ERC FUNDED PROJECTS

Massive stars dominate their surroundings during their short lifetimes, while their explosive deaths impact the chemical evolution and spatial cohesion of their hosts. After birth, their evolution is largely dictated by their ability to remove layers of hydrogen from their envelopes. Multiple lines of evidence are pointing to violent, episodic mass-loss events being responsible for removing a large part of the massive stellar envelope, especially in low-metallicity galaxies. Episodic mass loss, however, is not understood theoretically, neither accounted for in state-of-the-art models of stellar evolution, which has far-reaching consequences for many areas of astronomy. We aim to determine whether episodic mass loss is a dominant process in the evolution of the most massive stars by conducting the first extensive, multi-wavelength survey of evolved massive stars in the nearby Universe. The project hinges on the fact that mass-losing stars form dust and are bright in the mid-infrared. We plan to (i) derive physical parameters of a large sample of dusty, evolved targets and estimate the amount of ejected mass, (ii) constrain evolutionary models, (iii) quantify the duration and frequency of episodic mass loss as a function of metallicity. The approach involves applying machine-learning algorithms to existing multi-band and time-series photometry of luminous sources in ~25 nearby galaxies. Dusty, luminous evolved massive stars will thus be automatically classified and follow-up spectroscopy will be obtained for selected targets. Atmospheric and SED modeling will yield parameters and estimates of time-dependent mass loss for ~1000 luminous stars. The emerging trend for the ubiquity of episodic mass loss, if confirmed, will be key to understanding the explosive early Universe and will have profound consequences for low-metallicity stars, reionization, and the chemical evolution of galaxies.

1 128 750 €

Start date: 2018-09-01, End date: 2023-08-31

HIV/AIDS is one of the most destructive pandemics in human history, responsible for more than 25 million deaths. More than 30 million people live with limited or no access to therapeutic treatments, mainly due to the high cost of highly active antiretroviral therapies (HAART) and current diagnostic tests as well as due to the lack of basic infrastructure (e.g. lack of electricity, no trained personnel) that can support these tests. The need for innovative, inexpensive diagnostic instrumentation technology that can be used in resource-limited settings is immediate. While programs that offer free HAART are being implemented in resource-limited settings, no diagnostic tests are available for evaluating the efficacy of HAART provided for the reasons mentioned above. Efficient management of HAART requires monitoring the course of HIV infection over time. The World Health Organization (WHO) recommends the CD4 T-cell count test for monitoring the clinical status of HIV individuals in resource-limited settings. We propose to develop a portable, inexpensive, MEMS (MicroElectroMechanical Systems)-based, imaging system for counting the absolute number of CD4 cells from 1 l of whole blood. We use the term ‘imaging system’ to denote the different approach we follow for counting CD4 cells: rather the reading one by one singles cells (as it is done with flow cytometry), our system can image simultaneously thousands of individual cells, pre-assembled on the surface of a biochip. Although the proposed imaging system can replace current expensive cell counting instrumentation, our goal is to develop a system that can reach the end-user wherever limited infrastructure is present and no access to a hospital or clinic is possible. Such technology will not only enable to monitor the efficacy of an individual’s HAART in the developing world, but it will make more medicines available by identifying patients who need a treatment from patients who do not need it.

1 986 000 €

Start date: 2012-06-01, End date: 2017-05-31

Malignant pleural effusion (MPE) is a significant problem most commonly caused by adenocarcinomas. Although tumors involving the pleura vary in their ability to produce MPE, pathways critical for MPE formation are poorly defined. We have found that mouse tumors harboring mutant (”)KRas produce MPE in mice while tumors without ”KRas do not. LLC and MC38 lung and colon adenocarcinomas, potent inducers of MPE in syngeneic mice, harbor ”KRas that drives constitutive Ras and alternative nuclear factor (NF)-ºB signaling, inflammatory gene expression, and recruitment of specific myeloid cells to the pleural space. In contrast, mouse B16 melanoma and AE17 mesothelioma have wtKRas, lack constitutive Ras/alternative NF-º’ signaling, and are incapable of forming MPE. RNAi-mediated silencing of KRas in MC38 tumors abrogated MPE formation and Ras/alternative NF-º’ activation, while these phenomena were reconstituted in B16 tumors after KRas overexpression. We hypothesize that Ras-activating mutations drive the inflammatory phenotype of adenocarcinomas critical for MPE formation, which is characterized by Ras/alternative NF-ºB activation, inflammatory signalling to host vasculature/immune system, and recruitment of specific myeloid cells, and results in endothelial proliferation/leakiness. To test this hypothesis, we propose to: 1) define the relationship between Ras-activating mutations (RAM) and MPE formation; 2) identify tumor cell Ras-dependent signalling pathways and gene expression signature critical for MPE formation; 3) investigate the host response to tumor cells with RAM that results in MPE; and 4) target Ras and dependent signalling pathways as potential therapy for MPE. Studies will be performed using delivery of mouse/human tumors with/without RAM into the pleura of syngeneic/immunocompromized mice and are likely to yield new insights into the mechanisms of pleural tumor progression and to identify novel approaches to treatment of cancer patients with MPE.

1 995 000 €

Start date: 2011-04-01, End date: 2016-03-31

Necrosis contributes critically in devastating human pathologies such as stroke, ischemia, and age-associated neurodegenerative disorders. Ageing increases susceptibility to neurodegeneration, in diverse species ranging from the lowly nematode Caenorhabditis elegans to humans. The mechanisms that govern necrotic neurodegeneration and its modulation by ageing are poorly understood. Autophagy has been implicated in necrosis and neurodegeneration, both with pro-survival and a pro-death roles. Autophagic flux declines with age, while induction of autophagy enhances longevity under conditions such as low insulin/IGF1 signalling and dietary restriction, which extend lifespan across diverse taxa. Our recent findings indicate that organelle-specific autophagy, including mitophagy, pexophagy and nucleophagy, is an important, evolutionarily conserved, determinant of longevity. We propose to dissect the molecular underpinnings of neuron vulnerability to necrosis during ageing, focusing on cargo-specific macroautophagy. To this end, we will implement a multifaceted approach that combines the power and versatility of C. elegans genetics with advanced, in vivo neuronal imaging and microfluidics technology. Our objectives are fourfold. First, we will monitor autophagic flux of organellar cargo, during neurodegeneration, under conditions that alter lifespan and identify mediators of organelle-specific autophagy in neurons. Second, we will conduct genome-wide screens for modifiers of age-inflicted neurodegeneration. Third, we will interrogate nematode models of human neurodegenerative disorders for organelle-specific autophagy and susceptibility to necrosis, upon manipulations that alter lifespan. Fourth, we will investigate the functional conservation of key mechanisms in mammalian models of neuronal necrosis. Together, these studies will deepen our understanding of age-related neurodegeneration and provide critical insights with broad relevance to human health and quality of life.

2 254 109 €

Start date: 2017-01-01, End date: 2021-12-31