Biological significance of Mallory-Denk bodies in mouse and human liver diseases

Mallory-Denk 小体在小鼠和人类肝脏疾病中的生物学意义

• 批准号: 8201643
• 负责人: Amika Singla
• 金额: $ 4.63万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2012-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8201643
• 关键词: Abbreviations; Address; Alanine Transaminase; Alcoholic Liver Diseases; Alcohols; Alkaline Phosphatase; Animals; Area; Aspartate Transaminase; Backcrossings; Biochemical; Biological; Cells; Chronic; Cirrhosis; Clinical; Code; Copper; Cytoplasmic Inclusion; Deposition; Diet; Disease; Disease Association; Disease Progression; Environment; Enzymes; Epithelial; Epithelial Cells; Epithelium; Erythropoietic Protoporphyria; Fatty acid glycerol esters; Female; Gender; Gene Mutation; Generations; Genes; Genetic; Genetic Predisposition to Disease; Genetic Programming; Genomics; Griseofulvin; Hematoxylin and Eosin Staining Method; Heme; Hepatocyte; Human; Inbred BALB C Mice; Individual; Intermediate Filament Proteins; Intermediate Filaments; K-18 conjugate; KRT19 gene; Keratin; Laboratories; Laboratory Study; Lead; Liver; Liver diseases; Mallory Body; Mediating; Mentors; Metabolic Diseases; Modeling; Molecular; Molecular Analysis; Molecular Profiling; Mus; Mutation; Myopathy; Neuropathy; Patients; Pharmaceutical Preparations; Point Mutation; Polyacrylamide Gel Electrophoresis; Porphyrins; Predisposition; Primary carcinoma of the liver cells; Proteins; Protoporphyrins; Regulation; Resolution; Sex Characteristics; Sodium Dodecyl Sulfate; Steatohepatitis; Susceptibility Gene; Technology; Testing; Therapeutic; Tissue Polypeptide Specific Antigen; Transglutaminases; Ubiquitin; Woman; alcohol exposure; clinically significant; crosslink; disease diagnosis; feeding; ferrochelatase; gel electrophoresis; insight; laser capture microdissection; male; men; mouse model; non-alcoholic; nonalcoholic steatohepatitis; novel; overexpression; polypeptide; problem drinker; response; transglutaminase 2; two-dimensional

DESCRIPTION (provided by applicant): Mallory Denk Bodies (MDBs) are hepatocyte cytoplasmic inclusions that serve as histological hallmark in patients with steatohepatitis (alcoholic and nonalcoholic), but can also be found in other liver disorders including hepatocellular carcinoma and copper metabolism disorders. Recent evidence suggests that the presence of MDBs associates with accelerated liver disease progression. The major constituents of MDBs are the cytoskeletal intermediate filament (IF) proteins, keratin polypeptides 8 and 18 (K8/K18), which form obligate non-covalent K8 and K18 heterodimers that coalesce as tetramers and higher order oligomers. MDB formation is induced by feeding mice with porphyrinogenic drugs, and requires the preferential overexpression of K8 (to establish a K8>K18 state) and K8 crosslinking by transglutaminase. Spontaneous MDBs have been described in mice with a point mutation in the ferrochelatase gene (fch/fch mice), which develop erythropoietic protoporphyria (EPP) due to protoporphyrin deposition in the liver. Also, male mice in one tested strain are more predisposed to MDB accumulation as compared with female mice. The central hypothesis that will be tested in this proposal is that porphyrin deposition, chronic alcohol exposure and genetic gender-associated differences create an environment that promotes MDB formation, and that MDB formation contributes to the hepatocyte ultimate cell fate. The topic covered by this proposal is a novel and understudied area given that the biological significance of MDB formation, and whether MDBs are beneficial or detrimental to hepatocytes, is still not clear despite being first described nearly 100 years ago by Dr. Frank Mallory. Our hypothesis will be tested utilizing three specific aims: (i) Characterize the genetic susceptibility and mechanism of MDB formation in a mouse model of EPP that carries a ferrochelatase gene mutation, (ii) Develop a mouse MDB alcohol model, (iii) Characterize the cell fate of MDB-containing hepatocytes in mouse and human livers. The proposed study combines molecular and biochemical approaches, and state-of-the-art technologies and includes mouse MDB models, as well as human liver MDB molecular analysis. Fundamental findings that we hope to establish include the generation of an alcohol mouse MDB model that is hitherto lacking, the identification of potential gender association with MDB formation in alcoholic liver disease and EPP models, and determining the consequences of MDB formation in individual hepatocytes. Findings from the proposed studies will help clarify whether the pharmacological manipulation of MDBs might be helpful in the treatment of liver diseases. We anticipate that our findings will also contribute to the understanding of other inclusion-associated extra-hepatic disorders, such as myopathies and neuropathies that harbor cytoplasmic IF- containing inclusions. PUBLIC HEALTH RELEVANCE: Patients with a variety of cirrhosis-causing liver diseases develop insoluble deposits in liver cells, termed Mallory-Denk Bodies (MDBs) that clinicians use to help them establish a liver disease diagnosis. The significance of MDBs is poorly understood, but agents that promote their resolution or formation may provide a therapeutic benefit. My proposal will develop mouse models to study MDB formation, and should help us understand in human and mouse livers whether MDBs are protective or detrimental to liver cells.

描述（由申请人提供）：Mallory Denk身体（MDB）是肝细胞胞质胞质内包含物，在脂肪性肝炎患者（酒精和非酒精性）患者中是组织学标志，但也可以在其他肝疾病中发现，包括肝细胞癌癌和铜质癌和铜质化代表代理症。最近的证据表明，MDBS的存在与加速肝脏疾病进展。 MDB的主要成分是细胞骨架中间丝（IF）蛋白，角蛋白多肽8和18（K8/K18），它们形成了强有力的非共价K8和K18异二聚体，将其融合为四聚体和高阶寡聚物。 MDB的形成是通过用卟啉原性药物喂养小鼠的，并且需要对K8（建立K8> K18态）和通过转谷氨酰胺酶进行交联的K8交联。已经在铁胆道酶基因（FCH/FCH小鼠）中具有点突变的小鼠中描述了自发的MDB，这些小鼠由于肝脏中的原核蛋白沉积而形成了红细胞原生质核（EPP）。同样，与雌性小鼠相比，一种测试菌株中的雄性小鼠更容易受到MDB的积累。 该提案中将测试的中心假设是卟啉沉积，慢性酒精暴露和与遗传性别相关的差异创造了一种促进MDB形成的环境，并且MDB的形成有助于肝细胞最终细胞的细胞燃料。该提案所涵盖的主题是一个新颖而研究的领域，因为MDB形成的生物学意义以及MDB是有益还是对肝细胞有益或有害，尽管弗兰克·马洛里（Frank Mallory）博士在大约100年前首先描述了MDB。我们的假设将利用三个具体目的对我们的假设进行检验：（i）在带有铁胆管酶基因突变的小鼠模型中表征MDB形成的遗传敏感性和机制，（ii）开发了小鼠MDB酒精模型，（III）表征了伴有MDB Hepatocotocytes in Mouse and Munse and Mully and Munse and Munse and Munse and Munse and Munse and Munse and Munse and Munse and Munse and Munse and Munse and Munse and Munse and Munse and Munse and Munse and Munse and Munse and Munse and Humers。 提出的研究结合了分子和生化方法以及最先进的技术，包括小鼠MDB模型以及人肝MDB分子分析。我们希望确定的基本发现包括迄今为止缺乏的酒精小鼠MDB模型，在酒精性肝病和EPP模型中鉴定了潜在的性别关联与MDB形成的鉴定，并确定MDB形成在单个肝细胞中的后果。拟议研究的发现将有助于阐明MDB的药理学操纵是否可能有助于治疗肝脏疾病。我们预计我们的发现也将有助于理解其他与包容性的外肝外疾病，例如含有含有细胞质的If-含有夹杂物的肌病和神经病。 公共卫生相关性：各种引起肝硬化的肝病的患者在肝细胞中出现不溶性沉积物，称为Mallory-denk体（MDBS），临床医生用来帮助他们建立肝病诊断。 MDB的意义知之甚少，但是促进其解决方案或形成的代理可能会带来治疗益处。我的建议将开发小鼠模型来研究MDB的形成，并应帮助我们在人类和小鼠肝脏中了解MDB是否对肝细胞有害或有害。