ABSTRACT
Background There have been an abundance of literature on the analysis of the mechanical characteristic of the sclera at the entire seleral level in high myopia.However,some recent studies on high myopia are focused on the mechanical changes of the sclera on a cellular level. Objective This experiment was purposed to study how transforming growth factor-β2(TGF-β2)affected sclerotic desmocytes and the mechanical behaviors of scleral fibroblasts in the posterior part of the eyes in guinea pigs with experimental myopia. Methods Induced myopic animal models were established by wearing-10.00 D concave lens for 30 days in lateral eyes of 2-week-old guinea pigs.The fellow eyes were used as control group.Another 5 matched animals served as normal controls.The scleral fibroblasts of each group were purified with the tissue explant method and passaged for 2 generations in vitro.Cultured cells were identified by immunochemistry with vimentin,desmin,keratin and S-100 antibodies.Different concentrations of TGF-β2(0,1,10,100mg/L)were added into serum-free DMEM for 24 hours,and the viscoelastic properties of scleral fibroblasts were measured by micropipette aspiration technique. Results Compared with the fellow,eyes and normal control eyes,the equilibrium modulus and apparent viscosity in model eyes were significantly higher(P＜0.05).After treatment of TGF-β2,the equilibrium modulus and apparent viscosity in the model group and fellow eyes were positively correlated with the concentrations of TGF-β2(r=0.743,r=0.533,r=0.654,r=0.576,P＜0.05).Following the addition of 1 mg/L TGF-β2 and 10 mg/L TGF-β2,the equilibrium modulus and apparent viscosity of scleral fibroblasts were significantly reduced in model eyes compared with fellow eyes(P＜0.05).No significant difference was found in the equilibrium modulus and apparent viscosity of scleral fibroblasts between model eyes and fellow eyes after treatment with 100 mg/L TGF-β2(P＞0.05). Conclusion TGF-β2 car increase the mechanic indexes in a concentration.dependent manner.1 mg/L,10 mg/L TGF-β2 can lower the equilibrium modulus and apparent viscosity of scleral fibroblasts of normal eye and thus cause more changes in the mechanical behavior of scleral fibroblasts.
ABSTRACT
<p><b>OBJECTIVE</b>To observe the position and quantity of nestin expression in SD rat eyes in different stages of postnatal development.</p><p><b>METHODS</b>Immunocytochemical method was used to identify nestin expression in the eyes of SD rats of 1 to 30 days old.</p><p><b>RESULTS</b>Nestin expression was detected in the retina and extraocular muscles of SD rats. The expression varied with the time of postnatal development, distributing in the entire retina layers in earlier stages and confined in the nerve fiber layer in later stages. The quantities of nestin expression in the extraocular muscles decreased gradually with growth.</p><p><b>CONCLUSION</b>Nestin expression in the retinas and extraocular muscles of SD rats decreases during the postnatal development.</p>