METHODS: EVs were isolated from nKPCs derived from the urine of a preterm neonate. Three lines of urinary podocytes obtained from nephrotic patients\' urine and a line of Alport syndrome patient podocytes were characterized and used to assess albumin permeability in response to nKPC-EVs or various drugs. RNA sequencing was conducted to identify commonly modulated pathways after nKPC-EV treatment. siRNA transfection was used to demonstrate the involvement of SUMO1 and SENP2 in the modulation of permeability.
RESULTS: Treatment with the nKPC-EVs significantly reduced permeability across all the steroid-resistant patients-derived and Alport syndrome-derived podocytes. At variance, podocytes appeared unresponsive to standard pharmacological treatments, with the exception of one line, in alignment with the patient\'s clinical response at 48 months. By RNA sequencing, only two genes were commonly upregulated in nKPC-EV-treated genetically altered podocytes: small ubiquitin-related modifier 1 (SUMO1) and Sentrin-specific protease 2 (SENP2). SUMO1 and SENP2 downregulation increased podocyte permeability confirming the role of the SUMOylation pathway.
CONCLUSIONS: nKPCs emerge as a promising non-invasive source of EVs with potential therapeutic effects on podocytes with genetic dysfunction, through modulation of SUMOylation, an important pathway for the stability of podocyte slit diaphragm proteins. Our findings also suggest the feasibility of developing a non-invasive in vitro model for screening regenerative compounds on patient-derived podocytes.
方法:从早产新生儿尿液中提取的nKPCs中分离出EV。对从肾病患者尿液中获得的三行尿足细胞和一行Alport综合征患者足细胞进行了表征,并用于评估响应nKPC-EV或各种药物的白蛋白通透性。在nKPC-EV处理后进行RNA测序以鉴定通常调节的途径。使用siRNA转染来证明SUMO1和SENP2参与通透性的调节。
结果:用nKPC-EV治疗可显著降低所有类固醇耐药患者来源和Alport综合征来源足细胞的通透性。在不一致的情况下,足细胞似乎对标准药物治疗无反应,除了一行,与患者48个月时的临床反应一致。通过RNA测序,在nKPC-EV处理的遗传改变的足细胞中,通常只有两个基因上调:小泛素相关修饰因子1(SUMO1)和Sentrin特异性蛋白酶2(SENP2).SUMO1和SENP2下调增加足细胞通透性,证实了SUMO化途径的作用。
结论:nKPCs作为一种有希望的非侵入性来源,对遗传功能障碍的足细胞具有潜在的治疗作用,通过SUMOylation的调制,足细胞狭缝膈肌蛋白稳定性的重要途径。我们的发现还表明开发非侵入性体外模型以筛选患者来源的足细胞上的再生化合物的可行性。