Researchers at Lund University in Sweden headed by Professor Singerup Linse and Erik Helistrand have recently identified a molecular mechanism behind the crucial step in Alzheimer’s that leads to the death of brain cells.
The neurological disease is associated, as a general statement, with memory loss and changes in personality. The research at Lund helps identify on a molecular level the chemical reactions which cause plaque, a major benchmark in the progression of the disease, to form. Amyloid beta in its soluble form, found naturally within the brain, acts as a building block and turns into plaque called amyloid fibrils, though the exact pathways of these reactions remain unclear. An early section of the process of formation of fibrils is two small protein fragments of amyloid beta coming together within a nucleus of a cell to form a fibril. Lund University’s study suggests that fibrils have a catalytic surface, allowing reactions to happen quicker while touching them, creating new nuclei which in turn aid the proliferation of more fibrils, causing exponential growth in plaque formation. After a small but crucial amount of amyloid fibrils are created, more immediately surface to begin a self-perpetuating process key to understanding Alzheimer’s. These findings dash what was previously believed; that fibrils formed in single nuclei reactions as a uniform process. More profound perhaps than the catalytic surface is the discovery that this aggregation of amyloid fibrils creates toxic oligomers, small groups of proteins. These oligomers have been identified as neurotoxins that play a significant part in cell-death.
It is the hope of Professor Linse that new medicines targeted at shutting down the catalyzation of amyloid fibrils and the resultant neurotoxins can slow or even stop the progression of the disease. For now, it is heartening that ongoing Alzheimer’s research is yielding new information about the degenerative disease and possible ways to fight its progression.References:
1) S. I. A. Cohen, S. Linse, L. M. Luheshi, E. Hellstrand, D. A. White, L. Rajah, D. E. Otzen, M. Vendruscolo, C. M. Dobson, T. P. J. Knowles. Proliferation of amyloid- 42 aggregates occurs through a secondary nucleation mechanism. Proceedings of the National Academy of Sciences, 2013; DOI: 10.1073/pnas.1218402110
2) Lund University (2013, May 29). Molecular chain reaction in Alzheimer’s disease. ScienceDaily. Retrieved May 30, 2013, from http://www.sciencedaily.com /releases/2013/05/
Keywords: Alzheimer’s disease, Amyloid Beta ProteinArticle By:
Lauren Horne (edited by Emma Henson)Roskamp Institute is devoted to find cure for brain related disorders. Its a non-profit research institute located at Sarasota, Florida. Dr. Michael Mullan is the head and CEO of the Roskamp Institute.
Recently, there has been increasing interest in the role of sports head injuries and subsequent cognitive decline. For instance, American football players are being scrutinized more closely because of new research suggesting close links between repeated concussion and decline in cognitive abilities.
Complaints by professional players are now being taken seriously, as associations all over the country begin to take action. “I’ve had times where I walked up to the line, where I know the play, but don’t know what to do.”
– Oakland Raiders tight end Tony Stewart “I’ve known of players hiding concussions..Sometimes players aren’t real sure. They hit their head, they get a little cuckoo for a little while. It happens all the time.”
– Kansas City Chiefs center Rudy Niswanger
Over the last three decades, there has been much work on the relationship between head injury (usually single head injury) and Alzheimer's disease (AD) and other dementias. Many well designed, population based studies have suggested a link between head injury and the development of AD and other dementias. However, there are many discrepancies between these studies and the risk attributed to head injury has varied widely between them. Several key factors are often examined in these studies to try to understand better the relationship between traumatic brain injury (TBI) and AD.
The following areas have been studied extensively:
1. The Gender Effect
: Despite the many case control and cohort studies, none have shown an increased risk for AD after TBI for women. Although many TBI studies focus on the male population who are more at risk (for instance, in contact sports or in the military) the finding that women are at no increased risk of AD after TBI suggests that there may be a protective effect of female hormones against the development of AD after head injury.
2. The degree of injury and subsequent development of AD or related disorders
: Few studies have adequately assessed the degree of injury and so information in this area is limited but, the studies that have, in general, suggest that more moderate or severe injuries predispose to dementia later in life. For instance, one study divided TBI into mild, moderate, and severe categories: injuries with loss of consciousness (LOC) or post-traumatic amnesia (PTA) of less than 30 minutes (mild); of more than 30 minutes but less than 24 hours (moderate); and of more than 24 hours (severe). Most studies suggested moderate and severe disease is more related to AD and that full recovery of cognitive loss can be regained after mild TBI.
3. Time of injury to the development of subsequent dementia
: This relationship has been studied in large populations and there are good data to suggest that TBI in old age is associated with worsening of outcome compared to TBI at a younger age. Nevertheless, even individuals that have TBI in early adulthood (if the injury is severe enough) are at increased risk of AD and other dementias as many as five decades later.
One key question is how the brain "remembers" the injury for so many years and why there may be no signs of cognitive impairment soon after the injury for many decades until AD onsets. The question of the molecular underpinnings of TBI and how the brain continues to register that an injury has occurred is an area of intense study.
One such candidate for molecular memory is amyloid. The amyloid molecule is increased in the brains of AD sufferers and occurs early in the pathological sequence that leads to full-blown AD. Most studies show that only about one-third of TBI victims have amyloid at autopsy. Although amyloid is produced acutely after TBI, much of that amyloid does not stay in the brain but is degraded in the weeks and months following injury.
Another pathological molecule central to the AD process is tau. Tau protein is formed when neurons die. Although tau has been implicated in TBI, again, there are inconsistent data between studies -- some showing no increased involvement of tau while others show hyperphosphorylation and/or aggregation of tau. More recently in repetitive head injury (for instance, those occurring in American football) tau has been implicated as it has been seen particularly around blood vessels in the brain.
Whatever the ultimate underlying cause of the link between TBI and the subsequent development of AD, we can expect that once those links are fully uncovered, they will become new targets for the prevention of AD following TBI.
One other area that deserves attention is the genetic risk for poor recovery after TBI and subsequent risk for AD. Although it is generally accepted that APOE4 is a risk factor for AD, some studies of head injury have been equivocal in demonstrating that APOE4 acts synergistically with TBI to increase risk for AD.
However, given the plethora of data on the negative roles of APOE4 in the brain after TBI, it is safe to assume that individuals who carry the E4 are most probably at greater risk for developing AD than those who do not. It has been advocated that those individuals carrying an APOE4 allele should not engage in professions or pastimes with increased risk of TBI.
Much more work is needed in this area; but, at this stage, as a precaution, this is probably a position that can be easily endorsed.Dr. Michael Mullan is the president of Sci-Brain. A company providing personalized program to reduce risk of Alzheimer's disease and improve your Brain Health.
Scientists at Cambridge’s Department of Chemistry have been able to construct a detailed map that shows how the formation of proteins in the brain can lead to a build-up so massive that it can lead to the development of numerous brain-damaging diseases, chief among them is Alzheimer’s. In 2010, the Alzheimer’s Research Trust found that with dementia alone, it cost the UK economy E23 billion, way more than cancer and heart disease combined cost.
Normally, proteins are made up of chemical building blocks known as amino acids, which are joined together in a code ordered by our DNA. New proteins appear as long, thin strips, which are then intricately folded to properly carry out their designated biological function. However, there are points at which the protein can ‘misfold,’ or unfold and get tangled together with other newly-made proteins. The tangles stick to one another until they number in the millions, known as amyloid fibrils, and they start the huge deposits of proteins known as plaque, which are so huge that they are insoluble.
When the level of plaque in the brain reaches a critical level, a chain reaction is set off, and new focal points of tendrils form. From these tendrils, a smaller number of proteins, known as toxic oligomers, can easily diffuse through membranes, effectively killing neurons, causing memory loss, and other dementia symptoms.
This new groundbreaking information required scientists to come together, using kinetic experiments with a framework of theory. Master equations, more commonly used in the fields of chemistry and physics, aided researchers in their efforts to better understand a disease such as Alzheimer’s, and how better to fight it.
By Lauren Horne
University of Cambridge (2013, May 20). Molecular trigger for Alzheimer's disease identified. ScienceDaily. Retrieved May 22, 2013,
Samuel I. A. Cohen, Sara Linse, Leila M. Luheshi, Erik Hellstrand, Duncan A. White, Luke Rajah, Daniel E. Otzen, Michele Vendruscolo, Christopher M. Dobson, and Tuomas P. J. Knowles. Proliferation of amyloid-β42 aggregates occurs through a secondary nucleation mechanism. Proceedings of the National Academy of Sciences, 2013; DOI: 10.1073/pnas.1218402110
A new study by researchers at the Albert Einstein School of Medicine dramatically underscores the potential role of the NF-kB protein in aging. NF-kB is a master protein which controls many inflammatory chemicals throughout the body. Researchers at the Roskamp Institute have studied NF-kB for many years as a potential way of controlling chronic inflammation which accompanies aging and underlies conditions such as Alzheimer’s disease. This new study points to a part of the brain as regulating the aging process. The current view of aging generally suggests that enzymes, DNA, proteins and other constituents of the body essentially “wear out” with age, accumulating damage due to environmental insults until they no longer function properly. This new study suggests something quite different, namely that a part of the brain called the Hypothalamus deliberately induces aging throughout the body. It has been suggested that one reason why the brain might take such drastic action is to inhibit reproduction past a certain age. This suggestion is highly speculative at this stage, but the data offered by the Albert Einstein researchers suggests that, with age, increased NF-kB activity triggers degeneration in both the brain and other areas of the body. The researchers showed that as mice aged, they increasingly expressed NF-kB in the part of the brain that is normally responsible for the production of reproductive and growth hormones. The researchers artificially manipulated NF-kB activity using genetic techniques and showed that reducing NF-kB activity was associated with better performance in cognitive tests, greater muscle strength and greater bone mass and skin thickness. Conversely, exacerbation of NF-kB activity increased all of these peripheral signs of aging, as well as reducing cognitive abilities. Furthermore the research suggested that microglia (the inflammatory cells resident in the brain) are the originators of the NF-kB activity and this spreads to nearby neurons, including those responsible for growth and reproductive hormones. These findings are of direct significance to work at the Roskamp Institute as researchers there have shown that increased NF-kB collates strongly with Alzheimer’s pathology and pathology of other central nervous system disorders. Moreover, they have worked extensively on ways to reduce NF-kB activation, particularly using the naturally occurring compound Anatabine. Roskamp Institute researchers have shown in multiple preclinical studies of neuroinflammation (such as Alzheimer's, traumatic brain injury and Multiple Sclerosis) that Anatabine (supplied by RockCreek Pharmaceuticals) has potent anti-inflammatory properties. This new finding suggests that NFKB inhibitors might also have a role in decelerating aging. In fact, preliminary studies at the Roskamp Institute suggest that mortality in mice with Alzheimer pathology is reduced by Anatabine treatment. Additional studies are needed to clarify whether Anatabine might reduce the Hypothalamic inflammation and increase the release of hormones that oppose aging.
Dr. Michael Mullan M.D., Ph.D
President & CEO
Preliminary results of the treatment of a mouse model of Multiple Sclerosis with Anatabine. Roskamp Institute scientists Dr. Michael Mullan and Dr. Daniel Paris used a standard model of MS (multiple sclerosis) to assess the effects of anatabine in this disease characterized by very high levels of inflammation in the brain. The mouse model known as EAE (experimental autoimmune enchephalomyelitis) is characterized by high levels of circulating antibodies to the fatty sheaths that surround nerve fibers. The model is induced by vaccinating mice with myelin which induces an autoimmune reaction. As a consequence there is a devastating inflammatory process in the brain which has the effect of destroying neurons and causing progressive paralysis. In this regard the disease model looks very similar to that which occurs in human MS. Treatment with anatabine resulted in a dramatic reduction in the rate of paralysis of hind limbs.
Dr. John L. Faessel
ON THE MARKET
Commentary and InsightsReport from the Harvard Club Meeting
Dr. Mullan and the Roskamp Institute have conducted research relating to the company's anatabine compound for a number of years. Dr. Mullan first spoke to and thoroughly reprised with the supporting graphs the research that the Roskamp Institute has performed, essentially what he presented last June at a Roskamp Institute meeting. Mullan again played the videos that showed standard
Alzheimer's-afflicted mice beginning not only to remember again, but becoming able to add critical new information to the cognitive equation and, thus, to change behavior so as even to improve their lot after the administration of anatabine. That's impossible for a "demented" mouse. A split screen video depicted for comparison a mouse fully impaired with the disease. He went on to say that CRP* levels also fell 50% in these test animals, indicating less inflammation. Dr. Mullan called the research "profound." For more details of the articles please visit: http://seekingalpha.com/instablog/576542-dr-john-faessel/618891-report-from-the-harvard-club-meeting-re-cigx-snowballing-progress