Study reveals IDH1 enzyme's role in cardiac metabolic adaptation during cancer-related stress
Researchers discovered that isocitrate dehydrogenase 1 (IDH1) helps the heart adapt to metabolic stress caused by cancer-related mutations through a previously unknown reductive metabolic pathway. The study used stable isotope tracing and genetic knockout models in rat and mouse heart tissue to show that when mitochondrial metabolism is impaired, IDH1 redirects carbon flux toward glutamine-derived citrate formation. This finding expands understanding of how cardiac metabolism responds to oncometabolic stress and may have implications for managing cardiovascular complications in cancer patients.
A new preprint study published on bioRxiv reveals an unexpected metabolic adaptation mechanism in the heart in response to cancer-related stress. Researchers investigated how isocitrate dehydrogenase (IDH) mutations—common in cancer cells and associated with production of the oncometabolite D-2-hydroxyglutarate—affect cardiac function. Using stable isotope tracer studies combined with computational modeling in perfused rat hearts and cultured mouse cardiomyocytes, the team found that when mitochondrial metabolism becomes defective, the heart redirects metabolic carbon flux from oxidative toward reductive pathways. Specifically, they demonstrated that IDH1 catalyzes reductive carboxylation that increases glutamine uptake and glutamine-derived citrate formation. Genetic knockout experiments confirmed IDH1's critical role, as loss of IDH1 expression impaired both the reductive citrate formation and cardiomyocyte function. Additionally, epigenetic analyses revealed that IDH1 induces widespread alterations in histone acetylation and methylation, suggesting a link between cardiac metabolic adaptation and transcriptional control.
Limitations & open questions
The study's limitations include reliance on in vitro and ex vivo models (perfused hearts and cultured cardiomyocytes) rather than whole-organism studies, which may not fully capture systemic metabolic interactions. The relevance of these findings to human cardiac pathology in cancer patients remains to be established through clinical studies. Additionally, the functional consequences of the epigenetic modifications identified (histone acetylation and methylation changes) require further investigation to determine their role in long-term cardiac adaptation or dysfunction.
What different sources said
- bioRxivCenter
Reductive carboxylation via isocitrate dehydrogenase 1 supports cardiac metabolic adaptation during oncometabolic stress.
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