TGF-β-3 Induces Different Effects from TGF-β-1 and-2 on Cellular Metabolism and the Spatial Properties of the Human Trabecular Meshwork Cells

To compare the effects among three TGF-beta isoforms (TGF-beta-1, TGF-beta-2, and TGF-beta-3) on the human trabecular meshwork (HTM), two-dimensional (2D) and three-dimensional (3D) cultures of commercially available certified immortalized HTM cells were used, and the following analyses were conducted: (1) trans-endothelial electrical resistance (TEER) and FITC dextran permeability measurements (2D); (2) a real-time cellular metabolic analysis (2D); (3) analysis of the physical property of the 3D HTM spheroids; and (4) an assessment of the gene expression levels of extracellular matrix (ECM) components (2D and 3D). All three TGF-beta isoforms induced a significant increase in TEER values and a relative decrease in FITC dextran permeability in the 2D-cultured HTM cells, but these effects were the most potent in the case of TGF-beta-3. The findings indicated that solutions containing 10 ng/mL of TGF-beta-1, 5 ng/mL of TGF-beta-2, and 1 ng/mL of TGF-beta-3 had nearly comparable effects on TEER measurements. However, a real-time cellular metabolic analysis of the 2D-cultured HTM cells under these concentrations revealed that TGF-3-beta induced quite different effects on the metabolic phenotype, with a decreased ATP-linked respiration, increased proton leakage, and decreased glycolytic capacity compared with TGF-beta-1 and TGF-beta-2. In addition, the concentrations of the three TGF-beta isoforms also caused diverse effects on the physical properties of 3D HTM spheroids and the mRNA expression of ECMs and their modulators, in many of which, the effects of TGF-beta-3 were markedly different from TGF-beta-1 and TGF-beta-2. The findings presented herein suggest that these diverse efficacies among the TGF-beta isoforms, especially the unique action of TGF-beta-3 toward HTM, may induce different effects within the pathogenesis of glaucoma.

Automated summary

Comparison of the effects of three TGF-beta isoforms on HTM cells revealed that TGF-beta-3 had the most potent effect on TEER and FITC dextran permeability. However, TGF-beta-3 also induced different metabolic effects and had diverse effects on the physical properties and gene expression of ECM components in comparison to TGF-beta-1 and TGF-beta-2. These findings suggest that the unique action of TGF-beta-3 may play a role in the pathogenesis of glaucoma.