Maverick
05-11-2009, 04:54 PM
Did you even go to the link? I'm pasting the text below.
You people are incredible. This will be more or less unreadable but I'll post it just to show you it exists. There is literally not a more innocuous place for me to post a document. I had no idea you could run a forum that prohibits hyperlinking.
Page 1
Reinterpretation of known pathological mechanisms in Amyotrophic Lateral Sclerosis
Background
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder involving the
death of both the upper and lower motor neurons. Victims of ALS gradually lose control of their
skeletal muscles, with the notable exceptions of the sphincter and ocular muscles. The process
is believed to be caused by excitoxicity – that is, the inappropriate depolarization of the motor
neurons, in the absence of conscious attempt at movement. Excitotoxicity results in premature
apoptosis of the motor neurons, with deleterious effects on the muscles they innervate. As a
result of disuse, skeletal muscles atrophy and are susceptible to fasciculation. Late-stage ALS
is thus unmistakable. Patients typically die when the muscles required for respiration fail; this
occurs 2-5 years after diagnosis (NIH, 2009).
Diagnosis of ALS is typically a diagnosis by exclusion. Clinicians must rule out other possible
causes of neurodegeneration or paralysis, such as lead poisoning, non-neuronal myopathy, and
multiple sclerosis. As approximately 20% of ALS cases are classified as familial, having a
family member who suffers from ALS increases the likelihood that ALS symptoms do indeed
indicate ALS. The description of these cases as “familial,” however, should not be interpreted to
mean that they are genetic. Only about 2% of all ALS cases can be attributed to a genetic
defect (Mayo clinic, 2009).
The study of ALS is complicated by the fact that only 2 out of 100,000 or so people will go on to
develop it. It is possible to induce ALS-like symptoms in mice by mutating the SOD1 gene, but
it must be remembered that this mutation is orthologous to only a very, very small proportion of
the human population. Interestingly, SOD1 knockouts do not exhibit the ALS – like symptoms of
the mutant SOD1 mice, and this has led to much speculation about the toxic “gain of function” of
the mutant protein. In recent years, however, focus has shifted from the gene itself towards the
system of which it is a constituent – the cell’s antioxidant defense system.
The Antioxidant Defense System
The function of the antioxidant defense system is to neutralize highly reactive by-products of
respiration, known as reactive oxygen species (ROS).The cell’s principle defense against ROS
is its antioxidant enzymes, superoxide dismutase, catalase, and glutathione peroxidase.
Superoxide dismutase reduces superoxide to hydrogen peroxide, which is further reduced to
water and oxygen (O
2
) by catalase and to water by glutathione peroxidase. Glutathione
peroxidase is itself modified in the process, but is restored by the activity of glutathione
reductase.
The catalytic activity of the antioxidant enzymes might be sufficient, were there an antioxidant
enzyme for every ROS. Such is not the case. One ROS for which the cell has no dedicated
Page 2
enzyme is the hydroxyl radical, create via the catalytic activity of iron in the presence of
superoxide. The hydroxyl radical is neutralized by any of the non-enzymatic antioxidants, such
as vitamins C and E, which readily give up an electron.
Zinc, copper, and selenium are key components of the antioxidant enzymes, and copper
deficiency has been suggested as one cause of neurodegenerative diseases (Hartmann &
Evenson, 1992). Copper is also essential for metabolizing iron, as in the formation of the heme
groups of hemoglobin; thus, a copper deficiency might manifest itself as an excess of iron,
resulting in increased production of ROS via the Fenton reaction. Copper deficiency is known to
cause neurological and other dysfunctions in livestock (Kumar N, Gross JB, & Ahlskog JE) and
has been mistaken for ALS in some human patients (Hartmann & Evenson,1992).
Oxidative Stress
Insufficient activity of the antioxidant defense system, whether due to an excess of ROS or a
deficiency of antioxidant nutrients, results in a state of oxidative stress. Oxidative stress refers
to the general dysfunction that arises when ROS damage cellular proteins and nucleic acids. In
fact, damage by ROS may be the principle cause of protein damage, underlying or superseding
some of the other purported causes. For example, proteins may be damaged via glycosylation,
and this glycosylation is said to be due to abnormally high concentrations of glucose. However,
the same protein damage can be induced much faster by high concentrations of the
polyunsaturated fatty acids (PUFAs) (Fu et. al, 1996). Although the PUFAs are by no means
inactive in the absence of oxygen, they break down into their toxic end products much more
rapidly under the influence of the ROS.
It would then appear that excessive production of ROS is sufficient to explain much of the
pathophysiology that cannot be attributed to some other mischief, such as a toxin or infectious
agent. For this reason “oxidative stress” is becoming an increasingly popular term, and not just
in relation to the neurodegenerative diseases. Heart disease, diabetes, and preeclampsia are
all now associated with oxidative stress, and this association is laying the groundwork for a
unified model of the pathological mechanisms underlying different diseases. Oxidative stress is
associated closely with the mitochondria, and this has led to the idea of a “respiratory defect.”
This term used to be popular in the study of cancer, which can be viewed as approximately the
opposite of ALS: whereas metabolically compromised ALS motor neurons die, metabolically
compromised cancer cells go glycolytic.
Evidence of oxidative damage in ALS is found in conventional markers of oxidative damage to
DNA, proteins, and lipids, all of which are elevated in the neuronal or glial cells of ALS patients.
When ROS interact with the PUFA’s, they generate highly reactive end-products, including
malondialdehyde and 4-hydroxynonal. Like the hydroxyl radical, these end-products have no
enzyme to defuse them, and so they amplify the effects of ROS, causing oxidative damage and
depleting antioxidants, particularly vitamin E. The modification of DNA by ROS and lipid
peroxides could in theory cause permanent mutations and thus manifest itself as aberrant
proteins, but in practice this is prevented by the activation of a DNA repair system, poly(ADP-
ribse)polymerase or PARP. However, PARP activation is energetically expensive, and is
Page 3
associated with cell death in motor neuron cell lines (Robberecht et al., 2000). Moreover, motor
and other neurons in the brains of ALS patients have been shown to express PARP (Kim et al.,
2004). This is consistent with the finding that some 50% of all ALS patients exhibit some
degree of cognitive dysfunction, as opposed to 5% of controls (Ringholz, 2005). This finding is
important, as it indicates that pathology in ALS is systemic, rather than specific to motor
neurons. It is simply the motor neurons that are affected more severely and earlier.
The deleterious effects of ROS are not mediated through PARP activation alone. Before PARP
mediated cell death, ROS damage proteins and may facilitate PARP activation or induce
apoptosis independently of the PARP system. Either way, one of the primary toxic mechanisms
is energy depletion. Damaged proteins must be replaced or repaired, at a high energy cost to
the cell. Protein aggregates, such as lipofuscin (the age pigment) or the amyloid plaques of
Alzheimers, are particularly difficult to deal with. Similar aggregates have been observed in
cells of ALS patients, and these aggregates are ubuiquinated, that is, tagged for degradation.
That the cell will have to make new copies of these proteins represents one additional cost, but
the degradation itself has a cost as well, because ubiquitin binding itself is energy dependent
(Shaw, 2000). Adaptation to the additional energy demand requires greater mitochondrial
output, but this results in a concomitant increase in the production of ROS.
There is also strong evidence to suggest that oxidative damage is instrumental, as opposed to
incidental, in the pathogenesis of ALS, as antioxidant nutrients postpone or prevent
development of the disease. This has been verified in the mouse model of ALS, and
epidemiological data indicate that it is probably true of humans as well (Ascherio et al., 2005).
Vitamin E represents a particularly promising therapy, particularly considering how narrow its
conception and use. In the first place, the function of vitamin E should not be reduced to an
antioxidant even though that is certainly an important function in relation to the oxidative stress
of ALS. Just as the PUFAs have a range of endocrine-like effects, vitamin E probably has
effects mediated through its interaction with other signaling factors (Peat, 2006). In the second
place, vitamin E exists in many forms, of which the most effective has not been determined and
may not have been studied or sold to any significant degree (Chen. et al., 2002, Sen, Khanna, &
Roy, 2004).
At least a couple of retrospective studies have found a protective effect of the PUFAs, as well as
of vitamin E, against the development of ALS (Veldink et al, Okamoto et al, 2007). This is
difficult to reconcile with the finding that PUFAs more or less destroy vitamin E (Valk & Hornstra,
2000) as well as with the explanation of ALS as a respiratory defect, as the PUFA’s have been
shown to be toxic to mitochondria (Hillered & Chan, 2003). It has also been shown that the
PUFA’s are toxic to lymphocytes, and that their toxicity derives in part from their effect of
depolarizing the mitochondrial membrane, independent of ROS production (“The mechanism of
cell death induced by this oil emulsion was characterized by mitochondrial membrane
depolarization and neutral lipid accumulation but did not alter reactive oxygen species
production.” Cury-Boaventura et al., 2006). Particularly troubling is the ability of the PUFAs to
inhibit glutamate reuptake by neurons, and, to a lesser extent, astrocytes (Yu, Chan, &
Fishman, 1986). Thus, the PUFAs can be implicated in both oxidative stress and glutamate
excitotoxicity, the two main pathological mechanisms central to ALS. Given the many toxic
Page 4
effects of the PUFA’s, especially on the nervous system, reports of a protective effect should be
approached with skepticism.
Mitochondria and Energy Production
Central to an understanding of oxidative stress is an understanding of the source of ROS, the
mitochondria. According to the classical model, mitochondria are composed of an outer
membrane, permeable to small molecules, and an inner membrane, folded into numerous
cristae, that is relatively impermeable (although it is permeable to Ca
2+
). Inside the matrix, the
citric acid cycle transforms the bond energy found in glucose or fatty or amino acids, resulting in
the formation of high-energy electron donor molecules. The electrons are transported between
a series of proteins (the electron transport chain, or ETC) embedded in the inner membrane,
resulting in the transfer of protons from the matrix to the intermembrane space. The electrons
are ultimately accepted by oxygen, which is then released from the cell in the form of carbon
dioxide and water. The process creates an electrochemical gradient of about 200 mv between
the intermembrane space (high voltage) and the matrix (low voltage). Protons flowing down the
gradient, back into the matrix, drive the activity of ATP-synthase.
Discussion of the so-called chemiosmotic hypothesis, with its impermeable membranes and ion
pumps, is certain to leave a bad taste in the mouths of those familiar with an alternative theory
of asymmetric ion distribution, namely, the association-induction hypothesis. While the exact
mechanism of ATP synthesis is debatable, it surely involves a sequential transfer of relatively
high-energy electrons, with oxygen as the terminal acceptor (Ling, 1981). This characteristic
alone is sufficient for understanding much of the pathology associated with mitochondria.
Although the oxidative respiration is very efficient, some of the proteins in the ETC may “leak”
electrons to oxygen, forming the superoxide radical, O
2
-
. The cell’s antioxidant defense system
is normally sufficient to prevent the state of oxidative stress that characterizes ALS and many
other disorders, but in a sick mitochondrion, the rate of ROS production might outpace the
activity of the antioxidant system.
Evidence of Mitochondrial Dysfunction in ALS
That ALS is characterized by a state of oxidative stress is beyond dispute. Oxidative stress is
partially inducible through exogenous toxins and nutrient deficiency as well as being the result
of mitochondrial dysfunction. There is, however, ample evidence for mitochondrial dysfunction,
and an understanding of the relationship between mitochondrial viability and cellular viability is
helpful in understanding the ALS and the other neurodegenerative disorders.
Recently, a novel method was proposed by which mitochondria retain fidelity. Mitochondria
frequently fuse and divide, in a coupled process. Remarkably, the fusion and division of two
depolarized mitochondria results in two daughter mitochondria with a greater difference in
membrane potential than the parents. There is apparently an unequal distribution of the
contents of each mitochondrion, and this process is presumed to help maintain fidelity in one of
Page 5
the daughter mitochondria at the expense of the other one. Mitochondria without an intact
membrane gradient are destined for autophagy and cannot fuse, but they can try to prevent
their fate by dividing. In some cases these divisions may result in the formation of one daughter
with an intact membrane gradient (Twig, Hyde, & Shirihai, 2008). Mitochondria in ALS have
been observed to be highly fragmented, with the obvious implication that they are depolarized
and can undergo fission but not fusion (Magrané & Manfredi, 2009).
The elimination of non-viable mitochondria is mediated by autophagy, and any process that
inhibits autophagy will promote the survival of damaged mitochondria. One mechanism that can
inhibit autophagy is a transport defect. Mitochondria are transported on microtubules by the
dynein-kinesin protein complex. Movement itself might be hindered by a respiratory defect, as
the dynein-kinesin complex requires ATP, and it has in fact been noted that depolarized
mitochondria are immobilized (Rintoul et al, 2006). Additionally, protein aggregates may
physically impede the movement of mitochondria (“Mitochondrial transport can be inhibited in
neurodegenerative diseases where abnormal proteins form insoluble aggregates in neuronal
processes.” Chang & Reynolds, 2006). Such aggregates have been observed in ALS, in the
form of neurofilaments (Bruifin et. al, 2000). Failure to localize enough mitochondria close to
the motor neuron synapse might well result in an unfeasible demand on the mitochondria that
happened to make it, and this could result in mitochondrial induction of apoptosis. Similarly,
limited mobility might impair the fidelity-preserving processes of fission, fusion, and autophagy,
which would contribute to the accumulation of mitochondrial DNA and protein damage and
exacerbate the cellular energy crisis.
Perhaps the most obvious indicator of inefficient or uncoupled respiration in ALS patients can be
found in the simple observation that ALS patients have to eat more. Despite losses of muscle
mass, their resting energy expenditure is some 10% higher than controls (Desport et al., 2001).
Furthermore, caloric supplementation with butter fat (Dupuis et al, 2004) or butter and egg yolk
(Mattson, Cutler, & Camandola, 2007) extends survival in mouse models significantly – from
20% to as much as 200%. It is worth mentioning that these studies used the saturated fatty
acids for supplementation, and that control mice were given primarily PUFAs as the source of
fatty acids. Nor should it be ignored that hyperlipidemia is apparently a protective response in
ALS, and that ALS patients typically present with more severe steatosis than non-ALS patients
(Dupuis et al, 2008). One cannot rule out a protective effect of the saturated fatty acids, which
could be derived in part from their competition with and relative stability compared to the harmful
PUFAs. Since it is well established that the saturated fatty acids protect against fatty liver
disease, a temporary suspension of our cultish beliefs about saturated fat and cholesterol might
be appropriate when studying ALS.
Excitotoxicity
Oxidative stress, while almost certainly present and pathogenic in ALS, is not probably sufficient
to account for the selective degeneration of motor neurons. While there is no simple
explanation as to why motor neurons degenerate and sensory neurons do not, there is one for
Page 6
the distinction seen in ALS between a motor neuron and a non-neuronal cell. Remembering
that damage in ALS not quite limited to neurons, and that motor neurons simply bear the worst
of it, this explanation is sufficient to account for most if not all of ALS morphology.
Neurons are susceptible to a phenomenon known as excitotoxicity. Excitotoxicity refers to the
general process by which excessive excitatory neurotransmitter and deficient cellular energy
conflate to cause an influx of calcium and initiation of the apoptotic cascade; it may be thought
of as a prolonged action potential. As in the case of oxidative phosphorylation, the action
potential may be thought of in a few ways:
According to the classical theory of the action potential, the neuron becomes transiently
permeable to the extracellular cations, sodium and calcium. This results in a rapid influx of the
cations and an establishment of electrical equilibrium, or depolarization. The closing of the “ion
channels” and the action of ion pumps restores the cell to its resting state.
According to the association-induction hypothesis, intracellular potassium is not free, but
adsorbed on the carboxyl groups of extended proteins. ATP functions as a cardinal adsorbent,
facilitating a polarized, oriented state of cell water in which sodium and calcium have limited
solubility. ATP hydrolysis results in a sort of transient chaos, a departure from the so-called
“living state.”
In each model, ATP is critical for the maintenance of the cell’s resting (living) state.
Significantly, it appears that intracellular calcium is transiently stored in the mitochondria, and
that this sequestration of calcium results in increased ATP synthesis. This represents a likely
mechanism by which the cell accelerates its return to the resting state (Miller, 1998). However,
increased ATP synthesis by mitochondria with impaired respiration results in increased
production of ROS, causing damage to proteins and nucleic acids. Thus, excitotoxicity is a
feed-forward process: calcium influx results in calcium sequestration by the mitochondria and
increased production of ATP and ROS. In terms of the association-induction model, ROS
damage proteins, which can longer bind ATP or do not assume the appropriate extended
conformation when they do. The proteins fail to polarize the cell water such that it can exclude
calcium, and the vicious cycle continues. Insufficient production of ATP itself has a similar
effect, decreasing the quantity of the cardinal adsorbent necessary for maintaining the cell in its
living phase.
In terms of the membrane-pump model, deficient ATP production and the ATP-draining effects
of ROS discussed above lead to a concentration of ATP that is insufficient to drive the sodium-
potassium and numerous other pumps located in the cell membrane. Glutamate receptors are
said to be permeable to calcium, and excessive activation of these receptors results in a
constant influx of calcium.
Excessive glutamatergic stimulation can be attributed chiefly to insufficient reuptake of
glutamate by the glial cells. The dysfunction in glumatate clearance can be further traced to a
defect in a glutamate transporter, the excitatory amino acid transporter 2 (EAAT2). Searches
for mutations in these genes have turned up negative, most likely due to cell’s noted policy of
repairing its DNA even at the cost of its life. More likely, the error occurs at the level of
transcription or translation. Indeed, aberrant EAAT2 mRNA species have been found in ALS
Page 7
astrocytes, and EAAT2 is one of the proteins known to be damaged by 4-hydroxynonal
(Robberecht & de Jong, 2000).
The vulnerability of EAAT2 to oxidative stress is one explanation for the selective vulnerability of
motor neurons. One other possible factor in the selectivity of apoptosis is related to the lower
expression of calcium buffering proteins, calbindin D-28K and parvalbumin. It is known,
however, that these proteins are expressed in the oculomotor tract and Onuf’s nucleus, which
are relatively unaffected by ALS (Jackson & Rothstein, 2000).
Apoptosis
Excessive production of ROS or prolonged stimulation by calcium (which are coincident most, if
not all, of the time) results in the initiation of the apoptic cascade. Damaged mitochondria
release their proteins, ostensibly through the opening of a mitochondrial permeability transition
pore (MPTP).
These stimulate the activity of the caspases, a family of proteases, and
DNAases, which rapidly destroy the cell. Though the mechanism of aptoptosis at this point is
rather clear, and probably very hard to reverse anyway, the events immediately preceding it are
not. The purported MPTP is more of an abstraction than an anything else:
“The precise molecular architecture of the pore remains unknown… the identity of the poreforming
protein(s) remains unknown.”
How they escape of the outer membrane is similarly problematic:
“Toxic stimuli such as oxidative stress induce translocation and integration of the pro-death members of
the Bcl-2 family (e.g., Bax, Bak, Bid) into the outer mitochondrial membrane. These proteins, by a
mechanism that remains both elusive and controversial, permeabilize the outer membrane to an extent
that allows the release of pro-apoptotic proteins from the inter-membrane space.” (Baines, 2009)
As it stands, the currently accepted mitochondrial model is not particularly helpful in explaining
the mechanisms of apoptosis. Note that the present conception of cellular biology, with its
membranes, channels, and pumps, as well as the esoteric association-induction hypothesis,
have each been sufficient to explain in rather sparse detail the mechanisms of energy
production, action potential, asymmetrical ion distribution and excitotoxicity. There probably
seemed no reason to even mention it. However, it is becoming increasingly clear that, despite
the thousands of papers authored on the subject over the last nineteen years, the MPTP model
is not generating useful therapies. A different model, in which the localization of ions and
proteins to the mitochondria is controlled by the bulk phase of the matrix, and by its
concentration of ATP, provides a better framework for understanding mitochondrial dissolution
during respiratory distress. Such a model elegantly explains the behavior of non-mitochondrial
cells, and – given the strength of the endosymbiont theory - would likely be productive when
applied to mitochondria.
Page 8
Conclusion
ALS is clearly characterized by a chronic state of oxidative stress, induced by mitochondrial
dysfunction, and exacerbated by insufficient energy intake. While glutamate excitotoxicity is
likely the major pathological mechanism, excitotoxicity itself can be traced to damage induced
by oxidative stress. Notwithstanding a few survey-based studies, there is reason to belief that
excess dietary iron and PUFAs are contributing factors, while the antioxidant vitamins and
cofactors as well as the saturated fatty acids are protective. The involvement of oxidative
stress in nearly every physiological disorder, including heart disease and diabetes, suggests
that these disorders may have a common etiology. Let it be suggested here that ALS is in fact
very closely related to diabetes, and that the obvious differences in disease presentation can be
attributed primarily to differences hormonal profiles arising in no small part from differences in
energy intake and expenditure. This idea is not unsupported (Krentz, Williams, & Nattrass,
1992).
The notion of the MPTP seems to have arisen in the same way the myriad membrane pumps
did: as a concession to the purported existence of an impermeable membrane. Rather than
searching for therapeutic targets such as the MPTP, which may or may not exist, it would be
wise to reevaluate our model of the cell as well as the political and financial interests that
influence our conceptions of nutrition and medicine. ALS treatment, like all modern treatments,
has tended towards the extravagant, the synthetic and the high-tech. Seeing as the politically
correct intellectual framework has failed to produce any useful therapies, I think a revision of
some of our ideas involving fats, vitamins, and membranes is overdue.
References:
Ascherio et al. Vitamin E intake and risk of amyotrophic lateral sclerosis. Ann Neurol. 2005
Jan;57(1):104-10.
Baines, Christopher P.. The mitochondrial permeability transition pore and ischemia-reperfusion
injury. Basic Res Cardiol (2009) 104:181–188
Berge K, Tronstad KJ, Bohov P, Madsen L, Berge RK. Impact of mitochondrial beta-oxidation in
fatty acid-mediated inhibition of glioma cell proliferation. J Lipid Res. 2003;44:118–127.
Brown, Robert H. Jr, Pasinelli, Piera. Apoptosis in amyotrophic lateral sclerosis: a review.
Amyotrophic Lateral Sclerosis. Ed. Brown, Robert H Jr., Meininger, Vincent, Swash, Michael.
London: Martin Dunitz Ltd., 2000. 363-369.
Bruijn, Lucie I, Williamson, Toni L, Becher, Mark W. Price, Donald L, Cleveland, Don W.
Neurofilament and familial amyotrophic lateral sclerosis-linked mutant copper-zinc superoxide
dismutase-mediated motor neuron degeneration: insights from transgenic mouse models.
Amyotrophic Lateral Sclerosis. Ed. Brown, Robert H Jr., Meininger, Vincent, Swash, Michael.
London: Martin Dunitz Ltd., 2000. 341- 362.
Chen H, Li D, Saldeen T, Romeo F, Mehta JL, Mixed tocopherol preparation is superior to
alpha-tocopherol alone against hypoxia-reoxygenation injury. Biochem Biophys Res Commun
2002
Page 9
Conrad C. Weihl, Glenn Lopate: Motor neuron disease associated with copper deficiency.
Muscle & Nerve 2006; 34(6):789-793
Cury-Boaventura MF, Gorjao R, de Lima TM, Piva TM, Peres CM, Soriano FG, Curi R. Toxicity
of a soybean oil emulsion on human lymphocytes and neutrophils. Journal of Parenteral and
Enteral Nutrition 2006; 30 (2): 115-123.
D.T.W. Chang, I.J. Reynolds Mitochondrial trafficking and morphology in healthy and injured
neurons. Prog Neurobiol. 2006 Dec; 80(5):241-68
Desport JC, Preux PM, Magy L, et al. Factors correlated with hypermetabolism in patients with
amyotrophic lateral sclerosis. Am J Clin Nutr 2001;74:328–334
Dupuis L, Oudart H, Rene F, Gonzalez de Aguilar JL, Loeffler JP. Evidence for defective energy
homeostasis in amyotrophic lateral sclerosis: benefit of a high-energy diet in a transgenic
mouse model. Proc Natl Acad Sci USA 2004; 101:11159–11164.
Dupuis, L et al. Dyslipidemia is a protective factor in amyotrophic lateral sclerosis. PhDVolume
2008; 70(13):1004-1009
Fu MX, Requena JR, Jenkins AJ, Lyons TJ, Baynes JW, Thorpe SR. The advanced glycation
end product, Nepsilon-(carboxymethyl)lysine, is a product of both lipid peroxidation and
glycoxidation reactions. J Biol Chem 1996;271(17):9982-6.
Gilad Twig, Brigham Hyde, Orian S. Shirihai. Mitochondrial fusion, fission and autophagy as a
quality control axis: The bioenergetic view. Biochimica et Biophysica Acta 2008; 1777: 1092–
1097
Hartmann HA, Evenson MA. Deficiency of copper can cause neuronal degeneration. Med
Hypotheses. 1992; 38(1):75-85.
Hillered L, Chan PH. Brain mitochondrial swelling induced by arachidonic acid and other long
chain free fatty acids. Endocrinology. 2003;144(9):3958-68
Jackson, Mandy, Rothstein, Jeffrey D. Biochemical pathology. Amyotrophic Lateral Sclerosis.
Ed. Brown, Robert H Jr., Meininger, Vincent, Swash, Michael. London: Martin Dunitz Ltd.,
2000; 263-274.
Jeong SY, Rathore KI, Schulz K, Ponka P, Arosio P, David S. Dysregulation of iron homeostasis
in the CNS contributes to disease progression in a mouse model of amyotrophic lateral
sclerosis. J Neurosci. 2009;29(3):610-9.
Jordi Magrané, Giovanni Manfredi. Antioxidants & Redox Signaling. -Not available-, ahead of
print. doi:10.1089/ARS.2009.2604.
Kim, S.H., et al. Widespread increased expression of the DNA repair enzyme PARP in brain in
ALS. Neurology. 2004; 61(2):319-322
Korge P, Honda HM, Weiss JN. Effects of fatty acids in isolated mitochondria: implications for
ischemic injury and cardioprotection. Am J Physiol Heart Circ Physiol. 2003;285:H259–H269.66.
Page 10
Krentz, A.J., Williams, A.C., Nattrass, M. Glucose intolerance associated with motor neuron
disease: evidence for insulin resistance in multiple aspects of carbohydrate and lipid
metabolism. Diabetes Nutr. Metab. 1992; 5: 211–220
Kumar N, Gross JB, Ahlskog JE. Copper deficiency myelopathy produces a clinical picture like
subacute combined degeneration. Neurology 2004; 63: 33-39
Ling, Gilbert N. Oxidative Phosphorylation and Mitochondrial Physiology: A critical review of the
chemiosmotic theory, and reinterpretation by the association-induction hypothesis. Physiol.
Chem. & Phsyics 13 1981.
Lou Gehrig's Disease (ALS). Accessed May 4, 2009. http://www.mayoclinic.org/lou-gehrigs-
disease/diagnosis.html
Mattson MP, Cutler RG, Camandola S. Energy intake and amyotrophic lateral sclerosis.
Neuromolecul Med 2007;9:17–20
Miller RJ. Mitochondria – the kraken wakes! Trends in Neurosci. 1998; 21(3): 95–97
NINDS Amyotrophic Lateral Sclerosis Information Page Accessed May 4, 2009
http://www.ninds.nih.gov/disorders/amyotrophiclateralsclerosis/amyotrophiclateralsclerosis.htm
Okamoto K, Kihira T, Kondo T, Kobashi G, Washio M, Sasaki S, Yokoyama T, Miyake Y,
Sakamoto N, Inaba Y, Nagai M. Nutritional status and risk of amyotrophic lateral sclerosis in
Japan. Amyotroph Lateral Scler 2007; 8 (5): 300–4
Orla McGuinness, Orla, Yafei, Nasser, Cost, Andreas, Crompton, Martin. The presence of two
classes of high-affinity cyclosporin A binding sites in mitochondria Evidence that the minor
component is involved in the opening of an inner-membrane Ca
2+
dependent pore. Eur. J.
Biochem 1990; 194:671 -679
Peat, Ray. Unsaturated fatty acids: Nutritionally essential, or toxic? Ray Peat. 2006.
http://raypeat.com/articles/articles/unsaturatedfats.shtml
Peat, Ray. Vitamin E: Estrogen antagonist, energy promoter, and anti-inflammatory. Ray Peat.
2006. http://raypeat.com/articles/articles/vitamin-e.shtml
Ringholz, G. M. et al. Prevalence and patterns of cognitive impairment in sporadic ALS.
Neurology 2005; 65(4):586-590
Rintoul, G.L., Bennett, V.J., Papaconstandinou, N.A., Reynolds, I.J. Nitric oxide inhibits
mitochondrial movement in forebrain neurons associated with disruption of mitochondrial
membrane potential. J. Neurochem2006: 97(3); 800–806.
Robberecht, Wim L, de Jong, JMB Vianney. Oxidative stress in amyotrophic lateral sclerosis:
pathogenic mechanism or epiphenomena? Amyotrophic Lateral Sclerosis. Ed. Brown, Robert H
Jr., Meininger, Vincent, Swash, Michael. London: Martin Dunitz Ltd., 2000; 113-131.
Sen Chandan K. ; Khanna Savita ; Roy Sashwati. Tocotrienol: The natural vitamin E to defend
the nervous system? Annals of the New York Academy of Sciences. 2004; 1031:127-142
Page 11
Shaw, Pamela J. Biochemical pathology. Amyotrophic Lateral Sclerosis. Ed. Brown, Robert H
Jr., Meininger, Vincent, Swash, Michael. London: Martin Dunitz Ltd., 2000; 176-185.
Valk EE, Hornstra G. Relationship between vitamin E requirement and polyunsaturated fatty
acid intake in man: a review. Int J Vitam Nutr Res 2000; 70(2):31-42.
Veldink JH, Kalmijn S, Groeneveld GJ, Wunderink W, Koster A, de Vries JH, van der Luyt J,
Wokke JH, Van den Berg LH. Intake of polyunsaturated fatty acids and vitamin E reduces the
risk of developing amyotrophic lateral sclerosis. J. Neurol. Neurosurg. Psychiatr. 2007; 78(4):
367–71
Yan CH, Liang ZQ, Gu ZL, Yang YP, Reid P, Qin ZH. Contributions of autophagic and apoptotic
mechanisms to CrTX-induced death of K562 cells. Toxicon 2006; 47: 521–30
Yu AC, Chan PH, Fishman RA. Effects of arachidonic acid on glutamate and gamma-
aminobutyric acid uptake in primary cultures of rat cerebral cortical astrocytes and neurons. J
Neurochem. 1986; 47(4):1181-9.
