Pathology Commons^™

Intrathecal (G4c2)149 Delivery In C9orf72-Deficient Mice Yields Mild Motor Dysfunction And Als/Ftd Pathological Hallmarks, Katelyn Russell, Amelia Shahrabi, Suleyman Akerman, Matthew D. Byrne, Jeffrey Rothstein, Davide Trotti, Brigid Jensen, Aaron Haeusler

Farber Institute for Neuroscience Faculty Papers

A repeat expansion in C9ORF72 is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), yet existing mouse models incompletely engage spinal regions implicated in disease. Here, an adeno-associated virus encoding (G4C2)149 repeats was delivered via neonatal intrathecal injection, achieving widespread CNS expression with robust spinal cord targeting. This approach was applied to mice with graded loss of endogenous C9orf72 to interrogate both gain- and loss-of-function mechanisms. Longitudinal motor, behavioral, and pathological analyses revealed that repeat expression primarily drives mild, progressive muscle weakness, whereas coordination deficits were largely genotype dependent. Subtle gait abnormalities and hyperactivity …

Progressive Cardiac Phenotypes And Reduced Reversibility From Long-Term Cugexp Rna Expression In A Dm1 Mouse Model, Rong-Chi Hu, Mohammadreza Tabary, Xander Ht Wehrens, Thomas A Cooper

Faculty, Staff and Students Publications

Myotonic dystrophy type 1 (DM1) is caused by an expanded CTG repeat in the DMPK gene, resulting in mutant transcripts that form expanded CUG (CUGexp) RNA foci and sequester muscleblind-like (MBNL) RNA-binding proteins. DM1 is multisystemic, with progressive worsening of disease manifestations in affected tissues. Disease progression is attributed to somatic expansion of the CTG repeats with age, resulting in production of CUGexp RNA with enhanced intrinsic toxicity due to increased MBNL sequestration. To determine the degree to which cardiac disease progression can occur independently of repeat expansion, we used a transgenic DM1 mouse model with inducible heart-specific expression of …

Mbnl Loss Of Function In Smooth Muscle As A Model For Myotonic Dystrophy Associated Gastrointestinal Dysmotility, Janel A M Peterson, Jesus A Frias, Andrew N Miller, Krishnakant G Soni, Yi Zhang, Zheng Xia, John W Day, Geoffrey A Preidis, Thomas A Cooper

Faculty, Staff and Students Publications

Myotonic dystrophy type 1 (DM1) is the most common adult-onset muscular dystrophy and severely affects multiple organ systems, including the brain, heart, skeletal muscle, and gastrointestinal (GI) tract. Despite 80% of individuals with DM1 experiencing GI dysfunction that affects their daily life, the mechanisms of GI dysmotility in DM1 remain an understudied aspect of the disease. DM1 is caused by a CTG repeat expansion in the DMPK gene that, when expressed as an expanded CUG repeat RNA, sequesters and reduces the activity of the muscleblind-like (MBNL) RNA-binding protein family. We developed a mouse line with conditional, smooth muscle-specific knockout of …

A Mouse Model Of Lipoatrophy Reveals Relationships Between Beige Fat Appearance And Female Fertility, Elizabeth S Anaya, William Dion, Pradip K Saha, Aaron R Cox, Evelyn De Groot, Avery A Ahmed, Jessica B Felix, Bokai Zhu, Stephanie A Pangas, Sean M Hartig

Faculty, Staff and Students Publications

White adipose tissue (WAT) performs vital metabolic and endocrine functions, but roles in female reproduction remain understudied and poorly understood. Here, we report that female mice experiencing progressive lipoatrophy after knockout of Ubc9 in adipocytes (Ubc9fKO) displayed disrupted estrous cycles, reduced ovarian reserve, and subfertility. During aging, female Ubc9fKO mice lose subcutaneous WAT more quickly than their male counterparts and weigh less than littermate controls. Subcutaneous WAT excised from female Ubc9fKO mice strongly enriched for thermogenesis genes generally associated with metabolic benefits. Female Ubc9fKO mice exhibited hypermetabolism and accumulated thermogenic, Uncoupling Protein 1-expressing beige fat cells in residual subcutaneous WAT …

Decorin Deficiency Promotes D-Galactose-Induced Skeletal Muscle Atrophy And Fibrosis By Regulating Itgb1/Akt/Mtor Signalling Pathway, Xiaoqin Luo, Mengxue Zhang, Lili Chen, Ruichang Wang, Jiabing Lian, Zhe Yang, Renato V. Iozzo, Jin Wang, Yan Zhang, Xiuli Bi

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: Primary sarcopenia is an age-associated disorder with progressive and generalised loss of skeletal muscle strength and mass. Skeletal muscle fibrosis is one of the significant pathological manifestations of age-associated sarcopenia. Decorin, a small dermatan-sulfate proteoglycan, participates in extracellular matrix assembly. In numerous studies, the involvement of decorin is not restricted to matrix structural proteins, and it also affects a diverse variety of biological functions like cell growth, adhesion, migration, proliferation and differentiation. Additionally, it modulates the process of inflammation and fibrillogenesis. Based on these preclinical evidences, we hypothesised that decorin may potentially play an important role in skeletal muscles …

Protein Kinase Rock1 Activates Mitochondrial Fission Linking To Oxidative Stress And Muscle Atrophy, Meijun Si, Jihong Chen, Rizhen Yu, Hongchun Lin, Feng Li, Sungyun Jung, Sandhya S Thomas, Farhard R Danesh, Yanlin Wang, Hui Peng, Zhaoyong Hu

Faculty, Staff and Students Publications

Introduction: Chronic kidney disease (CKD) is associated with protein-energy wasting, characterized by a reduction in muscle mass and strength. Although mitochondrial dysfunction and oxidative stress are implicated in the pathogenesis of muscle wasting, underlying mechanisms remain unclear.

Methods: Here, we used transcriptomic analysis, metabolomics analyses, and mouse gene manipulation to investigate the effects of mitochondrial plasticity and oxidative stress on muscle wasting the subtotal nephrectomy mouse models of CKD. The mice with CKD were age- and sex-matched to sham-operated controls.

Results: Through these approaches, Rho-associated kinase ROCK1 emerged as a key molecule responsible for the observed mitochondrial fission and oxidative …

Dissecting The Effect Of Mitochondrial Bcat Inhibition In Methylmalonic Acidemia, Madeline G Hemmingsen, Guo-Fang Zhang, Yunhan Ma, Hannah Marchuk, Kalyani R Patel, Tong Chen, Xinning Li, Mark Chapman, Sabrina Collias, Dolores H Lopez-Terrada, James Beasley, Ashlee R Stiles, Randy J Chandler, Charles P Venditti, Sarah P Young, Mercedes Barzi, Beatrice Bissig-Choisat, Doug Krafte, Christopher B Newgard, Karl-Dimiter Bissig

Faculty, Staff and Students Publications

Methylmalonic acidemia (MMA) is a severe metabolic disorder affecting multiple organs because of a distal block in branched-chain amino acid (BCAA) catabolism. Standard of care is limited to protein restriction and supportive care during metabolic decompensation. Severe cases require liver/kidney transplantation, and there is a clear need for better therapy. Here, we investigated the effects of a small molecule branched-chain amino acid transaminase (BCAT) inhibitor in human MMA hepatocytes and an MMA mouse model. Mitochondrial BCAT is the first step in BCAA catabolism, and reduction of flux through an early enzymatic step is successfully used in other amino acid metabolic …

Targeting Bard1 Suppresses A Myc-Dependent Transcriptional Program And Tumor Growth In Pancreatic Ductal Adenocarcinoma, Sohum Patel, Eleanor Jenkins, Rutuj P. Kusurkar, Sherry Lee, Wei Jiang, Avinoam Nevler, Matthew Mccoy, Michael J. Pishvaian, Rosalie C. Sears, Jonathan R. Brody, Charles J. Yeo, Aditi Jain

Department of Surgery Faculty Papers

Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest cancers demanding better and more effective therapies. BARD1 or BRCA1-Associated -Ring Domain-1 plays a pivotal role in homologous recombination repair (HRR). However, its function and the underlying molecular mechanisms in PDAC are still not fully elucidated. Here, we demonstrate that BARD1 is overexpressed in PDAC and its genetic inhibition suppresses c-Myc and disrupts c-Myc dependent transcriptional program. Mechanistically, BARD1 stabilizes c-Myc through ubiquitin-proteasome system by regulating FBXW7. Importantly, targeting BARD1 using either siRNAs or CRISPR/Cas9 deletion blocks PDAC growth in vitro and in vivo, without any signs of toxicity to mice. …

Intestinal Epithelial Serotonin As A Novel Target For Treating Disorders Of Gut-Brain Interaction And Mood, Lin Y Hung, Nuno D Alves, Andrew Del Colle, Ardesheer Talati, Sarah A Najjar, Virginie Bouchard, Virginie Gillet, Yan Tong, Zixing Huang, Kirsteen N Browning, Jialiang Hua, Ying Liu, James O Woodruff, Daniel Juarez, Melissa Medina, Jonathan Posner, Raquel Tonello, Nazli Yalcinkaya, Narek Israelyan, Roey Ringel, Letao Yang, Kam W Leong, Mu Yang, Ji Ying Sze, Tor Savidge, Jay Gingrich, Robert J Shulman, Michael D Gershon, Annie Ouellet, Larissa Takser, Mark S Ansorge, Kara Gross Margolis

Faculty, Staff and Students Publications

Background & aims: Mood disorders and disorders of gut-brain interaction (DGBI) are highly prevalent, commonly comorbid, and lack fully effective therapies. Although selective serotonin reuptake inhibitors (SSRIs) are first-line pharmacological treatments for these disorders, they may impart adverse effects, including anxiety, anhedonia, dysmotility, and, in children exposed in utero, an increased risk of cognitive, mood, and gastrointestinal disorders. SSRIs act systemically to block the serotonin reuptake transporter and enhance serotonergic signaling in the brain, intestinal epithelium, and enteric neurons. Yet, the compartments that mediate the therapeutic and adverse effects of SSRIs are unknown, as is whether gestational SSRI exposure directly …

Sialidase Fusion Protein Protects Against Influenza Infection In A Cigarette Smoke-Induced Model Of Copd, Cheng-Yen Chang, Dominique Armstrong, John M Knight, Trevor V Gale, Stephen Hawley, Max Wang, Nancy Chang, David B Corry, Farrah Kheradmand

Faculty, Staff and Students Publications

First- and secondhand smokers are at an increased risk for influenza virus (IFV)-related respiratory failure and death. Despite approved influenza antiviral treatments, there is an unmet need for treatments that can improve outcomes in populations at risk for respiratory failure, including tobacco users with Chronic Obstructive Pulmonary Disease (COPD). Here we show that the sialidase fusion protein, DAS181, reduced viral burden, mitigated inflammation, and attenuated lung function loss, consistent with broad-spectrum anti-influenza responses in a mouse model of COPD and IFV-A infection. Treatment with DAS181 reprogramed the sialic acid-binding immunoglobulin-like lectins (Siglecs) in alveolar macrophages, increased expression of phagocytic marker …

Cd4+ T Cell-Innate Immune Crosstalk Is Critical During Staphylococcus Aureus Craniotomy Infection, Gunjan Kak, Zachary A. Van Roy, Rachel W. Fallet, Lee E. Korshoj, Tammy Kielian

Journal Articles: Pathology and Microbiology

Access to the brain for treating neurological sequalae requires a craniotomy, which can be complicated by infection. Staphylococcus aureus accounts for half of craniotomy infections, increasing morbidity in a medically fragile patient population. T cells preferentially traffic to the brain during craniotomy infection; however, their functional importance is unknown. Using a mouse model of S. aureus craniotomy infection, CD4+ T cells were critical for bacterial containment, as treatment of WT animals with anti-CD4 exacerbated infection that was similar to phenotypes in Rag1-/- mice. Single-cell RNA-Seq (scRNA-Seq) revealed transcriptional heterogeneity in brain CD3+ infiltrates, with CD4+ cells most prominent that displayed …

Extracellular Adherence Proteins Reduce Matrix Porosity And Enhance Staphylococcus Aureus Biofilm Survival During Prosthetic Joint Infection, Mohini Bhattacharya, Tyler D. Scherr, Jessica Lister, Tammy Kielian, Alexander R. Horswill

Journal Articles: Pathology and Microbiology

Biofilms are a cause of chronic, non-healing infections. Staphylococcus aureus is a proficient biofilm-forming pathogen commonly isolated from prosthetic joint infections that develop following primary arthroplasty. Extracellular adherence protein (Eap), previously characterized in planktonic or non-biofilm populations as being an adhesin and immune evasion factor, was recently identified in the exoproteome of S. aureus biofilms. This work demonstrates that Eap and its two functionally orphaned homologs EapH1 and EapH2 contribute to biofilm structure and prevent macrophage invasion and phagocytosis in these communities. Biofilms unable to express Eap proteins demonstrated increased porosity and reduced biomass. We describe the role of Eap …

Initiation Of Metformin In Early Pregnancy Results In Fetal Bioaccumulation, Growth Restriction, And Renal Dysmorphology In A Primate Model, Erin Bolte, Tyler Dean, Brandon Garcia, Maxim D Seferovic, Kristin Sauter, Gwendolynn Hummel, Matthew Bucher, Feng Li, John Hicks, Xuan Qin, Melissa A Suter, Enrico R Barrozo, Michael Jochum, Cynthia Shope, Jacob E Friedman, Maureen Gannon, Stephanie R Wesolowski, Carrie E Mccurdy, Paul Kievit, Kjersti M Aagaard

Faculty, Staff and Students Publications

Background: In recent years, pragmatic metformin use in pregnancy has stretched to include prediabetes mellitus, type 2 diabetes mellitus, gestational diabetes mellitus, and (most recently) preeclampsia. However, with its expanded use, concerns of unintended harm have been raised.

Objective: This study developed an experimental primate model and applied ultrahigh performance liquid chromatography coupled to triple-quadrupole mass spectrometry for direct quantitation of maternal and fetal tissue metformin levels with detailed fetal biometry and histopathology.

Study design: Within 30 days of confirmed conception (defined as early pregnancy), 13 time-bred (timed-mated breeding) Rhesus dams with pregnancies designated for fetal necropsy were initiated on …

Immunoregulatory Properties Of Immune Cells That Associate With The Lens Capsule Surface During Acute And Resolution Phases Of Experimental Autoimmune Uveitis, Phuong M. Le, Mary J. Mattapallil, Rachel R. Caspi, Mary Ann Stepp, A. Sue Menko

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Inflammation in the eye is tightly regulated to prevent vision impairment and irreversible blindness. Emerging evidence shows that immune cells are specifically recruited to the lens capsule in response to autoimmune uveitis, yet the potential that they have a role in regulating this inflammatory disease remained unexplored. Here, an immunolocalization approach combined with high-resolution confocal microscopy was used to investigate whether the immune cells that become stably associated with the lens capsule in the eyes of C57BL/6J mice with experimental autoimmune uveitis (EAU) have an immunoregulatory phenotype. These studies revealed that during the acute phase of uveitis, at day 18 …

C1q Is Elevated During Chronic Staphylococcus Epidermidis Central Nervous System Catheter Infection, Matthew K. Beaver, Lara Bergdolt, Anna Dunaevsky, Tammy Kielian, Gwenn Skar

Journal Articles: Pathology and Microbiology

INTRODUCTION: Significant neurologic morbidity is caused by pediatric cerebrospinal fluid (CSF) shunt infections. The underlying mechanisms leading to impaired school performance and increased risk of seizures are unknown, however, a better understanding of these mechanisms may allow us to temper their consequences. Recent evidence has demonstrated important roles for complement proteins in neurodevelopment and neuroinflammation.

METHODS: We examined complement activation throughout

RESULTS: We found that MASP2 predominated early in catheter infection, but that Factor B was elevated at intermediate time points. Unexpectedly C1q was elevated at late timepoints when bacterial burdens were low or undetectable. Based on these findings and …

Tetracycline And Oxacillin Act Synergistically On Biofilms And Display Increased Efficacy In Vivo Against Staphylococcus Aureus, Amy K. Tooke, Rebecca E. Hodges, Josie F. Pyrah, Kenneth W. Bayles, Stephen A. Renshaw, Simon J. Foster

Journal Articles: Pathology and Microbiology

Oxacillin (bactericidal) and tetracycline (bacteriostatic) are clinically relevant antibiotics that are routinely prescribed to treat Staphylococcus aureus infections but not conventionally used in combination. There is an urgent need for treatment regimens that can act upon biofilms during infection, associated with chronic infections on indwelling devices, as well as acute planktonic (systemic) infection. Here we show that in an in vitro model oxacillin and tetracycline act synergistically against S. aureus UAMS-1 biofilms, reducing the concentration of both antibiotics necessary to eradicate an established biofilm. Using an in vivo zebrafish larval infection model with S. aureus NewHG, they display improved bacterial …

Increase In Hnrnpa1 Expression Suffices To Kill Motor Neurons In Transgenic Rats, Xionghao Liu, Tingting Zhang, Qinxue Wu, Cao Huang, Xu-Gang Xia, Hongxia Zhou, Bo Huang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

A dominant mutation in hnRNPA1 causes amyotrophic lateral sclerosis (ALS), but it is not known whether this mutation leads to motor neuron death through increased or decreased function. To elucidate the relationship between pathogenic hnRNPA1 mutation and its native function, we created novel transgenic rats that overexpressed wildtype rat hnRNPA1 exclusively in motor neurons. This targeted expression of wildtype hnRNPA1 caused severe motor neuron loss and subsequent denervation muscle atrophy in transgenic rats that recapitulated the characteristics of ALS. These findings demonstrate that the augmentation of hnRNPA1 expression suffices to trigger motor neuron degeneration and the manifestation of ALS-like phenotypes. …

Systemic Ablation Of Camkk2 Impairs Metastatic Colonization And Improves Insulin Sensitivity In Tramp Mice: Evidence For Cancer Cell-Extrinsic Camkk2 Functions In Prostate Cancer, Thomas L Pulliam, Dominik Awad, Jenny J Han, Mollianne M Murray, Jeffrey J Ackroyd, Pavithr Goli, Jonathan S Oakhill, John W Scott, Michael M Ittmann, Daniel E Frigo

Faculty, Staff and Students Publications

Despite early studies linking calcium-calmodulin protein kinase kinase 2 (CAMKK2) to prostate cancer cell migration and invasion, the role of CAMKK2 in metastasis in vivo remains unclear. Moreover, while CAMKK2 is known to regulate systemic metabolism, whether CAMKK2's effects on whole-body metabolism would impact prostate cancer progression and/or related comorbidities is not known. Here, we demonstrate that germline ablation of

Staphylococcus Aureus Biofilms Induce Macrophage Dysfunction Through Leukocidin Ab And Alpha-Toxin., Tyler D. Scherr, Mark L. Hanke, Ouwen Huang, David B.A. James, Alexander R. Horswill, Kenneth W. Bayles, Paul D. Fey, Victor J. Torres, Tammy Kielian

Journal Articles: Pathology and Microbiology

UNLABELLED: The macrophage response to planktonic Staphylococcus aureus involves the induction of proinflammatory microbicidal activity. However, S. aureus biofilms can interfere with these responses in part by polarizing macrophages toward an anti-inflammatory profibrotic phenotype. Here we demonstrate that conditioned medium from mature S. aureus biofilms inhibited macrophage phagocytosis and induced cytotoxicity, suggesting the involvement of a secreted factor(s). Iterative testing found the active factor(s) to be proteinaceous and partially agr-dependent. Quantitative mass spectrometry identified alpha-toxin (Hla) and leukocidin AB (LukAB) as critical molecules secreted by S. aureus biofilms that inhibit murine macrophage phagocytosis and promote cytotoxicity. A role for Hla …

Expression Of Suppressor Of Cytokine Signaling 1 (Socs1) Impairs Viral Clearance And Exacerbates Lung Injury During Influenza Infection., Keer Sun, Sharon Salmon, Vijaya Kumar Yajjala, Christopher Bauer, Dennis W. Metzger

Journal Articles: Pathology and Microbiology

Suppressor of cytokine signaling (SOCS) proteins are inducible feedback inhibitors of cytokine signaling. SOCS1-/- mice die within three weeks postnatally due to IFN-γ-induced hyperinflammation. Since it is well established that IFN-γ is dispensable for protection against influenza infection, we generated SOCS1-/-IFN-γ-/- mice to determine whether SOCS1 regulates antiviral immunity in vivo. Here we show that SOCS1-/-IFN-γ-/- mice exhibited significantly enhanced resistance to influenza infection, as evidenced by improved viral clearance, attenuated acute lung damage, and consequently increased survival rates compared to either IFN-γ-/- or WT animals. Enhanced viral clearance in SOCS1-/-IFN-γ-/- mice coincided with a rapid onset of adaptive immune …

Transformation Of Human Cathelicidin Ll-37 Into Selective, Stable, And Potent Antimicrobial Compounds., Guangshun Wang, Mark L. Hanke, Biswajit Mishra, Tamara Lushnikova, Cortney E. Heim, Vinai Chittezham Thomas, Kenneth W. Bayles, Tammy Kielian

Journal Articles: Pathology and Microbiology

This Letter reports a family of novel antimicrobial compounds obtained by combining peptide library screening with structure-based design. Library screening led to the identification of a human LL-37 peptide resistant to chymotrypsin. This d-amino-acid-containing peptide template was active against Escherichia coli but not methicillin-resistant Staphylococcus aureus (MRSA). It possesses a unique nonclassic amphipathic structure with hydrophobic defects. By repairing the hydrophobic defects, the peptide (17BIPHE2) gained activity against the ESKAPE pathogens, including Enterococcus faecium, S. aureus, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa, and Enterobacter species. In vitro, 17BIPHE2 could disrupt bacterial membranes and bind to DNA. In vivo, the peptide …

Ccpa Regulates Arginine Biosynthesis In Staphylococcus Aureus Through Repression Of Proline Catabolism., Austin S. Nuxoll, Steven M. Halouska, Marat Sadykov, Mark L. Hanke, Kenneth W. Bayles, Tammy Kielian, Robert Powers, Paul D. Fey

Journal Articles: Pathology and Microbiology

Staphylococcus aureus is a leading cause of community-associated and nosocomial infections. Imperative to the success of S. aureus is the ability to adapt and utilize nutrients that are readily available. Genomic sequencing suggests that S. aureus has the genes required for synthesis of all twenty amino acids. However, in vitro experimentation demonstrates that staphylococci have multiple amino acid auxotrophies, including arginine. Although S. aureus possesses the highly conserved anabolic pathway that synthesizes arginine via glutamate, we demonstrate here that inactivation of ccpA facilitates the synthesis of arginine via the urea cycle utilizing proline as a substrate. Mutations within putA, rocD, …

Deciphering Mechanisms Of Staphylococcal Biofilm Evasion Of Host Immunity., Mark L. Hanke, Tammy Kielian

Journal Articles: Pathology and Microbiology

Biofilms are adherent communities of bacteria contained within a complex matrix. Although host immune responses to planktonic staphylococcal species have been relatively well-characterized, less is known regarding immunity to staphylococcal biofilms and how they modulate anti-bacterial effector mechanisms when organized in this protective milieu. Previously, staphylococcal biofilms were thought to escape immune recognition on the basis of their chronic and indolent nature. Instead, we have proposed that staphylococcal biofilms skew the host immune response away from a proinflammatory bactericidal phenotype toward an anti-inflammatory, pro-fibrotic response that favors bacterial persistence. This possibility is supported by recent studies from our laboratory using …

Il-1ri (Interleukin-1 Receptor Type I) Signalling Is Essential For Host Defence And Hemichannel Activity During Acute Central Nervous System Bacterial Infection., Juan Xiong, Maria Burkovetskaya, Nikolay Karpuk, Tammy Kielian

Journal Articles: Pathology and Microbiology

Staphylococcus aureus is a common aetiological agent of bacterial brain abscesses. We have previously established that a considerable IL-1 (interleukin-1) response is elicited immediately following S. aureus infection, where the cytokine can exert pleiotropic effects on glial activation and blood-brain barrier permeability. To assess the combined actions of IL-1α and IL-1β during CNS (central nervous system) infection, host defence responses were evaluated in IL-1RI (IL-1 receptor type I) KO (knockout) animals. IL-1RI KO mice were exquisitely sensitive to intracerebral S. aureus infection, as demonstrated by enhanced mortality rates and bacterial burdens within the first 24 h following pathogen exposure compared …

Tlr4 Mutation Reduces Microglial Activation, Increases Aβ Deposits And Exacerbates Cognitive Deficits In A Mouse Model Of Alzheimer's Disease, Min Song, Jingji Jin, Jinghong Kou, Abhinandan Pattanayak, Jamaal Rehman, Hong-Duck Kim, Ken-Ichiro Fukuchi

NYMC Faculty Publications

BACKGROUND: Amyloid plaques, a pathological hallmark of Alzheimer's disease (AD), are accompanied by activated microglia. The role of activated microglia in the pathogenesis of AD remains controversial: either clearing Aβ deposits by phagocytosis or releasing proinflammatory cytokines and cytotoxic substances. Microglia can be activated via toll-like receptors (TLRs), a class of pattern-recognition receptors in the innate immune system. We previously demonstrated that an AD mouse model homozygous for a loss-of-function mutation of TLR4 had increases in Aβ deposits and buffer-soluble Aβ in the brain as compared with a TLR4 wild-type AD mouse model at 14-16 months of age. However, it …

Hibernation-Like State Induced By An Opioid Peptide Protects Against Experimental Stroke, Cesar V. Borlongan, Teruo Hayashi, Peter R. Oeltgen, Tsung-Ping Su, Yun Wang

Pathology and Laboratory Medicine Faculty Publications

BACKGROUND: Delta opioid peptide [D-ala2,D-leU5]enkephalin (DADLE) induces hibernation in summer ground squirrels, and enhances preservation and survival of isolated or transplanted lungs and hearts. In the present study, we investigated the protective effect of DADLE in the central nervous system.

RESULTS: Adult Sprague-Dawley rats were pretreated with DADLE (4 mg/kg every 2 h x 4 injections, i.p.) or saline prior to unilateral occlusion of the middle cerebral artery (MCA). Daily behavioral tests revealed that ischemic animals treated with DADLE did not show any significant behavioral dysfunctions compared with saline-treated ischemic animals. Opioid antagonists only transiently inhibited the protective effect of …

The Cns Role Of Toll-Like Receptor 4 In Innate Neuroimmunity And Painful Neuropathy, Flobert Y. Tanga, Nancy Nutile-Mcmenemy, Joyce A. Deleo

Dartmouth Scholarship

Neuropathic pain remains a prevalent and persistent clinical problem because of our incomplete understanding of its pathogenesis. This study demonstrates for the first time, to our knowledge, a critical role for CNS innate immunity by means of microglial Toll-like receptor 4 (TLR4) in the induction phase of behavioral hypersensitivity in a mouse and rat model of neuropathy. We hypothesized that after L5 nerve transection, CNS neuroimmune activation and subsequent cytokine expression are triggered by the stimulation of microglial membrane-bound TLR4. To test this hypothesis, experiments were undertaken to assess tactile and thermal hypersensitivity in genetically altered (i.e., TLR4 knockout and …