Linking Energy Metabolism to Cell Fate Decision During Kidney Development

Abstract

ObjectiveMetabolic flux switching accompanies cell fate changes in several organisms and cell types. We recently showed that glycolysis inhibition drives differentiation of nephron progenitor cell (NPC) in embryonic (E) kidney in organ culture experiments. We utilized a transcriptomics approach to uncover renewal vs differentiation genes in pathways targeted by glycolysis vs Wnt‐mediated differentiation, as canonical Wnt signaling is an established inducer of nephrogenesis.MethodsBulk RNASeq was performed on cultured NPCs isolated from E13.5 kidneys after 24h treatment with either the glycolysis inhibitor YN1 (20uM) or GSK3b inhibitor CHIR (3uM) to activate Wnt signaling. NPCs were isolated from 3 separate litters and pooled per litter. Differential expression (DE) thresholds: p‐value<0.05, fold‐change 0.6.We have also carried out organ culture experiments on E12.5 kidneys; paired kidneys were fixed after 24h Pravastatin (10uM) or vehicle treatment for immunostaining to identify NPCs (Six2+) or nascent nephrons (Lhx1+).ResultsCompared to renewing NPCs, approximately 550/15,300 genes were differentially expressed after CHIR or YN1 treatment, respectively. Pathway analysis revealed the common top over‐represented pathways as Cholesterol biosynthesis, Wnt and Calcium signaling. Fatty acid metabolism related pathways dominated in YN1‐treated NPCs and amino acid biosynthesis pathways in CHIR‐treated NPCs. Furthermore, to determine whether the inhibition of cholesterol biosynthesis is a requisite for nephrogenesis or a result of the differentiated state, E12.5 kidneys were treated with HMG‐CoA reductase inhibitor, Pravastatin, resulting in a significant increase in nephrogenesis marker staining (Lhx1+) and decrease in the self‐renewing progenitor pool (Six2+).ConclusionsOur data suggest glycolysis is required to maintain the cholesterol biosynthesis pathway and NPC self‐renewal and that the inhibition of either pathway directs the NPC toward differentiation.Support or Funding InformationThis work was supported by the National Institutes of Health: NIH/NIDDK R01 DK118231