28 research outputs found

    Potential involvement of F0F1-ATP(synth)ase and reactive oxygen species in apoptosis induction by the antineoplastic agent erucylphosphohomocholine in glioblastoma cell lines: A mechanism for induction of apoptosis via the 18 kDa mitochondrial translocator protein

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    Erucylphosphohomocholine (ErPC3, Erufosine™) was reported previously to induce apoptosis in otherwise highly apoptosis-resistant malignant glioma cell lines while sparing their non-tumorigenic counterparts. We also previously found that the mitochondrial 18 kDa Translocator Protein (TSPO) is required for apoptosis induction by ErPC3. These previous studies also suggested involvement of reactive oxygen species (ROS). In the present study we further investigated the potential involvement of ROS generation, the participation of the mitochondrial respiration chain, and the role of the mitochondrial FOF1-ATP(synth)ase in the pro-apoptotic effects of ErPC3 on U87MG and U118MG human glioblastoma cell lines. For this purpose, cells were treated with the ROS chelator butylated hydroxyanisole (BHA), the mitochondrial respiration chain inhibitors rotenone, antimycin A, myxothiazol, and the uncoupler CCCP. Also oligomycin and piceatannol were studied as inhibitors of the FO and F1 subunits of the mitochondrial FOF1-ATP(synth)ase, respectively. BHA was able to attenuate apoptosis induction by ErPC3, including mitochondrial ROS generation as determined with cardiolipin oxidation, as well as collapse of the mitochondrial membrane potential (Δψm). Similarly, we found that oligomycin attenuated apoptosis and collapse of the Δψm, normally induced by ErPC3, including the accompanying reductions in cellular ATP levels. Other inhibitors of the mitochondrial respiration chain, as well as piceatannol, did not show such effects. Consequently, our findings strongly point to a role for the FO subunit of the mitochondrial FOF1-ATP(synth)ase in ErPC3-induced apoptosis and dissipation of Δψm as well as ROS generation by ErPC3 and TSPO

    Brassinosteroids participate in the control of basal and acquired freezing tolerance of plants

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    Brassinosteroids (BRs) are growth-promoting plant hormones that play a role in abiotic stress responses, but molecular modes that enable this activity remain largely unknown. Here we show that BRs participate in the regulation of freezing tolerance. BR signaling-defective mutants of Arabidopsis thaliana were hypersensitive to freezing before and after cold acclimation. The constitutive activation of BR signaling, in contrast, enhanced freezing resistance. Evidence is provided that the BR-controlled basic helix–loop–helix transcription factor CESTA (CES) can contribute to the constitutive expression of the C-REPEAT/DEHYDRATION-RESPONSIVE ELEMENT BINDING FACTOR (CBF) transcriptional regulators that control cold responsive (COR) gene expression. In addition, CBF-independent classes of BR-regulated COR genes are identified that are regulated in a BR- and CES-dependent manner during cold acclimation. A model is presented in which BRs govern different cold-responsive transcriptional cascades through the posttranslational modification of CES and redundantly acting factors. This contributes to the basal resistance against freezing stress, but also to the further improvement of this resistance through cold acclimation

    Sexual Counseling in Patients With Heart Failure A Silent Phenomenon: Results From a Convergent Parallel Mixed Method Study

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    Background: Patients with heart failure (HF) often worry about resuming sexual activity and may need information. Nurses have a role in helping patients to live with the consequences of HF and can be expected to discuss patients sexual concerns. Objective: The aims of this study were to identify whether nurses discuss consequences of HF on sexuality with patients and to explore their perceived role and barriers regarding this topic. Methods: A cross-sectional research design with a convergent parallel mixed method approach was used combining qualitative and quantitative data collected with a self-reported questionnaire. Results: Nurses in this study rarely addressed sexual issues with their patients. The nurses did not feel that discussing sexual concerns with their patients was their responsibility, and only 8% of the nurses expressed confidence to do so. The main phenomenon in discussing sexual concerns seems to be one of silence: Neither patients nor nurses talk about sexual concerns. Factors influencing this include structural barriers, lack of knowledge and communication skills, as well as relevance of the topic and relationship to patients. Conclusion: Cardiac nurses in Germany rarely practice sexual counseling. It is a phenomenon that is silent. Education and skill-based training might hold potential to break the silence.Funding Agencies|Heart Failure Association of the European Society of Cardiology</p

    Das Beste aus zwei Welten | Wie etablierte Unternehmen und Start-ups Märkte erschließen

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    Established companies and start-ups act very differently on their respective markets. The particular differences and commonalities with respect to market penetration and market development have been defined in an online Delphi survey with 120 respondents. The results are based on a quantitative and qualitative survey and exchange between established companies and start-ups can add value for both company types. Established com-panies can learn from start-ups to be more innovative, flexible and fast. Start-ups can benefit from the long-standing experiences and relationships of the established companies. A combination of both strengths can help to overcome challenges and offset the weaknesses of the respective other. The best of both worlds means to try something new and preserve the existing, to seize new opportunities and avoid risks or to decide rationally without suppressing the entrepreneurial intuition

    Semaphorin-3D and semaphorin-3E inhibit the development of tumors from glioblastoma cells implanted in the cortex of the brain.

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    Class-3 semaphorins are secreted axon guidance factors. Some of these semaphorins have recently been characterized as suppressors of tumor progression. To determine if class-3 semaphorins can be used to inhibit the development of glioblastoma-multiforme tumors, we expressed recombinant sema-3A, 3B, 3D, 3E, 3F or 3G in U87MG glioblastoma cells. Sema3A and sema3B expressing cells contracted and changed shape persistently while cells expressing other semaphorins did not. Sema3A and sema3F differed from other semaphorins including sema3B as they also inhibited the proliferation of the cells and the formation of soft agar colonies. With the exception of sema3G and sema3B, expression of these semaphorins in U87MG cells inhibited significantly tumor development from subcutaneously implanted cells. Strong inhibition of tumor development was also observed following implantation of U87MG cells expressing each of the class-3 semaphorins in the cortex of mouse brains. Sema3D and sema3E displayed the strongest inhibitory effects and their expression in U373MG or in U87MG glioblastoma cells implanted in the brains of mice prolonged the survival of the mice by more then two folds. Furthermore, most of the mice that died prior to the end of the experiment did not develop detectable tumors and many of the mice survived to the end of the experiment. Most of the semaphorins that we have used here with the exception of sema3D were characterized previously as inhibitors of angiogenesis. Our results indicate that sema3D also functions as an inhibitor of angiogenesis and suggest that the anti-tumorigenic effects are due primarily to inhibition of tumor angiogenesis. These results indicate that class-3 semaphorins such as sema3D and sema3E could perhaps be used to treat glioblastoma patients

    Ligands of the Mitochondrial 18 kDa Translocator Protein Attenuate Apoptosis of Human Glioblastoma Cells Exposed to Erucylphosphohomocholine

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    Background: We have previously shown that the anti-neoplastic agent erucylphosphohomocholine (ErPC3) requires the mitochondrial 18 kDa Translocator protein (TSPO), formerly known as the peripheral-type benzodiazepine receptor (PBR), to induce cell death via the mitochondrial apoptosis pathway
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