Department of Medicine, Division of Endocrinology, Mayo Clinic College of Medicine, Rochester, MN.
Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN.
J Periodontol. 2021 Oct;92(10):1483-1495. doi: 10.1002/JPER.20-0529. Epub 2021 Jan 6.
BACKGROUND: Coinciding with other chronic comorbidities, the prevalence of periodontal disease increases with aging. Mounting evidence has established that senescent cells accumulate at sites of age-related pathologies, where they promote "non-microbial" inflammation. We hypothesized that alveolar bone osteocytes develop senescence characteristics in old age. METHODS: Alveolar bone samples were obtained from young (6 months) and old (20 to 22 months) mice to evaluate the expression of senescence biomarkers by immunofluorescent staining. Osteocyte-enriched fractions were used to characterize the age-related senescence-associated secretory phenotype (SASP) gene expression profile. Primary alveolar bone cells were exposed to the SASP via in vitro senescent conditioned media (SCM) administration. A multiplex assay confirmed protein levels of specific cytokines. Interactions with bacterial components were evaluated by stimulating cells with lipopolysaccharide (LPS). RESULTS: Increased senescence-associated distension of satellites (SADS) and p16 mRNA expression were identified in alveolar bone osteocytes with aging. These findings were associated with increased levels of DNA damage, and activated p38 MAPK, both inducers of senescence. Furthermore, interleukin-6 (IL6), IL17, IGFBP4, and MMP13 were significantly upregulated with aging in osteocyte-enriched samples. Interestingly, SCM potentiated the LPS-induced expression of IL1α, IL1β, and IL6. Cell migration and differentiation were also impeded by SCM. These in vitro effects were ameliorated by the p38 MAPK inhibitor SB202190. CONCLUSIONS: Accumulation of senescent osteocytes contributes to deterioration of the periodontal environment by exacerbating chronic inflammation and reducing regeneration in old age. Cellular senescence is a cell-intrinsic response to DNA damage, and a host-related mechanism associated with aging that could potentiate inflammation induced by bacterial components.
背景:随着年龄的增长,牙周病与其他慢性合并症一起增加。越来越多的证据表明,衰老细胞在与年龄相关的病变部位积累,在这些部位促进“非微生物”炎症。我们假设牙槽骨成骨细胞在老年时会出现衰老特征。
方法:从年轻(6 个月)和老年(20 至 22 个月)小鼠中获取牙槽骨样本,通过免疫荧光染色评估衰老生物标志物的表达。使用富含成骨细胞的级分来表征与年龄相关的衰老相关分泌表型(SASP)基因表达谱。通过体外衰老条件培养基(SCM)给药将 SASP 暴露于原代牙槽骨细胞。多重分析证实了特定细胞因子的蛋白水平。通过用脂多糖(LPS)刺激细胞来评估与细菌成分的相互作用。
结果:随着年龄的增长,在牙槽骨成骨细胞中观察到卫星细胞衰老相关肿胀(SADS)和 p16 mRNA 表达增加。这些发现与衰老相关的 DNA 损伤水平增加以及衰老的诱导剂 p38 MAPK 激活有关。此外,在富含成骨细胞的样本中,IL6、IL17、IGFBP4 和 MMP13 的水平随着年龄的增长而显著上调。有趣的是,SCM 增强了 LPS 诱导的 IL1α、IL1β 和 IL6 的表达。SCM 还阻碍了细胞迁移和分化。这些体外作用通过 p38 MAPK 抑制剂 SB202190 得到改善。
结论:衰老成骨细胞的积累通过加剧慢性炎症和减少老年时的再生,导致牙周环境恶化。细胞衰老作为一种细胞内固有反应,与衰老相关的与宿主相关的机制可能会增强细菌成分诱导的炎症。
J Bone Miner Res. 2016-11
Curr Osteoporos Rep. 2020-10
Bone. 2019-1-16
Pharmaceuticals (Basel). 2025-4-23
J Clin Invest. 2024-6-17
Front Pharmacol. 2024-9-26
J Dent Res. 2024-7
Nat Commun. 2018-12-21
J Bone Miner Res. 2018-10-15
Stem Cell Res Ther. 2017-11-16
Periodontol 2000. 2017-10
J Vis Exp. 2017-5-1
Curr Osteoporos Rep. 2016-12