Role of Embryonic Stem Cells in Regeneration of Tissues and Organs

Corresponding Author:

Robert N Ben
Department of Tissue Engineering, Laval University, Quebec, Canada
E-mail: RNben@uottawa.cas

Received: 03-Nov-2023, Manuscript No. SRRM-23-122118; Editor assigned: 06-Nov-2023, Pre QC No. SRRM-23-122118 (PQ); Reviewed: 20-Nov-2023, QC No. SRRM-23-122118; Revised: 27-Nov-2023, Manuscript No. SRRM-23-122118 (R); Published: 04-Dec-2023, DOI: 10.37532/SRRM.2023.6(6).137-138

Introduction

Early-stage embryos, a kind of cells created in an in vitro fertilisation clinic when eggs are fertilised with sperm, are the source of embryonic stem cells. The ethical concerns surrounding the use of human embryonic stem cells in research have been brought up by the fact that these cells are taken from human embryos.

In 2009, the national institutes of health established guidelines pertaining to research on human stem cells. The guidelines contain instructions for the donation of embryonic stem cells as well as a definition of what embryonic stem cells are and how they can be used in research. Additionally, the recommendations specify that the use of embryonic stem cells derived from in vitro fertilisation embryos is limited to the time at which the embryo is no longer needed.

Description

The eggs from which the embryos used in embryonic stem cell research are derived were fertilised in in vitro fertilisation clinics; nevertheless, the eggs were never placed inside the uteruses of women. Donors provide their informed consent before donating stem cells. In test tubes or petri dishes in labs, the stem cells can survive and proliferate in particular solutions.

The cells that comprise a blastocyst’s inner cell mass before they are implanted in the uterus are known as embryonic stem cells, or ESCs. The blastocyst stage of human embryonic development, which has 50-150 cells, is achieved 4-5 days following fertilisation. Because they are pluripotent, Embryonic Stem Cells (ESCs) can differentiate into any of the three germ layers’ derivatives-endoderm, mesoderm, and ectoderm. Put another way, when given the right amount of stimulation, they can differentiate into any one of the more than 200 cell types that make up the adult body. They don’t support the placenta or the extra-embryonic membranes.

The inner cell mass’s cells continually proliferate and become more specialised during embryonic development. For instance, some of the ectoderm in the embryo’s dorsal region specialise in becoming “neurectoderm,” or the future central nervous system. The neurectoderm forms the neural tube later in development as a result of neurulation. At the neural tube stage, the anterior portion undergoes encephalization to generate or ‘pattern’ the basic form of the brain. Neural stem cells are thought to be the primary cell type in the central nervous system at this stage of development.

After undergoing self-renewal, the neural stem cells eventually develop into Radial Glial Progenitor Cells (RGPs). Early-formed RGPs divide symmetrically to generate a reservoir group of progenitor cells through self-renewal. These cells undergo a shift to a neurogenic state and begin dividing asymmetrically, giving rise to a wide variety of distinct neuron types, each with its own distinct morphology, function, and gene expression. Neurogenesis is the process by which radial glial cells develop into neurons. A characteristic feature of the radial glial cell’s bipolar architecture is its very elongated processes, which extend the length of the neural tube wall. Certain traits are similar to those of glia, most notably the production of GFAP (Glial Fibrillary Acidic Protein). The ventricular zone, which is next to the growing ventricular system, is home to the radial glial cell, which is the principal neural stem cell of the developing vertebrate central nervous system. The potency of neural stem cells is limited because they are dedicated to the neuronal lineages (oligodendrocytes, astrocytes, and neurons).

Human or mouse Embryonic Stem Cells (hES) generated from the early inner cell mass have been used in nearly every study to date. They both possess the key properties of stem cells, but to remain in an undifferentiated form, they need radically different settings. Mouse ES cells need Leukaemia Inhibitory Factor (LIF) in serum media to proliferate; they are cultured on a layer of gelatin extracellular matrix (for support).

It has also been demonstrated that 2i, a pharmacological cocktail comprising inhibitors of the MAPK/ERK pathway and GSK3B, preserves pluripotency in stem cell culture. Reference mouse embryonic fibroblasts serve as a feeder layer for the formation of human ESCs, which need basic fibroblast growth factor (bFGF or FGF-2). Unless there is genetic modification or ideal culture circumstances, embryonic stem cells will quickly differentiate.

Additionally, the expression of many transcription factors and cell surface proteins characterises human embryonic stem cells. The basic regulatory network that guarantees the suppression of genes that contribute to differentiation and the maintenance of pluripotency is composed of the transcription factors Oct-4, Nanog, and Sox2.

The glycolipids, stage-specific embryonic antigens 3 and 4, and the keratan sulphate antigens Tra-1-60 and Tra-1-81 are the most often employed cell surface antigens to identify hES cells. Numerous additional proteins are included in the molecular definition of a stem cell, which is still being studied.

The potential for regenerative medicine and tissue restoration following damage or disease remains with embryonic stem cells due to their pluripotency and limitless growth capacity. However, as of right now, ES cell-based therapies are not authorised. In January 2009, the US food and drug administration approved the first human experiment.

Conclusion

Developing embryonic stem cells into viable cells and preventing transplant rejection are just a few of the challenges that researchers are still facing. Since embryonic stem cells are pluripotent, they need particular signals to differentiate properly. If ES cells are injected into another person’s body, they will proliferate into a wide variety of cell types, which will result in a teratoma. The absence of authorised treatments utilising embryonic stem cells can also be attributed to ethical concerns over the use of human embryonic tissue. The creation of novel human ES cell lines or moratoria on human ES cell research are now in place in several countries.