Nonspecific Lipid Transfer Protein Research Articles

Crystal structure of nonspecific lipid transfer protein from Solanum melongena.

Lipids are considered to protect protein allergens from proteolysis and are generally seen to exist in a bound form. One of the well-known plant protein families with bound lipids is non-specific lipid transfer proteins (nsLTPs). Structure-function relationships in the case of the members of non-specific lipid transfer protein family are not clearly understood. As part of exploring the seed proteome, we have analyzed the proteome of a member of Solanaceae family, Solanum melongena (eggplant) and a non-specific lipid transfer protein from S. melongena, SM80.2 was purified, crystallized and the structure was determined at 1.87 Å resolution. Overall, the tertiary structure is a cluster of α-helices forming an internal hydrophobic cavity. Absence of conserved Tyr79, known to govern the plasticity of hydrophobic cavity, and formation of hydrogen bond between Asn79 and Asn36 further reduced the pocket size. Structural analysis of SM80.2 thus gives insight about a new hydrogen bond mediated mechanism followed in closure of the binding pocket. Extra electron densities observed at two different places on the protein surface and not in the cavity could provide interesting physiological relevance. In light of allergenic properties, probably overlapping of epitopic region and ligand binding on surface could be a main reason. This work shows first crystal structure of A-like nsLTP with a close binding pocket and extra density on the surface suggesting a plausible intermediate state during transfer.

Proteomic Analysis of Pollen and Blossom Honey from Rape Seed Brassica Napus L.

Abstract In the study, honey from oilseed rape Brassica napus L., and both hand-collected (winter rape Visby and Cult) and bee-collected pollen of oilseed rape were analyzed for their proteome content, in order to see if any plant proteins were present to allow the proteo-typing of the oilseed rape honey. Proteins were fractionated by two-dimensional gel electrophoresis (2DE), stained by Coomassie blue and then analyzed by mass spectrometry. All identified proteins were divided into few groups due to their biological function. In 2DE gels with separated proteins from blossom honey, only bee (Apis mellifera) main proteins (Major royal jelly protein 1-5 and Glucosidase) were found. So we analyzed all proteins using gel-free based analysis with the SYNAPT G2 high definition mass spectrometry. We identified proteins that were present in both oilseed rape pollen and honey (Bna, Polygalacturonase, Non-specific lipid-transfer protein, GAPDH and others). We believe that these proteins are important for the nutritional value of plant pollen-enriched honey and further research is required on honey and honeybee pollen protein.

Isolation and characterization of a non-specific lipid transfer protein from Chelidonium majus L. latex

Plant non-specific lipid transfer proteins (nsLTPs) are small basic proteins, which mostly play a role in intracellular lipid transport and antimicrobial defense. Recently it was shown using shotgun proteomic approach that the whole plant extract of Chelidonium majus L. (Papaveraceae) contains relatively abundant nsLTPs. Therefore the aim of the work was to isolate and characterize nsLTP from C. majus latex. Results obtained using PCR approach with degenerate primers showed the presence of nsLTP protein in C. majus root latex, named CmLTP 9.5. The protein consists of 93 aa with a molecular weight of 9.5kDa (NCBI GenBank accession no. ALT21495, coded by KP733898). The mature form of CmLTP 9.5 has a molecular weight of 7.147kDa and contains typical eight strictly conserved cysteine residues. A 3D model of CmLTP 9.5 displays a hydrophobic cavity. The isolated protein fraction tested using diffusion method and critical dilution assay showed strong antibacterial activity towards Gram-negative Campylobacter jejuni as well as Gram-positive Listeria greyi and Clostridium perfringens. Further studies using protein expression system are required to fully understand CmLTP 9.5 mode of action.

Identification of the active protein in rice bran protein having an inhibitory activity of cholesterol micellar solubility.

In our previous study, rice bran protein (RBP) inhibited cholesterol micellar solubility in vitro and decreased serum cholesterol level in rats. In the present study, RBP was separated and purified by size-exclusion chromatography and reversed-phase chromatography. The active protein of RBP related to cholesterol micellar solubility was identified as lectin and non-specific lipid-transfer protein 1 using MALDI-TOF mass spectrometry analysis.

Molecular insights into the functional role of nitric oxide (NO) as a signal for plant responses in chickpea.

The molecular mechanisms and targets of nitric oxide (NO) are not fully known in plants. Our study reports the first large-scale quantitative proteomic analysis of NO donor responsive proteins in chickpea. Dose response studies carried out using NO donors, sodium nitroprusside (SNP), diethylamine NONOate (DETA) and S-nitrosoglutathione (GSNO) in chickpea genotype ICCV1882, revealed a dose dependent positive impact on seed germination and seedling growth. SNP at 0.1mM concentration proved to be most appropriate following confirmation using four different chickpea genotypes. while SNP treatment enhanced the percentage of germination, chlorophyll and nitrogen contents in chickpea, addition of NO scavenger, cPTIO reverted its impact under abiotic stresses. Proteome profiling revealed 172 downregulated and 76 upregulated proteins, of which majority were involved in metabolic processes (118) by virtue of their catalytic (145) and binding (106) activity. A few crucial proteins such as S-adenosylmethionine synthase, dehydroascorbate reductase, pyruvate kinase fragment, 1-aminocyclopropane-1-carboxylic acid oxidase, 1-pyrroline-5-carboxylate synthetase were less abundant whereas Bowman-Birk type protease inhibitor, non-specific lipid transfer protein, chalcone synthase, ribulose-1-5-bisphosphate carboxylase oxygenase large subunit, PSII D2 protein were highly abundant in SNP treated samples. This study highlights the protein networks for a better understanding of possible NO induced regulatory mechanisms in plants.

How α-Helical Motifs Form Functionally Diverse Lipid-Binding Compartments.

Lipids are produced site-specifically in cells and then distributed nonrandomly among membranes via vesicular and nonvesicular trafficking mechanisms. The latter involves soluble amphitropic proteins extracting specific lipids from source membranes to function as molecular solubilizers that envelope their insoluble cargo before transporting it to destination sites. Lipid-binding and lipid transfer structural motifs range from multi-β-strand barrels, to β-sheet cups and baskets covered by α-helical lids, to multi-α-helical bundles and layers. Here, we focus on how α-helical proteins use amphipathic helical layering and bundling to form modular lipid-binding compartments and discuss the functional consequences. Preformed compartments generally rely on intramolecular disulfide bridging to maintain conformation (e.g., albumins, nonspecific lipid transfer proteins, saposins, nematode polyprotein allergens/antigens). Insights into nonpreformed hydrophobic compartments that expand and adapt to accommodate a lipid occupant are few and provided mostly by the three-layer, α-helical ligand-binding domain of nuclear receptors. The simple but elegant and nearly ubiquitous two-layer, α-helical glycolipid transfer protein (GLTP)-fold now further advances understanding.

The Arabidopsis Lipid Transfer Protein 2 (AtLTP2) Is Involved in Cuticle-Cell Wall Interface Integrity and in Etiolated Hypocotyl Permeability.

Plant non-specific lipid transfer proteins (nsLTPs) belong to a complex multigenic family implicated in diverse physiological processes. However, their function and mode of action remain unclear probably because of functional redundancy. Among the different roles proposed for nsLTPs, it has long been suggested that they could transport cuticular precursor across the cell wall during the formation of the cuticle, which constitutes the first physical barrier for plant interactions with their aerial environment. Here, we took advantage of the Arabidopsis thaliana etiolated hypocotyl model in which AtLTP2 was previously identified as the unique and abundant nsLTP member in the cell wall proteome, to investigate its function. AtLTP2 expression was restricted to epidermal cells of aerial organs, in agreement with the place of cuticle deposition. Furthermore, transient AtLTP2-TagRFP over-expression in Nicotiana benthamiana leaf epidermal cells resulted in its localization to the cell wall, as expected, but surprisingly also to the plastids, indicating an original dual trafficking for a nsLTP. Remarkably, in etiolated hypocotyls, the atltp2-1 mutant displayed modifications in cuticle permeability together with a disorganized ultra-structure at the cuticle-cell wall interface completely recovered in complemented lines, whereas only slight differences in cuticular composition were observed. Thus, AtLTP2 may not play the historical purported nsLTP shuttling role across the cell wall, but we rather hypothesize that AtLTP2 could play a major structural role by maintaining the integrity of the adhesion between the mainly hydrophobic cuticle and the hydrophilic underlying cell wall. Altogether, these results gave new insights into nsLTP functions.

Genomic Identification and Comparative Expansion Analysis of the Non-Specific Lipid Transfer Protein Gene Family in Gossypium.

Plant non-specific lipid transfer proteins (nsLTPs) are involved in many biological processes. In this study, 51, 47 and 91 nsLTPs were identified in Gossypium arboreum, G. raimondii and their descendant allotetraploid G. hirsutum, respectively. All the nsLTPs were phylogenetically divided into 8 distinct subfamilies. Besides, the recent duplication, which is considered cotton-specific whole genome duplication, may have led to nsLTP expansion in Gossypium. Both tandem and segmental duplication contributed to nsLTP expansion in G. arboreum and G. hirsutum, while tandem duplication was the dominant pattern in G. raimondii. Additionally, the interspecific orthologous gene pairs in Gossypium were identified. Some GaLTPs and GrLTPs lost their orthologs in the At and Dt subgenomes, respectively, of G. hirsutum. The distribution of these GrLTPs and GaLTPs within each subfamily was complementary, suggesting that the loss and retention of nsLTPs in G. hirsutum might not be random. Moreover, the nsLTPs in the At and Dt subgenomes might have evolved symmetrically. Furthermore, both intraspecific and interspecific orthologous genes showed considerable expression variation, suggesting that their functions were strongly differentiated. Our results lay an important foundation for expansion and evolutionary analysis of the nsLTP family in Gossypium, and advance nsLTP studies in other plants, especially polyploid plants.

A Non-specific Setaria italica Lipid Transfer Protein Gene Plays a Critical Role under Abiotic Stress.

Lipid transfer proteins (LTPs) are a class of cysteine-rich soluble proteins having small molecular weights. LTPs participate in flower and seed development, cuticular wax deposition, also play important roles in pathogen and abiotic stress responses. A non-specific LTP gene (SiLTP) was isolated from a foxtail millet (Setaria italica) suppression subtractive hybridization library enriched for differentially expressed genes after abiotic stress treatments. A semi-quantitative reverse transcriptase PCR analysis showed that SiLTP was expressed in all foxtail millet tissues. Additionally, the SiLTP promoter drove GUS expression in root tips, stems, leaves, flowers, and siliques of transgenic Arabidopsis. Quantitative real-time PCR indicated that the SiLTP expression was induced by NaCl, polyethylene glycol, and abscisic acid (ABA). SiLTP was localized in the cytoplasm of tobacco leaf epidermal cells and maize protoplasts. The ectopic expression of SiLTP in tobacco resulted in higher levels of salt and drought tolerance than in the wild type (WT). To further assess the function of SiLTP, SiLTP overexpression (OE) and RNA interference (RNAi)-based transgenic foxtail millet were obtained. SiLTP-OE lines performed better under salt and drought stresses compared with WT plants. In contrast, the RNAi lines were much more sensitive to salt and drought compared than WT. Electrophoretic mobility shift assays and yeast one-hybrids indicated that the transcription factor ABA-responsive DRE-binding protein (SiARDP) could bind to the dehydration-responsive element of SiLTP promoter in vitro and in vivo, respectively. Moreover, the SiLTP expression levels were higher in SiARDP-OE plants compared than the WT. These results confirmed that SiLTP plays important roles in improving salt and drought stress tolerance of foxtail millet, and may partly be upregulated by SiARDP. SiLTP may provide an effective genetic resource for molecular breeding in crops to enhance salt and drought tolerance levels.

The Nonspecific Lipid Transfer Protein AtLtpI-4 Is Involved in Suberin Formation of Arabidopsis thaliana Crown Galls.

Nonspecific lipid transfer proteins reversibly bind different types of lipid molecules in a hydrophobic cavity. They facilitate phospholipid transfer between membranes in vitro, play a role in cuticle and possibly in suberin formation, and might be involved in plant pathogen defense signaling. This study focuses on the role of the lipid transfer protein AtLTPI-4 in crown gall development. Arabidopsis (Arabidopsis thaliana) crown gall tumors, which develop upon infection with the virulent Agrobacterium tumefaciens strain C58, highly expressed AtLTPI-4 Crown galls of the atltpI-4 loss-of-function mutant were much smaller compared with those of wild-type plants. The gene expression pattern and localization of the protein to the plasma membrane pointed to a function of AtLTPI-4 in cell wall suberization. Since Arabidopsis crown galls are covered by a suberin-containing periderm instead of a cuticle, we analyzed the suberin composition of crown galls and found a reduction in the amounts of long-chain fatty acids (C18:0) in the atltpI-4 mutant. To demonstrate the impact of AtLtpI-4 on extracellular lipid composition, we expressed the protein in Arabidopsis epidermis cells. This led to a significant increase in the very-long-chain fatty acids C24 and C26 in the cuticular wax fraction. Homology modeling and lipid-protein-overlay assays showed that AtLtpI-4 protein can bind these very-long-chain fatty acids. Thus, AtLtpI-4 protein may facilitate the transfer of long-chain as well as very-long-chain fatty acids into the apoplast, depending on the cell type in which it is expressed. In crown galls, which endogenously express AtLtpI-4, it is involved in suberin formation.

Cannabis sativaallergy: looking through the fog

IgE-mediated Cannabis (C. sativa, marihuana) allergy seems to be on the rise. Both active and passive exposure to cannabis allergens may trigger a C. sativa sensitization and/or allergy. The clinical presentation of a C. sativa allergy varies from mild to life-threatening reactions and often seems to depend on the route of exposure. In addition, sensitization to cannabis allergens can result in various cross-allergies, mostly for plant foods. This clinical entity, designated as the 'cannabis-fruit/vegetable syndrome', might also imply cross-reactivity with tobacco, natural latex and plant-food-derived alcoholic beverages. Hitherto, these cross-allergies are predominantly reported in Europe and appear mainly to rely upon cross-reactivity between nonspecific lipid transfer proteins or thaumatin-like proteins present in C. sativa and their homologues, ubiquitously distributed throughout plant kingdom. At present, diagnosis of cannabis-related allergies predominantly rests upon a thorough history completed with skin testing using native extracts from crushed buds and leaves. However, quantification of specific IgE antibodies and basophil activation tests can also be helpful to establish correct diagnosis. In the absence of a cure, treatment comprises absolute avoidance measures. Whether avoidance of further use will halt the extension of related cross-allergies remains uncertain.

Quantitative Proteomic Analysis of Wheat Seeds during Artificial Ageing and Priming Using the Isobaric Tandem Mass Tag Labeling.

Wheat (Triticum aestivum L.) is an important crop worldwide. The physiological deterioration of seeds during storage and seed priming is closely associated with germination, and thus contributes to plant growth and subsequent grain yields. In this study, wheat seeds during different stages of artificial ageing (45°C; 50% relative humidity; 98%, 50%, 20%, and 1% Germination rates) and priming (hydro-priming treatment) were subjected to proteomics analysis through a proteomic approach based on the isobaric tandem mass tag labeling. A total of 162 differentially expressed proteins (DEPs) mainly involved in metabolism, energy supply, and defense/stress responses, were identified during artificial ageing and thus validated previous physiological and biochemical studies. These DEPs indicated that the inability to protect against ageing leads to the incremental decomposition of the stored substance, impairment of metabolism and energy supply, and ultimately resulted in seed deterioration. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that the up-regulated proteins involved in seed ageing were mainly enriched in ribosome, whereas the down-regulated proteins were mainly accumulated in energy supply (starch and sucrose metabolism) and stress defense (ascorbate and aldarate metabolism). Proteins, including hemoglobin 1, oleosin, agglutinin, and non-specific lipid-transfer proteins, were first identified in aged seeds and might be regarded as new markers of seed deterioration. Of the identified proteins, 531 DEPs were recognized during seed priming compared with unprimed seeds. In contrast to the up-regulated DEPs in seed ageing, several up-regulated DEPs in priming were involved in energy supply (tricarboxylic acid cycle, glycolysis, and fatty acid oxidation), anabolism (amino acids, and fatty acid synthesis), and cell growth/division. KEGG and protein-protein interaction analysis indicated that the up-regulated proteins in seed priming were mainly enriched in amino acid synthesis, stress defense (plant-pathogen interactions, and ascorbate and aldarate metabolism), and energy supply (oxidative phosphorylation and carbon metabolism). Therefore, DEPs associated with seed ageing and priming can be used to characterize seed vigor and optimize germination enhancement treatments. This work reveals new proteomic insights into protein changes that occur during seed deterioration and priming.

Lipid transfer proteins: classification, nomenclature, structure, and function.

The non-specific lipid transfer proteins (LTPs) constitute a large protein family found in all land plants. They are small proteins characterized by a tunnel-like hydrophobic cavity, which makes them suitable for binding and transporting various lipids. The LTPs are abundantly expressed in most tissues. In general, they are synthesized with an N-terminal signal peptide that localizes the protein to spaces exterior to the plasma membrane. The in vivo functions of LTPs are still disputed, although evidence has accumulated for a role in the synthesis of lipid barrier polymers, such as cuticular waxes, suberin, and sporopollenin. There are also reports suggesting that LTPs are involved in signaling during pathogen attacks. LTPs are considered as key proteins for the plant’s survival and colonization of land. In this review, we aim to present an overview of the current status of LTP research and also to discuss potential future applications of these proteins. We update the knowledge on 3D structures and lipid binding and review the most recent data from functional investigations, such as from knockout or overexpressing experiments. We also propose and argument for a novel system for the classification and naming of the LTPs.

How relevant is panallergen sensitization in the development of allergies?

Panallergens comprise various protein families of plant as well as animal origin and are responsible for wide IgE cross‐reactivity between related and unrelated allergenic sources. Such cross‐reactivities include reactions between various pollen sources, pollen and plant‐derived foods as well as invertebrate‐derived inhalants and foodstuff. Here, we provide an overview on the most clinically relevant panallergens from plants (profilins, polcalcins, non‐specific lipid transfer proteins, pathogenesis‐related protein family 10 members) and on the prominent animal‐derived panallergen family, tropomyosins. In addition, we explore the role of panallergens in the sensitization process and progress of the allergic disease. Emphasis is given on epidemiological aspects of panallergen sensitization and clinical manifestations. Finally, the issues related to diagnosis and therapy of patients sensitized to panallergens are outlined, and the use of panallergens as predictors for cross‐reactive allergy and as biomarkers for disease severity is discussed.

IgE-reactivity profiles to nonspecific lipid transfer proteins in a northwestern European country

IgE-reactivity profiles to nonspecific lipid transfer proteins in a northwestern European country

Ligand binding to an Allergenic Lipid Transfer Protein Enhances Conformational Flexibility resulting in an Increase in Susceptibility to Gastroduodenal Proteolysis.

Non-specific lipid transfer proteins (LTPs) are a family of lipid-binding molecules that are widely distributed across flowering plant species, many of which have been identified as allergens. They are highly resistant to simulated gastroduodenal proteolysis, a property that may play a role in determining their allergenicity and it has been suggested that lipid binding may further increase stability to proteolysis. It is demonstrated that LTPs from wheat and peach bind a range of lipids in a variety of conditions, including those found in the gastroduodenal tract. Both LTPs are initially cleaved during gastroduodenal proteolysis at three major sites between residues 39–40, 56–57 and 79–80, with wheat LTP being more resistant to cleavage than its peach ortholog. The susceptibility of wheat LTP to proteolyic cleavage increases significantly upon lipid binding. This enhanced digestibility is likely to be due to the displacement of Tyr79 and surrounding residues from the internal hydrophobic cavity upon ligand binding to the solvent exposed exterior of the LTP, facilitating proteolysis. Such knowledge contributes to our understanding as to how resistance to digestion can be used in allergenicity risk assessment of novel food proteins, including GMOs.

Component-Resolved Diagnosis of Peanut Allergy and Its Possible Origins of Sensitization in China

Background: Clinical and immunological characteristics of food allergies vary depending on geographic regions. Little is known about peanut allergy in China. The aim of this study was to investigate the peanut sensitization profile in China. Methods: Thirty-eight participants with immunoglobulin E (IgE)-positive responses to peanuts (peanut-sensitized) were included in our study, and clinical characteristics were evaluated. Total and specific IgE reactivity against peanuts, other plant-derived foods, pollens, and related allergen components were determined. Results: Eighteen patients were symptomatic when exposed to peanuts. The majority of them presented with systemic reactions. More than half of the peanut-sensitized subjects also suffered from mugwort pollinosis and peach allergy. In patients with both peanut and peach allergies, reactions to peanuts were the same as or severer than those to peaches. Positivity rates of IgE response to rAra h 1-3, 8, and 9 in the peanut allergy group were 5.6, 11.1, 5.6, 22.2, and 83.3%, respectively. 66.7% (12/18) of the peanut-allergic patients were monosensitized to rAra h 9. Anti-nArt v 3 [mugwort nonspecific lipid transfer protein (nsLTP)] IgE positivity in the peanut allergy group was significantly higher than that in the asymptomatic peanut-sensitized group. In Ara h 9 (peanut nsLTP)-sensitized patients with mugwort pollinosis, anti-nArt v 3 IgE levels were remarkably higher than anti-rAra h 9 (peanut nsLTP) IgE levels as well as anti-Pru p 3 (peach nsLTP) IgE levels. Conclusions: Ara h 9 was the major allergen of peanut, and Ara h 9 monosensitization was the most common peanut sensitization pattern in our population. Furthermore, there was a strong correlation between peanut sensitization and mugwort pollinosis, as well as peach allergy, in our country.

Molecular cloning of plane pollen allergen Plaa3 and its utility as diagnostic marker for peach associated plane pollen allergy.

Non-specific lipid transfer proteins (nsLTP) are considered to provoke allergic symptoms to plane tree pollen, which are frequently associated with peach allergy. The objective was to clone the cDNA of plane pollen nsLTP Plaa3, to characterize IgE-binding and allergenic potency of recombinant Plaa3 in comparison to its natural counterpart and peach nsLTP Prup3. Natural Plaa3 was purified from plane pollen and analysed by mass spectrometry (MS). Recombinant Plaa3 was characterized by SDS-PAGE and CD spectroscopy. Specific IgE to extract, components of plane pollen and Prup3 was measured by ImmunoCAP in sera of patients allergic to either plane pollen (n=10), peach (n=15) or both (n=15). Biological potency of the proteins was investigated by invitro mediator release assays and IgE cross-reactivity by competitive ELISA. Two Plaa3 isoforms were identified. Recombinant Plaa3 showed high purity, structural integrity, IgE-binding capacity comparable to nPlaa3 and biological potency. Sensitization to plane pollen extract was confirmed in 24/25 plane pollen allergics. The frequency of sensitization to Plaa3 was 53% among patients allergic to both plane pollen and peach and 10% among plane pollen allergics tolerating peach where most patients were sensitized to Plaa1. Plaa3 and Prup3 showed strong bi-directional IgE cross-reactivity in patients allergic to peach and plane pollen, but not in peach allergics tolerating plane pollen. Levels of IgE-binding were generally higher to Prup3 than to Plaa3. Sensitization to Plaa3 is relevant in a subgroup of plane pollen allergics with concomitant peach allergy. IgE testing with Plaa3 may serve as a marker to identify plane pollen allergic patients at risk of LTP-mediated food reactions and thereby improve invitro diagnostic procedures.

The era of allergy.

It is very true that we are living in 'the Era of Allergy'. Era of Allergy: Local and Global Insights and Intervention is the main theme of the Joint Congress of Asia Pacific Association of Allergy, Asthma, and Clinical Immunology (APAAACI) and Asia Pacific Association of Pediatric Allergy, Respiratory, and Immunology (APAPARI) in Kuala Lumpur, Malaysia during 17th–20th October, 2016 (http://www.apaaaci-kl2016.org). We believe that you can enjoy the state-of-art clinical knowledge and science on allergy, friendship, and the culture of Malaysia during the Joint Congress. Please save the date (early registration until 30th June, 2016)! Drug allergy is increasing as the use of medications increases [1]. What does make drugs recognized as allergens? Yun et al. [2] describe a very nice review article on T-cell-mediated drug hypersensitivity starting from the classical hapten/pro-hapten theory and the danger hypothesis to the pharmacological interaction with immune receptors (p-i) concept and the altered peptide repertoire hypothesis. Readers will also enjoy the current data and the possible mechanisms on the association of HLA alleles and drug hypersensitivity reactions. In this issue of Asia Pacific Allergy, readers will find an article from central China on the knowledge, attitudes, and practices of drug allergy among healthcare practitioners [3]. The authors describe the data from the questionnaire survey and conclude that the education is urgently needed to fill the gap between the current knowledge and the real clinical practice on drug allergy. Allergic rhinitis could be the most common allergic disease of which trends can be traced with Google trends search [4]. Readers will find an article from the Philippines on the Attitudes, practices on allergic rhinitis of three socioeconomic classes of Filipinos in the National Capital Region [5]. Lei et al. [6] described that obesity was a risk factor for allergic rhinitis in children of Wuhan, China. Readers also find a letter from Finland that need for medication and stuffy nose predicted the severity of allergic rhinitis from the comparison of the severity of symptoms using the numeric rating score and the Rhinasthma questionnaire [7]. Asthma can also affect all ages although its prevalence is especially high in childhood and in the elderly [8]. Asthma is important for its prevalence but also for the socioeconomic burden especially according to the severit y and the exacerbations [9,10]. Bathing is an important life style. Some of our patients complain of the exacerbations of asthma symptoms while others say that they feel comfortable when they are taking a bath. Could the humidity and temperature affect the symptoms of asthma while taking a bath? Very interestingly, K amimura et al. [11] conducted an observational study to investigate changes in symptoms and their degree by bathing in asthmatic patients. Atopic dermatitis itself is important for its prevalence and the burden of disease but also important as the initial manifestations of allergic diseases in many patients. Environmental exposure to peanut, such as in house dust, especially with an impaired skin barrier attributed to atopic dermatitis and loss of function mutations in the filaggrin gene, could be a risk factor for sensitization and allergy [12]. In this issue, readers will find a review article on the role of moisturizers for atopic dermatitis with some consensus in our region [13]. Food allergy has been referred to as the second wave of the allergy epidemic and has been an important allergic disease with common food allergens but also some unique food allergens in our region [14]. Murad et al. [15] report a case study of apple seed and grape allergy with sensitisation to non-specific lipid transfer protein from Australia. When you see the patients of allergic diseases, it is very important to take a history on occupation. Asia is a populous and diverse region with various kinds of occupations. In this issue, readers will find a comparative study on the sensitization to silk allergen among workers of silk filatures in India [16].

ITRAQ-based proteomic analysis reveals the mechanisms of silicon-mediated cadmium tolerance in rice (Oryza sativa) cells

Silicon (Si) can alleviate cadmium (Cd) stress in rice (Oryza sativa) plants, however, the understanding of the molecular mechanisms at the single-cell level remains limited. To address these questions, we investigated suspension cells of rice cultured in the dark environment in the absence and presence of Si with either short- (12 h) or long-term (5 d) Cd treatments using a combination of isobaric tags for relative and absolute quantitation (iTRAQ), fluorescent staining, and inductively coupled plasma mass spectroscopy (ICP-MS). We identified 100 proteins differentially regulated by Si under the short- or long-term Cd stress. 70% of these proteins were down-regulated, suggesting that Si may improve protein use efficiency by maintaining cells in the normal physiological status. Furthermore, we showed two different mechanisms for Si-mediated Cd tolerance. Under the short-term Cd stress, the Si-modified cell walls inhibited the uptake of Cd ions into cells and consequently reduced the expressions of glycosidase, cell surface non-specific lipid-transfer proteins (nsLTPs), and several stress-related proteins. Under the long-term Cd stress, the amount of Cd in the cytoplasm in Si-accumulating (+Si) cells was decreased by compartmentation of Cd into vacuoles, thus leading to a lower expression of glutathione S-transferases (GST). These results provide protein-level insights into the Si-mediated Cd detoxification in rice single cells.