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
Country Sweden
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 CYTRIX
Project Engineering Cytokines for Super-Affinity Binding to Matrix in Regenerative Medicine
Researcher (PI) Jeffrey Alan Hubbell
Host Institution (HI) ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE
Country Switzerland
Call Details Advanced Grant (AdG), LS7, ERC-2013-ADG
Summary In physiological situations, the extracellular matrix (ECM) sequesters cytokines, localizes them, and modulates their signaling. Thus, physiological signaling from cytokines occurs primarily when the cytokines are interacting with the ECM. In therapeutic use of cytokines, however, this interaction and balance have not been respected; rather the growth factors are merely injected or applied as soluble molecules, perhaps in controlled release forms. This has led to modest efficacy and substantial concerns on safety. Here, we will develop a protein engineering design for second-generation cytokines to lead to their super-affinity binding to ECM molecules in the targeted tissues; this would allow application to a tissue site to yield a tight association with ECM molecules there, turning the tissue itself into a reservoir for cytokine sequestration and presentation. To accomplish this, we have undertaken preliminary work screening a library of cytokines for extraordinarily high affinity binding to a library of ECM molecules. We have thereby identified a small peptide domain within placental growth factor-2 (PlGF-2), namely PlGF-2123-144, that displays super-affinity for a number of ECM proteins. Also in preliminary work, we have demonstrated that recombinant fusion of this domain to low-affinity binding cytokines, namely VEGF-A, PDGF-BB and BMP-2, confers super-affinity binding to ECM molecules and accentuates their functionality in vivo in regenerative medicine models. In the proposed project, based on this preliminary data, we will push forward this protein engineering design, pursuing super-affinity variants of VEGF-A and PDGF-BB in chronic wounds, TGF-beta3 and CXCL11 in skin scar reduction, FGF-18 in osteoarthritic cartilage repair and CXCL12 in stem cell recruitment to ischemic cardiac muscle. Thus, we seek to demonstrate a fundamentally new concept and platform for second-generation growth factor protein engineering.
Summary
In physiological situations, the extracellular matrix (ECM) sequesters cytokines, localizes them, and modulates their signaling. Thus, physiological signaling from cytokines occurs primarily when the cytokines are interacting with the ECM. In therapeutic use of cytokines, however, this interaction and balance have not been respected; rather the growth factors are merely injected or applied as soluble molecules, perhaps in controlled release forms. This has led to modest efficacy and substantial concerns on safety. Here, we will develop a protein engineering design for second-generation cytokines to lead to their super-affinity binding to ECM molecules in the targeted tissues; this would allow application to a tissue site to yield a tight association with ECM molecules there, turning the tissue itself into a reservoir for cytokine sequestration and presentation. To accomplish this, we have undertaken preliminary work screening a library of cytokines for extraordinarily high affinity binding to a library of ECM molecules. We have thereby identified a small peptide domain within placental growth factor-2 (PlGF-2), namely PlGF-2123-144, that displays super-affinity for a number of ECM proteins. Also in preliminary work, we have demonstrated that recombinant fusion of this domain to low-affinity binding cytokines, namely VEGF-A, PDGF-BB and BMP-2, confers super-affinity binding to ECM molecules and accentuates their functionality in vivo in regenerative medicine models. In the proposed project, based on this preliminary data, we will push forward this protein engineering design, pursuing super-affinity variants of VEGF-A and PDGF-BB in chronic wounds, TGF-beta3 and CXCL11 in skin scar reduction, FGF-18 in osteoarthritic cartilage repair and CXCL12 in stem cell recruitment to ischemic cardiac muscle. Thus, we seek to demonstrate a fundamentally new concept and platform for second-generation growth factor protein engineering.
Max ERC Funding
2 368 170 €
Duration
Start date: 2014-05-01, End date: 2019-04-30
