PDF(Pubmed)
Abstract：
Aging is associated with a decline in the functionality of various cell types, including dermal fibroblasts, which play a crucial role in maintaining skin homeostasis and wound healing. Chronic inflammation and increased reactive oxygen species (ROS) production are hallmark features of aging, contributing to impaired wound healing. MicroRNA-146a (miR-146a) has been implicated as a critical regulator of inflammation and oxidative stress in different cell types, yet its role in aged dermal fibroblasts and its potential relevance to wound healing remains poorly understood. We hypothesize that miR-146a is differentially expressed in aged dermal fibroblasts and that overexpression of miR-146a will decrease aging-induced inflammatory responses and ROS production. Primary dermal fibroblasts were isolated from the skin of 17-week-old (young) and 88-week-old (aged) mice. Overexpression of miR-146a was achieved through miR-146a mimic transfection. ROS were detected using a reliable fluorogenic marker, 2,7-dichlorofluorescin diacetate. Real-time PCR was used to quantify relative gene expression. Our investigation revealed a significant reduction in miR-146a expression in aged dermal fibroblasts compared to their younger counterparts. Moreover, aged dermal fibroblasts exhibited heightened levels of inflammatory responses and increased ROS production. Importantly, the overexpression of miR-146a through miR-146a mimic transfection led to a substantial reduction in inflammatory responses through modulation of the NF-kB pathway in aged dermal fibroblasts. Additionally, the overexpression of miR-146a led to a substantial decrease in ROS production, achieved through the downregulation of NOX4 expression in aged dermal fibroblasts. These findings underscore the pivotal role of miR-146a in mitigating both inflammatory responses and ROS production in aged dermal fibroblasts, highlighting its potential as a therapeutic target for addressing age-related skin wound healing.
摘要：
衰老与各种细胞类型的功能下降有关，包括真皮成纤维细胞，在维持皮肤稳态和伤口愈合中起着至关重要的作用。慢性炎症和活性氧（ROS）产生增加是衰老的标志特征，导致伤口愈合受损。MicroRNA-146a（miR-146a）被认为是不同细胞类型中炎症和氧化应激的关键调节因子。然而，它在老年真皮成纤维细胞中的作用及其与伤口愈合的潜在相关性仍然知之甚少。我们假设miR-146a在老化的真皮成纤维细胞中差异表达，并且miR-146a的过表达将减少老化诱导的炎症反应和ROS产生。从17周龄(年轻)和88周龄(老年)小鼠的皮肤分离原代真皮成纤维细胞。通过miR-146a模拟物转染实现miR-146a的过表达。使用可靠的荧光标记检测ROS，2,7-二氯荧光素二乙酸酯。实时PCR用于定量相对基因表达。我们的研究显示，与较年轻的成纤维细胞相比，老年真皮成纤维细胞中miR-146a的表达显着降低。此外，老年真皮成纤维细胞表现出炎症反应水平升高和ROS产生增加。重要的是,miR-146a通过miR-146a模拟转染的过表达导致老年真皮成纤维细胞中通过调节NF-kB途径的炎症反应显著减少.此外,miR-146a的过表达导致ROS产生的大幅减少，通过下调NOX4在老年真皮成纤维细胞中的表达来实现。这些发现强调了miR-146a在减轻老化真皮成纤维细胞的炎症反应和ROS产生中的关键作用。强调其作为解决与年龄相关的皮肤伤口愈合的治疗目标的潜力。
