Affiliated Children's Hospital of Soochow University, Suzhou, Jiangsu Province, 225121, People's Republic of China.
J Mol Neurosci. 2013 Mar;49(3):437-45. doi: 10.1007/s12031-012-9824-3. Epub 2012 Jun 16.
Inflammatory infiltration has been recently emphasized in the demyelinating diseases of the central nervous system including multiple sclerosis. β-1,4-Galactosyltransferase I (β-1,4-GalT-I) is a major galactosyltransferase responsible for selectin-ligand biosynthesis, mediating rolling of the inflammatory lymphocytes. In the present study, Western blot showed that expression of β-1,4-GalT-I was low in normal or complete Freund's adjuvant (CFA) control rats' spinal cords, and it began to increase since early stage and peaked at E4 stage of experimental autoimmune encephalomyelitis (EAE) and restored approximately at normal level in the recovery stage. Immunohistochemisty revealed that upregulation of β-1,4-GalT-I was predominantly distributed in the white matter of spinal cord , while there was also some increased staining of β-1,4-GalT-I in the grey matter. Meanwhile, the expression of E-selectin, the substrate of β-1,4-GalT-I, was significantly increased, with a peak at E4 stage of EAE, and gradually decreased thereafter. Lectin blot showed that the protein bands with molecular weights of 65-25 kDa reacted a remarkable increase at the peak stage of EAE when compared with the normal and CFA control. Ricinus Communis Agglutinin-I (RCA-I) histochemistry revealed that RCA-Ι-positive signals were most intense in white matter of lumbosacral spinal cord at the peak stage of EAE (E4). Immunohistochemistry showed that β-1,4-GalT-I and CD62E, a marker for E-selectin stainings located in a considerable number of ED1 (+) macrophages in perivascular or in the white matter in EAE lesions, and a good co-localization of ED1 (+) cells with CD62E was observed. All these results suggest that β-1,4-GalT-I might serve as an inflammatory mediator regulating adhesion and migration of inflammatory cells in EAE, possibly through influencing the modification of galactosylated carbohydrate chains to modulate selectin-ligand biosynthesis and interaction with E-selectin.
炎症浸润最近在中枢神经系统脱髓鞘疾病中得到了强调，包括多发性硬化症。β-1,4-半乳糖基转移酶 I（β-1,4-GalT-I）是一种主要的半乳糖基转移酶，负责选择素配体的生物合成，介导炎症淋巴细胞的滚动。在本研究中，Western blot 显示β-1,4-GalT-I 在正常或完全弗氏佐剂（CFA）对照大鼠脊髓中的表达较低，从早期开始增加，在实验性自身免疫性脑脊髓炎（EAE）的 E4 阶段达到峰值，并在恢复阶段恢复到接近正常水平。免疫组织化学显示β-1,4-GalT-I 的上调主要分布在脊髓的白质中，而在灰质中也有一些β-1,4-GalT-I 的染色增加。同时，β-1,4-GalT-I 的底物 E-选择素的表达显著增加，在 EAE 的 E4 阶段达到峰值，此后逐渐减少。凝集素印迹显示，与正常和 CFA 对照组相比，在 EAE 的峰值阶段，分子量为 65-25 kDa 的蛋白带显著增加。花生凝集素-I（RCA-I）组织化学显示，在 EAE 的峰值阶段（E4），RCA-Ι-阳性信号在腰骶脊髓的白质中最为强烈。免疫组织化学显示，β-1,4-GalT-I 和 CD62E，E-选择素的标志物，位于 EAE 病变中的血管周围或白质中的大量 ED1（+）巨噬细胞中，并且观察到 ED1（+）细胞与 CD62E 的良好共定位。所有这些结果表明，β-1,4-GalT-I 可能作为一种炎症介质，通过影响半乳糖化碳水化合物链的修饰来调节炎症细胞的粘附和迁移，从而调节选择素配体的生物合成和与 E-选择素的相互作用，从而在 EAE 中发挥作用。
