TLR9 is important for protection against intestinal damage and for intestinal repair.
Ontology highlight
ABSTRACT:
SUBMITTER: Rose WA
PROVIDER: S-EPMC3418518 | biostudies-other | 2012
REPOSITORIES: biostudies-other
Similar Datasets
Project description:The effects of elevated levels of radiation contribute to the instability of pharmaceutical formulations in space compared to those on earth. Existing technologies are ineffective at maintaining the therapeutic efficacies of drugs in space. Thus, there is an urgent need to develop novel space-hardy formulations for preserving the stability and efficacy of drug formulations. This work aims to develop a novel approach for the protection of space pharmaceutical drug molecules from the radiation-induced damage to help extend or at least preserve their structural integrity and potency. To achieve this, free radical scavenging antioxidant, Trolox was conjugated on the surface of poly-lactic-co-glycolic acid (PLGA) nanoparticles for the protection of a candidate drug, melatonin that is used as a sleep aid medication in International Space Station (ISS). Melatonin-PLGA-PLL-Trolox nanoparticle as named as PolyRad was synthesized employing single oil in water (o/w) emulsion solvent evaporation method. PolyRad is spherical in shape and has an average diameter of ~600?nm with a low polydispersity index of 0.2. PolyRad and free melatonin (control) were irradiated by UV light after being exposed to a strong oxidant, hydrogen peroxide (H2O2). Bare melatonin lost ~80% of the active structure of the drug following irradiation with UV light or treatment with H2O2. In contrast, PolyRad protected >80% of the active structure of melatonin. The ability of PolyRad to protect melatonin structure was also carried out using 0, 1, 5 and 10?Gy?gamma radiation. Gamma irradiation showed >98% active structures of melatonin encapsulated in PolyRads. Drug release and effectiveness of melatonin using PolyRad were evaluated on human umbilical vein endothelial cells (HUVEC) in vitro. Non-irradiated PolyRad demonstrated maximum drug release of ~70% after 72?h, while UV-irradiated and H2O2-treated PolyRad showed a maximum drug release of ~85%. Cytotoxicity of melatonin was carried out using both live/dead and MTT assays. Melatonin, non-radiated PolyRad and irradiated PolyRad inhibited the viability of HUVEC in a dose-dependent manner. Cell viability of melatonin, PolyRad alone without melatonin (PolyRad carrier control), non-radiated PolyRad, and irradiated PolyRad were ~98, 87, 75 and 70%, respectively at a concentration [Formula: see text] 0.01 [Formula: see text] ([Formula: see text]). Taken together, PolyRad nanoparticle provides an attractive formulation platform for preventing damage to pharmaceutical drugs in potential space mission applications.
| S-EPMC7239908 | biostudies-literature
Project description:The purpose of this investigation was the determination of the distribution of genotypes at single nucleotide polymorphisms (SNPs) of the toll-like receptor 4 (TLR4) and the toll-like receptor 9 (TLR9) in fetuses and newborns congenitally infected with Toxoplasma gondii and the identification of genetic changes predisposing to infection development. The study involved 20 fetuses and newborns with congenital toxoplasmosis and 50 uninfected controls. The levels of IgG and IgM antibodies against T. gondii, as well as IgG avidity, were estimated by enzyme-linked fluorescent assay (ELFA) tests. T. gondii DNA loads in amniotic fluids were assayed by the real-time (RT) quantitative polymerase chain reaction (Q PCR) technique for parasitic B1 gene. TLR4 and TLR9 SNPs were identified using a self-designed multiplex nested PCR-restriction fragment length polymorphism (RFLP) assay. Randomly selected genotypes at SNPs were confirmed by sequencing. All the genotypes were tested for Hardy-Weinberg equilibrium and TLR4 genotypes were analyzed for linkage disequilibrium. A correlation was studied between the genotypes or haplotypes and the development of congenital toxoplasmosis using a logistic regression model. Single SNP analysis showed no statistically significant differences in the distribution of distinct genotypes at the analyzed TLR4 and TLR9 SNPs between T. gondii-infected fetuses and newborns and the controls. Taking into account the prevalence of alleles residing within polymorphic sites, similar prevalence rates were observed in both of the studied groups. The multiple SNP analysis indicated GTG variants at the TLR4 and TLR9 SNPs to be significantly less frequent in offspring with congenital toxoplasmosis than in uninfected offspring (p ? 0.0001). TLR4 and TLR9 SNPs seem to be involved in protection against congenital toxoplasmosis.
| S-EPMC4565873 | biostudies-literature
Project description:Extracellular hemoglobin (Hb) has been recognized as a disease trigger in hemolytic conditions such as sickle cell disease, malaria and blood transfusion. In vivo, many of the adverse effects of free Hb can be attenuated by the Hb scavenger acute phase protein haptoglobin (Hp). The primary physiologic disturbances that can be caused be free Hb are found within the cardiovascular system and Hb triggered oxidative toxicity towards the endothelium has been promoted as a potential mechanism. The molecular mechanisms of this toxicity as well as of the protective activities of Hp are not yet clear. Within this study we systematically investigated the structural, biochemical and cell biologic nature of Hb toxicity in an endothelial cell system under peroxidative stress. We identified two principal mechanisms of oxidative Hb toxicity that are mediated by globin degradation products and by modified lipoprotein species, respectively. The two damage pathways trigger diverse and discriminative inflammatory and cytotoxic responses. Hp provides structural stabilization of Hb and shields Hb’s oxidative reactions with lipoproteins providing dramatic protection against both pathways of toxicity. By these mechanisms Hp shifts Hb’s destructive pseudo-peroxidative reaction into a potential anti-oxidative function during peroxidative stress. HPAEC: A two color common reference design was chosen with 4-8 independent biological replicates of each condition. Each experimental sample (Cy5 labeled) was hybridized against a non-treated reference sample (Cy3 labeled). HUVEC: A two color common reference design was chosen with 3-4 independent biological replicates of each condition. Each experimental sample (Cy5 labeled) was hybridized against a non-treated reference sample (Cy3 labeled).
2015-04-30 | E-GEOD-46471 | biostudies-arrayexpress
Project description:During the establishment of an infection, bacterial pathogens encounter oxidative stress resulting in the production of DNA lesions. Majority of these lesions are repaired by base excision repair (BER) pathway. Amongst these, abasic sites are the most frequent lesions in DNA. Class II apurinic/apyrimidinic (AP) endonucleases play a major role in BER of damaged DNA comprising of abasic sites. Mycobacterium tuberculosis, a deadly pathogen, resides in the human macrophages and is continually subjected to oxidative assaults. We have characterized for the first time two AP endonucleases namely Endonuclease IV (End) and Exonuclease III (XthA) that perform distinct functions in M.tuberculosis. We demonstrate that M.tuberculosis End is a typical AP endonuclease while XthA is predominantly a 3'?5' exonuclease. The AP endonuclease activity of End and XthA was stimulated by Mg(2+) and Ca(2+) and displayed a preferential recognition for abasic site paired opposite to a cytosine residue in DNA. Moreover, End exhibited metal ion independent 3'?5' exonuclease activity while in the case of XthA this activity was metal ion dependent. We demonstrate that End is not only a more efficient AP endonuclease than XthA but it also represents the major AP endonuclease activity in M.tuberculosis and plays a crucial role in defense against oxidative stress.
| S-EPMC3731287 | biostudies-literature
Project description:Intestinal inflammation is the central pathological feature of colitis and the inflammatory bowel diseases. These syndromes arise from unidentified environmental factors. We found that recurrent nonlethal gastric infections of Gram-negative Salmonella enterica Typhimurium (ST), a major source of human food poisoning, caused inflammation of murine intestinal tissue, predominantly the colon, which persisted after pathogen clearance and irreversibly escalated in severity with repeated infections. ST progressively disabled a host mechanism of protection by inducing endogenous neuraminidase activity, which accelerated the molecular aging and clearance of intestinal alkaline phosphatase (IAP). Disease was linked to a Toll-like receptor 4 (TLR4)-dependent mechanism of IAP desialylation with accumulation of the IAP substrate and TLR4 ligand, lipopolysaccharide-phosphate. The administration of IAP or the antiviral neuraminidase inhibitor zanamivir was therapeutic by maintaining IAP abundance and function.
| S-EPMC5824721 | biostudies-other
Project description:Extracellular hemoglobin (Hb) has been recognized as a disease trigger in hemolytic conditions such as sickle cell disease, malaria and blood transfusion. In vivo, many of the adverse effects of free Hb can be attenuated by the Hb scavenger acute phase protein haptoglobin (Hp). The primary physiologic disturbances that can be caused be free Hb are found within the cardiovascular system and Hb triggered oxidative toxicity towards the endothelium has been promoted as a potential mechanism. The molecular mechanisms of this toxicity as well as of the protective activities of Hp are not yet clear. Within this study we systematically investigated the structural, biochemical and cell biologic nature of Hb toxicity in an endothelial cell system under peroxidative stress. We identified two principal mechanisms of oxidative Hb toxicity that are mediated by globin degradation products and by modified lipoprotein species, respectively. The two damage pathways trigger diverse and discriminative inflammatory and cytotoxic responses. Hp provides structural stabilization of Hb and shields Hb’s oxidative reactions with lipoproteins providing dramatic protection against both pathways of toxicity. By these mechanisms Hp shifts Hb’s destructive pseudo-peroxidative reaction into a potential anti-oxidative function during peroxidative stress.
2015-04-30 | GSE46471 | GEO
Project description:Caesalpinia crista is a medicinal herb used to cure various ailments in subtropical and tropical regions of Southeast Asia.The objective of this evaluation of C. crista against free radical induced DNA and erythrocyte damage.The profiles of polyphenol and flavonoid were quantified through reversed-phase high-performance liquid chromatography. Free radical induced DNA and membrane damage were performed using H2O2 as oxidative agent.The total polyphenol content of C. crista leaf ethyl acetate extract (CcEA) was 94.5 ± 3.8 mg/gGAE, CcME (C. crista leaf methanol extract) was 52.7 ± 2.8 mg/gGAE, and CcWE (C. crista leaf Water extract) was 31.84 ± 1.8 mg/gGAE. Total flavonoid content of CcEA was 60.46 ± 2.3 mg/gQE, CcME was 46.26 ± 1.8 mg/gQE, and CcWE was 20.47 ± 1.1 mg/gQE. The extracts also exhibited good antioxidant activity as confirmed by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid), hydroxyl scavenging, reducing power, and total antioxidant assays. Among the three extracts, CcEA and CcME showed better protection against red blood cell (RBC) hemolysis and DNA damage as confirmed by electrophoretic study. Further, Scanning electron micrograph data showed that CcEA revealed the free radical induced structural alterations in RBC.These findings suggest that C. crista contains bioactive molecules and can inhibit oxidative stress and can be source of further study to use this in herbal medicine.ROS are generated under normal biological systems. These ROS generated can be scavenged by endogenous and exogenous cellular mechanisms. Environmental stress, radiation, smoke etc. elevates ROS dramatically. This leads to significant damage to cellular biomolecules like DNA and cell structures. Plants as a large reservoir of drugs for protecting DNA and cell structures from oxidative stress. Polyphenols present in the C. crista extracts acts through several mechanisms to quench free radicals. Extracts exhibited potent antioxidant properties and also protected DNA and cell membrane from oxidative damage. Hence this can be used in herbal medicine for treating oxidative stress mediated diseases. Abbreviations used: ABTS: 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid); CcEA: C. crista leaf ethyl acetate extract; CcME: C. crista leaf methanol extract; CcWE: C. crista leaf Water extract; DPPH: 2,2-diphenyl-1-picrylhydrazyl; GAE: Gallic acid Equivalent; H2O2: Hydrogen Peroxide; QE: Quercetin Equivalent; RNS: Reactive Nitrogen Spevcies; ROS: Reactive Oxygen Species; SEM: Scanning Electron Microscope.
| S-EPMC5538162 | biostudies-other
Project description:Inflammatory bowel disease is a chronic gastrointestinal inflammatory disorder associated with changes in neuropeptide expression and function, including vasoactive intestinal peptide (VIP). VIP regulates intestinal vasomotor and secretomotor function and motility; however, VIP's role in development and maintenance of colonic epithelial barrier homeostasis is unclear. Using VIP deficient (VIPKO) mice, we investigated VIP's role in epithelial barrier homeostasis, and susceptibility to colitis. Colonic crypt morphology and epithelial barrier homeostasis were assessed in wildtype (WT) and VIPKO mice, at baseline. Colitic responses were evaluated following dinitrobenzene sulfonic acid (DNBS) or dextran-sodium sulfate (DSS) exposure. Mice were also treated with exogenous VIP. At baseline, VIPKO mice exhibited distorted colonic crypts, defects in epithelial cell proliferation and migration, increased apoptosis, and altered permeability. VIPKO mice also displayed reduced goblet cell numbers, and reduced expression of secreted goblet cell factors mucin 2 and trefoil factor 3. These changes were associated with reduced expression of caudal type homeobox 2 (Cdx2), a master regulator of intestinal function and homeostasis. DNBS and DSS-induced colitis were more severe in VIPKO than WT mice. VIP treatment rescued the phenotype, protecting VIPKO mice against DSS colitis, with results comparable to WT mice. In conclusion, VIP plays a crucial role in the development and maintenance of colonic epithelial barrier integrity under physiological conditions and promotes epithelial repair and homeostasis during colitis.
| S-EPMC4416880 | biostudies-literature
Project description:Severe sepsis remains a poorly understood systemic inflammatory condition with high mortality rates and limited therapeutic options in addition to organ support measures. Here we show that the clinically approved group of anthracyclines acts therapeutically at a low dose regimen to confer robust protection against severe sepsis in mice. This salutary effect is strictly dependent on the activation of DNA damage response and autophagy pathways in the lung, as demonstrated by deletion of the ataxia telangiectasia mutated (Atm) or the autophagy-related protein 7 (Atg7) specifically in this organ. The protective effect of anthracyclines occurs irrespectively of pathogen burden, conferring disease tolerance to severe sepsis. These findings demonstrate that DNA damage responses, including the ATM and Fanconi Anemia pathways, are important modulators of immune responses and might be exploited to confer protection to inflammation-driven conditions, including severe sepsis.
| S-EPMC3968948 | biostudies-literature
Project description:Extracellular hemoglobin (Hb) has been recognized as a disease trigger in hemolytic conditions such as sickle cell disease, malaria, and blood transfusion. In vivo, many of the adverse effects of free Hb can be attenuated by the Hb scavenger acute-phase protein haptoglobin (Hp). The primary physiologic disturbances that can be caused by free Hb are found within the cardiovascular system and Hb-triggered oxidative toxicity toward the endothelium has been promoted as a potential mechanism. The molecular mechanisms of this toxicity as well as of the protective activities of Hp are not yet clear. Within this study, we systematically investigated the structural, biochemical, and cell biologic nature of Hb toxicity in an endothelial cell system under peroxidative stress. We identified two principal mechanisms of oxidative Hb toxicity that are mediated by globin degradation products and by modified lipoprotein species, respectively. The two damage pathways trigger diverse and discriminative inflammatory and cytotoxic responses. Hp provides structural stabilization of Hb and shields Hb's oxidative reactions with lipoproteins, providing dramatic protection against both pathways of toxicity. By these mechanisms, Hp shifts Hb's destructive pseudo-peroxidative reaction to a potential anti-oxidative function during peroxidative stress.
| S-EPMC3792434 | biostudies-literature