Semaphorin-3A and its receptor neuropilin-1 are predominantly expressed in endothelial cells along the rostral migratory stream of young and adult mice

Abstract

In the adult brain, neuroblasts originating in the subventricular zone migrate through the rostral migratory stream to the olfactory bulb. While migrating, neuroblasts undergo progressive differentiation until reaching their final locations and fates. Because molecules involved in migration may also exert differentiating effects on young neurons, the identification of factors that support migration could also shed light on the processes of adult neuroblast differentiation. This is the case for members of the family of semaphorins and of its cognate receptors, the neuropilins. Here, we have evaluated the presence of semaphorin-3A and of its receptor neuropilin-1 along the rostral migratory stream in young and adult mice by using immunocytochemical, histochemical, and in situ hybridization techniques. Our morphological studies show that semaphorin-3A and neuropilin-1 are both mainly expressed on endothelial cells along the rostral migratory stream during postnatal development. Our results suggest that endothelial cells constitute the primary source and target of semaphorin-3A along the rostral migratory stream. Moreover, the present work outlines the potential role of blood vessels on neuroblast migration in the postnatal rostral migratory stream.

The path from the choroid plexus to the subventricular zone: go with the flow!

“…Several semaphorin family members and slits 1, 2, and 3 are expressed (Marques et al, 2011) and secreted by the CP (Hu, 1999; Sawamoto et al, 2006). Semaphorin signaling is usually associated with endothelial cells (Tamagnone and Mazzone, 2011); semaphorin-3a and its respective receptor are highly expressed in the endothelial cells that are present along the RMS (Meléndez-Herrera et al, 2008), suggesting a role for semaphorin-3a in the migration of neuroblasts. Whether semaphorins specifically secreted by the CP influence the migration of neuroblasts toward the olfactory bulb has not been determined.…”

Gap junctions are involved in cell migration in the early postnatal subventricular zone

“…This long distance migration throughout the anterior portion of the subventricular zone (SVZ) constitutes the rostral migratory stream (RMS) and is presently subject to extensive investigation (Angot et al, 2008;Garzotto et al, 2008;Meléndez-Herrera et al, 2008), specially due to its potential relevance to central nervous system plasticity and regeneration (Parent et al, 2002;Romanko et al, 2004).…”

Dynamic imaging reveals that brain-derived neurotrophic factor can independently regulate motility and direction of neuroblasts within the rostral migratory stream

“…Studies have shown that the vascular network within the RMS may act as a source of molecular factors (Leventhal et al, 1999, Snapyan et al, 2009), and as a scaffold for migration (Whitman et al, 2009). Many molecular signals influencing RMS migration have been identified, including slits (Wu et al, 1999, Nguyen-Ba-Charvet et al, 2004), semaphorins (Ito et al, 2008, Melendez-Herrera et al, 2008), netrins (Hamasaki et al, 2001, Murase and Horwitz, 2002), ephrins (Conover et al, 2000), and growth factors (Paratcha et al, 2006, Chiaramello et al, 2007, Garzotto et al, 2008). However, it is not clear where all these signals originate, how they relate to one another, or whether they distinctly modulate direction or motility.…”