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81.
Sylvain Hanein Mathilde Garcia Lucas Fares-Taie Valérie Serre Yves De Keyzer Thierry Delaveau Isabelle Perrault Nathalie Delphin Sylvie Gerber Alain Schmitt Jean-Marc Masse Arnold Munnich Josseline Kaplan Frédéric Devaux Jean-Michel Rozet 《Biochimica et Biophysica Acta (BBA)/General Subjects》2013
Background
Hereditary optic neuropathies (HONs) are a heterogeneous group of disorders that affect retinal ganglion cells (RGCs) and axons that form the optic nerve. Leber's Hereditary Optic Neuropathy and the autosomal dominant optic atrophy related to OPA1 mutations are the most common forms. Nonsyndromic autosomal recessive optic neuropathies are rare and their existence has been long debated. We recently identified the first gene responsible for these conditions, TMEM126A. This gene is highly expressed in retinal cellular compartments enriched in mitochondria and supposed to encode a mitochondrial transmembrane protein of unknown function.Methods
A specific polyclonal antibody targeting the TMEM126A protein has been generated. Quantitative fluorescent in situ hybridization, cellular fractionation, mitochondrial membrane association study, mitochondrial sub compartmentalization analysis by both proteolysis assays and transmission electron microscopy, and expression analysis of truncated TMEM126A constructs by immunofluorescence confocal microscopy were carried out.Results
TMEM126A mRNAs are strongly enriched in the vicinity of mitochondria and encode an inner mitochondrial membrane associated cristae protein. Moreover, the second transmembrane domain of TMEM126A is required for its mitochondrial localization.Conclusions
TMEM126A is a mitochondrial located mRNA (MLR) that may be translated in the mitochondrial surface and the protein is subsequently imported to the inner membrane. These data constitute the first step toward a better understanding of the mechanism of action of TMEM126A in RGCs and support the importance of mitochondrial dysfunction in the pathogenesis of HON.General significance
Local translation of nuclearly encoded mitochondrial mRNAs might be a mechanism for rapid onsite supply of mitochondrial membrane proteins. 相似文献82.
Ying Ma Shun-Xian Wang Yun Liu Guo-Guang Peng Xiao-Ming Wang Bo Zhang Bi-Hua Wu Ju-Ming Yu 《Gene》2013
Objectives
Ischemic stroke is influenced by both environmental and genetic factors. The CD40/CD40L system is related to proinflammatory and prothrombogenic responses, which are involved in the pathophysiology of ischemic stroke. The aim of this study was to evaluate association between the CD40 -1C/T single nucleotide polymorphism (SNP) and ischemic stroke in a Chinese population.Methods
We conducted a case–control study including 286 ischemic stroke patients and 336 controls. CD40 -1C/T SNP was genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing methods, and evaluated its relevance to ischemic stroke susceptibility.Results
Significantly increased ischemic stroke risk was found to be associated with the T allele of CD40 -1C/T (OR = 1.273, 95% CI = 1.016–1.594). The frequencies of CT and TT/CT genotypes of CD40 -1C/T in ischemic stroke patients were significantly higher than those of controls, respectively (for CT: OR = 2.350, 95% CI = 1.601–3.449; for TT/CT: OR = 2.148, 95% CI = 1.479–3.119). And, similar results were obtained after adjusting non-matched variables. We found that the frequency of carried T genotypes (TT and TT/CT) was significantly increased in patients with history of stroke compared with patients without (for TT: OR = 6.538, 95%CI = 1.655–25.833; for TT/CT: OR = 3.469, 95%CI = 1.031–11.670), respectively.Conclusions
The findings suggested that the CD40 -1C/T polymorphism might contribute to the susceptibility to ischemic stroke in the Chinese population, and might be associated with history of previous stroke. 相似文献83.
This study evaluated the effects of two different types of segmental/extra-segmental conditioning stimuli (tonic muscle pain and non-painful vibration) on the subjective experience (perceived pain intensity) and on the cortical evoked potentials to standardized test stimuli (cutaneous electrical stimuli). Twelve subjects participated in two separate sessions to investigate the effects of tonic muscle pain or cutaneous vibration on experimental test stimuli. The experimental protocol contained a baseline registration (test stimuli only), a registration with the test stimuli in combination with the conditioning stimuli, followed by a registration with the test stimuli only. In addition, the effects of the conditioning stimuli were examined at two anatomically separated locations (segmental and extra-segmental). Compared with the test stimulus alone, the perceived pain intensity and peak-to-peak amplitudes of the evoked potentials were unchanged in the presence of non-painful conditioning stimuli at either location. In contrast, a significant decrease of the perceived pain intensity and peak-to-peak amplitudes was found in the presence of painful conditioning stimuli at the extra-segmental sites. Moreover, the topographic maps of the 32-channel recordings suggested that the distribution of the scalp evoked potentials was almost symmetrical around the vertex Cz in the baseline registration. The evoked potentials were generally decreased during hypertonic saline infusion at the extra-segmental sites, but the distribution of the topographic maps did not appear to change. Vibration has previously been shown to inhibit pain, but in the present study the perceived intensity of phasic painful electrical stimuli was unchanged. The reduced perceived pain intensity and the smaller peak-to-peak amplitude of the evoked potential in the presence of extra-segmental conditioning pain are in accordance with the concept of diffuse noxious inhibitory control. 相似文献
84.
Monika Primon Peter C. Huszthy Helena Motaln Krishna M. Talasila Ana Torkar Rolf Bjerkvig Tamara Lah Turnšek 《Experimental cell research》2013
Despite improved treatment options, glioblastoma multiforme (GBM) remains the most aggressive brain tumour with the shortest post-diagnostic survival. Arsenite (As2O3) is already being used in the treatment of acute promyelocytic leukaemia (APL), yet its effects on GBM have not been evaluated in detail. In U87MG cell monolayers, we have previously shown that arsenite cytotoxicity significantly increases upon transient inhibition of lysosomal protease Cathepsin L (CatL). As multicellular spheroids more closely represent in vivo tumours, we aimed to evaluate the impact of permanent CatL silencing on arsenite treatment in U87MG spheroids. CatL was stably silenced using shRNA expression plasmid packed lentiviruses. By using metabolic- and cell viability assays, we demonstrated that long-term CatL silencing significantly increased arsenite cytotoxicity in U87MG spheroids. Silenced CatL also increased arsenite-mediated apoptosis in spheroids via elevated p53 expression, Bax/Bcl2 ratio and caspase 3/7 activity, though with lower efficacy than in monolayers. Arsenite cytotoxicity was enhanced by lower CatL activity, since similar cytotoxicity increase was also observed using the novel CatL inhibitor AT094. The results have significant translational impact, since stable CatL silencing would enable the application of lower systemic doses of arsenite to achieve the desired cytotoxic effects on GBMs in vivo. 相似文献
85.
Mi Li Xiubin Xiao Lianqing Liu Ning Xi Yuechao Wang Zaili Dong Weijing Zhang 《Experimental cell research》2013
CD20, a membrane protein highly expressed on most B-cell lymphomas, is an effective target demonstrated in clinical practice for treating B-cell non-Hodgkin's lymphoma (NHL). Rituximab is a monoclonal antibody against CD20. In this work, we applied atomic force microscopy (AFM) to map the nanoscale distribution of CD20 molecules on the surface of cancer cells from clinical B-cell NHL patients under the assistance of ROR1 fluorescence recognition (ROR1 is a specific cell surface marker exclusively expressed on cancer cells). First, the ROR1 fluorescence labeling experiments showed that ROR1 was expressed on cancer cells from B-cell lymphoma patients, but not on normal cells from healthy volunteers. Next, under the guidance of ROR1 fluorescence, the rituximab-conjugated AFM tips were moved to cancer cells to image the cellular morphologies and detect the CD20-rituximab interactions on the cell surfaces. The distribution maps of CD20 on cancer cells were constructed by obtaining arrays of (16×16) force curves in local areas (500×500 nm2) on the cell surfaces. The experimental results provide a new approach to directly investigate the nanoscale distribution of target protein on single clinical cancer cells. 相似文献
86.
Pin Guo Quanmin Nie Jin Lan Jianwei Ge Yongming Qiu Qing Mao 《Biochemical and biophysical research communications》2013
The c-Myc oncogene is amplified in many tumor types. It is an important regulator of cell proliferation and has been linked to altered miRNA expression, suggesting that c-Myc-regulated miRNAs might contribute to tumor progression. Although miR-26a has been reported to be upregulated in glioblastoma multiforme (GBM), the mechanism has not been established. We have shown that ectopic expression of miR-26a influenced cell proliferation by targeting PTEN, a tumor suppressor gene that is inactivated in many common malignancies, including GBM. Our findings suggest that c-Myc modulates genes associated with oncogenesis in GBM through deregulation of miRNAs via the c-Myc–miR-26a–PTEN signaling pathway. This may be of clinical relevance. 相似文献
87.
Atsushi Iwai Takuya Shiozaki Tadaaki Miyazaki 《Biochemical and biophysical research communications》2013
Apoptosis is an important mechanism to maintain homeostasis in mammals, and disruption of the apoptosis regulation mechanism triggers a range of diseases, such as cancer, autoimmune diseases, and developmental disorders. The severity of influenza A virus (IAV) infection is also closely related to dysfunction of apoptosis regulation. In the virus infected cells, the functions of various host cellular molecules involved in regulation of induction of apoptosis are modulated by IAV proteins to enable effective virus replication. The modulation of the intracellular signaling pathway inducing apoptosis by the IAV infection also affects extracellular mechanisms controlling apoptosis, and triggers abnormal host responses related to the disease severity of IAV infections. This review focuses on apoptosis related molecules involved in IAV replication and pathogenicity, the strategy of the virus propagation through the regulation of apoptosis is also discussed. 相似文献
88.
Ryushi Kawakami Haruhiko Sakuraba Toshihisa Ohshima 《Bioscience, biotechnology, and biochemistry》2013,77(12):2045-2050
We previously found a very large NAD-dependent glutamate dehydrogenase with approximately 170?kDa subunit from Janthinobacterium lividum (Jl-GDH) and predicted that GDH reaction occurred in the central domain of the subunit. To gain further insights into the role of the central domain, several single point mutations were introduced. The enzyme activity was completely lost in all single mutants of R784A, K810A, K820A, D885A, and S1142A. Because, in sequence alignment analysis, these residues corresponded to the residues responsible for glutamate binding in well-known small GDH with approximately 50?kDa subunit, very large GDH and well-known small GDH may share the same catalytic mechanism. In addition, we demonstrated that C1141, one of the three cysteine residues in the central domain, was responsible for the inhibition of enzyme activity by HgCl2, and HgCl2 functioned as an activating compound for a C1141T mutant. At low concentrations, moreover, HgCl2 was found to function as an activating compound for a wild-type Jl-GDH. This suggests that the mechanism for the activation is entirely different from that for the inhibition. 相似文献
89.
Pluronic F68 is one of the most used shear protecting additives in cell culture cultivations. It is well known from literature that such surface‐active surfactants lower the surface tension at the gas‐liquid interface, which influences the mass transfer. In this study, the effect of Pluronic F68 on oxygen mass transfer in aqueous solutions was examined. Therefore, the gassing in/gassing out method and bubble size measurements were used. At low concentrations of 0.02 g/L, a 50% reduction on mass transfer was observed for all tested spargers and working conditions. An explanation of the observed effects by means of Higbie's penetration or Dankwerts surface renewal theory was applied. It could be demonstrated that the suppressed movement of the bubble surface layer is the main cause for the significant drop down of the kLa‐values. For Pluronic F68 concentrations above 0.1 g/L, it was observed that it comes to changes in bubble appearance and bubble size strongly dependent on the sparger type. By using the bubble size measurement data, it could be shown that only small changes in mass transfer coefficient (kL) take place above the critical micelle concentration. Further changes on overall mass transfer at higher Pluronic F68 concentrations are mainly based on increasing of gas holdup and, more importantly, by increasing of the surface area available for mass transfer. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:1278–1288, 2013 相似文献
90.
目的:比较化疗敏感性不同弥漫性大B细胞淋巴瘤的蛋白质表达差异,寻找可反映大B细胞淋巴瘤化疗敏感性的标志物。方法:通过肿瘤药物敏感试验选取化疗高敏感性和低敏感性大B细胞淋巴瘤组织,进行蛋白质组学比较研究后得出差异表达蛋白;对在高敏感组中高表达的埃兹蛋白(Ezrin)进一步行免疫印迹验证,应用免疫组化技术检测在临床病例中的表达情况。结果:建立了化疗高敏感和低敏感大B细胞淋巴瘤差异表达蛋白质凝胶2D图谱,鉴定了28种差异表达蛋白,发现Ezrin蛋白在化疗高敏感组表达高于低敏感组,免疫印迹和免疫组化结果也进一步证实了Ezrin的这一表达状态。结论:Ezrin蛋白表达在化疗敏感性不同大B细胞淋巴瘤中存在差别,可能作为预测淋巴瘤化疗敏感性的候选标志物。 相似文献