Therapeutic Benefit for Late, but Not Early, Passage Mesenchymal Stem Cells on Pain Behaviour in an Animal Model of Osteoarthritis

Figure 3

(a) Timecourse of the effects of intra-articular injection of the steroid Kenalog (200 μg/20 μL) versus 1.5 × 10⁶ of early passage mMSC on weight-bearing asymmetry. Rats received the active treatments or 50 μL SFM (vehicle) on day 14 postsurgery. Kenalog had a rapid inhibitory effect on MNX-induced weight-bearing asymmetry at 17 and 21 days post model induction, compared to the MNX-SFM group. mMSC treatment significantly increased weight-bearing asymmetry at early timepoints (days 17 and 21) post model induction. At later timepoints, weight-bearing asymmetry was comparable between the MNX-MSC group and the MNX-SFM group. Data was analysed using a 2-way ANOVA with Tukey’s post hoc test. MNX-SFM versus sham-SFM, ## MNX-MSC versus MNX-SFM; @, @@@@ MNX steroid versus MNX-MSC. (b) Area under the curve (AUC) analysis of the effects of intra-articular injection of steroid Kenalog versus 1.5 × 10⁶ of early passage mMSC on MNX-induced weight-bearing asymmetry for the last three timepoints (days 31, 35, and 38). mMSC treatment did not alter weight-bearing asymmetry in MNX rats. Although there was a trend towards an inhibition of weight-bearing asymmetry by Kenalog, this was only significantly compared to the MNX-mMSC group. Data are expressed as a % of the mean MNX-SFM AUC for timepoints 31, 35, and 38 days postsurgery. Statistical analysis used a Kruskal-Wallis test with Dunn’s post hoc, . Data are mean ± SEM, n = 9-10 per group.

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