武汉云克隆科技股份有限公司

Abstract

AIMS:

Mesenchymal stem cells (MSCs) can ameliorate myocardial infarction (MI) injury. However, older-donor MSCs seem less efficacious than those from younger donors, and the contributing underlying mechanisms remain unknown. Here, we determine how age-related expression of pigment epithelium-derived factor (PEDF) affects MSC therapeutic efficacy for MI.

METHODS AND RESULTS:

Reverse transcriptase-polymerized chain reaction  and enzyme-linked immunosorbent assay analyses revealed dramatically increased PEDF expression in MSCs from old mice compared to young mice. Morphological and functional experiments demonstrated significantly impaired old MSC therapeutic efficacy compared with young MSCs in treatment of mice subjected to MI. Immunofluorescent staining demonstrated that administration of old MSCs compared with young MSCs resulted in an infarct region containing fewer endothelial cells, vascular smooth muscle cells, and macrophages, but more fibroblasts. Pigment epithelium-derived factor overexpression in young MSCs impaired the beneficial effects against MI injury, and induced cellular profile changes in the infarct region similar to administration of old MSCs. Knocking down PEDF expression in old MSCs improved MSC therapeutic efficacy, and induced a cellular profile similar to young MSCs administration. Studies in vitro showed that PEDF secreted by MSCs regulated the proliferation and migration of cardiac fibroblasts.

CONCLUSIONS:

This is the first evidence that paracrine factor PEDF plays critical role in the regulatory effects of MSCs against MI injury. Furthermore, the impaired therapeutic ability of aged MSCs is predominantly caused by increased PEDF secretion. These findings indicate PEDF as a promising novel genetic modification target for improving aged MSC therapeutic efficacy.

摘要

目的:

间充质干细胞（MSCs）可以改善心肌梗死（MI）损伤。然而，来源于老龄捐赠者的间充质干细胞跟来源于年轻捐助者的细胞相比，效果稍差，这个潜在的机制仍然未知。在这里，我们确定了跟年龄相关的色素上皮衍生因子（PEDF）的表达是如何影响间充质干细胞对心肌梗死的治疗效果的。

方法和结果:

反转录PCR和酶联免疫吸附试验分析显示，跟年轻的小鼠相比，来源于老龄小鼠的间充质干细胞中PEDF表达水平大幅度增加。形态和功能实验证明，跟来源于年轻小鼠的间充质干细胞相比，来源于老龄小鼠的间充质干细胞治疗心肌梗死小鼠的效果显著受损。免疫荧光染色证明，跟注入年轻的间充质干细胞相比，老的间充质干细胞导致了梗死区域包含更少的内皮细胞、血管平滑肌细胞和巨噬细胞，但有更多的成纤维细胞。与注入老的间充质干细胞相似，在年轻的间充质干细胞中过表达色素上皮衍生因子损害了对心肌梗死损伤的治疗效果，并在梗死区域诱导了细胞的形态改变。在老间充质干细胞中敲低PEDF，改善了间充质干细胞的治疗效果，并诱导细胞形态类似于注入年轻间充质干细胞后的形态。体外研究表明，间充质干细胞分泌的PEDF调节了心脏成纤维细胞的增殖和迁移。

结论:

这是第一次证明了旁分泌因子PEDF在调控间充质干细胞对心肌梗死损伤的影响中扮演关键角色。此外，老的间充质干细胞受损的治疗能力主要是由PEDF分泌增加引起的。这些发现表明，为了提高老的间充质干细胞的治疗效果，PEDF可作为一种很有希望的新型基因修饰靶标。

使用试剂原文信息：PEDF levels were also determined by a human or mouse PEDF ELISA kit (USCN Life. Science & Technology Company).