The human body in adulthood must replenish its blood with as many as one hundred billion new red blood cells a day. That is a staggering number, but normal administration in the healthy adult.
Researchers have now identified one of the basic processes that is key to the formation of new red blood cells.
This finding is crucial in the resolution of some blood disorders like different types of anoemias, but also might enable scientists to create 'synthetic' blood and thereby eliminate the constant shortage, and with fewer side effects from it, of the blood supply.
A red blood cell, in itself, is just an envelope of haemoglobin essential for the transport of oxygen in the human body. The red blood cell begins in the bone marrow, where a stem cell controls its birth, its numbers and more importantly its diversity before it becomes in essence fully formed and identified in its role.
One of the most important steps is mitophagy, which is the elimination of the respiratory apparatus of the stem cell, the mitochondria. Poorly understood until now, this process is very important.
But scientists have just revealed that they have identified the so called zinc finger proteins, which together with a co-factor called KAP1 are the modulators of the process of mitophagy.
The process of mitophagy is as old as life on the planet, and is known as the 'silencer' of certain components of the mammalian genome known as retroelements. They were at their origin, viruses, and their code was incorporated in the mammalian genome after infection. Through evolution it then has become an element that functioned in several other processes. One of them was mitophagy.
Studies in the lab with mice showed that tampering with the KAP1 quickly made the mice anoemic and unable to produce more blood cells. The tampering with KAP1 in fact went to the very heart of the stem cell process of 'cell differentiation' at their birth. Eliminating KAP1 altogether has shown to have the same effect in humans, indicating that it has been preserved through evolution, from mice to men, as an essential player in blood formation.
The study also showed that mutations of the regulatory systems contributed to other blood diseases such as leukemia, which gives hope that the finding could bring about new cures for those pathologies too.
The finding also has a wider implicaiton for all mitochondrial function. Mitochondria are essential for the healthy function of many other type of cells aside from blood cells, and if they malfunction and produce free radicals they can contribute to the oxidative process which is known to increase the incidence of heart attacks, liver disease and obesity.
Source: ScienceDaily 3.16.13
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