Increased protein levels of serotonin transporter in frontal cortex of patients with Down syndrome

• Published in: Neuroscience letters Vol. 296; no. 1; pp. 53 - 57
• Main Authors: Gulesserian, Talin, Engidawork, Ephrem, Cairns, Nigel, Lubec, Gert
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 15.12.2000; Elsevier
• Subjects: Adult; Alzheimer Disease - metabolism; Alzheimer's diseases; Biological and medical sciences; Brain; Carrier Proteins - metabolism; Cerebellum - metabolism; Chromosome aberrations; Down syndrome; Down Syndrome - metabolism; Female; Frontal Lobe - metabolism; Humans; Immunoreactivity; Male; Medical genetics; Medical sciences; Membrane Glycoproteins - metabolism; Membrane Transport Proteins; Middle Aged; Nerve Tissue Proteins; Neuron specific enolase; Phosphopyruvate Hydratase - metabolism; Reference Values; Serotonin - metabolism; Serotonin Plasma Membrane Transport Proteins; Serotonin transporter; Western blotting; Brain; Serotonin transporter; Alzheimer's diseases; Neuron specific enolase; Down syndrome; Immunoreactivity; Western blotting; Chromosomal aberration; Human; Trisomy; Serotonin; Alzheimer disease; Central nervous system; Neurotransmitter; Aneuploidy; Frontal cortex; Carrier protein; Brain (vertebrata)
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/S0304-3940(00)01624-4

Serotonin transporters (SERTs) are presynaptic proteins specialized for the clearance of serotonin from the synaptic cleft. A large body of evidence exists on altered platelet serotonin uptake and metabolism in Down syndrome (DS). Besides, dysregulation of SERTs expression have been reported in various complex behavioural traits and disorders including, neurodegenerative disorders. This prompted us to investigate SERT protein levels in adult brain specimens. Western blot analyses were performed in frontal cortex and cerebellum of aged controls and patients with DS and Alzheimer's disease (AD). The result revealed that frontal cortex SERT was significantly increased ( P<0.05) in DS, whereas in AD it was comparable to controls. In cerebellum, no significant difference was observed among the study populations. A remarkable difference was noted when SERT was normalized vs. neuron specific enolase (NSE), a neuronal marker. The increase in SERT/NSE was highly significant ( P<0.01) in DS frontal cortex compared to controls. Neither AD frontal cortex nor DS and AD cerebellum did show any significant difference. These findings indicate that a region specific alteration in SERT expression may exist in DS with AD-like pathology. As little is known about the status of serotenergic synaptic markers in DS brain, the findings may contribute to an effort made to delineate the underlying causes of serotonergic dysfunction in DS and the quest for therapeutic strategies. The study also suggest caution should be taken in applying data obtained from DS to model AD biochemical defects.