Department of Periodontology, School of Stomatology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, No. 639 Zhizaoju Road, Shanghai 200011, China.
Oxid Med Cell Longev. 2017;2017:6292630. doi: 10.1155/2017/6292630. Epub 2017 Jul 19.
The aging periodontium may be vulnerable to periodontal pathogens and poor response to inflammation and susceptible to tumorigenesis. Human gingival fibroblasts (hGFs) through continuously replicative culture served as an in vitro surrogate for aging. To investigate the effects of the mechanistic target of rapamycin (mTOR) inhibition on the aging gingiva, we stimulated the high-passage hGFs with rapamycin (20 nmol/L) for 3 days and 30 days. The cellular and biological changes were examined by immunofluorescence, real-time PCR, ELISA, Western blotting, and flow cytometry. The data demonstrated that the inhibition of mTOR signaling led to fewer senescence-associated beta-galactosidase- (SA--Gal-) positive cells, delayed the onset of senescence, preserved the capability of proliferation, and lowered the expression levels of relevant senescence-associated markers, such as p16, p21, interleukin-6 (IL-6), and IL-8. In addition, when infected by prominent periodontal pathogens, (ATCC 33277), rapamycin-pretreated groups decreased the expression of inflammatory cytokines ( and ) compared with the control group. mTOR inhibition upregulated the gene expression of antioxidant components (, , and ; < 0.05) and consequently neutralized the excessive reactive oxygen species (ROS). In conclusion, our results indicated that mTOR inhibition might rejuvenate the aging gingiva to some extent and relieve inflammation through eliminating oxidative stress.
衰老的牙周组织可能容易受到牙周病病原体的影响，对炎症的反应能力较差，并且容易发生肿瘤。通过连续复制培养的人牙龈成纤维细胞（hGFs）可作为体外衰老的替代物。为了研究雷帕霉素（mTOR）抑制作用对衰老牙龈的影响，我们用雷帕霉素（20nmol/L）刺激高传代 hGFs 3 天和 30 天。通过免疫荧光、实时 PCR、ELISA、Western blot 和流式细胞术检查细胞和生物学变化。数据表明，抑制 mTOR 信号导致更少的衰老相关β-半乳糖苷酶（SA-β-Gal）阳性细胞，延迟衰老的发生，保持增殖能力，并降低相关衰老相关标志物（如 p16、p21、白细胞介素-6（IL-6）和 IL-8）的表达水平。此外，当被主要牙周病病原体（ATCC 33277）感染时，与对照组相比，雷帕霉素预处理组炎症细胞因子（和）的表达降低。mTOR 抑制作用上调抗氧化成分（、和；<0.05）的基因表达，从而中和过量的活性氧（ROS）。总之，我们的结果表明，mTOR 抑制作用可能在一定程度上使衰老的牙龈恢复活力，并通过消除氧化应激缓解炎症。
