Viral and Genetic Regulation of Abnormal OCL Activity in PD

病毒和遗传因素都与Paget病(PD)的发病有关。然而，它们影响破骨细胞(OCL)形成和帕金森病活性的分子机制尚不清楚。我们的假设是，麻疹病毒核蛋白(MVNP)主要通过激活两个kB激酶(IKK)相关的KKE(也称为IKK-/)和TRAK1(TRAF1)以及增加RIP1和TRAF2水平来增加NFicB信号，从而介导其对OCL前体的影响。这会导致IL-6和维生素D受体共激活因子TAFM-17的上调，并增加OCL的形成。MVNP还通过增加NFATd的表达和激活来驱动多潜能细胞走向OCL谱系。与PD相关的p62P392L突变通过进一步增加NFxB信号对肿瘤坏死因子-ct和RANKL的反应以及增加p38MAPK对RANKL、肿瘤坏死因子-α和1，25-(OH)2D3的激活来增强MVNP的作用。为了支持这一假说，我们最近发现，MVNP的表达增加了RIP1、TRAF2和p65 NFicB，从而增强了NFicB的结构性激活，并增加了NFicB对肿瘤坏死因子-α和RANKL的反应性。我们还发现，MVNP增加了NFATd，并协同激活NFATc1驱动的基因转录，与NFATd‘或RANKL一起，并诱导IL-6和TAFn-17。此外，p62p392L突变激活了NFicB，增加了OCL前体对RANKL和TNF-α的敏感性。MVNP还与IKKE和TBK1相互作用激活NFKB，但它们在帕金森病中的作用尚不清楚。在本项目中，我们将：1.确定MVNP对NFKB的激活和Pagtic OCL的形成是否源于规范途径的改变和/或涉及IKKepsilon/TBK1激活的替代途径的利用，以及MVNP和p62P392L在这些途径上的共同表达的影响。2.确定MVNP激活NFKB是否足以诱导IL-6的产生，或者是否还需要其他机制，以及p62R392L和MVNP共同表达对上述分子机制的影响(S)。3.确定MVNP与NFATd的协同作用是由于NFATd激活的调节还是NFATd的辅因子。上述对MVNP和p62p392L在OCL形成中作用的分子机制的研究将为PD的发病机制提供重要的见解，并与项目2中提出的细胞和体内研究直接相关。

Both viral and genetic factors have been implicated in the pathogenesis of Paget's disease (PD). However, the molecular mechanisms responsible for their effect on osteoclast (OCL) formation and activity in PD are unclear. It is our hypothesis that measles virus nucleoprotein (MVNP) mediates its effects in OCL precursors predominantly through increased NFicB signaling via activation of the two kB kinase (IKK)-related kinases IKKe (also called IKK-/) and TANK-binding kinase 1 (TBK1) and increased levels of RIP1 and TRAF2. This results in upregulation of IL-6 and a vitamin D receptor coactivator TAFM-17 and increases OCL formation. MVNP also drives multi-potential cells towards the OCL lineage through increased expression and activation of NFATd. The p62P392L mutation linked to PD enhances the effects of MVNP by further increasing NFxB signaling in response to TNF-ct and RANKL as well as increasing p38 MAPK activation in response to RANKL, TNF-alpha and 1,25-(OH)2D3. In support of this hypothesis, we recently found that MVNP expression increases RIP1, TRAF2, and p65 NFicB resulting in enhanced constitutive activation of NFicB, and increased NFicB responsivity to TNF-alpha and RANKL. We also found that MVNP increases NFATd and synergistically activates NFATcl-driven gene transcription, with either NFATd 'or RANKL, and induces IL-6 and TAFn-17. In addition, the p62p392L mutation activates NFicB and increases the sensitivity of OCL precursors to RANKL and TNF-alpha. MVNP also interacts with IKKe and TBK1 to activate NFKB but their role in PD are unknown. In this project we will: 1. Determine if MVNP activation of NFKB and induction of pagetic OCL formation results from alterations of the canonical pathway and/or utilization of an alternative pathway that involves activation of IKKepsilon/TBK1 and the effects of co-expression of MVNP and p62P392L on these pathways. 2. Determine if NFKB activation by MVNP is sufficient for induction of IL-6 or if other mechanisms are also necessary, and the effects of co-expression of p62R392L and MVNP on the molecular mechanlsm(s) identified above. 3. Determine if the synergy of MVNP with NFATd is due to modulation of NFATd activation or of a cofactor of NFATd. The studies of the molecular mechanisms responsible for MVNP and p62p392L effects on OCL formation outlined above" will provide important insight into the pathogenesis of PD and are directly linked to the cellular and in vivo studies proposed in Project 2,