Medical Specialties Commons^™

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 …

Development Of A Structurally Distinct Topbp1 Inhibitor That Enhances Parp Blockade And Reverses Osimertinib Resistance, Yang Xiao, Lidija A Wilhelms Garan, Helena Folly-Kossi, Weei-Chin Lin

Faculty, Staff and Students Publications

Therapeutic resistance remains a major challenge in cancer treatment, driven by compensatory signaling and stress response pathways that sustain tumor survival. Topoisomerase IIβ-binding protein 1 (TopBP1), a multifunctional scaffold protein with nine BRCT domains, integrates replication stress signaling with oncogenic networks and is frequently overexpressed in aggressive cancers. Its BRCT7/8 domains mediate critical interactions with E2F1, mutant p53, MIZ1, PLK1, and CIP2A, making TopBP1-BRCT7/8 an attractive therapeutic target. Using docking-guided screening and structure-activity relationship–driven optimization, we developed CS18 as a potent and selective BRCT7/8 inhibitor that disrupts oncogenic TopBP1 complexes without interfering with DNA replication. CS18 suppresses MYC transcriptional programs, …

Endometrial Cells With High Aldh Activity Contribute To Uterine Development And Regeneration, Sydney E Parks, Genesis J Herrera, Ting Geng, Linda Alpuing Radilla, Brooke A Thigpen, Xiaoming Guan, Diana Monsivais

Faculty, Staff and Students Publications

Adult stem cells are thought to drive the regenerative potential of the endometrium and contribute to the pathogenesis of endometriosis; however, their identity and defining features remain to be characterized. Here, we used in vivo and in vitro approaches to demonstrate that cells with high aldehyde dehydrogenase 1 activity (ALDHHI cells) were long-lived progenitors in the endometrium with a higher organoid formation capacity, long-term passaging potential, and stemness gene signatures. Using lineage tracing with an Aldh1a1creERT2/+; Rosa26LSL-tdTomato reporter mouse, Aldh1a1+ epithelial cells expanded during postnatal development, Aldh1a1+ stromal cells expanded during estrous cycling, and both populations of Aldh1a1 …

Protocadherin 9 Promotes Cell Survival Of Different Bipolar Cell Types In The Developing Mouse Retina, Collin Todora, Cesiah C Gomez, Elizabeth Zuniga-Sanchez

Faculty, Staff and Students Publications

Neural circuit assembly relies on different neuronal types coming together to form a functional circuit. The question of how the appropriate number of each type is integrated into an emerging circuit remains relatively unknown. To answer this question, we used the mouse retina to uncover the molecular mechanisms responsible for neuron-type integration in a developing circuit. In the mammalian retina, bipolar cells (BCs) are a class of interneurons that relay visual information from photoreceptors to ganglion cells. Extensive studies have shown there are 15 distinct BC types: 6 types of OFF cone bipolars, 8 types of ON cone bipolars, and …

Non-Enzymatic Hepatic Abhd6 Interacts With Akt-Foxo1 Axis To Regulate Metabolic Health, Guannan Li, Laurence T Maeyens, Jiyuan Yin, Jan-Bernd Funcke, Chanmin Joung, Ruizhen Li, Ziying Xu, Ting Wu, Xin Li, Nisi Jiang, Mbolle Ekane, Maria Paula Lopez, Pengju Cao, Sijia He, Adam B Salmon, S R Murthy Madiraju, Marc Prentki, Juli Bai, James F Nelson, Xianlin Han, Yi Zhu, Shangang Zhao

Children’s Nutrition Research Center Staff Publications

The enzymatic role of ABHD6 in insulin secretion and resistance is well documented. However, its non-enzymatic function, especially its effects on metabolic health, including selective hepatic insulin resistance and metabolic dysfunction-associated steatotic liver disease (MASLD), is poorly understood. To define the role of ABHD6 in liver physiology, we generated liver-specific ABHD6 knockout mice, as well as liver-specific native and enzymatically inactive mutant ABHD6 overexpression mouse models. We demonstrate that non-enzymatic ABHD6 contributes to the regulation of selective hepatic insulin resistance and MASLD progression. Mechanistically, we show that ABHD6 localizes to the nucleus and interacts with Akt/FoxO1 axis to regulate insulin …

Targeting Oncogenic Flt3 Uncovers A Ferroptosis Vulnerability Through Selenocysteine Recoding In Acute Myeloid Leukaemia, Ken Furudate, Ayumi Kitano, Taotao Tan, Mengdie Feng, Jing Zhou, Tao Wang, Robert J Taylor, Alexandra M Stevens, Md Abul Hassan Samee, Jeffrey A Magee, Koichi Takahashi, Daisuke Nakada

Faculty, Staff and Students Publications

Ferroptosis, an iron-dependent form of cell death driven by lipid peroxidation, has emerged as a potential therapeutic strategy for therapy-resistant cancers. Glutathione peroxidase 4 and the selenoprotein biosynthesis pathway essential for its translation are key regulators of ferroptosis but lack effective therapeutic targeting. In a drug screening using a selenoprotein translation reporter, here we identify FMS-like tyrosine kinase 3 (FLT3) inhibitors as suppressors of selenoprotein translation that induce ferroptosis in FLT3-mutant acute myeloid leukaemia. Mechanistically, FLT3 inhibition disrupts selenocysteine recoding, in which a UGA stop codon is recoded as selenocysteine via the SECIS element and associated binding proteins. Notably, the …

Hyperadhesive Von Willebrand Factor Contributes To Pathogenesis Of Preeclampsia, Yajuan Wang, Chenyu Wang, Katie L Houck, Xiaoli Gao, Yuanyuan Chen, Xin Xu, Xue Zhao, Miguel A Cruz, Shu Zhang, Chester Q Li, Fengxia Xue, Min Li, Swati Shree, Jing-Fei Dong, Cha Han

Children’s Nutrition Research Center Staff Publications

Background: Preeclampsia is the most common complication of pregnancy, significantly affecting maternal and fetal health, and is characterized by placental and systemic endotheliopathy. Patients with preeclampsia have elevated levels of VWF (von Willebrand Factor), which is associated with poor clinical outcomes. However, whether VWF serves as a marker for endotheliopathy or contributes to the pathogenesis of preeclampsia remains poorly understood.

Methods: We investigated the role of hyperadhesive VWF in the development of preeclampsia by studying patients, evaluating mouse models, and performing in vitro experiments.

Results: We show that patients develop VWF- and fibrin-rich thrombosis in the placenta and have significantly …

Fibrinogen And Lipopolysaccharide Promote Tlr4-Dependent Glucocorticoid Resistance In Airway Mycosis-Driven Allergic Airway Disease, Y Zeng, X Huang, G Liang, K Tang, K E Mauk, H Sun, Y Zhang, Z Zeng, L Song, K Polsky, Y Wu, C T Landers, E Z Otukoya, L H Bimler, F Kheradmand, A U Luong, Y Guo, J M Knight, D B Corry

Faculty, Staff and Students Publications

Glucocorticoid-refractory asthma is a severe disease type linked to both T helper type 2 (T2) high and T2 low, neutrophil-high asthma endotypes, but the mechanisms governing glucocorticoid resistance are largely unknown. We show that glucocorticoid-resistant mouse allergic airway disease is linked to airway mycosis and lung-specific production of fibrinogen cleavage products (cryptokines). Mice challenged with the allergenic fungus Aspergillus niger and low-dose inhaled lipopolysaccharide (LPS) showed exaggerated airway hyperresponsiveness (AHR), developed T2 high and neutrophilic airway inflammation recapitulating severe asthma. AHR was not attenuated by glucocorticoid therapy, but required expression of Toll-like receptor 4 (TLR4). Low-dose intranasal LPS alone induced …

The Environmental Polycyclic Aromatic Hydrocarbon (Pah) Benzo[A]Pyrene (Bp) Alters Sars-Cov-2 Pathogenesis In A Mouse Model Of Disease, Yike Jiang, Weiwu Jiang, Sarah Strobel, Fong W Lam, Bhagavatula Moorthy, Shannon E Ronca

Faculty, Staff and Students Publications

Since emerging in late 2019, SARS-CoV-2 has caused over 7 million deaths globally and remains a public health concern. Understanding SARS-CoV-2 pathogenesis is vital, especially as factors like environmental exposures are still poorly understood. Polycyclic aromatic hydrocarbons (PAHs), like benzo[a]pyrene (BP), found in pollutants like cigarette smoke, diesel exhaust, and charcoal-broiled steaks, are known to injure the lungs. We aimed to evaluate if BP exacerbates SARS-CoV-2 pathogenesis in a mouse model of disease. One day following intranasal administration of BP (20 mg/kg) or vehicle control, we infected male and female K18-hACE2 mice with ancestral SARS-CoV-2 and assessed lung viral load, …

Pathogenic Myeloid Phenotypes Drive Disease Pathology In A Novel Human Neurohistiocytosis Model, Anna S Warden, Amanda M Wilpitz, Bing Xia, Celina Nguyen, Hilda Ding, Jennifer Picarsic, Christopher K Glass, Carl E Allen, Nicole G Coufal

Faculty, Staff and Students Publications

Innate immunity is increasingly recognized as a driver of neurodegeneration, although pathogenic mechanisms are incompletely understood. Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplastic disorder caused by activating somatic mutations in MAPK pathway genes, most commonly BRAFV600E, in myeloid precursors. A subset of patients with LCH develop progressive neurodegeneration (LCH-ND). We generated a human induced pluripotent stem cell (iPSC) model from patients with somatic hematologic mosaicism for BRAFV600E. Brain macrophages/microglia from LCH iPSCs exhibit unique disease-specific pathogenic features. Stepwise differentiation identified hematopoietic progenitors as hyperproliferative, whereas brain macrophages were apoptosis resistant. Through application of cerebral organoids and a humanized …

Fucci-G1 Insertion Partially Disrupts Shh Expression, Yuka Morikawa, Ann Bromley, Jeffrey D Steimle, James F Martin

Faculty, Staff and Students Publications

The Fucci mouse lines are valuable tools for tracing cell cycle stages during development and in postnatal tissues; however, the insertion loci for the transgenes remain unidentified. Here, we report the genomic insertion sites of both the Fucci-G1 and -S/G2/M transgenes, identified through whole-genome sequencing. Interestingly, the Fucci-G1 transgene is located proximal to the Shh lung gut enhancer (SLGE) on chromosome 5. Homozygous Fucci-G1 embryos are perinatal lethal but survive until embryonic day (E)18.5, exhibiting craniofacial and foregut-related defects. Expression of Shh and canonical targets are downregulated in the pharyngeal arches of E11.5 homozygous Fucci-G1 embryos. Furthermore, in situ hybridization …

Combining Menin And Mek Inhibition To Target Poor Prognosis Kmt2a-Rearranged Ras Pathway-Mutant Acute Myeloid Leukemia., Nastassja Scheidegger, Constanze Schneider, Gabriela Alexe, Yi-Cheng Wang, Todd A. Alonzo, Allen Basanthakumar, Wallace A. Bourgeois, Julia Dudkiewicz-Garbicz, Delan Khalid, Lucy A. Merickel, Jennifer A. Perry, Rhonda E. Ries, Silvi Salhotra, Audrey Taillon, Alan S. Gamis, Richard Aplenc, Marian H. Harris, Mark Wunderlich, Scott A. Armstrong, Jessica A. Pollard, Soheil Meshinchi, Yana Pikman, Kimberly Stegmaier

Manuscripts, Articles, Book Chapters and Other Papers

KMT2A-rearranged (KMT2A-r) acute leukemias are especially prevalent in the pediatric population. KMT2A-fusion proteins drive leukemogenic gene expression through an interaction with a chromatin complex that includes the scaffold protein menin, giving rise to aggressive acute leukemias. RAS pathway mutations are also common in pediatric leukemia. In a cohort of 1750 patients enrolled on Children's Oncology Group (COG) trials, we identified RAS pathway mutations in 43% of acute myeloid leukemia (AML) cases. The presence of RAS pathway mutations in KMT2A-r AML was associated with a lower complete remission rate, poor event-free survival and overall survival (OS), and early relapses. Given the …

Oncogenic Pik3ca Reprograms Glutamine Metabolism To Drive Bladder Cancer Progression, Jun Hyoung Park, Aaditya Krishna Arun, Sachin B Jorvekar, Yongchao Dou, Mohammed Khurshidul Hassan, Chandra Sekhar Amara, Abu Hena Mostafa Kamal, Chandra Shekar R Ambati, Jun Xu, Daniel Kraushaar, Adriana Langer Gramer, Allison C Bellman, Leomar Y Ballester, Yuan Xu, Robert Taylor Ripley, Seth P Lerner, Roni J Bollag, Martha K Terris, Chong-Xian Pan, Benny Abraham Kaipparettu, Yair Lotan, Nagireddy Putluri

Faculty, Staff and Students Publications

Background: Genomic analysis has revealed that approximately 40% of bladder cancer (BLCA) tumors harbor alterations in the PI3K/AKT pathway, with PIK3CA mutations occurring in 15-25% of cases. PIK3CA, which encodes the catalytic p110α subunit of PI3K, plays a critical role in regulating cell survival, proliferation, and metabolism. However, the metabolic and functional consequences of PIK3CA mutations in BLCA remain poorly defined.

Methods: To investigate the role of PIK3CA mutations in BLCA, we performed targeted sequencing on tumors from patients, identifying recurrent alterations. Using CRISPR/Cas9 knock-in models in SCaBER and UM-UC-3 cell lines, we introduced the PIK3CA E545K mutation to study …

Loss Of Tumor Suppressor Nf2 Mediates Resistance To Car T Cell And Anti-Pd-1 Therapy: Strategies To Restore Immunotherapy Sensitivity, Miguel A Lopez-Lago, Meriem Taleb, Mehek Ningoo, Tomoyo Okada, Xiaoyu Li, Hyun-Sung Lee, Bryan M Burt, Michael Offin, Navin K Chintala, Prasad S Adusumilli

Faculty, Staff and Students Publications

Background: Investigating the biological mechanisms of acquired resistance to immunotherapy remains a necessity for effective treatment of solid tumors.

Methods: Diffuse pleural mesothelioma (DPM) tumors, from immunocompetent and immunodeficient mouse models with acquired resistance to chimeric antigen receptor (CAR) T cell therapy were analyzed using flow cytometry, immunofluorescence, and ELISA. The interplay between genetic alterations in the cancer cell and site-specific tumor immune microenvironment (TIME) was characterized; therapies to reverse immunotherapy resistance were investigated.

Findings: Analysis of tumors with acquired resistance to CAR T cell therapy demonstrated lower expression of tumor suppressor NF2. Enforced depletion of NF2 promoted resistance to …

Lats1/2-Cd38 Metabolic Rewiring Links Senescence To Intraplaque Thrombosis, Sivareddy Kotla, Jonghae Lee, Kyung Ae Ko, Weiqing Chen, Venkata Subrahmanya Kumar Samanthapudi, Oanh Hoang, Gilbert F Mejia, Shengyu Li, Hani Lee, Aijun Zhang, Min Soon Cho, Keri L Schadler, Luis Antonio Rivera, Masaki Imanishi, Kay Carlene Tavares Samperio, Jung Hyun Kim, Kelia C Ostos-Mendoza, Karla N Mariscal-Reyes, Anita Deswal, John P Cooke, Keigi Fujiwara, Nicolas L Palaskas, Efstratios Koutroumpakis, Young Jin Gi, Rajneesh Pathania, Craig Morrell, Philip L Lorenzi, Lin Tan, Iqbal Mahmud, Nordin M J Hanssen, Vahid Afshar-Kharghan, Dale J Hamilton, Laurent Yvan-Charvet, Eduardo N Chini, Joerg Herrmann, Hernan G Vasquez, Ying H Shen, James F Martin, Haodong Xu, Erin H Seeley, Jared K Burks, Paul S Brookes, Guangyu Wang, Nhat-Tu Le, Jun-Ichi Abe

Faculty, Staff and Students Publications

Background: Atherothrombosis, which underlies most acute coronary syndromes and is driven by intraplaque thrombosis, preferentially occurs in regions of disturbed blood flow (d-flow). Although LATS1/2 (large tumor suppressor kinases 1 and 2) are known regulators of endothelial mechanotransduction, the mechanisms by which d-flow connects endothelial senescence, proliferation, and intraplaque thrombosis remain poorly understood.

Methods: We investigated endothelial cell (EC)-specific roles of Lats1/2 using inducible EC-specific knockout mice in a partial carotid ligation model. Spatial multiomics of human and mouse plaques was performed using imaging mass cytometry, COMET sequential immunofluorescence, and spatial metabolomics.

Results: Tamoxifen-induced deletion of both Lats1 and Lats2 …

Bi-Allelic Loss-Of-Function Variants In Tmem63b Cause Syndromic Surfactant Dysfunction Disorder, 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 …

Reciprocal Compensation Of Caspase-2 And P53 Regulates The Dna Damage Response In Hct116 Colon Cancer Cells, Karen Zúñiga, Sarah Wright, Lisa Bouchier-Hayes

Faculty, Staff and Students Publications

Caspase-2 has positive and negative effects on tumor growth in different cancer models. The mechanisms determining these dual outcomes of caspase-2 activation are unclear underscoring the need to assess caspase-2 function in different cell types. We report that high caspase-2 expression is associated with lower survival in patients with colon cancer and increased tumor size in HCT116 colon cancer xenografts. We investigated the interplay between caspase-2 and p53 in regulating the proliferation of these cells. While neither of these proteins had much of an effect on cell cycle arrest on their own, deficiency in both caspase-2 and p53 led to …

Proteogenomics Of Hypertrophic Cardiomyopathy Reveals Subtype-Specific Therapy, Ke Ma, Jie Yang, Hongchang Guo, Ping Li, Xiaowei Li, Zhujun Dong, Jing Zhang, Congcong Zhang, Pengli Yang, Chongpei Hua, Shuolin Zhu, Guoqing Li, Jianchao Zhang, Ningyu Ding, Jizheng Wang, Xin-Liang Ma, Zhuofeng Lin, Jianzeng Dong, Yang Li, Yulin Li

Department of Emergency Medicine Faculty Papers

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is a heterogeneous disease with diverse prognosis. The underlying mechanisms remain unknown, resulting in limited risk stratification and therapeutic strategies. This study aimed to elucidate molecular subtypes of HCM through integrated proteogenomic analysis and explore subtype-specific therapeutic strategies.

METHODS: We conducted an integrated proteogenomic analysis of 132 patients with HCM using myocardial samples, incorporating whole-exome sequencing, RNA sequencing, and proteomics. Unsupervised clustering was used to identify HCM subtypes, which were validated in heart tissues and human induced pluripotent stem cell-derived cardiomyocytes from 2 independent HCM subsets. Subtype-specific signatures and pathways were explored, and their causal link …

Statistics Of Natural Scenes Shape Contextual Modulation In The Visual Cortex, 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 …

Chemotherapeutic Induction Of Cytosolic Single-Stranded Dna Accumulation Sensitizes Triple-Negative Breast Cancer To Immunotherapy, 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, …

Folr1-Targeted Actinium-225-Based Alpha-Particle Therapy Eliminates Ovarian Cancer, Neetu Singh, Esther Need, Ayden Berndt, Matthew Goff, Lydia J. Wilson, Firas Mourtada, Feng Guo, Tara Mastren, Taslim Al-Hilal, Anil K. Sood, Amit Maity, Scott C. Miller, Satoshi Minoshima, Shreya Goel, Sixiang Shi

Department of Radiation Oncology Faculty Papers

Despite the advancement in therapies, ovarian cancer treatment is challenging because of poor prognosis and high relapse associated with acquired resistance. Emerging targeted alpha particles, particularly actinium-225 (225Ac), for treating refractory cancers have opened avenues for improved therapeutic options. Here, we describe a successful example of folate receptor 1 (FOLR1)–targeted 225Ac alpha-particle therapy for treatment of ovarian cancer. Longitudinal positron emission tomography imaging demonstrated high tumor-specific uptake of αFOLR1 (anti-FOLR1 antibody) in SKOV3 xenografts. FOLR1-targeted 225Ac demonstrated high therapeutic efficacy, achieving marked tumor regression, 80% survival, and 40% complete tumor elimination. The therapy resulted in tumor-specific double-stranded DNA damage, and …

Neddylation Maintains Oocyte Quality By Stabilizing Mitochondrial Transcription, 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 …

Intrathecal (G4c2)149 Delivery In C9orf72-Deficient Mice Yields Mild Motor Dysfunction And Als/Ftd Pathological Hallmarks, Katelyn Russell, Amelia Shahrabi, Suleyman Akerman, Matthew D. Byrne, Jeffrey Rothstein, Davide Trotti, Brigid Jensen, Aaron Haeusler

Farber Institute for Neuroscience Faculty Papers

A repeat expansion in C9ORF72 is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), yet existing mouse models incompletely engage spinal regions implicated in disease. Here, an adeno-associated virus encoding (G4C2)149 repeats was delivered via neonatal intrathecal injection, achieving widespread CNS expression with robust spinal cord targeting. This approach was applied to mice with graded loss of endogenous C9orf72 to interrogate both gain- and loss-of-function mechanisms. Longitudinal motor, behavioral, and pathological analyses revealed that repeat expression primarily drives mild, progressive muscle weakness, whereas coordination deficits were largely genotype dependent. Subtle gait abnormalities and hyperactivity …

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 …

Macropinocytosis Inhibition Attenuates Profibrotic Responses In Lung Fibroblasts And Pulmonary Fibrosis Models, 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, 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

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, 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 …

Inhibition Of Calpain-Mediated Hmgb1 Alleviates Cardiac Inflammation And Dysfunction Induced By Ultra-Processed Foods, Claire Ross, Sanskruti Ravindra Gare, Nasser Ho Alatawi, Oveena Fonseka, Xinyi Chen, Jiayan Zhang, Yihua Han, Andrea Ruiz-Velasco, Riham Re Abouleisa, Yingjuan Liu, Xiangjun Zhao, Han Xiao, Bernard D Keavney, Gareth J Howell, Tao Wang, Tamer Ma Mohamed, Elizabeth J Cartwright, Wei Liu

Faculty, Staff and Students Publications

Increased consumption of ultra-processed foods (UPFs) is a risk factor for metabolic disorder-associated heart failure (HF). Here, we demonstrate that UPF-induced calpain-1 aggravated oxidative stress, thereby increasing high mobility group box 1-mediated (HMGB1-mediated) myocardial inflammation, which contributes to cardiac dysfunction. After illustrating the dysregulated inflammatory pathways in human and murine hearts upon metabolic stress, we revealed an increase in calpain-1 alongside profound oxidative stress and inflammation in the failing myocardium. Mechanistically, in neonatal rat cardiomyocytes and human induced pluripotent stem cell-derived cardiomyocytes, HMGB1 was upregulated by calpain-1 and reactive oxygen species (ROS) upon stress of saturated and trans fatty acids. …

Disease-Causing Mfn2 Mutants Impair Mitochondrial Fission Dynamics By Distinct Drp1 Dysregulation, Daniel Lagos, Pamela R. De Santiago, Nicolás Pérez-Bravo, Benjamín Cartes-Saavedra, Josefa Vial-Brizzi, Diego Troncoso-Chandía, Oliver Podmanicky, Rita Horvath, Verónica Eisner

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Mitochondria undergo fusion and fission. While DRP1 regulates fission, fusion is controlled by OPA1, MFN1, and MFN2. The balance between these processes and the crosstalk between machineries remains poorly understood. MFN2 mutations cause Charcot-Marie-Tooth disease type 2 A (CMT2A), affecting mitochondrial fusion and morphology. However, their role in fission is unclear. Using skin fibroblasts from CMT2A patients (L248H and M376V MFN2 mutations) and wild-type mouse embryonic fibroblasts expressing these variants, we studied how MFN2 mutations impact mitochondrial dynamics beyond fusion. We analyzed mitochondrial morphology and dynamics by live-cell confocal microscopy and tested fusion/fission protein levels, oxygen consumption rate (OCR), extracellular …