Medical Sciences Commons^™

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 …

Mbnl Loss Of Function In Smooth Muscle As A Model For Myotonic Dystrophy Associated Gastrointestinal Dysmotility, Janel A M Peterson, Jesus A Frias, Andrew N Miller, Krishnakant G Soni, Yi Zhang, Zheng Xia, John W Day, Geoffrey A Preidis, Thomas A Cooper

Faculty, Staff and Students Publications

Myotonic dystrophy type 1 (DM1) is the most common adult-onset muscular dystrophy and severely affects multiple organ systems, including the brain, heart, skeletal muscle, and gastrointestinal (GI) tract. Despite 80% of individuals with DM1 experiencing GI dysfunction that affects their daily life, the mechanisms of GI dysmotility in DM1 remain an understudied aspect of the disease. DM1 is caused by a CTG repeat expansion in the DMPK gene that, when expressed as an expanded CUG repeat RNA, sequesters and reduces the activity of the muscleblind-like (MBNL) RNA-binding protein family. We developed a mouse line with conditional, smooth muscle-specific knockout of …

Lung Adenocarcinoma Surfaceome Remodeling With Egfr Inhibitors Uncovers Placental Alkaline Phosphatase As A Target For Combination Therapy, Yihui Chen, Rongzhang Dou, Monica J Hong, Hanwen Xu, Jody Vykoukal, Ricardo A León-Letelier, Yining Cai, Soyoung Park, Ehsan Irajizad, Fu Chung Hsiao, Jennifer B Dennison, Edwin J Ostrin, Johannes F Fahrmann, Hiroyuki Katayama, Samir M Hanash

Faculty, Staff and Student Publications

Treatment of lung adenocarcinomas (LUADs) that exhibit activated epidermal growth factor receptor (EGFR) with EGFR tyrosine kinase inhibitors (TKIs) has limited efficacy. Assessment of the impact of EGFR TKI on the LUAD surfaceome remodeling reveals potential therapeutic targets. We identify placental type alkaline phosphatase (ALPP), which has restricted expression in normal tissues, among upregulated surface proteins following EGFR TKI treatment of both TKI sensitive as well as resistant cells. EGF treatment represses ALPP expression, whereas EGFR TKIs upregulate its expression through dephosphorylation and activation of FoxO3a, a transcriptional regulator that binds to the promoter region of ALPP. The combination of …

Vesicle-Mediated Mitochondrial Clearance Presents An Actionable Metabolic Vulnerability In Triple-Negative Breast Cancer, Jody Vykoukal, Yihui Chen, Mingxin Zuo, Riccardo Ballarò, Monica J Hong, Hansini Krishna, Daniela B Rodriquez-Perera, Hiroyuki Katayama, Ehsan Irajizad, Ranran Wu, Ricardo A León-Letelier, Jennifer B Dennison, Angelica M Gutierrez, Adriana Paulucci-Holthauzen, Timothy C Thompson, Leona Rusling, Yining Cai, Fu Chung Hsiao, Soyoung Park, Banu Arun, Samir Hanash, Johannes F Fahrmann

Faculty, Staff and Student Publications

Selective autophagy of mitochondria is known to promote cancer cell survival and progression, including in triple-negative breast cancer (TNBC). Here, we apply an integrated multi-omics approach together with functional experimental analyses to investigate metabolic adaptations that support mitochondrial quality control in TNBC. We detail a mitochondrial quality control mechanism, complementary to mitophagy, that is enabled by a program of heightened extracellular sphingomyelin salvaging in TNBC coupled with extracellular vesicle-mediated intracellular clearance of mitochondrial damage. Targeting of this onco-metabolic pathway via repurposing of eliglustat, a selective small molecule inhibitor of glucosylceramide synthase, results in ceramide-mediated compensatory mitophagy and cancer cell death …

Facts And Hopes Of Chimeric Antigen Receptor-Redirected Nk T Cells, Amy N Courtney, Xin Zhou, Gengwen Tian, Ying Wang, Leonid S Metelitsa, Gianpietro Dotti

Faculty, Staff and Students Publications

Chimeric antigen receptor (CAR)-engineered invariant NK T cells (CAR-NKT) are a novel cell platform for cancer immunotherapy. Unlike conventional T cells, NKTs are characterized by innate antitumor properties, minimal alloreactivity, and a unique ability to modulate the tumor microenvironment. This article provides a comprehensive overview of preclinical and early clinical studies evaluating CAR-NKTs in both autologous and allogeneic clinical settings. We discuss the contributions of CAR signaling domains, cytokine coexpression, and other functional measures that correlate with CAR-NKT persistence, function, and metabolic fitness. We also discuss the critical role of immunocompetent animal models in elucidating the interactions of CAR-NKTs with …

Mitochondrial Complex Ii Orchestrates Divergent Effects In Cd4+ And Cd8+ T Cells, Keisuke Seike, Shih-Chun A Chu, Yuichi Sumii, Takashi Ikeda, Meng-Chih Wu, Laure Maneix, Dongchang Zhao, Yaping Sun, Marcin Cieslik, Pavan Reddy

Faculty, Staff and Students Publications

Mitochondrial metabolism orchestrates T cell functions, yet the role of specific mitochondrial components in distinct T cell subsets remains poorly understood. Here, we explored the role of mitochondrial complex II (MC II), the only complex from the electron transport chain (ETC) that plays a role in both ETC and metabolism, in regulating T cell functions. Surprisingly, MC II exerts divergent effects on CD4+ and CD8+ T cell activation and function. Using T cell-specific MC II subunit, succinate dehydrogenase A-deficient (SDHA-deficient) mice, we integrated single-cell RNA-seq and metabolic profiling, with in vitro and in vivo T cell functional assays to illuminate …

Targeting Kinesin Family Member 20a Sensitizes Stem-Like Triple-Negative Breast Cancer Cells To Standard Chemotherapy, Yayoi Adachi, Weilong Chen, Cheng Zhang, Tao Wang, Nina Gildor, Rachel Shi, Haoyong Fu, Masashi Takeda, Qian Liang, Fangzhou Zhao, Hongyi Liu, Jun Fang, Jin Zhou, Hongwei Yao, Lianxin Hu, Shina Li, Lei Guo, Lin Xu, Ling Xie, Xian Chen, Chengheng Liao, Qing Zhang

Faculty, Staff and Student Publications

Triple-negative breast cancer (TNBC), being both aggressive and highly lethal, poses a major clinical challenge in terms of treatment. Its heterogeneity and lack of hormone receptors or HER2 expression further restrict the availability of targeted therapy. Breast cancer stem cells (BCSCs), known to fuel TNBC malignancy, are now being exploited as a vulnerability for TNBC treatment. Here, we dissected the transcriptome of BCSCs and identified kinesin family member 20A (KIF20A) as a key regulator of BCSC survival and TNBC tumorigenesis. Genetic depletion or pharmacological inhibition of KIF20A impairs BCSC viability and tumor initiation and development in vitro and in vivo. …

Low-Dimensional Signatures Of Neuronal Activity Associated With Long-Term Operant Conditioning In Aplysia, Sara Vanaki, Nicholas O Gonzalez, Curtis L Neveu, Yuto Momohara, Behnaam Aazhang, John H Byrne

Faculty, Staff and Student Publications

Operant conditioning is a form of learning in which a behavior is reinforced by reward. Operant conditioning has multiple temporal domains, ranging from short-term, lasting a few minutes, to long-term, persisting for at least 24 h. The extent to which short- and long-term operant conditioning memories rely on shared or separate neural mechanisms is poorly understood. Voltage-sensitive dye (VSD) imaging has been used previously to record the activity of a large number of neurons simultaneously in the buccal ganglion to measure changes in neuronal activity during short-term operant conditioning. We examined neuronal activity using VSD 24 h after operant conditioning …

A Long Non-Coding Rna Leat1 Mediates The Hormone Responsiveness Of Efnb2 During Male Urogenital Development, Deidre Mattiske, Pascal Bernard, Paul E Gradie, Richard R Behringer, Paul A Overbeek, Rachel J O'Neill, Tiffany Phillips, Melanie Stewart, Neil Youngson, Gerard Tarulli, Andrew J Pask

Faculty, Staff and Students Publications

The novel long non-coding RNA (lncRNA) Leat1 is extraordinarily conserved in both its location (syntenic with EfnB2, an essential gene in anogenital patterning) and sequence. Here we show that Leat1 is upregulated following the production of testosterone from the developing testis in mice and interacts with EfnB2, positively regulating its expression. Leat1 expression is suppressed by estrogen, which in turn suppresses the expression of EfnB2. Moreover, the loss of Leat1 leads to reduced EfnB2, resulting in a severe hypospadias phenotype. The human LEAT1 gene is also co-expressed with EFNB2 in the developing human penis, suggesting a conserved function for this …

Protein-Nucleic Acid Language Model-Assisted Design Of Precise And Compact Adenine Base Editor, Jingxuan Ren, Jiawei Yao, Qiuyu Cao, Yinuo Li, Yang Li, Ziyi Zhang, Xiyu Ge, Shengfang Wang, Yang Zhang, Xiaogang Wang, Xiaohui Zhang

Faculty, Staff and Students Publications

Adenine base editors (ABEs) are powerful tools for gene therapy. However, efficient version of ABEs (e.g. ABE8e) always induce excessive bystander and off-target editing events and are large in size, hindering their potential in clinical disease treatment. Here, we develop a pre-trained Protein-Nucleic Acid Constrained Language Model to design ABE8e with high activity, reduced editing window and decreased size. By further engineering, the smallest ABE8e- PNLM-pcABE- with a 27% size reduction, exhibits high activity, precise 3-nt editing window, and reduced off-target events near background level in HEK293T cells. Compared to ABE8e, PNLM-pcABE has up to 133.5-fold precision improvement in pathogenic …

Agpat2 Acts At The Crossroads Of Lipid Biosynthesis And Drp1-Mediated Er Morphogenesis, Yoshihiro Adachi, Mauricio Torres, Allen H Hunter, Woo Jung Cho, Meixia Pan, Xianlin Han, Guangwei Du, Ling Qi, Miho Iijima, Hiromi Sesaki

Faculty, Staff and Student Publications

The morphology of the endoplasmic reticulum (ER), characterized by central sheets and peripheral tubules, is controlled by membrane-shaping proteins. However, the role of lipids in ER morphogenesis remains elusive, despite the ER being the major site for lipid synthesis. Here, by examining the role of eighteen phosphatidic acid (PA)-generating enzymes in ER morphology, we identify lysophosphatidic acid acyltransferase 2 (AGPAT2) as a critical factor in mouse and human cells. AGPAT2 produces PA in the glycerophospholipid/triacylglycerol biosynthesis pathway, and its mutations cause congenital generalized lipodystrophy. We find that AGPAT2-generated PA drives ER tubulation through gene knockout, 3D structural analysis by FIB-SEM, …

Structural Basis Of Panx1 Permeation And Positive Modulation By Mefloquine, Yangyang Li, Zheng Ruan, Junuk Lee, Ian Orozco, Edward Zhou, Juan Du, Wei Lü

Department of Biochemistry and Molecular Biology Faculty Papers

Purinergic signaling relies on ATP release through exocytosis and large-pore channels. Large-pore channels permeate both small anions like chloride and large signaling molecules like ATP, but how this broad cargo selectivity is structurally controlled remains elusive. Here we investigate PANX1, a prototypical large-pore channel, and uncover structural plasticity at the extracellular entrance formed by seven tryptophan (W74) residues. The W74 sidechains are flexible, sampling conformations that range from a constricted state permissive only to chloride to a dilated state compatible with ATP. These states are coupled to variable cation-π interactions between W74 and arginine 75 (R75), suggesting a mechanism for …

Seed Amplification Of Msa Alpha-Synuclein Aggregates Preserves The Biological And Structural Properties Of Brain-Derived Aggregates, Fei Wang, Victor Banerjee, Carla Barria, Santiago Ramirez, Tyler Allison, Damian Gorski, Haley Evans, Quynh Nguyen, Danielle Harrison, Rabab Al-Lahham, Nicole De Gregorio Carbonell, Michelle Pinho, Sanne Kaalund, Jonas Folke, Susana Aznar, Luis Concha-Marambio, Mohd Ishtikhar, Venkata Kps Mallampalli, Sandra Pritzkow, Mohammad Shahnawaz, Matthew L Baker, Irina Serysheva, Claudio Soto

Faculty, Staff and Student Publications

Parkinson's disease (PD), Dementia with Lewy bodies (DLB), and multiple system atrophy (MSA), are characterized by the misfolding and aggregation of alpha-synuclein (αSyn). Compelling evidence showed that αSyn aggregates exist as distinct conformational strains in different synucleinopathies. Recently, we reported that the αSyn Seed Amplification Assay (αSyn-SAA) can amplify and distinguish αSyn strains from PD and MSA. In this study, we investigate whether MSA-seeded, SAA-amplified αSyn fibrils retain the biological and structural properties of the αSyn seeds present in MSA brains. We study the biological activities of both brain-derived and SAA-amplified αSyn aggregates using an αSyn "biosensor" cell model and …

Tgfbr2 Coordinates The Endometrial Response To Estrogen, Regulating Endometrial Hyperplasia And Fertility, Sydney E Parks, Suni Tang, Anna Catherine Unser, Ananya L Bhonsley, Eunbi M Chung, Peixin Jiang, Audrey Savolainen, Vanessa J Joseph, Dominique I Cope, Ramya P Masand, Renata Prunskaite-Hyyryläinen, Diana Monsivais

Faculty, Staff and Students Publications

Proper endometrial function is critical for establishing and maintaining healthy pregnancies, as well as preventing the pathogenesis of conditions such as endometrial hyperplasia and endometrial cancer. The TGFβ signaling pathway regulates key aspects of endometrial biology, although the direct effects of many individual receptors remain unstudied. In this study, we characterize the role of TGFβR2 within the endometrium using a progesterone receptor-cre conditional knock-out mouse model (Tgfbr2flox/flox;Pgrcre/+; “Tgfbr2 cKO”). We found that conditional deletion of TGFβR2 resulted in female infertility, endometrial hyperplasia, altered estrogen and progesterone response, and, only in bred females, reproductive tract …

Actin Dysregulation Induces Neuroendocrine Plasticity And Immune Evasion: A Vulnerability Of Small Cell Lung Cancer, Yoojeong Seo, Shengzhe Zhang, Jinho Jang, Kyung-Pil Ko, Kee-Beom Kim, Yuanjian Huang, Dong-Wook Kim, Bongjun Kim, Gengyi Zou, Jie Zhang, Sohee Jun, Wonhong Chu, Nicole A Kirk, Ye Eun Hwang, Young Ho Ban, Shilpa S Dhar, Joseph M Chan, Min Gyu Lee, Charles M Rudin, Kwon-Sik Park, Jae-Il Park

Faculty, Staff and Student Publications

Small cell lung cancer (SCLC) is an aggressive malignancy with limited therapeutic options. Capping protein inhibiting regulator of actin dynamics (CRACD) that promotes actin polymerization, is frequently inactivated in SCLC. However, the role of CRACD loss in SCLC is unknown. Here we show that CRACD depletion drives neuroendocrine (NE) cell plasticity and immune evasion in SCLC. Mechanistically, CRACD inactivation disrupts actin organization, leading to suppression of Yap1-NOTCH signaling and subsequent NE gene upregulation. Simultaneously, CRACD loss drives EZH2-mediated histone methylation via nuclear actin disruption, leading to repression of MHC-I genes and depletion of CD8⁺ T cells. Consequently, CRACD-downregulated tumors exhibit …

Yap-Induced Glycolysis Drives Fibroinflammation And Disrupts Fibroblast Fidelity, Chang-Ru Tsai, Lin Liu, Yi Zhao, Jong H Kim, Paulo Czarnewski, Rich Gang Li, Fansen Meng, Mingjie Zheng, Jeffrey Steimle, Xiaolei Zhao, Francisco Grisanti, Zheng Sun, Jun Wang, Md Abul Hassan Samee, Xiao Li, James F Martin

Faculty, Staff and Students Publications

Background: Separation of the pulmonic and systemic circulation is essential for terrestrial life, and mammals have evolved distinct cardiac chambers with specialized structures and functions. Transcriptomics profiling revealed cellular heterogeneity between heart chambers. However, the mechanisms underlying chamber-specific transcriptomic and metabolic differences-and their functional significance-remain poorly understood. The Hippo/YAP (yes-associated protein) pathway is a conserved signaling network that regulates diverse cellular processes. The Hippo kinases inhibit YAP in cardiac fibroblasts (CF) to restrict fibrosis and inflammation. Nonetheless, how YAP regulates the metabolic microenvironment during homeostasis and fibroinflammation remains unclear.

Methods: We investigated YAP and glycolysis activity in the 4 cardiac …

A Mouse Model Of Lipoatrophy Reveals Relationships Between Beige Fat Appearance And Female Fertility, Elizabeth S Anaya, William Dion, Pradip K Saha, Aaron R Cox, Evelyn De Groot, Avery A Ahmed, Jessica B Felix, Bokai Zhu, Stephanie A Pangas, Sean M Hartig

Faculty, Staff and Students Publications

White adipose tissue (WAT) performs vital metabolic and endocrine functions, but roles in female reproduction remain understudied and poorly understood. Here, we report that female mice experiencing progressive lipoatrophy after knockout of Ubc9 in adipocytes (Ubc9fKO) displayed disrupted estrous cycles, reduced ovarian reserve, and subfertility. During aging, female Ubc9fKO mice lose subcutaneous WAT more quickly than their male counterparts and weigh less than littermate controls. Subcutaneous WAT excised from female Ubc9fKO mice strongly enriched for thermogenesis genes generally associated with metabolic benefits. Female Ubc9fKO mice exhibited hypermetabolism and accumulated thermogenic, Uncoupling Protein 1-expressing beige fat cells in residual subcutaneous WAT …

Pitx2 Dosage-Dependent Changes In Pacemaker Cell State Underlie Sinus Node Dysfunction And Atrial Arrhythmias, Lieve E Van Der Maarel, M Ridwane Mungroo, Otto J Mulleners, Mathilde R Rivaud, Arie O Verkerk, Karel Van Duijvenboden, Freek H T Tiel Groenestege, Jeffrey D Steimle, Lianne Fokkert, Corrie De Gier-De Vries, Mischa Klerk, Arie R Boender, James F Martin, Bjarke Jensen, Gerard J J Boink, Harsha D Devalla, Vincent M Christoffels

Faculty, Staff and Students Publications

Physiologically relevant increases in transcription factor dosage and their role in development and disease remain largely unexplored. Genomic deletions upstream of the Paired-like homeodomain transcription factor gene (PITX2), identified in patients with sinus node dysfunction and atrial fibrillation and modeled in mice (delB), rewire the local epigenetic landscape, increasing PITX2 expression. Here, we demonstrate that pacemaker cardiomyocytes in the embryonic delB sinus node ectopically express PITX2 at physiological dosages in a heterogeneous pattern. The prenatal delB sinus node forms discrete subdomains showing PITX2 dosage-dependent mild or severe loss of pacemaker cardiomyocyte identity. Respective subdomain sizes and severity of sinus node …

Fgf13 Regulates Vgsc-Independent Cardiomyocyte Impulse Propagation Via Cx43 Trafficking, Lala Tanmoy Das, Mattia Malvezzi, Aravind R Gade, Maiko Matsui, Margaret Mckay, Eric Q Wei, Matea J Zelich, Keon Mazdisnian, Jared Kushner, Bi-Xing Chen, Isabella Distefano, Daniel Roybal, Lin Yang, Lisa Stoll, James C Lo, Marian Kalocsay, Fadi G Akar, Steven O Marx, Geoffrey S Pitt

Faculty, Staff and Student Publications

Background: FHF (fibroblast growth factor homologous factor) variants associate with arrhythmias. Although FHFs are best characterized as regulators of voltage-gated sodium channel (VGSC) gating, recent studies suggest broader, non-VGSC-related functions, including regulation of Cx43 (connexin 43) gap junctions and hemichannels, mechanisms that have generally been understudied or disregarded.

Methods: We assessed cardiac conduction and cardiomyocyte action potentials in mice with constitutive cardiac-specific Fgf13 ablation (cFgf13KO) while targeting Cx43 gap junctions and hemichannels pharmacologically. We characterized FGF13 regulation of Cx43 abundance and subcellular distribution. With proximity labeling proteomics, we investigated novel candidate mechanisms underlying FGF13 regulation of Cx43. …

Protein-Protein Interaction–Interfering Peptide Rescues Dysregulated Nmda Receptor Signaling, Robert E. Featherstone, Hongbin Li, Ameet S. Sengar, Karin E. Borgmann-Winter, Olya Melnychenko, Lindsey M. Crown, Ray L. Gifford, Felix Amirfathi, Anamika Banerjee, Aivi Tran, Krishna Parekh, Margaret Heller, Wenyu Zhang, Robert J. Gallop, Adam D. Marc, Pragya Komal, Michael W. Salter, Steven J. Siegel, Chang-Gyu Hahn

Farber Institute for Neuroscience Faculty Papers

The complex and heterogeneous genetic architecture of neuropsychiatric illnesses compels us to look beyond individual risk genes for therapeutic strategies and target the interactive dynamics and convergence of their protein products. A mechanistic substrate for convergence of synaptic neuropsychiatric risk genes are protein-protein interactions (PPIs) in the N-methyl-D-aspartate receptor (NMDAR) complex. NMDAR hypofunction in schizophrenia is associated with hypoactivity of Src kinase, resulting from convergent alterations in PPIs of Src with its partners. Of these, the association of Src with PSD-95, which inhibits the activity of this kinase in the NMDAR complex, is known to be increased in schizophrenia. Here, …

Revealing The Nervous System Requirements Of Alzheimer Disease Risk Genes In Drosophila, Jennifer M Deger, Shabab B Hannan, Mingxue Gu, Colleen E Strohlein, Lindsey D Goodman, Sasidhar Pasupuleti, Zahid Shaik, Liwen Ma, Yarong Li, Jiayang Li, Morgan C Stephens, Michal Tyrlík, Zhandong Liu, Ismael Al-Ramahi, Juan Botas, Chad A Shaw, Oguz Kanca, Hugo J Bellen, Joshua M Shulman

Faculty, Staff and Students Publications

Most Alzheimer disease (AD) susceptibility genes have poorly understood roles in the central nervous system (CNS). To address this gap, we systematically characterized 100 conserved candidate AD risk genes using a cross-species strategy in the fruit fly, Drosophila melanogaster. Genes were prioritized based primarily on human functional genomic evidence. We generated custom loss-of-function alleles for each of the conserved fly orthologs. Most of the genes are expressed in the adult brain, including 24 neuron- and 13 glia-specific expression patterns. Overall, we identify 50 candidate AD risk gene homologs with requirements for CNS structure or function, including 18 whose loss of …

Restoration Of Sfrp3 Preserves The Neural Stem Cell Pool And Spatial Discrimination Ability In A Mouse Model Of Alzheimer's Disease, Chia-Hsuan Fu, Jin Park, Umberto Tosi, Francisco A Blanco, Manuel Silva-Pérez, Kavitha Muralidharan, Jason C You, Minjung Lee, Gabriel S Stephens, Xiaohong Zhang, Yi Zheng, Helen Scharfman, Kimberley F Tolias, Jeannie Chin

Faculty, Staff and Students Publications

Individuals with Alzheimer's disease (AD) have an increased incidence of seizures, which worsen cognitive decline. Using a transgenic mouse model of AD neuropathology that exhibits spontaneous seizures, we previously found that seizure activity stimulates and accelerates depletion of the hippocampal neural stem cell (NSC) pool, which was associated with deficits in neurogenesis-dependent spatial discrimination. However, the precise molecular mechanisms that drive seizure-induced activation and depletion of NSCs are unclear. Here, using mice of both sexes, we performed RNA-sequencing on the hippocampal dentate gyrus and identified differentially expressed regulators of neurogenesis in the Wnt signaling pathway that regulates many aspects of …

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 …

Hif-2-Dependent Regulation Of Pthrp And Paraneoplastic Hypercalcemia In Aggressive Clear-Cell Renal Cell Carcinoma, Arijit Mal, Bingqing Xie, Zane Gray, Charlotte Small, Susmita G Ramanand, Yunpeng Gao, Vanina Toffessi Tcheuyap, Sashi Debnath, Alana Christie, Jeffrey Miyata, Brooklyn Jackson, Hua Zhong, Boning Gao, Jay Lohrey, Naim M Maalouf, Sangeetha M Reddy, John D Minna, Ivan Pedrosa, Xiankai Sun, Ram S Mani, Payal Kapur, James Brugarolas

Faculty, Staff and Student Publications

Renal cell carcinoma (RCC) patients with hypercalcemia (HC) have worse outcomes. HC often involves PTHrP, and the role of HIF-2 is incompletely understood. Leveraging RCC tumorgraft (TG) models of HC, which were characterized by tumor cell autonomous inflamatory/immune signatures, we show that HIF-2 inhibition with PT2399 frequently normalized calcium, downregulated circulating PTHrP and reduced HIF-2 binding to the PTHLH (PTHrP) promoter. Likely contributing to the selective induction of PTHrP in a subset of HIF-2-dependent tumors, the PTHLH locus was generally more accessible in TG(HC). However, PTHLH chromatin accessibility was grossly unaffected by PT2399, unlike elsewhere (including EPO locus in a …

Extracellular Domain Shedding Of Trop2 Activates Egfr Signaling To Drive Prostate Cancer Metastasis, Shiqin Liu, En-Chi Hsu, Merve Aslan, Fernando Garcia-Marques, Michelle Shen, Alifiani B Hartono, Francisco Solano, Kewei Le, Hyeonji Hwang, Chung S Lee, Abel Bermudez, Rosalie Nolley, Donna M Peehl, James D Brooks, Michael A Liss, Sharon J Pitteri, Tanya Stoyanova

Faculty, Staff and Student Publications

UNLABELLED: Metastasis is the main cause of prostate cancer-associated deaths, highlighting the urgent need to determine the mechanisms underlying prostate cancer progression. TROP2 (also known as tumor-associated calcium signal transducer 2) is an oncogenic transmembrane surface protein that is highly expressed in metastatic prostate cancer. Naturally occurring cleavage of TROP2 leads to a release of the TROP2 extracellular domain (TECD) into the extracellular environment. In this study, we identified an important functional role of TECD in prostate cancer metastasis. TECD was detectable in media from prostate cancer cells and serum from patients with clinically significant prostate cancer. Although shed TECD …

Revisiting Soluble Guanylate Cyclase Pharmacology: Additive Potential Of Stimulators And Activators, Alexandra Petraina, Mahmoud H Elbatreek, Christopher T Neullens, Theodora Saridaki, Vu Thao-Vi Dao, Rebecca D Szepanowski, Emil Martin, Wolfgang Sippl, Ana I Casas, Harald H H W Schmidt

Faculty, Staff and Student Publications

Nitric oxide (NO) is a key gasotransmitter that binds to soluble guanylate cyclase (sGC), thereby stimulating cGMP production. Under disease conditions, reactive oxygen species disrupt this signaling by either: (1) scavenging NO, or (2) promoting heme-free, NO-insensitive apo-sGC due to impaired heme incorporation or oxidative damage. To counteract these conditions, two pharmacological approaches have emerged: sGC stimulators, which allosterically enhance sGC sensitivity to low NO levels; and sGC activators, which directly activate apo-sGC (heme-free sGC) by binding to its empty heme pocket, inducing a conformation that mimics NO-bound sGC. Thus, sGC stimulators are thought to target only sGC. Instead, we …

Adrenomedullin Overexpression Protects Mice From Experimental Bronchopulmonary Dysplasia And Associated Pulmonary Hypertension, Shyam Thapa, Poonam Sarkar, M Waleed Gaber, Roberto Barrios, Madhulata Chauhan, Chandrasekhar Yallampalli, Binoy Shivanna

Faculty, Staff and Students Publications

Bronchopulmonary dysplasia (BPD) associated pulmonary hypertension (PH) or BPD-PH is a lung disease of infants with significant morbidity. Adrenomedullin (Adm) is an angiogenic peptide that signals through calcitonin receptor-like receptor (Calcrl) and receptor activity modifying protein 2 (RAMP2). Adm deficiency potentiates hyperoxia-induced experimental BPD-PH in mice; however, whether Adm overexpression can mitigate this lung disease is unclear. Thus, we tested the hypothesis that Adm overexpression attenuates hyperoxia (HO)-induced murine experimental BPD-PH by using a novel transgenic mouse that overexpresses Adm globally (Admhi/hi mice). One-day-old Admhi/hi mice or their wild-type littermates (Adm+/+ mice) were exposed to …

Bypassing Cisplatin Resistance In Nrf2 Hyperactivated Head And Neck Cancer Through Effective Pi3kinase Targeting, Pedram Yadollahi, Kelli A Mccord, Yang Li, Hussam Dayoub, Kalil Saab, Fonma Essien, Sean Hyslop, Emerald Kan, Kazi M Ahmed, Parker R Kirby, Vasanta Putluri, Chandra Shekar R Ambati, Karthik Reddy Kami Reddy, Patricia Castro, Heath D Skinner, Cristian Coarfa, William K Decker, Abdullah A Osman, Rutulkumar Patel, Jeffrey N Myers, Stephen Y Lai, Nagireddy Putluri, Faye M Johnson, Mitchell J Frederick, William H Hudson, Vlad C Sandulache

Faculty, Staff and Students Publications

Background: For patients with head and neck squamous cell carcinoma (HNSCC), failure of definitive radiation combined with cisplatin nearly universally results in death. Although hyperactivation of the Nrf2 pathway can drive radiation and cisplatin resistance along with suppressed anti-tumor immunity, treatment-refractory HNSCC tumors may retain sensitivity to targeted agents secondary to synergistic lethality with other oncogenic drivers (e.g., NOTCH1 mutations).

Methods: Using state of the science mechanistic, metabolomic and spatial transcriptomic approaches combined with preclinical models of HNSCC, we tested whether a novel PI3K inhibitor, gedatolisib, can bypass hyperactivation of the Nrf2 pathway.

Results: The PI3K pathway is activated in …

Method For Generation And Ex Vivo Expansion Of Genetically Edited Mouse Tregs, Yosef Gilad, Adam M Dean, Yan Xia, Sang Jun Han, David M Lonard, Bert W O'Malley

Faculty, Staff and Students Publications

Regulatory T cells (Tregs) play a crucial role in the immune system, and their dysfunction can lead to the development of autoimmune conditions. In cancer, tumors frequently hijack the immunosuppressive function of Tregs to evade immune responses. Due to their central role in key pathological processes, Tregs have gained increasing attention as promising targets for various clinical applications. However, their relative scarcity (∼5% to 10% of CD4+ T cells) and instability presents a technical challenge for research and therapeutic development. In congenic animal models used to investigate autologous cell transfer-based therapies, this challenge is even greater, as Treg donor animals …

Rbm8a Deficiency Causes Hematopoietic Defects By Modulating Wnt/Pcp Signaling, Agnese Kocere, Elena Chiavacci, Charlotte Soneson, Seth T Jacobson, Emma N Harrison, Kevin Manuel Méndez-Acevedo, Jacalyn S Macgowan, Harrison H Wells, Max S Hiltabidle, Azhwar Raghunath, Jordan A Shavit, Daniela Panáková, Margot L K Williams, Mark D Robinson, Christian Mosimann, Alexa Burger

Faculty, Staff and Students Publications

Thrombocytopenia-Absent Radius (TAR) syndrome is a rare congenital condition with reduced platelets, forelimb anomalies, and variable heart and kidney defects. TAR syndrome is caused by mutations in RBM8A/Y14, a component of the exon junction complex. How perturbing a general mRNA-processing factor causes the selective TAR Syndrome phenotypes remains unknown. Here, we connect zebrafish rbm8a perturbation to early hematopoietic defects via attenuated non-canonical Wnt/Planar Cell Polarity (PCP) signaling. In hypomorphic rbm8a zebrafish, we observe a reduction of cd41-positive thrombocytes. rbm8a-mutant zebrafish accumulate mRNAs with retained introns, including non-canonical Wnt/PCP pathway components resulting in convergent extension defects. We found that reduced rbm8a …