Decreased proteoglycan synthesis associated with form deprivation myopia in mature primate eyes.
Decreased proteoglycan synthesis associated with form deprivation myopia in mature primate eyes.
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发表时间：
2000-07
影响因子：
4.4
通讯作者：
J. Rada;D. Nickla;D. Troilo
中科院分区：
文献类型：
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作者：
J. Rada;D. Nickla;D. Troilo
目的：研究单眼形觉剥夺对青春期绒猴巩膜蛋白多糖合成的影响，探讨成年灵长类动物近视发生过程中巩膜细胞外基质的变化。方法采用单侧眼睑缝合法诱导青春期绒猴形成形觉剥夺性近视，时间平均为108 d。重新打开眼睑后，每隔39周测量眼轴长度和屈光度。在研究期结束时，分离巩膜并立即在器官培养物中用35 SO 4进行放射性标记。用蛋白酶K消化巩膜样品后，通过测量35 SO 4掺入氯化十六烷基吡啶沉淀的糖胺聚糖来测定蛋白聚糖的合成速率。通过测定巩膜外膜中总羟脯氨酸含量来测定胶原含量。新合成的蛋白聚糖在Sepharose CL-4 B分子筛柱上分离，并通过Western印迹分析鉴定其核心蛋白。结果眼睑缝合后，玻璃体腔深度明显增加，导致近视眼的发生。Sepharose CL-4 B层析后，新合成的巩膜蛋白聚糖分离自正常，形剥夺，和对侧对照眼，解析成一个主峰，洗脱在核心蛋白聚糖的位置，一个小的软骨素-硫酸皮肤素蛋白聚糖。用软骨素酶ABC消化主峰后，通过Western印迹分析检测到约45-kDa的核心蛋白，证实核心蛋白聚糖的存在。形觉剥夺使后巩膜蛋白多糖合成率显著降低（-43.55%，P <或= 0.001）。形觉剥夺眼后巩膜蛋白多糖的合成相对于总胶原含量显著减少（-36.19%，P <或= 0.01），并与玻璃体腔延长率呈负相关（r2 = 0.779，P <或= 0.05）。结论：在青少年灵长类眼玻璃体腔延长和近视发展过程中，后巩膜细胞外基质发生了显著的重塑。形觉剥夺眼玻璃体腔延长率和核心蛋白聚糖合成率之间的负相关性表明，后巩膜内的蛋白聚糖合成在青少年绒猴的眼球大小和屈光调节中起着重要作用。
PURPOSE The rate of proteoglycan synthesis was measured in the scleras of adolescent marmosets that had undergone monocular form deprivation to characterize the scleral extracellular matrix changes associated with the development of myopia in a mature primate. METHODS Form deprivation myopia was induced in adolescent marmosets by unilateral lid suture for an average of 108 days. After the lids were reopened, the axial lengths and refractions were measured at intervals for up to 39 weeks. At the end of the study period, sclera were isolated and immediately radiolabeled with 35SO4 in organ culture. Proteoglycan synthesis rates were determined by measurement of 35SO4 incorporation into cetylpyridinium chloride-precipitable glycosaminoglycans after digestion of the scleral samples with proteinase K. Collagen content was determined by measurement of total hydroxyproline in scleral digests. Newly synthesized proteoglycans were separated on a Sepharose CL-4B molecular sieve column and identified by their core proteins by Western blot analyses. RESULTS Lid suture resulted in myopia due to a significant increase in vitreous chamber depth. After Sepharose CL-4B chromatography, newly synthesized scleral proteoglycans isolated from normal, form-deprived, and contralateral control eyes, resolved into one major peak that eluted in the position of decorin, a small chondroitin-dermatan sulfate proteoglycan. After digestion of the major peak with chondroitinase ABC, an approximately 45-kDa core protein was detected by Western blot analyses, confirming the presence of decorin. Form deprivation resulted in a significant reduction in the rate of proteoglycan synthesis in the posterior sclera (-43.55%, P < or = 0.001). Proteoglycan synthesis was also significantly reduced in the posterior sclera of form-deprived eyes relative to total collagen content (-36.19%, P < or = 0.01) and was negatively correlated with the rate of vitreous chamber elongation in the deprived eye (r2 = 0.779, P < or = 0.05). CONCLUSIONS Significant extracellular matrix remodeling occurs in the posterior sclera of the adolescent primate eye during vitreous chamber elongation and myopia development. The negative correlation between vitreous chamber elongation rates and the synthesis rates of decorin in form-deprived eyes suggests that proteoglycan synthesis within the posterior sclera plays a role in the regulation of ocular size and refraction in the adolescent marmoset.