Carnitine Palmitoyltransferase 1 facilitates fatty acid oxidation in a noncell autonomous manner [CPT1a_RNAseq]
Ontology highlight
ABSTRACT: Mitochondrial fatty acid oxidation is facilitated by the combined activities of Carnitine Palmitoyltransferase 1 and Carnitine Palmitoyltransferase 2 which generate and utilize acylcarnitines respectively. We compared the response of mice with liver specific deficiencies in the liver enriched Cpt1a or the ubiquitous Cpt2 and discovered that they display unique metabolic, physiological and molecular phenotypes. The loss of Cpt1a or Cpt2 resulted in the induction of the muscle enriched isoenzyme, Cpt1b, in hepatocytes in a Ppara dependent manner. Primary component analysis also revealed overall differential grouping between mouse with deletions of either Cpt1a or Cpt2. Our results utilize stringent genetic mouse models to elucidate that the sequential steps to facilitate mitochondrial fatty acid oxidation may have other factors.
Project description:Mitochondrial fatty acid oxidation is facilitated by the combined activities of Carnitine Palmitoyltransferase 1 and Carnitine Palmitoyltransferase 2 which generate and utilize acylcarnitines respectively. We compared the response of mice with liver specific deficiencies in Cpt1a and Cpt1b, Cpt2, or the triple deletion of all three acyltransferases. We discovered that they display unique metabolic, physiological and molecular phenotypes. The loss of Cpt1a and Cpt1b or Cpt2 resulted in particular transcriptional outputs in hepatocytes. We show that much of the transcriptional signature is suppressed when deleting both Cpt2 and Ppara, showing the contribution of Ppara. Our results utilize stringent genetic mouse models to characterize the differential phenotypes of mice lacking Cpt1a and Cpt1b or Cpt2 and also show the contribution of a major transcription factor, Ppara.
Project description:Analysis of skeletal muscle satellite cells with specific knockout (KO) of Carnitine Palmitoyltransferase 2 (Cpt2) gene in mouse (named Cpt2PKO). Cpt2 knockout disrupts fatty acid oxidation in satellite cells and causes energy insufficiency and alteration of protein acetylation, which eventually impedes their expansion and differentiation, leading to impairments in muscle regeneration.
Project description:Mitochondrial fatty acid oxidation (FAO) is an important energy provider for cardiac work and changes in cardiac substrate preference are associated with different heart diseases. Carnitine palmitoyltransferase 1B (CPT1B) is thought to perform the rate limiting enzyme step in FAO and is inhibited by malonyl-CoA. The role of CPT1B in cardiac metabolism has been addressed by inhibiting or decreasing CPT1B protein or after modulation of tissue malonyl-CoA metabolism. We assessed the role of CPT1B malonyl-CoA sensitivity in cardiac metabolism.
Project description:Carnitine palmitoyltransferase 1a (CPT1a) is the key regulator of mitochondrial long-chain fatty acid beta-oxidation (LCFAO). However, the functional significance of AT2 cell-specific LCFAO at baseline and during acute lung injury (ALI) is not fully understood. In this study, Murine models of AT2 cell-specific Cpt1a deletion were generated for investigating the role of CPT1a in regulating AT2 cell function and the severity of lipopolysaccharide-induced murine ALI models.
Project description:Carnitine palmitoyltransferase 1a (CPT1a) is the key regulator of mitochondrial long-chain fatty acid beta-oxidation (LCFAO). However, the functional significance of AT2 cell-specific LCFAO at baseline and during acute lung injury (ALI) is not fully understood. In this study, Murine models of AT2 cell-specific Cpt1a deletion were generated for investigating the role of CPT1a in regulating AT2 cell function and the severity of lipopolysaccharide-induced murine ALI models.
Project description:The liver is critical for maintaining systemic energy balance during starvation. To understand the role of hepatic fatty acid β-oxidation on this process, we generated mice with a liver-specific knockout of carnitine palmitoyltransferase 2 (Cpt2L-/-), an obligate step in mitochondrial long-chain fatty acid β-oxidation. Surprisingly, Cpt2L-/- mice survived the perinatal period and a 24hr fast with sufficient blood glucose. The loss of hepatic fatty acid oxidation resulted in a significant loss in circulating ketones that remained unaltered by fasting. Fasting induced serum dyslipidemia, hepatic steatosis and adaptations in hepatic and systemic oxidative gene expression in Cpt2L-/- mice to maintain systemic energy homeostasis. Alternatively, feeding a ketogenic diet resulted in severe hepatomegaly, liver damage and death within one week with a complete absence of adipose triglyceride stores. These data show that hepatic fatty acid oxidation is not required for survival during acute food deprivation but essential for constraining adipocyte lipolysis and regulating systemic catabolism when glucose is limiting. In this dataset, we include the expression data obtained from dissected mouse liver from mice fasted for 24 hours with and without the deletion of carnitine palmitoyltransferase 2 (i.e. hepatocytes unable to beta-oxidize long chain fatty acids in mitochondria). WildType and KnockOut mice were fasted for 24 hours. Three biologic replicates were compared per class, thus six mice.
Project description:Adult hippocampal neurogenesis is important for certain forms of cognition and failing neurogenesis has been implicated in neuropsychiatric diseases. The neurogenic capacity of hippocampal neural stem/progenitor cells (NSPCs) depends on a balance between quiescent and proliferative states. However, how this balance is regulated remains poorly understood. Here we show that the rate of fatty acid oxidation (FAO) defines quiescence vs. proliferation in NSPCs. Quiescent NSPCs show high levels of carnitine palmitoyltransferase 1a (Cpt1a)-dependent FAO, which is downregulated in proliferating NSPCs. Pharmacological inhibition and conditional deletion of Cpt1a in vitro and in vivo leads to altered NSPC behavior, showing that Cpt1a-dependent FAO is required for stem cell maintenance and proper neurogenesis. Strikingly, experimental manipulation of malonyl-CoA, the metabolite that regulates levels of FAO, is sufficient to induce exit from quiescence and to enhance NSPC proliferation. Thus, the data presented here identify a shift in FAO metabolism that governs NSPC behavior and suggest an instructive role for fatty acid metabolism in regulating NSPC activity.
Project description:Mitochondria are dynamic organelles that are important for cell growth and proliferation. Dysregulated mitochondrial dynamics are highly associated with the initiation and progression of various cancers, including ovarian cancer. However, the regulatory mechanism underlying mitochondrial dynamics is still not fully understood. Previously, our study showed that carnitine palmitoyltransferase 1A (CPT1A) is highly expressed in ovarian cancer cells and promotes the development of ovarian cancer. Here, we find that CPT1A regulates mitochondrial dynamics and promotes mitochondrial fission in ovarian cancer cells. Our study futher shows that CPT1A regulates mitochondrial fission and function through mitochondrial fission factor (MFF) to promote the growth and proliferation of ovarian cancer cells. Mechanistically, we show that CPT1A promotes succinylation of MFF at lysine 302 (K302), which protects against Parkin-mediated ubiquitin-proteasomal degradation of MFF. Finally, the study shows that MFF is highly expressed in ovarian cancer cells and that high MFF expression is associated with poor prognosis in patients with ovarian cancer. MFF inhibition significantly inhibits the progression of ovarian cancer in vivo. Overall, CPT1A regulates mitochondrial dynamics through MFF succinylation to promote the development of ovarian cancer. Moreover, our findings suggest that MFF is a potential therapeutic target for ovarian cancer.