NsPEFs-enriched ADSCs-EVs alleviate osteoarthritis via RSPO3-mediated dual pro-chondrogenic and pro-M2 macrophage properties

TL;DR

NsPEFs-treated stem cell extracellular vesicles help treat osteoarthritis by promoting cartilage repair and immune modulation through RSPO3.

Contribution

Discovery of RSPO3's dual role in cartilage regeneration and M2 macrophage polarization via NsPEFs-engineered extracellular vesicles.

Findings

NsPEFs-ADSCs-EVs reduce cartilage degradation and shift macrophages to a pro-reparative M2 phenotype.

RSPO3 acts both in an autocrine and paracrine manner to enhance cartilage anabolism and macrophage polarization.

The LGR4/LRP6/β-catenin axis mediates RSPO3's pro-M2 effect in macrophages.

Abstract

Osteoarthritis (OA) remains a debilitating joint disorder due to the lack of disease-modifying therapies that can simultaneously halt cartilage degradation and modulate the aberrant immune microenvironment. This study demonstrated the therapeutic potential of extracellular vesicles derived from adipose-derived stem cells preconditioned with nanosecond pulsed electric fields (NsPEFs-ADSCs-EVs). Administration of NsPEFs-ADSCs-EVs significantly attenuated OA progression, as indicated by alleviated cartilage degradation, and a marked shift in synovial macrophage from the pro-inflammatory M1 to the pro-reparative M2 phenotype.

Mechanistically, we discovered that NsPEFs-ADSCs-EVs, via surface-enriched ITGA4, activated the PI3K/Akt pathway to instruct the increased secretion of R-spondin 3 (RSPO3). We further unveiled a novel dual function of chondrocyte-derived RSPO3. It acted in an autocrine manner to enhance chondrocyte anabolism and in a paracrine manner to directly drive M2 macrophage polarization. The pro-M2 effect was specifically mediated through the activation of the LGR4/LRP6/β-catenin signaling axis in macrophages.

Collectively, this work elucidates a previously unrecognized paracrine axis wherein NsPEFs-engineered EVs deploy RSPO3 as a significant coordinator to synchronously promote cartilage regeneration and immune resolution. Our findings not only reveal RSPO3 as a promising therapeutic target but also establish the NsPEFs platform as a efficient strategy for generating functionally enhanced EVs, offering a novel cell-free strategy for OA therapy.

Image 1

•NsPEFs-ADSCs-EVs as novel bio-active materials, exhibit high yield, homogeneity and enhanced bio-activity for OA treatment.•NsPEFs-ADSCs-EVs instruct chondrocytes to transform into active signaling hubs by ITGA4-mediated inter-cellular communication.•Chondrocyte-derived RSPO3 as a pivotal effector mediates the dual functionality, cartilage anabolism and M2 transition.•The pro-M2 effect of RSPO3 is mechanistically operated through the LGR4/LRP6/β-catenin signaling axis in macrophages.•A synergistic therapeutic strategy is proposed for OA by offering both the engineered EV platform and RSPO3 protein.

NsPEFs-ADSCs-EVs as novel bio-active materials, exhibit high yield, homogeneity and enhanced bio-activity for OA treatment.

NsPEFs-ADSCs-EVs instruct chondrocytes to transform into active signaling hubs by ITGA4-mediated inter-cellular communication.

Chondrocyte-derived RSPO3 as a pivotal effector mediates the dual functionality, cartilage anabolism and M2 transition.

The pro-M2 effect of RSPO3 is mechanistically operated through the LGR4/LRP6/β-catenin signaling axis in macrophages.

A synergistic therapeutic strategy is proposed for OA by offering both the engineered EV platform and RSPO3 protein.

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