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1.
PLoS Pathog ; 17(3): e1009467, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33765093

RESUMEN

Xenorhabdus hominickii, an entomopathogenic bacterium, inhibits eicosanoid biosynthesis of target insects to suppress their immune responses by inhibiting phospholipase A2 (PLA2) through binding to a damage-associated molecular pattern (DAMP) molecule called dorsal switch protein 1 (DSP1) from Spodoptera exigua, a lepidopteran insect. However, the signalling pathway between DSP1 and PLA2 remains unknown. The objective of this study was to determine whether DSP1 could activate Toll immune signalling pathway to activate PLA2 activation and whether X. hominickii metabolites could inhibit DSP1 to shutdown eicosanoid biosynthesis. Toll-Spätzle (Spz) signalling pathway includes two Spz (SeSpz1 and SeSpz2) and 10 Toll receptors (SeToll1-10) in S. exigua. Loss-of-function approach using RNA interference showed that SeSpz1 and SeToll9 played crucial roles in connecting DSP1 mediation to activate PLA2. Furthermore, a deletion mutant against SeToll9 using CRISPR/Cas9 abolished DSP1 mediation and induced significant immunosuppression. Organic extracts of X. hominickii culture broth could bind to DSP1 at a low micromolar range. Subsequent sequential fractionations along with binding assays led to the identification of seven potent compounds including 3-ethoxy-4-methoxyphenol (EMP). EMP could bind to DSP1 and prevent its translocation to plasma in response to bacterial challenge and suppress the up-regulation of PLA2 activity. These results suggest that X. hominickii inhibits DSP1 and prevents its DAMP role in activating Toll immune signalling pathway including PLA2 activation, leading to significant immunosuppression of target insects.


Asunto(s)
Alarminas/metabolismo , Proteínas Bacterianas/metabolismo , Infecciones por Bacterias Gramnegativas/metabolismo , Spodoptera/metabolismo , Xenorhabdus/metabolismo , Animales , Infecciones por Bacterias Gramnegativas/inmunología , Proteínas de Insectos/metabolismo , Fosfolipasas A2/metabolismo , Salicilatos/metabolismo , Transducción de Señal/fisiología , Spodoptera/inmunología
2.
Antonie Van Leeuwenhoek ; 116(5): 463-475, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36867270

RESUMEN

Two cream-coloured strains (JC732T, JC733) of Gram-stain negative, mesophilic, catalase and oxidase positive, aerobic bacteria which divide by budding, form crateriform structures, and cell aggregates were isolated from marine habitats of Andaman and Nicobar Islands, India. Both strains had genome size of 7.1 Mb and G + C content of 58.9%. Both strains showed highest 16S rRNA gene-based similarity with Blastopirellula retiformator Enr8T (98.7%). Strains JC732T and JC733 shared 100% identity of 16S rRNA gene and genome sequences. The coherence of both strains with the genus Blastopirellula was supported by the 16S rRNA gene based and the phylogenomic trees. Further, the chemo-taxonomic characters and the genome relatedness indices [ANI (82.4%), AAI (80.4%) and dDDH (25.2%)] also support the delineation at the species level. Both strains have the capability to degrade chitin and genome analysis shows the ability to fix N2. Based on the phylogenetic, phylogenomic, comparative genomic, morphological, physiological, and biochemical characteristics, strain JC732T is described as a new species of the genus Blastopirellula for which the name Blastopirellula sediminis sp. nov. is proposed, with strain JC733 as an additional strain.


Asunto(s)
Ácidos Grasos , Fosfolípidos , Fosfolípidos/química , Ácidos Grasos/química , Filogenia , ARN Ribosómico 16S/genética , Islas , Análisis de Secuencia de ADN , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana
3.
J Clin Biochem Nutr ; 73(2): 108-115, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37700849

RESUMEN

Quality improvement in clinical laboratories is crucial to ensure accurate and reliable test results. With increasing awareness of the potential adverse effects of errors in laboratory practice on patient outcomes, the need for continual improvement of laboratory services cannot be overemphasized. A literature search was conducted on PubMed and a web of science core collection between October and February 2021 to evaluate the scientific literature quality of clinical laboratory quality improvement; only peer-reviewed articles written in English that met quality improvement criteria were included. A structured template was used to extract data, and the papers were rated on a scale of 0-16 using the Quality Improvement Minimum Quality Criteria Set (QI-MQCS). Out of 776 studies, 726 were evaluated for clinical laboratory literature quality analysis. Studies were analyzed according to the quality improvement and control methods and interventions, such as training, education, task force, and observation. Results showed that the average score of QI-MQCS for quality improvement papers from 1981-2000 was 2.5, while from 2001-2020, it was 6.8, indicating continuous high-quality improvement in the clinical laboratory sector. However, there is still room to establish a proper system to judge the quality of clinical laboratory literature and improve accreditation programs within the sector.

4.
J Food Sci Technol ; 60(1): 243-251, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36618040

RESUMEN

This study is aimed to determine and compare the antioxidant activity of Orange Peel Powder (OPP) in ghee at different temperatures (4 °C, 25 °C and 60 °C) for divergent storage periods (0, 7, 14 and 21 days). To compare the antioxidant potentiality, synthetic antioxidant BHA (Butylated Hydroxy Anisole) is used. Twelve ghee samples were prepared where one was control, another one was BHA treated and the rest ten were admixing OPP in ghee at different ratios. After sensory evaluation three highest scored ghee samples (0.5%. 1.0% and 1.5%) were selected. Samples were analyzed for peroxide (PV), thiobarbituric acid (TBA), free fatty acids (FFA) value and radical scavenging activity. Though storage temperature and storage period were increased OPP treated ghee samples peroxide, TBA and FFA values were lowered significantly compared to control samples. Moreover, 1.0% and 1.5% OPP treated ghee samples such values were lowered than BHA treated ghee samples and all these are on the favor of ghee quality. OPP treated ghee samples' DPPH quench potentiality is also stronger than BHA treated ghee samples. Therefore, OPP is a great source of antioxidants and this can be used in ghee as a natural source of antioxidants.

5.
Pak J Pharm Sci ; 36(5(Special)): 1649-1656, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38008963

RESUMEN

In terms of delivery systems for active compounds, orally disintegrating films are a great option. The initial stage in creating an oral disintegrating film is selecting a film-forming polymer. The basic polymers combination Microcrystalline Cellulose (MCC), which is co-processed with Carboxymethylcellulose Sodium (CMC) and hydroxypropylmethyl cellulose were used to create an oral disintegrating film that contains cholecalciferol (Vitamin D3), a fat-soluble vitamin that aids in the body's absorption of calcium and phosphorus. The goal of the current inquiry was to develop orally disintegrating films of vitamin D3 to improve patient comfort and compliance for pediatric or elderly patients due to its simplicity of administration. Films containing drugs and made of the appropriate plasticizer and chosen polymers demonstrated outstanding film forming and folding endurance. The dissolution test showed that Vitamin D3 has a rapid disintegration property, with the majority of it dissolving in the medium (pH 6.8) in less than two minutes after being inserted. To verify that the films were successfully formed, a variety of procedures including HPLC, FT-IR and microscopic studies were employed. When kept at 40oC with humidity of 75%, the film showed good stability for at least three months.


Asunto(s)
Colecalciferol , Polímeros , Humanos , Niño , Anciano , Espectroscopía Infrarroja por Transformada de Fourier , Solubilidad , Polímeros/química , Derivados de la Hipromelosa/química , Administración Oral
6.
J Invertebr Pathol ; 193: 107799, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35850258

RESUMEN

Phurealipids (Photorhabdus urea lipids) are synthesized from Photorhabdus bacteria that are symbiotic to entomopathogenic nematodes. Their chemical structures are similar to that of juvenile hormone (JH) and have been suspected to mimic JH signaling in immunity and the development of insects. This study investigated the physiological roles of phurealipids with respect to their contribution to bacterial pathogenicity using four natural (HB13, HB69, HB416, and HB421) and one derivative (HB27) compound. First, phurealipids like JH suppressed insect immune responses. Overall, phurealipids showed JH like immunosuppressive behavior in a lepidopteran insect Spodoptera exigua larvae. More specifically, phurealipids significantly suppressed the hemocyte spreading behavior which is a key immune response upon immune challenge. Interestingly, the methyl urea derivatives (HB13, HB27, and HB69) were more potent than the unmethylated forms (HB416 and HB421). The inhibitory activity of phurealipids prevented the cellular immune response measured by hemocytic nodule formation in response to the bacterial challenge. Phurealipids also suppressed the expression of cecropin and gallerimycin, which are two highly inducible antimicrobial peptides, in S. exigua upon immune challenge. The immunosuppressive activity of the phurealipids significantly enhanced the bacterial pathogenicity of Bacillus thuringiensis against S. exigua. Second, phurealipids like JH prevented insect metamorphosis. Especially, the methylated urea derivatives of the phurealipids showed the JH-like function by inducing the expression of S. exigua Kr-h1, a transcriptional factor. At the pupal stage, exhibiting the lowest expression of Kr-h1, phurealipid treatments elevated the expression level of Kr-h1 and delayed the pupa-to-adult metamorphosis. These results suggest that phurealipids play crucial roles in Photorhabdus pathogenicity by suppressing host immune defenses and delaying host metamorphosis.


Asunto(s)
Hormonas Juveniles , Lípidos , Photorhabdus , Animales , Proteínas de Insectos/metabolismo , Insectos , Larva/microbiología , Metabolismo de los Lípidos , Lípidos/fisiología , Photorhabdus/metabolismo , Pupa , Urea/metabolismo
7.
Arch Microbiol ; 203(2): 741-754, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33047175

RESUMEN

Two pink-coloured, oxidase-catalase-positive, salt and alkali-tolerant planctomycetal strains (JC635T and JC645T) with pear to spherical-shaped, Gram-stain-negative, motile cells were isolated from Chilika lagoon, India. Both strains share highest 16S rRNA gene sequence identity with members of the genus Rhodopirellula (< 94%) and Roseimaritima (< 94%) of the family Pirellulaceae. The 16S rRNA sequence identity between the strains JC635T and JC645T is 96.1%. Respiratory quinone for both strains is MK6. Major fatty acids are C18:1ω9c and C16:0. Major polar lipids are phosphatidylethanolamine, phosphatidylcholine, unidentified amino lipids and an unidentified lipid. The genomic size of strain JC635T and JC645T are 7.95 Mb and 8.2 Mb with DNA G + C content of 55.1 and 60.0 mol%, respectively. Based on phylogenetic, genomic (ANI, AAI, POCP, dDDH), chemotaxonomic, physiological and biochemical characteristics, we conclude that both strains belong to a novel genus Roseiconus gen. nov. and constitute two novel species for which we propose the names Roseiconus nitratireducens sp. nov. and Roseiconus lacunae sp. nov. The two novel species are represented by the type strains JC645T (= KCTC 72174T = NBRC 113879T) and JC635T (= KCTC 72164T = NBRC 113875T), respectively.


Asunto(s)
Filogenia , Planctomycetales/clasificación , Agua de Mar/microbiología , Composición de Base , Ácidos Grasos/análisis , India , Planctomycetales/genética , ARN Ribosómico 16S/genética , Especificidad de la Especie , Microbiología del Agua
8.
Arch Insect Biochem Physiol ; 106(1): e21748, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33038048

RESUMEN

Polytrophic ovarioles of Spodoptera exigua, a lepidopteran insect, begins with the development of oocytes and differentiation of nurse cells followed by vitellogenesis and choriogenesis. Compared with previtellogenic and vitellogenic developments, choriogenesis has not been clearly understood yet in endocrine control. This study investigated the expression and function of a mucin-like structural protein of S. exigua called Se-Mucin1 in choriogenesis. It was highly expressed in ovarioles containing chorionated oocytes. The expression level of Se-Mucin1 was increased during adult stage as early as 18 h after adult emergence, reaching the maximal level at 24 h and later. Interestingly, DNA amount of Se-Mucin1 was increased by almost four folds during early adult stage while other genes (hexokinase and glyceraldehyde-3-phosphate dehydrogenase) not directly associated with chorion formation did not show genomic DNA increase, suggesting specific gene amplification of Se-Mucin1. RNA interference (RNAi) suppressed Se-Mucin1 expression by injecting 1 µg of double-strand RNA to teneral females (<5 h after emergence), which exhibited significantly impaired fecundity and egg hatching rate. Eggs laid by RNAi-treated females were malformed in eggshell structures with loss of mesh-like fibers. Treatment with aspirin, a prostaglandin (PG) biosynthesis inhibitor, suppressed the induction of Se-Mucin1 expression during early adult stage and impaired egg development. An addition of PGE2 significantly rescued such impairment in Se-Mucin1 expression and subsequent egg development. These results suggest that PGs mediate choriogenesis of S. exigua by activating the expression of chorion-associated genes including Se-Mucin1.


Asunto(s)
Dinoprostona/metabolismo , Mucinas/metabolismo , Ovario/metabolismo , Spodoptera , Animales , Aspirina/farmacología , Femenino , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo , Insectos , Mucinas/efectos de los fármacos , Mucinas/genética , Interferencia de ARN , Transducción de Señal , Spodoptera/genética , Spodoptera/metabolismo , Vitelogénesis/fisiología
9.
Gen Comp Endocrinol ; 301: 113659, 2021 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-33166533

RESUMEN

Prostaglandins (PGs) mediate physiological processes of insects as well as mammals. Prostaglandin I2 (PGI2) is a relatively well-known eicosanoid with potent hormone-like actions on various tissues of vertebrates, however, its presence and biosynthetic pathway have not been described in insects. This study demonstrated that fat bodies of the lepidopteran species, Spodoptera exigua, contained ~ 3.6 pg/g PGI2. To identify its biosynthetic pathway, a PGI2 synthase gene of S. exigua (Se-PGIS) was predicted from a transcriptome of S. exigua; 25.6% homology with human PGIS was demonstrated. Furthermore, a predicted three-dimensional structure of Se-PGIS was demonstrated to be 38.3% similar to the human PGIS ortholog, including catalytic residues. Se-PGIS was expressed in all developmental stages of S. exigua and most abundant larval and adult stages; immune challenging of larvae significantly up-regulated these expression levels. The inducible expression of Se-PGIS expression was followed by a greater than four-fold increase in the concentration of PGI2 in fat bodies 10 h after immune challenge. RNA interference (RNAi) against Se-PGIS was performed by injecting double-stranded RNA (dsRNA). Under these RNAi conditions, cellular immune responses (e.g., hemocyte-spreading behavior, nodulation, phenoloxidase activity) were not affected by bacterial challenge. The addition of PGI2 to larvae treated with an eicosanoid biosynthesis inhibitor did not rescue the immunosuppression. Interestingly, PGI2 injection significantly suppressed nodule formation in response to bacterial challenge. In addition to the negative effect of PGI2 against immunity, the Se-PGIS-RNAi treatment significantly interfered with immature development and severely impaired oocyte development in female adults; the addition of PGI2 to RNAi-treated females significantly recovered oocyte development. Se-PGIS RNAi treatment also impaired male fertility by reducing fecundity after mating with untreated females. These results suggest that PGI2 acts as a negative regulator of immune responses initiated by other factors and mediates S. exigua development and reproduction.


Asunto(s)
Inmunidad Celular , Spodoptera , Animales , Epoprostenol , Femenino , Humanos , Larva , Masculino , Prostaglandinas I
10.
Sensors (Basel) ; 21(16)2021 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-34451113

RESUMEN

In the context of active-sensing guided-wave-based acousto-ultrasound structural health monitoring, environmental and operational variability poses a considerable challenge in the damage diagnosis process as they may mask the presence of damage. In this work, the stochastic nature of guided wave propagation due to the small temperature variation, naturally occurring in the ambient or environment, is rigorously investigated and modeled with the help of stochastic time-varying time series models, for the first time, with a system identification point of view. More specifically, the output-only recursive maximum likelihood time-varying auto-regressive model (RML-TAR) is employed to investigate the uncertainty in guided wave propagation by analyzing the time-varying model parameters. The steps and facets of the identification procedure are presented, and the obtained model is used for modeling the uncertainty of the time-varying model parameters that capture the underlying dynamics of the guided waves. The stochasticity inherent in the modal properties of the system, such as natural frequencies and damping ratios, is also analyzed with the help of the identified RML-TAR model. It is stressed that the narrow-band high-frequency actuation for guided wave propagation excites more than one frequency in the system. The values and the time evolution of those frequencies are analyzed, and the associated uncertainties are also investigated. In addition, a high-fidelity finite element (FE) model was established and Monte Carlo simulations on that FE model were carried out to understand the effect of small temperature perturbation on guided wave signals.


Asunto(s)
Huesos , Método de Montecarlo , Temperatura , Ultrasonografía , Incertidumbre
11.
J Exp Biol ; 223(Pt 21)2020 11 04.
Artículo en Inglés | MEDLINE | ID: mdl-32978320

RESUMEN

Several prostaglandins (PGs) and PG-synthesizing enzymes have been identified from insects. PGs mediate cellular and humoral immune responses. However, uncontrolled and prolonged immune responses might have adverse effects on survival. PG catabolism in insects has not been reported. Here, using a transcriptomic analysis, we predicted the presence of two PG-degrading enzymes, PG dehydrogenase (SePGDH) and PG reductase (SePGR), in Spodoptera exigua, a lepidopteran insect. SePGDH and SePGR expression levels were upregulated after immune challenge. However, their expression peaks occurred after those of PG biosynthesis genes, such as those encoding PGE2 synthase or PGD2 synthase. SePGDH and SePGR expression levels were upregulated after injection with PGE2 or PGD2 In contrast, such upregulated expression was not detected after injection with leukotriene B4, an eicosanoid inflammatory mediator. RNA interference (RNAi) using double-stranded RNAs specific to SePGDH or SePGR suppressed their expression levels. The RNAi treatment resulted in an excessive and fatal melanization of larvae even after a non-pathogenic bacterial infection. Phenoloxidase (PO) activity mediating the melanization in larval plasma was induced by bacterial challenge or PGE2 injection. Although the induced PO activity decreased after 8 h in control larvae, those treated with dsRNAs specific to PG-degrading enzyme genes kept a high PO activity for a longer period. These results suggest that SePGDH and SePGR are responsible for PG degradation at a late phase of the immune response.


Asunto(s)
Inmunidad Humoral , Prostaglandinas , Animales , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo , Larva/metabolismo , Interferencia de ARN , Spodoptera/genética
12.
Gen Comp Endocrinol ; 287: 113352, 2020 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-31794733

RESUMEN

Several prostaglandins (PGs) have been identified in different insect species. However, their biosynthesis and physiological roles in insects remain unclear. PGD2 is synthesized by isomerization from PGH2 in mammals. This study identified a PGD2 synthase (SePGDS) in a lepidopteran insect, Spodoptera exigua. It showed sequence homology (32.8%) with human PGDS. Based on its conserved active site residues, its N-terminal tyrosine (Y8) was predicted to mediate electron relay from glutathione to PGH2 substrate, which was distinct from the catalysis of PGE2 (=PGD2 isomer) synthase (SePGES). SePGDS was highly expressed in larval and adult stages. RNA interference (RNAi) of SePGDS expression resulted in immunosuppression of cellular immune responses by suppressing the expression of actin polymerization-associated genes. It also suppressed the expression of some antimicrobial genes. Such immunosuppression induced by RNAi treatment was specifically rescued by the addition of PGD2, but not its precursor, arachidonic acid. Such RNAi treatment in adults prevented egg development in females by inhibiting choriogenesis. RNAi treatment also suppressed nurse cell dumping to growing oocytes. However, the addition of PGD2 rescued egg development of RNAi-treated females. These results suggest that SePGDS is responsible for the production of PGD2 which mediates immune and reproductive processes of S. exigua.


Asunto(s)
Proteínas de Insectos/metabolismo , Oxidorreductasas Intramoleculares/metabolismo , Lipocalinas/metabolismo , Animales , Femenino , Spodoptera
13.
Acta Biochim Biophys Sin (Shanghai) ; 52(6): 603-611, 2020 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-32369105

RESUMEN

Nowadays, drug-resistant microbes are becoming a serious clinical problem threatening people's health and life. Antimicrobial peptides (AMPs) are believed to be potential alternatives of conventional antibiotics to combat the threat of drug-resistant microbes. However, the susceptibility of AMPs toward proteases is one of the major problems limiting their clinical use. In the present study, we reported the effect of Cu2+ on the bioactivity of AMP HMPI. We found that the addition of Cu2+ could improve the protease resistance of AMP HMPI without affecting its bioactivity. Notably, after the binding of Cu2+ with HMPI, the hemolytic activity of HMPI was greatly decreased. In addition, our results also demonstrated that the addition of Cu2+ increased the production of reactive oxygen species in the fungal cells, which may be a supplement for the antifungal activity of HMPI. In conclusion, the introduction of Cu2+ may provide an inorganic strategy to improve the stability and decrease the hemolytic activity of AMP HMPI, while maintaining its antifungal activity.


Asunto(s)
Antifúngicos/farmacología , Péptidos Catiónicos Antimicrobianos/farmacología , Candida/crecimiento & desarrollo , Farmacorresistencia Fúngica/efectos de los fármacos , Hemólisis/efectos de los fármacos , Tripsina/farmacología , Cobre , Humanos
14.
J Food Sci Technol ; 57(9): 3244-3251, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32728272

RESUMEN

Agro-industrial waste material is a rich source of various bioactive components and fiber. Apple pomace is a by-product of apple juice processing unit. It contains a plethora of phenolic compounds and dietary fiber. The addition of apple pomace in bakery items is a judicious approach to utilize the apple juice processing industry waste material in nutritional product development. Purposely, in the current research the apple pomace was collected from the juice processing industry followed by drying at 58-60 °C. The dried pomace was ground added in wheat flour (AARI-11) at 5, 10, 15, 20 and 25% to prepare cookies. The wheat flour (AARI-11) contained crude fiber (0.57%), crude protein (10.71%) and total phenolic contents (1.35 mg/g) while apple pomace showed higher contents of dietary fiber and total phenolic contents i.e. 10.85% and 9.75 mg/g respectively. Maximum values of physical characteristics of cookies such as thickness and width were found in T0 as 1.47 mm and 5.13 mm, respectively. On the other hand, spread factor and hardness changed and maximum value was observed in T5 as 46.20 and 1555.5 n/m2 respectively. Based on the sensory and compositional attributes, it was concluded that good quality cookies with improved organoleptic properties can be prepared through using 10% apple pomace powder with wheat flour.

15.
J Exp Biol ; 222(Pt 14)2019 07 23.
Artículo en Inglés | MEDLINE | ID: mdl-31278129

RESUMEN

Prostaglandins (PGs) mediate various physiological functions in insects. Specifically, PGE2 is known to mediate immunity and egg-laying behavior in the beet armyworm, Spodoptera exigua A PGE2 synthase 2 (Se-PGES2) has been identified to catalyze the final step to produce PGE2 in S. exigua Its expression is inducible in response to immune challenge. Inhibition of the gene expression results in immunosuppression. In contrast, any physiological alteration induced by its uncontrolled overexpression was not recognized in insects. This study used the in vivo transient expression (IVTE) technique to induce overexpression and assessed subsequent physiological alteration in S. exiguaSe-PGES2 was cloned into a eukaryotic expression vector and transfected to Sf9 cells to monitor its heterologous expression. The Sf9 cells expressed the recombinant Se-PGES2 (rSe-PGES2) at an expected size (∼47 kDa), which was localized in the cytoplasm. The recombinant expression vector was then used to transfect larvae of S. exigua Hemocytes collected from the larvae treated with IVTE expressed the rSe-PGES2 gene for at least 48 h. The larvae treated with IVTE exhibited an enhanced competency in cellular immune response measured by hemocyte nodule formation. In addition, IVTE treatment of Se-PGES2 induced gene expression of antimicrobial peptides without any immune challenge. The larvae treated with IVTE became significantly resistant to infection of an entomopathogenic nematode, Steinernema monticolum, or to infection to its symbiotic bacterium, Xenorhabdus hominickii However, IVTE-treated S. exigua larvae suffered from reduced pupal size and fecundity.


Asunto(s)
Expresión Génica , Aptitud Genética/inmunología , Inmunidad Celular/genética , Proteínas de Insectos/genética , Prostaglandina-E Sintasas/genética , Spodoptera/genética , Animales , Inmunocompetencia , Proteínas de Insectos/metabolismo , Larva/enzimología , Larva/genética , Larva/inmunología , Prostaglandina-E Sintasas/metabolismo , Spodoptera/enzimología , Spodoptera/inmunología
16.
Arch Insect Biochem Physiol ; 102(4): e21607, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31338878

RESUMEN

Prostaglandin E2 (PGE2 ) mediates cellular immune responses in insects by stimulating hemocyte-spreading behavior that is driven by actin remodeling to form filopodial or lamellipodial cytoplasmic extensions. In Spodoptera exigua (Lepidoptera: Noctuidae), Cdc42, a small G protein, played a crucial role in mediating PGE2 signal on hemocyte-spreading behavior. Hemocyte-spreading behavior requires actin cytoskeletal rearrangement. A plethora of actin-related proteins have been predicted to have functional links with Cdc42. Here, we selected four actin-associated genes (Actin-related protein 2 [Arp2], Profilin, Cofilin, and Fascin) and evaluated their influences on cytoskeletal rearrangement in S. exigua. Bioinformatic analysis confirmed their gene identities. Transcript analysis using reverse-transcription polymerase chain reaction indicated that all four actin-associated genes were expressed in most developmental stages, showing high expression levels in larval hemocytes. RNA interference (RNAi) against these genes was performed by injecting double-stranded RNA (dsRNA) to hemocoel. Under RNAi condition, the hemocyte-spreading behavior was significantly impaired except for dsRNA treatment against Cofilin, an actin-depolymerizing factor. Alteration of cytoskeletal rearrangement appeared to vary after different RNAi treatments. RNAi against Arp2 markedly suppressed lamellipodial extension while RNAi against Profilin or Fascin adversely influenced filopodial extension. RNAi of these actin-associated factors prevented cellular immune responses measured by nodule formation against bacterial challenge. Under RNAi conditions, addition of PGE2 did not well induce hemocyte-spreading behavior, suggesting that these actin-associated factors might act downstream of the hormone signaling pathway. These results suggest that PGE2 can mediate hemocyte-spreading behavior via Cdc42 to activate downstream actin polymerization/branching/bundling factors, thus inducing actin cytoskeletal rearrangement.


Asunto(s)
Actinas/metabolismo , Dinoprostona/metabolismo , Hemocitos/citología , Proteínas de Insectos/metabolismo , Spodoptera/citología , Actinas/genética , Animales , Escherichia coli , Inmunidad Celular , Proteínas de Insectos/genética , Larva/metabolismo , Interferencia de ARN , Spodoptera/genética , Spodoptera/metabolismo
17.
J Invertebr Pathol ; 166: 107221, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31356819

RESUMEN

Xenorhabdus nematophila, an entomopathogenic bacterium, is mutualistic with the nematode Steinernema carpocapsae. The bacterium produces secondary metabolites to inhibit target insect phospholipase A2 (PLA2) and induce immunosuppression, which is required for the pathogenicity of this bacterium-nematode complex. However, it was unclear if immunosuppressive intensity of the bacteria was correlated with their insecticidal potency. We compared six different X. nematophila strains inhibiting the immune responses of the beet armyworm (Spodoptera exigua) to explain their virulence variations. In addition to four known strains obtained from the Korean Agricultural Culture Collection, we identified two new strains (SK1 and SK2) of X. nematophila from two different isolates of S. carpocapsae. Although all six strains were virulent, they showed significant variation in median lethal bacterial dosage (LD50). The LD50 of most strains was 15-30 CFU/larva, however, the LD50 of the SK1 strain was more than two-fold higher against S. exigua larvae. Immunosuppressive activities of the six strains were measured by comparing hemocyte-spreading behavior and nodule formation; the SK1 strain was significantly less potent than other bacterial strains. These suppressed hemocyte behaviors were recovered by adding arachidonic acid (a catalytic product of PLA2) into all six strains. Bacterial culture broth was fractionated with different organic solvents and the ability to inhibit immune response and PLA2 activity were assessed. All organic extracts had immunosuppressive activities and PLA2-inhibitory activities. GC-MS analysis showed that these organic extracts possessed a total of 87 different compounds. There were variations in chemical components among the six bacterial strains. Organic extracts of SK1 strain, which exhibited the lowest virulence, contained the least number of secondary metabolites.


Asunto(s)
Infecciones por Bacterias Gramnegativas/inmunología , Virulencia/fisiología , Xenorhabdus/inmunología , Xenorhabdus/metabolismo , Xenorhabdus/patogenicidad , Animales , Infecciones por Bacterias Gramnegativas/metabolismo , Interacciones Microbiota-Huesped/fisiología , Spodoptera/microbiología
18.
Pak J Med Sci ; 35(1): 77-81, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30881400

RESUMEN

OBJECTIVES: The aim of present study was to investigate the effect of fasting during Ramadan on plasma adiponectin and TNF-α levels. METHODS: This is a cross sectional study, conducted at Federal Urdu University of Arts, Science & Technology (FUUAST), Karachi, comprising a total of 55 (50%) females and 55 (50%) males whose ages ranged between 20 and 40 years, and fasted during Ramadan (June-July 2014) were enrolled in the study. Subjects were separated into normal weight, overweight and obese males and females. Anthropometric measurements and Fasting venous blood samples were taken at first and last (29th) day of Ramadan. Plasma adiponectin and TNF-alpha levels were assayed with ELISA kits. All values were calculated and presented as mean ± standard error of the mean (SEM) and by using analysis of variance (ANOVA) for repeated measures. P values < 0.05 were accepted as significant. RESULTS: Body mass index (BMI) (Kg/m2) in over-weight and obese male subjects exhibited considerable reduction (P<0.05; P<0.05), post Ramadan when compared to their respective pre Ramadan fasting weights. Noticeable and significant reduction was also observed in BMI of obese females (P<0.05). Post Ramadan Overweight Males (P<0.05) and Post Ramadan Obese Males (P<0.001) exhibited significantly elevated plasma adiponectin (µg/mL) values. While plasma adiponectin mean concentration of only obese females were significantly improved at last week of Ramadan (P<0.01). Fasting in Ramadan significantly decreased TNF-α (pg/mL) levels of post obese males and females than Pre-Ramadan-groups (P<0.05; P<0.01) respectively. CONCLUSION: The study reports of noticeable changes with Ramadan fasting resulting increase of plasma adiponectin and decrease of TNF-α levels as well as body weight. The study strongly suggests further investigations on larger sample sizes with possible association of dietary restrictions and weight loss on mechanism of enhanced adiponectin and reduced TNF-α in obese and overweight persons who fast on Ramadan pattern.

19.
J Invertebr Pathol ; 157: 136-146, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29802883

RESUMEN

Immunity negatively influences bacterial pathogenicity. Eicosanoids mediate both cellular and humoral immune responses in insects. This study tested a hypothesis that differential bacterial virulence of Xenorhabdus/Photorhabdus is dependent on their inhibitory activity against phospholipase A2 (PLA2) activity. P. temperata subsp. temperata ('Ptt') was more than 40 times more potent than X. hominickii ('Xh'). Although both bacteria suppressed cellular immune responses, Ptt infection suppressed hemocyte nodule formation much more than Xh infection. Their differential immunosuppression appeared to be induced by their secondary metabolites because organic extracts of Ptt-cultured broth exhibited higher inhibitory activities against cellular immune responses than Xn-cultured broth extracts. Humoral immune responses were analyzed by measuring expression levels of 11 antimicrobial peptide (AMP) genes. Among inducible AMPs in hemocytes and fat body, higher number and more kinds of AMPs exhibited lower expression levels in Ptt infection than those in Xh infection. Suppressed immune responses induced by Ptt or Xh infection were significantly rescued by the addition of a catalytic product of PLA2, suggesting that PLA2 was a common inhibitory target. In fact, Ptt infection inhibited PLA2 activity more strongly than Xh infection. RNA interference of a PLA2 gene decreased its expression and significantly increased bacterial virulence. Moreover, addition of PLA2 inhibitor to Xh infection enhanced its virulence, similar to virulence level of Ptt infection. These results suggest that variation in Xenorhabdus/Photorhabdus bacterial virulence can be explained by their differential inhibitory activities against host insect PLA2.


Asunto(s)
Fosfolipasas A2/inmunología , Photorhabdus/patogenicidad , Spodoptera/inmunología , Spodoptera/microbiología , Virulencia/inmunología , Xenorhabdus/patogenicidad , Animales , Interacciones Huésped-Patógeno/inmunología , Photorhabdus/inmunología , Xenorhabdus/inmunología
20.
Dev Comp Immunol ; 158: 105198, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38795942

RESUMEN

Immune-priming occurs in insects after a prior pathogen exposure. However, its underlying mechanism in insects remains elusive. In the present work, immune-priming was detected in a lepidopteran insect, Spodoptera exigua. Specifically, a prior infection with a heat-killed pathogenic bacterium, Escherichia coli, led to increased survival upon the second infection of different pathogens. Plasma collected from larvae with the prior infection possessed the immune-priming factor(s) that significantly up-regulated cellular and humoral immune responses of naïve larvae. Our study also finds that variations in the timing of plasma collection for priming larvae resulted in distinct impacts on both cellular and humoral responses. However, when the active plasma exhibiting the immune-priming was heat-treated, it lost this priming activity, therefore suggesting that protein factor(s) play a role in this immune-priming. An immunofluorescence assay showed that the hemocytes collected from the immune-primed larvae highly reacted to a polyclonal antibody specific to a vertebrate lipocalin, apolipoprotein D (ApoD). Among 27 ApoD genes (Se-ApoD1 âˆ¼ Se-ApoD27) of S. exigua, Se-ApoD3 was found to be highly induced during the immune-priming, in which it was shown to be expressed in hemocytes and fat body from a fluorescence in situ hybridization analysis. RNA interference of Se-ApoD3 expression significantly impaired the immune-priming of S. exigua larvae. Moreover, the inhibition of eicosanoid biosynthesis suppressed the immune-priming, in which treatment with a lipoxygenase (LOX) inhibitor-and not treatment with a cyclooxygenase inhibitor-suppressed immune-priming. Further, an addition of LOX product such as lipoxin A4 or lipoxin B4 significantly rescued the lost immune-priming activity. Taken together, these results suggest that a complex of ApoD3 and LOX product mediates the immune-priming activity of S. exigua.


Asunto(s)
Apolipoproteínas , Escherichia coli , Hemocitos , Proteínas de Insectos , Larva , Spodoptera , Animales , Spodoptera/inmunología , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Proteínas de Insectos/inmunología , Escherichia coli/inmunología , Larva/inmunología , Hemocitos/inmunología , Hemocitos/metabolismo , Apolipoproteínas/metabolismo , Apolipoproteínas/inmunología , Apolipoproteínas/genética , Inmunidad Humoral , Lipooxigenasa/metabolismo , Lipooxigenasa/genética , Lipooxigenasa/inmunología , Inmunidad Celular
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