Clark R A, Ashcroft G S, Spencer M J, Larjava H, Ferguson M W
Department of Dermatology, School of Medicine, SUNY at Stony Brook 11794-8165, USA.
Br J Dermatol. 1996 Jul;135(1):46-51.
During cutaneous wound repair, keratinocytes move laterally across the wound surface. For this lateral movement epidermal cells must disassemble their tenacious connections to the basement membrane and their neighbouring cells, and express surface receptors that permit translocation over the wound surface extracellular matrix. If the basement membrane is disrupted, the epidermis migrates over a provisional matrix that contains fibrinogen, fibronectin, vitronectin and tenascin. Although alpha 5 beta 1 integrin, a fibronectin receptor, is expressed by human epidermis during re-epithelialization of excisional and incisional wounds, the spatial and temporal patterns of vitronectin, tenascin, and other fibronectin receptors are less clear. Other potential receptors include alpha v beta 5 for vitronectin and alpha v beta 6 for fibronectin and tenascin. To study provisional matrix integrin expression during human wound healing, full-thickness 4-mm punch biopsies were performed on the inner surface of the upper arm in adult volunteers. At 3, 7 and 14 days after injury wound sites were excised, bisected, quick frozen in liquid nitrogen, and examined for the expression of alpha 5, beta 1, alpha v, beta 5 and beta 6. At 3 days, alpha 5 beta 1 and alpha v beta 5, but not alpha v beta 6, appeared around the basal and suprabasalar cells of the migrating epidermis. At 7 days, alpha 5 beta 1, alpha v beta 5, and alpha v beta 6 appeared around the perimeter of the basal cells of the migrating epidermis. By 14 days, when re-epithelialization was complete, all basal and suprabasalar cells overlying the wound expressed alpha 5 beta 1 and alpha v beta 6, but not alpha v beta 5. Thus, alpha v appeared to switch its heterodimeric association from beta 5 to beta 6 subunit during re-epithelialization.
在皮肤伤口修复过程中，角质形成细胞会横向穿过伤口表面。为了实现这种横向移动，表皮细胞必须分解它们与基底膜以及相邻细胞之间的紧密连接，并表达能够使其在伤口表面细胞外基质上迁移的表面受体。如果基底膜遭到破坏，表皮会在含有纤维蛋白原、纤连蛋白、玻连蛋白和腱生蛋白的临时基质上迁移。虽然在切除性和切开性伤口再上皮化过程中，人表皮会表达纤连蛋白受体α5β1整合素，但其玻连蛋白、腱生蛋白及其他纤连蛋白受体的时空表达模式尚不清楚。其他潜在受体包括针对玻连蛋白的αvβ5和针对纤连蛋白及腱生蛋白的αvβ6。为了研究人类伤口愈合过程中临时基质整合素的表达情况，对成年志愿者上臂内表面进行了4毫米全层打孔活检。在受伤后3天、7天和14天，切除伤口部位，将其对半切开，在液氮中快速冷冻，并检测α5、β1、αv、β5和β6的表达。在3天时，α5β1和αvβ5出现在迁移表皮的基底细胞和基底上层细胞周围，但αvβ6未出现。在7天时，α5β1、αvβ5和αvβ6出现在迁移表皮基底细胞周边。到14天时，再上皮化完成，伤口上方所有基底细胞和基底上层细胞都表达α5β1和αvβ6，但不表达αvβ5。因此，在再上皮化过程中，αv似乎将其异二聚体关联从β5亚基切换到了β6亚基。
