The role of B-Cell Lymphoma-3 (BCL-3) in enabling the hallmarks of cancer: implications for the treatment of colorectal carcinogenesis.

With its identification as a proto-oncogene in chronic lymphocytic leukaemia and central role in regulating NF-κB signalling, it is perhaps not surprising that there have been an increasing number of studies in recent years investigating the role of BCL-3 (B-Cell Chronic Lymphocytic Leukaemia/Lymphoma-3) in a wide range of human cancers. Importantly, this work has begun to shed light on our mechanistic understanding of the function of BCL-3 in tumour promotion and progression. Here, we summarize the current understanding of BCL-3 function in relation to the characteristics or traits associated with tumourigenesis, termed 'Hallmarks of Cancer'. With the focus on colorectal cancer, a major cause of cancer related mortality in the UK, we describe the evidence that potentially explains why increased BCL-3 expression is associated with poor prognosis in colorectal cancer. As well as promoting tumour cell proliferation, survival, invasion and metastasis, a key emerging function of this proto-oncogene is the regulation of the tumour response to inflammation. We suggest that BCL-3 represents an exciting new route for targeting the Hallmarks of Cancer; in particular by limiting the impact of the enabling hallmarks of tumour promoting inflammation and cell plasticity. As BCL-3 has been reported to promote the stem-like potential of cancer cells, we suggest that targeting BCL-3 could increase the tumour response to conventional treatment, reduce the chance of relapse and hence improve the prognosis for cancer patients.

Genetic and Mechanistic Analyses of the Periplasmic Domain of the Enterohemorrhagic Escherichia coli QseC Histidine Sensor Kinase.

The histidine sensor kinase (HK) QseC senses autoinducer 3 (AI-3) and the adrenergic hormones epinephrine and norepinephrine. Upon sensing these signals, QseC acts through three response regulators (RRs) to regulate the expression of virulence genes in enterohemorrhagic Escherichia coli (EHEC). The QseB, QseF, and KdpE RRs that are phosphorylated by QseC constitute a tripartite signaling cascade having different and overlapping targets, including flagella and motility, the type three secretion system encoded by the locus of enterocyte effacement (LEE), and Shiga toxin. We modeled the tertiary structure of QseC's periplasmic sensing domain and aligned the sequences from 12 different species to identify the most conserved amino acids. We selected eight amino acids conserved in all of these QseC homologues. The corresponding QseC site-directed mutants were expressed and still able to autophosphorylate; however, four mutants demonstrated an increased basal level of phosphorylation. These mutants have differential flagellar, motility, LEE, and Shiga toxin expression phenotypes. We selected four mutants for more in-depth analyses and found that they differed in their ability to phosphorylate QseB, KdpE, and QseF. This suggests that these mutations in the periplasmic sensing domain affected the region downstream of the QseC signaling cascade and therefore can influence which pathway QseC regulates.IMPORTANCE In the foodborne pathogen EHEC, QseC senses AI-3, epinephrine, and norepinephrine, increases its autophosphorylation, and then transfers its phosphate to three RRs: QseB, QseF, and KdpE. QseB controls expression of flagella and motility, KdpE controls expression of the LEE region, and QseF controls the expression of Shiga toxin. This tripartite signaling pathway must be tightly controlled, given that flagella and the type three secretion system (T3SS) are energetically expensive appendages and Shiga toxin expression leads to bacterial cell lysis. Our data suggest that mutations in the periplasmic sensing loop of QseC differentially affect the expression of the three arms of this signaling cascade. This suggests that these point mutations may change QseC's phosphotransfer preferences for its RRs.

Biological Variation of Plasma and Urinary Markers of Acute Kidney Injury in Patients with Chronic Kidney Disease.

BACKGROUND: Identification of acute kidney injury (AKI) is predominantly based on changes in plasma creatinine concentration, an insensitive marker. Alternative biomarkers have been proposed. The reference change value (RCV), the point at which biomarker change can be inferred to have occurred with statistical certainty, provides an objective assessment of change in serial tests results in an individual. METHODS: In 80 patients with chronic kidney disease, weekly measurements of blood and urinary biomarker concentrations were undertaken over 6 weeks. Variability was determined and compared before and after adjustment for urinary creatinine and across subgroups stratified by level of kidney function, proteinuria, and presence or absence of diabetes. RESULTS: RCVs were determined for whole blood, plasma, and urinary neutrophil gelatinase-associated lipocalin (111%, 59%, and 693%, respectively), plasma cystatin C (14%), creatinine (17%), and urinary kidney injury molecule 1 (497%), tissue inhibitor of metalloproteinases 2 (454%), N-acetyl-ß-d-glucosaminidase (361%), interleukin-18 (819%), albumin (430%), and α1-microglobulin (216%). Blood biomarkers exhibited lower variability than urinary biomarkers. Generally, adjusting urinary biomarker concentrations for creatinine reduced (P < 0.05) within-subject biological variability (CVI). For some markers, variation differed (P < 0.05) between subgroups. CONCLUSIONS: These data can form a basis for application of these tests in clinical practice and research studies and are applicable across different levels of kidney function and proteinuria and in the presence or absence of diabetes. Most of the studied biomarkers have relatively high CVI (noise) but also have reported large concentration changes in response to renal insult (signal); thus progressive change should be detectable (high signal-to-noise ratio) when baseline data are available.

Virulence and stress-related periplasmic protein (VisP) in bacterial/host associations.

Gram-negative bacteria have an outer membrane containing LPS. LPS is constituted of an oligosaccharide portion and a lipid-A moiety that embeds this molecule within the outer membrane. LPS is a pathogen-associated molecular pattern, and several pathogens modify their lipid-A as a stealth strategy to avoid recognition by the innate immune system and gain resistance to host factors that disrupt the bacterial cell envelope. An essential feature of Salmonella enterica Typhimurium pathogenesis is its ability to replicate within vacuoles in professional macrophages. S. Typhimurium modifies its lipid-A by hydroxylation by the Fe2+/α-ketoglutarate-dependent dioxygenase enzyme (LpxO). Here, we show that a periplasmic protein of the bacterial oligonucleotide/oligosaccharide-binding fold family, herein named virulence and stress-related periplasmic protein (VisP), on binding to the sugar moiety of peptidoglycan interacts with LpxO. This interaction inhibits LpxO function, leading to decreased LpxO-dependent lipid-A modifications and increasing resistance to stressors within the vacuole environment during intramacrophage replication promoting systemic disease. Consequently, ΔvisP is avirulent in systemic murine infections, where VisP acts through LpxO. Several Gram-negative pathogens harbor both VisP and LpxO, suggesting that this VisP-LpxO mechanism of lipid-A modifications has broader implications in bacterial pathogenesis. Bacterial species devoid of LpxO (e.g., Escherichia coli) have no lipid-A phenotypes associated with the lack of VisP; however, VisP also controls LpxO-independent phenotypes. VisP and LpxO act independently in the S. Typhimurium murine colitis model, with both mutants being attenuated for diverging reasons; ΔvisP is less resistant to cationic antimicrobial peptides, whereas ΔlpxO is deficient for epithelial cell invasion. VisP converges bacterial cell wall homeostasis, stress responses, and pathogenicity.

Cell-to-cell signalling during pathogenesis.

Pathogenic bacteria produce virulence factors only when they sense they are in a location in which the energy required for pathogenesis is warranted. One environmental factor monitored by pathogens is population density, either of its own population or of the population of a host's endogenous flora. To date, four systems have been described which allow pathogens to regulate virulence genes in a population-dependent manner. These systems are found in both Gram-positive and Gram-negative cells and utilize various mechanisms to control gene regulation at a transcriptional level, but they all have one feature in common: they detect autoinducers released by cells belonging to either the pathogen's population or that of the host's flora. This article explores the role of these four signalling systems in bacterial communities and how pathogens use these systems to control genes required during host invasion and infection.

Communicating Climate Change: Lessons Learned from a Researcher-Museum Collaboration.

The need for science education and outreach is great. However, despite the ever-growing body of available scientific information, facts are often misrepresented to or misunderstood by the general public. This can result in uninformed decisions that negatively impact society at both individual and community levels. One solution to this problem is to make scientific information more available to the public through outreach programs. Most outreach programs, however, focus on health initiatives, STEM programs, or young audiences exclusively. This article describes a collaboration between the Research and Learning Center at the Fort Worth Museum of Science and History and an interdisciplinary team of researchers from the Dallas-Fort Worth (DFW) metroplex area. The collaboration was a pilot effort of a science communication fellowship and was designed to train researchers to effectively convey current science information to the public with a focus on lifelong learning. We focus on the broader idea of a university-museum collaboration that bridges the science communication gap as we outline the process of forming this collaboration, lessons we learned from the process, and directions that can support future collaborations.

Laboratory-based clinical audit as a tool for continual improvement: an example from CSF chemistry turnaround time audit in a South-African teaching hospital.

INTRODUCTION: Timeliness of laboratory results is crucial to patient care and outcome. Monitoring turnaround times (TAT), especially for emergency tests, is important to measure the effectiveness and efficiency of laboratory services. Laboratory-based clinical audits reveal opportunities for improving quality. Our aim was to identify the most critical steps causing a high TAT for cerebrospinal fluid (CSF) chemistry analysis in our laboratory. MATERIALS AND METHODS: A 6-month retrospective audit was performed. The duration of each operational phase across the laboratory work flow was examined. A process-mapping audit trail of 60 randomly selected requests with a high TAT was conducted and reasons for high TAT were tested for significance. RESULTS: A total of 1505 CSF chemistry requests were analysed. Transport of samples to the laboratory was primarily responsible for the high average TAT (median TAT = 170 minutes). Labelling accounted for most delays within the laboratory (median TAT = 71 minutes) with most delays occurring after regular work hours (P < 0.05). CSF chemistry requests without the appropriate number of CSF sample tubes were significantly associated with delays in movement of samples from the labelling area to the technologist's work station (caused by a preference for microbiological testing prior to CSF chemistry). CONCLUSION: A laboratory-based clinical audit identified sample transportation, work shift periods and use of inappropriate CSF sample tubes as drivers of high TAT for CSF chemistry in our laboratory. The results of this audit will be used to change pre-analytical practices in our laboratory with the aim of improving TAT and customer satisfaction.

Ethanolamine controls expression of genes encoding components involved in interkingdom signaling and virulence in enterohemorrhagic Escherichia coli O157:H7.

UNLABELLED: Bacterial pathogens must be able to both recognize suitable niches within the host for colonization and successfully compete with commensal flora for nutrients in order to establish infection. Ethanolamine (EA) is a major component of mammalian and bacterial membranes and is used by pathogens as a carbon and/or nitrogen source in the gastrointestinal tract. The deadly human pathogen enterohemorrhagic Escherichia coli O157:H7 (EHEC) uses EA in the intestine as a nitrogen source as a competitive advantage for colonization over the microbial flora. Here we show that EA is not only important for nitrogen metabolism but that it is also used as a signaling molecule in cell-to-cell signaling to activate virulence gene expression in EHEC. EA in concentrations that cannot promote growth as a nitrogen source can activate expression of EHEC's repertoire of virulence genes. The EutR transcription factor, known to be the receptor of EA, is only partially responsible for this regulation, suggesting that yet another EA receptor exists. This important link of EA with metabolism, cell-to-cell signaling, and pathogenesis, highlights the fact that a fundamental means of communication within microbial communities relies on energy production and processing of metabolites. Here we show for the first time that bacterial pathogens not only exploit EA as a metabolite but also coopt EA as a signaling molecule to recognize the gastrointestinal environment and promote virulence expression. IMPORTANCE: In order to successfully cause disease, a pathogen must be able to sense a host environment and modulate expression of its virulence genes as well as compete with the indigenous microbiota for nutrients. Ethanolamine (EA) is present in the large intestine due to the turnover of intestinal cells. Here, we show that the human pathogen Escherichia coli O157:H7, which causes bloody diarrhea and hemolytic-uremic syndrome, regulates virulence gene expression through EA metabolism and by responding to EA as a signal. These findings provide the first information directly linking EA with bacterial pathogenesis.