Induced pluripotent stem cell-derived mesenchymal stem cells deliver exogenous miR-105-5p via small extracellular vesicles to rejuvenate senescent nucleus pulposus cells and attenuate intervertebral disc degeneration

Abstract

Background Mesenchymal stem cell-derived small extracellular vesicles (MSC-sEVs) have emerged as a promising new therapeutic strategy for intervertebral disc degeneration (IVDD). However, the drawbacks of MSCs, including their invasive access, the donor age, and their limited proliferative capacity, hinder the quantity and quality of MSC-sEVs. Induced pluripotent stem cell-derived MSCs (iMSCs) provide an indefinite source of MSCs with well-defined phenotype and function. This study aimed to investigate the therapeutic effect of sEVs derived from iMSC (iMSC-sEVs) on IVDD and explore the underlying molecular mechanisms. Methods IVDD models were established by puncturing discs from the tails of rats. Then, iMSC-sEVs were injected into the punctured discs. The degeneration of punctured discs was assessed using MRI and HE and immunofluorescence staining. The age-related phenotypes were used to determine the effects of iMSC-sEVs on senescent nucleus pulposus cells (NPCs) in vitro. Western blotting was used to detect the expression of Sirt6. miRNA sequencing analysis was used to find miRNAs that potentially mediate the activation of Sirt6. Results After intradiscally injecting iMSC-sEVs, NPC senescence and IVDD were significantly improved. iMSC-sEVs could rejuvenate senescent NPCs and restore the age-related function by activating the Sirt6 pathway in vitro. Further, microRNA sequence analysis showed that iMSC-sEVs were highly enriched in miR-105-5p, which played a pivotal role in the iMSC-sEV-mediated therapeutic effect by downregulating the level of the cAMP-specific hydrolase PDE4D and could lead to Sirt6 activation. Conclusion iMSC-sEVs could rejuvenate the senescence of NPCs and attenuate the development of IVDD. iMSC-sEVs exerted their anti-ageing effects by delivering miR-105-5p to senescent NPCs and activating the Sirt6 pathway. Our findings indicate that iMSCs are a promising MSC candidate for obtaining sEVs on a large scale, while avoiding several defects related to the present applications of MSCs, and that iMSC-sEVs could be a novel cell-free therapeutic tool for the treatment of IVDD.

Periodontal Ligament Stem Cell-Derived Small Extracellular Vesicles Embedded in Matrigel Enhance Bone Repair Through the Adenosine Receptor Signaling Pathway

“…4 However, the drawbacks of MSCs, including the donor age and the limited proliferative capacity, might hinder the quantity and quality of MSC-sEVs. 26 PDLSCs have been considered a suitable and abundant cell source for bone regeneration because of their easy accessibility and enhanced proliferation. 12,13 As periodontal ligament cells could increase mineralized matrix formation of bone marrow cells indirectly, PDLSC-derived secretome and sEVs are thought to have a pronounced influence on bone regeneration.…”

Mesenchymal Stem Cell-Derived Exosomes as a Novel Strategy for the Treatment of Intervertebral Disc Degeneration

“…Exosomes from BMSCs contain miR-532-5p, which inhibits matrix disintegration via the mechanism of targeting MMP-13 in degraded NPCs, resulting in the mitigation of IDD ( Zhu G. et al, 2020 ). Moreover, Sun et al demonstrated that iMSC-exosomes loaded exogenous miR-105-5p performed an integral function in the iMSC-sEV-mediated treatment impact by downregulating the catabolism markers of the ECM (ADAMTS-4 and MMP-3) and upregulating the anabolism markers (aggrecan and collagen II) ( Sun Y. et al, 2021 ). This indicates that delivering exogenous micro-RNA via MSC exosomes might be a promising therapeutic approach for IVDD.…”

Stem Cells and Exosomes: New Therapies for Intervertebral Disc Degeneration

“…While the majority of in vivo studies have been conducted on MSC-Exos, exosomes secreted by other cell lines have also been evaluated for their potential use in tissue regeneration. A rat model was used to evaluate the intradiscal injection of exosomes derived from induced pluripotent stem cell (iPS)-derived MSCs (iMSCs), and this study showed that injection diminished the progression of IVDD and the senescence of NP cells, and was capable of restoring IVD height [ 138 ]. A study on normal cartilage endplate stem cell (CESC)-derived exosomes (N-Exos) showed a decrease in the apoptotic rate of NP cells.…”