Sitagliptin and the Blood-Retina Barrier: Effects on Retinal Endothelial Cells Manifested Only after Prolonged Exposure

Figure 8

Prolonged treatment of iBREC with diprotin A increased expression of TJ protein claudin-1. After exposure of confluent iBREC to (a, b) 1-25 μM diprotin A for three days or (b) 10-1000 nM sitagliptin for two days, cells were harvested for preparation of cell extracts, followed by Western blot analyses. (a) Expression of claudin-1 was significantly higher after treatment with 10 and 25 μM diprotin A, but those of claudin-5 or VEcadherin were not changed. (b) Expression of caveolin-1 was also not affected by treatment with sitagliptin or diprotin A. Signals were normalized as described in Materials and Methods; for each condition.

(a)

(b)