Götz Lisa, Rueckschloss Uwe, Reimer Andreas, Bömmel Heike, Beilhack Andreas, Ergün Süleyman, Kleefeldt Florian
Institute of Anatomy and Cell Biology, University of Wuerzburg, Wuerzburg, Germany.
Department of Internal Medicine II, University Hospital Wuerzburg, Wuerzburg, Germany.
Aging Cell. 2025 Feb;24(2):e14384. doi: 10.1111/acel.14384. Epub 2024 Oct 21.
Chronic inflammation with progressive age, called inflammaging, contributes to the pathogenesis of cardiovascular diseases. Previously, we have shown increased vascular expression of the Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) in aged mice and humans, presumably via mutual upregulation with the pro-inflammatory cytokine TNF-α. CEACAM1 is critical for aging-associated vascular alterations like endothelial dysfunction, fibrosis, oxidative stress, and sustained inflammation and can be regarded as a main contributor to vascular inflammaging. This study was conducted to elucidate the mechanisms underlying endothelial CEACAM1 upregulation by TNF-α in detail. Using wildtype (WT) and TNF-α knockout (Tnf) mice, we confirmed that the aging-related upregulation of endothelial CEACAM1 critically depends on TNF-α. The underlying mechanisms were analyzed in an endothelial cell culture model. TNF-α time-dependently upregulated CEACAM1 in vitro. In pharmacological experiments, we identified an early NF-κB- and a delayed β-catenin-mediated response. Involvement of β-catenin was further substantiated by siRNA-mediated knockdown of the β-catenin-targeted transcription factor TCF4. Both signaling pathways acted independent from each other. Elucidating the delayed response, co-immunoprecipitation analysis revealed release of β-catenin from adherens junctions by TNF-α. Finally, TNF-α activated Akt kinase by increasing its Ser phosphorylation. Consequently, Akt kinase facilitated β-catenin signaling by inhibiting its degradation via phosphorylation of GSK3β at Ser and by increased phosphorylation of β-catenin at Ser that augments its transcriptional activity. Taken together, our study provides novel mechanistic insights into the aging-related, inflammation-mediated endothelial upregulation of CEACAM1. Beyond the pathogenesis of cardiovascular diseases, these findings may be significant to all fields of inflammaging.
随着年龄增长而出现的慢性炎症，即炎症衰老，会促进心血管疾病的发病机制。此前，我们已经表明，在老年小鼠和人类中，癌胚抗原相关细胞粘附分子1（CEACAM1）的血管表达增加，推测是通过与促炎细胞因子TNF-α相互上调实现的。CEACAM1对于与衰老相关的血管改变至关重要，如内皮功能障碍、纤维化、氧化应激和持续炎症，可被视为血管炎症衰老的主要促成因素。本研究旨在详细阐明TNF-α上调内皮CEACAM1的潜在机制。使用野生型（WT）和TNF-α基因敲除（Tnf）小鼠，我们证实内皮CEACAM1与衰老相关的上调关键取决于TNF-α。在内皮细胞培养模型中分析了潜在机制。TNF-α在体外呈时间依赖性地上调CEACAM1。在药理学实验中，我们确定了早期的NF-κB介导反应和延迟的β-连环蛋白介导反应。通过siRNA介导敲低β-连环蛋白靶向转录因子TCF4，进一步证实了β-连环蛋白的参与。这两种信号通路相互独立作用。为了阐明延迟反应，免疫共沉淀分析显示TNF-α使β-连环蛋白从粘着连接中释放出来。最后，TNF-α通过增加其丝氨酸磷酸化激活Akt激酶。因此，Akt激酶通过抑制GSK3β丝氨酸磷酸化介导的β-连环蛋白降解以及增加β-连环蛋白丝氨酸磷酸化增强其转录活性，从而促进β-连环蛋白信号传导。综上所述，我们的研究为衰老相关的、炎症介导的内皮CEACAM1上调提供了新的机制见解。除了心血管疾病的发病机制外,这些发现可能对炎症衰老的所有领域都具有重要意义。
