Watanabe Rie, Ashida Hiroki, Kobayashi-Miura Mikiko, Yokota Akiho, Yodoi Junji
Laboratory of Infection and Prevention Department of Biological Responses Institute for Virus Research Kyoto University Kyoto Japan.
Department of Food Science Faculty of Human Life Sciences Mimasaka University Okayama Japan.
Food Sci Nutr. 2021 Jun 21;9(8):4232-4242. doi: 10.1002/fsn3.2391. eCollection 2021 Aug.
Human thioredoxin-1 (hTrx-1) is a defensive protein induced by various stresses and exerts antioxidative and anti-inflammatory effects. Previously, we described a transplastomic lettuce overexpressing hTrx-1 that exerts a protective effect against oxidative damage in a pancreatic β-cell line. In this study, we treated diabetic mice (Akita mice) with exogenous hTrx-1 and evaluated the effects.
Treatment with drinking water and single applications of exogenous hTrx-1 did not influence the feeding, drinking behavior, body weight, blood glucose, or glycosylated hemoglobin (HbA) levels in Akita mice. However, chronic administration of a 10% hTrx-1 lettuce-containing diet was associated with a significant reduction from the baseline of HbA levels compared with mice fed a wild-type lettuce-containing diet. It also resulted in an increased number of goblet cells in the small intestine, indicating that mucus was synthesized and secreted.
Our results revealed that the administration of an hTrx-1 lettuce-containing diet improves the baseline level of HbA in Akita mice. This effect is mediated through goblet cell proliferation and possibly related to protection against postprandial hyperglycemia by mucus, which results in the improvement of blood glucose control. These findings suggest that the hTrx-1 lettuce may be a useful tool for the continuous antioxidative and antidiabetic efficacies of the hTrx-1 protein.
人硫氧还蛋白-1（hTrx-1）是一种由多种应激诱导产生的防御性蛋白质，具有抗氧化和抗炎作用。此前，我们描述了一种过表达hTrx-1的转质体生菜，其对胰腺β细胞系中的氧化损伤具有保护作用。在本研究中，我们用外源性hTrx-1处理糖尿病小鼠（秋田小鼠）并评估其效果。
通过饮用水给予及单次应用外源性hTrx-1对秋田小鼠的摄食、饮水行为、体重、血糖或糖化血红蛋白（HbA）水平均无影响。然而，与喂食含野生型生菜饮食的小鼠相比，长期给予含10% hTrx-1生菜的饮食可使HbA水平较基线显著降低。这还导致小肠中杯状细胞数量增加，表明黏液得以合成和分泌。
我们的结果显示，给予含hTrx-1生菜的饮食可改善秋田小鼠的HbA基线水平。这种作用是通过杯状细胞增殖介导的，可能与黏液对餐后高血糖的保护作用有关，从而改善血糖控制。这些发现表明，含hTrx-1的生菜可能是实现hTrx-1蛋白持续抗氧化和抗糖尿病功效的有用工具。
