June 14th 2019

UNIVERSITE LYON 1,  ICBMS UMR 5246 CNRS, BATIMENT LEDERER

Matrix vesicles are a specific class of extracellular vesicles with diameter between 100 to 300 nm. They are blebbed, under physiological conditions, from hypertrophic chondrocytes during endochondral ossification, by osteoblasts during intramembranous ossification and by odontoblasts during dentin formation. Matrix vesicles, by accumulating calcium and phosphate, can initiate the first step of nucleation of crystals leading to apatite. They are enriched in alkaline phosphatase, the enzyme responsible for the hydrolysis of pyrophosphate, an inhibitor of apatite formation. Once apatites are formed, they are released from matrix vesicles to the extracellular matrix in the vicinity of the collagen fibers due to strong association of matrix vesicles with collagen. Other non-skeletal cells, such as smooth muscle cells, are able to release matrix vesicles, leading to vascular calcification. The symposium is focused on answering questions such as : How matrix vesicles are released by mineralization competent cells?  How calcium and phosphate accumulate in matrix vesicles? What are the biochemical and biophysical properties of matrix vesicles? What are the functions of matrix vesicles? To what extend do they affect ectopic calcification? What clinical applications could be derived from knowledge of the functions of matrix vesicles? How proteoliposomes mimicking matrix vesicles can be used in nanomedicine?

TARGET AUDIENCE INCLUDES GRADUATE STUDENTS, Ph D STUDENTS, POST-DOCS OR EXPERIENCED SCIENTISTS

• Matrix vesicles formed during physiological and pathological conditions
• Functions of matrix vesicles
• Biogenesis of matrix vesicles
• Methods to analyze the morphology and biochemical and biophysical properties of matrix vesicles
• Determination of calcium and phosphorus inside matrix vesicles
• Lipidomics and phospholipase activity in matrix vesicles
• Proteoliposomes mimicking matrix vesicles

TRANSMISSION ELECTRON MICROSCOPY OF MATRIX VESICLES AND COLLAGEN FIBERS AND X-RAY ELEMENTAL MAPS OF CALCIUM AND PHOSPHORUS IN MATRIX VESICLES