MilliporeSigma

Gq signaling causes glomerular injury by activating TRPC6.

The Journal of clinical investigation (2015-04-07)
Liming Wang, Grant Jirka, Paul B Rosenberg, Anne F Buckley, Jose A Gomez, Timothy A Fields, Michelle P Winn, Robert F Spurney
ABSTRACT

Familial forms of focal segmental glomerulosclerosis (FSGS) have been linked to gain-of-function mutations in the gene encoding the transient receptor potential channel C6 (TRPC6). GPCRs coupled to Gq signaling activate TRPC6, suggesting that Gq-dependent TRPC6 activation underlies glomerular diseases. Here, we developed a murine model in which a constitutively active Gq α subunit (Gq(Q209L), referred to herein as GqQ>L) is specifically expressed in podocytes and examined the effects of this mutation in response to puromycin aminonucleoside (PAN) nephrosis. We found that compared with control animals, animals expressing GqQ>L exhibited robust albuminuria, structural features of FSGS, and reduced numbers of glomerular podocytes. Gq activation stimulated calcineurin (CN) activity, resulting in CN-dependent upregulation of TRPC6 in murine kidneys. Deletion of TRPC6 in GqQ>L-expressing mice prevented FSGS development and inhibited both tubular damage and podocyte loss induced by PAN nephrosis. Similarly, administration of the CN inhibitor FK506 reduced proteinuria and tubular injury but had more modest effects on glomerular pathology and podocyte numbers in animals with constitutive Gq activation. Moreover, these Gq-dependent effects on podocyte injury were generalizable to diabetic kidney disease, as expression of GqQ>L promoted albuminuria, mesangial expansion, and increased glomerular basement membrane width in diabetic mice. Together, these results suggest that targeting Gq/TRPC6 signaling may have therapeutic benefits for the treatment of glomerular diseases.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Anti-Actin Antibody, clone C4, clone C4, Chemicon®, from mouse
Sigma-Aldrich
Ethylenediaminetetraacetic acid, BioUltra, anhydrous, ≥99% (titration)
Sigma-Aldrich
Ethylenediaminetetraacetic acid, purified grade, ≥98.5%, powder
Sigma-Aldrich
Ethylenediaminetetraacetic acid, anhydrous, crystalline, BioReagent, suitable for cell culture
Sigma-Aldrich
Ethylenediaminetetraacetic acid, ACS reagent, 99.4-100.6%, powder
Sigma-Aldrich
Ethylenediaminetetraacetic acid solution, 0.02% in DPBS (0.5 mM), sterile-filtered, BioReagent, suitable for cell culture
Sigma-Aldrich
Creatinine, anhydrous, ≥98%
Sigma-Aldrich
Allene, ≥95%
Sigma-Aldrich
Ethylenediaminetetraacetic acid, 99.995% trace metals basis
Sigma-Aldrich
Sodium chloride solution, 0.85%
Sigma-Aldrich
BIS-TRIS, BioXtra, ≥98.0% (titration)
Sigma-Aldrich
BIS-TRIS, ≥98.0% (titration)
Sigma-Aldrich
Doxorubicin hydrochloride, 98.0-102.0% (HPLC)
Sigma-Aldrich
Sodium chloride solution, 5 M
Sigma-Aldrich
Sodium chloride solution, 5 M in H2O, BioReagent, for molecular biology, suitable for cell culture
Sigma-Aldrich
BIS-TRIS, BioPerformance Certified, suitable for cell culture, suitable for insect cell culture, ≥98.0%
Sigma-Aldrich
Sodium chloride, 99.999% trace metals basis
Sigma-Aldrich
Sodium chloride, AnhydroBeads, −10 mesh, 99.999% trace metals basis
Sigma-Aldrich
Sodium chloride, AnhydroBeads, −10 mesh, 99.99% trace metals basis
Sigma-Aldrich
Sodium chloride, random crystals, optical grade, 99.9% trace metals basis
Sigma-Aldrich
Sodium chloride-35Cl, 99 atom % 35Cl
Sigma-Aldrich
Sodium chloride, BioUltra, for molecular biology, ≥99.5% (AT)
Sigma-Aldrich
BIS-TRIS, BioUltra, ≥99.0% (NT)
Sigma-Aldrich
Sodium chloride solution, BioUltra, for molecular biology, ~5 M in H2O
Sigma-Aldrich
Doxorubicin hydrochloride, suitable for fluorescence, 98.0-102.0% (HPLC)
Sigma-Aldrich
Sodium chloride, meets analytical specification of Ph. Eur., BP, USP, 99.0-100.5%
Sigma-Aldrich
Sodium chloride, for molecular biology, DNase, RNase, and protease, none detected, ≥99% (titration)
Sigma-Aldrich
Sodium chloride, BioReagent, suitable for cell culture, suitable for insect cell culture, suitable for plant cell culture, ≥99%
Sigma-Aldrich
Sodium chloride solution, 0.9% in water, BioXtra, suitable for cell culture
Sigma-Aldrich
Sodium chloride, BioXtra, ≥99.5% (AT)