[Experimental study of TGF-ß2 antisense oligonucleotide on inhibiting corneal scar hyperplasia in rabbits].

ABSTRACT

OBJECTIVE: To investigate the influence of TGF-ß2 antisense oligonucleotide (ASON) on preventing corneal scar hyperplasia in rabbits and to provide experimental evidence for its clinical application. METHODS: It was an experimental study. One hundred and ninety two New Zealand white rabbits were randomly divided into 4 groups (groups A, B, C and D). Corneal injury models were established in all groups. There were 48 experimental animals in each group. TGF-ß2 ASON was dropped into right eyes in group A, dexamethasone was dropped into right eyes in group B, deionized water was dropped into right eyes in group C and nothing was dropped into right eyes in group D after the operation. The corneas were surgically removed and assessed by hematoxylin eosin (HE) staining, immunohistochemical study and real time PCR at four different time points (4 d, 7 d, 14 d and 28 d) after surgery. RESULTS: HE staining at the same time point, fibroblasts in the groups A and B were significantly fewer than that in the groups C and D, the difference was statistically significant (P < 0.05), but there was no significant difference between groups A and B or groups C and D. Immunohistochemical observation found that the expression of α-smooth muscle actin (α-SMA) positive fibroblasts could be observed by the 4th day (9.44 ± 0.47/HP), reached a climax by the 7th day (12.50 ± 0.81/HP), and returned to the baseline levels by the 14th day (0.85 ± 0.43/HP) in the group A, which was similar to that in the group B (9.49 ± 0.95, 12.42 ± 0.70, 0.86 ± 0.79/HP) at the same time point (P > 0.05), but it was significantly fewer than that in the group C(20.14 ± 0.78, 18.19 ± 1.28, 4.87 ± 0.58/HP) and group D(20.21 ± 0.92, 18.25 ± 1.39, 5.00 ± 2.217/HP), which was statistical significant (P < 0.05). The staining intensity of fibronectin (FN) in groups A and B was significantly weaker than that in groups C and D. Real time PCR analysis showed that at each time point, the expression of TGF-ß2 mRNAs in groups A and B was significantly lower than that in groups C and D (P < 0.05). CONCLUSIONS: TGF-ß2 ASON can effectively prevent the proliferation of corneal tissue by inhibiting the activity of TGF-ß2 after injury. The early stage of corneal repair is 7 days after injury, so it is important to use TGF-ß2 ASON at this stage to inhibit the scar hyperplasia. In addition, it is safe to apply TGF-ß2 ASON topically to protect the cornea from obvious side effects.