HIF-1-Independent Mechanisms Regulating Metabolic Adaptation in Hypoxic Cancer Cells

In solid tumours, cancer cells exist within hypoxic microenvironments, and their metabolic adaptation to this hypoxia is driven by HIF-1 transcription factor, which is overexpressed in a broad range of human cancers. HIF inhibitors are under pre-clinical investigation and clinical trials, but there is evidence that hypoxic cancer cells can adapt metabolically to HIF-1 inhibition, which would provide a potential route for drug resistance. Here, we review accumulating evidence of such adaptions in carbohydrate and creatine metabolism and other HIF-1-independent mechanisms that might allow cancers to survive hypoxia despite anti-HIF-1 therapy. These include pathways in glucose, glutamine, and lipid metabolism; epigenetic mechanisms; post-translational protein modifications; spatial reorganization of enzymes; signalling pathways such as Myc, PI3K-Akt, 2-hyxdroxyglutarate and AMP-activated protein kinase (AMPK); and activation of the HIF-2 pathway. All of these should be investigated in future work on hypoxia bypass mechanisms in anti-HIF-1 cancer therapy. In principle, agents targeted toward HIF-1β rather than HIF-1α might be advantageous, as both HIF-1 and HIF-2 require HIF-1β for activation. However, HIF-1β is also the aryl hydrocarbon nuclear transporter (ARNT), which has functions in many tissues, so off-target effects should be expected. In general, cancer therapy by HIF inhibition will need careful attention to potential resistance mechanisms.

Investigating molecular crowding during cell division in budding yeast with FRET

Cell division, aging, and stress recovery triggers the spatial reorganization of cellular components in the cytoplasm, but also of membrane bound organelles, with molecular changes in their compositions and structures. However, it is not clear how these events are coordinated and how they integrate with regulation of molecular crowding. We use the budding yeast Saccharomyces cerevisiae as a model eukaryotic unicellular organism to study these questions using recent progress in optical fluorescence microscopy and crowding sensing probe technology. We used a F&oumlrster Resonance Energy Transfer (FRET) based sensor, illuminated by confocal microscopy for high throughput analyses and Slimfield microscopy for single-molecule resolution, to quantify molecular crowding. We determine crowding in response to growth and osmotic stress, and its dependence on mother and daughter cells during division, and find unexpectedly the presence of hot spots of crowding across the bud neck in the burgeoning daughter cell, which might be rationalized by the packing of inherited material, like the vacuole, from mother cells. We discuss recent advances in understanding the role of crowding in cellular regulation and key current challenges, and conclude by presenting our recent advances in optimizing FRET-based measurements of crowding whilst simultaneously imaging a third colour, which can be used as an organelle marker and to readout membrane morphology. Our approaches can be combined with synchronised cell populations to increase experimental throughput and correlate molecular crowding information with different stages in the cell cycle.

Clock proteins regulate spatiotemporal organization of clock genes to control circadian rhythms

Circadian clocks regulate ∼24-h oscillations in gene expression, behavior, and physiology. While the genetic and molecular mechanisms of circadian rhythms are well characterized, what remains poorly understood are the intracellular dynamics of circadian clock components and how they affect circadian rhythms. Here, we elucidate how spatiotemporal organization and dynamics of core clock proteins and genes affect circadian rhythms in Drosophila clock neurons. Using high-resolution imaging and DNA-fluorescence in situ hybridization techniques, we demonstrate that Drosophila clock proteins (PERIOD and CLOCK) are organized into a few discrete foci at the nuclear envelope during the circadian repression phase and play an important role in the subnuclear localization of core clock genes to control circadian rhythms. Specifically, we show that core clock genes, period and timeless, are positioned close to the nuclear periphery by the PERIOD protein specifically during the repression phase, suggesting that subnuclear localization of core clock genes might play a key role in their rhythmic gene expression. Finally, we show that loss of Lamin B receptor, a nuclear envelope protein, leads to disruption of PER foci and per gene peripheral localization and results in circadian rhythm defects. These results demonstrate that clock proteins play a hitherto unexpected role in the subnuclear reorganization of core clock genes to control circadian rhythms, revealing how clocks function at the subcellular level. Our results further suggest that clock protein foci might regulate dynamic clustering and spatial reorganization of clock-regulated genes over the repression phase to control circadian rhythms in behavior and physiology.

Co-development of central and peripheral neurons with trunk mesendoderm in human elongating multi-lineage organized gastruloids

Stem cell technologies including self-assembling 3D tissue models provide access to early human neurodevelopment and fundamental insights into neuropathologies. Gastruloid models have not been used to investigate co-developing central and peripheral neuronal systems with trunk mesendoderm which we achieve here in elongating multi-lineage organized (EMLO) gastruloids. We evaluate EMLOs over a forty-day period, applying immunofluorescence of multi-lineage and functional biomarkers, including day 16 single-cell RNA-Seq, and evaluation of ectodermal and non-ectodermal neural crest cells (NCCs). We identify NCCs that differentiate to form peripheral neurons integrated with an upstream spinal cord region after day 8. This follows initial EMLO polarization events that coordinate with endoderm differentiation and primitive gut tube formation during multicellular spatial reorganization. This combined human central-peripheral nervous system model of early organogenesis highlights developmental events of mesendoderm and neuromuscular trunk regions and enables systemic studies of tissue interactions and innervation of neuromuscular, enteric and cardiac relevance.

New Governance Through Digital Platforms and the Old Urban Planning Process in Italy

Current acceleration in digital innovations, unexpected challenges in our social interactions, acceleration to virtualization, limitation in our physical spaces, and unpredictable changes in our Old lifestyles - as originated from the COVID-19 global pandemic 2020 - continue to provide us with a framework, rapidly updating under our eyes, of the modifications our world is undergoing by pursuing into a New “digital age”. Or, as many scholars say nowadays, into the New Normal! These are shared and deep changes that concretely stress their effects on how ideally a city should function. Forcing us to reflect on the capability to achieve shared choices and visions for the future by taking vantage from both the New digital platforms and New suddenly opened paths. In the pages of this article authors, through different but shared viewpoints, propose an answer to the topic of "Governance 3.0", addressing the attempt of a radical change of those paradigms, now consolidated, within which the spatial dimensions, in which we live and act, are shaped. Also analyzing the relationship between Technocracy and Democracy as defined by Khanna, it is argued that it is possible to realize new forecasts and acquire a more democratic and participatory (inclusive) dimension of Governance, also thanks to new digital technologies, by exploring the general unconscious "feeling" of people, through anonymous data collection and without any direct or indirect interference with it. The analysis of the "Sentiment", already developed in other fields but easily exportable within the urban discipline, can be considered as the beginning of hybrid practices where digital and analogic find a compromise to make the "Urbs" more attractive and inclusive, while the "Civitas", connected to the Internet, can contribute to the optimization of services, of the "Polis" and a new social/spatial reorganization.

LA DINAMIZACIÓN DE CADENAS AGROINDUSTRIALES URUGUAYAS EN CONTEXTO DE EXPANSIÓN COMERCIAL GLOBAL (2001-2019)

La producción y el comercio mundial agroindustrial ha registrado un importante incremento en el presente siglo. Algunos países en América Latina, especialmente los sudamericanos se han reposicionado como importantes abastecedores de bienes agrarios. Si bien la expansión tiene múltiples causas, el acelerado crecimiento económico que ha evidenciado en los últimos veinte años la región Asia-Pacífico, motorizado principalmente por China, así como otras regiones y países emergentes, ha estado en la base de este proceso. En ese contexto, Uruguay ha sido uno de los países sudamericanos que ha mostrado un importante dinamismo. En este artículo se analiza cómo este país, históricamente agroexportador, acompañó la expansión de la producción y el comercio mundial de base agraria, desarrollando sus vínculos con el mercado externo a partir de sus principales cadenas industriales relacionadas con la producción de soja, forestación, carne, arroz y lácteos. La clave este proceso implicó, entre otras cosas, una reorganización espacial de las actividades agropecuarias, la captación de inversión extranjera directa, así como potentes transformaciones en materia de innovación tecnológica y gestión de los agronegocios.Palabras claveagroindustria; agronegocios; alimentos; cadenas productivas; comercio mundial; exportaciones; innovación; Uruguay AbstracWorld agro-industrial production and trade has registered a significant increase in this century. Some Latin American countries, especially in South America, have repositioned themselves as important suppliers of agricultural products. Although the expansion has multiple causes, the accelerated economic growth that the Asia-Pacific region has shown in the last twenty years, driven mainly by China, as well as other regions and emerging countries, has been the basis of this process. In this context, Uruguay has been one of the South American countries that has shown significant dynamism. This article analyzes how this country, historically agro-exporter, accompanied the expansion of production and world trade based on agriculture, developing its links with the external market from its main industrial chains related to the production of soy, forestry, meat, rice and dairy products. Products Products The key to this process involved, among other things, a spatial reorganization of agricultural activities, the attraction of foreign direct investment, as well as powerful transformations in terms of technological innovation and agribusiness management.Keywordsagroindustry; agribusiness; foods; productive chains; world trade; exports; innovation; Uruguay

Rural Free Delivery, 1896–1913

In the 1890s and early 1900s, the Post Office Department launched an unprecedented spatial reorganization of its postal network: Rural Free Delivery, when mail carriers started delivering mail to the doorsteps of individual homes. Chapter 7 details the rollout of Rural Free Delivery, which was put into motion through an alliance between department administrators and agrarian reformers. This initiative triggered a spatial and administrative shift in the US Post, as it altered the geography of the network while ushering in a more recognizably modern bureaucracy made up of professional civil servants. But mapping the spread of the service reveals that Rural Free Delivery did not initially extend to the rural West. There, the older agency model would continue to define mail service well into the twentieth century.

Glucose restriction drives spatial reorganization of mevalonate metabolism

Eukaryotes compartmentalize metabolic pathways into sub-cellular domains, but the role of inter-organelle contacts in organizing metabolic reactions remains poorly understood. Here, we show that in response to acute glucose restriction (AGR) yeast undergo metabolic remodeling of their mevalonate pathway that is spatially coordinated at nucleus-vacuole junctions (NVJs). The NVJ serves as a metabolic platform by selectively retaining HMG-CoA Reductases (HMGCRs), driving mevalonate pathway flux in an Upc2-dependent manner. Both spatial retention of HMGCRs and increased mevalonate pathway flux during AGR is dependent on NVJ tether Nvj1. Furthermore, we demonstrate that HMGCRs associate into high molecular weight assemblies during AGR in an Nvj1-dependent manner. Loss of Nvj1-mediated HMGCR partitioning can be bypassed by artificially multimerizing HMGCRs, indicating NVJ compartmentalization enhances mevalonate pathway flux by promoting the association of HMGCRs in high molecular weight assemblies. Loss of HMGCR compartmentalization perturbs yeast growth following glucose starvation, indicating it promotes adaptive metabolic remodeling. Collectively we propose a non-canonical mechanism regulating mevalonate metabolism via the spatial compartmentalization of rate-limiting HMGCR enzymes at an inter-organelle contact site.

The Sustainability of Thailand’s Protected-Area System under Climate Change

Protected areas are the backbone of biodiversity conservation but vulnerable to climate change. Thailand has a large and well-planned protected area system, covering most remaining natural vegetation. A statistically derived global environmental stratification (GEnS) was used to predict changes in bioclimatic conditions across the protected area system for 2050 and 2070, based on projections from three CMIP5 earth system models and two representative concentration pathways (RCPs). Five bioclimatic zones were identified composed of 28 strata. Substantial spatial reorganization of bioclimates is projected in the next 50 years, even under RCP2.6, while under RCP8.5 the average upward shift for all zones by 2070 is 328–483 m and the coolest zone disappears with two models. Overall, 7.9–31.0% of Thailand’s land area will change zone by 2070, and 31.7–90.2% will change stratum. The consequences for biodiversity are less clear, particularly in the lowlands where the existing vegetation mosaic is determined largely by factors other than climate. Increasing connectivity of protected areas along temperature and rainfall gradients would allow species to migrate in response to climate change, but this will be difficult in much of Thailand. For isolated protected areas and species that cannot move fast enough, more active, species-specific interventions may be necessary.