Center for Translational Research in Biomedical Sciences, Liver Transplantation Program and Department of Surgery, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
PLoS One. 2013 Apr 16;8(4):e60492. doi: 10.1371/journal.pone.0060492. Print 2013.
Adipose-derived mesenchymal stem cells (adipose-derived MSCs, ASCs) possess the ability to differentiate into multiple tissue types and have immune-modulatory properties similar to those of MSCs from other origins. However, the regulation of the MSC-elicited immune-modulatory activity by specific microRNA (miRNA) mechanisms remains unexplored. Gene expression profiling with knowledge-based functional enrichment analysis is an appropriate approach for unraveling these mechanisms. This tool can be used to examine the transcripts and miRNA regulators that differentiate the rat tolerogenic orthotopic liver transplantation (OLT; DA liver into PVG) and rejection OLT (DA liver into LEW) models. In both models, the rejection reaction was observed on postoperative day 7∼14 (rejection phase) but was overcome only by the PVG recipients. Thus, the global gene expression patterns of ASCs from spontaneously tolerant (PVG) and acute rejecting (LEW) rats in response to LPS activation were compared. In this study, we performed miRNA enrichment analysis based on the analysis of pathway, gene ontology (GO) terms and transcription factor binding site (TFBS) motif annotations. We found that the top candidate, miR-27, was specifically enriched and had the highest predicted frequency. We also identified a greater than 3-fold increase of miR-27b expression in the ASCs of tolerant recipients (DA to PVG) compared to those of rejecting recipients (DA to LEW) during the rejection phase in the rat OLT model. Furthermore, our data showed that miR-27b knockdown has a positive influence on the allosuppressive activity that inhibits T-cell proliferation. We found that miR-27 knockdown significantly induced the expression of CXCL12 in cultured ASCs and the expression of CXCL12 was responsible for the miR-27b antagomir-mediated inhibition of T-cell proliferation. These results, which through a series of comprehensive miRNA enrichment analyses, might be relevant for stem cell-based therapeutic applications in immunosuppressive function using ASCs.
脂肪间充质干细胞（adipose-derived MSCs，ASCs）具有分化为多种组织类型的能力，并且具有与其他来源的间充质干细胞相似的免疫调节特性。然而，特定 microRNA（miRNA）机制对 MSC 诱导的免疫调节活性的调节仍未得到探索。基于知识的功能富集分析的基因表达谱是揭示这些机制的合适方法。该工具可用于检查区分大鼠耐受型原位肝移植（OLT；DA 肝到 PVG）和排斥 OLT（DA 肝到 LEW）模型的转录物和 miRNA 调节剂。在这两种模型中，在术后第 7∼14 天（排斥期）观察到排斥反应，但仅被 PVG 受体克服。因此，比较了对 LPS 激活后来自自发耐受（PVG）和急性排斥（LEW）大鼠的 ASC 的全局基因表达模式。在这项研究中，我们根据途径、基因本体论（GO）术语和转录因子结合位点（TFBS）基序注释进行了 miRNA 富集分析。我们发现，候选 miRNA-27 特异性富集，且预测频率最高。我们还发现，在大鼠 OLT 模型的排斥期，与接受排斥的受体（DA 至 LEW）相比，耐受受体（DA 至 PVG）的 ASC 中 miR-27b 的表达增加了 3 倍以上。此外，我们的数据表明，miR-27b 的敲低对抑制 T 细胞增殖的同种异体抑制活性具有积极影响。我们发现，miR-27b 的敲低显著诱导培养的 ASCs 中 CXCL12 的表达，并且 CXCL12 的表达负责 miR-27b 拮抗剂介导的 T 细胞增殖抑制。这些结果通过一系列全面的 miRNA 富集分析表明，对于使用 ASCs 进行基于干细胞的免疫抑制功能的治疗应用可能是相关的。
