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Aim To explore the therapeutic effect of Erhuang Quzhi Granules on non-alcoholic fatty liver disease ( NAFLD) mouse model induced by Western diet ( WD) combined with low-dose CCl
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Erhuang quzhi compounds is one of the protecting liver and inhibiting toxin prescriptions series summarized by Jinqi Yuan and other famous doctors of traditional Chinese medicine during the long-term clinical practice. It is very effective for non-alcoholic fatty liver disease (NAFLD), but its mechanism is not clear. This research investigated mechanism of Erhuang quzhi granules (EQG) in the treatment of NAFLD. All the animal welfare and experimental procedures are in accordance with the regulations of the Animal Ethics Committee of the First Affiliated Hospital of Shihezi University. Mouse models of NAFLD were established by feeding with methionine and choline deficient diet (MCDD) for five weeks. While feeding MCDD, the treatment groups were given EQG (16.25 g·kg-1·d-1) and atorvastatin (ATO, 7.20 mg·kg-1·d-1) by gavage. The effects of EQG on serum biochemical indices, liver pathological changes, and inflammatory cytokines in mice of NAFLD were investigated. Quantitative real-time PCR (qPCR), immunocytochemistry (ICH) and Western blot assays were used to detect the levels of mRNA and protein associated with nuclear factor kappa B/Nod-like receptor protein 3 (NF-κB/NLRP3) in liver. The results showed that EQG significantly reduced the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), and improved the level of low-density lipoprotein cholesterol (LDL-C). The result of hematoxylin-eosin (HE) staining showed that EQG reduced lipid deposition in livers of mice. Meanwhile, EQG notably decreased the levels of interleukin (IL)-1β, IL-6, IL-18 and tumor necrosis factor-α (TNF-α), and mRNA levels of NF-κB, NLRP3, IL-1β, TNF-α, down-regulated the expression of F4/80, IκB kinase β (IKKβ), NLRP3 and apoptosis-associated speck-like protein containing a CARD (ASC) and inhibited the activation of NF-κB and cysteinyl aspartate specific proteinase-1 (caspase-1). These findings announced that EQG could improve NAFLD via NF-κB/NLRP3 pathway possibly, which provides a theoretical basis for the further development and utilization of EQG in clinic.
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Objective:To investigate the level of endogenous hydrogen sulfide (H 2S) in contrast-induced acute kidney injury (CIAKI), as well as the potential role of H 2S against CIAKI by down-regulating NLRP3 inflammasome. Methods:Twenty-four healthy male Sprague-Dawley rats, weighing 180-220 g, were randomly divided into three groups according to the random number table method: control group, CIAKI group (iopromide 2.9 g/kg) and CIAKI+NaHS group (NaHS 4 mg/kg for three days before 2.9 g/kg iopromide injection). Kidneys were collected for whole-genome sequencing and bioinformatic analysis. HE and PAS staining were used for kidney histological examination. TUNEL assays were applied to detect renal tubular epithelial injury. Expressions of NLRP3 inflammasome (NLRP3, ASC and caspase-1) were evaluated by immunofluorescence staining. The role of H 2S in contrast (iopromide 200 mgI/kg)-induced injury on human renal tubular epithelium (HK-2 cells) was investigated, and CCK-8 assay was used to detect cellular viability. Results:Compared with the control group, the expression of endogenous H 2S synthetases-related genes [cystathionine β-synthase ( CBS), cystathionine-γ-lyase ( CSE) and 3-mercaptopyruvate sulfurtransferase ( 3- MST)] was lower in CIAKI group (all P<0.05). The gene expression levels of CBS, CSE and 3- MST were negatively correlated with renal function biomarkers serum creatinine, blood urea nitrogen and cystatin-C (all P<0.05). Compared with the CIAKI group, CIAKI+NaHS group showed alleviated creatinine, blood urea nitrogen and cystatin-C, improved histological changes, reduced apoptosis. Moreover, the expression levels of NLRP3, ASC and caspase-1 in CIAKI+NaHS group were lower than those in CIAKI group (all P<0.05). In HK-2 cells, compared with the contrast group, the cellular viability was higher in the contrast+NaHS group; reducing endogenous H 2S by CBS inhibitor could enhance contrast-induced cell viability ( P<0.05). Conclusions:Injury of endogenous H 2S system is pivotal to CIAKI pathogenesis. Up-regulation of H 2S ameliorates renal injury of CIAKI rats, which may be related to regulation of NLRP3 inflammasome.
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Objective:To investigate the expression of NOD-like receptor protein 3 (NLRP3) inflammasome in intestinal injury models with different severity of sepsis and the inflammatory response and apoptosis mediated by NLRP3 inflammasome.Methods:Human colorectal adenocarcinoma cells (Caco-2) were cultured in vitro. The logarithmic growth phase cells were divided into blank control group (normal culture in complete medium) and lipopolysaccharide (LPS) 1, 2 and 4 mg/L groups (complete medium containing 1, 2 and 4 mg/L LPS, respectively). The supernatant were collected at 6, 12 and 24 hours, and the levels of tumor necrosis factor-α (TNF-α), interleukins (IL-6, IL-1β, IL-18) were detected by enzyme linked immunosorbent assay (ELISA). The apoptotic level of cells was detected by flow cytometry. The cells were harvested, and the real-time fluorescence quantitative reverse transcription-polymerase chain reaction (RT-qPCR) was used to detect the mRNA expressions of NLRP3 and silent information regulator 1 (SIRT1). Western blotting was used to detect the protein expressions of NLRP3, SIRT1, caspase-1 and apoptosis-associated speck-like protein (ASC). Results:ELISA results showed that the levels of IL-6, TNF-α, IL-1β, and IL-18 in cell supernatant of LPS groups increased in a dose-dependent and time-dependent manner as compared with the blank control group during the same intervention period. The increase was most significant in LPS 4 mg/L group at 24 hours [IL-6 (ng/L): 3.55±0.06 vs. 0.67±0.09, TNF-α (ng/L): 15.37±0.19 vs. 5.04±0.14, IL-1β (ng/L): 2.26±0.10 vs. 0.56±0.09, IL-18 (ng/L): 433.92±22.55 vs. 93.55±21.13, all P < 0.05]. The results of the apoptotic test showed that, compared with the blank control group, the apoptotic rate of LPS groups increased in a dose-dependent and time-dependent manner, and the apoptotic rate of LPS 4 mg/L group increased most significantly at 24 hours [(14.83±3.73)% vs. (5.87±1.17)%, P < 0.05]. RT-qPCR results showed that the expression level of NLRP3 mRNA was increased, while the expression level of SIRT1 mRNA was decreased with the increase of LPS intervention dose and the prolonging of intervention time. At 24 hours, there were significant differences between LPS 4 mg/L group and blank control group [NLRP3 mRNA (2 -ΔΔCt): 8.20±2.82 vs. 1.00±0.36, SIRT1 mRNA (2 -ΔΔCt): 0.58±0.01 vs. 1.03±0.06, both P < 0.05]. Western blotting showed that compared with the blank control group, the protein expression levels of NLRP3, caspase-1 and ASC in LPS groups were significantly increased, while the protein expression levels of SIRT1 were significantly decreased. During each intervention period, with the increase of LPS dose, the expressions of NLRP3, caspase-1 and ASC protein increased gradually, while the expression of SIRT1 protein decreased gradually. At 24 hours, the difference between the LPS 4 mg/L group and the blank control group was significant [NLRP3 protein (NLRP3/β-actin): 1.48±0.03 vs. 0.90±0.12, caspase-1 protein (caspase-1/β-actin): 1.18±0.11 vs. 0.72±0.09, ASC protein (ASC/β-actin) : 1.09±0.01 vs. 0.82±0.03, SIRT1 protein (SIRT1/β-actin): 0.48±0.03 vs. 0.76±0.05, all P < 0.05]. Conclusion:In vitro, in the sepsis induced intestinal inflammation model, with the increase of LPS intervention dose and the prolongation of intervention time, intestinal inflammatory response and cell apoptosis showed an increasing trend, which may be related to the up-regulation of NLRP3 inflammasome and its downstream products ASC and caspase-1, and to the down-regulation of SIRT1 expression.
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Objective:To explore whether resveratrol (RSV) could activate silent information regulator 1 (SIRT1) to regulate the activation of NOD-like receptor protein 3 (NLRP3) inflammasome in sepsis induced intestinal injury model, and then reduce intestinal inflammation and cell apoptosis, so as to play a protective role in intestinal barrier function.Methods:① In vitro experiment: human Colorectal adenocarcinoma cells (Caco-2) were cultured, which were divided into normal group (normal culture on complete medium for 48 hours), lipopolysaccharide (LPS) group (normal culture on complete medium for 24 hours, then LPS containing 2 mg/L complete medium intervention for 6 hours), RSV low, medium and high concentration groups and SIRT1 inhibitor (EX-527) group (complete medium normal culture for 24 hours, LPS containing 2 mg/L complete medium intervention for 6 hours, followed by RSV 10, 20, 40 μmol/L or EX-527 10 μmol/L intervention for 6 hours, respectively). The levels of tumor necrosis factor-α (TNF-α) and interleukins (IL-6, IL-18, IL-1β) in the cell supernatant were determined by enzyme linked immunosorbent assay (ELISA). The apoptosis level of the cells was detected by flow cytometry. Western blotting was used to detect the protein levels of NLRP3, SIRT1, caspase-1 and apoptosis-associated speck-like protein containing a CARD (ASC). ② In vivo experiment: according to random number table method, 24 male Wistar rats were divided into sham operation group (Sham group), cecal ligation and perforation (CLP) 6 hours group (CLP 6 h group), CLP 24 h group and RSV intervention group [RSV (20 mg/kg) was intraperitoneally injected 6 hours and 12 hours after CLP], with 6 rats in each group. The levels of NLRP3, caspase-1 and ASC in the intestine of rats were detected by immunohistochemistry. Results:① Compared with the normal group, the levels of inflammatory factors in the cell supernatant of the LPS group were increased and the expression of SIRT1 protein was decreased, while the protein expressions of NLRP3, caspase-1 and ASC were increased. Compared with LPS group, different concentrations of RSV reduced the level of inflammatory factors, increased the activity of SIRT1, inhibited the expression of NLRP3 inflammasome and its downstream products caspase-1 and ASC, and the effect of high concentration of RSV (40 μmol/L) was the most significant [TNF-α (ng/L): 8.77±0.43 vs. 12.66±0.81, IL-6 (ng/L): 1.35±0.20 vs. 1.93±0.09, IL-1β (ng/L): 1.05±0.04 vs. 1.31±0.07, IL-18 (ng/L): 519.50±11.16 vs. 622.70±30.69, SIRT1/β-actin: 0.80±0.05 vs. 0.58±0.02, caspase-1/β-actin: 0.55±0.06 vs. 0.78±0.06, ASC/β-actin: 0.78±0.08 vs. 1.04±0.15, all P < 0.05], while SIRT1 inhibitor EX-527 had the opposite effects. There was no significant difference in the apoptosis rate among normal group, LPS group, and low, medium and high concentration RSV groups, as well as EX-527 group [(7.03±0.57)%, (9.67±0.55)%, (9.57±0.70)%, (9.30±2.15)%, (9.87±0.97)%, (9.07±0.93)%, F = 2.590, P = 0.082]. ② Immunohistochemical results showed that compared with the Sham group, the expressions of NLRP3 inflammasomes and downstream products caspase-1 and ASC in the intestinal epithelial cells in CLP 6 h group, CLP 24 h group and RSV intervention group were significantly increased. The percentage of ASC-positive area in intestinal epithelium of RSV intervention group was significantly lower than that of CLP 6 h group [(15.22±2.73)% vs. (19.88±2.67)%, P < 0.05], and the expressions of NLRP3 and caspase-1 were significantly lower than those of CLP 24 h group [(9.31±1.37)% vs. (13.19±1.92)%, (19.57±3.92)% vs. (27.28±6.33)%, both P < 0.05]. Conclusion:After sepsis, high concentration of RSV could inhibit the activation of NLRP3 inflammasome by activating SIRT1, thereby reduce the expression of caspase-1 and ASC, and inhibit the secretion of inflammatory factors to reduce the inflammatory response.
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This study was to investigate the protective effects of puerarin on myocardial ischemia/reperfusion (MI/R) injury and the underlying mechanism. The MI/R-model was established by ligating the left anterior descending artery (LAD) for 60 min followed by 24 h reperfusion, puerarin (10, 30, and 100 mg·kg-1) was orally administered 20 min before reperfusion. Cardiac function, myocardial infarct index, cardiac damage markers, inflammatory cytokines, and apoptosis index were measured to evaluate the protective effects of puerarin on MI/R injury. The activation of Nod-like receptor protein 3 (NLRP3) inflammasome and Toll like receptor 4 (TLR4)/myeloid differentiation factor 88 (Myd88)/nuclear factor kappa B (NF-κB) pathway were determined by Western blot. All animal experimental procedures were approved by the ethics committee of the Institute of Materia Medica, Peking Union Medical College, Chinese Academy of Medical Sciences. The results showed that puerarin could significantly improve cardiac function, reduce myocardial infarct size, decease the levels of lactic dehydrogenase (LDH), aspartate transaminase (AST), creatine kinase-MB (CK-MB), and cardiac troponin T (cTnT) and suppress cardiomyocyte apoptosis. Meanwhile, puerarin could notably decrease the levels of inflammatory cytokines such as interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α). Western blot analysis revealed that puerarin could downregulate the expression of TLR4, Myd88, NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), cleaved-caspase 1, cleaved-gasdermin-D (GSDMD), IL-1β, and IL-18, as well as the phosphorylation levels of inhibitor of NF-κB α (IκBα), IκB kinase β (IKKβ), and NF-κB. These findings demonstrated that puerarin could alleviate MI/R injury by suppressing NLRP3 inflammasome activation, possibly via TLR4/Myd88/NF-κB pathway.
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In this study, the model of Propionibacterium acnes/lipopolysaccharide (P. acnes/LPS)-induced acute liver injury in mice was employed to investigate the protective effects of Fuzheng Yanggan Fomula (FYF) on acute liver injury. The effects of FYF on the contents of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and interleukin-1β (IL-1β) in the serum, and the levels of malondialdehyde (MDA), oxygen radical absorbance capacity (ORAC), and glutathione (GSH) were examined in the livers of mice treated with P. acnes/LPS; The protein expression levels of Nod-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein containing a CARD (ASC), cysteinyl aspartate specific proteinase-1 (caspase-1), and IL-1β in liver tissues were detected by Western blot; Furthermore, hematoxylinendash-eosin (HE) staining, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, and immunohistochemical assay were used to observe pathological changes, apoptosis index, and inflammation infiltration of the liver tissue sections. All animal welfare and experimental procedures were followed by the Animal Ethics Committee of Jinan University. We conclude that FYF could alleviate P. acnes/LPS induced pathological damage and inflammatory infiltration in the liver of mice. Meanwhile, FYF decreases the contents of ALT, AST, IL-1β, and MDA, increases the contents of ORAC and GSH, and downregulates the expression of caspase-1 and IL-1β proteins. Collectively, these findings suggested that FYF could alleviate P. acnes/LPS induced acute liver injury in mice by inhibiting the activation of NLRP3 inflammasome, which provides a theoretical basis and a new drug target for the prevention and treatment of liver injury.
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Nonalcoholic steatohepatitis (NASH) is an important pathological stage of nonalcoholic fatty liver disease characterized by hepatocyte fatty degeneration, liver injury, and liver inflammation and can further develop into liver cirrhosis and hepatocellular carcinoma. The NOD-like receptor family, pyrin domain-containing protein 3 (NLRP3) inflammasome is a multi-protein complex in cells and can induce cell apoptosis and expand inflammatory response by activating caspase-1 and releasing mature inflammatory factors such as interleukin-1β and interleukin-18. Recent studies have found that NLRP3 inflammasome may participate in the development and progression of NASH. Therefore, this article summarizes the role of NLRP3 inflammasome in NASH, so as to provide a theoretical basis for future research and treatment.
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PURPOSE: This study demonstrates that estradiol downregulates inflammation and inhibits colorectal cancer (CRC) development in azoxymethane/dextran sulfate sodium (AOM/DSS) mouse model. MATERIALS AND METHODS: AOM/DSS-treated male and female mice were sacrificed at weeks 2, 10, and 16, to assess estrogen effects on colitis and carcinogenesis. Macroscopic and histologic severity of colitis and Western blot and quantitative real-time polymerase chain reaction were evaluated, to measure inflammatory mediators and cytokines. RESULTS: Compared with AOM/DSS-treated male mice (M-AOM/DSS group), AOM/DSS-treated male mice with estradiol administration (M-AOM/DSS+estr group) displayed at week 2 significantly decreased severity of colitis. At weeks 10 and 16, AOM/DSS-treated female mice (F-AOM/DSS group) and the M-AOM/DSS+estr group showed significantly lower tumor multiplicity compared with the M-AOM/DSS group. At week 2, F-AOM/DSS group had a lower level of nuclear factor-κB (NF-κB) expression and higher level of nuclear factor erythroid 2-related factor 2 (Nrf2) expression, compared to the M-AOM/DSS group. At week 2, expression levels of NF-κB and its related mediators decreased in the M-AOM/DSS+estr group, while levels of Nrf2 and Nrf2-related anti-oxidant enzymes increased. In addition, estradiol significantly increased Nod-like receptor protein 3 (NLRP3) inflammasome expressions in AOM/DSS-treated male mice. In contrast, at weeks 10 and 16, Nrf2 and its-related anti-oxidant enzymes and NLRP3 inflammasome were highly expressed in M-AOM/DSS group and in F-AOM/DSS group, who developed cancer. CONCLUSION: The data suggest that estradiol inhibits the initiation of CRC by regulating Nrf2-related pathways. Moreover, these imply the dual role of Nrf2 and NLRP3 inflammasome, including promotion of tumor progression upon tumor initiation.
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Animals , Female , Humans , Male , Mice , Blotting, Western , Carcinogenesis , Colitis , Colorectal Neoplasms , Cytokines , Estradiol , Estrogens , Inflammasomes , Inflammation , NF-E2-Related Factor 2 , NF-kappa B , Real-Time Polymerase Chain Reaction , Sex Characteristics , SodiumABSTRACT
Objective To investigate the effect of pyrin domain 3 (NLRP3) inflammasome in the process of contrast induced human kidney cell apoptosis.Methods Human kidney 2 (HK-2) cells were cultured in DMEM-F12 medium with 5％ FBS.Cells were divided into control group,Contrast group (O group),NLRP3-siRNA+Iohexol group (si-NLRP3+O group),ASC-siRNA+Iohexol group (si-ASC+O group),and mannitol group (M group).Different concentrations of hypotonic contrast agent were added to HK-2 cell culture plates for 24,48 and 72 h.Flow cytometry was used to detect apoptosis.NLRP3 and ASC mRNA expressions were detected by RT-PCR.The expressions of NLRP3,ASC,caspase-8/cleaved caspase-8,Bcl-2/Bax,caspase-1/cleaved caspase-1,and caspase-3/cleaved caspase-3 protein were detected by Western blot.The levels of interleukin (IL) 1β and IL-18 in supernatant were detected by ELISA.Results Compared with the control group,the rate of apoptotic cells,as well as the expressions of NLRP3,ASC and cleaved caspase-1 proteins were increased in HK-2 cells of contrast group.The expressions of NLRP3 and ASC mRNA in the contrast group also increased,so did IL-1β and IL-18 levels (all P＜0.05),suggesting that NLRP3 inflammasome in HK-2 cells was activated by contrast.Compared with the control group,the expressions of cleaved caspase-8,Bax and cleaved caspase-3 protein were increased,and the expression of anti-apoptotic protein Bcl-2 was decreased (all P ＜ 0.05).Compared with the contrast group,the rate of apoptotic cells in the si-NLRP3 + contrast group and si-ASC + contrast group was significantly decreased;the expression of cleaved caspase-1 was decreased;the expressions of Bax and cleaved caspase-3 were decreased,and Bcl-2 level was increased.The expressions of IL-1β and IL-18 in the supernatant of cells were decreased (all P ＜ 0.05).Conclusion Contrast agent can activate the NLRP3 pathway in HK-2 cells and induce apoptosis,which could be reduced by blocking the NLRP3 pathway.
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AIM: To investigate whether Toll-like receptor 4 ( TLR4 ) and Nod-like receptor protein 3 (NLRP3) inflammasome were involved in contrast medium (CM)-induced inflammation and injury in renal tubular epithe-lial cells.METHODS: Iopromide was used to injure NRK-52E cells in the study.The cell viability was measured by CCK-8 assay.The protein levels of TLR4, NLRP3, apoptosis-associated speckle-like protein (ASC), caspase-1 and cleaved caspase-3 were determined by Western blot .The releases of interleukin ( IL )-1βand IL-18 were detected by ELISA .The apoptotic rate was evaluated by Hoechst staining , and mitochondrial membrane potential ( MMP) was analyzed by JC-1 staining.siRNA was transfected into the NRK-52E cells to silence NLRP3 expression.RESULTS:CM decreased the viability of NRK-52E cells (P<0.05).CM also elevated the protein levels of cleaved caspase-3, TLR4, NLRP3, IL-1βand IL-18 (P<0.05).Silencing NLRP3 attenuated CM-induced releases of inflammatory cytokines .Moreover, treat-ment with TLR4 inhibitor TAK-242 or knockdown of NLRP3 by siRNA transfection both attenuated cell apoptosis and loss of MMP caused by CM .CONCLUSION:TLR4/NLRP3 inflammasome takes part in the pathogenesis of CM-induced acute kidney injury , and mediates CM-induced injury and inflammation in renal tubular epithelial cells .