Digital Commons Network^™

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 …

Dynamic Imaging Of Ldh Inhibition In Tumors Reveals Rapid In Vivo Metabolic Rewiring And Vulnerability To Combination Therapy, Nobu Oshima, Ryo Ishida, Shun Kishimoto, Kristin Beebe, Jeffrey R. Brender, Kazutoshi Yamamoto, Daniel Urban, Ganesha Rai, Michelle S. Johnson, Gloria Benavides, Giuseppe L. Squadrito, Dan Crooks, Joseph Jackson, Abhinav Joshi, Bryan T. Mott, Jonathan H. Shrimp, Michael A. Moses, Min-Jung Lee, Akira Yuno, Tobie D. Lee, Xin Hu, Tamara Anderson, Donna Kusewitt, Helen H. Hathaway, Ajit Jadhav, Didier Picard, Jane B. Trepel, James B. Mitchell, Gordon M. Stott, William Moore, Anton Simeonov, Larry A. Sklar, Jeffrey P Norenberg, W Marston Linehan, David J. Maloney, Chi V. Dang, Alex G. Waterson, Matthew Hall, Victor M. Darley-Usmar, Murali C. Krishna, Leonard M. Neckers

Pathology Research and Scholarship

The reliance of many cancers on aerobic glycolysis has stimulated efforts to develop lactate dehydrogenase (LDH) inhibitors. However, despite significant efforts, LDH inhibitors (LDHi) with sufficient specificity and in vivo activity to determine whether LDH is a feasible drug target are lacking. We describe an LDHi with potent, on-target, in vivo activity. Using hyperpolarized magnetic resonance spectroscopic imaging (HP-MRSI), we demonstrate in vivo LDH inhibition in two glycolytic cancer models, MIA PaCa-2 and HT29, and we correlate depth and duration of LDH inhibition with direct anti-tumor activity. HP-MRSI also reveals a metabolic rewiring that occurs in vivo within 30 min …

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 …

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 …

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 …

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 …

Remember That Party Last Night? Examining The Effects Of Binge-Like Alcohol On Memory, Anna Thomas

Undergraduate Honors Thesis Collection

Alcohol is a widely available drug that is often abused. Studies have shown alcohol-induced memory loss in humans and animals; however, the large amount of alcohol often necessary to observe such loss and use of involuntary drinking paradigms in animals makes translation difficult. The current study was designed to look at voluntary binge-like drinking behavior and memory in rodents. We anticipated decreases in working memory function following consumption of binge-like alcohol in mice and expected a greater deficit in mice experiencing acute withdrawal during the memory task. The present study explored drinking behaviors in adult C57BL/6J mice (18 male, 18 …

Rage Signaling As A Pharmacological Target In Amyotrophic Lateral Sclerosis, Liping Liu

MUSC Theses and Dissertations

Amyotrophic lateral sclerosis (ALS) is characterized by the progressive degeneration of both upper and lower motor neurons. Astrocytes are key for maintaining central nervous system homeostasis and are important determinants of motor neuron fate in ALS. Accordingly, IPSC-derived astrocytes from ALS patients or astrocytes from diverse ALS mouse models, including mice overexpressing the ALS-linked mutant hSOD1G93A, induce motor neuron death in co-culture. Previously our lab reported that motor neurons isolated from receptor for advanced glycation end products (RAGE) knockout mice are resistant to the ALS-astrocyte derived neurotoxicity. Therefore, our working hypothesis states that inhibition of RAGE signaling can suppress astrocyte-mediated …

Targeting Transcription Factors Xbp-1 And Fli-1 As Novel Translational Strategies To Control Graft-Versus-Host Disease, Steven Douglas Schutt

MUSC Theses and Dissertations

Hematopoietic stem-cell transplantation (HCT) is a curative procedure for hematological malignancies, but chronic graft-versus-host disease (GVHD) remains a major complication after allogeneic HCT. Because donor B cells are essential for chronic GVHD (cGVHD) development and B cells are sensitive to endoplasmic reticulum stress, we hypothesized that the IRE-1α/XBP-1 pathway is required for B-cell activation and function in cGVHD. Here, we used mice deficient of XBP-1 specifically in B cells, and recipients transplanted with grafts containing XBP-1–deficient B cells displayed reduced cGVHD compared with controls that was associated with reduced B-cell activation and production of alloreactive antibodies. Prophylactic administration of B-I09 …

Altered Circadian Rhythm And Neuroinflammation In Models Of Als: A Role For Nr1d1 And Fabp7, Kelby Killoy

MUSC Theses and Dissertations

Most physiological processes in mammals are subjected to daily oscillations governed by a circadian system. Circadian rhythm orchestrates metabolic pathways in a time-dependent manner and loss of circadian timekeeping has been associated with cellular and system-wide alterations in metabolism, redox homeostasis, and inflammation. Nuclear Receptor subfamily 1 group D member 1 (NR1D1) is a transcription factor that participates in the molecular clock that encodes circadian rhythms and links metabolism and inflammation to circadian cycles. Fatty acid binding protein 7 (FABP7), an NR1D1 target, is a regulator of lipid metabolism, energy homeostasis, and inflammation. FABP7 can regulate fatty acid uptake, transport, …

Validation Of Ninein As An Ethanol-Related Quantitative Trait Gene: Reassessment, Design, And Functional Validation Of Reference Genes For Qpcr Analysis Of Brain Tissue In Mice, Jessica L. Jurmain

Theses and Dissertations

The increasing use of quantitative real-time polymerase chain reaction (qPCR) as a method for quantifying gene expression has led to an increased demand for standardization of data analysis methods to ensure accurate reporting and robust, reproducible results. The exponential nature of qPCR amplification results in the potential magnification of what are usually very small sources of error. Relative gene expression calculations circumvent this issue by normalizing target gene expression data to within-sample expression of a previously validated, stably expressed reference gene or genes. Multiple studies discussed herein have found that qPCR data are more reliable and reproducible when multiple reference …

Assessment Of In Vivo Muscle Force In The R6/2 Mouse Model Of Huntington's Disease Using Newly Designed Force Rig, Steven Russell Alan Burke

Browse all Theses and Dissertations

In this thesis, we develop a system to study in vivo muscle function in a mouse model of Huntington’s disease that allows for the recording of muscle force by stimulating the motor nerves or the muscles directly after a nerve block. This allows us to distinguish between defects in the nerve, such as problems with vesicle release, and primary muscle defects, such as altered intracellular calcium homeostasis. We hypothesize that there are primary defects in R6/2 skeletal muscle that are separate from neurodegeneration or defects in the CNS. In this case, we should see defects in muscle force generation during …

Novel Duel Mtor Inhibitors/Ampk Activators Improve Therapeutic Efficacy Of Doxorubicin And Ameliorate Its Associated Cardiotoxicity In Mice, Sahak Eric Hovsepian

Theses and Dissertations

Triple-negative breast cancer (TNBC) is a particularly aggressive subset of breast cancer that has a molecular expression profile which lacks the estrogen receptor (ER), progesterone receptor (ER), and human epidermal growth factor receptor type 2 (HER2). No targeted treatment options currently exist for TNBC, unlike other types of breast cancer, and therefore survival rates are far lower for these patients. The current treatment for TNBC is systemic anthracycline chemotherapy, typically doxorubicin (DOX), which has great clinical efficacy in increasing survival. However, DOX induces a dose-dependent progressive cardiomyopathy, which can present years and up to decades after the last treatment. This …

Granulosa Cell Proliferation Is Inhibited By Pge2 In The Primate Ovulatory Follicle, Patric S. Lundberg, Gil J. Moskowitz, Carmel Bellacose, Esra Demirel, Heidi A. Trau, Diane M. Duffy

Computer Science Faculty Publications

Prostaglandin E2 (PGE2) is a key paracrine mediator of ovulation. Few specific PGE2-regulated gene products have been identified, so we hypothesized that PGE2 may regulate the expression and/or activity of a network of proteins to promote ovulation. To test this concept, Ingenuity Pathway Analysis (IPA) was used to predict PGE2-regulated functionalities in the primate ovulatory follicle. Cynomolgus macaques underwent ovarian stimulation. Follicular granulosa cells were obtained before (0 h) or 36 h after an ovulatory dose of human chorionic gonadotropin (hCG), with ovulation anticipated 37-40 h after hCG. Granulosa cells were obtained from additional monkeys 36 h after treatment with …

Combined Abdominal Heterotopic Heart And Aorta Transplant Model In Mice, Hao Dun, Li Ye, Yuehui Zhu, Brian W Wong

Open Access Publications

BACKGROUND: Allograft vasculopathy (AV) remains a major obstacle to long-term allograft survival. While the mouse aortic transplantation model has been proven as a useful tool for study of the pathogenesis of AV, simultaneous transplantation of the aorta alongside the transplantation of another organ may reveal more clinically relevant mechanisms that contribute to the pathogenesis of chronic allograft rejection. Therefore, we developed a combined abdominal heart and aorta transplantation model in mice which benefits from reducing animal and drug utilization, while providing an improved model to study the progressive nature of AV.

METHODS: The middle of the infrarenal aorta of the …

Rev-Erb Agonism Improves Liver Pathology In A Mouse Model Of Nash, Kristine Griffett, Gonzalo Bedia-Diaz, Bahaa Elgendy, Thomas P. Burris

Open Access Publications

Non-alcoholic fatty liver disease (NAFLD) affects a significant number of people worldwide and currently there are no pharmacological treatments. NAFLD often presents with obesity, insulin resistance, and in some cases cardiovascular diseases. There is a clear need for treatment options to alleviate this disease since it often progresses to much more the much more severe non-alcoholic steatohepatitis (NASH). The REV-ERB nuclear receptor is a transcriptional repressor that regulates physiological processes involved in the development of NAFLD including lipogenesis and inflammation. We hypothesized that pharmacologically activating REV-ERB would suppress the progression of fatty liver in a mouse model of NASH. Using …

Client Processing Is Altered By Novel Myopathy-Causing Mutations In The Hsp40 J Domain, Melanie Y. Pullen, Conrad C. Weihl, Heather L. True

Open Access Publications

The misfolding and aggregation of proteins is often implicated in the development and progression of degenerative diseases. Heat shock proteins (HSPs), such as the ubiquitously expressed Type II Hsp40 molecular chaperone, DNAJB6, assist in protein folding and disaggregation. Historically, mutations within the DNAJB6 G/F domain have been associated with Limb-Girdle Muscular Dystrophy type 1D, now referred to as LGMDD1, a dominantly inherited degenerative disease. Recently, novel mutations within the J domain of DNAJB6 have been reported in patients with LGMDD1. Since novel myopathy-causing mutations in the Hsp40 J domain have yet to be characterized and both the function of DNAJB6 …

Cd4 Inhibits Helper T Cell Activation At Lower Affinity Threshold For Full-Length T Cell Receptors Than Single Chain Signaling Constructs, Deborah K Johnson, Wyatt Magoffin, Sheldon J Myers, Jordan G Finnell, John C Hancock, Taylor S Orton, Stephen P Persaud, Kenneth A Christensen, K Scott Weber

Open Access Publications

CD4

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 …

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 …

Regional Gene Repression By Dna Double-Strand Breaks In G1 Phase Cells, Caitlin E. Purman, Patrick L. Collins, Sofia I. Porter, Ankita Saini, Harshath Gupta, Barry P. Sleckman, Eugene M. Oltz

Open Access Publications

DNA damage responses (DDR) to double-strand breaks (DSBs) alter cellular transcription programs at the genome-wide level. Through processes that are less well understood, DSBs also alter transcriptional responses locally, which may be important for efficient DSB repair. Here, we developed an approach to elucidate the

Distinct Roles Of Interferon Alpha And Beta In Controlling Chikungunya Virus Replication And Modulating Neutrophil-Mediated Inflammation, Lindsey E Cook, Marissa C Locke, Alissa R Young, Kristen Monte, Matthew L Hedberg, Raeann M Shimak, Kathleen C F Sheehan, Deborah J Veis, Michael S Diamond, Deborah J Lenschow

Open Access Publications

Type I interferons (IFNs) are key mediators of the innate immune response. Although members of this family of cytokines signal through a single shared receptor, biochemical and functional variation exists in response to different IFN subtypes. While previous work has demonstrated that type I IFNs are essential to control infection by chikungunya virus (CHIKV), a globally emerging alphavirus, the contributions of individual IFN subtypes remain undefined. To address this question, we evaluated CHIKV pathogenesis in mice lacking IFN-β (IFN-β knockout [IFN-β-KO] mice or mice treated with an IFN-β-blocking antibody) or IFN-α (IFN regulatory factor 7 knockout [IRF7-KO] mice or mice …

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 …