scholarly journals Synthetic Extracellular Microenvironment for Modulating Stem Cell Behaviors

2015 ◽  
Vol 10s1 ◽  
pp. BMI.S20057 ◽  
Author(s):  
Prafulla Chandra ◽  
Sang Jin Lee
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Bioactive Molecules ◽  
Stem Cell Fate ◽  
Cell Behaviors ◽  
Extracellular Microenvironment ◽  
Promising Source

The innate ability of stem cells to self-renew and differentiate into multiple cell types makes them a promising source for tissue engineering and regenerative medicine applications. Their capacity for self-renewal and differentiation is largely influenced by the combination of physical, chemical, and biological signals found in the stem cell niche, both temporally and spatially. Embryonic and adult stem cells are potentially useful for cell-based approaches; however, regulating stem cell behavior remains a major challenge in their clinical use. Most of the current approaches for controlling stem cell fate do not fully address all of the complex signaling pathways that drive stem cell behaviors in their natural microenvironments. To overcome this limitation, a new generation of biomaterials is being developed for use as three-dimensional synthetic microenvironments that can mimic the regulatory characteristics of natural extracellular matrix (ECM) proteins and ECM-bound growth factors. These synthetic microenvironments are currently being investigated as a substrate with surface immobilization and controlled release of bioactive molecules to direct the stem cell fate in vitro, as a tissue template to guide and improve the neo-tissue formation both in vitro and in vivo, and as a delivery vehicle for cell therapy in vivo. The continued advancement of such an intelligent biomaterial system as the synthetic extracellular microenvironment holds the promise of improved therapies for numerous debilitating medical conditions for which no satisfactory cure exists today.

Constructing stem cell microenvironments using bioengineering approaches

2013 ◽  
Vol 45 (23) ◽  
pp. 1123-1135 ◽  
Author(s):  
David A. Brafman
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Disease Modeling ◽  
Mechanical Stimuli ◽  
Culture Methods ◽  
Stem Cell Fate ◽  
And Function

Within the adult organism, stem cells reside in defined anatomical microenvironments called niches. These architecturally diverse microenvironments serve to balance stem cell self-renewal and differentiation. Proper regulation of this balance is instrumental to tissue repair and homeostasis, and any imbalance can potentially lead to diseases such as cancer. Within each of these microenvironments, a myriad of chemical and physical stimuli interact in a complex (synergistic or antagonistic) manner to tightly regulate stem cell fate. The in vitro replication of these in vivo microenvironments will be necessary for the application of stem cells for disease modeling, drug discovery, and regenerative medicine purposes. However, traditional reductionist approaches have only led to the generation of cell culture methods that poorly recapitulate the in vivo microenvironment. To that end, novel engineering and systems biology approaches have allowed for the investigation of the biological and mechanical stimuli that govern stem cell fate. In this review, the application of these technologies for the dissection of stem cell microenvironments will be analyzed. Moreover, the use of these engineering approaches to construct in vitro stem cell microenvironments that precisely control stem cell fate and function will be reviewed. Finally, the emerging trend of using high-throughput, combinatorial methods for the stepwise engineering of stem cell microenvironments will be explored.

scholarly journals Regulation and Directing Stem Cell Fate by Tissue Engineering Functional Microenvironments: Scaffold Physical and Chemical Cues

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Fei Xing ◽  
Lang Li ◽  
Changchun Zhou ◽  
Cheng Long ◽  
Lina Wu ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Stem Cells ◽  
Stem Cell ◽  
Growth Factors ◽  
Cell Fate ◽  
Chemical Cues ◽  
Physical Factors ◽  
Stem Cell Fate ◽  
Physical And Chemical

It is well known that stem cells reside within tissue engineering functional microenvironments that physically localize them and direct their stem cell fate. Recent efforts in the development of more complex and engineered scaffold technologies, together with new understanding of stem cell behavior in vitro, have provided a new impetus to study regulation and directing stem cell fate. A variety of tissue engineering technologies have been developed to regulate the fate of stem cells. Traditional methods to change the fate of stem cells are adding growth factors or some signaling pathways. In recent years, many studies have revealed that the geometrical microenvironment played an essential role in regulating the fate of stem cells, and the physical factors of scaffolds including mechanical properties, pore sizes, porosity, surface stiffness, three-dimensional structures, and mechanical stimulation may affect the fate of stem cells. Chemical factors such as cell-adhesive ligands and exogenous growth factors would also regulate the fate of stem cells. Understanding how these physical and chemical cues affect the fate of stem cells is essential for building more complex and controlled scaffolds for directing stem cell fate.

Directing Stem Cell Fate in 3D Through Cell Inert and Adhesive Diblock Copolymer Domains

2013 ◽  
Author(s):  
Somyot Chirasatitsin ◽  
Priyalakshmi Viswanathan ◽  
Giuseppe Battaglia ◽  
Adam J. Engler
Keyword(s):  
Extracellular Matrix ◽  
Stem Cell ◽  
Cell Adhesion ◽  
Cell Fate ◽  
Diblock Copolymer ◽  
Stem Cell Differentiation ◽  
Stem Cell Fate ◽  
Cell Behaviors ◽  
Cell Structures

Adhesions are important cell structures required to transduce a variety of chemical and mechanics signals from outside-in and vice versa, all of which regulate cell behaviors, including stem cell differentiation (1). Though most biomaterials are coated with an adhesive ligand to promote adhesion, they do not often have a uniform distribution that does not match the heterogeneously adhesive extracellular matrix (ECM) in vivo (2). We have previously shown that diblock copolymer (DBC) mixtures undergo interface-confined de-mixing to form nanodomins of one copolymer in another (3). Here we demonstrate how diblock copolymer mixtures can be made into foams with nanodomains to better recapitulate native ECM adhesion regions and influence cell adhesion.

scholarly journals Alternative polyadenylation of Pax3 controls muscle stem cell fate and muscle function

Science ◽  
2019 ◽  
Vol 366 (6466) ◽  
pp. 734-738 ◽  
Author(s):  
Antoine de Morree ◽  
Julian D. D. Klein ◽  
Qiang Gan ◽  
Jean Farup ◽  
Andoni Urtasun ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Messenger Rna ◽  
Adult Stem Cells ◽  
Alternative Polyadenylation ◽  
Quiescent State ◽  
Stem Cell Fate ◽  
Activation Rate

Adult stem cells are essential for tissue homeostasis. In skeletal muscle, muscle stem cells (MuSCs) reside in a quiescent state, but little is known about the mechanisms that control homeostatic turnover. Here we show that, in mice, the variation in MuSC activation rate among different muscles (for example, limb versus diaphragm muscles) is determined by the levels of the transcription factor Pax3. We further show that Pax3 levels are controlled by alternative polyadenylation of its transcript, which is regulated by the small nucleolar RNA U1. Isoforms of the Pax3 messenger RNA that differ in their 3′ untranslated regions are differentially susceptible to regulation by microRNA miR206, which results in varying levels of the Pax3 protein in vivo. These findings highlight a previously unrecognized mechanism of the homeostatic regulation of stem cell fate by multiple RNA species.

scholarly journals Effect of the 3D Artificial Nichoid on the Morphology and Mechanobiological Response of Mesenchymal Stem Cells Cultured In Vitro

Cells ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1873 ◽  
Author(s):  
Andrea Remuzzi ◽  
Barbara Bonandrini ◽  
Matteo Tironi ◽  
Lorena Longaretti ◽  
Marina Figliuzzi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Cultured Cells ◽  
Three Dimensions ◽  
Nuclear Pore ◽  
Cells Cultured

Stem cell fate and behavior are affected by the bidirectional communication of cells and their local microenvironment (the stem cell niche), which includes biochemical cues, as well as physical and mechanical factors. Stem cells are normally cultured in conventional two-dimensional monolayer, with a mechanical environment very different from the physiological one. Here, we compare culture of rat mesenchymal stem cells on flat culture supports and in the “Nichoid”, an innovative three-dimensional substrate micro-engineered to recapitulate the architecture of the physiological niche in vitro. Two versions of the culture substrates Nichoid (single-layered or “2D Nichoid” and multi-layered or “3D Nichoid”) were fabricated via two-photon laser polymerization in a biocompatible hybrid organic-inorganic photoresist (SZ2080). Mesenchymal stem cells, isolated from rat bone marrow, were seeded on flat substrates and on 2D and 3D Nichoid substrates and maintained in culture up to 2 weeks. During cell culture, we evaluated cell morphology, proliferation, cell motility and the expression of a panel of 89 mesenchymal stem cells’ specific genes, as well as intracellular structures organization. Our results show that mesenchymal stem cells adhered and grew in the 3D Nichoid with a comparable proliferation rate as compared to flat substrates. After seeding on flat substrates, cells displayed large and spread nucleus and cytoplasm, while cells cultured in the 3D Nichoid were spatially organized in three dimensions, with smaller and spherical nuclei. Gene expression analysis revealed the upregulation of genes related to stemness and to mesenchymal stem cells’ features in Nichoid-cultured cells, as compared to flat substrates. The observed changes in cytoskeletal organization of cells cultured on 3D Nichoids were also responsible for a different localization of the mechanotransducer transcription factor YAP, with an increase of the cytoplasmic retention in cells cultured in the 3D Nichoid. This difference could be explained by alterations in the import of transcription factors inside the nucleus due to the observed decrease of mean nuclear pore diameter, by transmission electron microscopy. Our data show that 3D distribution of cell volume has a profound effect on mesenchymal stem cells structure and on their mechanobiological response, and highlight the potential use of the 3D Nichoid substrate to strengthen the potential effects of MSC in vitro and in vivo.

An RNA Interference Screen Identifies the Cell Fate Determinants Msi2 and Prox1 as Novel Regulators of Hematopoietic Stem Cell Self-Renewal.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 394-394
Author(s):  
Kristin J Hope ◽  
Sonia Cellot ◽  
Stephen Ting ◽  
Guy Sauvageau
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Control Shrna ◽  
Fate Determinants ◽  
Cell Fate Determinants

Abstract Abstract 394 Hematopoietic stem cells (HSC) can not yet be unambiguously prospectively identified, a fact which has made it difficult to determine whether a segregation of cell fate determinants underlies the asymmetric/symmetric self-renewal of these cells or whether deregulation of such determinants could contribute to the pathogenesis of hematopoietic malignancies by inducing constitutive symmetric self-renewal divisions. We have addressed these questions through a functional genetics approach taking advantage of systematic RNAi to evaluate the function of conserved polarity factors and cell fate determinants in HSCs. From a list of 72 of such factors identified in the literature, 30 murine homologues were chosen based on their differentially higher level of expression in HSC-enriched populations as measured by qRT-PCR. For each candidate we designed 3 unique short hairpin RNA (shRNA) encoding retroviral constructs also carrying EGFP for the purposes of following transduced cells. Primitive hematopoietic cells enriched for HSC were infected at high efficiency with the library in an arrayed 96-well format and their in vivo reconstituting potential was then evaluated through competitive repopulating unit assays. Genes for which shRNA vectors altered late transplant EGFP levels below or above thresholds as defined by a control shRNA to luciferase were considered as hits. Using this approach, we identified and comprehensively validated 4 genes, including the RNA binding protein Msi2, for which shRNA-mediated depletion dramatically impairs repopulation but does not induce cell death or a cell cycle block. Importantly, we show that the loss in the repopulating ability of these shRNA transduced cells is mediated at the stem cell level and is not due to progenitor or downstream cell toxicity or to any defect in the process of bone marrow homing. Subsequent expression profiling indicated that Msi2 is also upregulated in HOXB4-overexpressing symmetrically expanding HSC in line with our findings that it functions as a positive HSC regulator and further suggesting that it represents a potential novel HSC marker. As well as finding HSC agonists, the RNAi screen identified the homeodomain containing transcription factor Prox1 as a negative HSC regulator since its shRNA-mediated transcript loss consistently led to the dramatic in vivo accumulation of EGFP+ transduced cells. Grafts comprised of Prox1 shRNA-transduced cells did not exhibit any lineage skewing however, repeatedly contained an average of 10-fold more primitive Lin-Sca+CD150+48- cells as compared to non-transduced donor cells within the same recipient or to control shRNA-luciferase grafts indicating Prox1 knockdown leads to a significant in vivo expansion of phenotypic HSCs. Moreover, following a 7 day in vitro culture, cells infected with shRNAs to Prox1 were both morphologically and immunophenotypically more primitive than control cells and when transplanted at this time yielded a significantly enhanced engraftment level relative to control shRNAs (51+/-6% GFP vs 8+/-3% GFP). These results further suggest that Prox1 reduction by RNAi expands functional HSCs in vitro. Together these findings have identified conserved cell fate determinants as important and novel regulators of murine hematopoietic stem cells. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Advances in Extracellular Matrix-Mimetic Hydrogels to Guide Stem Cell Fate

2021 ◽  
pp. 1-18
Author(s):  
Ryan S. Stowers
Keyword(s):  
Stem Cells ◽  
Extracellular Matrix ◽  
Stem Cell ◽  
Cell Fate ◽  
Cell Biology ◽  
Stem Cell Differentiation ◽  
Stem Cell Biology ◽  
Stem Cell Fate ◽  
Material Systems

In the fields of regenerative medicine and tissue engineering, stem cells offer vast potential for treating or replacing diseased and damaged tissue. Much progress has been made in understanding stem cell biology, yielding protocols for directing stem cell differentiation toward the cell type of interest for a specific application. One particularly interesting and powerful signaling cue is the extracellular matrix (ECM) surrounding stem cells, a network of biopolymers that, along with cells, makes up what we define as a tissue. The composition, structure, biochemical features, and mechanical properties of the ECM are varied in different tissues and developmental stages, and serve to instruct stem cells toward a specific lineage. By understanding and recapitulating some of these ECM signaling cues through engineered ECM-mimicking hydrogels, stem cell fate can be directed in vitro. In this review, we will summarize recent advances in material systems to guide stem cell fate, highlighting innovative methods to capture ECM functionalities and how these material systems can be used to provide basic insight into stem cell biology or make progress toward therapeutic objectives.

scholarly journals Arginine Methylation by PRMT1 Regulates Muscle Stem Cell Fate

2016 ◽  
Vol 37 (3) ◽  
Author(s):  
Roméo Sébastien Blanc ◽  
Gillian Vogel ◽  
Xing Li ◽  
Zhenbao Yu ◽  
Shawn Li ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cell Fate ◽  
Muscle Regeneration ◽  
Myogenic Differentiation ◽  
Arginine Methylation ◽  
Muscle Stem Cell ◽  
Stem Cell Fate ◽  
Protein Arginine Methyltransferase 1

ABSTRACT Quiescent muscle stem cells (MSCs) become activated in response to skeletal muscle injury to initiate regeneration. Activated MSCs proliferate and differentiate to repair damaged fibers or self-renew to maintain the pool and ensure future regeneration. The balance between self-renewal, proliferation, and differentiation is a tightly regulated process controlled by a genetic cascade involving determinant transcription factors such as Pax7, Myf5, MyoD, and MyoG. Recently, there have been several reports about the role of arginine methylation as a requirement for epigenetically mediated control of muscle regeneration. Here we report that the protein arginine methyltransferase 1 (PRMT1) is expressed in MSCs and that conditional ablation of PRMT1 in MSCs using Pax7CreERT2 causes impairment of muscle regeneration. Importantly, PRMT1-deficient MSCs have enhanced cell proliferation after injury but are unable to terminate the myogenic differentiation program, leading to regeneration failure. We identify the coactivator of Six1, Eya1, as a substrate of PRMT1. We show that PRMT1 methylates Eya1 in vitro and that loss of PRMT1 function in vivo prevents Eya1 methylation. Moreover, we observe that PRMT1-deficient MSCs have reduced expression of Eya1/Six1 target MyoD due to disruption of Eya1 recruitment at the MyoD promoter and subsequent Eya1-mediated coactivation. These findings suggest that arginine methylation by PRMT1 regulates muscle stem cell fate through the Eya1/Six1/MyoD axis.

scholarly journals Roles of MicroRNAs in Establishing and Modulating Stem Cell Potential

2019 ◽  
Vol 20 (15) ◽  
pp. 3643 ◽  
Author(s):  
Zhenwu Zhang ◽  
Lili Zhuang ◽  
Chao-Po Lin
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Embryonic Development ◽  
Cell Fate ◽  
Noncoding Rnas ◽  
Small Interfering Rnas ◽  
Cell Potential ◽  
Early Embryos

Early embryonic development in mammals, from fertilization to implantation, can be viewed as a process in which stem cells alternate between self-renewal and differentiation. During this process, the fates of stem cells in embryos are gradually specified, from the totipotent state, through the segregation of embryonic and extraembryonic lineages, to the molecular and cellular defined progenitors. Most of those stem cells with different potencies in vivo can be propagated in vitro and recapitulate their differentiation abilities. Complex and coordinated regulations, such as epigenetic reprogramming, maternal RNA clearance, transcriptional and translational landscape changes, as well as the signal transduction, are required for the proper development of early embryos. Accumulated studies suggest that Dicer-dependent noncoding RNAs, including microRNAs (miRNAs) and endogenous small-interfering RNAs (endo-siRNAs), are involved in those regulations and therefore modulate biological properties of stem cells in vitro and in vivo. Elucidating roles of these noncoding RNAs will give us a more comprehensive picture of mammalian embryonic development and enable us to modulate stem cell potencies. In this review, we will discuss roles of miRNAs in regulating the maintenance and cell fate potential of stem cells in/from mouse and human early embryos.

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