The Stem Cells and Disease Models Laboratory combine expertise in human stem cell biology, neurobiology and tissue engineering in order to study and further our understanding of diseases of the human brain, with an emphasis on Autism Spectrum Disorders (ASD) and Friedreich’s Ataxia (FRDA).
One of the focuses of the lab is to derive, differentiate and investigate human neural and pluripotent stem cells, which naturally express or are engineered to express genes related to our disorders of interest. Our approach fits well with the notion that a better understanding of the biological mechanisms underlying mental disorders is vital for improved diagnostics and therapies. Our in vitro models incorporate neural differentiation to recapitulate key events of human brain development including induction of region-specific neural progenitors and terminally differentiated neurons and glia in order to better understand the cellular and molecular networks underlying central nervous system disorders. Our approach is complimentary to in vivo experimentation and other conventional research methods, and fits well with the broadly accepted notion that a better understanding of the biological mechanisms underlying central nervous system disorders must be forthcoming before new drugs with increased therapeutic impact can be developed. Once characterised, our cell models can be employed for drug screening towards developing new CNS active medicines.
To find out more about the research undertaken at this laboratory, please contact:
Human Brain Development and Function
The human nervous system is one of the most complex structures evolved to date. In order to understand how it functions, and dysfunctions in a diseased state, it is fundamental to decipher how it creates various neuronal populations that form its elaborate networks. Our research uses human stem cells as a cellular model system to study the development and specification of cortical neurons. Our laboratory has established robust differentiation systems for deriving specific populations of cortical neurons from hPSC, including glutamatergic deep layer and intermediate layer neurons and inhibitory GABAergic neurons. Using multi-electrode array (MEA) technologies, we study how these neurons mature and from functional networks in culture to essentially model cortical networks. Furthermore, working amongst engineers has fostered unique opportunities for complementary cross-disciplinary research in neuroscience and bioengineering.This includes assessing scaffold materials, such as graphene, that are electrically conductive and support three-dimensional growth and maturation of hPSC-derived cortical neurons. These studies are significant for modeling human brain development within a 3D context.
An extension of this research program is to use stem cells to study complex neurological disorders that may have an underlying neurodevelopmental etiology. In particular, our focus is on autism spectrum disorders (ASD), whereby we have generated induced pluripotent stem cell (iPSC) lines from idiopathic ASD patients. In our laboratory we have established in vitro brain organoid cultures from iPSC to model cortical neuronal patterning and specification, which is being applied to the ASD iPSC lines. Our data to date shows gene expression pattern differences in the ASD iPSC lines that are consistent with clinical studies. These findings support the use of patient-derived iPSC for modelling neurological conditions that have a neurodevelopmental origin.
Functional and Phenotypic Characterization of Cortical Neurons Derived from Human Pluripotent Stem Cells
The fundamental purpose of the sensory nervous system is to receive and transmit information to the brain, which initiates how we interpret our external and internal world and consequently influences what responses will be made. Dorsal root ganglia (DRG) sensory neurons enable us to sense temperature, pressure, position and pain. Not surprisingly, there are vast ranges of diseases and conditions, usually progressive, which can cause DRG neuropathies. For some diseases, such as Friedreich ataxia (described below), DRG neuropathy is severely debilitating such that patients are unable to walk. To address this, it would be valuable to have a source of cultured human DRG neurons to examine potential causes and also therapies, including drug screening, as well as to study regenerative mechanisms.
We have developed an efficient and fully chemically defined system to generate DRG neurons from human pluripotent stem cells, which includes the three major sensory neuronal populations; proprioceptive, nociceptive, mechanoceptive neurons. Within each major sensory neuronal population, we have identified sensory neuron subtypes that express similar gene expression profiles to that found in the rodent. In conjunction to phenotypic analyses, functional characterization studies of sensory DRG neuronal subpopulations are examined both in vitro using MEA technologies and in vivo by transplantation studies into adult rodent DRG regions. Taken together, these analyses provide fundamental knowledge about the development and functionality of the human sensory system, which can be applied to developing regenerative therapies for treating peripheral neuropathies.
Developing Treatments for Friedreich Ataxia
Friedreich ataxia (FRDA) is an autosomal recessive disease characterised by neurodegeneration and cardiomyopathy and is the most common form of all inherited ataxias known to date. The cause of FRDA is due to mutations in the FXN gene, resulting in an insufficiency of the mitochondrial protein, Frataxin. Reduced levels of Frataxin protein leads to mitochondrial dysfunction, cell toxicity and cell death, particularly within the nervous system and cardiac tissue. The cell types within the nervous system that are predominantly affected are the DRG sensory neurons and deep nuclei cerebellar neurons.
In FRDA research there is a strong need to develop human cellular models of the disease to further study the cellular pathology of FRDA as well as develop therapies. To meet these needs, we generated iPSC lines derived from skin biopsy samples of FRDA patients and showed that they retained the fundamental genetic characteristics of this disease. We have also generated cortical neurons from FRDA iPSC and analysed their mitochondrial and functional activities. Importantly, our expertise in deriving sensory DRG neurons from hPSC is now being applied to FRDA iPSC, to analyse mitochondrial and cellular function in this population. Functional analyses of FRDA iPSC-derived sensory neurons also includes in vivo transplantation studies into rodent adult DRG regions. Altogether, these studies are highly significant for using iPSCs to develop of treatments for FRDA, whether by drug discovery approach or transplantation.
|Assoc Prof Mirella Dottori||Laboratory Head and Senior Research Fellow|
|Dr Giovanna D’Abaco||Research Fellow; Lab Manager for CfNE|
|Dr Ana Antonic||Research Fellow|
|Rachael Chatterton||Research Assistant|
|Pegah Jamshidi||Research Assistant|
|Tejal Kulkarni||Research Assistant|
|Abdullah Alshawaf||PhD student, co-supervised with Prof S Skafidas, Dr G Chana and Prof I Everall|
|Serena Viventi||PhD student, co-supervised with Prof S Skafidas|
|Cristiana Mattei||PhD student, co-supervised with Prof S Skafidas and Dr G D’Abaco|
|Kwaku Dad Abu-Bonsrah||PhD student, co-supervised with Dr D Newgreen (Murdoch Childrens Research Institute)|
|Liliana Laskaris||PhD student, co-supervised with Dr G Chana, Prof S Skafidas and Prof C Pantelis|
|Ting Ting Lee||PhD student, co-supervised with Dr G Chana, Prof S Skafidas and Prof I Everall|
|Charlotte Hall||PhD student, co-supervised with Dr M Coleman (University of Birmingham, UK) and Dr G D’Abaco|
|Michal Easton Mor||PhD student, co-supervised with Dr G Chana, Dr G D’Abaco and Dr M Familari|
|Emma Hudson||Master student, co-supervised with Dr G D’Abaco|
Denham M, Hasegawa K, Menheniott T, Rollo B, Zhang D, Hough S, Alshawaf A, Febbraro F, Ighaniyan S, Leung J, Elliott D, Newgreen DF, Pera MF and Dottori M. (2015) Multipotent caudal neural progenitors derived from human pluripotent stem cells that give rise to lineages of the central and peripheral nervous system. Stem Cells (DOI: 10.1002/stem1991).
Bird MJ, Needham K, Frazier AE, van Rooijen J, Leung J, Hough S, Denham M, Thornton ME, Parish CL, Nayagam BA, Pera M, Thorburn DR, Thompson LH, Dottori M. (2014) Functional characterization of Friedreich ataxia iPS-derived neural progenitors and their integration in the adult brain. Plos One 9(7):e101718.
Needham K, Hyakumura T, Gunewardene N, Dottori M and Nayagam BA. (2014) Electrophysiological properties of neurosensory progenitors derived from human embryonic stem cells. Stem Cell Res. 12: 241–249.
Denham M, Bye, C, Conley BJ, Leung J, Thompson LH and Dottori M. (2012) Glycogen synthase kinase 3b and activin/nodal inhibition in human embryonic stem cells induces a pre-neuroepithelial state that is required for specification to a floor plate cell lineage. Stem Cells 30:2400–2411
Denham M and Dottori M. (2011) Neural differentiation of induced pluripotent stem cells. Methods Mol Biol. Neurogeneration: Methods and Protocols. Editors, Manfredi G and Kawamata, H. Humana Press. 793:99-110.
Liu J, Verma PJ, Evans-Galea M, Delatycki MB, Michalska A, Leung J, Crombie D, Sarsero JP, Williamson R, Dottori M* and Pébay A* (2011) Generation of Induced Pluripotent Stem Cell Lines from Friedreich Ataxia Patients. Stem Cells Reviews and Reports 7:703–713. *Equal last authors.
Denham M, Thompson LH, Leung J, Pébay A, Björklund A and Dottori M. (2010) Gli1 is an Inducing Factor in Generating Floor Plate Progenitor Cells From Human Embryonic Stem Cells. Stem Cells 28: 1805–1815.
Denham M and Dottori M. (2009) Signals Involved in Neural Differentiation of Human Embryonic Stem Cells. NeuroSignals 17: 234–241.
Hotta R, Pepdjonovic L, Anderson RB, Zhang D, Bergner AJ, Leung J, Pébay A, Young HM*, Newgreen DF*, Dottori M*. (2009) Small Molecule Induction of Neural Crest-like Cells derived from Human Neural Progenitors. Stem Cells 27:2896–2905. *Equal last authors.
Dottori M and Pera M.F. Neural differentiation of human embryonic stem cells. (2008) Methods Mol Biol Neural Stem Cells, Sec Ed. Editor L.P.Weiner. The Humana Press Inc. 438; 19–30.