Department of Bioengineering, College of Engineering, and BK21 PLUS Future Biopharmaceutical Human Resources Training and Research Team, Hanyang University, Seoul 04763, Republic of Korea.
Department of Chemical and Biological Engineering, Korea National University of Transportation, Chungju 27469, Republic of Korea.
J Control Release. 2017 Jan 28;246:155-163. doi: 10.1016/j.jconrel.2016.12.028. Epub 2016 Dec 28.
Although pancreatic islet implantation is an attractive strategy for curing diabetes mellitus, implanted cells are immunologically eliminated due to early islet graft loss. One of main issues in early islet graft loss is the secretion of high-mobility group-box-1 (HMGB1) protein from the damaged islet cells, which is known as a cytokine-like factor. Therefore, regulating the activity of HMGB1 protein offers an alternative strategy for improving outcomes of islet cell therapy. To this end, we first demonstrated that HMGB1 protein could be bound to its A-box fragment (HMGB1 A-box) with higher binding affinity, resembling anti-HMGB1 antibody. To be used as a pharmaceutical protein ex vivo, TAT-labeled HMGB1 A-box-His (TAT-HMGB1A) was structurally modified for cellular membrane penetration. TAT-HMGB1A significantly reduced secretion of endogenous HMGB1 protein through interaction in the cytosol without any damage to the viability or functionality of the islets. When TAT-HMGB1A-treated islets were implanted into diabetic nude mice, they completely cured diabetes, as evidenced by stable blood glucose level. TAT-HMGB1A treatment could also reduce the marginal islet mass needed to cure diabetes. Furthermore, TAT-HMGB1A positively protected xenotransplanted islets from xenogeneic immune reactions. Collectively, cell-penetrable TAT-HMGB1A could be used to modulate HMGB1 activity to increase successful outcomes of ex vivo pancreatic islet cell therapy.
尽管胰岛细胞移植是治疗糖尿病的一种有吸引力的策略，但由于早期胰岛移植物丢失，植入的细胞会被免疫消除。早期胰岛移植物丢失的一个主要问题是受损胰岛细胞分泌高迁移率族蛋白 B1（HMGB1）蛋白，这种蛋白被认为是一种细胞因子样因子。因此，调节 HMGB1 蛋白的活性为改善胰岛细胞治疗的结果提供了一种替代策略。为此，我们首先证明 HMGB1 蛋白可以与 A 盒片段（HMGB1 A 盒）结合，具有更高的结合亲和力，类似于抗 HMGB1 抗体。为了在体外作为一种药物蛋白使用，对 TAT 标记的 HMGB1 A 盒-组氨酸（TAT-HMGB1A）进行结构修饰以穿透细胞膜。TAT-HMGB1A 通过与细胞质中的内源性 HMGB1 蛋白相互作用，在不损害胰岛活力或功能的情况下，显著减少其分泌。当 TAT-HMGB1A 处理的胰岛被植入糖尿病裸鼠体内时，它们完全治愈了糖尿病，这表现为血糖水平稳定。TAT-HMGB1A 治疗还可以减少治愈糖尿病所需的胰岛边缘质量。此外，TAT-HMGB1A 还能正向保护异种移植的胰岛免受异种免疫反应的影响。总之，具有细胞穿透能力的 TAT-HMGB1A 可用于调节 HMGB1 活性，以增加体外胰岛细胞治疗的成功结果。
