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1.
PLoS Pathog ; 18(9): e1010880, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36178974

RESUMO

The severity of Entamoeba histolytica infection is determined by host immunology, pathogen virulence, and the intestinal environment. Conventional research for assessing pathogen virulence has been mainly performed using laboratory strains, such as a virulent HM-1: IMSS (HM-1) and an avirulent Rahman, under various artificial environmental conditions because of the difficulties of axenic isolation of the clinical strains. However, it is still unclear whether scientific knowledge based on laboratory strains are universally applicable to the true pathogenesis. Hereby, we performed transcriptomic analysis of clinical strains from patients with different degrees of disease severity, as well as HM-1 under different conditions. Even after several months of axenization, Clinical strains show the distinct profile in gene expression during in vitro passage, moreover, difference between any 2 of these strains was much greater than the changes on the liver challenge. Interestingly, 26 DEGs, which were closely related to the biological functions, were oppositely up- or down regulated between virulent Ax 19 (liver abscess) and avirulent Ax 11 (asymptomatic carrier). Additionally, RNAseq using laboratory strain (HM1) showed more than half of genes were differently expressed between continuously in vitro passaged HM1 (in vitro HM1) and periodically liver passaged HM1 (virulent HM1), which was much greater than the changes on the liver passage of virulent HM1. Also, transcriptomic analysis of a laboratory strain revealed that continuous environmental stress enhances its virulence via a shift in its gene expression profile. Changes in gene expression patterns on liver abscess formation were not consistent between clinical and laboratory strains.


Assuntos
Amebíase , Disenteria Amebiana , Entamoeba histolytica , Abscesso Hepático , Expressão Gênica , Humanos , Índice de Gravidade de Doença
2.
Parasitology ; 151(4): 429-439, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38571301

RESUMO

Entamoeba moshkovskii, according to recent studies, appears to exert a more significant impact on diarrhoeal infections than previously believed. The efficient identification and genetic characterization of E. moshkovskii isolates from endemic areas worldwide are crucial for understanding the impact of parasite genomes on amoebic infections. In this study, we employed a multilocus sequence typing system to characterize E. moshkovskii isolates, with the aim of assessing the role of genetic variation in the pathogenic potential of E. moshkovskii. We incorporated 3 potential genetic markers: KERP1, a protein rich in lysine and glutamic acid; amoebapore C (apc) and chitinase. Sequencing was attempted for all target loci in 68 positive E. moshkovskii samples, and successfully sequenced a total of 33 samples for all 3 loci. The analysis revealed 17 distinct genotypes, labelled M1­M17, across the tested samples when combining all loci. Notably, genotype M1 demonstrated a statistically significant association with diarrhoeal incidence within E. moshkovskii infection (P = 0.0394). This suggests that M1 may represent a pathogenic strain with the highest potential for causing diarrhoeal symptoms. Additionally, we have identified a few single-nucleotide polymorphisms in the studied loci that can be utilized as genetic markers for recognizing the most potentially pathogenic E. moshkovskii isolates. In our genetic diversity study, the apc locus demonstrated the highest Hd value and π value, indicating its pivotal role in reflecting the evolutionary history and adaptation of the E. moshkovskii population. Furthermore, analyses of linkage disequilibrium and recombination within the E. moshkovskii population suggested that the apc locus could play a crucial role in determining the virulence of E. moshkovskii.


Assuntos
Entamoeba , Tipagem de Sequências Multilocus , Marcadores Genéticos , Entamoeba/genética , Entamoeba/classificação , Entamoeba/isolamento & purificação , Humanos , Entamebíase/parasitologia , Entamebíase/epidemiologia , Genótipo , Polimorfismo de Nucleotídeo Único , Variação Genética , Filogenia
3.
Exp Parasitol ; 262: 108773, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38723845

RESUMO

Giardiasis is a prevalent parasitic diarrheal disease caused by Giardia lamblia, affecting people worldwide. Recently, the availability of several drugs for its treatment has highlighted issues such as multidrug resistance, limited effectiveness and undesirable side effects. Therefore, it is necessary to develop alternative new drugs and treatment strategies that can enhance therapeutic outcomes and effectively treat giardiasis. Natural compounds show promise in the search for more potent anti-giardial agents. Our investigation focused on the effect of Andrographolide (ADG), an active compound of the Andrographis paniculata plant, on Giardia lamblia, assessing trophozoite growth, morphological changes, cell cycle arrest, DNA damage and inhibition of gene expression associated with pathogenic factors. ADG demonstrated anti-Giardia activity almost equivalent to the reference drug metronidazole, with an IC50 value of 4.99 µM after 24 h of incubation. In cytotoxicity assessments and morphological examinations, it showed significant alterations in trophozoite shape and size and effectively hindered the adhesion of trophozoites. It also caused excessive ROS generation, DNA damage, cell cycle arrest and inhibited the gene expression related to pathogenesis. Our findings have revealed the anti-giardial efficacy of ADG, suggesting its potential as an agent against Giardia infections. This could offer a natural and low-risk treatment option for giardiasis, reducing the risk of side effects and drug resistance.


Assuntos
Antiprotozoários , Pontos de Checagem do Ciclo Celular , Dano ao DNA , Diterpenos , Giardia lamblia , Concentração Inibidora 50 , Espécies Reativas de Oxigênio , Trofozoítos , Diterpenos/farmacologia , Giardia lamblia/efeitos dos fármacos , Giardia lamblia/crescimento & desenvolvimento , Giardia lamblia/genética , Trofozoítos/efeitos dos fármacos , Trofozoítos/crescimento & desenvolvimento , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Dano ao DNA/efeitos dos fármacos , Antiprotozoários/farmacologia , Humanos , Animais , Expressão Gênica/efeitos dos fármacos , Metronidazol/farmacologia
4.
Antimicrob Agents Chemother ; 67(11): e0056023, 2023 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-37874291

RESUMO

Amebiasis is an important cause of morbidity and mortality worldwide, and caused by infection with the protozoan parasite Entamoeba histolytica. Metronidazole is currently the first-line drug despite adverse effects and concerns on the emergence of drug resistance. Fumagillin, a fungal metabolite from Aspergillus fumigatus, and its structurally related natural and synthetic compounds have been previously explored as potential anti-angiogenesis inhibitors for cancers, anti-microbial, and anti-obese compounds. Although fumagillin was used for human amebiasis in clinical trials in 1950s, the mode of action of fumagillin remains elusive until now. In this report, we showed that fumagillin covalently binds to methionine aminopeptidase 2 (MetAP2) and non-covalently but abundantly binds to patatin family phospholipase A (PLA). Susceptibility against fumagillin of the amebic strains in which expression of E. histolytica MetAP2 (EhMetAP2) gene was silenced increased compared to control strain. Conversely, overexpression of EhMetAP2 mutants that harbors amino acid substitutions responsible for resistance to ovalicin, a fumagillin analog, in human MetAP2, also resulted in decrease in fumagillin susceptibility. In contrast, neither gene silencing nor overexpression of E. histolytica PLA (EhPLA) affected fumagillin susceptibility. These data suggest that EhPLA is not essential and not the target of fumagillin for its amebicidal activity. Taken together, our data have demonstrated that EhMetAP2 is the primary target for amebicidal activity of fumagillin, and EhMetAP2 represents a rational explorable target for the development of alternative therapeutic agents against amebiasis.


Assuntos
Amebíase , Entamoeba histolytica , Parasitos , Animais , Humanos , Entamoeba histolytica/genética , Amebíase/tratamento farmacológico , Poliésteres
5.
Exp Parasitol ; 253: 108602, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37619808

RESUMO

The microaerotolarent amitochondriate protozoan Giardia lamblia causes Giardiasis and produces a unique enzyme called Phospholipase B (PLB) in contrast to higher eukaryotes. The enzyme is produced upon induction with oxidative (H2O2) stress, thus leading to prostaglandin E2 (PGE2) production. It exists in dimeric form, and its molecular weight is 56 kDa. This PLB was extracellularly cloned in the pET21d vector. The ORF is 1620 bp (Genbank accession no. -OM939681) long and codes for a protein 539 amino acid long, with a 15 amino acid long amino-terminal signal peptide. The highest enzyme activity of PLB was identified at pH 7.5 and 35 °C. This specific enzyme was also active at 50 °C pH 10, but activity was low. We also analyzed the expression of PLB protein in G. lamblia, which was significantly induced under increased oxidative stress.


Assuntos
Giardia lamblia , Giardíase , Humanos , Lisofosfolipase , Giardia lamblia/genética , Peróxido de Hidrogênio , Aminoácidos
6.
Parasitol Res ; 122(1): 139-144, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36308533

RESUMO

Epidemiological studies on amoebic infections are complicated by morphological overlap between the pathogenic E. histolytica, the commensal E. dispar and the amphizoic E. moshkovskii, necessitating molecular identification. The present study developed a simple and economical 18S PCR-RFLP method for the simultaneous detection and differentiation of the three species. PCR products were differentiated by Tat1 restriction digestion generating three different RFLP patterns. Validation was conducted by screening 382 faecal samples from human patients from Kolkata, India, hospitalized for diarrhoea. Analysis indicated that the PCR-RFLP could successfully differentiate between the three species and was confirmed by sequence analysis. This method could prove useful for clinical and epidemiological studies of amoebiasis.


Assuntos
Amebíase , Entamoeba histolytica , Entamoeba , Entamebíase , Humanos , Entamoeba/genética , Polimorfismo de Fragmento de Restrição , Reação em Cadeia da Polimerase/métodos , Fezes/química , DNA de Protozoário/genética , DNA de Protozoário/análise , Entamoeba histolytica/genética
7.
Parasitol Res ; 122(11): 2525-2537, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37642770

RESUMO

Amoebiasis is an infection caused by enteric protozoa, most commonly Entamoeba histolytica, and is globally considered a potentially severe and life-threatening condition. To understand the impact of the parasite genome on disease outcomes, it is important to study the genomes of infecting strains in areas with high disease prevalence. These studies aim to establish correlations between parasite genotypes and the clinical presentation of amoebiasis. We employ a strain typing approach that utilizes multiple loci, including SREHP and three polymorphic non-coding loci (tRNA-linked array N-K2 and loci 1-2 and 5-6), for high-resolution analysis. Distinct clinical phenotype isolates underwent amplification and sequencing of studied loci. The nucleotide sequences were analysed using Tandem Repeats Finder to detect short tandem repeats (STRs). These patterns were combined to assign a genotype, and the correlation between clinical phenotypes and repetitive patterns was statistically evaluated. This study found significant polymorphism in the size and number of PCR fragments at SREHP and 5-6 locus, while the 1-2 locus and NK2 locus showed variations in PCR product sizes. Out of 41 genotypes, two (I6 and I41) were significantly associated with their respective disease outcomes and were found in multiple isolates. We observed that I6 was linked with a symptomatic outcome, with a statistically significant p-value of 0.0183. Additionally, we found that I41 was associated with ALA disease outcome, with a p-value of 0.0089. Our study revealed new repeat units not previously reported, unveiling the genetic composition of E. histolytica strains in India, associated with distinct disease manifestations.


Assuntos
Entamoeba histolytica , Entamebíase , Humanos , Entamebíase/parasitologia , Polimorfismo Genético , Entamoeba histolytica/genética , Fenótipo , Repetições de Microssatélites
8.
Parasitol Res ; 122(11): 2567-2584, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37682345

RESUMO

The prevalence and genetic diversity of the protozoan pathogen Giardia duodenalis have been extensively studied worldwide. There is currently a lack of data regarding the genetic variability of the organism in eastern India. Understanding the circulating genotypes and associated risk factors is crucial for effective planning and implementing control measures. Therefore, the objective of the study was to conduct an epidemiological study to determine the prevalence and identify the various genotypes present. This survey adds to our knowledge on the occurrence and distribution of Giardia genotypes in the studied region. The overall prevalence was found to be 6.8%. This parasitic infection was significantly associated with two age groups, i.e., >0-5 years and >5-12 years. Using a multilocus genotyping method, we genotyped 52 human Giardia isolates that were obtained from diarrheal patients. Two distinct assemblages were found in the population-30.8% belonged to assemblage A; 63.5% belonged to assemblage B, prevalent in the population; and 5.7% belonged to a combined assemblage A+B. Sub-assemblage AII was found in 17.3% of the cases, followed by sub-assemblage AI (13.5%). High levels of genetic diversity were found within the population of assemblage B undergoing balancing selection. Overall, the high prevalence of the parasite observed, particularly among children, raises a major concern and necessitates implementation of robust control measures. Furthermore, we report the presence of numerous unique genotypes, circulating in this limited geographical boundary, which can be useful dataset for future studies.


Assuntos
Gastrópodes , Giardia lamblia , Giardíase , Criança , Animais , Humanos , Recém-Nascido , Lactente , Pré-Escolar , Giardia lamblia/genética , Genótipo , Giardíase/epidemiologia , Giardíase/parasitologia , Prevalência , Diarreia/epidemiologia , Índia/epidemiologia , Fezes/parasitologia , Tipagem de Sequências Multilocus , Filogenia
9.
Cell Microbiol ; 23(1): e13267, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32975360

RESUMO

Rab small GTPases regulate membrane traffic between distinct cellular compartments of all eukaryotes in a tempo-spatially specific fashion. Rab small GTPases are also involved in the regulation of cytoskeleton and signalling. Membrane traffic and cytoskeletal regulation play pivotal role in the pathogenesis of Entamoeba histolytica, which is a protozoan parasite responsible for human amebiasis. E. histolytica is unique in that its genome encodes over 100 Rab proteins, containing multiple isotypes of conserved members (e.g., Rab7) and Entamoeba-specific subgroups (e.g., RabA, B, and X). Among them, E. histolytica Rab7 is the most diversified group consisting of nine isotypes. While it was previously demonstrated that EhRab7A and EhRab7B are involved in lysosome and phagosome biogenesis, the individual roles of other Rab7 members and their coordination remain elusive. In this study, we characterised the third member of Rab7, Rab7D, to better understand the significance of the multiplicity of Rab7 isotypes in E. histolytica. Overexpression of EhRab7D caused reduction in phagocytosis of erythrocytes, trogocytosis (meaning nibbling or chewing of a portion) of live mammalian cells, and phagosome acidification and maturation. Conversely, transcriptional gene silencing of EhRab7D gene caused opposite phenotypes in phago/trogocytosis and phagosome maturation. Furthermore, EhRab7D gene silencing caused reduction in the attachment to and the motility on the collagen-coated surface. Image analysis showed that EhRab7D was occasionally associated with lysosomes and prephagosomal vacuoles, but not with mature phagosomes and trogosomes. Finally, in silico prediction of structural organisation of EhRab7 isotypes identified unique amino acid changes on the effector binding surface of EhRab7D. Taken together, our data suggest that EhRab7D plays coordinated counteracting roles: a inhibitory role in phago/trogocytosis and lyso/phago/trogosome biogenesis, and an stimulatory role in adherence and motility, presumably via interaction with unique effectors. Finally, we propose the model in which three EhRab7 isotypes are sequentially involved in phago/trogocytosis.


Assuntos
Entamoeba histolytica/genética , Entamoeba histolytica/metabolismo , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/metabolismo , Fagocitose , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Sequência de Aminoácidos , Animais , Células CHO , Cricetulus , Citoesqueleto/metabolismo , Entamoeba histolytica/patogenicidade , Entamebíase/parasitologia , Inativação Gênica , Humanos , Lisossomos/metabolismo , Membranas/metabolismo , Fagossomos/metabolismo , Transcriptoma , Vacúolos/metabolismo , Virulência , Proteínas rab de Ligação ao GTP/genética , Proteínas rab de Ligação ao GTP/metabolismo , proteínas de unión al GTP Rab7
10.
Korean J Parasitol ; 59(4): 409-413, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34470093

RESUMO

In this study, we have collected and screened a total of 268 stool samples from diarrheal patients admitted to an Infectious disease hospital in Kolkata for the presence of Cryptosporidium spp. The initial diagnosis was carried out by microscopy followed by genus specific polymerase chain reaction assays based on 70 kDa heat shock proteins (HSP70). DNA sequencing of the amplified locus has been employed for determination of genetic diversity of the local isolates. Out of 268 collected samples, 12 (4.48%) were positive for Cryptosporidium spp. Sequences analysis of 70 kDa heat shock proteins locus in 12 Cryptosporidium local isolates revealed that 2.24% and 1.86% of samples were showing 99% to 100% identity with C. parvum and C. hominis. Along with the other 2 major species one recently described globally distributed pathogenic species Cryptosporidium viatorum has been identified. The HSP70 locus sequence of the isolate showed 100% similarity with a previously described isolate of C. viatorum (Accession No. JX978274.1, JX978273.1, and JN846706.1) present in GenBank.


Assuntos
Criptosporidiose , Cryptosporidium , Criptosporidiose/diagnóstico , Cryptosporidium/genética , DNA de Protozoário/genética , Fezes , Genótipo , Humanos , Índia , Filogenia
11.
BMC Genomics ; 21(1): 813, 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33225881

RESUMO

BACKGROUND: Amoebozoa is a eukaryotic supergroup composed of unicellular and multicellular amoebic protozoa (e.g. Acanthamoeba, Dictyostelium, and Entamoeba). They are model organisms for studies in cellular and evolutionary biology and are of medical and veterinary importance. Despite their importance, Amoebozoan genome organization and genetic diversity remain poorly studied due to a lack of high-quality reference genomes. The slime mold Dictyostelium discoideum is the only Amoebozoan species whose genome is available at the chromosome-level. RESULTS: Here, we provide a near-chromosome-level assembly of the Entamoeba histolytica genome, the second semi-completed Amoebozoan genome. The availability of this improved genome allowed us to discover inter-strain heterogeneity in ploidy at the near-chromosome or sub-chromosome level among 11 clinical isolates and the reference strain. Furthermore, we observed ploidy-independent regulation of gene expression, contrary to what is observed in other organisms, where RNA levels are affected by ploidy. CONCLUSIONS: Our findings offer new insights into Entamoeba chromosome organization, ploidy, transcriptional regulation, and inter-strain variation, which will help to further decipher observed spectrums of virulence, disease symptoms, and drug sensitivity of E. histolytica isolates.


Assuntos
Entamoeba histolytica , Genoma de Protozoário , Cromossomos/genética , Entamoeba histolytica/genética , Genes de Protozoários , Ploidias , Proteínas de Protozoários/genética
12.
J Nat Prod ; 83(2): 481-488, 2020 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-32040324

RESUMO

An antimalarial lipopeptide, ikoamide, was isolated from an Okeania sp. marine cyanobacterium. Its gross structure was established by spectroscopic analyses, and the absolute configuration was clarified based on a combination of chiral-phase HPLC analyses, spectroscopic analyses, and derivatization reactions. Ikoamide showed strong antimalarial activity with an IC50 value of 0.14 µM without cytotoxicity against human cancer cell lines at 10 µM.


Assuntos
Antimaláricos/farmacologia , Cianobactérias/química , Lipopeptídeos/química , Antimaláricos/química , Cromatografia Líquida de Alta Pressão , Humanos , Lipopeptídeos/isolamento & purificação , Estrutura Molecular , Relação Estrutura-Atividade
13.
J Stroke Cerebrovasc Dis ; 29(5): 104743, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32127256

RESUMO

BACKGROUND: Bone marrow stromal cell (BMSC) transplantation is a promising therapeutic approach for cerebral ischemia, as it elicits multiple neuroprotective effects. However, it remains unclear how BMSC transplantation modulates the ubiquitin-proteasome system (UPS) and autophagy under cerebral ischemia. METHODS: In the present study, an intermediate level of cerebral ischemia (30 minutes) was chosen to examine the effect of BMSC transplantation on the molecular switch regulating UPS and autophagy. BMSC or vehicle was stereotactically injected into the penumbra 15 minutes after sham operation or transient middle cerebral artery occlusion (tMCAO). RESULTS: Thirty minutes of tMCAO artery occlusion significantly increased TUNEL-, ubiquitin-, and p62-positive cells (which peaked at 72 hours, 2 hours, and 2 hours after reperfusion, respectively) and ratios of both BAG3/BAG1 and LC3-II/LC3-I at 24 hours after reperfusion. However, intracerebral injection of BMSCs significantly reduced infarct volume and numbers of TUNEL- and p62-positive cells, and improved BAG3/BAG1 and LC3-II/LC3-I ratios. In addition, observed increases in ubiquitin-positive cells 2 hours after reperfusion were slightly suppressed by BMSC transplantation. CONCLUSIONS: These data suggest a protective role of BMSC transplantation, which drove the molecular switch from autophagy to UPS in a murine model of ischemic stroke.


Assuntos
Autofagia , Encéfalo/enzimologia , Infarto da Artéria Cerebral Média/cirurgia , Transplante de Células-Tronco Mesenquimais , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Apoptose , Proteínas Reguladoras de Apoptose/metabolismo , Encéfalo/patologia , Células Cultivadas , Proteínas de Ligação a DNA/metabolismo , Modelos Animais de Doenças , Infarto da Artéria Cerebral Média/enzimologia , Infarto da Artéria Cerebral Média/patologia , Masculino , Camundongos Endogâmicos C57BL , Proteínas Associadas aos Microtúbulos/metabolismo , Proteína Sequestossoma-1/metabolismo , Transdução de Sinais , Fatores de Tempo , Fatores de Transcrição/metabolismo , Ubiquitinação
14.
J Neurosci Res ; 97(5): 607-619, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30565312

RESUMO

Oxidative stress is associated with the degeneration of both motor neurons and skeletal muscles in amyotrophic lateral sclerosis (ALS). A free radical scavenger edaravone has been proven as a therapeutic drug for ALS patients, but the neuroprotective mechanism for the oxidative stress of ALS has not been fully investigated. In this study, we investigated oxidative stress in ALS model mice bearing both oxidative stress sensor nuclear erythroid 2-related factor 2 (Nrf2) and G93A-human Cu/Zn superoxide dismutase (Nrf2/G93A) treated by edaravone. In vivo Nrf2 imaging analysis showed the accelerated oxidative stress both in spinal motor neurons and lower limb muscles of Nrf2/G93A mice according to disease progression in addition to the enhancement of serum oxidative stress marker dROMS. These were significantly alleviated by edaravone treatment accompanied by clinical improvements (rotarod test). The present study suggests that in vivo optical imaging of Nrf2 is useful for detecting oxidative stress in ALS, and edaravone alleviates the degeneration of both motor neurons and muscles related to oxidative stress in ALS patients.


Assuntos
Esclerose Lateral Amiotrófica/tratamento farmacológico , Esclerose Lateral Amiotrófica/metabolismo , Edaravone/farmacologia , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Esclerose Lateral Amiotrófica/patologia , Animais , Atrofia , Feminino , Histona Desacetilases/metabolismo , Humanos , Longevidade/efeitos dos fármacos , Masculino , Camundongos , Camundongos Transgênicos , Fator 2 Relacionado a NF-E2/metabolismo , Superóxido Dismutase/metabolismo , Superóxido Dismutase-1/metabolismo
15.
J Nat Prod ; 82(10): 2907-2915, 2019 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-31549837

RESUMO

The bioassay-guided fractionation of an Okeania sp. marine cyanobacterium collected in Okinawa led to the isolation of the lipopeptide mabuniamide (1). The gross structure of 1 was determined by spectroscopic analyses, and its absolute configuration was determined using Marfey's analysis of the acid hydrolysate of 1. The absolute configuration of 1 was confirmed by total synthesis. Mabuniamide (1) stimulated glucose uptake in cultured rat L6 myotubes. In addition, mabuniamide (1) and its stereoisomer (2) exhibited moderate antimalarial activity.


Assuntos
Cianobactérias/química , Lipopeptídeos/isolamento & purificação , Animais , Antimaláricos/farmacologia , Células Cultivadas , Lipopeptídeos/síntese química , Lipopeptídeos/farmacologia , Biologia Marinha , Conformação Molecular , Ratos
16.
J Neurosci Res ; 96(10): 1707-1716, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30102416

RESUMO

Sigma-1 receptor (Sig-1R) is expressed at endoplasmic reticulum (ER) membranes, where it regulates a variety of specific physiological functions. However, the profile and exact roles of ER stress-related molecules after Sig-1R agonist treatment in an in vivo stroke model are largely unknown. The aim of this study is to investigate the effect of a novel Sig-1R agonist, aniline derivative compound (Comp-AD), on the ER stress response following ischemic stroke. Male C57BL/6J mice received transient middle cerebral artery occlusion for 90 min, and were then treated with vehicle saline or Comp-AD at reperfusion. At 3 hr, 1 day, and 7 days after reperfusion, immunohis- tochemistry was performed for Sig-1R and ER stress-related proteins including phospho protein kinase RNA-like endoplasmic reticulum kinase (p-PERK), phospho inositol requiring enzyme 1α (p- IRE1α), and activating transcription factor 6 (ATF6). Neurobehavioral analysis showed improved functional recovery at 1 day and 7 days after reperfusion, and the infarct volume was significantly smaller at 7 days (p < .05), in the Comp-AD group compared with the vehicle group. Comp-AD treatment upregulated Sig-1R immunoreactivity at 3 hr and 1 day (p < .05), and reduced p-PERK and p-IRE1α expression at 1 day (p < .05, respectively), in the peri-ischemic region compared with the vehicle group. Treatment with the novel Sig-1R agonist Comp-AD was neuroprotective after transient middle cerebral artery occlusion, and was associated with upregulation of Sig-1R and a reduction of ER stress.


Assuntos
Compostos de Anilina/farmacologia , Infarto Encefálico/tratamento farmacológico , Isquemia Encefálica/tratamento farmacológico , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Receptores sigma/agonistas , Animais , Infarto Encefálico/metabolismo , Infarto Encefálico/fisiopatologia , Isquemia Encefálica/metabolismo , Isquemia Encefálica/fisiopatologia , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Endorribonucleases/metabolismo , Infarto da Artéria Cerebral Média/tratamento farmacológico , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Atividade Motora/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/metabolismo , Distribuição Aleatória , Receptores sigma/metabolismo , Transdução de Sinais/efeitos dos fármacos , eIF-2 Quinase/metabolismo , Receptor Sigma-1
17.
J Neurosci Res ; 96(12): 1887-1899, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30242877

RESUMO

Stachybotrys microspora triprenyl phenol (SMTP)-44D has both anti-oxidative and anti-inflammatory activities, but its efficacy has not been proved in relation to the pathological changes of neurovascular unit (NVU) and neurovascular trophic coupling (NVTC) in ischemic stroke. Here, the present study was designed to assess the efficacies of SMTP-44D, moreover, compared with the standard neuroprotective reagent edaravone in ischemic brains. ICR mice were subjected to transient middle cerebral artery occlusion (tMCAO) for 60 min, SMTP-44D (10 mg/kg) or edaravone (3 mg/kg) was intravenously administrated through subclavian vein just after the reperfusion, and these mice were examined at 1, 3, and 7 d after reperfusion. Compared with the vehicle group, SMTP-44D treatment revealed obvious ameliorations in clinical scores and infarct volume, meanwhile, markedly suppressed the accumulations of 4-HNE, 8-OHdG, nitrotyrosine, RAGE, TNF-α, Iba-1, and cleaved caspase-3 after tMCAO. In addition, SMTP-44D significantly prevented the dissociation of NVU and improved the intensity of NAGO/BDNF and the number of BDNF/TrkB and BDNF/NeuN double positive cells. These effects of SMTP-44D in reducing oxidative and inflammatory stresses were similar to or stronger than those of edaravone. The present study demonstrated that SMTP-44D showed strong anti-oxidative, anti-inflammatory, and anti-apoptotic effects, moreover, the drug also significantly improved the NVU damage and NVTC in the ischemic brain.


Assuntos
Infarto Encefálico/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Fenóis/farmacologia , Acidente Vascular Cerebral/tratamento farmacológico , Acetilglucosamina/metabolismo , Animais , Apoptose/efeitos dos fármacos , Vasos Sanguíneos/efeitos dos fármacos , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Proteínas de Ligação ao Cálcio/efeitos dos fármacos , Caspase 3/efeitos dos fármacos , Proteínas de Ligação a DNA , Fibrinolíticos/farmacologia , Infarto da Artéria Cerebral Média/tratamento farmacológico , Infarto da Artéria Cerebral Média/patologia , Masculino , Camundongos , Camundongos Endogâmicos ICR , Proteínas dos Microfilamentos/efeitos dos fármacos , Proteínas do Tecido Nervoso/metabolismo , Proteínas Nucleares/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Piroptose/efeitos dos fármacos , Stachybotrys , Ativador de Plasminogênio Tecidual/farmacologia , Fator de Necrose Tumoral alfa/efeitos dos fármacos
18.
J Nat Prod ; 81(11): 2545-2552, 2018 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-30387355

RESUMO

Hoshinoamides A (1) and B (2), new acyclic lipopeptides, were isolated from the marine cyanobacterium Caldora penicillata. Their structures were elucidated by spectroscopic analyses and degradation reactions. Hoshinoamides A (1) and B (2) did not exhibit any cytotoxicity against HeLa cells at 10 µM, but inhibited the in vitro growth of the malarial parasite Plasmodium falciparum (IC50 = 0.52 and 1.0 µM, respectively).


Assuntos
Cianobactérias/química , Lipopeptídeos/isolamento & purificação , Lipopeptídeos/farmacologia , Água do Mar/microbiologia , Células HeLa , Humanos , Microbiologia da Água
19.
Int J Mol Sci ; 19(12)2018 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-30513690

RESUMO

Membrane traffic plays a pivotal role in virulence in the enteric protozoan parasite Entamoeba histolytica. EhRab8A small GTPase is a key regulator of membrane traffic at the endoplasmic reticulum (ER) of this protist and is involved in the transport of plasma membrane proteins. Here we identified the binding proteins of EhRab8A. The Cdc50 homolog, a non-catalytic subunit of lipid flippase, was identified as an EhRab8A binding protein candidate by affinity coimmunoprecipitation. Binding of EhRab8A to EhCdc50 was also confirmed by reciprocal immunoprecipitation and blue-native polyacrylamide gel electrophoresis, the latter of which revealed an 87 kDa complex. Indirect immunofluorescence imaging with and without Triton X100 showed that endogenous EhCdc50 localized on the surface in the absence of permeabilizing agent but was observed on the intracellular structures and overlapped with the ER marker Bip when Triton X100 was used. Overexpression of N-terminal HA-tagged EhCdc50 impaired its translocation to the plasma membrane and caused its accumulation in the ER. As reported previously in other organisms, overexpression and accumulation of Cdc50 in the ER likely inhibited surface transport and function of the plasma membrane lipid flippase P4-ATPase. Interestingly, HA-EhCdc50-expressing trophozoites gained resistance to miltefosine, which is consistent with the prediction that HA-EhCdc50 overexpression caused its accumulation in the ER and mislocalization of the unidentified lipid flippase. Similarly, EhRab8A gene silenced trophozoites showed increased resistance to miltefosine, supporting EhRab8A-dependent transport of EhCdc50. This study demonstrated for the first time that EhRab8A mediates the transport of EhCdc50 and lipid flippase P4-ATPase from the ER to the plasma membrane.


Assuntos
Entamoeba histolytica/metabolismo , ATPases do Tipo-P/metabolismo , Proteínas de Protozoários/metabolismo , Proteínas rab de Ligação ao GTP/metabolismo , Retículo Endoplasmático/metabolismo , Entamoeba histolytica/genética , ATPases do Tipo-P/genética , Proteínas de Protozoários/genética , Proteínas rab de Ligação ao GTP/genética
20.
J Stroke Cerebrovasc Dis ; 27(8): 2096-2105, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29793801

RESUMO

BACKGROUND: Dietary supplement is an attempt to reduce the risk of ischemic stroke in high-risk population. A new mixed vitamin E-Tocovid that mainly contains tocotrienols other than tocopherol, attenuated the progression of white matter lesions by oral in humans. However, the effect of Tocovid on ischemic stroke has not been examined. In the present study, we assessed the therapeutic effects of Tocovid pretreatment on transient middle cerebral artery occlusion (tMCAO) in mice. MATERIALS AND METHODS: After pretreatment with Tocovid (200 mg/kg/d) or vehicle for 1 month, 60-minute tMCAO was performed, and these mice were examined at 1 day, 3 days, and 7 days after reperfusion. We histologically assessed the effects of Tocovid pretreatment on the expressive changes of oxidative stress markers, cleaved caspase-3, and LC3-II after tMCAO in mice. RESULTS: We observed that Tocovid pretreatment significantly improved the rotarod time, reduced infarct volume, decreased the number of 4-HNE, nitrotyrosine, and 8-OhdG positive cells, inhibited advanced glycation end products biomarkers RAGE, CMA, and CML expressions, and increased Nrf2 and MRP1 levels with GSSG/GSH ratio decrease. Furthermore, Tocovid pretreatment greatly decreased cleaved caspase-3 and LC3-II expressions after tMCAO. CONCLUSIONS: The present study obviously demonstrated that Tocovid pretreatment showed neuroprotective effects against oxidative stress and at least in part by antiapoptotic/autophagic cell death in ischemic mice brain.


Assuntos
Antioxidantes/farmacologia , Infarto da Artéria Cerebral Média/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Tocotrienóis/farmacologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Caspase 3/metabolismo , Modelos Animais de Doenças , Glutationa/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Infarto da Artéria Cerebral Média/metabolismo , Infarto da Artéria Cerebral Média/patologia , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Masculino , Camundongos Endogâmicos ICR , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/fisiologia , Distribuição Aleatória , Teste de Desempenho do Rota-Rod , Fatores de Tempo
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