Immunofluorescence staining of human arginine decarboxylase (hADC)-introduced astrocytes after oxygen-glucose deprivation (OGD). (A, D, G) No treatment control astrocytes; (B, E, H) astrocytes after 4 hrs OGD; (C, F, I) hADC-astrocytes after 4 hrs OGD. Cells reacted to inducible nitric oxide synthase (iNOS) (A-C), matrix metalloproteinase (MMP) 2 (D-F), and MMP 9 (G-I) showed green fluorescence. Cells were counter-stained with astrocyte marker glial fibrillary acidic protein (GFAP; red fluorescence) and nuclear marker 4',6-diamidino-2-phenylindole (DAPI; blue fluorescence). Scale bar = 50 μm.