Department of Food Science and Technology, Zhejiang University of Technology, Hangzhou 310014, China.
College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310027, China.
Nutrients. 2022 Jul 29;14(15):3135. doi: 10.3390/nu14153135.
A phenylalanine (Phe)-restricted diet is indispensable for individuals suffering from phenylketonuria (PKU). Our previous study reported a low-Phe-containing whey protein hydrolysate (LPH) prepared from a selected whey protein hydrolysate (TA2H). This study aimed to investigate the osteogenic activity of LPH and TA2H in MC3T3-E1 preosteoblast cells and explore the underlying mechanism. Results showed that the treatment of TA2H and LPH (at the final concentrations of 100-1000 μg/mL) had a stimulatory effect on the proliferation, differentiation, and mineralization of MC3T3-E1 cells. The LPH of 1000 μg/mL significantly increased cell proliferation (2.15- ± 0.11-fold) and alkaline phosphatase activity (1.22- ± 0.07-fold), promoted the protein and mRNA levels of runt-related transcription factor 2 (Runx2, 2.50- ± 0.14-fold and 2.97- ± 0.23-fold, respectively), enhanced the expression of differentiation biomarkers (type-I collagen, osteocalcin, and osteopontin), increased calcium deposition (1.56- ± 0.08-fold), and upregulated the ratio of osteoprotegerin/receptor activator of nuclear factor-κB ligand. The exploration of signaling pathways indicated that the activated p38-dependent Runx2 signaling contributed to the LPH-induced osteogenesis. These results provided evidence, for the first time, that a prepared low-Phe whey protein hydrolysate positively modulated the activity of osteoblasts through the p38/Runx2 pathway, thereby providing a new osteoinductive protein substitute to make functional PKU food.
苯丙氨酸限制饮食对于苯丙酮尿症（PKU）患者是必不可少的。我们之前的研究报道了一种从特定乳清蛋白水解物（TA2H）制备的低苯丙氨酸乳清蛋白水解物（LPH）。本研究旨在探讨 LPH 和 TA2H 在 MC3T3-E1 前成骨细胞中的成骨活性，并探讨其潜在机制。结果表明，TA2H 和 LPH（终浓度为 100-1000μg/mL）处理对 MC3T3-E1 细胞的增殖、分化和矿化有刺激作用。浓度为 1000μg/mL 的 LPH 显著增加细胞增殖（2.15 ± 0.11 倍）和碱性磷酸酶活性（1.22 ± 0.07 倍），促进 runt 相关转录因子 2（Runx2）的蛋白和 mRNA 水平（分别为 2.50 ± 0.14 倍和 2.97 ± 0.23 倍），增强分化生物标志物（I 型胶原、骨钙素和骨桥蛋白）的表达，增加钙沉积（1.56 ± 0.08 倍），上调骨保护素/核因子-κB 配体受体激活剂的比值。对信号通路的探索表明，激活的 p38 依赖性 Runx2 信号通路有助于 LPH 诱导的成骨作用。这些结果首次提供了证据，表明一种制备的低苯丙氨酸乳清蛋白水解物通过 p38/Runx2 通路积极调节成骨细胞活性，从而为功能性 PKU 食品提供了一种新的促骨合成蛋白替代品。
