scholarly journals Triple Staining Including FOXA2 Identifies Stem Cell Lineages Undergoing Hepatic and Biliary Differentiation in Cirrhotic Human Liver

2016 ◽  
Vol 65 (1) ◽  
pp. 33-46 ◽  
Author(s):  
Charles E. Rogler ◽  
Remon Bebawee ◽  
Joe Matarlo ◽  
Joseph Locker ◽  
Nicole Pattamanuch ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Human Liver ◽  
Bile Ducts ◽  
Cytokeratin 19 ◽  
Oval Cells ◽  
Cell Fate Decisions ◽  
Cell Lineages ◽  
End Stage

Recent investigations have reported many markers associated with human liver stem/progenitor cells, “oval cells,” and identified “niches” in diseased livers where stem cells occur. However, there has remained a need to identify entire lineages of stem cells as they differentiate into bile ducts or hepatocytes. We have used combined immunohistochemical staining for a marker of hepatic commitment and specification (FOXA2 [Forkhead box A2]), hepatocyte maturation (Albumin and HepPar1), and features of bile ducts (CK19 [cytokeratin 19]) to identify lineages of stem cells differentiating toward the hepatocytic or bile ductular compartments of end-stage cirrhotic human liver. We identified large clusters of disorganized, FOXA2 expressing, oval cells in localized liver regions surrounded by fibrotic matrix, designated as “micro-niches.” Specific FOXA2-positive cells within the micro-niches organize into primitive duct structures that support both hepatocytic and bile ductular differentiation enabling identification of entire lineages of cells forming the two types of structures. We also detected expression of hsa-miR-122 in primitive ductular reactions expected for hepatocytic differentiation and hsa-miR-23b cluster expression that drives liver cell fate decisions in cells undergoing lineage commitment. Our data establish the foundation for a mechanistic hypothesis on how stem cell lineages progress in specialized micro-niches in cirrhotic end-stage liver disease.

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.

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 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.

scholarly journals Mitochondrial Control of Stem Cell State and Fate: Lessons From Drosophila

2021 ◽  
Vol 9 ◽  
Author(s):  
Satish Kumar Tiwari ◽  
Sudip Mandal
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Cell Types ◽  
Extrinsic Factors ◽  
Cell Fate Decisions ◽  
Cell State ◽  
Resident Stem Cells ◽  
Stem Cell State

Over the years, Drosophila has served as a wonderful genetically tractable model system to unravel various facets of tissue-resident stem cells in their microenvironment. Studies in different stem and progenitor cell types of Drosophila have led to the discovery of cell-intrinsic and extrinsic factors crucial for stem cell state and fate. Though initially touted as the ATP generating machines for carrying various cellular processes, it is now increasingly becoming clear that mitochondrial processes alone can override the cellular program of stem cells. The last few years have witnessed a surge in our understanding of mitochondria’s contribution to governing different stem cell properties in their subtissular niches in Drosophila. Through this review, we intend to sum up and highlight the outcome of these in vivo studies that implicate mitochondria as a central regulator of stem cell fate decisions; to find the commonalities and uniqueness associated with these regulatory mechanisms.

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.

scholarly journals Heterochromatin protein 1 promotes self-renewal and triggers regenerative proliferation in adult stem cells

2013 ◽  
Vol 201 (3) ◽  
pp. 409-425 ◽  
Author(s):  
An Zeng ◽  
Yong-Qin Li ◽  
Chen Wang ◽  
Xiao-Shuai Han ◽  
Ge Li ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Adult Stem Cells ◽  
Cell Function ◽  
Heterochromatin Protein 1 ◽  
Self Renewal ◽  
Blastema Formation ◽  
Cell Fate Decisions ◽  
Chromatin Regulators

Adult stem cells (ASCs) capable of self-renewal and differentiation confer the potential of tissues to regenerate damaged parts. Epigenetic regulation is essential for driving cell fate decisions by rapidly and reversibly modulating gene expression programs. However, it remains unclear how epigenetic factors elicit ASC-driven regeneration. In this paper, we report that an RNA interference screen against 205 chromatin regulators identified 12 proteins essential for ASC function and regeneration in planarians. Surprisingly, the HP1-like protein SMED–HP1-1 (HP1-1) specifically marked self-renewing, pluripotent ASCs, and HP1-1 depletion abrogated self-renewal and promoted differentiation. Upon injury, HP1-1 expression increased and elicited increased ASC expression of Mcm5 through functional association with the FACT (facilitates chromatin transcription) complex, which consequently triggered proliferation of ASCs and initiated blastema formation. Our observations uncover an epigenetic network underlying ASC regulation in planarians and reveal that an HP1 protein is a key chromatin factor controlling stem cell function. These results provide important insights into how epigenetic mechanisms orchestrate stem cell responses during tissue regeneration.

scholarly journals Deubiquitinating Enzyme-Mediated Signaling Networks in Cancer Stem Cells

Cancers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3253
Author(s):  
Kamini Kaushal ◽  
Suresh Ramakrishna
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cancer Stem Cells ◽  
Signaling Pathways ◽  
Cell Fate ◽  
Deubiquitinating Enzymes ◽  
Self Renewal ◽  
Stem Cell Fate ◽  
Multiple Tumor ◽  
Cell Fate Decisions

Cancer stem cells (CSCs) have both the capacity for self-renewal and the potential to differentiate and contribute to multiple tumor properties, such as recurrence, metastasis, heterogeneity, multidrug resistance, and radiation resistance. Thus, CSCs are considered to be promising therapeutic targets for cancer therapy. The function of CSCs can be regulated by ubiquitination and deubiquitination of proteins related to the specific stemness of the cells executing various stem cell fate choices. To regulate the balance between ubiquitination and deubiquitination processes, the disassembly of ubiquitin chains from specific substrates by deubiquitinating enzymes (DUBs) is crucial. Several key developmental and signaling pathways have been shown to play essential roles in this regulation. Growing evidence suggests that overactive or abnormal signaling within and among these pathways may contribute to the survival of CSCs. These signaling pathways have been experimentally shown to mediate various stem cell properties, such as self-renewal, cell fate decisions, survival, proliferation, and differentiation. In this review, we focus on the DUBs involved in CSCs signaling pathways, which are vital in regulating their stem-cell fate determination.

scholarly journals Drosophila as a Model for Developmental Biology: Stem Cell-Fate Decisions in the Developing Nervous System

2018 ◽  
Vol 6 (4) ◽  
pp. 25 ◽  
Author(s):  
Katherine Harding ◽  
Kristin White
Keyword(s):  
Stem Cells ◽  
Nervous System ◽  
Stem Cell ◽  
Neural Stem Cells ◽  
Cell Fate ◽  
Cell Behavior ◽  
Stem Cell Fate ◽  
Cell Fate Decisions ◽  
Unique System ◽  
Developing Nervous System

Stem cells face a diversity of choices throughout their lives. At specific times, they may decide to initiate cell division, terminal differentiation, or apoptosis, or they may enter a quiescent non-proliferative state. Neural stem cells in the Drosophila central nervous system do all of these, at stereotypical times and anatomical positions during development. Distinct populations of neural stem cells offer a unique system to investigate the regulation of a particular stem cell behavior, while comparisons between populations can lead us to a broader understanding of stem cell identity. Drosophila is a well-described and genetically tractable model for studying fundamental stem cell behavior and the mechanisms that underlie cell-fate decisions. This review will focus on recent advances in our understanding of the factors that contribute to distinct stem cell-fate decisions within the context of the Drosophila nervous system.

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