1. What are stem cells?

2021 ◽  
pp. 1-18
Author(s):  
Jonathan Slack
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Structural Unit ◽  
Embryonic Stem ◽  
Cell Types ◽  
The Body ◽  
Differentiated Cells ◽  
Mammalian Embryos ◽  
A Cell

‘What are stem cells?’ explains that a stem cell is a cell that can both reproduce itself and generate offspring of different functional cell types and begins by considering the nature of cells in general, wherein cells are understood to be the ultimate structural unit of an animal or plant body. Stem cells in the body persist long term, usually for the lifetime of the organism. Good examples of differentiated cells arising from stem cells are those of the skin, the blood, and the lining of the intestine. Embryonic stem cells are grown in culture from early mammalian embryos. The reason that stem cell research is seen as the source for new cures is largely because this technology offers a route to cell therapy.

Stem Cells: In Sickness and in Health

2020 ◽  
Vol 15 ◽  
Author(s):  
Hisham F. Bahmada ◽  
Mohamad K. Elajami ◽  
Reem Daouk ◽  
Hiba Jalloul ◽  
Batoul Darwish ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Induced Pluripotent Stem Cell ◽  
Cell Types ◽  
Therapy Resistance ◽  
The Body ◽  
Differentiated Cells ◽  
Undifferentiated Cells ◽  
Potential Applications ◽  
Induced Pluripotent

: Stem cells are undifferentiated cells with the ability to proliferate and convert to different types of differentiated cells that make up the various tissues and organs in the body. They exist both in embryos as pluripotent stem cells that can differentiate into the three germ layers and as multipotent or unipotent stem cells in adult tissues to aid in repair and homeostasis. Perturbations in these cells’ normal functions can give rise to a wide variety of diseases. In this review, we discuss the origin of different stem cell types, their properties and characteristics, their role in tissue homeostasis, current research, and their potential applications in various life-threatening diseases. We focus on neural stem cells, their role in neurogenesis and how they can be exploited to treat diseases of the brain including neurodegenerative diseases and cancer. Next, we explore current research in induced pluripotent stem cell (iPSC) techniques and their clinical applications in regenerative and personalized medicine. Lastly, we tackle a special type of stem cells called cancer stem cells (CSCs) and how they can be responsible for therapy resistance and tumor recurrence and explore ways to target them.

scholarly journals Potential Clinical Applications for Human Pluripotent Stem Cell-Derived Blood Components

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Erin A. Kimbrel ◽  
Shi-Jiang Lu
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Large Scale ◽  
Embryonic Stem ◽  
Adult Stem Cell ◽  
Cell Types ◽  
The Body ◽  
Blood Components ◽  
Induced Pluripotent

The ability of human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) to divide indefinitely without losing pluripotency and to theoretically differentiate into any cell type in the body makes them highly attractive cell sources for large scale regenerative medicine purposes. The current use of adult stem cell-derived products in hematologic intervention sets an important precedent and provides a guide for developing hESC/iPSC based therapies for the blood system. In this review, we highlight biological functions of mature cells of the blood, clinical conditions requiring the transfusion or stimulation of these cells, and the potential for hESC/iPSC-derivatives to serve as functional replacements. Many researchers have already been able to differentiate hESCs and/or iPSCs into specific mature blood cell types. For example, hESC-derived red blood cells and platelets are functional in tasks such as oxygen delivery and blood clotting, respectively and may be able to serve as substitutes for their donor-derived counterparts in emergencies. hESC-derived dendritic cells are functional in antigen-presentation and may be used as off-the-shelf vaccine therapies to stimulate antigen-specific immune responses against cancer cells. However,in vitrodifferentiation systems used to generate these cells will need further optimization before hESC/iPSC-derived blood components can be used clinically.

scholarly journals Is Stem Cell a Curer or an Obstruction?

2017 ◽  
Vol 1 (1) ◽  
pp. 17
Author(s):  
Siska Damayanti ◽  
Rina Triana ◽  
Angliana Chouw ◽  
Nurrani Mustika Dewi
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Therapy ◽  
Stem Cell Therapy ◽  
Embryonic Stem ◽  
Cell Types ◽  
Tumor Formation ◽  
The Body ◽  
Negative Effects ◽  
Tissue Repair And Regeneration

Introduction: Each cell in human body is assigned with a specialized function to perform.  Before a cell becomes specialized, it is a stem cell. Stem cell research and therapy is progressing dramatically these days. Stem cell therapy holds enormous treatment potential for many diseases which currently have no or limited therapeutic options. Unfortunately, this potential also comes with side-effects. In this review, the positive and negative effects of regulation of stem cells will be explained.Content: Stem cells are undifferentiated cells that have potential to develop into many different cell types in the body during early life and growth. The type of stem cells are embryonic stem cells, induced pluripotent stem cells, somatic stem cells, foetal stem cells and mesenchymal stem cells. Stem cell transplantation is one form of stem cell therapy, it comes with different sources, and those are autologous and allogenic transplantation stem cells. In an autologous transplant, a patient’s own blood-forming stem cells are collected, meanwhile in an allogeneic transplant, a person’s stem cells are replaced with new stem cells obtained from a donor or from donated umbilical cord blood.Summary: Its abilities to maintain undifferentiated phenotype, self-renewing and differentiate itself into specialized cells, give rise to stem cell as a new innovation for the treatment of various diseases. In the clinical setting, stem cells are being explored in various conditions, such as in tissue repair and regeneration and autoimmune diseases therapy. But along with its benefit, stem cell therapy also holds some harm. It is known that the treatment using stem cell for curing and rehabilitation has the risk in tumor formation.

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 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

Types of Stem Cells Used in US-Based Clinical Trials between 1999 and 2014

2021 ◽  
Vol 26 ◽  
pp. 169-191
Author(s):  
Emma E. Redfield ◽  
Erin K. Luciano ◽  
Monica J. Sewell ◽  
Lucas A. Mitzel ◽  
Isaac J. Sanford ◽  
...  
Keyword(s):  
Stem Cells ◽  
Clinical Trials ◽  
Stem Cell ◽  
Embryonic Stem Cells ◽  
Adult Stem Cells ◽  
Embryonic Stem ◽  
Cell Types ◽  
The Us ◽  
Health Database ◽  
Induced Pluripotent

This study looks at the number of clinical trials involving specific stem cell types. To our knowledge, this has never been done before. Stem cell clinical trials that were conducted at locations in the US and registered on the National Institutes of Health database at ‘clinicaltrials.gov’ were categorized according to the type of stem cell used (adult, cancer, embryonic, perinatal, or induced pluripotent) and the year that the trial was registered. From 1999 to 2014, there were 2,357 US stem cell clinical trials registered on ‘clinicaltrials.gov,’ and 89 percent were from adult stem cells and only 0.12 percent were from embryonic stem cells. This study concludes that embryonic stem cells should no longer be used for clinical study because of their irrelevance, moral questions, and induced pluripotent stem cells.

Accept or Reject: The Role of Immune Tolerance in the Development of Stem Cell Therapies and Possible Future Approaches

2020 ◽  
pp. 019262332091824
Author(s):  
Richard Haworth ◽  
Michaela Sharpe
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Embryonic Stem ◽  
Immune Recognition ◽  
Cell Of Origin ◽  
In Vivo Models ◽  
Cell Product ◽  
A Cell

In 2011, Goldring and colleagues published a review article describing the potential safety issues of novel stem cell-derived treatments. Immunogenicity and immunotoxicity of the administered cell product were considered risks in the light of clinical experience of transplantation. The relative immunogenicity of mesenchymal stem cells, embryonic stem cells (ESCs), and induced pluripotent stem cells (iPSCs) was being addressed through in vitro and in vivo models. But the question arose as to whether the implanted cells needed to be identical to the recipient in every respect, including epigenetically, to evade immune recognition? If so, this set a high bar which may preclude use of many cells derived from iPSCs which have vestiges of a fetal phenotype and epigenetic memory of their cell of origin. However, for autologous iPSCs, the immunogenicity reduces once the surface antigen expression profile becomes close to that of the parent somatic cells. Therefore, a cell product containing incompletely differentiated cells could be more immunogenic. The properties of the administered cells, the immune privilege of the administration site, and the host immune status influence graft success or failure. In addition, the various approaches available to characterize potential immunogenicity of a cell therapy will be discussed.

Stem Cells and Tissue Engineering Techniques

2013 ◽  
Vol 80 (1) ◽  
pp. 11-19
Author(s):  
Gigliola Sica
Keyword(s):  
Tissue Engineering ◽  
Stem Cells ◽  
Clinical Trials ◽  
Stem Cell ◽  
Urinary Tract ◽  
Animal Models ◽  
Embryonic Stem ◽  
Cell Types ◽  
Ethical Concerns ◽  
Neoplastic Lesions

The therapeutic use of stem cells and tissue engineering techniques are emerging in urology. Here, stem cell types, their differentiating potential and fundamental characteristics are illustrated. The cancer stem cell hypothesis is reported with reference to the role played by stem cells in the origin, development and progression of neoplastic lesions. In addition, recent reports of results obtained with stem cells alone or seeded in scaffolds to overcome problems of damaged urinary tract tissue are summarized. Among others, the application of these biotechnologies in urinary bladder, and urethra are delineated. Nevertheless, apart from the ethical concerns raised from the use of embryonic stem cells, a lot of questions need to be solved concerning the biology of stem cells before their widespread use in clinical trials. Further investigation is also required in tissue engineering utilizing animal models.

scholarly journals Mammalian genes induce partially reprogrammed pluripotent stem cells in non-mammalian vertebrate and invertebrate species

eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Ricardo Antonio Rosselló ◽  
Chun-Chun Chen ◽  
Rui Dai ◽  
Jason T Howard ◽  
Ute Hochgeschwender ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Pluripotent Stem Cells ◽  
Mammalian Species ◽  
Embryonic Stem ◽  
Model Organisms ◽  
Differentiated Cells ◽  
Transcription Factor Genes ◽  
Induced Pluripotent

Cells are fundamental units of life, but little is known about evolution of cell states. Induced pluripotent stem cells (iPSCs) are once differentiated cells that have been re-programmed to an embryonic stem cell-like state, providing a powerful platform for biology and medicine. However, they have been limited to a few mammalian species. Here we found that a set of four mammalian transcription factor genes used to generate iPSCs in mouse and humans can induce a partially reprogrammed pluripotent stem cell (PRPSCs) state in vertebrate and invertebrate model organisms, in mammals, birds, fish, and fly, which span 550 million years from a common ancestor. These findings are one of the first to show cross-lineage stem cell-like induction, and to generate pluripotent-like cells for several of these species with in vivo chimeras. We suggest that the stem-cell state may be highly conserved across a wide phylogenetic range.

Maintenance of Pluripotent Stem Cells is Influenced by Ser/Thr Metabolism

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. SCI-43-SCI-43
Author(s):  
Lewis C. Cantley
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Embryonic Stem ◽  
Isocitrate Dehydrogenase 1 ◽  
Advisory Committees ◽  
Metabolic Intermediates ◽  
Stem Cell Maintenance ◽  
Differentiated Cells ◽  
Methylation Of Dna

Abstract Recent studies have suggested not only that stem cells have different metabolic requirements than terminally differentiated cells, but also that metabolic intermediates may play a role in the maintenance of stem cells. It has long been clear that changes in acetylation and methylation of histones, as well as methylation of DNA play critical roles in deciding cell fate. The availability of critical intermediates in metabolism, especially S-adenosylmethionine (SAM), acetyl-CoA, nicotinamide adenine dinucleotide (NAD) and a-ketoglutarate play critical roles in modulating acetylation and methylation of histones and methylation of DNA. In the course of evaluating an unusual requirement of threonine (Thr) for the growth of murine embryonic stem cells, we found that metabolism of Thr to glycine (Gly) and the subsequent use of the methyl group of Gly for converting homocysteine to methionine is critical for maintaining high levels of SAM and low levels of S-adenosyl-homocysteine. Importantly, depletion of Thr from the media resulted in decreased tri-methylation of histone H3 lysine-4 (H3K4me3), leading to slowed growth and increased differentiation. Thus, abundance of SAM appears to influence H3K4me3, providing a possible mechanism by which modulation of a metabolic pathway might influence stem cell fate. Demethylation of histones and DNA can also be controlled by metabolic intermediates. Mutated forms of isocitrate dehydrogenase 1 (IDH1) and IDH2 that drive acute myeloid leukemia (AML) and other cancers, produce an oncometabolite (2-hydrogyglutarate) that can compete with the a-ketoglutarate requirement for enzymes involved in hydroxy-methylation and subsequent demethylation of DNA and histones. Recent studies indicate that 2-hydroxyglutarate plays a role in blocking differentiation of cancer cells. These and other observations linking intermediates in metabolism to stem cell maintenance will be discussed. Disclosures Cantley: Agios Pharmaceuticals: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties.

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