Function Of Factor H-related Protein-5, A Novel Human Plasma Complement Protein Found In Glomerular Immune Deposits
Funder
National Health and Medical Research Council
Funding Amount
$186,430.00
Summary
The Investigators have recently discovered a new protein which is present in human blood and is also seen in the diseased kidneys of patients with nephritis. The new protein is present in all types of nephritis that are caused by antibodies together with another part of the immune system, called the complement system, which is know to have an important role in causing tissue damage in immune diseases. The new protein is a part of the complement system but its exact function is not yet known. The ....The Investigators have recently discovered a new protein which is present in human blood and is also seen in the diseased kidneys of patients with nephritis. The new protein is present in all types of nephritis that are caused by antibodies together with another part of the immune system, called the complement system, which is know to have an important role in causing tissue damage in immune diseases. The new protein is a part of the complement system but its exact function is not yet known. The protein is likely to be important in immune diseases because it is so commonly found in diseased kidneys and other organs with complement-associated disease. In this project we will conduct a series of experiments which will determine how the new protein works in the complement system and also how important the protein is in causing kidney damage in nephritis. Nephritis is the commonest cause of kidney failure in Australia and research directed towards the mechanism of kidney damage has the potential to produce new types of therapy. The complement system also has a major role in other inflammatory diseases and in body defense systems (such as protection against microbial attack). The complement system must be able to distinguish between foreign particles and the body's own tissue and this new protein may have a role in the appropriate regulation of complement to attack the right things in the body. Elucidation of the function of this protein may well assist, therefore, in developing therapies for a variety of inflammatory diseases and infectious diseases, in addition to nephritis.Read moreRead less
Role Of Complement Factor H And Related Proteins In Regulating Complement Activation And Microbial Pathogenesis
Funder
National Health and Medical Research Council
Funding Amount
$377,036.00
Summary
A group of proteins in blood called Complement are activated in the presence of foreign cells or organisms and this generally results in their destruction. It is important to direct this destructive activity against foreign and not self tissue. This is achieved by a further family of proteins, including factor H, which regulate complement activity and how these proteins work is the principal focus of this project. There are many diseases in which damage results from inadvertent complement damage ....A group of proteins in blood called Complement are activated in the presence of foreign cells or organisms and this generally results in their destruction. It is important to direct this destructive activity against foreign and not self tissue. This is achieved by a further family of proteins, including factor H, which regulate complement activity and how these proteins work is the principal focus of this project. There are many diseases in which damage results from inadvertent complement damage and the regulatory proteins have therapeutic potential in this area. In addition many bacteria and other microorganisms, which should be destroyed by complement, escape by binding regulatory proteins. Understanding how this is achieved may reveal new targets for vaccine development. Knowledge of how the production of factor H and related proteins will help understand how inflammation occurs and how it might be controlled.Read moreRead less
Brain And Skin Blood Flow: New Animal Model For Understanding Psychiatric Disorders And Evaluating Psychotropic Agents
Funder
National Health and Medical Research Council
Funding Amount
$874,840.00
Summary
We suddenly become pale when we get a fright; cutaneous blood vessels are linked to psychological function. The skin vessel constriction response occurs because special neurochemical pathways in the brain send messages to the spinal cord, and from there messages traverse peripheral sympathetic nerves to constrict the blood vessels in the skin. By measuring skin blood flow in the rabbit ear and the rat tail we have been able to discover the major brain pathway by which the constrict-the-skin-bloo ....We suddenly become pale when we get a fright; cutaneous blood vessels are linked to psychological function. The skin vessel constriction response occurs because special neurochemical pathways in the brain send messages to the spinal cord, and from there messages traverse peripheral sympathetic nerves to constrict the blood vessels in the skin. By measuring skin blood flow in the rabbit ear and the rat tail we have been able to discover the major brain pathway by which the constrict-the-skin-blood-vessels message reaches the spinal cord. The pathway involves the amygdala, a forebrain region important in emotional expression and the raphe nuclei in the medulla oblongata. Drugs which affect psychological function also effect skin blood flow. Ecstasy, the street drug used to induce euphoria also constricts the skin vessels, and, sadly, the body temperature may increase so much that death ensues. Ecstasy vigorously constricts the skin blood vessels in rabbits, and temperature increases. Ecstasy is thought to act on serotonin-containing nerve cells in the brain, releasing serotonin (5-HT) onto special 5-HT2A receptors. Activation of these receptors affects both psychological function and skin blood flow. Modern drugs used to treat schizophrenia, so called atypical antipsychotics like clozapine and olanzapine, are thought to act as antagonists at 5-HT2A receptors in the brain. We were thus very excited when we discovered in our rabbit model that clozapine reverses the skin vasoconstriction induced by ecstasy. This means that we have specific hypotheses concerning the actual brain pathways and neurotransmitters whereby ecstasy and clozapine exert their effects on skin blood flow. Elucidating these pathways in rabbits and rats will provide solid knowledge concerning the mechanism of action of the atypical antipsychotics, and it may well prove possible to use our animal model to predict whether proposed new antipsychotic agents will be therapeutically effective.Read moreRead less