TUG1靶向Sirt1抗炎和促BMSC成骨分化在老年骨质疏松中的作用和机制研究

Inflamm-Aging is the important risk factor of senile osteoporosis.The inhibition of BMSC osteogenic differentiation in “Inflamm-Aging” is the key problem for the prevention, treatment and study of senile osteoporosis, the role of LncRNA in this aspect is rarely reported. Combined with our previous result, we made chip assay and some experiments, and found TUG1 could regulate BMSC osteogenetic differentiation in “Inflamm-Aging”. Over-expression of TUG1 can promote BMSC osteogenic differentiation and anti-inflammation, but the action mechanism has not yet been clarified. Reports and bioinformatics prediction indicated TUG1 could act as miRNA sponge of highest binding capacity with miR-138, and then miR-138 could target Sirt1. Sirt1could regulate the senescence, inflammation, proliferation and osteogenic differentiation of BMSC. Our pretest results indicated TUG1 could combine with miR-138 and regulate Sirt1 level. Therefore, we hypothesized that TUG1 could act as competing endogenous RNA, with decoy activity for miR-138, and by sequestering miR-138, increased the level of the miR-138 target, Sirt1, and regulate the senescence, inflammation, proliferation and osteogenic differentiation of BMSC. We will verify our hypothesis, and provide new target and evidence for preventing and treating senile osteoporosis.

“炎性衰老”是老年骨质疏松发生的重要危险因素，炎性衰老下BMSC成骨分化抑制是目前研究的热点及难点，而LncRNA在这方面的作用报道不多。根据前期研究结果进行高通量测序和预实验，我们发现TUG1参与炎性衰老下BMSC的成骨分化，BMSC中过表达TUG1可抗炎并促进成骨分化，但其机制不明确。文献和生物信息学预测发现，TUG1能够与Sirt1竞争性结合miR-138，参与调控老年BMSC的炎症、衰老、增殖和成骨分化。预实验发现，TUG1能够与miR-138结合，并能调控Sirt1的水平。因此，我们提出假设：TUG1可能通过miR-138/Sirt1信号参与老年BMSC衰老、炎症、增殖和成骨分化的调控，并在老年骨质疏松发生中有一定作用。因此我们拟利用结合位点突变、荧光素酶报告基因、RIP、RNA pull down、特异性基因敲除鼠等方法，证明该假设，为预防和治疗老年骨质疏松提供新线索。

“炎性衰老”是老年骨质疏松发生的重要危险因素，炎性衰老下BMSC成骨分化抑制是目前研究的热点及难点，但是LncRNA在这方面的作用尚不清楚。根据前期研究结果进行高通量测序，我们发现TUG1参与炎性衰老下BMSC的成骨分化，BMSC中过表达TUG1可抗炎并促进成骨分化。通过生物信息学预测，TUG1能够与Sirt1竞争性结合miR-138，然后我们利用结合位点突变、荧光素酶报告基因、RIP、RNA pull down、特异性基因敲除鼠等方法，证实TUG1通过miR-138/Sirt1信号参与老年BMSC衰老、炎症、增殖和成骨分化的调控，并在老年骨质疏松发生中有一定作用。本研究揭示了TUG1通过对BMSC成骨分化和炎症的调控发挥其在老年骨质疏松中的作用，以及TUG1对miR-138/Sirt1的调控机制，为预防和治疗老年骨质疏松提供了新的线索。另外，基于对BMSC成骨分化的关注，我们发现BMSC成骨分化过程中差异LncRNA为LINC01119，并验证了LINC01119对MSC成骨分化的抑制作用，以及LINC01119通过与FZD4的结合，抑制wnt信号通路，抑制BMSC的成骨分化的分子机制，为BMSC在骨重塑、骨再生和骨组织工程中的作用和应用提供重要信息。