PLA Institute of Orthopaedics, Xijing Hospital, Fourth Military Medical University, Xi'an, China; Department of Anatomy, Histology and Embryology and K.K. Leung Brain Research Centre, Fourth Military Medical University, Xi'an, China.
Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
Arch Med Res. 2023 Jul;54(5):102853. doi: 10.1016/j.arcmed.2023.102853. Epub 2023 Jul 16.
Dysregulation of MSCs differentiation is associated with many pathophysiological processes. Genetically modified MSCs transplantation helps restore bone loss efficiently.
BMSCs-specific QKI overexpressing and knockdown mice were built to explore QKI's role in bone formation and fat accumulation. Primary BMSCs with QKI overexpression and knockout were subjected to osteogenic and adipogenic differentiation. ALP staining and oil red O staining were performed to evaluate the differences between the groups. RNA immunoprecipitation was performed to identify the QKI-related pathway. QKI deficient BMSCs were transplanted into mice with glucocorticoid-induced osteoporosis to evaluate its therapeutic potential.
Mice harboring BMSC-specific transgenic QKI exhibited reduced bone mass, while BMSC-specific QKI-deficient mice showed an increase in bone mass. Osteogenic differentiation of QKI deficient BMSCs was promoted and adipogenic differentiation was inhibited, while QKI overexpression in BMSCs displayed the opposite effects. To define the underlying mechanisms, RIP sequencing was performed. Wnt pathway-related genes were the putative direct target mRNAs of QKI, Canonical Wnt pathway activation was involved in QKI's effects on osteogenic differentiation. RNA immunoprecipitation quantitative real-time Polymerase Chain Reaction (PCR) and RNA fluorescence in situ hybridization experiments further validated that QKI repressed the expressions of Wnt5b, Fzd7, Dvl3 and β-catenin via direct binding to their putative mRNA specific sites. Glucocorticoid-induced osteoporotic mice transplanted with QKI deficient BMSCs exhibited less bone loss compared with mice transplanted with control BMSCs.
QKI suppressed BMSCs osteogenic differentiation by downregulating the expressions of Wnt5b, Fzd7, Dvl3 and β-catenin. Loss of QKI in BMSCs transplantation may provide a new strategy for the treatment of orthopedic diseases such as osteoporosis.
间充质干细胞分化失调与许多病理生理过程有关。基因修饰间充质干细胞移植有助于有效恢复骨丢失。
构建了骨髓间充质干细胞特异性 QKI 过表达和敲低小鼠，以探讨 QKI 在骨形成和脂肪堆积中的作用。对 QKI 过表达和敲除的原代骨髓间充质干细胞进行成骨和成脂分化。进行碱性磷酸酶染色和油红 O 染色，以评估各组之间的差异。进行 RNA 免疫沉淀以鉴定与 QKI 相关的途径。将 QKI 缺陷的骨髓间充质干细胞移植到糖皮质激素诱导的骨质疏松症小鼠中，以评估其治疗潜力。
携带骨髓间充质干细胞特异性转基因 QKI 的小鼠表现出骨量减少，而骨髓间充质干细胞特异性 QKI 缺陷小鼠则表现出骨量增加。QKI 缺陷的骨髓间充质干细胞的成骨分化得到促进，而脂肪分化受到抑制，而骨髓间充质干细胞中的 QKI 过表达则表现出相反的效果。为了定义潜在的机制，进行了 RNA 免疫沉淀测序。Wnt 途径相关基因是 QKI 的假定直接靶标 mRNA，经典 Wnt 途径的激活涉及 QKI 对成骨分化的影响。RNA 免疫沉淀定量实时聚合酶链反应（PCR）和 RNA 荧光原位杂交实验进一步验证了 QKI 通过直接结合其假定的 mRNA 特异性位点来抑制 Wnt5b、Fzd7、Dvl3 和 β-连环蛋白的表达。与移植对照骨髓间充质干细胞的糖皮质激素诱导骨质疏松症小鼠相比，移植 QKI 缺陷的骨髓间充质干细胞的小鼠表现出较少的骨丢失。
QKI 通过下调 Wnt5b、Fzd7、Dvl3 和 β-连环蛋白的表达来抑制骨髓间充质干细胞的成骨分化。骨髓间充质干细胞中 QKI 的缺失可能为骨质疏松症等骨科疾病的治疗提供新策略。
