Su Chengli, Wang Hongning, Xu Luchen, Zhang Yue, Li Yunfeng
State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
Department of Orthodontics, Yantai Stomatological Hospital, Yantai, Shangdong Province, China.
Arch Med Sci. 2021 Mar 21;18(6):1638-1649. doi: 10.5114/aoms/105838. eCollection 2022.
Growing evidence supports the involvement of long noncoding RNAs (lncRNAs) in bone metabolism and diseases. This study aims to investigate the involvement of the lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in the pathological process of osteoporosis and the effects of MALAT1 on regulation of BMSC differentiation through competitive endogenous RNA (ceRNA) mechanisms.
The expression of MALAT1 and miR-320a was determined using RT-PCR in bone tissue derived from female SD (Sprague Dawley) rats with osteoporosis. Immunohistochemical (IHC) staining was used to evaluate the expression of neuropilin-1 (NRP-1) and β-catenin. Bone marrow mesenchymal stem cells (BMSCs) were divided into 4 groups: control, NC (negative control), MALAT1 siRNA, and miR-320a mimics. Forty-eight hours later, the effect of MALAT1 on the miR-320a expression, proliferation and osteogenic differentiation of BMSCs was investigated. Two weeks later, the cell activity, alkaline phosphatase (ALP) activity, and mRNA expression of Osterix and Runx2 were evaluated. Three weeks later, alizarin red staining of calcified nodules and Western blot analysis of the expression of β-catenin, NRP-1, osteocalcin (OCN), and osteopontin (OPN) were performed.
Downregulated MALAT1or upregulated miR-320a expression inhibited the activity and osteogenic differentiation of BMSCs, resulting in low ALP activity and NRP-1 expression, fewer calcified nodules, decreased mRNA levels of Osterix and Runx2, and inhibited expression of NRP-1, OCN, and OPN. MALAT1 silencing did not decrease the protein level of β-catenin in the cytoplasm but suppressed that in the nucleus.
Downregulated MALAT1 and upregulated miR-320a expression play an important role in the pathological process of osteoporosis, via inhibition of the osteogenic differentiation of BMSCs.
越来越多的证据支持长链非编码RNA（lncRNAs）参与骨代谢和疾病。本研究旨在探讨长链非编码RNA转移相关肺腺癌转录本1（MALAT1）在骨质疏松症病理过程中的作用，以及MALAT1通过竞争性内源RNA（ceRNA）机制对骨髓间充质干细胞（BMSC）分化调控的影响。
采用逆转录聚合酶链反应（RT-PCR）检测骨质疏松雌性SD（Sprague Dawley）大鼠骨组织中MALAT1和miR-320a的表达。免疫组织化学（IHC）染色用于评估神经纤毛蛋白-1（NRP-1）和β-连环蛋白的表达。将骨髓间充质干细胞（BMSCs）分为4组：对照组、阴性对照组（NC）、MALAT1小干扰RNA（siRNA）组和miR-320a模拟物组。48小时后，研究MALAT1对BMSCs中miR-320a表达、增殖和成骨分化的影响。两周后，评估细胞活性、碱性磷酸酶（ALP）活性以及Osterix和Runx2的mRNA表达。三周后，进行钙化结节的茜素红染色以及β-连环蛋白、NRP-1、骨钙素（OCN）和骨桥蛋白（OPN）表达的蛋白质印迹分析。
MALAT1表达下调或miR-320a表达上调均抑制BMSCs的活性和成骨分化，导致ALP活性和NRP-1表达降低、钙化结节减少、Osterix和Runx2的mRNA水平下降，并抑制NRP-1、OCN和OPN的表达。MALAT1沉默并未降低细胞质中β-连环蛋白的蛋白水平，但抑制了细胞核中的β-连环蛋白水平。
MALAT1表达下调和miR-320a表达上调通过抑制BMSCs的成骨分化在骨质疏松症的病理过程中起重要作用。
