Podocyte-specific GLUT4-deficient mice have fewer and larger podocytes and are protected from diabetic nephropathy

TY - JOUR

T1 - Podocyte-specific GLUT4-deficient mice have fewer and larger podocytes and are protected from diabetic nephropathy

AU - Guzman, Johanna

AU - Jauregui, Alexandra N

AU - Merscher-Gomez, Sandra

AU - Maiguel, Dony

AU - Muresan, Cristina

AU - Mitrofanova, Alla

AU - Diez-Sampedro, Ana

AU - Szust, Joel

AU - Yoo, Tae-Hyun

AU - Villarreal, Rodrigo

AU - Pedigo, Christopher

AU - Molano, R Damaris

AU - Johnson, Kevin

AU - Kahn, Barbara

AU - Hartleben, Bjoern

AU - Huber, Tobias B

AU - Saha, Jharna

AU - Burke, George W

AU - Abel, E Dale

AU - Brosius, Frank C

AU - Fornoni, Alessia

PY - 2014/2

Y1 - 2014/2

N2 - Podocytes are a major component of the glomerular filtration barrier, and their ability to sense insulin is essential to prevent proteinuria. Here we identify the insulin downstream effector GLUT4 as a key modulator of podocyte function in diabetic nephropathy (DN). Mice with a podocyte-specific deletion of GLUT4 (G4 KO) did not develop albuminuria despite having larger and fewer podocytes than wild-type (WT) mice. Glomeruli from G4 KO mice were protected from diabetes-induced hypertrophy, mesangial expansion, and albuminuria and failed to activate the mammalian target of rapamycin (mTOR) pathway. In order to investigate whether the protection observed in G4 KO mice was due to the failure to activate mTOR, we used three independent in vivo experiments. G4 KO mice did not develop lipopolysaccharide-induced albuminuria, which requires mTOR activation. On the contrary, G4 KO mice as well as WT mice treated with the mTOR inhibitor rapamycin developed worse adriamycin-induced nephropathy than WT mice, consistent with the fact that adriamycin toxicity is augmented by mTOR inhibition. In summary, GLUT4 deficiency in podocytes affects podocyte nutrient sensing, results in fewer and larger cells, and protects mice from the development of DN. This is the first evidence that podocyte hypertrophy concomitant with podocytopenia may be associated with protection from proteinuria.

AB - Podocytes are a major component of the glomerular filtration barrier, and their ability to sense insulin is essential to prevent proteinuria. Here we identify the insulin downstream effector GLUT4 as a key modulator of podocyte function in diabetic nephropathy (DN). Mice with a podocyte-specific deletion of GLUT4 (G4 KO) did not develop albuminuria despite having larger and fewer podocytes than wild-type (WT) mice. Glomeruli from G4 KO mice were protected from diabetes-induced hypertrophy, mesangial expansion, and albuminuria and failed to activate the mammalian target of rapamycin (mTOR) pathway. In order to investigate whether the protection observed in G4 KO mice was due to the failure to activate mTOR, we used three independent in vivo experiments. G4 KO mice did not develop lipopolysaccharide-induced albuminuria, which requires mTOR activation. On the contrary, G4 KO mice as well as WT mice treated with the mTOR inhibitor rapamycin developed worse adriamycin-induced nephropathy than WT mice, consistent with the fact that adriamycin toxicity is augmented by mTOR inhibition. In summary, GLUT4 deficiency in podocytes affects podocyte nutrient sensing, results in fewer and larger cells, and protects mice from the development of DN. This is the first evidence that podocyte hypertrophy concomitant with podocytopenia may be associated with protection from proteinuria.

KW - Albuminuria

KW - Animals

KW - Cell Size

KW - Diabetic Nephropathies

KW - Doxorubicin

KW - Female

KW - Gene Expression Regulation

KW - Glomerular Filtration Barrier

KW - Glucose Transporter Type 1

KW - Glucose Transporter Type 4

KW - Lipopolysaccharides

KW - Mice

KW - Podocytes

KW - Journal Article

U2 - 10.2337/db13-0752

DO - 10.2337/db13-0752

M3 - SCORING: Journal article

C2 - 24101677

VL - 63

SP - 701

EP - 714

JO - DIABETES

JF - DIABETES

SN - 0012-1797

IS - 2

ER -