Silent information regulator sirtuin 1 ameliorates acute liver failure via the p53/glutathione peroxidase 4/gasdermin D axis

BACKGROUND Acute liver failure(ALF)has a high mortality with widespread hepatocyte death involving ferroptosis and pyroptosis.The silent information regulator sirtuin 1(SIRT1)-mediated deacetylation affects multiple biological processes,including cellular senescence,apoptosis,sugar and lipid metabolism,oxidative stress,and inflammation.AIM To investigate the association between ferroptosis and pyroptosis and the upstream regulatory mechanisms.METHODS This study included 30 patients with ALF and 30 healthy individuals who underwent serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST)testing.C57BL/6 mice were also intraperitoneally pretreated with SIRT1,p53,or glutathione peroxidase 4(GPX4)inducers and inhibitors and injected with lipopolysaccharide(LPS)/D-galactosamine(D-GalN)to induce ALF.Gasdermin D(GSDMD)^(-/-)mice were used as an experimental group.Histological changes in liver tissue were monitored by hematoxylin and eosin staining.ALT,AST,glutathione,reactive oxygen species,and iron levels were measured using commercial kits.Ferroptosis-and pyroptosis-related protein and mRNA expression was detected by western blot and quantitative real-time polymerase chain reaction.SIRT1,p53,and GSDMD were assessed by immunofluorescence analysis.RESULTS Serum AST and ALT levels were elevated in patients with ALF.SIRT1,solute carrier family 7a member 11(SLC7A11),and GPX4 protein expression was decreased and acetylated p5,p53,GSDMD,and acyl-CoA synthetase long-chain family member 4(ACSL4)protein levels were elevated in human ALF liver tissue.In the p53 and ferroptosis inhibitor-treated and GSDMD^(-/-)groups,serum interleukin(IL)-1β,tumour necrosis factor alpha,IL-6,IL-2 and C-C motif ligand 2 levels were decreased and hepatic impairment was mitigated.In mice with GSDMD knockout,p53 was reduced,GPX4 was increased,and ferroptotic events(depletion of SLC7A11,elevation of ACSL4,and iron accumulation)were detected.In vitro,knockdown of p53 and overexpression of GPX4 reduced AST and ALT levels,the cytostatic rate,and GSDMD expression,restoring SLC7A11 depletion.Moreover,SIRT1 agonist and overexpression of SIRT1 alleviated acute liver injury and decreased iron deposition compared with results in the model group,accompanied by reduced p53,GSDMD,and ACSL4,and increased SLC7A11 and GPX4.Inactivation of SIRT1 exacerbated ferroptotic and pyroptotic cell death and aggravated liver injury in LPS/D-GalNinduced in vitro and in vivo models.CONCLUSION SIRT1 activation attenuates LPS/D-GalN-induced ferroptosis and pyroptosis by inhibiting the p53/GPX4/GSDMD signaling pathway in ALF.

Evaluation of combined detection of nuclear factor erythroid 2-related factor 2 and glutathione peroxidase 4 in primary hepatic carcinoma and preliminary exploration of pathogenesis

This study aims to analyze the clinical significance and mechanism of nuclear factor erythroid 2-related factor 2(NRF2)and glutathione peroxidase 4(GPX4)in primary hepatic carcinoma(PHC).Methods:The expression of NRF2 and GPX4 in peripheral blood of patients with PHC was determined to analyze the diagnostic value of the two combined for PHC.The prognostic significance of NRF2 and GPX4 was evaluated by 3-year followup.Human liver epithelial cells THLE-2 and human hepatocellular carcinoma cells HepG2 were purchased,and the expression of NRF2 and GPX4 in the cells was determined.NRF2 and GPX4 aberrant expression vectors were constructed and transfected into HepG2,and changes in cell proliferation and invasion capabilities were observed.Results:The expression of NRF2 and GPX4 in patients with PHC was higher than that in patients with LC or VH(p<0.05),and the two indicators combined was excellent in diagnosing PHC.Moreover,patients with high expression of NRF2 and GPX4 had a higher risk of death(p<0.05).In in vitro experiments,both NRF2 and GPX4 expression was elevated in HepG2(p<0.05).HepG2 activity was enhanced by increasing the expression of the two,vice versa(p<0.05).Conclusion:NRF2 and GPX4 combined is excellent in diagnosing PHC,and promotes the malignant development of PHC.

Evaluation of Glutathione Peroxidase Enzymatic Activity in Seminal Plasma of Patients Treated at the Institute Pasteur in Cote d’Ivoire

Glutathione peroxidase (GPx) is an antioxidant that plays an important role in the maintenance of male fertility. The aim of this study was to compare the profile of enzymatic activity of glutathione peroxidase in the seminal plasma of normozoosperm and those of pathological sperm. Thus, the activity of glutathione peroxidase was determined in the seminal plasma of 20 normozoosperms, 9 azoosperms and 31 oligoasthenoteratozoosperms. It was 37.58 ± 3.14 U/L in normozoosperms, 39.39 ± 2.27 U/L in oligoasthenoteratozoosperms, and 29.77 ± 2.62 U/L in azoosperms. The mean GPx enzyme activity of normozoosperms did not differ significantly from that of oligoasthenoteratozoosperms and azoosperms. In contrast, comparison of enzyme activity between abnormal sperms gave a significant difference. This study showed that glutathione peroxidase enzymatic activity is not related to sperm quality.

Glutathione peroxidase mimicry of diphenyl diselenide: Plausible contribution of proteins’ thiols

Organoseleniums are a class of compounds attracting attention across the globe owing to their Glutathione peroxidase(GPx)mimicry,which confers on them a strong antioxidant activity.Diphenyl diselenide(DPDS)is an Organoselenium whose GPx mimetic property has been suggested to rely on the oxidation of non-protein or protein thiols critical to the activities of some sulfhydryl enzymes.This study,therefore investigated the GPx mimic/antioxidant property of DPDS as well as the role of thiols of two key sulfhydryl enzymes,cerebral Na^(+)/K^(+)-ATPase(sodium pump)and hepatic delta-aminolevulinic acid dehydratase(δ-ALAD)in the GPx mimicry of DPDS.Albino Wistar rats were euthanized,and the liver and brain were removed and used to assay for the effect of DPDS on lipid peroxidation induced by two prooxidants[Fe2^(+)(10μM)and H2O2,(1 mM)]as well as the activities of the sulfhydryl enzymes.The results revealed that DPDS profoundly(P<0.05)counteracted Fe2^(+)and H2O2-induced lipid peroxidation in the rats’hepatic and cerebral tissues.Furthermore,the results of assay systems for lipid peroxidation and sodium pump revealed that DPDS inhibited Na^(+)/K^(+)-ATPase and lipid peroxidation in the brain tissue homogenates in the same reaction system.A similar result was obtained in the assay system for lipid peroxidation and hepaticδ-ALAD as DPDS simultaneously inhibited the enzyme’s activity and lipid peroxidation.This suggests that the GPx mimetic property of DPDS may be linked to the enzymes’loss of activity,which further validates the suggestions that the enzymes’inhibition,as well as the antioxidant action of DPDS,rely on the oxidation of critical thiols of the enzymes.However,the GPx mimicry of DPDS should be investigated in the presence of thiol-blocking or oxidizing agents in biological systems in order to further ascertain the role of protein thiols.

抗中性粒细胞胞质抗体相关性肥厚性硬脑膜炎患者临床特点及影像学分析

目的分析抗中性粒细胞胞质抗体(anti-neutrophil cytoplasmic antibody,ANCA)相关性肥厚性硬脑膜炎(hypertrophic pachymeningitis,HP)患者的临床特点。方法回顾性收集2015年8月至2022年6月作者单位收治的10例ANCA相关性HP患者,其中来自中南大学湘雅医院9例,陕西省人民医院1例,男、女各5例,发病年龄43~80岁。分析患者的临床特征、影像学特点、诊治方法及疗效。结果10例患者表现为不同程度的慢性头痛或脑神经受累症状,病程1~84个月。5例患者血清髓过氧化物酶(myeloperoxidase,MPO)和核周型ANCA(perinuclear ANCA,p-ANCA)同时阳性,2例患者仅血清MPO阳性,p-ANCA和细胞质型ANCA(cytoplasmic ANCA,c-ANCA)阳性各1例,p-ANCA和c-ANCA同时阳性1例。6例视力受累,2例听力受累。增强MRI显示患者不同程度的硬脑膜增厚并强化,其中弥漫性增厚4例,局灶性增厚6例,均未累及脑实质。1例患者单用糖皮质激素治疗,1例患者行糖皮质激素联合丙球治疗,8例患者糖皮质激素联合免疫抑制剂治疗,其中1例同时使用利妥昔单抗,经治疗后患者症状均明显缓解。2例在激素和免疫抑制剂减量过程出现头痛加重,再次治疗后症状缓解。结论ANCA相关性HP病程长短不一,临床表现不典型,增强MRI显示的硬脑膜增厚部位在不同ANCA抗体阳性患者间有重叠;糖皮质激素和免疫抑制剂治疗ANCA相关性HP有效。

基于衍生化3-氨基-2-恶唑烷酮的夹心酶联免疫分析

建立一种3-氨基-2-恶唑烷酮(3-amino-2-oxazolidinone,AOZ)夹心免疫检测方法。通过1,6-己二醇连接2-硝基-4-羧基苯甲醛和生物素合成针对AOZ的新型衍生试剂。在样品前处理时加入衍生试剂可对AOZ进行衍生,衍生产率为89%。在酶标板上包被抗AOZ单克隆抗体并以辣根过氧化物酶标记的亲和素或抗生物素抗体作为第二结合物可实现AOZ的夹心酶联免疫吸附检测(enzyme-linked immunosorbnent assay,ELISA)。从实际应用的角度,得到双抗夹心和抗体-亲和素夹心模式下两个表位的极限距离,分别为12Å和13Å,理想距离分别为16Å和17Å。在双抗夹心和抗体-亲和素夹心模式下的检出限分别达到1.8 pg/mL和0.8 pg/mL(以AOZ质量浓度计),相对于竞争ELISA,其灵敏度最高提高了25倍。平均回收率为73%~85%,平均相对标准偏差为9.0%。

铁死亡在不同细菌所致小鼠血流感染模型中的变化规律及生物学意义

背景:发现血流感染新的疾病诊断标志物、治疗疾病及减轻脏器损伤的分子靶点具有重要意义。铁死亡是新发现的一种细胞死亡形式,脓毒症动物模型中铁死亡的过度激活与炎症反应激活以及肝脏、心脏、肾脏等重要脏器的损伤有关,但铁死亡与血流感染的关系尚不十分清楚。目的:探讨铁死亡在不同细菌所致小鼠血流感染模型中的变化规律及生物学意义。方法:建立革兰阴性菌大肠埃希菌、肺炎克雷伯菌及革兰阳性菌金黄色葡萄球菌、粪肠球菌血流感染的SPF级ICR雄性小鼠模型,每组各42只。建模后0.5,1,3,6,12,24,48 h时检测肝脏、心肌、肾脏中铁死亡标志基因转铁蛋白受体1、谷胱甘肽过氧化物酶4 mRNA表达水平。另选用18只SPF级ICR雄性小鼠,随机分为二甲基亚砜(DMSO)对照组、DMSO+肺炎克雷伯菌组、铁死亡抑制剂Ferrostatin-1+肺炎克雷伯菌组,每组6只;后两组采用尾静脉注射肺炎克雷伯菌悬液的方式建立肺炎克雷伯菌血流感染模型,分别在血流感染建模前1 h给予5 mg/kg的Ferrostatin-1及等剂量DMSO腹腔注射;建模后6 h小鼠检测血清中丙氨酸氨基转移酶、天冬氨酸氨基转移酶、血肌酐、血尿素氮、磷酸肌酸激酶同工酶、乳酸脱氢酶以及各组织中铁死亡标志基因的mRNA表达水平。结果与结论:①血流感染建模后,不同细菌血流感染小鼠肝脏、心肌、肾脏中转铁蛋白受体1 mRNA表达水平先升高后降低,谷胱甘肽过氧化物酶4 mRNA表达水平先降低后升高且均在建模后6 h达到峰值;②革兰阴性菌血流感染小鼠中转铁蛋白受体1和谷胱甘肽过氧化物酶4 mRNA表达的变化较革兰阳性菌血流感染小鼠更为显著,其中以肺炎克雷伯菌血流感染小鼠中转铁蛋白受体1和谷胱甘肽过氧化物酶4 mRNA表达的变化最显著;③肺炎克雷伯菌血流感染建模后6 h时,小鼠的丙氨酸氨基转移酶、天冬氨酸氨基转移酶、血肌酐、血尿素氮、磷酸肌酸激酶同工酶、乳酸脱氢酶水平均明显升高;④建模前给予铁死亡抑制剂Ferrostatin-1干预可显著降低丙氨酸氨基转移酶、天冬氨酸氨基转移酶、血肌酐、血尿素氮、磷酸肌酸激酶同工酶、乳酸脱氢酶表达水平;⑤以上结果提示不同细菌致血流感染小鼠中铁死亡明显激活且革兰阴性菌血流感染小鼠的铁死亡激活更为显著;抑制铁死亡可明显减轻肺炎克雷伯菌血流感染小鼠的肝脏、心肌、肾脏损伤。

孕早期孕妇促甲状腺激素、甲状腺过氧化物酶抗体及微小RNA-873-5p水平与妊娠期糖尿病相关性研究

目的:分析研究孕早期促甲状腺激素(TSH)、甲状腺过氧化物酶抗体(TPOAb)及微小RNA-873-5p(miR-873-5p)水平与妊娠期糖尿病(GDM)的相关性。方法:选取定期产检的GDM孕妇命名为GDM组(n=109),另选同期在本院产检的糖耐量正常孕妇为对照组(n=60)。收集两组孕妇的一般资料及孕早期实验室检测指标(TSH、TPOAb、miR-873-5p),采用单因素、多因素分析TSH、TPOAb、miR-873-5p水平与GDM的关系;并绘制ROC曲线分析血清TSH、TPOAb、miR-873-5p水平对GDM的预测价值。结果:GDM组的血清TSH、TPOAb、miR-873-5p水平均高于对照组,差异具有统计学意义(均P<0.05);多因素Logistic回归分析显示,年龄>30岁(OR=1.982)、孕前BMI≥24 kg/m^(2)(OR=2.020)、TSH升高(OR=2.113)、TPOAb升高(OR=2.307)及miR-873-5p水平升高(OR=2.059)是发生GDM的独立危险因素(均P<0.05);ROC曲线分析显示,血清TSH、TPOAb、miR-873-5p及联合检测的曲线下面积(AUC)分别为0.830、0.829、0.762、0.936,联合检测优于单一检测(P<0.05)。结论:TSH、TPOAb及miR-873-5p在GDM孕妇体内呈高表达,可能成为GDM发生的辅助预测指标。

铁死亡诱导剂RAS合成致死分子3抑制病理性瘢痕成纤维细胞的纤维化

背景:病理性瘢痕主要表现为异常的细胞外基质积累和过度的成纤维细胞增殖,成纤维细胞过度增殖就会产生大量以胶原纤维为主的细胞外基质。因此深入探讨成纤维细胞纤维化在病理性瘢痕形成中的作用,将为揭示病理性瘢痕的机制和生物学治疗提供新思路。目的:探讨铁死亡诱导剂RAS合成致死分子3(RAS-selective lethal small molecule 3,RSL3)对人病理性瘢痕成纤维细胞纤维化的影响。方法:收集10例宁夏医科大学总医院烧伤整形美容科提供的病理性瘢痕组织和同一个体正常皮肤组织,提取人病理性瘢痕成纤维细胞和人正常皮肤成纤维细胞用于后续实验;苏木精-伊红染色观察病理性瘢痕组织和正常皮肤组织的形态;倒置显微镜观察病理性瘢痕成纤维细胞和正常皮肤成纤维细胞的外观形态;免疫荧光实验验证所提取的细胞是否为成纤维细胞;用不同浓度的RSL3(1,3,5,7,9,11,13μmol/L)干预细胞,CCK-8法检测RSL3作用于成纤维细胞的半数抑制浓度(IC_(50));设置对照组(不做处理)和RSL3干预组(用7μmol/L的RSL3干预细胞24 h),qRT-PCR和Western blot检测谷胱甘肽过氧化物酶4、Ⅰ型胶原蛋白、Ⅲ型胶原蛋白和α-平滑肌肌动蛋白的mRNA和蛋白的表达;检测细胞丙二醛浓度;划痕试验检测细胞划痕后24 h剩余划痕面积,并计算剩余划痕面积百分比。结果与结论:①与正常皮肤组相比,病理性瘢痕组的谷胱甘肽过氧化物酶4高表达(mRNA:t=3.252,P<0.01;蛋白:t=5.075,P<0.01);②与正常皮肤成纤维细胞组相比,病理性瘢痕成纤维细胞组的谷胱甘肽过氧化物酶4高表达(mRNA:t=10.32,P<0.01;蛋白:t=26.22,P<0.01);③与对照组相比,RSL3干预组谷胱甘肽过氧化物酶4表达减少(mRNA:t=2.798,P<0.05;蛋白:t=4.643,P<0.01),丙二醛浓度上升(t=2.917,P<0.05),Ⅰ型胶原蛋白(mRNA:t=15.84,P<0.01;蛋白:t=4.610,P<0.01)、Ⅲ型胶原蛋白(mRNA:t=28.86,P<0.01;蛋白:t=7.713,P<0.01)和α-平滑肌肌动蛋白(mRNA:t=2.671,P<0.05;蛋白:t=7.417,P<0.01)的表达减少,迁移能力减弱(t=14.06,P<0.01);④提示RSL3通过抑制谷胱甘肽过氧化物酶4的表达,进而抑制病理性瘢痕成纤维细胞的纤维化和迁移能力。

甲状腺功能检测联合TG-Ab、TPO-Ab水平检查对亚临床甲减患者的诊断效果

目的分析甲状腺功能检测联合抗甲状腺球蛋白抗体(TG-Ab)、甲状腺过氧化物酶抗体(TPO-Ab)水平检查对亚临床甲减患者的诊断效果。方法选取2021年10月至2023年10月我院收治的100例疑似亚临床甲减患者为观察组,再选取同期到院进行常规体检的100名健康志愿者为对照组。所有研究对象入院后均进行甲状腺功能与TG-Ab、TPO-Ab水平检测,对比分析两种检查单独与联合应用时的诊断效能。结果两组的游离三碘甲状腺原氨酸(FT3)、游离四碘甲状腺原氨酸(FT4)水平比较,差异无统计学意义(P>0.05);观察组的促甲状腺激素(TSH)、TG-Ab、TPO-Ab水平高于对照组,差异具有统计学意义(P<0.05)。TSH、FT3、FT4和TG-Ab、TPO-Ab联合检测对亚临床甲减的诊断准确度、灵敏度高于单独检测(P<0.05)。结论甲状腺功能联合TG-Ab、TPO-Ab检测诊断亚临床甲减可取得较高的诊断效能。

Imaging of Activity of Horseradish Peroxidase at β-Cyclodextrin Polymer by Scanning Electrochemical Microscopy

The activity of horseradish peroxidase at b-cyclodextrin polymer was imaged by scanning electrochemical microscopy using 3, 3', 5, 5'-tetramethylbenzide and H2O2 as the substrates.

过氧化物酶在食品分子及其胶体体系修饰中的应用进展

过氧化物酶是一类大量存在于自然界及生物体内的氧化还原酶。其家族成员众多,但都可以催化以过氧化氢(H_(2)O_(2))作为底物的氧化反应。现有研究表明可以通过利用过氧化物酶的氧化特性,来提高功能食品的质量属性和营养特性。而辣根过氧化物酶作为过氧化物酶家族的一员,近些年来被大量研究。尤其是在食品研究开发中,有很多研究通过使用辣根过氧化物酶去催化蛋白质或淀粉等食品分子来改善食品本身的性质或获得更合适的食品胶体,因此值得更深层次的挖掘其应用价值及市场。本文在介绍过氧化物酶的结构、催化机制及影响其催化的关键因素基础上,分析了过氧化物酶催化对食品分子结构和性质的影响,综述了近年来过氧化物酶在食品分子及其胶体体系修饰中的一些应用,以期为今后过氧化物酶的研究提供一定的理论参考和新思路。

番茄Ph-2基因晚疫病株龄抗性的比较转录组分析

晚疫病是危害番茄的重要病害,研究表明番茄抗晚疫病Ph-2基因存在株龄相关抗性(age-related resistance,ARR)。通过对Ph-2基因晚疫病抗性材料三叶期与六叶期幼苗接种晚疫病菌后0、8、24、48 h的转录组比较分析,发现接种后0~48 h,Ph-2基因与其他典型抗病基因在三叶期与六叶期幼苗间表达量不存在显著性差异,而2个过氧化物酶活性基因Solyc01g006290与Solyc02g087110在不同苗期叶片中的差异表达可能是导致Ph-2基因晚疫病株龄抗性产生的主要原因,接种后0~48 h,Solyc01g006290基因在六叶期幼苗中表达量始终显著高于三叶期幼苗,该基因正调控木质素合成,并在细胞壁强化中起重要作用;接种后0 h,Solyc02g087110基因在三叶期与六叶期幼苗中表达量不存在显著性差异,而接种后8~48h三叶期幼苗中该基因表达量大幅下调并显著低于六叶期幼苗。此外,三叶期与六叶期幼苗水杨酸与乙烯信号转导途径中响应晚疫病抗性相关基因的表达也存在差异。研究结果为番茄持久抗晚疫病育种提供了一定依据。

Metformin alleviates spinal cord injury by inhibiting nerve cell ferroptosis through upregulation of heme oxygenase-1 expression

Previous studies have reported upregulation of heme oxygenase-1 in different central nervous system injury models.Heme oxygenase-1 plays a critical anti-inflammatory role and is essential for regulating cellular redox homeostasis.Metformin is a classic drug used to treat type 2 diabetes that can inhibit ferroptosis.Previous studies have shown that,when used to treat cardiovascular and digestive system diseases,metformin can also upregulate heme oxygenase-1 expression.Therefore,we hypothesized that heme oxygenase-1 plays a significant role in mediating the beneficial effects of metformin on neuronal ferroptosis after spinal cord injury.To test this,we first performed a bioinformatics analysis based on the GEO database and found that heme oxygenase-1 was upregulated in the lesion of rats with spinal cord injury.Next,we confirmed this finding in a rat model of T9 spinal cord compression injury that exhibited spinal cord nerve cell ferroptosis.Continuous intraperitoneal injection of metformin for 14 days was found to both upregulate heme oxygenase-1 expression and reduce neuronal ferroptosis in rats with spinal cord injury.Subsequently,we used a lentivirus vector to knock down heme oxygenase-1 expression in the spinal cord,and found that this significantly reduced the effect of metformin on ferroptosis after spinal cord injury.Taken together,these findings suggest that metformin inhibits neuronal ferroptosis after spinal cord injury,and that this effect is partially dependent on upregulation of heme oxygenase-1.

Ferroptosis mechanism and Alzheimer's disease

Regulated cell death is a genetically determined form of programmed cell death that commonly occurs during the development of living organisms.This process plays a crucial role in modulating homeostasis and is evolutionarily conserved across a diverse range of living organisms.Ferroptosis is a classic regulatory mode of cell death.Extensive studies of regulatory cell death in Alzheimer’s disease have yielded increasing evidence that fe rroptosis is closely related to the occurrence,development,and prognosis of Alzheimer’s disease.This review summarizes the molecular mechanisms of ferroptosis and recent research advances in the role of ferro ptosis in Alzheimer’s disease.Our findings are expected to serve as a theoretical and experimental foundation for clinical research and targeted therapy for Alzheimer’s disease.

JA-mediated MYC2/LOX/AOS feedback loop regulates osmotic stress response in tea plant

Osmotic stress caused by low-temperature,drought and salinity was a prevalent abiotic stress in plant that severely inhibited plant development and agricultural yield,particularly in tea plant.Jasmonic acid(JA)is an important phytohormone involving in plant stress.However,underlying molecular mechanisms of JA modulated osmotic stress response remains unclear.In this study,high concentration of mannitol induced JA accumulation and increase of peroxidase activity in tea plant.Integrated transcriptome mined a JA signaling master,MYC2 transcription factor is shown as a hub regulator that induced by mannitol,expression of which positively correlated with JA biosynthetic genes(LOX and AOS)and peroxidase genes(PER).CsMYC2 was determined as a nuclei-localized transcription activator,furthermore,ProteinDNA interaction analysis indicated that CsMYC2 was positive regulator that activated the transcription of CsLOX7,CsAOS2,CsPER1 and CsPER3via bound with their promoters,respectively.Suppression of CsMYC2 expression resulted in a reduced JA content and peroxidase activity and osmotic stress tolerance of tea plant.Overexpression of CsMYC2 in Arabidopsis improved JA content,peroxidase activity and plants tolerance against mannitol stress.Together,we proposed a positive feedback loop mediated by CsMYC2,CsLOX7 and CsAOS2 which constituted to increase the tolerance of osmotic stress through fine-tuning the accumulation of JA levels and increase of POD activity in tea plant.

Understanding the molecular crossroads in acute liver failure:A pathway to new therapies

In this editorial we comment on the article published in a recent issue of the World Journal of Gastroenterology.Acute liver failure(ALF)is a critical condition characterized by rapid hepatocellular injury and organ dysfunction,and it often necessitates liver transplant to ensure patient survival.Recent research has eluci-dated the involvement of distinct cell death pathways,namely ferroptosis and pyroptosis,in the pathogenesis of ALF.Ferroptosis is driven by iron-dependent lipid peroxidation,whereas pyroptosis is an inflammatory form of cell death;both pathways contribute to hepatocyte death and exacerbate tissue damage.This comprehensive review explores the interplay between ferroptosis and pyroptosis in ALF,highlighting the role of key regulators such as silent information regulator sirtuin 1.Insights from clinical and preclinical studies provide valuable perspectives on the dysregulation of cell death pathways in ALF and the therapeutic potential of targeting these pathways.Collaboration across multiple disciplines is essential for translating the experimental insights into effective treatments for this life-threatening condition.

多孔HZIF-8固定化酶及其降解苯酚的性能研究

以水凝胶为模板,采用模板乳化法制备锌基MOF材料HZIF-8,利用包埋法和交联法相结合的方法固定辣根过氧化物酶,研究温度、pH以及苯酚浓度对HZIF-8固定化酶降解苯酚的影响。结果表明,HZIF-8固定化酶的最适温度为50℃,最适pH为7,环境耐受力远高于游离酶,半衰期为16 d。放置10 d时,相对酶活性仍达82%,124.64 U/mg。HZIF-8固定化酶最佳降解苯酚条件:50℃,pH=8。重复回收使用6次,相对酶活仍达到50%以上。酸根过氧化物酶(HRP)与HZIF-8固定化酶的K m值分别为9.57 mmol/L和5.69 mmol/L。HZIF-8固定化酶对底物的亲和力高于游离酶,其催化效率相对游离HRP有所提升,固定化酶的操作稳定性和酶活性也显著增强。

雷公藤红素诱导人胰腺癌PANC-1细胞铁死亡的机制研究

目的:探讨雷公藤红素(Cel)诱导的人胰腺癌PANC-1细胞铁死亡的分子机制。方法:体外培养PANC-1细胞,MTT法检测PANC-1细胞活力,分析数据并分组,根据药物对细胞活力抑制的计算结果,选择细胞存活率为50%的Cel剂量,以及高于细胞活力50%的Cel剂量进行后续实验;EdU及克隆形成实验检测Cel对细胞增殖的影响。流式细胞仪及荧光显微镜检测并观察细胞中脂质活性氧(ROS)水平的变化;丙二醛(MDA)试剂盒,谷胱甘肽(GSH)试剂盒以及亚铁离子检测试剂盒分别检测细胞中MDA,GSH以及Fe2+水平;Western blot法检测细胞中谷胱甘肽过氧化物酶4(GPX4)的表达;免疫共沉淀法检测GPX4蛋白的泛素化。结果:与对照组比较,随着Cel药物浓度增大,PANC-1细胞活力,EdU阳性率及克隆形成数量逐渐降低(P<0.05,P<0.01);细胞中单独加入Cel后,细胞变圆,细胞活力降低,而细胞中联合加入铁死亡抑制剂ferrostatin-1(Fer-1)对细胞形态和活力没有显著影响,同时用Cel和Fer-1共处理对细胞形态和活力也没有显著影响;利用BODIPYTM 581/591 C11对细胞中脂质ROS染色后于荧光显微镜下观察荧光变化,并利用流式细胞仪检测细胞中脂质ROS变化,结果显示与对照组相比,PANC-1细胞中加入Cel作用后,细胞中绿色氧化态的脂质ROS荧光明显增加且脂质ROS水平明显增加,而细胞中同时加入Cel和Fer-1后,绿色荧光降低,脂质ROS水平明显降低。与对照组相比,细胞中加入Cel后,MDA及Fe2+水平增加,GSH水平降低;而在细胞中同时加入Cel和Fer-1之后细胞中MDA,Fe2+以及GSH水平恢复到对照组水平几乎一致。结论:Cel通过促进GPX4降解及泛素化诱导胰腺癌细胞铁死亡,抑制胰腺癌细胞的恶性增殖。

Molecular mechanisms of ferroptosis and its role in the treatment of breast cancer

Breast cancer is a critical threat to women around the globe. Current radio- and chemotherapy regimens can induce multiple drug-resistant effects, e.g., anti-apoptosis, anti-pyroptosis, and anti-necroptosis, causing a poor clinical response to therapy. Ferroptosis is a newly programmed cell death characterized by iron overload, the massive production of reactive oxygen species (ROS), and membrane lipid peroxidation. The occurrence of ferroptosis results from an imbalance between peroxidation mechanisms (execution systems) and anti- oxidation mechanisms (defense systems), including the iron metabolism pathway, amino acid metabolism pathway, and lipid metabolism pathway. Recently, the vital role of ferroptosis in various diseases, including cancer, hypertension, diabetes, and Alzheimer's, has been identified. Specifically, triggering ferroptosis in breast cancer cells can inhibit their proliferation and invasion, and improve the chemoradiotherapy sensitivity, which makes it a potential strategy for breast cancer therapy. This review summarizes the definition and features of ferroptosis, as well as its role in the treatment of breast cancer, aimed at providing a theoretical basis for future drug development.