Biochemistry, Biophysics, and Structural Biology Commons^™

Secretogranin Iii Stringently Regulates Pathological But Not Physiological Angiogenesis In Oxygen-Induced Retinopathy, Chang Dai, Prabuddha Waduge, Liyang Ji, Chengchi Huang, Ye He, Hong Tian, Elizabeth Zuniga-Sanchez, Amit Bhatt, Iok-Hou Pang, Guanfang Su, Keith A Webster, Wei Li

Faculty, Staff and Students Publications

Conventional angiogenic factors, such as vascular endothelial growth factor (VEGF), regulate both pathological and physiological angiogenesis indiscriminately, and their inhibitors may elicit adverse side effects. Secretogranin III (Scg3) was recently reported to be a diabetes-restricted VEGF-independent angiogenic factor, but the disease selectivity of Scg3 in retinopathy of prematurity (ROP), a retinal disease in preterm infants with concurrent pathological and physiological angiogenesis, was not defined. Here, using oxygen-induced retinopathy (OIR) mice, a surrogate model of ROP, we quantified an exclusive binding of Scg3 to diseased versus healthy developing neovessels that contrasted sharply with the ubiquitous binding of VEGF. Functional immunohistochemistry visualized …

Mutations In Hcfc1 And Ronin Result In An Inborn Error Of Cobalamin Metabolism And Ribosomopathy, Tiffany Chern, Annita Achilleos, Xuefei Tong, Matthew C Hill, Alexander B Saltzman, Lucas C Reineke, Arindam Chaudhury, Swapan K Dasgupta, Yushi Redhead, David Watkins, Joel R Neilson, Perumal Thiagarajan, Jeremy B A Green, Anna Malovannaya, James F Martin, David S Rosenblatt, Ross A Poché

Faculty, Staff and Students Publications

Combined methylmalonic acidemia and homocystinuria (cblC) is the most common inborn error of intracellular cobalamin metabolism and due to mutations in Methylmalonic Aciduria type C and Homocystinuria (MMACHC). Recently, mutations in the transcriptional regulators HCFC1 and RONIN (THAP11) were shown to result in cellular phenocopies of cblC. Since HCFC1/RONIN jointly regulate MMACHC, patients with mutations in these factors suffer from reduced MMACHC expression and exhibit a cblC-like disease. However, additional de-regulated genes and the resulting pathophysiology is unknown. Therefore, we have generated mouse models of this disease. In addition to exhibiting loss of Mmachc, metabolic perturbations, and developmental defects previously …

Aav5 Delivery Of Crispr-Cas9 Supports Effective Genome Editing In Mouse Lung Airway, Shun-Qing Liang, Christopher J Walkey, Alexa E Martinez, Qin Su, Mary E Dickinson, Dan Wang, William R Lagor, Jason D Heaney, Guangping Gao, Wen Xue

Faculty, Staff and Students Publications

Genome editing in the lung has the potential to provide long-term expression of therapeutic protein to treat lung genetic diseases. Yet efficient delivery of CRISPR to the lung remains a challenge. The NIH Somatic Cell Genome Editing (SCGE) Consortium is developing safe and effective methods for genome editing in disease tissues. Methods developed by consortium members are independently validated by the SCGE small animal testing center to establish rigor and reproducibility. We have developed and validated a dual adeno-associated virus (AAV) CRISPR platform that supports effective editing of a lox-stop-lox-Tomato reporter in mouse lung airway. After intratracheal injection of the …

Autophagosomes Fuse To Phagosomes And Facilitate The Degradation Of Apoptotic Cells In Caenorhabditis Elegans, Omar Peña-Ramos, Lucia Chiao, Xianghua Liu, Xiaomeng Yu, Tianyou Yao, Henry He, Zheng Zhou

Faculty, Staff and Students Publications

Autophagosomes are double-membrane intracellular vesicles that degrade protein aggregates, intracellular organelles, and other cellular components. During the development of the nematode Caenorhabditis elegans, many somatic and germ cells undergo apoptosis. These cells are engulfed and degraded by their neighboring cells. We discovered a novel role of autophagosomes in facilitating the degradation of apoptotic cells using a real-time imaging technique. Specifically, the double-membrane autophagosomes in engulfing cells are recruited to the surfaces of phagosomes containing apoptotic cells and subsequently fuse to phagosomes, allowing the inner vesicle to enter the phagosomal lumen. Mutants defective in the production of autophagosomes display significant …

The Role Of Action Potential Changes In Depolarization-Induced Failure Of Excitation Contraction Coupling In Mouse Skeletal Muscle, Xueyong Wang, Murad Nawaz, Chris Dupont, Jessica H. Myers, Steve R.A. Burke, Roger A. Bannister, Brent D. Foy, Andrew A. Voss, Mark M. Rich

Physics Faculty Publications

Excitation-contraction coupling (ECC) is the process by which electrical excitation of muscle is converted into force generation. Depolarization of skeletal muscle resting potential contributes to failure of ECC in diseases such as periodic paralysis, intensive care unit acquired weakness and possibly fatigue of muscle during vigorous exercise. When extracellular K+ is raised to depolarize the resting potential, failure of ECC occurs suddenly, over a narrow range of resting potentials. Simultaneous imaging of Ca2+ transients and recording of action potentials (APs) demonstrated failure to generate Ca2+ transients when APs peaked at potentials more negative than –30mV. An AP property that closely …

Transient Ascaris Suum Larval Migration Induces Intractable Chronic Pulmonary Disease And Anemia In Mice, Yifan Wu, Evan Li, Morgan Knight, Grace Adeniyi-Ipadeola, Li-Zhen Song, Alan R Burns, Ana Clara Gazzinelli-Guimaraes, Ricardo Fujiwara, Maria Elena Bottazzi, Jill E Weatherhead

Faculty, Staff and Students Publications

Ascariasis is one of the most common infections in the world and associated with significant global morbidity. Ascaris larval migration through the host's lungs is essential for larval development but leads to an exaggerated type-2 host immune response manifesting clinically as acute allergic airway disease. However, whether Ascaris larval migration can subsequently lead to chronic lung diseases remains unknown. Here, we demonstrate that a single episode of Ascaris larval migration through the host lungs induces a chronic pulmonary syndrome of type-2 inflammatory pathology and emphysema accompanied by pulmonary hemorrhage and chronic anemia in a mouse model. Our results reveal that …

Hematopoiesis Under Telomere Attrition At The Single-Cell Resolution, Natthakan Thongon, Feiyang Ma, Andrea Santoni, Matteo Marchesini, Elena Fiorini, Ashley Rose, Vera Adema, Irene Ganan-Gomez, Emma M Groarke, Fernanda Gutierrez-Rodrigues, Shuaitong Chen, Pamela Lockyer, Sarah Schneider, Carlos Bueso-Ramos, Guillermo Montalban-Bravo, Caleb A Class, Kelly A Soltysiak, Matteo Pellegrini, Ergun Sahin, Alison A Bertuch, Courtney D Dinardo, Guillermo Garcia-Manero, Neal S Young, Karen Dwyer, Simona Colla

Faculty, Staff and Students Publications

The molecular mechanisms that drive hematopoietic stem cell functional decline under conditions of telomere shortening are not completely understood. In light of recent advances in single-cell technologies, we sought to redefine the transcriptional and epigenetic landscape of mouse and human hematopoietic stem cells under telomere attrition, as induced by pathogenic germline variants in telomerase complex genes. Here, we show that telomere attrition maintains hematopoietic stem cells under persistent metabolic activation and differentiation towards the megakaryocytic lineage through the cell-intrinsic upregulation of the innate immune signaling response, which directly compromises hematopoietic stem cells' self-renewal capabilities and eventually leads to their exhaustion. …

Ckb Inhibits Epithelial-Mesenchymal Transition And Prostate Cancer Progression By Sequestering And Inhibiting Akt Activation, Zheng Wang, Mohit Hulsurkar, Lijuan Zhuo, Jinbang Xu, Han Yang, Samira Naderinezhad, Lin Wang, Guoliang Zhang, Nanping Ai, Linna Li, Jeffrey T Chang, Songlin Zhang, Ladan Fazli, Chad J Creighton, Fang Bai, Michael M Ittmann, Martin E Gleave, Wenliang Li

Faculty, Staff and Students Publications

Epithelial-mesenchymal transition (EMT) contributes to tumor invasion, metastasis and drug resistance. AKT activation is key in a number of cellular processes. While many positive regulators for either EMT or AKT activation have been reported, few negative regulators are established. Through kinase cDNA screen, we identified brain-type creatine kinase (CKB or BCK) as a potent suppressor for both. As a ubiquitously expressed kinase in normal tissues, CKB is significantly downregulated in several solid cancer types. Lower CKB expression is significantly associated with worse prognosis. Phenotypically, CKB overexpression suppresses, while its silencing promotes, EMT and cell migration, xenograft tumor growth and metastasis …

Super-Resolution Microscopy Reveals Photoreceptor-Specific Subciliary Location And Function Of Ciliopathy-Associated Protein Cep290, Valencia L Potter, Abigail R Moye, Michael A Robichaux, Theodore G Wensel

Faculty, Staff and Students Publications

Mutations in the cilium-associated protein CEP290 cause retinal degeneration as part of multiorgan ciliopathies or as retina-specific diseases. The precise location and the functional roles of CEP290 within cilia and, specifically, the connecting cilia (CC) of photoreceptors, remain unclear. We used super-resolution fluorescence microscopy and electron microscopy to localize CEP290 in the CC and in the primary cilia of cultured cells with subdiffraction resolution and to determine effects of CEP290 deficiency in 3 mutant models. Radially, CEP290 localizes in close proximity to the microtubule doublets in the region between the doublets and the ciliary membrane. Longitudinally, it is distributed throughout …

Norovirus Protease Structure And Antivirals Development, Boyang Zhao, Liya Hu, Yongcheng Song, Ketki Patil, Sasirekha Ramani, Robert L Atmar, Mary K Estes, B V Venkataram Prasad

Faculty, Staff and Students Publications

Human norovirus (HuNoV) infection is a global health and economic burden. Currently, there are no licensed HuNoV vaccines or antiviral drugs available. The protease encoded by the HuNoV genome plays a critical role in virus replication by cleaving the polyprotein and is an excellent target for developing small-molecule inhibitors. The current strategy for developing HuNoV protease inhibitors is by targeting the enzyme's active site and designing inhibitors that bind to the substrate-binding pockets located near the active site. However, subtle differential conformational flexibility in response to the different substrates in the polyprotein and structural differences in the active site and …

Cellular Regeneration As A Potential Strategy To Treat Cardiac Conduction Disorders, Satadru K Lahiri, Mohit M Hulsurkar, Xander Ht Wehrens

Faculty, Staff and Students Publications

Loss of atrioventricular conduction system (AVCS) cells due to either inherited or acquired deficits leads to conduction diseases, which can deteriorate into fatal cardiac arrhythmias and sudden death. In this issue of the JCI, Wang et al. constructed a mouse model of atrioventricular block (AVB) by inducing AVCS cell-specific injury using the Cx30.2 enhancer to drive expression of diphtheria toxin fragment A. AVCS cell ablation in adult mice led to irreversible AVB. jkjkIn contrast, AVCS cell injury in neonatal mice was followed by spontaneous recovery in a subset of mice, revealing a limited postnatal time window during which the regeneration …

Neuron-Specific Mitochondrial Oxidative Stress Results In Epilepsy, Glucose Dysregulation And A Striking Astrocyte Response, Ruth E Fulton, Jennifer N Pearson-Smith, Christopher Q Huynh, Timothy Fabisiak, Li-Ping Liang, Stefanos Aivazidis, Brigit A High, Georgia Buscaglia, Timothy Corrigan, Robert Valdez, Takahiko Shimizu, Manisha N Patel

Faculty, Staff and Students Publications

Mitochondrial superoxide (O2.−) production is implicated in aging, neurodegenerative disease, and most recently epilepsy. Yet the specific contribution of neuronal O2.− to these phenomena is unclear. Here, we selectively deleted superoxide dismutase-2 (SOD2) in neuronal basic helix-loop-helix transcription factor (NEX)-expressing cells restricting deletion to a subset of excitatory principle neurons primarily in the forebrain (cortex and hippocampus). This resulted in nSOD2 KO mice that lived into adulthood (2-3 months) with epilepsy, selective loss of neurons, metabolic rewiring and a marked mitohormetic gene response. Surprisingly, expression of an astrocytic gene, glial fibrillary acidic protein (GFAP) was significantly increased relative …

Determining Effective Drug Concentrations For Selection And Counterselection Genetics In Drosophila Melanogaster, Nick Matinyan, Yezabel Gonzalez, Herman A Dierick, Koen J T Venken

Faculty, Staff and Students Publications

We recently integrated into fly genetics a set of four selection and two counterselection markers and their corresponding drugs that can be used individually or in combination. These markers eliminate the need to visually screen progeny. Before using these markers in new genetic backgrounds, effective selection/counterselection concentrations should be established for each marker/drug combination. This protocol describes how to set up, perform, and analyze a drug titration curve to determine the effective selection/counterselection drug concentrations for their corresponding markers. For complete details on the use and execution of this protocol, please refer to Matinyan et al., 2021.

Multiplexed Drug-Based Selection And Counterselection Genetic Manipulations In Drosophila, Nick Matinyan, Mansi S Karkhanis, Yezabel Gonzalez, Antrix Jain, Alexander Saltzman, Anna Malovannaya, Alejandro Sarrion-Perdigones, Herman A Dierick, Koen J T Venken

Faculty, Staff and Students Publications

The power of Drosophila melanogaster as a model system relies on tractable germline genetic manipulations. Despite Drosophila's expansive genetics toolbox, such manipulations are still accomplished one change at a time and depend predominantly on phenotypic screening. We describe a drug-based genetic platform consisting of four selection and two counterselection markers, eliminating the need to screen for modified progeny. These markers work reliably individually or in combination to produce specific genetic outcomes. We demonstrate three example applications of multiplexed drug-based genetics by generating (1) transgenic animals, expressing both components of binary overexpression systems in a single transgenesis step; (2) dual selectable …

Dna-Encoded Chemistry Technology Yields Expedient Access To Sars-Cov-2m Pro Inhibitors, Srinivas Chamakuri, Shuo Lu, Melek Nihan Ucisik, Kurt M Bohren, Ying-Chu Chen, Huang-Chi Du, John C Faver, Ravikumar Jimmidi, Feng Li, Jian-Yuan Li, Pranavanand Nyshadham, Stephen S Palmer, Jeroen Pollet, Xuan Qin, Shannon E Ronca, Banumathi Sankaran, Kiran L Sharma, Zhi Tan, Leroy Versteeg, Zhifeng Yu, Martin M Matzuk, Timothy Palzkill, Damian W Young

Faculty, Staff and Students Publications

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has killed more than 4 million humans globally, but there is no bona fide Food and Drug Administration–approved drug-like molecule to impede the COVID-19 pandemic. The sluggish pace of traditional therapeutic discovery is poorly suited to producing targeted treatments against rapidly evolving viruses. Here, we used an affinity-based screen of 4 billion DNA-encoded molecules en masse to identify a potent class of virus-specific inhibitors of the SARS-CoV-2 main protease (Mpro) without extensive and time-consuming medicinal chemistry. CDD-1714, the initial three-building-block screening hit (molecular weight [MW] = 542.5 g/mol), was a potent inhibitor (inhibition …

Dna-Encoded Chemistry Technology Yields Expedient Access To Sars-Cov-2m Pro Inhibitors, Srinivas Chamakuri, Shuo Lu, Melek Nihan Ucisik, Kurt M Bohren, Ying-Chu Chen, Huang-Chi Du, John C Faver, Ravikumar Jimmidi, Feng Li, Jian-Yuan Li, Pranavanand Nyshadham, Stephen S Palmer, Jeroen Pollet, Xuan Qin, Shannon E Ronca, Banumathi Sankaran, Kiran L Sharma, Zhi Tan, Leroy Versteeg, Zhifeng Yu, Martin M Matzuk, Timothy Palzkill, Damian W Young

Faculty, Staff and Students Publications

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has killed more than 4 million humans globally, but there is no bona fide Food and Drug Administration–approved drug-like molecule to impede the COVID-19 pandemic. The sluggish pace of traditional therapeutic discovery is poorly suited to producing targeted treatments against rapidly evolving viruses. Here, we used an affinity-based screen of 4 billion DNA-encoded molecules en masse to identify a potent class of virus-specific inhibitors of the SARS-CoV-2 main protease (Mpro) without extensive and time-consuming medicinal chemistry. CDD-1714, the initial three-building-block screening hit (molecular weight [MW] = 542.5 g/mol), was a potent inhibitor (inhibition …

Zfta-Rela Dictates Oncogenic Transcriptional Programs To Drive Aggressive Supratentorial Ependymoma, Amir Arabzade, Yanhua Zhao, Srinidhi Varadharajan, Hsiao-Chi Chen, Selin Jessa, Bryan Rivas, Austin J Stuckert, Minerva Solis, Alisha Kardian, Dana Tlais, Brian J Golbourn, Ann-Catherine J Stanton, Yuen San Chan, Calla Olson, Kristen L Karlin, Kathleen Kong, Robert Kupp, Baoli Hu, Sarah G Injac, Madeline Ngo, Peter R Wang, Luz A De León, Felix Sahm, Daisuke Kawauchi, Stefan M Pfister, Charles Y Lin, H Courtney Hodges, Irtisha Singh, Thomas F Westbrook, Murali M Chintagumpala, Susan M Blaney, Donald W Parsons, Kristian W Pajtler, Sameer Agnihotri, Richard J Gilbertson, Joanna Yi, Nada Jabado, Claudia L Kleinman, Kelsey C Bertrand, Benjamin Deneen, Stephen C Mack

Faculty, Staff and Students Publications

Over 60% of supratentorial (ST) ependymomas harbor a ZFTA-RELA (ZRfus) gene fusion (formerly C11orf95-RELA). To study the biology of ZRfus, we developed an autochthonous mouse tumor model using in utero electroporation (IUE) of the embryonic mouse brain. Integrative epigenomic and transcriptomic mapping was performed on IUE driven ZRfus tumors by CUT&RUN, ChIP, ATAC, and RNA sequencing and compared to human ZRfus driven ependymoma. In addition to direct canonical NF-κB pathway activation, ZRfus dictates a neoplastic transcriptional program and binds to thousands of unique sites across the genome that are enriched with Plagl family transcription factor (TF) motifs. ZRfus activates …

Structure And Dynamics Of Photoreceptor Sensory Cilia, Theodore G Wensel, Valencia L Potter, Abigail Moye, Zhixian Zhang, Michael A Robichaux

Faculty, Staff and Students Publications

The rod and cone photoreceptor cells of the vertebrate retina have highly specialized structures that enable them to carry out their function of light detection over a broad range of illumination intensities with optimized spatial and temporal resolution. Most prominent are their unusually large sensory cilia, consisting of outer segments packed with photosensitive disc membranes, a connecting cilium with many features reminiscent of the primary cilium transition zone, and a pair of centrioles forming a basal body which serves as the platform upon which the ciliary axoneme is assembled. These structures form a highway through which an enormous flux of …

Pgc1Α Is Required For The Renoprotective Effect Of Lncrna Tug1 In Vivo And Links Tug1 With Urea Cycle Metabolites, Li Li, Jianyin Long, Koki Mise, Daniel L Galvan, Paul A Overbeek, Lin Tan, Shwetha V Kumar, Wai Kin Chan, Phillip L Lorenzi, Benny H Chang, Farhad R Danesh

Faculty, Staff and Students Publications

lncRNA taurine-upregulated gene 1 (Tug1) is a promising therapeutic target in the progression of diabetic nephropathy (DN), but the molecular basis of its protection remains poorly understood. Here, we generate a triple-mutant diabetic mouse model coupled with metabolomic profiling data to interrogate whether Tug1 interaction with peroxisome proliferator-activated receptor gamma coactivator 1α (PGC1α) is required for mitochondrial remodeling and progression of DN in vivo. We find that, compared with diabetic conditional deletion of Pgc1α in podocytes alone (db/db; Pgc1αPod-f/f), diabetic Pgc1α knockout combined with podocyte-specific Tug1 overexpression (db/db; TugPodTg; Pgc1αPod-f/f) reverses the protective phenotype of …

A Noncoding Rna Modulator Potentiates Phenylalanine Metabolism In Mice, Yajuan Li, Zhi Tan, Yaohua Zhang, Zhao Zhang, Qingsong Hu, Ke Liang, Yao Jun, Youqiong Ye, Yi-Chuan Li, Chunlai Li, Lan Liao, Jianming Xu, Zhen Xing, Yinghong Pan, Sujash S Chatterjee, Tina K Nguyen, Heidi Hsiao, Sergey D Egranov, Nagireddy Putluri, Cristian Coarfa, David H Hawke, Preethi H Gunaratne, Kuang-Lei Tsai, Leng Han, Mien-Chie Hung, George A Calin, Fares Namour, Jean-Louis Guéant, Ania C Muntau, Nenad Blau, V Reid Sutton, Manuel Schiff, François Feillet, Shuxing Zhang, Chunru Lin, Liuqing Yang

Faculty, Staff and Students Publications

The functional role of long noncoding RNAs (lncRNAs) in inherited metabolic disorders, including phenylketonuria (PKU), is unknown. We demonstrated that the mouse lncRNA Pair and human HULC associate with phenylalanine hydroxylase (PAH). Pair-knockout mice exhibited excessive blood phenylalanine, musty odor, hypopigmentation, growth retardation, and progressive neurological symptoms including seizures, which faithfully models human PKU. HULC depletion led to reduced PAH enzymatic activities in human induced pluripotent stem cell (hiPSC)-differentiated hepatocytes. Mechanistically, HULC modulated the enzymatic activities of PAH by facilitating PAH-substrate and PAH-cofactor interactions. To develop a therapeutic strategy for restoring liver lncRNAs, we designed GalNAc-tagged lncRNA mimics that …

Cd148 Deficiency In Fibroblasts Promotes The Development Of Pulmonary Fibrosis, Konstantin Tsoyi, Xiaoliang Liang, Giulia De Rossi, Stefan W Ryter, Kevin Xiong, Sarah G Chu, Xiaoli Liu, Bonna Ith, Lindsay J Celada, Freddy Romero, Matthew J Robertson, Anthony J Esposito, Sergio Poli, Souheil El-Chemaly, Mark A Perrella, Yuanyuan Shi, James Whiteford, Ivan O Rosas

Faculty, Staff and Students Publications

Rationale: CD148/PTRJ (receptor-like protein tyrosine phosphatase η) exerts antifibrotic effects in experimental pulmonary fibrosis via interactions with its ligand syndecan-2; however, the role of CD148 in human pulmonary fibrosis remains incompletely characterized.

Objectives: We investigated the role of CD148 in the profibrotic phenotype of fibroblasts in idiopathic pulmonary fibrosis (IPF).

Methods: Conditional CD148 fibroblast-specific knockout mice were generated and exposed to bleomycin and then assessed for pulmonary fibrosis. Lung fibroblasts (mouse lung and human IPF lung), and precision-cut lung slices from human patients with IPF were isolated and subjected to experimental treatments. A CD148-activating 18-aa mimetic peptide (SDC2-pep) derived from …

Neurovascular Regulation In Diabetic Retinopathy And Emerging Therapies, Liyang Ji, Hong Tian, Keith A Webster, Wei Li

Faculty, Staff and Students Publications

Diabetic retinopathy (DR) is the leading cause of vision loss in working adults in developed countries. The disease traditionally classified as a microvascular complication of diabetes is now widely recognized as a neurovascular disorder resulting from disruption of the retinal neurovascular unit (NVU). The NVU comprising retinal neurons, glia and vascular cells coordinately regulates blood flow, vascular density and permeability to maintain homeostasis. Disturbance of the NVU during DR can lead to vision-threatening clinical manifestations. A limited number of signaling pathways have been identified for intercellular communication within the NVU, including vascular endothelial growth factor (VEGF), the master switch for …

A Synthetic Circuit For Buffering Gene Dosage Variation Between Individual Mammalian Cell, Jin Yang, Jihwan Lee, Michelle A Land, Shujuan Lai, Oleg A Igoshin, François St-Pierre

Faculty, Staff and Students Publications

Precise control of gene expression is critical for biological research and biotechnology. However, transient plasmid transfections in mammalian cells produce a wide distribution of copy numbers per cell, and consequently, high expression heterogeneity. Here, we report plasmid-based synthetic circuits - Equalizers - that buffer copy-number variation at the single-cell level. Equalizers couple a transcriptional negative feedback loop with post-transcriptional incoherent feedforward control. Computational modeling suggests that the combination of these two topologies enables Equalizers to operate over a wide range of plasmid copy numbers. We demonstrate experimentally that Equalizers outperform other gene dosage compensation topologies and produce as low cell-to-cell …

Gene Therapy Knockdown Of Hippo Signaling Induces Cardiomyocyte Renewal In Pigs After Myocardial Infarction, Shijie Liu, Ke Li, Leonardo Wagner Florencio, Li Tang, Todd R Heallen, John P Leach, Yidan Wang, Francisco Grisanti, James T Willerson, Emerson C Perin, Sui Zhang, James F Martin

Faculty, Staff and Students Publications

Human heart failure, a leading cause of death worldwide, is a prominent example of a chronic disease that may result from poor cell renewal. The Hippo signaling pathway is an inhibitory kinase cascade that represses adult heart muscle cell (cardiomyocyte) proliferation and renewal after myocardial infarction in genetically modified mice. Here, we investigated an adeno-associated virus 9 (AAV9)–based gene therapy to locally knock down the Hippo pathway gene Salvador (Sav) in border zone cardiomyocytes in a pig model of ischemia/reperfusion-induced myocardial infarction. Two weeks after myocardial infarction, when pigs had left ventricular systolic dysfunction, we administered AAV9-Sav …

Pathological Mechanisms Of Vacuolar Aggregate Myopathy Arising From A Casq1 Mutation, Amy D Hanna, Chang Seok Lee, Lyle Babcock, Hui Wang, Joseph Recio, Susan L Hamilton

Faculty, Staff and Students Publications

Mice with a mutation (D244G, DG) in calsequestrin 1 (CASQ1), analogous to a human mutation in CASQ1 associated with a delayed onset human myopathy (vacuolar aggregate myopathy), display a progressive myopathy characterized by decreased activity, decreased ability of fast twitch muscles to generate force and low body weight after one year of age. The DG mutation causes CASQ1 to partially dissociate from the junctional sarcoplasmic reticulum (SR) and accumulate in the endoplasmic reticulum (ER). Decreased junctional CASQ1 reduces SR Ca

The Small Gtpase Rab-35 Facilitates The Initiation Of Phagosome Maturation And Acts As A Robustness Factor For Apoptotic Cell Clearance, Ryan Haley, Zheng Zhou

Faculty, Staff and Students Publications

We recently identified the novel function of the small GTPase RAB-35 in apoptotic cell clearance in Caenorhabditis elegans, a process in which dying cells are engulfed and degraded inside phagosomes. We have found that RAB-35 functions in two separate steps of cell corpse clearance, cell corpse recognition and the initiation of phagosome maturation. During the latter process, RAB-35 facilitates the removal of phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2) from the membranes of nascent phagosomes and the simultaneous production of phosphatidylinositol-3-P (PI(3)P) on these same membranes, a process that we have coined the PI(4,5)P2 to PI(3)P shift. RAB-35 also promotes the recruitment of the …

Restructuring The Gut Microbiota By Intermittent Fasting Lowers Blood Pressure, Huanan Shi, Bojun Zhang, Taylor Abo-Hamzy, James W Nelson, Chandra Shekar R Ambati, Joseph F Petrosino, Robert M Bryan, David J Durgan

Faculty, Staff and Students Publications

Rationale:

In recent years, it has been demonstrated that a pathological change in the gut microbiota, termed gut dysbiosis, can be an underlying factor for the development of hypertension. Prevention of this dysbiosis can attenuate or abolish hypertension. Translational mechanisms to prevent gut dysbiosis as well as understanding of the mechanisms linking gut dysbiosis to hypertension are lacking.

Objective:

We first examined the efficacy of intermittent fasting (IF) in altering the gut microbiota and lowering blood pressure (BP). Next, we utilized a multi-omics approach to examine microbial influenced metabolites that may serve as the link between the gut microbiota and …

Mitochondrial Transfer From Mesenchymal Stem Cells Improves Neuronal Metabolism After Oxidant Injury In Vitro: The Role Of Miro1, Nancy Tseng, Scott C Lambie, Christopher Q Huynh, Bridget Sanford, Manisha Patel, Paco S Herson, D Ryan Ormond

Faculty, Staff and Students Publications

Stroke-induced cerebral ischemia is a major cause of death and disability. The disruption of blood flow results in neuronal and glial cell death leading to brain injury. Reperfusion restores oxygen to the affected tissue, but can also cause damage through an enhanced oxidative stress and inflammatory response. This study examines mitochondrial transfer from MSC to neurons and the role it plays in neuronal preservation after oxidant injury. We observed the transfer of mitochondria from MSC to mouse neurons in vitro following hydrogen peroxide exposure. The observed transfer was dependent on cell-to-cell contact and led to increased neuronal survival and improved …

Serial Block-Face Scanning Electron Microscopy (Sbf-Sem) Of Biological Tissue Samples, Justin A Courson, Paul T Landry, Thao Do, Eric Spehlmann, Pascal J Lafontant, Nimesh Patel, Rolando E Rumbaut, Alan R Burns

Faculty, Staff and Students Publications

Serial block-face scanning electron microscopy (SBF-SEM) allows for the collection of hundreds to thousands of serially-registered ultrastructural images, offering an unprecedented three-dimensional view of tissue microanatomy. While SBF-SEM has seen an exponential increase in use in recent years, technical aspects such as proper tissue preparation and imaging parameters are paramount for the success of this imaging modality. This imaging system benefits from the automated nature of the device, allowing one to leave the microscope unattended during the imaging process, with the automated collection of hundreds of images possible in a single day. However, without appropriate tissue preparation cellular ultrastructure can …

Synthesis, Structure-Activity Relationships, And Antiviral Activity Of Allosteric Inhibitors Of Flavivirus Ns2b-Ns3 Protease, Shenyou Nie, Yuan Yao, Fangrui Wu, Xiaowei Wu, Jidong Zhao, Yuanda Hua, Jingyu Wu, Tong Huo, Yi-Lun Lin, Alexander R Kneubehl, Megan B Vogt, Josephine Ferreon, Rebecca Rico-Hesse, Yongcheng Song

Faculty, Staff and Students Publications

Flaviviruses, including Zika, dengue and West Nile virus, are important human pathogens. The highly conserved NS2B-NS3 protease of Flavivirus is essential for viral replication and therefore a promising drug target. Through compound screen followed by medicinal chemistry studies, a novel series of 2,5,6-trisubstituted pyrazine compounds are found to be potent, allosteric inhibitors of Zika virus protease (ZVpro) with IC50 values as low as 130 nM. Their structure-activity relationships are discussed. The ZVpro inhibitors also inhibit homologous proteases of dengue and West Nile virus and their inhibitory activities are correlated. The most potent compounds 47 and 103 potently inhibited Zika virus …