Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America.
PLoS One. 2013 Sep 5;8(9):e72115. doi: 10.1371/journal.pone.0072115. eCollection 2013.
Cardiovascular disease (CVD) is the leading cause of death in the United States. Diet influences risk factors associated with CVD and atherosclerosis, a major vascular disease that arises from inflammation. Lunasin, a peptide derived from plant foods such as soybeans, contains a unique Arg-Gly-Asp cell-adhesion motif and inhibits the pathways involved in the inflammatory cascade. The objective was to determine the mechanism by which lunasin is internalized into human THP-1 macrophages, investigate the expression of endocytic membrane proteins in inflammatory conditions and to identify the pathways involved. While lipopolysaccharide (10 nM), vitronectin (130 nM) and a combination of these two molecules enhanced lunasin uptake and increased basal αVβ3 integrin expression, lunasin reduced αVβ3 expression by 25.5, 26.8 and 49.2%, respectively. The pretreatment of cells with brefeldin A (71 µM), an inhibitor of protein trafficking, inhibited lunasin internalization by up to 99.8%. Lunasin increased caveolin-1 expression by up to 204.8%, but did not modulate clathrin. The pretreatment of macrophages with nystatin (54 µM), an inhibitor of caveolae-dependent endocytosis, reduced lunasin internalization. The presence of amantadine (1 mM) and amiloride (1 mM), inhibitors of clathrin-mediated endocytosis and macropinocytosis, abolished lunasin cell entry. Lunasin elicited a transient reduction in intracellular levels of Ca²⁺ in LPS-induced macrophages. The results suggest that internalization of lunasin into macrophages is amplified in inflammatory conditions and is primarily mediated by endocytic mechanisms that involve integrin signaling, clathrin-coated structures and macropinosomes. Lunasin may be responsible for attenuation of CVD risk factors by interacting with pathways involved in endocytosis and inflammation.
心血管疾病（CVD）是美国的主要死因。饮食会影响与 CVD 和动脉粥样硬化相关的风险因素，动脉粥样硬化是一种主要的血管疾病，由炎症引起。来自大豆等植物性食物的肽 Lunasin 含有独特的 Arg-Gly-Asp 细胞黏附基序，可抑制炎症级联反应中涉及的途径。本研究旨在确定 Lunasin 被内化进入人 THP-1 巨噬细胞的机制，研究炎症条件下内吞膜蛋白的表达，并确定涉及的途径。虽然脂多糖（10 nM）、玻连蛋白（130 nM）和这两种分子的组合增强了 Lunasin 的摄取并增加了基础αVβ3 整联蛋白的表达，但 Lunasin 分别使αVβ3 的表达减少了 25.5%、26.8%和 49.2%。用布雷非德菌素 A（71 μM）预处理细胞，一种抑制蛋白转运的抑制剂，可使 Lunasin 的内化减少多达 99.8%。Lunasin 使 caveolin-1 的表达增加高达 204.8%，但不调节网格蛋白。用制霉菌素（54 μM）预处理巨噬细胞，一种抑制 caveolae 依赖性内吞作用的抑制剂，可减少 Lunasin 的内化。用金刚烷胺（1 mM）和阿米洛利（1 mM）预处理，一种抑制网格蛋白介导的内吞作用和巨胞饮作用的抑制剂，可阻止 Lunasin 进入细胞。Lunasin 可使 LPS 诱导的巨噬细胞内 Ca²⁺水平短暂降低。结果表明，在炎症条件下，Lunasin 进入巨噬细胞的内化作用增强，主要由涉及整合素信号、网格蛋白包被结构和巨胞饮作用的内吞机制介导。Lunasin 可能通过与参与内吞作用和炎症的途径相互作用，从而降低 CVD 风险因素。
