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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 …

Ecdysoneless Overexpression Drives Mammary Tumorigenesis Through Upregulation Of C-Myc And Glucose Metabolism, Bhopal C. Mohapatra, Sameer Mirza, Aditya Bele, Channabasavaiah B. Gurumurthy, Mohsin Raza, Irfana Saleem, Matthew D. Storck, Aniruddha Sarkar, Sai Sundeep Kollala, Surendra K. Shukla, Siddesh Southekal, Kay-Uwe Wagner, Fang Qiu, Subodh M. Lele, Mansour A. Alsaleem, Emad A. Rakha, Chittibabu Guda, Pankaj K. Singh, Robert D. Cardiff, Hamid Band, Vimla Band

Journal Articles: Pharmacology & Experimental Neuroscience

Ecdysoneless (ECD) protein is essential for embryogenesis, cell-cycle progression, and cellular stress mitigation with an emerging role in mRNA biogenesis. We have previously shown that ECD protein as well as its mRNA are overexpressed in breast cancer and ECD overexpression predicts shorter survival in patients with breast cancer. However, the genetic evidence for an oncogenic role of ECD has not been established. Here, we generated transgenic mice with mammary epithelium-targeted overexpression of an inducible human ECD transgene (ECDTg). Significantly, ECDTg mice develop mammary hyperplasia, preneoplastic lesions, and heterogeneous tumors with occasional lung metastasis. ECDTg tumors exhibit epithelial to mesenchymal transition …

Exome Screening To Identify Loss-Of-Function Mutations In The Rhesus Macaque For Development Of Preclinical Models Of Human Disease, Adam Cornish, Robert M. Gibbs, Robert B. Norgren

Journal Articles: Genetics, Cell Biology & Anatomy

BACKGROUND: Exome sequencing has been utilized to identify genetic variants associated with disease in humans. Identification of loss-of-function mutations with exome sequencing in rhesus macaques (Macaca mulatta) could lead to valuable animal models of genetic disease. Attempts have been made to identify variants in rhesus macaques by aligning exome data against the rheMac2 draft genome. However, such efforts have been impaired due to the incompleteness and annotation errors associated with rheMac2. We wished to determine whether aligning exome reads against our new, improved rhesus genome, MacaM, could be used to identify high impact, loss-of-function mutations in rhesus macaques that would …

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 …

Emerging Trends For Radioimmunotherapy In Solid Tumors., Maneesh Jain, Suprit Gupta, Sukhwinder Kaur, Moorthy P. Ponnusamy, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

Due to its ability to target both known and occult lesions, radioimmunotherapy (RIT) is an attractive therapeutic modality for solid tumors. Poor tumor uptake and undesirable pharmacokinetics, however, have precluded the administration of radioimmunoconjugates at therapeutically relevant doses thereby limiting the clinical utility of RIT. In solid tumors, efficacy of RIT is further compromised by heterogeneities in blood flow, tumor stroma, expression of target antigens and radioresistance. As a result significant efforts have been invested toward developing strategies to overcome these impediments. Further, there is an emerging interest in exploiting short-range, high energy α-particle emitting radionuclides for the eradication of …

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, …

Mucin (Muc) Expression During Pancreatic Cancer Progression In Spontaneous Mouse Model: Potential Implications For Diagnosis And Therapy., Satyanarayana Rachagani, María P Torres, Sushil Kumar, Dhanya Haridas, Michael J. Baine, Muzafar A. Macha, Sukhwinder Kaur, Moorthy P. Ponnusamy, Parama Dey, Parthasarathy Seshacharyulu, Sonny L. Johansson, Maneesh Jain, Kay-Uwe Wagner, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

BACKGROUND: Pancreatic cancer (PC) is a lethal malignancy primarily driven by activated Kras mutations and characterized by the deregulation of several genes including mucins. Previous studies on mucins have identified their significant role in both benign and malignant human diseases including PC progression and metastasis. However, the initiation of MUC expression during PC remains unknown because of lack of early stage tumor tissues from PC patients.

METHODS: In the present study, we have evaluated stage specific expression patterns of mucins during mouse PC progression in (Kras(G12D);Pdx1-Cre (KC)) murine PC model from pancreatic intraepithelial neoplasia (PanIN) to pancreatic ductal adenocarcinoma (PDAC) …

Exosome-Mediated Shuttling Of Microrna-29 Regulates Hiv Tat And Morphine-Mediated Neuronal Dysfunction., Guoku Hu, H Yao, A D. Chaudhuri, Sowmya V. Yelamanchili, H Wen, P D. Cheney, Howard S. Fox, Shilpa J. Buch

Journal Articles: Pharmacology & Experimental Neuroscience

Neuronal damage is a hallmark feature of HIV-associated neurological disorders (HANDs). Opiate drug abuse accelerates the incidence and progression of HAND; however, the mechanisms underlying the potentiation of neuropathogenesis by these drugs remain elusive. Opiates such as morphine have been shown to enhance HIV transactivation protein Tat-mediated toxicity in both human neurons and neuroblastoma cells. In the present study, we demonstrate reduced expression of the tropic factor platelet-derived growth factor (PDGF)-B with a concomitant increase in miR-29b in the basal ganglia region of the brains of morphine-dependent simian immunodeficiency virus (SIV)-infected macaques compared with the SIV-infected controls. In vitro relevance …

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 …

Recent Advances On Skin-Resident Stem/Progenitor Cell Functions In Skin Regeneration, Aging And Cancers And Novel Anti-Aging And Cancer Therapies., Murielle Mimeault, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

Recent advances in skin-resident adult stem/progenitor cell research have revealed that these immature and regenerative cells with a high longevity provide critical functions in maintaining skin homeostasis and repair after severe injuries along the lifespan of individuals. The establishment of the functional properties of distinct adult stem/progenitor cells found in skin epidermis and hair follicles and extrinsic signals from their niches, which are deregulated during their aging and malignant transformation, has significantly improved our understanding on the etiopathogenesis of diverse human skin disorders and cancers. Particularly, enhanced ultraviolet radiation exposure, inflammation and oxidative stress and telomere attrition during chronological aging …

Mitochondrial Dna Mutations, Apoptosis, And The Misfolded Protein Response., Justin L. Mott, Dekui Zhang, Hans Peter Zassenhaus

Journal Articles: Biochemistry & Molecular Biology

Studies of transgenic mice with accelerated accumulation of mtDNA mutations specifically in the heart lead us to propose that apoptotic signaling and cell death is central to the pathogenesis of mtDNA mutations in aging. It is the cellular response to that apoptotic signaling and the organ?s compensatory response to a loss of cells that specify the phenotype of an accumulation of mtDNA mutations. In the heart, cardiomyocytes induce a vigorous anti-apoptotic, pro-survival response to counteract mitochondrial apoptotic signaling. The heart up-regulates contractility of remaining myocytes in order to maintain cardiac output. We hypothesize that mutant mitochondrial proteins originate apoptotic signaling …

Creation Of Non-Human Primate Neurogenetic Disease Models By Gene Targeting And Nuclear Transfer, Robert B. Norgren

Journal Articles: Genetics, Cell Biology & Anatomy

Genetically modified rhesus macaques are necessary because mouse models are not suitable for a number of important neurogenetic disorders; for example, Kallmann's syndrome, Lesch-Nyhan's disease and Ataxia-Telangiectasia. Mouse models may not be suitable because there may be no mouse ortholog of the human gene of interest, as is the case for Kallmann's syndrome, or because mutant mice do not exhibit the same phenotype observed in humans, as is the the case for Lesch-Nyhan's disease and Ataxia-Telangiectasia. Non-human primate models of neurogenetic diseases are expected to more closely resemble human diseases than existing mouse models. Genetically modified rhesus macaques can be …