Role of a novel fimbrial adhesin in acid-induced host adhesion of escherichia coli 0157:H7

Enterohemorrhagic Eschericia coli (EHEC) 0157:H7 must be able to survive the acid stress of gastric passage. Previous studies show that adhesion of EHEC 0157:H7 to human epithelial cells is increased if EHEC was pre-exposed to acid. Whole genome array analysis of EHEC reveals that the putative fimbrial gene yadK is significantly upregulated after EHEC exposure to acid treatments. In this study, a YadK deficient mutant (△yadK) in EHEC 0157:H7 wild-type (WT) strain 85-170 was constructed and phenotyped. The results of this study demonstrate that △yadK exposed to acid stress showed no acid-induced increase in bacteria-host cell adhesion observed in similarly acid-induced wild type cells. This study concludes that YadK plays a role in acid-induced host adhesion of EHEC 0157:H7. It also indicates that acid stress, which is a part of the host’s natural assault to resist invasion, may regulate factors responsible for enhanced bacteria-host attachment, resulting in increased EHEC virulence.

Role of a novel fimbrial adhesin in acid-induced host adhesion of escherichia coli 0157:H7

Enterohemorrhagic Eschericia coli (EHEC) 0157:H7 must be able to survive the acid stress of gastric passage. Previous studies show that adhesion of EHEC 0157:H7 to human epithelial cells is increased if EHEC was pre-exposed to acid. Whole genome array analysis of EHEC reveals that the putative fimbrial gene yadK is significantly upregulated after EHEC exposure to acid treatments. In this study, a YadK deficient mutant (△yadK) in EHEC 0157:H7 wild-type (WT) strain 85-170 was constructed and phenotyped. The results of this study demonstrate that △yadK exposed to acid stress showed no acid-induced increase in bacteria-host cell adhesion observed in similarly acid-induced wild type cells. This study concludes that YadK plays a role in acid-induced host adhesion of EHEC 0157:H7. It also indicates that acid stress, which is a part of the host’s natural assault to resist invasion, may regulate factors responsible for enhanced bacteria-host attachment, resulting in increased EHEC virulence.

Altered mRNA Expression Due to Rectum Perforation in a Porcine Model – A Pilot Study

BackgroundAnastomotic leakage is the most serious and unwelcome complication in rectal surgery. It has a great impact on postoperative morbidity and mortality. In this pilot study changes of mRNA expression in blood were analyzed in an animal model designed to imitate anastomotic leakage.Materials and MethodsTwelve pigs were randomized into two groups. A control group and an experimental group, there an iatrogenic rectal perforation was performed. The changes in the mRNA expression were studied four hours after the perforation. Microarray analysis was performed using the Gene Chip whole porcine genome array.Results19 124 mRNA genes were investigated. Significantly increased levels of genes with a fold change (FC) over 2 were found, including 276 genes coding for an unknown protein and 48 mRNA coded for a known protein. Eleven of the genes which coded for a known protein were highly up-regulated with an FC >4.ConclusionEleven known genes were consistently up-regulated after the rectal perforation. These genes were mainly involved in inflammatory response, intracellular signaling and cell membrane regulation. Their corresponding proteins could potentially be clinical biomarkers of anastomotic leakage and should be evaluated in further clinical studies.

FrozenChicken: Promoting the meta-analysis of chicken microarray data

The FrozenChicken RData package, contains the frozen vectors for the commercially available (in situ oligonucleotide) Affymetrix Chicken Genome Array (GEO platform id GPL3213). This package will promote, simplify, and ease the meta-analysis of chicken microarray data by the research community studying vertebrate development using the chick model organism. The package is freely available in https://github.com/iduarte/FrozenChicken. (*Equal contribution.)

Basal differences in the transcriptional profiles of tomato leaves associated with the presence/absence of the resistance gene Mi-1 and changes in these differences after infestation by the whitefly Bemisia tabaci

The tomato Mi-1 gene mediates plant resistance to whitefly Bemisia tabaci, nematodes, and aphids. Other genes are also required for this resistance, and a model of interaction between the proteins encoded by these genes was proposed. Microarray analyses were used previously to identify genes involved in plant resistance to pests or pathogens, but scarcely in resistance to insects. In the present work, the GeneChip™ Tomato Genome Array (Affymetrix®) was used to compare the transcriptional profiles of Motelle (bearing Mi-1) and Moneymaker (lacking Mi-1) cultivars, both before and after B. tabaci infestation. Ten transcripts were expressed at least twofold in uninfested Motelle than in Moneymaker, while other eight were expressed half or less. After whitefly infestation, differences between cultivars increased to 14 transcripts expressed more in Motelle than in Moneymaker and 14 transcripts less expressed. Half of these transcripts showed no differential expression before infestation. These results show the baseline differences in the tomato transcriptomic profile associated with the presence or absence of the Mi-1 gene and provide us with valuable information on candidate genes to intervene in either compatible or incompatible tomato–whitefly interactions.

Endothelial specific PER2 at the crossroads of light elicited circadian amplitude enhancement as novel cardioprotective strategy and transcriptional regulation of HIF1A-dependent metabolic adaptation to myocardial ischemia

ABSTRACTConsistent daylight oscillations and abundant oxygen availability are fundamental to human health. While both are connected from an evolutionary and cellular perspective, only oxygen is an established therapy in cardiovascular medicine. Here, we probe the mechanistic intersection between light-(Period 2, PER2) and oxygen-(hypoxia inducible factor, HIF1A) sensing pathways in cellular adaptation to low oxygen conditions with respect to myocardial ischemia.Using a whole genome array from daylight exposed wildtype orPer2−/−mice, an affinity purification-mass spectrometry-based proteomics screen for PER2 targets in hypoxic human endothelial cells, and targeted metabolomics from human healthy volunteers after daylight therapy, we investigated the intersection of light and hypoxia elicited pathways. Housing mice under daylight conditions prior to myocardial ischemia and reperfusion (IR)-injury, uncovered circadian PER2 amplitude enhancement as novel cardioprotective strategy, mimicking HIF1A metabolic adaptation to myocardial ischemia in a PER2 regulated manner. Whole genome array analysis from daylight exposed wildtype andPer2−/−mice or myocardial IR-injury in endothelial specific PER2 deficient mice (Per2loxP/loxP-VE-Cadherin -Cre) revealed a critical role for light elicited PER2 in maintaining the endothelial barrier function during myocardial ischemia. Mechanistic studies in human endothelia pointed towards a master transcriptional regulatory role for endothelial PER2 in metabolic reprograming to hypoxia via HIF1A, which was mimicked during normoxic PER2 stabilization. Translational investigation of light elicited pathways in human healthy volunteers found similar increases of PER2 or mimicking of HIF1A dependent metabolism. These studies identify light elicited circadian amplitude enhancement of endothelial PER2 as a novel cardioprotective strategy. Furthermore, these studies identify PER2 as critical control point of endothelial metabolic reprograming to maintain vascular integrity during myocardial IR-injury and implicate the use of daylight therapy to increase endothelial PER2 signaling as a strategy for the treatment of coronary artery disease.

Genome-wide analysis reveals signatures of selection for gait traits in Yili horse

High quality gaits play an important role in many breeding programs, but the genes of gait were limited at the moment. Here, we present an analysis of genomic selection signatures in 53 individuals from two breeds, using genotype data from the Affymetrix Equine 670K SNP genotyping array. The 11 selection regions of Yili horse were identified using an FST statistic and XP-EHH calculated in 200-kb windows across the genome. In total, 50 genes could be found in the 11 regions, and two candidate genes related to locomotory behavior (CLN6, FZD4). The genome of Yili horse and Russian horse were shaped by natural and artificial selection. Our results suggest that gait trait of Yili horse may related to two genes. This is the first time when whole genome array data is utilized to study genomic regions affecting gait in Yili horse breed.