In normal human liver cells (left), Plasmodium parasites (red) develop into a circular, exoerythrocytic form that gives rise to malaria. But in cells lacking CXCR4 (right), the parasite remains trapped in its rod-shaped sporozoite form. Newswise — Researchers in Japan have discovered that the Plasmodium parasites responsible for malaria rely on a human liver cell protein for their development into a form capable of infecting red blood cells and causing disease. The study, which will be published June 12 in the Journal of Experimental Medicine, suggests that targeting this human protein, known as CXCR4, could be a way to block the parasite’s life cycle and prevent the development of malaria. According to the World Health Organization, there were an estimated 219 million cases of malaria in 2017, resulting in the deaths of approximately 435,000 people. Infected mosquitoes transmit Plasmodium parasites to humans in the form of rod-shaped sporozoites that travel to the liver and invade liver cells (hepatocytes). Once inside these cells, the Plasmodium sporozoites develop into spherical exoerythrocytic forms (EEFs) that eventually give rise to thousands of merozoites capable of spreading into red blood cells and causing malaria. “It seems likely that the transformation of Plasmodium sporozoites into EEFs is tightly controlled so that it only occurs in hepatocytes and not at earlier stages of the parasite’s life cycle,” says Masahiro Yamamoto, a professor at the Research Institute for Microbial Diseases of Osaka University. “However, we know very little about the host factors that regulate the differentiation of sporozoites in infected hepatocytes.” In the new study, Yamamoto and colleagues discovered that a hepatocyte protein called CXCR4 helps Plasmodium sporozoites transform into EEFs. Depleting this protein from human liver cells reduced the ability of sporozoites to develop into EEFs. Moreover, mice pretreated with a drug that inhibits CXCR4 were resistant to malaria, showing reduced levels of parasites in the blood and significantly higher survival rates following Plasmodium infection. Yamamoto and colleagues also identified a cell signaling pathway that causes hepatocytes to produce more CXCR4 in response to Plasmodium infection and determined that the protein aids the parasite’s development by raising the levels of calcium inside the cells. “Our study reveals that CXCR4 blockade inhibits Plasmodium sporozoite transformation in hepatocytes,” Yamamoto says. “Most anti-malaria drugs targeting Plasmodium-derived molecules eventually lead to drug resistance in these parasites. However, inhibitors targeting human proteins such as CXCR4 might avoid this problem and could be used prophylactically to prevent the development of malaria. Moreover, the CXCR4 inhibitor used in this study is already widely used in humans undergoing treatment for blood cancers, which could accelerate its repurposing as a new way of combating malaria.” Bando et al. 2019. J. Exp. Med. http://jem.rupress.org/cgi/doi/10.1084/jem.20182227?PR
Newswise — Researchers at the Fralin Biomedical Research Institute at Virginia Tech Carilion have revealed how a genetic message to produce healthy heart tissue is altered in the body during stress and aging to contribute to sudden cardiac death. The discovery published in today’s (Tuesday, May 28) Cell Reports centers on communication between heart cells and allows for the potential of developing targeted therapies to help people at risk of arrhythmias and heart attacks. Led by senior author James Smyth, an assistant professor with the Fralin Biomedical Research Institute’s Center for Heart and Reparative Medicine Research, scientists focused on how generally overlooked, untranslated regions of RNA that flank the genetic code become shorter during aging or while under stressful conditions. The slight change influences how the cell reads a genetic message to make proteins and build important cellular structures including channels that electrically couple the cells of the heart together to allow for coordinated contractions and the resultant efficient pumping of blood. “Typical understanding of the biology used to be as straightforward as ‘here’s the message, make a protein,’” said Smyth, who is also an assistant professor in the Department of Biological Sciences of the College of Science. “We know it is not that simple anymore. It's actually dynamically regulated. If the cell is stressed, that message will be read differently.” “Using traditional means of detecting levels of message or levels of RNA in cells during stress or aging, you wouldn't see the changes we saw,” Smyth said. “We focused on how this untranslated region could be changed during stress and how that could influence how the cell reads the message.” During stress, such as conditions of oxygen deprivation that occur during ischemic heart disease or stroke, the untranslated regions become shorter, which changes how the cell synthesizes the encoded protein products and limits intercellular communication in heart cells. Researchers focused on a gene called GJA1, which provides instructions to make Connexin 43, the gap junction protein. Gap junctions directly couple the contents of adjacent cells and are essential to normal heart function, where they enable the rapid and organized spread of electrical impulses between cells that cause contractions of the heart muscle. Malfunctions in this electrical communication can cause signals in the heart to become disorganized and lead to irregularities that can lead to sudden cardiac death. “The more we identify these molecular, very fundamental mechanisms, the sharper we're going to get in therapeutics,” Smyth said. “By manipulating this biology, we are figuring out the downstream factors acting on the DNA or RNA. Hopefully we have found a powerful angle to develop therapeutics, such as small molecules for precise, safer treatments.” Researchers studied cardiac cells, mouse cell lines, and aged mouse heart tissue where they found increases in the major GJA1-encoded protein — which should spell healthier conditions between heart cells — but they also observed increased, but truncated, untranslated regions of RNA that shut down synthesis of other GJA1-encoded proteins that modulate gap junction formation. Scientists also exposed cardiac cells derived from human-induced pluripotent stem cells to reduced oxygen, which also revealed an increase in truncated, untranslated regions, demonstrating that this is a common response of untranslated regions of RNA to physiological stress that is conserved across species. The response also takes place in a variety of cells. “This activity occurs in cancer, heart, and brain cells,” Smyth said. “When we saw that, we knew it was a powerful piece of biology, because it was happening everywhere.” The study is the latest resulting from more than four years of work by members of the Smyth lab and others at Fralin Biomedical, a university-level research institute of Virginia Tech. Michael Zeitz, a research scientist at Fralin Biomedical Research Institute, is the first author of the study, which also involved Stefanie Robel, an assistant professor at Fralin Biomedical Research Institute and the School of Neuroscience of the Virginia Tech College of Science; postdoctoral associate Thomas Taetzsch, and associate professor Gregorio Valdez of the Fralin Biomedical Research Institute and the Virginia Tech College of Science. Fralin Biomedical Research Institute graduate students Patrick Calhoun of the Department of Biological Sciences; and Carissa James and Kijana George of the Translational Biology, Medicine and Health graduate program, were also members of the research team. The work was supported by the National Institute of Health and the American Heart Association.
Newswise — People who drink alcohol while using medications that interact with it are higher risk of harm from overdose, falls, and traffic accidents. In recent years, there has been a documented increase in alcohol-related adverse drug reactions and acute emergency room admissions. One group of medicines, known as central nervous system (CNS) depressants, was implicated in over 40% of alcohol-related adverse drug reactions between 2005 and 2011. CNS depressants include the ‘sedative─hypnotic’ medications (anxiolytics and sleeping medications) as well as prescription opioids such as hydrocodone and oxycodone. To further investigate the interplay of alcohol and prescription medications, researchers at Washington University have assessed the changing prevalence of CNS depressant use among regular drinkers. They analyzed data from over 37,000 adults who participated in the US National Health and Nutrition Examination survey (which is overseen by the Centers for Disease Control and Prevention) between 1999 and 2014. They found that among participants who reported drinking regularly (once a week or more), the proportion that used sedative─hypnotic medications doubled to 6% between 1999 and 2014 ─with the increase driven by a large rise in prescribed sleep medications. The prevalence of prescribed opioid use among regular drinkers remained relatively high at around 4%, despite the known risks. While regular drinkers were less likely than infrequent or non-drinkers to use anxiolytics or opioid medications, they were just as likely to use sleep medications. The research also showed that people aged 40 plus were up to five times as likely as those in their twenties to use sedative─hypnotic medications; rates of binge drinking are also known to have increased in the over 40 age group in recent years. The number of people at risk for adverse alcohol─drug reactions has therefore risen markedly. Exposure to sedative─hypnotic medications may still be increasing, whereas prescription opioid use is stable but alarmingly common among regular drinkers. The over forties in particular continue to face an unnecessarily high risk of alcohol-related adverse drug reactions and poor outcomes.
UB-led research reveals how fluctuating air pollution at the Beijing Olympics affected local residents’ bodies at the level of metabolites Newswise — BUFFALO, N.Y. — A new University at Buffalo study based on levels before, during and after the Beijing Olympics reveals how air pollution affects the human body at the level of metabolites. Researchers found that 69 metabolites changed significantly when air pollution changed. Their results were published today (May 29) in the journal Environmental Health Perspectives. The study identified two major metabolic signatures, one consisting of lipids and a second that included dipeptides, polyunsaturated fatty acids, taurine, and xanthine. Many of those metabolites are involved in oxidative stress, inflammation, cardiovascular and nervous systems, researchers note. The findings are based on the Beijing Olympics Air Pollution study, conducted during the 2008 Olympic Games in China, when temporary air pollution controls were implemented. The study was led by UB epidemiologist Lina Mu. The study enrolled 201 adults prior to Beijing’s air quality improvement initiative, when air pollution was high. Researchers followed them during the Games, when air pollution was low, and afterward, when levels returned to their usual high in the city of 21 million people. A subset of 26 non-smokers aged 30 to 65 was selected for the metabolomics analysis. Metabolites are small molecules that are the end products of environmental exposures, such as air pollution, and body metabolism. “Think of our body as a society. These metabolites fulfill different positions, such as teacher, farmer, worker, soldier. We need each one functioning properly in order to maintain a healthy system,” said Mu, PhD, associate professor of epidemiology and environmental health in UB’s School of Public Health and Health Professions. “Our study found that the human body had systemic changes at the metabolite level before, during and after the 2008 Beijing Olympics, when ambient air pollution changed drastically,” said Zhongzheng Niu, a PhD candidate and a paper co-author. The molecules mostly belonged to the lipid and dipeptide families. The study provides researchers with a broader view of the molecular mechanism underlying the impact of air pollution on the human body. Most previous studies only looked at a small number of molecules. However, the human body is complex and molecules affect one another. Mu and her colleagues used the “omics” method, a new platform that can measure a whole collection of all detectable metabolites — 886 in their study — simultaneously. Instead of examining these molecules one by one, Mu and her team used network analysis to analyze them all together. “We found that these metabolites together depicted a relatively comprehensive picture of human body responses to air pollution,” said paper co-author Rachael Hageman Blair, associate professor of biostatistics at UB. She and her team developed the novel analysis method used in the study. The responses include cellular stability, oxidative stress, anti-oxidation and inflammation. Researchers measured metabolomics repeatedly when air pollution was high, low and high. Such a design mimicked a “natural experiment” while controlling for variations unrelated to air pollution changes. This provided stronger evidence than previous studies. Air pollution is an environmental exposure that can’t be avoided by people who live in places like Beijing. The World Health Organization reports that 91 percent of the world’s population lives in places where air quality exceeds WHO guidelines. Once inhaled, air pollutants stimulate the body’s respiratory system, including the nose and lungs. Some cells in the body may be directly insulted by these air pollutants, their membrane may be broken, their secretion may be disordered, and they may send out signaling molecules to other organs for subsequent responses, Mu explains. Metabolites are all these broken membranes, secreted products and signals. “Capturing these molecules tells us what is going on when people are exposed to air pollution,” Mu said. Air pollution also induces cellular oxidative stress, which breaks cell membranes. Researchers found that some molecules that serve as building blocks of cell membranes were elevated when air pollution levels rose. Broken cell membranes release different kinds of lipid molecules. Some of these lipid molecules, with the help of enzymes, turn to inflammatory molecules, which could be harmful to the body. “The good thing is that we also found some protective molecules, namely antioxidants, also increased when air pollution is high, indicating our body has a defense system to reduce harm,” Mu said. Studies such as this one may help identify individuals most vulnerable to air pollution, as well as finding potential biological pathways to guide treatment that reduces harm to the body, Mu said. Mu’s UB co-authors include Richard Browne, associate professor of biotechnical and clinical laboratory sciences, Jacobs School of Medicine and Biomedical Sciences; Matthew Bonner, associate professor of epidemiology and environmental health; and Mya Swanson, data manager/statistician, Department of Epidemiology and Environmental Health. Furong Deng of Peking University is also a co-author.
Newswise — Researchers have gained a greater understanding of the biology of staphylococcus skin infections in mice and how the mouse immune system mobilizes to fight them. A study appears this week in the Proceedings of the National Academy of Sciences of the United States of America. Community acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) typically causes skin infections but can spread throughout the body to cause invasive infections such as sepsis, and possibly death. These CA-MRSA bacteria are becoming increasingly resistant to multiple antibiotics, making them especially difficult to treat. In healthy people, the body’s natural immune defenses typically keep CA-MRSA infections in the skin, and appropriate antibiotics can effectively treat them. However, patients who are immunocompromised have difficulty fighting the bacteria, which can become invasive and cause life-threating infections. “While the human immune responses that protect against S. aureus infections have remained elusive, we have as a start determined in mice that protective immunity against MRSA is orchestrated by specific immune cells called gamma/delta T cells, which upon infection travel from the lymph nodes to the infected skin to initiate the protective host response,” says Lloyd Miller, M.D., Ph.D., an associate professor of dermatology at the Johns Hopkins University School of Medicine. Miller notes that CA-MRSA and other multidrug resistant bacteria are becoming a bigger problem in health care, as most antibiotics no longer work against these infections and few new antibiotics are being developed in the pipeline. In the case of CA-MRSA, sometimes only two or three oral antibiotics remain that can treat these infections. Miller and his team are working to understand the specific details of the mouse immune system’s MRSA-fighting program to develop a way to probe the human immune system to develop alternative immune-based treatments that could work along with antibiotic regimens, or eliminate the need for antibiotics altogether. In their previous research, Miller and his team discovered that a cytokine protein called IL-17 is critical for turning on the host defense against staph infections. However, until know, they did not know which cell produced it, particularly which type of T cell. Also, there are two types of IL-17, one called IL-17A and the other IL-17F, but the researchers didn’t know if one or the other or both are required to mount the host response against CA-MRSA. So they teamed up with colleagues at the National Institutes of Health (NIH) who had engineered mice that would glow different colors depending on which form of IL-17 the mouse was making. The researchers then injected MRSA in the skin of these mice and found that the infected skin glowed green and red. They concluded this to mean that both types of IL-17 are involved in the immune response to the bacteria. “We were fairly certain that IL-17 was being made by T cells but we didn’t know if it was the T cells that are normally in the skin or T cells that were migrating from the lymph nodes to the site of infection,” says Miller. Using the same glowing mice, the team asked what would happen if it blocked T cells from leaving the lymph nodes and treated the mice with FTY720 (fingolimod), a drug normally used to treat multiple sclerosis by keeping T cells from mobilizing from lymph nodes and minimizing inflammatory responses. After administering FTY720 to the mice that had an MRSA infection, the researchers saw no glowing, which informed them that the IL-17 seen at the site of the MRSA infection in the skin was made solely by T cells that had migrated from the lymph nodes. The researchers then extracted cells from the infection site as well as cells from the lymph nodes both before and after infecting the mice with MRSA. They labeled these cells with different colors depending on the types of proteins found on the surface of each cell. In mice without MRSA, a particular type of T cells called gamma/delta T cells expanded dramatically after infecting the mice with MRSA. The team then set out to determine which exact cells were expanding. Working with colleagues at the University of California, Davis, the team determined the genetic sequences of all of the T cell receptors in the mouse lymph nodes before and after infecting the mice with MRSA. They found that only one type of gamma/delta T cell clone expanded with a specific T cell receptor. What’s called the V gamma 6/Vdelta 4(+) expanded from 2% to over 20% to fight MRSA. “We think that this one single gamma/delta T cell clone is mediating the protective IL-17 response in mice,” says Miller. “What’s more is that these results really relied on having the latest technologies available to scientists today. We couldn’t have figured this out 10 years ago, for example. “While it is not known if there is an exact parallel cell type in humans, we’re encouraged that we can find something similar, which means we could be well on our way to developing new T cell-based therapies against MRSA.” Next steps for this team involve examining the T cell responses in humans to determine if a similar mechanism exists. Other authors on this paper include Mark Marchitto, Carly Dillen, Haiyun Liu, Robert Miller, Nathan Archer, Roger Ortines, Martin Alphonse, Alina Marusina, Advaitaa Ravipati, Yu Wang, Angel Byrd, Bret Pinsker, Isabelle Brown, Emily Zhang, Shuting Cai, Nathachit Limjunyawong and Xinzhong Dong of Johns Hopkins; Alexander Merleev, Scott Simon and Emanual Maverakis of the University of California, Davis; Michael Yeaman of the University of California, Los Angeles; Wei Shen and Scott Durum of the National Institutes of Health and Rebecca O’Brien of National Jewish Health. This work was supported by the National Institutes of Arthritis and Musculoskeletal and Skin Diseases (R01AR069502 and R01AR073665), the National Institute of Allergy and Infectious Diseases (R21AI126896 [L.S.M.], U01AI124319 [to MRY] and R01AI129302 [to SIS]), and federal funds from the National Cancer Institute under Contract Number HHSN261200800001E (MRA) (to S.D.) and the Office of the National Institutes of Health Director (1DP2OD008752 [to EM]).
Newswise — PITTSBURGH, May 14, 2019 – The same sources thought to inflict oxidative stress on cells—pollution, diesel exhaust, smoking and obesity—also are associated with shorter telomeres, the protective tips on the ends of the chromosomal shoelace. A new study from the University of Pittsburgh, published today in Molecular Cell, provides the first smoking gun evidence that oxidative stress acts directly on telomeres to hasten cellular aging. “Telomeres consist of hundreds of guanine bases, which are sinks for oxidation,” said senior author Patricia Opresko, Ph.D., professor of environmental and occupational health at the Pitt Graduate School of Public Health and UPMC Hillman Cancer Center. “Is it just a coincidence? Or could it be true that oxidizing those guanines in the telomeres is really contributing to shortening?” To find out for sure, Opresko needed some way to inflict oxidative stress on telomeres and nowhere else. So, she enlisted the help of Marcel Bruchez, Ph.D., professor of biological sciences and chemistry and director of the Molecular Biosensors and Imaging Center at Carnegie Mellon University. Bruchez developed a method for zeroing in on the telomeres using a special light-activated molecule that latches onto the telomere and delivers localized free radicals—the molecular agent of oxidative stress—on command. “One of the main challenges to targeting oxidative damage to specific loci in living cells has been achieving precise temporal and dose-control of this damage,” Bruchez said. “By combining telomere targeting with our optochemogenetic generation of singlet oxygen, we are able to selectively control when and how hard the oxidative stress is applied specifically at the telomere sites.” The researchers repeatedly exposed cultured cancer cells to this targeted oxidation procedure, mimicking conditions of environmental oxidative stress and inflammation, and, indeed, they saw the telomeres break and shorten with each cell division, despite repair efforts by the telomere lengthening enzyme telomerase. As the DNA repair machinery tried to fix the broken telomeres, the ends of the chromosomes often fused together, destabilizing the genome and preventing cells from dividing properly. Whereas telomere shortening spells bad news for healthy cells, Opresko said, the flipside is that targeting telomeres might offer a way to fight cancer. With short enough telomeres, cancer cells would stop dividing. “If we can understand what causes telomere shortening and how cells compensate for that,” Opresko said, “then we’ll be in a better position to design intervention strategies that protect telomeres in healthy cells and target telomeres in cancer cells.” Other authors on this study include Elise Fouquerel, Ph.D., Ryan Barnes, Ph.D., Shikhar Uttam, Ph.D., and Simon Watkins, Ph.D., all of Pitt. This work was supported by grants from the National Institutes of Health (K99ES027028, R01ES022944, R01CA207342, R01ES02842, R21/R33ES025606 and R01EB017268).
Many in their 50s and early 60s buy supplements or do puzzles in hopes of protecting brain health, but may miss out on effective strategies Newswise — ANN ARBOR, MI – Many Americans in their 50s and early 60s are worried about declining brain health, especially if they have loved ones with memory loss and dementia, a new national poll finds. But while the majority of those polled say they take supplements or do puzzles in an effort to stave off brain decline, very few of them have talked with their doctors about evidence-based ways to prevent memory loss. As a result, they may miss out on proven strategies to keep their brains sharp into their later years, says the poll team from the University of Michigan. In all, nearly half of respondents to the National Poll on Healthy Aging felt they were likely to develop dementia as they aged, and nearly as many worried about this prospect. In reality, research suggests that less than 20 percent of people who have reached age 65 will go on to lose cognitive ability from Alzheimer’s disease, vascular dementia or other conditions. Despite the brain-related concerns of so many respondents, only five percent of the entire group, and 10 percent of those who said they had a family history of dementia, said they had talked with a healthcare provider about how to prevent memory problems. At the same time, 73 percent said they do crossword puzzles or brain games, or take supplements, to try to keep their minds sharp. Neither strategy has been shown to have a beneficial effect by major research studies. The poll, carried out by the U-M Institute for Healthcare Policy and Innovation with support from AARP and Michigan Medicine, U-M’s academic medical center, asked 1,028 adults aged 50 to 64 a range of brain health questions. “While many people in this age range expressed concerns about losing memory, and say they take active steps to prevent it, most haven’t sought advice from medical professionals, who could help them understand which steps actually have scientific evidence behind them,” says Donovan Maust, M.D., M.S., a U-M geriatric psychiatrist who helped design the poll and analyze the results. “Many people may not realize they could help preserve brain health by managing their blood pressure and blood sugar, getting more physical activity and better sleep, and stopping smoking.” Maust worked with poll director Preeti Malani, M.D., U-M dementia researcher Kenneth Langa, M.D., PhD, and the poll team. Effects of experience The team found stark differences in perceptions and viewpoints between the one-third of poll respondents who said they had a family history of dementia, or had served as a caregiver to a loved one with dementia, and those without such experience or family links. For instance, 73 percent of those with a family history of dementia said they themselves were somewhat or very likely to develop the condition as they aged – compared with just 32 percent of those with no family history. The gap between the two groups was nearly as large when the research team asked if poll respondents were worried about developing dementia later in life. “Staying mentally sharp is the number one concern for older adults,” says Alison Bryant, Ph.D., senior vice president of research for AARP. “According to the Global Council on Brain Health, people should concentrate on those things we know can improve brain health—eating a healthy diet, getting adequate sleep, exercising, and socializing with friends and family.” Attitudes toward dementia research Differences also emerged between those who had dementia in their families, and those without, when the researchers asked respondents if they’d consider taking part in dementia-related research. Seventy-one percent of those with a family history of dementia said they’d be willing to give researchers a sample of their DNA, compared with 51 percent of the other respondents. Nearly twice as many of those with a family history said they’d take part in a test of a new medicine aimed at preventing dementia, or a new treatment for people diagnosed with dementia. The poll also suggests that researchers searching for better ways to prevent, diagnose or treat dementia may have to work hard to attract participants. Thirty-nine percent of those who wouldn’t be willing to give a DNA sample said it was because they didn’t want their DNA to be stored in a repository. Similarly, 37 percent of those who said they wouldn’t take part in studies of new prevention or treatment strategies expressed concerns about being a “guinea pig”, and one-fifth worried about potential harms. Healthy lives, healthy attitudes The poll also shows that a greater percentage of adults in their 50s and early 60s who say they get adequate sleep and exercise, ate healthily and were active socially at least several times a week felt their memory was just as sharp now as it was when they were younger, compared to those who do not engage in these healthy behaviors as frequently. But those who said their health was fair or poor, or who reported that they didn’t often engage in healthy lifestyle practices, were much more likely to say that their memory had declined since their younger years. In all, 59 percent of those polled said their memory was slightly worse than it used to be. “For anyone who wants to stay as sharp as possible as they age, the evidence is clear: focus on your diet, your exercise, your sleep and your blood pressure,” says Malani. “Don’t focus on worrying about what might happen, or the products you can buy that promise to help, but rather focus on what you can do now that research has proven to help.” The National Poll on Healthy Aging results are based on responses from a nationally representative sample of 1,028 adults aged 50 to 64 who answered a wide range of questions online. Questions were written, and data interpreted and compiled, by the IHPI team. Laptops and Internet access were provided to poll respondents who did not already have them. A full report of the findings and methodology is available at www.healthyagingpoll.org, along with past National Poll on Healthy Aging reports
Newswise — Researchers at UC Davis Health and UC San Francisco have found a way to teach a computer to precisely detect one of the hallmarks of Alzheimer’s disease in human brain tissue, delivering a proof of concept for a machine-learning approach to distinguishing critical markers of the disease. Amyloid plaques are clumps of protein fragments in the brains of people with Alzheimer's disease that destroy nerve cell connections. Much like the way Facebook recognizes faces based on captured images, the machine learning tool developed by a team of University of California scientists can “see” if a sample of brain tissue has one type of amyloid plaque or another, and do it very quickly. The findings, published May 15 in Nature Communications, suggest that machine learning can augment the expertise and analysis of an expert neuropathologist. The tool allows them to analyze thousands of times more data and ask new questions that would not be possible with the limited data processing capabilities of even the most highly trained human experts. “We still need the pathologist,” said Brittany N. Dugger, PhD, an assistant professor in the UC Davis Department of Pathology and Laboratory Medicine and lead author of the study. “This is a tool, like a keyboard is for writing. As keyboards have aided in writing workflows, digital pathology paired with machine learning can aid with neuropathology workflows.” In this study, she partnered with Michael J. Keiser, PhD, an assistant professor in UCSF’s Institute for Neurodegenerative Diseases and Department of Pharmaceutical Chemistry, to determine if they could teach a computer to automate the laborious process of identifying and analyzing tiny amyloid plaques of various types in large slices of autopsied human brain tissue. For this job, Keiser and his team designed a “convolutional neural network” (CNN), a computer program designed to recognize patterns based on thousands of human-labeled examples. To create enough training examples to teach the CNN algorithm how Dugger analyzes brain tissue, the UCSF team worked with her to devise a method that allowed her to rapidly annotate or label tens of thousands of images from a collection half a million close-up images of tissue from 43 healthy and diseased brain samples. Like a computer dating service that allows users to swipe left or right to label someone’s photo “hot” or “not,” they developed a web platform that allowed Dugger to look one-at-a-time at highly zoomed-in regions of potential plaques and quickly label what she saw there. This digital pathology tool — which researchers called “blob or not” — allowed Dugger to annotate more than 70,000 “blobs,” or plaque candidates, at a rate of about 2,000 images per hour. The UCSF team used this database of tens of thousands of labeled example images to train their CNN machine-learning algorithm to identify different types of brain changes seen in Alzheimer’s disease. That includes discriminating between so-called cored and diffuse plaques and identifying abnormalities in blood vessels. The researchers showed that their algorithm could process an entire whole-brain slice slide with 98.7% accuracy, with speed only limited by the number of computer processors they used. (In the current study they used a single graphics card like those used by home gamers.) The team then performed rigorous tests of the computer’s identification skills to make sure its analysis was biologically valid. “It’s notoriously hard to know what a machine-learning algorithm is actually doing under the hood, but we can open the black box and ask it to show us why it made its predictions,” Keiser explained. Keiser emphasized that the machine learning tool is no better at identifying plaques than Dugger, the neuropathologist who trained the computer to find them in the first place. “But it’s tireless and scalable,” he said. “It’s a co-pilot, a force multiplier that extends the scope of what we can accomplish and lets us ask questions we never would have attempted manually. For example, we can look for rare plaques in unexpected places that could give us important clues about the course of the disease. To promote use of the tool, the researchers have made it and the study data publicly available online. This has already generated interactions with other researchers who have evaluated the data and the algorithms in their own labs. In the future, the researchers hope that such algorithms will become a standard part of neuropathology research, trained to help scientists analyze vast amounts of data, tirelessly seeking out patterns that could unlock new insights into causes and potential treatments for the disease. “If we can better characterize what we are seeing, this could provide further insights into the diversity of dementia,” Dugger said. “It opens the door to precision medicine for dementias.” She added, “These projects are phenomenal examples of cross-disciplinary translational science; neuropathologists, a statistician, a clinician, and engineers coming together, forming a dialogue and working together to solve a problem.” Other study authors included: Charles DeCarli, Lee-Way Jin and Laurel Beckett from UC Davis; Ziqi Tang of UCSF and Tsinghua University in Beijing, China, and Kangway V. Chuang of UCSF. The study was funded by an NIH P30 AG010129, Paul G. Allen Family Foundation Distinguished Investigator Award and the China Scholarship Council. The authors declare no conflicting interests.
Newswise — In experiments with pregnant mice infected with the Zika virus, Johns Hopkins Medicine researchers report they have successfully used a long-standing immunosuppressive drug to diminish the rate of fetal deaths and birth defects in the mice’s offspring. The U.S. Food and Drug Administration-approved medicine, anakinra, once commonly used to treat rheumatoid arthritis and other autoimmune diseases in newborns and adults, has largely been replaced by more effective drugs. However, in the Zika-infected mouse experiments, the drug appears to interfere with inflammation in the pregnant animals’ placentas, the researchers say. There also is evidence the drug directly reduces inflammation in fetal brains. A report on the findings was published in the April issue of the Journal of Clinical Investigation Insights. “Until now, the focus of research has been on finding vaccines and antiviral drugs, but our study strongly suggests that the placental immune response should not be overlooked as a target for treatment,” says Irina Burd, M.D., Ph.D., associate professor of gynecology and obstetrics and director of the Integrated Research Center for Fetal Medicine at the Johns Hopkins University School of Medicine. “Using an FDA-approved drug already shown to be safe in infants shortens the time that we may be able to quickly start clinical trials and get a potentially effective preventative measure approved and available to help decrease the harmful effects of Zika.” According to the U.S. Centers for Disease Control and Prevention, 10% of babies born in the U.S. to women with a Zika infection during pregnancy develop fetal brain birth defects that range from slow head growth to microcephaly, a condition marked by a very small head due to brain abnormalities. Zika can be spread by infected mosquitos or unprotected sex from an infected person, and is passed from a pregnant woman to her unborn child. Pregnant women with Zika are also at increased risk for miscarriage. In Burd’s earlier work in 2014 in the American Journal of Reproductive Immunology with mouse models of newborn brain injury, she found that anakinra protected newborn mice from brain damage when the pregnant mothers were treated with inflammatory protein, notably interleukin-1beta. For this study, the researchers first wanted to see how Zika may affect the placenta in pregnant mice with the virus to try to figure out the cause behind the fetal deaths and birth defects. They compared pregnant mice infected with strains of Zika found in Nigeria, Puerto Rico and Brazil to pregnant mice not infected with the virus. They found that mice with Zika turned on the gene that makes the protein for interleukin-1beta at higher levels in the placenta compared to non-infected mice. They also found higher levels in the placenta of the interleukin-1beta protein. Because Zika causes early overproduction of interleukin-1beta, the researchers turned to the drug anakinra to test its potential for alleviating the damaging effects to fetal mice of mothers with Zika. The researchers injected mice placentas with either 10 milligrams per kilogram of anakinra or with fluid without the drug. After eight days of in utero exposure to the virus, 1.8% of the 322 mice infected with Zika but not given the drug had birth defects such as contracted limbs with tightened muscles, kinked tails, and fused fingers and toes. None of the mice given the drug showed signs of these birth defects. Comparable to the defects shown in the mice, human babies with microcephaly-caused defects may have limb contractures. The researchers say it is important to note that the defects noted in the mice may vary from humans because each species develops differently. The researchers also say that more fetal mice treated in utero with anakinra survived to full-term birth compared to untreated mice. In the pregnant mice with Zika, 39.2% of the mothers had fetal deaths. In mice with Zika given the drug in utero, 20.8% of the mothers had fetal deaths. Next, the researchers wanted see if the drug protected the brains of the mice born to mothers with Zika from inflammation. The researchers took mice immune system cells from the brain, called microglia, and infected them with Zika. After a day, microglia with Zika had made more cells, showing that the Zika was causing inflammation. They treated microglia infected with Zika with anakinra, and after 24 hours there were fewer microglia, suggesting that the drug protected the brain cells from inflammation. Five days after birth, the mice born treated with anakinra completed neurological and physical assessments that tested balance, movement, vision, depth perception and coordination. For example, in the coordination test, the mice were put on their backs and researchers measured how long it would take them to flip over. Mice given the drug flipped over to become upright about one second faster on average than mice without treatment, which the researchers say was significant for this kind of test. The researchers believe the drug was responsible for reversing the neurodevelopmental abnormalities that caused longer performance times. “Currently, there is no cure for Zika, but our study suggests that there may be FDA-approved medications like anakinra that have the potential to combat some of the worst effects of the virus,” says Sabra Klein, Ph.D., associate professor of molecular microbiology and immunology at the Johns Hopkins University Bloomberg School of Public Health. “ “Future studies are urgently needed to determine the possible benefits of such a drug in people,” says Burd. “More and more countries are affected by Zika. And it would be great for us to continue doing this research with the same rigor and funding so we can continue to fight this not only in the United States but, globally.” Other researchers who participated in the study included Jun Lei, Meghan Vermillion, Bei Jia, Han Xie, Li Xie, Michael McLane, Jeanne Sheffield, Andrew Pekosz and Amanda Brown of the Johns Hopkins University School of Medicine and Bloomberg School of Public Health. This work was supported by funds from the Johns Hopkins Integrated Research Center for Fetal Medicine, Sheikh Abdullah Bugshan Fund, Sherrilyn and Ken Fisher Center for Environmental Infectious Diseases, ABOG/AAOGF Bridge Funding Award, the National Institutes of Health Office of the Director (T32 OD011089) and the Eunice Kennedy Shriver National Institute of Child Health and Human Development grant for training veterinarians for careers in biomedical research (R01HD097608). The researchers report no conflicts of interest.
Results of a first-in-humans trial presented at AATS 99th Annual Meeting indicates the safety of a novel treatment for ischemia reperfusion injury where none has existed to-date. Newswise — TORONTO – May 5, 2019 – A new study, presented today at the American Association for Thoracic Surgery’s 99thAnnual Meeting, shows that a potential treatment for ischemia- reperfusion injury is safe for humans. Building upon three decades of preclinical animal studies, this NIH-funded trial demonstrated, for the first time, the safety of Regadenoson (an adenosine 2A receptor agonist) in human lung transplant patients. Ischemia-reperfusion injury is a major source of morbidity and mortality in lung transplant patients, and contributes to the less than optimal survival rates in lung transplant recipients. Adenosine 2AR agonists like Regadenoson offer a potentially novel treatment for this common inflammatory complication where none exists today. Researchers found no dose limiting toxicities in the non-randomized trial and no 30-day mortality. The TCV lab at University of Virginia, under the direction of Dr. Irving Kron, has spent three decades studying the efficacy of A2AR agonists for lung transplant in rodents and large animals. In humans, Regadenoson, (LexiscanTM), is clinically approved as a bolus for myocardial imaging, but its safety profile in the high risk lung transplant population as an infusion had not been established. This clinical trial was designed to assess the safety of regadenoson in human lung transplant recipients as a prequel to an efficacy trial. “It is gratifying to see this research move from bench to bedside, with decades of work culminating in a clinical trial,” said Senior Author, Dr. Christine Lau, Professor of Surgery in the Division of Thoracic & Cardiovascular Surgery at the University of Virginia. “As the field of lung transplants evolves rapidly, we continue to see ischemia-reperfusion injury, making the potential of a new treatment an exciting development.” With safety established, the next step for testing efficacy is a multi-institutional, randomized trial. Additionally, because the treatment appears effective whether the drug is given to the donor lung or the recipient, future trials will use ex-vivolung profusion to administer the drug only to the donor lung, eliminating any risk to the patient. Presenting author Dr. Joshua A. Boys, MD explained, “This treatment has the potential to be the next big thing in the world of lung transplants. With further study, this can quickly move from a quality of life improvement therapy to one that greatly improves survival for the long term.”