Equine Colostrum-Derived Mesenchymal Stromal Cells: A Potential Resource for Veterinary Regenerative Medicine

Beyond its immunological role, colostrum has emerged as a promising, non-invasive source of bioactive factors, including Mesenchymal Stromal Cells (MSCs). This study represents the first attempt to isolate and characterize MSCs from equine colostrum (C-MSCs) and assess their potential use in veterinary regenerative medicine. Colostrum (n=6) was collected immediately after delivery, centrifuged, and recovered cells cultured under standard conditions. C-MSCs displayed plastic adherence and heterogeneous morphology, including spindle-shaped and epithelial-like cells. PDT values varied among samples, and 4/6 showed rapid proliferation (< 2 days). CFU assays confirmed clonogenic potential, though significant inter-sample variability was observed (p< 0.05). Spheroid formation assays revealed differences in cell-cell adhesion: 4/6 samples formed stable spheroids within four days. Migration assay showed significant variability (p< 0.05): 1/6 achieved complete wound closure within 72 hours, whereas 5/6 reached ~30% at 96 hours. Differentiation assays confirmed trilineage potential, with all samples staining positive for adipogenic, chondrogenic, and osteogenic differentiation. RT-PCR confirmed MSC marker expression, while hematopoietic markers were absent. MHC-I expression was weak in 5/6 samples, whereas MHC-II was consistently negative. These findings support equine colostrum as a viable MSC source, though variability requires further validation with larger samples. Additional research is needed to investigate C-MSCs' immunomodulatory properties and therapeutic potential.