Non-Type I Kinase Inhibition of HIV-Induced Synaptodendritic Damage/Leukocyte Inf

描述（由申请人提供）：联合抗逆转录病毒治疗（cART）减缓了发病，但没有改变HIV相关神经系统疾病的患病率。在老年患者群体中，尽管cART能够将中枢神经系统中的病毒载量降低到无法检测的水平，但HIV-1相关神经认知障碍（HAND）的患病率可能正在增加，因此一半的HIV感染者可能会出现HAND症状。HAND的特征包括：1)炎症细胞因子和趋化因子的失调，2)免疫细胞（单核细胞）向中枢神经系统（CNS）募集，3)胶质细胞的病毒感染导致其正常功能中断，4)广泛的突触树突损伤。许多炎症介质参与了这一级联反应，其中TNF-1的释放和信号可能起着主要的中心作用。已经确定在HAND患者的脑脊液和死后脑组织中有更有限的一组介质被上调。这些经过翻译验证的介质/效应物包括TNF-1、单核细胞化学引诱剂MCP-1和混合谱系激酶3 (MLK3)， MLK3是MAPK激酶调节炎症途径的重要控制点。我们与罗切斯特大学医学中心的Harris Gelbard博士和Stephen Dewhurst博士合作，确定了URMC-099，一种抑制MLK3并阻断MCP-1和TNF-1以及其他炎症介质在HIV-1刺激的人类巨噬细胞中的上调的化合物。罗彻斯特大学的研究小组开发了一种体内成像分析方法，以评估HIV神经毒素的影响和可能改善其影响的潜在药物。在小鼠脑内暴露于HIV-1 Tat的体内脑成像实验表明，口服URMC-099可防止Tat诱导的白细胞浸润和小胶质细胞活化，并显著逆转Tat诱导的突触结构损伤。突触结构损伤是HAND损伤认知记忆的关键病理过程。Califia Bio正在通过开发针对HAND的小分子抑制剂，识别和验证导致HAND的途径中涉及的主要“控制中心”（即关键激酶）。我们假设，与选择性抑制MLK3的化合物相比，具有选择性抑制MLK激酶家族和尚未确定的激酶活性的化合物，可能更有可能成功阻断与疾病病理生理相关的重要信号网络，部分原因是MLK信号通路的功能冗余。我们已经对URMC-099进行了全基因组范围的活性筛选；我们现在还发现了具有非常不同分子支架的MLK抑制剂，它们不能利用MLK激酶家族中相同的结合模式。本应用程序的目的是优化和表征这些新的先导系列，以了解它们对HAND中心的促炎介质的干扰能力，并确定最佳化合物所表现出的激酶抑制模式。在第二阶段，我们将寻求在动物模型中具有疗效的化合物。

DESCRIPTION (provided by applicant): Combination antiretroviral therapy (cART) has slowed the onset, but has not altered the prevalence of HIV - associated neurologic disease. In aging patient populations, the prevalence of HIV-1 associated neurocognitive disorder (HAND) may be increasing, despite the ability of cART to reduce viral load in the CNS to undetectable levels, such that half of the population living with HIV may experience symptoms of HAND. The hallmarks of HAND include: 1) a dysregulation of inflammatory cytokines and chemokines, 2) the recruitment of immune cells (monocytes) to the central nervous system (CNS), 3) the viral infection of glia leading to interruption of their normal function, and 4) extensive synaptodendritic damage. A host of inflammatory mediators are implicated in this cascade, where TNF-1 release and signaling likely play a major central role. A more limited subset of mediators has been identified as being up-regulated in the cerebrospinal fluid and post- mortem brain tissues of HAND patients. These translationally validated mediators/effectors include TNF-1, the monocyte chemoattractant MCP-1, and mixed-lineage kinase 3 (MLK3), an important control point in MAPK kinase regulated inflammation pathways. In collaboration with Dr. Harris Gelbard and Stephen Dewhurst at the University of Rochester Medical Center, we have identified URMC-099, a compound that inhibits MLK3 and blocks up-regulation of MCP-1 and TNF-1 and other inflammatory mediators in HIV-1 Tat stimulated human macrophages. The University of Rochester team has developed an in vivo imaging assay to evaluate the effects of HIV neurotoxins and potential drugs that may ameliorate their effects. In vivo brain imaging experiments in mice exposed intracerebrally to HIV-1 Tat have shown that i.p. administration of URMC-099 prevents Tat-induced leukocyte infiltration and microglial activation, and dramatically reverses Tat-induced damage to synaptic architecture. The damage to synaptic architecture is the key pathological process of HAND in damaging cognition and memory. Califia Bio is identifying and validating major "control hubs" (i.e. critical kinases) involved in the pathways leading to HAND by developing small molecule inhibitors directed against them. We hypothesize that a compound with selective activity against the MLK family of kinases, and as yet unidentified kinases, may be more likely to be successful in blocking important signaling networks involved in the pathophysiology of the disease than a compound that selectively inhibits only MLK3, due in part to the functional redundancy of MLK signaling pathways. We have conducted kinome wide screens of activity for URMC-099; we also have now discovered lead MLK inhibitors with very different molecular scaffolds that cannot utilize the same binding modes in the MLK family of kinases. The goal of this application is to optimize and characterize these new lead series for their ability to interfere with pro-inflammatory mediators central to HAND and to identify the patterns of kinase inhibition exhibited by the best compounds. In Phase 2 we will seek development compounds with efficacy in animal models of HAND. PUBLIC HEALTH RELEVANCE: This Phase I SBIR proposal is aimed at the discovery of potential small molecule therapeutics to treat HIV/AIDS-associated mental and neurological disorders. In 2007, 33.2 million people worldwide were infected with HIV/AIDS. In the United States, it is estimated that more than 1 million individuals live with HIV, and an estimated 40,000 new HIV infections occur each year. It is estimated that as the population of HIV infected individuals ages, under the supportive care of combined antiretroviral therapy, as many as 50 percent of these patients will experience symptoms of HIV-associated neurological disease, which may range from severe dementia, to neuropathies and motor dysfunction.