Rebalancing the motor circuit restores movement in a Caenorhabditis elegans model for TDP-43 toxicity.

Amyotrophic lateral sclerosis can be caused by abnormal accumulation of TAR DNA-binding protein 43 (TDP-43) in the cytoplasm of neurons. Here, we use a C. elegans model for TDP-43-induced toxicity to identify the biological mechanisms that lead to disease-related phenotypes. By applying deep behavioral phenotyping and subsequent dissection of the neuromuscular circuit, we show that TDP-43 worms have profound defects in GABA neurons. Moreover, acetylcholine neurons appear functionally silenced. Enhancing functional output of repressed acetylcholine neurons at the level of, among others, G-protein-coupled receptors restores neurotransmission, but inefficiently rescues locomotion. Rebalancing the excitatory-to-inhibitory ratio in the neuromuscular system by simultaneous stimulation of the affected GABA- and acetylcholine neurons, however, not only synergizes the effects of boosting individual neurotransmitter systems, but instantaneously improves movement. Our results suggest that interventions accounting for the altered connectome may be more efficient in restoring motor function than those solely focusing on diseased neuron populations.

Thrombotic microangiopathy after traumatic brain injury: A case report and review of the literature.

Key Clinical Message: This case report supports that trauma can rarely cause thrombotic microangiopathy (TMA). Early recognition is important due to a high mortality of untreated TMA, but diagnosis can be delayed by attributing lab abnormalities as due to blood loss. Abstract: Major trauma can provoke coagulopathy, ranging from hypo- to hypercoagulation. Thrombotic microangiopathy (TMA), characterized by hemolytic anemia, renal failure, thrombocytopenia, and intravascular hemolysis, results in bleeding tendency but also microvascular thrombosis. We report a rare case of isolated traumatic brain injury leading to TMA treated with plasmapheresis.

Deletion of SERF2 in mice delays embryonic development and alters amyloid deposit structure in the brain.

In age-related neurodegenerative diseases, like Alzheimer's and Parkinson's, disease-specific proteins become aggregation-prone and form amyloid-like deposits. Depletion of SERF proteins ameliorates this toxic process in worm and human cell models for diseases. Whether SERF modifies amyloid pathology in mammalian brain, however, has remained unknown. Here, we generated conditional Serf2 knockout mice and found that full-body deletion of Serf2 delayed embryonic development, causing premature birth and perinatal lethality. Brain-specific Serf2 knockout mice, on the other hand, were viable, and showed no major behavioral or cognitive abnormalities. In a mouse model for amyloid-ß aggregation, brain depletion of Serf2 altered the binding of structure-specific amyloid dyes, previously used to distinguish amyloid polymorphisms in the human brain. These results suggest that Serf2 depletion changed the structure of amyloid deposits, which was further supported by scanning transmission electron microscopy, but further study will be required to confirm this observation. Altogether, our data reveal the pleiotropic functions of SERF2 in embryonic development and in the brain and support the existence of modifying factors of amyloid deposition in mammalian brain, which offer possibilities for polymorphism-based interventions.

The cellular modifier MOAG-4/SERF drives amyloid formation through charge complementation.

While aggregation-prone proteins are known to accelerate aging and cause age-related diseases, the cellular mechanisms that drive their cytotoxicity remain unresolved. The orthologous proteins MOAG-4, SERF1A, and SERF2 have recently been identified as cellular modifiers of such proteotoxicity. Using a peptide array screening approach on human amyloidogenic proteins, we found that SERF2 interacted with protein segments enriched in negatively charged and hydrophobic, aromatic amino acids. The absence of such segments, or the neutralization of the positive charge in SERF2, prevented these interactions and abolished the amyloid-promoting activity of SERF2. In protein aggregation models in the nematode worm Caenorhabditis elegans, protein aggregation and toxicity were suppressed by mutating the endogenous locus of MOAG-4 to neutralize charge. Our data indicate that MOAG-4 and SERF2 drive protein aggregation and toxicity by interactions with negatively charged segments in aggregation-prone proteins. Such charge interactions might accelerate primary nucleation of amyloid by initiating structural changes and by decreasing colloidal stability. Our study points at charge interactions between cellular modifiers and amyloidogenic proteins as potential targets for interventions to reduce age-related protein toxicity.

Aging, microglia and cytoskeletal regulation are key factors in the pathological evolution of the APP23 mouse model for Alzheimer's disease.

Aging is the key risk factor for Alzheimer's disease (AD). In addition, the amyloid-beta (Aß) peptide is considered a critical neurotoxic agent in AD pathology. However, the connection between these factors is unclear. We aimed to provide an extensive characterization of the gene expression profiles of the amyloidosis APP23 model for AD and control mice and to evaluate the effect of aging on these profiles. We also correlated our findings to changes in soluble Aß-levels and other pathological and symptomatic features of the model. We observed a clear biphasic expression profile. The first phase displayed a maturation profile, which resembled features found in young carriers of familial AD mutations. The second phase reflected aging processes and showed similarities to the progression of human AD pathology. During this phase, the model displayed a clear upregulation of microglial activation and lysosomal pathways and downregulation of neuron differentiation and axon guidance pathways. Interestingly, the changes in expression were all correlated to aging in general, but appeared more extensive/accelerated in APP23 mice.

eEduHeart I: A Multicenter, Randomized, Controlled Trial Investigating the Effectiveness of a Cardiac Web-Based eLearning Platform - Rationale and Study Design.

OBJECTIVES: Cardiac telerehabilitation includes, in its most comprehensive format, telemonitoring, telecoaching, social interaction, and eLearning. The specific role of eLearning, however, was seldom assessed. The aim of eEduHeart I is to investigate the medium-term effectiveness of the addition of a cardiac web-based eLearing platform to conventional cardiac care. METHODS: In this prospective, multicenter randomized, controlled trial, 1,000 patients with coronary artery disease will be randomized 1:1 to an intervention group (receiving 1-month unrestricted access to the cardiac eLearning platform in addition to conventional cardiac care) or to conventional cardiac care alone. The primary endpoint is health-related quality of life, assessed by the HeartQoL questionnaire at the 1- and 3-month follow-ups. Secondary endpoints include pathology-specific knowledge and self-reported eLearning platform user experience. Data on the eLearning platform usage will be gathered through web logging during the study period. RESULTS: eEduHeart I will be one of the first studies to report on the added value of eLearning. CONCLUSIONS: If the intervention is proven effective, current cardiac telerehabilitation programs can be augmented by including eLearning, too. The platform can then be used as a model for other chronic diseases in which patient education plays a key role.

Signal loss due to oligomerization in ELISA analysis of amyloid-beta can be recovered by a novel sample pre-treatment method.

According to the predominant theories, soluble amyloid-beta (Aß) aggregates are the principal neurotoxic agents in Alzheimer's disease pathology, making them a popular target for the development of therapeutics and diagnostic markers. One of the most commonly used methods for determining the concentration of Aß is ELISA. However, ELISA was developed for monomeric proteins and may be ill-suited for detecting aggregates. Therefore, we investigated the effect of aggregation on the ELISA measurement and developed a novel chemical pre-treatment method, designed to disaggregate Aß peptides, to improve the ELISA measurement of the total Aß concentration. Synthetic Aß40 monomers, Aß42 oligomers and biological samples from mice and humans were subjected to a chemical pre-treatment protocol with: trifluoroacetic acid (TFA), formic acid (FA) or hexafluoroisopropanol (HFIP) prior to ELISA analysis. In our study we have shown that: •Aß oligomerization leads to epitope masking and steric hindrance and results in an underestimation of the total Aß content with ELISA.•Chemically pre-treating samples to disaggregate oligomers can (partially) recover the signal loss.•This novel sample pre-treatment method could provide a more accurate ELISA measurement of the total Aß concentration in samples with a high oligomer content.

Neuropeptides in Alzheimer's disease: from pathophysiological mechanisms to therapeutic opportunities.

Neuropeptides are found throughout the entire nervous system where they can act as neurotransmitter, neuromodulator or neurohormone. In those functions, they play important roles in the regulation of cognition and behavior. In brain disorders like Alzheimer's disease (AD), where abnormal cognition and behavior are observed, the study of neuropeptides is particularly interesting since altered neuropeptides can function as biomarkers or as targets for new medication. In this article neuropeptides with relevance to AD are listed and their influence on cognitive and behavioral disturbances is discussed. Findings from human cerebrospinal fluid and brain tissue, and AD mouse models are described and related to the pathophysiology and symptomatology of the disease. In the past, clinical trials with neuropeptides have often failed due to insufficient delivery to the brain. Therefore, new strategies to target the brain with peptide drugs are also covered.