Niche Laminin and IGF-1 Additively Coordinate the Maintenance of Oct-4 Through CD49f/IGF-1R-Hif-2α Feedforward Loop in Mouse Germline Stem Cells

The mechanism on how extracellular matrix (ECM) cooperates with niche growth factors and oxygen tension to regulate the self-renewal of embryonic germline stem cells (GSCs) still remains unclear. Lacking of an appropriate in vitro cell model dramatically hinders the progress. Herein, using a serum-free culture system, we demonstrated that ECM laminin cooperated with hypoxia and insulin-like growth factor 1 receptor (IGF-1R) to additively maintain AP activity and Oct-4 expression of AP+GSCs. We found the laminin receptor CD49f expression in d2 testicular GSCs that were surrounded by laminin. Laminin and hypoxia significantly increased the GSC stemness-related genes, including Hif-2α, Oct-4, IGF-1R, and CD49f. Cotreatment of IGF-1 and laminin additively increased the expression of IGF-IR, CD49f, Hif-2α, and Oct-4. Conversely, silencing IGF-1R and/or CD49f decreased the expression of Hif-2α and Oct-4. The underlying mechanism involved CD49f/IGF1R-(PI3K/AKT)-Hif-2α signaling loop, which in turn maintains Oct-4 expression, symmetric self-renewal, and cell migration. These findings reveal the additive niche laminin/IGF-IR network during early GSC development.

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Establishment of a feeder and serum-free culture system for human embryonic stem cells

Zygote ◽

10.1017/s0967199419000625 ◽

2020 ◽

Vol 28 (3) ◽

pp. 175-182

Author(s):

LiYun Wang ◽

RuiNa Zhang ◽

RongHua Ma ◽

GongXue Jia ◽

ShengYan Jian ◽

...

Keyword(s):

Stem Cells ◽

Embryonic Stem Cells ◽

Human Embryonic Stem Cells ◽

Culture System ◽

Embryonic Stem ◽

Hesc Line ◽

Self Renewal ◽

Serum Free ◽

Genes Encoding

SummaryStem cells are an immortal cell population capable of self-renewal; they are essential for human development and ageing and are a major focus of research in regenerative medicine. Despite considerable progress in differentiation of stem cells in vitro, culture conditions require further optimization to maximize the potential for multicellular differentiation during expansion. The aim of this study was to develop a feeder-free, serum-free culture method for human embryonic stem cells (hESCs), to establish optimal conditions for hESC proliferation, and to determine the biological characteristics of the resulting hESCs. The H9 hESC line was cultured using a homemade serum-free, feeder-free culture system, and growth was observed. The expression of pluripotency proteins (OCT4, NANOG, SOX2, LIN28, SSEA-3, SSEA-4, TRA-1-60, and TRA-1-81) in hESCs was determined by immunofluorescence and western blotting. The mRNA expression levels of genes encoding nestin, brachyury and α-fetoprotein in differentiated H9 cells were determined by RT-PCR. The newly developed culture system resulted in classical hESC colonies that were round or elliptical in shape, with clear and neat boundaries. The expression of pluripotency proteins was increased, and the genes encoding nestin, brachyury, and α-fetoprotein were expressed in H9 cells, suggesting that the cells maintained in vitro differentiation capacity. Our culture system containing a unique set of components, with animal-derived substances, maintained the self-renewal potential and pluripotency of H9 cells for eight passages. Further optimization of this system may expand the clinical application of hESCs.

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Enrichment of Female Germline Stem Cells from Mouse Ovaries Using the Differential Adhesion Method

Cellular Physiology and Biochemistry ◽

10.1159/000489452 ◽

2018 ◽

Vol 46 (5) ◽

pp. 2114-2126 ◽

Cited By ~ 10

Author(s):

Meng Wu ◽

Jiaqiang Xiong ◽

Lingwei Ma ◽

Zhiyong Lu ◽

Xian Qin ◽

...

Keyword(s):

Stem Cells ◽

Akt Pathway ◽

Germline Stem Cells ◽

Self Renewal ◽

Differential Adhesion ◽

Proliferation And Differentiation ◽

Phosphoinositide 3 Kinase ◽

Female Germline

Background/Aims: The isolation and establishment of female germline stem cells (FGSCs) is controversial because of questions regarding the reliability and stability of the isolation method using antibody targeting mouse vasa homologue (MVH), and the molecular mechanism of FGSCs self-renewal remains unclear. Thus, there needs to be a simple and reliable method for sorting FGSCs to study them. Methods: We applied the differential adhesion method to enrich FGSCs (DA-FGSCs) from mouse ovaries. Through four rounds of purification and 7-9 subsequent passages, DA-FGSC lines were established. In addition, we assessed the role of the phosphoinositide-3 kinase (PI3K)-AKT pathway in regulating FGSC self-renewal. Results: The obtained DA-FGSCs spontaneously differentiated into oocyte-like cells in vitro and formed functional eggs in vivo that were fertilized and produced healthy offspring. AKT was rapidly phosphorylated when the proliferation rate of FGSCs increased after 10 passages, and the addition of a chemical PI3K inhibitor prevented FGSCs self-renewal. Furthermore, over-expression of AKT-induced proliferation and differentiation of FGSCs, c-Myc, Oct-4 and Gdf-9 levels were increased. Conclusions: The differential adhesion method provides a more feasible approach and is an easier procedure to establish FGSC lines than traditional methods. The AKT pathway plays an important role in regulation of the proliferation and maintenance of FGSCs. These findings could help promote stem cell studies and provide a better understanding of causes of ovarian infertility, thereby providing potential treatments for infertility.

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Studies of human pluripotential hemopoietic stem cells (CFU-GEMM) in vitro

Blood ◽

10.1182/blood.v58.2.309.bloodjournal582309 ◽

1981 ◽

Vol 58 (2) ◽

pp. 309-316 ◽

Cited By ~ 3

Author(s):

RC Ash ◽

DA Detrick ◽

ED Zanjani

Keyword(s):

Stem Cells ◽

Culture System ◽

Cell Populations ◽

In Vitro Growth ◽

Limited Capacity ◽

Self Renewal ◽

Low Frequencies ◽

Cell Class ◽

Clonal Assay

An in vitro clonal assay for a class of human hemopoietic progenitors (CFU-GEMM) with several characteristics of pluripotential stem cells has been previously described. In the presence of medium conditioned by leukocytes stimulated with phytohemagglutinin (PHA-LCM) and erythropoietin (Ep), CFU-GEMM give rise to mixed hemopoietic colonies containing granulocytic, erythroid, monocyte-macrophage, and megakaryocytic elements. In initial studies we found that CFU-GEMM were present in equal but low frequencies in blood (B) and bone marrow (M) mononuclear cell populations. However, when the culture system was modified by the substitution of Iscove's modified Dulbecco's medium for alpha-MEM and the addition of mercaptoethanol, a significant enhancement of mixed colony formation occurred, and an approximately 3- 4-fold difference in the frequency of CFU-GEMM between B and M emerged. Replating studies showed the formation of secondary differentiated hemopoietic colonies and at least a limited capacity for self-renewal of CFU-GEMM. The in vitro growth of normal CFU-GEMM was highly dependent on hemopoietin(s) present in PHA-LCM. In vitro detection of CFU-GEMM, however, requires only relatively low permissive concentrations of Ep, in contrast to the high Ep requirement for optimal BFU-E growth in vitro. These and other data described demonstrate CFU-GEMM to be a distinct multipotential stem cell class whose assay may prove useful in the study of human blood dyscrasias.

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Studies of human pluripotential hemopoietic stem cells (CFU-GEMM) in vitro

Blood ◽

10.1182/blood.v58.2.309.309 ◽

1981 ◽

Vol 58 (2) ◽

pp. 309-316 ◽

Cited By ~ 118

Author(s):

RC Ash ◽

DA Detrick ◽

ED Zanjani

Keyword(s):

Stem Cells ◽

Culture System ◽

Cell Populations ◽

In Vitro Growth ◽

Limited Capacity ◽

Self Renewal ◽

Low Frequencies ◽

Cell Class ◽

Clonal Assay

Abstract An in vitro clonal assay for a class of human hemopoietic progenitors (CFU-GEMM) with several characteristics of pluripotential stem cells has been previously described. In the presence of medium conditioned by leukocytes stimulated with phytohemagglutinin (PHA-LCM) and erythropoietin (Ep), CFU-GEMM give rise to mixed hemopoietic colonies containing granulocytic, erythroid, monocyte-macrophage, and megakaryocytic elements. In initial studies we found that CFU-GEMM were present in equal but low frequencies in blood (B) and bone marrow (M) mononuclear cell populations. However, when the culture system was modified by the substitution of Iscove's modified Dulbecco's medium for alpha-MEM and the addition of mercaptoethanol, a significant enhancement of mixed colony formation occurred, and an approximately 3- 4-fold difference in the frequency of CFU-GEMM between B and M emerged. Replating studies showed the formation of secondary differentiated hemopoietic colonies and at least a limited capacity for self-renewal of CFU-GEMM. The in vitro growth of normal CFU-GEMM was highly dependent on hemopoietin(s) present in PHA-LCM. In vitro detection of CFU-GEMM, however, requires only relatively low permissive concentrations of Ep, in contrast to the high Ep requirement for optimal BFU-E growth in vitro. These and other data described demonstrate CFU-GEMM to be a distinct multipotential stem cell class whose assay may prove useful in the study of human blood dyscrasias.

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Ascorbic acid can promote the generation and expansion of neuroepithelial-like stem cells derived from hiPS/ES cells under chemically defined conditions through promoting collagen synthesis

Stem Cell Research & Therapy ◽

10.1186/s13287-020-02115-6 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Rui Bai ◽

Yun Chang ◽

Amina Saleem ◽

Fujian Wu ◽

Lei Tian ◽

...

Keyword(s):

Stem Cells ◽

Culture System ◽

Collagen Synthesis ◽

Serum Free Medium ◽

Free Medium ◽

Serum Free ◽

Induction System ◽

Defined Culture

Abstract Introduction Spinal cord injury (SCI) is a neurological, medically incurable disorder. Human pluripotent stem cells (hPSCs) have the potential to generate neural stem/progenitor cells (NS/PCs), which hold promise in the treatment of SCI by transplantation. In our study, we aimed to establish a chemically defined culture system using serum-free medium and ascorbic acid (AA) to generate and expand long-term self-renewing neuroepithelial-like stem cells (lt-NES cells) differentiated from hPSCs effectively and stably. Methods We induced human embryonic stem cells (hESCs)/induced PSCs (iPSCs) to neurospheres using a newly established in vitro induction system. Moreover, lt-NES cells were derived from hESC/iPSC-neurospheres using two induction systems, i.e., conventional N2 medium with gelatin-coated plates (coated) and N2+AA medium without pre-coated plates (AA), and were characterized by reverse transcription polymerase chain reaction (RT-PCR) analysis and immunocytochemistry staining. Subsequently, lt-NES cells were induced to neurons. A microelectrode array (MEA) recording system was used to evaluate the functionality of the neurons differentiated from lt-NES cells. Finally, the mechanism underlying the induction of lt-NES cells by AA was explored through RNA-seq and the use of inhibitors. Results HESCs/iPSCs were efficiently induced to neurospheres using a newly established induction system in vitro. lt-NES cells derived from hESC/iPSC-neurospheres using the two induction systems (coated vs. AA) both expressed the neural pluripotency-associated genes PAX6, NESTIN, SOX1, and SOX2. After long-term cultivation, we found that they both exhibited long-term expansion for more than a dozen generations while maintaining neuropluripotency. Moreover, the lt-NES cells retained the ability to differentiate into general functional neurons that express β-tubulin at high levels. We also demonstrated that AA promotes the generation and long-term expansion of lt-NES cells by promoting collagen synthesis via the MEK-ERK1/2 pathway. Conclusions This new chemically defined culture system was stable and effective regarding the generation and culture of lt-NES cells induced from hESCs/iPSCs using serum-free medium combined with AA. The lt-NES cells induced under this culture system maintained their long-term expansion and neural pluripotency, with the potential to differentiate into functional neurons. Graphical abstract

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Faculty Opinions recommendation of Lgr5(+ve) stem cells drive self-renewal in the stomach and build long-lived gastric units in vitro.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1677956.1501058 ◽

2010 ◽

Author(s):

Richard Gilbertson

Keyword(s):

Stem Cells ◽

Self Renewal

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Cancer Stem Cell Microenvironment Models with Biomaterial Scaffolds In Vitro

Processes ◽

10.3390/pr9010045 ◽

2020 ◽

Vol 9 (1) ◽

pp. 45

Author(s):

Ghmkin Hassan ◽

Said M. Afify ◽

Shiro Kitano ◽

Akimasa Seno ◽

Hiroko Ishii ◽

...

Keyword(s):

Stem Cells ◽

Cancer Biology ◽

Advanced Technology ◽

Cancer Microenvironment ◽

Critical Factors ◽

Self Renewal ◽

Cell Microenvironment ◽

Biological Phenomena ◽

Biomaterial Scaffolds

Defined by its potential for self-renewal, differentiation and tumorigenicity, cancer stem cells (CSCs) are considered responsible for drug resistance and relapse. To understand the behavior of CSC, the effects of the microenvironment in each tissue are a matter of great concerns for scientists in cancer biology. However, there are many complicated obstacles in the mimicking the microenvironment of CSCs even with current advanced technology. In this context, novel biomaterials have widely been assessed as in vitro platforms for their ability to mimic cancer microenvironment. These efforts should be successful to identify and characterize various CSCs specific in each type of cancer. Therefore, extracellular matrix scaffolds made of biomaterial will modulate the interactions and facilitate the investigation of CSC associated with biological phenomena simplifying the complexity of the microenvironment. In this review, we summarize latest advances in biomaterial scaffolds, which are exploited to mimic CSC microenvironment, and their chemical and biological requirements with discussion. The discussion includes the possible effects on both cells in tumors and microenvironment to propose what the critical factors are in controlling the CSC microenvironment focusing the future investigation. Our insights on their availability in drug screening will also follow the discussion.

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SIRT1 attenuates sepsis-induced acute kidney injury via Beclin1 deacetylation-mediated autophagy activation

Cell Death and Disease ◽

10.1038/s41419-021-03508-y ◽

2021 ◽

Vol 12 (2) ◽

Author(s):

Zhiya Deng ◽

Maomao Sun ◽

Jie Wu ◽

Haihong Fang ◽

Shumin Cai ◽

...

Keyword(s):

Acute Kidney Injury ◽

Protective Effect ◽

Cell Model ◽

Kidney Injury ◽

Underlying Mechanism ◽

Autophagy Induction ◽

Promising Therapeutic Approach ◽

Related Proteins ◽

Caecal Ligation And Puncture

AbstractOur previous studies showed that silent mating-type information regulation 2 homologue-1 (SIRT1, a deacetylase) upregulation could attenuate sepsis-induced acute kidney injury (SAKI). Upregulated SIRT1 can deacetylate certain autophagy-related proteins (Beclin1, Atg5, Atg7 and LC3) in vitro. However, it remains unclear whether the beneficial effect of SIRT1 is related to autophagy induction and the underlying mechanism of this effect is also unknown. In the present study, caecal ligation and puncture (CLP)-induced mice, and an LPS-challenged HK-2 cell line were established to mimic a SAKI animal model and a SAKI cell model, respectively. Our results demonstrated that SIRT1 activation promoted autophagy and attenuated SAKI. SIRT1 deacetylated only Beclin1 but not the other autophagy-related proteins in SAKI. SIRT1-induced autophagy and its protective effect against SAKI were mediated by the deacetylation of Beclin1 at K430 and K437. Moreover, two SIRT1 activators, resveratrol and polydatin, attenuated SAKI in CLP-induced septic mice. Our study was the first to demonstrate the important role of SIRT1-induced Beclin1 deacetylation in autophagy and its protective effect against SAKI. These findings suggest that pharmacologic induction of autophagy via SIRT1-mediated Beclin1 deacetylation may be a promising therapeutic approach for future SAKI treatment.

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

Nature Communications ◽

10.1038/s41467-021-23320-8 ◽

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.

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