Elucidation of signaling mechanism to other organs by small intestinal Na-dependent glucose absorption mechanism

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K19717
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 59:Sports sciences, physical education, health sciences, and related fields
• Research Institution: University of Shizuoka
• Principal Investigator: Hayashi Hisayoshi 静岡県立大学, 食品栄養科学部, 准教授 (40238118)
• Project Period (FY): 2022-06-30 – 2024-03-31
• Keywords: 生活習慣病 / 腸管バリア / タイト結合

Outline of Final Research Achievements

The causes of lifestyle-related diseases are hypothesized to be due to long-term unbalanced diets and mismatches in human genes. Additionally, high intake of sugar and NaCl is also considered a cause of these diseases. However, it remains unclear how the intestine supplies the large amounts of Na necessary for nutrient absorption according to dietary intake. In this study, we examined tadpoles and frogs, which undergo a dietary shift from herbivory to carnivory, as well as genetically modified mice and rats with altered intestinal Na metabolism. The results revealed that, in all species, the barrier protein claudin-15, expressed in the intercellular spaces of the small intestinal epithelial cells, plays a crucial role in intestinal Na metabolism.

Free Research Field

生理学

Academic Significance and Societal Importance of the Research Achievements

上皮は、生体を外部環境から保護し、臓器に特有の機能を与える。上皮を通過する物質の移動には、上皮細胞を通るものと細胞間を通るものがある。腸では、単層の上皮が内腔と分離し、病原物質の流入を防ぎつつ、栄養や水分の吸収に必要な選択的透過性を保つ。このバランスが崩れると、クローン病、潰瘍性大腸炎、糖尿病などが発生する可能性がある。本研究では、腸管上皮細胞間のNa透過性にクローディン15が関与しており、健康と疾患の理解に繋がることが明らかになった。