Department of Biological Sciences and Biotechnology, School of Biological Sciences, College of Natural Sciences, Chungbuk National University, Cheongju, 28644, Republic of Korea.
Department of Molecular Medicine, College of Medicine, Ewha Womans University, 25 Magokdong-ro-2-gil, Gangseo-gu, Seoul, 07804, Republic of Korea; Graduate Program in System Health Science and Engineering, Ewha Womans University, 25 Magokdong-ro-2-gil, Gangseo-gu, Seoul, 07804, Republic of Korea.
Biomaterials. 2021 Nov;278:121156. doi: 10.1016/j.biomaterials.2021.121156. Epub 2021 Sep 25.
Controlling the senescence of mesenchymal stem cells (MSCs) is essential for improving the efficacy of MSC-based therapies. Here, a model of MSC senescence was established by replicative subculture in tonsil-derived MSCs (TMSCs) using senescence-associated β-galactosidase, telomere-length related genes, stemness, and mitochondrial metabolism. Using transcriptomic and proteomic analyses, we identified glucose-regulated protein 78 (GRP78) as a unique MSC senescence marker. With increasing cell passage number, GRP78 gradually translocated from the cell surface and cytosol to the (peri)nuclear region of TMSCs. A gelatin-based hydrogel releasing a sustained, low level of reactive oxygen species (ROS-hydrogel) was used to improve TMSC quiescence and self-renewal. TMSCs expressing cell surface-specific GRP78 (csGRP78+), collected by magnetic sorting, showed better stem cell function and higher mitochondrial metabolism than unsorted cells. Implantation of csGRP78+ cells embedded in ROS-hydrogel in rats with calvarial defects resulted in increased bone regeneration. Thus, csGRP78 is a promising biomarker of senescent TMSCs, and the combined use of csGRP78+ cells and ROS-hydrogel improved the regenerative capacity of TMSCs by regulating GRP78 translocation.
控制间充质干细胞（MSCs）的衰老对于提高基于 MSC 的治疗效果至关重要。在这里，我们通过对扁桃体来源的间充质干细胞（TMSCs）进行复制性传代培养，使用衰老相关β-半乳糖苷酶、端粒长度相关基因、干细胞特性和线粒体代谢建立了 MSC 衰老模型。通过转录组和蛋白质组分析，我们鉴定出葡萄糖调节蛋白 78（GRP78）是一种独特的 MSC 衰老标志物。随着细胞传代数的增加，GRP78 逐渐从细胞膜和细胞质转移到 TMSCs 的（核周）区域。我们使用基于明胶的水凝胶（持续释放低水平活性氧（ROS）的水凝胶）来改善 TMSC 的静止和自我更新。通过磁分选收集到的表达细胞表面特异性 GRP78（csGRP78+）的 TMSC 比未分选的细胞具有更好的干细胞功能和更高的线粒体代谢。将 csGRP78+细胞包埋在 ROS 水凝胶中植入颅骨缺损大鼠体内，可增加骨再生。因此，csGRP78 是衰老 TMSCs 的有前途的生物标志物，csGRP78+细胞和 ROS 水凝胶的联合使用通过调节 GRP78 的易位提高了 TMSC 的再生能力。
