Project acronym AXIAL.EC
Project PRINCIPLES OF AXIAL POLARITY-DRIVEN VASCULAR PATTERNING
Researcher (PI) Claudio Franco
Host Institution (HI) INSTITUTO DE MEDICINA MOLECULAR JOAO LOBO ANTUNES
Call Details Starting Grant (StG), LS4, ERC-2015-STG
Summary The formation of a functional patterned vascular network is essential for development, tissue growth and organ physiology. Several human vascular disorders arise from the mis-patterning of blood vessels, such as arteriovenous malformations, aneurysms and diabetic retinopathy. Although blood flow is recognised as a stimulus for vascular patterning, very little is known about the molecular mechanisms that regulate endothelial cell behaviour in response to flow and promote vascular patterning.
Recently, we uncovered that endothelial cells migrate extensively in the immature vascular network, and that endothelial cells polarise against the blood flow direction. Here, we put forward the hypothesis that vascular patterning is dependent on the polarisation and migration of endothelial cells against the flow direction, in a continuous flux of cells going from low-shear stress to high-shear stress regions. We will establish new reporter mouse lines to observe and manipulate endothelial polarity in vivo in order to investigate how polarisation and coordination of endothelial cells movements are orchestrated to generate vascular patterning. We will manipulate cell polarity using mouse models to understand the importance of cell polarisation in vascular patterning. Also, using a unique zebrafish line allowing analysis of endothelial cell polarity, we will perform a screen to identify novel regulators of vascular patterning. Finally, we will explore the hypothesis that defective flow-dependent endothelial polarisation underlies arteriovenous malformations using two genetic models.
This integrative approach, based on high-resolution imaging and unique experimental models, will provide a unifying model defining the cellular and molecular principles involved in vascular patterning. Given the physiological relevance of vascular patterning in health and disease, this research plan will set the basis for the development of novel clinical therapies targeting vascular disorders.
Summary
The formation of a functional patterned vascular network is essential for development, tissue growth and organ physiology. Several human vascular disorders arise from the mis-patterning of blood vessels, such as arteriovenous malformations, aneurysms and diabetic retinopathy. Although blood flow is recognised as a stimulus for vascular patterning, very little is known about the molecular mechanisms that regulate endothelial cell behaviour in response to flow and promote vascular patterning.
Recently, we uncovered that endothelial cells migrate extensively in the immature vascular network, and that endothelial cells polarise against the blood flow direction. Here, we put forward the hypothesis that vascular patterning is dependent on the polarisation and migration of endothelial cells against the flow direction, in a continuous flux of cells going from low-shear stress to high-shear stress regions. We will establish new reporter mouse lines to observe and manipulate endothelial polarity in vivo in order to investigate how polarisation and coordination of endothelial cells movements are orchestrated to generate vascular patterning. We will manipulate cell polarity using mouse models to understand the importance of cell polarisation in vascular patterning. Also, using a unique zebrafish line allowing analysis of endothelial cell polarity, we will perform a screen to identify novel regulators of vascular patterning. Finally, we will explore the hypothesis that defective flow-dependent endothelial polarisation underlies arteriovenous malformations using two genetic models.
This integrative approach, based on high-resolution imaging and unique experimental models, will provide a unifying model defining the cellular and molecular principles involved in vascular patterning. Given the physiological relevance of vascular patterning in health and disease, this research plan will set the basis for the development of novel clinical therapies targeting vascular disorders.
Max ERC Funding
1 618 750 €
Duration
Start date: 2016-09-01, End date: 2021-08-31
Project acronym CFS modelling
Project Chromosomal Common Fragile Sites: Unravelling their biological functions and the basis of their instability
Researcher (PI) Andres Joaquin Lopez-Contreras
Host Institution (HI) KOBENHAVNS UNIVERSITET
Call Details Starting Grant (StG), LS4, ERC-2015-STG
Summary Cancer and other diseases are driven by genomic alterations initiated by DNA breaks. Within our genomes, some regions are particularly prone to breakage, and these are known as common fragile sites (CFSs). CFSs are present in every person and are frequently sites of oncogenic chromosomal rearrangements. Intriguingly, despite their fragility, many CFSs are well conserved through evolution, suggesting that these regions have important physiological functions that remain elusive. My previous background in genome editing, proteomics and replication-born DNA damage has given me the tools to propose an ambitious and comprehensive plan that tackles fundamental questions on the biology of CFSs. First, we will perform a systematic analysis of the function of CFSs. Most of the CFSs contain very large genes, which has made technically difficult to dissect whether the CFS role is due to the locus itself or to the encoded gene product. However, the emergence of the CRISPR/Cas9 technology now enables the study of CFSs on a more systematic basis. We will pioneer the engineering of mammalian models harbouring large deletions at CFS loci to investigate their physiological functions at the cellular and organism levels. For those CFSs that contain genes, the cDNAs will be re-introduced at a distal locus. Using this strategy, we will be able to achieve the first comprehensive characterization of CFS roles. Second, we will develop novel targeted approaches to interrogate the chromatin-bound proteome of CFSs and its dynamics during DNA replication. Finally, and given that CFS fragility is influenced both by cell cycle checkpoints and dNTP availability, we will use mouse models to study the impact of ATR/CHK1 pathway and dNTP levels on CFS instability and cancer. Taken together, I propose an ambitious, yet feasible, project to functionally annotate and characterise these poorly understood regions of the human genome, with important potential implications for improving human health.
Summary
Cancer and other diseases are driven by genomic alterations initiated by DNA breaks. Within our genomes, some regions are particularly prone to breakage, and these are known as common fragile sites (CFSs). CFSs are present in every person and are frequently sites of oncogenic chromosomal rearrangements. Intriguingly, despite their fragility, many CFSs are well conserved through evolution, suggesting that these regions have important physiological functions that remain elusive. My previous background in genome editing, proteomics and replication-born DNA damage has given me the tools to propose an ambitious and comprehensive plan that tackles fundamental questions on the biology of CFSs. First, we will perform a systematic analysis of the function of CFSs. Most of the CFSs contain very large genes, which has made technically difficult to dissect whether the CFS role is due to the locus itself or to the encoded gene product. However, the emergence of the CRISPR/Cas9 technology now enables the study of CFSs on a more systematic basis. We will pioneer the engineering of mammalian models harbouring large deletions at CFS loci to investigate their physiological functions at the cellular and organism levels. For those CFSs that contain genes, the cDNAs will be re-introduced at a distal locus. Using this strategy, we will be able to achieve the first comprehensive characterization of CFS roles. Second, we will develop novel targeted approaches to interrogate the chromatin-bound proteome of CFSs and its dynamics during DNA replication. Finally, and given that CFS fragility is influenced both by cell cycle checkpoints and dNTP availability, we will use mouse models to study the impact of ATR/CHK1 pathway and dNTP levels on CFS instability and cancer. Taken together, I propose an ambitious, yet feasible, project to functionally annotate and characterise these poorly understood regions of the human genome, with important potential implications for improving human health.
Max ERC Funding
1 499 711 €
Duration
Start date: 2016-05-01, End date: 2021-04-30
Project acronym nextDART
Project Next-generation Detection of Antigen Responsive T-cells
Researcher (PI) Sine Reker Hadrup
Host Institution (HI) DANMARKS TEKNISKE UNIVERSITET
Call Details Starting Grant (StG), LS6, ERC-2015-STG
Summary Our current ability to map T-cell reactivity to certain molecular patterns poorly matches the huge diversity of T-cell recognition in humans. Our immune system holds approximately 107 different T-cell populations patrolling our body to fight intruding pathogens. Current state-of-the-art T-cell detection enables the detection of 45 different T-cell specificities in a given sample. Therefore comprehensive analysis of T-cell recognition against intruding pathogens, auto-immune attacked tissues or cancer is virtually impossible.
To gain insight into immune recognition and allow careful target selection for disease intervention, also on a personalized basis, we need technologies that allow detection of vast numbers of different T-cell specificities with high sensitivity in small biological samples.
I propose here a new technology based on multimerised peptide-major histocompatibility complex I (MHC I) reagents that allow detection of >1000 different T-cell specificities with high sensitivity in small biological samples. I will use this new technology to gain insight into the T-cell recognition of cancer cells and specifically assess the impact of mutation-derived neo-epitopes on T cell-mediated cancer cell recognition.
A major advantage of this new technology relates to the ability of coupling the antigen specificity to the T-cell receptor sequence. This will enable us to retrieve information about T-cell receptor sequences coupled with their molecular recognition pattern, and develop a predictor of binding between T-cell receptors and specific epitopes. It will ultimately enable us to predict immune recognition based on T-cell receptor sequences, and has the potential to truly transform our understanding of T cell immunology.
Advances in our understanding of T cell immunology are leading to massive advances in the treatment of cancer. The technologies I propose to develop and validate will greatly aid this process and have application for all immune related diseases.
Summary
Our current ability to map T-cell reactivity to certain molecular patterns poorly matches the huge diversity of T-cell recognition in humans. Our immune system holds approximately 107 different T-cell populations patrolling our body to fight intruding pathogens. Current state-of-the-art T-cell detection enables the detection of 45 different T-cell specificities in a given sample. Therefore comprehensive analysis of T-cell recognition against intruding pathogens, auto-immune attacked tissues or cancer is virtually impossible.
To gain insight into immune recognition and allow careful target selection for disease intervention, also on a personalized basis, we need technologies that allow detection of vast numbers of different T-cell specificities with high sensitivity in small biological samples.
I propose here a new technology based on multimerised peptide-major histocompatibility complex I (MHC I) reagents that allow detection of >1000 different T-cell specificities with high sensitivity in small biological samples. I will use this new technology to gain insight into the T-cell recognition of cancer cells and specifically assess the impact of mutation-derived neo-epitopes on T cell-mediated cancer cell recognition.
A major advantage of this new technology relates to the ability of coupling the antigen specificity to the T-cell receptor sequence. This will enable us to retrieve information about T-cell receptor sequences coupled with their molecular recognition pattern, and develop a predictor of binding between T-cell receptors and specific epitopes. It will ultimately enable us to predict immune recognition based on T-cell receptor sequences, and has the potential to truly transform our understanding of T cell immunology.
Advances in our understanding of T cell immunology are leading to massive advances in the treatment of cancer. The technologies I propose to develop and validate will greatly aid this process and have application for all immune related diseases.
Max ERC Funding
1 499 070 €
Duration
Start date: 2016-06-01, End date: 2021-05-31
Project acronym STC
Project Synaptic Tagging and Capture: From Synapses to Behavior
Researcher (PI) Sayyed Mohammad Sadegh Nabavi
Host Institution (HI) AARHUS UNIVERSITET
Call Details Starting Grant (StG), LS5, ERC-2015-STG
Summary It is shown that long-term potentiation (LTP) is the cellular basis of memory formation. However, since all but small fraction of memories are forgotten, LTP has been further divided into early LTP (e-LTP), the mechanism by which short-term memories are formed, and a more stable late LTP (L-LTP), by which long-term memories are formed. Remarkably, it has been shown that an e-LTP can be stabilized if it is preceded or followed by heterosynaptic L-LTP.
According to Synaptic Tagging and Capture (STC) hypothesis, e-LTP is stabilized by capturing proteins that are made by L-LTP induction. The model proposes that this mechanism underlies the formation of late associative memory, where the stability of a memory is not only defined by the stimuli that induce the change but also by events happening before and after these stimuli. As such, the model explicitly predicts that a short-term memory can be stabilized by inducing heterosynaptic L-LTP.
In this grant, I will put this hypothesis into test. Specifically, I will test two explicit predictions of STC model: 1) A naturally formed short-term memory can be stabilized by induction of heterosynaptic L-LTP. 2) This stabilization is caused by the protein synthesis feature of L-LTP. To do this, using optogenetics, I will engineer a short-term memory in auditory fear circuit, in which an animal transiently associates a foot shock to a tone. Subsequently, I will examine if optogenetic delivery of L-LTP to the visual inputs converging on the same population of neurons in the amygdala will stabilize the short-term tone fear memory.
To be able to engineer natural memory by manipulating synaptic plasticity I will develop two systems: 1) A two-color optical activation system which permits selective manipulation of distinct neuronal populations with precise temporal and spatial resolution; 2) An inducible and activity-dependent expression system by which those neurons that are activated by a natural stimulus will be optically tagged.
Summary
It is shown that long-term potentiation (LTP) is the cellular basis of memory formation. However, since all but small fraction of memories are forgotten, LTP has been further divided into early LTP (e-LTP), the mechanism by which short-term memories are formed, and a more stable late LTP (L-LTP), by which long-term memories are formed. Remarkably, it has been shown that an e-LTP can be stabilized if it is preceded or followed by heterosynaptic L-LTP.
According to Synaptic Tagging and Capture (STC) hypothesis, e-LTP is stabilized by capturing proteins that are made by L-LTP induction. The model proposes that this mechanism underlies the formation of late associative memory, where the stability of a memory is not only defined by the stimuli that induce the change but also by events happening before and after these stimuli. As such, the model explicitly predicts that a short-term memory can be stabilized by inducing heterosynaptic L-LTP.
In this grant, I will put this hypothesis into test. Specifically, I will test two explicit predictions of STC model: 1) A naturally formed short-term memory can be stabilized by induction of heterosynaptic L-LTP. 2) This stabilization is caused by the protein synthesis feature of L-LTP. To do this, using optogenetics, I will engineer a short-term memory in auditory fear circuit, in which an animal transiently associates a foot shock to a tone. Subsequently, I will examine if optogenetic delivery of L-LTP to the visual inputs converging on the same population of neurons in the amygdala will stabilize the short-term tone fear memory.
To be able to engineer natural memory by manipulating synaptic plasticity I will develop two systems: 1) A two-color optical activation system which permits selective manipulation of distinct neuronal populations with precise temporal and spatial resolution; 2) An inducible and activity-dependent expression system by which those neurons that are activated by a natural stimulus will be optically tagged.
Max ERC Funding
1 500 000 €
Duration
Start date: 2016-04-01, End date: 2021-03-31
Project acronym SynapticMitochondria
Project Quality Control and Maintenance of Synaptic Mitochondria
Researcher (PI) Vanessa Alexandra Dos Santos Morais Epifânio
Host Institution (HI) INSTITUTO DE MEDICINA MOLECULAR JOAO LOBO ANTUNES
Call Details Starting Grant (StG), LS5, ERC-2015-STG
Summary Mitochondria at the synapse have a pivotal role in neurotransmitter release, but almost nothing is known about synaptic mitochondria composition or specific functions. Synaptic mitochondria compared to mitochondria in other cells, need to cope with increased calcium load, more oxidative stress, and high demands of energy generation during synaptic activity. My hypothesis is that synaptic mitochondria have acquired specific mechanisms to manage local stress and that disruption of these mechanisms contributes to neurodegeneration.
How mitochondria sense their dysfunction is unclear. Even more intriguing is the question how they decide whether their failure should lead to removal of the organelle or dismissal of the complete neuron via cell death. We anticipate that these decisions are not only operational during disease, but might constitute a fundamental mechanism relevant for maintenance of synaptic activity and establishment of new synapses.
Recent studies have revealed several genes implicated in neurodegenerative disorders involved in mitochondrial maintenance. However the function of these genes at the synapse, where the initial damage occurs, remains to be clarified. These genes provide excellent starting points to decipher the molecular mechanisms discussed above. Furthermore I propose to use proteomic approaches to identify the protein fingerprint of synaptic mitochondria and to compare them to mitochondria from other tissues. I plan to identify key players of the proposed regulatory pathways involved in intrinsic mitochondria quality control. In a complimentary approach, I will exploit our findings and use in vitro and in vivo experimental approaches to measure mitochondrial function of synaptic versus non-synaptic mitochondria and the relevance of those changes for synaptic function. Our work will unravel the specific properties of synaptic mitochondria and provide much needed insight in their hypothesized predominant role in neurodegenerative disorders.
Summary
Mitochondria at the synapse have a pivotal role in neurotransmitter release, but almost nothing is known about synaptic mitochondria composition or specific functions. Synaptic mitochondria compared to mitochondria in other cells, need to cope with increased calcium load, more oxidative stress, and high demands of energy generation during synaptic activity. My hypothesis is that synaptic mitochondria have acquired specific mechanisms to manage local stress and that disruption of these mechanisms contributes to neurodegeneration.
How mitochondria sense their dysfunction is unclear. Even more intriguing is the question how they decide whether their failure should lead to removal of the organelle or dismissal of the complete neuron via cell death. We anticipate that these decisions are not only operational during disease, but might constitute a fundamental mechanism relevant for maintenance of synaptic activity and establishment of new synapses.
Recent studies have revealed several genes implicated in neurodegenerative disorders involved in mitochondrial maintenance. However the function of these genes at the synapse, where the initial damage occurs, remains to be clarified. These genes provide excellent starting points to decipher the molecular mechanisms discussed above. Furthermore I propose to use proteomic approaches to identify the protein fingerprint of synaptic mitochondria and to compare them to mitochondria from other tissues. I plan to identify key players of the proposed regulatory pathways involved in intrinsic mitochondria quality control. In a complimentary approach, I will exploit our findings and use in vitro and in vivo experimental approaches to measure mitochondrial function of synaptic versus non-synaptic mitochondria and the relevance of those changes for synaptic function. Our work will unravel the specific properties of synaptic mitochondria and provide much needed insight in their hypothesized predominant role in neurodegenerative disorders.
Max ERC Funding
1 300 000 €
Duration
Start date: 2016-09-01, End date: 2021-08-31
Project acronym TransGen RNA
Project Transgenerational regulation of glucose metabolism by noncoding RNAs
Researcher (PI) Jan-Wilhelm Kornfeld
Host Institution (HI) SYDDANSK UNIVERSITET
Call Details Starting Grant (StG), LS4, ERC-2015-STG
Summary Obesity and T2D affect large populations and cause a decline in life expectancy if untreated. The pandemic proportion of obesity and inaptitude of anti-obesity approaches reflect our limited understanding of its complex environmental and genetic etiology. Genome-wide association studies revealed that disease-associated risk variants are often situated in those 98% of the genome not encoding for proteins. This noncoding genomic space yet does not reflect ‘Junk DNA’ but gives rise to >10,000 noncoding RNAs like microRNAs and long, noncoding RNAs (lncRNAs) that implicated in control of glucose metabolism and energy homeostasis also by the applicant (Kornfeld et al. Nature 2013).
LncRNAs were paraphrased as 'Dark matter of the genome' due to their tissue-specific and dynamic expression that contrast their poorly understood role in gene regulation. In the 1st part of this proposal, we ask if lncRNAs regulate glucose metabolism and are involved in the obesity-associated dysregulation of insulin signaling in the liver, the major glucoregulatory organ in mammals. Using RNA-Seq and novel lncRNA prediction algorithms, we observed that obesity alters expression of 28 annotated and 15 hitherto unknown lncRNAs in two mouse models of obesity. To identify lncRNAs causally controlling glucose metabolism, we established a siRNA screening system that allows functional interrogation of >650 lncRNAs. These in vitro findings serve as entry for the generation of lncRNA knockout mice that are metabolically phenotyped. In the 2nd part, we hypothesize that germline ncRNAs could control the transgenerational consequences of paternal obesity as shown for lower organisms. This builds upon unpublished findings from our lab showing that obesity profoundly changes expression of germline ncRNAs. In-vitro fertilization and intergenerational breedings will trace the legacy of paternal obesity across generations and reveal ncRNAs involved in this ‘Lamarckian’ control of glucose metabolism.
Summary
Obesity and T2D affect large populations and cause a decline in life expectancy if untreated. The pandemic proportion of obesity and inaptitude of anti-obesity approaches reflect our limited understanding of its complex environmental and genetic etiology. Genome-wide association studies revealed that disease-associated risk variants are often situated in those 98% of the genome not encoding for proteins. This noncoding genomic space yet does not reflect ‘Junk DNA’ but gives rise to >10,000 noncoding RNAs like microRNAs and long, noncoding RNAs (lncRNAs) that implicated in control of glucose metabolism and energy homeostasis also by the applicant (Kornfeld et al. Nature 2013).
LncRNAs were paraphrased as 'Dark matter of the genome' due to their tissue-specific and dynamic expression that contrast their poorly understood role in gene regulation. In the 1st part of this proposal, we ask if lncRNAs regulate glucose metabolism and are involved in the obesity-associated dysregulation of insulin signaling in the liver, the major glucoregulatory organ in mammals. Using RNA-Seq and novel lncRNA prediction algorithms, we observed that obesity alters expression of 28 annotated and 15 hitherto unknown lncRNAs in two mouse models of obesity. To identify lncRNAs causally controlling glucose metabolism, we established a siRNA screening system that allows functional interrogation of >650 lncRNAs. These in vitro findings serve as entry for the generation of lncRNA knockout mice that are metabolically phenotyped. In the 2nd part, we hypothesize that germline ncRNAs could control the transgenerational consequences of paternal obesity as shown for lower organisms. This builds upon unpublished findings from our lab showing that obesity profoundly changes expression of germline ncRNAs. In-vitro fertilization and intergenerational breedings will trace the legacy of paternal obesity across generations and reveal ncRNAs involved in this ‘Lamarckian’ control of glucose metabolism.
Max ERC Funding
1 344 498 €
Duration
Start date: 2016-05-01, End date: 2021-04-30
Project acronym ZPR
Project The Pancreas Regulome: From causality to prediction of non-coding mutations in human pancreatic diseases
Researcher (PI) José Carlos Ribeiro Bessa
Host Institution (HI) INSTITUTO DE BIOLOGIA MOLECULAR E CELULAR-IBMC
Call Details Starting Grant (StG), LS2, ERC-2015-STG
Summary Several human pancreatic diseases have been characterized, being the diabetes the most common. Like others, this genetic disease is related to disrupted non-coding cis-regulatory elements (CREs) that culminate in altered gene expression. Although Genome Wide Association Studies support this hypothesis, it’s still unclear how mutations on CREs contribute to disease. The translation from the “non-coding code” to phenotype is an exciting and unexplored field that we will approach in this project with the help of the zebrafish as a suitable animal model. We aim to uncover the implications of the disruption of pancreas CREs and how they contribute to diabetes in vivo. For this we will study transcriptional regulation of genes in zebrafish. The similarities between zebrafish and mammal pancreas and the evolutionary conservation of pancreas transcription factors (TF) make it an excellent model to approach and study this disease. In this project we will characterize the zebrafish insulin producing beta-cell regulome, by determining the active CREs in this cell type and their bound TFs. Then we will compare this information with a similar dataset recently available for human beta-cells, to define functional orthologs in these species. Selected CREs will be tested by in vivo gene reporter assays in zebrafish, focusing on those functionally equivalent to human CREs where risk alleles have been associated with diabetes or those regulating genes involved in diabetes. Later these CREs will be mutated in the zebrafish genome to validate their contribution to diabetes. Finally we will translate this to predict new human disease-associated CREs by focusing on the regulatory landscape of diabetes-associated genes, without the need of having countless patients to uncover them. With this project we will create a model system that will allow the identification of new diabetes-associated CREs, which might have a great impact in clinical management of this epidemic disease.
Summary
Several human pancreatic diseases have been characterized, being the diabetes the most common. Like others, this genetic disease is related to disrupted non-coding cis-regulatory elements (CREs) that culminate in altered gene expression. Although Genome Wide Association Studies support this hypothesis, it’s still unclear how mutations on CREs contribute to disease. The translation from the “non-coding code” to phenotype is an exciting and unexplored field that we will approach in this project with the help of the zebrafish as a suitable animal model. We aim to uncover the implications of the disruption of pancreas CREs and how they contribute to diabetes in vivo. For this we will study transcriptional regulation of genes in zebrafish. The similarities between zebrafish and mammal pancreas and the evolutionary conservation of pancreas transcription factors (TF) make it an excellent model to approach and study this disease. In this project we will characterize the zebrafish insulin producing beta-cell regulome, by determining the active CREs in this cell type and their bound TFs. Then we will compare this information with a similar dataset recently available for human beta-cells, to define functional orthologs in these species. Selected CREs will be tested by in vivo gene reporter assays in zebrafish, focusing on those functionally equivalent to human CREs where risk alleles have been associated with diabetes or those regulating genes involved in diabetes. Later these CREs will be mutated in the zebrafish genome to validate their contribution to diabetes. Finally we will translate this to predict new human disease-associated CREs by focusing on the regulatory landscape of diabetes-associated genes, without the need of having countless patients to uncover them. With this project we will create a model system that will allow the identification of new diabetes-associated CREs, which might have a great impact in clinical management of this epidemic disease.
Max ERC Funding
1 497 520 €
Duration
Start date: 2016-06-01, End date: 2021-05-31
