Genetics & Molecular Biology

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. 

Scientists have identified four new genes associated with a severe food allergy called eosinophilic esophagitis (EoE), which has only recently been recognized as a distinct condition. Its hallmark is inflammation and painful swelling in the esophagus, along with high levels of immune cells called eosinophils. It can affect people of any age, but is more common among young men who have a history of other allergic diseases such as asthma and eczema. 

 Everyone inherits two copies of most genes, one copy from each parent. In a recent study, researchers found in a rare mutation, people with one inactive copy of the gene NPC1L1 appeared to be protected against high LDL cholesterol, commonly called the "bad" cholesterol, and coronary heart disease, a narrowing of the heart's arteries that can lead to heart attacks. 

This mutation meant a 50 percent reduction in the risk of heart attack, at least epidemiologically, according to the paper
in The New England Journal of Medicine. NPC1L1 is of interest because it is the target of the drug ezetimibe, often prescribed to lower cholesterol.