1. Hyperactive HRAS dysregulates energetic metabolism in fibroblasts from patients with Costello syndrome via enhanced production of reactive oxidizing species
- Author
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Laura Mercurio, Francesca Megiorni, Chiara Leoni, Daniele Pietrucci, Teresa Rizza, Egidio Iorio, Giuseppe Zampino, Giovanna Carpentieri, Massimo Tatti, Simona Camero, Serena Cecchetti, Elisabetta Flex, Roberta Onesimo, Giovanni Chillemi, Cinzia Marchese, Valentina Tirelli, Donatella Pietraforte, Rosalba Carrozzo, Sara Rinalducci, Michela Di Nottia, Deborah Pajalunga, Antonio Belardo, and Marco Tartaglia
- Subjects
Fibroblasts ,humans ,oxidation-reduction ,Phosphatidylinositol 3-kinases ,proto-oncogene proteins p21(ras) ,signal transduction ,Costello syndrome ,Biology ,Proto-Oncogene Proteins p21(ras) ,Wortmannin ,Phosphatidylinositol 3-Kinases ,chemistry.chemical_compound ,Lipid droplet ,Genetics ,medicine ,Humans ,Glycolysis ,HRAS ,Molecular Biology ,Genetics (clinical) ,Costello Syndrome ,Glucose transporter ,General Medicine ,medicine.disease ,Cell biology ,chemistry ,biology.protein ,Oxidation-Reduction ,Flux (metabolism) ,GLUT4 ,Signal Transduction - Abstract
Germline-activating mutations in HRAS cause Costello syndrome (CS), a cancer prone multisystem disorder characterized by reduced postnatal growth. In CS, poor weight gain and growth are not caused by low caloric intake. Here, we show that constitutive plasma membrane translocation and activation of the GLUT4 glucose transporter, via reactive oxygen species-dependent AMP-activated protein kinase α and p38 hyperactivation, occurs in primary fibroblasts of CS patients, resulting in accelerated glycolysis and increased fatty acid synthesis and storage as lipid droplets. An accelerated autophagic flux was also identified as contributing to the increased energetic expenditure in CS. Concomitant inhibition of p38 and PI3K signaling by wortmannin was able to rescue both the dysregulated glucose intake and accelerated autophagic flux. Our findings provide a mechanistic link between upregulated HRAS function, defective growth and increased resting energetic expenditure in CS, and document that targeting p38 and PI3K signaling is able to revert this metabolic dysfunction.
- Published
- 2021