Diabetes affects endothelial cell function and alters fibrin clot formation in a microvascular flow model: A pilot study

Figures

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  Figure 1.. The microvascular flow model. (a) Exemplary picture of a PDMS straight channel device with three microchannels filled with red dye to visualise the channel size. For size comparison, the device is shown next to a Swiss 1 Franc coin with a diameter of 2.32 cm. [Figure 1(a), from Jenny et al.26 is subject to the creative commons licence (www.creativecommons.org) and has not been changed.] (b) Two microchannels coated with a human microvascular endothelial cell monolayer, 48 h after the channels were seeded. Scale bar = 100 µm. (c) Experimental setup of a straight channel device being perfused with diabetic whole blood while observing the blood flow by laser scanning confocal microscopy.

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  Figure 2.. Exemplary images from one clot formation experiment in the microvascular flow model. The images illustrate how clot formation was detected in the microvascular flow model and how the quantitative evaluation was performed. Microchannels were coated in duplicates with (a) non-diabetic or (b) type 2 diabetic human microvascular endothelial cells. Microscopic images were taken at 10× magnification, 25.5 min after the blood was recalcified. Red stain: endothelial cells; green stain: deposited fibrin. Scale bar = 100 µm. (c) Corresponding fluorescence intensity curve over time, with each point being the mean of duplicates.

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  Figure 3.. Expression of diabetic marker genes in diabetic and non-diabetic human microvascular endothelial cells. Individual gene expression in the cells from the donors with diabetes is shown relative to the expression in control cells from donor 1 without diabetes (depicted as black bars) and relative to donor 2 without diabetes (white bars). Error bars represent the standard deviation from two technical replicates. AGE receptor: advanced glycation end-product-specific receptor; FN1: fibronectin; PAI-1: plasminogen activator inhibitor-1; T1DM: type 1 diabetes mellitus; T2DM: type 2 diabetes mellitus.

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  Figure 4.. Schematic illustration of clot formation experiments in the diabetic microvascular flow model. This figure explains the complex study design but does not accurately reflect the results. Non-diabetic (green), type 1 diabetic (yellow) or type 2 diabetic (red) whole blood was used to perfuse parallel microchannels coated with non-diabetic (green), type 1 diabetic (yellow) or type 2 diabetic (red) primary human cardiac microvascular endothelial cells. Clot formation was recorded over time. The black star symbolises statistical significance.

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  Figure 5.. Comparison of clot formation between the pure non-diabetic, type 1 and type 2 diabetic models. Boxplots (representing median and interquartile range, with error bars showing the 10th and 90th percentile and black dots representing outliers) show the clot formation observed in non-diabetic cells perfused with non-diabetic blood, T1DM cells perfused with T1DM blood and T2DM cells perfused with T2DM blood.