Cardiovascular disease and mTOR signaling.

The cell signaling pathways of the mammalian target of rapamycin (mTOR) are broad in nature but are tightly integrated through the protein complexes of mTORC1 and mTORC2. Although both complexes share some similar subcomponents, mTORC1 is primarily associated with the regulatory protein Raptor, whereas mTORC2 relies on Rictor. Pathways of mTOR that partner with Wnt as well as growth factor signaling are vital for endothelial and cardiomyocyte growth. In mature differentiated endothelial cells and cardiac cells, mTOR activation regulates both apoptotic and autophagic pathways during oxidative stress that can be dependent on the activation of protein kinase B. These protective pathways of mTOR can promote angiogenesis and limit acute cell death to foster cardiac repair and tissue regeneration. However, under some conditions, blockade of mTOR pathways may be necessary to limit vasculopathy and promote microcirculatory flow. Future work that further elucidates the vital regulatory pathways of mTOR can offer new therapeutic insights for the treatment of cardiovascular diseases.