This article presents a simplified view of integrins with emphasis on the α4 (α4β1/VLA-4) integrin. Integrins are heterodimeric proteins expressed on the cell surface of leukocytes that participate in a wide variety of functions, such as survival, growth, differentiation, migration, inflammatory responses, tumour invasion, among others. When the extracellular matrix is degraded or deformed, cells are forced to undergo responsive changes that influence remodelling during physiological and pathological events. Integrins recognize these changes and trigger a series of cellular responses, forming a physical connection between the interior and the outside of the cell. The communication of integrins through the plasma membrane occurs in both directions, from the extracellular to the intracellular (outside-in) and from the intracellular to the extracellular (inside-out). Integrins are valid targets for antibodies and small-molecule antagonists. One example is the monoclonal antibody natalizumab, marketed under the name of TYSABRI®, used in the treatment of recurrent multiple sclerosis, which inhibits the adhesion of α4 integrin to its counter-receptor. α4β1 Integrin antagonists are summarized here, and their utility as therapeutics are also discussed.

本文介绍了整合素的简化视图，重点是 α4 (α4β1/VLA-4) 整合素。整联蛋白是在白细胞细胞表面表达的异二聚体蛋白，参与多种功能，例如存活、生长、分化、迁移、炎症反应、肿瘤侵袭等。当细胞外基质降解或变形时，细胞被迫经历影响生理和病理事件期间重塑的响应性变化。整合素识别这些变化并触发一系列细胞反应，在细胞内部和外部之间形成物理连接。整合素通过质膜的通讯发生在两个方向，从细胞外到细胞内（由外向内）和从细胞内到细胞外（由内向外）。整合素是抗体和小分子拮抗剂的有效靶标。一个例子是单克隆抗体那他珠单抗，以 TYSABRI® 的名义上市，用于治疗复发性多发性硬化症，它抑制 α4 整合素与其反受体的粘附。此处总结了 α4β1 整合素拮抗剂，并讨论了它们作为治疗剂的效用。