How to ‘Time Jump’ Skin Cells

Research from the Babraham Institute has developed a method to “time jump” human skin cells by 30 years, turning back the aging clock for cells without losing their specialized function. Work by researchers in the Institute’s Epigenetics research program has been able to partly restore the function of older cells, as well as rejuvenating the molecular measures of biological age. The research is published today in the journal eLife, and while this topic is still at an early stage of exploration, it could revolutionize regenerative medicine.

As we age, our cells‘ ability to function declines and the  accumulates marks of aging. Regenerative biology aims to repair or replace cells including old ones. One of the most important tools in regenerative biology is our ability to createinducedstem cells. The process is a result of several steps, each erasing some of the marks that make cells specialized. In theory, these stem cells have the potential to become any cell type, but scientists aren’t yet able to reliably recreate the conditions to re-differentiate stem cells into all cell types.

The new method, based on the Nobel Prize-winning technique scientists use to make stem cells, overcomes the problem of entirely erasing cell identity by halting reprogramming part of the way through the process. This allowed researchers to find the precise balance between reprogramming cells, making them biologically younger, while still being able to regain their specialized cell function.

In 2007, Shinya Yamanaka was the first scientist to turn normal cells, which have a specific function, into  which have the special ability to develop into any cell type. The full process of stem cell reprogramming takes around 50 days using four key molecules called the Yamanaka factors. The new method, called “maturation phase transient reprogramming,” exposes cells to Yamanaka factors for just 13 days. At this point, age-related changes are removed and the cells have temporarily lost their identity. The partly reprogrammed cells were given time to grow under normal conditions, to observe whether their specific skin cell function returned. Genome analysis showed that cells had regained markers characteristic of  (fibroblasts), and this was confirmed by observing collagen production in the reprogrammed cells.

Young fibroblasts in the first image, the two are after 10 days, on the right with treatment, the last two are after 13 days, right with treatment. Red shows collagen production which has been restored

To show that the cells had been rejuvenated, the researchers looked for changes in the hallmarks of aging. As explained by Dr. Diljeet Gill, a postdoc in Wolf Reik’s lab at the Institute who conducted the work as a Ph.D. student, “Our understanding of aging on a molecular level has progressed over the last decade, giving rise to techniques that allow researchers to measure age-related biological changes in human cells. We were able to apply this to our experiment to determine the extent of reprogramming our new method achieved.”

Source: https://phys.org/

CRISPR Can Now Edit Multiple Genes At Once

Researchers at ETH Zurich have refined the famous CRISPR-Cas method. Now, for the very first time, it is possible to modify dozens, if not hundreds, of genes in a cell simultaneously.

Everyone’s talking about CRISPR-Cas. This biotechnological method offers a relatively quick and easy way to manipulate single genes in cells, meaning they can be precisely deleted, replaced or modified. Furthermore, in recent years, researchers have also been using technologies based on CRISPR-Cas to systematically increase or decrease the activity of individual genes. The corresponding methods have become the worldwide standard within a very short time, both in basic biological research and in applied fields such as plant breeding.

To date, for the most part, researchers could modify only one gene at a time using the method. On occasion, they managed two or three in one go; in one particular case, they were able to edit seven genes simultaneously. Now, Professor Randall Platt and his team at the Department of Biosystems Science and Engineering at ETH Zurich in Basel have developed a process that – as they demonstrated in experiments – can modify 25 target sites within genes in a cell at once. As if that were not enough, this number can be increased still further, to dozens or even hundreds of genes, as Platt points out. At any rate, the method offers enormous potential for biomedical research and biotechnology. “Thanks to this new tool, we and other scientists can now achieve what we could only dream of doing in the past.

Genes and proteins in cells interact in many different ways. The resulting networks comprising dozens of genes ensure an organism’s cellular diversity. For example, they are responsible for differentiating progenitor cells to neuronal cells and immune cells. “Our method enables us, for the first time, to systematically modify entire gene networks in a single step,” Platt says.

Moreover, it paves the way for complex, large-scale cell programming. It can be used to increase the activity of certain genes, while reducing that of others. The timing of this change in activity can also be precisely controlled.

This is of interest for basic research, for example in investigating why various types of cells behave differently or for the study of complex genetic disorders. It will also prove useful for cell replacement therapy, which involves replacing damaged with healthy cells. In this case, researchers can use the method to convert stem cells into differentiated cells, such as neuronal cells or insulin-producing beta cells, or vice versa, to produce stem cells from differentiated skin cells.

Source: https://www.ethz.ch