Delivery of miR-675 by stem cell-derived exosomes encapsulated in silk fibroin hydrogel prevents aging-induced vascular dysfunction in mouse hindlimb

作者：Han, Chaoshan; Zhou, Jin; Liu, Bin; Liang, Chun; Pan, Xiangbin; Zhang, Yu; Zhang, Yuqing; Wang, Yanli; Shao, Lianbo; Zhu, Bao; Wang, Juanjuan; Yin, Qian; Yu, Xi-Yong; Li, Yangxin^*

来源：Materials Science & Engineering C-Materials for Biological Applications, 2019, 99: 322-332.

DOI：10.1016/j.msec.2019.01.122

• Exosome
• miR-675
• Silk fibroin hydrogel
• Aging
• TGF-beta 1
• Ischemic hindlimb

Vascular disease is a major complication of aging, but the molecular mechanisms underlying the aging-induced vascular dysfunction remain unclear, and there is no effective treatment to prevent aging induced diseases. The objectives of the present study are to identify the signaling pathway mediating aging-induced vascular dysfunction and to develop an exosome based therapy to inhibit aging process. We used 11-month-old C57BL6 mice as pre-aging animal model and H2O2 treated H9C2 cells as an in vitro aging model to examine the therapeutic effect of miR-675. We found decreased expression of the potential aging modulator miR-675 in aging muscle, and H2O2 treatment decreased the expression of miR-675 and upregulated the expression of the aging marker beta-gal and TGF-beta 1. We also found that miR-675 mimic decreased beta-gal staining in H2O2 treated H9C2 cells. Dual-luciferase reporter assays verified TGF-beta 1 as the target gene of miR-675. Moreover, senescent H9C2 cells incubated with exosomes isolated from UMSCs transfected with the miR-675 mimic showed increased expression of miR-675, reduced activity of the aging marker beta-gal and reduced protein levels of TGF-beta 1. We employed silk fibroin hydrogel to encapsulate exosomes in order to prolong the half-life of exosome in vivo. Fourier transform infrared spectroscopy (FTIR) revealed that exosomes were successfully encapsulated by the hydrogel. Laser Doppler perfusion imaging showed that the miR-675 exosomes encapsulated in silk fibroin hydrogel promote blood perfusion in ischemic hindlimbs. We demonstrated that miR-675 exosomes encapsulated in silk fibroin hydrogel provided sustained release of exosomes in vitro, and increased the retention time of red fluorescent PKH26-exosome in the tissue. Taken together, this study identified miR-675 as an important regulator of cell senescence and provided a novel strategy to deliver powerful exosomes by silk fibroin hydrogel to treat aging-induced vascular dysfunction.

• 出版日期2019-6
• 单位中国人民解放军第二军医大学; 吉林大学; 中国医学科学院阜外医院; 天津市中医药研究院附属医院; 苏州大学; 广州医科大学