ERC FUNDED PROJECTS

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.

2 411 547 €

Start date: 2010-03-01, End date: 2015-02-28

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.

2 499 590 €

Start date: 2014-03-01, End date: 2019-02-28

The core function of all brains is to compute the current state of the world, compare it to the desired state of the world and select motor programs that drive behavior minimizing any mismatch. The circuits underlying these functions are the key to understand brains in general, but so far they are completely unknown. Three problems have hindered progress: 1) The animal’s desired state of the world is rarely known. 2) Most studies in simple models have focused on sensory driven, reflex-like processes, and not considered self-initiated behavior. 3) The circuits underlying complex behaviors in vertebrates are widely distributed, containing millions of neurons. With this proposal I aim at overcoming these problems using insects, whose tiny brains solve the same basic problems as our brains but with 100,000 times fewer cells. Moreover, the central complex, a single conserved brain region consisting of only a few thousand neurons, is crucial for sensory integration, motor control and state-dependent modulation, essentially being a ‘brain in the brain’. To simplify the problem further I will focus on navigation behavior. Here, the desired and actual states of the world are equal to the desired and current headings of the animal, with mismatches resulting in compensatory steering. I have previously shown how the central complex encodes the animal’s current heading. Now I will use behavioral training to generate animals with highly defined desired headings, and correlate neural activity with the animal’s ‘intentions’ and actions - at the level of identified neurons. To establish the involved conserved core circuitry valid across insects I will compare species with distinct lifestyles. Secondly, I will reveal how these circuits have evolved to account for each species’ unique ecology. The proposed work will provide a coherent framework to study key concepts of fundamental brain functions in unprecedented detail - using a single, conserved, but flexible neural circuit.

1 500 000 €

Start date: 2017-01-01, End date: 2021-12-31

Genome maintenance, chromatin remodelling and transcription are tightly linked biological processes that are currently poorly understood and vastly unexplored. Nucleotide excision repair (NER) is a major DNA repair pathway that mammalian cells employ to maintain their genome intact and faithfully transmit it into their progeny. Besides cancer and aging, however, defects in NER give rise to developmental disorders whose clinical heterogeneity and varying severity can only insufficiently be explained by the DNA repair defect. Recent work reveals that NER factors play a role, in addition to DNA repair, in transcription and the three-dimensional organization of our genome. Indeed, NER factors are now known to function in the regulation of gene expression, the transcriptional reprogramming of pluripotent stem cells and the fine-tuning of growth hormones during mammalian development. In this regard, the non-random organization of our genome, chromatin and the process of transcription itself are expected to play paramount roles in how NER factors coordinate, prioritize and execute their distinct tasks during development and disease progression. At present, however, no solid evidence exists as to how NER is functionally involved in such complex processes, what are the NER-associated protein complexes and underlying gene networks or how NER factors operate within the complex chromatin architecture. This is primarily due to our difficulties in dissecting the diverse functional contributions of NER proteins in an intact organism. Here, we propose to use a unique series of knock-in, transgenic and NER progeroid mice to decode the functional role of NER in mammals, thus paving the way for understanding how genome maintenance pathways are connected to developmental defects and disease mechanisms in vivo.

1 995 000 €

Start date: 2016-01-01, End date: 2020-12-31