Abstract (eng)
Introduction: Myeloperoxidase (MPO) is a member of the mammalian heme peroxidase superfamily and is mainly expressed in cells of the myeloid lineage. The protein plays a crucial role in oxidative burst of activated neutrophil granulocytes and consequently in degradation of potential pathogens by production of reactive oxygen species. Again, myeloperoxidase leaked or spilled to the intercellular space affects host tissue as well. However, this can cause serious damage to key structures especially within the central nervous system. A G>A substitution at position -463 within the promoter region of the MPO gene results in a 25-fold decreased expression in cis by disruption of a binding site for transcription factor SP1. At the one hand, this may decrease oxidative stress, whereas at the other hand it can also lead to worse developed host protection systems against oxidative stress because of lower baseline MPO levels.
Methods: MPO-463G>A genotyping was done by realtime-PCR and allelic discrimination using TaqMan® fluorescence labeled probes, results were validated by restriction fragment length polymorphism analysis. Assessment of serum MPO was conducted by means of enzyme linked immunosorbent assays (ELISA).
Results and Discussion: Baseline MPO levels did not differ between athletes and controls, whereas high serum MPO levels seem to affect rather athletes than participants of the control group regarding executional cognitive functions. Moreover, we found a statistically significant correlation between MPO and signs of cerebral atrophy (CSF-space accentuation). Furthermore, MPO levels and genotype are associated with subjective well-being and Geriatric Depression Scale scores. Regarding the latter, high serum MPO is a higher risk in participants featuring the MPO[-463A] allele. This conforms to previous findings, which indicate that low baseline MPO levels can lead to reduced defense mechanisms against oxidative stress.