38 research outputs found
MicroRNA-100-5p and microRNA-298-5p released from apoptotic cortical neurons are endogenous Toll-like receptor 7/8 ligands that contribute to neurodegeneration
Background: MicroRNA (miRNA) expression in the brain is altered in neurodegenerative diseases. Recent studies demonstrated that selected miRNAs conventionally regulating gene expression at the post-transcriptional level can act extracellularly as signaling molecules. The identity of miRNA species serving as membrane receptor ligands involved in neuronal apoptosis in the central nervous system (CNS), as well as the miRNAs' sequence and structure required for this mode of action remained largely unresolved.
Methods. Using a microarray-based screening approach we analyzed apoptotic cortical neurons of C56BL/6 mice and their supernatant with respect to alterations in miRNA expression/presence. HEK-Blue Toll-like receptor (TLR) 7/8 reporter cells, primary microglia and macrophages derived from human and mouse were employed to test the potential of the identified miRNAs released from apoptotic neurons to serve as signaling molecules for the RNA-sensing receptors. Biophysical and bioinformatical approaches, as well as immunoassays and sequential microscopy were used to analyze the interaction between candidate miRNA and TLR. Immunocytochemical and -histochemical analyses of murine CNS cultures and adult mice intrathecally injected with miRNAs, respectively, were performed to evaluate the impact of miRNA-induced TLR activation on neuronal survival and microglial activation.
Results: We identified a specific pattern of miRNAs released from apoptotic cortical neurons that activate TLR7 and/or TLR8, depending on sequence and species. Exposure of microglia and macrophages to certain miRNA classes released from apoptotic neurons resulted in the sequence-specific production of distinct cytokines/chemokines and increased phagocytic activity. Out of those miRNAs miR-100-5p and miR-298-5p, which have consistently been linked to neurodegenerative diseases, entered microglia, located to their endosomes, and directly bound to human TLR8. The miRNA-TLR interaction required novel sequence features, but no specific structure formation of mature miRNA. As a consequence of miR-100-5p- and miR-298-5p-induced TLR activation, cortical neurons underwent cell-autonomous apoptosis. Presence of miR-100-5p and miR-298-5p in cerebrospinal fluid led to neurodegeneration and microglial accumulation in the murine cerebral cortex through TLR7 signaling.
Conclusion: Our data demonstrate that specific miRNAs are released from apoptotic cortical neurons, serve as endogenous TLR7/8 ligands, and thereby trigger further neuronal apoptosis in the CNS. Our findings underline the recently discovered role of miRNAs as extracellular signaling molecules, particularly in the context of neurodegeneration
Self-efficacy in relation to the use of complementary and alternative medicine, lifestyle choices and cancer aetiology
Purpose!#!This survey assesses cancer patients' etiological concepts, lifestyle choices, use of complementary and alternative medicine (CAM), and self-efficacy, as well as associations between those. It aims to find patterns which may facilitate communication and understanding between patients and physicians.!##!Methods!#!353 oncological patients attending lectures on CAM answered a questionnaire. Correlations were examined and an exploratory factor analysis conducted to identify comprehensive lay-etiological concepts among a list of potential carcinogenic factors.!##!Results!#!Patients considered scientifically proven agents as well as other non-carcinogenic influences to be responsible for their disease. An exploratory factor analysis yielded vague indications of possible underlying concepts but factors tend to include items that do not fit the pattern in terms of content. Higher self-efficacy correlated with healthy diet and sports, but not with use of CAM. No conclusive correlations emerged between lay-aetiological concepts and most other variables, but we found a tendency for higher self-efficacy among patients who assigned higher carcinogenic effects to tobacco and lower carcinogenic effects to fasting and physical trauma.!##!Conclusion!#!Interest in CAM can arise for many reasons that are not necessarily related to self-efficacy. Lay-aetiological concepts of cancer differ significantly from scientific ones. They are complex and presumably highly individualistic. Their connection to use of CAM methods, lifestyle choices and self-efficacy should be explored in more detail. Patient information and communication with clinicians need to address cancer patients' individual aetiological concepts to further patient's understanding not only of their diagnosis but also of the treatment as well
Collaborative real-time motion video analysis by human observer and image exploitation algorithms
Motion video analysis is a challenging task, especially in real-time applications. In most safety and security critical applications, a human observer is an obligatory part of the overall analysis system. Over the last years, substantial progress has been made in the development of automated image exploitation algorithms. Hence, we investigate how the benefits of automated video analysis can be integrated suitably into the current video exploitation systems. In this paper, a system design is introduced which strives to combine both the qualities of the human observer's perception and the automated algorithms, thus aiming to improve the overall performance of a real-time video analysis system. The system design builds on prior work where we showed the benefits for the human observer by means of a user interface which utilizes the human visual focus of attention revealed by the eye gaze direction for interaction with the image exploitation system; eye tracker-based interaction allows much faster, more convenient, and equally precise moving target acquisition in video images than traditional computer mouse selection. The system design also builds on prior work we did on automated target detection, segmentation, and tracking algorithms. Beside the system design, a first pilot study is presented, where we investigated how the participants (all non-experts in video analysis) performed in initializing an object tracking subsystem by selecting a target for tracking. Preliminary results show that the gaze + key press technique is an effective, efficient, and easy to use interaction technique when performing selection operations on moving targets in videos in order to initialize an object tracking function
Pilot study on real-time motion detection in UAS video data by human observer and image exploitation algorithm
Real-time motion video analysis is a challenging and exhausting task for the human observer, particularly in safety and security critical domains. Hence, customized video analysis systems providing functions for the analysis of subtasks like motion detection or target tracking are welcome. While such automated algorithms relieve the human operators from performing basic subtasks, they impose additional interaction duties on them. Prior work shows that, e.g., for interaction with target tracking algorithms, a gaze-enhanced user interface is beneficial. In this contribution, we present an investigation on interaction with an independent motion detection (IDM) algorithm. Besides identifying an appropriate interaction technique for the user interface – again, we compare gaze-based and traditional mouse-based interaction – we focus on the benefit an IDM algorithm might provide for an UAS video analyst. In a pilot study, we exposed ten subjects to the task of moving target detection in UAS video data twice, once performing with automatic support, once performing without it. We compare the two conditions considering performance in terms of effectiveness (correct target selections). Additionally, we report perceived workload (measured using the NASA-TLX questionnaire) and user satisfaction (measured using the ISO 9241-411 questionnaire). The results show that a combination of gaze input and automated IDM algorithm provides valuable support for the human observer, increasing the number of correct target selections up to 62% and reducing workload at the same time
Abnormal brain structure and behavior in MyD88-deficient mice.
While the original protein Toll in Drosophila melanogaster regulates both host defense and morphogenesis, the role of its ortholog Toll-like receptors (TLRs), the interleukin 1 receptor (IL-1R) family, and the associated signaling pathways in mammalian brain development and structure is poorly understood. Because the adaptor protein myeloid differentiation primary response protein 88 (MyD88) is essential for downstream signaling of most TLRs and IL-1R, we systematically investigated the effect of MyD88 deficiency on murine brain structure during development and on behavior. In neonatal Myd88 mice, neocortical thickness was reduced, while density of cortical neurons was increased. In contrast, microglia, astrocyte, oligodendrocyte, and proliferating cell numbers were unchanged in these mice compared to wild-type mice. In adult Myd88 mice, neocortical thickness was unaltered, but neuronal density in neocortex and hippocampus was increased. Neuron arborization was less pronounced in adult Myd88 mice compared to wild-type animals. In addition, numbers of microglia and proliferating cells were increased in the neocortex and subventricular zone, respectively, with unaltered astrocyte and oligodendrocyte numbers, and myelinization was enhanced in the adult Myd88 neocortex. These morphologic changes in the brain of adult Myd88 mice were accompanied by specific behavioral traits, such as decreased locomotor activity, increased anxiety-like behavior, but normal day/light activity, satisfactory learning, short- and long-term spatial memory, potential cognitive inflexibility, and increased hanging and locomotor behavior within their home cage. Taken together, MyD88 deficiency results in morphologic and cellular changes in the mouse brain, as well as in altered natural and specific behaviors. Our data indicate a pathophysiological significance of MyD88 for mammalian CNS development, structure, and function.This work was supported by Deutsche Forschungsgemeinschaft (DFG) LE 2420/2-1, SFB-TRR167/B03, NeuroCure Exc 257 (to S.L.), SFB-1315, FOR 3004 (to A.M.K.), and by Charité – Universitätsmedizin Berlin
Immunomodulating Effect of the Consumption of Watercress (Nasturtium officinale) on Exercise-Induced Inflammation in Humans
The vegetable watercress (Nasturtium officinale R.Br.) is, besides being a generally nutritious food, a rich source of glucosinolates. Gluconasturtiin, the predominant glucosinolate in watercress, has been shown to have several health beneficial properties through its bioactive breakdown product phenethyl isothiocyanate. Little is known about the immunoregulatory effects of watercress. Moreover, anti-inflammatory effects have mostly been shown in in vitro or in animal models. Hence, we conducted a proof-of-concept study to investigate the effects of watercress on the human immune system. In a cross-over intervention study, 19 healthy subjects (26.5 ± 4.3 years; 14 males, 5 females) were given a single dose (85 g) of fresh self-grown watercress or a control meal. Two hours later, a 30 min high-intensity workout was conducted to promote exercise-induced inflammation. Blood samples were drawn before, 5 min after, and 3 h after the exercise unit. Inflammatory blood markers (IL-1β, IL-6, IL-10, TNF-α, MCP-1, MMP-9) were analyzed in whole blood cultures after ex vivo immune cell stimulation via lipopolysaccharides. A mild pro-inflammatory reaction was observed after watercress consumption indicated by an increase in IL-1β, IL-6, and TNF-α, whereas the immune response was more pronounced for both pro-inflammatory and anti-inflammatory markers (IL-1β, IL-6, IL-10, TNF-α) after the exercise unit compared to the control meal. During the recovery phase, watercress consumption led to a stronger anti-inflammatory downregulation of the pro-inflammatory cytokines IL-6 and TNF-α. In conclusion, we propose that watercress causes a stronger pro-inflammatory response and anti-inflammatory counter-regulation during and after exercise. The clinical relevance of these changes should be verified in future studies
Epstein-Barr Virus-Induced Genes and Endogenous Retroviruses in Immortalized B Cells from Patients with Multiple Sclerosis
The immune pathogenesis of multiple sclerosis (MS) is thought to be triggered by environmental factors in individuals with an unfavorable genetic predisposition. Epstein–Barr virus (EBV) infection is a major risk factor for subsequent development of MS. Human endogenous retroviruses (HERVs) can be activated by EBV, and might be a missing link between an initial EBV infection and the later onset of MS. In this study, we investigated differential gene expression patterns in EBV-immortalized lymphoblastoid B cell lines (LCL) from MS-affected individuals (MSLCL) and controls by using RNAseq and qRT-PCR. RNAseq data from LCL mapped to the human genome and a virtual virus metagenome were used to identify possible biomarkers for MS or disease-relevant risk factors, e.g., the relapse rate. We observed that lytic EBNA-1 transcripts seemed to be negatively correlated with age leading to an increased expression in LCL from younger PBMC donors. Further, HERV-K (HML-2) GAG was increased upon EBV-triggered immortalization. Besides the well-known transactivation of HERV-K18, our results suggest that another six HERV loci are up-regulated upon stimulation with EBV. We identified differentially expressed genes in MSLCL, e.g., several HERV-K loci, ERVMER61-1 and ERV3-1, as well as genes associated with relapses. In summary, EBV induces genes and HERV in LCL that might be suitable as biomarkers for MS or the relapse risk