Vps54 Regulates Lifespan and Locomotor Behavior in Adult Drosophila Melanogaster

Vps54 is an integral subunit of the Golgi-associated retrograde protein (GARP) complex, which is involved in tethering endosome-derived vesicles to the trans-Golgi network (TGN). A destabilizing missense mutation in Vps54 causes the age-progressive motor neuron (MN) degeneration, muscle weakness, and muscle atrophy observed in the wobbler mouse, an established animal model for human MN disease. It is currently unclear how the disruption of Vps54, and thereby the GARP complex, leads to MN and muscle phenotypes. To develop a new tool to address this question, we have created an analogous model in Drosophila by generating novel loss-of-function alleles of the fly Vps54 ortholog (scattered/scat). We find that null scat mutant adults are viable but have a significantly shortened lifespan. Like phenotypes observed in the wobbler mouse, we show that scat mutant adults are male sterile and have significantly reduced body size and muscle area. Moreover, we demonstrate that scat mutant adults have significant age-progressive defects in locomotor function. Interestingly, we see sexually dimorphic effects, with scat mutant adult females exhibiting significantly stronger phenotypes. Finally, we show that scat interacts genetically with rab11 in MNs to control age-progressive muscle atrophy in adults. Together, these data suggest that scat mutant flies share mutant phenotypes with the wobbler mouse and may serve as a new genetic model system to study the cellular and molecular mechanisms underlying MN disease

FXS-Causing Point Mutations in FMRP Disrupt Neuronal Granule Formation and Function

Fragile X Syndrome (FXS) is a neurodevelopmental disorder caused by the disruption of Fragile X Mental Retardation Protein (FMRP) function in neurons, affecting nearly 1 in 7,500 individuals. Although FXS typically occurs from a complete loss of FMRP expression due to a CGG trinucleotide expansion within the 5’UTR of the FMR1 gene, single nucleotide polymorphisms (SNPs) within the KH domains of FMRP have been shown to severely disrupt FMRP function. FMRP is an RNA-binding translation repressor that interacts with ~4% of the neuronal transcriptome. Many target mRNAs encode for proteins important for regulating synaptic processes and modulate synaptic plasticity. It is likely that FMRP differentially regulates this large subset of mRNAs via its association with specific membraneless organelles (MLOs), or granules, that are each involved in regulating different processes of the transcript lifecycle. How FMRP forms and interacts with different MLOs however, is largely unknown. Here we show that multivalent interactions via the two canonical KH domains, KH1 and KH2, and the C-terminal intrinsically disordered region (IDR) function cooperatively to promote FMRP granule formation in Drosophila S2 cells. Two mutations within the KH domains of FMRP have been linked to severe forms of FXS. We were interested in determining whether these mutations disrupted the formation or function of FMRP-containing MLOs. Here we studied these missense point mutations, by making the orthologous mutations in the fly KH1 (Gly269Glu) and KH2 (Ile307Asn) domains. Within FRAP experiments of fly S2 cells we found that each of the KH point mutants destabilized the dynamic mobile fraction of FMRP granules, while having no impact on immobile fractions. The KH1 mutant in particular has an important function in granule formation and FMRP association with other MLOs involved in posttranscriptional regulation including stress granules and RNA Processing-bodies. Additionally, we found that the KH1 mutation is defective in FMRP-mediated translation, while the KH2 mutant has no effect. We also studied the impact of these mutations in Drosophila primary motor neurons (MNs) where FMRP associates with neuronal RNA transport granules (NGs). Within NGs FMRP is thought to translationally repress transcripts during their active transport from the soma out to the synapse. Interestingly, we found that the KH1 mutant severely disrupted the nucleation of FMRP-positive NGs. The KH2 mutant on the other hand destabilized NGs, impacting NG transport out in neurites. Interestingly, we found that these mutations had no impact on camkii transport, a well characterized FMRP target, suggesting that FMRP-NG association and RNA transport may not be functionally linked processes

Global urban environmental change drives adaptation in white clover

Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural clines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Presynaptic CamKII Regulates Activity-dependent Axon Terminal Growth

Spaced synaptic depolarization induces rapid axon terminal growth and the formation of new synaptic boutons at the Drosophila larval neuromuscular junction (NMJ). Here, we identify a novel presynaptic function for the Calcium/Calmodulin-dependent Kinase II (CamKII) protein in the control of activity-dependent synaptic growth. Consistent with this function, we find that both total and phosphorylated CamKII (p-CamKII) are enriched in axon terminals. Interestingly, p-CamKII appears to be enriched at the presynaptic axon terminal membrane. Moreover, levels of total CamKII protein within presynaptic boutons globally increase within one hour following stimulation. These effects correlate with the activity-dependent formation of new presynaptic boutons. The increase in presynaptic CamKII levels is inhibited by treatment with cyclohexamide suggesting a protein-synthesis dependent mechanism. We have previously found that acute spaced stimulation rapidly downregulates levels of neuronal microRNAs (miRNAs) that are required for the control of activity-dependent axon terminal growth at this synapse. The rapid activity-dependent accumulation of CamKII protein within axon terminals is inhibited by overexpression of activity-regulated miR-289 in motor neurons. Experiments in vitro using a CamKII translational reporter show that miR-289 can directly repress the translation of CamKII via a sequence motif found within the CamKII 3′ untranslated region (UTR). Collectively, our studies support the idea that presynaptic CamKII acts downstream of synaptic stimulation and the miRNA pathway to control rapid activity-dependent changes in synapse structure

Intravenous Tissue Plasminogen Activator Administration in Community Hospitals Facilitated by Telestroke Service

Abstract BACKGROUND: Stroke is a leading cause of death and disability in the United States. Despite the proven benefits of intravenous tissue plasminogen activator (IV-tPA), only a small percentage of patients who have had a stroke (3.4%–5.2%) receive this US Food and Drug Administration-approved therapy. OBJECTIVE: To prospectively assess the impact of a telestroke network on the rate of IV-tPA administration in patients with acute ischemic stroke in community hospitals. METHODS: Thomas Jefferson University Hospital has developed a telestroke system providing acute stroke care in 28 community hospitals within the region (Pennsylvania, New Jersey, and Delaware). Telemedicine consultations are delivered through Remote Presence robotic technology. RESULTS: A total of 1643 telemedicine stroke consultations were provided between January 2011 and June 2012. The mean interval from consultation request to telemedicine response was 12.0 minutes. The overall rate of IV-tPA use was 14% among all stroke consultations. A total of 237 patients (14.4%) were determined to be eligible for intravenous thrombolysis. Of those, 97% received IV-tPA. Most hospitals (82%) within the telemedicine program reported an increase in IV-tPA use (mean increase, 55%). The proportion of patients transferred to a primary stroke center after teleconsultation decreased from 44% in the first 2 quarters of 2011 to 19% in the first 2 quarters of 2012 (P < .001). CONCLUSION: Implementing a telestroke system facilitates high rates of intravenous thrombolysis in patients who have had a stroke in community hospitals within a relatively short time frame. These results are higher than the national average rate (3.4%–5.2%) and support the implementation of telestroke networks for wider access to stroke expertise in underserved regions

Global urban environmental change drives adaptation in white clover

Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural clines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale

Global urban environmental change drives adaptation in white clover

Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural clines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale