Neurofibromatosis National Center (Centro Nacional De Neurofibromatose, CNNF), Rio De Janeiro, RJ, Brazil.
Postgraduate Program in Pathology, School of Medicine, Universidade Federal Fluminense, Niterói, RJ, Brazil.
Head Face Med. 2021 Feb 18;17(1):5. doi: 10.1186/s13005-021-00256-4.
Neurofibromin, a protein encoded by the NF1 gene, is mutated in neurofibromatosis 1, one of the most common genetic diseases. Oral manifestations are common and a high prevalence of hyposalivation was recently described in individuals with neurofibromatosis 1. Although neurofibromin is ubiquitously expressed, its expression levels vary depending on the tissue type and developmental stage of the organism. The role of neurofibromin in the development, morphology, and physiology of salivary glands is unknown and a detailed expression of neurofibromin in human normal salivary glands has never been investigated.
To investigate the expression levels and distribution of neurofibromin in acinar and ductal cells of major and minor salivary glands of adult individuals without NF1.
Ten samples of morphologically normal major and minor salivary glands (three samples of each gland: parotid, submandibular and minor salivary; and one sample of sublingual gland) from individuals without neurofibromatosis 1 were selected to assess neurofibromin expression through immunohistochemistry. Immunoquantification was performed by a digital method.
Neurofibromin was expressed in the cytoplasm of both serous and mucous acinar cells, as well as in ducts from all the samples of salivary glands. Staining intensity varied from mild to strong depending on the type of salivary gland and region (acini or ducts). Ducts had higher neurofibromin expression than acinar cells (p = 0.003). There was no statistical association between the expression of neurofibromin and the type of the salivary gland, considering acini (p = 0.09) or ducts (p = 0.50) of the four salivary glands (parotid, submandibular, minor salivary, and sublingual gland). Similar results were obtained comparing the acini (p = 0.35) and ducts (p = 0.50) of minor and major salivary glands. Besides, there was no correlation between the expression of neurofibromin and age (p = 0.08), and sex (p = 0.79) of the individuals, considering simultaneously the neurofibromin levels of acini and duct (n = 34).
Neurofibromin is expressed in the cytoplasm of serous and mucous acinar cells, and ductal cells of salivary glands, suggesting that this protein is important for salivary gland function.
神经纤维瘤蛋白是 NF1 基因编码的一种蛋白质，在神经纤维瘤病 1 中发生突变，这是最常见的遗传疾病之一。口腔表现较为常见，最近有研究描述神经纤维瘤病 1 个体存在唾液分泌减少的高患病率。尽管神经纤维瘤蛋白在体内广泛表达，但它的表达水平取决于组织类型和生物体的发育阶段。神经纤维瘤蛋白在唾液腺的发育、形态和生理功能中的作用尚不清楚，且人类正常唾液腺中神经纤维瘤蛋白的详细表达也从未被研究过。
研究神经纤维瘤蛋白在无 NF1 的成年人的大、小唾液腺的腺泡和导管细胞中的表达水平和分布。
选择 10 例形态正常的大、小唾液腺（腮腺、颌下腺和小唾液腺各 3 例，舌下腺 1 例）的组织样本，通过免疫组织化学方法评估神经纤维瘤蛋白的表达。采用数字方法进行免疫定量。
神经纤维瘤蛋白在所有唾液腺的浆液性和黏液性腺泡细胞以及导管中均有表达。染色强度因唾液腺类型和区域（腺泡或导管）而异，从轻度到强不等。与腺泡细胞相比，导管细胞的神经纤维瘤蛋白表达更高（p=0.003）。考虑到四种唾液腺（腮腺、颌下腺、小唾液腺和舌下腺）的腺泡（p=0.09）或导管（p=0.50），神经纤维瘤蛋白的表达与唾液腺类型之间无统计学关联。类似的结果也在比较大、小唾液腺的腺泡（p=0.35）和导管（p=0.50）时获得。此外，同时考虑到腺泡和导管的神经纤维瘤蛋白水平（n=34），神经纤维瘤蛋白的表达与个体的年龄（p=0.08）和性别（p=0.79）之间也没有相关性。
神经纤维瘤蛋白在唾液腺的浆液性和黏液性腺泡细胞以及导管细胞的细胞质中表达，提示该蛋白对唾液腺功能很重要。
