Macrophage and microglia ontogeny in the mouse visual system can be traced by the expression of Cathepsins B and D

Authors

  • Ruth Bejarano-Escobar,

    1. Departamento de Biología Celular, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain
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  • María Salud Holguín-Arévalo,

    1. Departamento de Biología Celular, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain
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  • Juan Antonio Montero,

    1. Departamento de Anatomía y Biología Celular, Facultad de Medicina, Universidad de Cantabria/IFIMAV, Santander, Spain
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  • Javier Francisco-Morcillo,

    1. Departamento de Biología Celular, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain
    2. Departamento de Biología Celular, Facultad de Veterinaria, Universidad de Extremadura, Cáceres, Spain
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  • Gervasio Martín-Partido

    Corresponding author
    1. Departamento de Biología Celular, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain
    • Departamento de Biología Celular, Facultad de Ciencias, Universidad de Extremadura, Avda. de Elvas s/n, 06006 Badajoz, Spain
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Abstract

Here, we show a detailed chronotopographical analysis of cathepsin B and D expression during development of the mouse visual system. Both proteases were detected in large rounded/ameboid cells usually located in close relationship with prominent sites of extensive physiological cell death. In concordance with their morphological features and topographical distribution, we demonstrate that expressing cells corresponded with macrophages and microglial precursors. We found that as microglial precursors differentiated the expression of both cathepsins was down-regulated. Of interest, cathepsin B and D transcripts were never observed in degenerating cells. Our findings point to a role for cathepsin D and B in cell debris degradation after apoptotic processes rather than promoting cell death, as proposed for other developmental models. Additionally their pattern of expression suggests a role in the maturation of the microglial precursors. Developmental Dynamics 240:1841–1855, 2011. © 2011 Wiley-Liss, Inc.

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