Medicine and Health Sciences Commons^™

Cofilin-1-Induced Actin Reorganization In Stored Platelets, Swapan K Dasgupta, Perumal Thiagarajan

Faculty, Staff and Students Publications

BACKGROUND: During platelet storage, there are extensive changes in cytoskeleton and phosphatidylserine exposure. The intrinsic mitochondrial pathway of apoptosis, activated in stored platelets, is a major mediator these changes. Cofilin-1 is an effector of actin reorganization. We examined the effect of cofilin-1 deficiency on cytoskeleton and phosphatidylserine exposure during storage and following activation of apoptosis.

METHODS AND RESULTS: We assessed actin filaments by Alexa-647-phalloidin and phosphatidylserine exposure by fluorescein isothiocyanate-lactadherin by fluorescence microscopy. In fresh platelets, actin filaments are distributed in the subcortical region, and they do not express phosphatidylserine in the outer surface. In stored platelets, there is retraction …

Nr2f1 Heterozygous Knockout Mice Recapitulate Neurological Phenotypes Of Bosch-Boonstra-Schaaf Optic Atrophy Syndrome And Show Impaired Hippocampal Synaptic Plasticity, Chun-An Chen, Wei Wang, Steen E Pedersen, Ayush Raman, Michelle L Seymour, Fernanda R Ruiz, Anping Xia, Meike E Van Der Heijden, Li Wang, Jiani Yin, Joanna Lopez, Megan E Rech, Richard A Lewis, Samuel M Wu, Zhandong Liu, Fred A Pereira, Robia G Pautler, Huda Y Zoghbi, Christian P Schaaf

Faculty, Staff and Students Publications

Bosch-Boonstra-Schaaf optic atrophy syndrome (BBSOAS) has been identified as an autosomal-dominant disorder characterized by a complex neurological phenotype, with high prevalence of intellectual disability and optic nerve atrophy/hypoplasia. The syndrome is caused by loss-of-function mutations in NR2F1, which encodes a highly conserved nuclear receptor that serves as a transcriptional regulator. Previous investigations to understand the protein's role in neurodevelopment have mostly used mouse models with constitutive and tissue-specific homozygous knockout of Nr2f1. In order to represent the human disease more accurately, which is caused by heterozygous NR2F1 mutations, we investigated a heterozygous knockout mouse model and found that this model …

Discovery Of A Bacterial Peptide As A Modulator Of Glp-1 And Metabolic Disease, Catherine Tomaro-Duchesneau, Stephanie L Levalley, Daniel Roeth, Liang Sun, Frank T Horrigan, Markus Kalkum, Joseph M Hyser, Robert A Britton

Faculty, Staff and Students Publications

Early work in rodents highlighted the gut microbiota's importance in metabolic disease, including Type II Diabetes Mellitus (T2DM) and obesity. Glucagon-like peptide-1 (GLP-1), an incretin secreted by L-cells lining the gastrointestinal epithelium, has important functions: promoting insulin secretion, insulin sensitivity, and β-cell mass, while inhibiting gastric emptying and appetite. We set out to identify microbial strains with GLP-1 stimulatory activity as potential metabolic disease therapeutics. Over 1500 human-derived strains were isolated from healthy individuals and screened for GLP-1 modulation by incubating bacterial cell-free supernatants with NCI H716 L-cells. Approximately 45 strains capable of increasing GLP-1 were discovered. All GLP-1 positive …

Cell Type Composition And Circuit Organization Of Clonally Related Excitatory Neurons In The Juvenile Mouse Neocortex, Cathryn R Cadwell, Federico Scala, Paul G Fahey, Dmitry Kobak, Shalaka Mulherkar, Fabian H Sinz, Stelios Papadopoulos, Zheng H Tan, Per Johnsson, Leonard Hartmanis, Shuang Li, Ronald J Cotton, Kimberley F Tolias, Rickard Sandberg, Philipp Berens, Xiaolong Jiang, Andreas Savas Tolias

Faculty, Staff and Students Publications

Clones of excitatory neurons derived from a common progenitor have been proposed to serve as elementary information processing modules in the neocortex. To characterize the cell types and circuit diagram of clonally related excitatory neurons, we performed multi-cell patch clamp recordings and Patch-seq on neurons derived from Nestin-positive progenitors labeled by tamoxifen induction at embryonic day 10.5. The resulting clones are derived from two radial glia on average, span cortical layers 2–6, and are composed of a random sampling of transcriptomic cell types. We find an interaction between shared lineage and connection type: related neurons are more likely to …

Methyl-Sensing Nuclear Receptor Liver Receptor Homolog-1 Regulates Mitochondrial Function In Mouse Hepatocytes, Sungwoo Choi, Bingning Dong, Chih-Chun Janet Lin, Mi Jeong Heo, Kang Ho Kim, Zhen Sun, Martin Wagner, Nagireddy Putluri, Jae Myoung Suh, Meng C Wang, David D Moore

Faculty, Staff and Students Publications

Liver receptor homologue-1 (LRH-1; NR5A2) is a nuclear receptor that regulates metabolic homeostasis in the liver. Previous studies identified phosphatidylcholines as potential endogenous agonist ligands for LRH-1. In the liver, distinct subsets of phosphatidylcholine species are generated by two different pathways: choline addition to phosphatidic acid via the Kennedy pathway, or trimethylation of phosphatidylethanolamine via Phosphatidylethanolamine N-methyl Transferase (PEMT). Here we report that a PEMT - LRH-1 pathway specifically couples methyl metabolism and mitochondrial activities in hepatocytes. We show that the loss of Lrh-1 reduces mitochondrial number, basal respiration, beta-oxidation and ATP production in hepatocytes, and decreases expression of mitochondrial …

Immune Checkpoint Modulation Enhances Hiv-1 Antibody Induction., Todd Bradley, Masayuki Kuraoka, Chen-Hao Yeh, Ming Tian, Huan Chen, Derek W Cain, Xuejun Chen, Cheng Cheng, Ali H Ellebedy, Robert Parks, Maggie Barr, Laura L. Sutherland, Richard M. Scearce, Cindy M. Bowman, Hilary Bouton-Verville, Sampa Santra, Kevin Wiehe, Mark G. Lewis, Ane Ogbe, Persephone Borrow, David Montefiori, Mattia Bonsignori, M Anthony Moody, Laurent Verkoczy, Kevin O. Saunders, Rafi Ahmed, John R. Mascola, Garnett Kelsoe, Frederick W. Alt, Barton F. Haynes

Manuscripts, Articles, Book Chapters and Other Papers

Eliciting protective titers of HIV-1 broadly neutralizing antibodies (bnAbs) is a goal of HIV-1 vaccine development, but current vaccine strategies have yet to induce bnAbs in humans. Many bnAbs isolated from HIV-1-infected individuals are encoded by immunoglobulin gene rearrangments with infrequent naive B cell precursors and with unusual genetic features that may be subject to host regulatory control. Here, we administer antibodies targeting immune cell regulatory receptors CTLA-4, PD-1 or OX40 along with HIV envelope (Env) vaccines to rhesus macaques and bnAb immunoglobulin knock-in (KI) mice expressing diverse precursors of CD4 binding site HIV-1 bnAbs. CTLA-4 blockade augments HIV-1 Env …

Synthetic And Genomic Regulatory Elements Reveal Aspects Of Cis-Regulatory Grammar In Mouse Embryonic Stem Cells, Dana M King, Clarice Kit Yee Hong, James L Shepherdson, David M Granas, Brett B Maricque, Barak A Cohen

2020-Current year OA Pubs

In embryonic stem cells (ESCs), a core transcription factor (TF) network establishes the gene expression program necessary for pluripotency. To address how interactions between four key TFs contribute to

What We Can Learn From A Genetic Rodent Model About Autism., Dorit Möhrle, Marta Fernández, Olga Peñagarikano, Andreas Frick, Brian Allman, Susanne Schmid

Anatomy and Cell Biology Publications

Autism spectrum disorders (ASD) are complex neurodevelopmental disorders that are caused by genetic and/or environmental impacts, often probably by the interaction of both. They are characterised by deficits in social communication and interaction and by restricted and repetitive behaviours and interests from early childhood on, causing significant impairment. While it is clear that no animal model captures the full complexity of ASD in humans, genetic models are extremely useful for studying specific symptoms associated with ASD and the underlying cellular and molecular mechanisms. In this review we summarize the behavioral paradigms used in rodents to model ASD symptoms as they …

Insights Image For "Evidence Of Increased Hypoxia Signalling In Fetal Liver From Maternal Nutrient Restriction In Mice"., Bethany N Radford, Victor K M Han

Paediatrics Publications

No abstract provided.

Evidence Of Increased Hypoxia Signaling In Fetal Liver From Maternal Nutrient Restriction In Mice., Bethany N Radford, Victor K M Han

Paediatrics Publications

BACKGROUND: Intrauterine growth restriction (IUGR) is a pregnancy condition where fetal growth is reduced, and offspring from IUGR pregnancies are at increased risk for type II diabetes as adults. The liver is susceptible to fetal undernutrition experienced by IUGR infants and animal models of growth restriction. This study aimed to examine hepatic expression changes in a maternal nutrient restriction (MNR) mouse model of IUGR to understand fetal adaptations that influence adult metabolism.

METHODS: Liver samples of male offspring from MNR (70% of ad libitum starting at E6.5) or control pregnancies were obtained at E18.5 and differential expression was assessed by …

Impaired Meningeal Lymphatic Vessel Development Worsens Stroke Outcome, Pavel Yanev, Katherine Poinsatte, Devon Hominick, Noor Khurana, Kielen R. Zuurbier, Marcus Berndt, Erik J. Plautz, Michael T. Dellinger, Ann M. Stowe

Neurology Faculty Publications

The discovery of meningeal lymphatic vessels (LVs) has sparked interest in identifying their role in diseases of the central nervous system. Similar to peripheral LVs, meningeal LVs depend on vascular endothelial growth factor receptor-3 (VEGFR3) signaling for development. Here we characterize the effect of stroke on meningeal LVs, and the impact of meningeal lymphatic hypoplasia on post-stroke outcomes. We show that photothrombosis (PT), but not transient middle cerebral artery occlusion (tMCAo), induces meningeal lymphangiogenesis in young male C57Bl/J6 mice. We also show that Vegfr3^wt/mut mice develop significantly fewer meningeal LVs than Vegfr3^wt/wt mice. Again, meningeal lymphangiogenesis occurs in …

Periodontal Inflammation: Integrating Genes And Dysbiosis, Shaoping Zhang, Ning Yu, Roger M Arce

Faculty, Staff and Student Publications

Biofilm bacteria co-evolve and reach a symbiosis with the host on the gingival surface. The disruption of the homeostatic relationship between plaque bacteria and the host can initiate and promote periodontal disease progression. Recent advances in sequencing technologies allow researchers to profile disease-associated microbial communities and quantify microbial metabolic activities and host transcriptional responses. In addition to confirming the findings from previous studies, new putative pathogens and novel genes that have not previously been associated with periodontitis, emerge. For example, multiple studies have reported that Synergistetes bacteria are associated with periodontitis. Genes involved in epithelial barrier defense were downregulated in …

Hypothalamic Orexin And Mechanistic Target Of Rapamycin Activation Mediate Sleep Dysfunction In A Mouse Model Of Tuberous Sclerosis Complex, Bo Zhang, Dongjun Guo, Lirong Han, Nicholas Rensing, Akiko Satoh, Michael Wong

2020-Current year OA Pubs

Tuberous sclerosis complex (TSC) is a genetic disease related to hyperactivation of the mechanistic target of rapamycin (mTOR) pathway and manifested by neurological symptoms, such as epilepsy and sleep disorders. The pathophysiology of sleep dysfunction is poorly understood and is likely multifactorial, but may involve intrinsic biological regulators in the brain. Here, we characterized a mouse model of sleep disorders in TSC and investigated mechanisms of sleep dysfunction in this conditional knockout model involving inactivation of the Tsc1 gene in neurons and astrocytes (Tsc1

Short-Chain Fatty Acids Improve Poststroke Recovery Via Immunological Mechanisms, Rebecca Sadler, Julia V. Cramer, Steffanie Heindl, Sarantos Kostidis, Dene Betz, Kielen R. Zuurbier, Bernd H. Northoff, Marieke Heijink, Mark P. Goldberg, Erik J. Plautz, Stefan Roth, Rainer Malik, Martin Dichgans, Lesca M. Holdt, Corinne Benakis, Martin Giera, Ann M. Stowe, Arthur Liesz

Neurology Faculty Publications

Recovery after stroke is a multicellular process encompassing neurons, resident immune cells, and brain-invading cells. Stroke alters the gut microbiome, which in turn has considerable impact on stroke outcome. However, the mechanisms underlying gut–brain interaction and implications for long-term recovery are largely elusive. Here, we tested the hypothesis that short-chain fatty acids (SCFAs), key bioactive microbial metabolites, are the missing link along the gut–brain axis and might be able to modulate recovery after experimental stroke. SCFA supplementation in the drinking water of male mice significantly improved recovery of affected limb motor function. Using in vivo wide-field calcium imaging, we observed …

Metabolic Dysregulation In The Atp7b-/- Wilson's Disease Mouse Model, Clavia Ruth Wooton-Kee, Matthew Robertson, Ying Zhou, Bingning Dong, Zhen Sun, Kang Ho Kim, Hailan Liu, Yong Xu, Nagireddy Putluri, Pradip Saha, Cristian Coarfa, David D Moore, Alli M Nuotio-Antar

Faculty, Staff and Students Publications

Inactivating mutations in the copper transporter Atp7b result in Wilson’s disease. The Atp7b−/− mouse develops hallmarks of Wilson’s disease. The activity of several nuclear receptors decreased in Atp7b−/− mice, and nuclear receptors are critical for maintaining metabolic homeostasis. Therefore, we anticipated that Atp7b−/− mice would exhibit altered progression of diet-induced obesity, fatty liver, and insulin resistance. Following 10 wk on a chow or Western-type diet (40% kcal fat), parameters of glucose and lipid homeostasis were measured. Hepatic metabolites were measured by liquid chromatography–mass spectrometry and correlated with transcriptomic data. Atp7b−/− mice fed a chow diet presented …

Fenugreek Counters The Effects Of High Fat Diet On Gut Microbiota In Mice: Links To Metabolic Benefit, Annadora J. Bruce-Keller, Allison J. Richard, Sun-Ok Fernandez-Kim, David M. Ribnicky, J Michael Salbaum, Susan Newman Phd, Rn, Crrn, Faan, Richard Carmouche, Jacqueline M. Stephens

Publications

Fenugreek (Trigonella foenum-graecum) is an annual herbaceous plant and a staple of traditional health remedies for metabolic conditions including high cholesterol and diabetes. While the mechanisms of the beneficial actions of fenugreek remain unknown, a role for intestinal microbiota in metabolic homeostasis is likely. To determine if fenugreek utilizes intestinal bacteria to offset the adverse effects of high fat diets, C57BL/6J mice were fed control/low fat (CD) or high fat (HFD) diets each supplemented with or without 2% (w/w) fenugreek for 16 weeks. The effects of fenugreek and HFD on gut microbiota were comprehensively mapped and then statistically assessed in …

Deficient Histone H3 Propionylation By Brpf1-Kat6 Complexes In Neurodevelopmental Disorders And Cancer., Kezhi Yan, Justine Rousseau, Keren Machol, Laura A. Cross, Katherine E. Agre, Cynthia Forster Gibson, Anne Goverde, Kendra Engleman, Hannah Verdin, Elfride De Baere, Lorraine Potocki, Dihong Zhou, Maxime Cadieux-Dion, Gary A. Bellus, Monisa D. Wagner, Rebecca J. Hale, Natacha Esber, Alan F. Riley, Benjamin D. Solomon, Megan T. Cho, Kirsty Mcwalter, Roy Eyal, Meagan K. Hainlen, Bryce A. Mendelsohn, Hillary M. Porter, Brendan C. Lanpher, Andrea M. Lewis, Juliann Savatt, Isabelle Thiffault, Bert Callewaert, Philippe M. Campeau, Xiang-Jiao Yang

Manuscripts, Articles, Book Chapters and Other Papers

Lysine acetyltransferase 6A (KAT6A) and its paralog KAT6B form stoichiometric complexes with bromodomain- and PHD finger-containing protein 1 (BRPF1) for acetylation of histone H3 at lysine 23 (H3K23). We report that these complexes also catalyze H3K23 propionylation in vitro and in vivo. Immunofluorescence microscopy and ATAC-See revealed the association of this modification with active chromatin. Brpf1 deletion obliterates the acylation in mouse embryos and fibroblasts. Moreover, we identify BRPF1 variants in 12 previously unidentified cases of syndromic intellectual disability and demonstrate that these cases and known BRPF1 variants impair H3K23 propionylation. Cardiac anomalies are present in a subset of the …

Integrative Qtl Analysis Of Gene Expression And Chromatin Accessibility Identifies Multi-Tissue Patterns Of Genetic Regulation., Gregory R Keele, Bryan C Quach, Jennifer W Israel, Grace A Chappell, Lauren Lewis, Alexias Safi, Jeremy M Simon, Paul Cotney, Gregory E Crawford, William Valdar, Ivan Rusyn, Terrence S Furey

Faculty Research 2020

Gene transcription profiles across tissues are largely defined by the activity of regulatory elements, most of which correspond to regions of accessible chromatin. Regulatory element activity is in turn modulated by genetic variation, resulting in variable transcription rates across individuals. The interplay of these factors, however, is poorly understood. Here we characterize expression and chromatin state dynamics across three tissues-liver, lung, and kidney-in 47 strains of the Collaborative Cross (CC) mouse population, examining the regulation of these dynamics by expression quantitative trait loci (eQTL) and chromatin QTL (cQTL). QTL whose allelic effects were consistent across tissues were detected for 1,101 …

Striatal Acetylcholine Helps To Preserve Functional Outcomes In A Mouse Model Of Stroke, Daniela F. Goncalves, Monica S. Guzman, Robert Gros, André R. Massensini, Robert Bartha, Vania F. Prado, Marco A.M. Prado

Medical Biophysics Publications

Acetylcholine (ACh) has been suggested to facilitate plasticity and improve functional recovery after different types of brain lesions. Interestingly, numerous studies have shown that striatal cholinergic interneurons are relatively resistant to acute ischemic insults, but whether ACh released by these neurons enhances functional recovery after stroke is unknown. We investigated the role of endogenous striatal ACh in stroke lesion volume and functional outcomes following middle cerebral artery occlusion to induce focal ischemia in striatum-selective vesicular acetylcholine transporter-deficient mice (stVAChT-KO). As transporter expression is almost completely eliminated in the striatum of stVAChT-KO mice, ACh release is nearly abolished in this area. …

Targeting The Tumor Core: Hypoxia-Responsive Nanoparticles For The Delivery Of Chemotherapy To Pancreatic Tumors, Matthew I. Confeld, Babak Mamnoon, Li Feng, Heather Jensen Smith, Priyanka Ray, James Froberg, Jiha Kim, Michael A. Hollingsworth, Mohiuddin Quadir, Yongki Choi, Sanku Mallik

Journal Articles: Eppley Institute

In pancreatic ductal adenocarcinoma (PDAC), early onset of hypoxia triggers remodeling of the extracellular matrix, epithelial-to-mesenchymal transition, increased cell survival, the formation of cancer stem cells, and drug resistance. Hypoxia in PDAC is also associated with the development of collagen-rich, fibrous extracellular stroma (desmoplasia), resulting in severely impaired drug penetration. To overcome these daunting challenges, we created polymer nanoparticles (polymersomes) that target and penetrate pancreatic tumors, reach the hypoxic niches, undergo rapid structural destabilization, and release the encapsulated drugs. In vitro studies indicated a high cellular uptake of the polymersomes and increased cytotoxicity of the drugs under hypoxia compared to …

Exogenous Flupirtine As Potential Treatment For Cln3 Disease, Katia Maalouf, Joelle Makoukji, Sara Saab, Nadine J. Makhoul, Angelica V. Carmona, Nihar Kinarivala, Noël Ghanem, Paul C. Trippier, Rose-Mary Boustany

Journal Articles: Pharmaceutical Sciences

CLN3 disease is a fatal neurodegenerative disorder affecting children. Hallmarks include brain atrophy, accelerated neuronal apoptosis, and ceramide elevation. Treatment regimens are supportive, highlighting the importance of novel, disease-modifying drugs. Flupirtine and its new allyl carbamate derivative (compound 6) confer neuroprotective effects in CLN3-deficient cells. This study lays the groundwork for investigating beneficial effects in Cln3^Δex7/8 mice. WT/Cln3^Δex7/8 mice received flupirtine/compound 6/vehicle for 14 weeks. Short-term effect of flupirtine or compound 6 was tested using a battery of behavioral testing. For flupirtine, gene expression profiles, astrogliosis, and neuronal cell counts were determined. Flupirtine improved neurobehavioral parameters in …

Establishing A Myocardial Ischemia-Reperfusion Injury Model In Mice And Rats Using Left Anterior Descending Artery Ligation And Isolated Heart Experiments, Alexander Papa

PCOM Biomedical Studies Student Scholarship

Myocardial infarction (MI) is a leading cause of death globally, with over 730,000 cases each year in the United States alone. Factors involved in the prognosis of an MI include identification of the artery occluded, the time to reperfusion, the size of the infarct, and the degree of cardiomyocyte death. Thus, the treatment of MI typically involves targeting one or more of these factors. Timely opening of an occluded artery to reperfuse the ischemic tissue remains the mainstay treatment through either thrombolytic therapy, arterial stenting, or percutaneous coronary intervention. However, reperfusion itself may cause further damage through the generation of …

Extracellular Mitochondria Released From Traumatized Brains Induced Platelet Procoagulant Activity, Zilong Zhao, Yuan Zhou, Tristan Hilton, Fanjian Li, Cha Han, Li Liu, Hengjie Yuan, Ying Li, Xin Xu, Xiaoping Wu, Fangyi Zhang, Perumal Thiagarajan, Andrew Cap, Fu-Dong Shi, Jianning Zhang, Jing-Fei Dong

Faculty, Staff and Students Publications

Coagulopathy often develops soon after acute traumatic brain injury and its cause remains poorly understood. We have shown that injured brains release cellular microvesicles that disrupt the endothelial barrier and induce consumptive coagulopathy. Morphologically intact extracellular mitochondria accounted for 55.2% of these microvesicles, leading to the hypothesis that these extracellular mitochondria are metabolically active and serve as a source of oxidative stress that activates platelets and renders them procoagulant. In testing this hypothesis experimentally, we found that the extracellular mitochondria purified from brain trauma mice and those released from brains subjected to freeze-thaw injury remained metabolically active and produced reactive …

Sirt3 Promotes Lipophagy And Chaperon-Mediated Autophagy To Protect Hepatocytes Against Lipotoxicity, Tian Zhang, Jingxin Liu, Shengnan Shen, Qiang Tong, Xiaojun Ma, Ligen Lin

Faculty, Staff and Students Publications

Lipophagy is a lysosomal lipolytic pathway that complements the actions of cytosolic neutral lipases. Chaperon-mediated autophagy (CMA) triggers lipid droplets (LDs) breakdown, to initiate lipolysis via either cytosolic lipases or macroautophagy. SIRT3, a mitochondrial NAD+-dependent deacetylase, regulates the acetylation status and activity of many substrates involving in energy metabolism. However, the role of SIRT3 in regulating lipophagy is controversial. The current study showed that SIRT3 expression was decreased and the macroautophagy flux was blocked in the primary hepatocytes from high-fat diet fed mice and P/O (palmitic acid and oleic acid mixture) treated AML12 mouse hepatocytes, compared with the corresponding controls. …

Small Molecules That Inhibit Tnf Signalling By Stabilising An Asymmetric Form Of The Trimer, James O'Connell, John Porter, Boris Kroeplien, Tim Norman, Stephen Rapecki, Rachel E. Davis, David Mcmillan, Tracy Arakaki, Alex Burgin, David Fox Iii, Tom Ceska, Fabien Lecomte, Alison Maloney, Alex Vugler, Bruce Carrington, Benjamin P. Cossins, Tim Bourne, Alastair Lawson

Faculty Publications

Tumour necrosis factor (TNF) is a cytokine belonging to a family of trimeric proteins; it has been shown to be a key mediator in autoimmune diseases such as rheumatoid arthritis and Crohn's disease. While TNF is the target of several successful biologic drugs, attempts to design small molecule therapies directed to this cytokine have not led to approved products. Here we report the discovery of potent small molecule inhibitors of TNF that stabilise an asymmetrical form of the soluble TNF trimer, compromising signalling and inhibiting the functions of TNF in vitro and in vivo. This discovery paves the way for …

Ultrafast Two-Photon Imaging Of A High-Gain Voltage Indicator In Awake Behaving Mice, Vincent Villette, Mariya Chavarha, Ivan K Dimov, Jonathan Bradley, Lagnajeet Pradhan, Benjamin Mathieu, Stephen W Evans, Simon Chamberland, Dongqing Shi, Renzhi Yang, Benjamin B Kim, Annick Ayon, Abdelali Jalil, François St-Pierre, Mark J Schnitzer, Guoqiang Bi, Katalin Toth, Jun Ding, Stéphane Dieudonné, Michael Z Lin

Faculty, Staff and Students Publications

Optical interrogation of voltage in deep brain locations with cellular resolution would be immensely useful for understanding how neuronal circuits process information. Here, we report ASAP3, a genetically encoded voltage indicator with 51% fluorescence modulation by physiological voltages, submillisecond activation kinetics, and full responsivity under two-photon excitation. We also introduce an ultrafast local volume excitation (ULoVE) method for kilohertz-rate two-photon sampling in vivo with increased stability and sensitivity. Combining a soma-targeted ASAP3 variant and ULoVE, we show single-trial tracking of spikes and subthreshold events for minutes in deep locations, with subcellular resolution and with repeated sampling over days. In the …

Chronic Muscle Weakness And Mitochondrial Dysfunction In The Absence Of Sustained Atrophy In A Preclinical Sepsis Model, Allison M. Owen, Samir P. Patel, Jeffrey D. Smith, Beverly K. Balasuriya, Stephanie F. Mori, Gregory S. Hawk, Arnold J. Stromberg, Naohide Kuriyama, Masao Kaneki, Alexander G. Rabchevsky, Timothy A. Butterfield, Karyn A. Esser, Charlotte A. Peterson, Marlene E. Starr, Hiroshi Saito

Physiology Faculty Publications

Chronic critical illness is a global clinical issue affecting millions of sepsis survivors annually. Survivors report chronic skeletal muscle weakness and development of new functional limitations that persist for years. To delineate mechanisms of sepsis-induced chronic weakness, we first surpassed a critical barrier by establishing a murine model of sepsis with ICU-like interventions that allows for the study of survivors. We show that sepsis survivors have profound weakness for at least 1 month, even after recovery of muscle mass. Abnormal mitochondrial ultrastructure, impaired respiration and electron transport chain activities, and persistent protein oxidative damage were evident in the muscle of …

Defining The Layers Of A Sensory Cilium With Storm And Cryoelectron Nanoscopy, Michael A Robichaux, Valencia L Potter, Zhixian Zhang, Feng He, Jun Liu, Michael F Schmid, Theodore G Wensel

Faculty, Staff and Students Publications

Primary cilia carry out numerous signaling and sensory functions, and defects in them, "ciliopathies," cause a range of symptoms, including blindness. Understanding of their nanometer-scale ciliary substructures and their disruptions in ciliopathies has been hindered by limitations of conventional microscopic techniques. We have combined cryoelectron tomography, enhanced by subtomogram averaging, with superresolution stochastic optical reconstruction microscopy (STORM) to define subdomains within the light-sensing rod sensory cilium of mouse retinas and reveal previously unknown substructures formed by resident proteins. Domains are demarcated by structural features such as the axoneme and its connections to the ciliary membrane, and are correlated with molecular …

Interleukin 1 Alpha Administration Is Neuroprotective And Neuro-Restorative Following Experimental Ischemic Stroke, Kathleen E. Salmeron, Michael E. Maniskas, Danielle N. Edwards, Raymond Wong, Ivana Rajkovic, Amanda L. Trout, Abir A. Rahman, Samantha Hamilton, Justin F. Fraser, Emmanuel Pinteaux, Gregory J. Bix

Sanders-Brown Center on Aging Faculty Publications

BACKGROUND: Stroke remains a leading cause of death and disability worldwide despite recent treatment breakthroughs. A primary event in stroke pathogenesis is the development of a potent and deleterious local and peripheral inflammatory response regulated by the pro-inflammatory cytokine interleukin-1 (IL-1). While the role of IL-1β (main released isoform) has been well studied in stroke, the role of the IL-1α isoform remains largely unknown. With increasing utilization of intravenous tissue plasminogen activator (t-PA) or thrombectomy to pharmacologically or mechanically remove ischemic stroke causing blood clots, respectively, there is interest in pairing successful cerebrovascular recanalization with neurotherapeutic pharmacological interventions (Fraser et …

Sirna Targeting And Treatment Of Gastrointestinal Diseases., Rachel Chevalier

Manuscripts, Articles, Book Chapters and Other Papers

RNA interference via small interfering RNA (siRNA) offers opportunities to precisely target genes that contribute to gastrointestinal (GI) pathologies, such as inflammatory bowel disease, celiac, and esophageal scarring. Delivering the siRNA to the GI tract proves challenging as the harsh environment of the intestines degrades the siRNA before it can reach its target or blocks its entry into its site of action in the cytoplasm. Additionally, the GI tract is large and disease is often localized to a specific site. This review discusses polymer and lipid-based delivery systems for protection and targeting of siRNA therapies to the GI tract to …