Prss56, a novel marker of adult neurogenesis in the mouse brain

Abstract

Adult neurogenesis in the mammalian brain is restricted to specific regions, such as the dentate gyrus (DG) in the hippocampus and the subventricular zone (SVZ) in the walls of the lateral ventricles. Here, we used a mouse line carrying a knock-in of Cre recombinase in the Prss56 gene, in combination with two Cre-inducible fluorescent reporters (Rosa26 and Rosa26 ), to perform genetic tracing of Prss56-expressing cells in the adult brain. We found reporter-positive cells in three neurogenic niches: the DG, the SVZ and the hypothalamus ventricular zone. In the prospective DG, Prss56 is expressed during embryogenesis in a subpopulation of radial glia. The pattern of migration and differentiation of reporter-positive cells during development recapitulates the successive steps of DG neurogenesis, including the formation of a subpopulation of adult neural stem cells (NSC). In the SVZ, Prss56 is expressed postnatally in a subpopulation of adult NSC mainly localized in the medial-ventral region of the lateral wall. This subpopulation preferentially gives rise to deep granule and Calbindin-positive periglomerular interneurons in the olfactory bulb. Finally, Prss56 is also expressed in a subpopulation of α2-tanycytes, which are potential adult NSCs of the hypothalamus ventricular zone. Our observations suggest that some α2-tanycytes translocate their soma into the parenchyma and may give rise to a novel cell type in this territory. Overall, this study establishes the Prss56 line as an efficient and promising new tool to study multiple aspects of adult neurogenesis in the mouse.

Prss56 expression in the rodent hypothalamus: Inverse correlation with pro‐opiomelanocortin suggests oscillatory gene expression in adult rat tanycytes

“…The presence of γ tanycytes was also demonstrated in the mouse median eminence (Miranda‐Angulo, Byerly, Mesa, Wang, & Blackshaw, ). Tanycyte‐like cells in the arcuate nucleus parenchyma were described by Jourdon et al () as cells having tanycyte‐like processes, elongated morphology and positive for genes characteristic of tanycytes including vimentin, nestin, and Sox2. They demonstrated that at least some of these cells are Prss56 ‐expressing α2 tanycytes that migrated into the parenchyma (Jourdon et al, ).…”

“…While such obvious clues were not found, we came upon a unique expression pattern, that of Prss56 , a trypsin‐like serine protease (Nair et al, ), which is expressed specifically in neural stem/progenitor cells in the adult and embryonic mouse brain, including tanycytes (Jourdon et al, ). Reporter expression in Prss56 Cre/+ , Rosa26 tdTom/+ mice labels tanycytes, but only a fraction of them in a seemingly random distribution, as well as tanycyte‐like cells in the hypothalamic parenchyma that appear to be former tanycytes that translocated their soma into the parenchyma (Jourdon et al, ). Based on this unusual pattern, we hypothesized that Prss56 is expressed transiently in mouse tanycytes, and therefore, a potential candidate for a variably expressed gene that correlates with Pomc in rat tanycytes.…”

Hypothalamic Neurogenesis as an Adaptive Metabolic Mechanism

“…In lineage-tracing experiments using a Cre/lox system in which recombinase were expressed in tanycytes under the control of promoters, such as nestin (Lee and Blackshaw, 2012), glast (Robins et al, 2013), fgf10 (Haan et al, 2013), and prss56 (Jourdon et al, 2015), their role as neural stem cells was confirmed. In these transgenic mice, the constitutive expression of a reporter gene facilitates tanycyte tracking over time.…”

Are Tanycytes the Missing Link Between Type 2 Diabetes and Alzheimer’s Disease?

“…Notably, although specific marker genes (or combinations of marker genes) are used to roughly separate tanycyte subtypes, many genes exhibit a gradient, rather than a clear-cut distribution across tanycyte subpopulations which are consistent with the notion that tanycytes may be composed of continuous cell trajectory with transition zones between different subtypes. Recently two new markers UGS148 and Prss56 have been identified and found to be enriched in tanycytes [18,19]. …”