Methylene Blue-Mediated Photodynamic Therapy Induces Macrophage Apoptosis via ROS and Reduces Bone Resorption in Periodontitis

Figure 2

Mitochondrial ROS burst and MMP loss in THP-1 macrophages induced by MB-PDT. (a) Fluorescent photomicrographs of THP-1 macrophages stained with DCFH-DA and MitoSOX depicting increases in intracellular and mitochondrial ROS. The results are expressed as the mean fluorescence intensity of macrophages. (b) Fluorescent photomicrographs of THP-1 macrophages stained with JC-1 to depict the MMP. The results are expressed as the relative mitochondrial membrane potential. (c, d) Cell viability was assessed at 24 h in THP-1 macrophages treated with 20 mM GSH for 1 h, followed by treatment with MB-PDT. The results are expressed as the percentage of viable cells compared with medium alone-treated or MB alone-treated controls (, ). (e) Apoptosis was assessed at 6 h in THP-1 macrophages treated with 20 mM GSH for 1 h, followed by treatment with MB-PDT. The results are expressed as the percentage of apoptotic cells. , , and . . Abbreviations: MB-PDT: methylene blue-mediated photodynamic therapy; DCFH-DA: 2-7-dichlorofluorescein diacetate.

(a)

(b)

(c)

(d)

(e)