Work

Enhanced disc regeneration through CRISPR/Cas9-mediated SOX9 and TGFβ1 coexpression in tonsil-derived mesenchymal stromal cells

Year: 2025

Type: article

Abstract: BACKGROUND: Intervertebral disc (IVD) degeneration, a primary cause of chronic low back pain, currently lacks treatments that target its underlying pathological mechanisms. Tonsil-derived mesenchymal stromal cells (ToMSCs) have shown promise for IVD regeneration; however, their therapeutic potential is limited by the harsh microenvironment of degenerated discs. This study investigated whether ToMSCs engineered to co‐overexpress SOX9 and TGFβ1 using a tetracycline‐off (Tet‐off) regulatory system could enhance extracellular matrix (ECM) restoration and reduce inflammation in degenerative IVDs. METHODS: We used CRISPR/Cas9 technology to generate ToMSCs that express SOX9, TGFβ1, or both factors under Tet-off regulation. Gene expression was confirmed by Western blot and qRT-PCR analyses. In vitro studies assessed chondrogenic differentiation capacity, while in vivo assessments were performed using a rat tail needle puncture model of IVD degeneration. After administering the CRISPR-engineered ToMSCs, we monitored mechanical allodynia with the von Frey test over six weeks. Therapeutic outcomes were evaluated through T2‐weighted MRI and histological analysis. RESULTS: In vitro experiments showed that ToMSCs co-expressing SOX9 and TGFβ1 exhibited superior chondrogenic differentiation compared to cells expressing a single factor. In vivo studies demonstrated that dual-factor expressing ToMSCs significantly improved disc hydration (as confirmed by MRI), enhanced ECM synthesis—particularly aggrecan and type II collagen—and reduced inflammation compared to single-factor treatments. These improvements were accompanied by reduced mechanical allodynia, indicating functional recovery. CONCLUSION: Our study demonstrates that ToMSCs engineered to co-express SOX9 and TGFβ1 effectively promote IVD regeneration by enhancing ECM production and reducing inflammation. This dual-factor approach represents a promising therapeutic strategy for treating degenerative disc disease and warrants further investigation for clinical application.

Source: Stem Cell Research & Therapy

DOI: 10.1186/s13287-025-04600-2