Comparative proteomic analysis of growth hormone secretagogue A233 treatment of murine macrophage cells J774A.2 indicates it has a role in antiviral innate response

BackgroundGrowth hormone secretagogues (GHS), among other factors, regulate the release of GH. The biological activity of the secretagogue peptide A233 as a promoter of growth and innate immunity in teleost fish has previously been demonstrated, but its role in the immune system of mammals is not well understood.MethodsThe effect of the peptide was investigated in J774A.2 macrophage cells using a comparative proteomics approach after 6 and 12 h of peptide stimulation.ResultsThe functional analysis of differentially modulated proteins showed that A233 peptide treatment appears to promote activation and ROS-dependent cytotoxic functions in macrophages and enhanced expression of antiviral protein complexes such as MAVS. In accordance with this hypothesis, we found that A233 treatment enhanced superoxide anion production and the IFN-γ level in J774A.2 cells and mouse splenocytes, respectively, and reduced viral load in a dengue virus mouse model of infection.ConclusionsThe growth hormone secretagogue A233 peptide promotes activation of ROS-dependent cytotoxic functions and exerts immunomodulatory effects that enable an antiviral state in a dengue virus mouse model.General SignificanceThe increase of IFN-γ level and the differential modulation of antiviral proteins by the A233 peptide suggest that the molecule could activate an innate immune response with a possible further impact in the treatment of acute and chronic diseases.     

Post‐dispersal seed recovery by animals: is it a plant‐ or an animal‐driven process?

The ability of animals to find and consume hoarded seeds (i.e. seed recovery) is a key stage within the seed dispersal process. However, the ecology of seed recovery is still poorly understood. Here, we analyze the factors controlling seed recovery by scatter‐hoarding rodents in an oak‐dominated temperate forest. We examined the relative importance of intrinsic seed traits (i.e. plant‐driven) and extrinsic seed factors (i.e. animal‐driven) on the probability of seed recovery. We found that seed recovery is mainly driven by extrinsic seed factors, mostly related to animal behavior (pilfering frequency, microsite preference, predation risk, burial depth and cache size). Important intrinsic traits such as seed size, seed quality and seed‐drop timing were, on average, of lower significance in the probability of seed recovery (2.8‐times less important than extrinsic factors); only seed quality was an important intrinsic trait. On the other hand, larger and nutritionally more valuable seeds showed a removal–recovery tradeoff as they enhance seed removal and hoarding (increasing dispersal quality) but also favour seed recovery (increasing predation). We find that other mechanisms beyond seed traits (e.g. masting) are needed to decrease seed recovery and, thus, increase seed survival. We conclude that, as seed recovery is mostly driven by animal behavioural factors, it substantially differs from other previous stages of the seed dispersal process that are more dependent on seed traits. We argue that seed recovery needs further attention to advance our understanding of the ecology of seed dispersal and the role of secondary dispersers as a selective force for seeds.     

Both foliar and residual applications of herbicides that inhibit amino acid biosynthesis induce alternative respiration and aerobic fermentation in pea roots

The objective of this work was to ascertain whether there is a general pattern of carbon allocation and utilisation in plants following herbicide supply, independent of the site of application: sprayed on leaves or supplied to nutrient solution. The herbicides studied were the amino acid biosynthesis‐inhibiting herbicides (ABIH): glyphosate, an inhibitor of aromatic amino acid biosynthesis, and imazamox, an inhibitor of branched‐chain amino acid biosynthesis. All treated plants showed impaired carbon metabolism; carbohydrate accumulation was detected in both leaves and roots of the treated plants. The accumulation in roots was due to lack of use of available sugars as growth was arrested, which elicited soluble carbohydrate accumulation in the leaves due to a decrease in sink strength. Under aerobic conditions, ethanol fermentative metabolism was enhanced in roots of the treated plants. This fermentative response was not related to a change in total respiration rates or cytochrome respiratory capacity, but an increase in alternative oxidase capacity was detected. Pyruvate accumulation was detected after most of the herbicide treatments. These results demonstrate that both ABIH induce the less‐efficient, ATP‐producing pathways, namely fermentation and alternative respiration, by increasing the key metabolite, pyruvate. The plant response was similar not only for the two ABIH but also after foliar or residual application.     

Antioxidant Defenses in Wild Growing Halophyte Crithmum maritimum from Inland and Coastline Populations

Traditional Mediterranean diet includes the halophyte Crithmum maritimum L. (Apiaceae) which can be found in the coastline of the Balearic Islands but also inland. Both areas differed in the environmental conditions, mainly in salinity which can affect the oxidative status of this species. The aim was to evaluate the antioxidant enzyme activities, polyphenols and the lipid peroxidation in leaves of wild C. maritimum growing in a natural coastal area influenced by marine salinity and an inland area without marine influence. The activities of the antioxidant enzymes catalase, superoxide dismutase and glutathione peroxidase as well as polyphenol and reduced glutathione content were significantly higher in the samples from coastline population, whereas no significant differences were found in glutathione reductase activity and in malondialdehyde levels. The production of H₂O₂ was also significantly higher in the population from coastline. In conclusion, C. maritimum adapt their antioxidant defense machinery to the different salinity conditions, avoiding the instauration of oxidative stress.     

Survival and life table parameters of soybean pod borer Maruca vitrata (Geyer) (Lepidoptera: Crambidae) on leguminous crop cultivars

The soybean pod borer, Maruca vitrata is one of the key insect pests of tropical legumes. It damages tender leaf axils, flower buds, flowers and pods by webbing and boring clusters of flowers and pods. In this study, we investigated the survival and life table parameters of M. vitrata on several leguminous crops; soybean (cvs. Daewon, Poongsannamool and Socheongja), azuki bean (cv. Hongeon), mung bean (cv. Sanpo), and cowpea (cv. Jangchae), compared to artificial diet to assess the antibiosis resistance to M. vitrata. The life‐variables of M. vitrata were significantly affected by the tested legume cultivars. None of the larvae fed cowpea cultivar Jangchae survived. The azuki bean cultivar Hongeon and mung bean cultivar Sanpo were found susceptible to M. vitrata, whereas cowpea cultivar Jangchae and soybean cultivar Daewon showed antibiosis resistance to M. vitrata. Further studies should examine the chemicals associated with leguminous crop cultivars and its mechanism to develop a control method against M. vitrata.     

Insecticidal and antifeeding activity of Perilla frutescens‐derived material against the diamondback moth,Plutella xylostella L

Insecticidal and antifeeding activities against Plutella xylostella were observed using whole‐plant‐derived Perilla frutescens material. The active ingredient in P. frutescens was identified by spectroscopic analysis as the sesquiterpenoid α‐farnesene, which showed insecticidal activity against third‐instar larva of P. xylostella in a leaf‐dipping bioassay based on 24‐h LD₅₀ values (LD₅₀ = 53.7 ppm). The feeding inhibition rate of α‐farnesene was 82.98% against P. xylostella at 10 ppm, and the antifeeding responses were determined using an oscilloscope to detect electrophysiological responses. The electrophysiological responses of the medial styloconic sensillum (MSS) were approximately 7‐fold more sensitive at 100 ppm than those of the lateral styloconic sensillum (LSS). These results suggest that the insecticidal and antifeeding effect of α‐farnesene, which is a P. frutescens‐derived material, can be used as a potential control agent for P. xylostella.     

Antileishmanial activity and cytotoxicity of ent-beyerene diterpenoids

We describe the in vitro activity of two natural isomeric ent-beyerene diterpenes, several derivatives and synthetic intermediates. Beyerenols 1 and 2 showed EC₅₀ of 4.6?±?9.4 and 5.3?±?9.4?μg/mL against amastigotes of L. (V) brazilensis, with SI of 5.1 and 7.7, respectively. Beyerenol 1 was synthesized from stevioside. In vivo experiments with bereyenols showed cure in 50% of hamsters infected with L. (V) brazilensis topically applied as Cream I (beyerenol 1, 0.81%, w/w) and Cream III (beyerenol 2, 1.96%, w/w). These results suggest that beyerenols are potential candidates for cutaneous leishmaniasis chemotherapy by topical application. In vitro assays of amastigotes of L. (V) brazilensis showed EC₅₀ of 1.1?±?0.1 and 1.3?±?0.04?μg/mL, with SI of 3.1 and 3.5 for hydrazone intermediates 10 and 11, respectively.     

Light waveguiding in bioinspired peptide nanostructures

Basic optical properties of bioinspired peptide nanostructures are deeply modified by thermally mediated refolding of peptide secondary structure from α‐helical to β‐sheet. This conformational transition is followed by the appearance in the β‐sheet structures of a wideband optical absorption and fluorescence in the visible region. We demonstrate that a new biophotonic effect of optical waveguiding recently observed in peptide/protein nanoensembles is a structure‐sensitive bimodal phenomenon. In the primary α‐helical structure input, light propagates via optical transmission window demonstrating conventional passive waveguiding, based on classical optics. In the β‐sheet structure, fluorescent (active) light waveguiding is revealed. The latter can be attributed to completely different physical mechanism of exciton‐polariton propagation, characterized by high effective refractive index, and can be observed in nanoscale fibers below diffraction limit. It has been shown that peptide material requirements for passive and active waveguiding are dissimilar. Original biocompatibility and biodegradability indicate high potential future applications of these bioinspired waveguiding materials in precise photobiomedicine towards advanced highly selective bioimaging, photon diagnostics, and optogenetics.