Enhanced tau pathology via RanBP9 and Hsp90/Hsc70 chaperone complexes.

Accumulation of amyloid β (Aβ) and tau represent the two major pathological hallmarks of Alzheimer's disease (AD). Despite the critical importance of Aβ accumulation as an early event in AD pathogenesis, multiple lines of evidence indicate that tau is required to mediate Aβ-induced neurotoxic signals in neurons. We have previously shown that the scaffolding protein Ran-binding protein 9 (RanBP9), which is highly elevated in brains of AD and AD mouse models, both enhances Aβ production and mediates Aβ-induced neurotoxicity.

Cofilin-mediated Neuronal Apoptosis via p53 Translocation and PLD1 Regulation.

Amyloid β (Aβ) accumulation is an early event in the pathogenesis of Alzheimer's disease (AD), leading to mitochondrial and synaptic dysfunction, tau accumulation, and eventual neuronal death. While the p53 apoptotic pathway has clearly been associated with Aβ deposits and neuronal apoptosis, the critical upstream factors contributing to p53 activation in AD are not well understood. We have previously shown that cofilin activation plays a pivotal role in Aβ-induced mitochondrial and synaptic dysfunction.

Strain-dependence of the Angelman Syndrome phenotypes in Ube3a maternal deficiency mice.

Angelman syndrome (AS) is a genetic neurodevelopmental disorder, most commonly caused by deletion or mutation of the maternal allele of the UBE3A gene, with behavioral phenotypes and seizures as key features. Currently no treatment is available, and therapeutics are often ineffective in controlling AS-associated seizures. Previous publications using the Ube3a maternal deletion model have shown behavioral and seizure susceptibility phenotypes, however findings have been variable and merit characterization of electroencephalographic (EEG) activity.

Loss of function CHCHD10 mutations in cytoplasmic TDP-43 accumulation and synaptic integrity.

Although multiple CHCHD10 mutations are associated with the spectrum of familial and sporadic frontotemporal dementia-amyotrophic lateral sclerosis (FTD-ALS) diseases, neither the normal function of endogenous CHCHD10 nor its role in the pathological milieu (that is, TDP-43 pathology) of FTD/ALS have been investigated. In this study, we made a series of observations utilizing Caenorhabditis elegans models, mammalian cell lines, primary neurons and mouse brains, demonstrating that CHCHD10 normally exerts a protective role in mitochondrial and synaptic integrity as well as in the retention of nuclear TDP-43, whereas FTD/ALS-associated mutations (R15L and S59L) exhibit loss of function phenotypes in C. elegans genetic complementation assays and dominant negative activities in mammalian systems, resulting in mitochondrial/synaptic damage and cytoplasmic TDP-43 accumulation.

Activation of Ras-ERK Signaling and GSK-3 by Amyloid Precursor Protein and Amyloid Beta Facilitates Neurodegeneration in Alzheimer's Disease.

It is widely accepted that amyloid β (Aβ) generated from amyloid precursor protein (APP) oligomerizes and fibrillizes to form neuritic plaques in Alzheimer's disease (AD), yet little is known about the contribution of APP to intracellular signaling events preceding AD pathogenesis. The data presented here demonstrate that APP expression and neuronal exposure to oligomeric Aβ42 enhance Ras/ERK signaling cascade and glycogen synthase kinase 3 (GSK-3) activation. We find that RNA interference (RNAi)-directed knockdown of APP in B103 rat neuroblastoma cells expressing APP inhibits Ras-ERK signaling and GSK-3 activation, indicating that APP acts upstream of these signal transduction events.

Adding Recognition Discriminability Index to the Delayed Recall Is Useful to Predict Conversion from Mild Cognitive Impairment to Alzheimer's Disease in the Alzheimer's Disease Neuroimaging Initiative.

Ongoing research is focusing on the identification of those individuals with mild cognitive impairment (MCI) who are most likely to convert to Alzheimer's disease (AD). We investigated whether recognition memory tasks in combination with delayed recall measure of episodic memory and CSF biomarkers can predict MCI to AD conversion at 24-month follow-up. A total of 397 amnestic-MCI subjects from Alzheimer's disease Neuroimaging Initiative were included.

Effects of the synthetic neurosteroid ganaxolone on seizure activity and behavioral deficits in an Angelman syndrome mouse model.

Angelman syndrome (AS) is a rare neurogenetic disorder characterized by severe developmental delay, motor impairments, and epilepsy. GABAergic dysfunction is believed to contribute to many of the phenotypic deficits seen in AS. We hypothesized that restoration of inhibitory tone mediated by extrasynaptic GABA receptors could provide therapeutic benefit.

Potential Use of Flavopiridol in Treatment of Chronic Diseases.

This chapter describes the potential use of flavopiridol, a CDK inhibitor with anti-inflammatory and anti-proliferative activities, in the treatment of various chronic diseases. Flavopiridol arrests cell cycle progression in the G1 or G2 phase by inhibiting the kinase activities of CDK1, CDK2, CDK4/6, and CDK7. Additionally, it binds tightly to CDK9, a component of the P-TEFb complex (CDK9/cyclin T), and interferes with RNA polymerase II activation and associated transcription.

Ketone ester supplementation attenuates seizure activity, and improves behavior and hippocampal synaptic plasticity in an Angelman syndrome mouse model.

Angelman syndrome (AS) is a rare genetic and neurological disorder presenting with seizures, developmental delay, ataxia, and lack of speech. Previous studies have indicated that oxidative stress-dependent metabolic dysfunction may underlie the phenotypic deficits reported in the AS mouse model. While the ketogenic diet (KD) has been used to protect against oxidative stress and has successfully treated refractory epilepsy in AS case studies, issues arise due to its strict adherence requirements, in addition to selective eating habits and weight issues reported in patients with AS.

Targeting innate immunity for neurodegenerative disorders of the central nervous system.

Neuroinflammation is critically involved in numerous neurodegenerative diseases, and key signaling steps of innate immune activation hence represent promising therapeutic targets. This mini review series originated from the 4th Venusberg Meeting on Neuroinflammation held in Bonn, Germany, 7-9th May 2015, presenting updates on innate immunity in acute brain injury and chronic neurodegenerative disorders, such as traumatic brain injury and Alzheimer disease, on the role of astrocytes and microglia, as well as technical developments that may help elucidate neuroinflammatory mechanisms and establish clinical relevance. In this meeting report, a brief overview of physiological and pathological microglia morphology is followed by a synopsis on PGE2 receptors, insights into the role of arginine metabolism and further relevant aspects of neuroinflammation in various clinical settings, and concluded by a presentation of technical challenges and solutions when working with microglia and astrocyte cultures.

Potential role of PCTAIRE-2, PCTAIRE-3 and P-Histone H4 in amyloid precursor protein-dependent Alzheimer pathology.

Amyloid Precursor Protein (APP) is regulated in a mitosis-specific manner and plays a role in proliferative signaling in cells. Though APP-derived Aβ generation has a well-established role in neurodegeneration, the mechanistic role of APP in this process is not fully understood. Here, we performed an unbiased, comprehensive analysis of the phosphoproteome signature in APP-null neuroblastoma cells (B103) compared to those expressing APP-695 isoform (B103-695) to determine if APP expression affects protein phosphorylation.

Transcription factor Sp1 inhibition, memory, and cytokines in a mouse model of Alzheimer's disease.

Transcription factors are involved to varying extents in the health and survival of neurons in the brain and a better understanding of their roles with respect to the pathogenesis of Alzheimer's disease (AD) could lead to the development of additional treatment strategies. Sp1 is a transcription factor that responds to inflammatory signals occurring in the AD brain. It is known to regulate genes with demonstrated importance in AD, and we have previously found it upregulated in the AD brain and in brains of transgenic AD model mice.

Cortical auditory evoked responses of older adults with and without probable mild cognitive impairment.

Objective: Hearing loss has been well-documented as a risk factor for cognitive impairment, but the simple presence of hearing loss is not a sufficient predictor of cognitive decline. Although auditory behavioral research has not revealed an effective indicator of early cognitive impairment, a limited number of studies using cortical auditory evoked potentials (CAEPs) have shown promising evidence of an auditory neurophysiological indicator of early-stage cognitive impairment. The purpose of this study was to examine the P1-N1-P2 complex for indicators of cognitive impairment.

Dendritic and Langerhans cells respond to Aβ peptides differently: implication for AD immunotherapy.

Both wild-type and mutated beta-amyloid (Aβ) peptides can elicit an immune response when delivered subcutaneously. However, only mutated forms of Aβ can sensitize dendritic cells when administered intravenously or intraperitoneally. To understand the role of mutation and delivery routes in creating immune responses, and the function of dendritic cells as therapeutic agents, we used fluorescent-conjugated WT Aβ1-40 (WT40) and artificially mutated Aβ1-40 (22W40) peptides to treat dendritic and Langerhans cells from young and/or old mice at different time points.

The Role of nAChR and Calcium Signaling in Pancreatic Cancer Initiation and Progression.

Pancreatic cancer shows a strong correlation with smoking and the current therapeutic strategies have been relatively ineffective in improving the survival of patients. Efforts have been made over the past many years to understand the molecular events that drive the initiation and progression of pancreatic cancer, especially in the context of smoking. It has become clear that components of tobacco smoke not only initiate these cancers, especially pancreatic ductal adenocarcinomas (PDACs) through their mutagenic properties, but can also promote the growth and metastasis of these tumors by stimulating cell proliferation, angiogenesis, invasion and epithelial-mesenchymal transition.

Calorie restriction does not restore brain mitochondrial function in P301L tau mice, but it does decrease mitochondrial F0F1-ATPase activity.

Calorie restriction (CR) has been shown to increase lifespan and delay aging phenotypes in many diverse eukaryotic species. In mouse models of Alzheimer's disease (AD), CR has been shown to decrease amyloid-beta and hyperphosphorylated tau levels and preserve cognitive function. Overexpression of human mutant tau protein has been shown to induce deficits in mitochondrial electron transport chain complex I activity.

An optimized InCell Western screening technique identifies hexachlorophene as a novel potent TDP43 targeting drug.

TAR DNA binding protein (TDP43) is a DNA- and RNA-binding protein that is implicated in several neurodegenerative disorders termed as "TDP43 proteinopathies" including Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS) and fronto-temporal lobe dementia (FTLD). We have developed an InCell Western (ICW) technique for screening TDP targeting drugs in 96 well plates. We tested 281 compounds and identified a novel compound hexachlorophene (referred to as B10) that showed potent reduction in TDP43 levels.

Identifiable biomarker and treatment development using HIV-1 long term non-progressor sera.

Background: HIV-infected long-term non-progressor (LTNP) subjects can prevent viral replication and may harbor useful information for the development of both antibody and active vaccination treatments. In this study we used LTNP sera to examine the epitopes presented to the gp160 protein, and from this procedure we hope to elucidate potential biomarkers pertaining to the level of resistance a patient may have in developing AIDS after infection with HIV. We used five clinical sera samples from LTNP patients to identify common epitopes by ELISA; peptides with high binding to sera were selected and analyzed for conservation among HIV clades.

Reelin supplementation recovers synaptic plasticity and cognitive deficits in a mouse model for Angelman syndrome.

The Reelin signaling pathway is implicated in processes controlling synaptic plasticity and hippocampus-dependent learning and memory. A single direct in vivo application of Reelin enhances long-term potentiation, increases dendritic spine density and improves associative and spatial learning and memory. Angelman syndrome (AS) is a neurological disorder that presents with an overall defect in synaptic function, including decreased long-term potentiation, reduced dendritic spine density, and deficits in learning and memory, making it an attractive model in which to examine the ability of Reelin to recover synaptic function and cognitive deficits.

Isoform-selective Genetic Inhibition of Constitutive Cytosolic Hsp70 Activity Promotes Client Tau Degradation Using an Altered Co-chaperone Complement.

The constitutively expressed heat shock protein 70 kDa (Hsc70) is a major chaperone protein responsible for maintaining proteostasis, yet how its structure translates into functional decisions regarding client fate is still unclear. We previously showed that Hsc70 preserved aberrant Tau, but it remained unknown if selective inhibition of the activity of this Hsp70 isoform could facilitate Tau clearance. Using single point mutations in the nucleotide binding domain, we assessed the effect of several mutations on the functions of human Hsc70.

Immunostaining analysis of tissue cultured cells and tissue sections using phospho-Histone H3 (Serine 10) antibody.

Post-translational modifications of histones play an important role in regulation of gene expression through condensation and decondensation of chromatin structure. These modifications include acetylation, methylation, phosphorylation and ubiquitination. Phosphorylation on histones is associated with cellular responses such as DNA damage, transcription, chromatin compaction and mitosis or meiosis.

RanBP9 at the intersection between cofilin and Aβ pathologies: rescue of neurodegenerative changes by RanBP9 reduction.

Molecular pathways underlying the neurotoxicity and production of amyloid β protein (Aβ) represent potentially promising therapeutic targets for Alzheimer's disease (AD). We recently found that overexpression of the scaffolding protein RanBP9 increases Aβ production in cell lines and in transgenic mice while promoting cofilin activation and mitochondrial dysfunction. Translocation of cofilin to mitochondria and induction of cofilin-actin pathology require the activation/dephosphorylation of cofilin by Slingshot homolog 1 (SSH1) and cysteine oxidation of cofilin.

Slingshot-Cofilin activation mediates mitochondrial and synaptic dysfunction via Aβ ligation to β1-integrin conformers.

The accumulation of amyloid-β protein (Aβ) is an early event associated with synaptic and mitochondrial damage in Alzheimer's disease (AD). Recent studies have implicated the filamentous actin (F-actin) severing protein, Cofilin, in synaptic remodeling, mitochondrial dysfunction, and AD pathogenesis. However, whether Cofilin is an essential component of the AD pathogenic process and how Aβ impinges its signals to Cofilin from the neuronal surface are unknown.

Anti-human α-synuclein N-terminal peptide antibody protects against dopaminergic cell death and ameliorates behavioral deficits in an AAV-α-synuclein rat model of Parkinson's disease.

The protein α-synuclein (α-Syn) has a central role in the pathogenesis of Parkinson's disease (PD) and immunotherapeutic approaches targeting this molecule have shown promising results. In this study, novel antibodies were generated against specific peptides from full length human α-Syn and evaluated for effectiveness in ameliorating α-Syn-induced cell death and behavioral deficits in an AAV-α-Syn expressing rat model of PD. Fisher 344 rats were injected with rAAV vector into the right substantia nigra (SN), while control rats received an AAV vector expressing green fluorescent protein (GFP).