Lozano-Ramos S Inés, Bancu Ioana, Carreras-Planella Laura, Monguió-Tortajada Marta, Cañas Laura, Juega Javier, Bonet Josep, Armengol M Pilar, Lauzurica Ricardo, Borràs Francesc E
REMAR-IVECAT Group, Health Science Research Institute Germans Trias i Pujol, Can Ruti Campus, Ctra. de Canyet s/n, Edifici "Escoles", 08916, Badalona, Barcelona, Spain.
Department of Cell Biology, Physiology and Immunology, Universitat Autónoma de Barcelona, 08193, Bellaterra, Cerdanyola del Vallès, Spain.
BMC Nephrol. 2018 Jul 31;19(1):189. doi: 10.1186/s12882-018-0985-3.
Kidney transplantation (KTx) is the best therapeutic approach for chronic kidney diseases leading to irreversible kidney failure. Considering the origin of the graft, several studies have reported differences between living (LD) and deceased donors (DD) in graft and patient survival. These differences seem to be related to multiple factors including, donor age and time of cold ischemia among others. Many of transplanted organs come from old-aged DDs, in which pre-transplant biopsy is recommended. However, kidney biopsy has several limitations, and there is a need to develop alternatives to assess the status of a kidney before transplantation. As the analysis of urinary extracellular vesicles (uEVs) rendered promising results as non-invasive biomarkers of kidney-related pathologies, this pilot study aimed to investigate whether profiling uEVs of LDs and DDs may be of help to assess the quality of the kidney before nephrectomy.
uEVs from 5 living donors and 7 deceased donors were isolated by size-exclusion chromatography, and their protein and miRNA content were analysed by liquid chromatography followed by mass spectrometry and next generation sequencing, respectively. Then, hierarchical clustering and venn diagrams were done with Perseus software and InteractiVenn tool. Specific EVs data bases were also used for Gene Ontology analysis.
Next generation sequencing revealed that uEVs from DDs contained less miRNAs than LDs, but most of the DD-expressed miRNAs were shared with LDs (96%). Only miR-326 (targeting the apoptotic-related Bcl2) was found significantly over-represented in LD. Focusing on the protein content, we detected a low intra-group correlation in both types of donors. Despite these differences, hierarchical clustering of either miRNA or protein data could not identify a differential profile between LDs and DDs. Of note, 90% of transplanted patients had a functional graft after a year from KTx.
In this pilot study we found that, in normo-functional grafts, minor differences in uEVs profile could not discriminate between LDs and DDs.
肾移植（KTx）是治疗导致不可逆肾衰竭的慢性肾病的最佳方法。考虑到移植物的来源，多项研究报告了活体供体（LD）和 deceased donors（DD）在移植物和患者存活方面的差异。这些差异似乎与多种因素有关，包括供体年龄和冷缺血时间等。许多移植器官来自老年 DD，建议在移植前进行活检。然而，肾活检有几个局限性，因此需要开发替代方法来评估移植前肾脏的状态。由于尿细胞外囊泡（uEVs）分析作为肾脏相关疾病的非侵入性生物标志物取得了有前景的结果，这项初步研究旨在调查分析 LD 和 DD 的 uEVs 是否有助于在肾切除术之前评估肾脏质量。
通过尺寸排阻色谱法从 5 名活体供体和 7 名 deceased donors 中分离出 uEVs，分别通过液相色谱-质谱联用和下一代测序分析其蛋白质和 miRNA 含量。然后，使用 Perseus 软件和 InteractiVenn 工具进行层次聚类和维恩图分析。还使用特定的 EVs 数据库进行基因本体分析。
下一代测序显示，DD 的 uEVs 所含 miRNA 比 LD 少，但大多数 DD 表达的 miRNA 与 LD 共享（96%）。仅发现 miR-326（靶向凋亡相关的 Bcl2）在 LD 中显著富集。关注蛋白质含量，我们在两种类型的供体中均检测到低组内相关性。尽管存在这些差异，但 miRNA 或蛋白质数据的层次聚类均无法识别 LD 和 DD 之间的差异特征。值得注意的是，90%的移植患者在 KTx 一年后拥有功能正常的移植物。
在这项初步研究中，我们发现，在功能正常的移植物中，uEVs 特征的微小差异无法区分 LD 和 DD。
