Neurodegenerative disorders and cerebral ischemia are incurable conditions, imposing tough medical challenges and a substantial economic burden on health services. Pathogenic causes for gradual deterioration and eventual loss of nerve cells are not yet understood. Intriguingly, growing evidence from both in vitro studies using cultured non-human mammalian neurons and in vivo studies using animal models, has indicated important roles for one type of protein post-translational modification termed as SUMOylation (1), which involves attachment of a small protein called Small Ubiquitin-related Modifier (SUMO) to target proteins, in neurodegenerative disorders (e.g., Alzheimer’s disease, Parkinson’s disease and amyotrophic lateral sclerosis) and cerebral ischemia (2-4). However, those scientific findings have not yet been translated into disease prevention/treatment largely due to limited access to functional human brain tissues. Remarkably, recently technology advance in generation of ‘cerebral organoids’ (also called as mini-‘human brains’, referring to three-dimensional cultures of functional neuronal tissues derived from induced human pluripotent stem cells (iPSCs)) has made the translational research possible (5), and this would eventually lead to discoveries of genuine novel therapeutic targets against neurodegenerative disorders and cerebral ischemia.
This exciting but challenging project will utilise the established ‘organoids’ technology in collaboration with Sheffield Centre for Stem Cell Biology (https://www.sheffield.ac.uk/cscb), to study the roles of protein SUMOylation in cerebral organoids upon directed-differentiation towards neuronal tissues (to mimic human brain development) and under different stresses (to mimic diseased conditions). The proposed work will be conducted using a combination of techniques including molecular biology (e.g., CRISPR/Cas9 genome editing), protein chemistry (e.g., SUMOylation assays), cell culture (e.g., iPSCs), and analysis of changes in cell/tissue morphology/histology/ electrophysiology and protein aggregation as well as cell viability (e.g., confocal analysis of mitochondrial morphology, cytochrome c release, caspase activation, MTT, LDH assays etc).
Science Graduate School
As a PhD student in one of the science departments at the University of Sheffield, you’ll be part of the Science Graduate School. You’ll get access to training opportunities designed to support your career development by helping you gain professional skills that are essential in all areas of science. You’ll be able to learn how to recognise good research and research behaviour, improve your communication abilities and experience the breadth of technologies that are used in academia, industry and many related careers. Visit www.sheffield.ac.uk/sgs to learn more.
1 Henley, J. M., Carmichael, R. E. & Wilkinson, K. A. Extranuclear SUMOylation in Neurons. Trends in neurosciences 41, 198-210, doi:10.1016/j.tins.2018.02.004 (2018).
2 Henley, J. M., Craig, T. J. & Wilkinson, K. A. Neuronal SUMOylation: mechanisms, physiology, and roles in neuronal dysfunction. Physiological reviews 94, 1249-1285, doi:10.1152/physrev.00008.2014 (2014).
3 Anderson, D. B., Zanella, C. A., Henley, J. M. & Cimarosti, H. Sumoylation: Implications for Neurodegenerative Diseases. Advances in experimental medicine and biology 963, 261-281, doi:10.1007/978-3-319-50044-7_16 (2017).
4 Guo, C., Hildick, K. L., Luo, J., Dearden, L., Wilkinson, K. A. & Henley, J. M. SENP3-mediated deSUMOylation of dynamin-related protein 1 promotes cell death following ischaemia. The EMBO journal 32, 1514-1528, doi:10.1038/emboj.2013.65 (2013).
5 Pasca, A. M., Sloan, S. A., Clarke, L. E., Tian, Y., Makinson, C. D., Huber, N., Kim, C. H., Park, J. Y., O'Rourke, N. A., Nguyen, K. D., Smith, S. J., Huguenard, J. R., Geschwind, D. H., Barres, B. A. & Pasca, S. P. Functional cortical neurons and astrocytes from human pluripotent stem cells in 3D culture. Nature methods 12, 671-678, doi:10.1038/nmeth.3415 (2015).