Bivalent complexes of PRC1 with orthologs of BRD4 and MOZ/MORF target developmental genes in Drosophila.

Regulatory decisions in Drosophila require Polycomb group (PcG) proteins to maintain the silent state and Trithorax group (TrxG) proteins to oppose silencing. Since PcG and TrxG are ubiquitous and lack apparent sequence specificity, a long-standing model is that targeting occurs via protein interactions; for instance, between repressors and PcG proteins. Instead, we found that Pc-repressive complex 1 (PRC1) purifies with coactivators Fs(1)h [female sterile (1) homeotic] and Enok/Br140 during embryogenesis. Fs(1)h is a TrxG member and the ortholog of BRD4, a bromodomain protein that binds to acetylated histones and is a key transcriptional coactivator in mammals. Enok and Br140, another bromodomain protein, are orthologous to subunits of a mammalian MOZ/MORF acetyltransferase complex. Here we confirm PRC1-Br140 and PRC1-Fs(1)h interactions and identify their genomic binding sites. PRC1-Br140 bind developmental genes in fly embryos, with analogous co-occupancy of PRC1 and a Br140 ortholog, BRD1, at bivalent loci in human embryonic stem (ES) cells. We propose that identification of PRC1-Br140 "bivalent complexes" in fly embryos supports and extends the bivalency model posited in mammalian cells, in which the coexistence of H3K4me3 and H3K27me3 at developmental promoters represents a poised transcriptional state. We further speculate that local competition between acetylation and deacetylation may play a critical role in the resolution of bivalent protein complexes during development.

A UK framework for the assessment and integration of different scientific evidence streams in chemical risk assessment.

BACKGROUND: Few methods are available for transparently combining different evidence streams for chemical risk assessment to reach an integrated conclusion on the probability of causation. Hence, the UK Committees on Toxicity (COT) and on Carcinogenicity (COC) have reviewed current practice and developed guidance on how to achieve this in a transparent manner, using graphical visualisation. METHODS/APPROACH: All lines of evidence, including toxicological, epidemiological, new approach methodologies, and mode of action should be considered, taking account of their strengths/weaknesses in their relative weighting towards a conclusion on the probability of causation. A qualitative estimate of the probability of causation is plotted for each line of evidence and a combined estimate provided. DISCUSSION/CONCLUSIONS: Guidance is provided on integration of multiple lines of evidence for causation, based on current best practice. Qualitative estimates of probability for each line of evidence are plotted graphically. This ensures a deliberative, consensus conclusion on likelihood of causation is reached. It also ensures clear communication of the influence of the different lines of evidence on the overall conclusion on causality. Issues on which advice from the respective Committees is sought varies considerably, hence the guidance is designed to be sufficiently flexible to meet this need.

When I can be my whole authentic self, I feel safe and know that I belong: a photovoice study exploring what culturally safe pregnancy care is to Karen women of refugee background in Victoria, Australia.

OBJECTIVES: Inequitable pregnancy care experiences and outcomes disproportionately affect refugee background women in Australia. Culturally safe care is essential for achieving health equity, however, cultural safety can only be determined by the person receiving care. To our knowledge, women of refugee background in Australia are yet to be asked what culturally safe pregnancy care is to them. Specifically, this study aimed to explore what culturally safe pregnancy care is to Karen women (from Burma) of refugee background. DESIGN: A photovoice study founded on community-based participatory research principles was undertaken with a Karen community of refugee background living in Victoria, Australia. A community advisory group was established, guiding study design and conduct. Five S'gaw Karen-speaking women with experience of pregnancy care in Australia were invited to take photos within their community. Participants shared their photos and stories with each other in four online discussion groups. RESULTS: Reflexive thematic analysis guided by a critical constructionist lens developed three themes: Building foundations for belonging; cultivating reciprocal curiosity; and storytelling as an expression of self and shared power. These themes sit within the overarching theme When I can be my whole authentic self, I feel safe and know that I belong. CONCLUSION: When Karen women can embrace their cultural and spiritual identity without fear of discrimination, including racism, culturally safe pregnancy care is possible. This study contributes to the design and delivery of maternity services by providing insights that can enhance equitable and culturally safe pregnancy care for Karen women of refugee background.

Factors associated with nursing students' attitudes toward older people: A scoping review.

Nursing students rate geriatric nursing poorly in career preferences, but aging populations mean more older people require access to health care. Negative attitudes held by nursing students can lead to ageism affecting the quality of care provided. The purpose of this scoping review is to summarize research findings in the published literature relating to factors associated with nursing students' attitudes toward older people, and the tools used to measure these attitudes. The Joanna Briggs Institute guide for conducting a scoping review was used. Eleven databases and search engines were searched for international peer reviewed research articles published in English between January 2000 and February 2021. Sixteen articles were included in the review. This review highlights areas for affirmative action to improve undergraduate nursing students' attitudes toward older people to prepare them to work effectively in future health care systems. Positive attitudes were associated with: senior years of study; professional values (caring, professionalism, trust); education regarding care of older adults; knowledge about aging; contact with older family members; comfort communicating with older people; and willingness to work with older people following graduation. It also identified the need for a current, nursing-specific measure of attitudes toward older people.

Role of Polyamine-Induced Dimerization of Antizyme in Its Cellular Functions.

The polyamines, spermine (Spm) and spermidine (Spd), are important for cell growth and function. Their homeostasis is strictly controlled, and a key downregulator of the polyamine pool is the polyamine-inducible protein, antizyme 1 (OAZ1). OAZ1 inhibits polyamine uptake and targets ornithine decarboxylase (ODC), the rate-limiting enzyme of polyamine biosynthesis, for proteasomal degradation. Here we report, for the first time, that polyamines induce dimerization of mouse recombinant full-length OAZ1, forming an (OAZ1)2-Polyamine complex. Dimerization could be modulated by functionally active C-methylated spermidine mimetics (MeSpds) by changing the position of the methyl group along the Spd backbone-2-MeSpd was a poor inducer as opposed to 1-MeSpd, 3-MeSpd, and Spd, which were good inducers. Importantly, the ability of compounds to inhibit polyamine uptake correlated with the efficiency of the (OAZ1)2-Polyamine complex formation. Thus, the (OAZ1)2-Polyamine complex may be needed to inhibit polyamine uptake. The efficiency of polyamine-induced ribosomal +1 frameshifting of OAZ1 mRNA could also be differentially modulated by MeSpds-2-MeSpd was a poor inducer of OAZ1 biosynthesis and hence a poor downregulator of ODC activity unlike the other MeSpds. These findings offer new insight into the OAZ1-mediated regulation of polyamine homeostasis and provide the chemical tools to study it.

Mutations in the insulator protein Suppressor of Hairy wing induce genome instability.

Insulator proteins orchestrate the three-dimensional organization of the genome. Insulators function by facilitating communications between regulatory sequences and gene promoters, allowing accurate gene transcription regulation during embryo development and cell differentiation. However, the role of insulator proteins beyond genome organization and transcription regulation remains unclear. Suppressor of Hairy wing [Su(Hw)] is a Drosophila insulator protein that plays an important function in female oogenesis. Here we find that su(Hw) has an unsuspected role in genome stability during cell differentiation. We show that su(Hw) mutant developing egg chambers have poorly formed microtubule organization centers (MTOCs) in the germarium and display mislocalization of the anterior/posterior axis specification factor gurken in later oogenesis stages. Additionally, eggshells from partially rescued su(Hw) mutant female germline exhibit dorsoventral patterning defects. These phenotypes are very similar to phenotypes found in the important class of spindle mutants or in piRNA pathway mutants in Drosophila, in which defects generally result from the failure of germ cells to repair DNA damage. Similarities between mutations in su(Hw) and spindle and piRNA mutants are further supported by an excess of DNA damage in nurse cells, and because Gurken localization defects are partially rescued by mutations in the ATR (mei-41) and Chk1 (grapes) DNA damage response genes. Finally, we also show that su(Hw) mutants produce an elevated number of chromosome breaks in dividing neuroblasts from larval brains. Together, these findings suggest that Su(Hw) is necessary for the maintenance of genome integrity during Drosophila development, in both germline and dividing somatic cells.

XIAP monoubiquitylates Groucho/TLE to promote canonical Wnt signaling.

A key event in Wnt signaling is conversion of TCF/Lef from a transcriptional repressor to an activator, yet how this switch occurs is not well understood. Here, we report an unanticipated role for X-linked inhibitor of apoptosis (XIAP) in regulating this critical Wnt signaling event that is independent of its antiapoptotic function. We identified DIAP1 as a positive regulator of Wingless signaling in a Drosophila S2 cell-based RNAi screen. XIAP, its vertebrate homolog, is similarly required for Wnt signaling in cultured mammalian cells and in Xenopus embryos, indicating evolutionary conservation of function. Upon Wnt pathway activation, XIAP is recruited to TCF/Lef where it monoubiquitylates Groucho (Gro)/TLE. This modification decreases affinity of Gro/TLE for TCF/Lef. Our data reveal a transcriptional switch involving XIAP-mediated ubiquitylation of Gro/TLE that facilitates its removal from TCF/Lef, thus allowing ß-catenin-TCF/Lef complex assembly and initiation of a Wnt-specific transcriptional program.

Repurposing of idebenone as a potential anti-cancer agent.

Glioblastoma (GB) represents the most common and aggressive form of malignant primary brain tumour associated with high rates of morbidity and mortality. In the present study, we considered the potential use of idebenone (IDE), a Coenzyme Q10 analogue, as a novel chemotherapeutic agent for GB. On two GB cell lines, U373MG and U87MG, IDE decreased the viable cell number and enhanced the cytotoxic effects of two known anti-proliferative agents: temozolomide and oxaliplatin. IDE also affected the clonogenic and migratory capacity of both GB cell lines, at 25 and 50 µM, a concentration equivalent to that transiently reached in plasma after oral intake that is deemed safe for humans. p21 protein expression was decreased in both cell lines, indicating that IDE likely exerts its effects through cell cycle dysregulation, and this was confirmed in U373MG cells only by flow cytometric cell cycle analysis which showed S-phase arrest. Caspase-3 protein expression was also significantly decreased in U373MG cells indicating IDE-induced apoptosis that was confirmed by flow cytometric Annexin V/propidium iodide staining. No major decrease in caspase-3 expression was observed in U87MG cells nor apoptosis as observed by flow cytometry analysis. Overall, the present study demonstrates that IDE has potential as an anti-proliferative agent for GB by interfering with several features of glioma pathogenesis such as proliferation and migration, and hence might be a drug that could be repurposed for aiding cancer treatments. Furthermore, the synergistic combinations of IDE with other agents aimed at different pathways involved in this type of cancer are promising.

Who decides to have sex? Exploring the perceptions of Timorese women and men through a reproductive justice lens.

Despite national policies to support sexual rights, Timorese women are constrained when making sexual and reproductive health decisions. Contextual understanding of sexual decision making is vital for effective engagement by sexual and reproductive health service providers with communities. An intersectional reproductive justice approach broadens the sexual rights lens allowing for an examination of multi-system factors impacting on sexual rights and health. Using the Matrix of Domination as a conceptual framework, we explored Timorese perceptions around decisions to have sex, and examined intersecting systems of oppression impacting on these decisions. Our study adopted a critical medical anthropological approach using ethnographic methods. A decolonising methodology aimed to make Timorese worldviews central to the analysis. Nine focus group discussions with 80 men and 17 individual reproductive history interviews with women were held in 4 of Timor-Leste's 13 municipalities during October 2015. Findings suggest that decisions to have sex are framed in terms of wishes and rights; however, it was the perceived entitlements of men that were prioritised and predominantly men who made these decisions. Violence, coercion and unwanted pregnancies were linked to decisions about sex, and identified as potential consequences for women, impacting on women's health and sexual rights.

Condensin II subunit NCAPH2 associates with shelterin protein TRF1 and is required for telomere stability.

Condensin II subunits are known to be expressed and localized to interphase nuclei of eukaryotic cells. Although some studies have shown that condensin II likely exerts axial compaction forces, organizes chromosome territories, and has possible transcriptional modulatory functions, the full range of condensin II interphase activities are not known. In particular, it is not known if condensin II interphase activities are generally genome-wide or if they have additional local activities unique to specific chromosomal structures such as telomeres. Here, we find that NCAPH2 interacts with TRF1 and these two proteins co-localize at telomeres. Depletion of NCAPH2 leads to ATR-dependent accumulation of 53BP1 and γH2AX DNA damage foci, including damage specific to telomeres. Furthermore, depletion of NCAPH2 results in a fragile telomere phenotype and apparent sister-telomere fusions only days after NCAPH2 depletion. Taken together these observations suggest that NCAPH2 promotes telomere stability, possibly through a direct interaction with the TRF1 shelterin component, and prevents telomere dysfunction resulting from impaired DNA replication. Because proper telomere function is essential for chromosome integrity these observations reveal a previously unappreciated function for NCAPH2 in ensuring genome and telomere stability.

Community Coalitions for Change and the Policy, Systems, and Environment Model: A Community-Based Participatory Approach to Addressing Obesity in Rural Tennessee.

Four rural counties in Tennessee adopted the policy, systems, and environment (PSE) approach to address the obesity epidemic in their communities. The community-based participatory initiative, Community Coalitions for Change (C3), was embraced by 67,400 community members and 67 organizations. During year 1, coalition members discussed a need to return to long-held traditions of collective community engagement and action to address rural obesity rates. In response, C3 established 25 community gardens and supported 10 existing gardens, resulting in 8,300 community members who received garden produce. Sites began with an average number of 11 physical activity resources, which increased by year 3 to an average of 13 resources as a result of C3 activities. Overall, 61% (248 of 405) of survey respondents participating in direct education programs reported being more physically active as a result of participating in the programs, 59% (117 of 199) reported eating more fruit, and 66% (131 of 199) reported eating more vegetables. Implications for public health include timing and aligning obesity prevention activities with ongoing initiatives that are working toward similar goals.

What influences a woman's decision to access contraception in Timor-Leste? Perceptions from Timorese women and men.

Timor-Leste's Maternal Mortality Ratio remains one of the highest in Asia. There is ample evidence that maternal deaths may be reduced substantially through the provision of good-quality modern methods of contraception. Many Timorese women wish to stop or delay having children. However, even when health services make contraception available, it does not mean that people will use it. Collaborating with Marie Stopes Timor-Leste, this qualitative research project used decolonising methodology to explore perceived influences contributing to contraceptive choices, and gain insight into how women's decisions to access contraception in Timor-Leste occur. Over two fieldwork periods (2013 and 2015), we used focus group discussions and structured interviews to speak with 68 women and 80 men, aged 18-49 years, across four districts of Timor-Leste. Findings demonstrate that the decision to access contraception is often contentious and complicated. These tensions echo concerns and ambiguities contained within global and national reproductive health policy. Overwhelmingly, participants emphasised that despite her wishes, a woman can only rarely exercise her right to access contraception freely and independently. She is most often constrained by family, cultural, traditional and educational influences.

Body Mapping to Explore Reproductive Ethno-Physiological Beliefs and Knowledge of Contraception in Timor-Leste.

Maternal mortality remains a significant public health challenge for Timor-Leste. Although access to quality family planning measures may greatly reduce such deaths, consideration of indigenous perceptions, and how they influence reproductive health decision-making and behavior, is crucial if health services are to provide initiatives that are accepted and helpful in improving reproductive health outcomes. We aimed to demonstrate that body mapping is an effective method to traverse language and culture to gain emic insights and indigenous worldviews. The authors' two qualitative research projects (2013 and 2015) used a decolonizing methodology in four districts of Timor-Leste, body mapping with 67 men and 40 women to illuminate ethno-physiology and indigenous beliefs about conception, reproduction, and contraception. Body mapping provided a beneficial conduit for identifying established indigenous reproductive perceptions, understandings, and vocabulary, plus fears surrounding contraception. This may inform health service provision and engagement, ultimately improving the reproductive health of community members.

TRIP/NOPO E3 ubiquitin ligase promotes ubiquitylation of DNA polymerase η.

We previously identified a Drosophila maternal effect-lethal mutant named 'no poles' (nopo). Embryos from nopo females undergo mitotic arrest with barrel-shaped, acentrosomal spindles during the rapid cycles of syncytial embryogenesis because of activation of a Chk2-mediated DNA checkpoint. NOPO is the Drosophila homolog of human TNF receptor associated factor (TRAF)-interacting protein (TRIP), which has been implicated in TNF signaling. NOPO and TRIP contain RING domains closely resembling those of known E3 ubiquitin ligases. We herein sought to elucidate the mechanism by which TRIP/NOPO promotes genomic stability by performing a yeast two-hybrid screen to identify potential substrates/interactors. We identified members of the Y-family of DNA polymerases that facilitate replicative bypass of damaged DNA (translesion synthesis) as TRIP interactors. We show that TRIP and NOPO co-immunoprecipitate with human and Drosophila Polη, respectively, from cultured cells. We generated a null mutation in Drosophila Polη (dPolη) and found that dPolη-derived embryos have increased sensitivity to ultraviolet irradiation and exhibit nopo-like mitotic spindle defects. dPolη and nopo interact genetically in that overexpression of dPolη in hypomorphic nopo-derived embryos suppresses nopo phenotypes. We observed enhanced ubiquitylation of Polη by TRIP and NOPO E3 ligases in human cells and Drosophila embryos, respectively, and show that TRIP promotes hPolη localization to nuclear foci in human cells. We present a model in which TRIP/NOPO ubiquitylates Polη to positively regulate its activity in translesion synthesis.

Decreased sensitivity to aspirin is associated with altered polyamine metabolism in human prostate cancer cells.

Aspirin is a well-known analgesic, anti-inflammatory and antipyretic drug and is recognised as a chemopreventative agent in cardiovascular disease and, more recently, in colorectal cancer. Although several studies indicate that aspirin is capable of reducing the risk of developing cancers, there is a lack of convincing evidence that aspirin can prevent prostate cancer in man. In this study, aspirin was shown to be an effective inhibitor of the growth of human prostate cancer cells. In order to investigate the link between polyamine catabolism and the effects of aspirin we used a "Tet off" system that induced the activity of spermidine/spermine N (1)-acetyltransferase (SSAT) in human prostate cancer cells (LNCap). Treatment with aspirin was found to decrease induced SSAT activity in these cells. A negative correlation was observed between increased polyamine catabolism via increased SSAT activity and the sensitivity to aspirin. In the presence of increased SSAT activity high amounts of N (1)-acetylspermidine and putrescine were observed. These cells were also found to grow more slowly than the non-induced cells. The results indicate that SSAT and its related polyamine metabolism may play a key role in sensitivity of cancer cells to aspirin and possibly other NSAIDs and this may have implications for the development of novel chemopreventative agents.

The challenges for cancer chemoprevention.

The incidence of cancer is rising in parallel with an ageing populous thus increasing the strain on both treatment options and budgets for healthcare providers worldwide. New cancer therapies are being developed but at what cost? The new treatments are expensive and poor survival rates still exist for some cancers. What is needed now is to prevent or at least limit the disease occurring in the first place. This review evaluates the current situation and the progress in upcoming strategies as well as suggesting some areas for further research within the increasingly important field of cancer chemoprevention. The key principles of cancer chemoprevention are discussed and areas for improvement highlighted. Despite significant progress, chemoprevention has not been widely adopted. Cancer chemoprevention has many challenges to face but this only emphasises the size of the task. These hurdles include a lack of awareness of the benefits, a lack of interest and a lack of investment in taking prevention forward. Despite the huge potential importance of cancer prevention and clinical success stories such as the well-publicised HPV vaccine, the challenges remain significant. With cancer and its treatment being a global issue, the opportunities offered by chemoprevention must be re-evaluated and uptake of chemoprevention actively encouraged. If chemoprevention is to be adopted successfully, a holistic approach is required. This approach will involve multidisciplinary teams of healthcare providers and scientists with the big challenge particularly for medicinal chemists being to design and synthesise the ideal chemopreventative agent.

A role for antizyme inhibitor in cell proliferation.

The polyamines are important for a variety of cellular functions, including cell growth. Their intracellular concentrations are controlled by a complex network of regulatory mechanisms, in which antizyme (Az) has a key role. Az reduces the cellular polyamine content by down-regulating both the enzyme catalysing polyamine biosynthesis, ornithine decarboxylase (ODC), and the uptake of polyamines. The activity of Az is repressed by the binding of a protein, named Az inhibitor (AzI), which is an enzymatically inactive homologue of ODC. Two forms of AzI have been described: AzI1, which is ubiquitous, and AzI2 which is expressed in brain and testis. In the present study, we have investigated the role of AzI1 in polyamine homeostasis and cell proliferation in breast cancer cells. The results obtained showed that the cellular content of AzI increased transiently after induction of cell proliferation by diluting cells in fresh medium. Inhibition of polyamine biosynthesis induced an even larger increase in the cellular AzI content, which remained significantly elevated during the 7-day experimental period. However, this increase was not a consequence of changes in cell cycle progression, as demonstrated by flow cytometry. Instead, the increase appeared to correlate with the cellular depletion of polyamines. Moreover, induced overexpression of AzI resulted in an increased cell proliferation with a concomitant increase in ODC activity and putrescine content. During mitosis, AzI1 was localised in a pattern that resembled that of the two centrosomes, confirming earlier observations. Taken together, the results indicate that AzI fulfils an essential regulatory function in polyamine homeostasis and cell proliferation.

The relationship between the nursing environment and delivering culturally sensitive perinatal hospice care.

BACKGROUND: Wide variations exist among perinatal hospices, and barriers to perinatal palliative care exist at the healthcare level. Research in the area of culturally sensitive perinatal palliative care has been scarce, a gap which this study addresses. OBJECTIVE: To evaluate the relationship between the nurse work environment and the delivery of culturally sensitive perinatal hospice care. METHOD: This retrospective, correlational study used data from the National Home and Hospice Care Survey, which includes a nationally representative sample of hospice care providers. A multivariate logistic regression model was used to estimate the relationship between the delivery of culturally sensitive care and the nurse work environment. RESULTS: Accreditation, teaching status, and baccalaureate-prepared registered nurse staff had an impact on the provision of culturally sensitive perinatal care Conclusions: The hospice and nursing unit environments, specifically in regards to education and technology, may be important contributors to the delivery of culturally sensitive care.

Polyamines and membrane transporters.

In recent years, our understanding of the importance of membrane transporters (MTs) in the disposition of and response to drugs has increased significantly. MTs are proteins that regulate the transport of endogenous molecules and xenobiotics across the cell membrane. In mammals, two super-families have been identified: ATP-binding cassette (ABC) and solute carrier (SLC) transporters. There is evidence that MTs might mediate polyamines (PA) transport. PA are ubiquitous polycations which are found in all living cells. In mammalian cells, three major PA are synthesised: putrescine, spermidine and spermine; whilst the decarboxylated arginine (agmatine) is not produced by mammals but is synthesised by plants and bacteria. In addition, research in the PA field suggests that PA are transported into cells via a specific transporter, the polyamine transport system(s) (PTS). Although the PTS has not been fully defined, there is evidence that some of the known MTs might be involved in PA transport. In this mini review, eight SLC transporters will be reviewed and their potential to mediate PA transport in human cells discussed. These transporters are SLC22A1, SLC22A2, SLC22A3, SLC47A1, SLC7A1, SLC3A2, SLC12A8A, and SLC22A16. Preliminary data from our laboratory have revealed that SLC22A1 might be involved in the PA uptake; in addition to one member of ABC superfamily (MDR1 protein) might also mediate the efflux of polyamine like molecules.