LEUKOCYTE GENE EXPRESSION IN OSTEOARTHRITIS

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目及 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 骨关节炎（OA）是一种以生物力学改变、遗传易感性和激素影响为特征的疾病。疾病过程影响整个关节结构，包括软骨、滑膜、软骨下骨，其是生长因子、细胞因子、蛋白酶和炎性介质产生的活性位点。可靠的生物标志物在这种疾病中仍然难以捉摸。我们实验室最近的研究揭示了一个意想不到的新观察结果，即OA患者的外周血白细胞（PBMC）被激活。使用基因表达阵列，显示OA-PBMC差异表达与正常对照不同的转录物簇。上调的转录本中有考克斯-2;在OA-PBMC中，姜黄素诱导的PGE 2产生是正常人的5倍。在OA-PBMC中还可以鉴定出对药物干预（考克斯-2特异性抑制剂）敏感的54种转录物的簇。独立地，人OA影响软骨显示出特定的（增殖/肿瘤）基因表达签名OA，这不同于正常和RA软骨。 本研究的目的是使用基因组技术来鉴定外周血白细胞（PBL）表达的一组新的生物标志物，这些生物标志物将在临床上用于鉴定胫股膝关节骨关节炎（OA）患者，并鉴定那些有疾病进展风险的患者。初步数据表明，PBL来自一个子集的OA患者表现出“细胞因子活化谱”，这表明白细胞暴露于刺激过程中的灌注病变关节组织。为了实现这一发现，本研究将有三个中心目标： 具体目标1将确定PBL基因表达模式是否可区分早期OA（OA-E，K-L 2级）、晚期OA（OA-A，K-L 3级）和健康对照，如半屈曲、荧光定位膝关节X线片所定义。对于这三个队列，将分析PBL基因表达谱的总体和成对比较，以确定区分以下的独特谱：1）OA与正常，和2）早期与晚期OA。研究人员将与Virginia Kraus博士合作，在一个独立的人群中验证膝关节OA的PBL基因表达谱，即杜克膝关节OA队列。 具体目标2将检查PBL基因表达谱与MRI和骨显像结果的相关性。研究人员将使用临床3.0T MRI系统对NYU-HJD的180名患者进行MRI研究，这些患者将进入为期两年的纵向队列研究。研究者将对关节软骨完整性、软骨下狭窄病变、滑膜炎/积液、边缘骨赘进行半定量分析，评估整体和个体间室评分。与Kraus博士合作，他们还将研究PBL基因表达谱与信号膝关节“滑膜炎”和“全身OA负荷”的相关性，分别由早期和晚期半定量骨密度图定义。 他们将开发OA放射学分期的多变量模型，以确定PBL基因表达谱与其他风险因素（包括BMI、COMP、骨密度和内翻/外翻畸形）的独立相关性。 具体目标3将是一项为期两年的纵向研究，以确定特定PBL基因表达模式是否可预测OA疾病进展。 研究者将评估通过MRI和半定量膝关节X线片确定的进展和未进展的OA患者。 将在0和24个月时进行影像学评价。除MRI和X线检查外，每例受试者还将接受：1）临床评价，包括BMI测定，2）疼痛和功能评估（完整WOMAC），3）血清COMP。此外，将采集血清、血浆和尿液用于未来生物标志物测定。 研究者预期，这些研究将增强我们对OA发病机制的理解，并提供一种可预测OA疾病进展的组合生物标志物。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Osteoarthritis (OA) is a disease characterized by altered biomechanics, genetic susceptibility and hormonal influences. The disease process affects the entire joint structure, including cartilage, synovial membrane, subchondral bone, which are active sites of growth factor, cytokine, protease and inflammatory mediator production. Reliable biomarkers remain elusive in this disease. Recent studies in our laboratory revealed the unexpected and novel observation that peripheral blood leukocytes (PBMCs) in OA are activated. Using gene expression array, OA-PBMCs were shown to differentially express clusters of transcripts that were distinct from normal controls. Among the upregulated transcripts was COX-2; cytokine-induced production of PGE2 was 5-fold higher in OA-PBMCs than in normal. A cluster of 54 transcripts sensitive to pharmacological intervention (COX-2 specific inhibitors) could also be identified in OA-PBMCs. Independently, human OA affected cartilage showed a specific (proliferation/neoplastic) gene expression signature in OA, which differed from normal and RA cartilage. The objective of this study is to use genomic technology to identify a novel cluster of biomarkers expressed by peripheral blood leukocytes (PBL) that will be clinically useful in the identification of patients with tibio-femoral knee osteoarthritis (OA), and to identify those patients at risk for disease progression. Preliminary data indicates that PBL derived from a subset of OA patients exhibits a "cytokine activation profile", suggesting leukocyte exposure to stimuli during the course of perfusion of diseased joint tissues. To pursue this finding, this study will have three central aims: Specific aim 1 will determine whether PBL gene expression patterns distinguish early OA (OA-E, K-L grade 2), advanced OA (OA-A, K-L grade 3) and healthy controls as defined by semi-flexed, fluoroscopically-positioned knee radiographs. For these three cohorts, overall and pair-wise comparisons of PBL gene expression profiles will be analyzed in order to identify a distinctive profile which discriminates the following: 1) OA versus normal, and 2) early versus advanced OA. The investigators will validate PBL gene expression profiles of knee OA in an independent population, the Duke Knee OA Cohort, in collaboration with Dr. Virginia Kraus. Specific aim 2 will examine the association of PBL gene expression profiles with findings on MRI and bone scintigraphy. The investigators will perform MRI studies using a clinical 3.0T MRI system on 180 patients at NYU-HJD, who will be entered into a two-year longitudinal cohort study. The investigators will perform semi-quantitative analysis of articular cartilage integrity, subchondral narrow lesions, synovitis/effusion, marginal osteophytes, assessing both global and individual compartment scores. In collaboration with Dr. Kraus they will also examine the association of PBL-gene expression profiles with signal knee "synovitis" and with "total body OA burden," as defined by early and late phase semi-quantitative bone scintigraphy, respectively. They will develop a multivariate model of OA radiographic stage to determine the independent associations of PBL-gene expression profiles with other risk factors including BMI, COMP, bone scintigraphy and varus/valgus deformities. Specific aim 3 will be a two-year longitudinal to determine whether specific PBL gene expression patterns predict OA disease progression. The investigators will assess OA patients with progression and without progression, as determined by both MRI and semi-quantitative knee radiography. Imaging evaluations will occur at 0 and 24 months. In addition to MRI and X-ray, each subject will undergo: 1) clinical evaluation including BMI determination, 2) pain and function assessment (complete WOMAC), 3) serum COMP. In addition, serum, plasma and urine will be collected for future biomarker determinations. The investigators anticipate that these studies will enhance our understanding of the pathogenesis of OA and provide a combinatorial biomarker that may predict OA disease progression.