Exploiting Joint-Resident Stem Cells by Exogenous SOX9 for Cartilage Regeneration for Therapy of Osteoarthritis

Area of Science:

• Biomedical Engineering
• Regenerative Medicine
• Orthopedics

Background:

• Osteoarthritis (OA) is characterized by articular cartilage degeneration, with limited intrinsic repair capacity.
• Current mesenchymal stem cell (MSC) therapies for OA face challenges with in vitro expansion and efficacy.
• Chondrocyte progenitors and MSCs within OA joints fail to regenerate cartilage due to SOX9 deficiency.

Purpose of the Study:

• To investigate the potential of exogenous SOX9 to induce chondrogenic differentiation and cartilage regeneration in OA.
• To evaluate the efficacy of cell-permeable, super-positively charged SOX9 (scSOX9) protein for OA treatment.

Main Methods:

• Administration of scSOX9 protein via intra-articular injection into osteoarthritic joints.
• Assessment of chondrogenic differentiation of endogenous MSCs and cartilage regeneration in vivo.

Main Results:

• scSOX9 protein successfully promoted hyaline-like cartilage regeneration.
• scSOX9 induced chondrogenic differentiation of bone marrow-derived MSCs in vivo.
• The cell-free approach leveraged intrinsic MSCs within the joint cavity.

Conclusions:

• Exogenous SOX9 can overcome the deficiency in chondrogenic transcription factor activity in OA joints.
• Intra-articular injection of scSOX9 offers a promising cell-free strategy for cartilage regeneration in OA.
• This approach harnesses the joint's endogenous stem cells for OA treatment.