Abstract

Lichen or macular localised cutaneous amyloidoses have long been described as keratinic amyloidoses and believed to be due to the deposition of cytokeratin peptides originating from epidermis in the dermal papillae. However, recently it was suggested that galectin-7 is the causative protein for this type of amyloidosis. This was based on the detection of galectin-7 in a biopsy from a patient diagnosed with Bowen’s disease and localised cutaneous amyloidosis. In this study we report mass spectrometry-based proteomic analysis of the protein composition of localised cutaneous amyloid deposits from seven patients using laser microdissection and show that basal keratins are the main constituents of the amyloid deposits. Galectin-7 was not present in the dermal amyloid deposits and was only present in the overlying Congo red negative epidermis.

摘要

苔藓或黄斑局部皮肤淀粉样变性长期以来一直被描述为角蛋白淀粉样变性，并被认为是由于源自表皮的细胞角蛋白肽在真皮乳头中的沉积。然而，最近有人提出，galectin-7 是这种淀粉样变性的致病蛋白。这是基于在诊断患有鲍文氏病和局部皮肤淀粉样变性的患者的活检中检测到 galectin-7。在这项研究中，我们报告了使用激光显微切割法对 7 名患者的局部皮肤淀粉样蛋白沉积物的蛋白质组成进行质谱分析，并表明基底角蛋白是淀粉样蛋白沉积物的主要成分。Galectin-7 不存在于真皮淀粉样蛋白沉积物中，仅存在于上覆的刚果红阴性表皮中。