Role of microRNAs in synovial fibroblast biology and functions

背景/理由：滑膜成纤维细胞是存在于滑膜中的主要细胞，通过促进细胞外基质（ECM）的产生，对维持关节稳态至关重要。滑膜成纤维细胞对特定刺激（细胞因子和生长因子）的反应获得肌成纤维细胞型表型，并产生过量的ECM，导致组织纤维化和功能丧失。控制滑膜成纤维细胞功能（分化、迁移、增殖和粘附）和ECM产生的内源性介质在很大程度上是未知的。MicroRNAs （miRNAs）是一种小的非编码rna，可调控60%以上的编码基因，在各种病理生理过程中发挥关键作用。microrna在滑膜成纤维细胞生物学和功能中的确切作用在很大程度上是未知的。******初步研究：我们最近的研究已经确定了一组microrna (miR-23a-3p, 24-3p, 27a-3p, 27b-3p, 29c-3p， 186-5p和378a-5p)，它们在正常人类滑膜中，特别是滑膜成纤维细胞中含量很高，并且它们的表达在炎症刺激IL-1β的反应中显著升高。这些鉴定的mirna在滑膜生物学及其功能中的具体作用尚未报道。我们的初步数据显示，在炎症性IL-1β刺激（而不是TNF-α或IL-6）的反应中，所有这些mirna的表达都显着升高。我们关于miR-27b-3p的试点数据强烈表明，miR-27b-3p被IL-1β激活，并参与成纤维细胞-肌成纤维细胞分化和ECM的产生。我们预计其他已鉴定的mirna也可能在与ECM产生相关的某些滑膜成纤维细胞功能中发挥作用。******假设：mirna可能通过诱导滑膜成纤维细胞向肌成纤维细胞样细胞的分化，以及滑膜成纤维细胞的迁移、增殖和滑膜内的粘附信号传导，在控制ECM的产生中发挥核心作用。******为了研究mirna在ECM产生中的确切作用，本项目的主要目标是：***1。确定鉴定的microrna在滑膜成纤维细胞分化（成纤维细胞-肌成纤维细胞样细胞）、增殖和存活中的作用。* * * 2。确定鉴定的microrna在滑膜成纤维细胞迁移、粘附信号传导、ECM收缩及其产生中的作用。*** 2。确定这些mirna在滑膜成纤维细胞中介导ECM产生的信号通路。******意义：该研究项目将在滑膜成纤维细胞生物学领域取得重大进展，并有助于确定控制滑膜成纤维细胞-肌成纤维细胞分化、迁移、粘附和ECM产生的关键内源性机制。该计划还将提供世界一流的培训，以培养高技能和合格的研究人员。********

Background/Rationale: Synovial fibroblasts are predominant cells present in the synovial membrane and are crucial for the maintenance of joint homeostasis by contributing towards the production of extracellular matrix (ECM). Synovial fibroblasts in response to specific stimuli (cytokines and growth factors) acquire myofibroblast-type phenotype and produce excessive amount of ECM resulting in tissue fibrosis and loss of function. The endogenous mediators that control synovial fibroblast functions (differentiation, migration, proliferation and adhesion) and ECM production are largely unknown. MicroRNAs (miRNAs) are small non-coding RNAs that regulate more than 60% of all coding genes and play pivotal roles in various pathophysiological processes. The exact role of microRNAs in synovial fibroblast biology and functions is largely unknown.******Preliminary Studies: Our recent studied have identified a panel of microRNAs (miR-23a-3p, 24-3p, 27a-3p, 27b-3p, 29c-3p, 186-5p and 378a-5p) that are highly abundant in normal human synovium, especially synovial fibroblasts and their expression is dramatically elevated in response to inflammatory stimuli, IL-1β. The specific roles of these identified miRNAs in synovial biology and its functions has never been reported. Our preliminary data shows that, in response to inflammatory IL-1β stimulation (and not TNF-α or IL-6), all these miRNAs show significant elevation in their expression. Our pilot data on miR-27b-3p strongly suggest that miR-27b-3p is activated by IL-1β and is involved in fibroblast-myofibroblast differentiation and ECM production. We anticipate that other identified miRNAs may also play a role in certain synovial fibroblast functions associated with ECM production.******Hypothesis: miRNAs may play a central role in controlling the ECM production by inducing the differentiation of synovial fibroblast to myofibroblast-like cells as well as in synovial fibroblast migration, proliferation and adhesive signaling in the synovium.******To examine the exact role(s) of miRNAs in ECM production, the major objectives of this program are: ***1. Determine the role of identified microRNAs in synovial fibroblast differentiation (fibroblast-myofibroblast like cells), proliferation and survival. ***2. Determine the role of identified microRNAs in synovial fibroblast migration, adhesive signaling, ECM contraction and its production.***3. Identify the signaling pathways through which these miRNAs operate in synovial fibroblasts to mediate ECM production.******Significance: This research program will enable significant advancement in the field of synovial fibroblast biology and help identify crucial endogenous mechanisms that control synovial fibroblast-myofibroblast differentiation, migration, adhesion and ECM production. This program will also provide world-class training to create highly skilled and qualified research personnel.********