Dynamin 2 regulates mitochondrial mitotic fission in pulmonary hypertension
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE327258 | GEO | 2026/05/01
REPOSITORIES: GEO
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Project description:Mitotic fission is increased in hyperproliferative, apoptosis-resistant diseases, such as pulmonary arterial hypertension (PAH). PAH’s fissogenic phenotype includes activation of the fission mediator, dynamin related protein 1 (Drp1), which must complex with its adaptor proteins to cause fission. Drp1-induced fission has been therapeutically targeted in experimental PAH. Here we examine the role of two recently discovered, poorly understood, Drp1 adapter proteins, mitochondrial dynamics protein of 49 and 51 kDa (MiD49 and MiD51) in normal vascular cells and explore the role of their dysregulation in the pathogenesis of PAH. MiDs are increased in PAH PASMC. This accelerates Drp1-mediated mitotic fission, which increases cell proliferation and decreases apoptosis. Silencing MiDs (but not Fis1 or MFF) promotes mitochondrial fusion and G1-phase cell cycle arrest through an ERK1/2 and CDK4-dependent mechanism. Augmenting MiDs in normal cells causes fission and recapitulates the PAH phenotype. MiD upregulation results from decreased microRNA-34a-3p (miR-34a-3p) expression. Circulatory miR34a-3p expression is decreased in PAH patients as well as in preclinical models of PAH. Silencing MiDs or augmenting miR-34a-3p regresses experimental PAH. We used microarrays to identify differences in miR expression in pulmonary artery smooth muscle cells (PASMC) taken from either pulmonary arterial hypertension patients or healthy controls
2018-01-31 | GSE108707 | GEO
Project description:Mitochondrial fusion and fission, which are strongly related to normal mitochondrial function, are referred to as mitochondrial dynamics. Mitochondrial fusion defects in the liver cause a non-alcoholic steatohepatitis-like phenotype and liver cancer. However, whether mitochondrial fission defect directly impair liver function and stimulate liver disease progression, too, is unclear. Dynamin-related protein 1 (DRP1) is a key factor controlling mitochondrial fission. We hypothesized that DRP1 defects are a causal factor directly involved in liver disease development and stimulate liver disease progression. Drp1 defects directly promoted endoplasmic reticulum (ER) stress, hepatocyte death, and subsequently induced infiltration of inflammatory macrophages. Drp1 deletion increased the expression of numerous genes involved in the immune response and DNA damage in Drp1LiKO mouse primary hepatocytes. We administered lipopolysaccharide (LPS) to liver-specific Drp1-knockout (Drp1LiKO) mice and observed an increased inflammatory cytokine expression in the liver and serum caused by exaggerated ER stress and enhanced inflammasome activation. This study indicates that Drp1 defect-induced mitochondrial dynamics dysfunction directly regulates the fate and function of hepatocytes and enhances LPS-induced acute liver injury in vivo.
2020-08-28 | GSE156982 | GEO
Project description:Well-balanced mitochondrial fission and fusion processes are essential for nervous system development. Loss of function of the main mitochondrial fission mediator, dynamin-related protein 1 (Drp1), is lethal early during embryonic development or around birth, but the role of mitochondrial fission in adult neurons remains unclear. Here we show that inducible Drp1 ablation in neurons of the adult mouse forebrain results in progressive, neuronal subtype-specific alterations of mitochondrial morphology in the hippocampus that are marginally responsive to antioxidant treatment. Furthermore, DRP1 loss affects synaptic transmission and memory function. Although these changes culminate in hippocampal atrophy, they are not sufficient to cause neuronal cell death within 10 weeks of genetic Drp1 ablation. Collectively, our in vivo observations clarify the role of mitochondrial fission in neurons, demonstrating that Drp1 ablation in adult forebrain neurons compromises critical neuronal functions without causing overt neurodegeneration.
2016-08-25 | PXD004890 | Pride
Project description:With the advent of exome sequencing, a growing number of children are being identified with de novo loss of function mutations in the large GTPase essential for mitochondrial fission - Dynamin Related Protein 1 (DRP1); these mutations result in severe neurodevelopmental phenotypes such as developmental delay, optic atrophy, and epileptic encephalopathies. Though it is established that mitochondrial fission is an essential precursor to the rapidly changing metabolic needs of the developing cortex, it is not understood how identified mutations in different domains of DRP1 uniquely disrupt cortical development and synaptic maturation. We leveraged the power of both high-resolution imaging and induced pluripotent stem cells (iPSCs) harboring DRP1 mutations in either the GTPase or stalk domains to model early stages of cortical development. Transcriptional profiling of mutant DRP1 cortical neurons during maturation, as well as imaging of organelle dynamics and neuronal synapses, strongly suggests that altered mitochondrial morphology of DRP1 mutant neurons affect synaptic development leading to pathogenic dysregulation of synaptic activity.
2025-06-30 | GSE296512 | GEO
Project description:The Dynamin-related GTPase, Drp1 (encoded by Dnm1l) plays a central role in mitochondrial fission and is requisite for numerous cellular processes however its role in oxidative metabolism remains unclear. Herein, we show that among human tissues, skeletal muscle exhibits the strongest correlations with the DNM1L gene. Knockdown of Drp1 (Drp1-KD) promoted mitochondrial hyperfusion in the muscle of male mice. Reduced fatty acid oxidation and accumulation of intramyocellular lipids along with increased muscle succinate was observed in Drp1-KD muscle. Muscle Drp1-KD reduced Complex II assembly and activity as a consequence of diminished mitochondrial translocation of succinate dehydrogenase assembly factor 2 (Sdhaf2). Restoration of Sdhaf2, normalized Complex II activity and lipid oxidation in Drp1-KD myocytes. Drp1 appears critical in maintaining mitochondrial Complex II assembly and fatty acid oxidation, suggesting a mechanistic link between mitochondrial morphology and skeletal muscle lipid metabolism which is of clinical significance in combatting metabolic diseases.
2024-01-26 | GSE248081 | GEO
Project description:Mitochondria undergo continuous cycles of fission and fusion to promote inheritance, regulate quality control, and mitigate organelle stress. More recently, this process of mitochondrial dynamics has been demonstrated to be highly sensitive to nutrient supply, ultimately conferring bioenergetic plasticity to the organelle. However, whether regulators of mitochondrial dynamics play a causative role in nutrient regulation remains unclear. In this study, we generated a cellular loss-of-function model for dynamin-related protein 1 (DRP1), the primary regulator of outer membrane mitochondrial fission. Loss of DRP1 (shDRP1) resulted in extensive ultrastructural and functional remodeling of mitochondria, characterized by pleomorphic enlargement, increased electron density of the matrix, and defective NADH and succinate oxidation. Despite increased mitochondrial size and volume, shDRP1 cells exhibited reduced cellular glucose uptake and mitochondrial fatty acid oxidation. Untargeted transcriptomic profiling revealed severe downregulation of genes required for cellular and mitochondrial calcium homeostasis, inhibition of ATP-stimulated calcium flux, and impaired substrate oxidation stimulated by calcium levels. The insights obtained herein suggest that DRP1 regulates fatty acid oxidation by altering whole-cell and mitochondrial calcium dynamics. These findings are relevant to the targetability of mitochondrial fission and have clinical relevance in the identification of treatments for fission-related pathologies such as hereditary neuropathies, inborn errors in metabolism, cancer, and chronic diseases.
2021-09-13 | GSE162983 | GEO
Project description:The maintenance of skeletal muscle mass is critically dependent upon mitochondrial quality control, including balanced mitochondrial dynamics and mitophagy. Dynamin-related protein 1 (Drp1), a key mediator of mitochondrial fission, plays an important role in these processes. However, the precise mechanisms by which Drp1 regulates mitochondrial integrity and muscle mass remain inadequately understood. Here, we show that acute Drp1 deletion from skeletal muscle impairs mitochondrial activity, increases Parkin-mediated mitophagy, progressively reduces mitochondrial DNA (mtDNA) content, and ultimately causes severe muscle atrophy. Interestingly, dual deletion of Drp1 and Parkin from skeletal muscle restored mtDNA content, but did not prevent muscle loss. Mechanistically, Drp1 deletion disrupted mitochondrial respiratory chain activity, which suppressed extracellular signal-regulated kinase 1/2 (Erk1/2) signaling and downregulated the nuclear receptor subfamily 4 group member 1 (Nur77), a regulator of muscle quality. Finally, clenbuterol, a β2-adrenergic receptor agonist, activated Erk1/2 signaling, restored Nur77 expression, and rescued muscle atrophy. Collectively, our findings identify a Drp1-Erk1/2-Nur77 signaling axis that connects mitochondrial integrity to the preservation of skeletal muscle mass and represents a potential therapeutic avenue for muscle degeneration in mitochondrial and metabolic disorders.
2025-12-08 | GSE295479 | GEO
Project description:Dynamin 2 regulates mitochondrial mitotic fission in pulmonary hypertension
| PRJNA1450060 | ENA
Project description:Dynamin-related protein 1 (Drp1, encoded by DNM1L) is a key regulator of mitochondrial fission, yet its functional role remains controversial, likely due to isoform-specific effects arising from alternative splicing. Conventional short-read RNA sequencing complicates the characterization of full-length isoforms, limiting our understanding of their biological significance. To resolve this, we applied a targeted long-read sequencing approach to capture full-length DNM1L transcripts in primary human left ventricle and iPSC-derived cardiomyocytes. We recovered the complete spectrum of annotated isoforms and found broadly conserved expression patterns, with isoforms 1-4 expressed most abundantly. Recombinant protein assays further revealed that isoform abundance does not directly predict enzymatic activity, emphasizing the need for combined expression and functional analyses. Extending this framework to mouse, we profiled Dnm1l isoforms across six tissues (brain, heart, skeletal muscle, lung, kidney, and spleen) using the same long-read pipeline. All annotated isoforms were recovered, with distinct tissue-enriched expression patterns. Notably, several isoforms displayed strong tissue specificity, with subsets preferentially expressed in brain, heart, or skeletal muscle, suggesting specialized regulatory roles in mitochondrial dynamics. Functional rescue experiments in Drp1-knockout mouse embryonic fibroblasts revealed isoform-dependent differences in mitochondrial fission activity. Isoforms lacking the A-insert within the GTPase domain (e.g., isoforms b and d) robustly restored mitochondrial fragmentation, whereas the canonical brain-enriched isoform (isoform e) and a muscle-enriched isoform (isoform o) exhibited only partial rescue. These results indicate that inclusion of exons 2 and 3 may negatively regulate Drp1 fission activity. Together, our work establishes a cross-species atlas of DNM1L/Dnm1l isoforms, integrating long-read transcriptomics with functional assays. We demonstrate that Drp1 isoform diversity is tightly linked to tissue identity and that structural differences among isoforms critically shape mitochondrial fission activity, offering new insights into the pathophysiology of Drp1 in human health and disease.
2025-10-01 | GSE308731 | GEO
Project description:Global deficiency of catalytic subunit Ppp3cb, and tissue-specific ablation of regulatory subunit Ppp3r1 from skeletal muscle but not adipose tissue or liver led to protection from high-fat diet induced obesity and comorbid sequelæ. Ser637 hyperphosphorylation of dynamin-related protein 1 (Drp1) in skeletal muscle of calcineurin-deficient mice was associated with mitochondrial elongation into power-cable shaped filaments, increased mitochondrial respiration, but attenuated exercise performance. Mice used for microarray analyses were all male, and chronically exposed to HFD for at least 8 weeks.
2015-07-22 | E-GEOD-71174 | biostudies-arrayexpress