高血糖時に膵β細胞を増やす分子スイッチを発見―糖尿病で失われる膵β細胞量回復へつながる新たな治療標的―

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2026-04-20 京都大学

京都大学などの研究チームは、高血糖時に膵β細胞の増殖を制御する分子スイッチとして転写因子ChREBPの役割を解明し、Journal of Diabetes Investigationに発表した。マウス実験により、インスリン抵抗性や高血糖状態ではChREBPが膵β細胞増殖に必須であり、欠損すると増殖が大きく抑制されることが判明。一方、妊娠時の生理的変化では影響が限定的だった。さらに標的遺伝子Rgs16が高血糖下で誘導され、増殖に関与する可能性も示された。これにより、代謝ストレス応答として膵β細胞量を維持する新たな分子機構が明らかとなった。本成果は、糖尿病で減少する膵β細胞の回復を目指す新規治療標的の開発につながると期待される。

高血糖時に膵β細胞を増やす分子スイッチを発見―糖尿病で失われる膵β細胞量回復へつながる新たな治療標的―

<関連情報>

ChREBPは代謝ストレス下ではβ細胞増殖を促進するが、妊娠誘発性β細胞増殖には関与しない ChREBP drives β-cell proliferation under metabolic stress but not in pregnancy-induced β-cell expansion

Sodai Kubota, Seiya Banno, Katsumi Iizuka, Hiromi Tsuchida, Saki Kubota-Okamoto, Teruaki Sakurai, Yoshihiro Takahashi, Toshinori Imaizumi, Takehiro Kato, Yukio Horikawa, …
Journal of Diabetes Investigation  Published: 15 April 2026
DOI:https://doi.org/10.1111/jdi.70295

ABSTRACT

Aims/Introduction

Carbohydrate responsive element-binding protein (ChREBP) is a glucose-activated transcription factor implicated in metabolic regulation and β-cell proliferation. Although in vitro studies have suggested that ChREBP promotes glucose-stimulated β-cell proliferation, its in vivo role under physiological and pathophysiological conditions remains unclear.

Materials and Methods

We generated β-cell-specific ChREBP knockout (βChrebp cKO) mice and examined β-cell proliferation and glucose metabolism under three conditions known to induce β-cell expansion: pharmacologically induced insulin resistance using the insulin receptor antagonist S961, high-fat diet (HFD) feeding, and pregnancy. β-cell proliferation was assessed by 5-Bromo-2′-deoxyuridine incorporation; islet gene expression was evaluated by quantitative PCR and RNA sequencing.

Results

βChrebp cKO mice displayed significantly impaired β-cell proliferation under both S961 treatment and HFD feeding, accompanied by decreased expression of the ChREBP target gene Rgs16. These mice also exhibited a mild defect in early-phase insulin secretion at 1 year of age and developed age-associated glucose intolerance. In contrast, pregnancy-induced β-cell proliferation and the expression of mitogenic genes (e.g., Tph2, Ccnb1, Ccnb2) were preserved in βChrebp cKO mice, and Rgs16 expression was unaffected. These findings suggest that ChREBP is critical for β-cell adaptation under hyperglycemia and insulin-resistant states, but not during normoglycemic pregnancy.

Conclusions

ChREBP plays a context-dependent role in regulating β-cell proliferation, particularly under metabolic stress. The ChREBP–RGS16 axis may mediate adaptive β-cell proliferation in diabetes-related conditions, and this axis represents a potential therapeutic target to preserve or restore β-cell mass in type 2 diabetes.

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