Department of Dermatology, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Medical Centre (Radboudumc), Nijmegen, The Netherlands.
Dermatology. 2017;233(2-3):155-163. doi: 10.1159/000477346. Epub 2017 Jul 8.
Defensins are antimicrobial peptides that exert immunomodulatory and chemotactic functions. Based on these properties and their high expression levels in the skin, they are likely to affect skin inflammation, infection, and wound healing. This may lead to therapeutic applications in (burn) wound healing.
We aimed to investigate the effects of human β-defensins (hBDs) on keratinocytes and fibroblasts, 2 major skin cell types involved in skin regeneration.
Monolayer keratinocyte and fibroblast cultures were exposed to recombinant hBDs, and we overexpressed hBD2 and hBD3 in keratinocytes of reconstructed epidermal equivalents by lentiviral transduction. The effects were measured by immunohistochemistry, quantitative real-time PCR, and migration assays. Kinome analyses were performed on cultured keratinocytes to investigate the signal transduction events elicited by hBD stimulation.
We found that hBD3 induced the expression of cytokines and chemokines in keratinocytes, which was not observed in fibroblasts. hBD2, however, stimulated cell migration only in fibroblasts, which was not found for hBD3. Both defensins are likely to exert receptor-mediated effects in keratinocytes, as witnessed by changes in protein kinase activation following stimulation by hBD2 and hBD3. Kinome analysis suggested that protein kinase C activation was a common event for both defensins. We observed, however, considerable differences in keratinocyte responses between stimulation by exogenous recombinant defensins and endogenous defensins expressed following lentiviral transduction.
Defensins exert modest biological effects on skin cells that are potentially beneficial in wound healing, but many questions regarding the biological mechanisms of action and relevance for the in vivo situation are still remaining.
防御素是具有免疫调节和趋化作用的抗菌肽。基于这些特性及其在皮肤中的高表达水平，它们可能会影响皮肤炎症、感染和伤口愈合。这可能导致（烧伤）伤口愈合的治疗应用。
我们旨在研究人β-防御素（hBDs）对参与皮肤再生的 2 种主要皮肤细胞类型——角质形成细胞和成纤维细胞的影响。
单层角质形成细胞和成纤维细胞培养物暴露于重组 hBDs 中，并通过慢病毒转导在重建的表皮等效物中的角质形成细胞中过表达 hBD2 和 hBD3。通过免疫组织化学、定量实时 PCR 和迁移测定来测量效应。对培养的角质形成细胞进行激酶组分析，以研究 hBD 刺激引发的信号转导事件。
我们发现 hBD3 诱导角质形成细胞中细胞因子和趋化因子的表达，而在成纤维细胞中未观察到这种情况。然而，hBD2 仅刺激成纤维细胞的细胞迁移，而在 hBD3 中未发现这种情况。两种防御素都可能在角质形成细胞中发挥受体介导的作用，这可以通过 hBD2 和 hBD3 刺激后蛋白激酶激活的变化来证明。激酶组分析表明，蛋白激酶 C 的激活是两种防御素的共同事件。然而，我们观察到，外源性重组防御素刺激和慢病毒转导后内源性防御素表达对角质形成细胞的反应存在相当大的差异。
防御素对皮肤细胞产生适度的生物学效应，这可能对伤口愈合有益，但关于作用的生物学机制及其与体内情况的相关性仍存在许多问题。
