Transplantation of human umbilical cord mesenchymal stem cell relieves the symptoms of lupus nephritis by inhibiting osteopontin expression

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease which may develop into lupus nephritis (LN) and subsequently lead to injury of renal microstructure. It has been indicated that mesenchymal stem cell (MSC) showed therapeutic effect in LN. Here, we present evidence of mechanisms of human umbilical cord derived MSC (Huc-MSC) in ameliorating symptoms of LN. Our results demonstrated that proteinuria concentration is significantly decreased after Huc-MSC transplantation. Moreover, we observed a significant reduction of osteopontin (OPN) expression in renal tissues from Huc-MSC-transplant mice. The expression of matrix metalloproteinases 2 (MMP-2) and MMP-9 were inhibited in renal tissues of Huc-MSC transplantation by the similar fashion. Our results also indicated that the expression of MMP-2 and MMP-9 correlated with basal OPN expression. Finally, our results showed that Huc-MSC treatment can inhibit the expressions of transcription factors AP-1 and SP-1 as well as NF-kappa B, which were also is associated with the low levels of OPN. Taken together, we report an alternative mechanism of Huc-MSC treatment in LN possibly through inhibiting OPN expression.