Novel Genetic Circuit for the Differentiation of Pluripotent Stem Cells into Megakaryocytes The lineage of all cell types begins with pluripotent stem cells. Pluripotent stem cells may differentiate into hematopoietic stem cells (HSC), which is the start of the blood cell lineage. One of the types of blood cells that derives from HSCs are megakaryocytes (MKs), from which platelets are derived. Platelets are anucleate cells that have important roles in clot formation and inflammation. This makes platelets an ideal vehicle for therapy, as none of the genetic engineering that is done to the precursor stem cells is transmitted to the engineered platelet product. By controlling iPSC differentiation, we can modify MKs to produce engineered platelets.
The aim of this project was to design and build a novel genetic circuit that directs mouse embryonic stem (ES) cells to differentiate into megakaryocytes (MKs). The genetic circuit was created by first amplifying the gene for HoxB4, a transcription factor, using PCR. The desired band of the amplified HoxB4 gene was inserted into a DNA vector containing Gata-1 through cloning. The genetic circuit controls the expression of HoxB4 and Gata-1 according to the cell state, allowing control of the cell's differentiation.
The genetic circuit has not been successful, due to incorrect enzyme cutting and failed ligation. Success in the integration of a novel circuit into stem cells would allow for better understanding of how to direct stem cell differentiation, and therefore cell function. This leads to the ability to modify MKs to produce engineered platelets to sense or diagnose thrombosis.