The Cellular Control of Corneal Development and Transparency and Generation of Biomimetic Corneal Tissue.

角膜发育和透明度的细胞控制以及仿生角膜组织的生成。

• 批准号: BB/M025349/1
• 负责人: Andrew Quantock
• 金额: $ 98.09万
• 依托单位: CARDIFF UNIVERSITY
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2015
• 资助国家: 英国
• 起止时间: 2015 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FM025349%2F1
• 关键词: Cellular; Control; Corneal; Development; Transparency

The cornea is the clear tissue at the front of the eye, which transmits light and focuses it sharply onto the retina. Accordingly, it is absolutely essential for vision. Composed mostly of collagen, the cornea is not unlike other collagen-rich tissues, such as tendons, cartilages, intervertebral discs, or even the sclera; the "white of the eye". But what makes the cornea optically clear is the exquisite way in which the collagen is structured.Collagen in the human body exists predominantly in the form of long fibres, which are very strong along their axes, and can be thought of as having mechanical properties rather like ropes on sailing ships or steel cables on suspension bridges. The organisation of collagen fibres in different tissues is contingent on the tissue's function, and the predominant requirement is usually mechanical. The cornea is unique in this regard because as well as the need to fulfil mechanical requirements, it needs to be transparent.The bulk of the cornea is made up of cells, known as keratocytes, and collagen. Most collagen exists in the form of very long and very thin fibres, or fibrils as they are called in the cornea because they are so thin. Remarkably, and unlike all the other collagen-rich tissues in the body, collagen fibrils in cornea are all of exactly the same diameter and are arranged into a near-perfect, hexagonal-type lattice. It is this precise structural arrangement of collagen which gives the cornea its transparency. But, how does it arise?Keratocytes in the cornea synthesise and deposit collagen. So, presumably these cells must be at least partly responsible for the way in which the collagen fibrils are laid down and arranged. We will use pioneering microscopic approaches across a wide range of magnifications, using laser and electron imaging technologies and working with scientists in the University of California, to study corneas from developing chicks in fertilised hen eggs. Our aim is to understand precisely how cells in the developing cornea interact with each other to make such a beautifully structured tissue as a transparent cornea (the basis of corneal transparency in the chick is the same as that in humans). Recently, we pioneered the use of three-dimensional volume electron microscopy for the study of cornea, and discovered that cells in the developing chick cornea all have highly extended, but thin, cell processes. This showed that the cells themselves occupy a volume of the cornea which is much larger than previously believed. Based on this discovery, our hypothesis is that cells in the developing cornea form an extended network in which they communicate with each other, and that, as a group, they have the innate ability to synthesise incredibly thin collagen fibrils and deposit them into a precise lattice-like arrangement to meet the needs of transparency. To test this hypothesis we will study corneas from the very earliest stages of development, which have never before been examined in three dimensions at such high magnifications. New methodologies for the mathematical modelling of corneal light transmission will be applied to this data to ascertain the key structural requirements for corneal transparency. We will also investigate the cellular contribution to corneal transparency, both by mathematical modelling and by direct measurement of light scattering.Finally, we will interfere with cell-communication pathways in corneal keratocytes, extracted from developing chick corneas and grown in the lab, to pinpoint what molecular mechanisms they use to communicate. These experiments and analyses, using a new way of growing cells in a three-dimensional environment, which we successfully developed to encourage tendon cells to synthesise aligned collagen fibres, will provide great insights for the field of corneal tissue engineering to help inform the intelligent design of the next generation of bioengineered corneal constructs.

角膜是眼前的透明组织，它会传递光线并将其急切地聚焦到视网膜上。因此，这对于视觉绝对是必不可少的。角膜主要由胶原蛋白组成，与其他富含胶原蛋白的组织，例如肌腱，软骨，椎间盘甚至巩膜不同。 “眼睛的白色”。但是，使角膜在光学上清除的是胶原蛋白结构的精美方法。人体中的胶原蛋白主要以长纤维的形式存在，它们沿轴沿其轴非常强，并且可以认为是具有机械性能，就像在悬架上具有帆船或钢电缆上的绳索一样。不同组织中胶原蛋白纤维的组织取决于组织的功能，并且主要的要求通常是机械的。角膜在这方面是独一无二的，因为以及满足机械需求的需求，它需要透明。大部分角膜是由细胞组成的，被称​​为角膜细胞和胶原蛋白。大多数胶原蛋白以非常长且非常薄的纤维形式存在，或者是在角膜中称为纤维的原纤维，因为它们是如此薄。值得注意的是，与体内所有其他富含胶原蛋白的组织不同，角膜中的胶原蛋白原纤维的直径完全相同，并排列成近乎完美的六边形型晶格。正是这种胶原蛋白的精确结构排列使角膜透明。但是，它是如何产生的？角膜合成和沉积胶原蛋白的角膜细胞。因此，大概这些细胞至少必须部分负责胶原蛋白原纤维的放置和排列的方式。我们将使用激光和电子成像技术并与加利福尼亚大学的科学家合作，在广泛的宏伟速度中使用开创性的显微镜方法研究，从受精卵中发育的小鸡中研究角膜。我们的目的是精确地了解发育中的角膜中的细胞如何相互相互作用，以使结构精美的组织像透明的角膜（雏鸡角膜透明度的基础与人类中的角膜透明度相同）。最近，我们开创了使用三维体积电子显微镜进行角膜研究的开创性，并发现发育中的鸡角膜中的细胞都具有高度扩展但薄的细胞过程。这表明细胞本身占据了一定数量的角膜，这比以前认为的要大得多。基于这一发现，我们的假设是，发育中的角膜中的细胞形成了一个扩展的网络，它们相互通信，并且作为一个群体，它们具有固有的能力，可以合成令人难以置信的薄胶原纤维纤维，并将它们沉积到精确的晶格样排列中，以满足透明度的需求。为了检验这一假设，我们将从最早的发育阶段研究角膜，在这种高宏伟的情况下，这些阶段从未在三个维度上进行过研究。角膜光传输的数学建模的新方法将应用于此数据，以确定角膜透明度的关键结构要求。我们还将通过数学建模和直接测量光散射来研究细胞对角膜透明度的贡献。从本文中，我们将干扰角膜角化细胞中的细胞通信途径，从发育中的雏鸡角膜中提取并在实验室中生长，以指出它们用于传达的分子机制。这些实验和分析使用一种在三维环境中生长细胞的新方法，我们成功地开发了肌腱细胞综合对齐的胶原蛋白纤维，将为角膜组织工程领域提供很好的见解，以帮助告知下一代生物连接的角膜结构的智能设计。

项目成果

A Surgical Cryoprobe for Targeted Transcorneal Freezing and Endothelial Cell Removal.

• DOI: 10.1155/2017/5614089
• 发表时间: 2017
• 期刊: Journal of ophthalmology
• 影响因子: 1.9
• 作者: Akhbanbetova A;Nakano S;Littlechild SL;Young RD;Zvirgzdina M;Fullwood NJ;Weston I;Weston P;Kinoshita S;Okumura N;Koizumi N;Quantock AJ
• 通讯作者: Quantock AJ

CD200 facilitates the isolation of corneal epithelial cells derived from human pluripotent stem cells.

• DOI: 10.1038/s41598-018-34845-2
• 发表时间: 2018-11-08
• 期刊: Scientific reports
• 影响因子: 4.6
• 作者: Hayashi R;Ishikawa Y;Katayama T;Quantock AJ;Nishida K
• 通讯作者: Nishida K

Fabrication of a Corneal Epithelial Cell Sheet from Human Pluripotent Stem Cells by a Method Based on Spontaneous Ocular Cell Differentiation

基于眼细胞自发分化的方法从人多能干细胞制备角膜上皮细胞片

• DOI: 10.1038/protex.2016.009
• 发表时间: 2016
• 期刊: Protocol Exchange
• 作者: Hayashi R

Chondroitin Sulphate/Dermatan Sulphate Proteoglycans: Potential Regulators of Corneal Stem/Progenitor Cell Phenotype In Vitro.

• DOI: 10.3390/ijms24032095
• 发表时间: 2023-01-20
• 期刊: INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
• 影响因子: 5.6
• 作者: Bains, Kiranjit K.;Ashworth, Sean;Koudouna, Elena;Young, Robert D.;Hughes, Clare E.;Quantock, Andrew J.
• 通讯作者: Quantock, Andrew J.