scholarly journals GABA exists as a negative regulator of cell proliferation in spermaogonial stem cells

2013 ◽  
Vol 18 (2) ◽  
Author(s):  
Yong Du ◽  
Zhao Du ◽  
Hongping Zheng ◽  
Dan Wang ◽  
Shifeng Li ◽  
...  
Keyword(s):  
Stem Cells ◽  
Culture System ◽  
Histone H3 ◽  
Negative Regulator ◽  
Peripheral Tissues ◽  
Inhibitory Neurotransmitter ◽  
Amino Butyric Acid

Abstractγ-amino butyric acid (GABA) is the main inhibitory neurotransmitter in the mammalian central nervous system. GABA is also found in many peripheral tissues, where it has important functions during development. Here, we identified the existence of the GABA system in spermatogonial stem cells (SSCs) and found that GABA negatively regulates SSC proliferation. First, we demonstrated that GABA and its synthesizing enzymes were abundant in the testes 6 days postpartum (dpp), suggesting that GABA signaling regulates SSCs function in vivo. In order to directly examine the effect of GABA on SSC proliferation, we then established an in vitro culture system for long-term expansion of SSCs. We showed that GABAA receptor subunits, including α1, α5, β1, β2, β3 and γ3, the synthesizing enzyme GAD67, and the transporter GAT-1, are expressed in SSCs. Using phosphorylated histone H3 (pH3) staining, we demonstrated that GABA or the GABAAR-specific agonist muscimol reduced the proliferation of SSCs. This GABA regulation of SSC proliferation was shown to be independent of apoptosis using the TUNEL assay. These results suggest that GABA acts as a negative regulator of SSC proliferation to maintain the homeostasis of spermatogenesis in the testes.

Strategies to Protect Hematopoietic Stem Cells from Culture-Induced Stress Conditions

2020 ◽  
Vol 15 ◽  
Author(s):  
Fatima Aerts-Kaya
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Ex Vivo ◽  
Stress Conditions ◽  
Stress Factors ◽  
Hematopoietic Stem ◽  
Induced Stress

: In contrast to their almost unlimited potential for expansion in vivo and despite years of dedicated research and optimization of expansion protocols, the expansion of Hematopoietic Stem Cells (HSCs) in vitro remains remarkably limited. Increased understanding of the mechanisms that are involved in maintenance, expansion and differentiation of HSCs will enable the development of better protocols for expansion of HSCs. This will allow procurement of HSCs with long-term engraftment potential and a better understanding of the effects of the external influences in and on the hematopoietic niche that may affect HSC function. During collection and culture of HSCs, the cells are exposed to suboptimal conditions that may induce different levels of stress and ultimately affect their self-renewal, differentiation and long-term engraftment potential. Some of these stress factors include normoxia, oxidative stress, extra-physiologic oxygen shock/stress (EPHOSS), endoplasmic reticulum (ER) stress, replicative stress, and stress related to DNA damage. Coping with these stress factors may help reduce the negative effects of cell culture on HSC potential, provide a better understanding of the true impact of certain treatments in the absence of confounding stress factors. This may facilitate the development of better ex vivo expansion protocols of HSCs with long-term engraftment potential without induction of stem cell exhaustion by cellular senescence or loss of cell viability. This review summarizes some of available strategies that may be used to protect HSCs from culture-induced stress conditions.

scholarly journals Expression Profile of New Marker Genes Involved in Differentiation of Canine Adipose-Derived Stem Cells into Osteoblasts

2021 ◽  
Vol 22 (13) ◽  
pp. 6663
Author(s):  
Maurycy Jankowski ◽  
Mariusz Kaczmarek ◽  
Grzegorz Wąsiatycz ◽  
Claudia Dompe ◽  
Paul Mozdziak ◽  
...  
Keyword(s):  
Stem Cells ◽  
In Vitro Culture ◽  
Osteogenic Differentiation ◽  
Molecular Mechanisms ◽  
Marker Genes ◽  
P Value ◽  
Illumina Platform

Next-generation sequencing (RNAseq) analysis of gene expression changes during the long-term in vitro culture and osteogenic differentiation of ASCs remains to be important, as the analysis provides important clues toward employing stem cells as a therapeutic intervention. In this study, the cells were isolated from adipose tissue obtained during routine surgical procedures and subjected to 14-day in vitro culture and differentiation. The mRNA transcript levels were evaluated using the Illumina platform, resulting in the detection of 19,856 gene transcripts. The most differentially expressed genes (fold change >|2|, adjusted p value < 0.05), between day 1, day 14 and differentiated cell cultures were extracted and subjected to bioinformatical analysis based on the R programming language. The results of this study provide molecular insight into the processes that occur during long-term in vitro culture and osteogenic differentiation of ASCs, allowing the re-evaluation of the roles of some genes in MSC progression towards a range of lineages. The results improve the knowledge of the molecular mechanisms associated with long-term in vitro culture and differentiation of ASCs, as well as providing a point of reference for potential in vivo and clinical studies regarding these cells’ application in regenerative medicine.

scholarly journals Chemically defined and xeno-free culture condition for human extended pluripotent stem cells

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Bei Liu ◽  
Shi Chen ◽  
Yaxing Xu ◽  
Yulin Lyu ◽  
Jinlin Wang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Pluripotent Stem Cells ◽  
Culture Condition ◽  
Human Fibroblast ◽  
Culture System ◽  
Disease Modeling ◽  
Directed Differentiation

AbstractExtended pluripotent stem (EPS) cells have shown great applicative potentials in generating synthetic embryos, directed differentiation and disease modeling. However, the lack of a xeno-free culture condition has significantly limited their applications. Here, we report a chemically defined and xeno-free culture system for culturing and deriving human EPS cells in vitro. Xeno-free human EPS cells can be long-term and genetically stably maintained in vitro, as well as preserve their embryonic and extraembryonic developmental potentials. Furthermore, the xeno-free culturing system also permits efficient derivation of human EPS cells from human fibroblast through reprogramming. Our study could have broad utility in future applications of human EPS cells in biomedicine.

scholarly journals Genome-wide CRISPR-Cas9 screen identified KLF11 as a druggable suppressor for sarcoma cancer stem cells

2021 ◽  
Vol 7 (5) ◽  
pp. eabe3445
Author(s):  
Yicun Wang ◽  
Jinhui Wu ◽  
Hui Chen ◽  
Yang Yang ◽  
Chengwu Xiao ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cancer Stem Cells ◽  
Negative Feedback ◽  
Direct Interaction ◽  
Therapy Resistance ◽  
Negative Regulator ◽  
Chemotherapy Response ◽  
Genome Wide

Cancer stem cells (CSCs) are involved in tumorigenesis, recurrence, and therapy resistance. To identify critical regulators of sarcoma CSCs, we performed a reporter-based genome-wide CRISPR-Cas9 screen and uncovered Kruppel-like factor 11 (KLF11) as top candidate. In vitro and in vivo functional annotation defined a negative role of KLF11 in CSCs. Mechanistically, KLF11 and YAP/TEAD bound to adjacent DNA sites along with direct interaction. KLF11 recruited SIN3A/HDAC to suppress the transcriptional output of YAP/TEAD, which, in turn, promoted KLF11 transcription, forming a negative feedback loop. However, in CSCs, this negative feedback was lost because of epigenetic silence of KLF11, causing sustained YAP activation. Low KLF11 was associated with poor prognosis and chemotherapy response in patients with sarcoma. Pharmacological activation of KLF11 by thiazolidinedione effectively restored chemotherapy response. Collectively, our study identifies KLF11 as a negative regulator in sarcoma CSCs and potential therapeutic target.

scholarly journals Soft Substrate Maintains Proliferative and Adipogenic Differentiation Potential of human Mesenchymal Stem Cells on Long Term Expansion by Delaying Senescence

2018 ◽  
Author(s):  
Sanjay K. Kureel ◽  
Pankaj Mogha ◽  
Akshada Khadpekar ◽  
Vardhman Kumar ◽  
Rohit Joshi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Culture System ◽  
Human Mesenchymal Stem Cells ◽  
Population Doubling ◽  
Differentiation Potential ◽  
Lineage Differentiation ◽  
Poly Acrylamide

AbstractHuman mesenchymal stem cells (hMSCs), when cultured on tissue culture plate (TCP) for in vitro expansion, they spontaneously lose their proliferative capacity and multi-lineage differentiation potential. They also lose their distinct spindle morphology and become large and flat. After a certain number of population doubling, they enter into permanent cell cycle arrest, called senescence. This is a major roadblock for clinical use of hMSCs which demands large number of cells. A cell culture system is needed which can maintain the stemness of hMSCs over long term passages yet simple to use. In this study, we explore the role of substrate rigidity in maintaining stemness. hMSCs were serially passaged on TCP and 5 kPa poly-acrylamide gel for 20 population doubling. It was found that while on TCP, cell growth reached a plateau at cumulative population doubling (CPD) = 12.5, on 5 kPa gel, they continue to proliferate linearly till we monitored (CPD = 20). We also found that while on TCP, late passage MSCs lost their adipogenic potential, the same was maintained on soft gel. Cell surface markers related to MSCs were also unaltered. We demonstrated that this maintenance of stemness was correlated with delay in onset of senescence, which was confirmed by β-gal assay and by differential expression of vimentin, Lamin A and Lamin B. As preparation of poly-acrylamide gel is a simple, well established, and well standardized protocol, we believe that this system of cell expansion will be useful in therapeutic and research applications of hMSCs.One Sentence SummaryhMSCs retain their stemness when expanded in vitro on soft polyacrylamide gel coated with collagen by delaying senescence.Significance StatementFor clinical applications, mesenchymal stem cells (MSCs) are required in large numbers. As MSCs are available only in scarcity in vivo, to fulfill the need, extensive in vitro expansion is unavoidable. However, on expansion, they lose their replicative and multi-lineage differentiation potential and become senescent. A culture system that can maintain MSC stemness on long-term expansion, without compromising the stemness, is need of the hour. In this paper, we identified polyacrylamide (PAA) hydrogel of optimum stiffness that can be used to maintain stemness of MSCs during in vitro long term culture. Large quantity of MSCs thus grown can be used in regenerative medicine, cell therapy, and in treatment of inflammatory diseases.

scholarly journals Hematopoietic stem/progenitor cells, generation of induced pluripotent stem cells, and isolation of endothelial progenitors from 21- to 23.5-year cryopreserved cord blood

Blood ◽  
2011 ◽  
Vol 117 (18) ◽  
pp. 4773-4777 ◽  
Author(s):  
Hal E. Broxmeyer ◽  
Man-Ryul Lee ◽  
Giao Hangoc ◽  
Scott Cooper ◽  
Nutan Prasain ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cord Blood ◽  
Progenitor Cells ◽  
Proliferative Potential ◽  
Hematopoietic Stem ◽  
Immunodeficient Mice ◽  
Induced Pluripotent

Abstract Cryopreservation of hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) is crucial for cord blood (CB) banking and transplantation. We evaluated recovery of functional HPC cryopreserved as mononuclear or unseparated cells for up to 23.5 years compared with prefreeze values of the same CB units. Highly efficient recovery (80%-100%) was apparent for granulocyte-macrophage and multipotential hematopoietic progenitors, although some collections had reproducible low recovery. Proliferative potential, response to multiple cytokines, and replating of HPC colonies was extensive. CD34+ cells isolated from CB cryopreserved for up to 21 years had long-term (≥ 6 month) engrafting capability in primary and secondary immunodeficient mice reflecting recovery of long-term repopulating, self-renewing HSCs. We recovered functionally responsive CD4+ and CD8+ T lymphocytes, generated induced pluripotent stem (iPS) cells with differentiation representing all 3 germ cell lineages in vitro and in vivo, and detected high proliferative endothelial colony forming cells, results of relevance to CB biology and banking.

scholarly journals Transcriptome Profiling of Panc-1 Spheroid Cells with Pancreatic Cancer Stem Cells Properties Cultured by a Novel 3D Semi-Solid System

2018 ◽  
Vol 47 (5) ◽  
pp. 2109-2125 ◽  
Author(s):  
Zhaocong Yang ◽  
Yanfeng Zhang ◽  
Tingting Tang ◽  
Qinhua Zhu ◽  
Wanyue Shi ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Stem Cells ◽  
Cancer Stem Cells ◽  
Culture System ◽  
High Throughput Sequencing ◽  
Semi Solid ◽  
Pancreatic Cancer Stem Cells ◽  
Solid System

Background/Aims: Pancreatic cancer remains one of the deadliest human malignancies, the lethality of which may be attributed to the presence of pancreatic cancer stem cells (PCSCs), a small subpopulation of cells existing within pancreatic tumor with high carcinogenesis. Therefore, it is crucial to establish an efficient enrichment and culture system of PCSCs and identify the key genes involved in the regulation of PCSCs. The three-dimensional (3D) liquid suspension mammosphere culture system has been established for enrichment and culture of PCSCs in vitro as the cell spheres are likely to originate from individual cell clone, but it has been challenged because the cell spheroids could be a result of cell aggregation. Methods: We optimized the existing culture system by adding methylcellulose to create a 3D semi-solid system which prevented the non-specific aggregation. Then we identified the CSC properties of Panc-1 spheroid cells cultured by this system by detecting the genes associated with stemness and by evaluation of the tumorigenicity in vitro and in vivo through invasion, migration and xenograft experiments methods. Subsequently, we performed high-throughput sequencing (HTS) of the Panc-1 spheroid cells. Results: We confirmed the PCSCs properties and high malignancy of the Panc-1 spheroid cells enriched by our novel 3D semi-solid system both in vitro and in vivo. Hundreds of mRNA, microRNA (miRNA) and dozens of long non-coding RNA (LncRNA) were identified to be differentially regulated in PCSCs-like Panc-1 spheroid cells compared with their parental cells by HTS. Conclusions: Our results demonstrate an efficient enrichment and culture system for Panc-1 spheroid cells with the PCSCs properties. The differentially expressed genes and their targets identified by the HTS of the Panc-1 spheroid cells can serve as new potential biomarkers for pancreatic cancer diagnosis and targeted therapy.

scholarly journals Sustained, retransplantable, multilineage engraftment of highly purified adult human bone marrow stem cells in vivo

Blood ◽  
1996 ◽  
Vol 88 (11) ◽  
pp. 4102-4109 ◽  
Author(s):  
CI Civin ◽  
G Almeida-Porada ◽  
MJ Lee ◽  
J Olweus ◽  
LW Terstappen ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Cell Population ◽  
Mononuclear Cells ◽  
Cell Subset ◽  
Fetal Sheep ◽  
Adult Human

Abstract Data from many laboratory and clinical investigations indicate that CD34+ cells comprise approximately 1% of human bone marrow (BM) mononuclear cells, including the progenitor cells of all the lymphohematopoietic lineages and lymphohematopoietic stem cells (stem cells). Because stem cells are an important but rare cell type in the CD34+ cell population, investigators have subdivided the CD34+ cell population to further enrich stem cells. The CD34+/CD38-cell subset comprises less than 10% of human CD34+ adult BM cells (equivalent to < 0.1% of marrow mononuclear cells), lacks lineage (lin) antigens, contains cells with in vitro replating capacity, and is predicted to be highly enriched for stem cells. The present investigation tested whether the CD34+/CD38-subset of adult human marrow generates human hematopoiesis after transfer to preimmune fetal sheep. CD34+/ CD38- cells purified from marrow using immunomagnetic microspheres or fluorescence-activated cell sorting generated easily detectable, long- term, multilineage human hematopoiesis in the human-fetal sheep in vivo model. In contrast, transfer of CD34+/CD38+ cells to preimmune fetal sheep generated only short-term human hematopoiesis, possibly suggesting that the CD34+/CD38+ cell population contains relatively early multipotent hematopoletic progenitor cells, but not stem cells. This work extends the prior in vitro evidence that the earliest cells in fetal and adult human marrow lack CD38 expression. In summary, the CD34+/ CD38-cell population has a high capacity for long-term multilineage hematopoietic engraftment, suggesting the presence of stem cells in this minor adult human marrow cell subset.

scholarly journals Use of 5-fluorouracil to analyze the effect of macrophage inflammatory protein-1 alpha on long-term reconstituting stem cells in vivo

Blood ◽  
1993 ◽  
Vol 81 (6) ◽  
pp. 1497-1504 ◽  
Author(s):  
VF Quesniaux ◽  
GJ Graham ◽  
I Pragnell ◽  
D Donaldson ◽  
SD Wolpe ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Inhibitory Effect ◽  
In Vivo Model ◽  
Hematopoietic Progenitors ◽  
Inflammatory Protein ◽  
Macrophage Inflammatory Protein

Abstract A macrophage-derived inhibitor of early hematopoietic progenitors (colony-forming unit-spleen, CFU-A) called stem cell inhibitor was found to be identical to macrophage inflammatory protein-1 alpha (MIP-1 alpha). We investigated the effect of MIP-1 alpha on the earliest stem cells that sustain long-term hematopoiesis in vivo in a competitive bone marrow repopulation assay. Because long-term reconstituting (LTR) stem cells are normally quiescent, an in vivo model was first developed in which they are triggered to cycle. A first 5-fluorouracil (5-FU) injection was used to eliminate later progenitors, causing the LTR stem cells, which are normally resistant to 5-FU, to enter the cell cycle and become sensitive to a second 5-FU injection administered 5 days later. Human MIP-1 alpha administered from day 0 to 7 was unable to prevent the depletion of the LTR stem cells by the second 5-FU treatment, as observed on day 7 in this model, suggesting that the LTR stem cells were not prevented from being triggered into cycle despite the MIP-1 alpha treatment. However, the MIP-1 alpha protocol used here did substantially decrease the number of more mature hematopoietic progenitors (granulocyte-macrophage colony-forming cells [CFC], burst- forming unit-erythroid, CFCmulti, and preCFCmulti) recovered in the bone marrow shortly after a single 5-FU injection. In vitro, MIP-1 alpha had no inhibitory effect on the ability of these progenitors to form colonies. This study confirms the in vivo inhibitory effect of MIP- 1 alpha on subpopulations of hematopoietic progenitors that are activated in myelodepressed animals. However, MIP-1 alpha had no effect on the long-term reconstituting stem cells in vivo under conditions in which it effectively reduced all later progenitors.

Long-Term Ex Vivo Maintenance and Expansion of Transplantable Human Hematopoietic Stem Cells

Blood ◽  
1999 ◽  
Vol 94 (5) ◽  
pp. 1623-1636 ◽  
Author(s):  
Chu-Chih Shih ◽  
Mickey C.-T. Hu ◽  
Jun Hu ◽  
Jeffrey Medeiros ◽  
Stephen J. Forman
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
In Vitro Culture ◽  
Culture System ◽  
Ex Vivo ◽  
Human Stem Cells ◽  
Hematopoietic Stem ◽  
In Vitro Culture System

Abstract We have developed a stromal-based in vitro culture system that facilitates ex vivo expansion of transplantable CD34+thy-1+ cells using long-term hematopoietic reconstitution in severe combined immunodeficient-human (SCID-hu) mice as an in vivo assay for transplantable human hematopoietic stem cells (HSCs). The addition of leukemia inhibitory factor (LIF) to purified CD34+ thy-1+ cells on AC6.21 stroma, a murine bone marrow–derived stromal cell line, caused expansion of cells with CD34+ thy-1+ phenotype. Addition of other cytokines, including interleukin-3 (IL-3), IL-6, granulocyte-macrophage colony-stimulating factor, and stem cell factor, to LIF in the cultures caused a 150-fold expansion of cells retaining the CD34+ thy-1+ phenotype. The ex vivo–expanded CD34+ thy-1+ cells gave rise to multilineage differentiation, including myeloid, T, and B cells, when transplanted into SCID-hu mice. Both murine LIF (cannot bind to human LIF receptor) and human LIF caused expansion of human CD34+ thy-1+ cells in vitro, suggesting action through the murine stroma. Furthermore, another human HSC candidate, CD34+ CD38− cells, shows a similar pattern of proliferative response. This suggests thatex vivo expansion of transplantable human stem cells under this in vitro culture system is a general phenomenon and not just specific for CD34+ thy-1+ cells.

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