Dysbindin (DTNBP1) – A role in psychotic depression?

Previous studies yielded evidence for dysbindin (DTNBP1) to impact the pathogenesis of schizophrenia on the one hand and affective disorders such as bipolar or major depressive disorder (MDD) on the other. Thus, in the present study we investigated whether DTNBP1 variation was associated with psychotic depression as a severe clinical manifestation of MDD possibly constituting an overlapping phenotype between affective disorders and schizophrenia.A sample of 243 Caucasian inpatients with MDD (SCID-I) was genotyped for 12 SNPs spanning 92% of the DTNBP1 gene region. Differences in DTNBP1 genotype distributions across diagnostic subgroups of psychotic (N = 131) vs. non-psychotic depression were estimated by Pearson Chi² test and logistic regression analyses adjusted for age, gender, Beck Depression Inventory (BDI) and the Global Assessment of Functioning Scale (GAF).Overall, patients with psychotic depression presented with higher BDI and lower GAF scores expressing a higher severity of the illness as compared to depressed patients without psychotic features. Four DTNBP1 SNPs, particularly rs1997679 and rs9370822, and the corresponding haplotypes, respectively, were found to be significantly associated with the risk of psychotic depression in an allele-dose fashion.In summary, the present results provide preliminary support for dysbindin (DTNBP1) gene variation, particularly SNPs rs1997679 and rs9370822, to be associated with the clinical phenotype of psychotic depression suggesting a possible neurobiological mechanism for an intermediate trait on the continuum between affective disorders and schizophrenia.     

MELAS syndrome with m.4450 G > A mutation in mitochondrial tRNAMet gene

Mutations in the mitochondrial tRNA^Met gene have been reported in only five patients to date, all of whom presented with muscle weakness and exercise intolerance as signs of myopathy. We herein report the case of a 12-year-old girl with focal epilepsy since the age of eight years. At age 11, the patient developed sudden visual disturbances and headaches accompanied by recurrent, stroke-like episodes with lactic acidosis (pH 7.279, lactic acid 11.6?mmol/L). The patient frequently developed a delirious state, exhibited regression of intellectual ability. Brain magnetic resonance imaging revealed high-intensity signals on T2-weighted images of the left occipital lobe. Mitochondrial gene analysis revealed a heteroplasmic m.4450G?>?A mutation in the mitochondrial tRNA^Met. The heteroplasmic rate of the m.4450G?>?A mutation in blood, skin, urinary sediment, hair, saliva, and nail samples were 20, 38, 59, 41, 27, and 35%, respectively. The patient’s fibroblast showed an approximately 53% reduction in the oxygen consumption rate, compared to a control, and decreased complex I and IV activities. Stroke-like episodes, lactic acidosis, encephalopathy with brain magnetic resonance imaging findings, and declined mitochondrial function were consistent with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome. To our knowledge, the findings associated with this first patient with MELAS syndrome harboring the m.4450G?>?A mutation in mitochondrial tRNA^Met expand the phenotypic spectrum of tRNA^Met gene.     

A single center study: Aβ42/p-Tau<Subscript>181</Subscript> CSF ratio to discriminate AD from FTD in clinical setting

Abnormal levels of beta amyloid (Aβ42) and tau protein concentrations in the cerebral spinal fluid (CSF) have been largely described in Alzheimer’s disease (AD). Thus, CSF analysis of these biomarkers has been incorporated in recent AD diagnostic criteria, and it is increasingly performed for neurodegenerative dementia diagnostic workout in clinical setting. Nevertheless, the precise biomarkers CSF features in neurodegenerative dementia, either AD or Frontotemporal dementia (FTD), are still not fully clear today. This is mainly due to lack of CSF clear cutoff values due to a well-known intersite (but even intrasite) variability of CSF procedures, ranging from collection to analysis. Applying CSF biomarker ratios, rather than their single values could represent a useful tool, especially for the differential diagnosis of different forms of dementia. We explored clinical values of six CSF ratios (by combining Aβ42 and tau) in order to better discriminate between AD and FTD; we identified Aβ42/p-Tau₁₈₁ ratio as a potential good candidate for helping differentiating AD from FTD in the clinical practice.     

Receptor–receptor interactions in central cardiovascular regulation. Focus on neuropeptide/α<Subscript>2</Subscript>-adrenoreceptor interactions in the nucleus tractus solitarius

Summary. The nucleus tractus solitarii (NTS) is a key nucleus in central cardiovascular control. In this mechanism it is well known the role of the α₂-adrenoreceptors for the modulation of the autonomic pathways. Moreover a number of neuropeptides described in the NTS, including Neuropeptide Y (NPY), Galanin (GAL) and Angiotensin II (Ang II), have different roles in regulating the cardiovascular function within this nucleus. We show in this review several data which help to understand how these neuropeptides (NPY, GAL and Ang II) could modulate the cardiovascular responses mediated through α₂-adrenoreceptors in the NTS. Also we show for the first time the interactions between neuropeptides in the brain, specifically the interactions between NPY, GAL, and Ang II, and its functional relevance for central cardiovascular regulation. These data strength the role of neuropeptides on central autonomic control and provide some evidences to understand the neurochemical mechanisms involved in the cardiovascular responses from the NTS.     

Laudatio anlässlich der Vergabe des Alfred-Hauptmann-Preises 2019 an Professor Dr. med. Hajo Hamer,Dr. med. Johannes Lang und Professor Dr. rer. med. Karel Kostev

Clinical Epileptology -     

Charité 91. Schritte in eine neue Zeit

Clinical Epileptology - Auch über 160&nbsp;Jahre nach der ersten kasuistischen und über 60&nbsp;Jahre nach der ersten detaillierten syndromatologischen Beschreibung sind viele...     

Autophagy is involved in oral rAAV/Aβ vaccine-induced Aβ clearance in APP/PS1 transgenic mice

The imbalance between β-amyloid(Aβ) generation and clearance plays a fundamental role in the pathogenesis of Alzheimer 's disease(AD). The sporadic form of AD is characterized by an overall impairment in Aβ clearance. Immunotherapy targeting Aβ clearance is believed to be a promising approach and is under active clinical investigation. Autophagy is a conserved pathway for degrading abnormal protein aggregates and is crucial for Aβ clearance. We previously reported that oral vaccination with a recombinant AAV/Aβ vaccine increased the clearance of Aβ from the brain and improved cognitive ability in AD animal models, while the underlying mechanisms were not well understood. In this study, we first demonstrated that oral vaccination with rAAV/Aβ decreased the p62 level and up-regulated the LC3BII/LC3B-I ratio in APP/PS1 mouse brain, suggesting enhanced autophagy. Further, inhibition of the Akt/m TOR pathway may account for autophagy enhancement. We also found increased anti-Aβ antibodies in the sera of APP/PS1 mice with oralvaccination, accompanied by elevation of complement factors C1 q and C3 levels in the brain. Our results indicate that autophagy is closely involved in oral vaccination-induced Aβ clearance, and modulating the autophagy pathway may be an important strategy for AD prevention and intervention.