Principal Supervisor: Dr Dan MaLink opens in a new window

Co-supervisor: Irundika Dias

PhD project title: Investigating the roles of endothelial cells in age-related myelin regeneration by using induced pluripotent stem cells

University of Registration: University of Aston

Project outline:

The United Nations General Assembly has declared 2021-2030 the Decade of Healthy Ageing. Age-related changes in myelin physiology may lead to myelin degeneration, which has been recently revealed to be associated with neurodegeneration. Myelin is characterized by a high proportion of lipids and formed by oligodendrocytes in the central nervous system (CNS), it plays an important role by ensuring rapid conduction and providing trophic support to the axons. Oligodendrocytes are renewed and regenerated from their progenitor cells (OPCs), the OPC-mediated myelin regeneration process is vital for myelin maintenance and regeneration, but this process is declines with ageing. Aged OPCs acquire the hallmarks of ageing cells, including altered metabolism and mitochondria function, oxidative stress and inflammation. Although there is a body of new evidence supporting the ‘rejuvenating’ approaches for promoting stem cell-mediated regeneration for myelin damage in aged animal models, more studies on the underlying mechanisms are needed for improving myelin homeostasis and integrity in healthy ageing. Endothelial cells (ECs) form a central component of the vasculature system which are crucial to brain function. Brain ECs play important roles in myelin development, maintenance and regeneration. EC-secreted soluble factors, including growth factors and inflammatory mediators, provide a niche supporting the activation and differentiation of neural stem/progenitor cells. The role of myelin-vascular interactions in ageing has been understudied. In this project we are aiming to elucidate whether human ECs actively contribute to CNS myelin regeneration in ageing.

The methods include using new but well-developed human induced pluripotent stem cell (iPSC) technology to produce ECs (iPSC-ECs) from adult human to build a platform in modelling EC interaction with OPC in ageing. We have successfully established a platform for efficiently generating ECs from iPSCs and demonstrated their beneficial effects in promoting myelin regeneration in young adults. The objectives include: 1, To set up the co-culture system of iPSC-ECs with aged OPCs. iPSC-EC lines will be differentiated from human iPSCs by the established method. Aged OPCs will be isolated from the aged mice by the breakthrough method (Reference 2) or/and induced from young OPSs by cellular senescence reagents. 2. To investigate the role of iPSC-EC on rejuvenating aged OPC by using the co-culture system. OPC survival, proliferation, migration and differentiation will be examined by immunocytochemistry and cell assays. The anti-ageing effects will also be assessed on the recovery of aged OPCs from senescence, especially on their dysfunctional metabolism, oxidative stress and inflammation. Furthermore, we will use RNA-sequencing technique to profile the gene expression in theses OPCs to identify the associated molecular pathways. 3. To assess the anti-ageing effects of iPSC-EC on myelin regeneration in ex-vivo model of organotypic brain-slices. Brain-slice culture maintains neuronal and glial cell populations in the 3D organisation. We will transplant the iPSC-ECs into rat brain slices which has been induced into senescence by cellular senescence reagents and assess the myelin protection and OPC lineage progressing during myelin repair, by immunohisto-labelling the myelin structure together with OPCs and oligodendrocytes. The targeted molecular pathways will also be examined in the oligodendrocyte linages cells. The student will benefit from engaging our group’s cutting-edge research and learning multi-disciplinary knowledge on neuroregeneration through stem cells to build up leadership in future biomedical career.

References:
1. Sams 2021 Oligodendrocytes in the Aging Brain. Neuronal Signaling. 2. Neumann et al 2019 Metformin Restores CNS Remyelination Capacity by Rejuvenating Aged Stem Cells. Cell Stem Cell.

 

BBSRC Strategic Research Priority: Sustainable Agriculture and Food - Animal Health and Welfare, Understanding the rules of life - Neuroscience and behaviour and Stem Cells, and Integrated understanding of health - Ageing, and Regenerative Biology.

Techniques that will be undertaken during the project:

• human iPSC cell culture and EC induction
• rodent primary glial cell culture and co-culture with iPSC-ECs
• rodent brain slice culture
• immunocytochemistry/immunohistochemistry
• fluorescence confocal imaging and quantification
• cell apoptosis assay (TUNEL)
• cellular oxidative stress and metabolism assays
• cell metabolism measurement (by seahorse analyser)
• RNA-seq
• qRT-PCR
• Western blot
  
  

Contact: Dr Dan MaLink opens in a new window