Find updates on the work of our researchers here, as well as news about recent advances in Alzheimer's science, funding and awareness.

Targeting Amyloid Oligomers in Alzheimer's Disease

By Charles Glabe, Ph.D. University of California at Irvine
Professor, Molecular Biology and Biochemistry, School of Biological Sciences.

The current treatments for AD target the disease symptoms and to prevent or cure AD, new treatments are needed that target the causes of the disease.  Aß oligomers are a leading candidate for causing AD, so it makes sense to develop strategies to prevent their formation, promote their elimination or inhibit their toxic activity.


Alzheimer’s disease (AD) is the most wide spread and debilitating disease that robs otherwise healthy individuals of essential functions, such as memory and cognitive ability.  One of the critical aspects of AD is accumulation of misfolded proteins as deposits in regions of the brain involved in learning and memory that are known by the general term “amyloid”.  One of the curious aspects of amyloid is that it also accumulates in other degenerative diseases associated with aging, like Parkinson’s and Huntington’s diseases and type II diabetes.  In AD, the amyloid deposits are primarily made up of a small protein known as “amyloid beta”, or Aß, while in other degenerative diseases a different type of protein forms the amyloid.  In most of these diseases, mutations in the amyloid forming protein promote the misfolding of the protein and are associated with rare inherited forms of disease, providing strong evidence that amyloid formation is closely linked to the disease.

Amyloids grow into long, thin fibrils by the addition of misfolded proteins on to the ends much like the addition of a single Lego block on to a stack.  Proteins are linear strands of amino acids that fold into complex globular shapes that are critical for the proteins function.  In order for a normal protein to form an amyloid fibril, it must undergo a change in its original shape from a globular form to an unwound abnormal shape that allows it’s self-assembly with other misfolded protein strands like Lego blocks.  This assembly can go on infinitely, so that each amyloid fibril may contain a million or more individual subunits or blocks.  
Although amyloid accumulation is a key feature of AD, it also presented an enigma because the accumulation of insoluble amyloid fibril deposits is poorly correlated with dementia.  Some cognitively normal individuals were found to have the same amount of insoluble amyloid deposits as AD patients, indicating that these deposits are not always associated with disease.  Similarly, other AD patients have been observed with relatively little of the insoluble amyloid deposits.  These observations refocused research away from the insoluble amyloid deposits to other types of amyloid aggregates known as “oligomers”.  More recent research in amyloid aggregation has discovered that the amyloid formation pathway also includes smaller aggregates, or oligomers and these oligomers have a different shape or conformation of the protein than that found in amyloid fibrils.  Like Duplo blocks and Lego blocks, the oligomer conformation does not co-assemble with the fibril building blocks, but rather only supports the self-assembly of small aggregates of about 3-24 individual peptide strands.  Amyloid oligomers have been observed for AD and other amyloid-related degenerative diseases.  There is increasing evidence that these small oligomers, rather than the long fibrils, are the primary toxic or pathogenic species that cause all of these degenerative diseases.  Oligomers are more toxic to cells and their presence correlates better with disease than the fibrils.  Determination of the structures of these toxic oligomers, what they do to cause disease and how we may prevent their toxic activity are the primary objectives of Cure Alzheimer’s Fund Research Consortium Collaborative.

The Cure Alzheimer's Fund Research Consortium Collaborative consists of five of the members of the Research Consortium and a member of the Cure Alzheimer’s Fund Science Advisory Board. This highly innovative collaborative project investigates critical aspects of amyloid oligomers in AD.  The project is in it’s second year of funding.

For a full summary of the funded researchers and their projects, please visit our website and see the
The laboratories of Dr. Charles Glabe, University of California at Irvine, and Dr. Virginia Lee, University of Pennsylvania, are making monoclonal antibodies that specifically recognize distinct types of amyloid oligomers.  These properties of specific antibodies are very important for the development of passive immunotherapy and vaccines for AD, which is one of the leading strategies for therapeutic development (see “A Vaccine for Alzheimer’s disease?” by Dr. David Holtzman in the Fall 2006 quarterly report for more details about vaccine development.)  Oligomer specific monoclonal antibodies are also useful for screening for drugs that prevent oligomer formation and as diagnostic agents.  Although diagnostic agents may not seem to have much utility until better treatments are available for AD, they are critical for  developing new therapies by allowing clinicians to recruit more homogeneous populations of individuals at risk for disease onset for human clinical trials.  They are also crucial for drug development by allowing pharmaceutical companies to directly evaluate the effectiveness of drugs that target amyloid oligomers.

Drs. Rudy Tanzi and Robert Moir of Massachusetts General Hospital/Harvard Medical School are working on the discovery of drugs that prevent the formation of a novel type of amyloid oligomer knows as “cross-linked amyloid protein species” (CAPS).  These results suggest that immunization with anti-CAPS antibodies and drugs that prevent the formation of CAPS might provide therapeutic benefit for AD.  Drs. Tanzi and Moir are also providing CAPS to other members of the Cure Alzheimer Fund research consortium for analysis of their immunological properties and toxic activity.

Drs. Sangram Sisodia, University of Chicago, and Sam Gandy of Mt. Sinai Medical School are working on amyloid oligomers in transgenic mouse models of AD.  Dr. Sisodia’s laboratory is working on Aß*56, a particular type of amyloid oligomer that is closely associated with the development of cognitive dysfunction in Tg2576 mice.  Dr. Sisodia’s lab focuses on the molecular analysis of Aß*56 structure and function and how exercise may impact the formation of Aß oligomers.  Dr. Gandy’s laboratory is developing new transgenic mouse models of AD that have different types of amyloid oligomers and these animal models will be shared with other members of the consortium.  These animal models are very important for development of new therapeutics because they provide a means of determining the pathological significance of amyloid oligomers and they can be used for testing new drugs and vaccines for effectiveness.

Drs. Paul Greengard of The Rockefeller University, David Holtzman of Washington University at St. Louis and Dr. Tae-Wan Kim of Columbia University Medical Center are investigating the relationship between oligomers and neuronal synapse function.  Synapses are critical for neuronal communication in learning and memory and there is evidence that synaptic loss and dysfunction play a role in AD.

Why target Aß oligomers?

The current treatments for AD target the disease symptoms and to prevent or cure AD, new treatments are needed that target the causes of the disease.  Aß oligomers are a leading candidate for causing AD, so it makes sense to develop strategies to prevent their formation, promote their elimination or inhibit their toxic activity.  Vaccination against Aß has shown considerable promise in human clinical trials, but one of the hurdles that must be overcome in order to develop an effective vaccine is to develop vaccines that lack undesirable inflammatory side effects.  Vaccines that specifically target the misfolded conformation specific to amyloid oligomers may eliminate oligomers or block their toxicity and overcome these side effects.  Since the structures recognized by the antibodies are specific for the disease state and do not recognize the normal, non-disease related protein structures, vaccination against the oligomeric conformation may be less likely to cause inflammatory complications. Conformation dependent monoclonal antibodies may be more effective therapeutic agents because they bind only to the pathological oligomers that are present at low concentrations and will not bind to amyloid plaques.  Similarly, drugs that specifically target Aß oligomer formation or toxicity may be more effective because lower concentrations of drugs may be needed to achieve a therapeutic benefit and they may have lower side effects as a consequence.  The Cure Alzheimer’s Fund Research Consortium Collaborative has a broad and integrated research program that is focused on developing therapeutic agents that prevent or cure AD by targeting the cause of AD.


Research Update: May 2008

Two papers, supported in part by Cure Alzheimer’s Fund,  have just been published in two leading research journals. The findings show links between certain kinds of anesthesia and pathological features of Alzheimer’s disease.

Alzheimer's Drugs on the Horizon

Part I. Disease-Modifying Drugs Targeting A-beta

By Dr. Rudolph Tanzi, Massachusetts General Hospital

Recent developments regarding drugs aimed at treating and preventing Alzheimer’s disease (AD) by targeting the neurotoxic peptide Abeta.

This article, the first in a series of pieces reviewing promising new AD drugs in development, focuses on novel therapies based on the “A-beta Hypothesis of AD”.  These drugs are aimed at retarding disease progression by curbing the accumulation of A-beta, and particularly, A-beta42, in the brain.

The Basics of Drug Discovery

The path from research discovery to drug development can be a long one. Current estimates target the time for an Alzheimer’s drug to get to market at around 12 years. However, with new technological advances in such areas as genetics, we are optimistic
that scientific opportunities have never been greater to reduce this timeline significantly.
In his article, Dr. Tanzi highlights some of the promising developments on the immediate horizon. We’ve compiled the following background information on the drug development process in the United States to explain the progress of a drug to market.


Novel Therapies for Alzheimer's Disease Based on Early Onset Genes

Supplemental Information for Senate Special Committee on Aging Hearing


Alzheimer’s disease (AD), the most common form of dementia, was first described roughly one hundred years ago in Bavaria by Dr. Alois Alzheimer in his presentation of an early-onset (<60 years) case.  AD is a progressive and fatal neurodegenerative disease that impairs memory and overall cognition. There are more than 5 million documented patients according to best estimates, with some experts suggesting that may be only 20% of the total number actually affected. The number of new cases grows by more than 10% per year. Alzheimer’s disease is the seventh leading cause of death for people of all ages, the fifth leading cause of death in people age 65 and older, and is the only one of the major diseases (heart disease, breast and prostate cancer and stroke) to be increasing in mortality; up almost 33% from 2002 to 2004. Medicare expenditures for Alzheimer’s and other dementias in 2005 were $91 billion; this total is projected to increase to $160 billion by 2010. State and federal Medicaid spending for nursing home care for people with Alzheimer’s and other dementias was estimated at $21 billion in 2005, and is projected to increase to $24 billion by 2010. Given these estimates and no significant containment or decrease in Alzheimer’s, Medicaid and Medicare expenses for Alzheimer’s and related dementias will be approximately $184 billion by 2010, or approximately 27% of the entire combined anticipated expenditure for Medicare and Medicaid in 2010.

The Search for New Ways to Treat Alzheimer's Disease

By John R. Cirrito, Ph.D., and David M. Holtzman, M.D.
Microdialysis Core Facility, Department of Neurology, Hope Center for Neurological Diseases, Washington University, St. Louis, MO

A major contributing factor in Alzheimer’s disease is the elevation of a protein called amyloid-β, or Aβ. Since high levels of Aβ play a role in the disease, many research groups around the world are developing therapies designed to lower the levels of this protein. With the help of Cure Alzheimer’s Fund, our group initiated an ambitious project to discover new drugs that reduce Aβ levels. Our approach is to test drugs in living animals (mice). While this process is time-consuming, it enables us to discover entirely new classes of compounds that traditional drug screening methods typically might overlook.

Alzheimer's Genome Project Pre-publication Summary


Alzheimer’s disease (AD) is the most common cause of dementia in the elderly and a burgeoning unmet medical need that will only worsen as the average lifespan continues to increase. The prevalence of AD increases with every decade after the age of 60 and ~ 20% of the population can expect to get this devastating disease in their lifetime given the current average lifespan of  ~78 years. AD is strongly influenced by inherited factors. In fact, after age, the greatest risk factor for AD is family history. Studies of several thousand pairs of twins have revealed that at least 80% of Alzheimer’s disease involves the inheritance of risk-conferring gene defects—either gene mutations that directly cause the disease, or gene variants that increase susceptibility. To date, we know the identity of four AD genes. Over the last two decades, studies of these four genes, and particularly the three early-onset AD genes co-discovered by Cure Alzheimer’s Fund Research Consortium Chairperson, Dr. Rudy Tanzi, have guided virtually all laboratory research aimed at understanding AD and developing novel therapeutics. As invaluable as the known AD genes have been to solving the mystery of AD and guiding new therapeutic interventions, these four genes account for only 30% of the inheritance of Alzheimer’s disease. While the three early onset AD genes (APP,PSEN1, and PSEN2) account for roughly half of familial early-onset AD, for the most common late-onset (>60 years) form of AD, only one gene has thus far been established to increase susceptibility. This gene is known as the apolipoprotein E (APOE) gene. Since the discovery of the association between AD risk and the E4 variant of the APOE gene, increasing evidence indicates that this variant is neither sufficient nor necessary to cause the disease. We know that APOE works together with other genes to influence one’s inherited risk for AD. To date, the identity of the additional AD genes, which account for 70% of the genetic basis of AD, has remained unknown.

The Cure Alzheimer's Fund National Alzheimer's Disease Research Strategy

Prepared by:

Rudolph E. Tanzi, Ph.D.
Chairperson, Cure Alzheimer’s Fund Research Consortium
Joseph P. and Rose F. Kennedy Professor of Neurology
Harvard Medical School,
Director, Genetics and Aging Research Unit,
MassGeneral Institute for Neurodegenerative Disease
Department of Neurology
Massachusetts General Hospital
114 16th Street
Charletown, MA 02129

Timothy W. Armour
President and CEO
Cure Alzheimer’s Fund
34 Washington Street Suite 300
Wellesly Hills, MA 02481

The overarching goal of a national AD research strategy is to reach a cure most efficiently by accelerating studies aimed at identifying and characterizing all of the genes that influence susceptibility to AD, placing highest priority on those that will most readily lead to effective therapeutics for the treatment and prevention of AD.

Over the next decade, the influx of roughly 50 billion dollars into AD research should allow us by 2020 to identify all of the genes involved in AD susceptibility, and to arrive at a cure based largely on prevention.

Research Papers Supported By Cure Alzheimer's Fund

This is a list of papers funded by Cure Alzheimer's Fund. It also includes “layperson” descriptions of each paper. We are grateful to the researchers for translating the work of their papers into language more accessible to most of us than the more precise technical language useful to them and their peers.

We thank all the researchers and lab personnel for their dedication and commitment to the common mission of ending this disease, and we congratulate all of them for the important work reflected in these papers.

We also are grateful to all of those who literally made this work possible. Without those of you who have supported Cure Alzheimer’s Fund projects through your generosity, these papers and the forward momentum they represent would not exist.


Major Findings Linking New Genes to Alzheimer's Disease Announced in Publication of Four Papers

Four papers published this fall in leading science journals refer to the identification of new genes that confer risk for, or protection against, Alzheimer’s disease.