Can mitochondria multiply? | Mitochondria

Can mitochondria multiply?

In principle, the organism can regulate the production of mitochondria up or down. The decisive factor for this is the current energy supply of the organ in which the mitochondria are to be multiplied. A lack of energy within these organ systems ultimately leads to the development of so-called growth factors via a cascade of different proteins that are responsible for registering the lack of energy.

The best known of these is PGC -1-α. This in turn ensures that the cells of the organ are stimulated to form more mitochondria to counteract the energy deficiency, since more mitochondria can also provide more energy. In practice, this can be achieved, for example, by adjusting the diet.

If the body has few carbohydrates or sugars available to provide energy, the body switches to other energy sources, such as fats and amino acids. However, since their processing is more complicated for the body and energy cannot be provided so quickly, the body reacts by increasing the production of mitochondria. In summary, a low-carbohydrate diet or a fasting period coupled with strength training strongly stimulates the formation of new mitochondria in the muscles.

Diseases of the mitochondria

Mitochondrial diseases are mostly due to defects in the so-called respiratory chain of the mitochondria. If our tissues are supplied with sufficient oxygen, this respiratory chain is responsible for ensuring that the cells here have sufficient energy to perform their functions and keep themselves alive. Accordingly, defects in this respiratory chain in their final sequence mean the death of these cells.

This cell death is particularly pronounced in organs or tissues that depend on a constant supply of energy. These include skeletal and cardiac muscles and our central nervous system, but also the kidneys and liver. Those affected usually complain of severe muscle pain after exertion, have reduced mental abilities or may suffer from epileptic seizures.

A kidney dysfunction can also occur. The difficulty for the doctor is to interpret these symptoms correctly. Since not all mitochondria in the body, and in some cases not even all the mitochondria of a cell, have this disturbed mitochondrial function, the manifestations can vary greatly from one individual to another.

In medicine, however, there are established disease complexes in which several organs are always affected by malfunctions. These diseases are usually diagnosed by means of a small tissue sample taken from a muscle. This tissue sample is examined microscopically for abnormalities.

If so-called “ragged red fibres” (a clumping of mitochondria) are present, these are a very strong indication of the presence of a mitochondrial disease.In addition, the components of the respiratory chain are often examined for their function and the mitochondrial DNA for mutations using sequencing. Treatment or even cure of mitochondrial diseases is currently (2017) not yet possible.

  • In Leigh syndrome, for example, cell death occurs in the area of the brain stem and damage to peripheral nerves. As the disease progresses, organs such as the heart, liver and kidneys also become susceptible and eventually cease to function.
  • In the symptom complex of myopathy, encephalopathy, lactate acidosis, stroke-like episodes, or MELAS syndrome for short, the affected person suffers from cell defects in skeletal muscles and the central nervous system.