性别及日龄对转人神经生长因子基因小鼠唾液中蛋白分泌的影响

Effects of gender and age on protein secretion in saliva of transgenic mice expressing human nerve growth factor

摘要:

神经生长因子 (Nerve growth factor，NGF) 是一种能促进神经元发育、分化、再生的蛋白。为高效生产药效更佳的人源NGF (hNGF) 药物，最近，笔者实验室构建出唾液腺特异表达hNGF的转基因小鼠，并从该转基因小鼠唾液中纯化获得具有高生物学活性的hNGF蛋白。为了选择性别和日龄最适宜的转hNGF基因小鼠用于收集纯化hNGF蛋白，文中比较了28日龄 (性成熟前) 雄性、雌性，63日龄 (性成熟后) 雄性、雌性转hNGF基因小鼠，共4组转hNGF基因小鼠分泌的唾液量、唾液总蛋白量、唾液鼠源NGF (mNGF) 蛋白量和唾液hNGF蛋白量等指标。结果显示，63日龄的转hNGF基因小鼠分泌的唾液量、唾液总蛋白量、唾液mNGF蛋白量和唾液hNGF蛋白量显著高于28日龄同一性别的转hNGF基因小鼠，且63日龄的雄性转hNGF基因小鼠分泌的唾液hNGF蛋白量显著高于同一日龄的雌性转hNGF基因小鼠；在4组小鼠中，63日龄的雄性转hNGF基因小鼠分泌的唾液hNGF含量最高，比28日龄雌性转hNGF基因小鼠高出约46倍，最适宜用于收集唾液并从中纯化hNGF。

Abstract:

Nerve growth factor (NGF) can promote the development, differentiation and regeneration of neurons. Recently, in order to efficiently produce human NGF (hNGF) drugs with better efficacy, we created transgenic mice expressing hNGF specifically in their salivary glands, and purified highly active hNGF protein from their saliva. Some studies reported that the NGF secretion in mouse saliva is affected by gender and age. Here, in order to select hNGF transgenic mice with high NGF secretion for saliva collection and hNGF purification, we divided transgenic mice into 4 groups, including 28-day-old young males and females, 63-day-old adult males and females. We compared their saliva volume, total salivary protein amount, salivary mNGF protein amount and salivary hNGF protein amount. The results showed that the saliva volume as well as amounts of total salivary protein, salivary mNGF protein and salivary hNGF protein secreted by 63-day-old transgenic mice were significantly higher than those secreted by sex-match 28-day-old transgenic mice, and the salivary hNGF protein amount secreted by male transgenic mice at the age of 63 days was significantly higher than that of female transgenic mice at the same age; Among 4 groups of mice, 63-day-old male transgenic mice secreted the highest salivary hNGF content, which was about 46 times higher than that secreted by the 28-day-old female transgenic mice. Therefore, 63-day-old male transgenic mice should be selected for saliva collection and hNGF purification.