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 BetaRegeneration
Project Induction of Insulin-producing beta-cells Regeneration in vivo
Researcher (PI) Patrick Collombat
Host Institution (HI) INSTITUT NATIONAL DE LA SANTE ET DE LA RECHERCHE MEDICALE
Call Details Starting Grant (StG), LS4, ERC-2011-StG_20101109
Summary Diabetes has become one of the most widespread metabolic disorders with epidemic dimensions affecting almost 6% of the world’s population. Despite modern treatments, the life expectancy of patients with Type 1 diabetes remains reduced as compared to healthy subjects. There is therefore a need for alternative therapies. Towards this aim, using the mouse, we recently demonstrated that the in vivo forced expression of a single factor in pancreatic alpha-cells is sufficient to induce a continuous regeneration of alpha-cells and their subsequent conversion into beta-like cells, such converted cells being capable of reversing the consequences of chemically-induced diabetes in vivo (Collombat et al. Cell, 2009).
The PI and his team therefore propose to further decipher the mechanisms involved in this alpha-cell-mediated beta-cell regeneration process and determine whether this approach may be applied to adult animals and whether it would efficiently reverse Type 1 diabetes. Furthermore, a major effort will be made to verify whether our findings could be translated to human. Specifically, we will use a tri-partite approach to address the following issues: (1) Can the in vivo alpha-cell-mediated beta-cell regeneration be induced in adults mice? What would be the genetic determinants involved? (2) Can alpha-cell-mediated beta-cell regeneration reverse diabetes in the NOD Type 1 diabetes mouse model? (3) Can adult human alpha-cells be converted into beta-like cells?
Together, these ambitious objectives will most certainly allow us to gain new insight into the mechanisms defining the identity and the reprogramming capabilities of mouse and human endocrine cells and may thereby open new avenues for the treatment of diabetes. Similarly, the determination of the molecular triggers implicated in the beta-cell regeneration observed in our diabetic mice may lead to exciting new findings, including the identification of “drugable” targets of importance for human diabetic patients.
Summary
Diabetes has become one of the most widespread metabolic disorders with epidemic dimensions affecting almost 6% of the world’s population. Despite modern treatments, the life expectancy of patients with Type 1 diabetes remains reduced as compared to healthy subjects. There is therefore a need for alternative therapies. Towards this aim, using the mouse, we recently demonstrated that the in vivo forced expression of a single factor in pancreatic alpha-cells is sufficient to induce a continuous regeneration of alpha-cells and their subsequent conversion into beta-like cells, such converted cells being capable of reversing the consequences of chemically-induced diabetes in vivo (Collombat et al. Cell, 2009).
The PI and his team therefore propose to further decipher the mechanisms involved in this alpha-cell-mediated beta-cell regeneration process and determine whether this approach may be applied to adult animals and whether it would efficiently reverse Type 1 diabetes. Furthermore, a major effort will be made to verify whether our findings could be translated to human. Specifically, we will use a tri-partite approach to address the following issues: (1) Can the in vivo alpha-cell-mediated beta-cell regeneration be induced in adults mice? What would be the genetic determinants involved? (2) Can alpha-cell-mediated beta-cell regeneration reverse diabetes in the NOD Type 1 diabetes mouse model? (3) Can adult human alpha-cells be converted into beta-like cells?
Together, these ambitious objectives will most certainly allow us to gain new insight into the mechanisms defining the identity and the reprogramming capabilities of mouse and human endocrine cells and may thereby open new avenues for the treatment of diabetes. Similarly, the determination of the molecular triggers implicated in the beta-cell regeneration observed in our diabetic mice may lead to exciting new findings, including the identification of “drugable” targets of importance for human diabetic patients.
Max ERC Funding
1 500 000 €
Duration
Start date: 2012-01-01, End date: 2016-12-31
Project acronym BreakingBarriers
Project Targeting endothelial barriers to combat disease
Researcher (PI) Anne Eichmann
Host Institution (HI) INSTITUT NATIONAL DE LA SANTE ET DE LA RECHERCHE MEDICALE
Call Details Advanced Grant (AdG), LS4, ERC-2018-ADG
Summary Tissue homeostasis requires coordinated barrier function in blood and lymphatic vessels. Opening of junctions between endothelial cells (ECs) lining blood vessels leads to tissue fluid accumulation that is drained by lymphatic vessels. A pathological increase in blood vessel permeability or lack or malfunction of lymphatic vessels leads to edema and associated defects in macromolecule and immune cell clearance. Unbalanced barrier function between blood and lymphatic vessels contributes to neurodegeneration, chronic inflammation, and cardiovascular disease. In this proposal, we seek to gain mechanistic understanding into coordination of barrier function between blood and lymphatic vessels, how this process is altered in disease models and how it can be manipulated for therapeutic purposes. We will focus on two critical barriers with diametrically opposing functions, the blood-brain barrier (BBB) and the lymphatic capillary barrier (LCB). ECs of the BBB form very tight junctions that restrict paracellular access to the brain. In contrast, open junctions of the LCB ensure uptake of extravasated fluid, macromolecules and immune cells, as well as lipid in the gut. We have identified novel effectors of BBB and LCB junctions and will determine their role in adult homeostasis and in disease models. Mouse genetic gain and loss of function approaches in combination with histological, ultrastructural, functional and molecular analysis will determine mechanisms underlying formation of tissue specific EC barriers. Deliverables include in vivo validated targets that could be used for i) opening the BBB on demand for drug delivery into the brain, and ii) to lower plasma lipid uptake via interfering with the LCB, with implications for prevention of obesity, cardiovascular disease and inflammation. These pioneering studies promise to open up new opportunities for research and treatment of neurovascular and cardiovascular disease.
Summary
Tissue homeostasis requires coordinated barrier function in blood and lymphatic vessels. Opening of junctions between endothelial cells (ECs) lining blood vessels leads to tissue fluid accumulation that is drained by lymphatic vessels. A pathological increase in blood vessel permeability or lack or malfunction of lymphatic vessels leads to edema and associated defects in macromolecule and immune cell clearance. Unbalanced barrier function between blood and lymphatic vessels contributes to neurodegeneration, chronic inflammation, and cardiovascular disease. In this proposal, we seek to gain mechanistic understanding into coordination of barrier function between blood and lymphatic vessels, how this process is altered in disease models and how it can be manipulated for therapeutic purposes. We will focus on two critical barriers with diametrically opposing functions, the blood-brain barrier (BBB) and the lymphatic capillary barrier (LCB). ECs of the BBB form very tight junctions that restrict paracellular access to the brain. In contrast, open junctions of the LCB ensure uptake of extravasated fluid, macromolecules and immune cells, as well as lipid in the gut. We have identified novel effectors of BBB and LCB junctions and will determine their role in adult homeostasis and in disease models. Mouse genetic gain and loss of function approaches in combination with histological, ultrastructural, functional and molecular analysis will determine mechanisms underlying formation of tissue specific EC barriers. Deliverables include in vivo validated targets that could be used for i) opening the BBB on demand for drug delivery into the brain, and ii) to lower plasma lipid uptake via interfering with the LCB, with implications for prevention of obesity, cardiovascular disease and inflammation. These pioneering studies promise to open up new opportunities for research and treatment of neurovascular and cardiovascular disease.
Max ERC Funding
2 499 969 €
Duration
Start date: 2019-07-01, End date: 2024-06-30
Project acronym CORTEXSELFCONTROL
Project Self-Modulating Neurons in the Cerebral Cortex: From Molecular Mechanisms to Cortical Network Activities
Researcher (PI) Alberto Bacci
Host Institution (HI) INSTITUT DU CERVEAU ET DE LA MOELLE EPINIERE
Call Details Starting Grant (StG), LS4, ERC-2007-StG
Summary In the mammalian brain, the neocortex is the site where sensory information is integrated into complex cognitive functions. This is accomplished by the activity of both principal glutamatergic neurons and locally-projecting inhibitory GABAergic interneurons, interconnected in complex networks. Inhibitory neurons play several key roles in neocortical function. For example, they shape sensory receptive fields and drive several high frequency network oscillations. On the other hand, defects in their function can lead to devastating diseases, such as epilepsy and schizophrenia. Cortical interneurons represent a highly heterogeneous cell population. Understanding the specific role of each interneuron subtype within cortical microcircuits is still a crucial open question. We have examined properties of two major functional interneuron subclasses in neocortical layer V: fast-spiking (FS) and low-threshold spiking (LTS) cells. Our previous data indicate that each group expresses a novel form of self inhibition, namely autaptic inhibitory transmission in FS cells and an endocannabinoid-mediated slow self inhibition in LTS interneurons. In this proposal we will address three major questions relevant to self-inhibition of neocortical interneurons: 1) What is the role of FS cell autapses in coordinating fast network synchrony? 2) What are the molecular mechanisms underlying autaptic asynchronous release, prolonging FS cell self-inhibition by several seconds, and what is its relevance during physiological and pathological network activities? 3) What are the induction mechanisms, the molecular players involved and the functional roles within cortical microcircuits of the endocannabinoid-mediated long-lasting self-inhibition in LTS interneurons? Results of these experiments will lead to a better understanding of GABAergic interneuron regulation of neocortical excitability, relevant to both normal and pathological cortical function.
Summary
In the mammalian brain, the neocortex is the site where sensory information is integrated into complex cognitive functions. This is accomplished by the activity of both principal glutamatergic neurons and locally-projecting inhibitory GABAergic interneurons, interconnected in complex networks. Inhibitory neurons play several key roles in neocortical function. For example, they shape sensory receptive fields and drive several high frequency network oscillations. On the other hand, defects in their function can lead to devastating diseases, such as epilepsy and schizophrenia. Cortical interneurons represent a highly heterogeneous cell population. Understanding the specific role of each interneuron subtype within cortical microcircuits is still a crucial open question. We have examined properties of two major functional interneuron subclasses in neocortical layer V: fast-spiking (FS) and low-threshold spiking (LTS) cells. Our previous data indicate that each group expresses a novel form of self inhibition, namely autaptic inhibitory transmission in FS cells and an endocannabinoid-mediated slow self inhibition in LTS interneurons. In this proposal we will address three major questions relevant to self-inhibition of neocortical interneurons: 1) What is the role of FS cell autapses in coordinating fast network synchrony? 2) What are the molecular mechanisms underlying autaptic asynchronous release, prolonging FS cell self-inhibition by several seconds, and what is its relevance during physiological and pathological network activities? 3) What are the induction mechanisms, the molecular players involved and the functional roles within cortical microcircuits of the endocannabinoid-mediated long-lasting self-inhibition in LTS interneurons? Results of these experiments will lead to a better understanding of GABAergic interneuron regulation of neocortical excitability, relevant to both normal and pathological cortical function.
Max ERC Funding
996 000 €
Duration
Start date: 2008-10-01, End date: 2014-03-31
Project acronym Damocles
Project Modelling brain aneurysm to elucidate the role of platelets
Researcher (PI) Yacine BOULAFTALI
Host Institution (HI) INSTITUT NATIONAL DE LA SANTE ET DE LA RECHERCHE MEDICALE
Call Details Starting Grant (StG), LS4, ERC-2017-STG
Summary In the European Union, 15 million people have an unruptured intracranial aneurysm (IA) that may rupture one day and lead to subarachnoid haemorrhage (SAH). The IA rupture event is ominous and lingers as a clinical quandary. No safe and effective non-invasive therapies have, as of yet, been identified and implemented in clinical practice mainly because of a lack of knowledge of the underlying mechanisms. Increasing evidence points to inflammation as one of the leading factors in the pathogenesis of IA. Intrasaccular clot formation is a common feature of IA occurring unruptured and ruptured IA. In addition to forming clots, activated platelets support leukocyte recruitment. Interestingly, platelets also prevent local hemorrhage in inflammatory situations independently of their ability to form a platelet plug.
We hypothesize that the role of platelet may evolve throughout the development of IA: initially playing a protective role of in the maintenance of vascular integrity in response to inflammation and contributing later to intrasaccular thrombus formation. What are the platelet signaling pathways and responses involved and to what extent do they contribute to the disease and the rupture event?
To answer these questions, we designed an interdisciplinary proposal, which gathers biophysical, pharmacological, and in-vivo approaches, with the following objectives: I) To investigate platelet functions from patients diagnosed with intracranial aneurysm at the sites of aneurysm sac. II) To delineate platelet mechanisms and responses in a cutting-edge technology of a 3D reconstruction of IA that will take into account the hemodynamic shear stress. III) To test in a preclinical mouse model of IA efficient anti-platelet therapies and define a therapeutic window to intervene on platelet activation. The proposed project will yield new insights in IA disease and in life science, from cell biology to the discovery of potential new targets in cardiovascular medicine.
Summary
In the European Union, 15 million people have an unruptured intracranial aneurysm (IA) that may rupture one day and lead to subarachnoid haemorrhage (SAH). The IA rupture event is ominous and lingers as a clinical quandary. No safe and effective non-invasive therapies have, as of yet, been identified and implemented in clinical practice mainly because of a lack of knowledge of the underlying mechanisms. Increasing evidence points to inflammation as one of the leading factors in the pathogenesis of IA. Intrasaccular clot formation is a common feature of IA occurring unruptured and ruptured IA. In addition to forming clots, activated platelets support leukocyte recruitment. Interestingly, platelets also prevent local hemorrhage in inflammatory situations independently of their ability to form a platelet plug.
We hypothesize that the role of platelet may evolve throughout the development of IA: initially playing a protective role of in the maintenance of vascular integrity in response to inflammation and contributing later to intrasaccular thrombus formation. What are the platelet signaling pathways and responses involved and to what extent do they contribute to the disease and the rupture event?
To answer these questions, we designed an interdisciplinary proposal, which gathers biophysical, pharmacological, and in-vivo approaches, with the following objectives: I) To investigate platelet functions from patients diagnosed with intracranial aneurysm at the sites of aneurysm sac. II) To delineate platelet mechanisms and responses in a cutting-edge technology of a 3D reconstruction of IA that will take into account the hemodynamic shear stress. III) To test in a preclinical mouse model of IA efficient anti-platelet therapies and define a therapeutic window to intervene on platelet activation. The proposed project will yield new insights in IA disease and in life science, from cell biology to the discovery of potential new targets in cardiovascular medicine.
Max ERC Funding
1 498 618 €
Duration
Start date: 2018-06-01, End date: 2023-05-31
Project acronym DEPREC
Project The Dependence Receptors notion: from a cell biology paradigm to anti-cancer targeted therapy
Researcher (PI) Patrick Mehlen
Host Institution (HI) UNIVERSITE LYON 1 CLAUDE BERNARD
Call Details Advanced Grant (AdG), LS4, ERC-2011-ADG_20110310
Summary "While it is assumed that transmembrane receptors are active only in the presence of ligand, we have proposed that some receptors may also be active in the absence of ligand stimulation. These receptors, named “dependence receptors” (DRs) share the ability to transmit two opposite signals: in the presence of ligand, these receptors transduce various classical “positive” signals, whereas in the absence of ligand, they trigger apoptosis. The expression of dependence receptors thus creates cellular states of dependence for survival on their respective ligands. To date, more than fifteen such receptors have been identified, including the netrin-1 receptors DCC (Deleted in Colorectal Cancer) and UNC5H1-4, some integrins, RET, EPHA4, TrkA, TrkC and the Sonic Hedgehog receptor Patched (Ptc). Even though the interest in this notion is increasing, two main questions remain poorly understood: (i) how very different receptors, with only modest homology, are able to trigger apoptosis when unengaged by their respective ligand, and (ii) what are the respective biological roles of this pro-apoptotic activity in vivo. We have hypothesized that the DRs pro-apoptotic activity is a mechanism that determines and regulates the territories of migration/localization of cells during embryonic development. We also demonstrated that this may be a mechanism that limits tumor growth and metastasis. The goal of the present project is, based on the study of a relatively small number of these receptors –i.e., DCC, UNC5H, RET, TrkC, Ptc- with a specifically larger emphasis on netrin-1 receptors, to address (i) the common and divergent cell signaling mechanisms triggering apoptosis downstream of these receptors and (ii) the physiological and pathological roles of these DRs on development of neoplasia in vivo. This latter goal will allow us to investigate how this pro-apoptotic activity can be of use to improve and diversify alternative anti-cancer therapeutic approaches."
Summary
"While it is assumed that transmembrane receptors are active only in the presence of ligand, we have proposed that some receptors may also be active in the absence of ligand stimulation. These receptors, named “dependence receptors” (DRs) share the ability to transmit two opposite signals: in the presence of ligand, these receptors transduce various classical “positive” signals, whereas in the absence of ligand, they trigger apoptosis. The expression of dependence receptors thus creates cellular states of dependence for survival on their respective ligands. To date, more than fifteen such receptors have been identified, including the netrin-1 receptors DCC (Deleted in Colorectal Cancer) and UNC5H1-4, some integrins, RET, EPHA4, TrkA, TrkC and the Sonic Hedgehog receptor Patched (Ptc). Even though the interest in this notion is increasing, two main questions remain poorly understood: (i) how very different receptors, with only modest homology, are able to trigger apoptosis when unengaged by their respective ligand, and (ii) what are the respective biological roles of this pro-apoptotic activity in vivo. We have hypothesized that the DRs pro-apoptotic activity is a mechanism that determines and regulates the territories of migration/localization of cells during embryonic development. We also demonstrated that this may be a mechanism that limits tumor growth and metastasis. The goal of the present project is, based on the study of a relatively small number of these receptors –i.e., DCC, UNC5H, RET, TrkC, Ptc- with a specifically larger emphasis on netrin-1 receptors, to address (i) the common and divergent cell signaling mechanisms triggering apoptosis downstream of these receptors and (ii) the physiological and pathological roles of these DRs on development of neoplasia in vivo. This latter goal will allow us to investigate how this pro-apoptotic activity can be of use to improve and diversify alternative anti-cancer therapeutic approaches."
Max ERC Funding
2 485 037 €
Duration
Start date: 2012-05-01, End date: 2017-04-30
Project acronym EpiFAT
Project Epigenomic Reprogramming of Adipose Tissue Function and Energy Metabolism in Type 2 Diabetes
Researcher (PI) Nicolas Adrien Michaël VENTECLEF
Host Institution (HI) INSTITUT NATIONAL DE LA SANTE ET DE LA RECHERCHE MEDICALE
Call Details Consolidator Grant (CoG), LS4, ERC-2016-COG
Summary Obesity is associated with adipose tissue dysfunction leading to the onset of several pathologies including type 2 diabetes (T2D). The mechanisms underlying the development of obesity and T2D include the hypertrophy and/or hyperplasia of adipocytes and adipose tissue inflammation together with an altered secretion of adipokines. However, the explanation of why individual obese (and some non-obese) humans differ in their susceptibility to develop T2D is still an issue that is currently not sufficiently addressed. This susceptibility to T2D is mainly associated with environmental factors. One link between environment and disease is epigenetics influencing gene expression and subsequently organ dysfunction. Epigenetic modifications in adipose tissue have been proposed to influence the susceptibility to T2D. However, the epigenomic mechanisms underpinning adipose tissue dysfunction are poorly known. In search for epigenomic modifiers that control adipose tissue function and also impact on T2D pathogenesis, we have recently identified the transcriptional coregulators GPS2 (G-Protein Pathway Suppressor 2) and KDM6B (Histone Lysine Demethylase 6B, also called JMJD3) as strong candidates.
Our hypothesis is that the clinically documented dysregulation of GPS2 (down) and KDM6B (up) expression and function during obesity leads to the closely linked epigenetic and transcriptional reprogramming of adipocytes and adipose tissue-macrophages, thereby enhancing the susceptibility to metabolic and inflammatory disturbances and the progression towards T2D.
We propose here to test this hypothesis using the combination of unique mouse models, genome-wide molecular and epigenomic analyses and human studies to dissect the epigenomic functions of GPS2 and KDM6B in adipose tissue, aiming at identifying mechanism involved in the development T2D. Thereby, we anticipate the discovery of novel epigenomic targets for future prevention and treatment strategies in metabolic dysfunction.
Summary
Obesity is associated with adipose tissue dysfunction leading to the onset of several pathologies including type 2 diabetes (T2D). The mechanisms underlying the development of obesity and T2D include the hypertrophy and/or hyperplasia of adipocytes and adipose tissue inflammation together with an altered secretion of adipokines. However, the explanation of why individual obese (and some non-obese) humans differ in their susceptibility to develop T2D is still an issue that is currently not sufficiently addressed. This susceptibility to T2D is mainly associated with environmental factors. One link between environment and disease is epigenetics influencing gene expression and subsequently organ dysfunction. Epigenetic modifications in adipose tissue have been proposed to influence the susceptibility to T2D. However, the epigenomic mechanisms underpinning adipose tissue dysfunction are poorly known. In search for epigenomic modifiers that control adipose tissue function and also impact on T2D pathogenesis, we have recently identified the transcriptional coregulators GPS2 (G-Protein Pathway Suppressor 2) and KDM6B (Histone Lysine Demethylase 6B, also called JMJD3) as strong candidates.
Our hypothesis is that the clinically documented dysregulation of GPS2 (down) and KDM6B (up) expression and function during obesity leads to the closely linked epigenetic and transcriptional reprogramming of adipocytes and adipose tissue-macrophages, thereby enhancing the susceptibility to metabolic and inflammatory disturbances and the progression towards T2D.
We propose here to test this hypothesis using the combination of unique mouse models, genome-wide molecular and epigenomic analyses and human studies to dissect the epigenomic functions of GPS2 and KDM6B in adipose tissue, aiming at identifying mechanism involved in the development T2D. Thereby, we anticipate the discovery of novel epigenomic targets for future prevention and treatment strategies in metabolic dysfunction.
Max ERC Funding
2 000 000 €
Duration
Start date: 2017-06-01, End date: 2022-05-31
Project acronym FAtoUnFRAGILITY
Project Fanconi anemia : a disease model to understand causes and consequences of common fragile site instability.
Researcher (PI) Valeria Naim
Host Institution (HI) CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS
Call Details Starting Grant (StG), LS4, ERC-2014-STG
Summary Originally described by cytogeneticists, common fragile sites (CFSs) are chromosomal regions known for their susceptibility to break and rearrange aberrantly, thus altering the expression of genes located therein. CFS instability is associated with tumor development and pathogenic copy number variations. Recent advances have significantly contributed to dissect the molecular bases of CFS instability, yet a unifying model for their unique breakage propensity has not been determined. Fanconi anemia (FA) is a chromosomal instability syndrome featuring congenital abnormalities, bone marrow failure and cancer predisposition, characterized by an increased CFS fragility. FA is thus an ideal model to understand the mechanisms underpinning CFS instability and the mechanistic link between CFS instability and the pathogenesis of disease phenotypes. I propose to use FA cellular models to examine the molecular events leading to CFS instability, and FA mouse models to investigate the consequences of deletions, amplifications or rearrangements involving CFSs on the expression of genes regulating critical signal transduction pathways involved in cell survival, proliferation, and differentiation. Exploring these mechanisms can lead to the development of chemopreventive or therapeutic strategies targeting aberrant gene expression or pathological pathways.
Summary
Originally described by cytogeneticists, common fragile sites (CFSs) are chromosomal regions known for their susceptibility to break and rearrange aberrantly, thus altering the expression of genes located therein. CFS instability is associated with tumor development and pathogenic copy number variations. Recent advances have significantly contributed to dissect the molecular bases of CFS instability, yet a unifying model for their unique breakage propensity has not been determined. Fanconi anemia (FA) is a chromosomal instability syndrome featuring congenital abnormalities, bone marrow failure and cancer predisposition, characterized by an increased CFS fragility. FA is thus an ideal model to understand the mechanisms underpinning CFS instability and the mechanistic link between CFS instability and the pathogenesis of disease phenotypes. I propose to use FA cellular models to examine the molecular events leading to CFS instability, and FA mouse models to investigate the consequences of deletions, amplifications or rearrangements involving CFSs on the expression of genes regulating critical signal transduction pathways involved in cell survival, proliferation, and differentiation. Exploring these mechanisms can lead to the development of chemopreventive or therapeutic strategies targeting aberrant gene expression or pathological pathways.
Max ERC Funding
1 462 383 €
Duration
Start date: 2015-06-01, End date: 2020-05-31
Project acronym HIFHEPC
Project HIF and hepcidin : missing links between infection, iron metabolism and cancer ?
Researcher (PI) Carole Sophie Isabelle Peyssonnaux
Host Institution (HI) INSTITUT NATIONAL DE LA SANTE ET DE LA RECHERCHE MEDICALE
Call Details Starting Grant (StG), LS4, ERC-2010-StG_20091118
Summary HIF transcription factors, central mediators of cellular adaptation to critically low oxygen levels (=hypoxia), have been largely studied for their crucial role during cancer development. Our recent findings have unveiled two new major roles of HIF. First, in innate immunity and infection, we demonstrated the key contributions of HIFs in regulating important immune effectors molecules. Second, we highlighted the role of HIFs in iron metabolism as critical regulators of iron absorption in the intestine and in systemic iron homeostasis by regulating the liver synthesis of the iron regulatory hormone, hepcidin.
These results open new research areas and our research program, based on unique mouse models of conditional HIFs and hepcidin knockout, will be developed around three main axes.
1) define the physiological roles of HIF and hepcidin in different key organs involved in maintaining body iron homeostasis. A detailed understanding of the regulation of iron-related proteins is a prerequisite in the development of therapeutics for iron diseases, which pose a major problem worldwide.
2) study the role of hepcidin during bacterial infection and tumorigenesis, two pathological conditions where iron is critically required for the proliferation of the pathogens and for cancer cells to feed their high metabolic activity.
3) determine the contribution of HIFs in the initiation of tumor development in response to infection. Indeed, our findings that HIF is stabilized by bacteria, even under normal levels of oxygen, and is an essential component of the inflammation response, let us to speculate that HIFs may be a missing link between infection and cancer by triggering a high chronic inflammatory response. For that, we will use the model of the gastric cancer, whose the initiating event is an infection by Helicobacter Pylori.
Summary
HIF transcription factors, central mediators of cellular adaptation to critically low oxygen levels (=hypoxia), have been largely studied for their crucial role during cancer development. Our recent findings have unveiled two new major roles of HIF. First, in innate immunity and infection, we demonstrated the key contributions of HIFs in regulating important immune effectors molecules. Second, we highlighted the role of HIFs in iron metabolism as critical regulators of iron absorption in the intestine and in systemic iron homeostasis by regulating the liver synthesis of the iron regulatory hormone, hepcidin.
These results open new research areas and our research program, based on unique mouse models of conditional HIFs and hepcidin knockout, will be developed around three main axes.
1) define the physiological roles of HIF and hepcidin in different key organs involved in maintaining body iron homeostasis. A detailed understanding of the regulation of iron-related proteins is a prerequisite in the development of therapeutics for iron diseases, which pose a major problem worldwide.
2) study the role of hepcidin during bacterial infection and tumorigenesis, two pathological conditions where iron is critically required for the proliferation of the pathogens and for cancer cells to feed their high metabolic activity.
3) determine the contribution of HIFs in the initiation of tumor development in response to infection. Indeed, our findings that HIF is stabilized by bacteria, even under normal levels of oxygen, and is an essential component of the inflammation response, let us to speculate that HIFs may be a missing link between infection and cancer by triggering a high chronic inflammatory response. For that, we will use the model of the gastric cancer, whose the initiating event is an infection by Helicobacter Pylori.
Max ERC Funding
1 500 000 €
Duration
Start date: 2011-06-01, End date: 2016-05-31
Project acronym IMMCEPTION
Project Nociception and sensory nerves as regulators of type 2 immunity and skin inflammation
Researcher (PI) Nicolas GAUDENZIO
Host Institution (HI) INSTITUT NATIONAL DE LA SANTE ET DE LA RECHERCHE MEDICALE
Call Details Starting Grant (StG), LS4, ERC-2018-STG
Summary Preserving skin homeostasis depends on complex interactions among structural cells, immune cells, and the environment. Dysregulation of this delicate equilibrium contributes to the development of type 2 immunity-associated skin inflammation (i.e., allergic skin inflammation), including atopic dermatitis (AD). The skin is a complex organ harboring various tissue-resident immune cells (e.g., dendritic cells, mast cells and macrophages) and innervated by a meshwork of sensory nerves, including those involved in nociception (i.e., nociceptors), which respond to injurious or potentially damaging stimuli by transmitting signals to the spinal cord and brain. Despite their role in the transmission of sensation, recent evidences have suggested that nociceptors could be powerful regulators of ongoing immune response.
We wish to use sophisticated mouse models and new in vivo imaging approaches to define the roles of subsets of dermal nociceptors, cationic neuropeptide substance P, dermal mast cells expressing the recently discovered receptor for cationic molecules Mas-related G protein-coupled receptor b2 (i.e., Mrgprb2), in a mouse model of AD that has many pathological, immunological, and gene expression similarities with the corresponding human disorder. We also will define the translational relevance of our mouse studies by performing parallel analyzes of nociceptors and mast cells in the lesional skin of patients from USA and France with clinically-established AD. To accomplish these goals, we have proposed herein a body of work that is solidly based on our preliminary data, with four Aims that will test innovative hypotheses by using informative genetic approaches, as well as new intravital imaging systems we recently developed.
This work thus will address significant gaps in our knowledge about the pathophysiology of AD and has the potential to identify such neuro-immune interactions as a promising new therapeutic target in AD and perhaps other allergic disorders.
Summary
Preserving skin homeostasis depends on complex interactions among structural cells, immune cells, and the environment. Dysregulation of this delicate equilibrium contributes to the development of type 2 immunity-associated skin inflammation (i.e., allergic skin inflammation), including atopic dermatitis (AD). The skin is a complex organ harboring various tissue-resident immune cells (e.g., dendritic cells, mast cells and macrophages) and innervated by a meshwork of sensory nerves, including those involved in nociception (i.e., nociceptors), which respond to injurious or potentially damaging stimuli by transmitting signals to the spinal cord and brain. Despite their role in the transmission of sensation, recent evidences have suggested that nociceptors could be powerful regulators of ongoing immune response.
We wish to use sophisticated mouse models and new in vivo imaging approaches to define the roles of subsets of dermal nociceptors, cationic neuropeptide substance P, dermal mast cells expressing the recently discovered receptor for cationic molecules Mas-related G protein-coupled receptor b2 (i.e., Mrgprb2), in a mouse model of AD that has many pathological, immunological, and gene expression similarities with the corresponding human disorder. We also will define the translational relevance of our mouse studies by performing parallel analyzes of nociceptors and mast cells in the lesional skin of patients from USA and France with clinically-established AD. To accomplish these goals, we have proposed herein a body of work that is solidly based on our preliminary data, with four Aims that will test innovative hypotheses by using informative genetic approaches, as well as new intravital imaging systems we recently developed.
This work thus will address significant gaps in our knowledge about the pathophysiology of AD and has the potential to identify such neuro-immune interactions as a promising new therapeutic target in AD and perhaps other allergic disorders.
Max ERC Funding
1 497 441 €
Duration
Start date: 2019-01-01, End date: 2023-12-31
