Fig. 2

Transcriptional and translational regulation of ECs by SNs. a Gene expression analysis of angiogenic markers expressed by endothelial cells cultivated in the microfluidic devices in presence (grey bars) or absence (white bars) of sensory neurons in the central compartment. After 4 and 7 days of culture, cells were harvested, RNA was extracted and RT-qPCR was performed. Gene expression of Angpt1, VegfA and Col4 is upregulated in ECs when co-cultivated with sensory neurons after 7 days of culture. The graphs represent mean values ± SD (n = 4 independent experiments, unpaired t test, ** p < 0.01, *** p < 0.001). b Mmp2 gene expression is upregulated at both time points in presence of sensory neurons (n = 4 independent experiments, unpaired t test, * p < 0.05, ** p < 0.01). Concentration of MMP2 and MMP9 was measured in ECs’ supernatants cultivated with (grey bars) or without (white bars) sensory neurons. At both time points, MMP2/MMP9 concentration is increased in ECs when they are co-cultivated in presence of SNs (n = 5 microfluidic devices, unpaired t test, *** p < 0.001). Representative picture of enzymatic activity of matrix metalloproteinases measured by zymography. The band intensity was quantified using ImageJ software. In presence of sensory neurons, ECs show an increase of MMP2/MMP9 enzymatic activity at day 4 and day 7 (pool of n = 6 microfluidic devices)