scholarly journals Distribution of Aldh1L1-CreERT2 Recombination in Astrocytes Versus Neural Stem Cells in the Neurogenic Niches of the Adult Mouse Brain

2021 ◽  
Vol 15 ◽  
Author(s):  
Felix Beyer ◽  
Wichard Lüdje ◽  
Julian Karpf ◽  
Gesine Saher ◽  
Ruth Beckervordersandforth

In the adult central nervous system, neural stem cells (NSCs) reside in two discrete niches: the subependymal zone (SEZ) of the lateral ventricle and the subgranular zone (SGZ) of the dentate gyrus (DG). Here, NSCs represent a population of highly specialized astrocytes that are able to proliferate and give rise to neuronal and glial progeny. This process, termed adult neurogenesis, is extrinsically regulated by other niche cells such as non-stem cell astrocytes. Studying these non-stem cell niche astrocytes and their role during adult neuro- and gliogenesis has been hampered by the lack of genetic tools to discriminate between transcriptionally similar NSCs and niche astrocytes. Recently, Aldh1L1 has been shown to be a pan-astrocyte marker and that its promoter can be used to specifically target astrocytes using the Cre-loxP system. In this study we explored whether the recently described Aldh1L1-CreERT2 mouse line (Winchenbach et al., 2016) can serve to specifically target niche astrocytes without inducing recombination in NSCs in adult neurogenic niches. Using short- and long-term tamoxifen protocols we revealed high recombination efficiency and specificity in non-stem cell astrocytes and little to no recombination in NSCs of the adult DG. However, in the SEZ we observed recombination in ependymal cells, astrocytes, and NSCs, the latter giving rise to neuronal progeny of the rostral migratory stream and olfactory bulb. Thus, we recommend the here described Aldh1L1-CreERT2 mouse line for predominantly studying the functions of non-stem cell astrocytes in the DG under physiological and pathological conditions.

2016 ◽  
Author(s):  
Marcos Assis Nascimento ◽  
Lydia Sorokin ◽  
Tatiana Coelho-Sampaio

AbstractFractones are extracellular matrix structures in the neural stem cell niche of the subventricular zone (SVZ), where they appear as round deposits named bulbs or thin branching lines called stems. Their cellular origin and what determines their localization at this site is poorly studied and it remains unclear whether they influence neural stem and progenitor cells formation, proliferation and/or maintenance. To address these questions, we analyzed whole mount preparations of the lateral ventricle by confocal microscopy using different extracellular matrix and cell markers. We found that bulbs are rarely connected to stems and that they contain laminin α5 and α2 chains, respectively. Fractone bulbs were profusely distributed throughout the SVZ and appeared associated with the center of pinwheels, a critical site for adult neurogenesis. We demonstrate that bulbs appear at the apical membrane of ependymal cells at the end of the first week after birth. The use of transgenic mice lacking laminin α5 gene expression (Lama5) in endothelium and in FoxJ1-expressing ependymal cells, revealed ependymal cells as the source of laminin α5-containing fractone bulbs. Loss of laminin α5 from bulbs correlated with a 60% increase in cell proliferation, as determined by PH3 staining, and with a selective reduction in the number of quiescent neural stem cells in the SVZ. These results indicate that fractones are a key component of the SVZ and suggest that laminin α5 modulates the physiology of the neural stem cell niche.Significance StatementOur work unveils key aspects of fractones, extracellular matrix structures present in the SVZ that still lack a comprehensive characterization. We show that fractones extensively interact with neural stem cells, whereas some of them are located precisely at pinwheel centers, which are hotspots for adult neurogenesis. Our results also demonstrate that fractones increase in size during aging and that their interactions with NSPCs become more complex in old mice. Lastly, we show that fractone bulbs are produced by ependymal cells and that their laminin content regulates neural stem cells.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3471-3471
Author(s):  
Sarah Vaiselbuh ◽  
Jeffrey Michael Lipton ◽  
Johnson M. Liu

Abstract CD133 (prominin-1) is the first in a class of novel pentaspan membrane proteins identified in humans and mice, and studies have since confirmed the utility of CD133 as a marker of stem cells with hematopoietic and non-hematopoietic lineage potential. A number of human transplantation studies have documented hematopoietic reconstitution from CD133+ stem cells from mismatched donors, with a suggested advantage over standard grafts in avoidance of graft versus host disease. We have developed a novel hematopoietic culture system (Long-Term Stem Cell Culture or LTSCC) to investigate the potential of human mesenchymal stem cells (MSC) to form stroma that can support short- and long-term hematopoiesis derived from cord blood (CB)-derived CD133+ cells. In addition, we analyzed the effect of stromal derived factor-1 (SDF-1/CXCL12) on survival and short-and long-term colony-forming capacity of CD133+ hematopoiesis. LTSCC induced stroma-like changes in the MSC feeder layer, with adipocyte formation, thought to be needed for formation of stem cell niches, and supported long-term (>9 weeks) survival of CB-CD133+ cells. Cobblestone areas of active CD133-derived hematopoiesis were seen in LTSCC for up to 9 weeks of culture. SDF-1/CXCL12 acted as a survival factor for CB-CD133+ cells and induced a significant ex vivo cell expansion at weeks 3 and 4 of LTSCC (maximal 500-fold increase), while maintaining the capacity for CFU-Mix and BFU-E colony formation up to 7 weeks. Long-term hematopoiesis was assessed by enumeration of long-term culture initiating cells (LTC-IC). When SDF-1/CXCL12 was added to LTSCC, we found a significant increase in LTC-IC: 0.3% (+SDF-1/CXCL12) vs. 0.05% (-SDF-1/CXCL12). Finally, homing capacity, as defined by SDF-1/CXCL12-induced adhesion and migration of CB-CD133+ cells, was maintained and even increased during the first 3 weeks of LTSCC. In summary, MSC can be maintained in LTSCC medium, and this simplified feeder layer is able to provide niches for cobblestone area forming cells derived from CB-CD133+ cells. SDF-1/CXCL12 is critical to support the survival and expansion of CD133+ cells, either directly or indirectly by paracrinesignaled retention of CD133+ cells in contact with specialized MSC niches. We suggest that expansion of CD133+ cells from cord blood may be useful in clinical transplantation limited by insufficient numbers of stem cells.


2015 ◽  
Vol 52 (2) ◽  
pp. 927-933 ◽  
Author(s):  
Zhen He ◽  
Li Cui ◽  
Merle G. Paule ◽  
Sherry A. Ferguson

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A73-A73
Author(s):  
Nikki Gill ◽  
Suban Burale ◽  
Neerupma Silswal ◽  
Donald Benedict DeFranco ◽  
Paula Monaghan-Nichols

Abstract Preterm birth-birth before 37 weeks of pregnancy-can cause many short- and long-term complications in newborns, including respiratory distress syndrome (RDS). RDS results from incomplete lung development and a surfactant deficiency, and it is a major factor of pre-term mortality. Synthetic glucocorticoids (sGCs) such as Betamethasone or Dexamethasone (Beta, Dex) are administered prenatally to women at risk of pre-term birth to prevent preterm complications. While sGCs are known to improve outcome, they also cause alterations in brain development and neural stem cell biology that are associated with long-term neurological defects. One common recreational drug used during pregnancy is cannabis. Some of the active components of cannabis include cannabinoids, which interact with the endocannabinoid receptor pathway in cells. Cannabinoids have been shown to induce proliferation and differentiation of embryonic neural stem cells (NSCs). We hypothesized that maternal cannabis use activates cannabinoid signaling pathways and leads to changes in glucocorticoid signaling in the developing brain. The purpose of this study was to determine whether cannabis use leads to a better or worse neurological outcome for children born pre-term and treated with sGCs for RDS. Neural stem cell neurospheres (NSCs) were isolated from the cerebral cortex of mice and treated with Vehicle (ethanol), Dex, cannabinoid receptor agonist WIN-55,212-2 (Win), or a combination WinDex. The transcriptional profile induced by exposure to Vehicle, Dex, and WinDex RNA were analyzed using microarray analyses examining the complete expressed genome. Gene Chip profiles indicated that both glucocorticoids and cannabinoids induce distinct transcriptional responses in E14.5 NSCs. The genes involved in proliferation-including S100a11, Jun, and Bex2-were repressed by Dex whereas WinDex rescued some of these expression profiles. Some genes encoding microRNA that inhibit our top target coding genes implicated in proliferation showed a greater induction by Dex compared to WinDex. Quantitative Polymerase Chain Reaction (qPCR) was performed to validate our genes of interest, including Adm, which has been shown to induce neural stem cell proliferation and differentiation. The biological impact of Winn on Dex-induced changes in NSC function were examined by in-vitro proliferation and differentiation studies using antibodies to Tuj1 (neurons), GFAP (glia), and CNPase (immature oligodendrocytes). The experiments indicate that Dex increased neuronal and oligodendrocyte differentiation, while WinDex appeared to reverse this phenotype in neurons. These studies suggest that cannabis use during pregnancy may limit the biological impact sGCs for preterm birth and lead to distinct cellular responses.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Xiaosong Zhi ◽  
Jun Xiong ◽  
Mengchao Wang ◽  
Hongxia Zhang ◽  
Gang Huang ◽  
...  

Induced hepatic stem cells (iHepSCs) have great potential as donors for liver cell therapy due to their self-renewal and bipotential differentiation properties. However, the efficiency of bidifferentiation and repopulation efficiency of iHepSCs is relatively low. Recent evidence shows that physiological hypoxia, a vital factor within stem cell “niche” microenvironment, plays key roles in regulating tissue stem cell biological behaviors including proliferation and differentiation. In this study, we found that physiological hypoxia (10% O2) enhanced the stemness properties and promoted the proliferation ability of iHepSCs by accelerating G1/S transition via p53-p21 signaling pathway. In addition, short-term hypoxia preconditioning improved the efficiency of hepatic differentiation of iHepSCs, and long-term hypoxia promoted cholangiocytic differentiation but inhibited hepatic differentiation of iHepSCs. These results demonstrated the potential effects of hypoxia on stemness preservation, proliferation, and bidifferentiation of iHepSCs and promising perspective to explore appropriate culture conditions for therapeutic stem cells.


Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 90
Author(s):  
Pilar Carreras ◽  
Itziar González ◽  
Miguel Gallardo ◽  
Alejandra Ortiz-Ruiz ◽  
Maria Luz Morales ◽  
...  

We previously reported a new approach for micromanipulation and encapsulation of human stem cells using a droplet-based microfluidic device. This approach demonstrated the possibility of encapsulating and culturing difficult-to-preserve primary human hematopoietic stem cells using an engineered double-layered bead composed by an inner layer of alginate and an outer layer of Puramatrix. We also demonstrated the maintenance and expansion of Multiple Myeloma cells in this construction. Here, the presented microfluidic technique is applied to construct a 3D biomimetic model to recapitulate the human hematopoietic stem cell niche using double-layered hydrogel beads cultured in 10% FBS culture medium. In this model, the long-term maintenance of the number of cells and expansion of hHSCS encapsulated in the proposed structures was observed. Additionally, a phenotypic characterization of the human hematopoietic stem cells generated in the presented biomimetic model was performed in order to assess their long-term stemness maintenance. Results indicate that the ex vivo cultured human CD34+ cells from bone marrow were viable, maintained, and expanded over a time span of eight weeks. This novel long-term stem cell culture methodology could represent a novel breakthrough to improve Hematopoietic Progenitor cell Transplant (HPT) as well as a novel tool for further study of the biochemical and biophysical factors influencing stem cell behavior. This technology opens a myriad of new applications as a universal stem cell niche model potentially able to expand other types of cells.


eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Pauline Spéder ◽  
Andrea H Brand

Successful neurogenesis requires adequate proliferation of neural stem cells (NSCs) and their progeny, followed by neuronal differentiation, maturation and survival. NSCs inhabit a complex cellular microenvironment, the niche, which influences their behaviour. To ensure sustained neurogenesis, niche cells must respond to extrinsic, environmental changes whilst fulfilling the intrinsic requirements of the neurogenic program and adapting their roles accordingly. However, very little is known about how different niche cells adjust their properties to such inputs. Here, we show that nutritional and NSC-derived signals induce the remodelling of Drosophila cortex glia, adapting this glial niche to the evolving needs of NSCs. First, nutrition-induced activation of PI3K/Akt drives the cortex glia to expand their membrane processes. Second, when NSCs emerge from quiescence to resume proliferation, they signal to glia to promote membrane remodelling and the formation of a bespoke structure around each NSC lineage. The remodelled glial niche is essential for newborn neuron survival.


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