The secreted neurotrophin Spatzle 3 promotes glial morphogenesis and supports neuronal survival and function

Most glial functions depend on establishing intimate morphological relationships with neurons. Significant progress has been made in understanding neuron-glia signaling at synaptic and axonal contacts, but how glia support neuronal cell bodies is unclear. Here we explored the growth and functions of Drosophila cortex glia (which associate almost exclusively with neuronal cell bodies) to understand glia-soma interactions. We show that cortex glia tile with one another and with astrocytes to establish unique central nervous system (CNS) spatial domains that actively restrict glial growth, and selective ablation of cortex glia causes animal lethality. In an RNAi-based screen, we identified alphaSNAP (soluble NSF [N-ethylmalemeide-sensitive factor] attachment protein alpha) and several components of vesicle fusion and recycling machinery as essential for the maintenance of cortex glial morphology and continued contact with neurons. Interestingly, loss of the secreted neurotrophin Spatzle 3 (Spz3) phenocopied alphaSNAP phenotypes, which included loss of glial ensheathment of neuron cell bodies, increased neuronal cell death, and defects in animal behavior. Rescue experiments suggest that Spz3 can exert these effects only over very short distances. This work identifies essential roles for glial ensheathment of neuronal cell bodies in CNS homeostasis as well as Spz3 as a novel signaling factor required for maintenance of cortex glial morphology and neuron-glia contact

An Examination of the Most Recent Episode of Molly Use Among College Students

OBJECTIVE--The current study examined event-level characteristics (e.g., contextual factors, risk behaviors) during the most recent episode of Molly use among a sample of college students who reported previously using Molly. PARTICIPANTS--Participants (N = 151; 66.7% female) were drinkers aged 18 to 25. Data were collected from October to November 2014, February to April 2015, and September to November 2015. METHOD--Participants completed measures regarding typical Molly use and items related to context and behaviors during their most recent episode of Molly use. RESULTS--Findings revealed that our sample most commonly reported using Molly earlier in the evening while hanging out with friends or at a party. Additionally, sexual and other drug use behaviors commonly occurred when using Molly. CONCLUSIONS--Findings provide preliminary information in guiding future work exploring Molly use and potential substance-related issues associated with the context of when and how Molly is consumed

Axon degeneration induces glial responses through Draper-TRAF4-JNK signalling

Draper/Ced-1/MEGF-10 is an engulfment receptor that promotes clearance of cellular debris in C. elegans, Drosophila and mammals. Draper signals through an evolutionarily conserved Src family kinase cascade to drive cytoskeletal rearrangements and target engulfment through Rac1. Glia also alter gene expression patterns in response to axonal injury but pathways mediating these responses are poorly defined. We show Draper is cell autonomously required for glial activation of transcriptional reporters after axonal injury. We identify TNF receptor associated factor 4 (TRAF4) as a novel Draper binding partner that is required for reporter activation and phagocytosis of axonal debris. TRAF4 and misshapen (MSN) act downstream of Draper to activate c-Jun N-terminal kinase (JNK) signalling in glia, resulting in changes in transcriptional reporters that are dependent on Drosophila AP-1 (dAP-1) and STAT92E. Our data argue injury signals received by Draper at the membrane are important regulators of downstream transcriptional responses in reactive glia

Glial wingless/Wnt regulates glutamate receptor clustering and synaptic physiology at the Drosophila neuromuscular junction

Glial cells are emerging as important regulators of synapse formation, maturation, and plasticity through the release of secreted signaling molecules. Here we use chromatin immunoprecipitation along with Drosophila genomic tiling arrays to define potential targets of the glial transcription factor Reversed polarity (Repo). Unexpectedly, we identified wingless (wg), a secreted morphogen that regulates synaptic growth at the Drosophila larval neuromuscular junction (NMJ), as a potential Repo target gene. We demonstrate that Repo regulates wg expression in vivo and that local glial cells secrete Wg at the NMJ to regulate glutamate receptor clustering and synaptic function. This work identifies Wg as a novel in vivo glial-secreted factor that specifically modulates assembly of the postsynaptic signaling machinery at the Drosophila NMJ

Prevalence of Hypermobile Ehlers-Danlos Syndrome in Postural Orthostatic Tachycardia Syndrome

Despite well-established clinical associations between Hypermobile Ehlers-Danlos syndrome (hEDS) and postural orthostatic tachycardia syndrome (POTS), the precise prevalence is unknown. We therefore evaluated for hEDS in 91 POTS participants using the 2017 hEDS diagnostic checklist, which has three major criteria: 1) generalized joint hypermobility (Beighton score), 2) systemic features, family history, and 3) absence of exclusion criteria. Overall, 28 out of 91 POTS participants (31%) met clinical criteria for hEDS. An additional 24% of participants had generalized joint hypermobility without meeting hEDS criteria. Identifying the prevalence of hEDS in POTS is important for understanding possible mechanisms connecting these two syndromes

Molly Users Versus Non-Users in a Sample of College Alcohol Drinkers: Differences in Substance-Related Harms and Sensation Seeking

Background: Molly is one form of MDMA (3,4-methylenedioxymethamphetamine) that is touted to be more pure and potentially less harmful than other forms, such as ecstasy. Media reports and case studies suggest that this drug is popular among college students and is related to adverse health problems. The current study sought to address the knowledge gaps about Molly by examining whether users differ in substance use outcomes and sensation seeking than nonusers. Specifically, this study tested whether Molly users engaged in heavier use of other substances and experienced more substance-related harms in general than nonusers. Further, the current study investigated whether Molly users exhibited higher levels of sensation seeking than nonusers. Lastly, this study examined whether Molly user status would be associated with substance-related harms beyond the confounding influence of other substance use and trait sensation seeking. Methods: Participants were 710 (71.9% female) college alcohol drinkers who completed self-report surveys about substance use (i.e., Molly, alcohol, and other drug use), substance-related problems, and sensation seeking. Results: Results revealed that approximately 12% of the sample reported lifetime Molly use. Molly users compared with nonusers reported higher levels of other drug use, alcohol use, substance-related problems, and sensation seeking. Further, Molly users reported experiencing poorer substance use outcomes (e.g., blacking out, academic/occupational problems, and withdrawal symptoms) after accounting for sensation seeking and other substance use. Conclusions: These findings indicate that Molly users are higher in sensation seeking and that use is uniquely related to greater risk for substance-related harms. These preliminary findings demonstrate a need for correcting possible misperceptions regarding the purity of Molly and educating users on the potential for experiencing associated harms. Such information could be used to develop efficacious prevention programming for college students

WldS requires Nmnat1 enzymatic activity and N16–VCP interactions to suppress Wallerian degeneration

Slow Wallerian degeneration (WldS) encodes a chimeric Ube4b/nicotinamide mononucleotide adenylyl transferase 1 (Nmnat1) fusion protein that potently suppresses Wallerian degeneration, but the mechanistic action of WldS remains controversial. In this study, we characterize WldS-mediated axon protection in vivo using Drosophila melanogaster. We show that Nmnat1 can protect severed axons from autodestruction but at levels significantly lower than WldS, and enzyme-dead versions of Nmnat1 and WldS exhibit severely reduced axon-protective function. Interestingly, a 16–amino acid N-terminal domain of WldS (termed N16) accounts for the differences in axon-sparing activity between WldS and Nmnat1, and N16-dependent enhancement of Nmnat1-protective activity in WldS requires the N16-binding protein valosin-containing protein (VCP)/TER94. Thus, WldS-mediated suppression of Wallerian degeneration results from VCP–N16 interactions and Nmnat1 activity converging in vivo. Surprisingly, mouse Nmnat3, a mitochondrial Nmnat enzyme that localizes to the cytoplasm in Drosophila cells, protects severed axons at levels indistinguishable from WldS. Thus, nuclear Nmnat activity does not appear to be essential for WldS-like axon protection

The Protein Maker: an automated system for high-throughput parallel purification

The Protein Maker instrument addresses a critical bottleneck in structural genomics by allowing automated purification and buffer testing of multiple protein targets in parallel with a single instrument. Here, the use of this instrument to (i) purify multiple influenza-virus proteins in parallel for crystallization trials and (ii) identify optimal lysis-buffer conditions prior to large-scale protein purification is described

Biochemical warfare on the reef : the role of glutathione transferases in consumer tolerance of dietary prostaglandins

© 2010 The Authors. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in PLoS ONE 5 (2010): e8537, doi:10.1371/journal.pone.0008537.Despite the profound variation among marine consumers in tolerance for allelochemically-rich foods, few studies have examined the biochemical adaptations underlying diet choice. Here we examine the role of glutathione S-transferases (GSTs) in the detoxification of dietary allelochemicals in the digestive gland of the predatory gastropod Cyphoma gibbosum, a generalist consumer of gorgonian corals. Controlled laboratory feeding experiments were used to investigate the influence of gorgonian diet on Cyphoma GST activity and isoform expression. Gorgonian extracts and semi-purified fractions were also screened to identify inhibitors and possible substrates of Cyphoma GSTs. In addition, we investigated the inhibitory properties of prostaglandins (PGs) structurally similar to antipredatory PGs found in high concentrations in the Caribbean gorgonian Plexaura homomalla. Cyphoma GST subunit composition was invariant and activity was constitutively high regardless of gorgonian diet. Bioassay-guided fractionation of gorgonian extracts revealed that moderately hydrophobic fractions from all eight gorgonian species examined contained putative GST substrates/inhibitors. LC-MS and NMR spectral analysis of the most inhibitory fraction from P. homomalla subsequently identified prostaglandin A2 (PGA2) as the dominant component. A similar screening of commercially available prostaglandins in series A, E, and F revealed that those prostaglandins most abundant in gorgonian tissues (e.g., PGA2) were also the most potent inhibitors. In vivo estimates of PGA2 concentration in digestive gland tissues calculated from snail grazing rates revealed that Cyphoma GSTs would be saturated with respect to PGA2 and operating at or near physiological capacity. The high, constitutive activity of Cyphoma GSTs is likely necessitated by the ubiquitous presence of GST substrates and/or inhibitors in this consumer's gorgonian diet. This generalist's GSTs may operate as ‘all-purpose’ detoxification enzymes, capable of conjugating or sequestering a broad range of lipophilic gorgonian compounds, thereby allowing this predator to exploit a range of chemically-defended prey, resulting in a competitive dietary advantage for this species.Financial support for this work was provided by the Ocean Life Institute Tropical Research Initiative Grant (WHOI) to KEW and MEH; the Robert H. Cole Endowed Ocean Ventures Fund (WHOI) to KEW; the National Undersea Research Center - Program Development Proposal (CMRC-03PRMN0103A) to KEW; Walter A. and Hope Noyes Smith, and a National Science Foundation Graduate Research Fellowship to KEW