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The Zebrafish As A Potential Model For Vaccine And Adjuvant Development, Peter J Hotez, Maria Elena Bottazzi, Nelufa Yesmin Islam, Jungsoon Lee, Jeroen Pollet, Cristina Poveda, Ulrich Strych, Syamala Rani Thimmiraju, Nestor L Uzcategui, Leroy Versteeg, Daniel Gorelick

Faculty, Staff and Students Publications

Introduction: Zebrafishes represent a proven model for human diseases and systems biology, exhibiting physiological and genetic similarities and having innate and adaptive immune systems. However, they are underexplored for human vaccinology, vaccine development, and testing. Here we summarize gaps and challenges.

Areas covered: Zebrafish models have four potential applications: 1) Vaccine safety: The past successes in using zebrafishes to test xenobiotics could extend to vaccine and adjuvant formulations for general safety or target organs due to the zebrafish embryos' optical transparency. 2) Innate immunity: The zebrafish offers refined ways to examine vaccine effects through signaling via Toll-like or NOD-like receptors …

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 …

Siglec15, Negatively Correlated With Pd-L1 In Hcc, Could Induce Cd8+ T Cell Apoptosis To Promote Immune Evasion, Zheng Chen, Mincheng Yu, Bo Zhang, Lei Jin, Qiang Yu, Shuang Liu, Binghai Zhou, Jiuliang Yan, Wentao Zhang, Xiaoqiang Li, Yongfeng Xu, Yongsheng Xiao, Jian Zhou, Jia Fan, Mien-Chie Hung, Qinghai Ye, Hui Li, Lei Guo

Faculty, Staff and Student Publications

Functional roles of SIGLEC15 in hepatocellular carcinoma (HCC) were not clear, which was recently found to be an immune inhibitor with similar structure of inhibitory B7 family members. SIGLEC15 expression in HCC was explored in public databases and further examined by PCR analysis. SIGLEC15 and PD-L1 expression patterns were examined in HCC samples through immunohistochemistry. SIGLEC15 expression was knocked-down or over-expressed in HCC cell lines, and CCK8 tests were used to examine cell proliferative ability in vitro. Influences of SIGLEC15 expression on tumor growth were examined in immune deficient and immunocompetent mice respectively. Co-culture system of HCC cell lines and …

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 …

Branched-Chain Amino Acid Accumulation Fuels The Senescence-Associated Secretory Phenotype, Yaosi Liang, Christopher Pan, Tao Yin, Lu Wang, Xia Gao, Ergang Wang, Holly Quang, De Huang, Lianmei Tan, Kun Xiang, Yu Wang, Peter B Alexander, Qi-Jing Li, Tso-Pang Yao, Zhao Zhang, Xiao-Fan Wang

Faculty, Staff and Students Publications

The essential branched-chain amino acids (BCAAs) leucine, isoleucine, and valine play critical roles in protein synthesis and energy metabolism. Despite their widespread use as nutritional supplements, BCAAs' full effects on mammalian physiology remain uncertain due to the complexities of BCAA metabolic regulation. Here a novel mechanism linking intrinsic alterations in BCAA metabolism is identified to cellular senescence and the senescence-associated secretory phenotype (SASP), both of which contribute to organismal aging and inflammation-related diseases. Altered BCAA metabolism driving the SASP is mediated by robust activation of the BCAA transporters Solute Carrier Family 6 Members 14 and 15 as well as downregulation …

Crystal Structure Of Trichinella Spiralis Calreticulin And The Structural Basis Of Its Complement Evasion Mechanism Involving C1q, Zhihui Jia, Wen Yu, Jingmo Li, Mingming Zhang, Bin Zhan, Liming Yan, Zhenhua Ming, Yuli Cheng, Xiaolin Tian, Shuai Shao, Jingjing Huang, Xinping Zhu

Faculty, Staff and Students Publications

Helminths produce calreticulin (CRT) to immunomodulate the host immune system as a survival strategy. However, the structure of helminth-derived CRT and the structural basis of the immune evasion process remains unclarified. Previous study found that the tissue-dwelling helminth Trichinella spiralis produces calreticulin (TsCRT), which binds C1q to inhibit activation of the complement classical pathway. Here, we used x-ray crystallography to resolve the structure of truncated TsCRT (TsCRTΔ), the first structure of helminth-derived CRT. TsCRTΔ was observed to share the same binding region on C1q with IgG based on the structure and molecular docking, which explains the inhibitory effect of TsCRT …

The Uterine Secretome Initiates Growth Of Gynecologic Tissues In Ectopic Locations, Jan Sunde, Morgan Wasickanin, Tiffany A Katz, Laurel Gillette, Sanam Bidadi, Derek O'Neil, Ramya Masand, Richard O Burney, Kathleen A Pennington

Faculty, Staff and Students Publications

Endosalpingiosis (ES) and endometriosis (EM) refer to the growth of tubal and endometrial epithelium respectively, outside of their site of origin. We hypothesize that uterine secretome factors drive ectopic growth. To test this, we developed a mouse model of ES and EM using tdTomato (tdT) transgenic fluorescent mice as donors. To block implantation factors, progesterone knockout (PKO) tdT mice were created. Fluorescent lesions were present after oviduct implantation with and without WT endometrium. Implantation was increased (p<0.05) when tdt oviductal tissue was implanted with endometrium compared to oviductal tissue alone. Implantation was reduced (p<0.0005) in animals implanted with minced tdT oviductal tissue with PKO tdT endometrium compared to WT endometrium. Finally, oviductal tissues was incubated with and without a known implantation factor, leukemia inhibitory factor (LIF) prior to and during implantation. LIF promoted lesion implantation. In conclusion, endometrial derived implantation factors, such as LIF, are necessary to initiate ectopic tissue growth. We have developed an animal model of ectopic growth of gynecologic tissues in a WT mouse which will potentially allow for development of new prevention and treatment modalities.

Vaccines Against Extraintestinal Pathogenic Escherichia Coli (Expec): Progress And Challenges, Ling Qiu, Dylan Chirman, Justin R Clark, Yikun Xing, Haroldo Hernandez Santos, Ellen E Vaughan, Anthony W Maresso

Faculty, Staff and Students Publications

The emergence of antimicrobial resistance (AMR) is a principal global health crisis projected to cause 10 million deaths annually worldwide by 2050. While the Gram-negative bacteria Escherichia coli is commonly found as a commensal microbe in the human gut, some strains are dangerously pathogenic, contributing to the highest AMR-associated mortality. Strains of E. coli that can translocate from the gastrointestinal tract to distal sites, called extraintestinal E. coli (ExPEC), are particularly problematic and predominantly afflict women, the elderly, and immunocompromised populations. Despite nearly 40 years of clinical trials, there is still no vaccine against ExPEC. One reason for this is …

Select Gut Microbiota Impede Rotavirus Vaccine Efficacy, Vu L Ngo, Yanling Wang, Yadong Wang, Zhenda Shi, Robert Britton, Jun Zou, Sasirekha Ramani, Baoming Jiang, Andrew T Gewirtz

Faculty, Staff and Students Publications

BACKGROUND & AIMS: The protection provided by rotavirus (RV) vaccines is highly heterogeneous among individuals. We hypothesized that microbiota composition might influence RV vaccine efficacy.

METHODS: First, we examined the potential of segmented filamentous bacteria (SFB) colonization to influence RV vaccine efficacy in mice. Next, we probed the influence of human microbiomes on RV vaccination via administering mice fecal microbial transplants (FMTs) from children with robust or minimal RV vaccine responsiveness. Post-FMT, mice were subjected to RV vaccination followed by RV challenge.

RESULTS: SFB colonization induced a phenotype that was reminiscent of RV vaccine failure (ie, failure to generate RV …

Pik-Iii Exerts Anti-Fibrotic Effects In Activated Fibroblasts By Regulating P38 Activation, Santiago Sanchez, Aaron K Mcdowell-Sanchez, Sharaz B Al-Meerani, Juan D Cala-Garcia, Alan R Waich Cohen, Scott A Ochsner, Neil J Mckenna, Lindsay J Celada, Minghua Wu, Shervin Assassi, Ivan O Rosas, Konstantin Tsoyi

Faculty, Staff and Students Publications

Systemic sclerosis (SSc), also known as scleroderma, is an autoimmune-driven connective tissue disorder that results in fibrosis of the skin and internal organs such as the lung. Fibroblasts are known as the main effector cells involved in the progression of SSc through the induction of extracellular matrix (ECM) proteins and myofibroblast differentiation. Here, we demonstrate that 4'-(cyclopropylmethyl)-N2-4-pyridinyl-[4,5'-bipyrimidine]-2,2'-diamine (PIK-III), known as class III phosphatidylinositol 3-kinase (PIK3C3/VPS34) inhibitor, exerts potent antifibrotic effects in human dermal fibroblasts (HDFs) by attenuating transforming growth factor-beta 1 (TGF-β1)-induced ECM expression, cell contraction and myofibroblast differentiation. Unexpectedly, neither genetic silencing of PIK3C3 nor other PIK3C3 inhibitors (e.g., …

Phenotypic And Functional Assessment Of Two Novel Kcnq2 Gain-Of-Function Variants Y141n And G239s And Effects Of Amitriptyline Treatment, Allan Bayat, Stefano Iavarone, Francesco Miceli, Anne V Jakobsen, Katrine M Johannesen, Marina Nikanorova, Rafal Ploski, Krystyna Szymanska, Robert Flamini, Edward C Cooper, Sarah Weckhuysen, Maurizio Taglialatela, Rikke S Møller

Faculty, Staff and Students Publications

While loss-of-function (LoF) variants in KCNQ2 are associated with a spectrum of neonatal-onset epilepsies, gain-of-function (GoF) variants cause a more complex phenotype that precludes neonatal-onset epilepsy. In the present work, the clinical features of three patients carrying a de novo KCNQ2 Y141N (n = 1) or G239S variant (n = 2) respectively, are described. All three patients had a mild global developmental delay, with prominent language deficits, and strong activation of interictal epileptic activity during sleep. Epileptic seizures were not reported. The absence of neonatal seizures suggested a GoF effect and prompted functional testing of the variants. In vitro whole-cell …

Neuronal Ablation Of Ghsr Mitigates Diet-Induced Depression And Memory Impairment Via Ampk-Autophagy Signaling-Mediated Inflammation, Hongying Wang, Zheng Shen, Chia-Shan Wu, Pengfei Ji, Ji Yeon Noh, Cédric G Geoffroy, Sunja Kim, David Threadgill, Jianrong Li, Yu Zhou, Xiaoqiu Xiao, Hui Zheng, Yuxiang Sun

Faculty, Staff and Students Publications

Obesity is associated with chronic inflammation in the central nervous system (CNS), and neuroinflammation has been shown to have detrimental effects on mood and cognition. The growth hormone secretagogue receptor (GHSR), the biologically relevant receptor of the orexigenic hormone ghrelin, is primarily expressed in the brain. Our previous study showed that neuronal GHSR deletion prevents high-fat diet-induced obesity (DIO). Here, we investigated the effect of neuronal GHSR deletion on emotional and cognitive functions in DIO. The neuron-specific GHSR-deficient mice exhibited reduced depression and improved spatial memory compared to littermate controls under DIO. We further examined the cortex and hippocampus, the …

Neutrophil-Derived Activin-A Moderates Their Pro-Netotic Activity And Attenuates Collateral Tissue Damage Caused By Influenza A Virus Infection, Georgios Divolis, Evgenia Synolaki, Athanasia Doulou, Ariana Gavriil, Christina C Giannouli, Anastasia Apostolidou, Martyn L Foster, Martin M Matzuk, Panagiotis Skendros, Ioanna-Evdokia Galani, Paschalis Sideras

Faculty, Staff and Students Publications

BACKGROUND: Pre-neutrophils, while developing in the bone marrow, transcribe the Inhba gene and synthesize Activin-A protein, which they store and release at the earliest stage of their activation in the periphery. However, the role of neutrophil-derived Activin-A is not completely understood.

METHODS:To address this issue, we developed a neutrophil-specific Activin-A-deficient animal model (S100a8-Cre/Inhba fl/fl mice) and analyzed the immune response to Influenza A virus (IAV) infection. More specifically, evaluation of body weight and lung mechanics, molecular and cellular analyses of bronchoalveolar lavage fluids, flow cytometry and cell sorting of lung cells, as well as histopathological analysis of lung tissues, …

Night-Time Neuronal Activation Of Cluster N In A North American Songbird\, Jennifer Rudolf, Natalie Philipello, Tamara Fleihan, J David Dickman, Kira E Delmore

Faculty, Staff and Students Publications

Night-migrating songbirds utilize the Earth's magnetic field to help navigate to and from their breeding sites each year. A region of the avian forebrain called Cluster N has been shown to be activated during night migratory behavior and it has been implicated in processing geomagnetic information. Previous studies with night-migratory European songbirds have shown that neuronal activity at Cluster N is higher at night than during the day. Comparable work in North American migrants has only been performed in one species of swallows, so extension of examination for Cluster N in other migratory birds is needed. In addition, it is …

Generation And Characterization Of In Vitro Transcribed Mrna, Cristina Poveda, Yi-Lin Chen, Ulrich Strych

Faculty, Staff and Students Publications

Here we describe the in vitro preparation of mRNA from DNA templates, including setting up the transcription reaction, mRNA capping, and mRNA labeling. We then describe methods used for mRNA characterization, including UV and fluorescence spectrophotometry, as well as gel electrophoresis. Moreover, characterization of the in vitro transcribed RNA using the Bioanalyzer instrument is described, allowing a higher resolution analysis of the target molecules. For the in vitro testing of the mRNA molecules, we include protocols for the transfection of various primary cell cultures and the confirmation of translation by intracellular staining and western blotting.

Lung Infection With Classical Klebsiella Pneumoniae Strains Establishes Robust Macrophage-Dependent Protection Against Heterologous Reinfection, Joseph J Mackel, Casey L G Mick, Emily Guo, David A Rosen

2020-Current year OA Pubs

At present, there is no approved vaccine for prevention of infection by the opportunistic bacterium Klebsiella pneumoniae (Kp); success in treating these infections is increasingly challenged by the spread of antibiotic resistance. Preclinical investigation of adaptive immunity elicited by lung infection with live classical Kp may reveal host mechanisms of protection against this pathogen. Here, we utilize multiple virulent classical Kp strains to demonstrate that following lung infection, surviving wild-type mice develop protective immunity against both homologous and heterologous (heterotypic) reinfection. For Kp strains with low capacity to disseminate from the lung, this immunity is B-cell-independent. We further demonstrate that …

A Novel Crispr/Cas9-Mediated Mouse Model Of Colon Carcinogenesis, Hajime Kashima, Anthony Fischer, Daniel A Veronese-Paniagua, Vered A Gazit, Changqing Ma, Yan Yan, Marc S Levin, Blair B Madison, Deborah C Rubin

2020-Current year OA Pubs

BACKGROUND & AIMS: Human sporadic colorectal cancer (CRC) results from a multistep pathway with sequential acquisition of specific genetic mutations in the colorectal epithelium. Modeling CRC in vivo is critical for understanding the tumor microenvironment. To accurately recapitulate human CRC pathogenesis, mouse models must include these multi-step genetic abnormalities. The aim of this study was to generate a sporadic CRC model that more closely mimics this multi-step process and to use this model to study the role of a novel Let7 target PLAGL2 in CRC pathogenesis.

METHODS: We generated a CRISPR/Cas9 somatic mutagenesis mouse model that is inducible and multiplexed …

Transcriptomic Profiling Of Thymic Dysregulation And Viral Tropism After Neonatal Roseolovirus Infection, Andrei Belean, Eden Xue, Benjamin Cisneros, Elisha D O Roberson, Michael A Paley, Tarin M Bigley

2020-Current year OA Pubs

INTRODUCTION: Herpesviruses, including the roseoloviruses, have been linked to autoimmune disease. The ubiquitous and chronic nature of these infections have made it difficult to establish a causal relationship between acute infection and subsequent development of autoimmunity. We have shown that murine roseolovirus (MRV), which is highly related to human roseoloviruses, induces thymic atrophy and disruption of central tolerance after neonatal infection. Moreover, neonatal MRV infection results in development of autoimmunity in adult mice, long after resolution of acute infection. This suggests that MRV induces durable immune dysregulation.

METHODS: In the current studies, we utilized single-cell RNA sequencing (scRNAseq) to study …

Pd-L1 Has A Heterogeneous And Dynamic Expression In Gastric Cancer With Implications For Immunopet, Dina Ibrahim, Cristina Simó, Emma L Brown, Shayla Shmuel, Sandeep Surendra Panikar, Alex Benton, Rachel Deweerd, Farrokh Dehdashti, Haeseong Park, Patrícia M R Pereira

2020-Current year OA Pubs

INTRODUCTION: This study aimed to investigate the dynamics of programmed death-ligand 1 (PD-L1) expression, spatial heterogeneity, and binding affinity of FDA-approved anti-PD-L1 antibodies (avelumab and atezolizumab) in gastric cancer. Additionally, we determined how PD-L1 glycosylation impacts antibody accumulation in gastric cancer cells.

METHODS: Dynamic PD-L1 expression was examined in NCIN87 gastric cancer cells. Comparative binding studies of avelumab and atezolizumab were conducted in gastric cancer models, both

RESULTS: Consistent findings revealed time-dependent PD-L1 induction in NCIN87 gastric cancer cells and spatial heterogeneity in tumors, as shown by PET imaging and immunofluorescence. Avelumab displayed superior binding affinity to NCIN87 cells compared …

Loss Of Β-Cell Identity And Dedifferentiation, Not An Irreversible Process?, Sumit Patel, Maria S Remedi

2020-Current year OA Pubs

Type 2 diabetes (T2D) is a polygenic metabolic disorder characterized by insulin resistance in peripheral tissues and impaired insulin secretion by the pancreas. While the decline in insulin production and secretion was previously attributed to apoptosis of insulin-producing β-cells, recent studies indicate that β-cell apoptosis rates are relatively low in diabetes. Instead, β-cells primarily undergo dedifferentiation, a process where they lose their specialized identity and transition into non-functional endocrine progenitor-like cells, ultimately leading to β-cell failure. The underlying mechanisms driving β-cell dedifferentiation remain elusive due to the intricate interplay of genetic factors and cellular stress. Understanding these mechanisms holds the …

Hormonal And Circuit Mechanisms Controlling Female Sexual Behavior, Sayaka Inoue

2020-Current year OA Pubs

Sexual behavior is crucial for reproduction in many animals. In many vertebrates, females exhibit sexual behavior only during a brief period surrounding ovulation. Over the decades, studies have identified the roles of ovarian sex hormones, which peak in levels around the time of ovulation, and the critical brain regions involved in the regulation of female sexual behavior. Modern technical innovations have enabled a deeper understanding of the neural circuit mechanisms controlling this behavior. In this review, I summarize our current knowledge and discuss the neural circuit mechanisms by which female sexual behavior occurs in association with the ovulatory phase of …

Traversing The Bench To Bedside Journey For Inkt Cell Therapies, Julie O'Neal, Melissa Mavers, Reyka G Jayasinghe, John F Dipersio

2020-Current year OA Pubs

Invariant natural killer T (iNKT) cells are immune cells that harness properties of both the innate and adaptive immune system and exert multiple functions critical for the control of various diseases. Prevention of graft-versus-host disease (GVHD) by iNKT cells has been demonstrated in mouse models and in correlative human studies in which high iNKT cell content in the donor graft is associated with reduced GVHD in the setting of allogeneic hematopoietic stem cell transplants. This suggests that approaches to increase the number of iNKT cells in the setting of an allogeneic transplant may reduce GVHD. iNKT cells can also induce …

Systematic Computer-Aided Disulfide Design As A General Strategy To Stabilize Prefusion Class I Fusion Proteins, Karen J Gonzalez, Kevin C Yim, Jorge C G Blanco, Marina S Boukhvalova, Eva-Maria Strauch

2020-Current year OA Pubs

Numerous enveloped viruses, such as coronaviruses, influenza, and respiratory syncytial virus (RSV), utilize class I fusion proteins for cell entry. During this process, the proteins transition from a prefusion to a postfusion state, undergoing substantial and irreversible conformational changes. The prefusion conformation has repeatedly shown significant potential in vaccine development. However, the instability of this state poses challenges for its practical application in vaccines. While non-native disulfides have been effective in maintaining the prefusion structure, identifying stabilizing disulfide bonds remains an intricate task. Here, we present a general computational approach to systematically identify prefusion-stabilizing disulfides. Our method assesses the geometric …

Recarving The Future: Bridging Car T-Cell Therapy Gaps With Synthetic Biology, Engineering, And Economic Insights, Alaa Ali, John F Dipersio

2020-Current year OA Pubs

Chimeric antigen receptor (CAR) T-cell therapy has revolutionized the treatment of hematologic malignancies, offering remarkable remission rates in otherwise refractory conditions. However, its expansion into broader oncological applications faces significant hurdles, including limited efficacy in solid tumors, safety concerns related to toxicity, and logistical challenges in manufacturing and scalability. This review critically examines the latest advancements aimed at overcoming these obstacles, highlighting innovations in CAR T-cell engineering, novel antigen targeting strategies, and improvements in delivery and persistence within the tumor microenvironment. We also discuss the development of allogeneic CAR T cells as off-the-shelf therapies, strategies to mitigate adverse effects, and …

Cep120 Is Essential For Kidney Stromal Progenitor Cell Growth And Differentiation, Ewa Langner, Tao Cheng, Eirini Kefaloyianni, Charles Gluck, Baolin Wang, Moe R Mahjoub

2020-Current year OA Pubs

Mutations in genes that disrupt centrosome structure or function can cause congenital kidney developmental defects and lead to fibrocystic pathologies. Yet, it is unclear how defective centrosome biogenesis impacts renal progenitor cell physiology. Here, we examined the consequences of impaired centrosome duplication on kidney stromal progenitor cell growth, differentiation, and fate. Conditional deletion of the ciliopathy gene Cep120, which is essential for centrosome duplication, in the stromal mesenchyme resulted in reduced abundance of interstitial lineages including pericytes, fibroblasts and mesangial cells. These phenotypes were caused by a combination of delayed mitosis, activation of the mitotic surveillance pathway leading to apoptosis, …

Mapping Of A Hybrid Insulin Peptide In The Inflamed Islet Β-Cells From Nod Mice, Janet M Wenzlau, Orion J Peterson, Anthony N Vomund, James E Dilisio, Anita Hohenstein, Kathryn Haskins, Xiaoxiao Wan

2020-Current year OA Pubs

There is accumulating evidence that pathogenic T cells in T1D recognize epitopes formed by post-translational modifications of β-cell antigens, including hybrid insulin peptides (HIPs). The ligands for several CD4 T-cell clones derived from the NOD mouse are HIPs composed of a fragment of proinsulin joined to peptides from endogenous β-cell granule proteins. The diabetogenic T-cell clone BDC-6.9 reacts to a fragment of C-peptide fused to a cleavage product of pro-islet amyloid polypeptide (6.9HIP). In this study, we used a monoclonal antibody (MAb) to the 6.9HIP to determine when and where HIP antigens are present in NOD islets during disease progression …

A Structure-Function Analysis Of Hepatocyte Arginase 2 Reveals Mitochondrial Ureahydrolysis As A Determinant Of Glucose Oxidation, Yiming Zhang, Jiameng Sun, Henry D Wasserman, Joshua A Adams, Cassandra B Higgins, Shannon C Kelly, Louise Lantier, Brian J Debosch

2020-Current year OA Pubs

BACKGROUND & AIMS: Restoring hepatic and peripheral insulin sensitivity is critical to prevent or reverse metabolic syndrome and type 2 diabetes. Glucose homeostasis comprises in part the complex regulation of hepatic glucose production and insulin-mediated glucose uptake and oxidation in peripheral tissues. We previously identified hepatocyte arginase 2 (Arg2) as an inducible ureahydrolase that improves glucose homeostasis and enhances glucose oxidation in multiple obese, insulin-resistant models. We therefore examined structure-function determinants through which hepatocyte Arg2 governs systemic insulin action and glucose oxidation.

METHODS: To do this, we generated mice expressing wild-type murine Arg2, enzymatically inactive Arg2 (Arg2

RESULTS: We show …

Sirtuin3 Ensures The Metabolic Plasticity Of Neurotransmission During Glucose Deprivation, Anupama Tiwari, Arsalan Hashemiaghdam, Marissa A Laramie, Dario Maschi, Tristaan Haddad, Marion I Stunault, Carmen Bergom, Ali Javaheri, Vitaly Klyachko, Ghazaleh Ashrafi

2020-Current year OA Pubs

Neurotransmission is an energetically expensive process that underlies cognition. During intense electrical activity or dietary restrictions, the glucose level in the brain plummets, forcing neurons to utilize alternative fuels. However, the molecular mechanisms of neuronal metabolic plasticity remain poorly understood. Here, we demonstrate that glucose-deprived neurons activate the CREB and PGC1α transcriptional program, which induces expression of the mitochondrial deacetylase Sirtuin 3 (Sirt3) both in vitro and in vivo. We show that Sirt3 localizes to axonal mitochondria and stimulates mitochondrial oxidative capacity in hippocampal nerve terminals. Sirt3 plays an essential role in sustaining synaptic transmission in the absence of glucose …

Neurosteroids Mediate And Modulate The Effects Of Pro-Inflammatory Stimulation And Toll-Like Receptors On Hippocampal Plasticity And Learning, Yukitoshi Izumi, Kazuko A. O'Dell, Anil G. Cashikar, Steven M. Paul, Douglas F. Covey, Steven J. Mennerick, Charles F. Zorumski

2020-Current year OA Pubs

Pro-inflammatory changes contribute to multiple neuropsychiatric illnesses. Understanding how these changes are involved in illnesses and identifying strategies to alter inflammatory responses offer paths to potentially novel treatments. We previously found that acute pro-inflammatory stimulation with high (μg/ml) lipopolysaccharide (LPS) for 10-15 min dampens long-term potentiation (LTP) in the hippocampus and impairs learning. Effects of LPS involved non-canonical inflammasome signaling but were independent of toll-like receptor 4 (TLR4), a known LPS receptor. Low (ng/ml) LPS also inhibits LTP when administered for 2-4 h, and here we report that this LPS exposure requires TLR4. We also found that effects of low …

Stat1 Employs Myeloid Cell-Extrinsic Mechanisms To Regulate The Neutrophil Response And Provide Protection Against Invasive Klebsiella Pneumoniae Lung Infection, Shekina Gonzalez-Ferrer, Zeyu Xiong, Atish Gheware, Janet S Lee, Et Al.

2020-Current year OA Pubs

Klebsiella pneumoniae (KP) is an extracellular Gram-negative bacterium that causes infections in the lower respiratory and urinary tracts and the bloodstream. STAT1 is a master transcription factor that acts to maintain T cell quiescence under homeostatic conditions. Although STAT1 helps defend against systemic spread of acute KP intrapulmonary infection, whether STAT1 regulation of T cell homeostasis impacts pulmonary host defense during acute bacterial infection and injury is less clear. Using a clinical KP respiratory isolate and a pneumonia mouse model, we found that STAT1 deficiency led to an early neutrophil-dominant transcriptional profile and neutrophil recruitment in the lung preceding widespread …