mESC-based in vitro differentiation models to study vascular response and functionality following genotoxic insults

Area of Science:

• Cell Biology
• Toxicology
• Genetics

Background:

• Vascular endothelial cells (EC) require robust defense mechanisms against systemic damage.
• Embryonic stem cell (ESC)-based in vitro models are crucial for toxicological drug assessments.
• Understanding DNA damage response (DDR) in vascular cells is essential for maintaining vascular health.

Purpose of the Study:

• To differentiate mouse ESCs (mESCs) into functional EC and smooth muscle cells (SMC).
• To comparatively analyze DNA repair and DDR characteristics in mESCs, EC, and SMC.
• To investigate the impact of differentiation on cellular defense mechanisms.

Main Methods:

• Differentiation of mESCs into EC and SMC.
• Comparative analysis of DNA repair and DDR pathways (e.g., DSB repair, NER, BER, apoptosis, autophagy).
• Assessment of DNA double-strand break (DSB) formation and repair using γH2AX foci after IR exposure.
• Analysis of key DDR signaling proteins (p53, Chk1, Kap1) phosphorylation.

Main Results:

• Differentiation altered DDR and DNA repair profiles: downregulation of cell cycle/DSB/mismatch repair genes, upregulation of NER/apoptosis/autophagy genes.
• SMC showed low base excision repair (BER) gene expression.
• IR-induced DSB formation was most efficient in SMC, while repair was fastest in EC.
• IR exposure did not impair differentiation of vascular progenitors.

Conclusions:

• Vascular cell differentiation from mESCs involves significant, complex changes in DDR capacity.
• mESC-based vascular differentiation models provide insights into environmental stressor effects on vascular cells.
• These models are valuable for toxicological studies and understanding vascular health maintenance.