Suppression of Rapidly Progressive Mouse Glomerulonephritis with the Non-Steroidal Mineralocorticoid Receptor Antagonist BR-4628 - PubMed (original) (raw)

Suppression of Rapidly Progressive Mouse Glomerulonephritis with the Non-Steroidal Mineralocorticoid Receptor Antagonist BR-4628

Frank Y Ma et al. PLoS One. 2015.

Abstract

Background/aim: Steroidal mineralocorticoid receptor antagonists (MRAs) are effective in the treatment of kidney disease; however, the side effect of hyperkalaemia, particularly in the context of renal impairment, is a major limitation to their clinical use. Recently developed non-steroidal MRAs have distinct characteristics suggesting that they may be superior to steroidal MRAs. Therefore, we explored the benefits of a non-steroidal MRA in a model of rapidly progressive glomerulonephritis.

Methods: Accelerated anti-glomerular basement membrane (GBM) glomerulonephritis was induced in groups of C57BL/6J mice which received no treatment, vehicle or a non-steroidal MRA (BR-4628, 5mg/kg/bid) from day 0 until being killed on day 15 of disease. Mice were examined for renal injury.

Results: Mice with anti-GBM glomerulonephritis which received no treatment or vehicle developed similar disease with severe albuminuria, impaired renal function, glomerular tuft damage and crescents in 40% of glomeruli. In comparison, mice which received BR-4628 displayed similar albuminuria, but had improved renal function, reduced severity of glomerular tuft lesions and a 50% reduction in crescents. The protection seen in BR-4628 treated mice was associated with a marked reduction in glomerular macrophages and T-cells and reduced kidney gene expression of proinflammatory (CCL2, TNF-α, IFN-γ) and profibrotic molecules (collagen I, fibronectin). In addition, treatment with BR-4626 did not cause hyperkalaemia or increase urine Na+/K+ excretion (a marker of tubular dysfunction).

Conclusions: The non-steroidal MRA (BR-4628) provided substantial suppression of mouse crescentic glomerulonephritis without causing tubular dysfunction. This finding warrants further investigation of non-steroidal MRAs as a therapy for inflammatory kidney diseases.

PubMed Disclaimer

Conflict of interest statement

Competing Interests: The authors have read the journal's policy and have the following competing interests: PK is an employee of Bayer Healthcare and is involved in Bayer's development of non-steroidal mineralocorticoid receptor antagonists for clinical use. This did not alter the authors' adherence to PLOS ONE policies on sharing data and materials.

Figures

Fig 1

Fig 1. BR-4628 protects mice from loss of renal function in anti-GBM glomerulonephritis.

(A) Compared to normal control (NC) mice given vehicle (red unfilled squares) or BR-4628 (blue unfilled triangles), urine albumin excretion was massively increased at days 1, 7 and 14 of glomerulonephritis (GN) in mice receiving no treatment (No Tx, black filled circles) or vehicle (red filled squares), and these albuminuria levels were unaffected by treatment with BR-4628 (blue filled triangles). (B) At day 15 of glomerulonephritis, there was a 6-fold increase in serum levels of cystatin-C in mice receiving no treatment or vehicle, which was reduced by 30% in mice treated with BR-4628. Data = mean ± SEM; n = 8. ***p<0.001.

Fig 2

Fig 2. BR-4628 reduces glomerular lesions in anti-GBM glomerulonephritis.

Histological staining with PAS and hematoxylin shows the kidney structure of (A) a normal mouse. In comparison, there is severe damage to glomeruli (capillary thrombosis, glomerulosclerosis, crescent formation) at day 15 of glomerulonephritis in (B) a mouse receiving no treatment and (C) a mouse receiving vehicle, which is attenuated in (D) a mouse treated with BR-4628. Graphs show (E) the severity score of glomerular tuft damage (0–4+) and (F) the percentage of glomeruli with crescents in kidneys from normal control (NC) mice and mice with glomerulonephritis (GN) receiving no treatment (No Tx), vehicle or BR-4628. Magnification: (A-D) x400. Graph Data = mean ± SEM; n = 8. *p<0.05, ***p<0.001, NS = not significant.

Fig 3

Fig 3. BR-4628 reduces tubular damage in anti-GBM glomerulonephritis.

Histological staining with PAS and hematoxylin shows the structure of kidney tubules in (A) a normal mouse. In comparison, there is severe damage to tubules (dilation, atrophy, cell loss) at day 15 of glomerulonephritis in (B) a mouse receiving no treatment and (C) a mouse receiving vehicle, which is attenuated in (D) a mouse treated with BR-4628. Graphs show (E) the number of activated caspase-3+ apoptotic cells in tubules in the kidney cortex and (F) the gene expression of kidney injury molecule-1 (KIM-1) in kidneys from normal control (NC) mice and mice with glomerulonephritis (GN) receiving no treatment (No Tx), vehicle or BR-4628. Magnification: (A-D) x400. Graph Data = mean ± SEM; n = 8. *p<0.05, ***p<0.001, NS = not significant.

Fig 4

Fig 4. BR-4628 reduces kidney gene expression of pro-fibrotic molecules in anti-GBM glomerulonephritis.

RT-PCR analysis showed that in comparison to normal control (NC) mice, there was a marked increase in the kidney mRNA levels of (A) collagen 1 (α1 chain), (B) fibronectin and (C) TGF-β1 at day 15 of glomerulonephritis in mice receiving no treatment (No Tx), which was similar to mice receiving vehicle. Treatment with BR-4628 reduced the kidney mRNA level of each of these profibrotic molecules. Data = mean ± SEM; n = 8. **p<0.01, ***p<0.001, NS = not significant.

Fig 5

Fig 5. BR-4628 reduces inflammation in anti-GBM glomerulonephritis.

Immunostaining of a CD68+ macrophage (brown) was seen in a minor proportion of (A) the glomeruli of normal control (NC) mice. In comparison, there was substantial accumulation of CD68+ macrophages in mice with glomerulonephritis receiving (B) no treatment or (C) vehicle, which was reduced in (D) mice receiving BR-4628. Quantification of immunostaining of (E) glomerular CD68+ macrophages and (F) glomerular CD3+ T-cells show that there was a marked increase in the glomerular numbers of these cells in mice with glomerulonephritis receiving no treatment (No Tx) or vehicle, which was attenuated in mice receiving BR-4628. Furthermore, RT-PCR analysis showed that the development of glomerulonephritis resulted in significant increases in the kidney gene expression of (G) CD68, (H) CD3e, (I) CCL2, (J) TNF-α, (K) IFN-γ and (L) MMP-12 at day 15, which was reduced in mice receiving BR-4628. Magnification (A-D) x400. Graphed Data = mean ± SEM; n = 8. *p<0.05, **p<0.01, ***p<0.001.

Fig 6

Fig 6. BR-4628 does not alter salt balance.

(A) Plasma levels of K+ were similar in mice with and without glomerulonephritis, and were not affected by BR-4628 treatment. (B) After the development of glomerulonephritis there was slight reduction in urine levels of Na+/K+ in mice which received no treatment (No Tx), which was not altered by treatment with vehicle or BR-4628. Data = mean ± SEM; n = 8. *p<0.05, NS = not significant.

Similar articles

Cited by

References

    1. Bertocchio JP, Warnock DG, Jaisser F. Mineralocorticoid receptor activation and blockade: an emerging paradigm in chronic kidney disease. Kidney Int. 2011;79(10):1051–60. Epub 2011/03/18. ki201148 [pii] 10.1038/ki.2011.48 . - DOI - PubMed
    1. Shibata H, Itoh H. Mineralocorticoid receptor-associated hypertension and its organ damage: clinical relevance for resistant hypertension. Am J Hypertens. 2012;25(5):514–23. Epub 2012/01/20. ajh2011245 [pii] 10.1038/ajh.2011.245 . - DOI - PubMed
    1. Zitt E, Eller K, Huber JM, Kirsch AH, Tagwerker A, Mayer G, et al. The selective mineralocorticoid receptor antagonist eplerenone is protective in mild anti-GBM glomeru-lonephritis. Int J Clin Exp Pathol. 2011;4(6):606–15. Epub 2011/09/10. - PMC - PubMed
    1. Qin D, Morita H, Inui K, Tayama H, Inoue Y, Yoshimura A. Aldosterone mediates glomerular inflammation in experimental mesangial proliferative glomerulonephritis. J Nephrol. 2013;26:8 Epub 2012/05/30. 9A41DC4F-7589-4A6B-B209-37E32162C0DF [pii]10.5301/jn.5000125 . - DOI - PubMed
    1. Huang LL, Nikolic-Paterson DJ, Han Y, Ozols E, Ma FY, Young MJ, et al. Myeloid mineralocorticoid receptor activation contributes to progressive kidney disease. J Am Soc Nephrol. 2014;25(10):2231–40. 10.1681/ASN.2012111094 - DOI - PMC - PubMed

Publication types

MeSH terms

Substances

Grants and funding

GHT received funding from Bayer Healthcare to perform the study. PK is an employee of Bayer Healthcare and played a role in study design and manuscript preparation.

LinkOut - more resources