Retinoic acid-mediated anti-inflammatory responses in equine immune cells stimulated by LPS and allogeneic mesenchymal stem cells.

The research article explores the potential of Retinoic acid (RA), a derivative of vitamin A, in reducing inflammatory responses in equine immune cells stimulated by Lipopolysaccharides (LPS) and allogeneic mesenchymal stem cells (MSCs). The study also observes RA’s effect on the viability and morphology of these stimulated cells.

Research Context

• Retinoic acid (RA), an active metabolite of vitamin A, has proven to possess therapeutic immunomodulatory properties, suggesting it could be valuable in medical treatments.
• MSCs-based therapies have been demonstrated to be effective for tissue healing and regeneration in various equine orthopedic conditions. However, these therapies can induce inflammatory responses in vivo, which could potentially complicate treatments.
• As such, this study explores the effect of RA on the inflammatory responses of LPS- and MSCs-stimulated equine immune cells. It also investigates RA’s impact on the viability and morphology of these stimulated cells.

Experimental Findings

• The researchers observed that PBMCs, stimulated by allogeneic MSCs, displayed significant decreases in anti-inflammatory cytokines such as IL-10, IL-1ra, and TGF-β1. Simultaneously, they recorded increases in pro-inflammatory mediators like IL-1β, IL-6, TNF-α, SAA, and an increase in CD14 and MHC II percent positive cells compared to LPS- and non-stimulated PBMCs.
• When these LPS- and allogeneic MSCs-stimulated PBMCs were treated with RA, the induced inflammatory responses were counteracted. Therefore, RA proved its potential as an immunomodulatory agent.
• Besides, RA significantly improved the viability and morphology of stimulated MSCs. This particular observation suggests that RA could ensure the effectiveness of MSCs-based therapies by protecting the stem cells themselves.

Implications and Further Steps

• The results of the study highlight the potential complications that could arise from equine allogeneic MSCs-based therapies, particularly concerning the inflammatory response they may induce.
• The study also underscores the immunomodulatory effect of RA on equine stimulated immune cells, suggesting a possible strategy to manage the inflammatory responses associated with MSCs-based therapies.
• Lastly, the researchers suggest further investigation into the use of RA to ameliorate inflammation associated with allogeneic MSCs therapy, with a view to enhance and optimize this therapeutic approach.