Placenta-derived mesenchymal stem cells (PD-MSCs) have unique immunomodulatory properties. Phosphatase of regenerating liver-1 (PRL-1) regulates the self-renewal ability of stem cells and promotes proliferation. Graves’ ophthalmopathy (GO) is an autoimmune inflammatory disease of the orbit and is characterized by increased orbital levels of adipose tissue. Here, we evaluated the therapeutic mechanism for regulation of adipogenesis by PRL-1-overexpressing PD-MSCs (PD-MSCsPRL-1, PRL-1+) in orbital fibroblast (OF) with GO patients. PD-MSCs isolated from human placenta were transfected with the PRL-1 gene using nonviral transfection method. Primary OFs were isolated from orbital adipose tissue specimens from GO patients. After maturation as adipogenic differentiation, normal and GO-derived OFs were cocultured with naïve and PD-MSCsPRL-1. We analyzed the protein levels of adipogenesis markers and their signaling pathways in OFs from GO patients. The characteristics of PD-MSCsPRL-1 were similar to those of naïve cells. OFs from GO patients induced adipocyte differentiation and had significantly decreased a lipid accumulation after coculture with PD-MSCsPRL-1 compared to naïve cells. The mRNA and protein expression of adipogenic markers was decreased in PD-MSCsPRL-1. Insulin-like growth factor-binding proteins (IGFBPs) secreting PD-MSCsPRL-1 downregulated the phosphorylated PI3K/AKT/mTOR expression in OFs from GO patients. Interestingly, IGFBP2, − 4, − 6, and − 7 expression in PD-MSCsPRL-1, which was mediated by integrin alpha 4 (ITGA4) and beta 7 (ITGB7), was higher than that in naïve cells and upregulated phosphorylated FAK downstream factor. In summary, IGFBPs secreting PD-MSCPRL-1 inhibit adipogenesis in OFs from GO patients by upregulating phosphorylated FAK and downregulating PI3K/AKT/mTOR signaling pathway. The functional enhancement of PD-MSCs by nonviral gene modification provides a novel therapeutic strategy for the treatment of degenerative diseases.

中文翻译：

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功能增强的胎盘来源间充质干细胞抑制 Graves 眼病眼眶成纤维细胞的脂肪生成

胎盘来源的间充质干细胞 (PD-MSCs) 具有独特的免疫调节特性。再生肝磷酸酶1（PRL-1）调节干细胞的自我更新能力并促进增殖。格雷夫斯眼病 (GO) 是一种自身免疫性眼眶炎症性疾病，其特征是眼眶脂肪组织水平升高。在这里，我们评估了 PRL-1 过表达 PD-MSC（PD-MSCsPRL-1，PRL-1+）在 GO 患者眼眶成纤维细胞（OF）中调节脂肪生成的治疗机制。使用非病毒转染方法，用 PRL-1 基因转染从人胎盘中分离的 PD-MSCs。从 GO 患者的眼眶脂肪组织标本中分离出原发性 OFs。在成熟为脂肪形成分化后，正常和 GO 衍生的 OFs 与幼稚和 PD-MSCsPRL-1 共培养。我们分析了来自 GO 患者的 OFs 中脂肪生成标志物的蛋白质水平及其信号通路。PD-MSCsPRL-1 的特征与幼稚细胞的特征相似。与幼稚细胞相比，来自 GO 患者的 OFs 诱导脂肪细胞分化，并在与 PD-MSCsPRL-1 共培养后显着减少脂质积累。PD-MSCsPRL-1中脂肪形成标志物的mRNA和蛋白表达降低。分泌 PD-MSCsPRL-1 的胰岛素样生长因子结合蛋白 (IGFBPs) 下调 GO 患者 OFs 中磷酸化 PI3K/AKT/mTOR 的表达。有趣的是，由整合素α4（ITGA4）和β7（ITGB7）介导的PD-MSCsPRL-1中IGFBP2、-4、-6和-7的表达高于幼稚细胞并上调下游的磷酸化FAK因素。总之，分泌 PD-MSCPRL-1 的 IGFBP 通过上调磷酸化 FAK 和下调 PI3K/AKT/mTOR 信号通路来抑制 GO 患者 OFs 中的脂肪生成。通过非病毒基因修饰增强 PD-MSCs 的功能，为退行性疾病的治疗提供了一种新的治疗策略。