中国组织工程研究 ›› 2023, Vol. 27 ›› Issue (33): 5283-5291.doi: 10.12307/2023.713

• 牙髓及牙周膜干细胞 Dental pulp and periodontal ligament stem cells • 上一篇    下一篇

RNA结合蛋白Lin28A差异表达可调控牙周膜干细胞的成骨分化

何  琴1,2,3,卜  艳1,2,林光磊1,2,罗  晶1,2,雍  敏1,3,黄永清1,4   

  1. 1宁夏医科大学口腔医学院正畸学系,宁夏回族自治区银川市   750004;2宁夏回族自治区干细胞与再生医学重点实验室,宁夏回族自治区银川市   750004;3宁夏医科大学总医院口腔正畸科,宁夏回族自治区银川市   750004;4宁夏医科大学口腔医学院口腔颌面外科学系,宁夏回族自治区银川市   750004
  • 收稿日期:2022-10-08 接受日期:2022-11-18 出版日期:2023-11-28 发布日期:2023-03-30
  • 通讯作者: 何琴,博士,副教授,副主任医师,宁夏医科大学口腔医学院正畸学系,宁夏回族自治区银川市 750004;宁夏回族自治区干细胞与再生医学重点实验室,宁夏回族自治区银川市 750004;宁夏医科大学总医院口腔正畸科,宁夏回族自治区银川市 750004
  • 作者简介:何琴,女,1981年生,新疆维吾尔自治区阿克苏市人,汉族,2018年山东大学毕业,博士,副教授,副主任医师,主要从事口腔基础医学和口腔正畸学的教研工作,主攻口腔干细胞的再生和相关分子机制研究。
  • 基金资助:
    宁夏自然科学基金(2019AAC03078),项目负责人:何琴;宁夏医科大学校级特殊人才项目(XT2018019),项目负责人:何琴;宁夏医科大学2020年校级学术技术带头人后备培育对象项目(20012602201),项目负责人:何琴

Differential expression of RNA binding protein Lin28A regulates osteoblastic differentiation of periodontal ligament stem cells

He Qin1, 2, 3, Bu Yan1, 2, Lin Guanglei1, 2, Luo Jing1, 2, Yong Min1, 3, Huang Yongqing1, 4   

  1. 1Department of Orthodontics, School of Stomatology, Ningxia Medical University, Yinchuan 750004, Ningxia Hui Autonomous Region, China; 2Key Laboratory of Stem Cell and Regenerative Medicine of Ningxia Hui Autonomous Region, Yinchuan 750004, Ningxia Hui Autonomous Region, China; 3Department of Orthodontics, General Hospital of Ningxia Medical University, Yinchuan 750004, Ningxia Hui Autonomous Region, China; 4Department of Oral and Maxillofacial Surgery, School of Stomatology, Ningxia Medical University, Yinchuan 750004, Ningxia Hui Autonomous Region, China
  • Received:2022-10-08 Accepted:2022-11-18 Online:2023-11-28 Published:2023-03-30
  • Contact: He Qin, MD, Associate professor, Associate chief physician, Department of Orthodontics, School of Stomatology, Ningxia Medical University, Yinchuan 750004, Ningxia Hui Autonomous Region, China; Key Laboratory of Stem Cell and Regenerative Medicine of Ningxia Hui Autonomous Region, Yinchuan 750004, Ningxia Hui Autonomous Region, China; Department of Orthodontics, General Hospital of Ningxia Medical University, Yinchuan 750004, Ningxia Hui Autonomous Region, China
  • About author:He Qin, MD, Associate professor, Associate chief physician, Department of Orthodontics, School of Stomatology, Ningxia Medical University, Yinchuan 750004, Ningxia Hui Autonomous Region, China; Key Laboratory of Stem Cell and Regenerative Medicine of Ningxia Hui Autonomous Region, Yinchuan 750004, Ningxia Hui Autonomous Region, China; Department of Orthodontics, General Hospital of Ningxia Medical University, Yinchuan 750004, Ningxia Hui Autonomous Region, China
  • Supported by:
    Natural Science Foundation of Ningxia Hui Autonomous Region, No. 2019AAC03078 (to HQ); School Level Special Talents Project of Ningxia Medical University, No. XT2018019 (to HQ); the Backup Training Object Project for Academic and Technical Leaders at the School Level of Ningxia Medical University in 2020, No. 20012602201 (to HQ)

摘要:


文题释义:

牙周膜干细胞:是牙周膜来源的间充质干细胞群体,具有多向分化、自我更新及迁移等能力,从而实现牙周骨组织修复。其中,牙周膜干细胞成骨分化是骨组织修复和再生的生物学基础,揭示其具体的调控功能,可引导干细胞发挥其潜能,有利于牙周组织的维持和生物再生。
Lin28A:是一种高度保守的RNA结合蛋白,首次从秀丽隐杆线虫中发现,被认为是调控机体发育特征、细胞代谢和维持干细胞处于胚胎状态的重要重编程因子。过去的研究显示,该蛋白可通过与靶标RNA直接作用和间接作用,实现调控细胞的生长和分化;Lin28A的表达差异能调节胚胎干细胞的发育时间和自我更新能力,是细胞活动的主要调节因子。

背景:Lin28A能影响细胞活动的多个方面,包括胚胎干细胞的自我更新、体细胞的重编程、个体的生长发育、组织代谢及致癌作用等,而它对牙周膜干细胞成骨分化的影响国内外均没有深入研究,其影响机制更未见报道。
目的:探索Lin28A对牙周膜干细胞成骨分化能力的影响。
方法:经典酶消化法分离、培养人牙周膜干细胞,qRT-PCR检测 Lin28A 在该类细胞中的分布情况及其在成骨诱导不同时间的差异性表达;构建Lin28A过表达及干扰表达的慢病毒载体转染至牙周膜干细胞,荧光显微镜观察转染效果;qRT-PCR验证慢病毒转染后Lin28A的表达差异,并进一步从正反两个方面检测成骨诱导培养过程中成骨基因碱性磷酸酶、Runt相关转录因子2和骨桥蛋白的表达量以及碱性磷酸酶染色和茜素红染色,Western blot检测Runt相关转录因子2的蛋白表达水平;应用生物信息学技术预测和双荧光素酶结合实验验证与Lin28A有关的let-7家族成员之间的相关关系,并通过成骨诱导培养差异表达Lin28A的牙周膜干细胞,测定细胞成骨分化过程中表达变化最明显的miRNA。

结果与结论:①Lin28A 富集在牙周膜干细胞的细胞核中,且在成骨诱导不同时间后呈表达上升的趋势;②与空白对照组比较,在过表达Lin28A的牙周膜干细胞模型中,碱性磷酸酶染色和茜素红染色相较空白对照组明显深染,成骨基因碱性磷酸酶、Runt相关转录因子2及骨桥蛋白的表达量分别增加3.3倍、5.1倍及2.2倍(P < 0.01);干扰Lin28A表达的细胞模型中,碱性磷酸酶染色和茜素红染色相较对照组染色减少,成骨基因碱性磷酸酶、Runt相关转录因子2及骨桥蛋白的表达量分别下降19%,61%及10%(P < 0.01);③成骨相关转录因子Runt相关转录因子2的蛋白表达水平与mRNA的差异趋势一致,过表达组呈上升趋势,干扰组呈下降趋势;④生物信息学预测出与Lin28A相关的let-7家族成员有8个,分别为let-7a、let-7b、let-7c、let-7d、let-7e、let-7f、let-7g和let-7i,经正常培养和成骨诱导培养筛选发现let-7a和let-7c随Lin28A的表达差异而发生明显的变化,以let-7a的表达趋势最显著;双荧光素酶结合实验也证实let-7a与Lin28A的3’-UTR直接结合,参与影响牙周膜干细胞的成骨分化过程;⑤结果提示:Lin28A参与调控牙周膜干细胞成骨分化,呈正性相关,即过表达Lin28A使牙周膜干细胞成骨能力增强,干扰Lin28A表达后牙周膜干细胞成骨能力减弱;牙周膜干细胞成骨分化受到Lin28A的调控影响。

https://orcid.org/0000-0003-0082-650X (何琴) 

中国组织工程研究杂志出版内容重点:干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程

关键词: 牙周膜干细胞, 成骨分化, Lin28A, 慢病毒载体, 转染, 基因干扰, let-7a

Abstract:

BACKGROUND: The cellular activity of Lin28A can be influenced in several ways, including the self-renewal of embryonic stem cells, somatic cell reprogramming, individual growth and development, tissue metabolism, and carcinogenic consequences. However, neither domestically nor internationally have its effects on periodontal ligament stem cell ability to differentiate into osteoblasts been well explored; the underlying mechanisms are not known.

OBJECTIVE: To investigate the impact of Lin28A on periodontal ligament stem cell capacity for osteogenic differentiation.

METHODS: By using conventional enzyme digestion, periodontal ligament stem cells were extracted and cultured. The distribution of Lin28A in these cells and the differential expression of Lin28A at different time points of osteogenic induction were detected by qRT-PCR. Lentiviral vectors with Lin28A overexpression and interference expression were constructed and transfected into periodontal ligament stem cells. Fluorescence microscopy was used to observe the transfection effect. qRT-PCR was used to verify the expression difference of Lin28A after lentivirus transfection. The expression levels of osteoblastic genes alkaline phosphatase, Runt-related transcription factor 2 and osteopontin, alkaline phosphatase staining and alizarin red staining results were further detected from positive and negative aspects. The protein expression level of Runt-related transcription factor 2 was detected by western blot assay. Bioinformatics techniques and dual luciferase were used to predict and verify the relationship between Lin28A-related let-7 family members. The periodontal ligament stem cells differentially expressing Lin28A were cultured through osteoblastic induction, and the miRNA with the most obvious expression change during osteoblastic differentiation was determined. 
RESULTS AND CONCLUSION: (1) Lin28A was enriched in the nucleus of periodontal ligament stem cells, and the expression of Lin28A increased at different time points after osteogenic induction. (2) In the periodontal ligament stem cell models with Lin28A overexpression, alkaline phosphatase staining and alizarin red staining were significantly deeper than those in the blank control group; the expression levels of alkaline phosphatase, Runt-related transcription factor 2 and osteopontin were increased 3.3, 5.1 and 2.2 times, respectively, compared with the blank ones (P < 0.01). In cell models that interfered with Lin28A expression, alkaline phosphatase staining and alizarin red staining were also decreased compared with the control group. The levels of alkaline phosphatase, Runt-related transcription factor 2 and osteopontin decreased 0.19-fold, 0.61-fold and 0.1-fold, respectively (P < 0.01). (3) The protein level of Runt-related transcription factor 2 was consistent with the mRNA difference tendency. The expression of Runt-related transcription factor 2 was increased in the overexpression group and decreased in the interference group. (4) Bioinformatics predicted that Lin28A was associated with eight let-7 family members, which were let-7a, let-7b, let-7c, let-7d, let-7e, let-7f, let-7g and let-7i, respectively. After screening, the expression levels of let-7a and let-7c showed significant changes with Lin28A expression, and let-7a showed the most significant trend. Double luciferase binding assay confirmed that let-7a was directly bound to the 3'-UTR of Lin28A and was involved in the osteogenic differentiation of periodontal ligament stem cells. (5) The results suggested that Lin28A was involved in the regulation of osteogenic differentiation of periodontal ligament stem cells, with a positive correlation. That was, overexpression of Lin28A promoted the osteogenic ability of periodontal ligament stem cells, and the osteogenic ability of periodontal ligament stem cells was weakened after interference of Lin28A expression. The osteogenic differentiation of periodontal ligament stem cells was regulated by Lin28A .

Key words: periodontal ligament stem cell, osteogenic differentiation, Lin28A, lentiviral vector, transfection, genetic interference, let-7a

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