Histone deacetylases in RA: epigenetics and epiphenomena

Area of Science:

• Rheumatology
• Molecular Biology
• Epigenetics

Background:

• Histone deacetylases (HDACs) regulate gene expression epigenetically.
• Reduced synovial HDAC expression was previously hypothesized to promote rheumatoid arthritis (RA) pathogenesis.
• This hypothesis suggested enhanced transcription factor access to inflammatory gene promoters.

Discussion:

• Kawabata et al. found increased HDAC activity and expression in RA synovium and fibroblast-like synoviocytes (FLSs).
• HDAC1 expression and synovial tumor necrosis factor-alpha (TNFα) production were elevated in RA patients.
• TNFα stimulation of RA FLSs specifically increased HDAC activity and HDAC1 expression.

Key Insights:

• Synovial HDAC activity and expression are increased in RA, challenging prior assumptions.
• The observed changes in HDACs appear secondary to the local inflammatory milieu.
• TNFα plays a significant role in modulating HDAC activity in RA FLSs.

Outlook:

• Further investigation into the precise mechanisms linking TNFα and HDACs in RA is warranted.
• Targeting HDACs or their regulatory pathways could offer novel therapeutic strategies for RA.
• Understanding these epigenetic modifications may lead to improved diagnostic or prognostic biomarkers for RA.