Journal of extracellular vesiclesSep 8, 2025

Blocking Harmful Particles from Joint Cells to Ease Osteoarthritis: Protein Study and Cell Effects

Regenerative Health Weekly Brief ↗PubMed ↗DOI ↗OA ↗

Updated Jan 6, 2026

Abstract

Significant alterations in exosomal pathways were observed in osteoarthritis (OA) synovium.

Fibroblast-like synoviocyte (FLS)-derived (EVPs) may contribute to joint degeneration in OA.
Distinct molecular signatures were identified in EVPs from inflammatory and senescent , indicating their pathophysiological state.
Pathogenic EVPs secreted by FLSs could disrupt the balance of chondrocytes, promote inflammation, and hinder the development of cartilage-forming stem cells.
An engineered virus delivered a therapeutic agent targeting EVP secretion in a mouse model of OA, leading to reduced tissue damage and inflammation.
The approach demonstrated satisfactory safety in the systemic environment, suggesting potential for future OA treatments.

Simplified

Osteoarthritis (OA), the prevalent debilitating joint disorder, is accelerated by dysregulated intercellular crosstalk, yet the role of fibroblast-like synoviocyte (FLS)-derived (EVPs) in disease progression remains to be elucidated. Here, integrative analysis of clinical specimens, animal models, and publicly available datasets revealed significant alterations in exosomal pathways within OA synovium. Proteomic profiling revealed distinct molecular signatures in EVPs derived from inflammatory and senescent , reflecting the pathophysiological status of their parent cells. We demonstrated that FLSs under inflammatory and senescent states in OA secreted pathogenic EVPs that propagated joint degeneration by disrupting chondrocyte homeostasis, polarizing macrophages towards a pro-inflammatory phenotype, and impairing chondrogenesis of mesenchymal stem cells. To therapeutically target these pathogenic EVPs, we engineered an 9 (AAV9) vector fused with a synovium-affinity peptide (HAP-1) to deliver shRNA against Rab27a, a key regulator of EVP secretion. Intra-articular administration of the engineered AAV9 in a murine OA model induced by destabilization of the medical meniscus significantly reduced synovial hyperplasia, cartilage degradation and inflammatory responses, while demonstrating satisfactory systemic biosafety. Our findings establish FLS-derived EVPs as critical mediators of OA pathogenesis and propose a targeted strategy to block their secretion, offering a promising disease-modifying therapeutic avenue for OA.

Key numbers

2×

Increase in secretion

secretion rate in pathological vs. normal .

50%

Reduction in cartilage degradation

Cartilage degradation reduction after treatment.

Full Text

We can’t show the full text here under this license.

View Full Text ↗

Funding

Competing interests

The authors declared no conflicts of interest.

PubMed

Blocking Harmful Particles from Joint Cells to Ease Osteoarthritis: Protein Study and Cell Effects

Abstract

Key numbers

Full Text

Funding

Competing interests

You found one interesting study. We’ll send the next 7.

What Lands in Your Inbox Each Week:

Abstract

Key numbers

Full Text

Funding

Competing interests

Related papers

You found one interesting study. We’ll send the next 7.

What Lands in Your Inbox Each Week: