摘要背景 弱视的发生与中枢神经系统可塑性变化有关,我们先前的研究发现synapsin参与视皮层的突触可塑性过程,而神经元特异性蛋白——常规蛋白激酶C γ亚型(cPKC-γ)可能是synapsin的上游激酶之一,其在视觉发育可塑性中是否发挥或如何发挥作用尚未明确. 目的 观察随着小鼠发育其视皮层中cPKC-γ表达水平的动态变化以及异常视觉经验对cPKC-γ表达水平的影响. 方法 选取清洁级C57BL/6小鼠36只,分别于出生后(P)7、14、21、28、35、42 d各选6只小鼠,取其两侧视皮层用于研究正常小鼠随鼠龄增加视皮层中cPKC-γ表达水平的变化.另外选取清洁级C57BL/6小鼠24只以随机数字表法随机分为发育期组和成年期组,每组12只.发育期组取6只P14小鼠行右眼上下睑缝合术以制备单眼剥夺(MD)模型,其余6只小鼠不进行干预作为对照,至P28取小鼠左右两侧视皮层;成年期组取6只P60小鼠以同样方法制备MD模型,其余6只不作干预作为对照,至P74取小鼠两侧视皮层.采用Western bolt法检测小鼠两侧视皮层内cPKC-γ蛋白的表达变化.结果 正常P7小鼠可见左右侧视皮层中cPKC-γ蛋白的微弱表达,表达量的相对值分别为(39.74±11.22)％和(40.78±10.37)％,随鼠龄增加cPKC-γ蛋白的表达量逐渐增加;P21小鼠左右侧视皮层中cPKC-γ蛋白的表达量达峰值,分别为(138.68-±15.73)％和(138.47±23.48)％,此后随鼠龄增加cPKC-γ蛋白的表达量逐渐减少并稳定.不同鼠龄正常小鼠视皮层中cPKC-γ表达量的总体比较差异有统计学意义(F鼠龄=57.174,P=0.000),各组小鼠左侧与右侧视皮层中cPKC-γ蛋白表达量的总体比较差异无统计学意义(F左右=0.059,P=0.809).发育期组MD小鼠与成年期组MD小鼠间左右侧视皮层中cPKC-γ表达量的总体比较差异无统计学意义(F鼠龄=1.798,P=0.159),各组MD小鼠与正常对照小鼠间左右侧视皮层中cPKC-γ蛋白的表达量总体比较差异无统计学意义(F分组=0.104,P=0.749). 结论 正常小鼠视皮层中cPKC-γ表达量的变化趋势与视觉发育可塑性关键期相一致;MD对小鼠视皮层中cPKC-γ蛋白表达量无明显影响,但是否对cPKC-γ蛋白的活性产生影响仍需进一步研究.

abstractsBackground Plasticity of visual system is one of the mechanisms of deprivation amblyopia.Our previous study showed that synapsin plays a role during visual developmental plasticity,and conventional protein kinase C-γ (cPKC-γ) probably is one of upstream kinases of synapsin.However,whether or how the cPKC-γ plays its effects on visual developmental plasticity is below understood.Objective This study was to investigate the dynamic expression of cPKC-γ in visual cortex of normal mice and explore the effects of abnormal visual experience on cPKC-γ expression.Methods The bilateral visual cortex tissues were obtained from 36 clean C57BL/6 mice at postnatal (P) 7,14,21,28,35,42 days respectively and 6 mice for each for the researching of cPKC-γ dynamical expression in visual cortex over aging.Other 24 C57BL/6 mice were randomized into developmental phase group and adult phase group,12 for each group.The monocular deprived (MD) models were established by suturing the upper and inferior eyelides in P14 mice for 14 days in 6 mice in the developmental phase group and 6 healthy mice served as controls,and MD models were established in the same way in 6 P60 mice in the adult phase group,and the same aged mice (6 mice) were used as controls.The mice were sacrificed and bilateral visual cortexes were obtained.The expression of cPKC-γ protein in the visual cortex was quantitatively detected using Western blot assay.The study protocol was approved by Ethic Committee of Tongren Eye Hospital.The use and care of the experimental mice followed the ARVO Statement.Results The cPKC-γ protein was faintly expressed in visual cortex in normal P7 mice,with the related expressing level of (39.74± 11.22)％ and (40.78± 10.37)％ in the left and right cortex,respectively.The expressing level of cPKC-γ protein was gradually increased over aging,with the peak value of (138.68±15.73)％ and (138.47±23.48)％ in P21 mice.A significant difference was found in the expression of cPKC-γ protein in various ages of mice (Fage =57.174,P =0.000),and the expression of cPKC-γ protein was not significantly different between the left and right visual cortexses (Flateral =0.059,P =0.809).No significant differences were found in the expression of cPKC-γ protein on bilateral visual cortexes among the mice of the developmental phase group and adult phase group (Fage =1.798,P =0.159) or among the MD group and normal control group (Fgroup =0.104,P=0.749).Conclusions The dynamic expression of cPKC-γ in the visual cortex of normal mice presents a consistant tend with the aging and development of visual critical period.MD does not affect the expression of cPKC-γ protein in bilateral visual cortexes.Further researches should be performed in the activity of cPKC-γ protein in MD mice.