Beta-Amyloid & Cell Death Mechanisms in Skeletal Muscle

β-淀粉样蛋白

• 批准号: 6849286
• 负责人: HENRY W QUERFURTH
• 金额: $ 27.68万
• 依托单位: STEWARD ST. ELIZABETH'S MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-15 至 2007-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6849286
• 关键词: Alphaherpesvirinae; amyloid proteins; apoptosis; cell proliferation; cellular pathology; cytotoxicity; electron microscopy; enzyme activity; enzyme linked immunosorbent assay; genetically modified animals; human tissue; immunofluorescence technique; immunoprecipitation; inclusion body; laboratory mouse; mitochondria; myositis; myotubes; polymerase chain reaction; proteasome; protein kinase; striated muscles; terminal nick end labeling; tissue /cell culture; transfection /expression vector; western blottings

DESCRIPTION (Adapted from applicant's abstract): Inclusion Body Myositis (IBM) is the most common muscle disorder in patients over 50 years of age. IBM shares several features with another age-related degenerative disorder, Alzheimer's disease (AD): 1) there are both sporadic and autosomal inherited forms, 2) local inflammatory collections are characteristic but immunosuppressive therapies are only marginally effective, and 3) accumulations of AD-related proteins are a histopathological hallmark. Congo red- reactive deposits consisting of the beta-amyloid peptide (Abeta) are the most notable feature. In contrast with the extra-cellular amyloid plaques of AD, the amyloid deposits of IBM are intracellular. Several other proteins accumulate intracellularly in the vacuolated myofibers of IBM including other epitopes of beta-amyloid precursor protein, hyperphosphorylated filaments comprised of the microtubule-associated protein tau, ubiquitin, the cellular prion protein, and cyclin dependent kinase 5 (cdk5). The mechanism of muscle cell loss in IBM remains a mystery. Abeta is known to induce programmed cell death (apoptosis) of neurons in culture and in some transgenic mouse models for Alzheimer's disease. In Aim 1, the applicants hypothesize that intracellular accumulation of Abeta in cultured skeletal muscle myotubes will induce apoptosis. Abeta deposition is provoked using an inducible promoter, a heterologous viral gene transfer system, or by direct injection. They will examine the role of the proteasome and the parkin gene in the genesis of protein accumulations. In Aim 2, Abeta is established as a myotoxins by a thorough examination of human IBM biopsy specimens, for a correlation between Abeta accumulation and several markers of apoptosis. Mouse muscle is similarly analyzed after direct injection of an Abeta-encoding adenoviral gene construct. Their 2nd hypothesis is that deposition of intracellular Abeta adversely affects Akt kinase-dependent muscle cell survival pathways and in Aim 3 we will determine if Abeta inhibits Akt activity. Furthermore, the applicants will seek evidence that Abeta induces deleterious attempts by cells to re-enter the developmental or even the cell cycle, related to Akt, p21 Cip1/Wafl or cyclin D dysfunction. Evidence for tau hyperphosphorylation from unhindered GSK-3beta activity will be sought. In Aim 4 the functional significance of Akt inhibition by Abeta is examined by asking whether Akt activation will protect muscle cells forced to overexpress Abeta from cell death. While some of the findings may be relevant to neuronal systems, they will provide insight into a novel mechanism of Abeta injury and the complex regulation of cell survival, replication and apoptosis from a key survival signal control point.

描述（改编自申请人摘要）：包涵体肌炎（IBM） 是50岁以上患者中最常见的肌肉疾病。IBM股价 另一种与年龄相关的退行性疾病阿尔茨海默氏症的几个特征 疾病（AD）：1）有散发和常染色体遗传形式，2） 局部炎性聚集是特征性的，但免疫抑制 治疗只是轻微有效，和3）AD相关的累积 蛋白质是组织病理学的标志。刚果红活性矿床 由β-淀粉样肽（Abeta）组成的蛋白质是最显著的特征。在 与AD的细胞外淀粉样斑块相比， IBM是细胞内的。其他几种蛋白质在细胞内积累， 包括β-淀粉样蛋白前体的其他表位的IBM空泡化肌纤维 蛋白质，过度磷酸化的细丝组成的微管相关的 tau蛋白、泛素、细胞朊病毒蛋白和细胞周期蛋白依赖性激酶 5（cdk5）。 IBM肌肉细胞丢失的机制仍然是一个谜。众所周知，Abeta 诱导培养物中神经元程序性细胞死亡（凋亡）， 阿尔茨海默病的转基因小鼠模型。在目标1中，申请人 假设在培养骨骼肌细胞内A β积聚 肌肉肌管将诱导细胞凋亡。Abeta沉积是由 诱导型启动子、异源病毒基因转移系统，或通过直接 注射他们将研究蛋白酶体和parkin基因在 蛋白质积累的起源。在目标2中，Abeta被确定为 通过对人IBM活检标本进行彻底检查， Abeta积累与几种凋亡标志物之间的相关性。鼠标 在直接注射编码A β的 腺病毒基因构建体。他们的第二个假设是， 细胞内Abeta不利地影响Akt激酶依赖性肌细胞存活 在Aim 3中，我们将确定Abeta是否抑制Akt活性。 此外，申请人将寻求证据，证明Abeta引起有害的 细胞试图重新进入发育甚至细胞周期， Akt、p21 Cip 1/Wafl或cyclin D功能障碍。tau的证据 将寻求来自不受阻碍的GSK-3 β活性的过度磷酸化。在Aim中 4通过询问来检验Abeta抑制Akt的功能意义。 Akt激活是否会保护被迫过度表达Abeta的肌肉细胞 细胞死亡。虽然有些发现可能与神经元 系统，他们将提供深入了解Abeta损伤的新机制， 细胞存活、复制和凋亡的复杂调控从一个关键 生存信号控制点

项目成果

Parkin reverses intracellular beta-amyloid accumulation and its negative effects on proteasome function.

Parkin 可逆转细胞内 β-淀粉样蛋白的积累及其对蛋白酶体功能的负面影响。

• DOI: 10.1002/jnr.22178
• 发表时间: 2010-01
• 期刊: JOURNAL OF NEUROSCIENCE RESEARCH
• 影响因子: 4.2
• 作者: Rosen, Kenneth M.;Moussa, Charbel E. -H.;Lee, Han-Kyu;Kumar, Pravir;Kitada, Tohru;Qin, Gangjian;Fu, Qinghao;Querfurth, Henry W.
• 通讯作者: Querfurth, Henry W.