A cytoplasmic Slo3 isoform is expressed in somatic tissues

Slo3 is a pH-sensitive and weakly voltage-sensitive potassium channel that is essential for male fertility in mouse and whose expression is regarded as sperm-specific. These properties have proposed Slo3 as a candidate target for male contraceptive drugs. Nonetheless, the tissue distribution of Slo3 expression has not been rigorously studied yet. Applying computational and RT-PCR approaches, we identified expression of two short Slo3 isoforms in somatic mouse tissues such as brain, kidney and eye. These isoforms, which seem to result of transcription starting sites between exons 20 and 21, have an identical open reading frame, both encoding the terminal 381 amino acids of the cytosolic Slo3 domain. We corroborated the expression of these isoforms in mouse brain and testis by Western-blot. The complete isoform encoding the Slo3 ion channel was uniquely detected in testis, both at transcript and protein level. Although the functional role of the cytosolic Slo3 isoforms remains to be established, we propose that they may have a functional effect by modulating Slo channels trafficking and/or activity. This study confirms that expression of full-length Slo3 is sperm-specific but warns against developing contraceptive drugs targeting the C-terminal tail of Slo3 channels

Molecular control of sucrose utilization in Escherichia coli W, an efficient sucrose-utilizing strain

Sucrose is an industrially important carbon source for microbial fermentation. Sucrose utilization in Escherichia coli, however, is poorly understood, and most industrial strains cannot utilize sucrose. The roles of the chromosomally encoded sucrose catabolism (csc) genes in E. coli W were examined by knockout and overexpression experiments. At low sucrose concentrations, the csc genes are repressed and cells cannot grow. Removal of either the repressor protein (cscR) or the fructokinase (cscK) gene facilitated derepression. Furthermore, combinatorial knockout of cscR and cscK conferred an improved growth rate on low sucrose. The invertase (cscA) and sucrose transporter (cscB) genes are essential for sucrose catabolism in E. coli W, demonstrating that no other genes can provide sucrose transport or inversion activities. However, cscK is not essential for sucrose utilization. Fructose is excreted into the medium by the cscK-knockout strain in the presence of high sucrose, whereas at low sucrose (when carbon availability is limiting), fructose is utilized by the cell. Overexpression of cscA, cscAK, or cscAB could complement the W Delta cscRKAB knockout mutant or confer growth on a K-12 strain which could not naturally utilize sucrose. However, phenotypic stability and relatively good growth rates were observed in the K-12 strain only when overexpressing cscAB, and full growth rate complementation in W Delta cscRKA Balso required cscAB. Our understanding of sucrose utilization can be used to improve E. coli Wand engineer sucrose utilization in strains which do not naturally utilize sucrose, allowing substitution of sucrose for other, less desirable carbon sources in industrial fermentations

Project FIT: Rationale, design and baseline characteristics of a school- and community-based intervention to address physical activity and healthy eating among low-income elementary school children

<p>Abstract</p> <p>Background</p> <p>This paper describes Project FIT, a collaboration between the public school system, local health systems, physicians, neighborhood associations, businesses, faith-based leaders, community agencies and university researchers to develop a multi-faceted approach to promote physical activity and healthy eating toward the general goal of preventing and reducing childhood obesity among children in Grand Rapids, MI, USA.</p> <p>Methods/design</p> <p>There are four overall components to Project FIT: school, community, social marketing, and school staff wellness - all that focus on: 1) increasing access to safe and affordable physical activity and nutrition education opportunities in the schools and surrounding neighborhoods; 2) improving the affordability and availability of nutritious food in the neighborhoods surrounding the schools; 3) improving the knowledge, self-efficacy, attitudes and behaviors regarding nutrition and physical activity among school staff, parents and students; 4) impacting the 'culture' of the schools and neighborhoods to incorporate healthful values; and 5) encouraging dialogue among all community partners to leverage existing programs and introduce new ones.</p> <p>Discussion</p> <p>At baseline, there was generally low physical activity (70% do not meet recommendation of 60 minutes per day), excessive screen time (75% do not meet recommendation of < 2 hours per day), and low intake of vegetables and whole grains and high intake of sugar-sweetened beverages, French fries and chips and desserts as well as a high prevalence of overweight and obesity (48.5% including 6% with severe obesity) among low income, primarily Hispanic and African American 3^rd-5^thgrade children (n = 403).</p> <p>Trial registration</p> <p><b>ClinicalTrials.gov <a href="http://www.clinicaltrials.gov/ct2/show/NCT01385046">NCT01385046</a></b></p

Children's very low food security is associated with increased dietary intakes in energy, fat, and added sugar among Mexican-origin children (6-11 y) in Texas border Colonias

<p>Abstract</p> <p>Background</p> <p>Food insecurity among Mexican-origin and Hispanic households is a critical nutritional health issue of national importance. At the same time, nutrition-related health conditions, such as obesity and type 2 diabetes, are increasing in Mexican-origin youth. Risk factors for obesity and type 2 diabetes are more common in Mexican-origin children and include increased intakes of energy-dense and nutrient-poor foods. This study assessed the relationship between children's experience of food insecurity and nutrient intake from food and beverages among Mexican-origin children (age 6-11 y) who resided in Texas border <it>colonias</it>.</p> <p>Methods</p> <p>Baseline data from 50 Mexican-origin children were collected in the home by trained <it>promotora</it>-researchers. All survey (demographics and nine-item child food security measure) and 24-hour dietary recall data were collected in Spanish. Dietary data were collected in person on three occasions using a multiple-pass approach; nutrient intakes were calculated with NDS-R software. Separate multiple regression models were individually fitted for total energy, protein, dietary fiber, calcium, vitamin D, potassium, sodium, Vitamin C, and percentage of calories from fat and added sugars.</p> <p>Results</p> <p>Thirty-two children (64%) reported low or very low food security. Few children met the recommendations for calcium, dietary fiber, and sodium; and none for potassium or vitamin D. Weekend intake was lower than weekday for calcium, vitamin D, potassium, and vitamin C; and higher for percent of calories from fat. Three-day average dietary intakes of total calories, protein, and percent of calories from added sugars increased with declining food security status. Very low food security was associated with greater intakes of total energy, calcium, and percentage of calories from fat and added sugar.</p> <p>Conclusions</p> <p>This paper not only emphasizes the alarming rates of food insecurity for this Hispanic subgroup, but describes the associations for food insecurity and diet among this sample of Mexican-origin children. Child-reported food insecurity situations could serve as a screen for nutrition problems in children. Further, the National School Lunch and School Breakfast Programs, which play a major beneficial role in children's weekday intakes, may not be enough to keep pace with the nutritional needs of low and very low food secure Mexican-origin children.</p

Identification of calcium-binding proteins associated with the human sperm plasma membrane

<p>Abstract</p> <p>Background</p> <p>The precise composition of the human sperm plasma membrane, the molecular interactions that define domain specific functions, and the regulation of membrane associated proteins during the capacitation process, still remain to be fully understood. Here, we investigated the repertoire of calcium-regulated proteins associated with the human sperm plasma membrane.</p> <p>Methods</p> <p>Surface specific radioiodination was combined with two-dimensional gel electrophoresis, a 45Ca-overlay assay, computer assisted image analysis and mass spectrometry to identify calcium-binding proteins exposed on the human sperm surface.</p> <p>Results</p> <p>Nine acidic 45Ca-binding sperm proteins were excised from stained preparative 2D gels and identified by mass spectrometry. Five of the calcium binding proteins; HSPA2 (HSP70-1), HSPA5 (Bip), HYOU1 (ORP150), serum amyloid P-component (SAP) and protein kinase C substrate 80K-H (80K-H) were found to be accessible to Iodo-Bead catalyzed 125I-labelling on the surface of intact human sperm. Agglutination and immunofluorescence analysis confirmed that SAP is situated on the plasma membrane of intact, motile sperm as well as permeabilized cells. Western blot analysis showed increased phosphorylation of human sperm 80K-H protein following in vitro capacitation. This is the first demonstration of the 80K-H protein in a mammalian sperm.</p> <p>Conclusion</p> <p>The presence of SAP on the surface of mature sperm implies that SAP has a physiological role in reproduction, which is thought to be in the removal of spermatozoa from the female genital tract via phagocytosis. Since 80K-H is a Ca2+-sensor recently implicated in the regulation of both inositol 1,4,5-trisphosphate receptor and transient receptor potential (TRP) cation channel activities, its detection in sperm represents the first direct signaling link between PKC and store-operated calcium channels identified in human sperm.</p

The Use of Anti-VDAC2 Antibody for the Combined Assessment of Human Sperm Acrosome Integrity and Ionophore A23187-Induced Acrosome Reaction

Voltage-dependent anion channel (VDAC) is mainly located in the mitochondrial outer membrane and participates in many biological processes. In mammals, three VDAC subtypes (VDAC1, 2 and 3) have been identified. Although VDAC has been extensively studied in various tissues and cells, there is little knowledge about the distribution and function of VDAC in male mammalian reproductive system. Several studies have demonstrated that VDAC exists in mammalian spermatozoa and is implicated in spermatogenesis, sperm maturation, motility and fertilization. However, there is no knowledge about the respective localization and function of three VDAC subtypes in human spermatozoa. In this study, we focused on the presence of VDAC2 in human spermatozoa and its possible role in the acrosomal integrity and acrosome reaction using specific anti-VDAC2 monoclonal antibody for the first time. The results exhibited that native VDAC2 existed in the membrane components of human spermatozoa. The co-incubation of spermatozoa with anti-VDAC2 antibody did not affect the acrosomal integrity and acrosome reaction, but inhibited ionophore A23187-induced intracellular Ca2+ increase. Our study suggested that VDAC2 was located in the acrosomal membrane or plasma membrane of human spermatozoa, and played putative roles in sperm functions through mediating Ca2+ transmembrane transport

Genome-Wide Identification of Small RNAs in the Opportunistic Pathogen Enterococcus faecalis V583

Small RNA molecules (sRNAs) are key mediators of virulence and stress inducible gene expressions in some pathogens. In this work we identify sRNAs in the Gram positive opportunistic pathogen Enterococcus faecalis. We characterized 11 sRNAs by tiling microarray analysis, 5′ and 3′ RACE-PCR, and Northern blot analysis. Six sRNAs were specifically expressed at exponential phase, two sRNAs were observed at stationary phase, and three were detected during both phases. Searches of putative functions revealed that three of them (EFA0080_EFA0081 and EFB0062_EFB0063 on pTF1 and pTF2 plasmids, respectively, and EF0408_EF04092 located on the chromosome) are similar to antisense RNA involved in plasmid addiction modules. Moreover, EF1097_EF1098 shares strong homologies with tmRNA (bi-functional RNA acting as both a tRNA and an mRNA) and EF2205_EF2206 appears homologous to 4.5S RNA member of the Signal Recognition Particle (SRP) ribonucleoprotein complex. In addition, proteomic analysis of the ΔEF3314_EF3315 sRNA mutant suggests that it may be involved in the turnover of some abundant proteins. The expression patterns of these transcripts were evaluated by tiling array hybridizations performed with samples from cells grown under eleven different conditions some of which may be encountered during infection. Finally, distribution of these sRNAs among genome sequences of 54 E. faecalis strains was assessed. This is the first experimental genome-wide identification of sRNAs in E. faecalis and provides impetus to the understanding of gene regulation in this important human pathogen

A falling of the veils: turning points and momentous turning points in leadership and the creation of CSR

This article uses the life stories approach to leadership and leadership development. Using exploratory, qualitative data from a Forbes Global 2000 and FTSE 100 company, we discuss the role of the turning point (TP) as an important antecedent of leadership in corporate social responsibility. We argue that TPs are causally efficacious, linking them to the development of life narratives concerned with an evolving sense of personal identity. Using both a multi-disciplinary perspective and a multi-level focus on CSR leadership, we identify four narrative cases. We propose that they helped to re-define individuals’ sense of self and in some extreme cases completely transformed their self-identity as leaders of CSR. Hence we also distinguish the momentous turning point (MTP) that created a seismic shift in personality, through re-evaluation of the individuals’ personal values. We argue that whilst TPs are developmental experiences that can produce responsible leadership, the MTP changes the individuals’ personal priorities in life to produce responsible leadership that perhaps did not exist previously. Thus we appropriate Maslow’s (1976, p. 77) metaphorical phrase ‘A falling of the veils’ from his discussion of peak and desolation experiences that produce personal growth. Using a multi-disciplinary literature from social theory (Archer, 2012) moral psychology (Narvaez, 2009) and social psychology (Schwartz, 2010), we present a theoretical model that illustrates the psychological process of the (M)TP, thus contributing to the growing literature on the microfoundations of CSR

An Integrative Approach to Understanding Counterproductive Work Behavior: The Roles of Stressors, Negative Emotions, and Moral Disengagement

Several scholars have highlighted the importance of examining moral disengagement (MD) in understanding aggression and deviant conduct across different contexts. The present study investigates the role of MD as a specific social-cognitive construct that, in the organizational context, may intervene in the process leading from stressors to counterproductive work behavior (CWB). Assuming the theoretical framework of the stressor-emotion model of CWB, we hypothesized that MD mediates, at least partially, the relation between negative emotions in reaction to perceived stressors and CWB by promoting or justifying aggressive responses to frustrating situations or events. In a sample of 1,147 Italian workers, we tested a structural equations model. The results support our hypothesis: the more workers experienced negative emotions in response to stressors, the more they morally disengaged and, in turn, enacted CW

A neo-institutional perspective on ethical decision-making

Drawing on neo-institutional theory, this study aims to discern the poorly understood ethical challenges confronted by senior executives in Indian multinational corporations and identify the strategies that they utilize to overcome them. We conducted in-depth interviews with 40 senior executives in Indian multinational corporations to illustrate these challenges and strategies. By embedding our research in contextually relevant characteristics that embody the Indian environment, we identify several institutional- and managerial-level challenges faced by executives. The institutional-level challenges are interpreted as regulative, normative and cognitive shortcomings. We recommend a concerted effort at the institutional and managerial levels by identifying relevant strategies for ethical decision-making. Moreover, we proffer a multi-level model of ethical decision-making and discuss our theoretical contributions and practical implications