Takada Mariko, Pinnawala Uma Chandula, Hirano Shinichi, Imokawa Genji
Center for Bioscience Research and Education, Utsunomiya University, Utsunomiya, Tochigi, Japan.
TourtVert Co, Ltd, Minoh, Osaka, Japan.
J Dermatol. 2025 Jan;52(1):24-34. doi: 10.1111/1346-8138.17520. Epub 2024 Oct 31.
Neprilysin is a skin wrinkle-inducing membrane bound elastase that is expressed abundantly in UV-exposed and in aged dermal fibroblasts. The overexpression of neprilysin is closely associated with enhanced epithelial-mesenchymal cytokine interactions mainly via interleukin (IL)-1α, which has the distinct potential to stimulate the expression of neprilysin by human dermal fibroblasts (HDFs). The over-expression of neprilysin also accelerates the formation of wrinkles, accompanied by disruptions of the three-dimensional architecture of dermal elastic fibers that are responsible for the loss of skin elasticity. Because the signaling pathway(s) that lead to the IL-1α-stimulated expression of neprilysin in HDFs remain unclear, we characterized the signaling pathway involved, including their related transcription factors, in IL-1α-treated HDFs. Since qRT-PCR analysis revealed that the mRNA expression level of neprilysin is stimulated to a stronger extent in adult HDFs (aHDFs) by IL-1α than in neonatal HDFs, we used aHDFs for the signaling analysis. Western blotting analysis of the phosphorylation of signaling factors revealed that IL-1α significantly stimulated the phosphorylation of ERK1/2, RSK, JNK, p38, MSK1, NFkB, c-Jun, ATF-2, CREB, and STAT3. Analysis using various signaling inhibitors demonstrated that inhibiting ERK and JNK but not p38, MSK1, NFkB, or STAT3 significantly abrogated the IL-1α stimulated expression of neprilysin at the mRNA, protein, and enzyme activity levels. Furthermore, silencing c-Fos significantly down-regulated the IL-1α-increased expression of neprilysin at the protein and enzyme activity levels. These findings strongly suggest that the IL-1α-stimulated expression of neprilysin in aHDFs is mediated via the intracellular signaling axis of ERK/JNK/c-Jun/c-Fos/AP-1.
中性肽链内切酶是一种诱导皮肤皱纹的膜结合弹性蛋白酶，在紫外线照射的皮肤和衰老的真皮成纤维细胞中大量表达。中性肽链内切酶的过表达主要通过白细胞介素（IL）-1α与上皮-间充质细胞因子相互作用增强密切相关，IL-1α具有刺激人真皮成纤维细胞（HDFs）表达中性肽链内切酶的独特潜力。中性肽链内切酶的过表达还会加速皱纹的形成，同时伴随着负责皮肤弹性丧失的真皮弹性纤维三维结构的破坏。由于导致IL-1α刺激HDFs表达中性肽链内切酶的信号通路尚不清楚，我们对IL-1α处理的HDFs中涉及的信号通路及其相关转录因子进行了表征。由于qRT-PCR分析显示，IL-1α刺激成人HDFs（aHDFs）中中性肽链内切酶的mRNA表达水平比新生儿HDFs更强，因此我们使用aHDFs进行信号分析。对信号因子磷酸化的蛋白质印迹分析表明，IL-1α显著刺激ERK1/2、RSK JNK、p38、MSK1、NFkB、c-Jun、ATF-2、CREB和STAT 的磷酸化分析使用各种信号抑制剂表明，抑制ERK 和JNK 而非p38、MSK1、NFkB 或STAT 显著消除了IL-1α在mRNA、蛋白质和酶活性水平上刺激的中性肽链内切酶表达。此外，沉默c-Fos 显著下调了IL-1α在蛋白质和酶活性水平上增加的中性肽链内切酶表达。这些发现强烈表明，IL-1α刺激aHDFs中中性肽链内切酶的表达是通过ERK/JNK/c-Jun/c-Fos/AP-1的细胞内信号轴介导的。
