifically inhibited by TPCK. Flow cytometry also showed the apoptosis of U937 cells after TNF-α induction. DNA ladder can be detected in cells treated by TNF-α. It is concluded that degradation of IκB-α protein and NF-κB/p65 translocation occur during TNF-α-induced apoptosis of U937 cells, suggesting the activation of NF-κB. TPCK-sensitive protease plays an important role in the degradation of IκB-α protein induced by TNF-α in U937 cells. TPCK sensitive protease also plays an important role in the apoptosis of U937 cells induced by TNF-α.展开更多
The relationship between M3 cholinergic receptor agonist （carbachol） hyperstimulationinduced pancreatic acinar cellular injury and trypsinogen activation or NF-κB activation in rats was studied in vitro. Rat pancre...The relationship between M3 cholinergic receptor agonist （carbachol） hyperstimulationinduced pancreatic acinar cellular injury and trypsinogen activation or NF-κB activation in rats was studied in vitro. Rat pancreatic acinar ceils were isolated, cultured and treated with carbachol, the active protease inhibitor （pefabloc）, and NF-κB inhibitor （PDTC） in vitro. Intracellular trypsin activity was measured by using a fluorogenic substrate. The cellular injury was evaluated by measuring the leakage of LDH from pancreatic acinar ceils. The results showed that as compared with control group, 10-3 mol/L carbachol induced a significant increase of the intracellular trypsin activity and the leakage of LDH from pancreatic acinar cells. Pretreatment with 2 mmol/L pefabloc could significantly decrease the activity of trypsin and the leakage of LDH from pancreatic acinar cells （P〈0. 01） following the treatment with a high concentration of carbachol （10^-3 mol/L） in vitro. The addition of 10^-2mol/L PDTC didn＇t result in a significant decrease in the activity of trypsin and the leakage of LDH from pancreatic acinar cells treated with a high concentration of carbachol （10^-3 mol/L） in vitro （P〉0. 05）. It was concluded that intracellular trypsinogen activation is likely involved in pancreatic acinar cellular injury induced by carbachol hyperstimulation in vitro. NF-κB activation may not be involved in pancreatic acinar cellular injury induced by carbachol hyperstimulation in vitro.展开更多
Tetrandrine (1 μM), a bis-benzylisoquinoline alkaloid isolated from Stephania tetrandra S Moore, signifi-cantly decreased tumor necrosis factor alpha (TNFα;10 ng/ml)-induced increase in the number of micro vessels t...Tetrandrine (1 μM), a bis-benzylisoquinoline alkaloid isolated from Stephania tetrandra S Moore, signifi-cantly decreased tumor necrosis factor alpha (TNFα;10 ng/ml)-induced increase in the number of micro vessels that budded from cultured rat choroidal explants. Tetrandrine also decreased the TNFα-induced in-crease in the number of cells composing the microvessels. Ammonium pyrrolidine dithiocarbamate (APDC;0.1-0.3 μM), an inhibitor of nuclear factor-κB (NF-κB), decreased the TNFα-induced increase in the number of microvessels in a concentration-dependent manner. TNFα increased the phosphorylation and degradation of inhibitor of NF-κB (IκBα), as well as increasing the DNA-binding activity of NF-κB in choroidal explants. TNF? induced an increase of vascular endothelial growth factor (VEGF)-A mRNA, but not VEGF-C mRNA or VEGF-D mRNA. TNFα-induced angiogenic action was inhibited by treatment of VEGF-A antibody in cultured choroidal capillaries. Tetrandrine inhibited the TNFα-induced increases of phosphorylation and degradation of IκBα, and reduced the TNFα-induced increase of DNA-binding activity of NF-κB in chor-oidal explants. In conclusion, tetrandrine inhibits TNFα-induced activation of NF-κB in the choroidal capil-laries via inhibition of TNFα-induced phosphorylation of IκBα.展开更多
Psoriasis is a chronic autoimmune disease featured by patches on the skin.It is caused by malfunction of immune cells and keratinocytes with inflammation as one of its key features.Apigenin(API)is a natural flavonoid ...Psoriasis is a chronic autoimmune disease featured by patches on the skin.It is caused by malfunction of immune cells and keratinocytes with inflammation as one of its key features.Apigenin(API)is a natural flavonoid with anti-inflammatory and immunoregulatory properties.Therefore,we speculated that API can ameliorate psoriasis,and determined its effect on the development of psoriasis by using imiquimod(IMQ)-induced psoriasis mouse model.Our results showed that API attenuated IMQ-induced phenotypic changes,such as erythema,scaling and epidermal thickening,and improved splenic hyperplasia.Abnormal differentiation of immune cells was restored in API-treated mice.Mechanistically,we revealed that API is a key regulator of signal transducer activator of transcription 3(STAT3).API regulated immune responses by reducing interleukin-23(IL-23)/STAT3/IL-17A axis.Moreover,it suppressed IMQ-caused cell hyperproliferation by inactivating STAT3 through regulation of extracellular signal-regulated kinase 1/2 and nuclear factor-κB(NF-κB)pathway.Furthermore,API reduced expression of inflammatory cytokines through inactivation of NF-κB.Taken together,our study demonstrates that API can ameliorate psoriasis and may be considered as a strategy for psoriasis treatment.展开更多
Objective To investigate the effect of mucin 1(MUC1)on the proliferation and apoptosis of nasopharyngeal carcinoma(NPC)and its regulatory mechanism.Methods The 60 NPC and paired para-cancer normal tissues were collect...Objective To investigate the effect of mucin 1(MUC1)on the proliferation and apoptosis of nasopharyngeal carcinoma(NPC)and its regulatory mechanism.Methods The 60 NPC and paired para-cancer normal tissues were collected from October 2020 to July 2021 in Quanzhou First Hospital.The expression of MUC1 was measured by real-time quantitative PCR(qPCR)in the patients with PNC.The 5-8F and HNE1 cells were transfected with siRNA control(si-control)or siRNA targeting MUC1(si-MUC1).Cell proliferation was analyzed by cell counting kit-8 and colony formation assay,and apoptosis was analyzed by flow cytometry analysis in the 5-8F and HNE1 cells.The qPCR and ELISA were executed to analyze the levels of TNF-αand IL-6.Western blot was performed to measure the expression of MUC1,NFкB and apoptosis-related proteins(Bax and Bcl-2).Results The expression of MUC1 was up-regulated in the NPC tissues,and NPC patients with the high MUC1 expression were inclined to EBV infection,growth and metastasis of NPC.Loss of MUC1 restrained malignant features,including the proliferation and apoptosis,downregulated the expression of p-IкB、p-P65 and Bcl-2 and upregulated the expression of Bax in the NPC cells.Conclusion Downregulation of MUC1 restrained biological characteristics of malignancy,including cell proliferation and apoptosis,by inactivating NF-κB signaling pathway in NPC.展开更多
Ependymoma is a rare and chemotherapy-resistant brain tumor, which has resulted in a delay in the development of drugs to treat it. A subclass of supratentorial ependymomas (ST-EPN), designated ST-EPN-zinc finger-tran...Ependymoma is a rare and chemotherapy-resistant brain tumor, which has resulted in a delay in the development of drugs to treat it. A subclass of supratentorial ependymomas (ST-EPN), designated ST-EPN-zinc finger-translocation-associated (ZFTA, ST-EPN-ZFTA), exhibits the expression of a fusion protein comprising ZFTA and v-rel reticuloendotheliosis viral oncogene homolog A (RELA), an effector transcription factor of the nuclear factor-kappa B (NF-κB) pathway (ZFTA-RELA). The expression of ZFTA-RELA results in the hyperactivation of the oncogenic NF-κB signaling pathway, which ultimately leads to the development of ST-EPN-ZFTA. To identify inhibitors of the NF-κB signaling pathway activated by the expression of ZFTA-RELA, we used a doxycycline-inducible ZFTA-RELA-expressing NF-κB reporter cell line and found that extracts of the fungus Neosartorya spinosa IFM 47025 exhibited NF-κB inhibitory activity. We identified eight compounds [aszonapyrone A (2), sartorypyrone A (3), epiheveadride (4), acetylaszonalenin (5), (R)-benzodiazepinedione (6), aszonalenin (7), sartorypyrone E (8) and (Z, Z)-N,N’-(1,2-bis[(4-methoxyphenyl)methylene]-1,2-ethanediyl)bis-formamide (9)] from N. spinosa IFM 47025 culture extract using a variety of chromatographic techniques. The structures of these compounds were identified through the analysis of various instrumental data (1D, 2D-NMR, MS, and optical rotation). The NF-κB responsive reporter assay indicated that compounds 2, 3, 5, 7, and 9 exhibited inhibitory activity. We further evaluated the inhibitory activity of these compounds against the expression of endogenous NF-κB responsive genes (CCND1, L1CAM, ICAM1, and TNF) and found that compound 2 showed significant inhibitory activity. Further studies are required to elucidate the mechanism of action of compound 2, which may serve as a lead compound for the development of a novel therapy for ST-EPN-ZFTA.展开更多
Background:Escherichia coli(E.coli)infection in humans and animals usually comes with gut dysbiosis,which is potential culprit to skeletal health,it is still unclear to whether diet interfered gut microbiome changes c...Background:Escherichia coli(E.coli)infection in humans and animals usually comes with gut dysbiosis,which is potential culprit to skeletal health,it is still unclear to whether diet interfered gut microbiome changes can be a protective strategy to bone loss development.Here,the effects of resistant starch from raw potato starch(RPS),a type of prebiotic,on E.coli-induced bone loss and gut microbial composition in meat ducks were evaluated.Results:The results showed that dietary 12%RPS treatment improved bone quality,depressed bone resorption,and attenuated the pro-inflammatory reaction in both ileum and bone marrow.Meanwhile,the 12%RPS diet also increased the abundance of Firmicutes in E.coli-treated birds,along with higher production of short-chain fatty acids(SCFAs)especially propionate and butyrate.Whereas addition ofβ-acid,an inhibitor of bacterial SCFAs production,to the drinking water of ducks fed 12%RPS diet significantly decreased SCFAs level in cecum content and eliminated RPS-induced tibial mass improvement.Further,treatment with MI-2 to abrogate mucosa-associated lymphoid tissue lymphoma translocation protein 1(Malt1)activity replicated the protective role of dietary 12%RPS in E.coli-induced bone loss including reduced the inhibition on nuclear factorκB(NF-κB)inflammasome activation,decreased bone resorption,and improved bone quality,which were correlated with comparable and higher regulatory T cells(Treg)frequency in MI-2 and 12%RPS group,respectively.Conclusions:These findings suggested that the diet with 12%RPS could alleviate E.coli-induced bone loss in meat ducks by changing the gut microbial composition and promoting concomitant SCFAs production,and consequently inhibiting Malt1/NF-κB inflammasome activation and Treg cells expansion.展开更多
Interleukin-1β(IL-1β)-induced signaling is one of the most important pathways in regulating inflammation and immunity.The assembly of the receptor complex,consisting of the ligand IL-1β,the IL-1 receptor(IL-1R)type...Interleukin-1β(IL-1β)-induced signaling is one of the most important pathways in regulating inflammation and immunity.The assembly of the receptor complex,consisting of the ligand IL-1β,the IL-1 receptor(IL-1R)type 1(IL1R1),and the IL-1R accessory protein(IL1RAP),initiates this signaling.However,how the IL1R1-associated complex is regulated remains elusive.Angiopoietin like 3(ANGPTL3),a key inhibitor of plasma triglyceride clearance,is mainly expressed in the liver and exists in both intracellular and extracellular secreted forms.Currently,ANGPTL3 has emerged as a highly promising drug target for hypertriglyceridemia and associated cardiovascular diseases.However,most studies have focused on the secreted form of ANGPTL3,while its intracellular role is still largely unknown.Here,we report that intracellular ANGPTL3 acts as a negative regulator of IL-1β-triggered signaling.Overexpression of ANGPTL3 inhibited IL-1β-induced NF-κB activation and the transcription of inflammatory genes in HepG2,THP1,and HEK293T cells,while knockdown or knockout of ANGPTL3 resulted in opposite effects.Mechanistically,ANGPTL3 interacted with IL1R1 and IL1RAP through its intracellular C-terminal fibrinogen-like domain and disrupted the assembly of the IL1R1-associated complex.Taken together,our study reveals a novel role for ANGPTL3 in inflammation,whereby it inhibits the physiological interaction between IL1R1 and IL1RAP to maintain immune tolerance and homeostasis in the liver.展开更多
基金funded by Korea Institute of Marine Science&Technology Promotion(KIMST)funded by the Ministry of Oceans and Fisheries,Korea(20220488).
文摘Objective:To evaluate the effects of Capsosiphon fulvescens(C.fulvescens)ethanolic extract on inflammation in lipopolysaccharide(LPS)-induced RAW296.7 macrophages.Methods:The protective effects of C.fulvescens ethanolic extract on LPS-induced inflammation in RAW264.7 macrophages were assessed using biochemical analysis,including enzyme-linked immunosorbent assay,quantitative reverse transcription-polymerase chain reaction,and Western blot analysis.To examine reactive oxygen species(ROS)production,flow cytometry analysis,and immunofluorescence staining were used.Furthermore,the modulatory effect of C.fulvescens ethanolic extract on NF-κB activation was investigated.Results:C.fulvescens ethanolic extract significantly attenuated LPS-induced levels of pro-inflammatory cytokines and notably reduced the secretion and mRNA levels of LPS-mediated matrix metalloproteinases.In addition,C.fulvescens ethanolic extract decreased ROS production and suppressed the TLR4/NF-κB signaling pathway.Conclusions:C.fulvescens ethanolic extract alleviates inflammation as well as oxidative stress by modulating the TLR4/NF-κB signaling in LPS-induced RAW264.7 macrophages.C.fulvescens can be used as a potential therapeutic agent to suppress inflammation and oxidative stress-associated diseases.
文摘The relationship between intracelluar trypsinogen activation and NF-κB activation in rat pancreatic acinar cells induced by M3 cholinergic receptor agonist （carbachol） hyperstimulation was studied. Rat pancreatic acinar cells were isolated, cultured and treated with carbachol, the active protease inhibitor （pefabloc） and NF-κB inhibitor （PDTC） in vitro. Intracelluar trypsin activity was measured by using a fluorogenic substrate. The activity of NF-κB was monitored by using electrophoretic mobility shift assay. The results showed that after pretreatment with 2 mmol/L pefabloc, the activities of trypsin and NF-κB in pancreatic acinar cells treated with high concertrations of carbachol （10^-3 mol/L） in vitro was significantly decreased as compared with control group （P〈0.01 ）. The addition of 10^-2 mol/L PDTC resulted in a significant decrease of NF-κB activities in pancreatic acinar cells after treated with high concertrations of carbachol （10^-3 mol/L） in vitro, but the intracelluar trypsinogen activity was not obviously inhibited （P〉0.05）. It was concluded that intracelluar trypsinogen activation is likely involved in the regulation of high concertrations of carbachol-induced NF-κB activation in pancreatic acinar cells in vitro. NF-κB activation is likely not necessary for high concertrations of carbachol-induced trypsinogen activation in pancreatic acinar cells in vitro.
文摘AIM： Different strains of bifidobacteria were analysed for their effects on HT-29 intestinal epithelial cells （IECs） in in vitro models both of the non-inflamed and inflamed intestinal epithelium. METHODS： A reporter gene system in HT-29 cells was used to measure levels of NF-KB activation after challenge with bifidobacteria or after bacterial pre-treatment following LPS challenge. IL-8 protein and pro-inflammatory gene expression was investigated using normal HT-29 cells. RESULTS： None of the bifidobacteria tested induced activation of nuclear factor κB （NF-κB） indicating that bifidobacteria themselves do not induce inflammatory events in IECs. However, six out of eight bifidobacteria tested inhibited lipopolysaccharide- （LPS-） induced NF-κB activation in a dose- and strain-dependent manner. In contrast, NF-κB activation in response to challenge with tumor necrosis factor-α （TNF-α） was affected by none of the tested bifidobacteria, indicating that the inhibitory effect of bifidobacteria is specific for LPS-induced inflammation in IECs. As shown with two of the six inhibitionpositive bifidobacteria, LPS-induced inhibition of NF-κB activation was accompanied by a dose-dependent decrease of interleukin 8 （IL-8） secretion and by lower mRNA levels for IL-8, TNF-α, cyclooxygenase 2 （Cox-2）, and intercellular adhesion molecule 1（ICAM-1）. CONCLUSION： Some strains of bifidobacteria are effective in inhibiting LPS-induced inflammation and thus might be appropriate candidates for probiotic intervention in chronic intestinal inflammation.
文摘Objective: To explore the characteristics of NF-闎 activation in the progress of pancreatitis, the relationship with expression of TNF- in the inflammatory reaction, and prevent the exacerbation of pancreatitis by using NAC. Method: Forty-eight rats were divided into three groups: therapy (group C), pancreatitis (group B) and control (group A). NAC served as the inhibitor of NF-闎 activation. In the time intervals of 1.5, 3.0, 6.0, 12.0 hour, NF-闎 activation was detected with flow cytometry (FCM) and the expression of TNF- mRNA and protein with in situ hybridization (ISH) and enzyme-linked immuno-sorbent assay (ELISA) respectively. Meanwhile, the level of lipase and amylase in the serum was assayed and the pathological change was evaluated. Result: NF-闎 activation in the pancreatitis group was higher than that in the control group (P<0.01), peaked at 3 hours, and was depressed by the inhibitor of NF-闎, NAC. The expression of TNF- as well as the level of lipase and amylase in the serum also rose synchronously with activation of NF-闎. In contrast to group A, it was significantly different (P<0.01) in group B. After using NAC in group C, all of these values were decreased and the in-flammatory reaction in the pancreas abated evidently. The pathology changes of the pancreas were shown to be alleviated in group C. Conclusion: First, NF-闎 activity is intensively initiated in the course of pancreatitis and shown to have closely relationship with the release of cytokines. Second, use of NAC markedly depressed NF-闎 activation. TNF- expression is down regulated by cytokines. It is suggested that NAC probably acts as a useful agent for treatment of pancreatitis by indirectly inhibiting activation of NF-闎.
基金Supported by the National Natural Science Foundation of China, No. 30370643
文摘AIM: To investigate the effect of Tetrandrine (Tet) on LPS-induced NF-κB activation and cell injury in pancreatic acinar cells and to explore the mechanism of Tetrandrine preventing LPS-induced acinar cell injury. METHODS: Male rat pancreatic acinar cells were isolated by collagenase digestion, then exposed to LPS (10 mg/L), Tet (50μmol/L, 100μmol/L) or normal media. At different time point (30 min, 1 h, 4 h, 10 h) after treatment with the agents, cell viability was determined by MTT, the product and nuclear translocation of subunit p65 of NF-κB was visualized by immunofluorescence staining and nuclear protein was extracted to perform EMSA which was used to assay the NF-κB binding activity. RESULTS: LPS induced cell damage directly in a time dependent manner and Tet attenuated LPS-induced cell damage (50μmol/L, P < 0.05; 100μmol/L, P < 0.01). NF-κB p65 immunofluorescence staining in cytoplasm increased and began showing its nuclear translocation within 30 min and the peak was shown at 1 h of LPS 10 mg/L treatment. NF-κB DNA binding activity showed the same alteration pattern as p65 immunofluorescence staining. In Tet group, the immunofluorescence staining in cytoplasm and nuclear translocation of NF-κB were inhibited significantly. CONCLUSION: NF-κB activation is an important early event that may contribute to inflammatory responses and cell injury in pancreatic acinar cells. Tet possesses the protective effect on LPS-induced acinar cell injury by inhibiting NF-κB activation.
文摘Nuclear factor-κB(NF-κB), a transcription factor, which plays a pivotal role in the expression of a wide variety of genes, involves in systemic inflammatory response syndrome and is the new target for therapy. To explore the effects and mechanism of lanthanum on nuclear translocation of NF-κB in macrophage of mice(Mφ), fluorescent antibody technique, western blotting and ELISA(enzyme-linked immunosorbent assay) were employed. Mφ were divided into five groups at random: one was the control group, in which the cells were cultured in medium without any stimulation, one was LPS (lipopolysaccharide) group, in which the cells were incubated with 1 μg·ml -1 LPS for 30 min and one was LaCl_3 group, in which cells were incubated with 2.5 μm of lanthanum chloride for 30 min. The forth group was named as LaCl_3+LPS group, in which cells were incubated with 2.5 μm of lanthanum chloride for 30 min before stimulated with LPS(1 μg·ml -1, 30 min), and the fifth group was known as LaCl_3/LPS group, in which the cells were cultured in medium containing 2.5 μm of lanthanum chloride at first, then the cells were incubated with LPS(1 μg·ml -1, 30 min) after lanthanum chloride was removed from the media. The location of NF-κB p65 subunit (NF-κB/p65) in Mφ was detected by immunofluorescence and fluorescence microscope. The activation of NF-κB/P65 in nuclei was detected by TransAM TM NF-κB/P65 Transcription Factor assay kit. Meanwhile, the expression of NF-κB/p65 in nuclei and that of IκBα in cytoplasm were measured by Western blotting analysis. The majority of FITC-labeled NF-κB/p65 was located in the nuclei stimulated with LPS. However, there was less fluorescence seen in the nuclei of control group, LaCl_3 group, LaCl_3 + LPS group and LaCl_3/LPS group. Compared with LPS group, the IκBα protein level in cytoplasm increase in LaCl_3 group, LaCl_3+LPS group and LaCl_3/LPS group. The expression and activation of nuclei p65 protein decrease significantly in LaCl_3 group, LaCl_3+LPS group and LaCl_3/LPS group, compare with LPS group. All the results indicate that lanthanum inhibits the nuclear translocation of NF-κB induce by LPS, and the effects are partly due to the upregulation of IκB.
基金supported by grants from the National Natural Science Foundation of China(No.30873189)the National 973 Project of China(MOST,2007CB512900)
文摘Staphylococcus aureus （S. aureus） is an important human pathogen which can cause a chronic condition with a high relapse rate despite the aggressive antimicrobial treatment. Recent studies showed that intracellular pattern recognition receptors （including NOD） in response to bacteria or bacterial products play a proinflammatory role by activating nuclear transcription factor-κB （NF-κB）. But how NOD2 mediates the proinflammatory response to S. aureus in mast cells （MCs） is unclear. So, in this study, we attempted to examine the role of NOD2 in inflammatory responses of MCs to S. aureus. P815 cells （a mouse mast cell line） were cultured. Real-time PCR was used to detect the NOD2 mRNA expression in P815 cells during S. aureus infection. The siRNA against NOD2 gene was synthesized and transfected into S. aureus-infected P815 cells. By using the methods of ELISA and flow cytometry, the effects of NOD2 gene silencing on cell phagocytosis, cytokine secretion, NF-κB activation and cell apoptosis of the S. aureus-infected P815 cells were examined. It was found that S. aureus infection could increase the expression of NOD2 mRNA in P815 cells. NOD2 gene interference in P815 cells reduced the number of S. aureus engulfed by P815 cells, the level of cytokines and the activation of NF-κB. In addition, S. aureus could induce the apoptosis of P815 cells, but NOD2 gene silencing did not affect the cell apoptosis rate. Our data suggested that NOD2 plays a key role in pathogen recognition, signal transduction, and NF-κB activation in the inflammatory responses of MCs infected by S. aureus.
基金Supported by a grant from Glaxo-Smithkline, Belgium, a grant from Astra Zeneca, Belgium, and a grant (3-4598) of FRSM,Belgium
文摘AIM： To analyze the effects of NF-kB inhibition by antioxidant pyrrolidine dithiocarbamate （PDTC） or TNF inhibitor pentoxifylline （PTX） on liver regeneration after partial hepatectomy （PH）. METHODS： Saline, PDTC or PTX were injected 1 h before PH and rats were killed at 0.5 and 24 h after PH. Several control groups were used for comparison （injection control groups）. RESULTS： Compared to saline injected controls, NF-kB activation was absent 0.5 h after PH in rats treated with PDTC or PTX. At 24 h after PH, DNA synthesis and PCNA expression were identical in treated and control rats and thus occurred irrespectively of the status of NF-kB activation at 0.5 h. Signal transducer and activator of transcription 3 （Stat3） acUvatJon was observed already 0.5 h after PH in saline, PDTC or PTX group and was similar to Stat3 activation in response to injection without PH. CONCLUSION： These data strongly suggest that （1） NF-kB p65/p50 DNA binding produced in response to PH is not a signal necessary to initiate the liver regeneration, （2） star3 activation is a stress response unrelated to the activation of NF-kB. In conclusion, NF-kB activation is not critically required for the process of liver regeneration after PH.
文摘Summary: To investigate the effect of N-tosyl-L-phenylalanylchloromethyl ketone (TPCK) on tumor necrosis factor-alpha-induced NF-κB activation and apoptosis in U937 cell line, changes and subcellular localization of NF-κB/p65 and IκB-α were observed by fluorescencemicroscopy and expression and degradation of IκB-α by flow cytometry. The apoptosis of U937 cells was measured by flow cytometry and electrophoresis of DNA. Immunolfluorescence assay showed that NF-κB/p65, IκB-α only localized in cytoplasm. After TNF-α stimulation, p65 was localized only in nuclei, and IκB-α was only localized in cytoplasm and decreased. The changes of TNF-α stimulation were specifically inhibited by TPCK. Flow cytometry also revealed the downregulation of IκB-α protein during TNF-α-induced apoptosis and the down-regulation was specifically inhibited by TPCK. Flow cytometry also showed the apoptosis of U937 cells after TNF-α induction. DNA ladder can be detected in cells treated by TNF-α. It is concluded that degradation of IκB-α protein and NF-κB/p65 translocation occur during TNF-α-induced apoptosis of U937 cells, suggesting the activation of NF-κB. TPCK-sensitive protease plays an important role in the degradation of IκB-α protein induced by TNF-α in U937 cells. TPCK sensitive protease also plays an important role in the apoptosis of U937 cells induced by TNF-α.
文摘The relationship between M3 cholinergic receptor agonist （carbachol） hyperstimulationinduced pancreatic acinar cellular injury and trypsinogen activation or NF-κB activation in rats was studied in vitro. Rat pancreatic acinar ceils were isolated, cultured and treated with carbachol, the active protease inhibitor （pefabloc）, and NF-κB inhibitor （PDTC） in vitro. Intracellular trypsin activity was measured by using a fluorogenic substrate. The cellular injury was evaluated by measuring the leakage of LDH from pancreatic acinar ceils. The results showed that as compared with control group, 10-3 mol/L carbachol induced a significant increase of the intracellular trypsin activity and the leakage of LDH from pancreatic acinar cells. Pretreatment with 2 mmol/L pefabloc could significantly decrease the activity of trypsin and the leakage of LDH from pancreatic acinar cells （P〈0. 01） following the treatment with a high concentration of carbachol （10^-3 mol/L） in vitro. The addition of 10^-2mol/L PDTC didn＇t result in a significant decrease in the activity of trypsin and the leakage of LDH from pancreatic acinar cells treated with a high concentration of carbachol （10^-3 mol/L） in vitro （P〉0. 05）. It was concluded that intracellular trypsinogen activation is likely involved in pancreatic acinar cellular injury induced by carbachol hyperstimulation in vitro. NF-κB activation may not be involved in pancreatic acinar cellular injury induced by carbachol hyperstimulation in vitro.
文摘Tetrandrine (1 μM), a bis-benzylisoquinoline alkaloid isolated from Stephania tetrandra S Moore, signifi-cantly decreased tumor necrosis factor alpha (TNFα;10 ng/ml)-induced increase in the number of micro vessels that budded from cultured rat choroidal explants. Tetrandrine also decreased the TNFα-induced in-crease in the number of cells composing the microvessels. Ammonium pyrrolidine dithiocarbamate (APDC;0.1-0.3 μM), an inhibitor of nuclear factor-κB (NF-κB), decreased the TNFα-induced increase in the number of microvessels in a concentration-dependent manner. TNFα increased the phosphorylation and degradation of inhibitor of NF-κB (IκBα), as well as increasing the DNA-binding activity of NF-κB in choroidal explants. TNF? induced an increase of vascular endothelial growth factor (VEGF)-A mRNA, but not VEGF-C mRNA or VEGF-D mRNA. TNFα-induced angiogenic action was inhibited by treatment of VEGF-A antibody in cultured choroidal capillaries. Tetrandrine inhibited the TNFα-induced increases of phosphorylation and degradation of IκBα, and reduced the TNFα-induced increase of DNA-binding activity of NF-κB in chor-oidal explants. In conclusion, tetrandrine inhibits TNFα-induced activation of NF-κB in the choroidal capil-laries via inhibition of TNFα-induced phosphorylation of IκBα.
基金supported by the National Natural Science Foundation of China(NSFC)(81973316,82173807)the China Postdoctoral Science Foundation(2020M681914)+1 种基金the Fund from Tianjin Municipal Health Commission(ZC200093)the Open Fund of Tianjin Central Hospital of Obstetrics and Gynecology/Tianjin Key Laboratory of human development and reproductive regulation(2021XHY01)。
文摘Psoriasis is a chronic autoimmune disease featured by patches on the skin.It is caused by malfunction of immune cells and keratinocytes with inflammation as one of its key features.Apigenin(API)is a natural flavonoid with anti-inflammatory and immunoregulatory properties.Therefore,we speculated that API can ameliorate psoriasis,and determined its effect on the development of psoriasis by using imiquimod(IMQ)-induced psoriasis mouse model.Our results showed that API attenuated IMQ-induced phenotypic changes,such as erythema,scaling and epidermal thickening,and improved splenic hyperplasia.Abnormal differentiation of immune cells was restored in API-treated mice.Mechanistically,we revealed that API is a key regulator of signal transducer activator of transcription 3(STAT3).API regulated immune responses by reducing interleukin-23(IL-23)/STAT3/IL-17A axis.Moreover,it suppressed IMQ-caused cell hyperproliferation by inactivating STAT3 through regulation of extracellular signal-regulated kinase 1/2 and nuclear factor-κB(NF-κB)pathway.Furthermore,API reduced expression of inflammatory cytokines through inactivation of NF-κB.Taken together,our study demonstrates that API can ameliorate psoriasis and may be considered as a strategy for psoriasis treatment.
文摘Objective To investigate the effect of mucin 1(MUC1)on the proliferation and apoptosis of nasopharyngeal carcinoma(NPC)and its regulatory mechanism.Methods The 60 NPC and paired para-cancer normal tissues were collected from October 2020 to July 2021 in Quanzhou First Hospital.The expression of MUC1 was measured by real-time quantitative PCR(qPCR)in the patients with PNC.The 5-8F and HNE1 cells were transfected with siRNA control(si-control)or siRNA targeting MUC1(si-MUC1).Cell proliferation was analyzed by cell counting kit-8 and colony formation assay,and apoptosis was analyzed by flow cytometry analysis in the 5-8F and HNE1 cells.The qPCR and ELISA were executed to analyze the levels of TNF-αand IL-6.Western blot was performed to measure the expression of MUC1,NFкB and apoptosis-related proteins(Bax and Bcl-2).Results The expression of MUC1 was up-regulated in the NPC tissues,and NPC patients with the high MUC1 expression were inclined to EBV infection,growth and metastasis of NPC.Loss of MUC1 restrained malignant features,including the proliferation and apoptosis,downregulated the expression of p-IкB、p-P65 and Bcl-2 and upregulated the expression of Bax in the NPC cells.Conclusion Downregulation of MUC1 restrained biological characteristics of malignancy,including cell proliferation and apoptosis,by inactivating NF-κB signaling pathway in NPC.
文摘Ependymoma is a rare and chemotherapy-resistant brain tumor, which has resulted in a delay in the development of drugs to treat it. A subclass of supratentorial ependymomas (ST-EPN), designated ST-EPN-zinc finger-translocation-associated (ZFTA, ST-EPN-ZFTA), exhibits the expression of a fusion protein comprising ZFTA and v-rel reticuloendotheliosis viral oncogene homolog A (RELA), an effector transcription factor of the nuclear factor-kappa B (NF-κB) pathway (ZFTA-RELA). The expression of ZFTA-RELA results in the hyperactivation of the oncogenic NF-κB signaling pathway, which ultimately leads to the development of ST-EPN-ZFTA. To identify inhibitors of the NF-κB signaling pathway activated by the expression of ZFTA-RELA, we used a doxycycline-inducible ZFTA-RELA-expressing NF-κB reporter cell line and found that extracts of the fungus Neosartorya spinosa IFM 47025 exhibited NF-κB inhibitory activity. We identified eight compounds [aszonapyrone A (2), sartorypyrone A (3), epiheveadride (4), acetylaszonalenin (5), (R)-benzodiazepinedione (6), aszonalenin (7), sartorypyrone E (8) and (Z, Z)-N,N’-(1,2-bis[(4-methoxyphenyl)methylene]-1,2-ethanediyl)bis-formamide (9)] from N. spinosa IFM 47025 culture extract using a variety of chromatographic techniques. The structures of these compounds were identified through the analysis of various instrumental data (1D, 2D-NMR, MS, and optical rotation). The NF-κB responsive reporter assay indicated that compounds 2, 3, 5, 7, and 9 exhibited inhibitory activity. We further evaluated the inhibitory activity of these compounds against the expression of endogenous NF-κB responsive genes (CCND1, L1CAM, ICAM1, and TNF) and found that compound 2 showed significant inhibitory activity. Further studies are required to elucidate the mechanism of action of compound 2, which may serve as a lead compound for the development of a novel therapy for ST-EPN-ZFTA.
基金the National Natural Science Foundation of China(No.31772622)National Natural Science Foundation of China(No.32072748)Doctoral Fellowship from Henan Agricultural University(No.0501182)。
文摘Background:Escherichia coli(E.coli)infection in humans and animals usually comes with gut dysbiosis,which is potential culprit to skeletal health,it is still unclear to whether diet interfered gut microbiome changes can be a protective strategy to bone loss development.Here,the effects of resistant starch from raw potato starch(RPS),a type of prebiotic,on E.coli-induced bone loss and gut microbial composition in meat ducks were evaluated.Results:The results showed that dietary 12%RPS treatment improved bone quality,depressed bone resorption,and attenuated the pro-inflammatory reaction in both ileum and bone marrow.Meanwhile,the 12%RPS diet also increased the abundance of Firmicutes in E.coli-treated birds,along with higher production of short-chain fatty acids(SCFAs)especially propionate and butyrate.Whereas addition ofβ-acid,an inhibitor of bacterial SCFAs production,to the drinking water of ducks fed 12%RPS diet significantly decreased SCFAs level in cecum content and eliminated RPS-induced tibial mass improvement.Further,treatment with MI-2 to abrogate mucosa-associated lymphoid tissue lymphoma translocation protein 1(Malt1)activity replicated the protective role of dietary 12%RPS in E.coli-induced bone loss including reduced the inhibition on nuclear factorκB(NF-κB)inflammasome activation,decreased bone resorption,and improved bone quality,which were correlated with comparable and higher regulatory T cells(Treg)frequency in MI-2 and 12%RPS group,respectively.Conclusions:These findings suggested that the diet with 12%RPS could alleviate E.coli-induced bone loss in meat ducks by changing the gut microbial composition and promoting concomitant SCFAs production,and consequently inhibiting Malt1/NF-κB inflammasome activation and Treg cells expansion.
基金supported by the Natural Science Foundation of China(31871411,31971066,and 82273838)the National Key R&D Program of China(2022YFA0806100)+1 种基金the Natural Science Foundation of Hubei Province(2021CFA004)the Analytical and Testing Center of Huazhong University of Science and Technology.
文摘Interleukin-1β(IL-1β)-induced signaling is one of the most important pathways in regulating inflammation and immunity.The assembly of the receptor complex,consisting of the ligand IL-1β,the IL-1 receptor(IL-1R)type 1(IL1R1),and the IL-1R accessory protein(IL1RAP),initiates this signaling.However,how the IL1R1-associated complex is regulated remains elusive.Angiopoietin like 3(ANGPTL3),a key inhibitor of plasma triglyceride clearance,is mainly expressed in the liver and exists in both intracellular and extracellular secreted forms.Currently,ANGPTL3 has emerged as a highly promising drug target for hypertriglyceridemia and associated cardiovascular diseases.However,most studies have focused on the secreted form of ANGPTL3,while its intracellular role is still largely unknown.Here,we report that intracellular ANGPTL3 acts as a negative regulator of IL-1β-triggered signaling.Overexpression of ANGPTL3 inhibited IL-1β-induced NF-κB activation and the transcription of inflammatory genes in HepG2,THP1,and HEK293T cells,while knockdown or knockout of ANGPTL3 resulted in opposite effects.Mechanistically,ANGPTL3 interacted with IL1R1 and IL1RAP through its intracellular C-terminal fibrinogen-like domain and disrupted the assembly of the IL1R1-associated complex.Taken together,our study reveals a novel role for ANGPTL3 in inflammation,whereby it inhibits the physiological interaction between IL1R1 and IL1RAP to maintain immune tolerance and homeostasis in the liver.
