The aim of the present study was to explore the transcriptome of pancreatic islets and, based on this information, to prepare a comprehensive and open access inventory of insulin-producing -cell gene expression, the beta-Cell Gene Atlas (BCGA).
Detailed transcriptome atlas of the pancreatic beta cell.
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View SamplesPancreatic islet transplantation as a cure for type 1 diabetes (T1D) cannot be scaled up due to a scarcity of human pancreas donors. In vitro expansion of beta cells from mature human pancreatic islets provides an alternative source of insulin-producing cells. The exact nature of the expanded cells produced by diverse expansion protocols, and their potential for differentiation into functional beta cells, remain elusive. We performed a large-scale meta-analysis of gene expression in human pancreatic islet cells, which were processed using three different previously described protocols for expansion and attempted re-differentiation. All three expansion protocols induced dramatic changes in the expression profiles of pancreatic islets; many of these changes are shared among the three protocols. Attempts at re-differentiation of expanded cells induce a limited number of gene expression changes. Nevertheless, these fail to restore a pancreatic islet-like gene expression pattern. Comparison with a collection of public microarray datasets confirmed that expanded cells are highly comparable to mesenchymal stem cells. Genes induced in expanded cells are also enriched for targets of transcription factors important for pluripotency induction. The present data increases our understanding of the active pathways in expanded and re-differentiated islets. Knowledge of the mesenchymal stem cell potential may help development of drug therapeutics to restore beta cell mass in T1D patients.
Meta-analysis of gene expression in human pancreatic islets after in vitro expansion.
Specimen part
View SamplesIn the context of T1 Diabetes, pro-inflammatory cytokines IL-1 and IFN- are known to contribute to -cell apoptosis;
Temporal profiling of cytokine-induced genes in pancreatic β-cells by meta-analysis and network inference.
Specimen part, Treatment, Time
View SamplesIn the context of T1 Diabetes, pro-inflammatory cytokines IL-1 and IFN- are known to contribute to -cell apoptosis;
Temporal profiling of cytokine-induced genes in pancreatic β-cells by meta-analysis and network inference.
Cell line, Treatment, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Evolutionary etiology of high-grade astrocytomas.
Sex, Time
View SamplesTo determine the regulatory pathways necessary for astrocytoma formation within complex adult brain microenvironments, we engineered mice for adult astrocyte-specific disruption of key regulators (pRb, Kras and Pten). Drivers of all astrocytoma grades were identified using CreERTM-inducible alleles. Inactivation of pRb was necessary to initiate grade II disease, and was the only lesion to do so. Additional activation of Kras progressed disease to grade III, while further Pten inactivation facilitated grade IV (glioblastoma) progression. These outcomes were elicited whether somatic events were induced broadly or focally. In vivo inactivation of pRb, which induced astrocyte proliferation and apoptosis, activated the MAPK pathway, while Kras activation and Pten loss triggered PI3K pathways.
Evolutionary etiology of high-grade astrocytomas.
Sex, Time
View SamplesNon-coding RNAs regulate many biological processes including neurogenesis. The brain-enriched miR-124 is assigned as a key player of neuronal differentiation via its complex, but little understood, regulation of thousands of annotated targets. To systematically chart its regulatory functions, we used CRISPR/Cas9 gene editing to disrupt all six miR-124 alleles in human stem cells. Upon neuronal induction, miR-124-depleted cells underwent neurogenesis and became functional neurons, albeit with altered morphology and neurotransmitter specification. By RNA-induced-silencing-complex precipitation, we found that other miRNA species were upregulated in miR-124 depleted neurons. Furthermore, we identified 98 miR-124 targets of which some directly led to decreased viability. We performed advanced transcription-factor-network analysis and revealed indirect miR-124 effects on apoptosis and neuronal subtype differentiation. Our data emphasizes the need for combined experimental- and systems-level analyses to comprehensively disentangle and reveal miRNA functions, including their involvement in the neurogenesis of diverse neuronal cell types found in the human brain. Overall design: RNA profile for timecourse of neuronal Neurogenin-1 and 2-triggered differentiation from human iPSCs (wildtype and ?miR-124).
Combined Experimental and System-Level Analyses Reveal the Complex Regulatory Network of miR-124 during Human Neurogenesis.
Subject
View SamplesNon-coding RNAs regulate many biological processes including neurogenesis. The brain-enriched miR-124 is assigned as a key player of neuronal differentiation via its complex, but little understood, regulation of thousands of annotated targets. To systematically chart its regulatory functions, we used CRISPR/Cas9 gene editing to disrupt all six miR-124 alleles in human stem cells. Upon neuronal induction, miR-124-depleted cells underwent neurogenesis and became functional neurons, albeit with altered morphology and neurotransmitter specification. By RNA-induced-silencing-complex precipitation, we found that other miRNA species were upregulated in miR-124 depleted neurons. Furthermore, we identified 98 miR-124 targets of which some directly led to decreased viability. We performed advanced transcription-factor-network analysis and revealed indirect miR-124 effects on apoptosis and neuronal subtype differentiation. Our data emphasizes the need for combined experimental- and systems-level analyses to comprehensively disentangle and reveal miRNA functions, including their involvement in the neurogenesis of diverse neuronal cell types found in the human brain. Overall design: RNA interacting protein immunoprecipitation with AGO2 for miR-124 target enrichment from neuronal Neurogenin-1 and 2-triggered differentiation from human iPSCs (wildtype and ?miR-124) and subsequent sequencing.
Combined Experimental and System-Level Analyses Reveal the Complex Regulatory Network of miR-124 during Human Neurogenesis.
Subject
View SamplesThe Ca2+/calmodulin-dependent kinase II is expressed in smooth muscle and believed to mediate intracellular calcium handling and calcium-dependent gene transcription. CaMKII is activated by Angiotensin-II.
Calcium/calmodulin-dependent kinase II inhibition in smooth muscle reduces angiotensin II-induced hypertension by controlling aortic remodeling and baroreceptor function.
Specimen part, Treatment
View SamplesMitochondrial calcium is an important second-messenger controlling fight-or-flight responses in the heart. The molecular identity of MCU (Mitochondrial Calcium Uniporter) was recently discovered allowing us to test this hypothesis in vivo by expressiing a myocardial delimited dominant negative form of MCU.
Inhibition of MCU forces extramitochondrial adaptations governing physiological and pathological stress responses in heart.
Sex, Age, Specimen part
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