Reduced basal insulin secretion from islets isolated from tafazzin deficient mice is associated with reduced mitochondrial function
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA561720 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR10015379_1.fastq.gz | Fastqsanger.gz | |||
| SRR10015379_2.fastq.gz | Fastqsanger.gz | |||
| SRR10015380_1.fastq.gz | Fastqsanger.gz | |||
| SRR10015380_2.fastq.gz | Fastqsanger.gz | |||
| SRR10015381_1.fastq.gz | Fastqsanger.gz |
Items per page: 5 1 - 5 of 8 |
Similar Datasets
Project description:Tafazzin is a transacylase which causes the content and molecular structure of cardiolipin (CL) to be altered in the inner mitochondrial membrane. The enzymatic machinery responsible for oxidative respiration are localized to the inner mitochondrial membrane and require CL for activity. As a result, tafazzin is critical for maintaining mitochondrial function. In beta-cells, which are the insulin secreting cells in pancreatic islets, mitochondrial function is linked to insulin secretion. We previously established that tafazzin knock-down mice were lean and maintained insulin sensitivity compared to the obese insulin resistant control litter mates. However, it was unknown whether tafazzin deficiency also influenced insulin secretion in the establishment of the lean phenotype. Using X week-old mice, we ascertained that the number of beta-cells was similar between genotypes. Ex vivo insulin secretion under low glucose conditions was reduced (52%) from islets isolated from tafazzin knock-down mice. Consistent with this tafazzin knock-down mice exhibited reduced fasting insulin plasma insulin levels. Measurement of mitochondrial oxygen consumption revealed that basal oxygen consumption was reduced (58%) in islets from tafazzin-deficient animals. The addition of etomoxir, an inhibitor of mitochondrial fatty acid translocation, significantly elevated basal mitochondrial respiration (5-fold) in islets from tafazzin knockdown mice, indicating a significant fatty acid-mediated inhibitory effect. In contrast, etomoxir lacked any measurable effect on control wild-type islets. The altered mitochondrial function identified in taffazin knock-down islets was not associated with reduced CL content or elevated oxyCL species. Our experiments indicate that tafazzin plays a key role in regulating normal islet beta-cell function.
2021-07-31 | GSE136242 | GEO
Project description:Tafazzin (TAZ) is a cardiolipin (CL) biosynthetic enzyme important for maintaining mitochondrial function. TAZ affects both the species and content of CL in the inner mitochondrial membrane, which are essential for normal cellular respiration. In pancreatic β cells, mitochondrial function is closely associated with insulin secretion. However, the role of TAZ and CL in the secretion of insulin from pancreatic islets remains unknown. Male 4-month-old doxycycline-inducible TAZ knock-down (KD) mice and wild-type littermate controls were used. Immunohistochemistry was used to assess β-cell morphology in whole pancreas sections, whereas ex vivo insulin secretion, CL content, RNA-sequencing analysis, and mitochondrial oxygen consumption were measured from isolated islet preparations. Ex vivo insulin secretion under nonstimulatory low-glucose concentrations was reduced ~52% from islets isolated from TAZ KD mice. Mitochondrial oxygen consumption under low-glucose conditions was also reduced ~58% in islets from TAZ KD animals. TAZ deficiency in pancreatic islets was associated with significant alteration in CL molecular species and elevated polyunsaturated fatty acid CL content. In addition, RNA-sequencing of isolated islets showed that TAZ KD increased expression of extracellular matrix genes, which are linked to pancreatic fibrosis, activated stellate cells, and impaired β-cell function. These data indicate a novel role for TAZ in regulating pancreatic islet function, particularly under low-glucose conditions.
| S-EPMC8197286 | biostudies-literature
Project description:Wolfram syndrome, an autosomal recessive disorder characterized by juvenile-onset diabetes mellitus and optic atrophy, is caused by mutations in the WFS1 gene. WFS1 encodes an endoplasmic reticulum resident transmembrane protein. The Wfs1-null mice exhibit progressive insulin deficiency and diabetes. The aim of the present study was to describe the insulin secretion and transcriptome of pancreatic islets in WFS1-deficient mice. WFS1-deficient (Wfs1KO) mice had considerably less pancreatic islets than heterozygous (Wfs1HZ) or wild-type (WT) mice. Wfs1KO pancreatic islets secreted less insulin after stimulation with 2 and 10 mM glucose and with tolbutamide solution compared to WT and Wfs1HZ islets, but not after stimulation with 20 mM glucose. Differences in proinsulin amount were not statistically significant although there was a trend that Wfs1KO had an increased level of proinsulin. After stimulation with 2 mM glucose solution the proinsulin/insulin ratio in Wfs1KO was significantly higher than that of WT and Wfs1HZ. RNA-seq from pancreatic islets found melastatin-related transient receptor potential subfamily member 5 protein gene (Trpm5) to be downregulated in WFS1-deficient mice. Functional annotation of RNA sequencing results showed that WFS1 deficiency influenced significantly the pathways related to tissue morphology, endocrine system development and function, molecular transport network. These findings suggest an interactive role of WFS1 and TRPM5 in insulin secretion. 12 samples: three genotypes, 4 individuals in each genotype
2015-02-14 | E-GEOD-65929 | biostudies-arrayexpress
Project description:The activity of pancreatic islets’ insulin-producing β-cells is closely regulated by systemic cues and, locally, by adjacent islet hormone-producing “non-β-cells” (namely α-, δ- and γ-cells). Still, it is unclear whether the presence of the non-β-cells is a requirement for accurate insulin secretion. Here, we generated and studied a mouse model in which adult islets are exclusively composed of β-cells, and human pseudoislets containing only primary β-cells. Mice lacking non-β-cells had optimal blood glucose regulation. They exhibited enhanced glucose tolerance, insulin sensitivity and restricted body weight gain under high-fat diet. The insulin secretion dynamics in islets composed of only β-cells was like in intact islets, both in homeostatic conditions and upon extreme insulin demand. Similarly, human β-cell pseudoislets retained the glucose-regulated mitochondrial respiration, insulin secretion and exendin-4 responses of human islets comprising all four cell types. Together, the findings indicate that non-β-cells are dispensable for blood glucose homeostasis and β-cell function. This is particularly relevant in diabetes, where non-β-cells become dysfunctional and worsen the disease’s pathophysiology. These results support efforts aimed at developing diabetes treatments by generating β-like cell clusters devoid of non-β-cells, as for example from human embryonic stem cells and/or by in situ conversion of non-β-cells into insulin producers.
2024-07-19 | GSE226479 | GEO
Project description:Wolfram syndrome, an autosomal recessive disorder characterized by juvenile-onset diabetes mellitus and optic atrophy, is caused by mutations in the WFS1 gene. WFS1 encodes an endoplasmic reticulum resident transmembrane protein. The Wfs1-null mice exhibit progressive insulin deficiency and diabetes. The aim of the present study was to describe the insulin secretion and transcriptome of pancreatic islets in WFS1-deficient mice. WFS1-deficient (Wfs1KO) mice had considerably less pancreatic islets than heterozygous (Wfs1HZ) or wild-type (WT) mice. Wfs1KO pancreatic islets secreted less insulin after stimulation with 2 and 10 mM glucose and with tolbutamide solution compared to WT and Wfs1HZ islets, but not after stimulation with 20 mM glucose. Differences in proinsulin amount were not statistically significant although there was a trend that Wfs1KO had an increased level of proinsulin. After stimulation with 2 mM glucose solution the proinsulin/insulin ratio in Wfs1KO was significantly higher than that of WT and Wfs1HZ. RNA-seq from pancreatic islets found melastatin-related transient receptor potential subfamily member 5 protein gene (Trpm5) to be downregulated in WFS1-deficient mice. Functional annotation of RNA sequencing results showed that WFS1 deficiency influenced significantly the pathways related to tissue morphology, endocrine system development and function, molecular transport network. These findings suggest an interactive role of WFS1 and TRPM5 in insulin secretion.
2015-02-14 | GSE65929 | GEO
Project description:Differential effects of voclosporin and tacrolimus on insulin secretion from human islets
| PRJNA659488 | ENA
Project description:After the discovery of insulin a century ago, extensive work has been done to unravel the molecular network regulating insulin secretion. Here, we performed a chemical screen and identified AZD7762, a compound that potentiates glucose-stimulated insulin secretion (GSIS) of human β cell line, healthy and type 2 diabetic (T2D) human islets, and primary cynomolgus macaque islets. In vivo studies in diabetic mouse models and cynomolgus macaques demonstrated that AZD7762 enhances GSIS and improves glucose tolerance. Furthermore, genetic manipulation confirmed that ablation of CHEK2 in human β cells results in increased insulin secretion. Consistently, high-fat-diet fed Chk2-/- mice show elevated insulin secretion and improved glucose clearance. Finally, an untargeted metabolic profiling demonstrated the key role of the CHEK2-PP2A-PLK1-G6PD-PPP pathway in insulin secretion. This study successfully identifies a previously unknown insulin secretion regulating pathway that is conserved across rodents, cynomolgus macaques and human β cells in both healthy and T2D conditions.
2023-10-25 | GSE239335 | GEO
Project description:Regulated and adaptive in vivo insulin secretion from islets only containing β-cells
| PRJNA940415 | ENA
Project description:Fine-tuning of insulin release from pancreatic β-cells is essential to maintain blood glucose homeostasis. Here, we report that insulin secretion is regulated by a circular RNA containing the lariat sequence of the second intron of the insulin gene. Silencing of this intronic circular RNA in pancreatic islets leads to a decrease in the expression of key components of the secretory machinery of β-cells, resulting in impaired glucose- or KCl-induced insulin release and calcium signaling. The effect of the circular RNA is exerted at the transcriptional level and involves an interaction with the RNA-binding protein TAR DNA-binding protein 43 kDa (TDP-43). The level of this circularized intron is reduced in the islets of rodent diabetes models and of type 2 diabetic patients, possibly explaining their impaired secretory capacity. The study of this and other circular RNAs helps understanding β-cell dysfunction under diabetes conditions, and the etiology of this common metabolic disorder.
2020-09-21 | GSE134699 | GEO
Project description:Analysis of the transcriptome of cardiac tissue from mice trangenically engineered with a doxycycline inducible Tafazzin shRNA knockdown to mimic the loss of function of Tafazzin in Barth syndrome. ShRNA induced knockdown mice were compared to wildtype littermates also fed the doxycyline diet. The hypothesis was to investigate adaptive metabolic and compensatory gene transcriptional changes in myocardium of the mouse model of Barth syndrome Total RNA obtained from 2 month old cardiac tissue from the doxycycline inducible shRNA Tafazzin knockdown mouse model of Barth syndrome compared to wildtype littermates also fed 625 mg/Kg doxycycline diet
2011-11-05 | E-GEOD-33452 | biostudies-arrayexpress