When is a Stem Cell Really a Stem Cell?
Richard K. Burt, Alberto M. Marmont in Stem Cell Therapy for Autoimmune Disease, 2019
Undifferentiated cells that are found in a differentiated adult tissue are considered adult stem cells, particularly when these cells contribute to ongoing tissue maintenance or repair. These cells may be capable of self-renewal, but do not replicate indefinitely in culture. Adult stem cells may differentiate to produce progenitor, precursor, and mature cells, but these activities are usually limited to the cells contained in the tissue of origin. Adult stem cells usually comprise a small minority of the total tissue mass, and as such are usually quite difficult to identify and isolate. Adult stem cells have been described in regenerating tissues such as the liver, epithelium and muscle, as well as in tissues like the brain, which previously was thought not to possess extensive regenerative properties. By far, the most well-characterized example of adult stem cells is that of the hematopoietic system.
Stem Cells and Nanotechnology
Stavros Hatzopoulos, Andrea Ciorba, Mark Krumm in Advances in Audiology and Hearing Science, 2020
There are two basic types of SCs. The first type, the embryonic stem cells, are totipotent in humans from the zygote to the fourth division of the blastomeres: Within these developmental stages, they may originate any kind of tissue. After the fourth division, the blastomeres become pluripotent and may originate the three primary germ layers (ectoderm, mesoderm, and endoderm). The potency of embryonic stem cell progressively reduces along with differentiation (Surani et al., 2007; Hayashi and Surani, 2009). The second type, the adult stem cells (also called somatic stem cells) are unspecialized cells residing in niches among differentiated cells and are mostly multipotent. Adult stem cells have been identified in the bone marrow, skin, central nervous system, gut, muscle and adipose tissue (Ferraro et al., 2010). A new type of SC has been recently developed: they are the induced pluripotent stem cells (iPSC), differentiated cells that have been reprogrammed as pluripotent stem cells by insertion of genes coding for transcription factors (Takahashi and Yamanaka, 2006).
Tumor Growth
John Melford in Pocket Guide to Cancer, 2017
A stem cell may be defined as any cell with the ability to go through numerous cycles of cell division while maintaining an undifferentiated state. An adult stem cell can renew itself, and can differentiate to yield some, or all, of the major specialized cell types of its specific tissue or organ. Adult stem cells are present in many organs and tissues such as bone marrow, blood vessels, brain, heart, gut, liver, ovarian epithelium, skeletal muscle, skin, testis, and teeth. They are thought to be located at specific sites of each tissue type, called stem cell niches. Stem cells of the small intestine are in crypts in its lining, protected by layers of mucus. Those of white blood cells are stored in bone marrow. It appears that some pericytes, which are contractile cells that compose the outermost layer of small blood vessels, are stem cells.
Down-regulation of pluripotency and expression of SSEA-3 surface marker for mesenchymal Muse cells by in vitro expansion passaging
Published in Egyptian Journal of Basic and Applied Sciences, 2019
Ali M. Fouad, Mahmoud M. Gabr, Elsayed K. Abdelhady, Sahar A. Rashed, Sherry M. Khater, Mahmoud M. Zakaria
Stem cells can be divided as embryonic and non-embryonic stem cells. Embryonic stem cells are the gold standard for pluripotent stem cells which can differentiate into the three germ layers (ectoderm, endoderm and mesoderm). In the developing embryo, pluripotent stem cells are the origin of somatic and germline cells [1]. Adult stem cells as embryonic stem cells are all undifferentiated cells. However, the differentiation capacity of adult stem cells is limited to its origin. Hematopoietic and mesenchymal stem cells are the main identified types of adult stem cells, hematopoietic stem cells can be obtained from bone marrow, umbilical cord blood, and peripheral blood and are capable of generating all cell lineage found in mature blood [2]. While mesenchymal stem cells, in the suitable environment have the ability to differentiate into chondrocytes, adipocytes and osteocytes [3], and can be obtained from bone marrow as a primary source, fat tissue and umbilical cord [4]. In 2006, a scientific breakthrough was performed by Yamanaka and colleagues after generating pluripotent stem cells from somatic cells by genetic manipulation with pluripotent markers, these cells are called induced pluripotent stem cells (iPSCs) [5].
The Effect of Adipose-Derived Stromal Vascular Fraction Cells to Abdominal Wall Fascia Defects in Rats: An Experimental Study
Published in Journal of Investigative Surgery, 2022
Elif Tuncay, Ozan Akinci, Asiye Perek, Esin Aktas Cetin, Nuray Kepil, Murat Toksoy, Nurdan Altan
Stem cells are capable of self-renewal and can differentiate into many types of cells and turn into mature differentiated cells. Adipose tissue offers a rich and accessible reserve of multipotent adult stem cells for tissue engineering and regenerative medicine. Stromal vascular fraction (SVF), obtained through the enzymatic digestion of lipectomy material with collagenase, consists of mesenchymal stem cells. Adipose-derived mesenchymal stromal cells (AD-MSCs), originating from mesoblast cells, are multipotent and can differentiate into many types of cells, such as adipocytes, chondrocytes, osteoblasts, and myocytes [5]. A multipotent stem cell can be derived from various sources, such as bone marrow or umbilical cord blood. However, due to the difficulty in derivation and ethical concerns about multiple stem cells, accessing AD-MSCs is an easier, more convenient, and more cost-effective method [6–8].
Muscle-derived stem cells: important players in peripheral nerve repair
Published in Expert Opinion on Therapeutic Targets, 2018
Leila Musavi, Gerald Brandacher, Ahmet Hoke, Halley Darrach, W.P. Andrew Lee, Anand Kumar, Joseph Lopez
Stem cells, the precursor cells responsible for tissue maintenance and regeneration, have been widely investigated for their therapeutic potential in a number of diseases[1]. Embryonic stem cells, favored for their pluripotent nature and marked self-renewal capacity, have many potential restrictions to widespread application and clinical use due to federal regulatory restrictions, ethical considerations, possible tumor formation, and immune incompatibility. Adult stem cells (ASCs), conversely, are more readily available and are fully immune compatible when derived from autologous tissue; furthermore, they raise fewer concerns regarding ethical challenges related to conception and the beginning of independent life in the embryo/fetus [2]. ASCs can be isolated from a variety of tissues and induced to differentiate into myriad lineages [3–5].
Related Knowledge Centers
- Cell Division
- Embryonic Stem Cell
- Somatic Cell
- Tissue
- Cellular Differentiation
- Stem Cell
- Homeostasis
- Cell
- Cell Type
- Stem Cell Controversy