Exosomes derived from human placental MSCs carrying miR-4450 inhibitor alleviate intervertebral disc degeneration and ameliorate gait disturbances via up-regulation of ZNF121

Abstract

Background Exosomes derived from mesenchymal stem cells (MSCs) have emerged as novel drug and gene delivery tools. Current study aimed to elucidate the potential therapeutic role of human placental MSC (hPLMSC)-derived exosomes carrying antagomiR-4450 (EXO-antagomiR-4450) in intervertebral disc degeneration (IDD) progression. Methods Initially, the differentially expressed miRNAs related to IDD were identified by microarray analysis which provided data predicting the interaction between miR-4450 and ZNF121 in IDD. Next, miR-4450 and ZNF121 were elevated or silenced to determine their effects on the damage of NPCs treated with TNF-α. The therapeutic effects of EXO-antagomiR-4450 on nucleus pulposus cells (NPCs) were verified both in vitro and in vivo, especially gait analysis and fluorescent molecular tomopraphy were used in live IDD mice. Results Our results revealed that miR-4450 was highly expressed, while ZNF121 was poorly expressed in IDD patients and NPCs treated with TNF-α. Furthermore, miR-4450 was identified to specifically target ZNF121. Additionally, the inhibition of miR-4450 exerted an alleviatory effect on the inflammation, apoptosis and damage of the NPCs by up-regulating ZNF121. Moreover, EXO-antagomiR-4450 retarded damage of NPCs in vitro, alleviated IDD damage and ameliorated gait abnormality in vivo. Conclusion hPLMSC-derived exosomes could be a feasible nanovehicle to deliver inhibitory oligonucleotides like antagomiR-4450 in IDD.