Role And Mechanism Of Connective Tissue Growth Factor In Diabetic Cardiomyopathy
Funder
National Health and Medical Research Council
Funding Amount
$382,820.00
Summary
Diabetic cardiomyopathy is a condition where the heart muscle is directly damaged by diabetes. It is being recognised as a prominent cause of both acute and chronic heart failure in diabetes. It is common and occurs in up to 60% of diabetic patients . At present however, no treatments are available to directly treat the cardiomyopathy. This condition can also occur in people with diabetes who have high blood pressure and-or coronary artery disease and may combine with these problems to worsen pa ....Diabetic cardiomyopathy is a condition where the heart muscle is directly damaged by diabetes. It is being recognised as a prominent cause of both acute and chronic heart failure in diabetes. It is common and occurs in up to 60% of diabetic patients . At present however, no treatments are available to directly treat the cardiomyopathy. This condition can also occur in people with diabetes who have high blood pressure and-or coronary artery disease and may combine with these problems to worsen patient outcomes. We have generated data in experimental diabetes in rodents that strongly implicates a heart growth factor in causing diabetic cardiomyopathy. This protein, called connective tissue growth factor (CTGF), is increased in diabetic cardiomyopathy, and is elevated by high glucose and other factors in diabetes. We have published data showing that CTGF causes tissue scarring like that which occurs in cardiomyopathy, by affecting signals in cells called fibroblasts. It increases the laying down of extracellular matrix (ECM) and also inhibits the degradation of ECM by the proteins that break down matrix, known as the MMPand PAI systems. Such accumulation of ECM is thought to be a major factor leading to abnormal muscle function in cardiomyopathy. We now plan to block CTGF in this diabetic heart model to determine if we can prevent diabetic cardiomyopathy. We have generated two methods to inhibit CTGF in the animal model. Echocardiography (a heart ultrasound test), and molecular analysis of the heart tissue will determine if we can prevent the otherwise adverse functional and structural changes of diabetes in the heart. We will also study our baboon model of diabetes to determine if diabetic cardiomyopathy with increased heart CTGF is present in the primates. Cell culture studies from rat heart fibroblasts and myocytes will determine how CTGF has the effect on cells to cause cardiomyopathy and how we might further prevent this condition developing in diabetes.Read moreRead less
The Effect Of Androgen Replacement Therapy On Bone And Muscle Health In Men With Chronic Kidney Disease
Funder
National Health and Medical Research Council
Funding Amount
$122,714.00
Summary
Low testosterone (T) levels are common in men with poor kidney function. Low T is known to cause reduced energy, decreased strength and low libido. Normal T is also needed for healthy bones and muscles. Men with kidney disease are already at risk of fractures, poor strength and quality of life. However, there are few studies that look at replacing T to men with kidney failure. We will investigate how low T affects bone and muscle and assess how giving T can benefit bone, muscle and function.
The Nuclear Growth Hormone Receptor- Its Actions And Mechanism Of Nuclear Translocation
Funder
National Health and Medical Research Council
Funding Amount
$531,696.00
Summary
We and others have found that cell surface receptors for growth factors such as EGF, FGF and growth hormone can be found in the nucleus of proliferating cells. We have shown that many cancers have elevated nuclear GH receptor including leukemia, breast and colon cancer. If we artificially target the GH receptor to the nucleus, the resulting cells are tumorigenic when injected into immunocompromised mice, rapidly form ing metastasising tumours. To create more effective inhibitors of this tumourog ....We and others have found that cell surface receptors for growth factors such as EGF, FGF and growth hormone can be found in the nucleus of proliferating cells. We have shown that many cancers have elevated nuclear GH receptor including leukemia, breast and colon cancer. If we artificially target the GH receptor to the nucleus, the resulting cells are tumorigenic when injected into immunocompromised mice, rapidly form ing metastasising tumours. To create more effective inhibitors of this tumourogenesis, and to define the physiological roles of nuclear GH receptor, we will define the transport process which carries the receptor to the nucleus and block it. We will also seek to define how the receptor in the nucleus interacts directly with DNA to inhibit programmed cell death. To carry out these projects we will use sophisticated proteomics -mass spectrometry to identify the proteins interacting with the receptor in the transport and gene activation processes. The role of candidates will be tested by preventing their expression or by direct inhibition of their action using drugs or dominant negative versions. These approaches will provide leads to new anti-cancer therapeutics, and therapies for blocking diabetic blindness and kidney failure.Read moreRead less
Constitutive Activation Of The Growth Hormone Receptor
Funder
National Health and Medical Research Council
Funding Amount
$566,277.00
Summary
Growth hormone regulates growth, metabolism, bone, stem cells and longevity, and cancer. These actions are mediated by the GH receptor, and here we seek to understand how it is activated by the hormone through receptor constructs which are active without hormone, to different degrees. We will use these to elucidate its signaling properties, its ability to promote cancer, to grow muscle, and whether cases of giantism and cancer are a consequence of the activating mutations we have identified.
REGULATION OF ANDROGEN RECEPTOR And ErbB-2 GENE EXPRESSION IN PROSTATE CANCER: ROLE OF THE HU PROTEINS
Funder
National Health and Medical Research Council
Funding Amount
$471,000.00
Summary
Carcinoma of the prostate (PCa) is the most common malignancy affecting males and causes enormous morbidity and mortality in Australia. It is the second leading cause of death in men in Western countries. About one third of men relapse after radical prostatectomy because of previously undetectable metastatic disease. Androgens, acting via the androgen receptor (AR) a nuclear transcription factor that regulates a set of largely unknown androgen-responsive genes, promote the growth of prostate can ....Carcinoma of the prostate (PCa) is the most common malignancy affecting males and causes enormous morbidity and mortality in Australia. It is the second leading cause of death in men in Western countries. About one third of men relapse after radical prostatectomy because of previously undetectable metastatic disease. Androgens, acting via the androgen receptor (AR) a nuclear transcription factor that regulates a set of largely unknown androgen-responsive genes, promote the growth of prostate cancer cells. Thus the AR is a major target for therapy. Even when the disease is unresponsive to androgen withdrawal, the AR is present. Furthermore, we know that these PCa cells recruit other androgen-independent pathways to activate growth. One such pathway is the erbB-2 signaling cascade, which drives the cells towards proliferation. Proteins that bind to RNA, the cellular messenger, are playing an increasing role in the biology of cancer. HuR, a member of the Hu-Elav family, augments growth of colon cancer cells, and is associted with poor outcomes in ovarian and brain malignancies. We have recently identified the first proteins that bind to AR and erbB-2 mRNA. Remarkably, HuR binds to both sequences. Furthermore, HuD, another member of the Hu-Elav family which is normally only found in the brain, is aberrantly expressed in human PCa. In this Project we will determine the effects of these proteins on the growth of human PCa cells in culture and in whole animal models. We will also evaluate their presence in a large array of human PCa specimens. It is envisaged that this work will develop novel links between the two pathways bringing them together in a previously unrecognised manner. We also aim to solve the molecular structure of Hu proteins bound to the AR mRNA. Outcomes of the work will include new potential tests for prostate cancer and improved prognosis prediction, and establishment of a foundation for the development of novel targets for therapy.Read moreRead less
Diabetic cardiomyopathy (DiabCM) is common in people with diabetes. It predisposes to heat failure. Its cause remains unclear and there is no specific treatment for DiabCM. Inflammation is a fundamental tissue response to a metabolic insult and it occur in DiabCM. The central hypothesis in this work is that inflammation through myocardial macrophage cells contributes to DiabCM. This hypothesis will be tested in animal models and also in cell culutre studies.
Diabetes mellitus is a disease reaching epidemic proprotions in the western world. Nearly one million Australians have diabetes mellitus; many of these people will suffer debilitating secondary complications, resulting in significant morbidity and mortality at considerable social and economic cost. Complications include heart attack, stroke, kidney disaease, blindness and limb amputation. There are two forms of diabetes (type I and type 2), and though there are considerable differences in their ....Diabetes mellitus is a disease reaching epidemic proprotions in the western world. Nearly one million Australians have diabetes mellitus; many of these people will suffer debilitating secondary complications, resulting in significant morbidity and mortality at considerable social and economic cost. Complications include heart attack, stroke, kidney disaease, blindness and limb amputation. There are two forms of diabetes (type I and type 2), and though there are considerable differences in their etiology, both forms result in an inability of the body to control blood sugar levels. Beta cells release the hormone insulin, which regulates blood sugar levels. Current knowledge suggests that a loss of beta cell mass is important for both diseases. For type I diabetes the beta cells are destroyed by the immune system. Though for type 2 diabetes the causes are less clear, it is apparent that the beta cells are dying. Our research is focused on understanding the molecular pathways that control beta cell survival and regulate their death. Such knowledge would help us understand the complex processes leading to the development of diabetes. Furthermore, we could use this knowledge in the design of genetic engineering strategies to create 'death-defying' beta cells, as a potential therapeutic strategy for the treatment of diabetes.Read moreRead less