They still dont have a personality, and theyre waiting for the maturity call. Stem cells in our bone marrow usually develop into blood cells, replenishing our blood system. However, in states of emergency, the destiny of some of these stem cells may change: They can become virtually any type of cell – liver cells, muscle cells, nerve cells – responding to the bodys needs.
Prof. Tsvee Lapidot and Dr. Orit Kollet of the Weizmann Institutes Immunology Department have found how the liver, when damaged, sends a cry for help to these stem cells. "When the liver becomes damaged, it signals to stem cells in the bone marrow, which rush to it and help in its repair – as liver cells," says Lapidot. His research team has found that certain molecules that govern normal development of the liver become overproduced when it is damaged, signaling to the stem cells in the bone marrow to come to the site. The scientists were able to pinpoint the signaling molecules – HGF, MMP-9 and SDF-1– and describe the homing process. HGF is involved in liver cell development and, in irregular cases, can play a role in cancer metastasis. MMP-9 assists cell migration from the blood system into various types of tissue, including liver tissue. SDF-1 is a molecule that stem cells are attracted to. The scientists discovered that large amounts of HGF and MMP-9, when overproduced in the damaged liver, enter the blood flow and increase the sensitivity of stem cells in the bone marrow to SDF-1. Suddenly able to sense SDF-1s calling signal from the liver (which itself is amplified due to increased production and distribution of SDF-1), the stem cells migrate from the bone marrow into the blood and navigate their way to the liver. The findings could lead to new insights into organ repair and transplants, especially liver-related ones. They may also uncover a whole new stock of stem cells that can under certain conditions become liver cells. Until a few years ago only embryonic stem cells were thought to possess such capabilities. Understanding how stem cells in the bone marrow turn into liver cells could one day be a great boon to liver repair as well as an alternative to the use of embryonic stem cells.
Alex Smith | EurekAlert!
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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.
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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.
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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!
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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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