Gut hormones control intestinal function, metabolism and appetite, and have been harnessed therapeutically to treat type 2 diabetes and obesity. Our understanding of the enteroendocrine axis arises largely from animal studies, but intestinal organoid models make it possible to identify, genetically modify and purify human enteroendocrine cells (EECs). This study aimed to map human EECs using single-cell RNA sequencing.
View Article and Find Full Text PDFAims/hypothesis: Glucose-dependent insulinotropic polypeptide (GIP) is an incretin hormone secreted by enteroendocrine K cells in the proximal small intestine. This study aimed to explore the function of human K cells at the molecular and cellular levels.
Methods: CRISPR-Cas9 homology-directed repair was used to insert transgenes encoding a yellow fluorescent protein (Venus) or an Epac-based cAMP sensor (Epac-S-H187) in the GIP locus in human duodenal-derived organoids.
Adaptation of photoreceptor sensitivity to varying light intensities is a fundamental requirement for retinal function and vision. Adaptive mechanisms in signal transduction are well described, but little is known about the mechanisms that adapt the photoreceptor synapse to changing light intensities. The SNARE complex regulators Complexin 3 and Complexin 4 have been proposed to be involved in synaptic light adaptation by limiting synaptic vesicle recruitment and fusion.
View Article and Find Full Text PDFFront Cell Neurosci
November 2022
Mammalian cone photoreceptors enable through their sophisticated synapse the high-fidelity transfer of visual information to second-order neurons in the retina. The synapse contains a proteinaceous organelle, called the synaptic ribbon, which tethers synaptic vesicles (SVs) at the active zone (AZ) close to voltage-gated Ca channels. However, the exact contribution of the synaptic ribbon to neurotransmission is not fully understood, yet.
View Article and Find Full Text PDFIt is a commonly accepted view that light stimulation of mammalian photoreceptors causes a graded change in membrane potential instead of developing a spike. The presynaptic Ca channels serve as a crucial link for the coding of membrane potential variations into neurotransmitter release. Ca1.
View Article and Find Full Text PDFAutofluorescence (AF) is an intrinsic characteristic of cells caused by the presence of fluorescent biological compounds within the cell; these can include structural proteins (e.g., collagen and elastin), cellular organelles, and metabolites (e.
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
March 2022
Purpose: Cone photoreceptors of the retina use a sophisticated ribbon-containing synapse to convert light-dependent changes in membrane potential into release of synaptic vesicles (SVs). We aimed to study the functional and structural maturation of mouse cone photoreceptor ribbon synapses during postnatal development and to investigate the role of the synaptic ribbon in SV release.
Methods: We performed patch-clamp recordings from cone photoreceptors and their postsynaptic partners, the horizontal cells during postnatal retinal development to reveal the functional parameters of the synapses.
Unlabelled: Circulating endothelial progenitor cells (EPCs) contribute to vascular healing and neovascularisation, while exercise is an effective means to mobilise EPCs into the circulation.
Objectives: to systematically examine the acute and chronic effects of different forms of exercise on circulating EPCs in healthy populations.
Methods: Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed.
Unlabelled: Circulating endothelial progenitor cells (EPCs) contribute to vascular repair and their monitoring could have prognostic clinical value. Exercise is often prescribed for the management of cardiometabolic diseases, however, it is not fully understood how it regulates EPCs.
Objectives: to systematically examine the acute and chronic effects of different exercise modalities on circulating EPCs in patients with cardiovascular and metabolic disease.
Objectives: Murine models of interleukin (IL)-23-driven spondyloarthritis (SpA) have demonstrated entheseal accumulation of γδT-cells which were responsible for the majority of local IL-17A production. However, IL-23 blockers are ineffective in axial inflammation in man. This study investigated γδT-cell subsets in the normal human enthesis to explore the biology of the IL-23/17 axis.
View Article and Find Full Text PDFBackground: CNS tumors, including medulloblastoma and pediatric glioblastoma (pGBM) account for the majority of solid pediatric malignancies. There remains an unmet need to identify novel treatment approaches in poor prognosis and relapsed pediatric brain tumors, where therapeutic options are limited. Small-molecule B-cell lymphoma 2 (BCL-2) family inhibitors may enhance tumor cell killing when combined with conventional and targeted chemotherapeutic agents.
View Article and Find Full Text PDFHuman B cells with immunoregulatory properties in vitro (Bregs) have been defined by the expression of IL-10 and are enriched in various B-cell subsets. However, proinflammatory cytokine expression in B-cell subsets is largely unexplored. We examined the cytokine profiles of human PBMCs and found that subsets of CD24(hi)CD38(hi) transitional B cells (TrBs), CD24(hi)CD27(+) memory B cells, and naïve B cells express IL-10 and the proinflammatory cytokine TNF-α simultaneously.
View Article and Find Full Text PDFPlasma cells (PCs), the terminal effectors of humoral immunity, are short-lived unless supported by niche environments in which they may persist for years. No model system has linked B cell activation with niche function to allow the in vitro generation of long-lived PCs. Thus, the full trajectory of B cell terminal differentiation has yet to be investigated in vitro.
View Article and Find Full Text PDFNK cell activation is negatively regulated by the expression of target cell MHC class I molecules. We show that this relationship is nonlinear due to an NK cell activation/inhibition threshold. Ewing's sarcoma family tumor cell monolayers, which were highly susceptible to NK cells in vitro, developed a highly resistant phenotype when cultured as three-dimensional multicellular tumor spheroid structures.
View Article and Find Full Text PDFCytotoxic lymphocytes eliminate infected cells and tumours via the perforin-mediated delivery of pro-apoptotic serine proteases known as granzymes. Granzyme B triggers apoptosis via the cleavage of a repertoire of cellular proteins, leading to caspase activation and mitochondrial depolarization. A simple bioinformatics strategy identified a candidate granzyme B cleavage site in the widely expressed BNIP-2 (BCL2/adenovirus E1B-19K protein-interacting protein 2).
View Article and Find Full Text PDFIt is widely considered that, for Higgs boson searches at the CERN Large Hadron Colider, WH and ZH production where the Higgs boson decays to bb are poor search channels due to large backgrounds. We show that at high transverse momenta, employing state-of-the-art jet reconstruction and decomposition techniques, these processes can be recovered as promising search channels for the standard model Higgs boson around 120 GeV in mass.
View Article and Find Full Text PDFBackground: Stanley Milgram's 1960s experimental findings that people would administer apparently lethal electric shocks to a stranger at the behest of an authority figure remain critical for understanding obedience. Yet, due to the ethical controversy that his experiments ignited, it is nowadays impossible to carry out direct experimental studies in this area. In the study reported in this paper, we have used a similar paradigm to the one used by Milgram within an immersive virtual environment.
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