Hoya Katsumi, Asai Akio, Sasaki Tomio, Nagata Kazuya, Kimura Kenjiro, Kirino Takaaki
Department of Neurosurgery, Faculty of Medicine, University of Tokyo, Tokyo, Japan.
Acta Neuropathol. 2003 May;105(5):455-61. doi: 10.1007/s00401-002-0665-y. Epub 2003 Jan 28.
We have characterised the blood vessels found in normal cerebral vasculature and in arteriovenous malformations (AVMs), based on the expression of smooth muscle cell (SMC)-specific proteins. The marker proteins used were smooth muscle alpha-actin and four myosin heavy chain isoforms (SM1, SM2, SMemb and NMHC-A). Specimens of AVM obtained during surgery, and normal cerebral vessels from autopsy cases were studied immunohistochemically and compared. The arterial components of AVM contained an abundance of SMCs of the contractile phenotype, which were positive for alpha-actin, SM1 and SM2, but not for SMemb and NMHC-A. These components showed the same staining pattern as mature normal arteries. Two different types of abnormal veins were found in the AVM specimens: large veins with a thick and fibrous wall (so-called 'arterialised' veins) and intraparenchymal thin-walled sinusoidal veins. The former expressed alpha-actin, SM1, SM2, and SMemb, the latter expressed alpha-actin, SM1, and SM2. These marker expression patterns resembled those of normal cerebral arteries, and the results were compatible with arterialisation of the cerebral veins caused by arteriovenous shunting. However, the expression of SMemb was found only in the arterialised type of veins, not in the sinusoidal type or the arteries that had sustained abnormal blood flow in the AVMs. The thick-walled veins in the AVMs showed the same staining pattern as normal veins of dural plexus origin (large subarachnoid veins and dural sinuses). It is therefore possible to assume that they originated from the dural plexus, and extended into the brain during the formation of AVMs.
我们根据平滑肌细胞（SMC）特异性蛋白的表达，对正常脑脉管系统和动静脉畸形（AVM）中的血管进行了特征描述。所使用的标记蛋白为平滑肌α-肌动蛋白和四种肌球蛋白重链异构体（SM1、SM2、SMemb和NMHC-A）。对手术中获取的AVM标本以及尸检病例的正常脑血管进行免疫组织化学研究并比较。AVM的动脉成分含有大量收缩表型的SMC，它们对α-肌动蛋白、SM1和SM2呈阳性，但对SMemb和NMHC-A呈阴性。这些成分显示出与成熟正常动脉相同的染色模式。在AVM标本中发现了两种不同类型的异常静脉：壁增厚且呈纤维状的大静脉（所谓的“动脉化”静脉）和脑实质内薄壁的窦状静脉。前者表达α-肌动蛋白、SM1、SM2和SMemb，后者表达α-肌动蛋白、SM1和SM2。这些标记物表达模式类似于正常脑动脉，结果与动静脉分流导致的脑静脉动脉化相符。然而，仅在动脉化类型的静脉中发现了SMemb的表达，在窦状静脉类型或AVM中血流异常的动脉中未发现。AVM中的厚壁静脉显示出与硬脑膜丛起源的正常静脉（大蛛网膜下静脉和硬脑膜窦）相同的染色模式。因此，可以推测它们起源于硬脑膜丛，并在AVM形成过程中延伸至脑内。
