Effect of mesenchymal stromal (stem) cell (MSC) transplantation in asthmatic animal models: A systematic review and meta-analysis.

ABSTRACT

BACKGROUND: Over the years, mesenchymal stromal (stem) cells (MSCs) have been pre-clinically applied in the treatment of variety kinds of diseases including asthma and chronic lung diseases. Aim of the current study was to systematically review and to conduct meta-analysis on the published studies of MSC treatment in asthma animal models. METHODS: Publications on the MSC and asthma treatment was thoroughly searched in the electronic databases. Statistical analysis was then performed using the Comprehensive Meta-Analysis software (Version 3). Effect of MSC therapy on asthma model was assessed by Hedges's g with 95% confidence intervals (95% CIs). Random effect model was used due to the heterogeneity between the studies. RESULTS: Meta-analysis of the 32 included studies showed that MSC transplantation was significantly in favor of attenuating lung injury and remodeling (Hedges's g = -9.104 ±â€¯0.951 with 95% CI -10.969 ∼ -7.240, P < 0.001) and airway inflammation (Hedges's g = -4.146 ±â€¯0.688 with 95% CI -5.495 ∼ -2.797, P < 0.001). The mechanism of MSC therapy in asthma seems to be regulating the balance of Th1 cytokine and Th2 cytokines (IFN-γ Hedges's g = 4.779 ±â€¯1.408 with 95% CI 1.099-2.725, P < 0.001; IL-4 Hedges's g = -10.781 ±â€¯1.062 with 95% CI -12.863 ∼ -8.699, P < 0.001; IL-5 Hedges's g = -10.537 ±â€¯1.269 with 95% CI -13.025 ∼ -8.050, P < 0.001; IL-13 Hedges's g = -6.773 ±â€¯0.788 with 95% CI -8.318 ∼ -5.229, P < 0.001). CONCLUSION: Findings of the current systemic review suggested a potential role for MSCs in asthma treatment although it is still challenging in clinical practice. The mechanisms of MSCs in pre-clinical asthma treatment may be associated with attenuating airway inflammation through regulating Th1 and Th2 cytokines.