TRAF6调控NLRP3炎症小体信号通路的机制研究

目的:研究肿瘤坏死因子受体相关因子6(TRAF6)对NOD样受体蛋白3(NLRP3)炎症小体信号通路调控作用的机制。方法:利用免疫共沉淀和免疫印迹在HEK-293T细胞中研究TRAF6与NLRP3的相互作用;通过检测乳酸脱氢酶(LDH),在THP-1细胞中研究TRAF6对NLRP3炎症小体信号通路活性的影响。结果:TRAF6通过与NLRP3的相互作用增加NLRP3的稳定性,进而促进NLRP3炎症小体信号通路介导的LDH的释放。结论:TRAF6通过增加NLRP3的稳定性正调控NLRP3炎症小体信号通路。

Acacetin protects against cerebral ischemia-reperfusion injury via the NLRP3 signaling pathway

Acacetin(5,7-dihydroxy-4′-methoxyflavone), a potential neuroprotective agent, has an inhibitory effect on lipopolysaccharide-induced neuroinflammatory reactions. However, whether acacetin has an effect on inflammatory corpuscle 3(NLRP3) after cerebral ischemia-reperfusion injury has not been fully determined. This study used an improved suture method to establish a cerebral ischemia-reperfusion injury model in C57BL/6 mice. After ischemia with middle cerebral artery occlusion for 1 hour, reperfusion with intraperitoneal injection of 25 mg/kg of acacetin(acacetin group) or an equal volume of saline(0.1 mL/10 g, middle cerebral artery occlusion group) was used to investigate the effect of acacetin on cerebral ischemia-reperfusion injury. Infarct volume and neurological function scores were determined by 2,3,5-triphenyltetrazolium chloride staining and the Zea-Longa scoring method. Compared with the middle cerebral artery occlusion group, neurological function scores and cerebral infarction volumes were significantly reduced in the acacetin group. To understand the effect of acacetin on microglia-mediated inflammatory response after cerebral ischemia-reperfusion injury, immunohistochemistry for the microglia marker calcium adapter protein ionized calcium-binding adaptor molecule 1(Iba1) was examined in the hippocampus of ischemic brain tissue. In addition, tumor necrosis factor-α, interleukin-1β, and interleukin-6 expression in ischemic brain tissue of mice was quantified by enzyme-linked immunosorbent assay. Expression of Iba1, tumor necrosis factor-α, interleukin-1β and interleukin-6 was significantly lower in the acacetin group compared with the middle cerebral artery occlusion group. Western blot assay results showed that expression of Toll-like receptor 4, nuclear factor kappa B, NLRP3, procaspase-1, caspase-1, pro-interleukin-1β, and interleukin-1β were significantly lower in the acacetin group compared with the middle cerebral artery occlusion group. Our findings indicate that acacetin has a protective effect on cerebral ischemia-reperfusion injury, and its mechanism of action is associated with inhibition of microglia-mediated inflammation and the NLRP3 signaling pathway.

MiR-146a-5p targeting SMAD4 and TRAF6 inhibits adipogenensis through TGF-β and AKT/mTORC1 signal pathways in porcine intramuscular preadipocytes

Background: Intramuscular fat(IMF) content is a vital parameter for assessing pork quality. Increasing evidence has shown that microRNAs(miRNAs) play an important role in regulating porcine IMF deposition. Here, a novel miRNA implicated in porcine IMF adipogenesis was found, and its effect and regulatory mechanism were further explored with respect to intramuscular preadipocyte proliferation and differentiation.Results: By porcine adipose tissue miRNA sequencing analysis, we found that miR-146a-5p is a potential regulator of porcine IMF adipogenesis. Further studies showed that miR-146a-5p mimics inhibited porcine intramuscular preadipocyte proliferation and differentiation, while the miR-146a-5p inhibitor promoted cell proliferation and adipogenic differentiation. Mechanistically, miR-146a-5p suppressed cell proliferation by directly targeting SMAD family member 4(SMAD4) to attenuate TGF-β signaling. Moreover, miR-146a-5p inhibited the differentiation of intramuscular preadipocytes by targeting TNF receptor-associated factor 6(TRAF6) to weaken the AKT/mTORC1 signaling downstream of the TRAF6 pathway.Conclusions: MiR-146a-5p targets SMAD4 and TRAF6 to inhibit porcine intramuscular adipogenesis by attenuating TGF-β and AKT/mTORC1 signaling, respectively. These findings provide a novel miRNA biomarker for regulating intramuscular adipogenesis to promote pork quality.

miR-146a-5p affects inflammation response of trophoblast by inhibiting TRAF6/NF-кB signaling pathway

Objective:To investigate the association of Micro-rna(miR)-146a-5p expression with preeclampsia,and further explore the potential mechanism involved.Methods:Compared with the blank control group,the expressions of miR-146a-5p and TRAF6 were detected in lipopolysaccharide(LPS)-induced JEG-3 cells.Chorionic carcinoma cell JEG-3 in vitro culture are divided into control,miR-146a-5p mimic+lipopolysaccharide(lps),miR-146a-5p mimic and miR-146a-5p inhibitor groups.qRT-PCR analysis were used to detect the mRNA of miR-146a-5p,IL-1β,IL-6,IL-8 and TNF-α.Western blot assays were carried out to determine the protein expression of TRAF6/NF-кB pathway related proteins.Results:1.miR-146a expression in miR-146a mimic group were significantly higher than the other three groups(P<0.05).2.Compared with the control group,the expression level of miR-146a-5p in JEG-3 cells induced by LPS was significantly increased,and the expression level of TRAF6 was significantly reduced(P<0.05).3.Compared with the control group,the mRNA expression levels of IL-1β,IL-6,IL-8,and TNF-αdecreased significantly after using miR-146a mimic(P<0.05).After adding miR-146a inhibitor,the mRNA expression levels of IL-1β,IL-6,IL-8,and TNF-αwere significantly increased(P<0.05).However,compared with the mimic+LPS group,the difference was not statistically significant(all P>0.05).The results of Western Blot showed that the expression of TRAF6 and NF-κB protein in JEG-3 cells decreased significantly after adding miR-146a mimic and increased after adding miR-146a inhibitor.Conclusion:MiR-146-5p can affect the inflammation response of Maternal-fetal interface by inhibiting TRAF6/NF-кB signaling pathway in preeclampsia.

To explore the mechanism of Dahuang Lingxian Formula in relieving inflammatory response of bile duct cells based on IL-6/JAK/STAT3 signaling pathway

Objective:To explore the mechanism of action of Dahuang Lingxian Formula in alleviating the inflammatory response of bile duct cells in LPS-induced intrahepatic bile duct inflammation model rats based on IL-6/JAK/STAT3 signaling pathway.Methods:Fifty SD rats were randomly divided into five groups,blank group,model group,choling tablets(0.5 g/kg),and low and high concentration groups(2.4 g/kg and 4.8 g/kg)of Dahuang Lingxian Formula,ten rats in each group.Except for the blank group,the rats in each group were injected with 1.25 mg/kg LPS at the common bile duct at one time to construct an animal model of intrahepatic bile duct infection.After gavage on day 8,liver tissues were taken from rats at the hepatic hilum,and the histopathological changes of the hepatic hilum and biliary tree were observed by HE staining.The expression levels of serum glutamic alanine transaminase(ALT),glutamic oxalacetic transaminase(AST),malondialdehyde(MDA)and superoxide dismutase(SOD)were measured by biochemical method.The expression levels of interleukin 6(IL-6),Janus protein tyrosine kinase 2(JAK2),signal transducer and activator of transcription 3(STAT3)in rat serum were measured by enzyme-linked immunosorbent assay(ELISA).Protein immunoblotting(WB)and real-time fluorescence quantitative PCR(RT-qPCR)were used to detect the expression levels of IL-6,JAK2,STAT3 protein and mRNA in biliary tree tissues.Results:①Compared with the blank group,the structures such as interlobular bile ducts in the hepatic sinusoids and portal duct area of the model rats were destroyed,and inflammatory cells infiltrated around them.The expression of ALT,AST,MDA,IL-6,JAK2 and STAT3 in the serum increased significantly,the expression level of SOD decreased,and the expression levels of IL-6,JAK2 and STAT3 proteins and mRNA increased.②Compared with the model group,the degree of liver pathological damage in rats in the Chiling Ning tablet group and the low and high concentration groups of Dahuang Lingxian Formula were improved,which could significantly reduce the expression levels of ALT,AST,MDA,IL-6,JAK2,STAT3 and up-regulate SOD in serum,and down-regulate the expression of IL-6,JAK2,STAT3 protein and mRNA,with the best effect in the high concentration group of Dahuang Lingxian Formula.③Compared with the choling tablet group,the rats in the low and high concentration groups of Dahuang Lingxian Formula tended to normalize the degree of liver pathological damage,without obvious inflammatory cell infiltration,and the expression levels of ALT,AST,MDA,IL-6,JAK2,STAT3 and the expression levels of IL-6,JAK2,STAT3 protein and mRNA in serum were reduced,and the expression levels of SOD were increased,with the best effect of Dahuang Lingxian Formula The treatment effect was best in the high concentration group.Conclusion:The mechanism may be related to the down-regulation of IL-6/JAK/STAT3 signaling pathway activation,and the best therapeutic effect was achieved by the high concentration group of Dahuang Lingxian Formula.

NLRP3炎症小体参与特发性膜性肾病发生的研究

目的:探讨核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)炎症小体在特发性膜性肾病(IMN)中的作用及其激活的可能机制。方法:收集未行肾上腺皮质激素及免疫抑制剂治疗且肾组织活检诊断为IMN的患者135例,10例因肾结核及肾肿瘤行肾切除的患者肾脏组织作为对照组。免疫组化法检测各肾组织样本NLRP3、肿瘤坏死因子受体相关因子6(TRAF6)、Caspase-1、NF-κB p65、MAPK信号通路相关蛋白磷酸化ERK1/2(p-ERK1/2)、磷酸化p38(p-p38)及磷酸化JNK(p-JNK)因子表达;收集IMN患者血液和24 h尿液,分析24 h尿蛋白定量、血肌酐、肌酐清除率、尿素氮等一般临床资料,对尿蛋白与NLRP3、Caspase-1、IL-1β、TNF-α及NLRP3与TRAF6进行相关性分析。结果:与对照组比较,IMN患者24 h尿蛋白和血肌酐明显升高(均P<0.05),肾组织NLRP3和Caspase-1蛋白表达明显升高(均P<0.05),其中Ⅱ期IMN患者肾组织NLRP3和Caspase-1蛋白表达最高,IL-1β和TNF-α表达增强(均P<0.05),其中Ⅱ期IMN患者肾组织IL-1β和TNF-α蛋白表达最强,NF-κB p65、p-ERK1/2、p-p38和p-JNK蛋白表达升高(均P<0.05)。IMN患者24 h尿蛋白与肾组织NLRP3蛋白表达呈正相关(r=0.689,P<0.01),与Caspase-1蛋白呈正相关(r=0.614,P<0.0001),与IL-1β呈正相关(r=0.708,P<0.0001),与TNF-α呈正相关(r=0.594,P<0.01)。结论:TRAF6通过NF-κB激活诱导ERK1/2、p38、JNK信号通路刺激NLRP3炎症小体活化,促进IMN发生和大量尿蛋白产生。

To investigate the effect of Shenqi Tiaoshen Formula on CSE induced inflammatory response of MH-S cells based on TLR4/NF-kB/NLRP3 pathway

Objective:To study the effects of Shenqi Tiaoshen Formula(SQTS)on the inflammatory response of MH-S cells induced by cigarette smoking extract(CSE)and its mechanism based on TLR4/NF-kB/NLRP3 pathway.Methods:MH-S cells were used as subjects to evaluate cell viability by CCK-8 method.The levels of TNF-α,IL-1βand IL-6 in the supernatant were detected by ELISA.ROS were detected by DCFH-DA fluorescence probe.Western blotting was used to detect the expression of TLR4/NF-kB/NLRP3 pathway protein,and TAK-242,a TLR4 inhibitor,was used to verify the role of SQTS in the TLR4/NF-kB/NLRP3 pathway.Results:Compared with blank group,the cell survival rate of CSE group was decreased,and the contents of inflammatory cytokines TNF-α,IL-1βand IL-6 were increased(P<0.05),ROS fluorescence expression level was significantly increased(P<0.01),TLR4/NF-kB/NLRP3 pathway protein expression was significantly increased(P<0.05);Compared with CSE group,the survival rate of cells in SQTS groups was increased,and the expression levels of the above indexes were decreased(P<0.05),and TLR4/NF-kB/NLRP3 pathway protein decreased in TAK-242 groups(P<0.05).Conclusion:SQTS can reduce the inflammatory response of MH-S cells induced by CSE by inhibiting TLR4/NF-kB/NLRP3 pathway.

Mechanism of Sanshi decoction in the treatment of gouty arthritis by NLRP3 inflammasome

Objective:To observe the effect of Sanshi decoction on P2X7R/PKR pathway-mediated activation of macrophage NLRP3 inflammasome to elucidate the molecular mechanism of Sanshi decoction in the treatment of gouty arthritis.Methods:THP-1 macrophages were divided into control group,model group,low dose group,medium dose group,high dose group of Sanshi decoction and inhibitor group.The remaining groups were induced with monosodium urate crystals to establish a gouty arthritis cell model except the control group.Flow cytometry was used to detect macrophage ROS levels in each group,ELISA to detect MDA levels and SOD and GSH-PX activities in each group,and Western blot to detect P2X7R/PKR pathway and NLRP3 inflammasome-associated protein expression.We also used CCK-8 and flow cytometry to measure MH7A activity and apoptotic levels.Results:Compared with the control group,the ROS level,the content of MDA,the activities of SOD and GSH-PX were significantly increased,and the expression levels of NLRP3,full-length IL-1β,pro-IL-1β,full-length IL-18,pro-IL-18,full-length caspase-1,GSDMD-NT,P2X7R and p-PKR protein expression levels were significantly upregulated,and GSDMD-FL protein expression was significantly downregulated in the model group,and that the differences between them were statistically significant(P<0.05 and P<0.01).Compared with the model group,Sanshi decoction could reduce macrophage ROS levels,MDA content,SOD and GSHPX activities,and downregulate macrophage NLRP3,mature IL-1β,pro IL-1β,mature IL-18,pro IL-18,mature caspase-1,GSDMD-NT,P2X7R and p-PKR protein expression,and upregulate GSDMD-FL protein expression,with statistically significant differences(P<0.05 and P<0.01).In addition,MH7A activity was downregulated,and apoptosis level was upregulated in the model group in comparison with the control group,and differences were all significantly different(P<0.05).As compared to the model group,Sanshi decoction could significantly increase the activity of MH7A and inhibit the level of apoptosis,and that the differences between them were statistically significant(P<0.05 and P<0.01).Conclusion:Sanshi decoction can achieve the therapeutic effect of gouty arthritis by inhibiting P2X7R/PKR pathway activation,thus reducing the activation level of NLRP3.

红景天苷通过IL-17A抑制TRAF6/NLRP3信号通路改善Müller细胞的功能

目的探讨红景天苷(salidroside,SAL)对高糖培养的视网膜Müller细胞异常激活的保护作用及其机制。方法采用含10%胎牛血清,1%青-链霉素的DME/F12(1∶1)培养基培养Müller细胞。培养条件为37℃,5%CO_(2)。用25、50、75、100、150 mmol·L^(-1)葡萄糖浓度培养Müller细胞,根据CCK-8实验考察细胞活力确定75 mmol·L^(-1)葡萄糖为最佳浓度。实验分为对照组、HG组、HG+SAL组、HG+IL-17A组、HG+SAL+IL-17A组和HG+IL-17A+siRNA-TRAF6组共6组。通过ELISA检测Müller细胞表达IL-17A水平,通过ROS检测试剂盒检查细胞内ROS水平,MDA检测试剂盒检测细胞内MDA含量,SOD检测试剂盒检测SOD活力。细胞免疫荧光实验检测IL-17A和IL-17RA在细胞内的定位表达情况。Western blotting检测IL-17A、IL-17RA、TRAF6、NLRP3、GFAP、VEGF的蛋白表达水平。结果与对照组相比,HG组Müller细胞表达IL-17A水平明显升高,ROS和MDA含量显著升高,SOD酶活力明显降低,IL-17A、IL-17RA、TRAF6、NLRP3、GFAP、VEGF蛋白表达水平明显升高(P<0.05)。给予SAL后,与HG组相比,Müller细胞表达IL-17A水平显著下降,ROS和MDA含量显著降低,SOD酶活力明显升高,IL-17A、IL-17RA、TRAF6、NLRP3、GFAP、VEGF蛋白表达水平明显下降(P<0.05)。当给予IL-17A活性分子刺激后,相应指标又继续升高(P<0.05),Müller细胞表现异常激活状态。通过细胞免疫荧光实验表明IL-17A和IL-17RA定位表达在细胞质和细胞膜上。结论SAL能改善高糖培养的Müller细胞功能,其可能的机制是通过下调IL-17A表达,进而抑制TRAF6/NLRP3信号通路。

Huoxin Pill Reduces Myocardial Ischemia Reperfusion Injury in Rats via TLR4/NFκB/NLRP3 Signaling Pathway

Objective:To explore the protective effect of Huoxin Pill(HXP)on acute myocardial ischemia-reperfusion(MIRI)injury in rats.Methods:Seventy-five adult SD rats were divided into the sham-operated group,model group,positive drug group(diltiazem hydrochloride,DH),high dose group(24 mg/kg,HXP-H)and low dose group(12 mg/kg,HXP-L)of Huoxin Pill(n=15 for every group)according to the complete randomization method.After 1 week of intragastric administration,the left anterior descending coronary artery of the rat's heart was ligated for 45 min and reperfused for 3 h.Serum was separated and the levels of creatine kinase(CK),creatine kinase isoenzyme(CK-MB)and lactate dehydrogenase(LDH),superoxide dismutase(SOD),and malondialdehyde(MDA),hypersensitive C-reactive protein(hs-CRP)and interleukin-1β(IL-1β)were measured.Myocardial ischemia rate,myocardial infarction rate and myocardial no-reflow rate were determined by staining with Evans blue and 2,3,5-triphenyltetrazolium chloride(TTC).Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP)and Bioinformatics Analysis Tool for Molecular mechANism of Traditional Chinese Medicine(BATMAN)databases were used to screen for possible active compounds of HXP and their potential therapeutic targets;the results of anti-inflammatory genes associated with MIRI were obtained from GeneC ards,Drugbank,Online Mendelian Inheritance in Man(OMIM),and Therapeutic Target Datebase(TTD)databases was performed;Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment were used to analyze the intersected targets;molecular docking was performed using AutoD ock Tools.Western blot was used to detect the protein expression of Toll-like receptor 4(TLR4)/nuclear factor kappa-B(NFκB)/NOD-like receptor protein 3(NLRP3).Results:Compared with the model group,all doses of HXP significantly reduced the levels of LDH,CK and CK-MB(P<0.05,P<0.01);HXP significantly increased serum activity of SOD(P<0.05,P<0.01);all doses of HXP significantly reduced the levels of hs-CRP and IL-1β(P<0.05,P<0.01)and the myocardial infarction rate and myocardial no-reflow rate(P<0.01).GO enrichment analysis mainly involved positive regulation of gene expression,extracellular space and identical protein binding,KEGG pathway enrichment mainly involved PI3K-Akt signaling pathway and lipid and atherosclerosis.Molecular docking results showed that kaempferol and luteolin had a better affinity with TLR4,NFκB and NLRP3 molecules.The protein expressions of TLR4,NFκB and NLRP3 were reduced in the HXP group(P<0.01).Conclusions:HXP has a significant protective effect on myocardial ischemia-reperfusion injury in rats,and its effect may be related to the inhibition of redox response and reduction of the inflammatory response by inhibiting the TLR4/NFκB/NLRP3 signaling pathway.

Hepatic protective effects of Shenling Baizhu powder, a herbal compound, against inflammatory damage via TLR4/NLRP3 signalling pathway in rats with nonalcoholic fatty liver disease

Objective: High-fat diet(HFD) and inflammation are two key contributors to nonalcoholic fatty liver disease(NAFLD). Shenling Baizhu powder(SLBZP), a classical herbal compound, has been successfully used to alleviate NAFLD. However, its specific mechanisms are not fully understood. In this study, we assessed the anti-NAFLD effect of SLBZP in vivo.Methods: Rats were fed an HFD with or without SLBZP or with probiotics. At the end of week 16, an echo magnetic resonance imaging(EchoMRI) body composition analyser was used to quantitatively analyse body composition;a micro-computed tomography(micro-CT) imaging system was used to evaluate whole body and liver fat;and the Moor full-field laser perfusion imager 2 was used to assess liver microcirculation, after which, all rats were sacrificed. Then, biochemical indicators in the blood and the ultrastructure of rat livers were evaluated. Protein expression related to the liver Toll-like receptor 4(TLR4)/Nod-like receptor family pyrin domain-containing 3(NLRP3) signalling pathway was assessed using Western blot analysis. Further, high-throughput screening of 29 related inflammatory factors in liver tissue was performed using a cytokine array.Results: SLBZP supplementation reduced body weight, serum free fatty acid, and insulin resistance index(P<0.05). It also ameliorated liver microcirculation and ultrastructural abnormalities. EchoMRI and micro-CT quantitative analyses showed that treatment with SLBZP reduced fat mass and visceral fat(P<0.05 and P<0.01, respectively). In addition, SLBZP decreased the expression of lipopolysaccharide(LPS)-activated TLR4/NLRP3 signalling pathway-related proteins and altered the expression levels of some inflammatory cytokines in liver tissues.Conclusion: SLBZP can inhibit NLRP3 inflammasome activation and interleukin-1 b release by suppressing LPS-induced TLR4 expression in rats with HFD-induced NAFLD. Thus, SLBZP may be beneficial for the prevention and treatment of inflammatory damage and associated diseases.

Effect of interleukin-6 / signal transducer and activator of transcription 3 pathway on cyclooxygenase- 2 expression in THP- 1 monocyte

Objective To investigate the relationship between the interleukin-6(IL-6)/signal transducer and activator of transcription 3(STAT3)signaling pathway and cyclooxygenase-2(COX-2)expression in THP-1 monocytes.Methods Human THP-1 monocyte was used as the research cell,and the time-dependent expressions of STAT3 phosphorylation and COX-2 were detected

Sphingosine kinase 1 promotes growth of glioblastoma by increasing inflammation mediated by the NF-κB/IL-6/STAT3 and JNK/PTX3 pathways

Glioblastoma(GBM)is the most challenging malignant tumor of the central nervous system because of its high morbidity,mortality,and recurrence rate.Currently,mechanisms of GBM are still unclear and there is no effective drug for GBM in the clinic.Therefore,it is urgent to identify new drug targets and corresponding drugs for GBM.In this study,in silico analyses and experimental data show that sphingosine kinase 1(SPHK1)is up-regulated in GBM patients,and is strongly correlated with poor prognosis and reduced overall survival.Overexpression of SPHK1 promoted the proliferation,invasion,metastasis,and clonogenicity of GBM cells,while silencing SPHK1 had the opposite effect.SPHK1 promoted inflammation through the NF-κB/IL-6/STAT3 signaling pathway and led to the phosphorylation of JNK,activating the JNK-JUN and JNK-ATF3 pathways and promoting inflammation and proliferation of GBM cells by transcriptional activation of PTX3.SPHK1 interacted with PTX3 and formed a positive feedback loop to reciprocally increase expression,promote inflammation and GBM growth.Inhibition of SPHK1 by the inhibitor,PF543,also decreased tumorigenesis in the U87-MG and U251-MG SPHK1 orthotopic mouse models.In summary,we have characterized the role and molecular mechanisms by which SPHK1 promotes GBM,which may provide opportunities for SPHK1-targeted therapy.

The YDA-MKK4/MKK5-MPK3/MPK6 Cascade Functions Downstream of the RGF1-RGI Ligand-Receptor Pair in Regulating Mitotic Activity in Root Apical Meristem

The mitotic activity of root apical meristem(RAM)is critical to primary root growth and development.Previous studies have identified the roles of ROOT GROWTH FACTOR 1(RGF1),a peptide ligand,and its receptors,RGF1 INSENSITIVEs(RGIs),a clade of five leucine-rich-repeat receptor-like kinases,in promoting cell division in the RAM,which determines the primary root length.However,the downstream signaling components remain elusive.In this study,we identify a complete mitogen-activated protein kinase(MAPK or MPK)cascade,composed of YDA,MKK4/MKK5,and MPK3/MPK6,that functions downstream of the RGF1-RGI ligand-receptor pair.Similar to the rgi1/2/3/4/5 quintuple mutant,loss-of-function mutants of MPK3 and MPK6,MKK4 and MKK5,or YDA show a short-root phenotype,which is associated with reduced mitotic activity and lower expression of PLETHORA 1(PLT1)/PLT2 in the RAM.Furthermore,MPK3/MPK6 activation in response to exogenous RGF1 treatment is impaired in the rgi1/2/3/4/5 quintuple,yda single,and mkk4 m kk5 double mutants.Epistatic analyses demonstrated that the expression of constitutively active MKK4,MKK5,or YDA driven by the RGI2 promoter can rescue the short-root phenotype of the rgi1/2/3/4/5 mutant.Taken together,these results suggest that the YDA-MKK4/MKK5-MPK3/MPK6 cascade functions downstream of the RGF1-RGI ligand-receptor pair and upstream of PLT1/PLT2 to modulate the stem cell population and primary root growth in Arabidopsis.

Preliminary identification of key miRNAs, signaling pathways, and genes associated with Hirschsprung's disease by analysis of tissue microRNA expression profiles

Background:Hirschsprung's disease (HSCR) is a congenital gut motility disorder of infants,and if left untreated,it is fatal to the affected infants.This study aimed to identify key microRNAs (miRNAs),signaling pathways and genes involved in the pathogenesis of HSCR.Methods:The miRNA microarray dataset GSE77296 was downloaded.Nine colon tissue samples were available:six from HSCR patients and three matched control samples.Differentially expressed miRNAs (DEMs) were identified after data preprocessing.Target genes of the selected upregulated and downregulated DEMs were predicted.In addition,functional enrichment analyses for the selected DEMs and target genes were conducted.Finally,interaction networks between the DEMs and target genes were constructed.Results:A total of 162 DEMs (73 upregulated and 89 downregulated) were obtained.A total of 2511 DEM-target gene pairs for the 40 selected DEMs were identified,including 1645 pairs for the upregulated DEMs and 866 pairs for the downregulated DEMs.The upregulated DEM miR-141-3p and down-regulated DEM miR-30a-3p were identified as key miRNAs by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment and network analyses.Besides,KEGG pathway enrichment analysis revealed that pathways in cancer and the mitogen-activated protein kinase (MAPK) signaling pathway were key pathways.The key genes frizzled class receptor 3 (FZD3) and docking protein 6 (DOK6) were obtained through the DEM-target gene interaction networks.Conclusion:Two key miRNAs (miR-141-3p and miR-30a-3p),the MAPK signaling pathway and two key genes (FZD3 and DOK6) were implicated in the pathogenesis of HSCR.

Apoptosis in glioma-bearing rats after neural stem cell transplantation

Abnormal activation of the Ras/Raf/Mek/Erk signaling cascade plays an important role in glioma. Inhibition of this aberrant activity could effectively hinder glioma cell proliferation and promote cell apoptosis. To investigate the mechanism of gJioblastoma treatment by neural stem ceiJ trans- plantation with respect to the Ras/Raf/Mek/Erk pathway, C6 glioma cells were prepared in sus- pension and then infused into the rat brain to establish a glioblastoma model. Neural stem cells isolated from fetal rats were then injected into the brain of this glioblastoma model. Results showed that Raf-1, Erk and Bcl-2 protein expression significantly increased, while Caspase-3 protein expression decreased. After transplantation of neural stem cells, Raf-1, Erk and Bcl-2 protein expression significantly decreased, while Caspase-3 protein expression significantly in-creased. Our findings indicate that transplantation of neural stem cells may promote apoptosis of glioma cells by inhibiting Ras/Raf/Mek/Erk signaling, and thus may represent a novel treatment approach for glioblastoma.

Study on the mechanism and active components of Radix et Rhizoma Rhei in the treatment of Alzheimer's disease based on molecular docking

Objective:To explore the mechanism and active components of Radix et Rhizoma Rhei in the treatment of Alzheimer's disease(AD)based on molecular docking.Methods:22 major components of Radix et Rhizoma Rhei were screened from TCMSP and related literatures,which docked with the key targets of NLRP3/Caspase-1/GSDMD signaling pathway.NLRP3,Caspase-1,GSDMD inhibitors MCC950,ML132 and LDC7559 were used as positive control to analyze the docking results.Results:The docking results showed that the main components of Radix et Rhizoma Rhei had different degrees of binding with NLRP3,Caspase-1 and GSDMD targets,and the potential active components were mutanochrome and physciondiglucoside.Conclusion:Molecular docking predicts that the main components of Radix et Rhizoma Rhei may act on NLRP3/Caspase-1/GSDMD signaling pathway,and the active components may be mutanochrome and physciondiglucoside,which provides theoretical basis for revealing the anti-inflammatory mechanism and active components of Radix et Rhizoma Rhei in the treatment of AD.

Whey protein peptide PEW attenuates hyperuricemia and associated renal inflammation in potassium oxonate and hypoxanthine-induced rat

Pro-Glu-Trp(PEW),a whey protein-derived peptide,has been previously shown in vitro to have antihyperuricemic potential.The current study further evaluated the roles and the underlying mechanism of PEW in the management of hyperuricemia(HUA)in rat induced by potassium oxonate(PO)and hypoxanthine.Results revealed that PEW significantly reduced the levels of uric acid(UA),creatinine(Cr),and blood urea nitrogen(BUN)in serum,and effectively suppressed the activities of xanthine oxidase(XOD)associated with UA synthesis and modulated the expression of organic ion transporters related to UA excretion.Moreover,PEW alleviated UAinduced renal inflammation by regulating oxidative stress,suppressing the level of pro-inflammatory cytokines,and inhibiting the activation of NOD-like receptor family pyrin domain-containing 3(NLRP3)inflammasome and Toll-like receptor 4/myeloid differentiation factor 88/NF-kappaB(TLR4/MyD88/NF-κB)signaling pathway.Taken together,these relults indicated that PEW improved HUA and renal inflammation by inhibiting UA synthesis,promoting renal UA excretion and suppressing NLRP3 inflammasome and TLR4/MyD88/NF-κB signaling pathways.