Substrate stiffness effect and chromosome missegregation in hIPS cells

Area of Science:

• Stem Cell Biology
• Cellular Mechanics
• Genetics

Background:

• Genetic stability in pluripotent stem cells (PSCs) is critical for cell therapy development.
• Prolonged in vitro culture of PSCs can lead to genetic abnormalities.
• Non-physiological stiff substrates, like tissue culture polystyrene (TCPS), may influence these abnormalities.

Purpose of the Study:

• To investigate the impact of substrate mechanics on the genetic stability of human PSCs.
• To determine if substrate stiffness influences the rate of abnormal cell division in PSCs.

Main Methods:

• Human PSCs, including two induced PSC (iPSC) lines (19-9-11 and 19.7 clone F), were cultured on substrates with stiffness ranging from 5 kPa to 64 GPa.
• Substrates included polyacrylamide formulations, TCPS, and borosilicate glass.
• Centrosome and DNA staining were used to analyze mitosis.

Main Results:

• Abnormal mitosis rates in 19-9-11 iPSCs ranged from 1-8.5% across different culture conditions.
• Abnormal mitosis rates in 19.7 clone F iPSCs ranged from 4.4-8.1%.
• No bias towards a specific substrate was observed for abnormal cell division.

Conclusions:

• Statistical analysis (ANOVA and Tukey's HSD test) revealed no significant differences in abnormal cell division rates based on passage number, cell line, or substrate stiffness.
• Substrate mechanics do not appear to be a primary driver of genetic abnormalities in PSCs under the tested conditions.