Expression and regulation of facilitative glucose transporters in equine insulin-sensitive tissue: from physiology to pathology.
Expression and regulation of facilitative glucose transporters in equine insulin-sensitive tissue: from physiology to pathology.
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DOI：
10.1155/2014/409547
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Lacombe VA
中科院分区：
文献类型：
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作者：
Lacombe VA
葡萄糖摄取是葡萄糖利用中的限速步骤，并且受到称为易化葡萄糖转运蛋白（GLUT/SLC 2）的一系列专门蛋白质的严格调节。GLUT 4是胰岛素应答组织中的主要同种型，从细胞内库易位至细胞表面，并因此决定胰岛素刺激的葡萄糖摄取。然而，尽管经过50多年的深入研究，但在任何物种中都没有完全阐明介导GLUT 4易位的胰岛素依赖性和非依赖性途径。胰岛素抵抗（IR）是马代谢综合征的标志之一，也是马蹄叶炎最常见的代谢易感因素。IR的特征在于胰岛素刺激葡萄糖进入胰岛素敏感组织的能力受损。与其他种属相似，马IR期间肌肉和脂肪组织中胰岛素应答GLUT的功能能力受损。然而，改变葡萄糖转运的分子机制在所有物种中仍然难以捉摸，并且仍然有很多关于GLUT家族成员的生理和病理生理功能的研究，特别是关于III类。由于GLUT是全身葡萄糖稳态的关键调节剂，因此它们作为治疗人类和马患者代谢紊乱的潜在治疗靶点受到了相当大的关注。
Glucose uptake is the rate-limiting step in glucose utilization in mammalians and is tightly regulated by a family of specialized proteins, called the facilitated glucose transporters (GLUTs/SLC2). GLUT4, the major isoform in insulin-responsive tissue, translocates from an intracellular pool to the cell surface and as such determines insulin-stimulated glucose uptake. However, despite intensive research over 50 years, the insulin-dependent and -independent pathways that mediate GLUT4 translocation are not fully elucidated in any species. Insulin resistance (IR) is one of the hallmarks of equine metabolic syndrome and is the most common metabolic predisposition for laminitis in horses. IR is characterized by the impaired ability of insulin to stimulate glucose disposal into insulin-sensitive tissues. Similar to other species, the functional capability of the insulin-responsive GLUTs is impaired in muscle and adipose tissue during IR in horses. However, the molecular mechanisms of altered glucose transport remain elusive in all species, and there is still much to learn about the physiological and pathophysiological functions of the GLUT family members, especially in regard to class III. Since GLUTs are key regulators of whole-body glucose homeostasis, they have received considerable attention as potential therapeutic targets to treat metabolic disorders in human and equine patients.