UPSC Express

About Stem Cells

• The most basic unit of any organism is a cell.
• It is the smallest unit of life that can function independently and perform all the necessary functions of life.
• Cells develop to form tissues which inturn develop to form organs.
• Further broadly speaking, cells are of two types, differentiated and undifferentiated.
• Differentiated cells are the building blocks of tissues and organs and are specialised to from that tissue or organ.
• Undifferentiated cells are those that have the potential to deleop into many different types of cells like those in muscles, kidney, liver etc.
• Stem cells are basically these undifferentiated, primitive cells.
• Further Stem cells are of two types, Embryonic and Adult/Somatic stem cells.

Difference between Embryonic and Adult/Somatic stem cells

• Embryonic stem cells are derived from embryos.
• They are totipotent in that they can be differentiated into most of the cell types.
• They can produce a clone of the entire organism.
• Somatic stem cells or adult stem cells are undifferentiated cells present in differentiated cells in a tissue or organ.
• They help in repair and maintenance of specific tissue or organ where they are present.

Induced Pluripotent Stem cells (iPS cells) and their significance

• iPS are adult stem cells, like in umbilical cord cells or bone marrow cells, that can be induced to show properties of stem cells.
• They are mostly use in therapeutic cloning to treat degenerative diseases like diabetes, Parkinson’s, Alzhiemers etc.
• They are created by stimulating mature, already specialised cells back into a juvenile state without the need for an embryo.
• These can be derived from the patient themselves, making them less likely to be rejected.
• The cells can be transformed into a range of different types of cells, and their use is a key sector of medical research.
• Further owing to ethical issues embryonic cells are banned in countries such as Ireland and in Latin America.
• Therefore use of iPS cells in therapeutic cloning is rather significant.

Significance of stem cell therapies

• Currently available therapies for Parkinson’s disease treat symptoms without slowing or halting the disease progression.
• On the other hand, the new research aims to actively reverse the disease.
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