Effects of 25-OH vitamin D supplementation on mesenchymal stromal cells in an animal model of Systemic Lupus Erythematosus (SLE)

In systemic lupus erythematous (SLE), mesenchymal stromal cells (MSCs) are defective and may present early signs of senescence. In a previous study we demonstrated as the treatment with hydroxychloroquine may influence the clonogenic potential of MSCs in a SLE animal model. Vitamin D may influence several aspects of the innate and adaptative immune response and low serum levels of vitamin D are common in SLE patients and were correlated to higher disease activity and severity. The aim of this study is to identify the effect of 25-OH vitamin D, on MSCs characteristics in New Zealand Black/White F1 mice (NZ), that develop a disease very similar to human SLE. We are treating 20 NZ with a diet enriched with 25-OH-vitamin-D 10.000 UI/Kg, mice starting from 8 weeks of age. We divided the mice in 4 experimental groups (5 mice each), the first group will be sacrificed before the start of the treatment (8 week of age) and the other groups will be sacrificed at 16, 26 and 36 weeks of age. Fifteen mice were enrolled as controls and they will be sacrificed at 16, 26 and 36 weeks of age. We are evaluating disease activity parameters including total urinary protein parameters, anti-dsDNA autoantibody, 25OH vitamin D ant parathormone levels. MSC phenotype is confirmed by cytofluorimetry (expression of Sca-1 and CD-106, negativity for CD45) and we also evaluate differentiation capability in adipogenic and osteoblast lineage. Clonogenic potential is evaluated in at the seeding (P0) and in the following 2 passages (P1 and P2 respectively one and two weeks after the seeding) with the Colony Forming Unit (CFU) assay.