The effect of Fe2O3 and ZnO nanoparticles on cytotoxicity and glucose metabolism in lung epithelial cells

Metallic nanoparticles (NPs) have potential applications in industry and medicine, but they also have the potential to cause many chronic pulmonary diseases. Mechanisms for their cytotoxicity, glucose and energy metabolism responses need to be fully explained in lung epithelial cells after treatment with metallic nanoparticles. In our study, two different metallic nanoparticles (Fe₂O₃ and ZnO) and two cell‐based assays (BEAS‐2B and A549 cell lines) were used. Our findings demonstrate that ZnO nanoparticles, but not Fe₂O₃ nanoparticles, induce cell cycle arrest, cell apoptosis, reactive oxygen species (ROS) production, mitochondrial dysfunction and glucose metabolism perturbation, which are responsible for cytotoxicity. These results also suggest that the glucose metabolism and bioenergetics had a great potential in evaluating the cytotoxicity and thus were very helpful in understanding their underlying molecular mechanisms. Copyright © 2015 John Wiley & Sons, Ltd.     

纤恙螨属线粒体基因组研究进展

恙螨引起的恙虫病是世界上危害严重的一类人兽共患寄生虫病。本文综述现有纤恙螨属线粒体基因组信息,发现以下几个特点:纤恙螨属线粒体基因组与节肢动物以及前气门目其他物种的线粒体基因组排列发生了较大变化;红纤恙螨和地里纤恙螨有2个非编码区,苍白纤恙螨有4个非编码区;AT-偏斜为正值,但cox1第3位密码子的AT-偏斜和GC-偏斜与后生动物典型的链偏向相反;tRNA和rRNA基因的平均大小比部分寄螨总目物种要短,导致大部分tRNA基因具有非典型的二级结构。对纤恙螨属线粒体基因组的结构特征和变异情况进行比较,弥补了蜱螨亚纲线粒体基因组传统认识的不足和局限。     

N6-甲基腺嘌呤调控线粒体功能及其在代谢性疾病中的研究进展

N6-甲基腺嘌呤(6mA)是存在于真核生物中的表观遗传修饰,通过对线粒体DNA、非编码基因和核糖体DNA等进行修饰,进而动态调控转录。目前研究发现,6mA通过调节线粒体DNA的转录等影响线粒体活性和功能,进而参与代谢性疾病的发生发展。本文探讨6mA调控线粒体功能的机制及其在肥胖、动脉粥样硬化、高血压和癌症等代谢性疾病中的作用,有望为代谢相关疾病的防治提供新思路。     

Uncommon antinuclear antibody patterns as diagnostic indicators

IntroductionThe clinical significance of common antinuclear antibody (ANA) patterns, such as nuclear homogenous and nuclear speckled patterns with their corresponding specific antibodies, has already been established. However, the clinical relevance of these uncommon ANA patterns have not been well elucidated and these patterns are therefore not reported by most clinical laboratories. We herein report some retrospective data analysis linking patients’ clinical status to several uncommon ANA patterns.MethodsWe retrieved and assessed the patient records for ANA reports generated in our hospital over a period of two years. All testing had been performed using the gold standard Indirect Immunofluorescence Assay.ResultsRecords of 1235 consecutive patients tested for ANA were reviewed. ANA was positive in 330 of these patients with 6.39% found to have uncommon nuclear, cytoplasmic or mitotic sub-patterns. The mitotic spindle (0.89%), cytoplasmic anti-mitochondrial antibodies (0.80%), followed by discrete nuclear dots-multiple (0.72%) were the dominating patterns, with a higher prevalence in females than in males. Systemic lupus erythematosus and rheumatoid arthritis were the two most common autoimmune disorders associated with mitotic spindle fibers and nuclear centromere and nuclear large/coarse speckled ANA patterns.ConclusionThe prevalence of these relatively uncommon ANA patterns was higher than expected. Further evaluation of these patterns along with their corresponding antibodies and their clinical utility must be encouraged. We trust this endeavour will provide diagnostic information in autoimmune and other disease conditions.     

Ultrastructural Changes of Mitochondria in the Cultivated Skin Fibroblasts of Patients with Point Mutations in Mitochondrial DNA

Mitochondrial disorders represent a heterogeneous group of multisystem diseases with extreme variability in clinical phenotype. The diagnosis of mitochondrial disorders relies heavily on extensive biochemical and molecular analyses combined with morphological studies including electron microscopy. Although muscle is the tissue of choice for electron microscopic studies, the authors investigated cultivated human skin fibroblasts (HSF) harboring 3 different pathologic mtDNA mutations: 3243A > G, 8344A > G, 8993T > G. They addressed to the possibility of whether mtDNA mutations influence mitochondrial morphology in HSF and if ultrastructural changes of mitochondria may be used for differential diagnostics of mitochondrial disorders caused by mtDNA mutations. Ultrastructural analysis of patients' HSF revealed a heterogeneous mixture of mainly abnormal, partially swelling mitochondria with unusual and sparse cristae. The most characteristic cristal abnormalities were heterogeneity in size and shapes or their absence. Typical filamentous and branched mitochondria with numerous cristae as appeared in control HSF were almost not observed. In all lines of cultured HSF with various mtDNA mutations, similar ultrastructural abnormalities and severely changed mitochondrial interior were found, although no alterations in function and amount of OXPHOS were detected by routinely used biochemical methods in two lines of cultured HSF. This highlights the importance of morphological analysis, even in cultured fibroblasts, in diagnostics of mitochondrial disorders.     

MT‐ND5 Mutation Causing Exercise Intolerance Displays Intercellular Heteroplasmy and Rapid Shifts Between Generations

We studied the inheritance and cellular segregation of a maternally inherited, heteroplasmic MT‐ND5 mutation, m.13271T>C, previously shown to cause only exercise intolerance despite being present in multiple tissues. The mutation was present at low levels in early passage, bulk muscle culture, but on subcloning, only homoplasmic clones were found. Studies of transmission showed that the mutation expanded from very low levels in the patient's mother to higher levels in the patient, particularly skeletal muscle, but was not found in the placenta and umbilical cord blood of her child. Our study suggests that the m.13271T>C is either already strictly segregated (intercellular heteroplasmy), or moves rapidly to this state in cultured cells. Transmission studies suggest that intercellular heteroplasmy may also be present in the patient's germline. Although rapid shifts in heteroplasmic mitochondrial DNA mutations reflect a bottleneck in the female germline, complete segregation will accentuate the effects of this and further complicate genetic counseling.     

Apoptosis of lung cells regulated by mitochondrial signal pathway in crotonaldehyde‐induced lung injury

Crotonaldehyde, a highly toxic α, β‐unsaturated aldehyde, is a ubiquitous hazardous pollutant. Because of its extreme toxicity and ubiquity in all types of smoke, most current research focuses on the lung toxicity of such air pollutants. However, the specific mechanism of pulmonary toxicity caused by crotonaldehyde remains unclear, especially after long‐term exposure to crotonaldehyde at low dose. Therefore, the aim of the present study is to determine whether crotonaldehyde‐induced oxidative damage and inflammation promote apoptosis in rats via the mitochondrial pathway using histopathology, immunohistochemistry, biochemistry analysis and Western blot analysis. The results show that crotonaldehyde elicited oxidative damage and inflammation in rats in a concentration‐dependent manner. Crotonaldehyde‐induced lung injury which was confirmed by H&E, Masson's trichrome staining and TUNEL. And crotonaldehyde‐induced lung cell apoptosis showed a concentration‐response relationship. Immunohistochemistry and Western blot results showed that apoptotic mitochondrial signaling pathway is abnormally activated in crotonaldehyde‐induced lung injury. Collectively, this study demonstrates that exposure of rats to crotonaldehyde induces lung injury by inducing apoptosis, which is related to oxidative damage and inflammation through mitochondrial pathway.     

小檗碱通过破坏线粒体功能选择性诱导淋巴瘤细胞的凋亡

目的研究小檗碱(BBR)对T淋巴瘤细胞凋亡的影响及机制。方法正常T淋巴细胞、T淋巴瘤细胞、Jurkat细胞用BBR 0,10,20和40μmol·L^-1处理24 h,多柔比星(Dox)40μmol·L^-1为阳性对照;Jurkat p0细胞用BBR 0和40μmol·L^-1处理24 h。流式细胞术检测细胞凋亡率,Seahorse XF24细胞代谢分析仪和H2DCFDA活性氧探针检测细胞氧消耗率(OCR)和活性氧(ROS)水平。CellTiter-Glo发光法细胞活力检测试剂盒检测细胞ATP水平,试剂盒测线粒体呼吸链复合物Ⅰ,Ⅱ,Ⅳ和Ⅴ的活性。Western印迹法检测细胞内胱天蛋白酶3、Bcl-2、Bax、NF-κB抑制蛋白激酶α/β(IKKα/β)、磷酸化IKKα/β(p-IKKα/β)、NF-κB抑制因子α(IκBα)、p-IκBα和P65蛋白表达水平。结果BBR 40 mmol·L^-1明显增加T淋巴瘤细胞和Jurkat细胞凋亡率(P<0.01),胱天蛋白酶3和Bax蛋白表达水平显著上调(P<0.01),Bcl-2表达显著下调(P<0.01),但对正常T淋巴细胞的凋亡并无影响;BBR 40 mmol·L^-1明显降低Jurkat细胞的OCR及线粒体呼吸链复合物Ⅰ活性(P<0.01),增加ROS水平(P<0.01),降低ATP水平(P<0.01),但不影响线粒体缺陷型淋巴瘤Jurkat p0细胞呼吸链和凋亡;BBR 40μmol·L-1明显下调Jurkat细胞中NF-κB通路相关蛋白p-IKKα/β/IKKα/β、p-IκBα/IκBβ和核内P65表达(P<0.01)。结论BBR通过破坏线粒体功能选择性诱导淋巴瘤T细胞的凋亡,可能与抑制NF-κB通路有关。