Genetics & Molecular Biology

There is a running joke in America that there are three times as many people in the U.S. claiming to be Irish as there are actual people in Ireland. 

Though it's nice to claim to be Irish because of a last name, America is a melting pot. And it is so melted that the genetic ancestry of racial and ethnic groups varies significantly even across different geographic regions in the United States. A paper in the American Journal of Human Genetics, researchers analyzed the genomes of more than 160,000 African-Americans, Latin-Americans and European-Americans, providing insights into the subtle differences in genetic ancestry across the United States. 

A new paper has found that inhibiting or blocking stem cells ability to make a specific decision, leads to better cell growth and could lead to defined ways to differentiate stem cells.

Th authors say their research is the first comprehensive analysis of a pathway important for stem and cancer cell decisions known as Erk. As a result, they hope the work could contain clues to cancer treatment as well as helping to establish a platform to make stem cell treatments for gut related disorders like the pancreas or the liver. 

Hydrogen peroxide (H2O2) is a strong oxidizer. You may know it as a wound disinfectant or as a bleaching agent for hair and teeth but it is also created naturally in our bodies, as part of our cellular oxidation.

H2O2 belongs to a group of natural chemicals called reactive oxygen species (ROS) and when the process gets out of hand, too much oxidation can have a damaging effect on cells and their components. Unchecked free radicals, the most well-known ROS, are believed to play a role in carcinogenesis, degenerative diseases, and even aging. To prevent that, our cells also contain antioxidant enzymes known as peroxiredoxins that degrade H2O2 molecules. We don't want to have no H202, despite the chemophobia of environmental and food activists, we want just enough.

Diseases of dysfunctional mitochondria, also known as mitochondrial diseases, have a prevalence of  up to 1 in 2,000 people and predominantly affect children, though adult-onset disorders are also recognized. An international collaboration has discovered that mutations in the GTPBP3 gene cause defects in protein synthesis in mitochondria and are associated with a devastating disease.

Mitochondria are compartments present in every cell of the body except red blood cells and are responsible for generating almost all of the energy needed by the body to sustain life and to grow. In mitochondria, energy is produced by a large number of proteins, which are manufactured according to a blueprint, the cell’s DNA. 
As a consumer and as an agricultural scientist, I’m looking forward to the introduction of the Arctic® apple. It is possibly nearing approval by regulators in the US and Canada which could mean that supplies might finally be available in a few more years.

These apples could give consumers the possibility of buying apples that maintain their flavor, appearance and vitamin content after cutting, and which can also be used to make beautiful dried apple slices without the need for sulfites (something that can be a problem for some people).

Two compounds appear to block the cardiac damage caused by the chemotherapy drug doxorubicin, according to a report in Science Translational Medicine which indicates that inhibiting the action of the enzyme MDH2, which is key to the generation of cellular energy in mitochondria, could prevent doxorubicin-induced damage to cardiac cells without reducing the drug's anti-tumor effects. 

The discovery of the mechanism that enables the enzyme Lecithin: retinol acyltransferase (LRAT) to store vitamin A, a process that is indispensable for vision, may provide a boost for designing small molecule therapies for degenerative eye diseases.

The same enzymatic activity of LRAT that allows specific cells to absorb vitamin A can be used to transport small molecule drugs to the eye. These drugs would accumulate in eye tissue, lowering the effective dose and reducing risk of systemic side effects. 

When a large protein unfolds in a cell, it slows down and can get stuck in traffic. University of Illinois chemists now can watch the way the unfolded protein diffuses, which could provide great insight into protein-misfolding diseases such as Alzheimer's and Huntington's.

Researchers have hypothesized that an unfolded protein moves more slowly through the cell, because it would be a big, stringy mess rather than a tightly wrapped package. The team devised a way to measure how diffusion slows down when a protein unfolds using a fluorescence microscope, then used three-dimensional diffusion models to connect the protein's unfolding to its motion. 

Macrophages sweep up cellular debris and pathogens in order to thwart infection - sometimes even before the white blood cells, which are designed for that task. 

Neutrophils, white blood cells, are "first responders" that are attracted to wounds by signaling molecules called reactive oxygen species (ROS) that activate a protein kinase. When neutrophils finish their work, inflammation is partly resolved through apoptosis, or cell suicide, and then macrophages arrive to clean up the infection.

But neutrophils can also elect to leave wounded tissue in a process known as reverse migration. Whether macrophages promote this mode of inflammation resolution is unclear. 

Alzheimer's disease progresses inside the brain as deposits of the toxic protein amyloid-beta (Aβ),overwhelm neurons. A side effect of accumulating Aβ in neurons is the fragmentation of the Golgi apparatus, the part of the cell involved in packaging and sorting protein cargo including the precursor of Aβ. Or it may be the other way around and loss of Golgi function is a driving force behind Alzheimer's.

Yanzhuang Wang, Gunjan Joshi, and colleagues at the University of Michigan, Ann Arbor, set out to uncover the mechanism damaging the Golgi using a transgenic mouse and tissue culture models of 
Alzheimer's disease
to look at what was going on.