Subventions et des contributions :

Subvention ou bourse octroyée s'appliquant à plus d'un exercice financier. (2017-2018 à 2022-2023)

Introduction: Scientists in the field of experimental vascular biology are constantly confronting two major challenges: 1) integration of multiple mechanical forces (e.g. shear stress, cyclic strain, and hydrostatic pressure) into the experimental system(s) that employ in vitro cell cultures (e.g. vascular endothelial cells) and 2) the fact that most cell cultures are grown at the ambient O 2 (i.e. 21% O 2 ) as opposed to physiological levels of 5% O 2 seen in most organs/tissues.
In regard to the former, studying the effects/mechanisms of hydrostatic pressure on EC responses have received much less attention relative to studies of shear stress and cyclic strain. Hydrostatic pressure (e.g. increase in hydrostatic pressure), that once was considered a purely “mechanical component” and hence, a relatively benign pathophysiological condition, recently has been recognized as a potential stimulus inducing mechanosignaling. Limited research findings (including our own) indicate that increase in hydrostatic pressure induces complex and highly sensitive cellular responses, therefore, may play a critical role in regulation of the microcirculation. The mechanistic aspects of hydrostatic pressure-induced changes in vascular endothelial cell physiological/pathophysiological responses remain poorly understood.
The other major challenge for cell biologists is the conditions at which most of cells are grown and used in the in vitro experiments. The common practice is to culture the cells at the ambient O 2 (i.e. 21% O 2 ). However, most of the body’s cells are exposed to approximately 5% O 2 , thus making commonly accepted conditions of cell growth and experimentation (e.g. room air; 21% O 2 ) severely “hyperoxic” and unphysiological.
Research Approach: The main goal of this research program is to investigate vascular endothelial cell responses (e.g. molecular signaling and functional consequences) to hydrostatic pressure and to further develop a new experimental model allowing investigating the effects/mechanisms of hydrostatic pressure in vitro under physiological O 2 levels.
This study will use primary human vascular endothelial cell cultures representing various vascular beds (e.g. microvascular EC derived from brain, lung, skin) which will be cultured and used in the experiments under conditions of 5% O 2 and hydrostatic pressure (0-30 mmHg) employing state-of-the-art microperfusion and cell co-culture approaches. Various aspects of cell function/dysfunction (e.g. production of oxidants, cytokines, rearrangement of cytoskeleton, changes in permeability and pro-adhesive phenotype, etc.) will be assessed.
Expectations: This research program will allow to develop a new experimental model in vitro closely mimicking physiological/pathophysiological conditions in vivo . In addition, it will provide excellent grounds for training of at least three graduate (MSc) students.