Cardiovascular prosthetic bypass grafts do not endothelialize spontaneously in humans, and so they pose a thrombotic risk. Seeding with cells improves thei r performance, particularly in small-caliber applications. Knitted tubular polyethylene- terephthalate (PET) vascular pros theses (6 mm) with commercial type I collagen (PET/Co) were modified in the lumen by the adsorption of laminin (LM), by coating with a fibrin network (Fb) or a combination of Fb and fibronectin (Fb/FN). Primary human saphenous vein endothelial cells were seeded (1.50 × 10 5 /cm 2 ), cultured for 72 h and exposed to laminar shear stress 15 dyn/cm 2 for 40 and 120 min. The control static grafts were excluded from shearing. The cell adherence after 4 h on PET/Co, PET/Co +LM, PET/Co +Fb and PET/Co +Fb/ FN was 22 %, 30 %, 19 % and 27 % of seeding, respectively. Comp ared to the static grafts, the cell density on PET/Co and PET/Co +LM dropped to 61 % and 50 %, respectively, after 120 min of flow. The cells on PET/Co +Fb and PET/Co +Fb/FN did not show any detachment during 2 h of shear stress. Pre-coating the clinically-used PET/Co vascular prosthesis with LM or Fb/FN adhesive protein assemblies promotes the adherence of endothelium. Cell retention under flow is improved particularly on fibrin-containing (Fb and Fb/FN) surfaces., J. Chlupáč ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Proliferation and migration of retinal endothelial cells (RECs) contribute to the development of diabetic retinopathy. PLAG1 (pleomorphic adenoma gene 1) functions as a zinc-finger transcription factor to participate in the development of lipoblastomas or pleomorphic adenomas of the salivary glands through regulation of cell proliferation and migration. The role of PLAG1 in diabetic retinopathy was investigated in this study. Firstly, RECs were induced under high glucose conditions, which caused reduction in viability and induction of apoptosis in the RECs. Indeed, PLAG1 was elevated in high glucosetreated RECs. Functional assays showed that silence of PLAG1 increased viability and suppressed apoptosis in high glucose-induced RECs, accompanied with up-regulation of Bcl-2 and down-regulation of Bax and cleaved caspase-3. Moreover, migration of RECs was promoted by high glucose conditions, while repressed by knockdown of PLAG1. High glucose also triggered angiogenesis of RECs through up-regulation of vascular endothelial growth factor (VEGF). However, interference of PLAG1 reduced VEGF expression to retard the angiogenesis. Silence of PLAG1 also attenuated high glucose-induced up-regulation of Wnt3a, β-catenin and c-Myc in RECs. Moreover, silence of PLAG1 ameliorated histopathological changes in the retina of STZ-induced diabetic rats through down-regulation of β-catenin. In conclusion, knockdown of PLAG1 suppressed high glucose-induced angiogenesis and migration of RECs, and attenuated diabetic retinopathy by inactivation of Wnt/ β-catenin signalling.
Micropatterned surfaces have been used as a tool for controlling the extent and strength of cell adhesion, the direction of cell growth and the spatial distribution of cells. In this study, chemically micropattern ed surfaces were prepared by successive plasma polymerization of acrylic acid (AA) and 1,7-octadiene (OD) through a mask. Rat vascular smooth muscle cells (VSMC), bovine endothelial cells (EC), porcine mesenchymal stem cells (MSC) or human skeletal muscle cells (HSKMC) were seeded on these surfaces in densities from 9,320 cells/cm2 to 31,060 cells/cm2. All cell types adhered and grew preferentially on the strip-like AA domains. Between day 1 and 7 after seeding, the percentage of cells on AA domains ranged from 84.5 to 63.3 % for VSMC, 85.3 to 73.5 % for E, 98.0 to 90.0 % for MSC, and 93.6 to 55.0 % for HSKMC. The enzyme-linked immunosorbent assay (ELISA) revealed that the concentration of alpha-actin per mg of protein was significantly higher in VSMC on AA. Similarly, immunofluorescence staining of von Willebrand factor showed more apparent Weibel-Palade bodies in EC on AA domains. MSC growing on AA had better developed beta-actin cytoskeleton, although they were less stained for hyaluronan receptor (CD44). In accordance with this, MSC on AA contained a higher concentration of beta-actin, although the concentration of CD44 was lower. HSKMC growing on AA had a better developed alpha-actin cytoskeleton. These results based on four cell types suggest that plasma polymerization is a suitable method for producing spatially defined patterned surfaces for controlled cell adhesion, proliferation and maturation., E. Filová ... [et al.]., and Obsahuje seznam literatury
Effects of low-frequency electromagnetic fields (LF EMF) on the
activation of different tissue recovery processes have not yet
been fully understood. The detailed quantification of LF EMF
effects on the angiogenesis were analysed in our experiments by
using cultured human and mouse endothelial cells. Two types of
fields were used in the tests as follows: the LF EMF with
rectangular pulses, 340-microsecond mode at a frequency of
72 Hz and peak intensity 4 mT, and the LF EMF with sinusoidal
alternating waveform 5 000 Hz, amplitude-modulated by means
of a special interference spectrum mode set to a frequency linear
sweep from 1 to 100 Hz for 6 s and from 100 Hz to 1 Hz return
also for 6 s, swing period of 12 second. Basic parameters of
cultured cells measured after the LF EMF stimulus were viability
and proliferation acceleration. Both types of endothelial cells
(mouse and human ones) displayed significant changes in the
proliferation after the application of the LF EMF under conditions
of a rectangular pulse mode. Based on the results, another test
of the stimulation on a more complex endothelial-fibroblast
coculture model will be the future step of the investigation.