PDF(Pubmed)
Abstract：
Sickle cell nephropathy (SCN) is a leading cause of morbidity and mortality in sickle cell disease (SCD). Early intervention is crucial for mitigating its effects. However, current diagnostic methods rely on generic tests and may not detect SCN until irreversible renal damage occurs. Therefore, specific biomarkers for early diagnosis of SCN are needed. Urinary exosomes, membrane-bound vesicles secreted by renal podocytes and epithelial cells, contain both common and cell type-specific membrane and cytosolic proteins, reflecting the physiologic and pathophysiologic states of the kidney. Using proteomics, we analyzed the proteomes of urinary exosomes from humanized SCD mice at 2 months (without albuminuria) and 4 months (with albuminuria) of age. Excretion of 164 proteins were significantly increased and 176 proteins was significantly decreased in the exosomes when mice developed albuminuria. Based on the relevance to SCD, chronic kidney disease and Western blot confirmation in mice, we analyzed protein abundance of heparanase, cathepsin C, α2-macroglobulin and sarcoplasmic endoplasmic Ca2+ ATPase-3 (SERCA3) in the urinary exosomes and urine of 18 SCD subjects without albuminuria and 12 subjects with albuminuria using Western blot analyses. Both male and female subjects increased or tended to increase the excretion of these proteins in their urinary exosomes upon developing albuminuria, but female subjects demonstrated stronger correlations between the excretion of these proteins and urine albumin creatinine ratio (UACR) compared to male subjects. In contrast, exosomal excretion of Tamm-Horsfall protein, β-actin and SHP-1 was independent of albuminuria. These findings provide a foundation for a time-course study to determine whether increases in the levels of these proteins precede the onset of albuminuria in patients, which will help determine the potential of these proteins as biomarkers for early detection of SCN.
摘要：
镰状细胞肾病(SCN)是镰状细胞病(SCD)发病和死亡的主要原因。早期干预对于减轻其影响至关重要。然而,目前的诊断方法依赖于一般检查,在发生不可逆的肾损伤之前,可能无法检测到SCN.因此,需要用于SCN早期诊断的特异性生物标志物.尿外泌体,肾足细胞和上皮细胞分泌的膜结合囊泡，含有常见和细胞类型特异性的膜蛋白和胞质蛋白，反映肾脏的生理和病理生理状态。使用蛋白质组学，我们分析了2月龄(无蛋白尿)和4月龄(有蛋白尿)的人源化SCD小鼠的尿外泌体的蛋白质组.当小鼠出现蛋白尿时，外泌体中164种蛋白质的排泄显着增加，176种蛋白质显着减少。基于与SCD的相关性，慢性肾脏疾病和小鼠的Westernblot确认，我们分析了乙酰肝素酶的蛋白质丰度，组织蛋白酶C,使用Westernblot分析，18名无白蛋白尿的SCD受试者和12名有白蛋白尿的受试者的尿外泌体和尿液中的α2-巨球蛋白和肌质内质Ca2ATPase-3（SERCA3）。男性和女性受试者在出现白蛋白尿时增加或倾向于增加尿液外泌体中这些蛋白质的排泄，但与男性受试者相比,女性受试者在这些蛋白质的排泄与尿白蛋白肌酐比率(UACR)之间表现出更强的相关性.相比之下,Tamm-Horsfall蛋白的外泌体排泄，β-肌动蛋白和SHP-1与蛋白尿无关。这些发现为一项时程研究提供了基础，以确定这些蛋白质水平的增加是否先于患者出现白蛋白尿。这将有助于确定这些蛋白质作为早期检测SCN的生物标志物的潜力。
