A Snake Venom-Secreted Phospholipase A₂ Induces Foam Cell Formation Depending on the Activation of Factors Involved in Lipid Homeostasis

Figure 6

MT-III-induced LD formation and COX-2 protein expression in macrophages are dependent on CD36. (a) Peritoneal macrophages were incubated with SSO (25 μM) compound or vehicle (<1% DMSO/RPMI) for 30 min and then with MT-III (0.4 μM) for 12 h. LDs were quantified using light microscopy after osmium staining. Each bar represents the mean ± SEM LDs/cell in 50 counted cells. Values represent means ± SEM from 3–5 animals. compared with the control group; compared with vehicle-treated MT-III-stimulated cells. (b) Western blotting and densitometric analysis of CD36 and β-actin (loading control) in macrophage extracts. Peritoneal macrophages were incubated with MT-III (0.4 μM) or RPMI (control) for 6, 12, and 24 h. compared with controls; ^& compared with MT-III 6 h. (c) Western blotting and densitometric analysis of COX-2 and β-actin (loading control) in macrophage extracts pretreated with CD36 antagonist, SSO. compared with vehicle-treated MT-III- stimulated cells. Peritoneal macrophages were incubated with SSO (25 μM) compound or vehicle (<1% DMSO/RPMI) for 30 min and then with MT-III (0.4 μM) for 12 h. The densities (in arbitrary units) were normalized with those of β-actin. Results are expressed as mean ± SEM from three experiments. compared with controls.

(a)

(b)

(c)