scholarly journals DNA Blocks the Lethal Effect of Human Beta-Defensin 2 Against Neisseria meningitidis

2021 ◽  
Vol 12 ◽  
Author(s):  
Gabriela M. Wassing ◽  
Kenny Lidberg ◽  
Sara Sigurlásdóttir ◽  
Jonas Frey ◽  
Kristen Schroeder ◽  
...  
Keyword(s):  
Neisseria Meningitidis ◽  
Membrane Integrity ◽  
Lethal Effect ◽  
Extracellular Dna ◽  
Dependent Manner ◽  
Mobility Shift ◽  
Planktonic Bacteria ◽  
Life Threatening ◽  
Dose Dependent ◽  
Lethal Doses

Neisseria meningitidis is a gram-negative bacterium that often asymptomatically colonizes the human nasopharyngeal tract. These bacteria cross the epithelial barrier can cause life-threatening sepsis and/or meningitis. Antimicrobial peptides are one of the first lines of defense against invading bacterial pathogens. Human beta-defensin 2 (hBD2) is an antimicrobial peptide with broad antibacterial activity, although its mechanism of action is poorly understood. Here, we investigated the effect of hBD2 on N. meningitidis. We showed that hBD2 binds to and kills actively growing meningococcal cells. The lethal effect was evident after 2 h incubation with the peptide, which suggests a slow killing mechanism. Further, the membrane integrity was not changed during hBD2 treatment. Incubation with lethal doses of hBD2 decreased the presence of diplococci; the number and size of bacterial microcolonies/aggregates remained constant, indicating that planktonic bacteria may be more susceptible to the peptide. Meningococcal DNA bound hBD2 in mobility shift assays and inhibited the lethal effect of hBD2 in a dose-dependent manner both in suspension and biofilms, supporting the interaction between hBD2 and DNA. Taken together, the ability of meningococcal DNA to bind hBD2 opens the possibility that extracellular DNA due to bacterial lysis may be a means of N. meningitidis to evade immune defenses.

scholarly journals Antifungal activity of dendritic cell lysosomal proteins against Cryptococcus neoformans

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Benjamin N. Nelson ◽  
Savannah G. Beakley ◽  
Sierra Posey ◽  
Brittney Conn ◽  
Emma Maritz ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Cryptococcus Neoformans ◽  
Mammalian Cells ◽  
Cysteine Proteases ◽  
Dependent Manner ◽  
Life Threatening ◽  
Opportunistic Fungal Pathogen ◽  
Dose Dependent ◽  
Lysosomal Proteins

AbstractCryptococcal meningitis is a life-threatening disease among immune compromised individuals that is caused by the opportunistic fungal pathogen Cryptococcus neoformans. Previous studies have shown that the fungus is phagocytosed by dendritic cells (DCs) and trafficked to the lysosome where it is killed by both oxidative and non-oxidative mechanisms. While certain molecules from the lysosome are known to kill or inhibit the growth of C. neoformans, the lysosome is an organelle containing many different proteins and enzymes that are designed to degrade phagocytosed material. We hypothesized that multiple lysosomal components, including cysteine proteases and antimicrobial peptides, could inhibit the growth of C. neoformans. Our study identified the contents of the DC lysosome and examined the anti-cryptococcal properties of different proteins found within the lysosome. Results showed several DC lysosomal proteins affected the growth of C. neoformans in vitro. The proteins that killed or inhibited the fungus did so in a dose-dependent manner. Furthermore, the concentration of protein needed for cryptococcal inhibition was found to be non-cytotoxic to mammalian cells. These data show that many DC lysosomal proteins have antifungal activity and have potential as immune-based therapeutics.

scholarly journals Larva of greater wax moth Galleria mellonella is a suitable alternative host for the fish pathogen Francisella noatunensis subsp. orientalis

2019 ◽  
Author(s):  
Winarti Achmad Sarmin Djainal ◽  
Khalid Shahin ◽  
Alexandra Adams ◽  
Andrew Desbois
Keyword(s):  
Galleria Mellonella ◽  
Dependent Manner ◽  
Alternative Host ◽  
Prevention Measures ◽  
Suitable Alternative ◽  
Treatment And Prevention ◽  
Greater Wax Moth ◽  
Important Food Source ◽  
Dose Dependent ◽  
Lethal Doses

Abstract Background Francisella noatunensis subsp. orientalis (Fno) is the etiological agent of francisellosis in cultured warm water fish, such as tilapia. Antibiotics are administered to treat the disease but a better understanding of Fno infection biology will inform improved treatment and prevention measures. However, studies with native hosts are costly and considerable benefits would derive from access to a practical alternative host. Here, larvae of Galleria mellonella were assessed for suitability to study Fno virulence. Results Larvae were killed by Fno in a dose-dependent manner but the insects could be rescued from lethal doses of bacteria by antibiotic therapy. Infection progression was assessed by histopathology (haematoxylin and eosin staining, Gram Twort and immunohistochemistry) and enumeration of bacteria recovered from the larval haemolymph on selective agar. Fno was phagocytosed and could survive intracellularly, which is consistent with observations in fish. Virulence of five Fno isolates showed strong agreement between G. mellonella and red Nile tilapia hosts. Conclusions This study shows that an alternative host, G. mellonella, can be applied to understand Fno infections, which will assist efforts to identify solutions to piscine francisellosis thus securing the livelihoods of tilapia farmers worldwide and ensuring the production of this important food source.

scholarly journals Compound and Dose-Dependent Effects of Two Neonicotinoid Pesticides on Honey Bee (Apis mellifera) Metabolic Physiology

Insects ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 18 ◽  
Author(s):  
Steven C. Cook
Keyword(s):  
Honey Bee ◽  
Low Dose ◽  
Oral Exposure ◽  
High Dose ◽  
Dependent Manner ◽  
Bee Colony ◽  
Metabolic Physiology ◽  
Neonicotinoid Pesticides ◽  
Dose Dependent ◽  
Lethal Doses

Use of neonicotinoid pesticides is now ubiquitous, and consequently non-targeted arthropods are exposed to their residues at sub-lethal doses. Exposure to these neurotoxins may be a major contributor to poor honey bee colony health. Few studies have explored how sub lethal exposure to neonicotinoids affects honey bee metabolic physiology, including nutritional and energetic homeostasis, both of which are important for maintaining colony health. Reported here are results from a study of chronic oral exposure of honey bees to two sub lethal concentrations of clothianidin and imidacloprid. Neonicotinoids altered important aspects of honey bee nutritional and metabolic physiology in a compound and dose-dependent manner; both compounds at low doses reduced honey bee body weight. Low-dose clothianidin exposure resulted in bees having protein, lipids, carbohydrates, and glycogen levels similar to newly emerged bees. High-dose clothianidin exposure lowered lipids and glycogen content of bees. High-dose imidacloprid exposure resulted in bees having depressed metabolic rate. Low-dose imidacloprid exposure resulted in bees consuming low and high levels of protein and carbohydrate rich foods, respectively. Results suggest neonicotinoids interfere with honey bee endocrine neurophysiological pathways. Compound and dose-dependent effects might represent respective chemical structural differences determining an observed effect, and thresholds of compound effects on honey bee physiology.

scholarly journals Electron Beam Irradiation Dose Dependently Damages theBacillusSpore Coat and Spore Membrane

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
S. E. Fiester ◽  
S. L. Helfinstine ◽  
J. C. Redfearn ◽  
R. M. Uribe ◽  
C. J. Woolverton
Keyword(s):  
Electron Beam ◽  
Structural Damage ◽  
Membrane Damage ◽  
Membrane Integrity ◽  
Effective Control ◽  
Spore Coat ◽  
Dependent Manner ◽  
Limited Data ◽  
Effective Electron ◽  
Dose Dependent

Effective control of spore-forming bacilli begs suitable physical or chemical methods. While many spore inactivation techniques have been proven effective, electron beam (EB) irradiation has been frequently chosen to eradicateBacillusspores. Despite its widespread use, there are limited data evaluating the effects of EB irradiation onBacillusspores. To study this,B. atrophaeusspores were purified, suspended in sterile, distilled water, and irradiated with EB (up to 20 kGy). Irradiated spores were found (1) to contain structural damage as observed by electron microscopy, (2) to have spilled cytoplasmic contents as measured by spectroscopy, (3) to have reduced membrane integrity as determined by fluorescence cytometry, and (4) to have fragmented genomic DNA as measured by gel electrophoresis, all in a dose-dependent manner. Additionally, cytometry data reveal decreased spore size, increased surface alterations, and increased uptake of propidium iodide, with increasing EB dose, suggesting spore coat alterations with membrane damage, prior to loss of spore viability. The present study suggests that EB irradiation of spores in water results in substantial structural damage of the spore coat and inner membrane, and that, along with DNA fragmentation, results in dose-dependent spore inactivation.

scholarly journals Dual mRNA therapy restores metabolic function in long-term studies in mice with propionic acidemia

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Lei Jiang ◽  
Ji-Sun Park ◽  
Ling Yin ◽  
Rodrigo Laureano ◽  
Eric Jacquinet ◽  
...  
Keyword(s):  
Genetic Disorders ◽  
Propionic Acidemia ◽  
Repeat Dose ◽  
Dependent Manner ◽  
Messenger Rnas ◽  
Enzyme Replacement ◽  
Life Threatening ◽  
Mrna Technology ◽  
Dose Dependent

Abstract Propionic acidemia/aciduria (PA) is an ultra-rare, life-threatening, inherited metabolic disorder caused by deficiency of the mitochondrial enzyme, propionyl-CoA carboxylase (PCC) composed of six alpha (PCCA) and six beta (PCCB) subunits. We herein report an enzyme replacement approach to treat PA using a combination of two messenger RNAs (mRNAs) (dual mRNAs) encoding both human PCCA (hPCCA) and PCCB (hPCCB) encapsulated in biodegradable lipid nanoparticles (LNPs) to produce functional PCC enzyme in liver. In patient fibroblasts, dual mRNAs encoded proteins localize in mitochondria and produce higher PCC enzyme activity vs. single (PCCA or PCCB) mRNA alone. In a hypomorphic murine model of PA, dual mRNAs normalize ammonia similarly to carglumic acid, a drug approved in Europe for the treatment of hyperammonemia due to PA. Dual mRNAs additionally restore functional PCC enzyme in liver and thus reduce primary disease-associated toxins in a dose-dependent manner in long-term 3- and 6-month repeat-dose studies in PA mice. Dual mRNAs are well-tolerated in these studies with no adverse findings. These studies demonstrate the potential of mRNA technology to chronically administer multiple mRNAs to produce large complex enzymes, with applicability to other genetic disorders.

scholarly journals Larva of greater wax moth Galleria mellonella is a suitable alternative host for the fish pathogen Francisella noatunensis subsp. orientalis

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Winarti Achmad Sarmin Djainal ◽  
Khalid Shahin ◽  
Matthijs Metselaar ◽  
Alexandra Adams ◽  
Andrew P. Desbois
Keyword(s):  
Galleria Mellonella ◽  
Dependent Manner ◽  
Alternative Host ◽  
Prevention Measures ◽  
Suitable Alternative ◽  
Treatment And Prevention ◽  
Greater Wax Moth ◽  
Important Food Source ◽  
Dose Dependent ◽  
Lethal Doses

Abstract Background Francisella noatunensis subsp. orientalis (Fno) is the etiological agent of francisellosis in cultured warm water fish, such as tilapia. Antibiotics are administered to treat the disease but a better understanding of Fno infection biology will inform improved treatment and prevention measures. However, studies with native hosts are costly and considerable benefits would derive from access to a practical alternative host. Here, larvae of Galleria mellonella were assessed for suitability to study Fno virulence. Results Larvae were killed by Fno in a dose-dependent manner but the insects could be rescued from lethal doses of bacteria by antibiotic therapy. Infection progression was assessed by histopathology (haematoxylin and eosin staining, Gram Twort and immunohistochemistry) and enumeration of bacteria recovered from the larval haemolymph on selective agar. Fno was phagocytosed and could survive intracellularly, which is consistent with observations in fish. Virulence of five Fno isolates showed strong agreement between G. mellonella and red Nile tilapia hosts. Conclusions This study shows that an alternative host, G. mellonella, can be applied to understand Fno infections, which will assist efforts to identify solutions to piscine francisellosis thus securing the livelihoods of tilapia farmers worldwide and ensuring the production of this important food source.

scholarly journals Meox Homeodomain Proteins Are Required for Bapx1 Expression in the Sclerotome and Activate Its Transcription by Direct Binding to Its Promoter

2004 ◽  
Vol 24 (7) ◽  
pp. 2757-2766 ◽  
Author(s):  
Isabel Rodrigo ◽  
Paola Bovolenta ◽  
Baljinder S. Mankoo ◽  
Kenji Imai
Keyword(s):  
Chromatin Immunoprecipitation ◽  
Axial Skeleton ◽  
Transient Transfection ◽  
Dependent Manner ◽  
Homeodomain Proteins ◽  
Mobility Shift ◽  
Hierarchical Relationship ◽  
Direct Binding ◽  
Dose Dependent

ABSTRACT The axial skeleton of vertebrates derives from the sclerotomal compartment of the somites. Genetic analysis has demonstrated that the transcription factors Pax1, Pax9, Meox1, Meox2, and Bapx1 are all required for sclerotomal differentiation. Their hierarchical relationship is, however, poorly understood. Because Bapx1 expression in the somites starts slightly later than that of the Meox genes, we asked whether Bapx1 is one of their downstream targets. Our analysis of Meox1; Meox2 mutant mice supports this hypothesis, as Bapx1 expression in the sclerotome is lost in the absence of both Meox proteins. Using transient-transfection assays, we show that Meox1 activates the Bapx1 promoter in a dose-dependent manner and that this activity is enhanced in the presence of Pax1 and/or Pax9. Furthermore, by electrophoretic mobility shift and chromatin immunoprecipitation experiments, we demonstrate that Meox1 can bind the Bapx1 promoter. The palindromic sequence TAATTA, present in the Bapx1 promoter, binds the Meox1 protein in vitro and is necessary for Meox1-induced transactivation of the Bapx1 promoter. Our data demonstrate that the Meox genes are required for Bapx1 expression in the sclerotome and suggest that the mechanism by which the Meox proteins exert this function is through direct activation of the Bapx1 gene.

scholarly journals Larva of greater wax moth Galleria mellonella is a suitable alternative host for the fish pathogen Francisella noatunensis subsp. orientalis

2019 ◽  
Author(s):  
Winarti Achmad Sarmin Djainal ◽  
Khalid Shahin ◽  
Alexandra Adams ◽  
Andrew Desbois
Keyword(s):  
Galleria Mellonella ◽  
Dependent Manner ◽  
Alternative Host ◽  
Prevention Measures ◽  
Suitable Alternative ◽  
Treatment And Prevention ◽  
Greater Wax Moth ◽  
Important Food Source ◽  
Dose Dependent ◽  
Lethal Doses

Abstract Background Francisella noatunensis subsp. orientalis (Fno) is the etiological agent of francisellosis in cultured warm water fish, such as tilapia. Antibiotics are administered to treat the disease but a better understanding of Fno infection biology will inform improved treatment and prevention measures. However, studies with native hosts are costly and considerable benefits would derive from access to a practical alternative host. Here, larvae of Galleria mellonella were assessed for suitability to study Fno virulence. Results Larvae were killed by Fno in a dose-dependent manner but the insects could be rescued from lethal doses of bacteria by antibiotic therapy. Infection progression was assessed by histopathology (haematoxylin and eosin staining, Gram Twort and immunohistochemistry) and enumeration of bacteria recovered from the larval haemolymph on selective agar. Fno was phagocytosed and could survive intracellularly, which is consistent with observations in fish. Virulence of five Fno isolates showed strong agreement between G. mellonella and red Nile tilapia hosts. Conclusions This study shows that an alternative host, G. mellonella, can be applied to understand Fno infections, which will assist efforts to identify solutions to piscine francisellosis thus securing the livelihoods of tilapia farmers worldwide and ensuring the production of this important food source.

A Novel Splicing Factor RBM-9 Regulates Protein 4.1R Exon 16 Splicing.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 805-805 ◽  
Author(s):  
Guang Yang ◽  
Shu-Ching Huang ◽  
Edward J. Benz
Keyword(s):  
Mutational Analysis ◽  
Erythroid Differentiation ◽  
Splicing Factor ◽  
Actin Binding ◽  
Dependent Manner ◽  
Mobility Shift ◽  
Red Cell Membrane ◽  
Protein 4.1R ◽  
Dose Dependent ◽  
Splicing Enhancer

Abstract Protein 4.1R (4.1R), a vital component of the red cell membrane cytoskeleton, stabilizes the spectrin-actin lattice and attaches it to embedded membrane proteins. A regulated splicing event, the inclusion of exon 16 that encodes for peptides critical for spectrin/actin binding, occurs during late erythroid differentiation. We showed earlier that an intricate combination of enhancer and silencer elements direct exon 16 splicing. Regulated expression of splicing factors, SF2/ASF and hnRNP A/B, has also been implicated in mediating exon 16 splicing. In this study, we attempted to characterize the mechanism involved in exon 16 splicing through UGCAUG, an intronic splicing enhancer present in three copies in the intron downstream of exon 16. We first used a wild-type minigene construct consisting of exons 13, 16, 17 and their respective flanking introns that mimics endogenous exon 16 splicing during the induced differentiation of mouse erythroleukemia cells (MELC). Mutational analysis showed a dose-dependent effect of UGCAUG on exon 16 splicing: the presence of all three copies had the most effect. These results were recapitulated with an internal chimeric exon in a test neutral reporter system “DUP4-1”, suggesting that the enhancing effect could be attributed directly to UGCAUG. Furthermore, we identified a novel splicing factor, RBM-9, from MELC that enhanced the internal exon splicing in an UGCAUG-dependent manner in both the exon 16 minigene and DUP4-1 reporter systems. Our characterization of RBM-9 revealed that diverse isoforms of RBM-9 are generated by the utilization of alternative translation initiation sites and tissue-specific alternative splicing; different isoforms from various tissues exhibited differential exon 16 splicing enhancing activities. MELC-RBM-9 enhanced exon 16 splicing the most among all RBM-9 isoforms tested. Inhibition of RBM-9 expression by RBM-9-shRNA reversed its enhancing activity on exon 16 inclusion in MELC. RBM-9-shRNA also reduced exon 16 splicing in a dose-dependent manner in HeLa cells. Furthermore, purified RBM-9 specifically binds to the UGCAUG sequence in a gel-mobility shift assay. Finally, expression of RBM-9 is upregulated and correlates with exon 16 inclusion during MELC differentiation. These results suggest that a novel splicing factor, RBM-9, enhances erythroid differentiation stage-specific exon 16 splicing by interacting with the splicing enhancer UGCAUG.

scholarly journals Efficient Suppression of Abdominal Aortic Aneurysm Expansion in Rats through Systemic Administration of Statin-Loaded Nanomedicine

2020 ◽  
Vol 21 (22) ◽  
pp. 8702
Author(s):  
Natsumi Fukuhara ◽  
Yuto Honda ◽  
Nao Ukita ◽  
Makoto Matsui ◽  
Yutaka Miura ◽  
...  
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Polymeric Micelles ◽  
Polymeric Micelle ◽  
Dependent Manner ◽  
Cancer Treatments ◽  
Abdominal Aortic ◽  
Efficient Suppression ◽  
Life Threatening ◽  
Dose Dependent

Abdominal aortic aneurysm (AAA) is a life-threatening disease. However, no systemically injectable drug has been approved for AAA treatment due to low bioavailability. Polymeric micelles are nanomedicines that have the potential to improve therapeutic efficacy by selectively delivering drugs into disease sites, and research has mainly focused on cancer treatments. Here, we developed a statin-loaded polymeric micelle to treat AAAs in rat models. The micelle showed medicinal efficacy by preventing aortic aneurysm expansion in a dose-dependent manner. Furthermore, the micelle-injected group showed decreased macrophage infiltration and decreased matrix metalloproteinase-9 activity in cases of AAA.

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