The 70 kDa heat shock protein (HSP70) is a versatile molecular chaperone that plays a role in protein folding, translocation of proteins to organelles, protein degradation by the ubiquitin proteasome system and also by autophagy. The HSP70 plays a role in endothelial cell migration VEGF2 induced and is important for tube formation showing its role in angiogenesis. Most of these studies focus on the function of extracellular HSP70. Although its exact intracellular function in this context is unknown as its interaction with two proteins such as nucleolin and CLEC14a cannot be responsible for the effect of HSP70 on angiogenesis not associated with disease. Recently our group discovered (manuscript in Major Revision in Cell Stress and Chaperones) that physiological shear stress increases the expression of HSP70 while the pathological one reduces its expression in vitro and ex vivo in the aorta. We believe that proteostasis mediated by this chaperone is fundamental for the maintenance of vascular physiology. One pathway of proteostasis activated in endothelial cells is autophagy.In the present project, the objective is to assess the effects of HSP70 silencing on protein synthesis and on the degradation of client proteins in endothelial cells submitted to physiological and pathological stress shear. Thus, the activity of the proteasome and autophagic machinery associated with chaperone-mediated degradation will be studied. Another hypothesis that will be investigated is that the loss of function of HSP70 leads to the aggregation of some potential client proteins. The comparative analysis of the two shear stress types may provide us subsidies for understanding the major function of HSP70 in this context. Moreover, we will evaluate the effects of the HSP70-YK5 allosteric inhibitor that has an anti-tumor effect developed by Prof. Gabriela Chiosis-researcher associated with the project. The characterization of the effects of YK5 is essential since HSP70 has been strongly considered as a therapeutic target for diseases such as cancer and neurodegeneratives, although its effects on the vasculature are unknown.
News published in Agência FAPESP Newsletter about the scholarship: