Biochemistry, Biophysics, and Structural Biology Commons^™

Crystal Structure Of Mouse Dxo In Complex With The Udp-N-Acetylglucosamine Cap And Molecular Mechanism For The Decapping Reactions, Najeeb Ullah, Selom K. Doamekpor, Liang Tong

Department of Biochemistry and Molecular Biology Faculty Papers

Noncanonical metabolite 5' caps have recently been identified on RNAs, and the DXO/Rai1 family of enzymes can remove these caps in eukaryotes. While the binding modes of NAD, FAD and dephospho-CoA (dpCoA) caps in the active site of mouse DXO have been determined, how DXO recognizes the UDP-glucose (UDP-Glc) and UDP-N-acetylglucosamine (UDP-GlcNAc) caps is not known. In addition, the molecular mechanism by which DXO catalyzes the decapping reactions is still poorly understood, especially the location of the water/hydroxide that attacks the scissile phosphate to initiate the decapping. Here we report the crystal structure of mouse DXO in complex with UDP-GlcNAc …

Maternal Inflammation Alters Nuclear And Mitochondrial Dna Methylation Patterns In Neonatal Brain Monocytes, Andrew Ebenezer, Jonathan Hicks, Brooke Hollander, Alexander Hone, Mona Batish, Robert Akins, Adam Marsh, Elizabeth Wright-Jin

Department of Medicine Faculty Papers

Neonatal hypoxic ischemic encephalopathy (HIE) is a common birth complication that can cause death or lifelong disabling conditions like cerebral palsy, epilepsy, and autism. It is well established that maternal infection and inflammation are significant risk factors for HIE but reasons for this increase in neurological risk to the offspring remain unknown. Inflammation or infection are associated with epigenetic changes and may contribute to the increased risk of neurodevelopmental disability in exposed offspring. Here, we analyzed and compared DNA methylation patterns in brain monocytes isolated from control, maternal immune activation (MIA), and an inflammation sensitized HIE (IS-HIE) CF-1 mouse model …

Polθ Activity Modulates Sensitivity To Standard Therapies In Dnmt3a-Deficient Leukemia, Bac Viet Le, Umeshkumar Vekariya, Monika M. Toma, Margaret Nieborowska-Skorska, Marie-Christine Caron, Malgorzata Gozdecka, Zayd Haydar, Martin Walsh, Jayashri Ghosh, Elaine Vaughan-Williams, Paulina Podszywalow-Bartnicka, Anna-Mariya Kukuyan, Sylwia Ziolkowska, Jessica Atkins, Emir Hadzijusufovic, Gurushankar Chandramouly, Reza Nejati, Katarzyna Piwocka, Richard T. Pomerantz, George S. Vassiliou, Brian J.P. Huntly, Peter Valent, Mariusz Wasik, Alfonso Bellacosa, Jean-Yves Masson, Gaorav P. Gupta, Grant A. Challen, Tomasz Skorski

Department of Biochemistry and Molecular Biology Faculty Papers

Myeloid malignancies carrying somatic DNMT3A mutations (DNMT3Amut) are refractory to standard therapy. DNMT3Amut leukemia cells accumulate toxic DNA double-strand breaks (DSBs) and stalled replication forks, rendering them dependent on DNA damage response (DDR). We report here that DNA polymerase theta (Polθ), a key element in DSB repair by end-joining (Polθ-mediated end-joining [TMEJ]) and in fork restarting, promotes survival and proliferation of DNMT3Amut leukemia cells. Polθ is overexpressed in DNMT3Amut leukemia cells due to abrogation of PARP1 PARylation-dependent UBE2O E3 ligase-mediated ubiquitination and proteasomal degradation of Polθ. In addition, PARP1-mediated recruitment of the SMARCAD1-MSH2/MSH3 repressive complex to DSBs is diminished in …

Defining Rna Oligonucleotides That Reverse Deleterious Phase Transitions Of Rna-Binding Proteins With Prion-Like Domains., Lin Guo, Jacob Mann, Jocelyn Mauna, Katie Copley, Hejia Wang, Jack Rubien, Cristian Bergmann, Jenny Carey, Jessica Merjane, Marilyn Ngo, Jiazhen Xu, Hana Odeh, Jiabei Lin, Bo Lim Lee, Laura Ganser, Emma Robinson, Kevin Kim, Anastasia Murthy, Tapas Paul, Bede Portz, Amanda Gleixner, Zamia Diaz, Ashleigh Smirnov, George Padilla, Ellen Lavorando, Carolann Espy, Yulei Shang, Eric Huang, Alessandra Chesi, Nicolas Fawzi, Sua Myong, Christopher Donnelly, James Shorter

Department of Biochemistry and Molecular Biology Faculty Papers

RNA-binding proteins (RBPs) with prion-like domains (PrLDs), such as FUS and TDP-43, condense into functional liquids, which can transform into pathological fibrils that underpin fatal neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS)/frontotemporal dementia (FTD). Here, we define short RNAs that prevent FUS fibrillization by promoting liquid phases and distinct short RNAs that prevent and reverse FUS condensation and fibrillization. These activities require interactions with multiple RNA-binding domains of FUS and are encoded by RNA sequence, length, and structure. We define a short RNA that dissolves cytoplasmic FUS aggregates, restores nuclear FUS, and mitigates FUS toxicity in optogenetic models and ALS …

Development Of Emerin Mrna Lipid Nanoparticles To Rescue Myogenic Differentiation., Nicholas Marano, Liza Elif Guner, Rachel S Riley, James M Holaska

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Emery-Dreifuss muscular dystrophy 1 (EDMD1) arises from mutations in EMD. Most EDMD1 patients lack detectable emerin expression. They experience symptoms such as skeletal muscle wasting, joint contractures, and cardiac conduction defects. Currently, physicians rely on treating patient symptoms without addressing the underlying cause-lack of functional emerin protein. Thus, there is a need for therapeutic approaches that restore emerin protein expression to improve patient outcomes. One way would be to deliver emerin mRNA or protein directly to affected tissues to restore tissue homeostasis. Here, we evaluated the utility of lipid nanoparticles (LNPs) to deliver emerin mRNA to diseased cells. LNPs …

Genome-Wide Profiling Of Trna Modifications By Induro-Trnaseq Reveals Coordinated Changes, Yuko Nakano, Howard Gamper, Henri Mcguigan, Sunita Maharjan, Jiatong Li, Zhiyi Sun, Erbay Yigit, Sebastian Grünberg, Keerthana Krishnan, Nan-Sheng Li, Joseph Piccirilli, Ralph Kleiner, Nicole Nichols, Brian Gregory, Ya-Ming Hou

Department of Biochemistry and Molecular Biology Faculty Papers

While all native tRNAs undergo extensive post-transcriptional modifications as a mechanism to regulate gene expression, mapping these modifications remains challenging. The critical barrier is the difficulty of readthrough of modifications by reverse transcriptases (RTs). Here we use Induro-a new group-II intron-encoded RT-to map and quantify genome-wide tRNA modifications in Induro-tRNAseq. We show that Induro progressively increases readthrough over time by selectively overcoming RT stops without altering the misincorporation frequency. In a parallel analysis of Induro vs. a related RT, we provide comparative datasets to facilitate the prediction of each modification. We assess tRNA modifications across five human cell lines and …

Modeling Functional Connectivity With Learning And Memory In A Mouse Model Of Alzheimer’S Disease, Lindsay Fadel, Elizabeth Hipskind, Steen E Pedersen, Jonathan Romero, Caitlyn Ortiz, Eric Shin, Md Abul Hassan Samee, Robia G Pautler

Faculty, Staff and Students Publications

Introduction: Functional connectivity (FC) is a metric of how different brain regions interact with each other. Although there have been some studies correlating learning and memory with FC, there have not yet been, to date, studies that use machine learning (ML) to explain how FC changes can be used to explain behavior not only in healthy mice, but also in mouse models of Alzheimer's Disease (AD). Here, we investigated changes in FC and their relationship to learning and memory in a mouse model of AD across disease progression.

Methods: We assessed the APP/PS1 mouse model of AD and wild-type controls …

Reduced K+ Build-Up In T-Tubules Contributes To Resistance Of The Diaphragm To Myotonia, Jessica H. Myers, Kirsten Denman, Chris Dupont, Brent D. Foy, Mark M. Rich

Physics Faculty Publications

Patients with myotonia congenita suffer from slowed muscle relaxation caused by hyperexcitability. The diaphragm is only mildly affected in myotonia congenita; discovery of the mechanism underlying its resistance to myotonia could identify novel therapeutic targets. Intracellular recordings from two mouse models of myotonia congenita revealed the diaphragm had less myotonia than either the extensor digitorum longus (EDL) or the soleus muscles. A mechanism contributing to resistance of the diaphragm to myotonia was reduced depolarization of the interspike membrane potential during repetitive firing of action potentials, a process driven by build-up of K+ in small invaginations of muscle membrane known as …

Pkc-Mediated Phosphorylation Governs The Stability And Function Of Celf1 As A Driver Of Emt In Breast Epithelial Cells, Shebna Massey, Natee Kongchan, Yang Gao, Arindam Chaudhury, Emuejevoke Olokpa, Jason Karch, Anna Malovannaya, Chonghui Cheng, Xiang Zhang, Joel R Neilson

Faculty, Staff and Students Publications

Epithelial to mesenchymal transition (EMT) is believed to be a principal factor contributing to cancer metastasis. The post-transcriptional and post-translational mechanisms underlying EMT are comparatively underexplored. We previously demonstrated that the CELF1 RNA binding protein is necessary and sufficient to drive the EMT of breast epithelial cells, and that the relative protein expression of CELF1 in this context was dictated at the post-translational level. Here, we elucidate the mechanism of this regulation. Mass spectrometric analysis of CELF1 isolated from mesenchymal MCF-10A cells identified multiple sites of serine and threonine phosphorylation on the protein, correlating with the increased stability of this …

Effects Of Cadherin Mediated Contact Normalization On Oncogenic Src Kinase Mediated Gene Expression And Protein Phosphorylation, Rachel E Nicoletto, Cayla J Holdcraft, Ariel C Yin, Edward P Retzbach, Stephanie A Sheehan, Amanda A Greenspan, Christopher M Laugier, Jason Trama, Caifeng Zhao, Haiyan Zheng, Gary S Goldberg

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Nontransformed cells form heterotypic cadherin junctions with adjacent transformed cells to inhibit tumor cell growth and motility. Transformed cells must override this form of growth control, called "contact normalization", to invade and metastasize during cancer progression. Heterocellular cadherin junctions between transformed and nontransformed cells are needed for this process. However, specific mechanisms downstream of cadherin signaling have not been clearly elucidated. Here, we utilized a β-catenin reporter construct to determine if contact normalization affects Wnt signaling in transformed cells. β-catenin driven GFP expression in Src transformed mouse embryonic cells was decreased when cultured with cadherin competent nontransformed cells compared to …

Identification Of An Ionic Mechanism For Erα-Mediated Rapid Excitation In Neurons, Meng Yu, Na Yin, Bing Feng, Peiyu Gao, Kaifan Yu, Hesong Liu, Hailan Liu, Yongxiang Li, Olivia Z Ginnard, Kristine M Conde, Mengjie Wang, Xing Fang, Longlong Tu, Jonathan C Bean, Qingzhuo Liu, Yue Deng, Yuxue Yang, Junying Han, Sanika V Jossy, Megan L Burt, Huey Zhong Wong, Yongjie Yang, Benjamin R Arenkiel, Yang He, Shaodong Guo, Pierre Gourdy, Jean-Francois Arnal, Francoise Lenfant, Zhao Wang, Chunmei Wang, Yanlin He, Yong Xu

Faculty, Staff and Students Publications

The major female ovarian hormone, 17β-estradiol (E2), can alter neuronal excitability within milliseconds to regulate a variety of physiological processes. Estrogen receptor-α (ERα), classically known as a nuclear receptor, exists as a membrane-bound receptor to mediate this rapid action of E2, but the ionic mechanisms remain unclear. Here, we show that a membrane channel protein, chloride intracellular channel protein-1 (Clic1), can physically interact with ERα with a preference to the membrane-bound ERα. Clic1-mediated currents can be enhanced by E2 and reduced by its depletion. In addition, Clic1 currents are required to mediate the E2-induced rapid excitations in multiple brain ERα …

The C-Terminal 4cxxc-Type Zinc Finger Domain Of Cdca7 Recognizes Hemimethylated Dna And Modulates Activities Of Chromatin Remodeling Enzyme Hells, Akeo Shinkai, Hideharu Hashimoto, Chikako Shimura, Hiroaki Fujimoto, Kei Fukuda, Naoki Horikoshi, Masaki Okano, Hitoshi Niwa, Erik W Debler, Hitoshi Kurumizaka, Yoichi Shinkai

Department of Biochemistry and Molecular Biology Faculty Papers

The chromatin-remodeling enzyme helicase lymphoid-specific (HELLS) interacts with cell division cycle-associated 7 (CDCA7) on nucleosomes and is involved in the regulation of DNA methylation in higher organisms. Mutations in these genes cause immunodeficiency, centromeric instability, and facial anomalies (ICF) syndrome, which also results in DNA hypomethylation of satellite repeat regions. We investigated the functional domains of human CDCA7 in HELLS using several mutant CDCA7 proteins. The central region is critical for binding to HELLS, activation of ATPase, and nucleosome sliding activities of HELLS-CDCA7. The N-terminal region tends to inhibit ATPase activity. The C-terminal 4CXXC-type zinc finger domain contributes to CpG …

Vglut2-Based Glutamatergic Signaling In Central Noradrenergic Neurons Is Dispensable For Normal Breathing And Chemosensory Reflexes, Yuan Chang, Savannah Lusk, Andersen Chang, Christopher S Ward, Russell S Ray

Faculty, Staff and Students Publications

Central noradrenergic (NA) neurons are key constituents of the respiratory homeostatic network. NA dysfunction is implicated in several developmental respiratory disorders including Congenital Central Hyperventilation Syndrome (CCHS), Sudden Infant Death Syndrome (SIDS), and Rett Syndrome. The current unchallenged paradigm in the field, supported by multiple studies, is that glutamate co-transmission in subsets of central NA neurons plays a role in breathing control. If true, NA-glutamate co-transmission may also be mechanistically important in respiratory disorders. However, the requirement of NA-derived glutamate in breathing has not been directly tested and the extent of glutamate co-transmission in the central NA system remains uncharacterized. …

Myc Induces Oncogenic Stress Through Rna Decay And Ribonucleotide Catabolism In Breast Cancer, Jitendra K Meena, Jarey H Wang, Nicholas J Neill, Dianne Keough, Nagireddy Putluri, Panagiotis Katsonis, Amanda M Koire, Hyemin Lee, Elizabeth A Bowling, Siddhartha Tyagi, Mayra Orellana, Rocio Dominguez-Vidaña, Heyuan Li, Kenneth Eagle, Charles Danan, Hsiang-Ching Chung, Andrew D Yang, William Wu, Sarah J Kurley, Brian M Ho, Joseph R Zoeller, Calla M Olson, Kristen L Meerbrey, Olivier Lichtarge, Arun Sreekumar, Clifford C Dacso, Luke W Guddat, Dominik Rejman, Dana Hocková, Zlatko Janeba, Lukas M Simon, Charles Y Lin, Monica C Pillon, Thomas F Westbrook

Faculty, Staff and Students Publications

Upregulation of MYC is a hallmark of cancer, wherein MYC drives oncogenic gene expression and elevates total RNA synthesis across cancer cell transcriptomes. Although this transcriptional anabolism fuels cancer growth and survival, the consequences and metabolic stresses induced by excess cellular RNA are poorly understood. Herein, we discover that RNA degradation and downstream ribonucleotide catabolism is a novel mechanism of MYC-induced cancer cell death. Combining genetics and metabolomics, we find that MYC increases RNA decay through the cytoplasmic exosome, resulting in the accumulation of cytotoxic RNA catabolites and reactive oxygen species. Notably, tumor-derived exosome mutations abrogate MYC-induced cell death, suggesting …

Znf397 Deficiency Triggers Tet2-Driven Lineage Plasticity And Ar-Targeted Therapy Resistance In Prostate Cancer, Yaru Xu, Yuqiu Yang, Zhaoning Wang, Martin Sjöström, Yuyin Jiang, Yitao Tang, Siyuan Cheng, Su Deng, Choushi Wang, Julisa Gonzalez, Nickolas A Johnson, Xiang Li, Xiaoling Li, Lauren A Metang, Atreyi Mukherji, Quanhui Xu, Carla R Tirado, Garrett Wainwright, Xinzhe Yu, Spencer Barnes, Mia Hofstad, Yu Chen, Hong Zhu, Ariella B Hanker, Ganesh V Raj, Guanghui Zhu, Housheng H He, Zhao Wang, Carlos L Arteaga, Han Liang, Felix Y Feng, Yunguan Wang, Tao Wang, Ping Mu

Faculty, Staff and Students Publications

Cancer cells exhibit phenotypical plasticity and epigenetic reprogramming that allows them to evade lineage-dependent targeted treatments by adopting lineage plasticity. The underlying mechanisms by which cancer cells exploit the epigenetic regulatory machinery to acquire lineage plasticity and therapy resistance remain poorly understood. We identified zinc finger protein 397 (ZNF397) as a bona fide coactivator of the androgen receptor (AR), essential for the transcriptional program governing AR-driven luminal lineage. ZNF397 deficiency facilitates the transition of cancer cell from an AR-driven luminal lineage to a ten-eleven translocation 2 (TET2)-driven lineage plastic state, ultimately promoting resistance to therapies inhibiting AR signaling. Intriguingly, our …

Scanless Two-Photon Voltage Imaging, Ruth R Sims, Imane Bendifallah, Christiane Grimm, Aysha S Mohamed Lafirdeen, Soledad Domínguez, Chung Yuen Chan, Xiaoyu Lu, Benoît C Forget, François St-Pierre, Eirini Papagiakoumou, Valentina Emiliani

Faculty, Staff and Students Publications

Two-photon voltage imaging has long been heralded as a transformative approach capable of answering many long-standing questions in modern neuroscience. However, exploiting its full potential requires the development of novel imaging approaches well suited to the photophysical properties of genetically encoded voltage indicators. We demonstrate that parallel excitation approaches developed for scanless two-photon photostimulation enable high-SNR two-photon voltage imaging. We use whole-cell patch-clamp electrophysiology to perform a thorough characterization of scanless two-photon voltage imaging using three parallel illumination approaches and lasers with different repetition rates and wavelengths. We demonstrate voltage recordings of high-frequency spike trains and sub-threshold depolarizations from neurons …

Frontotemporal Dementia-Like Disease Progression Elicited By Seeded Aggregation And Spread Of Fus, Sonia Vazquez-Sanchez, Britt Tilkin, Fatima Gasset-Rosa, Sitao Zhang, Diana Piol, Melissa Mcalonis-Downes, Jonathan Artates, Noe Govea-Perez, Yana Verresen, Lin Guo, Don Cleveland, James Shorter, Sandrine Da Cruz

Department of Biochemistry and Molecular Biology Faculty Papers

RNA binding proteins have emerged as central players in the mechanisms of many neurodegenerative diseases. In particular, a proteinopathy of fused in sarcoma (FUS) is present in some instances of familial Amyotrophic lateral sclerosis (ALS) and about 10% of sporadic Frontotemporal lobar degeneration (FTLD). Here we establish that focal injection of sonicated human FUS fibrils into brains of mice in which ALS-linked mutant or wild-type human FUS replaces endogenous mouse FUS is sufficient to induce focal cytoplasmic mislocalization and aggregation of mutant and wild-type FUS which with time spreads to distal regions of the brain. Human FUS fibril-induced FUS aggregation …

Ciliary Tip Actin Dynamics Regulate Photoreceptor Outer Segment Integrity, Roly Megaw, Abigail Moye, Zhixian Zhang, Fay Newton, Fraser Mcphie, Laura C Murphy, Lisa Mckie, Feng He, Melissa K Jungnickel, Alex Von Kriegsheim, Peter A Tennant, Chloe Brotherton, Christine Gurniak, Alecia K Gross, Laura M Machesky, Theodore G Wensel, Pleasantine Mill

Faculty, Staff and Students Publications

As signalling organelles, cilia regulate their G protein-coupled receptor content by ectocytosis, a process requiring localised actin dynamics to alter membrane shape. Photoreceptor outer segments comprise an expanse of folded membranes (discs) at the tip of highly-specialised connecting cilia, into which photosensitive GPCRs are concentrated. Discs are shed and remade daily. Defects in this process, due to mutations, cause retinitis pigmentosa (RP). Whilst fundamental for vision, the mechanism of photoreceptor disc generation is poorly understood. Here, we show membrane deformation required for disc genesis is driven by dynamic actin changes in a process akin to ectocytosis. We show RPGR, a …

An Unexpected Path For Malat1 In Neurons: Trafficking Out Of The Nucleus For Translation, Bradley W Wright, Jeremy E Wilusz

Faculty, Staff and Students Publications

The Malat1 (metastasis-associated lung adenocarcinoma transcript 1) long noncoding RNA is highly and broadly expressed in mammalian tissues, accumulating in the nucleus where it modulates expression and pre-mRNA processing of many protein-coding genes. In this issue of Genes & Development, Xiao and colleagues (doi:10.1101/gad.351557.124) report that a significant fraction of Malat1 transcripts in cultured mouse neurons are surprisingly exported from the nucleus. These transcripts are packaged with Staufen proteins in RNA granules and traffic down the lengths of neurites. They then can be released in a stimulus-dependent manner to be locally translated into a microprotein that alters neuronal gene …

Altered Myocardial Lipid Regulation In Junctophilin-2-Associated Familial Cardiomyopathies, Satadru K Lahiri, Feng Jin, Yue Zhou, Ann P Quick, Carlos F Kramm, Meng C Wang, Xander Ht Wehrens

Faculty, Staff and Students Publications

Myocardial lipid metabolism is critical to normal heart function, whereas altered lipid regulation has been linked to cardiac diseases including cardiomyopathies. Genetic variants in the JPH2 gene can cause hypertrophic cardiomyopathy (HCM) and, in some cases, dilated cardiomyopathy (DCM). In this study, we tested the hypothesis that JPH2 variants identified in patients with HCM and DCM, respectively, cause distinct alterations in myocardial lipid profiles. Echocardiography revealed clinically significant cardiac dysfunction in both knock-in mouse models of cardiomyopathy. Unbiased myocardial lipidomic analysis demonstrated significantly reduced levels of total unsaturated fatty acids, ceramides, and various phospholipids in both mice with HCM and …

Impact Of Obesity And Age On Mouse Corneal Innervation At The Epithelial-Stromal Interface, Justin A Courson, Rolando E Rumbaut, Alan R Burns

Faculty, Staff and Students Publications

PURPOSE: The corneal epithelium is the most highly innervated structure in the body. Previously, we reported a novel event whereby stromal axons fuse with basal epithelial cells, limiting nerve penetration into the epithelium. Although corneal-epithelial nerves undergo changes in sensitivity and distribution throughout life and in response to an obesogenic diet, it is unknown if neuronal-epithelial cell fusion is altered. Here, we sought to determine if neuronal-epithelial cell fusion frequency correlates with obesogenic diet consumption and age.

METHODS: Corneas were collected from C57BL/6 mice and evaluated for neuronal-epithelial cell fusion frequency using serial block-face scanning electron microscopy. To assess the …

Influence Of Rna Circularity On Target Rna-Directed Microrna Degradation, Federico Fuchs Wightman, Jerónimo Lukin, Sebastián A Giusti, Michael Soutschek, Laureano Bragado, Berta Pozzi, María L Pierelli, Paula González, Juan P Fededa, Gerhard Schratt, Rina Fujiwara, Jeremy E Wilusz, Damián Refojo, Manuel De La Mata

Faculty, Staff and Students Publications

A subset of circular RNAs (circRNAs) and linear RNAs have been proposed to 'sponge' or block microRNA activity. Additionally, certain RNAs induce microRNA destruction through the process of Target RNA-Directed MicroRNA Degradation (TDMD), but whether both linear and circular transcripts are equivalent in driving TDMD is unknown. Here, we studied whether circular/linear topology of endogenous and artificial RNA targets affects TDMD. Consistent with previous knowledge that Cdr1as (ciRS-7) circular RNA protects miR-7 from Cyrano-mediated TDMD, we demonstrate that depletion of Cdr1as reduces miR-7 abundance. In contrast, overexpression of an artificial linear version of Cdr1as drives miR-7 degradation. Using plasmids that …

Akap12 Upregulation Associates With Pde8a To Accelerate Cardiac Dysfunction, Hanan Qasim, Mehrdad Rajaei, Ying Xu, Arfaxad Reyes-Alcaraz, Hala Y Abdelnasser, M David Stewart, Satadru K Lahiri, Xander H T Wehrens, Bradley K Mcconnell

Faculty, Staff and Students Publications

BACKGROUND: In heart failure, signaling downstream the β2-adrenergic receptor is critical. Sympathetic stimulation of β2-adrenergic receptor alters cAMP (cyclic adenosine 3',5'-monophosphate) and triggers PKA (protein kinase A)-dependent phosphorylation of proteins that regulate cardiac function. cAMP levels are regulated in part by PDEs (phosphodiesterases). Several AKAPs (A kinase anchoring proteins) regulate cardiac function and are proposed as targets for precise pharmacology. AKAP12 is expressed in the heart and has been reported to directly bind β2-adrenergic receptor, PKA, and PDE4D. However, its roles in cardiac function are unclear.

METHODS: cAMP accumulation in real time downstream of the β2-adrenergic receptor was detected for …

Differentially Disrupted Spinal Cord And Muscle Energy Metabolism In Spinal And Bulbar Muscular Atrophy, Danielle Debartolo, Frederick Arnold, Y Liu, Elana Molotsky, Hsin-Yao Tang, Diane Merry

Department of Biochemistry and Molecular Biology Faculty Papers

Prior studies showed that polyglutamine-expanded androgen receptor (AR) is aberrantly acetylated and that deacetylation of the mutant AR by overexpression of nicotinamide adenine dinucleotide-dependent (NAD+-dependent) sirtuin 1 is protective in cell models of spinal and bulbar muscular atrophy (SBMA). Based on these observations and reduced NAD+ in muscles of SBMA mouse models, we tested the therapeutic potential of NAD+ restoration in vivo by treating postsymptomatic transgenic SBMA mice with the NAD+ precursor nicotinamide riboside (NR). NR supplementation failed to alter disease progression and had no effect on increasing NAD+ or ATP content in muscle, despite producing a modest increase of …

Centriole And Transition Zone Structures In Photoreceptor Cilia Revealed By Cryo-Electron Tomography, Zhixian Zhang, Abigail R Moye, Feng He, Muyuan Chen, Melina A Agosto, Theodore G Wensel

Faculty, Staff and Students Publications

Primary cilia mediate sensory signaling in multiple organisms and cell types but have structures adapted for specific roles. Structural defects in them lead to devastating diseases known as ciliopathies in humans. Key to their functions are structures at their base: the basal body, the transition zone, the "Y-shaped links," and the "ciliary necklace." We have used cryo-electron tomography with subtomogram averaging and conventional transmission electron microscopy to elucidate the structures associated with the basal region of the "connecting cilia" of rod outer segments in mouse retina. The longitudinal variations in microtubule (MT) structures and the lumenal scaffold complexes connecting them …

In Vivo Dynamic Volumetric Imaging Of Mouse Testis And Epididymis With Optical Coherence Tomography†, Kohei Umezu, Guzel R Musina, Irina V Larina

Faculty, Staff and Students Publications

The implementation of live imaging in reproductive research is crucial for studying the physiological dynamics. Sperm transport is a highly dynamic process regulated by tubular contractions and luminal flows within the male reproductive tract. However, due to the lack of imaging techniques to capture these dynamics in vivo, there is little information on the physiological and biomechanical regulation of sperm transport through the male reproductive tract. Here, we present a functional in vivo imaging approach using optical coherence tomography, enabling live, label-free, depth-resolved, three-dimensional, high-resolution visualization of the mouse testis and epididymis. With this approach, we spatiotemporally captured tubular contractility …

Endothelial Cells Adopt A Pro-Reparative Immune Responsive Signature During Cardiac Injury, Hali Long, Jeffrey D Steimle, Francisco Jose Grisanti Canozo, Jong Hwan Kim, Xiao Li, Yuka Morikawa, Minjun Park, Diwakar Turaga, Iki Adachi, Joshua D Wythe, Md Abul Hassan Samee, James F Martin

Faculty, Staff and Students Publications

Modulation of the heart’s immune microenvironment is crucial for recovery after ischemic events such as myocardial infarction (MI). Endothelial cells (ECs) can have immune regulatory functions; however, interactions between ECs and the immune environment in the heart after MI remain poorly understood. We identified an EC-specific IFN responsive and immune regulatory gene signature in adult and pediatric heart failure (HF) tissues. Single-cell transcriptomic analysis of murine hearts subjected to MI uncovered an EC population (IFN-ECs) with immunologic gene signatures similar to those in human HF. IFN-ECs were enriched in regenerative-stage mouse hearts and expressed genes encoding immune responsive transcription factors …

Β2-Glycoprotein I Promotes The Clearance Of Circulating Mitochondria, Swapan Kumar Dasgupta, Jahnavi Gollamudi, Stefanie Rivera, Ross A Poche, Rolando E Rumbaut, Perumal Thiagarajan

Faculty, Staff and Students Publications

β2-glycoprotein I (β2-Gp1) is a cardiolipin-binding plasma glycoprotein. It is evolutionarily conserved from invertebrates, and cardiolipin-bound β2-Gp1 is a major target of antiphospholipid antibodies seen in autoimmune disorders. Cardiolipin is almost exclusively present in mitochondria, and mitochondria are present in circulating blood. We show that β2-Gp1 binds to cell-free mitochondria (CFM) in the circulation and promotes its phagocytosis by macrophages at physiological plasma concentrations. Exogenous CFM had a short circulation time of less than 10 minutes in mice. Following infusion of CFM, β2-Gp1-deficient mice had significantly higher levels of transfused mitochondria at 5 minutes (9.9 ± 6.4 pg/ml versus 4.0 …

Inhibition Of Src-3 As A Potential Therapeutic Strategy For Aggressive Mantle Cell Lymphoma, Imani Bijou, Yang Liu, Dong Lu, Jianwei Chen, Shelby Sloan, Lapo Alinari, David M Lonard, Bert W O'Malley, Michael Wang, Jin Wang

Faculty, Staff and Students Publications

Mantle cell lymphoma (MCL) has a poor prognosis and high relapse rates despite current therapies, necessitating novel treatment regimens. Inhibition of SRC-3 show effectiveness in vivo and in vitro in other B cell lymphomas. Additionally, previous studies have shown that SRC-3 is highly expressed in the lymph nodes of B cell non-Hodgkin's lymphoma patients, suggesting SRC-3 may play a role in the progression of B cell lymphoma. This study aimed to investigate novel SRC-3 inhibitors, SI-10 and SI-12, in mantle cell lymphoma. The cytotoxic effects of SI-10 and SI-12 were evaluated in vitro and demonstrated dose-dependent cytotoxicity in a panel …

Targeting Eif4a Triggers An Interferon Response To Synergize With Chemotherapy And Suppress Triple-Negative Breast Cancer, Na Zhao, Elena B Kabotyanski, Alexander B Saltzman, Anna Malovannaya, Xueying Yuan, Lucas C Reineke, Nadia Lieu, Yang Gao, Diego A Pedroza, Sebastian J Calderon, Alex J Smith, Clark Hamor, Kazem Safari, Sara Savage, Bing Zhang, Jianling Zhou, Luisa M Solis, Susan G Hilsenbeck, Cheng Fan, Charles M Perou, Jeffrey M Rosen

Faculty, Staff and Students Publications

Protein synthesis is frequently dysregulated in cancer and selective inhibition of mRNA translation represents an attractive cancer therapy. Here, we show that therapeutically targeting the RNA helicase eIF4A with zotatifin, the first-in-class eIF4A inhibitor, exerts pleiotropic effects on both tumor cells and the tumor immune microenvironment in a diverse cohort of syngeneic triple-negative breast cancer (TNBC) mouse models. Zotatifin not only suppresses tumor cell proliferation but also directly repolarizes macrophages toward an M1-like phenotype and inhibits neutrophil infiltration, which sensitizes tumors to immune checkpoint blockade. Mechanistic studies revealed that zotatifin reprograms the tumor translational landscape, inhibits the translation of Sox4 …