STEM CELL LINES - A WalkThrough

Author: Preity Yadav

The Stem Cell (SC) line is a set of stem cells that can be grown in the laboratory. They can be cultivated in vitro. An SC line starts with a sole cell or with a set of cells, and all occurring cells in the line are copies of the original cells. The SC lines are produced and kept in incubators at precise temperature and atmospheric conditions (37 degrees Celsius & 5% CO2). The culture conditions, like the cell growth medium and the surface on which the cells are grown, vary on a large scale depending on that precise stem cell line.

Image Credits: Carly Ziegler, Alex Shalek, Shaina Carroll (MIT) and Leslie Kean, Victor Tkachev and Lucrezia Colonna (Dana-Farber Cancer Institute) / Wellcome Photography Prize 2019 CC4.0 link wikimedia

The addition of Biochemical factors can be done to the medium in order to control cell phenotype, for example, to keep stem cells in a pluripotent state or to differentiate them into a certain cell type. They can be derived from human tissues such as embryonic SC, adult stem cells & induced stem cells or derived from animals. Scientists operating on these stem cell lines can produce a large number of cells. They can be conserved by keeping them in liquid nitrogen. An embryonic SC line is produced from cells acquired from the inner cell mass of the blastocyst, an early-stage embryo, before implantation. In humans, the blastocyst period happens 4-5 days after implantation. The cell mass is removed from the blastocyst, separated from the trophectoderm and grown in vitro on a supporting cell layer.

In obtaining human embryonic SC lines, embryos are used that are the remainder of in vitro fertilization (IVF) procedures. the blastocyst being damaged throughout the process leads to controversy and ethical concerns. In vitro, embryonic stem cells can be cultivated under defined conditions in order to keep them in their pluripotent state, or they can be stimulated with biochemical and physical cues to differentiate them into different cell types. Among the adult stem cell types, only mesenchymal SC can be successfully grown in culture for long periods of time. Other adult stem cell types, for instance, hematopoietic stem cells, are difficult to grow and propagate in vitro. Therefore, although mesenchymal stem cell lines subsist, other different types of adult stem cells cultured in vitro can be better be classified as primary cells.

The iPSC generation method was developed by Shinya Yamanaka's laboratory in 2006. This group showed that the introduction of four specific genes can induce somatic cells to revert to a pluripotent stem cell state. In contrast to embryonic stem cell lines, iPSC lines are also pluripotent in nature but can be obtained without the use of human embryos, which raises ethical concerns. In addition, patient-specific iPSC cell lines can be generated, i.e., cell lines that are genetically paired with an individual. Patient-specific iPSC lines were developed to study diseases and developed patient-specific medical therapies.

The application of Stem cell lines plays a major role in regenerative medicine and research. They can be utilised to work on stem-cell biology & on early human development. In the domain of regenerative medicine, it has been put forward that SC can be utilised in cell-based therapies to restore injured or diseased cells & tissues. For instance, conditions that may be cured using stem cell lines include diabetes, neurodegenerative diseases & spinal cord injuries.

In the United States, Executive Order 13505 stated that federal funds could be used for research using approved human embryonic stem cell lines (hESC), but not for the derivation of new lines. Human Stem Cell Research implemented Executive Order 13505 effective from July 7, 2009, defining the criteria that hESC lines must meet in order to be eligible for funding. The NIH Human Embryonic Stem Cell Registry is available online and contains the latest details on cell lines eligible for NIH funding. As of March 2017, 378 lines have been approved.

Although there are many differences between embryonic and non-embryonic stem cells, most researchers find them both to be correspondingly useful in anything from producing a basic stem line to genetic therapy. Some studies reveal that non-embryonic stem cells may not multiply as easily as embryonic ones and that scientists have not yet found adult cells that can develop all types of tissues. Also, embryonic cells usually do not contain the number of abnormalities as caused by toxins, sunlight & other factors that are prone to influence non-embryonic cells. Research on human embryonic stem cell lines (hESC) has drawn increasing awareness over the past decade, as these cells have the ability to multiply indefinitely and differentiate into any cell type in the body. On the other hand, there have been a lot of disagreements regarding the application of hESCs due to their origin in early human embryos, which resulted in a wide panel of different national legislations on human ESC research.

ABSTRACT:

The SC line is a set of SC that can be grown in the laboratory. They can be cultivated in vitro. An SC line starts with a sole cell or with a set of cells, and all occurring cells in the line are copies of the original cells. The application of Stem cell lines plays a major role in regenerative medicine and research. They can be utilised to work on stem-cell biology & on early human development. In the domain of regenerative medicine, it has been put forward that SC can be utilised in cell-based therapies to restore injured or diseased cells & tissues. Research on human embryonic stem cell lines (hESC) has drawn increasing awareness over the past decade, as these cells have the ability to multiply indefinitely and differentiate into any cell type in the body. On the other hand, there have been a lot of disagreements regarding the application of hESCs due to their origin in early human embryos, which resulted in a wide panel of different national legislations on human ESC research.

REFERENCES:

📌 What Is A Stem Cell Line? January 2, 2018. INGENIOUS TARGETING LABORATORY. (weblink)

📌 Human Embryonic Stem Cell Lines and Their Use in International Research, Peter Löser, Jacqueline Schirm, Anke Guhr, Anna M Wobus, and Andreas Kurtz. (weblink)

About the Author:

Preity Yadav, a graduate student of the University School of Chemical Technology, GGSIP University, Delhi. She is pursuing her degree in Biochemical engineering.