IGFBP3 (Insulin-like growth factor binding protein 3) constitutes a crucial constituent of the insulin-like growth factor (IGF), which are intimately associated with the organism's growth and development processes. Despite its significance, the precise function of IGFBP3 in yak liver development remains largely unexplored. In the present study, we systematically examined the expression profile of in the liver tissues of yaks across various growth stages, elucidated its influence on the activity of yak hepatocytes, and probed its effects on murine liver development. A comparative analysis revealed that the expression of was significantly higher in the liver tissue of 5-year-old yaks compared to their 15-month-old and 1-day-old counterparts ( < 0.01). To further validate its biological function, pET-28a-BgIGFBP3 prokaryotic expression vector was constructed. Upon exposing yak hepatocytes to varying concentrations of (Bg) IGFBP3 protein, we observed augmented cellular activities and elevated colony formation rates. Moreover, our investigation revealed the upregulation of key genes within the PI3K-Akt signaling pathway, including , , , , , , and , in both yak hepatocyte cultures and murine models. These findings collectively indicate that BgIGFBP3 promotes the proliferation of yak hepatocytes and enhances murine liver development by modulating the PI3K-Akt signaling pathway. The functional relevance of BgIGFBP3 was substantiated through and experiments, thereby underscoring its potential as a regulatory factor in liver development processes.

中文翻译：

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牦牛IGFBP3通过PI3K-Akt信号通路促进肝细胞增殖

IGFBP3（胰岛素样生长因子结合蛋白3）是胰岛素样生长因子（IGF）的重要组成部分，与生物体的生长发育过程密切相关。尽管 IGFBP3 具有重要意义，但它在牦牛肝脏发育中的精确功能在很大程度上仍未被探索。本研究系统检测了牦牛各个生长阶段肝组织中的表达谱，阐明其对牦牛肝细胞活性的影响，并探讨其对小鼠肝脏发育的影响。对比分析显示，5岁牦牛肝组织中的表达量显着高于15月龄和1日龄牦牛的肝组织（<0.01）。为了进一步验证其生物学功能，构建了pET-28a-BgIGFBP3原核表达载体。将牦牛肝细胞暴露于不同浓度的 (Bg) IGFBP3 蛋白后，我们观察到细胞活性增强和集落形成率升高。此外，我们的研究揭示了牦牛肝细胞培养物和小鼠模型中 PI3K-Akt 信号通路内关键基因的上调，包括 、 、 、 、 、 和 。这些发现共同表明，BgIGFBP3 通过调节 PI3K-Akt 信号通路促进牦牛肝细胞增殖并增强小鼠肝脏发育。 BgIGFBP3 的功能相关性通过实验得到证实，从而强调了其作为肝脏发育过程中调节因子的潜力。