The Molecular Basis of NCL

描述(申请人提供)：神经性蜡样脂褐素沉积症(NCLS)是一种隐性遗传性儿童疾病，在美国的发病率约为1：12,500。NCL是一种选择性受损的线粒体自噬问题，因为中枢神经系统中的神经细胞特征是自动荧光沉积中积累的ATP合成酶亚单位c。遗传证据导致了这样的假设，即不同的NCL基因座调节线粒体自噬的不同步骤。大多数NCL(JNCL；Batten病)是由于CLN3的基因组缺失突变导致的，该突变破坏了与pH调节有关的巴丁蛋白。更严重的变异型晚期婴儿(VLINCL)疾病是由CLN6突变引起的。为了实现我们之前的目标，我们已经确定了CLN6，它编码linclin，一种可能定位于内质网(ER)的膜蛋白。除了不同的亚细胞定位外，linclin和battenin还与不同的配对蛋白相关联。在这一更新应用中，我们建议使用遗传vLINCL CLN6[NCLF]和JNCL Cln3[Delta-EX7/8]小鼠和细胞培养模型，在患者细胞中观察到缺陷，以描绘需要linclin和battenin功能的神经细胞中线粒体自噬的离散步骤。目的1验证Linclin和Battenin在野生型神经细胞线粒体自噬中的作用分别涉及内质网和内质粒/溶酶体区活动的假说。目的2将评估与linclin或battenin功能有关的候选伙伴蛋白是否是野生型神经细胞正常线粒体自噬所必需的。目的3将确定vLINCL和JNCL突变是否阻止纯合子突变CLN6[NCLF]和Cln3[Delta-EX7/8]神经细胞线粒体自噬的不同步骤。目的4将通过鉴定FDA批准的可能改变CLN6[NCLF]和Cln3[Delta-EX7/8]神经细胞异常表型的化合物，来检验线粒体功能障碍可能与线粒体自噬受损有关的假设。这些研究有望揭示神经细胞线粒体自噬中的linclin和Battenin活性，揭示JNCL和vLINCL的病理生理学，并刺激这些毁灭性疾病的有效治疗方法的开发。

DESCRIPTION (provided by applicant): The neuronal ceroid lipofuscinosis (NCLs) are recessively inherited childhood disorders, with an incidence of approximately 1:12,500 in the U.S. NCL is a problem of selectively impaired mitochondrial autophagy, as neuronal cells in the CNS feature the accumulation of ATP synthase subunit c in autofluorescent deposits. The genetic evidence leads to the hypothesis that different NCL loci regulate distinct steps in mitochondrial autophagy. Most cases of NCL (JNCL; Batten disease) are due to a genomic deletion mutation in CLN3 that disrupts battenin, an endosomal/lysosomal membrane protein implicated in pH regulation. The more severe variant late infantile (vLINCL) form of the disease is caused by mutations in CLN6. Fulfilling our previous aims, we have identified CLN6, which encodes linclin, a membrane protein that may localize to the endoplasmic reticulum (ER). In addition to different subcellular localizations, linclin and battenin associate with different sets of partner proteins. In this renewal application, we propose to use genetic vLINCL Cln6[nclf] and JNCL Cln3 [delta-ex7/8] mouse and cell culture models, which exhibit deficits observed in patient cells, to delineate the discrete steps in mitochondrial autophagy in neuronal cells that require linclin and battenin function. Aim 1 will test the hypothesis that linclin and battenin functions in mitochondrial autophagy in wild-type neuronal cells entail activities in specialized ER and endosomal/lysosomal compartments, respectively. Aim 2 will assess whether candidate partner proteins implicated in linclin or battenin function are required for normal mitochondrial autophagy in wild-type neuronal cells. Aim 3 will determine whether vLINCL and JNCL mutations block different steps in mitochondrial autophagy in homozygous mutant Cln6[nclf] and Cln3[delta-ex7/8] neuronal cells. Aim 4 will test the hypothesis that mitochondrial dysfunction may be linked to impaired mitochondrial autophagy, by identifying FDA approved compounds that may alter both abnormal phenotypes in Cln6[nclf] and Cln3[delta-ex7/8] neuronal cells. These studies are expected to uncover linclin and battenin activities in mitochondrial autophagy in neuronal cells, shedding light on the pathophysiology of JNCL and vLINCL and spurring the development of effective therapies for these devastating disorders.