scholarly journals Reprogramming of Human Cells to Pluripotency Induces CENP-A Chromatin Depletion

2020 ◽  
Author(s):  
Inês Milagre ◽  
Carolina Pereira ◽  
Raquel Oliveira ◽  
Lars E.T. Jansen
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Pluripotent Stem Cells ◽  
Embryonic Stem ◽  
Physiological Role ◽  
Cell Types ◽  
Human Cells ◽  
Early Event ◽  
Human Stem Cells ◽  
Centromere Function

SummaryPluripotent stem cells (PSCs) are central to development as they are the precursors of all cell types in the embryo. Therefore, maintaining a stable karyotype is essential, both for their physiological role as well as for use in regenerative medicine. In culture, an estimated 10-30% of PSC lines present karyotypic abnormalities, but the underlying causes remain unknown. To gain insight into the mitotic capacity of human embryonic stem cells and induced pluripotent stem cells, we explore the structure of the centromere and kinetochore. Centromere function depends on CENP-A nucleosome-defined chromatin. We show that while PSCs maintain abundant pools of CENP-A, CENP-C and CENP-T, these essential centromere components are strongly reduced at stem cell centromeres. Outer kinetochore recruitment is also impaired to a lesser extent, indicating an overall weaker kinetochore. This impairment is specific for the kinetochore forming centromere complex while the inner centromere protein Aurora B remains unaffected. We further show that, similar to differentiated human cells, CENP-A chromatin assembly in PSCs requires transition into G1 phase. Finally, reprogramming experiments indicate that reduction of centromeric CENP-A levels is an early event during dedifferentiation, coinciding with global chromatin remodelling. Our characterisation of centromeres in human stem cells drives new hypotheses including a possible link between impaired centromere function and stem cell aneuploidies.

scholarly journals Reprogramming of human cells to pluripotency induces CENP-A chromatin depletion

Open Biology ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 200227
Author(s):  
Inês Milagre ◽  
Carolina Pereira ◽  
Raquel A. Oliveira ◽  
Lars E. T. Jansen
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Physiological Role ◽  
Cell Types ◽  
Human Cells ◽  
Early Event ◽  
Human Stem Cells ◽  
Centromere Function ◽  
Underlying Causes

Pluripotent stem cells (PSCs) are central to development as they are the precursors of all cell types in the embryo. Therefore, maintaining a stable karyotype is essential, both for their physiological role as well as for their use in regenerative medicine. Karyotype abnormalities in PSCs in culture are common but the underlying causes remain unknown. To gain insight, we explore the composition of the centromere and kinetochore in human embryonic and induced PSCs. Centromere function depends on CENP-A nucleosome-defined chromatin. We show that while PSCs maintain abundant pools of CENP-A, CENP-C and CENP-T, these essential centromere components are strongly reduced at stem cell centromeres. Outer kinetochore recruitment is also impaired to a lesser extent, indicating an overall weaker kinetochore while the inner centromere protein Aurora B remains unaffected. We further show that, similar to differentiated human cells, CENP-A chromatin assembly in PSCs requires transition into G1 phase. Finally, reprogramming experiments indicate that reduction of centromeric CENP-A levels is an early event during dedifferentiation, coinciding with global chromatin remodelling. Our characterization of centromeres in human stem cells suggests a possible link between impaired centromere function and stem cell aneuploidies.

scholarly journals Induced Pluripotent Stem Cells (iPSCs) in Vascular Research: from Two- to Three-Dimensional Organoids

2021 ◽  
Author(s):  
Anja Trillhaase ◽  
Marlon Maertens ◽  
Zouhair Aherrahrou ◽  
Jeanette Erdmann
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Induced Pluripotent Stem Cells ◽  
Stem Cell Research ◽  
Pluripotent Stem Cells ◽  
Embryonic Stem ◽  
Cell Types ◽  
3D Models ◽  
Induced Pluripotent

AbstractStem cell technology has been around for almost 30 years and in that time has grown into an enormous field. The stem cell technique progressed from the first successful isolation of mammalian embryonic stem cells (ESCs) in the 1990s, to the production of human induced-pluripotent stem cells (iPSCs) in the early 2000s, to finally culminate in the differentiation of pluripotent cells into highly specialized cell types, such as neurons, endothelial cells (ECs), cardiomyocytes, fibroblasts, and lung and intestinal cells, in the last decades. In recent times, we have attained a new height in stem cell research whereby we can produce 3D organoids derived from stem cells that more accurately mimic the in vivo environment. This review summarizes the development of stem cell research in the context of vascular research ranging from differentiation techniques of ECs and smooth muscle cells (SMCs) to the generation of vascularized 3D organoids. Furthermore, the different techniques are critically reviewed, and future applications of current 3D models are reported. Graphical abstract

Concise Review; Effects of Antibiotics and Antimycotics on the Biological Properties of Human Pluripotent and Multipotent Stem Cells

2020 ◽  
Vol 16 ◽  
Author(s):  
Maryam Farzaneh
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Pluripotent Stem Cells ◽  
Disease Modeling ◽  
Culture Media ◽  
Embryonic Stem ◽  
Great Promise ◽  
Human Stem Cells ◽  
Multipotent Stem Cells ◽  
The Impact

Abstract:: Human pluripotent stem cells (PSCs) including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) have the remarkable potential to self-renew and develop into various cell lineages. Human mesenchymal stem cells (MSCs) or multipotent stem cells that are present in various organs can self-renew and differentiate into multiple mesenchymal lineages. Both human PSCs and MSCs hold great promise in cell-based therapies, disease modeling, drug discovery, and regenerative medicine. Human stem cells must be cultured under the optimal conditions to use them in transplantology. Therefore, researchers must ensure the sterility of human stem cell lines. Bacterial contamination is a common problem in laboratories and major precautions are required to detect the types of microorganisms, eliminate, and prevent contamination in cell cultures. Stem cell culture media usually contains antibiotics and antimycotics such as penicillin-streptomycin (pen-strep), gentamicin, and amphotericin B (AmB) to avoid bacterial, fungal, and yeast contaminants. Numerous publications recognized the serious effect of antibiotics and antimycotics on in vitro properties of human stem cells, including proliferation, differentiation, survival, and genetic instability. This review study aimed to understand the impact of routinely used antibiotics and antimycotics such as pen-strep, gentamicin, and AmB on viability, proliferation, and functional properties (differentiation and pluripotency) of human PSCs and MSCs.

scholarly journals Retinal organoids derived from rhesus macaque iPSCs undergo accelerated differentiation compared to human stem cells

2021 ◽  
Author(s):  
Antonio Jacobo Lopez ◽  
Sangbae Kim ◽  
Xinye Qian ◽  
Jeffrey Rogers ◽  
J. Timothy Stout ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Single Cell ◽  
Human Embryonic Stem Cells ◽  
Pluripotent Stem Cells ◽  
Embryonic Stem ◽  
Cell Types ◽  
Human Stem Cells ◽  
Retinal Differentiation ◽  
Optic Vesicles

Purpose: To compare the timing and efficiency of the development of non-human primate (NHP) derived retinal organoids in comparison to those derived from human embryonic stem cells. Methods: Human embryonic stem cells (hESCs) and induced-pluripotent stem cells (rhiPSCs) derived from non-human primates (Macaca mulatta) were differentiated into retinal organoids by using an established differentiation protocol. Briefly, embryoid bodies were formed from pluripotent stem cells and induced into a neural lineage with neural induction media with the addition of BMP4. Thereafter, self-formation of optic vesicles was allowed to form in a 2D culture in retinal differentiation media (RDM). Optic vesicles were then manually harvested and cultured in suspension in 3D-RDM media until analysis. Differences in the timing of differentiation and efficiency of retinal organoid development were assessed by light microscopy, electron microscopy, immunocytochemistry, and single-cell transcriptomics. Results: Generation of retinal organoids was achieved from both human and several NHP pluripotent stem cells lines. All rhiPSC lines resulted in retinal differentiation with the formation of optic vesicle-like structures similar to what has been observed in hESC retinal organoids. NHP retinal organoids had laminated structure and were composed of mature retinal cell types including cone and rod photoreceptors. Single cell RNA sequencing was conducted at two time points, which allowed identification of cell types and characterization of developmental trajectory in the developing organoid. Important differences between rhesus and human cells were measured regarding the timing and efficiency of retinal organoid differentiation. While the culture of NHP-derived iPSCs is relatively difficult compared to human stem cells, the generation of retinal organoids is feasible and may be less time consuming due to an intrinsically faster timing of retinal differentiation. Conclusions: Retinal organoids produced from iPSCs derived from Rhesus monkey using established protocols differentiate through the stages of organoid development faster than those derived from human stem cells. The production of NHP retinal organoids may be advantageous to reduce experimental time and cost for basic biology studies in retinogenesis as well as for preclinical trials in NHPs studying retinal allograft transplantation.

scholarly journals Selective Ablation of Cochlear Hair Cells Promotes Engraftment of Human Embryonic Stem Cells-derived Progenitors in The Mouse organ of Corti

2020 ◽  
Author(s):  
Hiroki Takeda ◽  
Anna Dondzillo ◽  
Jessica A. Randall ◽  
Samuel P. Gubbels
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Inner Ear ◽  
Hair Cells ◽  
Pluripotent Stem Cells ◽  
Embryonic Stem ◽  
Organ Of Corti ◽  
Human Stem Cells ◽  
Cochlear Hair Cells ◽  
Mouse Organ

Abstract Backgroud: Hearing loss affects 25% of the population at ages 60–69 years. Loss of the hair cells of the inner ear commonly underlies deafness and once lost this cell type cannot spontaneously regenerate in higher vertebrates. As a result there is a need for the development of regenerative strategies to replace hair cells once lost. Stem cell-based therapies are one such strategy and offer promise for cell replacement in a variety of tissues. A number of investigators have previously demonstrated successful implantation, and certain level of regeneration of hair and supporting cells in both avian and mammalian models using rodent pluripotent stem cells. However, the ability of human stem cells to engraft and generate differentiated cell types in the inner ear is not well understood. Methods: We differentiate human pluripotent stem cells to the pre-placodal stage in vitro then transplant them into the mouse cochlea after selective and complete lesioning of the endogenous population of hair cells. Results: We demonstrate that hair cell ablation prior to transplantation leads to increased engraftment in the auditory sensory epithelium, the organ of Corti, as well as differentiation of transplanted cells into hair and supporting cell immunophenotypes. Conclusion: We have demonstrated the feasibility of human stem cell engraftment into an ablated mouse organ of Corti.

scholarly journals Stem cell potency and the ability to contribute to chimeric organisms

Reproduction ◽  
2013 ◽  
Vol 145 (3) ◽  
pp. R81-R88 ◽  
Author(s):  
Irina Polejaeva ◽  
Shoukhrat Mitalipov
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Pluripotent Stem Cells ◽  
Embryonic Stem ◽  
Cell Lineage ◽  
Cell Types ◽  
Preimplantation Embryos ◽  
Competent Cell ◽  
Current State ◽  
Host Embryo

Mouse embryonic chimeras are a well-established tool for studying cell lineage commitment and pluripotency. Experimental chimeras were successfully produced by combining two or more preimplantation embryos or by introducing into host embryo cultured pluripotent embryonic stem cells (ESCs). Chimera production using genetically modified ESCs became the method of choice for the generation of knockout or knockin mice. Although the derivation of ESCs or ESC-like cells has been reported for other species, only mouse and rat pluripotent stem cells have been shown to contribute to germline-competent chimeras, which is the defining feature of ESCs. Herein, we describe different approaches employed for the generation of embryonic chimeras, define chimera-competent cell types, and describe cases of spontaneous chimerism in humans. We also review the current state of derivation of pluripotent stem cells in several species and discuss outcomes of various chimera studies when such cells are used.

scholarly journals Selective ablation of cochlear hair cells promotes engraftment of human embryonic stem cell-derived progenitors in the mouse organ of Corti

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hiroki Takeda ◽  
Anna Dondzillo ◽  
Jessica A. Randall ◽  
Samuel P. Gubbels
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Inner Ear ◽  
Hair Cells ◽  
Pluripotent Stem Cells ◽  
Embryonic Stem ◽  
Organ Of Corti ◽  
Human Stem Cells ◽  
Cochlear Hair Cells ◽  
Mouse Organ

Abstract Background Hearing loss affects 25% of the population at ages 60–69 years. Loss of the hair cells of the inner ear commonly underlies deafness and once lost this cell type cannot spontaneously regenerate in higher vertebrates. As a result, there is a need for the development of regenerative strategies to replace hair cells once lost. Stem cell-based therapies are one such strategy and offer promise for cell replacement in a variety of tissues. A number of investigators have previously demonstrated successful implantation, and certain level of regeneration of hair and supporting cells in both avian and mammalian models using rodent pluripotent stem cells. However, the ability of human stem cells to engraft and generate differentiated cell types in the inner ear is not well understood. Methods We differentiate human pluripotent stem cells to the pre-placodal stage in vitro then transplant them into the mouse cochlea after selective and complete lesioning of the endogenous population of hair cells. Results We demonstrate that hair cell ablation prior to transplantation leads to increased engraftment in the auditory sensory epithelium, the organ of Corti, as well as differentiation of transplanted cells into hair and supporting cell immunophenotypes. Conclusion We have demonstrated the feasibility of human stem cell engraftment into an ablated mouse organ of Corti. Graphical abstract

scholarly journals Multiple Roles for Cholinergic Signaling from the Perspective of Stem Cell Function

2021 ◽  
Vol 22 (2) ◽  
pp. 666
Author(s):  
Toshio Takahashi
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Function ◽  
Cell Activity ◽  
Embryonic Stem ◽  
Cholinergic Neurons ◽  
Cell Types ◽  
Proliferative Potential ◽  
True Nature ◽  
Cholinergic Signaling

Stem cells have extensive proliferative potential and the ability to differentiate into one or more mature cell types. The mechanisms by which stem cells accomplish self-renewal provide fundamental insight into the origin and design of multicellular organisms. These pathways allow the repair of damage and extend organismal life beyond that of component cells, and they probably preceded the evolution of complex metazoans. Understanding the true nature of stem cells can only come from discovering how they are regulated. The concept that stem cells are controlled by particular microenvironments, also known as niches, has been widely accepted. Technical advances now allow characterization of the zones that maintain and control stem cell activity in several organs, including the brain, skin, and gut. Cholinergic neurons release acetylcholine (ACh) that mediates chemical transmission via ACh receptors such as nicotinic and muscarinic receptors. Although the cholinergic system is composed of organized nerve cells, the system is also involved in mammalian non-neuronal cells, including stem cells, embryonic stem cells, epithelial cells, and endothelial cells. Thus, cholinergic signaling plays a pivotal role in controlling their behaviors. Studies regarding this signal are beginning to unify our understanding of stem cell regulation at the cellular and molecular levels, and they are expected to advance efforts to control stem cells therapeutically. The present article reviews recent findings about cholinergic signaling that is essential to control stem cell function in a cholinergic niche.

scholarly journals Strategy to Establish Embryo-Derived Pluripotent Stem Cells in Cattle

2021 ◽  
Vol 22 (9) ◽  
pp. 5011
Author(s):  
Daehwan Kim ◽  
Sangho Roh
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Embryonic Stem Cells ◽  
Induced Pluripotent Stem Cells ◽  
Stem Cell Research ◽  
Pluripotent Stem Cells ◽  
Embryonic Stem ◽  
Culture Conditions ◽  
Human Diseases ◽  
Induced Pluripotent

Stem cell research is essential not only for the research and treatment of human diseases, but also for the genetic preservation and improvement of animals. Since embryonic stem cells (ESCs) were established in mice, substantial efforts have been made to establish true ESCs in many species. Although various culture conditions were used to establish ESCs in cattle, the capturing of true bovine ESCs (bESCs) has not been achieved. In this review, the difficulty of establishing bESCs with various culture conditions is described, and the characteristics of proprietary induced pluripotent stem cells and extended pluripotent stem cells are introduced. We conclude with a suggestion of a strategy for establishing true bESCs.

scholarly journals Telomere length set point regulation in human pluripotent stem cells critically depends on the shelterin protein TPP1

2020 ◽  
Vol 31 (23) ◽  
pp. 2583-2596
Author(s):  
John M. Boyle ◽  
Kelsey M. Hennick ◽  
Samuel G. Regalado ◽  
Jacob M. Vogan ◽  
Xiaozhu Zhang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Telomere Length ◽  
Pluripotent Stem Cells ◽  
Human Stem Cells ◽  
Set Point ◽  
Hypomorphic Allele ◽  
Point Control ◽  
Set Point Control ◽  
Stem Cell Lines

To better understand telomere length set point control in human stem cells, we generated knockout stem cell lines for TPP1 and contrasted their phenotypes with those of homozygous TPP1 L104A mutant stem cells. This comparison reveals that TPP1 L104A is not a hypomorphic allele but formally establishes TPP1 L104 as a dissociation of function mutant.

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