顺铂诱导铁死亡促进肿瘤相关巨噬细胞极化抑制宫颈癌细胞耐药性北大核心

目的:探究顺铂通过引起宫颈癌细胞铁死亡进而诱导肿瘤相关巨噬细胞极化从而抑制宫颈癌细胞耐药性的机制。方法:使用5μmol/L顺铂处理顺铂耐药宫颈癌细胞Hela/R一定时间后,采用qRT-PCR法检测铁死亡相关基因的mRNA表达变化情况;使用ELISA试剂盒和荧光染色法测定铁死亡后的Hela/R细胞释放高迁移率族蛋白1(high mobility group box 1,HMGB1)的情况。将顺铂处理过的Hela/R细胞和M2型小鼠骨髓来源巨噬细胞共培养一定时间后,采用流式细胞术检测巨噬细胞激活情况。将共培养后的巨噬细胞和Hela/R细胞共孵育,采用CCK8法和流式细胞术分别检测肿瘤细胞的存活率和凋亡情况。结果:实验数据显示,顺铂可引起Hela/R细胞的铁死亡,抑制其铁死亡抑制基因Slc40a1、Slc7a11、Slc3a2、Gpx4、Fth1、Blvrb的mRNA表达(P<0.05),上调铁死亡诱发基因Slc5a1、Tfrc的mRNA表达(P<0.01)。铁死亡Hela/R细胞释放损伤相关模式分子HMGB1,诱导M2型肿瘤相关巨噬细胞的CD80、CD86和CD40平均荧光强度提升,增强了肿瘤相关巨噬细胞对Hela/R细胞的杀伤能力。结论:顺铂通过引起宫颈癌细胞的铁死亡激活肿瘤相关巨噬细胞进而达到有效杀伤肿瘤细胞的效果。     

双氢青蒿素诱导肿瘤细胞铁死亡及其机制研究

目的阐明双氢青蒿素(DHA)诱导肿瘤细胞铁死亡的作用及其机制。方法利用3,3′,5,5′-四甲基联苯胺(TMB)检测DHA与FeSO_4体外芬顿样(Fenton)反应生成氧自由基(·OH)的能力;MTT法检测DHA对人肝癌HepG2细胞的毒性(包括FeSO_4与去铁胺预处理组)。MTT法考察谷胱甘肽(GSH)与铁死亡抑制剂(Fer-1)对DHA细胞毒性的影响;采用DCFH-DA染料考察DHA(包括FeSO_4预处理组)诱导的细胞内活性氧的生成能力;采用C11-BODIPY581/591与DiO分别考察DHA(包括FeSO_4预处理组)对细胞内脂质过氧化物生成能力以及细胞膜结构的影响;利用谷胱甘肽过氧化物酶4(GPX-4)试剂盒测定DHA(包括FeSO_4预处理组)对HepG2细胞内GPX-4活性的影响。结果 Fe~(2+)能够催化DHA发生芬顿样反应并生成·OH;DHA的半数抑制浓度(IC_(50))为(39.96±8.78)μmol/L,FeSO_4与去铁胺分别能够增加或者降低DHA的细胞毒性;DHA处理后细胞内活性氧含量与脂质过氧化物含量升高,细胞形态变大,细胞膜呈散点状分布并呈现解离状态。FeSO_4预处理组与DHA组相比较进一步增加细胞内活性氧含量与脂质过氧化物含量,并且细胞膜形态完全破坏。FeSO_4能够增强DHA对GPX-4活性的抑制作用。结论 DHA通过芬顿样反应升高细胞内活性氧而最终诱导肿瘤细胞铁死亡。另外,外源性铁可以加速DHA发生芬顿样反应进而加速肿瘤细胞铁死亡的发生与发展。     

Ferroptosis at the crossroads of infection,aging and cancer

Despite significant developments and persistent efforts by scientists, cancer is one of the primary causes of human death worldwide. No form of life on Earth can survive without iron, although some species can live without oxygen. Iron presents a double‐edged sword. Excess iron is a risk for carcinogenesis, while its deficiency causes anemia, leading to oxygen shortage. Every cell is eventually destined to death, either through apoptosis or necrosis. Regulated necrosis is recognized in distinct forms. Ferroptosis is defined as catalytic Fe(II)‐dependent regulated necrosis accompanied by lipid peroxidation. The main observation was necrosis of fibrosarcoma cells through inhibition of cystine/glutamate antiporter with erastin, which reduced intracellular cysteine and, thus, glutathione levels. Our current understanding of ferroptosis is relative abundance of iron (catalytic Fe[II]) in comparison with sulfur (sulfhydryls). Thus, either excess iron or sulfur deficiency causes ferroptosis. Cell proliferation inevitably requires iron for DNA synthesis and energy production. Carcinogenesis is a process toward iron addiction with ferroptosis resistance. Conversely, ferroptosis is associated with aging and neurodegeneration. Ferroptosis of immune cells during infection is advantageous for infectious agents, whereas ferroptosis resistance incubates carcinogenic soil as excess iron. Cancer cells are rich in catalytic Fe(II). Directing established cancer cells to ferroptosis is a novel strategy for discovering cancer therapies. Appropriate iron regulation could be a tactic to reduce and delay carcinogenesis.     

Recent Advances in Pathology: the 2019 Annual Review Issue of The Journal of Pathology

In this Annual Review Issue of The Journal of Pathology, we present 15 invited reviews on topical aspects of pathology, ranging from the impacts of the microbiome in human disease through mechanisms of cell death and autophagy to recent advances in immunity and the uses of genomics for understanding, classifying and treating human cancers. Each of the reviews is authored by experts in their fields and our intention is to provide comprehensive updates in specific areas of pathology in which there has been considerable recent progress. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Oridonin induces ferroptosis by inhibiting gamma‐glutamyl cycle in TE1 cells

Oridonin (Ori) is a natural tetracyclic diterpenoid active compound with excellent antitumor activity, but the mechanism of Ori on esophageal cancer cell, TE1, remains unclear. In this study, we examined the levels of intracellular iron, malondialdehyde, and reactive oxygen species after Ori treatment, while interfering with the effects of Ori with ferroptosis inhibitor, demonstrating that Ori's inhibition of TE1 cell proliferation is associated with ferroptosis. To understand the molecular mechanism of Ori, we performed UPLC–MS/MS metabolomics profiling on TE1 cells, which show that gamma‐glutamyl amino acids (gamma‐glutamylleucine, gamma‐glutamylvaline), 5‐oxoproline, glutamate, GSH, and GSSG are changed significantly after Ori treatment. Meanwhile, the activity of gamma‐glutamyl transpeptidase 1 (GGT1) decreased. This revealed that Ori inhibited the gamma‐glutamyl cycle in TE1 cells. Furthermore, we found that Ori can covalently bind to cysteine to form the conjugate oridonin‐cysteine (Ori‐Cys), resulting in the inhibition of glutathione synthesis, which is consistent with the decrease in the enzymatic activity of glutamate cysteine ligase catalytic subunit (GCLC). Eventually, the value of intracellular GSH/GSSG was reduced, and the enzymatic activity of the glutathione peroxidase 4 (GPX4) was significantly decreased. In conclusion, our experiments indicated that Ori can inhibit the gamma‐glutamyl cycle, thereby inducing ferroptosis to exert anti‐cancer activity.     

MicroRNA-132通过诱导线粒体氧化应激障碍-铁死亡进程促进动脉粥样硬化

目的 探讨MicroRNA-132（miR-132）在动脉粥样硬化斑块中的表达及生物学意义。方法 收集在本医院行外周血管造瘘手术的动脉粥样硬化患者的斑块样本及周围正常血管样本各30例,分为实验组（n=30）与对照组（n=30）;利用RT-qPCR验证miR-132在30例组织标本中的表达水平;采用脂质体转染技术上调人脐静脉内皮细胞（HUVEC）中miR-132的表达,继而通过流式细胞及激光共聚焦技术分析过表达miR-132的HUVEC内活性氧（ROS）、ROS与线粒体的定位关系、线粒体活性氧超氧化物（mtROS）、线粒体膜电位状态（MMP）以及线粒体膜转换孔通透性（mPTP）的功能变化;通过ELISA检测HUVEC内线粒体氧化还原呼吸链复合体（Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ型）活性的状态;通过Western blot检测铁死亡关键蛋白的表达水平。结果 与正常血管样本（对照组）相比,miR-132在动脉粥样硬化斑块的表达水平显著上调（P<0.001）;相比于正常HUVEC,脂质体转染的HUVEC内miR-132表达量显著上升（P<0.001）,细胞内ROS明显增加（P<0.001）,且大部分ROS与线粒体存在共定位关系;同时于正常HUVEC,miR-132过表达的HUVEC细胞内MMP下降（P<0.001）、mtROS升高（P<0.001）、线粒体活性氧mPTP更多开放（P< 0.001）,继而引起线粒体氧化还原呼吸链应激障碍,铁死亡关键蛋白GPX4显著下调（P<0.001）、氧化蛋白NOX4显著增多（P< 0.001）。结论 MiR-132可通过诱导线粒体氧化应激障碍-铁死亡进程促进动脉粥样硬化,有望成为动脉粥样硬化的治疗靶点。     

小檗碱通过激活 Nrf2-HO-1/GPX4 通路抑制小鼠海马神经元HT22细胞的铁死亡

目的 探讨小檗碱对于Erastin诱导小鼠海马神经元HT22细胞的铁死亡的保护作用及其可能机制。方法 以HT22小鼠海马神经元细胞为研究对象,分为对照组、Erastin模型组、Erastin+30 μmol/L BBR组、Erastin+60 μmol/L BBR组。采用CCK-8法、特异性 Fe2+ 荧光探针、荧光染料（DAPI）检测和荧光探针（H2DCFH-DA）检测各实验组细胞的增殖情况、活性铁水平、细胞凋亡和活性氧（ROS）变化。 RT-qPCR和Western blot分别检测各实验组细胞的Nrf2、HO-1、GPX4 mRNA和蛋白表达情况。以60 μmol BBR的最适浓度来进一步探究其作用机制,分为对照组、Erastin模型组、Erastin+60 μmol/L BBR组、Erastin+60 μmol/LBBR+2 μmol Nrf2抑制剂 ML385组。通过使用荧光探针和Western blot检测Nrf2抑制剂（ML385）作用后的活性铁的水平、活性氧含量以及Nrf2、HO-1、GPX4蛋白的表达来验证小檗碱调节的Nrf2-HO-1/GPX4通路对Erastin处理的HT22细胞的保护作用。结果 0.5 μmol/L Erastin作用于HT22细胞8 h,细胞存活率与对照组相比显著被抑制（P<0.05）;同时细胞凋亡、ROS以及活性铁含量增加（P<0.05）。与Erastin组比较,Erastin+30 μmol/L BBR组和Erastin+60 μmol/L BBR组的细胞存活率明显升高（P<0.05）,同时显著降低细胞凋亡、ROS以及活性铁含量（P<0.05）。小檗碱增加 HT22细胞中Nrf2、HO-1、GPX4基因及蛋白的 表达量（P<0.05）。加入Nrf2抑制剂ML385后,Nrf2-HO-1/GPX4通路被抑制,并且ROS以及活性铁含量升高（P<0.05）。结论 Erastin诱导HT22细胞发生铁死亡,小檗碱抑制Erastin诱导的铁死亡,可能机制是激活了Nrf2-HO-1/GPX4通路。     

甘珀酸增强RSL3对耐顺铂睾丸癌细胞增殖、侵袭和迁移的抑制作用

目的 探讨铁死亡诱导剂RSL3对耐顺铂睾丸癌细胞（I-10/DDP）增殖、侵袭和迁移能力的影响以及甘珀酸对RSL3抗耐药睾丸癌活性的作用。方法 MTT法检测不同浓度RSL3（0、1、2、4、8、16、32 μmol/L）及合用甘珀酸（100 μmol/L）作用后I-10/DDP细胞的存活率、铁死亡抑制剂Fer-1（2 μmol/L）的作用下RSL3（4 μmol/L）及甘珀酸（100 μmol/L）合用RSL3（4 μmol/L）处理后I-10/DDP细胞的存活率。后续实验分为Control组、甘珀酸（100 μmol/L）组、RSL3（2 μmol/L）组、甘珀酸（100 μmol/L）合用RSL3（2 μmol/L）组,采用集落克隆实验检测细胞增殖能力、划痕实验和Transwell实验检测细胞侵袭与迁移能力。Western blot检测GPX4水平、C11 BODIPY 581/591荧光探针检测lipid 活性氧（ROS）水平、FerroOrange荧光探针检测Fe2+水平。结果 RSL3呈浓度依赖性降低I-10/DDP细胞存活率,且在RSL3浓度2、4、8 μmol/L 时,合用甘珀酸后细胞存活率显著降低（P<0.05）;与Control组相比,RSL3处理后I-10/DDP细胞的集落形成数减少、划痕愈合率减小（P=0.012）、侵袭和迁移细胞数减少（P<0.001）;与单用RSL3相比,甘珀酸合用RSL3处理后I-10/DDP细胞的集落形成数显著减少、划痕愈合率显著减小（P=0.005）、侵袭和迁移细胞数显著减少（P=0.001,P=0.002）。Fer-1降低单用RSL3、甘珀酸合用RSL3对I-10/DDP细胞增殖的抑制率（P<0.01）;与Control组相比,RSL3作用后细胞内GPX4水平降低（P=0.001）、lipid ROS 水平（P=0.001）和Fe2+水平升高;且与单用RSL3相比,甘珀酸合用RSL3处理后细胞内GPX4水平明显降低（P=0.01）、lipid ROS 水平（P=0.001）和Fe2+水平明显升高。结论 RSL3可诱导耐顺铂睾丸癌细胞发生铁死亡,并能抑制细胞增殖、侵袭和迁移能力;甘珀酸通过促进RSL3诱导的铁死亡从而增强RSL3的抑制作用。     

Ferrostatin-1通过抑制铁死亡延缓D-gal诱导的心肌细胞衰老的研究

目的 探讨D-半乳糖（D-gal）诱导的心肌细胞衰老是否存在铁死亡及铁死亡抑制剂Ferrostatin-1(Fer-1)能否延缓心肌细胞衰老。方法 通过不同水平（0、5、10、20、40、80、100 g/L）D-gal诱导H9C2心肌细胞损伤从而制备心脏衰老模型,采用MTT法检测细胞活力,确定后续实验采用的D-gal质量浓度。将细胞分为Control组、D-gal组和Fer-1组。MTT法检测细胞活力;DCFH-DA法检测细胞内活性氧（ROS）水平;微板法检测细胞内还原型谷胱甘肽（GSH）含量;硫代巴比妥酸法检测细胞内丙二醛（MDA）含量;Western blot检测溶质载体家族7成员11(SLC7A11)、谷胱甘肽过氧化物酶4(GPx4)、P53蛋白表达水平;微量法检测细胞内β-半乳糖苷酶（β-GAL）活性。结果 MTT法结果显示,细胞活力随D-gal质量浓度升高而降低（P<0.05）,后续实验采用D-gal质量浓度为20 g/L。与D-gal组相比,Fer-1组细胞活力增加（P<0.05）;与Control组相比,D-gal组中ROS、MDA含量、P53蛋白表达水平、...     

Artesunate alleviates intracerebral haemorrhage secondary injury by inducing ferroptosis in M1-polarized microglia and suppressing inflammation through AMPK/mTORC1/GPX4 pathway

Intracerebral haemorrhage (ICH) is a catastrophic subtype of stroke with severe morbidity and mortality. However, little progress has been made in the subsequent secondary injury. Artesunate, a water-soluble semi-synthetic derivative of artemisinin, exhibits remarkable pharmacological effects on anti-neuroinflammation. However, the effects of artesunate on ICH remain unknown. In the present study, haemoglobin (Hb) treatment in BV2 cell and collagenase type IV intracerebroventricular injection in Sprague–Dawley rats were used to establish in vitro and in vivo ICH models, respectively. For in vivo, the neurological scores, haematoma volume, brain oedema, inflammatory factors and iron deposition were evaluated. Besides, lipopolysaccharide (LPS) was used in in vitro to polarize BV2 cell to M1 phenotype. Cell viability, cellular reactive oxygen species (ROS), Fe²⁺ concentration, and lipid peroxidation levels, ferroptosis-associated proteins and mRNA, morphological of mitochondria were measured in vitro. Additionally, the AMP-activated protein kinase (AMPK)/mammalian/mechanistic target of rapamycin (mTOR) pathway were measured by western blot and immunofluorescence staining. The present in vivo results indicated that artesunate significantly ameliorated neurological deficits, haematoma volume and brain oedema in ICH rats. Besides, artesunate suppressed the M1-microglia relative inflammatory factors and up-regulated iron deposition. For in vitro, artesunate significantly selectively decreased the viability of LPS-stimulated BV2 cell. Furthermore, ROS and lipid peroxidation levels were up-regulated. And the glutathione peroxidase 4 (GPX4) were silenced via the AMPK/mTORC1 axis. Our finding supports that artesunate ameliorates the ICH secondary injury both in vitro and in vivo by inducing ferroptosis in microglia and further inhibiting inflammation mainly through the AMPK/mTORC1/GPX4 pathway. This finding may provide a novel target for ICH treatment.