The locally activated renin-angiotensin system is involved in albumin permeability in glomerular endothelial cells under high glucose conditions

© The Author 2016. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved..

Background: Although the diabetic milieu per se , hemodynamic changes, oxidative stress and local growth factors such as angiotensin II (AII) are considered to be mediators in the pathogenesis of diabetic nephropathy, the underlying pathways mediating the changes in glomerular endothelial cells (GECs) are not well understood. Therefore, we investigated changes in the renin-angiotensin system (RAS) components in high glucose (HG)-stimulated GECs and the role of the local RAS in morphological and functional changes in GECs under diabetic conditions.

Methods: We stimulated GECs with 5.6 mM glucose or 30 mM glucose with or without an angiotensin II type I receptor blocker (ARB) in vitro and also performed experiments with Sprague-Dawley rats injected with diluent ( n = 16) or streptozotocin [ n = 16, diabetes (DM)]. Eight rats from each group were treated with ARB for 3 months in vivo . Real-time polymerase chain reaction, western blot analysis, enzyme-linked immunosorbent assay and immunofluorescent staining using cultured GECs were performed. The permeability of GECs to macromolecules was assessed by measuring the passage of fluorescein isothiocyanate-labeled bovine serum albumin. Morphological changes were also evaluated by scanning and transmission electron microscopy.

Results: There were significant increases in angiotensinogen expression in HG-stimulated GECs along with significant increases in AI and AII levels. Moreover, the expression of heparan sulfate glycosaminoglycans (HS-GAG) assessed by immunofluorescent staining was significantly lower and the permeability to albumin was significantly higher in GECs exposed to HG medium, and ARB treatment significantly abrogated these changes. Upon electron microscopy examination, the mean size of the GEC fenestrae was significantly greater in HG-stimulated GECs and DM rats, and these increases were significantly ameliorated by ARB.

Conclusions: The local RAS within GECs was activated under HG conditions, and this activation may be associated with both an alteration in GEC fenestration and a decrease in HS-GAG, resulting in the development of albuminuria in diabetic nephropathy.

Medienart:

E-Artikel

Erscheinungsjahr:

2017

Erschienen:

2017

Enthalten in:

Zur Gesamtaufnahme - volume:32

Enthalten in:

Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association - 32(2017), 1 vom: 01. Jan., Seite 61-72

Sprache:

Englisch

Beteiligte Personen:

Paeng, Jisun [VerfasserIn]
Park, Jimin [VerfasserIn]
Um, Jae Eun [VerfasserIn]
Nam, Bo Young [VerfasserIn]
Kang, Hye-Young [VerfasserIn]
Kim, Seonghun [VerfasserIn]
Oh, Hyung Jung [VerfasserIn]
Park, Jung Tak [VerfasserIn]
Han, Seung Hyeok [VerfasserIn]
Ryu, Dong-Ryeol [VerfasserIn]
Yoo, Tae-Hyun [VerfasserIn]
Kang, Shin-Wook [VerfasserIn]

Links:

Volltext

Themen:

11002-13-4
11128-99-7
Albumins
Albuminuria
Angiotensin II
Angiotensinogen
Diabetic nephropathy
Fenestrae
Glomerular endothelial cells
Glucose
IY9XDZ35W2
Journal Article
Receptor, Angiotensin, Type 1
Renin-angiotensin system
Sweetening Agents

Anmerkungen:

Date Completed 26.09.2017

Date Revised 02.12.2018

published: Print

Citation Status MEDLINE

doi:

10.1093/ndt/gfw089

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM261894366