The brain is composed of a set of areas specialized in specific computations whose outputs need to be transferred to other specialized areas for cognition to emerge. To account for context-dependent behaviors, the information has to be flexibly routed through the fixed anatomy of the brain. The aim of my proposal is to test a general framework for flexible communication between brain areas based on nested oscillations which I recently developed. The general idea is that internally-driven slow oscillations (30Hz), nested in the slow oscillations, can then be directed to task-relevant areas of the network. I plan to use a multimodal, multi-scale and transversal (human and monkey) approach in experiments manipulating visual processing, attention and memory to test core predictions of my framework. The theoretical approach and the methodological development used in my project will provide the basis for future fundamental and clinical research.

Rapidly progressive glomerulonephritis (RPGN) is a syndrome of the kidney that is characterized by a rapid loss of renal function, with severe damage of glomeruli, the filtering units of the kidney through glomerular crescent formation (crescentshaped scars) seen on kidney biopsies. If left untreated, it rapidly progresses into acute renal failure and death within months. Regardless of the underlying cause, RPGN involves severe injury to the kidneys' glomeruli, with many of the glomeruli containing characteristic glomerular crescents. Currently RPGN is treated with broad-spectrum immunosuppression causing remission of the immune injury achieved in the majority of patients. Nevertheless, risk of end- stage renal failure at 5 years is still near 30 %, with a number of patients developing chronic kidney disease (CKD). Moreover, such treatments are associated with significant morbidity due to infections and malignancy. ERC-supported efforts in our lab have unravelled local mediators and transcription factors that critically control the tolerance of intrinsic glomerular cells to inflammatory insult. My team has shown that the PPARγ (peroxisome proliferatoractivated receptors gamma) pathway is instrumental in the protection of the inflammatory response during immunecomplex mediated RPGN, in large part through protection of kidney cells, named podocytes. We now plan to move forward to transform this finding from our TARGET-GLOMDIS ERC grant into a clinically effective innovative therapy. We expect to bring original therapeutic effect by preventing podocytes death and dysfunction in addition to promoting anti-inflammatory actions. The STOPIG project represents a unique opportunity to provide proof-of-concept for a new and cost-effective therapy for patients with RPGN based on stimulation of PPARγ with repurposed pioglitazone.

Regeneration of bone defects remains a critical challenge in orthopaedics. Mesenchymal stromal cells (MSC) with biomaterials show huge promise for bone regeneration. However, MSC die shortly after implantation and act as mediators, by secretion of paracrine factors (PF), rather than effectors of bone formation. Importantly, it seems that delivery of cells themselves may not be required for therapeutic benefit. When MSC are cultured in vitro they release PF into their conditioned media (MSC-CM) including cytokines and extracellular vesicles. The goal of this project is to prepare novel biomaterials which are loaded with MSC-CM for in situ bone tissue engineering. PF secreted into MSC-CM during normoxia, hypoxia, and cell death will be measured. Biomaterials (biphasic calcium phosphate ceramics) will be functionalized with MSC-CM by using the polyelectrolyte multi-layering (PEM) method. The biocompatibility, release kinetics, and potential of MSC-CM loaded biomaterials for bone regeneration will be tested in vitro on cells involved in bone formation (MSC, monocytes, osteoclasts, macrophages, and endothelial cells) and in vivo by implanting the biomaterials in subcutis sites and segmented femoral defects in nude mice. Importantly, the delivery of MSC-CM can overcome the donor-dependent variability in bone formation associated with MSC cell therapy and permits a more straightforward transfer of this therapy to clinical treatment. Since MSC-CM is devoid of cells and doesn’t carry patient rejection risk, autologous MSC are not required. Therefore, selected MSC that successfully induce bone formation can be used to collect potent MSC-CM which can be loaded onto biomaterials for therapeutic use in countless patients. An ‘off-the-shelf’ product that could harness the benefits of MSC therapy but circumvent the costly and time consuming multi-step procedures involved with MSC implantation would be of immense interest to the bone regeneration field.

Proteins hosting regions highly enriched in one or few amino acids, the so-called Low-Complexity Regions (LCR), are very common in eukaryotes and play crucial roles in biology. Homorepeats, a subfamily of LCR that present stretches of the same amino acid, perform very specialized functions facilitated by the localized enrichment of the same physicochemical property. In contrast, numerous severe pathologies have been associated to abnormally long repetitions. Despite the relevance of homorepeats, their high-resolution characterization by traditional structural biology techniques is hampered by the degeneracy of the amino acid environments and their intrinsic flexibility. In chemREPEAT, I will develop strategies to incorporate isotopically labelled and unnatural amino acids at specific positions within homorepeats that will overcome present limitations. These labelled positions will be unique probes to investigate for first time the structure and dynamics of homorepeats at atomic level using complementary biophysical techniques. Computational tools will be specifically developed to derive three-dimensional conformational ensembles of homorepeats by synergistically integrating experimental data. chemREPEAT strategies will be developed on huntingtin (Htt), the prototype of repetitive protein. Htt hosts a glutamine tract that is linked with Huntington’s disease (HD), a deadly neuropathology appearing in individuals with more than 35 consecutive Glutamine residues that represent a pathological threshold. The application of the developed approaches to several Htt constructions with different number of Glutamines will reveal the structural bases of the pathological threshold in HD and the role played by the regions flanking the Glutamine tract. The strategies designed in chemREPEAT will expand present frontiers of structural biology to unveil the structure/function relationships for LCRs. This capacity will pave the way for a rational intervention in associated diseases.

The metabolic syndrome (MetS) represents one of the major public health challenges worldwide. It reflects a combination of medical disorders that, when occurring together, increase the risk of developing diabetes and cardiovascular disease. The prevalence in the USA is estimated at 30% of the population and the European community follows this trajectory. It is now recognized that the state of chronic low-grade inflammation may favor the onset and progression of the MetS. While the notion of metabolic flexibility in hematopoietic cells has recently emerged in several inflammatory diseases, the origin of this immunometabolic alteration in the MetS remains elusive. There is a growing appreciation that the apportioning of nutrients into different metabolic pathways can support or direct functional immune and hematopoietic changes. Glutamine is the most abundant amino acid in the plasma and an important energy source through glutaminolysis. Despite its potential proliferative and/or immunosuppressive function and the strong association between high glutamine-to-glutamate ratio with cardiometabolic traits, the underlying mechanisms are poorly understood. Thus, there is a considerable therapeutic interest in better understanding the mechanisms linking glutamine to cardiometabolic risks and in particular cardiometabolic inflammation. In PROGLUTASIS, we will investigate the metabolic and immune regulation of glutamine homeostasis in the metabolic syndrome. We will validate the contribution of glutaminolysis in cardiometabolic inflammation, including obesity, diabetes and atherosclerosis through its role on hematopoiesis and macrophage dynamics. Given the ubiquitous association between glutamine and chronic metabolic stress, we expect that identifying the underlying molecular mechanism will offer novel therapeutic perspective on how to intervene in this pathway. This will ultimately allow for tailored strategies aimed at dampening cardiometabolic inflammation in the MetS.