Novel Therapies and Biomarkers for the Mucopolysaccharidoses

粘多糖贮积症（MPS）是一种遗传性结缔组织疾病， 糖胺聚糖（GAG）降解所需的特定溶酶体酶的活性。中 涉及多个器官系统，骨骼和关节受到严重影响。虽然有几种治疗方法 已经或目前正在评估MPS患者，对骨骼和关节的积极影响已经 有限公司此外，没有合适的生物标志物可用于监测这些药物的有效性。 治疗骨骼和关节。本研究的基本假设是MPS中的GAG储存 个体激活Toll样受体-4（TLR 4）信号通路，导致一种复杂的 炎症、凋亡和细胞增殖。这反过来又会导致异常的结缔组织基质 体内平衡，导致骨和关节破坏。本项目提出了三个具体目标， MPS VI型的大鼠和猫模型。目的1：我们将进一步研究GAG诱导的细胞凋亡的机制。 通过a）使用Toll样受体4（TLR 4）报告细胞系和 敲除小鼠以评估GAG对TLR 4活化的直接作用，B）继续定量前- MPS软骨细胞和滑膜细胞提取物和培养基中的炎性和促凋亡蛋白，和c） 检查导致GAG介导的两种重要信号脂质神经酰胺异常的机制 和鞘氨醇-1-磷酸（S1 P）。目的2：我们将探索使用血浆和滑液作为来源 a）从MPS疾病的各个阶段的MPS VI猫获得这些材料， 疾病严重程度，并比较几种促炎/促凋亡蛋白和脂质的水平 （神经酰胺和S1 P）与年龄匹配的正常猫中发现的那些相比。我们还将比较血浆中的GAG水平 和来自MPS VI猫的滑液与在尿液中发现的那些相比，B）使用MPS VI猫滑液用于a 蛋白质组学分析，旨在鉴定在该疾病中异常表达的新蛋白质，以及c） 在通过关节内注射治疗之前和之后从人MPS VI患者获得血浆和滑液， 酶替代疗法，并评估从动物中鉴定的几种生物标志物的表达 上面提到的实验。目的3：根据我们的初步研究结果，我们将评估TNF-α的疗效。 抑制剂和抗凋亡药物。要研究的四种分子中的每一种都已经 在关节炎的动物模型中显示出有效性，并且一种（Remicade）是临床上可获得的。

The Mucopolysaccharidoses (MPS) are inherited, connective tissue disorders that result from the deficient activities of specific lysosomal enzymes required for glycosaminoglycan (GAG) degradation. Among the various organ systems involved, the bones and joints are severely affected. Although several therapies have been or are currently being evaluated for MPS patients, the positive effects on bones and joints have been limited. In addition, there are no appropriate biomarkers that can be used to monitor the effectiveness of these therapies for bones and joints. The underlying hypothesis of this research is that GAG storage in MPS individuals activates Toll-like receptor-4 (TLR4) signaling pathways, leading to a complex pattern of inflammation, apoptosis and cell proliferation. This, in turn, causes abnormal connective tissue matrix homeostasis, resulting in bone and joint destruction. Three specific aims are proposed in this project using the rat and cat models of MPS Type VI. Aim 1: We will further examine the mechanisms underlying GAG-induced signaling abnormalities in MPS connective tissues by a) using Toll-like receptor 4 (TLR4) reporter cell lines and knock-out mice to evaluate the direct effects of GAGs on TLR4 activation, b) continuing to quantify pro- inflammatory and pro-apoptotic proteins in MPS chondrocyte and synovial cell extracts and media, and c) examining the mechanisms leading to GAG-mediated abnormalities in two important signaling lipids, ceramide and sphingosine-1-phosphate (S1P). Aim 2: We will explore the use of plasma and synovial fluid as sources of biomarkers for the MPS disorders by a) obtaining these materials from MPS VI cats of various stages of disease severity, and comparing the levels of several pro-inflammatory/pro-apoptotic proteins and lipids (ceramide and S1P) to those found in age-matched normal cats. We will also compare GAG levels in plasma and synovial fluid from the MPS VI cats to those found in urine, b) using the MPS VI cat synovial fluid for a proteomics analysis aimed at identifying novel proteins that are abnormally expressed in this disease, and c) obtaining plasma and synovial fluid from human MPS VI patients before and after treatment by intra-articular enzyme replacement therapy, and evaluating the expression of several biomarkers identified from the animal experiments outlined above. Aim 3: Based on our preliminary findings, we will evaluate the efficacy of TNF-¿ inhibitors and anti-apoptotic drugs in the MPS VI rats. Each of the four molecules to be studied has already shown efficacy in animal models of arthritis, and one (Remicade") is clinically available.