Rao J S, Hantaï D, Festoff B W
Neurobiology Research Laboratory, Department of Veterans Affairs Medical Center, Kansas City, MO 64128.
J Neurol Sci. 1992 Nov;113(1):99-107. doi: 10.1016/0022-510x(92)90271-l.
In an attempt to obtain a biological marker for the enigmatic and fatal neurologic disorder, amyotrophic lateral sclerosis (ALS), several laboratories have explored alterations in various extracellular matrix components in both skeletal muscle and skin. We have studied the distribution of fibronectin, laminin, heparan sulfate proteoglycan (HSPG) and collagen types I, III and IV, along with the platelet alpha-granule glycoprotein, thrombospondin (TSP), by immunofluorescence in frozen sections of muscle from control denervating conditions and ALS patients. In ALS and control muscle, types I and III collagen were localized to the endomysium and the perimysium. Type IV collagen and laminin precisely delineated each muscle fiber (endomysium or basement membrane) but did not stain the perimysium. We found no marked quantitative or qualitative differences in the distribution of collagen types I, III and IV, laminin, fibronectin or HSPG in ALS patients compared to controls. However, when polyclonal antisera for TSP was used we found a marked increase in the deposition of this multi-domain glycoprotein in ALS patients' muscle compared to control muscle. Quantitative analysis of soluble extracts from control and ALS patients' muscle by ELISA also indicated that TSP was increased in ALS. TSP is released from platelet alpha-granules in response to thrombin stimulation. TSP elevation implies coagulation activity via the extravascular thrombolytic system in ALS and may correlate with regeneration. Other studies have indicated decreased circulating protease inhibitors and increased serine proteases in this disorder.
为了找到一种针对神秘且致命的神经系统疾病——肌萎缩侧索硬化症（ALS）的生物标志物，多个实验室对骨骼肌和皮肤中各种细胞外基质成分的变化进行了研究。我们通过免疫荧光法，在来自对照失神经支配状态的肌肉以及ALS患者的肌肉冰冻切片中，研究了纤连蛋白、层粘连蛋白、硫酸乙酰肝素蛋白聚糖（HSPG）以及I型、III型和IV型胶原蛋白的分布情况，同时还研究了血小板α颗粒糖蛋白血小板反应蛋白（TSP）的分布。在ALS患者和对照肌肉中，I型和III型胶原蛋白定位于肌内膜和肌束膜。IV型胶原蛋白和层粘连蛋白精确勾勒出每根肌纤维（肌内膜或基底膜），但未对肌束膜进行染色。我们发现，与对照组相比，ALS患者的I型、III型和IV型胶原蛋白、层粘连蛋白、纤连蛋白或HSPG的分布在数量或质量上均无明显差异。然而，当使用TSP的多克隆抗血清时，我们发现与对照肌肉相比，这种多结构域糖蛋白在ALS患者肌肉中的沉积显著增加。通过酶联免疫吸附测定法对对照和ALS患者肌肉的可溶性提取物进行定量分析也表明，ALS患者的TSP含量增加。TSP是在凝血酶刺激下从血小板α颗粒中释放出来的。TSP升高意味着ALS患者体内通过血管外溶栓系统存在凝血活性，并且可能与再生相关。其他研究表明，在这种疾病中循环中的蛋白酶抑制剂减少，丝氨酸蛋白酶增加。
