Noninvasive Quantification of Retinal Microglia Using Widefield Autofluorescence Imaging

作者:Kokona Despina; Schneider Nadia; Giannakaki Zimmermann Helena; Jovanovic Joel; Ebneter Andreas; Zinkernagel Martin*
来源:Investigative Ophthalmology & Visual Science, 2017, 58(4): 2160-2165.
DOI:10.1167/iovs.16-20916

摘要

PURPOSE. To validate widefield autofluorescence (AF) in vivo imaging of the retina in mice expressing green fluorescent protein (gfp) in microglia, and to monitor retinal microglia reconstitution in vivo after lethal irradiation and bone marrow transplantation. METHODS. Transgenic Cx3cr1gfp/gfp and wildtype Balb/c mice were used in this study. A confocal scanning laser ophthalmoscope was used for AF imaging with a 558 and a widefield 1028 lens. Intrasession reproducibility was assessed for each lens. To investigate reconstitution in vivo, bone marrow from Cx3cr1gfp/gfp mice was used to rescue lethally irradiated wildtype mice. Data were compared to confocal microscopy of retinal flat mounts. RESULTS. Both the 558 and the 1028 lens produced high resolution images of retinal microglia with similar microglia density. However, compared to the 558 lens, the widefield 1028 lens captured approximately 3.6 times more microglia cells (1515 +/- 123 cells versus 445 +/- 76 cells [mean +/- SD], for 102 degrees and 55 degrees, respectively, P < 0.001). No statistical difference in the number of gfp positive cells within corresponding areas was observed within the same imaging session. Imaging of microglia reconstitution showed a similar time course compared to flat mount preparations with an excellent correlation between microglia cell numbers in AF and gfp-stained flat mounts (R = 0.92, P < 0.0001). CONCLUSIONS. Widefield AF imaging of mice with gfp expressing microglia can be used to quantify retinal microglia. In vivo microglia counts corresponded very well with ex vivo counts on retinal flat mounts. As such, AF imaging can largely replace ex vivo quantification.

  • 出版日期2017-4