Stem Cell Clinic

Proteins key in stem cell production identified

July 5, 2013 A team of Toronto-based researchers may be one step closer to a 'recipe' for large-scale production of stem cells for use in research and therapy.

Induced pluripotent stem cells (iPSCs) can be of great value for medical research because they can flexibly develop into many different types of cells. However, producing these cells is challenging because the proteins that control their generation are largely unknown.

But researchers from the University of Toronto, the Hospital for Sick Children and Mount Sinai Hospital (with colleagues from the United States and Portugal) say they have identified certain proteins that play a key role in controlling pluripotency, which may mean a potential breakthrough in producing these cells.

The findings were recently published in Nature. One of the authors is University of Toronto Engineering professor Brendan Frey. He said the researchers discovered the proteins using the splicing code developed a few years ago by a team led by he and U of T Donnelly Centre researcher Benjamin Blencowe. "The mechanisms that control embryonic stem cell pluripotency have remained a mystery for some time. However, what Dr. Blencowe and the research team found is that the proteins identified by our splicing code can activate or deactivate stem cell pluripotency," Frey said.

When asked why the identification of these proteins is important, Frey gave the following analogy: "Suppose you've tasted many wonderful gourmet dishes, but you have absolutely no idea what's needed to make them. Then, one day, you discover that there's something called a 'measuring cup' that is used by all of the gourmet chefs. Now you understand something important about how dishes are prepared, and you also know about a 'control knob' that can be turned in order to make different dishes, just as adjusting the amount of butter and flour will give a different kind of pastry."

And while a complete recipe for producing iPSCs may not be available yet, Frey said, it's beginning to look more likely.

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Proteins key in stem cell production identified

A First: Human Liver Created from Stem Cells

Scientists in Japan said they had grown human liver tissue from stem cells in a first that holds promise for alleviating the critical shortage of donor organs.

Creating lab-grown tissue to replenish organs damaged by accident or disease is a Holy Grail for the pioneering field of research into the premature cells known as stem cells.

Now Takanori Takebe of the Yokohama City University Graduate School of Medicine and a team reported Wednesday in the journal Nature that they grew tissue "resembling the (human) adult liver" in a lab mouse.

They first created induced pluripotent stem (iPS) cells which they mixed with other cell types and coaxed into "liver buds" -- the precursor clusters that develop into a liver. The buds, each about five millimeters (0.2 inches) big, were then transplanted onto a mouse brain, where they were observed transforming into a "functional human liver" complete with blood vessels, the scientists wrote.

"To our knowledge, this is the first report demonstrating the generation of a functional human organ from pluripotent stem cells," said the report.

The technique has yet to be tested in humans, but serves as an important proof of concept, it added.

Stem cells are infant cells that can develop into any part of the body. Until a few years ago, when iPS cells were created, the only way to obtain stem cells was to harvest them from human embryos. This is controversial because it requires the destruction of the embryo, a process to which religious conservatives and others object.

But iPS cells are easily obtainable mature cells that are "reprogrammed" into a versatile, primitive state from where they can develop into any kind of cell in the body. Takebe told a press conference ahead of the report's release that the man-made liver was observed through a replacement glass skull that was fitted around the mouse's brain.

The liver developed blood vessels which fused with those of the animal. It also performed certain human-specific liver functions -- producing proteins and processing specific drugs. "We have concluded that this liver is functioning," the scientist said. "We think this is enough for improving the survival after liver failure."

Scientists commenting on the research described it as promising.

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A First: Human Liver Created from Stem Cells

Stem cell center to open next month

BSALIM, Lebanon: In April, a German medical team reported that it successfully treated a 2-year-old boy with cerebral palsy using intravenous stem cells from his umbilical cord more than four years after he emerged from cardiac arrest paralyzed and in a coma. Also this spring, doctors in Illinois performed a windpipe transplant on a 2-year-old girl using lungs grown from her own stem cells; scientists used stem cells to regenerate teeth and damaged liver tissue in mice; and researchers in Ireland completed a preclinical trial using stem cells to heal diabetic foot ulcers, which leads to amputation in nearly half of middle-aged patients.

Since the late 1990s, doctors at AUH, the Makassed Medical Center, and other major health care facilities across the country have routinely used stem cells from the bone marrow of patients and donors to treat blood diseases such as leukemia.

They have also ventured into more experimental regenerative therapies for liver cirrhosis, cardiac infarctions, infertility, spinal cord injuries and even multiple sclerosis, with varying degrees of success.

Cosmetic surgeons in Lebanon regularly use adult stem cells from fatty tissue to augment breasts, buttocks and lips, stimulate hair growth, and remove stretch marks, burns and under-eye circles. Most hospitals also charge a fee to extract stem cells from the umbilical blood of newborns with the mothers consent.

But until the countrys first long-term cell bank, Transmedical For Life, opened in 2009, the samples had to be shipped to banks in Europe, which dramatically reduced the volume of viable cells. The facility also does not extract stem cells or perform transplantations on site, and only served Lebanese patients.

Although regenerative medicineis becoming increasingly routine in Lebanon, none of the stem cell procedures and services were conducted in a single facility, and the national contribution to scientific research on stem cells has lagged far behind that of the West and even the Gulf.

All this may change on Aug. 1 when the first comprehensive stem cell therapy center and bank, Reviva, opens at the Middle East Institute of Health in Bsalim, Metn.

According to Revivas scientific director, Dr. Norman Makdissi, Reviva will be the only medical facility in the Middle East equipped to collect, process, preserve and transplant stem cells from four different tissue sources in patients from Lebanon and abroad.

The 30 Lebanese investors, doctors and scientists behind the new $7 million clinic hope Reviva will become a leading international stem cell research institute and treatment facility, enhancing Lebanons status as a top medical tourism destination in the region.

When we talk about stem cells we are talking about cases where hope doesnt exist, Makdissi told the Daily Star. The number of stem cells is very limited in the organism so the future of the [field of regenerative] medicine will be about amplifying the number of stem cells to treat the patients with.

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Stem cell center to open next month