In Thy-1-selected cells, GDNF significantly induced migration compared to the control with no GDNF (p 0.05) (Figure 1b). cytoplasm of GS cells (c’). (d) GS cells expresses GFRA1 (red). The enlargement shows that the staining decorates the cell membrane of GS cells (d’). Nuclei are counterstained with Hoechst.(TIF) pone.0059431.s001.tif (4.3M) GUID:?7261503F-1CD3-4585-9078-BB9F79AA6B19 Figure S2: Characterization of MACS-selected Thy-1-positive cells. Germ cells were enzymatically isolated from adult testes and labeled with anti-Thy-1 antibody, and the cell fractions were obtained by MACS selection as previously described [17]. Aliquots of unselected cells were used as controls. (a) Thy-1-positive cells were spun on a slide immunostained for PLZF (red), a marker of undifferentiated spermatogonia. Nuclei were stained with Hoechst. (b) Left: representative pictures of testis transplanted with unselected or Thy-1-positive cells at two months from transplantation; right: the histogram shows number of donor-derived colonies generated by transplantation of unselected or Thy-1-positive cells (n?=?3), *p 0.001 (b) Gene expression analysis by semi-quantitative RT-PCR. Reactions were performed in parallel for each gene. The amount of specific cDNA was normalized to -actin levels. The data (n?=?3) are presented as the fold increase versus control (unselected cells), * p 0.001. Thy-1-selected cells are significantly enriched in GFRA1 expressing cells, as well as for other SSC markers.(TIF) pone.0059431.s002.tif (1.5M) GUID:?172CA05B-A050-4397-94E2-9C223CF7DCFD Abstract In mammals, the biological activity of the stem/progenitor compartment sustains production of mature gametes through spermatogenesis. Spermatogonial stem cells and their progeny belong to the class of undifferentiated spermatogonia, a germ cell populace found on the basal membrane of the seminiferous tubules. A large body of evidence has exhibited that glial cell line-derived neurotrophic factor (GDNF), a Sertoli-derived factor, is essential for in vivo and in vitro stem cell self-renewal. However, the mechanisms underlying this activity are not completely comprehended. In this study, we show that GDNF induces dose-dependent directional migration of freshly selected undifferentiated spermatogonia, as well as germline stem cells in culture, using a Boyden chamber assay. GDNF-induced migration is dependent around the expression of the GDNF co-receptor GFRA1, as shown by migration assays performed on parental and GFRA1-transduced GC-1 spermatogonial cell lines. We found that the actin regulatory protein vasodilator-stimulated phosphoprotein (VASP) is usually specifically expressed in undifferentiated spermatogonia. VASP belongs to the ENA/VASP family of proteins implicated in actin-dependent processes, such as fibroblast migration, axon guidance, and cell adhesion. In intact seminiferous tubules and germline stem cell cultures, GDNF treatment up-regulates VASP in a dose-dependent fashion. These data identify a novel role for the niche-derived factor GDNF, and they suggest that GDNF may impinge around the stem/progenitor compartment, affecting the actin cytoskeleton and cell migration. Introduction A paradigm Rabbit polyclonal to KATNAL1 of the adult unipotent stem cell is the spermatogonial stem cell (SSC), which sustains the daily production of millions of mature sperm throughout the male adult life through spermatogenesis. SSCs belong to a class of spermatogonia defined as undifferentiated type A spermatogonia, a hallmark of which is usually their common nuclear morphology and the expression of markers such as PLZF, neurogenin3, E-cadherin, Lin-28, and GFRA1 [1]; [2]. Spermatogenesis is usually FASN-IN-2 a cyclic process that in the mouse is usually divided into 12 stages (I-XII), each stage representing a unique association of germ cells at different actions of differentiation. The relationship between the spermatogenic stages and the kinetics of proliferation and differentiation of the spermatogonia have been analyzed in different mammalian species [2]. In all the stages, undifferentiated spermatogonia can be found as single cells (type Asingle, As) or as interconnected chains of cells composed by two (defined as Apaired: Apr) up to 32 undifferentiated spermatogonia (defined as Aaligned: Aal). Subsequently, during stages VII and VIII of the cycle, almost all of the larger chains (Aal4CAal32) differentiate into A1 spermatogonia. In mammals, spermatogonia are located in the basal region of the seminiferous FASN-IN-2 tubules, in contact with the Sertoli cells and basement membrane that individual them from the peritubular myoid cells. Interestingly, spermatogonia are not immotile, they change their relative position. Migration of undifferentiated spermatogonia was first suggested by detailed morphological analysis of the topography of spermatogonia in the mouse testis [3]. More recently, this conclusion was supported by a time-lapse analysis of GFP-labeled undifferentiated spermatogonia that were tracked in vivo for several days and were found to migrate over the basal lamina [4]; [5]. Migration of undifferentiated spermatogonia could make sure even distribution of germ cell progeny over the basal compartment of the seminiferous tubules [3] or may be essential to keeping stem or progenitor cells in the right environment to ensure the self-renewal of the SSCs [6]. Cell migration may be arbitrary or directed toward a chemoattractant gradient. Direct migration, or chemotaxis, can be triggered by extracellular ligands that bind to cell surface area receptors, which procedure can result in reorganization from FASN-IN-2 the myosin and actin.
