Biomarker May Predict Early Alzheimer’s Disease

Researchers at Sanford Burnham Prebys Medical Discovery Institute (SBP) have identified a peptide that could lead to the early detection of Alzheimer’s disease (AD). The discovery, published in Nature Communications, may also provide a means of homing drugs to diseased areas of the brain to treat AD, Parkinson’s disease, as well as glioblastoma, brain injuries and stroke.

“Our goal was to find a new biomarker for AD,” says Aman Mann, Ph.D., research assistant professor at SBP who shares the lead authorship of the study with Pablo Scodeller, Ph.D., a postdoctoral researcher at SBP. “We have identified a peptide (DAG) that recognizes a protein that is elevated in the brain blood vessels of AD mice and human patients. The DAG target, connective tissue growth factor (CTGF) appears in the AD brain before amyloid plaques, the pathological hallmark of AD.”

“CTGF is a protein that is made in the brain in response to inflammation and tissue repair,” explains Mann. “Our finding that connects elevated levels of CTGF with AD is consistent with the growing body of evidence suggesting that inflammation plays an important role in the development of AD.”

The research team identified the DAG peptide using in vivo phage display screening at different stages of AD development in a mouse model. In young AD mice, DAG detected the earliest stage of the disease. If the early appearance of the DAG target holds true in humans, it would mean that DAG could be used as a tool to identify patients at early, pre-symptomatic stages of the disease when treatments already available may still be effective.

“Importantly, we showed that DAG binds to cells and brain from AD human patients in a CTGF-dependent manner” says Mann. “This is consistent with an earlier report of high CTGF expression in the brains of AD patients.”

“Our findings show that endothelial cells, the cells that form the inner lining of blood vessels, bind our DAG peptide in the parts of the mouse brain affected by the disease,” says Erkki Ruoslahti, M.D., Ph.D., distinguished professor at SBP and senior author of the paper. “This is very significant because the endothelial cells are readily accessible for probes injected into the blood stream, whereas other types of cells in the brain are behind a protective wall called the blood-brain barrier. The change in AD blood vessels gives us an opportunity to create a diagnostic method that can detect AD at the earliest stage possible.

“But first we need to develop an imaging platform for the technology, using MRI or PET scans to differentiate live AD mice from normal mice. Once that’s done successfully, we can focus on humans,” adds Ruoslahti.

“As our research progresses we also foresee CTGF as a potential therapeutic target that is unrelated to amyloid beta (Aβ), the toxic protein that creates brain plaques,” says Ruoslahti. “Given the number of failed clinical studies that have sought to treat AD patients by targeting Aβ, it’s clear that treatments will need to be given earlier—before amyloid plaques appear—or have to target entirely different pathways.

“DAG has the potential to fill both roles—identifying at risk individuals prior to overt signs of AD and targeted delivery of drugs to diseased areas of the brain. Perhaps CTGF itself can be a drug target in AD and other brain disorders linked to inflammation. We’ll just have to learn more about its role in these diseases”.

Immune cells may heal bleeding brain after strokes

While immune cells called neutrophils are known to act as infantry in the body’s war on germs, a National Institutes of Health-funded study suggests they can act as medics as well. By studying rodents, researchers showed that instead of attacking germs, some neutrophils may help heal the brain after an intracerebral hemorrhage, a form of stroke caused by ruptured blood vessels. The study suggests that two neutrophil-related proteins may play critical roles in protecting the brain from stroke-induced damage and could be used as treatments for intracerebral hemorrhage.

“Intracerebral hemorrhage is a damaging and often fatal form of stroke for which there are no effective medicines,” said Jaroslaw Aronowski, M.D., Ph.D., professor, department of neurology, at the University of Texas Health Science Center at Houston, and senior author of the study published in Nature Communications. “Our results are a hopeful first step towards developing a treatment for this devastating form of stroke.”

Accounting for 10 to 15 percent of all strokes, intracerebral hemorrhages happen when blood vessels rupture and leak blood into the brain, often leading to death or long-term disability. Chronic high blood pressure is the leading risk factor for these types of strokes. The initial phase of damage appears to be caused by the pressure of blood leaking into the brain. Over time, further damage may be caused by the accumulation of toxic levels of blood products, infiltrating immune cells, and swelling.

Decades of research suggest that neutrophils are some of the earliest immune cells to respond to a hemorrhage, and that they may both harm and heal the brain. In this study, the researchers found that interleukin-27 (IL-27), a protein that controls the activity of immune cells, may shift the role of neutrophils from harming the brain to helping with recovery.

Injections of IL-27 after a hemorrhage helped mice recover. Days after the strokes, the treated mice had better mobility, including walking, limb stretching and navigating holes in a floor. In contrast, injections of an antibody that blocked natural IL-27 activity slowed recovery. The brains of the mice treated with IL-27 also showed less damage. They had less swelling around the hemorrhages and lower levels of iron and the blood protein hemoglobin, both of which are toxic at high levels.

“This study shines a spotlight on the critical role the immune system may play in helping the brain heal after a hemorrhage or stroke and opens new avenues for stroke treatment strategies,” said Jim Koenig, Ph.D., program director at the NIH’s National Institute of Neurological Disorders and Stroke.

Neutrophils are born in bone marrow and carry chemicals in hundreds of densely filled packets called granules, which look like dark spots under a microscope. Typically, when the body senses bacteria or an injury, neutrophils rush to the invasion site and release germ killing chemicals from the granules. This appears to happen minutes after a hemorrhagic stroke.

In this study, the researchers suggested that after a hemorrhagic stroke the brain secretes high levels of IL-27, which leads to a second wave of neutrophils arriving with granules filled with higher amounts of healing molecules. IL-27 levels were elevated in the brain and blood of the mice an hour after hemorrhages and stayed high for three days, peaking at 24 hours later. Further experiments suggested that brain cells called microglia produced the IL-27 in response to the presence of red blood cells.

Once released, IL-27 molecules appeared to travel to the bones of the mice, infiltrated the marrow, and changed the role newborn neutrophils played in response to a stroke. When the researchers extracted newborn neutrophils from the bones of mice and treated them with IL-27, the chemical raised the activity of genes associated with healing, especially lactoferrin, while reducing the activity of genes associated with killing cells. Conversely, treating mice with an IL-27 neutralizing antibody after a hemorrhage lowered lactoferrin gene activity.

“Our results suggested that IL-27 links the brain to the bones,” said Dr. Aronowski. “We can use these results as a source for ideas for developing potential treatments for hemorrhagic stroke.”

Finally, the researchers showed the iron binding protein lactoferrin may protect the brain from intracerebral hemorrhagic strokes. Mice and rats injected with lactoferrin 30 minutes after hemorrhages recovered faster and had reduced brain damage as compared to animals given placebos. In one set of experiments, the researchers found that giving mice lactoferrin 24 hours after a stroke was also effective.

“Lactoferrin appears to have a long treatment window,” said Dr. Aronowski. “This means lactoferrin might one day be used to help patients recover from intracerebral hemorrhage.”

Dr. Aronowski’s team is taking the next steps towards testing lactoferrin treatment in patients.

Biologists Find New Source for Brain’s Development

A team of biologists has found an unexpected source for the brain’s development, a finding that offers new insights into the building of the nervous system.

The research, which appears in the journal Science, discovered that glia, a collection of non-neuronal cells that had long been regarded as passive support cells, in fact are vital to nerve-cell development in the brain.

“The results lead us to revise the often neuro-centric view of brain development to now appreciate the contributions for non-neuronal cells such as glia,” explains Vilaiwan Fernandes, a postdoctoral fellow in New York University’s Department of Biology and the study’s lead author. “Indeed, our study found that fundamental questions in brain development with regard to the timing, identity, and coordination of nerve cell birth can only be understood when the glial contribution is accounted for.”

The brain is made up of two broad cell types, nerve cells or neurons and glia, which are non-nerve cells that make up more than half the volume of the brain. Neurobiologists have tended to focus on the former because these are the cells that form networks that process information.

However, given the preponderance of glia in the brain’s cellular make-up, the NYU researchers hypothesized that they could play a fundamental part in brain development.

To explore this, they examined the visual system of the fruit fly. The species serves as a powerful model organism for this line of study because its visual system, like the one in humans, holds repeated mini-circuits that detect and process light over the entire visual field.

This dynamic is of particular interest to scientists because, as the brain develops, it must coordinate the increase of neurons in the retina with other neurons in distant regions of the brain.

In their study, the NYU researchers found that the coordination of nerve-cell development is achieved through a population of glia, which relay cues from the retina to the brain to make cells in the brain become nerve cells.

“By acting as a signaling intermediary, glia exert precise control over not only when and where a neuron is born, but also the type of neuron it will develop into,” notes NYU Biology Professor Claude Desplan, the paper’s senior author.

The research was supported, in part, by a grant from the National Institutes of Health (EY13012).

Courtesy of Vilaiwan M. Fernandes, Desplan Lab, NYU’s Department of Biology.

Demand for Diagnostic for Early Detection of Brain Injury After Surprising Study On NFL Players Brains And CTE

Chronic Traumatic Encephalopathy (CTE) is a slowly developing neurodegenerative condition typical of athletes involved in contact sports. This was evidenced in a recent study in which nearly every former NFL player whose brain was investigated had suffered from CTE.  The findings released this week were part of a study conducted by two leading medical institutions devoted to CTE research — the VA Boston Healthcare System and Boston University School of Medicine — and the results concluded that of 111 NFL players’ brains that were donated to science after the players’ deaths, 110 (99%) were found to have CTE. The disease currently can only be diagnosed post-mortem.

The study, published in the Journal of the American Medical Association, researchers looked at the brains of 202 deceased people who had played football at various levels, from high school to the NFL. (The brains had been donated to a brain bank at Boston University for further study.) The researchers analyzed the brains for signs of CTE and spoke to family members about the players’ histories.

Dr. Jesse Mez, an assistant professor of neurology at Boston University School of Medicine, one of the co-authors of the study, said that “the goal of doctors and scientists is to eventually be able to diagnose CTE among the living”. Dr. Mez said that the goal of doctors and scientists is to eventually diagnose CTE among the living, so that research and development of treatment methods can be expedited. “One of the important points is to develop bio-markers and figure out ways of differentiating this disease (CTE) from other neurodegenerative diseases, most certainly Alzheimer’s.” he adds.

Today, the analysis is made post-mortem (after death) from individuals who engaged to donate their brain for research. Medicortex Finland Oy, a biotechnology company in Finland, is developing a diagnostic tool for rapid sideline detection of brain injury.

This is exactly what Medicortex Finland Oy is aiming at. Medicortex is working towards the identification of a Traumatic Brain Injury (TBI) biomarker in body fluids and incorporating it into a quick and reliable diagnostic kit that can be easily used by sideline paramedics, first responders and healthcare professionals, and also by people with no medical profession. A rapid TBI test will furthermore help prioritize evacuation order in mass casualties and reframe from administration of contraindicated medications.

Recently Medicortex completed analyzing the results from the first clinical trial. The trial consisted of patients that were hospitalized due to a head injury. The clinical results confirmed the presence of a unique biomarker that will be further developed into a new diagnostic tool. Medicortex’s test utilizes easily accessible, non-invasive samples of body fluids. It is easy to understand the result of the test which enables straightforward confirmation or ruling-out of TBI without a need of a medical professional. Suspected athletes can be tested for TBI after a prominent hit to the head at sport arenas. The test can be performed by the coach of the team or by a First Aid group in charge.

Dr. Adrian Harel, Chief Executive Officer of Medicortex Finland, says that “Brain injury is a devastating condition leading to mortality if not diagnosed. We have the opportunity to develop the first portable non-invasive kit for head injury and concussion to help the patients and families that so desperately need it is remarkable.”

Medicortex Finland Oy (http://www.medicortex.fi) is an early clinical stage company dedicated to improving the diagnostics and treatment of Traumatic Brain Injury (TBI). Medicortex is currently developing biomarker diagnostics for rapid detection of TBI. The second goal will be to develop an innovative drug to halt the progression of brain injury. Medicortex was founded by and it is headed by a neurobiologist and entrepreneur Adrian Harel (PhD, MBA). The company operates in Turku, Finland.

Rare Type of Immune Cell Responsible for Progression of Heart Inflammation to Heart Failure in Mice

A new study in mice reveals that eosinophils, a type of disease-fighting white blood cell, appear to be at least partly responsible for the progression of heart muscle inflammation to heart failure in mice.

In a report on the findings, published in The Journal of Experimental Medicine on March 16, researchers found that while eosinophils are not required for heart inflammation to occur, they are needed for it to progress to a condition known as inflammatory dilated cardiomyopathy (DCMi) in mice. The discovery, they say, advances information about the impact of eosinophils on heart function.

“Other studies have shown that people with high levels of eosinophils develop a number of heart diseases. This new work has provided more details about how these immune system cells may lead to deterioration of heart muscle function in mice in a way that lets us draw some parallels to human disease processes,” says Daniela Cihakova, M.D., Ph.D., associate professor of pathology at the Johns Hopkins University School of Medicine and the paper’s senior author.

Heart inflammation, or myocarditis, is rarely diagnosed because it doesn’t always cause severe symptoms and it requires a biopsy to be taken from the patient’s heart. This makes it difficult to study the outcomes of the disease. “We don’t understand why the hearts of some people will heal while those of others develop chronic disease,” says Cihakova.

Different types of myocarditis are distinguished based on the type of immune cell that predominates the inflammation of the heart. For example, in eosinophilic myocarditis, numerous eosinophils infiltrate the heart. It is not known if some types of myocarditis are more likely to progress to DCMi than others. “Our studies show that the presence of eosinophils in the heart makes mice more likely to get DCMi following myocarditis. And if there are a lot of eosinophils, the mice develop even more severe heart failure,” says Nicola Diny, a Ph.D. student in the Bloomberg School of Public Health and the study’s first author. “It will be important to test if the same is true in patients. That way, we may be able to intervene early and prevent DCMi.”

This study, says Cihakova, is the first to examine the role eosinophils play in the development and severity of heart inflammation, and the subsequent progression of inflammation to DCMi. The study addresses a National Institutes of Health-identified need for preclinical models and a clearer understanding of how eosinophils drive heart damage.

For the study, Cihakova and her team first induced myocarditis in two groups of mice: normal mice and a group of mice genetically modified to be eosinophil-deficient. Myocarditis was induced through a process called experimental autoimmune myocarditis, in which mice are immunized with a peptide from heart muscle cells to initiate an immune response against the heart. After 21 days, the researchers found similar levels of acute inflammation in the hearts of both groups by studying the hearts’ tissue. But when the team checked the mice’s hearts later on for evidence of heart failure, the differences between the eosinophil-deficient and the normal mice were striking. The normal mice developed heart failure, while the eosinophil-deficient mice showed no signs of reduced heart function.

“These surprising results told us that it is not the overall severity of inflammation but rather the types of immune cells in the heart that decide whether myocarditis develops into heart failure,” says Diny.

The researchers also examined the hearts for fibrosis, or scar tissue, which develops when mammalian (including human) heart muscles die. This type of scar tissue is also found in DCMi. Although both groups of mice had similar degrees of scar tissue, the eosinophil-deficient mice’s heart functions weren’t negatively affected, while the normal mice developed DCMi.

“This told us that in the absence of eosinophils, heart function can be preserved despite scar tissue formation,” Cihakova says. “It’s also important to note that although eosinophils accounted for just 1 to 3 percent of all heart-infiltrating cells in normal mice, this small percentage can still drive heart failure.”

In another set of experiments, the research team used genetically modified mice, called IL5Tg mice, which have an excess of the protein IL5 that causes the body to make eosinophils. The IL5Tg mice had more inflammation in the atria, or upper chambers of the heart, compared to normal mice in the acute stage and more atrial scar tissue in the chronic stage. IL5Tg mice also had more heart-infiltrating cells in general. Eosinophils accounted for more than 60 percent of heart-infiltrating cells in the IL5Tg mice’s hearts, compared to only 3 percent in normal mice. When the team examined the heart function some 45 days after the start of the experiment, the IL5Tg mice had developed severe DCMi.

To examine whether humans with eosinophil-driven myocarditis also developed inflammation in the atria, the researchers obtained heart tissue samples and cardiac MRI scans from three patients seen at The Johns Hopkins Hospital, all of whom had confirmed eosinophil-driven inflammation.

The images showed that two patients had either inflammation or scar tissue in the atria, which suggests that atrial inflammation and/or scar tissue may also be a feature in humans with eosinophil-driven inflammation, Cihakova says.

To determine whether the IL5 protein is necessary for DCMi development, the research team next examined IL5-deficient mice. The scientists found that they had both inflammation and DCMi severity similar to that of normal mice, suggesting that the IL5 protein is not necessary for DCMi to develop.

Finally, to confirm the differences between the effects of IL5 and eosinophils, the team bred the eosinophil-deficient mice to have excess IL5. Compared to normal mice, these mice showed no decrease in heart function and appeared completely protected from DCMi, which confirms that it is the eosinophils themselves, not high levels of IL5, that are responsible for DCMi development, the investigators say.

To learn more about how eosinophils might drive DCMi progression, the investigators built on the knowledge that eosinophils harbor granules, some of which can kill cells, while others change the function of cells.

“We didn’t see any differences in cell death between the normal mice and those with or without too many eosinophils, so we became interested in the molecules that can change the function of other cells,” says Diny.

In particular, one protein, called IL4, caught the researchers’ attention. Other studies had shown that IL4 made by eosinophils has diverse functions in liver repair and fat tissue. “We wondered if this protein from eosinophils may also be important in the heart,” Cihakova says.

First, the research team used a mouse in which cells that make IL4 turned fluorescent green, thereby allowing researchers to tell where IL4 is made. The team found that eosinophils accounted for the majority of IL4-producing cells. When they used mice that lacked IL4 in all cells, these mice were completely protected from DCMi, just like the eosinophil-deficient mice.

Finally, to determine whether IL4 specifically from eosinophils is necessary for DCMi development, the team used genetically modified mice with no IL4 in their eosinophils but with IL4 in other heart-infiltrating cells. These mice developed less severe DCMi compared to normal mice, which confirms that eosinophils are responsible for DCMi development through IL4.

“The take-home message is that inflammation severity doesn’t necessarily determine long-term disease progression, but specific infiltrating cell types — eosinophils, in this case — do,” says Cihakova. Because eosinophil-driven inflammation is so clinically rare, the percentage of people who develop DCMi is unknown, she notes.

While no drugs are currently available to stop or delay the development of DCMi, the researchers hope their findings will help establish a novel target for IL4-blocking medicines that might be used to treat people with myocarditis, possibly preventing disease progression and the need for heart transplantation.

Pregnancy leads to changes in the mother’s brain

Pregnancy involves radical hormone surges and biological adaptations, but the effects on the brain are still unknown. In this study a team of researchers compared the structure of the brain of women before and after their first pregnancy. This is the first research to show that pregnancy involves long-lasting changes – at least for two years post-partum – in the morphology of a woman’s brain.

Using magnetic resonance imaging, the scientists have been able to show that the brains of women who have undergone a first pregnancy present significant reductions in grey matter in regions associated with social cognition.

The researchers believe that such changes correspond to an adaptive process of functional specialization towards motherhood. “These changes may reflect, at least in part, a mechanism of synaptic pruning, which also takes place in adolescence, where weak synapses are eliminated giving way to more efficient and specialized neural networks”, says Elseline Hoekzema, co-lead author of the article.

According to Erika Barba, the other co-lead author, “these changes concern brain areas associated with functions necessary to manage the challenges of motherhood”.

In fact, researchers found that the areas with grey matter reductions overlapped with brain regions activated during a functional neuroimaging session in which the mothers of the study watched images of their own babies.

In order to conduct the study, researchers compared magnetic resonance images of 25 first-time mothers before and after their pregnancy, of 19 male partners, and of a control group formed by 20 women who were not and had never been pregnant and 17 male partners. They gathered information about the participants during five years and four months.

The results of the research directed by Òscar Vilarroya and Susanna Carmona demonstrated a symmetrical reduction in the volume of grey matter in the medial frontal and posterior cortex line, as well as in specific sections of, mainly, prefrontal and temporal cortex in pregnant women. “These areas correspond to a great extent with a network associated with processes involved in social cognition and self-focused processing”, indicates Susanna Carmona.

The analyses of the study determine with great reliability whether any woman from the study had been pregnant depending on the changes in the brain structure. They were even able to predict the mother’s attachment to her baby in the postpartum period based on these brain changes.

The study took into account variations in both women who had undergone fertility treatments and women who had become pregnant naturally, and the reductions in grey matter were practically identical in both groups.

Researchers did not observe any changes in memory or other cognitive functions during the pregnancies and therefore believe that the loss of grey matter does not imply any cognitive deficits, but rather: “The findings point to an adaptive process related to the benefits of better detecting the needs of the child, such as identifying the newborn’s emotional state. Moreover, they provide primary clues regarding the neural basis of motherhood, perinatal mental health and brain plasticity in general”, says Oscar Vilarroya.

 

Weston Brain Institute Funds Clinical Trials of New Alzheimer’s Treatment

Electrocranial stimulation offers hope for Alzheimer’s patients

Funding for clinical trials of a new treatment for Alzheimer’s disease has been announced by the Weston Brain Institute. Dr. Zahra Moussavi, Canada Research Chair in Biomedical Engineering in the Faculty of Engineering, is receiving $1,737,960 for her project on investigating the efficacy of high-frequency rTMS treatment for Alzheimer’s disease.

Alzheimer’s disease has no known cure and is called the pandemic of the century. Recent trials applying repetitive transcranial magnetic stimulation (rTMS) in Alzheimer’s patients have reported encouraging results in improving or stabilizing cognition. This proposal is the first large placebo-controlled double-blind study designed with sufficient statistical rigor to measure the efficacy of rTMS treatment in Alzheimer’s.

“The Weston Brain Institute is pleased to support this kind of critical high-risk, high-reward work,” said Alexandra Stewart, Executive Director at the Weston Brain Institute.

“If successful, Dr. Moussavi’s work with rTMS will be a significant step forward in developing effective treatments for Alzheimer’s disease,” Stewart said.

Moussavi will lead a team of local, national and international collaborators on this research that includes: Drs. Mandana Modirrousta (Psychiatry), Colleen Millikin (Clinical Health Psychology), Xikui Wang (Statistics), Behzad Mansouri (Neurology), and Craig Omelan (Psychiatry) in collaboration with colleagues from McGill (Montreal – Drs. Lesley Fellows and Lisa Koski) and Monash (Australia – Dr. Paul Fitzgerald) universities.

“All Manitobans will benefit from the research discoveries this funding will fuel,” says Dr. John (Jay) Doering, Associate Vice-President (Partnerships) at the University of Manitoba. “New treatments for Alzheimer’s disease are being sought worldwide. Dr. Moussavi’s research program will result in better quality of life for patients, families and caregivers.”

Transcranial Magnetic Stimulation (TMS) is a procedure in which a current passes through a coil placed on the scalp producing a magnetic field. The magnetic field passes through the skull to the brain, wherein a small current is induced. Application of repetitive(r) TMS at either low or high frequencies has been used for treatment of many neurological and neurodegenerative disorders but is still at the research stage in all except depression, for which rTMS is approved for treatment worldwide.

Genetic ‘Switch’ Identified As Potential Target For Alzheimer’S Disease

A team at the MRC Clinical Sciences Centre (CSC), based at Imperial College London, has found an important part of the machinery that switches on a gene known to protect against Alzheimer’s Disease.

Working in collaboration with scientists at the Hong Kong University (HKU) and the Erasmus University in Rotterdam, CSC associate professor Richard Festenstein explored the steps by which this Neuroglobin gene is gradually switched on, or up-regulated.

Neuroglobin has previously been shown to protect against Alzheimer’s disease in mice in which it makes the protective Neuroglobin. It is thought that the gene might play a protective role early in the disease in patients, but appears to be down-regulated as the disease progresses. It may therefore prove useful in developing new ways to try to prevent or treat this common cause of dementia, for which there is currently no cure.

Professor Festenstein and Dr Tan-Un from HKU, with help from Professor Sjaak Phillipsen at the Erasmus University, examined how the Neuroglobin gene ‘folds up’ in the cell using a technique called chromosome conformation capture. In results published today in the journal Nucleic Acids Research, they showed that a particular region of DNA, outside the coding region of the Neuroglobin gene itself, loops round to make contact with the start of the gene.

They tested the ability of this newly-identified DNA region to switch on the Neuroglobin gene using two approaches. First, they linked the DNA region directly to another so-called ‘reporter’ gene, and demonstrated simply that it does indeed act as an up-regulator. Second, they used the new ‘Crispr’ technique of gene editing to completely remove this section of DNA from the cell, and showed that the Neuroglobin gene was no longer switched on.

Together, the results gave the team confidence that this newly-identified DNA region is indeed a powerful switching mechanism of the Neuroglobin gene.

As Neuroglobin is thought to be protective in Alzheimer’s, it may be possible in the future to use this ‘switch’ in developing new treatments, such as gene therapy. Such therapeutic approaches require a compact ‘chunk’ of DNA to be most efficient. Importantly, the team pinpointed the position of the new regulatory region, and found that it is some distance away from the Neuroglobin gene itself. It may now be possible to remove the less relevant sections of DNA in between the Neuroglobin gene and its regulator to create an efficient therapeutic gene therapy unit. It may be that this target may prove useful not only in Alzheimer’s but also in other neurodegenerative diseases.

Biomarkers May Help Better Predict Who Will Have a Stroke

People with high levels of four biomarkers in the blood may be more likely to develop a stroke than people with low levels of the biomarkers, according to a study published in the August 24, 2016, online issue of Neurology®, the medical journal of the American Academy of Neurology.

“Identifying people who are at risk for stroke can help us determine who would benefit most from existing or new therapies to prevent stroke,” said study author Ashkan Shoamanesh, MD, of McMaster University in Hamilton, Canada, and a member of the American Academy of Neurology. “Future research could also investigate whether lowering the levels of these biomarkers or blocking their action could be a way to prevent strokes. However, our study does not provide evidence that these markers are validated well enough to be implemented in clinical practice.”

For the study, researchers from the Boston University Schools of Medicine and Public Health measured the levels of 15 biomarkers associated with inflammation in the blood of people from the Framingham Heart Study Offspring Cohort who had never had a stroke. The 3,224 participants were an average age of 61 at the start of the study and were followed for an average of nine years. During that time, 98 people had a stroke.

Of the 15 biomarkers, four were associated with an increased risk of stroke. People with elevated homocysteine were 32 percent more likely to have a stroke. Those with high vascular endothelial growth factor were 25 percent more likely; those with high ln-C reactive protein were 28 percent more likely; and those with high ln-tumor necrosis factor receptor 2 were 33 percent more likely to have a stroke during the study.

Adding these four biomarkers to an existing method of predicting a person’s stroke risk based on factors such as age, sex, cholesterol and blood pressure, called the Framingham Stroke Risk Profile, improved the ability to predict who would develop a stroke.
Shoamanesh noted that the study was observational. It shows a relationship between high levels of the biomarkers and stroke; it does not establish that the high levels cause stroke. He also noted that the biomarkers were measured only once and researchers did not account for infections, chronic diseases or other conditions that could have affected the results. In addition, study participants are mainly of European ancestry and the results may not apply to other populations.

The study was supported by Framingham Heart Study’s National Heart, Lung, and Blood Institute contract, National Institute of Neurological Disorders and Stroke, National Institute on Aging and National Institutes of Health.

The American Academy of Neurology is the world’s largest association of neurologists and neuroscience professionals, with 30,000 members. The AAN is dedicated to promoting the highest quality patient-centered neurologic care. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as Alzheimer’s disease, stroke, migraine, multiple sclerosis, concussion, Parkinson’s disease and epilepsy.

To learn more about stroke, please visit http://www.aan.com/patients.

Experimental Drug Cancels Effect From Key Intellectual Disability Gene in Mice

A University of Wisconsin-Madison researcher who studies the most common genetic intellectual disability has used an experimental drug to reverse — in mice — damage from the mutation that causes the syndrome.

The condition, called fragile X, has devastating effects on intellectual abilities.

Fragile X affects one boy in 4,000 and one girl in 7,000. It is caused by a mutation in a gene that fails to make the protein FMRP. In 2011, Xinyu Zhao, a professor of neuroscience, showed that deleting the gene that makes FMRP in a region of the brain that is essential to memory formation caused memory deficits in mice that mirror human fragile X.

The deletions specifically affected neural stem cells and the new neurons that they form in the hippocampus.

Tantalizingly, Zhao’s 2011 study showed that reactivating production of FMRP in new neurons could restore the formation of new memories in the mice. But what remained unclear was exactly how the absence of FMRP was blocking neuron formation, and whether there was any practical way to avert the resulting disability.

Now, in a study published on April 27 in Science Translational Medicine, Zhao and her colleagues at the Waisman Center at UW-Madison have detailed new steps in the complex chain reaction that starts with the loss of FMRP and ends up with mice that cannot remember what they had recently been sniffing.

This study’s newfound understanding of the biochemical chain of events became the basis for identifying an experimental cancer drug called Nutlin-3, which blocks the reaction.

In the new study, mice with the FMRP deletion took Nutlin-3 for two weeks. When tested four weeks later, they regained the ability to remember what they had seen — and smelled — in their first visit to a test chamber.

Statistically, the memory capacities of normal mice and fragile X models that were treated with Nutlin-3 were identical.

Still, many hurdles remain before the advance can be tested on human patients, Zhao says. “We are a long way from declaring a cure for fragile X, but these results are promising.”

Fragile X appears after birth, says Zhao. “Parents start to notice something is wrong, but even if they get an accurate diagnosis, there is no treatment at present. I’m encouraged because affecting this gene’s pathway does seem to reverse the memory impairment.”

The mouse memory test relied on curiosity. “We placed two objects in an enclosure and let the mice run around,” Zhao says. “Mice are naturally curious, so they explore and sniff each one. We take them out after 10 minutes, replace one object with a different one, wait 24 hours and put the mouse back in. If the mouse has normal learning ability, it will recognize the new object and spend more time with it. Mice without the FMRP gene don’t remember the old object, so they spend a similar amount of time on each one.”

The behavioral assessment was done by different people, says Zhao. “First author Yue Li, a postdoctoral researcher at Waisman, ran the test and sent the video to Michael Stockton, an undergraduate working on the project.” Stockton timed how and where each mouse was exploring, “but he had no idea which mouse was which,” Zhao says. “It was fantastic to see such clear data.”

Two other undergraduates, Jessica Miller and Ismat Bhuiyan (who is now in graduate school) and postdoctoral fellows Brian Eisinger and Yu Gao also worked on the study. The Wisconsin Alumni Research Foundation has applied for a patent on the discovery.

Nutlin-3, which can block the last stage of the chain reaction set off by a mutation in the FMRP gene, is in phase 1 trial for the treatment of the eye cancer retinoblastoma. Finding a new use for a drug that is approved, or that like Nutlin-3 and several derivatives, has entered the approval process, may shorten the lengthy FDA process, says Zhao.

The dose used in the trial — only 10 percent of the dose proposed for cancer chemotherapy — caused no apparent harm, she says. “We measured body weight and activity. So far, the mice look healthy and happy.”

Because more than one-third of fragile X patients are also diagnosed with autism, the study may shed light on that condition.

In any case, it’s far too soon to declare victory over fragile X, Zhao stresses. “There are many hurdles. Among the many questions that need to be answered is how often the treatment would be needed. Still, we’ve drawn back the curtain on fragile X a bit, and that makes me optimistic.”

Sophisticated ‘Mini-Brains’ Add to Evidence of Zika’s Toll on Fetal Cortex

Studying a new type of pinhead-size, lab-grown brain made with technology first suggested by three high school students, Johns Hopkins researchers have confirmed a key way in which Zika virus causes microcephaly and other damage in fetal brains: by infecting specialized stem cells that build its outer layer, the cortex.

The lab-grown mini-brains, which researchers say are truer to life and more cost-effective than similar research models, came about thanks to the son of two Johns Hopkins scientists and two other high school students who were doing summer research internships. They had the idea to make the equipment for growing the mini-brains with a 3-D printer. These so-called bioreactors, and the mini-brains they foster, should open other new and valuable windows into human brain development, brain disorders and drug testing — and perhaps even produce neurons for treatment of Parkinson’s disease and other disorders, the investigators say.

A report on the research appears online April 22 in the journal Cell.

“We have been working for three years to develop a better research model of brain development, and it’s fortunate we can now use this one to shed light on the major public health crisis posed by Zika infections,” says Hongjun Song, Ph.D., professor of neurology and neuroscience at the Johns Hopkins University School of Medicine’s Institute for Cell Engineering. “This more realistic, 3-D model confirms what we suspected based on what we saw in a two-dimensional cell culture: that Zika causes microcephaly — abnormally small brains and heads — mainly by attacking the neural progenitor cells that build the brain and turning them into virus factories.”

In recent years, researchers in various fields have begun to grow tiny organs from human stem cells to get a better view of development and disease, and speed the search for new drugs. But existing techniques for creating and working with mini-brains were limiting because of the organ’s complexity, Song says. Though the mini-brains themselves are about the size of a pinhead, the bioreactors where they grew were comparatively large, about the size of a soda can. That made working with the mini-brains expensive, given the high cost of the nutrients needed to cultivate human stem cells in the lab, he says, as well as the expense of chemical growth factors that guide the tissue to organize itself like a real brain. Few labs could afford to grow enough mini-brains to be useful for research, Song says, and those that did produced tissues with cells specialized for different parts of the brain mixed together at random.

Song and his wife and research partner, Guo-li Ming, M.D., Ph.D., professor of neurology, neuroscience, and psychiatry and behavioral sciences, found a way to improve the bioreactors from an unexpected source: their son and two other high school students, from New York and Texas, who spent a summer working in the lab. The students had worked with 3-D printers and thought they could be the key to producing a better bioreactor, one that would fit over commonly used 12-well laboratory plates and spin the liquid and cells inside at just the right speed to allow the cells to form brains.

Of course, it wasn’t that simple, Song says. Graduate student Xuyu Qian and postdoctoral fellow Ha Nam Nguyen, Ph.D., spent years determining factors such as what that optimum speed was, as well as which chemicals and growth factors should be added at what times to yield the desired result.

The group has so far used the new bioreactor, dubbed SpinΩ, to make three types of mini-brains mimicking the front, middle and back of a human brain. They used the forebrain, the first mini-brain with the six layers of brain cell types found in the human cortex, for the current study on Zika.

“One thing the mini-brains allowed us to do was to model the effects of Zika virus exposure during different stages of pregnancy,” says Ming. “If infection occurred very early in development, the virus mostly infected the mini-brains’ neural progenitor cells, and the effects were very severe. After a while, the mini-brains would stop growing and disintegrate. At a later stage, mimicking the second trimester, Zika still preferentially infected neural progenitor cells, but it also affected some neurons. Growth was slower, and the cortex was thinner than in noninfected brains.”

These different effects correspond to what clinicians have seen in infants born to women who contracted Zika during pregnancy, as well as miscarriages, she notes, namely that the earlier in pregnancy Zika infection occurs, the more severe its effects.

The research group’s next step will be to test drugs already FDA-approved for other conditions on the mini-brains to see whether one might provide some protection against Zika. And they included 3-D printing files for SpinΩ in the new paper so that researchers anywhere can print their own bioreactors with just a few hundred dollars in materials. Song says one possible future use could be to grow so-called dopaminergic neurons for transplant, to replace those that die off in Parkinson’s disease. “This is the next frontier of stem cell biology,” he says.