School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou, China.
Department of Pharmacy, Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou, China.
J Periodontal Res. 2022 Aug;57(4):859-868. doi: 10.1111/jre.13024. Epub 2022 Jun 13.
Endothelial progenitor cells (EPCs) function as the angiogenic switch of many physiological and pathological conditions. We aimed to investigate the effects of Porphyromonas gingivalis lipopolysaccharide on the angiogenic capacity of EPCs and delineate the underlying mechanisms.
EPCs were isolated from human umbilical blood. CCK-8 assay was undertaken to analyze the cell viability. The migration and tube formation capacity were assessed by wound healing and tube formation, respectively. The protein expression of Akt/p-Akt, endothelial nitric oxide synthase (eNOS)/p-eNOS, and Forkhead box O1 (FoxO1)/p-FoxO1 was determined by Western blot. The intracellular localization of FoxO1 was evaluated by immunofluorescent staining.
P. gingivalis LPS at 10 μg/ml significantly increased the viability (10.9 ± 2.9%), migration (16.3 ± 3.1%), and tube formation (38.6 ± 5.5%) of EPCs, along with increased phosphorylation of Akt, eNOS, and FoxO1. Mechanistically, Akt inhibition by specific inhibitor wortmannin and FoxO1 forced expression by adenovirus transfection in EPCs markedly attenuated the P. gingivalis LPS-induced eNOS activation, tube formation, and migration. Moreover, P. gingivalis LPS-induced phosphorylation and nuclear exclusion of FoxO1 were blunted by Akt inhibition.
The present study suggests that P. gingivalis LPS could affect the angiogenic function of EPCs through the Akt/FoxO1 signaling. The current findings may shed light on the clinical association of periodontitis with aberrant angiogenesis seen in atherosclerotic plaque rupture.
内皮祖细胞（EPCs）是许多生理和病理状态下血管生成的关键。本研究旨在探讨牙龈卟啉单胞菌脂多糖（P. gingivalis LPS）对 EPCs 血管生成能力的影响，并阐明其潜在机制。
从人脐血中分离 EPCs。通过 CCK-8 法分析细胞活力。通过划痕愈合和管形成实验分别评估迁移和管形成能力。通过 Western blot 检测 Akt/p-Akt、内皮型一氧化氮合酶（eNOS）/p-eNOS 和叉头框蛋白 O1（FoxO1）/p-FoxO1 的蛋白表达。通过免疫荧光染色评估 FoxO1 的细胞内定位。
10μg/ml 的 P. gingivalis LPS 显著增加 EPCs 的活力（10.9±2.9%）、迁移（16.3±3.1%）和管形成（38.6±5.5%），同时增加 Akt、eNOS 和 FoxO1 的磷酸化。机制上，EPCs 中 Akt 特异性抑制剂wortmannin 的抑制作用和腺病毒转染强制表达 FoxO1 显著减弱了 P. gingivalis LPS 诱导的 eNOS 激活、管形成和迁移。此外，Akt 抑制作用减弱了 P. gingivalis LPS 诱导的 FoxO1 磷酸化和核排斥。
本研究表明，P. gingivalis LPS 可能通过 Akt/FoxO1 信号通路影响 EPCs 的血管生成功能。本研究结果可能为牙周炎与动脉粥样硬化斑块破裂时异常血管生成的临床相关性提供依据。
