Klotho supplementation decreases blood pressure and albuminuria in mice with lupus nephritis

Klotho deficiency is prevalent in various chronic kidney diseases. Although klotho is known to bind transforming growth factor β (TGFβ) receptor 1 to antagonize renal fibrosis, TGFβ also maintains regulatory T cells with inducing forkhead box protein P3 (FOXP3). Female New Zealand Black/White F₁ (NZBWF1) mice were divided into two groups (n = 10 for each): one group was treated with daily subcutaneous injection of klotho protein (30 μg/kg/day) for 8 weeks, and the other only received vehicle. Klotho supplementation suppressed blood pressure, 8-epi-prostaglandin F2α excretion, albuminuria, and renal angiotensin II levels (p < 0.05 for all) without affecting the glomerular filtration rate (GFR) in NZBWF1 mice. Klotho protein supplementation reduced the number of cluster of differentiation (CD)4+FOXP3+ T cells (p < 0.05) without altering the anti-DNA antibody levels. Klotho supplementation augmented glomerular cellularity, but decreased glomerular crescent formation and interstitial fibrosis in NZBWF1 mice (p < 0.05). Klotho protein supplementation inactivated renal renin-angiotensin system, ameliorating blood pressure and albuminuria in NZBWF1 mice. Klotho supplementation hampered regulatory T cells without altering autoantibodies, exerting dual effects on glomerular pathology in NZBWF1 mice without changes in GFR.