Neurology Commons^™

Intravascular Immune Cell Labeling As A Critical Methodological Tool For Characterizing Cd4+ T Cells In The Lung In Eae, Gholamreza Azizi, Mohamad Rostami

Department of Neurology Faculty Papers

INTRODUCTION: Growing evidence highlights the lung -brain axis as a key contributor to CNS autoimmunity. However, accurate characterization of lung immune cells remains technically challenging because standard transcardial perfusion does not eliminate the lung's extensive marginated intravascular leukocyte pool, allowing circulating cells to contaminate analyses of the lung parenchyma.

METHODS: Experimental autoimmune encephalomyelitis (EAE) was induced in mice by immunization with MOG35-55 peptide in complete Freund's adjuvant, followed by pertussis toxin administration. Lung mononuclear cells were isolated after intravascular (IV) CD45 labeling, transcardial perfusion, and enzymatic digestion. Immune cell populations and intracellular cytokine production were analyzed by multicolor flow cytometry …

Selective Loss Of Primary Cilia And Neurotrophic Signaling In G51d Α-Synuclein Mice Highlights A Common Pathway To Parkinson’S Disease, Yu-En Lin, Ebsy Jaimon, Youngdoo Kim, Annabeth Loftman, Aaran Vijayakumaran, Benjamin D W Belfort, Claire Y Chiang, Benjamin R Arenkiel, Huda Y Zoghbi, Suzanne R Pfeffer

Duncan NRI Faculty and Staff Publications

Parkinson's disease is characterized by dopaminergic neuron loss and accumulation of α-synuclein aggregates in the brain. G51D α-synuclein knock-in mice provide a genetically and clinically relevant model of disease, exhibiting early olfactory deficits, age-dependent motor impairment, and progressive phospho-α-synuclein accumulation. In multiple Parkinson's disease models, striatal cholinergic and parvalbumin interneurons, as well as astrocytes, lose primary cilia and the neurotrophic signaling needed to sustain dopaminergic neurons. We show here that G51D α-synuclein mice share these phenotypes. Phospho-Ser129 α-synuclein accumulation correlates with cilia loss in cholinergic interneurons but not in spiny projection neurons that accumulate higher phospho-α-synuclein levels. In the piriform …

Th17 Effector Cytokines Induce Shared And Distinct Microglial And Endothelial Cell Responses In A Mouse Model For Post-Streptococcal Encephalitis, Charlotte Wayne, Uğur Akcan, Travis Faust, Violeta Durán-Laforet, Danny Jamoul, Luca Bremner, Nicole Ampatey, Büşra Akcan, Sarah Ho, Bogoljub Ciric, Shannon Delaney, Wendy Vargas, Susan Swedo, Vilas Menon, Dorothy Schafer, Tyler Cutforth, Dritan Agalliu

Department of Neurology Faculty Papers

Group A Streptococcus (GAS) infections cause neuropsychiatric complications in children, but the mechanisms linking peripheral infection to brain dysfunction remain unclear. Using mouse genetics, single-cell RNA sequencing, and spatial transcriptomics, we show that GAS infections induce inflammatory transcriptional programs in microglia and brain endothelial cells (BECs), accompanied by loss of blood-brain barrier (BBB) gene expression in female mice. Spatial transcriptomic analyses reveal that GAS-responsive microglia localize near infiltrating CD4+ T cells. Several microglial chemokines induced in mice are elevated in sera from affected patients. Deletion of GM-CSF in CD4⁺ T cells partially reduces microglial chemokine gene expression, without restoring BBB …

Translational Reading Frame Predicts The Pathogenicity Of C-Terminal Frameshift Deletions In Mecp2, Jacky Guy, Elena Hein, Beatrice Alexander-Howden, Timur Von Bock Und Polach, Tricia Mathieson, Benjamin P Kleinstiver, Huda Y Zoghbi, Adrian Bird

Duncan NRI Faculty and Staff Publications

Mutations in the MECP2 gene cause the severe neurological disorder Rett syndrome. A cluster of frameshift-causing C-terminal deletions (CTDs) removes ~100 amino acids and accounts for approximately 10% of RTT-causing mutations. Their pathogenicity is unexpected because this C-terminal domain is dispensable in mice. Analysis of pathogenic and benign human MECP2 variants reveals that some individuals with apparently typical CTDs do not develop Rett syndrome, confirming that C-terminal truncations are not intrinsically pathogenic. Using human sequence data and mouse models we show that pathogenicity results from a marked reduction in MeCP2 levels and depends on the presence of a proline proline …

Hippo Signaling Regulates Cuticle Pigmentation And Dopamine Metabolism In Drosophila, Shelley B Gibson, Samantha L Deal, Ye-Jin Park, Bo Sun, Yanyan Qi, Jung-Wan Mok, Hyung-Lok Chung, Hongjie Li, Shinya Yamamoto

Duncan NRI Faculty and Staff Publications

Pigmentation plays multiple important roles in development, physiology and evolution. Melanization of the insect cuticle requires dopamine as a precursor of melanin and involves key enzymes in dopamine biosynthesis including Tyrosine hydroxylase (TH) and Dopa decarboxylase (Ddc). Some studies have hinted that disruption of the evolutionarily conserved Hippo signaling pathway, which has been primarily studied in the context of tissue growth, may lead to changes in cuticle pigmentation in the fruit fly Drosophila melanogaster. However, to our knowledge, there have not been any systematic investigations into their potential mechanistic links. In this study, we identified that all genes that comprise …

Hp1bp3 Loss Links Chromatin Reorganization To Metabolic Vulnerability In Glioma, Brittney Lozzi, Taylor A Gatesman, Pushan Dasgupta, Debosmita Sardar, Yeunjung Ko, Chenyu Mao, Hsiao-Chi Chen, Rachel N Curry, Dongjoo Choi, Carrie A Mohila, Melissa L Bondy, Ganesh Rao, Marco Gallo, Sameer Agnihotri, Benjamin Deneen

Duncan NRI Faculty and Staff Publications

High-grade gliomas (HGGs) are aggressive brain tumors with poor prognosis, driven in part by metabolic and epigenetic adaptations. Methionine metabolism supports HGG growth by supplying S-adenosylmethionine for methylation reactions, yet how nutrient availability influences chromatin organization in HGG remains incompletely understood. Using an immunocompetent mouse model of HGG, we found that dietary methionine restriction reduced tumor proliferation, extended survival, and induced partial nuclear inversion. We identified Hp1bp3 as a key regulator of tumor growth that functions by interacting with nuclear tethering proteins to mediate chromatin reorganization. Loss of Hp1bp3 results in the upregulation of histone demethylases leading to selective depletion …

Cd11c+ Cd8 T Cells Cause Ifn-Γ-Dependent Autoimmune Neuroinflammation That Is Restrained By Pd-1 Signaling, Daniel Hwang, Gholamreza Azizi, Larissa Lumi Watanabe Ishikawa, Maryam S. Seyedsadr, Arin Cox, Soohwa Jang, Ezgi Kasimoglu, Abdolmohamad Rostami, Guang-Xian Zhang, Bogoljub Ciric

Department of Neurology Faculty Papers

In multiple sclerosis (MS) lesions, CD8 T cells outnumber CD4 T cells, suggesting that they contribute to MS pathology. However, little is known about the role of CD8 T cells in MS, partly due to the prevalent use of experimental autoimmune encephalomyelitis (EAE) models mediated by CD4 T cells, which have limited involvement of CD8 T cells. Importantly, MS and EAE differ in both their distribution of CNS lesions and neurologic deficits, indicating differences in CNS inflammation. MS lesions are more commonly found in the brain, whereas EAE lesions are more frequent in the spinal cord. Additionally, neurologic deficits in …

Genetic Analysis Of The X-Linked Adrenoleukodystrophy Gene Abcd1 In Drosophila Uncovers A Conserved Phenotype, Joshua Manor, Sharayu V Jangam, Hyung-Lok Chung, Pranjali Bhagwat, Jonathan C Andrews, Hillary Chester, Shu Kondo, Saurabh Srivastav, Juan Botas, Ann B Moser, Suzette M Huguenin, Michael F Wangler

Duncan NRI Faculty and Staff Publications

X-linked adrenoleukodystrophy (X-ALD) is a progressive neurodegenerative disorder caused by a loss-of-function (LOF) mutation in the ATP-binding cassette subfamily D member 1 (ABCD1) gene, leading to the accumulation of very long-chain fatty acids (VLCFAs). This disorder exhibits striking heterogeneity; some male patients develop an early childhood neuroinflammatory demyelination disorder, while other patients, including adult males and most affected female carriers, experience a chronic progressive myelopathy. Adrenocortical failure is observed in almost all male patients, with the age of onset varying, sometimes being the first diagnostic finding. The gene underlying this spectrum of disease encodes an ATP-binding cassette (ABC) transporter that …

Neuropathological Hallmarks During The Chronic Phase Of Ischemic Stroke In Mice And Humans, Romeesa Khan, Gary Guzman, Trang Do, Patrick Devlin, John Ahn, Chunfeng Tan, Venugopal Reddy Venna, Sean P Marrelli, Haniyeh Koochak, Claudia M Di Gesù, Anthony Flores, Louise D Mccullough, Rodney M Ritzel

Faculty, Staff and Student Publications

Background: Advances in acute stroke care, including endovascular thrombectomy and improved neurocritical management, have increased survival after ischemic stroke. However, stroke remains a leading cause of long-term disability, with many survivors experiencing persistent neurological and cognitive impairments. The chronic neurological consequences of stroke, particularly its potential to accelerate brain aging, remain poorly understood.

Methods: We examined chronic neurobehavioral changes at 2 and 6 months after middle cerebral artery occlusion in male C57Bl/6 mice. Behavioral assessments included the open field test (OFT), novel object recognition test (NORT), fear conditioning (FC), nesting activity, and tail suspension testing. Transcriptomic profiling was performed using …

Platelets Cause Microvascular Occlusion And Delayed Neurological Deficits After Subarachnoid Hemorrhage In Mice., Ari Dienel, Sung-Ha Hong, Kiara Torres, Kanako Matsumura, Jose Guzman, Peeyush Thankamani Pandit, Bibek Samal, Harveen Kaur, Samitha Nemirajaiah, Angelica Bernal, H Alex Choi, Louise D Mccullough, Spiros L Blackburn, Jaroslaw Aronowski, Devin W Mcbride

Faculty, Staff and Student Publications

After subarachnoid hemorrhage (SAH), some patients develop delayed neurological deficits (DND). Microthrombi are considered a contributing factor to DND, but clinical trials of antiplatelets had mixed results. Existing research suggests that platelets play a role in the etiology of DND, but no comprehensive study has tested causality between platelets and DND after SAH. Here we hypothesize that after SAH, platelet activation promotes microthrombi formation, occlusion of the brain microvasculature and contributes to DND, and that inhibiting platelet aggregation is a therapeutic strategy. Mice experiencing SAH were administered various interventions. The animals were subjected to stimulation of platelets, platelet depletion, or …

Non-Synaptic Function And Localization Of Syntaxin-Binding Protein 1 In A Mouse Model Of Stxbp1-Related Epileptic Encephalopathy, Tao Yang, Rajat Banerjee, Yamei Deng, Sheetal Jahagirdar, Joo Hyun Kim, Wu Chen, Mingshan Xue, Alexey I Nesvizhskii, Michael D Uhler, Jack M Parent, Yu Wang

Duncan NRI Faculty and Staff Publications

Objective: De novo mutations in the syntaxin-binding protein 1 (STXBP1), encoded by STXBP1, are among the most prevalent causes of variable neurodevelopmental disorders, including epileptic encephalopathy, developmental delay, and movement disorders. Although STXBP1 has been proposed as a critical presynaptic protein controlling synaptic vesicle exocytosis, clinical phenotypes also suggest that its biological function could be more diverse.

Methods: The expression pattern of STXBP1 was studied using immunostaining in vitro and in vivo. Synaptosome isolation was performed to investigate the synaptic and non-synaptic localization of STXBP1 in the brain. STXBP1 immunoprecipitation followed by mass spectrometry (MS) was conducted to identify protein …

Tead-Independent Mechanisms Of Yap Function In Cardiomyocyte Cell Cycle Reentry, Bing Xie, Jeffrey Steimle, Vaibhav Deshmukh, Lin Liu, Chang-Ru Tsai, Todd R Heallen, Wyatt Paltzer, Yuka Morikawa, Fansen Meng, Jun Wang, James F Martin

Faculty, Staff and Students Publications

Adult mammalian hearts exhibit limited regenerative capacity because of the restricted renewal of cardiomyocytes. Recent studies reveal that mammalian hearts exhibit transient regenerative potential within a short time frame after birth, suggesting a regulatory mechanism that prevents adult hearts from initiating a regenerative response to cardiac injury. Here, we discovered that an active form of YAP, named YAP6SA, which is not inhibited by the Hippo signaling pathway and does not interact with TEADs, induces cardiomyocyte cell cycle reentry. In addition, YAP6SA interacts with scaffold protein MPDZ to regulate Rho GTPases and promote cell cycle progression in cardiomyocytes (CMs). Importantly, YAP6SA …

Pathogenesis Of Polyglutamine Diseases: Piecing Together A Complex Molecular Puzzle, Esmeralda Villavicencio Gonzalez, Huda Y Zoghbi

Duncan NRI Faculty and Staff Publications

Polyglutamine (polyQ) diseases, caused by a CAG repeat expansion encoding a glutamine tract in nine distinct proteins, present a complex molecular puzzle in which each piece contributes to neurodegeneration. While each of the causative proteins has a distinct function, the downstream consequences of polyQ toxicity are often similar, including protein accumulation, transcriptional dysregulation, somatic CAG repeat instability, disrupted energy homeostasis, compromised synaptic function, and selective neuronal death. This review summarizes emerging insights into how proteins with an expanded polyQ tract disrupt distinct cellular functions, and we examine a multitude of discoveries that are inspiring and reshaping novel therapeutic strategies.

Discovery Of Small Molecules And A Druggable Groove That Regulate Dna Binding And Release Of The Ap-1 Transcription Factor Δfosb, Sean Mcneme, Yun Young Yim, Ashwani Kumar, Yi Li, Brandon Hughes, Corey Peyton St Romain, Galina Aglyamova, Jianping Chen, Nghi D Nguyen, Shanghua Fan, Gabriel S Stephens, Wen-Ning Zhao, Samantha Kruzshak, Molly Estill, Corrine Brener, Solange Tofani, Anil Kumar, Earnest P Chen, Nadeen Takatka, Alfred J Robison, Haiying Chen, Reid T Powell, Stephen J Haggarty, Clifford Stephan, Eric J Nestler, Jeannie Chin, Mischa Machius, Jia Zhou, Gabby Rudenko

Faculty, Staff and Students Publications

ΔFOSB, a member of the AP-1 family of transcription factors, mediates long-term neuroadaptations underlying drug addiction, seizure-related cognitive decline, dyskinesias, and several other chronic conditions. AP-1 transcription factors are notoriously difficult to modulate pharmacologically due to the absence of well-defined binding pockets. Here, we identify a novel site on ΔFOSB, located outside the DNA-binding cleft, that accommodates small molecules. We show that sulfonic acid-containing compounds bind to this site via an induced-fit mechanism, reorienting side chains critical for DNA binding, and that they may hinder the ΔFOSB bZIP α-helix from binding to the major groove of DNA. In vivo, direct …

Metabolomic Profiling Reveals Brain Lipid Alterations In Pex7-Deficient Models Of Rhizomelic Chondrodysplasia Punctata, Riya Sankhe, Meredith I Williams, Wedad Fallatah, Laura Mackay, Mary Layne Brown, Pranjali Bhagwat, Sarah H Elsea, Nancy Braverman, Michael F Wangler

Duncan NRI Faculty and Staff Publications

Rhizomelic chondrodysplasia punctata type 1 (RCDP1) is a peroxisomal disorder characterized by skeletal shortening, intellectual disability, seizures, cataracts, and reduced lifespans. RCDP1 is caused by biallelic loss-of-function variants in PEX7, which encodes a protein required for importing select enzymes into the peroxisome matrix, including those essential for ether lipid synthesis (e.g., plasmalogens) and the branched-chain fatty acid catabolism. Plasmalogen deficiency is a hallmark of RCDP1 and other peroxisomal disorders, including RCDP types 2-5 (RCDP2-5) and Zellweger spectrum disorders (ZSD). Here, we performed comprehensive metabolomic profiling of clinical samples from RCDP patients and Pex7-deficient mouse models. We identified profound …

A Distinct Pp2a Subunit Regulates Local Protein Phosphorylation At The Axon Initial Segment, Andrew P Anderson, Sanghyun Kim, Allison J Melton, Xiaoyun Ding, Wei Zhang, Alexander B Saltzman, Anna Malovannaya, Matthew N Rasband, Yudong Gao

Faculty, Staff and Students Publications

Protein phosphorylation plays a crucial role in regulating the cytoskeletal and membrane proteins at the axon initial segment (AIS). However, our knowledge of AIS-specific kinases and phosphatases is very limited. Here, we report the identification of a protein phosphatase 2A (PP2A) B55 regulatory subunit enriched at the AIS in mice: Ppp2r2c. Our results demonstrate that PP2A-B55 subunits exhibit substantial heterogeneity in their subcellular localization and function. Notably, the Ppp2r2c subunit is selectively concentrated at the AIS, and this enrichment is driven by its unique structure. Utilizing a microelectrode array system (MEA), we show that Ppp2r2c modulates neuronal activity during in …

Loss Of The Lysosomal Protein Cln3 Triggers C-Abl-Dependent Yap1 Pro-Apoptotic Signaling, Neuza Domingues, Alessia Calcagni', Sofia Freire, Joana Pires, Ricardo Casqueiro, Ivan L Salazar, Niculin Joachim Herz, Tuong Huynh, Katarzyna Wieciorek, Tiago Fleming Outeiro, Henrique Girão, Ira Milosevic, Andrea Ballabio, Nuno Raimundo

Duncan NRI Faculty and Staff Publications

Batten disease is characterized by early-onset blindness, juvenile dementia and death within the second decade of life. The most common genetic cause are mutations in CLN3, encoding a lysosomal protein. Currently, no therapies targeting disease progression are available, largely because its molecular mechanisms remain poorly understood. To understand how CLN3 loss affects cellular signaling, we generated human CLN3 knock-out cells (CLN3-KO) and performed RNA-seq analysis. Our multi-dimensional analysis reveals the transcriptional regulator YAP1 as a key factor in remodeling the transcriptome in CLN3-KO cells. YAP1-mediated pro-apoptotic signaling is also increased as a consequence of CLN3 functional loss in retinal pigment …

Cross-Species Standardised Cortico-Subcortical Tractography, Stephania Assimopoulos, Shaun Warrington, Davide Folloni, Katherine Bryant, Ali-Reza Mohammadi-Nejad, Wei Tang, Saad Jbabdi, Sarah R Heilbronner, Rogier B Mars, Stamatios N Sotiropoulos

Faculty, Staff and Students Publications

Despite their importance for brain function, cortico-subcortical white matter tracts are under-represented in diffusion magnetic resonance imaging tractography studies. Their non-invasive mapping is more challenging and less explored compared to other major cortico-cortical bundles. We introduce a set of standardised tractography protocols for delineating tracts between the cortex and various deep subcortical structures, including the caudate, putamen, amygdala, thalamus, and hippocampus. To enable comparative studies, our protocols are designed for both human and macaque brains. We demonstrate how tractography reconstructions follow topographical principles obtained from tracers in the macaque and how these translate to humans. We show that the proposed …

From Bladder To Brain: How You Know When It’S Time To Go, Anne M J Verstegen, Kara L Marshall

Duncan NRI Faculty and Staff Publications

The decision to urinate relies on assessing bladder fullness and context to determine an appropriate time and place to go. Any disruption in this interoceptive process results in frequent and sometimes debilitating consequences in daily life. Recent work has uncovered key pathways and brain regions that contribute to the sense of bladder stretch and the control of urinary reflexes, but many open questions remain. Here, we review the known mechanisms that convey sensory information from the bladder to the brain and back down again, and we highlight the knowledge gaps and opportunities for better understanding this system, which will be …

Multisite Assembly Of Gateway Induced Clones (Magic): A Flexible Cloning Toolbox For Use In Vertebrate Model Systems, William B Gillespie, Yuwen Zhang, Oscar E Ruiz, Juan Cerda, Joshua Ortiz-Guzman, Michelle Sherman, Williamson D Turner, Gabrielle Largoza, Lili E Mosser, Esther Fujimoto, Chi-Bin Chien, Kristen M Kwan, Benjamin R Arenkiel, W Patrick Devine, Joshua D Wythe

Duncan NRI Faculty and Staff Publications

Here, we present MultiSite Assembly of Gateway Induced Clones (MAGIC), which leverages Gateway-based recombinatorial cloning technology for rapid, modular assembly of plasmids to facilitate transgenesis in cells and vertebrate animal models. The MAGIC collection of plasmids spans a range of in vitro and in vivo uses, from tools for optically and chemically tunable gene expression, to simultaneous expression of microRNAs and fluorescent reporters, to a suite of distinct subcellular compartmental fluorescent reporters, to Cre and Dre recombinase-dependent gene expression. MAGIC system components are compatible with existing MultiSite Gateway Tol2 systems currently used in zebrafish and mammalian lentiviral and adenoviral Destination …

Sensory-Selective Peripheral And Neuraxial Nerve Blockade With 2',6'-Pipecoloxylidide, Claire A Ostertag-Hill, Shuanglong Chen, Tianrui Xue, Rachelle Shao, Matthew Torre, Bin Feng, Zahra Vahedi, Longtu Chen, Steven J Staffa, Yueqin Zheng, Daniel S Kohane

Duncan NRI Faculty and Staff Publications

Background: Safe sensory-selective local anesthetics would be a major advance in the management of acute and chronic pain. This articles describes the sensory-selective local anesthetic properties and the toxicity profile of a known metabolite of amino-amide local anesthetics, 2',6'-pipecoloxylidide (PPX).

Methods: PPX was synthesized and made into its hydrochloride salt. PPX or ropivacaine (ROP) were injected at the sciatic nerve or intrathecally in rats, who then underwent modified hotplate (sensory) testing and weight-bearing (motor) testing. Rats injected with PPX or ROP were assessed for clinical toxicity endpoints. Conduction blockade was studied with single-unit recordings in mice. Biocompatibility was assessed histologically. …

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 …

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 …

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 …

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 …