SAAD Centre for Pharmacy and Diabetes, University of Ulster, Coleraine, UK.
Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK.
Diabetes Obes Metab. 2015 Aug;17(8):760-70. doi: 10.1111/dom.12483. Epub 2015 Jun 16.
To examine the biological characteristics of a novel glucagon-like peptide-1 (GLP-1) conjugate, in which an antithrombin III (ATIII)-binding pentasaccharide is conjugated to d-Ala(8) GLP-1 using a tetraethylene glycol linker.
We assessed GLP-1 receptor binding, cAMP generation and insulin secretory activity of the GLP-1 conjugate in vitro. Circulating half-life, glucose homeostatic and subchronic therapeutic effectiveness were then examined in vivo.
The half-life of the GLP-1 conjugate in mice was ∼11 h. In vitro insulin secretion from clonal β cells and islets was increased (p < 0.001) by the conjugate. The conjugate had half maximum effective concentration values of 1.3 × 10(-7) and 9.9 × 10(-8) M for displacement of (125) I-GLP-1 in competitive GLP-1 receptor binding and cAMP generation, respectively. Glucose tolerance in normal mice, immediately and 4 h after conjugate injection, resulted in significant (p < 0.001) improvements in blood glucose. These effects persisted for >48 h after administration. Daily treatment (21 days) of high-fat-fed and ob/ob mice with 25 nmol/kg conjugate resulted in significant improvement in glucose tolerance (p < 0.001) and reductions in glycated haemoglobin (HbA1c; p < 0.01) equivalent to or better than with exenatide or liraglutide. Treatment of C57BL/KsJ db/db mice for 15 days with 100 nmol/kg conjugate significantly (p < 0.001) reduced glucose and raised plasma insulin. Oral glucose tolerance was significantly (p < 0.001) improved and both 24-h glucose profile (p < 0.001) and HbA1c levels (p < 0.001) were reduced. Islet size (p < 0.001) and pancreatic insulin content were increased without change of islet cell proliferation or apoptosis.
These data show that d-Ala(8) GLP-1(Lys(37) ) pentasaccharide exerts significant antidiabetic actions and has a projected pharmacokinetic/pharmacodynamic profile that merits further evaluation in humans for a possible once-weekly dosing regimen.
研究一种新型胰高血糖素样肽-1（GLP-1）缀合物的生物学特性，该缀合物通过四乙二醇接头将抗凝血酶 III（ATIII）结合五聚糖连接到 d-Ala（8）GLP-1 上。
我们评估了 GLP-1 缀合物在体外的 GLP-1 受体结合、cAMP 生成和胰岛素分泌活性。然后在体内检查了循环半衰期、葡萄糖稳态和亚慢性治疗效果。
GLP-1 缀合物在小鼠体内的半衰期约为 11 小时。来自克隆β细胞和胰岛的胰岛素分泌在体外（p<0.001）被缀合物增加。该缀合物对（125）I-GLP-1 的竞争 GLP-1 受体结合和 cAMP 生成的半最大有效浓度值分别为 1.3×10(-7)和 9.9×10(-8)M。正常小鼠在注射缀合物后即刻和 4 小时内的葡萄糖耐量导致血糖显著（p<0.001）改善。这些作用在给药后持续超过 48 小时。用 25nmol/kg 缀合物对高脂肪喂养和 ob/ob 小鼠进行每日治疗（21 天）导致葡萄糖耐量显著（p<0.001）改善，糖化血红蛋白（HbA1c；p<0.01）降低与 exenatide 或 liraglutide 相当或更好。用 100nmol/kg 缀合物治疗 C57BL/KsJ db/db 小鼠 15 天，显著（p<0.001）降低血糖并升高血浆胰岛素。口服葡萄糖耐量显著（p<0.001）改善，24 小时血糖谱（p<0.001）和 HbA1c 水平（p<0.001）降低。胰岛大小（p<0.001）和胰腺胰岛素含量增加，而胰岛细胞增殖或凋亡无变化。
这些数据表明，d-Ala（8）GLP-1（Lys（37））五聚糖发挥显著的抗糖尿病作用，并且具有预期的药代动力学/药效学特征，值得进一步在人类中评估，以可能实现每周一次的给药方案。
