45 research outputs found
Biochemical and transcriptomic evaluation of a 3D lung organoid platform for pre-clinical testing of active substances targeting senescence
Chronic lung diseases such as chronic obstructive pulmonary disease and cystic fibrosis are incurable. Epithelial
senescence, a state of dysfunctional cell cycle arrest, contributes to the progression of such diseases. Therefore,
lung epithelial cells are a valuable target for therapeutic intervention. Here, we present a 3D airway lung organoid
platform for the preclinical testing of active substances with regard to senescence, toxicity, and inflammation under
standardized conditions in a 96 well format. Senescence was induced with doxorubicin and measured by activity
of senescence associated galactosidase. Pharmaceutical compounds such as quercetin antagonized doxorubicininduced senescence without compromising organoid integrity. Using single cell sequencing, we identified a subset
of cells expressing senescence markers which was decreased by quercetin. Doxorubicin induced the expression of
detoxification factors specifically in goblet cells independent of quercetin. In conclusion, our platform enables for
the analysis of senescence-related processes and will allow the pre-selection of a wide range of compounds (e.g.
natural products) in preclinical studies, thus reducing the need for animal testing
Daytime Naps, Motor Memory Consolidation and Regionally Specific Sleep Spindles
BACKGROUND: Increasing evidence demonstrates that motor-skill memories improve across a night of sleep, and that non-rapid eye movement (NREM) sleep commonly plays a role in orchestrating these consolidation enhancements. Here we show the benefit of a daytime nap on motor memory consolidation and its relationship not simply with global sleep-stage measures, but unique characteristics of sleep spindles at regionally specific locations; mapping to the corresponding memory representation. METHODOLOGY/PRINCIPAL FINDINGS: Two groups of subjects trained on a motor-skill task using their left hand – a paradigm known to result in overnight plastic changes in the contralateral, right motor cortex. Both groups trained in the morning and were tested 8 hr later, with one group obtaining a 60–90 minute intervening midday nap, while the other group remained awake. At testing, subjects that did not nap showed no significant performance improvement, yet those that did nap expressed a highly significant consolidation enhancement. Within the nap group, the amount of offline improvement showed a significant correlation with the global measure of stage-2 NREM sleep. However, topographical sleep spindle analysis revealed more precise correlations. Specifically, when spindle activity at the central electrode of the non-learning hemisphere (left) was subtracted from that in the learning hemisphere (right), representing the homeostatic difference following learning, strong positive relationships with offline memory improvement emerged–correlations that were not evident for either hemisphere alone. CONCLUSIONS/SIGNIFICANCE: These results demonstrate that motor memories are dynamically facilitated across daytime naps, enhancements that are uniquely associated with electrophysiological events expressed at local, anatomically discrete locations of the brain
Technologies of sleep research
Sleep is investigated in many different ways, many different species and under many different circumstances. Modern sleep research is a multidisciplinary venture. Therefore, this review cannot give a complete overview of all techniques used in sleep research and sleep medicine. What it will try to do is to give an overview of widely applied techniques and exciting new developments. Electroencephalography has been the backbone of sleep research and sleep medicine since its first application in the 1930s. The electroencephalogram is still used but now combined with many different techniques monitoring body and brain temperature, changes in brain and blood chemistry, or changes in brain functioning. Animal research has been very important for progress in sleep research and sleep medicine. It provides opportunities to investigate the sleeping brain in ways not possible in healthy volunteers. Progress in genomics has brought new insights in sleep regulation, the best example being the discovery of hypocretin/orexin deficiency as the cause of narcolepsy. Gene manipulation holds great promise for the future since it is possible not only to investigate the functions of different genes under normal conditions, but also to mimic human pathology in much greater detail
Prediction of single-cell gene expression for transcription factor analysis
BACKGROUND: Single-cell RNA sequencing is a powerful technology to discover new cell types and study biological processes in complex biological samples. A current challenge is to predict transcription factor (TF) regulation from single-cell RNA data. RESULTS: Here, we propose a novel approach for predicting gene expression at the single-cell level using cis-regulatory motifs, as well as epigenetic features. We designed a tree-guided multi-task learning framework that considers each cell as a task. Through this framework we were able to explain the single-cell gene expression values using either TF binding affinities or TF ChIP-seq data measured at specific genomic regions. TFs identified using these models could be validated by the literature. CONCLUSION: Our proposed method allows us to identify distinct TFs that show cell type–specific regulation. This approach is not limited to TFs but can use any type of data that can potentially be used in explaining gene expression at the single-cell level to study factors that drive differentiation or show abnormal regulation in disease. The implementation of our workflow can be accessed under an MIT license via https://github.com/SchulzLab/Triangulate