Disease Models & Mechanisms (Nov 2020)

Teleological role of L-2-hydroxyglutarate dehydrogenase in the kidney

  • Garrett Brinkley,
  • Hyeyoung Nam,
  • Eunhee Shim,
  • Richard Kirkman,
  • Anirban Kundu,
  • Suman Karki,
  • Yasaman Heidarian,
  • Jason M. Tennessen,
  • Juan Liu,
  • Jason W. Locasale,
  • Tao Guo,
  • Shi Wei,
  • Jennifer Gordetsky,
  • Teresa L. Johnson-Pais,
  • Devin Absher,
  • Dinesh Rakheja,
  • Anil K. Challa,
  • Sunil Sudarshan

DOI
https://doi.org/10.1242/dmm.045898
Journal volume & issue
Vol. 13, no. 11

Abstract

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L-2-hydroxyglutarate (L-2HG) is an oncometabolite found elevated in renal tumors. However, this molecule might have physiological roles that extend beyond its association with cancer, as L-2HG levels are elevated in response to hypoxia and during Drosophila larval development. L-2HG is known to be metabolized by L-2HG dehydrogenase (L2HGDH), and loss of L2HGDH leads to elevated L-2HG levels. Despite L2HGDH being highly expressed in the kidney, its role in renal metabolism has not been explored. Here, we report our findings utilizing a novel CRISPR/Cas9 murine knockout model, with a specific focus on the role of L2HGDH in the kidney. Histologically, L2hgdh knockout kidneys have no demonstrable histologic abnormalities. However, GC-MS metabolomics demonstrates significantly reduced levels of the TCA cycle intermediate succinate in multiple tissues. Isotope labeling studies with [U-13C] glucose demonstrate that restoration of L2HGDH in renal cancer cells (which lowers L-2HG) leads to enhanced incorporation of label into TCA cycle intermediates. Subsequent biochemical studies demonstrate that L-2HG can inhibit the TCA cycle enzyme α-ketoglutarate dehydrogenase. Bioinformatic analysis of mRNA expression data from renal tumors demonstrates that L2HGDH is co-expressed with genes encoding TCA cycle enzymes as well as the gene encoding the transcription factor PGC-1α, which is known to regulate mitochondrial metabolism. Restoration of PGC-1α in renal tumor cells results in increased L2HGDH expression with a concomitant reduction in L-2HG levels. Collectively, our analyses provide new insight into the physiological role of L2HGDH as well as mechanisms that promote L-2HG accumulation in disease states.

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