Retinoic acid reduces glomerular injury in a rat model of glomerular damage.
ABSTRACT.: In the reaction of kidneys to injury, cytokine-driven proliferation plays an important role and precedes the development of glomerulosclerosis. There is great interest in agents that may interfere with such proliferation. Therefore, a rat model of mesangioproliferative glomerulonephritis (induced by anti-Thy1.1) was studied, and the effects of all-trans-retinoic acid (all-trans-RA) and isotretinoin, powerful antiproliferative and anti-inflammatory substances, on glomerular damage and cell proliferation were examined. Vehicle-injected control rats were compared with rats treated with daily subcutaneous injections of 10 mg/kg body wt all-trans-RA or 40 mg/kg body wt isotretinoin (n = 9 to 11 per group), using either a pretreatment (days -2 through 8) or posttreatment (days +3 through +8) protocol, i.e., starting before or after the induction of anti-Thy1.1 nephritis, respectively. All-trans-RA prevented the BP increase evoked by anti-Thy1.1 (anti-Thy1.1/vehicle, 112.2 +/- 4.8 mmHg; anti-Thy1.1/RA, 87.5 +/- 2. 5 mmHg; P < 0.001). Treatment with all-trans-RA or isotretinoin produced a 70% decrease in the urinary albumin excretion rate (P < 0. 02). Periodic acid-Schiff staining of saline-perfused kidneys (day 8) revealed significantly fewer glomerular cells in RA-treated nephritic rats (anti-Thy1.1/vehicle, 97 +/- 3.1 cells/glomerulus; anti-Thy1.1/RA, 80 +/- 4.4; P < 0.02; control/vehicle, 69 +/- 1.2). No difference was observed between all-trans-RA and isotretinoin treatment. The capillary occlusion scores were significantly lower for the anti-Thy1.1/RA-treated group (1.9 +/- 0.1) than for the anti-Thy1.1/vehicle-treated group (2.9 +/- 0.5, P < 0.001). In the anti-Thy1.1/vehicle-treated group, 11.9 +/- 1.1 glomerular cells were proliferating cell nuclear antigen-positive; however, in the anti-Thy1.1/RA-treated group, only 5.3 +/- 0.8 cells were proliferating cell nuclear antigen-positive (P < 0.002; control, 2.2 +/- 0.2). Glomerular mitoses were reduced by 67% in the anti-Thy1. 1/RA-treated group, compared with the anti-Thy1.1/control group (P < 0.002). Glomerular staining for platelet-derived growth factor B-chain was significantly reduced in anti-Thy1.1-treated nephritic rats in the presence of isotretinoin or all-trans-RA, compared with the vehicle-treated group (P < 0.001). It is concluded that all-trans-RA limits glomerular proliferation, glomerular lesions, and albuminuria in an established model of renal damage. The findings point to retinoids as potential novel modulators of glomerular injury.
Wagner
Jürgen
J
Department of Nephrology, University of Heidelberg, Heidelberg, Germany.
Dechow
Claudius
C
Department of Nephrology, University of Heidelberg, Heidelberg, Germany.
Morath
Christian
C
Department of Nephrology, University of Heidelberg, Heidelberg, Germany.
Lehrke
Ingo
I
Department of Nephrology, University of Heidelberg, Heidelberg, Germany.
Amann
Kerstin
K
Department of Pathology, University of Heidelberg, Heidelberg, Germany.
Waldherr
Rüdiger
R
Department of Nephrology, University of Heidelberg, Heidelberg, Germany.
Floege
Jürgen
J
Department of Nephrology, University of Hannover, Hannover, Germany.
Ritz
Eberhard
E
Department of Nephrology, University of Heidelberg, Heidelberg, Germany.
D000419:Albuminuria / Q000652:urine; D000818:Animals; D001794:Blood Pressure; D002452:Cell Count / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D015432:Glomerulonephritis, Membranoproliferative / Q000473:pathology* / Q000652:urine; D015474:Isotretinoin / Q000494:pharmacology*; D007668:Kidney / Q000187:drug effects / Q000473:pathology; D007678:Kidney Glomerulus / Q000187:drug effects* / Q000473:pathology*; D008264:Macrophages / Q000473:pathology; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D014212:Tretinoin / Q000494:pharmacology*
D014212:Tretinoin; D015474:Isotretinoin