Liver organoids: from basic research to therapeutic applications.

Organoid cultures have emerged as an alternative in vitro system to recapitulate tissues in a dish. While mouse models and cell lines have furthered our understanding of liver biology and associated diseases, they suffer in replicating key aspects of human liver tissue, in particular its complex architecture and metabolic functions. Liver organoids have now been established for multiple species from induced pluripotent stem cells, embryonic stem cells, hepatoblasts and adult tissue-derived cells. These represent a promising addition to our toolbox to gain a deeper understanding of this complex organ. In this perspective we will review the advances in the liver organoid field, its limitations and potential for biomedical applications.Acknowledgements M.H. is a Wellcome Trust Sir Henry Dale Fellow and is jointly funded by the Wellcome Trust and the Royal Society (104151/Z/14/Z). This work was partially funded by a H2020 LSMF4LIFE awarded to M.H. PI is funded by the NC3Rs (NC/R001162/1). The authors acknowledge core funding to the Gurdon Institute from the Wellcome Trust (092096) and CRUK (C6946/A14492)

Staff experiences of a reablement approach to care for older people in a regional Australian community : a qualitative study

Reablement is described as a person-centred, goal-directed intervention with a view to regain, maintain or improve the independence of older clients. Although evidence to support the use of reablement as a multidisciplinary, home-based intervention for community-dwelling older adults is increasing, there is limited knowledge about what it means for care staff who provide client-based services. This study, which was nested in a larger program evaluation, used a descriptive qualitative approach to explore direct care staff and care coordinator experiences of translating a reablement training program into practice for older people in a regional Australian community. Two months after the training program four focus groups were conducted with 13 care coordinators to assimilate staff experiences with development of care plans, systems, processes and practices of reablement. In addition, four direct care staff took part in individual interviews, which centred on eliciting their experience using the reablement approach with clients. Results from the care coordinator focus groups and the direct care staff interviews highlight the importance of reablement staff training and the involvement of staff in the development and delivery of a reablement approach to client-centred care. A number of organisational and client-centred challenges such as communication, functional partnerships, staff education and resourcing are also uncovered in this research into the development of a reablement-focused care service in a regional setting. Overall there is support for the dominating discourse around healthy ageing and the policy approach of ageing in place to support wellness

Lgr5+ stem and progenitor cells reside at the apex of a heterogeneous embryonic hepatoblast pool.

During mouse embryogenesis, progenitors within the liver known as hepatoblasts give rise to adult hepatocytes and cholangiocytes. Hepatoblasts, which are specified at E8.5-E9.0, have been regarded as a homogeneous progenitor population that initiate differentiation from E13.5. Recently, scRNA-seq analysis has identified sub-populations of transcriptionally distinct hepatoblasts at E11.5. Here, we show that hepatoblasts are not only transcriptionally but also functionally heterogeneous, and that a subpopulation of E9.5-E10.0 hepatoblasts exhibit a previously unidentified early commitment to cholangiocyte fate. Importantly, we also identify a subpopulation constituting 2% of E9.5-E10.0 hepatoblasts that express the adult stem cell marker Lgr5, and generate both hepatocyte and cholangiocyte progeny that persist for the lifespan of the mouse. Combining lineage tracing and scRNA-seq, we show that Lgr5 marks E9.5-E10.0 bipotent liver progenitors residing at the apex of a hepatoblast hierarchy. Furthermore, isolated Lgr5+ hepatoblasts can be clonally expanded in vitro into embryonic liver organoids, which can commit to either hepatocyte or cholangiocyte fates. Our study demonstrates functional heterogeneity within E9.5 hepatoblasts and identifies Lgr5 as a marker for a subpopulation of bipotent liver progenitors.M.H. is a Wellcome Trust Sir Henry Dale Fellow and is jointly funded by the Wellcome Trust and the Royal Society (104151/Z/14/Z); M.H. and N.P. are funded by a Horizon 2020 grant (LSFM4LIFE). C.H. was funded by a Cambridge Stem Cell Institute Seed funding for interdisciplinary research awarded to M.H. and B.D.S., B.D.S acknowledges funding from the Royal Society E.P. Abraham Research Professorship (RP\R1\180165) and Wellcome Trust (098357/Z/12/Z). W.L. and B.G. were supported by programmatic funding from the Wellcome Trust, CRUK and Bloodwise, core infrastructure support from the Wellcome and MRC to the Wellcome & MRC Cambridge Stem Cell Institute, and an MRC Clinical Research Infrastructure grant supporting single cell molecular analysis. S.R. was funded on a Herchel-Smith Fellowship. The authors acknowledge core funding to the Gurdon Institute from the Wellcome Trust (092096) and CRUK (C6946/A14492)

SMN Protein Can Be Reliably Measured in Whole Blood with an Electrochemiluminescence (ECL) Immunoassay: Implications for Clinical Trials

Spinal muscular atrophy (SMA) is caused by defects in the survival motor neuron 1 (SMN1) gene that encodes survival motor neuron (SMN) protein. The majority of therapeutic approaches currently in clinical development for SMA aim to increase SMN protein expression and there is a need for sensitive methods able to quantify increases in SMN protein levels in accessible tissues. We have developed a sensitive electrochemiluminescence (ECL)-based immunoassay for measuring SMN protein in whole blood with a minimum volume requirement of 5μL. The SMN-ECL immunoassay enables accurate measurement of SMN in whole blood and other tissues. Using the assay, we measured SMN protein in whole blood from SMA patients and healthy controls and found that SMN protein levels were associated with SMN2 copy number and were greater in SMA patients with 4 copies, relative to those with 2 and 3 copies. SMN protein levels did not vary significantly in healthy individuals over a four-week period and were not affected by circadian rhythms. Almost half of the SMN protein was found in platelets. We show that SMN protein levels in C/C-allele mice, which model a mild form of SMA, were high in neonatal stage, decreased in the first few weeks after birth, and then remained stable throughout the adult stage. Importantly, SMN protein levels in the CNS correlated with SMN levels measured in whole blood of the C/C-allele mice. These findings have implications for the measurement of SMN protein induction in whole blood in response to SMN-upregulating therapy

RNF43/ZNRF3 loss predisposes to hepatocellular-carcinoma by impairing liver regeneration and altering the liver lipid metabolic ground-state.

RNF43/ZNRF3 negatively regulate WNT signalling. Both genes are mutated in several types of cancers, however, their contribution to liver disease is unknown. Here we describe that hepatocyte-specific loss of Rnf43/Znrf3 results in steatohepatitis and in increase in unsaturated lipids, in the absence of dietary fat supplementation. Upon injury, Rnf43/Znrf3 deletion results in defective hepatocyte regeneration and liver cancer, caused by an imbalance between differentiation/proliferation. Using hepatocyte-, hepatoblast- and ductal cell-derived organoids we demonstrate that the differentiation defects and lipid alterations are, in part, cell-autonomous. Interestingly, ZNRF3 mutant liver cancer patients present poorer prognosis, altered hepatic lipid metabolism and steatohepatitis/NASH signatures. Our results imply that RNF43/ZNRF3 predispose to liver cancer by controlling the proliferative/differentiation and lipid metabolic state of hepatocytes. Both mechanisms combined facilitate the progression towards malignancy. Our findings might aid on the management of those RNF43/ZNRF3 mutated individuals at risk of developing fatty liver and/or liver cancer

Noninvasive Vascular Images for Face Transplant Surgical Planning

Objective: Face transplantation replaces substantial defects with anatomically identical donor tissues; preoperative vascular assessment relies on noninvasive imaging to separate and characterize the external carotid vessels and branches. The objective is to describe and illustrate vascular considerations for face transplantation candidates. Methods: Novel noninvasive imaging using computed tomography and magnetic resonance imaging over 3 spatial dimensions plus time was developed and tested in 4 face transplant candidates. Precontrast images assessed bones and underlying metal. Contrast media was used to delineate and separate arteries from veins. For computed tomography, acquisition over multiple time points enabled the computation of tissue perfusion metrics. Time-resolved magnetic resonance angiography was performed to separate arterial and venous phases. Results: The range of circulation times for the external carotid system was 6 to 14 seconds from arterial blush to loss of venous enhancement. Precontrast imaging provided a roadmap of bones and metal. Among the 4 patients, 3 had surgical clips, metal implants, or both within 1 cm of major vessels considered for surgery. Contrast-enhanced wide area detector computed tomographic data acquired in the axial mode separated these structures and provided arterial and venous images for planning the surgical anastomoses. Magnetic resonance imaging was able to distinguish between the large vessels from the external carotid systems. Conclusions: Vascular imaging maps are challenging in face transplantation because of the rapid circulation times and artifact from the initial injury, prior reconstructive attempts, or both. Nevertheless, face transplant candidates require high spatial and temporal resolution vascular imaging to determine those vessels appropriate for surgical anastomoses

El Estado colombiano ante el emprendimiento en clave de género

La formulación de políticas públicas diferenciadas tiene como base no sólo las demandas internacionales a las que se ha acogido el Estado colombiano, sino también las realidades del territorio como lo es el porcentaje de crecimiento del grupo de mujeres: De acuerdo con las proyecciones de crecimiento poblacional (DANE, 2005), para 2011, las mujeres representarían el 50,6% de la población total colombiana, equivalente a 23.313.302 millones de mujeres, frente a 22.731.299 millones de hombres que representarían el 49,4%. Con una mayor concentración en las zonas urbanas, con el 75,6%. Con base en las anteriores consideraciones, es fundamental traer a colación a la población femenina que abarca más del 50% de la población colombiana. Por lo tanto, es pertinente el presente trabajo de grado al tener como principal énfasis las políticas públicas del Estado colombiano para las mujeres enfocadas en el área del emprendimiento, ya que su potencialización llevaría al Estado a contar con una herramienta para la erradicación de la pobreza y lograr un país más equitativo no solo desde la formulación de políticas sino en su implementación. Se hace necesario, en un primer momento, identificar los principales debates teóricos sobre la relación de las mujeres y su participación política en cuanto al emprendimiento y a la construcción social de país. En contraposición a los enfoques institucionales que han posicionado a la mujer desde un paradigma asistencialista, seguido por uno de riesgo, vulnerabilidad y violencia, para, finalmente, llegar a un enfoque de desarrollo integral. El análisis se presenta en el primer capítulo. En un segundo momento, es decir el capítulo dos, se presentará el componente teórico del desarrollo del emprendimiento en Colombia. Posteriormente, en el tercer capítulo, se analizarán las entrevistas realizadas a mujeres emprendedoras de los diferentes niveles sociales y a hombres, empleados y funcionarios tanto del sector público como privado. El análisis da cuenta de la influencia de las políticas públicas de emprendimiento, al tener como punto de referencia las relaciones instituciones estatales como mujer emprendedora y sus relaciones dentro de organizaciones y cómo esto repercute en su participación política y en la construcción del desarrollo social en Colombia. Se identificarán, igualmente, las causas y variables que impiden llevar a la realidad las políticas públicas de emprendimiento en clave de género y así medir o cualificar la manera en que el Estado colombiano aporta al desarrollo de los emprendimientos de las mujeres en el periodo 2000 – 2018.The formulation of differentiated public policies is based not only on the international demands to which the Colombian State has accepted, but also on the realities of the territory, as is the percentage of growth of the group of women: According to the projections of population growth (DANE, 2005), for 2011, women would represent 50.6% of the total Colombian population, equivalent to 23,313,302 million women, compared to 22,731,299 million men who would represent 49.4%. With a greater concentration in urban areas, with 75.6%. Based on the above considerations, it is essential to bring up the female population that covers more than 50% of the Colombian population. Therefore, the present degree work is relevant, having as main emphasis the public policies of the Colombian State for women focused in the area of entrepreneurship, because that potentialization would lead the State to have a tool for the eradication of poverty and achieve a more equitable country not only from the formulation of policies, but also in its implementation. It is necessary, at first, to identify the main theoretical debates on the relationship of women and their political participation in terms of entrepreneurship and the social construction of the country. In contrast to the institutional approaches that have positioned women from a welfare paradigm, followed by one of risk, vulnerability and violence, to finally reach an integral development approach. The analysis is presented in the first chapter. In a second moment, that is to say chapter two, the theoretical component of the development of entrepreneurship in Colombia will be presented. Subsequently, in the third chapter, the interviews conducted with women entrepreneurs from different social levels and men, employees and officials from both the public and private sectors will be analyzed. The analysis explains of the influence of public policies on entrepreneurship, having as a point of reference the relations between state institutions as an entrepreneur and their relationships within organizations and how this affects their political participation and the construction of social development in Colombia. It will also identify the causes and variables that prevent the realization of public policies of entrepreneurship in terms of gender and thus measure or qualify the way in which the Colombian State contributes to the development of women's enterprises in the period 2000 - 2018Magíster en Estudios PolíticosMaestrí

Universality of clone dynamics during tissue development.

The emergence of complex organs is driven by the coordinated proliferation, migration and differentiation of precursor cells. The fate behaviour of these cells is reflected in the time evolution their progeny, termed clones, which serve as a key experimental observable. In adult tissues, where cell dynamics is constrained by the condition of homeostasis, clonal tracing studies based on transgenic animal models have advanced our understanding of cell fate behaviour and its dysregulation in disease (1, 2). But what can be learned from clonal dynamics in development, where the spatial cohesiveness of clones is impaired by tissue deformations during tissue growth? Drawing on the results of clonal tracing studies, we show that, despite the complexity of organ development, clonal dynamics may converge to a critical state characterized by universal scaling behaviour of clone sizes. By mapping clonal dynamics onto a generalization of the classical theory of aerosols, we elucidate the origin and range of scaling behaviours and show how the identification of universal scaling dependences may allow lineage-specific information to be distilled from experiments. Our study shows the emergence of core concepts of statistical physics in an unexpected context, identifying cellular systems as a laboratory to study non-equilibrium statistical physics.Wellcome Trus

High-resolution mapping reveals topologically distinct cellular pools of phosphatidylserine

Phosphatidylserine exists lumenally in the ER, Golgi, and mitochondria but cytoplasmically in the trans-Golgi and at the plasma membrane, which suggests that functionally important flipping may occur during trafficking