White Laboratory
| Contact: | Anthony White |
|---|---|
| Phone: | +61 3 8344 1805 |
| Fax: | +61 3 8344 4004 |
| Email: | arwhite@unimelb.edu.au |
The White laboratory studies biometals such as copper (Cu), zinc (Zn) and iron (Fe). These metals have important roles in normal cell metabolism. However, abnormal biometal metabolism is central to a number of neurodegenerative illnesses including Alzheimer's disease, Parkinson's disease and prion disorders (Creutzfeldt-Jakob and 'Mad Cow' diseases). Recent studies have shown that pharmacological modulation of biometal-protein interactions in the brain may offer a novel therapeutic approach to treating these brain diseases. An important step in developing these novel drugs is to obtain a clear understanding of how biometals affect neuronal survival, metabolism and cell death. Our laboratory is investigating the role of biometals in cell signaling events associated with cell survival and cell death pathways and identifying how these pathways are altered in brain diseases.
Key research areas are:
Modulation of amyloid beta production by metals and metal chelators.
Amyloid beta (Ab) peptide is deposited in the brain of patients with Alzheimer's disease. The aggregated form of Ab is neurotoxic and induces synaptic damage and neuronal dysfunction. Reduction in Ab levels in the brain is a major therapeutic target. We have identified a novel mechanism for metal-mediated Ab degradation in vitro. Internalization of metals delivered as metal-chelator complexes activates cell signaling pathways involving phosphoinositol-3-kinase and MAP kinases resulting in up-regulation of Ab -degrading metalloproteases. Further investigation is required to determine if similar pathways can be modulated in the brain to control Ab turnover.
Identification of novel drug targets in brain diseases using protein microarrays.
As a part of the Neuroproteomics & Neurogenomics Platform funded by Neurosciences Australia, our laboratory is developing protein microarray technology to identify novel protein drug targets in brain diseases. Protein microarrays are based on nanotechnology where hundreds or thousands of antibodies or proteins are spotted onto glass slides using a robotic protein-spotter. These arrays offer high sensitivity with low sample volumes and allow multiple target analysis from a single sample. This technology is still in its infancy but will become an invaluable tool for assessing biomarker expression and mapping of cellular pathways during disease processes. Our laboratory is developing this technology with the aim of identifying novel protein-based drug targets in Parkinson's disease, Creutfeldt-Jakob disease and Alzheimer's disease.
Understanding the role of metals in intracellular signaling pathways.
Biometals are central to the pathology of many brain diseases as well as cancer and inflammatory processes. However, little is known about the normal function of metals such as Cu and Zn in cell signaling pathways. These pathways affect cell growth, survival and death and are increasingly targeted for therapeutic intervention. It is critical to obtain a greater understanding of how metals modulate cell signaling during normal growth and disease. We are currently investigating how Cu and Zn affect common cell signaling pathways such as MAP kinase activity and growth factor receptor expression. Understanding how biometals affect these processes will help to clarify the role of metals in disease.
Developing technologies to transport large drug molecules across the blood brain barrier.
A major obstacle to effective therapy for neurodegenerative disorders is limited passage of therapeutics across the blood brain barrier (BBB). This is an area of widespread international interest as the obstacle also applies to the treatment of any brain disorder. New strategies will be investigated to target large or charged drug molecules across the BBB. These strategies include the use of protein transduction domains such as HIV Tat or anntenapedia, peptide cages or antibodies targeted to BBB antigens. The optimal approach will be selected and adapted to delivery of siRNA and antibody fragments to the brain for inhibiting expression of prion protein and additional proteins central to neurodegeneration.
Objectives
- Identifying and characterizing novel biometal-mediated cell signaling pathways involved in neurodegenerative diseases.
- Understanding how metals affect amyloid metabolism in the brain.
- Identifying new protein drug targets in prion diseases, Alzheimer's disease and parkinson's disease using protein microarray technology.
- Develop effective strategies for targeting drugs across the blood brain barrier.
Recent Achievements
- Identifying new biometal-mediated pathways involved in amyloid metabolism.
- Determining the role of trace metals in neuronal cell death pathways.
- Demonstrating a successful immunotherapeutic approach for the treatment of prion diseases.
- Identifying a role for the amyloid precursor protein in neuronal copper homeostasis.
Techniques
- Cell culture
- Immunoblotting
- Protein chemistry
- Molecular biology
- Microscopy
- Proteomics
- Protein microarrays
Collaborations
Departmental:
Dr Kevin Barnham, Prof. Ashley Bush, Dr Roberto Cappai, Dr Robert Cherny, Prof. Steven Collins and Dr Qiao-Xin Li.
University:
Dr Andrew Hill (Bio21), Prof. James Camakaris (Genetics), Dr Paul Donnelly (Bio21).
External:
Dr Michael Abdo (CSIRO), Dr Sharon La Fontaine (Deakin University).
International Collaborators:
Dr Xudong Huang ( Massachusetts General Hospital , USA ) Prof. Gerd Multhaup ( Free University , Berlin , Germany ).
Funding
- NHMRC Program Grant
- NHMRC Research Fellowship
- Brain Foundation.
- University of Melbourne and CSIRO Collaborative Research Grants Scheme.
- Neurosciences Australia (Neuroproteomics and Neurogenomics Platform).
Recent Publications
- White, A.R., Barnham, K.J., Huang, X., Volitakis, I., Beyreuther, K., Masters, C.L., Cherny, R.A., Bush, A.I. and Cappai, R. Iron inhibits neurotoxicity induced by trace copper and biological reductants. Journal of Biological Inorganic Chemistry (2004) 9, 269-280.
- White, A.R., Enever, P., Tayebi, M., Mushens, R., Linehan, J., Brandner, S., Anstee, D., Collinge, J. and Hawke, S.H. Monoclonal antibodies inhibit prion replication and delay the development of prion disease. Nature (2003) 422, 80-83.
- White, A.R. and Hawke, S.H. Immunotherapy as a therapeutic treatment for neurodegenerative diseases. Journal of Neurochemistry (2003) 87, 801-808.
- Bellingham, S. A., Ciccotosto, G. D., Needham, B. E., Fodero, L. R., White, A. R., Masters, C. L., Cappai, R., & Camakaris, J. (2004). Gene knockout of amyloid precursor protein and amyloid precursor-like protein-2 increases cellular copper levels in primary mouse cortical neurons and embryonic fibroblasts. Journal of Neurochemistry , 91 , 423-28.
- White, A. R., Multhaup, G., Galatis, D., McKinstry, W. J., Parker, M. W., Pipkorn, R., Beyreuther, K., Masters, C. L., & Cappai, R. (2002). Contrasting, species-dependent modulation of copper-mediated neurotoxicity by the Alzheimer's disease amyloid precursor protein. Journal of Neuroscience , 22 , 365-76.
- White, A.R., Guirguis, R., Brazier, M.W., Jobling, M.F., Hill, A.F., Beyreuther, K., Barrow, C.J., Masters, C.L., Collins, S.J. and Cappai, R. Sub-lethal concentrations of prion peptide PrP106-126 or the amyloid beta peptide of Alzheimer's disease activates expression of pro-apoptotic markers in primary cortical neurons. Neurobiology of Disease (2001) 8, 299-316.