title: Macrophage and microglia ontogeny in the mouse visual system can be traced by the expression of Cathepsins B and D.
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.
authors.affiliation: Departamento de Biología Celular, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain.
authors.forename: Ruth
authors.initials: R
authors.lastname: Bejarano-Escobar
authors.forename: María Salud
authors.initials: MS
authors.lastname: Holguín-Arévalo
authors.forename: Juan Antonio
authors.initials: JA
authors.lastname: Montero
authors.forename: Javier
authors.initials: J
authors.lastname: Francisco-Morcillo
authors.forename: Gervasio
authors.initials: G
authors.lastname: Martín-Partido
mesh_terms: D000818:Animals; D002401:Cathepsin B / Q000235:genetics / Q000378:metabolism*; D002402:Cathepsin D / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism; D005260:Female; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D020287:In Situ Nick-End Labeling; D008264:Macrophages / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D017628:Microglia / Q000166:cytology / Q000378:metabolism*; D011247:Pregnancy
chemical_list: D002401:Cathepsin B; D002402:Cathepsin D