High-Mobility Group Box 1 in Dry Eye Inflammation.

Area of Science:

• Ophthalmology
• Immunology
• Molecular Biology

Background:

• Dry eye disease (DED) is a multifactorial condition affecting the ocular surface.
• High-mobility group box 1 (HMGB1) is a protein implicated in inflammatory processes.
• Understanding HMGB1's role in DED is crucial for developing targeted therapies.

Purpose of the Study:

• To investigate HMGB1 expression in experimental dry eye (EDE) models.
• To elucidate the role of HMGB1 in corneal inflammation associated with dry eye.

Main Methods:

• Induction of EDE in C57BL/6 mice and analysis of corneal HMGB1 expression via immunostaining and qPCR.
• In vitro studies using human corneal epithelial cells (HCEC) exposed to hyperosmolar media, TLR agonists, or cytokines.
• Assessment of HMGB1 secretion, inflammatory cytokine production (TNFα, IL-6, IL-8), and NF-κB activation.

Main Results:

• Corneal HMGB1 expression was significantly elevated in EDE mice compared to controls.
• Hyperosmolar stress and TNFα treatment increased HMGB1 production and secretion in HCEC.
• Recombinant HMGB1 (hrHMGB1) did not induce inflammatory cytokine secretion or NF-κB activation in HCEC.

Conclusions:

• HMGB1 expression is upregulated under dry eye conditions, both in vivo and in vitro.
• HMGB1 does not appear to directly mediate inflammation in the ocular surface under the studied conditions.
• Further research is needed to fully understand HMGB1's function in dry eye disease.