Medicine and Health Sciences Commons^™

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 …

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 …

Intracellular Acinetobacter Baumannii Acts As A Transient Reservoir In Lung Infection Via A "Persist And Resist" Strategy, Manon Janet-Maitre, Gisela Di Venanzio, Clay D Jackson-Litteken, Nichollas E Scott, Mario F Feldman

2020-Current year OA Pubs

Although considered primarily extracellular,

Intracranial Injection Of Genetically Modified, Mosquito Non-Transmissible Zika Virus: Safety In Primates And Ramifications For Brain Tumor Therapy, Alec J Hirsch, Amanda De Andrade Costa, Emilie Russler-Germain, Ashwani Kesarwani, Yuping Li, Michael S Diamond, Milan G Chheda, Et Al.

2020-Current year OA Pubs

Glioblastomas (GBMs) are incurable brain tumors. Zika virus (ZIKV) has specificity in killing GBM stem cells, which drive treatment resistance. In mouse models of GBM, ZIKV also generates an anti-tumor inflammatory response and prolongs survival. To support clinical development and address safety concerns for intra-tumoral treatment, we assessed the effects of injection of an immune-sensitized ZIKV (Δ10 3'-UTR ZIKV), which cannot be transmitted by mosquitos, into non-tumor-bearing rhesus macaque brains. After injection, the primates showed no clinical signs of illness. Histologically, as expected, ZIKV infection elicited mild inflammation, which resolved within 2 weeks. No infectious virus was detected in the …

A Proteogenomic Gene Signature Defines Prognostic Subgroups Highlighting Pi3k/Akt/Mtor Signaling Pathway As A Therapeutic Vulnerability In Myeloid Malignancies, Fan He, Shuyang Lin, Bei Gao, Varun Ramesh, Alexander B Kim, Tim Kong, Daniel A C Fisher, Christopher T Letson, Molly Brakhane, Mary Fulbright, Yanbo Yu, Marco Sardiello, Jorge Di Paola, Stephen M Sykes, Stephen T Oh

2020-Current year OA Pubs

INTRODUCTION: Myeloid malignancies, including acute myeloid leukemia (AML) and myeloproliferative neoplasms (MPN), exhibit overlapping pathophysiology. Chronic MPNs can transform into secondary AML (sAML), which is associated with poor prognosis and limited treatment options. However, the process and prognostic significance of leukemic transformation remain incompletely understood.

METHOD: Through a two-sample bidirectional Mendelian randomization (MR) analysis, we showed that genetic liability to MPN significantly predicts the risk of developing AML, establishing MPN as the precursor to leukemia. To identify mediators of this risk, we integrated population-level plasma proteomics data, identifying 55 proteins associated with MPN. Upon integrative analysis with the BEAT-AML cohort, …

Wdfy4-Dependent Cross-Presentation Proceeds Via A Vacuolar Antigen-Processing Route, J Luke Postoak, Alyssa Koch, Sicong Shan, Ray A Ohara, Suin Jo, Jing Chen, Pritesh Desai, Feiya Ou, Magdalena Kraft, Michael S Diamond, Sunkyung Kim, Theresa L Murphy, Kenneth M Murphy

2020-Current year OA Pubs

The intracellular processing route used by type I conventional dendritic cells (cDC1) for cross-presentation of viral- or tumor-associated antigens remains controversial. One model proposes that captured antigens exit from damaged phagolysosomes and enter the cytosol, where they are processed for presentation by MHC class I molecules (MHC-I). This model relies on proteasomal degradation and TAP-dependent peptide transport into the endoplasmic reticulum (ER) for loading by the peptide loading complex (PLC). An alternative model proposes a vesicular route in which captured antigens are retained and processed within an endocytic compartment. A compelling argument favoring the cytosolic model is the dramatic loss …

The Inferred Functional Connectome Underlying Circadian Synchronization In The Mouse Suprachiasmatic Nucleus, K L Nikhil, Bharat Singhal, Daniel Granados-Fuentes, Jr-Shin Li, István Z Kiss, Erik D Herzog

2020-Current year OA Pubs

Circadian rhythms in mammals arise from the spatiotemporal synchronization of ~20,000 neuronal clocks in the suprachiasmatic nucleus (SCN). Although anatomical, molecular, and genetic approaches have revealed diverse SCN cell types, how network-level wiring enables their synchronization remains unclear. To overcome the challenges of inferring functional connectivity from fixed tissue, we developed Mutual Information & Transfer Entropy (MITE), an information-theoretic framework to infer directed cell-cell connections with high fidelity from long-term live-cell imaging. Recording and analyzing 3,290 h of clock gene expression from 8,261 SCN neurons across 17 mice, we uncovered a highly conserved, sparse SCN network organized into two asymmetrically …

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 …

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 …

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 …

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. …

Loss Of Mfap5 And Its Effect On Skin Homeostasis And Wound Healing, Chen Han, Heidi Yuan, Timothy J Koh, Lin Chen, Robert P Mecham, Luisa A Dipietro

2020-Current year OA Pubs

MFAP5, also known as microfibrillar-associated glycoprotein-2 (MAGP2), may influence parameters of skin wound healing related to scar formation. To further elucidate its role in skin wound healing, we assessed skin wound repair in Mfap5

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 …

Biophysical Simulation Enables Segmentation And Nervous System Atlas Mapping For Image First Spatial Omics, Lina Mohammed Ali, Aldrin Kay Yuen Yim, Emanuel Gerbi, Thien Nguyen, Nicholas Tu, Faith Ikede, Remi Sampaleanu, Diana Grigore, Jason Waligorski, Colin Kremitzki, Liya Yuan, Wendy Dong, Robi Mitra, Jeffrey Milbrandt, William Buchser

2020-Current year OA Pubs

Spatial omics (SO) produces high-definition mapping of subcellular molecules within tissue samples. Mapping transcripts to anatomical regions requires segmentation, but this remains challenging in tissue cross-sections with tubular structures like axons in peripheral nerve or spinal cord. Neural networks could address misidentification but are hindered by the need for extensive human annotations. We present SiDoLa-NS (Simulate, Don't Label-Nervous System), an image-driven (top-down) approach to SO analysis in the nervous system. We utilize biophysical properties of tissue architectures to design synthetic images of tissue samples, eliminating reliance on manual annotation and enabling scalable training data generation. With synthetic samples, we trained …

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 …

Sex-Specific Angiogenic Responses In Endothelial Cells-Role Of The Pluripotency Factor Oct4, Junchul Shin, Junyoung Hong, Iuliia Molokotina, Irene Krukovets, Ellin Kim, Svyatoslav Tkachenko, Eugene Podrez, Tatiana V Byzova, Olga A Cherepanova

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The study investigates the sex-specific effects of the pluripotency factor OCT4 deficiency in endothelial cells (ECs) on angiogenesis. OCT4 is known for its role in embryonic stem cells, but we recently found that it plays a protective role in ECs during atherosclerosis. Herein, we utilized cultured mouse aortic ECs (MAECs) and several in vivo models, including skin wounding, melanoma tumor implantation, and hindlimb ischemia, to explore the role of OCT4 in angiogenesis in both male and female mice. Our findings revealed significant sexual dimorphism in wild type mice, along with sex differences in responses to OCT4 deficiency across all three …

Concurrent Tb And Hiv Therapies Control Tb Reactivation During Co-Infection But Not Chronic Immune Activation, Riti Sharan, Yi Zou, Bindu Singh, Vinay Shivanna, Edward J Dick, Shannan Hall-Ursone, Xi Luo, Guanlin Guo, Shabaana A Khader, Xavier Alvarez, Jyothi Rengarajan, Zhao Lai, Smriti Mehra, Hulin Wu, Deepak Kaushal

Faculty, Staff and Student Publications

Most HIV-negative individuals exposed to Mycobacterium tuberculosis (Mtb) control infection as latent TB infection (LTBI), but HIV co-infection greatly increases progression to tuberculosis (TB), the leading cause of death in people living with HIV (PLHIV). Although combination antiretroviral therapy (cART) reduces LTBI reactivation, immune control of Mtb is not fully restored, as shown by persistent TB incidence in PLHIV on cART. In macaques, skewed pulmonary effector memory CD4⁺ T-cell (TEM) responses and new TB lesions persist despite cART. We hypothesize that concurrent anti-TB therapy with cART would improve bacterial control and immune restoration compared to cART alone. Using …

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, …

Conservation Of Cis-Regulatory Codes Over Half A Billion Years Of Evolution, Yohey Ogawa, Yu Liu, Connie A Myers, Ala Morshedian, Gordon L Fain, Alapakkam P Sampath, Joseph C Corbo

2020-Current year OA Pubs

Identifying homologous cell types across species is essential for understanding cell type evolution. The retina is ideal for comparative analysis because its six major cell classes have persisted since the origin of vertebrates more than half a billion years ago. Here, we show that the retina's conserved cellular architecture is mirrored by deep conservation of the cis-regulatory codes that govern gene expression. Through single-cell chromatin accessibility analysis of lamprey, fish, bird, and mammalian retinas, we demonstrate cross-species conservation of cis-regulatory codes in all retinal cell classes despite extensive turnover of cis-regulatory regions. Conservation manifests as clustering of high-affinity transcription factor …

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 …

Delayed Delivery Of Antibiotics By Ultrasound-Mediated Rupture Of Polylactic Acid Pockets: In Vitro And In Vivo Studies, Selin Isguven Billmyer, Priscilla Machado, Ryan Tomlinson, Lauren J. Delaney, Ji-Bin Liu, Alexander H Harris, Eric Mclaughlin, Noreen J. Hickok, Flemming Forsberg

Department of Radiology Faculty Papers

Surgical site infections are a devastating complication of instrumented orthopaedic surgery, particularly in the spine. Bacterial biofilms, once formed on the implant surfaces, exhibit antibiotic tolerance and immune escape, which lead to treatment challenges. Up to 9% of instrumented spine surgeries result in infection, despite the use of systemic antibiotics and local, powdered antibiotics for prophylaxis. The bacteria that survive the initial prophylaxis may be susceptible to a second, high dose of antibiotic prophylaxis prior to establishing at the site. Hence, we designed a local drug delivery system consisting of polylactic acid (PLA) film pockets that can be noninvasively triggered …

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 …

The Breakdown Of Neurovascular Barriers: Molecular Mechanisms Of Tight Junction Dysfunction, Sowmya Shree Gopal, Mandeep Kaur, Sophie Lanzkron, Amit K. Srivastava

Department of Medicine Faculty Papers

The central nervous system (CNS) relies on tightly regulated barriers to maintain homeostasis and protect neural tissue from blood-borne toxins, pathogens, and inflammatory mediators. Tight junctions (TJs) are critical components of the blood-brain barrier (BBB) and blood-spinal cord barrier (BSCB), forming selective paracellular seals that regulate molecular trafficking. These structures comprise transmembrane proteins and cytoplasmic scaffolding proteins, which anchor TJs to the actin cytoskeleton. The spatial organization and function of TJs are dynamically regulated by calcium-dependent signaling, phosphorylation events, and G-protein-mediated pathways, which govern their assembly, disassembly, and response to physiological and pathological stimuli. The integrity of TJ complexes is …

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 …

Glycoside Hydrolase-Mediated Glucomannan Catabolism In Segatella Copri, A Target Of Microbiota-Directed Foods For Malnourished Children, Cyrus Zhou, Matthew C Hibberd, Evan M Lee, Suzanne Henrissat, Marie A Crane, Jiye Cheng, Michael J Barratt, Jeffrey I Gordon, Et Al.

2020-Current year OA Pubs

Evidence is emerging that perturbed postnatal gut microbiota development is causally related to childhood undernutrition. Clinical trials in undernourished Bangladeshi children found that a polysaccharide-rich, microbiota-directed complementary food (MDCF-2) designed to repair this perturbation produced superior ponderal and linear growth compared to a standard ready-to-use supplementary food. Subsequent analyses disclosed several candidate bioactive polysaccharides in the MDCF and their bacterial targets, notably strains of

Liver Injury In A Preclinical Model Of Short Bowel Syndrome Is Associated With Impaired Autophagy, Daniel M Alligood, Alex Park, Kerry Swanson, Naima Pyarali, Evan Mayse, David M Alvarado, Xiuli Liu, Jae-Sung Kim, Nicholas O Davidson, Deborah C Rubin, Jun Guo, Brad W Warner

2020-Current year OA Pubs

Critical for cellular maintenance and repair, autophagy recycles damaged or redundant cellular components. Dysregulated autophagy is associated with progressive cellular injury in various liver pathologies. However, the role of autophagy in intestinal failure-associated liver disease has not previously been investigated. Using a preclinical murine model of short bowel syndrome, we explored the role of autophagy impairment at early and late time points. Regardless of sex, small bowel resected (SBR) mice demonstrated significant liver injury compared to sham controls, exhibiting elevated serum transaminases, altered liver histology, and increased mRNA expression of endoplasmic reticulum stress marker (Ddit3) and oxidative stress marker (Nqo1). …

Myocardial Lipin1 Protects The Heart Against Ischemic Injury By Preserving Lipid Homeostasis, Jiaxi Guo, Brian N. Finck, Et Al.

2020-Current year OA Pubs

Impaired cardiac lipid metabolism has been reported to cause heart failure. Lipin1, a multifunctional protein, is a phosphatidate phosphatase that generates diacylglycerol from phosphatidic acid and a transcriptional cofactor that regulates lipid metabolism-related gene expression. Here, we investigated the roles of lipin1 in cardiac remodeling after myocardial infarction (MI). The expression levels of lipin1 significantly decreased in cardiomyocytes of the human failing heart and murine ischemic myocardium. Cardiomyocyte-specific Lpin1 knockout (cKO) mice showed left ventricle enlargement and reduced fractional shortening after MI, compared with control mice. This was accompanied by elevated cardiac fibrosis, accumulation of reactive oxygen species, and increased …

Insm1 Governs A Neuronal Progenitor State That Drives Glioblastoma In A Human Stem Cell Model, Patrick A Desouza, Matthew Ishahak, Xuan Qu, Colin Mccornack, Devi Annamalai, Diane D Mao, Rajanikanth Vangipurapu, Yiwei Fu, Alexandre T Vessoni, Ryan T Cleary, Rowland H Han, Punn Augsornworawat, Timothy Woodiwiss, Darby Agovino, Braxton Sizemore, Jessica Kline, Maryam Borhani-Haghighi, Hao Chen, Sangami Pugazenthi, Hiroko Yano, Ting Wang, Luis F Z Batista, Jeffrey R Millman, Albert H Kim

2020-Current year OA Pubs

Glioblastoma is a lethal brain cancer marked by functional plasticity driven by tumor cell-intrinsic mutations and their interplay with developmental programs. To investigate how canonical glioblastoma mutations promote functional plasticity, we have developed an isogenic human neural stem cell (NSC) model of glioblastoma by sequential addition of TERT promoter, TP53, and PDGFRA point mutations. TP53 loss-of-function increases TERT expression during serial mutagenesis, but only triple mutant NSCs reliably form lethal brain tumors in vivo that recapitulate glioblastoma. Tumor cell evolution triggers stress-related metabolic changes and transitions toward a neuronal progenitor network driven by transcription factor INSM1. INSM1 is highly expressed …

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 …

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 …