Fig. 2

Histochemical analysis of fresh and conditioned UC. a.  Tissue section (4 μm) of hematoxylin and eosin-stained fresh UC tissue (left panel) was compared with conditioned UC tissue following a 14-day explant culture (middle panel) and with frozen conditioned UC tissue after thawing and reculture (right panel). b Expression of MSC markers in UC tissue pieces. mRNA from UC tissue pieces at different conditions (fresh UC, conditioned UC, and frozen conditioned UC after reculture) was analyzed by RT-PCR for transcripts of the MSC markers CD73, CD90, and CD105 with GAPDH expression as a control. c Proliferation of MSCs in fresh UC tissue pieces during conditioning. UC tissue pieces of similar size and weight (graph insert) prepared directly after delivery were labeled by lentiviral eGFP gene transduction. Thereafter, the UC tissues were incubated in MSC medium for up to 19 days and the GFP fluorescence intensity in the tissues was monitored at the time points indicated. Data represent the mean ± standard deviation (SD) (n = 6). Statistical analysis was performed by Student's t test between the fluorescence intensities of the unlabeled UC tissues (autofluorescence of the tissues = control) and after eGFP gene transduction (p <0.001). Moreover, statistical differences between the fluorescence intensities of day 1 and day 19 revealed a significance of p <0.05. d Proliferation of MSC in cryopreserved UC tissue pieces after reculture. UC tissue pieces of similar size and weight (graph insert) from conditioned UC tissue pieces after cryopreservation and reculture were labeled by lentiviral eGFP gene transduction. Thereafter, the UC tissues were incubated in MSC medium for up to 7 days and the GFP fluorescence intensity in the tissues was monitored every 24 hours. Data represent the mean ± SD (n = 6). Statistical analysis was performed by Student's t test between the fluorescence intensities of the unlabeled UC tissues (autofluorescence of the tissues = control) and after the second day of eGFP gene transduction (p <0.1). Moreover, statistical differences between the fluorescence intensities of day 1 and day 7 revealed a significance of p <0.005. bp base pairs, GFP green fluorescent protein