Neurology Commons^™

Blue-Shifted Ancyromonad Channelrhodopsins For Multiplex Optogenetics, Elena G Govorunova, Oleg A Sineshchekov, Hai Li, Yueyang Gou, Hongmei Chen, Shuyuan Yang, Yumei Wang, Stephen Mitchell, Alyssa Palmateer, Leonid S Brown, François St-Pierre, Mingshan Xue, John L Spudich

Duncan NRI Faculty and Staff Publications

Light-gated ion channels from protists (channelrhodopsins or ChRs) are optogenetic tools widely used for controlling neurons and cardiomyocytes. Multiplex optogenetic applications require spectrally separated molecules, which are difficult to engineer without disrupting channel function. Scanning numerous sequence databases, we identified three naturally blue-shifted ChRs from ancyromonads. They form a separate branch on the phylogenetic tree and contain residue motifs characteristic of anion ChRs (ACRs). However, only two conduct chloride, whereas the closely related Nutomonas longa homolog generates inward cation currents in mammalian cells under physiological conditions, significantly exceeding those by previously known tools with similar spectral maxima (peak absorption at …

Developmental Transformations Of Purkinje Cells Tracked By Dna Electrokinetic Mobility, Cheryl Brandenburg, Garrett W Crutcher, Andrea J Romanowski, Sarah G Donofrio, Lita R Duraine, Richard N A Owusu-Mensah, Benjamin H Cooper, Izumi Sugihara, Gene J Blatt, Roy V Sillitoe, Alexandros Poulopoulos

Duncan NRI Faculty and Staff Publications

Brain development begins with neurogenesis in progenitor zones and ends with expansive, intricately-patterned cellular diversity in the adult brain. We took advantage of bioelectric interactions between DNA and embryonic tissue to perform "stereo-tracking," a developmental targeting strategy that differentially labels cells at different depths within progenitor zones. This 3D labeling was achieved by delivery of plasmids with distinct electrokinetic mobilities in utero. We applied stereo-tracking with light sheet imaging in the cerebellum and identified that Purkinje cells follow embryonically committed developmental trajectories, linking distinct progenitor zone subfields to the mature topography of the cerebellar cortex. We additionally identified an unexpected …

Computationally Resolved Neuroprogenitor Cell Biomarkers Associate With Human Disorders, Gerarda Cappuccio, William T Choi, Fatih Semerci, Jill A Rosenfeld, Toni Claire Tacorda, Guantong Qi, Anthony W Zoghbi, Yi Zhong, Hu Chen, Pengfei Liu, Zhandong Liu, Mirjana Maletić-Savatić

Duncan NRI Faculty and Staff Publications

Adult hippocampal neurogenesis, the process of generating new neurons, relies on a rare population of neural stem and progenitor cells (NPCs) within the dentate gyrus complex microenvironment. Discovering the specific genes that define these cells is vital yet challenging due to overlapping expression patterns, limiting detection of rare cell populations using traditional approaches. By employing the computational digital sorting algorithm (DSA) that deconvolves complex gene expression data based on pattern recognition, we identified 129 genes enriched in murine NPCs. We validated these genes against published single-cell RNA sequencing (scRNA-seq) data and discovered that 25 human orthologs were known to cause …

Gene Context Drift Identifies Drug Targets To Mitigate Cancer Treatment Resistance, Amir Jassim, Birgit V Nimmervoll, Sabrina Terranova, Erica Nathan, Linda Hu, Jessica T Taylor, Katherine E Masih, Lisa Ruff, Matilde Duarte, Elizabeth Cooper, Gunjan Katyal, Melika Akhbari, Reuben J Gilbertson, Jennifer C Coleman, Joseph S Toker, Colton Terhune, Gabriel Balmus, Stephen P Jackson, Hailong Liu, Tao Jiang, Michael D Taylor, Kui Hua, Jean E Abraham, Mariella G Filbin, Anthony Hill, Anarita Patrizi, Neil Dani, Aviv Regev, Maria K Lehtinen, Richard J Gilbertson

Faculty, Staff and Students Publications

Cancer treatment often fails because combinations of different therapies evoke complex resistance mechanisms that are hard to predict. We introduce REsistance through COntext DRift (RECODR): a computational pipeline that combines co-expression graph networks of single-cell RNA sequencing profiles with a graph-embedding approach to measure changes in gene co-expression context during cancer treatment. RECODR is based on the idea that gene co-expression context, rather than expression level alone, reveals important information about treatment resistance. Analysis of tumors treated in preclinical and clinical trials using RECODR unmasked resistance mechanisms -invisible to existing computational approaches- enabling the design of highly effective combination treatments …

Coenzyme Q Headgroup Intermediates Can Ameliorate A Mitochondrial Encephalopathy, Guangbin Shi, Claire Miller, Sota Kuno, Alejandro G Rey Hipolito, Salsabiel El Nagar, Giulietta M Riboldi, Megan Korn, Wyatt C Tran, Zixuan Wang, Lia Ficaro, Tao Lin, Quentin Spillier, Begoña Gamallo-Lana, Drew R Jones, Matija Snuderl, Soomin C Song, Adam C Mar, Alexandra L Joyner, Roy V Sillitoe, Robert S Banh, Michael E Pacold

Duncan NRI Faculty and Staff Publications

Decreased brain levels of coenzyme Q10 (CoQ10), an endogenously synthesized lipophilic antioxidant1,2, underpin encephalopathy in primary CoQ10 deficiencies3,4 and are associated with common neurodegenerative diseases and the ageing process5,6. CoQ10 supplementation does not increase CoQ10 pools in the brain or in other tissues. The recent discovery of the mammalian CoQ10 headgroup synthesis pathway, in which 4-hydroxyphenylpyruvate dioxygenase-like protein (HPDL) makes 4-hydroxymandelate (4-HMA) to synthesize the CoQ10 headgroup precursor 4-hydroxybenzoate (4-HB)7, offers an opportunity to pharmacologically restore CoQ10 synthesis and mechanistically treat CoQ10 deficiencies. To test whether 4-HMA …

Adaptive Filters At The First Olfactory Synapse, Elizabeth H Moss, Benjamin R Arenkiel

Duncan NRI Faculty and Staff Publications

The olfactory system is able to filter odor representations based on attention and learning. Two PLoS Biology studies reveal how short axon cells in the olfactory bulb integrate cholinergic input from the basal forebrain to dynamically regulate olfactory input.

Folliculin Deletion In The Mouse Kidney Results In Cystogenesis Of The Loops Of Henle Via Aberrant Tfeb Activation, Ola Shalaby, Tomoko Ohmori, Koichiro Miike, Shunsuke Tanigawa, Luh Ade Wilan Krisna, Alessia Calcagnì, Andrea Ballabio, Yoshiaki Kubota, Laura S Schmidt, W Marston Linehan, Takaaki Ito, Masaya Baba, Ryuichi Nishinakamura

Duncan NRI Faculty and Staff Publications

The mammalian kidney contains numerous nephrons connected to the collecting ducts, and each nephron consists of a glomerulus, a proximal tubule, the loop of Henle (LoH), and a distal tubule. Folliculin (FLCN) is a causative gene for Birt-Hogg-Dubé syndrome, which is characterized by a variety of manifestations, including renal cysts and cancer. Although deletion of Flcn in the mouse collecting duct and distal nephron leads to cyst formation, its precise role in the entire nephron remains unclear. Herein, nephron-specific Flcn knockout mice exhibited cystogenesis along the entire nephron segments, most prominent in the LoH, preceded by an irregularly shaped lumen …

Heterozygous Variants In Plcg1 Affect Hearing, Vision, Cardiac, And Immune Function, Mengqi Ma, Yiming Zheng, Mingxi Deng, Shenzhao Lu, Xueyang Pan, Xi Luo, Michelle Etoundi, David Li-Kroeger, Kim C Worley, Lindsay C Burrage, Lauren S Blieden, Aimee Allworth, Wei-Liang Chen, Giuseppe Merla, Barbara Mandriani, Catherine E Otten, Pierre Blanc, Jill A Rosenfeld, Debdeep Dutta, Shinya Yamamoto, Michael F Wangler, Ian A Glass, Jingheng Chen, Elizabeth Blue, Paolo Prontera, Jeremie Rosain, Sandrine Marlin, Seema R Lalani, Hugo J Bellen, Undiagnosed Diseases Network

Duncan NRI Faculty and Staff Publications

Phospholipase C isozymes (PLCs) hydrolyze phosphatidylinositol 4,5-bisphosphate (PIP₂) into inositol 1,4,5-trisphosphate (IP₃) and diacylglycerol (DAG), important signaling molecules involved in many cellular processes including Ca²⁺ release from the endoplasmic reticulum (ER). PLCG1 encodes the PLCγ1 isozyme that is broadly expressed. Hyperactive somatic mutations of PLCG1 are observed in multiple cancers, but only one germline variant has been reported. Here, we describe seven individuals with heterozygous missense variants in PLCG1 [p.(Asp1019Gly), p.(His380Arg), p.(Asp1165Gly), and p.(Leu597Phe)] who present with hearing impairment (5/7), ocular pathology (4/7), cardiac septal defects (3/6), and various immunological issues (5/7). To model these …

A Protective Role Of Src-1 Against Aging Associated Cognitive Decline, Hesong Liu, Yongjie Yang, Jonathan C Bean, Yang He, Hailan Liu, Rambabu Majji, Chen Liang, Nan Zhang, Meng Yu, Longlong Tu, Qingzhuo Liu, Yue Deng, Kristine M Conde, Na Yin, Mengjie Wang, Yongxiang Li, Junying Han, Sanika Vattakuzhiyil Jossy, Megan Elyse Burt, Hari Krishna Yalamanchili, Chunmei Wang

Duncan NRI Faculty and Staff Publications

Introduction: Research indicates a strong correlation between obesity and the risk of dementia, both are linked to steroid receptor coactivator-1 (SRC-1), a transcriptional coactivator.

Methods: We used RNA sequencing analysis (RNA-Seq) to investigate the transcriptome of SRC-1-KO mice, and identified S100 calcium-binding protein A6 (S100A6), an AD associated gene, as one target of SRC-1. We tested cognitive behaviors in SRC-1-KO mice and mice with a humanized SRC-1 mutation (SRC-1L1376P), and performed promoter luciferase assays on S100A6.

Results: Loss of SRC-1 caused alterations in gene signatures that are commonly associated with neurodegenerative diseases, including AD, and diminished the neural plasticity of …

Gm-Csf Production By Immune Cells In Steady State And Autoimmune Neuroinflammation Mapped Using Fate Reporting Mice, Gholamreza Azizi, Javad Rasouli, Hamed Naziri, Michael V. Gonzalez, James Garifallou, Guang-Xian Zhang, Bogoljub Ciric, Abdolmohamad M. Rostami

Department of Neurology Faculty Papers

INTRODUCTION: GM-CSF is a pro-inflammatory cytokine that promotes an inflammatory phenotype in myeloid cells. The extent and pattern of GM-CSF expression in immune cells have not been fully elucidated. Our goal was to advance this topic using novel GM-CSF reporter/fate reporter transgenic mice.

METHODS: We tracked ongoing and past GM-CSF expression in various immune cells from multiple organs, in steady-state and autoimmune inflammation of the central nervous system (CNS).

RESULTS: The GM-CSF expression patterns varied by cell type and organ, with CD4

DISCUSSION: These findings identified distinct GM-CSF cellular sources across organs, highlighting the transient nature of GM-CSF expression and …

Rare Variants In Bmal1 Are Associated With A Neurodevelopmental Syndrome, Vishnu Anand Cuddapah, Dechun Chen, Bumsik Cho, Rebecca Moore, Mohnish Suri, Hana Safraou, Frederic Tran-Mau-Them, Ashley Wilson, Jacqueline Odgis, Atteeq U Rehman, Carol Saunders, Shiva Ganesan, Vaidehi Jobanputra, Stephen W Scherer, Ingo Helbig, Amita Sehgal

Duncan NRI Faculty and Staff Publications

Children with neurodevelopmental disorders exhibit highly penetrant sleep and circadian dysfunction, but the underlying mechanisms are unclear. We asked whether a subset of individuals with neurodevelopmental disorders might have genetic variants in genes known to drive circadian rhythms. Through international collaboration, we identified ten individuals with very rare genetic variants in BMAL1, a core component of the molecular clock. These individuals exhibited overlapping signs and symptoms including developmental delay, autism spectrum disorder, and variably penetrant marfanoid features. We functionally tested the identified BMAL1 variants in cell culture and in vivo and found disrupted BMAL1 function. These findings demonstrate that …

De Novo And Inherited Variants In Ddx39b Cause A Novel Neurodevelopmental Syndrome, Kevin T A Booth, Sharayu V Jangam, Martin M C Chui, Kayla Treat, Lorenzo Graziani, Alessia Soldano, Yao Ruan, Jeffrey Wan-Hei Hui, Kerry White, Celanie K Christensen, Ty Lynnes, Shinya Yamamoto, Oguz Kanca, Mandy H Y Tsang, Sally A Lynch, Sureni V Mullegama, Julia Baptista, Daniela Iancu, Shelagh K Joss, Sandra Y Y Wong, Christopher C Y Mak, Anna K Y Kwong, Hugo J Bellen, Erin Conboy, Remo Sanges, Anskar Yu-Hung Leung, Michael F Wangler, Brian H Y Chung, Francesco Vetrini

Duncan NRI Faculty and Staff Publications

DDX39B is a conserved member of the DEAD-box family of ATP-dependent RNA helicases, critical in mRNA metabolism across eukaryotes. DDX39B is also a core component of the TRanscription-EXport (TREX) super protein complex, and recent studies have highlighted the important role of its subunits in neurodevelopmental disorders. Here, we describe six individuals from five families, four harbouring de novo missense variants in DDX39B and one with an inherited splicing variant, presenting with variable developmental delay, congenital hypotonia, epilepsy, short stature, skeletal abnormalities, dysmorphic features and microcephaly in three patients.

3D molecular modelling predicts these variants would alter protein structure. In vitro …

The Synaptic Architecture Of Layer 5 Thick Tufted Excitatory Neurons In Mouse Visual Cortex, Agnes L Bodor, Casey M Schneider-Mizell, Chi Zhang, Leila Elabbady, Alex Mallen, Andi Bergeson, Derrick Brittain, Joann Buchanan, Daniel J Bumbarger, Rachel Dalley, Clare Gamlin, Emily Joyce, Daniel Kapner, Sam Kinn, Gayathri Mahalingam, Sharmishtaa Seshamani, Shelby Suckow, Marc Takeno, Russel Torres, Wenjing Yin, J Alexander Bae, Manuel A Castro, Sven Dorkenwald, Akhilesh Halageri, Zhen Jia, Chris Jordan, Nico Kemnitz, Kisuk Lee, Kai Li, Ran Lu, Thomas Macrina, Eric Mitchell, Shanka Subhra Mondal, Shang Mu, Barak Nehoran, Sergiy Popovych, William Silversmith, Nicholas L Turner, Szi-Chieh Yu, William Wong, Jingpeng Wu, Brendan Celii, Luke Campagnola, Stephanie C Seeman, Tim Jarsky, Naixin Ren, Anton Arkhipov, Jacob Reimer, H Sebastian Seung, R Clay Reid, Forrest Collman, Nuno Maçarico Da Costa

Faculty, Staff and Students Publications

Despite significant progress in characterizing neocortical cell types, a complete understanding of the synaptic connections of individual excitatory cells remains elusive. This study investigates the connectivity of mouse visual cortex thick tufted layer 5 pyramidal cells, also known as extratelencephalic neurons (L5-ETns), using a 1 mm3 publicly available electron microscopy dataset. The analysis reveals that, in their immediate vicinity, L5-ETns primarily establish connections with a group of inhibitory cell types, which, in turn, specifically target the L5-ETns back. The most common excitatory targets of L5-ETns are layer 5 intertelencephalic neurons (L5-ITns) and layer 6 (L6) pyramidal cells, whereas synapses with …

Rapid Dissection And Dissociation Of The Mouse Olfactory Epithelium For Single-Nucleus Suspensions, Benjamin D W Belfort, Anthony M Insalaco, Claude C Chew, Johnathan D Jia, Julia Younis, Benjamin R Arenkiel

Duncan NRI Faculty and Staff Publications

The murine olfactory epithelium is the initial entry point of the olfactory system, housing various cell types that include olfactory sensory neurons, their regenerating progenitors, and support cells. Olfactory sensory neurons transduce chemical odorants into neural signals, yet the mechanisms underlying how these cells develop and turnover, create synapses with the olfactory bulb, and regulate their odorant receptors remain areas of intense study. Located on the dorsal aspect of the nasal cavity, the olfactory epithelium adheres to intricate bony structures known as turbinates. This anatomy poses unique challenges for its extraction and dissociation, especially in the context of preparing viable …

Folliculin Depletion Results In Liver Cell Damage And Cholangiocarcinoma Through Mit/Tfe Activation, Bruno Maria Custode, Francesco Annunziata, Felipe Dos Santos Matos, Valentina Schiano, Veronica Maffia, Milena Lillo, Rita Colonna, Rossella De Cegli, Andrea Ballabio, Nunzia Pastore

Duncan NRI Faculty and Staff Publications

Mutations in the tumor suppressor gene Folliculin (FLCN) are responsible for Birt-Hogg-Dube’ (BHD) syndrome, a rare inherited condition that predisposes affected individuals to skin tumors, pulmonary cysts, and kidney tumors. FLCN regulates key cellular pathways, including TFEB, TFE3, and mTORC1, which are critical for maintaining cell homeostasis. Loss of FLCN leads to both hyperactivation of mTORC1 and constitutive activation of TFEB and TFE3, contributing to tumorigenesis. While previous studies showed that Flcn liver-specific conditional knockout (FlcnLiKO) mice are protected from developing liver fibrosis and damage upon high-fat diet exposure, the potential role of FLCN loss in liver carcinogenesis …

Sleep Drive, Not Total Sleep Amount, Increases Seizure Risk, Vishnu Anand Cuddapah, Cynthia T Hsu, Fernanda Valle Sirias, Yongjun Li, Hrishit M Shah, Christopher Saul, Samantha Killiany, Camilo Guevara, Joy Shon, Zhifeng Yue, Gabrielle L Gionet, Mary E Putt, Amita Sehgal

Duncan NRI Faculty and Staff Publications

Sleep loss has been associated with increased seizure risk since antiquity. Using automated video detection of spontaneous seizures in Drosophila epilepsy models, we show that seizures worsen only when sleep restriction raises homeostatic "sleep drive," not simply when total sleep amount falls. This is supported by the paradoxical finding that acute activation of sleep-promoting circuits worsens seizures, because it increases sleep drive without changing sleep amount. Sleep-promoting circuits become hyperactive after sleep loss and are associated with increased whole-brain activity. During sleep restriction, optogenetic inhibition of sleep-promoting circuits to reduce sleep drive protects against seizures. Downregulation of the 5HT1A serotonin …

Oxytocin Reduces Asymmetries In Dominance Relationships Between Pairs Of Captive Female Lions, Jessica C Burkhart, Abby Guthmann, Evianne M Dubois, Sarah R Heilbronner, Craig Packer

Faculty, Staff and Students Publications

Free-ranging female African lions maintain symmetrical social relationships by respecting each other's "ownership" of valuable food items rather than by supplanting subordinates according to well-defined dominance hierarchies. However, captivity often skews relationships in captive carnivores, hence we investigated whether captive female lions demonstrate obvious dominance relationships. Oxytocin has been shown to elicit context-specific impacts that equalize dominant subordinate relationships, thus we hypothesized that oxytocin would reduce any asymmetries found between dominants and subordinates in captive lions. We designed two experimental protocols for investigating pairwise relationships. We first identified dominant individuals by performing neutral trials that allowed each female equal opportunity …

Distinguishing Pex2 And Pex16 Gene Variant Severity For Mild, Severe And Atypical Peroxisome Biogenesis Disorders, Vanessa A Gomez, Oguz Kanca, Sharayu V Jangam, Saurabh Srivastav, Jonathan C Andrews, Michael F Wangler

Duncan NRI Faculty and Staff Publications

Peroxisomal biogenesis disorders (PBD) are autosomal recessive diseases caused by mutations in specific PEX genes that impair peroxisome formation, leading to multi-systemic failure. Symptoms vary, even in patients with variants in the same PEX gene. Our goal is to select PEX mutations and use Drosophila to model a severity spectrum based on genotype-phenotype correlations. Utilizing KozakGAL4 (KZ) cassettes, we replaced the coding sequence of Pex with a GAL4 driver, ideal for making 'humanized' flies in which human PEX can replace the fly loss. We generated Pex2KZ and Pex16KZ lines and assessed them in various behavior assays, confirming their severe phenotypes. …

C-Terminal Frameshift Variants In Gpkow Are Associated With A Multisystemic X-Linked Disorder, Jung-Wan Mok, Laura Mackay, Maria Blazo, Elizabeth Mizerik, Jozef Gecz, Renee Carroll, Mathilde Nizon, Sophie Rondeau, Madeleine Joubert, Silvestre Cuinat, Wallid Deb, Fernanda Valle Sirias, Monika Weisz-Hubshman, Shamika Ketkar, Urszula Polak, Alyssa A Tran, Debra Kearney, Neil A Hanchard, Oguz Kanca, Michael F Wangler, Hugo J Bellen, Brendan H Lee, Shinya Yamamoto, Keren Machol

Duncan NRI Faculty and Staff Publications

Purpose: GPKOW, a gene on the X-chromosome, encodes a nuclear RNA-binding protein important in messenger RNA (mRNA) processing as a spliceosome subunit. This work aims to establish GPKOW as a disease-associated gene.

Methods: We describe 3 males from 2 unrelated families with hemizygous frameshift variants affecting the last exon of GPKOW p.(Arg441SerfsTer30) and p.(Ser444GlufsTer28). The effect of p.(Ser444GlufsTer28) on gene expression was evaluated in patient's fibroblasts. In vivo studies in Drosophila melanogaster targeting the sole GPKOW fly ortholog, CG10324 (Gpkow) were performed.

Results: Clinical presentations included intrauterine growth restriction, microcephaly/microencephaly, and eye, brain, skin, and skeletal abnormalities. Heterozygote females presented …

Formation Of An Expanding Memory Representation In The Hippocampus, Sachin P Vaidya, Guanchun Li, Raymond A Chitwood, Yiding Li, Jeffrey C Magee

Faculty, Staff and Students Publications

How brain networks connected by labile synapses store new information without catastrophically overwriting previous memories remains poorly understood. To examine this, we tracked the same population of hippocampal CA1 place cells (PCs) as mice learned a task for 7 days. We found evidence of memory formation as both the number of PCs maintaining a stable place field and the stability of individual PCs progressively increased across the week until most of the representation was composed of long-term stable PCs. The stable PCs disproportionately represented task-related learned information, were retrieved earlier within a behavioral session and showed a strong correlation with …

Integrating Endocannabinoid Signaling, Cck Interneurons, And Hippocampal Circuit Dynamics In Behaving Animals, Shreya Malhotra, Florian Donneger, Jordan S Farrell, Barna Dudok, Attila Losonczy, Ivan Soltesz

Faculty, Staff and Students Publications

The brain's endocannabinoid signaling system modulates a diverse range of physiological phenomena and is also involved in various psychiatric and neurological disorders. The basic components of the molecular machinery underlying endocannabinoid-mediated synaptic signaling have been known for decades. However, limitations associated with the short-lived nature of endocannabinoid lipid signals had made it challenging to determine the spatiotemporal specificity and dynamics of endocannabinoid signaling in vivo. Here, we discuss how novel technologies have recently enabled unprecedented insights into endocannabinoid signaling taking place at specific synapses in behaving animals. In this review, we primarily focus on cannabinoid-sensitive inhibition in the hippocampus in …

Glucagon-Like Peptide-1 Receptor Agonists In Neurodegenerative Diseases: Promises And Challenges, Zhi Dong Zhou, Lingxiao Yi, Karolina Popławska-Domaszewicz, Kallol Ray Chaudhuri, Joseph Jankovic, Eng King Tan

Faculty, Staff and Students Publications

Glucagon-like peptide-1 (GLP-1) receptor agonists (GRA) belong to a class of compounds that reduce blood glucose and energy intake by simulating actions of endogenous incretin hormone GLP-1 after it is released by the gut following food consumption. They are used to treat type 2 diabetes mellitus (T2DM) and obesity and have systemic effects on various organs, including the brain, liver, pancreas, heart, and the gut. Patients with T2DM have a higher risk of developing neurodegenerative diseases (NDs), including Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS) and Huntington's disease (HD), accompanied by more severe motor deficits and faster …

The Metastatic Role Of The Cxcl10-Cxcr3 Axis And Its Therapeutic Potential In Osteosarcoma, Benjamin B Gyau, Junyan Wang, Xiang Chen, Margaret A Clement, Zoe D Man, Angela M Major, Mathew C Weiser, Jun Xu, John Hicks, Tsz-Kwong Man

Faculty, Staff and Students Publications

The CXCL10-CXCR3 axis regulates immunity, tumorigenesis, and metastasis in multiple cancers. Yet, its roles in osteosarcoma (OS), the predominant pediatric malignant bone tumor, are not fully defined. Our prior work has shown that elevated serum CXCL10 levels correlate with poor OS prognosis. The current study delves deeper by investigating how CXCL10-mediated CXCR3 signaling influences OS growth and metastatic spread. In vitro, CXCL10 and related CXCR3 ligands (CXCL4, CXCL9, and CXCL11) enhanced OS tumor cell migration. In an orthotopic xenograft mouse model with a newly created CXCR3 knockout (KO) mutant, tumor growth and lung metastasis decreased significantly when compared with …

The Cgas/Sting Pathway: Friend Or Foe In Regulating Cardiomyopathy, Weiyue Wang, Yuanxu Gao, Hyun Kyoung Lee, Albert Cheung-Hoi Yu, Markus Kipp, Hannes Kaddatz, Jiangshan Zhan

Duncan NRI Faculty and Staff Publications

Inflammation is a central hallmark of cardiomyopathy, where misdirected immune responses contribute to chronic myocardial dysfunction. Among the emerging molecular mechanisms implicated in this process, the cyclic GMP-AMP synthase (cGAS)/stimulator of interferon genes (STING) signaling pathway has garnered increasing attention. Acting as a key cytosolic DNA sensor, the cGAS/STING pathway orchestrates inflammatory responses triggered by microbial infections or endogenous cellular stressors such as autophagy and apoptosis. Despite its pivotal role, the precise molecular mechanisms regulating this pathway and its role in cardiomyopathy-associated inflammation remain poorly understood and subject to ongoing debate. To address this scientific gap, we first reviewed key …

A Hierarchy Of Pdz Domain Scaffolding Proteins Clusters The Kv1 K+ Channel Protein Complex At The Axon Initial Segment, Wei Zhang, Victoria L Palfini, Yu Wu, Xiaoyun Ding, Allison J Melton, Yudong Gao, Yuki Ogawa, Matthew N Rasband

Faculty, Staff and Students Publications

Action potentials are initiated and modulated at the axon initial segment (AIS) by highly clustered ion channels. Voltage-gated Kv1 potassium channels underlie most outward AIS K+ current. AIS Kv1 channels exist in a large protein complex including ADAM22, Caspr2, and LGI1. However, their clustering mechanisms remain unknown. Because Kv1 channels have a highly conserved PDZ-binding motif, we used CRISPR-based genome editing to screen 18 PDZ domain-containing proteins identified in our previous AIS proximity proteome for their AIS localization. Among these, we found that the scaffolding proteins SCRIB and PSD93 are highly enriched at the AIS. Using CRISPR-mediated knockout, cell surface …

Hippocampal-Prefrontal Functional Neural Networks In A Rat Model Of Fragile X Syndrome Are Poorly Organized With Limited Resiliency, Mohamed Ouardouz, Patrick Jasinski, Mohamed Khalife, J. Matthew Mahoney, Amanda E. Hernan, Rod C. Scott

Department of Neurology Faculty Papers

Fragile X Syndrome (FXS) is a common cause of autism spectrum symptoms. The genetic mutation results in multiple molecular alterations that are hypothesized to negatively impact neural circuit development although the nature of any functional neural dynamic consequences remain unclear. Therefore, the characteristics of hippocampal-prefrontal (H-PFC) network dysfunction were investigated in a rat model of FXS. FMR-KO and control rats underwent behavioral tests assessing sociability, memory, and anxiety to validate and replicate previously recognized deficits. Single-unit electrophysiology in the H-PFC circuit during exploration was used to measure patterns of action potential firing that were then compared between groups using generalized …

Alzheimer’S Disease Protective Allele Of Clusterin Modulates Neuronal Excitability Through Lipid-Droplet-Mediated Neuron-Glia Communication, Xiaojie Zhao, Yan Li, Siwei Zhang, Ari Sudwarts, Hanwen Zhang, Alena Kozlova, Matthew J Moulton, Lindsey D Goodman, Zhiping P Pang, Alan R Sanders, Hugo J Bellen, Gopal Thinakaran, Jubao Duan

Duncan NRI Faculty and Staff Publications

Background: Genome-wide association studies (GWAS) of Alzheimer's disease (AD) have identified a plethora of risk loci. However, the disease variants/genes and the underlying mechanisms have not been extensively studied.

Methods: Bulk ATAC-seq was performed in induced pluripotent stem cells (iPSCs) differentiated various brain cell types to identify allele-specific open chromatin (ASoC) SNPs. CRISPR-Cas9 editing generated isogenic pairs, which were then differentiated into glutamatergic neurons (iGlut). Transcriptomic analysis and functional studies of iGlut co-cultured with mouse astrocytes assessed neuronal excitability and lipid droplet formation.

Results: We identified a putative causal SNP of CLU that impacted neuronal chromatin accessibility to transcription-factor(s), with …

Metastatic Medulloblastoma Remodels The Local Leptomeningeal Microenvironment To Promote Further Metastatic Colonization And Growth, Namal Abeysundara, Alexandra Rasnitsyn, Vernon Fong, Alexander Bahcheli, Randy Van Ommeren, Kyle Juraschka, Maria Vladoiu, Winnie Ong, Bryn Livingston, Pasqualino De Antonellis, Michelle Ly, Borja López Holgado, Olga Sirbu, Shahrzad Bahrampour, Hyun-Kee Min, Jerry Fan, Carolina Nor, Abhirami Visvanathan, Jiao Zhang, Hao Wang, Lei Qin, Ning Huang, Jonelle Pallotta, Tajana Douglas, Esta Mak, Haipeng Su, Karen Ng, Kevin Yang Zhang, Craig Daniels, Calixto-Hope G Lucas, Charles G Eberhart, Hailong Liu, Tao Jiang, Faiyaz Notta, Vijay Ramaswamy, Jüri Reimand, Marco Gallo, Jeremy N Rich, Xiaochong Wu, Xi Huang, Michael D Taylor

Faculty, Staff and Students Publications

Leptomeningeal metastases are the major source of morbidity and mortality for patients with medulloblastoma. The biology of the leptomeningeal metastases and the local tumour microenvironment are poorly characterized. Here we show that metastasis-associated meningeal fibroblasts (MB-MAFs) are transcriptionally distinct and signal extensively to tumour cells and the tumour microenvironment. Metastatic cells secrete platelet-derived growth factor (PDGF) ligands into the local microenvironment to chemotactically recruit meningeal fibroblasts. Meningeal fibroblasts are reprogrammed to become MB-MAFs, expressing distinct transcriptomes and secretomes, including bone morphogenetic proteins. Active bone morphogenetic protein signalling and co-implantation of tumour cells with MB-MAFs enhances the colonization of the leptomeninges …

Mapping The Developmental Profile Of Ventricular Zone-Derived Neurons In The Human Cerebellum, Anders W Erickson, Henry Tan, Liam D Hendrikse, Jake Millman, Zachary Thomson, Joseph Golser, Omar Khan, Guanyi He, Kathleen Bach, Arpit Suresh Mishra, Janja Kopic, Zeljka Krsnik, Ferechte Encha-Razavi, Giulia Petrilli, Fabien Guimiot, Evelina Silvestri, Kimberly A Aldinger, Michael D Taylor, Kathleen J Millen, Parthiv Haldipur

Faculty, Staff and Students Publications

The cerebellar ventricular zone (VZ) is the primary source of progenitors that generate cerebellar GABAergic neurons, including Purkinje cells (PCs) and interneurons (INs). This study provides detailed characterization of human cerebellar GABAergic neurogenesis using transcriptomic and histopathological analyses and reveals conserved and unique features compared to rodents. We show that the sequential progression of neurogenesis is conserved and occurs before 8 postconception weeks. Notably, PC differentiation occurs in the outer subventricular zone (SVZ), a region absent in the mouse cerebellum. Human PCs are generated during a compact two-week period before the onset of cerebral cortex histogenesis. A subset of human …

The Potential Of Brain Organoids In Addressing The Heterogeneity Of Synucleinopathies, Xiao-Jun Diao, Claudio Soto, Fei Wang, Yu Wang, Yun-Cheng Wu, Abhisek Mukherjee

Faculty, Staff and Student Publications

Synucleinopathies are a group of diseases characterized by neuronal and glial accumulation of α-synuclein (aSyn) linked with different clinical presentations, including Parkinson's disease (PD), Parkinson's disease with dementia (PDD), Dementia with Lewy Bodies (DLB) and Multiple system atrophy (MSA). Interestingly, the structure of the aSyn aggregates can vary across different synucleinopathies. Currently, it is unclear how the aSyn protein can aggregate into diverse structures and affect distinct cell types and various brain regions, leading to different clinical symptoms. Recent advances in induced pluripotent stem cells (iPSCs)-based brain organoids (BOs) technology provide an unprecedented opportunity to define the etiology of synucleinopathies …