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Role of Aquaporin-0 for cell-to-cell adhesion and lens transparency

Aquaporin-0 在细胞间粘附和晶状体透明度方面的作用

基本信息

批准号：
8494216
负责人：
Kulandaiappan Varadaraj
金额：
$ 7.5万
依托单位：
STATE UNIVERSITY NEW YORK STONY BROOK
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-04-01 至 2014-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8494216
关键词：
Accounting Adhesions Aging-Related Process Amino Acids Animal Model Architecture Binding Biochemical Biological Blinded Blindness Calmodulin Cataract Categories Cell Adhesion Cell Adhesion Molecules Cell Aging Cells Charge Chimera organism Cleaved cell Computers Data Development Disease Drug Compounding Engineering Goals Homeostasis Human In Vitro Integral Membrane Protein Investigation Knock-in Mouse Knock-out Knockout Mice L Cells Lens Fiber Literature MIP gene Methods Missense Mutation Modeling Molecular Mus Mutagenesis Mutate Mutation Outcome Permeability Play Prevention Proteins Role Senile Cataract Site Site-Directed Mutagenesis Structural Protein Structure Testing Therapeutic Tissues Transgenic Organisms Tyrosine United States Vision Water Xenopus oocyte age related base cell age cytotoxicity design extracellular falls fiber cell improved in vivo insight lens lens transparency monomer mouse model mutant novel promoter protein expression protein misfolding public health relevance research study restoration simulation water channel

项目摘要

DESCRIPTION (provided by applicant): Lens is a transparent tissue that lacks vasculature. Transmembrane water channels known as aquaporins (AQPs) play a significant role in maintaining transparency and homeostasis in the avascular lens. Mutations in AQP0 result in lens cataract in both human and mouse; knockout leads to cataract in mouse. Our long term goal is to contribute to the treatment and prevention of lens cataract. In this proposal, we are directing our focus on AQP0. At least two functions have been attributed for AQP0 viz., water permeability and cell-to-cell adhesion. Water permeability has been proven authentically through in vitro and in vivo studies while cell-to-cell adhesion function remains hypothetical; moreover, it is controversial whether intact as well as cleaved forms of AQP0 function both as a water pore and a cell-to-cell adhesion protein. The goals of this proposal is to critically experiment and clearly define whether AQP0 functions as a cell-to-cell adhesion protein, whether intact as well as the N- or and C- terminus cleaved forms function both as a water pore and a cell-to-cell adhesion protein (Aim 1), whether the extracellular loops play a critical role in cell-to-cell adhesion (Aim 2), whether the calmodulin-binding domain has a role with regard to adhesion function (Aim 3) and whether the function/s of AQP0 can be replaced by knocking in AQP4 which is proven to have both water permeability and cell-to-cell adhesion function (Aim 4). A novel method developed will be used to study the cell-to-cell adhesion function of the different forms of AQP0. Involvement of extracellular loop in cell-to-cell adhesion and the role of calmodulin binding domain for the functions of AQP0 will be studied using site-directed mutagenesis and PCR-based domain swapping. Computer based molecular simulation will be performed as necessary for mutagenesis studies. Knock-in animal models will be developed to test the in vivo outcome of the in vitro findings. The objectives will be pursued using structure-function approach and performing cytological, biochemical and molecular biological experiments as appropriate to verify the results. PUBLIC HEALTH RELEVANCE: Lens cataract is responsible for majority of the loss of sight in the United States and ranks #1 globally with over 20 million people around the world already blinded and an additional 1.25 million added to the total each year; age-related cataract by itself accounts for more than 48% of loss of vision scenarios. Lens cataract caused by AQP0 falls in the category of conformational diseases (proteopathies) as they are mainly caused by missense mutations or age related protein misfolding, aggregation and cytotoxicity and main goal of this project is to provide new insights into the structure-related functional roles of AQP0, the most abundant integral membrane protein in the lens, for maintaining transparency and homeostasis. This investigation will contribute to an improved understanding of normal lens development and aging processes, and help to design and develop therapeutic compounds/drugs for congenital and senile cataracts in humans.

描述（由申请人提供）：晶状体是一种透明组织，缺乏脉管系统。被称为水通道蛋白（AQPs）的跨膜水通道在维持无血管晶状体的透明度和稳态中起着重要作用。AQP0突变导致人和小鼠晶状体白内障；基因敲除导致小鼠白内障。我们的长期目标是为治疗和预防晶状体白内障做出贡献。在本提案中，我们将重点放在AQP0上。至少有两个功能归因于AQP0，即水渗透性和细胞间粘附。通过体外和体内研究证实了水渗透性，而细胞间的粘附功能仍然是假设的；此外，完整形式的AQP0和断裂形式的AQP0是否同时作为水孔和细胞间粘附蛋白存在争议。本提案的目标是批判性地实验并明确定义AQP0是否作为细胞间粘附蛋白，是否完整以及N-或和C-端劈裂形式既作为水孔又作为细胞间粘附蛋白（Aim 1），细胞外环是否在细胞间粘附中起关键作用（Aim 2）。钙调素结合域是否对粘附功能有作用（Aim 3）， AQP0的功能是否可以被敲除AQP4， AQP4已被证明具有透水性和细胞间粘附功能（Aim 4）。一种新的方法将被用于研究不同形式AQP0的细胞间粘附功能。细胞外环参与细胞间粘附以及钙调素结合域在AQP0功能中的作用将通过位点定向诱变和基于pcr的结构域交换进行研究。基于计算机的分子模拟将作为诱变研究的必要手段。将开发敲入动物模型来测试体外研究结果的体内结果。目标将采用结构-功能方法和执行细胞学，生化和分子生物学实验来验证结果。

项目成果

期刊论文数量（11）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Intact and N- or C-terminal end truncated AQP0 function as open water channels and cell-to-cell adhesion proteins: end truncation could be a prelude for adjusting the refractive index of the lens to prevent spherical aberration.

DOI：
10.1016/j.bbagen.2014.05.002
发表时间：
2014-09
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA-GENERAL SUBJECTS
影响因子：
3
作者：
Kumari, S. Sindhu;Varadaraj, Kulandaiappan
通讯作者：
Varadaraj, Kulandaiappan

Deletion of beaded filament proteins or the C-terminal end of Aquaporin 0 causes analogous abnormal distortion aberrations in mouse lens.

DOI：
10.1016/j.exer.2021.108645
发表时间：
2021-08
期刊：
EXPERIMENTAL EYE RESEARCH
影响因子：
3.4
作者：
Varadaraj, Kulandaiappan;FitzGerald, Paul G.;Kumari, S. Sindhu
通讯作者：
Kumari, S. Sindhu

Positively charged amino acid residues in the extracellular loops A and C of lens aquaporin 0 interact with the negative charges in the plasma membrane to facilitate cell-to-cell adhesion.

晶状体水通道蛋白 0 的细胞外环 A 和 C 中带正电荷的氨基酸残基与质膜中的负电荷相互作用，以促进细胞间粘附。

DOI：
10.1016/j.exer.2019.05.022
发表时间：
2019
期刊：
Experimental eye research
影响因子：
3.4
作者：
Kumari,Sindhu;Taginik,Gozde;Varadaraj,Sangeeth;Varadaraj,Kulandaiappan
通讯作者：
Varadaraj,Kulandaiappan

Functional characterization of an AQP0 missense mutation, R33C, that causes dominant congenital lens cataract, reveals impaired cell-to-cell adhesion.

DOI：
10.1016/j.exer.2013.09.019
发表时间：
2013-11
期刊：
EXPERIMENTAL EYE RESEARCH
影响因子：
3.4
作者：
Kumari, Sindhu S.;Gandhi, Jason;Mustehsan, Mohammed H.;Eren, Semih;Varadaraj, Kulandaiappan
通讯作者：
Varadaraj, Kulandaiappan

Aquaporin 0 plays a pivotal role in refractive index gradient development in mammalian eye lens to prevent spherical aberration.