The researchers found that mice engineered without the Akt1 gene and fed a high cholesterol diet had many more signs of aortic atherosclerosis compared to their littermates. And, surprisingly, their coronary lesions were similar to humans, say the scientists.
“About 20 percent of the mice died spontaneously, perhaps due to an acute heart attack,” said William Sessa, senior author of the study, professor of pharmacology, and director of Yale’s vascular biology and therapeutics program.
Atherosclerosis is a chronic inflammatory response in arterial walls, in large part due to deposits of lipoproteins—which are plasma proteins that carry cholesterol and triglycerides. The "hardening" or "furring" of the arteries is caused by plaque formation.
In the vascular wall, Akt plays an important role in regulating the development of endothelial cells, which line the entire circulatory system, from the heart to the smallest capillary. Endothelial cells play an important role in regulating blood pressure, in blood clotting, in plaque formation in the arteries, and in formation of new blood vessels.
“The major finding of this study is that an absence of Akt1 aggravates atherosclerotic lesions, promotes coronary atherosclerosis, and may be a model of acute coronary syndromes,” Sessa said. “Specific activation of Akt1 may provide a therapeutic approach to decrease formation of lesions in the arterial wall and promote plaque stabilization to prevent an acute heart attack.”
One concern, he said, is that specific drugs are being developed to inhibit Akt in cancer patients to reduce progression of tumors, and that these drugs may also promote hardening of the arteries.
Jacqueline Weaver | EurekAlert!
Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden
The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
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