It’s well known that chronic alcoholics have many problems. Recently Russian scientists have found another alcoholic trouble – these poor people have mitochondria moving to cell nucleus. The consequences are simple –the cell dies.
Scientists from MSU Belosersky Institute of Physico-Chemical Biology Bioenergy Dept under supervising of academician V.P. Skulachev have performed an electron-microscopic research of cardiac muscle cells (cardiomyocytes), which showed that under some heart pathologies cell nuclei might contain mitochondrial clusters. The scientists have developed a new technique in order to explore such a rare phenomenon. This technique allows producing tons of nuclei full of mitochondria. Mitochondria always come to cardiomyocyte nuclei of alcoholic rats.
The cell is a very complex polyfunctional object with its own geography. Everything should be on its place for the cell to work. Cell nucleus is a cell capital or DNA depot. Mitochondria are cell’s power stations, which are autonomous. They form active oxygen, which is able to oxidize DNA, so they are unwanted guests in the nucleus, because of possible negative and dangerous effects. Moreover, a mitochondrion contains proteins launching apoptosis (programmed cell death). So, when mitochondria enter the nucleus, they destroy DNA, as well as cell proteins. In general, appearance of mitochondria in nucleus is similar to building nuclear power plant in the Kremlin. Anyway, it happens.
Mitochondria in cell nucleus have been first noticed in 1958, H. Hoffman and G. Grigg, Australian electron microscopists, when they observed utrathin slices of adult mice lymph nodes. Later other researchers have detected mitochondria in nuclei of various cancer cells and cardiacs’ cardiomyocytes. But nucleus invasion was a rare phenomenon – the overwhelming majority of nuclei have escaped the invasion. That’s why the nature of this phenomenon remains almost unexplored for 40 years.
Scientists from Moscow have learned to put mitochondria when they need it. All you need to do is to find an alcoholic rat. If you keep animals on a liquid ethanol diet (alcohol shares 36% of all calories consumed) and at the same time infuse an alcoholic intoxication intensifying substance, rats surely get alcoholic cardiomyopathy in twelve weeks. Four out of five rats had mitochondria in cardiomyocyte nuclei.
The researches have analyzed tons of electronic microphotographs and concluded that they were dealing with cells, which were going to die (cells were at the primary stage of apoptosis). Meanwhile the mitochondrial network that pierces the cell splits to single mitochondria, which start moving towards the nucleus. Their centripetal movement ends in the nucleus. According to the scientists, a small site of nuclear membrane breaks for a moment, and mitochondria enter the nucleus before the gap closes. Then mitochondria swell and lose their membranes being inside the nucleus. Nothing can stop caustic mitochondrial enzymes from pouring into the nucleus and finally killing the cell.
All these facts evidently require further experimental testing, but even abovementioned horror is enough (nondrinking persons’ opinion) to put alcoholics in the right way. If they don’t, mitochondria will come to them in their dreams…