Abstract 29: Acute Systemic Treatment With Sphingosine -1- Phosphate Receptor 1 Agonist Diminishes Sex-difference In Renal Function Seen In Intrauterine Growth Restricted Mice.

Abstract

IUGR is a risk factor for the early development of cardiorenal diseases in life. We previously showed that our IUGR mouse model exhibits sex differences in blood pressure (BP) and kidney functions as males have elevated BP and impaired kidney function while females are not. Sphingosine-1-Phosphate Receptor 1 (S1PR1) is reported to be involved in developing and progressing several cardiorenal diseases. We found that acute activation of S1PR1 transiently reduced BP in male IUGR; however, the effects of SIPR1 on renal function in IUGR are still unknown. We hypothesize that S1PR1 plays a role in the sex differences of impaired kidney function in IUGR. Here we investigated the acute effects of a specific S1PR1 agonist (SEW2178) on kidney function in IUGR offspring generated through placental insufficiency. Methods: C57BL IUGR or control offspring were obtained from the Reduced Uterine Perfusion Pressure (RUPP) or sham surgeries on the 13 th day of gestation. At 6 months, nephron number was measured by analyzing kidney histology while Glomerular Filtration Rate (GFR) was measured using FITC-Anulin decay after retroorbital injection. Mice were treated with 3mg/kg SEW2871 i.p before GFR measurement. Results: Both male and female IUGR had a decrease in nephron number compared to same-sex control (371.8± 28.8 vs 284.0± 11.3, P<0.01, male control vs IUGR) and (333.6±13.3 vs 256± 13.0, P<0.05, female control vs IUGR). Furthermore, IUGR impaired kidney function in male but not female mice as indicated by reduced GFR (8.9 ±0.6 vs 13.9±1.1 μL/min/kg BW, P<0.05, IUGR vs control males) and (12.3±0.9 vs 15.9 ±1.9 L/min/kg BW, control females vs IUGR). Administration of SEW2871 diminished the difference of GFR between male control and IUGR (9.5±0.6 vs 9.7±1.1 μL/min/kg BW, P> 0.05 control vs IUGR). While in females, both IUGR and control had a similar response to SEW2178 (7.4±1.0 vs 10.6 ±1.9 μL/min/kg BW, control vs. IUGR). Conclusion: IUGR impairs renal function in male offspring but not in females, indicating sex differences in fetal programming of kidney disease. Male and female IUGR offspring respond differently to acute systemic activation of S1PR1. Further studies are required to investigate the kidney-specific and cell-specific of S1PR1 activation/inhibition.