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1.
PLoS One ; 19(3): e0297292, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38483964

RESUMO

Inflammatory bowel disease (IBD) is characterized by chronic intestinal inflammation resulting from an inappropriate inflammatory response to intestinal microbes in a genetically susceptible host. Reactive oxygen species (ROS) generated by NADPH oxidases (NOX) provide antimicrobial defense, redox signaling and gut barrier maintenance. NADPH oxidase mutations have been identified in IBD patients, and mucus layer disruption, a critical aspect in IBD pathogenesis, was connected to NOX inactivation. To gain insight into ROS-dependent modification of epithelial glycosylation the colonic and ileal mucin O-glycome of mice with genetic NOX inactivation (Cyba mutant) was analyzed. O-glycans were released from purified murine mucins and analyzed by hydrophilic interaction ultra-performance liquid chromatography in combination with exoglycosidase digestion and mass spectrometry. We identified five novel glycans in ileum and found minor changes in O-glycans in the colon and ileum of Cyba mutant mice. Changes included an increase in glycans with terminal HexNAc and in core 2 glycans with Fuc-Gal- on C3 branch, and a decrease in core 3 glycans in the colon, while the ileum showed increased sialylation and a decrease in sulfated glycans. Our data suggest that NADPH oxidase activity alters the intestinal mucin O-glycans that may contribute to intestinal dysbiosis and chronic inflammation.


Assuntos
Doenças Inflamatórias Intestinais , Mucinas , Humanos , Camundongos , Animais , Espécies Reativas de Oxigênio , Mucinas/química , Inflamação , Polissacarídeos/química , NADPH Oxidases/genética , Mucosa Intestinal/química
2.
J Biomol Struct Dyn ; 41(6): 2341-2354, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-35098888

RESUMO

Cross-reactive and broadly neutralizing antibodies against surface proteins of diverse strains of rapidly evolving viral pathogens like SARS-CoV-2 can prevent infection and therefore are crucial for the development of effective universal vaccines. While antibodies typically incorporate mutations in their complementarity determining regions during affinity maturation, mutations in the framework regions have been reported as players in determining properties of broadly neutralizing antibodies against HIV and the Influenza virus. We propose an increase in the cross-reactive potential of CR3022 against the emerging SARS- CoV-2 variants of concern through enhanced conformational flexibility. In this study, we use molecular dynamics simulations, in silico mutagenesis, structural modeling, and docking to explore the role of light chain FWR mutations in CR3022, a SARS-CoV anti-spike (S)-protein antibody cross-reactive to the S-protein receptor binding domain of SARS-CoV-2. Our study shows that single substitutions in the light chain framework region of CR3022 with conserved epitopes across SARS-CoV strains allow targeting of diverse antibody epitope footprints that align with the epitopes of recently-categorized neutralizing antibody classes while enabling binding to more than one strain of SARS-CoV-2. Our study has implications for rapid and evolution-based engineering of broadly neutralizing antibodies and reaffirms the role of framework mutations in effective change of antibody orientation and conformation via improved flexibility.Communicated by Ramaswamy H. Sarma.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , SARS-CoV-2/metabolismo , Anticorpos Antivirais/genética , Anticorpos Antivirais/química , Anticorpos Amplamente Neutralizantes , Anticorpos Neutralizantes/química , Epitopos , Mutação
3.
Nephrology (Carlton) ; 28(1): 60-71, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36217796

RESUMO

AIM: Podocytes, a vital component of the glomerular filtration barrier, are vulnerable to various noxious stimuli, including Hypoxic. HIF1α that transduces hypoxic adaptations induces Transglutaminase 2 (TG2), which catalyses cross-linking of extracellular matrix proteins. In this study, we investigated the mechanism of regulation of TG2 by HIF1α. METHODS: HIF1α was induced in podocytes by treating with FG4592 (Roxadustat) or hypoxia (1% oxygen) and in mice by treating with FG4592. Gene expression and protein analysis of ZEB2, TRPC6 and TG2 were performed in both experimental models. Histological and kidney function analyses were performed in mice. RESULTS: Data mining revealed co-expression of HIF1α, ZEB2, TRPC6 and TG2 in the chronic kidney diseases (CKD)-validated dataset. We observed elevated expression of ZEB2, TRPC6 and TG2 in FG4592-treated podocytes. Ectopic expression of ZEB2 resulted in high TRPC6 expression, elevated intracellular calcium levels and increased TG2 activity. Blocking the TRPC6 channel or inhibiting its expression partially attenuated FG4592-induced TG2 activity, whereas suppression of ZEB2 expression significantly abolished TG2 activity. Furthermore, we noticed the induction of the ZEB2/TRPC6/TG2 axis in podocytes in mice administered with FG-4592. Metformin ameliorated the HIF1α-induced podocyte injury and proteinuria in mice administered with FG-4592. CONCLUSION: This study demonstrates that HIF1α stimulates both TG2 expression and activity via ZEB2/TRPC6 axis, whereas abrogation of HIF1α by metformin prevented hypoxia-induced glomerular injury. Metformin could be explored to treat proteinuric diseases such as CKD, sleep apnea and renal Ischemia-reperfusion-injury, where hypoxia is considered a risk factor.


Assuntos
Metformina , Podócitos , Insuficiência Renal Crônica , Camundongos , Animais , Podócitos/metabolismo , Canal de Cátion TRPC6/genética , Canal de Cátion TRPC6/metabolismo , Metformina/farmacologia , Proteína 2 Glutamina gama-Glutamiltransferase , Canais de Cátion TRPC/genética , Canais de Cátion TRPC/metabolismo , Hipóxia/complicações , Hipóxia/metabolismo , Hipóxia/patologia , Insuficiência Renal Crônica/genética , Insuficiência Renal Crônica/prevenção & controle , Insuficiência Renal Crônica/metabolismo
4.
J Basic Microbiol ; 63(3-4): 359-376, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36453555

RESUMO

Despite the ubiquity of the genus Citrobacter in clinical, industrial, and environmental scenarios, a large number of Citrobacter strains have not been explored at the genome-scale level. In this study, accurate taxonomic assignment of strain AAK_AS5 isolated from activated sludge was achieved by in-silico genomic comparison using Overall Genome-based Relatedness Indices (ANI(OAT): 97.55%, ANIb:97.28%, and ANIm: 97.83%) that indicated its closest identity to the related strain Citrobacter portucalensis A60T . Results were consistent with a digital DNA-DNA hybridization value of 80% with C. portucalensis A60T which was greater than the species boundary value >70% for delineating closely related bacterial species. Gene mining through Kyoto Encyclopedia of Genes and Genomes (KEGG), and annotation using rapid annotation subsystem technology (RAST) revealed the notable gene contents for nitrogen metabolism and other pathways associated with nitrate/nitrite ammonification (28 genes), ammonia assimilation (22 genes), and denitrification pathways (14 genes). Furthermore, the strain AAK_AS5 also exhibited a high soluble chemical oxygen demand (sCOD), NH4 + -N, and NO3 - -N removal efficiency of 91.4%, 90%, and 93.6%, respectively thus validating its genetic capability for utilizing both (NH4 )2 SO4 and KNO3 as the nitrogen source. The study provided deeper insights into the phylogenomics and the genetic potential of Citrobacter, sp. strain AAK AS5 associated with nitrogen metabolism thus signifying the potential application of the isolate for treating nitrogen-rich wastewaters.


Assuntos
Desnitrificação , Nitrogênio , Filogenia , Citrobacter/genética , DNA
5.
Indian J Dent Res ; 33(4): 350-355, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-37005995

RESUMO

Objective: To evaluate and compare the effect of variation in storage temperatures and duration on a tensile load at failure of elastomeric modules. Methods: In total, 140 modules were used in the study, 20 of which were tested on day 0 as received from a company using a Universal testing machine for baseline estimation of tensile load at failure. The rest 120 modules were divided into 6 groups. Groups I, II, and III modules were stored at low (T1 = 1-5°C), moderate (T2 = 20-25°C) and high (T3 = 35-40°C) temperatures, respectively, for 6 months. Groups IV, V and VI modules were stored at temperatures T1, T2 and T3 for 1 year, respectively, and were tested for tensile load at failure. Results: The tensile load at failure for the control group was 21.588 ± 1.082 N and for 6-month interval at temperatures T1, T2 and T3 was 18.818 N ± 1.121 N, 17.841 N ± 1.334 N and 17.149 N ± 1.074 N, respectively, and for 1 year, it was 17.205 N ± 1.043 N, 16.836 N ± 0.487 N and 14.788 N ± 0.781 N, respectively. The tensile load at failure decreased significantly from 6 months to 1 year among each temperature group. Conclusions: Maximum force degradation was seen in modules at high temperature followed by medium temperature and low temperature at both 6 months and 1 year intervals, and tensile load at failure decreased significantly from 6 months to 1 year storage duration. These results conclude that the temperature and duration at which the samples were exposed during storage produce a significant change in the forces exerted by the modules.


Assuntos
Braquetes Ortodônticos , Temperatura , Teste de Materiais , Elasticidade , Temperatura Alta , Resistência à Tração
6.
Front Med (Lausanne) ; 8: 685447, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34277660

RESUMO

The prevalence of diabetes reaches epidemic proportions. Diabetes is the leading cause of end-stage kidney disease (ESKD) since 30-40% of diabetic patients develop diabetic nephropathy. Albuminuria and glomerular filtration rate used to assess kidney function are considered surrogate outcomes of chronic kidney disease. The search for a biomarker that predicts progression to diabetic kidney disease is intense. We analyzed the association of serum advanced glycation end-products (AGEs) index (AGI) with impaired kidney function in poorly controlled type II diabetic patients. We observed an association between AGI and impaired kidney function in microalbuminuria patients with hyperglycemia. A significant association between AGEs, particularly carboxymethyl lysine (CML), and impaired kidney function were observed. Administration of AGEs to mice showed heavy proteinuria and glomerular abnormalities. Reduced podocyte number in mice administered with AGEs could be attributed to the epithelial-mesenchymal transition of podocytes. Our study suggests CML could be independently related to the podocyte injury and the risk of DN progression to ESKD in patients with microalbuminuria. AGEs in general or CML could be considered a prognostic marker to assess diabetic kidney disease.

7.
J Physiol Biochem ; 77(2): 193-203, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33835424

RESUMO

Hypoxia-inducible factor1 (HIF1) plays a pivotal role in ensuring cells adapt to low-oxygen conditions. Depletion of oxygen, a co-substrate during hydroxylation of prolyl (P402 and P564) residues of HIF1⍺, evades HIF1⍺ ubiquitination and enables its dimerization with HIF1ß to mediate global transcriptional response to hypoxia. Though HIF1 is largely considered eliciting a protective role during physiological or pathological hypoxia or ischemia, elevated HIF1 during chronic hypoxia contributes to glomerular diseases' pathology and proteinuria. The glomerulus is responsible for renal permselectivity and excretion of ultra-filtrated urine. Podocytes are the glomerulus' major cell types and are instrumental for glomerular filtration, permselectivity, and glomerular basement membrane maintenance. Podocyte injury is expected to impair the efficiency of glomerular filtration and manifestation of glomerulosclerosis and proteinuria. Accumulated evidence suggests that podocytes are susceptible to various insults during chronic hypoxia, including podocyte EMT, slit-diaphragm dysfunction, foot process effacement, and cytoskeletal derangement due to accumulation of HIF1. This review discusses how hypoxia/HIF1 signaling regulates various features and function of podocytes during exposure to chronic hypoxia or inducing HIF1 by various chemical modulators.


Assuntos
Translocador Nuclear Receptor Aril Hidrocarboneto/genética , Glomerulonefrite/genética , Glomerulosclerose Segmentar e Focal/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Hipóxia/genética , Podócitos/metabolismo , Proteinúria/genética , Animais , Translocador Nuclear Receptor Aril Hidrocarboneto/metabolismo , Doença Crônica , Citoesqueleto/metabolismo , Citoesqueleto/patologia , Transição Epitelial-Mesenquimal , Regulação da Expressão Gênica , Barreira de Filtração Glomerular/metabolismo , Barreira de Filtração Glomerular/patologia , Glomerulonefrite/etiologia , Glomerulonefrite/metabolismo , Glomerulonefrite/patologia , Glomerulosclerose Segmentar e Focal/etiologia , Glomerulosclerose Segmentar e Focal/metabolismo , Glomerulosclerose Segmentar e Focal/patologia , Humanos , Hipóxia/complicações , Hipóxia/metabolismo , Hipóxia/patologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Podócitos/patologia , Proteinúria/etiologia , Proteinúria/metabolismo , Proteinúria/patologia , Transdução de Sinais , Canal de Cátion TRPC6/genética , Canal de Cátion TRPC6/metabolismo , Homeobox 2 de Ligação a E-box com Dedos de Zinco/genética , Homeobox 2 de Ligação a E-box com Dedos de Zinco/metabolismo
8.
Cytokine ; 145: 155208, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-32736961

RESUMO

Dendritic cells (DCs), as antigen-presenting cells, can reportedly be infected withLeishmaniaparasites and hence provide a better option to trigger T-cell primary immune responses and immunological memory. We consistently primed DCs during culture with purified recombinant cytosolic tryparedoxin (rcTXN) and then evaluated the vaccine prospect of presentation of rcTXN against VL in BALB/c mice. We reported earlier the immunogenic properties of cTXN antigen derived fromL. donovani when anti-cTXN antibody was detected in the sera of kala-azar patients. It was observed that cTXN antigen, when used as an immunogen with murine DCs acting as a vehicle, was able to induce complete protection against VL in an infected group of immunized mice. This vaccination triggered splenic macrophages to produce more IL-12 and GM-CSF, and restricted IL-10 release to a minimum in an immunized group of infected animals. Concomitant changes in T-cell responses against cTXN antigen were also noticed, which increased the release of protective cytokine-like IFN-γ under the influence of NF-κß in the indicated vaccinated group of animals. All cTXN-DCs-vaccinated BALB/c mice survived during the experimental period of 120 days. The results obtained in our study suggest that DCs primed with cTXN can be used as a vaccine prospect for the control of visceral leishmaniasis.


Assuntos
Células Dendríticas/imunologia , Leishmania donovani/imunologia , Vacinas contra Leishmaniose/imunologia , Leishmaniose Visceral/imunologia , Animais , Citocinas/imunologia , Células Dendríticas/parasitologia , Imunidade Celular/imunologia , Interleucina-10/imunologia , Interleucina-12/imunologia , Leishmaniose Visceral/parasitologia , Macrófagos/imunologia , Macrófagos/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Proteínas de Protozoários/imunologia , Linfócitos T/imunologia , Linfócitos T/parasitologia
9.
Plant Sci ; 298: 110592, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32771150

RESUMO

The root-knot nematode (RKN) Meloidogyne incognita is considered one of the most damaging pests among phytonematodes. The majority of nematode oesophageal gland effector genes are indispensable in facilitating M. incognita parasitization of host plants. We report the effect of host-delivered RNAi (HD-RNAi) silencing of four selected M. incognita effector genes, namely, Mi-msp3, Mi-msp5, Mi-msp18 and Mi-msp24, in Arabidopsis thaliana. Mi-msp5, Mi-msp18 and Mi-msp24, which are dorsal gland genes, were found to be maximally expressed in the adult female stage, whereas Mi-msp3, which is a sub-ventral gland gene, was maximally expressed in an earlier stage. In transgenic plants expressing dsRNA, the reduction in the number of galls on roots was 89 %, 78 %, 86 % and 89 % for the Mi-msp3, Mi-msp5, Mi-msp18 and Mi-msp24 RNAi events, respectively. Moreover, gene transcript abundance was significantly reduced in RKN females feeding on dsRNA-expressing lines by up to 60 %, 84 %, 31 % and 61 % for Mi-msp3, Mi-msp5, Mi-msp18 and Mi-msp24, respectively. Furthermore, the M. incognita reproduction factor was reduced up to 71-, 344-, 107- and 114-fold in Arabidopsis plants expressing Mi-msp3, Mi-msp5, Mi-msp18 and Mi-msp24 dsRNA constructs, respectively. This study provides a set of potential target genes to curb nematode infestation in economically important crops via the HD-RNAi approach.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Doenças das Plantas/genética , Tylenchoidea/fisiologia , Sequência de Aminoácidos , Animais , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Resistência à Doença/genética , Inativação Gênica , Filogenia , Doenças das Plantas/parasitologia , Interferência de RNA , Alinhamento de Sequência
10.
ACS Omega ; 5(23): 13503-13520, 2020 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-32566815

RESUMO

In the present study, comparative analyses of corrosion inhibition property of few thiadiazole-derived bis-Schiff bases for mild steel in 1 M HCl were done. Various electrochemical experiments (electrochemical impedance spectroscopy and potentiodynamic polarization), as well as weight loss experiments, were employed to study the anticorrosion activity of bis-Schiff bases as inhibitors. The highest inhibition efficiency was obtained at an optimum concentration of 125 ppm for all inhibitors. Potentiodynamic polarization studies explain the mixed type but predominantly the cathodic nature of all inhibitors. The Langmuir adsorption isotherm was used to describe the mechanism of adsorption. The change in the value of activation energy on the addition of inhibitors reflects the mixed mode of interaction between the inhibitor and metallic surface. Scanning electron microscopy with energy-dispersive spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy analyses confirmed the adsorption of bis-Schiff bases on the metal surface and thereby shielding from corrosion. Besides, the relevance between inhibition efficiency and the molecular structure of an inhibitor was theoretically examined via quantum chemical calculations and molecular dynamics simulations. All the results show consistent agreement with each other.

11.
Sci Rep ; 9(1): 17404, 2019 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-31757987

RESUMO

Root-knot nematodes (RKNs) are devastating parasites that infect thousands of plants. As RKN infection is facilitated by oesophageal gland effector genes, one such effector gene, Mi-msp2, was selected for a detailed characterization. Based on domain analysis, the Mi-MSP2 protein contains an ShKT domain, which is likely involved in blocking K+ channels and may help in evading the plant defence response. Expression of the Mi-msp2 gene was higher in juveniles (parasitic stage of RKNs) than in eggs and adults. Stable homozygous transgenic Arabidopsis lines expressing Mi-msp2 dsRNA were generated, and the numbers of galls, females and egg masses were reduced by 52-54%, 60-66% and 84-95%, respectively, in two independent RNAi lines compared with control plants. Furthermore, expression analysis revealed a significant reduction in Mi-msp2 mRNA abundance (up to 88%) in female nematodes feeding on transgenic plants expressing dsRNA, and northern blot analysis confirmed expression of the Mi-msp2 siRNA in the transgenic plants. Interestingly, a significant reduction in the reproduction factor was observed (nearly 40-fold). These data suggest that the Mi-msp2 gene can be used as a potential target for RKN management in crops of economic importance.


Assuntos
Arabidopsis/genética , Arabidopsis/parasitologia , Resistência à Doença/genética , Inativação Gênica , Proteínas de Protozoários/genética , Interferência de RNA , RNA Interferente Pequeno/genética , Sequência de Aminoácidos , Animais , Feminino , Herbivoria , Plantas Geneticamente Modificadas , Proteínas de Protozoários/química
12.
Mucosal Immunol ; 12(6): 1316-1326, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31554901

RESUMO

Reactive oxygen species (ROS) generated by NADPH oxidases (NOX/DUOX) provide antimicrobial defense, redox signaling, and gut barrier maintenance. Inactivating NOX variants are associated with comorbid intestinal inflammation in chronic granulomatous disease (CGD; NOX2) and pediatric inflammatory bowel disease (IBD; NOX1); however Nox-deficient mice do not reflect human disease susceptibility. Here we assessed if a hypomorphic patient-relevant CGD mutation will increase the risk for intestinal inflammation in mice. Cyba (p22phox) mutant mice generated low intestinal ROS, while maintaining Nox4 function. The Cyba variant caused profound mucus layer disruption with bacterial penetration into crypts, dysbiosis, and a compromised innate immune response to invading microbes, leading to mortality. Approaches used in treatment-resistant CGD or pediatric IBD such as bone marrow transplantation or oral antibiotic treatment ameliorated or prevented disease in mice. The Cyba mutant mouse phenotype implicates loss of both mucus barrier and efficient innate immune defense in the pathogenesis of intestinal inflammation due to ROS deficiency, supporting a combined-hit model where a single disease variant compromises different cellular functions in interdependent compartments.


Assuntos
Colite/enzimologia , Colo/enzimologia , Grupo dos Citocromos b/metabolismo , Mucosa Intestinal/enzimologia , Muco/enzimologia , NADPH Oxidases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Antibacterianos/farmacologia , Colite/imunologia , Colite/microbiologia , Colite/prevenção & controle , Colo/efeitos dos fármacos , Colo/imunologia , Colo/microbiologia , Grupo dos Citocromos b/deficiência , Grupo dos Citocromos b/genética , Modelos Animais de Doenças , Disbiose , Feminino , Microbioma Gastrointestinal , Imunidade Inata , Imunidade nas Mucosas , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/imunologia , Mucosa Intestinal/microbiologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Mutantes , Muco/imunologia , Muco/microbiologia , Mutação de Sentido Incorreto , NADPH Oxidases/deficiência , NADPH Oxidases/genética , Transdução de Sinais
13.
Org Biomol Chem ; 17(32): 7497-7506, 2019 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-31365007

RESUMO

The nature and coordination sites of the Schiff base 3,3'-(1E,1'E)-(1,3-phenylenebis(azan-1-yl-1-ylidene))bis(methan-1-yl-1-ylidene)dinaphthalen-2-ol (APHN) were tuned by its selective reduction to design a highly efficient fluorescent probe, 3,3'-(pyridine-2,6-diylbis(azanediyl))bis(methylene)dinaphthalen-2-ol (RAPHN). The structures of APHN, RAPHN, and the RAPHN-Fe3+ complex were satisfactorily modeled from the results of density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations. RAPHN worked in pure aqueous medium as a turn on-off-on probe of Fe3+ and F-. The fluorescence nature of the probe in the presence and absence of Fe3+/F- was regulated by a set of mechanisms including -CH[double bond, length as m-dash]N isomerization and LMCT. A 2 : 1 (M : L) binding stoichiometry was established from a fluorescence Job's plot and further substantiated from HR-MS studies. The limits of detection of RAPHN for Fe3+ and RAPHN-Fe3+ for F- were found to be 2.49 × 10-7 M and 1.09 × 10-7 M, respectively. The RAPHN probe caused no cytotoxicity in gut tissue of Drosophila even at high concentrations. The probe displayed excellent bioimaging applications for detection of Fe3+ and F- in gut tissue of Drosophila. A combinatorial logic gate was constructed for the proper understanding of the working principle of RAPHN.


Assuntos
Complexos de Coordenação/química , Corantes Fluorescentes/química , Íons/análise , Bases de Schiff/química , Animais , Técnicas Biossensoriais , Linhagem Celular , Teoria da Densidade Funcional , Drosophila , Intestinos/citologia , Cinética , Ligantes , Modelos Moleculares , Naftalenos/química , Espectrometria de Fluorescência
14.
J Cell Biochem ; 119(9): 7406-7418, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29775225

RESUMO

Post kala-azar dermal leishmaniasis (PKDL) is often considered to be the anthroponotic reservoir of visceral leishmaniasis (VL) in India. A better understanding of the host immune-response in dermal lesions of PKDL patients is therefore of utmost significance to minimize such patients and to restrict VL transmission. Although the innate immune response is known to play an important role in parasite clearance from dermal lesions, the actual contribution of innate cells to the pathogenicity of PKDL is poorly understood. The present study explored the immune-pathogenesis of PKDL patients to understand the expression of CD62L, CD11b, CXCL8/IL-8, and MIP1-α and their contribution in signaling during innate cell trafficking. Twenty-five individuals were enrolled, who comprised eight active and untreated macular cases, seven active and untreated cases with papulo-nodular PKDL manifestations, five successfully treated post PKDL cases and five healthy individuals from a non-endemic region of Bihar, India. The immunological investigation was performed on biopsy specimens prepared with a disaggregation technique and blood samples. We observed that the PMNs in nodular patients displayed decreased L-selectin (CD62L) levels and increased integrin (CD11b) expression compared with those in macular patients. Further analysis showed that lower PMN extravasation in macular patients occurred because of inadequate CXCL8/ IL-8 release. In summary, Leishmania donovani (L. donovani) infection in macular PKDL patients decreased leucocyte rolling (L-selectin shedding) and induced up-regulation of the cellular signaling factors involved in pathogenesis (ERK1/2) as well as down regulated the signaling elements (p38 MAPK) involved in the Th1 response, especially in PMNs.


Assuntos
Citocinas/genética , Regulação da Expressão Gênica , Imunidade Inata , Leishmaniose Visceral/genética , Adolescente , Adulto , Quimiocinas/genética , Quimiocinas/imunologia , Criança , Citocinas/imunologia , Feminino , Humanos , Leishmaniose Visceral/imunologia , Leishmaniose Visceral/metabolismo , Masculino , Pessoa de Meia-Idade , Neutrófilos/imunologia , Neutrófilos/metabolismo , Adulto Jovem
15.
Redox Biol ; 16: 11-20, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29471162

RESUMO

Inflammatory bowel disease (IBD) is a multifactorial chronic inflammatory disease of the gastrointestinal tract, characterized by cycles of acute flares, recovery and remission phases. Treatments for accelerating tissue restitution and prolonging remission are scarce, but altering the microbiota composition to promote intestinal homeostasis is considered a safe, economic and promising approach. Although probiotic bacteria have not yet fulfilled fully their promise in clinical trials, understanding the mechanism of how they exert beneficial effects will permit devising improved therapeutic strategies. Here we probe if one of the defining features of lactobacilli, the ability to generate nanomolar H2O2, contributes to their beneficial role in colitis. H2O2 generation by wild type L. johnsonii was modified by either deleting or overexpressing the enzymatic H2O2 source(s) followed by orally administering the bacteria before and during DSS colitis. Boosting luminal H2O2 concentrations within a physiological range accelerated recovery from colitis, while significantly exceeding this H2O2 level triggered bacteraemia. This study supports a role for increasing H2O2 within the physiological range at the epithelial barrier, independently of the enzymatic source and/or delivery mechanism, for inducing recovery and remission in IBD.


Assuntos
Colite/metabolismo , Peróxido de Hidrogênio/metabolismo , Doenças Inflamatórias Intestinais/metabolismo , Lactobacillus/metabolismo , Animais , Colite/induzido quimicamente , Colite/microbiologia , Colite/patologia , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Regulação da Expressão Gênica , Humanos , Peróxido de Hidrogênio/isolamento & purificação , Doenças Inflamatórias Intestinais/induzido quimicamente , Doenças Inflamatórias Intestinais/microbiologia , Doenças Inflamatórias Intestinais/patologia , Camundongos , Camundongos Endogâmicos C57BL , Microbiota
16.
Drug Dev Ind Pharm ; 44(7): 1212-1221, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29429364

RESUMO

OBJECTIVE: Aim of the present study was to prepare curcumin (CUR) loaded biodegradable crosslinked gelatin (GE) film to alleviate the existing shortcomings in the treatment of periodontitis. SIGNIFICANCE: Gelatin film was optimized to provide anticipated mucoadhesive strength, mechanical properties, folding endurance, and prolonged drug release over treatment duration, for successful application in the periodontitis. METHODS: The film was developed by using solvent casting technique and "Design of Experiments" approach was employed for evaluating the influence of independent variables on dependent response variables. Solid-state characterization of the film was performed by FTIR, XRD, and SEM. Further, prepared formulations were evaluated for drug content uniformity, surface pH, folding endurance, swelling index, mechanical strength, mucoadhesive strength, in vitro biodegradation, and in vitro drug release behavior. RESULTS: Solid state characterization of the formulation showed that CUR is physico-chemically compatible with other excipients and CUR was entrapped in an amorphous form inside the smooth and uniform film. The optimized film showed degree of crosslinking 51.04 ± 2.4, swelling index 138.10 ± 1.25, and folding endurance 270 ± 3 with surface pH around 7.0. Crosslinker concentrations positively affected swelling index and biodegradation of film due to altered matrix density of the polymer. Results of in vitro drug release demonstrated the capability of the developed film for efficiently delivering CUR in a sustained manner up to 7 days. CONCLUSIONS: The developed optimized film could be considered as a promising delivery strategy to administer medicament locally into the periodontal pockets for the safe and efficient management of periodontitis.


Assuntos
Curcumina/química , Gelatina/química , Plásticos Biodegradáveis/química , Química Farmacêutica/métodos , Curcumina/farmacologia , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos/efeitos dos fármacos , Excipientes/química , Humanos , Periodontite/tratamento farmacológico , Polímeros/química
17.
Front Microbiol ; 8: 1517, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28848526

RESUMO

Bacterial biofilm has been reported to be associated with more than 80% of bacterial infections. Curcumin, a hydrophobic polyphenol compound, has anti-quorum sensing activity apart from having antimicrobial action. However, its use is limited by its poor aqueous solubility and rapid degradation. In this study, we attempted to prepare quantum dots of the drug curcumin in order to achieve enhanced solubility and stability and investigated for its antimicrobial and antibiofilm activity. We utilized a newer two-step bottom up wet milling approach to prepare Curcumin Quantum Dots (CurQDs) using acetone as a primary solvent. Minimum inhibitory concentration against select Gram-positive and Gram-negative bacteria was performed. The antibiofilm assay was performed at first using 96-well tissue culture plate and subsequently validated by Confocal Laser Scanning Microscopy. Further, biofilm matrix protein was isolated using formaldehyde sludge and TCA/Acetone precipitation method. Protein extracted was incubated with varying concentration of CurQDs for 4 h and was subjected to SDS-PAGE. Molecular docking study was performed to observe interaction between curcumin and phenol soluble modulins as well as curli proteins. The biophysical evidences obtained from TEM, SEM, UV-VIS, fluorescence, Raman spectroscopy, and zeta potential analysis confirmed the formation of curcumin quantum dots with increased stability and solubility. The MICs of curcumin quantum dots, as observed against both select gram positive and negative bacterial isolates, was observed to be significantly lower than native curcumin particles. On TCP assay, Curcumin observed to be having antibiofilm as well as biofilm degrading activity. Results of SDS-PAGE and molecular docking have shown interaction between biofilm matrix proteins and curcumin. The results indicate that aqueous solubility and stability of Curcumin can be achieved by preparing its quantum dots. The study also demonstrates that by sizing down the particle size has not only enhanced its antimicrobial properties but it has also shown its antibiofilm activities. Further, study is needed to elucidate the exact nature of interaction between curcumin and biofilm matrix proteins.

18.
J Food Sci Technol ; 54(6): 1638-1645, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28559623

RESUMO

The octenyl succinyl anhydride (OSA) esterified pearl millet (Pennisetum typhoides) starch was evaluated as fat replacer in soft serve ice cream in comparison to other fat replacers viz. inulin, whey protein concentrate-70 and commercial starch. During temperature sweep test, the yield stress and flow behaviour index of un-pasteurized ice cream mixes increased as the temperature increased from 40 to 80 °C, while the consistency index decreased. Consistency index of aged ice cream mixes containing 2% fat replacer was higher as compared to mixes with 1% level. The aged ice cream mixes exhibited non-Newtonian behaviour as flow behaviour index values were less than one. Apparent viscosity (at 50 s-1 shear rate) of control as well as ice cream mix containing 1% OSA-esterified pearl millet starch samples was 417 and 415 mPas, respectively and did not differ significantly. The overrun of the ice cream (with 5 and 7.5% fat) containing 1 and 2% of above fat replacers ranged between 29.7 and 34.3% and was significantly lower than control (40.3%). The percent melted ice cream was also low for the ice creams containing 2% of above fat replacers at 5% fat content as compared to control. However, sensory acceptability and rheological characteristics of reduced fat ice creams containing 1.0 and 2.0% OSA-esterified pearl millet starch were at par with other fat replacers under the study. Thus, OSA-esterified pearl millet starch has potential to be used as fat replacer in reduced fat ice cream.

20.
Microbes Infect ; 19(6): 358-369, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28373107

RESUMO

Leishmaniases are vector-borne diseases for which no vaccine exists. These diseases are caused by the Leishmania species complex. Activation of the CD8+ T cell is crucial for protection against intracellular pathogens, and peptide antigens are attractive strategies for the precise activation of CD8+ T in vaccine development against intracellular infections. The traditional approach to mine the epitopes is an arduous task. However, with the advent of immunoinformatics, in silico epitope prediction tools are available to expedite epitope identification. In this study, we employ different immunoinformatics tools to predict CD8+ T cell specific 9 mer epitopes presented by HLA-A*02 and HLA-B40 within the highly conserved 3'-ectonucleotidase of Leishmania donovani. We identify five promiscuous epitopes, which have no homologs in humans, theoretically cover 85% of the world's population and are highly conserved (100%) among Leishmania species. Presentation of selected peptides was confirmed by T2 cell line based HLA-stabilization assay, and three of them were found to be strong binders. The in vitro peptide stimulation of peripheral blood mononuclear cells (PBMC) from cured HLA-A02+ visceral leishmaniasis (VL) subjects produced significantly higher IFN-γ, IL-2 and IL-12 compared to no peptide control healthy subjects. Further, CD8+ cells from treated VL subjects produced significantly higher intracellular IFN-γ, lymphocyte proliferation and cytotoxic activity against selected peptides from the PBMCs of treated HLA-A02+ VL subjects. Thus, the CD8+ T cell specific epitopes shown in this study will speed up the development of polytope vaccines for leishmaniasis.


Assuntos
Adenosina Trifosfatases/imunologia , Linfócitos T CD8-Positivos/imunologia , Epitopos de Linfócito T/imunologia , Leishmania donovani/imunologia , Leishmaniose Visceral/imunologia , Adolescente , Adulto , Estudos de Casos e Controles , Proliferação de Células , Feminino , Antígenos HLA-A/sangue , Antígenos HLA-A/imunologia , Humanos , Índia , Interferon gama/imunologia , Interleucina-12/imunologia , Interleucina-2/imunologia , Leishmania donovani/enzimologia , Vacinas contra Leishmaniose/imunologia , Leishmaniose Visceral/terapia , Leucócitos Mononucleares/imunologia , Ativação Linfocitária , Masculino , Pessoa de Meia-Idade , Adulto Jovem
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