A culture model for the assessment of phenylalanine neurotoxicity in phenylketonuria

Abstract Objective Phenylketonuria (PKU) is caused by a specific mutation of the phenylalanine hydroxylase (PAH) gene. The deficiency PAH results in high levels (Phe), low tyrosine (Tyr), and reduced catecholamine neurotransmitters. majority PKU patients, if untreated, develop severe mental retardation. contribution Phe Tyr retardation largely unknown. In this study, we used organic hippocampal slice cultures an optimized medium as adequate culture model to decipher precise role on synaptic glial integrity PKU. hippocampus closely related learning memory neurotransmitter can be neglected since these neurotransmitters do not derive from hippocampus. Cultures exposed physiological concentrations were compared with doses Phe/Tyr, cerebral fluid patients. Methods Using capillary western blot analysis immunohistochemistry, followed quantitative image analysis, tested expression various pre- postsynaptic proteins (PSD95, synaptopodin, SNAP25, synaptophysin), cell markers (GFAP, Iba1, P2Y12, CD68, C3b), morphology cells. Results We found downregulation protein PSD95 presynaptic SNAP25 presence high/low Phe/Tyr after 3 weeks, which, then however, recovered 6 weeks culture. Furthermore, no change pattern was observed. Conclusion Our show that levels/low alone are unlikely substantially contribute direct neurotoxic potency Phe/low almost negligible effects transient. transient character unchanged points derivate neurotransmitters, rather than