Abstract
Apolipoprotein L1 (APOL1) variants G1 and G2 contribute to the excess risk of kidney disease in individuals of recent African ancestry. Since disease mechanisms and optimal treatments remain controversial, we study the effect of current standard-of-care drugs in mouse models of APOL1 kidney disease. Experiments were performed in APOL1 BAC-transgenic mice, which develop proteinuria and glomerulosclerosis following injection with a pCpG-free IFN-γ plasmid. Proteinuric, plasmid injected G1/G1 and G2/G2 mice were randomized to drug treatment or no treatment. Lisinopril, dapagliflozin, and hydralazine were administered in drinking water starting day seven. The urine albumin/creatinine ratio was measured twice weekly, and the kidneys examined histologically with the focal segmental glomerulosclerosis score computed from periodic acid-Shiff-stained sections. The angiotensin converting enzyme inhibitor lisinopril, at standard dose, reduced proteinuria by approximately 90-fold and reduced glomerulosclerosis in the APOL1 G1/G1 BAC-transgenic mice. These effects were independent of blood pressure. Dapagliflozin did not alter disease progression in either G1/G1 or G2/G2 mice. Proteinuria reduction and glomerulosclerosis in G2/G2 BAC-transgenic mice required lisinopril doses two times higher than were effective in G1/G1 mice but achieved a much smaller benefit. Therefore, in these BAC-transgenic mouse models of APOL1 disease, the anti-proteinuric and anti-glomerulosclerotic effects of standard dose lisinopril were markedly effective in G1/G1 compared with G2/G2 APOL1 mice. Comparable reduction in blood pressure by hydralazine treatment provided no such protection. Neither G1/G1 nor G2/G2 mice showed improvement with the sodium-glucose cotransporter-2 inhibition dapagliflozin. Thus, it remains to be determined if similar differences in ACE inhibitor responsiveness are observed in patients.
Keywords:
animal model; chronic kidney disease; focal segmental glomerulosclerosis; podocyte; proteinuria; renin-angiotensin system.