Abstract: TH-PO1092
Role of Pyruvate Kinase M2-Mediated Metabolic Reprogramming During Podocyte Differentiation
Session Information
- Glomerular Diseases: Podocyte Biology - I
November 07, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1204 Podocyte Biology
Authors
- Sun, Qi, Second Affiliated Hospital, Nanjing Medical University, Nanjing, JIANGSU , China
- Yang, Junwei, Second Affiliated Hospital, Nanjing Medical University, Nanjing, JIANGSU , China
Background
Podocyte, a type of highly specialized epithelial cells with sophisticated foot processes and unique slit diaphragm, requires substantial levels of energy to maintain its integrity and function, but little is known on the regulation of podocyte's energetics. Lack of metabolic analysis during podocyte development led us to explore the role of cellular metabolism and mitochondrial biology during in vitro differentiation.
Methods
To study the metabolic alterations caused by differentiation, nuclear magnetic resonance (NMR) spectroscopy was performed to analyze the metabolomic profiling of differentiated and un-differentiated cultured mouse podocytes. Cell metabolism was measured by seahorse XF analyzer. Mitotracker Red CMXRos and MitoProbe JC-1 Assay Kit were used to identify mitochondrial morphology, mass and membrane potential. Pkm2-RNAi-Lentivirus was used to explore the regulating role of PKM2 during podocyte differentiation.
Results
In this study, we observed a huge increase in mitochondrial biogenesis. Changes in mitochondrial mass, morphology and function were correlated with the upregulation of the master regulators of mitochondrial biogenesis, TFAM and PGC-1α. Unexpectedly, concomitant with mitochondrial biogenesis, we observed an increase in glycolysis during podocyte differentiation, which was linked to the overexpression of glycolic enzymes. Among them, PKM2 was of particular interest. The real-time quantitative PCR and PK activity assay kit showed both pyruvate kinase M2 (PKM2) expression and activity were upregulated. Knockdown of Pkm2 showed dramatic reduction of glycolysis and mitochondrial function, resulting in the defects of podocyte differentiation.
Conclusion
Usually, differentiated cells have repressed glycolysis, as they mostly rely on OXPHOS for energy demand. Our findings here first demonstrate that differentiated podocytes boost both glycolysis and mitochondrial metabolism to meet their augmented energy demand. We identified PKM2 as a critical regulator of energy metabolism in podocytes. Selective inhibition of PKM2 indicate existence of metabolic checkpoint that need to be satisfied in order to allow podocyte differentiation.
Funding
- Government Support - Non-U.S.