Îµ4 Allele Is Associated with Lower Selenium Levels in the Brain

Subscriber access provided by Eastern Michigan University | Bruce T. Halle Library

Letter

The APOE #4 allele is associated with lower selenium levels in the brain: implications in Alzheimer’s disease Barbara Rita Cardoso, Dominic J Hare, Monica Lind, Catriona A. McLean, Irene Volitakis, Simon M. Laws, Colin L. Masters, Ashley I. Bush, and Blaine R Roberts ACS Chem. Neurosci., Just Accepted Manuscript • Publication Date (Web): 28 Apr 2017 Downloaded from http://pubs.acs.org on May 3, 2017

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

ACS Chemical Neuroscience is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 15

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Chemical Neuroscience

1 2 3

The APOE ε4 allele is associated with lower selenium levels in the brain: implications in Alzheimer’s disease

4 5

Bárbara R. Cardoso1,2*, Dominic J. Hare1,3, Monica Lind1, Catriona A. McLean1,4, Irene Volitakis1, Simon M. Laws5,6, Colin L. Masters1,6, Ashley I. Bush1,6, Blaine R. Roberts1,6*

6 7

1

8 9

2

Faculty of Pharmaceutical Sciences, Department of Food and Experimental Nutrition, University of São Paulo, São Paulo, Brazil

10 11

3

Elemental Bio-imaging Facility, University of Technology Sydney, Broadway, New South Wales, Australia

12

4

Department of Anatomical Pathology, Alfred Hospital, Prahran, Victoria, Australia

13 14

5

15

6

The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia

Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, Western Australia, Australia Co-operative Research Centre for Mental Health, http://www.mentalhealthcrc.com

16 17 18 Running title: Selenium distribution in brain 19 Key-words: selenium, Alzheimer’s disease, APOE ε4 20 21

* Corresponding authors:

22 23 24

Bárbara R. Cardoso, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, 30 Royal Parade, Parkville, Victoria, 3052, Australia. Ph +61 450 633 537; Email: [email protected]

25 26 27

Blaine Roberts, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, 30 Royal Parade, Parkville, Victoria, 3052, Australia. Ph +61 450 633 537; Email: [email protected]

28

ACS Paragon Plus Environment

1


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 2 of 15

29

Abstract

30

The antioxidant activity of selenium, which is mainly conferred by its incorporation into

31

dedicated selenoproteins, has been suggested as a possible neuroprotective approach for

32

mitigating neuronal loss in Alzheimer’s disease. However, there is inconsistent information

33

with respect to selenium levels in the Alzheimer’s disease brain. We examined the

34

concentration and cellular compartmentalization of selenium in the temporal cortex of

35

Alzheimer’s disease and control brain tissue. We found that Alzheimer’s disease was

36

associated with decreased selenium concentration in both soluble (i.e. cytosolic) and

37

insoluble (i.e. plaques and tangles) fractions of brain homogenates. The presence of the

38

APOE ε4 allele correlated with lower total selenium levels in the temporal cortex and a

39

higher concentration of soluble selenium. Additionally, we found that age significantly

40

contributed to lower selenium concentrations in the peripheral membrane-bound and

41

vesicular fractions. Our findings suggest a relevant interaction between APOE ε4 and

42

selenium delivery into brain, and show changes in cellular selenium distribution in the

43

Alzheimer’s disease brain.

44 45


2

Page 3 of 15

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


46

Selenium is an essential micronutrient known for its antioxidant role via the incorporation of

47

selenocysteine (SeCys) in 25 thus-far identified human selenoproteins. In the brain, the

48

importance of selenium in regulating oxidative stress in the central nervous system is

49

reinforced by the position of the brain atop a selenium hierarchy, as it is the typically last

50

organ to be depleted of stores in cases of deficiency, and the first to revert to normal levels

51

when selenium levels become replete.1, 2 Selenium has multiple roles in other systems which

52

may influence accessibility of the brain to this essential micronutrient; for instance, the

53

important role of selenium in male fertility can result in ‘competition’ between the brain and

54

testes during situations of extreme deficiency.3

55

Selenium status has been associated with cognitive performance, although there are

56

conflicting opinions regarding the most reliable biomarker for assessing selenium levels and

57

need.4-6 Several trials have been conducted that focused on selenium status as possible

58

therapeutic target for Alzheimer’s disease. A systematic review performed in 2011

59

highlighted that while there was no direct evidence supporting a role for selenium in treating

60

the disease, noted that the base of knowledge regarding selenium in Alzheimer’s disease was

61

small, and that future therapeutic benefits could not be ruled out.7 Subsequent clinical trials

62

have reached a similar conclusion, failing to identify significant clinical outcomes, yet

63

observing small trends that indicated some degree of neurological efficacy of selenium

64

supplementation.8 A common conclusion reached by those conducting clinical trials

65

examining selenium status in Alzheimer’s disease is that longer-term treatment may prove to

66

have more significant effects. Taken together, these studies suggest that selenium has a more

67

nuanced role in Alzheimer’s disease pathology, and that a better understanding of the role

68

selenium plays in the molecular basis of neurodegeneration is required to design future, long-

69

term targeted therapies.

70

The selenoprotein glutathione peroxidase 4 (GPx4) is an important inhibitor of ferroptosis in

71

neurodegeneration, a non-apoptotic form of cell death that features increased oxidative stress

72

by increases in labile cellular iron levels.9 GPx4 activity has been implicated in ferroptotic

73

cancer cell death10 and acute renal failure in mice,11 and the long-standing association

74

between iron and neurodegeneration suggests that ferroptosis is a mechanism intrinsic to cell

75

loss in Parkinson’s and Alzheimer’s disease.12 GPx4 has been identified as a component in an

76

oxidative stress-induced neurodegenerative process that is now widely known as

77

ferroptosis.13 As selenium is a key factor for GPx4 expression and activity, we recently

78

suggested that availability of this element to the brain is essential for neuroprotection and


3


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 4 of 15

79

may represent a specific target for treating Alzheimer’s disease via modulation of the brain

80

selenoproteome.14

81

Specific data directly assessing selenium levels in the Alzheimer’s disease brain is scarce.

82

Ramos et al.15 reported a specific decrease in hippocampal selenium levels and increase in the

83

superior temporal gyrus, frontal cortex, midbrain and putamen, though (as the authors

84

acknowledged), the very small sample size (n = 2) of Alzheimer’s disease tissue limits

85

interpretation of these data. Morris and colleagues16 conducted a more extensive study,

86

examining the relationship between seafood consumption, brain mercury and selenium levels

87

and ApoE ε4 status in 286 elderly brains. Increased selenium was associated with higher

88

neurofibrillary tangle severity according to Braak pathological staging.

89

In light of the mounting evidence regarding the importance of selenium in normal brain

90

function, and the recent literature reporting possible neuroprotective benefits in Alzheimer’s

91

disease, we investigated the cellular distribution and concentration of selenium in the

92

temporal cortex of post mortem Alzheimer’s disease subjects compared to control samples;

93

and examined the relevance of the high-risk APOE ε4 genotype on selenium distribution.

94 95

Results and Discussion

96

We analysed 38 Alzheimer’s disease brain samples and 33 control samples. Subject

97

demographics for both groups are presented in Table 1. This study describes the distribution

98

of selenium in cellular fractions within the temporal cortex of Alzheimer’s disease subjects,

99

compared to control samples (Figure 1). Selenium was most concentrated in the membrane

100

fraction (64.67 ± 20.56 and 53.99 ± 17.71 ng g-1 of wet tissue in control and Alzheimer’s

101

disease samples, respectively), where the selenoproteins iodothyronine deiodinase 217 and

102

selenoprotein K18 are most abundant. GPx4 is a membrane-associated protein enriched in

103

mitochondria,19 though its activity is also detectable to a lesser extent in the cytosol.20 The

104

insoluble formic acid fraction, that most likely corresponds to proteinaceous aggregates,

105

including Aβ plaques and tau-containing neurofibrillary tangles, contained the lowest

106

selenium concentration (6.28 ± 2.56 and 4.42 ± 2.60 ng g-1 in control and Alzheimer’s

107

disease samples, respectively). While it is possible that interactions between selenoproteins

108

and solvents used (e.g. loss of hydrophilic selenoproteins from insoluble plaques into the

109

‘cytosolic’ fraction) may contribute some degree of redistribution and overlap, all samples


4

Page 5 of 15

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


110

were prepared in an identical fashion, and the low concentrations of selenium in each fraction

111

suggests potential confounding effects were negligible.

112

Alzheimer’s brain samples had lower total selenium concentration, which was reflected in

113

lower levels in the soluble, membrane and insoluble fractions (Fig. 1C). However, when we

114

further investigated the differences in each selenium variable across the diagnostic groups

115

using linear regression models that considered the presence of the APOE ε4 allele and age as

116

potential confounders, Alzheimer’s disease was not associated with a change in total

117

selenium levels, but was negatively associated with selenium content in soluble and insoluble

118

fractions (Table 2). These findings do not corroborate previous studies that reported an

119

association between selenium concentration and neurofibrillary tangle severity in two cortical

120

areas16 and the presence of selenoprotein P in plaques21 (although it is difficult to distinguish

121

if this colocalization represents a role of selenoprotein P in plaque formation or is merely the

122

consequence of a protein-dense aggregate). However, our findings do support the hypothesis

123

that the ratio Sec:Cys in selenoproteins is decreased, and even though selenoprotein P levels

124

are increased in Alzheimer’s disease brains, it is not delivering selenium efficiently to

125

promote synthesis of other selenoproteins in neurons. This process would be associated with

126

the selenoprotein synthesis hierarchy disturbance, unsuccessfully neutralizing localized

127

oxidative stress in neurons. Consistent with this hypothesis, we observed an effect of ageing

128

on selenium distribution among different brain fractions, as age was negatively associated

129

with selenium levels in peripheral membranes and vesicles, though other studies have

130

reported higher expression of selenoprotein P associated with ageing 22, 23.

131

The results presented here are consistent with our hypothesis that reduced availability of

132

selenium to neurons limits the expression of selenoproteins, such as the antioxidant and

133

ferroptotic regulator GPx4, which causes impaired neurological function with implications

134

beyond just Alzheimer’s disease. Both in and ex vivo depletion of GPx4 causes neuron-

135

specific degeneration.13 GPx4 is essential for the development of parvalbumin-positive

136

interneuron development, and genetic ablation causes seizures, ataxia24 and rapid

137

neurodegeneration.25 Dysfunction of the innate mechanism regulating selenoprotein synthesis

138

causes marked neurodevelopmental deficits, primarily via the negative effect on

139

paravalbumin-positive neuron proliferation.26

140

We also report that APOE ߝ4 allele carriers had both decreased total selenium levels and

141

reduced selenium concentrations in the membrane fraction when compared to non-ߝ4-

142

carriers, irrespective of clinical classification (Fig. 1D). Nonetheless, univariate statistical


5


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 6 of 15

143

modelling revealed that total selenium levels in the temporal cortex are independently

144

influenced by APOE genotype, and not the disease. Although this analysis does not confirm

145

an association between APOE ߝ4 allele and selenium content in membrane fraction, it does

146

demonstrate a positive correlation between the APOE ߝ4 allele and selenium content in the

147

soluble fraction (Table 2). This genotype is the most significant genetic risk factor for late-

148

onset Alzheimer’s disease,27-29 and is relevant to selenium metabolism as delivery of

149

selenium into the brain is modulated by ApoE receptor 2 (ApoER2). This receptor interacts

150

with selenoprotein P either at the blood-brain barrier or inside the brain to supply selenium to

151

neurons and glial cells.30 One previous study has shown that the ApoE4 isoform has impaired

152

recycling capacity in embryonic cortical neurons, which contributes to increased

153

sequestration of ApoER2 into intracellular compartments. As a consequence, the receptor

154

presents reduced surface expression at the plasma membrane.31 Furthermore, ApoE4

155

selectively antagonizes ApoE3-ApoER2 in endothelial cells, affecting eNOS and kinase

156

activation, as well as inhibiting cell migration, likely due to a conformational change in

157

ApoER2.32 From the data presented here, we hypothesize that the presence of the ApoE4

158

isoform may modify or reduce expression of ApoER2, leading to reduced binding with

159

selenoprotein P and decreased selenium delivery to the brain. As consequence, the APOE ߝ4

160

genotype could also result in increased selenoprotein P concentration in CSF, however such

161

association needs to be further investigated.

162

We have previously reported that a selenium deficient intake may increase risk for

163

Alzheimer’s disease,5 and incremented intake with selenium-rich food source contributes to

164

better cognitive performance.33 This indicates an association between diet, selenium status

165

and neurodegeneration. Hence, selenium nutritional status and diet aspects should be

166

carefully considered when selenium levels in brain are assessed regarding to

167

neurodegeneration. Our previous study has shown that elderly from two different areas in

168

Australia did not present selenium deficiency,34 which is in agreement with other studies that

169

show Australians have a selenium-replete diet.35,

170

significantly influenced by selenium intake, but that the APOE ε4 allele may be associated

171

Alzheimer’s disease pathogenesis due to its negative effects on selenium delivery into brain.

172

Additionally, APOE ε4 allele status was associated with higher selenium concentrations in

173

the soluble fraction, and this can lead to misinterpretation of selenium data if not taken into

174

account. We therefore highlight the importance of considering this genotype in further studies

36

Thus, we believe our findings are not


6

Page 7 of 15

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


175

that aim to investigate the association of selenium concentration in brain and Alzheimer’s

176

disease.

177 178

Methods

179

Human post-mortem tissue collection. Temporal cortex samples were obtained

180

from the Victorian Brain Bank Network. Control brains were defined as free from

181

Alzheimer’s disease lesions or significant neuropathology by a trained neuropathologist (i.e.

182

numbers of plaques and tangles were below the defined cut-off values for the NIA Regan

183

criteria for diagnosis

184

neuropathological examination. All procedures were approved by the University of

185

Melbourne Health Sciences, Human Ethics subcommittee (ID1136882).

37

). Alzheimer’s disease brain tissues were similarly confirmed by

186

Tissue fractionation. Hemisected frozen brains were thawed from −80 ˚C to −20 ˚C

187

and the meninges were removed from approximately 5 g of temporal cortex (Brodmann area

188

9). Grey matter was dissected in to 0.2 – 0.5 g aliquots and stored at −80 ˚C. The tissue was

189

weighed and thawed on ice, then homogenised using a BioMasher (Omni International) and

190

centrifuged at 100,000 g with a benchtop centrifuge. Tris buffered saline (TBS, 50 mM Tris

191

pH 8.0, 100 mM NaCl) containing EDTA free protease inhibitors (Roche, 05056489001) was

192

then added at a ratio of 1:4 (tissue:buffer; w/v). The cytosolic, or ‘soluble’ fraction (all

193

material soluble in the TBS buffer) was collected as the supernatant after centrifugation at

194

100,000 g for 30 minutes at 4 ˚C. The remaining pellet was re-suspended in 100 mM NaCO3

195

pH 11.0 (1:4 tissue:buffer; w/v). Samples were incubated on ice for 20 min before

196

centrifugation at 100,000 g for 30 minutes at 4 ˚C. The supernatant containing peripheral

197

membrane proteins and vesicular (the ‘peripheral membrane/vesicular’ fraction) material was

198

removed. The resultant pellet was re-suspended with 7 M urea, 2 M thiourea, 4% CHAPS, 30

199

mM bicine, pH 8.5 and centrifuged (100,000 g for 30 minutes at 4 ˚C) and the supernatant

200

(the ‘membrane’ fraction) was retained. Finally, the ‘insoluble’ fraction was obtained by

201

digesting the remaining material in 70% formic acid for 16 – 18 hours and centrifuged as

202

above. The supernatant was collected, with negligible material remaining. All fractions were

203

stored at -80 ˚C until analysis.

204

APOE genotyping. DNA was extracted from fresh frozen brain tissue using the

205

PureLink® Genomic DNA kit (ThermoFisher Scientific) following manufacturer’s protocol.

206

To ascertain APOE genotype TaqMan® genotyping assays (rs7412, assay ID:


7


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 8 of 15

207

C____904973_10; rs429358, assay ID: C___3084793_20; Life Technologies, Carlsbad, CA)

208

were performed on a QuantStudio 12K Flex™ Real-Time-PCR systems (Applied

209

Biosystems) using TaqMan® GTXpress™ Master Mix (Life Technologies) following

210

manufacturer’s instructions. In this study APOE carrier status was defined by the presence (1

211

or 2 copies; carrier) or absence (0 copies; non-carrier) of the APOE ε4 allele.

212

Selenium assay. Aliquots of brain fractions were diluted with 1% HNO3 at the

213

following ratios (all v/v): soluble, peripheral membrane/vesicular and membrane fractions

214

1:15; insoluble fraction 1:30. Selenium-78 was chosen as the isotope to be monitored using

215

the Agilent Technologies 7700x Series inductively coupled plasma-mass spectrometry (ICP-

216

MS) system (Agilent Technologies, Mulgrave, Australia). Hydrogen was used as reaction gas

217

for analysis in order to reduce polyatomic interferences on the chosen selenium isotope 38. A

218

calibration curve was prepared using a multielement standard solution containing 0, 0.1, 0.3,

219

0.5, 1, 5, 10 µg L-1 of selenium. An internal standard solution containing 200 µg L-1 of

220

yttrium (89Y) in 1% HNO3 was used as a reference element and was introduced on-line via a

221

T-piece. The method validity was confirmed by recovery analysis of a certified lyophilised

222

human reference control (Seronorm Trace Elements Serum and Whole Blood, Sero AS). For

223

each analysis, the accepted recovery of the reference material was > 90%.

224

Statistical analysis. All results are expressed as the mean ± standard deviation (SD)

225

or continuous variables, and as a percentage for categorical data. A Kolmogorov-Smirnov

226

test was used to determine the normality of the data. The values from membrane fraction

227

were not normally distributed and were thus log-transformed. Two-tailed unpaired Student’s t

228

tests were performed to compare selenium concentration between diagnosis groups and

229

APOE genotypes, according to ε4 allele carrier status. To further assess the differences in

230

each selenium variable across the diagnostic groups, multiple regression models were

231

developed to obtain the minimum model factoring for APOE genotype (presence/absence of

232

the ε4 allele), age and sex as covariates. For all dependent variables, the resultant minimum

233

model contained all covariates excluding sex. Postmortem interval was not considered for

234

multiple regression models as preliminary analysis with correlation tests (Pearson or

235

Spearman) did not identify any correlation between age and selenium. A p-value less than

236

0.05 was considered statistically significant. All statistical analyses were carried out using the

237

IBM Statistical Package for the Social Sciences (SPSS) software, v 23.0 (IBM Corporation)

238

and Prism v6.0h (GraphPad) was used to construct figures.

239


8

Page 9 of 15

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


240

Funding sources:

241

BRC was supported by a Science without Borders (Ciência sem Fronteiras) Fellowship. DJH

242

is a National Health and Medical Research Council Career Development Fellow

243

(APP1122981). SML, BRR, AIB and CLM received financial support from the Cooperative

244

Research Centre (CRC) for Mental Health (Grant ID: 20100104), an Australian Government

245

Initiative. Tissues were received from the Victorian Brain Bank Network, supported by The

246

University of Melbourne, Alfred Hospital, the Victorian Forensic Institute of Medicine, the

247

National Health and Medical Research Council. We acknowledge funding from the Victorian

248

Government’s Operational Infrastructure Support Program and the Australian Research

249

Council Linkage Projects Scheme (LP140100095, with Agilent Technologies).

250 251

Author contributions:

252

BRC designed and performed experiments, analysed data and wrote the paper. DJH: analysed

253

data and wrote the paper. ML: prepared tissue samples for analysis. CAM: Conducted

254

pathological examination and diagnosis of brain tissue. CLM: supervised and provided

255

financial support for ML. AIB: supervised the project. SML: provided APOE genotyping. IV:

256

prepared tissue samples for analysis. BRR: designed the experiments, wrote the paper and

257

supervised the project. All authors contributed to, edited and approved the manuscript.

258 259

Conflict of interest:

260

B.R.R. and D.J.H. receive research support from Agilent Technologies. A.I.B. is a

261

shareholder of Cogstate Ltd, Prana Biotechnology Ltd, Mesoblast Ltd, Collaborative

262

Medicinal Development Pty Ltd, Grunbiotics Pty Ltd, Brighton Biotech LLC, and a paid

263

consultant for Collaborative Medicinal Development Pty Ltd. CLM is a shareholder for Prana

264

Biotechnology and consultant for Eli Lilly & Co; all other authors declare no competing

265

financial interests.

266 267 268 269 270 271 272 273

References: [1] Cardoso, B. R., Roberts, B. R., Bush, A. I., and Hare, D. J. (2015) Selenium, selenoproteins and neurodegenerative diseases., Metallomics 7, 1213-1228. [2] Nakayama, A., Hill, K. E., Austin, L. M., Motley, A. K., and Burk, R. F. (2007) All regions of mouse brain are dependent on selenoprotein P for maintenance of selenium, J. Nutr. 137, 690-693.


9


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323

Page 10 of 15

[3] Pitts, M. W., Kremer, P. M., Hashimoto, A. C., Torres, D. J., Byrns, C. N., Williams, C. S., and Berry, M. J. (2015) Competition between the Brain and Testes under Selenium-Compromised Conditions: Insight into Sex Differences in Selenium Metabolism and Risk of Neurodevelopmental Disease, J. Neurosci. 35, 15326-15338. [4] Olde Rikkert, M. G., Verhey, F. R., Sijben, J. W., Bouwman, F. H., Dautzenberg, P. L., Lansink, M., Sipers, W. M., van Asselt, D. Z., van Hees, A. M., Stevens, M., Vellas, B., and Scheltens, P. (2014) Differences in nutritional status between very mild Alzheimer's disease patients and healthy controls, J. Alzheimers Dis. 41, 261-271. [5] Cardoso, B. R., Ong, T. P., Jacob-Filho, W., Jaluul, O., Freitas, M. I., and Cozzolino, S. M. (2010) Nutritional status of selenium in Alzheimer's disease patients, Br. J. Nutr. 103, 803-806. [6] Rita Cardoso, B., Silva Bandeira, V., Jacob-Filho, W., and Franciscato Cozzolino, S. M. (2014) Selenium status in elderly: relation to cognitive decline, J. Trace Elem. Med. Biol. 28, 422-426. [7] Loef, M., Schrauzer, G. N., and Walach, H. (2011) Selenium and Alzheimer's Disease: A Systematic Review, J. Alzheimers Dis. 26, 81-104. [8] Malpas, C. B., Vivash, L., Genc, S., Saling, M. M., Desmond, P., Steward, C., Hicks, R. J., Callahan, J., Brodtmann, A., Collins, S., Macfarlane, S., Corcoran, N. M., Hovens, C. M., Velakoulis, D., and O’Brien, T. J. (2016) A Phase IIa Randomized Control Trial of VEL015 (Sodium Selenate) in Mild-Moderate Alzheimer's Disease., J. Alzheimers Dis. 54, 223-232. [9] Dixon, S. J., Lemberg, K. M., Lamprecht, M. R., Skouta, R., Zaitsev, E. M., Gleason, C. E., Patel, D. N., Bauer, A. J., Cantley, A. M., Yang, W. S., Morrison, B., 3rd, and Stockwell, B. R. (2012) Ferroptosis: an iron-dependent form of nonapoptotic cell death, Cell 149, 1060-1072. [10] Yang, W. S., SriRamaratnam, R., Welsch, M. E., Shimada, K., Skouta, R., Viswanathan, V. S., Cheah, J. H., Clemons, P. A., Shamji, A. F., Clish, C. B., Brown, L. M., Girotti, A. W., Cornish, V. W., Schreiber, S. L., and Stockwell, B. R. (2014) Regulation of ferroptotic cancer cell death by GPX4, Cell 156, 317-331. [11] Friedmann Angeli, J. P., Schneider, M., Proneth, B., Tyurina, Y. Y., Tyurin, V. A., Hammond, V. J., Herbach, N., Aichler, M., Walch, A., Eggenhofer, E., Basavarajappa, D., Radmark, O., Kobayashi, S., Seibt, T., Beck, H., Neff, F., Esposito, I., Wanke, R., Forster, H., Yefremova, O., Heinrichmeyer, M., Bornkamm, G. W., Geissler, E. K., Thomas, S. B., Stockwell, B. R., O'Donnell, V. B., Kagan, V. E., Schick, J. A., and Conrad, M. (2014) Inactivation of the ferroptosis regulator Gpx4 triggers acute renal failure in mice, Nat. Cell Biol. 16, 1180-1191. [12] Belaidi, A. A., and Bush, A. I. (2016) Iron neurochemistry in Alzheimer's disease and Parkinson's disease: targets for therapeutics, J. Neurochem. 139 (Supp 1), 179-197. [13] Seiler, A., Schneider, M., Forster, H., Roth, S., Wirth, E. K., Culmsee, C., Plesnila, N., Kremmer, E., Radmark, O., Wurst, W., Bornkamm, G. W., Schweizer, U., and Conrad, M. (2008) Glutathione peroxidase 4 senses and translates oxidative stress into 12/15-lipoxygenase dependent- and AIF-mediated cell death, Cell Metab. 8, 237-248. [14] Cardoso, B. R., Hare, D. J., Bush, A. I., and Roberts, B. R. (2016) Glutathione peroxidase 4: a new player in neurodegeneration?, Mol. Psychiatry. [15] Ramos, P., Santos, A., Pinto, N. R., Mendes, R., Magalhaes, T., and Almeida, A. (2015) Anatomical regional differences in selenium levels in the human brain, Biol. Trace Elem. Res. 163, 89-96. [16] Morris, M., Brockman, J., Schneider, J. A., and et al. (2016) Association of seafood consumption, brain mercury level, and apoe ε4 status with brain neuropathology in older adults, JAMA 315.


10

Page 11 of 15

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372


[17] Behne, D., Kyriakopoulos, A., Meinhold, H., and Köhrle, J. (1990) Identification of type I iodothyronine 5′-deiodinase as a selenoenzyme, Biochem. Biophys. Res. Commun. 173, 1143-1149. [18] Verma, S., Hoffmann, F. W., Kumar, M., Huang, Z., Roe, K., Nguyen-Wu, E., Hashimoto, A. S., and Hoffmann, P. R. (2011) Selenoprotein K Knockout Mice Exhibit Deficient Calcium Flux in Immune Cells and Impaired Immune Responses, J. Immunol. 186, 2127-2137. [19] Liang, H., Yoo, S.-E., Na, R., Walter, C. A., Richardson, A., and Ran, Q. (2009) Short form glutathione peroxidase 4 is the essential isoform required for survival and somatic mitochondrial functions., J. Biol. Chem. 284, 30836-30844. [20] Yant, L. J., Ran, Q., Rao, L., Van Remmen, H., Shibatani, T., Belter, J. G., Motta, L., Richardson, A., and Prolla, T. A. (2003) The selenoprotein GPX4 is essential for mouse development and protects from radiation and oxidative damage insults, Free Radic. Biol. Med. 34, 496-502. [21] Bellinger, F. P., He, Q. P., Bellinger, M. T., Lin, Y., Raman, A. V., White, L. R., and Berry, M. J. (2008) Association of selenoprotein p with Alzheimer's pathology in human cortex, J. Alzheimers Dis. 15, 465-472. [22] Miller, J. A., Oldham, M. C., and Geschwind, D. H. (2008) A Systems Level Analysis of Transcriptional Changes in Alzheimer's Disease and Normal Aging, J. Neurosci. 28, 1410-1420. [23] Lu, T., Pan, Y., Kao, S.-Y., Li, C., Kohane, I., Chan, J., and Yankner, B. A. (2004) Gene regulation and DNA damage in the ageing human brain, Nature 429, 883-891. [24] Wirth, E. K., Conrad, M., Winterer, J., Wozny, C., Carlson, B. A., Roth, S., Schmitz, D., Bornkamm, G. W., Coppola, V., Tessarollo, L., Schomburg, L., Kohrle, J., Hatfield, D. L., and Schweizer, U. (2010) Neuronal selenoprotein expression is required for interneuron development and prevents seizures and neurodegeneration, FASEB J. 24, 844-852. [25] Chen, L., Hambright, W. S., Na, R., and Ran, Q. (2015) Ablation of the Ferroptosis Inhibitor Glutathione Peroxidase 4 in Neurons Results in Rapid Motor Neuron Degeneration and Paralysis, J. Biol. Chem. 290, 28097-28106. [26] Wirth, E. K., Bharathi, B. S., Hatfield, D., Conrad, M., Brielmeier, M., and Schweizer, U. (2014) Cerebellar hypoplasia in mice lacking selenoprotein biosynthesis in neurons, Biol. Trace Elem. Res. 158, 203-210. [27] Lim, Y. Y., Villemagne, V. L., Pietrzak, R. H., Ames, D., Ellis, K. A., Harrington, K., Snyder, P. J., Martins, R. N., Masters, C. L., Rowe, C. C., and Maruff, P. (2015) APOE epsilon4 moderates amyloid-related memory decline in preclinical Alzheimer's disease, Neurobiol. Aging 36, 1239-1244. [28] Saunders, A. M., Strittmatter, W. J., Schmechel, D., George-Hyslop, P. H., PericakVance, M. A., Joo, S. H., Rosi, B. L., Gusella, J. F., Crapper-MacLachlan, D. R., Alberts, M. J., and et al. (1993) Association of apolipoprotein E allele epsilon 4 with late-onset familial and sporadic Alzheimer's disease, Neurology 43, 1467-1472. [29] Corder, E. H., Saunders, A. M., Strittmatter, W. J., Schmechel, D. E., Gaskell, P. C., Small, G. W., Roses, A. D., Haines, J. L., and Pericak-Vance, M. A. (1993) Gene dose of apolipoprotein E type 4 allele and the risk of Alzheimer's disease in late onset families, Science 261, 921-923. [30] Burk, R. F., Hill, K. E., Motley, A. K., Winfrey, V. P., Kurokawa, S., Mitchell, S. L., and Zhang, W. (2014) Selenoprotein P and apolipoprotein E receptor-2 interact at the blood-brain barrier and also within the brain to maintain an essential selenium pool that protects against neurodegeneration, FASEB J. 28, 3579-3588.


11


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400

Page 12 of 15

[31] Chen, Y., Durakoglugil, M. S., Xian, X., and Herz, J. (2010) ApoE4 reduces glutamate receptor function and synaptic plasticity by selectively impairing ApoE receptor recycling, Proc. Natl. Acad. Sci. U. S. A. 107, 12011-12016. [32] Ulrich, V., Konaniah, E. S., Herz, J., Gerard, R. D., Jung, E., Yuhanna, I. S., Ahmed, M., Hui, D. Y., Mineo, C., and Shaul, P. W. (2014) Genetic variants of ApoE and ApoER2 differentially modulate endothelial function, Proc. Natl. Acad. Sci. U. S. A. 111, 13493-13498. [33] Rita Cardoso, B., Apolinario, D., da Silva Bandeira, V., Busse, A. L., Magaldi, R. M., Jacob-Filho, W., and Cozzolino, S. M. (2016) Effects of Brazil nut consumption on selenium status and cognitive performance in older adults with mild cognitive impairment: a randomized controlled pilot trial, Eur. J. Nutr. 55, 107-116. [34] Cardoso, B. R., Hare, D. J., Bush, A. I., Li, Q.-X., Fowler, C. J., Masters, C. L., Martins, R. N., Ganio, K., Lothian, A., Mukherjee, S., Kapp, E. A., and Roberts, B. R. (2017) Selenium Levels in Serum, Red Blood Cells, and Cerebrospinal Fluid of Alzheimer’s Disease Patients: A Report from the Australian Imaging, Biomarker & Lifestyle Flagship Study of Ageing (AIBL), J. Alzheimers Dis. DOI 10.3233/JAD-160622 [35] Lyons, G. H., Judson, G. J., Stangoulis, J. C., Palmer, L. T., Jones, J. A., and Graham, R. D. (2004) Trends in selenium status of South Australians, Med. J. Aust. 180, 383-386. [36] Thomson, C. D. (2004) Selenium and iodine intakes and status in New Zealand and Australia, Br. J. Nutr. 91, 661-672. [37] Newell, K. L., Hyman, B. T., Growdon, J. H., and Hedley-Whyte, E. T. (1999) Application of the National Institute on Aging (NIA)-Reagan Institute Criteria for the Neuropathological Diagnosis of Alzheimer Disease, J. Neuropathol. Exp. Neurol. 58, 1147-1155. [38] Hinojosa Reyes, L., Marchante Gayon, J. M., Garcia Alonso, J. I., and Sanz-Medel, A. (2003) Determination of selenium in biological materials by isotope dilution analysis with an octapole reaction system ICP-MS, J. Anal. At. Spectrom. 18, 11-16.

401


12

Page 13 of 15

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


402 403

Fig. 1: Selenium content in human brain fractions expressed as percentage distribution: A)

404

Control and B) Alzheimer’s disease brains. Selenium content in human brain fractions

405

stratified by: C) diagnosis; and D) APOE ε4 genotypes. AD: Alzheimer’s disease; CO:

406

control; PM / vesicular. Student t test: * p < 0.05; ** p ≤ 0.001; ✧Student t test performed

407

with log transformed data.

408


13


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 14 of 15

409

Table 1. Demographics for individuals from control (n = 33) and Alzheimer’s disease (n =

410

38) samples. Control

Alzheimer’s disease

p

Age (years)

70.81 ± 12.89

79.38 ± 9.95

0.003a

Sex (% female)

24.4

34.4

0.359b

APOE ε4 carriers (%)

45.5

60.5

0.204b

PMI (hours)

43.09 ±17.46

29.78 ±18.60

0.003a

411

Mean ± SD unless noted above as otherwise. a Student t-test; b Chi-square test. APOE ߝ4:

412

Apolipoprotein E epsilon 4, PMI: postmortem interval.

413 414

Table 2: Modelling the association of selenium concentration and distribution in brain by

415

subject demographics. Univariate analysis Alzheimer diseasea

APOE ε4 alleleb

Agec

β

p

β

p

β

p

Total

-11.228

0.210

-16.772

0.045

-0.415

0.249

Soluble

-10.061

0.000

5.259

0.045

-0.062

0.584

Peripheral

-1.058

3.472

-1.935

0.565

-0.351

0.019

Membrane

-0.048

0.214

-0.058

0.113

-0.002

0.156

FA insoluble

-1.830

0.022

0.371

0.616

-0.021

0.538

membrane / vesicular

416

a

417

and age as covariates.

418

b

419

and age as covariates

420

c

421

diagnostic groups as covariates.

Diagnostic group as dependent variable, APOE genotype (presence/absence of the ε4 allele)

APOE genotype (presence/absence of the ε4 allele) as dependent variable, diagnostic group

Age as dependent variable, APOE genotype (presence/absence of the ε4 allele) and

422 423


14

Page 15 of 15

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


The APOE ε4 allele is associated with lower selenium levels in the brain: implications in Alzheimer’s disease Bárbara R. Cardoso, Dominic J. Hare, Monica Lind, Catriona A. McLean, Colin L. Masters, Ashley I. Bush, Simon M. Laws, Irene Volitakis, Blaine R. Roberts


Îµ4 Allele Is Associated with Lower Selenium Levels in the Brain

Recommend Documents