Fig. 6

Schematic illustration of the regulatory role of microRNAs (miRNAs) in vascular wall cells (endothelial cells (ECs) and vascular smooth muscle cells (VSMCs)) and their secretion into the bloodstream. Vascularly enriched miRNAs regulate cellular responses to various factors both in normal and pathological conditions by acting on various receptors and signaling pathways: miR-15a - decreases blood-brain barrier (BBB) disruption and protection of cerebral ECs apoptosis; miR-17-92, miR-210 and miR-132 - angiogenesis; miR-23a - inhibition of ECs growth; miR-26a - increase VSMCs proliferation and control VSMC phenotype shifting; miR -143/145 and miR-146a - activation of VSMCs proliferation and neointimal hyperplasia; miR-24 - inhibition of erythropoiesis and control VSMC phenotype shifting; miR-221/miR-222 - pro-proliferative effect on ECs and angiogenesis. In addition, it is known from recent sources that these vascular-enriched miRNAs can occur in the bloodstream and may be biomarkers of early damage to the vascular wall. Note: Bax, Bcl-2-associated X protein; Bcl-2, B-cell lymphoma 2; CTGF, connective tissue growth factor; EGF, epidermal growth factor; Elk-1, ETS domain-containing protein 1; ERK, extracellular signal-regulated kinase; FGF, fibroblast growth factor; GAX, homeobox protein; KLF4, krüppel-like factor 4; KLF5; krüppel-like factor 5; MEK, mitogen-activated protein kinase kinase; PI3K, Phosphatidyl-inositol 3-kinase; p120RasGAP, p21, cyclin-dependent kinase inhibitor 1; Rb, Retinoblastoma; p, Hpophosphorylated; Raf, rapidly growing fibrosarcoma; Ras, rat sarcoma; RhoA, Ras homolog gene family member A; Smurf1, Smad ubiquitin-regulatory factor 1; SRF, serum response factor; TGF-b, transforming growth factor beta; Trb-3, Tribbles-like protein-3; TSR1, thrombospondin-1; VEGF, vascular endothelial growth factor; ZEB2, zinc finger Ebox- binding homeobox 2.