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Archive - Apr 30, 2013

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Two Types of Blood Vessel Stem Cells Identified—May Point to Disease Therapies

Many diseases – obesity, Type 2 diabetes, and muscular dystrophy, for example – are associated with fat accumulation in muscle. In essence, fat replacement causes the muscles to weaken and degenerate. Scientists at Wake Forest Baptist Medical Center have discovered the biological mechanism involved in this process, which could point the way to potential therapies. The findings were published online on April 27, 2013 in Stem Cells and Development. The Wake Forest Baptist researchers proved that pericytes, stem cells associated with blood vessels, contain two sub-types with completely different roles: Type 1, which form only fat cells, and Type 2, which form only muscle cells. "We found that Type 1 contributes to fat accumulation in the skeletal muscle under pathogenic conditions, while Type 2 helps in forming muscle," said Osvaldo Delbono, M.D., Ph.D., professor of internal medicine at Wake Forest Baptist and senior author of the study. "This is important because now we have the potential to develop therapies that can block the activity of Type 1 pericytes to form fat or activate Type 2 pericytes to regenerate muscle." In the study, the researchers were able to identify the subtypes through genetic and molecular labeling methods. Using an in vitro model, they showed that Type 1 pericytes form fat while Type 2 pericytes form muscle. To test their theory in an animal model, the scientists first injected Type 2 cells into injured muscle in healthy young mice to determine if the muscle would regenerate to repair the damage; it did. When Type 1 cells were injected, the mice did not form muscle.

Zebrafish Study Suggests Vitamin B2 May Be Antidote to Cyanide Poisoning

With the remains of a recent lottery winner having been exhumed for investigation of foul play related to cyanide poisoning, future winners might wonder what they can do to avoid the same fate. A new report in May 2013 issue of The FASEB Journal involving studies in zebrafish suggests that riboflavin, also known as vitamin B2, may mitigate the toxic effects of this infamous poison. In addition, the report shows that zebrafish are a viable model for investigating the effects of cyanide on humans. As with any research involving animal models, these findings are preliminary until thoroughly tested in clinical trials. Anyone who suspects cyanide poisoning should not attempt to use riboflavin as an antidote, and instead should contact local poison control centers or emergency health services immediately."We are encouraged to see that many of the effects of cyanide on zebrafish mirror the effects on humans," said Randall Peterson, Ph.D., the senior author of the study and a research at the Harvard Medical School. "Hopefully, the cyanide biomarkers and antidotes we discover with the help of zebrafish can one day improve our ability to diagnose and treat humans affected by cyanide poisoning." To make this discovery, scientists exposed zebrafish to cyanide and measured the effects on their behavior, heart rate, and survival. The chemical changes that occurred were measured using a mass spectrometer. The effects in zebrafish were then compared to the effects of cyanide on rabbits and humans. Many of the effects in zebrafish matched those seen in rabbits and humans, confirming that the zebrafish could be used as a model of human cyanide exposure.

How Does Early Pregnancy Reduce Breast Cancer Risk?

Being pregnant while young is known to protect women against breast cancer. But why? Research published online on April 29, 2013 in BioMed Central's open access journal Breast Cancer Research finds that Wnt/Notch signaling ratio is decreased in the breast tissue of mice that have given birth, compared to virgin mice of the same age. Early pregnancy is protective against breast cancer in humans and in rodents. In humans having a child before the age of 20 decreases risk of breast cancer by half. Using microarray analysis researchers from Basel discovered that genes involved in the immune system and differentiation were up-regulated after pregnancy, while the activity of genes coding for growth factors was reduced. The activity of one particular gene, Wnt4, was also down-regulated after pregnancy. The protein from this gene (Wnt4) is a feminizing protein - absence of this protein propels a fetus towards developing as a boy. Wnt and Notch are opposing components of a system which controls cellular fate within an organism and when the team looked at Notch they found that genes regulated by Notch were up-regulated, Notch-stimulating proteins were up-regulated, and Notch-inhibiting proteins were down-regulated. Wnt/Notch signaling ratio was permanently altered in the basal stem/progenitor cells of mammary tissue of mice by pregnancy. Dr. Mohamed Bentires-Alj from the Friedrich Miescher Institute for Biomedical Research, who led this study explained, "The down-regulation of Wnt is the opposite of that seen in many cancers, and this tightened control of Wnt/Notch after pregnancy may be preventing the runaway growth present in cancer." [Press release] [Breast Cancer Research article]

Zone in with Zon: Highlights of Molecular Medicine Tri-Conference 2013

Dr. Gerald Zon’s latest blog post in “Zone in with Zon—What’s Trending in Nucleic Acid Research,” (http://zon.trilinkbiotech.com/) was posted on April 28, 2013 and features Dr. Zon’s key takeaways from the Molecular Medicine Tri-Conference 2013 held in February in San Francisco. Among the conference highlights for Dr. Zon were the “democratization” of diagnostics, the clinical impact of next-generation sequencing, and the emerging use of smartphone technology in point-of-care diagnostics. Dr. Zon is an eminent nucleic acid chemist and Director of Business Development at TriLink BioTechnologies in San Diego, California. [Zon blog post]