Context: In a world first, six children with a rare disorder caused by deletions in the genomes of their mitochondria– the cellular compartments essential for energy generation- have been successfully treated with donor mitochondria from their mother.

• The process involved the mitochondrial transplant from donor mothers into children’s haematopoietic stem cells, which give rise to all types of blood cells.

About Stem Cell-derived Mitochondria Transplantation

• It involves the spontaneous mitochondrial transfer of the stem cell to rescue the injured cells or the injection of stem cell isolated mitochondria into the injured area to repair the damage.

• Stem cells are the most primitive cells at the top of the origin of cell lines, and they have a high capacity for differentiation and self-renewal.

• In addition, stem cells can differentiate into various tissues, organs, or functional cells of the human body; therefore, stem cells hold great promise for therapeutic tissue engineering and regenerative medicine.

About Mitochondrial replacement therapy (MRT)

• Mitochondrial replacement therapy (MRT), sometimes called mitochondrial donation, is the replacement of mitochondria in one or more cells to prevent or ameliorate disease.

• MRT originated as a special form of in vitro fertilisation in which some or all of the future baby’s mitochondrial DNA (mtDNA) comes from a third party.

• This technique is used in cases when mothers carry genes for mitochondrial diseases.

• The therapy is approved for use in the United Kingdom.

• A second application is to use autologous mitochondria to replace mitochondria in damaged tissue to restore the tissue to a functional state.

• This has been used in clinical research in the United States to treat cardiac-compromised newborns.

What is Mitochondria?

• It was first described by a German pathologist named Richard Altmann in the year 1890.

• Popularly known as the “Powerhouse of the cell,”mitochondria are a double membrane-bound organelle found in most eukaryotic organisms.

• They are found inside the cytoplasm and essentially function as the cell’s “digestive system.”

• They play a major role in breaking down nutrients and generating energy-rich molecules for the cell.

• Many of the biochemical reactions involved in cellular respiration take place within the mitochondria.

Functions of Mitochondria

• The most important function of mitochondria is to produce energy through the process of oxidative phosphorylation.

• It is also involved in the following process:

• Regulates the metabolic activity of the cell

• Promotes the growth of new cells and cell multiplication

• Helps in detoxifying ammonia in the liver cells

• Plays an important role in apoptosis or programmed cell death

• Responsible for building certain parts of the blood and various hormones like testosterone and oestrogen

• Helps in maintaining an adequate concentration of calcium ions within the compartments of the cell

• It is also involved in various cellular activities like cellular differentiation, cell signalling, cell senescence, controlling the cell cycle and also in cell growth.

• Mitochondrial diseases: Alpers Disease, Barth Syndrome, Kearns-Sayre syndrome (KSS).