Understanding the skeletal phenotype of Gaucher disease

了解戈谢病的骨骼表型

基本信息

批准号：
9127133
负责人：
PRAMOD K MISTRY
金额：
$ 49.76万
依托单位：
ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-09-16 至 2018-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9127133
关键词：
Adamantane Affect Apoptosis Ashkenazim Autoimmune Process Automobile Driving Bone Diseases Bone Resorption Catabolism Cell Culture Techniques Cell Cycle Cell Lineage Cells Ceramide glucosyltransferase Ceramides Collaborations Data Defect Disease Disease susceptibility Embryo Employee Strikes Enzymes Exposure to Fracture Functional disorder Gaucher Disease Genes Genetic Genets Glucosylceramides Glycoside Hydrolases Goals Health Hematopoietic Hepatosplenomegaly Hereditary Disease Human Immune In Vitro Incidence Infiltration Investigation Knock-in Lipids Live Birth Malignant Neoplasms Marrow Mediating Mesenchymal Molecular Mus Mutation Neoplasms Nerve Degeneration Non-Neuronopathic Gaucher Disease Osteoblasts Osteoclasts Osteocytes Osteogenesis Osteopenia Osteoporosis Pathway interactions Patients Phenocopy Phenotype Population Risk Role Serum Sphingolipids Sphingosine Stromal Cells Tartrates Visceral Visceromegaly base bone bone cell bone loss bone turnover cell type cytokine cytopenia dentin matrix protein 1 enzyme replacement therapy follower of religion Jewish glucosylceramidase glucosylsphingosine high risk human disease imiglucerase in vivo inhibitor/antagonist medical schools mouse model mutant new therapeutic target novel therapeutics osteoblast differentiation promoter skeletal skeletal disorder sphingosine 1-phosphate tool

项目摘要

DESCRIPTION (provided by applicant): Gaucher Disease is a debilitating lysosomal storage disorder characterized by striking visceral enlargement and a high risk of crippling fractures. It s caused by mutations in the glucocerebrosidase (GBA1) gene that impair -glycosidase, an enzyme required for sphingolipid catabolism. While enzyme replacement therapy (imiglucerase) is effective, its effects on fracture risk are not fully understood. To identify new therapeutic targets for non-neuronopathic type 1 GD (GD1), attempts have been made to knock in mutations and delete Gba1 in mice. We have successfully deleted Gba1 in cells of the hematopoietic and mesenchymal cell lineage using an Mx1 promoter. Our Mx1-Cre:GD1 mouse phenocopies human GD1 almost in its entirety, displaying severe hepatosplenomegaly, cytopenia, and osteoporosis. The mouse also displays Th1 and Th2 hypercytokinemia and immune cell defects, which might contribute not only to the increased risk of lymphoproliferative malignancy, but also to the bone disease. Our data further show that the osteoporosis is due to a defect in osteoblastic bone formation, not osteoclastic bone resorption. We find that reduced osteoblast viability noted in stromal cell cultures from Mx1-Cre:GD1 mice is recapitulated by exposure to sphingosine, a sphingolipid that accumulates in GD1. We hypothesize that, despite the immune cell dysfunction that may affect bone, the osteopenia noted in Mx1-Cre:GD1 mice arises mainly from the direct action of sphingosine on the osteoblast, thus lowering bone formation. Therefore, in Specific Aim 1, we will determine whether the bone formation defect is autonomous, and if so, which bone cell - osteoblast, osteocyte, or osteoclast - drives it. For this we will delete Gba1 in the three cell types, respectively, using Col2.3-Cre, Dmp1-Cre and CathK-Cre mice. In Specific Aim 2, we will lower sphingolipid levels by inhibiting or deleting glucosylceramide synthase (Gcs), an enzyme upstream of Gba1. For this, we will inject Mx1-Cre:GD1 mice with eliglustat tartrate, a Gcs inhibitor, and, in parallel, generate mice lacking Gba1 and Gcs in the same cells. Of note, we find that eliglustat tartrate lowers serum GL-1 and reverses the visceromegaly and cytopenia in GD1 patients. Finally, in Specific Aim 3, to hone in on the specific lipid that causes osteoblast inhibition, we will lower sphingosine, but not LysoGL-1 levels. We hypothesize that, as the extralysosomal enzyme Gba2 converts LysoGL-1 to sphingosine, Gba2 deletion or its inhibition by AMP-DNM should reverse the osteopenia in Mx1-Cre:GD1 mice. To further examine the action of sphingosine and other sphingolipids on the osteoblast, we will study differentiation, cell cycling and apoptosis in vitro. Our investigations should not only define the target cell and responsible molecule for the osteopenia in GD1, but also identify new therapeutic targets, both upstream (Gcs) and downstream (Gba2) of Gba1, for GD1-associated and other common types of osteoporosis.

描述（由申请人提供）：Gaucher病是一种令人衰弱的溶酶体储存障碍，其特征是内脏肿大和严重骨折的高风险。它是由葡萄糖脑苷酶（GBA1）基因突变引起的，损害了糖苷酶，这是鞘脂分解代谢所需的酶。虽然酶替代疗法（IMIGLUCERASE）有效，但其对骨折风险的影响尚未完全了解。为了确定非神经性1型GD（GD1）的新治疗靶标（GD1）试图敲击突变并删除小鼠的GBA1。我们使用MX1启动子成功地在造血和间充质细胞谱系的细胞中成功删除了GBA1。我们的MX1-CRE：GD1小鼠该表蛋白具有人为gd1的全部，显示出严重的肝肾上腺全脂，细胞质和骨质疏松症。该小鼠还显示TH1和TH2高胞菌血症和免疫细胞缺陷，这不仅可能导致淋巴增生性恶性肿瘤的风险增加，还导致骨骼疾病。我们的数据进一步表明，骨质疏松症是由于成骨细胞骨形成的缺陷，而不是整骨骨的吸收。我们发现，通过暴露于MX1-CRE：GD1小鼠的基质细胞培养物中指出的成骨细胞生存力降低，通过暴露于鞘氨醇（一种在GD1中积累的鞘脂）概括。我们假设，尽管可能影响骨骼的免疫细胞功能障碍，但在MX1-CRE：GD1小鼠中指出的骨质减少症主要来自鞘氨醇对成骨细胞的直接作用，从而降低了骨形成。因此，在特定的目标1中，我们将确定骨形成缺陷是自主的，如果是的，则是骨细胞 - 成骨细胞，骨细胞或骨细胞 - 驱动它。为此，我们将使用COL2.3-CRE，DMP1-CRE和CATEK-CRE小鼠分别删除三种细胞类型中的GBA1。在特定的目标2中，我们将通过抑制或删除GBA1上游的酶（GCS）来降低鞘脂水平。为此，我们将向MX1-CRE：GD1小鼠注入eliglustat tartrate，一种GCS抑制剂，并并行生成在同一细胞中缺乏GBA1和GC的小鼠。值得注意的是，我们发现Eliglustat降低了血清GL-1，并逆转GD1患者的内脏瘤和细胞质。最后，在特定的目标3中，要磨练引起成骨细胞抑制的特定脂质，我们将降低鞘氨酸，但不会降低溶血菌1水平。我们假设，随着外染色体酶GBA2将Lysogl-1转换为鞘氨醇，GBA2缺失或AMP-DNM抑制作用应扭转MX1-CRE中的骨质骨减少症：GD1小鼠。为了进一步研究鞘氨醇和其他鞘脂对成骨细胞的作用，我们将在体外研究分化，细胞循环和凋亡。我们的研究不仅应定义GD1中骨质减少症的靶细胞和负责分子，而且还应确定GBA1的上游（GCS）和下游（GBA2）的新的治疗靶标，用于GD1相关和其他常见类型的骨质疏松症。