Targeted deletion of kidney glucose-6 phosphatase leads to nephropathy

Kidney Int. 2014 Oct;86(4):747-56. doi: 10.1038/ki.2014.102. Epub 2014 Apr 9.

Abstract

Renal failure is a major complication that arises with aging in glycogen storage disease type 1a and type 1b patients. In the kidneys, glucose-6 phosphatase catalytic subunit (encoded by G6pc) deficiency leads to the accumulation of glycogen, an effect resulting in marked nephromegaly and progressive glomerular hyperperfusion and hyperfiltration preceding the development of microalbuminuria and proteinuria. To better understand the end-stage nephropathy in glycogen storage disease type 1a, we generated a novel kidney-specific G6pc knockout (K-G6pc(-/-)) mouse, which exhibited normal life expectancy. After 6 months, K-G6pc(-/-) mice showed glycogen overload leading to nephromegaly and tubular dilation. Moreover, renal accumulation of lipids due to activation of de novo lipogenesis was observed. This led to the activation of the renin-angiotensin system and the development of epithelial-mesenchymal transition process and podocyte injury by transforming growth factor β1 signaling. The K-G6pc(-/-) mice developed microalbuminuria caused by the impairment of the glomerular filtration barrier. Thus, renal G6pc deficiency alone is sufficient to induce the development of the early-onset nephropathy observed in glycogen storage disease type 1a, independent of the liver disease. The K-G6pc(-/-) mouse model is a unique tool to decipher the molecular mechanisms underlying renal failure and to evaluate potential therapeutic strategies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Albuminuria / etiology
  • Animals
  • Dilatation, Pathologic / etiology
  • Dilatation, Pathologic / pathology
  • Disease Models, Animal*
  • Epithelial-Mesenchymal Transition
  • Glomerular Filtration Barrier / physiopathology*
  • Glucose-6-Phosphatase / genetics*
  • Glycogen Storage Disease Type I / complications
  • Glycogen Storage Disease Type I / genetics*
  • Kidney Diseases / etiology
  • Kidney Diseases / metabolism
  • Kidney Diseases / pathology*
  • Kidney Tubules / pathology*
  • Lipid Metabolism
  • Male
  • Mice
  • Mice, Knockout
  • Podocytes / pathology
  • Renin-Angiotensin System
  • Signal Transduction
  • Transforming Growth Factor beta1 / metabolism

Substances

  • Transforming Growth Factor beta1
  • Glucose-6-Phosphatase