Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Mitofusin agonists enhance long-term engraftment and potency of HSC cultures in vivo.

ABSTRACT: Umbilical cord blood (CBU) is a valuable source of hematopoietic stem cells (HSCs) due to its superior donor compatibility and lower incidence of graft-versus-host disease. However, its limited HSC content restricts its use in adult transplantation, necessitating new targets for ex vivo expansion and improved HSC potency. Mitofusin 2 (MFN2), a mitochondrial membrane fusion protein, is necessary for preserving HSC function and agonists of mitofusin activity have been characterized. We report that ex vivo culture of CBU HSCs with mitofusin agonists (MAs) enhances long-term repopulating activity by over five-fold in both primary and secondary transplantation assays without changes of total nucleated cells or phenotypic HSCs. Mechanistically, MA-treated HSCs show suppressed protein synthesis, increased autophagic flux, and elevated lysosomal acidification. Transcriptomic analysis implicates downregulation of MTOR signaling, and immunoprecipitation studies confirm a direct interaction between MFN2 and MTOR. These data support a model in which fusion-competent MFN2 sequesters MTOR, promoting a catabolic state that preserves HSC potency. Our findings suggest a novel MFN2–MTOR regulatory axis that enhances the functional expansion of human HSCs for potential therapeutic application.

ORGANISM(S): Homo sapiens

PROVIDER: GSE311386 | GEO | 2025/11/26

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Molecular characterization of hematopoietic stem cells after in vitro amplification on biomimetic 3D PDMS cell culture scaffoldsMolecular characterization of hematopoietic stem cells after in vitro amplification on biomimetic 3D PDMS cell culture scaffolds

Project description:Hematopoietic stem cell transplantation (HSCT) is successfully applied since the late 1950s, however, its efficacy still needs to be improved. A promising strategy is to transplant high numbers of pluripotent hematopoietic stem cells (HSCs). Therefore, an advanced ex vivo culture system is needed that supports the proliferation and maintains the pluripotency of HSC to override possible limitations in cell numbers gained from donors. To model the natural HSC niche in vitro and thus, to amplify high numbers of undifferentiated HSCs, we used an optimized HSC cell culture medium in combination with artificial 3D bone marrow-like scaffolds made of polydimethylsiloxane (PDMS). After 14 days in vitro (DIV) cell culture, we performed transcriptome and proteome analysis of the whole cell populations. Ingenuity pathway analysis (IPA) indicated that our 3D PDMS cell culture scaffolds activated interleukin, SREBP, mTOR and FOXO signaling pathways as well as the HSC metabolism, which we confirmed by ELISA, Western blot and metabolic flux analysis. These molecular signaling pathways and HSC metabolism are well known to promote the expansion HSCs and are involved in their pluripotency maintenance. After selection and enrichment of immature CD34-positive/CD38-negative HSCs using FACS sorting, we could confirm our findings by another proteome analysis followed by IPA. Thus, we could show that our 3D bone marrow-like PDMS scaffolds activate key molecular signaling pathways to amplify the numbers of undifferentiated HSC efficiently ex vivo.

2021-11-10 | PXD025849 | Pride

Mitofusin agonists enhance long-term engraftment and potency of HSC cultures in vivo.

Project description:Mitofusin agonists enhance long-term engraftment and potency of HSC cultures in vivo.

| PRJNA1369388 | ENA

Mutant ASXL1 induces age-related expansion of phenotypic hematopoietic stem cells through activation of Akt/mTOR pathway

Project description:Somatic mutations of ASXL1 are frequently detected in age-related clonal hematopoiesis (CH). However, how ASXL1 mutations drive CH remains elusive. Using knockin (KI) mice expressing a C-terminally truncated form of ASXL1-mutant (ASXL1-MT), we examined the influence of ASXL1-MT on physiological aging in hematopoietic stem cells (HSCs). HSCs expressing ASXL1-MT display competitive disadvantage after transplantation. Nevertheless, in genetic mosaic mouse model, they acquire clonal advantage during aging, recapitulating CH in humans. Mechanistically, ASXL1-MT cooperates with BAP1 to deubiquitinate and activate AKT. Overactive Akt/mTOR signaling induced by ASXL1-MT results in aberrant proliferation and dysfunction of HSCs associated with age-related accumulation of DNA damage. Treatment with an mTOR inhibitor rapamycin ameliorates aberrant expansion of the HSC compartment as well as dysregulated hematopoiesis in aged ASXL1-MT KI mice. Our findings suggest that ASXL1-MT provokes dysfunction of HSCs, whereas it confers clonal advantage on HSCs over time, leading to the development of CH.

2021-02-08 | MSV000086816 | MassIVE

Genome-wide screen identifies Runx2 as a novel regulator of hematopoietic stem cell expansion and T-cell commitment

Project description:Self-renewing multipotent hematopoietic stem cells (HSCs) are a rare but important cell population which can reconstitute the entire blood and immune system following transplantation. Due to their rarity, it has been difficult to comprehensively study the mechanisms regulating HSC activity. However, recent improvements in hematopoietic stem and progenitor cell (HSPC) culture methods using polyvinyl alcohol (PVA)-based media now facilitate large-scale ex vivo HSC expansion. Here we performed a genome-wide CRISPR knockout (KO) screen in primary mouse HSPCs to discover novel regulators of ex vivo expansion. The screen identified Runx2 as a strong negative regulator of HSC expansion, which we validated using ex vivo and in vivo assays. Loss of Runx2 increased the frequency of immunophenotypic HSCs in HSPC cultures by ~3-fold. Following expansion, Runx2-KO HSCs engrafted at ~5-fold higher levels in competitive transplantation assays. Non-cultured Runx2-KO HSCs also displayed enhanced reconstitution potential, but loss of Runx2 did not alter blood parameters. Notably however, T-cell reconstitution was diminished from Runx2-KO HSCs, and we further validated an additional role for Runx2 in T-cell commitment using ex vivo and in vivo assays. In summary, we have identified a multifaceted role for Runx2 in HSCs, as a negative regulator of HSC self-renewal and as a facilitator of T-cell commitment. These results will contribute understanding transcriptional regulation of hematopoiesis and improve HSC therapies.

2025-11-27 | GSE288012 | GEO

Mitochondrial hetereogeneity in hematopoietic stem cells (HSC)

Project description:Quiescence is a fundamental property that maintains hematopoietic stem cells (HSCs)’ potency throughout life. Quiescent HSCs are thought to rely on glycolysis for their energy but the overall metabolic properties of HSCs remain incompletely understood. Using combined approaches including single cell RNA-Seq we show that mitochondrial membrane potential (MMP) distinguishes the quiescent from cycling-primed HSCs. We found that primed but not quiescent HSCs relied readily on glycolysis. Notably, in vivo inhibition of glycolysis robustly enhanced the competitive repopulation ability of primed HSCs. We further show that HSC quiescence is maintained by an abundance of large lysosomes. Repression of lysosomal activation led to further enlargement of lysosomes, while repressing mTOR activation and glucose uptake. This also induced increased lysosomal sequestration of mitochondria and enhanced the competitive repopulation ability of primed HSCs by over 90-fold in vivo. These findings show that restraining lysosomal activity is key in preserving HSC quiescence and potency, and may be therapeutically relevant.

2020-03-05 | GSE141457 | GEO

RNA-seq in human hematopoietic stem cells (HSCs) cultures on 3 different materials

Project description:Hematopoietic stem cell transplantation (HSCT) is successfully applied since the late 1950s, however, its efficacy still needs to be improved. A promising strategy is to transplant high numbers of pluripotent hematopoietic stem cells (HSCs). Therefore, an advanced ex vivo culture system is needed that supports the proliferation and maintains the pluripotency of HSC to override possible limitations in cell numbers gained from donors. To model the natural HSC niche in vitro and thus, to amplify high numbers of undifferentiated HSCs, we used an optimized HSC cell culture medium in combination with artificial 3D bone marrow-like scaffolds made of polydimethylsiloxane (PDMS). After 14 days in vitro (DIV) cell culture, we performed transcriptome and proteome analysis of the whole cell populations. Ingenuity pathway analysis (IPA) indicated that our 3D PDMS cell culture scaffolds altered PI3K/AKT/mTOR pathways and activated SREBP, HIF1α and FOXO signaling leading to metabolic adaptations, which we confirmed by ELISA, Western blot and metabolic flux analysis. These molecular signaling pathways can promote the expansion HSCs and are involved in their pluripotency maintenance. Thus, we could show that our 3D bone marrow-like PDMS scaffolds activate key molecular signaling pathways to amplify the numbers of undifferentiated HSCs efficiently ex vivo.

2021-10-27 | GSE178657 | GEO

RNAseq from Mfn1/2 knockout MEFs with adipogenic differentiation

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

Endogenous interactomes of MFN1 and MFN2 provide novel insights into interorganelle communication and autophagy

Project description:Mitofusin-1 (MFN1) and Mitofusin-2 (MFN2) are key players in mitochondrial fusion, endoplasmic reticulum (ER)-mitochondria yuxtaposition, and autophagy. However, the mechanisms by which these proteins participate in these processes remain poorly understood. To better understand their functions, we studied the interactomes of these two proteins. To this end, we used CRISPR/Cas9 technology to insert an HA-tag in the C-terminal domain of MFN1 and MFN2 and generated HeLa cell lines that endogenously expressed MFN1-HA or MFN2-HA, respectively. HA-pulldown followed by mass spectrometry identified potential interactors of MFN1 and MFN2. A substantial proportion of interactors were common for MFN1 and MFN2 and were regulated by nutrient deprivation. We validated novel ER and endosomal partners of MFN1 and/or MFN2 with a potential role in interorganelle communication. We characterized RAB5C as an endosomal modulator of mitochondrial dynamics through its interaction with MFN1 and SLC27A2 as a novel partner of MFN2 relevant in autophagy. Our findings reveal that MFN proteins participate in nutrient-modulated pathways involved in organelle communication.

2025-07-16 | PXD043168 | Pride

MYCT1 CONTROLS ENVIRONMENTAL SENSING IN HUMAN HEMATOPOIETIC STEM CELLS

Project description:Hematopoietic stem cells (HSC) rely on a unique regulatory machinery that facilitates life-long blood production and enables reconstitution of the entire hematopoietic system upon transplantation. However, the biological processes governing human HSC self-renewal and engraftment ability are poorly understood and challenging to recapitulate ex vivo to facilitate robust human HSC expansion. We discovered a novel HSC regulatory protein, MYCT1 (MYCT target 1), that is selectively expressed in endothelial cells (EC) and undifferentiated human HSPCs but becomes drastically downregulated during HSC culture. Lentiviral knockdown of MYCT1 in human foetal liver and cord blood HSPCs revealed a critical role for MYCT1 in governing human HSPC expansion and engraftment ability. Single cell RNAseq of human CB HSPCs after MYCT1 knockdown and overexpression revealed that MYCT1 governs HSC functional competence and modulates cellular properties essential for HSC stemness, such as low mitochondrial metabolic activity. Indeed, restoring the compromised MYCT1 expression in cultured human CB HSPCs improved ex vivo expansion of the most undifferentiated human HSPCs and enhanced their engraftment ability. We found that MYCT1 is localized in the endosomal membrane and interacts with vesicle trafficking regulators and signalling machinery essential for HSC and EC function. Loss of MYCT1 led to excessive endocytosis and hyperactive signalling responses to cytokines, whereas restoring MYCT1 expression in cultured CB HSPCs balanced the abnormal endocytosis associated with prolonged culture and fine-tuned signalling responses. Our work identifies MYCT1-moderated endocytosis and environmental sensing as an essential regulatory mechanism required to preserve human HSC stemness, and pinpoints silencing of MYCT1 as a critical contributor to the dysfunction of cultured human HSCs that needs to be addressed to improve human HSC culture strategies.

2024-04-15 | PXD042257 | Pride

Mitofusin 2 expression in muscle decreases during aging and generates a gene signature characteristic of aged muscle

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

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data