Chronic, non-healing skin wounds such as diabetic foot ulcers (DFUs) are common in patients with type 2 diabetes. Here, we investigated the role of chemokine CCL28 and its receptor CCR10 in downregulation of endothelial nitric oxide synthase (eNOS) in association with delayed skin wound healing in the db/db mouse model of type 2 diabetes. We observed reduced eNOS expression and elevated CCL28/CCR10 levels in dorsal skin of db/db mice and subdermal leg biopsies from human subjects with type 2 diabetes. Further interrogation revealed that overexpression of CCR10 reduced eNOS expression, NO bioavailability, and tube formation of human dermal microvascular endothelial cells (HDMVECs) in vitro which was recapitulated in mouse dorsal skin. In addition, incubation of HDMVECs with CCL28 led to internalization of the CCR10/eNOS complex and co-localization with lysosome-associated membrane protein-1. Finally, topical application of myristoylated CCR10 binding domain 7 amino acid (Myr-CBD7) peptide prevented CCR10-eNOS interaction and subsequent eNOS downregulation, enhanced eNOS/NO levels, eNOS/VEGF-R2+ microvessel density, and blood perfusion, reduced inflammatory cytokine levels, and importantly, decreased wound healing time in db/db mice. Thus, endothelial cell CCR10 activation in genetically obese mice with type 2 diabetes promotes eNOS depletion and endothelial dysfunction, and targeted disruption of CCR10/eNOS interaction improves wound healing.

中文翻译：

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抑制 CCL28/CCR10 介导的 eNOS 下调可改善肥胖诱导的 2 型糖尿病小鼠模型的皮肤伤口愈合


慢性、不愈合的皮肤伤口，如糖尿病足溃疡 (DFU)，在 2 型糖尿病患者中很常见。在这里，我们研究了趋化因子 CCL28 及其受体 CCR10 在 2 型糖尿病 db/db 小鼠模型中内皮一氧化氮合酶 (eNOS) 下调与皮肤伤口愈合延迟相关中的作用。我们观察到 db/db 小鼠的背部皮肤和 2 型糖尿病人类受试者的皮下腿部活检中 eNOS 表达减少，CCL28/CCR10 水平升高。进一步的研究表明，CCR10 的过度表达会降低体外人真皮微血管内皮细胞 (HDMVEC) 的 eNOS 表达、NO 生物利用度和管形成，这在小鼠背部皮肤中得到了重现。此外，HDMVEC 与 CCL28 一起孵育导致 CCR10/eNOS 复合物内化并与溶酶体相关膜蛋白 1 共定位。最后，局部应用肉豆蔻酰化 CCR10 结合域 7 氨基酸 (Myr-CBD7) 肽可防止 CCR10-eNOS 相互作用和随后的 eNOS 下调，增强 eNOS/NO 水平、eNOS/VEGF-R2+ 微血管密度和血液灌注，降低炎症细胞因子水平更重要的是，减少了 db/db 小鼠的伤口愈合时间。因此，患有 2 型糖尿病的遗传性肥胖小鼠的内皮细胞 CCR10 激活会促进 eNOS 耗竭和内皮功能障碍，并且有针对性地破坏 CCR10/eNOS 相互作用可改善伤口愈合。