RNA-seq of overgrown interscapular adipose tissue with biallelic MFN2 mutations
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE97156 | GEO | 2017/04/12
SECONDARY ACCESSION(S): PRJNA380818
REPOSITORIES: GEO
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Project description:Mitofusin-2 (MFN2) is an outer mitochondrial membrane protein essential for mitochondrial networking in most cells. Autosomal dominant mutations in the MFN2 gene cause Charcot-Marie-Tooth type 2A disease (CMT2A), a severe and disabling sensory-motor neuropathy with impact on the entire nervous system. To date, no curative treatment is available. In the paper we propose a novel therapeutic strategy tailored to correct the root genetic defect of CMT2A. In our approach, while mutant and wild-type MFN2 mRNA are inhibited by RNA interference (RNAi), the wild-type protein is restored by overexpressing a cDNA encoding a functional MFN2, modified to be resistant to RNAi. This strategy allows proper MFN2 molecular correction in vivo in the MitoCharc1 CMT2A transgenic mouse model after cerebrospinal fluid (CSF) delivery of the constructs via adenoassociated virus 9 (AAV9) in newborn mice. To identify the therapeutic molecular mechanisms and the pathway that are modulated, we have compared the bulk RNA expression profile of spinal cord from one month old wild type (WT) mice and MitoCharc1 transgenic mice (B6;D2-Tg(Eno2-MFN2*R94Q)L51Ugfm/J) which encode the mutant human MFN2*R94Q under the neuron specific rat enolase (Eno2) promoter, as potential mouse model to test the therapeutic approach. We performed gene expression profiling analysis using data (RNA-seq) obtained from 4 wild type mice and 8 MitoCharch1 transgenic mice at one time point.
2023-11-29 | GSE201264 | GEO
Project description:Objective: A biallelic missense mutation in mitofusin 2 (MFN2) causes multiple symmetric lipomatosis and partial lipodystrophy, implicating disruption of mitochondrial fusion or interaction with other organelles in adipocyte differentiation, growth and/or survival. In this study, we aimed to document the impact of loss of mitofusin 1 (Mfn1) or 2 (Mfn2) on adipogenesis in cultured cells. Methods: We characterised adipocyte differentiation of wildtype (WT), Mfn1-/- and Mfn2-/- mouse embryonic fibroblasts (MEFs) and 3T3-L1 preadipocytes in which Mfn1 or 2 levels were reduced using siRNA. Results: Mfn1-/- MEFs displayed striking fragmentation of the mitochondrial network, with surprisingly enhanced propensity to differentiate into adipocytes, as assessed by lipid accumulation, expression of adipocyte markers (Plin1, Fabp4, Glut4, Adipoq), and insulin-stimulated glucose uptake. RNA sequencing revealed a corresponding pro-adipogenic transcriptional profile including Pparg upregulation. Mfn2-/- MEFs also had a disrupted mitochondrial morphology, but in contrast to Mfn1-/- MEFs they showed reduced expression of adipocyte markers. Mfn1 and Mfn2 siRNA mediated knockdown studies in 3T3-L1 adipocytes generally replicated these findings. Conclusions: Loss of Mfn1 but not Mfn2 in cultured pre-adipocyte models is pro-adipogenic. This suggests distinct, non-redundant roles for the two mitofusin orthologues in adipocyte differentiation.
2023-06-01 | GSE232502 | GEO
Project description:Mitochondrial dysfunction has been reported in obesity and insulin resistance, but primary genetic mitochondrial dysfunction is generally not associated with these, arguing against a straightforward causal relationship. A rare exception, recently identified in humans, is a syndrome of lower body adipose loss, leptin-deficient severe upper body adipose overgrowth, and insulin resistance caused by the p.Arg707Trp mutation in MFN2, encoding mitofusin-2. How this selective perturbation of mitochondrial function leads to tissue- and adipose depot-specific growth abnormalities and systemic biochemical perturbation is unknown. To address this, Mfn2R707W/R707W knock-in mice were generated and phenotyped on chow and high fat diets. Electron microscopy revealed adipose-specific mitochondrial morphological abnormalities. Oxidative phosphorylation by isolated mitochondria was unperturbed, but the cellular integrated stress response was activated in adipose tissue. Fat mass and distribution, body weight, and systemic glucose and lipid metabolism were unchanged, however serum leptin and adiponectin concentrations, and their secretion from adipose explants were reduced. Pharmacological induction of the integrated stress response in wild-type adipocytes also reduced secretion of leptin and adiponectin, suggesting an explanation for the in vivo findings. These data suggest that the p.Arg707Trp MFN2 mutation perturbs mitochondrial morphology and activates the integrated stress response selectively in adipose tissue. In mice, this does not disrupt most adipocyte functions or systemic metabolism, whereas in humans it is associated with pathological adipose remodelling and metabolic disease. In both species, disproportionate effects on leptin secretion may relate to cell autonomous induction of the integrated stress response.
2023-01-01 | GSE210771 | GEO
Project description:The dynamin-like GTPases Mitofusin 1 and 2 (Mfn1 and Mfn2) are essential for mitochondrial function, which has been principally attributed to their regulation of fission/fusion dynamics. Here, we report that Mfn1 and 2 are critical for glucose-stimulated insulin secretion (GSIS) primarily through control of mtDNA content. Whereas Mfn1 and Mfn2 individually were dispensable for glucose homeostasis, combined Mfn1/2 deletion in β-cells reduced mtDNA content, induced impaired mitochondrial morphology and networking fragmentation, and impaired decreased respiratory function, ultimately resulting in severe glucose intolerance. Importantly, gene dosage studies unexpectedly revealed that Mfn1/2 control of glucose homeostasis was dependent on maintenance of mtDNA content, rather than mitochondrial structure. Indeed, pharmacologic mitofusin agonists rescued islet mtDNA depletion due to mitofusin deficiency independent of changes on mitochondrial structure. Mfn1/2 maintain mtDNA content by regulating the expression of the crucial mitochondrial transcription factor Tfam, as Tfam overexpression ameliorated the reduction in mtDNA content and GSIS in Mfn1/2-deficient β-cells. Thus, the primary physiologic role of Mfn1 and 2 in β-cells is coupled to preservation of mtDNA content rather than mitochondrial architecture, and Mfn1 and 2 may be promising targets to overcome mitochondrial dysfunction and restore glucose control in diabetes.
2022-02-16 | GSE194204 | GEO
Project description:The majority of diabetics are susceptible to cardiac dysfunction and heart failure, while conventional drug therapy cannot correct diabetic cardiomyopathy (DCM) progression. Herein, we assessed the potential role and therapeutic value of ubiquitin-specific protease 28 (USP28) on the metabolic vulnerability of DCM. PPARα-/- in the db/db background mice were constructed to check the mechanism of USP28 in vivo. Inducible cardiac-specific deletion of Mfn2 in the db/db background mice was utilized to evaluate USP28-mediated cardioprotection. chromatin immunoprecipitation (ChIP) assays revealed that PPARα promote mitofusin 2 (Mfn2) transcription, thereby impeding mitochondrial morphofunctional defects.
2023-10-15 | GSE244905 | GEO
Project description:Inter-organelle contact and communication between mitochondria (Mito) and endoplasmic reticulum (ER), also known as sarcoplasmic reticulum (SR) in cardiomyocytes (CM), play vital roles in the maintenance of Mito and SR properties and cellular homeostasis. Here, we tested the hypothesis that the formin, Diaphanous-1 (DIAPH1), which regulates actin dynamics and signal transduction, contributes to these processes. Mice bearing CM-specific deletion of Diaph1 displayed reduced injury and superior functional recovery after the induction of cardiac ischemia and reperfusion (I/R). Studies in DIAPH1-silenced human induced pluripotent stem cell-derived CMs (HiPSC-CMs) and murine hearts devoid of CM-Diaph1 revealed that DIAPH1 interacts directly with Mitofusin-2 (MFN2) to regulate Mito-SR contact, Mito turnover, mitophagy, and oxidative stress. Ischemic murine hearts and human heart biopsies revealed more robust DIAPH1-MFN2 interaction vs. that observed in non-ischemic hearts. Solution structure studies affirm this interaction and reveal strong pH-dependent interaction between the Diaphanous Inhibitory Domain (DID) and the cytosolic GTPase domain of MFN2. In HiPSC-CMs, introduction of synthetic linkers, which reduce the Mito-SR distance, mitigated the cardioprotective benefits of Diaph1 deletion. Finally, DIAPH1 binding to the cytoplasmic domain of receptor for advanced glycation endproduct (RAGE) supports signal transduction and contributes to I/R injury in the heart; in HiPSC-CMs, small molecule antagonism of RAGE-DIAPH1 reduced DIAPH1-MFN2 interaction and increased Mito-SR distance. This work establishes fundamental roles for DIAPH1-MFN2 interaction in the regulation of Mito-SR contact networks that control responses to ischemic stress. Targeting pathways that regulate DIAPH1-MFN2 may facilitate recovery from cardiac ischemic injury.
2022-09-28 | GSE214149 | GEO
Project description:This SuperSeries is composed of the following subset Series: GSE35551: Penetrance of biallelic SMARCAL1 mutations is associated with environmental and genetic disturbances of gene expression (1) GSE35552: Penetrance of biallelic SMARCAL1 mutations is associated with environmental and genetic disturbances of gene expression (2) GSE35553: Penetrance of biallelic SMARCAL1 mutations is associated with environmental and genetic disturbances of gene expression (3) Refer to individual Series
2012-04-04 | E-GEOD-35554 | biostudies-arrayexpress
Project description:Mitochondrial fusion and fission proteins regulate mitochondrial quality control and mitochondrial metabolism. In turn, mitochondrial dysfunction is associated with aging, although its causes are still under debate. Here, we show that aging is characterized by a progressive reduction of Mitofusin 2 (Mfn2) in mouse skeletal muscle and that skeletal muscle Mfn2 ablation in mice generates a gene signature linked to aging. Furthermore, muscle Mfn2-deficient mice show unhealthy aging characterized by altered metabolic homeostasis and sarcopenia. Mfn2 deficiency impairs mitochondrial quality control, which contributes to an exacerbated age-related mitochondrial dysfunction. Surprisingly, aging-induced Mfn2 deficiency triggers a ROS-dependent retrograde signaling pathway through induction of HIF1 transcription factor and BNIP3. This pathway ameliorates mitochondrial autophagy and minimizes mitochondrial damage. Our findings reveal that repression of Mfn2 in skeletal muscle during aging is determinant for the loss of mitochondrial quality, contributing to age-associated metabolic alterations and loss of muscle fitness. Quadriceps muscle from four mice per genotype were used (Control young (6 month-old), Mfn2KO young (6-month-old), control old (22-month-old) and Mfn2KO old (22-month-old)
2016-08-08 | E-GEOD-71501 | biostudies-arrayexpress
Project description:We have generated CRISPR edited versions of hESC line MShef11 to produce MFN2 R94Q/+ and MFN2 R94Q/R94Q lines as a model for Charcot Marie Tooth Disease (CMT) 2A. This were differentiated to limb innervating motor neurons, the predominantly affected cell time in CMT2A and RNA was examined to investigate differences in cell lines.
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