Species-dependent Manner Research Articles

Development and characterization of recombinant ADP-ribose binding reagents that allow simultaneous detection of mono and poly ADP-ribose

ADP-ribosylation (ADPRylation) is a post-translational modification (PTM) of proteins mediated by the activity of a variety of ADP-ribosyltransferase (ART) enzymes, such as the Poly (ADP-ribose) Polymerase (PARP) family of proteins. This PTM is diverse in both form and biological functions, which makes it a highly interesting modification, but difficult to study due to limitations in reagents available to detect the diversity of ADPRylation. Recently we developed a set of recombinant antibody-like ADP-ribose (ADPR) binding proteins using naturally occurring ADPR binding domains (ARBDs), including macrodomains and WWE domains, functionalized by fusion to the constant "Fc" region of rabbit immunoglobulin. Herein, we present an expansion of this biological toolkit, where we have replaced the rabbit Fc sequence with the sequence from two other species, mouse and goat. These new reagents are based on a previously characterized set of naturally occurring ARBDs with known specificity. Characterization of the new reagents demonstrates that they can be detected in a species-dependent manner by secondary immunological tools, recognize specific ADPR moieties, and can be used for simultaneous detection of mono ADPR and poly ADPR at single-cell resolution in various antibody-based assays. The expansion of this toolkit will allow for more multiplexed assessments of the complexity of ADPRylation biology in many biological systems.

Bacterial biofilm formation on headpieces of Cochlear implants.

Bacterial biofilm formation on medical devices, such as Cochlear implants (CI), can lead to chronic infections. Not only the inner parts of the implant but also the externally located headpiece might be associated with prolonged superficial skin eczema resulting in the inability of wearing the headpiece. In this study, the surface of three CI headpieces from different manufacturers were examined for bacterial biofilm formation. Two bacterial species associated with implant-related infections were tested: Pseudomonas aeruginosa (ATCC9027) and Staphylococcus aureus (ATCC6538). Biofilms were formed over 24h in tryptic soy broth at 36°C. Biofilm formation was detected in form of biomass measurement by crystal violet staining. CI headpiece dummies of three manufacturers were used. Both tested bacterial species formed biofilms on the examined CI headpiece-surfaces in a species-dependent manner with higher biofilm formation of P. aeruginosa. For both, S. aureus and P. aeruginosa, biofilm formation on the CI components was comparable to a polystyrene control surface. Between the three manufacturers, no significant difference in biofilm formation was found. The tested bacteria displayed biofilm formation on the CI headpieces in a species-specific manner with higher amount of biofilm formed by P. aeruginosa. The biofilm formation was comparable between the manufacturers. In this study, an enhanced biofilm formation on CI headpieces could not be demonstrated. These in vitro tests suggest a minor role of bacterial biofilm on the CI headpiece in skin infections under the CI headpiece.

Quaternary ammonium biocides promote conjugative transfer of antibiotic resistance gene in structure- and species-dependent manner

The linkage between biocides and antibiotic resistance has been widely suggested in laboratories and various environments. However, the action mechanism of biocides on antibiotic resistance genes (ARGs) spread is still unclear. Thus, 6 quaternary ammonium biocides (QACs) with different bonded substituents or alkyl chain lengths were selected to assess their effects on the conjugation transfer of ARGs in this study. Two conjugation models with the same donor (E. coli DH5α (RP4)) into two receptors, E. coli MG1655 and pathogenic S. sonnei SE6-1, were constructed. All QACs were found to significantly promote intra- and inter-genus conjugative transfer of ARGs, and the frequency was highly impacted by their structure and receptors. At the same environmental exposure level (4 × 10-1 mg/L), didecyl dimethyl ammonium chloride (DDAC (C10)) promoted the most frequency of conjugative transfer, while benzathine chloride (BEC) promoted the least. With the same donor, the enhanced frequency of QACs of intra-transfer is higher than inter-transfer. Then, the acquisition mechanisms of two receptors were further determined using biochemical combined with transcriptome analysis. For the recipient E. coli, the promotion of the intragenus conjugative transfer may be associated with increased cell membrane permeability, reactive oxygen species (ROS) production and proton motive force (PMF)-induced enhancement of flagellar motility. Whereas, the increase of cell membrane permeability and decreased flagellar motility due to PMF disruption but encouraged biofilm formation, maybe the main reasons for promoting intergenus conjugative transfer in the recipient S. sonnei. As one pathogenic bacterium, S. sonnei was first found to acquire ARGs by biocide exposure.

STING1-accelerated vascular smooth muscle cell senescence-associated vascular calcification in diabetes is ameliorated by oleoylethanolamide via improved mitochondrial DNA oxidative damage

Vascular calcification is a prevalent hallmark of cardiovascular risk in elderly and diabetic individuals. Senescent vascular smooth muscle cells (VSMCs) participate in calcification; however, the associated underlying mechanisms remain unknown. Aberrant activation of the cytosolic DNA sensing adaptor stimulator of interferon gene 1 (STING1) caused by cytosolic DNA, particularly that leaked from damaged mitochondria, is a catalyst for aging-related diseases. Although oleoylethanolamide (OEA) is an endogenous bioactive lipid mediator with lipid overload-associated vasoprotective effects, its benefit in diabetic vascular calcification remains uncharacterized. This study focused on the role of STING1 in mitochondrial dysfunction-mediated calcification and premature VMSC senescence in diabetes and the effects of OEA on these pathological processes. In diabetic in vivo rat/mouse aorta calcification models and an in vitro VSMC calcification model induced by Nε-carboxymethyl-lysine (CML), senescence levels, STING1 signaling activation, and mitochondrial damage markers were significantly augmented; however, these alterations were markedly alleviated by OEA, partially in a nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent manner, and similar anti-calcification and senescence effects were observed in STING1-knockout mice and STING1-knockdown VSMCs. Mechanistically, mitochondrial DNA (mtDNA) damage was aggravated by CML in a reactive oxygen species-dependent manner, followed by mtDNA leakage into the cytosol, contributing to VSMC senescence-associated calcification via STING1 pathway activation. OEA treatment significantly attenuated the aforementioned cytotoxic effects of CML by enhancing cellular antioxidant capacity through the maintenance of Nrf2 translocation to the nucleus. Collectively, targeting STING1, a newly defined VSMC senescence regulator, contributes to anti-vascular calcification effects.

Synergistic cytotoxicity effect of ultrasound and plasma microbubble in glioblastoma 3D tumor sphere model

AbstractThe combined application of ultrasound (US) and plasma microbubble (PMB) is a promising technology against glioblastoma (GBM). Here, we determined the effects of US and PMB (alone and combined) on U‐251 MG GBM and A431 epidermoid carcinoma spheroids under different conditions. The synergistic treatment of US‐ and PMB‐induced tumor sphere cell death in a time‐, dose‐, treatment frequency‐, and reactive oxygen species dependent manner, while multiple treatments augmented this effect. Synergistic treatments significantly reduced three‐dimensional GBM spheroid regrowth and cell proliferation while inducing cytotoxicity, spheroid shrinkage, and damage to the tumor microenvironment. PMB‐induced cytotoxicity throughout the tumor sphere, likely via long‐lived reactive oxygen and nitrogen species (H2O2, NO2−, and NO3−) and other reactive species.

Discovery of a Novel Dual Targeting Peptide for Human Glioma: From In Silico Simulation to Acting as Targeting Ligand.

Receptor-mediated transcytosis (RMT) is a more specific, highly efficient, and reliable approach to crossing the blood-brain-barrier (BBB) and releasing the therapeutic cargos into the brain parenchyma. Here, we introduced and characterized a human/mouse-specific novel leptin-derived peptide using in silico, in vitro and in vivo experiments. Based on the bioinformatics analysis and molecular dynamics (MD) simulation, a 14 amino acid peptide sequence (LDP 14) was introduced and its interaction with leptin-receptor (ObR) was analyzed in comparison with an well known leptin-derived peptide, Lep 30. MD simulation data revealed a significant stable interaction between ligand binding domains (LBD) of ObR with LDP 14. Analyses demonstrated suitable cellular uptake of LDP 14 alone and its derivatives (LDP 14-modified G4 PAMAM dendrimer and LDP 14-modified G4 PAMAM/pEGFP-N1 plasmid complexes) via ObR, energy and species dependent manner (preferred uptake by human/mouse cell lines compared to rat cell line). Importantly, our findings illustrated that the entry of LDP 14-modified dendrimers in hBCEC-D3 cells not only is not affected by protein corona (PC) formation, as the main reason for diminishing the cellular uptake, but also PC per se can enhance uptake rate. Finally, fluorescein labeled LDP 14-modified G4 PAMAM dendrimers efficiently accumulated in the mice brain with lower biodistribution in other organs, in our in vivo study. LDP 14 introduced as a novel and highly efficient ligand, which can be used for drugs/genes delivery to brain tissue in different central nervous system (CNS) disorders.

Responses of peritubular macrophages and the testis transcriptome profiles of peripubertal and adult rodents exposed to an acute dose of MEHP.

Exposure of rodents to mono-(2-ethylhexyl) phthalate (MEHP) is known to disrupt the blood-testis barrier and cause testicular germ cell apoptosis. Peritubular macrophages (PTMφ) are a newly identified type of testicular macrophage that aggregates near the spermatogonial stem cell niche. We have previously reported that MEHP exposure increased the numbers of PTMφs by 6-fold within the testis of peripubertal rats. The underlying mechanism(s) accounting for this change in PTMφs and its biological significance is unknown. This study investigates if MEHP-induced alterations in PTMφs occur in rodents (PND 75 adult rats and PND 26 peripubertal mice) that are known to be less sensitive to MEHP-induced testicular toxicity. Results show that adult rats have a 2-fold higher basal level of PTMφ numbers than species-matched peripubertal animals, but there was no significant increase in PTMφ numbers after MEHP exposure. Peripubertal mice have a 5-fold higher basal level of PTMφ compared with peripubertal rats but did not exhibit increases in number after MEHP exposure. Further, the interrogation of the testis transcriptome was profiled from both the MEHP-responsive peripubertal rats and the less sensitive rodents via 3' Tag sequencing. Significant changes in gene expression were observed in peripubertal rats after MEHP exposure. However, adult rats showed lesser changes in gene expression, and peripubertal mice showed only minor changes. Collectively, the data show that PTMφ numbers are associated with the sensitivity of rodents to MEHP in an age- and species-dependent manner.

Flavivirus genome recoding by codon optimisation confers genetically stable in vivo attenuation in both mice and mosquitoes.

Virus genome recoding is an attenuation method that confers genetically stable attenuation by rewriting a virus genome with numerous silent mutations. Prior flavivirus genome recoding attempts utilised codon deoptimisation approaches. However, these codon deoptimisation approaches act in a species dependent manner and were unable to confer flavivirus attenuation in mosquito cells or in mosquito animal models. To overcome these limitations, we performed flavivirus genome recoding using the contrary approach of codon optimisation. The genomes of flaviviruses such as dengue virus type 2 (DENV2) and Zika virus (ZIKV) contain functional RNA elements that regulate viral replication. We hypothesised that flavivirus genome recoding by codon optimisation would introduce silent mutations that disrupt these RNA elements, leading to decreased replication efficiency and attenuation. We chose DENV2 and ZIKV as representative flaviviruses and recoded them by codon optimising their genomes for human expression. Our study confirms that this recoding approach of codon optimisation does translate into reduced replication efficiency in mammalian, human, and mosquito cells as well as in vivo attenuation in both mice and mosquitoes. In silico modelling and RNA SHAPE analysis confirmed that DENV2 recoding resulted in the extensive disruption of genomic structural elements. Serial passaging of recoded DENV2 resulted in the emergence of rescue or adaptation mutations, but no reversion mutations. These rescue mutations were unable to rescue the delayed replication kinetics and in vivo attenuation of recoded DENV2, demonstrating that recoding confers genetically stable attenuation. Therefore, our recoding approach is a reliable attenuation method with potential applications for developing flavivirus vaccines.

Phytotoxicity and Phytotoxic Substances in Calamus tenuis Roxb.

Calamus tenuis is a shrub species distributed across South Asia. It grows well in diversified habitats and tends to dominate plants in the surrounding environment. The phytotoxicity of C. tenuis and the action of its phytochemicals against other plant species could explain its dominant behavior. Compounds with phytotoxic activity are in high demand as prospective sources of ecofriendly bioherbicides. Therefore, we investigated the phytotoxicity of C. tenuis. Aqueous methanol extracts of this plant species significantly limited the growth of four test plant species, two monocots (barnyard grass and timothy), and two dicots (alfalfa and cress), in a dose- and species-dependent manner. Bio-directed chromatographic isolation of the C. tenuis extracts yielded two major active substances: a novel compound, calamulactone {(S)-methyl 8-(5-oxo-2,5-dihydrofuran-2-yl) octanoate}, and 3-oxo-α-ionone. Both of the identified compounds exerted strong growth inhibitory effects on cress and timothy seedlings. The concentrations of 3-oxo-α-ionone and calamulactone required to limit the growth of the cress seedlings by 50% (I50) were 281.6-199.5 and 141.1-105.5 µM, respectively, indicating that the effect of calamulactone was stronger with lower I50 values. Similarly, the seedlings of timothy also showed a considerably higher sensitivity to calamulactone (I50: 40.5-84.4 µM) than to 3-oxo-α-ionone (I50: 107.8-144.7 µM). The findings indicated that the leaves of C. tenuis have marked growth-inhibitory potential, and could affect surrounding plants to exert dominance over the surrounding plant community. Moreover, the two identified phytotoxic substances might play a key role in the phytotoxicity of C. tenuis, and could be a template for bioherbicide development. This paper was the first to report calamulactone and its phytotoxicity.

SGX523 causes renal toxicity through aldehyde oxidase-mediated less-soluble metabolite formation in chimeric mice with humanized livers

SGX523 is a c-Met tyrosine kinase inhibitor that failed in clinical trials because of renal toxicity caused by crystal deposits in renal tubules. SGX523 is metabolized by aldehyde oxidase (AOX) in a species-dependent manner to the considerably less soluble 2-quinolinone-SGX523, which is likely involved in the clinically observed obstructive nephropathy. This study investigated the metabolism and renal toxicity of SGX523 in chimeric mice with humanized livers (humanized-liver mice). The 2-quinolinone-SGX523 formation activity was higher in humanized-liver mouse and human hepatocytes than in mouse hepatocytes. Additionally, this activity in the liver cytosolic fraction from humanized-liver mice was inhibited by the AOX inhibitors raloxifene and hydralazine. After oral SGX523 administration, higher maximum concentrations, larger areas under the plasma concentration versus time curves, and higher urinary concentrations of 2-quinolinone-SGX523 were observed in humanized-liver mice than in non-humanized mice. Serum creatinine and blood urea nitrogen levels were elevated in humanized-liver mice following repeated oral SGX523 administration. The accumulation of amorphous material in the tubules and infiltration of inflammatory cells around tubules were observed in the kidneys of humanized-liver mice after repeated oral SGX523 administration. These findings demonstrate that humanized-liver mice are useful for understanding the metabolism and toxicity of SGX523.

Ectomycorrhizal Community Shifts at a Former Uranium Mining Site.

Ectomycorrhizal communities at young oak, pine, and birch stands in a former uranium mining site showed a low diversity of morphotypes with a preference for contact and short-distance exploration strategies formed by the fungi Russulaceae, Inocybaceae, Cortinariaceae, Thelephoraceae, Rhizopogonaceae, Tricholomataceae, as well as abundant Meliniomyces bicolor. In order to have better control over abiotic conditions, we established pot experiments with re-potted trees taken from the sites of direct investigation. This more standardized cultivation resulted in a lower diversity and decreased prominence of M. bicolor. In addition, the exploration strategies shifted to include long-distance exploration types. To mimic secondary succession with a high prevalence of fungal propagules present in the soil, inoculation of re-potted trees observed under standardized conditions for two years was used. The super-inoculation increased the effect of lower abundance and diversity of morphotypes. The contact morphotypes correlated with high Al, Cu, Fe, Sr, and U soil contents, the dark-colored short-distance exploration type did not show a specific preference for soil characteristics, and the medium fringe type with rhizomorphs on oaks correlated with total nitrogen. Thus, we could demonstrate that field trees, in a species-dependent manner, selected for ectomycorrhizal fungi with exploration types are likely to improve the plant's tolerance to specific abiotic conditions.

Independent Signaling of Hepatoma Derived Growth Factor and Tumor Necrosis Factor-Alpha in Human Gastric Cancer Organoids Infected by Helicobacter pylori.

We prepared three-dimensional (3-D) organoids of human stomach cancers and examined the correlation between the tumorigenicity and cytotoxicity of Helicobacter pylori (H. pylori). In addition, the effects of hepatoma-derived growth factor (HDGF) and tumor necrosis factor (TNFα) on the growth and invasion activity of H. pylori-infected gastric cancer organoids were examined. Cytotoxin-associated gene A (CagA)-green fluorescence protein (GFP)-labeled H. pylori was used to trace the infection in gastric organoids. The cytotoxicity of Cag encoded toxins from different species of H. pylori did not affect the proliferation of each H. pylori-infected cancer organoid. To clarify the role of HDGF and TNFα secreted from H. pylori-infected cancer organoids, we prepared recombinant HDGF and TNFα and measured the cytotoxicity and invasion of gastric cancer organoids. HDGF controlled the growth of each organoid in a species-specific manner of H. pylori, but TNFα decreased the cell viability in H. pylori-infected cancer organoids. Furthermore, HDGF controlled the invasion activity of H. pylori-infected cancer organoid in a species-dependent manner. However, TNFα decreased the invasion activities of most organoids. We found different signaling of cytotoxicity and invasion of human gastric organoids in response to HDGF and TNFα during infection by H. pylori. Recombinant HDGF and TNFα inhibited the development and invasion of H. pylori-infected gastric cancer differently. Thus, we propose that HDGF and TNFα are independent signals for development of H. pylori-infected gastric cancer. The signaling of growth factors in 3-D organoid culture systems is different from those in two-dimensional cancer cells.

Phylogeny-guided genome mining of roseocin family lantibiotics to generate improved variants of roseocin

Roseocin, the two-peptide lantibiotic from Streptomyces roseosporus, carries extensive intramolecular (methyl)lanthionine bridging in the peptides and exhibits synergistic antibacterial activity against clinically relevant Gram-positive pathogens. Both peptides have a conserved leader but a diverse core region. The biosynthesis of roseocin involves post-translational modification of the two precursor peptides by a single promiscuous lanthipeptide synthetase, RosM, to install an indispensable disulfide bond in the Rosα core along with four and six thioether rings in Rosα and Rosβ cores, respectively. RosM homologs in the phylum actinobacteria were identified here to reveal twelve other members of the roseocin family which diverged into three types of biosynthetic gene clusters (BGCs). Further, the evolutionary rate among the BGC variants and analysis of variability within the core peptide versus leader peptide revealed a phylum-dependent lanthipeptide evolution. Analysis of horizontal gene transfer revealed its role in the generation of core peptide diversity. The naturally occurring diverse congeners of roseocin peptides identified from the mined novel BGCs were carefully aligned to identify the conserved sites and the substitutions in the core peptide region. These selected sites in the Rosα peptide were mutated for permitted substitutions, expressed heterologously in E. coli, and post-translationally modified by RosM in vivo. Despite a limited number of generated variants, two variants, RosαL8F and RosαL8W exhibited significantly improved inhibitory activity in a species-dependent manner compared to the wild-type roseocin. Our study proves that a natural repository of evolved variants of roseocin is present in nature and the key variations can be used to generate improved variants.

On the Chemical Purity and Oxygen Isotopic Composition of α-Cellulose Extractable from Higher Plants and the Implications for Climate, Metabolic, and Physiological Studies.

The 18O/16O ratio of α-cellulose in land plants has proved of interest for climate, environmental, physiological, and metabolic studies. Reliable application of such a ratio may be compromised by the presence of hemicellulose impurities in the α-cellulose product obtainable with current extraction methods, as the impurities are known to be isotopically different from that of the α-cellulose. We first compared the quality of hydrolysates of "α-cellulose products" obtained with four representative extraction methods (Jayme and Wise; Brendel; Zhou; Loader) and quantified the hemicellulose-derived non-glucose sugars in the α-cellulose products from 40 land grass species using gas chromatography-mass spectrometry (GC/MS). Second, we performed compound-specific isotope analysis of the hydrolysates using GC/Pyrolysis/IRMS. These results were then compared with the bulk isotope analysis using EA/Pyrolysis/IRMS of the α-cellulose products. We found that overall, the Zhou method afforded the highest purity α-cellulose as judged by the minimal presence of lignin and the second-lowest presence of non-glucose sugars. Isotopic analysis then showed that the O-2-O-6 of the α-cellulose glucosyl units were all depleted in 18O by 0.0-4.3 mUr (average, 1.9 mUr) in a species-dependent manner relative to the α-cellulose products. The positive isotopic bias of using the α-cellulose product instead of the glucosyl units stems mainly from the fact that the pentoses that dominate hemicellulose contamination in the α-cellulose product are relatively enriched in 18O (compared to hexoses) as they inherit only the relatively 18O-enriched O-2-O-5 moiety of sucrose, the common precursor of pentoses and hexoses in cellulose, and are further enriched in 18O by the (incomplete) hydrolysis.

Integration of omics studies indicates that species-dependent molecular mechanisms govern male fertility

BackgroundComparative and comprehensive omics studies have recently been conducted to provide a comprehensive understanding of the biological mechanisms underlying infertility. However, because these huge omics datasets often contain irrelevant information, editing strategies for summarizing and filtering the data are necessary prerequisite steps for identifying biomarkers of male fertility. Here, we attempted to integrate omics data from spermatozoa with normal and below-normal fertility from boars and bulls, including transcriptomic, proteomic, and metabolomic data. Pathway enrichment analysis was conducted and visualized using g:Profiler, Cytoscape, EnrichmentMap, and AutoAnnotation to determine fertility-related biological functions according to species.ResultsIn particular, gamete production and protein biogenesis-associated pathways were enriched in bull spermatozoa with below-normal fertility, whereas mitochondrial-associated metabolic pathways were enriched in boar spermatozoa with normal fertility. These results indicate that below-normal fertility may be determined by aberrant regulation of protein synthesis during spermatogenesis, and the modulation of reactive oxygen species generation to maintain capacitation and the acrosome reaction governs boar sperm fertility.ConclusionOverall, this approach demonstrated that distinct molecular pathways drive sperm fertility in mammals in a species-dependent manner. Moreover, we anticipate that searching for species-specific signaling pathways may aid in the discovery of fertility-related biomarkers within large omics datasets.

Effects of CeO2 Nanoparticles on Nutritional Quality of Two Crop Plants, Corn (Zea mays L.) and Soybean (Glycine max L.)

With the widespread applications of manufactured nanoparticles (NPs), there are increasing concerns about their potential adverse effects on the environment and living systems. Many studies demonstrated that NPs could significantly affect the growth and development of crop plants. However, knowledge regarding the impacts of NPs on crop quality is rather limited. In this study, the effects of CeO2 NPs (25, 75, and 225 mg Ce/kg) and CeCl3 (25 mg Ce/kg) on the nutritional components of soil-cultivated corn and soybean plants were evaluated. Both treatments tended to decrease the dry weight of grain per plant, while only 225 mg/kg CeO2 NPs on soybean and CeCl3 on corn showed statistical significance compared with the respective control. CeO2 NPs at 225 mg/kg significantly decreased the content of starch in the corn kernels by 18.2% but increased total phenols in soybean seeds by 18.4%. Neither CeO2 NPs nor CeCl3 significantly affected the contents of minerals in corn kernels except for Zn. However, in the case of soybean, the two treatments tended to decrease the contents of P, Zn, Mn, and Mo but increase the content of S. Overall, the results suggest that CeO2 NPs and Ce3+ ions showed similar but not identical effects on corn and soybean plants. CeO2 NPs affect the nutritional quality of crop plants in a species-dependent manner.

Enhanced IRE1α Phosphorylation/Oligomerization-Triggered XBP1 Splicing Contributes to Parkin-Mediated Prevention of SH-SY5Y Cell Death under Nitrosative Stress.

Mutations in parkin, a neuroprotective protein, are the predominant cause of autosomal recessive juvenile Parkinson's disease. Neuroinflammation-derived nitrosative stress has been implicated in the etiology of the chronic neurodegeneration. However, the interactions between genetic predisposition and nitrosative stress contributing to the degeneration of dopaminergic (DA) neurons remain incompletely understood. Here, we used the SH-SY5Y neuroblastoma cells to investigate the function of parkin and its pathogenic mutants in relation to cell survival under nitric oxide (NO) exposure. The results showed that overexpression of wild-type parkin protected SH-SY5Y cells from NO-induced apoptosis in a reactive oxygen species-dependent manner. Under nitrosative stress conditions, parkin selectively upregulated the inositol-requiring enzyme 1α/X-box binding protein 1 (IRE1α/XBP1) signaling axis, an unfolded protein response signal through the sensor IRE1α, which controls the splicing of XBP1 mRNA. Inhibition of XBP1 mRNA splicing either by pharmacologically inhibiting IRE1α endoribonuclease activity or by genetically knocking down XBP1 interfered with the protective activity of parkin. Furthermore, pathogenic parkin mutants with a defective protective capacity showed a lower ability to activate the IRE1α/XBP1 signaling. Finally, we demonstrated that IRE1α activity augmented by parkin was possibly mediated through interacting with IRE1α to regulate its phosphorylation/oligomerization processes, whereas mutant parkin diminished its binding to and activation of IRE1α. Thus, these results support a direct link between the protective activity of parkin and the IRE1α/XBP1 pathway in response to nitrosative stress, and mutant parkin disrupts this function.

Molecular and Phenotypic Responses of Rhizobacteria-Treated Tomato Plants to Tomato Mosaic Virus Under Greenhouse Conditions.

Tomato mosaic disease, mainly caused by Tomato mosaic virus (ToMV), is one of the devastating viral diseases which adversely affects tomato yield, globally. Plant growth-promoting rhizobacteria (PGPR) have been recently used as bio-elicitors to induce resistance against plant viruses. The goal of this research was to apply PGPR in the tomato rhizosphere and to determine the response of plants challenged with ToMV infection, under greenhouse conditions. Two different strains of PGPR, Pseudomonas fluorescens SM90 and Bacillus subtilis DR06, in single- and double-application methods applied to evaluate their effectiveness in inducing defense-related genes, viz., NPR1, COI1, and PR1-a before (induced systemic resistance [ISR]-prime) and after (ISR-boost) ToMV challenge. Additionally, to investigate the biocontrol potential of PGPR-treated plants against viral infection, plant growth indices, ToMV accumulation, and disease severity were compared in primed and non-primed plants. Analysis of expression patterns of putative defense-related genes before and after ToMV infection indicated that studied PGPR trigger defense priming through different signaling pathways acting at the transcriptional level and in a species-dependent manner. Moreover, the biocontrol efficacy of consortium treatment did not differ significantly from the single bacteria treatments, even though their mode of action differed in transcriptional changes of ISR-induced genes. Instead, simultaneous application of Pseudomonas fluorescens SM90 and Bacillus subtilis DR06 led to more significant growth indices than the single treatments suggesting that integrated application of the PGPR could additively reduce the disease severity and virus titer and promote the growth of the tomato plant. These results suggested that enhanced defense priming via activation of the expression pattern of defense-related genes is responsible for biocontrol activity and growth promotion in PGPR-treated tomato plants challenged with ToMV compared to non-primed plants, under greenhouse conditions.

Climate Change and Its Impact on Crops: A Comprehensive Investigation for Sustainable Agriculture

Plants are a highly advanced kingdom of living organisms on the earth. They survive under all climatic and weather variabilities, including low and high temperature, rainfall, radiation, less nutrients, and high salinity. Even though they are adapted to various environmental factors, which are variable, the performance of a crop will be compensated under sub/supra optimal conditions. Hence, current and future climate change factors pose a challenge to sustainable agriculture. Photosynthesis is the primary biochemical trait of crops that are affected by abiotic stress and elevated CO2 (eCO2). Under eCO2, the C3 legumes could perform better photosynthesis over C4 grasses. The associated elevated temperature promotes the survival of the C4 crop (maize) over C3 plants. In the American Ginseng, the elevated temperature promotes the accumulation of phytocompounds. Under less water availability, poor transpirational cooling, higher canopy temperatures, and oxidative stress will attenuate the stability of the membrane. Altering the membrane composition to safeguard fluidity is a major tolerance mechanism. For protection and survival under individual or multiple stresses, plants try to undergo high photorespiration and dark respiration, for instance, in wheat and peas. The redox status of plants should be maintained for ROS homeostasis and, thereby, plant survival. The production of antioxidants and secondary metabolites may keep a check on the content of oxidating molecules. Several adaptations, such as deeper rooting, epicuticular wax formation such as peas, and utilization of non-structural carbohydrates, i.e., wheat, help in survival. In addition to yield, quality is a major attribute abridged or augmented by climate change. The nutrient content of cereals, pulses, and vegetables is reduced by eCO2; in aniseed and Valeriana sp., the essential oil content is increased. Thus, climate change has perplexing effects in a species-dependent manner, posing hurdles in sustainable crop production. The review covers various scientific issues interlinked with challenges of food/nutritional security and the resilience of plants to climate variability. This article also glimpses through the research gaps present in the studies about the physiological effects of climate change on various crops.

Immunoregulatory CD71+ Erythroid Cells (CECs) Expand in Multiple Myeloma and Impair Control of L. Monocytogenes Infection

Introduction Although the clinical management of multiple myeloma (MM) patients has significantly improved over recent years, MM remains a largely incurable disease. One of the most common complication of MM, which correlates with the worse clinical outcome, is anemia. Moreover, MM patients are prone to develop life-threatening infections mainly due to the disease-related impairment of the immune system function. Recently, CD71+ erythroid progenitor and precursor cells (CECs) arose as a relevant immunomodulatory population. CECs have been shown to create an immunosuppressive microenvironment via multiple mechanisms including arginase 2 (ARG2), PDL-1, and TGF-beta. It was recently observed in our laboratory that mice bearing late-stage tumors are characterized by the presence of an increased percentage of CECs in their blood and spleens. Moreover, the tumor-associated CECs show elevated levels of arginases. The abovementioned facts may suggest an important role of CECs and their related mechanisms in compromising the immune response in MM. Methods Vk*MYC MM model Recipient C57BL/6 (wild type or ARG2 KO) mice were injected via tail vein with 1 × 106 Vk*MYC cells. M-spike levels were evaluated with serum protein electrophoresis. Five weeks later they were challenged with L. monocytogenes. L.monocytogenes infection and bacterial burden evaluation Mice were injected intraperitoneally with 1 x 103L. monocytogenes cells (strain EGDe). Bacterial burden was analyzed 72h and 7 days post infection. Briefly, spleens and livers of sacrificed mice were isolated, weighed, and homogenized. The homogenates were serially diluted and plated on culture plates. Bacterial burden was calculated using the number of colonies and the dilution factor. Flow cytometry analysis Flow cytometry analyses (immunophenotyping of spleen and bone marrow (BM) cells as well as cytokine beads arrays, Legenplex, BioLegend) were performed using BD Fortessa X-20 flow cytometer operated by BD FACSDiva Software ver. 8.0. The acquired data were re-analyzed using FlowJo™ ver. 10 software. Arginase inhibitor OAT-1746 arginase inhibitor (Molecure SA) was administered intraperitoneally at doses of 5 or 20 mg/kg twice daily, starting from the second or the fifth day before the bacterial challenge, respectively. The treatment was continued until the end of the experiment. Results In Vk*MYC-bearing mice we observed an accumulation of CECs in the blood and spleen in time, correlating with the development of anemia. At the late stage of the disease MM-associated CECs showed less differentiated phenotype and increased expression of arginase-1 (ARG1) and ARG2. MM-associated CECs inhibited T cells activation and proliferation in an ARG and reactive oxygen species-dependent manner. Interestingly, MM development was delayed in ARG2 KO vs WT mice. In the BM aspirates of MM patients we observed increased percentage of CECs expressing high levels of both ARG1 and ARG2 comparing with healthy controls. Moreover, MM impaired control of L. monocytogenes infection as we observed an elevated bacterial burden in the livers and spleens of Vk*MYC-bearing vs control mice. Infected MM-bearing mice had fewer NK cells and activated CD4+ and CD8+ T cells in the spleen than infected control mice. Furthermore, MM altered the dynamics of cytokines involved in the control of intracellular infection. 24h post Listeria challenge we observed their significant decrease followed by an increase at 72h comparing to infected non-MM mice. These results indicate that MM-bearing mice have delayed initial immune response leading to increased bacterial burden followed by excessive cytokines response resulting in sepsis-like condition leading to increased mice mortality. Finally, ARG inhibitor decreased L. monocytogenes burden in MM-bearing mice. Altogether, our results show that accumulation of CECs during MM progression leads to impaired bacterial infection control, at least partially dependent on ARG2 activity. Funding: National Science Centre in Poland [grants No 2017/25/B/NZ6/01139 and 2019/35/B/NZ6/00540]; Polish Ministry of Education and Science [grant No 013/RID/2018/19 (Regional Initiative for Excellence, project budget 12,000,000 PLN)].