Consequences of invasion on the functional organization of multicellular tissues (Destaing, Thibert, Planus, Faurobert))
This axis is developed through 3 projects:
• Physio-pathological invasions in multicellular models (Destaing, Planus, Thibert)
We compare tissue invasion by immune cells (e.g., macrophages, lymphocytes) and cancer cells to understand why immune cell invasion preserves tissue integrity, while cancer cell invasion disrupts it. In collaboration with physicists from Liphy (C. Verdier, P. Recho), we link the interactions between invasive cells, ECM and tissular cells in spheroids to the underlying biophysical mechanisms. Using optogenetics, we selectively activate SRC family kinases (SFKs)—key regulators of invadosomes—to induce macrophage migration or invasion. By combining optogenetics, genomics, and live imaging (Kerjouan et al., 2021), we control invadosome properties in both immune and cancer cells within tissue-like environments (e.g., epithelium, endothelium), assessing the impact on invasive and resident cells. At the subcellular level, we investigate SFK functions in invadosomes and how metabolic pathways (AMPK-mTOR balance) sustain invasion in multicellular contexts.
• Investigating megakaryocyte invasion of blood vessel for platelet formation (Destaing-Planus)
Megakaryocytes produce blood platelets by extending proplatelet arms into the bloodstream through a unique invasive process that maintains bone marrow integrity. Our collaborators linked this function to a subcellular structure, the podoPZ—highly homologous to invadosomes (Eckly et al., J Thromb Haemost, 2020). We developed the first in vitro pipeline to recreate podoPZ and invasive proplatelets, enabling us to study their organization, dynamics, mechanical properties, and uncover new molecular determinants via transcriptomics and proteomics.
• Roles of mechanotransduction during pathological endothelial collective invasion (Faurobert)
Cerebral Cavernous Malformations (CCMs) are mosaic vascular lesions that form exclusively in low-flow cerebral capillaries. Our research highlighted the role of cell mechanics in the collective invasion by mutant endothelial cells (Coll. Van Oosterwyck Leuven, Belgium). Recently, we identified a mechanotransduction pathway that drives the invasive phenotype of CCM mutant ECs. Key unanswered questions include the sensitivity to flow of this collective invasion and the role of the mechanotransduction pathway in co-occurring cell fate reprogramming.
Revisited dynamics of intracellular signaling during invasion (Destaing-Faurobert)
We explore the dynamics of intracellular signaling, focusing on post-translational modifications (e.g., phosphorylation) that regulate invasive structures like focal adhesions, cell-cell contacts, and invadosomes. We target key drivers of migration and invasion: SRC family kinases (SFKs) and RhoA-associated kinases (ROCK1/ROCK2). Moving beyond the traditional linear view of signaling pathways, we adopt a dynamic signaling network approach. We control signaling events using optogenetics and perform proteomics and quantitative interactomics to measure hundreds of protein affinities (nHold-up) (coll. Gogl, Nice). This allows the design of new signaling networks using oriented interaction graphs (Coll. Brun, Marseille) and the subsequent modeling of cell behavior using 4D in silico simulations (Coll. Calzone).
Translational & methodological research on invasion (Destaing-Faurobert-Thibert)
• Detecting and renormalizing CCM invasion (Faurobert)
Having identified mechanotransduction events occurring during CCM initiation and progression represents an innovative entry point in the search for therapies and predictive biomarkers that INVADE is currently developing.
• Synthetic control of physiological invasion for anti-tumoral strategy (Destaing)
Regulating macrophage activities in the tumour microenvironment is a major challenge as macrophages can have either anti- (M1-type) or pro-tumoral (M2-type) activities. We propose a dynamic approach using our optogenetic activation of SFKs to restore cytotoxic and anti-tumour functions of macrophage, regardless of their differentiation state.
• Developing optical methods and analyses for tracking multidimensional invasions (Destaing, Thibert)
INVADE develops photomanipulation and 3D imaging of metabolic and structural invasion processes, leveraging collaborations with the MicroCell-IAB platform and LIPHY (Grenoble). Building on expertise in 2-photon NAD(P)H autofluorescence imaging (Bosc et al., Sci Adv accepted), we develop metabolic imaging (ATP, ROS, pH) using a new spinning disk-TIRF microscope with a FastFLIM module (Inscoper) optimized for TIRF. For large 3D samples, a multi-scale 3D imaging pipeline—combining lightsheet, confocal microscopy, and adaptive optics—is being developed to analyze tissues from organ to subcellular levels. Additionally, we integrate AI-based image analysis at MicroCell to quantify invasion dynamics and implement AI-driven smart microscopy for improved detection of rare events.