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 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 BBBARRIER
Project Mechanisms of regulation of the blood-brain barrier; towards opening and closing the barrier on demand
Researcher (PI) Björn Christer Betsholtz
Host Institution (HI) UPPSALA UNIVERSITET
Call Details Advanced Grant (AdG), LS4, ERC-2011-ADG_20110310
Summary In the bone-enclosed CNS, increased vascular permeability may cause life-threatening tissue swelling, and/or ischemia and inflammation which compromise tissue repair after trauma or stroke. The brain vasculature possesses several unique features collectively named the blood-brain barrier (BBB) in which passive permeability is almost completely abolished and replaced by a complex of specific transport mechanisms. The BBB is necessary to uphold the specific milieu necessary for neuronal function. Whereas breakdown of the BBB is part of many CNS diseases, including stroke, neuroinflammation, trauma and neurodegenerative disorders, its molecular mechanisms and consequences are unclear and debated. Conversely, the intact BBB is a huge obstacle for drug delivery to the brain. Research on the BBB therefore has two seemingly opposing aims: 1) to seal a damaged BBB and protect the brain from toxic blood products, and 2) to open the BBB “on demand” for drug delivery. A major problem in the BBB field has been the lack of in vivo animal models for molecular and functional studies. So far, available in vitro models are not recapitulating the in vivo BBB. Our recent work on mouse models lacking pericytes, a BBB-associated cell type, demonstrates a specific role for pericytes in the development and regulation of the mammalian BBB. These animal models are the first ones showing a general and significant BBB impairment in adulthood, and as such they provide a unique opportunity to address molecular mechanisms of BBB disruption in disease and in drug transport across the BBB. Importantly, the new models and tools that we have developed allow us to search for relevant druggable mechanisms and molecular targets in the BBB. The long-term goals of this proposal are to develop molecular strategies and tools to open and close the BBB “on demand” for drug delivery to the CNS, and to explore the importance and mechanisms of BBB dysfunction in neurodegenerative diseases and stroke.
Summary
In the bone-enclosed CNS, increased vascular permeability may cause life-threatening tissue swelling, and/or ischemia and inflammation which compromise tissue repair after trauma or stroke. The brain vasculature possesses several unique features collectively named the blood-brain barrier (BBB) in which passive permeability is almost completely abolished and replaced by a complex of specific transport mechanisms. The BBB is necessary to uphold the specific milieu necessary for neuronal function. Whereas breakdown of the BBB is part of many CNS diseases, including stroke, neuroinflammation, trauma and neurodegenerative disorders, its molecular mechanisms and consequences are unclear and debated. Conversely, the intact BBB is a huge obstacle for drug delivery to the brain. Research on the BBB therefore has two seemingly opposing aims: 1) to seal a damaged BBB and protect the brain from toxic blood products, and 2) to open the BBB “on demand” for drug delivery. A major problem in the BBB field has been the lack of in vivo animal models for molecular and functional studies. So far, available in vitro models are not recapitulating the in vivo BBB. Our recent work on mouse models lacking pericytes, a BBB-associated cell type, demonstrates a specific role for pericytes in the development and regulation of the mammalian BBB. These animal models are the first ones showing a general and significant BBB impairment in adulthood, and as such they provide a unique opportunity to address molecular mechanisms of BBB disruption in disease and in drug transport across the BBB. Importantly, the new models and tools that we have developed allow us to search for relevant druggable mechanisms and molecular targets in the BBB. The long-term goals of this proposal are to develop molecular strategies and tools to open and close the BBB “on demand” for drug delivery to the CNS, and to explore the importance and mechanisms of BBB dysfunction in neurodegenerative diseases and stroke.
Max ERC Funding
2 499 427 €
Duration
Start date: 2012-08-01, End date: 2017-07-31
Project acronym BETAIMAGE
Project An in vivo imaging approach to understand pancreatic beta-cell signal-transduction
Researcher (PI) Per-Olof Berggren
Host Institution (HI) KAROLINSKA INSTITUTET
Call Details Advanced Grant (AdG), LS4, ERC-2013-ADG
Summary The challenge in cell physiology/pathology today is to translate in vitro findings to the living organism. We have developed a unique approach where signal-transduction can be investigated in vivo non-invasively, longitudinally at single cell resolution, using the anterior chamber of the eye as a natural body window for imaging. We will use this approach to understand how the universally important and highly complex signal Ca2+ is regulated in the pancreatic beta-cell, while localized in the vascularized and innervated islet of Langerhans, and how that affects the insulin secretory machinery in vivo. Engrafted islets in the eye take on identical innervation- and vascularization patterns as those in the pancreas and are proficient in regulating glucose homeostasis in the animal. Since the pancreatic islet constitutes a micro-organ, this imaging approach offers a seminal model system to understand Ca2+ signaling in individual cells at the organ level in real life. We will test the hypothesis that the Ca2+-signal has a key role in pancreatic beta-cell function and survival in vivo and that perturbation in the Ca2+-signal serves as a common denominator for beta-cell pathology associated with impaired glucose homeostasis and diabetes. Of special interest is how innervation impacts on Ca2+-dynamics and the integration of autocrine, paracrine and endocrine signals in fine-tuning the Ca2+-signal with regard to beta-cell function and survival. We aim to define key defects in the machinery regulating Ca2+-dynamics in association with the autoimmune reaction, inflammation and obesity eventually resulting in diabetes. Our imaging platform will be applied to clarify in vivo regulation of Ca2+-dynamics in both healthy and diabetic human beta-cells. To define novel drugable targets for treatment of diabetes, it is crucial to identify similarities and differences in the molecular machinery regulating the in vivo Ca2+-signal in the human and in the rodent beta-cell.
Summary
The challenge in cell physiology/pathology today is to translate in vitro findings to the living organism. We have developed a unique approach where signal-transduction can be investigated in vivo non-invasively, longitudinally at single cell resolution, using the anterior chamber of the eye as a natural body window for imaging. We will use this approach to understand how the universally important and highly complex signal Ca2+ is regulated in the pancreatic beta-cell, while localized in the vascularized and innervated islet of Langerhans, and how that affects the insulin secretory machinery in vivo. Engrafted islets in the eye take on identical innervation- and vascularization patterns as those in the pancreas and are proficient in regulating glucose homeostasis in the animal. Since the pancreatic islet constitutes a micro-organ, this imaging approach offers a seminal model system to understand Ca2+ signaling in individual cells at the organ level in real life. We will test the hypothesis that the Ca2+-signal has a key role in pancreatic beta-cell function and survival in vivo and that perturbation in the Ca2+-signal serves as a common denominator for beta-cell pathology associated with impaired glucose homeostasis and diabetes. Of special interest is how innervation impacts on Ca2+-dynamics and the integration of autocrine, paracrine and endocrine signals in fine-tuning the Ca2+-signal with regard to beta-cell function and survival. We aim to define key defects in the machinery regulating Ca2+-dynamics in association with the autoimmune reaction, inflammation and obesity eventually resulting in diabetes. Our imaging platform will be applied to clarify in vivo regulation of Ca2+-dynamics in both healthy and diabetic human beta-cells. To define novel drugable targets for treatment of diabetes, it is crucial to identify similarities and differences in the molecular machinery regulating the in vivo Ca2+-signal in the human and in the rodent beta-cell.
Max ERC Funding
2 499 590 €
Duration
Start date: 2014-03-01, End date: 2019-02-28
Project acronym BODY-OWNERSHIP
Project Neural mechanisms of body ownership and the projection of ownership onto artificial bodies
Researcher (PI) H. Henrik Ehrsson
Host Institution (HI) KAROLINSKA INSTITUTET
Call Details Starting Grant (StG), LS4, ERC-2007-StG
Summary How do we recognize that our limbs are part of our own body, and why do we feel that one’s self is located inside the body? These fundamental questions have been discussed in theology, philosophy and psychology for millennia. The aim of my ground-breaking research programme is to identify the neuronal mechanisms that produce the sense of ownership of the body, and the processes responsible for the feeling that the self is located inside the physical body. To solve these questions I will adopt an inter-disciplinary approach using state-of-the-art methods from the fields of imaging neuroscience, experimental psychology, computer science and robotics. My first hypothesis is that the mechanism for body ownership is the integration of information from different sensory modalities (vision, touch and muscle sense) in multi-sensory brain areas (ventral premotor and intraparietal cortex). My second hypothesis is that the sense of where you are located in the environment is mediated by allocentric spatial representations in medial temporal lobes. To test this, I will use perceptual illusions and virtual-reality techniques that allow me to manipulate body ownership and the perceived location of the self, in conjunction with non-invasive recordings of brain activity in healthy humans. Functional magnetic resonance imaging and electroencephalography will be used to identify the neuronal correlates of ownership and ‘in-body experiences’, while transcranial magnetic stimulation will be used to examine the causal relationship between neural activity and ownership. It is no overstatement to say that my pioneering work could define a new sub-field in cognitive neuroscience dealing with how the brain represents the self. These basic scientific discoveries will be used in new frontier applications. For example, the development of a prosthetic limb that feels just like a real limb, and a method of controlling humanoid robots by the illusion of ‘becoming the robot’.
Summary
How do we recognize that our limbs are part of our own body, and why do we feel that one’s self is located inside the body? These fundamental questions have been discussed in theology, philosophy and psychology for millennia. The aim of my ground-breaking research programme is to identify the neuronal mechanisms that produce the sense of ownership of the body, and the processes responsible for the feeling that the self is located inside the physical body. To solve these questions I will adopt an inter-disciplinary approach using state-of-the-art methods from the fields of imaging neuroscience, experimental psychology, computer science and robotics. My first hypothesis is that the mechanism for body ownership is the integration of information from different sensory modalities (vision, touch and muscle sense) in multi-sensory brain areas (ventral premotor and intraparietal cortex). My second hypothesis is that the sense of where you are located in the environment is mediated by allocentric spatial representations in medial temporal lobes. To test this, I will use perceptual illusions and virtual-reality techniques that allow me to manipulate body ownership and the perceived location of the self, in conjunction with non-invasive recordings of brain activity in healthy humans. Functional magnetic resonance imaging and electroencephalography will be used to identify the neuronal correlates of ownership and ‘in-body experiences’, while transcranial magnetic stimulation will be used to examine the causal relationship between neural activity and ownership. It is no overstatement to say that my pioneering work could define a new sub-field in cognitive neuroscience dealing with how the brain represents the self. These basic scientific discoveries will be used in new frontier applications. For example, the development of a prosthetic limb that feels just like a real limb, and a method of controlling humanoid robots by the illusion of ‘becoming the robot’.
Max ERC Funding
909 850 €
Duration
Start date: 2008-12-01, End date: 2013-11-30
Project acronym F12
Project Factor XII and the contact system:
cross-talk between thrombosis and inflammation
Researcher (PI) Hans Thomas Renné
Host Institution (HI) KAROLINSKA INSTITUTET
Call Details Starting Grant (StG), LS4, ERC-2012-StG_20111109
Summary Combinations of proinflammatory and procoagulant reactions are the unifying principle for a variety of disorders affecting the cardiovascular system. Factor XII (FXII, Hageman factor) is a plasma protease that initiates the contact system. This system starts a cascade of procoagulant and proinflammatory reactions via the intrinsic pathway of coagulation, and the bradykinin-producing kallikrein-kinin system, respectively. The biochemistry of the contact system in vitro is well understood, however its in vivo functions are just beginning to emerge.
We have previously demonstrated that FXII is essential for thrombus formation while being dispensable for hemostatic processes that terminate blood loss. Challenging the dogma of a coagulation balance, targeting factor XII protected from cerebral ischemia without interfering with hemostasis. In contrast, excess FXII activity is associated with a life threatening inflammatory disorder, Hereditary angioedema. We recently have identified platelet polyphosphate (an inorganic polymer) and mast cell heparin as in vivo FXII activators with implications on the initiation of thrombosis and edema.
The current investigations will explore roles of the FXII-driven contact system at the intersection of procoagulant and proinflammatory pathways using genetically altered murine models. We aim to understand activation, regulation and functions of the system for ischemic heart disease, vascular leakage in Hereditary angioedema, allergic airway inflammation as well as procoagulant reactions driven by bacterial infections in skin and lung.
A key aspect of this proposal will be analysis of common principles, interactions and cross-talk between coagulation and inflammation, to identify novel therapeutic targets. Elucidating the FXII-driven contact system offers the exciting opportunity to develop strategies for safe interference with both thrombotic and inflammatory diseases.
Summary
Combinations of proinflammatory and procoagulant reactions are the unifying principle for a variety of disorders affecting the cardiovascular system. Factor XII (FXII, Hageman factor) is a plasma protease that initiates the contact system. This system starts a cascade of procoagulant and proinflammatory reactions via the intrinsic pathway of coagulation, and the bradykinin-producing kallikrein-kinin system, respectively. The biochemistry of the contact system in vitro is well understood, however its in vivo functions are just beginning to emerge.
We have previously demonstrated that FXII is essential for thrombus formation while being dispensable for hemostatic processes that terminate blood loss. Challenging the dogma of a coagulation balance, targeting factor XII protected from cerebral ischemia without interfering with hemostasis. In contrast, excess FXII activity is associated with a life threatening inflammatory disorder, Hereditary angioedema. We recently have identified platelet polyphosphate (an inorganic polymer) and mast cell heparin as in vivo FXII activators with implications on the initiation of thrombosis and edema.
The current investigations will explore roles of the FXII-driven contact system at the intersection of procoagulant and proinflammatory pathways using genetically altered murine models. We aim to understand activation, regulation and functions of the system for ischemic heart disease, vascular leakage in Hereditary angioedema, allergic airway inflammation as well as procoagulant reactions driven by bacterial infections in skin and lung.
A key aspect of this proposal will be analysis of common principles, interactions and cross-talk between coagulation and inflammation, to identify novel therapeutic targets. Elucidating the FXII-driven contact system offers the exciting opportunity to develop strategies for safe interference with both thrombotic and inflammatory diseases.
Max ERC Funding
1 488 780 €
Duration
Start date: 2013-08-01, End date: 2018-07-31
Project acronym GENE TARGET T2D
Project General and targeted approaches to unravel the molecular causes of type 2 diabetes
Researcher (PI) Leif Christer Groop
Host Institution (HI) LUNDS UNIVERSITET
Call Details Advanced Grant (AdG), LS4, ERC-2010-AdG_20100317
Summary Type 2 diabetes (T2D) affects worldwide at present about 250 million patients and an estimated 380 million in 2025. This epidemic has been ascribed to a collision between genes and an affluent society. Genetics of T2D has during recent years identified > 30 variants increasing susceptibility to T2D. Yet, these variants explain only 15% of the heritability of T2D. One reason could be that whole genome association studies can only detect common variants whereas identification of rare variants with stronger effects would require sequencing. A large part of this application is devoted to sequencing of affected family members from unique large pedigrees traced back to common ancestors around 1600. The advantage of using families is that identified variants can be tested for segregation with the trait. Genetic variants can influence expression of a gene in an allele specific manner. This will be explored by combining exome sequencing with sequencing of RNA from human islets.
Impaired effects of the incretin hormones GLP-1 and GIP on the pancreatic islets represent central defects in T2D. Variants in the TCF7L2 and GIPR genes contribute to these defects. I will here explore the molecular mechanisms by which TCF7L2, the strongest T2D gene, causes T2D. GIP has unprecedented effects not only on islet function but also on body composition, blood flow and vascular complications in T2D. This application explores these effects and will test whether manipulation of GIP can mimic the normalization of glucose tolerance seen after gastric bypass surgery.
Taken together, these general and targeted approaches are expected not only to provide new insights into the causes of T2D but also contribute with vital information for development of new treatments for T2D.
Summary
Type 2 diabetes (T2D) affects worldwide at present about 250 million patients and an estimated 380 million in 2025. This epidemic has been ascribed to a collision between genes and an affluent society. Genetics of T2D has during recent years identified > 30 variants increasing susceptibility to T2D. Yet, these variants explain only 15% of the heritability of T2D. One reason could be that whole genome association studies can only detect common variants whereas identification of rare variants with stronger effects would require sequencing. A large part of this application is devoted to sequencing of affected family members from unique large pedigrees traced back to common ancestors around 1600. The advantage of using families is that identified variants can be tested for segregation with the trait. Genetic variants can influence expression of a gene in an allele specific manner. This will be explored by combining exome sequencing with sequencing of RNA from human islets.
Impaired effects of the incretin hormones GLP-1 and GIP on the pancreatic islets represent central defects in T2D. Variants in the TCF7L2 and GIPR genes contribute to these defects. I will here explore the molecular mechanisms by which TCF7L2, the strongest T2D gene, causes T2D. GIP has unprecedented effects not only on islet function but also on body composition, blood flow and vascular complications in T2D. This application explores these effects and will test whether manipulation of GIP can mimic the normalization of glucose tolerance seen after gastric bypass surgery.
Taken together, these general and targeted approaches are expected not only to provide new insights into the causes of T2D but also contribute with vital information for development of new treatments for T2D.
Max ERC Funding
2 499 480 €
Duration
Start date: 2011-05-01, End date: 2016-04-30
Project acronym HUFATREG
Project Adipose tissue mass regulation in lean and obese individuals
Researcher (PI) Kirsty Lee Spalding
Host Institution (HI) KAROLINSKA INSTITUTET
Call Details Starting Grant (StG), LS4, ERC-2010-StG_20091118
Summary Owing to the increase in obesity, life expectancy may start to decrease in developed countries for the first time in recent history. In humans the generation of fat cells (adipocytes) is a major factor behind the growth of adipose tissue during childhood. The factors determining the fat mass in adults, however, are not fully understood. Increased fat storage in fully differentiated adipocytes, resulting in enlarged fat cells, is well documented and thought to be the most important mechanism whereby fat depots increase in adults. Very little is known about the maintenance of fat cells (adipocytes) in humans, how different fat depots are maintained and how (or if) this is altered in obesity. Recently I developed a method that is based on the incorporation of 14C from nuclear bomb tests into genomic DNA, which allows for the analysis of cell and tissue turnover in humans. Using this novel methodology we now have a strategy for studying cell turnover in humans. One tissue of great interest and significant clinical relevance is adipose tissue. Excess adipose tissue, resulting in obesity, is currently one of the most serious threats to human health on a global level. The current proposal aims to determine the dynamics of human adipose tissue maintenance and investigate any differences in regulation of the fat mass in lean and obese individuals. Understanding the dynamics of adipocyte turnover may shed new light on potential treatments for obesity.
Summary
Owing to the increase in obesity, life expectancy may start to decrease in developed countries for the first time in recent history. In humans the generation of fat cells (adipocytes) is a major factor behind the growth of adipose tissue during childhood. The factors determining the fat mass in adults, however, are not fully understood. Increased fat storage in fully differentiated adipocytes, resulting in enlarged fat cells, is well documented and thought to be the most important mechanism whereby fat depots increase in adults. Very little is known about the maintenance of fat cells (adipocytes) in humans, how different fat depots are maintained and how (or if) this is altered in obesity. Recently I developed a method that is based on the incorporation of 14C from nuclear bomb tests into genomic DNA, which allows for the analysis of cell and tissue turnover in humans. Using this novel methodology we now have a strategy for studying cell turnover in humans. One tissue of great interest and significant clinical relevance is adipose tissue. Excess adipose tissue, resulting in obesity, is currently one of the most serious threats to human health on a global level. The current proposal aims to determine the dynamics of human adipose tissue maintenance and investigate any differences in regulation of the fat mass in lean and obese individuals. Understanding the dynamics of adipocyte turnover may shed new light on potential treatments for obesity.
Max ERC Funding
1 500 000 €
Duration
Start date: 2011-04-01, End date: 2017-03-31
Project acronym ICEBERG
Project Discovery of Type 2 Diabetes Targets
Researcher (PI) Juleen Rae Zierath
Host Institution (HI) KAROLINSKA INSTITUTET
Call Details Advanced Grant (AdG), LS4, ERC-2008-AdG
Summary This proposal is focused on the identification and biological validation of the metabolic pathways and key regulatory genes that control insulin sensitivity in Type 2 diabetes mellitus (T2DM). We are focusing on skeletal muscle because it is quantitatively the most important tissue involved in maintaining glucose homeostasis under insulin-stimulated conditions and it is a major site of insulin resistance in T2DM. Our central hypothesis is that alterations in insulin signal transduction to glucose transport contribute to the profound impairment in whole body glucose homeostasis and T2DM pathogenesis. Identification of the defects in T2DM can lead to the development of new therapeutic strategies to prevent and cure this disease. The proposal is divided into two main objectives: We will apply: 1) target identification platforms including microarray, proteomics and bioinformatics to identify dysregulated genes in normal glucose tolerant versus T2DM subjects or genetically modified model systems and 2) functional genomics to assign a physiological role of the identified targets in Aim 1 using cellular and whole-body approaches. We will focus on the mitogen-activated protein kinase family, the energy-sensing enzyme AMP-activated protein kinase, and the lipid intermediate metabolizing enzyme diacylglycerol kinase delta. Our previous work indicates that these candidates play a role in the regulation of glucose metabolism, triglyceride storage, and energy homeostasis.
Summary
This proposal is focused on the identification and biological validation of the metabolic pathways and key regulatory genes that control insulin sensitivity in Type 2 diabetes mellitus (T2DM). We are focusing on skeletal muscle because it is quantitatively the most important tissue involved in maintaining glucose homeostasis under insulin-stimulated conditions and it is a major site of insulin resistance in T2DM. Our central hypothesis is that alterations in insulin signal transduction to glucose transport contribute to the profound impairment in whole body glucose homeostasis and T2DM pathogenesis. Identification of the defects in T2DM can lead to the development of new therapeutic strategies to prevent and cure this disease. The proposal is divided into two main objectives: We will apply: 1) target identification platforms including microarray, proteomics and bioinformatics to identify dysregulated genes in normal glucose tolerant versus T2DM subjects or genetically modified model systems and 2) functional genomics to assign a physiological role of the identified targets in Aim 1 using cellular and whole-body approaches. We will focus on the mitogen-activated protein kinase family, the energy-sensing enzyme AMP-activated protein kinase, and the lipid intermediate metabolizing enzyme diacylglycerol kinase delta. Our previous work indicates that these candidates play a role in the regulation of glucose metabolism, triglyceride storage, and energy homeostasis.
Max ERC Funding
2 500 000 €
Duration
Start date: 2009-01-01, End date: 2013-12-31
Project acronym LEUKEMIABARRIER
Project The Leukemia-Initiating Cell: Genetic Determinants, Escape Mechanisms and Ontogenic Influence
Researcher (PI) David Bryder
Host Institution (HI) LUNDS UNIVERSITET
Call Details Consolidator Grant (CoG), LS4, ERC-2013-CoG
Summary Acute myeloid leukemia (AML) is the most common malignant myeloid disorder in adults and strongly associated in incidence to advanced age. AML arises from immature hematopoietic progenitor cells via a sequential multistep process, but the nature of these steps remains to a large extent unknown. Therefore, while significant efforts have previously been invested in characterizing the molecular properties of late-stage AML, as diagnosed in patients, less information is available on the events that underlie leukemia initiation and progression. This includes the identity of potential mechanisms that restrict or eradicate developing leukemic cells; hurdles evaded at some point in time for AML to occur.
We have developed an inducible transgenic mouse model of AML that, when combined with high-resolution cell fractionation of primitive hematopoietic progenitor cells, offers a unique opportunity to track development of AML from the very first stages of cancer development. Using this, I propose to: 1) Identify and functionally validate molecular determinants that underlie why only some hematopoietic progenitor cells progress into AML, 2) To explore the extent and identity of immune surveillance/editing that accompany progression into AML, and 3) By building on my previous work on hematopoietic aging, to explore AML progression in the context of aging.
I anticipate the LEUKEMIABARRIER project to generate novel basic knowledge, not excluding with clinical relevance, with the potential to open up several new fields for further studies. This includes identification of novel cell-intrinsic regulators and immune responses, their underlying mechanisms, and their relationship to the increased incidence of AML with age.
Summary
Acute myeloid leukemia (AML) is the most common malignant myeloid disorder in adults and strongly associated in incidence to advanced age. AML arises from immature hematopoietic progenitor cells via a sequential multistep process, but the nature of these steps remains to a large extent unknown. Therefore, while significant efforts have previously been invested in characterizing the molecular properties of late-stage AML, as diagnosed in patients, less information is available on the events that underlie leukemia initiation and progression. This includes the identity of potential mechanisms that restrict or eradicate developing leukemic cells; hurdles evaded at some point in time for AML to occur.
We have developed an inducible transgenic mouse model of AML that, when combined with high-resolution cell fractionation of primitive hematopoietic progenitor cells, offers a unique opportunity to track development of AML from the very first stages of cancer development. Using this, I propose to: 1) Identify and functionally validate molecular determinants that underlie why only some hematopoietic progenitor cells progress into AML, 2) To explore the extent and identity of immune surveillance/editing that accompany progression into AML, and 3) By building on my previous work on hematopoietic aging, to explore AML progression in the context of aging.
I anticipate the LEUKEMIABARRIER project to generate novel basic knowledge, not excluding with clinical relevance, with the potential to open up several new fields for further studies. This includes identification of novel cell-intrinsic regulators and immune responses, their underlying mechanisms, and their relationship to the increased incidence of AML with age.
Max ERC Funding
1 999 714 €
Duration
Start date: 2014-07-01, End date: 2019-06-30
