News Article | April 26, 2017
Using Venezia™, physicians at Ludwig-Maximilians University of Munich (LMU Munich) successfully performed the interstitial brachytherapy procedure. Venezia allows clinicians to treat advanced stages of cervical cancer, such as stages IIIA and IIIB with vaginal and parametrial extensions, which previously required very specialized techniques, such as freehand needle placement. "Getting the radiation to reach to disease extensions beyond the cervix has always been challenging with conventional brachytherapy applicators," says Stefanie Corradini, MD, radiation oncologist at LMU Munich. "Venezia incorporates components that enable us to treat the cervix as well as the parametrium and vagina using a single applicator. We were able to treat this first patient's disease extension in these anatomies by placing both parallel and oblique interstitial needles. With Venezia, we will have a very standardized way to treat cervical cancer and interstitial needle placement will be very reproducible." "The design of Venezia makes it intuitive to use," adds LMU Munich's Cornelius Maihöfer, MD. "Within just a few trial runs of applicator assembly, the team became proficient in handling Venezia." The two lunar-shaped ovoids of Venezia form a ring that when clicked together provide the ease of insertion of a tandem and ovoid applicator in combination with the dose distribution provided by a ring applicator. The ring creates a pear-shaped dose distribution, a proven dosimetry shape that matches the cervix and endometrium. To reach tumor extension beyond the cervix, the design also incorporates a perineal template for placement of parallel needles and holes in the ring for insertion of oblique needles. "You could view Venezia as a hybrid brachytherapy applicator that combines the best characteristics of both ring and ovoid devices as well as an array of interstitial catheters that can be customized to each patient´s tumor anatomy," Dr. Corradini says. For further information, please contact: This information was brought to you by Cision http://news.cision.com The following files are available for download:
News Article | May 10, 2017
No more error-prone evaporation deposition, drop casting or printing: Scientists at LMU Munich and FSU Jena have developed organic semiconductor nanosheets, which can easily be removed from a growth substrate and placed on other substrates. München, 10-May-2017 — /EuropaWire/ — Today’s computer processors are composed of billions of transistors. These electronic components normally consist of semiconductor material, insulator, substrate, and electrode. A dream of many scientists is to have each of these elements available as transferable sheets, which would allow them to design new electronic devices simply by stacking. This has now become a reality for the organic semiconductor material pentacene: Dr. Bert Nickel, a physicist at LMU Munich, and Professor Andrey Turchanin (Friedrich Schiller University Jena), together with their teams, have, for the first time, managed to create mechanically stable pentacene nanosheets. The researchers describe their method in the journal Advanced Materials. They first cover a small silicon wafer with a thin layer of a water-soluble organic film and deposit pentacene molecules upon it until a layer roughly 50 nanometers thick has formed. The next step is crucial: by irradiation with low-energy electrons, the topmost three to four levels of pentacene molecular layers are crosslinked, forming a “skin” that is only about five nanometers thick. This crosslinked layer stabilizes the entire pentacene film so well that it can be removed as a sheet from a silicon wafer in water and transferred to another surface using ordinary tweezers. Apart from the ability to transfer them, the new semiconductor nanosheets have other advantages. The new method does not require any potentially interfering solvents, for example. In addition, after deposition, the nanosheet sticks firmly to the electrical contacts by van der Waals forces, resulting in a low contact resistance of the final electronic devices. Last but not least, organic semiconductor nanosheets can now be deposited onto significantly more technologically relevant substrates than hitherto. Of particular interest is the extremely high mechanical stability of the newly developed pentacene nanosheets, which enables them to be applied as free-standing nanomembranes to perforated substrates with dimensions of tens of micrometers. That is equivalent to spanning a 25-meter pool with plastic wrap. “These virtually freely suspended semiconductors have great potential,” explains Nickel. “They can be accessed from two sides and could be connected through an electrolyte, which would make them ideal as biosensors, for example”. “Another promising application is their implementation in flexible electronics for manufacturing of devices for vital data acquisition or production of displays and solar cells,” Turchanin says. Advanced Materials 2017
News Article | May 8, 2017
Today’s computer processors are composed of billions of transistors. These electronic components normally consist of semiconductor material, insulator, substrate, and electrode. A dream of many scientists is to have each of these elements available as transferable sheets, which would allow them to design new electronic devices simply by stacking. This has now become a reality for the organic semiconductor material pentacene: Dr. Bert Nickel, a physicist at LMU Munich, and Professor Andrey Turchanin (Friedrich Schiller University Jena), together with their teams, have, for the first time, managed to create mechanically stable pentacene nanosheets. The researchers describe their method in the journal Advanced Materials. They first cover a small silicon wafer with a thin layer of a water-soluble organic film and deposit pentacene molecules upon it until a layer roughly 50 nanometers thick has formed. The next step is crucial: by irradiation with low-energy electrons, the topmost three to four levels of pentacene molecular layers are crosslinked, forming a “skin” that is only about five nanometers thick. This crosslinked layer stabilizes the entire pentacene film so well that it can be removed as a sheet from a silicon wafer in water and transferred to another surface using ordinary tweezers. Apart from the ability to transfer them, the new semiconductor nanosheets have other advantages. The new method does not require any potentially interfering solvents, for example. In addition, after deposition, the nanosheet sticks firmly to the electrical contacts by van der Waals forces, resulting in a low contact resistance of the final electronic devices. Last but not least, organic semiconductor nanosheets can now be deposited onto significantly more technologically relevant substrates than hitherto. Of particular interest is the extremely high mechanical stability of the newly developed pentacene nanosheets, which enables them to be applied as free-standing nanomembranes to perforated substrates with dimensions of tens of micrometers. That is equivalent to spanning a 25-meter pool with plastic wrap. “These virtually freely suspended semiconductors have great potential,” explains Nickel. “They can be accessed from two sides and could be connected through an electrolyte, which would make them ideal as biosensors, for example.” “Another promising application is their implementation in flexible electronics for manufacturing of devices for vital data acquisition or production of displays and solar cells,” Turchanin says.
News Article | May 25, 2017
An international team of physicists has monitored the scattering behavior of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy. We can refer to electrons in non-conducting materials as 'sluggish'. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence relatively still in a dielectric crystal lattice. This idyll has now been heavily shaken up by a team of physicists led by Matthias Kling, the leader of the Ultrafast Nanophotonics group in the Department of Physics at Ludwig-Maximilians-Universitaet (LMU) in Munich, and various research institutions, including the Max Planck Institute of Quantum Optics (MPQ), the Institute of Photonics and Nanotechnologies (IFN-CNR) in Milan, the Institute of Physics at the University of Rostock, the Max Born Institute (MBI), the Center for Free-Electron Laser Science (CFEL) and the University of Hamburg. For the first time, these researchers managed to directly observe the interaction of light and electrons in a dielectric, a non-conducting material, on timescales of attoseconds (billionths of a billionth of a second). The study was published in the latest issue of the journal Nature Physics. The scientists beamed light flashes lasting only a few hundred attoseconds onto 50 nanometer thick glass particles, which released electrons inside the material. Simultaneously, they irradiated the glass particles with an intense light field, which interacted with the electrons for a few femtoseconds (millionths of a billionth of a second), causing them to oscillate. This resulted, generally, in two different reactions by the electrons. First, they started to move, then collided with atoms within the particle, either elastically or inelastically. Because of the dense crystal lattice, the electrons could move freely between each of the interactions for only a few ångstrom (10-10 meter). "Analogous to billiard, the energy of electrons is conserved in an elastic collision, while their direction can change. For inelastic collisions, atoms are excited and part of the kinetic energy is lost. In our experiments, this energy loss leads to a depletion of the electron signal that we can measure," explains Professor Francesca Calegari (CNR-IFN Milan and CFEL/University of Hamburg). Since chance decides whether a collision occurs elastically or inelastically, with time inelastic collisions will eventually take place, reducing the number of electrons that scattered only elastically. Employing precise measurements of the electrons' oscillations within the intense light field, the researchers managed to find out that it takes about 150 attoseconds on average until elastically colliding electrons leave the nanoparticle. "Based on our newly developed theoretical model we could extract an inelastic collision time of 370 attoseconds from the measured time delay. This enabled us to clock this process for the first time," describes Professor Thomas Fennel from the University of Rostock and Berlin's Max Born Institute in his analysis of the data. The researchers' findings could benefit medical applications. With these worldwide first ultrafast measurements of electron motions inside non-conducting materials, they have obtained important insight into the interaction of radiation with matter, which shares similarities with human tissue. The energy of released electrons is controlled with the incident light, such that the process can be investigated for a broad range of energies and for various dielectrics. "Every interaction of high-energy radiation with tissue results in the generation of electrons. These in turn transfer their energy via inelastic collisions onto atoms and molecules of the tissue, which can destroy it. Detailed insight about electron scattering is therefore relevant for the treatment of tumors. It can be used in computer simulations to optimize the destruction of tumors in radiotherapy while sparing healthy tissue," highlights Professor Matthias Kling of the impact of the work. As a next step, the scientists plan to replace the glass nanoparticles with water droplets to study the interaction of electrons with the very substance which makes up the largest part of living tissue.
News Article | May 18, 2017
Today’s computers are faster and smaller than ever before. The latest generation of transistors will have structural features with dimensions of only 10 nanometers. If computers are to become even faster and at the same time more energy efficient at these minuscule scales, they will probably need to process information using light particles instead of electrons. This is referred to as “optical computing”. Fiber-optic networks already use light to transport data over long distances at high speed and with minimum loss. The diameters of the thinnest cables, however, are in the micrometer range, as the light waves — with a wavelength of around one micrometer — must be able to oscillate unhindered. In order to process data on a micro- or even nanochip, an entirely new system is therefore required. One possibility would be to conduct light signals via so-called plasmon oscillations. This involves a light particle (photon) exciting the electron cloud of a gold nanoparticle so that it starts oscillating. These waves then travel along a chain of nanoparticles at approximately 10 percent of the speed of light. This approach achieves two goals: nanometer-scale dimensions and enormous speed. What remains, however, is the energy consumption. In a chain composed purely of gold, this would be almost as high as in conventional transistors, due to the considerable heat development in the gold particles. Tim Liedl, Professor of Physics at Ludwig-Maximilians-Universität München (LMU) and PI at the cluster of excellence Nanosystems Initiative Munich (NIM), together with colleagues from Ohio University, has now published an article in the journal Nature Physics, which describes how silver nanoparticles can significantly reduce the energy consumption. The physicists built a sort of miniature test track with a length of around 100 nanometers, composed of three nanoparticles: one gold nanoparticle at each end, with a silver nanoparticle right in the middle. The silver serves as a kind of intermediary between the gold particles while not dissipating energy. To make the silver particle’s plasmon oscillate, more excitation energy is required than for gold. Therefore, the energy just flows “around” the silver particle. “Transport is mediated via the coupling of the electromagnetic fields around the so-called hot spots which are created between each of the two gold particles and the silver particle,” explains Liedl. “This allows the energy to be transported with almost no loss, and on a femtosecond time scale.” The decisive precondition for the experiments was the fact that Liedl and his colleagues are experts in the exquisitely exact placement of nanostructures. This is done by the DNA origami method, which allows different crystalline nanoparticles to be placed at precisely defined nanodistances from each other. Similar experiments had previously been conducted using conventional lithography techniques. However, these do not provide the required spatial precision, in particular where different types of metals are involved. In parallel, the physicists simulated the experimental set-up on the computer — and had their results confirmed. In addition to classical electrodynamic simulations, Alexander Govorov, Professor of Physics at Ohio University, was able to establish a simple quantum-mechanical model: “In this model, the classical and the quantum-mechanical pictures match very well, which makes it a potential example for the textbooks.”
News Article | May 24, 2017
Scientists at Ludwig-Maximilians-Universität (LMU) in Munich and Friedrich-Schiller-Universität (FSU) Jena, both in Germany, have developed organic semiconductor nanosheets that can easily be removed from a growth substrate and placed on other substrates. Today's computer processors are composed of billions of transistors. These electronic components normally comprise a semiconductor material, insulator, substrate and electrode. Scientists would like to have each of these elements available as transferable sheets, allowing them to design new electronic devices simply by stacking the sheets together. This has now become a reality for the organic semiconductor material pentacene. For the first time, Bert Nickel, a physicist at LMU Munich, and Andrey Turchanin at FSU Jena, together with their teams, have managed to create mechanically-stable pentacene nanosheets. The researchers describe their method for producing these sheets in a paper in Advanced Materials. They first cover a small silicon wafer with a thin layer of a water-soluble organic material and then deposit pentacene molecules on this material to form a film roughly 50nm thick. The next step is crucial: irradiating this film with low-energy electrons causes the topmost three to four levels of pentacene molecular layers to become crosslinked, forming a ‘skin’ that is only about 5nm thick. This crosslinked layer stabilizes the entire pentacene film so well that it can be removed as a sheet from the silicon wafer in water and transferred to another surface using ordinary tweezers. In addition to their ease of transfer, these new pentacene nanosheets have other advantages. For a start, the production method does not require any potentially interfering solvents. In addition, after deposition, the nanosheet sticks firmly to electrical contacts via van der Waals forces, conferring a low contact resistance to the final electronic device. Last but not least, the method should allow organic semiconductor nanosheets to be deposited onto significantly more technologically-relevant substrates than had been possible before. Of particular interest is the extremely high mechanical stability of the newly-developed pentacene nanosheets, allowing them to be applied as free-standing nanomembranes to perforated substrates with dimensions of tens of micrometers. That is equivalent to spanning a 25m pool with a plastic wrap. "These virtually freely suspended semiconductors have great potential," explains Nickel. "They can be accessed from two sides and could be connected through an electrolyte, which would make them ideal as biosensors, for example." "Another promising application is their implementation in flexible electronics for manufacturing of devices for vital data acquisition or production of displays and solar cells," says Turchanin. This story is adapted from material from Ludwig-Maximilians-Universitaet, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.
News Article | May 15, 2017
-- Top-ranked Roman Catholic "Loyola Marymount University" (LMU), rooted in the Jesuit and Marymount tradition and "institutionally committed to Roman Catholicism", claims to offer "the first Master of Arts in Yoga Studies in America".Said to be one of its kind in the world, this Master's program in Yoga Studies, includes studying ancient Hindu scriptures(Song of the Lord) and, besidesand; Sanskrit language, considered a sacred language in Hinduism;and; and translating the sutras and commentary from Patanjali's. It explores yoga's relationship to religion and spirituality.LMU also offers various yoga related Certificate Programs, including Prime of Life Yoga; Yoga, Mindfulness and Social Change (claimed to be "only professional certificate program of its kind"); Yoga Philosophy; Yoga Therapy Rx; Yoga and the Healing Sciences; etc. It also runs Vinyasa Krama Yoga Summer Institute and undertakes a Prison Yoga Project.Hindus have welcomed Catholic LMU for promoting yoga. Hindu statesman Rajan Zed, in a statement in Nevada today, urged all the US universities and colleges to introduce multi-beneficial yoga in the lives of their student communities.Yoga, referred as "a living fossil", was a mental and physical discipline, for everybody to share and benefit from, whose traces went back to around 2,000 BCE to Indus Valley civilization, Zed, who is President of Universal Society of Hinduism, noted.Rajan Zed further said that yoga, although introduced and nourished by Hinduism, was a world heritage and liberation powerhouse to be utilized by all. According to Patanjali who codified it in, yoga was a methodical effort to attain perfection, through the control of the different elements of human nature, physical and psychical.According to US National Institutes of Health, yoga may help one to feel more relaxed, be more flexible, improve posture, breathe deeply, and get rid of stress. According to "2016 Yoga in America Study", about 37 million Americans (which included many celebrities)now practice yoga; and yoga is strongly correlated with having a positive self image. Yoga was the repository of something basic in the human soul and psyche, Zed added.LMU, founded in 1911 and headquartered in Los Angeles (California), claims to take "its fundamental inspiration from the combined heritage of the Jesuits, the Marymount Sisters, and the Sisters of St. Joseph of Orange". Paul S. Viviano, Timothy Law Snyder and Christopher Key Chapple are Trustees Chair, President and Yoga Studies Director respectively of LMU.
News Article | May 8, 2017
D2L's Brightspace Chosen by Top Schools to Reach Every Learner WATERLOO, ON--(Marketwired - May 08, 2017) - Internet2 members continue to choose D2L as their learning management system provider. Three high-profile institutions, Loyola Marymount University (LMU), St. Catherine University and DePaul University, are using the learning technology leader's Brightspace platform to reach every learner. Brightspace will provide personalized learning, enhanced learning experiences, and better learning outcomes for over 40,000 students and faculty across the three universities. "D2L has worked with Internet2 to expand its reach across North America," said John Baker, CEO of D2L. "Together we're delivering an engaging and modern learning experience that's fostering growth at these tremendous institutions, with more to come." Each university is using the technology through Internet2's membership community organization: "This continued momentum highlights the far-reaching collaboration between D2L and Internet2 member institutions, which offers broad functional and financial value to higher education," said Shel Waggener, Senior Vice President, Internet2. "The widespread adoption of new learning technology helps institutions serve students, faculty and administrators to achieve improved results." Last October, D2L announced it had expanded its participation with Internet2 to deliver a portfolio of cost-effective and easy-to-access technology and services tailored to the unique needs of the research and education community. Institutions can purchase D2L's cloud-based technology through Internet2. D2L's Brightspace is a digital learning platform that helps schools and institutions deliver personalized learning experiences in a classroom or online to people anywhere in the world. Created for the digital learner, Brightspace is cloud-based, runs on mobile devices, and offers rich multimedia to increase engagement, productivity and knowledge retention. The platform makes it easy to design courses, create content, and grade assignments, giving instructors more time to focus on what's most important – greater teaching and learning. At the same time, analytics reports track and deliver insights into the performance levels of departments, courses, or individuals. Brightspace was recently named the #1 LMS in Higher Ed by Ovum Research and #1 in Adaptive Learning by eLearning Magazine. In addition, Aragon Research included Brightspace in its highly-coveted Hot Vendors In Learning list. Internet2 is a non-profit, member-driven advanced technology community founded by the nation's leading higher education institutions in 1996. Internet2 serves 317 U.S. universities, 70 government agencies, 43 regional and state education networks and through them supports more than 94,000 community anchor institutions, over 900 InCommon participants, and 78 leading corporations working with our community, and 61 national research and education network partners that represent more than 100 countries. Internet2 delivers a diverse portfolio of technology solutions that leverages, integrates, and amplifies the strengths of its members and helps support their educational, research and community service missions. Internet2's core infrastructure components include the nation's largest and fastest research and education network that was built to deliver advanced, customized services that are accessed and secured by the community-developed trust and identity framework. Internet2 offices are located in Ann Arbor, Mich.; Denver, Colo.; Emeryville, Calif.; Washington, D.C.; and West Hartford, Conn. For more information, visit www.internet2.edu or follow @Internet2 on Twitter. D2L is the software leader that makes the learning experience better. The company's cloud-based platform is easier to use, more flexible, and smart. With Brightspace, companies can personalize the experience for every learner to deliver real results. The company is a world leader in learning analytics: its platform predicts learner performance so that companies can take action in real-time to keep employees on track. Brightspace is used by learners in higher education, K-12, and the enterprise sector, including the Fortune 1000. D2L has operations in the United States, Canada, Europe, Australia, Brazil, and Singapore.www.D2L.com The D2L family of companies includes D2L Corporation, D2L Ltd, D2L Australia Pty Ltd, D2L Europe Ltd, D2L Asia Pte Ltd, and D2L Brasil Soluções de Tecnologia para Educação Ltda. All D2L marks are trademarks of D2L Corporation. Please visit D2L.com/trademarks for a list of D2L marks.
News Article | May 11, 2017
The low oxygen concentrations that prevail in many tumors enhance their propensity to metastasize to other tissues. Researchers at Ludwig-Maximilians-Universitaet (LMU) in Munich led by Professor Heiko Hermeking have now uncovered the molecular mechanism that links the two phenomena. Many actively growing tumors are poorly supplied with blood, which limits the concentration of oxygen available within the tumor, a condition known as hypoxia. Tumor hypoxia has several significant consequences: The relative lack of oxygen partly accounts for the fact that such solid tumors are comparatively resistant to radiation and chemotherapy, and it also promotes the formation of satellite tumors in other tissues. Now researchers led by LMU professor Heiko Hermeking have dissected the mechanisms responsible for the association between tumor hypoxia and metastasis. Their results reveal how hypoxia leads to inhibition of the synthesis of a short RNA molecule that normally suppresses tumorigenesis. The new findings appear in the journal Gastroenterology. Cancers can only develop if the biochemical circuits that control cell proliferation and behavior are inactivated. These safe-guarding mechanisms are mediated by so-called tumor-suppressor proteins, one of which is known as p53. The gene encoding p53 is inactivated in more than half of all tumors. In previous studies Hermeking had shown that p53 induces the transcription of a short RNA - referred to as microRNA-34a (miR-34a) - which plays a central role in tumor suppression. "We observed that, in patients with colon carcinomas, the gene for miR-34a is very frequently inactivated in metastasizing tumors, which are often characterized by relative oxygen deficiency," Hermeking says. He and his colleagues have now shown that, in tumor cells in which the p53 function is compromised, complete loss of miR-34a expression is a direct consequence of hypoxia. In response to low oxygen levels, the tumor cells trigger the synthesis of hypoxia-inducible factor 1a (HIF1a), a protein that directly represses the transcription of miR-34a. Furthermore, this down-regulation of the microRNA is a prerequisite for hypoxia-induced epithelial-to-mesenchymal transition (EMT). In this process, HIF1a activates a genetic program that results in the transformation of non-invasive cells (which grow in a regulated fashion in epithelial sheets) into invasive, migratory cells that can seed new tumors elsewhere. EMTs play important roles in embryonic development and organogenesis, as well as in wound healing, but must be tightly regulated. Among the proteins involved in orchestrating the EMT is PPP1R11. Hermeking's team found that especially high levels of this protein are synthesized in the cells that form the leading edge of an invasive tumor - where the oxygen concentration is expected to be particularly low. In normal cells, on the other hand, the production of PPP1R11 is repressed directly by miR-34a and thus indirectly by the tumor suppressor p53. This ensures that cells divide in a coordinated manner and prevents formation of metastases. "The regulatory antagonism is presumably the reason why metastasizing tumor cells are selected for loss of the p53 gene, which is required for the expression of miR-34a," Hermeking explains. The new findings also have therapeutic implications, for they suggest that metastasizing colon tumors could perhaps be treated with drugs that inhibit the functions of proteins that promote the EMT. Such inhibitors would also be expected to permit reactivation of the expression of miR-34a. "In fact, molecules that act as functional substitutes for miR-34a are now being tested in clinical trials," says Hermeking. This miRNA is of particular interest as a drug target, because it is involved in the control of many regulatory processes. For instance, reintroduction of miR-34a into tumor cells also activates the patient's immune system to attack the tumor. Hermeking's results suggest that hypoxic tumors might be especially susceptible to this approach.
News Article | May 10, 2017
LMU researchers led by Christian Weber show that the chemokine receptor CXCR4 protects the integrity of arterial walls, and define a new mechanism that restricts the deleterious accumulation of cholesterol in atherosclerotic plaques. München, 10-May-2017 — /EuropaWire/ — Atherosclerosis is characterized by the build-up of fat-rich deposits on the inner surfaces of the endothelial cells that form the walls of the blood vessels. The presence of these atherosclerotic “plaques” leads to a chronic inflammation reaction, which can ultimately result in constriction of the vessel and the obstruction of blood flow in major arteries. Research teams led by Professor Christian Weber, Director of the Institute for Prophylaxis and Epidemiology of Cardiovascular Diseases (IPEK) at the LMU Medical Center, have long focused their efforts on understanding the molecular mechanisms that underlie the pathogenesis and progression of the disorder. In two new studies, which appear in the journal Circulation, he and his colleagues now describe two previously unknown mechanisms that help to retard the formation of atherosclerotic plaques. In a project funded by the European Research Council, Weber is investigating the contribution of a class of signal proteins known as chemokines to the pathogenesis of atherosclerosis. Chemokines are small proteins released by various types of immune cells, which interact with specific receptors found on the surfaces of other cells and modulate their function. One of the new papers is devoted to the action of the chemokine CXCL12. Binding of CXCL12 by its receptor CXCR4 plays a significant role in controlling the recruitment of immune cells to sites of tissue inflammation. The results reported demonstrate that the interaction between CXCL12 and CXCR4 serves to inhibit the development of atherosclerotic plaques. “We have shown, for the first time, that activation of the chemokine receptor CXCR4 in endothelial cells limits the progression of atherosclerosis,” Weber says. The researchers investigated the role of the signaling pathway by specifically inducing the deletion of the gene for the receptor in either the endothelial cells of the arteries or in the underlying smooth-muscle cells. In a mouse model, they found that the resulting depletion of the protein in either cell type stimulated the formation of atherosclerotic deposits. “As the amount of activated receptor falls, the more permeable the vessel wall becomes,” as Dr. Yvonne Döring, first author of the paper, explains. This in turn enables pro-inflammatory cells to migrate into the underlying tissues. Taken together, these observations imply that CXCR4 is essential for maintenance of the integrity of the endothelial cell layer. In addition, loss of the receptor in smooth-muscle cells altered their character and reduced their contractile responses. Subsequent analyses of variants of naturally occurring CXCR4 gene variants in humans confirmed that reduced expression of the receptor is indeed associated with increased risk for coronary heart disease. (Circulation 2017) In a further study carried out at the IPEK, Professor Sabine Steffens and Dr. Petteri Rinne (who is now at Turku University in Finland) identified a novel function of the receptor MC1-R. MC1-R is best known for its role in activating synthesis of the pigment melanin in the skin, which acts as an endogenous sunscreen and protects against the mutagenic effects of UV radiation. However, the receptor has a variety of other functions. For example, it is thought to be involved in the regulation of inflammatory responses, which raises the question of whether it too might play a role in atherosclerosis. “MC1-R is expressed on the surface of macrophages,” says Steffens (macrophages are the immune system’s waste-disposal service; they ingest and dispose of dead and dying cells and other debris), “and we have now shown that it regulates so-called reverse cholesterol transport in these cells.” Specifically, the study demonstrates that activation of MC1-R promotes the extrusion of excess cholesterol from the macrophages found within atherosclerotic lesions, and actively prevents its re-uptake. Conversely, inhibition of the MC1-R signal pathway stimulates the transport of cholesterol into macrophages. These findings imply that, like CXCR4, MC1-R also inhibits the development of atherosclerosis. Excessive uptake of cholesterol converts macrophages into so-called foam cells, which are known to contribute to the inflammation reactions within atherosclerotic lesions. This in turn increases the risk that plaques may rupture and obstruct blood-flow, which can lead to a heart attack or a stroke. (Circulation 2017) For more on this topic, see: