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The double stranded RNA binding protein Adad1 (adenosine deaminase domain containing 1) is a member of the adenosine deaminase acting on RNAs (Adar) protein family with germ cell-specific expression. In mice, Adad1 is necessary for sperm differentiation, however its function outside of mammals has not been investigated. Here, through an N-ethyl-N-nitrosourea (ENU) based forward genetic screen, we identified an adad1 mutant zebrafish line that develops as sterile males. Further histological examination revealed complete lack of germ cells in adult mutant fish, however germ cells populated the gonad, proliferated, and entered meiosis in larval and juvenile fish. Although meiosis was initiated in adad1 mutant testes, the spermatocytes failed to progress beyond the zygotene stage. Thus, Adad1 is essential for meiosis and germline maintenance in zebrafish. We tested if spermatogonial stem cells were affected using nanos2 RNA FISH and a label retaining cell (LRC) assay, and found that the mutant testes had fewer LRCs and nanos2-expressing cells compared to wild-type siblings, suggesting that failure to maintain the spermatogonial stem cells resulted in germ cell loss by adulthood. To identify potential molecular processes regulated by Adad1, we sequenced bulk mRNA from mutants and wild-type testes and found mis-regulation of genes involved in RNA stability and modification, pointing to a potential broader role in post-transcriptional regulation. Our findings suggest that the RNA regulatory protein Adad1 is required for fertility through regulation of spermatogonial stem cell maintenance in zebrafish.
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Adenosina Desaminasa , Pez Cebra , Animales , Masculino , Ratones , Adenosina Desaminasa/metabolismo , Células Germinativas/metabolismo , Mamíferos/genética , Meiosis/genética , ARN/metabolismo , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Semen/metabolismo , Testículo/metabolismo , Pez Cebra/metabolismo , Proteínas de Pez Cebra/metabolismoRESUMEN
High-latitude ecosystems are warming faster than other biomes and are often dominated by a ground layer of Ericaceous shrubs, which can respond positively to warming. The carbon-for-nitrogen (C-for-N) exchange between Ericaceous shrubs and root-associated fungi may underlie shrub responses to warming, but has been understudied. In a glasshouse setting, we examined the effects of warming on the C-for-N exchange between the Ericaceous shrub Empetrum nigrum ssp. hermaphroditum and its root-associated fungi. We applied different 13 C and 15 N isotope labels, including a simple organic N form (glycine) and a complex organic N form (moss litter) and quantified their assimilation into soil, plant biomass, and root fungal biomass pools. We found that warming lowered the amount of 13 C partitioned to root-associated fungi per unit of glycine 15 N assimilated by E. nigrum, but only in the short term. By contrast, warming increased the amount of 13 C partitioned to root-associated fungi per unit of moss 15 N assimilated by E. nigrum. Our study suggests that climate warming affects the short-term exchange of C and N between a widespread Ericaceous shrub and root-associated fungi. Furthermore, while most isotope tracing studies use labile N sources, we demonstrate that a ubiquitous recalcitrant N source may produce contrasting results.
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Ecosistema , Nitrógeno , Carbono , Suelo , Hongos , Isótopos , GlicinaRESUMEN
PURPOSE OF REVIEW: Diabetic neuropathy is a common complication of diabetes mellitus (DM) and can affect up to 50% of DM patients during their lifetime. Patients typically present with numbness, tingling, pain, and loss of sensation in the extremities. Since there is no treatment targeting the underlying mechanism of neuropathy, strategies focus on preventative care and pain management. RECENT FINDINGS: Up to 69% of patients with diabetic neuropathy receive pharmacological treatment for neuropathic pain. The United States Food and Drug Administration (FDA) confirmed four drugs for painful diabetic neuropathy (PDN): pregabalin, duloxetine, tapentadol, and the 8% capsaicin patch. Nonpharmacological treatments such as spinal cord stimulation (SCS) and transcutaneous electrical nerve stimulation (TENS) both show promise in reducing pain in DM patients. Despite the high burden associated with PDN, effective management remains challenging. This update covers the background and management of diabetic neuropathy, including its epidemiology, pathogenesis, preventative care, and current therapeutic strategies.
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Amla (Phyllanthus emblica) has long been used in traditional folk medicine to prevent and cure a variety of inflammatory diseases. In this study, the antioxidant activity (DPPH scavenging and reducing power), anti-inflammatory activity (RBC Membrane Stabilization and 15-LOX inhibition), and anticoagulation activity (Serin protease inhibition and Prothrombin Time assays) of the methanolic extract of amla were conducted. Amla exhibited a substantial amount of phenolic content (TPC: 663.53 mg GAE/g) and flavonoid content (TFC: 418.89 mg GAE/g). A strong DPPH scavenging effect was observed with an IC50 of 311.31 µg/ml as compared to standard ascorbic acid with an IC50 of 130.53 µg/ml. In reducing power assay, the EC50 value of the extract was found to be 196.20 µg/ml compared to standard ascorbic acid (EC50 = 33.83 µg/ml). The IC50 value of the RBC membrane stabilization and 15-LOX assays was observed as 101.08 µg/ml (IC50 of 58.62 µg/ml for standard aspirin) and 195.98 µg/ml (IC50 of 19.62 µg/ml for standard quercetin), respectively. The extract also strongly inhibited serine protease (trypsin) activity with an IC50 of 505.81 µg/ml (IC50 of 295.44 µg/ml for standard quercetin). The blood coagulation time (PTT) was found to be 11.91 min for amla extract and 24.11 min for standard Warfarin. Thus, the findings of an in vitro study revealed that the methanolic extract of amla contains significant antioxidant, anti-inflammatory, and anticoagulation activity. Furthermore, in silico docking and simulation of reported phytochemicals of amla with human 15-LOXA and 15-LOXB were carried out to validate the anti-inflammatory activity of amla. In this analysis, epicatechin and catechin showed greater molecular interaction and were considerably stable throughout the 100 ns simulation with 15-lipoxygenase A (15-LOXA) and 15-lipoxygenase B (15-LOXB) respectively.
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BACKGROUND: Children in resource-limited settings remain vulnerable to zinc deficiency and its consequences. OBJECTIVES: To evaluate the effects of different doses, durations, and frequencies of zinc supplementation on the incidence of diarrhea and change in linear growth among young children. METHODS: We conducted a randomized, partially double-blind, controlled, 6-arm, community-based efficacy trial in Dhaka, Bangladesh. Children aged 9-11 mo were randomly assigned to receive 1 of the following interventions for 24 wk: 1) standard micronutrient powder (MNP) containing 4.1 mg zinc and 10 mg iron, daily; 2) high-zinc (10 mg), low-iron (6 mg) (HiZn LoFe) MNP, daily; 3) HiZn (10 mg) LoFe (6 mg)/HiZn (10 mg), no-iron MNPs on alternating days; 4) dispersible zinc tablet (10 mg), daily; 5) dispersible zinc tablet (10 mg), daily for 2 wk at enrollment and 12 wk; 6) placebo powder, daily. Primary outcomes were incidence of diarrhea and change in length-for-age z-score (LAZ) over the 24-wk intervention period. Home visits were conducted twice weekly to assess diarrhea and other morbidity. Incidence and prevalence outcomes were compared among groups with Poisson regression; continuous outcomes were compared using ANCOVA. RESULTS: A total of 2886 children were enrolled between February 2018 and July 2019. The mean incidence and prevalence of diarrhea among all participants was 1.21 episodes per 100 d and 3.76 d per 100 d, respectively. There were no differences in the incidence or prevalence of diarrhea across intervention groups. The decline in LAZ was slightly smaller among children in the daily HiZn LoFe MNP group compared with the placebo powder group (P < 0.05). CONCLUSIONS: The dose of zinc in MNPs as well as the duration and frequency of supplementation evaluated in this trial were not effective in reducing diarrhea; however, the daily HiZn LoFe MNP formulation offered modest improvements in linear growth among young children. This trial was registered at clinicaltrials.gov as NCT03406793.
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Oligoelementos , Zinc , Bangladesh/epidemiología , Niño , Preescolar , Diarrea/epidemiología , Diarrea/prevención & control , Suplementos Dietéticos , Método Doble Ciego , Humanos , Lactante , Hierro , Micronutrientes , Polvos , Comprimidos , Oligoelementos/uso terapéuticoRESUMEN
BACKGROUND: Currently there are no standard of care treatment strategies for IH prevention (IHP). Dehydrated human amnion-chorion (dHACM) is a healing adjunct that elutes growth factors including several that have reduced IH in animal models. We therefore performed a double-blinded, prospective randomized controlled trial (RCT) to test the hypothesis that dHACM significantly reduces IH formation in a well-studied animal model of acute IH. MATERIAL AND METHODS: Forty 16-week-old male Sprague-Dawley rats were randomized to one of four groups: No Treatment vs. dHACM Sheet (Group A), and Saline vs. dHACM Injection (Group B). Each animal underwent a 5-cm midline laparotomy which was incompletely closed with 5-0 plain gut sutures; this was performed by a surgeon blinded to treatment group (first blind). After 28 days, the primary endpoints of IH formation and hernia size were determined by study staff blinded to treatment (second blind). Secondary endpoints included healed fascia tensile strength as determined by tensiometry, systemic and local inflammatory markers as measured by ELISA, and fascial scar collagen I/III ratios per Western blotting. RESULTS: In Group A, No Treatment developed IH at 87.5% vs. 62.5% for Sheet (P = 0.28). Hernias that formed in the Sheet group were significantly smaller (P = 0.036). In Group B, Injection and Saline yielded identical IH rates of 77.8%. Molecular characterization of fascial scar demonstrated non-inferior tensile strength, collagen I/III ratios, and inflammatory markers in dHACM-treated animals. CONCLUSIONS: dHACM sheets significantly reduced the size of IH following laparotomy when compared to no treatment.
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Hernia Incisional , Amnios , Animales , Corion , Modelos Animales de Enfermedad , Humanos , Masculino , Ratas , Ratas Sprague-DawleyRESUMEN
Recent evidence has prompted the notion of gut-microbial signatures as an indirect marker of aging and aging-associated decline in humans. However, the underlying host-symbiont molecular interactions contributing to these signatures remain poorly understood. In this study, we address this gap using cheminformatic analyses to elucidate potential gut microbial metabolites that may perturb the longevity-associated NAD+ metabolic network. In silico ADMET, KEGG interaction analysis, molecular docking, molecular dynamics simulation, and molecular mechanics calculation predict a large number of safe and bioavailable microbial metabolites to be direct and/or indirect activators of NAD+-dependent sirtuin proteins. Our simulation results suggest dihydropteroate, phenylpyruvic acid, indole-3-propionic acid, phenyllactic acid, all-trans-retinoic acid, and multiple deoxy-, methyl-, and cyclic nucleotides from intestinal microbiota as the best-performing regulators of NAD+ metabolism. Retracing these molecules to their source microorganisms also suggest commensal Escherichia, Bacteroides, Bifidobacteria, and Lactobacilli to be associated with the highest number of pro-longevity metabolites. These findings from our early-stage study, therefore, provide an informatics-based context for previous evidence in the area and grant novel insights for future clinical investigation intersecting anti-aging drug discovery, probiotics, and gut microbial signatures.
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Microbioma Gastrointestinal , Longevidad , NAD/metabolismo , Algoritmos , Simulación por Computador , Humanos , Ligandos , Simulación del Acoplamiento Molecular , Simulación de Dinámica MolecularRESUMEN
BACKGROUND: The association of circulating lipids with breast cancer is being debated. The objective of this study was to examine the relationship between abnormal plasma lipids and breast cancer risk in Bangladeshi women. METHODS: This was a case-control study designed using a population of 150 women (50 women in each group). The lipid levels of women with breast cancer were compared to the lipid levels of women with benign breast disease (control group 1) and healthy women (control group 2). Study samples were collected from the Department of Surgery, Bangabandhu Sheikh Mujib Medical University, for a period of 1 year. Ethical measures were in compliance with the current Declaration of Helsinki. Statistical analysis was performed with SPSS version 26. RESULTS: All of the comparison groups shared similar sociodemographic, anthropometric and obstetric characteristics. The incidence of dyslipidemia was significantly higher in breast cancer patients (96%) than in healthy women (84%) and patients with benign breast disease (82%) (P < 0.05 for both). The levels of total cholesterol, triglycerides, and low-density lipoprotein (LDL) cholesterol among the breast cancer patient group were significantly higher than those among both benign breast disease patients and healthy women (P < 0.05), except for high-density lipoprotein (HDL) cholesterol. Adjusting for other factors, body mass index (BMI) (kg/m2) (> 23) [OR 53.65; 95% CI: 5.70-504.73; P < 0.001] and total cholesterol (mg/dl) (≥ 200) [OR 16.05; 95% CI: 3.13-82.29; P < 0.001] were independently associated with breast cancer. CONCLUSIONS: Total cholesterol and BMI are independent predictors of breast cancer risk among Bangladeshi women.
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Neoplasias de la Mama/sangre , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Hiperlipidemias/sangre , Neoplasias/sangre , Triglicéridos/sangre , Adulto , Antropometría , Bangladesh , Biomarcadores de Tumor/sangre , Índice de Masa Corporal , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/patología , Estudios de Casos y Controles , Femenino , Humanos , Hiperlipidemias/diagnóstico , Hiperlipidemias/patología , Persona de Mediana Edad , Neoplasias/diagnóstico , Neoplasias/patologíaRESUMEN
This study examined the nature and correlates of child marriage in eight villages in climate-affected coastal Bangladesh using a mixed-methods approach: focus group discussions and in-depth qualitative interviews of female victims of child marriage as well as quantitative data collected using structured interviews of households. More than two-thirds of the qualitative survey respondents had encountered at least one event of natural disaster before marriage. Quantitative data confirmed significantly higher exposure to flood and river erosion among the coastal population. The quantitative data also suggested a positive association between shocks related to climate events and the incidence of child marriage, while the qualitative data indicated multiple themes related to the causes of child marriage, such as economic vulnerability, coping with risk and patriarchal norms. Yet the qualitative study respondents did not directly refer to natural disasters and climate changes when narrating their marital histories. The qualitative and quantitative evidence does not suggest that dowry-related factors are leading to early marriage. Rather, child marriage appears to be a coping strategy adopted by households in response to their increased vulnerability to natural disasters.
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Matrimonio , Desastres Naturales , Bangladesh , Niño , Cambio Climático , Femenino , Inundaciones , HumanosRESUMEN
Neutrophils form sticky web-like structures known as neutrophil extracellular traps (NETs) as part of innate immune response. NETs are decondensed extracellular chromatin filaments comprising nuclear and cytoplasmic proteins. NETs have been implicated in many gastrointestinal diseases including colorectal cancer (CRC). However, the regulatory mechanisms of NET formation and potential pharmacological inhibitors in the context of CRC have not been thoroughly discussed. In this review, we intend to highlight roles of NETs in CRC progression and metastasis as well as the potential of targeting NETs during colon cancer therapy.
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Neoplasias Colorrectales/inmunología , Neoplasias Colorrectales/patología , Trampas Extracelulares/inmunología , Neutrófilos/inmunología , Neutrófilos/patología , Animales , Progresión de la Enfermedad , Trampas Extracelulares/fisiología , Humanos , Metástasis de la Neoplasia/inmunologíaRESUMEN
The calcium-sensing receptor (CaSR) is critical for skeletal development, but its mechanism of action in osteoblasts is not well-characterized. In the central nervous system (CNS), Homer scaffolding proteins form signaling complexes with two CaSR-related members of the G protein-coupled receptor (GPCR) family C, metabotropic glutamate receptor 1 (mGluR1) and mGluR5. Here, we show that CaSR and Homer1 are co-expressed in mineralized mouse bone and also co-localize in primary human osteoblasts. Co-immunoprecipitation experiments confirmed that Homer1 associates with CaSR in primary human osteoblasts. The CaSR-Homer1 protein complex, whose formation was increased in response to extracellular Ca2+, was bound to mechanistic target of rapamycin (mTOR) complex 2 (mTORC2), a protein kinase that phosphorylates and activates AKT Ser/Thr kinase (AKT) at Ser473 siRNA-based gene-silencing assays with primary osteoblasts revealed that both CaSR and Homer1 are required for extracellular Ca2+-stimulated AKT phosphorylation and thereby inhibit apoptosis and promote AKT-dependent ß-catenin stabilization and cellular differentiation. To confirm the role of the CaSR-Homer1 complex in AKT initiation, we show that in HEK-293 cells, co-transfection with both Homer1c and CaSR, but neither with Homer1c nor CaSR alone, establishes sensitivity of AKT-Ser473 phosphorylation to increases in extracellular Ca2+ concentrations. These findings indicate that Homer1 mediates CaSR-dependent AKT activation via mTORC2 and thereby stabilizes ß-catenin in osteoblasts.
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Proteínas de Andamiaje Homer/metabolismo , Diana Mecanicista del Complejo 2 de la Rapamicina/metabolismo , Osteoblastos/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Receptores Sensibles al Calcio/metabolismo , beta Catenina/metabolismo , Animales , Apoptosis/fisiología , Calcio/metabolismo , Femenino , Células HEK293 , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Fosforilación , Receptores Sensibles al Calcio/genética , Transducción de Señal , Serina-Treonina Quinasas TOR/metabolismoRESUMEN
Evidence of the impact of community-based nutrition programs is uncommon for two main reasons: the lack of untreated controls, and implementation does not account for the evaluation design. Suchana is a large-scale program to prevent malnutrition in children in Sylhet division, Bangladesh by improving the livelihoods and nutrition knowledge of poor and very poor households. Suchana is being implemented in 157 unions, the smallest administrative unit of government, in two districts of Sylhet. Suchana will deliver a package of interventions to poor people in about 40 randomly selected new unions annually over 4 years, until all are covered. All beneficiaries will receive the normal government nutrition services. For evaluation purposes the last 40 unions will act as a control for the first 40 intervention unions. The remaining unions will receive the program but will not take part in the evaluation. A baseline survey was conducted in both intervention and control unions; it will be repeated after 3 years to estimate the impact on the prevalence of stunted children and other indicators. This stepped wedge design has several advantages for both the implementation and evaluation of services, as well as some disadvantages. The units of delivery are randomized, which controls for other influences on outcomes; the program supports government service delivery systems, so it is replicable and scalable; and the program can be improved over time as lessons are learned. The main disadvantages are the difficulty of estimating the impact of each component of the program, and the geographical distribution of unions, which increases program delivery costs. Stepped implementation allows a cluster randomized trial to be achieved within a large-scale poverty alleviation program and phased-in and scaled-up over a period of time. This paper may encourage evaluators to consider how to estimate attributable impact by using stepped implementation, which allows the counterfactual group eventually to be treated.
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Servicios de Salud Comunitaria , Promoción de la Salud , Trastornos de la Nutrición del Lactante/prevención & control , Adolescente , Adulto , Bangladesh/epidemiología , Enfermedad Crónica , Femenino , Humanos , Lactante , Trastornos de la Nutrición del Lactante/epidemiología , Recién Nacido , Masculino , Persona de Mediana Edad , Embarazo , Evaluación de Programas y Proyectos de Salud , Adulto JovenRESUMEN
Satellite remote sensing offers an effective remedy to challenges in ground-based and aerial mapping that have previously impeded quantitative assessments of global seagrass extent. Commercial satellite platforms offer fine spatial resolution, an important consideration in patchy seagrass ecosystems. Currently, no consistent protocol exists for image processing of commercial data, limiting reproducibility and comparison across space and time. Additionally, the radiometric performance of commercial satellite sensors has not been assessed against the dark and variable targets characteristic of coastal waters. This study compared data products derived from two commercial satellites: DigitalGlobe's WorldView-2 and Planet's RapidEye. A single scene from each platform was obtained at St. Joseph Bay in Florida, USA, corresponding to a November 2010 field campaign. A reproducible processing regime was developed to transform imagery from basic products, as delivered from each company, into analysis-ready data usable for various scientific applications. Satellite-derived surface reflectances were compared against field measurements. WorldView-2 imagery exhibited high disagreement in the coastal blue and blue spectral bands, chronically overpredicting. RapidEye exhibited better agreement than WorldView-2, but overpredicted slightly across all spectral bands. A deep convolutional neural network was used to classify imagery into deep water, land, submerged sand, seagrass, and intertidal classes. Classification results were compared to seagrass maps derived from photointerpreted aerial imagery. This study offers the first radiometric assessment of WorldView-2 and RapidEye over a coastal system, revealing inherent calibration issues in shorter wavelengths of WorldView-2. Both platforms demonstrated as much as 97% agreement with aerial estimates, despite differing resolutions. Thus, calibration issues in WorldView-2 did not appear to interfere with classification accuracy, but could be problematic if estimating biomass. The image processing routine developed here offers a reproducible workflow for WorldView-2 and RapidEye imagery, which was tested in two additional coastal systems. This approach may become platform independent as more sensors become available.
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Chocolate is one of the most popular food types and flavors in the world. Unfortunately, at present, chocolate products contain too much fat, leading to obesity. Although this issue was called into attention decades ago, no actual solution was found. To bypass this critical outstanding problem, two manufacturers introduced some low-calorie fats to substitute for cocoa butter. Somehow, their products are not allowed in most countries. Here we show that this issue is deeply related to the basic science of soft matter, especially to the viscosity of liquid suspension and maximally random jammed (MRJ) density. When the concentration of cocoa solid is high, close to the MRJ density, removing a small amount of fat will jam the chocolate flow. Applying unconventional electrorheology to liquid chocolate with applied field in the flow direction, we aggregate the cocoa particles into prolate spheroids in micrometers. This microstructure change breaks the rotational symmetry, reduces liquid chocolate's viscosity along the flow direction, and increases its MRJ density significantly. Hence the fat level in chocolate can be effectively reduced. We are expecting a new class of healthier and tastier chocolate soon.
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Chocolate , Electricidad , Industria de Procesamiento de Alimentos/métodos , Industria de Procesamiento de Alimentos/instrumentaciónRESUMEN
Oxidative stress results in mtDNA damage and contributes to myocardial cell death. mtDNA repair enzymes are crucial for mtDNA repair and cell survival. We investigated a novel, mitochondria-targeted fusion protein (Exscien1-III) containing endonuclease III in myocardial ischemia-reperfusion injury and transverse aortic constriction (TAC)-induced heart failure. Male C57/BL6J mice (10-12 wk) were subjected to 45 min of myocardial ischemia and either 24 h or 4 wk of reperfusion. Exscien1-III (4 mg/kg ip) or vehicle was administered at the time of reperfusion. Male C57/BL6J mice were subjected to TAC, and Exscien1-III (4 mg/kg i.p) or vehicle was administered daily starting at 3 wk post-TAC and continued for 12 wk. Echocardiography was performed to assess left ventricular (LV) structure and function. Exscien1-III reduced myocardial infarct size ( P < 0.01) at 24 h of reperfusion and preserved LV ejection fraction at 4 wk postmyocardial ischemia. Exscien1-III attenuated TAC-induced LV dilation and dysfunction at 6-12 wk post-TAC ( P < 0.05). Exscien1-III reduced ( P < 0.05) cardiac hypertrophy and maladaptive remodeling after TAC. Assessment of cardiac mitochondria showed that Exscien1-III localized to mitochondria and increased mitochondrial antioxidant and reduced apoptotic markers. In conclusion, our results indicate that administration of Exscien1-III provides significant protection against myocardial ischemia and preserves myocardial structure and LV performance in the setting of heart failure. NEW & NOTEWORTHY Oxidative stress-induced mitochondrial DNA damage is a prominent feature in the pathogenesis of cardiovascular diseases. In the present study, we demonstrate the efficacy of a novel, mitochondria-targeted fusion protein that traffics endonuclease III specifically for mitochondrial DNA repair in two well-characterized murine models of cardiac injury and failure.
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Fármacos Cardiovasculares/farmacología , Daño del ADN/efectos de los fármacos , ADN Mitocondrial/efectos de los fármacos , Insuficiencia Cardíaca/tratamiento farmacológico , Hipertrofia Ventricular Izquierda/tratamiento farmacológico , Disfunción Ventricular Izquierda/tratamiento farmacológico , Función Ventricular Izquierda/efectos de los fármacos , Remodelación Ventricular/efectos de los fármacos , Animales , Apoptosis/efectos de los fármacos , Proteínas Reguladoras de la Apoptosis/metabolismo , ADN Mitocondrial/genética , ADN Mitocondrial/metabolismo , Modelos Animales de Enfermedad , Fibrosis , Insuficiencia Cardíaca/metabolismo , Insuficiencia Cardíaca/patología , Insuficiencia Cardíaca/fisiopatología , Hipertrofia Ventricular Izquierda/metabolismo , Hipertrofia Ventricular Izquierda/patología , Hipertrofia Ventricular Izquierda/fisiopatología , Masculino , Ratones Endogámicos C57BL , Mitocondrias Cardíacas/efectos de los fármacos , Mitocondrias Cardíacas/metabolismo , Mitocondrias Cardíacas/patología , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Estrés Oxidativo/efectos de los fármacos , Proteínas Recombinantes de Fusión/farmacología , Transducción de Señal/efectos de los fármacos , Volumen Sistólico/efectos de los fármacos , Disfunción Ventricular Izquierda/metabolismo , Disfunción Ventricular Izquierda/patología , Disfunción Ventricular Izquierda/fisiopatologíaRESUMEN
Defensins play an important role in plant defense against fungal pathogens. The plant defensin, MtDef4, inhibits growth of the ascomycete fungi, Neurospora crassa and Fusarium graminearum, at micromolar concentrations. We have reported that MtDef4 is transported into the cytoplasm of these fungi and exerts its antifungal activity on intracellular targets. Here, we have investigated whether the antifungal mechanisms of MtDef4 are conserved in these fungi. We show that N. crassa and F. graminearum respond differently to MtDef4 challenge. Membrane permeabilization is required for the antifungal activity of MtDef4 against F. graminearum but not against N. crassa. We find that MtDef4 is targeted to different subcellular compartments in each fungus. Internalization of MtDef4 in N. crassa is energy-dependent and involves endocytosis. By contrast, MtDef4 appears to translocate into F. graminearum autonomously using a partially energy-dependent pathway. MtDef4 has been shown to bind to the phospholipid phosphatidic acid (PA). We provide evidence that the plasma membrane localized phospholipase D, involved in the biosynthesis of PA, is needed for entry of this defensin in N. crassa, but not in F. graminearum. To our knowledge, this is the first example of a defensin which inhibits the growth of two ascomycete fungi via different mechanisms.
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Antifúngicos/metabolismo , Defensinas/metabolismo , Endocitosis/fisiología , Fusarium/crecimiento & desarrollo , Neurospora crassa/crecimiento & desarrollo , Transporte Biológico Activo/efectos de los fármacos , Transporte Biológico Activo/fisiología , Brefeldino A/farmacología , Permeabilidad de la Membrana Celular/fisiología , Endocitosis/efectos de los fármacos , Filipina/farmacología , Ácidos Fosfatidicos/química , Fosfolipasa D/química , Fosfolipasa D/genética , Enfermedades de las Plantas/inmunología , Enfermedades de las Plantas/microbiología , Proteínas de Plantas/metabolismo , Plantas/microbiología , Esporas Fúngicas/efectos de los fármacos , Esporas Fúngicas/crecimiento & desarrolloRESUMEN
Fusarium virguliforme is a soil-borne pathogenic fungus that causes sudden death syndrome (SDS) in soybean. Its pathogenicity is believed to require the activity of cell-wall-degrading enzymes (CWDEs). The sucrose non-fermenting protein kinase 1 gene (SNF1) is a key component of the glucose de-repression pathway in yeast, and a regulator of gene expression for CWDEs in some plant pathogenic fungi. To elucidate the functional role of the SNF1 homolog in F. virguliforme, FvSNF1 was disrupted using a split-marker strategy. Disruption of FvSNF1 in F. virguliforme abolishes galactose utilization and causes poor growth on xylose, arabinose and sucrose. However, the resulting Fvsnf1 mutant grew similar to wild-type and ectopic transformants on glucose, fructose, maltose, or pectin as the main source of carbon. The Fvsnf1 mutant displayed no expression of the gene-encoding galactose oxidase (GAO), a secretory enzyme that catalyzes oxidation of D-galactose. It also exhibited a significant reduction in the expression of several CWDE-coding genes in contrast to the wild-type strain. Greenhouse pathogenicity assays revealed that the Fvsnf1 mutant was severely impaired in its ability to cause SDS on challenged soybean plants. Microscopy and microtome studies on infected roots showed that the Fvsnf1 mutant was defective in colonizing vascular tissue of infected plants. Cross and longitudinal sections of infected roots stained with fluorescein-labeled wheat germ agglutinin and Congo red showed that the Fvsnf1 mutant failed to colonize the xylem vessels and phloem tissue at later stages of infection. Quantification of the fungal biomass in inoculated roots further confirmed a reduced colonization of roots by the Fvsnf1 mutant when compared to the wild type. These findings suggest that FvSNF1 regulates the expression of CWDEs in F. virguliforme, thus affecting the virulence of the fungus on soybean.
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Fusarium/enzimología , Glycine max/microbiología , Enfermedades de las Plantas/genética , Proteínas Serina-Treonina Quinasas/genética , Pared Celular/enzimología , Pared Celular/genética , Fusarium/genética , Fusarium/patogenicidad , Galactosa/metabolismo , Regulación Enzimológica de la Expresión Génica/genética , Raíces de Plantas/enzimología , Raíces de Plantas/genética , Glycine max/genética , Glycine max/fisiología , Sacarosa/metabolismoRESUMEN
The soil-borne fungus Fusarium virguliforme causes sudden death syndrome (SDS), one of the most devastating diseases of soybean in North and South America. Despite the importance of SDS, a clear understanding of the fungal pathogenicity factors that affect the development of this disease is still lacking. We have identified FvSTR1, a F. virguliforme gene, which encodes a protein similar to a family of striatin proteins previously reported to regulate signalling pathways, cell differentiation, conidiation, sexual development, and virulence in filamentous fungi. Striatins are multi-domain proteins that serve as scaffolding units in the striatin-interacting phosphatase and kinase (STRIPAK) complex in fungi and animals. To address the function of a striatin homologue in F. virguliforme, FvSTR1 was disrupted and functionally characterized using a gene knock out strategy. The resulting Fvstr1 mutants were largely impaired in conidiation and pigmentation, and displayed defective conidia and conidiophore morphology compared to the wild-type and ectopic transformants. Greenhouse virulence assays revealed that the disruption of FvSTR1 resulted in complete loss of virulence in F. virguliforme. Microtome studies using fluorescence microscopy showed that the Fvstr1 mutants were defective in their ability to colonize the vascular system. The Fvstr1 mutants also showed a reduced transcript level of genes involved in asexual reproduction and in the production of secondary metabolites. These results suggest that FvSTR1 has a critical role in asexual development and virulence in F. virguliforme.
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Proteínas Fúngicas/genética , Fusarium/crecimiento & desarrollo , Fusarium/patogenicidad , Factores de Virulencia/genética , Proteínas Fúngicas/aislamiento & purificación , Proteínas Fúngicas/fisiología , Fusarium/genética , Fusarium/fisiología , Mutación , Enfermedades de las Plantas/microbiología , Glycine max , Esporas Fúngicas , Virulencia , Factores de Virulencia/fisiologíaRESUMEN
Previous studies have demonstrated that hydrogen sulfide (H2S) protects against multiple cardiovascular disease states in a similar manner as nitric oxide (NO). H2S therapy also has been shown to augment NO bioavailability and signaling. The purpose of this study was to investigate the impact of H2S deficiency on endothelial NO synthase (eNOS) function, NO production, and ischemia/reperfusion (I/R) injury. We found that mice lacking the H2S-producing enzyme cystathionine γ-lyase (CSE) exhibit elevated oxidative stress, dysfunctional eNOS, diminished NO levels, and exacerbated myocardial and hepatic I/R injury. In CSE KO mice, acute H2S therapy restored eNOS function and NO bioavailability and attenuated I/R injury. In addition, we found that H2S therapy fails to protect against I/R in eNOS phosphomutant mice (S1179A). Our results suggest that H2S-mediated cytoprotective signaling in the setting of I/R injury is dependent in large part on eNOS activation and NO generation.
Asunto(s)
Citoprotección/fisiología , Sulfuro de Hidrógeno/metabolismo , Daño por Reperfusión Miocárdica/tratamiento farmacológico , Óxido Nítrico Sintasa de Tipo III/metabolismo , Óxido Nítrico/metabolismo , Transducción de Señal/fisiología , Alanina Transaminasa/sangre , Análisis de Varianza , Animales , Aspartato Aminotransferasas/sangre , Western Blotting , Cromatografía Líquida de Alta Presión , Cistationina gamma-Liasa/genética , Citoprotección/efectos de los fármacos , Sulfuro de Hidrógeno/farmacología , Inmunohistoquímica , Ratones , Ratones Noqueados , Mitocondrias/fisiología , Daño por Reperfusión Miocárdica/metabolismo , Estrés Oxidativo/fisiología , Consumo de Oxígeno/fisiología , Troponina I/metabolismoRESUMEN
Metabolic syndrome (MetS) reduces endothelial nitric oxide (NO) bioavailability and exacerbates vascular dysfunction in patients with preexisting vascular diseases. Nitrite, a storage form of NO, can mediate vascular function during pathological conditions when endogenous NO is reduced. The aims of the present study were to characterize the effects of severe MetS and obesity on dyslipidemia, myocardial oxidative stress, and endothelial NO synthase (eNOS) regulation in the obese Ossabaw swine (OS) model and to examine the effects of a novel, sustained-release formulation of sodium nitrite (SR-nitrite) on coronary vascular reactivity and myocardial redox status in obese OS subjected to critical limb ischemia (CLI). After 6 mo of an atherogenic diet, obese OS displayed a MetS phenotype. Obese OS had decreased eNOS functionality and NO bioavailability. In addition, obese OS exhibited increased oxidative stress and a significant reduction in antioxidant enzymes. The efficacy of SR-nitrite therapy was examined in obese OS subjected to CLI. After 3 wk of treatment, SR-nitrite (80 mg · kg(-1) · day(-1) bid po) increased myocardial nitrite levels and eNOS function. Treatment with SR-nitrite reduced myocardial oxidative stress while increasing myocardial antioxidant capacity. Ex vivo assessment of vascular reactivity of left anterior descending coronary artery segments demonstrated marked improvement in vasoreactivity to sodium nitroprusside but not to substance P and bradykinin in SR-nitrite-treated animals compared with placebo-treated animals. In conclusion, in a clinically relevant, large-animal model of MetS and CLI, treatment with SR-nitrite enhanced myocardial NO bioavailability, attenuated oxidative stress, and improved ex vivo coronary artery vasorelaxation.