Lampert-Etchells M, McNeill T H, Laping N J, Zarow C, Finch C E, May P C
Neurogerontology Division, Ethel Percy Andrus Gerontology Center, University of Southern California, Los Angeles 90089.
Brain Res. 1991 Nov 1;563(1-2):101-6. doi: 10.1016/0006-8993(91)91520-b.
Thios study showed responses of sulfated glycoprotein-2 (SGP-2) in the rat hippocampus after deafferenting lesion. SGP-2 is a plasma protein that also occurs in many peripheral tissues. In some circumstances, elevations of SGP-2 mRNA are associated with cell degeneration and responses to injury. This study used entorhinal cortex lesions (ECL) to partially deafferent the hippocampus by damaging the perforant path and to induce synaptic remodeling. SGP-2 mRNA is increased in hippocampal astrocytes after ECL. Western blot analysis of soluble hippocampal proteins identified 3 major forms of rat SGP-2 protein: a precursor (61 kDa) and 2 reduced subunits at 39.5 and 35 kDa. These forms increased at 4 days post ECL ipsilaterally to the lesion. By immunocytochemistry (ICC), SGP-2 showed an increased immunoreactivity on the lesioned side by 2 days post ECL that continued through 14 days post ECL. Besides immunopositive astrocytes, punctate immunochemical reaction products occurred among the degenerating fibers of the perforant path. We conclude that changes of SGP-2 protein in the hippocampus after ECL occur roughly in parallel with increases of SGP-2 mRNA. The punctate immuno-deposits could represent secreted SGP-2 and may be useful as a marker for degenerating pathways.
本研究显示了去传入性损伤后大鼠海马中硫酸化糖蛋白-2（SGP-2）的反应。SGP-2是一种血浆蛋白，也存在于许多外周组织中。在某些情况下，SGP-2 mRNA的升高与细胞变性和对损伤的反应有关。本研究采用内嗅皮质损伤（ECL）通过破坏穿通通路部分去传入海马并诱导突触重塑。ECL后海马星形胶质细胞中SGP-2 mRNA增加。对可溶性海马蛋白进行的蛋白质印迹分析确定了大鼠SGP-2蛋白的3种主要形式：一种前体（61 kDa）和2种分子量分别为39.5 kDa和35 kDa的降解亚基。这些形式在ECL后4天在损伤同侧增加。通过免疫细胞化学（ICC），SGP-2在ECL后2天在损伤侧显示出免疫反应性增加，并持续至ECL后14天。除了免疫阳性星形胶质细胞外，在穿通通路的变性纤维中出现点状免疫化学反应产物。我们得出结论，ECL后海马中SGP-2蛋白的变化大致与SGP-2 mRNA的增加平行。点状免疫沉积物可能代表分泌的SGP-2，可用作变性通路的标志物。
