Clifton M M, Mendelson J K, Mendelson B, Montague D, Carter C, Smoller B R, Horn T D
Department of Dermatology, University of Arkansas for Medical Sciences, Little Rock72205-7199, USA.
J Am Acad Dermatol. 2000 Jul;43(1 Pt 1):19-23. doi: 10.1067/mjd.2000.105159.
Currently there is limited knowledge regarding the anatomy of the distal arrector pili (AP) muscle. A previous study implicated fibronectin and alpha5beta1 integrin binding as the anchor between the AP and the extracellular matrix (ECM). The purpose of this study was to strengthen this hypothesis. Serial frozen sections of human scalp skin were double-labeled via immunofluorescent staining for alpha5beta1 with fluorescein and fibronectin with rhodamine, followed by fluorescent microscopy. Granular staining for alpha5beta1 with fluorescein and smooth staining for fibronectin with rhodamine were seen at the periphery of the AP muscle bundles and along the distal fibers. Precise co-localization of alpha5beta1 and fibronectin was observed at the AP-ECM interface by means of a dual filter. Analysis of variance was used on the relative density of staining for each epitope. Staining for both epitopes was significantly brighter at the distal fibers than at the middle or proximal portions of the muscle. A computerized three-dimensional reconstruction provides a detailed picture of the microanatomy of the distal AP, which allows mathematical evaluation of the forces of contraction. The anatomic co-localization between alpha5beta1 and fibronectin strengthens our hypothesis that interaction of these epitopes mediates the attachment of the distal AP to the ECM.
目前，关于立毛肌（AP）远端的解剖结构，人们了解有限。先前的一项研究表明，纤连蛋白与α5β1整合素结合是立毛肌与细胞外基质（ECM）之间的锚定连接。本研究的目的是强化这一假说。对人头皮皮肤的连续冰冻切片进行免疫荧光染色，用异硫氰酸荧光素标记α5β1，用罗丹明标记纤连蛋白，然后进行荧光显微镜观察。在立毛肌束的周边以及沿着远端纤维，可见异硫氰酸荧光素标记的α5β1呈颗粒状染色，罗丹明标记的纤连蛋白呈均匀染色。通过双滤光片观察到，在立毛肌-细胞外基质界面处，α5β1和纤连蛋白存在精确的共定位。对每个表位染色的相对密度进行方差分析。两个表位的染色在远端纤维处均明显强于肌肉的中部或近端。计算机三维重建提供了立毛肌远端微观解剖结构的详细图像，这使得对收缩力进行数学评估成为可能。α5β1和纤连蛋白在解剖学上的共定位强化了我们的假说，即这些表位的相互作用介导了立毛肌远端与细胞外基质的附着。
