CASP9 and infection: We further detected effect of MO infection on intrinsic apoptosis pathways in MH-S cells and found that MO infection activated mitochondria-mediated intrinsic apoptotic pathways, as demonstrated by increased p53 mRNA levels in a time-dependent manner (Figure 6a), upregulated p53 and Bax expression downregulated Bcl-2 expression (Figure 6b), and growing transcriptional levels of genes downstream of p53, including Bax, caspase-9, caspase-3, and AIF, with that accompany of declined mRNA levels of antiapoptotic Bcl-2 (Figure 6e).