Researchers have discovered how cells communicate with each other during times of cellular injury. The findings shed new light on how the body repairs itself when organs become diseased, through small particles known as micro vesicles, and offers hope for tissue regeneration.
These particles are several times smaller than a normal cell and contain genetic information such as messenger ribonucleic acid (RNA), other species of RNA and protein. The paper shows a novel mechanism by which the cells communicate with each other through these micro vesicles. During times of cellular injury or stress, or with certain diseases like cancer, infections and cardiovascular disease, these particles are shed and then taken up by other cells in the body. The genetic information and protein in the micro vesicles helps to reprogram the accepting cell to behave more like the cell from which the particle was derived.
What the researchers’ attempted to understand is how cells within the bone marrow are able to repair organs that are unrelated to those bone marrow cells, such as the lung. The study suggests that when the lung is injured or diseased and cells within the lung are stressed or dying, they shed micro vesicles. Those micro vesicles are then consumed by cells within the bone marrow, including stem cells, which are present in small numbers within the circulatory system. Those bone marrow cells then turn into lung cells.
Other researchers have reported similar findings over the last couple of years; however, micro vesicles have been known about for over 40 years and have often been considered irrelevant. The researchers’ are recognizing the relevance of micro vesicles: They are important mediators of cell-to-cell communication. It has been found that micro vesicles not only supply information to stem cells with lung injury, but this process also occurs in other organs as well, like the heart, liver and brain.
The researchers report unique findings, noting that the change in those stem cells that have consumed micro vesicles made by injured lung cells is very stable -- the change appears to be permanent. Stem cells are reprogrammed due to the transfer of micro vesicle-based transcription factors. These factors cause cells to behave atypically.
Among the practical implications from the findings is an understanding of the mechanism of tissue repair and determining whether or not micro vesicles can be used in a therapeutic fashion. |
