Scopus list of publications for January 22, 2023
Knockout of TSC2 in Nav1.8+ neurons predisposes to the onset of normal weight obesity
(2023) Molecular Metabolism, 68, art. no. 101664, .
Brazill, J.M.a , Shin, D.a , Magee, K.a , Majumdar, A.a , Shen, I.R.a , Cavalli, V.b c d , Scheller, E.L.a c e f
a Department of Medicine, Division of Bone and Mineral Diseases, Washington University, Saint Louis, MO, United States
b Department of Neuroscience, Washington University, Saint Louis, MO, United States
c Center of Regenerative Medicine, Washington University School of Medicine, Saint Louis, MO, United States
d Hope Center for Neurological Disorders, Washington University School of Medicine, Saint Louis, MO, United States
e Department of Cell Biology and Physiology, Washington University, Saint Louis, MO, United States
f Department of Biomedical Engineering, Washington University, Saint Louis, MO, United States
Abstract
Objective: Obesity and nutrient oversupply increase mammalian target of rapamycin (mTOR) signaling in multiple cell types and organs, contributing to the onset of insulin resistance and complications of metabolic disease. However, it remains unclear when and where mTOR activation mediates these effects, limiting options for therapeutic intervention. The objective of this study was to isolate the role of constitutive mTOR activation in Nav1.8-expressing peripheral neurons in the onset of diet-induced obesity, bone loss, and metabolic disease. Methods: In humans, loss of function mutations in tuberous sclerosis complex 2 (TSC2) lead to maximal constitutive activation of mTOR. To mirror this in mice, we bred Nav1.8-Cre with TSC2fl/fl animals to conditionally delete TSC2 in Nav1.8-expressing neurons. Male and female mice were studied from 4- to 34-weeks of age and a subset of animals were fed a high-fat diet (HFD) for 24-weeks. Assays of metabolism, body composition, bone morphology, and behavior were performed. Results: By lineage tracing, Nav1.8-Cre targeted peripheral sensory neurons, a subpopulation of postganglionic sympathetics, and several regions of the brain. Conditional knockout of TSC2 in Nav1.8-expressing neurons (Nav1.8-TSC2KO) selectively upregulated neuronal mTORC1 signaling. Male, but not female, Nav1.8-TSC2KO mice had a 4–10% decrease in body size at baseline. When challenged with HFD, both male and female Nav1.8-TSC2KO mice resisted diet-induced gains in body mass. However, this did not protect against HFD-induced metabolic dysfunction and bone loss. In addition, despite not gaining weight, Nav1.8-TSC2KO mice fed HFD still developed high body fat, a unique phenotype previously referred to as ‘normal weight obesity’. Nav1.8-TSC2KO mice also had signs of chronic itch, mild increases in anxiety-like behavior, and sex-specific alterations in HFD-induced fat distribution that led to enhanced visceral obesity in males and preferential deposition of subcutaneous fat in females. Conclusions: Knockout of TSC2 in Nav1.8+ neurons increases itch- and anxiety-like behaviors and substantially modifies fat storage and metabolic responses to HFD. Though this prevents HFD-induced weight gain, it masks depot-specific fat expansion and persistent detrimental effects on metabolic health and peripheral organs such as bone, mimicking the ‘normal weight obesity’ phenotype that is of growing concern. This supports a mechanism by which increased neuronal mTOR signaling can predispose to altered adipose tissue distribution, adipose tissue expansion, impaired peripheral metabolism, and detrimental changes to skeletal health with HFD – despite resistance to weight gain. © 2022 The Authors
Author Keywords
Anxiety; Bone; High fat diet; Itch; mTOR; Nav1.8; Neurometabolism; Normal weight obesity; Sensory nerve; Skinny fat
Funding details
National Institutes of HealthNIHP30-AR074992, R56-AR081251, T32-AR060719
Musculoskeletal Research Center, Washington University in St. LouisMRCP30-DK020579
Department of Medicine, Georgetown University
Document Type: Article
Publication Stage: Final
Source: Scopus
ApoE isoform- and microbiota-dependent progression of neurodegeneration in a mouse model of tauopathy
(2023) Science (New York, N.Y.), 379 (6628), p. eadd1236.
Seo, D.-O.a , O’Donnell, D.b , Jain, N.a , Ulrich, J.D.a , Herz, J.c d , Li, Y.e , Lemieux, M.c d , Cheng, J.b , Hu, H.a , Serrano, J.R.a , Bao, X.a , Franke, E.a , Karlsson, M.b , Meier, M.b , Deng, S.b , Desai, C.b , Dodiya, H.f , Lelwala-Guruge, J.b , Handley, S.A.d , Kipnis, J.c d , Sisodia, S.S.f , Gordon, J.I.b d , Holtzman, D.M.a g
a Department of Neurology, Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, United States
b Edison Family Center for Genome Sciences and Systems Biology and the Center for Gut Microbiome and Nutrition Research, Washington University School of Medicine, St. Louis, MO, United States
c Center for Brain Immunology and Glia (BIG), Washington University School of Medicine, St. Louis, MO, United States
d Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, United States
e Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
f Department of Neurobiology, University of Chicago, Chicago, IL, United States
g Knight Alzheimer Disease Research Center, Washington University School of Medicine, St. Louis, MO, United States
Abstract
Tau-mediated neurodegeneration is a hallmark of Alzheimer’s disease. Primary tauopathies are characterized by pathological tau accumulation and neuronal and synaptic loss. Apolipoprotein E (ApoE)-mediated neuroinflammation is involved in the progression of tau-mediated neurodegeneration, and emerging evidence suggests that the gut microbiota regulates neuroinflammation in an APOE genotype-dependent manner. However, evidence of a causal link between the microbiota and tau-mediated neurodegeneration is lacking. In this study, we characterized a genetically engineered mouse model of tauopathy expressing human ApoE isoforms reared under germ-free conditions or after perturbation of their gut microbiota with antibiotics. Both of these manipulations reduced gliosis, tau pathology, and neurodegeneration in a sex- and ApoE isoform-dependent manner. The findings reveal mechanistic and translationally relevant interrelationships between the microbiota, neuroinflammation, and tau-mediated neurodegeneration.
Document Type: Article
Publication Stage: Final
Source: Scopus
A single-cell massively parallel reporter assay detects cell-type-specific gene regulation
(2023) Nature Genetics, .
Zhao, S.a b d , Hong, C.K.Y.a b , Myers, C.A.c , Granas, D.M.a b , White, M.A.a b , Corbo, J.C.c , Cohen, B.A.a b
a Edison Family Center for Systems Biology and Genome Sciences, Washington University School of Medicine, St. Louis, MO, United States
b Department of Genetics, Washington University School of Medicine, St. Louis, MO, United States
c Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, United States
d Ginkgo Bioworks, Boston, MA, United States
Abstract
Massively parallel reporter gene assays are key tools in regulatory genomics but cannot be used to identify cell-type-specific regulatory elements without performing assays serially across different cell types. To address this problem, we developed a single-cell massively parallel reporter assay (scMPRA) to measure the activity of libraries of cis-regulatory sequences (CRSs) across multiple cell types simultaneously. We assayed a library of core promoters in a mixture of HEK293 and K562 cells and showed that scMPRA is a reproducible, highly parallel, single-cell reporter gene assay that detects cell-type-specific cis-regulatory activity. We then measured a library of promoter variants across multiple cell types in live mouse retinas and showed that subtle genetic variants can produce cell-type-specific effects on cis-regulatory activity. We anticipate that scMPRA will be widely applicable for studying the role of CRSs across diverse cell types. © 2023, The Author(s), under exclusive licence to Springer Nature America, Inc.
Funding details
National Institutes of HealthNIHR01 EY030075, R01 GM092910, R01 GM140711
Document Type: Article
Publication Stage: Article in Press
Source: Scopus
Monosynaptic restriction of the anterograde herpes simplex virus strain H129 for neural circuit tracing
(2023) Journal of Comparative Neurology, .
Fischer, K.B.a , Collins, H.K.a , Pang, Y.a , Roy, D.S.b , Zhang, Y.c , Feng, G.b c , Li, S.-J.d , Kepecs, A.e , Callaway, E.M.a
a Systems Neurobiology Laboratories, Salk Institute for Biological Studies, La JollaCA, United States
b Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, United States
c Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research at MIT, Cambridge, MA, United States
d Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, United States
e Departments of Neuroscience and Psychiatry, Washington University School of Medicine, St. Louis, MO, United States
Abstract
Identification of synaptic partners is a fundamental task for systems neuroscience. To date, few reliable techniques exist for whole brain labeling of downstream synaptic partners in a cell-type-dependent and monosynaptic manner. Herein, we describe a novel monosynaptic anterograde tracing system based on the deletion of the gene UL6 from the genome of a cre-dependent version of the anterograde Herpes Simplex Virus 1 strain H129. Given that this knockout blocks viral genome packaging and thus viral spread, we reasoned that co-infection of a HSV H129 ΔUL6 virus with a recombinant adeno-associated virus expressing UL6 in a cre-dependent manner would result in monosynaptic spread from target cre-expressing neuronal populations. Application of this system to five nonreciprocal neural circuits resulted in labeling of neurons in expected projection areas. While some caveats may preclude certain applications, this system provides a reliable method to label postsynaptic partners in a brain-wide fashion. © 2023 Wiley Periodicals LLC.
Funding details
National Science FoundationNSFIOS‐1707261
National Institutes of HealthNIHEY022577, MH063912, U01MH114819
National Institute of Neurological Disorders and StrokeNINDSR01NS075531
Massachusetts Institute of TechnologyMIT
Broad Institute
Document Type: Article
Publication Stage: Article in Press
Source: Scopus
Semiautomated analysis of an optical ATP indicator in neurons
(2022) Neurophotonics, 9 (4), art. no. 041410, .
Dehkharghanian, T.a , Hashemiaghdam, A.b , Ashrafi, G.b
a McMaster University, Faculty of Health Sciences, Hamilton, ON, Canada
b Washington University School of Medicine in St. Louis, Needleman Center for Neurometabolism and Axonal Therapeutics, Department of Cell Biology and Physiology, Department of Genetics, St. Louis, MO, United States
Abstract
Significance: The firefly enzyme luciferase has been used in a wide range of biological assays, including bioluminescence imaging of adenosine triphosphate (ATP). The biosensor Syn-ATP utilizes subcellular targeting of luciferase to nerve terminals for optical measurement of ATP in this compartment. Manual analysis of Syn-ATP signals is challenging due to signal heterogeneity and cellular motion in long imaging sessions. Here, we have leveraged machine learning tools to develop a method for analysis of bioluminescence images. Aim: Our goal was to create a semiautomated pipeline for analysis of bioluminescence imaging to improve measurements of ATP content in nerve terminals. Approach: We developed an image analysis pipeline that applies machine learning toolkits to distinguish neurons from background signals and excludes neural cell bodies, while also incorporating user input. Results: Side-by-side comparison of manual and semiautomated image analysis demonstrated that the latter improves precision and accuracy of ATP measurements. Conclusions: Our method streamlines data analysis and reduces user-introduced bias, thus enhancing the reproducibility and reliability of quantitative ATP imaging in nerve terminals. © 2022 The Authors. Published by SPIE under a Creative Commons Attribution 4.0 International License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.
Author Keywords
ATP; bioluminescence; image analysis; machine learning; nerve terminals
Document Type: Article
Publication Stage: Final
Source: Scopus
Cortex-wide response mode of VIP-expressing inhibitory neurons by reward and punishment
(2022) eLife, 11, art. no. e78815, .
Szadai, Z.a b c d , Pi, H.-J.e f , Chevy, Q.e g , Ócsai, K.b d h i , Albeanu, D.F.e , Chiovini, B.a , Szalay, G.a , Katona, G.b , Kepecs, A.e g , Rózsa, B.a d
a Laboratory of 3D functional network and dendritic imaging, Institute of Experimental Medicine, Budapest, Hungary
b MTA-PPKE ITK-NAP B – 2p Measurement Technology Group, The Faculty of Information Technology, Pázmány Péter Catholic University, Budapest, Hungary
c János Szentágothai Doctoral School of Neurosciences, Semmelweis University, Budapest, Hungary
d BrainVisionCenter, Budapest, Hungary
e Cold Spring Harbor Laboratory, Cold Spring Harbor, United States
f Volen Center for Complex Systems, Biology Department, Brandeis University, Waltham, United States
g Departments of Neuroscience and Psychiatry, Washington University School of Medicine, St. Louis, United States
h Computational Systems Neuroscience Lab, Wigner Research Centre for Physics, Budapest, Hungary
i Department of Mathematical Geometry, Institute of Mathematics, Budapest University of Technology and Economics, Budapest, Hungary
Abstract
Neocortex is classically divided into distinct areas, each specializing in different function, but all could benefit from reinforcement feedback to inform and update local processing. Yet it remains elusive how global signals like reward and punishment are represented in local cortical computations. Previously, we identified a cortical neuron type, vasoactive intestinal polypeptide (VIP)-expressing interneurons, in auditory cortex that is recruited by behavioral reinforcers and mediates disinhibitory control by inhibiting other inhibitory neurons. As the same disinhibitory cortical circuit is present virtually throughout cortex, we wondered whether VIP neurons are likewise recruited by reinforcers throughout cortex. We monitored VIP neural activity in dozens of cortical regions using three-dimensional random access two-photon microscopy and fiber photometry while mice learned an auditory discrimination task. We found that reward and punishment during initial learning produce rapid, cortex-wide activation of most VIP interneurons. This global recruitment mode showed variations in temporal dynamics in individual neurons and across areas. Neither the weak sensory tuning of VIP interneurons in visual cortex nor their arousal state modulation was fully predictive of reinforcer responses. We suggest that the global response mode of cortical VIP interneurons supports a cell-type-specific circuit mechanism by which organism-level information about reinforcers regulates local circuit processing and plasticity. © Szadai, Pi, Chevy et al.
Funding details
VKSZ_14-1-2015-0155 KFI_16-1-2016-0177 NVKP_16-1-2016-0043
National Institutes of HealthNIHR01MH110391, R01NS075531, R01NS088661
National Alliance for Research on Schizophrenia and DepressionNARSAD
Horizon 2020 Framework ProgrammeH2020682426, 712821-NEURAM, VISGEN_734862
European Research CouncilERC
Magyar Tudományos AkadémiaMTA
Nemzeti Kutatási, Fejlesztési és Innovaciós AlapNKFIAKFI_16-1-2016-0177, VKSZ_14-1-2015-0155
1.2.1-NKP-2017–00002, GINOP_2.1.1-15-2016-00979, KFI-2018–00097, KTIA_NAP_12-2-2015-0006, NKP-2017–00001, VKE-2018–00032
Document Type: Article
Publication Stage: Final
Source: Scopus