Characteristics of Partially Differentiated Cells: Stem Cells

Corresponding Author:

Syed Shadab Raza
Department of Cell Biology, Madras University, Chennai, Tamil Nadu, India
E-mail: drshadabRaza@erauniversity.in

Received: 03-Nov-2023, Manuscript No. SRRM-23-122117; Editor assigned: 06-Nov-2023, Pre QC No. SRRM-23-122117 (PQ); Reviewed: 20-Nov-2023, QC No. SRRM-23-122117; Revised: 27-Nov-2023, Manuscript No. SRRM-23-122117 (R); Published: 04-Dec-2023, DOI: 10.37532/SRRM.2023.6(6).135-136

Introduction

Stem cells are undifferentiated or partially differentiated cells that can multiply endlessly to create more of the same stem cell in multicellular creatures. They can also specialise into other types of cells. Within a cell lineage, they are the most ancient sort of cell. Although they are present in both adult and embryonic creatures, their characteristics differ slightly in each. They are typically distinguished from precursor or blast cells, which are typically dedicated to developing into a single cell type, and progenitor cells, which are unable to divide endlessly.

In mammals, the inner cell mass during the blastocyst stage of embryonic development, or days 5-14, is composed of approximately 50-150 cells. These possess stem-cell properties. They eventually differentiate into every type of cell in the body while still in vivo, which makes them pluripotent. At the gastrulation stage, this process begins with the differentiation into the three germ layers: The ectoderm, mesoderm, and endoderm. Nevertheless, they can be maintained in the stem-cell stage and are referred to as Embryonic Stem Cells (ESCs) when they are extracted and cultivated in vitro.

Description

There are a few specific places in the body called niches where adult stem cells can be found, like the gonads and bone marrow. They are multipotent or unipotent, which means they can only differentiate into a small number of cell types or into a single type of cell, and they exist to quickly replace lost cell types. These include mesenchymal stem cells, which maintain bone, cartilage, muscle, and fat cells, basal cells, which maintain the skin epithelium, and hematopoietic stem cells, which renew blood and immune cells in animals. The progenitor cells and terminally differentiated cells into which adult stem cells differentiate make up a great majority of cells, of which adult stem cells are a tiny fraction.

As of 2016, hematopoietic stem cell transplantation is the sole recognised medical treatment utilising stem cells. This procedure was pioneered in 1958 by French oncologist Georges Mathe. However, human embryonic stem cells have been able to be cultured and differentiated (in stem-cell lines) since 1998. Because separating these cells usually ends in the destruction of the embryo, the method has generated controversy. Some European nations, including Canada, have restricted access to sources for isolating ESCs; while, other nations, including the UK and China, have encouraged this study. The cloning technique known as somatic cell nuclear transfer can be utilised to produce a cloned embryo whose embryonic stem cells can be used for stem cell treatment.

Ernest McCulloch and James Till at the university of Toronto and the Ontario cancer institute initially identified the essential characteristics of a stem cell in the early 1960’s. Through their ground breaking study in mice, they were able to identify the Hematopoietic Stem Cell (HSC), which is a stem cell that forms blood. In a series of tests, mice that had received radiation were given injections of bone marrow cells by McCulloch and Till. The number of bone marrow cells injected was linearly correlated with the tumours they saw in the mice’s spleens. They postulated that every lump, or colony, was a clone that developed from a single stem cell in the marrow.

In 1958, French oncologist Georges Mathe performed a bone marrow transplant on five Vinca nuclear institute employees in Yugoslavia who had suffered from a criticality accident. This was the first stem cell therapy.

British biologists Martin Evans and Matthew Kaufman successfully extracted and grew Embryonic Stem (ES) cells using mouse blastocysts in 1981. This made it possible to create mouse genetic models, a method where mice’s genes are removed or changed to examine their role in pathology. American biologist James Thomson was the first to identify human embryonic stem cells in 1998, which allowed for the development of novel transplanting techniques and a range of cell types for the testing of novel therapies.

By altering the expression of just four genes, Shinya Yamanaka’s group in Kyoto, Japan was able to transform fibroblasts into pluripotent stem cells in 2006. This accomplishment symbolises the source of induced pluripotent stem cells, or iPS cells. The first known instance of using stem cells to treat wounds in a wild animal occurred in 2011, when a truck ran over a female maned wolf at the zoo Brasília.

Properties

The classical definition of a stem cell requires that it possesses two properties:

Self-renewal: The capacity to continue as an undifferentiated cell through multiple rounds of division and expansion. This process is also referred to as cell proliferation.

Potency: The ability to develop into particular cell types. Although multipotent or unipotent progenitor cells are commonly referred to be stem cells, in the strictest sense, this means that stem cells must be either totipotent or pluripotentto be able to give rise to any adult cell type. In addition, it is claimed that a feedback system controls stem cell activity.

Conclusion

In real life, stem cells are distinguished based on their capacity to regenerate tissue. For instance, the capacity to transplant bone marrow or Hematopoietic Stem Cells (HSCs) and preserve the life of a person devoid of HSCs is the distinguishing test for these cells. This indicates that the cells have the capacity to continuously create new blood cells. Additionally, it ought to be feasible to separate the stem cells from the transplanted person, and those stem cells can then be transplanted into a different person who does not have HSCs, proving that the stem cell has the capacity for self-renewal.