Inflammatory events in the corneal stroma may activate keratocytes and trigger their transition towards myofibroblasts,which now produce different extracellular matrix(ECM)proteins thus causing corneal opacification.Corneal haze is a frequent side effect after photorefractive keratectomy(PRK)to correct high myopia.Currently,a preventive treatment with mitomycin-c can be used to limit the occurrence of this phenomenon.However,mitomycin-c is a toxic drug,not devoid of side effects,which may occasionally involve the corneal endothelium.Therefore,we have searched for a less risky,natural way,to prevent keratocytes transition.To this purpose,we have used as markers of the phenotype switch the proteins lumican(highly expressed by keratocytes and much less by myofibroblasts)and smooth muscle actin(αSMA)(highly expressed by myofibroblasts and poorly found in keratocytes),beside Fibronectin(Fn),the expression of which is also increased by transforming growth factor-beta(TGFβ)treatment.Treatment of human keratocytes with TGFβwas used to induce the protein shift.Among different possible candidates,we have found that vitamins A and E,hyaluronic and lactobionic acids may prevent,either alone,or much better in association,the shift in the ratio between lumican andαSMA and the increased Fn expression.In conclusion,it could be speculated that topic treatment of the ocular surface with an association of these four compounds could be able to prevent or at least limit the occurrence of post-PRK corneal haze,with the additional advantage of lubrication,hydration and antioxidant defense exerted by these molecules.
Martina CristaldiGabriella LupoMelania OlivieriGiorgia SpampinatoCarmelina D.AnfusoDario Rusciano
AIM: To investigate the influence of minTBP-1-PRGDN on the attachment,proliferation and collagen I synthesis of human keratocyte on titanium(Ti) surface. · METHODS: The chimeric peptide RKLPDAPRGDN(minTBP-1-PRGDN) was synthesized by connecting RKLPDA(minTBP-1) to the N-terminal of PRGDN,the influence of minTBP-1-PRGDN on the attachment,proliferation and collagen I synthesis of human keratocyte on Ti surface were tested using PRGDN and minTBP-1 as controls. The keratocytes attached to the surface of Ti were either stained with FITC-labeled phalloidin and viewed with fluorescence microscope or quantified with alamar Blue method. The proliferation of keratocytes on Ti were quantified with 3-(4,5-dim-ethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide uptaking methods. The secretion of type I collagen was determined using an ELISA kit. ·RESULTS: The results showed that minTBP-1-PRGDN at a concentration of 100ng/mL was the most potent peptide to enhance the attachment of human keratocytes to the surface of Ti(1.40±0.03 folds,P =0.003),to promote the proliferation(1.26 ±0.05 folds,P =0.014) and the synthesis of type I collagen(1.530 ±0.128,P =0.008). MinTBP-1 at the same concentration could only promote the attachment(1.13±0.04 folds,P =0.020) and proliferation(1.15±0.06 folds,P =0.021),while PRGDN had no significant influence(P >0.05). ·CONCLUSION: Our data show that the novel chimericpeptide minTBP-1-PRGDN could promote the attachment,proliferation and type I collagen synthesis of human keratocytes on the surface of titanium.
Xin-Yu LiCai-Ni JiLing-Juan XuWei-Kun HuBin ZhouGui-Gang Li
