Cysteine Peptidase Cathepsin X as a Therapeutic Target for Simultaneous TLR3/4-mediated Microglia Activation

Microglia are resident macrophages in the central nervous system that are involved in immune responses driven by Toll-like receptors (TLRs). Microglia-mediated inflammation can lead to central nervous system disorders, and more than one TLR might be involved in these pathological processes. The cysteine peptidase cathepsin X has been recognized as a pathogenic factor for inflammation-induced neurodegeneration. Here, we hypothesized that simultaneous TLR3 and TLR4 activation induces synergized microglia responses and that these phenotype changes affect cathepsin X expression and activity. Murine microglia BV2 cells and primary murine microglia were exposed to the TLR3 ligand polyinosinic-polycytidylic acid (poly(I:C)) and the TLR4 ligand lipopolysaccharide (LPS), individually and simultaneously. TLR3 and TLR4 co-activation resulted in increased inflammatory responses compared to individual TLR activation, where poly(I:C) and LPS induced distinct patterns of proinflammatory factors together with different patterns of cathepsin X expression and activity. TLR co-activation decreased intracellular cathepsin X activity and increased cathepsin X localization at the plasma membrane with concomitant increased extracellular cathepsin X protein levels and activity. Inhibition of cathepsin X in BV2 cells by AMS36, cathepsin X inhibitor, significantly reduced the poly(I:C)- and LPS-induced production of proinflammatory cytokines as well as apoptosis. Additionally, inhibiting the TLR3 and TLR4 common signaling pathway, PI3K, with LY294002 reduced the inflammatory responses of the poly(I:C)- and LPS-activated microglia and recovered cathepsin X activity. We here provide evidence that microglial cathepsin X strengthens microglia activation and leads to subsequent inflammation-induced neurodegeneration. As such, cathepsin X represents a therapeutic target for treating neurodegenerative diseases related to excess inflammation

Making Green Real – How to Promote Greenery in Real Estate Development

Climate change and rising temperatures particularly affect the built environment and intensify the Urban Heat Island (UHI) effect in cities. Nature-based solutions can have a balancing function and reduce overheating. However, greenery still receives too little attention in architecture and is added as an additional element at the end of the planning phase or even after the building has been constructed. For a climate resilient urban development in the future, in addition to a change in processes, a change in real estate development and in the project management is necessary. At least, three preconditions must be met for this to happen: • Sound knowledge base: Many studies already exist proving the positive effects of nature-based solutions for densely built cities. However, the knowledge transfer to real estate companies is still insufficient as they require precise and site-specific information showing effectiveness of greenery on microclimate, building envelope and indoor temperature. At best, analyses apply a system view and consider interrelations with water and energy. • Greenery-friendly planning framework: Real estate development takes place in compliance with local planning standards and procedures. Planning strategies and regulations, standards, urban development contracts and funding programmes strongly influence urban design and development and hereby have great potential to promote greening. • Integrated mindset: In architecture and real estate development, it is still not standard to include greenery and nature-based solutions in design, planning and construction. Building optimization also includes greening. Thus, it needs an integrated mindset regarding greenery as natural part of architecture. This requires more awareness and knowledge about climate change and the benefits of nature-based solutions on quality of life and value of real estates in the long run. The paper summarizes the experience of an interdisciplinary cooperation in the research project GreenDeal4Real and addresses all three aspects in detail. Analyses of the planning framework in Vienna and impacts of greening measures on the microclimate are described and general conclusions for more green in real estate development are drawn