Figure 7. Effect of enzymatic digestion on the expression of ECM and adhesion and the resistance to oxidative stress.

A) Western blotting shows that the dissociation of cardiospheres into single cell suspension decreased the expression of integrin-α₂ and laminin-β₁. B) Representative images (upper images) show the TUNEL-positive (red) cardiac-derived cells under cardiosphere and monolayer culture conditions with 24 hrs exposure to 100 μM H₂O₂. Although the number of apoptotic cells (lower bar graph) was lower in cardiospheres than monolayer-cultured cells with 24 hrs exposure to 100 μM H₂O₂, the resistance to oxidative stress in cardiospheres was negated by dissociating the cardiospheres into single cells. (Diss-Mono: dissociated monolayer-cultured cells by 5 minutes trypsin digestion; Mono: twice-passaged CDCs under monolayer culture; Diss-CSp: dissociated cardiospheres by 30 minutes trypsin digestion; CSp: cardiospheres formed from twice-passaged CDCs.).