THE L2/HNK-1 CARBOHYDRATE IS CARRIED BY THE MYELIN-ASSOCIATED GLYCOPROTEIN AND SULFATED GLUCURONYL GLYCOLIPIDS IN MUSCLE BUT NOT CUTANEOUS NERVES OF ADULT MICE
THE L2/HNK-1 CARBOHYDRATE IS CARRIED BY THE MYELIN-ASSOCIATED GLYCOPROTEIN AND SULFATED GLUCURONYL GLYCOLIPIDS IN MUSCLE BUT NOT CUTANEOUS NERVES OF ADULT MICE
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DOI：
10.1111/j.1460-9568.1994.tb00570.x
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发表时间：
1994-12-01
影响因子：
3.4
通讯作者：
SCHACHNER, M
中科院分区：
文献类型：
--
作者：
LOW, K;ORBERGER, G;SCHACHNER, M
我们之前已经证明，成年小鼠周围神经中与运动轴突相关但与感觉轴突无关的髓鞘雪旺细胞表达 L2/HNK-1 碳水化合物表位。这种由糖脂和神经细胞粘附分子携带的碳水化合物结构被认为可以在损伤后专门促进运动轴突的再生，而不是感觉轴突的再生。为了确定哪些分子成分可能是运动轴突相关髓鞘雪旺细胞中 L2 碳水化合物的载体，我们分离了成年小鼠股神经的纯感觉、皮肤分支和混合感觉和运动肌肉分支，分离了其髓磷脂部分，并通过几种免疫化学方法分析了表达 L2 碳水化合物的分子。肌肉分支髓磷脂中的 L2 免疫反应性比皮肤分支高四到五倍。肌肉分支髓磷脂中的 110 kDa L2 免疫反应性糖蛋白（其在皮肤分支中不具有 L2 免疫反应性）通过免疫沉淀和蛋白质印迹分析的组合被鉴定为髓磷脂相关糖蛋白。用有机溶剂提取髓磷脂还揭示了两种携带 L2 的糖脂，在肌肉分支的髓磷脂中相当于 40 ng 糖脂/毫克干重，而在皮肤分支的髓磷脂中没有发现显着量的 12 种糖脂。这些观察结果表明，髓鞘雪旺细胞中碳水化合物合成活性的差异调节程度令人惊讶。
We have previously shown that myelinating Schwann cells associated with motor, but not sensory, axons in peripheral nerves of adult mice express the L2/HNK-1 carbohydrate epitope. This carbohydrate structure carried by glycolipids and neural cell adhesion molecules has been suggested to specifically foster regrowth of motor as opposed to sensory axons after infliction of a lesion. To determine which molecular components may be the carriers of the L2 carbohydrate in motor axon-associated myelinating Schwann cells, we have isolated the purely sensory, cutaneous branch and the mixed sensory and motor muscle branch of the femoral nerve of adult mice, isolated the myelin fraction thereof and analysed the molecules expressing the L2 carbohydrate by several immunochemical methods. L2 immunoreactivity in myelin of the muscle branch was four to five times higher than that of the cutaneous branch. The 110 kDa L2-immunoreactive glycoprotein in myelin of the muscle branch, which is not L2-immunoreactive in the cutaneous branch, was identified as the myelin-associated glycoprotein by a combination of immunoprecipitation and Western blot analysis. Myelin extraction with organic solvents additionally revealed the two L2-carrying glycolipids, which amounted to similar to 40 ng glycolipid/mg dry weight in myelin of the muscle branch, whereas no significant amounts of the 12 glycolipids were found in myelin of the cutaneous branch. These observations suggest an astonishing degree of differential regulation of carbohydrate-synthesizing activities in myelinating Schwann cells.