STEM CELLS:BUILDING BLOCKS BRING NEW LIFE

Understand how these building blocks bring new life

Stem cells are incredibly special because they have the potential to become any kind of cell in the body, from red blood cells to brain cells. They are essential to life andgrowth, as they repair tissues and replace dead cells. Skin, for example, is constantly replenished by skin stem cells. Stem cells begin their life cycle as generic, featureless cells that don’t contain tissue-specific structures, such as the ability to carry oxygen. Stem cells become specialised through a process called differentiation. This is triggered by signals inside and outside the cell. Internal signals come from strands of DNA that carry information for all cellular structures, while external signals include chemicals from nearby cells. Stem cells can replicate many times known as proliferation while others such as nerve cells don’t divide at all. There are two stem cell types, as Professor Paul Fair child, co-director of the Oxford Stem Cell Institute at Oxford Martin School explains: “Adult stem cells are multipotent, which means they are able to produce numerous cells that are loosely related, such as stem cells in the bone marrow can generate cells that make up the blood,” he says. “In contrast, pluripotent stem cells, found within developing embryos, are able to make any one of the estimated 210 cell types that make up the human body.” This fascinating ability to transform and divide has made stem cells a rich source for medical research. Once their true potential has been harnessed, they could be used to treat a huge range of diseases and disabilitie

Stem cells have been used to restore the sight of patients suffering from certain forms of blindness

How to grow a stem cell Fertilised human embryos that have been donated for research have plenty of stem cells inside them as the cells are yet to fully form. Scientists extract the cells and put them into a culture dish. This is fi lled with a culture medium, which is a mixture of nutrients that encourages the cells to divide and grow. As the cells divide they are placed into multiple dishes, each trying to complete an embryonic stem cell line. If a line is completed, it can then be used for further research and development

Cloning cells 

Scientists can reprogram cells to forget their current role and become pluripotent cells again indistinguishable from early embryonic stem cells. These are called induced pluripotent stem cells (IPSCs) and can be used in areas of the body where they are needed, taking on the characteristics of nearby cells. IPSCs are more reliable than stem cells grown from a donated embryo because the body is more likely to accept stem cells generated by itself. IPSCs can treat degenerative conditions such as Parkinson’s disease and baldness, which are caused by cells dying without being replaced. The IPSCs fi ll those gaps, restoring the body’s systems. Professor Fairchild says IPSCs could help find a cure for certain disorders: “By deriving these cells from individuals with rare conditions, we are able to model the condition in the laboratory and investigate the effects of new drugs on that disease.“