[Experimental study of TGF-β2 antisense oligonucleotide on inhibiting corneal scar hyperplasia in rabbits].

OBJECTIVE

To investigate the influence of TGF-β2 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-β2 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-β2 mRNAs in groups A and B was significantly lower than that in groups C and D (P < 0.05).

CONCLUSIONS

TGF-β2 ASON can effectively prevent the proliferation of corneal tissue by inhibiting the activity of TGF-β2 after injury. The early stage of corneal repair is 7 days after injury, so it is important to use TGF-β2 ASON at this stage to inhibit the scar hyperplasia. In addition, it is safe to apply TGF-β2 ASON topically to protect the cornea from obvious side effects.