Objective: To investigate the effects of long non-coding RNA (lncRNA) LINC01133 on the cementogenic differentiation of human periodontal ligament stem cells (hPDLSC) and the underlying mechanism. Methods: A total of 12 teeth were harvested from 10 patients aged 17-30 years in the Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University for impacted or orthodontic reasons from September 2021 to January 2022. The hPDLSCs were isolated from the teeth and transfected with small interfering RNA-LINC01133 (si-LINC01133) or small interfering RNA-negative control (si-NC). The si-LINC01133 was regarded as the experimental group, and the si-NC was regarded as the control one. The silencing efficiency of LINC01133 in the hPDLSCs was evaluated by real-time quantitative PCR (RT-qPCR). Western blotting was used to detect the protein expression levels of cementogenic differentiation-related factors including bone sialoprotein (BSP), cementum attachment protein (CAP), and cementum protein-1 (CEMP-1). Mitochondrial reactive oxygen species (mtROS) production was assessed using the MitoSox by flow cytometry. Mitochondrial membrane potential (MMP) was detected by JC-1 fluorescence staining. Mitochondrial respiratory chain complexes proteins including NADH dehydrogenase [ubiquinone] 1 beta subcomplex subunit 8 (NDUFB8), succinate dehydrogenase complex flavoprotein subunit A (SDHA), ubiquinol-cytochrome c reductase core protein 1 (UQCR1), cytochrome c oxidase subunit 4 isoform 1 (COXⅣ), and ATP synthase F1 subunit alpha (ATP5A) were evaluated by Western blotting. Results: The expression levels of LINC01133 could be suppressed by more than 60% with si-LINC01133 (control group: 1.000±0.000, experimental group: 0.385±0.128) (t=10.72, P<0.01). Suppression of LINC01133 in hPDLSCs decreased the levels of cementogenic differentiation-related proteins including BSP (control group: 1.000±0.000, experimental group: 0.664±0.179) (t=4.62, P<0.01) and CAP (control group: 1.000±0.000, experimental group: 0.736±0.229) (t=2.83, P<0.05). Suppression of LINC01133 in hPDLSCs increased the production of mtROS (control group: 1.000±0.000, experimental group: 1.458±0.185) (t=4.96, P<0.05) and the expression of NDUFB8 (control group: 1.000±0.000, experimental group: 1.683±0.397) (t=3.45, P<0.05), as well as decreased MMP levels (control group: 1.000±0.000, experimental group: 0.209±0.029) (t=53.99, P<0.01) and the expression of SDHA (control group: 1.000±0.000, experimental group: 0.428±0.228) (t=5.02, P<0.05). No significant changes in the UQCR1, COXⅣ, and ATP5A expression levels were found between the control group and exprimental group (P>0.05). Conclusions: LINC01133 regulates the cementogenic differentiation of hPDLSCs possibly via modulating the mitochondrial functions.
目的： 探索长链非编码RNA（long non-coding RNA，lncRNA）LINC01133对人牙周膜干细胞（human periodontal ligament stem cells，hPDLSC）成牙骨质分化潜能的影响及其作用机制。 方法： 收集2021年9月至2022年1月第四军医大学口腔医学院口腔颌面外科17~30岁10例就诊患者因正畸需要或因阻生拔除的牙齿共12颗，从离体牙上提取hPDLSC，分别转染靶向LINC01133小干扰RNA（small interfering RNA-LINC01133，si-LINC01133）或阴性对照小干扰RNA（small interfering RNA-negative control，si-NC），以转染si-LINC01133为实验组，转染si-NC为阴性对照组。利用实时荧光定量PCR（real-time quantitative PCR，RT-qPCR）检测si-LINC01133的沉默效率；通过蛋白质印迹法检测hPDLSC成牙骨质分化相关蛋白包括骨涎蛋白（bone sialoprotein，BSP）、牙骨质附着蛋白（cementum attachment protein，CAP）、牙骨质蛋白1（cementum protein-1，CEMP-1）的表达；利用流式细胞术和线粒体超氧化物指示剂MitoSOX检测细胞线粒体活性氧产量；通过JC-1荧光染色法检测线粒体膜电位水平；利用蛋白质印迹法检测线粒体呼吸链复合体蛋白包括NADH脱氢酶［泛醌］1β亚单位8（NADH dehydrogenase［ubiquinone］1 beta subcomplex subunit 8，NDUFB8）、琥珀酸脱氢酶亚单位A（succinate dehydrogenase complex flavoprotein subunit A，SDHA）、泛醌-细胞色素c还原酶核心蛋白1（ubiquinol-cytochrome c reductase core protein 1，UQCR1）、细胞色素c氧化酶亚单位4亚型1（cytochrome c oxidase subunit 4 isoform 1，COXⅣ）、ATP合成酶F1亚单位α（ATP synthase F1 subunit alpha，ATP5A）的表达水平。 结果： hPDLSC的LINC01133表达水平被si-LINC01133有效沉默（阴性对照组：1.000±0.000，实验组：0.385±0.128）（t=10.72，P<0.01），沉默效率超过60%。LINC01133沉默后，hPDLSC BSP表达水平显著下降（阴性对照组：1.000±0.000，实验组：0.664±0.179）（t=4.62，P<0.01）；CAP表达水平显著下降（阴性对照组：1.000±0.000，实验组：0.736±0.229）（t=2.83，P<0.05）。LINC01133沉默后，hPDLSC线粒体活性氧产量显著上升（阴性对照组：1.000±0.000，实验组：1.458±0.185）（t=4.96，P<0.05）；线粒体膜电位水平显著下降（阴性对照组：1.000±0.000，实验组：0.209±0.029）（t=53.99，P<0.01）；NDUFB8表达水平显著上升（阴性对照组：1.000±0.000，实验组：1.683±0.397）（t=3.45，P<0.05）；SDHA表达水平显著下降（阴性对照组：1.000±0.000，实验组：0.428±0.228）（t=5.02，P<0.05）。实验组UQCR1、COXⅣ和ATP5A的表达水平与阴性对照组相比差异均无统计学意义（P>0.05）。 结论： LINC01133可能通过调控hPDLSC线粒体功能，进而影响hPDLSC成牙骨质分化潜能。.