Medical Sciences Commons^™

Steroid Receptor Coactivator 3-Deficient Regulatory T Cells Eradicate Multiple Solid Tumors In Syngeneic Mouse Models, Nuri Sung, Eunsu Kim, Yosef Gilad, Yuri Park, Adam M Dean, Yan Xia, Jianming Xu, Clifford C Dacso, David M Lonard, Sang Jun Han

Faculty, Staff and Students Publications

Steroid receptor coactivator 3 (SRC-3) is highly expressed in regulatory T cells (Tregs) and is important for their immunosuppressive activity. Recently, we demonstrated that disrupting SRC-3 expression in Tregs eliminates triple-negative breast cancer (TNBC) and prostate cancer in syngeneic animal models by generating an anti-tumor immune microenvironment without inducing immune-related adverse events (irAEs). Further analysis of these mice revealed that SRC-3 knockout (KO) Tregs infiltrated breast tumors and facilitated the infiltration of CD8

Mtorc2-Nav1.2 Signaling Drives Early Hyperexcitability In Alzheimer’S Disease Mouse Model, Nolan M Dvorak, Jeffrey L Noebels

Faculty, Staff and Students Publications

Hyperexcitability is a biomarker of early-stage Alzheimer’s Disease (AD) and hastens cognitive decline later in its course. Mechanistic target of rapamycin (mTOR) signaling contributes to the slope of this trajectory, as evidenced by early increased brain expression and the rescue of hyperexcitability by genetic deletion of mTOR complex 2 (mTORC2); however, a molecular mechanism directly linking mTOR signaling to membrane hyperexcitability in early-stage AD remains elusive. Here, we show that hyperactive mTOR signaling stimulates the voltage-gated Na+ channel 1.2 (Nav1.2), a previously identified downstream phosphorylation target of mTORC2 and a key regulator of membrane electrogenesis. Augmented Nav1.2 channel function induced …

Cells And Networks In Flux: Rethinking Ontogenesis And Pathogenesis, Mark L. Tykocinski

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Organ and tissue functions emerge from the coordinated activity of cell networks. Therapeutics that act on pathogenic cell networks, modulating their cellular interplay, follow naturally. Over several decades, our laboratory has developed a series of approaches for rewiring cell networks, culminating in a class of cell surface-directed signal converter proteins (SCPs) that do so by modulating juxtacrine and autocrine signaling in and among their nodal cells. A first such SCP has now produced encouraging clinical data for cancer immunotherapy. Yet, these early network-directed fusion proteins rest on a deliberately simplified picture: discrete end-cell types plugged into graphically tractable networks. That …

Telomere-To-Telomere Genome Assembly And A Pangenome For The Rat, Kai Li, Julia L Ciosek, Sergey Koren, Adam M Phillippy, Yaming Zhu, William A Lauer, Shelise Y Brooks, Gerard G Bouffard, Brandon D Pickett, Beth L Dumont, Melissa L Smith, Theodore S Kalbfleisch, Peter A Doris

The Brown Foundation: Institute of Molecular Medicine

We report a complete rodent telomere-to-telomere genome assembly from the brown rat, Rattus norvegicus. Annotation was enriched with multi-tissue long-read RNA sequencing and uncovered numerous novel genes. Assembly of both sex chromosomes reveals the absence of gene coding in the presumed pseudo-autosomal regions and the presence of centromeric satellite repeats on distal chromosome Y (chrY). We provide evidence of meiotic conjunction between Xp and Yq. The genome assembly reveals several expanded autosomal regions enriched for testis-expressed genes. Finally, we have generated a pangenome from recent high-quality assemblies of 8 distinct inbred rat strain genomes. This allows the strain-specific distribution of …

Cigarette Smoke Induces Fasn-Dependent Fatty Acid Metabolic Rewiring To Drive Bladder Cancer Progression, Chandra Sekhar Amara, Danthasinghe Waduge Badrajee Piyarathna, Abu Hena Mostafa Kamal, Yuen San Chan, Karthik Reddy Kami Reddy, Chandra Shekar R Ambati, Mohammed Khurshidul Hassan, Pratik Shriwas, Tanmay Gandhi, Antrix Jain, Tanja Gangnus, Pooja Popli, Roshan Borkar, Sung Wook Kang, Silvia L Summers, Vasanta Putluri, Sandra L Grimm, Sharan Venkatesh, Ningxin Song, Erin H Seeley, Jenna Hedlich-Dwyer, Shu-Hsia Chen, Nupam P Mahajan, Abhinav K Jain, Lacey Elizabeth Dobrolecki, Gabrielle A Wells, Hugo Villanueva, Jenny Li, Xuefeng Liu, Roni J Bollag, Anna Malovannaya, Sung Yun Jung, Hyun-Sung Lee, Irfan A Asangani, Martha K Terris, Chad J Creighton, Leomar Y Ballester, Balasubramanyam Karanam, Suyu Liu, Minjae Lee, Rajeeva R Raju, M Minhaj Siddiqui, Livia S Eberlin, Ramakrishna Kommagani, Arun Sreekumar, Jianjun Gao, Nicolas L Young, H Courtney Hodges, Cristian Coarfa, Natalie R Gassman, Seth P Lerner, Yair Lotan, Nagireddy Putluri

Faculty, Staff and Students Publications

Cigarette smoke promotes bladder tumor growth by enhancing cancer cell survival and proliferation through smoke mediated carcinogens. FASN, a key enzyme in fatty acid synthesis, is dysregulated in many cancers and correlates with aggressive phenotypes. In this study, we demonstrate elevated fatty acid levels and FASN specifically in smokers with bladder cancer. Elevated FASN under smoke exposure imparted epigenetic alterations, particularly histone acetylation, impacts DNA repair and DNA-binding transcription factors which regulate metabolic pathways. Under cigarette smoke, bladder cancer cells undergo a metabolic shift, utilizing glutamine as a major carbon source through reductive carboxylation to fuel fatty acid biosynthesis via …

Notch Signaling Regulates The Secretion Of Pro-Metastatic Factors In Extracellular Vesicles In Liposarcoma, Menchus Quan, Yi-Kai Liu, Ying Zhao, Madeline Kay, Kai Sun, Timothy P Gavin, Raphael E Pollock, W Andy Tao, Shihuan Kuang

The Brown Foundation: Institute of Molecular Medicine

Notch signaling is an emerging regulator of liposarcoma (LPS), but its role in mediating communication with the tumor microenvironment (TME) is unclear. Here, we investigate how Notch activation (NICD overexpression) alters the proteomes of LPS-derived extracellular vesicles (EVs). We used quantitative mass spectrometry to profile the EV proteome in multiple contexts: cultured LPS cells, LPS tumor, circulating EVs of LPS-bearing mice, and human LPS samples. We found that Notch signaling increases the secretion of EV proteins that favor tumor progression and metastasis but suppresses immune responses in murine LPS cells. Overlapping murine and human LPS data identifies 18 proteins that …

Myeloid Mmp14 Couples Extracellular Proteolysis To Inflammatory And Metabolic Remodeling During Obesity, Long J Shao, Fathima Elizondo, Feng Gao, Elizabeth L Lieu, Bharati Reddi, Maryam Elizondo, Iqbal Mahmud, Kristin Eckel-Mahan, Philipp E Scherer, Xin Ge, Huaizhu Wu, Sean Hartig, Kai Sun

The Brown Foundation: Institute of Molecular Medicine

Macrophages orchestrate tissue remodeling, inflammation, and metabolic dysfunction in obesity, but the role of macrophage-intrinsic extracellular proteolysis in immunometabolic regulation remains unclear. Matrix metalloproteinase-14 (MMP14), a membrane-bound protease, is strongly induced during monocyte-to-macrophage differentiation and further elevated in adipose tissue macrophages from high-fat diet (HFD)-fed mice. Pharmacological inhibition or myeloid-specific deletion of Mmp14 impaired macrophage differentiation, proliferation, migration, phagocytosis, and inflammatory activation in response to obesity-associated adipose tissue signals. Mechanistically, MMP14 promoted inflammatory programming by increasing endotrophin generation and enhancing TLR4-NFκB signaling. MMP14 also reprogrammed macrophage lipid metabolism by suppressing lipolysis and promoting lipid accumulation, altering metabolic communication with neighboring …

Unbiased Avidity-Based Isolation Of Antigen-Specific T Cells, Amanda Montoya, Meredith L Frank, Peixin Jiang, Hui Nie, Minying Zhang, Emily Bontekoe, Jared K Slone, Ludovica L Posta, Sofia Rosy Caterina Sorice, Tina Cascone, Maura Gillison, Don L Gibbons, Jianjun Zhang, Eleonora Dondossola, Lydia Kavraki, Pamela L Wenzel, John V Heymach, Alexandre Reuben

The Brown Foundation: Institute of Molecular Medicine

Background: Cancer immunotherapies have significantly improved treatment efficacy and patient survival by exploiting antigen-specific T cells to eliminate cancer cells. However, current approaches for identifying and isolating antigen-specific T cells typically require prior knowledge of target antigens, limiting discovery, and reducing the ability to consistently detect rare tumor-reactive T cells. We therefore sought to develop an unbiased platform for the identification and enrichment of antigen-specific T cells using naturally processed and presented tumor antigens.

Methods: We developed ATTACH (Assessment of T cells Tethered to Antigen Class I Histocompatibility), a microfluidic platform that applies controlled shear stress and leverages tumor cells …

Tau Pathology In Epilepsy: Emerging Mechanisms And Translational Opportunities, Arjune Sen, Xin You Tai, Aristea Galanopoulou, Maria Thom, Eleonora Aronica, Lucy Vivash, Martin Hardmeier, Action Amos, Stephan Rueegg, Matthias Koepp, Yaroslav Winter, Christoph Helmstaedter, Jeffrey L Noebels, Hilal A Lashuel, Terence J O'Brien

Faculty, Staff and Students Publications

The onset of epilepsy in adulthood occurs most commonly after 55 years of age. Given the ageing global population, this disorder represents an increasing burden on healthcare and society. The bidirectional link between epilepsy and dementia is a focus of intense research with underlying tau pathology highlighted as a potential mechanistic link. In this review, we examine the evidence for tau-related neurodegenerative processes in epilepsy beginning with how changes in biochemical and structural properties of the tau protein can lead to abnormal phosphorylation and pathological aggregation. We consider the role of tau in seizure occurrence and cognitive difficulties in experimental …

Bi-Allelic Loss-Of-Function Variants In Tmem63b Cause Syndromic Surfactant Dysfunction Disorder, Sock Hoai Chan, Audra N Iness, Jill A Rosenfeld, Mir Reza Bekheirnia, Lindsay C Burrage, Matthew Hoi Kin Chau, Chaerish Eint Myet Chae Htoo, Eric C Kao, Shamika Ketkar, Wan Wan Lim, Xi Luo, Rifhan Mazlan, Elizabeth Mizerik, Kein Seong Mun, Kalyani R Patel, Lorraine Potocki, Christina K Rapp, Xavier Roca, Ana Saianda, Ignacio Iglesias-Serrano, Everlyn C Siew, Donald Yuhui Sim, David R Spielberg, Sok-Kun Tae, Jing Xian Teo, Julian Warfsmann, Fan Xia, Child-Eu Registry, Saumya S Jamuar, Ee Shien Tan, Matthias Griese, Weng Khong Lim, Meow-Keong Thong, Keren Machol

Faculty, Staff and Students Publications

Transmembrane protein 63B gene (TMEM63B) encodes a mechanosensitive ion channel expressed in alveolar type II epithelial cells, where it mediates stretch-induced surfactant secretion. While heterozygous gain-of-function variants in TMEM63B have been associated with developmental and epileptic encephalopathy, no human disorder has previously been linked to bi-allelic loss-of-function variants. Here, we report five individuals from four unrelated families with childhood interstitial lung disease and bi-allelic predicted loss-of-function variants in TMEM63B. Affected individuals presented with early-onset respiratory distress, chronic hypoxemia, and diffuse parenchymal lung abnormalities on chest imaging. One individual died in infancy, two underwent bilateral lung transplantation, and two require oxygen …

Na-Gst-1 Adsorbed On Alhydrogel Co-Administered With Different Toll-Like Receptor Agonists In Hookworm-Naive Adults Using A Controlled Human Infection Model In The Usa: A Phase 2, Double-Blind, Randomised Controlled Trial, Caroline K Dirosato, Elissa M Malkin, Sean M Lee, Guacyara Erwin, Lara Hoeweler, Larissa Scholte, Maria Elena Bottazzi, David I Pritchard, Peter J Hotez, Jeffrey M Bethony, David J Diemert

Faculty, Staff and Students Publications

Background: Necator americanus glutathione S-transferase-1 (Na-GST-1) performs a crucial enzymatic step in hookworm blood feeding and is a leading target for vaccine development. Phase 1 trials in Brazil, Gabon, and the USA of recombinant Na-GST-1 adsorbed on Alhydrogel (Na-GST-1/Al), co-administered with or without AP 10-701 (Toll-like receptor [TLR] 4 agonist) or CpG 10104 (TLR9 agonist), showed the vaccine was well tolerated, safe, and immunogenic. A controlled human hookworm infection (CHHI) model was previously developed to evaluate the effect of candidate hookworm vaccines on infection. We aimed to assess the effect of vaccination with three different Na-GST-1 vaccine formulations on subsequent …

Helminth-Infected Mozambican Children With Malaria Have Increased Anaemia, Cytokines And Helminth-Specific Antibodies, Inocência Cuamba, Rebeca Santano, Berta Grau-Pujol, Marta Vidal, Anélsio Cossa, Chenjerai Jairoce, Rojelio Mejía, José Muñoz, Ruth Aguilar, Bin Zhan, Augusto Nhabomba, Gemma Moncunill, Carlota Dobaño

Faculty, Staff and Students Publications

Owing to their overlapping geographical distribution and the consequent occurrence of coinfections, several studies have evaluated the impact of helminth infections on malaria immune responses and clinical outcomes. However, little has been reported on how malaria coinfection affects anthelmintic responses in children harbouring worm infections. We therefore aimed to assess the impact of malaria coinfection on helminth-related clinical and immune outcomes in children. Here, we measured in plasma the levels of 30 cytokines, total IgE, and helminth-specific IgM, IgA, IgG, IgG1-4, and IgE antibodies to a panel of 11 helminth antigens by Luminex. Samples were obtained from 441 children aged …

Statistics Of Natural Scenes Shape Contextual Modulation In The Visual Cortex, Jiakun Fu, Suhas Shrinivasan, Luca Baroni, Zhuokun Ding, Paul G Fahey, Paweł A Pierzchlewicz, Nikos Karantzas, Kayla Ponder, Rachel Froebe, Lydia Ntanavara, Taliah Muhammad, Konstantin F Willeke, Eric Wang, Zhiwei Ding, Dat Tran, Stelios Papadopoulos, Saumil Patel, Jacob Reimer, Alexander S Ecker, Xaq Pitkow, Jan Antolik, Fabian H Sinz, Ralf M Haefner, Andreas S Tolias, Katrin Franke

Faculty, Staff and Students Publications

Vision is context dependent, with neuronal responses shaped not only by local features but also by surrounding visual input. While classical studies, using grating stimuli, show that iso-oriented surrounds suppress responses more than orthogonal surrounds, the role of contextual modulation under natural stimulus conditions remains less clear. Using recordings from mouse primary visual cortex (V1), we trained convolutional neural network models to predict neuronal responses to natural images and synthesized surround stimuli that selectively suppressed or facilitated responses to optimal center inputs. In vivo experiments confirmed these predictions. Facilitatory surrounds resembled naturalistic continuations of the optimal center stimulus, consistent with …

Mechanisms Coordinating Exit From The Stem Cell State In Mammals, Emily J Park, Florencia Levin-Ferreyra, Bruno Di Stefano

Faculty, Staff and Students Publications

Differentiation requires coordinated exit from the stem cell state, during which gene regulatory networks sustaining self-renewal are dismantled, while lineage-specific programs are activated. This transition is governed by chromatin modifications, transcriptional networks, RNA processing, translational control, and metabolic rewiring that must operate with temporal precision. Despite significant progress in identifying individual regulatory components, understanding how these layers integrate to orchestrate irreversible cell fate commitment remains a fundamental challenge. This review examines common and unique regulatory principles governing stem cell exit, from totipotency during early embryogenesis to tissue-specific stem cell differentiation in adults. We synthesize recent findings on regulatory mechanisms across …

Nano-Bio Interfacial Effects Modulating Protein Adsorption In Dialdehyde Lentinan-Crosslinked Polysaccharide Sponges Reinforced With Zein Nanoflowers, Dorota Chelminiak-Dudkiewicz, Miloslav Machacek, Hana Janová, Klara Konecna, Ondrej Jandourek, Jana Kejmarová, Kinga Mylkie, Aleksander Smolarkiewicz-Wyczachowski, Marta Ziegler-Borowska

The Brown Foundation: Institute of Molecular Medicine

The interfacial organization of porous biomaterials critically influences protein adsorption and subsequent cell-material interactions at hydrated biointerfaces relevant to wound-contacting environments. Herein, hybrid sponges were developed by rationally assembling chitosan, lentinan, levan, and fucoidan into a covalently defined macromolecular network featuring nano-bio interfacial effects. The materials were designed to modulate interfacial biological performance via engineered pore-wall structures, with protein-layer formation at sponge interfaces associated with downstream cell-material responses. A dialdehyde lentinan was deliberately employed to establish a chemically defined pore-wall interface via dense Schiff-base junctions with chitosan. The incorporation of zein nanoflowers introduced additional nanoscale structure features, providing additional anchoring …

Functional Characterization Of Uhrf1 Variants In Facilitating Dna Methylation, Bigang Liu, Kaila Nayvelt, Swanand Hardikar, Kimie Kondo, Marcos R Estecio, Xiaodong Cheng, Taiping Chen

The Brown Foundation: Institute of Molecular Medicine

Ubiquitin-like with plant homeodomain (PHD) and really interesting new gene (RING) finger domains 1 (UHRF1) is essential for DNA methylation inheritance. However, the functional impacts of several natural and engineered UHRF1 variants are either insufficiently characterized or obscured by conflicting results, with some discrepancies likely stemming from cellular toxicity and adaptive responses induced by DNA methylation changes. In this study, we utilized mouse embryonic stem cells (mESCs)-which uniquely tolerate the complete loss of DNA methylation-to evaluate the functional consequences of clinical mutations, isoform variation, and epitope tagging. Using rescue experiments in Uhrf1-deficient mESCs, we characterized two UHRF1 mutations identified in …

Chemotherapeutic Induction Of Cytosolic Single-Stranded Dna Accumulation Sensitizes Triple-Negative Breast Cancer To Immunotherapy, Yong Du, Li Yang, Hui Dai, Jianli Zhou, Zhicheng Zhou, Ruoxi Yuan, Rui Ye, Anh Thai Quynh Nguyen, Kishor Bhatia, Shiaw-Yih Lin

Faculty, Staff and Students Publications

Background: Despite the widespread adoption of chemoimmunotherapy in triple-negative breast cancer (TNBC), the mechanisms by which cytotoxic chemotherapy engages antitumor immunity remain poorly defined. Identifying tumor-intrinsic immunogenic programs that predict and enhance responsiveness to immune checkpoint blockade (ICB) is therefore of critical clinical importance.

Methods: Transcriptomic signatures of TREX1 deficiency were generated from CRISPR-engineered TNBC models and applied to multiple independent TNBC cohorts treated with chemoimmunotherapy. Cytosolic single-stranded DNA (ssDNA) accumulation was quantified using a flow cytometry-based assay to functionally screen chemotherapeutic agents. Immune activation and therapeutic efficacy were evaluated using in vitro assays, syngeneic mouse tumor models, flow cytometry, …

Microglial Swell1 Deficiency Drives Male-Specific Seizure Vulnerability But Paradoxical Neuroprotection Through Impaired Phagocytosis, Abhijeet S Barath, Aastha Dheer, Laura Montier, Mekenzie M Peshoff, Emily Dale, Flavia Goche, Thanh Thanh Le Nguyen, Mastura Akter, Fangfang Qi, Dimitrios Kleidonas, Lauren Harris, Sarah A Jewanee, Anthony D Umpierre, Dale B Bosco, Koichiro Haruwaka, Rajan Sah, Long-Jun Wu, Rongzhuo Hua, Tejaswani Datla

The Brown Foundation: Institute of Molecular Medicine

The discovery of genes encoding the volume-regulated anion channel (VRAC) has enabled detailed exploration of its cell type-specific roles in the brain. LRRC8A (SWELL1) is the essential VRAC subunit. We observed seizure-induced, subunit-specific changes in microglial VRAC expression and investigated its function using conditional KO (cKO) of LRRC8A in microglia. SWELL1 cKO mice exhibited a male-specific increase in kainate-induced seizure severity, yet showed paradoxical neuroprotection against seizure-associated neuronal loss. Mechanistically, SWELL1 deletion led to a cell-autonomous reduction in microglial density and decreased release of VRAC-permeable neuroactive metabolites, including taurine, GABA, and glutamate in culture. Additionally, impaired phagocytic kinetics and reduced …

Neddylation Maintains Oocyte Quality By Stabilizing Mitochondrial Transcription, Avery A Ahmed, Tessa E Steenwinkel, Bethany K Patton, Peixin Jiang, Matthew D Meyer, Jaspreet K Rishi, Mei Leng, Alexander B Saltzman, Elizabeth S Anaya, Momal Sharif, Laurie J Mckenzie, Laura Detti, Anna Malovannaya, Sean M Hartig, Stephanie A Pangas

Faculty, Staff and Students Publications

Age-related decline in oocyte quality increases the risk of infertility, miscarriage, and birth defects. Mitochondrial dysfunction is a key contributor to this decline. Here, we report that oocyte-specific deletion of Uba3, which encodes the catalytic subunit of the E1 NEDDylation-activating complex, causes sterility in mice. Fully grown, germinal vesicle–stage Uba3 conditional knockout oocytes exhibit mitochondrial dysfunction, including elevated reactive oxygen species, impaired oxidative phosphorylation, and depletion of mitochondrially encoded RNA transcripts. Proteomic analysis identified alterations in mitochondrial-associated proteins, including enrichment of mitochondrial matrix and respiratory chain components and reduced abundance of electron transport chain complexes. These defects were associated …

Autophagic Flux Blockade Under Hypocapnia Reveals Co2-Sensitive Regulation Of Autophagy-Lysosome Homeostasis, Naghmana Ashraf, Zhen Sun, Jeanine L Van Nostrand

Faculty, Staff and Students Publications

Hypocapnia, a reduction in partial pressure of carbon dioxide (CO2), commonly occurs in clinical contexts such as mechanical ventilation, panic disorder, and brain injury, yet its impact on cellular homeostasis remains poorly understood. Given the central role of autophagy in stress adaptation, we investigated how low CO2 influences autophagic flux and lysosomal function. We found that hypocapnia induces autophagosome accumulation while impairing cargo degradation, indicating a blockade in autophagic flux. This response was accompanied by increased lysosome biogenesis but, paradoxically, reduced autophagosome-lysosome fusion and lysosomal proteolytic activity. Mechanistically, hypocapnia promoted TFE3 dephosphorylation and nuclear translocation, driving transcriptional activation of lysosomal …

Macropinocytosis Inhibition Attenuates Profibrotic Responses In Lung Fibroblasts And Pulmonary Fibrosis Models, Ivan O Rosas, Aaron K Mcdowell-Sanchez, Santiago Sanchez, Juan D Cala-Garcia, Alan R Waich Cohen, Elisa Ruiz-Echartea, Scott A Ochsner, Daniel C Kraushaar, Lindsay J Celada, Dandan Sun, Francesca Polverino, Cristian Coarfa, Neil J Mckenna, Konstantin Tsoyi

Faculty, Staff and Students Publications

Idiopathic pulmonary fibrosis (IPF) is a devastating chronic lung disorder with limited treatment options. Macropinocytosis is one of the key cellular processes involved in nutrient consumption from the extracellular environment under stress conditions. Here, we studied the role of macropinocytosis in experimental pulmonary fibrosis models. We found that macropinocytosis is increased in human lung fibroblasts (HLFs) derived from patients with IPF. The inhibition of macropinocytosis with 5-(n-ethyl-n-isopropyl)-amiloride (EIPA) inhibited profibrotic responses in IPF-derived and TGF-β1-stimulated HLFs and reduced pulmonary fibrosis in bleomycin-injured (Bleo-injured) mice. EIPA exerted its antifibrotic effects by regulating amino acid uptake, mammalian target of rapamycin complex 1 …

Single-Nucleus Profiling Reveals A Core Disease Signature And Cell Type-Specific Vulnerabilities In Early Rett Syndrome, Yan Li, Ashley G Anderson, Guantong Qi, Sih-Rong Wu, Jean-Pierre Revelli, Hu Chen, Zhandong Liu, Huda Y Zoghbi

Faculty, Staff and Students Publications

Rett syndrome (RTT) is an X-linked neurological disorder caused by MECP2 mutations, creating distinct cellular environments in females (mosaic) versus males (nonmosaic). Despite female patients representing most cases, how mosaicism contributes molecularly to RTT pathogenesis, particularly in presymptomatic stages, remains poorly understood. To address this question, we profiled hippocampal transcriptomes of young female and male RTT mice using bulk and single-nucleus RNA sequencing. We identified a core disease signature of consistently dysregulated genes only in MeCP2− cells across RTT models. Moreover, we uncovered non–cell autonomous effects exclusively in female MeCP2+ excitatory neurons, suggesting that these circuits are more vulnerable early …

In Vivo Orf Overexpression Screening Identifies Ccn4 As A Regulator Of Glioblastoma Growth Validated Across Multiple Models, Pushan Dasgupta

Faculty, Staff and Students Publications

Despite current multimodal therapies for glioblastoma (GBM), its prognosis remains grim. Thus, a tremendous need exists to identify new genetic drivers that may serve as potential therapeutic targets in glioblastoma (GBM). We describe an in vivo overexpression screening strategy to identify drivers of glioblastoma where we have leveraged TCGA datasets to conduct a functional genomics screen of prioritized open reading frames (ORFs) that are overexpressed and/or amplified in GBM. To interrogate these potential drivers within a more relevant physiological context, the screening was accomplished in vivo in an orthotopic patient-derived glioma stem-like cell (GSC) model. Among 5 positive "hits" from …

Notch1 Acts As A Tumor Suppressor That Induces Early Differentiation In Head And Neck Cancer, Chenfei Huang, Shhyam Moorthy, Qiuli Li, Kazi M Ahmed, Kalil Saab, Defeng Deng, Jiping Wang, Xiayu Rao, Jiexin Zhang, Yuanxin Xi, Jing Wang, Zhiyi Liu, Noriaki Tanaka, David A Wheeler, Eve Shinbrot, Rami Saade, Curtis R Pickering, Tong-Xin Xie, Adel K El-Naggar, Abdullah A Osman, Kunal Rai, Patrick A Zweidler-Mckay, John V Heymach, Lauren A Byers, Faye M Johnson, Vlad C Sandulache, Jeffrey N Myers, Pedram Yadollahi, Mitchell J Frederick

Faculty, Staff and Students Publications

Inactivating NOTCH1 mutations in head and neck squamous cell carcinoma (HNSCC) were described over a decade ago, suggesting a tumor suppressor function - unlike its oncogenic role in other tumors. Today, much debate persists regarding a putative oncogenic role in HNSCC as well, with reports that NOTCH1 signaling drives tumor growth and a cancer stem cell (CSC) phenotype. In this work, comprehensive experiments unequivocally demonstrate that NOTCH1 is a tumor suppressor in HNSCC regardless of mutation or activation status and that it reduces CSC frequency. We developed a signature of NOTCH1 activation showing the pathway is associated with very early …

Histone Deacetylase Enzyme Activity Is Not The Universal Anticancer Target Of Hdac Inhibitors, Chaitra Rai, Hang Ruan, Xue Li, Wenbo Li, Hyun-Hwan Jeong, Chengchuang Song, Panpan Liu, Yingjie Chang, Hao Fang, Udhaya Kumar S, Yuxiang Sun, M James You, Dongyin Guan, Zhandong Liu, Leng Han, Xuben Hou, Zheng Sun

Faculty, Staff and Students Publications

Histone deacetylase inhibitors (HDIs) are approved for treating hematologic cancers and are currently being evaluated in hundreds of clinical trials for various cancers and other diseases, although their mechanisms of action remain poorly understood. Here, our unbiased bioinformatics analyses found that, for most cancer types, expression levels or genetic variants of histone deacetylase (HDACs) do not consistently correlate with carcinogenesis, do not predict cancer patient survival, and do not associate with cellular responses to HDIs. Whole-genome CRISPR library screens did not identify HDACs as genes affecting cellular responses to HDIs. Overexpression of dominant-negative Class I HDACs causes similar protein hyperacetylation …

Monoclonal Antibodies Targeting Pcdh7 Inhibit Tumor Growth And Enhance Immune Responses In Kras-Mutant Non-Small Cell Lung Cancer, Nicole Novaresi, Poorva Ghosh, Shayna Thomas-Jardin, Hui Deng, Xuejun Fan, Zhiqiang Ku, Wei Xiong, Xiaorong Zhou, Jingfei Zhu, Huiyu Li, Mahesh S Padanad, Bethany Smith, Chul Ahn, John D Minna, Zhiqiang An, Ningyan Zhang, Kathryn A O'Donnell

The Brown Foundation: Institute of Molecular Medicine

We identified an important oncogenic role for protocadherin 7 (PCDH7), a cell surface protein frequently overexpressed in lung adenocarcinoma and associated with poor clinical outcome. Pcdh7 depletion reduces tumor burden and prolongs survival in KrasLSL-G12D; Tp53fl/fl mice. These findings nominate this cell surface protein as an actionable therapeutic target and highlight the therapeutic potential of PCDH7 inhibition for non–small cell lung cancer. We report the development and characterization of high-affinity anti-PCDH7 monoclonal antibodies (mAbs) that inhibit downstream mitogen-activated protein kinase (MAPK) pathway activation and suppress tumor growth in multiple mutant KRAS–driven models. A lead mAb (mAb7) sensitized tumors …

Amc-F1 Regulates Mitochondria-Autophagy Crosstalk Independent Of Nutrient Stress, Yuqin Wang, Raksha K Rao, Trung Vu, Ayano Sekine, Zhengmei Mao, Nami Mccarty

The Brown Foundation: Institute of Molecular Medicine

Mitochondria and autophagy are fundamental yet distinct regulators of cellular homeostasis. Here, we identify AMC-F1 (Autophagy-Mitochondria Coupling Factor 1; formerly TRIM44) as a central integrator of mitochondrial bioenergetics and autophagy. Using Amcf1 knockout and knock-in mouse models, we demonstrate that AMC-F1 bidirectionally regulates these pathways: its loss reduces mitochondrial respiration and autophagic flux, whereas its overexpression promotes mitochondrial elongation and increases autophagy independently of nutrient stress. Transcriptomic analyses reveal AMC-F1-dependent regulation of mitochondrial biogenesis programs that engage autophagy, involving mitochondrial respiratory chain complex genes under basal conditions and mitochondrial organization factors under starvation-induced autophagy. Although dispensable under homeostasis, this coupling …

Transgenic Hookworm Secretes Anti-Tetrodotoxin Human Single Chain Antibody, Kumar Sachin Singh, Suman Bharti, Bruce A Rosa, Mahdiyeh Bigham, Samuel C Uzoechi, Young-Jun Choi, John C Martin, Danielle Kemper, Slavica Pavlovic Djuranovic, Darren A Pickering, Rachael Ryan, Bethany K Bracken, Maria Elena Bottazzi, Eric C Carnes, Wannaporn Ittiprasert, Matthew Moyle, Paul J Brindley, Alex Loukas, Sergej Djuranovic, Makedonka Mitreva

Faculty, Staff and Students Publications

Biologics, protein- and peptide-based drugs derived from living organisms or cell lines have emerged as effective therapies across a broad range of indications. However, parenteral administration and the need for frequent dosing increase costs and limit compliance, creating an urgent need for innovative platforms capable of continuously, safely, and efficiently delivering sustained biologics in situ within the host. Here, we describe a bioengineered hookworm platform to manufacture and deliver biologic therapeutics in vivo. As proof of concept, we engineer the Ancylostoma ceylanicum secretome by inserting a human single-chain variable fragment antibody (s16-HuScFv) into its genome. Transgene expression does not perturb …

Cytosine Base Editing Of Lpa In Transgenic Mice Averts Large Deletions, Marcel A Chuecos, So Hyun Park, Madhvi M Bhakta, Usosa Too-Chiobi, Daniel Betancourth, Mingming Cao, Marco De Giorgi, Christopher J Walkey, Anjana Tiwari, Biana Godin, Julia M Assini, Donna J Palmer, Philip Ng, Michael B Boffa, Marlys L Koschinsky, Gang Bao, William R Lagor

Faculty, Staff and Students Publications

Lipoprotein(a) (Lp(a)) is a genetically determined causal risk factor for cardiovascular disease, with approximately 20% of the population exhibiting elevated levels. While there are promising drugs in development, there are currently no approved therapies specifically designed to lower Lp(a) levels. For high-risk individuals with extreme levels of Lp(a), liver-directed genome editing could be an effective one-time solution. Genome editing approaches such as CRISPR and TALENs can reduce Lp(a) in LPA-transgenic mouse models, but they frequently induce large and potentially harmful genomic deletions. Here, we report the first application of TadA-derived cytosine base editing (CBE), delivered via helper-dependent adenovirus (HDAdV) and …

An Obligatory Role For Agrp Neurons In Maintaining Body Temperature During Time-Restricted Feeding, Cunjin Su, Jing Cai, Yuanzhong Xu, Benjamin R Arenkiel, Qingchun Tong

The Brown Foundation: Institute of Molecular Medicine

Homeotherms maintain a steady body temperature through thermoregulation, a process critical for survival during fasting, in which the brain has to defend energy-costly body temperature while reducing energy expenditure to conserve energy reserve; however, the neural basis for defending body temperature remains unclear. Here, we demonstrated that AgRP neuron lesion led to lethality during time-restricted feeding on chow but not on HFD, and caused no obvious impact on HFD-induced obesity or obesity-reducing responses to glucagon-like peptide-1 receptor agonism. The lesion disrupted adaptive feeding behaviors during time-restricted feeding and reduced motivational feeding on chow. Notably, the lethality was caused by hypothermia …