Protein tyrosine phosphatase 1 protects human pancreatic cancer from erastin-induced ferroptosis

BackgroundPancreatic ductal adenocarcinoma (PDAC) is a fatal malignancy due to the lack of early detection method, therapeutic drug and target. We noticed that the expression of Protein Tyrosine Phosphatase Mitochondria1(PTPMT1) is upregulated in PDAC. However, its role in pancreatic cancer remains unknown.MethodsWe first analyzed the expression of PTPMT1 from 50 PDAC patients. Secondly, the survival proportions of different PTPMT1-expressed patients were analyzed. Then, the role and mechanism of PTPMT1 in PDAC were studied by lentivirus transduction system.ResultsPTPMT1 was upregulated in PDAC and patients with high PTPMT1 expression displayed lower overall survival rate. Knockdown of PTPMT1 increased the sensitivity to erastin or RSL3 induced ferroptosis. Mechanically, knockdown of PTPMT1 resulted in upregulated Acyl-CoA Synthetase Long Chain Family Member 4 (ACSL4) and downregulated Solute Carrier Family 7 Member 11 (SLC7A11). In addition, SLC7A11 was upregulated in PDAC tumor tissue and correlated positively with the expression of PTPMT1. However, the expression of ACSL4 was downregulated in PDAC and negatively correlated with the expression of PTPMT1.ConclusionOur study demonstrates that PTPMT1 is upregulated in PDAC and PTPMT1 inhibits ferroptosis by suppressing the expression of ACSL4 and upregulating SLC7A11 in Panc-1 cells, suggesting PTPMT1 might be a potential prognosis biomarker and therapeutic target in PDAC.     

基于Nrf2通路研究通腑养髓方调控Wilson病模型TX小鼠神经细胞铁死亡的机制

目的 基于核因子E2相关因子2(nuclear factor erythroid 2- related factor,Nrf2)信号通路观察通腑养髓方对Wilson病(Wilsons disease, WD)模型TX小鼠神经细胞铁死亡的干预效应,并探讨通腑养髓方对WD神经细胞损伤的保护机制。方法 以DL小鼠为正常对照,将TX小鼠随机分为模型组和通腑养髓方组,通腑养髓方组以通腑养髓方中药灌胃治疗30 d,模型组和对照组小鼠以生理盐水灌胃,末次灌胃后取各组小鼠脑组织。采用电感耦合等离子体质谱法检测小鼠脑组织铜、铁微量元素含量,免疫荧光染色技术检测小鼠脑组织转铁蛋白受体（transferrin receptor, TfR）表达水平,比色法检测小鼠脑组织超氧化物歧化酶（superoxide dismutase, SOD）活性和丙二醛（malondialdehyde, MDA）含量,透射电子显微镜观察小鼠脑组织细胞线粒体形态变化,Fluoro-Jade B（FJB）染色观察小鼠神经细胞损伤程度,Western blot法检测小鼠脑组织铁死亡及Nrf2信号通路相关蛋白［Nrf2,铁蛋白重链（ferritin heavy chain,FTH1）、血红素加氧酶1（heme oxygenase 1,HO1）、醌氧化还原酶1（NADPH quinone oxidoreductase 1,NQO1）］表达水平。结果 与正常对照组比较,模型组小鼠脑内铜、铁含量,TfR表达水平,MDA含量显著升高（P<0.05）,SOD活性显著下降（P＜0.05）;与模型组比较,通腑养髓方组小鼠脑内铁含量,TfR表达水平,MDA含量显著降低（P＜0.05）,SOD活性显著升高（P＜0.05）。模型组小鼠脑组织线粒体膜皱缩,嵴数量减少或消失,空泡产生;通腑养髓方组小鼠脑组织线粒体结构损伤程度明显减轻。与正常对照组比较,模型组小鼠神经细胞损伤程度显著增加（P<0.05）;与模型组比较,通腑养髓方组神经细胞损伤程度显著减少（P<0.05）。模型组小鼠脑内谷胱甘肽过氧化物酶4（glutathione peroxidase 4,GPX4）表达水平较正常对照组显著降低（P< 0.05）,通腑养髓方组脑内GPX4表达水平较模型组显著升高（P<0.05）。模型组小鼠脑内Nrf2、FTH1、HO1、NQO1表达水平较正常对照组显著降低（P<0.05）,通腑养髓方组脑内Nrf2、FTH1、HO1、NQO1表达水平较模型组显著增加（P<0.05）。结论 通腑养髓方通过上调TX小鼠神经细胞GPX4等铁死亡相关蛋白及Nrf2、FTH1、HO1、NQO1等Nrf2通路相关蛋白的表达水平,减轻铜蓄积所致的氧化应激,抑制神经细胞铁死亡,从而起到保护神经细胞的作用。     

葛根素对索拉非尼心肌毒性的保护及作用机制

目的 探讨葛根素通过抑制心肌铁死亡对索拉非尼心肌毒性的保护及其分子作用机制。 方法 细胞实验:分离培养大鼠乳鼠原代心肌细胞,给予不同的药物处理,分为二甲基亚砜(DMSO)组、索拉非尼组、索拉非尼+Ferrostatin-1(Fer-1)组、索拉非尼+去铁胺组、索拉非尼+葛根素组,检测各组细胞活力和乳酸脱氢酶(LDH)释放,观察光镜下细胞形态,并检测脂质活性氧(ROS)水平以及脂质过氧化代谢产物丙二醛(MDA)水平;采用Western blotting法检测上述分组以及索拉非尼处理心肌细胞0、12、24、36、48、60、72 h后内质网应激标志物葡萄糖调节蛋白(GRP78)水平。给予不同的药物处理,将心肌细胞分为索拉非尼组、索拉非尼+葛根素组、索拉非尼+毒胡萝卜素组以及索拉非尼+葛根素+毒胡萝卜素,检测各组细胞活力、LDH释放、MDA水平,采用Western blotting法检测GRP78水平。小鼠实验:将40只C57BL/6J小鼠随机分为对照组、葛根素组、索拉非尼组、索拉非尼+葛根素组,采用ELISA法检测血浆肌酸激酶同工酶(CK-MB)水平,测算心脏质量/胫骨长度(HW/TL)、心肌组织切片Masson染色后测量心肌细胞横截面积(CSA),检测心肌组织ROS、MDA水平,采用Western blotting法检测心肌组织GRP78水平。 结果 细胞实验中索拉非尼组较DMSO组细胞活力降低、LDH释放增加,细胞空泡化,脂质ROS及MDA水平升高,GRP78蛋白上调,差异均有统计学意义(P均<0.01);与索拉非尼组相比,索拉非尼+ Fer-1组、索拉非尼+去铁胺组以及索拉非尼+葛根素组细胞活力升高、LDH释放减少、空泡化减轻,脂质ROS及MDA水平降低,且GRP78蛋白下调,差异均有统计学意义(P均<0.05);内质网应激诱导剂毒胡萝卜素和葛根素对GRP78水平、细胞活力、LDH释放、MDA水平的交互作用差异有统计学意义(P均<0.05)。小鼠实验中索拉非尼组较对照组CK-MB水平升高,HW/TL下降,CSA升高,脂质ROS和MDA水平升高,GRP78蛋白上调,差异均有统计学意义(P均<0.01);葛根素与索拉非尼间的交互作用差异有统计学意义(P均<0.05);与索拉非尼组相比,索拉非尼+葛根素组小鼠CK-MB水平下降、HW/TL升高,CSA下降,脂质ROS和MDA水平降低,GRP78蛋白下调,差异均有统计学意义(P均<0.05)。 结论 葛根素可以抑制索拉非尼引发的心肌铁死亡,对索拉非尼的心肌毒性具有良好的保护作用,毒胡萝卜素可拮抗葛根素的细胞保护和抑制脂质过氧化作用,葛根素通过清除脂质ROS抑制内质网应激可能是其背后主要的分子机制。     

天然药物成分干预铁死亡抑制肿瘤的作用研究进展

铁死亡是一种铁依赖的程序性死亡,不同于传统的细胞死亡方式（如凋亡、焦亡、坏死、自噬）,其特征是活性氧诱导脂质过氧化物堆积。铁死亡在肿瘤发生发展中发挥着重要的调控作用。最新研究表明,天然药物成分可通过谷胱甘肽/谷胱甘肽过氧化物酶4途径、铁代谢、脂质代谢等调控机制诱导肿瘤细胞铁死亡。研究发现了30多种天然药物成分具有诱导肿瘤细胞铁死亡的作用,且有多通路、多靶点的特点。本文综述了天然药物成分通过干预铁死亡抑制肿瘤的作用研究进展。     

铁死亡调控机制及其在卵巢癌中的研究进展

卵巢癌作为一种恶性程度极高的女性生殖系统肿瘤,其死亡率在妇科恶性肿瘤中高居首位。卵巢癌发病隐匿,早期缺乏特异检测手段,在中晚期阶段往往发展为复发性及多重耐药性疾病,预后较差。近年来相关研究发现,铁死亡在卵巢癌的发生、发展中起着重要作用。许多学者认为铁死亡作为一种铁依赖性的细胞死亡方式,与多种生物化学过程密切相关,可以通过剥夺癌细胞内的铁或者改变肿瘤组织铁离子代谢方式,抑制肿瘤组织增殖,将其视为卵巢癌的潜在治疗靶点。现就铁死亡的生化过程及其在卵巢癌中的研究进展进行综述,为卵巢癌的治疗提供新思路。     

铁离子与铁死亡:衰老研究领域的新大陆

铁死亡是新发现的形态、生化、遗传上有别于传统死亡方式的调节性细胞坏死方式,以铁离子依赖的脂质过氧化过程为标识,在多种疾病（如神经退行性疾病和癌症）进程中发挥着至关重要的作用。在铁死亡过程中,铁离子扮演着关键性的角色（包括构成脂质过氧化酶和催化细胞内的氧化还原反应等）;且铁离子的吸收、运输、储存、利用等过程均会影响铁死亡的敏感性。随着铁离子和铁死亡关系研究的深入,衰老研究领域也不断取得新进展:在衰老过程中,神经细胞内铁离子的过度积累触发铁死亡,导致神经退行性疾病的发生;而衰老细胞内过量的铁离子则可以阻碍自噬,逃避铁死亡,加速衰老过程。毋庸置疑,铁离子与铁死亡在衰老过程中神秘的关系为衰老研究领域开辟了新大陆。然而,目前国内未见相关综述报道,本文将近年来铁死亡和铁离子在衰老研究中的最新进展做一综述,以期为铁离子与铁死亡在衰老过程中作用机制的研究提供新思路。     

肝移植围术期诱发肠损伤铁死亡的研究新进展

铁死亡（ferroptosis）是近年来新发现的,以铁依赖性的脂质活性氧（lipid reactive oxygen species,L-ROS）过度积累为特征的一种新的细胞程序性死亡方式,其与铁代谢、脂质代谢和氨基酸代谢等多种代谢调控途径相关。本文概述铁死亡相关概念、形态及生化特征、调控机制,以及铁死亡在肝移植围术期...     

单肺通气时非通气侧肺持续中低流量给氧在老年患者肺癌根治术中的应用

目的探讨单肺通气(OLV)时非通气侧肺持续中低流量给氧对老年患者肺癌根治术中肺泡巨噬细胞(AM)铁死亡的影响。方法选择2019年12月至2020年8月择期行胸腔镜下肺癌根治术的老年患者60例,男31例,女29例,年龄65～80岁,BMI 18～25 kg/m~2,ASAⅡ或Ⅲ级。采用随机数字表法将患者分为两组:观察组和对照组,每组30例。OLV时观察组非通气侧肺给予1～4 L/min持续性中低流量给氧,对照组非通气侧肺不给予持续性中低流量给氧。于术前(T_0,基础值)、麻醉诱导后即刻(T_1)、OLV后30 min (T_2)、1 h (T_3)、2 h (T_4)采集桡动脉血并测定SpO_2、PaO_2和PaCO_2,计算氧合指数(OI=PaO_2/FiO_2)。记录术前一秒用力呼气容积(FEV_1)/用力肺活量(FVC)比值。T_3时采集支气管肺泡灌洗液(BALF),采用流式细胞术分选AM,比色法测定AM内Fe~(2+)、丙二醛(MDA)浓度和超氧化物歧化酶(SOD)活性,Western blot法检测AM内长链脂酰辅酶A合成酶4(ACSL4)及谷胱甘肽过氧化物酶4(GPX4)蛋白含量。T_3时切取肺癌周边正常肺组织,采用HE染色,光镜下观察肺组织病理学并进行肺组织损伤评分。记录PACU停留时间和住院时间,记录肺部并发症以及呼吸抑制、窦性心动过缓、窦性心动过速、高血压、低血压、恶心呕吐等不良事件发生情况。结果与T_0时比较,两组T_1—T_4时SpO_2明显升高(P0.05),T_1时PaCO_2明显降低(P0.05);对照组T_1和T_3时PaO_2明显升高(P0.05),T_2—T_4时PaCO_2明显升高(P0.05),T_1时OI明显升高(P0.05),T_2—T_3时OI明显降低(P0.05);观察组T_1—T_4时PaO_2明显升高(P0.05),T_3时PaCO_2明显降低(P0.05),T_1、T_3、T_4时OI明显升高(P0.05)。与对照组比较,观察组T_2—T_4时SpO_2、PaO_2和OI明显升高(P0.05),PaCO_2明显降低(P0.05);T_3时肺损伤评分明显降低(P0.05),AM内Fe~(2+)、MDA浓度明显降低(P0.05),SOD活性明显升高(P0.05),ACSL4蛋白含量明显降低(P0.05),GPX4蛋白含量明显升高(P0.05);术后住院时间明显缩短(P0.05),肺部并发症发生率明显降低(P0.05)。两组PACU停留时间以及不良事件发生率差异无统计学意义。对照组肺泡壁增厚、水肿,可见大量中性粒细胞和单核细胞,肺泡腔内可见较多炎性渗出,肺间质明显增生可见大量炎性细胞浸润。观察组肺泡间隔增宽,毛细血管未见明显充血,小部分肺泡腔可见红细胞及炎性渗出液,肺间质炎性细胞浸润明显减少。结论老年患者胸腔镜下肺癌根治术中非通气侧肺持续中低流量给氧可减轻非通气侧肺损伤,其机制可能与抑制AM铁死亡有关。     

Ferroptosis: a promising target for cancer immunotherapy

Ferroptosis is a recently recognized type of programmed cell death and emerges to play an important role in cancer biology and therapies. This unique form of cell death, characterized by iron-dependent lipid peroxidation, is exquisitely regulated by the cellular metabolic networks such as lipid, iron and amino acid metabolism. The sensitivity to ferroptosis varies among different tumors. Recent evidence reveals that triple-negative breast cancer (TNBC), a highly aggressive disease with limited effective targeted therapies is particularly vulnerable to ferroptosis inducers, suggesting this new form of non-apoptotic cell death as an attractive target for the treatment of the “difficult-to-treat” tumor. Intriguingly, ferroptosis has recently been implicated to be involved in T cell-mediated anti-tumor immunity and affect the efficacy of cancer immunotherapy. Better understanding of this ferroptotic cell death will shed light on the discovery of novel combination therapeutic strategies for cancer treatment. Herein, we provide an overview of the key hallmarks of ferroptosis, use TNBC as a model to characterize the regulation of ferroptosis in cancer, and highlight ferroptosis-modulating combination therapeutic strategies in the context of cancer immunotherapy.     

Prognostic implications of ferroptosis-associated gene signature in colon adenocarcinoma

BACKGROUNDColon adenocarcinoma (COAD) is one of the most common and fatal malignant tumors, which increases the difficulty of prognostic predictions. Thus, new biomarkers for the diagnosis and prognosis of COAD should be explored. Ferroptosis is a recently identified programmed cell death process that has the characteristics of iron-dependent lipid peroxide accumulation. However, the predictive value of ferroptosis-related genes (FRGs) for COAD still needs to be further clarified. AIMTo identify some critical FRGs and construct a COAD patient prognostic signature for clinical utilization. METHODSThe Cancer Genome Atlas database (TCGA) and Gene Expression Omnibus databases were the data sources for mRNA expression and corresponding COAD patient clinical information. Differentially expressed FRGs were recognized using R and Perl software. We constructed a multi-FRG signature of the TCGA-COAD cohort by performing a univariate Cox regression and least absolute shrinkage and selection operator Cox regression analysis. COAD patients from the Gene Expression Omnibus cohort were utilized for verification. RESULTSOur research showed that most of the FRGs (85%) were differentially expressed between the corresponding adjacent normal tissues and cancer tissues in the TCGA-COAD cohort. Seven FRGs were related to overall survival (OS) in the univariate Cox analysis (all P < 0.05). A model with five FRGs (AKR1C1, AKR1C3, ALOX12, CRYAB, and FDFT1) was constructed to divide patients into high- and low-risk groups. The OS of patients in the high-risk group was significantly lower than that of the low-risk group (all P < 0.01 in the TCGA and Gene Expression Omnibus cohorts). The risk score was an independent prognosticator of OS in the multivariate Cox analysis (hazard ratio > 1, P < 0.01). The predictive capacity of the model was verified by a receiver operating characteristic curve analysis. In addition, a nomogram based on the expression of five hub FRGs and risk score can precisely predict the OS of individual COAD cancer patients. Immune correlation analysis and functional enrichment analysis results revealed that immunology-related pathways were abundant, and the immune states of the high-risk group and the low-risk group were different.CONCLUSIONIn conclusion, a novel five FRG model can be utilized for predicting prognosis in COAD. Targeting ferroptosis may be a treatment option for COAD.