Memories of the way they used to be

September 18, 2009
Memories of the way they used to be

Enlarge

This is a mosaic of human iPS cells generated by "footprint-free" technology expressing the pluripotent marker Oct4. Credit: University of California, San Diego School of Medicine

A team of researchers from the University of California, San Diego School of Medicine and the Salk Institute for Biological Studies in La Jolla have developed a safe strategy for reprogramming cells to a pluripotent state without use of viral vectors or genomic insertions. Their studies reveal that these induced pluripotent stem cells (iPSCs) are very similar to human embryonic stem cells, yet maintain a "transcriptional signature." In essence, these cells retain some memory of the donor cells they once were.

The study, led by UCSD Stem Cell Program researcher Alysson R. Muotri, assistant professor in the Departments of Pediatrics at UCSD and Rady Children's Hospital and UCSD's Department of Cellular and Molecular Medicine, will be published online in on September 17.

"Working with neural , we discovered that a single factor can be used to re-program a human cell into a pluripotent state, one with the ability to differentiate into any type of cell in the body" said Muotri. Traditionally, a combination of four factors was used to create iPSCs, in a technology using viral vectors - viruses with the potential to affect the transcriptional profile of cells, sometimes inducing or tumors.

In addition, while both mouse and human iPSCs have been shown to be similar to embryonic stem cells in terms of , and their potential to differentiate into different types of cells, researchers had not achieved a comprehensive analysis to compare iPSCs and embryonic stem cells.

"One reason is that previous methodologies used to derive iPSCs weren't 'footprint free,'" Muotri explained. "Viruses could integrate into the genome of the cell, possibly affecting or disrupting genes."

"In order to take full advantage of reprogramming, it is essential to develop methods to induce pluripotency in the absence of permanent changes in the genome," added Fred H. Gage, PhD, a professor in the Laboratory for Genetics at the Salk Institute and the Vi and John Adler Chair for Research on Age-Related Neurodegenerative Diseases.

By creating iPSCs from human without the use of viruses, the scientists learned something new. While the genetic transcriptional profile of the new iPSCs was closer to that of than to human neural stem cells, the iPSCs still carried a transcriptional "signature" of the original neural cell.

"While most of the original genetic memory was erased when the cells were reprogrammed, some were retained," said Muotri. He added that, in the past, it wasn't known if this was caused by the use of viral vectors. "By using a footprint-free methodology, we have shown a safe way to generate human iPSCs for clinical purposes and basic research. We've also raised an interesting question about what, if any, effect the 'memory retention' of these cells might have."

Source: University of California - San Diego (news : web)

4.3 /5 (7 votes)  

Filter


Move the slider to adjust rank threshold, so that you can hide some of the comments.


Display comments: newest first

danman5000
Sep 18, 2009

Rank: not rated yet
Hm anyone else notice how the picture for this article about memory looks just like Simon? Coincidence? :-o
Sean_W
Sep 18, 2009

Rank: not rated yet
Hm anyone else notice how the picture for this article about memory looks just like Simon? Coincidence? :-o


Well Simon is supposed to improve memory. Maybe that's how stem cells do it.
Rank 4.3 /5 (7 votes)
Relevant PhysicsForums posts
  • Factors affecting beet root cell membrane
    created9 hours ago
  • Stem cell question.
    createdFeb 10, 2012
  • Protease cleavage
    createdFeb 10, 2012
  • Pertubance in a model
    createdFeb 10, 2012
  • Cancer drugs and Alzheimer's, Oh my!
    createdFeb 09, 2012
  • Squishing cells
    createdFeb 09, 2012
  • More from Physics Forums - Biology

More news stories

A mitosis mystery solved: How chromosomes align perfectly in a dividing cell

Although the process of mitotic cell division has been studied intensely for more than 50 years, Whitehead Institute researchers have only now solved the mystery of how cells correctly align their chromosomes during symmetric ...

Biology / Cell & Microbiology

created 5 hours ago | popularity 4.5 / 5 (8) | comments 0 | with audio podcast

Researchers find extensive RNA editing in human transcriptome

In a new study published online in Nature Biotechnology, researchers from BGI, the world's largest genomics organization, reported the evidence of extensive RNA editing in a human cell line by analysis of RNA-seq data, demons ...

Biology / Biotechnology

created 5 hours ago | popularity 5 / 5 (4) | comments 0 | with audio podcast

The proteins ensuring genome protection

Researchers from the University of Geneva (UNIGE), Switzerland, have discovered the crucial role of two proteins in developing a cell 'anti-enzyme shield'. This protection system, which operates at the level of molecular ...

Biology / Cell & Microbiology

created 5 hours ago | popularity 5 / 5 (3) | comments 0 | with audio podcast

Entire genome of extinct human decoded from fossil

(PhysOrg.com) -- In 2010, Svante Pääbo and his colleagues presented a draft version of the genome from a small fragment of a human finger bone discovered in Denisova Cave in southern Siberia. The ...

Biology / Biotechnology

created Feb 07, 2012 | popularity 4.7 / 5 (59) | comments 48 | with audio podcast

Why are there so few fish in the Earth's oceans?

(PhysOrg.com) -- A Stony Brook University researcher has found that, contrary to popular belief, there are not plenty of fish in the sea.

Biology / Plants & Animals

created Feb 08, 2012 | popularity 4.2 / 5 (18) | comments 27 | with audio podcast


Declining health-care productivity in England: Who says so?

Reports that the National Health Service in England has been declining in productivity in the last decade appear to have been accepted as fact. However, a Viewpoint published Online First by The Lancet disputes this. The Vi ...

Scientists discover molecular secrets of 2,000-year-old Chinese herbal remedy

For roughly two thousand years, Chinese herbalists have treated Malaria using a root extract, commonly known as Chang Shan, from a type of hydrangea that grows in Tibet and Nepal. More recent studies suggest that halofuginone, ...

New method to examine batteries -- MRI from the inside

There is an ever-increasing need for advanced batteries for portable electronics, such as phones, cameras, and music players, but also to power electric vehicles and to facilitate the distribution and storage of energy derived ...

Overeating may double risk of memory loss

New research suggests that consuming between 2,100 and 6,000 calories per day may double the risk of memory loss, or mild cognitive impairment (MCI), among people age 70 and older. The study was released today and will be ...

Lab study raises questions over nano-particle impact

Tests involving chickens have raised questions about the impact on health from engineered nano-particles, the ultra-fine grains commonly used in drugs and processed foods, scientists said on Sunday.

Starve a virus, feed a cure? Findings show how some cells protect themselves against HIV

A protein that protects some of our immune cells from the most common and virulent form of HIV works by starving the virus of the molecular building blocks that it needs to replicate, according to research published online ...