About ITS
“Through the use of human and mouse cellular systems our lab aims to identify the signals and cell-cell interactions that underlie the integration of morphogenesis and cell differentiation during organogenesis. Based on the success of our multifaceted approach to research, we are establishing an international program for up-scaled manufacturing of human pluripotent stem cell-derived pancreatic islet-like clusters for clinical testing in type-1 diabetes patients.” Prof. H. Semb
“Through the use of human and mouse cellular systems our lab aims to identify the signals and cell-cell interactions that underlie the integration of morphogenesis and cell differentiation during organogenesis. Based on the success of our multifaceted approach to research, we are establishing an international program for up-scaled manufacturing of human pluripotent stem cell-derived pancreatic islet-like clusters for clinical testing in type-1 diabetes patients.” Prof. H. Semb
Our Research Focus
Research Themes and Questions
The developing pancreas undergoes complex and intriguing epithelial cell rearrangements. The gross morphology of the organ changes from an epithelial sheet to an epithelial bud and finally to a branched/tubular epithelial tree. In parallel, pancreatic progenitors differentiate into multiple cell types and elicit major changes in cell organization including; microlumen and tube formation, acinus formation at the tips of the tubes and islet formation via delamination and clustering of new-born endocrine cells. Whilst published descriptive studies provide a good basis for understanding the pancreatic niche we aim to refine this by studying architecture and cellular behaviours in a more dynamic manner;
- In human and mouse pancreatic epithelia – the latter provides a physiological reference point whilst the former allows for more direct analysis of the cells,
- With a temporal dimension (i.e. live cell imaging),
- In an unbiased quantitative manner use cell segmentation, in silico modelling, deep machine learning and artificial AI to identify novel cellular features involved in cell fate decisions.
Whilst it is apparent that apical polarity links gross morphology, cellular rearrangements ,and cell differentiation as the pancreas forms, the signals coordinating each step are yet to be elucidated. Our scientists are implementing projects using the techniques stated above to address the gaps in our knowledge.
Pancreatic tubes and islets provide niches for alpha and beta cell maturation but are in themselves a culmination of multiple dynamic cellular events. What cellular behaviors coordinate the formation of tubes and islets?
Our group has published an important observation that apical polarity cell autonomously affects the differentiation capacity of endocrine progenitors and is recapitulated in the differentiation of hESCs to endocrine cells in vitro. Yet, we still do not understand how apical proteins, in a previously non-polarised epithelium, are recruited to the membrane of a pancreatic epithelial cell and extend to neighbouring cells to form a plexus that is ultimately refined to a tubular network. Several projects in the lab are focusing on addressing these issues temporally both in vitro and ex vivo. In addition, we want to determine whether cell movement within the plane and from the epithelium is associated with changes in cellular phenotype and how these behaviours are initiated and coordinated. To fully appreciate how all these events are coordinated requires them to be visualized over time at single-cell resolution. Thus we are developing unique reporter lines in human (hESCs) and mouse model systems, including those that visualize apical membrane proteins and endocrine progenitors in parallel. To quantify our complex imaging datasets, we are developing novel tools to segment and track cells and tubular structures. We strengthen our work in this field through our collaborations with experts on explainable AI at the Janelia Research Campus, USA. It is also our aim to simulate and manipulate 4D cell behaviours in silico. Such computer models will enable us to ‘test’ many variables that could be attributed to specific cell behaviours, such as polarity expansion, cell movement, and cell shape changes, before testing our hypotheses empirically.
Does a cell’s niche provide distinct mechano-biological properties that instruct commitment to a specific endocrine fate?
Our lab recently found that signaling by the Egfr ligand, betacellulin, diminishes apico-basal polarity leading to upregulation of Ngn3, delamination, and beta cell differentiation, (Lof-Ohlin et al NCB 2017). Furthermore, we found that when Ngn3+ endocrine progenitors are forced to exit the primitive pancreatic ducts their commitment into different hormone+ endocrine cells change (Nyeng et al DevCell 2019). Our scientists are exploring the hypothesis that unique epithelial architectures instruct endocrine progenitors toward an alpha or beta cell lineage. We use hypothesis-driven and unbiased approaches to address this important question.
Does endocrinogenesis impact on epithelial morphogenesis?
In a separate project related to the theme that differentiation and morphogenesis are coordinated, we turn to an observation first published a decade ago that the disruption of endocrine differentiation also affects the patterning of the pancreas. This is a surprising result because in many other organs these processes are either independent or sequential. To understand exactly how differentiation can impact upon epithelial morphogenesis, we will perform a 4D analysis of luminal architecture in endocrine mouse mutants using time-lapse imaging. Taking advantage of the high yield of endocrine cells produced in hESC differentiation cultures we will further use machine learning to characterize novel differences between alpha and beta cells in these heterogeneous cultures.
Can we improve the yield and functional efficiency of insulin producing beta cells from hESCs?
The overarching aim of our lab is to utilize the knowledge we gain from basic research projects to facilitate the generation of high yields of beta cells for diabetes focused clinical applications. The translation of the findings to GMP grade differentiation cultures requires optimization of many aspects of the current protocols in a cost-effective manner, including;
- Develop protocols for up-scaled manufacturing of hESC-derived pancreatic beta cells.
- Improving the 3D culture system to parallel the 3D niche of an islet in which functional beta cells respond to glucose stimulation in vivo.
- Development of robust characterization methods that can routinely give an accurate prediction, in a quantitative manner, of the transplantation outcome of hESC derived islet-like clusters.
Only once the above steps have been optimized will we be able to progress phase 1 clinical trials that would assess the safety and efficacy of transplanting hESC-derived pancreatic islet-like clusters in humans.
Grants
- EU Horizon 2020-funded project “Advancing Innovative Stem Cell-based Therapy for Diabetes in Europe” (ISLET): https://isletproject.eu/
- BMBF-funded project eISLET “Engineered Pancreatic Islets for Cell Replacement Therapies”
- EU Horizon 2020-funded project “The European Consortium for Communicating Gene and Cell Therapy' aims to provide accessible and reliable information on cell- and gene-based therapies” (EuroGCT): https://www.eurogct.org/
Patents
The lab has filed for a number of innovative patent based on research from the Semb lab, including:
A total of 8 patents have been applied for and/or granted based on innovative research from the Semb lab. Of note are the following patents;
- technologies allowing isolation of pancreatic beta cell progenitors from hPSCs (Ameri et al 2017),
- new targets for controlling expansion of such progenitors (Ameri et al 2017),
- a novel approach to turn these progenitors into functional beta cells (Löf-Öhlin et al 2017; Mamidi, Prawiro et al, 2018).