Increased RNA levels of the 25 kDa synaptosomal associated protein in brain samples of adult patients with Down Syndrome.

Abstract

The synaptosomal associated protein of 25kDa (SNAP-25) is widely distributed in the brain and reduced in neurodegenerative diseases. In a previous paper we have shown reduced amounts of SNAP-25 protein in adult Down Syndrome (DS) brain. Neuronal cell death and downregulation at the transcriptional level may be responsible for the decrease. Therefore SNAP-25 mRNA levels were determined in frontal cortex and cerebellum of adult DS by a competitive reverse transcription-polymerase chain reaction. We found significantly increased mRNA levels in DS either related to 10 ng total RNA (P < 0.05 level in cerebellum: DS 2622 +/- 1081 attogr mean +/- SEM and controls 154 +/- 37 attogr. mean +/- SEM) or normalized versus the house keeping gene beta-actin (P < 0.05 level in frontal cortex: DS 1324 +/- 504 attogr. mean +/- SEM and control 131 +/- 32 attogr. mean +/- SEM; P<0.01 in cerebellum: DS 632 +/- 189 attogr. mean +/- SEM and control 21 +/- 2 attogr. mean +/- SEM). The main finding of this study shows elevated mRNA levels of SNAP-25 in adult DS brain whereas histological and protein-chemical evidence for decreased synaptosomal structures including SNAP-25 in a comparable cohort has been reported. We suggest compensatory mechanisms for the upregulation at the transcriptional level. We propose that SNAP-25 as many other brain proteins are regulated by protein stability rather than at the mRNA level.

• Authors: Susanne Greber-Platzer, Christine Fleischmann, Christa Nussbaumer, Nigel Cairns, Gert Lubec
• Journal: Neuroscience letters (Neurosci Lett) Vol. 336 Issue 2 Pg. 77-80 (Jan 16 2003) ISSN: 0304-3940 [Print] Ireland
• PMID: 12499044 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright 2002 Elsevier Science Ireland Ltd.

Chemical References

• Membrane Proteins
• Nerve Tissue Proteins
• SNAP25 protein, human
• Synaptosomal-Associated Protein 25
• RNA

Topics

• Cerebellum (metabolism)
• Cerebral Cortex (metabolism)
• Down Syndrome (genetics, metabolism)
• Female
• Gene Expression Regulation
• Humans
• Male
• Membrane Proteins (analysis, genetics, metabolism)
• Middle Aged
• Nerve Tissue Proteins (analysis, genetics, metabolism)
• Polymerase Chain Reaction
• RNA (analysis, genetics)
• Reference Values
• Synaptosomal-Associated Protein 25
• Transcription, Genetic