RGS2基因反义链转录LncRNA调控骨髓间充质干细胞分化及其在增龄性骨丢失中的作用研究

We have identified that the expression of the RGS2-antisence transcript lncRNA (RGS2-AS) in bone marrow mesenchymal stem cells (BMSCs) from aged mice was significantly upregulated than those from young mice, indicating the important role of LncRNA RGS2-AS on age-related bone loss. This paper intends to resolve its meaning and essence. First, mouse BMSCs will be induced to differentiate into adipocytes or osteoblasts, then we will observe its effect on BMSCs differentiation using gene transfection strategies for LncRNA RGS2-AS in this process; and we will analyze the effects of RGS2-AS on RGS2 mRNA stability and protein expression level by RNase protection assay. We will construct mice models specifically overexpress LncRNA RGS2-AS in BMSCs, and observe BMSCs differentiation, fat accumulation of bone marrow cavity and bone formation parameters. Furthermore, we will study the treatment of age-related bone loss by blocking LncRNA RGS2-AS using LncRNA ShRNA through marrow cavity injection in aged mice. This study will help to clarify the mechanism of BMSCs differentiation in the aging process, providing a new way for the prevention and treatment of senile osteoporosis.

我们前期研究发现老年小鼠骨髓间充质干细胞（BMSCs）促脂肪细胞分化基因RGS2反义链转录的LncRNA RGS2-AS表达明显上调，提示LncRNA RGS2-AS在衰老时BMSCs分化与增龄性骨丢失中起着重要作用。本课题拟解析其意义及本质。首先诱导小鼠BMSCs向脂肪细胞或成骨细胞分化，在此过程中运用基因转染策略调控LncRNA RGS2-AS，观察其对BMSCs分化的影响；并通过RNA保护酶法等分析RGS2-AS对RGS2 mRNA稳定性与蛋白质表达的作用。构建BMSCs特异性LncRNA RGS2-AS过表达小鼠，观察其表达增加对BMSCs分化、骨髓腔脂肪累积与骨形成的影响。进而骨髓腔注射LncRNA ShRNA至老年小鼠，观察阻断LncRNA RGS2-AS表达对增龄性骨丢失的治疗作用。本研究有助于阐明衰老BMSCs分化进程改变机理，为老年性骨质疏松防治提供新思路。

在研究中，我们发现了一个新的LncRNA Bmcob，可调节小鼠原代骨髓间充质干细胞（BMSCs）的成骨分化。Bmcob在BMSCs成骨分化早中期表达明显上升，而抑制Bmcob表达则抑制了BMSCs的成骨分化，过表达则可减少成骨分化过程中的氧化应激水平。随后我们发现硒蛋白P（Sepp1）位于Bmcob基因附近，与其调节功能相关。此外，Bmcob敲减时BMSCs中有一系列硒蛋白表达下降。进一步研究发现，Bmcob与SBP2有关，这是一个关键的硒蛋白合成相关的反式作用因子。最后，我们提出一个猜想，通过调节SBP2的核质交流，Bmcob调节了一系列硒蛋白表达，包括sepp1，然后调节BMSCs的成骨分化。我们的研究提出了BMSCs成骨分化的新机制，并为骨质疏松症的治疗提供了新的蛋白靶点。