Stem Cell Used To Make New Liver Tissue

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Stem Cell Used To Make New Liver Tissue

Bone marrow may hold master cells that could

some day be used to repair failing livers.

In a study published in Science, scientists at the University

of Pittsburgh Medical Center report that research shows that stem

cells in bone marrow are capable of converting themselves into

functioning liver tissue cells. Stem cells are " pluripotent " cells

that have the capacity to differentiate into any of the many

different types of cells that together form the human body. Stem

cells have the capacity to replicate themselves while remaining in

the undifferentiated state, thus providing a potentially unlimited

source of cells for medical and scientific purposes.

The study, conducted by Bryon , is the first step

toward understanding how to rescue failing livers using the body's

own stem cells. The experiments have shown that, under special

conditions, injecting the special marrow cells into rats causes the

animals to form new liver tissue.

Although the research has been demonstrated only in laboratory

animals, other studies strongly suggest that humans also have bone

marrow cells that will convert into liver cells. However, perfecting

the technique for humans may take up to ten years.

Researchers have been trying with very little success to find

stem cells in the liver that could make new tissue. If the cells can

be isolated from the bone marrow and cultured, the process raises the

possibility of an unlimited supply of fundamental liver cells.

Some patients with failing livers recover after the organ

spontaneously grows new cells. The liver often generates new healthy

liver cells after an injury or disease. Studies have also shown that

some patients who do not make new hepatocytes still end up growing

new liver tissue and recovering. Stem cell research may unlock the

long-standing mystery of why this occurs and offer hope to patients

whose only recourse has been organ transplant. Stem cell technology

could lead to cells that can regenerate their tissues, making organ

transplantation unnecessary for survival.

In the study, sen and his colleagues destroyed the bone

marrow of female rats and replaced it with marrow from male rats.

This meant that the female rats had bone marrow that carried the male

Y chromosome, which could be used to identify cells. The scientists

treated the female rats with a chemical that prevented their livers

from regenerating and then damaged the livers, mimicking an injury.

Two weeks later, when livers were removed, the researchers found they

contained new liver cells that carried the Y chromosome marker. These

results indicated that the cells from the bone marrow had gone to the

failing livers and started the regeneration of essential liver cells.

This suggests that there is a stem cell in the adult bone marrow that

is capable of becoming any cell you need if it receives the right

signal. Stem cells from the bone marrow might be able to signal the

production of any type of cell needed. Once researchers learn to

isolate specific stem cells from the bone marrow, switch them into

the needed cells, and then grow them into large quantities, it may be

possible to save failing organs with simple injections.

This research is very important for not only autoimmune liver

disease but also all autoimmune diseases that destroy vital organs.

It will help researchers understand how to regenerate organs rather

than use transplanted organs that are in very short supply and

require the patient to be treated with immunosuppressants for the

rest of their lives following transplant. At the present time, organ

transplant is the only option for severe organ-specific autoimmune

diseases, such as autoimmune liver disease, lupus nephritis, and

pulmonary fibrosis in scleroderma.

Sources for this article: Science, Intellihealth, and The Decade of

Autoimmunity, edited by Yehuda Shoenfeld