Project acronym ADHESWITCHES
Project Adhesion switches in cancer and development: from in vivo to synthetic biology
Researcher (PI) Mari Johanna Ivaska
Host Institution (HI) TURUN YLIOPISTO
Call Details Consolidator Grant (CoG), LS3, ERC-2013-CoG
Summary Integrins are transmembrane cell adhesion receptors controlling cell proliferation and migration. Our objective is to gain fundamentally novel mechanistic insight into the emerging new roles of integrins in cancer and to generate a road map of integrin dependent pathways critical in mammary gland development and integrin signalling thus opening new targets for therapeutic interventions. We will combine an in vivo based translational approach with cell and molecular biological studies aiming to identify entirely novel concepts in integrin function using cutting edge techniques and synthetic-biology tools.
The specific objectives are:
1) Integrin inactivation in branching morphogenesis and cancer invasion. Integrins regulate mammary gland development and cancer invasion but the role of integrin inactivating proteins in these processes is currently completely unknown. We will investigate this using genetically modified mice, ex-vivo organoid models and human tissues with the aim to identify beneficial combinational treatments against cancer invasion.
2) Endosomal adhesomes – cross-talk between integrin activity and integrin “inside-in signaling”. We hypothesize that endocytosed active integrins engage in specialized endosomal signaling that governs cell survival especially in cancer. RNAi cell arrays, super-resolution STED imaging and endosomal proteomics will be used to investigate integrin signaling in endosomes.
3) Spatio-temporal co-ordination of adhesion and endocytosis. Several cytosolic proteins compete for integrin binding to regulate activation, endocytosis and recycling. Photoactivatable protein-traps and predefined matrix micropatterns will be employed to mechanistically dissect the spatio-temporal dynamics and hierarchy of their recruitment.
We will employ innovative and unconventional techniques to address three major unanswered questions in the field and significantly advance our understanding of integrin function in development and cancer.
Summary
Integrins are transmembrane cell adhesion receptors controlling cell proliferation and migration. Our objective is to gain fundamentally novel mechanistic insight into the emerging new roles of integrins in cancer and to generate a road map of integrin dependent pathways critical in mammary gland development and integrin signalling thus opening new targets for therapeutic interventions. We will combine an in vivo based translational approach with cell and molecular biological studies aiming to identify entirely novel concepts in integrin function using cutting edge techniques and synthetic-biology tools.
The specific objectives are:
1) Integrin inactivation in branching morphogenesis and cancer invasion. Integrins regulate mammary gland development and cancer invasion but the role of integrin inactivating proteins in these processes is currently completely unknown. We will investigate this using genetically modified mice, ex-vivo organoid models and human tissues with the aim to identify beneficial combinational treatments against cancer invasion.
2) Endosomal adhesomes – cross-talk between integrin activity and integrin “inside-in signaling”. We hypothesize that endocytosed active integrins engage in specialized endosomal signaling that governs cell survival especially in cancer. RNAi cell arrays, super-resolution STED imaging and endosomal proteomics will be used to investigate integrin signaling in endosomes.
3) Spatio-temporal co-ordination of adhesion and endocytosis. Several cytosolic proteins compete for integrin binding to regulate activation, endocytosis and recycling. Photoactivatable protein-traps and predefined matrix micropatterns will be employed to mechanistically dissect the spatio-temporal dynamics and hierarchy of their recruitment.
We will employ innovative and unconventional techniques to address three major unanswered questions in the field and significantly advance our understanding of integrin function in development and cancer.
Max ERC Funding
1 887 910 €
Duration
Start date: 2014-05-01, End date: 2019-04-30
Project acronym Age Asymmetry
Project Age-Selective Segregation of Organelles
Researcher (PI) Pekka Aleksi Katajisto
Host Institution (HI) HELSINGIN YLIOPISTO
Call Details Starting Grant (StG), LS3, ERC-2015-STG
Summary Our tissues are constantly renewed by stem cells. Over time, stem cells accumulate cellular damage that will compromise renewal and results in aging. As stem cells can divide asymmetrically, segregation of harmful factors to the differentiating daughter cell could be one possible mechanism for slowing damage accumulation in the stem cell. However, current evidence for such mechanisms comes mainly from analogous findings in yeast, and studies have concentrated only on few types of cellular damage.
I hypothesize that the chronological age of a subcellular component is a proxy for all the damage it has sustained. In order to secure regeneration, mammalian stem cells may therefore specifically sort old cellular material asymmetrically. To study this, I have developed a novel strategy and tools to address the age-selective segregation of any protein in stem cell division. Using this approach, I have already discovered that stem-like cells of the human mammary epithelium indeed apportion chronologically old mitochondria asymmetrically in cell division, and enrich old mitochondria to the differentiating daughter cell. We will investigate the mechanisms underlying this novel phenomenon, and its relevance for mammalian aging.
We will first identify how old and young mitochondria differ, and how stem cells recognize them to facilitate the asymmetric segregation. Next, we will analyze the extent of asymmetric age-selective segregation by targeting several other subcellular compartments in a stem cell division. Finally, we will determine whether the discovered age-selective segregation is a general property of stem cell in vivo, and it's functional relevance for maintenance of stem cells and tissue regeneration. Our discoveries may open new possibilities to target aging associated functional decline by induction of asymmetric age-selective organelle segregation.
Summary
Our tissues are constantly renewed by stem cells. Over time, stem cells accumulate cellular damage that will compromise renewal and results in aging. As stem cells can divide asymmetrically, segregation of harmful factors to the differentiating daughter cell could be one possible mechanism for slowing damage accumulation in the stem cell. However, current evidence for such mechanisms comes mainly from analogous findings in yeast, and studies have concentrated only on few types of cellular damage.
I hypothesize that the chronological age of a subcellular component is a proxy for all the damage it has sustained. In order to secure regeneration, mammalian stem cells may therefore specifically sort old cellular material asymmetrically. To study this, I have developed a novel strategy and tools to address the age-selective segregation of any protein in stem cell division. Using this approach, I have already discovered that stem-like cells of the human mammary epithelium indeed apportion chronologically old mitochondria asymmetrically in cell division, and enrich old mitochondria to the differentiating daughter cell. We will investigate the mechanisms underlying this novel phenomenon, and its relevance for mammalian aging.
We will first identify how old and young mitochondria differ, and how stem cells recognize them to facilitate the asymmetric segregation. Next, we will analyze the extent of asymmetric age-selective segregation by targeting several other subcellular compartments in a stem cell division. Finally, we will determine whether the discovered age-selective segregation is a general property of stem cell in vivo, and it's functional relevance for maintenance of stem cells and tissue regeneration. Our discoveries may open new possibilities to target aging associated functional decline by induction of asymmetric age-selective organelle segregation.
Max ERC Funding
1 500 000 €
Duration
Start date: 2016-05-01, End date: 2021-04-30
Project acronym CORKtheCAMBIA
Project Thickening of plant organs by nested stem cells
Researcher (PI) Ari Pekka MÄHÖNEN
Host Institution (HI) HELSINGIN YLIOPISTO
Call Details Consolidator Grant (CoG), LS3, ERC-2018-COG
Summary Growth originates from meristems, where stem cells are located. Lateral meristems, which provide thickness to tree stems and other plant organs, include vascular cambium (produces xylem [wood] and phloem); and cork cambium (forms cork, a tough protective layer).
We recently identified the molecular mechanism that specifies stem cells of vascular cambium. Unexpectedly, this same set of experiments revealed also novel aspects of the regulation of cork cambium, a meristem whose development has remained unknown. CORKtheCAMBIA aims to identify the stem cells of cork cambium and reveal how they mechanistically regulate plant organ thickening. Thus, stemming from these novel unpublished findings and my matching expertise on plant stem cells and lateral growth, the timing is perfect to discover the molecular mechanism underlying specification of stem cells of cork cambium.
To identify the origin of stem cells of cork cambium, 1st-we will combine lineage tracing with a detailed molecular marker analysis. To deduce the cell dynamics of cork cambium, 2nd-we will follow regeneration of the stem cells after ablation of this meristem. To discover the molecular factors regulating the stem cell specification of cork cambium, 3rd-we will utilize molecular genetics and a novel method (inducible CRISPR/Cas9 mutant targeting) being developed in my lab. Since the lateral growth is orchestrated by two adjacent, nested meristems, cork and vascular cambia, the growth process must be tightly co-regulated. Thus, 4th-an in silico model of the intertwined growth process will be generated. By combining modelling with experimentation, we will uncover mechanistically how cork and vascular cambium coordinate lateral growth.
CORKtheCAMBIA will thus provide long-awaited insight into the regulatory mechanisms specifying the stem cells of lateral meristem as whole, lay the foundation for studies on radial thickening and facilitate rational manipulation of lateral meristems of crop plants and trees.
Summary
Growth originates from meristems, where stem cells are located. Lateral meristems, which provide thickness to tree stems and other plant organs, include vascular cambium (produces xylem [wood] and phloem); and cork cambium (forms cork, a tough protective layer).
We recently identified the molecular mechanism that specifies stem cells of vascular cambium. Unexpectedly, this same set of experiments revealed also novel aspects of the regulation of cork cambium, a meristem whose development has remained unknown. CORKtheCAMBIA aims to identify the stem cells of cork cambium and reveal how they mechanistically regulate plant organ thickening. Thus, stemming from these novel unpublished findings and my matching expertise on plant stem cells and lateral growth, the timing is perfect to discover the molecular mechanism underlying specification of stem cells of cork cambium.
To identify the origin of stem cells of cork cambium, 1st-we will combine lineage tracing with a detailed molecular marker analysis. To deduce the cell dynamics of cork cambium, 2nd-we will follow regeneration of the stem cells after ablation of this meristem. To discover the molecular factors regulating the stem cell specification of cork cambium, 3rd-we will utilize molecular genetics and a novel method (inducible CRISPR/Cas9 mutant targeting) being developed in my lab. Since the lateral growth is orchestrated by two adjacent, nested meristems, cork and vascular cambia, the growth process must be tightly co-regulated. Thus, 4th-an in silico model of the intertwined growth process will be generated. By combining modelling with experimentation, we will uncover mechanistically how cork and vascular cambium coordinate lateral growth.
CORKtheCAMBIA will thus provide long-awaited insight into the regulatory mechanisms specifying the stem cells of lateral meristem as whole, lay the foundation for studies on radial thickening and facilitate rational manipulation of lateral meristems of crop plants and trees.
Max ERC Funding
1 999 752 €
Duration
Start date: 2019-09-01, End date: 2024-08-31
Project acronym RevMito
Project Deciphering and reversing the consequences of mitochondrial DNA damage
Researcher (PI) Cory Dunn
Host Institution (HI) HELSINGIN YLIOPISTO
Call Details Starting Grant (StG), LS3, ERC-2014-STG
Summary Mitochondrial DNA (mtDNA) encodes several proteins playing key roles in bioenergetics. Pathological mutations of mtDNA can be inherited or may accumulate following treatment for viral infections or cancer. Furthermore, many organisms, including humans, accumulate significant mtDNA damage during their lifespan, and it is therefore possible that mtDNA mutations can promote the aging process.
There are no effective treatments for most diseases caused by mtDNA mutation. An understanding of the cellular consequences of mtDNA damage is clearly imperative. Toward this goal, we use the budding yeast Saccharomyces cerevisiae as a cellular model of mitochondrial dysfunction. Genetic manipulation and biochemical study of this organism is easily achieved, and many proteins and processes important for mitochondrial biogenesis were first uncovered and best characterized using this experimental system. Importantly, current evidence suggests that processes required for survival of cells lacking a mitochondrial genome are widely conserved between yeast and other organisms, making likely the application of our findings to human health.
We will study the repercussions of mtDNA damage by three different strategies. First, we will investigate the link between a conserved, nutrient-sensitive signalling pathway and the outcome of mtDNA loss, since much recent evidence points to modulation of such pathways as a potential approach to increase the fitness of cells with mtDNA damage. Second, we will explore the possibility that defects in cytosolic proteostasis are precipitated by mtDNA mutation. Third, we will apply the knowledge and concepts gained in S. cerevisiae to both candidate-based and unbiased searches for genes that determine the aftermath of severe mtDNA damage in human cells. Beyond the mechanistic knowledge of mitochondrial dysfunction that will emerge from this project, we expect to identify new avenues toward the treatment of mitochondrial disease.
Summary
Mitochondrial DNA (mtDNA) encodes several proteins playing key roles in bioenergetics. Pathological mutations of mtDNA can be inherited or may accumulate following treatment for viral infections or cancer. Furthermore, many organisms, including humans, accumulate significant mtDNA damage during their lifespan, and it is therefore possible that mtDNA mutations can promote the aging process.
There are no effective treatments for most diseases caused by mtDNA mutation. An understanding of the cellular consequences of mtDNA damage is clearly imperative. Toward this goal, we use the budding yeast Saccharomyces cerevisiae as a cellular model of mitochondrial dysfunction. Genetic manipulation and biochemical study of this organism is easily achieved, and many proteins and processes important for mitochondrial biogenesis were first uncovered and best characterized using this experimental system. Importantly, current evidence suggests that processes required for survival of cells lacking a mitochondrial genome are widely conserved between yeast and other organisms, making likely the application of our findings to human health.
We will study the repercussions of mtDNA damage by three different strategies. First, we will investigate the link between a conserved, nutrient-sensitive signalling pathway and the outcome of mtDNA loss, since much recent evidence points to modulation of such pathways as a potential approach to increase the fitness of cells with mtDNA damage. Second, we will explore the possibility that defects in cytosolic proteostasis are precipitated by mtDNA mutation. Third, we will apply the knowledge and concepts gained in S. cerevisiae to both candidate-based and unbiased searches for genes that determine the aftermath of severe mtDNA damage in human cells. Beyond the mechanistic knowledge of mitochondrial dysfunction that will emerge from this project, we expect to identify new avenues toward the treatment of mitochondrial disease.
Max ERC Funding
1 497 160 €
Duration
Start date: 2015-04-01, End date: 2020-03-31
Project acronym STEMpop
Project Mechanisms of stem cell population dynamics and reprogramming
Researcher (PI) Sara WICKSTRÖM
Host Institution (HI) HELSINGIN YLIOPISTO
Call Details Consolidator Grant (CoG), LS3, ERC-2017-COG
Summary How complex but stereotyped tissues are formed, maintained and regenerated through local growth, differentiation and remodeling is a fundamental open question in biology. Understanding how single cell behaviors are coordinated on the population level and how population-level dynamics is coupled to tissue architecture is required to resolve this question as well as to develop stem cell (SC) therapies and effective treatments against cancers.
As a self-renewing organ maintained by multiple distinct SC populations, the epidermis represents an outstanding, clinically highly relevant research paradigm to address this question. A key epidermal SC population are the hair follicle stem cells (HFSCs) that fuel hair follicle regeneration, repair epidermal injuries and, when deregulated, initiate carcinogenesis. The major obstacle in mechanistic understanding of HFSC regulation has been the lack of an in vitro culture system enabling their precise monitoring and manipulation. We have overcome this barrier by developing a method for long-term maintenance of multipotent HFSCs that recapitulates the complexity of HFSC fate decisions and dynamic crosstalk between HFSCs and their progeny.
This breakthrough invention puts me in the unique position to investigate how HFSCs self-organize into a network of SCs and progenitors through population-level signaling crosstalk and phenotypic plasticity. This project will uncover the spatiotemporal dynamics of HFSCs fate decisions and establish the role of the niche in this process (Aim1), decipher key gene-regulatory networks and epigenetic barriers that control phenotypic plasticity (Aim2), and discover druggable signaling networks that drive bi-directional reprogramming of HFSCs and their progeny (Aim3). By deconstructing complex tissue-level behaviors at an unprecedented spatiotemporal resolution this study has the potential to transform the fundaments of adult SC biology with immediate implications to regenerative medicine.
Summary
How complex but stereotyped tissues are formed, maintained and regenerated through local growth, differentiation and remodeling is a fundamental open question in biology. Understanding how single cell behaviors are coordinated on the population level and how population-level dynamics is coupled to tissue architecture is required to resolve this question as well as to develop stem cell (SC) therapies and effective treatments against cancers.
As a self-renewing organ maintained by multiple distinct SC populations, the epidermis represents an outstanding, clinically highly relevant research paradigm to address this question. A key epidermal SC population are the hair follicle stem cells (HFSCs) that fuel hair follicle regeneration, repair epidermal injuries and, when deregulated, initiate carcinogenesis. The major obstacle in mechanistic understanding of HFSC regulation has been the lack of an in vitro culture system enabling their precise monitoring and manipulation. We have overcome this barrier by developing a method for long-term maintenance of multipotent HFSCs that recapitulates the complexity of HFSC fate decisions and dynamic crosstalk between HFSCs and their progeny.
This breakthrough invention puts me in the unique position to investigate how HFSCs self-organize into a network of SCs and progenitors through population-level signaling crosstalk and phenotypic plasticity. This project will uncover the spatiotemporal dynamics of HFSCs fate decisions and establish the role of the niche in this process (Aim1), decipher key gene-regulatory networks and epigenetic barriers that control phenotypic plasticity (Aim2), and discover druggable signaling networks that drive bi-directional reprogramming of HFSCs and their progeny (Aim3). By deconstructing complex tissue-level behaviors at an unprecedented spatiotemporal resolution this study has the potential to transform the fundaments of adult SC biology with immediate implications to regenerative medicine.
Max ERC Funding
1 999 918 €
Duration
Start date: 2018-05-01, End date: 2023-04-30
