Purchase this article with an account.
Puttur Santhoshkumar, Murugesan Raju, K Krishna Sharma; Intraocular lens loaded with anti-EMT drug combinations a feasible strategy for long-term suppression of Posterior Cataract Opacification. Invest. Ophthalmol. Vis. Sci. 2016;57(12):2020.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Previously we showed that HDAC inhibitors, TSA and SAHA suppress TGFβ2-induced EMT in pig lens explants. The objective of this study was to test if intraocular lens (IOLs) soaked with a combination of HDAC inhibitor and Hsp90 inhibitor can suppress EMT in lens epithelial cells.
Hydrophilic Auroflex IOL (Aurolab) was used for soaking the drugs. 17-allylamino-17-demethoxygeldanamycin (17AAG), an Hsp90 inhibitor was used in combination with TSA or SAHA. The optimum inhibitor dosage required to soak the IOL was estimated by performing a time-course and dose-response studies with the inhibitors using Earlytox Cell Integrity Kit (Molecular Devices). The amount of inhibitor released from the IOL was estimated by HPLC at different time points using appropriate standards. To evaluate the in vitro efficacy of the inhibitors released from IOLs, the drugs released to the basal media from IOLs at different time points was tested for anti-EMT activity using human LECs and pig lens epithelial explants.
SAHA is rapid in its action and the inhibition of cell proliferation was evident by 21 h. 17-AAG took over 40 h to show its effect but is more potent in its action. The anti-proliferative effect of SAHA (1 µM) and 17-AAG (0.5 µM) in combination were comparable to the effects of 1 µM of 17-AAG alone. The dose-response studies suggest that at least 5 µM of SAHA or 1 µM of 17-AAG must be released at the first burst for the total suppression of PCO. Our studies show that SAHA begins its action early and, when its effect begins to diminish, 17 AAG displays its effect, resulting in prolonged suppression of cell proliferation with a combination of HDAC/EMT inhibitor strategy. IOLs individually incubated for 20 min with TSA (125 µM) and 17-AAG (100 µM) absorbed 38% of the TSA and 48% of the 17-AAG. A rapid burst of inhibitor release was seen during the first release cycle, after which it dropped markedly with every release cycle. At day 9, ~1.5 µM of TSA was released from the IOL, a 3-fold higher amount of TSA required to completely suppress α-SMA expression in explant culture. The 1-h release solutions from 25 µM and 100 µM SAHA-soaked IOLs completely blocked LEC proliferation.
Our data suggest that long-term suppression of EMT in LECs can be achieved by IOL delivery of a combination of HDAC/EMT inhibitors.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.
This PDF is available to Subscribers Only