PDF(Pubmed)
Abstract：
Polysialic acid (polySia) is a carbohydrate polymer that modulates several cellular processes, such as migration, proliferation and differentiation processes. In the brain, its essential impact during postnatal development is well known. However, in most other polySia positive organs, only its localization has been described so far. For instance, in the murine epididymis, smooth muscle cells of the epididymal duct are polysialylated during the first 2 weeks of postnatal development. To understand the role of polySia during the development of the epididymis, the consequences of its loss were investigated in postnatal polySia knockout mice. As expected, no polysialylation was visible in the absence of the polysialyltransferases ST8SiaII and ST8SiaIV. Interestingly, cGMP-dependent protein kinase I (PGK1), which is essentially involved in smooth muscle cell relaxation, was not detectable in peritubular smooth muscle cells when tissue sections of polySia knockout mice were analyzed by immunohistochemistry. In contrast to this signaling molecule, the structural proteins smooth muscle actin (SMA) and calponin were expressed. As shown before, in the duct system of the testis, even the expression of these structural proteins was impaired due to the loss of polySia. We now found that the rete testis, connecting the duct system of the testis and epididymis, was extensively dilated. The obtained data suggest that less differentiated smooth muscle cells of the testis and epididymis result in disturbed contractility and thus, fluid transport within the duct system visible in the enlarged rete testis.
摘要：
聚唾液酸（polySia）是一种碳水化合物聚合物，可调节多种细胞过程，例如迁移，增殖和分化过程。在大脑中,其在产后发育过程中的重要影响是众所周知的。然而,在大多数其他多西尼亚阳性器官中，到目前为止，只描述了它的本地化。例如,在鼠附睾,在出生后的前2周，附睾管的平滑肌细胞被多唾液酸化。为了了解polySia在附睾发育过程中的作用，在出生后的polySia基因敲除小鼠中研究了其丢失的后果。不出所料,在不存在多唾液酸转移酶ST8SiaII和ST8SiaIV的情况下,没有可见多唾液酸化。有趣的是,cGMP依赖性蛋白激酶I（PGK1），本质上与平滑肌细胞松弛有关，当通过免疫组织化学分析polySia敲除小鼠的组织切片时，在肾小管周围平滑肌细胞中检测不到。与这种信号分子相反，表达结构蛋白平滑肌肌动蛋白（SMA）和钙蛋白。如前所述，在睾丸的管道系统中，甚至这些结构蛋白的表达也由于polySia的丢失而受损。我们现在发现rete睾丸，连接睾丸和附睾的管道系统，被广泛扩张。获得的数据表明，睾丸和附睾的平滑肌细胞分化较低，会导致收缩力受到干扰，因此，在扩大的睾丸网可见的管道系统内的流体输送。
