Apoptosis of human trabecular meshwork cells induced by transforming growth factor-beta2 in vitro

Whether transforming growth factor-beta2 (TGF-beta2) induces apoptosis of human trabecular meshwork cells was investigated in vitro. Cultured 3-5 passage human trabecular meshwork cells were treated with 0 (control), 0.32, 1, 3.2 ng/ml TGF-beta2 for 48 h and divided into control group and experimental group. The apoptosis of human trabecular meshwork cells was examined by transmission electron microscopy, TUNEL technique and flow cytometry. The results showed characteristic morphologic changes of apoptotic cells were observed under transmission electron microscopy. DNA fragmentation of human trabecular meshwork cells was found by TUNEL technique. Quantitative analysis of flow cytometry showed that percentages of apoptotic human trabecular meshwork cells were (2.79 +/- 0.44)%, (4.43 +/- 1.17)% and (9.60 +/- 2.05)% respectively with different concentrations [1 ng/ml (P<0.05), 3.2 ng/ml (P<0.01)] of TGF-beta2 with the difference being significant between experimental group and control group [(1.41 +/- 0.34)%]. It was concluded that TGF-beta2 can induce apoptosis of human trabecular meshwork cells in vitro and may be involved in the decrease of trabecular meshwork cells in the patients with primary open angle glaucoma and aging of normal people.