Stem Cells, Meaning, Types, Characteristics, Pluripotent Stem Cells, UPSC Notes

Stem cells are undifferentiated cells capable of self-renewal and transforming into specialized cells such as brain, muscle, or blood cells. They are broadly classified into embryonic stem cells (pluripotent) and adult stem cells (tissue-specific), with newer advances like induced pluripotent stem cells (iPSCs). Stem cell therapy is used for treating diseases like leukemia, paralysis, Alzheimer’s, and corneal damage by regenerating damaged tissues. While embryonic stem cell use raises ethical concerns, adult and iPSC-based therapies face fewer issues.

In this article on Stem Cells, we shall discuss its background, meaning, types, stem cell trials, associated concerns, and way forward. This article will be very useful for UPSC aspirants for UPSC Prelims Exam as well as the mains exam as questions can be asked about this topic in the Science and Technology portion of UPSC GS 3 Paper of Mains.

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What are Stem Cells?

The fundamental components of the body are stem cells, which give rise to all other cells with specialized functions.

• Daughter cells are created when stem cells divide properly to generate more cells in the body or a lab under appropriate conditions.
  • These daughter cells can either develop into additional stem cells or specialize into differentiated cells with a more defined purpose, such as bone, blood, brain, or heart muscle cells.
• No other cell in the body has the natural ability to generate new cell types.
• They have the ability to self-renew.
• They are unspecialized but they can give rise to specialized cell types.
• Cells in the body have specific purposes, but stem cells are cells that do not yet have a specific role and can become almost any cell that is required.

Stem cells are present inside different types of tissue. Scientists have found stem cells in tissues, including

• Brain
• Bone marrow
• Blood and blood vessels
• Skeletal muscles
• Skin
• Liver

Characteristics of Stem Cells

• Self-renewal – Stem cells can make exact copies of themselves through many cycles of cell division.
• Potency – They can change (differentiate) into other types of cells:
  • Totipotent → Can form all cell types, including embryonic tissues.
  • Pluripotent → Can make almost any cell type in the body.
  • Multipotent → Can make a limited range of related cell types.
  • Unipotent → Can form only one specific cell type.
• Undifferentiated nature – They do not have a fixed function until they get signals to become specific cells.
• Found in embryos and adults –
  • Embryonic stem cells → Highly potent.
  • Adult stem cells → Found in tissues like bone marrow, have limited potential.
• Repair and regeneration – They replace damaged or lost cells, helping heal tissues and maintain normal body functions.

Read the article on Structure, Types, Functions and Cell Theory!

Here, we will discuss the various types of stem cells which are present in human beings. Stem cells can originate from many different locations inside the body or can form at various points throughout our lifetimes and they can also be differentiated on the basis of their ability to develop into different specialized cells.

Classification of stem cells based on their formation at different phases of human lives

Here, we will discuss the formation of stem cells at different times in human lives.

What are Embryonic stem cells?

• Embryonic stem cells (ESCs), which are a component of the inner cell mass, are found in human blastocysts, at an early stage of the developing embryo.
• These are pluripotent(ploo-RIP-uh-tunt) stem cells, which can differentiate into any form of body cell or additional stem cells. Because of their adaptability, embryonic stem cells can be employed to replace or treat damaged tissue and organs.
• They persist from three to five days after fertilization.
• After the fifth day, they are gone, and the three layers of embryonic tissue begin to develop normally.
• Blastocyst-stage ESCs can be separated from the inner cell mass and grown in a lab environment, but given the right conditions, they will never stop dividing.
• ESCs still have the capacity to differentiate into cells from each of the three layers of embryonic tissue when they are in this undifferentiated state.
• Embryos are destroyed while their ESCs are being extracted.

What are Adult stem cells?

• ASCs are undifferentiated cells that can regenerate or produce new cells that can replace injured or dead tissue and those lost as a result of normal repair, illness, or damage. They are found in some differentiated tissues of our body. Adult stem cells are sometimes referred to as “somatic stem cells” as well.
• Somatic stem cells, or adult stem cells, are another name for them as the body’s non-reproductive cells are referred to as “soma” cells (eggs or sperm).
• ASCs are frequently insufficient in native tissues, making it difficult to investigate and separate them for analysis.
• In the majority of human physiological tissues, various populations of ASCs make new cells to replace those that are lost as a result of innate repair, illness, or damage.
• The umbilical cord, placenta, bone marrow, muscle, brain, adipose tissue, skin, and stomach are just a few of the body components that contain ASCs.

What are Induced pluripotent stem cells or iPSCs?

• A form of pluripotent stem cell produced from adult somatic cells is known as induced pluripotent stem (iPS) cells. Through the induction of genes and other stimuli, they have been reprogrammed to be pluripotent. In many ways, iPS cells and embryonic stem (ES) cells are similar.
• The development of iPSCs, which are generated from skin or blood cells and reprogrammed to return to a pluripotent stage akin to that of an embryo, has made it possible to create an unlimited source of any type of human cell needed for therapeutic purposes.
• For instance, iPSC can be stimulated to develop into neurons in order to cure neurological conditions, blood cells in order to produce fresh blood free of cancer cells for a patient with leukaemia, or beta islet cells in order to treat diabetes.

Read the article on Cell Organelles!

Classification of Stem cells based on their ability to develop into different specialized cells

Here, we will discuss the ability of stem cells to develop into different specialized cells.

What are Totipotent stem cells?

Totipotent stem cells have the ability to self-renew through division, giving rise to the three primary germ cell layers of the early embryo as well as extra-embryonic organs like the placenta.

What are Pluripotent stem cells?

All of the cells that make up the body’s tissues can be produced by pluripotent stem cells, which have the capacity to self-renew. Pluripotent stem cells (PSCs) can form cells of all germ layers, but they cannot create extraembryonic structures like the placenta.

What are Multipotent stem cells?

PSCs have a wider range of differentiation than multipotent stem cells, yet multipotent stem cells can specialize in discrete cells from particular cell lineages. Multiple benefits and applications are offered by multipotent stem cells.

• Multipotent stem cells play a critical role in development, tissue repair, and defense processes.
• Spinal cord injuries, bone fractures, autoimmune diseases, rheumatoid arthritis, haematological abnormalities, and fertility preservation have all been treated with multipotent stem cells.

Read the article on the National Health Policy!

Only bone marrow-derived blood stem cells can be used to treat various blood diseases and blood malignancies both in India and internationally. Research is still being conducted on the clinical application of stem cells for any additional diseases or stem cell types.

Despite the hype around stem cell therapies, only the blood-forming (hematopoietic) stem cells from bone marrow or umbilical cord blood are being employed on a regular basis to treat various blood diseases and cancers. Hematopoietic stem cell transplant (HSCT) or bone marrow transplant (BMT) is what this is.

According to NGSR 2017, making commercial claims about stem cell therapy as a treatment for any illness is unethical, malpractice, and in violation of the current National Guidelines for Stem Cell Research.

Key Regulations Governing Stem Cell Therapy in India

There are no laws governing the use of stem cells in India.

• The Department of Biotechnology and the Indian Council of Medical Research jointly developed “National Guidelines for Stem Cell Research,” which was released on October 11 by the Honorable Minister for Health & Family Welfare.
• The New Drugs and Clinical Trials (Amendment) Rules, 2022 were released by the Department of Health and Family Welfare by notification on January 13, 2022. The amendment expanded the definition of novel medications to include products made from cells or stem cells.
• The “New Drugs and Clinical Trial Rules, 2019” were announced by the Union Health Ministry in March 2019, and they specify that stem cell-derived products are to be used as “new drugs.” This implies that every physician using stem cell therapy must obtain government approval.
• The ICMR issued Guidelines for Stem Cell Research as a National Guideline for Stem Cell Research in 2017, which describes restricted, forbidden, and permitted research as well as minor, significant, and massive alteration. Furthermore, Annexure III of the guideline contains the indications that do not need prior clearance as in the transplantation of stem cells for certain blood diseases.
• The Indian Council of Medical Research, which only recognises stem cell therapies for specified disorders, has issued recommendations that other treatments are regarded as experimental and should not be used as therapy.
• The National Guidelines for Stem Cell Research 2017, India amended Stem Cell Research (SCR) Regulations. The Department of Biotechnology and the Indian Council of Medical Research worked together to draught it. The new rules are a part of an ongoing effort to address perceived issues in the field of SCR as well as scientific and technical ones. By actively including all stakeholders, it aims to facilitate safe, moral, and controlled translational and clinical SCR.
• The Drugs and Cosmetics Act, which governs the clearance and usage of medications in India, was modified by the health ministry in an effort to change this. Stem cells are not currently regarded as medications.
• According to the ICMR recommendations, any use of stem cells in patients other than those who have already been given permission must only be carried out as a clinical trial that has been approved and is closely supervised with the aim of advancing research and medicine and should not be administered as a form of treatment.

Amendments to the New Drugs and Clinical Trial Rules, 2019

• The New Drugs and Clinical Trials (Amendment) Rules, 2022 were released by the Department of Health and Family Welfare by notification on January 13, 2022. The amendment expanded the definition of novel medications to include products made from cells or stem cells.
  • In the process of registration of the ethics committee (EC) for clinical trials, if the application is submitted and no communication is received from Central Licensing Authority (CLA) within 45 days, the registration of EC is deemed to be granted by CLA.
  • This registration is legally valid for all purposes and the applicant can initiate clinical trials as per the rules.
• The EC is required to abide by the new rule’s standards and submit a report to the Central Licensing Authority (CLA).
• Sections of this document include definitions, applicable chapters and schedules for ECs, changes related to the registration of clinical studies and biomedical and health research, changes related to the constitution, functions, and procedures, and changes related to ECs’ responsibility for clinical trials, record-keeping by ECs, suspension and cancellation of EC registration, post-trial access to drugs, and clarifications related to accrediting.

Read the article on the Public Health Challenges in India!

The debate surrounding the use of embryonic stem cells is the primary problem with stem cell therapy and research.

• Donors of oocytes are subject to some risk. With untested stem cell therapy, patients run the possibility of incurring negative effects.
• Some nations’ insufficient domestic legislation allows stem cell therapy to be commercialized without the appropriate oversight and transparency.
• Exorbitant service fees, financing of patient debt, underreporting of negative effects, etc. are a few effects.
• The current international guidelines for stem cell research do not offer the countries the political and legal clout necessary to pass laws. They are also of a voluntary character.
• IVF clinics get little regulation despite being acknowledged by international experts as a trustworthy source of embryos for stem cell harvest.
• India’s international reputation as a “country with an oversupply of embryos” is causing a great deal of worry.

Also, learn about Biofortification in detail here!

What is the Way Forward?

• It is necessary to adhere to the center’s rules. Despite the existence of regulatory frameworks, researchers, hospitals, and other healthcare professionals continue to use stem cells without obtaining the necessary authorization.
• It is essential to encourage the sharing of stem cell treatment trial findings. In an area like stem cell science, which is rapidly expanding and gaining a lot of media attention, development must be evidence-based.
• To safeguard patients from experimental treatments that are promoted by profit-driven clinics, it is essential to raise knowledge of the real advantages and restrictions of stem cell therapy.
• To dispel the misconception that India acts as an “embryo supplier” for dubious research, regulation of IVF clinics is essential.
• Medical establishments that are permitted to offer stem cell therapy must be certified.

We hope that all your doubts regarding Stem Cells will be cleared after going through this article. You can download the Testbook App now to check out various other topics relevant to the UPSC IAS Exam.