Abstract: FR-PO299
Primary Cilia Respond to Nutrients Availability and Favor Glutamine Utilization During Metabolic Stress
Session Information
- Genetic Diseases of the Kidneys: Cystic - II
November 04, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
Abstract Time: 10:00 AM - 12:00 PM
Category: Genetic Diseases of the Kidneys
- 1101 Genetic Diseases of the Kidneys: Cystic
Authors
- Steidl, Maria Elena, IRCCS Ospedale San Raffaele, Milano, Lombardia, Italy
- Nigro, Elisa Agnese, IRCCS Ospedale San Raffaele, Milano, Lombardia, Italy
- Nielsen, Anne Kallehauge, IRCCS Ospedale San Raffaele, Milano, Lombardia, Italy
- Lampis, Matteo, IRCCS Ospedale San Raffaele, Milano, Lombardia, Italy
- Cassina, Laura, IRCCS Ospedale San Raffaele, Milano, Lombardia, Italy
- Podrini, Christine, IRCCS Ospedale San Raffaele, Milano, Lombardia, Italy
- Pagliarini, Roberto, IRCCS Ospedale San Raffaele, Milano, Lombardia, Italy
- Chiaravalli, Marco, IRCCS Ospedale San Raffaele, Milano, Lombardia, Italy
- Mannella, Valeria, IRCCS Ospedale San Raffaele, Milano, Lombardia, Italy
- Yang, Ming, Exzellenzcluster CECAD in der Universitat zu Koln, Koln, Nordrhein-Westfalen, Germany
- Musco, Giovanna, IRCCS Ospedale San Raffaele, Milano, Lombardia, Italy
- Frezza, Christian, Exzellenzcluster CECAD in der Universitat zu Koln, Koln, Nordrhein-Westfalen, Germany
- Boletta, Alessandra, IRCCS Ospedale San Raffaele, Milano, Lombardia, Italy
Background
Autosomal Dominant Polycystic Kidney Disease (ADPKD) represents the most common renal ciliopathy. Our group demonstrated that ADPKD is characterized by a metabolic rewiring that involves increased glycolysis, glutaminolysis, fatty acid synthesis, and decreased oxidative phosphorylation (OXPHOS) and fatty acid oxidation. Given that the polycystins localize to cilia, but also to other locations, we wondered what is the contribution (if any) of cilia in regulation of the bioenergetic demand of cells.
Methods
Cilium-ablated Ift88 KO MEFs and IMCD3 cells were generated by CRISPR/Cas9 technology. NMR and LC-MS analyses were used to measure extracellular and intracellular metabolites. Seahorse assays were performed to measure mitochondrial respiration parameters. Immunofluorescence analyses were performed to measure primary cilium length both in vitro and in vivo in response to various nutrients.
Results
We found that cilium-ablated cells do not display overt differences compared to controls in cellular growth or mitochondrial respiration under complete medium conditions. However, NMR and LC-MS metabolomics under the same culture conditions revealed subtle differences between cilium-ablated cells and controls in metabolites involved in glucose and glutamine-related pathways and in the TCA cycle. Interestingly, we found that nutrients deprivation drives a drastic primary cilium elongation, with an effect much stronger than simple serum deprivation. Physiological levels of glutamine, but not glucose, caused re-shortening of cilia both in vitro and in vivo. Furthermore, when exposed to glutamine supplementation under nutrients deprivation, cilium-ablated cells display significant abnormalities in the intracellular levels of glutamine, aspartate, and asparagine, suggesting an altered glutamine utilization under metabolic stress. We also found that this effect was mTOR-independent, but likely mediated by glutamine fueling of the TCA cycle.
Conclusion
Our results reveal that the primary cilium is involved in the response to nutrients availability and the usage of glutamine. These important findings could shed light on the role of primary cilium both in physiological and pathological contexts.