14-3-3η Promotes Invadosome Formation via the FOXO3-Snail Axis in Rheumatoid Arthritis Fibroblast-like Synoviocytes

Area of Science:

• Rheumatology
• Cell Biology
• Molecular Biology

Background:

• Rheumatoid arthritis (RA) involves erosive joint destruction driven by fibroblast-like synoviocytes (FLS).
• FLS degrade extracellular matrix (ECM) via invadosomes, but the underlying mechanisms are unclear.
• 14-3-3η protein expression correlates with joint damage and disease activity in RA.

Purpose of the Study:

• To investigate the role of 14-3-3η in the invadosome formation and ECM degradation by RA FLS.
• To elucidate the molecular mechanisms by which 14-3-3η influences FLS phenotype.

Main Methods:

• Analysis of 14-3-3η expression in human primary FLS from RA patients and healthy individuals.
• Manipulation of 14-3-3η levels using shRNA knockdown and recombinant protein addition.
• Assessment of invadosome formation and ECM degradation.
• Investigation of downstream targets including Snail and FOXO3.

Main Results:

• 14-3-3η expression is associated with enhanced invadosome formation in RA FLS.
• Knockdown of 14-3-3η reduced invadosome formation, while its addition promoted formation in healthy FLS.
• 14-3-3η promotes invadosome formation by increasing Snail expression via nuclear exclusion of FOXO3.
• The 14-3-3η-FOXO3-Snail axis drives ECM degradation in RA FLS.

Conclusions:

• The 14-3-3η-FOXO3-Snail pathway is crucial for the aggressive, ECM-degrading phenotype of RA FLS.
• 14-3-3η is implicated as a key mediator of cartilage degradation in rheumatoid arthritis.
• Targeting 14-3-3η may offer a therapeutic strategy for mitigating joint damage in RA.