Bone and Nerve Cells from the Placenta

Introduction

Special placental cells have recently been cultured into nerve and bone cells, a breakthrough that may pave the way to a regenerated cellular tissue bank for the treatment of otherwise incurable disease. The development has come from a blood storage facility that has been offering umbilical cord blood for medical treatment of leukemia and other disease. The day may not be too far away, when placentas are used to treat hard-to-cure ailments such as bone cancer and Parkinson's disease, which damages nerve cells.

It has been known that mesenchymal stem cells, which develop into bone and nerve cells, exist in bone marrow. The Institute of Medical Science at Tokyo University discovered that mesenchymal stem cells also exist placental villi, tiny branchlike structures that supply oxygen and nutrition to a baby in the womb while carrying off carbon dioxide and metabolic by-products. Dr. Takahashi of cell processing section developed a combination of medicines to enhance the growth of placental mesenchymal stem cells into nerve cells. After 24 hours of cultivation, about 30 percent of the mesenchymal stem cells became nerve cells. Calcium was detected from another group of cultivated mesenchymal stem cells, which indicates the formation of bone cells.

Stem cells extracted from embryos have attracted worldwide attention but the use of embryonic stem (ES) cells for medical studies has raised intense ethical debate on the social acceptability of experimenting with fertilized eggs that could grow to become a baby. But the use of mesenchymal stem cells does not raise that kind of problem, because the cells have been abandoned after serving their natural purpose. Also, if they are stored in advance and the type of human leukocyte antigen matches that of recipient, anyone can receive the cells. However, mesenchymal stem cells can develop into limited kinds of cells such as bone and nerve cells, whereas the ES cell can become cells of the liver, pancreas and all other internal organs. Research is being conducted to evolve a practical use of the method for human medical treatment.

If the safety and effectiveness of the method is ensured, cord blood banks may offer new medical materials to patients with various kinds of hard-to-cure diseases. It was often believed that the placenta was a treasure box containing stem cells that could become various cells and organs, and the results have upheld this belief. Although the practical applications would be realized in due course, the culturing of bone and nerve cells from placenta is a major step forward in regenerative medicine as it paves the way for utilizing placentas, which are now a medical waste product.

Regenerative medicine is a field in which researchers aim to produce human tissues and organs from human cells and genes to use them for medical treatment. In-spite of the ethical resistance, researchers all over the world are studying ES cells extracted from fertilized eggs as the ultimate resource cells. In March '02 Japanese government approved the production of ES cells. But mainstream studies use mesenchymal stem cells from bone marrow, instead of embryonic stem cells, to produce bone and nerve cells. The technique has already seen practical use. For example, researchers at Nara Medical University produced bone pieces using the technique and transplanted one to a patient suffering from a disease that deforms bone joints. This finding of mesenchymal stem cells inside the placenta (and its successful culturing to bone and nerve cells) may help cope with the shortage of cells as input material for that kind of treatment.

Contact for more information

Science & Technology Wing Embassy of India
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Tokyo 102-0074, Japan
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