Abstract
Purpose: :
Oxidative stress toward trabecular meshwork cells has an important role in developing glaucoma. Thymosin beta 4 (TB4) is a multifunctional peptide that does not only act as the actin-sequestering peptide which sequesters actin monomer from its polymerization to form an actin filament, but also is involved in various cellular functions including cell migration, angiogenesis, wound healing, and inflammation. Here, we investigated antioxidative effect of extracellular TB4 in porcine trabecular meshwork cells.
Methods: :
After serum starvation, primary cultured porcine trabecular meshwork cells (P4-6) were stimulated by hydrogen peroxide (400µM) with or without adding TB4. Reactive oxygen species (ROS) were detected with fluorescence of DCFDA (Invitrogen). Changes in Akt phosphorylation was evaluated by Western blot analysis. To further investigate effect on aqueous outflow, we used a whole eye perfusion system with analytical balance (Shimadzu). Aqueous outflow facility of porcine eyes was measured with perfusion of TB4.
Results: :
Intracellular ROS was increased with hydrogen peroxide, which was suppressed with extracellular TB4. Western blot analysis showed that expression level of phospho-Akt was increased with oxidative stress compared with control and was increased with TB4. The aqueous outflow of porcine eye with TB4 perfusion was not increased significantly compared to control.
Conclusions: :
These findings suggest that extracellular TB4 has antioxidative effect for hydrogen peroxide in porcine trabecular meshwork cells.
Keywords: trabecular meshwork • oxidation/oxidative or free radical damage • outflow: trabecular meshwork