羟丙基-β和-γ环糊精通过溶酶体相关膜蛋白 1 挽救尼曼-匹克 C1 突变细胞中的胆固醇积累。
Hydroxypropyl-beta and -gamma cyclodextrins rescue cholesterol accumulation in Niemann-Pick C1 mutant cell via lysosome-associated membrane protein 1.
机构信息
Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, TN, 37208, USA.
Cyclolab Cyclodextrin Research and Development Laboratory Ltd., H-1097, Budapest, Hungary.
出版信息
Cell Death Dis. 2018 Oct 3;9(10):1019. doi: 10.1038/s41419-018-1056-1.
Niemann-Pick type C (NPC) disease is a fatal hereditary neurodegenerative disorder characterized by a massive accumulation of cholesterol in lysosomes and late endosomes due to a defect in intracellular cholesterol trafficking. Dysfunction in intracellular cholesterol trafficking is responsible for about 50 rare inherited lysosomal storage disorders including NPC. The lysosomal proteins NPC1 and NPC2 play a crucial role in trafficking of cholesterol from late endosomes and lysosomes to other cellular compartments. However, the detailed mechanisms of cholesterol trafficking at the late endosomes/lysosomes (LE/LY) are poorly understood. Studies showed that 2-hydroxypropyl-β-cyclodextrin (HPβCD) alleviates the cholesterol accumulation defect in animal model and has been approved for a phase 2b/3 clinical trial for NPC. HPβCD is known to bind cholesterol; however, the mechanisms how HPβCD mediates the exit of cholesterol from the LE/LY compartments are still unknown. Further, another cyclodextrin (CD) derivative, 2-hydroxypropyl-γ-cyclodextrin (HPγCD), was shown to reduce intracellular cholesterol accumulation in NPC patient cells and NPC mice model. Herein, we identified a number of candidate proteins differentially expressed in NPC patient-derived cells compared to cells derived from a healthy donor using a proteomic approach. Interestingly, both HPβCD and HPγCD treatments modulated the expression of most of these NPC-specific proteins. Data showed that treatment with both CDs induces the expression of the lysosome-associated membrane protein 1 (LAMP-1) in NPC patient-derived cells. Remarkably, LAMP-1 overexpression in HeLa cells rescued U18666A-induced cholesterol accumulation suggesting a role of LAMP-1 in cholesterol trafficking. We propose that HPβCD and HPγCD facilitate cholesterol export from the LE/LY compartments via the LAMP-1 protein, which may play a crucial role in cholesterol trafficking at the LE/LY compartments when there is no functional NPC1 protein. Together, this study uncovers new cellular mechanisms for cholesterol trafficking, which will contribute to development of novel therapeutic approaches for lysosomal storage diseases.
尼曼-匹克 C 型(NPC)疾病是一种致命的遗传性神经退行性疾病,其特征是由于细胞内胆固醇转运缺陷,溶酶体和晚期内体中胆固醇大量积累。细胞内胆固醇转运功能障碍是导致大约 50 种罕见遗传性溶酶体贮积症的原因,包括 NPC。溶酶体蛋白 NPC1 和 NPC2 在胆固醇从晚期内体和溶酶体转运到其他细胞区室中发挥关键作用。然而,晚期内体/溶酶体(LE/LY)中的胆固醇转运的详细机制尚不清楚。研究表明,2-羟丙基-β-环糊精(HPβCD)可缓解动物模型中的胆固醇积累缺陷,并已获准进行 NPC 的 2b/3 期临床试验。已知 HPβCD 与胆固醇结合;然而,HPβCD 介导胆固醇从 LE/LY 区室中排出的机制尚不清楚。此外,另一种环糊精(CD)衍生物 2-羟丙基-γ-环糊精(HPγCD)已被证明可减少 NPC 患者细胞和 NPC 小鼠模型中的细胞内胆固醇积累。在此,我们使用蛋白质组学方法鉴定了与来自健康供体的细胞相比,在 NPC 患者衍生细胞中差异表达的许多候选蛋白。有趣的是,HPβCD 和 HPγCD 处理均调节了大多数这些 NPC 特异性蛋白的表达。数据显示,两种 CD 处理均诱导 NPC 患者衍生细胞中溶酶体相关膜蛋白 1(LAMP-1)的表达。值得注意的是,在 HeLa 细胞中过表达 LAMP-1 可挽救 U18666A 诱导的胆固醇积累,表明 LAMP-1 在胆固醇转运中起作用。我们提出,HPβCD 和 HPγCD 通过 LAMP-1 蛋白促进 LE/LY 区室中的胆固醇外排,当没有功能性 NPC1 蛋白时,LAMP-1 可能在 LE/LY 区室中的胆固醇转运中起关键作用。总之,这项研究揭示了胆固醇转运的新细胞机制,这将有助于开发治疗溶酶体贮积症的新疗法。