Metabolic adaptations direct cell fate during tissue regeneration [DMaKG_Mice_RNA-seq]
Ontology highlight
ABSTRACT: Although cell fate specification is generally attributed to transcriptional regulation, emerging data also indicate a role for molecules linked with intermediary metabolism. For example, α-ketoglutarate (αKG), which fuels energy production and biosynthetic pathways in the tricarboxylic acid (TCA) cycle, is also a co-factor for chromatin-modifying enzymes1-3. Nevertheless, whether TCA cycle metabolites regulate cell fate during tissue homeostasis and regeneration remains unexplored. In the intestine, we discovered unexpectedly heterogeneous expression of TCA cycle enzymes, with αKG dehydrogenase complex components4-6 upregulated in the absorptive lineage and downregulated in the secretory lineage. Using genetically modified mouse models and organoids, we demonstrated a dual, lineage-specific role for 2-oxoglutarate dehydrogenase (OGDH), the enzymatic subunit of αKG dehydrogenase complex. In the absorptive lineage, OGDH is upregulated by Hnf4 transcription factors to maintain the bioenergetic and biosynthetic needs of enterocytes. In the secretory lineage, OGDH is downregulated through a process that, when modeled, increases αKG levels and stimulates secretory cell differentiation. Consistent with this, in murine colitis models with impaired secretory cell number and maturation, OGDH inhibition or αKG supplementation reversed these impairments and promoted tissue healing. Hence, OGDH dependency is lineage-specific, and its regulation helps direct cell fate, offering insights for targeted therapies in regenerative medicine.
Project description:Although cell fate specification is generally attributed to transcriptional regulation, emerging data also indicate a role for molecules linked with intermediary metabolism. For example, α-ketoglutarate (αKG), which fuels energy production and biosynthetic pathways in the tricarboxylic acid (TCA) cycle, is also a co-factor for chromatin-modifying enzymes1-3. Nevertheless, whether TCA cycle metabolites regulate cell fate during tissue homeostasis and regeneration remains unexplored. In the intestine, we discovered unexpectedly heterogeneous expression of TCA cycle enzymes, with αKG dehydrogenase complex components4-6 upregulated in the absorptive lineage and downregulated in the secretory lineage. Using genetically modified mouse models and organoids, we demonstrated a dual, lineage-specific role for 2-oxoglutarate dehydrogenase (OGDH), the enzymatic subunit of αKG dehydrogenase complex. In the absorptive lineage, OGDH is upregulated by Hnf4 transcription factors to maintain the bioenergetic and biosynthetic needs of enterocytes. In the secretory lineage, OGDH is downregulated through a process that, when modeled, increases αKG levels and stimulates secretory cell differentiation. Consistent with this, in murine colitis models with impaired secretory cell number and maturation, OGDH inhibition or αKG supplementation reversed these impairments and promoted tissue healing. Hence, OGDH dependency is lineage-specific, and its regulation helps direct cell fate, offering insights for targeted therapies in regenerative medicine.
Project description:Although cell fate specification is generally attributed to transcriptional regulation, emerging data also indicate a role for molecules linked with intermediary metabolism. For example, α-ketoglutarate (αKG), which fuels energy production and biosynthetic pathways in the tricarboxylic acid (TCA) cycle, is also a co-factor for chromatin-modifying enzymes1-3. Nevertheless, whether TCA cycle metabolites regulate cell fate during tissue homeostasis and regeneration remains unexplored. In the intestine, we discovered unexpectedly heterogeneous expression of TCA cycle enzymes, with αKG dehydrogenase complex components4-6 upregulated in the absorptive lineage and downregulated in the secretory lineage. Using genetically modified mouse models and organoids, we demonstrated a dual, lineage-specific role for 2-oxoglutarate dehydrogenase (OGDH), the enzymatic subunit of αKG dehydrogenase complex. In the absorptive lineage, OGDH is upregulated by Hnf4 transcription factors to maintain the bioenergetic and biosynthetic needs of enterocytes. In the secretory lineage, OGDH is downregulated through a process that, when modeled, increases αKG levels and stimulates secretory cell differentiation. Consistent with this, in murine colitis models with impaired secretory cell number and maturation, OGDH inhibition or αKG supplementation reversed these impairments and promoted tissue healing. Hence, OGDH dependency is lineage-specific, and its regulation helps direct cell fate, offering insights for targeted therapies in regenerative medicine.
Project description:Although cell fate specification is generally attributed to transcriptional regulation, emerging data also indicate a role for molecules linked with intermediary metabolism. For example, α-ketoglutarate (αKG), which fuels energy production and biosynthetic pathways in the tricarboxylic acid (TCA) cycle, is also a co-factor for chromatin-modifying enzymes1-3. Nevertheless, whether TCA cycle metabolites regulate cell fate during tissue homeostasis and regeneration remains unexplored. In the intestine, we discovered unexpectedly heterogeneous expression of TCA cycle enzymes, with αKG dehydrogenase complex components4-6 upregulated in the absorptive lineage and downregulated in the secretory lineage. Using genetically modified mouse models and organoids, we demonstrated a dual, lineage-specific role for 2-oxoglutarate dehydrogenase (OGDH), the enzymatic subunit of αKG dehydrogenase complex. In the absorptive lineage, OGDH is upregulated by Hnf4 transcription factors to maintain the bioenergetic and biosynthetic needs of enterocytes. In the secretory lineage, OGDH is downregulated through a process that, when modeled, increases αKG levels and stimulates secretory cell differentiation. Consistent with this, in murine colitis models with impaired secretory cell number and maturation, OGDH inhibition or αKG supplementation reversed these impairments and promoted tissue healing. Hence, OGDH dependency is lineage-specific, and its regulation helps direct cell fate, offering insights for targeted therapies in regenerative medicine.
Project description:The tumor suppressor TP53 is mutated in the majority of human cancers, including over 70% of pancreatic ductal adenocarcinoma (PDAC). Wild-type p53 accumulates in response to cellular stress and regulates the expression of genes that alter cell fate and constrain tumorigenesis. p53 also modulates several cellular metabolic pathways, though it remains unclear whether particular p53-regulated metabolites contribute to tumor suppression or whether metabolic alterations driven by p53 mutation sustain cancer progression. Here, we show that restoring endogenous p53 function in cancer cells derived from a murine PDAC model driven by oncogenic Kras and a regulatable p53 short hairpin RNA (shRNA) rewires glucose and glutamine metabolism leading to the accumulation of α-ketoglutarate (αKG), an obligate substrate for several chromatin modifying enzymes. p53 induces transcriptional programs characteristic of premalignant differentiation, an effect that can be partially recapitulated by addition of cell permeable αKG. Similarly, enforcing αKG accumulation in p53-deficient PDAC cells though the inhibition of oxoglutarate (αKG) dehydrogenase (Ogdh), the enzyme that consumes αKG in the tricarboxylic acid cycle, reduces tumor-initiating capacity and promotes tumor cell differentiation. Decreases in 5-hydroxymethylcytosine (5hmC), an αKG-dependent chromatin modification, are associated with the appearance of p53 mutations in the transition from premalignant to de-differentiated malignant lesions, whereas increases in 5hmC accompany tumor cell differentiation triggered by either p53 restoration or Ogdh depletion. Together these data nominate αKG as an effector of p53-mediated tumor suppression whose accumulation in p53-deficient tumors can drive tumor cell differentiation and antagonize malignant progression.
Project description:Perturbations in intermediary metabolism contribute to the pathogenesis of acute myeloid leukemia (AML) and can produce therapeutically actionable dependencies. Here, we probed whether alpha-ketoglutarate (aKG) metabolism represents a specific vulnerability in AML. Using functional genomics, metabolomics, and mouse models, we identified the aKG dehydrogenase complex, which catalyzes the conversion of aKG to succinyl CoA, as a molecular dependency across multiple models of adverse-risk AML. Inhibition of 2-oxoglutarate dehydrogenase (OGDH), the E1 subunit of the aKG dehydrogenase complex, impaired AML progression and drove differentiation. Mechanistically, hindrance of aKG flux through the tricarboxylic acid (TCA) cycle resulted in rapid exhaustion of aspartate pools and blockade of de novo nucleotide biosynthesis, while cellular bioenergetics was largely preserved. Additionally, increased aKG levels following OGDH inhibition impacted the biosynthesis of other critical amino acids. Thus, this work has identified a previously undescribed, functional link between certain TCA cycle components and nucleotide biosynthesis enzymes across AML. This metabolic node may serve as a cancer-specific vulnerability amenable to therapeutic targeting in AML and perhaps in other cancers with similar metabolic wiring.
Project description:Perturbations in intermediary metabolism contribute to the pathogenesis of acute myeloid leukemia (AML) and can produce therapeutically actionable dependencies. Here, we probed whether alpha-ketoglutarate (aKG) metabolism represents a specific vulnerability in AML. Using functional genomics, metabolomics, and mouse models, we identified the aKG dehydrogenase complex, which catalyzes the conversion of aKG to succinyl CoA, as a molecular dependency across multiple models of adverse-risk AML. Inhibition of 2-oxoglutarate dehydrogenase (OGDH), the E1 subunit of the aKG dehydrogenase complex, impaired AML progression and drove differentiation. Mechanistically, hindrance of aKG flux through the tricarboxylic acid (TCA) cycle resulted in rapid exhaustion of aspartate pools and blockade of de novo nucleotide biosynthesis, while cellular bioenergetics was largely preserved. Additionally, increased aKG levels following OGDH inhibition impacted the biosynthesis of other critical amino acids. Thus, this work has identified a previously undescribed, functional link between certain TCA cycle components and nucleotide biosynthesis enzymes across AML. This metabolic node may serve as a cancer-specific vulnerability amenable to therapeutic targeting in AML and perhaps in other cancers with similar metabolic wiring.
Project description:The tricarboxylic acid (TCA) cycle is a central hub of cellular metabolism, oxidizing nutrients to generate reducing equivalents for energy production and critical metabolites for biosynthetic reactions. Despite the importance of the products of the TCA cycle for cell viability and proliferation, mammalian cells display diversity in TCA-cycle activity. How this diversity is achieved, and whether it is critical for establishing cell fate, remains poorly understood. Here we identify a non-canonical TCA cycle that is required for changes in cell state. Genetic co-essentiality mapping revealed a cluster of genes that is sufficient to compose a biochemical alternative to the canonical TCA cycle, wherein mitochondrially derived citrate exported to the cytoplasm is metabolized by ATP citrate lyase, ultimately regenerating mitochondrial oxaloacetate to complete this non-canonical TCA cycle. Manipulating the expression of ATP citrate lyase or the canonical TCA-cycle enzyme aconitase 2 in mouse myoblasts and embryonic stem cells revealed that changes in the configuration of the TCA cycle accompany cell fate transitions. During exit from pluripotency, embryonic stem cells switch from canonical to non-canonical TCA-cycle metabolism. Accordingly, blocking the non-canonical TCA cycle prevents cells from exiting pluripotency. These results establish a context-dependent alternative to the traditional TCA cycle and reveal that appropriate TCA-cycle engagement is required for changes in cell state.
Project description:Increased metabolic activity usually provides energy and nutrients for biomass synthesis and is indispensable for the progression of the cell cycle. Here, we found an unexpected role for α-ketoglutarate (αKG) generation in regulating cell cycle gene transcription. A reduction in cellular αKG levels triggered by malic enzyme 2 (ME2) or isocitrate dehydrogenase 1 (IDH1) depletion leads to a pronounced arrest in G1 phase, while αKG supplementation promotes cell cycle progression. Mechanistically, αKG directly binds to RNA polymerase II (RNAPII), increasing the level of RNAPII binding to the cyclin D1 gene promoter, consequently enhancing cyclin D1 transcription. Notably, αKG addition is sufficient to restore cyclin D1 expression in ME2- or IDH1- depleted cells, facilitating cell cycle progression and proliferation in these cells. Therefore, our findings reveal a previously unappreciated function of αKG in gene transcriptional regulation and cell cycle control.
Project description:Development and lineage choice are driven by interconnected transcriptional, epigenetic and metabolic changes. Specific metabolites, such as α-ketoglutarate (αKG), function as signalling molecules affecting the activity of chromatin-modifying enzymes. However, how metabolism coordinates cell-state changes, especially in human pre-implantation development, remains unclear. Here we uncover that inducing naive human embryonic stem cells towards the trophectoderm lineage results in considerable metabolic rewiring, characterized by αKG accumulation. Elevated αKG levels potentiate the capacity of naive embryonic stem cells to specify towards the trophectoderm lineage. Moreover, increased αKG levels promote blastoid polarization and trophectoderm maturation. αKG supplementation does not affect global histone methylation levels; rather, it decreases acetyl-CoA availability, reduces histone acetyltransferase activity and weakens the pluripotency network. We propose that metabolism functions as a positive feedback loop aiding in trophectoderm fate induction and maturation, highlighting that global metabolic rewiring can promote specificity in cell fate decisions through intricate regulation of signalling and chromatin.
Project description:Development and lineage choice are driven by interconnected transcriptional, epigenetic and metabolic changes. Specific metabolites, such as α-ketoglutarate (αKG), function as signalling molecules affecting the activity of chromatin-modifying enzymes. However, how metabolism coordinates cell-state changes, especially in human pre-implantation development, remains unclear. Here we uncover that inducing naive human embryonic stem cells towards the trophectoderm lineage results in considerable metabolic rewiring, characterized by αKG accumulation. Elevated αKG levels potentiate the capacity of naive embryonic stem cells to specify towards the trophectoderm lineage. Moreover, increased αKG levels promote blastoid polarization and trophectoderm maturation. αKG supplementation does not affect global histone methylation levels; rather, it decreases acetyl-CoA availability, reduces histone acetyltransferase activity and weakens the pluripotency network. We propose that metabolism functions as a positive feedback loop aiding in trophectoderm fate induction and maturation, highlighting that global metabolic rewiring can promote specificity in cell fate decisions through intricate regulation of signalling and chromatin.