Stories tagged cells


Aging in reverse gracefully: Scientists are successfully changing old lab mice into young ones.
Aging in reverse gracefully: Scientists are successfully changing old lab mice into young ones.Courtesy Andreas-photography
Bob Dylan first sang about it in the chorus of his 1964 song "My Back Pages" when he wrote ""Ah, but I was so much older then/I'm younger than that now"." He reinforced the notion ten years later when he released "Forever Young" in 1974.

It's all about staying young and not growing old - not ageism mind you - but anti-aging.

In a study appearing in a recent issue of the journal Cell, researchers have successfully reversed the aging process by turning a 2 year-old into one that resembles one that's a mere 6 months old. In human terms this would be equivalent to turning a 60 year-old back into a 20 year-old.

Dr. David Sinclair, professor of genetics at Harvard Medical School, and his team of researchers injected aging mice for a week with a compound known as nicotinamide adenine dinucleotide (NAD+), a natural chemical made from young cells. As mammalian cells age, NAD+ production drops by half causing mitochondrial dysfunction, and the processing of oxygen to fall off. Cells then become vulnerable to the various ailments that aging attracts. But in the treated older mice the cells began to take on the vitality and appearance of young mice.

Sinclair will next try administering NAD+via the drinking water used by lab mice to see how things go . If it has the same effect on the mice's cells, someone call Ponce de Leon because we could be talking about an actual Fountain of Youth!

Since NAD+ is a naturally produced compound, the concern for harmful after-effects is slight. Human trials could begin as early as next year - but it's not going to be cheap - somewhere in the neighborhood of $50,000 a day!

If I win the lottery in the next few months, I'll be first in line to become 20 years-old again, but only if I can retain my experience and any wisdom I may have acquired along the way. But if not, I guess I'll just start humming Dylan's "Knocking on Heaven's Door."

Time magazine story
Guardian story
BBC Health News


Doubling up the double helix: The newly discovered quadruple helix in human DNA could lead to new treatments in cancer.
Doubling up the double helix: The newly discovered quadruple helix in human DNA could lead to new treatments in cancer.Courtesy rijksbandradio (original image) via Flckr; graphic by author.
By now most readers are aware of the double helix, the two intertwined ribbons of genetic information that make up our DNA.

Now researchers at University of Cambridge have announced the discovery of a quadruple helix in the human genome. The four-stranded genetic ribbons are termed G-quadruplexes because they contain high levels of the nucleotide guanine (the other 3 nucleotides are adenine, thymine, and cytosine – together they make up the G, A, T, and C elements of DNA; uracil (U) replaces thymine in RNA). G-quadruplexes mainly appear at the moment of cell replication, when cells divide and multiply. Researchers think this indicates that G-quadruplexes are an essential part of the replication process. The upsurge of G-quadrupleexes was detected using fluorescent biomarkers. The discovery could open up new avenues in the treatment of cancer

"The research indicates that quadruplexes are more likely to occur in genes of cells that are rapidly dividing, such as cancer cells,” said Shankar Balasubramanian, the study’s lead researcher. “For us, it strongly supports a new paradigm to be investigated -- using these four-stranded structures as targets for personalised treatments in the future."

Balasubramanian, a professor at the Department of Chemistry and Cambridge Research Institute, thinks synthetic molecules could one day be used to corral the G-quadruplexes and hinder the out-of-control cell division often prevalent in cancerous cells. In fact, the research team has already been successful in slowing down the replication process by using such molecules. During their experiments, when cell division was blocked, the number of G-quadruplexes decreased.

The research was published in Nature Chemistry. The 'quadruple helix' discovery comes 60 years after the discovery of the double helix in 1953, also at the University of Cambridge.

Science Daily

You know what's cool? Animation. And folks with the same skills used to bring you Red Dead Redemption and Toy Story 3 are also hard at work creating scientific visualizations that show the machinery of life.
It's Friday, so it's time for a new Science Friday video. Science Friday
Science Friday
Courtesy Science Friday
"Reporting in the journal Science, Paul Kubes and colleagues filmed immune cells called neutrophils finding their way to a mouse's wounded liver. The researchers wanted to understand how neutrophils find injuries when bacteria aren't around to signal the damage."

Human embryonic stem cell differentiation: A: Cell colonies that are not yet differentiated. B: Nerve cell
Human embryonic stem cell differentiation: A: Cell colonies that are not yet differentiated. B: Nerve cellCourtesy Nissim Benvenisty

Another step toward living forever

Stem cells have the potential to become almost any type of body part. I believe they will soon be used to rejuvenate, repair, or rebuild body parts. Look at our past Science Buzz posts about stem cells. Bad knees or hips? Inject some stem cells to rebuild the cartilage. Stem cells also can repair cut spinal cords, damaged eyes, diseased brains, or help a diabetic's pancreas make insulin.

A new, better way to make stem cells

Up until now, the stem cells created by reprogramming adult skin cells still had bits and pieces remaining that were not safe enough for human applications.
"Now stem cell researcher Derrick Rossi of Harvard Medical School in Boston and his colleagues have developed a way to reprogram cells using synthetic RNA molecules." (Science Magazine) The technique is also twice as fast and 100% more efficient. The team calls its cells RiPS cells, for RNA induced Pluripotent Cells.

Learn more about RNA induced Pluripotent Cells

The new technique, is published online in the journal, Cell Stem Cell.


Henrietta Lacks (1920-1951): The Harvard Gazette is copyrighted, but no copyright for the image is specified by the magazine.
Henrietta Lacks (1920-1951): The Harvard Gazette is copyrighted, but no copyright for the image is specified by the magazine.Courtesy Harvard University Gazette

Henrietta Lacks 1950s Cells Still Alive, Helping Science

Even though Henrietta Lacks died in 1951, her cells are still alive.
By 1954, Henrietta Lacks' cells known as HeLa were used by Jonas Salk to develop a vaccine for polio.

"In the half-century since Henrietta Lacks' death, her ... cells ... have continually been used for research into cancer, AIDS, the effects of radiation and toxic substances, gene mapping, and countless other scientific pursuits".

The Immortal Life of Henrietta Lacks

"A new book by Rebecca Skloot, The Immortal Life of Henrietta Lacks, examines the extraordinary impact of HeLa on science and the effects of that unchosen legacy on Lacks’ family." Wired


SalamanderCourtesy USDA
Lets say you are walking in the woods and you see a 12 point deer ahead of you. You sneek up quietly but not quietly enough. The deer hears you looks right at you and begins to charge. Before you know it its right antler has sheered off your arm! What do you do? Well if you were a salamander you would simple re-grow it.

For centuries scientist have wondered how salamanders regenerate limbs. In recent history they believed the tissue around the injury regressed into pluripotent stem cells (the kind we have all heard about that can morph into many different types of cells) and they reform into each cell type needed to create the limb.

This research was conducted to help understand how the salamander was able to do this amazing feat so that we could apply it to humans. Unfortunately, stem cells are not the easiest thing to work with but, that is old news now.

New research has shown that the salamander's cells do not regress but have memory that allows them to grow into what they once were. The memory is so good that the cartilage from the lower limb re-grows in the lower limb again.

The way scientist were able to do this was by engineering a florescent protein in a group of salamanders and transplanted only a select cells (skin, bone, muscle, etc) into embryos. After the embryos had grown, a limb was amputated. When it re-grew scientists observed that the glowing cells were not spread out amongst all the different cell types, as it would be if the cells had regressed into blank slates, but the florescent protein was only found in the original transplanted cell type.

Good new for us humans. This new finding may, although most likely not in our life time, make it easier to regenerate human organs.

The cells of our bodies are constantly in motion. In fact, zap them with light and they vibrate, creating sound – much too faint to hear, but sensitive instruments can record the vibrations. Two biologists at the University of Manchester in England have found that healthy cells vibrate differently than cancerous cells. They are hoping to use this to develop new, less-invasive tests to diagnose cancer.


Human embryos using animal eggs

Embryo, 8 cells
Embryo, 8 cellsCourtesy Ekem
Last week we learned that scientists cloned human embryos using adult skin and fertile eggs from a woman donor. Now the Human Fertilization and Embryology Authority in Britain has approved creating human embryos using eggs from animals like cows or rabbits. Because the animal cell's nucleus would be removed before human DNA was added, scientists said the resulting egg would not be a chimera.

"Cow eggs seem to be every bit as good at doing this job as human eggs," said Lyle Armstrong of Newcastle University.
"We will only use them as a scientific tool and we need not worry about cells being derived from them ever being used to treat human diseases," Armstrong said.

Technique eliminates destruction of human eggs

Animal eggs are abundant and easily obtained. Researchers hope to refine their techniques by practicing first on animal eggs to producing human stem cells. Human stem cells, which have the ability to develop into any cell in the human body, show promise for understanding and healing many human ailments. The embryos would not be allowed to develop for more than two weeks.


Blastocyst day 5
Blastocyst day 5Courtesy Ekem

DNA from clone identical to that from adult skin donor

A paper published in the online journal, Stem Cells, yesterday titled "Development of Human cloned Blastocysts Following Somatic Cell Nuclear Transfer (SCNT) with Adult Fibroblasts" is the first documented demonstration that ordinary cells from an adult human can be used to make cloned embryos mature enough to produce stem cells

"A research team at Stemagen, a biotech company based in San Diego, California, started with skin cells donated by two men and 25 eggs, or oocytes, donated by women at a nearby fertility center. The scientists removed the DNA-containing nuclei from the eggs and replaced them with DNA from the donor skin cells. Two of the eggs became 5-day-old embryos, or blastocysts, that were clones of the male donors."Science

Why are we cloning humans?

The next big step will be to create a human embryonic stem cell line from cloned embryos. Stem cells from cloned embryos could provide a valuable tool for studying diseases, screening drugs, and creating transplant material to treat conditions like diabetes and Parkinson's disease.

Should we be doing this?

As expected, critics are raising objections. This procedure requires cutting healthy eggs out of women, then altering them to produce living embryos, which are then destroyed. Should this be allowed?

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