Pathogen Gene Expression Research Articles

Transcriptional profiling during infection of potato NLRs and Phytophthora infestans effectors using cDNA enrichment sequencing

An accurate assessment of host and pathogen gene expression during infection is critical for understanding the molecular aspects of host-pathogen interactions. Often, pathogen-derived transcripts are difficult to ascertain at early infection stages owing to the unfavourable transcript representation compared to the host genes. In this study, we compare two sequencing techniques, RNAseq and enrichment sequencing (RenSeq and PenSeq) of cDNA, to investigate gene expression patterns in the doubled monoploid potato (DM) infected with the late blight pathogen Phytophthora infestans. Our results reveal distinct advantages of cDNA RenSeq and PenSeq over traditional RNAseq in terms of target gene representation and transcriptional quantification at early infection stages. Throughout the infection time course, cDNA enrichment sequencing enables transcriptomic analyses for more targeted host and pathogen genes. For highly expressed genes that were sampled in parallel by both cDNA enrichment and RNAseq, a high level of concordance in expression profiles is observed, indicative of at least semi-quantitative gene expression representation following enrichment

Analysis of Plant and Fungal Transcripts from Resistant and Susceptible Phenotypes of Leptospermum scoparium Challenged by Austropuccinia psidii.

Austropuccinia psidii is the causal pathogen of myrtle rust disease of Myrtaceae. To gain understanding of the initial infection process, gene expression in germinating A. psidii urediniospores and in Leptospermum scoparium-inoculated leaves were investigated via analyses of RNA sequencing samples taken 24 and 48 h postinoculation (hpi). Principal component analyses of transformed transcript count data revealed differential gene expression between the uninoculated L. scoparium control plants that correlated with the three plant leaf resistance phenotypes (immunity, hypersensitive response, and susceptibility). Gene expression in the immune resistant plants did not significantly change in response to fungal inoculation, whereas susceptible plants showed differential expression of genes in response to fungal challenge. A putative disease resistance gene, jg24539.t1, was identified in the L. scoparium hypersensitive response phenotype family. Expression of this gene may be associated with the phenotype and could be important for further understanding the plant hypersensitive response to A. psidii challenge. Differential expression of pathogen genes was found between samples taken 24 and 48 hpi, but there were no significant differences in pathogen gene expression that were associated with the three different plant leaf resistance phenotypes. There was a significant decrease in the abundance of fungal transcripts encoding three putative effectors and a putative carbohydrate-active enzyme between 24 and 48 hpi, suggesting that the encoded proteins are important during the initial phase of infection. These transcripts, or their translated proteins, may be potential targets to impede the early phases of fungal infection by this wide-host-range obligate biotrophic basidiomycete.

Impact of Exogenous dsRNA on miRNA Composition in Arabidopsis thaliana.

The application of double-stranded RNAs (dsRNAs) to plant surfaces has emerged as a promising tool for manipulating gene expression in plants and pathogens, offering new opportunities for crop improvement. While research has shown the capability of exogenous dsRNAs to silence genes, the full spectrum of their impact, particularly on the intricate network of microRNAs (miRNAs), remains largely unexplored. Here, we show that the exogenous application of chalcone synthase (CHS)-encoding dsRNA to the rosette leaves of Arabidopsis thaliana induced extensive alterations in the miRNA profile, while non-specific bacterial neomycin phosphotransferase II (NPTII) dsRNA had a minimal effect. Two days after treatment, we detected 60 differentially expressed miRNAs among the 428 miRNAs found in the A. thaliana genome. A total of 59 miRNAs were significantly changed after AtCHS-dsRNA treatment compared with water and NPTII-dsRNA, and 1 miRNA was significantly changed after AtCHS-dsRNA and NPTII-dsRNA compared with the water control. A comprehensive functional enrichment analysis revealed 17 major GO categories enriched among the genes potentially targeted by the up- and downregulated miRNAs. These categories included processes such as aromatic compound biosynthesis (a pathway directly related to CHS activity), heterocycle biosynthesis, RNA metabolism and biosynthesis, DNA transcription, and plant development. Several predicted targets of upregulated and downregulated miRNAs, including APETALA2, SCL27, SOD1, GRF1, AGO2, PHB, and PHV, were verified by qRT-PCR. The analysis showed a negative correlation between the expression of miRNAs and the expression of their predicted targets. Thus, exogenous plant gene-specific dsRNAs induce substantial changes in the plant miRNA composition, ultimately affecting the expression of a wide range of genes. These findings have profound implications for our understanding of the effects of exogenously induced RNA interference, which can have broader effects beyond targeted mRNA degradation, affecting the expression of other genes through miRNA regulation.

The glycolytic reaction PGAM unexpectedly restrains Th17 pathogenicity and Th17-dependent autoimmunity.

Glucose metabolism is a critical regulator of T cell function, largely thought to support their activation and effector differentiation. Here, we investigate the relevance of individual glycolytic reactions in determining the pathogenicity of T helper 17 (Th17) cells using single-cell RNA-seq and Compass, an algorithm we previously developed for estimating metabolic flux from single-cell transcriptomes. Surprisingly, Compass predicted that the metabolic shunt between 3-phosphoglycerate (3PG) and 2-phosphoglycerate (2PG) is inversely correlated with pathogenicity in these cells, whereas both its upstream and downstream reactions were positively correlated. Perturbation of phosphoglycerate mutase (PGAM), an enzyme required for 3PG to 2PG conversion, resulted in an increase in protein expression of IL2, IL17, and TNFa, as well as induction of a pathogenic gene expression program. Consistent with PGAM playing a pro-regulatory role, inhibiting PGAM in Th17 cells resulted in exacerbated autoimmune responses in the adoptive transfer model of experimental autoimmune encephalomyelitis (EAE). Finally, we further investigated the effects of modulating glucose concentration on Th17 cells in culture. Th17 cells differentiated under high- and low-glucose conditions substantially differed in their metabolic and effector transcriptomic programs, both central to Th17 function. Importantly, the PGAM-dependent gene module marks the least pathogenic state of Th17 cells irrespective of glucose concentration. Overall, our study identifies PGAM, contrary to other glycolytic enzymes, as a negative regulator of Th17 pathogenicity.

Exploring computational approaches to design mRNA Vaccine against vaccinia and Mpox viruses.

Messenger RNA (mRNA) vaccines emerged as a powerful tool in the fight against infections. Unlike traditional vaccines, this unique type of vaccine elicits robust and persistent innate and humoral immune response with a unique host cell-mediated pathogen gene expression and antigen presentation. This offers a novel approach to combat poxviridae infections. From the genome of vaccinia and Mpox viruses, three key genes (E8L, E7R, and H3L) responsible for virus attachment and virulence were selected and employed for designing the candidate mRNA vaccine against vaccinia and Mpox viral infection. Various bioinformatics tools were employed to generate (B cell, CTL, and HTL) epitopes, of which 28 antigenic and immunogenic epitopes were selected and are linked to form the mRNA vaccine construct.Additional components, including a 5' cap, 5' UTR, adjuvant, 3' UTR, and poly(A) tail, were incorporated to enhance stability and effectiveness.Safety measures such as testing for human homology and in silico immune simulations were implemented to avoid autoimmunity and to mimics the immune response of human host to the designed mRNA vaccine, respectively. The mRNA vaccine's binding affinity was evaluated by docking it with TLR-2, TLR-3, TLR-4, and TLR-9 receptors which are subsequently followed by molecular dynamics simulations for the highest binding one to predict the stability of the binding complex. With a 73% population coverage, the mRNA vaccine looks promising, boasting a molecular weight of 198 kDa and a molecular formula of C8901H13609N2431O2611S48 and it is said to be antigenic, nontoxic and nonallergic, making it safe and effective in preventing infections with Mpox and vaccinia viruses, in comparison with other insilico-designed vaccine for vaccinia and Mpox viruses. However, further validation through in vivo and in vitro techniques is underway to fully assess its potential.

Sheath Blight and Bacterial Blight Resistance in Rice: Mechanisms, Progress and Future Perspectives for Sustainable Rice Production

Rice (Oryza sativa L.) is a staple food for nearly half of the world's population, including Pakistan. But several diseases are always posing a threat to rice farming, with bacterial blight and sheath blight being the two most common causes. R. solani is the main source of rice sheath blight and stood crop’s most destructive diseases. Reviewing published data on pathogenicity and disease management is crucial to developing effective crop protection against sheath blight. It also helps identify research gaps that need more in-depth investigation. Although there has been progress in identifying rice and pathogen-related genes linked to pathogenesis, the underlying processes are still unknown. Research on the applications of; agronomic techniques, chemical control, biological control, and genetic improvement in disease management strategies has been conducted. Optimizing the application of nitrogen fertilizer in combination to plant-plant spacing can minimize the transmission of infection, whereas SMART agricultural technologies; like crop monitoring using Unmanned Aerial Systems help detect and treat sheath blight disease early on. Biological agents and natural fungicides can be used to effectively prevent sheath blight while reducing the negative effects on the environment. Genetic strategies that hold potential to control sheath blight include the use of exogenous dsRNA to suppress pathogen gene expression, genome editing to create rice lines less susceptible to sheath blight, and the development of transgenic rice lines that over express or silence genes related to pathogenesis. The pathogen’s flexibility, the absence of resistant rice types, the lack of single resistance genes for breeding, and farmers' restricted access to informative programs about optimum management methods all work against effective crop protection against sheath blight.

Effects of intrinsic and extrinsic growth factors on virulence gene expression of foodborne pathogens in vitro and in food model systems; a review

AbstractSince foodborne diseases are one of the major causes of human hospitalization and death, one of the main challenges to food safety is the elimination or reduction of pathogens from food products throughout the food production chain. Pathogens, such as Salmonella species, Escherichia coli, Bacillus cereus, Clostridium species, Staphylococcus aureus, Listeria monocytogenes, Campylobacter species, etc., enter the consumer's body through the consumption of contaminated food and eventually cause disease, disability, and death in humans. In particular, the expression of virulence genes of these pathogens in various food environments containing them has been repeatedly reported, which is a key issue for the survival and pathogenicity of the pathogen. Hence, in this review, the interventions to prevent and control foodborne diseases, such as the application of natural preservatives, redox potential, heat treatments, high‐pressure processing, and gaseous atmosphere, are discussed based on the literature. Moreover, the effects of various environmental conditions on bacterial gene expression are comprehensively reviewed. In conclusion, the effects of intrinsic and extrinsic factors on the growth and pathogenicity of bacteria are very complicated. The information obtained from the current study can be used to develop new control strategies, improve food safety, and ensure human health.

A MYB-related transcription factor regulates effector gene expression in an oomycete pathogen.

Phytophthora pathogens possess hundreds of effector genes that exhibit diverse expression patterns during infection, yet how the expression of effector genes is precisely regulated remains largely elusive. Previous studies have identified a few potential conserved transcription factor binding sites (TFBSs) in the promoters of Phytophthora effector genes. Here, we report a MYB-related protein, PsMyb37, in Phytophthora sojae, the major causal agent of root and stem rot in soybean. Yeast one-hybrid and electrophoretic mobility shift assays showed that PsMyb37 binds to the TACATGTA motif, the most prevalent TFBS in effector gene promoters. The knockout mutant of PsMyb37 exhibited significantly reduced virulence on soybean and was more sensitive to oxidative stress. Consistently, transcriptome analysis showed that numerous effector genes associated with suppressing plant immunity or scavenging reactive oxygen species were down-regulated in the PsMyb37 knockout mutant during infection compared to the wild-type P. sojae. Several promoters of effector genes were confirmed to drive the expression of luciferase in a reporter assay. These results demonstrate that a MYB-related transcription factor contributes to the expression of effector genes in P. sojae.

Impact of periodontitis on type 2 diabetes: a bioinformatic analysis

BackgroundPeriodontitis is strongly associated with type 2 diabetes (T2D) that results in serious complications and mortality. However, the pathogenic role of periodontitis in the development of T2D and the underlain mechanism have not been fully elucidated.MethodsA Mendelian randomization (MR) was performed to estimate the causality between two diseases. Bioinformatics tools, including gene ontology and pathway enrichment analyses, were employed to analyze the common differentially expressed genes (DEGs) in periodontitis and T2D. MR and colocalization analyses were then utilized to investigate the causal associations between potential pathogenic gene expression and the risk of T2D. Single cell-type expression analysis was further performed to detect the cellular localization of these genes.ResultsGenetically predicted periodontitis was associated with a higher risk of T2D (OR, 1.469; 95% CI, 1.117–1.930; P = 0.006) and insulin resistance (OR 1.034; 95%CI 1.001–1.068; P = 0.041). 79 common DEGs associated with periodontitis and T2D were then identified and demonstrated enrichment mainly in CXC receptor chemokine receptor binding and interleutin-17 signaling pathway. The integration of GWAS with the expression quantitative trait locis of these genes from the peripheral blood genetically prioritized 6 candidate genes, including 2 risk genes (RAP2A, MCUR1) and 4 protective genes (WNK1, NFIX, FOS, PANX1) in periodontitis-related T2D. Enriched in natural killer cells, RAP2A (OR 4.909; 95% CI 1.849–13.039; P = 0.001) demonstrated high risk influence on T2D, and exhibited strong genetic evidence of colocalization (coloc.abf-PPH4 = 0.632).ConclusionsThis study used a multi-omics integration method to explore causality between periodontitis and T2D, and revealed molecular mechanisms using bioinformatics tools. Periodontitis was associated with a higher risk of T2D. MCUR1, RAP2A, FOS, PANX1, NFIX and WNK1 may play important roles in the pathogenesis of periodontitis-related T2D, shedding light on the development of potential drug targets.

Incremental increases in physiological fluid shear progressively alter pathogenic phenotypes and gene expression in multidrug resistant Salmonella

ABSTRACT The ability of bacteria to sense and respond to mechanical forces has important implications for pathogens during infection, as they experience wide fluid shear fluctuations in the host. However, little is known about how mechanical forces encountered in the infected host drive microbial pathogenesis. Herein, we combined mathematical modeling with hydrodynamic bacterial culture to profile transcriptomic and pathogenesis-related phenotypes of multidrug resistant S. Typhimurium (ST313 D23580) under different fluid shear conditions relevant to its transition from the intestinal tract to the bloodstream. We report that D23580 exhibited incremental changes in transcriptomic profiles that correlated with its pathogenic phenotypes in response to these progressive increases in fluid shear. This is the first demonstration that incremental changes in fluid shear forces alter stress responses and gene expression in any ST313 strain and offers mechanistic insight into how forces encountered by bacteria during infection might impact their disease-causing ability in unexpected ways.

Marine Microorganisms as Potential Source of Quorum-Sensing Inhibitory Compounds

Antibiotics are extensively utilized globally, and the rate of antibiotic resistance is increasing more rapidly than ever. Since the introduction of antibiotics, the overuse of antibiotics caused selection pressure, and almost all pathogenic bacteria have developed resistance against commonly used antibiotics, which is particularly known as antimicrobial resistance (AMR). It has proven challenging to combat and resolve the issue of microbial resistance. A growing number of microorganisms have developed different resistance mechanisms and turned into "superbugs". The identification of quorum-sensing systems has given researchers a new hope for understanding drug resistance processes. The quorum-sensing system controls a number of cellular functions, including the expression of pathogenic genes, the synthesis of toxins, and the synthesis of extracellular polysaccharides. To targeting QS systems marine bacterial samples were collected by different coastal sites of Gujarat, like Mandvi, Dwarka and Diu. A total of 52 marine isolates were obtained, out of which 16 were associated with various marine macro-organisms like sponges and algae, whereas 36 were free-living. The study has done by screening those marine isolates shown potential to inhibiting the quorum sensing molecule by co culture study against Chromobacter violaceium, followed by growth inhibition assay. The G14 and G82 isolate shows highest degradation of N-acyl homoserine lactone by AHL study. The QSI compounds were extracted using ethyl acetate extraction method. Biofilm inhibition assay with Pseudomonas aeruginosa shows potent inhibitory effect of extract. These results prove that marine microorganism have potential to inhibits quorum sensing and virulence factors regulated by Quorum Sensing phenomenon.

Modern Approaches to Enhancing Rust Resistance in Wheat Leading to Global Food Security

Rust diseases pose significant threats to wheat production. The deployment of wheat cultivars endowed with rust resistance stands as the most potent strategy for effective rust management. This resistance is primarily inherited through Mendelian principles discovered in 1905, but traditional breeding methods are time-consuming. Modern strategies have emerged to develop rust-resistant wheat varieties efficiently. Marker-Assisted Selection (MAS) accelerates the breeding process through precise screening, bringing about a revolution in the creation of rust-resistant wheat varieties. Genetic engineering techniques allow the transfer of resistance genes from other species into susceptible crops, but GMO use remains controversial and regulated. Gene editing, especially with CRISPR-Cas9, is a game-changer, enabling the introduction of natural variations or inactivation of critical genes in rust pathogens, enhancing plant resistance. RNA interference (RNAi) is another promising strategy, using small RNA molecules to inhibit rust pathogen gene expression, reducing disease severity. Induced Systemic Resistance (ISR) primes plant immune systems by treating them with beneficial microorganisms or compounds, fortifying them against subsequent rust infections. Eco-friendly biofungicides with antagonistic microorganisms suppress rust infections as alternatives to chemical fungicides. The development of climate-resilient wheat varieties is essential, as they indirectly enhance rust resistance, ensuring stable production amid changing climate conditions. These efforts to improve wheat productivity and rust resistance are crucial for feeding the growing global population. Integrating modern methods with traditional breeding is key to effectively combatting rust diseases and enhancing food security.

Analysis of the therapeutic potential of miR-124 and miR-16 in non-alcoholic fatty liver disease

BackgroundsNon-alcoholic fatty liver disease (NAFLD) is a common condition affecting >25 % of the population worldwide. This disorder ranges in severity from simple steatosis (fat accumulation) to severe steatohepatitis (inflammation), fibrosis and, at its end-stage, liver cancer. A number of studies have identified overexpression of several key genes that are critical in the initiation and progression of NAFLD. MiRNAs are potential therapeutic agents that can regulate several genes simultaneously. Therefore, we transfected cell lines with two key miRNAs involved in targeting NAFLD-related genes. MethodsThe suppression effects of the investigated miRNAs (miR-124 and miR-16) and genes (TNF, TLR4, SCD, FASN, SREBF2, and TGFβ-1) from our previous study were investigated by real-time PCR in Huh7 and HepG2 cells treated with oleic acid. Oil red O staining and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay were utilized to assess cell lipid accumulation and cytotoxic effects of the miRNAs, respectively. The pro-oxidant-antioxidant balance (PAB) assay was undertaken for miR-16 and miR-124 after cell transfection. ResultsFollowing transfection of miRNAs into HepG2, oil red O staining showed miR-124 and miR-16 reduced oleic acid-induced lipid accumulation by 35.2 % and 28.6 % respectively (p < 0.05). In Huh7, miR-124 and miR-16 reduced accumulation by 23.5 % and 31.3 % respectively (p < 0.05) but without impacting anti-oxidant activity. Real-time PCR in HepG2 revealed miR-124 decreased expression of TNF by 0.13-fold, TLR4 by 0.12-fold and SREBF2 by 0.127-fold (p < 0.05). miR-16 decreased TLR4 by 0.66-fold and FASN by 0.3-fold (p < 0.05). In Huh7, miR-124 decreased TNF by 0.12-fold and FASN by 0.09-fold (p < 0.05). miR-16 decreased SCD by 0.28-fold and FASN by 0.64-fold (p < 0.05). MTT assays showed, in HepG2, viability was decreased 24.7 % by miR-124 and decreased 33 % by miR-16 at 72 h (p < 0.05). In Huh7, miR-124 decreased viability 42 % at 48 h and 29.33 % at 72 h (p < 0.05), while miR-16 decreased viability by 32.3 % (p < 0.05). ConclusionThese results demonstrate the ability of miR-124 and miR-16 to significantly reduce lipid accumulation and expression of key pathogenic genes associated with NAFLD through direct targeting. Though this requires further in vivo investigation.

Lipid and Transcriptional Regulation in a Parkinson's Disease Mouse Model by Intranasal Vesicular and Hexosomal Plasmalogen-Based Nanomedicines.

Plasmalogens (vinyl-ether phospholipids) are an emergent class of lipid drugs against various diseases involving neuro-inflammation, oxidative stress, mitochondrial dysfunction, and altered lipid metabolism. They can activate neurotrophic and neuroprotective signaling pathways but low bioavailabilities limit their efficiency in curing neurodegeneration. Here, liquid crystalline lipid nanoparticles (LNPs) are created for the protection and non-invasive intranasal delivery of purified scallop-derived plasmalogens. The in vivo results with a transgenic mouse Parkinson's disease (PD) model (characterized by motor impairments and α-synuclein deposition) demonstrate the crucial importance of LNP composition, which determines the self-assembled nanostructure type. Vesicle and hexosome nanostructures (characterized by small-angle X-ray scattering) display different efficacy of the nanomedicine-mediated recovery of motor function, lipid balance, and transcriptional regulation (e.g., reduced neuro-inflammation and PD pathogenic gene expression). Intranasal vesicular and hexosomal plasmalogen-based LNP treatment leads to improvement of the behavioral PD symptoms and downregulation of the Il6, Il33, and Tnfa genes. Moreover, RNA-sequencing and lipidomic analyses establish a dramatic effect of hexosomal nanomedicines on PD amelioration, lipid metabolism, and the type and number of responsive transcripts that may be implicated in neuroregeneration.

Regulation of effector gene expression as concerted waves in Leptosphaeria maculans: a two-player game.

Effector genes, encoding molecules involved in disease establishment, are concertedly expressed throughout the lifecycle of plant-pathogenic fungi. However, little is known about how effector gene expression is regulated. Since many effector genes are located in repeat-rich regions, the role of chromatin remodeling in their regulation was recently investigated, notably establishing that the repressive histone modification H3K9me3, deposited by KMT1, was involved in several fungal species including Leptosphaeria maculans. Nevertheless, previous data suggest that a second regulatory layer, probably involving a specific transcription factor (TF), might be required. In L. maculans, a Dothideomycete causing stem canker of oilseed rape, we identified the ortholog of Pf2, a TF belonging to the Zn2Cys6 fungal-specific family, and described as essential for pathogenicity and effector gene expression. We investigated its role together with KMT1, by inactivating and over-expressing LmPf2 in a wild-type strain and a ∆kmt1 mutant. Functional analyses of the corresponding transformants highlighted an essential role of LmPf2 in the establishment of pathogenesis and we found a major effect of LmPf2 on the induction of effector gene expression once KMT1 repression is lifted. Our results show, for the first time, a dual control of effector gene expression.

Effect of flow fluctuation on water pollution in drinking water distribution systems

The detachment of biofilm caused by changes in hydraulic conditions is an essential reason for the pollution of water in the drinking water distribution system (DWDS). In this research, the effect of flow fluctuation on bulk water quality was studied. The turbidity, iron concentration, manganese concentration, the total number of bacteria, biodegradable dissolved organic carbon (BDOC), bacterial community structure, and pathogenic genes in bacteria of bulk water were analyzed. The results indicate that the detachment of biofilm caused by fluctuant flow and reverse flow (especially instant reverse flow) can lead to the pollution of water. Throughout the entire experimental period, the turbidity under fluctuant flow velocity is 4.92%∼49.44% higher than that under other flow velocities. BDOC concentration is 5.68%∼53.99% higher than that under low and high flow velocities. The flow fluctuation increases bacterial regrowth potential (BRP) and reduces the biological stability of the bulk water. Low flow velocity is more conducive to the expression of pathogenic functional genes. In the short term, the water quality under low flow velocity is the best. Nevertheless, in a long-term operation (about seven days later), the water quality under high flow velocity is better than that under other flow velocities. This research brings new knowledge about the fluctuant hydraulic conditions on the bulk water quality within the DWDS and provides data support for stable drinking water distribution.

Microbe Interactions within the Skin Microbiome.

The skin is the largest human organ and is responsible for many important functions, such as temperature regulation, water transport, and protection from external insults. It is colonized by several microorganisms that interact with each other and with the host, shaping the microbial structure and community dynamics. Through these interactions, the skin microbiota can inhibit pathogens through several mechanisms such as the production of bacteriocins, proteases, phenol soluble modulins (PSMs), and fermentation. Furthermore, these commensals can produce molecules with antivirulence activity, reducing the potential of these pathogens to adhere to and invade human tissues. Microorganisms of the skin microbiota are also able to sense molecules from the environment and shape their behavior in response to these signals through the modulation of gene expression. Additionally, microbiota-derived compounds can affect pathogen gene expression, including the expression of virulence determinants. Although most studies related to microbial interactions in the skin have been directed towards elucidating competition mechanisms, microorganisms can also use the products of other species to their benefit. In this review, we will discuss several mechanisms through which microorganisms interact in the skin and the biotechnological applications of products originating from the skin microbiota that have already been reported in the literature.

Structural and functional damage to neuronal nuclei caused by extracellular tau oligomers.

Neuronal nuclei are normally smoothly surfaced. In Alzheimer's disease (AD) and other tauopathies, though, they often develop invaginations. We investigated mechanisms and functional consequences of neuronal nuclear invagination in tauopathies. Nuclear invagination was assayed by immunofluorescence in the brain, and in cultured neurons before and after extracellular tau oligomer (xcTauO) exposure. Nucleocytoplasmic transport was assayed in cultured neurons. Gene expression was investigated using nanoString nCounter technology and quantitative reverse transcription polymerase chain reaction. Invaginated nuclei were twice as abundant in human AD as in cognitively normal adults, and were increased in mouse neurodegeneration models. In cultured neurons, nuclear invagination was induced by xcTauOs by an intracellular tau-dependent mechanism. xcTauOs impaired nucleocytoplasmic transport, increased histone H3 trimethylation at lysine 9, and altered gene expression, especially by increasing tau mRNA. xcTauOs may be a primary cause of nuclear invagination in vivo, and by extension, impair nucleocytoplasmic transport and induce pathogenic gene expression changes. Extracellular tau oligomers (xcTauOs) cause neuronal nuclei to invaginate. xcTauOs alter nucleocytoplasmic transport, chromatin structure, and gene expression. The most upregulated gene is MAPT, which encodes tau. xcTauOs may thus drive a positive feedback loop for production of toxic tau.

A combination of burn wound injury and Pseudomonas infection elicits unique gene expression that enhances bacterial pathogenicity.

The interaction between an underlying disease process and a specific pathogen may lead to the unique expression of genes that affect bacterial pathogenesis. These genes may not be observed during infection in the absence of, or with a different underlying process or infection during the underlying process with a different pathogen. To test this hypothesis, we used Nanostring technology to compare gene transcription in a murine-burned wound infected with P. aeruginosa. The Nanostring probeset allowed the simultaneous direct comparison of immune response gene expression in both multiple host tissues and P. aeruginosa in conditions of burn alone, infection alone, and burn with infection. While RNA-Seq is used to discover novel transcripts, NanoString could be a technique to monitor specific changes in transcriptomes between samples and bypass the additional adjustments for multispecies sample processing or the need for the additional steps of alignment and assembly required for RNASeq. Using Nanostring, we identified arginine and IL-10 as important contributors to the lethal outcome of burned mice infected with P. aeruginosa. While other examples of altered gene transcription are in the literature, our study suggests that a more systematic comparison of gene expression in various underlying diseases during infection with specific bacterial pathogens may lead to the identification of unique host-pathogen interactions and result in more precise therapeutic interventions.

Green synthesis of selenium nanoparticles using Artemisia chamaemelifolia: toxicity effects through regulation of gene expression for cancer cells and bacteria

An effective and economical green procedure is reported for the synthesis of selenium nanoparticles (SeNPs) using the extract of Artemisia chamaemelifolia aerial. The as-synthesized SeNPs were characterized using different spectroscopy and microscopy techniques, confirming the formation of about 110 nm SeNPs capped with phytochemicals present in the Artemisia chamaemelifolia aerial extract. The cytotoxicity of the as-synthesized SeNPs was evaluated through their effects on different bacteria and cell lines. The cytotoxicity effect was tested against the tumorigenic human colorectal adenocarcinoma (HT-29) cell line as well as the low-tumorigenic human embryonic kidney (HEK293) cell line. The results suggested that there is less cytotoxicity against HEK293 cells as compared to HT-29 cells. The apoptosis mechanism was further evaluated by investigation of different anti-apoptotic or pro-apoptotic genes expressed in these two cell lines. For the bacterial toxicity evaluation, S. aureus and K. pneumoniae were used. The results suggested considerable toxicity effect against both studied strains. Similarly, the expression levels of hlaA and vgrG-1 genes were evaluated in pathogenic bacteria after treatment with SeNPs. It was found that SeNPs could down-regulate the expression of pathogenic genes (hlaA and vgrG-1 genes in S. aureus and K. pneumoniae strains, respectively). Based on the findings of this study, we believe SeNPs synthesized by plant extract have great potential to be used for biomedical applications and such a non-metal nanoparticle will open new avenues to future medical applications as an anticancer and antibacterial agent.