Project acronym CARDIONECT
Project Cardiac Connective Tissue: Beat-by-Beat Relevance for Heart Function in Health and Disease
Researcher (PI) Peter Kohl
Host Institution (HI) UNIVERSITAETSKLINIKUM FREIBURG
Call Details Advanced Grant (AdG), LS4, ERC-2012-ADG_20120314
Summary Cardiac connective tissue is regarded as passive in terms of cardiac electro-mechanics. However, recent evidence confirms that fibroblasts interact directly with cardiac muscle cells in a way that is likely to affect their beat-by-beat activity.
To overcome limitations of traditional approaches to exploring these interactions in native tissue, we will build and explore murine models that express functional reporters (membrane potential, Vm; calcium concentration, [Ca2+]i) in fibroblasts, to identify how they are functionally integrated in native heart (myocyte => fibroblast effects). Next, we will express light-gated ion channels in murine fibroblast, to selectively interfere with their Vm (fibroblast => myocyte effects). Fibroblast-specific observation and interference will be conducted in normal and pathologically remodelled tissue, to characterise fibroblast relevance for heart function in health & disease.
Based on these studies, we will generate 2 transgenic rabbits (fibroblast Vm reporting / interfering). Rabbit cardiac structure-function is more amenable to translational work, e.g. to study fibroblast involvement in normal origin & spread of excitation across the heart, in pathological settings such as arrhythmogenicity of post-infarct scars (a leading causes of sudden death), or as a determinant of therapeutic outcomes such as in healing of atrial ablation lines (interfering with a key interventions to treat atrial fibrillation).
The final ‘blue-skies’ study will assess whether modulation of cardiac activity, from ‘tuning’ of biological pacemaker rates to ‘unpinning’ / termination of re-entrant excitation waves, can be achieved by targeting not myocytes, but fibroblasts.
The study integrates basic-science-driven discovery research into mechanisms and dynamics of biophysical myocyte-fibroblast interactions, generation of novel transgenic models useful for a broad range of studies, and elucidation of conceptually new approaches to heart rhythm management.
Summary
Cardiac connective tissue is regarded as passive in terms of cardiac electro-mechanics. However, recent evidence confirms that fibroblasts interact directly with cardiac muscle cells in a way that is likely to affect their beat-by-beat activity.
To overcome limitations of traditional approaches to exploring these interactions in native tissue, we will build and explore murine models that express functional reporters (membrane potential, Vm; calcium concentration, [Ca2+]i) in fibroblasts, to identify how they are functionally integrated in native heart (myocyte => fibroblast effects). Next, we will express light-gated ion channels in murine fibroblast, to selectively interfere with their Vm (fibroblast => myocyte effects). Fibroblast-specific observation and interference will be conducted in normal and pathologically remodelled tissue, to characterise fibroblast relevance for heart function in health & disease.
Based on these studies, we will generate 2 transgenic rabbits (fibroblast Vm reporting / interfering). Rabbit cardiac structure-function is more amenable to translational work, e.g. to study fibroblast involvement in normal origin & spread of excitation across the heart, in pathological settings such as arrhythmogenicity of post-infarct scars (a leading causes of sudden death), or as a determinant of therapeutic outcomes such as in healing of atrial ablation lines (interfering with a key interventions to treat atrial fibrillation).
The final ‘blue-skies’ study will assess whether modulation of cardiac activity, from ‘tuning’ of biological pacemaker rates to ‘unpinning’ / termination of re-entrant excitation waves, can be achieved by targeting not myocytes, but fibroblasts.
The study integrates basic-science-driven discovery research into mechanisms and dynamics of biophysical myocyte-fibroblast interactions, generation of novel transgenic models useful for a broad range of studies, and elucidation of conceptually new approaches to heart rhythm management.
Max ERC Funding
2 498 612 €
Duration
Start date: 2013-07-01, End date: 2019-06-30
Project acronym CARDIOREDOX
Project Redox sensing and signalling in cardiovascular health and disease
Researcher (PI) Philip Eaton
Host Institution (HI) KING'S COLLEGE LONDON
Call Details Advanced Grant (AdG), LS4, ERC-2013-ADG
Summary "We want to determine how oxidants are sensed and transduced into a biological effect within the cardiovascular system. The proposed work will focus on thiol-based redox sensors, defining their role in heart and blood vessel function during health and disease. Although this laboratory has studied the molecular basis of redox signaling for more than a decade, the subject is still in its relative infancy with considerable scope for major advances. Oxidant signaling remains a ‘hot topic’ with high profile studies confirming a fundamental role for redox control of protein and cellular function continuing to emerge. The molecular basis of redox sensing is the reaction of an oxidant with target proteins. This gives rise to oxidative post-translational modifications, most commonly of cysteinyl thiols, potentially altering the activity of proteins to regulate cell or tissue function. One of the reasons there are so many unanswered questions about redox sensing and signaling is the diversity of oxidant molecules produced by cells that can interact with sensor proteins to alter their function. This application is aimed at extending our knowledge of redox sensing and signalling, allowing us to define its importance in cardiovascular health and disease."
Summary
"We want to determine how oxidants are sensed and transduced into a biological effect within the cardiovascular system. The proposed work will focus on thiol-based redox sensors, defining their role in heart and blood vessel function during health and disease. Although this laboratory has studied the molecular basis of redox signaling for more than a decade, the subject is still in its relative infancy with considerable scope for major advances. Oxidant signaling remains a ‘hot topic’ with high profile studies confirming a fundamental role for redox control of protein and cellular function continuing to emerge. The molecular basis of redox sensing is the reaction of an oxidant with target proteins. This gives rise to oxidative post-translational modifications, most commonly of cysteinyl thiols, potentially altering the activity of proteins to regulate cell or tissue function. One of the reasons there are so many unanswered questions about redox sensing and signaling is the diversity of oxidant molecules produced by cells that can interact with sensor proteins to alter their function. This application is aimed at extending our knowledge of redox sensing and signalling, allowing us to define its importance in cardiovascular health and disease."
Max ERC Funding
2 255 659 €
Duration
Start date: 2013-12-01, End date: 2018-11-30
Project acronym CARDIOSPLICE
Project A systems and targeted approach to alternative splicing in the developing and diseased heart: Translating basic cell biology to improved cardiac function
Researcher (PI) Michael Gotthardt
Host Institution (HI) MAX DELBRUECK CENTRUM FUER MOLEKULARE MEDIZIN IN DER HELMHOLTZ-GEMEINSCHAFT (MDC)
Call Details Starting Grant (StG), LS4, ERC-2011-StG_20101109
Summary Cardiovascular disease keeps the top spot in mortality statistics in Europe with 2 million deaths annually and although prevention and therapy have continuously been improved, the prevalence of heart failure continues to rise. While contractile (systolic) dysfunction is readily accessible to pharmacological treatment, there is a lack of therapeutic options for reduced ventricular filling (diastolic dysfunction). The diastolic properties of the heart are largely determined by the giant sarcomeric protein titin, which is alternatively spliced to adjust the elastic properties of the cardiomyocyte. We have recently identified a titin splice factor that plays a parallel role in cardiac disease and postnatal development. It targets a subset of genes that concertedly affect biomechanics, electrical activity, and signal transduction and suggests alternative splicing as a novel therapeutic target in heart disease. Here we will build on the titin splice factor to identify regulatory principles and cofactors that adjust cardiac isoform expression. In a complementary approach we will investigate titin mRNA binding proteins to provide a comprehensive analysis of factors governing titin’s differential splicing in cardiac development, health, and disease. Based on its distinctive role in ventricular filling we will evaluate titin splicing as a therapeutic target in diastolic heart failure and use a titin based reporter assay to identify small molecules to interfere with titin isoform expression. Finally, we will evaluate the effects of altered alternative splicing on diastolic dysfunction in vivo utilizing the splice deficient mutant and our available animal models for diastolic dysfunction.
The overall scientific goal of the proposed work is to investigate the regulation of cardiac alternative splicing in development and disease and to evaluate if splice directed therapy can be used to improve diastolic function and specifically the elastic properties of the heart.
Summary
Cardiovascular disease keeps the top spot in mortality statistics in Europe with 2 million deaths annually and although prevention and therapy have continuously been improved, the prevalence of heart failure continues to rise. While contractile (systolic) dysfunction is readily accessible to pharmacological treatment, there is a lack of therapeutic options for reduced ventricular filling (diastolic dysfunction). The diastolic properties of the heart are largely determined by the giant sarcomeric protein titin, which is alternatively spliced to adjust the elastic properties of the cardiomyocyte. We have recently identified a titin splice factor that plays a parallel role in cardiac disease and postnatal development. It targets a subset of genes that concertedly affect biomechanics, electrical activity, and signal transduction and suggests alternative splicing as a novel therapeutic target in heart disease. Here we will build on the titin splice factor to identify regulatory principles and cofactors that adjust cardiac isoform expression. In a complementary approach we will investigate titin mRNA binding proteins to provide a comprehensive analysis of factors governing titin’s differential splicing in cardiac development, health, and disease. Based on its distinctive role in ventricular filling we will evaluate titin splicing as a therapeutic target in diastolic heart failure and use a titin based reporter assay to identify small molecules to interfere with titin isoform expression. Finally, we will evaluate the effects of altered alternative splicing on diastolic dysfunction in vivo utilizing the splice deficient mutant and our available animal models for diastolic dysfunction.
The overall scientific goal of the proposed work is to investigate the regulation of cardiac alternative splicing in development and disease and to evaluate if splice directed therapy can be used to improve diastolic function and specifically the elastic properties of the heart.
Max ERC Funding
1 499 191 €
Duration
Start date: 2012-01-01, End date: 2017-06-30
Project acronym CARDYADS
Project Controlling Cardiomyocyte Dyadic Structure
Researcher (PI) William Edward Louch
Host Institution (HI) UNIVERSITETET I OSLO
Call Details Consolidator Grant (CoG), LS4, ERC-2014-CoG
Summary Contraction and relaxation of cardiac myocytes, and thus the whole heart, are critically dependent on dyads. These functional junctions between t-tubules, which are invaginations of the surface membrane, and the sarcoplasmic reticulum allow efficient control of calcium release into the cytosol, and also its removal. Dyads are formed gradually during development and break down during disease. However, the precise nature of dyadic structure is unclear, even in healthy adult cardiac myocytes, as are the triggers and consequences of altering dyadic integrity. In this proposal, my group will investigate the precise 3-dimensional arrangement of dyads and their proteins during development, adulthood, and heart failure by employing CLEM imaging (PALM and EM tomography). This will be accomplished by developing transgenic mice with fluorescent labels on four dyadic proteins (L-type calcium channel, ryanodine receptor, sodium-calcium exchanger, SERCA), and by imaging tissue from explanted normal and failing human hearts. The signals responsible for controlling dyadic formation, maintenance, and disruption will be determined by performing high-throughput sequencing to identify novel genes involved with these processes in several established model systems. Particular focus will be given to investigating left ventricular wall stress and stretch-dependent gene regulation as controllers of dyadic integrity. Candidate genes will be manipulated in cell models and transgenic animals to promote dyadic formation and maintenance, and reverse dyadic disruption in heart failure. The consequences of dyadic structure for function will be tested experimentally and with mathematical modeling to examine effects on cardiac myocyte calcium homeostasis and whole-heart function. The results of this project are anticipated to yield unprecedented insight into dyadic structure, regulation, and function, and to identify novel therapeutic targets for heart disease patients.
Summary
Contraction and relaxation of cardiac myocytes, and thus the whole heart, are critically dependent on dyads. These functional junctions between t-tubules, which are invaginations of the surface membrane, and the sarcoplasmic reticulum allow efficient control of calcium release into the cytosol, and also its removal. Dyads are formed gradually during development and break down during disease. However, the precise nature of dyadic structure is unclear, even in healthy adult cardiac myocytes, as are the triggers and consequences of altering dyadic integrity. In this proposal, my group will investigate the precise 3-dimensional arrangement of dyads and their proteins during development, adulthood, and heart failure by employing CLEM imaging (PALM and EM tomography). This will be accomplished by developing transgenic mice with fluorescent labels on four dyadic proteins (L-type calcium channel, ryanodine receptor, sodium-calcium exchanger, SERCA), and by imaging tissue from explanted normal and failing human hearts. The signals responsible for controlling dyadic formation, maintenance, and disruption will be determined by performing high-throughput sequencing to identify novel genes involved with these processes in several established model systems. Particular focus will be given to investigating left ventricular wall stress and stretch-dependent gene regulation as controllers of dyadic integrity. Candidate genes will be manipulated in cell models and transgenic animals to promote dyadic formation and maintenance, and reverse dyadic disruption in heart failure. The consequences of dyadic structure for function will be tested experimentally and with mathematical modeling to examine effects on cardiac myocyte calcium homeostasis and whole-heart function. The results of this project are anticipated to yield unprecedented insight into dyadic structure, regulation, and function, and to identify novel therapeutic targets for heart disease patients.
Max ERC Funding
2 000 000 €
Duration
Start date: 2015-07-01, End date: 2020-06-30
Project acronym CAVEHEART
Project Heart regeneration in the Mexican cavefish: The difference between healing and scarring
Researcher (PI) Mathilda MOMMERSTEEG
Host Institution (HI) THE CHANCELLOR, MASTERS AND SCHOLARS OF THE UNIVERSITY OF OXFORD
Call Details Starting Grant (StG), LS4, ERC-2016-STG
Summary Whereas the human heart cannot regenerate cardiac muscle after myocardial infarction, certain fish efficiently repair their hearts. Astyanax mexicanus, a close relative of the zebrafish, is a single fish species comprising cave-dwelling and surface river populations. Remarkably, while surface fish regenerate their heart after injury, cavefish cannot and form a permanent fibrotic scar, similar to the human heart. Using transcriptomics analysis and immunohistochemistry, we have identified key differences in the scarring and inflammatory response between the surface and cavefish heart after injury. These differences include extracellular matrix (ECM) proteins, growth factors and macrophage populations present in one, but not the other population, suggesting properties unique to the surface fish scar that promote heart regeneration. The objective of the proposed project is to characterise and utilise these findings to identify therapeutic targets to heal the human heart after myocardial infarction. First, we will analyse the identified differences in scarring and immune response between the fish in detail, before testing the role of the most interesting proteins and macrophage populations during regeneration using CRISPR mutagenesis and clodronate liposomes. Next, we will link the key scarring and inflammatory differences directly to both the genome and the ability for heart regeneration using new and prior Quantitative Trait Loci analyses. This will allow to find the most fundamental molecular mechanisms directing the wound healing process towards regeneration versus scarring. Together with an in vitro and in vivo small molecule screen directed specifically at influencing scarring towards a more ‘fish-like’ regenerative phenotype in the cavefish and mouse heart after injury, this will provide targets for therapeutic strategies to maximise the endogenous regenerative potential of the mammalian heart, with the aim to find a cure for myocardial infarction.
Summary
Whereas the human heart cannot regenerate cardiac muscle after myocardial infarction, certain fish efficiently repair their hearts. Astyanax mexicanus, a close relative of the zebrafish, is a single fish species comprising cave-dwelling and surface river populations. Remarkably, while surface fish regenerate their heart after injury, cavefish cannot and form a permanent fibrotic scar, similar to the human heart. Using transcriptomics analysis and immunohistochemistry, we have identified key differences in the scarring and inflammatory response between the surface and cavefish heart after injury. These differences include extracellular matrix (ECM) proteins, growth factors and macrophage populations present in one, but not the other population, suggesting properties unique to the surface fish scar that promote heart regeneration. The objective of the proposed project is to characterise and utilise these findings to identify therapeutic targets to heal the human heart after myocardial infarction. First, we will analyse the identified differences in scarring and immune response between the fish in detail, before testing the role of the most interesting proteins and macrophage populations during regeneration using CRISPR mutagenesis and clodronate liposomes. Next, we will link the key scarring and inflammatory differences directly to both the genome and the ability for heart regeneration using new and prior Quantitative Trait Loci analyses. This will allow to find the most fundamental molecular mechanisms directing the wound healing process towards regeneration versus scarring. Together with an in vitro and in vivo small molecule screen directed specifically at influencing scarring towards a more ‘fish-like’ regenerative phenotype in the cavefish and mouse heart after injury, this will provide targets for therapeutic strategies to maximise the endogenous regenerative potential of the mammalian heart, with the aim to find a cure for myocardial infarction.
Max ERC Funding
1 499 429 €
Duration
Start date: 2017-03-01, End date: 2022-02-28
Project acronym CD40-INN
Project CD40 goes innate: defining and targeting CD40 signaling intermediates in the macrophage to treat atherosclerosis
Researcher (PI) Esther Lutgens Leiner
Host Institution (HI) ACADEMISCH MEDISCH CENTRUM BIJ DE UNIVERSITEIT VAN AMSTERDAM
Call Details Consolidator Grant (CoG), LS4, ERC-2015-CoG
Summary Atherosclerosis, the underlying cause of the majority of cardiovascular diseases (CVD), is a lipid driven, inflammatory disease of the large arteries. Despite a 25% relative risk reduction achieved by lipid-lowering treatment, the vast majority of atherosclerosis-induced CVD risk remains unaddressed. Therefore, characterizing mediators of the inflammatory aspect of atherosclerosis is a widely recognized scientific goal with great therapeutic implications.
Co-stimulatory molecules are key players in modulating immune interactions. My laboratory has defined the co-stimulatory CD40-CD40L dyad as a major driver of atherosclerosis. Inhibition of CD40, and of its interaction with the adaptor molecule TRAF6 by genetic deficiency, antibody treatment or (nanoparticle based) small molecule inhibitor (SMI) treatment, is one of the most powerful therapies to reduce atherosclerosis in a laboratory setting. Although CD40-CD40L interactions are associated with adaptive immunity, I recently identified the macrophage as a driver of CD40-induced inflammation in atherosclerosis. We will use state-of-the-art in vitro experiments, live cell-, super resolution imaging, proteomics approaches and mutant mouse models to unravel the role of macrophage CD40 in atherosclerosis. Moreover, using structure based virtual ligand screening, I will develop lead SMIs targeting macrophage CD40-signaling, which I will deliver using macrophage-targeting nanoparticles. My goal is to define the role of macrophage CD40 in inflammation and immunity and disentangle how its activation affects atherosclerosis. I will finally test the feasibility of targeting macrophage CD40-signaling as a treatment for CVD.
These studies will define the role of CD40-signaling in the innate immune system in health and (cardiovascular) disease. As components of macrophage CD40-signaling have the potential to be amenable to pharmacological manipulation, we will establish their feasibility as novel targets for (CVD) treatment.
Summary
Atherosclerosis, the underlying cause of the majority of cardiovascular diseases (CVD), is a lipid driven, inflammatory disease of the large arteries. Despite a 25% relative risk reduction achieved by lipid-lowering treatment, the vast majority of atherosclerosis-induced CVD risk remains unaddressed. Therefore, characterizing mediators of the inflammatory aspect of atherosclerosis is a widely recognized scientific goal with great therapeutic implications.
Co-stimulatory molecules are key players in modulating immune interactions. My laboratory has defined the co-stimulatory CD40-CD40L dyad as a major driver of atherosclerosis. Inhibition of CD40, and of its interaction with the adaptor molecule TRAF6 by genetic deficiency, antibody treatment or (nanoparticle based) small molecule inhibitor (SMI) treatment, is one of the most powerful therapies to reduce atherosclerosis in a laboratory setting. Although CD40-CD40L interactions are associated with adaptive immunity, I recently identified the macrophage as a driver of CD40-induced inflammation in atherosclerosis. We will use state-of-the-art in vitro experiments, live cell-, super resolution imaging, proteomics approaches and mutant mouse models to unravel the role of macrophage CD40 in atherosclerosis. Moreover, using structure based virtual ligand screening, I will develop lead SMIs targeting macrophage CD40-signaling, which I will deliver using macrophage-targeting nanoparticles. My goal is to define the role of macrophage CD40 in inflammation and immunity and disentangle how its activation affects atherosclerosis. I will finally test the feasibility of targeting macrophage CD40-signaling as a treatment for CVD.
These studies will define the role of CD40-signaling in the innate immune system in health and (cardiovascular) disease. As components of macrophage CD40-signaling have the potential to be amenable to pharmacological manipulation, we will establish their feasibility as novel targets for (CVD) treatment.
Max ERC Funding
1 999 420 €
Duration
Start date: 2016-12-01, End date: 2021-11-30
Project acronym CELLPLASTICITY
Project New Frontiers in Cellular Reprogramming: Exploiting Cellular Plasticity
Researcher (PI) Manuel SERRANO MARUGAN
Host Institution (HI) FUNDACIO INSTITUT DE RECERCA BIOMEDICA (IRB BARCELONA)
Call Details Advanced Grant (AdG), LS4, ERC-2014-ADG
Summary "Our research group has worked over the years at the interface between cancer and ageing, with a strong emphasis on mouse models. More recently, we became interested in cellular reprogramming because we hypothesized that understanding cellular plasticity could yield new insights into cancer and ageing. Indeed, during the previous ERC Advanced Grant, we made relevant contributions to the fields of cellular reprogramming (Nature 2013), cellular senescence (Cell 2013), cancer (Cancer Cell 2012), and ageing (Cell Metabolism 2012). Now, we take advantage of our diverse background and integrate the above processes. Our unifying hypothesis is that cellular plasticity lies at the basis of tissue regeneration (“adaptive cellular plasticity”), as well as at the origin of cancer (“maladaptive gain of cellular plasticity”) and ageing (“maladaptive loss of cellular plasticity”). A key experimental system will be our “reprogrammable mice” (with inducible expression of the four Yamanaka factors), which we regard as a tool to induce cellular plasticity in vivo. The project is divided as follows: Objective #1 – Cellular plasticity and cancer: role of tumour suppressors in in vivo de-differentiation and reprogramming / impact of transient de-differentiation on tumour initiation / lineage tracing of Oct4 to determine whether a transient pluripotent-state occurs during cancer. Objective #2 – Cellular plasticity in tissue regeneration and ageing: impact of transient de-differentiation on tissue regeneration / contribution of the damage-induced microenvironment to tissue regeneration / impact of transient de-differentiation on ageing. Objective #3: New frontiers in cellular plasticity: chemical manipulation of cellular plasticity in vivo / new states of pluripotency / characterization of in vivo induced pluripotency and its unique properties. We anticipate that the completion of this project will yield new fundamental insights into cancer, regeneration and ageing."
Summary
"Our research group has worked over the years at the interface between cancer and ageing, with a strong emphasis on mouse models. More recently, we became interested in cellular reprogramming because we hypothesized that understanding cellular plasticity could yield new insights into cancer and ageing. Indeed, during the previous ERC Advanced Grant, we made relevant contributions to the fields of cellular reprogramming (Nature 2013), cellular senescence (Cell 2013), cancer (Cancer Cell 2012), and ageing (Cell Metabolism 2012). Now, we take advantage of our diverse background and integrate the above processes. Our unifying hypothesis is that cellular plasticity lies at the basis of tissue regeneration (“adaptive cellular plasticity”), as well as at the origin of cancer (“maladaptive gain of cellular plasticity”) and ageing (“maladaptive loss of cellular plasticity”). A key experimental system will be our “reprogrammable mice” (with inducible expression of the four Yamanaka factors), which we regard as a tool to induce cellular plasticity in vivo. The project is divided as follows: Objective #1 – Cellular plasticity and cancer: role of tumour suppressors in in vivo de-differentiation and reprogramming / impact of transient de-differentiation on tumour initiation / lineage tracing of Oct4 to determine whether a transient pluripotent-state occurs during cancer. Objective #2 – Cellular plasticity in tissue regeneration and ageing: impact of transient de-differentiation on tissue regeneration / contribution of the damage-induced microenvironment to tissue regeneration / impact of transient de-differentiation on ageing. Objective #3: New frontiers in cellular plasticity: chemical manipulation of cellular plasticity in vivo / new states of pluripotency / characterization of in vivo induced pluripotency and its unique properties. We anticipate that the completion of this project will yield new fundamental insights into cancer, regeneration and ageing."
Max ERC Funding
2 488 850 €
Duration
Start date: 2015-10-01, End date: 2021-03-31
Project acronym CESYDE
Project Ceramide Synthases in Diabetic Beta Cell Demise
Researcher (PI) Bengt-Frederik BELGARDT
Host Institution (HI) DEUTSCHE DIABETES FORSCHUNGSGESELLSCHAFT EV
Call Details Starting Grant (StG), LS4, ERC-2017-STG
Summary Sphingolipids including ceramides are building blocks of cell membranes, but also act as regulated intracellular messenger molecules. Emerging data indicate that sphingolipids are dynamically regulated by nutrients, and in turn control systemic metabolism, for example, by modulating insulin secretion, proliferation and cell death of pancreatic beta cells. Dysfunction and death of beta cells are key events during the development of diabetes, from which more than 400 million patients suffer worldwide. While pharmacological inhibition of general ceramide biosynthesis is protective against diabetes in animal studies, side effects of total loss of ceramides prevent medical implementation. The de novo synthesis of ceramides is fully dependent on six ceramide synthase enzymes (CerS 1-6), which are expressed in a tissue specific manner, and generate ceramides with different chain lengths. Currently, the functional roles and regulatory modulators of each CerS are unknown in pancreatic beta cells. Importantly, the downstream mechanisms by which ceramides impair beta cell function and eventually cause diabetes are not defined. Here, I propose to combine genomics, proteomics and lipidomics to assess the function of ceramide synthases expressed in mouse and human beta cells. Furthermore, both the subcellular localisation and the post-translational modifications of CerS will be determined. The ceramide-interacting proteins mediating the deleterious effects of ceramides will be identified by lipid-protein crosslinking and functionally tested. Finally, in a translational approach, we will test the ability of recently generated novel specific CerS inhibitors with improved specificity to ameliorate beta cell stress, and improve insulin secretion in mouse and human beta cells. In sum, we will identify, characterize, validate and target ceramide synthases involved in beta cell biology and development of diabetes.
Summary
Sphingolipids including ceramides are building blocks of cell membranes, but also act as regulated intracellular messenger molecules. Emerging data indicate that sphingolipids are dynamically regulated by nutrients, and in turn control systemic metabolism, for example, by modulating insulin secretion, proliferation and cell death of pancreatic beta cells. Dysfunction and death of beta cells are key events during the development of diabetes, from which more than 400 million patients suffer worldwide. While pharmacological inhibition of general ceramide biosynthesis is protective against diabetes in animal studies, side effects of total loss of ceramides prevent medical implementation. The de novo synthesis of ceramides is fully dependent on six ceramide synthase enzymes (CerS 1-6), which are expressed in a tissue specific manner, and generate ceramides with different chain lengths. Currently, the functional roles and regulatory modulators of each CerS are unknown in pancreatic beta cells. Importantly, the downstream mechanisms by which ceramides impair beta cell function and eventually cause diabetes are not defined. Here, I propose to combine genomics, proteomics and lipidomics to assess the function of ceramide synthases expressed in mouse and human beta cells. Furthermore, both the subcellular localisation and the post-translational modifications of CerS will be determined. The ceramide-interacting proteins mediating the deleterious effects of ceramides will be identified by lipid-protein crosslinking and functionally tested. Finally, in a translational approach, we will test the ability of recently generated novel specific CerS inhibitors with improved specificity to ameliorate beta cell stress, and improve insulin secretion in mouse and human beta cells. In sum, we will identify, characterize, validate and target ceramide synthases involved in beta cell biology and development of diabetes.
Max ERC Funding
1 492 314 €
Duration
Start date: 2018-01-01, End date: 2022-12-31
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 CHD-IPS
Project Modeling congenital heart disease (CHD) in ISL1+ cardiovascular progenitors from patient-specific iPS cells
Researcher (PI) Karl-Ludwig Laugwitz
Host Institution (HI) KLINIKUM RECHTS DER ISAR DER TECHNISCHEN UNIVERSITAT MUNCHEN
Call Details Starting Grant (StG), LS4, ERC-2010-StG_20091118
Summary Tetralogy of Fallot (TOF) is the most common congenital heart disease (CHD) occurring 1 in 3000 births. Genetic studies have identified numerous genes that are responsible for inherited and sporadic forms of TOF, most of which encode key molecules that are part of regulatory networks controlling heart development. The identification of two populations of cardiac precursors, one exclusively forming the left ventricle and the second the outflow tract, the right ventricle and the atria, has suggested a new approach to interpret CHDs, in particular in TOF, not as a defect in a specific gene, but rather as a defect in the formation, expansion, and differentiation of defined subsets of embryonic cardiac precursors. The LIM-homeodomain transcription factor ISL1 marks the second population of cardiac progenitors, but little is known about its downstream targets, and how causative genes of CHDs affect cell-fate decisions in the ISL1 lineage. The main goals of this research program are: (1) to decipher the functional role of Isl1 downstream targets identified by a genome-wide ChIP-Seq approach; (2) to generate induced pluripotent stem (iPS) cells from controls and patients affected by severe forms of TOF characterized by defects in heart compartments known to derive from ISL1 cardiac progenitors; (3) to direct these iPS cells to ISL1+ cardiovascular precursors and identify cell-surface makers enabling their antibody-based purification; and (4) to use TOF-iPS-derived ISL1+ progenitors as an unique in vitro model system for deciphering molecular mechanisms that govern the fates and differentiation of this progenitor lineage and determine the pathological phenotype seen in TOF. This work will shed light on the molecular mechanisms of ISL1+ cardiac progenitor lineage specification and will give important new insights into the mechanisms of how alterations in transcriptional and epigenetic programs translate to a distinct structural defect during cardiogenesis.
Summary
Tetralogy of Fallot (TOF) is the most common congenital heart disease (CHD) occurring 1 in 3000 births. Genetic studies have identified numerous genes that are responsible for inherited and sporadic forms of TOF, most of which encode key molecules that are part of regulatory networks controlling heart development. The identification of two populations of cardiac precursors, one exclusively forming the left ventricle and the second the outflow tract, the right ventricle and the atria, has suggested a new approach to interpret CHDs, in particular in TOF, not as a defect in a specific gene, but rather as a defect in the formation, expansion, and differentiation of defined subsets of embryonic cardiac precursors. The LIM-homeodomain transcription factor ISL1 marks the second population of cardiac progenitors, but little is known about its downstream targets, and how causative genes of CHDs affect cell-fate decisions in the ISL1 lineage. The main goals of this research program are: (1) to decipher the functional role of Isl1 downstream targets identified by a genome-wide ChIP-Seq approach; (2) to generate induced pluripotent stem (iPS) cells from controls and patients affected by severe forms of TOF characterized by defects in heart compartments known to derive from ISL1 cardiac progenitors; (3) to direct these iPS cells to ISL1+ cardiovascular precursors and identify cell-surface makers enabling their antibody-based purification; and (4) to use TOF-iPS-derived ISL1+ progenitors as an unique in vitro model system for deciphering molecular mechanisms that govern the fates and differentiation of this progenitor lineage and determine the pathological phenotype seen in TOF. This work will shed light on the molecular mechanisms of ISL1+ cardiac progenitor lineage specification and will give important new insights into the mechanisms of how alterations in transcriptional and epigenetic programs translate to a distinct structural defect during cardiogenesis.
Max ERC Funding
1 499 996 €
Duration
Start date: 2011-03-01, End date: 2017-02-28
