Microglia are the brain resident immune cells that maintain brain homeostasis by responding to cytokines and eliminating substances by phagocytosis. Microglial activation and phagocytotic clearance of aggregated amyloid ß (Aß) and tau aggregates limits Alzheimer’s disease (AD) pathology. There is an urgent need to elucidate the mechanisms that promote these actions and to develop novel approaches to control AD pathology. We recently discovered that Sulf2, an extracellular heparan sulfate (HS) sulfatase, selectively suppresses microglial response to interleukin 4, a cytokine that restricts microglia activation. Furthermore, our preliminary result showed that Sulf2 facilitated microglial phagocytotic clearance of Aß deposits ex vivo. The aims of the proposed project are: i) to clarify the molecular mechanism underlying Sulf2 effects on these microglia functions and ii) to investigate whether HS remodeling by Sulf2 could reduce Aß load and tau aggregates in AD brain in vivo by facilitating sustained and controlled microglial phagocytosis activity over time. The HS compositions and structure of HS S-domains present in Sulf2-transduced microglial cell line and primary mouse microglia; in the brains of microglia-specific Sulf2 transgenic/J20 hAPP-Tg and P301S tau-Tg AD model mice; in AD patient brains, will be determined by state-of-the-art methods, including mass spectrometry-based methods and a protein nanopore oligosaccharide sequencing technique. RNA-seq transcriptome analysis will be also performed for these microglial cells and AD model mouse brains. We will evaluate AD pathogenesis in vivo in these Sulf2-transgenic AD model mice. The partners’ expertise in glycoscience, neurology, and structural biology strengthens the accomplishment of the proposed project. As a whole, our ultimate goal is to develop a novel strategy for AD treatment with the idea of contributing to better health and well-being as well as social and economic welfare.

Given the sixth assessment report of the Intergovernmental Panel on Climate Change (IPCC), the announced depletion of fresh water, the indiscriminate use of toxic chemicals and the impact of all these drifts on the future of our planet and on biodiversity, new production methods of biosourced molecules, less energy-consuming, not generating CO2 and less demanding in fresh water must be investigated to ensure a credible and sustainable transition. In line with these concepts, the EPPIC project proposes to investigate 3 different routes for polymer production starting from sugar by-products or CO2 in sea water. Enzymatic routes with multiples natural or evolved enzymes, cell-based processes involving engineered microorganisms and hybrid processes combining cell-free and cell-based systems will be developed. These innovative production routes will be evaluated using an eco-design and life cycle assessment approach to identify the most promising production routes and to assess their energy and environmental performances.

Immunohistochemistry (IHC) combined with fluorescence microscopy provides an important and widely used tool for biologists and pathologists to image multiple biomarkers in tissue specimens. However, multiplex IHC using standard fluorescence microscopy is generally limited to 3-5 different biomarkers, with hyperspectral or multispectral methods limited to 8. However, The tag-mass technology linked to mass spectrometry has already demonstrated, via the use of a probe associated with a laser-wavelength photocleavable link and a peptide reporter, the ability to perform multiplex analyses allowing the simultaneous detection of proteins, transcripts and glycans (MALDI-IHC). This concept has now been extended to up to 100-plex.via Miralys probes. However, besides, the ability to screen several markers in one assay, it is also important to develop a new MALDI-IHC technology with a highly specific, sensitive, fast, flexible, and highly multiplexed, and with a limiting production cost. The goal of Click&Detect is to develop a new generation of assays based on modified aptamer probes for mass spectrometry (MS) on tissues detection. The project will be organised around 4 specific objectives which will be i) the development of modified aptamer probes using bioorthogonal chemistry to allow the addition of the reporter (Tag) for MS detection by click chemistry, ii) the validation of the obtained Aptamer tags and the amplification of the signal iii), the development of the tissue assay using these modified aptamers and iv) the validation on a pathology By using stable isotopically labelled tags, it will be possible to achieve high multiplexing while maintaining flexibility and without the need to purchase a specific instrument to perform the test.