The Relationship Development and Learning Organization Dimensions.

This research examined the relationship among learning organization dimensions, leadership development, employee development, and their interactions with two demographic variables (gender and ethnicity) in the context of libraries. The researchers conducted a multivariate analysis of the variance to assess the differences by leadership training groups (low training hours vs. high training hours), or by gender; and by workplace training groups (low vs. high), or by ethnicity (white vs. all others) on a linear combination of the seven dimensions of the learning organization. A conclusive summary is provided along with contributive discussion. Implications and contributions to librarians are discussed in addition to future research recommendations. Also included are conclusive final thoughts accompanied by the limitations of this research

THE ROLE OF NRF2 IN PREVENTING OXIDATIVE/ELECTROPHILIC STRESS-INDUCED LIVER INJURY

Redox maintenance is critical for all biological species. Amplification of mechanisms that reduces oxidative/electrophilic stress promotes health and extends life. Nuclear factor, erythroid derived 2, like 2 (Nrf2) is a master regulator of biochemical mechanisms that respond to oxidative/electrophilic stress. Under basal conditions, Nrf2 is held in an inactive state in the cytoplasm by binding to the cytoskeletal anchoring protein Kelch-like ECH-associated protein 1 (Keap1). Upon generation of oxidative/electrophilic stress, Nrf2 is released from Keap1 and translocates to the nucleus, where it promotes transcription of a battery of cytoprotective genes. The antioxidative role of Nrf2 has been extensively studied for more than ten years, but the global Nrf2 target genes in liver still remain unknown. The present dissertation utilizes a Nrf2 "gene dose-response" model to genetically modulate the levels of Nrf2 in mouse liver, where the transcription profiles in livers of mice with graded Nrf2 activation were correlated with activation of Nrf2-target genes. Thus, the Nrf2-target genes in mouse liver were investigated systematically. Pathway analyses indicate that genes induced by Nrf2 are involved in glutathione synthesis, oxidation/reduction using NADPH as the co-factor, and xenobiotic metabolism. Moreover, mRNA of genes involved in the pentose phosphate pathway and malic enzyme levels had a clear dose-dependent correlation to active levels of Nrf2, indicating that Nrf2 promotes NADPH generation. Among genes suppressed by Nrf2, the majority are involved in lipid synthesis and fatty-acid desaturation. Thus, Nrf2 promotes generation of NADPH, and reduces fatty acid synthesis and desaturation, contributing factors towards protecting liver against environmental oxidative/electrophilic stress. The mRNA abundance of 124 drug processing genes in the Nrf2 "gene dose-response" model was also determined in this dissertation. The results indicate that Nrf2 facilitates electrophile detoxification through inducing non P-450 phase-I enzymes that reduce electrophiles, Gsts that conjugate electrophiles, and efflux transporters that excrete electrophile-GSH conjugates out of cells. In addition to the assessment of the effect of Nrf2 on the global gene transcription profiles in mouse liver, the function of Nrf2 in vivo was examined by testing whether Nrf2 activation protects against chemical-induced oxidative stress and subsequent liver injury in mice. Oxidative stress and lipid accumulation play important roles in ethanol-induced liver injury. Ethanol increased serum ALT and LDH activities in Nrf2-null mice and wild-type mice, but not in Nrf2-enhanced mice, indicating that Nrf2-enhanced mice are resistant to ethanol toxicity. Ethanol increased free fatty acids in livers of Nrf2-null mice, and this increase was blunted in Nrf2-enhanced mice. Mechanistic studies show that Nrf2 prevents ethanol-induced oxidative stress through inducing cytoprotective genes including Nqo1 and Gclc, and prevents accumulation of free fatty acids in liver by suppressing the Srebp1 pathway. Oxidative stress also plays an important role in cadmium-induced liver injury. Nrf2-null mice are susceptible, whereas Nrf2-enhanced mice are resistant to cadmium-induced acute liver injury. Gclc, Gpx2, and Srxn-1, genes that are involved in GSH synthesis and reducing oxidative stress, were only induced in Nrf2-enhanced mice, but not in Nrf2-null mice. Surprisingly, metallothioneins, cysteine-rich proteins that scavenge cadmium to prevent toxicity, were induced markedly in both Nrf2-null and Nrf2-enhanced mice. Thus, there are at least two distinct pathways to protect cadmium-induced toxicity: Nrf2-dependent induction of antioxidative genes and Nrf2-independent induction of metallothioneins. To develop effective and potent Nrf2 activators, a library of synthetic and natural existing compounds was screened to test their efficacy and potency to activate Nrf2. After screening 47,000 compounds, 238 compounds (0.5%) had comparable or better efficacy to activate Nrf2 than tertiary butylhydroquinone (tBHQ), the prototypical Nrf2 activator. Among these 238 compounds, 19 compounds produce more induction of Nrf2 than 2-cyano-3,12-dioxooleana-1,9-dien-28-imidazolide (CDDO-Im), the most effective and potent Nrf2 activator known. However, none of the tested compounds were more potent in activating Nrf2 than CDDO-Im. In addition, chemical structural relationship analysis of these 238 compounds showed enrichment of four chemical scaffolds (diaryl amides and diaryl ureas, oxazoles and thiazoles, pyranones and thiapyranones, and pyridinones and pyridazinones). The top 30 compounds were screened in Hepa1c1c7 cells to increase Nqo1 mRNA, the prototypical Nrf2 target gene, and 17 of the 30 most active hits also increased Nqo1 mRNA in the cell line in a concentration-dependent manner. In addition to synthetic compounds, 54 natural compounds, known antioxidants through activating Nrf2, were tested utilizing the same screening system (AREc32 cells). Andrographolide had the highest efficacy, followed by trans-chalcone, sulforaphane, curcumin, flavone, kahweol, and carnosol, which were all more potent and effective than tBHQ. None of the natural compounds were more potent than CDDO-Im. In conclusion, Nrf2-target genes are involved in NADPH generation, NADPH-facilitated oxidative stress reduction, and detoxification and excretion of electrophiles. Nrf2 activation protects against ethanol-, cadmium-, and diquat-induced liver oxidative stress and liver injury in mice. Lastly, a few synthetic and natural existing compounds were shown to be effective in activating the Keap1-Nrf2-ARE pathway

Two Community Collaborations with Sexual Minority Women’s NGOs in Shanghai & Hong Kong

Based on research with sexual minority communities in the United States, Connie Chan, professor of public policy and public affairs, conducted comparative research with community groups in Hong Kong and Shanghai, China. She provided capacity building training and resources directly to the organization which provides outreach and service to sexual minority women and girls in Shanghai, China. Professor Chan also supported Queer Sisters – an NGO that provides advocacy and community outreach to sexual minority girls and women in Hong Kong – by co-creating a needs assessment survey and helping them to interview their membership in Hong Kong. Connie Chan collaborated with these NGOs to help produce an outreach publication and website. She also trained community members to conduct surveys and questionnaires to gather data for their reports and assisted the organizations in building capacity for funding and organizational support. Chan and her students continue to provide assistance to the group through Skype and email communication

Auxin and tryptophan homeostasis are facilitated by the ISS1/VAS1 aromatic aminotransferase in arabidopsis

Indole-3-acetic acid (IAA) plays a critical role in regulating numerous aspects of plant growth and development. While there is much genetic support for tryptophan-dependent (Trp-D) IAA synthesis pathways, there is little genetic evidence for tryptophan-independent (Trp-I) IAA synthesis pathways. Using Arabidopsis, we identified two mutant alleles of ISS1 ( I: ndole S: evere S: ensitive) that display indole-dependent IAA overproduction phenotypes including leaf epinasty and adventitious rooting. Stable isotope labeling showed that iss1, but not WT, uses primarily Trp-I IAA synthesis when grown on indole-supplemented medium. In contrast, both iss1 and WT use primarily Trp-D IAA synthesis when grown on unsupplemented medium. iss1 seedlings produce 8-fold higher levels of IAA when grown on indole and surprisingly have a 174-fold increase in Trp. These findings indicate that the iss1 mutant's increase in Trp-I IAA synthesis is due to a loss of Trp catabolism. ISS1 was identified as At1g80360, a predicted aromatic aminotransferase, and in vitro and in vivo analysis confirmed this activity. At1g80360 was previously shown to primarily carry out the conversion of indole-3-pyruvic acid to Trp as an IAA homeostatic mechanism in young seedlings. Our results suggest that in addition to this activity, in more mature plants ISS1 has a role in Trp catabolism and possibly in the metabolism of other aromatic amino acids. We postulate that this loss of Trp catabolism impacts the use of Trp-D and/or Trp-I IAA synthesis pathways.T32 AR059033 - NIAMS NIH HH

Evaluation of normalization methods for cDNA microarray data by k-NN classification

BACKGROUND: Non-biological factors give rise to unwanted variations in cDNA microarray data. There are many normalization methods designed to remove such variations. However, to date there have been few published systematic evaluations of these techniques for removing variations arising from dye biases in the context of downstream, higher-order analytical tasks such as classification. RESULTS: Ten location normalization methods that adjust spatial- and/or intensity-dependent dye biases, and three scale methods that adjust scale differences were applied, individually and in combination, to five distinct, published, cancer biology-related cDNA microarray data sets. Leave-one-out cross-validation (LOOCV) classification error was employed as the quantitative end-point for assessing the effectiveness of a normalization method. In particular, a known classifier, k-nearest neighbor (k-NN), was estimated from data normalized using a given technique, and the LOOCV error rate of the ensuing model was computed. We found that k-NN classifiers are sensitive to dye biases in the data. Using NONRM and GMEDIAN as baseline methods, our results show that single-bias-removal techniques which remove either spatial-dependent dye bias (referred later as spatial effect) or intensity-dependent dye bias (referred later as intensity effect) moderately reduce LOOCV classification errors; whereas double-bias-removal techniques which remove both spatial- and intensity effect reduce LOOCV classification errors even further. Of the 41 different strategies examined, three two-step processes, IGLOESS-SLFILTERW7, ISTSPLINE-SLLOESS and IGLOESS-SLLOESS, all of which removed intensity effect globally and spatial effect locally, appear to reduce LOOCV classification errors most consistently and effectively across all data sets. We also found that the investigated scale normalization methods do not reduce LOOCV classification error. CONCLUSION: Using LOOCV error of k-NNs as the evaluation criterion, three double-bias-removal normalization strategies, IGLOESS-SLFILTERW7, ISTSPLINE-SLLOESS and IGLOESS-SLLOESS, outperform other strategies for removing spatial effect, intensity effect and scale differences from cDNA microarray data. The apparent sensitivity of k-NN LOOCV classification error to dye biases suggests that this criterion provides an informative measure for evaluating normalization methods. All the computational tools used in this study were implemented using the R language for statistical computing and graphics

Implementation of a High-Throughput Screen for Identifying Small Molecules to Activate the Keap1-Nrf2-ARE Pathway

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that induces a battery of cytoprotective genes involved in antioxidant defense through binding to Antioxidant Response Elements (ARE) located in the promoter regions of these genes. To identify Nrf2 activators for the treatment of oxidative/electrophilic stress-induced diseases, the present study developed a high-throughput assay to evaluate Nrf2 activation using AREc32 cells that contain a luciferase gene under the control of ARE promoters. Of the 47,000 compounds screened, 238 (top 0.5% hits) of the chemicals increased the luminescent signal more than 14.4-fold and were re-tested at eleven concentrations in a range of 0.01–30 µM. Of these 238 compounds, 231 (96%) increased the luminescence signal in a concentration-dependent manner. Chemical structure relationship analysis of these 231 compounds indicated enrichment of four chemical scaffolds (diaryl amides and diaryl ureas, oxazoles and thiazoles, pyranones and thiapyranones, and pyridinones and pyridazinones). In addition, 30 of these 231 compounds were highly effective and/or potent in activating Nrf2, with a greater than 80-fold increase in luminescence, or an EC50 lower than 1.6 µM. These top 30 compounds were also screened in Hepa1c1c7 cells for an increase in Nqo1 mRNA, the prototypical Nrf2-target gene. Of these 30 compounds, 17 increased Nqo1 mRNA in a concentration-dependent manner. In conclusion, the present study documents the development, implementation, and validation of a high-throughput screen to identify activators of the Keap1-Nrf2-ARE pathway. Results from this screening identified Nrf2 activators, and provide novel insights into chemical scaffolds that might prevent oxidative/electrophilic stress-induced toxicity and carcinogenesis.Funding: The present study was funded by United States National Institutes of Health grant DK081461. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Human Tear Fluid Reduces Culturability of Contact Lens-Associated Pseudomonas aeruginosa Biofilms but Induces Expression of the Virulence-Associated Type III Secretion System

Purpose The type III secretion system (T3SS) is a significant virulence determinant for Pseudomonas aeruginosa. Using a rodent model, we found that contact lens(CL)-related corneal infections were associated with lens surface biofilms. Here, we studied the impact of human tear fluid on CL-associated biofilm growth and T3SS expression. Methods P. aeruginosa biofilms were formed on contact lenses for up to 7 days with or without human tear fluid, then exposed to tear fluid for 5 or 24 h. Biofilms were imaged using confocal microscopy. Bacterial culturability was quantified by viable counts, and T3SS gene expression measured by RT-qPCR. Controls included trypticase soy broth, PBS and planktonic bacteria. Results With or without tear fluid, biofilms grew to ∼108 CFU viable bacteria by 24 h. Exposing biofilms to tear fluid after they had formed without it on lenses reduced bacterial culturability ∼180-fold (P\u3c.001). CL growth increased T3SS gene expression versus planktonic bacteria [5.46 ± 0.24-fold for T3SS transcriptional activitor exsA (P=.02), and 3.76 ± 0.36-fold for T3SS effector toxin exoS(P=.01)]. Tear fluid further enhanced exsA and exoS expression in CL-grown biofilms, but not planktonic bacteria, by 2.09 ± 0.38-fold (P=.04) and 1.89 ± 0.26-fold (P\u3c.001), respectively. Conclusions Considering the pivitol role of the T3SS in P. aeruginosa infections, its induction in CL-grown P. aeruginosa biofilms by tear fluid might contribute to the pathogenesis of CL-related P. aeruginosa keratitis

Vacuolin-1 potently and reversibly inhibits autophagosome-lysosome fusion by activating RAB5A

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