Nutritional Deficiencies in Alzheimer’s Disease

Impact of AD on our Society

The prevalence of AD doubles
 for every decade beyond 65…

What is the most difficult hurdle faced
in developing a treatment for AD?

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Areas to cover...

Areas to cover...

Basics of a Neuron

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The cytoskeleton consists of
polymers & “associated” proteins
that cross-link the polymers

Binding of associated proteins to microtubules is regulated by phosphorylation

Phosphorylation of tau and its potential role
in degeneration of neurons

PHFs cannot be transported into axons and instead clog the cell body

Another “player”
in AD…
 ß-amyloid (“ßA”)

bA is neurotoxic to neurons in culture

bA induces tau phosphorylation

bA treatment induces apoptosis

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Are we simply living too long?

Current studies suggest that Alzheimer’s disease may be a disorder of Oxidative Stress

What is oxidative stress?

Why are neurons uniquely susceptible to
metabolic problems such as oxidative stress?

Some Details...

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MAP kinase regulates all major effects
of b-amyloid on cultured neurons

MAP kinase mediates
Abeta-induced apoptosis

MAP kinase activates a neuronal calcium channel
(the “L voltage-sensitive calcium channel”) following bA exposure

MAP kinase induces sustained channel activity...

How can we block this cascade?

Three major religions that worship neurodegeneration in AD...

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Phospho-tau is
induced in
cortical neurons
by ßA

Reactive oxygen species are prominent in degenerating neurons following ßA exposure

Preventing ROS accumulation by treatment with vitamin E promotes survival in culture

Some Details...

If we treat with vitamin E...

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Reduced Folate Levels in Neurodegenerative Disorders

“Serum folate and the severity of atrophy of the neocortex in Alzheimer’s disease:  findings from the Nun study”
(Snowdon et al., 2000 Am J Clin Nutr 71:993-8)

How do folate levels modulate neuronal health?

Folate deficiency induces accumulation of phospho-tau

“Long-term” folate deprivation induces apoptosis

Efficacy of vitamin E & folate against ROS in mouse brain

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Folate regulates Abeta-induced ROS generation

Folate deficiency increases homocysteine (HC)

Homocysteine FYI

Homocysteine FYI cont’d...

HC potentiates Abeta-induced cytosolic calcium accumulation

HC potentiates Abeta-induced apoptosis: Role of oxidative stress

HC sequentially activates calcium channels

A familial AD linkage for HC...

More on the
pathological consequences
of folate deprivation later,
in relation to drug treatments...

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Beneficial Effects of
Acetyl-L-Carnitine in AD

ALCAR prevents apoptosis following Abeta exposure

Abeta depletes neuronal energy; ALCAR restores energy & minimizes neurodegeneration

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“Nutrition-based”
Combinatorial approach...

Efficacy of our “nutrition-based” combinatorial approach

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Methionine Cycle and Neurodegeneration

Pertubations of the Methionine Cycle:
Consequences of Folate/B12 Deficiency

Compensation for Folate/B12 Deficiency:
Treatment with 3-DZA

DZA attenutates ROS generation following folate deprivation

Compensation for Folate/B12 Deficiency:
Treatment with NAC

N-acetyl-L-cysteine inhibits ROS formation in neurons

Delayed application of NAC is effective, while that of vitamin E is not

Compensation for Folate/B12 Deficiency:
Treatment with SAM

Watch this space
 for exciting results
     on the effects of SAM!!

“Drug-based”
Combinatorial approach...

Combined treatment with DZA, SAM & NAC

Why not supplement with methionine?

Loose ends, plans, etc.

Lots of mice...

Thank you to...