Disassembly of Tau fibrils by the human Hsp70 disaggregation machinery generates small seeding-competent species.

The accumulation of amyloid Tau aggregates is implicated in Alzheimer's disease (AD) and other tauopathies. Molecular chaperones are known to maintain protein homeostasis. Here, we show that an ATP-dependent human chaperone system disassembles Tau fibrils in vitro We found that this function is mediated by the core chaperone HSC70, assisted by specific cochaperones, in particular class B J-domain proteins and a heat shock protein 110 (Hsp110)-type nucleotide exchange factor (NEF). The Hsp70 disaggregation machinery processed recombinant fibrils assembled from all six Tau isoforms as well as Sarkosyl-resistant Tau aggregates extracted from cell cultures and human AD brain tissues, demonstrating the ability of the Hsp70 machinery to recognize a broad range of Tau aggregates. However, the chaperone activity released monomeric and small oligomeric Tau species, which induced the aggregation of self-propagating Tau conformers in a Tau cell culture model. We conclude that the activity of the Hsp70 disaggregation machinery is a double-edged sword, as it eliminates Tau amyloids at the cost of generating new seeds.

Bin1 directly remodels actin dynamics through its BAR domain.

Endocytic processes are facilitated by both curvature-generating BAR-domain proteins and the coordinated polymerization of actin filaments. Under physiological conditions, the N-BAR protein Bin1 has been shown to sense and curve membranes in a variety of cellular processes. Recent studies have identified Bin1 as a risk factor for Alzheimer's disease, although its possible pathological function in neurodegeneration is currently unknown. Here, we report that Bin1 not only shapes membranes, but is also directly involved in actin binding through its BAR domain. We observed a moderate actin bundling activity by human Bin1 and describe its ability to stabilize actin filaments against depolymerization. Moreover, Bin1 is also involved in stabilizing tau-induced actin bundles, which are neuropathological hallmarks of Alzheimer's disease. We also provide evidence for this effect in vivo, where we observed that downregulation of Bin1 in a Drosophila model of tauopathy significantly reduces the appearance of tau-induced actin inclusions. Together, these findings reveal the ability of Bin1 to modify actin dynamics and provide a possible mechanistic connection between Bin1 and tau-induced pathobiological changes of the actin cytoskeleton.

Idelalisib and rituximab in relapsed chronic lymphocytic leukemia.

BACKGROUND: Patients with relapsed chronic lymphocytic leukemia (CLL) who have clinically significant coexisting medical conditions are less able to undergo standard chemotherapy. Effective therapies with acceptable side-effect profiles are needed for this patient population. METHODS: In this multicenter, randomized, double-blind, placebo-controlled, phase 3 study, we assessed the efficacy and safety of idelalisib, an oral inhibitor of the delta isoform of phosphatidylinositol 3-kinase, in combination with rituximab versus rituximab plus placebo. We randomly assigned 220 patients with decreased renal function, previous therapy-induced myelosuppression, or major coexisting illnesses to receive rituximab and either idelalisib (at a dose of 150 mg) or placebo twice daily. The primary end point was progression-free survival. At the first prespecified interim analysis, the study was stopped early on the recommendation of the data and safety monitoring board owing to overwhelming efficacy. RESULTS: The median progression-free survival was 5.5 months in the placebo group and was not reached in the idelalisib group (hazard ratio for progression or death in the idelalisib group, 0.15; P<0.001). Patients receiving idelalisib versus those receiving placebo had improved rates of overall response (81% vs. 13%; odds ratio, 29.92; P<0.001) and overall survival at 12 months (92% vs. 80%; hazard ratio for death, 0.28; P=0.02). Serious adverse events occurred in 40% of the patients receiving idelalisib and rituximab and in 35% of those receiving placebo and rituximab. CONCLUSIONS: The combination of idelalisib and rituximab, as compared with placebo and rituximab, significantly improved progression-free survival, response rate, and overall survival among patients with relapsed CLL who were less able to undergo chemotherapy. (Funded by Gilead; ClinicalTrials.gov number, NCT01539512.).

Cellular and molecular modifier pathways in tauopathies: the big picture from screening invertebrate models.

Abnormal tau accumulations were observed and documented in post-mortem brains of patients affected by Alzheimer's disease (AD) long before the identification of mutations in the Microtubule-associated protein tau (MAPT) gene, encoding the tau protein, in a different neurodegenerative disease called Frontotemporal dementia and Parkinsonism linked to chromosome 17 (FTDP-17). The discovery of mutations in the MAPT gene associated with FTDP-17 highlighted that dysfunctions in tau alone are sufficient to cause neurodegeneration. Invertebrate models have been diligently utilized in investigating tauopathies, contributing to the understanding of cellular and molecular pathways involved in disease etiology. An important discovery came with the demonstration that over-expression of human tau in Drosophila leads to premature mortality and neuronal dysfunction including neurodegeneration, recapitulating some key neuropathological features of the human disease. The simplicity of handling invertebrate models combined with the availability of a diverse range of experimental resources make these models, in particular Drosophila a powerful invertebrate screening tool. Consequently, several large-scale screens have been performed using Drosophila, to identify modifiers of tau toxicity. The screens have revealed not only common cellular and molecular pathways, but in some instances the same modifier has been independently identified in two or more screens suggesting a possible role for these modifiers in regulating tau toxicity. The purpose of this review is to discuss the genetic modifier screens on tauopathies performed in Drosophila and C. elegans models, and to highlight the common cellular and molecular pathways that have emerged from these studies. Here, we summarize results of tau toxicity screens providing mechanistic insights into pathological alterations in tauopathies. Key pathways or modifiers that have been identified are associated with a broad range of processes including, but not limited to, phosphorylation, cytoskeleton organization, axonal transport, regulation of cellular proteostasis, transcription, RNA metabolism, cell cycle regulation, and apoptosis. We discuss the utility and application of invertebrate models in elucidating the cellular and molecular functions of novel and uncharacterized disease modifiers identified in large-scale screens as well as for investigating the function of genes identified as risk factors in genome-wide association studies from human patients in the post-genomic era. In this review, we combined and summarized several large-scale modifier screens performed in invertebrate models to identify modifiers of tau toxicity. A summary of the screens show that diverse cellular processes are implicated in the modification of tau toxicity. Kinases and phosphatases are the most predominant class of modifiers followed by components required for cellular proteostasis and axonal transport and cytoskeleton elements.

Idelalisib, an inhibitor of phosphatidylinositol 3-kinase p110δ, for relapsed/refractory chronic lymphocytic leukemia.

In a phase 1 trial, idelalisib (GS-1101, CAL-101), a selective inhibitor of the lipid kinase PI3Kδ, was evaluated in 54 patients with relapsed/refractory chronic lymphocytic leukemia (CLL) with adverse characteristics including bulky lymphadenopathy (80%), extensive prior therapy (median 5 [range 2-14] prior regimens), treatment-refractory disease (70%), unmutated IGHV (91%), and del17p and/or TP53 mutations (24%). Patients were treated at 6 dose levels of oral idelalisib (range 50-350 mg once or twice daily) and remained on continuous therapy while deriving clinical benefit. Idelalisib-mediated inhibition of PI3Kδ led to abrogation of Akt phosphorylation in patient CLL cells and significantly reduced serum levels of CLL-related chemokines. The most commonly observed grade ≥3 adverse events were pneumonia (20%), neutropenic fever (11%), and diarrhea (6%). Idelalisib treatment resulted in nodal responses in 81% of patients. The overall response rate was 72%, with 39% of patients meeting the criteria for partial response per IWCLL 2008 and 33% meeting the recently updated criteria of PR with treatment-induced lymphocytosis.(1,2) The median progression-free survival for all patients was 15.8 months. This study demonstrates the clinical utility of inhibiting the PI3Kδ pathway with idelalisib. Our findings support the further development of idelalisib in patients with CLL. These trials were registered at clinicaltrials.gov as #NCT00710528 and #NCT01090414.

Reticulon-like-1, the Drosophila orthologue of the hereditary spastic paraplegia gene reticulon 2, is required for organization of endoplasmic reticulum and of distal motor axons.

Several causative genes for hereditary spastic paraplegia encode proteins with intramembrane hairpin loops that contribute to the curvature of the endoplasmic reticulum (ER), but the relevance of this function to axonal degeneration is not understood. One of these genes is reticulon2. In contrast to mammals, Drosophila has only one widely expressed reticulon orthologue, Rtnl1, and we therefore used Drosophila to test its importance for ER organization and axonal function. Rtnl1 distribution overlapped with that of the ER, but in contrast to the rough ER, was enriched in axons. The loss of Rtnl1 led to the expansion of the rough or sheet ER in larval epidermis and elevated levels of ER stress. It also caused abnormalities specifically within distal portions of longer motor axons and in their presynaptic terminals, including disruption of the smooth ER (SER), the microtubule cytoskeleton and mitochondria. In contrast, proximal axon portions appeared unaffected. Our results provide direct evidence for reticulon function in the organization of the SER in distal longer axons, and support a model in which spastic paraplegia can be caused by impairment of axonal the SER. Our data provide a route to further understanding of both the role of the SER in axons and the pathological consequences of the impairment of this compartment.

Expression in drosophila of tandem amyloid ß peptides provides insights into links between aggregation and neurotoxicity.

The generation and subsequent aggregation of amyloid ß (Aß) peptides play a crucial initiating role in the pathogenesis of Alzheimer disease (AD). The two main isoforms of these peptides have 40 (Aß(40)) or 42 residues (Aß(42)), the latter having a higher propensity to aggregate in vitro and being the main component of the plaques observed in vivo in AD patients. We have designed a series of tandem dimeric constructs of these Aß peptides to probe the manner in which changes in the aggregation kinetics of Aß affect its deposition and toxicity in a Drosophila melanogaster model system. The levels of insoluble aggregates were found to be substantially elevated in flies expressing the tandem constructs of both Aß(40) and Aß(42) compared with the equivalent monomeric peptides, consistent with the higher effective concentration, and hence increased aggregation rate, of the peptides in the tandem repeat. A unique feature of the Aß(42) constructs, however, is the appearance of high levels of soluble oligomeric aggregates and a corresponding dramatic increase in their in vivo toxicity. The toxic nature of the Aß(42) peptide in vivo can therefore be attributed to the higher kinetic stability of the oligomeric intermediate states that it populates relative to those of Aß(40) rather than simply to its higher rate of aggregation.

Bimolecular fluorescence complementation and interaction of various Arabidopsis major intrinsic proteins expressed in yeast.

Tonoplast intrinsic proteins (TIPs) and plasma membrane intrinsic proteins (PIPs) form subgroups of plant major intrinsic proteins (MIPs) that channel water as well as various small neutral molecules across the tonoplast and plasma membrane. Most MIPs are believed to form homotetramers, while some plant PIPs have been shown to form heterotetramers composed of different isoforms. This study investigated in vivo molecular interactions between different Arabidopsis TIP isoforms and between TIPs and a PIP member. The interactions were assayed by bimolecular fluorescence complementation optimized for use in Saccharomyces cerevisiae as a heterologous expression system. Fluorescence of re-assembled Venus yellow fluorescent protein was monitored by fluorescence microscopy and flow cytometry. The results showed strong interactions between TIP1;2, TIP2;1 and TIP3;1. Surprisingly, the three TIP isoforms also interacted with PIP2;1. The potassium channel AKT1 was used as a negative control and exhibited no interaction with any of the MIPs. The observed interactions may play a role in targeting and regulation of MIPs in plants.

Ovine PrP transgenic Drosophila show reduced locomotor activity and decreased survival.

Drosophila have emerged as a model system to study mammalian neurodegenerative diseases. In the present study we have generated Drosophila transgenic for ovine PrP (prion protein) to begin to establish an invertebrate model of ovine prion disease. We generated Drosophila transgenic for polymorphic variants of ovine PrP by PhiC31 site-specific germ-line transformation under expression control by the bi-partite GAL4/UAS (upstream activating sequence) system. Site-specific transgene insertion in the fly genome allowed us to test the hypothesis that single amino acid codon changes in ovine PrP modulate prion protein levels and the phenotype of the fly when expressed in the Drosophila nervous system. The Arg(154) ovine PrP variants showed higher levels of PrP expression in neuronal cell bodies and insoluble PrP conformer than did His(154) variants. High levels of ovine PrP expression in Drosophila were associated with phenotypic effects, including reduced locomotor activity and decreased survival. Significantly, the present study highlights a critical role for helix-1 in the formation of distinct conformers of ovine PrP, since expression of His(154) variants were associated with decreased survival in the absence of high levels of PrP accumulation. Collectively, the present study shows that variants of the ovine PrP are associated with different spontaneous detrimental effects in ovine PrP transgenic Drosophila.

Metalloids: essential, beneficial or toxic? Major intrinsic proteins sort it out.

Major intrinsic proteins (MIPs) are a family of selective membrane channels comprising water-channelling aquaporins and glycerol-channelling aquaglyceroporins. Recently, several MIPs within all domains of life were shown to facilitate the diffusion of reduced and non-charged species of the metalloids silicon, boron, arsenic and antimony. Metalloids encompass a group of biologically important elements ranging from the essential to the highly toxic. Consequently, all organisms require efficient membrane transport systems to control the exchange of metalloids with the environment. Recent genetic evidence has demonstrated a crucial role for specific MIPs in metalloid homeostasis. We propose that specific MIPs represent an ancient and indispensable transport mechanism for metalloids, which suggests that they could be potential pharmacological targets.

Impact of the South Atlantic Anomaly on radiation exposure at flight altitudes during solar minimum.

The South Atlantic Anomaly (SAA) is a geographical region over the South Atlantic Ocean where the inner Van Allen radiation belt extends down particularly close to Earth. This leads to highly increased levels of ionizing radiation and related impacts on spacecraft in Low Earth Orbits, e.g., correspondingly increased radiation exposure of astronauts and electronic components on the International Space Station. According to an urban legend, the SAA is also supposed to affect the radiation field in the atmosphere even down to the altitudes of civil aviation. In order to identify and quantify any additional contributions to the omnipresent radiation exposure due to the Galactic Cosmic Radiation at flight altitudes, comprehensive measurements were performed crossing the geographical region of the SAA at an altitude of 13 km in a unique flight mission-Atlantic Kiss. No indication of increased radiation exposure was found.

Solanaceae XIPs are plasma membrane aquaporins that facilitate the transport of many uncharged substrates.

Major intrinsic proteins (MIPs) transport water and uncharged solutes across membranes in all kingdoms of life. Recently, an uncharacterized MIP subfamily was identified in the genomes of plants and fungi and named X Intrinsic Proteins (XIPs). Here, we describe the genetic features, localization, expression, and functions of a group of Solanaceae XIPs. XIP cDNA and gDNA were cloned from tobacco, potato, tomato, and morning glory. A conserved sequence motif in the first intron of Solanaceae XIPs initiates an RNA-processing mechanism that results in two splice variants (α and ß). When transiently or stably expressed in tobacco plants, yellow fluorescent protein-tagged NtXIP1;1α and NtXIP1;1ß were both localized in the plasma membrane. Transgenic tobacco lines expressing NtXIP1;1-promoter-GUS constructs and RT-PCR studies showed that NtXIP1;1 was expressed in all organs. The NtXIP1;1 promoter was mainly active in cell layers facing the environment in all above-ground tissues. Heterologous expression of Solanaceae XIPs in Xenopus laevis oocytes and various Saccharomyces cerevisiae mutants demonstrated that these isoforms facilitate the transport of bulky solutes, such as glycerol, urea, and boric acid. In contrast, permeability for water was undetectable. These data suggest that XIPs function in the transport of uncharged solutes across the cell plasma membrane in specific plant tissues, including at the interface between the environment and external cell layers.

CERAD-NAB and flexible battery based neuropsychological differentiation of Alzheimer's dementia and depression using machine learning approaches.

Depression (DEP) and dementia of the Alzheimer's type (DAT) represent the most common neuropsychiatric disorders in elderly patients. Accurate differential diagnosis is indispensable to ensure appropriate treatment. However, DEP can yet mimic cognitive symptoms of DAT and patients with DAT often also present with depressive symptoms, impeding correct diagnosis. Machine learning (ML) approaches could eventually improve this discrimination using neuropsychological test data, but evidence is still missing. We therefore employed Support Vector Machine (SVM), Naïve Bayes (NB), Random Forest (RF) and conventional Logistic Regression (LR) to retrospectively predict the diagnoses of 189 elderly patients (68 DEP and 121 DAT) based on either the well-established Consortium to Establish a Registry for Alzheimer's Disease neuropsychological assessment battery (CERAD-NAB) or a flexible battery approach (FLEXBAT). The best performing combination consisted of FLEXBAT and NB, correctly classifying 87.0% of patients as either DAT or DEP. However, all accuracies were similar across algorithms and test batteries (83.0% - 87.0%). Accordingly, our study is the first to show that common ML algorithms with their default parameters can accurately differentiate between patients clinically diagnosed with DAT or DEP using neuropsychological test data, but do not necessarily outperform conventional LR.

Uncovering specificity of endogenous TAU aggregation in a human iPSC-neuron TAU seeding model.

Tau pathobiology has emerged as a key component underlying Alzheimer's disease (AD) progression; however, human neuronal in vitro models have struggled to recapitulate tau phenomena observed in vivo. Here, we aimed to define the minimal requirements to achieve endogenous tau aggregation in functional neurons utilizing human induced pluripotent stem cell (hiPSC) technology. Optimized hiPSC-derived cortical neurons seeded with AD brain-derived competent tau species or recombinant tau fibrils displayed increases in insoluble, endogenous tau aggregates. Importantly, MAPT-wild type and MAPT-mutant hiPSC-neurons exhibited unique propensities for aggregation dependent on the seed strain rather than the repeat domain identity, suggesting that successful templating of the recipient tau may be driven by the unique conformation of the seed. The in vitro model presented here represents the first successful demonstration of combining human neurons, endogenous tau expression, and AD brain-derived competent tau species, offering a more physiologically relevant platform to study tau pathobiology.

Wiskott-Aldrich syndrome protein is an effector of Kit signaling.

The pleiotropic receptor tyrosine kinase Kit can provide cytoskeletal signals that define cell shape, positioning, and migration, but the underlying mechanisms are less well understood. In this study, we provide evidence that Kit signals through Wiskott-Aldrich syndrome protein (WASP), the central hematopoietic actin nucleation-promoting factor and regulator of the cytoskeleton. Kit ligand (KL) stimulation resulted in transient tyrosine phosphorylation of WASP, as well as interacting proteins WASP-interacting protein and Arp2/3. KL-induced filopodia in bone marrow-derived mast cells (BMMCs) were significantly decreased in number and size in the absence of WASP. KL-dependent regulation of intracellular Ca(2+) levels was aberrant in WASP-deficient BMMCs. When BMMCs were derived from WASP-heterozygous female mice using KL as a growth factor, the cultures eventually developed from a mixture of WASP-positive and -negative populations into a homogenous WASP-positive culture derived from the WASP-positive progenitors. Thus, WASP expression conferred a selective advantage to the development of Kit-dependent hematopoiesis consistent with the selective advantage of WASP-positive hematopoietic cells observed in WAS-heterozygous female humans. Finally, KL-mediated gene expression in wild-type and WASP-deficient BMMCs was compared and revealed that approximately 30% of all Kit-induced changes were WASP dependent. The results indicate that Kit signaling through WASP is necessary for normal Kit-mediated filopodia formation, cell survival, and gene expression, and provide new insight into the mechanism in which WASP exerts a strong selective pressure in hematopoiesis.

Developmental pattern of aquaporin expression in barley (Hordeum vulgare L.) leaves.

Aquaporins are multifunctional membrane channels which belong to the family of major intrinsic proteins (MIPs) and are best known for their ability to facilitate the movement of water. In the present study, earlier results from microarray experiments were followed up. These experiments had suggested that, in barley (Hordeum vulgare L.), aquaporin family members are expressed in distinct patterns during leaf development. Real-time PCR and in situ hybridization were used to analyse the level and tissue-distribution of expression of candidate aquaporins, focusing on plasma membrane and tonoplast intrinsic proteins (PIPs, TIPs). Water channel function of seven aquaporins, whose transcripts were the most abundant and the most variable, was tested through expression in yeast and, in part, through expression in oocytes. All PIP1 and PIP2 subfamily members changed in expression during leaf development, with expression being much higher or lower in growing compared with mature tissue. The same applied to those TIPs which were expressed at detectable levels. Specific roles during leaf development are proposed for particular aquaporins.

Amyloid formation under physiological conditions proceeds via a native-like folding intermediate.

Although most proteins can assemble into amyloid-like fibrils in vitro under extreme conditions, how proteins form amyloid fibrils in vivo remains unresolved. Identifying rare aggregation-prone species under physiologically relevant conditions and defining their structural properties is therefore an important challenge. By solving the folding mechanism of the naturally amyloidogenic protein beta-2-microglobulin at pH 7.0 and 37 degrees C and correlating the concentrations of different species with the rate of fibril elongation, we identify a specific folding intermediate, containing a non-native trans-proline isomer, as the direct precursor of fibril elongation. Structural analysis using NMR shows that this species is highly native-like but contains perturbation of the edge strands that normally protect beta-sandwich proteins from self-association. The results demonstrate that aggregation pathways can involve self-assembly of highly native-like folding intermediates, and have implications for the prevention of this, and other, amyloid disorders.

Cognitive decline in the behavioral variant of frontotemporal dementia.

BACKGROUND: Only a small number of studies on the natural disease course in behavioral variant frontotemporal dementia (bvFTD) have been conducted. This is surprising because knowledge about the progression of symptoms is a precondition for the design of clinical drug trials. METHODS: The aim of the present study was to examine the cognitive decline of 20 patients with mild bvFTD over one year using the Consortium to Establish a Registry for Alzheimer's Disease - Neuropsychological Assessment Battery (CERAD-NAB). RESULTS: Within an average follow-up interval of 13 months, patient scores declined significantly in the Mini-mental-State-Examination (MMSE) and the CERAD-NAB subtests of naming, verbal and nonverbal memory. No significant changes were found in the CERAD-NAB subtests of category fluency, recognition, and visuoconstruction. The average annualized decline on the MMSE was 4.0 ± 4.9 points. Ceiling effects were detected in Figures Copy, Word List Recognition and Modified Boston Naming Test. Though the included patient group was rather homogeneous regarding severity of dementia, the cognitive changes were very heterogeneous. CONCLUSION: Given the heterogeneity of cognitive decline, the design of a test battery for clinical trials in FTD will be challenging. A cognitive battery should definitely include the MMSE, Word List Learning and Word List Delayed Recall.

Identification of cis-acting determinants mediating the unconventional secretion of tau.

The deposition of tau aggregates throughout the brain is a pathological characteristic within a group of neurodegenerative diseases collectively termed tauopathies, which includes Alzheimer's disease. While recent findings suggest the involvement of unconventional secretory pathways driving tau into the extracellular space and mediating the propagation of the disease-associated pathology, many of the mechanistic details governing this process remain elusive. In the current study, we provide an in-depth characterization of the unconventional secretory pathway of tau and identify novel molecular determinants that are required for this process. Here, using Drosophila models of tauopathy, we correlate the hyperphosphorylation and aggregation state of tau with the disease-related neurotoxicity. These newly established systems recapitulate all the previously identified hallmarks of tau secretion, including the contribution of tau hyperphosphorylation as well as the requirement for PI(4,5)P2 triggering the direct translocation of tau. Using a series of cellular assays, we demonstrate that both the sulfated proteoglycans on the cell surface and the correct orientation of the protein at the inner plasma membrane leaflet are critical determinants of this process. Finally, we identify two cysteine residues within the microtubule binding repeat domain as novel cis-elements that are important for both unconventional secretion and trans-cellular propagation of tau.

Autophagy inhibition rescues structural and functional defects caused by the loss of mitochondrial chaperone Hsc70-5 in Drosophila.

We investigated in larval and adult Drosophila models whether loss of the mitochondrial chaperone Hsc70-5 is sufficient to cause pathological alterations commonly observed in Parkinson disease. At affected larval neuromuscular junctions, no effects on terminal size, bouton size or number, synapse size, or number were observed, suggesting that we studied an early stage of pathogenesis. At this stage, we noted a loss of synaptic vesicle proteins and active zone components, delayed synapse maturation, reduced evoked and spontaneous excitatory junctional potentials, increased synaptic fatigue, and cytoskeleton rearrangements. The adult model displayed ATP depletion, altered body posture, and susceptibility to heat-induced paralysis. Adult phenotypes could be suppressed by knockdown of dj-1ß, Lrrk, DCTN2-p50, DCTN1-p150, Atg1, Atg101, Atg5, Atg7, and Atg12. The knockdown of components of the macroautophagy/autophagy machinery or overexpression of human HSPA9 broadly rescued larval and adult phenotypes, while disease-associated HSPA9 variants did not. Overexpression of Pink1 or promotion of autophagy exacerbated defects.Abbreviations: AEL: after egg laying; AZ: active zone; brp: bruchpilot; Csp: cysteine string protein; dlg: discs large; eEJPs: evoked excitatory junctional potentials; GluR: glutamate receptor; H2O2: hydrogen peroxide; mEJP: miniature excitatory junctional potentials; MT: microtubule; NMJ: neuromuscular junction; PD: Parkinson disease; Pink1: PTEN-induced putative kinase 1; PSD: postsynaptic density; SSR: subsynaptic reticulum; SV: synaptic vesicle; VGlut: vesicular glutamate transporter.