TGFβ2 alters segmental outflow and ECM ultrastructure in the trabecular meshwork

Area of Science:

• Ocular biology
• Glaucoma research
• Extracellular matrix dynamics

Background:

• Transforming growth factor beta 2 (TGFβ2) is implicated in extracellular matrix (ECM) changes within the trabecular meshwork (TM).
• Elevated TGFβ2 levels in aqueous humor (AH) are observed in primary open-angle glaucoma patients.
• TGFβ2 addition to human TM cells in culture mimics glaucomatous TM pathology.

Purpose of the Study:

• To further investigate the effects of TGFβ2 overexpression using adenovirus 5 (Ad5.TGFβ2) in the mouse TM.
• To analyze the impact on ECM deposition, macrophage infiltration, and aqueous humor outflow.

Main Methods:

• Overexpression of Ad5.TGFβ2 in mouse TM.
• Analysis of macrophage marker Iba1 and ECM proteins (fibronectin, collagen 1) expression.
• Assessment of segmental AH flow and ultrastructural changes via electron microscopy.

Main Results:

• Ad5.TGFβ2 increased Iba1, fibronectin, and collagen 1 expression compared to Ad5.Null controls.
• TGFβ2 overexpression reduced segmental AH flow regions.
• Ultrastructural analysis revealed increased ECM material and more giant vacuoles in Ad5.TGFβ2 eyes.

Conclusions:

• Intraocular injection of Ad5.TGFβ2 effectively models ocular hypertension in mice.
• This model is suitable for studying TGFβ2-induced TM damage, AH outflow, and associated mechanisms.