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Cellular and Molecular Genetics of Keratoconus

圆锥角膜的细胞和分子遗传学

基本信息

批准号：
10398841
负责人：
Yutao Liu
金额：
$ 42.3万
依托单位：
AUGUSTA UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-05-01 至 2024-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10398841
关键词：
1-Phosphatidylinositol 3-Kinase Affect Affinity American Amino Acids Animal Model Apoptosis Astigmatism Bilateral Binding Blindness Cell Culture Techniques Cell Proliferation Cell physiology Cells Clinical Code Collaborations Complementary DNA Cornea Corneal Diseases Corneal Topography DNA DNA Sequence Alteration Data Data Set Diagnosis Dideoxy Chain Termination DNA Sequencing Disease Epithelial Cells Ethnic group Exons Family Female Fibroblasts Functional disorder Generations Genes Genetic Genetic Research Genetic Transcription Goals Grant Human In Vitro Individual Inherited InsP5 Investigation Keratoconus Knockout Mice Location Messenger RNA Molecular Molecular Genetics Morphology Mus Mutation Myopia Optical Coherence Tomography Outcome Pathogenesis Pathogenicity Pathologic Pathology Pathway interactions Patients Pattern Phenotype Phosphatidylinositol Phosphates Phosphatidylinositols Phosphoric Monoester Hydrolases Phosphorylation Phosphotransferases Prevalence Proteins Proto-Oncogene Proteins c-akt Reporting Role Sampling Site-Directed Mutagenesis Stromal Cells Testing Thinness Time Tissues Transforming Growth Factor beta Validation Variant Vision Screening base cell motility corneal epithelium corneal scar diphosphoinositol pentakisphosphate kinase exome sequencing improved in vivo in vivo Model inositol heptakisphosphate lymphoblast male mouse model novel overexpression phosphatidylinositol 3,4,5-triphosphate prevent protein function response therapy development transcriptome sequencing translational impact

项目摘要

ABSTRACT Our long term goal is to identify and characterize genetic mutations involved in the pathogenesis of keratoconus (KC). KC is a bilateral, asymmetric corneal degeneration characterized by localized thinning and protrusion of the thinned cornea. KC leads to high myopia, irregular astigmatism, and cornea scarring. Although genetic factors contribute to KC pathogenesis, its genetic causes remain to be identified. Only mutations in the VSX1 and MIR184 genes are known to cause KC, but they account for <10% KC cases. KC is typically inherited through autosomal dominant patterns, though autosomal recessive patterns have been reported. It affects males and females similarly and is detected in all ethnic groups worldwide. Our productive collaborations with others amassing DNA samples from more than 600 KC individuals and their families have led to the identification of KC-segregating mutations in three genes, including PPIP5K2 (diphosphoinositol pentakisphosphate kinase 2). PPIP5K2 encodes a bifunctional kinase and phosphatase with high affinity to InsP5 / 5-InsP7 and PtdIns(3,4,5)P3 respectively. In two multi-generation families with multiple affected individuals, we have identified two heterozygous mutations affecting amino acids located in the polyphosphoinositide binding domain (PBD) of PPIP5K2. PPIP5K2 is highly expressed in human and mouse cornea tissue. The PPIP5K2-related phosphoinositide-3-kinase (PI-3 kinase) pathway, when inhibited, affects AKT phosphorylation and keratocyte survival, leading to the apoptosis of corneal stromal keratocytes in KC patients. We hypothesize that PPIP5K2 mutations alter TGFβ/AKT pathways, leading to degeneration of corneal epithelial and stromal cells with subsequent thinning/bulging of the affected cornea. We will determine how the identified mutations affect the cellular function of PPIP5K2 in vitro using primary human epithelial and stromal cells in Aim 1. We will determine the KC-related corneal phenotypes in Ppip5k2-knockout mice using comprehensive approaches including optical coherence tomography, functional vision screening, and slit lamp exams followed by morphological examinations in Aim 2. On the other hand, we will screen PPIP5K2 mutations in additional familial and sporadic patients using whole exome sequencing. PPIP5K2-negative multiplex families will be further examined with whole exome sequencing to identify novel mutations in Aim 3. Upon successful completion, we will have a validated animal model of KC and potential novel targets for future research directed at KC diagnosis and clinical therapy.

摘要