A group of US scientists reported on Wednesday that they have isolated stem cells from human skin, cultivated them in the laboratory, and differentiated them into fat, muscle and bone cells.

The study, published in the journal Stem Cells and Development, is the first to show the ability of a single adult stem cell to become multiple tissue types, according to Anthony Atala, director of the Wake Forest Institute for Regenerative Medicine who led the research.

"Because these cells are taken from a patient's own skin, there would not be problems with organ or tissue rejection. These cells can provide a valuable resource for tissue repair and for organs as well," said Atala.

The researchers grew mesenchymal stem cells (MSC), a type of stem cell normally found in bone marrow. They were able to isolate single stem cells using tissue samples from 15 donors.

Then, they grew the stem cell in culture dishes in the laboratory. The scientists used hormones and growth factors to coax the stem cells into becoming fat, muscle and bone cells.

When the differentiated cells were seeded onto three- dimensional molds and implanted in mice, they maintained features consistent with bone, muscle and fat tissue.

"Progeny of cell lines established from a single dermal MSC could be differentiated into adipogenic, osteogenic and myogenic lineages, consistent with the conclusion that we established a clonal, multipotential, somatic MSC cell line," wrote the researchers.

The promise of stem cells lies in their ability to develop into specialized types of cells and to replicate themselves. Scientists hope to harness the potential of stem cells and use them to replace damaged cells and tissue in conditions such as spinal cord injuries, diabetes, Alzheimer's disease, stroke and burns.

Most scientists believe that stem cells from human embryos are the most versatile type of stem cell because they have the potential to form any cell or tissue in the body. But they are also exploring the potential of stem cells from adults. In addition to skin, the cells have been identified in bone marrow, the brain and blood from the umbilical cord.

Compared to bone marrow, a skin biopsy is easy to take, so it offers advantages for clinical use. The cells can be obtained from any small sample of human skin, the researchers noted.

Next, the research team hopes to test the function of the tissue that was created from the stem cells in long term.

"Clonal growth of MSCs presents profound implications in our understanding of differentiation and development, and should provide a valuable resource for tissue repair," their paper said.

The cells have potential to be used both in cell therapy and tissue engineering, namely the science of growing tissues and organs in the laboratory. For cell therapy, laboratory-grown cells would be injected into the body to replace breast tissue removed by surgery, to fill in the gaps in bone fractures or replace muscle damaged by injury.

"The ability to engineer tissues from a patient's own cells may overcome two major problems in transplantation medicine: immune rejection and tissue shortage," Atala said.

Source: Xinhua