VCP suppresses proteopathic seeding in neurons(2022) Molecular Neurodegeneration, 17 (1), art. no. 30
Zhu, J.a , Pittman, S.a , Dhavale, D.a , French, R.b , Patterson, J.N.a , Kaleelurrrahuman, M.S.a , Sun, Y.c , Vaquer-Alicea, J.d , Maggiore, G.d , Clemen, C.S.e f , Buscher, W.J.g , Bieschke, J.c , Kotzbauer, P.a , Ayala, Y.b , Diamond, M.I.d , Davis, A.A.a , Weihl, C.a
AbstractBackground: Neuronal uptake and subsequent spread of proteopathic seeds, such as αS (alpha-synuclein), Tau, and TDP-43, contribute to neurodegeneration. The cellular machinery participating in this process is poorly understood. One proteinopathy called multisystem proteinopathy (MSP) is associated with dominant mutations in Valosin Containing Protein (VCP). MSP patients have muscle and neuronal degeneration characterized by aggregate pathology that can include αS, Tau and TDP-43. Methods: We performed a fluorescent cell sorting based genome-wide CRISPR-Cas9 screen in αS biosensors. αS and TDP-43 seeding activity under varied conditions was assessed using FRET/Flow biosensor cells or immunofluorescence for phosphorylated αS or TDP-43 in primary cultured neurons. We analyzed in vivo seeding activity by immunostaining for phosphorylated αS following intrastriatal injection of αS seeds in control or VCP disease mutation carrying mice. Results: One hundred fifty-four genes were identified as suppressors of αS seeding. One suppressor, VCP when chemically or genetically inhibited increased αS seeding in cells and neurons. This was not due to an increase in αS uptake or αS protein levels. MSP-VCP mutation expression increased αS seeding in cells and neurons. Intrastriatal injection of αS preformed fibrils (PFF) into VCP-MSP mutation carrying mice increased phospho αS expression as compared to control mice. Cells stably expressing fluorescently tagged TDP-43 C-terminal fragment FRET pairs (TDP-43 biosensors) generate FRET when seeded with TDP-43 PFF but not monomeric TDP-43. VCP inhibition or MSP-VCP mutant expression increases TDP-43 seeding in TDP-43 biosensors. Similarly, treatment of neurons with TDP-43 PFFs generates high molecular weight insoluble phosphorylated TDP-43 after 5 days. This TDP-43 seed dependent increase in phosphorlyated TDP-43 is further augmented in MSP-VCP mutant expressing neurons. Conclusion: Using an unbiased screen, we identified the multifunctional AAA ATPase VCP as a suppressor of αS and TDP-43 aggregate seeding in cells and neurons. VCP facilitates the clearance of damaged lysosomes via lysophagy. We propose that VCP’s surveillance of permeabilized endosomes may protect against the proteopathic spread of pathogenic protein aggregates. The spread of distinct aggregate species may dictate the pleiotropic phenotypes and pathologies in VCP associated MSP. © 2022, The Author(s).
Effects of Framingham 10-Year Cardiovascular Risk Score and Viral Load on Brain Integrity in Persons With HIV(2022) Journal of acquired immune deficiency syndromes (1999), 90 (1), pp. 79-87.
Glans, M.a , Cooley, S.A.a , Vaida, F.b , Boerwinkle, A.a , Tomov, D.a , Petersen, K.J.a , Rosenow, A.a , Paul, R.H.c , Ances, B.M.a d e
AbstractBACKGROUND: Combination antiretroviral therapy (cART) has allowed for viral load (VL) suppression and increased life expectancy for persons with HIV (PWH). Altered brain integrity, measured by neuropsychological (NP) performance and neuroimaging, is still prevalent among virally suppressed PWH. Age-related conditions such as cardiovascular disease may also affect brain integrity. This study investigated the effects of cardiovascular risk, VL, and HIV serostatus on cerebral blood flow (CBF), brain volumetrics, and cognitive function in PWH and persons without HIV (PWoH). METHODS: Ten-year cardiovascular risk, using the Framingham Heart Study criteria, was calculated in PWH (n = 164) on cART with undetectable (≤20 copies/mL; n = 134) or detectable (>20 copies/mL; n = 30) VL and PWoH (n = 66). The effects of cardiovascular risk on brain integrity (CBF, volume, and cognition) were compared for PWH (undetectable and detectable VL) and PWoH. RESULTS: PWH had smaller brain volumes and worse NP scores than PWoH. PWH with detectable and undetectable VL had similar brain integrity measures. Higher cardiovascular risk was associated with smaller volumes and lower CBF in multiple brain regions for PWH and PWoH. Significant interactions between HIV serostatus and cardiovascular risk on brain volumes were observed in frontal, orbitofrontal, and motor regions. Cardiovascular risk was not associated with cognition for PWH or PWoH. CONCLUSIONS: Neuroimaging, but not cognitive measures, was associated with elevated cardiovascular risk. HIV serostatus was associated with diminished brain volumes and worse cognition while CBF remained unchanged, reflecting potential protective effects of cART. Neuroimaging measures of structure (volume) and function (CBF) may identify contributions of comorbidities, but future longitudinal studies are needed. Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.
Quantifying stability of parameter estimates forin vivonearly incompressible transversely-isotropic brain MR elastography(2022) Biomedical physics & engineering express, 8 (3)
Jyoti, D.a , McGarry, M.a , Van Houten, E.b , Sowinski, D.a , Bayly, P.V.c , Johnson, C.L.d , Paulsen, K.a e
AbstractEasily computable quality metrics for measured medical data at point-of-care are important for imaging technologies involving offline reconstruction. Accordingly, we developed a new data quality metric forin vivotransversely-isotropic (TI) magnetic resonance elastography (MRE) based on a generalization of the widely accepted octahedral shear-strain calculation. The metric uses MRE displacement data and an estimate of the TI property field to yield a ‘stability map’ which predicts regions of low versus high accuracy in the resulting material property reconstructions. We can also calculate an average TI parameter stability (TIPS) score over all voxels in a region of interest for a given measurement to indicate how reliable the recovered mechanical property estimate for the region is expected to be. The calculation is rapid and places little demand on computing resources compared to the computationally intensive material property reconstruction from non-linear inversion (TI-NLI) of displacement fields, making it ideal for point-of-care evaluation of data quality. We test the predictions of the stability map for both simulated phantoms andin vivohuman brain data. We used a range of different displacement datasets from vibrations applied in the anterior-posterior (AP), left-right (LR) and combined AP + LR directions. The TIPS and variability maps (noise sensitivity or variation from the mean of repeated MRE scans) were consistently anti-correlated. Notably, Spearman correlation coefficients ∣R∣>0.6 were found between variability and TIPS score for individual white matter tracts within vivodata. These observations demonstrate the reliability and promise of this data quality metric to screen data rapidly in realistic clinical MRE applications. © 2022 IOP Publishing Ltd.
Short-Duration, Pulsatile, Electrical Stimulation Therapy Accelerates Axon Regeneration and Recovery following Tibial Nerve Injury and Repair in Rats(2022) Plastic and Reconstructive Surgery, 149 (4), pp. 681E-690E
Roh, J.a b , Schellhardt, L.a b , Keane, G.C.a b , Hunter, D.A.a b , Moore, A.M.a b , Snyder-Warwick, A.K.a b , MacKinnon, S.E.a b , Wood, M.D.a b
AbstractBackground: Repair of nerve injuries can fail to achieve adequate functional recovery. Electrical stimulation applied at the time of nerve repair can accelerate axon regeneration, which may improve the likelihood of recovery. However, widespread use of electrical stimulation may be limited by treatment protocols that increase operative time and complexity. This study evaluated whether a short-duration electrical stimulation protocol (10 minutes) was efficacious to enhance regeneration following nerve repair using rat models. Methods: Lewis and Thy1-green fluorescent protein rats were randomized to three groups: 0 minutes of electrical stimulation (no electrical stimulation; control), 10 minutes of electrical stimulation, and 60 minutes of electrical stimulation. All groups underwent tibial nerve transection and repair. In the intervention groups, electrical stimulation was delivered after nerve repair. Outcomes were assessed using immunohistochemistry, histology, and serial walking track analysis. Results: Two weeks after nerve repair, Thy1-green fluorescent protein rats demonstrated increased green fluorescent protein-positive axon outgrowth from the repair site with electrical stimulation compared to no electrical stimulation. Serial measurement of walking tracks after nerve repair revealed recovery was achieved more rapidly in both electrical stimulation groups as compared to no electrical stimulation. Histologic analysis of nerve distal to the repair at 8 weeks revealed robust axon regeneration in all groups. Conclusions: As little as 10 minutes of intraoperative electrical stimulation therapy increased early axon regeneration and facilitated functional recovery following nerve transection with repair. Also, as early axon outgrowth increased following electrical stimulation with nerve repair, these findings suggest electrical stimulation facilitated recovery because of earlier axon growth across the suture-repaired site into the distal nerve to reach end-organ targets. Clinical Relevance Statement: Brief (10-minute) electrical stimulation therapy can provide similar benefits to the 60-minute protocol in an acute sciatic nerve transection/repair rat model and merit further studies, as they represent a translational advantage. © 2022 Lippincott Williams and Wilkins. All rights reserved.
Soto, F.a , Shen, N.b , Kerschensteiner, D.c d e fAMIGO1 Promotes Axon Growth and Territory Matching in the Retina(2022) The Journal of neuroscience : the official journal of the Society for Neuroscience, 42 (13), pp. 2678-2689
AbstractDendrite and axon arbor sizes are critical to neuronal function and vary widely between different neuron types. The relative dendrite and axon sizes of synaptic partners control signal convergence and divergence in neural circuits. The developmental mechanisms that determine cell-type-specific dendrite and axon size and match synaptic partners’ arbor territories remain obscure. Here, we discover that retinal horizontal cells express the leucine-rich repeat domain cell adhesion molecule AMIGO1. Horizontal cells provide pathway-specific feedback to photoreceptors-horizontal cell axons to rods and horizontal cell dendrites to cones. AMIGO1 selectively expands the size of horizontal cell axons. When Amigo1 is deleted in all or individual horizontal cells of either sex, their axon arbors shrink. By contrast, horizontal cell dendrites and synapse formation of horizontal cell axons and dendrites are unaffected by AMIGO1 removal. The dendrites of rod bipolar cells, which do not express AMIGO1, shrink in parallel with horizontal cell axons in Amigo1 knockout (Amigo1 KO) mice. This territory matching maintains the function of the rod bipolar pathway, preserving bipolar cell responses and retinal output signals in Amigo1 KO mice. We previously identified AMIGO2 as a scaling factor that constrains retinal neurite arbors. Our current results identify AMIGO1 as a scaling factor that expands retinal neurite arbors and reveal territory matching as a novel homeostatic mechanism. Territory matching interacts with other homeostatic mechanisms to stabilize the development of the rod bipolar pathway, which mediates vision near the threshold.SIGNIFICANCE STATEMENT Neurons send and receive signals through branched axonal and dendritic arbors. The size of these arbors is critical to the function of a neuron. Axons and dendrites grow during development and are stable at maturity. The mechanisms that determine axon and dendrite size are not well understood. Here, we identify a cell surface protein, AMIGO1, that selectively promotes axon growth of horizontal cells, a retinal interneuron. Removal of AMIGO1 reduces the size of horizontal cell axons without affecting the size of their dendrites or the ability of both arbors to form connections. The changes in horizontal cell axons are matched by changes in synaptic partner dendrites to stabilize retinal function. This identifies territory matching as a novel homeostatic plasticity mechanism. Copyright © 2022 the authors.
The Enantiomer of Allopregnanolone Prevents Pressure-Mediated Retinal Degeneration Via Autophagy(2022) Frontiers in Pharmacology, 13, art. no. 855779,
Ishikawa, M.a b , Nakazawa, T.a b c d , Kunikata, H.b c , Sato, K.a d , Yoshitomi, T.e f , Krishnan, K.g , Covey, D.F.g h i j , Zorumski, C.F.i j k , Izumi, Y.i j k
AbstractIn an ex vivo rat ocular hypertension (OHT) model, the neurosteroid allopregnanolone (AlloP) exerts neuroprotective effects via enhancement of both GABAA receptors and autophagy. We now examine whether its enantiomer (ent-AlloP), which is largely inactive at GABA receptors, offers similar neuroprotection in ex vivo and in vivo rat OHT models. Ex vivo rat retinal preparations were incubated in a hyperbaric condition (10 and 75 mmHg) for 24 h. An in vivo ocular hypertension (OHT) model was induced by intracameral injection of polystyrene microbeads. We examined pharmacological effects of AlloP, ent-AlloP, picrotoxin (a GABAA receptor antagonist), and 3-MA (an autophagy inhibitor) histologically and biochemically. We found that both AlloP and ent-AlloP have marked neuroprotective effects in the retina, but effects of the unnatural enantiomer are independent of GABAA receptors. Electron microscopic analyses show that pressure elevation significantly increased autophagosomes (APs) in the nerve fiber layer and addition of AlloP also increased APs and degenerative autophagic vacuoles (AVds). ent-AlloP markedly increased APs and AVds compared to AlloP. Examination of LC3B-II and SQSTM1 protein levels using immunoblotting revealed that AlloP increased LC3B-II, and ent-AlloP further enhanced LC3B-II and suppressed SQSTM1, indicating that autophagy is a major mechanism underlying neuroprotection by ent-AlloP. In an rat in vivo OHT model, single intravitreal ent-AlloP injection prevented apoptotic cell death of retinal ganglion cells similar to AlloP. However, even in this model, ent-AlloP was more effective in activating autophagy than AlloP. We conclude that ent-AlloP may be a prototype of potential therapeutic for treatment of glaucoma as an autophagy enhancer without affecting GABA receptors. Copyright © 2022 Ishikawa, Nakazawa, Kunikata, Sato, Yoshitomi, Krishnan, Covey, Zorumski and Izumi.
Importance of the intersection of age and sex to understand variation in incidence and survival for primary malignant gliomas(2022) Neuro-oncology, 24 (2), pp. 302-310
Wang, G.-M.a b , Cioffi, G.a b c d , Patil, N.d e , Waite, K.A.a b c d , Lanese, R.a b , Ostrom, Q.T.d f , Kruchko, C.d , Berens, M.E.g , Connor, J.R.h , Lathia, J.D.i j , Rubin, J.B.k , Barnholtz-Sloan, J.S.a b c d j l m
AbstractBACKGROUND: Gliomas are the most common type of malignant brain and other CNS tumors, accounting for 80.8% of malignant primary brain and CNS tumors. They cause significant morbidity and mortality. This study investigates the intersection between age and sex to better understand variation of incidence and survival for glioma in the United States. METHODS: Incidence data from 2000 to 2017 were obtained from CBTRUS, which obtains data from the NPCR and SEER, and survival data from the CDC’s NPCR. Age-adjusted incidence rate ratios (IRR) per 100 000 were generated to compare male-to-female incidence by age group. Cox proportional hazard models were performed by age group, generating hazard ratios to assess male-to-female survival differences. RESULTS: Overall, glioma incidence was higher in males. Male-to-female incidence was lowest in ages 0-9 years (IRR: 1.04, 95% CI: 1.01-1.07, P = .003), increasing with age, peaking at 50-59 years (IRR: 1.56, 95% CI: 1.53-1.59, P < .001). Females had worse survival for ages 0-9 (HR: 0.93, 95% CI: 0.87-0.99), though male survival was worse for all other age groups, with the difference highest in those 20-29 years (HR: 1.36, 95% CI: 1.28-1.44). Incidence and survival differences by age and sex also varied by histological subtype of glioma. CONCLUSIONS: To better understand the variation in glioma incidence and survival, investigating the intersection of age and sex is key. The current work shows that the combined impact of these variables is dependent on glioma subtype. These results contribute to the growing understanding of sex and age differences that impact cancer incidence and survival. © The Author(s) 2021. Published by Oxford University Press on behalf of the Society for Neuro-Oncology.