Moving beyond anti-amyloid therapy for the prevention and treatment of Alzheimer's disease

Amyloid β: one of three danger-associated molecules that are secondary inducers of the proinflammatory cytokines that mediate Alzheimer's disease

This review concerns how the primary inflammation preceding the generation of certain key damage-associated molecular patterns (DAMPs) arises in Alzheimer's disease (AD). In doing so, it places soluble amyloid β (Aβ), a protein hitherto considered as a primary initiator of AD, in a novel perspective. We note here that increased soluble Aβ is one of the proinflammatory cytokine-induced DAMPs recognized by at least one of the toll-like receptors on and in various cell types. Moreover, Aβ is best regarded as belonging to a class of DAMPs, as do the S100 proteins and HMBG1, that further exacerbate production of these same proinflammatory cytokines, which are already enhanced, and induces them further. Moreover, variation in levels of other DAMPs of this same class in AD may explain why normal elderly patients can exhibit high Aβ plaque levels, and why removing Aβ or its plaque does not retard disease progression. It may also explain why mouse transgenic models, having been designed to generate high Aβ, can be treated successfully by this approach.

Do We Try Mending Humpty Dumpty or Prevent His Fall? An Alzheimer's Disease Dilemma

In the popular nursery rhyme, Humpty Dumpty's great fall and the inability to put him together again has been used to demonstrate the second law of thermodynamics. An oversimplification of this law states that all things in the universe tend to move from order to disorder, an occurrence that can be applied allegorically to the development and clinical outcome of Alzheimer's disease (AD). An important argument relevant to the future use of resources and primary focus of AD research arises from the question, do we make it a priority to mend the shattered brain of AD patients or attempt to prevent the brain from shattering? If the former approach continues to be the priority it has become, how exactly do we mend the irreparable neuronal loss and associated cognitive failure in advanced cases of AD? Or, must we change direction and make prevention the primary goal of AD research? The latter approach would identify asymptomatic or mildly symptomatic patients with high risk of developing dementia by means of establishing multidisciplinary heart-brain clinics that would provide either close observation or a tailored therapeutic intervention. This is an important challenge that needs to be achieved if the AD incidence, societal costs and suffering, is to be significantly reduced.