碱性成纤维细胞生长因子(bFGF)在遗传性视网膜变性小鼠视网膜内的表达

A contrastive research on bFGF expression in retinas of rd mouse and C57BL mouse

目的比较碱性成纤维细胞生长因子(basic fibroblast growth factor,bFGF)在出生后五个不同周龄的rd小鼠(病变组,遗传性视网膜变性小鼠)和C57BL小鼠(正常对照组)视网膜内的表达,分析小鼠视网膜发育成熟或变性的过程中bFGF表达的异同及变化特点,进而推测bFGF在视网膜神经细胞发育分化或退变中可能的作用。方法随机选取出生后0、1、2、3、4周龄的病变组小鼠和正常对照组小鼠各8只即刻处死,摘除眼球制作视网膜切片,应用免疫组织化学法和光学显微镜法及半定量分析法对视网膜内bFGF的表达量进行测定。结果两组小鼠出生后4周内的bFGF含量曲线特点基本相同:均在出生后开始下降,至出生后1周龄时达到低谷;随后开始上升,至出生后2周龄时达到高峰,此时两组小鼠视网膜的十层结构均基本形成;2周龄后开始二次下降,直至出生后4周龄,在此期间,病变组小鼠的视网膜迅速退变,而正常对照组小鼠的视网膜继续发育成熟。在出生后0~4周各周龄,bFGF在病变组小鼠视网膜内的表达量均明显低于同龄正常对照组小鼠视网膜内的表达量,差异均有统计学意义(P<0.01)。结论 bFGF可能在视网膜神经细胞的分化成熟和形态维持中起一定的保护作用,而视网膜内bFGF处于较高表达水平可能在一定程度上能防止其退变凋亡。

Objective To compare the expressions of basic fibroblast growth factor （bFGF） in retinas of rd mouse （the experiments） and C57BL mouse （the controls） of five different postnatal ages, analyze the similarities and differences of bFGF expressions, and conclude the role of bFGF during the key period that retinas developed or degenerated. Methods Eight rd mice and eight C57BL mice of postnatal 0 week, 1 week,2 weeks,3 weeks,4 weeks （ PN 0,1,2,3,4 W） were chosen stochastically and executed immediately, their eyeballs were excavated and made into the retinal slices, then the bFGF contents in the retinas were analyzed by immunohistochemical method, photomicroscope and semi-quantitative analysis. Results Change characteristic of the curve of bFGF contents in retina of rd mice was similar to that of C57BL mice. Both curves began to fall after born, which reached each low level at PN-lW and then rose until reaching each peak at PN-2W, at which ten layer structures of retinas in both groups were formed. Then both curves began the second fall till PN-4W. During the last two weeks,retinas of C57BL mice degenerated rapidly while retinas of rd mice continued to mature. For all the five postnatal weeks, the bFGF contents in retinas of rd mice were lower than those of C57BL mice evidently. All statistical analysis of the difference have made sense distinctly （P 〈 0.01 ）. Conclusion bFGF may play a protective role in the developing to maturation and sustaining of retinal structure, and the higher expression of bFGF content may prevent retinal degeneration in some extent.