Time-restricted feeding does not improve nephropathy in humanized sickle cell disease mice

Abstract

Sickle cell disease (SCD) is an autosomal recessive genetic disease caused by a point mutation in the hemoglobin gene. This substitution results in a “sickling” of red blood cells and subsequent vascular and organ damage. Current treatments, while increasing the lifespan of sickle cell patients, has resulted in a higher prevalence of chronic complications like SCD nephropathy. Our group has previously shown that time-restricted feeding (TRF) in chronic high fat fed mice reduces kidney damage. Given the increased kidney damage in SCD, we hypothesize that TRF in humanized SCD mice will attenuate sickle cell nephropathy. To test this hypothesis, we studied 18-22-week-old male SCD mice. Mice underwent 3 weeks of TRF, only having access to food during the active, dark period (Zeitgeber Time (ZT) 12 to 24). The control group had access to food ad libitum (ad-lib). At the end of the 3 weeks, at 21-25 week old ages, 12 hour urine was collected in metabolic cages as well as kidneys and plasma collection at ZT3 (inactive period). Excretion of urinary kidney damage markers (albumin and NGAL-1) showed no difference between TRF and ad-lib in both the active and inactive collection periods. Urinary excretion of endothelin-1 is known to be upregulated in SCD patients; however, TRF did not change this marker in SCD mice. TRF did not change plasma levels of cytokines or soluble adhesion molecules. Histological analysis of kidneys was conducted as an additional marker of kidney damage. We analyzed iron levels in the kidney with Prussian blue staining as well as fibrosis with Masson’s trichrome. TRF did not change kidney iron accumulation or kidney fibrosis. Immunohistochemical staining for CD3+ T cells did not show a difference in glomerular T cell infiltration in the TRF group compared to the ad-lib group. In conclusion, TRF does not appear to have an effect on renal inflammation or kidney function in SCD mice, but future studies need to be completed. R01 DK134562. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.