Rapamycin reverses the senescent phenotype and improves immunoregulation of mesenchymal stem cells from MRL/lpr mice and systemic lupus erythematosus patients through inhibition of the mTOR signaling pathway

Abstract

We have shown that bone marrow (BM)-derived mesenchymal stem cells (BM-MSCs) from SLE patients exhibit senescent behavior and are involved in the pathogenesis of SLE. The aim of this study was to investigate the effects of rapamycin (RAPA) on the senescences and immunoregulatory ability of MSCs of MRL/lpr mice and SLE patients and the underlying mechanisms. Cell morphology, senescence associated β-galactosidase (SA-β-gal) staining, F-actin staining were used to detect the senescence of cells. BM-MSCs and purified CD4+ T cells were co-cultured indirectly. Flow cytometry was used to inspect the proportion of regulatory T (Treg) /T helper type 17 (Th17). We used small interfering RNA (siRNA) to interfere the expression of mTOR, and detect the effects by RT-PCR, WB and immunofluorescence. Finally, 1×106 of SLE BM-MSCs treated with RAPA were transplanted to cure the 8 MRL/lpr mice aged 16 weeks for 12 weeks. We demonstrated that RAPA alleviated the clinical symptoms of lupus nephritis and prolonged survival in MRL/lpr mice. RAPA reversed the senescent phenotype and improved immunoregulation of MSCs from MRL/lpr mice and SLE patients through inhibition of the mTOR signaling pathway. Marked therapeutic effects were observed in MRL/lpr mice following transplantation of BM-MSCs from SLE patients pretreated with RAPA.

WITHDRAWN: Long-term data on sirolimus treatment in patients with lupus nephritis

“…The immunological effects of sirolimus on disease mechanisms in LN require further investigation. Possible mechanisms leading to a reduction of disease activity include reduction of intra-renal lymphoproliferation and MCP-1 expression, suppression of anti-dsDNA production and immune deposition, reversal of senescent phenotype of bone marrow-derived mesenchymal cells, promotion of Treg expansion and blockade of Th17 expansion [16][17][18][27][28][29][30]. Furthermore, the results from animal experiments and human kidney biopsies demonstrating activation of the mTOR pathway during active nephritis, and the therapeutic effect of mTOR inhibitor in murine lupus, provide a strong rationale for testing the effect of mTOR inhibitors in the treatment of human LN [16,17].…”

Activation of the Mechanistic Target of Rapamycin in SLE: Explosion of Evidence in the Last Five Years

“…SLE patient MSCs go through premature senescence in an mTOR-dependent manner [46]. In the presence of rapamycin, MSCs co-cultured with CD4+ T cells resulted in increased Tregs and depletion of Th17 cells in vitro [46].…”

“…SLE patient MSCs go through premature senescence in an mTOR-dependent manner [46]. In the presence of rapamycin, MSCs co-cultured with CD4+ T cells resulted in increased Tregs and depletion of Th17 cells in vitro [46]. Furthermore, rapamycin promoted the secretion of anti-inflammatory cytokines in these co-cultures and blocked their senescent phenotype [46].…”

“…In the presence of rapamycin, MSCs co-cultured with CD4+ T cells resulted in increased Tregs and depletion of Th17 cells in vitro [46]. Furthermore, rapamycin promoted the secretion of anti-inflammatory cytokines in these co-cultures and blocked their senescent phenotype [46]. In SLE patients, rapamycin and siRNA knockdown of mTOR resulted in the rescue of SLE patient MSCs [46].…”

“…Furthermore, rapamycin promoted the secretion of anti-inflammatory cytokines in these co-cultures and blocked their senescent phenotype [46]. In SLE patients, rapamycin and siRNA knockdown of mTOR resulted in the rescue of SLE patient MSCs [46]. Interestingly, SLE patient MSCs pre-treated with rapamycin and then transplanted via tail-vein injection into MRL/lpr mice resulted in some protection from lupus nephritis [46].…”