Seamless Insertion of a Granulin Gene Mutation (IVS0+5G>C) in Human Embryonic Stem Cells
Frontotemporal dementia (FTD) is the second most common form of presenile dementia. Mutations
in Granulin (GRN) gene which encodes Progranulin (PGRN) is known to be the most common
cause of this disease. However the mechanism by which PGRN haploinsufficiency causes the
disease. Human embryonic stem cells (hESCS) and patient’s derived induced pluripotent stem cells
(iPSCs) are potent tools for modeling human diseases. However lack of isogenic cell lines may
result in imprecise interpretation of the results due to genetic background variation between cell
lines. Seamless gene editing is an appropriate approach to provide isogenic cell lines.
In this work we produced the required tools for seamless genetic modification of both hESCs
and FTD patient’s derived iPSCs in order to develop isogenic cell lines by either introducing or
correcting the IVS0+5G>C GRN mutation, respectively. By using these tools seamless insertion of
the mutation in hESCs was performed successfully. The generated H9 cell line (H9IVS5+G>C) and its
wild type (WT) isogenic counterpart (H9wt) differ only in one base. As a result any differences
which will be observed between these two cell lines is the consequence of the inserted GRN mutation.
In addition, our designed approach is an efficient tool widely applicable for inserting or correcting
the mutations without any scars which seems promising for cell based therapeutic purposes.