Establishment and optimization of induced pluripotent stem cell technologies

• Main Author: Amir Morshedi
• Other Authors: Peter Droge
• Format: Theses and Dissertations
• Language: English
• Published: 2014
• Subjects: DRNTU::Science::Biological sciences::Molecular biology
• Online Access: https://hdl.handle.net/10356/55295
• Institution: Nanyang Technological University

Reprogramming of adult somatic cells into an embryonic stem cell (ESC) state by various transcription factors has been the start of a new era in the field of biomedical sciences. This finding has had tremendous impact on drug discovery and disease modeling and there is great hope for these cells to replenish body cells for therapy. An important aspect of this is the ability to monitor and acquire cells which are pluripotent, providing suitable cells for therapy. Undifferentiated transcription factor 1 (UTF1) belongs to the core transcriptional network regulating pluripotency and its expression pattern during cell reprogramming and subsequent differentiation appears to be tightly connected to the pluripotent state. Regarding these features we generated a reliable reporter for monitoring induced pluripotent stem cell (iPSC) formation and differentiation. Our construct indicated functionality both transiently or upon integration into the genome. Furthermore fluorescent iPSCs derived from mice carrying the construct indicated that this reporter is a feasible tool for biomedical research. Note that the small size of our cassette enables easy delivery by different means into the cell. In overall these characteristics qualify our reporter as a reliable reporter system to monitor iPSCs. We looked into the nonhistone chromatin factor called high mobility group AT-hook 2 (HMGA2) normally expressed in ESCs and during early developmental stages. Aberrant expression of this protein has shown to impact body stature, diabetes mellitus and heart development. Furthermore it plays an important role in cancer development and metastasis. Here we studied HMGA2’s role in iPSCs to better understand its function regarding pluripotency. Gene profiling of HMGA2 overexpressing iPSCs gave us insight into the biology of HMGA2 in these cells. Gene ontology analysis revealed that anatomical/Developmental processes are strongly affected by HMGA2 with cell adhesion and differentiation process coming next. Furthermore our data indicated that key diabetes susceptibility genes are affected by HMGA2, revealing interesting link to the Lin28/let-7 pathway regulating mammalian glucose metabolism. Our data support the model that HMGA2 is necessary for maintenance of the pluripotent state and its overexpression predisposes cells into specific lineages during differentiation.