Paracrine interaction mediated by extracellular vesicles between mesangial and endothelial cells in hypoxia and its contribution to fibrosis

Abstract

In chronic kidney disease, both tubulointerstitial and glomerular sclerosis is observed. While the role of hypoxia in tubulointerstitial fibrosis is much studied, the glomerular lesion is less evaluated. Endothelial cells interact with the mesangial cells in the glomerulus, these cells produce extracellular matrix. This interaction, especially in deleterious conditions such as hypoxia, can occur via extracellular vesicles. The objective of this work is to analyze the in vitro communication between endothelial and mesangial cells through extracellular vesicles under conditions of hypoxia and to evaluate the function of mesangial cells under these conditions, such as proliferation and synthesis of extracellular matrix proteins. Human endothelial cells (HUVEC) will undergo hypoxia (1% O2, 5% CO2) and normoxia (21% O2 and 5% CO2) for 48h. Exosomes (50 ¼g / ml) will be extracted for characterization and use in the treatment of endothelial cells for 48h. Our preliminary results showed that the exosomes extracted culture medium in normoxia, showed a fashion of 139 nm and a concentration of 9.5 1010 particles/ml, consistent with exosomes. Western blot analysis showed that exosomes express specific markers such as CD63 and CD81. Additionally, the lactate dosage in the culture medium showed that the cells in hypoxia produced more lactate than the cells in normoxia, consistent with the conditions of low O2 pressure. Further results are needed to evaluate the interaction between endothelial and mesangial cells through the exosomes.