Next, we examined the protein expression of apoptosis-related proteins and found that proapoptotic-cleaved caspase-3, Bax, and Beclin expressions were increased after S. typhimurium and S. aureus infection at 3 and 6 h; in contrast, the protein expression of Bcl-2, an anti-apoptotic protein, was decreased upon bacterial infection. Here, CASP3 is linked to bacterial infectious disease.