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Query: UMLS:C0002895 (sickle cell disease)
 11,747 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sickle cell disease (SCD)-associated nephropathy is a major source of morbidity and mortality in patients because of the lack of efficacious treatments targeting renal manifestations of the disease. Here, we describe a long-term treatment strategy with the selective endothelin-A receptor (ETA) antagonist, ambrisentan, designed to interfere with the development of nephropathy in a humanized mouse model of SCD. Ambrisentan preserved GFR at the level of nondisease controls and prevented the development of proteinuria, albuminuria, and nephrinuria. Microscopy studies demonstrated prevention of podocyte loss and structural alterations, the absence of vascular congestion, and attenuation of glomerulosclerosis in treated mice. Studies in isolated glomeruli showed that treatment reduced inflammation and oxidative stress. At the level of renal tubules, ambrisentan treatment prevented the increased excretion of urinary tubular injury biomarkers. Additionally, the treatment strategy prevented tubular brush border loss, diminished tubular iron deposition, blocked the development of interstitial fibrosis, and prevented immune cell infiltration. Furthermore, the prevention of albuminuria in treated mice was associated with preservation of cortical megalin expression. In a separate series of identical experiments, combined ETA and ETB receptor antagonism provided only some of the protection observed with ambrisentan, highlighting the importance of exclusively targeting the ETA receptor in SCD. Our results demonstrate that ambrisentan treatment provides robust protection from diverse renal pathologies in SCD mice, and suggest that long-term ETA receptor antagonism may provide a strategy for the prevention of renal complications of SCD.
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PMID:Long-Term Endothelin-A Receptor Antagonism Provides Robust Renal Protection in Humanized Sickle Cell Disease Mice. 2844 92

Sickle cell disease is now a chronic adult illness characterized by progressive multiorgan failure, particularly involving the brain and kidney. The etiology is multifactorial; it includes hemolysis and nitric oxide deficiency. As patients age, most experience neurologic insult. Twenty-five percent of older adults have had a clinical stroke and at least half of the population have had a silent infarct, cortical atrophy, and neurocognitive impairment. Periodic screening with neuroimaging and neurocognitive testing is recommended. Identification and correction of modifiable risk factors such as nocturnal hypoxemia, obstructive sleep apnea, and physical exercise programs should be implemented. Patients with neurocognitive impairment require cognitive remediation and educational accommodations. Chronic renal disease occurs in 25% of older adults and results in 50% of their deaths. Renal failure often develops insidiously. It can be prevented or minimized by early screening and treatment of modifiable risk factors including hypertension and microalbuminuria. There is an increasing number of therapeutic options, including inhibitors of the renin angiotensin system, angiotensin-II receptor blockers, endothelin-1 receptor antagonist, and haptoglobin therapy. Patients with sickle cell disease have increased mortality rates from renal failure compared with nonsickle cell patients, in part from a lack of access to early multidisciplinary care, including timely initiation of dialysis and renal transplantation.
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PMID:Chronic organ failure in adult sickle cell disease. 2922 90

Hyperfiltration, highly prevalent early in sickle cell disease (SCD), is in part driven by an increase in ultrafiltration coefficient (Kf). The increase in Kf may be due to enlarged filtration surface area and/or increased glomerular permeability (Palb). Previous studies have demonstrated that endothelin-1 (ET-1) contributes to Palb changes in models of diabetes and SCD. Thus, we performed longitudinal studies of renal function to determine the relationship between ET-1 and glomerular size and Palb that may contribute to hyperfiltration in humanized sickle cell (HbSS) and control (HbAA) mice at 8-32 weeks of age. HbSS mice were characterized by significant increases in plasma and glomerular ET-1 expression in both sexes although this increase was significantly greater in males. HbSS glomeruli of both males and females presented with a progressive and significant increase in glomerular size, volume, and Kf During the onset of hyperfiltration, plasma and glomerular ET-1 expression were associated with a greater increase in glomerular size and Kf in HbSS mice, regardless of sex. The pattern of Palb augmentation during the hyperfiltration was also associated with an increase in glomerular ET-1 expression, in both male and female HbSS mice. However, the increase in Palb was significantly greater in males and delayed in time in females. Additionally, selective endothelin A receptor (ETA) antagonist prevented hyperfiltration in HbSS, regardless of sex. These results suggest that marked sex disparity in glomerular hyperfiltration may be driven, in part, by ET-1-dependent ultra-structural changes in filtration barrier components contributing to glomerular hyperfiltration in HbSS mice.
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PMID:Impact of ET-1 and sex in glomerular hyperfiltration in humanized sickle cell mice. 3127 50