© Fabrice Chrétien, Shahragim Tajbakhsh, Jean-Marc Panaud
Cellule souche (en jaune) de muscle squelettique partiellement recouverte par la membrane basale, migrant sur une fibre musculaire (en bleu).

Human Histopathology and Animal Models


Within our research laboratory, we investigate cell interactions occurring in a homeostatic condition and during and after an injury at the tissue level in both central nervous system (CNS) and skeletal muscle. CNS is protected by the blood-brain barrier and has a resident inflammatory cell population (microglial cells); therefore this is a tissue of choice for studying acute injury, like sepsis. On the other hand, skeletal muscle shows a striking ability to regenerate efficiently and is easily accessible. We use this tissue as a paradigm for chronic lesions and regeneration. In both situations, we aim to characterize tissue compartments and cell interactions through in vivo and in vitro approaches. In the CNS, we study the early involvement of the neurovascular unit during sepsis. In the skeletal muscle, we explore the role of stem cells and stromal partner cells (endothelial cells, macrophages, fibroblasts) at homeostasia and during regeneration.

Our major findings during the last year are (i) that microglial cells are activated very early in the brain after a peripheral infection and during septic shock, (ii) that muscle stem cells show an extreme ability to survive hypoxic environment, keeping with the existence of an hypoxic niche for satellite cells.

Sans titre
Brain histological imaging during sepsis (green: microglia, red: vessels: purple astrocytes)


We have also Expertise activities in Human & Comparative Pathology. We are promoting the analysis of animal models by assisting and educating in their pathological evaluation and to develop diagnosis, research and education in human pathology. Through a Core facility in histopathology with four histo-technicians, we provide a technical support to other research laboratories. We master quality, flexible routine and innovative techniques, like low-melting point paraffin technique for immunohistochemistry of labile antigens, acrylic resin semi-thin sections, or large sections, on either animal or human samples. In this Centre of Expertise, four histopathologists coming from medical and veterinary education contribute to the choice of morphological approaches, the design of protocols, and perform the evaluation of microscopic slides. We were involved last year in more than 30 scientific collaborations mainly in the field of animal models of infectious diseases. The Centre also receives human cases for diagnosis and ancillary techniques, particularly in mycology and parasitology, and we have weekly interactions with the Centre National de Référence des Mycoses Invasives et Antifongiques (Head: Prof F. Dromer).


Program Projects





25-28 Rue du Docteur Roux
75015, Paris