Complement factors C1q, C3 and C5b-9 in the posterior sclera of guinea pigs with negative lens-defocused myopia

• Main Authors: Ting-Ting Gao, Qin Long, Xue Yang
• Format: Article
• Language: English
• Published: Press of International Journal of Ophthalmology (IJO PRESS) 2015-08-01
• Series: International Journal of Ophthalmology
• Subjects: experimental myopia; complement factors; sclera; inflammation
• Online Access: http://www.ijo.cn/en_publish/2015/4/20150406.pdf
• ISSN: 2222-3959; 2227-4898

<b>AIM:</b>To investigate the expression of complement factors in the posterior scleral fibroblasts of guinea pigs with negative lens-defocused myopia.<b>METHODS:</b>Eighteen guinea pigs were assigned randomly to two groups:the negative lens-defocused group (NLD group, <i>n</i>=9) and the normal control without treatment group (NC group, <i>n</i>=9). The effect of myopic induction was compared in three subgroups:eyes treated with a -10.00 D negative lens in the NLD group (NL group), eyes treated with a plano (0 D) lens in the NLD group (PL group), and untreated right eyes in the NC group (NC group). The following analyses were conducted at four weeks:examination of the refractive error <i>via </i>retinoscopy, assessment of complement C5b-9 expression in the posterior scleral fibroblasts using immunohistochemistry, and measurements of complement C1q and C3 protein levels in the posterior sclera by Western blot.<b>RESULTS:</b>After an induction period of four weeks, a significant myopic shift was detected in the eyes of the NL group, relative to that of the PL and NC groups (<i>P</i>&lt;0.05). Data analysis showed a significant increase in the percentage of C5b-9 immunopositive fibroblasts in the posterior sclera of the NL group eyes, compared to the PL group (<i>q</i>=11.50, <i>P</i>&lt;0.001). Significantly higher levels of C1q (<i>q</i>=4.94, <i>P</i>=0.01) and C3 (<i>q</i>=4.07, <i>P</i>=0.03) protein were detected in the posterior sclera of NL group eyes, compared to the PL group. There were no significant difference between the PL and NC groups for C5b-9 (<i>q</i>=2.44, <i>P</i>=0.10), C1q (<i>q</i>=1.55, <i>P</i>=0.53) and C3 (<i>q</i>=0.98, <i>P</i>=0.77) in the posterior sclera.<b>CONCLUSION:</b>The data from present study provide evidence of the up-regulation of C5b-9, C1q and C3 in the posterior scleral fibroblasts in a NLD myopic animal model. The results suggest that the complement system may be involved in the development of myopia.