Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, NE 68588-6205, USA.
Proteomics and Metabolomics Facility, Nebraska Center for Biotechnology, University of Nebraska-Lincoln, Lincoln, NE 68588-0665, USA.
Nutrients. 2021 Apr 24;13(5):1448. doi: 10.3390/nu13051448.
The present study analyzed the transepithelial transport of the dietary anti-inflammatory peptide, γ-glutamyl valine (γ-EV). γ-EV is naturally found in dry edible beans. Our previous study demonstrated the anti-inflammatory potency of γ-EV against vascular inflammation at a concentration of 1mM, and that it can transport with the apparent permeability coefficient (P) of 1.56 × 10 ± 0.7 × 10 cm/s across the intestinal Caco-2 cells. The purpose of the current study was to explore whether the permeability of the peptide could be enhanced and to elucidate the mechanism of transport of γ-EV across Caco-2 cells. The initial results indicated that γ-EV was nontoxic to the Caco-2 cells up to 5 mM concentration and could be transported across the intestinal cells intact. During apical-to-basolateral transport, a higher peptide dose (5 mM) significantly ( < 0.01) enhanced the transport rate to 2.5 × 10 ± 0.6 × 10 cm/s. Cytochalasin-D disintegrated the tight-junction proteins of the Caco-2 monolayer and increased the P of γ-EV to 4.36 × 10 ± 0.16 × 10 cm/s ( < 0.001), while theaflavin 3'-gallate and Gly-Sar significantly decreased the P ( < 0.05), with wortmannin having no effects on the peptide transport, indicating that the transport route of γ-EV could be via both PepT1-mediated and paracellular.
本研究分析了膳食抗炎肽 γ-谷氨酰缬氨酸（γ-EV）的跨上皮转运。γ-EV 天然存在于干食用豆中。我们之前的研究表明，在 1mM 浓度下，γ-EV 对血管炎症具有抗炎作用，并且其表观渗透系数（P）为 1.56×10±0.7×10cm/s，可以穿过肠道 Caco-2 细胞。本研究的目的是探讨该肽的通透性是否可以增强，并阐明 γ-EV 穿过 Caco-2 细胞的转运机制。最初的结果表明，γ-EV 在高达 5mM 的浓度下对 Caco-2 细胞无毒，并且可以完整地穿过肠道细胞进行转运。在顶侧到基底侧转运过程中，较高的肽剂量（5mM）显著（<0.01）提高了转运速率至 2.5×10±0.6×10cm/s。细胞松弛素 D 破坏了 Caco-2 单层的紧密连接蛋白，使 γ-EV 的 P 增加到 4.36×10±0.16×10cm/s（<0.001），而茶黄素 3'-没食子酸酯和 Gly-Sar 显著降低了 P（<0.05），wortmannin 对肽转运没有影响，表明 γ-EV 的转运途径可以是 PepT1 介导的和细胞旁的。
