In vivo analysis reveals a critical role for neuropilin-1 in cranial neural crest cell migration in chick

AbstractThe neural crest provides an excellent model system to study invasive cell migration, however it is still unclear how molecular mechanisms direct cells to precise targets in a programmed manner. We investigate the role of a potential guidance factor, neuropilin-1, and use functional knockdown assays, tissue transplantation and in vivo confocal time-lapse imaging to analyze changes in chick cranial neural crest cell migratory patterns. When neuropilin-1 function is knocked down in ovo, neural crest cells fail to fully invade the branchial arches, especially the 2nd branchial arch. Time-lapse imaging shows that neuropilin-1 siRNA transfected neural crest cells stop and collapse filopodia at the 2nd branchial arch entrances, but do not die. This phenotype is cell autonomous. To test the influence of population pressure and local environmental cues in driving neural crest cells to the branchial arches, we isochronically transplanted small subpopulations of DiI-labeled neural crest cells into host embryos ablated of neighboring, premigratory neural crest cells. Time-lapse confocal analysis reveals that the transplanted cells migrate in narrow, directed streams. Interestingly, with the reduction of neuropilin-1 function, neural crest cells still form segmental migratory streams, suggesting that initial neural crest cell migration and invasion of the branchial arches are separable processes

2nd International Consensus Report on Gaps & Opportunities for the Clinical Translation of Precision Diabetes Medicine

Precision medicine is part of the logical evolution of contemporary evidence-based medicine that seeks to reduce errors and optimize outcomes when making medical decisions and health recommendations. Diabetes affects hundreds of millions worldwide, many of whom will develop life-threatening complications and die prematurely. Precision medicine can potentially address this enormous problem by accounting for the heterogeneous etiology, clinical presentation, and pathogenesis of common forms of diabetes and risk of complications. This 2nd International Consensus Report on Precision Diabetes Medicine summarize the findings from a systematic evidence review across the key pillars of precision medicine (prevention, diagnosis, treatment, prognosis) in four recognized forms of diabetes (monogenic, gestational, type 1, type 2). These reviews address key questions about translation of precision medicine research into practice. Although not complete, owing to the vast literature on this topic, they revealed opportunities for the immediate or near-term clinical implementation of precision diabetes medicine; further, we expose important gaps in knowledge, focusing on the need to obtain new clinically relevant evidence. Gaps include the need for common standards for clinical readiness, including consideration of cost-effectiveness, health equity, predictive accuracy, liability, and accessibility. Key milestones are outlined for the broad clinical implementation of precision diabetes medicine

Multispectral fingerprinting for improved in vivo cell dynamics analysis

Background: Tracing cell dynamics in the embryo becomes tremendously difficult when cell trajectories cross in space and time and tissue density obscure individual cell borders. Here, we used the chick neural crest (NC) as a model to test multicolor cell labeling and multispectral confocal imaging strategies to overcome these roadblocks. Results: We found that multicolor nuclear cell labeling and multispectral imaging led to improved resolution of in vivo NC cell identification by providing a unique spectral identity for each cell. NC cell spectral identity allowed for more accurate cell tracking and was consistent during short term time-lapse imaging sessions. Computer model simulations predicted significantly better object counting for increasing cell densities in 3-color compared to 1-color nuclear cell labeling. To better resolve cell contacts, we show that a combination of 2-color membrane and 1-color nuclear cell labeling dramatically improved the semi-automated analysis of NC cell interactions, yet preserved the ability to track cell movements. We also found channel versus lambda scanning of multicolor labeled embryos significantly reduced the time and effort of image acquisition and analysis of large 3D volume data sets. Conclusions: Our results reveal that multicolor cell labeling and multispectral imaging provide a cellular fingerprint that may uniquely determine a cell's position within the embryo. Together, these methods offer a spectral toolbox to resolve in vivo cell dynamics in unprecedented detail

Targeting metabolic health promotion to optimise maternal and offspring health

There is an increase in maternal metabolic burden due to the rise in pregnancies complicated by obesity, gestational diabetes, type 2 diabetes and polycystic ovary syndrome. Metabolic dysfunction during pregnancy is associated with increased risks of long-term morbidity and mortality for women and their offspring. Lifestyle interventions in pregnancy in women at risk of metabolic dysfunction have demonstrated short-term improvements such as reduced gestational weight gain and lowered risk of gestational diabetes. It is not known whether these interventions lead to sustained improvements in the metabolic health of the mother and baby. Pharmacological interventions have also shown benefits for the mother and baby in pregnancy, including improvements in glycaemic control, reduction in gestational weight gain and reduction in large for gestational age infants; however, there remains uncertainty over long-term outcomes for mother and child. Existing studies on interventions targeting metabolic health are limited to selected populations in the preconception and postpartum periods and lack follow-up beyond delivery of the intervention. The COVID-19 pandemic has refocused our attention on the effects of maternal metabolic ill-health that play a role in contributing to premature morbidity and mortality. There is an urgent need for strategies to accurately identify the growing number of women and offspring at risk of long-term adverse metabolic health. Strategies which focus on early identification and risk stratification using individualised risk scores in the pre and inter-conception periods must take priority if we are to target and improve the metabolic health of women and their offspring who are at highest risk

Curriculum development for social work student placements in Primary Health care

This paper reports on the curriculum development for social work student placements in primary health care. Social work in General Practice [GP] is an emerging area for social work practice, able to fill a gap in primary health. The inclusion of social work in GP practices can be complex. Social work placements offer an opportunity for students to become familiar with this practice setting and undertake social work relevant learning; however, they need to be well prepared for such placements and able to articulate and use social work knowledge and processes. They offer an opportunity for GPs to understand what social workers can do and offer to the GP community. We have used available research, support of an active reference group and two surveys to develop a curriculum for social work students in GP practices. We provide an overview of the literature and the methods of developing the curriculum. We describe how feedback and curriculum design principles were used. Core aspects of the curriculum and accompanying resources are outlined. The discussion highlights that the curriculum was a valuable tool in not only inducting students into a GP placement setting but as a meaningful reference guide throughout the entirety of placement

Dynamic fibronectin assembly and remodeling by leader neural crest cells prevents jamming in collective cell migration

Collective cell migration plays an essential role in vertebrate development, yet the extent to which dynamically changing microenvironments influence this phenomenon remains unclear. Observations of the distribution of the extracellular matrix (ECM) component fibronectin during the migration of loosely connected neural crest cells (NCCs) lead us to hypothesize that NCC remodeling of an initially punctate ECM creates a scaffold for trailing cells, enabling them to form robust and coherent stream patterns. We evaluate this idea in a theoretical setting by developing an agent-based model that incorporates reciprocal interactions between NCCs and their ECM. ECM remodeling, haptotaxis, contact guidance, and cell-cell repulsion are sufficient for cells to establish streams in silico, however additional mechanisms, such as chemotaxis, are required to consistently guide cells along the correct target corridor. Further investigations of the model imply that contact guidance and differential cell-cell repulsion between leader and follower cells are key contributors to robust collective cell migration by preventing stream breakage. Global sensitivity analysis and simulated underexpression/overexpression experiments suggest that long-distance migration without jamming is most likely to occur when leading cells specialize in creating ECM fibers, and trailing cells specialize in responding to environmental cues by upregulating mechanisms such as contact guidance.Comment: 46 pages, 7 figures (of which 2 are supplementary

Evidence for dynamic rearrangements but lack of fate or position restrictions in premigratory avian trunk neural crest

Neural crest (NC) cells emerge from the dorsal trunk neural tube (NT) and migrate ventrally to colonize neuronal derivatives, as well as dorsolaterally to form melanocytes. Here, we test whether different dorsoventral levels in the NT have similar or differential ability to contribute to NC cells and their derivatives. To this end, we precisely labeled NT precursors at specific dorsoventral levels of the chick NT using fluorescent dyes and a photoconvertible fluorescent protein. NT and NC cell dynamics were then examined in vivo and in slice culture using two-photon and confocal time-lapse imaging. The results show that NC precursors undergo dynamic rearrangements within the neuroepithelium, yielding an overall ventral to dorsal movement toward the midline of the NT, where they exit in a stochastic manner to populate multiple derivatives. No differences were noted in the ability of precursors from different dorsoventral levels of the NT to contribute to NC derivatives, with the exception of sympathetic ganglia, which appeared to be ‘filled’ by the first population to emigrate. Rather than restricted developmental potential, however, this is probably due to a matter of timing