Fig. 2

SPARC expression positively correlates with a marker of proliferation Ki-67. a Representative immunocytochemistry images of subconfluent hCMEC/D3 show greater SPARC expression and higher proportions of Ki-67-positive cell nuclei than confluent cultures. Images represent SPARC staining (red) alone (upper panel) or merged with Ki-67 staining (green) in the lower panel. Data represents one of two replicate experiments. Scale bar = 30 μm. b Percentage of cells positive for the proliferation marker Ki-67 in the subconfluent hCMEC/D3 is greater than that of the confluent cultures. Confluent hCMEC/D3 in two experiments had significantly (exp. A: P = 0.0143; exp. B: P = 0.0017) lower incidence of Ki-67-positive nuclei than the subconfluent cultures. Bars represent the average of results (20 images from triplicate subconfluent wells and 8 images from duplicate confluent wells) grown on collagen membranes ± standard deviation (SD). Mann-Whitney comparison test, **P < 0.001. c SPARC levels positively correlated with the percent of Ki-67-positive cell nuclei in subconfluent hCMEC/D3 cultures. Ki-67 staining is significantly different between groups classified according to increasing levels of SPARC staining from negligible to low through moderate and high combined (P < 0.0001). Bars represent the average of results from n = 20 images pooled from triplicate wells. Error bars indicate SEM. Data represents one of the two experiments with similar significant results. One-way ANOVA and Tukey’s multiple comparison test, **P < 0.001, ***P < 0.0001