Department of Endocrinology and Metabolism, Guangzhou Red Cross Hospital, Jinan University, Guangzhou 510220, China.
Department of Endocrinology and Metabolism, The First Affiliated Hospital, Bengbu Medical College, Bengbu 233099, China.
Diabetes Res Clin Pract. 2022 Apr;186:109831. doi: 10.1016/j.diabres.2022.109831. Epub 2022 Mar 16.
To elucidate the relationship between advanced glycation end products (AGEs), Notch1 signaling, nuclear factor-kappa B (NF-κB), and matrix metalloproteinase-9 (MMP-9) in diabetic wound healing in vitro and in vivo.
We incubated primary keratinocytes with AGEs alone or AGEs along with γ-secretase inhibitor DAPT, and established diabetic rat wound model by intraperitoneal streptozotocin treatment. The Notch1 signaling components and MMP-9 expression were detected by qPCR, western blotting and gelatin zymography.
The exposure of primary keratinocytes to AGEs led to a significant increase in Notch intracellular domain (NICD), Delta-like 4 (Dll4), and Hes1; however, Notch1 expression was inhibited by the RAGE siRNA. Furthermore, MMP-9 activation was up-regulated, secondary to AGEs treatment. In contrast, increased MMP-9 expression by AGEs-stimulation was eliminated after treatment with DAPT. NF-κB activation participated in the Notch1-modulated MMP-9 expression. Notably, in the diabetic animal model, inhibition of the Notch signaling pathway with DAPT attenuated NICD and MMP-9 overexpression, improved collagen accumulation, and ultimately accelerated diabetic wound healing.
These findings identified that activation of the Notch1/NF-κB/MMP-9 pathway, in part, mediates the repressive effects of AGEs on diabetic wound healing and that targeting this pathway may be a potential strategy to improve impaired diabetic wound healing.
阐明糖尿病创面愈合过程中细胞外基质金属蛋白酶 9（MMP-9）与晚期糖基化终产物（AGEs）、Notch1 信号通路、核转录因子-κB（NF-κB）之间的关系。
我们将原代角质形成细胞分别用 AGEs 或 AGEs 与 γ-分泌酶抑制剂 DAPT 孵育，并通过腹腔注射链脲佐菌素建立糖尿病大鼠创面模型。采用 qPCR、western blot 和明胶酶谱法检测 Notch1 信号通路相关分子和 MMP-9 的表达。
AGEs 处理原代角质形成细胞后，Notch 细胞内结构域（NICD）、Delta-like 4（Dll4）和 Hes1 表达明显增加，但 RAGE siRNA 抑制了 Notch1 表达。此外，AGEs 处理还可上调 MMP-9 的激活。相反，用 DAPT 处理后，AGEs 刺激引起的 MMP-9 表达增加被消除。NF-κB 的激活参与了 Notch1 调节的 MMP-9 表达。值得注意的是，在糖尿病动物模型中，用 DAPT 抑制 Notch 信号通路可减弱 NICD 和 MMP-9 的过度表达，促进胶原积累，最终加速糖尿病创面愈合。
这些发现表明，Notch1/NF-κB/MMP-9 通路的激活部分介导了 AGEs 对糖尿病创面愈合的抑制作用，靶向该通路可能是改善受损糖尿病创面愈合的一种潜在策略。
