Extracellular Vesicle Group
All cells in our body release tiny biological nanoparticles into their environment. These nanoparticles are called extracellular vesicle or ‘EVs’ for short. Extracellular vesicles are natures postal service, they deliver molecular information from cell to cell and around the body. Our team studies the contribution of EVs to the progression of dementia and brain cancer and uses EVs as a tool for identifying dysfunctional cellular pathways. We aim to 1) gain insights about the biological origins of disease to identify novel therapeutic targets and 2) identify molecular species in EVs that could be used as disease biomarkers.
Abour our research
- Extracellular vesicles (EVs)
- Alzheimer’s disease
- Parkinson’s disease
- Huntington’s disease
- Brain cancer
- Extracellular vesicle biologics
The current projects in the EV lab include:
Do microbiota-derived outer membrane vesicles contribute to inflammation and neurodegeneration in Parkinson’s disease?
The microbiota-gut-brain axis is beginning to take centerstage in Parkinson’s disease (PD) research, as the spotlight becomes fixed on microbiotic dysbiosis as a contributor to PD pathogenesis. It is hypothesised that the gut microbiota promotes local, systemic, and neural inflammation, which can promote neurodegeneration in PD, however how bacteria influence these processes remains unclear. We propose that Outer membrane vesicles (OMVs) released from gram-negative bacteria are a mediator of PD, due to their immune stimulatory composition, including containing potent lipopolysaccharides (LPS) and capability to impact gastrointestinal permeability and influence global inflammation.
Methodology: OMVs are isolated from bacterial culture or murine faeces and characterized by density, size, morphology, LPS content and ability to stimulate immune cells in vitro. OMVs from bacterial culture or an equivalent dose of LPS are orally administered to a PD model mouse to determine if OMVs contribute to the acceleration and exacerbation of PD inflammation, and gastrointestinal and neurological dysfunction.
Optimization of plasma extracellular vesicle enrichment for in-depth lipidomic profiling in Alzheimer’s disease
Lipid dyshomeostasis is associated with various disorders including Alzheimer’s disease (AD). The work from our laboratory (Su et al, JEV 2021), and others, suggests that extracellular vesicles (EVs) contain lipid biomarkers that could aid in the diagnosis of AD and diseases associated with impaired lipid metabolism.
Knowing the lipid content of EVs is a key first step to discovering EV-based lipid biomarkers in blood. Some studies have reported the lipid content of ‘’EVs’’ in blood. However, used EV isolation techniques that are known to co-isolate free lipid and lipoproteins.
In this project we aim to
- demonstrate the importance of size exclusion resin size to isolating highly enriched EVs for lipidomic analysis
- develop a reference EV plasma lipidome for the research community
- determine if plasma EVs report on lipid dyshomeostasis in Alzheimer’s disease.
Methodology: Human plasma EVs are isolated using commercially available kits or by density fractionation and size exclusion chromatography and characterised by western blot, transmission electron microscopy, and quantitative mass spectrometry based proteomic and lipidome analysis.
This project is in collaboration with Professor Gavin Reid and Associate Professor Kevin Barnham.
Exosomes are a tool for integrating oxidative stress pathways and mitochondrial dysfunction in Parkinson’s disease
Here, we are using exosomes as a tool to interrogate the intracellular pathways implicated in Parkinson’s disease. We hypothesise that the composition of exosomes will provide fresh insight into the pathophysiology of the disease and thereby reveal potential disease biomarkers and therapeutic targets.
Methodology: EVs are studied in the context of cell culture models of subtle mitochondrial dysfunction and oxidative stress and in tissues from individuals with Parkinson’s disease.
The role of brain-derived extracellular vesicles in Huntington’s disease
Capable of delivering lipid, protein, and nucleic acids to both nearby and distal cells, EVs have been hypothesized to contribute to the progression of neurodegenerative diseases, including Huntington’s disease (HD). To date, most analyses on the role of these vesicles in the healthy and diseased state have relied on studying vesicles from in vitro sources, such as conditioned cell culture media, or body fluids. Here, we are isolating EVs direct from mouse and human Huntington’s brain tissue. Understanding the role of EVs in HD will inform pathogenic mechanisms of the disease and could lead to the identification of new therapeutic targets.
- Isolation of extracellular vesicles from blood plasma, conditioned media (primary and secondary cell lines), human and murine brain tissue, tumour tissue, milk, bacterial cultures, faeces, nasal fluid and cerebrospinal fluid.
- Extracellular vesicle isolation techniques including size exclusion, density gradients, tangential flow filtration, immunocapture or ultracentrifugation.
- The manufacture, characterisation and analytics of extracellular vesicle biologics
- Extracellular vesicle characterization (immunoblot, particle analysis, transmission electron microscopy and cryo-electron microscopy and proteomics and lipidomics (in collaboration with Professor Gavin Reid).
- In vitro assays (neuronal, glial and co-cultures) to determine EV (human, murine or bacterial EV) function.
- Preclinical translation of extracellular vesicles derived from murine and human extracellular vesicles. Includes animal (mice) models of adult and childhood dementia (transgenic) and Parkinson’s disease (transgenic and neurotoxin induced) and associated behavioral readouts and biochemical assays.
Research and technical staff
- Mitali Manish Kulkarni
- Kate Su
- Adityas Purnianto
- Tiana Koukoulis
- Kate Su
- Oliver Wood
- Mitali Manish Kulkarni
- Patricia Wongsodirdjo
- Annmarie Tripodi
- Su, H., Rustam, Y.H., Masters, C.L., Makalic, E., McLean, C.A., Hill, A.F., Barnham, K.J., Reid, G.E. and Vella, L.J. (2021). Characterization of brain‐derived extracellular vesicle lipids in Alzheimer’s disease. Journal of Extracellular Vesicles, 10(7). doi:https://doi.org/10.1002/jev2.12089.
- Bajracharya, R., Caruso, A.C., Vella, L.J. and Nisbet, R.M. (2021). Current and Emerging Strategies for Enhancing Antibody Delivery to the Brain. Pharmaceutics, [online] 13(12), p.2014. doi:https://doi.org/10.3390/pharmaceutics13122014.
- Whitehead, C.A., Kaye, A.H., Drummond, K.J., Widodo, S.S., Mantamadiotis, T., Vella, L.J. and Stylli, S.S. (2019). Extracellular vesicles and their role in glioblastoma. Critical Reviews in Clinical Laboratory Sciences, 57(4), pp.227–252. doi:https://doi.org/10.1080/10408363.2019.1700208.