Prednisolone attenuates the immunomodulatory capacity and reshapes the functional phenotype of canine adipose-derived mesenchymal stromal cells

Introduction Mesenchymal stromal cells (MSCs) are a promising therapeutic option for refractory canine chronic inflammatory enteropathy (CIE), primarily because of their immunomodulatory properties. However, MSC function may be influenced by concomitant medications, including prednisolone. Therefore, we investigated the effects of prednisolone on canine adipose-derived MSCs (cADSCs), with particular focus on immunomodulatory capacity and migratory behavior. Methods Effects on the biological and functional properties of cADSCs were evaluated following treatment with prednisolone ranging from 0.01 to 100 μM. Morphology, senescence, apoptosis, proliferation, cell-cycle distribution, mitochondrial activity, migration, and invasion were assessed. Immunomodulatory function was assessed by co-culture assays using DH82 macrophages and canine peripheral blood mononuclear cells (PBMCs), including analyses of macrophage polarization, regulatory T-cell induction, T-cell subset composition, activation, and proliferation. RNA sequencing was performed to characterize transcriptomic changes in cADSCs treated with or without prednisolone and cultured with or without activated PBMCs. Results Prednisolone did not induce apparent morphological changes, senescence, or apoptosis in cADSCs, but altered proliferation, mitochondrial activity, and migratory behavior and attenuated key immunomodulatory functions. RNA sequencing revealed that prednisolone suppressed inflammatory signaling in cADSCs under basal conditions, whereas these cells retained robust inflammatory transcriptional responsiveness to signals derived from activated PBMC. Conclusions Prednisolone reshapes cADSC function in a context-dependent manner, reducing immunomodulatory capacity without substantially impairing viability. These findings suggest that glucocorticoid exposure and inflammatory activation interact to modulate cADSC function and should be considered when optimizing MSC-based therapy for canine CIE.