Similar Datasets
Project description:Type 1 diabetes (T1D) is a prototypic T cell-mediated autoimmune disease. Because the islets of Langerhans are insulated from blood vessels by a double basement membrane and lack detectable lymphatic drainage, interactions between endocrine and circulating T cells are not permitted. Thus, we hypothesized that initiation and progression of anti-islet immunity required islet neolymphangiogenesis to allow T cell access to the islet. Combining microscopy and single cell approaches, the timing of this phenomenon in mice was situated between 5 and 8 wk of age when activated anti-insulin CD4 T cells became detectable in peripheral blood while peri-islet pathology developed. This "peri-insulitis," dominated by CD4 T cells, respected the islet basement membrane and was limited on the outside by lymphatic endothelial cells that gave it the attributes of a tertiary lymphoid structure. As in most tissues, lymphangiogenesis seemed to be secondary to local segmental endothelial inflammation at the collecting postcapillary venule. In addition to classic markers of inflammation such as CD29, V-CAM, and NOS, MHC class II molecules were expressed by nonhematopoietic cells in the same location both in mouse and human islets. This CD45- MHC class II+ cell population was capable of spontaneously presenting islet Ags to CD4 T cells. Altogether, these observations favor an alternative model for the initiation of T1D, outside of the islet, in which a vascular-associated cell appears to be an important MHC class II-expressing and -presenting cell.
| S-EPMC10944819 | biostudies-literature
Project description:LCM-coupled nanoPOTS proteomics using FAIMS of intra-islet microstructures. 5 acinar samples, 5 whole islets, 5 islet interface vasculature pools, 5 islet inner microvasculature pools, 3 islets after microsvasculature removed.
2022-01-25 | MSV000088730 | MassIVE
Project description:Using intravital 2-photon islet imaging we show that T cell extravasation into the islets is an extended process, with T cells arresting in the islet vasculature in close proximity to perivascular CD11c+ cells. Antigen is not required for T cell trafficking to infiltrated islets, but T cell chemokine receptor signaling is necessary. Using RNAseq, we show that islet CD11c+ cells express over 20 different chemokines that bind chemokine receptors expressed on islet T cells.
2019-03-01 | GSE121804 | GEO
Project description:Dysregulation of glucagon secretion in type 1 diabetes (T1D) involves hypersecretion during postprandial states, but insufficient secretion during hypoglycemia. The sympathetic nervous system regulates glucagon secretion. To investigate islet sympathetic innervation in T1D, sympathetic tyrosine hydroxylase (TH) axons were analyzed in control non-diabetic organ donors, non-diabetic islet autoantibody-positive individuals (AAb), and age-matched persons with T1D. Islet TH axon numbers and density were significantly decreased in AAb compared to T1D with no significant differences observed in exocrine TH axon volume or lengths between groups. TH axons were in close approximation to islet α-cells in T1D individuals with long-standing diabetes. Islet RNA-sequencing and qRT-PCR analyses identified significant alterations in noradrenalin degradation, α-adrenergic signaling, cardiac b-adrenergic signaling, catecholamine biosynthesis, and additional neuropathology pathways. The close approximation of TH axons at islet α-cells supports a model for sympathetic efferent neurons directly regulating glucagon secretion. Sympathetic islet innervation and intrinsic adrenergic signaling pathways could be novel targets for improving glucagon secretion in T1D.
2021-08-09 | GSE181674 | GEO
Project description:Single-cell atlas of the human brain vasculature across development, adulthood and disease (Extra Individuals)
| PRJNA1079775 | ENA
Project description:Pancreatic islets are essential for maintaining physiological blood glucose levels, and declining islet function is a hallmark of type 2 diabetes. Here we employ mass spectrometry (MS)-based proteomics to systematically analyse purified islets from 9 genetic or diet-induced mouse models representing a broad cross-section of metabolic health. Quantifying the islet proteome to a depth of >11,500 proteins, this study represents the most detailed analysis of islet proteins to date. Our data highlight that the vast majority of islet proteins are expressed in all strains and diets, but more than half of the proteins vary in expression levels. Associating these varied protein expression levels on an individual animal basis with individual phenotypic measures reveals islet mitochondrial function as a major positive indicator of metabolic health. This compendium of strain-specific and dietary changes to mouse islet proteomes represents a comprehensive resource for basic and translational islet cell biology.
2021-10-08 | PXD024522 | Pride
Project description:Identification of transcriptional profile of several genes involved in diabetes in islet-derived extracellular vesicles (Evs). Recently, EVs are identified as a new mechanism in cell-to-cell communication by transfer of protein and genic information (mRNA, microRNA). Their role is under investigation in immunology, stem cell and cancer, but not in islets and diabetes. The aim of this experiment is to identify mRNA transcripts (in particular, mRNA transcripts involved in diabetes pathophysiology) present in islet Evs.
2012-08-02 | E-MEXP-3695 | biostudies-arrayexpress
Project description:Islets in Type 2 diabetes (T2D) share many diverse abnormalities reported in neurodegenerative diseases, including the formation of toxic oligomers from amyloidogenic proteins. We evaluated the transcriptome of murine islets with beta cell-specific human IAPP (hIAPP) expression to assess the potential contribution of hIAPP toxicity to those observed in islets from T2D.Beta cell hIAPPtoxicity induced an islet transcriptome highly analogous to that in islets from humans with T2D with a prominent inflammatory signature, activation of vascular epithelium and stellate cells, cytoskeleton remodeling,and activation of cell-cycle andcellular dedifferentiation. In conclusion, many of the apparently widely disparate changes in islets in T2D may be initiated by toxic oligomers. Inhibition of expression of amyloidogenic proteins or proximal adverse consequences such as disruption of the cytoskeleton by calpain hyperactivation are rational targets for therapeutic intervention in T2D and neurodegenerative disease.
2021-10-21 | GSE148809 | GEO
Project description:A broad range of brain pathologies critically relies on the vasculature, and cerebrovascular disease is a leading cause of death worldwide. However, the cellular and molecular architecture of the human brain vasculature remains incompletely understood. Here, we performed single-cell RNA sequencing of 606,380 freshly isolated endothelial, perivascular and other tissue-derived cells from 117 samples, from 68 human fetuses and adult patients to construct a molecular atlas of the developing fetal, adult control and diseased human brain vasculature. We uncover extensive molecular heterogeneity of the vasculature of healthy fetal and adult human brains and across eight vascular-dependent Central Nervous System (CNS) pathologies including brain tumors and brain vascular malformations. We identify alteration of arteriovenous differentiation and reactivated fetal as well as conserved dysregulated genes and pathways in the diseased vasculature. Pathological endothelial cells display a loss of CNS-specific properties and reveal an upregulation of MHC class II molecules, indicating atypical features of CNS endothelial cells. Cell-cell interaction analyses predict numerous endothelial-to-perivascular cell ligand-receptor crosstalk including immune-related and angiogenic pathways, thereby unraveling a central role for the endothelium within brain neurovascular unit signaling networks. Our single-cell brain atlas provides insight into the molecular architecture and heterogeneity of the developing, adult/control and diseased human brain vasculature and serves as a powerful reference for future studies
2024-02-29 | GSE256491 | GEO
Project description:Blood vessels play a critical role in pancreatic islet health and function, yet current culture methods to generate islet organoids from human pluripotent stem cells (SC-islets) lack a vascular component. Here, we engineered 3D vascularized SC-islet organoids by assembling SC-islet cells, human primary endothelial cells (ECs) and fibroblasts both in a non-perfused model and a microfluidic device with perfused vessels. Vasculature improved stimulus-dependent Ca2+ influx into SC-β-cells; a hallmark of β-cell function that is blunted in non-vascularized SC-islets. We show that an islet-like basement membrane is formed by vasculature and contributes to the functional improvement of SC-β-cells. Furthermore, cell-cell communication networks based on scRNA-seq data predicted BMP2/4-BMPR2 signaling from ECs to SC-β-cells. Correspondingly, BMP4 augmented the SC-β-cell Ca2+ response and insulin secretion. The here-described vascularized SC-islet models will enable further studies of crosstalk between β-cells and ECs and serve as an in vivo-mimicking platform for disease modeling and therapeutic testing.
2023-05-01 | GSE215376 | GEO