Vascular smooth muscle cell contractile proteins as universal markers of vessels of microcirculatory bed

Highlights . The use of vascular smooth muscle cell markers, e.g. myosin heavy chain (SM-MHC) and alpha actin (α-SMA) for immunodetection adventitial perivascular microvessels (vasa vasorum) is preferrable over endothelial markers (CD31 VE-cadherin) as it allows to define geometry regardless sectioning artifacts provides ideal signal-to-noise ratio. Aside from elastic laminae which discriminate arterioles venules capillaries, we were unable confirm any specific arterial, venous, capillary differentiation, although KLF2 PROX1 transcription factors indicated venous specification HEY1 suggested identity in rat aortas. Aim To develop an optimal approach detection evaluate the techniques differential immunostaining arterioles, venules, capillaries human saphenous veins Methods Saphenous excised during coronary artery bypass graft surgery used study. Serial cryosections analyzed by means haematoxylin eosin Russell-Movat’s pentachrome stainings immunofluorescent staining VE-cadherin), (SM-MHC α-SMA), mechanosensitive (KLF2 KLF4), arterial (HES1, HEY1, ERG), (NR2F2, NRP2), lymphatic lineage (PROX1, LYVE1, VEGFR3). Samples visualized light confocal microscopy. Results In comparison with α-SMA) permitted objective evaluation maximized ratio irrespective marker, microvessel or antibody used. Autofluorescence histological pattern membranes at allowed capillaries. Albeit aortas found cells PROX1) (HEY1), these findings have not been confirmed veins. We find among vein vasa vasorum despite extensive screening multiple markers. Conclusion Immunodetection (e.g., should be performed using rather than VE-cadherin). Lack discern different lineages suggests option machine learning neural networks analyse including vasorum.