Fig. 1

pSMAD and pTAK1 are localized to retinal microglia. Retinal sections from P30 mouse injected with vehicle or BMP7 24 h postinjection were double-labeled with antibodies that label microglial nuclei (PU.1) and phospho SMAD 1/5/9 (pSMAD; a–h) or phospho TAK1 (pTAK1; i–p). Thin plane confocal microscopy images with y,z (strips to right of the panel) and x,z planes (strips at the bottom of the panels) shown in (d), (h), (l), and (p). pSMAD-labeled cells were primarily found in the GCL in the vehicle-treated retina, with some colocalization with the nuclear microglial marker PU.1 (a–d). The BMP7-injected retina had an increase in pSMAD expression in the INL as well as substantial colocalization with PU.1 (e–h). In contrast, vehicle-injected retina showed pTAK1 expression in the GCL with little to no PU.1 colocalization (i–l), while the BMP7-injected retinas showed increased levels of pTAK1 levels in the INL, as well as significant colocalization with PU.1 (m–p). Magnification bar in a = 50 μm, for images (a–p)