TGF-beta Receptor Type III In Normal And Malignant Liver Growth: Modulation Of TGF-beta Activity
Funder
National Health and Medical Research Council
Funding Amount
$361,527.00
Summary
The transforming growth factor-beta (TGF-beta) family is a group of multifunctional growth factors which regulates a number of important cellular functions, including proliferation, differentiation, and survival. Therefore, the proper functioning of this system is critical for the normal development and maintenance of most tissues. Dysregulation of this system is implicated in many pathological conditions, including cancer. The actions of TGF-beta are mediated by three cell surface proteins, ter ....The transforming growth factor-beta (TGF-beta) family is a group of multifunctional growth factors which regulates a number of important cellular functions, including proliferation, differentiation, and survival. Therefore, the proper functioning of this system is critical for the normal development and maintenance of most tissues. Dysregulation of this system is implicated in many pathological conditions, including cancer. The actions of TGF-beta are mediated by three cell surface proteins, termed the type I, II and III TGF-beta receptors. The type I and II receptors are required for transmitting the TGF-beta signal to the nucleus of the cell. Existing data suggest that the type III receptor is not required in TGF-beta signaling but is required for the regulation of TGF-beta levels at the cell surface. However, the function of this receptor and its role in TGF-beta mediated regulation of cell growth and survival is poorly understood. Our earlier work indicated that the TGF-beta type III receptor is particularly important for limiting TGF-beta activity during normal liver development. The currently proposed research will examine the effects of type III receptor deficiency on liver cells in the adult mouse in order to determine whether alterations in cell growth and survival occur in the absence of this receptor. Becauses TGF-beta is a key regulator of liver growth and altered levels of TGF-beta in liver have been demonstrated to lead to liver cancer in mice, we anticipate that targeting the deletion of the type III gene to liver cells will provide a system in which to study compromised regulation of cell growth. This work is therefore expected to yield information relevant to the role of this receptor in TGF-beta regulated processes in normal and cancerous growth. Because the type III receptor appears to control the level of TGF-beta activity, this work will allow further evaluation of the potential for therapeutic uses for type III receptor-like agents.Read moreRead less
Cell-selective Deletion Of Brain AT1A Receptors In Hypertension: Effect On Blood Pressure, Increased ROS Production And Inflammation.
Funder
National Health and Medical Research Council
Funding Amount
$578,268.00
Summary
Angiotensin is important for normal regulation of blood pressure but is also involved in cardiovascular diseases. Interruption of angiotensin’s actions is a common treatment of these diseases. Functional deletion of angiotensin receptors decreases blood pressure. Surprisingly the site(s) in the body responsible for this decrease are not known. We will examine the role of angiotensin receptors in the brain in the control of blood pressure in health and in cardiovascular disease.
The Role Of Androgens In Osteoblast Development And Bone Metabolism
Funder
National Health and Medical Research Council
Funding Amount
$64,631.00
Summary
Male hormones are essential for the growth and maintenance of bone in men, but exactly how and when they act on the bone forming cells is unclear. We aim to find out what happens when the target for male hormones (receptor) is removed in the bone forming cells at different stages of their development. This project will increase our understanding of how male hormones regulate bone formation and may assist in the design of new therapies for osteoporosis.
Feeding Behaviour And Obesity Development: Identification Of Novel Intervention Points
Funder
National Health and Medical Research Council
Funding Amount
$923,668.00
Summary
Appetite and food intake is regulated by specific neuronal structures in the brain. The most important area is the hypothalamus from which many neuronal pathways originate to control specific aspects of feeding behaviour and energy usage in the brain and the rest of the body. To better understand the contribution individual neuronal populations make to drive excess food intake we propose a new approach to identify this, making new treatment options for eating disorders and obesity possible.
The Effect Of PKC Epsilon On The Insulin Receptor And Whole Body Glucose Homeostasis.
Funder
National Health and Medical Research Council
Funding Amount
$82,261.00
Summary
Increased fat availability is strongly associated with insulin resistance and type 2 diabetes. Data from this lab has shown animals lacking a particular enzyme (Protein Kinase C epsilon) are able to compensate for this insulin resistance and maintain normal blood glucose levels by elevating insulin availability, with a major site of action being the liver. This project therefore aims to examine the action of PKC epsilon on insulin clearance by the liver.
Distinct Populations Of Arc NPY Neurons Control Different Aspects Of Energy Homeostasis
Funder
National Health and Medical Research Council
Funding Amount
$843,340.00
Summary
Obesity is caused by an imbalance of energy intake and energy expenditure both of which are controlled by specific neurons in the brain. While different types of neurons important in these processes have been identified how they are organised and work in fulfilling the different functions is unclear. Here we aim to identify subpopulations of neurons that are responsible for specific tasks that would make them more specific targets for drug intervention with a reduced risk of side effects.
Epilepsy is an important human disease because it causes physical trauma and sudden death in addition to immense social and economic hardship. The genetic basis of a number of epilepsy syndromes has been identified but the precise mechanism whereby mutations produce seizures is unknown. Several mutations in the alpha4 neuronal nicotinic receptor (a4 nAChR) gene have been identified in Autosomal Dominant Nocturnal Frontal Lobe Epilepsy (ADNFLE). This is a rare form of inherited epilepsy character ....Epilepsy is an important human disease because it causes physical trauma and sudden death in addition to immense social and economic hardship. The genetic basis of a number of epilepsy syndromes has been identified but the precise mechanism whereby mutations produce seizures is unknown. Several mutations in the alpha4 neuronal nicotinic receptor (a4 nAChR) gene have been identified in Autosomal Dominant Nocturnal Frontal Lobe Epilepsy (ADNFLE). This is a rare form of inherited epilepsy characterized by the presence of seizures during light sleep. In vitro studies using the human mutated DNA (i.e. DNA containing the genetic defect) have suggested that this mutation results in reduced activity of the receptor. Therefore a mouse in which this gene is destroyed would be relevant in understanding the human disease. We have generated an a4 nAChR knockout (KO) mouse and plan to use the mouse to test the idea that loss of function of the a4 nAChR in vivo is associated with enhanced seizure activity. The KO mice do not have unprovoked seizures but appear to have an increased number of major motor seizures in response to pentylenetetrazole, an agent which is known to cause seizures by blocking the effects of the brain inhibitory molecule GABA. Interestingly, a4 nAChRs are known to control the release of GABA. We therefore propose that our knockout mice have seizures because they tend to under produce GABA. We will also make and analyse a mouse line with the same genetic mutation as patients with ADNFLE. The experiments are aimed at understanding the way that seizures are generated and spread in the brain in these rare forms of epilepsy. The hope is that understanding these mechanisms will help us better understand and therefore treat common forms of epilepsy.Read moreRead less