Project acronym GLITTER
Project Glioblastoma Inhibition: Targeting Tumour-derived Extracellular-Vesicle Driven Cell-Recruitment
Researcher (PI) Thomas Wurdinger
Host Institution (HI) STICHTING VUMC
Call Details Starting Grant (StG), LS4, ERC-2013-StG
Summary Glioblastomas (GBMs) are malignant brain tumours and among the most aggressive human cancers. GBMs patients have an extremely poor survival rate due to a complete absence of adequate therapies capable of efficiently targeting GBM cells inside the brain. Recently, we demonstrated that GBM cells release pro-tumoural extracellular vesicles (EVs) into the bloodstream, which emerged as important intermediates in communication with distant peripheral cells in the body. Of note, the distribution of GBM-derived EVs can now be monitored in vivo by employing a novel Cre/LoxP mouse reporter model. This sophisticated imaging model enables the visualisation of normal peripheral cells that have taken up circulating GBM-derived EVs and allows for subsequent tracking of the recruitment of these cells to the tumour. Recent studies have shown that GBM-derived EVs have the capability to manipulate non-neoplastic cells, exploiting them for tumour expansion. Moreover, we have preliminary evidence that GBM-derived EV receptor pathways can be identified and blocked, possibly causing stagnation of GBM tumour growth by preventing recruitment of essential support cells. We aim at identifying these pathways using unbiased RNAi screening, followed by interference with pro-tumoural cell recruitment, using small molecule drugs in our GBM in vivo models. Finally, circulating GBM-derived EVs and their RNA content are also efficiently captured and internalised by blood platelets (PLTs) that can act as efficient EV carriers. Hence, tumour-derived RNA in circulating EVs and PLTs, isolated from the blood of GBM mouse models and patients, may serve as non-invasive biomarkers and companion diagnostics platform. GLITTER aims to; 1) Analyse in detail the EV-driven recruitment and signalling of essential GBM support cells; 2) Halt GBM tumour growth by interference with EV-mediated recruitment of pro-tumoural non-neoplastic cells; 3) Validate the EV/PLT-based diagnostic platform.
Summary
Glioblastomas (GBMs) are malignant brain tumours and among the most aggressive human cancers. GBMs patients have an extremely poor survival rate due to a complete absence of adequate therapies capable of efficiently targeting GBM cells inside the brain. Recently, we demonstrated that GBM cells release pro-tumoural extracellular vesicles (EVs) into the bloodstream, which emerged as important intermediates in communication with distant peripheral cells in the body. Of note, the distribution of GBM-derived EVs can now be monitored in vivo by employing a novel Cre/LoxP mouse reporter model. This sophisticated imaging model enables the visualisation of normal peripheral cells that have taken up circulating GBM-derived EVs and allows for subsequent tracking of the recruitment of these cells to the tumour. Recent studies have shown that GBM-derived EVs have the capability to manipulate non-neoplastic cells, exploiting them for tumour expansion. Moreover, we have preliminary evidence that GBM-derived EV receptor pathways can be identified and blocked, possibly causing stagnation of GBM tumour growth by preventing recruitment of essential support cells. We aim at identifying these pathways using unbiased RNAi screening, followed by interference with pro-tumoural cell recruitment, using small molecule drugs in our GBM in vivo models. Finally, circulating GBM-derived EVs and their RNA content are also efficiently captured and internalised by blood platelets (PLTs) that can act as efficient EV carriers. Hence, tumour-derived RNA in circulating EVs and PLTs, isolated from the blood of GBM mouse models and patients, may serve as non-invasive biomarkers and companion diagnostics platform. GLITTER aims to; 1) Analyse in detail the EV-driven recruitment and signalling of essential GBM support cells; 2) Halt GBM tumour growth by interference with EV-mediated recruitment of pro-tumoural non-neoplastic cells; 3) Validate the EV/PLT-based diagnostic platform.
Max ERC Funding
1 299 292 €
Duration
Start date: 2014-02-01, End date: 2019-01-31
Project acronym MEMPART
Project Membrane partitioning of homologous proteins
Researcher (PI) Geert Van Den Bogaart
Host Institution (HI) STICHTING KATHOLIEKE UNIVERSITEIT
Call Details Starting Grant (StG), LS1, ERC-2013-StG
Summary My goal is to elucidate how structurally closely-related proteins are selectively partitioned in distinct membrane domains that allow localization, clustering and segregation of specific cellular activities. Although many of the mechanisms that govern membrane organization are increasingly well understood, such as lipid ‘rafts’ or protein-anchoring to the cortical cytoskeleton, these mechanisms are not sufficiently specific to account for the partitioning of closely homologous proteins in separate membrane domains. I believe that the observed highly selective membrane partitioning can only be explained by the combined action of protein-protein and protein-lipid interactions and thermodynamic properties of the membrane (length, charge, degree of hydrophobicity). I aim to gain a full understanding of how homologous proteins partition in distinct functional membrane domains by studying SNARE proteins as a model system. Different SNAREs partition in different domains with different degrees of overlap in the plasma membrane where they catalyze the final membrane fusion steps of various exocytotic pathways. I will employ quantitative super-resolution microscopy to study the effects of selective (biochemical and genetic) perturbations on SNARE partitioning in both precisely controllable artificial membranes and in PC12 cells. This will allow me to elucidate the mechanisms, contributions and interplay of individual membrane clustering mechanisms in SNARE domain organization. I then plan to demonstrate that the mechanisms of SNARE partitioning explain the membrane organization of other (homologous) proteins as well. My ultimate ambitious goal is to generate a complete model of how proteins are organized in biological membranes. I anticipate that my findings will uncover new and general mechanisms of membrane organization and, since membranes are involved in almost all cellular processes, my work may have impact on virtually all areas of the health and life sciences.
Summary
My goal is to elucidate how structurally closely-related proteins are selectively partitioned in distinct membrane domains that allow localization, clustering and segregation of specific cellular activities. Although many of the mechanisms that govern membrane organization are increasingly well understood, such as lipid ‘rafts’ or protein-anchoring to the cortical cytoskeleton, these mechanisms are not sufficiently specific to account for the partitioning of closely homologous proteins in separate membrane domains. I believe that the observed highly selective membrane partitioning can only be explained by the combined action of protein-protein and protein-lipid interactions and thermodynamic properties of the membrane (length, charge, degree of hydrophobicity). I aim to gain a full understanding of how homologous proteins partition in distinct functional membrane domains by studying SNARE proteins as a model system. Different SNAREs partition in different domains with different degrees of overlap in the plasma membrane where they catalyze the final membrane fusion steps of various exocytotic pathways. I will employ quantitative super-resolution microscopy to study the effects of selective (biochemical and genetic) perturbations on SNARE partitioning in both precisely controllable artificial membranes and in PC12 cells. This will allow me to elucidate the mechanisms, contributions and interplay of individual membrane clustering mechanisms in SNARE domain organization. I then plan to demonstrate that the mechanisms of SNARE partitioning explain the membrane organization of other (homologous) proteins as well. My ultimate ambitious goal is to generate a complete model of how proteins are organized in biological membranes. I anticipate that my findings will uncover new and general mechanisms of membrane organization and, since membranes are involved in almost all cellular processes, my work may have impact on virtually all areas of the health and life sciences.
Max ERC Funding
1 500 000 €
Duration
Start date: 2013-12-01, End date: 2018-11-30
Project acronym PROLONGBILESIGNALING
Project Improving Metabolism via Prolonged Bile Acid Signalling
targeting hepatic bile acid uptake to fight metabolic diseases
Researcher (PI) Konstantijn Van De Graaf
Host Institution (HI) ACADEMISCH MEDISCH CENTRUM BIJ DE UNIVERSITEIT VAN AMSTERDAM
Call Details Starting Grant (StG), LS4, ERC-2013-StG
Summary Bile acids play a pivotal role in energy supply as they facilitate the solubilization and absorption of fat in the intestine. Furthermore, bile acids are recently identified as important signalling molecules regulating glucose metabolism, inflammation and energy expenditure. Targeting bile acid signalling is, therefore, appealing to treat metabolic diseases such as diabetes and atherosclerosis. These disorders are potentially affecting >1 billion individuals worldwide and current options to treat them remain insufficient. I postulate that the hepatic bile acid uptake transporter NTCP (gene name SLC10A1) provides an excellent novel target to improve human health as it determines the duration of bile acid signalling by controlling how fast bile acids are removed from serum after a meal. In this proposal I will elucidate the contribution of bile acid dynamics to energy homeostasis and metabolism and identify the molecular mechanisms that regulate NTCP. My aim is to generate novel strategies to reduce hepatic bile acid uptake to prolong bile-acid signalling and increase energy expenditure, improve glucose handling and reduce atherosclerosis.
My key objectives are:
1. to determine the consequence of NTCP modulation on systemic bile acid dynamics, glucose and energy metabolism in animal models. To this end, I will perform careful metabolic analysis of a unique Slc10a1 knockout model in combination with diet-induced and genetic models for atherosclerosis and diabetes.
2. to identify novel means to inhibit NTCP-mediated bile acid uptake. To this end, I will make use of a FRET-based bile acid sensor that I recently developed to characterize the molecular regulation of hepatic bile acid uptake and to identify FDA-approved drugs that inhibit NTCP-mediated bile acid uptake.
This will establish my new research line on serum bile acid dynamics and ultimately provide new ways to treat metabolic diseases related to disturbed bile acid, lipid, glucose and energy homeostasis.
Summary
Bile acids play a pivotal role in energy supply as they facilitate the solubilization and absorption of fat in the intestine. Furthermore, bile acids are recently identified as important signalling molecules regulating glucose metabolism, inflammation and energy expenditure. Targeting bile acid signalling is, therefore, appealing to treat metabolic diseases such as diabetes and atherosclerosis. These disorders are potentially affecting >1 billion individuals worldwide and current options to treat them remain insufficient. I postulate that the hepatic bile acid uptake transporter NTCP (gene name SLC10A1) provides an excellent novel target to improve human health as it determines the duration of bile acid signalling by controlling how fast bile acids are removed from serum after a meal. In this proposal I will elucidate the contribution of bile acid dynamics to energy homeostasis and metabolism and identify the molecular mechanisms that regulate NTCP. My aim is to generate novel strategies to reduce hepatic bile acid uptake to prolong bile-acid signalling and increase energy expenditure, improve glucose handling and reduce atherosclerosis.
My key objectives are:
1. to determine the consequence of NTCP modulation on systemic bile acid dynamics, glucose and energy metabolism in animal models. To this end, I will perform careful metabolic analysis of a unique Slc10a1 knockout model in combination with diet-induced and genetic models for atherosclerosis and diabetes.
2. to identify novel means to inhibit NTCP-mediated bile acid uptake. To this end, I will make use of a FRET-based bile acid sensor that I recently developed to characterize the molecular regulation of hepatic bile acid uptake and to identify FDA-approved drugs that inhibit NTCP-mediated bile acid uptake.
This will establish my new research line on serum bile acid dynamics and ultimately provide new ways to treat metabolic diseases related to disturbed bile acid, lipid, glucose and energy homeostasis.
Max ERC Funding
1 489 320 €
Duration
Start date: 2013-12-01, End date: 2018-11-30
Project acronym Trxn-PURGE
Project Mechanisms of transcription in HIV latency; novel strategies to activate
Researcher (PI) Tokameh Mahmoudi
Host Institution (HI) ERASMUS UNIVERSITAIR MEDISCH CENTRUM ROTTERDAM
Call Details Starting Grant (StG), LS1, ERC-2013-StG
Summary The persistence of a transcriptionally competent but latent HIV infected memory CD4+T cell reservoir, despite the effectiveness of Highly Active Antiretroviral therapy (HAART) against active virus, presents the main impediment to HIV eradication. A novel concept in HIV eradication is to activate latent virus to subsequently eliminate with HAART. Much effort has gone into identification of protein complexes that regulate HIV LTR activity. Strategies have mainly relied on candidate approaches. However, due to technical limitations, comprehensive unbiased identification of host proteins associated with and necessary for silencing of the latent HIV LTR has not been possible.
Trxn-PURGE proposes a novel multidisciplinary approach combining current knowledge of HIV transcription and new insights into eradication strategies with state of the art high though-put approaches, mycology, virology, genetics and conventional biochemistry to identify novel players in maintenance and activation of HIV transcriptional latency. We will: 1. Use a novel unbiased strategy to identify the in vivo latent LTR-bound protein complex directly from infected T cells. 2. Conduct a cell-based high-throughput Haploid genetic screen to identify novel factors essential for maintenance of HIV latency. 3. Having identified three putative activators from a limited library, we will perform a large-scale screen with unbiased library of fungal supernatants to identify molecules capable of activation of latent HIV.
These parallel approaches will identify novel molecular targets and molecules in activation of HIV transcriptional latency, which we will functionally and mechanistically characterize alone and in synergy with known compounds implicated in latent LTR activation in both 4. T cell lines and 5. primary human CD4+T cells harboring latent HIV.
By unravelling its molecular mechanisms, Trxn-PURGE will set the stage for the development of a clinical combinatorial therapy to activate latent HIV.
Summary
The persistence of a transcriptionally competent but latent HIV infected memory CD4+T cell reservoir, despite the effectiveness of Highly Active Antiretroviral therapy (HAART) against active virus, presents the main impediment to HIV eradication. A novel concept in HIV eradication is to activate latent virus to subsequently eliminate with HAART. Much effort has gone into identification of protein complexes that regulate HIV LTR activity. Strategies have mainly relied on candidate approaches. However, due to technical limitations, comprehensive unbiased identification of host proteins associated with and necessary for silencing of the latent HIV LTR has not been possible.
Trxn-PURGE proposes a novel multidisciplinary approach combining current knowledge of HIV transcription and new insights into eradication strategies with state of the art high though-put approaches, mycology, virology, genetics and conventional biochemistry to identify novel players in maintenance and activation of HIV transcriptional latency. We will: 1. Use a novel unbiased strategy to identify the in vivo latent LTR-bound protein complex directly from infected T cells. 2. Conduct a cell-based high-throughput Haploid genetic screen to identify novel factors essential for maintenance of HIV latency. 3. Having identified three putative activators from a limited library, we will perform a large-scale screen with unbiased library of fungal supernatants to identify molecules capable of activation of latent HIV.
These parallel approaches will identify novel molecular targets and molecules in activation of HIV transcriptional latency, which we will functionally and mechanistically characterize alone and in synergy with known compounds implicated in latent LTR activation in both 4. T cell lines and 5. primary human CD4+T cells harboring latent HIV.
By unravelling its molecular mechanisms, Trxn-PURGE will set the stage for the development of a clinical combinatorial therapy to activate latent HIV.
Max ERC Funding
1 499 942 €
Duration
Start date: 2014-02-01, End date: 2019-01-31
