Immunopathology Lab, Department of Bio-sciences, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, India.
J Cell Physiol. 2020 Dec;235(12):9497-9509. doi: 10.1002/jcp.29757. Epub 2020 May 5.
Bone erosion is the major cause of deformities in autoimmune disease conditions such as osteoporosis and rheumatoid arthritis. Aberrant receptor activator of nuclear factor kappa B ligand (RANKL) secretion in bone disorders have been implicated to promote uncontrolled osteoclast differentiation through the regulation of nuclear factor of activated T cells 1 (NFATc1) transcription factor. This phenomenon is governed by several molecular factors including microRNAs, which are under-expressed during disease progression. This report focuses on elucidating the molecular mechanism of miR-506-3p towards the RANKL/NFATc1 pathway. miR-506-3p showed high binding affinity towards NFATc1 (ΔG = -22.4 kcal/mol). Bone marrow-derived macrophages (BMMs) isolated from rats stimulated with RANKL (100 ng/ml) showed active expression of NFATc1 which differentiated into mature osteoclasts. Moreover, NFATc1 activation resulted in downstream secretion of various bone resorptive enzymes (cathepsin K, carbonic anhydrase II, tartarate acid phosphatase, and matrix metalloproteinase 9) which lead to active bone resorption. However, transfection of miR-506-3p resulted in selective repression of NFATc1 inside the cells. This further resulted in the diminished release of bone resorptive enzymes that were essential for the degradation of the bone. Overall, we predict that miR-506-3p can be used as a molecular intervention for RANKL/NFATc1 mediated osteoclastogenesis.
骨侵蚀是骨质疏松症和类风湿性关节炎等自身免疫性疾病中骨骼畸形的主要原因。骨疾病中异常的核因子 κB 配体受体激活剂 (RANKL) 的分泌被认为通过调节激活 T 细胞核因子 1 (NFATc1) 转录因子来促进破骨细胞的不受控制分化。这种现象受几种分子因素控制,包括在疾病进展过程中表达下调的 microRNAs。本报告重点阐述了 miR-506-3p 对 RANKL/NFATc1 通路的分子机制。miR-506-3p 与 NFATc1 具有高结合亲和力(ΔG=-22.4 kcal/mol)。用 RANKL(100ng/ml)刺激大鼠分离的骨髓来源巨噬细胞(BMM)显示 NFATc1 的活性表达,NFATc1 分化为成熟的破骨细胞。此外,NFATc1 的激活导致各种骨吸收酶(组织蛋白酶 K、碳酸酐酶 II、酒石酸磷酸酶和基质金属蛋白酶 9)的下游分泌,从而导致骨吸收活性增强。然而,miR-506-3p 的转染导致细胞内 NFATc1 的选择性抑制。这进一步导致对降解骨骼至关重要的骨吸收酶的释放减少。总的来说,我们预测 miR-506-3p 可作为 RANKL/NFATc1 介导的破骨细胞生成的分子干预手段。