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Biomedical subjects

Christoph Münch

Publications and source records attributed to Christoph Münch.

5 recordsLinked to original sources

Tau isoforms expression in transgenic mouse model of amyotrophic lateral sclerosis.

Tau is a protein involved in regulation of microtubule stability, axonal differentiation and transport. Alteration of retrograde transport may lead to motor neuron degeneration. Thus alternative mRNA splicing and expression of tau isoforms were studied in a transgenic mouse model harboring the human SOD1 G93A mutation. The studies were performed on cortex, hippocampus and spinal cord of 64- and 120-day-old animals (presymptomatic and symptomatic stage) and wild type controls. Exon 10 was found in all studied tissues. The 2N isoform containing exons 2 and 3 (+2+3) and the 1N (+2-3) predominated over the 0N (-2-3) in brain regions of the studied mice. The 2N expression was significantly lower in cortex and hippocampus of symptomatic animals compared to analogue control tissues. The decrease in 2N expression resulted in lower levels of total tau mRNA and tau protein. No changes in tau expression were observed in spinal cord of studied animals.

Alternative Splicing↗

Frequency of a tau genotype in amyotrophic lateral sclerosis.

We investigated the susceptibility of the dinucleotide polymorphism A0 in the tau gene to amyotrophic lateral sclerosis (ALS). In 416 unrelated patients with ALS and 242 control subjects the A0/A0 genotype was not associated with the pooled sample of ALS cases. Subgroup analysis revealed that in sporadic ALS the A0 polymorphism was significantly overrepresented. There was no association of the A0/A0 genotype with the age and site of disease onset or the presence of dementia. The studied tau genotype may contribute to the multifactorial genetic background of ALS.

Amyotrophic Lateral Sclerosis↗

Heterozygous R1101K mutation of the DCTN1 gene in a family with ALS and FTD.

A heterozygous R1101K mutation of the p150 subunit of dynactin (DCTN1) is reported in a family with amyotrophic lateral sclerosis (ALS) and co-occurrence of frontotemporal dementia (FTD). Two members of our kindred were affected with motor neuron disease and two with dementia in an autosomal dominant pattern of inheritance. We excluded the involvement of the ALS and FTD-linked genes for copper/zinc superoxide dismutase (SOD1) and tau. The R1101K sequence alteration of the DCTN1 gene may predispose subjects to ALS and FTD.

Amyotrophic Lateral Sclerosis↗

Differential regulation of 5' splice variants of the glutamate transporter EAAT2 in an in vivo model of chemical hypoxia induced by 3-nitropropionic acid.

Defective glutamate uptake has been implicated as a pathogenic event of neuronal damage related to cerebral ischemia and hypoxia. In several models of ischemia-hypoxia, a reduced immunoreactivity and altered RNA expression of excitatory amino acid transporter 2 (EAAT2), the major excitatory amino acid transporter, have been reported. However, the gene regulation of EAAT2 under these conditions is incompletely understood. In this study, we investigated alternative splicing of EAAT2 in an in vivo mouse model of chemical hypoxia as induced by 3-nitropropionic acid (3-NP). The neurotoxin 3-NP is an inhibitor of mitochondrial energy production. Furthermore, it is known to inhibit glutamate reuptake directly, representing at least one of the mechanisms responsible for 3-NP-induced neurodegeneration. Here we report an expression analysis of five known (mEAAT2/5UT1-5) and two novel (mEAAT2/5UT6, -7) 5' splice variants of EAAT2 using semiquantitative PCR. The RNA expression was studied at 2, 12, 24, 48, and 72 hr and 7 days after 3-NP administration. mEAAT2/5UT4 and mEAAT2/5UT5 were up-regulated in the frontal cortex and down-regulated in the hippocampus 12-72 hr after chemical hypoxia. In the cerebellum, there was an increased expression of mEAAT2/5UT4 and a down-regulation of mEAAT2/5UT5. mEAAT2/5UT3 show a different regional expression pattern, being regulated in the cerebellum only. mEAAT2/5UT1-7 encoded distinct 5' regulatory sequences, including conserved elements of translational control. It is easily conceivable that expression alterations of 5' splice variants of EAAT2 are related to glutamate transporter malfunction after chemical hypoxia. Our findings contribute to the hypothesis that RNA splicing events can serve as a molecular mechanism of posthypoxic gene regulation.

Alternative Splicing↗

Ifosfamide encephalopathy presenting with asterixis.

CNS toxic effects of the antineoplastic agent ifosfamide (IFX) are frequent and include a variety of neurological symptoms that can limit drug use. We report a case of a 51-year-old man who developed severe, disabling negative myoclonus of the upper and lower extremities after the infusion of ifosfamide for plasmacytoma. He was awake, revealed no changes of mental status and at rest there were no further motor symptoms. Cranial magnetic resonance imaging and extensive laboratory studies failed to reveal structural lesions of the brain and metabolic abnormalities. An electroencephalogram showed continuous, generalized irregular slowing with admixed periodic triphasic waves indicating symptomatic encephalopathy. The administration of ifosfamide was discontinued and within 12 h the asterixis resolved completely. In the patient described, the presence of asterixis during infusion of ifosfamide, normal laboratory findings and imaging studies and the resolution of symptoms following the discontinuation of the drug suggest that negative myoclonus is associated with the use of IFX.

Dyskinesia, Drug-Induced↗