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Pet care
Research development
In 1996 Dolly the sheep was produced at the
Roslin Institute (Scotland) as part of research into
producing medicines in the milk of farm animals.
Researchers have managed to transfer human genes
that produce useful proteins into sheep and cows,
so that they can produce, for instance, the blood
clotting agent to treat haemophilia.
Several clones had been produced in the lab before
Dolly, e.g. frogs and mice which had all been cloned
from the DNA from embryos, but Dolly was the first
mammal to be cloned from an adult cell. This was a
major scientific achievement as it demonstrated that
the DNA from adult cells, despite having specialised
as one particular type of cell, can be used to create
an entire organism.
Dolly became infamous and the world suddenly
realised the potential for the manipulation of
biological cells.
Whilst work was progressing on cloning, research
started in 1981 on deriving embryonic stem cells
from animals and in 1998 from humans. Stem cells
are important for living organisms for many reasons.
In the 3- to 5-day-old embryo, the inner cells give
rise to the entire body of the organism, including all
of the many specialized cell types and organs such as
the heart, lungs, skin, sperm, eggs and other tissues.
In some adult tissues, such as bone marrow, muscle,
and brain, discrete populations of adult stem cells
generate replacements for cells that are lost through
normal wear and tear, injury, or disease.
Cell types and function
Stem cells possess two unique properties and are
able to both maintain an undifferentiated state by
self-renewing (i.e. generating identical daughter
stem cells) and differentiate into mature cell types
(i.e. generating more specialised daughter cells
capable of forming distinct tissue types).
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Cell-based therapies
for regenerative
medicine
Disease modelling
Transgenic animal
generation
Biomarker
development, drug and
toxiticity screening
Induced
pluripotent
stem cells
Human organ
generation in
domestic animals
PETS International September 2016
Biodiversity
preservation
Basic research
Gametes and/or
embryo derivation
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Pet care
Pet
Application
Conclusion
Cat
Therapy for feline chronic kidney disease
Longer trials needed, no immediate effect
Feline chronic gingival stomatitis (dentistry)
Research shows clinical improvements
Treat osteoarthritis
Improved limb function within 3 months
Treat myocardial diseases
Science still developing
Treat inflammatory bowel disease
Produced clinical benefits, long-term studies
being undertaken
Regenerative medicine (tendon joint repair)
Ongoing long-term trials
Repair tendon lesions
Effective tendon repair
Dog
Horse
Stem cells have been categorised by their
characteristics into three groups; embryonic
stem cells (ESCs), adult stem cells and induced
pluripotent stem cells (iPSCs). ESCs and iPSCs possess
pluripotency properties and are able to differentiate
into all cells of all three germ layers: ectoderm,
endoderm and mesoderm. Whereas, adult stem cells
possess more restricted differentiation capabilities
and may possess multipotent, oligopotent and
unipotent properties.
Adult stem cells are only able to differentiate into a
limited number of different cell types. For example,
mesenchymal stem cells (MSCs) are multipotent
and are able to differentiate multiple cell types of
mesoderm origin including chondrocytes, osteoblasts
and adipocytes. There is a shift of conducting
research into using adult derived stem cells as they
alleviate ethical and practical issues associated
with ESCs and iPSCs. Adult stem cells, especially
MSCs, were among the first stem cells used in cell
transplantation therapies in animals. This is because
MSCs also possess immunomodulatory properties
where they respond to both the adaptive and innate
immune systems by supressing T cells and dendritic
cell (DC) maturation, decreasing B cell activation and
proliferation. MSCs are found in various tissues and
organs including bone, skeletal muscle, cartilage and
adipose tissue but the cells are mostly isolated from
bone marrow.
Opportunities for pet treatment
The unique properties of stem cells allow the
opportunities to be used in tissue regeneration for
treating numerous animals with various ailments.
Over the past 15 years there has been great interest
in the field of regenerative medicine with the focus on
regenerating and replacing cells, tissues and organs
to restore functionality, using the body’s own repair
mechanisms. Cell and tissue regeneration may be
achieved by using the combination of engineered
scaffolds, cells and biomolecules, to stimulate
regeneration of the defective area with a view to
producing functional tissues.
This explosion of research into regenerative medicine
has allowed vast improvements and advancements
in their use within biomedical science. The potential
use of MSCs in cell therapies for treating animals has
been steadily gaining momentum, due to their diverse
range of properties.
PETS International September 2016
John Adams
Consultant
[email protected]
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