Neurosciences Commons^™

Microglia Sensing Of Peripheral Signals That Bridge The Brain And Body, Claire E Young, Melanie A Samuel

Faculty, Staff and Students Publications

Microglia are the resident immune cell of the brain, and alterations in microglia signaling have been implicated in many neurodegenerative disorders. While microglia responses to central cues and other brain cell types are well documented, studies are increasingly investigating the impact of peripherally derived signals on microglia function. A diverse array of peripheral cues, including dietary components, hormones, and bacteria metabolites and components from the microbiome cross the blood brain barrier and directly influence microglia state through ligand-receptor interactions. This review highlights the complexity of brain-body interactions from the perspective of microglia function and proposes the idea that microglia could …

Injectable Microparticle-Nanoliposome Hydrogel For Extended Release Of Small Hydrophilic Molecules, Gil Aizik, Wonmin Choi, Claire A Ostertag-Hill, Matthew Torre, Daniel S Kohane

Duncan NRI Faculty and Staff Publications

Achieving sustained local release of small hydrophilic drugs is challenging and is particularly important when the drugs are toxic. To address these challenges, we developed a hybrid system comprising drug-containing microparticles embedded within a nanoliposomal hydrogel matrix. This system forms through salt-induced gelation using physiologically relevant sodium chloride concentrations (0.9%), allowing for microparticle encapsulation without harsh chemical processes. In vitro, the hybrid system exhibited a slower release of encapsulated cargo compared to microparticles or hydrogel alone. In vivo proof of principle was provided with tetrodotoxin (TTX), a small hydrophilic and ultrapotent local anesthetic, which can cause systemic toxicity if the …

Biliverdin Reductase A Is A Major Determinant Of Protective Nrf2 Signaling, Chirag Vasavda, Ruchita Kothari, Navneet Ammal Kaidery, Suwarna Chakraborty, Sunil Jamuna Tripathi, Ryan S Dhindsa, Cristina Ricco, Shruthi Shanmukha, Samaneh Saberi, Julia E Lefler, Priyanka Kothari, Kalyani Chaubey, Adele M Snowman, Michael C Ostrowski, Eugenio Barone, Lakshminarayan M Iyer, L Aravind, Sudarshana M Sharma, Andrew A Pieper, Bobby Thomas, Solomon H Snyder, Bindu D Paul

Duncan NRI Faculty and Staff Publications

Biliverdin reductase A (BVRA), the terminal enzyme in heme catabolism, generates the neuroprotective and lipophilic antioxidant bilirubin. Here, we identify a nonenzymatic role for BVRA in redox regulation. Through phylogenetic, genetic, biochemical, and enzymatic assays, we found that BVRA exerts critical nonenzymatic antioxidant activity. Transcriptomic analyses further revealed that BVRA physically and genetically interacts with nuclear factor erythroid-derived factor-like 2 (NRF2), a major transcriptional regulator of cellular redox signaling. ChIP-seq and RNA-seq analyses reveal that BVRA and NRF2 coordinate the expression of antioxidant genes, many of which are typically dysregulated in neurodegenerative conditions such as Alzheimer's disease. Thus, this noncanonical …

Atg Conjugation-Dependent/Independent Mechanisms Underlie Lysosomal Stress-Induced Tfeb Regulation, Shiori Akayama, Takayuki Shima, Tatsuya Kaminishi, Mengying Cui, Jlenia Monfregola, Kohei Nishino, Andrea Ballabio, Hidetaka Kosako, Tamotsu Yoshimori, Shuhei Nakamura

Duncan NRI Faculty and Staff Publications

TFEB, a master regulator of autophagy and lysosomal biogenesis, is activated by several cellular stresses including lysosomal damage, but its underlying mechanism is unclear. TFEB activation during lysosomal damage depends on the ATG conjugation system, which mediates lipidation of ATG8 proteins. Here, we newly identify ATG conjugation-independent TFEB regulation that precedes ATG conjugation-dependent regulation, designated Modes I and II, respectively. We reveal unique regulators of TFEB in each mode: APEX1 in Mode I and CCT7 and/or TRIP6 in Mode II. APEX1 interacts with TFEB independently of the ATG conjugation system, and is required for TFEB stability, while both CCT7 and …

Neuronal Activity-Dependent Gene Dysregulation In C9orf72 I3neuronal Models Of Als/Ftd Pathogenesis, Layla T. Ghaffari, Emily A. Welebob, Sarah E. Bond Newton, Ashley V. Boehringer, Kelly L. Cyliax, Piera Pasinelli, Davide Trotti, Aaron R. Haeusler

Farber Institute for Neuroscience Faculty Papers

The GGGGCC nucleotide repeat expansion (NRE) mutation in the C9ORF72 (C9) gene is the most common cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Neuronal activity plays an essential role in shaping biological processes within both healthy and neurodegenerative disease scenarios. Here, we show that at baseline conditions, C9-NRE-induced pluripotent stem cell-cortical neurons display aberrations in several pathways, including synaptic signaling and transcriptional machinery, potentially priming diseased neurons for an altered response to neuronal stimulation. Indeed, exposure to two pathophysiologically relevant stimulation modes, prolonged membrane depolarization or a blockade of K⁺ channels, followed by RNA sequencing, induces …

Hydrogen Sulfide Inhibits Recruitment Of Monocyte-Derived Tumor Associated Macrophages In Glioblastoma By Downregulating Cxcl12, Joseph Camarano, Morgan Roque, Gabrielle Gahn, Stephen Garrett Whipple, Danielle Terrell, Charles Ronkon, Jamie Toms, Anthony Sin, Bharat Guthikonda, Khatri Latha, Yuhui Yang, Xinggui Shen, Christopher G Kevil, Ganesh Rao, Sungho Lee

Faculty, Staff and Students Publications

Tumor associated macrophages (TAMs) directly contribute to the dismal prognosis of glioblastoma by preventing anti-tumor immunity and promoting tumor invasion and angiogenesis. Inhibiting TAM infiltration is a potential therapeutic strategy in glioblastoma, with several chemokine antagonists in early clinical development. Hydrogen sulfide, a gasotransmitter that regulates microglial accumulation in a wide range of CNS diseases, may be a novel therapeutic target to prevent TAM recruitment in glioblastoma. In this study, hydrogen sulfide concentrations were directly measured from 14 isocitrate dehydrogenase (IDH)-wildtype glioblastoma surgical samples and compared against overall survival as well as expression of TAM markers and chemokines. Effects of …

Enhanced Control Of Liposomal Drug Release By Drug-Aptamer Complexes, Xiangang Huang, Yang Li, Matthew Torre, Rachelle Shao, Wei Zhang, Zihan Wang, Daniel S Kohane, Christopher B Weldon

Duncan NRI Faculty and Staff Publications

Conventional diffusion-controlled drug delivery systems (DDS) can have undesirable initial burst release, leading to potential systemic toxicity, and the rate of basal release can deplete content, shortening the duration of effect. Here, it is hypothesized that conventional drug delivery systems-using liposomes as an example-can be enhanced by incorporation of an aptamer that binds specifically to the encapsulated drug. Affinity of the aptamer to the drug within liposomes (Lipo-Apt) would slow release. It is demonstrated that this approach works with a range of relatively small and hydrophilic molecules, including tetrodotoxin (TTX), serotonin (Ser), and kanamycin (Kan). The in vivo utility of …

Carbonic Anhydrase Inhibition Sensitizes Group 3 Medulloblastoma To Radiotherapy, Cory M Richman, Alexandra Rasnitsyn, Borja L Holgado, Maria Vladoiu, Namal Abeysundara, Sandra Majo, Sara Chabi, Lucie J Taunay, Hiromichi Suzuki, Ichiyo Shibahara, Joonas Haapasalo, Jonelle G Pallotta, Tajana Douglas, Kaitlin Kharas, Kyle Juraschka, Oliver Ocsenas, Sachin A Kumar, Kristiina Nordfors, Ana Guerreiro Stücklin, Raul A Suarez, Jiao Zhang, Xiaochong Wu, Craig Daniels, Livia Garzia, Jüri Reimand, Olivier Saulnier, Thomas E Merchant, Celio Pouponnot, David R Raleigh, Michael D Taylor, Pasqualino De Antonellis

Faculty, Staff and Students Publications

Group 3 (G3) medulloblastoma constitutes the most aggressive molecular subgroup, and nearly all patients present with metastases upon recurrence. Treatment for newly diagnosed medulloblastoma relies on a combination of maximal safe surgical resection, followed by chemotherapy and ionizing radiation, and no therapies have been shown to confer a survival benefit at the time of recurrence. Given the limited therapeutic options available for patients with medulloblastoma, especially at recurrence, and the incomplete understanding of the molecular mechanisms underlying resistance to treatment, we sought to uncover actionable targets and biomarkers that could help refine patient selection and treatment of newly diagnosed medulloblastoma …

Kmt2d Temporally Activates Neuronal Transcriptional Factor Genes To Mediate Cerebellar Granule Cell Differentiation, Shilpa S Dhar, Kyung-Pil Ko, Jinho Jang, Calena Brown-Abel, Tao Lin, Sharad Awasthi, Kaifu Chen, Roy V Sillitoe, Jae-Il Park, Min Gyu Lee

Duncan NRI Faculty and Staff Publications

Spatiotemporal gene expression is the fundamental feature of cellular differentiation, including neuron differentiation. The epigenetic mechanism underlying spatiotemporal gene regulation during in vivo neuron differentiation remains largely unknown. Granule cells (GCs) constitute the vast majority of neurons in the cerebellum, which contains most of neurons in the brain. Here, we show that

Adsl Deficiency Is A Secondary Mitochondrial Disease Affecting Organelle Homeostasis And Erk2/Akt Signaling In A Linear Genotype-Phenotype Relation, Matteo Bordi, Beatrice Testa, Claudia Compagnucci, Fiorella Colasuonno, Francesca Cipressa, Elisabetta Betterini, Andrea Mancini, Claudia Carsetti, Illari Salvatori, Caterina Ferraina, Ming Yang, Rossella De Cegli, Eugenio Del Prete, Chiara Veroni, Salvatore Rizza, Sofia Mauri, Elena Ziviani, Marina Macchiaiolo, Davide Vecchio, Filippo Maria Panfili, Teresa Rizza, Gerrit Weber, Rosalba Carrozzo, Alberto Ferri, Silvia Campello, Andrea Ballabio, Christian Frezza, Gianluca Cestra, Marco Tartaglia, Andrea Bartuli, Francesco Cecconi

Duncan NRI Faculty and Staff Publications

Adenylosuccinate lyase deficiency (ADSLd) is a rare autosomal recessive purine metabolism disorder with several clinical manifestations. While toxic substrate accumulation is a known hallmark, no additional molecular mechanisms have been established. Here, we show that ADSLd is associated with mitochondrial dysfunction, including increased fragmentation, impaired respiration, and reduced ATP production. The severity of mitochondrial impairment correlates with ADSLd pathology, especially in mitochondria-dependent tissues. We also identify defects in mitochondrial dynamics and transport linked to ERK2 and AKT suppression. Notably, overexpressing constitutively active ERK2 or supplementing purine intermediates partially rescues the mitochondrial phenotype. These findings suggest an alternative disease mechanism and …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

Templating Of Monomeric Alpha-Synuclein Results In Inflammation And Snpc Dopamine Neuron Death In A Genetic Mouse Model Of Induced Synucleinopathy, Matthew D. Byrne, Peyman Petramfar, Jae-Kyung Lee, Richard J. Smeyne

Department of Neuroscience Faculty Papers

While the etiology of most cases of Parkinson's disease (PD) are idiopathic, it has been estimated that 5-10% of PD arise from known genetic mutations. The first mutations described that leads to the development of an autosomal dominant form of PD are in the SNCA gene that codes for the protein alpha-synuclein (α-syn). α-syn is an abundant presynaptic protein that is natively disordered and whose function is still unclear. In PD, α-syn misfolds into multimeric b-pleated sheets that aggregate in neurons (Lewy Bodies/neurites) and spread throughout the neuraxis in a pattern that aligns with disease progression. Here, using IHC, HC, …

Sensory Neuron-Expressed Fgf13 Controls Nociceptive Signaling In Diabetic Neuropathy Models, Aditya K Singh, Matteo Bernabucci, Nolan M Dvorak, Zahra Haghighijoo, Jessica Di Re, Nana A Goode, Feni K Kadakia, Laura A Maile, Olumarotimi O Folorunso, Paul A Wadsworth, Cynthia M Tapia, Pingyuan Wang, Jigong Wang, Haiying Chen, Yu Xue, Jully Singh, Kali Hankerd, Isaac J Gamez, Makenna Kager, Vincent Truong, Patrick Walsh, Stephanie I Shiers, Nishka Kuttanna, Hanyue Liao, Margherita Marchi, Erika Salvi, Ilaria D'Amato, Daniela D'Amico, Parsa Arman, Catharina G Faber, Rayaz A Malik, Marina De Tommaso, Dan Ziegler, Krishna Rajarathnam, Thomas A Green, Peter M Grace, Matthew R Sapio, Michael J Iadarola, Gregory D Cuny, Diana S Chow, Giuseppe Lauria Pinter, Steve Davidson, Dustin P Green, Jun-Ho La, Jin Mo Chung, Jia Zhou, Theodore J Price, Elizabeth Salisbury, Subo Yuan, Fernanda Laezza

Faculty, Staff and Student Publications

Nociception involves complex signaling, yet intrinsic mechanisms bidirectionally regulating this process remain unexplored. Here, we show that the fibroblast growth factor 13 (FGF13)/Nav1.7 protein-protein interaction (PPI) complex bidirectionally modulates nociception, and that the FGF13/Nav1.7 ratio is upregulated in type 2 diabetic neuropathy (T2DN). PW164, an FGF13/Nav1.7 channel C-terminal tail domain (CTD) PPI interface inhibitor, which reduces complex assembly, selectively suppressed Na+ currents sensitized by capsaicin-induced activation of TRPV1 channels in human induced pluripotent stem cell-derived (hIPSC-derived) sensory neurons and inhibited mechanical and thermal hyperalgesia in mice. FGF13 silencing mimics PW164 activity in culture and in vivo. Conversely, ZL192, an FGF13 …

Retinal Ganglion Cell Migration And Viability Requires The Kinase Lkb1, Robert D Mackin, Ritika V Bhalla, Viktor Akhanov, Qudrat T Abdulwahab, Courtney A Burger, Melanie A Samuel

Faculty, Staff and Students Publications

The arrangement of neurons into ordered layers underlies circuit function in many nervous system regions. This is particularly true in the mammalian retina. Here, fate-committed retinal ganglion cells (RGCs) migrate from the apical to the inner retina, where they form connections that enable vision. The mechanisms that permit ganglion cell migration and whether distinct ganglion cell types use different migration modes are unknown. We show that the serine/threonine kinase LKB1 regulates ganglion cell migration and nuclear positioning. In the absence of LKB1, many ganglion cells remain in the apical retina. Misplaced cells show modified morphologies and display altered cytoskeletal proteins. …

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. …