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Gender-Dependent Cholinergic System Alterations in a Phenylketonuria Model

Year 2024, Volume: 5 Issue: 2, 60 - 65, 20.09.2024

Abstract

Introduction
Phenylketonuria (PKU) is a rare inherited metabolic disorder characterized by a deficiency of the enzyme phenylalanine hydroxylase. The absence of this enzyme leads to elevated levels of phenylalanine in the blood, causing accumulation in the brain and resulting in permanent brain damage. To investigate the neurological effects of PKU, an experimental PKU model was developed, and cholinergic parameters were analyzed in brain tissue and serum from both female and male rats. In this study, serum BChE, AChE, and total ChE enzyme activities were examined, while AChE enzyme activity was specifically analyzed in hippocampal tissue.
Materials and Methods
In this study, brain tissue and serum samples were collected from female and male rats with an induced phenylketonuria model for analysis. BChE, AChE, and total ChE enzyme activities were measured in serum samples, while AChE enzyme activity was examined in hippocampal tissue. In the female PKU group, AChE activity was found to be 34.67±2.94 µU/mg, compared to 24.28±3.78 µU/mg in the female control group. Similarly, in the male PKU group, hippocampal AChE enzyme activity was 30.32±3.85 µU/mg, while it was 4.21±0.72 µU/mg in the male control group.
Results
Hippocampal AChE enzyme activity was significantly increased in both PKU groups compared to the control groups (Male ***p=0.0001; female *p=0.046). Serum analysis revealed decreased total serum cholinergic activity in both the female and male PKU groups compared with the control groups (**p≤0.002 and ***p≤0.0003, respectively). These results were consistent with findings from total serum cholinergic activity analysis. Additionally, the AChE enzyme activity in both the female and male PKU groups was decreased compared to their respective control groups (***p≤0.002 and ***p≤0.0006, respectively). It was also found that BChE enzyme activity in the serum of male rats in the PKU group was decreased compared to male rats in the control group (*p=0.038).
Conclusion
These findings indicate that the elements of the cholinergic system in the phenylketonuria model may vary according to gender. The observed changes in both brain tissue and serum provide new insights into the gender-dependent neurological effects of PKU.

References

  • 1. Scriber, C., Hyperphenylalaninemia: phenylalanine hydroxylase deficiency. The metabolic and molecular bases of inherited disease, 2001; 1667-1724.
  • 2. Blau, N., F.J. van Spronsen, and H.L. Levy, Phenylketonuria. The Lancet, 2010;376(9750): 1417-1427. Https://doi.org/10.1016/S0140-6736(10)60961-0
  • 3. Christ, S.E., et al., Executive function in early-treated phenylketonuria: profile and underlying mechanisms. Mol Genet Metab. 2010:99 Suppl 1:S22-32. Https://doi.org/10.1016/j.ymgme.2009.10.007
  • 4. Janzen, D. and M. Nguyen, Beyond executive function: non-executive cognitive abilities in individuals with PKU. Molecular Mol Genet Metab. 2010:99 Suppl 1:47-51. Https://doi.org/10.1016/j.ymgme.2009.10.009
  • 5. Moyle, J., et al., Meta-analysis of neuropsychological symptoms of adolescents and adults with PKU. Neuropsychol Rev. 2007;17(2):91-101. Https://doi.org/10.1007/s11065-007-9021-2
  • 6. Kaufman, S., An evaluation of the possible neurotoxicity of metabolites of phenylalanine. J Pediatr. 1989;114(5):895-900. Https://doi.org/10.1016/s0022-3476(89)80161-1
  • 7. Kaplay, S.S., Acetylcholinesterase and butyrylcholinesterase of developing human brain. Biol Neonate. 1976;28(1-2):65-73. Https://doi.org/10.1159/000240805
  • 8. Jope, R.S., et al., Cholinergic processes in blood samples from patients with major psychiatric disorders. Biol Psychiatry. 1985;20(12):1258-66. Https://doi.org/10.1016/0006-3223(85)90110-6
  • 9. Li, B., et al., Abundant tissue butyrylcholinesterase and its possible function in the acetylcholinesterase knockout mouse. J Neurochem. 2000;75(3):1320-31. Https://doi.org/10.1046/j.1471-4159.2000.751320.x
  • 10. Dienel, G.A. and N.F. Cruz, Biochemical, metabolic, and behavioral characteristics of immature chronic hyperphenylalanemic rats. Neurochem Res. 2016;41(1-2):16-32. Https://doi.org/10.1007/s11064-015-1678-y
  • 11. Cicek, C., et al., cAMP/PKA-CREB-BDNF signaling pathway in hippocampus of rats subjected to chemically-induced phenylketonuria. Metab Brain Dis. 2022;37(2):545-557. Https://doi.org/10.1007/s11011-021-00865-7
  • 12. Gok, M., et al., Altered levels of variant cholinesterase transcripts contribute to the imbalanced cholinergic signaling in Alzheimer’s and Parkinson’s disease. Front Mol Neurosci. 2022:15:941467. Https://doi.org/10.3389/ fnmol.2022.941467
  • 13. van Spronsen, F.J., et al., Key European guidelines for the diagnosis and management of patients with phenylketonuria. Lancet Diabetes Endocrinol. 2017;5(9):743-756. Https://doi.org/10.1016/S2213-8587(16)30320-5
  • 14. Bartus, R.T., et al., The cholinergic hypothesis of geriatric memory dysfunction. Science. 1982;217(4558):408-14. Https://doi.org/10.1126/science.7046051
  • 15. Gallagher, M. and P.J. Colombo, Ageing: the cholinergic hypothesis of cognitive decline. Curr Opin Neurobiol. 1995;5(2):161-8. Https://doi.org/10.1016/0959- 4388(95)80022-0
  • 16. Lawrence, A.D. and B.J. Sahakian, Alzheimer disease, attention, and the cholinergic system. Alzheimer Dis Assoc Disord, 1995;9 Suppl 2:43-9
  • 17. Silver, A., The biology of cholinesterases. 1974.
  • 18. Greenfield, S.A., A noncholinergic action of acetylcholinesterase (AChE) in the brain: from neuronal secretion to the generation of movement. Cell Mol Neurobiol. 1991;11(1):55-77. Https://doi.org/10.1007/BF00712800
  • 19. Appleyard, M.E., Secreted acetylcholinesterase: non-classical aspects of a classical enzyme. Trends Neurosci. 1992;15(12):485-90. Https://doi.org/10.1016/0166-2236(92)90100-m
  • 20. Balasubramanian, A. and C. Bhanumathy, Noncholinergic functions of cholinesterases. FASEB J. 1993;7(14):1354-1358. Https://doi.org/10.1096/fasebj.7.14.8224608
  • 21. Layer, P.G., Nonclassical roles of cholinesterases in the embryonic brain and possible links to Alzheimer disease. Alzheimer Dis Assoc Disord, 1995;9 Suppl 2:29-36. Https://doi.org/10.1097/00002093-199501002-00006
  • 22. Small, D.H., S. Michaelson, and G. Sberna, Non-classical actions of cholinesterases: role in cellular differentiation, tumorigenesis and Alzheimer’s disease. Neurochem Int., 1996;28(5-6):453-483. Https://doi.org/10.1016/0197-0186(95)00099-2
  • 23. Layer, P.G., et al., On the multifunctionality of cholinesterases. Chem Biol Interact. 2005:157-158:37-41. Https://doi.org/10.1016/j.cbi.2005.10.006
  • 24. Desmedt, J.E. and G. La Grutta, The effect of selective inhibition of pseudocholinesterase on the spontaneous and evoked activity of the cat’s cerebral cortex. J Physiol, 1957;136(1):20-40. Https://doi.org/10.1113/jphysiol.1957.sp005741
  • 25. Vigny, M., V. Gisiger, and J. Massoulie, “ Nonspecific” cholinesterase and acetylcholinesterase in rat tissues: molecular forms, structural and catalytic properties, and significance of the two enzyme systems. Proc Natl Acad Sci U S A. 1978;75(6):2588-92. Https://doi.org/10.1073/pnas.75.6.2588
  • 26. Giacobini, E., et al. Butyrylcholinesterase: is it important for cortical acetylcholine regulation. in Soc Neurosci. 1996.
  • 27. Soreq, H., E. Podoly, and M. Gok, Cholinesterases, in Encyclopedia of Molecular Pharmacology, S. Offermanns and W. Rosenthal, Editors. Springer International Publishing: Cham. 2021;451-458.
  • 28. Tsakiris, S., et al., Reduced acetylcholinesterase activity in erythrocyte membranes from patients with phenylketonuria. Clin Biochem. 2002;35(8):615-9. Https://doi.org/10.1016/s0009-9120(02)00381-8
  • 29. Scriver, C.R., The hyperphenylalaninemias. The metabolic and molecular bases of inherited disease, 1996:1015-1075.
  • 30. Bodur, E. and P.G. Layer, Counter-regulation of cholinesterases: Differential activation of PKC and ERK signaling in retinal cells through BChE knockdown. Biochimie. 2011;93(3):469-76. Https://doi.org/10.1016/j.biochi.2010.10.020
  • 31. Tsakiris, S., Effects of l-phenylalanine on acetylcholinesterase and Na+, K+-ATPase activities in adult and aged rat brain. Mech Ageing Dev. 2001;122(5):491-501. Https://doi.org/10.1016/s0047-6374(01)00217-2
  • 32. Cicek, C., Gok, M., & Bodur, E., Rat PKU Model Display Gender-Based Neuroinflammatory Changes: Proinflamatuary Cytokines and Lipid Peroxidation. . Muğla Sıtkı Koçman Üniversitesi Tıp Derg, 2024;11(1), 30-37. https://doi.org/10.47572/muskutd.1388547

Fenilketonüri Modelinde Cinsiyete Bağlı Kolinerjik Sistem Değişiklikleri

Year 2024, Volume: 5 Issue: 2, 60 - 65, 20.09.2024

Abstract

Giriş
Fenilketonüri (PKU), fenilalanin hidroksilaz enziminin eksikliği ile karakterize nadir bir kalıtsal metabolik bozukluktur. Bu enzimin yokluğu, kandaki fenilalanin düzeyinin artmasına ve beyinde birikmesine neden olarak kalıcı beyin hasarına yol açar. PKU'nun nörolojik etkilerini incelemek amacıyla geliştirilen deneysel PKU modeli, hem dişi hem de erkek sıçanlarda kolinerjik parametrelerin beyin dokusu ve serumda analiz edilmesini sağlamıştır. Bu çalışmada serumda BChE, AChE ve toplam ChE enzim aktiviteleri incelenmiş, hipokampal dokuda ise AChE enzim aktivitesi değerlendirilmiştir.
Materyal ve Metot
Çalışmada, fenilketonüri modeli oluşturulan dişi ve erkek sıçanlardan beyin dokusu ve serum örnekleri alınarak analizler gerçekleştirilmiştir. Serum örneklerinde BChE, AChE ve toplam ChE enzim aktiviteleri ölçülürken, hipokampal dokuda yalnızca AChE enzim aktivitesi incelenmiştir. Dişi PKU grubunda AChE aktivitesi 34.67±2.94 µU/mg olarak bulunmuşken, dişi kontrol grubunda bu değer 24.28±3.78 µU/mg olarak ölçülmüştür. Benzer şekilde, erkek PKU grubunda hipokampal AChE enzim aktivitesi 30.32±3.85 µU/mg iken, erkek kontrol grubunda 4.21±0.72 µU/mg olarak tespit edilmiştir.
Bulgular
PKU gruplarında hipokampal AChE enzim aktivitesi, kontrol gruplarına kıyasla anlamlı derecede artış göstermiştir (Erkek ***p=0.0001; dişi *p=0.046). Serum analizlerinde ise dişi ve erkek PKU gruplarında toplam serum kolinerjik aktivitesinin kontrol gruplarına göre azaldığı belirlenmiştir (**p≤0.002 ve ***p≤0.0003, sırasıyla). Toplam serum kolinerjik aktivitesi bulguları, bu sonuçlarla uyumlu olarak değerlendirilmiştir. Dişi ve erkek PKU gruplarının AChE enzim aktivitesi, kontrol gruplarına göre azalmış (**p≤0.002 ve ***p≤0.0006, sırasıyla) olup, erkek sıçanlarda BChE enzim aktivitesinin de PKU grubunda kontrol grubuna göre azaldığı bulunmuştur (*p=0.038).
Sonuç
Bu bulgular, fenilketonüri modelinde kolinerjik sistemin unsurlarının cinsiyete göre farklılık gösterebileceğini göstermektedir. Hem beyin dokusunda hem de serumda gözlemlenen bu değişiklikler, PKU'nun cinsiyete bağlı nörolojik etkileri üzerine yeni bakış açıları sunmaktadır.

References

  • 1. Scriber, C., Hyperphenylalaninemia: phenylalanine hydroxylase deficiency. The metabolic and molecular bases of inherited disease, 2001; 1667-1724.
  • 2. Blau, N., F.J. van Spronsen, and H.L. Levy, Phenylketonuria. The Lancet, 2010;376(9750): 1417-1427. Https://doi.org/10.1016/S0140-6736(10)60961-0
  • 3. Christ, S.E., et al., Executive function in early-treated phenylketonuria: profile and underlying mechanisms. Mol Genet Metab. 2010:99 Suppl 1:S22-32. Https://doi.org/10.1016/j.ymgme.2009.10.007
  • 4. Janzen, D. and M. Nguyen, Beyond executive function: non-executive cognitive abilities in individuals with PKU. Molecular Mol Genet Metab. 2010:99 Suppl 1:47-51. Https://doi.org/10.1016/j.ymgme.2009.10.009
  • 5. Moyle, J., et al., Meta-analysis of neuropsychological symptoms of adolescents and adults with PKU. Neuropsychol Rev. 2007;17(2):91-101. Https://doi.org/10.1007/s11065-007-9021-2
  • 6. Kaufman, S., An evaluation of the possible neurotoxicity of metabolites of phenylalanine. J Pediatr. 1989;114(5):895-900. Https://doi.org/10.1016/s0022-3476(89)80161-1
  • 7. Kaplay, S.S., Acetylcholinesterase and butyrylcholinesterase of developing human brain. Biol Neonate. 1976;28(1-2):65-73. Https://doi.org/10.1159/000240805
  • 8. Jope, R.S., et al., Cholinergic processes in blood samples from patients with major psychiatric disorders. Biol Psychiatry. 1985;20(12):1258-66. Https://doi.org/10.1016/0006-3223(85)90110-6
  • 9. Li, B., et al., Abundant tissue butyrylcholinesterase and its possible function in the acetylcholinesterase knockout mouse. J Neurochem. 2000;75(3):1320-31. Https://doi.org/10.1046/j.1471-4159.2000.751320.x
  • 10. Dienel, G.A. and N.F. Cruz, Biochemical, metabolic, and behavioral characteristics of immature chronic hyperphenylalanemic rats. Neurochem Res. 2016;41(1-2):16-32. Https://doi.org/10.1007/s11064-015-1678-y
  • 11. Cicek, C., et al., cAMP/PKA-CREB-BDNF signaling pathway in hippocampus of rats subjected to chemically-induced phenylketonuria. Metab Brain Dis. 2022;37(2):545-557. Https://doi.org/10.1007/s11011-021-00865-7
  • 12. Gok, M., et al., Altered levels of variant cholinesterase transcripts contribute to the imbalanced cholinergic signaling in Alzheimer’s and Parkinson’s disease. Front Mol Neurosci. 2022:15:941467. Https://doi.org/10.3389/ fnmol.2022.941467
  • 13. van Spronsen, F.J., et al., Key European guidelines for the diagnosis and management of patients with phenylketonuria. Lancet Diabetes Endocrinol. 2017;5(9):743-756. Https://doi.org/10.1016/S2213-8587(16)30320-5
  • 14. Bartus, R.T., et al., The cholinergic hypothesis of geriatric memory dysfunction. Science. 1982;217(4558):408-14. Https://doi.org/10.1126/science.7046051
  • 15. Gallagher, M. and P.J. Colombo, Ageing: the cholinergic hypothesis of cognitive decline. Curr Opin Neurobiol. 1995;5(2):161-8. Https://doi.org/10.1016/0959- 4388(95)80022-0
  • 16. Lawrence, A.D. and B.J. Sahakian, Alzheimer disease, attention, and the cholinergic system. Alzheimer Dis Assoc Disord, 1995;9 Suppl 2:43-9
  • 17. Silver, A., The biology of cholinesterases. 1974.
  • 18. Greenfield, S.A., A noncholinergic action of acetylcholinesterase (AChE) in the brain: from neuronal secretion to the generation of movement. Cell Mol Neurobiol. 1991;11(1):55-77. Https://doi.org/10.1007/BF00712800
  • 19. Appleyard, M.E., Secreted acetylcholinesterase: non-classical aspects of a classical enzyme. Trends Neurosci. 1992;15(12):485-90. Https://doi.org/10.1016/0166-2236(92)90100-m
  • 20. Balasubramanian, A. and C. Bhanumathy, Noncholinergic functions of cholinesterases. FASEB J. 1993;7(14):1354-1358. Https://doi.org/10.1096/fasebj.7.14.8224608
  • 21. Layer, P.G., Nonclassical roles of cholinesterases in the embryonic brain and possible links to Alzheimer disease. Alzheimer Dis Assoc Disord, 1995;9 Suppl 2:29-36. Https://doi.org/10.1097/00002093-199501002-00006
  • 22. Small, D.H., S. Michaelson, and G. Sberna, Non-classical actions of cholinesterases: role in cellular differentiation, tumorigenesis and Alzheimer’s disease. Neurochem Int., 1996;28(5-6):453-483. Https://doi.org/10.1016/0197-0186(95)00099-2
  • 23. Layer, P.G., et al., On the multifunctionality of cholinesterases. Chem Biol Interact. 2005:157-158:37-41. Https://doi.org/10.1016/j.cbi.2005.10.006
  • 24. Desmedt, J.E. and G. La Grutta, The effect of selective inhibition of pseudocholinesterase on the spontaneous and evoked activity of the cat’s cerebral cortex. J Physiol, 1957;136(1):20-40. Https://doi.org/10.1113/jphysiol.1957.sp005741
  • 25. Vigny, M., V. Gisiger, and J. Massoulie, “ Nonspecific” cholinesterase and acetylcholinesterase in rat tissues: molecular forms, structural and catalytic properties, and significance of the two enzyme systems. Proc Natl Acad Sci U S A. 1978;75(6):2588-92. Https://doi.org/10.1073/pnas.75.6.2588
  • 26. Giacobini, E., et al. Butyrylcholinesterase: is it important for cortical acetylcholine regulation. in Soc Neurosci. 1996.
  • 27. Soreq, H., E. Podoly, and M. Gok, Cholinesterases, in Encyclopedia of Molecular Pharmacology, S. Offermanns and W. Rosenthal, Editors. Springer International Publishing: Cham. 2021;451-458.
  • 28. Tsakiris, S., et al., Reduced acetylcholinesterase activity in erythrocyte membranes from patients with phenylketonuria. Clin Biochem. 2002;35(8):615-9. Https://doi.org/10.1016/s0009-9120(02)00381-8
  • 29. Scriver, C.R., The hyperphenylalaninemias. The metabolic and molecular bases of inherited disease, 1996:1015-1075.
  • 30. Bodur, E. and P.G. Layer, Counter-regulation of cholinesterases: Differential activation of PKC and ERK signaling in retinal cells through BChE knockdown. Biochimie. 2011;93(3):469-76. Https://doi.org/10.1016/j.biochi.2010.10.020
  • 31. Tsakiris, S., Effects of l-phenylalanine on acetylcholinesterase and Na+, K+-ATPase activities in adult and aged rat brain. Mech Ageing Dev. 2001;122(5):491-501. Https://doi.org/10.1016/s0047-6374(01)00217-2
  • 32. Cicek, C., Gok, M., & Bodur, E., Rat PKU Model Display Gender-Based Neuroinflammatory Changes: Proinflamatuary Cytokines and Lipid Peroxidation. . Muğla Sıtkı Koçman Üniversitesi Tıp Derg, 2024;11(1), 30-37. https://doi.org/10.47572/muskutd.1388547
There are 32 citations in total.

Details

Primary Language English
Subjects Metabolic Medicine
Journal Section Research Article
Authors

Çiğdem Çiçek 0000-0001-5481-4438

Müslüm Gök 0000-0003-2875-291X

Ebru Bodur 0000-0001-5829-5487

Publication Date September 20, 2024
Submission Date August 31, 2024
Acceptance Date September 6, 2024
Published in Issue Year 2024 Volume: 5 Issue: 2

Cite

AMA Çiçek Ç, Gök M, Bodur E. Gender-Dependent Cholinergic System Alterations in a Phenylketonuria Model. YIU Saglik Bil Derg. September 2024;5(2):60-65.