Multidimensional Fluorescence Imaging of Embryonic and Postnatal Mammary Gland Development

Multidimensional fluorescence imaging represents a powerful approach for studying the dynamic cellular processes underpinning the development, function, and maintenance of the mammary gland. Here, we describe key multidimensional imaging strategies that enable visualization of mammary branching morphogenesis and epithelial cell fate dynamics during postnatal and embryonic mammary gland development. These include 4-dimensional intravital microscopy and ex vivo imaging of embryonic mammary cultures, in addition to methods that facilitate 3-dimensional imaging of the ductal epithelium at single-cell resolution within its native stroma. Collectively, these approaches provide a window into mammary developmental dynamics, and the perturbations underlying tissue dysfunction and disease

Profile of a Welsh county coalfield - The Denbighshire Coalfield, 1850-1914

During the nineteenth century the British coal industry fuelled industrial growth to such an extent that Great Britain was acknowledged as the most powerful industrial country in the world. Although the coal industry was dominated by the larger regional coalfields, e.g. south Wales, the smaller coalfields also made an important, albeit largely local, contribution. This contribution has, however, often been ignored most histories either concentrate on the larger coalfields or, if examining small coalfields, they have centred on a particular event or town rather than on examining the contribution of each coalfield as a whole. This thesis will partly redress this imbalance by undertaking a 'case study' of a small, county coalfield, Denbighshire. For official purposes, Denbighshire was never considered a coalfield in its own right, it was merely recognised as part of the north Wales 'coalfield'. It is, however, argued in this thesis that geological factors and its significance within the north Wales coalfield, mean that Denbighshire warrants consideration as a small coalfield in its own right. This thesis attempts to develop, for the first time, a definitive history of the coal industry in Denbighshire, 1850--1914, through the use of an archival approach. Source material, including company records, newspapers, personal letters and official statistics, was examined. The thesis considers not only the performance of the coalfield in terms of productivity and profitability but also the various stakeholders in the coalfield, i.e. those people who, either directly or indirectly, influenced, or were influenced by, the development of the Denbighshire coal industry. Apart from establishing that Denbighshire should be treated as a small coalfield in its own right, it is concluded that the performance of Denbighshire was comparable to that of other 'small' coalfields and that, although affected by similar influences to other coalfields, the extent of their impact could be different.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Profile of a Welsh county coalfield - The Denbighshire Coalfield, 1850-1914

During the nineteenth century the British coal industry fuelled industrial growth to such an extent that Great Britain was acknowledged as the most powerful industrial country in the world. Although the coal industry was dominated by the larger regional coalfields, e.g. south Wales, the smaller coalfields also made an important, albeit largely local, contribution. This contribution has, however, often been ignored most histories either concentrate on the larger coalfields or, if examining small coalfields, they have centred on a particular event or town rather than on examining the contribution of each coalfield as a whole. This thesis will partly redress this imbalance by undertaking a 'case study' of a small, county coalfield, Denbighshire. For official purposes, Denbighshire was never considered a coalfield in its own right, it was merely recognised as part of the north Wales 'coalfield'. It is, however, argued in this thesis that geological factors and its significance within the north Wales coalfield, mean that Denbighshire warrants consideration as a small coalfield in its own right. This thesis attempts to develop, for the first time, a definitive history of the coal industry in Denbighshire, 1850--1914, through the use of an archival approach. Source material, including company records, newspapers, personal letters and official statistics, was examined. The thesis considers not only the performance of the coalfield in terms of productivity and profitability but also the various stakeholders in the coalfield, i.e. those people who, either directly or indirectly, influenced, or were influenced by, the development of the Denbighshire coal industry. Apart from establishing that Denbighshire should be treated as a small coalfield in its own right, it is concluded that the performance of Denbighshire was comparable to that of other 'small' coalfields and that, although affected by similar influences to other coalfields, the extent of their impact could be different

High-throughput screening for novel regulators of Beta-catenin in Wnt signalling

Beta-catenin is a crucial component of the Wnt signalling pathway, which is imperative in many developmental processes and aberrantly regulated in several different cancers. The standard model of Wnt/Beta-catenin signalling states that, upon stimulation by Wnt ligand, Beta-catenin accumulates and subsequently translocates to the nucleus to activate TCF-dependent transcription of a variety of target genes, including oncogenes. However, the mechanisms regulating the nuclear localisation of Beta-catenin and its correlation with TCF-dependent transcription are poorly understood. In order to identify novel regulators of Beta-catenin levels and localisation in Wnt signalling imaging-based high-throughput knockout screens were developed in a Wnt inducible cell line, in addition to a cancer cell line in the presence of normal and downregulated APC. Results from the screens show that, in addition to known Wnt signalling components, genes not previously ascribed to the pathway appeared to modulate Beta-catenin. The study has provided sources of possible mechanistic insights into a number of areas of biology that may be involved in β-catenin regulation. Furthermore, it reveals an unprecedented degree of cross talk between Wnt and many other major signalling pathways. Moreover, the data indicated a degree of cell-type specificity in the regulators identified and, significantly, a lack of correlation between β-catenin levels and transcriptional activity

The immune environment of the mammary gland fluctuates during post-lactational regression and correlates with tumour growth rate

Post-lactational mammary gland regression encompasses extensive programmed cell death and removal of milk-producing epithelial cells, breakdown of extracellular matrix components and redifferentiation of stromal adipocytes. This highly regulated involution process is associated with a transient increased risk of breast cancer in women. Using a syngeneic tumour model, we show that tumour growth is significantly altered depending on the stage of involution at which tumour cells are implanted. Tumour cells injected at day 3 involution grew faster than those in nulliparous mice, whereas tumours initiated at day 6 involution grew significantly slower. These differences in tumour progression correlate with distinct changes in innate immune cells, in particular among F4/80-expressing macrophages and among TCRδ(+) unconventional T cells. Breast cancer post-pregnancy risk is exacerbated in older first-time mothers and, in our model, initial tumour growth is moderately faster in aged mice compared with young mice. Our results have implications for breast cancer risk and the use of anti-inflammatory therapeutics for postpartum breast cancers

In vivo imaging of mammary epithelial cell dynamics in response to lineage-biased Wnt/β-catenin activation

International audienceHighlights d Lineage-biased b-catenin activation in mammary cells leads to hyperplastic lesions d Intravital imaging reveals mammary cell dynamics induced by b-catenin activation d Constitutive Wnt signaling induces squamous transdifferentiation of mammary cell