BRD4 promotes heterotopic ossification through upregulation of LncRNA MANCR.
BRD4 promotes heterotopic ossification through upregulation of LncRNA MANCR.
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BRD4 通过上调 LncRNA MANCR 促进异位骨化。
DOI：
10.1302/2046-3758.1010.bjr-2020-0454.r1
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发表时间：
2021-10
影响因子：
4.6
通讯作者：
Liu H
中科院分区：
文献类型：
--
作者：
Liu L;Li Z;Chen S;Cui H;Li X;Dai G;Zhong F;Hao W;Zhang K;Liu H
获得性异位骨化（HO）是一种以损伤后软组织内骨外异常形成为特征的衰弱性疾病。HO的确切发病机制尚不清楚。据报道，BRD 4可能有助于成骨细胞分化。目前的研究旨在确定BRD 4在HO发病机制中的作用，以及它是否可以成为HO治疗的潜在靶点。对10周龄雄性C57 BL/6 J小鼠进行跟腱穿刺（ATP）小鼠模型。ATP程序后一周，给予小鼠不同的治疗（例如JQ 1、shMancr）。治疗后5周收集跟腱样本进行RNA-seq和实时定量聚合酶链反应（RT-qPCR）分析;腿被移除进行显微CT成像和随后的组织学检查。采用密度梯度离心法分离纯化人骨髓间充质干细胞（hBMSCs）。在一系列干预如敲低或过表达BRD 4后，对hBMSCs进行茜素红染色、RT-qPCR和Western Blot（Runx 2、碱性磷酸酶（ALP）、Osx）。BRD 4的过表达促进hBMSCs的成骨分化，而抑制BRD 4的表达则抑制hBMSCs的成骨分化。Brd 4的过表达增加了有丝分裂相关的长非编码RNA（Mancr）的表达。下调Mancr可抑制BRD 4的骨诱导作用。在体内，JQ 1对BRD 4的抑制显著减弱了ATP模型中的病理性骨形成（p = 0.001）。 发现BRD 4在HO中上调，并且Brd 4-Mancr-Runx 2信号传导参与HO中新骨形成的调节。引用这篇文章：骨关节研究2021;10（10）：668-676。
Acquired heterotopic ossification (HO) is a debilitating disease characterized by abnormal extraskeletal bone formation within soft-tissues after injury. The exact pathogenesis of HO remains unknown. It was reported that BRD4 may contribute to osteoblastic differentiation. The current study aims to determine the role of BRD4 in the pathogenesis of HO and whether it could be a potential target for HO therapy. Achilles tendon puncture (ATP) mouse model was performed on ten-week-old male C57BL/6J mice. One week after ATP procedure, the mice were given different treatments (e.g. JQ1, shMancr). Achilles tendon samples were collected five weeks after treatment for RNA-seq and real-time quantitative polymerase chain reaction (RT-qPCR) analysis; the legs were removed for micro-CT imaging and subsequent histology. Human bone marrow mesenchymal stem cells (hBMSCs) were isolated and purified bone marrow collected during surgeries by using density gradient centrifugation. After a series of interventions such as knockdown or overexpressing BRD4, Alizarin red staining, RT-qPCR, and Western Blot (Runx2, alkaline phosphatase (ALP), Osx) were performed on hBMSCs. Overexpression of BRD4 enhanced while inhibition of Brd4 suppressed the osteogenic differentiation of hBMSCs in vitro. Overexpression of Brd4 increased the expression of mitotically associated long non-coding RNA (Mancr). Downregulation of Mancr suppressed the osteoinductive effect of BRD4. In vivo, inhibition of BRD4 by JQ1 significantly attenuated pathological bone formation in the ATP model (p = 0.001). BRD4 was found to be upregulated in HO and Brd4-Mancr-Runx2 signalling was involved in the modulation of new bone formation in HO. Cite this article: Bone Joint Res 2021;10(10):668–676.