Tholey G, Ledig M, Bloch S, Mandel P
Neurochem Res. 1983 Oct;8(10):1233-43. doi: 10.1007/BF00963994.
In order to test the possible involvement of surface proteins on some metabolical aspects of chick glial cell differentiation in culture, perturbations were induced on the glial cell surface membrane by limited trypsinization before seeding. The developmental changes of enzymes involved in the energy metabolism of the cell: malate dehydrogenase (MDH), glutamate dehydrogenase (GDH), hexokinase (HK), lactate dehydrogenase (LDH), enolase as well as glutamine synthetase (GS) were determined in trypsin treated cells and controls. The total protein and DNA content per dish was higher in treated cells than in controls, however the protein ratio towards DNA remained unchanged. The levels of GS, GDH, LDH, and enolase activities were significantly enhanced after trypsin treatment of the cells compared to controls. The enhanced value of total LDH activity is essentially the result of the increase of M subunit containing isoenzymes. Considering that a higher level of GS activity characterizes some maturation of the glial cells (as observed during the maturation of the chick brain) it is apparent that modifications of cell surface located factors, by trypsin treatment, induce differentiation phenomena at the functional state of the glial cells in culture. This may indicate that interactions located at the cell surface are involved in the modulation of key enzymes of the energy metabolism pathway.
为了检测表面蛋白可能参与培养的鸡神经胶质细胞分化的某些代谢方面，在接种前通过有限的胰蛋白酶消化对神经胶质细胞表面膜进行扰动。测定了胰蛋白酶处理的细胞和对照细胞中参与细胞能量代谢的酶的发育变化：苹果酸脱氢酶（MDH）、谷氨酸脱氢酶（GDH）、己糖激酶（HK）、乳酸脱氢酶（LDH）、烯醇化酶以及谷氨酰胺合成酶（GS）。处理过的细胞中每皿的总蛋白和DNA含量高于对照，但蛋白与DNA的比例保持不变。与对照相比，胰蛋白酶处理细胞后，GS、GDH、LDH和烯醇化酶的活性水平显著提高。总LDH活性的增强值主要是含M亚基同工酶增加的结果。鉴于较高水平的GS活性是神经胶质细胞某些成熟的特征（如在鸡脑成熟过程中观察到的），显然通过胰蛋白酶处理对细胞表面定位因子的修饰在培养的神经胶质细胞功能状态下诱导分化现象。这可能表明位于细胞表面的相互作用参与了能量代谢途径关键酶的调节。
