Analysis Of FGF Receptor Signalling Involved In Lens Cell Proliferation And Differentiation
Funder
National Health and Medical Research Council
Funding Amount
$343,028.00
Summary
Cataract, the loss of transparency of the eye lens, is the leading cause of blindness in the world. An eventual cure for cataract depends on a better understanding of the basic molecular processes in the normal and cataractous lens. Our research has focussed on identifying the molecules that control the formation and maintenance of the lens. Growth factors are important regulators of cell behaviour and our studies have provided compelling evidence that members of the FGF growth factor family pla ....Cataract, the loss of transparency of the eye lens, is the leading cause of blindness in the world. An eventual cure for cataract depends on a better understanding of the basic molecular processes in the normal and cataractous lens. Our research has focussed on identifying the molecules that control the formation and maintenance of the lens. Growth factors are important regulators of cell behaviour and our studies have provided compelling evidence that members of the FGF growth factor family play pivotal roles in lens developmental biology by influencing lens cell proliferation and differentiation. An important finding from our laboratory is that FGF induces lens epithelial cell proliferation and differentiation at different concentrations. The FGFs elicit intracellular responses upon binding to and activating cell surface FGF receptors (FGFRs). The FGFRs are membrane bound tyrosine kinases which upon activation, activate specific signalling pathways leading to a specific cellular response. To understand how FGFs mediate and regulate different responses in lens cells, namely cell proliferation and fibre differentiation, we plan to examine the role of FGFRs in normal lens development using genetically altered FGFRs that will be expressed specifically in lenses of transgenic mice. While it is known that four different FGF receptor genes are expressed by the normal developing lens, it is unknown what role each of these play in the process of lens cell proliferation and differentiation. In addition, as we can reproduce a specific FGF-induced lens cellular response in vitro, we will use our lens explant culture system to dissect the signalling pathway(s) downstream from specific receptor activation and correlate this with a specific cellular response. By identifying the molecules and mechanisms that control the cellular processes essential for normal lens development, we can better understand how disruptions of these processes lead to cataract formation.Read moreRead less
Growth-factor Induced Signalling Pathways Involved In The Regulation Of Lens Cell Behaviour
Funder
National Health and Medical Research Council
Funding Amount
$253,500.00
Summary
Cataract, the loss of transparency of the eye lens, is a major cause of blindness in the world. A cure for cataract depends on a better understanding of the molecular processes in the normal and cataractous lens. Lens growth is regulated by controlled proliferation of epithelial cells and their precise localised differentiation into fibres. As disruption of this tight regulation leads to cataract, identifying the molecules that control cell proliferation and differentiation may provide insights ....Cataract, the loss of transparency of the eye lens, is a major cause of blindness in the world. A cure for cataract depends on a better understanding of the molecular processes in the normal and cataractous lens. Lens growth is regulated by controlled proliferation of epithelial cells and their precise localised differentiation into fibres. As disruption of this tight regulation leads to cataract, identifying the molecules that control cell proliferation and differentiation may provide insights into the mechanisms involved in cataract formation. Following cataract surgery, for example, a number of patients develop aftercataract which results from the response of lens cells remaining after surgery. These residual cells, unlike those tightly regulated in the normal lens, begin to divide and differentiate in an attempt to form a new lens. The main aim of this study is to understand what regulates the proliferation and differentiation of lens cells. Growth factors are key regulators of cell behaviour and our studies provide evidence that members of the FGF, PDGF and IGF growth factor families play pivotal roles in the lens by influencing cell proliferation and differentiation. Growth factors stimulate cellular processes by activating specific cell surface receptors. Once activated, these receptors switch on specific intracellular signalling pathways leading to a specific cellular response. To understand how different growth factors mediate and regulate lens cell proliferation and fibre differentiation, we plan to examine the role of FGF-, PDGF- and IGF-induced signalling in normal lens biology. To do this, we will use a well established lens explant culture system to dissect the signalling pathway(s) downstream of specific receptor activation and correlate this with a specific cellular response. By understanding the cellular processes essential for normal lens development, we can better understand how disruptions of these processes lead to cataract formation.Read moreRead less
Roles For MAPK-ERK1-2, -catenin-TCF And Smad3 Mediated Signalling Pathways In TGF -induced Cataract
Funder
National Health and Medical Research Council
Funding Amount
$339,071.00
Summary
Posterior capsular opacification (PCO) is a common and costly complication of cataract surgery that is caused by aberrant growth of lens cells. The TGF growth factor family causes PCO. TGF activates three signalling pathways in the lens, MAPK-ERK1-2, -catenin-TCF and Smad3; however currently we do not know which one induces PCO. This project will identify the pathway(s) that prevent TGF from causing cataracts. This is critical for the development of pharmaceuticals to prevent PCO.
Studies Of Antigen Presenting Cells In The Anterior Segment Of The Eye And Their Role In Immune-mediated Ocular Disease
Funder
National Health and Medical Research Council
Funding Amount
$241,018.00
Summary
Dendritic cells (DC) are considered the 'sentinels' of the immune system because they are capable of trapping antigenic material derived from invading organisms such as bacteria and viruses in peripheral tissues-organs (skin, gut, respiratory tract etc) and then transporting these antigens to the lymphoid organs where they 'alert' the immune system to potential 'dangers' and elicit appropriate T cell responses. If the antigens are novel this mechanism forms the basis of primary cell-mediated imm ....Dendritic cells (DC) are considered the 'sentinels' of the immune system because they are capable of trapping antigenic material derived from invading organisms such as bacteria and viruses in peripheral tissues-organs (skin, gut, respiratory tract etc) and then transporting these antigens to the lymphoid organs where they 'alert' the immune system to potential 'dangers' and elicit appropriate T cell responses. If the antigens are novel this mechanism forms the basis of primary cell-mediated immune responses. Previously 'educated' T cells may upon contact with antigens in the periphery (when presented by other antigen presenting cells [APCs], such as macrophages) become activated. This forms the basis for secondary immune responses. Immune and inflammatory responses in the eye are held in check to avoid permanent damage to the delicate tissues and maintain visual function. The mechanisms which regulate immunological responses in the eye are only now becoming clear. Studies in the Chief Investigators laboratory over the last 7 years have been aimed at unravelling the life cycle and function of APCs in the eye. The present study has three specific aims: 1) Determining whether DC in the eye once they have taken up antigens migrate to the spleen or local lymph nodes? 2) The second aim of this project is to use an animal model of uveitis and transfer fluorescent labelled donor T cells to study the events in the living eye which lead to autoimmune uveoretinitis. In particular we wish to identify the cells that present antigen to infiltrating lymphocytes. 3) Patients often develop posterior uveitis (an autoimmune condition) after a cold or bacterial infection. We aim to mimic conditions of acute inflammation in the eye to see whether this may secondarily predispose the eye to attack by autoreactive lymphocytes.Read moreRead less