Repurposing a transplant drug for bone growth

The transplant immunosuppressant drug FK506, also known as tacrolimus or Prograf, can stimulate bone formation in both cell culture and animal Read more

Beyond the amyloid hypothesis: proteins that indicate cognitive stability

If you’re wondering where Alzheimer’s research might be headed after the latest large-scale failure of a clinical trial based on the “amyloid hypothesis,” check this Read more

Mother's milk is OK, even for the in-between babies

“Stop feeding him milk right away – just to be safe” was not what a new mother wanted to hear. The call came several days after Tamara Caspary gave birth to fraternal twins, a boy and a girl. She and husband David Katz were in the period of wonder and panic, both recovering and figuring out how to care for them. “A nurse called to ask how my son was doing,” says Caspary, a developmental Read more

Hinh Ly

A family of troublemakers known as XMRV

A long-delayed paper on the connection between chronic fatigue syndrome and XMRV (xenotropic murine leukemia virus-related virus) finally surfaced last week in PNAS. Astute readers may recall that XMRV has also been linked to prostate cancer.

Detecting XMRV in prostate tissue. A variety of assays (neutralizing antibodies, polymerase chain reaction or fluorescence in situ hybridization) may be used to look for XMRV

The twist from last week’s paper is that the NIH/FDA team, led by Harvey Alter, didn’t find viruses all with the same sequence in chronic fatigue patients. Instead, they found a cluster of closely related, but different, viruses. While confusing, these results may explain why tests for the presence of the virus that are based on viral DNA sequences may have generated varying (and conflicting) results. An alternative assay based on antibodies, such as the one urologist John Petros and colleagues at Emory developed, may be useful because it casts a wider net.

Pathologist Hinh Ly has been diving into the XMRV field, with a recent paper in Journal of Virology describing what “gateway” (receptor) molecule the virus uses to sneak into cells and what kinds of cells in the prostate it can infect.

In a collaboration with Ila Singh at the University of Utah, antiviral drug expert Raymond Schinazi has found that a number of drugs active against HIV also stop XMRV. This offers some hope that if doctors can detect members of the XMRV family, and figure out what they’re up to, they might be able to combat the troublemakers as well.

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Congrats to the telomere/ribosome Nobelists

Congratulations to Elizabeth Blackburn, Carol Greider and Jack Szostak for the 2009 Nobel Prize in medicine. The award is for their work on telomeres, the protective caps on the ends of chromosomes that shorten with every cell division and need specialized enzymes to be replenished.

Greider, Blackburn and Szostak discovered telomerase, the enzyme that copies the ends of chromosomes using a special RNA template. Telomerase is turned off in most human cells, but cancer cells often must reactivate it so that they can keep dividing like crazy.

The discovery of telomerase has led to new leads for potential anticancer drugs. This is a good example of the impact basic research can have on medicine, since the prize-winners were not thinking about anticancer drugs in the 1980s when they were doing their work.

Telomeres are specialized protective structures at the ends of chromosomes

Telomeres are specialized protective structures at the ends of chromosomes

The telomere trio’s work relates to several lines of research at Emory.

Immunologist Cornelia Weyand and her colleagues have shown that the telomeres of T cells are abnormally shortened in patients with rheumatoid arthritis. In effect, their cells’ chromosomes are prematurely aged. This result provides some hints on how to treat autoimmune diseases.

If blood-forming stem cells can’t keep their telomeres in shape, they can’t continue to regenerate the blood. Pathologist Hinh Ly’s research has made a connection between genetic defects in telomere maintenance and bone marrow failure syndrome in human patients.

Geneticists Christa Martin and David Ledbetter have been probing the relationship between mutations or recombination in the regions of the chromosome adjacent to telomeres and developmental disorders such as autism and mental retardation.

The 2009 Nobel Prize in Chemistry, awarded to Venki Ramakrishnan, Tom Steitz and Ada Yonath, has an even stronger connection to Emory. Christine Dunham, part of a growing contingent of crystallographers here, worked on ribosome structure in Ramakrishnan’s lab at the MRC.

The ribosome is a machine that decodes mRNA and produces protein step by step

The ribosome is a machine that decodes mRNA and produces protein step by step

She is examining the molecular details of how antibiotics and viruses perturb ribosome function.

What the two Nobels have in common is that they both honor work on molecular machines containing RNA, connections to the ancient, shadowy “RNA world“.

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