Fig. 11
High concentration of CO2 aggravates apoptosis of cultured neurons via hypoxia-activated microglia (n = 4). a, b The immunoreactive bands of Bcl-2 (26 kDa), Bax (20 kDa), caspase-3 (17 kDa), and GAPDH (36 kDa). c–e There are significant interaction effects between CM + HC treatment and CM + hypoxia treatment (Bcl-2: P < 0.05; Bax: P < 0.05; caspase-3: P < 0.05). f Simple effects analyses show that the protein expression of Bcl-2, Bax, and caspase-3 in CM + HC group has no significant difference compared with CM group (ns P > 0.05). The protein expression levels of Bcl-2 in CM + hypoxia group are significantly decreased compared with CM group (**P < 0.01). CM + hypoxia + HC group has the lowest levels of the protein in comparison with CM + HC group (**P < 0.01) and CM + hypoxia group (**P < 0.01). In contrast, a significant increase in Bax and caspase-3 expression is observed in CM + hypoxia group compared with CM group (**P < 0.01). The levels of Bax and caspase-3 expression in CM + hypoxia + HC group is the highest as compared to CM + HC group (**P < 0.01) and CM + hypoxia group (**P < 0.01). When BV-2 conditioned medium is pretreated with Z-YVAD-FMK, the protein expression of caspase-3 of neurons is significantly suppressed (**P < 0.01). CM conditioned medium, HC high concentration of carbon dioxide, Z Z-YVAD-FMK