Leguina-Ruzzi Alberto, Valderas Juan P
Juntendo University, School of Medicine , Tokyo, Japan.
Departamento de Ciencias Médicas, Facultad de Medicina Odontología, Universidad de Antofagasta , Antofagasta, Chile.
Dermatoendocrinol. 2016 Dec 14;9(1):e1267078. doi: 10.1080/19381980.2016.1267078. eCollection 2017.
Type 2 diabetes (T2D) can go undiagnosed for years, leading to a stage where chronic high blood sugar produces complications such as delayed wound healing. Reports have shown that BLT2 activation improves keratinocyte migration and wound healing, as well as protecting the epidermal barrier through the promotion of actin polymerization. The goal of this study was to elucidate the role of BLT2 expression in skin epithelial integrity in T2D. For this purpose, we used both wild type (WT) and BLT2 knockout mice in a model, in which a T2D-like phenotype was induced by keeping the animals on a high fat (HF) diet over 5 weeks. In a parallel approach, we cultured BLT2-transfected HaCaT cells at both low and high glucose concentrations for 48 h. Structure, transepithelial resistance (TEER), IL-1ß, IL-8 or CXCL2, MMP9, Filaggrin, Loricrin and Keratin 10 (K10) were evaluated and . Additionally, wound healing (WH) was studied . The skin from T2D and BLT2 knockout mice showed a reduction in TEER and the expression of IL-1ß, and in increase in CXCL2, MMP9, Filaggrin, Loricrin and K10 expression. The structure suggested an atrophic epidermis; however, the skin was dramatically affected in the BLT2 knockout mice kept on a HF diet. HaCaT-BLT2 cells presented as an organized monolayer and showed higher TEER and wound healing compared with vector only-transfected HaCaT-Mock cells. Likewise, alterations in the expression of skin inflammatory, matrix degradation and differentiation markers under low and high glucose conditions were less severe than in HaCaT-Mock cells. Our results suggest that BLT2 improves epithelial integrity and function by regulating differentiation markers, cytokines and MMP9. Furthermore, BLT2 attenuates the damaging effects of high glucose levels, thereby accelerating wound healing.
2型糖尿病（T2D）可能多年未被诊断出来，从而发展到慢性高血糖引发诸如伤口愈合延迟等并发症的阶段。报告显示，BLT2激活可改善角质形成细胞迁移和伤口愈合，并通过促进肌动蛋白聚合来保护表皮屏障。本研究的目的是阐明BLT2表达在T2D皮肤上皮完整性中的作用。为此，我们在一个模型中使用了野生型（WT）和BLT2基因敲除小鼠，该模型通过让动物食用高脂肪（HF）饮食5周来诱导出类似T2D的表型。同时，我们在低葡萄糖和高葡萄糖浓度下将转染了BLT2的HaCaT细胞培养48小时。评估了结构、跨上皮电阻（TEER）、白细胞介素-1β（IL-1β）、白细胞介素-8（IL-8）或CXC趋化因子配体2（CXCL2）、基质金属蛋白酶9（MMP9）、丝聚蛋白、兜甲蛋白和角蛋白10（K10）。此外，还研究了伤口愈合（WH）情况。T2D小鼠和BLT2基因敲除小鼠的皮肤显示TEER降低以及IL-1β表达减少，而CXCL2、MMP9、丝聚蛋白、兜甲蛋白和K10表达增加。结构显示表皮萎缩；然而，食用HF饮食的BLT2基因敲除小鼠的皮肤受到的影响更为显著。与仅转染载体的HaCaT-Mock细胞相比，HaCaT-BLT2细胞呈现为有组织的单层，并且显示出更高的TEER和伤口愈合能力。同样，在低葡萄糖和高葡萄糖条件下皮肤炎症、基质降解和分化标志物表达的变化比HaCaT-Mock细胞中的情况要轻。我们的结果表明，BLT2通过调节分化标志物、细胞因子和MMP9来改善上皮完整性和功能。此外，BLT2减弱了高葡萄糖水平的破坏作用，从而加速伤口愈合。
