Stem Cells Current Affairs - 2019
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Scientists for first time have successfully grown oesophageal organoids, a miniature, functional versions of human food pipe using pluripotent stem cells (PSCs) in laboratory. This bioengineered oesophageal organoids paves way for new ways to study and test drugs against gut disorders. It may also lead to personalised diagnostic methods and focused in part on developing regenerative tissue therapies to treat or cure GI disorders. It will help to study birth defects like esophageal atresia, organoids, eosinophilic esophagitis and Barrett’s metaplasia. Moreover bioengineer genetically matched esophageal tissue can be also transplanted in individual patients.
It is long muscular tube part of digestive system that connects mouth to stomach to actively pass food. It is also called as gastro-intestinal tract (GI tract or gullet or food pipe). It is around 25cm long in adults. After food is swallowed walls of oesophagus squeeze together (contract) and moves food down to the stomach. The area where oesophagus joins stomach is called gastro-oesophageal junction.
Oesophagus has four layers:
- Mucosa – inner layer, which is moist to help food pass smoothly into stomach.
- Submucosa –Contains glands that produce mucus (phlegm), which keeps oesophagus moist.
- Muscularis – It is muscle layer, which pushes food down to stomach.
- Adventitia – It is outer layer, which attaches oesophagus to nearby parts of body.
Oesophagus can be affected by congenital diseases, such as oesophageal atresia, a medical condition causing narrowing or malformation of oesophagus due to genetic mutations. Other diseases related to it includes oesophageal cancer, gastroesophageal reflux disease (GERD), or rare ailment called achalasia, a disease affecting muscles of lower oesophagus that prevents contraction of organ and passage of food.
Stem cell is undifferentiated cell of multicellular organism which is capable of giving rise to indefinitely more cells (through mitosis) of same type and from which certain other kinds of cell may be formed by the cellular differentiation. There are two types of stem cells widely used
- Embryonic stem cells: They come from human embryos that are three to five days old. They are harvested during process called in-vitro fertilization. They are known as pluripotent stem cells. These cells can give rise to virtually any other type of cell in the body.
- Induced pluripotent stem cells (iPSCs): They can differentiate into all types of specialized cells in body. They can potentially produce new cells for any organ or tissue.
Scientists from Duke University in North Carolina, US for first time have developed working human skeletal muscle from stem cells in the laboratory.
Stem cells are undifferentiated biological cells that can differentiate into specialized cells and can divide to produce more stem cells. They are found in multicellular organisms. In mammals, there are two broad types of stem cells: embryonic stem cells and adult stem cells. Embryonic stem cells can be isolated from the inner cell mass of blastocysts and adult stem cells are found in various tissues which can act as a repair system for the body, replenishing adult tissues.
Scientists had developed human skeletal muscle using adult skin or blood cells that were reprogrammed into a juvenile, versatile state. These cells were induced pluripotent stem cells (iPSCs) which can become any other type of human cell like naturally-occurring stem cells found in embryos.
In this case, the iPSCs were coaxed into becoming skeletal muscle cells. The breakthrough was made possible by unique cell culture conditions in lab and special 3-D scaffold which allowed cells to grow much faster and longer.
The tissue contracted and reacted to external stimuli such as electrical pulses or chemical signals. It was also implanted into adult mice, where it survived and functioned for at least three weeks.
The development is breakthrough that holds promise for sufferers of degenerative muscular diseases. This technique will allow scientists to grow endless amount of functioning muscle in lab to test to test drugs and gene treatments for degenerative diseases.