3.6 | TGF-β1 promoted ZO-1 and Col-a1 expression, but
inhibited the proliferation of epithelial cells, whereas MG53 yielded
reversed trends
A series of experiments, including cell proliferation and apoptosis
assays, as well as ELISA-based detection of the secretion of soluble
Col-a1 in the culture supernatant and the epithelial injury marker LDH,
were performed to further understand the effects of MG53 and TGF-β1 on
the epithelial barrier. We found that MG53 significantly promoted
epithelial cell proliferation, whereas TGF-β1 inhibited this activity
(Fig. 6A). ELISA-based analysis of soluble Col-a1 in the supernatant of
the culture maintained for 72 h showed that TGF-β1 promoted the
secretion of soluble Col-a1, whereas TGF-β1 inhibitors and Ad-MG53
reduced the secretion of soluble Col-a1 (Fig. 6B). Results of the in
vitro cell membrane injury test and ELISA showed that both TGF-β1 and
Ad-MG53 reduced LDH release (Fig. 6C). Results of flow cytometry
indicated that Ad-MG53 inhibited cell apoptosis compared with negative
control-MG53 (NC-MG53 ), (Fig. 6D).