Division of Aging and Geriatric Dentistry, Tohoku University Graduate School of Dentistry, Sendai, Japan.
Division of Craniofacial Development and Tissue Biology, Tohoku University Graduate School of Dentistry, Sendai, Japan.
J Periodontal Res. 2022 Aug;57(4):733-741. doi: 10.1111/jre.12996. Epub 2022 May 3.
The present study was designed to investigate the whole transcriptome of periodontal tissues of both young and aged mice to identify the characteristic up-regulation of protease genes with aging and to localize their translated protein products in the periodontal tissues.
The metzincin protease superfamily is composed of matrix metalloproteinases (MMPs), a disintegrin and metalloproteinases, and a disintegrin and metalloproteinases with thrombospondin motifs. Up-regulation of these extracellular matrix-degrading proteases has been implicated in senescence of tissues and organs, including the skin. However, few studies have investigated the expression profiles of these proteases and potential involvement in aging of periodontal tissues.
Periodontal tissues with the surrounding mandibular bones were collected from 50- and 10-week-old mice. Total RNA was extracted from the periodontal tissue and analyzed by cap analysis of gene expression (CAGE) to identify differentially expressed genes encoding the metzincin proteases. Furthermore, quantitative real-time polymerase chain reaction (qRT-PCR) was performed to validate the CAGE results, and the phenotypic expression of proteases involved in aging was localized via immunohistochemical analysis.
The CAGE results showed that the expression levels of MMP-3, -10, and -12 were up-regulated at 50 weeks. Subsequent qRT-PCR analysis showed that the gene expression levels of MMP-3 and -10 were significantly increased with age. MMP-10 immunoreactivity was localized exclusively in the cementum and alveolar bone adjacent to the periodontal ligament and was stronger and broader in aged mice than young mice. MMP-3 immunoreactivity was localized in the periodontal ligaments at both 10 and 50 weeks.
In the present study, we demonstrated that the expression of MMP-3 and -10 increased with aging and identified their characteristic localizations in aged periodontal tissues.
本研究旨在对年轻和老年小鼠牙周组织的全转录组进行研究，以鉴定与衰老相关的蛋白酶基因的特征性上调，并定位其在牙周组织中的翻译蛋白产物。
金属蛋白酶超家族由基质金属蛋白酶（MMPs）、解整合素和金属蛋白酶以及含血栓反应蛋白基序的解整合素和金属蛋白酶组成。这些细胞外基质降解蛋白酶的上调已被认为与组织和器官的衰老有关，包括皮肤。然而，很少有研究调查这些蛋白酶的表达谱及其在牙周组织衰老中的潜在作用。
从 50 周龄和 10 周龄小鼠的牙周组织及其周围下颌骨中收集牙周组织。从牙周组织中提取总 RNA，并用帽分析基因表达（CAGE）分析以鉴定编码金属蛋白酶的差异表达基因。此外，进行实时定量聚合酶链反应（qRT-PCR）以验证 CAGE 结果，并通过免疫组织化学分析定位参与衰老的蛋白酶的表型表达。
CAGE 结果显示，MMP-3、-10 和 -12 的表达水平在 50 周时上调。随后的 qRT-PCR 分析显示，MMP-3 和 -10 的基因表达水平随年龄显著增加。MMP-10 免疫反应性仅定位于牙骨质和牙周韧带相邻的牙槽骨中，在老年小鼠中比年轻小鼠更强且更广泛。MMP-3 免疫反应性在 10 周和 50 周时均定位于牙周韧带。
在本研究中，我们证明了 MMP-3 和 -10 的表达随年龄增长而增加，并确定了它们在老年牙周组织中的特征性定位。
