破骨细胞,专有的骨吸收细胞,是骨骼重塑不可或缺的。因此,了解调节破骨细胞生成的新型信号调节剂在临床上很重要。活化T细胞核因子,细胞质1(NFATc1)是破骨细胞形成中的主要转录因子,NF-κBp65亚基与NFATc1启动子的结合是其表达所必需的。众所周知,p65的DNA结合活性可以通过各种翻译后修饰来调节。包括S-亚硝化。最近的研究表明,S-亚硝基谷胱甘肽还原酶(GSNOR)介导的蛋白质脱氮通过调节基因转录参与细胞命运的决定。然而,GSNOR在破骨细胞生成中的作用仍未被探索和神秘。这里,我们研究了GSNOR介导的p65脱氮对破骨细胞生成的影响。我们的结果表明,GSNOR在体外破骨细胞形成过程中上调。此外,用化学抑制剂抑制GSNOR损害破骨细胞分化,足体带形成,和骨吸收活性。此外,GSNOR抑制增强了p65的S-亚硝化水平,排除了p65与NFATc1启动子的结合,并抑制NFATc1表达。此外,采用脂多糖(LPS)诱导的颅骨骨溶解的小鼠模型来评估GSNOR抑制剂的体内治疗效果。我们的结果表明,GSNOR抑制剂治疗通过损害小鼠破骨细胞的形成来减轻炎性骨丢失。一起来看,这些数据表明,GSNOR活性是破骨细胞形成所必需的,通过促进p65脱氮促进p65与NFATc1启动子的结合,提示GSNOR可能是治疗溶骨性疾病的潜在治疗靶点。
Osteoclasts, the exclusive bone resorptive cells, are indispensable for bone remodeling. Hence, understanding novel signaling modulators regulating osteoclastogenesis is clinically important. Nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1) is a master transcription factor in osteoclastogenesis, and binding of NF-κB p65 subunit to NFATc1 promoter is required for its expression. It is well-established that DNA binding activity of p65 can be regulated by various post-translational modifications, including S-nitrosation. Recent studies have demonstrated that S-nitrosoglutathione reductase (GSNOR)-mediated protein denitrosation participated in cell fate commitment by regulating gene transcription. However, the role of
GSNOR in osteoclastogenesis remains unexplored and enigmatic. Here, we investigated the effect of
GSNOR-mediated denitrosation of p65 on osteoclastogenesis. Our results revealed that
GSNOR was up-regulated during osteoclastogenesis in vitro. Moreover,
GSNOR inhibition with a chemical inhibitor impaired osteoclast differentiation, podosome belt formation, and bone resorption activity. Furthermore,
GSNOR inhibition enhanced the S-nitrosation level of p65, precluded the binding of p65 to NFATc1 promoter, and suppressed NFATc1 expression. In addition, mouse model of lipopolysaccharides (LPS)-induced calvarial osteolysis was employed to evaluate the therapeutic effect of GSNOR inhibitor in vivo. Our results indicated that GSNOR inhibitor treatment alleviated the inflammatory bone loss by impairing osteoclast formation in mice. Taken together, these data have shown that GSNOR activity is required for osteoclastogenesis by facilitating binding of p65 to NFATc1 promoter via promoting p65 denitrosation, suggesting that GSNOR may be a potential therapeutic target in the treatment of osteolytic diseases.