Secretion is an essential step in memory and learning, control of metabolism and reproduction and the functioning of most organs. Secretory dysfunction also underlies many diseases including type 2 diabetes. We plan experiments to test for a new model of control of insulin secretion.
Do Synaptic-like Mechanisms Control Insulin Secretion?
Funder
National Health and Medical Research Council
Funding Amount
$593,235.00
Summary
An estimated 415 million people world-wide were diagnosed with diabetes in 2015. One of the causal factors in disease is the dysregulation of insulin secretion. We have developed new techniques to study insulin secretion that has led us to propose a new model for secretory control. This proposal sets out experiments to critically test this model. The outcomes could have wide-reaching impact on understanding and for future treatment and prevention of the diabetes.
Why We Have Two Estrogen Receptors: The Role Of ERbeta In Folliculogenesis.
Funder
National Health and Medical Research Council
Funding Amount
$576,053.00
Summary
The female hormone estrogen acts via receptors ERalpha and ERbeta. Little is known about the genes and proteins regulated by ERbeta. Ovarian granulosa cells and granulosa cell tumours express ERbeta. By studying the biology of normal and malignant granulosa cells we hope to understand the role that ERbeta plays in granulosa cells. These studies will identify areas for the development of new therapeutics or treatment strategies for a range of female-specific conditions including ovarian cancer.
Follicle-stimulating hormone (FSH) is vital for egg development, female fertility and health, and is widely used in assisted reproduction technology. But high levels of FSH are associated with premature infertility and menopause, and may lead to diseases like ovarian cancer. Understanding the biological pathways activated by elevated FSH may lead to new treatments for infertility and ovarian diseases (eg. cancer), as well as advancing new strategies for contraception.
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
Hormonal Influences In The Pathogenesis Of Ovarian Tumours
Funder
National Health and Medical Research Council
Funding Amount
$264,601.00
Summary
Ovarian cancer is one of the most common malignancies affecting the female reproductive system. We have found that two types of tumour of the ovary produce a hormone called inhibin; these tumours are also known to produce the steroid hormone estrogen. In these studies we are seeking to determine the genetic changes in the tumours that cause the production of these hormones. We suspect that these genetic changes are also the same changes which contribute to the development of the cancers. In orde ....Ovarian cancer is one of the most common malignancies affecting the female reproductive system. We have found that two types of tumour of the ovary produce a hormone called inhibin; these tumours are also known to produce the steroid hormone estrogen. In these studies we are seeking to determine the genetic changes in the tumours that cause the production of these hormones. We suspect that these genetic changes are also the same changes which contribute to the development of the cancers. In order to identify these genes we will draw on our knowledge of the genes that are important in the controlof growth and hormone secretion in normal ovarian cells. To assist this molecular analysis we will use two ovarian cell lines in culture that have many of the features of the primary tumours including inhibin secretion. We will also use new techniques to scan over 500 genes involved in tumours in general to see whether we detect any unusual or distinctive patterns in this sub-group of tumours. A genome wide scanning technique will be used to seek changes in the DNA of the tumours, inparticular loss of genetic material or amplification of regions. Identification of the genetic changes within these tumours should enable better systems of classification, enhance prognostication and provide specific targets for the development of appropriate treatment strategies.Read moreRead less