scholarly journals Bioactive Hydrogel Microcapsules for Guiding Stem Cell Fate Decisions by Release and Reloading of Growth Factors

2021 ◽  
Author(s):  
Alexander Revzin ◽  
Kihak Gwon ◽  
HyeJin Hong ◽  
Alan M Gonzalez-Suarez ◽  
Michael Q Slama ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Growth Factor ◽  
Cell Fate ◽  
Transforming Growth Factor ◽  
Axial Flow ◽  
Cell Phenotype ◽  
Standard Protocol ◽  
Cell Fate Decisions ◽  
Aqueous Core

Human pluripotent stem cells (hPSC) hold considerable promise as a source of adult cells for treatment of diseases ranging from diabetes to liver failure. Some of the challenges that limit the clinical/translational impact of hPSCs are high cost and difficulty in scaling-up of existing differentiation protocols. In this paper, we sought to address these challenges through the development of bioactive microcapsules. A co-axial flow focusing microfluidic device was used to encapsulate hPSCs in microcapsules comprised of an aqueous core and a hydrogel shell. Importantly, the shell contained heparin moieties for growth factor (GF) binding and release. The aqueous core enabled rapid aggregation of hPSCs into 3D spheroids while the bioactive hydrogel shell was used to load inductive cues driving pluripotency maintenance and endodermal differentiation. Specifically, we demonstrated that one-time 1h long loading of pluripotency signals, fibroblast growth factor (FGF)-2 and transforming growth factor (TGF)-β1, into bioactive microcapsules was sufficient to induce and maintain pluripotency of hPSCs over the course of 5 days at levels similar to or better than a standard protocol with soluble GFs. Furthermore, stem cell-carrying microcapsules that previously contained pluripotency signals could be reloaded with an endodermal cue, Nodal, resulting in higher levels of endodermal markers compared to stem cells differentiated in a standard protocol. Overall, bioactive heparin-containing core-shell microcapsules decreased GF usage five-fold while improving stem cell phenotype and are well suited for 3D cultivation of hPSCs.

scholarly journals Runx1 downregulates stem cell and megakaryocytic transcription programs that support niche interactions

Blood ◽  
2016 ◽  
Vol 127 (26) ◽  
pp. 3369-3381 ◽  
Author(s):  
Kira Behrens ◽  
Ioanna Triviai ◽  
Maike Schwieger ◽  
Nilgün Tekin ◽  
Malik Alawi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Stem Cell ◽  
Cell Adhesion ◽  
Cell Fate ◽  
Bone Marrow Niche ◽  
Cell Fate Decisions ◽  
Multipotent Progenitors ◽  
Key Points

Key Points Runx1 is a key determinant of megakaryocyte cell-fate decisions in multipotent progenitors. Runx1 downregulates cell-adhesion factors that promote residency of stem cells and megakaryocytes in their bone marrow niche.

scholarly journals Wnt-inhibitory factor 1 dysregulation of the bone marrow niche exhausts hematopoietic stem cells

Blood ◽  
2011 ◽  
Vol 118 (9) ◽  
pp. 2420-2429 ◽  
Author(s):  
Christoph Schaniel ◽  
Dario Sirabella ◽  
Jiajing Qiu ◽  
Xiaohong Niu ◽  
Ihor R. Lemischka ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Wnt Signaling ◽  
Cell Fate ◽  
Sonic Hedgehog ◽  
Hematopoietic Stem ◽  
Cell Fate Decisions ◽  
Cell Niche ◽  
Wnt Inhibitory Factor 1 ◽  
Stem Cell Pool

Abstract The role of Wnt signaling in hematopoietic stem cell fate decisions remains controversial. We elected to dysregulate Wnt signaling from the perspective of the stem cell niche by expressing the pan Wnt inhibitor, Wnt inhibitory factor 1 (Wif1), specifically in osteoblasts. Here we report that osteoblastic Wif1 overexpression disrupts stem cell quiescence, leading to a loss of self-renewal potential. Primitive stem and progenitor populations were more proliferative and elevated in bone marrow and spleen, manifesting an impaired ability to maintain a self-renewing stem cell pool. Exhaustion of the stem cell pool was apparent only in the context of systemic stress by chemotherapy or transplantation of wild-type stem cells into irradiated Wif1 hosts. Paradoxically this is mediated, at least in part, by an autocrine induction of canonical Wnt signaling in stem cells on sequestration of Wnts in the environment. Additional signaling pathways are dysregulated in this model, primarily activated Sonic Hedgehog signaling in stem cells as a result of Wif1-induced osteoblastic expression of Sonic Hedgehog. We find that dysregulation of the stem cell niche by overexpression of an individual component impacts other unanticipated regulatory pathways in a combinatorial manner, ultimately disrupting niche mediated stem cell fate decisions.

PRECONDITIONING MESENCHYMAL STEM CELLS WITH TRANSFORMING GROWTH FACTOR-ALPHA IMPROVES MESENCHYMAL STEM CELL-MEDIATED CARDIOPROTECTION

Shock ◽  
2010 ◽  
Vol 33 (1) ◽  
pp. 24-30 ◽  
Author(s):  
Jeremy L. Herrmann ◽  
Yue Wang ◽  
Aaron M. Abarbanell ◽  
Brent R. Weil ◽  
Jiangning Tan ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Stem Cell ◽  
Growth Factor ◽  
Mesenchymal Stem Cell ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Alpha ◽  
Factor Alpha

Epigenetic regulation in stem cell development, cell fate conversion, and reprogramming

2015 ◽  
Vol 6 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Kazuyuki Ohbo ◽  
Shin-ichi Tomizawa
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Transcription Factors ◽  
Cell Fate ◽  
Cell Lines ◽  
Cell Fate Decisions ◽  
Micro Rnas ◽  
Stem Cell Lines ◽  
Cell Fate Conversion

AbstractStem cells are identified classically by an in vivo transplantation assay plus additional characterization, such as marker analysis, linage-tracing and in vitro/ex vivo differentiation assays. Stem cell lines have been derived, in vitro, from adult tissues, the inner cell mass (ICM), epiblast, and male germ stem cells, providing intriguing insight into stem cell biology, plasticity, heterogeneity, metastable state, and the pivotal point at which stem cells irreversibly differentiate to non-stem cells. During the past decade, strategies for manipulating cell fate have revolutionized our understanding about the basic concept of cell differentiation: stem cell lines can be established by introducing transcription factors, as with the case for iPSCs, revealing some of the molecular interplay of key factors during the course of phenotypic changes. In addition to de-differentiation approaches for establishing stem cells, another method has been developed whereby induced expression of certain transcription factors and/or micro RNAs artificially converts differentiated cells from one committed lineage to another; notably, these cells need not transit through a stem/progenitor state. The molecular cues guiding such cell fate conversion and reprogramming remain largely unknown. As differentiation and de-differentiation are directly linked to epigenetic changes, we overview cell fate decisions, and associated gene and epigenetic regulations.

scholarly journals GDF11 enhances therapeutic functions of mesenchymal stem cells for angiogenesis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chi Zhang ◽  
Yinuo Lin ◽  
Ke Zhang ◽  
Luyang Meng ◽  
Xinyang Hu ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Stem Cell ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Lentiviral Vector ◽  
Retention Rate ◽  
Antibody Array ◽  
Mouse Bone Marrow ◽  
Control Mscs

Abstract Background The efficacy of stem cell therapy for ischemia repair has been limited by low cell retention rate. Growth differentiation factor 11 (GDF11) is a member of the transforming growth factor-β super family, which has multiple effects on development, physiology and diseases. The objective of the study is to investigate whether GDF11 could affect the efficacy of stem cell transplantation. Methods We explored the effects of GDF11 on proangiogenic activities of mesenchymal stem cells (MSCs) for angiogenic therapy in vitro and in vivo. Results Mouse bone marrow-derived MSCs were transduced with lentiviral vector to overexpress GDF11 (MSCGDF11). After exposed to hypoxia and serum deprivation for 48 h, MSCGDF11 were significantly better in viability than control MSCs (MSCvector). MSCGDF11 also had higher mobility and better angiogenic paracrine effects. The cytokine antibody array showed more angiogenic cytokines in the conditioned medium of MSCGDF11 than that of MSCvector, such as epidermal growth factor, platelet-derived growth factor-BB, placenta growth factor. When MSCs (1 × 106 cells in 50 μl) were injected into ischemic hindlimb of mice after femoral artery ligation, MSCGDF11 had higher retention rate in the muscle than control MSCs. Injection of MSCGDF11 resulted in better blood reperfusion and limb salvage than that of control MSCs after 14 days. Significantly more CD31+ endothelial cells and α-SMA + smooth muscle cells were detected in the ischemic muscles that received MSCGDF11. The effects of GDF11 were through activating TGF-β receptor and PI3K/Akt signaling pathway. Conclusion Our study demonstrated an essential role of GDF11 in promoting therapeutic functions of MSCs for ischemic diseases by enhancing MSC viability, mobility, and angiogenic paracrine functions.

scholarly journals Encapsulation and recovery of murine hematopoietic stem and progenitor cells in a thiol-crosslinked maleimide-functionalized gelatin hydrogel

2021 ◽  
Author(s):  
Aidan E Gilchrist ◽  
Julio F. Serrano ◽  
Mai T. Ngo ◽  
Zona Hrnjak ◽  
Sanha Kim ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Click Reaction ◽  
Uv Light ◽  
3D Culture ◽  
Bone Marrow Niche ◽  
Hematopoietic Stem ◽  
Cell Fate Decisions

Biomaterial platforms are an integral part of stem cell biomanufacturing protocols. The collective biophysical, biochemical, and cellular cues of the stem cell niche microenvironment play an important role in regulating stem cell fate decisions. Three-dimensional (3D) culture of stem cells within biomaterials provides a route to present biophysical and biochemical stimuli such as cell-matrix interactions and cell-cell interactions via secreted biomolecules. Herein, we describe a maleimide-functionalized gelatin (GelMAL) hydrogel that can be crosslinked via thiol-Michael addition click reaction for the encapsulation of sensitive stem cell populations. The maleimide functional units along the gelatin backbone enables gelation via the addition of a dithiol crosslinker without requiring external stimuli (e.g., UV light, photoinitiator), reducing reactive oxide species generation. Additionally, the versatility of crosslinker selection enables easy insertion of thiol-containing bioactive or bioinert motifs. Hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs) were encapsulated in GelMAL, with mechanical properties tuned to mimic the in vivo bone marrow niche. We report insertion of a cleavable peptide crosslinker that can be degraded by the proteolytic action of SortaseA, a mammalian-inert enzyme. Notably, SortaseA exposure preserves stem cell surface markers, an essential metric of hematopoietic activity used in immunophenotyping. This novel GelMAL system enables a route to producing artificial stem cell niches with tunable biophysical properties with intrinsic cell-interaction motifs and orthogonal addition of bioactive crosslinks.

scholarly journals Development of an Inexpensive Raman-Compatible Substrate for the Construction of a Microarray Screening Platform

2020 ◽  
Author(s):  
Isamar Pastrana-Otero ◽  
Sayani Majumdar ◽  
Aidan E. Gilchrist ◽  
Brittney L. Gorman ◽  
Brendan A. C. Harley ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Living Cells ◽  
Raman Microspectroscopy ◽  
Partial Least Square ◽  
Hematopoietic Stem ◽  
Stem Cell Fate ◽  
Cell Fate Decisions ◽  
Extrinsic Cues

Biomaterial microarrays are being developed to facilitate identifying the extrinsic cues that elicit stem cell fate decisions to self-renew, differentiate and remain quiescent. Raman microspectroscopy, often combined with multivariate analysis techniques such as partial least square-discriminant analysis (PLS-DA), could enable the non-invasive identification of stem cell fate decisions made in response to extrinsic cues presented at specific locations on these microarrays. Because existing biomaterial microarrays are not compatible with Raman microspectroscopy, here, we develop an inexpensive substrate that is compatible with both single-cell Raman spectroscopy and the chemistries that are often used for biomaterial microarray fabrication. Standard deposition techniques were used to fabricate a custom Raman-compatible substrate that supports microarray construction. We validated that spectra from living cells on functionalized polyacrylamide (PA) gels attached to the custom Raman-compatible substrate are comparable to spectra acquired from a more expensive commercially available substrate. We also showed that the spectra acquired from individual living cells on functionalized PA gels attached to our custom substrates were of sufficient quality to enable accurate identification of cell phenotypes using PLS-DA models of the cell spectra. We demonstrated this by using cells from laboratory lines (CHO and transfected CHO cells) as well as adult stem cells that were freshly isolated from mice (long-term and short-term hematopoietic stem cells). The custom Ramancompatible substrate reported herein may be used as an inexpensive substrate for constructing biomaterial microarrays that enable the use of Raman microspectroscopy to non-invasively identify the fate decisions of stem cells in response to extrinsic cues.

Nicotinamide, a Potent SIRT2 Inhibitor, Delays Differentiation of Hematopoietic Progenitor Cells.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4142-4142
Author(s):  
Toni Peled ◽  
Sophie Adi ◽  
Elina Glukhman ◽  
Frida Grynspan ◽  
Arnon Nagler ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cell Fate ◽  
Cell Cultures ◽  
Ex Vivo ◽  
Cell Phenotype ◽  
Type I ◽  
Hematopoietic Stem ◽  
Additional Function ◽  
Base Exchange ◽  
Cell Fate Decisions

Abstract CD38, originally described as a differentiation marker, has emerged as an important multifunctional transmembrane protein. Its most intriguing and well-characterized function is its ability to catalyze the synthesis of cyclic ADP-ribose (cADPR) from NAD. Of particular interest is its presence on the inner membrane of the nucleus, suggesting that CD38/cADPR may play a direct role in mediating nuclear activation and gene expression. Our studies on ex vivo expansion of Hematopoietic Stem Cells (HSCs) have led us to test whether alteration of CD38 function carries the potential of affecting cell fate decisions of HSCs. Inhibition of CD38 enzymatic activity was achieved by treating CD34+ cell cultures with nicotinamide (NA), a well-known base-exchange inhibitor demonstrated to inhibit the synthesis of cADPR from NAD. We report here that exogenously added nicotinamide (5–10 mM) to CD34+ cell cultures supplemented with cytokines (SCF, TPO, IL-6, FLt3, +/− IL-3) resulted in significant enrichment of CD34+CD38− (79±9.3%, n=9) and CD34+CD38−Lin− (19±3%, n=8) cells, as compared with control cultures treated only with cytokines (6.3±1.8%, n=9, and 0.7±0.06%, n=8, respectively, p<0.01). The functionality of these early progenitor subsets was demonstrated using the extended LTC-CFC assay, performed in the absence of NA. These results raised the intriguing possibility that cADPR production may have a pivotal role in regulation of CD34+ cell fate. However, inhibition of cADPR downstream signal transduction pathways by its specific antagonist, 8-amino-cADPR did not yield any effect on CD34+ cell cultures, excluding the possibility that nicotinamide modulates CD34+ cell fate solely by inhibition of cADPR synthesis. Nicotinamide is also a well-known potent inhibitor of SIRT2, a unique NAD(+)-dependent type III histone deacetylase (HDAC) with mono-ADP-ribosyltransferase activity involved in gene silencing, metabolism, apoptosis and aging. NA blocks NAD(+) hydrolysis by binding to an adjacent conserved pocket, and is therefore suggested as the physiologically relevant regulator of SIRT2 enzymes. This additional function of nicotinamide raises the intriguing possibility that HSC enrichment achieved by nicotinamide treatment may be related to specific inhibition of SIRT2 deacetylase activity and modulation of chromatin architecture leading to re-activation of previously silenced genes. In line with this hypothesis, Milhem et all. recently reported that addition of trichostatin A, a specific HDAC (type I and II) inhibitor, along with a DNA hypomethylating agent, modulated HSC fate ex vivo resulting in the retention of stem cell phenotype, number, and function (Blood, 2004; 103; 4102). Ongoing work is aimed at elucidating whether inhibition of SIRT2 is specifically involved in NA mechanism of activity leading to modulation of hematopoietic stem cell fate in ex vivo conditions.

scholarly journals The Intracellular Form of Notch Blocks Transforming Growth Factor β-Mediated Growth Arrest in Mv1Lu Epithelial Cells

2003 ◽  
Vol 23 (18) ◽  
pp. 6694-6701 ◽  
Author(s):  
Prakash Rao ◽  
Tom Kadesch
Keyword(s):  
Cell Cycle ◽  
Growth Factor ◽  
Cell Growth ◽  
Epithelial Cells ◽  
Cell Fate ◽  
Transforming Growth Factor ◽  
Cell Cycle Control ◽  
Transforming Growth Factor Β ◽  
Cell Fate Decisions ◽  
Growth Inhibitory

ABSTRACT Notch signaling influences a variety of cell fate decisions during development, and constitutive activation of the pathway can provoke unbridled cell growth and cancer. The mechanisms by which Notch affects cell growth are not well established. We describe here a novel link between Notch and cell cycle control. We found that Mv1Lu epithelial cells harboring an oncogenic form of Notch (NICD) are resistant to the cell cycle-inhibitory effects of transforming growth factor β (TGF-β). NICD did not affect TGF-β signaling per se but blocked induction of the Cdk inhibitor p15INK4B. c-Myc, whose down-regulation by TGF-β is required for p15INK4B induction, remained elevated in the NICD-expressing cells. c-Myc expression was also maintained in low serum, indicating that Notch's effects on c-Myc are not specific to TGF-β. Our results are consistent with a model in which a strong Notch signal indirectly deregulates c-Myc expression and thereby renders Mv1Lu epithelial cells resistant to growth-inhibitory signals.

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