Fig. 3: Extracts from wild lettuce relatives L. saligna and L. virosa reduce epithelial integrity and cell viability in the bioengineered intestinal tubule.
From: Bioengineered intestinal tubules as a tool to test intestinal biological efficacy of lettuce species
a Schematic of the phylogenetic tree for Lactuca species. L. sativa and wild progenitor belong to gene pool 1, while L. saligna and L. virosa are from pools 2 and 3, respectively. Representative photographs of 2.5–3-week-old plants of b L. sativa cv. Olof, c L. sativa cv. Salinas, d L. serriola US96UC23, e L. saligna CGN05271, f L. virosa CGN04683 used in the study. (G-L) Representative immunofluorescent images of nuclei (blue) and zonula occludens-1 (ZO-1, red) on intestinal tubule after exposure to medium (control) or extracts of L. sativa cv. Salinas and L. sativa cv. Olof, L. serriola, L. saligna, and L. virosa, respectively. m, n The intestinal epithelial barrier integrity is assessed via inulin-FITC permeability m and ZO-1 quantification n. Inulin-FITC permeability data are shown relative to the negative control, and ZO-1 quantification data are corrected for surface area and the number of nuclei. o Mitochondrial activity as a measure of cell viability after exposure to Lactuca extracts. Data are shown relative to medium control. p The number of nuclei corrected for the surface area as a measure of cell attachment. q Brush border enzyme activity of alkaline phosphatase, a common Caco-2 enterocyte differentiation marker. r–t Amounts of the secreted immune markers interleukin (IL)-6, IL-8, and nitric oxide (NO), respectively. White bars represent basal levels in the Lactuca extracts, whereas black bars visualize the concentration in the supernatant after 24 h of cellular exposure. Data are presented as mean ± SEM of n = 6 independent experiments. Data were corrected for outliers (1 outlier of 402 data points) and tested for significance using a t-test and one-way ANOVA. *p < 0.05, **p < 0.005, ***p < 0.001 and ****p < 0.0001. Scale bar is 50 µM.
