Fig. 6.

Neuroprotective and neurogenesis inducing features of oMSC and sMSC in transgenic AD mice

(a) Photomicrographs of DCX expression and quantification of DCX+ neurons in the hippocampi of 13-month-old 3xTg-AD mice after INA of o/sMSC (2 x application of 1 × 10⁶ cells, n=3 per group). The number of DCX+ cells was quantified from 10 brain sections of each animal and normalized to mm². Each column represents 9-10 data points obtained from 10 sections. ANOVA with Bonferroni's multiple comparisons test was used to compare vehicle-, oMSC and sMSC-treated groups (*p <0.05). Error bars: SEM. Scale bar: 500 µm. DCX, doublecortin.

(b) Quantification of NeuN/TUNEL+ neurons in the DG and CA1-3 in 13-month-old 3xTg-AD mice (n=4 per group) after INA of oMSC and sMSC. Cells were quantified in 10 sections from each brain and normalized to mm². Each column represents 6-11 data points obtained from 10 sections. ANOVA with Bonferroni's multiple comparisons test was used to compare vehicle-, oMSC and sMSC-treated groups (*p <0.05; **p <0.01). Error bars: SEM. CA, cornu ammonis; DG, dentate gyrus.

(c) Western blot with densitometric analysis of synaptophysin in brain homogenates of 13-month-old 3xTg-AD mice (n=3 per group) after INA of oMSC and sMSC. ANOVA with Bonferroni's multiple comparisons test was used to compare vehicle-, oMSC and sMSC-treated groups (*p <0.05). Error bars: SEM.

(d) In vivo activity of layer 2/3 neurons located in the vicinity of amyloid plaques in the cortex of 7-8-month-old APP23xPS45 mice after INA of vehicle or o/sMSC (2x application of 1 × 10⁶ cells, n=5 mice per group). Left panel: Neurons classified based on the frequency of their spontaneous Ca²⁺ transients as silent (0-0.25 transients/min), normal (0.26-4 transients/min), and hyperactive (>4 transients/min) [31]. Pie charts show fractions of hyperactive (red), normal (green) and silent (blue) cells. The relative fractions of different cell types are significantly different (Chi-square test. Vehicle vs. oMSC: p=0.0006, ChiSquare=14.95, df=2; vehicle vs. sMSC: p<0.0001, ChiSquare=31.83, df=2; oMSC vs. sMSC: p=0.034, ChiSquare=6.79, df=2). Right panel: Cumulative histogram showing frequency distribution of Ca²⁺ transients recorded from neurons close to amyloid plaques after INA of vehicle (225 cells), oMSC (285 cells), and sMSC (310 cells). oMSC and sMSC treatment shifted the frequency distribution significantly towards lower values, and therefore reduced pathological hyperactivity in cortical neurons (Kolmogorov-Smirnov-test. Vehicle vs. oMSC: p<0.0001, D=0.204; Vehicle vs. sMSC: p<0.0001, D=0.336; oMSC vs. sMSC: p=0.0002, D=0.173).

(e) Analysis of indicated protein levels by V-plex® analysis (n=5-8 per group; individual samples were collectively analysed by V-plex®) and mRNA levels by qPCR (n=4-5 per group; individual samples collectively analysed for the respective targets) after INA of oMSC and sMSC. IL-12 and IFNγ were barely detectable (data not shown). ANOVA with Bonferroni's multiple comparisons test was used to compare vehicle-, oMSC and sMSC-treated groups (*p <0.05; ***p <0.001). Error bars: SEM. IL, interleukin; NEP, neprilysin. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)