Developing exogenous sources of vascular regeneration Theme 2 is developing proangiogenic cellular products starting from human (h) pluripotent stem cells (SC): prevalently embryonic stem cells (ESC), but also induced pluripotent stem cells (iPSC). We develop new RNA biology knowledge and apply it to improve the process of endothelial differentiation of SC. We are also expanding the understanding of extracellular vesicles, especially exosomes, released by SCs and their importance in modulating the paracrine activity of the cells. Exosomes represent a promising option for acellular regenerative medicine. Pluripotent stem cells offer the possibility for controlled differentiation and purification into vascular (progenitor) cells, with scale-up capability and refinement of cell content. We have developed clinical compatible protocols to produce proangiogenic endothelial cells(ECs) from hESC and demonstrated their therapeutic potential in acute and chronic limb ischaemia models in immune-deficient and immune-competent mice, including in mouse models of Type 2 diabetes. We also provide evidence that non-coding (nc) RNA, particularly long ncRNA (IncRNA), contribute to mesodermal and endothelial commitment and are instrumental to the specification of endothelial arterial versus venous identity. We are also interested in exogenous modulation of therapeutic lympho-angiogenesis. Lympho-angiogenesis is emerging as important for post-myocardial infarction recovery because it reduces myocardial oedema and favours the clearance of inflammatory cells, thus potentially reducing scarring. During development, lymphatic endothelial cells arise in part from venous ECs and in part from haemoangioblasts and hESC can be differentiated to lymphatic ECs. We are using our hESC systems to target post-myocardial infarction neovascularisation and evoke selective specification to arterial ECs and lymphatic ECs to improve our knowledge of this complex process and further refine the exogenous regenerative therapeutic approach. Available proteomics datasets from primary ECs (lymphatic and arterial) will be used for comparison to enable a comprehensive, unbiased read-out at the protein level rather than rely on selected marker proteins. Recent evidence has accumulated that extracellular vesicles, particularly exosomes, are key contributors of paracrine factors, driving proangiogenic activities by vascular progenitor cells in the ischaemic heart. Our main aims are to: Investigate the therapeutic potential of established hESCs in rodent myocardial infarction. Promote arterial and lymphatic specification of hESC-ECs and assess the impact of transplanted hESC-derived arterial EC and hESC-derived lymphatic ECs in post-MI vascular regeneration Investigate the contribution of exosomes to the therapeutic responses to hESC-EC Engineer endogenous and synthetic exosomes to develop them in off-the-shelf therapeutics able to induce vascular regeneration in the setting of myocardial infarction. Principal investigators Costanza Emanueli (Lead), Andrew Baker, Neil Henderson, Manuel Mayr, Gabor Foldes This article was published on 2024-03-19
