CCN5 Reduces Ligamentum Flavum Hypertrophy by Modulating the TGF-β Pathway

Area of Science:

• Orthopedics and Spine Surgery
• Cellular and Molecular Biology
• Biotechnology

Background:

• Ligamentum flavum hypertrophy (LFH) is a key factor in lumbar spinal canal stenosis.
• Current understanding of LFH pathophysiology is extensive, yet effective prevention or treatment methods are lacking.
• The transforming growth factor-β (TGF-β) pathway is implicated in LFH development.

Purpose of the Study:

• To investigate the potential of blocking or modulating the TGF-β pathway to prevent LFH.
• To evaluate the role of CCN5 in modulating TGF-β signaling in human LF cells.

Main Methods:

• CRISPR/Cas9 technology was used to create TGF-β receptor 1 (TGFBR1) knockout (KO) human LF cells.
• Experiments involved treating wild-type (WT) and KO LF cells with TGF-β1 and CCN5.
• Fibrosis-related factors (αSMA, fibronectin, collagen-1, collagen-3, CCN2) were assessed using qPCR, western blotting, and immunocytochemistry.

Main Results:

• TGFBR1 KO LF cells were successfully generated, showing reduced responses to TGF-β1 stimulation compared to WT cells.
• TGF-β1 treatment induced overexpression of fibrosis-related factors in WT cells, an effect significantly diminished in KO cells.
• Co-treatment with CCN5 and TGF-β1 reduced mRNA expression of fibrosis markers and inhibited TGF-β1-induced fibroblast to myofibroblast transdifferentiation.

Conclusions:

• Blocking the TGF-β pathway via TGFBR1 knockout reduces fibrosis-related gene expression in LF cells.
• CCN5 demonstrates potential in preventing LFH by modulating the TGF-β pathway.
• CCN5 may serve as a therapeutic agent to inhibit LFH progression by counteracting TGF-β1-induced cellular changes.