The
successful growth of these stomach tissues in a Petri dish highlights a whole
range of new possibilities that can now be achieved.
‘Miniature version of stomach grown in the lab will provide clues to better treatment strategies for gastrointestinal diseases.’
Dr.
Jim Wells who is the principal investigator for the study stated that now that
they could grow both the antral and the corpus/ fundic type gastric mini organs
of humans,
It is therefore possible
to study interactions between human gastric tissues and identify how they will
react to infection, damage as well as to drugs. Such information can be used to
study diseases that affect the stomach and also identify the pathway involved
in gastric cancer..
The
latest study is a continuation of studies that began in the year 2010 by a
research team led by Dr. Well when pluripotent stem cells were used to grow
human stomach and intestines. The tissues are being used to identify the causes
as well as possible treatment involved in human gastrointestinal tract.
As
a part of their previous study, the scientists grew human intestine that
included an enteric nervous system. These tissues are highly functional and
were able to absorb nutrients and display peristalsis, which is the distinctive
movement of the intestine to move the food from one end of the GI tract to the
other.
Dr.
Well's laboratory is also looking intently at understanding how embryonic development
which includes the development of stomach, pancreas, esophagus and intestines.
The data obtained can also be used for devising treatment strategies for
genetic diseases that include
Hirschsprung's disease as well as monogenic
diabetes.
Beginning of the Study
The
growth of mini organs in the lab, also called
organoids or miniature
versions of organs was initially a daunting task as it posed a lot of
conditions. The first step was to identify a culture medium into which
mechanical constraints could be applied for the development of the different
cells in the organ from stem cells so that they can be organized into layers to
form an organ-like structure as opposed to a simple layer of cell aggregates.
The
research team under Dr. Well lacked a basic understanding of how stomach
developed from the embryonic stage which was a significant challenge for the
team. Dr. Wells explained that they could not grow stomach tissue in the Petri
dish without first identifying how the stomach grows from the embryo.
The
initial step involved the use of mice from which the genetics of embryonic
development of stomach was determined, which laid the foundation for the
current study on growing stomach tissues.
WNT/β-catenin
The
scientists, using their study on mice, found out that there was a basic genetic
pathway WNT/β-catenin which was vital in determining the development of the
corpus/fundus region of mouse stomach tissue that were developed from mouse
embryos. This study was used to alter the WNT/β-catenin pathway to grow human
fundus mini organs
which were developed form pluripotent stem cells.
Refining the Process
Dr.
Wells and his research team then refined the growth and development process by
identifying other pathways which could induce the formation of vital stomach
cell types of the fundus region.
The cell types that were developed also
included major cells like the cells that were involved in the production of the
key digestive enzyme pepsin along with parietal cells. The parietal cells
are involved in the secretion of hydrochloric acid that is essential for
digestion and is also an intrinsic factor that aids the intestines in the
absorption of vitamin B-12. This is a key step that is necessary for the
production of blood cells as well as for the development of a nervous system
which is healthy.
When
asked how long it took for the stem to grow into gastric-fundus tissues in a
Petri-dish, Dr. Wells responded by saying that it took six weeks.
Benefits of the Study
- Provides a chance
to study the development of the stomach tissue from stem cells
- It can be used to
study gastric cancer in humans
- It can be used to
understand how the organoids
will respond after infection with Helicobacter pylori (H.pylori)
- H. pylori can
lead to the development of stomach ulcers, chronic gastritis and increase
the risk for stomach cancer
The
stomach tissue mini organs that were grown can be integrated with mini
intestine organs to find out how the digestive process occurs and to understand
nutrient uptake. The gastrointestinal system can be better visualized which
includes analysis of inflammatory diseases, uptake of drugs, studying the
effect of helpful microbes along with pathogens. It would provide a better
understanding of gastrointestinal mobility disorders.
References :- Scientists create "mini-organs" in vitro - (http://www.genethique.org/en/scientists-create-mini-organs-vitro-63700.html#.WGyQcFN97IU)
Source: Medindia
