Effects Of Mechanical Stimulation On Viscoelastic Properties And Ctgf Expression Of Scleral Fibroblast

The mechanical environment where the cells are and the mechanical properties of cells affect their morphology and function, as well as the growth, proliferation and differentiation. The scleral fibroblasts are the major cellular components of sclera. In physiological state, the scleral fibroblasts are in stress state because of the intraocular pressure. The changes of scleral fibroblasts morphology and function and biomechanical properties are the basis for remodeling and the physiological, biochemical and biomechanical properties changes of sclera. The study of scleral fibroblasts response to mechanical stimulation may contribute to understanding the process of mechanical signals become biochemical changes in cells, and it can help to learn more about the visual organ physiology and the mechanisms of eye diseases pathogenesis and treatment.Effects of mechanical stimulation on cell in vitro are studied by deformation behavior of substratum technique,and that is the most common biochemical method. The effects of mechanical stimulation on viscoelastic properties and CTGF expression of scleral fibroblasts were studied by computer-driven FX-4000 Tension System. This study utilized the micropipette aspiration technique coupled with a viscoelastic solid model to investigate the viscoelastic properties of scleral fibroblasts. The concentration of CTGF was examined by ELISA.Main content and conclusions are following:1. Obtain the scleral fibroblasts of New Zealand white rabbits by tissue pieces culture method; the cells were identified with immunocytochemical method. Identification results: Vemintin (+), Desmin (-), keratin (-), S-100 (-). The results showed that the obtaining cells were scleral fibroblasts.2. The effects of mechanical stimulation on viscoelastic properties of scleral fibroblasts: The scleral fibroblasts cells were grown on six-well culture plates (the base of these culture plates consists of a flexible, collagenΙ-impregnated silicone elastic membrane). The cells were cultured 24h and medium change (DMEM medium with 15% calf serum) before experiment of stretch, experimental regimen: sine wave with 5% or 10% elongation amplitude, 48h duration, and with frequency 0.1Hz. After experiment, cells were collected and were made cell suspension for the experimentation of micropipette aspiration. Control studies were carried out simultaneously. Experimental results: Experimental studies had shown that the viscoelastic properties (equilibrium modulus E∞, instantaneous modulus E0, and apparent viscosityμ) of the scleral fibroblasts in control group were significantly higher when compared with 3% group and 6% group (p<0.05), there was no significant difference in viscoelastic properties between 3% group and 6% group (p>0.05).3. The effects of mechanical stimulation on CTGF expression of scleral fibroblasts: The scleral fibroblasts cells were grown on six-well culture plates (the base of these culture plates consists of a flexible, collagenΙ-impregnated silicone elastic membrane). The cells were cultured 24h and medium change (DMEM medium with no calf serum) before experiment of stretch, experimental regimen: sine wave with 5% or 10% elongation amplitude, 48h duration, and with frequency 0.1Hz. After experiment, cell supernatant were collected for the experimentation of ELISA. Control studies were carried out simultaneously. Experimental results: The CTGF expression of 3% group and 6% group were significantly increased when compared with respective control groups (p<0.05).The experimental results indicated that: the mechanical stimulation (sine wave, 3% and 6% elongation amplitude, 0.1Hz, 48h duration) could significantly affect the viscoelastic properties and CTGF expression of scleral fibroblasts. Different mechanical stimulation had different effects on CTGF expression of scleral fibroblasts, but all of them could promote CTGF expression of scleral fibroblasts, and the CTGF expression increased with the stretch amplitude. The results indicated that mechanical stimulation play important role in the viscoelastic properties and CTGF expression of scleral fibroblasts.