The Developmental and Adaptive role of Mitogen Activated Protein Kinase Pathways During Preimplantation Development

The preimplantation period of development represents the highest interval of embryonic loss throughout pregnancy. It is therefore imperative that we elucidate the mechanisms involved in regulating preimplantation embryonic responses to stress and that govern development. The MAPK pathways are involved in both responding to environmental stress and regulation of development throughout embryogenesis, and are therefore good candidates to study the mechanisms involved in preimplantation embryonic adaptation to stress and development. The preimplantation embryo culminates in the development of a fluid filled structure called the blastocyst. It is at this stage the first differentiation events occur and the trophectoderm (TE), which will go on to form the embryonic portion of the placenta, develops. The p38 MAPK is required for embryo development to proceed beyond the 8-16 cell stage as well to play an adaptive role in regulating embryonic response to culture stress. My hypothesis is that the MAPK pathways regulate expression of TE associated proteins and apoptosis in response to culture stress and may regulate expression of TE associated proteins by affecting SNAI1 and SNAI2 expression or localization during blastocyst formation. I have shown that p38 MAPK regulates Aqp3 and Aqp9 expression in response to hyperosmotic stress in the blastocyst. I have also demonstrated that p38 MAPK is required for blastocyst expansion and hatching and regulates tight junction permeability and TJP1 localization during blastocyst formation. The p38 MAPK pathway also affects Aqp3 mRNA expression and protein detection. The p38 MAPK does not regulate apoptosis, however, the JNK/SAPK pathway does. I have demonstrated that two transcription factors, Snai1 and Snai2, which are downstream targets of the p38 MAPK pathway, are present throughout preimplantation development. In other cell types, SNAI1 and SNAI2 regulate many genes involved in blastocyst formation. I have shown that in the preimplantation embryo, SNAI1 and SNAI2 have a unique asymmetric distribution pattern from the 2-cell to 8-cell stage, and are then segregated to the TE of the blastocyst. These results suggest that SNAI1 and SNAI2 may be involved in TE differentiation or regulation. Taken together, this data reveal the contributions of p38 MAPK to the regulation of preimplantation development

p38 MAPK regulates cavitation and tight junction function in the mouse blastocyst.

UNLABELLED: Blastocyst formation is essential for implantation and maintenance of pregnancy and is dependent on the expression and coordinated function of a series of proteins involved in establishing and maintaining the trans-trophectoderm ion gradient that enables blastocyst expansion. These consist of Na/K-ATPase, adherens junctions, tight junctions (TJ) and aquaporins (AQP). While their role in supporting blastocyst formation is established, the intracellular signaling pathways that coordinate their function is unclear. The p38 MAPK pathway plays a role in regulating these proteins in other cell types and is required for embryo development at the 8-16 cell stage, but its role has not been investigated in the blastocyst. HYPOTHESIS: p38 MAPK regulates blastocyst formation by regulating blastocyst formation gene expression and function. METHODS: Embryos were cultured from the early blastocyst stage for 12 h or 24 h in the presence of a potent and specific p38 MAPK inhibitor, SB 220025. Blastocyst expansion, hatching, gene family expression and localization, TJ function and apoptosis levels were analyzed. RESULTS: Inhibition of the p38 MAPK pathway reduced blastocyst expansion and hatching, increased tight junction permeability, affected TJP1 localization, reduced Aqp3 expression, and induced a significant increase in apoptosis. CONCLUSION: The p38 MAPK pathway coordinates the overall events that regulate blastocyst formation

Genomic RNA profiling and the programme controlling preimplantation mammalian development.

Preimplantation development shifts from a maternal to embryonic programme rapidly after fertilization. Although the majority of oogenetic products are lost during the maternal to embryonic transition (MET), several do survive this interval to contribute directly to supporting preimplantation development. Embryonic genome activation (EGA) is characterized by the transient expression of several genes that are necessary for MET, and while EGA represents the first major wave of gene expression, a second mid-preimplantation wave of transcription that supports development to the blastocyst stage has been discovered. The application of genomic approaches has greatly assisted in the discovery of stage specific gene expression patterns and the challenge now is to largely define gene function and regulation during preimplantation development. The basic mechanisms controlling compaction, lineage specification and blastocyst formation are defined. The requirement for embryo culture has revealed plasticity in the developmental programme that may exceed the adaptive capacity of the embryo and has fostered important research directions aimed at alleviating culture-induced changes in embryonic programming. New levels of regulation are emerging and greater insight into the roles played by RNA-binding proteins and miRNAs is required. All of this research is relevant due to the necessity to produce healthy preimplantation embryos for embryo transfer, to ensure that assisted reproductive technologies are applied in the most efficient and safest way possible

Substance use disorders in the farming population: Scoping review

Purpose The purpose of this scoping review is to summarize the current knowledge base in order to make recommendations for prevention and treatment of substance use disorders among the farming populations. Methods We conducted a scoping review of peer-reviewed articles published between January 1989 and September 2019. The search yielded 3,426 citations and the final review was conducted on 42 articles. The full review was conducted by 4 authors to extract information about the target population, data collection methods, and main results. Findings There were 21 articles on farmers and 21 articles on farmworkers. The majority of the articles were about alcohol. Overall, farmers had higher prevalence of risky alcohol consumption patterns than nonfarmers. The prevalence of risky alcohol consumption was also high among farmworkers compared to the general population. Risk factors for risky alcohol consumption included male gender, lower socioeconomic status, and psychological problems (eg, depression). Recommendations for prevention and intervention of alcohol disorders included policy development and implementation to curb alcohol access by taxation, screening of alcohol-related problems, and alternative means of recreation instead of alcohol consumption. Conclusions This review confirmed that alcohol-related problems are prevalent among farmers and farmworkers. More population-based research is called for to understand the additional risk factors of alcohol disorders and the prevalence of other substance-related disorders. Also, interventions should be tailored to the unique culture of farmers and farmworkers

Mitogen-activated protein kinase (MAPK) pathways mediate embryonic responses to culture medium osmolarity by regulating Aquaporin 3 and 9 expression and localization, as well as embryonic apoptosis.

BACKGROUND: In order to advance the development of culture conditions and increase the potential for supporting normal preimplantation embryo development in vitro, it is critical to define the mechanisms that early embryos utilize to survive in culture. We investigated the mechanisms that embryos employ in response to culture medium osmolarity. We hypothesized that mitogen-activated protein kinase (MAPK) pathways mediate responses to hyperosmotic stress by regulating Aquaporin (AQP) 3 and 9 expression as well as embryonic apoptosis. METHODS: Real-time reverse transcription and polymerase chain reaction and whole-mount immunofluorescence were used to determine the relative mRNA levels and protein localization patterns of AQP 3 and 9 after hyperosmotic medium treatment. RESULTS: At 6 and 24 h, a significant increase in Aqp 3 and 9 mRNA was observed in the sucrose hyperosmotic treatment compared with standard medium and glycerol controls. Blockade of MAPK14/11 negated the increase in Aqp 3 and 9 mRNA levels, whereas culture in a MAPK8 blocker did not. Hyperosmotic sucrose treatment significantly increased embryonic apoptosis which was negated in the presence of MAPK8 blocker, but not MAPK14/11 blocker. CONCLUSIONS: MAPK14/11 activation is a component of the rapid adaptive stress response mechanism that includes the effects of AQP mRNA expression and protein localization, whereas the MAPK8 pathway is a regulator of apoptosis

Microarray analysis of Foxa2 mutant mouse embryos reveals novel gene expression and inductive roles for the gastrula organizer and its derivatives

<p>Abstract</p> <p>Background</p> <p>The Spemann/Mangold organizer is a transient tissue critical for patterning the gastrula stage vertebrate embryo and formation of the three germ layers. Despite its important role during development, there are still relatively few genes with specific expression in the organizer and its derivatives. Foxa2 is a forkhead transcription factor that is absolutely required for formation of the mammalian equivalent of the organizer, the node, the axial mesoderm and the definitive endoderm (DE). However, the targets of Foxa2 during embryogenesis, and the molecular impact of organizer loss on the gastrula embryo, have not been well defined.</p> <p>Results</p> <p>To identify genes specific to the Spemann/Mangold organizer, we performed a microarray-based screen that compared wild-type and <it>Foxa2 </it>mutant embryos at late gastrulation stage (E7.5). We could detect genes that were consistently down-regulated in replicate pools of mutant embryos versus wild-type, and these included a number of known node and DE markers. We selected 314 genes without previously published data at E7.5 and screened for expression by whole mount <it>in situ </it>hybridization. We identified 10 novel expression patterns in the node and 5 in the definitive endoderm. We also found significant reduction of markers expressed in secondary tissues that require interaction with the organizer and its derivatives, such as cardiac mesoderm, vasculature, primitive streak, and anterior neuroectoderm.</p> <p>Conclusion</p> <p>The genes identified in this screen represent novel Spemann/Mangold organizer genes as well as potential Foxa2 targets. Further investigation will be needed to define these genes as novel developmental regulatory factors involved in organizer formation and function. We have placed these genes in a Foxa2-dependent genetic regulatory network and we hypothesize how Foxa2 may regulate a molecular program of Spemann/Mangold organizer development. We have also shown how early loss of the organizer and its inductive properties in an otherwise normal embryo, impacts on the molecular profile of surrounding tissues.</p

Nitrogen-induced terrestrial eutrophication: cascading effects and impacts on ecosystem services

Human activity has significantly increased the deposition of nitrogen (N) on terrestrial ecosystems over pre-industrial levels leading to a multitude of effects including losses of biodiversity, changes in ecosystem functioning, and impacts on human well-being. It is challenging to explicitly link the level of deposition on an ecosystem to the cascade of ecological effects triggered and ecosystem services affected, because of the multitude of possible pathways in the N cascade. To address this challenge, we report on the activities of an expert workshop to synthesize information on N-induced terrestrial eutrophication from the published literature and to link critical load exceedances with human beneficiaries by using the STressor–Ecological Production function–final ecosystem Services Framework and the Final Ecosystem Goods and Services Classification System (FEGS-CS). We found 21 N critical loads were triggered by N deposition (ranging from 2 to 39 kg N·ha−1·yr−1), which cascaded to distinct beneficiary types through 582 individual pathways in the five ecoregions examined (Eastern Temperate Forests, Marine West Coast Forests, Northwestern Forested Mountains, North American Deserts, Mediterranean California). These exceedances ultimately affected 66 FEGS across a range of final ecosystem service categories (21 categories, e.g., changes in timber production, fire regimes, and native plant and animal communities) and 198 regional human beneficiaries of different types. Several different biological indicators were triggered in different ecosystems, including grasses and/or forbs (33% of all pathways), mycorrhizal communities (22%), tree species (21%), and lichen biodiversity (11%). Ecoregions with higher deposition rates for longer periods tended to have more numerous and varied ecological impacts (e.g., Eastern Temperate Forests, eight biological indicators) as opposed to other ecoregions (e.g., North American Deserts and Marine West Coast Forests each with one biological indicator). Nonetheless, although ecoregions differed by ecological effects from terrestrial eutrophication, the number of FEGS and beneficiaries impacted was similar across ecoregions. We found that terrestrial eutrophication affected all ecosystems examined, demonstrating the widespread nature of terrestrial eutrophication nationally. These results highlight which people and ecosystems are most affected according to present knowledge, and identify key uncertainties and knowledge gaps to be filled by future research

Evidence-Based Professional Development of Science Teachers in Two Countries

The focus of this collaborative research project of King?s College London, and the Weizmann Institute, Israel. project is on investigating the ways in which teachers can demonstrate accomplished teaching in a specific domain of science and on the teacher learning that is generated through continuing professional development programs (CPD) that lead towards such practice. The interest lies in what processes and inputs are required to help secondary school science teachers develop expertise in a specific aspect of science teaching. `It focuses on the design of the CPD programmes and examines the importance of an evidence-based approach through portfolioconstruction in which professional dialogue pathes the way for teacher learning. The set of papers highlight the need to set professional challenge while tailoring CPD to teachers? needs to create the environment in which teachers can advance and transform their practice. The cross-culture perspective added to the richness of the development and enabled the researchers to examine which aspects were fundamental to the design by considering similarities and differences between the domains

Improving response rates using a monetary incentive for patient completion of questionnaires: an observational study

Background: Poor response rates to postal questionnaires can introduce bias and reduce the statistical power of a study. To improve response rates in our trial in primary care we tested the effect of introducing an unconditional direct payment of 5 pound for the completion of postal questionnaires. Methods: We recruited patients in general practice with knee problems from sites across the United Kingdom. An evidence-based strategy was used to follow-up patients at twelve months with postal questionnaires. This included an unconditional direct payment of 5 pound to patients for the completion and return of questionnaires. The first 105 patients did not receive the 5 pound incentive, but the subsequent 442 patients did. We used logistic regression to analyse the effect of introducing a monetary incentive to increase the response to postal questionnaires. Results: The response rate following reminders for the historical controls was 78.1% ( 82 of 105) compared with 88.0% ( 389 of 442) for those patients who received the 5 pound payment (diff = 9.9%, 95% CI 2.3% to 19.1%). Direct payments significantly increased the odds of response ( adjusted odds ratio = 2.2, 95% CI 1.2 to 4.0, P = 0.009) with only 12 of 442 patients declining the payment. The incentive did not save costs to the trial - the extra cost per additional respondent was almost 50 pound. Conclusion: The direct payment of 5 pound significantly increased the completion of postal questionnaires at negligible increase in cost for an adequately powered study