Periodic Reporting for period 4 - StemHealth (Foetal Intestinal Stem Cells in Biology and Health) Período documentado: 2021-02-01 hasta 2022-07-31 Resumen del contexto y de los objetivos generales del proyecto IBD is a chronic condition without a medical cure, and patients with IBD disease require a lifetime of care. The prevalence of IBD is currently highest in the Western world and affects 2.5-3.0 million patients in Europe, with an estimated annual cost for European health systems in excess of €5.0bn excluding the added socioeconomic burden. The current standard of care involves immunomodulatory drugs either alone or in combination with biologics such as inhibitors of specific signalling pathways. Due to failure of the palliative care, many IBD patients will have to undergo bowel resection and subsequently deal with the physiological and psychological complications related to a life without parts of the small or large intestine. To decrease the large socio-economic burden, alternative treatment strategies are required. We propose that IBD patients will benefit from epithelial transplants initially in combination with immunosuppressive therapies, or alternative strategies for promoting mucosal healing based on activation of endogenous stem cells. This requires the availability of an appropriate and sustainable source of cells for autologous transplantation, as well as better insight in the intestinal epithelium. Notably, the development of cell culture methods for primary epithelial cells from human small intestine and colon and the encouraging transplantation results from rodents bring promise to this approach.The objective of the proposed research programme has been twofold. Firstly, we aimed to characterise and investigate the suitability of current sources of epithelial intestinal stem cells for transplantation. Secondly, we wished to define the transcriptional regulatory networks that control the differences observed between an immature foetal state and its adult state in the intestinal epithelium.Via support from the European Research Council, we have been able to make significant progress towards the identified objectives. Most notably, we have utilized insight into how normal tissue regeneration proceeds using experimental animal models and in patient samples. This has enabled us to direct intestinal epithelial cells isolated from the adult epithelium into a fetal state both via genetically manipulating the cells and via using clinically compliant cell culture components. Importantly, cells in this fetal state efficiently engraft into an injured intestine. Importantly, we went on to show that epithelial cells in this fetal state were inherently more potent than cells in the adult state explaining both why they emerge during tissue regeneration and why these cells efficiently engraft upon transplantation. Collectively, we believe that this insight is critical and will have significant potential for moving cellular therapies into the clinic. Trabajo realizado desde el comienzo del proyecto hasta el final del período abarcado por el informe y los principales resultados hasta la fecha Using state of the art methodology, we have tackled the key questions posed in the original application. We set out to identify genes that would control whether fetal cells mature and become adult cells, and genes that safeguard that adult cells in the intestinal epithelium revert back to a fetal state. During this process we characterized the epithelium following severe injury and observed that during tissue regeneration epithelial cells transition from an adult state into a state expressing markers normally associated with the fetal intestine. Our analyses revealed that changes in the environment was responsible for the observed ‘de-maturation’ of adult homeostatic intestinal epithelial stem cells into this a more primitive state. Moreover, this was directed via the transcriptional regulators YAP and TAZ. Moreover, dematuration could be promoted using non-genetic approaches simply utilizing clinical grade extracellular matrix molecules most abundantly detected during tissue regeneration. This was published in a highly-cited paper in Cell Stem Cell in 2018 (PMID: 29249464). The identification of YAP as a reprogramming factor during natural tissue remodelling has strong clinical implications. Firstly, it now provides a tool for modulating cellular identity an aspect that could potentially be exploited to enhance endogenous tissue repair, and secondly, epithelial cells can be grown in this state utilizing clinically compliant materials thereby bypassing the requirements for using animal derived Matrigel and enabling the development of future cellular therapies.Building upon these seminal findings we demonstrated that the same signaling pathways operate during fetal development (PMID: 35132078) and correlated with the presence of highly potent fetal cell populations that similar to cells responsible for rebuilding the tissues following damage were responsible for growing the tissue during development (PMID: 31092921). The presence of highly potent fetal progenitors was not unique to the intestinal epithelium as quantitative analysis of cells in both the intestine and epidermis revealed their existence, thereby demonstrating that this is most likely a phenomenon shared across tissues (PMID: 31092921 and 31358966). Interestingly, the identified pathways activated via the environment were also exploited during early cancer development, where cells utilized these signaling systems to bypass natural signals that would otherwise induce terminal differentiation (PMID: 36037993).As a key tool for assessing cell fate and cellular potential we have over the period of the action supported by the European Research Council and aligned with the objectives of the research program optimized protocols for performing transplantation experiments using various animal models. This has been essential for drawing key conclusions related to the utility of new culture conditions (PMID: 29249464), general cellular potential (PMID: 31092921) and in diseases such as tumor development (PMID: 36037993). It is however important to ascertain that such a key methodology was highly reproducible across different research groups. We have therefore published a detailed protocol describing the key parameters for successful transplantation to the colonic epithelium (PMID: 35110738). This is essential for the downstream exploitation of the technology in addressing fundamental research questions, and also to pursue our plan to utilize the basic principles around the methodology to establish cellular therapies for patients with ulcerative colitis. Avances que van más allá del estado de la técnica e impacto potencial esperado (incluida la repercusión socioeconómica y las implicaciones sociales más amplias del proyecto hasta la fecha) The research program supported by the European Research Council has enabled us to address key questions in the field that had been left unanswered. This has been instrumental for providing new insight into the basic principles that governs regulatory mechanisms controlling cell fate decisions. Here quantitative state-of-the-art experimental strategies have been essential to move the field forward based on knowledge and not based on assumptions. We hope and believe that the principles we have discovered will enable us to move towards new therapies for patients with ulcerative conditions initially in the bowel, but potentially also to other parts of the body. Documentos relacionados Fetal_enterosphere.jpg
