Project acronym aCROBAT
Project Circadian Regulation Of Brown Adipose Thermogenesis
Researcher (PI) Zachary Philip Gerhart-Hines
Host Institution (HI) KOBENHAVNS UNIVERSITET
Call Details Starting Grant (StG), LS4, ERC-2014-STG
Summary Obesity and diabetes have reached pandemic proportions and new therapeutic strategies are critically needed. Brown adipose tissue (BAT), a major source of heat production, possesses significant energy-dissipating capacity and therefore represents a promising target to use in combating these diseases. Recently, I discovered a novel link between circadian rhythm and thermogenic stress in the control of the conserved, calorie-burning functions of BAT. Circadian and thermogenic signaling to BAT incorporates blood-borne hormonal and nutrient cues with direct neuronal input. Yet how these responses coordinately shape BAT energy-expending potential through the regulation of cell surface receptors, metabolic enzymes, and transcriptional effectors is still not understood. My primary goal is to investigate this previously unappreciated network of crosstalk that allows mammals to effectively orchestrate daily rhythms in BAT metabolism, while maintaining their ability to adapt to abrupt changes in energy demand. My group will address this question using gain and loss-of-function in vitro and in vivo studies, newly-generated mouse models, customized physiological phenotyping, and cutting-edge advances in next generation RNA sequencing and mass spectrometry. Preliminary, small-scale validations of our methodologies have already yielded a number of novel candidates that may drive key facets of BAT metabolism. Additionally, we will extend our circadian and thermogenic studies into humans to evaluate the translational potential. Our results will advance the fundamental understanding of how daily oscillations in bioenergetic networks establish a framework for the anticipation of and adaptation to environmental challenges. Importantly, we expect that these mechanistic insights will reveal pharmacological targets through which we can unlock evolutionary constraints and harness the energy-expending potential of BAT for the prevention and treatment of obesity and diabetes.
Summary
Obesity and diabetes have reached pandemic proportions and new therapeutic strategies are critically needed. Brown adipose tissue (BAT), a major source of heat production, possesses significant energy-dissipating capacity and therefore represents a promising target to use in combating these diseases. Recently, I discovered a novel link between circadian rhythm and thermogenic stress in the control of the conserved, calorie-burning functions of BAT. Circadian and thermogenic signaling to BAT incorporates blood-borne hormonal and nutrient cues with direct neuronal input. Yet how these responses coordinately shape BAT energy-expending potential through the regulation of cell surface receptors, metabolic enzymes, and transcriptional effectors is still not understood. My primary goal is to investigate this previously unappreciated network of crosstalk that allows mammals to effectively orchestrate daily rhythms in BAT metabolism, while maintaining their ability to adapt to abrupt changes in energy demand. My group will address this question using gain and loss-of-function in vitro and in vivo studies, newly-generated mouse models, customized physiological phenotyping, and cutting-edge advances in next generation RNA sequencing and mass spectrometry. Preliminary, small-scale validations of our methodologies have already yielded a number of novel candidates that may drive key facets of BAT metabolism. Additionally, we will extend our circadian and thermogenic studies into humans to evaluate the translational potential. Our results will advance the fundamental understanding of how daily oscillations in bioenergetic networks establish a framework for the anticipation of and adaptation to environmental challenges. Importantly, we expect that these mechanistic insights will reveal pharmacological targets through which we can unlock evolutionary constraints and harness the energy-expending potential of BAT for the prevention and treatment of obesity and diabetes.
Max ERC Funding
1 497 008 €
Duration
Start date: 2015-05-01, End date: 2020-04-30
Project acronym AgeingStemCellFate
Project The Role of Ectopic Adipocyte Progenitors in Age-related Stem Cell Dysfunction, Systemic Inflammation, and Metabolic Disease
Researcher (PI) Tim Julius Schulz
Host Institution (HI) DEUTSCHES INSTITUT FUER ERNAEHRUNGSFORSCHUNG POTSDAM REHBRUECKE
Call Details Starting Grant (StG), LS4, ERC-2012-StG_20111109
Summary Ageing is accompanied by ectopic white adipose tissue depositions in skeletal muscle and other anatomical locations, such as brown adipose tissue and the bone marrow. Ectopic fat accrual contributes to organ dysfunction, systemic insulin resistance, and other perturbations that have been implicated in metabolic diseases.
This research proposal aims to identify the regulatory cues that control the development of ectopic progenitor cells that give rise to this type of fat. It is hypothesized that an age-related dysfunction of the stem cell niche leads to an imbalance between (1) tissue-specific stem cells and (2) fibroblast-like, primarily adipogenic progenitors that reside within many tissues. Novel methodologies that assess stem/progenitor cell characteristics on the single cell level will be combined with animal models of lineage tracing to determine the developmental origin of these adipogenic progenitors and processes that regulate their function.
Notch signalling is a key signalling pathway that relies on direct physical interaction to control stem cell fate. It is proposed that impaired Notch activity contributes to the phenotypical shift of precursor cell distribution in aged tissues.
Lastly, the role of the stem cell niche in ectopic adipocyte progenitor formation will be analyzed. External signals originating from the surrounding niche cells regulate the developmental fate of stem cells. Secreted factors and their role in the formation of ectopic adipocyte precursors during senescence will be identified using a combination of biochemical and systems biology approaches.
Accomplishment of these studies will help to understand the basic processes of stem cell ageing and identify mechanisms of age-related functional decline in tissue regeneration. By targeting the population of tissue-resident adipogenic progenitor cells, therapeutic strategies could be developed to counteract metabolic complications associated with the ageing process.
Summary
Ageing is accompanied by ectopic white adipose tissue depositions in skeletal muscle and other anatomical locations, such as brown adipose tissue and the bone marrow. Ectopic fat accrual contributes to organ dysfunction, systemic insulin resistance, and other perturbations that have been implicated in metabolic diseases.
This research proposal aims to identify the regulatory cues that control the development of ectopic progenitor cells that give rise to this type of fat. It is hypothesized that an age-related dysfunction of the stem cell niche leads to an imbalance between (1) tissue-specific stem cells and (2) fibroblast-like, primarily adipogenic progenitors that reside within many tissues. Novel methodologies that assess stem/progenitor cell characteristics on the single cell level will be combined with animal models of lineage tracing to determine the developmental origin of these adipogenic progenitors and processes that regulate their function.
Notch signalling is a key signalling pathway that relies on direct physical interaction to control stem cell fate. It is proposed that impaired Notch activity contributes to the phenotypical shift of precursor cell distribution in aged tissues.
Lastly, the role of the stem cell niche in ectopic adipocyte progenitor formation will be analyzed. External signals originating from the surrounding niche cells regulate the developmental fate of stem cells. Secreted factors and their role in the formation of ectopic adipocyte precursors during senescence will be identified using a combination of biochemical and systems biology approaches.
Accomplishment of these studies will help to understand the basic processes of stem cell ageing and identify mechanisms of age-related functional decline in tissue regeneration. By targeting the population of tissue-resident adipogenic progenitor cells, therapeutic strategies could be developed to counteract metabolic complications associated with the ageing process.
Max ERC Funding
1 496 444 €
Duration
Start date: 2013-03-01, End date: 2018-02-28
Project acronym ALK7
Project Metabolic control by the TGF-² superfamily receptor ALK7: A novel regulator of insulin secretion, fat accumulation and energy balance
Researcher (PI) Carlos Ibanez
Host Institution (HI) KAROLINSKA INSTITUTET
Call Details Advanced Grant (AdG), LS4, ERC-2008-AdG
Summary The aim of this proposal is to understand a novel regulatory signaling network controlling insulin secretion, fat accumulation and energy balance centered around selected components of the TGF-² signaling system, including Activins A and B, GDF-3 and their receptors ALK7 and ALK4. Recent results from my laboratory indicate that these molecules are part of paracrine signaling networks that control important functions in pancreatic islets and adipose tissue through feedback inhibition and feed-forward regulation. These discoveries have open up a new research area with important implications for the understanding of metabolic networks and the treatment of human metabolic syndromes, such as diabetes and obesity.
To drive progress in this new research area beyond the state-of-the-art it is proposed to: i) Elucidate the molecular mechanisms by which Activins regulate Ca2+ influx and insulin secretion in pancreatic ²-cells; ii) Elucidate the molecular mechanisms underlying the effects of GDF-3 on adipocyte metabolism, turnover and fat accumulation; iii) Investigate the interplay between insulin levels and fat deposition in the development of insulin resistance using mutant mice lacking Activin B and GDF-3; iv) Investigate tissue-specific contributions of ALK7 and ALK4 signaling to metabolic control by generating and characterizing conditional mutant mice; v) Investigate the effects of specific and reversible inactivation of ALK7 and ALK4 on metabolic regulation using a novel chemical-genetic approach based on analog-sensitive alleles.
This is research of a high-gain/high-risk nature. It is posed to open unique opportunities for further exploration of complex metabolic networks. The development of drugs capable of enhancing insulin secretion, limiting fat accumulation and ameliorating diet-induced obesity by targeting components of the ALK7 signaling network will find a strong rationale in the results of the proposed work.
Summary
The aim of this proposal is to understand a novel regulatory signaling network controlling insulin secretion, fat accumulation and energy balance centered around selected components of the TGF-² signaling system, including Activins A and B, GDF-3 and their receptors ALK7 and ALK4. Recent results from my laboratory indicate that these molecules are part of paracrine signaling networks that control important functions in pancreatic islets and adipose tissue through feedback inhibition and feed-forward regulation. These discoveries have open up a new research area with important implications for the understanding of metabolic networks and the treatment of human metabolic syndromes, such as diabetes and obesity.
To drive progress in this new research area beyond the state-of-the-art it is proposed to: i) Elucidate the molecular mechanisms by which Activins regulate Ca2+ influx and insulin secretion in pancreatic ²-cells; ii) Elucidate the molecular mechanisms underlying the effects of GDF-3 on adipocyte metabolism, turnover and fat accumulation; iii) Investigate the interplay between insulin levels and fat deposition in the development of insulin resistance using mutant mice lacking Activin B and GDF-3; iv) Investigate tissue-specific contributions of ALK7 and ALK4 signaling to metabolic control by generating and characterizing conditional mutant mice; v) Investigate the effects of specific and reversible inactivation of ALK7 and ALK4 on metabolic regulation using a novel chemical-genetic approach based on analog-sensitive alleles.
This is research of a high-gain/high-risk nature. It is posed to open unique opportunities for further exploration of complex metabolic networks. The development of drugs capable of enhancing insulin secretion, limiting fat accumulation and ameliorating diet-induced obesity by targeting components of the ALK7 signaling network will find a strong rationale in the results of the proposed work.
Max ERC Funding
2 462 154 €
Duration
Start date: 2009-04-01, End date: 2014-03-31
Project acronym AltCheM
Project In vivo functional screens to decipher mechanisms of stochastically- and mutationally-induced chemoresistance in Acute Myeloid Leukemia
Researcher (PI) Alexandre PUISSANT
Host Institution (HI) INSTITUT NATIONAL DE LA SANTE ET DE LA RECHERCHE MEDICALE
Call Details Starting Grant (StG), LS4, ERC-2017-STG
Summary Acute Myeloid Leukemia (AML), the most common leukemia diagnosed in adults, represents the paradigm of resistance to front-line therapies in hematology. Indeed, AML is so genetically complex that only few targeted therapies are currently tested in this disease and chemotherapy remains the only standard treatment for AML since the past four decades. Despite an initial sustained remission achieved by chemotherapeutic agents, almost all patients relapse with a chemoresistant minimal residual disease (MRD). The goal of my proposal is to characterize the still poorly understood biological mechanisms underlying persistence and emergence of MRD.
MRD is the consequence of the re-expansion of leukemia-initiating cells that are intrinsically more resistant to chemotherapy. This cell fraction may be stochastically more prone to survive front-line therapy regardless of their mutational status (the stochastic model), or genetically predetermined to resist by virtue of a collection of chemoprotective mutations (the mutational model).
I have already generated in mice, by consecutive rounds of chemotherapy, a stochastic MLL-AF9-driven chemoresistance model that I examined by RNA-sequencing. I will pursue the comprehensive cell autonomous and cell non-autonomous characterization of this chemoresistant AML disease using whole-exome and ChIP-sequencing.
To establish a mutationally-induced chemoresistant mouse model, I will conduct an innovative in vivo screen using pooled mutant open reading frame and shRNA libraries in order to predict which combinations of mutations, among those already known in AML, actively promote chemoresistance.
Finally, by combining genomic profiling and in vivo shRNA screening experiments, I will decipher the molecular mechanisms and identify the functional effectors of these two modes of resistance. Ultimately, I will then be able to firmly establish the fundamental relevance of the stochastic and/or the mutational model of chemoresistance for MRD genesis.
Summary
Acute Myeloid Leukemia (AML), the most common leukemia diagnosed in adults, represents the paradigm of resistance to front-line therapies in hematology. Indeed, AML is so genetically complex that only few targeted therapies are currently tested in this disease and chemotherapy remains the only standard treatment for AML since the past four decades. Despite an initial sustained remission achieved by chemotherapeutic agents, almost all patients relapse with a chemoresistant minimal residual disease (MRD). The goal of my proposal is to characterize the still poorly understood biological mechanisms underlying persistence and emergence of MRD.
MRD is the consequence of the re-expansion of leukemia-initiating cells that are intrinsically more resistant to chemotherapy. This cell fraction may be stochastically more prone to survive front-line therapy regardless of their mutational status (the stochastic model), or genetically predetermined to resist by virtue of a collection of chemoprotective mutations (the mutational model).
I have already generated in mice, by consecutive rounds of chemotherapy, a stochastic MLL-AF9-driven chemoresistance model that I examined by RNA-sequencing. I will pursue the comprehensive cell autonomous and cell non-autonomous characterization of this chemoresistant AML disease using whole-exome and ChIP-sequencing.
To establish a mutationally-induced chemoresistant mouse model, I will conduct an innovative in vivo screen using pooled mutant open reading frame and shRNA libraries in order to predict which combinations of mutations, among those already known in AML, actively promote chemoresistance.
Finally, by combining genomic profiling and in vivo shRNA screening experiments, I will decipher the molecular mechanisms and identify the functional effectors of these two modes of resistance. Ultimately, I will then be able to firmly establish the fundamental relevance of the stochastic and/or the mutational model of chemoresistance for MRD genesis.
Max ERC Funding
1 500 000 €
Duration
Start date: 2018-03-01, End date: 2023-02-28
Project acronym ALTER-brain
Project Metastasis-associated altered molecular patterns in the brain
Researcher (PI) Manuel VALIENTE
Host Institution (HI) FUNDACION CENTRO NACIONAL DE INVESTIGACIONES ONCOLOGICAS CARLOS III
Call Details Consolidator Grant (CoG), LS4, ERC-2019-COG
Summary Organ colonization is the most inefficient step of metastasis. However, once a few cancer cells manage to re-initiate their growth in the brain, the initial naïve microenvironment, which was not favouring and even actively limiting the number of potential metastasis initiating cells, is slowly rewired into a different ecosystem with pro-metastatic properties. In this project (ALTER-brain), we will study the biology of microenvironment reprogramming to explore innovative ways of treating metastasis.
Microenvironment reprogramming relies on altered molecular patterns that emerge in specific brain cell types simultaneously to the outgrowth of metastases. Dissecting the biology of these emerging patterns and their functional consequences could provide the basis to prevent metastasis but also to treat advances lesions. A key objective of ALTER-brain is the identification of newly established functional networks among previously non-connected components of the microenvironment that are critical to nurture tumour growth.
This research proposal focuses on metastasis in the brain given its rising incidence, poor therapeutic options and short survival rates upon diagnosis. ALTER-brain will use novel (i.e. spontaneous metastasis) and clinically relevant (i.e. relapse after therapy) experimental mouse models of brain metastasis combined with genetically engineered mice in which we will target specific components of the microenvironment. In addition, we will apply novel lineage tracing technologies to understand the origin and emerging heterogeneity of the reprogrammed microenvironment. Given the clinical relevance of our research, human brain metastasis provided by our clinical network will be used to validate key findings.
ALTER-brain will identify key principles underlying the unknown biology of the brain under a specific pathological pressure that might be translated to other highly prevalent disorders affecting this organ in the future.
Summary
Organ colonization is the most inefficient step of metastasis. However, once a few cancer cells manage to re-initiate their growth in the brain, the initial naïve microenvironment, which was not favouring and even actively limiting the number of potential metastasis initiating cells, is slowly rewired into a different ecosystem with pro-metastatic properties. In this project (ALTER-brain), we will study the biology of microenvironment reprogramming to explore innovative ways of treating metastasis.
Microenvironment reprogramming relies on altered molecular patterns that emerge in specific brain cell types simultaneously to the outgrowth of metastases. Dissecting the biology of these emerging patterns and their functional consequences could provide the basis to prevent metastasis but also to treat advances lesions. A key objective of ALTER-brain is the identification of newly established functional networks among previously non-connected components of the microenvironment that are critical to nurture tumour growth.
This research proposal focuses on metastasis in the brain given its rising incidence, poor therapeutic options and short survival rates upon diagnosis. ALTER-brain will use novel (i.e. spontaneous metastasis) and clinically relevant (i.e. relapse after therapy) experimental mouse models of brain metastasis combined with genetically engineered mice in which we will target specific components of the microenvironment. In addition, we will apply novel lineage tracing technologies to understand the origin and emerging heterogeneity of the reprogrammed microenvironment. Given the clinical relevance of our research, human brain metastasis provided by our clinical network will be used to validate key findings.
ALTER-brain will identify key principles underlying the unknown biology of the brain under a specific pathological pressure that might be translated to other highly prevalent disorders affecting this organ in the future.
Max ERC Funding
1 897 437 €
Duration
Start date: 2020-07-01, End date: 2025-06-30
Project acronym AN07AT
Project Understanding computational roles of new neurons generated in the adult hippocampus
Researcher (PI) Ayumu Tashiro
Host Institution (HI) NORGES TEKNISK-NATURVITENSKAPELIGE UNIVERSITET NTNU
Call Details Starting Grant (StG), LS4, ERC-2007-StG
Summary New neurons are continuously generated in certain regions of adult mammalian brain. One of those regions is the dentate gyrus, a subregion of hippocampus, which is essential for memory formation. Although these new neurons in the adult dentate gyrus are thought to have an important role in learning and memory, it is largely unclear how new neurons are involved in information processing and storage underlying memory. Because new neurons constitute a minor portion of intermingled local neuronal population, simple application of conventional techniques such as multi-unit extracellular recording and pharmacological lesion are not suitable for the functional analysis of new neurons. In this proposed research program, I will combine multi-unit recording and behavioral analysis with virus mediated, cell-type-specific genetic manipulation of neuronal activity, to investigate computational roles of new neurons in learning and memory. Specifically, I will determine: 1) specific memory processes that require new neurons, 2) dynamic patterns of activity that new neurons express during memory-related behavior, 3) influence of new neurons on their downstream structure. Further, based on the information obtained by these three lines of studies, we will establish causal relationship between specific memory-related behavior and specific pattern of activity in new neurons. Solving these issues will cooperatively provide important insight into the understanding of computational roles performed by adult neurogenesis. The information on the function of new neurons in normal brain could contribute to future development of efficient therapeutic strategy for a variety of brain disorders.
Summary
New neurons are continuously generated in certain regions of adult mammalian brain. One of those regions is the dentate gyrus, a subregion of hippocampus, which is essential for memory formation. Although these new neurons in the adult dentate gyrus are thought to have an important role in learning and memory, it is largely unclear how new neurons are involved in information processing and storage underlying memory. Because new neurons constitute a minor portion of intermingled local neuronal population, simple application of conventional techniques such as multi-unit extracellular recording and pharmacological lesion are not suitable for the functional analysis of new neurons. In this proposed research program, I will combine multi-unit recording and behavioral analysis with virus mediated, cell-type-specific genetic manipulation of neuronal activity, to investigate computational roles of new neurons in learning and memory. Specifically, I will determine: 1) specific memory processes that require new neurons, 2) dynamic patterns of activity that new neurons express during memory-related behavior, 3) influence of new neurons on their downstream structure. Further, based on the information obtained by these three lines of studies, we will establish causal relationship between specific memory-related behavior and specific pattern of activity in new neurons. Solving these issues will cooperatively provide important insight into the understanding of computational roles performed by adult neurogenesis. The information on the function of new neurons in normal brain could contribute to future development of efficient therapeutic strategy for a variety of brain disorders.
Max ERC Funding
1 991 743 €
Duration
Start date: 2009-01-01, End date: 2013-12-31
Project acronym ANGIOFAT
Project New mechanisms of angiogenesis modulators in switching between white and brown adipose tissues
Researcher (PI) Yihai Cao
Host Institution (HI) KAROLINSKA INSTITUTET
Call Details Advanced Grant (AdG), LS4, ERC-2009-AdG
Summary Understanding the molecular mechanisms underlying adipose blood vessel growth or regression opens new fundamentally insight into novel therapeutic options for the treatment of obesity and its related metabolic diseases such as type 2 diabetes and cancer. Unlike any other tissues in the body, the adipose tissue constantly experiences expansion and shrinkage throughout the adult life. Adipocytes in the white adipose tissue have the ability to switch into metabolically highly active brown-like adipocytes. Brown adipose tissue (BAT) contains significantly higher numbers of microvessels than white adipose tissue (WAT) in order to adopt the high rates of metabolism. Thus, an angiogenic phenotype has to be switched on during the transition from WAT into BAT. We have found that acclimation of mice in cold could induce transition from inguinal and epidedymal WAT into BAT by upregulation of angiogenic factor expression and down-regulations of angiogenesis inhibitors (Xue et al, Cell Metabolism, 2009). The transition from WAT into BAT is dependent on vascular endothelial growth factor (VEGF) that primarily targets on vascular endothelial cells via a tissue hypoxia-independent mechanism. VEGF blockade significantly alters adipose tissue metabolism. In another genetic model, we show similar findings that angiogenesis is crucial to mediate the transition from WAT into BAT (Xue et al, PNAS, 2008). Here we propose that the vascular tone determines the metabolic switch between WAT and BAT. Characterization of these novel angiogenic pathways may reveal new mechanisms underlying development of obesity- and metabolism-related disease complications and may define novel therapeutic targets. Thus, the benefit of this research proposal is enormous and is aimed to treat the most common and highly risk human health conditions in the modern time.
Summary
Understanding the molecular mechanisms underlying adipose blood vessel growth or regression opens new fundamentally insight into novel therapeutic options for the treatment of obesity and its related metabolic diseases such as type 2 diabetes and cancer. Unlike any other tissues in the body, the adipose tissue constantly experiences expansion and shrinkage throughout the adult life. Adipocytes in the white adipose tissue have the ability to switch into metabolically highly active brown-like adipocytes. Brown adipose tissue (BAT) contains significantly higher numbers of microvessels than white adipose tissue (WAT) in order to adopt the high rates of metabolism. Thus, an angiogenic phenotype has to be switched on during the transition from WAT into BAT. We have found that acclimation of mice in cold could induce transition from inguinal and epidedymal WAT into BAT by upregulation of angiogenic factor expression and down-regulations of angiogenesis inhibitors (Xue et al, Cell Metabolism, 2009). The transition from WAT into BAT is dependent on vascular endothelial growth factor (VEGF) that primarily targets on vascular endothelial cells via a tissue hypoxia-independent mechanism. VEGF blockade significantly alters adipose tissue metabolism. In another genetic model, we show similar findings that angiogenesis is crucial to mediate the transition from WAT into BAT (Xue et al, PNAS, 2008). Here we propose that the vascular tone determines the metabolic switch between WAT and BAT. Characterization of these novel angiogenic pathways may reveal new mechanisms underlying development of obesity- and metabolism-related disease complications and may define novel therapeutic targets. Thus, the benefit of this research proposal is enormous and is aimed to treat the most common and highly risk human health conditions in the modern time.
Max ERC Funding
2 411 547 €
Duration
Start date: 2010-03-01, End date: 2015-02-28
Project acronym AngioGenesHD
Project Epistasis analysis of angiogenes with high cellular definition
Researcher (PI) Rui Miguel Dos Santos Benedito
Host Institution (HI) CENTRO NACIONAL DE INVESTIGACIONESCARDIOVASCULARES CARLOS III (F.S.P.)
Call Details Starting Grant (StG), LS4, ERC-2014-STG
Summary Blood and lymphatic vessels have been the subject of intense investigation due to their important role in cancer development and in cardiovascular diseases. The significant advance in the methods used to modify and analyse gene function have allowed us to obtain a much better understanding of the molecular mechanisms involved in the regulation of the biology of blood vessels. However, there are two key aspects that significantly diminish our capacity to understand the function of gene networks and their intersections in vivo. One is the long time that is usually required to generate a given double mutant vertebrate tissue, and the other is the lack of single-cell genetic and phenotypic resolution. We have recently performed an in vivo comparative transcriptome analysis of highly angiogenic endothelial cells experiencing different VEGF and Notch signalling levels. These are two of the most important molecular mechanisms required for the adequate differentiation, proliferation and sprouting of endothelial cells. Using the information generated from this analysis, the overall aim of the proposed project is to characterize the vascular function of some of the previously identified genes and determine how they functionally interact with these two signalling pathways. We propose to use novel inducible genetic tools that will allow us to generate a spatially and temporally regulated fluorescent cell mosaic matrix for quantitative analysis. This will enable us to analyse with unprecedented speed and resolution the function of several different genes simultaneously, during vascular development, homeostasis or associated diseases. Understanding the genetic epistatic interactions that control the differentiation and behaviour of endothelial cells, in different contexts, and with high cellular definition, has the potential to unveil new mechanisms with high biological and therapeutic relevance.
Summary
Blood and lymphatic vessels have been the subject of intense investigation due to their important role in cancer development and in cardiovascular diseases. The significant advance in the methods used to modify and analyse gene function have allowed us to obtain a much better understanding of the molecular mechanisms involved in the regulation of the biology of blood vessels. However, there are two key aspects that significantly diminish our capacity to understand the function of gene networks and their intersections in vivo. One is the long time that is usually required to generate a given double mutant vertebrate tissue, and the other is the lack of single-cell genetic and phenotypic resolution. We have recently performed an in vivo comparative transcriptome analysis of highly angiogenic endothelial cells experiencing different VEGF and Notch signalling levels. These are two of the most important molecular mechanisms required for the adequate differentiation, proliferation and sprouting of endothelial cells. Using the information generated from this analysis, the overall aim of the proposed project is to characterize the vascular function of some of the previously identified genes and determine how they functionally interact with these two signalling pathways. We propose to use novel inducible genetic tools that will allow us to generate a spatially and temporally regulated fluorescent cell mosaic matrix for quantitative analysis. This will enable us to analyse with unprecedented speed and resolution the function of several different genes simultaneously, during vascular development, homeostasis or associated diseases. Understanding the genetic epistatic interactions that control the differentiation and behaviour of endothelial cells, in different contexts, and with high cellular definition, has the potential to unveil new mechanisms with high biological and therapeutic relevance.
Max ERC Funding
1 481 375 €
Duration
Start date: 2015-03-01, End date: 2020-02-29
Project acronym Angiolnc
Project Endothelial long non-coding RNAs
Researcher (PI) Stefanie Dimmeler
Host Institution (HI) JOHANN WOLFGANG GOETHE-UNIVERSITATFRANKFURT AM MAIN
Call Details Advanced Grant (AdG), LS4, ERC-2014-ADG
Summary Endothelial cells comprise the inner cellular cover of the vasculature, which delivers metabolites and oxygen to the tissue. Dysfunction of endothelial cells as it occurs during aging or metabolic syndromes can result in atherosclerosis, which can lead to myocardial infarction or stroke, whereas pathological angiogenesis contributes to tumor growth and diabetic retinopathy. Thus, endothelial cells play central roles in pathophysiological processes of many diseases including cardiovascular diseases and cancer. Many studies explored the regulation of endothelial cell functions by growth factors, but the impact of epigenetic mechanisms and particularly the role of novel non-coding RNAs is largely unknown. More than 70 % of the human genome encodes for non-coding RNAs (ncRNAs) and increasing evidence suggests that a significant portion of these ncRNAs are functionally active as RNA molecules. Angiolnc aims to explore the function of long ncRNAs (lncRNAs) and particular circular RNAs (circRNAs) in the endothelium. LncRNAs comprise a heterogenic class of RNAs with a length of > 200 nucleotides and circRNAs are generated by back splicing.
Angiolnc is based on the discovery of novel endothelial hypoxia-regulated lncRNAs and circRNAs by next generation sequencing. To begin to understand the potential functions of lncRNAs in the endothelium, we will study two lncRNAs, named Angiolnc1 und Angiolnc2, as prototypical examples of endothelial cell-enriched lncRNAs that are regulated by oxygen levels. We will further dissect the epigenetic mechanisms, by which these lncRNAs regulate endothelial cell function. In the second part of the application, we will determine the regulation and function of circRNAs, which may act as molecular sponges in the cytoplasm. Finally, we will study the function of identified lncRNAs and circRNAs in mouse models and measure their expression in human specimens in order to determine their role as therapeutic targets or diagnostic tools.
Summary
Endothelial cells comprise the inner cellular cover of the vasculature, which delivers metabolites and oxygen to the tissue. Dysfunction of endothelial cells as it occurs during aging or metabolic syndromes can result in atherosclerosis, which can lead to myocardial infarction or stroke, whereas pathological angiogenesis contributes to tumor growth and diabetic retinopathy. Thus, endothelial cells play central roles in pathophysiological processes of many diseases including cardiovascular diseases and cancer. Many studies explored the regulation of endothelial cell functions by growth factors, but the impact of epigenetic mechanisms and particularly the role of novel non-coding RNAs is largely unknown. More than 70 % of the human genome encodes for non-coding RNAs (ncRNAs) and increasing evidence suggests that a significant portion of these ncRNAs are functionally active as RNA molecules. Angiolnc aims to explore the function of long ncRNAs (lncRNAs) and particular circular RNAs (circRNAs) in the endothelium. LncRNAs comprise a heterogenic class of RNAs with a length of > 200 nucleotides and circRNAs are generated by back splicing.
Angiolnc is based on the discovery of novel endothelial hypoxia-regulated lncRNAs and circRNAs by next generation sequencing. To begin to understand the potential functions of lncRNAs in the endothelium, we will study two lncRNAs, named Angiolnc1 und Angiolnc2, as prototypical examples of endothelial cell-enriched lncRNAs that are regulated by oxygen levels. We will further dissect the epigenetic mechanisms, by which these lncRNAs regulate endothelial cell function. In the second part of the application, we will determine the regulation and function of circRNAs, which may act as molecular sponges in the cytoplasm. Finally, we will study the function of identified lncRNAs and circRNAs in mouse models and measure their expression in human specimens in order to determine their role as therapeutic targets or diagnostic tools.
Max ERC Funding
2 497 398 €
Duration
Start date: 2016-01-01, End date: 2020-12-31
Project acronym AngioMature
Project Mechanisms of vascular maturation and quiescence during development, homeostasis and aging
Researcher (PI) Hellmut AUGUSTIN
Host Institution (HI) RUPRECHT-KARLS-UNIVERSITAET HEIDELBERG
Call Details Advanced Grant (AdG), LS4, ERC-2017-ADG
Summary Angiogenesis research has focused on the sprouting of new capillaries. The mechanisms of vessel maturation are much less well understood. Yet, the maintenance of a mature, quiescent, and organotypically-differentiated layer of endothelial cells (ECs) lining the inside of all blood vessels is vital for human health. The goal of ANGIOMATURE is to identify, validate, and implement novel mechanisms of vascular maturation and organotypic EC differentiation that are active during development, maintenance of vascular stability in adults, and undergo changes in aging. We recently identified previously unrecognized gene expression signatures of vascular maturation in a genome-wide screen of ECs isolated from newborn and adult mice. Epigenetic mechanisms were identified that control the EC transcriptome through gain and loss of DNA methylation as well as EC differentiation and signaling specification. These findings pave the way for groundbreaking novel opportunities to study vascular maturation. By characterizing functionally diverse types of blood vessels, including continuous ECs in lung and brain and sinusoidal ECs in liver and bone marrow, the ANGIOMATURE project will (1) determine up to single cell resolution the transcriptional and epigenetic program(s) of vascular maturation and organotypic differentiation during adolescence, (2) analyze the functional consequences of such program(s) in differentiated ECs and their adaptation to challenge, and (3) study changes of maturation and differentiation program(s) and vascular responses during aging. We will towards this end employ an interdisciplinary matrix of approaches involving omics, systems biology, conditional gene targeting, organoid cell culture, and experimental pathology to create a high-resolution structural and functional organotypic angioarchitectural map. The project will thereby yield transformative mechanistic insights into vital biological processes that are most important for human health and healthy aging.
Summary
Angiogenesis research has focused on the sprouting of new capillaries. The mechanisms of vessel maturation are much less well understood. Yet, the maintenance of a mature, quiescent, and organotypically-differentiated layer of endothelial cells (ECs) lining the inside of all blood vessels is vital for human health. The goal of ANGIOMATURE is to identify, validate, and implement novel mechanisms of vascular maturation and organotypic EC differentiation that are active during development, maintenance of vascular stability in adults, and undergo changes in aging. We recently identified previously unrecognized gene expression signatures of vascular maturation in a genome-wide screen of ECs isolated from newborn and adult mice. Epigenetic mechanisms were identified that control the EC transcriptome through gain and loss of DNA methylation as well as EC differentiation and signaling specification. These findings pave the way for groundbreaking novel opportunities to study vascular maturation. By characterizing functionally diverse types of blood vessels, including continuous ECs in lung and brain and sinusoidal ECs in liver and bone marrow, the ANGIOMATURE project will (1) determine up to single cell resolution the transcriptional and epigenetic program(s) of vascular maturation and organotypic differentiation during adolescence, (2) analyze the functional consequences of such program(s) in differentiated ECs and their adaptation to challenge, and (3) study changes of maturation and differentiation program(s) and vascular responses during aging. We will towards this end employ an interdisciplinary matrix of approaches involving omics, systems biology, conditional gene targeting, organoid cell culture, and experimental pathology to create a high-resolution structural and functional organotypic angioarchitectural map. The project will thereby yield transformative mechanistic insights into vital biological processes that are most important for human health and healthy aging.
Max ERC Funding
2 338 918 €
Duration
Start date: 2018-08-01, End date: 2023-07-31
