Transforming growth factor-β Does Not Induce Endothelin-1 Secretion in Primary Cultured Human Tenon's Fibroblasts

Subconjunctival fibrosis is closely related to scarring after glaucoma filtering surgery, and transforming growth factorβ (TGF-β) is known to play a crucial role in this scarring process. It induces the transformation of fibroblasts to myofibloblasts and the production of extracellular matrix (ECM) in the Tenon’s capsule. Endothelin-1 (ET-1) is thought to be secreted by fibroblasts and contributes to fibrosis in such stressed conditions. However, evidence regarding autocrine production of ET-1 from TGF-β stimulated human Tenon’s fibroblasts are lacking. In the present study, the authors evaluated the effects of TGF-β1 on ET-1 expression from primary cultured human Tenon’s fibroblasts. Our results demonstrate that TGF-β1 seemingly has no influence on the synthesis of ET-1 in human Tenon’s fibroblasts. Even though fibroblasts usually are not a major source of ET-1, these different cellular responses may implicate the characteristics of Tenon’s fibroblasts as being different to fibroblasts from other tissue. Studies concerning other intracellular signaling pathways associated with proand antifibrosis are also needed to confirm the similarities of fibroblasts from human Tenon’s capsule with that from other organs.