Delayed mTOR inhibition with low dose of everolimus reduces TGFβ expression, attenuates proteinuria and renal damage in the renal mass reduction model

The immunosuppressive mammalian target of rapamycin (mTOR) inhibitors are widely used in solid organ transplantation, but their effect on kidney disease progression is controversial. mTOR has emerged as one of the main pathways regulating cell growth, proliferation, differentiation, migration, and survival. The aim of this study was to analyze the effects of delayed inhibition of mTOR pathway with low dose of everolimus on progression of renal disease and TGFβ expression in the 5/6 nephrectomy model in Wistar rats

Delayed mTOR inhibition with low dose of everolimus reduces TGFβ expression, attenuates proteinuria and renal damage in the renal mass reduction model

The immunosuppressive mammalian target of rapamycin (mTOR) inhibitors are widely used in solid organ transplantation, but their effect on kidney disease progression is controversial. mTOR has emerged as one of the main pathways regulating cell growth, proliferation, differentiation, migration, and survival. The aim of this study was to analyze the effects of delayed inhibition of mTOR pathway with low dose of everolimus on progression of renal disease and TGFβ expression in the 5/6 nephrectomy model in Wistar rats

Morphometric analysis of glomerular hypertrophy and kidney fibrosis.

<p>Panel A. Representative images from histological sections stained with Sirius red: Sham Group (A), Control Group (B) and Everolimus Group (C) (magnification 200×). Panel B. Glomerular area (media and SD) and frequency distribution diagram of glomerular area. Panel C. Mesangial fibrosis area (mean and SD) and frequency distribution diagram of mesangial fibrosis area in the three groups. Panel D. Tubulointerstitial fibrosis area (mean and SD) and frequency distribution diagram of tubulointerstitial fibrosis area in the three groups. * p<0.05 vs sham group and †p<0.05 vs control group.</p

Immunohistochemistry: fibrosis, cell proliferation and inflamation.

<p>Representative results from the different groups are shown: Sham Group (A,D,G,J), Control Group (B,E,H,K) and Everolimus Group (C,F,I,L). PAS tinction (A,B,C) (magnification 200×), Immunohistochemistry for α smooth muscle actin (200×) (D,E, F), Glomerular and tubulointerstitial proliferating cell nuclear antigen (PCNA) immunostaining (200×) (G,H,I) and anti CD68 (400×) (J,K,L). Sections were counterstained with eosin.</p

Western blot and protein abundance ratio for pAkt/tAkt and pERK/tERK.

<p>A) Inmunoblotting analysis for Total Akt 1–2 and phospho-Akt (Ser473); B) Densitometric analysis of pAkt/total Akt: SG (n = 7), CG (n = 5) and EveG (n = 6); C) Inmunoblotting analysis for ERK 1/2 and p-ERK (E-4), D) Densitometric analysis of pERK/total ERK. SG (n = 7), CG (n = 5) and EveG (n = 6). * p<0.05 vs sham group.</p

mRNA expression for Akt, mTOR and TGF β.

<p>Relative mRNA expression levels of Akt, mTOR and TGF β were assessed by real time quantitative reverse transcriptase-PCR in remnant kidneys of SG (n = 7), CG (n = 5) and EveG (n = 7). *p<0.05 vs sham, **p<0.05 vs CG.</p

Weight, blood pressure, renal function, proteinuria and microalbuminuria from animals at week 8 of treatment.

<p>Weight, blood pressure, renal function, proteinuria and microalbuminuria from animals at week 8 of treatment.</p

Histological and immunohistochemistry semiquantitative analysis.

<p>Histological and immunohistochemistry semiquantitative analysis.</p