Advertisement

Journal of Inherited Metabolic Disease

, Volume 40, Issue 2, pp 227–235 | Cite as

Multicompartment analysis of protein-restricted phenylketonuric mice reveals amino acid imbalances in brain

  • Kara R. Vogel
  • Erland Arning
  • Teodoro Bottiglieri
  • K. Michael Gibson
Original Article

Abstract

Background

The mainstay of therapy for phenylketonuria (PKU) remains dietary protein restriction. Developmental and neurocognitive outcomes for patients, however, remain suboptimal. We tested the hypothesis that mice with PKU receiving protein-restricted diets would reveal disruptions of brain amino acids that shed light on these neurocognitive deficits.

Method

Phenylalanine hydroxylase-deficient (PKU) mice and parallel controls (both wild-type and heterozygous) were fed custom diets containing 18, 6, and 4 % protein for 3 weeks, after which tissues (brain, liver, sera) were collected for amino acid analysis profiling.

Results

Phenylalanine (phe) was increased in all tissues (p < 0.0001) of PKU mice and improved with protein restriction. In sera, decreased tyrosine (p < 0.01) was corrected (defined as not significantly different from the level in control mice receiving 18 % chow) with protein restriction, whereas protein restriction significantly increased many other amino acids. A similar trend for increased amino acid levels with protein restriction was also observed in liver. In brain, the effects of protein restriction on large neutral amino acids (LNAAs) were variable, with some deficit correction (threonine, methionine, glutamine) and no correction of tyrosine under any dietary paradigm. Protein restriction (4 % diet) in PKU mice significantly decreased lysine, arginine, taurine, glutamate, asparagine, and serine which had been comparable to control mice under 18 % protein intake.

Conclusion

Depletion of taurine, glutamate, and serine in the brain of PKU mice with dietary protein restriction may provide new insight into neurocognitive deficits of PKU.

Keywords

Taurine Amino Acid Level Protein Restriction Branch Chain Amino Acid Neurocognitive Deficit 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Abbreviations

Phe

Phenylalanine

tyr

Tyrosine

trp

Tryptophan

lys

Lysine

arg

Arginine

glu

Glutamate

asp

Aspartic acid

val

Valine

ile

Isoleucine

leu

Leucine

thr

Threonine

met

Methionine

gln

Glutamine

his

Histidine

gly

Glycine

pro

Proline

ala

Alanine

β-ala

β-alanine

ser

Serine

cit

Citrulline

tau

Taurine

PEA

Phosphoethanolamine

AADA

2-aminoadipic acid

AABA

α-aminobutyric acid

asn

Asparagine

cys

Cystine

orn

Ornithine

EA

Ethanolamine

BCAA

Branched chain amino acids (leu, ile, val)

LNAA

Large neutral amino acids, including phe, tyr, trp, thr, met, gln, his, val, ile, leu

Notes

Acknowledgments

The authors acknowledge the technical assistance of Ms. Erica Thorson.

Compliance with ethical standards

Conflict of interest

None.

Animal rights

All institutional and national guidelines for the care and use of laboratory animals were followed.

Supplementary material

10545_2016_9984_Fig5_ESM.gif (206 kb)
Supplemental Fig. 1

Concentrations of small neutral amino acids in brain, liver, and sera derived from control and PKU mice receiving 18 %, 6 %, and 4 % protein diets for 3 weeks. Abbreviations employed: gly, glycine; pro, proline; ala, alanine; β−ala, β-alanine; ser, serine. Other parameters are described in the legend for Fig. 1. β-alanine was not detectable in sera. (GIF 205 kb)

10545_2016_9984_MOESM1_ESM.tif (497 kb)
High resolution image (TIF 497 kb)
10545_2016_9984_Fig6_ESM.gif (182 kb)
Supplemental Fig. 2

Concentrations of other amino acids, including non-protein amino acids and metabolites, in brain, liver, and sera derived from control and PKU mice receiving 18 %, 6 %, and 4 % protein diets for 3 weeks. Abbreviations employed: cit, citrulline; tau, taurine; PEA, phosphoethanolamine; AADA, 2-aminoadipic acid; AABA, α-aminobutyric acid. AADA represents a metabolite on the lysine/saccharopine catabolic pathway. AABA is also recognized structurally as homoalanine, and is generated via transamination of 2-oxobutyrate, a metabolite in the isoleucine biosynthetic pathway. Other parameters are described in the legend for Fig. 1. Neither AADA nor AABA were detectable in sera. (GIF 182 kb)

10545_2016_9984_MOESM2_ESM.tif (458 kb)
High resolution image (TIF 457 kb)

References

  1. Berry SA, Brown C, Grant M, Greene CL, Jurecki E, Koch J, Moseley K, Suter R, van Calcar SC, Wiles J, Cederbaum S (2013) Newborn screening 50 years later: access issues faced by adults with PKU. Genet Med 15(8):591–599CrossRefPubMedPubMedCentralGoogle Scholar
  2. Brown CS, Lichter-Konecki U (2015) Phenylketonuria (PKU): a problem solved? Mol Genet Metab Rep 6:8–12CrossRefPubMedPubMedCentralGoogle Scholar
  3. Giller K, Huebbe P, Hennig S, Dose J, Pallauf K, Doering F, Rimbach G (2013) Beneficial effects of a 6-month dietary restriction are time-dependently abolished within 2 weeks or 6 months of refeeding-genome-wide transcriptome analysis in mouse liver. Free Radic Biol Med 61:170–178CrossRefPubMedGoogle Scholar
  4. Glushakov AV, Glushakova O, Varshney M, Bajpai LK, Sumners C, Laipis PJ, Embury JE, Baker SP, Otero DH, Dennis DM, Seubert CN, Martynyuk AE (2005) Long-term changes in glutamatergic synaptic transmission in phenylketonuria. Brain 128(Pt 2):300–307PubMedGoogle Scholar
  5. Gundersen V, Storm-Mathisen J, Bergersen LH (2015) Neuroglial transmission. Physiol Rev 95(3):695–726CrossRefPubMedGoogle Scholar
  6. Liang L, Gu X, Li D, Lu L (2011) The expression and phosphorylation of acid sensing ion channel 1a in the brain of a mouse model of phenylketonuria. Int J Neurosci 121(7):399–404CrossRefPubMedGoogle Scholar
  7. Liappis N, Pohl B, Weber HP, el-Karkani H (1986) Free amino acids in the saliva of children with phenylketonuria. Klin Padiatr 198(1):25–28CrossRefPubMedGoogle Scholar
  8. Martynyuk AE, Glushakov AV, Sumners C, Laipis PJ, Dennis DM, Seubert CN (2005) Impaired glutamatergic synaptic transmission in the PKU brain. Mol Genet Metab 86(Suppl 1):S34–S42CrossRefPubMedGoogle Scholar
  9. Mütze U, Thiele AG, Baerwald C, Ceglarek U, Kiess W, Beblo S (2016) Ten years of specialized adult care for phenylketonuria - a single-centre experience. Orphanet J Rare Dis 11:27CrossRefPubMedPubMedCentralGoogle Scholar
  10. Oja SS, Saransaari P (2015) Open questions concerning taurine with emphasis on the brain. Adv Exp Med Biol 803:409–413CrossRefPubMedGoogle Scholar
  11. Sawin EA, Murali SG, Ney DM (2014) Differential effects of low-phenylalanine protein sources on brain neurotransmitters and behavior in C57Bl/6-Pah(enu2) mice. Mol Genet Metab 111:452–461CrossRefPubMedPubMedCentralGoogle Scholar
  12. Schloesser A, Campbell G, Glüer CC, Rimbach G, Huebbe P (2015) Restriction on an energy-dense diet improves markers of metabolic health and cellular aging in mice through decreasing hepatic mTOR activity. Rejuvenation Res 18(1):30–39CrossRefPubMedPubMedCentralGoogle Scholar
  13. Schreiber JM, Pearl PL, Dustin I, Wiggs E, Barrios E, Wassermann EM, Gibson KM, Theodore WH (2016) Biomarkers in a taurine trial for succinic semialdehyde dehydrogenase deficiency. JIMD Rep. doi: 10.1007/8904_2015_524
  14. Sharman R, Sullivan K, Young R, McGill J (2015) Executive function in adolescents with PKU and their siblings: associations with biochemistry. Mol Genet Metab Rep 4:87–88CrossRefPubMedPubMedCentralGoogle Scholar
  15. Trefz FK, van Spronsen FJ, MacDonald A, Feillet F, Muntau AC, Belanger-Quintana A, Burlina A, Demirkol M, Giovannini M, Gasteyger C (2015) Management of adult patients with phenylketonuria: survey results from 24 countries. Eur J Pediatr 174(1):119–127CrossRefPubMedGoogle Scholar
  16. van Vliet D, Bruinenberg VM, Mazzola PN, van Faassen MH, de Blaauw P, Kema IP, Heiner-Fokkema MR, van Anholt RD, van der Zee EA, van Spronsen FJ (2015) Large neutral amino acid supplementation exerts its effect through three synergistic mechanisms: proof of principle in phenylketonuria mice. PLoS ONE 10(12):e0143833CrossRefPubMedPubMedCentralGoogle Scholar
  17. Vogel KR, Arning E, Wasek BL, Bottiglieri T, Gibson KM (2013a) Characterization of 2-(methylamino)alkanoic acid capacity to restrict blood–brain phenylalanine transport in Pah enu2 mice: preliminary findings. Mol Genet Metab 110(Suppl):S71–S78CrossRefPubMedPubMedCentralGoogle Scholar
  18. Vogel KR, Arning E, Wasek BL, Bottiglieri T, Gibson KM (2013b) Non-physiological amino acid (NPAA) therapy targeting brain phenylalanine reduction: pilot studies in PAHENU2 mice. J Inherit Metab Dis 36(3):513–523CrossRefPubMedGoogle Scholar
  19. Vogel KR, Ainslie GR, Phillips B, Arning E, Bottiglieri T, Shen DD, Gibson KM (2015) Physiological competition of brain phenylalanine accretion: initial pharmacokinetic analyses of aminoisobutyric and methylaminoisobutyric acids in Pahenu2−/− mice. Mol Genet Metab Rep 3:80–87CrossRefPubMedPubMedCentralGoogle Scholar
  20. Wesonga E, Shimony JS, Rutlin J, Grange DK, White DA (2016) Relationship between age and white matter integrity in children with phenylketonuria. Mol Genet Metab Rep 7:45–49CrossRefPubMedPubMedCentralGoogle Scholar
  21. Yano S, Moseley K, Fu X, Azen C (2016) Evaluation of tetrahydrobiopterin therapy with large neutral amino acid supplementation in phenylketonuria: effects on potential peripheral biomarkers, melatonin and dopamine, for brain monoamine neurotransmitters. PLoS ONE 11(8):e0160892CrossRefPubMedPubMedCentralGoogle Scholar

Copyright information

© SSIEM 2016

Authors and Affiliations

  • Kara R. Vogel
    • 1
  • Erland Arning
    • 2
  • Teodoro Bottiglieri
    • 2
  • K. Michael Gibson
    • 1
  1. 1.Division of Experimental and Systems Pharmacology, College of PharmacyWashington State UniversitySpokaneUSA
  2. 2.Kimberly H. Courtwright and Joseph W. Summers Institute of Metabolic DiseaseBaylor Research InstituteDallasUSA

Personalised recommendations