Insertion/deletion and microsatellite alteration profiles in induced pluripotent stem cells

Area of Science:

• Genomics
• Stem Cell Biology
• Molecular Biology

Background:

• Microsatellite (MS) alterations are frequently observed in induced pluripotent stem cells (iPSCs), posing challenges for their genomic stability.
• Identifying iPSC lines with reduced genomic abnormalities is crucial for safe and effective therapeutic applications.

Purpose of the Study:

• To profile insertion-deletion mutations (InDels) within microsatellite regions in induced pluripotent stem cells (iPSCs) and normal tissue-derived ESCs (ntESCs).
• To develop and validate a method for detecting somatic de novo mutations in iPSCs using genetically identical sister clones.
• To identify human iPSC lines exhibiting a reduced burden of microsatellite alterations.

Main Methods:

• Generated 13 independent mouse stem cell lines (11 iPSCs, 2 ntESCs) from a single somatic cell fraction for comparative analysis.
• Utilized sister clone analysis to detect and experimentally validate clone-specific somatic de novo mutations.
• Applied the validated sister clone approach to analyze genomic alterations in human iPSCs.

Main Results:

• Demonstrated that microsatellite alterations are elevated in both mouse and human iPSCs.
• Successfully identified a specific type of human iPSC with considerably reduced microsatellite alterations.
• Validated the effectiveness of sister clone analysis for detecting somatic de novo mutations in stem cell genomes.

Conclusions:

• The study highlights the prevalence of microsatellite alterations in iPSCs but identifies a promising human iPSC subtype with improved genomic stability.
• The developed sister clone methodology provides a robust framework for detecting and validating somatic mutations in iPSCs.
• These findings represent a significant step towards addressing genomic abnormalities in iPSCs for future research and clinical use.