Deciphering The Molecular Steps Leading To The Potentiation Of Neuronal Exocytosis By Arachidonic Acid
Funder
National Health and Medical Research Council
Funding Amount
$273,000.00
Summary
Release of hormones and neurotransmitters relies on a process called exocytosis which involves SNARE proteins: syntaxin1A and SNAP-25 on the target plasma membrane and VAMP on the vesicular membrane. Availability of the t-SNARE on the plasma membrane is believed to play a major role in controlling the amount of exocytosis. Syntaxin1A bound to Munc18 constitute an 'unproductive-reserve' pool of closed Syntaxin that cannot interact with SNAP-25. Intracellular messengers capable of releasing Syntax ....Release of hormones and neurotransmitters relies on a process called exocytosis which involves SNARE proteins: syntaxin1A and SNAP-25 on the target plasma membrane and VAMP on the vesicular membrane. Availability of the t-SNARE on the plasma membrane is believed to play a major role in controlling the amount of exocytosis. Syntaxin1A bound to Munc18 constitute an 'unproductive-reserve' pool of closed Syntaxin that cannot interact with SNAP-25. Intracellular messengers capable of releasing Syntaxin1A from Munc18 thereby making it available to interact with SNAP-25, are foreseen to play a major role in potentiating exocytosis - a process with ramification for memory and learning. We have identified arachidonic acid, a lipidic messenger which fullfil this role. For the first time we are in a position to manipulate at the molecular level different pools of SNARE proteins with direct implications for our understanding of the mechanism of secretion. Very few models are currently available to understand how learning and memory occur in the brain. Our research points to a new direction: the amount of 'active' and 'unproductive-reserve' pools of SNARE proteins present on the plasma membrane of neurosecretory cells are in dynamic equilibrium and arachidonic acid, a second messenger capable of trans-synaptic action, can modify this equilibrium resulting in an increase of the amount of 'active' SNARE thereby potentiating the amount of transmitter-hormone released by exocytosis. Importantly, this research lays the basis for a dynamic view of the secretory mechanism with important implications for treatment of diseases such as diabetes and neurodegenerative diseases. Our hope is that by understanding at the molecular level how secretory cells regulate the amount of their secretion, we will be in a position to modify these parameters in order to counteract illnesses of the nervous system.Read moreRead less
Improving Synthetic Methodology To Prepare Pre-clinical Analogues Of Human Insulin
Funder
National Health and Medical Research Council
Funding Amount
$457,708.00
Summary
The glucose regulatory hormone, insulin, remains the only treatment for type I diabetes and up to 30% of type II diabetes, both of which are among the world’s fastest growing chronic diseases today. Because insulin, if taken orally, would be broken down quickly, it has usually been given by injection. This project will develop novel chemical methods for the efficient preparation of novel insulin therapeutics with improved stability and oral bioavailability for prolonged treatment of patients.
Next Generation Relaxin Molecular Probes And Therapeutics
Funder
National Health and Medical Research Council
Funding Amount
$763,845.00
Summary
The peptide hormone relaxin is poised to be the first new treatment for acute heart failure in more than 40 years. However, like other therapeutic peptides, it has a very short duration of action due to its rapid clearance by the body. My work will utilize powerful medicinal chemistry methods to develop new analogues of relaxin that have much longer action by complexing it with sugar or making relaxin polymers. I will also produce smaller relaxin analogues that will be cheaper to manufacture.
Chronic pain from damage to the nervous system is extremely debilitating and notoriously difficult to treat. The current drug of choice, gabapentin, has serious side effects and only works in two-thirds of patients. We have developed a drug, derived from sea snail venom, that exhibits ten times the activity of gabapentin. This proposal seeks to progress our drug to clinical trials and attract a commercial partner for its development into the market.